Introduction: The Lachman test for anterior cruciate ligament (ACL) deficiency, requires a subjective assessment of joint movement, as the tibia is pulled anteriorly. This study has objectively quantified this movement using a magnetic tracking device. Materials and Methods: Ten patients aged 21 to 51 years were assessed as having unilateral ACL deficiency with conventional clinical tests. These patients were then reassessed using a magnetic tracking device (Polhemus Fastrak). Patients had magnetic sensors attached around the femoral and tibial mid-shafts using elasticated Velcro straps. The Lachman test was then performed with the patient lying within range of the system’s magnetic source. The test was performed three times on the normal and injured knees of each patient. During the tests, sensor position and orientation data was collected with an accuracy better than 1 mm and 1 degree, respectively. The data was sampled at 10Hz and stored on a computer for post-test analysis. This analysis deduced the tibial displacement resulting from each Lachman pull. Results: The main Lachman movement is an anterior displacement of the tibia with respect to the femur. The mean anterior movement for the normal knees was 5.6 mm (SD=2.5). By comparison the ACL deficient knees had a mean anterior movement of 10.2 mm (SD=4.2). This is 82 % more. A paired t test of this data showed it to be highly significant with P = 0.005. In addition to the anterior movement, there was also a small proximal tibial movement. In the normal knees the mean movement was 0.7 mm (SD=1.9). In the injured knees the mean movement was 2.1 mm (SD=3.4). However, this difference was not significant (P = 0.12). Conclusion: This study has quantified the movement produced during the Lachman test for ACL deficiency. The results compare well with reported results from similar arthrometer tests[. 1. ]. The main advantage of the magnetic tracker is that its lightweight sensors cause minimal disturbance to the established clinical test. It therefore offers a convenient and non-invasive method of investigation

Postoperative knee stability is critical in determining the success after reconstruction; however, only posterior and anterior stability is assessed. Therefore, this study investigates medial and lateral rotational knee laxity changes after partial and complete PCL tear and after PCL allograft reconstruction. The extending Lachman test assessed knee instability in six fresh-frozen human cadaveric knees. Tibia rotation was measured for the native knee, after partial PCLT (pPCLT), after full PCLT (fPCLT), and then after PCLR tensioned at 30° and 90°. In addition, tests were performed for the medial and lateral sides. The tibia was pulled with 130N using a digital force gauge. A compression load of 50N was applied to the joint on the universal testing machine (MTS Systems) to induce contact. Three-dimensional tibial rotation was measured using a motion capture system (Optotrak). On average, the tibia rotation increased by 33%-42% after partial PCL tear, and by 62%-75% after full PCL tear when compared to the intact case. After PCL reconstruction, the medial tibia rotation decreased by 33% and 37% compared to the fPCL tear in the case that the allograft was tensioned at 30° and 90° of flexion, respectively. Similarly, lateral tibial rotation decreased by 15% and 2% for allograft tensioned at 30° and 90° of flexion respectively, compared to the full tear. Rotational decreases were statistically significant (p<0.005) at the lateral pulling after tensioning the allograft at 90°. PCLR with the graft tensioned at 30° and 90° both reduced medial knee laxity after PCLT. These results suggest that while both tensioning angles restored medial knee stability, tensioning the Achilles graft at 30° of knee flexion was more effective in restoring lateral knee stability throughout the range of motion from full extension to 90° flexion, offering a closer biomechanical resemblance to native knee function

