Anterior cruciate ligament (ACL) injuries are among the most common and debilitating knee injuries in professional athletes with an incidence in females up to eight-times higher than their male counterparts. ACL injuries can be career-threatening and are associated with increased risk of developing knee osteoarthritis in future life. The increased risk of ACL injury in females has been attributed to various anatomical, developmental, neuromuscular, and hormonal factors. Anatomical and hormonal factors have been identified and investigated as significant contributors including osseous anatomy, ligament laxity, and hamstring muscular recruitment. Postural stability and impact absorption are associated with the stabilizing effort and stress on the ACL during sport activity, increasing the risk of noncontact pivot injury. Female patients have smaller diameter hamstring autografts than males, which may predispose to increased risk of re-rupture following ACL reconstruction and to an increased risk of chondral and meniscal injuries. The addition of an extra-articular tenodesis can reduce the risk of failure; therefore, it should routinely be considered in young elite athletes. Prevention programs target key aspects of training including plyometrics, strengthening, balance, endurance and stability, and neuromuscular training, reducing the risk of ACL injuries in female athletes by up to 90%. Sex disparities in access to training facilities may also play an important role in the risk of ACL injuries between males and females. Similarly, football boots, pitches quality, and football size and weight should be considered and tailored around females’ characteristics. Finally, high levels of personal and sport-related stress have been shown to increase the risk of ACL injury which may be related to alterations in attention and coordination, together with increased muscular tension, and compromise the return to sport after ACL injury. Further investigations are still necessary to better understand and address the risk factors involved in ACL injuries in female athletes. Cite this article: Bone Jt Open 2024;5(2):94–100

Aims. The aim of this study was to report the pooled prevalence of post-traumatic osteoarthritis (PTOA) and examine whether the risk of developing PTOA after anterior cruciate ligament (ACL) injury has decreased in recent decades. Methods. The PubMed and Web of Science databases were searched from 1 January 1980 to 11 May 2022. Patient series, observational studies, and clinical trials having reported the prevalence of radiologically confirmed PTOA after ACL injury, with at least a ten-year follow-up, were included. All studies were analyzed simultaneously, and separate analyses of the operative and nonoperative knees were performed. The prevalence of PTOA was calculated separately for each study, and pooled prevalence was reported with 95% confidence intervals (CIs) using either a fixed or random effects model. To examine the effect of the year of injury on the prevalence, a logit transformed meta-regression analysis was used with a maximum-likelihood estimator. Results from meta-regression analyses were reported with the unstandardized coefficient (β). Results. The pooled prevalence of PTOA was 37.9% (95% CI 32.1 to 44) for operatively treated ACL injuries with a median follow-up of 14.6 years (interquartile range (IQR) 10.6 to 16.7). For nonoperatively treated ACL injuries, the prevalence was 40.5% (95% CI 28.9 to 53.3), with a median of follow-up of 15 years (IQR 11.7 to 20.0). The association between the year of operation and the prevalence of PTOA was weak and imprecise and not related to the choice of treatment (operative β -0.038 (95% CI -0.076 to 0.000) and nonoperative β -0.011 (95% CI -0.101 to 0.079)). Conclusion. The initial injury, irrespective of management, has, by the balance of probability, resulted in PTOA within 20 years. In addition, the prevalence of PTOA has only slightly decreased during past decades. Therefore, further research is warranted to develop strategies to prevent the development of PTOA after ACL injuries. Cite this article: Bone Joint J 2023;105-B(11):1140–1148

The October 2023 Sports Roundup³⁶⁰ looks at: Extensor mechanism disruption in the treatment of dislocated and multiligament knee injuries; Treatment of knee osteoarthritis with injection of stem cells; Corticosteroid injection plus exercise or exercise alone as adjuvants for patients with plantar fasciitis?; Generalized joint hypermobility and a second ACL injury?; The VISA-A ((sedentary) questionnaire for Achilles tendinopathy?.

A method is proposed to assess risk parameters of anterior cruciate ligament (ACL) injury using human pose estimation (HPE) and a single stereo depth camera. Detectron2 is used to identify key points of a subject performing a single leg jump test. This allows dynamic pivot of the knee to be assessed during landing using four risk parameters: knee valgus, knee translation in the coronal plane, pelvic tilt, and head-ankle alignment (body sway). Results show the model has an accuracy of 7° in angular measurements and 38 mm in linear measurements. Compared to previous studies, which only consider front-on analysis, this method has partially reduced accuracy in linear measurements and half the accuracy in angular measurements. Despite this, coupling information from multiple risk parameters reduces the accuracy required on any one parameter and the use of a single depth camera enables reliable analysis at a subject orientation of ±45° relative to the camera. These factors create a novel solution, proposing the ability for broad evaluation of ACL risk parameters in environments outside a testing laboratory, which has not been done before

Abstract. Background. Anterior cruciate ligament (ACL) injuries with coinciding posterolateral tibial plateau (PLTP) depression fractures are rare. According to the most up to date literature, addressing the PLTP is crucial in preventing failure of the ACL. However, the surgical management of these injuries pose a great challenge to orthopaedic surgeons, given the anatomical location of the depressed PTP fragment. We report a case of a 17-year-old patient presenting to our department with this injury and describe a novel fixation method, that has not been described in the literature. Surgical Technique. A standard 2-portal arthroscopy is used to visualise the fractures. The PLTP is addressed first. With the combined use of arthroscopy and fluoroscopy, a guide pin is triangulated from the anteromedial aspect of the tibia, towards the depressed plateau fragment. Once the guide pin is approximately 1cm from the centre of the fragment, it is over-drilled with a cannulated drill, and simultaneously bluntly punched up to its original anatomical location. Bone graft is then used to fill the void, supported by two subchondral screws. Both fluoroscopy and arthroscopy are used to confirm adequacy of fixation. Finally, the tibial spine avulsion fracture is repaired arthroscopically using the standard suture bridging technique. Conclusion. We describe a novel, one-stage, minimally invasive approach that addresses both the ACL injury and PLTP fracture. We highlight the advantages of utilising this approach and functional outcomes

Introduction. Anterior cruciate ligament (ACL) injuries represent a significant burden of disease to the orthopaedic surgeon and often necessitate surgical reconstruction in the presence of instability. The hamstring graft has traditionally been used to reconstruct the ACL but the quadriceps tendon (QT) graft has gained popularity due to its relatively low donor site morbidity. Methods. This is a single centre comparative retrospective analysis of prospectively collected data of patients who had an ACL reconstruction (either with single tendon quadrupled hamstring graft or soft tissue quadriceps tendon graft). All surgeries were performed by a single surgeon using the All-inside technique. For this study, there were 20 patients in each group. All patients received the same post-operative rehabilitation protocol and were added to the National Ligament Registry to monitor their patient related outcome scores (PROM). Results. The average age of patients in the QT group was 29 years (16 males, 4 females) and in the hamstring group was 28 years (18 males, 2 females). The most common mechanism of injury in both groups was a contact twisting injury. There were no statistical differences between the two patient groups in regards to PROMS and need for further revision surgery as analysed on the National Ligament Registry. Conclusions. The all soft tissue QT graft seems to be equivocal to quadrupled hamstring graft in terms of patient function and recovery graft characteristics. Further research may be needed to elucidate the long-term results of the all soft tissue QT graft given its recent increase in use

The bone-patellar tendon-bone (BTB) autograft has a lower rate of graft failure but a higher rate of contralateral anterior cruciate ligament (ACL) injury after primary ACL reconstruction. Subsequent contralateral injury may be a marker of success of the BTB graft, but it is unclear whether the type of graft influences the rate of return to sport. This study aimed to compare the rates of return to weekly sport and return to preinjury activity levels between the BTB and hamstring tendon autografts following primary ACL reconstruction. Prospective data on primary ACL reconstructions recorded in the New Zealand ACL Registry between April 2014-November 2019 were analyzed. The primary outcome was return to weekly sport, defined as a Marx activity score of 8, at 2-year follow-up. The secondary outcome was return to preinjury activity level, defined as a post-operative Marx activity score that was equal or greater to the patient's preinjury Marx score. Return to sport was compared between the BTB and hamstring tendon autografts via multivariate binary logistic regression with adjustment for patient demographics. 4259 patients were analyzed, of which 50.3% were playing weekly sport (n = 2144) and 28.4% had returned to their preinjury activity level (n = 1211) at 2-year follow-up. A higher rate of return to weekly sport was observed with the BTB autograft compared to the hamstring tendon autograft (58.7% versus 47.9%, adjusted odds ratio = 1.23, p = 0.009). Furthermore, the BTB autograft had a higher rate of return to preinjury activity levels (31.5% versus 27.5%, adjusted odds ratio = 1.21, p = 0.025). The BTB autograft is associated with a higher return to sport and may explain the higher rate of contralateral ACL injury following primary ACL reconstruction

