Abstract. Introduction. All-tissue quadriceps tendon (QT) is becoming an increasingly popular alternative to hamstrings tendon (HT) and bone-tendon-bone (BTB) autograft for anterior cruciate ligament (ACL) reconstruction. The relatively short graft length however dictates that one, or both, ends rely on suture fixation. The strength of this construct is therefore extremely important. This study evaluates whether the use of a novel fixation technique can improve the tensile properties of the construct compared to a Krackow suture, and a looped tendon (suture free) gold standard. Methods. Eighteen porcine flexor tendons were tested, across three groups; suture-tape Krackow, looped tendon, and the novel ‘strain suture’. Biomechanical testing simulated the different stages of ACL graft preparation and loading (60N preload for 10 minutes, 10 cycles from 10N to 75N, and 1000 cycles from 100N to 400N). Elongation and load to failure were recorded, and stiffness calculated for each construct. Results. The mean elongation was significantly improved for the strain suture compared to the suture tape Krackow for preload, 10 cycle and 1000 cycle testing protocols respectively (1.36mm vs 4.93mm, p<001; 0.60mm vs 2.72mm, p<0.001; 2.95mm vs 29.08mm, p<0.001). Compared with the looped tendon, the strain suture demonstrated similar results for preload and 10 cycle elongation, but greater elongation during the 1000 cycle stage. Stiffness of the latter two constructs was similar. Conclusions. Augmentation of the suture fixation using this novel technique provides a construct that is significantly superior to currently practised suture techniques, and similar in elongation and stiffness to a looped graft

Abstract. Purpose. Since arthroscopic reconstruction of the anterior cruciate ligament (ACL) started, the use of peroneus longus grafts for primary ACL reconstruction (ACLR) was never thought of as there is very scant literature on it. So, our study aims to compare the functional outcome and complications in patients with ACL injury managed by ACLR with peroneus longus tendon (PLT) and hamstring tendons (HT) respectively. Materials and Methods. Patients with 16–50 years of either gender presenting with symptomatic ACL deficiency were admitted for arthroscopic single bundle ACLR and allocated into two groups (PLT and HT) operated and observed. Functional scores (IKDC and Lysholm score), clinical knee evaluation, donor site morbidity (AOFAS score) and thigh circumference were recorded preoperatively and at six months, one year post-operatively. The same post-op rehabilitation protocol was followed in both groups. Results. 194 patients (hamstring n=96, peroneus n=98) met the inclusion criteria. There were no significant differences between the pre-op, six months post-op and one-year postoperative score between the hamstring and peroneus longus groups in the IKDC (p=0.356) and Lysholm knee score (p=0.289). The mean for the AOFAS was 99.05±3.56 and 99.80±0.70 in the PLT and HT group respectively showing no statistical difference, with a significant improvement in thigh muscle wasting among the PLT group at final follow-up (p<0.001). Conclusion. We observed similar knee stability, functional outcome and no obvious donor site morbidity among both groups and recommend that a PL graft may be a safe, effective, and viable option for arthroscopic single bundle ACL reconstruction

Abstract. Purpose. This study aims to compare the clinical and functional outcomes and donor site morbidity of anterior cruciate ligament reconstruction with hamstring tendon autograft and peroneus longus tendon autograft in patients with complete anterior cruciate ligament rupture. Methods. Patients who underwent ACL reconstruction from February 2018 to July 2019 were randomly allocated into two groups (hamstring and peroneus longus). Functional scores (IKDC and Lysholm scores) and pain intensity by visual analogue score were recorded preoperatively, 3, 6months, 1, and 2 years postoperatively. Donor site morbidities were assessed with thigh circumference measurements in hamstring group and ankle scoring with the American foot and ankle score in peroneus longus group. Results. Sixty patients (hamstring n = 30, peroneus n = 30) met the inclusion criteria. The functional scores (IKDC and Lysholm) did not show statistical difference among the two groups at two years follow-up (P- value>0.05). The means values for visual analogue score after two years in the hamstring and Peroneus longus group was 1±0.74 and 1.03± 1.06, respectively. In peroneus longus group, the mean foot and ankle score was 98.63±3.88 (range= 85–100). A significant difference was found in the hamstring group between operated and non-operated thigh circumferences with p- value <0.001. Conclusions. Peroneus longus tendon autograft is an easily accessible tendon for ACL reconstruction and gives comparable functional outcomes as hamstring tendon with no additional donor site morbidity in our study

