Variable pitch headless compression screw treatment of distal phalangeal nonunions

Nonunions of the shaft of the distal phalanx, as opposed to the tuft, are usually symptomatic enough to warrant treatment. One method that has proven successful while minimizing complications is compression fixation using variable pitch headless screws inserted percutaneously. Eighteen patients (15 males, 3 females) with a mean age of 48 years were so treated under digital block anesthesia. Seven of 18 (39%) patients were smokers. All initial injuries were crush trauma to the distal phalanx with 10/18 (56%) initially open fractures. Treatment was to 3 thumbs, 6 index fingers, 6 long, 2 ring, and 1 small. Fixation was with micro-sized variable pitch cannulated headless screws except 1 case that used 2 noncannulated threaded taper pins to compress a 3 fragment nonunion. Surgery to treat nonunion occurred at a mean of 13 weeks after the initial injury. Time to union was determined by combined clinical and radiographic assessment. The clinical criterion for union was the absence of pain at the nonunion site with application of maximum pinch pressure to the ipsilateral thumb or finger. The radiographic criteria for union was bridging trabeculae seen on 2 or more cortices and the absence of any signs of hardware loosening, using standard posteroanterior and lateral projections. All 18 patients went on to achieve union at a mean of 9 (±2.8) weeks after surgery. Complications specifically sought out but not identified were infection, loss of reduction, further comminution, hardware loosening, secondary surgery, nail deformity, and continued pain precluding successful pinch.