Aims. The aim of this study was to estimate the incremental use of resources, costs, and quality of life outcomes associated with surgical reconstruction compared to rehabilitation for long-standing anterior cruciate ligament (ACL) injury in the NHS, and to estimate its cost-effectiveness. Methods. A total of 316 patients were recruited and randomly assigned to either surgical reconstruction or rehabilitation (physiotherapy but with subsequent reconstruction permitted if instability persisted after treatment). Healthcare resource use and health-related quality of life data (EuroQol five-dimension five-level health questionnaire) were collected in the trial at six, 12, and 18 months using self-reported questionnaires and medical records. Using intention-to-treat analysis, differences in costs, and quality-adjusted life years (QALYs) between treatment arms were estimated adjusting for baseline differences and following multiple imputation of missing data. The incremental cost-effectiveness ratio (ICER) was estimated as the difference in costs divided by the difference in QALYs between reconstruction and rehabilitation. Results. At 18 months, patients in the surgical reconstruction arm reported higher QALYs (0.052 (95% confidence interval (CI) -0.012 to 0.117); p = 0.177) and higher NHS costs (£1,017 (95% CI 557 to 1,476); p < 0.001) compared to rehabilitation. This resulted in an ICER of £19,346 per QALY with the probability of surgical reconstruction being cost-effective of 51% and 72% at a willingness-to-pay threshold of £20,000 and £30,000 per QALY, respectively. Conclusion. Surgical reconstruction as a management strategy for patients with long-standing ACL injury is more effective, but more expensive, at 18 months compared to rehabilitation management. In the UK setting, surgical reconstruction is cost-effective. Cite this article: Bone Joint J 2024;106-B(1):38–45

To investigate temporal changes in synovial lymphatic system (SLS) drainage function after Anterior cruciate ligament (ACL) injury, a non-invasive ACL rupture model was used to induce the PTOA phenotype without altering the SLS structure. We have created a non-invasive ACL rupture model in the right knee (single overload impact) of 12- week-old C57bl/6 male mice to mimic the ACL rupture-induced PTOA development. 70 kDa-TxRedDextran were injected into the right knee of the mice at 0, 1, 2, and 4 wks post modeling (n=5/group), and the fluorescence signal distribution and intensity were measured by the IVIS system at 1 and 6 hrs post-injection. After 24 hrs, the drainage lymph nodes and whole knee joint were harvested and subjected to ex vivo IVIS imaging and immunofluorescence detection respectively. Manual ACL rupture was induced by 12N overloaded force and validated by a front drawer test. Intraarticular clearance of TxRed-Dextran detected by the IVIS was significantly reduced at 1, and 2 wks at a level of 43% and 55% respectively but was not significantly different from baseline levels at 4 wks (89%). TxRed-Dextran signal in draining lymph nodes was significantly reduced at 1 week at the level of but not for 2 and 4 wks compared to baseline levels (week 1–29%, week 2–50%, week 4–94%). TxRed-Dextran particle was significantly enriched in the synovium at 1, 2 wks but was not significantly different from baseline levels at 4 wks rupture-post ACL rupture (Particle numbers: Sham Ctrl-34 ±14, week 1, 113 ± 17; week 2, 89 ± 13; week 4, 46 ± 18; mean ± SD). We observed the drainage function of SLS significantly decreased at 1 and 2 wks after the ACL rupture, and was slowly restored at 4 wks post-injury in a non-invasive ACL rupture model. Early impairment of SLS drainage function may lead to accumulation of inflammatory factors and promote PTOA progression

Introduction. Anterior Cruciate Ligament (ACL) injury prevention programs can reduce injury risk in various sports. The perception of ACL injury prevention programs amongst professional netball players and coaches has not been studied. The purpose of the study was to determine (1) level of awareness and experience of ACL injury prevention programs; (2) use of ACL injury prevention programs; and (3) barriers and potential facilitators to implementing a sustainable ACL injury prevention program in netball. Methods. This cross-sectional observational study was undertaken using the CHERRIES checklist. Female netball players representing Welsh senior and under-21 teams and elite and amateur coaches were invited electronically to participate in this web-based study between 1st May – 31st July 2021. Information on ACL injury susceptibility and seriousness, knowledge, experience, and implementation of ACL injury prevention programs were ascertained. Results. Twenty-eight players (77.8%) and 29 coaches (13.2%) completed the questionnaire. Seventeen (60.7%) players and 15 (51.7%) coaches reported female athletes were at greater risk for sustaining ACL injuries. Over 90% of respondents identified netball as high-risk, whilst 89% of players and 76% of coaches reported these injuries to be preventable. Only two (7.1%) players and 6 (20.7%) coaches utilised an ACL injury prevention program with lack of time and engagement from coaches and players identified. Majority of respondents indicated that their club has neither promoted, advocated the use nor demonstrated exercises for ACL injury prevention. Over 90% of respondents would utilise an ACL injury prevention program if it minimised players risk with appropriate information and demonstration of exercises. Conclusion. This study highlights limited knowledge of female athletes' increased susceptibility of ACL injuries amongst players and coaches with lack of communication and education of ACL injury prevention programs between sporting associations, coaches, and players. However, the results demonstrate willingness amongst both players and coaches to implement an ACL injury prevention program in netball

Anterior cruciate ligament (ACL) injuries have been increasing, especially amongst adolescents. These injuries can increase the risk for early-onset knee osteoarthritis (OA). The consequences of late-stage knee OA include structural joint change, functional limitations and persistent pain. Interleukin-6 (IL-6) is a pro-inflammatory biomarker reflecting knee joint healing, and increasing evidence suggests that IL-6 may play a critical role in the development of pathological pain. The purpose of this study was to determine the relationship between subjective knee joint pain and function, and synovial fluid concentrations of the pro-inflammatory cytokine IL-6, in adolescents undergoing anterior cruciate ligament reconstruction surgery. Seven youth (12-17 yrs.) undergoing anterior cruciate ligament (ACL) reconstruction surgery participated in this study. They completed the Pedi International Knee Documentation Committee (Pedi-IKDC) questionnaire on knee joint pain and function. At the time of their ACL reconstruction surgery, synovial fluid samples were collected through aspiration to dryness with a syringe without saline flushing. IL-6 levels in synovial fluid (sf) were measured using enzyme linked immunosorbent assay. Spearman's rho correlation coefficient was used to determine the correlation between IL-6 levels and scores from the Pedi-IKDC questionnaire. There was a statistically significant correlation between sfIL-6 levels and the Pedi-IKDC Symptoms score (-.929, p=0.003). The correlations between sfIL-6 and Pedi-IKDC activity score (.546, p = .234) and between sfIL-6 and total Pedi-IKDC score (-.536, p = .215) were not statistically significant. This is the first study to evaluate IL-6 as a biomarker of knee joint healing in an adolescent population, reported a very strong correlation (-.929, p=0.003) between IL-6 in knee joint synovial fluid and a subjective questionnaire on knee joint pain. These findings provide preliminary scientific evidence regarding the relationship between knee joint pain, as determined by a validated questionnaire and the inflammatory and healing status of the patient's knee. This study provides a basis and justification for future longitudinal research on biomarkers of knee joint healing in patients throughout their recovery and rehabilitation process. Incorporating physiological and psychosocial variables to current return-to-activity (RTA) criteria has the potential to improve decision making for adolescents following ACL reconstruction to reduce premature RTA thereby reducing the risk of re-injury and risk of early-onset knee OA in adolescents

