[Radiocarpal dislocation: twelve cases and a review of the literature]

Radiocarpal dislocation is an uncommon entity in traumatology. Proper management depends on the type of dislocation and the presence of concomitant injury. The purpose of this study was to detail the pathogenesis of radiocarpal dislocation and describe its complications and treatment.

Twelve radiocarpal dislocations were reviewed retrospectively. Nine were associated with multiple trauma. For this review, physical examination was performed to determine the functional status, presence of pain, joint motion, and grip force. The Green and O'Brien score as modified by Cooney was used to assess function. Grip force was measured with a Jamar dynamometer and weighted by the non-dominant/dominant ratio. Dumontier and Moneim classifications were used to define different types of radiocarpal dislocation. Radiological evaluation was based on anteroposterior (ulnar and radial inclination) and lateral views of the wrist.

Dorsal displacement was observed for nine dislocations. All were associated with fractures (eleven fractures of the lateral cuneal process and eight fractures of the styloid process). Other associated injuries were distal radioulnar dislocation and intracarpal sprains (two scapholunate and two lunotriquetral). There were three median nerve compressions which all regressed without sequelae. Ten patients were treated by styloradial osteosynthesis alone and two patients by capsule-ligament suture via an anterior approach. Pinning was used to stabilize the two lunotriquetral injuries and the one neglected radioulnar dislocation.

At last follow-up (mean 46.2 months), the overall functional outcome was satisfactory. The Green and O'Brien (modified by Cooney) score was excellent for one patient, fair for eight, and mediocre for three (75% satisfactory results). Distal radioulnar degeneration developed in the patient who had a neglected radioulnar dislocation. Three cases of radiocarpal degeneration were observed in patients with neglected scapholunate sprains whose wrist was symptomatic at last follow-up.

Radiocarpal dislocation is associated with intracarpal fracture and/or injury. Intracarpal injury must be treated in order to limit the risk of future degeneration. Pure radiocarpal dislocation (or in association with a minimal fracture of the styloid) should be treated surgically, irrespective of the approach, in order to achieve capsule-ligament suture. Other radiocarpal dislocations can be simply reduced with osteosynthesis of associated fractures. Intracarpal and/or distal radioulnar lesions must be stabilized. Osteosynthesis or capsule-ligament suture must be achieved to obtain a satisfactory clinical result.