Low rate of growth disturbance after posterior cruciate ligament reconstruction or repair in skeletally immature patients: a systematic review

Importance: The management of posterior cruciate ligament (PCL) injuries in children is complex and varies depending on the specific nature of the injury. Avulsions of the PCL can often be addressed with proximal or distal repair, while intra-substance tears and cases with persistent instability generally require more extensive reconstruction. Despite the prevalence of such cases, the literature is predominantly composed of case reports, indicating a lack of comprehensive research in this area. Aim: The purpose of this systematic review was to analyze growth disturbance in skeletally immature patients after PCL reconstruction or repair. Evidence review: A systematic review was conducted on the basis of the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. The following search terms were used in the title, abstract, and keyword fields: "PCL" or "posterior cruciate ligament" AND "children" or "open physis" or "immature". The main outcome data extracted from the studies was to assess growth disturbance at a minimum 1-year follow-up after surgery. Results: A total of 34 patients, from 17 articles, were included of which 30 (88.24%) male and 4 (11.76%) female. Mean age at surgery was 10.18 ± 2.88 years. The mean interval from injury to surgery was 178.9 ± 288.04 days. Average follow-up duration was 50.64 ±22.69 months. Six studies reported on PCL reconstructions using various grafts, including autologous allografts (hamstring or tibialis anterioris), Achilles tendon allografts with bone plugs, and parental donated hamstrings allografts. Only one study reported the use of internal brace to repair PCL, while in all the other studies was performed a repair of the PCL with fixation of the bone fragment (to the femur or tibia) with screws or suture. Growth disturbances (≥ 10mm) were reported in 2 of the 13 (15.38%) patients underwent PCL, while in PCL repair was noted in 2 of the 21 patients (9.52%) (p=0.63). Only 1 patients belonging to PCL reconstruction reported a slight increase in the valgus alignment of the operated knee compared to the contralateral knee, representing medial overgrowth at the distal femur (p=0.33). Conclusions: There is scarce literature on the risk of growth disturbance in skeletally immature patients after PCL reconstruction or repair. Nevertheless, posterior cruciate ligament reconstruction in children indicate a low risk of growth disturbance, in particular for length leg discrepancy (<15%) in the mid-long term follow-up, and a low rate of angular deviations (<8%). This surgery remains a major challenge for orthopaedic surgeons, and many unknowns remain regarding ideal grafts, technique, and time for surgery to prevent growth disturbance. Level of evidence: Systematic review of Level IV.