Anterior cruciate ligament (ACL) ruptures are debilitating injuries, often managed via ACL reconstruction (ACLR). Reduced range of motion (ROM), particularly loss of extension (LOE), is the most significant contributor to post-operative patient dissatisfaction. LOE may preclude return to sport, increase re-rupture rates and precipitate osteoarthritis. Passive LOE rates following ACLR have been reported at 15%. However, LOE incidence during active tasks are poorly characterised. Our review sought to determine knee extension angles for active tasks following an ACL injury or ACLR. We hypothesised greater incidences of active LOE following ACL injury or ACLR, compared to uninjured contralateral limbs or controls. We systematically searched MEDLINE, Embase, Cochrane Library, Scopus, SPORTDiscus, and relevant trials databases for English articles. Included were cohort, cross-sectional, case-controlled or randomised controlled trials analysing adults with ACL injury treated surgically or otherwise, with at least 12-weeks follow-up and reporting either active knee extension angle, active LOE angles or incidence of active knee LOE during functional tasks. The protocol was registered on PROSPERO (CRD42018092295). Subsequent meta-analysis was performed. After screening, 71 eligible articles were included. Studies were heterogenous in design and quality. Included tasks were overground walking (n=44), running (n=3), hopping/jumping/cutting (n=11) single-leg landing (n=7), and stair climbing (n=6). LOE incidence varied depending on functional activities (33.95-92.74%). LOE incidence did not vary depending on ACL status (67.26% vs. 65.90% vs. 62.57% for ACL intact, ACLD and ACLR, respectively). We observed no difference in active LOE incidence according to ACL status. Importantly, the observed incidence for active LOE was reliably higher than previously reported rates for passive measures. Given the discrepancy between active and passive LOE incidence, clinicians may advisably prioritise active ROM during ACL rehabilitation

Anterior cruciate ligament (ACL) rupture with associated meniscal pathology commonly occurs in a young, active population. Preserving a greater proportion of the meniscus may improve long-term outcomes by maintaining shock absorption and knee stability. However, meniscal repair procedures involve longer healing and rehabilitation than meniscal debridement, which could affect return to work and activity. The purpose of this study was to examine the functional outcomes and quality of life scores through two years in patients undergoing ACL reconstruction (ACL-R) who had meniscal repair, meniscal debridement, or no meniscal damage at the time of reconstruction. Data for 1814 skeletally mature patients with isolated primary ACL-R was prospectively collected at a single centre from January 2010 to December 2015. Functional testing of operative to non-operative limb performance was completed at one- and two-years following surgery and included single-leg balance, single-leg hop for distance, timed six-meter hop, triple-hop for distance, and triple cross-over hop for distance. ACL-Quality-of-life questionnaires (ACL-QoL) were completed pre-operatively and at 1- and 2-years post-operatively. Descriptive statistics were completed for patient demographics and intra-operative pathology. Unpaired t-tests using 95% confidence intervals were conducted to compare groups. The patient cohort was 45% female, with a mean age of 31 years (SD 11, range 14–66). Meniscal injury was detected in 1229/1814 knees (67.8%). There were 729 debridements and 538 repairs performed. Graft choice was hamstring autograft in 85.8% of cases, bone-patellar-tendon-bone autograft in 2.5%, allograft in 10.1% and other graft types in 1.5%. Pre-operative ACL-QoL scores were 29 and 28.5 for knees without and with meniscal damage, respectively (p>0.05). Of 1814 patients, 1269 (69.9%) completed the ACL-QoL at the two-year appointment, and 1225 (67.5%) completed the functional testing. At two years post-operative, patients with no meniscal damage at surgery demonstrated superior limb symmetry performance on triple-hop for distance compared to patients with meniscal damage (98.4% vs 97.1%, p < 0 .05, CI 0.1–2.5%). No other functional testing parameters showed statistical significance. There was no difference in functional outcome between patients undergoing an isolated meniscal repair versus debridement at one- or two-years. ACL-QoL scores were statistically significantly higher at one- and two-years post-operative for patients without meniscal damage (1-year: 73 vs 70.2, p < 0 .05, CI 0.51–5.1, 2-years: 79.2 vs 76.1, p < 0 .05, CI 0.79–5.4). ACL-QoL scores were minimally higher for isolated meniscal debridement compared to isolated meniscal repair at both time points (1-year: 71.4 vs 68, p < 0 .05, CI 0.4–6.4, 2-years: 78.3 vs 74, p < 0 .05, CI 1.3–7.3). Functional outcomes do not differ at one or two years post-operatively for patients undergoing meniscal repair versus debridement concomitant with ACL-R. Quality of life scores were statistically significantly higher for the patients with no meniscal pathology at both one- and two-years post-operative. ACL-QoL scores were also statistically significantly different for the meniscal repair and debridement groups however these differences are unlikely to be clinically significant. Extended follow-up is needed to determine if the differences detected in ACL-QoL scores are sustained over time, as well as the long-term role of meniscal injury on functional outcomes

