Periacetabular osteotomy: a review of swiss experience

Radiologic Predictors for Clinical Improvement in PAO-A Perspective Study

The aim of this study was to evaluate the results of surgical treatment of developmental dysplasia of the hip (DDH) with periacetabular osteotomy (PAO) and determine the values of radiological parameters that would allow us to obtain an optimal clinical result. Radiological evaluation included determining the center-edge angle (CEA), medialization, distalization, femoral head coverage (FHC), and ilioischial angle as measured on a standardized AP radiograph of the hip joints. Clinical evaluation was based on the HHS, WOMAC, Merle d'Aubigne-Postel scales and Hip Lag Sign. The results of PAO presented decreased medialization (mean 3.4 mm), distalization (mean 3.5 mm), and ilioischial angle (mean 2.7°); improvement in femoral head bone cover; an increased CEA (mean 16.3°) and FHC (mean 15.2%); clinically increased HHS (mean 22 points) and M. Postel-d'Aubigne (mean 3.5 points) scores; and a decrease in WOMAC (mean 24%). HLS improved in 67% of patients after surgery. Qualification of patients with DDH for PAO should be based on the following values of three parameters: CEA < 26°, FHC < 75%, and ilioischial angle >85.9°. To achieve better clinical results, it is necessary to increase the average CEA value by 11° and the average FHC by 11% and reduce the average ilioischial angle by 3°.

Hip dysplasia in adolescence: osteotomy in childhood improves the results of periacetabular osteotomy in adolescents and young adults : a prospective study

AIMS

Developmental dysplasia of the hip (DDH) describes a pathological relationship between the femoral head and acetabulum. Periacetabular osteotomy (PAO) may be used to treat this condition. The aim of this study was to evaluate the results of PAO in adolescents and adults with persistent DDH.

METHODS

Patients were divided into four groups: A, adolescents who had not undergone surgery for DDH in childhood (25 hips); B, adolescents who had undergone surgery for DDH in childhood (20 hips); C, adults with DDH who had not undergone previous surgery (80 hips); and D, a control group of patients with healthy hips (70 hips). The radiological evaluation of digital anteroposterior views of hips included the Wiberg angle (centre-edge angle (CEA)), femoral head cover (FHC), medialization, distalization, and the ilioischial angle. Clinical assessment involved the Harris Hip Score (HHS) and gluteal muscle performance assessment.

RESULTS

Significant improvements in radiological parameters were achieved in all measurements in all groups (p < 0.05). The greatest improvement was in CEA (mean of 19° (17.2° to 22.3°) in Group B), medialization (mean of 3 mm (0.9 to 5.2) in Group C), distalization (mean of 6 mm (3.5 to 8.2) in Group B), FHC (mean of 17% (12.7% to 21.2%) in Group B), and ilioischial angle (mean of 5° (2.3° to 8.1°) in Group B). There were significant improvements in the mean HHS and gluteal muscle performance scores postoperatively in all three groups.

CONCLUSION

The greatest correction of radiological parameters and clinical outcomes was found in patients who had undergone hip surgery in childhood. Although the surgical treatment of DDH in childhood makes subsequent hip surgery more difficult due to scarring, adhesions, and altered anatomy, it requires less correction of the deformity and has a beneficial effect on the outcome of PAO in adolescence and early adulthood. Cite this article: Bone Joint J 2022;104-B(7):775-780.

Case Report: Intraarticular Iliopsoas Tendon causes Groin Pain Following Periacetabular Osteotomy

A 43-year-old female patient reported persistent iliopsoas-related groin pain following periacetabular osteotomy (PAO) combined with femoroplasty via a direct anterior approach due to CAM morphology. Concomitantly with the planned removal of screws, hip arthroscopy was performed, and the iliopsoas tendon was found to run intraarticularly, resulting in the tendon being impaired in its mobility and being entrapped. The tendon was arthroscopically released. The patient reported relief of the groin pain after the arthroscopic tendon debridement. During PAO combined with capsulotomy, the postoperatively observed intraarticular position of the iliopsoas tendon should be prevented by careful closure of the joint capsule.

The corona mortis: is it a rare and dangerous anomaly in adolescents undergoing periacteabular osteotomy?

