INTRODUCTION. In native knees the anterior cruciate ligament (ACL) plays a major role in joint stability and kinematics. Sacrificing the ACL in contemporary total knee arthroplasty (TKA) is known to cause abnormal knee motion, and reduced function. Hence, there is growing interest in the development of ACL retaining TKA implants. Accommodation of ACL insertion around the tibial eminence is a challenge with these designs. Therefore, a reproducible and practical test setup is necessary to characterize the strength of the ACL/bone construct in ACL retaining implants. Seminal work showed importance of loading the ACL along its anatomical orientation. However, prior setups designed for this purpose are complex and difficult to incorporate into a standardized test for wide adoption. The goal of this study was to develop a standardized and anatomically relevant test setup for repeatable strength assessment of ACL construct using basic force-displacement testing equipment. METHODS. Cadaver knees were positioned with the ACL oriented along the loading axis and being the only connection between femur and tibia. 15° knee flexion was selected based on highest ACL tensions reported in literature. Therefore, the fixtures were adjusted accordingly to retain 15° knee flexion when the ACL was tensioned. The test protocol included 10 cycles of preconditioning between 6N and 60N at 1mm/s, followed by continuous distraction at 1mm/s until failure (Fig. 1). Eleven cadaveric knees (4 male, 7 female; 70.9 yrs +/−13.9 yrs) were tested using this setup to characterize a baseline ACL pullout strength (peak load to failure) in native knees. RESULTS. The average ACL pullout strength was 935.6N +/−327.5N with the extremes ranging from a minimum of 346N to a maximum of 1425N. There were five failure modes observed: [1] ACL avulsion from the femur with bony attachment (one knee), [2] ACL pull-off from the femur w/o bony attachment (two knees), [3] ACL tear (three knees), [4] ACL pull-off from the tibia w/o bony attachment (one knee), [5] ACL avulsion from the tibia with bony attachment (three knees). One knee showed a combined failure mode of 2 & 4, meaning part of the ACL was pulled off the femur and part pulled off the tibia. CONCLUSION. There was a large variation in failure load between specimens. The knee with the minimum failure load had severe arthritis, osteophytes and signs of ACL deficiency. The average failure load (935.6N +/−327.5N) is in line with those published in literature for a comparable age group. This indicates that failure loads and modes obtained with more complex setups could be reproduced by using standard uniaxial load frames and simple fixtures. The failure modes in our experiment were evenly spread between mid-substance, and insertions (either femur or tibia). This test could be used as a standardized method to investigate the strength of the ACL complex following procedures such as ACL reconstruction, partial- and total knee arthroplasty. In particular, this setup provides a reliable mechanism for evaluation of the ACL-bone construct in bi-cruciate retaining (BCR) TKA, which is likely required for regulatory pathways

Knee joint infection after an ACL reconstruction procedure is infrequently but might be a devastating clinical problem, if not diagnosed promptly and treated wisely. The results of functional outcomes in these patients are not well known because there aren't large patient series in the literature. The objective of this study was to evaluate the prevalence and determine the adequate management of septic arthritis following ACL reconstruction and to assess the patient functional outcomes. The authors conducted a retrospective multicentric analysis of septic arthritis cases occurring after arthroscopically assisted ACL reconstructions (hamstrings and BTB), in patients submitted to surgery between 2010 to 2014. The study reviewed patients submitted do ACL reconstruction, that presented objective clinical suspicion of joint infection, in post-operative acute and sub-acute phases, associated with high inflammatory seric parameters (CRP >=10,0, ESR>=30,0) and synovial effusion laboratory parameters highly suggestive (PMN >=80, leucocytes >=3000). All this patients were treated with antibiotic empiric suppressive therapy and then directed antibiotherapy according to antibiotic sensitivity profile, then the patients were submitted to arthroscopic lavage procedure, without arthropump, but with debris and fibrotic tissue removal preserving always the ACL plasty. The functional outcomes analyzed were the Lysholm and the IKDC score. Eleven (2.2 %) out of 490 patients analyzed in the sudy were diagnosed with a post-operative septic arthritis. The microbiologic exams showed coagulase-negative Staphylococcus was present in 5 patients (S. lugdunensis in 4 cases and S. capitis in 1 case), Staphylococcus Aureus in 2 patients (1 MSSA and 1 MRSA). In four patients, the micro-organism was not identified. The studied patients had a mean follow-up of 28 ± 16 months, the Lysholm score was 74.8 ± 12.2, the IKDC score was 66.4 ± 20.5. Functional outcomes in the control group were better than those obtained in the infected group. (Lysholm score 88.2 ± 9.4 (NS); IKDC score 86.6 ± 6.8 (NS). All patients retained their reconstructed ACL. None of the patients relapsed or need other intervention because of ACL failure and chronic instability. The prevalence of septic arthritis after an ACL reconstruction in this series was 2.2 %, slightly higher than other international series (0.14 to 1.7 %). Arthroscopic lavages along with antibiotic treatment showed to be a secure procedure and allowed the preservation of the ACL plasties, without infection relapse. But the functional outcomes after active intra-articular infection were largely inferior to those obtained in patients without infection, probably to uncontrolled and intense inflammatory local response

Introduction and purpose: To assess the diagnostic usefulness of MRI to diagnose ACL lesions using quantitative instead of qualitative parameters. Materials and methods: A retrospective study was made of the MRIs of a group of 50 patients with an athroscopically confirmed ACL tear and a control group of 50 patients with meniscal lesions and with an arthroscopic confirmation that they had a normal ACL. Multiple MRI findings were studied in order to evaluate their sensitivity and Specificity to detect an ACL lesion. Special emphasis was placed on 3 quantitative parameters, including a simplified method to measure the angle between the ACL and the tibial plateau. Results: Using 45° as a cutoff value, the ACL/tibial plateau angle yielded a sensitivity and Specificity of 100%. With a 0° cutoff value, the angle together with Blumensaat’s line showed a sensitivity of 90% and a Specificity of 98%. With a cutoff value of 115°, the PCL angle showed a sensitivity of 70% and a Specificity of 82%. Conclusions: The quantitative parameters studied are valuable to predict ACL lesions and can increase both the sensitivity and Specificity of MRI images. The ACL/ tibial plateau angle can be measured easily using a single MRI image and can be regarded as the best clue to diagnose ACL lesions

Anterior cruciate ligament reconstruction has become a standard procedure with a documented good and excellent outcome of 70–90%. It has been demonstrated by previous research that all patients following surgery demonstrate a strength deficit of almost 20%. However it is not known whether these strength deficits have an influence on postoperative functionality. 52 consecutive patients (38 males and 14 females) were selected (mean age 27.9 years). All subjects were tested prior and 12 month following anterior cruciate ligament reconstruction. Muscle strength was assessed using a Biodex dynamometer. Isometric strength was examined at 30 and 60 degrees of flexion. Isokinetic testing was performed at 180 degrees/sec and peak torque and symmetry indices were analysed. No correlations were found between the Cinncinnati Score and isokinetic peak torque for extension. A moderate significant (p=0.001–0.007) correlation (r=0.200.45) was found for peak flexion torque in ACL reconstructed patients. In ACL deficient patients symmetry indices (r=0.36–0.43, p=0.001–0.004) were moderately related to functionality for both flexion and extension. Quadriceps muscle strength does not seem to be an important predictor of knee function after ACL reconstruction. Flexors seem to be important to protect the graft from overload. In ACLD knees functionality is related to high symmetry indices suggesting similar strength is necessary to perceive knee function as near normal. This is possibly a normal neuromuscular adaptation caused by contralateral quadriceps avoidance

The level of hamstring antagonist activation is thought to be related to knee functionality following anterior cruciate ligament (ACL) injury/surgery as pronounced co-activation can control anterior tibial translation (ATT). The purpose of this study was to examine relationships between knee functionality and hamstring antagonist activation during isokinetic knee extension in ACL deficient (ACLD) and ACL reconstructed (ACLR) patients. Knee functionality was rated using the Cincinnati Knee Rating System for the involved limb of 10 chronic, functional ACLD patients and 27 ACLR patients (14 using a patella tendon (PT) graft and 13 using a semitendinosus/gracilis tendon (STGT) graft). Each subject also performed maximal effort isokinetic knee extension and flexion at 180°. s. -1. for the involved limb with electromyographic (EMG) electrodes attached to the semitendinosus (ST) and biceps femoris (BF) muscles. Antagonist activity of the ST and BF muscles was calculated in 10° intervals between 80-10° knee flexion. For the ACLD group, Pearson product moment correlations revealed significant (p<0.05) moderate, positive relationships between knee functionality and ST and BF antagonist activity across the majority of the knee flexion intervals. For both ACLR groups, several significant (p<0.05) moderate, negative associations were found between ST and BF antagonist activity and knee functionality. Amplified hamstring antagonist activity in ACLD patients at flexion angles representative of those at footstrike and deceleration improves knee functionality as increased crossbridge formation increases hamstring stiffness and decreases ATT. Lower-level hamstring activation is sufficient to unload the ACL graft and improve knee functionality in ACLR patients

The purpose of this study was initially to examine the effect of tibial slope on anterior tibial translation in the ACL deficient knee measured objectively using the KT 1000 arthrometer. Patients were then evaluated one year post ACL reconstruction to determine the effect of tibial slope on the outcome of ACL reconstruction. One-hundred patients (male = 70, female 30) aged between 14 and 49 years (Mean = 28.70, SD 8.80) with a diagnosis of isolated anterior cruciate ligament rupture were prospectively recruited. All participants had intact ACLs of the contralateral limb. The following information was recorded for all patients preoperatively and one year post surgery; time from injury to surgery, IKDC objective and subjective assessment and KT 1000 arthrometer readings. Tibial slope was assessed from long tibial lateral x-rays as described by Dejour and Bonnin. Finally, assessment of the menisci occurred intra-operatively. Tibial slope was correlated with KT 1000, meniscal integrity and IKDC assessments. Patients underwent an arthroscopic hamstring ACL reconstruction using Endobutton and Intrafix fixation. All procedures were performed by one surgeon. Pre Reconstruction – Bivariate correlations showed a significant correlation between tibial slope and KT 1000 (r= .29, p < .001). This relation was strengthened when the integrity of the menisci were controlled for (r = .32, p < . 001). When time to surgery was controlled for, correlations between tibial slope and KT 1000 were unaffected. There was also a negative correlation between medial meniscal integrity and time to surgery (r = −.41, p < . 001). No relationships between time to surgery and KT 1000 were evident. Post Reconstruction – Eighty patients were evaluated at a one year post surgery. One patient had a rerupture. The mean KT 1000 difference was 1mm. KT 1000 was > 2mm in 9% and > 5mm in the re rupture only. The mean subjective IKDC score was 89. Using objective IKDC 89% were classified as normal, 10% as nearly normal and 1% as severely abnormal (the rerupture). Bivariate correlations showed no significant correlation between tibial slope and post operative KT 1000 (r= .178, p = .0.115). This study demonstrates a significant relationship between increasing tibial slope and anterior tibial translation of the ACL deficient knee. The relationship did not exist in the post ACL reconstructed knee. However this needs to be investigated further with greater numbers and in the ACL revision group

One of the key factors responsible for altered kinematics and joint stability following contemporary total knee arthroplasty (TKA) is resection of the anterior cruciate ligament (ACL). Therefore, retaining the ACL is often considered to be the “holy grail” of TKA. However, ACL retention can present several technical challenges, and in some cases may not be viable due to an absent or non-functional ACL. Therefore, the goal of this research was to investigate whether substitution of ACL function through an anterior post mechanism could improve kinematic deficits of contemporary posterior cruciate ligament (PCL) retaining (CR) implants. This was done using KneeSIM, a previously established dynamic simulation tool based on an Oxford-rig setup. Deep knee bend, chair-sit, stair-ascent and walking were simulated for a contemporary ACL sacrificing (CR) implant, two ACL retaining implants, and an ACL substituting and PCL retaining implant. The motion of the femoral condyles relative to the tibia was recorded for kinematic comparisons. Our results revealed that, like ACL retaining implants, the ACL substituting implant could also provide kinematic improvements over contemporary ACL sacrificing implants by reducing early posterior femoral shift and preventing paradoxical anterior sliding. Such ACL substituting implants may be a valuable addition to the armament of joint surgeons, allowing them to provide improved knee function even when ACL retention is not feasible. Further research is required to investigate this mechanism in vitro and in vivo to verify the results of the simulations, and to determine whether kinematic improvements translate into improved clinical outcomes

Summary. This study describes the use of a quasi-static, 6DOF knee loading simulator using cadaveric specimens. Muscle force profiles yield repeatable results. Intra-articular pressure and contact area are dependent on loading condition and ACL integrity. Introduction. Abnormal contact mechanics of the tibiofemoral joint is believed to influence the development and progression of joint derangements. As such, understanding the factors that regulate joint stability may provide insight into the underlying injury mechanisms. Muscle action is believed to be the most important factor since it is the only dynamic regulator of joint stability. Furthermore, abnormal muscle control has been experimentally linked to the development of OA [Herzog, 2007] and in vivo ACL strain [Fleming, 2001]. However, the individual contributions to knee joint contact mechanics remain unclear. Thus, the purpose of this study was to examine the effects of individual muscle contributions on the tibiofemoral contact mechanics using an in-vitro experimental protocol. Methodology. Contact mechanics of 6 fresh frozen cadaver knee specimens were evaluated using the UofO Oxford knee loading device. Various combinations of quadriceps-hamstring co-contraction ratios were applied to the knee while it was “suspended” between the hip and foot components of the device. Loads of six muscle groups were computed using a hill-type musculoskeletal model [Buchanan, 2004]. Simulated ground reaction forces were also applied to the knee to represent force profiles of weight acceptance during gait as it has been shown to produce peak knee joint force in the gait cycle [Shelburne et al., 2006]. For respective medial and lateral joint compartments, the mean contact area (MC-CA and LC-CA), mean contact pressure (MC-CP and LC-CP), peak pressure (MC-PP and LC-PP), and centre of force displacement (MC-COFD and LC-COFD) were determined using a 4011 piezoelectric sensor form Tekscan (Tekscan Inc. Boston, MA). Additionally, the ACL was resected and measurements were repeated. Pearson correlations (r) examined the reliability of measurements as well as the effect an ACL transection on articular loads. Results. Positive correlations were computed for the following: COFD with intact ACL (r=0.99), COFD with resected ACL (r=0.82), MC-COFD pre vs. post ACL- resection (0.91). Furthermore, preliminary results indicated a positive correlation between MC-CA and ACL integrity (r=0.97). Discussion. The repeatability of the measured dependant variables validates the use of the knee-loading device. Interestingly, contact mechanics are more variable post ACL resection for a given muscle loading condition, indicating a decrease in knee joint stability. Also, the COFD is dependent on the different ratios of muscle loads applied to the knee, which demonstrates the importance of muscle action to the modulation of contact forces

Combined anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) disruptions are uncommon orthopaedic injuries. They are usually caused by high- or low-velocity knee dislocations. Because knee dislocations might spontaneously reduce before initial evaluation, the true incidence is unknown. Dislocation involves injury to multiple ligaments of the knee. Both of the cruciate ligaments are usually disrupted, and they are often combined with a third ligamentous disruption (medial collateral ligament or lateral collateral ligament and/or posterior lateral complex). Associated neurovascular, meniscal, and osteochondral injuries are often present and complicate treatment. Classification Knee dislocations are classified by relating the position of the displaced tibia on the femur; anterior, posterior, medial, lateral, or rotational. Both cruciate ligaments might be disrupted in all these injuries. A rotatory knee dislocation occurs around one of the collateral ligaments (LCL) leading to a combined ACL and PCL injury and a tear of the remaining collateral ligament. Knee dislocations that spontaneously reduce are classified according to the direction of instability. Knee dislocations are classified as acute (< 3 weeks) or chronic (> 3 weeks). Initial management The vascular status of the limb must be determined quickly. The knee should be reduced immediately through gentle traction-countertraction with the patient under anesthesia. After reduction, repeat vascular examination. If the limb remains ischemic, emergent surgical exploration and revascularisation is required. If the initial vascular examination is normal, postreduction a formal angiogram should be done especially if the patient has a high velocity injury, is polytraumatized or have altered mental status. Compartment syndrome, open injury, and irreducible dislocation are other indications for emergent surgery. Definitive management Many authors have noted superior results of surgical treatment of bicruciate injuries when compared to nonsurgical treatment. In most cases early ligament surgery (at the second or third week) seems to produce better results compared to late reconstructions. Still the management of knee dislocations remains controversial. Controversies persist regarding surgical timing, technique, graft selection, and rehabilitation. The goal of operative treatment is to retain knee stability, motion, and function. The most common injury patterns include both cruciate ligaments and either medial collateral ligament (MCL) or lateral collateral ligament (LCL) and/or posterolateral structures. Less commonly both collateral ligaments are disrupted. Our policy has been early (from 7 to 21 days) simultaneous reconstruction of both cruciate ligaments and repairing of grade III LCL and posterolateral structures. Most acute grade III MCL tears are successfully treated with brace treatment when ACL and PCL are reconstructed early. Most cruciate ligament injuries are midsubstance tears that need to be reconstructed with autografts or allografts. Repairs can be done in cases of bony avulsion of cruciate ligaments or grade III collateral ligament or capsular injuries. Bone-patellar tendon-bone (BPTB) autograft has mainly used in our clinics to reconstruct the ACL. In some cases BTPB allograft or hamstring tendon autografts has been used. For PCL reconstruction, BPTB allograft (11 mm in diameter) or Achilles tendon allograft has been used. Intrasubstance grade III tears of the LCL can be repaired (in early state) but may need to be augmented with tendon allograft. The LCL and/or the popliteofibular ligament are reconstructed either with an Achilles tendon allograft, hamstring tendon autograft/allograft, tibialis anterior tendon allograft, or the BPTB allograft. Both cruciate ligaments are reconstructed arthroscopically. The ACL tunnels are placed in the center of its anatomic insertion in tibia and in its isometric or anatomic insertion in femur. A transtibial tunnel technique for PCL reconstruction is used. The PCL tibial tunnel is drilled first under arthroscopic guidance using the PCL guide. The ACL tibial guide is drilled at least 2 cm proximal to the PCL tunnel to ensure that wide enough bone bridge remains between these tunnels. Fluoroscopy is used to ensure the right guidewire placement. Sequence of bicruciate ligament reconstruction with BPTB grafts. Drill PCL tibial tunnel first, then ACL tibial tunnel. Drill ACL femoral tunnel, then PCL femoral tunnel. Pass PCL graft through tibial tunnel and fix in femoral tunnel. Pass ACL graft through tibial tunnel and fix in femoral tunnel. Fix PCL graft on tibia at 90° of flexion with anteromedial step off. Fix ACL graft on tibia at extension. Rehabilitation Our protocol after bicruciate ligament reconstruction with MPTB grafts has been very active. Progressive range of motion is started early after the operation with an unlocked functional brace. If simultaneous suturation of a meniscus tear has been performed, motion is limited to 60° of flexion during the first 4 weeks. Progression from partial to full weight bearing is done over the first 6 weeks. Quadriceps exercises are progressed to open-chain knee extension exercises early as well as closed-chain hamstring exercises. Brace is discontinued after 12 weeks

