Periacetabular Osteotomy For Symptomatic Acetabular Dysplasia Research Articles

Incidence and risk factors for non-union of the superior ramus osteotomy when hip dysplasia is treated with periacetabular osteotomy.

Periacetabular osteotomy (PAO) is a well-established surgical treatment for hip dysplasia. Few studies report risk factors for the development of superior ramus osteotomy non-union. The purpose of this investigation was to document the incidence and risk factors for this complication. We identified 316 consecutive hips that underwent PAO for symptomatic acetabular dysplasia with a minimum 1-year radiographic follow-up. We developed and validated a technique to measure the superior ramus osteotomy location on anterior-posterior (AP) pelvis radiographs and computed tomography. Logistic regression with generalized estimating equations was used to evaluate the relationships between odds of non-union and potential demographic and radiographic predictor variables in univariate and multivariate analyses. Twenty-nine (9.2%) hips developed superior ramus non-union. Age {median [interquartile range (IQR)] 23 years (18-35) healed versus 35 years (26-40) non-united, P = 0.001}, pre-operative lateral center-edge angle (LCEA) [16° (11-20) healed versus 10° (6-13) non-united, P < 0.001] and the distance from the superior ramus osteotomy to the ilioishial line [15.8 mm (13.2-18.7) healed versus 18.1 mm (16.2-20.5) non-united, P < 0.001] varied significantly between groups. Using multivariate analysis, moderate-to-severe dysplasia [LCEA < 15°, odds ratio (OR) 5.95, standard error (SE) 3.32, 95% confidence interval (CI) 1.99-17.79, P = 0.001], increased age (5-year increase, OR 1.29, SE 3.32, 95% CI 1.105-1.60, P-value = 0.018) and distance from the ilioishial line (3-mm increase, OR 1.67, SE 0.22, 95% CI 1.29-2.18, P < 0.001) were at increased risk of developing non-union. Superior ramus osteotomy non-union is common after PAO. Older age, moderate-to-severe dysplasia, and more medial osteotomy location were independent risk factors for non-union. Consideration should be made in high-risk patients for a more lateral superior ramus osteotomy and adjuvant medical and surgical interventions.

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).

PROMIS Versus Legacy Patient-Reported Outcome Measures in Patients Undergoing Surgical Treatment for Symptomatic Acetabular Dysplasia

Background: No previous study has investigated how the Patient-Reported Outcomes Measurement Information System (PROMIS) performs compared with legacy patient-reported outcome measures in patients with symptomatic acetabular dysplasia treated with periacetabular osteotomy (PAO). Purpose: To (1) measure the strength of correlation between the PROMIS and legacy outcome measures and (2) assess floor and ceiling effects of the PROMIS and legacy outcome measures in patients treated with PAO for symptomatic acetabular dysplasia. Study Design: Cohort study (Diagnosis); Level of evidence, 2. Methods: This study included 220 patients who underwent PAO for the treatment of symptomatic acetabular dysplasia. Outcome measures included the Hip disability and Osteoarthritis Outcome Score (HOOS) pain, HOOS activities of daily living (ADL), modified Harris Hip Score (mHHS), PROMIS pain, and PROMIS physical function subsets, with scores collected preoperatively and/or postoperatively at a minimum 12-month follow-up. The change in mean scores from preoperatively to postoperatively was calculated only in a subgroup of 57 patients with scores at both time points. Distributions of the PROMIS and legacy scores were compared to evaluate floor and ceiling effects, and Pearson correlation coefficients were calculated to evaluate agreement. Results: The mean age at the time of surgery was 27.7 years, and 83.6% were female. The mean follow-up time was 1.5 years. Preoperatively, neither the PROMIS nor the legacy measures showed significant floor or ceiling effects. Postoperatively, all legacy measures showed significant ceiling effects, with 15% of patients with a maximum HOOS pain score of 100, 29% with a HOOS ADL score of 100, and 21% with an mHHS score of 100. The PROMIS and legacy instruments showed good agreement preoperatively and postoperatively. The PROMIS pain had a moderate to strong negative correlation with the HOOS pain (r = −0.66; P < .0001) and mHHS (r = −0.60; P < .0001) preoperatively and the HOOS pain (r = −0.64; P < .0001) and mHHS (r = −0.64; P < .0001) postoperatively. The PROMIS physical function had a moderate positive correlation with the HOOS ADL (r = 0.51; P < .0001) and mHHS (r = 0.49; P < .0001) preoperatively and a stronger correlation postoperatively with the HOOS ADL (r = 0.56; P < .0001) and mHHS (r = 0.56; P < .0001). Conclusion: We found good agreement between PROMIS and legacy scores preoperatively and postoperatively. PROMIS scores were largely normally distributed, demonstrating an expanded ability to capture variability in patients with improved outcomes after treatment.