The primary purpose of this study was to assess whether patients presenting with clinical graft laxity following primary anatomic anterior cruciate ligament (ACL) reconstruction using hamstring autograft reported a significant difference in disease-specific quality-of-life (QOL) as measured by the ACL-QOL questionnaire. Clinical ACL graft laxity was assessed in a cohort of 1134/1436 (79%) of eligible patients using the Lachman and Pivot-shift tests pre-operatively and at 12- and 24-months following ACL reconstruction. Post-operative ACL laxity was assessed by an orthopaedic surgeon and a physical therapist who were blinded to each other's examination. If there was a discrepancy between the clinical examination findings from these two assessors, then a third impartial examiner assessed the patient to ensure a grading consensus was reached. Patients completed the ACL-QOL questionnaire pre-operatively, and 12- and 24-months post-operatively. Descriptive statistics were used to assess patient demographics, rate of post-operative ACL graft laxity, surgical failures, and ACL-QOL scores. A Spearman rho correlation coefficient was utilised to assess the relationships between ACL-QOL scores and the Lachman and Pivot-shift tests at 24-months post-operative. An independent t-test was used to determine if there were differences in the ACL-QOL scores of subjects who sustained a graft failure compared to the intact graft group. ACL-QOL scores and post-operative laxity were assessed using a one-way analysis of variance (ANOVA). There were 70 graft failures (6.17%) in the 1134 patients assessed at 24-months. A total of 226 patients (19.9%) demonstrated 24-months post-operative ACL graft laxity. An isolated positive Lachman test was assessed in 146 patients (12.9%), an isolated positive Pivot-shift test was apparent in 14 patients (1.2%), and combined positive Lachman and Pivot-shift tests were assessed in 66 patients (5.8%) at 24-months post-operative. There was a statistically significant relationship between 24-month post-operative graft laxity and ACL-QOL scores (p < 0.001). Specifically, there was a significant correlation between the ACL-QOL and the Lachman test (rho = −0.20, p < 0.001) as well as the Pivot-shift test (rho = −0.22, p < 0.001). There was no significant difference between the scores collected from the graft failure group prior to failure occurring (mean = 74.38, SD = 18.61), and the intact graft group (mean = 73.97, SD = 21.51). At 24-months post-operative, the one-way ANOVA demonstrated a statistically significant difference between the ACL-QOL scores of the no laxity group (mean = 79.1, SD = 16.9) and the combined positive Lachman and Pivot-shift group (mean = 68.5, SD = 22.9), (p = 0, mean difference = 10.6). Two-years post ACL reconstruction, 19.9% of patients presented with clinical graft laxity. Post-operative graft laxity was significantly correlated with lower ACL-QOL scores. The difference in ACL-QOL scores for patients with an isolated positive Lachman or Pivot-shift test did not meet the threshold of a clinically meaningful difference. Patients with clinical laxity on both the Lachman and Pivot-shift tests demonstrated the lowest patient-reported ACL-QOL scores, and these results exceeded the minimal clinically important difference

Aim To describe the presentation, clinical signs and arthroscopic features of isolated laxity of the PLC. Methods The records of 50 patients who had a reconstruction for isolated laxity of the PLC were reviewed. Any patient with injuries to the anterior cruciate, posterior crucicate or lateral collateral ligaments were excluded. ResultsHistory: • 21 patients could not remember an injury. • 12 patients had twisting/squatting injuries. • 17 patients had sporting injuries. Presenting Symptoms The commonest presenting symptoms were associated with overloading the anterior structures of the knee. These presenting symptoms tended to overshadow symptoms of instability which were quite subtle and usually only emerged on direct questioning or after painful lesions had been dealt with arthroscopically. Clinical Signs All patients had increased posterior translation of the tibia compared to the other side when the knee was examined in 20° of flexion using a modified Lachman test. Arthroscopic Features The lateral compartment opened easily in 38 (76%) and the posterior half of the lateral meniscus subluxed as far as the equator of the lateral femoral condyle in 32 (64%). Discussion When the knee is held in 20° of flexion, posterior translation of the tibia is prevented by the structures in the posterolateral corner. A modification of the Lachman test is described which easily demonstrates laxity of the PLC to both clinician and patient. Conclusion Laxity of the PLC is a common clinical finding, easily detected by a modification of the Lachman test. Patients may present without a history of injury, complaining of pain at the front of the knee and with subtle symptoms of instability. Laxity of the PLC should be considered in patients with recurrent or persistent symptoms following arthroscopy

