Aims. The aim of this prospective study was to assess the long-term clinical, radiological, functional, and quality of life (QoL)-related outcome of patients treated with the synthetic Ligament Advanced Reinforcement System (LARS) device for anterior cruciate ligament (ACL) rupture. Methods. A total of 41 patients who underwent ACL reconstruction with the LARS device (mean age 39.8 years (SD 12.1 ); 32% females (n = 13)) were prospectively included between August 2001 and March 2005. MRI scans and radiographs were performed at a median follow-up of 2.0 years (interquartile range (IQR) 1.3 to 3.0; n = 40) and 12.8 years (IQR 12.1 to 13.8; n = 22). Functional and QoL-related outcome was assessed in 29 patients at a median follow-up of 12.8 years (IQR 12.0 to 14.0) and clinically reconfirmed at latest median follow-up of 16.5 years (IQR 15.5 to 17.9). International Knee Documentation Committee (IKDC) and Tegner scores were obtained pre- and postoperatively, and Lysholm score postoperatively only. At latest follow-up, range of motion, knee stability tests, 36-Item Short Form Health Survey (SF-36), and IKDC scores were ascertained. Complications and reoperations during follow-up were documented. Results. Cumulative complication rate was 66% (n = 27), with 11 developing within one year from surgery and 16 after one year (including five patients with both early and late complications). Ten graft failures (24%) and eight cases of reactive synovitis were observed (20%). All 11 patients with early complications and ten with late complications underwent reoperation (including five with another surgical procedure for early complications), amounting to a cumulative reoperation rate of 51% (n = 21). Revision ACL reconstruction was performed in one patient (2.4%). Median IKDC at latest follow-up was 89.7 (IQR 78.2 to 93.1), being significantly worse in the event of previous complications. Lachman test was positive in 56% (n = 15) of reconstructed knees. All norm-based SF-36 items were at or above median at latest follow-up, and did not differ depending on development of complications. Conclusion. Despite good functional and QoL-related results in the long term, the cumulative complication rate of 66%, including graft failures and reactive synovitis, has to be viewed with great concern. Cite this article: Bone Joint J 2022;104-B(2):242–248

Objectives. Ligaments which heal spontaneously have a healing process that is similar to skin wound healing. Menopause impairs skin wound healing and may likewise impair ligament healing. Our purpose in this study was to investigate the effect of surgical menopause on ligament healing in a rabbit medial collateral ligament model. Methods. Surgical menopause was induced with ovariohysterectomy surgery in adult female rabbits. Ligament injury was created by making a surgical gap in the midsubstance of the medial collateral ligament. Ligaments were allowed to heal for six or 14 weeks in the presence or absence of oestrogen before being compared with uninjured ligaments. Molecular assessment examined the messenger ribonucleic acid levels for collagens, proteoglycans, proteinases, hormone receptors, growth factors and inflammatory mediators. Mechanical assessments examined ligament laxity, total creep strain and failure stress. Results. Surgical menopause in normal medial collateral ligaments initiated molecular changes in all the categories evaluated. In early healing medial collateral ligaments, surgical menopause resulted in downregulation of specific collagens, proteinases and inflammatory mediators at 6 weeks of healing, and proteoglycans, growth factors and hormone receptors at 14 weeks of healing. Surgical menopause did not produce mechanical changes in normal or early healing medial collateral ligaments. With or without surgical menopause, healing ligaments exhibited increased total creep strain and decreased failure stress compared with uninjured ligaments. Conclusions. Surgical menopause did not affect the mechanical properties of normal or early healing medial collateral ligaments in a rabbit model. The results in this preclinical model suggest that menopause may result in no further impairment to the ligament healing process. . Cite this article: Bone Joint Res 2015;4:38–44

