Return to play in paediatric & adolescent patients following anterior cruciate ligament reconstruction.

BACKGROUND: There is an increased risk of anterior cruciate ligament (ACL) rupture and subsequent ACL reconstruction in patients <18 years old due to their high levels of sporting participation. PURPOSE: The purpose of this study was to assess the rate and timing of return to play (RTP) in paediatric and adolescent patients following ACL reconstruction, and to compare the outcomes between those undergoing ACL reconstruction with bone patella tendon bone autograft (BTB) and hamstring tendon (HT) autograft. STUDY DESIGN: Level of Evidence: Level III; Retrospective Comparative Cohort Study. METHODS: The institutional ACL registry was screened for patients <18 that had undergone a primary ACL reconstruction. Outcomes were analysed for patients undergoing either a BTB or HT autograft for rate and timing of return to play, functional outcomes and subsequent knee injuries. Statistical analysis was performed using SPSS. RESULTS: 358 (BTB; 253, HT; 105) patients were followed up for 24-months (95% follow up). 86 athletes (27 BTB; 59 HT) were aged 13-15 years old with no significant difference in RTP rate or timing between graft types, however, there was a difference in ipsilateral re-ruptures (10.2% HT vs 0% BTB p = 0.03). 272 athletes (226 BTB; 46 HT) were aged 16-18 years old with no significant difference in RTP rate or timing between graft types, or ipsilateral re-ruptures (8.7% HT vs 2.7% BTB p = 0.07). Concurrent ligament, meniscal or chondral injuries found at the time was treated as necessary. CONCLUSION: Paediatric and adolescent patients undergoing ACL reconstruction with either BTB or HT had high rates of return to play. This was seen in both subgroups with 13-15-year-olds mostly receiving a HT graft repair and 16-18-year-olds mainly receiving a BTB repair. A moderate re-rupture rate was seen at 24-months. However longer follow up is needed to truly see the long-term impact of such an injury at such a young age.

The majority of athletes fail to return to play following anterior cruciate ligament reconstruction due to reasons other than the operated knee.

PURPOSE: The purpose of this study is to evaluate the reasons why athletes do not return to play (RTP) following anterior cruciate ligament (ACL) reconstruction from a large single-centre database. METHODS: The institutional ACL registry was screened for patients that had undergone a primary ACLR and had RTP status reported at 24-month follow-up. The reasons that patients were unable to RTP at 24 months were evaluated. The ACL-Return to Sport Index (ACL-RSI) was evaluated at baseline and 24-month follow-up to evaluate psychological ability to RTP. RESULTS: At 2 years, 1140 patients returned to play, and 222 had not returned to play. The most common reasons athletes were unable to return was fear of reinjury (27.5%), lack of confidence in performance on return (19.4%) and external life factors (16.6%), i.e. work commitments and family reasons. Other reasons for athletes not returning to play were residual knee pain (10%) and subsequent injury (5%). The ACL-RSI score was significantly lower at diagnosis (40.3 vs. 49.3; p = 0.003) and 2 years (41.8 vs. 78.7; p < 0.0001) in athletes who did not return to play vs. those that did RTP. CONCLUSION: The majority of patients that report they have not returned to play do so due to external life and psychological factors associated with their injury, including fear of reinjury and lack of confidence in performance. A small minority of patients were unable to return due to residual knee symptoms or reinjury. Pre-operative psychological assessment and intervention may identify those less likely to RTP and provide an opportunity for targeted interventions to further improve RTP outcomes. LEVEL OF EVIDENCE: III.

Posterior tibial bone bruising associated with posterior-medial meniscal tear in patients with acute anterior cruciate ligament injury.

PURPOSE: To evaluate whether medial-sided bone bruising was associated with postero-medial meniscal tears in patients with an acute rupture of their anterior cruciate ligament (ACL). METHODS: A retrospective analysis of 150 consecutive patients who had an MRI scan within 8 weeks of their ACL rupture that underwent an ACL reconstruction was performed. Based on the intra-operative findings, two groups were identified: Group A (N = 75) had no postero-medial meniscal tear associated with the acute ACL rupture and Group B (N = 75) had a postero-medial meniscal tear found at time of reconstruction. All patients' pre-operative MRI scans were reviewed for bone bruising in the following anatomic sites: lateral femoral condyle (LFC), lateral tibial plateau (LTP), medial femoral condyle (MFC), and medial tibial plateau (MTP). RESULTS: MTP bone bruising was found to be more prevalent in cases that had a postero-medial meniscal tear in the setting of an acute ACL injury (p = 0.046). MTP Grade 2 or 3 bone bruising was more common in patients that had a postero-medial meniscal tear (p = 0.046). There was a slightly higher incidence of grade 2 or 3 MTP bone bruising in cases with a postero-medial meniscal tear, although this did not reach statistical significance (n.s.) There was no difference in LFC, LTP or MFC bone bruising in patients with or without a postero-medial meniscal tear (n.s) for all. CONCLUSIONS: Medial-sided bone bruising; especially present on the posterior tibial plateau may result from a higher injury force during the injury to the ACL. The identification of medial bone bruising on pre-operative MRI imaging following an acute ACL rupture should raise the suspicion of an associated postero-medial meniscal tear. LEVEL OF EVIDENCE: III.

Regeneration of Osteochondral Defects Using Developmentally Inspired Cartilaginous Templates.