ACL injured patients show variability in the ability to perform functional activities (Button et al., 2006). It is unknown whether this is due to differences in physical capability or whether fear of re-injury plays a role. Fear of re-injury is not commonly addressed in rehabilitation. This study aimed to investigate whether fear of re-injury impacts rehabilitation of ACL injured patients. An initial group of five ACL reconstructed participants (ACLR, age: 30±11 years, weight: 815±115 N, height: 1.74±0.07 m, all male), five ACL deficient participants (ACLD, age: 31±12 years, weight: 833±227 N, height: 1.80±0.11 m, four male and one female), and five healthy controls (age: 30±3 years, weight: 704±126 N, height: 1.70±0.09 m, three male and two female) were compared. Fear of re-injury was assessed using the Tampa Scale for Kinesiophobia (Kvist, 2004). Quadriceps strength was measured on a Biodex dynamometer. Functional activity was assessed by a single legged maximum distance hop (on the injured leg for ACL patients). Motion analysis was performed with a VICON system, and a Kistler force plate. Hop distance was calculated using the ankle position. The peak knee extension moment during landing, and the knee angle at this peak moment were calculated in VICON Nexus. The ACLD group scored worse on the Tampa scale for Kinesiophobia than the ACLR group (32±4 and 26±4). The ACLD patients did not hop as far as the ACLR and control groups (1.0±0.3, 1.3±0.1 and 1.4±0.3 m). The peak knee extension moments during landing were lowest in the ACLD group (263±159 Nm), slightly higher in the control group (354±122 Nm) and highest in the ACLR group (490±222 Nm), while knee flexion angles at these moments were similar (ACLD: 28±11, ACLR: 33±7 and control: 36±13 degrees). The ACLD group had weaker quadriceps than the control group, while the ACLR group was stronger (143±44 Nm, 152±42, and 167±50 Nm respectively). Fear of re-injury and decreased quadriceps strength potentially both impact on the functional performance of ACL injured patients. Rehabilitation of ACL injured patients could therefore be improved by addressing strength and fear of re-injury. Future research with more participants will further clarify this

Background. Anterior cruciate ligament (ACL) reconstruction with concomitant meniscal injury occurs frequently. Meniscal repair is associated with improved long-term outcomes compared to resection but is also associated with a higher reoperation rate. Knowledge of the risk factors for repair failure may be important in optimizing patient outcomes. Purpose. This study aimed to identify the patient and surgical risk factors for meniscal repair failure, defined as a subsequent meniscectomy, following concurrent primary ACL reconstruction. Methods. Data recorded by the New Zealand ACL Registry and the Accident Compensation Corporation, the New Zealand Government's sole funder of ACL reconstructions and any subsequent surgery, was reviewed. Meniscal repairs performed with concurrent primary ACL reconstruction was included. Root repairs were excluded. Univariate and multivariate survival analysis was performed to identify the patient and surgical risk factors for meniscal repair failure. Results. Between 2014 and 2020, a total of 3,024 meniscal repairs were performed during concurrent primary ACL reconstruction (medial repair = 1,814 and lateral repair = 1,210). The overall failure rate was 6.6% (n = 201) at a mean follow-up of 2.9 years, with a failure occurring in 7.8% of medial meniscal repairs (142 out of 1,814) and 4.9% of lateral meniscal repairs (59 out of 1,210). The risk of medial failure was higher in patients with a hamstring tendon autograft (adjusted HR = 2.20, p = 0.001), patients aged 21–30 years (adjusted HR = 1.60, p = 0.037) and in those with cartilage injury in the medial compartment (adjusted HR = 1.75, p = 0.002). The risk of lateral failure was higher in patients aged ≤ 20 years (adjusted HR = 2.79, p = 0.021) and when the procedure was performed by a surgeon with an annual ACL reconstruction case volume of less than 30 (adjusted HR = 1.84, p = 0.026). Conclusion. When performing meniscal repair during a primary ACL reconstruction, the use of a hamstring tendon autograft, younger age and the presence of concomitant cartilage injury in the medial compartment increases the risk of medial meniscal repair failure, whereas younger age and low surgeon volume increases the risk of lateral meniscal repair failure

Purpose. Patients with anterior cruciate ligament (ACL) deficiency and symptomatic medial compartment osteoarthritis (OA) present a challenge in management. These are often younger than typical primary OA patients and aspire to remain athletically active beyond simple ADLs. Combined ACL reconstruction and valgus tibial osteotomy (ACLHTO) is a well documented surgical option for patients deemed wither too young or too active for total knee arthroplasty. Unicompartmental knee arthroplasty (UKA) is an established surgical treatment for symptomatic medial osteoarthritis of the knee refractory to conservative management. A commonly cited contraindications is symptomatic ACL deficiency because of previous reports detailing premature failure through loosening of the tibial component. Improved results and endoscopic ACL reconstructive procedures have led to an enticing concept of combining ACL reconstruction with medial unicompartmental knee arthroplasty (ACLUKR) for those ACL-deficient medial osteoarthritic (OA) knees. We sought to compare the outcomes in 2 cohorts of patients who underwent either ACLHTO or ACLUKR for this clinical problem. Method. Patients presenting with symptomatic bone on bone medial compartment OA and concomitant ACL deficiency (clinical or asymptomatic) were evaluated for surgery after exhausting non operative management. Patients who were under 40 or had plans to return to high impact loading sports and/or who had more moderate OA were offered combined ACL – medial opening wedge tibia osteotomy as a surgical procedure of choice. Patients were considered for combined ACL Oxford replacement if they were primarily seeking pain relief and were not engaged or aspiring to return to high impact or pivoting sports. All cases but one were concurrent ACL with either HTO or UKR with autogenous hamstring grafts used in all but 2 cases. Results. Thirty of 34 consecutive cases were available for follow-up for a rate of 88%. The median ages for 14 cases of ACLUKR was 51 (range 43 60) whereas 16 patients with ACLHTO had median age 43.4 (range 32 −59). Median FU was 4.65 yrs with minimum 2 year follow up (range 2–8.3). Three of the cases were revision ACL cases all from previous Gore-Tex reconstructions. All but the first patient had concomitant ACL and Oxford unicompartmental knee replacement at 1 surgical sitting and are the subject of this report. The first patient had an autogenous patella bone tendon bone graft performed 6 months prior to the UKA. There were similar change scores for patients in both groups. For ACLUKR, WOMAC pain improvements from 48.1 10.2 SD preoperatively to 79.0 17 SD postop. For ACLHTO, WOMAC improvements from 55.1 13.2 SD preoperatively to 85.0 17 SD postop. To date there have been no cases of infection or bearing dislocation in the ACLUKR group. One patient in the ACLHTO group was revised to TKR for ongoing pain and postoperative flexion contracture. Patient activities ranged from ambulation to vigorous hiking, tennis, and downhill skiing in the UKR group whereas a few in the ACLHTO group were also running mid distances. Overall satisfaction was similar in both groups. Conclusion. ACL reconstruction can safely be combined with medial UKR. The procedure has been used in younger patients with a view toward bone preservation while anticipating need for future revision. Both cohorts showed similar improvements and can be considered. The choice should be geared toward patient athletic demand. While short term results are encouraging though longer term data are necessary to thoroughly evaluate the role of this procedure in patients with medial compartment osteoarthritis and ACL deficiency

The aim of this study was to assess the value of plain AP and lateral radiographs in determining ACL condition in medial unicompartmental osteoarthritis. Background: A functioning ACL has been shown to be important in the success of certain unicompartmental knee replacements. White (2001) has shown MRI to be too sensitive in this age group of patients. Keyes (1992) suggested that stress radiographs were necessary to accurately assess ACL integrity. Method: One hundred and twenty-six patients undergoing knee arthroplasty for medial osteoarthritis, had their ACL’s graded as Normal, Frayed or Absent intra-operatively. Standard pre-operative AP and lateral standing radiographs were graded by the Ahlback system. On the lateral view, the plateau was divided into 5 zones from anterior to posterior. The zone, in which the point of deepest wear occurred, was recorded. Results: There was a significant difference between the occurrence of deepest wear in the anterior three zones versus the posterior two zones for ACL normal and absent knees (. 2. = 46.85, P< 0.001). There was a significant difference between the occurrence of normal and absent ACL’s in Ahlback grades ≤3 versus ≥4 (. 2. = 53.8, P< 0.001). There was a moderately strong correlation between both zone of deepest wear on lateral radiograph and Ahlback grade with ACL condition (Spearman’s rho = 0.62 and 0.69 respectively). The Positive Predictive Values for the ACL being normal are 64% for Ahlback grades 3 or less and 67% for Zone of deepest wear in the anterior 3 zones. The Positive Predictive Values for the ACL being intact (but not necessarily normal) are 95% for Ahlback grade 3 or less; 91% for Zone of deepest wear in the anterior 3 zones; and 97% if these criteria are combined. Combining Ahlback grade ≤3 with wear in the anterior 3 zones also gave a Negative Predictive Value of 92% for the ACL not being normal. Conclusion: There is a “watershed” in ACL condition between Ahlback grade 3 and 4. Prostheses requiring Normal or Intact ACL’s should only be performed if Ahlback grade is ≤3. Standard radiographs can reliably predict ACL condition with high Positive and Negative predictive values

Introduction: Anthropometric anatomical factors may influence mechanical and functional stability of joints. An increased posterior tibial slope places the anterior cruciate ligament at a theroretical biomechanical disadvantage. An increased posterior tibial slope can potentially alter forces during landing tasks by either increasing anterior tibial translation and/or ACL loading. The purpose of this study is to investigate the relationship between posterior tibial slope and anterior cruciate ligament injuries. It is hypothesized that subjects with an ACL injury have an increased posterior tibial slope compared to a normal population. Methods: Posterior tibial slope in 211 patients (154 male, 57 female) aged 15–49 who underwent anterior cruciate ligament reconstruction was measured using the posterior tibial cortex as reference. A matched control group was used for comparison. Results: The average posterior tibial slope in the ACLR population was 6.1 degrees while the control group had average values of 5.4 degrees. This finding nearly reached statistical significance (p=0.057). In the male population average values were 5.5 degrees in the ACLR group and 5.9 in the control group. This was not significant (p=0.21). However there was a significant difference (p=0.04) in the female group. ACLR females had higher values 6.5 degrees whereas the control group had average values of 5.2 degrees. Discussion: Increased posterior tibial slope decreases the inclination of the ACL and potentially decreases vector force during dynamic tasks. It may further result in suboptimal length-tension relationships of agonistic muscles, increases in electromechanical delays and result in lower force development further leading to increased vector forces on the ACL. Posterior tibial slope angles were slightly smaller than with other published studies. However by using the posterior tibial cortex as reference an average of 3 degrees must be added to the measured values. We could not confirm the results of previous studies demonstrating an increased degree of posterior tibial slope in ACL injured patients. However we demonstrated a significant difference in tibial slope in females. Based on our results an increased posterior tibial slope is not a risk factor in males but possibly contributes to ACL injuries in females. Increased posterior tibial slope may be one of the reasons why females have a higher incidence of ACL injuries

INTRODUCTION. In native knees anterior cruciate ligament (ACL) and asymmetric shape of the tibial articular surface with a convex lateral plateau are responsible for differential medial and lateral femoral rollback. Contemporary ACL retaining total knee arthroplasty (TKA) improves knee function over ACL sacrificing (CR) TKA; however, these implants do not restore the asymmetric tibial articular geometry. This may explain why ACL retention addresses paradoxical anterior sliding seen in CR TKA, but does not fully restore medial pivot motion. To address this, an ACL retaining biomimetic implant, was designed by moving the femoral component through healthy in vivo kinematics obtained from bi-planar fluoroscopy and sequentially removing material from a tibial template. We hypothesized that the biomimetic articular surface together with ACL preservation would better restore activity dependent kinematics of normal knees, than ACL retention alone. METHODS. Kinematic performance of the biomimetic BCR design (asymmetric tibia with convex lateral surface), a contemporary BCR implant (symmetric shallow dished tibia) and a contemporary CR implant (symmetric dished tibia) was analyzed using KneeSIM software. Chair-sit, deep knee bend, and walking were analyzed. Components were mounted on an average bone model created from magnetic resonance imaging (MRI) data of 40 normal knees. Soft-tissue insertions were defined on the average knee model based on MRI data, and mechanical properties were obtained from literature. Femoral condyle center motions relative to the tibia were tracked to compare different implant designs. RESULTS. During simulated chair-sit, the biomimetic BCR implant showed knee motion similar to that reported for healthy knees in vivo including medial pivot rotation with greater rollback of the lateral femoral condyle (5 mm medial vs. 11 mm lateral). The CR implant showed posterior femoral subluxation in extension, paradoxical anterior sliding until 60° flexion followed by limited rollback until 105° with no medial pivot rotation. The conventional BCR implant reduced initial posterior shift of the femur in extension, however, medial pivot rotation and steady posterior rollback was not achieved. Similar trends were also found for deep knee bend activity. During walking the CR implant showed posterior subluxation in extension followed by anterior motion similar to the chair-sit activity. Both BCR implants showed less femoral excursion without posterior subluxation similar to published in vivo kinematics data for bi-uni patients. CONCLUSION. By simulating a variety of daily activities with different ranges of knee motion we were able to show that the ACL preserving biomimetic TKA implant could restore activity dependent normal knee kinematics unlike contemporary ACL retaining and ACL sacrificing implants. For chair-sit activity there was a clear medial pivot pattern for the biomimetic BCR design (unlike any other implant), while for lower flexion activities there was no medial pivot apparent in our simulations. These activity dependent knee motions are consistent with published in vivo kinematics and confirmed our hypothesis that biomimetic articular surface together with ACL preservation may be required to restore normal knee function. The biomimetic BCR design with its anatomical articular surface together with ACL preservation may provide patients with a more normal feeling knee following TKA surgery

Introduction: The use of the LARS (Ligament Augmentation and Reconstruction System. ®. , Corin) ligament for the surgical treatment of ACL deficiency has increased exponentially in Australia, particularly over the past 12 months. Given the well documented failure of synthetic ACL implants used during the 1980s, a review of the current literature regarding the LARS is required. Methods and Results: There is a paucity of current literature regarding the use of the LARS in the surgical management of ACL deficiency. 1 laboratory based, and 3 clinical publications were available for review. The transcriptions of 4 podium presentations were also available for review. Therefore, a total of 8 papers were analysed. The maximum duration of patient follow-up in any of the papers was 10 years. All papers presented results of at least 2 years follow up. In all papers, standardized outcome measures produced results equivalent to those obtained using traditional ACL reconstruction techniques. Complications were detailed in all papers, with each reporting the absence of synovitis in patients for whom the LARS had been used. Conclusion: Whilst there is insufficient long-term evidence to support the use of the LARS, the early results are promising. In particular, the problem of postoperative synovitis and synthetic ligament abrasion that led to the spectacular failure of early synthetic ACL designs appears to be absent in patients treated with the LARS. The LARS should be used in accordance with the strict patient selection criteria and technical guidelines recommended by the designing surgeon

Anthropometric anatomical factors may influence mechanical and functional stability of joints. An increased posterior tibial slope places the anterior cruciate ligament at a theroretical biomechanical disadvantage. An increased posterior tibial slope can potentially alter forces during landing tasks by either increasing anterior tibial translation and/or ACL loading. The purpose of this study is to investigate the relationship between posterior tibial slope and anterior cruciate ligament injuries. It is hypothesised that subjects with an ACL injury have an increased posterior tibial slope compared to a normal population. Posterior tibial slope in 211 patients (154 male, 57 female), aged 15–49, who underwent anterior cruciate ligament reconstruction was measured using the posterior tibial cortex as reference. A matched control group was used for comparison. The average posterior tibial slope in the ACLR population was 6.1 degrees, whilst the control group had average values of 5.4 degrees. This finding nearly reached statistical significance (p=0.057). In the male population, average values were 5.5 degrees in the ACLR group and 5.9 in the control group. This was not significant (p=0.21). However, there was a significant difference (p=0.04) in the female group. ACLR females had higher values 6.5 degrees whereas the control group had average values of 5.2 degrees. Increased posterior tibial slope decreases the inclination of the ACL and potentially decreases vector force during dynamic tasks. We could not confirm the results of previous studies demonstrating an increased degree of posterior tibial slope in ACL injured patients. However, we demonstrated a significant difference in tibial slope in females. Based on our results, an increased posterior tibial slope is not a risk factor in males but possibly contributes to ACL injuries in females. Increased posterior tibial slope may be one of the reasons why females have a higher incidence of ACL injuries

Anteromedial osteoarthritis is a distinct phenotype of osteoarthritis. The arthritic lesion on the tibia is localised to the anteromedial quadrant with an intact ACL. Deficiency of the ACL leads to a progression to tricompartmental disease. Within the spectrum of intact ACL a varying degree of ligament damage is seen. Our aim was to correlate the progression of ACL damage to the geographical extent of disease and the degree of cartilage loss on the tibial plateau. We systematically digitally mapped 50 tibial plateau resection specimens from clinical photographs of patients undergoing unicompartmental arthroplasty, additionally the damage to their ACL was graded (0: normal, 1:synovium loss, 2:longitudinal splits). These images were imported into image analysis software. Accurate measurements were made of the dimensions of the specimen. Measurements included the AP distance to the anterior and posterior aspect of the lesion, and the distance to the start of the macroscopically non damaged cartilage. The areas of cartilage damage and full thickness loss were also recorded. The results were represented as a % of total area to account for variation in size of the resection specimens. We compared % of full thickness loss in patients with normal to those with damaged, but functionally intact ligaments. All specimens had a similar macroscopic appearance. A significant difference was seen with the progression of ACL damage and area of eburnation of bone. Using an unpaired t test, a significant difference in area of % full thickness cartilage loss (P=0.047) was seen between patients with a normal and longitudinal splits within their ACL. No correlation between the clinical status of the ACL and start or finish point of cartilage loss on the tibial plateau. We surmise that the progression from anteromedial to tricompartmental osteoarthritis of the knee may be related to the graduated damage of the ACL

Purpose: Previous research has reported that increasing the posterior tibial slope through an opening wedge osteotomy results in an anterior shift in the position of the tibia relative to the femur. However, the effect of this on anterior cruciate ligament (ACL) strain remains insufficiently understood. The purpose of this study was to examine the relationship between tibial slope and tibial translation, as well as between tibial slope and ACL strain. It was hypothesized that increasing the posterior tibial slope would result in an increase in anterior tibial translation thereby increasing strain in the ACL. Methods: Five cadaveric knees were subjected to a randomized experimental design study. One knee was excluded due to failure of a strain gauge during experimentation, resulting in data for four knees. The femoral and tibial portions of the knee were potted with PMMA and fixed using fixation pins. An anterior-based osteotomy was performed with no osteotomy plate present. A strain gauge was then placed in the anteromedial bundle of the ACL. Each knee was mounted at a flexion angle of 15° and loaded with various combinations of A-P loads (18N, 108N, 209N) and axial loads (216N, 418N), according to the study design. Osteotomies of 5mm and 10mm were then performed and measurements of strain and tibial translation were taken after each according to the study design. Tibial slopes were determined through lateral fluoroscopic imaging. Results: As posterior tibial slope increased, anterior tibial translation increased as anticipated. However, contrary to expectations, as posterior slope increased, ACL strain decreased. One explanation for this result could be that by performing the osteotomy, the insertions sites of the ACL were being moved closer together resulting in increased ACL laxity. At higher slope angles, translation levels off, suggesting constraint of some tissue besides the ACL. Conclusions: Although increasing the tibial slope through opening wedge osteotomy leads to an anterior tibial translation, there is no increase in strain on the ACL. Further studies are needed to examine the effect of opening wedge osteotomy on other soft tissue restraints of the knee

