Hook of the Hamate Pathologies and Associated Flexor Tendon Ruptures

Abstract

Objective: Hook of the hamate pathology is an uncommon cause of spontaneous flexor tendon rupture. The purpose of this paper is to review the varying hamate pathologies leading to flexor tendon rupture, the incidence of each flexor tendon rupture, and the reported treatment options and outcomes of flexor tendon ruptures secondary to hook of the hamate pathology. Methods: A literature review was conducted using PubMed and Medline databases to obtain data on spontaneous flexor tendon ruptures associated with varying pathologies of the hook of the hamate. The search strategy included published articles in English with the terms “hamate” and “tendon rupture.” Combined searches yielded 42 abstracts. All papers were reviewed and evaluated. Twenty-four described flexor tendon rupture associated with hamate pathology. Studies were excluded if ruptures were not associated with hamate pathology confirmed intra-operatively. Results: Twenty-four manuscripts were identified that described the treatment of 66 patients with flexor tendon rupture secondary to hamate pathology. The small finger profundus tendon was ruptured in all 66 patients. Other tendon ruptures included: 32 small finger superficialis tendons (48%), 24 ring finger profundus tendons (36%), 9 ring finger superficialis tendons (14%), and 2 long finger profundus tendons (3%). 31 (46%) of the ruptures were associated with underlying hook of the hamate arthritis, 21 (32%) with hook of the hamate non-union, 9 (14%) with acute hook of the hamate fracture, and 5 with varying rare etiologies. Profundus ruptures were treated with either interpositional tendon grafting (52%), side-to-side profundus tenodesis (45%), or tendon lengthening with primary repair (3%). All tendon repairs were combined with hook of the hamate excision. All but one patient was reported to return to pre-injury activities following operative intervention. Conclusion: Hook of the hamate arthritis, fracture, and non-union are possible etiologies of spontaneous flexor tendon rupture and can cause significant morbidity if not recognized. Flexor tendon rupture secondary to hook of the hamate pathology appears to occur in a predictable fashion; small finger profundus → small finger superficialis → ring finger profundus → ring finger superficialis → long finger profundus. When healthy ruptured tendon ends can be identified, interpositional tendon grafting is an acceptable treatment option to treat flexor tendon ruptures secondary to hook of the hamate pathology. Otherwise, side-to-side profundus tenodesis provides sufficient repair for patients to return to pre-injury activities. Corresponding Author: Mitchell Gauger, [email protected], (574)-253-3321