L’incidence de la coalition du tunnel est plus élevée pour le tibia que pour le fémur après reconstruction du ligament croisé antérieur à double faisceau aux ischio-jambiers : une analyse systématique de la littérature

Introduction Intraoperative and postoperative coalition of tunnels may occur in double-bundle (DB) anterior cruciate ligament reconstruction (ACLR). However, the incidence and effect on clinical outcomes of tunnel coalition following primary DB ACLR using a hamstring autograft has yet be analyzed and thus remains unknown. The objective of this systematic review was to identify the incidence of tunnel coalition upon DB ACLR using hamstring autografts and to elucidate any clinical outcomes and/or complications that tunnel coalition may have postoperatively. Hypothesis The incidence of tunnel coalition would increase in respect to time from the index surgery and that tunnel coalition would be related to poorer clinical outcomes compared to non-coalition cases. Methods Three databases (PubMed, EMBASE, Cochrane Library) were searched in accordance with PRISMA and R-AMSTAR guidelines on June 15, 2020. Relevant studies were screened in duplicate and data regarding patient demographics, incidence of femoral and tibial tunnel coalition and outcomes were extracted. Coalition rate was also compared between follow up at 1 month or less defined as “shorter-term” and 6 months or greater as “longer-term”. Coalition is defined as the missing of a bony bridge between the two tunnels. Results Thirty-six studies examining 1574 patients, mean age 29.1 years, were included in this study. Twenty-nine studies (1110 knees) reported the incidence of femoral coalition with a pooled rate of coalition of 8% (95% CI=4%-12%). Twenty-eight studies (1129 knees) reported an incidence of tibial coalition with a pooled rate of coalition of 21% (95% CI=13%-30%). The incidence of tibial coalition was significantly higher than the incidence of femoral coalition across 21 comparative studies (OR=3.37, 95% CI=1.41-8.09, p =0.0065). Only two studies (111 knees) compared tunnel coalition and non-coalition groups for clinical outcome and no significant differences were observed with regards to Lysholm score, Tegner activity scale and knee laxity measured with a KT-1000 arthrometer. Discussion The rate of tibial tunnel coalition in DB ACLR is higher than femoral tunnel coalition, particularly at longer-term follow-up. Despite the higher radiographic evidence of coalition, the clinical effects of such remain to be ascertained and further comparative studies are required to facilitate this understanding. Level of evidence IV, systematic review.