Periacetabular osteotomy (PAO) is technically demanding with an assumed steep learning curve. This systematic review and meta-analysis evaluated how surgeon experience influences operative efficiency, perioperative morbidity, radiological correction, and conversion to total hip arthroplasty (THA) in developmental dysplasia of the hip (DDH). A systematic search of five databases identified studies comparing early with late PAO experience phases. Random-effects meta-analyses (Sidik-Jonkman with Hartung-Knapp adjustment) were performed for continuous (mean difference (MD)) and binary (odds ratios (ORs)) outcomes. Risk of bias was assessed with Risk Of Bias In Non-randomized Studies of Interventions (ROBINS-I), and certainty of evidence with Grading of Recommendations Assessment, Development, and Evaluation (GRADE). In all, seven studies (499 patients, 556 hips) were included. Late-phase PAOs had significantly shorter operative times (MD -74.58 minutes, 95% CI -136.52 to -12.65). No significant differences were found for blood loss, complications, THA conversion, or radiological correction. Heterogeneity was high for operating time and blood loss, and most studies showed moderate risk of bias. Surgeon experience substantially improves operative efficiency in PAO, while complications, blood loss, radiological accuracy, and early THA conversion appear largely unaffected, likely reflecting structured supervision and high-volume training environments. The lack of significant differences in complications and radiological correction suggests that structured mentorship and centralized hip preservation programmes may mitigate early-phase risk. Standardized, prospective studies are needed to define proficiency thresholds and optimize training in hip preservation surgery.

The Literature Shows Heterogeneity and Promise for the Role of Hip Arthroscopy Combined With Periacetabular Osteotomy for Dysplastic Patients, But Nuanced Decision Making and Further Research Are Required

Periacetabular osteotomy of the hip: an 8-year follow-up of 96 consecutive cases.

Long-term prospective data on periacetabular osteotomy (PAO) from Middle Eastern populations are limited. This study evaluated ≥ sevenyear clinical, functional, and radiographic outcomes following PAO and identified predictors of survivorship. Thirty-six consecutive patients (34.6 ± 7.2 years; 78% female) undergoing PAO (2014-2018) were prospectively followed. Inclusion required symptomatic dysplasia with Tönnis 0-2. Outcomes included HHS, WOMAC, HOS, SF-36, radiographic parameters (LCEA, AI), complications, and THA conversion. Reliability, multivariate regression, and Kaplan-Meier analyses were performed. At 7.8 ± 1.2 years, HHS improved from 63.5 ± 11.2 to 89.6 ± 7.8 (p < 0.001). LCEA increased from 16.2 ± 4.3° to 31.8 ± 3.9° and AI decreased from 22.8 ± 5.1° to 7.2 ± 3.6°. ICC for measurements was 0.92. Complications occurred in 16.7% (mostly minor). THA conversion was 5.6%, both with preoperative Tönnis 2 and correction < 12°. Magnitude of LCEA correction independently predicted HHS improvement (β = 0.41, p < 0.01). PAO achieved durable correction and sustained functional improvement with low THA conversion at mid- to long-term follow-up. Preoperative cartilage status and adequacy of correction are key determinants of outcome.

Return to Function Implications After Periacetabular Osteotomy.

Evaluation of periacetabular osteotomy in patients with hip dysplasia: an investigation of adverse events, functional performance, patient-reported outcomes and radiographic measurements (PhD Academy Award).