In-situ assessment of collateral ligaments strain could be key to improving total knee arthroplasty outcomes by improving the ability of surgeons to properly balance the knee intraoperatively. Ultrasound (US) speckle tracking methods have shown promise in their capability to measure in-situ soft tissue strain in large tendons but prior work has also highlighted the challenges that arise when attempting to translate these approaches to the in-situ assessment of collateral ligaments strain. Therefore, the aim of this project was to develop and validate an US speckle tracking method to specifically assess in-situ strains of both the MCL and LCL. We hypothesize that coefficients of determination (R. 2. ) would be above 0.90 with absolute differences below 0.50% strain for the comparison between US-based and the reference strain, with better results expected for the LCL compared with the MCL. Five cadaveric legs with total knee implants (NH019 2017-02-03) were submitted to a varus (LCL) and valgus (MCL) ramped loading (0 – 40N). Ultrasound radiofrequency (rf) data and reference surface strains data, obtained with 3D digital image correlation (DIC), were collected synchronously. Prior to processing, US data were qualitatively assessed and specimens displaying substantial imaging artefacts were discarded, leaving five LCL and three MCL specimens in the analysis. Ultrasound rf data were processed in Matlab (The MathWorks, Inc., Natick, MA) with a custom-built speckle tracking approach adapted from a method validated on larger tendons and based on normalized cross-correlation. Digital image correlation data were processed with commercial software VIC3D (Correlated Solutions, Inc., Columbia, SC). To optimize speckle tracking, several tracking parameters were tested: kernel and search window size, minimal correlation coefficient and simulated frame rate. Parameters were ranked according to three comparative measures between US- and DIC-based strains: R. 2. , mean absolute error and strains differences at 40N. Parameters with best average rank were considered as optimal. To quantify the agreement between US- and DIC-based strain of each specimen, the considered metrics were: R. 2. , mean absolute error and strain differences at 40N. The LCL showed a good agreement with a high average R. 2. (0.97), small average mean absolute difference (0.37%) and similar strains at 40N (DIC = 2.92 ± 0.10%; US = 2.99 ± 1.16%). The US-based speckle tracking method showed worse performance for the MCL with a lower average correlation (0.55). Such an effect has been observed previously and may relate to the difficulty in acquiring sufficient image quality for tracking the MCL compared to the LCL, which likely arises due to structural or mechanical differences; notably MCL is larger, thinner, more wrapped around the bone and stretches less. However, despite these challenges, the MCL tracking still showed small average mean absolute differences (0.44%) and similar strains at 40N (DIC = 1.48 ± 0.06%; US = 1.44 ± 1.89%). We conclude that the ultrasound speckle tracking method developed is ready to be used as a tool to assess in-situ strains of LCL. Concerning the MCL strain assessment, despite some promising results in terms of strain differences, further work on acquisition could be beneficial to reach similar performance

Abstract. Objectives. The study aims to determine whether an arthroscopic ligament reconstruction is necessary to relieve clinical ankle instability symptoms in patients with an MRI scan showing medial or lateral ligament tear. Methods. This was a single centre retrospective case series study of 25 patients with ankle instability and ligament tear on MRI scan who had undergone arthroscopic procedures from January 2015 to December 2018. Patients were followed up for an average period of 3 years postoperatively to check for any recurrence of symptoms. Results. Of the 25 patients, 23 had ATFL tear on MRI scan, and 2 had deltoid ligament tear. Examination under anaesthesia was stable in 13 patients and unstable in 12 patients. The majority of the patients (76%) had a simple arthroscopic ankle debridement and no ligament repair. Six patients needed Brostrom repair. Conclusions. Our study has shown that in patients with MRI proven ligament tear and clinical instability, a ligament reconstruction was unnecessary in most patients. The instability symptoms of patients were relieved by simple ankle arthroscopic debridement

Aims. The optimal procedure for the treatment of ossification of the posterior longitudinal ligament (OPLL) remains controversial. The aim of this study was to compare the outcome of anterior cervical ossified posterior longitudinal ligament en bloc resection (ACOE) with posterior laminectomy and fusion with bone graft and internal fixation (PTLF) for the surgical management of patients with this condition. Methods. Between July 2017 and July 2019, 40 patients with cervical OPLL were equally randomized to undergo surgery with an ACOE or a PTLF. The clinical and radiological results were compared between the two groups. Results. The Japanese Orthopaedic Association (JOA) score and recovery rate in the ACOE group were significantly higher than those in the PTLF group during two years postoperatively, provided that the canal occupying ratio (COR) was > 50%, or the K-line was negative. There was no significant difference in JOA scores and rate of recovery between the two groups in those in whom the COR was < 50%, or the K-line was positive. There was no significant difference in the Cobb angle between C2 and C7, sagittal vertical axis, cervical range of motion (ROM), and complications between the two groups. Conclusion. Compared with PTLF, ACOE is a preferred surgical approach for the surgical management of patients with cervical OPLL in that it offers a better therapeutic outcome when the COR is > 50%, or the K-line is negative, and it also preserves better cervical curvature and sagittal balance. The prognosis of ACOE is similar to that of PTLE when the COR is < 50%, or the K-line is positive. Cite this article: Bone Joint J 2023;105-B(4):412–421

