Initial graft tension and the effect on postoperative patient functional outcomes in anterior cruciate ligament reconstruction

Purpose: The aim of this review was to investigate the effect of initial graft tension on patient-specific functional outcomes after anterior cruciate ligament reconstruction and determine whether a particular tension is associated with superior functional outcome. Methods: We performed a systematic review of prospective randomized trials with a National Health and Medical Research Council Australia level of evidence of III or higher published between 1950 and July 2012. Studies using a semitendinosus-gracilis or bone-patellar tendon-bone autograft that reported graft tension and postoperative functional outcomes were included. Quantitative analysis was performed on available data by calculating effect size (ES) both at various time points and across tensions (in Newtons). Results: Initial search strategies returned 457 original publications, of which 5 articles fulfilled all exclusion and inclusion criteria. The mean score for quality was 5.8 (SD, 1.3), with 12 being the highest possible score. When compared with the preoperative side-to-side difference in anterior tibial displacement, 80 N and 78.9 N of tension recorded the largest effect at 2 weeks or less (ES, -2.98 [range, -3.82 to -2.14]) and 12 months or more (ES, -2.45 [range, -3.40 to -1.51]) postoperatively, respectively. When we compared tensions, the largest effect was toward 80 N when compared with 20 N at 2 weeks or less after surgery (ES, 0.76 [range, 0.17 to 1.35]). Conclusions: The objective of this review was to systematically assess the literature to determine whether a particular initial graft tension results in superior outcomes after anterior cruciate ligament reconstruction. From the review, there is a trend toward an initial graft tension of 78.5 to 90 N resulting in a reduced side-to-side difference in anterior laxity. However, there is insufficient evidence to conclude whether patient-specific function is improved at any specific tension. Level of Evidence: Level II, systematic review of Level II studies.