Parallel tunnel ligamentopexy-a novel technique for medial collateral ligament deficiency in primary total knee arthroplasty: a case study

Managing medial collateral ligament (MCL) deficiency in primary total knee arthroplasty (TKA) remains a challenge, often necessitating constrained implants or revision prostheses. We present an innovative technique, Parallel Tunnel Ligamentopexy, which stabilizes the MCL without requiring revision implants, thus preserving native structures and reducing bone loss. A 68-year-old male with severe varus deformity and grade 4 osteoarthritis of the left knee presented with progressive difficulty in ambulation and performing daily activities. Radiographic evaluation confirmed knee subluxation. The patient underwent left-sided TKA. Intraoperatively, a femoral attachment deficiency of the MCL was observed. Parallel tunnel ligamentopexy was performed by whip-stitching the residual MCL, creating two parallel 2-mm tunnels in the lateral distal femur, and securing the MCL using these tunnels. This approach was preferred over semitendinosus augmentation, given its reduced risk of supracondylar femoral fractures and improved suitability for osteoporotic bones. The patient was mobilized on postoperative day 1. The varus deformity was corrected, and knee stability was maintained. At six months follow-up, clinical and radiological evaluations demonstrated no signs of MCL laxity. The patient resumed daily activities independently, highlighting the efficacy of Parallel Tunnel Ligamentopexy in preserving knee stability without requiring a constrained implant. Parallel Tunnel Ligamentopexy is a cost-effective, biologically favorable solution for MCL deficiency in primary TKA. This technique avoids constrained implants, minimizes bone loss, and optimizes functional outcomes, particularly in osteoporotic patients.