Analysis of prognostic factors in ring avulsion injuries

To report 105 cases of ring avulsion injuries, examine the factors affecting rate of survival and functional outcome after reconstruction, and evaluate whether these data provide enough evidence to support attempts to repair these injuries.

A retrospective cohort study was conducted in 105 patients with 105 ring avulsion injuries of all grades of severity treated at our center between 1977 and 2003. Factors that could affect the outcome included personal (gender, age, smoking history, vascular disease, diabetes mellitus, alcohol abuse), injury (finger affected, level of skeletal injury, presence of tendon and nerve injury, Urbaniak class as modified by Kay et al, presurgery time), and surgery features (number of arteries and veins reconstructed primarily and with vein grafts). Results were interpreted based on survival and final function. Function was measured by the presence of pain, range of motion, and 2-point discrimination.

Of the 86 digits with inadequate circulation, 11 digits had primary amputation. Reconstruction was attempted in 75 digits. Fourteen digits had secondary amputation because of revascularization failure. Failure was attributed to artery problems in 5 digits and to vein problems in 5 digits and was unknown in 4 digits. The overall survival rate was 81%.

Cigarette smoking is not associated with higher risk of revascularization failure. Reconstruction of 2 or more veins resulted in higher survival rates compared with reconstruction of only 1 vein. Level of bone injury is not an accurate indication of whether to attempt reconstruction. Primary nerve repair does not lead to a good sensory recovery in most digits. Patients who had their digits finally amputated had variable periods of hypersensitivity at the stump, which prolonged their convalescence time.