Periacetabular Osteotomy Group Research Articles

The Otto Aufranc Award: Does Hip Arthroscopy at the Time of Periacetabular Osteotomy Improve the Clinical Outcome for the Treatment of Hip Dysplasia? A Multicenter Randomized Clinical Trial

BackgroundA periacetabular osteotomy (PAO) is often sufficient to treat the symptoms and improve quality of life for symptomatic hip dysplasia. However, acetabular cartilage and labral pathologies are very commonly present, and there is a lack of evidence examining the benefits of adjunct arthroscopy to treat these. The goal of this study was to compare the clinical outcome of patients undergoing PAO with and without arthroscopy, with the primary end point being the International Hip Outcome Tool-33 at 1 year. MethodsIn a multicenter study, 203 patients who had symptomatic hip dysplasia were randomized: 97 patients undergoing an isolated PAO (mean age 27 years [range, 16 to 44]; mean body mass index of 25.1 [range, 18.3 to 37.2]; 86% women) and 91 patients undergoing PAO who had an arthroscopy (mean age 27 years [range, 16 to 49]; mean body mass index of 25.1 [17.5 to 25.1]; 90% women). ResultsAt a mean follow-up of 2.3 years (range, 1 to 5), all patients exhibited improvements in their functional score, with no significant differences between PAO plus arthroscopy versus PAO alone at 12 months postsurgery on all scores: preoperative International Hip Outcome Tool-33 score of 31.2 (standard deviation [SD] 16.0) versus 36.4 (SD 15.9), and 12 months postoperative score of 72.4 (SD 23.4) versus 73.7 (SD 22.6). The preoperative Hip disability and Osteoarthritis Outcome pain score was 60.3 (SD 19.6) versus 66.1 (SD 20.0) and 12 months postoperative 88.2 (SD 15.8) versus 88.4 (SD 18.3). The mean preoperative physical health Patient-Reported Outcomes Measurement Information System score was 42.5 (SD 8.0) versus 44.2 (SD 8.8) and 12 months postoperative 48.7 (SD 8.5) versus 52.0 (SD 10.6). There were 4 patients with PAO without arthroscopy who required an arthroscopy later to resolve persistent symptoms, and 1 patient from the PAO plus arthroscopy group required an additional arthroscopy. ConclusionsThis randomized controlled trial has failed to show any significant clinical benefit in performing hip arthroscopy at the time of the PAO at 1-year follow-up. Longer follow-up will be required to determine if hip arthroscopy provides added value to a PAO for symptomatic hip dysplasia.

The Use of Combined Hip Arthroscopy and Periacetabular Osteotomy for Hip Dysplasia Is Increasing and Has Low Complication Rates

PurposeTo analyze annual use of hip arthroscopy (HA) and Bernese periacetabular osteotomy (PAO) for the treatment of hip dysplasia (HD), as well as post-operative outcomes, including ipsilateral reoperations. MethodsNinth and Tenth Revision codes of the International Classification of Diseases were used to query the PearlDiver™ Mariner database from January 2010 through January 2022 to identify patients aged 10-59 years who had a presenting diagnosis of HD and subsequently underwent: 1) HA; 2) PAO; or 3) combined HA and PAO (HA-PAO, defined as PAO on the same day or within 28 days following HA). We analyzed annual rates for each treatment, as well as rates of post-operative emergency visits, readmissions and five-year ipsilateral secondary operations (determined via Kaplan-Meier analysis). ResultsThere were 32,068 patients who underwent surgical treatment of HD. For HA, PAO, and HA-PAO, there were 29,700, 2,083, and 285 patients, respectively. All operations had the highest percent-increase from 2015 to 2016. HA and HA-PAO peaked in 2021, while PAO peaked in 2019. For HA, PAO, and HA-PAO, the majority of cases were performed in female patients and patients aged 30-49 years, 10-19 years, and 10-29 years, respectively. The five-year incidence of ipsilateral secondary operations, which include revision HA, PAO, or conversion to total hip arthroplasty, was 9.2% (95% CI: 8.6%- 9.8%) in the HA group and 6.5% (95% CI: 4.1%- 8.8%) in the PAO group. Combining HA with PAO resulted in so few secondary operations that Kaplan-Meier analysis was infeasible. The PAO cohort had the highest 30-day emergency visit and 90-day readmission rates, with infection as the most common cause for readmission. ConclusionHA is more frequently performed than PAO for hip dysplasia. HA-PAO is rising at the greatest rate, demonstrating fewer complications and reoperations.

Periacetabular osteotomy with andwithout concomitant arthroscopy: a systematic review ofevidence onpost-operative activity levels andreturn to sport.

The purpose of this systematic review is to (i) compare post-operative activity levels after periacetabular osteotomy (PAO) versus PAO + HA (concomitant PAO and hip arthroscopy) using patient-reported outcomes that specifically assess activity and sports participation [Hip Disability and Osteoarthritis Outcome Score-Sport and Recreation subscale (HOOS-SR), University of California Los Angeles (UCLA) activity score, Hip Outcome Score-Sport-Specific Subscale (HOS-SSS)] and (ii) compare post-operative return to sport (RTS) data between PAO and PAO + HA groups. A systematic review of literature was conducted on 1 June 2023, utilizing PubMed, Cochrane and Embase (OVID). Articles were screened for inclusion using specific inclusion and exclusion criteria. Twenty-six out of 1610 articles metall inclusion criteria, without meeting any exclusion criteria. In the 12 studies containing only subjects who underwent PAO alone, 11 demonstrated an average score improvement in UCLA, HOOS-SR or HOS-SSS post-operatively (P < 0.05). In the three studies containing subjects who underwent PAO with concomitant HA, significant improvements were seen in the HOS-SS and UCLA scores (P < 0.05). In the five studies that directly compared UCLA, HOS-SSS and HOOS-SSS scores between PAO groups and PAO + HA groups, all demonstrated statistically significant improvement post-operatively (P < 0.05). The rate of RTS ranged from 63% to 90.8% among PAO studies and was found to be 81% in the single PAO + HA study that assessed RTS. When performed in patients with intra-articular pathology, concomitant PAO + HA may provide similar sport-related outcomes to PAO alone in patients without intra-articular pathology.