Controversies about the management of injuries to the soft tissue structures of the posteromedial corner of the knee and the contribution of such peripheral structures on rotational stability of the knee are of increasing interest and currently remain inadequately characterised. The posterior oblique ligament (POL) is a fibrous extension off the distal aspect of the semimembranosus that blends with and reinforces the posteromedial aspect of the joint capsule. The POL is reported to be a primary restraint to internal rotation and a secondary restraint to valgus translation and external rotation. Although its role as a static stabiliser to the medial knee has been previously described, the effect of the posterior oblique ligament (POL) injuries on tibiofemoral stability during Lachman and pivot shift examination in the setting of ACL injury is unknown. The objective of this study was to quantify the magnitude of tibiofemoral translation during the Lachman and pivot shift tests after serial sectioning of the ACL and POL. Eight knees were used for this study. Ligamentous constraints were sequentially sectioned in the following order: ACL first, followed by the POL. Navigated mechanised pivot shift and Lachman examinations were performed before and after each structure was sectioned, and tibiofemoral translation was recorded. Lachman test: There was a mean 6.0 mm of lateral compartment translation in the intact knee (SD = 3.3 mm). After sectioning the ACL, translation increased to 13.8 mm (SD = 4.6; P<0.05). There was a nonsignificant 0.7 mm increase in translation after sectioning the POL (mean = 14.5 mm; SD = 3.9 P>0.05). Mechanised pivot shift: Mean lateral compartment translation in the intact knee was −1.2 mm (SD = 3.2 mm). Sectioning the ACL caused an increase in anterior tibial translation (mean = 6.7 mm; SD = 3.0 mm; P<0.05). No significant change in translation was seen after sectioning the POL (mean = 7.0 mm, SD = 4.0 mm; P>0.05). Sectioning the POL did not significantly alter tibiofemoral translation in the ACL deficient knee during the Lachman and pivot shift tests. This study brings into question whether injuries to the POL require reconstruction in conjunction with ACL reconstruction. More studies are needed to further characterise the role of the injured POL in knee stability and its clinical relevance in the ACL deficient and reconstructed knee

Controversies about the management of injuries to the soft tissue structures of the posteromedial corner of the knee and the contribution of such peripheral structures on rotational stability of the knee are of increasing interest and currently remain inadequately characterised. The posterior oblique ligament (POL) is a fibrous extension off the distal aspect of the semimembranosus that blends with and reinforces the posteromedial aspect of the joint capsule. The POL is reported to be a primary restraint to internal rotation and a secondary restraint to valgus translation and external rotation. Although its role as a static stabiliser to the medial knee has been previously described, the effect of the posterior oblique ligament (POL) injuries on tibiofemoral stability during Lachman and pivot shift examination in the setting of ACL injury is unknown. The objective of this study was to quantify the magnitude of tibiofemoral translation during the Lachman and pivot shift tests after serial sectioning of the ACL and POL. Eight knees were used for this study. Ligamentous constraints were sequentially sectioned in the following order: ACL first, followed by the POL. Navigated mechanised pivot shift and Lachman examinations were performed before and after each structure was sectioned, and tibiofemoral translation was recorded. Lachman test: There was a mean 6.0 mm of lateral compartment translation in the intact knee (SD = 3.3 mm). After sectioning the ACL, translation increased to 13.8 mm (SD = 4.6; P<0.05). There was a nonsignificant 0.7 mm increase in translation after sectioning the POL (mean = 14.5 mm; SD = 3.9 P>0.05). Mechanised pivot shift: Mean lateral compartment translation in the intact knee was −1.2 mm (SD = 3.2 mm). Sectioning the ACL caused an increase in anterior tibial translation (mean = 6.7 mm; SD = 3.0 mm; P<0.05). No significant change in translation was seen after sectioning the POL (mean = 7.0 mm, SD = 4.0 mm; P>0.05). Sectioning the POL did not significantly alter tibiofemoral translation in the ACL deficient knee during the Lachman and pivot shift tests. This study brings into question whether injuries to the POL require reconstruction in conjunction with ACL reconstruction. More studies are needed to further characterise the role of the injured POL in knee stability and its clinical relevance in the ACL deficient and reconstructed knee

Introduction: By characterising ACL strain behaviour in intact and posteromedial deficient knees under a variety of external loading conditions the aim of this work was to demonstrate whether posteromedial corner insufficiency could increase strain in an ACL reconstruction graft. Materials and Methods: 15 fresh cadaveric knees were mounted on a materials testing machine. A miniature extensometer was implanted onto the anteromedial bundle (AMB) of the ACL. The knees were loaded in: Anterior draw (150N), varus/valgus rotation (5Nm) and internal/external rotation (5Nm) at 0°, 15°, 30°, 60° & 90° flexion. The posteromedial corner structures – posteromedial capsule, superficial MCL and deep MCL – were cut sequentially and the effect AMB strain measured. Results: Strain data for analysis was available for 11 intact knees: Tibial internal rotation produced increased strain in the AMB at all angles of knee flexion (p< 0.05). Tibial external rotation reduced ACL strain at 0° to 30° (p< 0.05) and 60° to 90° knee flexion (p> 0.05). Anterior loading of the tibia increased AMB strain. With the tibia free to rotate, strain was highest at 90 degrees knee flexion (5.3%) and lowest at 0 degrees (1.6%). Fixed internal and external tibial rotation reduced AMB strain produced by a 150 N anterior drawer force at all knee flexion angles. Strain data for analysis was available for 6 Posteromedial Corner deficient knees:. With the tibia free to rotate or when locked in internal rotation, cutting the posteromedial structures had no effect on AMB strain with a 150 N anterior drawer force applied to the tibia. However, with the tibia locked in external rotation, cutting the posteromedial structures increased AMB strain at 60 and 90 degrees flexion. This difference however did not reach statistical significance. Conclusions: The findings that division of the posteromedial structures may cause increased AMB strain and that there is significant load sharing by the peripheral ligamentous structures, suggests that valgus and rotational stresses to the knee in a patient with posteromedial corner insufficiency could lead to increased strain in the ACL graft, that would otherwise have been restrained by the posteromedial corner complex. It would also therefore seem to be appropriate to recommend the use of a collateral ligament brace in the post-operative period when combining a repair of the posteromedial structures and the ACL, to again prevent excessive graft strains

Objective: The treatment of Anterior Cruciate Ligament (ACL) instability resulting from incomplete tears or elongation in continuity has been historically treated either conservatively or by graft replacement. The literature is sparce with regard to alternative reparative surgical treatment of this condition. We report our early experience using a thermal shrinkage treatment on 11 consecutive knees suffering from this condition in patients experiencing continuing instability. Methods: Eleven patients underwent ACL electrothermal monopolar treatment at our institution between 1998 and 1999. All of these patients presented a difference of 6 mm or more when comparing the involved to the uninvolved side using KT-1000 evaluation. They showed ACL incomplete tears or elongation in continuity at the time of the arthroscopic evaluation. A single electrothermal device (Oratec, Oratec Interventions, Menlo Park, CA) was used in all of the cases. Rehabilitation protocol included immobilization and non-weight-bearing for 6 weeks. A one-year minimum follow-up study was conducted in all of the patients following the IKDC rating system. Results: The overall outcome at a one-year minimum F.U. was normal or nearly normal in all of the patients. They also showed a 30 pound side to side difference less than 5 mm. They were allowed to return to running 3 months after ACL shrinkage and to full unrestricted sports after 6 months. Conclusions: The thermal repair of ACL-insufficient knees represents an emerging alternative treatment to standard techniques. The primary controindication for this technique is discontinuity of the ligament. Particular attention must be paid to patient compliance during ligament healing in its early stages

Purpose: To document healing of the anterior cruciate ligament. Introduction: Conventional wisdom holds that the anterior cruciate ligament (ACL) does not heal. In an athlete the ACL deficient knee is likely to be symptomatic and lead to functional instability. This has led to the belief that all ACL tears in the active athlete require reconstruction. Some ACL tears in recreational athletes are successfully treated conservatively with activity modification and bracing. A literature search was performed which found three articles on ACL healing. These articles felt that complete ACL tears could heal if patients were properly braced and rehabilitated. Materials and Methods: At the Carleton University Sports Medicine Clinic we retrospectively reviewed ACL tears diagnosed by the Lachman, pivot shift, and KT-1000 arthrometer testing. We then examined those whose clinical exam became stable by the same three tests. The latest follow up exam was performed by the same examiner (P.P). At the follow up exam, knee function was evaluated with the expanded IKDC form. Results: Nine patients were found to be asymptomatic and stable after an initial diagnosis of an ACL tear. In follow up the Lachman test had a good endpoint, the pivot shift was normal and the KT – 1000 manual max was less than 3mm. The IKDC results showed 3/9 were grade A, 5/9 were grade B and 1/9 was grade C. The clinical implication: ACL tears should be treated initially conservatively since in a small percentage of patients, the ACL tear can heal

A group of Athletes with torn ACL (insufficient knees) suffer from bowleg or valgus knees. AT this points we don't have a general consensus in literature. This study is based on a randomized clinical trial with double blind randomization of young athletes not more than 36 years and not over than 82 kg weight. Each groups contained by 30 patient with ACL deficient knees and bowlegs with Mikolicz line on the most medical 1/3rd of medial condyle of femur on worse. with follow up of 2 to 6 years and in all three groups we tried to control the knee by KT 2000, Tegner's score and IKDC and lysholm's scores in all patient. At final exam we had chance to meet 29 patients with simultaneous HTO (open wedge + plate) and ACL – R and 26 patients with HTO 1st, and 6 months later for ACL – R and only 24 patients with ACL – R 1st, 6 patients of this group and a patient of HTO 1st didn't show for rest of their procedures. Conclusion: by P value (o.o1) Simultaneous ACL – R and HTO had higher rate of success and between two other groups except osteoarthritis out come in short period of time (2 – 6 years) HTO had better results than ACL –R 1st with P value of (0.05)

Aim. The aim of this study is to outline the steps and techniques required to create a patient specific 3D printed guide for the accurate placement of the origin of the femoral tunnel for single bundle ACL reconstruction. Introduction. Placements of the femoral tunnels for ACL reconstruction have changed over the years. Most recently there has been a trend towards placing the tunnels in a more anatomic position. There has been subsequent debate as to where this anatomic position should be. The problem with any attempt at consensus over the placement of an anatomic landmark is that each patient has some variation in their positioning and therefore a fixed point for all has compromise for all as it is an average. Our aim was to attempt to make a cost effective and quick custom guide that could allow placement of the center of the patients’ newly created femoral tunnel in the mid position of their contralateral native ACL femoral footprint. Materials & Methods. We took a standard protocol MRI scan of a patient's knee without ACL injury transferred the DICOM files to a personal computer running OsiriX (Pixmeo, Geneva, Switzerland.) and analysed it for a series of specific anatomical landmarks. OsiriX is an image processing software dedicated to DICOM images. We marked the most posterior edge of the articular cartilage on the lateral wall of the notch (1), the most anterior edge of the articular cartilage of the lateral wall of the notch (2), the most inferior edge of the articular cartilage of the lateral wall of the notch (3) and the center of the femoral footprint of the native ACL. Distances were then calculated to determine the position relative to the three articular cartilage points of the center of the ACL footprint. These measurements and points were then utilised to create a 3D computer aided design (CAD) model of a custom guide. This was done using the 3D CAD program 123Design (Autodesk Ltd., Farnbourgh, Hampshire). This 3D model was then exported as an STL file suitable for 3D printing. The STL file was then uploaded to an online 3D printing service and the physical guide was created in transparent acrylic based photopolymer, PA220 plastic and 316L stainless steel. The models created were then measured using vernier calipers to confirm the accuracy of the final guides. Results. The MRI data showed point 1 (AP), point 2 (distal-ACL), point 3 (Ant-ACL) and point 4 (Post-ACL) at a distance of 59.83, 15, 45.8 and 13.9 respectively. For the 3D CAD model, points 1, 2, 3 and 4 were at a distance of 59.83, 15, 45.8 and 13.9 respectively. For the PA220 plastic model, points 1, 2, 3 and 4 were at a distance of 59.86, 14.48, 45.85 and 13.79 respectively. For the 316L stainless steel model, points 1, 2, 3 and 4 were at a distance of 59.79, 14.67, 45.64 and 13.48 respectively. Lastly, for the photopolymer model, points 1, 2, 3 and 4 were at a distance of 59.86, 14.2, 45.4 and 13.69 respectively. The p-value comparing MRI/CAD vs. PA220 was p=0.3753; for the comparison between MRI/CAD vs. 316L, p=0.0683; lastly for the comparison between MRI/CAD Vs. Photopolymer, p=0.3450. The models produced were accurate with no statistical difference in size and positioning of the center of the ACL footprint from the original computer model and to the position of the ACL from the MRI scans. The costs for the models 3D printed were £3.50 for the PA220 plastic, £15 for the transparent photopolymer and £25 for the 316L stainless steel. The time taken from MRI to delivery for the physical models was 7 days. Discussion. Articles regarding the creation of 3D printed custom ACL guides from the patients contralateral knee do not feature in current literature. There has been much research on custom guides for other orthopaedic procedures such as in total knee arthroplasty for the accurate placement of implants. There has also been research published on the creation of custom cutting jigs from CT for complex corrective osteotomy surgery. This study serves as the first step and a proof of concept for the accurate creation of patient specific 3D printed guides for the anatomical placement of the femoral tunnel for ACL reconstruction. The guides were easy to create and produce taking only a week and with a cost of between £3.50 and £25. The design of the guides was to allow the tip of a standard Chondro Pick (Arthrex inc., Naples, Florida.) (3mm) used to mark the starting point of the femoral tunnel to enter through the guide. The next step for this research is to create guides from cadaveric matched knees and utilise the guides to carry out the creation of the femoral tunnels and to analyse of the placement of the tunnel in relation to the contralateral knee

Aims: ACL lesion is one of the most frequent event in sport injuries. It is generally a complete lesion which does not evolve to a spontaneous healing. In particular, after non surgical treatment, ACL often repairs on PCL with a residual articular laxity. A healing response technique has been described to treat ACL incomplete tears in skeletally immature athletes. Our technique is based on microfractures next to the ACL femoral insertion to obtain a scar reinforcement thanks to the action of mes-enchymal stem cells. Methods: The authors report their experience using the same surgical technique and rehabilitation protocol in patients selected by type of lesion, age and time from injury. The authors selected for the study young-middle age active patients, with incomplete ACL lesion: 27 patients (mean age of 23 years) have been evaluated, inclusion criteria was Lachman test < 1 cm, negative Jerk test and a proximal partial tear of ACL on MRI. Before and after surgery the patients have been evaluated using KT1000, MRI, clinical examination and Lysholm score with a 3 years average follow up. Results: Clinical examination showed a significative improvement in Lysholm score from 63 to 85 and a minor anterior tibial translation measured with KT1000 (from a mean difference between the two legs of 5 mm preoperatively to 2 mm postoperatively). In only one case the ACL didn’t seem to heal and was necessary the traditional reconstruction. MRI at one year pointed out a reparative healing in almost all cases. Conclusions: according to these results the healing response procedure can restore a subjective and objective stability and knee function, with proper patient selection and strictly following the rehabilitation protocol despite of age and time of lesion

Despite several anatomical and neurophysiological studies have demonstrated the sensory role of anterior cruciate ligament (ACL), it is still unclear how significant the absence of the ACL will affect knee proprioception. Also because some mechanoreceptors has been discovered in the injured bundle commonly resected during ACL reconstruction. In fact recently it has been observed that subjects with long standing ACL deficiency have not a knee joint pro-prioceptive deficit as measured by threshold of passive movement detenction and the ability to reproduce flex-ion angles, commonly accepted methods. The aim of this study was to investigate the possibility to recognize a sensorial and behavior impairment in ACL deficient knee. Through a computerized device the kinaesthetic data were collected from 120 sportsmen between 20–49 years (mean 32,4) affected by unilateral isolated ACL injury diagnosed with MRI and verified arthroscopically. The protocol consisted in four exercises, two bipodal on static and dynamic stance and two monopodal on healthy and injured lower limb. The balance index was divided in four areas on two dimensional plane for a qualitative assessment. The mathematical and statistical elaboration revealed on bipodal static test a significant and costant displacement on the left side indipendently by the injured side and age. The kinaesthetic awarness was confirmed also by a significant increase of balance index in all exercises. Further studies are necessary to a better knowledge as a possible new tool. In conclusion, this is the first report of a typical sensorial and behavior impairment in ACL deficient knee with intriguing clinical significance

Purpose: Ultrastructural analysis of PT graft for ACL single bundle reconstruction. Materials and methods: Arthroscopical biopsies for new meniscal lesions at 6-12-24mm-5-10 ys. All cases with IKDC normal/nearly normal and KT2000 excellent/good. Samples prepared with Karnowsky fixing and urani-lacetate solution. Fibril diameter and transversal area measured by LEICA QUIN in 5 cuts randomly selected for each sample. Results: 6 months biopsy showed severe P.T. modifications, with a decrease of larger fibrils, substituted with smaller one with plenty of extra cellular matrix. Oxitalan fibers, macrophagic cells and tenocytes were observed. At 12 months compact fascicles of small fibrils (50–60 nm) divided the larger one, similar to a normal tendon. At 24 months graft modifications were increased with wide compact fasciclesvariously oriented. At 5 and 10 years the modifications were similar to those observed at 2 years, with the graft not completely transformed in native ACL structure. Discussion: The results showed that PT graft used for ACL single bundle reconstruction certainly undergoes a neoligamentization process up to two years. At longer follow-up the foresaw complete remodelling in a normal ACL was not observed. Heterogeneous fibrils presence suggests incomplete ligamentization or its impossible complete realization in single bundle ACL reconstructions

Purpose: No conventional surgical technique for ligament reconstruction can be used in all cases to achieve ideal position of the transplant. Navigation systems without visualisation of the anterior cruciate ligament should meet the requirements. This is an operative strategy based on one or more computer assisted procedures enabling ligament reconstruction without the need for conventional pre- per, or postoperative imaging. The principle is based at the present time on the use of a station (computer, localisers, display screen, command pedal) used for processing data (spatial measurements and positioning) delivered by markers fixed on rigid bodies and tools (palpation, aiming tools). Material and methods: This study was conducted on ten cadaver knees. Each knee was instrumented with the station. Joint kinetics were recorded with and without the ACL and after harvesting the transplant: patellar ligament and hamstring ligaments. Bone morphing was used to draw the tibial and femoral surfaces. Two types of aiming tools were tested by recording the data points issuing from the tibial output and the femoral input. The position of the femoral and tibial holes was determined to achieve the smallest anisometry and absence of notch conflict. Isometric zones were compared with the anatomic zones of the ACL. We also compared the position of the transplant determined by the computer and that determined according to the methods of conventional arthroscopy. An x-ray of each knee was obtained to compare with data in the literature concerning the advised position of the femoral and tibial holes with that established by the computer navigation system. Each knee was tested with KT1000 before and after surgery. Results: The precision of bone morphing was 0.1 mm. Anisometric curves were compatible with drilling holes calibrated to the size of the implant in four knees. The operator used the navigation system to determine the point of the femoral hole in six knees. The system then calculated the point of the tibial hole automatically eliminating the risk of notch conflict. The anisometric values were less than 2 mm; the distance roof of the notch/anterior border of the transplant was calculated as a function of the radius of the transplant (3.5–5 mm). The position of the tibial hole given by the computer system was always more medial than that given by the tibial aiming tools. The position of the femoral tunnel was always more anterior than that given by the femoral aiming tools. The postoperative KT1000 values were identical to the preoperative values. Discussion: Navigation without visualisation of the ACL is able to position the ACL in an isometric plane or better in an “anatomometric” plane, to inscribe the joint orifice of the tibial hole on the projection of the anterior arch of the notch on the tibial surface, to draw in real time the isometric femoral map on the notch in order to centre the joint orifice of the tibial hole as well as the corresponding laxity map, to indicate on the femoral notch the point which will be the centre of the joint orifice of the femoral hole, to draw the isometric curve of a given fibre and its corresponding laxity map, and to detect and allow the treatment of any transplant-notch conflict

Previous Anterior Cruciate Ligament (ACL) reconstruction is currently a bar from entry to the Royal Marines and Royal Navy, whilst the British Army allows recruits to join if asymptomatic 18 months post ACL reconstruction. However current Royal Marines policy is to rehabilitate recruits who sustain an ACL disruption in training. We retrospectively analysed the rehabilitation times and pass out rate of Royal Marines who had an ACL disruption during recruit training over an 8 year period. 12 recruits sustained an ACL disruption during recruit training in the study period, giving an incidence of around 1.5/1000 recruits. 9 Patients underwent ACL repairs in training, with 1 patient leaving and rejoining post repair and later successfully passed out. 2 patients were treated conservatively. Of the 12 ACL sustained in training 8/12 (67%) passed out. None of the patients treated conservatively passed out. The mean time out of training for successful recruits was 51.6 weeks (95% CI 13.1) mean rehabilitation time post ACL reconstruction for successful recruits was 36.7 weeks (95% CI 12.5). Mean time to discharge for unsuccessful recruits 63.2 weeks (95% CI 42.4). In the operative group 1/10 left due to failure to return to training and 1/10 left through unrelated reasons. Current costing for recruit training is £1800 per week per recruit. ACL injuries are not common in Royal Marine Training, and reconstruction is not a bar to completing Royal Marine basic training. We estimate that it costs around £100,000 per-injured recruit, to maintain a policy of rehabilitating ACL injured recruits in Royal Marines training. Further research into the long-term employability or Royal Marines sustaining an ACL injury in training is required