Objectives. The objective of this study was to determine if the use of fascia lata as a tendon regeneration guide (placed into the tendon canal following harvesting the semitendinosus tendon) would improve the incidence of tissue regeneration and prevent fatty degeneration of the semitendinosus muscle. Materials and Methods. Bilateral semitendinosus tendons were harvested from rabbits using a tendon stripper. On the inducing graft (IG) side, the tendon canal and semitendinosus tibial attachment site were connected by the fascia lata, which was harvested at the same width as the semitendinosus tendon. On the control side, no special procedures were performed. Two groups of six rabbits were killed at post-operative weeks 4 and 8, respectively. In addition, three healthy rabbits were killed to obtain normal tissue. We evaluated the incidence of tendon tissue regeneration, cross-sectional area of the regenerated tendon tissue and proportion of fatty tissue in the semitendinosus muscle. Results. At post-operative week 8, the distal end of the regenerated tissue reached the vicinity of the tibial insertion on the control side in two of six specimens. On the IG side, the regenerated tissue maintained continuity with the tibial insertion in all specimens. The cross-sectional area of the IG side was significantly greater than that of the control side. The proportion of fatty tissue in the semitendinosus muscle on the IG side was comparable with that of the control side, but was significantly greater than that of the normal muscle. Conclusions. Tendon tissue regenerated with the fascia lata graft was thicker than naturally occurring regenerated tissue. However, the proportion of fatty tissue in the semitendinosus muscle was greater than that of normal muscle. Cite this article: K. Tabuchi, T. Soejima, H. Murakami, K. Noguchi, N. Shiba, K. Nagata. Inducement of tissue regeneration of harvested hamstring tendons in a rabbit model. Bone Joint Res 2016;5:247–252. DOI: 10.1302/2046-3758.56.2000585

We reviewed the records of 107 consecutive patients who had undergone surgery for disruption of the knee extensor mechanism to test whether an association existed between rupture of the quadriceps tendon and the presence of a patellar spur. The available standard pre-operative lateral radiographs were examined to see if a patellar spur was an indicator for rupture of the quadriceps tendon in this group of patients. Of the 107 patients, 12 underwent repair of a ruptured patellar tendon, 59 had an open reduction and internal fixation of a patellar fracture and 36 repair of a ruptured quadriceps tendon. In the 88 available lateral radiographs, patellar spurs were present significantly more commonly (p < 0.0005) in patients operated on for rupture of the quadriceps tendon (79%) than in patients with rupture of the patellar tendon (27%) or fracture of the patella (15%). In patients presenting with failure of the extensor mechanism of the knee in the presence of a patellar spur, rupture of the quadriceps tendon should be considered as a possible diagnosis

Patella infera may occur after reconstruction of the anterior cruciate ligament (ACL), high tibial osteotomy and total knee replacement (TKR). Restriction of movement of the knee and pain may result. Our aim was to compare the incidence and to assess the effects of patella infera after TKR and unicompartmental knee replacement (UKR). We reviewed radiographs of the knees of 84 patients who had had either TKR or UKR as part of a randomised, controlled trial. The length of the patellar tendon was measured on serial radiographs taken before, at eight months and at five years after operation. There was no significant change in the length of the patellar tendon after UKR, but a significant reduction was observed after TKR. Five years after the operation, the shortening of the tendon had increased to a mean of 3.5 mm. Of the knees with TKR reviewed at five years, 34% developed patella infera, defined as 10% or more of shortening, compared with 5% of those with UKR. Shortening was greatest in those knees which had required a lateral release; in this subgroup the mean shortening was 7.2 mm. Shortening correlated with restriction of movement and pain in the knee. Our study has shown that patella infera develops in most patients after TKR with lateral release, and in approximately 25% of patients after TKR without this additional procedure. Patella infera rarely occurs after UKR. It is associated with restriction of movement and pain in the knee. It may be an effect of the more extensive exposure required to perform TKR and may, in part, explain the better clinical results of UKR