Activity Level Maintenance at Midterm Follow-up Among Active Patients Undergoing Periacetabular Osteotomy

Background: For active patients undergoing periacetabular osteotomy (PAO), returning to and maintaining a high level of activity postoperatively is a priority. Purpose: To evaluate the maintenance of activity levels at midterm follow-up in active patients treated with PAO for symptomatic acetabular dysplasia. Study Design: Case series; Level of evidence, 4. Methods: Patients who underwent PAO for symptomatic acetabular dysplasia between June 2006 and August 2013 were identified by a retrospective review of our prospective longitudinal institutional Hip Preservation Database. All patients with a preoperative University of California, Los Angeles (UCLA) score of ≥7 and a potential minimum 5 years of follow-up were included in the study. Functional outcome measures were the UCLA score, modified Harris Hip Score (mHHS), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). The maintenance of high activity levels was defined as a UCLA score of ≥7 at final follow-up. Radiographic parameters were measured. Statistical significance was defined as a P value <.05. Results: A total of 66 hips (58 patients) were included. The mean age was 25.3 years (range, 14-47 years), the mean body mass index was 23.9 kg/m2 (range, 19-32 kg/m2), and 72% were female. The mean follow-up was 6.8 years (range, 5-11 years). There were 67% of patients who maintained a UCLA score of ≥7. Patient-reported outcomes improved postoperatively from preoperatively for the mHHS (88 ± 14 vs 67 ± 17, respectively; P < .001) and WOMAC (89 ± 15 vs 73 ± 20, respectively; P < .001). The lateral center-edge angle, anterior center-edge angle, and acetabular inclination were significantly improved at final follow-up (P < .001). Only 4 patients (7%) cited postoperative activity limitations as being caused by hip pain. There were no conversions to total hip arthroplasty. Conclusion: The majority (67%) of active patients returned to preoperative or higher activity levels after PAO at midterm follow-up.

Early Functional Outcomes of Periacetabular Osteotomy After Failed Hip Arthroscopic Surgery for Symptomatic Acetabular Dysplasia

Background: Persistent acetabular dysplasia is a common reason for the failure of hip arthroscopic surgery; however, the effect of prior hip arthroscopic surgery on functional outcomes after subsequent periacetabular osteotomy (PAO) is unknown. Hypothesis/Purpose: The purpose of this study was to (1) compare demographic and radiological findings in patients who had and had not undergone previous hip arthroscopic surgery before PAO for symptomatic acetabular dysplasia and (2) compare the short-term, hip-specific patient-reported outcomes in these same patient populations. It was hypothesized that prior hip arthroscopic surgery is associated with worse early functional outcomes in PAO. Study Design: Cohort study; Level of evidence, 3. Methods: A retrospective cohort study design was utilized. Patients undergoing PAO were enrolled from a single-center, prospective hip preservation registry from March 2011 to April 2015. Patients with a minimum of 1-year clinical follow-up with preoperative and postoperative outcome scores undergoing PAO were eligible for inclusion (n = 93 patients; mean clinical follow-up, 24 months [range, 11-58 months]). The study group consisted of patients undergoing PAO for symptomatic hip dysplasia after prior hip arthroscopic surgery (PREVSCOPE group; 22 patients, 25 hips). Patients undergoing PAO without prior hip arthroscopic surgery (PAOALONE group; 71 patients, 85 hips) were included as a comparison group. Demographic and radiological variables were recorded. Postoperative functional outcome scores (modified Harris Hip Score [mHHS], Hip Outcome Score [HOS], and International Hip Outcome Tool [iHOT-33]) were recorded at 6 months and annually postoperatively. Results: There were no demographic differences between the 2 groups at baseline. Acetabular version, femoral version, Tönnis grade, preoperative lateral center edge angle, and intraoperative procedures were not different between the 2 groups. At 1-year follow-up from the last hip surgical procedure, the mean (±SD) mHHS (73 ± 14 vs 86 ± 14, respectively; P < .001), HOS–Activities of Daily Living (84 ± 12 vs 93 ± 11, respectively; P = .007), HOS-Sport (62 ± 25 vs 85 ± 18, respectively; P < .001), and iHOT-33 (62 ± 21 vs 79 ± 20, respectively; P = .004) were decreased in the PREVSCOPE group versus the PAOALONE group. At last follow-up (mean, 18 months from the last hip surgical procedure), the mHHS and HOS-Sport were lower in the PREVSCOPE group versus the PAOALONE group. There was no difference in complication or reoperation rates between the 2 groups. Conclusion: Failed hip arthroscopic surgery before PAO for symptomatic hip dysplasia is associated with lower hip-specific functional outcomes within the first 1 year of follow-up despite similar baseline demographic and radiological characteristics. These differences persisted in certain outcome scores (mHHS, HOS-Sport) at last follow-up but were less pronounced than at 1 year.