PurposeFocal labral ossification is a recognized radiographic finding in developmental dysplasia (DDH) and is typically regarded as a chronic lesion resulting from excessive stress on the chondro‐labral junction. The necessity for direct surgical intervention at the time of periacetabular osteotomy (PAO) for these ossifications remains a subject of debate. This study aimed to explore the natural course of pre‐existing focal labral ossifications following isolated PAO in adolescents and adults, hypothesizing that biomechanical correction alone would facilitate the spontaneous resolution of this focal labral metaplasia.MethodsA retrospective observational subgroup analysis of an institutional database identified a single treatment group who underwent isolated PAO for symptomatic DDH in adolescents and adults between January 2022 and November 2024. Pre‐ and 1‐year postoperative radiographs were independently assessed for the status of the labral ossification. Radiographic parameters of acetabular coverage and validated patient‐reported outcome measures (PROMs) were compared between hips with and without ossification. Multivariable regression analysis was performed to identify factors associated with labral ossification.ResultsOf 389 hips undergoing PAO, 41 (10%) demonstrated preoperative labral ossification. Baseline PROMs and most radiographic parameters were comparable between hips with and without ossification, although posterior coverage was significantly reduced in the ossification group. At 1‐year follow‐up, 37 of 41 hips (90%) showed complete radiographic resolution of labral ossification, two hips (5%) demonstrated partial regression and two hips (5%) remained unchanged. Multivariable analysis identified a mild association between posterior coverage and the presence of ossification, while no associations were found with activity level or PROMs.ConclusionIsolated PAO was found to be strongly associated with spontaneous remission of focal rim ossification in the vast majority of dysplastic hips within 1 year after surgery. These findings challenge the concept that focal rim ossifications represent irreversible degenerative pathology and instead suggest that they are a more appropriately interpreted as a metaplastic adaptation, indicating a remodeling potential of the chondro‐labral junction following biomechanical correction alone. Routine surgical treatment of chronic labral ossifications at the time of PAO may therefore be unnecessary.Level of EvidenceLevel III.

Complex hip deformities after Legg-Calvé-Perthes disease are characterized by an enlarged, asymmetrically deformed femoral head, ashort femoral neck, ahigh-riding greater trochanter, and secondary acetabular dysplasia. These features lead to intra- and extra-articular impingement, instability, abductor weakness, and early osteoarthritis. Conventional osteotomies or isolated acetabular reorientations do not directly address the femoral head deformity and, therefore, show limited results. Detailed analysis of the vascular anatomy enabled the development of intracapital osteotomy with central segment resection, without significantly compromising femoral head perfusion. Since 2001, this procedure, often combined with periacetabular osteotomy (PAO), has been used to restore sphericity and joint stability. Early data demonstrate significant radiological and functional improvements. Despite its technical complexity, the procedure is considered apromising option; long-term and multicenter studies are warranted.

Validated patient-reported outcome measures (PROMs) play a crucial role in assessing the outcome of any intervention, including hip preservation surgery. This study aims to evaluate floor and ceiling effects, which indicate data capture limitations, of the International Hip Outcome Tool-12 (iHOT-12) in patients undergoing hip preservation surgery. Data from the UK's Non-Arthroplasty Hip Registry (NAHR) were analyzed. Patient demographics, surgical details, and iHOT-12 scores were collected. Floor and ceiling effects were assessed using three definitions: absolute minimum or maximum scores, scores within 10% of the minimum or maximum, and scores within one minimal clinically important difference (MCID) of the minimum or maximum. Analyses were performed for patients undergoing hip arthroscopy and periacetabular osteotomy (PAO), as well as for male and female subgroups and by iHOT-12 domain. 8,408 patients (7,081 hip arthroscopy, 1,327 PAO) were included. At 26 to 52weeks, a ceiling effect was observed in 15-22% of patients, indicating limited data capture. A floor effect was present in 9-15% of patients at baseline indicating possible limited data capture in pre-operative patients. Male and female patients had similar ceiling effects at 52weeks, but females exhibited a higher risk of a floor effect at baseline. The sport and recreational domain was most susceptible to floor effects at baseline, and the job-related concerns domain was most susceptible to ceiling effects at follow-up. The study demonstrates the presence of floor and ceiling effects in the iHOT-12 for patients undergoing hip preservation surgery. The floor and ceiling effects were similar between patients undergoing hip arthroscopy or PAO. The study also suggests that some patients may experience greater improvement than reflected in post-operative iHOT-12 scores. Future research should focus on identifying patients at risk of floor and ceiling effects and explore modifications to PROMs to enhance their accuracy and utility.

Magnesium has been shown to reduce postoperative pain scores and opioid use in select orthopedic patient populations with a satisfactory safety profile. The objective of the MAGNA-PAO clinical trial is to observe and quantify the efficacy of magnesium as an adjuvant for postoperative analgesia following periacetabular osteotomy (PAO). Sixty-four patients will be randomly allocated to two groups: peri-operative pain protocol with or without adjuvant intra operative intravenous magnesium. The primary outcomes include visual analog score (VAS) pain scores over the first seven postoperative days and the amount of opioid medications used, expressed as morphine milligram equivalents (MME) and number of tablets, postoperatively. Secondary outcome measures include Patient Reported Outcomes Measurement Information System (PROMIS) and modified Harris Hip Score (mHHS) scores. This article will discuss the rationale, objective, and in-depth methodology of the MAGNA-PAO clinical trial. The results of the clinical trial could minimize postoperative pain and reduce the usage of post-operative narcotic medications.Clinical Trial Registration: The ClincialTrials.gov identifier is NCT05947760.