Introduction. Ligament reconstruction following knee soft tissue injuries, such as posterior cruciate ligament (PCL) tears, aim to restore normal joint function and motion; however, persistant pathomechanical joint behavior indicates that there is room for improvement in current reconstruction techniques. Increased attention is being directed towards the roles of secondary knee stabilizers, in an attempt to better understand their contributions to kinematics of knees. The objective of this study is to characterize the relative biomechanical contributions of the posterior oblique ligament (POL) and the deep medial collateral ligament (dMCL) in PCL-deficient knees. We hypothesized that, compared with the POL, the dMCL would have a more substantial role in stabilizing the medial side of the knee, especially in flexion (slack POL). Methods. Seven fresh-frozen cadaveric knees were used in this study (age 40–62, 4 female, 3). Specimens were potted and mounted onto a VIVO joint motion simulator (AMTI). Once installed, specimens were flexed from 0 to 90 degrees with a 10 N axial load and all remaining degrees of freedom unconstrained. This was repeated with (a) a 67 N posterior load, (b) a 2.5 Nm internal or external rotational moment and (c) a 50 N posterior load and 2.5 Nm internal rotational moment applied to the tibia. During each resulting knee motion, the relative AP kinematics of the dMCL tibial insertion (approximated as the most medial point of the proximal tibia) with respect to the flexion axis of the femur (the geometric center axis, based on the posterior femoral condyles) were calculated at 0, 30, 60 and 90 degrees of flexion. These motions were repeated following dissection of the PCL and then further dissection of either medial ligament (4 POL, 3 dMCL). The changes in AP kinematics due to ligament dissection were analyzed using three-way repeated-measures ANOVA with a significance value of 0.05. Results. Dissection of the dMCL or POL did not result in a statistically significant increase in the posterior displacement of the medial tibial point under posterior directed force, internal rotation moments, or the combined posterior force plus internal rotation moment. Interestingly, under external moment loading, there was a statistically significant increase in anterior displacement of the medial tibia at all flexion angles after POL dissection, by up to 3.0+/−2.6 mm at 0 degrees. Dissection of the dMCL, however, did not have a significant affect. Conclusion. Our results showed that neither the POL nor dMCL play a significant role in resisting posterior tibial displacements on the medial side of a PCL deficient knee. Of the two, the POL appears to have a greater contribution towards preventing anterior translations, particularly when in extension. This finding is rational based on the anatomical path of this ligament wrapping around the femoral medial condyle under external rotational moments. In contrast with our hypothesis, it was observed that the dMCL had less of an effect on medial knee stability. Contributions of these ligaments could be further investigated using more complicated loading, such as those more representative of activities of daily living

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. Methods. This study was a retrospective case-control study using the UK Biobank to identify individuals reporting a history of cruciate ligament surgery. Data from verbal history and procedural codes recorded through the NHS were used to identify instances of TKA. Patient clinical and genetic data were used to identify risk factors for progression from cruciate ligament surgery to TKA. Individuals without a history of cruciate ligament reconstruction were used for comparison. Results. A total of 2,576 individuals with a history of cruciate ligament surgery were identified, with 290 (11.25%) undergoing TKA. In patients with prior cruciate ligament surgery, prevalence of TKA was 0.75% at age 45 years, 9.10% at age 65 years, and 20.43% at age 80 years. Patients with prior cruciate ligament surgery were 4.6 times more likely to have undergone TKA by age 55 years than individuals without prior cruciate ligament surgery. In the cruciate ligament surgery cohort, BMI > 30 kg/m. 2. (odds ratio (OR) 4.01 (95% confidence interval (CI) 2.74 to 5.87)), a job that always involved heavy manual or physical labour (OR 2.72 (95% CI 1.57 to 4.71)), or a job that always involved walking and standing (OR 2.58 (95% CI 1.58 to 4.20)) were associated with greater TKA odds. No single-nucleotide polymorphism (SNP) was associated with risk of TKA following cruciate ligament surgery. Conclusion. Patients with a history of prior cruciate ligament surgery have substantially higher risk of TKA and undergo arthroplasty at a relatively younger age than individuals without a history of prior cruciate ligament surgery. Physically demanding work and obesity were associated with higher odds of TKA after cruciate ligament surgery, but no SNP was associated with risk of TKA. Cite this article: Bone Joint J 2024;106-B(3):249–255

