Gait Improvement After Distal Femoral Osteotomy for Permanent Patellar Dislocation Following Femoral Lengthening in an Adolescent With Achondroplasia: A Case Report

TL;DR

A teenager with achondroplasia improved his walking ability after surgery and rehabilitation for knee deformities caused by previous femoral lengthening.

Contribution

Demonstrates effective gait improvement through distal femoral osteotomy and targeted rehabilitation in a rare skeletal dysplasia case.

Findings

Walking speed increased from 0.60 m/s to over 1.0 m/s after surgery and rehabilitation.

Lateral asymmetry and load patterns in gait were normalized following the intervention.

The patient achieved independent walking without aids after nine weeks of rehabilitation.

Abstract

In patients with skeletal dysplasia, certain disease-specific and treatment-related characteristics may affect functional outcomes following orthopedic surgery. We report a case of valgus deformity with permanent patella dislocation after femoral lengthening treated with distal femoral osteotomy (DFO), in which improvement in gait ability was achieved during the postoperative rehabilitation course. A 15-year-old Japanese boy with achondroplasia (ACH) had undergone tibial and femoral lengthening. During the femoral lengthening, valgus deformity and the accompanying permanent patella dislocation on both sides appeared; therefore, a staged bilateral knee osteotomy was scheduled. The preoperative status included a decreased walking speed of 0.68 m/s with a requirement for crutches. The surgery was performed bilaterally with a six-week interval and included DFO, lateral retinacular release, and medial patellofemoral ligament (MPFL) reconstruction. After a six-week non-weight-bearing period in each limb, the patient was able to walk independently with crutches; however, lateral asymmetry and lack of bimodal pattern, in addition to a decreased speed of 0.60 m/s, were noted by gait analysis. Additional rehabilitation programs, including gait training using real-time feedback of absolute load, were implemented to increase lower-limb loads and normalize the gait cycle. After a further nine weeks of inpatient rehabilitation, improvements in lateral asymmetry and load pattern were observed with a speed of >1.0 m/s without a walking aid. These results highlight that perioperative rehabilitation combined with DFO can effectively improve physical function in ACH patients with severe functional impairments and characteristic limb deformities.

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