Introduction. Anterior cruciate ligament (ACL) injuries are one of the most common knee injuries amongst elite athletes and usually require an ACL reconstruction (ACLR) to enable return to sport. Secondary surgery can result in a longer rehabilitation period and often a. significant time away from sport which can have implications to the athlete including contract obligations and sponsorship. Advances in ACLR techniques and meniscal repair techniques as well as an awareness of meniscal root lesions, ramp lesions and lateral extraarticular procedures (LEAPs) during ACL surgery has improved outcomes. The purpose of this study was to evaluate the rates of secondary surgery following the introduction of a systematic arthroscopic evaluation of the knee, improved meniscal repair techniques and the addition of a concomitant LEAP This systematic approach was introduced after October 2012 (10/2012). Methods. Professional athletes who underwent primary ACLR with a minimum follow-up of 2 years were identified from the (blinded for review). Those who had undergone major concomitant procedures such as multi-ligament reconstruction or osteotomy were excluded. Analysis of the database and review of medical records identified athletes who had underwent secondary surgery procedures. Results. A total of 342 athletes with a mean follow-up of 100.2 +/− 51.9 months (range, 24–215 months) were analysed. 130 athletes underwent surgery before 10/2012 and 212 athletes underwent surgery after 10/2012. Overall, 74 patients (21.6%) underwent secondary surgery. 39 patients (30.0% including 13.1% for graft rupture) before 10/2012 and 35 patients (16.5% including 6.6% for graft rupture) after 10/2012. A multivariate analysis was performed using the Cox model and demonstrated that athletes undergoing ACLR before10/2012 were at almost 2-fold risk of secondary surgery (hazard ratio (HR), 1.768(1.103;2.836), p=0.0256) when compared with those undergoing ACLR after 10/2012. (Figure 1). Conclusion. Professional athletes undergoing ACLR with a systematic arthroscopic evaluation with the use of advanced meniscal repair techniques and the combination with a LEAP result in a significantly lower rate of secondary surgery. For any figures or tables, please contact authors directly

Introduction. Anterior tibial translation (ATT) is assessed in the acutely injured knee to investigate for ligamentous injury and rotational laxity. Specifically, there is a growing recognition of the significance of anterior medial rotary laxity (AMRI) as a crucial element in assessing knee stability. Anterior cruciate ligament (ACL) injuries are often accompanied with medial collateral ligament (MCL) damage. It has been suggested that Deep MCL (dMCL) fibres are a primary restraint in rotational displacement. This research aims to quantify the difference in rotational laxity of patients with ACL and MCL injuries to deem if the Feagin-Thomas test can robustly capture metrics of AMRI. 2. Methods. AMRI was assessed using the Feagin-Thomas test in 7 isolated ACL (iACL) injured participants, 3 combined ACL and superficial fibre MCL (sMCL) injuries, 5 combined ACL and deep fibre MCL injuries, and 21 healthy controls. Displacement values were recorded using an optical motion capture (OMC) system and bespoke processing pipeline which map and model the knee's anterior displacement values relative to the medial compartment. Since absolute values (mm) of rotational laxity vary dependant on the person, values were recorded as a proportion of the rotational laxity obtained from the subject's contralateral leg. Values were compared between each patient group using an ANOVA test and Tukey's honesty significant difference post hoc test. 3. Results. The healthy control group had a median proportion of 0.97 (3SF), whilst the iACL was 1.12 (3SF), a 12% increase in rotational laxity in the injured leg. The sMCL group yielded a result of 1.64 (3SF), a 64% increase in rotational laxity in the injured leg; finally, dMCL resulted in a proportion of rotational laxity of 1.90 (3SF), a 90% increase in rotational laxity [table 1]. Whilst all groups showed differences in the increase of rotational laxity, dMCL was significantly different from the healthy control group (P value 0.0041). 4. Conclusion. ACL injuries with MCL involvement led to an increase in anterior medial rotary laxity and this is more evident in patients where deep MCL fibres are involved. The Feagin-Thomas test appears to be sensitive in detecting differences in AMRI and should be considered when performing comprehensive clinical knee examination. For any figures or tables, please contact authors directly

Rotational laxity increases the risk of anterior cruciate ligament (ACL) injuries and residual rotational laxity can result in inferior surgical outcomes and risk of retears. The dynamic rotatory knee stability can be assessed through manual examination, but it is limited to the surgeon's experience and it provides inaccurate measurements, highlighting the need for objective measurement of knee rotational laxity. The objective measurement of knee laxity can help to better identify patients that may benefit from conservative treatment or those that require surgical treatment with or without concomitant extra-articular procedures. We rely in Porto Knee Testing Device (PKTD®) to accurately measure sagittal and rotatory laxity of the knee, either individually or in a combined fashion. The PKTD® is safe and can be used in combination with CT or MRI, which allows to assess both the “anatomy” and the “function” in the same examination. By this way, we may have a total ACL rupture and a stable knee not requiring surgery or, on the other hand, the same injury scenario but with an unstable knee that requires surgical intervention (with or without lateral extra-articular tenodesis). In cases of partial ACL tears, it may be possible to identify some ligamentous fibers that remain functional, where the conservative treatment or augmentation techniques can provide satisfactory results. It can also identify when a posteromedial or posterolateral instability is associated. The PKTD® can also be used to follow-up the laxity results of conservative and surgical procedures and contribute to the decision-making of return to sports

Background: Anterior cruciate ligament (ACL) injury and re-injury rates are high and continue to rise in adolescents. After surgical reconstruction, less than 50% of patients return to their pre-injury level of physical activity. Clearance for return-to-play and rehabilitation progression typically requires assessment of performance during functional tests. Pain may impact this performance. However, the patient's level of pain is often overlooked during these assessments. Purpose: To investigate the level of pain during functional tests in adolescents with ACL injury. Fifty-nine adolescents with ACL injury (ACLi; female n=43; 15 ± 1 yrs; 167.6 ± 8.4 cm; 67.8 ± 19.9 kg) and sixty-nine uninjured (CON; female n=38; 14 ± 2 yrs; 165.0 ± 10.8 cm; 54.2 ± 11.5 kg) performed a series of functional tests. These tests included: maximum voluntary isometric contraction (MVIC) and isokinetic knee flexion-extension strength tests, single-limb hop tests, double-limb squats, countermovement jumps (CMJ), lunges, drop-vertical jumps (DVJ), and side-cuts. Pain was reported on a 5-point Likert scale, with 1 indicating no pain and 5 indicating extreme pain for the injured limb of the ACLi group and non-dominant limb for the CON group, after completion of each test. Chi-Square test was used to compare groups for the level of pain in each test. Analysis of the level of pain within and between groups was performed using descriptive statistics. The distribution of the level of pain was different between groups for all functional tests (p≤0.008), except for ankle plantar flexion and hip abduction MVICs (Table 1). The percentage of participants reporting pain was higher in the ACLi group in all tests compared to the CON group (Figure 1). Participants most often reported pain during the strength tests involving the knee joint, followed by the hop tests and dynamic tasks, respectively. More specifically, the knee extension MVIC was the test most frequently reported as painful (70% of the ACLi group), followed by the isokinetic knee flexion-extension test, with 65% of ACLi group. In addition, among all hop tests, pain was most often reported during the timed 6m hop (53% of ACLi), and, among all dynamic tasks, during the side-cut (40% of ACLi) test (Figure 1). Furthermore, the tests that led to the higher levels of pain (severe or extreme) were the cross-hop (9.8% of ACLi), CMJ (7.1% of ACLi), and the isokinetic knee flexion-extension test (11.5% of ACLi) (Table 1). Adolescents with and without ACL injury reported different levels of pain for all functional tasks, except for ankle and hip MVICs. The isokinetic knee flexion-extension test resulted in greater rates of severe or extreme pain and was also the test most frequently reported as painful. Functional tests that frequently cause pain or severe level of pain (e.g., timed 6m and cross hops, side-cut, knee flexion/extension MVICs and isokinetic tests) might not be the first test choices to assess function in patients after ACL injury/reconstruction. Reported pain during functional tests should be considered by clinicians and rehabilitation team members when evaluating a patient's readiness to return-to-play. For any figures or tables, please contact the authors directly