Introduction. A common problem for patients receiving total knee arthroplasty (TKA) is postoperative functional impairment of the joint. This is minimized in bicruciate-retaining (ACL preserving) knee replacements, due to the important role of the anterior cruciate ligament (ACL) in normal kinematic patterns of the knee. We explore ACL sparing TKA by estimating the fraction of osteoarthritic TKA patients with a compatible ACL (assessed intraoperatively), while also examining potential preoperative indicators of ACL status. Method. We retrospectively examined 498 patients with a primary diagnosis of osteoarthritis who underwent a TKA by one surgeon between September 2013 and March 2015. Exclusion criteria included a prior TKA, a unicompartmental knee replacement, or inflammatory arthritis. Extensive preoperative data (within four months of surgery) for each patient was collected (anatomical alignment, extension, flexion, range of motion (ROM), Lachman test, and BMI) in addition to de-identified demographic data. The intraoperative assessment of ACL status (normal/functionally intact, compromised/deficient, or absent) was then obtained from our local database and compared with the preoperative data. IRB exemption was obtained to retrospectively collect data. Results. Intraoperative assessment of ACL status found 73.5% normal ACL, 12.9% compromised ACL, and 13.6% absent ACL. A significant demographic predictor of ACL status was gender (female - more likely intact, male - more likely absent; χ2 = 12.43, P<0.002). Patients with an intact ACL were also shown to have significantly better preoperative extension (χ2=14.83, P<0.022), flexion (F. 2, 469. = 9.93, P < 0.001), and ROM (F. 2, 469. = 9.38, P < 0.001) than those with a compromised ACL. We had a very small number of positive Lachman test results, and therefore could not draw any valid conclusion for preoperative predictive ability of the test. There was no significant difference in age, ethnicity, BMI or preoperative alignment between ACL status groups. Conclusion. Our study found 73.5% of 498 osteoarthritic TKA patients have an intact ACL. The strongest preoperative indicators of ACL status were gender, flexion, and ROM. Taken together, our results highlight a significant percentage of patients who are potential candidates for a bicruciate-retaining TKA

The knee joint displays a wide spectrum of laxity, from inherently tight to excessively lax even within the normal, uninjured population. The assessment of AP knee laxity in the clinical setting is performed by manual passive tests such as the Lachman test. Non-invasive assessment based on image free navigation has been clinically validated and used to quantify mechanical alignment and coronal knee laxity in early flexion. When used on cadavers the system demonstrated good AP laxity results with flexion up to 40°. This study aimed to validate the repeatability of the assessment of antero-posterior (AP) knee joint laxity using a non-invasive image free navigation system in normal, healthy subjects. Twenty-five healthy volunteers were recruited and examined in a single centre. AP translation was measured using a non-invasive navigation system (PhysioPilot) consisting of an infrared camera, externally mounted optical trackers and computer software. Each of the volunteers had both legs examined by a single examiner twice (two registrations). The Lachman test was performed through flexion in increments of 15°. Coefficients of Repeatability (CR) and Interclass Correlation Coefficients (ICC) were used to validate AP translation. The acceptable limits of agreement for this project were set at 3mm for antero-posterior tibial translation. The most reliable and repeatable AP translation assessments were at 30° and 45°, demonstrating good reliability (ICC 0.82, 0.82) and good repeatability (CR 2.5, 2.9). The AP translation assessment at 0°, 15°, 75° and 90° demonstrated moderate reliability (ICC ≤ 0.75), and poor repeatability (CR ≥3.0mm). The non-invasive system was able to reliably and consistently measure AP knee translation between 30° and 45° flexion, the clinically relevant range for this assessment. This system could therefore be used to quantify abnormal knee laxity and improve the assessment of knee instability and ligamentous injuries in a clinic setting