Aims. Patients with midcarpal instability are difficult to manage. It is a rare condition, and few studies have reported the outcomes of surgical treatment. No prospective or retrospective study has reported the results of arthroscopic palmar capsuloligamentous suturing. Our aim was to report the results of a prospective study of arthroscopic suture of this ligament complex in patients with midcarpal instability. Methods. This prospective single-centre study was undertaken between March 2012 and May 2022. The primary outcome was to evaluate the functional outcomes of arthroscopic palmar midcarpal suture. The study included 12 patients, eight male and four female, with a mean age of 27.5 years (19 to 42). They were reviewed at three months, six months, and one year postoperatively. Results. There was a significant improvement in flexion, extension, grip strength, abbreviated version of the Disabilities of the Arm, Shoulder and Hand questionnaire score, and pain, in all patients. After telephone contact with all patients in March 2023, at a mean follow-up of 3.85 years (2.2 to 6.25), no patient had a persistent or recurrent clunk. Conclusion. Arthroscopic suture of the midcarpal capsuloligamentous complex represents a minimally invasive, easy, and reproducible technique for the management of patients with midcarpal instbility, with a clear improvement in function outcomes and no complications. Cite this article: Bone Joint J 2024;106-B(3):262–267

Abstract. Introduction. We present a case series of patients that underwent knee ligament reconstruction with graft reinforcement using FibreTape (Arthrex), a 2mm wide non-biodegradable polyethylene tape. Outcomes and safety of this novel technique are reported. Methods. Data were collected from a prospectively maintained database from 03/2011 to 11/2019. All skeletally mature patients that underwent reinforced knee ligament reconstruction surgery at Basingstoke and North Hampshire Hospital were included. The cohort was interrogated for outcomes including failure, complications, and subjective patient reported outcomes at 6,12 and 24 months postoperatively. Results. 438 patients were eligible. The mean age was 33.4 years and 68% of them were males. This included 171 ACL reconstructions, 96 ACL with anterolatreal ligament reconstructions, 59 bicruciate reconstructions, 30 ACL with posterolateral corner, 49 posterior cruciate ligament with one other ligament and 33 other ligament reconstruction. Allograft was used for 125 patients. 338 cases related to primary reconstruction. The overall complication rate was 5.3%, with a 2.1% re-rupture rate. There were 9 patients with a re-rupture and 5 of them had undergone multiligament reconstruction. We found a statistically significant improvement in all subjective scoring indices post-operatively up to 2 years. There were no complications directly related to the use of ligament reinforcement. Conclusion. Graft reinforcement is a safe option in the management of knee ligament injuries. Encouraging results were observed in patient reported outcomes. Reinforcement is technically reproducible and may represent an answer for graft failure rates, especially in multiligament reconstructions. Further application and evaluation is necessary to confirm its benefit

Modeling the kinetic effects of the soft tissue structures is a major challenge for dynamic simulation of knees and other joints. We describe a technique whereby a multi-fiber ligament model is evolved to reproduce accurately the passive kinetics of a knee joint. The passive motion can be derived from patient-specific motion capture data. It may also be derived in-silico from a desired articular surface geometry, for example an implant or a surface model acquired by radiography. The technique operates by optimizing the tibial ligament insertion sites to minimize the change in strain energy through a specified range of motion. It is believed that the ligament model so produced is valuable for loaded kinetic and kinematic joint studies as well. The results therefore may be used to inform implant positioning during surgical planning