No Difference in Patient-Reported Outcomes for Periacetabular Osteotomy and Hip Arthroscopy With Capsular Plication in the Setting of Borderline Hip Dysplasia: A Propensity-Matched Multicenter Study With Minimum 5-Year Follow-Up

To compare minimum 5-year patient-reported outcome measures after hip arthroscopy (HA) and periacetabular osteotomy (PAO) for borderline hip dysplasia. Hips with a lateral center-edge angle (LCEA) between 18° and less than 25° that underwent either PAO or HA were selected from 2 institutions. The exclusion criteria were as follows: LCEA less than 18°, Tönnis osteoarthritis grade greater than 1, prior hip surgical procedures, active inflammatory disease, Workers' Compensation, and concomitant surgery. Patients underwent propensity matching based on age, sex, body mass index, and Tönnis osteoarthritis grade. Patient-reported outcome measures included the modified Harris Hip Score, as well as calculation of the minimal clinically important difference, patient acceptable symptom state, and maximum outcome improvement satisfaction threshold. Preoperative radiographic predictors included comparison of the Femoro-epiphyseal Acetabular Roof index and ligamentum teres lesions. A total of 28 PAO patients underwent propensity matching to 49 HA patients. The 2 groups were similar in terms of mean age, sex, preoperative body mass index, and LCEA. The PAO group had a longer mean follow-up period (95.8 months vs 81.3 months, P= .001). The mean Femoro-epiphyseal Acetabular Roof index was significantly lower preoperatively in the HA group (P < .001). The 2 groups showed similar and significant improvements in the mean modified Harris Hip Score from preoperatively to latest follow-up (P < .001). The relative risk of subsequent surgery in the PAO group was 3.49 (P= .024), mostly attributed to hardware removal (25%). The revision rate was 3.6% in the PAO group and 8.2% in the HA group (P= .65). One patient in the PAO group required revision HA for intra-articular adhesions. Three of the patients requiring revision in the HA group underwent PAO because of persistent pain, and one underwent revision HA alone. Conversion to total hip arthroplasty was required in 1 patient in the HA group and no patients in the PAO group. Both PAO and HA with capsular plication provide borderline hip dysplasia patients with clinically significant improvements and low revision rates at a minimum of 5 years postoperatively. Level III, retrospective, comparative therapeutic trial.

The Effects of Arthroscopic Labral Repair on Patient-Reported Outcomes in the Setting of Periacetabular Osteotomy

Background: It is currently unknown whether the addition of arthroscopic labral repair in the setting of periacetabular osteotomy (PAO) provides any clinical benefit. Purpose/Hypothesis: The purpose of this study was to compare outcomes of patients who underwent arthroscopic labral repair concomitantly with PAO versus patients who underwent PAO alone. We hypothesized that there would be no difference in patient-reported outcome measures (PROMs) between the cohorts. Study Design: Cohort study; Level of evidence, 3. Methods: Patients undergoing PAO from a single-center prospective hip preservation registry were eligible for this study if they completed pre- and postoperative PROMs (minimum, 1 year). PROMs were collected at 1 year, 2 years, and latest follow-up at 6.05 years for PAO group and 4.2 years for scope/PAO group. The study group consisted of 53 patients who underwent arthroscopic labral repair at the time of their PAO, and the comparison group consisted of 170 patients who underwent PAO alone. A subset of the PAO group who had radiologic evidence of a detached labral tear (n = 33) was also compared with the rest of the PAO-alone group. PROMs were compared at every time point for both groups as well as the subset of patients who underwent PAO alone despite a labral tear. Results: The mean follow-up of all patients was 2 years (range, 1-6 years). Overall, 85.2% of the PAO group and 85.7% of the scope/PAO group met the minimal clinically important difference for either the modified Harris Hip Score (mHHS) or the International Hip Outcome Tool (iHOT-33) at the most recent follow-up. There was no difference in improvement between groups (mHHS, P = .670; iHOT-33, P = .944). Patients who had a radiologically diagnosed detached labral tear and underwent PAO alone had no difference in outcomes when compared with the rest of the PAO cohort (mHHS, P = .981; iHOT-33, P = .909). Conclusion: There was no significant benefit measured by PROMs at follow-up for concomitant arthroscopic labral repair in the setting of PAO.