Introduction: Anterior cruciate ligament (ACL) injury is the first cause of knee instability. There is not enough evidence for the best therapeutic option, as operative and non-operative treatments of anterior cruciate ligament (ACL) injuries are often associated with a lack of proprioception and a persistent muscle weakness of unclear origin. Material and methods: This study in the cat experimentally compares in the long-term both neural and muscular activity in the knee articular nerves (PAN and MAN), quadriceps and hamstrings, in the chronic unstable knee and the reconstructed knee. Experimental section of ACL in twenty four cat’s knees was followed by stable reconstruction in six knees and unstable reconstruction in eight knees, leaving the other ten knees unstable without reconstruction. Electrical activity from muscles and nerves was registered with Ni-Cr electrodes. Mean firing activity and peristimulus time histograms (PSTH) for each structure were obtained. Secondly, it evaluates the neuromuscular response changes due to the graft’s mechanical competence, comparing stable and unstable reconstructed knees. Two different grafts were evaluated in the reconstructed knee, pediculated extensor digitorum longus and free bone-tendon-bone from patellar tendon. Statitiscal analysis consisted in Mann-Whitney’s test with Bonferroni adjustment between groups, and a two-way ANOVA to evaluate the separate effect of graft type and graft competence. Results: We found an increased periarticular muscle activity during anterior tibial translation in chronically unstable knees. Both reconstructed and non-reconstructed unstable knees lose the fast reactive activity in the articular nerves. When stability was recovered after reconstruction, knees showed a more adjusted, although incomplete, muscular reaction. No differences were observed among grafts, but their mechanic competence was determinant in the neuromuscular firing activity. Discussion: ACL injured knees in the cat, with or without reconstruction, display confirmed abnormalities in neuromuscular reaction in the long-term, while to regain stability with a competent graft in the reconstructed knee is crucial to lessen this anomalous reaction

Recent findings have identified the importance of previously undiagnosed or neglected meniscus lesions in association with anterior cruciate ligament (ACL) injuries (e.g. medial meniscus ramp lesions and posterior root tears of the lateral meniscus). There is increasing biomechanical evidence that they bear the potential to alter both anteroposterior and rotational laxity patterns in ACL injured knees. Few data exist with respect to the presence of these specific tear entities in large series of ACL injured patients. The purpose of the study was to analyze the meniscus tear pattern in a series of ACL injured knees with a special focus on ramp lesions of the medial meniscus and posterior root lesions of the lateral meniscus. The hypothesis was that a significant number of ACL injured patients would display these types of lesions. Data from 358 patients undergoing an ACL reconstruction (227 males /131 females, age: 28±10) were extracted from a center-based registry. The type of ACL tear (partial versus complete) as well as the presence of associated meniscus lesions were documented. Meniscus lesions were classified into the following categories: medial ramp lesions, lateral root lesions, medial ramp and lateral root lesion, other medial meniscus injuries, other lateral meniscus injuries, other bimeniscal injuries. Chi-square tests were used to determine whether the percentage of meniscal lesions differed between types of ACL tear, gender and age (below 21, 21–35, above 35). Significance was set at p < 0.05. Isolated ACL tears were present in 107 (30%) of the operated knees (31 partial; 327 complete). Complete ACL lesions were more likely to present an associated meniscus injury (321 out of 327, 71%) than partial tears (13 out of 31, 42%). The incidence of meniscus injuries which are associated with ACL tears is very high (70%). Previously undiagnosed or neglected meniscus injuries like medial ramp or lateral root tears could be identified in 35% of patients. As such, the hypothesis was confirmed that an important amount of ACL injured knees display this specific intraarticular soft tissue damage. A systematic evaluation of these lesions under arthroscopy should thus be performed and specific repair needs to be evaluated

It has been suggested that an increased posterior tibial slope (PTS) and a narrow notch width index (NWI) increase the risk of anterior cruciate ligament (ACL) injury. The aim of this study was to establish why there are conflicting reports on their significance. A total of fifty patients with a ruptured ACL and 50 patients with an intact ACL were included in the study. The group with ACL rupture had a statistically significantly increased PTS (p < 0.001) and a smaller NWI (p < 0.001) than the control group. When a high PTS and/or a narrow NWI were defined as risk factors for an ACL rupture, 80% of patients had at least one risk factor present; only 24% had both factors present. In both groups the PTS was negatively correlated to the NWI (correlation coefficient = -0.28, p = 0.0052). Using a univariate model, PTS and NWI appear to be correlated to rupture of the ACL. Using a logistic regression model, the PTS (p = 0.006) and the NWI (p < 0.0001) remain significant risk factors. From these results, either a steep PTS or a narrow NWI predisposes an individual to ACL injury. Future studies should consider these factors in combination rather than in isolation

Anterior cruciate ligament (ACL) injuries are one of the most common ligament injury occurring in young and active individuals. Reconstruction of the torn ligament is the current standard of care. Of the many factors which determine the surgical outcome, fixation of the graft in the bony tunnels has significant role. This study compared the clinical and functional outcome in patients who underwent ACL reconstruction by standard anteromedial portal technique with single bundle hamstring graft anchored in the femoral tunnel using rigidfix and cortical button with adjustable loops. The tibial fixation and rehabilitation protocol were same in both groups. 107 patients underwent ACL reconstruction over a two-year period (87 males, 20 females, 44 after motor vehicle accident, 34 after sports injuries, 79 isolated ACL tear, 21 associated medial meniscus tear, 16 lateral meniscus tear and 11 both menisci). Rigid fix group had 47 patients and adjustable loop 60 patients. Clinical evaluation at end of one year showed better stability in rigid fix group regarding Lachman, anterior drawer, pivot shift tests, KT 1000 arthrometer side to side difference and hop limb symmetry index. However, the differences were not statistically significant. Functional evaluation using IKDC 2000 subjective score and Lysholm score showed better results in rigidfix group than variable loop, but was not statistically significant. However, lower scores were noted in patients with concomitant meniscal injury than in isolated acl tear patients and this was statistically significant in both groups. Rigidfix seems to give better graft fixation on femoral side than variable loop, but by the end of one year the functional outcome is comparable in isolated acl reconstructions

Anterior cruciate ligament (ACL) injuries are frequent among athletes and a leading cause of time away from competition. Stability of the knee involves the ACL for limiting anterior tibial translation and the ALL (anterolateral ligament) to restrain internal rotation of the tibia. Present indications for treatment with a combined ACL-ALL reconstruction remain unclear and mostly subjective. We mathematically modeled the tibial plateau geometry to try and identify patients at risk of ACL injury, and develop an objective trigger point for the decision to proceed with additional surgery to optimize rotational stability in these higher risk patients. We hypothesized that an increased convexity and steepness of the posterior aspect of the lateral plateau would subject knees to higher rotational torques leading to potentially a higher risk of ACL injury. The study design was a case-control study involving ACL reconstruction cases (n=68) and matched controls (n=68) between 2008–2015 at our institution. We used a two-dimensional approach, evaluating sagittal MRI images of the knee to model the posterior convexity of the lateral tibial plateau. Points were selected along the articular surface, and a least-squares regression was used to curve-fit a power function (y = a xn). In the equation, larger coefficient a and n represented steeper slopes. The cases and controls were compared using a Mann-Whitney-U test, and the statistical significance was set at α < 0.05. A subgroup analysis for females and males was also performed for the curve-fit coefficients. We observed a significant difference in the tibial surface geometry between our ACL reconstruction cases and matched controls (Figure 1). The modeled power equation for our ACL cases had larger coefficients compared to controls for all groups. For all pooled subjects, coefficient a (ACL recon cases = 0.90 vs controls = 0.68, p < 0.0001) and coefficient n (ACL recon cases = 0.34 vs controls = 0.30, p = 0.07) (Table 1). For the statistically significant coefficient a, we found it had a sensitivity of 78.9% and specificity of 77.5% for the statistically significant coefficient a, we found it had a sensitivity of 78.9% and specificity of 77.5% for predicting injury, using a cut off coefficient of a = 0.78. The odds ratio was 12.6 [5.5 – 29]. The posterolateral cartilaginous slope of the tibial plateau was mathematically modeled in patients with ACL injury. Patients with ACL injury demonstrated abnormally steep and fast slopes compared to controls that may play predispose to ACL injury by increasing anterior translation forces and internal rotation torques sustained by their knee joint. A steeper slope may also explain high-grade pivot shifts on physical exam that are thought to be a relative indication for adding an associated ALL reconstruction. Our findings are promising for adding more objectivity to surgical decision-making, especially with identifying high-risk patients that may be candidates for combined ACL-ALL reconstructions. For any figures or tables, please contact the authors directly