Aim. Arthroscopic interventions have revolutionized the treatment of joint pathologies. The appropriate diagnostics and treatment are required for infections after ligament reconstructions using non-resorbable material such as tendon grafts, anchors, and sutures, prone to biofilm formation. The infection rate is around 1% for knee and shoulder, while up to 4% for Achilles tendon reconstructions. Despite high number of these procedures worldwide, there is limited evidence about the best treatment protocol. Our study aimed to provide a general protocol for the treatment of small implants for soft tissue reconstruction. Method. Between 2019 and 2023, we treated 48 infections of ligament, meniscus, and tendon reconstructions out of 7291 related procedures performed in the same time period. Early infection (<30 days) were treated with an arthroscopic debridement and implant retention (DAIR), except Achilles tendons had open DAIR, while those with delayed or chronic infection (>30 days) were treated with extensive debridement and lavage combined with one-stage exchange (OSE) or implant removal. During surgery, at least 5 microbiological s and samples for histopathology were obtained. The removed material was sonicated. After surgery, all patients were one week on iv. antibiotics, followed by oral antibiofilm antibiotics for 6 weeks including rifampicin and/or a quinolone. All patients were followed for at least 1 year. Failure was defined as the need for additional revision surgery after finished iv. antibiotic treatment. Results. Among 48 patients, 38 were early and 10 were late acute or chronic infections. The incidence of infection for our cohort was 0.7%. We observed 27 infections after ligament reconstruction of the knee, 15 of the shoulder, 5 of the ankle, and 1 infection of the elbow joint. 40 patients were treated with DAIR, 5 with OSE, and 3 with implant removal. We had 11 C. acnes, 10 S. aureus, 6 S. epidermidis, 2 P. aeruginosa, 2 S. lugdunensis, 10 mixed flora, and 3 culture-negative infections. 12 patients received antibiotics before surgery, and all culture-negative infections were related to this subgroup. We observed 2 failures, both in a combination of proximal tibial osteotomy and ligament reconstruction of the knee joint. The success rate of our protocol was 96%. Conclusions. Prompt surgical treatment followed by 6 weeks of antibiotic treatment cured 96% of infections of small implants after reconstruction procedures of knee, shoulder, and ankle joints. Our study is the first to provide a treatment protocol for infections of small implants after ligament reconstruction procedures

Background. Supination-external rotation (SER) injuries make up 80% of all ankle fractures. SER stage 2 injuries (AITFL and Weber B) are considered stable. SER stage 3 injury includes disruption of the posterior malleolus (or PITFL). In SER stage 4 there is either medial malleolus fracture or deltoid injury too. SER 4 injuries have been considered unstable, requiring surgery. The deltoid ligament is a key component of ankle stability, but clinical tests to assess deltoid injury have low specificity. This study specifically investigates the role of the components of the deep deltoid ligament in SER ankle fractures. Aim. To investigate the effect of deep deltoid ligament injury on SER ankle fracture stability. Methods. Four matched pairs (8 specimens) were tested using a standardised protocol. Specimens were sequentially tested for stability when axially loaded with a custom rig with up to 750N. Specimens were tested with: ankle intact; lateral injury (AITFL and Weber B); additional posterior injury (PITFL); additional anterior deep deltoid; additional posterior deep deltoid; lateral side ORIF. Clinical photographs and radiographs were recorded. In addition, dynamic stress radiographs were performed after sectioning the deep deltoid and then after fracture fixation to assess tilt of the talus in eversion. Results. All specimens with an intact posterior deep deltoid ligament were stable when loaded and showed no talar tilt on dynamic assessment. Once the posterior deep deltoid ligament was sectioned there was instability in all specimens. Surgical stabilisation of the lateral side prevented talar shift but not talar tilt. Conclusion. If the posterior deep deltoid ligament is intact SER fractures may be managed without surgery in a plantigrade cast. Without immobilisation the talus may tilt, risking deltoid incompetence

