Sixty-two epiphyses in forty-nine patients were stapled. Seven patients were subjected to stapling for knock-knee deformity and forty-two for limb-length discrepancy.

Limb-Length Discrepancy

The improvement in limb-length discrepancy was disappointing. Frequently in a two-year period, the two limbs grew at about the same rate. From a study of growth charts, it was determined that one cannot expect correction of a major discrepancy in limb lengths in a two-year period. This is especially true if only one epiphysis is stapled or if the patient is not growing rapidly during the time the staples are in place.

It became apparent that some of the gain obtained by the stapling was later lost during a period of rapid growth. Enough time has not elapsed for this point to be made with certainty.

Partial extrusion of staples was fairly common. Perhaps the results would have been better if more of the partially extruded staples had been replaced. This means that the patient must undergo a second operation and finally a third operation when the staples are removed.

In sixteen patients (33 per cent.) epiphysiodesis was done after the staples had been removed because of residual major discrepancy.

Staples buried in bone were a common finding, especially when the staples had been placed subperiosteally. There were six cases of epiphyseal arrest, in five of which the staples had been placed subperiosteally. In three, however, linear growth continued normally in spite of this complication, after the staples had been removed. Nevertheless, buried staples are a hazard in patients in the younger age group.

Back-knee deformities as a postoperative complication were too common. These might be avoided by more careful attention to the placing of the staples in the posterior aspect of the tibial epiphysis.

In general, the limited data available indicates that linear growth continues normally or almost so, after staples have been removed, excluding, of course, cases of epiphyseal arrest.

Knock-Knee Deformity

The results in patients with knock-knee deformity were better. Most patients were improved. However, in two patients a significant back-knee deformity developed, but in both instances this was probably due to the preoperative condition.