Two men, aged 21 and 50 years, were seen with ossification of the patellar tendon after injury to the knee in adolescence. They complained of pain and had patella alta. Large bony masses were excised from below the affected patellae. The patellar tendon was then reconstructed using a Leeds-Keio ligament. The results at six and ten years, respectively, were good, with neither patient having pain or an extension lag

The purpose of this study was to report the outcome of ‘isolated’ anterior cruciate ligament (ACL) ruptures treated with anatomical endoscopic reconstruction using hamstring tendon autograft at a mean of 15 years (14.25 to 16.9). A total of 100 consecutive men and 100 consecutive women with ‘isolated’ ACL rupture underwent four-strand hamstring tendon reconstruction with anteromedial portal femoral tunnel drilling and interference screw fixation by a single surgeon. Details were recorded pre-operatively and at one, two, seven and 15 years post-operatively. Outcomes included clinical examination, subjective and objective scoring systems, and radiological assessment. At 15 years only eight of 118 patients (7%) had moderate or severe osteo-arthritic changes (International Knee Documentation Committee Grades C and D), and 79 of 152 patients (52%) still performed very strenuous activities. Overall graft survival at 15 years was 83% (1.1% failure per year). Patients aged < 18 years at the time of surgery and patients with > 2 mm of laxity at one year had a threefold increase in the risk of suffering a rupture of the graft (p = 0.002 and p = 0.001, respectively). There was no increase in laxity of the graft over time. ACL reconstructive surgery in patients with an ‘isolated’ rupture using this technique shows good results 15 years post-operatively with respect to ligamentous stability, objective and subjective outcomes, and does not appear to cause osteoarthritis

A total of 30 patients who underwent endoscopic reconstruction of the anterior cruciate ligament using quadrupled hamstring tendons, through a single drill hole in the femur, had MRI 24 to 28 months after operation. In 18 patients the scans revealed that both the anterior and posterior portions of the graft ran in parallel from the inside of the femoral to the tibial tunnel. In 12, the posterior bundle had moved anteriorly and the anterior bundle could not be identified at the anterodistal border of the femoral tunnel. The mean difference in the anterior laxity, when compared with the contralateral knee, was 2.0 ± 1.7 mm and 4.3 ± 2.8 mm for the two types, respectively. Damage to the anterior bundle may occur when using the endoscopic technique because of biomechanical disadvantages, including concentration of loading and repetitive bending stress in the anterior bundle at the opening of the femoral tunnel

The aim of this study was to analyse the gait pattern, muscle force and functional outcome of patients who had undergone replacement of the proximal tibia for tumour and alloplastic reconstruction of the extensor mechanism using the patellar-loop technique.

Between February 1998 and December 2009, we carried out wide local excision of a primary sarcoma of the proximal tibia, proximal tibial replacement and reconstruction of the extensor mechanism using the patellar-loop technique in 18 patients. Of these, nine were available for evaluation after a mean of 11.6 years (0.5 to 21.6). The strength of the knee extensors was measured using an Isobex machine and gait analysis was undertaken in our gait assessment laboratory. Functional outcome was assessed using the American Knee Society (AKS) and Musculoskeletal Tumor Society (MSTS) scores.

The gait pattern of the patients differed in ground contact time, flexion heel strike, maximal flexion loading response and total sagittal plane excursion. The mean maximum active flexion was 91° (30° to 110°). The overall mean extensor lag was 1° (0° to 5°). The mean extensor muscle strength was 25.8% (8.3% to 90.3%) of that in the non-operated leg (p < 0.001). The mean functional scores were 68.7% (43.4% to 83.3%) (MSTS) and 71.1 (30 to 90) (AKS functional score).

In summary, the results show that reconstruction of the extensor mechanism using this technique gives good biomechanical and functional results. The patients’ gait pattern is close to normal, except for a somewhat stiff knee gait pattern. The strength of the extensor mechanism is reduced, but sufficient for walking.