Use of Anatomic Radiographic Horizons for the Lateral Center-Edge Angle in the Classification of Hip Dysplasia

Background: The lateral center-edge angle of Wiberg (LCEA) and Tönnis angle (TA) rely on a “horizon” that functions as a reference point for measurements of hip dysplasia on weightbearing anteroposterior pelvis radiographs. There are 3 different horizons that are currently utilized depending on surgeon preference: (1) a line parallel to the radiographic floor (F), (2) a line that connects the inferior portions of the acetabular teardrops (ATs), or (3) a line that connects the ischial tuberosities (ITs). It is imperative to accurately assess the degree of hip dysplasia on initial workup to select the appropriate surgical intervention. Purpose: To assess how the choice of a radiographic horizon affects the measurements of the LCEA and TA. The secondary purpose was to assess how the horizon affected the classification of hips as either normal, borderline dysplastic, or dysplastic. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: The LCEA and TA were measured on all preoperative weightbearing anteroposterior pelvis radiographs for 186 consecutive patients who underwent hip preservation surgery between February 2016 and November 2020 (140 hip arthroscopic procedures, 46 combined hip arthroscopic procedures with periacetabular osteotomy), 3 times per hip, each time using an F, AT, and IT horizon. The Student t test was used to analyze the differences in the measurements of the LCEA and TA, and discordance rates in the dysplasia classification between horizons were quantified. Results: For the entire study population, the mean LCEAF (23.4°± 7.4°) was significantly greater than the mean LCEAIT (23.1°± 7.2°) (95% CI, −0.634 to −0.003; P = .047) and mean LCEAAT (23.0°± 7.1°) (95% CI, −0.723 to −0.139; P = .004). There was no difference between the LCEAIT and LCEAAT (95% CI, −0.305 to 0.080; P = .251). When stratified by hip arthroscopic surgery, the mean LCEAF (26.3°± 5.6°) was significantly greater than the mean LCEAAT (25.8°± 5.3°) (95% CI, −0.845 to −0.162; P = .004). Overall, there was a 17.7% and 18.3% discordance rate in the dysplasia classification using the LCEAIT and LCEAAT compared with the LCEAF, respectively. There were no statistically significant differences between the mean TAIT, TAAT, and TAF for the entire study population, the arthroscopic surgery group, and the combined arthroscopic surgery and periacetabular osteotomy group. Conclusion: There was no statistical difference between the AT and IT horizons for LCEA measurements. The dysplasia classification was in better agreement between the 2 anatomic horizons compared with the F horizon. The TA was not affected by changes in the horizon.

Comparison of modern periacetabular osteotomy for hip dysplasia with total hip arthroplasty for hip osteoarthritis-10-year outcomes are comparable in young adult patients.

ABSTRACTYoung adult patients with symptomatic acetabular dysplasia and marginal secondary osteoarthritis can be faced with the decision to either undergo periacetabular osteotomy (PAO) to relieve symptoms and slow osteoarthritis progression or wait until progression to more advanced disease and undergo total hip arthroplasty (THA). The decision can be difficult, and contemporary literature to guide these decisions is sparse. Therefore, we retrospectively assessed complication rate, survivorship and patient-reported clinical outcomes [modified Harris Hip score (mHHS), UCLA Activity score] in two, consecutive cohorts of patients aged 18–40 years that underwent either PAO for symptomatic acetabular dysplasia (mean age 28.9 years) or THA for advanced secondary osteoarthritis (32.5 years). PAO patients were followed for a mean of 10.5 years (8–19) and THA patients for 11.9 (8–17) years. Between PAO and THA groups, there were no differences in overall complication rate (4.7% versus 4.7%), non-revision reoperation rate (5.9% versus 2.3%, P = 0.37) or end-revision rate [7 (8.2%) PAOs converted to THA at mean 10.8 years versus 3 (7.0%) THAs revised at 6.2 years, P = 0.80]. Latest scores remained significantly improved from baseline in both the PAO (mHHS 86.1 versus 63.3, P < 0.001; UCLA 7.5 versus 6.9, P < 0.05) and THA (mHHS 82.6 versus 48.4, P < 0.001; UCLA 7.2 versus 4.6, P < 0.001) cohorts. Final scores were similar between groups (mHHS 86.1 versus 82.6, P = 0.46; UCLA 7.5 versus 7.2, P = 0.37). Clinical success [mHHS minimal clinically important difference (8) OR PASS (>70) at latest follow-up without end-revision] was achieved in 81.2% of PAO hips and 83.7% of THA hips (P = 0.72).

Pain and quality of life are impaired in adults with hip dysplasia undergoing periacetabular osteotomy: a systematic review and meta-analysis

