Perilunate dislocation and fracture dislocation of the wrist: outcomes and long-term prognostic factors.

INTRODUCTION: Perilunate dislocations and fracture-dislocations are severe injuries that often have serious functional sequelae. Our goal was to evaluate the long-term clinical and radiological results of these perilunate injuries, and to look for prognostic factors of a poor clinical outcome.

HYPOTHESIS: All patients who suffered perilunate injuries in their wrist have functional sequelae and long-term radiographic changes despite optimal treatment with anatomical surgical reduction.

MATERIALS AND METHODS: We did a single-center, retrospective study of 32 patients who had either an isolated perilunate dislocation (n=7) or fracture-dislocation (n=25) in their wrist. Pain, range of motion, strength and functional scores (MWS, PRWE, QuickDASH) were evaluated. Radiographs were analyzed to look for signs of osteoarthritis or carpal instability.

RESULTS: The mean follow-up time was 9.9 years (3.5-24). The wrist joint had a mean flexion-extension of 86° (0-140), radioulnar deviation of 38° (0-65) and pronosupination of 153° (120-180). The mean grip strength was 35 kg (5-56). The mean MWS, PRWE and QuickDASH scores were 65/100, 32/100 and 29/100, respectively. At the final assessment, 23 patients (79%) had radiographic signs of osteoarthritis while 5 patients (16%) had residual carpal instability. Three patients subsequently underwent palliative treatment. Opening the carpal tunnel and the magnitude of the lunate's displacement are significant predictors of a poor long-term functional outcome (p < 0.05). Older age at the time of injury was a predictor for the development of osteoarthritis.

DISCUSSION: Despite optimal treatment, perilunate dislocations and fracture-dislocations at the wrist cause functional sequelae such as pain, stiffness, strength deficit and post-traumatic arthritis in nearly 80% of patients. The functional outcomes are determined by the amount of lunate displacement (stage) and the patient's age. We do not recommend opening the carpal tunnel, even when signs of median nerve compression are present; reducing the dislocation helps to relieve the neurological symptoms.

LEVEL OF EVIDENCE: IV; retrospective observational study.