Cite this article: Bone Joint J 2015;97-B:1063–9.

The use of platelet-rich plasma (PRP) as an adjuvant to tissue repair is gaining favour in orthopaedic surgery. Tunnel widening after anterior cruciate ligament (ACL) reconstruction is a recognised phenomenon that could compromise revision surgery. The purpose of this study was to determine whether PRP might prevent tunnel widening in ACL reconstruction.

Patients undergoing ACL reconstruction using a hamstring graft were randomly allocated either to have PRP introduced into the tunnels peri-operatively or not. CT scanning of the knees was carried out on the day after surgery and at three months post-operatively and the width of the tunnels was measured. Patients were also evaluated clinically at three months, when laxity was also measured.

Each group comprised 25 patients, and at three months post-operatively all were pain-free with stable knees, a negative Lachman test and a good range of movement. Arthrometric results had improved significantly in both groups (p < 0.001). Despite slightly less tunnel widening in the PRP group, there was no significant difference between the groups at the femoral opening or the mid-tunnel (p = 0.370 and p = 0.363, respectively) nor at the tibial opening or mid-tunnel (p = 0.333 and p = 0.177, respectively).

We conclude that PRP has no significant effect in preventing tunnel widening after ACL reconstruction.

Cite this article: Bone Joint J 2013;95-B:65–9.

Abstract. Methodology. Prospective single-surgeon case-series evaluating patients undergoing surgery by this technique. 76 cases (mean age of 33.2 years) who had primary ACL reconstruction with BTB or quadriceps tendon with bone block, were divided into 2 matched groups (age, sex and type of graft) of 38 each based on the method of femoral fixation used (interference screw or adjustable cortical suspension). Patients were followed up clinically and using PROMS from NLR with EQ-5D, KOOS, IKDC and Tegner scores. Complications and return to theatre were noted. Paired two-tailed student t-tests and Chi-square tests were employed for statistical analysis. Results. At a mean follow-up of 82 months, peri-operative mean EQ-5D VAS, EQ-5D Index, KOOS, IKDC and Tegner activity scores showed significant improvement (p<0.05), but no significant difference between the two groups (p>0.05). Mean graft length and diameter was 77mm and 9.3 respectively. Mean interval from injury to surgery was 10.5 months. 18(23.7%) patients had associated meniscal tear with 73.3 % undergoing repair. 10 cases (13.2 %) returned to theatre including, MUA for arthrofibrosis (n=2) and intra-substance graft failure (n=2). 3 cases had to be converted to interference screw fixation due to the tightrope cutting through from the femoral bone block as a result of a technical pitfall. Conclusion. Primary ACL reconstruction using adjustable cortical suspension on femoral side for BTB or quadriceps bone-block tendon graft is a safe technique with added advantages of 360 degree bone ingrowth and no screw in the femoral tunnel

Abstract. Introduction. Derby technique for posterolateral corner (PLC) reconstruction uses a doubled gracilis autograft to reconstruct the popliteo-fibular ligament (PFL) and a split biceps tendon transfer to reconstruct the lateral collateral ligament (LCL). We report midterm outcomes of a case series who underwent PLC reconstruction. Methodology. A retrospective review of 27 patients who underwent PLC reconstruction from 2012 until 2018 was performed (6 females, 21 males, median age 26). Median time interval from injury to primary procedure was 10 months. Outcomes were recorded as per clinical assessment and outcome scores. Results. All patients had no varus laxity in full knee extension. Similarly, at 30° of knee flexion, 25 patients (92.5%) had no varus laxity and 2 patients (7.5%) had grade 1 laxity. No patients demonstrated abnormal external rotation at final follow up. Outcome scores were obtained from 17 patients who underwent primary ligament reconstruction at a mean follow up of 72 months postoperatively. The mean Lysholm score was 94 +/-5.5 (72–100) and mean subjective IKDC score was 78/87 (89.6%) (51–87). 90% of our patients had gained normal or nearly normal IKDC scores on returning to routine activities of daily living and sports following surgery compared to their pre-injury status. Conclusion. Our technique enables an anatomical LCL & PFL reconstruction in isolation or in combination with ACL/PCL reconstruction or to augment an acute repair without contralateral graft harvest or allograft. The functional knee scores demonstrated in this cohort are comparable and in fact superior to previously published knee scores after PLC reconstruction