The corona mortis (CM) is a vascular connection between the obturator and external iliac or internal epigastric vessels that has historically been identified as a source of hemorrhage in pelvic surgery. However, its frequency, location, proximity to the osteotomies performed, vascular contributions and impact on blood loss in patients undergoing periacetabular osteotomy (PAO) are unknown. We sought to identify the frequency, origin, location relative to osteotomies performed during surgery and impact on blood loss of the CM. Preoperative magnetic resonance imaging (MRI) of the hips of 28 adolescent patients (56 hips) undergoing PAO was retrospectively reviewed for the presence of a CM. When identifiable, the size, nature (arterial or venous), orientation, position relative to the iliopectineal eminence (IPE) and associated estimated blood loss (EBL) were recorded. 75% (21/28) of patients possessed an identifiable, ipsilateral CM to the site of PAO, 90% of which were venous and 10% arterial. The vessel was typically 8.3 ± 3.8 mm medial and 11.1 ± 5.3 mm caudal from the anterosuperomedial edge of the IPE. There was no significant difference in the amount of EBL (519 ± 260 versus 694 ± 369 ml) or need for post-op transfusions (1/21 versus 0/7) between patients who possessed a CM and those who did not, respectively (P = 0.21). CM was more prevalent in this study than previously reported. However, the presence of an ipsilateral CM was not associated with an increase in EBL or transfusion during routine PAO surgery using modern surgical techniques.

Combined Hip Arthroscopy and Periacetabular Osteotomy (PAO): Technical Focus on Arthroscopically Elevating the Iliocapsularis and Performing the Open PAO

In this Technical Note, we discuss the combined hip arthroscopy and periacetabular osteotomy (PAO) for the treatment of symptomatic hip dysplasia, with a focus on the technique we use for the PAO. We identify modifications that can be made during the arthroscopic portion of the procedure to assist in the PAO dissection, including arthroscopic capsular closure and arthroscopic elevation of the iliocapsularis muscle off the capsule, which allows for expedited open exposure during the PAO.

Bernese peri-acetabular osteotomy performed with navigation and patient-specific templates is a reproducible and safe procedure

PURPOSE

To present a novel surgical technique for the Bernese peri-acetabular osteotomy (PAO) using electromagnetic navigation (EMN) and patient-specific templates (PST), and to evaluate it against the traditional fluoroscopic technique.

METHODS

We included 40 dysplastic hips. All PAOs were performed using PST and EMN. We recorded learning-related complications. For the purpose of acetabular fragment correction analysis, patients were divided into two groups. In the study group (EMN group, 30 hips), the acetabular fragment was reoriented with the help of EMN. In the control group (XR group, 10 hips), the acetabular fragment was reoriented using fluoroscopy. We compared the difference between the planned and achieved position of the acetabular fragment and outcomes between both groups.

RESULTS

Two major complications occurred in four PAOs in the XR group only (first ten PAOs). The average absolute difference in planned and achieved lateral centre -edge angle (LCEA) and acetabular index (AI) was 1.2° ± 1.5° and 1.1° ± 2° for the EMN and 7° ± 6.1° and 6.3° ± 6.3° for the XR group (p = 0.02; p = 0.03). The average surgery duration was 183 ± 32 minutes for the EMN and 203 ± 42 minutes for the XR group (p = 0.19). At the last follow-up, the average Harris Hip Score (HHS) value was 88 ± 12 in the EMN and 86 ± 14 in the XR group (p = 0.84).

CONCLUSIONS

Our study indicates that PAO performed with EMN and PST seems to be a safe and reproducible procedure with a short learning curve. Additionally, navigated reorientation of the acetabular fragment is significantly more accurate than the fluoroscopic technique.

High frequency of labral pathology in symptomatic borderline dysplasia: a prospective magnetic resonance arthrography study of 99 patients

Labral pathology is seen in both dysplastic and borderline dysplastic hips. Periacetabular osteotomy (PAO) is the treatment of choice for dysplasia. However, some authors have suggested that borderline dysplastic hips with concurrent labral pathology should be treated arthroscopically. The purpose of this study was to investigate the frequency of labral pathology between dysplastic and borderline dysplastic hips, whether centre-edge (CE) angle is associated with labral pathology, and finally if pain and labral pathology are associated. Ninety-nine symptomatic patients (104 hips) scheduled for PAO were examined. Five patients were excluded due to complaints from multiple joints and four failed to show at 2-year follow-up. Five patients did not fill out questionnaires preoperatively. Hips were characterized as dysplastic (CE angle <20°) and borderline dysplastic (CE angle 20° ≤ 25°). A magnetic resonance arthrography was performed, and labral pathology was classified according to the Czerny classification. Association with the CE angle, the acetabular index (AI) and preoperative WOMAC pain score was tested by multiple linear regression. There was no significant difference in frequency of labral pathology when comparing the two groups. Across the cohort, 86 of 99 patients had labral pathology. The CE angle was associated with increasing severity of labral pathology, whereas the AI angle and preoperative pain were not associated with labral pathology. Decreased lateral coverage adversely loads the labrum, predisposing it to tears. We advocate reorienting the biomechanical forces through PAO, not arthroscopic treatment. Level of pain was not associated with labral pathology, suggesting that labral pathology may not alone explain the dysplastic pain complex.