Purpose: In adults with hip dysplasia (i) evaluate pre to post- operative changes in pain, function and quality of life following Periacetabular Osteotomy (PAO); (ii) evaluate differences in pain, function and quality of life in those undertaking PAO and healthy controls; and (iii) evaluate differences in pain, function and quality of life in those with mild versus severe dysplasia, as defined by the Lateral Centre Edge Angle (LCEA) LCEA. Methods: A comprehensive, reproducible search strategy was performed on the following databases MEDLINE CINAHL, EMBASE, Sports Discuss, and PsychINFO from inception until 11th July 2019. Studies were eligible for inclusion if they used a hip-specific patient-reported outcome measure (PROM) and reported Level IV evidence or above. Participants: People aged 15 years and older with hip dysplasia undertaking PAO. Intervention: Studies utilising PAO surgery as primary intervention for Hip Dysplasia. The terms “Bernese Osteotomy” and “Ganz Osteotomy” were considered interchangeable with ‘Periacetabular Osteotomy’. Studies were ineligible if the PAO was reported to be a ‘rotational’ or ‘”curved” procedure. Comparator: Studies using sham treatment, no treatment or other treatment as the comparator/control treatment were included. We also included studies where no control group was present. Outcomes: Primary outcomes of interest were pain, function and quality of life. The hip-specific PROMs included: Hip Dysfunction and Osteoarthritis Outcome Score (HOOS), Western Ontario and McMaster universities osteoarthritis Index (WOMAC), the International Hip Outcome Tool (iHOT), the Copenhagen Hip and Groin Outcome Score (HAGOS), NAHS (Non-arthritic Hip Score), and the Oxford Hip Score (OHS). A modified version of the Downs and Black checklist was used to assess the quality of included studies. Quality Evaluation and Data Extraction was performed by two independent reviewers with any disagreements discussed in a consensus meeting and an independent arbitrator was employed when consensus could not be met. A hierarchy of PROMs was decided on between authors to prioritise data extraction where more than one had been used. The order of the hierarchy was based on the established level of validity and reliability of the PROM for young people with hip pain, and applicability to people with hip dysplasia undergoing PAO. In order of selection the hierarchy was HOOS, WOMAC, IHOT, HAGOS, NAHS, OHS. Results: The search yielded 4065 titles and abstracts for screening, with 51 studies included in the final analyses. The methodological quality scores ranged from 50% to 94%, with an overall mean (SD) rating of 71% (11.6%). Sample sizes of the PAO groups ranged from 16 patients to 391 patients. The ages for patients in the included studies ranged from 20 years to 45 years. All included studies used a PROM. Seventeen studies used the HOOS, 34 studies used the WOMAC, five studies used the iHOT, 4 studies used the HAGOS and 3 studies used the NAHS.Two studies, one prospective cohort study and a retrospective cohort study, compared subscale scores (pain, symptoms, activities of daily living (ADL), sport & recreation, and quality of life) pre-operatively versus post-operatively. For the pain subscale (Fig. 1) a significant improvement was found between pre-surgery and the one-year timepoint (SMC (95% CI): 1.50; 1.33 to 1.67) and this improvement was maintained at the two-year timepoint (1.43; 1.16 to 1.70). This also occurred in the symptoms subscale at one-year (1.21; 1.06 to 1.36) and two-years (1.08; 0.82 to 1.34); ADL at one-year (1.21; 1.06 to 1.36) and two-years (1.11; 0.98 to 1.23); sport & recreation at one-year (1.41; 1.25 to 1.57) and two-years (1.32; 0.88 to 1.75); and quality of life at one-year (1.38; 1.22 to 1.54) and two-years (1.31; 1.04 to 1.57). These results provide low-level evidence that patients experience clinical improvements across all subgroups at one year after PAO, compared to pre-surgery, and this is maintained at the two-year timepoint. Two studies compared outcomes between PAO patients and healthy participants, one high-quality prospective cohort study and one high quality cross-sectional study. Meta-analysis of the pre-operative time point showed significantly worse outcomes in the PAO group with large effect sizes across all subgroups. This included pain (Fig. 2) (SMD (95% CI): -3.84; -4.73 to -2.95), symptoms (-3.84; -4.36 to -3.29), ADL (-2.81, -3.89 to -1.74), sport & recreation (-3.47; -3.79 to -3.16), and quality of life (-4.10; -4.43 to -3.77). This result provides low-level evidence that PAO patients have significantly worse outcomes across all subgroups when compared to healthy participants. This occurs both pre-operatively and postoperatively and 6, 12 and 32 months. Conclusions: Before undergoing PAO surgery, adults with hip dysplasia have worse levels of pain, symptoms, ADL, sport and recreation and quality of life compared to healthy participants. These levels improve over two years following PAO, but do not reach the same level as their asymptomatic peersView Large Image Figure ViewerDownload Hi-res image Download (PPT)

Rectus-sparing approach to the periacetabular osteotomy in adolescents preserves hip flexion strength.

PurposeThe classic periacetabular osteotomy (PAO) approach can result in hip flexor weakness in adolescents. The rectus-sparing approach (PAO-RS) preserves the origin of the rectus femoris tendon which may prevent hip flexor weakness and improve functional outcome.MethodsThis is a prospective analysis of adolescents treated with a PAO or PAO-RS. The PAO group included 24 hips/21 patients (18 female, meanage 16 years (sd 4)); the PAO-RS group included ten hips (eight female, mean age 16 years (sd 1)). Preoperatively, the PAO group had decreased hip flexion strength compared with the PAO-RS group (83 Nm/kg versus 102 Nm/kg). A subset of PAO patients (n = 13 hips/12 patients, nine female, mean age 15 years (sd 3)) were matched for preoperative flexion strength to the PAO-RS group. Radiographic parameters, modified Harris hip score (mHHS), isokinetic hip strength and instrumented motion analysis preoperatively, six months and one-year postoperatively were compared.ResultsThere were no differences in preoperative deformity, postoperative correction or degree of correction between groups. Hip flexor strength decreased significantly at six months in the PAO group compared with the PAO-RS group (-35 Nm/kg versus -7 Nm/kg; p = 0.012), as did hip flexion pull-off power (1.33 W/kg PAO versus 1.76 W/kg PAO-RS; p = 0.010). Hip flexion strength improved from six months to one year in the PAO group, with no significant differences in strength at one year between groups (80 Nm/kg versus 90 Nm/kg). There were no differences between groups in mHHS any time point; both groups improved significantly postoperatively.ConclusionPreserving the rectus femoris may lead to improved short-term hip flexor strength and pull-off power. Further assessment at long-term follow-up is needed to determine if this strength leads to improved functional outcomes.Level of EvidenceII