Does Participation in Sports Affect Osteoarthritic Progression After Periacetabular Osteotomy?

Background: Periacetabular osteotomy (PAO) is an effective treatment for symptomatic acetabular dysplasia. However, whether postoperative participation in sports leads to progression of the Kellgren-Lawrence (KL) grade of osteoarthritis (OA) in these patients is unclear. Purpose: To investigate (1) participation in sports before and after PAO and (2) whether postoperative participation in sports leads to progression of the KL grade. Study Design: Case-control study; Level of evidence, 3. Methods: The authors retrospectively reviewed data on 161 patients (183 hips) who underwent PAO for symptomatic acetabular dysplasia with preoperative KL grade 1 or 2 between 1998 and 2011. The mean age at the time of surgery was 42.0 ± 10.9 years (range, 12-64 years), and the mean follow-up duration was 100 months (range, 13-180 months). Data included participation in sports, the University of California, Los Angeles (UCLA) activity scale score, age at the time of surgery, body mass index, follow-up duration, history of treatment for developmental hip dislocations, Merle d’Aubigné-Postel score, Oxford Hip Score, center-edge angle, and KL grade. Univariate and multivariate analyses were applied to determine which factors were associated with progression to KL grade 3 or 4 after PAO. Results: The number of patients who participated in sports significantly increased from 50 (31.1%) preoperatively to 89 (55.3%) postoperatively. The mean UCLA score significantly increased from 4.7 ± 2.1 preoperatively to 5.5 ± 2.0 postoperatively. The KL grade progressed to grade 3 or 4 in 16 hips, including 4 hips that underwent conversion to total hip arthroplasty. No significant differences were found in postoperative participation in sports (89 hips [53.3%] vs 11 hips [68.8%], respectively; P = .24) and the UCLA score (5.6 ± 2.0 vs 5.1 ± 2.0, respectively; P = .30) between hips with KL grade 1 or 2 and KL grade 3 or 4. A multivariate analysis revealed that no factors, including postoperative participation in sports, were significantly associated with progression to KL grade 3 or 4. Conclusion: Postoperative participation in sports after PAO did not significantly and negatively influence progression of the KL grade at midterm follow-up.

Does Tranexamic Acid Reduce Blood Loss and Transfusion Requirements Associated With the Periacetabular Osteotomy?

Tranexamic acid (TXA) has shown safety and efficacy in reducing blood loss associated with various surgical procedures. However, to our knowledge there are no studies evaluating the effect of TXA on blood loss and transfusion requirements associated with periacetabular osteotomy (PAO). The main purpose of this study is to determine whether TXA reduces blood loss and transfusion use in patients undergoing PAO for symptomatic acetabular dysplasia. Our secondary purpose was to compare the frequency of symptomatic thromboembolic events between patients undergoing surgery with and without TXA. A consecutive series of 100 periacetabular osteotomies performed by one surgeon was reviewed to compare the groups immediately before and after implementation of routine use of tranexamic acid (two retrospective cohorts). TXA dosing followed an established protocol with a standard dose of 1 g infused intravenously during 10 minutes before skin incision and an additional 1 g intravenously at wound closure. Outcome measures include total estimated blood loss perioperatively and transfusion requirements. Total estimated blood loss was calculated using a formula built from the National Surgical Quality Improvement Program data regarding surgical blood loss. The mean perioperative total estimated blood loss was less in the patients receiving TXA compared with blood loss in patients who did not receive TXA (706 mL versus 1021 mL; p<0.001; 95% CI, -495 to -134). Twenty-six (52%) of the 50 patients who did not receive TXA had postoperative blood transfusions compared with 15 (30%) of 50 who received TXA (odds ratio, 0.395; 95% CI, 0.174-0.899; p=0.0414). No symptomatic deep vein thromboses or symptomatic pulmonary emboli were identified in either group. TXA reduces estimated blood loss and the frequency of transfusions in patients undergoing PAO for treatment of symptomatic acetabular dysplasia. Future prospective studies should confirm our findings to determine whether patients undergoing PAO should receive routine perioperative TXA. Level III, therapeutic study.

Are there sex-dependent differences in acetabular dysplasia characteristics?

