Weight-Bearing Compared with Non-Weight-Bearing Following Osteochondral Autograft Transfer for Small Defects in Weight-Bearing Areas in the Femoral Articular Cartilage of the Knee

Background: Patients are routinely kept non-weight-bearing for four to eight weeks following osteochondral autograft transfer to repair cartilage defects of the medial and/or lateral femoral condyle. Therefore, the objective of this novel study was to investigate whether postoperative weight-bearing restrictions affect the outcomes of cartilage repair when an osteochondral autograft transfer system is used to repair small defects in weight-bearing areas of femoral articular cartilage. Methods: This a retrospective comparative study. Following review of the charts on 567 consecutive arthroscopic osteochondral autograft transfers, three homogeneous groups of patients with consecutive cases were identified: group A, cases of patients who were non-weight-bearing following the procedure (n = 68); group B, cases of those who were non-weight-bearing following the procedure with concomitant anterior cruciate ligament reconstruction (n = 29); and group C, cases of those who were weight-bearing as tolerated following the procedure (n = 437). The cases of patients whose knees underwent second-look (repeat) arthroscopy were stratified into two subgroups: non-weight-bearing (n = 20) and weight-bearing as tolerated (n = 42). Graft position and manifestation of a repair-adjacent defect (Outerbridge grade-III or IV cartilage defect that develops adjacent to the original osteochondral autograft transfer repair) were assessed during second-look arthroscopy. Cartilage repair was retrospectively assessed from second-look arthroscopy pictures by a blinded, independent orthopaedic surgeon with use of the International Cartilage Repair Society macroscopic cartilage-repair assessment tool. Postoperative complication rates were compared among the three primary groups. Results: The mean grafted area was 0.72 cm(2) (range, 0.16 to 1.45 cm(2)) and 0.73 cm(2) (range, 0.16 to 1.80 cm(2)) for the non-weight-bearing and weight-bearing-as-tolerated second-look subgroups, respectively. The mean International Cartilage Repair Society score was 11.12 and 11.25 points (near-normal cartilage) for the non-weight-bearing and weight-bearing- as-tolerated subgroups (p = 0.71) at a mean follow-up of 42.7 and 33.0 months, respectively. There was no significant difference in the duration of follow-up (p = 0.58), repair-adjacent defect prevalence (p = 0.94), or graft position (p = 0.99) between the two subgroups. Weight-bearing-as-tolerated patients (group C) experienced significantly fewer deep vein thrombosis and arthrofibrosis complications compared with non-weight-bearing patients (groups A and B) (p < 0.001). Conclusions: Postoperative weight-bearing restrictions did not affect mid-term cartilage repair outcomes in patients who underwent second-look arthroscopy when an osteochondral autograft transfer system was used to repair small defects in weight- bearing areas of cartilage of the medial and/or lateral femoral condyle.