How do the Different Levels of Femoral Osteotomy Applied for Femoral Shortening and/or Derotation in the Treatment of DDH Affect Radiological and Clinical Outcomes

INTRODUCTION: In the present study, different femoral osteotomy levels applied in the combined surgical treatment of the patients aged over 2 years with developmental dysplasia of hip (DDH) were compared. It was aimed to determine the advantages and disadvantages of the osteotomies performed at the shaft and subtrochanteric regions of the femur and to evaluate their radiological and clinical impact on hip development. METHODS: The study included the patients aged over 2 years with DDH who were applied open reduction, Pemberton pericapsular osteotomy and femoral osteotomy. The demographic information, clinical evaluations and radiographic results of the patients were applied from the medical records. In addition, radiation exposure (the number of fluoroscopic images), operation duration and present of complications were evaluated. The hips were divided into two groups based on the level of femoral osteotomy as shaft (group 1) and subtrochanteric (group 2) groups. The Tönnis Classification System was used to assess the grade of preoperative hip dysplasia. Radiological evaluation was performed according to Severin's criteria while modified McKay's criteria was applied for clinical evaluation. Kalamachi and MacEwen's criteria were preferred for evaluation of avascular necrosis (AVN). RESULTS: Of the 46 hips, 21 hips were in the body group and 25 hips were in the subthoracanteric group. No statistically significant difference was present between the groups in terms of age, Tönnis type of hip dysplasia, preoperative acetabular index, postoperative acetabular index, preoperative collo-diaphyseal angle, postoperative collo-diaphyseal angle and derotation grade (p>0.05). The difference between the follow-up durations of the groups was statistically significant. The follow-up duration of the group 1 was shorter than the group 2. Although, clinical results in the group 1 were proportionally better than the group 2, no statistically significant difference was determined between the groups (p= 0.1264). A statistically significant difference was detected between the groups in terms of radiological results (p= 0.0008). AVN was found in none of the hips in the group 1 whereas 8 hips were detected with AVN in the group 2. The difference between the groups regarding femoral head AVN was statistically significant (p=0.0043). There was a statistically significant difference between the groups in terms of operation duration and radiation exposure (p<0.0001). Subluxation or redislocation developed in none of the cases. DISCUSSION AND CONCLUSION: Femoral osteotomy performed for femoral shortening and derotation at the region of femoral shaft can be used as an alternative surgical procedure without increasing the risk for AVN in the pediatric patients aged over 2 years with DDH.