Purpose. Injuries of the meniscal attachments can lead to meniscal extrusion. We hypothesized that the extent of lateral meniscal extrusion (LME) was associated with the severity of the lateral meniscus posterior root tear (LMPRT). This study aimed to evaluate the relationship between preoperative LME and arthroscopic findings of LMPRT in knees with anterior cruciate ligament (ACL) injury. Methods. Thirty-four knees that had LMPRTs with concomitant ACL injuries on arthroscopy were evaluated. Patients were divided into two groups, partial and complete root tears, via arthroscopic findings at the time of ACL reconstruction. We retrospectively measured preoperative LMEs using magnetic resonance imaging (MRI). Statistical analysis was performed using the Mann-Whitney U-test and Chi-square test. Results. Twenty-three knees had partial LMPRTs (type 1). Complete LMPRTs were observed in 11 knees (type 2, 2 knees; type 3, 2 knees; and type 4, 7 knees). In the partial LMPRT group, the average LME was 0.43±0.78 mm. In the complete LMPRT group, the average extrusion was 1.99±0.62 mm. A significant difference between these groups was observed in the preoperative LMEs (P<0.01). The receiver operating curve analysis identified an optimal cutoff point of 1.05 mm for the preoperative LME. This LME cutoff had a sensitivity of 100% and specificity of 85% for complete LMPRT. Conclusion. This study demonstrated that preoperative LMEs were larger in complete LMPRTs associated with ACL injuries than in partial LMPRTs. Our results suggest that preoperative MRI-detected LME may be a useful indicator for estimating LMPRT severity in knees with ACL injury

Recent reports have suggested an increase in the number of anterior cruciate ligament (ACL) injuries in children, although their true incidence is unknown. The prognosis of the ACL-deficient knee in young active individuals is poor because of secondary meniscal tears, persistent instability and early-onset osteoarthritis. The aim of surgical reconstruction is to provide stability while avoiding physeal injury. Techniques of reconstruction include transphyseal, extraphyseal or partial physeal sparing procedures. In this paper we review the management of ACL tears in skeletally immature patients. . Cite this article: Bone Joint J 2013;95-B:1562–9

Background. Non-contact anterior cruciate ligament (ACL) injuries occurs with a higher incidence in female athletes compared with males after the onset of puberty. One anatomical factor with clinically observable differences between males and females is lower extremity alignment. The knee joint valgus in the coronal plane, which is associated with ACL injury risk, is composed of rotation of the tibia around the stationary femur and hip rotation combined with knee flexion. The purpose of this study was to prove the difference of hip rotation between female and male handball players with or without history of ACL injury. Methods. Elite collegiate athletes on the varsity handball team (17 females and 24 males) were recruited. Whereas 8 females and 1 male had a history of ACL injury, there were 9 females and 23 males with no history of ACL injury. The 6 measures of hip joint motion [flexion, extension, abduction, adduction, external rotation (ER), and internal rotation (IR)] and the 2 measures of knee joint motion (flexion and extension) were measured with the standard procedure using a goniometer. Results. The range of ER in ACL-injured females (37±7.5) was smaller than in uninjured females (49±8.2). The range of IR in ACL-injured female players (55±9.6) was greater than in uninjured females (41±13). There was no difference in ER+IR between ACL-injured and uninjured females. In the ACL-injured male handball player, ER was dominant to IR. Compared with the uninjured males, the ACL-injured female players showed smaller range of ER, greater ranges of IR and greater ER+IR. Conclusions. ACL-injured female handball players had greater hip IR with smaller hip ER, compared with uninjured counterpart. Hip rotation may be a crucial risk factor for ACL injury in female athletes. Level of evidence. 2b

Injury to the anterolateral ligament (ALL) has been reported to contribute to high-grade anterolateral laxity following anterior cruciate ligament (ACL) injury. Failure to address ALL injury has been suggested as a cause of persistent rotational laxity following ACL reconstruction. However, lateral meniscus posterior root (LMPR) tears have also has been shown to cause increased internal rotation and anterior translation of the knee. Due to the anatomic relationship of the ALL and the lateral meniscus, we hypothesise that the ALL and lateral meniscus work synergistically, and that a tear to the LMPR will have the same effect on anterolateral laxity as an ALL tear in the ACL deficient knee. Sixteen fresh frozen cadaveric knee specimens were potted into a hip simulator(femur) and a six degree-of-freedom load cell (tibia). Two rigid optical trackers were inserted into the proximal femur and distal tibia, allowing for the motion of the tibia with respect to the femur to be tracked during biomechanical tests. A series of points on the femur and tibia were digitised to create bone coordinate systems that were used to calculate the kinematic variables. Biomechanical testing involved applying a 5Nm internal rotation moment to the tibia while the knee was in full extension and tested sequentially in the following three conditions: i) ACLintact; ii) Partial ACL injury (ACLam) – anteromedial bundle sectioned; iii) Full ACL injury (ACLfull). The specimens were then randomised to either have the ALL sectioned first (ALLsec) followed by the LMPRsec or vice versa. Internal rotation and anterior translation of the tibia with respect to the femur were calculated. A mixed two-way (serial sectioning by ALL section order) repeated measures ANOVA (alpha = 0.05). Compared to the ACLintact condition, internal rotation was found to be 1.78° (p=0.06), 3.74° (p=0.001), and 3.84° (p=0.001) greater following ACLfull, LMPRsec and ALLsec respectively. LMPRsec and the ALLsec resulted in approximately 20 of additional internal rotation (p=0.004 and p=0.01, respectively) compared with the ACL deficient knee (ACLfull). No difference was observed between the ALL and LMPR sectioned states, or whether the ALL was sectioned before or after the LMPR (p=0.160). A trend of increasing anterior translation was observed when the 5Nm internal rotation moment was applied up until the ACL was fully sectioned; however, these differences were not significant (p=0.070). The ALL and LMPR seem to have a synergistic relationship in aiding the ACL in controlling anterolateral rotational laxity. High-grade anterolateral laxity following ACL injury may be attributed to injuries of the ALL and/or the LMPR. We suggest that the lateral meniscus should be thought of as part of the anterolateral capsulomeniscal complex (i.e., LM, ITB, and ALL) that acts as a stabiliser of anterolateral rotation in conjunction with the ACL