Background/Objectives: Curved periacetabular osteotomy (CPO) is an effective joint-preserving procedure for osteoarthritis of the hip; however, postoperative weight-bearing restrictions may influence muscle quality and functional recovery. This study aimed to examine longitudinal changes in muscle mass, muscle quality assessed by phase angle (PhA), and physical function after CPO and explored their postoperative interrelationships. Methods: This prospective longitudinal study included 35 female patients (mean age 34.9 ± 13.4 years) undergoing CPO. Assessments were conducted preoperatively, at full weight-bearing (FWB), and 12 months postoperatively. Lower-limb muscle mass and PhA were measured using multifrequency bioelectrical impedance analysis. Physical function was evaluated using Timed Up and Go (TUG), body weight-normalized ground reaction force during sit-to-stand (F/w), and operated-side weight-bearing capacity. Results: Operated-side muscle mass decreased at FWB and partially recovered by 12 months. In contrast, PhA declined markedly at FWB on the operated side (5.21 ± 0.69° to 4.15 ± 0.67°, p < 0.001) and remained significantly lower than baseline at 12 months. Functional measures declined during restricted loading and recovered to levels comparable to baseline by 12 months. At FWB, PhA was independently associated with TUG, F/w, and power generation indices. The reduction in PhA was greater than that observed for muscle mass, and contralateral PhA also declined. Conclusions: CPO is associated with a transient decline in muscle quality and functional performance during postoperative loading restriction. Although functional measures recover within 12 months, muscle quality remains partially impaired. Early strategies aimed at preserving muscle quality may support postoperative recovery.

Periacetabular osteotomy (PAO) is a widely used procedure to treat developmental dysplasia of the hip (DDH) in adults. Traditional bone wax cannot be absorbed on the osteotomy surface when bleeding ceases. This study aimed to evaluate the hemostatic efficacy and safety of a novel absorbable bone wax for PAO. In this prospective, randomized, single-blinded, parallel, positive-controlled clinical trial, 70 patients with DDH treated by PAO were enrolled between October 2020 and October 2022. During the operation, the novel absorbable bone wax or the conventional bone wax was used to stanch blood exudation from the osteotomy surface randomly. The primary outcome was hemostasis time. The secondary outcomes included osteotomy surface healing time, blood parameters, and absorbability of the novel bone wax. A 2-year follow-up of the enrolled patients was then conducted. The follow-up results revealed that the hemostasis time was not significantly different between the two groups (P > 0.05). Moreover, no statistically significant differences were observed between the two groups in blood parameters tests at 3 days or 2 weeks post-surgery (P > 0.05). Telephone follow-ups at 2 and 6 weeks post-surgery identified no patients with poor wound healing or other adverse effects. Postoperative imaging demonstrated absorbability of the novel bone wax and bone healing of the pubic osteotomy. Absorbable bone wax which is a novel type of bone wax material, is safe and reliable for the hemostasis of osteotomy surfaces in the human body. The results support the clinical application and popularization of this novel absorbable bone wax in surgical procedures. Chinese Clinical Trial Registry (ChiCTR2000033242). Registered 25/05/2020.

