Arthroscopic Reduction Techniques for Complex Metacarpophalangeal Joint Dislocation With Sesamoid Bone Entrapment: A Case Series.

Purpose: Complex metacarpophalangeal joint (MCPJ) dislocations typically require open reduction, but there is a paucity of literature exploring arthroscopic-assisted reduction. We present our experience in six cases of arthroscopic reduction of complex MCPJ dislocation, evaluating the success rate and clinical outcomes and delineating key technical pearls and intraoperative challenges. Methods: This retrospective series included patients with complex dorsal MCPJ dislocation without fractures or open injuries who were treated at a single institution from 2004 to 2025. After closed reduction failed, arthroscopic reduction was attempted through dorsoradial and dorsoulnar portals. We evaluated the success rate and clinical outcomes and delineated key technical pearls and intraoperative challenges. Results: Among the six patients, injuries involved five thumbs and one little finger with the presence of intra-articular interposition of the sesamoid bones and volar plate. The arthroscopic success rate was 50%. Failed arthroscopic reduction was attributed to a shared triad: tightly incarcerated sesamoid bones, sports-related trauma, and occurrence during the initial years in the series. All patients had congruent MCPJs with good grip strength and stability subsequently. The majority of patients had no or only mild residual pain at 3 months. Conclusions: Arthroscopic reduction of complex MCPJ dislocation offers a safe, minimally invasive alternative to traditional open reduction for complex MCPJ dislocations. Type of study/level of evidence: Therapeutic IV.