With associated snow sports injury risks being well documented, the scope for preventative medicine is clear. This article focuses on potential precautions taken by skiers/snowboarders and how they vary between different snow sport groups. A total of 181 randomly selected individuals from the Whistler/Blackcomb Medical Centre, Canada, took part in this questionnaire-based cohort study, examining snow sports activity, preventive measures, and protective equipment use. Most individuals were ski area residents of advanced expertise, with 50% having had a previous snow-riding injury. The most commonly reported significant ski injury was anterior cruciate ligament (ACL) rupture, while in snowboarders, it was wrist fracture. Skiers were more likely to improve fitness levels before going onto the slopes, whereas crossover riders (both skiing and snowboarding) were more likely to take lessons. Most individuals used eye and sun protection and had adequately warm clothing. Beyond basic precautions, protective equipment and preventive measures are used infrequently. It is suggested that by increasing awareness and use of such equipment, injury rates may be reduced

Early stabilisation after an anterior cruciate ligament (ACL) rupture reduces future meniscal injury. We may therefore expect protection of articular cartilage from ACL reconstruction, but this has yet to be shown. Our aim wasto determine the effect of meniscal injury on the long term risk of osteoarthritis (OA) following ACL reconstruction using Single Photon Emission Computed Tomography (SPECT, a 3 dimensional radionuclide scan). We studied a prospective series of 31 patients (mean age at injury of 29 years) who had bone-patellar tendon-bone ACL reconstruction for unstable, ACL deficient knees. Mean follow-up was 10 years (range 9-13). Patients were separated into two groups according to the status of their menisci at the time of ACL reconstruction, those with intact menisci in group 1 (n=15) and those who required partial meniscectomy in group 2 (n=16). The contra-lateral normal knee was used as a control. All knees were clinically stable with high clinical scores (mean Lysholm score 93 and mean Tegner activity score 6). In group 1 (intact menisci) only one patient (7%) had clinical symptoms of OA and was the only patient with increased uptake on SPECT compatible with early OA. In group 2 (partial meniscectomy), two had clinical symptoms of osteoarthritis, and five patients (32%) had increased uptake on SPECT compatible with early OA. None of the control knees had early OA on SPECT. The prevalence of OA 10 years post ACL reconstruction, using the most sensitive investigation available, is very low in patients who had intact menisci (7%), but increases 5 fold (32%) if a meniscal tear was present. We recommend early ACL reconstruction to preserve the menisci to minimise the long term risk of OA

Introduction. Anterior cruciate ligament (ACL) rupture is a common sporting injury, often managed surgically with patella-tendon or hamstrings autograft. Surgeons are under increasing pressure for open transparent assessment of their performance. Scoring systems can be used to assess outcome. More than 50 different scoring systems have been identified to assess the ACL deficient knee. Aims. The survey is investigating the use of ACL scoring systems between knee surgeons in the United Kingdom as a method of assessing performance. Method. 134 knee surgeons in the United Kingdom, performing ACL reconstruction, were asked to complete a written questionnaire regarding their use of scoring systems & outcome measures. Written questionnaires were sent and responses were received by post. Results. 81 (60%) surgeons responded to the questionnaire by stating their preferred scoring system. 40 (49%) surgeons routinely use ACL scoring systems versus 41 (51%) surgeons who do not. The Lysholm (I and II) knee scoring scale (80%) and Tegner activity score (67.5%) were most commonly used (57.5% both of them) followed by the Knee injury and osteoarthritis outcome score (KOOS) (30%), International Knee Documentation Committee (IKDC) subjective knee score (22.5%), Medical Outcome Study 12 Item Short Form (SF12) (20%), the Medical Outcome Study 36 Item Short Form (SF 36) (12.5%), Cincinnati Knee Scoring System (10%), and ACL Quality of Life scoring system (7.5%). Recommendations. The routine use of ACL scoring systems by 49% of surgeons raises the question - should all surgeons be using scoring systems in their ACL practice? This would be relatively easy to do as most patients are followed up post operatively for 6 months. This will help to adopt a transparent assessment of the performance of every consultant to the procedure they perform

