Evaluation of factors affecting the clinical outcomes of ganzosteotomy in the treatment of acetabular dysplasia in adolescents and young adults

Osteoarthritis secondary to acetabular dysplasia is among the causes of hip pain in adulthood. Different treatment methods have been described in the treatment of hip dysplasia, which has become symptomatic in the early stages of adulthood and adolescence. One of these treatment methods is the Ganz periacetabular osteotomy. In this thesis, it was aimed to determine the mid-long term radiological and clinical results of Ganz osteotomy and to investigate the factors affecting the clinical results. A total of 55 hips of 43 patients who underwent Ganz osteotomy with the diagnosis of acetabular dysplasia between January 1999 and December 2019 were included in the study. Operative age, arthrosis grade, preoperative and final follow-up Harris Hip Scores were determined. Preoperative and postoperative acetabular index, Sharp angle, lateral center edge angle, anterior center edge angele, anterior center margin angle, extrusion index, hip lateralization index, acetabular version and acetabular sector angles were measured on the patients' pelvic anterior-posterior radiographs and axial CT-MRI images. Preand postoperative radiological and clinical values were compared statistically. Correlation analysis of patients' Harris hip scores and hip joint movements with radiological values was performed to determine the variables affecting clinical outcomes. The mean of the patients was 19.85±6.57. The mean follow-up period of the patients was determined as 8.65±6.50 years. When the last follow-up films of 55 patients were evaluated, the mean Sharp angle was 34.91º±7.23º, the mean lateral center edge angle 29.98º ±11.90º, mean anterior center edge angle 45.67º ±16.34º, mean Tönnis angle 7.07 º±8.03º, mean extrusion index %12.44±12.96, mean anterior center margin angle 61.65º±4.36º, mean hip lateralization index 0.66±0.10, mean acetabular depth %23.84±3.98, mean acetabular version 12.29º ±14.93º, mean anterior acetabular sector angle 60.00º±20.06º, mean posterior acetabular sector angle 84.13º±14.34º, mean horizontal acetabular sector angle was 144.22º±18.03º. In clinical evaluation, mean Harris Hip Score was found as 81.62±14.10 at the last follow-up. When the preoperative and postoperative values were compared, statistical significant changes are found in the acetabular index, Harris Hip Score, Sharp angle, lateral center edge angle, anterior center edge angle, Tönnis angle, Tönnis stage, anterior acetabular sector angle, horizontal acetabular sector angle. There was no significant difference in pre- and postoperative values in terms of ACM angle, hip lateralization index and posterior acetabular sector angles. When radiological and clinical measurements were evaluated by correlation analysis, a statistically significant negative correlation was found between the Tönnis stage and the Harris hip score, hip flexion and hip external rotation at the last follow-up. Considering the results, it has been observed that Ganz periacetabular osteotomy has satisfactory results in the treatment of young adult and adolescent acetabular dysplasia. It causes significant changes in clinical scores and radiological parameters.