There is currently no commercially available and clinically successful treatment for scapholunate interosseous ligament rupture, the latter leading to the development of hand-wrist osteoarthritis. We have created a novel biodegradable implant which fixed the dissociated scaphoid and lunate bones and encourages regeneration of the ruptured native ligament. To determine if scaphoid and lunate kinematics in cadaveric specimens were maintained during robotic manipulation, when comparing the native wrist with intact ligament and when the implant was installed. Ten cadaveric experiments were performed with identical conditions, except for implant geometry that was personalised to the anatomy of each cadaveric specimen. Each cadaveric arm was mounted upright in a six degrees of freedom robot using k-wires drilled through the radius, ulna, and metacarpals. Infrared markers were attached to scaphoid, lunate, radius, and 3rd metacarpal. Cadaveric specimens were robotically manipulated through flexion-extension and ulnar-radial deviation by ±40° and ±30°, respectively. The cadaveric scaphoid and lunate kinematics were examined with 1) intact native ligament, 2) severed ligament, 3) and installed implant. Digital wrist models were generated from computed tomography scans and included implant geometry, orientation, and location. Motion data were filtered and aligned relative to neutral wrist in the digital models of each specimen using anatomical landmarks. Implant insertion points in the scaphoid and lunate over time were then calculated using digital models, marker data, and inverse kinematics. Root mean squared distance was compared between severed and implant configurations, relative to intact. Preliminary data from five cadaveric specimens indicate that the implant reduced distance between scaphoid and lunate compared to severed configuration for all but three trials. Preliminary results indicate our novel implant reduced scapho-lunate gap caused by ligament transection. Future analysis will reveal if the implant can achieve wrist kinematics similar to the native intact wrist

Aims. Complete ruptures of the ulnar collateral ligament (UCL) of the thumb are a common injury, yet little is known about their current management in the UK. The objective of this study was to assess the way complete UCL ruptures are managed in the UK. Methods. We carried out a multicentre, survey-based cross-sectional study in 37 UK centres over a 16-month period from June 2022 to September 2023. The survey results were analyzed descriptively. Results. A total of 37 centres participated, of which nine were tertiary referral hand centres and 28 were district general hospitals. There was a total of 112 respondents (69 surgeons and 43 hand therapists). The strongest influence on the decision to offer surgery was the lack of a firm ‘endpoint’ to stressing the metacarpophalangeal joint (MCPJ) in either full extension or with the MCPJ in 30° of flexion. There was variability in whether additional imaging was used in managing acute UCL injuries, with 46% routinely using additional imaging while 54% did not. The use of a bone anchor was by far the most common surgical option for reconstructing an acute ligament avulsion (97%, n = 67) with a transosseous suture used by 3% (n = 2). The most common duration of immobilization for those managed conservatively was six weeks (58%, n = 65) and four weeks (30%, n = 34). Most surgeons (87%, n = 60) and hand therapists (95%, n = 41) would consider randomizing patients with complete UCL ruptures in a future clinical trial. Conclusion. The management of complete UCL ruptures in the UK is highly variable in certain areas, and there is a willingness for clinical trials on this subject. Cite this article: Bone Jt Open 2024;5(8):708–714

Objectives. Congenital cruciate ligament deficiency is a rare condition that may occur in isolation or in association with longitudinal limb deficiencies such as fibular hemimelia or proximal femoral focal deficiency. Often anomalies of the menisci and their attachments can be very abnormal and impact on surgical management by standard techniques. Arthroscopic surgical knee reconstruction is undertaken to improve symptomatic instability and/or to stabilise and protect the knee for future planned limb lengthening surgery. The aim of this study is to evaluate the arthroscopic findings of patients undergoing surgery for congenital cruciate ligament deficiency, and specifically to determine the frequency and types of meniscal anatomical variations seen in these cases. Methods. Patients undergoing surgery for congenital cruciate ligament deficiency were identified from a prospectively collated database. Diagnosis was confirmed through review of the clinical notes and imaging. Operative notes and 4K saved arthroscopic images and video recordings for these cases were reviewed. Results. Over a six-year period (July 2017 – September 2023), 42 patients underwent surgery for congenital ligament deficiency and tibiofemoral instability (45 surgical episodes). Median age of patients at time of surgery was 10 years (range 4 – 17 years). The most frequent diagnosis was congenital longitudinal limb deficiency syndromes in 27 cases, with the most frequent being fibular hemimelia. Isolated congenital ligament deficiency without any other associated extra-articular manifestations occurred in 11 cases. Absence of meniscal root attachments or hypertrophy of meniscofemoral ligaments acting as ‘pseudo-cruciates’ were seen in over 25% of patients. In isolated ACL deficiency these were injured causing onset of instability symptoms and pain following trauma. Often these abnormal structures required addressing to allow surgical reconstruction. Conclusions. Our findings demonstrate that there are often meniscal variations seen in association with congenital absence or hypoplasia of the cruciate ligaments. In these patients hypertrophied meniscofemoral ligaments may act as cruciate-like structures and play a role in providing a degree of sagittal plane stability to the knee. However, when the knee becomes unstable to the point that cruciate ligament reconstruction is indicated, these meniscal variants may often require stabilisation using complex meniscal root repair techniques or variations to standard cruciate ligament reconstruction techniques to accommodate the variant anatomy

