The Importance of Monitoring and Factors That May Influence Leg Length Difference in Developmental Dysplasia of the Hip

Abstract

In unilateral Developmental Dysplasia of the Hip (DDH), avascular necrosis (AVN), femoral or pelvic osteotomy, and residual dysplasia causing subluxation of the proximal femur may influence Leg Length Discrepancy (LLD). This can lead to gait compensation, pelvic obliquity, and spinal curvature. The aim of this study is to determine the prevalence of LLD, establish which limb segment contributes to the discrepancy, describe how AVN influences LLD, and ascertain variables that may influence the need for LLD corrective procedures. Methodology: This study assessed long-leg radiographs at skeletal maturity. Radiographs were assessed for the articulo-trochanteric distance (ATD) and femoral and tibial length. AVN was classified according to Kalamchi–MacEwen. Results: 109 patients were included. The affected/DDH leg was longer in 72/109 (66%) patients. The length difference was mainly in the subtrochanteric segment of the femur. AVN negatively influenced leg length. Older (≥three years) patients with multiple procedures were more likely to have AVN. LLD interventions were performed in 30 (27.5%) patients. AVN grade or type of DDH surgery did not influence the odds of needing a procedure to correct LLD. Conclusions: Procedures to correct LLD were performed irrespective of previous DDH surgery or AVN grades. In most patients, the affected/DDH leg was longer, mainly in the subtrochanteric segment of the femur, largely influenced by femoral osteotomy in patients with multiple operative procedures for DDH. We recommend careful monitoring of LLD in DDH.

Hip joint articulator-to-trochanteric distance measurements in children: which in children aged 5 to 14 years does not grow with age.

“…Rajiv M. Merchant once mentioned that in children with unilateral DDH, the growth of femur was the main factor that causes the difference in Leg Length Discrepancy (LLD). When the measured length was less than the unaffected side, the shortened part mainly focuses on the difference of ATD 10 . Some scholars had studied the difference of ATD of hip in children with unilateral SCFE, and thought that the reduction of ATD was a simple and sensitive method for early diagnosis of SCFE, which was better than other classic signs such as Trethowan sign, Loss of epiphyseal height etc 11 .…”

Impact of pubertal timing and socioeconomic status on adult height and body proportions in Igbo ethnicity

“…Studies have shown that earlier menarche is associated with shorter leg length or lower leg length ratio (Conway et al, 2012). This is because leg growth is more sensitive to hormonal changes than trunk growth during puberty (Merchant et al, 2022). Later menarche allows for more leg growth before reaching adulthood (Zhu et al, 2008).…”

CORR Insights®: Assessing Leg Length Discrepancy Is Necessary Before Arthroplasty in Patients With Unilateral Crowe Type IV Hip Dislocation

“…Overgrowth can be stimulated by femoral varus rotational osteotomies for hip reduction [10]. Femoral shortening may be necessary with open reduction of the hip with a delayed diagnosis, or it can be secondary to femoral head collapse from avascular necrosis [6]. Limb length discrepancy, that is, shortness, can be expected in hips with severe (Crowe Types III and IV) dysplasia.…”