The Use Of Anteversion Technique In Total Hip Arthroplasty For Patient With Developmental Dysplasia Of The Hip And Related Research

ObjectiveAdult developmental dysplasia of the hip is one of the main causes of hiposteoarthritis and most of these patients need surgery finally. Patient with developmentaldysplasia of the hip has many types of deformities which can increase the difficulty of thesurgery. Combined anteversion technique is proposed to make implanting prosthesis inappropriate position more easily. But this approach has not been used in THA for DDHpatient yet. This research is aimed at proving the rationality of this approach in THA forDDH patient and providing clinical evidence regarding the application of this approach.Also, we use computer aided methods to further study the relationship between the rangesof motion of the hip with the orientation of the prosthesis. Thus, we clarify the rationalityand superiority of this approach.MethodOur study mainly focused on the research about patient with developmental dysplasiaof the hip who underwent primary total hip arthroplasty in our hospital. All of the surgeryused combined anteversion approach. Every patient underwent a pelvic CT scan beforeand after surgery, and the Harris Hip score (HHS) was recorded for every patient beforesurgery and during the follow-up examination after surgery. All of the CT scans werereconstructed by Mimics. The femoral anteversion and acetabular anteversion before andafter surgery were measured after the reconstructed pelvis was relocated. Then we usedengineering software to measure the range of motion of the hip. All statistical analyses were performed using SPSS software. Student’s t-test and analysis of variance were usedto compare differences. And linear regression was carried on between prosthesisorientation and the range of motion of the hip to analysis their relationship. A P value of<.05was considered to represent a significant difference.ResultThe first part:1) The mean HHS increased from27.5±10.0before surgery to95.2±7.4at the last follow-up examination. No dislocation occurred.2) The femoralanteversion before and after surgery were20.7°±12.8°and18.6°±11.2°; The acetabularanteversion before and after surgery were23.0°±7.9°and20.6°±9.6°; The combinedanteversion before and after surgery were43.7°±13.8°and39.2°±7.5°.The second part:1) The mean HHS increased from27.5±8.9before surgery to97±5.1at the last follow-up examination. No dislocation occurred.2) The cup abduction angleafter surgery was46.53°±6.22°; The femoral anteversion after surgery was18.88°±10.30°;The cup anteversion after surgery was25.11°±10.16°; The combined anteversion aftersurgery was43.26°±10.18°.3) The ranges of motion of the hip after surgery wereanteflexion113.15°±10.17°, extension49.58°±16.14°, adduction37.23°±10.07°,abduction62.31°±6.81°, internal rotation112.81°±15.96°, external rotation43.96°±13.32°.ConclusionThe first part:1) All results of the follow-up examination and the image measurementafter surgery were satisfactory.2) All combined anteversion were located in the safe range.3) The combined anteversion approach was reasonable for total hip arthroplasty of patientwith developmental dysplasia of the hip and it can guarantee a satisfactory outcome aftersurgery.The second part:1) The hip underwent surgery using combined anteversion approachgot satisfactory range of motion. No because of the impingement between prosthesis components or skeleton affected the motion of the hip.2) The combined anteversion wassignificantly linear relative with multiple directions of the hip motion. Thus we consideredthe combined anteversion was the most important parameter of the prosthesis and thecombined anteversion approach of total hip arthroplasty was further more reasonable forpatient with developmental dysplasia of the hip.