Intramedullary skeletal kinetic distractor in the treatment of leg length discrepancy--a review of 16 cases and analysis of complications.

OBJECTIVE

The intramedullary skeletal kinetic distractor (ISKD; Orthofix) is a relatively new device available for limb lengthening. This fully implantable mechanical nail promises reduced morbidity over traditional methods where external fixation is used. We report on our experience using this device in treating 16 patients with leg length discrepancy.

DESIGN

Retrospective review of 16 consecutive patients treated with ISKD.

SETTING

Tertiary trauma hospital.

PATIENTS: Thirteen males and 3 females were treated with the ISKD between 2004 and 2009. There were 11 femora and 5 tibiae. The indication for lengthening was posttraumatic shortening in 15 patients and congenital hypoplasia in the remaining patient.

OUTCOME MEASURES: Limb length gained, rate of lengthening, time to consolidation, complications, and factors that may be associated with complications.

RESULTS

All patients in the series successfully completed treatment and reached the desired limb length with radiographic evidence of consolidation. The average leg length increase was 35 mm (21-75 mm). No infection, malunion, or joint contracture was observed. A length of less than 100 mm of the thick portion of the nail in the distal fragment is associated with the likelihood of a "runaway nail" (distraction index > 1.5 mm/d). Six patients had poor regenerate requiring bone grafting. Likelihood of poor regenerate was associated with number of previous operations on the lengthened bone. Three patients had nails that were difficult to distract and required closed manipulation under anesthesia.

CONCLUSIONS

The ISKD is an effective method for correcting leg length discrepancies. Complications are frequent but are manageable with standard techniques.

LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.