Over the past fifteen years hip preservation surgery has rapidly evolved. Improved understanding of the pathomechanics and associated intra-articular degeneration of both hip instability and femoroacetabular impingement have led to improved surgical indications, refined surgical techniques and more effective joint preservation surgical procedures. The periacetabular osteotomy (PAO) was initially introduced by Ganz and colleagues and has become the preferred treatment in North America for pre-arthritic, symptomatic acetabular dysplasia. Both hip arthroscopy and safe surgical dislocation of the hip have been popularised for the treatment of symptomatic femoroacetabular impingement disorders. Hip arthroscopy is effective for focal and\or accessible impingement lesions while the surgical dislocation approach is reserved for nonfocal disease patterns as seen in complex FAI, and residual Perthes and SCFE deformities. Femoroacetabular impingement from major acetabular retroversion can be managed with the PAO if there is coexistent posterosuperior acetabular insufficiency. Short- to mid-term results of these procedures are generally good to excellent for most patients and the complication rates associated with these procedures are very acceptable. Long-term outcomes are best known for the PAO. Several recent studies have documented survivorship rates of 65–90% at 10–20-year follow-up. Certain factors are associated with long-term success including minimal pre-operative radiographic OA, early symptoms, accurate acetabular correction, and younger age. These data strongly suggest that the PAO can defer THA to an older age for most patients while completely avoiding arthroplasty may only be possible in select patients with excellent congruency, no secondary OA and an ideal surgical correction

Introduction. We perform PAO via a modified Smith-Petersen approach. The purpose of this study was to investigate the result of PAO via a modified Smith-Petersen approach at a minimum 10-years' follow-up. Methods. We retrospectively reviewed 209 hips in 179 patients with acetabular dysplasia who underwent PAO with a modified Smith-Petersen approach from August 1995 to April 2010. Exclusion criteria were as follows: under 10 year follow-up, incomplete clinical or radiographic data. Harris hip score (HHS) was investigated preoperatively, at the time of most improvement and at the final follow-up for clinical evaluation. Tönnis classification was investigated preoperatively and at the final follow-up for evaluation of osteoarthritis. Center edge (CE) angle and acetabular roof obliquity (ARO) were investigated preoperatively, postoperatively and at the final-follow up for radiographic evaluation. Tönnis classification and radiographic parameters were investigated on anterior-posterior radiographs. Patients of conversion of PAO to total hip arthroplasty (THA) were investigated for preparing Kaplan Myer survival analysis. The Wilcoxon signed-rank test was used to compare changes in HHS and radiographic parameters between the preoperative and the postoperative values. Statistical significance was defined a priori as p < 0.05. Results. Eighty-seven hips in 79 patients (44.1%) were included in this study. 100 patients were excluded from this study. The average age of the patients at the time of surgery was 39 years (rang, 15 to 65 years) and the mean follow-up period was 12 years and 2 months (range, 10 years to 18 years and 3 months). The mean HHS improved from 74 points (range, 38 to 98 points) preoperatively to 95 points (range, 62 to 100 points) at the time of most improvement (p < 0.01) and decrease slightly to 89 points (range, 32 to 100 points) at final follow-up. Tönnis classification was as follows: grade 0 was 4 hips preoperatively and 2 hips at the final follow-up, grade 1 was 55 hips preoperatively and 50 hips at the final follow-up, grade 2 was 25 hips preoperatively and 24 hips at the final follow-up, grade 3 was 3 hips preoperatively and 11 hips at the final follow-up. The mean CE angle improved from 5° (range, −19 to 24°) preoperatively to 30° (range, 2 to 56°) postoperatively (p < 0.01) and increased 38° (range, 12 to 68°) at final follow-up. The mean ARO improved from 24° (range, 6° to 45°) preoperatively to 6° (range, −14° to 48°) postoperatively (p < 0.01) and increased to 12° (range, −24 to 45°) at final follow-up. THA was performed on 5 hips in 5 patients (5.7%) after PAO. The mean duration between PAO and THA was 9 years and 6 months (range, 1 year and 4 months to 15 years 4 months). Ten-year survival rate was 97 % with conversion THA as the end point. Discussion & Conclusion. Clinical data and radiographic parameter were improved in patients who underwent PAO satisfactory. PAO was instrumental as time-saving surgical treatment of symptomatic acetabular dysplasia or slightly osteoarthritis because of 97% survival rate at 10 years

