Simultaneous Bilateral Femoral and Tibial Lengthening in Achondroplasia

Lior Shabtai,Martin G Gesheff,Shawn C Standard,Philip K Mcclure,Julio J Jauregui,John E Herzenberg

doi:10.3390/children8090749

Abstract

Previous studies on lengthening for achondroplasia have reported bilateral extensive femoral lengthening followed by bilateral extensive tibial lengthening. To decrease trauma on soft tissues and joints, we propose bilateral simultaneous moderate femoral lengthening and moderate tibial lengthening followed by a similar repeat lengthening a few years later. Fifty patients with achondroplasia underwent 65 simultaneous bilateral femoral and tibial lengthening procedures. Segment lengthening amount and adverse events were obtained from medical records. Mean follow-up after bone healing was 35.6 months. Mean tibial lengthening was 52 mm; mean femoral lengthening was 72 mm. Average healing index was 1.4 months/cm for the tibia and 1 month/cm for the femur. Mean duration of treatment with external fixation was 6.7 months (range, 4.4–10.5 months). Thirty-eight (76%) of 50 patients experienced one or more adverse events during lengthening. We observed 78 adverse events, 35 (45%) of which required additional surgical procedures. All resolved by the end of treatment. Mechanical axis deviation improved from a mean of 15 mm medially to 8 mm medially. Simultaneous lengthening of four segments in patients with achondroplasia is a feasible strategy. Compared with isolated femoral or tibial lengthening, distributing the lengthening between the femur and tibia decreases total external fixator time.

Highlights

Achondroplasia is the most common dwarfing disorder affecting humans, with an incidence of one in 20,000 to 30,000 live births [1]
While multiple trials are underway with experimental agents for treatment of some features of achondroplasia, it is likely that a role for surgical limb lengthening in patients with functional deficits will persist in the near future
In an effort to decrease the trauma to soft tissues and joints, we propose bilateral simultaneous moderate (5–7 cm) femoral lengthening and moderate (4–5 cm) tibial lengthening (Figure 2b)

Summary

Introduction

Achondroplasia is the most common dwarfing disorder affecting humans, with an incidence of one in 20,000 to 30,000 live births [1]. Limb lengthening in patients with achondroplasia is controversial. Supporters claim that there are purposeful and psychosocial benefits of achieving functional height (i.e., greater than 150 cm) [3,4,5]. A study by Kim et al [5] showed that patients with achondroplasia tolerate a greater amount of lengthening with fewer complications compared with patients of other etiologies. Opponents claim that achondroplasia is a normal variant and that limb lengthening does not address any medical problem and may put patients at risk for disability secondary to complications [6]. While multiple trials are underway with experimental agents for treatment of some features of achondroplasia, it is likely that a role for surgical limb lengthening in patients with functional deficits will persist in the near future

Methods

Results

Conclusion