Anterior Cruciate Ligament (ACL) rupture is one of the commonest injuries in sports medicine. However, the rates of the reported graft re-rupture range from 2–10%, leading to around 3000 to 10000 revision ACL reconstructions in United States per annum. Inaccurate tunnel positions are considered to be one of the commonest reasons leading to failure and subsequent revision surgery. Additionally, there remains no consensus of the optimal position for ACL reconstructions. The positions of the bone tunnels in patients receiving ACL reconstruction are traditionally assessed using X-rays. It is well known that conventional X-ray is not a precise tool in assessing tunnel positions. Thus, there is a recent trend in using three-dimensional (3D) CT. However, routine CT carries a major disadvantage in terms of significant radiation hazard. In addition, it is both inconvenient and expensive to use CT as a regular assessment tools during the follow-up. The goal of the present work is to develop a novel 2D-3D registration method using single X-ray image and a surface model. By performing such registration for two post-operative X-rays, we can further calculate the 3D tunnel positions after ACL reconstructions. Our framework consists of five parts: (1) a surface model of the knee, (2) a 2D-3D registration algorithm, (3) a 3D tunnel position calculation, (4) a graphic user interface (GUI), and (5) a semi-transparency rendering. Among them, the crucial part is our 2D-3D registration method that estimates the relative position of the knee model in the imaging coordinate system. Once registered, the 3D position of an ACL tunnel in the knee model is calculated from the imaging geometry. The only interaction required is to mark the ACL tunnels on the X-rays through the GUI. We propose two 2D-3D registration methods. One is a contour-based method that uses pure geometric information. Most methods in this category accomplish the registration by extracting contours in X-rays, establishing their correspondences on the 3D model, and calculating the registration parameters. Unlike these methods, which need point-to-point correspondences, our method optimises the registration parameters in a statistical inference framework without giving or establishing point-to-point correspondences. Due to the use of the statistical inference, our method is robust to the spurs and broken contours that automatically extracted by the contour detector. The second method takes into account both the geometric shape of the object and the intensity property (intensity changes) of the image, where the intensity changes can be detected via image gradients. The use of gradient is based on the interpretation that two images are considered similar, if intensity changes occur at the same locations. The angles between the image gradients and the projected surface normals were used as a distance measure. The summation of the measures for all projected model points gives us the gradient term, which we multiply the contour-based measurement. Multiplication is preferred over addition because addition of the terms would require both terms to be normalised. To evaluate the feasibility of our methods, a simulation study was conducted using Digitally Reconstructed Radiographs (DRR) of a sawbone underwent a single-bundle ACL reconstruction performed by an experienced orthopedic surgeon. The real position of the bone tunnel entry point was obtained using the CT images, which were acquired using a custom-made well-calibrated cone-beam CT. The knee model was built by downsampling and smoothing the high-resolution CT reconstructions. It is important in our experiments to make the model different from the original reconstruction since this simulates the condition in which patient's CT is unavailable. Two DRRs generated from approximately anteroposterior and lateral viewpoints were used. For each DRR, 50 trials of 2D-3D registration were carried out for the femoral part using 50 different initialisations, which were randomly selected from the values independently and uniformly distributed within ±10 degrees and ±10 mm of the ground-truth. Compared with the ground-truth established using the CT images, our single image contour-based method achieved accurate estimations in rotations and in-plane translations, which were (−0.67±1.38, −0.98±0.84, −0.42±0.71) degrees and (0.11±0.26, −0.06±1.20) mm for the anteroposterior image, and (−0.78±0.76, −0.37±0.87, 0.70±0.88) degrees and (−0.14±0.22, 0.31±0.71) mm for the lateral one, respectively. The same experiments were also performed using the second method. However, it did not produce desirable results in our experiments. The tunnel entry point was then calculated using the averaged registration result of our contour-based method. The entry point of the tunnel was obtained with high accuracy of 1.25 mm distance error from the real position of the entry point. For the 2D-3D registration, the estimated off-plane translations showed relatively low accuracy. It is well known that the depth can be difficult to be accurately estimated using one single image. As the result showed, the accuracy in rotations and in-plane translations is more important for ACL tunnel position estimation in our framework. As for the image gradient, it is too sensitive to the small perturbation caused by image noises. A more robust way of integrating the gradient information into our contour-based method is required. We propose a novel approach for estimating the 3D position of bone tunnels in ACL reconstruction using two post-operative X-rays. It was tested in a sawbone study using DRRs. The most significant advantage of our approach is to potentially eliminate the necessity of acquiring a patient's CT. The success in developing and validating the proposed workflow will allow convenient and precise assessment of tunnel positions in ACL reconstruction with minimal risk of radiation hazard

Treatment for osteoarthritis (OA) has traditionally focused on joint replacement for end-stage disease. An increasing number of surgical and pharmaceutical strategies for disease prevention have now been proposed. However, these require the ability to identify OA at a stage when it is potentially reversible, and detect small changes in cartilage structure and function to enable treatment efficacy to be evaluated within an acceptable timeframe. This has not been possible using conventional imaging techniques but recent advances in musculoskeletal imaging have been significant. In this review we discuss the role of different imaging modalities in the diagnosis of the earliest changes of OA. The increasing number of MRI sequences that are able to non-invasively detect biochemical changes in cartilage that precede structural damage may offer a great advance in the diagnosis and treatment of this debilitating condition.

Cite this article: Bone Joint J 2013;95-B:738–46.