Arthroscopic wrist capsulotomy

Pathomechanics

Arthrofibrosis is due to an excessive fibrotic response following a prolonged inflammatory condition or a traumatic wrist injury or surgery, and it can lead to a progressive loss of joint motion. Wrist contractures can occur following any type of wrist injury, but are most prevalent following distal radius fractures (DRFs). Ganglion excision, carpal dislocation or fracture, previous wrist surgery, reflex sympathetic dystrophy, and prolonged immobilization may all lead to a loss of wrist motion.

Physical examination

A biomechanical study performed by Palmer et al. defined functional wrist motion as 5 degrees of flexion, 30 degrees of extension, 15 degrees of radial deviation, and 10 degrees of ulnar deviation. AP and lateral wrist radiographs are taken to assess the articular surfaces and rule out a carpal nonunion or instability. A CT scan can be used to identify any articular step-off or gaps. An MRI may be helpful to assess the intercarpal ligament injury or carpal avascular necrosis (AVN).

Indications

Patients lacking a functional arc of wrist motion for 6 months or more and have failed a trial of dynamic/static progressive splinting are candidates for arthroscopic capsulotomies. Volar capsulotomies are less risky and are indicated to regain wrist extension. Dorsal capsulotomies are necessary to regain wrist flexion but they may require use of a volar arthroscopy portal and are technically more difficult.

Contraindications

General contraindications to wrist arthroscopy including active infection; bleeding disorders; neurovascular compromise; marked swelling, which distorts the anatomy; inadequate or marginal soft tissue coverage of the wrist; and inability to withstand anesthesia. A frank volar carpal or dorsal carpal instability pattern is a contraindication because release of the volar and/or dorsal extrinsic ligaments would likely exacerbate this condition. Similarly, the presence of posttraumatic arthritis or osteoarthritis will limit any potential gains. Division of the radioscaphocapitate (RSC), long radiolunate (LRL), and short radiolunate (SRL) ligaments should be performed with caution in patients who are at risk for ulnar translocation, such as those patients with rheumatoid arthritis and those who have undergone previous radial styloidectomies.

Relative contraindications include unfamiliarity with the regional anatomy and abnormal bony anatomy due to a distal radius malunion. Patients who cannot comply with postoperative dynamic/static progressive splinting due to low pain threshold or psychological disorder are not appropriate candidates.