Periacetabular osteotomy (PAO) is widely used to treat symptomatic hip dysplasia; however, the long-term effect of age at PAO on patient-reported outcome measures (PROMs) remains controversial. We aimed to determine whether age at PAO influences long-term PROMs. We conducted a retrospective cohort study involving 111 patients (126 hips) who had a mean follow-up of 19.5 years after PAO. The Forgotten Joint Score-12 (FJS-12) and Oxford Hip Score (OHS) were collected via postal survey. Patients were clustered into three groups using k-means clustering based on PROMs. A cluster with the highest scores-exceeding the patient acceptable symptom state threshold for FJS-12 and showing differences beyond minimal clinically important difference-was defined as "excellent." The remaining native hips and those converted to total hip arthroplasty (THA) were grouped as controls. Multivariable logistic regressions identified indicators of excellent outcomes. The "excellent" group (n = 64) had mean scores of FJS-12: 84.1 and OHS: 46.6. The control group (n = 93) included native hips with lower PROMs and 31 hips converted to THA. The mean age at PAO was 41 years in the excellent group and 44 years in controls (P = 0.133). Age at PAO was not a negative indicator of excellent outcomes (adjusted odds ratio (OR) per year, 1.02; 95% confidence interval (CI), 0.98 to 1.06). Using Tönnis Grade 1 as a reference, Grade 0 was a positive indicator (OR 3.35; 95% CI, 1.16 to 10.5), and Grade 2 was a negative indicator (OR 0.13; 95% CI, 0.04 to 0.37). Higher body mass index (BMI) was also a negative indicator (OR per unit, 0.83; 95% CI, 0.73 to 0.94). Age at PAO does not reduce the likelihood of excellent 20-year PROMs in native hips. Therefore, age alone should not be a limiting factor when considering PAO in appropriately selected patients.

Importance of Labral Injury in Periacetabular Osteotomy: Implications for Joint Preservation in Developmental Dysplasia of the Hip.

Increased Risk of Stress Fractures Following Second-Side Periacetabular Osteotomy: A Retrospective Cohort Study.

Reorientation of the acetabulum through a periacetabular osteotomy is 1 of the increasingly popular treatment modalities for hip dysplasia. The purpose of this study is to assess the timing of recovery, return to previous activities, driving and painless full weight-bearing for non-athlete patients undergoing a periacetabular osteotomy for borderline or true hip dysplasia. Patients who underwent a periacetabular osteotomy between 2018 and 2022 were eligible for enrollment. Patients with at least 2 years of follow-up, with complete radiological and clinical data were included. The following parameters were evaluated on pelvic radiographs: lateral centre-edge angle, anterior centre-edge angle, acetabular inclination angle, extrusion index, anterior wall index, and joint space width at the narrowest point. A total of 40 patients were included. 4 patients were male (10%), average age was 24 years. Patients regained their preoperative activity levels in an average of 4.5 months (range 2-12 months). The average time for patients to walk without pain while bearing full weight was 3.4 months (range 2-5 months). Mean preoperative lateral centre-edge angle improved from 8.7° to 35.0°, while their mean preoperative anterior centre-edge angle increased from 11.6° to 33.1°. All clinical scores improved significantly when compared to their preoperative values. Radiographic parameters and functional outcomes improve with periacetabular osteotomy. Non-athletic, moderately active patients returned to their pre-surgery activity levels on average 4.5 months after surgery and were able to walk without pain after an average of 3.4 months. A progressively narrowing preoperative joint space translates into longer pain-free full weight-bearing times.

Periacetabular osteotomy (PAO) is a well-established surgical technique that is used to enhance femoral head coverage in patients with developmental dysplasia of the hip (DDH). Although 2-dimensional radiographs remain standard for evaluating acetabular coverage, 3-dimensional (3D) computed tomography (CT)-based measurements using acetabular sector angles (ASAs) provide higher precision. This study aimed to analyze acetabular coverage through ASA parameters and to investigate the long-term clinical outcomes following PAO. This retrospective study included 35 hips from 29 patients who underwent PAO for DDH. Radiographic measurements comprised the T.nnis angle, Sharp angle, lateral center-edge angle (LCEA) and anterior center-edge angles (ACEA), anterior center margin angle (ACMA), extrusion index, and hip lateralization index (HLI). The CT-derived variables included acetabular version (AV), anterior ASA (AASA), posterior ASA (PASA), and horizontal ASA (HASA). Clinical outcomes were assessed by using the Harris Hip Score (HHS). The mean patient age was 19.9 years, with a mean follow-up period of 8.7 years. Significant postoperative improvements were noted in AASA, HASA, T.nnis angle, Sharp angle, extrusion index, AV, LCEA, ACEA, acetabular depth, and HHS (all P < .05). No significant differences were observed in PASA, HLI, or ACMA. The HHS showed a negative correlation with HLI (P < .05) and a positive correlation with postoperative LCEA (P < .01). Patients with postoperative LCEA < 25Åã demonstrated superior functional outcomes compared with those with LCEA ≥ 35Åã (P = .034). Eight patients experienced complications, and 2 patients required conversion to total hip arthroplasty. The PAO provides durable long-term results in the management of DDH. Incorporating 3D ASA analysis enhances both preoperative planning and postoperative evaluation, contributing to more precise acetabular reorientation and improved clinical assessment Cite this article as: Güneş Z, Çağlar Ö, et al. Assessment of 3-dimensional acetabular coverage based on acetabular sector angles following periacetabular osteotomy: long-term clinical, radiological, and survivorship outcomes. Acta Orthop Traumatol Turc., 2026; 60(1), 0334, doi: 10.5152/j.aott.2026.25334.

