Knee Range of Motion in Isolated Femoral Lengthening

Abstract

Twenty-five patients underwent isolated Ilizarov femoral lengthenings (mean lengthening, 6 cm). A retrospective review of the charts showed the specific changes in knee range of motion (ROM) during lengthening, after removal of the frame, and at the final follow-up examination. A decrease in ROM was seen during lengthening to an average minimum of 37" f 15". Toward the end of the consolidation phase, improvement to 69" f 28" was noted. A progressive increase in ROM was seen after frame removal. Mean preoperative flexion was 127" f 16", and at follow-up flexion was 122" f 23" (p = 0.191). Of the five patients who did not achieve 120" flexion at the final follow-up examination, three had a diminished ROM (average, 107") at the outset. Two patients lost more than 15% of their preoperative flexion. There was no correlation noted between worst ROM (during lengthening) and final ROM at the last follow-up examination.Newer techniques of limb lengthening have improved the end results and decreased the permanent sequelae associated with these complex procedures.' The method of distraction osteogenesis has helped solve many complications associated with bone healing such as nonunion, malunion, deep infection, and internal fixation (plate) failure that were seen frequently with the Wagner technique.' However, complications associated with soft tissue such as muscle contracture and joint stiffness may be related to lengthening itself or the transfixion pins used with external fixation. Joint motion can be protected during lengthening, so that function is never sacrificed for the sake of achieving bone length.4,7-8,'3 Empirical evidence would suggest cessation of femoral lengthening if knee flexion diminishes to 4 5 O . I )The purpose of this study was to evaluate the natural history of knee range of motion (ROM) during and after femoral lengthening, and to determine which factors correlate with a satisfactory final ROM at the followup examination. MATERlALS AND METHODSA retrospective chart review was conducted of all patients who underwent femoral lengthenings by either of the two senior authors. Only isolated femoral lengthenings with or without angular corrections were studied. Patients who had simultaneous femoral and tibia1 lengthenings were excluded. To be included, there had to be documentation of the preoperative ROM, at least three measurements of knee ROM during the external fixation period, and at least three measurements of knee ROM after removal of the external fixator.A hybrid llizarov frame was used (Italian modification) with half-pins proximally and wires or combinations of wires and half-pins distally.' Three distal fixation patterns were empirically 49

Lengthening With External Fixation Is Effective in Congenital Femoral Deficiency

“…These results from our study are similar to previously published results in a series of 25 patients who underwent isolated femoral lengthening of 6 cm on average, in which patient knee ROM decreased to a minimum of 37°at the end of lengthening, increased to 69°at the end of consolidation, and recovered to normal at last followup [16]. The authors estimate that the usual rate of improvement in ROM after lengthening is 10°per month, but the last 20°of knee flexion may take up to 2.5 years to recover.…”

Internal Lengthening Device for Congenital Femoral Deficiency and Fibular Hemimelia

“…This improved ROM during the distraction process prevents muscle contractures, joint stiffness, and most importantly joint subluxation or dislocation [27]. Studies demonstrate that there is a rapid return of knee flexion on removal of the external fixator [18,28]. In our study, the ROM at latest followup was not different from the ROM obtained before the index procedure.…”

Current concepts of leg lengthening

“…Maximal knee flexion can reduce to 30-40°d uring the distraction period and is more of a problem than extension [6,9,18,156,160,162].…”