The aim of an anterior cruciate ligament (ACL) reconstruction is to regain functional stability of the knee following ACL injury, ideally allowing patients to return to their pre-injury level of activity. The purpose of this study was to assess clinical, functional and patient-reported outcomes following primary ACL reconstruction with hamstring autograft. A prospective case-series design (n=1610) was used to gather data on post-operative ACL graft laxity, functional testing performance and scores on the ACL quality of life (ACL-QOL) questionnaire. Demographic data were collected for all patients. Post-operative ACL laxity assessment using the Lachman and Pivot-shift tests was completed independently on each patient by a physiotherapist and an orthopaedic surgeon at the 6-, 12- and 24-months post-operative appointments. A battery of functional tests was also assessed including single leg Bosu balance, and 4 single-leg hop tests. The hop tests provided a comparative assessment of limb-to-limb function. Patients completed the ACL-QOL at all time points. The degree and frequency of post-operative laxity was calculated. A Spearman's rank correlation matrix was undertaken to assess for relationships between post-operative laxity, functional test performance, and the ACL-QOL scores. A linear regression model was used to assess for relationships between the ACL-QOL scores, as well as the functional testing results, and patient demographic factors. ACLR patients were 55% male, with a mean age of 29.7 years (SD=10.4), mean BMI of 25 (SD=3.9), and mean Beighton score of 3.3 (SD=2.5). At clinical assessment 2-years post-operatively, 20.6% of patients demonstrated a positive Lachman test and 7.7% of patients demonstrated a positive Pivot-shift test. The mean ACL-QOL score was 28.6/100 (SD=13.4) pre-operatively, 58.2/100 (SD=17.6) at 6-months, 71.8/100 (SD=18.1) at 12-months, and 77.4/100 (SD=19.2) at 24-months post-operative. Functional tests assessing operative to non-operative limb performance demonstrated that patients were continuing to improve up to the 24-month mark, with limb symmetry indices ranging from 96.6–103.1 for the single-leg hop tests. Spearman's correlation coefficient demonstrated a significant relationship between the presence of ACL graft laxity and ACL-QOL score at 12- and 24-months post-operative (p < 0 .05). Functional performance on the single leg balance and single-leg hop tests demonstrated significant correlations to the 6-, 12- and 24-month ACL-QOL scores (p < 0 .05). There was no statistically significant correlation between the functional testing results and the presence of ACL graft laxity. This study demonstrated that up to 20.6% of patients had clinically measurable graft laxity 2-years after ACLR. In this cohort, patients with graft laxity demonstrated lower ACL-QOL scores, but did not demonstrate lower functional testing performance. Patient-reported ACL-QOL scores improved significantly at each time point following ACLR, and functional performance continued to improve up to 2-years after surgery. The ACL-QOL score was strongly correlated to the patient's ability to perform single-limb functional tests, indicating that the ACL-QOL score accurately predicted level of function

Thirty-three knees in thirty-three patients who underwent ACLR using four-strand semitendinousus and gracilis tendon in our hospital were included in this study. In 17 knees, we use a fluoroscopic-based navigation system (Vector Vision ACL, BrainLab. Inc.) for positioning of the tunnels (Group 1). In the remaining 16 knees, positioning of the femoral and tibial tunnels was done without navigation (Group 2). In navigation operation, anteroposterior and lateral images of the knee were taken with a fluoroscope and captured into the computer. The optimal target points for bone tunnels were semi-automatically calculated and displayed on the screen. Femoral placement was determined based on the quadrant method. The target for tibial tunnel was set at 43% of tibial plateau AP length. Intraoperatively, positions of the drill guides were decided referring to both navigation image and arthroscopic image. We evaluated Lysholm score, International Knee Documentation Committee (IKDC) subjective score, Lachman test and pivot shift test at 1 year after operation and calculated bone tunnel position on the postoperative lateral x-ray films and expressed them as relative values against total AP length of the Blumensaat's line and of the tibia plateau. Lysholm score, IKDC subjective score, Lachman test and pivot shift test were not significantly differed between the groups. The femoral tunnels were 74.2±3.3% in Group 1 and 71.7±6.0% in Group 2 along and the tibial tunnels were 42.1±1.4% in group 1 and 43.0±4.6% in group 2 along the tibia plateau. Although femur and tibial tunnel positions were not significantly differed between the groups, variation of bone tunnel position was significantly smaller in Group 1, indicating a good reproducibility. One pin tract infection occurred in Group 1. This case successfully treated with debridment and antibiotics containing cement filling. Fluoroscopic navigation system is quite helpful for precise and reproducible creation of both femur and tibial tunnel. The results encourage us to use this system for double-bundle anatomical ACLR. However, a special care must be taken to avoid complication caused by tracker pin placement

Purpose: To compare the results of reconstruction of the anterior cruciate ligament (ACL) using autologous patellar bone-tendon-bone (BTB) graft with four semitendinous-medial rectus bundles (STMR). Our technique involved a double incision and attachment with an interference screw. Materials and methods: Non-randomised prospective study of 296 athletes operated on between 1988 and 2001: 202 BTB and 94 STMR. The mean ages were 22.8 and 21.6, males 52.9% and 58.5%, right knee involved in 54.46% and 54.3% of cases and mean follow-up of 13.7 and 12.4 months in the BTB and STMR groups, respectively. The evaluation of the results was based on the IKDC protocol and pre- and post-surgical anterior tibial displacement was evaluated with the radiological Lachman test and Telos® arthrometer. Results: The final IKDC evaluation was excellent or good in 86% and 89%, post-surgery Lachman tests showed less than 3 mm in 58.6 and 50.6%, from 4 to 8 mm in 33.3% and 31.6%, the athlete dropping sports activity in 9.3 and 3.4%, infection in 3 and 2 cases, stiffness in 2 and 2 cases and discomfort on kneeling in 8.7 and 2.2% of athletes in the BTB and STMR groups, respectively. Conclusions: We found no clinical differences between the two procedures. Anteroposterior stability was better in the BTB group. There was less discomfort on kneeling and fewer athletes dropped sports in the STMR group