Letter to the Editor: What Factors and Patient-reported Outcome Measures Are Associated With Stress Fracture After Periacetabular Osteotomy?

Bilateral hip arthroscopy (HA) for femoroacetabular impingement syndrome (FAIS) has demonstrated favorable short-term outcomes. However, the long-term results remain unclear and warrant further investigation. To compare 10-year patient-reported outcomes (PROs), clinically significant outcomes (CSOs), and reoperation-free survivorship between bilateral and unilateral HA. It was hypothesized that both groups would demonstrate comparable PROs, CSO achievement, and survivorship. Cohort study; Level of evidence, 3. A prospective repository was retrospectively reviewed to identify patients undergoing bilateral HA for FAIS between January 2012 and January 2015 with 10-year follow-up. Patients were propensity-matched 1:1 to unilateral HA patients controlling for age, sex, body mass index, and Tönnis grade. Exclusions included revision HA, concomitant procedures, congenital hip disorders, non-FAIS pathologies, staged periacetabular osteotomy, Tönnis grade >1, and missing 10-year follow-up. Hip Outcome Score (HOS) subscale for Activities of Daily Living and the HOS Sports Subscale (HOS-SS), International Hip Outcome Tool, modified Harris Hip Score, and visual analog scale (VAS) for pain/satisfaction were collected. Minimal clinically important difference (MCID), Patient Acceptable Symptom State (PASS), and reoperation-free survivorship were compared. Improvements from baseline to 10 years were correlated between hips. Analysis of variance evaluated differences based on bilateral HA timing. A total of 80 hips in 40 patients with bilateral HA were matched to 80 hips in 80 patients with unilateral HA. Mean follow-up was 10.4 ± 0.6 years. PROs at all time points were comparable. MCID and PASS achievement rates were similar between groups. Reoperation-free survivorship was comparable (P = .70). Change in index hip scores positively correlated with contralateral hip changes. A 0- to 3-month interval demonstrated superior preoperative HOS-SS compared with 6 to 12 months, whereas a 3- to 6-month interval demonstrated superior 10-year VAS-Pain score compared with 0 to 3 months. Bilateral HA achieved long-term outcomes and reoperation-free survivorship comparable to those of unilateral HA. Index and contralateral hip outcomes were positively correlated. Shorter intervals between procedures were associated with better preoperative function, whereas intermediate intervals were associated with lower long-term pain, but finding this requires further investigation with larger sample sizes.

Abstract In patients with borderline hip dysplasia (BHD), radiographic and clinical variables influence in the decision to treat the painful hip with periacetabular osteotomy (PAO) versus isolated hip arthroscopy (iHA). The purpose of this study focusing on adolescent and young adult patients with BHD was to evaluate the surgical decision-making process at a specialist hip centre and to identify a combination of variables that predict treatment with PAO or iHA. Accordingly, patient demographics, baseline radiographic variables, and several clinical variables were recorded for 68 patients treated surgically for BHD. While a number of variables were associated with treatment decision, regression analysis showed that sex, femoral version, femoro-epiphyseal acetabular roof (FEAR) index, and anterior centre edge angle were principal predictors of treatment. The PAO versus Arthroscopic Treatment of the Hip (PATH) score was defined (one point for anterior centre edge angle &amp;lt; 25°, one point for FEAR index &amp;gt; − 3°, and one point for femoral version ≥15°). Among patients without prior contralateral hip surgery, males were treated with iHA unless they had a maximum PATH score of 3 (PAO), while females with PATH score ≥ 2 were universally treated with PAO. Females with PATH score ≤ 1 were variably treated with PAO or iHA, underscoring the need for clearer guidelines regarding indications and improved microinstability testing in this subgroup.