Knee laxity following anterior cruciate ligament (ACL) injury is a complex phenomenon influenced by various biomechanical and anatomical factors. The contribution of soft tissue injuries – such as ligaments, menisci, and capsule – has been previously defined, but less is known about the effects of bony morphology. (Tanaka et al, KSSTA 2012) The pivot shift test is frequently employed in the clinical setting to assess the combined rotational and translational laxity of the ACL deficient knee. In order to standardise the maneuver and allow for reproducible interpretation, the quantitative pivot shift test was developed. (Hoshino et al, KSSTA 2013) The aim of this study is to employ the quantitative pivot shift test to determine the effects of bone morphology as determined by magnetic resonance imaging (MRI) on rotatory laxity of the ACL deficient knee. Fifty-three ACL injured patients scheduled for surgical reconstruction (36 males and 17 females; 26±10 years) were prospectively enrolled in the study. Preoperative magnetic resonance imaging (MRI) scans were reviewed by two blinded observers and the following parameters were measured: medial and lateral tibial slope, tibial plateau width, femoral condyle width, bicondylar width, and notch width. (Musahl et al. KSSTA 2012). Preoperatively and under anaesthesia, a quantitative pivot shift test was performed on each patient by a single experienced examiner. An image analysis technique was used to quantify the lateral compartment translation during the maneuver. Subjects were classified as “high laxity” or “low laxity” based upon the median value of lateral compartment translation. (Hoshino et al. KSSTA 2012) Independent t-tests and univariate logistic regression were used to investigate the relationship between the pivot shift grade and various features of bone morphology. Statistical significance was set at p<0.05. A high inter-rater reliability was observed in all MRI measurements of bone morphology (ICC=0.72–0.88). The median lateral compartment translation during quantitative pivot shift testing was 2.8mm. Twenty-nine subjects were classified as “low laxity” (2.8mm). The lateral tibial plateau slope was significantly increased in “high laxity” patients (9.3+/−3.4mm versus 6.1+/−3.7mm; p<0.05). No other significant difference in bone morphology was observed between the groups. This study employed an objective assessment tool – the quantitative pivot shift test – to assess the contribution of various features of bone morphology to rotatory laxity in the ACL deficient knee. Increased lateral tibial plateau slope was shown to be a significant independent predictor of high laxity. These findings could help guide treatment strategies in patients with high grade rotatory laxity. Further research into the role of tibial osteotomies in this sub-group is warranted

More than 250,000 people are suffering from Anterior Cruciate Ligament (ACL) related injuries each year in the US, with a cost of $17–25K/patient. There is an unmet clinical demand for improving grafts/scaffolds to provide biological integration in addition to mechanical support. Currently, no data is available for the utilization of fibrous scaffolds with bimodal distribution for ACL regeneration. The novelty in this study is that it proposes for the first time to investigate the collagen fibril diameter distribution in healthy and injured bovine ACL tissue, and utilization of such structure for scaffold design. Objectives are 1) developing a bovine ACL tear model and measuring the collagen fibril diameter distribution of both healthy and injured ACL tissues, and 2) fabricating scaffolds to mimic the structural properties of healthy and injured ACL tissue. Bovine ACL tissues (1–3 years old) were harvested and characterized for their fibril diameter distribution using Transmission Electron Microscopy (TEM) and biomechanical properties under tension. The electrospun polycaprolactone (PCL) scaffolds were characterized using SEM and mechanical testing. Healthy and injured ACL fibril diameter, and that of PCL scaffolds representing healthy and injured ACL are compared using unpaired student t-test. The proposed fibrous scaffold design represents a significant departure from the conventional unimodal approach, and is expected to have significant contribution to ACL regeneration. These discoveries will serve as the foundation for the development of biomimetic tissue engineering substrates aimed at promoting biological graft fixation

The main objective of the study was to determine the best method of treatment for adolescents with anterior cruciate ligament (ACL) injuries. Results were collected retrospectively from clinical notes from January 1999 to December 2001, during which time 14 patients were treated. Patient satisfaction, clinical examination and Cybex evaluation were used as criteria. A review of the literature on the subject was also conducted. The results at four to six-month follow-up showed that 85.6% of the patients returned to active sport participation at the same level, 100% had stable knees on clinical examination, and no patient had any leg-length discrepancy or rotational or angular malalignment. The ruptured ACL in young adolescents should be reconstructed to prevent re-injury and to decrease the incidence of traumatic degeneration in the unstable knee joint

Anterior cruciate ligament (ACL) injuries are being seen with increasing frequency in children. Treatment of the ACL deficient knee in skeletally immature patients is controversial. To determine the outcome of anatomic transphyseal ACL reconstruction in tanner stage 1 and 2 patients with open growth plates at a minimum of 2 years after surgery. Between 2007–2008, 16 prepubescent skeletally immature patients underwent anatomic transphyseal ACL reconstruction using soft tissue grafts. All patients were tanner stage 1 and 2 and all had open growth plates. Outcomes were assessed at a minimum of 2 years after surgery and included: limb alignment, limb length, instrumented testing with KT-1000 and International Knee Documentation Committee (IKDC) score. Mean age at the time of surgery was 12 years (8–14). Graft choices included: living-related donor hamstring tendon allograft (n=14), hamstring tendon autograft (n=1) and fresh frozen allograft (n=1). Mean IKDC subjective score was 96 (84–100). Sixty-two percent of patients had <3mm side-to-side difference on instrumented KT-1000 testing and 88% had a negative pivot shift. At 2 years after surgery, all patients had returned to strenuous activities and normal or nearly normal overall IKDC score was documented in 94% of patients. There were no cases of limb malalignment or growth arrest. We present a large series of anatomic transphyseal ACL reconstruction in tanner stage 1 and 2 patients with open growth plates at a minimum of 2 years following surgery. Excellent clinical outcomes were obtained with high levels of return to desired activities. Importantly, no growth disturbances were seen in this series of patients

Introduction. Aim of our study was to find an association of additional intra-artricular derangements due to the delay in referring a patient with Anterior Cruciate Ligament (ACL) injury to a consultant orthopaedic clinic. Methods and results. We carried out a retrospective review of 50 patients who underwent ACL reconstruction (performed arthroscopically taking semitendinosis tendon graft) between July 2007 and November 2008. Orthopaedic referrals were grouped into A&E-group (48%) and GP-group (52%). Average time span between initial injury and patient's first contact with an orthopaedic surgeon was 10 days in the AE-group and 30 months in the GP-group. On analysing the MRI scans we found a significant difference regarding the presence of additional injuries: A&E-group had less medial meniscus injuries (43.75%) compared to the GP-group (65%). Lateral meniscus injuries were present in 18.75% in A&E-group and in 35% in GP-group. Findings during arthroscopic ACL reconstruction revealed following differences: A&E-group had less medial meniscus injuries (30.43%) compared to the GP-group (46.15%). Lateral meniscus injuries were 43.48 % and 30.77 % in A&E-group and GP-group respectively. Lysholm Knee Scoring system was used in both the groups pre- and postoperatively. The A&E-group had better results preoperatively (average 56.7) and postoperatively (average 95.5) when compared to the GP group which had shown scores to be 50.4 (pre-op) and 90.7 (post-op). Conclusion. Delay in final diagnosis and treatment was much longer in the GP-group. There were higher incidences of meniscus injuries in the GP-group based on both MRI and arthroscopic findings. The outcome scores were better in the A&E-group. Our results do support the fact that it is essential to have an early referral, diagnosis and treatment of ACL injuries

Anterior Cruciate Ligament (ACL) injuries are increasing in prevalence amongst younger patients. Concerns exist as to the possibility of growth impairment due to transphyseal reconstruction techniques. However, due to the poor results of conservative treatment, reconstructive procedures have been employed to improve the outcome of these injuries. A growing body of evidence supports the safety of transphyseal reconstruction in older children. This study evaluates the safety and results of these techniques in younger patients. Between 1999 and 2006, 17 patients of Tanner stage 1 or 2 underwent unilateral transphyseal ACL ligament reconstruction, using ipsilateral, four-strand hamstring grafts. Patients were aged between 9.5–14.0 years (mean, 12.1 years), and were followed up for a minimum of two years and a mean of 44 months (range 25–100 months). Graft survival, functional outcome and complications were recorded. There was one graft failure after re-injury (6%). Of the remaining patients, all reported a good or excellent result and a normal IKDC score. Mean postoperative Lysholm score was 97.5 ± 2.6, mean Tegner activity scale was 8.1 ± 0.8 pre-injury, 4.2 ± 1.0 post-injury, and 7.9 ± 1.4 post-operatively. One patient had mild valgus deformity which caused no functional disturbance; otherwise examination was normal in all patients. There were no leg length discrepancies and KT1000 arthrometer measurements showed no significant difference between normal and operated legs. Based on the results of this series, transphyseal reconstruction appears to be a safe option for the treatment of anterior cruciate ligament injuries in the young child

