Carpal Tunnel Syndrome after Xiaflex Injection for Dupuytren Disease
The patient was a healthy 63-year-old man who presented with recurrent right ring finger proximal interphalangeal joint contracture (67 degrees). He had prior Xiaflex treatment in the same digit 4 years previously. A repeated injection of Xiaflex (0.58 mg) between the metacarpophalangeal and proximal interphalangeal joint creases was performed by means of standard protocol. The following day, extension force was applied to rupture the cord and achieve a 47-degree improvement in proximal interphalangeal joint flexion. The patient’s subsequent recovery was uneventful with the exception that, at the 2-month visit, he complained of tingling and numbness in the radial three digits, along with nighttime awakenings. He was started on a wrist cock-up splint at night. At the 4-month visit, he noted weakness in his right hand and difficulty buttoning his shirt. Electromyography revealed abundant fibrillation potentials and positive sharp waves in the abductor pollicis brevis, with a severely decreased number of motor units but normal motor unit morphology. Nerve conduction velocity study demonstrated absent median sensory nerve response (Table 1). Motor response had very low amplitude and prolonged distal latency (Table 2). These findings were consistent with very severe, subacute median neuropathy at the wrist, and the patient ultimately underwent open carpal tunnel release. Two months postoperatively, he has already experienced significant relief of tingling and nighttime awakening. He still has some residual numbness, which is expected given the severity of his carpal tunnel syndrome. He continues to do well in terms of Dupuytren contracture and has maintained his improved ring finger range of motion.
To our knowledge, this is the first report of carpal tunnel syndrome following Xiaflex injection. It is unlikely that the collagenase mix itself led to carpal tunnel syndrome, as the injection was very distal to the carpal tunnel. We suspect the primary causative factor was the swelling, which is very common following Xiaflex injection.1,4 The patient may have had subclinical carpal tunnel syndrome and the swelling from the Xiaflex treatment pushed him to develop symptoms. Given the scenario, we have since raised the question of whether Dupuytren patients would benefit from carpal tunnel syndrome screening before Xiaflex injection. Electromyography/nerve conduction velocity studies may not be necessary, but a thorough history and physical examination are likely warranted. Even if asymptomatic, provocative maneuvers such as Phalen and Durkan tests may help identify patients at risk and appropriately direct treatment.