Vascularized metatarsophalangeal joint transfer for radial hypoplasia.
The relatively new concept and technique of microvascular joint transplantation for the correction of the congenitally deformed wrist is presented with a series of 24 operated radial club hands. The results from the 19 upper extremities with a mean follow-up of 11 years show that the new technique will not diminish the longitudinal growth of the ulna. The ulna length in the series is now 15.4 cm in mean and will develop further and presumably better than that reported in the previous long-term studies after centralization. The superiority in wrist active mobility compared with those of some previous long-term studies is reported with total active motion of 83 degrees in mean. The radial deviation deformity has become increased by 12 degrees in mean in the long-term follow-up compared with the results reported previously by the same author in the series of the first nine patients in 1998. The balance in the growth between the supporting metatarsal joint and the distal ulna has remained satisfactory, and the resting radial deviation angle is 28 degrees in mean (range, 0 to 45 degrees) in the cases with successful joint transfer. A subluxation tendency in six of the transplanted joints is a new finding, and its prevention needs careful attention during the reconstruction. With respect to timing, the joint alignment and transplantation procedure is best performed between the ages of 2.5 and 4 years according to the current experience of the author. A pollicization is usually added after the wrist alignment procedure. This technique will give the child a period of ~10 years without any new need for surgical treatment, and usually no splinting is needed during that period. However, an additional corrective osteotomy may be needed at early puberty depending on the growth properties of the joint graft and original ulna and because of ulnar bowing. The reported technique with preoperative and postoperative measures takes a period of about one-half year, and the whole procedure is considered quite demanding as far as an adequate preoperative soft tissue distraction and the microvascular joint transplantation are concerned. It is recommended that the treatment be performed in dedicated microsurgical centers with adequate pediatric tissue transfer experience.
Vilkki
Simo K
SK
Department of Hand and Microsurgery, Tampere University Hospital, Tampere Finland.