Correction of gait after derotation osteotomies in cerebral palsy: Are the effects predictable?

Changes in hip abductor moment 3 or more years after femoral derotation osteotomy among individuals with cerebral palsy

“…Trunk and pelvic obliquity were measured relative to the lab. Anteversion and hip rotation, which determine coronal plane gluteus medius moment arms, were quantified as they change after an FDO . Physical therapists measured anteversion using the trochanteric prominence angle test and measured isometric hip abductor strength using manual muscle testing (higher scores indicate greater strength)…”

“…The compensatory mechanism theory predicts that the increase in coronal plane hip abductor moment arms after an FDO leads to increased hip abductor moments and decreased compensatory IHR. Several studies have cited Arnold et al as evidence for excessive anteversion leading to compensatory IHR and for FDO as an appropriate treatment . Although changes in IHR after FDO have been extensively studied, no one has quantified how hip abductor moment during gait changes at short‐ (approx.…”

Femoral derotation osteotomy—Does intraoperative electromagnetic tracking reflect the dynamic outcome?

“…This finding might be an indication that preoperative rotational imaging is an important additional tool in the planning of FDO. Although previous studies found a poor correlation between femoral anteversion and dynamic hip rotation measurement through three-dimensional gait analyses, 7,9,25,33 it could help distinguish between static and dynamic components of internal rotation gait more precisely and through this improve indication management. Whether this would lead to better prediction of outcomes must be evaluated in further investigations.…”

“…Arnold et al 5 and Gage and Novacheck 6 showed that increased femoral anteversion and valgus deformity of the femoral neck decrease hip abductor moment and internal rotation gait may be a compensatory mechanism to restore hip abductor moment. Although femoral anteversion contributes to hip orientation during walking, the correlation between the two is poor, and coronary plane kinematics in three‐dimensional gait (3‐D‐Gait) analysis reflect muscular influences in the same way 7–9 . This indicates that both soft tissue procedures (e.g., muscle lengthening) and bony corrections such as femoral derotation osteotomy (FDO) may be used to address the pathology.…”

“…Although femoral anteversion contributes to hip orientation during walking, the correlation between the two is poor, and coronary plane kinematics in three-dimensional gait (3-D-Gait) analysis reflect muscular influences in the same way. [7][8][9] This indicates that both soft tissue procedures (e.g., muscle lengthening) and bony corrections such as femoral derotation osteotomy (FDO) may be used to address the pathology. Depending on possible additional deformities, the osteotomy may be performed at the proximal or distal femur allowing the surgeon to simultaneously correct these.…”