Given their role in reducing anterior tibial translation, the recruitment patterns and viscoelastic properties of the hamstring muscles have been implicated as neuromuscular factors contributing to the ACL gender bias. Nevertheless, it is uncertain whether patterns of aberration displayed by the female neuromuscular system significantly alters the antagonist moments generated by the hamstrings during maximal effort knee extension. The purpose of the current study was to examine the effect of gender on hamstring antagonist moments in order to explain the higher ACL injury rates in females. Eleven females (age 30.6 ± 10.1 years, mass 62.1± 6.9 kg, height 165.9 ± 4.6) and 11 males (age 29.0 ± 8.2 years, mass 78.6± 14.4 kg, height 178.5± 6.2) were recruited as subjects. Surface electrodes were placed over the semitendinosus (ST) and biceps femoris (BF) muscles of the dominant and non-dominant limbs. Each subject performed two sets of five maximal extension and flexion repetitions at 180-1. EMG, isokinetic torque and knee displacement data were sampled at 1000Hz using an AMLAB data acquisition system. Average hamstring antagonist torque data across the range of knee flexion for female subjects was significantly higher (%Diff=24%) than for the male control subject. Statistical analyses revealed a significant main effect of gender (F = 4.802; p = 0.036). Given that females possess a more compliant ACL and hamstring musculature, compared with their male counterparts, an augmented hamstring antagonist may represent a compensatory neuromuscular strategy to increase knee stiffness to control tibial translation and ACL strain. The results of this project suggest that it is unlikely that gender-related differences in hamstring antagonist torque is one of the predisposing factors contributing to the higher ACL injury rates in females

Tibial rotation and translation provide important stability parameters after ACL reconstruction. An accurate tool for a combined pre- intra- and postoperative stability measurement is not in clinical use so far. Navigation of the drill canals for the ACL placement and evaluation of possible impingement problems has been introduced for some years already, while measurement of the tibial translation and rotation is only available for a short time and only available for a few navigation modules. Navigation provides an accuracy of 1mm/1°, therefore navigated measurement of tibial rotation and translation were evaluated in this study with a new developed mechanical device and directly compared to conventional measurement techniques. Accuracy of navigation was compared with the KT1000 for the anterior-posterior (AP) translation and to a new developed goniometer tool concerning the rotational range of motion. Comparative tests included plastic whole leg models and specimens. Tests were repeated with intact and dissected ACL′s. A conventional navigation system (Vector Vision, Brainlab, Germany) was used in all cases. This included software developed for fluoroscopy based navigated ACL reconstruction. The following knee kinematics were detectable with the navigation system: Flexion/Extension degrees of the knee joint (°); AP translation of the tibia in relation to the femur (mm); Axial tibial rotation relative to the femur (°). Validation of Navigation: first neutral tibial rotation was defined and marked in the knee joint in neutral position. All rotational measurements were done with a new developed goniometer tool and compared to the navigated technique. Then the knee was rotated externally until 45° (maximum) and internally 45° (maximum), by single 2.5° steps. These measurements were repeated in 0°, 30°, 60° and 80° knee flexion. All tests were repeated three times and performed by 3 different observers. A total of 1296 measurements were done. Measurements of the tibial translation were compared with the KT 1000 for the specimen testing. Results revealed: accurate navigated measurement of tibial rotation in plastic and specimen models; variation of absolute AP translation values between KT1000 and navigation; variation of the AP translation corresponding to the ACL condition; increased range of total tibial rotation after dissecting the ACL compared to the intact ligament. Restoration of the rotational stability and limiting of the AP translation is necessary to provide normal knee kinematics after ACL reconstructions. Intraoperative measurements of these stability parameters are demanding and so far not established with navigation systems or conventionally. As our results show, navigation offers an accurate technique for measurement of the AP translation and rotation of the knee with intact and dissected ACL’s under laboratory conditions. General use in the evaluation of a successful ACL reconstruction becomes possible intraoperative and might be reproducible for further measurements. Clinical studies are needed to improve our results

Purpose: Gait analysis has become an innovative approach to assess the biomechanical adaptations due to an ACL injury. However, interpreting the large amount of data collected often requires an expert. Therefore, there is a need to develop an automatic method capable to distinguish kinetic pattern of an ACL deficient patients from an asymptomatic population. Method: 26 ACL deficient patients and 30 asymptomatic participants took part in a treadmill gait analysis. 3D ground reaction forces (vertical, medio-lateral and anterior-posterior) were collected using the ADAL 3D treadmill. Features were extracted from the 3D ground reaction forces as a function of time and then classified by the nearest neighbour rule using a wavelet decomposition method. The classification method was tested on our data base of 56 participants. Results: The proposed classification method obtained an accuracy of 90%. The classification accuracy per class was higher for the ACL deficient group allowing classifying correctly 25 out of 26 ACL deficient patient. 25 out of the 30 asymptomatic participants were properly classified. Conclusion: This study shows that an automatic objective computer method could be used in a clinical setting to help diagnose an anterior cruciate ligament injury during a gait analysis evaluation. Future studies should apply this method on a larger database including data from patients with other musculoskeletal pathologies to help diagnose other injuries

Anterior cruciate ligament (ACL) reconstruction allows overall good results, but there is still a significant rate of failure. It is well accepted that the main reason for ACL reconstruction failure is a misplacement of tibial or femoral tunnels. Conventional techniques rely mainly on surgical skill for intra-operative tunnel placement. It has been demonstrated that, even by experienced surgeons, there was a significant variation in the accuracy of tunnel placement with conventional techniques. Navigation systems might enhance the accuracy of ACL replacement. 10 cadaver knees with intact soft-tissue and without any intra-articular abnormalities were studied. We used a non image based navigation system (OrthoPilot ®, Aesculap, Tuttlingen, FRG). Localizers were fixed on bicortical screws on the distal femur and on the proximal tibia. Both kinematic and anatomic registration of the knee joint were performed by moving the knee joint in flexion-extension and palpating relevant intra- and extra-articular landmarks with a navigated stylus. The most anterior, posterior, medial and lateral point of both tibial and femoral attachment of the ACL were marked with metallic pins. The navigated stylus was positioned on these points, and the system recorded its position in comparison to the bone contours. Subsequently, we performed conventional plain AP and lateral X-rays and a CT-scan, and measured the position of the pins in comparison to the bone contours. Finally, all measurements were made again with a caliper after disarticulating the knee joint. We calculated the center of the footprint as the mid-point between the four pins of both tibial and femoral attachment for each measurement technique. All measurements were expressed as percentages of the bone size to compensate for the different sizes. There were no significant difference in the paired measurements of the location of the ACL footprints on both femur and tibia between anatomic, radiographic, CT-scan and navigated measurements. There was a significant correlation between the paired measurements of the location of the ACL footprints on both femur and tibia with either measurement techniques. Anatomic measurement is the gold standard experimental technique for the positioning of the ACL foot-print, and CT-scan measurement is currently the gold standard technique in clinical situation. According to this reference, the position of ACL attachments on the tibia and on the femur can be accurately defined by the navigation system. Intra-operative measurement of the location of the bone tunnels during ACL replacement with this navigation system should be accurate as well

Good mid-term results of Oxford UKA (OxUNI) for anteromedial osteoarthritis (OA) were reported. The designers of prosthesis reported a 98% 10-year survival rate for a combined series of phase I and II, and these findings were supported by published results from other series, with 10-year survival ranging from 91% to 98%. In order to obtain good results, the designers of this prosthesis mentioned the importance of adhering to strict indication for OxUNI, especially only for OA cases with intact anterior cruciate ligament (ACL). OxUNI combined with ACL reconstruction (ACLR) is a viable treatment option for only young active patients, in whom the ACL has been primarily ruptured. On the other hand, it was not clear whether the result of OxUNI combined with ACLR for OA with secondary ruptured ACL was good. In this study we compare the short-term results of OxUNI combined with ACLR for OA with secondary ruptured ACL with that for usual OA with intact ACL. 382 OxUNI were performed at two hospitals by one surgeon between January 2002 and August 2005. Among those, 367 cases, followed over two years postoperatively (272 patients, women: 283, men: 84) were assessed. Follow up ratio was 96.1%. The mean patient age at the time of surgery was 72.0 (47~93) years. The mean follow-up period was 39.3 (24~67) months. Thirty three knees of OA were treated with OxUNI combined with ACLR, by using synthetic graft. Clinical results were assessed by the Oxford Knee Score (OKS) and active range of motion (ROM). Patients are asked a series of 12 questions, and their response scores range from 0 (worse) to 4 (best) for each, yielding an overall score range of 0–48. All living patients were contacted, and the status of the implant was established at the time of last follow from hospital records. We evaluate the survival rate for OxUNI with or without ACLR, using the endpoint of revision for any reason. The pre-and postoperative clinical scores were compared using the paired Student’s t-test. Survivor-ship curves were constructed using the Kaplan-Meier method, and survivorship between groups was compared using logrank and Wilcoxon methods. All analyses were performed using 95% confidence intervals and a P value of < 0.05 was considered significant. The mean OKS at final follow-up was 42.1 (preoperative; 21.7), and the mean active ROM was 125.2° (preoperative; 113.4°). OKS and active ROM were significantly improved. There were no significant differences in OKS and active ROM between OxUNI with ACLR and OxUNI with intact ACL. Fourteen knees among 367 knees were revised; nine for loosening of tibial component, four for dislocation of bearing and one for progression of lateral OA. Overall 5-year survival rate was 95.6%. When survival rate was assessed separately with or without ACLR, that of OxUNI with intact ACL was 96.7% and that of OxUNI with ACLR was 83.8%. There was significant worse survival rate between the two groups (P=0.0071). The 5-year survival rate for OxUNI with intact ACL was 96.7%, which was equivalent to those of original series from Oxford. However, 5-year survival rate for Oxford UKA with ACLR was 83.8% in our series. Four knees in nine of loosening of tibial component were replaced by OxUNI combined with ACLR. Therefore, even if ACL was reconstructed, the results of OxUNI for OA with secondary ruptured ACL was proved to be pessimistic. There was significantly worse survival rate for OxUNI with ACLR, compared with OxUNI with intact ACL. So we conclude that combined ACL reconstruction and OxUNI for anteromedial OA with secondary ruptured ACL is not recommended, which must be treated with TKA

To evaluate the clinical outcome of arthroscopic treatment of ACL with an Achilles tendon allograft in patient with acute rupture. 22 patients, between 2003 and 2006, with acute rupture of ACL, were treated with an Achilles tendon allograft. The mean age was 26 years. Patients were evaluated before and after surgery and at the latest follow-up with Noulis-Lahmann test and Pivot shift test. We also used IKDC score, Lysholm score and one leg stance test and functional reach test. Patients were also evaluated with Cybex II + and with plain radiographies. The mean follow-up time was 3.5 years. 90% of the patients had a negative pivot shift test and 95% of the patients had a score at Noulis-Lahmann test +1. The mean value of IKDC score was 88 (62–100) and the mean time of Lysholm score was 91 (75–100). Until the latest follow-up there were no clinical sighs of inflammation or graft rejection. Radiologic evaluation revealed no sign of tunnel enlargement. We believe that the use of a fresh-frozen allograft in the treatment of acute ACL ruptures is an effective procedure for the restoration of ligamentous stability of the knee

Separation of the ACL into anteromedial (AM) and posterolateral (PL) fibre bundles has been widely accepted. The bundles act synergistically to restrain anterior laxity throughout knee flexion, with the PL bundle providing the more important restraint near extension and its obliquity better restraining tibial rotational laxity. 10% of ACL injuries involve isolated rupture to one of these bundles causing patients to present with instability symptoms or pain. As knowledge about the influence of the ACL bundles on knee kinematics has increased, isolated reconstruction of either PL or AM bundle has been advocated. However only one cohort study of 17 patients has been presented in the clinical literature. KOOS (Knee Injury and Osteoarthritis Outcome Score) and IKDC (International Knee Documentation Committee Form) scores at 1yr post op were obtained for 12 patients who had undergone isolated ACL augmentation between 2007 and 2009. These were compared with previously published outcome scores for standard ACL reconstruction procedures. In addition examination under anaesthesia (EUA) assessments were analysed to see if a pattern of laxity for isolated AM and PL rupture could be determined. There were 5 patients with isolated AM bundle rupture and 7 with isolated PL bundle rupture. EUA analysis demonstrated that patients with isolated PL bundle rupture had increased pivot shift and Lachman test laxity, whereas the AM bundle rupture group had increased laxity with the anterior drawer test. Compared to previously published IKDC scores, there were no difference between isolated bundle augmentation and standard ACL reconstruction. However the KOOS scores showed significantly increased Sports function scores which was significantly better in the isolated bundle augmentations (93/100 v's 74/100). Differences between isolated AM and PL bundle reconstructions were not distinguishable. Isolated ACL bundle tears make up a significant proportion ACL injuries. Although technically more difficult than standard ACL reconstruction, isolated bundle augmentation appears to result in improved sports function when compared to standard ACL reconstruction

Meniscal tears commonly co-occur with ACL tears, and many studies address their side, pattern, and distribution. Few studies assess the patient's short-term functional outcome concerning tear radial and circumferential distribution based on the Cooper et al. classification. Meniscal tears require primary adequate treatment to restore knee function. Our hypothesis is to preserve the meniscal rim as much as possible to maintain the load-bearing capacity of the menisci after meniscectomy.

The purpose of this study is to document the location and type of meniscal tears that accompany anterior cruciate ligament (ACL) tears and their effect on patient functional outcomes following arthroscopic ACL reconstruction and meniscectomy.

This prospective cross-sectional observational study was conducted at AL-BASRA Teaching Hospital in Iraq between July 2018 and January 2020 among patients with combined ipsilateral ACL injury and meniscal tears. A total of 28 active young male patients, aged 18 to 42 years, were included. All patients were subjected to our questionnaire, full history, systemic and regional examination, laboratory investigations, imaging studies, preoperative rehabilitation, and were followed by Lysholm score 6 months postoperatively.

All 28 patients were males, with a mean age of 27 ± 0.14 years. The right knee was the most commonly affected in 20/28 patients (71.4%). The medial meniscus was most commonly injured in 11 patients, 7 patients had lateral meniscal tears, and 10 patients had tears in both menisci. The most common tear pattern of the medial meniscus was a bucket handle tear (36.4%), while longitudinal tears were the most frequent in the lateral meniscus (71.4%) (P-value = 0.04). The most common radial tear location was zone E-F (5/28, 17.8%), and the most common circumferential zone affected was the middle and inner third, reported in 50% of tears. Good and excellent outcomes using the Lysholm score after 6 months were obtained in 42.9% and 17.9% of patients, respectively. Better functional scores were associated with lateral meniscal tears, bucket handle tears, tears extending to a more peripheral vascular area, and if no more than one-third of the meniscus was resected (P-value = 0.002). Less favourable outcomes were reported in smokers, posterior horn tears, and when surgery was delayed more than 1 year (P-value = 0.03).

We conclude that there is a negative correlation between the amount of meniscus resected and functional outcome. Delayed ACL reconstruction increases the risk of bimeniscal tears. Bucket handle tears are the most common tears, mostly in the medial meniscus, while longitudinal tears are most common in the lateral meniscus. We recommend performing early ACL reconstruction within 12 months to reduce the risk of bimeniscal injuries.

ACL (anterior cruciate ligament) partial tears include various types of lesions, and an high rate of these lesions evolve into complete tears. Most of the techniques described in literature for the surgical treatment of chronic partial ACL tears, don't spare the intact portion of the ligament. Aim of this study was to perform a prospective analysis of the results obtained by augmentation surgery using gracilis and semitendinosus tendons to treat partial sub-acute lesions of the ACL. This technique requires an “over the top” femoral passage, which enables salvage and strengthening of the intact bundle of ACL. The study included 97 patients treated consecutively at our Institute from 1993 to 2004 with a mean injury-surgery interval of 23 weeks (12–39). Patients were followed up by clinical and instrumental assessment criteria at 3 months, 1 year and 5 years after surgery. Clinical assessment was performed with the IKDC form. Subjective and functional parameters were assessed by the Tegner activity scale. Instrumental evaluation was done using the KT-2000 instrument: the 30 pound passive test and the manual maximum displacement test were performed. We obtained good to excellent results in 95.9% of cases. We didn't observed recurrences in ligamentous laxity. We believe that the described technique has the advantage of being little invasive, compatible with the ACL anatomy, and enables very rapid functional recovery and return to sport

Introduction: Unicompartmental knee arthroplasty (UKA) is an increasingly popular procedure for young osteoarthritic patients whose age and activity levels preclude the use of a total knee arthroplasty (TKA). However, successful reconstruction using an unconstrained mobile bearing implant requires an intact and functioning ACL. Patients with isolated medial compartment OA and an absent ACL therefore provide a management dilemma for the treating surgeon. One option is to perform a combined ACL reconstruction and mobile bearing UKA. This paper presents early results of this new procedure using an Oxford UKA and ACL reconstruction using an autograft. Materials and Methods: Eleven patients who underwent one or two-staged ACL reconstruction and Oxford UKA for treatment of symptomatic medial compartment OA were reviewed at one year after surgery. The combined procedure required specific precautions and considerations; care had to be taken to place the tibial tunnel as far laterally as possible to avoid impingement of the graft by the tibial implant. Also, the presence of a posteromedial, rather than an anteromedial cartilage defect has the potential to reduce accuracy for placement of the initial tibial cut. Results: All patients were male with an average age of 49 years (range: 36 – 52) and mean follow up of 1.3 years. One patient needed revision to TKA due to infection. The objective and functional knee society scores improved pre to post operatively from 55 to 98, and 85 to 100, respectively. Conclusions: ACL reconstruction and simultaneous or staged UKA is a viable treatment option for patients with symptomatic medial compartment arthritis in whom the ACL is absent. Early results of this technically demanding procedure are encouraging but longer follow-up is required

We examined the vasoconstrictive actions of neuropeptide Y (NPY) in the intact medial collateral ligament (MCL) of normal and anterior cruciate ligament (ACL) -deficient rabbit knees. Blood flow to the surgically exposed MCL was measured using high-resolution laser speckle imaging (LSI) before and after topical administration of NPY and the α. 1. -adrenoreceptor agonist phenylephrine. In control rabbit knees, dose-dependent vasopressor responses were significantly greater than those in ACL-deficient knees, where there was little or no vasoconstrictor response. We conclude that chronic ACL deficiency markedly changes the vascular physiology and pharmacology of the surrounding articular tissues. To determine the effect of chronic ACL-deficiency on the physiologic responses to the potent sympathetic vasoconstrictor NPY. Abrogation of the vasoconstrictor response to both NPY and phenylephrine indicates that chronic ACL deficiency induces major changes in the vascular physiology of associated articular tissues. This study is the first to examine the vasoregulatory role of NPY in the MCL of unstable knee joints using LSI. In control rabbits, topical administration of NPY produced dose-dependent vasopressor responses (maximal effect at 10. −10. mol NPY). In ACL-transected knees there was little or no response to NPY (Figure 1). BIBP 3226 (selective NPY-Y1 receptor antagonist) did not affect the constrictor response to NPY in normal tissue, indicating that a receptor other than Y-1 mediates the response. Many neuropeptides participate in the post-traumatic inflammatory response. The sympathetic-derived NPY helps regulate inflammatory responses, is a vasoconstrictor and stimulates angiogenesis. Rupture of the ACL induces inflammation, hyperaemia and angiogenesis in the MCL. These changes in vascular physiology induced us to study the effect of ACL-deficiency on the actions of NPY in the MCL. Unoperated control (n=6) and 6-week ACL-transected (n=5) adult rabbits were used. Under anaesthesia, the MCL was surgically exposed and tissue blood flow was measured in real time using LSI as various doses and combinations of NPY, phenylephrine, and BIBP 3226 were administered topically. Possible causes of the reduced vasoconstrictive response to both NPY and phenylephrine in the MCL after 6wk of ACL-deficiency include change in the distribution or functionality of their specific receptors or inactivation of the associated down stream signalling pathways. Funding: This work was supported by funding from the CIHR and the Alberta Heritage Foundation for Medical Research. Please contact author for tables and/or graphs