Abstract. Patellofemoral Arthroplasty (PFA) is an alternative to TKA for patellofemoral osteoarthritis that preserves tibiofemoral compartments. It is unknown how implant positioning affects biomechanics, especially regarding the patella. This study analysed biomechanical effects of femoral and patellar component position, hypothesising femoral positioning is more important. Nine cadaveric knees were studied using a repeated-measures protocol. Knees were tested intact, then after PFA implanted in various positions: neutral (as-planned), patellar over/understuffing (±2mm), patellar tilt, patellar flexion, femoral rotation, and femoral tilt (all ±6°). Arthroplasties were implemented with CT-designed patient-specific instrumentation. Anterior femoral cuts referenced Whiteside's line and all femoral positions ensured smooth condyle-to-component transition. Knee extension moments, medial patellofemoral ligament (MPFL) length-change, and tibiofemoral and patellofemoral kinematics were measured under physiological muscle loading. Data were analysed with one-dimensional statistical parametric mapping (Bonferroni-Holm corrected). PFA changed knee function, altering extension moments (p<0.001) and patellofemoral kinematics (p<0.05), but not tibiofemoral kinematics. Patellar component positioning affected patellofemoral kinematics: over/understuffing influenced patellar anterior translation and the patellar tendon moment arm (p<0.001). Medially tilted patellar cuts produced lateral patellar tilt (p<0.001) and vice versa. A similar inverse effect occurred with extended/flexed patellar cuts, causing patellar flexion and extension (p<0.001), respectively. Of all variants, only extending the patellar cut produced near-native extension moments throughout. Conversely, the only femoral effect was MPFL length change between medially/laterally rotated components. PFA can restore native knee biomechanics. Provided anterior femoral cuts are controlled and smooth condyle-to-component transition assured, patellar position affects biomechanics more than femoral, contradicting the hypothesis

Abstract. Introduction. OtisMed Shape Match ® patient specific implant cutting jigs were designed to place TKA in kinematic alignment (KA) rather than traditional mechanical alignment (MA). This product was withdrawn from the market in 2013. It has been hypothesised that KA might lead to early implant failure. Initial evidence has not supported this. We present 10 year outcome data for the largest single centre cohort to date. Methodology. Between 2010 and 2013, 127 Shape Match® TKAs were implanted in 119 individuals. Retrospective review of long leg post-operative radiographs assessed femoral mechanical anatomical angle (FMA), tibial mechanical angle (TMA), hip-knee-ankle angle (HKA), posterior tibial slope (PTS) and femoral component flexion. Oxford Knee Scores (OKS), revision and further surgery rates were reviewed. Results. 4 (3.1%) patients underwent revision for instability, recurrent haemarthrosis, stiffness and infection respectively. In this subgroup, PTS ranged from 9–25° (SD 7.5°). PTS range for non-revision subgroup was 1–23° (SD 4.6). 1 patient with a PTS of 21° had failure of quadriceps tendon, but was not revised. Mean OKS at 1year = 38.1 (SD 1.08), 2 years = 39.3 (SD 1.08), 5 years = 40.8 (SD 4.11). PTS had the largest impact on OKS, with <10° slope conferring a higher OKS. Conclusions. At 10 year follow up, this cohort did identify several cases where excessive PTS was evident. This may have led to revision surgery and contributed post-operative complications. PTS, unlike other alignment measures, impacted OKS results. Overall revision rate and OKS were consistent with registry and other published data

