Comparison of isokinetic strength recovery following ACL reconstruction among graft types

Although clinical and functional outcomes have been investigated following ACL reconstruction across graft types, few studies have examined serial measures of quadriceps and hamstring strength. This study compared isokinetic quadriceps and hamstrings muscle strength recovery among quadriceps tendon graft (QT), hamstring tendon graft (HT), bone-patellar tendon-bone graft (BPTB), and allograft ACLR procedures.

A retrospective review of patients aged 16-35 who underwent primary ACLR at a single sports medicine department was conducted. A total of 262 participants were included (HT = 134, QT = 67, BPTB = 27, allograft = 34). Isokinetic strength data were analyzed at 3, 6, 9, and 12 months postoperatively. Linear mixed models evaluated associations between graft type, time, and strength outcomes. Because groups differed with regards to age, sex, and concomitant meniscus procedures, these factors were included as covariates in each model.

Graft type was associated with quadriceps extension strength (p < 0.05 adjusted), while time by graft interaction was not. HT autografts and allografts demonstrated higher LSI extension values than QT and BPTB grafts. For hamstring flexion strength, HT grafts exhibited lower LSI values than other QT and BPTB grafts, suggesting donor-site deficits.

Quadriceps strength recovery differs by graft type following ACLR, with QT and BPTB grafts showing delayed recovery compared to HT and allografts whereas hamstring strength recovery appears to be more impaired following the use of HT grafts. These findings may inform graft-specific rehabilitation strategies for ACLR.