Background: Several approaches to the ACL attachment and drilling methods exist, with little evidence of which method is the best. Hypothesis: The “Retrodrill” or an “inside-out” drilling technique result in uniform intra-articular tunnel mouths compared with standard “outside-in” conventional ACL drill bits. Study Design: Controlled laboratory study. Methods: Sixteen cadaveric knees were divided into Anterograde (A) and retrograde “Retrodrill” (R) groups and ACL tunnels drilled. The femoral tunnel mouths were moulded using PMMA, then Nylon rods of identical diameter containing 1mm diameter K-wires were inserted into the tunnels and AP and lateral X-rays taken. Matching laboratory experiments utilised 10 pig femurs and synthetic bone. Results: In group A, the mean difference between tunnels and their mouths was 1.6±0.5mm, compared with 0.3±0.2mm for Group R (p < 0.001). The mean femoral tunnel angulation in the sagittal plane for Group A was 45±10 degrees and 78±14 degrees for Group R (p< 0.001); and 30±12 degrees, and 71±12 degrees (p< 0.001) in the coronal plane respectively. There were similar ACL attachment hit rates from the groups. In porcine bone, tunnel mouth widening in the anterograde tibial group was 0.7±0.4mm, 0.04mm±0.1mm for the anterograde femoral group, and 0.06±0.1mm for the retrograde group (p< 0.001). In synthetic bone, the difference between the tunnels and their mouths was 0.8±0.8mm, 0.2±0.1mm and 0.1±0.1mm (p< 0.001) respectively. Conclusions: The “Retrodrill”, or an inside out antero-grade drilling technique, produced a more uniform tunnel with no difference in ACL attachment hits

Introduction. The anterior cruciate ligament (ACL) is one of the most common ligament injuries. Several ACL reconstructions exist and are consequently performed. An accurate and comprehensive description of knee motion is essential for an adequate assessment of these surgeries, in terms of restoring knee motion. Methods. We propose to compare these reconstructions thanks to an index of articular coherence. This index measures the instantaneous state surface configurations during a motion. More specifically, this refers to the position between two articular surfaces facing each other. First of all, the index has to refer to a position known to be physiological. This initial position of the bones, named reference, directly results from the segmentation of CT scans. First we compute all distances between the two surfaces and then we compute the Cumulative Distribution Function (CDF). We process this way for each iteration of the motion. Then we obtain a batch of CDF curves which provide us qualitative information relative to the motion such as potential collisions or dislocations. The graph of all CDF curves is called Figure of Articular Coherence (FoAC). A good articular coherence is characterised by CDF which are close to the reference. This qualitative method is coupled to a quantitative one named Index of Articular Coherence (IoAC) which computes the Haussdorff distance between the temporal distributions and the reference. This distance has to be as low as possible. The tools were tested on cadaveric experiments of ACL reconstruction provided by Hagemeister et al, (1999). They recorded the knee flexion/extension motion in following situations: the intact knee, after ACL resection, after three methods of ACL reconstruction on the same knee (‘over-the-top’ method (OTT), two different two tunnel reconstructions (2 tunnel). Our method was used, for the time being, for one specimen. We compare different post-surgery kinematics thanks to the FoAC and IoAC. Results and discussion. Functions were well correlated to the reference, when considering flexion motion of the intact knee. Regarding the results of the FoAC after ACL resection, we observed that the functions evolve in the direction of decreasing distances more rapidly, compared to the intact knee. This means that both articular surfaces are close to collision when ACL is resected. Regarding the results of the IoAC for the different experimental situations, we observe that the highest index is obtained for the ACL resected knee. The OTT method has equivalent results to the intact knee and for both 2 tunnels reconstructions, the index values are higher than those obtained with the intact knee. This higher index can be explained by an over-constraint on the knee movement, the knee appears to be more stable but it can possibly rigidify the joint as well. Through the use of the FoAC and IoAC, we reached the same conclusions of Hagemeister's work in a way that is more intuitive than by using kinematic curves and angle values. Our tools can describe the instantaneous state of the joint and are able to compare kinematics corresponding to different types ACL reconstructions

We performed 112 primary total knee replacements in patients under the age of 50, using a unique implant designed to pivot laterally during range of motion. This design more closely approximates the motion of an ACL deficient knee and controls for the anterior translation typical of more traditional designs. Patients were followed prospectively for a minimum of 3 years (range, 36 to 54 months) All patients were rated both clinically and radiographically using Knee Society Scores, SF-36 and standard radiographic instruments. Patients also completed a validated questionnaire that examined activity level, functional outcomes and ability to return to sports. Patients were compared to case matched historical controls that received a traditional, medially pivoting or flat on flat knee design. The senior author performed all procedures using a minimally invasive technique with preservation of the quad tendon and accomplished without lateral release. Inclusion criteria were patients under 50 with documented, tricompartmental osteoarthritis. All patients received the same posterior cruciate retaining, laterally pivoting knee prosthesis. Implanted with cement. All patients had resurfacing of the patella performed. The patients were compared to a case matched group of patients that received a modern medially pivoting knee replacement design. At last follow up, the mean Knee Society functional score was 94. There were no infections, fractures or other major complications in this group. Patients reported quicker recovery of quadriceps function, return to walking without assistance and quicker return to vigorous sports such as tennis. Functional outcomes were statistically improved over historical controls. There was no loss of radiographic alignment or increased signs of loosening compared with historical standards on the most recent radiographs. Total knee arthroplasty using a ACL substituting device was functionally superior to medially pivoting devices in this patient population. Patients reported better quadriceps dependent activities such as stair climbing and getting up from a chair. They were able to participate in more active sports without late signs of loosening or osteolysis. The authors can recommend this design in younger patients interested in vigorous activity, but full evaluation of this prosthesis will require longer-term results

Aim. The aim of this study is to outline the steps and techniques required to create a patient specific 3D printed guide for the accurate placement of the origin of the femoral tunnel for single bundle ACL reconstruction. Introduction. Placements of the femoral tunnels for ACL reconstruction have changed over the years 1,2. Most recently there has been a trend towards placing the tunnels in a more anatomic position. There has been subsequent debate as to where this anatomic position should be 3. The problem with any attempt at consensus over the placement of an anatomic landmark is that each patient has some variation in their positioning and therefore a fixed point for all has compromise for all, as it is an average 4. Our aim was to attempt to make a cost effective and quick custom guide that could allow placement of the center of the patients’ newly created femoral tunnel in the mid position of their contralateral native ACL femoral footprint. Materials & Methods. We took a standard protocol MRI scan of a patient's knee without ACL injury transferred the DICOM files to a personal computer running OsiriX (Pixmeo, Geneva, Switzerland.) and analyzed it for a series of specific anatomical landmarks (fig1). These measurements and points were then utilized to create a 3D computer aided design (CAD) model of a custom guide. This was done using the 3D CAD program 123Design (Autodesk Ltd., Farnbourgh, Hampshire). This 3D model was then uploaded to an online 3D printing service and the physical guide was created in transparent acrylic based photopolymer, PA220 plastic (fig 2) and 316L stainless steel. The models created were then measured using vernier calipers to confirm the accuracy of the final guides. The models produced were accurate with no statistical difference in size and positioning of the center of the ACL footprint from the original computer model and to the position of the ACL from the MRI scans. The costs for the models 3D printed were £3.50 for the PA220 plastic, £15 for the transparent photopolymer and £25 for the 316L stainless steel. The time taken from MRI to delivery for the physical models was 7 days. Conclusion. This study serves as the first step and a proof of concept for the accurate creation of patient specific 3D printed guides for the anatomical placement of the femoral tunnel for ACL reconstruction. The guides were easy to create and produce taking only a week and with a cost of between £3.50 and £25

Arthroscopic controlled retrograde drilling of femoral and tibial sockets and tunnels using a specially designed cannulated drill pin and retrocutter (Arthrex Inc, Naples FL.) provides greater flexibility for anatomical graft placement and in revision cases avoids previous tunnels and intra osseus hardware. Inside out drilling of femoral and tibial sockets minimises incisions and eliminates intra articular cortical bone fragmentation of tunnels rims common to conventional antegrade methods. This technique is also ideal for skeletally immature patients since drilling and graft fixation through growth plates may be avoided. Initial tunnel-referencing cannulated drill guide pin placement is carried out from outside-in. This technique (out-in/in-out) combines the advantages of the two-incision and the one-incision technique. In fact it permits us, as in the two-incision technique, to drill a pin guide from outside to inside in order to obtain the correct anatomical insertion of the ACL, otherwise not reproducible from inside-out. Since November 2004 our preferred technique for hamstring (autogenous quadrupled semitendinosis/ gracilis) ACL reconstruction incorporates the above mentioned femoral socket creation. In recent years, arthroscopically assisted ACL reconstruction has become the procedure of choice. Initially, arthroscopic techniques required two incisions for outside-in drilling of bone tunnels, but there has been a trend toward using a single incision with inside-out of the femoral tunnel. Those who advocate the two-incision technique state that they do so primarily because they believe that the two-incision procedures makes accurate femoral tunnel placement easier. Harner found no difference in tunnel placement using the two techniques, while Schiavone found that the inside-out femoral tunnels were significantly more vertical in the one-incision procedure. We have performed two-incision ACL reconstruction routinely since 1977, with very favourable results. The recent variation in our technique affords a reduction in morbidity, associated with improved cosmesis and quicker post-operative recovery. One factor related to our success appears to be a more anatomically positioned femoral tunnel, which in our hands, is difficult to accomplish with the single incision trans-tibial femoral socket creation. The retro-drill technique allows preparation of the correct anatomical femoral and tibial socket or tunnel, either with a very small lateral skin incision or without any skin incisions if the surgeon is using an allograft, and appears to represent a promising future technique in ACL reconstruction

Introduction: The anterior cruciate ligament (ACL) can be anatomically divided into two bundles: the anteromedial (AM) and the posterolateral (PL). These two bundles have unique contributions to load transfer across the knee joint. Material and Methods: We retrospectively reviewed the clinical results of a consecutive series of 25 patients who underwent partial ACL reconstruction. In 22 cases AM bundle reconstruction was performed, and in 3 patients isolated PL bundle reconstruction was performed. The 25 patients included 7 women and 18 men with an average age of 29.2 years at the time of surgery. Preoperative evaluation was conducted using manual Lachman test, pivot-shift tests, KT-1000, magnetic resonance imaging and passive stress radiographs of both knees. In all cases preoperative clinical evaluation was graded C as per the IKDC scoring system. The preoperative side-to-side anterior laxity measured by means of the KT-1000 was 5.8 mm in case of AM bundle rupture and 4.3 mm in case of PL bundle rupture. All the patients underwent single-bundle reconstruction of the ACL under arthroscopic assistance (one single incision technique). In case of AM bundle repair, the type of graft used was all autologous and included bone-patellar tendon-bone in 14 cases, 4-strand hamstring tendons in 5 cases and 2-strand hamstring tendons in 3 cases. In case of PL bundle repair, 2-strand hamstring tendons transplant was used in the 3 cases. Results: In all cases, postoperative clinical evaluation was graded A as per the IKDC knee examination scoring system. No abnormal sagittal laxity was found with the Lachman manual test. Postoperative IKDC knee subjective evaluation score averaged 81.3 % [58–95] at an average of 9 months follow-up. Postoperative side-to-side anterior laxity measured with KT-1000 averaged 0.46 mm in case of AM bundle rupture and 0.5 mm in case of PL bundle rupture. Postoperatively, all the patients had full extension of the knee. The flexion was the same as contra lateral knee in 92 % of the cases. We had no postoperative complication. Discussion: Diagnosis of partial ACL rupture is often difficult. If the AM bundle is torn, the Lachman manual test is soft and the pivot-shift test is more often equal or glide. If the Lachman manual test is intermediary between firm and soft and the pivot-shift test is clunk, PL rupture has probably occurred. The size of the graft was smaller than in one bundle procedures and was matched with the size of the bundle reconstucted. Peroperative technical difficulties were to preserve the healthy bundle and to drill the femoral tunnel in case of posterolateral bundle reconstruction. Conclusion: This study showed consistent postoperative results. If partial rupture of the ACL can be diagnosed, isolated AM or PL bundle reconstruction should be considered

Background The minimum size required for a successful quadrupled hamstring autograft ACL reconstruction remains controversial. The risks of ACL re-tear in younger patients who tend to participate in a higher level of sports activity, and female athletes who have numerous predisposing factors, are poorly defined. Purpose To identify risk factors for graft re-tears within 2 years of ACL surgery. The hypotheses are that female sex, a smaller size graft, and younger patients will increase the odds of failure. Study Design Cohort Study. Level of evidence, 3. A cohort of 503 athletes undergoing primary, autograft hamstring ACL reconstruction, performed by a single surgeon using the same surgical technique and rehabilitation protocol, between September-December 2012, was followed for a total duration of 2 years. Return to play was allowed between 6 and 12 months post-surgery upon completion of functional testing. Exclusion criteria included infections, revisions, double bundle techniques, multi-ligament injuries, non-compliance, BTB/allografts/hybrid grafts. Primary outcome consisted of binary data (ACL graft re-tear or no tear) as measured on physical exam (Lachman and pivot shift) and MRI. Multivariate logistic regression statistical analysis with model fitting was used to investigate the predictive value of sex, age, and graft size on ACL re-tear. Secondary sensitivity analyses were performed on the adolescent subgroup, age and graft size as categorical variables, and testing for interactions among variables. Sample size was calculated based on the rule of 10 events per independent variable for logistic regression. The mean age of the 503 athletes was 27.5 (SD 10.6; range = 12–61). There were 235 females (47%) and 268 males (53%) with a 6 % rate of re-tears (28 patients; 17 females). Mean graft size was 7.9 (SD 0.6; range = 6–10). Univariate analyses of graft size, sex, and age only in the model showed that younger age (odds ratio [OR] = 0.86; 95% confidence interval [CI] = 0.80–0.93; P = .001] and smaller graft size (OR = 0.36; 95% CI = 0.18–0.70; P = .003) were significantly predictive of re-tear. Female sex was correlated with re-tear but was not significant (OR = 1.8; 95% CI = 0.84–3.97; P = .13). Multivariate analysis with all 3 variables in the model showed similar significant results. Graft size < 8 mm (OR = 2.95; 95% CI = 1.33–6.53; P = .008) and age < 25 (OR = 7.01; 95% CI = 2.40–20.53; P = .001) were significantly predictive of re-tear. Entire model was statistically significant (Omnibus test P = .001; Hosmer-Lemeshow statistic P = .68; Receiver Operating Curve [ROC] = 0.8). Surgeons should counsel their patients who are female, younger than 25 and with a graft size less than 8 mm accordingly and consider modifying their surgical or rehabilitation techniques to mitigate these re-tear risks

Summary. Nearly one-third of patients in this series with an ACL rupture requiring reconstruction had evidence of MPFL injury. This should be considered when patients are seen, and when MRI scans are reviewed/reported. Introduction. The Medial Patello-Femoral Ligament (MPFL) is the largest component of the medial parapatellar ligamentous complex. The senior surgeon felt that there was an anecdotally high rate of MPFL injury amongst his patients undergoing Anterior Cruciate Ligament (ACL) repair, but no discussion of this in the present literature. Method. A literature search was performed; although there were both scanty radiographic and anatomical studies of the MPFL, we found no literature looking at ACL and MPFL concurrent injury rates. The Magnetic Resonance Imaging (MRI) scans of fifty consecutive ACL reconstruction patients were retrospectively reviewed. Two independent radiologists were asked to review the scans looking specifically for evidence of MPFL rupture or Injury. The degree of injury was rated as rupture or by degree of sprain as applicable. One patient was excluded due to motion artefact limiting certainty. Results. Of the remaining forty-nine patients, 35 (71%) were intact, but fourteen (29%) showed evidence of injury. Five (10%) had a low-grade sprain, six (12%) had high-grade sprain, and three (6%) had complete rupture. The radiologists also noted that there was some variation in scanning protocols, and those with fat suppressed scans had better diagnostic value; this offered an opportunity to change the scanning practice. Conclusion. Nearly one-third of patients in this series with an ACL rupture requiring reconstruction had evidence of MPFL injury. This should be considered when patients are seen, and when MRI scans are reviewed/reported. Further, we would suggest that fat suppression sequences are included as standard to improve imaging quality

Anterior cruciate ligament reconstruction has become a standard procedure with a documented good and excellent outcome of 70–90%. Important variables of outcome after surgery consist of objective and subjective variables. It is important to examine the relationship between commonly used knee rating systems and functional tests to assess whether there is a correlation between rating systems and functional performance. The purpose of this study was to determine if a correlation exists between four commonly used knee rating systems (Lysholm, Tegner, IKDC, Noyes) and commonly performed dunctional tests: single and timed hop, vertical jump and isometric, isokinetic and eccentric muscle strength.

44 consecutive patients (31 males and 13 females) were selected (mean age 27.9 years). All subjects were tested prior and 12 month following anterior cruciate ligament reconstruction. The subjects completed the above knee rating scores. The patients were then evaluated performing the following tests: single leg hop for distance, timed hop and vertical jump. Muscle strength was assessed using a Biodex dynamometer. Isometric strength was examined at 30 and 60 degrees of flex-ion. Isokinetic testing (concentric and eccentric) was performed at 120 and 180 degrees/sec. Their results of functional testing were expressed as percentage of the contralateral non involved limb.

A positive correlation was found between single leg hop, Lysholm (r=0.53, p< 0.05). IKDC (r=0.30, p< 00002) and Noyes score (r=0.45, p< 0.01). A positive correlation was found between vertical jump, Lysholm (r=0.21, p< 0002), IKDC (r=0.31, p< 0.0001) and Noyes score (r=0.31, p< 0.0001). There was no correlation between timed hop and knee scores. A negative correlation (r=0.25–0.46) was noted between eccentric peak extension torque at 120 degrees/sec and 180 degrees/sec (r=0.230.26). However it only reached significance (p< 0.04) between IKDC and eccentric torque at 120 degrees/sec and 180 degrees/sec (p< 0.01). In addition there was a moderate negative correlation (r=0.26, p< 0.0004)) between Lysholm score and eccentric peak torque at 180 degrees/sec. No correlations were found for isokinetic and isometric torque for the knee flexors.

Knee rating systems seem to reflect functional capabilities and subjective satisfaction of patients prior and post ACL reconstruction. Isokinetic strength does not seem to be an important predictor of knee function.