Aims. In the native hip, the hip capsular ligaments tighten at the limits of range of hip motion and may provide a passive stabilizing force to protect the hip against edge loading. In this study we quantified the stabilizing force vectors generated by capsular ligaments at extreme range of motion (ROM), and examined their ability to prevent edge loading. Methods. Torque-rotation curves were obtained from nine cadaveric hips to define the rotational restraint contributions of the capsular ligaments in 36 positions. A ligament model was developed to determine the line-of-action and effective moment arms of the medial/lateral iliofemoral, ischiofemoral, and pubofemoral ligaments in all positions. The functioning ligament forces and stiffness were determined at 5 Nm rotational restraint. In each position, the contribution of engaged capsular ligaments to the joint reaction force was used to evaluate the net force vector generated by the capsule. Results. The medial and lateral arms of the iliofemoral ligament generated the highest inbound force vector in positions combining extension and adduction providing anterior stability. The ischiofemoral ligament generated the highest inbound force in flexion with adduction and internal rotation (FADIR), reducing the risk of posterior dislocation. In this position the hip joint reaction force moved 0.8° inbound per Nm of internal capsular restraint, preventing edge loading. Conclusion. The capsular ligaments contribute to keep the joint force vector inbound from the edge of the acetabulum at extreme ROM. Preservation and appropriate tensioning of these structures following any type of hip surgery may be crucial to minimizing complications related to joint instability. Cite this article: Bone Joint Res 2021;10(9):594–601

Purpose. We conducted a prospective study to investigate the role of the LARS ligament system to reconstruct the posterior cruciate ligament and the postero-lateral corner of the knee. We present a prospective single surgeon case series to evaluate early clinical and functional outcomes of postero-lateral corner and posterior cruciate ligament reconstruction in the knee using the LARS (ligament Augmentation and Reconstruction System) artificial ligament. 23 patients with multi-ligament knee injuries or isolated PCL injuries were treated with a mean follow up of 8 months (range: 2-37 months). Outcomes were assessed using the modified International Knee Documentation Committee score, and a modified Tegner- Lysholm score. 2 patients had acute reconstructive surgery within 7 days of injury, 5 patients within 3 months (semi-acute) and 16 were chronic cases that were operated on after three months from the date of injury. The LARS ligament reconstruction achieved a significant improvement between preoperative and postoperative assessment in relation to knee stability, function and patient satisfaction. The sooner the patients were treated the greater the improvements in functional scores were noted. Most patients achieved a full functional range of movement within six months. We had 2 complications, one superficial wound infection and one stiff knee requiring a manipulation. To date we have had no LARS ligament failures. In the short term the LARS functions well, with high clinical patient satisfaction, no signs of progressive laxity, synovitis or failure. We found no significant difference in functional score post reconstruction between the isolated PCL reconstructions and the multi ligament reconstructions. Our results show no early signs of the problems associated with synthetic grafts used in the past. Such grafts appear to be an attractive alternative to the use of autografts and allografts

