Technique Spotlight: Interosseous Membrane Reconstruction

Indications

The primary indication to reconstruct the interosseous membrane (IOM) is a longitudinal radioulnar dissociation also known as an Essex-Lopresti injury (ELI). An ELI is an injury triad involving fracture of the radial head, rupture of the interosseous ligaments, and instability of the distal radioulnar joint (DRUJ). Early diagnosis is paramount for a favorable outcome, as timing affects the strategy of treatment.

In the acute setting, the surgeon will repair or replace the radial head, repair the triangular fibrocartilage complex (TFCC), and stabilize the interosseous interval with a tendon graft or a suture-button device. Acutely diagnosed injuries with proper stabilization may yield a good result in 80% of cases. However, unrecognized injury and poor stabilization lead to an 80% failure rate. ^,

In the chronic setting, the radius has migrated proximally, and the IOM has no potential for healing. Radiocapitellar impingement and instability at the DRUJ are often identified. To address the pathology at the elbow, the radial head may be excised as long as axial stability has been reestablished, or it may be replaced with implant arthroplasty. Proximal radial migration also causes a relative shortening at the DRUJ with symptomatic ulnar impaction. Wrist arthroscopy is valuable to evaluate the lunate articular cartilage and the TFCC. Then, ulnar shortening osteotomy is utilized to correct the ulnar variance at the wrist. Finally, IOM reconstruction of the central band imparts additional stability to the forearm for force transmission and prevents further radial migration.

Preoperative Evaluation

A thorough history should focus on the mechanism of action and location of pain. An axial load injury should clue the physician to evaluate not only the elbow, but also the forearm and wrist. The elbow flexion-extension arc, as well as varus/valgus stability, should be scrutinized for a deficit compared to the contralateral extremity. Similarly, the wrist is examined to identify signs of ulna impaction. Examination should include evaluation for TFCC mechanical symptoms, foveal tenderness, and lunotriquetral (LT) ballottement. The DRUJ is assessed in both supination and pronation to identify loss of motion or joint laxity.

Imaging of both the elbow and wrist should be obtained. Grip-loaded view or axial loading under fluoroscopy can be acquired to look for dynamic instability at the wrist. Greater than 6 mm of proximal migration is indicative of forearm dissociation. In the acute setting, advanced imaging can be used to assess the IOM. Magnetic resonance imaging (MRI) has been shown to identify IOM disruption; herniation of musculature through the IOM is pathognomonic. However, edematous or attenuated ligaments may be difficult to correlate with clinical stability. Ultrasound has also been used acutely albeit less commonly than MRI.