Purpose of the study: The tibial slope is an important parameter for knee surgery. Tibial slope designates the inclination of the tibial plateaus in the sagittal plane. The presence of a tibial slope and its value is intimately related to the condylotrochleal profile. The importance of tibial slope in knee disease and knee surgery is now universally recognised. Material and method: We reviewed 140 cases of anterior cruciate ligament (ACL) ligamentoplasty performed at the institute; 25 failures were identified. After analysis of the position of the tunnels, particularly the femoral tunnels, the most documented cause of failure, as well as other factors of failure, we measured the mean tibial slope in all operated patients. Results: Subjective Lachmann and the IKDC and ARPEGE scores associated with the dynamic study (TELOS) helped understand why knees can become unstable despite good surgical technique. Discussion: William and Lissner established a mathematical relations between tibial slope and stress forces applied to the ACL. Dejour and Bonnin demonstrated the effect of the tibial slope on anterior subluxation and single leg stance. The tibial slope should thus be considered for all knee procedures. Bonnin demonstrated that an excessive slope can be a factor of plasty failure

Introduction and purpose: Currently there is still discussion as to the best choice of graft for ACL (anterior cruciate ligament) reconstruction. The patellar tendon offers greater stability, but the technique using the attachments of tendons forming the pes anserinus has lower morbidity. We studied cases of surgery performed in our department 7 years ago using a four-strand semitendinosus and gracilis graft, analyzing results and complications. Materials and methods: We reviewed 130 patients that underwent surgery from 1999 to 2006. Plasty using the pes anserinus technique with a monotunnel was used on all of them, femoral stabilization was achieved with a transverse rigidfix system and tibial fixation with a resorbable intrafix system. Of the total, 39% had acute fractures and the rest chronic lesions more than 6 weeks old. Thirty menisectomies and 7 associated sutures were performed. In 21 patients diverse chondral lesions were found. Postoperatively a compressive bandage was used, hospital discharge was at 24–48 hours, early rehabilitation was used and no weight-bearing was allowed for 2 weeks, with complete weight-bearing allowed at 6 weeks. Results: Knee functionality and clinical symptoms were analyzed by means of the IKDC scale with good outcomes in 88% of cases and a mean joint balance of 132°; 12% of the cases had residual patellofemoral clinical signs, 4 patients had Cyclops syndrome, there were 2 plasty tears, 7 cases of lax plasties, 3 cases of joint infection, 1 case of deep vein thrombosis. Conclusions: Patients treated by four-strand grafting, according to a recent metaanalysis, have less symptoms and extension defects of the knee in comparison with patients treated with a patellar tendon graft. These are significant points to keep in mind in athletes. The improvement of stability in patellar tendon plasty is questionable in the majority of patients. Transverse fixation systems such as rigidfix avoid technical difficulties

Introduction: Recent data suggests that Double Bundle ACL reconstruction is bio-mechanically and potentially clinically superior. The success of Doudle bundle ACL reconstruction is dependent on tunnel placement. Of clinical concern is the increased technical difficulty and the potential for complications. The aim of our study was to determine how big the learning curve was for a high volume ACL Surgeon. Methods: Ten Double bundle ACL reconstruction procedures were carried out on suitable individuals. Following the procedure all patients underwent a CT scan of the relevant knee. Femoral tunnel placement was measured according to the quadrant technique described by Bernard and Hertel. The ideal tunnel locations used for analysis were those described by Zantop et al. On the tibial side, the radiographic measurements were performed according to Staubli and Rauschning. The centres of the AM and PL bundles were expressed as percentages of the maximum tibial sagittal diameter. The tibial ACL attachment at the centre of the AM bundle was taken to be 30% of the maximal tibial diameter and the centre of the PL bundle was located at 44%. The tunnel positions were measured for each patient. Results: Good tunnel placement was achieved in the majority of patients. There was an initial learning curve with improvement in tunnel placement as experience increased. Femoral tunnel positions had the greatest variation. There were no complications. The technical challenges are discussed. Conclusion: We have shown that it is possible for a high volume ACL surgeon to convert from a single bundle reconstruction technique to a double bundle reconstruction with relative accuracy

Purpose of the study: Reconstruction of the anterior cruciate ligament (ACL) controls laxity but does not enable restoration of strictly normal 3D kinematics. The purpose of this study was to compare the kinematics of the pathological knee with that of the healthy knee after ACL plasty. This study applied a new ambulatory system using miniature captors. Material and method: Five patients with an isolated injury of the ACL participated in this study. The patients were assessed after injury (T1), at five months (T2), and at 14 months (T3) after surgery. The assessment included laxity (KT-1000), the IKDC score and the Lysholm score. The 3D angles of the knees were measured when walking 30 m on flat ground using a system composed of to small inertia units (3D accelerometer and 3D gyroscope) and a portable recorder. Functional settings were optimised and validating to ensure easy precise measurement of the 3D angles. Symmetry of the two knees was quantified using a symmetry index (SI) (difference in amplitude normalised in relation to mean amplitude) and the correlation coefficient CC. Results: Clinical indicators improved during the follow-up (IKDC T1: 3C, 2C; T2: 5B; T3: 2A, 3B; subjective IKD: 53–95; Lysholm 67–96). Mean laxity improved from 8.6m to 2.5 mm. The gait analysis showed increased symmetry in terms of amplitude for flexion-extension (SI: −17% at T1, −1% at T2, 1% at T3), and an increase in symmetry in terms of the rotation signature (CC: 0.16 at T1, 0.99 at T2, 0.99 at T3). There was no trend to varus-valgus. Discussion: This study demonstrates the clinical application of the new ambulatory system for measuring 3D angles of the knee joint. Joint symmetry increased after ACL plasty but still showed some perturbation at 14 months. The results observed here are in agreement with the literature. Other patients and other types of gait are being analysed. Conclusion: This portable system allows gait analysis outside the laboratory, before and after ACL injury. It is very useful for follow-up after surgery

Introduction MRI accuracy in detecting knee lesions is a discussed controversy. Not always different knee lesions, diagnosed by MRI are confirmed by arthroscopy. The aim of this study is to correlate the accuracy of history, physical examination and MRI in evaluating meniscal and ACL lesions. Methods A prospective comparative study was performed to compare anamnestic and clinical data, MRI findings and arthroscopic findings to better understand the role of these methods and to assess if there are significative differences between various knee disorders. One hundred patients undergoing to arthroscopy for knee injuries were evaluated before surgery, registering anamnestic data, clinical examination and MRI findings. At the time of surgery every finding was registered and then compared with the previous acquired data. Results The most accurate data for diagnosis appears from history and clinical examination. The study showed a statistically significative differences between the RMI and arthroscopic findings. Differences between radiologist were detected in MRI data. Conclusion The results of such type of study, underlining the reliability and accuracy of patient’s history, clinical examination and MRI, comparing the different results among them and in various knee injuries. The accuracy of every test is the first step for an evidence based decision analysis process and represent a step forward an efficacious and economical pattern in diagnosis

Objectives: Advances in biomedical engineering have led to a thorough understanding of the body’s own capacity for ACL healing if provided the correct impetus—a long-term bioresorbable graft scaffold that anticipates the defect site’s biological and mechanical requirements. We hypothesize that by providing a structural scaffold which anticipates ACL repair mechanisms, “engineered” autologous ligament with excellent functional integrity can be developed by the body itself. This study evaluated the SeriACL™ graft, a non-mammalian derived long-term bioresorbable multi-bundled silk-based implant, for ACL replacement in a goat model at 3, 6 and 12 months post-operatively. Methods: The ACL of 43 goats was replaced with the SeriACL graft in an arthroscopically assisted procedure. The ACL was excised, a guide pin driven into the femur and 6mm diameter antegrade drilling performed. The tibial tunnel was drilled under direct visualization. The SeriACL, designed to mimic hamstring grafts, was anchored around a post on the femur. The graft was tensioned to 50N and cycled 30x before tibial fixation with a staple and sutures around a post. Animals were clinically, mechanically and histomorphometrically evaluated at 3, 6 and 12 months. Results: The SeriACL graft or surgical procedure did not induce early signs of acute inflammation, swelling or initial scar formation as indicated by rapidly declining scores for pain and knee size. All animals were weight bearing at 3, 6 and 12 months, with 95% returning to normal gait by 6 months. Lachmann showed the majority of knees were clinically stable at all points. Range of motion assessment indicated the knees maintained a normal range flexion and extension at all points. No gross cartilaginous damage, synovitis or particulate debris in lymph nodes was observed at any time point. Organized collagen and aligned fibroblasts in a crimp pattern were observed in the periphery of the ligament structure, adjacent to and attached to the remaining SeriACL device at all necropsy times. Collagen development throughout the graft and bone tunnels increased with time. Conversely, inflammation and device mass loss decreased with time. Fluoroscopy indicated no abnormal bone tunnel findings. Total plasma IgG levels did not increase from pre-surgery levels at any time. AP laxity indicated joint stability at all time points. Implant abrasion was observed to varying extents yet mechanical testing revealed tissue development supported increased load bearing over time. Conclusions: Results clearly demonstrate the potential of a scaffold-first strategy in engineering viable autologous ACL tissue that may serve over the patient’s life time. The SeriACL graft supported autologous development of a mechanically robust, biologically viable ligament which stabilized the joint over a 12 mo period. Mechanical, clinical and histological results indicated the safety of the SeriACL with initial indications of efficacy. Thus, the implant may offer the potential of an ACL replacement graft without the deleterious side-effects associated with donor-site morbidity and allogenic and xenogenic grafts

Purpose. The majority (73%) of orthopaedic surgeons in Canada prefer using semitendinosus-gracilis (STG) autograft for ACL reconstruction. However, there is large variation in tendon size between individuals which makes pre-operative estimation of graft size unpredictable. Inadequate graft size may require an alternative source of graft tissue that should be planned prior to surgery. The purpose of this study is to determine if clinical anthropometric data and MRI measurements of STG tendons can be used to predict hamstring graft size. Method. One-hundred and fourteen patients with ACL deficiency awaiting reconstruction using hamstring autograft were retrospectively evaluated. The following information was obtained from patient charts: height, weight, body mass index (BMI), age, and gender. Cross-sectional area (CSA) of gracilis (G) and semitendinosus (ST) tendons were determined from pre-operative MRI scans using NIH ImageJ analysis software. Actual STG graft diameters were obtained from operative reports. Correlations between patient height, weight, BMI, age, gender, ST-CSA, G-CSA, STG-CSA and intraoperative graft size were calculated to determine the association between these variables. Multiple stepwise regression was performed to assess the predictive value of these variables to intraoperative graft diameter. In addition, three investigators with no radiological experience made independent measurements of the ST and G tendons to determine the inter-rater reliability (ICC) of MRI measurements. Results. All variables were independently correlated with intraoperative graft size (p<0.001). However, based on multiple stepwise regression analysis, only models including STG-CSA (r2=.212; p<.001); STG-CSA and sex (r2=.285; p<.001); and STG-CSA, sex and weight (r2=.294; p<.001) were found to be significant predictors of graft size (when co-variation in other factors was controlled). Inter-class correlation coefficients demonstrated very high agreement between raters for measurements of the ST, G and STG (.816, .827, .863, respectively). Conclusion. Measurement of tendon CSA from MRI images is very reliable. A model including STG-CSA, sex and weight was found to be strongly predictive of hamstring graft diameter for ACL reconstruction. This model may enhance our ability to predict adequate graft size and identify instances that other graft tissues may be a better option. The results of this study may improve pre-operative planning for ACL reconstruction

Introduction: Rupture of the anterior cruciate ligament (ACL) is a serious injury associated with symptomatic instability of the knee. There is an increasing trend for confirmation of diagnosis with magnetic resonance imaging (MRI) before proceeding to reconstruction. The overall sensitivity and specificity of diagnosis using this modality is more than 95%. It is however observer-dependent. We have developed a simple 4 point recognition card to increase the pick-up rate of this injury for professionals without specific radiological training such as orthopaedic trainees. The aim of this study was to determine how much improvement could be achieved using this card and whether any change was sustained. Methods: 20 participants (orthopaedic trainees surgeons and medical students) were shown 20 MRI scans of the knee (10 with complete ACL ruptures and 10 with normal ACLs) and asked which scans were demonstrative of ACL pathology. Each participant was then randomly allocated to either having verbal teaching in the standard fashion about detection of ACL injuries [Group 1] or given written cards detailing a 4 point recognition plan for recognising ACL injuries on MRI [Group 2]. A repeat test of MRI scans was performed on each participant immediately after the teaching session and at 3 weeks. Results: The mean time taken to teach Group A was 14 mins and Group B was 11 mins (p < 0.05). The mean number of correct diagnoses was 2.7/10 in Group A and 3.1/10 in Group B pre-intervention (p > 0.05). Immediately following intervention, there were 6.1 correct diagnoses in Group A and 8.2 in Group B (p < 0.05). At 3 weeks, there were 3.4 correct diagnoses in Group A and 7.9 in Group B (p < 0.05). The difference in number of correct diagnoses at 3 weeks compared to immediately following intervention was significant in Group A (p < 0.05), but not in Group B (p > 0.05). Conclusions: The results support the use of the 4 point recognition card as to tool for increasing the pick-up of ACL injuries on MRI. It offers advantages over standard teaching Methods: since it takes less time to teach and the necessary information is retained to a greater degree than with traditional teaching methods

To determine the relationship between advancing months from ACL rupture and the incidence of intra-articular meniscal and chondral damage. From a prospectively collected database 5086 patients undergoing primary ACL reconstruction, using hamstring graft, carried out between January 2000 and August 2010 were identified. Data collected included the interval between injury and surgery, type and location of meniscal tears (requiring meniscectomy) and location and severity of chondral damage (ICRS grading system). Patients were grouped according to time interval and age. The median time from ACL injury to ACL reconstruction was 3 months (range 0.25 to 480). Overall, an increasing incidence of medial meniscal injury and chondral damage occurred with advancing chronicity of ACL deficiency. The incidence of medial meniscal injury requiring meniscectomy increased from 18% of patients undergoing ACL reconstruction within 4 months of injury to 59% of patients if ACL reconstruction was delayed more than 12 months (p<0.001). The incidence of lateral meniscal tears did not increase significantly over time. The increasing incidence of secondary pathology with advancing chronicity was more pronounced in the younger age groups. The risk of a medial meniscal tear requiring resection was significantly less if surgery was performed before 5 months in the <17 years group (Odds Ratio 2) and 17–30 years group (OR 1.9), but less so in the 31–50 years group (OR 1.5) and >50 years group (OR 1.5). Advancing age was associated with a greater incidence of chondral damage and medial meniscal injury, but not lateral meniscal injury. Males had a greater incidence of lateral meniscal tears (34% vs. 20%), but not medial (28% vs. 25%) or chondral damage (35% vs. 36%), compared to females. The incidence of chondral damage and medial meniscal tears increases with advancing time after ACL injury. Particularly in younger patients, ACL reconstruction should be performed within 4 months of ACL injury in order to minimise the risk of irreversible damage to meniscal and chondral structures

Objectives. This study aimed to investigate time-dependent gene expression of injured human anterior cruciate ligament (ACL), and to evaluate the histological changes of the ACL remnant in terms of cellular characterisation. Methods. Injured human ACL tissues were harvested from 105 patients undergoing primary ACL reconstruction and divided into four phases based on the period from injury to surgery. Phase I was < three weeks, phase II was three to eight weeks, phase III was eight to 20 weeks, and phase IV was ≥ 21 weeks. Gene expressions of these tissues were analysed in each phase by quantitative real-time polymerase chain reaction using selected markers (collagen types 1 and 3, biglycan, decorin, α-smooth muscle actin, IL-6, TGF-β1, MMP-1, MMP-2 and TIMP-1). Immunohistochemical staining was also performed using primary antibodies against CD68, CD55, Stat3 and phosphorylated-Stat3 (P-Stat3). . Results. Expression of IL-6 was mainly seen in phases I, II and III, collagen type 1 in phase II, MMP-1, 2 in phase III, and decorin, TGF-β1 and α-smooth muscle actin in phase IV. Histologically, degradation and scar formation were seen in the ACL remnant after phase III. The numbers of CD55 and P-Stat3 positive cells were elevated from phase II to phase III. . Conclusions. Elevated cell numbers including P-Stat3 positive cells were not related to collagens but to MMPs’ expressions

The purpose of this study is to investigate the incidence of patients with isolated bundle ACL tear (either isolated posterolateral or anteromedial bundle) during arthroscopy, and its correlation with physical exam. The relevant surgical technique to reconstruct the ligament is discussed. Between September 2006 and March 2009, patients with ACL injuries who received double- bundle ACL reconstruction were reviewed retrospectively. A specialist fellow performed a physical exam before and after anaesthesia. Intraop status of the ACL tear was assessed with correlation of the physical findings. Patients with isolated bundle tear would receive anatomical reconstruction of the torn bundle with preservation of the intact bundle. Double-bundle hamstrings reconstruction would be performed to those with complete tear. Medical notes of 159 patients were reviewed. There were 118 patients (74%) with complete ACL tear, 36 (23%) with isolated AM tear, and 5 (3%) with PL tear. For patients with complete ACL tear, 94% and 100% had positive Lachman, 50% and 87% had positive pivot shift, before and after anaesthesia. For patients with isolated AM tear, 100% had positive Lachman, 36% and 19% had positive pivot shift, before and after anaesthesia. For patients with isolated PL tear, 100% had positive Lachman, 20% and 80% had positive pivot shift, before and after anaesthesia. With better understanding of ACL, patients with isolated-bundle tear can preserve their intact bundle during reconstruction. However, in this study we find that physical exam correlates poorly with the arthroscopic findings. Further imaging (e.g. MRI) may be helpful to differentiate patients from isolated- bundle tear to complete tear

Introduction: Transient posterolateral subluxation of the lateral femoral condyle has been postulated as a non-contact mechanism of ACL rupture. The consistent location of MRI bone bruises on the anterior half of the lateral femoral condyle and the posterior rim of the lateral tibial plateau in ACL injuries suggest this mechanism of injury. Previous studies utilizing radiographs have investigated and eliminated the possibility of an increase in posterior tibial slope angle as a risk factor for ACL injury. None, however, have specifically measured the slope angle of the lateral tibial plateau. This study was designed to utilize MRI images for specific measurement of the lateral tibial slope angle and investigate this as a risk factor for ACL injuries. Materials & methods: The MRI images of 30 knees with complete ACL ruptures (Group I) and those of 30 knees with an intact ACL were studied. Both groups were age-matched (range 15 to 50 years) and predominantly male. The slope angles of the medial plateau and the lateral tibial plateau were measured separately. Statistical comparison was made between the slope angles of the medial and lateral tibial plateaus within both groups, and between the lateral tibial slope angles of Group I and Group II., using a Student’s t-Test. Results: The mean slope angle of the medial plateau was 3.43 degrees in Group I and 3.67 in Group II. The mean slope angle of the lateral tibial plateau was 6.40 degrees in Group I, and 5.43 in Group II. The difference between medial and lateral slope angles was statistically significant, as well as that between the lateral tibial slopes of Group I and Group II. There was no statistical difference between the mean slope angles of the medial plateau of both groups. Conclusion: There is a significant difference in slope angles of the medial and lateral tibial plateaus, and thus the need to specify the lateral tibial slope angle in determining slope angles as a risk for ACL injuries. While there is a statistically significant difference in lateral tibial slope angles of patients with ACL tears, the actual measured difference of one degree is not clinically useful as a predictor of ACL injury risk

Aims: The aims of this study were to evaluate the biomechanical properties and mode of failure of 4 methods of fixation used for hamstring tendon ACL grafts. The fixation methods investigated included titanium round headed cannulated interference (RCI) screws, bioabsorbable RCI screws, Endobuttons and Bollard fixation. It has been previously shown that a 2 strand tailored equine tendon-Soffix graft has equivalent biomechanical properties to a 4 strand human hamstring tendon-Soffix graft [. 1. ,. 2. ], therefore this model was used for the graft in the study. Materials and Method: 32 stifle joints were obtained from skeletally mature pigs, the soft tissues were removed and the ACL and PCL were sacrificed. Tibial tunnel preparation was standardised using the Mayday Rhino horn jig to accurately position a guide wire. An 8 mm cannulated reamer was then used over the guide wire to create the final tibial tunnel. A back radiusing device was then placed into the tibial tunnel to chamfer the posterior margin of the tunnel exit to prevent abrasion and fretting of the graft. A 2 strand equine tendon-Soffix graft was then introduced into the tibial tunnel and secured with one of the four fixation methods. The proximal part of the graft was attached to the cross head of the materials testing machine using the Soffix. Five of each method of fixation were tested mechanically to failure and three of each method were cyclically loaded for 1000 cycles between 5 to 150 N, followed by 2000 cycles at 50 to 450 N. Results: The mean ultimate tensile loads (UTL) were: titanium RCI screw = 444 N, bioabsorbable RCI screw = 668 N, Endobutton = 999 N and Bollard = 1153 N. The mode of failure for all RCI screws involved tendon slippage past the screw. Two Endobutton failures were encountered and one Bollard pull out occurred. Under cyclic loading conditions the titanium and bioabsorbable RCI screws failed rapidly after several hundred 5 to 150 N cycles due to tendon graft damage and progressive slippage. Both the Bollards and Endobuttons survived 1500 cycles at 50 to 450 N, with less tendon slippage occurring. Conclusion: Titanium and bioabsorbable RCI screws provide poor initial fixation of tendon grafts used for ACL reconstruction, having significantly lower UTL’s than both Endobutton and Bollard fixation. Under cyclic loading titanium and bioabsorbable RCI screws fail rapidly due to progressive tendon slippage, whereas Bollards and Endobuttons survive cyclic loading. Both Bollard fixation and Endobuttons provide sufficiently high UTL’s and survive cyclic loading to allow early postoperative mobilisation and rehabilitation. Caution must be used in the early postoperative period when using interference screws to secure a hamstring tendon graft because progressive tendon slippage may result in excessive graft elongation and early clinical failure

Aims

The aim of this study was to compare a bicruciate-retaining (BCR) total knee arthroplasty (TKA) with a posterior cruciate-retaining (CR) TKA design in terms of kinematics, measured using fluoroscopy and stability as micromotion using radiostereometric analysis (RSA).