Joint laxity assessments have been a valuable resource in order to understand the biomechanics and pathologies of the knee. Clinical laxity tests like the Lachman test, Pivot-shift test and Drawer test are, however, subjective of nature and will often only provide basic information of the joint. Stress radiography is another option for assessing knee laxity; however, this method is also limited in terms of quantifiability and one-dimensionality. This study proposes a novel non-invasive low-dose radiation method to accurately measure knee joint laxity in 3D. A method that combines a force controlled parallel manipulator device, a medical image and a biplanar x-ray system. As proof-of-concept, a cadaveric knee was CT scanned and subsequently mounted at 30 degrees of flexion in the device and placed inside a biplanar x-ray scanner. Biplanar x-rays were obtained for eleven static load cases. The preliminary results from this study display that the device is capable of measuring primary knee laxity kinematics similar to what have been reported in previous studies. Additionally, the results also display that the method is capable of capturing coupled motions like internal/external rotation when anteroposterior loads are applied. We have displayed that the presented method is capable of obtaining knee joint laxity in 3D. The method is combining concepts from robotic arthrometry and stress radiography into one unified solution that potentially enables unprecedented 3D joint laxity measurements non-invasively. The method potentially eliminates limitations present in previous methods and significantly reduces the radiation exposure of the patient compared to conventional stress radiography

Aims

A functional anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL) has been assumed to be required for patients undergoing unicompartmental knee arthroplasty (UKA). However, this assumption has not been thoroughly tested. Therefore, this study aimed to assess the biomechanical effects exerted by cruciate ligament-deficient knees with medial UKAs regarding different posterior tibial slopes.

Purpose: To assess if ACL reconstruction restores normal knee kinematics. Methods: Tibiofemoral motion was assessed weight-bearing through the arc of flexion from 0 to 90° in ten patients who were at least 6 months following successful hamstring graft ACL reconstruction. Lachman’s test was also performed using dynamic MRI. Mid-medial and mid-lateral images were analysed in all positions to assess the tibiofemoral relationship. Results: The laxity of the reconstructed knees was reduced to within normal limits. However the normal tibiofemoral relationship was not restored after ACL reconstruction with persistent anterior subluxation of the lateral tibial plateau throughout the arc of flexion 0–90°(p< 0.001). Conclusion: Successful ACL reconstruction reduces joint laxity and improves stability but it does not restore normal knee kinematics

The kinematic effect of tunnel orientation and position, during ACL reconstruction, has been only recently related to the control of rotational instability. This paper presents a detailed computer-assisted in vitro evaluation of two different femoral tunnel orientations with the same tunnel position, at 10.30 ‘o clock, during the intervention of ACL reconstruction with double bundle technique. Results highlighted better kinematic performances of the horizontal tunnel, with respect to the vertical one, in controlling antero-posterior (AP) laxities at 30°, and internal-external (IE) laxities. Elongations of anterior and posterior bundles of reconstructed ACL, for both reconstruction, decreased during PROM respectively by 20% and 40%. Total length of the graft varied during PROM, mainly due to graft elongation during tests, graft length on horizontal tunnel varied from 237 to 213mm while graft length on vertical tunnel varied from 257 to 233mm. Kinematic tests showed a better performance of horizontal tunnel in the control of IE rotations at 30° and 90° and of the Lachman test with respect to the vertical one. Stability was restored with both reconstructions

The choice of graft for anterior cruciate ligament reconstruction remains controversial. A systematic review was performed to compare bone-patella tendon-bone and 4-strand hamstring grafts. Medline (1966 onwards), EMBASE (1980 onwards) and the Cochrane database were searched retrieving 6312 possible articles but only 6 studies fulfilled all the inclusion criteria. To be included, the study had to be prospective, randomised or quasi-randomised, comparing 4SHS and central third BPTB autografts, inserted using an arthroscopically assisted technique and have a minimum 2-year follow up for all patients. These studies recruited 526 patients and 475 were followed for at least 2 years with 235 patients receiving a bone-patella tendon-bone graft and 240 receiving a 4-strand hamstring graft. Overall, there was a greater chance of extension loss (p=0.007) and a trend towards increased patellofemoral joint pain (p=0.09) with a patella tendon graft. With a 4-strand hamstring graft there is a greater loss of hamstring power (p=0.008) and a trend towards an increased chance of a pivot shift > 1 (p=0.12). There was no difference between the 2 groups in terms of lachman testing, chance of returning to the same level of sport, clinical knee scores, graft ruptures or other complications

