First ray reconstruction with distraction osteogenesis

Abstract

Disarticulation of the thumb at the metacarpophalangeal joint level is not beneficial either aesthetically or functionally without additional surgery because it requires a bulky and an unacceptable prosthesis to be made for this amputation level. In this study, the authors have presented our experience of 12 metacarpal distractions in thumb amputated patients. Twelve male patients who had thumb amputation due to gunshot wounds were included in the study. Before the operation, aesthetic hand prostheses were made for 5 of the 12 patients. Callus distraction was performed with the use of a mini Ilizarov type external fixator in 7 cases and uniplanar dynamic mini external fixator in 5 cases too. External fixators were removed after the completion of the radiographic consolidation. Five patients whose prosthesis had been made before the operation wore their prosthesis for an average 6.8 months (5 - 14) due to poor appearance and poor construction. Union of the lengthened segment was observed in all cases. Average lengthening was 28.9 mm (range from 25 - 37). Average healing time was 2.1 months (range from 1.8 - 2.5). Average healing index was 0.73 month/cm (range from 0.65 - 0.88). Pin tract infection was seen in 7 cases (58.3%). Volar angulation developed after removing the external fixator in 1 case. Webplasty was performed in all cases. Patients were evaluated by means of Disability of the Arm, Shoulder and Hand (DASH) score and pick-up test. It was concluded that the metacarpus lengthening by callus distraction technique may be a functionally and cosmetically effective reconstruction method for traumatic thumb amputations. It is believed that the possibility for a functionally and aesthetically acceptable fabrication of a thumb prosthesis, by providing a suction suspension with distraction and/or webplasty procedures.