Surgical anatomy of the first extensor compartment: A systematic review and comparison of normal cadavers vs. De Quervain syndrome patients

Purpose De Quervain syndrome or tenosynovitis is a common wrist pathology caused by stenosing tenosynovitis of the first dorsal compartment. Multiple studies have demonstrated significant anatomic variation within the first extensor compartment. Methods The terms “De Quervain's tenosynovitis” and “first extensor compartment anatomy” were comprehensively searched using the PubMed, MEDLINE, and Cochrane database. The presence of a septum within the first dorsal compartment, the number of APL (abductor pollicis longus), and EPB (extensor pollicis brevis) tendon slips were identified. Results A total of 574 articles were identified on initial search, of which 21 met inclusion criteria. There were 1901 normal cadaver specimens and 470 surgically treated De Quervain disease patients, whose data were available. A septum was present in 43.7% of normal cadavers versus 62.2% De Quervain patients with 58.5% (327 of 559) of the septi characterized as incomplete. There was a difference in the number of APL tendons with a single APL tendon slip noted in 18.3% of normal cadavers (200/1096) versus 27.2% of De Quervain patients (87/230). There was a difference in the number of EPB tendons between the normal cadavers and De Quervain's wrists with 2 or more EPB tendinous slips observed in 5.9% of normal cadavers compared with 2.9% of De Quervain patients. Conclusion Significant anatomic variability exists within the first extensor compartment. Patients with De Quervain disease were more likely to have a septum dividing the compartment and a single slip of APL. These variations are clinically relevant in the pathophysiology and treatment of De Quervain's tenosynovitis. Type of Study Prognostic studies. Level of Evidence Level III.