Case series: Revision anterior cruciate ligament reconstructions using patellar tendon autografts

• Revision ACL reconstruction with BPTP autograft provides satisfactory results.
• Most important reason for graft failure was inappropriate positioning of the primary tunnels.
• Time from graft failure to revision and the cartilage status were factors important for successful results.

BackgroundUsing intra-operative findings and clinical results, including return to play (RTP) at the pre-injury level, this study investigated the causes of primary graft failure after revision anterior cruciate ligament (ACL) reconstruction with bone–patellar-tendon–bone (BPTB) autografts.MethodsA total of 54 patients were followed for a mean of 38.2 ± 10.2 months post-surgery. Subjective and objective results were evaluated using single assessment numeric evaluation (SANE) scores, Lachman tests, KT-2000 arthrometer results, and pivot-shift tests. The change in each patient's Tegner activity scale and RTP at the pre-injury level were also evaluated.ResultsInappropriate positioning of the tunnels was the most important reason (54%) for primary graft failure. After revision surgery, anterior knee stability was significantly improved (1.2 (mean) ± 1.2 (SD) mm vs 4.5 (mean) ± 1.9 (SD) mm; P < 0.01). Two (4%) patients sustained revision graft ruptures while two (4%) sustained contralateral knee ACL tears. The rate of RTP at the pre-injury level was 67% (36 patients), and mean SANE scores at the time of RTP were higher than before surgery (74.8 ± 13.8 points vs 24.1 ± 16.4; P < 0.001). The average time from primary graft failure to revision surgery was shorter (12.2 (mean) ± 4.0 (SD) vs 37.6 (mean) ± 8.8 (SD) months; P < 0.01) and the ratio of major cartilage injury was lower (39% vs 83%; P < 0.05) in the RTP group than that in the non-RTP group.ConclusionsThe time from primary graft failure to revision surgery and the extent of the cartilage injury are major factors in RTP after revision ACL reconstructions.