"S" Quattro external fixation for complex intra-articular thumb fractures.

PURPOSE To report outcomes in 10 patients who underwent dynamic "S" Quattro external fixation for complex fractures of the base of the thumb. METHODS Nine men and one woman aged 18 to 69 (mean, 31) years underwent "S" Quattro external fixation for complex fractures of the base of the thumb. The dominant hand was involved in 8 patients. Three patients had Bennett fractures, 5 had Rolando fractures, one had an open multi-fragmented fracture, and one had a fracture-subluxation. Four of them had had prior (failed) treatment with splints and/or Kirschner wires. The "S" Quattro external fixator was applied for a mean of 4.9 weeks. Patients were followed up in an out-patient setting for a mean of 10.7 months until bone union and removal of the external fixator. Finger flexor function was assessed based on total active movement (TAM). Functional outcomes were assessed using the Disability of Arm, Shoulder and Hand (DASH) questionnaire. RESULTS No pin-site infection, malunion, or non-union was encountered. Mean loss of TAM was 7.5 degrees. Five patients lost 10 degrees or more, 2 of whom lost 20 degrees (one with an open comminuted fracture and one was elderly). Four patients regained full TAM and 6 attained more than 75% TAM compared to the contralateral thumb. At the 3-year follow-up, the mean DASH score was 3.4. Four patients reported no functional disability. Poorer outcomes were reported in the 2 patients who once had lost 20 degrees of TAM. CONCLUSION The "S" Quattro external fixator is recommended as a primary and definitive treatment modality for complex intra-articular thumb fractures when conservative and other surgical interventions have failed.