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

Background. Following an anterior cruciate ligament (ACL) injury, the affected knee is known to experience bone loss and is at significant risk of becoming osteoporotic. Surgical reconstruction is performed to attempt to restore the function of the knee and theoretically restore this bone density loss. Cross-sectional analysis of the proximal tibia using peripheral quantitative computed tomography (pQCT) enables localised analysis of bone mineral density (BMD) changes. The aim of this study was to establish the pattern of bone density changes in the tibia pre- and post- ACL reconstruction using pQCT image analysis. Methods. Eight patients who underwent ACL reconstruction were included. A cross sectional analysis of the proximal tibia was performed using a pQCT scanner pre-operatively and one to two years post-operatively on both the injured and contralateral (control) knee. The proximal two and three percent slices [S2 and S3] along the tibia were acquired. These were exported to Matlab(tm) and automated segmentation was performed to remove the tibia from its surrounding structures. Cross correlation was applied to co-register pairs of images and patterns of change in BMD were mapped using a t-test (p<0.05). Connected components of pixels with significant change in BMD were created and used to assess the impact of ACL injury & reconstruction on the proximal tibial BMD. Results. Prior to surgical ACL reconstruction, the BMD in the injured leg was significantly reduced relative to the control leg [S2: p=0.002, S3: p=0.002]. Post surgery, the proximal tibial BMD did not change in either leg [Control S2: p=0.102, S3: p=0.181; Injured S2: p=0.093, S3: p=0.439]. The post surgical images demonstrated patterns of increasing BMD surrounding the tunnel in the form of compact bone. Discussion. A significant reduction in proximal tibial BMD was observed in the ACL injured legs relative to control legs. The pattern of pre-operative bone loss was generally observed to be global across the entire slice. No change in BMD was observed following ACL reconstruction, in either injured or control leg. These results indicate that proximal tibial BMD is reduced and does not change after ACL reconstruction

Knee trauma often causes meniscal injuries. Only 15% of all tears can be repaired. Partial or complete meniscectomy subsequently leads to an increased incidence of chondral damage and onset of early osteoarthritis. In Europe in 1999, 355 000 meniscal injuries were treated, 284 000 of which required partial or complete meniscectomy. As an alternative to allograft, the collagen meniscus implant (CMI®) can be used for reconstruction. A collagen matrix moulded in the form of a meniscus, this is trimmed to defect size and sutured into place arthroscopically. It then serves as a scaffold for cellular invasion. Indications are tears that require partial meniscectomy or an intact remnant stable meniscus. Cruciate ligament injuries, malalignment, osteoarthritis and stage-IV osteochondral defects are the principal contraindications. Between July 1998 and March 2000, 10 patients received a CMI in our department. Additional pathologies (four anterior cruciate ligament (ACL) injuries, four varus malalignments and five chondral defects) were treated simultaneously. The Lysholm score increased from 70 to 99 in patients treated with an additional high tibial osteotomy (HTO), from 58 to 91 in the group with ACL reconstruction, from 71 to 93 in patients with osteochondral autologous transplantation (OATS). The Lysholm score of the combined group (two patients with HTO and OATS, two with HTO and ACL reconstruction) improved from a preoperative 69 to 99 postoperatively. CMI, a biocompatible resorbable implant, induces cellular ingrowth and arthroscopic implantation. However, there are still questions to be answered. Few cases have been reported and no long-term studies have yet been published. It is not yet known whether osteochondral defects, unstable joints or malignment are limitations of using the implants

Purpose: Females are at greater risk for anterior cruciate ligament (ACL) injury than males. Soccer may be a significant risk factor for ACL injury in adolescent females. ACL injury has significant consequences, including early onset of osteoarthritis. The purpose of the study was to determine. the number of ACL reconstruction surgeries performed on females between the ages of 13–18 inclusive in the Capital Health (CH) region from December 2000 to November 2005, and. those due to soccer injuries. Secondly, we describe factors relating to the mechanism of injury. Method: Utilizing regional administrative data, we performed a standardized chart review and telephone interviews with female adolescents who underwent ACL reconstruction in the aforementioned time period. Information gathered included:. Age at reconstruction procedure. Indoor versus outdoor soccer playing surface. Level of play and frequency of participation. The Alberta Soccer Association provided the number of registrants in indoor and outdoor seasons over the same time period. Results: 2,824 ACL reconstruction operations were performed between December 2000 and November 2005. Reconstructions in females took place at an earlier age than in males. There were 266 ACL reconstructions in 256 adolescent females, of which 253 charts were available for review. One hundred and eleven (44%) knees were injured during soccer play. Seven patients with eight ACL reconstructions who injured their ACL playing soccer could not be located. ACL injuries occurred during indoor soccer in 52 (51%) cases despite higher registration in outdoor soccer during the same time-frame. 77 (74%) subjects played competitively and 81 (79%) subjects played two or more times/week. Conclusion: Approximately 10% of ACL reconstructions were performed on adolescent females. Nearly 50% of ACL injuries occurred during soccer play, with a similar number seen in indoor versus outdoor play. Study limitations include the use of administrative data to assess the number of ACL reconstructions rather than ACL injuries. An awareness of the propensity of knee injuries in female soccer players is important. With the increased participation of young females in soccer and the serious lifelong implications of ACL rupture, prevention and training should be improved to lower the incidence of injury

Introduction Roentgen stereophotogrammetric analysis (RSA) is the most accurate radiographic technique for measuring three-dimensional micromotion in joints, and is now being developed for the study of anterior cruciate ligament (ACL) injury and outcome after surgical reconstruction. Using RSA a prospective study of ACL reconstruction is being undertaken. The aim is to obtain accurate information on the performance of both bone-patellar tendon-bone (BPTB) and hamstring grafts post-operatively. Materials and methods 14 patients with a unilateral ACL tear who underwent ACL reconstruction have been studied prospectively. Seven had BPTB grafts, and seven had four-stranded semitendinosus/gracilis. Tantalum markers were inserted at the time of surgery, 4 each into the femur and tibia, and 8 into the graft, at regular intervals along the length. Stress stereo radiographs (90N anterior and posterior draw forces) were taken at 1, 6, 12 and 24 weeks post-operatively. They were analysed using Medis RSA software. Results Initial results suggest that in addition to measuring total anteroposterior knee laxity, detailed analysis of the graft itself is possible. Beads placed in the bone blocks of the BPTB grafts, and in the intraosseous ends of the hamstrings, enable calculation of slippage of the fixation. The BPTB bone plugs moved 0.6 to 1.2mm by 12 weeks, the Hamstrings fixation was more variable. Beads placed in the intraarticular graft may enable measurement of any post-operative stretching, but are also somewhat erratic. Identification of the site of stretching – around the tunnel entrances, or intraarticularly, should be possible. Conclusions We believe that this detailed application of RSA in analysing the performance of the two commonly used grafts in ACL reconstruction has not been previously described. We hope to gain valuable insight into the behaviour of both graft types and reasons for graft failure. This presentation will demonstrate the methods developed and include the technical difficulties encountered in this on-going study

In the last decades the number of anterior cruciate ligament (ACL) injury in skeletally immature patients (SIP) increased as a result of the participation in competitive sports at younger age and improved diagnostic tools allowing early diagnosis of ACL injury. Although the eminence avulsion fracture is more frequent in SIP and considered the ACL injury pediatric equivalent, intra-substance ACL injury in children is a growing problem. With torn ACL injured knee remains unstable. This instability is poorly tolerated in teens since it is difficult to limit their activity and leads to meniscal and chondral tears and causes resignation from sport carrier. Intraarticular transphyseal ACL reconstruction seems to be effective technique to restore knee stability despite potential iatrogenic complications such as epiphisiodesis, leg length discrepancy and axial malalignment. The main aim of this study was to evaluate the efficacy and results of this method and assess frequency of potential complications. Material: From 2006 to 2007 we performed 15 reconstructions (7 boys, 8 girls) of ACL in skeletally immature patients (Tanner 3). All patients were athletes. Average age of girls was 11,2 years and boys 12,3 years. The period from injury to reconstruction were shorter than 10 months. All patients were operated by the same surgeon using the same surgical technique – gracilis-semitendinosus autograft, with transphyseal tibial and femoral tunnels and extraarticular fixation with AO screws. Average tunnel diameter was 7 mm. All beside one ACL injuries were isolated, with 1 meniscus tear. Methods: In prospective study without control group patients were examined before reconstruction, and 6, 12, 24 months after surgery IKDC, Lysholm and Tegner score. We assessed the growth, leg length and axial disturbances by clinical and radiological assessment and the return to prior level of sport activity. Results: In 12 and 24 months follow-up no disturbance of angular and longitudinal growth were observed, 11/12 patients returned to previous sport activity after mean of 7 months post- op with scores: IKDC 96,5 after 12 months and 97 after 24 months, Lysholm 95 after 12 months and 96 after 24 months. Average gain of growth was 5,5cm/12 months on average. Conclusion: The use of complete transphyseal reconstruction is a safe, reliable technique in patients who have significant growth remaining, providing adequate knee stability, good satisfaction and allowing return to sport activity