Delays in diagnosis are associated with poorer outcomes in adult hip dysplasia

Background and Aims Developmental dysplasia of the hip is a common cause of osteoarthritis. Periacetabular osteotomy can restore femoral head coverage; however, it is reserved for patients with minimal articular degeneration. We examined the relationship between delays in diagnosis and outcomes. Methods We identified patients presenting to a hip specialist with a new diagnosis of hip dysplasia. The time taken between patients presenting to their general practitioner and attending the young adult hip clinic was established. Patients were stratified into Early, Moderate and Late Referral groups. Hip and SF-12 questionnaires were completed. Radiographs were graded according to the Tönnis classification system and the outcome following hip specialist review documented. Results Fifty-one patients were identified. Mean time from attending a general practitioner to review at the young adult hip clinic was 40.4 months. Lower hip and SF-12 scores, and higher radiological osteoarthritis grades were found in the Moderate and Late Referral groups. A higher proportion of the Moderate and Late Referral group underwent total hip arthroplasty rather than periacetabular osteotomy. Conclusion Delays in referring a patient to a hip specialist are associated with poorer outcomes. We propose pelvic radiographs are requested early by general practitioners to allow prompt diagnosis and referral to a hip specialist.

Arthroscopic Management of Dysplastic Hip Deformities: Predictors of Success and Failures With Comparison to an Arthroscopic FAI Cohort

BACKGROUND

Reports regarding arthroscopy for mild hip dysplasia have conflicting results.

HYPOTHESIS

Arthroscopy for borderline/mild hip dysplasia would lead to improved outcomes but be inferior to arthroscopy for femoroacetabular impingement (FAI).

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 88 hips (77 patients, 71% female; mean age, 33.9 years) with dysplastic radiographic findings were retrospectively reviewed at a mean follow-up of 26.0 months after hip arthroscopy. Specific procedures included labral repair (76%), labral debridement (23%), capsular repair/plication (82%), and femoral osteochondroplasty (72%). Radiographic parameters included lateral center-edge angle, neck-shaft angle, Tönnis angle, extrusion index, femoral head lateralization, and break in the Shenton line. Pre- and postoperative function were evaluated prospectively with the modified Harris Hip Score (mHHS), 12-Item Short Form Health Survey, and visual analog scale for pain. The results of the dysplastic cohort were compared with an age-matched cohort of 231 hips without radiographic dysplasia that underwent arthroscopic FAI correction during the study period (mean follow-up, 22.7 months).

RESULTS

The mean lateral center-edge angle was 20.8° (range, 8.7°-24.5°), and the mean Tönnis angle was 11.0° (range, 0°-22.2°). At the time of final follow-up, the dysplastic cohort demonstrated a mean mHHS of 81.3 with a mean 15.6-point improvement in mHHS, compared with 88.4 and 24.4 points, respectively, in the FAI cohort (P = .00044). The dysplastic cohort had 60.9% good/excellent results and 32.2% failures, compared with 81.2% good/excellent results and 10.5% failures for the FAI cohort (P < .01). Failure was defined as an mHHS ≤70 or eventual pelvic/femoral osteotomy or total hip arthroplasty. Dysplastic hips that underwent capsular plication and labral repair had greater good/excellent results (73%) and mean latest mHHS (85), as well as lower failure rates (18%) compared with the remainder of the dysplastic cohort (P < .05). Grade 4 chondral defects were predictive of lower scores (P = .02). There were no other statistically significant differences for outcomes regarding sex, age, or radiographic parameters (P > .05). There were no iatrogenic subluxations/dislocations.

CONCLUSION

Arthroscopic management of mild to moderate acetabular dysplasia had inferior good/excellent results and higher failure rates when compared with an FAI cohort; therefore, isolated arthroscopic procedures in this population should be cautiously considered. These results were independent of patient sex. Labral repair and capsular plication resulted in better clinical outcomes in this mildly dysplastic cohort.