Purpose of the study: This work examined the clinical, radiological, and videoarthroscopic features of partial tears of the anterior cruciate ligament (ACL) and analysed results of ligament plasties. Material and method: Mean age was 32 years. Patients complained of instability accidents in 70% of cases. The Lachman test was noted soft endpoint to + or ++ in 90%. A palpable click was found in 60% but was considered severe in two cases only. Telos laxity was moderate (about 5 mm) in 80%. Mean time to surgery was relatively short (9 months). Arthroscopic exploration revealed rupture of the anteromedial head of the ACL with preservation of the posterolateral component. There was a meniscal injury in nine knees. Early in our experience we performed a total plasty for nine patients (six using hamstring tendons and three with the patellar tendon). At the present time, we spare the posterolateral head and make a partial plasty of the anteromedial head (11 knees: 3 harvesting a single tendon [gracilis] and eight using the gracilis and the semitendious) associated with lateral reinforcement in five. Results: Mean follow-up was 30 months; 30% of patients had knee pain. Three knees exhibited a soft endpoint (+) all after a total plasty. There were no cases of quadriceps motion deficit or amyotrophy. Discussion: The existence of partial tears of the ACL were confirmed in this series. This type of tear corresponds to an objective condition seen arthroscopically and also to precise clinical presentations and biological findings: minor signs of instability with moderate objective anterior instability to the order of 5 mm. Conclusion: Considering this work and a review of the literature, the diagnosis of partial tears of the ACL could be established from the physical examination and measurements of anterior knee laxity. Reconstruction of a single head provides better results than complete reconstruction which would sacrifice an intact portion of the ACL

Background Female patients undergoing arthroscopic anterior cruciate ligament reconstruction with hamstring tendon graft developed increased post-operative laxity compared to male and female patients who had been reconstructed using patellar tendon graft. Hypothesis Supplementary tibial fixation in female patients will reduce laxity. Study Design Prospective, randomized, double-blinded clinical trial. Methods Fifty-six female patients divided into two groups (standard tibial fixation versus supplementary staple fixation) were followed for 2 years. Results After 2 years the mean side-to-side difference utilizing KT-1000 arthrometer manual maximum measurements was 1.8 mm (standard group) and 1.1 mm (staple group) (p=0.05). A Grade 0 Lachman test was present in 63% of the standard group and 86% of the staple group (p=0.04). Kneeling pain was experienced by 7% of the standard group and 29% of the staple group (p=0.05). Conclusions Supplementary tibial fixation in female patients undergoing ACL reconstruction with hamstring tendon graft and interference screw fixation with a single screw size significantly improves laxity measurements and clinical stability assessment 2 years postoperatively. However, this is at the cost of increased kneeling pain

The choice of graft for anterior cruciate ligament reconstruction remains controversial. A systematic review was performed to compare bone-patella tendon-bone and 4-strand hamstring grafts. Medline (1966 onwards), EMBASE (1980 onwards) and the Cochrane database were searched retrieving 6312 possible articles but only 6 studies fulfilled all the inclusion criteria. To be included, the study had to be prospective, randomised or quasirandomised, comparing 4SHS and central third BPTB autografts, inserted using an arthroscopically assisted technique and have a minimum 2-year follow up for all patients. These studies recruited 526 patients and 475 were followed for at least 2 years with 235 patients receiving a bone-patella tendon-bone graft and 240 receiving a 4-strand hamstring graft. Overall, there was a greater chance of extension loss (p=0.007) and a trend towards increased patellofemoral joint pain (p=0.09) with a patella tendon graft. With a 4-strand hamstring graft there is a greater loss of hamstring power (p=0.008) and a trend towards an increased chance of a pivot shift > 1 (p=0.12). There was no difference between the 2 groups in terms of lachman testing, chance of returning to the same level of sport, clinical knee scores, graft ruptures or other complications

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

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

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