OUTCOME OF SURGICAL TREATMENT IN PATIENTS WITH BORDERLINE ACETABULAR DYSPLASIA: A COMPARATIVE ANALYSIS OF HIP ARTHROSCOPY AND PERIACETABULAR OSTEOTOMY

Background:Optimal treatments of patients with borderline hip dysplasia, defined as LCEA 20°-25°, is controversial. These patients can have symptomatic impingement and/or instability. The optimal treatment of either hip arthroscopy (HA) alone or periacetabular osteotomy (PAO) (with/without hip arthroscopy) has not been established.Purpose:The purpose of this study was to evaluate surgical outcomes of patients with borderline hip dysplasia at a minimum of 2-year follow-up.Methods:A longitudinal cohort was utilized to identify patients with borderline acetabular dysplasia defined via prospective radiographic measurements. Demographics and radiographic measurements were recorded. Patient evaluation, diagnosis and treatment decisions (PAO v HA) were made by one treating surgeon. Outcome were assessed at baseline and a minimum 2 years postoperative. Descriptive and comparative statistics were performed. Failure was defined as reoperation, or failure to reach mHHS MCID (8 points) or PASS (mHHS <74).Results:Total of 113 hips were included at 4.7 years postoperatively (range 2.0-11.2 years). Overall, 76% were female and 42% of hips had PAO (65% combined with hip arthroscopy), while 58% had isolated hip arthroscopy (HA). For PAO group, mHHS improved from 57.9 to 82.8 postoperatively, compared to 62.6 to 84.0 for the HA group. Similarly, HOOS pain (PAO 48.2 to 79.1, HA 61.2 to 82.0) and HOOS Sports (PAO 36.5 to 73.0, HA 47.8 to 74.4) demonstrated similar improvements. Comparing the PAO and HA groups, the change in PRO was significantly greater for the PAO group for HOOS Pain (10.5 ±23.2, p=0.02) and HOOS ADL (9.4 ±20.5, p=0.04) which was primarily due to a lower baseline score (similar final score). No significant difference was detected for other PROs. Reoperations in the PAO group were 2% (1 hip arthroscopy) and 6% for hip arthroscopy group (3 hip arthroscopies, 1 PAO). The failure rate was 17% for PAO and 15% for HA (p=0.86).Discussion:Surgical outcomes at minimum of 2 years in patients with borderline hip dysplasia in selected patients undergoing PAO or hip arthroscopy were good. Significant differences in patient characteristics and radiographic parameters were present between hips indicated for PAO vs. HA emphasizing the need for careful diagnosis and treatment decision-making.

Development of a novel customized cutting and rotating template for Bernese periacetabular osteotomy

BackgroundBernese periacetabular osteotomy (PAO) has been shown to be applicable as a hip-preserving technique for the treatment of developmental dysplasia of the hip (DDH). The approach could be designed preoperatively using various types of reverse-engineering software and finite element analysis, but how to implement it in the actual PAO remains a challenge. This study examines and evaluates a solution to achieve higher accuracy when performing a PAO.MethodsA patient-specific cutting and rotating template was predesigned through computer-aided design (CAD) with three-dimensional (3D) modeling programs. The templates were then reproduced with rapid prototyping (RP) technology and used in the actual PAO. Finally, the clinical and radiographic effects were assessed and compared between the newly developed PAO and conventional PAO groups.ResultsThe customized cutting template fit well with the bone surface and served as a guide for surgeons as they slid the osteotome to the precise location that had been determined prior to surgery. A very similar acetabular fragment was reproduced, and no major complications occurred when performing the osteotomy along the edge of the cutting template. The acetabular fragment was then corrected to the predetermined position through one-off manipulation with the customized rotating template. The final position of the acetabular fragment in the new developed PAO group was highly consistent with the planned position, and the postoperative morphological parameters were consistent with the preoperative planned data compared to the conventional PAO group. The duration of the operation and the number of irradiation decreased significantly. The Harris hip score (HHS) and visual analogue scale (VAS) score improved significantly with the use of the new developed PAO.ConclusionsWe demonstrate that our system, which was based on CAD-RP technology, is feasible and could realize the predicted results accurately during the actual PAO.

Failed periacetabular osteotomy leads to acetabular defects during subsequent total hip arthroplasty.

Acetabular wall defects after periacetabular osteotomy (PAO) lead to technical difficulties when performing subsequent total hip arthroplasty (THA). There is no unified consensus regarding the solution for THA socket installation after PAO. In the current study, we performed computed tomography (CT)-based simulation of socket installation and evaluated the acetabular defect following THA after PAO and after primary osteoarthritis (OA). The study group comprised 55 patients (56 hips) who underwent THA after PAO. For the control group, after matching for age, sex, and Crowe classification, we included 55 patients (56 hips) who underwent primary THA for hip dysplasia. We evaluated the anterior, posterior, and superior acetabular sector angle (ASA) and medial wall thickness (MWT) at the anatomical hip center (at the 20-mm vertical hip level from teardrop) in the study group (anatomical PAO group) and control group (primary OA group). In addition, we investigated the changes in the socket covering when the socket was positioned 10mm above the anatomical hip center (30mm above the teardrop; elevated osteotomy group). All ASA and MWT values were significantly smaller in the anatomical PAO group than in the primary OA group. In particular, the individuals with a Crowe classification of II/III in the anatomical PAO group presented severe acetabular defects. However, the elevated PAO group had a significantly larger ASA compared to the anatomical PAO group, with improved socket coverings. Acetabular defects in the anatomical hip center following THA after PAO were significantly common compared to those after primary THA. Elevation of hip joint centers as much as 10mm is one therapeutic option in the case of severe acetabular defects following THA after PAO.