Purpose: Free patellar tendon plasty is classically used for the treatment of chronic anterior instability of the knee. Good functional results may however be compromised by invalidating anterior pain. The purpose of this randomised trial was to obtain a prospective comparison of outcome after hamstring plasty or patellar tendon plasty. Material and methods: One hundred patients with an isolated tear of the anterior cruciate ligament were included in the study between May 1998 and 2001. Exclusion criteria were history of fracture, grade II laxity, and tear of the contralateral ACL. Patients were assigned to one of the treatment arms in random order in the operating room: Group A: arthroscopic free patellar tendon-bone graft; Group B: arthroscopic free four-strand hamstring graft. Two metal interference screws were used for fixation in all cases. The Aglietti method was used to calculate the position of the bore holes in all cases. The same rehabilitation protocol, in the same centre, was applied in all cases. The two groups were comparable for epidemiological, clinical, radiological, and instrumental laxity (KT1000®) data. IKDC criteria, activity level (sports), and instrumental measurement of laxity (KT1000® Medtronic) were used to assess outcome. Differences were considered significant for p < 0.05. Results: At mean follow-up (24 months, range 6 – 38) groups A and B were not significantly different for delay to resumed sports activity at the initial level, motion, clinical examination of ligaments, IKDC global score, and radiological evolution. At six months, 30% of the patients in group A complained of anterior pain; 20% of the patients still complained of pain at one year. In group B, femoropatellar pain or pain at the harvesting site was reported by 8% of the patients at six months and 4% at one year (p = 0.0005). These differences were no longer present at two years. The instrumental differential laxity was 0.66±1.1 mm in group A and 1±1.5 mm in group B (p =0.20). Two repeated trauma-induced tears were observed in group B. Conclusion: The preliminary results of this prospective randomised trial confirm the low morbidity of the harvesting site for hamstring grafts and the reliable stability of hamstring repair of isolated ACL laxity. A longer follow-up is however needed for long-term validation, particular concerning secondary distension of hamstring grafts as is frequently reported in the literature and which we have also observed in certain patients treated before this series

Anterior cruciate ligament (ACL) graft failure from rupture, attenuation, or malposition may cause recurrent subjective instability and objective laxity, and occurs in 3% to 22% of ACL reconstruction (ACLr) procedures. Revision ACLr is often indicated to restore knee stability, improve knee function, and facilitate return to cutting and pivoting activities. Prior to reconstruction, a thorough clinical and diagnostic evaluation is required to identify factors that may have predisposed an individual to recurrent ACL injury, appreciate concurrent intra-articular pathology, and select the optimal graft for revision reconstruction. Single-stage revision can be successful, although a staged approach may be used when optimal tunnel placement is not possible due to the position and/or widening of previous tunnels. Revision ACLr often involves concomitant procedures such as meniscal/chondral treatment, lateral extra-articular augmentation, and/or osteotomy. Although revision ACLr reliably restores knee stability and function, clinical outcomes and reoperation rates are worse than for primary ACLr.

Cite this article: Bone Joint J 2023;105-B(5):474–480.

Aims

The aim of this study was to report the pooled prevalence of post-traumatic osteoarthritis (PTOA) and examine whether the risk of developing PTOA after anterior cruciate ligament (ACL) injury has decreased in recent decades.

Aims

The purpose of this study is to determine an individual’s age-specific prevalence of total knee arthroplasty (TKA) after cruciate ligament surgery, and to identify clinical and genetic risk factors associated with undergoing TKA.

The anterior cruciate ligament (ACL) is frequently injured in elite athletes, with females up to eight times more likely to suffer an ACL tear than males. Biomechanical and hormonal factors have been thoroughly investigated; however, there remain unknown factors that need investigation. The mechanism of injury differs between males and females, and anatomical differences contribute significantly to the increased risk in females. Hormonal factors, both endogenous and exogenous, play a role in ACL laxity and may modify the risk of injury. However, data are still limited, and research involving oral contraceptives is potentially associated with methodological and ethical problems. Such characteristics can also influence the outcome after ACL reconstruction, with higher failure rates in females linked to a smaller diameter of the graft, especially in athletes aged < 21 years. The addition of a lateral extra-articular tenodesis can improve the outcomes after ACL reconstruction and reduce the risk of failure, and it should be routinely considered in young elite athletes. Sex-specific environmental differences can also contribute to the increased risk of injury, with more limited access to and availablility of advanced training facilities for female athletes. In addition, football kits are designed for male players, and increased attention should be focused on improving the quality of pitches, as female leagues usually play the day after male leagues. The kit, including boots, the length of studs, and the footballs themselves, should be tailored to the needs and body shapes of female athletes. Specific physiotherapy programmes and training protocols have yielded remarkable results in reducing the risk of injury, and these should be extended to school-age athletes. Finally, psychological factors should not be overlooked, with females’ greater fear of re-injury and lack of confidence in their knee compromising their return to sport after ACL injury. Both intrinsic and extrinsic factors should be recognized and addressed to optimize the training programmes which are designed to prevent injury, and improve our understanding of these injuries.

Cite this article: Bone Joint J 2023;105-B(10):1033–1037.

Introduction: The place of Anterior Cruciate Ligament (ACL) reconstruction in skeletally immature patients is now well established, but in reported series the numbers are few and the follow-ups short. Also, the majority of children are aged between 14 and 16 years and the results are as good as in adults. This report includes a number of ACL reconstructions in children aged less than 12 years.

Materials & Methods: A group of twenty patients with an average age of 13.5 years were reviewed. 7 children were aged 12 or under at the time of operation. There were 17 boys and 3 girls. The follow-up ranged from 12 to 72 months (mean 37.8 months).

Reconstruction was done by a standard 4-strand hamstring technique using an endobutton proximally and a spiked washer and screw distally in the tibia.

The IKDC, Lysholm and Tegner scores were used to assess the knees pre and post-operatively. Stability was measured using the KT-1000 arthrometer.

Results: Common modes of injury were football, rugby, skiing and squash. The left side was involved in 12 patients, and the right side in 8 patients. Interval between injury and surgery ranged from 3 to 22 months with an average of 8 months. Meniscal repair was carried out in 7 out of 12 patients. The average Tegner score before injury was 7.7, before operation was 4 and at the last follow-up was 7.6. The average pre-operative Lysholm score was 54.6 compared to the post-operative score of 93. There was no incidence of angular deformity or a limb length discrepancy. There has been 1 re-rupture in a child aged 11 years 11 months at operation but no meniscal injuries. The outcome in the 6 other children aged 12 or less at the time of operation has been as good as the older children.

Conclusion: Reconstruction of the anterior cruciate ligament using a trans-physeal technique gives good results in pre-pubertal children and in adolescents.

The Oxford unicompartmental knee replacement (UKR) is an established treatment option in the management of symptomatic end-stage medial compartmental osteoarthritis (MCOA), which works well in the young and active patient. However, previous studies have shown that it is reliable only in the presence of a functionally intact anterior cruciate ligament (ACL). This review reports the outcomes, at a mean of five years and a maximum of ten years, of 52 consecutive patients with a mean age of 51 years (36 to 57) who underwent staged or simultaneous ACL reconstruction and Oxford UKR. At the last follow-up (with one patient lost to follow-up), the mean Oxford knee score was 41 (. sd. 6.3; 17 to 48). Two patients required conversion to TKR: one for progression of lateral compartment osteoarthritis and one for infection. Implant survival at five years was 93% (95% CI 83 to 100). All but one patient reported being satisfied with the procedure. The outcome was not significantly influenced by age, gender, femoral or tibial tunnel placement, or whether the procedure was undertaken at one- or two-stages. In summary, ACL reconstruction and Oxford UKR gives good results in patients with end-stage MCOA secondary to ACL deficiency

Between 1993 and 1994, 891 patients underwent primary anterior cruciate ligament (ACL) reconstruction. A total of 48 patients had undergone bilateral ACL reconstruction and 42 were available for review. These patients were matched to a unilateral ACL reconstruction control group for gender, age, sport of primary injury, meniscal status and graft type. At 15-year follow-up a telephone interview with patients in both groups was performed. The incidence of further ACL injury was identified through structured questions and the two groups were compared for the variables of graft rupture or further ACL injury, family history of ACL injury, International Knee Documentation Committee (IKDC) subjective score and activity level. There were 28 male and 14 female patients with a mean age of 25 years (13 to 42) at the time of first ACL injury. Subsequent further ACL injury was identified in ten patients (24%) in the bilateral ACL reconstruction study group and in nine patients (21%) in the unilateral ACL reconstruction control group (p = 0.794). The mean time from bilateral ACL reconstruction to further ACL injury was 54 months (6 to 103). There was no significant difference between the bilateral ACL reconstruction study group and the matched unilateral ACL reconstruction control group in incidence of further ACL injury (p = 0.794), family history of ACL injury (p = 0.595), IKDC activity level (p = 0.514), or IKDC subjective score (p = 0.824). After bilateral ACL reconstruction the incidence of graft rupture and subjective outcomes were equivalent to that after unilateral ACL reconstructions. Cite this article: Bone Joint J 2013;95-B:798–802

This annotation considers the place of extra-articular reconstruction in the treatment of anterior cruciate ligament (ACL) deficiency. Extra-articular reconstruction has been employed over the last century to address ACL deficiency. However, the technique has not gained favour, primarily due to residual instability and the subsequent development of degenerative changes in the lateral compartment of the knee. Thus intra-articular reconstruction has become the technique of choice. However, intra-articular reconstruction does not restore normal knee kinematics. Some authors have recommended extra-articular reconstruction in conjunction with an intra-articular technique. . The anatomy and biomechanics of the anterolateral structures of the knee remain largely undetermined. Further studies to establish the structure and function of the anterolateral structures may lead to more anatomical extra-articular reconstruction techniques that supplement intra-articular reconstruction. This might reduce residual pivot shift after an intra-articular reconstruction and thus improve the post-operative kinematics of the knee.

Aims. To examine the rates of hamstring graft salvage with arthroscopic debridement of infected anterior cruciate ligament (ACL) reconstruction as reported in the literature and discuss functional outcomes. Materials and Methods. A search was performed without language restriction on PubMed, EMBASE, Ovid, CINAHL and Cochrane Register of Controlled Trials (CENTRAL) databases from their inception to April 2015. We identified 147 infected hamstring grafts across 16 included studies. Meta-analysis was performed using a random-effects model to estimate the overall graft salvage rate, incorporating two different definitions of graft salvage. Results. The graft salvage rate was 86% (95% confidence intervals (CI) 73% to 93%; heterogeneity: tau. 2. = 1.047, I. 2. = 40.51%, Q = 25.2, df = 15, p < 0.001), excluding ACL re-ruptures. Including re-ruptures as failures, the graft salvage rate was 85% (95% CI 76% to 91%; heterogeneity: tau. 2.  = 0.099, I. 2. = 8.15%, Q = 14.15, df = 13, p = 0.36). Conclusions. Arthroscopic debridement combined with antibiotic treatment can lead to successful eradication of infection and graft salvage, with satisfactory functional outcomes in many cases of septic arthritis following ACL reconstruction. Persistent infection despite repeat arthroscopic debridements requires graft removal with the intention of revision ACL surgery at a later stage. Take home message: Arthroscopic debridement combined with antibiotic therapy is an appropriate initial approach in most cases of septic arthritis following ACL reconstruction, achieving graft salvage rates of about 85%. Cite this article: Bone Joint J 2016;98-B:608–15

Objectives. We performed in vitro validation of a non-invasive skin-mounted system that could allow quantification of anteroposterior (AP) laxity in the outpatient setting. Methods. A total of 12 cadaveric lower limbs were tested with a commercial image-free navigation system using trackers secured by bone screws. We then tested a non-invasive fabric-strap system. The lower limb was secured at 10° intervals from 0° to 60° of knee flexion and 100 N of force was applied perpendicular to the tibia. Acceptable coefficient of repeatability (CR) and limits of agreement (LOA) of 3 mm were set based on diagnostic criteria for anterior cruciate ligament (ACL) insufficiency. Results. Reliability and precision within the individual invasive and non-invasive systems was acceptable throughout the range of flexion tested (intra-class correlation coefficient 0.88, CR 1.6 mm). Agreement between the two systems was acceptable measuring AP laxity between full extension and 40° knee flexion (LOA 2.9 mm). Beyond 40° of flexion, agreement between the systems was unacceptable (LOA > 3 mm). Conclusions. These results indicate that from full knee extension to 40° flexion, non-invasive navigation-based quantification of AP tibial translation is as accurate as the standard validated commercial system, particularly in the clinically and functionally important range of 20° to 30° knee flexion. This could be useful in diagnosis and post-operative evaluation of ACL pathology. Cite this article: Bone Joint Res 2013;2:233–7

Introduction: ACL injury is very common among sport activities. The incidence is very high and causes an important disorder in the articular function. Some articles have been published in the recent years about the risks to suffer this injury and its consequences in the biomechanics and proprioception of the limb. Although most of them were performed in animals and cadaver specimens and a few of them were realized in patients for a dynamic evaluation.

Purpose: The objective was to analyze in a longitudinal and prospective manner the changes in proprioception (muscular latency in the muscles span the knee in front of a stimulus load) occurred in the joint in 25 patients undergone an ACL injury before and after ACL reconstruction using the contra lateral knee as control.

Material and Methods: The study was performed in an experimental task pre and 4 and 6 months post surgery. Clinical Tegner, Lysholm, IKDC and SF12 evaluation, motion analysis system (EliteR) and surface electromyography was performed in a synchronized manner during a single leg jump before and after a fatigue exercise of a 10 seconds repetitive single leg jump. The muscles studied were anterior rectus, lateral and medial vastus, semitendinous and femoral biceps of both knees. Statistical analysis was performed and a P value < 0.05 was considered significant.

Results: Statistical significant larger latency times in each muscle but lateral vastus was observed in the affected knee in the preoperative period with improvement in the first period of 4 months postoperatively reaching measures of the normal contralateral knee without further improvement at the 6 month period. Vastus medialis was the muscle more affected before surgery and semitendinous, although improved, never reached a normal reactivity. Extensor muscles of the normal knee presented in all the periods of the study similar results but flexor muscles showed significant better propioceptive function in the 4th and 6th month post surgery. Improvement in latency time of muscle reactivity correlated with better scores in the Lysholm, IKDC and SF12 scores, although the SF12 mental status didn’t change.

Conclusion: Operated knees improve their neuromuscular activity relatively fast during the first 4th months. Therefore, specifically talking about neuromuscular function normal physical activity may be can be allowed at the 4th month and that means two months before usually normal activity level is permitted. Preoperative rehabilitation would have to insist to get better medialis vastus function. The mental status didn’t correlate with the neuromuscular status that means that psychologic aspects must be treated simultaneously with the physical training. Synergy among neurological pathways would exist, appreciating improved response in flexor muscles in the contralateral knee during the rehabilitation period

31 consecutive patients (mean 54.7 years) were examined mean follow-up time of 47 months. Patients were evaluated clinically; using Lysholm, Cincinnati, IKDC and Tegner Activities Scores. Objective assessments were made with KT1000 Arthrometer and Isokinetic strength testing.

Lysholm scores improved from 62 preoperatively to 93 at review; Cincinnati 48 to 89; Tegner 3.6 to 5.2. 81 percent of knees were considered normal or nearly normal to IKDC, 6 abnormal, none severely abnormal. KT1000 manual max difference 2.9mm; Isokinetic flexion strength 102 percent; extension strength 95 percent. Poor results were mainly associated with advanced articular cartilage degenerative changes at time of surgery. This also correlated with increased time from injury to surgery, and increased preoperative injury rates.

This study demonstrates that the anterior cruciate ligament can be reliably reconstructed in patients over the age of 50 years with good symptomatic relief, restoration of function and return to activity.

Introduction

Our primary hypothesis was simple: does gait on a downhill gradient distinguish between types of knee arthroplasty? Our secondary hypotheses were these: are stride length and other kinematic variables affected by cruciate ligament integrity following knee arthroplasty?

Aim: To determine the intra operative biomechanical properties of a semitendinosus graft used in ACL reconstruction.

Introduction: ACL reconstruction has become a commonly performed operation with 1,139 of these procedures being performed in South Australia in 1997 (SA Health Commission)

The majority of the scientific literature is based on data obtained from elderly cadaveric material. Little is known about the biomechanical properties of the soft tissue grafts currently used prior to implantation. The correct preconditioning and intraoperative tensioning of the soft tissue grafts has also not been investigated.

The initial graft biomechanical properties are important. Inadequate tension will lead to continuing instability whilst excessive tension may cause accelerated joint arthrosis. The tension in the graft may decrease by 30% if it has not been cyclically pretensioned.

Methods: A machine has been designed that will allow the intraoperative biomechanical testing of soft tissue grafts immediately prior to their implantation into the patient during ACL reconstruction. Data will be available on creep, stress relaxation, and tensile testing.

This device will also allow the accurate preconditioning of the graft, providing objective data that can then be compared to the subsequent clinical progress of the patient.

All testing will be accomplished during the time it takes to prepare the tunnels for insertion of the graft, and as such will not prolong unnecessarily the operative time.

Procedure: Once the graft has been prepared prior to fixation, it will be placed between two clamps. One is fixed to a load cell whilst the other is coupled to a linear actuator. The linear actuator will be driven by a computer controlled stepper motor under close-loop control. Custom software will cyclically load the autograft between two definable load points. A linear variable differential transformer (LVDT) will be used to monitor displacement of the autograft and load will be monitored with a load cell of capacity 125Kg.

This set-up will be immersed in a saline water bath maintained at body temperature during testing. The load cell will be hermetically sealed, with clamps and water bath being autoclavable. With the facilities for draping, the test area will remain sterile. The auto graft clamps will be designed to allow fixation of various graft materials (eg semitendinosus, gracilis, bone-patella tendon-bone) and adjustable for graft lengths. The water bath will house a thermocouple, heating mat and controller to maintain the saline temperature to within 1°C.

The testing system will be mounted on a stainless steel trolley for mobility in the operating room with an underlying shelf to house the associated electronics and a retractable side draw for storage of the laptop computer.

The autograft will be preconditioned between two known loads for 20 cycles recording load and displacement simultaneously on a laptop computer. Once preconditioned, the autograft will then be used for the ACL reconstruction in the standard way.

