Biomechanical Analysis of All-Inside, Arthroscopic Suture Repair Versus Extensor Retinaculum Capsulorrhaphy for Triangular Fibrocartilage Complex Tears with Instability

Purpose To assess ulnocarpal joint stability after treatment of a peripheral triangular fibrocartilage complex (TFCC) injury with all-inside arthroscopic suture repair (SR), extensor retinaculum capsulorrhaphy with the Herbert sling (HS), and a combination of both (SR+HS). Methods Twelve fresh-frozen, age-matched, upper-extremity specimens intact from the distal humerus were prepared. Nondestructive mechanical testing was performed to assess native ulnocarpal joint stability and load-displacement curves were recorded. A peripheral, ulnar-sided TFCC injury was created with arthroscopic assistance, and mechanical testing was performed. Each specimen was treated with SR or HS and testing was repeated. The 6 specimens treated with SR were then treated with HS (SR+HS), and testing was repeated. We used paired Student t tests for statistical analysis within cohorts. Results For all cohorts, there was an average increase in ulnar translation after the creation of a peripheral TFCC injury and an average decrease after repair. Herbert sling decreased translation by 21%, SR decreased translation by 12%, and SR+HS decreased translation by 26%. Conclusions Suture repair plus HS and HS reduce ulnar translation the most after a peripheral TFCC injury, followed by SR alone. Clinical relevance Ulnocarpal joint stability should be assessed clinically in patients with peripheral TFCC injury, and consideration should be made for using extensor capsulorrhaphy in isolation or as an adjunct to SR as a treatment option.