Relationship between spinal sagittal alignment and acetabular coverage: a patient-matched control study.

The significance of the relationship between the spine and hip joints has been frequently discussed. However, the relationship between acetabular coverage and spinal sagittal alignment has not been fully elucidated as previous studies did not adequately control for factors that might affect the spinopelvic alignment. The aim of this study was to elucidate the impact of acetabular coverage on spinal sagittal alignment by comparing patient groups matched on sex, age, and the presence of hip and anterior impingement pain. We prospectively enrolled 30 women undergoing periacetabular osteotomy (PAO) for developmental dysplasia of the hip (DDH) and 30 women undergoing hip arthroscopic surgery (HAS) for labral tears. The lateral centre edge angle was measured on hip radiographs. In addition, the sagittal vertical axis, pelvic tilt, pelvic incidence, sacral slope (SS), and lumbar lordosis (LL) were measured on preoperative plain radiographs of the whole spine to assess the sagittal spinal alignment. Clinical and radiologic data were compared between the two groups (PAO vs. HAS). The patient groups did not differ in age and body mass index. The mean SS was significantly greater in the PAO group (41.6° ± 1.6°) than in the HAS group (35.3° ± 1.5°; P = 0.0039). Additionally, the mean LL was significantly greater in the PAO group (54.5° ± 2.0°) than in the HAS group (45.1° ± 1.9°; P = 0.0015). The SS and LL were greater in patients with DDH than in patients with hip pain, but without DDH. Patients with DDH might show lumbar hyperlordosis to rotate the pelvis anteriorly, increasing the anterosuperior acetabular coverage.

The Borderline Dysplastic Hip: Arthroscopy or PAO?

Objectives:The borderline dysplastic hip (characterized by a lateral centre-edge angle (LCEA): 20 - 25° and an acetabular index (AI): 10 - 15°) can pose a significant challenge as symptoms may be due to insufficient acetabular coverage, the presence of femoro-acetabular impingement (FAI) or both. Accordingly, different treatment options have been described, including peri-acetabular osteotomy (PAO), hip arthroscopy, open arthrotomy or a combination of procedures. This study aims to determine patient and deformity-specific characteristics that direct treatment decision-making in the borderline dysplastic hip. Furthermore, we describe the early-term results of both the PAO and hip arthroscopy in treating this challenging patient population.Methods:A prospective, multicenter, longitudinal surgical cohort of young adult hips was searched. From 2060 hips, 291 hips satisfied the inclusion criteria of idiopathic borderline dysplasia, adequate follow-up (> 1-year) and functional outcome. Demographic and radiographic features are included in Table 1. Fifty-five hips (19%) had a previous hip operation (most commonly a hip arthroscopy). A number of different procedure types were performed which were broadly divided into 3 groups; PAO-only (n=42), hip arthroscopy-only (n=127) or PAO and intra-articular treatment (either arthroscopically or open, addressing the cam morphology and/or labral pathology) (n=122). Outcome measures included complications-, re-operations- rates and clinical outcomes using the Harris Hip (HHS) and HOOS scores; pre-operatively and at follow-up; the difference was defined as Δ. Patient characteristics, radiographic morphology and clinical outcome measures were compared between the 3 groups.Results:Patients that underwent a PAO were younger and more likely to be female. The PAO groups had a greater number of previous hip procedures (26%, 24%), most of which were hip arthroscopies. The patients that underwent hip arthroscopy had greater incidence of high alpha angles (66%) compared to the PAO groups (35%, 38%) (p<0.001). The PAO groups having slightly more dysplastic features (LCEA, AI, ACEA) (Table 1). At a mean follow-up of 2.5 years, there were no differences in the complication (7-10%, p=0.8) or re-operation rates (13%). Pre-operatively, the PAO groups had inferior HOOS and WOMAC scores compared to the arthroscopy group (p=0.02-7). No differences in the post-op scores were seen (Table 1). The groups that addressed the intra-articular pathology (arthroscopy and PAO-articular treatment) had significantly greater ΔHHS (23) compared to PAO-only (13) (p=0.02).Conclusion:Younger patients, those with a failed previous arthroscopy, without evidence of intra-articular wear and with worse pre-operative function were more likely to receive a PAO (with or without articular adjunct treatment). Addressing the intra-articular and impingement-related pathology (in addition to a when a PAO is considered necessary) was associated with better improvement in PROMs and should be strongly considered in the borderline hip.Table 1.Patient demographics, radiographic parameters, complication-,re-operation rates and patient reported outcome measures for the whole cohort and the three treatment subgroups.ParameterCohort (n=291)Groupsp-value PAO (n=42) Arthrosropy (n=127) PAO& Intro-articular (n422) Age (years old)27±1122±731±1224±8 <0.001* Gender (%female)77%95%64%84% <0.001* BMI24±424±424±424±40.5Chronicity of pain<1-year32%24%35%31% 0.04* 1-3years45%52%35%52%>3 years13%24%30%17%Previous hip surgery(%)19%26%12%24% 0.02* Previous arthroscopy(%)17%26%9%21%0.1Acetabular Index/°9±311±39±310±3 <0.001* LCEA/°22±222±223±222±2 <0.001* ACEA/°25±823±1028±622±8 <0.001* Cross Over Sign (%)44%31%49%43%0.1CongruityExcellent31%59%%24%28% <0.001* Good65%36%71%69%Fair4%5%5%3%Tõnnis Grade061%76%41%76% <0.001* 138%22%58%24%High α Angle (AP or lateral) (%)50%36%66%38% <0.001* Complication8%10%7%9%0.8Re-operation18%19%16%20%0.8THA by follow-up2%-3%-0.07HHS_pre-op60±1663±1961±1558±160.07HOOS_pre-op54±2252±2158±2250±21 0.02* WOMAC_pre-op64±2264±2267±2261±220.06SF12_pre-op37±1040±1038±1035±10 0.03* HHS_post-op78±1975±2080±1878±190.4HOOS_post-op77±2273±2381±2075±230.07SF12_Ppost-op45±1243±1247±1146±120.6ΔHHS21±2513±1323±2622±200.08ΔHOOS27±3120±3528±3127±290.5ΔSF1210±154±1910±1612±150.02*

