Résumé
Introduction A series of twenty eight cases of Kienbock's disease treated by a shortening osteotomy of the radius are reported.
Material and methods The series consisted of sixteen male and twelve female patients with an average age of twenty-five and followed for an average of five years. Seventeen patients were manual workers. The dominant side was affected in twenty cases; there were no bilateral cases. The clinical grades before surgery were one case in stage I, ten stage II, thirteen stage III, and four stage IV, using the Decoulx classification. The preoperative distal radio ulnar index was greater than 0 in only one case. Average radial shortening was three millimeters, The osteotomy was stabilized by using dynamic compression plates in fourteen cases, pinning in twelve cases, and staples in two cases.
Results In all the cases, the results on pain relief and muscular strength were satisfactory. During preoperative review, pain was a major complaint in seventeen cases, moderate in nine cases, and slight in two cases.
Joint range of motion (ROM) was, in seven cases, greater than seventy-five percent when compared to the opposite hand; in fourteen cases greater than fifty percent; less than fifty percent in five cases and less than twenty-five percent in two cases. Muscular strength, measured by J.A.M.A.R. test, was decreased in six cases by seventy-five percent when compared with the healthy side; in nineteen cases decreased by fifty percent and in three cases decreased by twenty-five percent. On the post-operative review, pain was decreased in all cases: twenty patients were pain free, seven felt slight pain during forced movements. Only one patient showed no improvement: he had a work related injury, with reflex dystrophy. A twelve percent increase in postoperative ROM was noted. Muscular strength improved by an average of forty one percent: 8 cases recovered normal strength, fifteen cases improved strength to seventy-five percent, and five cases improved to fifty percent.
The overall clinical result did not seem to depend on the age of the patient or the preoperative radiological stage. They were evaluated using the criteria described by Michon.
We obtained fourteen excellent results, ten good, four average. Twenty-five patients have been able to their previous job, three changed jobs.
For the preoperative radiological assessment, we followed the Decoulx and the Lichtman scales and considered the distal radio ulnar index, the radial slope, the Linscheid lunate bone dimple incline and the Young and Mac Murtry measurement of the carpal collapse. Radiological assessment showed lunate bone remodeling in the ten cases rated stade II. Nine out of the thirteen patients rated stade III improved: two of them were rated stade II and seven cases presented an improvement of the radiological aspect. Four cases worsened.
Discussion There was no parallel between the radiological evolution of the lunate bone and clinical results. Furthermore, radiological assessment did not show any true relationship between changes in the distal radio ulnar index and radiological evolution. The post-operative distal radio ulnar index was zero in eight cases, greater than one in fourteen cases and greater than two in six cases. Only the obliquity of the radial dimple opposite to the lunate bone is related with the radiological evolution. In the nine cases of stage Ill that have improved, the radial dimple slope was increased. The four cases of stage III that worsened, it was decreased.
Conclusion A shortening osteotomy of the radius is a satisfactory procedure independently of whatever the disease's age, the lunate bone radiological stage and the distal radio ulnar index. The only factor we think capable of modifying the radiological result of necrotic evolution is the lunate bone slope. It appears necessary, during the osteotomy, to increase this slope in order to reduce local pressure.