Many patients who undergo periacetabular osteotomy (PAO) for symptomatic acetabular dysplasia experience decreased pain and improved function, yet some experience inadequate clinical improvement. The etiologies of treatment failure have not been completely defined, and sex-dependent disease characteristics that may be associated with less pain relief are not understood. We sought to determine whether there were clinically important sex-specific differences between male and female patients undergoing PAO for acetabular dysplasia in terms of (1) clinical parameters (anthropomorphic traits and hip scores), (2) radiographic findings, and (3) intraoperative findings at the time of PAO, in particular findings potentially associated with femoroacetabular impingement (FAI) such as chondromalacia at the head-neck junction, impingement trough, or reduced head-neck offset. Between 2007 and 2012 we treated 245 patients (270 hips) with a PAO for symptomatic acetabular dysplasia. Of those, 16 patients (16 hips; 6%) had insufficient documentation for review in the medical record and another 49 patients (51 hips; 19%) met prespecified exclusion criteria, leaving 180 patients (203 hips; 75%) for analysis in this retrospective study. One hundred thirty-nine patients were females and 41 were males. Clinical data including patient demographics, physical examination, patient self-reported outcome scores, radiographic morphologic features, and intraoperative findings were collected prospectively as part of an institutional registry. Statistical analysis was performed with univariate and multivariate analyses. Mean age was similar among sexes; however, BMI was greater in males compared with females (26 versus 24 kg/m(2); p = 0.002). Males had less hip ROM including internal rotation at 90° flexion (14° ± 13.8° versus 25° ± 16.2°; p = 0.001). Males had higher preoperative UCLA (7 ± 2, versus 6 ± 2; p = 0.02) and Harris hip scores (63 ± 15 versus 58 ± 16; p = 0.04). Radiographically, a crossover sign (88% versus 39%; p < 0.001) and posterior wall sign (92% versus 63%; p < 0.001) were more common in males. Males had greater alpha angles on the frog lateral (63° ± 15.3° versus 58° ± 16°; p = 0.04) and Dunn radiograph views (64° ± 15.5° versus 56° ± 14.8°; p = 0.02). The incidence of femoral head-neck chondromalacia (62% versus 82%; p = 0.03) and an impingement trough observed at surgery was greater in males (35% versus 17%; p = 0.01). Multivariate analysis showed differences between the sexes for reduced internal rotation in flexion, a higher Dunn alpha angle, increased incidence of a crossover sign, and a lower anterior center-edge angle. There are sex-dependent, disease characteristic differences in patients with symptomatic acetabular dysplasia. Most notably, male patients have a greater prevalence of clinical, radiographic, and intraarticular findings consistent with concurrent FAI and instability and potentially a heightened risk of secondary FAI after PAO, however postoperative and long-term followup are needed to confirm these findings and it remains unclear which patients need surgical correction of the impingement and instability. Preoperative evaluation of acetabular dysplasia in males should at least include careful attention to factors associated with symptomatic FAI; however, further studies are needed to determine when surgical correction is needed.

Acetabular blood flow during Bernese periacetabular osteotomy: an intraoperative study using laser Doppler flowmetry

Background: The blood flow to the acetabular fragment is of some concern in juxtaarticular pelvic osteotomies used for the treatment of hip dysplasia. No direct measurements have determined the effect of the Bernese periacetabular osteotomy (PAO) on acetabular perfusion. Methods: Acetabular perfusion was measured by means of laser Doppler flowmetry in 10 patients undergoing a PAO for symptomatic acetabular dysplasia. During the surgical procedure, the intraosseous high energy laser Doppler reliably depicts dynamic changes of small vessel blood flow. Measurements were performed after defined surgical steps to obtain sequential information on the blood perfusion of the acetabular fragment. Results: After complete separation of the acetabular fragment, nine out of 10 patients had pulsatile signals, but the blood flow (BF) significantly decreased by 77%. Corrective positioning of the fragment induced no further drop of the BF signal but a loss of pulsatility in six patients. After a recovery period of about 30 min following preliminary fixation of the fragment, reestablishment of the pulsatile signal and an increase of the BF signal was seen. At termination of the surgical procedure, five out of eight patients, who could be followed throughout the whole procedure, showed a clear pulsatile signal in the supraacetabular area. Bleeding of the supraacetabular cancellous surface could be observed in all acetabula. Conclusion: Despite careful preservation of soft tissues during the surgical procedure, a significant reduction of the blood flow in the supraacetabular region has been observed. Nevertheless, a pulsatile signal in more than 60% of the fragments after fragment correction and an increasing signal during the recovery period showed ongoing blood perfusion indicating reversible changes in the measured supraacetabular area. All osteotomies healed within eight weeks without showing signs of necrosis during a minimum follow up of 1 year.