Poor availability of allografts in South Africa has led to an increased use of synthetic augmentation to stabilize knee joints in the treatment of knee dislocations. This study aims to evaluate multiligament knee injuries treated with a posterior cruciate ligament internal brace. The study included patients with knee dislocations who were treated with a PCL internal brace. The internal brace involved the insertion of a synthetic suture tape, which was drilled into the femoral and tibial footprint. Chronic injuries were excluded. Patient-reported outcome scores (PROMs), range of motion, stress X-Rays, and MRI scans were reviewed to assess outcomes. Acceptable outcomes were defined as a Lysholm score of 84 or more, with grade II laxity in no more than one ligament and a range of motion from full extension to 90° or more. The study included eight patients, with a median age of 42, of which five were female. None of the patients had knee flexion less than 90° or an extension deficit of more than 20°. PROMs indicated acceptable outcomes (EQ5D, Tegner Lysholm). Stress radiographs showed less than 7mm (Grade I) of posterior translation laxity in all patients. Four patients underwent MRI scans 1–2 years after the initial surgery, which revealed healing of the PCL in all patients. However, increased signal in a continuous ligament suggested only partial healing in two patients. Tunnel widening of 200% and 250% was noted around the tibial and femoral PCL footprints, respectively. All patients demonstrated stable knees and acceptable PROMs. Tunnel widening was observed in all patients who had MRI scans. Factors such as suspensory fixation, anisometric tunnel position, and the absence of PCL tear repair may have contributed to the tunnel widening

Introduction and Objective. The human body is designed to walk in an efficient way. As energy can be stored in elastic structures, it is no surprise that the strongest elastic structure of the human body, the iliofemoral ligament (IFL), is located in the lower limb. Numerous popular surgical hip interventions, however, affect the structural integrity of the hip capsule and there is a growing evidence that surgical repair of the capsule improves the surgical outcome. Though, the exact contribution of the iliofemoral ligament in energy efficient hip function remains unelucidated. Therefore, the objective of this study was to evaluate the influence of the IFL on energy efficient ambulation. Materials and Methods. In order to assess the potential passive contribution of the IFL to energy efficient ambulation, we simulated walking using the large public dataset (n=50) from Schreiber in a the AnyBody musculoskeletal modeling environment with and without the inclusion of the IFL. The work required from the psoas, iliacus, sartorius, quadriceps and gluteal muscles was evaluated in both situations. Considering the large uncertainty on ligament properties a parameter study was included. Results. A significant reduction in the active component of all hip flexors was observed when the IFL is intact. The required muscle work was found to be reduced by as much as 48% (CI: 29–62%), 61% (CI: 35–84%) and 38% (CI: 2–69%) for the psoas, iliacus, and sartorius muscle respectively. The IFL inclusion has no major effect on the required work from the quadriceps and the gluteal muscle group. The energy storage in the IFL is largest at maximal hip extension and the contribution to forward motion is the largest at the start of the swing phase. Conclusions. The iliofemoral ligament seems to be a crucial structure in energy efficient walking. The findings support need for meticulous reconstruction of the capsule ligament in case of surgical damage

This study aims to create a novel computational workflow for frontal plane laxity evaluation which combines a rigid body knee joint model with a non-linear implicit finite-element model wherein collateral ligaments are anisotropically modelled using subject-specific, experimentally calibrated Holzpfel-Gasser-Ogden (HGO) models. The framework was developed based on CT and MRI data of three cadaveric post-TKA knees. Bones were segmented from CT-scans and modelled as rigid bodies in a multibody dynamics simulation software (MSC Adams/view, MSC Software, USA). Medial collateral and lateral collateral ligaments were segmented based on MRI-scans and are modelled as finite elements using the HGO model in Abaqus (Simulia, USA). All specimens were submitted varus/valgus loading (0-10Nm) while being rigidly fixed on a testing bench to prevent knee flexion. In subsequent computer simulations of the experimental testing, rigid bodies kinematics and the associated soft-tissue force response were computed at each time step. Ligament properties were optimised using a gradient descent approach by minimising the error between the experimental and simulation-based kinematic response to the applied varus/valgus loads. For comparison, a second model was defined wherein collateral ligaments were modelled as nonlinear no-compression spring elements using the Blankevoort formulation. Models with subject-specific, experimentally calibrated HGO representations of the collateral ligaments demonstrated smaller root mean square errors in terms of kinematics (0.7900° +/− 0.4081°) than models integrating a Blankevoort representation (1.4704° +/− 0.8007°). A novel computational workflow integrating subject-specific, experimentally calibrated HGO predicted post-TKA frontal-plane knee joint laxity with clinically applicable accuracy. Generally, errors in terms of tibial rotation were higher and might be further reduced by increasing the interaction nodes between the rigid body model and the finite element software. Future work should investigate the accuracy of resulting models for simulating unseen activities of daily living