Vichai Vanadurongwan

Results of 1018 digital replantations in 552 patients

To find out the influencing factors of the immediate and late outcome of replantation and revascularization of the digits the study was carried out as a prospective survey research during 1983 to 1995 with at least 2 year follow up. Traumatic total or subtotal amputation with inadequate circulation of the digits distal to the metacarpal head were included in the study. There were 552 patients with 366 males (675 digits) and 186 females (343 digits). Successful operation was found in 508 patients (92%) with 946 digits (92.9%). Type of injury was the most important factor influencing immediate and late outcome. Regular cigarette smoking resulted in poor immediate survival rate. Prolonged ischaemia had a significant influence in final functional outcome. Using composite skin and subcutaneous vein graft gave good survival rate. Injury at the no mans land area resulted in poor range of movement of the digit. Connecting the profundus tendon stump of the proximal part to the superficialis tendon of the amputated part gave a better result than 2 tendon repair and repairing only the profundus tendon. Replantation should be carried out even if only one digit is involved. At the 2 year follow up 195 patients (38%) were classified in grade I of Chen et al., functional outcome, while 153 (31%) were in grade II, 124 (24%) were in grade III and 36 (7%) were in grade IV.

The talar body prosthesis.

Arthrodesis or talectomy for the treatment of avascular necrosis of the talus or a severe crush fracture of the body of the talus often produces a disability of the ankle and the foot. Therefore, a prosthesis designed to replace the body of the talus and to preserve the function of the ankle and the foot was developed. The prosthesis has a superior curved surface, and the medial and lateral surfaces are inclined for articulation with the tibia and the fibula. The inferior aspect has a concave curved surface at the posterior aspect of the prosthesis to serve as the posterior facet for articulation with the posterior facet of the calcaneus, and there is a convex curved surface at the anterior aspect of the prosthesis for articulation with the middle facet of the calcaneus. The neck and the head of the talus are preserved to allow insertion of the prosthetic stem into bone. A transmedial malleolar approach is used for insertion of the prosthesis. We inserted the talar body prosthesis in sixteen patients—twelve who had avascular necrosis of the talar body and four who had a severe crush fracture of the talar body—between 1974 and 1990. Three patients who were evaluated five years postoperatively had a satisfactory result, and one patient had failure of the prosthesis at eight months because the diameter of the inferior concave curved surface was too small in the region of the posterior facet and had caused erosion of the posterior facet of the calcaneus. All three patients who were evaluated six to ten years postoperatively had a satisfactory result. All except one of the nine patients who were evaluated eleven to fifteen years postoperatively had a satisfactory result; the exceptional patient had an unsatisfactory result because the prosthetic stem had sunk into the talar neck. This patient had a revision thirteen years after the index operation. We believe that the talar body prosthesis can be used to replace the body of a talus with avascular necrosis or a severe crush fracture, thus maintaining the function of the ankle and the foot for a prolonged period.

Vascular injuries in compound fractures of the leg with initially adequate circulation

We carried out a randomised, controlled trial in 157 patients who had isolated severe Gustilo type-IIIa and type-IIIb fractures of the metaphysis or diaphysis of the leg to determine the prevalence of vascular injuries and the role of vascular repair. All patients had stable vital signs and clinically adequate circulation in their legs before operation. In a control group of 64 patients we performed conventional surgery with systematic debridement and primary stabilisation of the fractures. In the trial group of 93 patients the major vessels and nerves adjoining the compound fracture were routinely explored and repaired when necessary after the initial procedure. Two of the 28 control patients (7.1%) with type-IIIb compound fractures had signs of inadequate circulation after the first operation. Both had major vascular injuries which were demonstrated at a second procedure. In the trial group, major vascular injuries were found in two of 54 patients (3.7%) with type-IIIa and 11 of 39 patients (28.2%) with type-IIIb compound fractures. Compared with the control group the trial group showed improved results at both the immediate and long-term follow-up. Routine exploration and early repair of injured major vessels of the leg in severe compound fractures gave encouraging results.

An aiming device for pin fixation at the iliac crest for external fixation in unstable pelvic fracture

To improve the accuracy of pinning at the iliac crest during external fixation of the pelvic fracture, an aiming device has been designed. The device consists of 3 parts: a sleeve which accommodates a 5.0 Shanz pin, a handle and guide points. The guide points were designed to grasp the iliac crest to allow proper pin fixation. The device has undergone trials to fix Shanz pins on the iliac crests of 10 cadavers by 10 recently graduated doctors. All pins were fixed in proper position and passed into the bone between the two tables of the iliac crest without penetrating the tables. The device has so far been used in 50 patients who had unstable pelvic fractures. All pins were in the proper positions and there had been no loosening at the time the pins were removed. The use of this aiming device for pinning the iliac crest for external fixation of pelvic fracture has given encouraging results.

Revascularization of subtotal amputation at the ankle in children following motorcycle-spoke injury

A prospective study of subtotal amputation of the ankle following motorcycle spoke injury was carried out to define the mechanism of the injury and results of revasculization. Between 1990 to 1995, there were 42 patients with this type of injury. They were 31 boys and 11 girls. All sustained severe skin lacerations, medial, posterior, lateral and anterior to the ankle joint. All tendons and neurovascular bundles medial, lateral and anterior to the ankle were completely torn, leaving tendons of anterior tibial, extensor hallucis longus and extensor digitorum communis intact. Revascularization was performed successfully in 38 patients. All had good functional outcome although varus of the distal tibia, limitation of ankle motion, shortening of the foot and limb length discrepancy were observed. The motorcycle wheel needs to be redesigned.

Relationship between foot length and the inter anterior superior iliac distance

Reduction of unstable pelvic fracture by external fixator might be over or under corrected as there is no proper estimation from the surgical landmark. Radiographic evaluation after reduction must be carried out and improper reduction is found in a certain number. To find a better guide by normal surgical landmark the study was carried out as a survey research in 600 volunteers aged from 10 to 70 years. Simple caliper and tape were used to measure the height, foot length and inter anterior superior iliac spine distance. In 376/420 male volunteers (89%), the length between right heel and tip of the fourth toe was equal to the inter anterior superior iliac spine distance. In 173/180 female volunteers (96%), the length between right heel and tip of big toe was equal to the inter anterior superior iliac spine distance. The length of the right foot can be used as a reference in reducing unstable fractured pelvis by external fixation. These data were used in the management of 36 patients with unstable fractured pelvis with external fixation for reduction and stabilization. All had good results.