Impact of Suture Configurations for Posterior Horn Meniscal Repair on Postoperative Stability and Reoperation Rates in Patients Undergoing Concurrent Anterior Cruciate Ligament Reconstruction: A Retrospective Comparative Study

Background Posterior horn meniscal tears often accompany ACL injuries, requiring surgical repair to preserve knee function and prevent osteoarthritis. The optimal suture configuration remains debated. Objective To compare the impact of vertical mattress, horizontal mattress, and combined sutures for posterior horn meniscal repair on knee stability and reoperation rates in patients undergoing concurrent ACL reconstruction. Methods This retrospective study analyzed 186 patients (January 2022–December 2024) who underwent arthroscopic meniscal repair with ACL reconstruction. Patients were grouped by suture technique: vertical mattress (n = 64), horizontal mattress (n = 58), or combined (n = 64). Tear length, injury-to-surgery interval as a surrogate of tear chronicity, tear zone, and tear pattern (simple longitudinal vs bucket-handle) were extracted from operative and preoperative records and incorporated into adjusted survival analyses. Outcomes assessed at minimum 24-month follow-up included IKDC score, Lysholm score, Tegner scale, KT-1000 arthrometer measurements, reoperation rates, and Kaplan–Meier failure-free survival. Results The combined suture group achieved significantly higher IKDC scores (87.6 ± 8.4) than the vertical (82.4 ± 9.2) and horizontal groups (79.8 ± 10.6) (P < 0.01). KT-1000 side-to-side differences were significantly lower (better stability) in the combined group (1.8 ± 0.9 mm) versus the horizontal group (2.6 ± 1.2 mm) (P < 0.05). The overall meniscal repair failure rate was 11.8% (22/186), differing significantly among groups: horizontal 17.2%, vertical 10.9%, combined 7.8% (P = 0.024). Kaplan–Meier analysis demonstrated significant between-group differences in failure-free survival, with estimated 24-month survival of 92.2% in the combined group, 89.1% in the vertical group, and 82.8% in the horizontal group (overall log-rank P = 0.024). Horizontal suture configuration (HR 2.84, 95% CI 1.32–6.14; P = 0.008) and medial meniscus location (HR 2.42, 95% CI 1.18–4.96; P = 0.014) were independent risk factors for failure, whereas tear length, chronicity, and bucket-handle tear pattern were not independently associated after adjustment. Conclusions Combined vertical-horizontal suture repair for posterior horn meniscal tears during ACL reconstruction was associated with superior clinical outcomes, better knee stability, and lower reoperation rates compared with single-plane techniques. Given the retrospective non-randomized design, combined sutures should be considered rather than routinely mandated.