Aims. Inadvertent soft tissue damage caused by the oscillating saw during total knee arthroplasty (TKA) occurs when the sawblade passes beyond the bony boundaries into the soft tissue. The primary objective of this study is to assess the risk of inadvertent soft tissue damage during jig-based TKA by evaluating the excursion of the oscillating saw past the bony boundaries. The second objective is the investigation of the relation between this excursion and the surgeon’s experience level. Methods. A conventional jig-based TKA procedure with medial parapatellar approach was performed on 12 cadaveric knees by three experienced surgeons and three residents. During the proximal tibial resection, the motion of the oscillating saw with respect to the tibia was recorded. The distance of the outer point of this cutting portion to the edge of the bone was defined as the excursion of the oscillating saw. The excursion of the sawblade was evaluated in six zones containing the following structures: medial collateral ligament (MCL), posteromedial corner (PMC), iliotibial band (ITB), lateral collateral ligament (LCL), popliteus tendon (PopT), and neurovascular bundle (NVB). Results. The mean 75. th. percentile value of the excursion of all cases was mean 2.8 mm (SD 2.9) for the MCL zone, mean 4.8 mm (SD 5.9) for the PMC zone, mean 3.4 mm (SD 2.0) for the ITB zone, mean 6.3 mm (SD 4.8) for the LCL zone, mean 4.9 mm (SD 5.7) for the PopT zone, and mean 6.1 mm (SD 3.9) for the NVB zone. Experienced surgeons had a significantly lower excursion than residents. Conclusion. This study showed that the oscillating saw significantly passes the edge of the bone during the tibial resection in TKA, even in experienced hands. While reported neurovascular complications in TKA are rare, direct injury to the capsule and stabilizing structures around the knee is a consequence of the use of a hand-held oscillating saw when making the tibial cut. Cite this article: Bone Joint J 2020;102-B(10):1324–1330

Objectives. Posterior condylar offset (PCO) and posterior tibial slope (PTS) are critical factors in total knee arthroplasty (TKA). A computational simulation was performed to evaluate the biomechanical effect of PCO and PTS on cruciate retaining TKA. Methods. We generated a subject-specific computational model followed by the development of ± 1 mm, ± 2 mm and ± 3 mm PCO models in the posterior direction, and -3°, 0°, 3° and 6° PTS models with each of the PCO models. Using a validated finite element (FE) model, we investigated the influence of the changes in PCO and PTS on the contact stress in the patellar button and the forces on the posterior cruciate ligament (PCL), patellar tendon and quadriceps muscles under the deep knee-bend loading conditions. Results. Contact stress on the patellar button increased and decreased as PCO translated to the anterior and posterior directions, respectively. In addition, contact stress on the patellar button decreased as PTS increased. These trends were consistent in the FE models with altered PCO. Higher quadriceps muscle and patellar tendon force are required as PCO translated in the anterior direction with an equivalent flexion angle. However, as PTS increased, quadriceps muscle and patellar tendon force reduced in each PCO condition. The forces exerted on the PCL increased as PCO translated to the posterior direction and decreased as PTS increased. Conclusion. The change in PCO alternatively provided positive and negative biomechanical effects, but it led to a reduction in a negative biomechanical effect as PTS increased. Cite this article: K-T. Kang, Y-G. Koh, J. Son, O-R. Kwon, J-S. Lee, S. K. Kwon. A computational simulation study to determine the biomechanical influence of posterior condylar offset and tibial slope in cruciate retaining total knee arthroplasty. Bone Joint Res 2018;7:69–78. DOI: 10.1302/2046-3758.71.BJR-2017-0143.R1

Aims

As has been shown in larger animal models, knee immobilization can lead to arthrofibrotic phenotypes. Our study included 168 C57BL/6J female mice, with 24 serving as controls, and 144 undergoing a knee procedure to induce a contracture without osteoarthritis (OA).

Aims

In cases of severe periprosthetic joint infection (PJI) of the knee, salvage procedures such as knee arthrodesis (KA) or above-knee amputation (AKA) must be considered. As both treatments result in limitations in quality of life (QoL), we aimed to compare outcomes and factors influencing complication rates, mortality, and mobility.

Aims

Knowledge on total knee arthroplasties (TKAs) in patients with a history of poliomyelitis is limited. This study compared implant survivorship and clinical outcomes among affected and unaffected limbs in patients with sequelae of poliomyelitis undergoing TKAs.