The Stener Lesion and Complete Ulnar Collateral Ligament Injuries of the Thumb A Review.

A Stener lesion is a complete tear of the ulnar collateral ligament (UCL) from the thumb proximal phalanx at the level of the metacarpophalangeal (MCP) joint that is displaced superficial to the adductor pollicis aponeurosis, leading to interposition of the aponeurosis between the UCL and the MCP joint. The interposition of the adductor aponeurosis distinguishes the Stener lesion from other UCL injuries and impedes healing, thereby necessitating surgery. A thorough clinical examination, including valgus stress testing of the MCP joint, is crucial to the diagnosis. In cases where the clinical evaluation is equivocal, imaging studies including ultrasound or magnetic resonance can be performed. Acute Stener lesions can be treated with repair of the UCL primarily through direct suture, suture anchor, or pull-out suture techniques. Chronic injuries are treated with dynamic (via tendon transfer) or static (via grafting) reconstruction methods, while MCP arthrodesis or arthroplasty can be reserved for cases where MCP joint osteoarthritis is present. Overall, patient outcomes are generally good with operative treatment of Stener lesions. This article reviews the relevant anatomy and pathogenesis, clinical evaluation, diagnostic studies, management, outcomes, complications, and an illustrative case of Stener lesions and complete UCL injuries of the thumb.