Abstract
1. The results of repair of the sciatic nerve and of its main divisions have been analysed in a series of 118 cases, the patients having been under observation for three to eighteen years (average 11·7 years).
2. A result was satisfactory if there was some return of sensibility throughout the autonomous zone (the area of skin supplied exclusively by the damaged nerve) and if the more important muscles of the leg were capable of contraction against gravity and resistance.
3. When the whole of the sciatic nerve is damaged it is necessary to present the results separately for the lateral and medial popliteal divisions.
4. Of forty-seven cases of repair of the medial popliteal nerve 79 per cent showed useful motor and 62 per cent useful sensory recovery. In three out of four cases the correspondence between the degree of motor and of sensory recovery was fairly close.
5. Of seventy-two cases of repair of the lateral popliteal nerve 36 per cent showed useful motor and 74 per cent useful sensory recovery. The latter figure must be regarded with some reserve because sensory "recovery" in the lateral popliteal zone may be due to the ingrowth of nerve fibres from contiguous normally innervated skin. Thus it is not possible to correlate motor and sensory recovery.
6. In eighteen cases of repair of the posterior tibial nerve, there was useful sensory recovery in the sole in twelve. But although there was evidence of recovery in the plantar muscles in eleven cases it was functionally valueless.
7. In repair of the medial popliteal nerve the result was better if suture had been carried out early. In repair of the lateral popliteal nerve there was no evidence that delay was harmful; but the proportion of good results was so low (as judged by motor function alone, sensory recovery being often extraneous) that this exception to a general rule cannot be taken very seriously.
8. Gaps of up to twelve centimetres–estimated after resection of the damaged nerve ends–could be closed without difficulty by the usual technique, and the extent of the gap up to that limit had no influence on the prognosis. The closure of larger gaps, when the knee must be flexed beyond a right angle, is not compatible with good recovery because the post-operative stretching of the nerve causes serious intraneural damage.
9. Nerve grafting has given poor results in repair of the sciatic nerve.