Periacetabular osteotomy for developmental hip dysplasia with labral tears: is arthrotomy or arthroscopy required?

ABSTRACTPatients with developmental dysplasia of the hip (DDH) who undergo periacetabular osteotomy (PAO) often have labral tears. The objective of this retrospective study was to compare PAO alone with PAO combined with arthrotomy or arthroscopy in DDH patients who had a full-thickness labral tear on magnetic resonance imaging. In total, 47 hips in the PAO group (PAO) were compared with 60 hips in the PAO with concomitant arthrotomy or arthroscopy (PAO-A) with respect to Hip Disability and Osteoarthritis Outcome Score (HOOS), modified Harris Hip Score (mHHS), Visual Analog Scale (VAS), clinical and radiographic outcomes at a median of 29 months. Reoperation rate and complications were compared between two groups of treatment. The PAO group was younger than the PAO-A group (25.2 ± 9.7 versus 31.3 ± 8.3). The PAO group was more likely to have worse dysplasia: lateral center edge angle (7.6°±9.63° versus 10.8°±6.85°) and anterior center edge angle (4°±12.92° versus 10.8°±9.92°). The PAO group had a higher preoperative mHHS (65.2 ± 15.3 versus 57.8 ± 14.8) and HOOS (66.3 ± 17.5 versus 55.8 ± 20.1). There were no significant differences in final functional outcome scores across treatment groups: mHHS (PAO; 86.8 ± 12.4 versus PAO-A, 83.3 ± 17.2), HOOS (86.5 ± 13.3 versus 82.5 ± 16.8) and VAS (2.5 ± 2.8 versus 2.5 ± 3.1). There was no difference in reoperation rate between two groups (6.4% versus 11.6%, P = 0.51). The overall complication rate was lower in the PAO group (26% versus 68%), but major complications were comparable. On the basis of our data, we were not able to conclusively demonstrate a clear benefit for the routine treatment of all labral tears; however, arthrotomy or arthroscopy may play a role in some conditions.

CORR Insights®: Periacetabular Osteotomy Provides Higher Survivorship Than Rim Trimming for Acetabular Retroversion.

CORR Insights®: Periacetabular Osteotomy Provides Higher Survivorship Than Rim Trimming for Acetabular Retroversion.

Patient Characteristics and Early Functional Outcomes of Combined Arthroscopic Labral Refixation and Periacetabular Osteotomy for Symptomatic Acetabular Dysplasia

Background: Symptomatic labral tears are common in patients with acetabular dysplasia; however, optimal treatment of the labrum remains controversial. Purpose: To present patient characteristics and early functional outcomes associated with combined arthroscopic labral refixation and Bernese periacetabular osteotomy (PAO) for symptomatic acetabular dysplasia with a displaced labral tear from the acetabular rim. Study Design: Cohort study; Level of evidence, 3. Methods: Patients undergoing PAO from a single-center prospective hip preservation registry were eligible (N = 73 patients; mean clinical follow-up, 23 months). Indications for combined arthroscopic labral refixation included symptomatic labral injury and MRI findings suggestive of labral detachment from the acetabular rim indicating a repairable tear. The study group consisted of patients undergoing combined arthroscopic labral refixation and PAO (scope/PAO group: n = 21 patients). Patients undergoing PAO alone (PAO group: n = 52 patients) were included as a comparison. Demographic characteristics, pre- and postoperative radiographic findings, and hip-specific functional outcome scores were recorded. Results: The scope/PAO group was older relative to PAO alone (27 vs 23 years; P = .047). Preoperative computed tomography showed increased acetabular version at the 3-o’clock position in the scope/PAO group relative to PAO alone (median [quartile 1, quartile 3]: 24° [20°, 25°] vs 19° [14°, 24°]; P = .026). PAO operative time, achievement of radiographic correction, or postoperative complications did not differ between groups. Improvements by minimum important change for modified Harris Hip Score, Hip Outcome Score (HOS)–ADL, HOS-Sport, and International Hip Outcome Tool (iHOT-33) were seen in 90%, 79%, 74%, and 100% of patients, respectively, undergoing scope/PAO at most recent follow-up. There was greater improvement from baseline in the iHOT-33 at most recent follow-up in the scope/PAO versus PAO group after adjusting for age and Tönnis grade (mean change ± SD: 48 ± 22 [scope/PAO] vs 37 ± 24 [PAO]; P = .03). Conclusion: Patients undergoing combined arthroscopic labral refixation and PAO were older and had increased acetabular anteversion versus patients undergoing PAO alone. Combined arthroscopic labral refixation and PAO was safe, did not affect PAO operative time or radiographic correction achievement, and may benefit clinical outcomes in this patient subset.

