Fixation by Autogenous Cortical Plate Technique on Sites of Subtrochanteric Shortening Osteotomy Contributes to Early Bone Union in Total Hip Arthroplasty for Crowe Type IV Developmental Dysplasia of the Hip

Aim: Subtrochanteric shortening osteotomy (SSO) is often applied during total hip arthroplasty (THA) in high hip dislocations. The aim of the present paper was to evaluate the results of fixation by autogenous cortical plate technique on sites of SSO in THA for patients with Crowe type IV developmental dysplasia of the hip (DDH).Methods: We conducted a historical prospective cohort study and reviewed 67 patients (82 THAs) with SSO performed between March 2016 and May 2020. Thirty-nine patients (48 hips) obtained stability by intramedullary pressure provided by the S-ROM modular prostheses and with or without prophylactic binding by stainless-steel wire after osteotomy and before stem implantation (group A). Twenty-eight patients (34 hips) were fixed with autogenous cortical plate technique and stainless-steel wire or cables (group B). Time of operations, complications, radiographic results and clinical scores were compared.Results: One intraoperative fracture and a dislocation occurred, while component loosening, ectopic ossification and osteolysis were not observed. Group B had a higher union rate at the 4th month than group A (P = 0.015) while there were no significant differences of union rates at the 8th (P = 0.811) and the 12th month (P = 0.722) and of the average healing time (P = 0.181). No significant differences were found in hip function scores (HHS and WOMAC Osteoarthritis Index) between two groups.Conclusion: Fixation with autogenous cortical plate from the cylinder of femoral bone contributes to early bone union of osteotomy ends in Crowe type IV DDH patients compared to those who do not apply the technique. Besides of application of autogenous cortical strut grafts, relevant measures are as well recommended to prevent nonunion after SSO.