[Femoral lengthening by callotasis. A study of a series of 79 cases in children and adolescents].

PURPOSE OF THE STUDY

Results of femoral lengthening using callotasis method, with particular attention to the complications are presented.

MATERIAL AND METHODS

79 femoral lengthenings performed for limb length discrepancy in 75 children and adolescents were studied. Etiology of the femoral shortening was congenital in 23 cases, post-traumatic in 20, post-infection in 14, neurologic in 13, and miscellaneous in 9. Nine lengthenings were performed using the Judet lengthener and 70 using the Orthofix external fixator. We used gradual incremental distraction (callotasis).

RESULTS

Average lengthening achieved was 52 mm (range: 35 to 85), which represented a 17.7 per cent increase in femoral length (range 7.6 per cent to 64 per cent). There were 87 complications, i.e. 110 per cent. Several complications were often encountered during one lengthening, thus, 23 lengthenings (30 per cent) were performed without any complication and 49 (62 per cent) without additional unpredicted operations or anesthesia. All these complications were studied according to the stage (intraoperative, elongation, consolidation and delayed) in which they occurred and to their severity. They were assessed to establish their relationship to etiology of shortening, amount of lengthening and age. Intraoperative complications were rare (2 cases). In the distraction period, joint complications are the most frequent (33 complications), involving the hip 22 times and the knee 11 times; 28 healed without any problems, 14 needed reoperation and 1 dislocation of the hip led to an avascular necrosis.

DISCUSSION

The incidence of joint complications did not seem to be less than that encountered with previous methods of lengthening. The author believes that systematic tenotomies performed in order to avoid such complications in congenital short femurs are abusive and have to be discussed case-by-case. Bony consolidation was achieved without additional surgery in 90 per cent of cases. Eight patients had delayed consolidation but did not require surgery. Complicated consolidation was most commonly encountered in children less than 8 years old with congenitally short femurs. The author compared healing time according to the type of dynamization. A significant improvement was found when using a silastic collar (33.3 days/cm) in place of classical dynamization (46.6 days/cm).

CONCLUSION

The author believes that good results can be obtained by incremental distraction using uniplanar fixation. Results could be improved by proper fixator application, aggressive physical therapy and well-thought dynamization of the fixator.