Acetabular Dysplasia in Middle-Aged Patients: Periacetabular Osteotomy or Total Hip Arthroplasty?

BackgroundTreatment of middle-aged patients with acetabular dysplasia is challenging because of mild osteoarthritis, long life span, high activity level, and sports participation. Both periacetabular osteotomy (PAO) and total hip arthroplasty (THA) provide pain relief, improve function, and can last over 2 decades. We compare the 2 procedures for functional outcome (including sports participation), pain relief, and morbidity. MethodsWe compared patients in the 30-50 years age group with symptomatic acetabular dysplasia who underwent PAO (n = 14) or THA (n = 14) with minimum 4-year follow-up. We compared postoperative activity (modified Harris Hip Score, high activity arthroplasty score, and modified Merle d'Aubigné-Postel Score) and sports participation (Tegner and University of California Los Angeles activity scores) in the 2 groups. Morbidity was compared by durations of postoperative pain >4/10, narcotic use, use of gait aids, and time to return to normal activities. ResultsSports participation and function scores improved after surgery in both groups without significant intergroup difference at minimum 4-year follow-up. Patients with PAO had longer duration of postoperative pain (P = .01) and used gait aids longer (P = .04) than patients with THA. There were 3 minor reoperations in the PAO group and none in the THA group. ConclusionsPAO and THA both produce comparable improvement in sports participation and function. PAO was associated with longer durations of pain and use of gait aids. These findings may be important in the decision-making process in middle-aged patients with symptomatic acetabular dysplasia.

Does previous pelvic osteotomy compromise the results of periacetabular osteotomy surgery?

As the Bernese periacetabular osteotomy (PAO) has grown in popularity, specific indications and the results in patients treated for those indications need to be evaluated. Currently, although many patients undergo PAO after having had prior pelvic osteotomy, there is limited information regarding the efficacy of the PAO in these patients. The purpose of this study was to compare the (1) early pain, function, activity, and quality of life outcomes; (2) radiographic correction; and (3) major complications and failures between patients who underwent PAO after prior pelvic reconstruction versus those who had a PAO without prior surgery. Between February 2008 and January 2012, 39 patients underwent PAO after prior pelvic osteotomy at one of 11 centers and were entered into a collaborative multicenter database. Of those, 34 (87%) were available for followup at a mean of 2.5 years (range 1-5 years). This group was compared with a matched group of 78 subjects, of whom 71 (91%) were available for followup at a similar interval. We compared clinical outcomes including UCLA activity score, SF-12, and Hip Disability and Osteoarthritis Outcome Score (HOOS); radiographic measures-anterior and lateral center-edge angle and acetabular inclination (AI)-and reoperations, major complications, and conversions to total hip arthroplasty. Although both groups reached clinical improvement in all categorical measures, the revision PAO group demonstrated greater pain (HOOS pain, study 74 versus 85, p = 0.03; 95% confidence interval [CI], 18.58 to -0.95) and less function (HOOS activities of daily living, study 80 versus 92, p = 0.002; 95% CI, 018.99-4.45) than the primary cohort. The revision cohort achieved a smaller average radiographic correction than in patients undergoing PAO without prior pelvic surgery. The mean correction in AI was less dramatic when directly comparing the revision and comparison groups (-12° to -17°, p < 0.001, SD 2.3-8.5). Although there was no difference in severe complications requiring further surgery, there were two conversions to hip arthroplasty (p = 0.109; 95% CI, 0.004-2.042) in the study group. PAO performed after prior pelvic surgery is associated with improvements in pain, function, radiographic correction, and early complication rates, but the improvements observed at short-term followup were smaller and more variable than those seen in patients who had not undergone prior pelvic surgery. We recommend considering PAO for residual deformities after prior osteotomy to improve function and quality life but warning patients of potential ceiling effects with a second periacetabular surgery.

Mid-term results of Bernese periacetabular osteotomy for developmental dysplasia of hip in middle aged patients

To address the question, compared to having hip replacement with latent revision, does Bernese periacetabular osteotomy (PAO) before primary hip replacement occupy a preferable treatment strategy for middle aged (aged 35-54 years) hip dysplasia patients? We assessed the mid-term functional outcome and survivorship of PAO in those patients. Forty-one hips in 36 patients at middle age at the time of surgery (mean age, 39.5 years; range, 35-47 years) were retrospectively identified out of a total PAO cohort of 315 patients. Eleven of the 41 PAO hips also underwent osteochondroplasty at the femoral head-neck junction. Radiographic parameters of lateral centre edge angle, anterior centre edge angle and hip joint medialisation were investigated using the Harris Hip Score (HHS). The average follow-up was 5.1 years (range, two to ten years). Radiographic parameters postoperatively improved into the normal range, whereas no progression was found from preoperative Tonnis osteoarthritis score. Forty hips survived at the last follow-up, with HHS Score improved from 63.7 to 88.4. Compared to the sole PAO group, both postoperative alpha angle and range of joint motion improved in the PAO combined with osteochondroplasty group. However, no difference in HHS score was found. Good survivorship and improved joint function were identified in middle-aged Chinese patients following PAO with or without osteochondroplasty. We prudently suggest PAO as an alternative strategy for treating DDH in those patients.