IMPACT STATEMENT: Successfully treating osteochondral defects involves regenerating both the damaged articular cartilage and the underlying subchondral bone, in addition to the complex interface that separates these tissues. In this study, we demonstrate that a cartilage template, engineered using bone marrow-derived mesenchymal stem cells, can enhance the regeneration of such defects and promote the development of a more mechanically functional repair tissue. We also use a computational mechanobiological model to understand how joint-specific environmental factors, specifically oxygen levels and tissue strains, regulate the conversion of the engineered template into cartilage and bone in vivo.

Mechanisms of ACL injury in professional rugby union: a systematic video analysis of 36 cases.

BACKGROUND: The mechanisms of ACL injury in rugby are not well defined. AIM: To describe the mechanisms of ACL injury in male professional rugby players using systematic video analysis. METHODS: 36 cases from games played in top professional leagues and international matches were analysed. 5 analysts independently assessed all videos to record the estimated frame/time of initial ground contact, frame/time of ACL tear and a range of play specific variables. This included contact versus non-contact ACL injuries, injury timing, joint flexion angles and foot contact with the ground. 37 side-stepping manoeuvres from a control game were analysed to allow comparison of non-injury versus injury situations. RESULTS: 57% of ACL injuries occurred in a contact manner. 2 main scenarios were identified: (1) offensive running and (2) being tackled, indicating that the ball carrier might be at higher risk of ACL injury. The majority of non-contact ACL injuries resulted from a side-stepping manoeuvre. In most non-contact cases, initial ground contact was through heel strike. Statistical assessment of heel strike at initial ground contact versus non-heel strike cases showed a significant difference in injury versus non-injury outcomes, with heel strike associated with higher injury risk. Non-contact ACL injuries had lower median knee flexion angles and a more dorsiflexed ankle when compared with a control group (10° vs 20°, p≤0.001 and 10° vs 0°, p=0.033 respectively). CONCLUSIONS: Over half of ACL injuries in rugby in our analysis resulted from a contact mechanism. For non-contact injuries, lower knee flexion angles and heel-first ground contact in a side-stepping manoeuvre were associated with ACL injury.

CRISPR-Based Editing Reveals Edge-Specific Effects in Biological Networks.

Unraveling the properties of biological networks is central to understanding both normal and disease cellular phenotypes. Networks consist of functional elements (nodes) that form a variety of diverse connections (edges), with each node being a hub for multiple edges. Herein, in contrast to node-centric network perturbation and analysis approaches, we present a high-throughput CRISPR-based methodology for delineating the role of network edges. Ablation of network edges using a library targeting 93 miRNA target sites in 71 genes reveals numerous edges that control, with variable importance, cellular growth and survival under stress. To compare the impact of removing nodes versus edges in a biological network, we dissect a specific p53-microRNA pathway. We show that removal of the miR-34a target site from the anti-apoptotic gene BCL2 desensitizes the cell to ectopic delivery of miR-34a in a p53-dependent manner. In summary, we demonstrate that network edges are critical to the function and stability of biological networks. Our results introduce a novel genetic screening opportunity via edge ablation and highlight a new dimension in biological network analysis.

Clinical Application of Scaffolds for Partial Meniscus Replacement.

Meniscal tears are common injuries often treated by partial meniscectomy. This may result in altered joint contact mechanics which in turn may lead to worsening symptoms and an increased risk of osteoarthritis. Meniscal scaffolds have been proposed as a treatment option aimed at reducing symptoms while also potentially reducing progression of degenerative change. There are 2 scaffolds available for clinical use at the present time; Collagen Meniscus Implant and Actifit. Medium-term to long-term data (4.9 to 11.3 y) demonstrate efficacy of partial meniscus replacement. The patients who seem to benefit most are chronic postmeniscectomy rather than acute meniscal injuries. Herein we report on available clinical data for Collagen Meniscus Implant and Actifit while describing our preferred surgical technique and postoperative rehabilitation program.

Total wrist arthroplasty using the Universal 2 prosthesis.

PURPOSE: To report outcomes of 21 total wrist arthroplasties (TWA) using the Universal 2 prosthesis. METHODS: Five men and 14 women aged 44 to 82 (mean, 62) years underwent 21 total wrist arthroplasties for rheumatoid arthritis (n=19) and post-traumatic arthritis (n=2) by a single surgeon using the Universal 2 prosthesis. Pre- and post-operative pain and function were assessed by a single surgeon using the Disabilities of the Arm, Shoulder and Hand (DASH) score and the patient-rated wrist evaluation (PRWE) score. Range of motion, stability, dislocation rate, and neurovascular status were also assessed. Radiographs were evaluated for implant alignment and fit, screw positioning, and implant loosening. RESULTS: The mean time to assessment of the range of motion was 3.1 (range, 1.8-3.9) years, and the mean time to assessment of the PRWE score was 4.8 (range, 2.1-7.3) years. The range of motion in each direction and the mean DASH and PRWE scores improved significantly following TWA. Two patients had restricted range of motion, which was treated by manipulation under anaesthetic (after 6 months in one and 8 weeks in the other). One patient underwent excision of a palmar bony bridge. One patient endured extensor pollicis longus rupture and underwent tendon transfer after 5 months. Radiographs revealed no evidence of implant loosening, migration, or malalignment. There was no sign of osteonecrosis in the remaining carpals or metacarpals. CONCLUSION: The Universal 2 TWA achieved significant improvement in range of motion and functional outcome of the wrist, with reduced rates of early joint instability, dislocation, and implant loosening, compared to previous implants. The small implant size and cementless design reduce bone loss and osteonecrosis.