Does synovialization after anterior cruciate ligament reconstruction have a positive effect on functional performance, outcomes scores, stability and muscle strength? A 2-year follow-up study after reconstruction

Background: To investigate the effect of synovialization of graft following anterior cruciate ligament reconstruction (ACLR) on functional performance test (FPT) and clinical outcomes.

Methods: Eighty-four male patients who underwent second-look arthroscopy at 2-year follow-up after unilateral ACLR using hamstring autograft were analyzed retrospectively. Patients were categorized by synovial coverage into A group (42 subjects, poor synovial coverage) and B group (42 subjects, good synovial coverage). FPT results, including those of single leg hop test (cm) of the involved limb, co-contraction test (s), shuttle run test (s), and carioca test (s), were compared between groups. Clinical scores, including Lysholm score, International Knee Documentation Committee (IKDC) subjective score, and Tegner activity score; stability assessments including Lachman test, Pivot-shift test, and side-to-side differences (cm) measured using a KT-2000 arthrometer were also compared between groups.

Results: Based on FPT results, no difference was evident between groups. Single leg hop test results were 144.3 ± 25.5 in A group and 145.4 ± 24.7 in B group (P = 0.849). Co-contraction test results were 17.1 ± 2.9 in A group and 16.9 ± 3.6 in B group (P = 0.827). Shuttle run test results were 9.3 ± 1.9 in A group and 9.3 ± 1.9 in B group (P = 0.935). Carioca test results were 11.4 ± 2.9 in A group and 10.5 ± 2.5 in B group (P = 0.149). Clinical scores and stability assessments did not differ between groups (P > 0.05).

Conclusions: Based on functional performance results, well-synovialized grafts did not yield better functional performance outcomes following ACLR compared to poorly synovialized grafts at 2-year follow-up. The same was true of clinical outcomes. Thus, the success of synovialization does not improve functional performance and clinical outcomes following ACL reconstruction in an all-male population.