Summary: Objective data on preconditioning of ACL grafts, has never before been available intra-operatively. We outline the experimental set-up which has been designed and is undergoing testing prior to its use in a prospective study.

Aims

To identify unanswered questions about the prevention, diagnosis, treatment, and rehabilitation and delivery of care of first-time soft-tissue knee injuries (ligament injuries, patella dislocations, meniscal injuries, and articular cartilage) in children (aged 12 years and older) and adults.

Aims

The aim of this study was to compare the preinjury functional scores with the postinjury preoperative score and postoperative outcome scores following anterior cruciate ligament (ACL) reconstruction surgery (ACLR).

Purpose: To assess the results of ACL reconstructions carried out at our institution in a non-elite cohort of patients with regards to return to active sports post reconstruction.

Materials & Methods: Seventy-five (71%) of 106 patients who underwent reconstruction of isolated ACL tears between June 2001 and August 2004 performed by the senior author completed a newly designed questionnaire (incorporating Cincinnati Sports Activity Scale [CSAS]) to help us fully assess their return to sports and to elucidate reasons if not returning to pre-injury level. 55 were completed at follow up, with objective clinical assessment and other subjective questionnaires [KOOS, IKDC and Lysholm] and 20 were done through telephone interview.

Results: All 75 patients were involved in sports at CSAS Levels 1 & 2 prior to their injury and 39 (52%) had to drop to level 4 after injury. Following reconstruction 61 patients (81.3%) returned to CSAS 1 & 2 levels. 28 of 30 patients (93.3%) operated within 2 years from injury achieved pre-injury CSAS levels compared to 33 of 45 (73.3%) with a longer interval. The mean Lysholm, IKDC and KOOS Sports scores at 12 to 24 months follow up revealed a progressive trend and were 84.9, 76.3 and 73.6 respectively.

One reason for not returning to pre–injury intensity of sports was that many (71.7%) expressed fears of instability though most (70%) had no instability on playing. 77.8% of non-returners who were more than 30 years age reasoned not wanting to risk re-injury compared to 36.8% in the under 30 group. More significantly, 44.4% of over 30s said they were planning to drop their sporting level anyway compared to 5.5% in the younger group.

Conclusion: ACL reconstruction is best done as early as possible after injury for persons intending to return to competitive sports. The results are even better after early intervention in younger patients. Psychosocial issues play a significant role in return to active sports.

Purpose: This research project compared the accuracy of 3 methods of meniscal injury diagnosis that are commonly employed in a clinical orthopaedics: Clinical examination, MRI and Arthroscopic surgery.

Method: A retrospective review of charting was used to collect meniscal injury assessment data for 116 patients that had sustained an acute anterior cruciate ligament injury to one knee. Sixty-eight of the 116 patients had the presence of a meniscal lesion confirmed via surgery. Sensitivity and specificity of “hands on” clinical examination and MRI interpretation were determined using the results of arthroscopic surgery as the gold standard. Sensitivity and specificity of “hands on” clinical examination relative to MRI interpretation was also calculated. Finally, the findings of all three methods of meniscal evaluation were compared.

Results: Accuracy testing demonstrated that the sensitivity and specificity of clinical examinations (0.54 / 0.81) was comparable to levels observed for MRI (0.69 / 0.70), and when directly comparing the findings of clinical examination against MRI, that there was a high level of agreement when a meniscal lesion was not present (specificity: 0.91), but a much lower level of agreement when a meniscal lesion was suspected (sensitivity: 0.54). In general, when comparing the findings from clinical examination, MRI, and arthroscopic surgery, complete agreement among all 3 methods of evaluation occurred in only 51% of the patients.

Conclusion: Our results serve to highlight the inaccuracies associated with meniscal injury assessment when evaluating an acutely traumatized knee joint, and suggest that the incidence of secondary joint trauma following ligament injury may be under predicted.

Anterior Cruciate Ligament (ACL) reconstruction is performed widely across the United Kingdom by orthopaedic surgeons many of whom are members of the British Association for Surgery to the Knee (BASK), The choice of graft and fixation devices varies, based on surgeon’s preference, experience and patient needs. No data has been published with regards to choice of graft material or fixation devices in primary ACL reconstruction within the United Kingdom (UK).

To find out what current practice is, we undertook a postal questionnaire of BASK members. 62% responded. Of these, 55% of surgeons have been undertaking ACL reconstruction for more than 10 years. Only 39% are performing over 50 ACL reconstructions per year. 71% of surgeons have read the Good Practice for ACL reconstruction booklet published by the British Orthopaedic Association (BOA).

For the femur, the most popular devices used were metal screws (49%), rigidfix (17%), endobutton (14%), transfix (8%) and bioscrews (6%). For the tibia it was metal screws (57%), bioscrews (25%) and intrafix (14%)

16% use bone patellar tendon bone graft (BPTB), 18% use hamstrings, while 66% use either. Overall the most popular method seems to be the use of hamstrings or BPTB secured at both ends with metal interference screws without the use of a tensioner.

Whether the variation alters clinical result is difficult to prove. With no national registry, comparison of outcomes becomes impossible. Our survey should serve as a baseline for any future research in this area.

Introduction: Anterior Cruciate Ligament (ACL) is primary constrain to anterior displacement of tibia with respect to the femur and secondary to internal/external (IE) and varus/valgus (VV) rotations; an ACL reconstruction should thus control not only AP but also IE and VV laxities. For this reasons, more attention has given to residual rotational instability. This study aims to verify if those subjects with high of pre-op knee laxities has also high post-op laxity after an ACL reconstruction.

Material and Methods: The study includes 115 patients, that underwent ACL reconstructions between January 2005 and September 2007. Patients with associated severe ligaments tears or severe chondral defects were excluded. The joint passive kinematics was intra-operatively assessed using the BLU-IGS system (Orthokey, Delaware). We evaluated, before and after the reconstruction, the manual maximum IE rotation at 30° and 90° of flexion, VV rotation at 0° and 30° of flexion and AP displacement at 30° and 90° of flexion. We used the k-means algorithm applied to pre-op values to create two groups among the patients: the GROUP H, with higher pre-op laxity and the GROUP L, with lower pre-op laxity. The pre-op groups were compared for each test using independent Student’s t-test (p=0.01) in order to assess their difference. Student’s t-test (p=0.01) was performed on the corresponding post-op values in order to verify if the difference between H and L was maintained after the reconstruction.

Results: Mean pre-op VV at 0° was 7.1±0.9° for group H and 4.7±0.8° for group L (p< 0.01), post-op was 3.2±0.8° for group H and 2.5±0.8° for group L (p< 0.01). Mean pre-op VV at 30° was 6.2±1.5° for group H and 3.4±0.7° for group L (p< 0.01), post-op was 3.4±1.3° for group H and 2.2± 0.9° for group L (p< 0.01). Mean pre-op IE at 30° was 28.3±3.5° for group H and 19.2±3.1° for group L (p< 0.01), post-op was 21.5±3.8° for group H and 14.7±3.7° for group L (p< 0.01). Mean pre-op IE at 90° was 31.3±2.8° for group H and 22.4±3.5° for group L (p< 0.01), post-op was 22.3±4.0° for group H and 17.0±4.4° for group L (p< 0.01). Mean pre-op AP at 30° was 14.5±2.1mm for group H and 8.9±1.6mm for group L (p< 0.01), post-op was 6.2±1.6mm for group H and 4.2±1.6mm for group L (p< 0.01). Mean pre-op AP at 90° was 11.2±1.7mm for group H and 6.7±1.4mm for group L (p< 0.01), post-op was 5.4±1.8mm for group H and 3.4±1.3mm for group L (p< 0.01).

Discussion: The comparison between group H and group L showed that those patients with higher pre-op laxity had maintained higher post-op values mainly for all the tests. This finding is probably correlated to the possible presence of different tears affecting soft structures of the joint and to the proper and specific anatomy of each patient.

Purpose: Evaluate outcome after isolated intra-articular ACL graft in patients aged 40 to 60 years using patellar bone-tendon and gracilis grafts.

Material and methods: This retrospective comparative study included 30 consecutive patients who underwent arthroscopic surgery between September 1996 and September 1999 performed by the same operator: 14 patellar bone-tendon grafts and 16 gracilis grafts. The indication for surgery was knee instability in everyday or sports activities. Exclusion criteria were associated peripheral ligament plasty or bone procedures. The two populations were strictly identical except for gender and follow-up: patellar bone-tendon group: mean age 49 years, 12 men, follow-up 46 months, 6 associated menisectomies; gracilis series: mean age 48 years, 13 women, mean follow-up 30 months, 6 associated menisectomies. The IKDC score, laximetry (KT 2000), x-rays (AP, single stance lateral, 30° flexion) were used by two operators different from the operating surgeon to assess outcome.

Results: At last follow-up, there was a significant difference between functional and anatomic outcome in the two groups. 83% of the patients were classed IKDC A or B. Subjectively, 90% of the patients were satisfied or very satisfied. The pivot test was negative in 24 (80%), doubtful in 5 and positive in 1. 86% of the patients had a differential laxity less than 3 mm. In the gracilis group, two patients developed chronic hamstring pain. In the patellar bone-tendon group, two patients developed persistent patellar pain. Two patients underwent a second procedure for meniscectomy. At last follow-up the x-rays demonstrated early signs of degeneration in 20% of the patients and signs of medial femorotibial degeneration in 10%.

Discussion: Gracilis and patellar bone-tendon grafts provide strictly identical results; residual pain is not more prevalent after patellar graft; control of laxity is not less satisfactory after hamstring graft. In our series, ACL graft in patients over 40 years of age provided functional, laximet-ric, and radiographic results comparable to those in patients undergoing ACL grafts before the age of 40 years.

Conclusion: 1) ACL graft can be indicated after the age of 40 years for patients with knee instability bothersome for everyday or sports activities. 2) Functional and anatomic results are identical with those obtained in younger subjects. 3) Irrespective of the graft used, patellar or hamstring, outcome is satisfactory and morbidity is not different.

Introduction: The anterior cruciate ligament (ACL) is the most frequently damaged ligament in the knee joint. The patella tendon autograft is the current replacement of choice, however autografts are not always available and grafting often leads to donor site morbidity. Allogeneic implants may cause an adverse immunological reaction [1] The aim of this study was to develop an acellular tendon scaffold with the mechanical and biochemical properties of tissue which could be rapidly recellularised for use in tissue engineering of the anterior cruciate ligament.

Materials and Methods: Porcine patella tendons were dissected less than 24 hours after slaughter and washed in PBS. The tendons were decellularised using 0.1% (w/ v) SDS for 24 hours. Decellularisation was assessed by haematoxylin and eosin staining and light microscopy. The glycosaminoglycan and hydroxyproline (measure of collagen) content of the scaffold were also assessed quantitatively following decellularisation. Following decellularisation the scaffolds were subject to various levels of ultrasonication in order to modify the acellular scaffold prior to reseeding in an attempt to achieve recellularisation of the scaffold. Denaturation of the collagen within the scaffold following ultrasonication was assessed using the ƒÑ-chymotrypsin assay. Decellularised and ultrasonicated scaffolds were subject to uniaxial tensile loading to failure in a Howden tensile testing machine. The sonicated scaffolds were reseeded with human tenocytes (1x105 cells.cm2) and cultured in 5% CO2 in air at 37°C for three weeks. One scaffold was removed every seven days and either fixed in 10% neutral buffered formalin prior to dehydration and H& E staining or was stained with Live/Dead stain (Molecular Probes) and observed using confocal microscopy.

Results: Porcine patella tendons were successfully decellularised using 0.1% (w/v) SDS. Following decellularisation there was no change in the biochemical composition of the scaffold. Ultrasonication of the scaffold at 360W was shown to open up spaces between collagen bundles without damaging the collagen matrix and this was confirmed with the Ą-chymotrypsin assay. Following decellularisation and ultrasonication there was no change in the ultimate force (N) needed to break the tendon scaffold. When cells were seeded onto the sonicated scaffold, the cells were shown to penetrate to the centre of the scaffold within just 3 weeks of culture. Following staining with Live/Dead stain it was shown that after three weeks in static culture approximately 50% of the cells in the centre of the scaffold were viable. In comparison the cells cultured on the acellular non-sonicated scaffold remained on the surface of the scaffold and did not penetrate the matrix during this culture period.

Conclusion: An acellular scaffold with excellent biochemical and mechanical properties has been developed which can be recellularised in an important first step towards tissue engineering of the anterior cruciate ligament. Future work will investigate culture of the reseeded scaffold under appropriate physical stimulation with a view to maintaining tissue homeostasis and increasing cell viability.

Aims

There is limited information on outcomes of revision ACL reconstruction (rACLR) in soccer (association football) athletes, particularly on return to sport and the rate of additional knee surgery. The purpose of this study was to report return to soccer after rACLR, and to test the hypothesis that patient sex and graft choice are associated with return to play and the likelihood of future knee surgery in soccer players undergoing rACLR.

Purpose: To subjectively assess and present the outcome after ACL reconstruction with minimum follow-up of 24 months.

Methods: Our knee injury database was established in June 2001. Data were collected prospectively for all knee ligament reconstructions carried out by a single surgeon. The database has a prospectively studied consecutive series where all the patients surveyed completed the Lysholm, KOOS and IKDC 2000 questionnaires preoperatively and at 3, 6, 12 and 24 months postoperatively. Our knee injury database comprises of 163 patients who had ACL reconstruction in which Hamstrings were used in 120 cases and Bone Patella-Tendon Bone (BPTB) grafts in 43. This includes 27 complex reconstructions and 12 revisions (11 from other centres).

Results: Fifty-six of the 79 patients (70.8%) who were at least 2 years post ACL reconstruction attended for their 2 year review. Majority were male patients(90%) and both attendees and non- attendees were of a similar age (30.5 /30 respectively) and did not exhibit a statistically significant difference in their pre op or early post op scores. In the non-attendee group 2 were students, 1 emigrated, 1 registered as unemployed, 7 no employment status and 3 did not consent to such follow-up. The mechanism of injury was, 62 as sporting injury (24 contact/38 non-contact sport), 3 road traffic accidents and 8 activities of daily living and 2 not recorded. The mean scores were, IKDC – 77.14, Lysholm – 83.96 and KOOS symptom – 81.6.

Conclusions: All subjective evaluation questionnaires (KOOS, Lysholm and IKDC) revealed a progressive trend in our patients. We found that in the KOOS, a multidimensional patient completed aggregated score, the Quality of Life (QoL) dimension exhibited results which were interestingly not correlating with the other dimensions of the questionnaire, with patients who scored < 50% occupying manual or non-administrative positions at work

Introduction: The use of bioabsorbable devices in sports medicine surgery in the shoulder and knee continues to evolve as new designs, devices and materials become available. Concerns over potential problems associated with metal artifacts and permanent metal devices continue to motivate the development and use of polymeric based devices. Calaxo interference screws (Smith & Nephew Endoscopy, Andover, MA) are composed of a novel bioabsorbable material blend of poly DL- lactide – co – glycolide 85:15 (65%) and calcium carbonate (35%). These screws have been shown to be osteoconductive when placed in the centre of a 4 stranded tendon graft in an ovine ACL reconstruction [1]. The screws are fully resorbed at 26 weeks with new bone formation in the tunnel. In general, osteoconductive materials are often more effective when placed adjacent to a bony bed. This study investigated whether positioning the Calaxo screw adjacent to the bone tunnel was superior to screw placement within the tendon as in our previous study [1].

Materials and Methods: An intra-articular anterior cruciate ligament (ACL) reconstruction model using 2 doubled over tendon autografts whip stitched and inserted into the right hind limb of 8 sheep were used. Animals were culled at 26 or 52 weeks following surgery (n=4 per time point) and data was compared using the same surgical model but with screws placed in the center of the 4 stranded graft (Walsh et al., 2006). The tibias were CT scanned and processed for paraffin histology along the axis of the bone tunnel. Three dimensional models using the DICOM data obtained from the CT where made using MIMICS (Materialise, Belgium).

Result & Discussion: Results showed excellent biocompatibility of the screws with no adverse reactions at 26 and 52 weeks as in our previous study [1]. The screws were fully resorbed by 26 weeks with new bone replacing the PLC material. Similarly, the screws were not detectable at 52 weeks with new bone formation where the screw had previously resided. The intra-articular portion of the graft, articular cartilage and synovium was normal at 26 and 52 weeks as previously reported [1]. Tendon – bone healing proximal to the screw progressed in a normal fashion. No calcification of the intraarticular portion of the graft was noted. Computed tomography, 3D models and histology revealed an osteoconductive response to the PLC material with new bone formation as the material degraded in vivo.

Placement of the screw adjacent to the tendon graft and thus against the bone tunnel appears to provide superior results compared to screw placement in the middle of the graft sleeve device. This effect may be due to direct contact of the osteoconductive material to the adjacent bone bed.

[1] Walsh et al., Arthroscopy 2006, in press.

Aims

The success of anterior cruciate ligament reconstruction (ACLR) depends on osseointegration at the graft-tunnel interface and intra-articular ligamentization. Our aim was to conduct a systematic review of clinical and preclinical studies that evaluated biological augmentation of graft healing in ACLR.

Purpose: The purpose of this study was to: 1) assess outcome of ACL reconstruction with intra- and extra-articular hamstring plasty; 2) analyse the contribution of a synthetic lateral reinforcement by comparing two series.

Material and methods: This population of 100 patients was divided into two groups: group 1 with a synthetic lateral reinforcement (70 patients) and group 2 without lateral reinforcement (30 patients). Eighty-nine percent of the patients were reviewed. Mean age at operation was 28 years. Fifty-six percent of the patients were competition-level athletes (pivot sports) and lesions of the medial meniscus was observed peroperatively in 74% of the patients. Mean follow-up was 40 months. The two groups were comparable for all parameters studied except follow-up and age which were slightly lower in group 2 without reinforcement. ARPEGE and IKDC scores (with KT1000 at 89N) were established. We performed a precise analysis of residual laxity (TELOS at 15 kg). The position and the width of the bore holes were also analysed.

Results: According to the ARPEGE scores, outcome was excellent or very good in 71% of the patients and 87% were in IKDC classes A and B. Seventy percent of the patients who were competition-level athletes (pivot sports) resumed their activities at the same level. Residual differential laxity (TELOS) was 5.7 mm (mean). Tunnel width was 3.5 mm (mean). This work demonstrated the safety of hamstring harvesting.

Discussion Residual laxity was strongly correlated with clinical outcome: residual differential laxity less than 6 mm (threshold value) ensured a negative pivot test and 94% good results. We did not find any correlation between tunnel width and residual laxity. An overly anterior femoral position and medial meniscectomy significantly increased residual laxity. The femoral bore hole should be sufficiently posterior, 60 to 70% of the anteroposterior condylar width. Use of a synthetic reinforcement did not improve clinical or laximetric outcome in the reinforcement group; a natural plasty without synthetic reinforcement would be preferable.

Purpose: Functional, radiological and instrumental comparison between ACL reconstruction with Single Bundle plus lateral augmentation (SB) versus Double Bundle technique (DB).

Materials and methods: Random choice of 70 patients operated by the same equipe for ACL reconstruction with autologous hamstrings, 35 with SB+lateral augmentation and 35 with DB technique.

Investigation based on: Sport activity recover; IKDC; KT2000; isokinetical tests; muscular throphysm recover; Tegner and Lyshom score; Activity Rating Scale (ARS); Psychovitality Questionnaire; radio graphical evaluation in AP, LL and Rosemberg.

Results: IKDC results superior for DB group, with no bad results and superposable ROM for both groups. Sport activity recover in 100% patients of DB group, with reduced time respect to SB group. Excellent and superposable results for both groups at KT2000. Better muscular throphysm and isocinetic tests results for DB group. Ahlback score same to pre-op in both groups. ARS and Psychovitality questionnaire results better for DB group.

Discussion: Both surgical techniques guarantee excellent results.

DB technique allows a faster sport activity and muscular throphysm recover and better results in the isoci-netical tests.