Anatomic location of the first dorsal extensor compartment for surgical De-Quervain's tenosynovitis release: A cadaveric study.

ABSTRACT

BACKGROUND: De-Quervain's tenosynovitis is a disorder arising from the compression and irritation of the first dorsal extensor compartment of the wrist. Patients who fail conservative treatment modalities are candidates for surgical release. However, risks with surgery include damage to the superficial radial nerve and an incomplete release due to inadequate dissection. Currently, there is a paucity of literature demonstrating the exact anatomic location of the first dorsal extensor compartment in reference to surface anatomy. Thus, this cadaveric study was performed to determine the exact location of the first extensor compartment and to devise a reliable surgical incision to prevent complications. AIM: To describe the location of the first dorsal compartment in relation to bony surface landmarks to create replicable surgical incisions. METHODS: Six cadaveric forearms, including four left and two right forearm specimens were dissected. Dissections were performed by a single fellowship trained upper extremity orthopaedic surgeon. Distance of the first dorsal compartment from landmarks such as Lister's tubercle, the wrist crease, and the radial styloid were calculated. Other variables studied included the presence of the superficial radial nerve overlying the first dorsal compartment, additional compartment sub-sheaths, number of abductor pollicis longus (APL) tendon slips, and the presence of a pseudo-retinaculum. RESULTS: Distance from the radial most aspect of the wrist crease to the extensor retinaculum was 5.14 mm ± 0.80 mm. The distance from Lister's tubercle to the distal aspect of the extensor retinaculum was 13.37 mm ± 2.94 mm. Lister's tubercle to the start of the first dorsal compartment was 18.43 mm ± 2.01 mm. The radial styloid to the initial aspect of the extensor retinaculum measured 2.98 mm ± 0.99 mm. The retinaculum length longitudinally on average was 26.82 mm ± 3.34 mm. Four cadaveric forearms had separate extensor pollicis brevis compartments. The average number of APL tendon slips was three. A pseudo-retinaculum was present in four cadavers. Two cadavers had a superficial radial nerve that crossed over the first dorsal compartment and retinaculum proximally (7.03 mm and 13.36 mm). CONCLUSION: An incision that measures 3 mm proximal from the radial styloid, 2 cm radial from Lister's tubercle, and 5 mm proximal from the radial wrist crease will safely place surgeons at the first dorsal compartment.