Introduction and Aims: Anterior cruciate ligament (ACL) injuries have historically been classified as non-contact or contact based on the mechanism of injury. The purpose of this study was to establish a detailed correlation between mechanism and the associated osteochondral, meniscal and other injuries to improve understanding of this common injury and its outcome. Method: A descriptive analysis of prospectively collected data on ACL injuries requiring reconstruction between 2000 and 2004 was completed. Mechanism of injury was clearly elicited and correlated with clinical, radiologic and operative findings. Magnetic resonance imaging (MRI) was performed on all patients to analyse patterns of ACL rupture and associated osteochondral, meniscal and ligament injuries. Osteochondral injuries were analysed by a musculoskeletal radiologist according to location, intensity and depth. Intra-operative documentation of intra-articular injury pattern was also performed and correlated with MRI findings. Classification into ‘active’ (non-contact) and ‘passive’ (contact) mechanisms was completed and correlated with injury pattern. Results: Seventy patients were identified with appropriate clinical, radiologic and operative data. A thorough review of the events surrounding the injury was documented. Forty-six patients described an active mechanism and 24 patients a passive mechanism of injury. Clinical examination demonstrated a similar proportion of medial collateral ligament injuries in each group. MRI within three months of injury demonstrated occult osteochondral lesions or ‘bone bruises’ in the majority of patients. Clear distinguishing patterns of femoral and tibial osteochondral injury were identified in the active and passive groups. Depth of osteochondral injury was most commonly classified as at least two-thirds the distance to the physeal scar in both groups. Intensity of the abnormal edema-like signal in the marrow of the distal femur and proximal tibia was most commonly classified as severe in both groups. Lateral meniscus injury was more common than medial, and was found in the majority of patients, more commonly in the passive group. Conclusion: Although surgical techniques continue to improve, the ACL injury mechanism and its relation to intra-articular pathology is less well defined. This study defines either ‘active’ or ‘passive’ mechanisms, with implications for likely associated osteochondral and meniscal injury. This gives valuable insight into the ACL injured knee, its management, and eventual prognosis

Introduction In-vivo study by MRI has contributed to the understanding of knee kinematics for prosthetic design and the impact of knee pathology. The aim of this study was to compare the characteristics of knee motion exhibited by the tibio-femoral contact footprint and centre of the femoral posterior condyles over the tibial plateau during the flexion arc. Methods Twelve subjects (five males, ages 19 to 42 years) with a unilateral anterior cruciate ligament (ACL) injury performed a supine leg press against a 15 kg load. Sagittal MR images recorded the motion from 0° to 90° flexion of both knees. The tibio-femoral contact points and the position of the posterior condylar centres were measured against the reference of the tibial plateau, at 15° intervals, for both the healthy knee and the ACL injured knee. Results The tibio-femoral contact points in the healthy knee began anteriorly on the tibial plateau, and progressed posteriorly during the flexion arc. From 0° to 30° the footprints of the medial and lateral compartments are almost parallel. Onward from 30°, the lateral condyle moved further posteriorly than the medial condyle. In the ACL injured knee the footprint was more posterior on the tibial plateau, particularly on the lateral condyle, suggesting the axis of rotation of the knee had shifted medially due to ACL loss. The posterior condylar centres in the healthy knee were positioned over the centre of the tibial plateau in knee extension. The medial condylar centre remained central during the flexion arc, whereas the lateral condylar centre moved back over the tibial plateau. In the ACL injured knee the posterior condylar centres were more posterior than the healthy knees from 0° to 15°, but from 30° to 90° are not significantly different to the healthy knee. The difference in the position of the posterior condylar centres in the ACL injured knee between 0° and 15° indicates the effect of ACL deficiency on the governing axis of the knee in extension, as evidenced clinically by the pivot shift. Conclusions The tibio-femoral contact patterns describe events at the articular surface whereas posterior condylar centres reflect the movement of the axis of rotation at the knee; two characteristics of knee kinematics. The altered action of the ACL injured knee at the tibio-femoral interface has implications for the development of wear changes in the chronic ACL injured knee. In relation to the conduct of this study, one or more of the authors is in receipt of a research grant from a non-commercial source

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

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

The December 2022 Knee Roundup³⁶⁰ looks at: Effect of physical therapy versus arthroscopic partial meniscectomy: the ESCAPE trial at five years; Patellofemoral arthroplasty or total knee arthroplasty: a randomized controlled trial; Rehabilitation versus surgical reconstruction for anterior cruciate ligament injury; End-stage knee osteoarthritis in Australia: the effect of obesity; Do poor patient-reported outcome measures at six months relate to knee revision?; What is the cost of nonoperative interventions for knee osteoarthritis?

The April 2023 Children’s orthopaedics Roundup³⁶⁰ looks at: Can you treat type IIA supracondylar humerus fractures conservatively?; Bone bruising and anterior cruciate ligament injury in paediatrics; Participation and motor abilities after treatment with the Ponseti method; Does fellowship training help with paediatric supracondylar fractures?; Supracondylar elbow fracture management (Supra Man): a national trainee collaborative evaluation of practice; Magnetically controlled growing rods in early-onset scoliosis; Weightbearing restrictions and weight gain in children with Perthes’ disease?; Injuries and child abuse increase during the pandemic over 12,942 emergency admissions.

Aims

To fully quantify the effect of posterior tibial slope (PTS) angles on joint kinematics and contact mechanics of intact and anterior cruciate ligament-deficient (ACLD) knees during the gait cycle.

Aims

The effects of remnant preservation on the anterior cruciate ligament (ACL) and its relationship with the tendon graft remain unclear. We hypothesized that the co-culture of remnant cells and bone marrow stromal cells (BMSCs) decreases apoptosis and enhances the activity of the hamstring tendons and tenocytes, thus aiding ACL reconstruction.

We describe a new method for reconstructing the patellar tendon following combined injury to the patellar tendon and anterior cruciate ligament (ACL). Combined injuries to the patellar tendon and the ACL represent a rare and potentially serious injury pattern. The injury to the patellar tendon can often go undiagnosed at primary presentation. Reconstructive options for the patellar tendon are described but can be technically difficult, particularly if ipsilateral hamstring has been used for anterior cruciate ligament reconstruction. Evidence suggests combined injuries generally lead to poor long term outcome. We describe a case of a 26 year old male who presented with a reconstructed ACL and a patellar tendon deficient knee. Diagnosis was confirmed on Magnetic Resonance Imaging (MRI). Ipsilateral hamstrings had been used as donor for ACL reconstruction. An Achilles tendon allograft with distal bone block was used in combination with contralateral semitendinosus and gracilis autograft to reconstruct the three bundles of the patellar tendon. The patient experienced no postoperative complications and was followed up radiologically and clinically. Computer Topography imaging performed at 6 months post-operatively showed union of the bony Achilles tendon block. MRI performed 1 year post-operatively showed good incorporation of the tendinous grafts and no evidence of degeneration or tearing. Oxford knee score at 6 months post-operatively was 31/48. One year post-operatively full pre-injury activity level had been achieved. We believe this method to provide adequate strength and integrity, enabling early rehabilitation following this rare injury. It has also been shown to give a good functional outcome

Aims

The lack of disease-modifying treatments for osteoarthritis (OA) is linked to a shortage of suitable biomarkers. This study combines multi-molecule synovial fluid analysis with machine learning to produce an accurate diagnostic biomarker model for end-stage knee OA (esOA).