Introduction. Patients who are symptomatic with concurrent acetabular dysplasia and proximal femoral deformity may have Perthes disease. Osteotomies to correct both the acetabular and proximal femur deformities may optimise biomechanics and improve pain and function. In this study, we assessed the long-term results for such a combined procedure. Methods. We included patients who underwent concurrent pelvic and proximal femoral osteotomies by the senior surgeon (JNOH) with a minimum follow-up of 5 years. A modified triple pelvic interlocking osteotomy was performed to correct acetabular inclination and/or version with a concurrent proximal femoral osteotomy to correct valgus/varus and/or rotational alignment. We assessed functional scores, radiological paramenters, arthroplasty conversion rate, time interval before conversion to arthroplasty and other associated complications. Results. We identified 63 patients (64 hips) with a mean age of 29.2 years (range 14.3–51) at a mean follow-up of 10.1 years (range 5.1–18.5). The mean sourcil inclination postoperatively was 4.9. O. (range 1–12) compared to 24. O. (range 14.5–33) preoperatively. The mean Tonnis grade postoperatively was 2.2 (1–3) compared to 1.8 (range 1–2) preoperatively. At the last follow-up assessment, the mean Oxford Hip Score was 56 (range 60–47), Non-arthritic Hip Score was 71 (range 59–80) and UCLA activity score was 8 (range 5–10). There were 12 (18.8%) conversions to arthroplasty at a mean of 7.9 years (range 2.2–12.2) after surgery. Other associated complications include 1 sciatic nerve injury, 1 deep infection and 5 non-unions that required refixation. Discussion. Symptomatic acetabular dysplasia with concurrent proximal femoral deformity is difficult to treat. The use of combined pelvic and femoral osteotomies can optimise acetabular and femoral head alignment to improve pain and function with more than 4 out of 5 hips preserved at 10 years

Background. Rotational acetabular osteotomy (RAO) is an effective treatment option for symptomatic acetabular dysplasia. However, excessive lateral and anterior correction during the periacetabular osteotomy may lead to femoroacetabular impingement. We used preoperative planning software for total hip arthroplasty to perform femoroacetabular impingement simulations before and after rotational acetabular osteotomies. Methods. We evaluated 11 hips in 11 patients with available computed tomography taken before and after RAO. All cases were female and mean age at the time of surgery was 35.9 years. All cases were early stage osteoarthritis without obvious osteophytes or joint space narrowing. Radiographic analysis included the center-edge (CE) angle, Sharp's acetabular angle, the acetabular roof angle, the acetabular head index (AHI), cross-over sign, and posterior wall sign. Acetabular anteversion was measured at every 5 mm slice level in the femoral head using preoperative and postoperative computed tomography. Impingement simulations were performed using the preoperative planning software ZedHip (LEXI, Tokyo, Japan). In brief, we created a three-dimensional model. The range of motion which causes bone-to-bone impingement was evaluated in flexion (flex), abduction (abd), external rotation in flex 0°, and internal rotation in flex 90°. The lesions caused by impingement were evaluated. Results. In the radiographic measurements, the CE angle, Sharp's angle, acetabular roof angle, and AHI all indicated improved postoperative acetabular coverage. The cross-over sign was recognized pre- and postoperatively in each case. Acetabular retroversion appeared in one case before RAO and in three cases after RAO. Preoperatively, there was a tendency to reduce the acetabular anteverison angle in the hips from distal levels to proximal. In contrast, there was no postoperative difference in the acetabular anteversion angle at any level. In our simulation study, bone-to-bone impingement occurred in flex (preoperative/postoperative, 137°/114°), abd (73°/54°), external rotation in flex 0°(34°/43°), and internal rotation in flex 90°(70°/36°). Impingement occurred within internal rotation 45°in flexion 90°in two preoperative and eight postoperative cases. The impingement lesions were anterosuperior of the acetabulum in all cases. Discussion. It is easy to make and assess an impingement simulation using preoperative planning software, and our data suggest the simulation was helpful in a clinical setting, though there were some remaining problems such as approximation of the femoral head center and differences in femur movement between the simulation and reality. In the postoperative simulation there was a tendency to reduce the range of motion in flex, abd, and internal rotation in flex 90°. There was a correlation between acetabular anteversion angle and flex. Since impingement occurred within internal rotation 45°in flexion 90°in eight postoperative simulations, we consider there is a strong potential for an increase in femoroacetabular impingement after RAO