Postoperative Alpha Angle Research Articles

Females have Higher Return to Sport Rate than Males Among Collegiate Athletes Following Hip Arthroscopy for Femoroacetabular Impingement Due to the Difference in the Type of Sports, Type of Impingement, Prevalence of Severe Cartilage Damage

To investigate the return to sport (RTS) rate and the sex-based difference of collegiate athletes following arthroscopic treatment for FAI. Patients who were collegiate athletes at the time of surgery and underwent hip arthroscopy for treatment of FAI between January 2009 and June 2020 were included. Patients were excluded if they were in their final year of eligibility, graduated, retired, or had plans to retire from collegiate play prior to surgery. Publicly available data was collected regarding each patient's collegiate team and division, and RTS status after surgery. Comparisons were made based on the RTS status and gender. Of the 181 hips (144 athletes) who met the inclusion criteria, 114 were male (63%) and 67 female (37%) hips with a median age of 20.4 (Range: 18.0-24.5). Eighty-six percent (155 hips) returned to sport at the collegiate level following hip arthroscopy. Males were significantly less likely to return to sport compared to females (82% vs 93%, OR = 2.8, 95% CI [1.003, 7.819], p=0.042). Males participated in more contact sports (26% vs 1.5%, p < 0.001) and had more mixed-type FAI (95.6% vs 80.6%, P=0.003) compared to females. In addition, males had more grade 3/4 chondral defects (28% vs 13%, p=0.023) and underwent microfracture more frequently (11% vs 3%, p=0.047). Further, males had significantly larger postoperative alpha angles (46.2 vs 43.6, p< .001). Collegiate athletes were found to have a high return to sport rate of 86% following arthroscopy for the treatment of FAI, however, males were less likely to return to sport compared to females. Sex-based differences were identified in the type of sports, type of FAI, prevalence of severe cartilage damage, and postoperative alpha angle. Retrospective case series, Level IV.

Paper 17: Does Higher Quality CAM Resection Correlate with Better Patient-Reported Outcomes?

Objectives: The relationships between CAM resection quality and patient-reported outcomes (PROs) are unknown in the literature. This study aimed to investigate the correlation of CAM resection quality with patient’s self-reported International Hip Outcome Tool (iHOT) scores collected annually post-surgery. Methods: A retrospective analysis was conducted including patients who underwent primary hip arthroscopy for femoroacetabular impingement (FAI) between 2012 and 2019. Inclusion criteria were pre-operative radiographic signs of CAM-type impingement (alpha angle &gt; 55 °) and post-operative plain radiographs. Exclusion criteria were radiographic signs of a pincer or mixed impingement, history of femoral neck or proximal femur fracture, and treatment of concomitant hip pathologies. The following data were collected: demographic information, radiographic findings, and iHOT scores. CAM resection quality data were categorized based on findings from three plain radiographs (anteroposterior (AP) pelvis, frog leg lateral, and 45° Dunn views). High quality resections were defined as those post-operative alpha angle &lt;55°. Results: This study included 148 participants who underwent CAM resection. From Frog leg views, 88% of patients had high-quality resections and presented superior post-operative iHOT scores compared to the 12% of patients with poor resection quality during the 1-year to 5-year follow-up period. Likewise, from Dunn views 82% of patients with a high-quality CAM resection displayed a similar trend in post-operative iHOT scores compared to 18% of patients with poor resection quality on Dunn views. However, this positive association between resection quality and post-operative iHOT scores was not evident in AP imaging. With AP views, 82% of patients with high-quality resections did not show a significant difference in iHOT scores compared to 18% of patients with poor resection quality. Conclusions: This study found that high quality CAM resection from arthroscopic surgery correlated with better iHOTs up to 5-years post-surgery from the Dunn and frog leg radiographic imaging views.

Patients With Lateral and Anterolateral Cam Morphology Have Greater Deformities Versus Typical Anterolateral Deformity Alone but No Differences in Postoperative Outcomes: A Propensity-Matched Analysis at Minimum 5-Year Follow-Up

To compare pre- and postoperative findings between patients undergoing hip arthroscopy for femoroacetabular impingement syndrome with lateral impingement versus those without lateral impingement METHODS: Patients who underwent primary hip arthroscopy for femoroacetabular impingement syndrome between 2012 and 2017 with minimum 5-year follow-up were included. Alpha angle (AA) was measured on preoperative anteroposterior (AP) and 90° Dunn radiographs. Patients with AA >60° on Dunn view but not AP view (no lateral impingement) were propensity matched by sex, age, and body mass index in a 1:3 ratio to patients with AA >60° on both views (lateral impingement). Demographic characteristics, radiographic and intraoperative findings, reoperation rates, and patient-reported outcomes (PROs) were compared between groups. Categorical variables were compared using the Fisher exact testing and continuous variable using 2-tailed Student t tests. Sixty patients with lateral impingement (65.0% female, age:35.3 ± 13.0 years) were matched to 180 patients without lateral impingement (65.0% female, age: 34.7 ± 12.5 years, P ≥ .279). Patients with lateral impingement had larger preoperative AAs on both Dunn (71.0° ± 8.8° vs 67.6° ± 6.1°, P=.001) and AP radiographs (79.0° ± 12.1° vs 48.2° ± 6.5°, P < .001). However, there were no differences in postoperative AAs on either view (Dunn: 39.0° ± 6.1° vs 40.5° ± 5.3°, AP: 45.8° ± 9.0° vs 44.9° ± 7.0°, P ≥ .074). Labral tears began more superiorly in patients with lateral impingement (12:00 ± 0:49 vs 12:17 ± 0:41, P= .030), and they demonstrated greater rates of acetabular and femoral cartilage damage (P= .030 for both); however, there were no differences in PROs or reoperation rates between the groups at 5-year follow-up. Although cam deformities located laterally and anterolaterally are larger than those located anterolaterally alone, both can be resected adequately, resulting in similar postoperative radiographic measurements, PROs, and survivorship. Level III, retrospective cohort study.

Weight-bearing CT Scan Analysis in Hallux Valgus Treated with Minimally Invasive Surgery

Category: Bunion; Midfoot/Forefoot Introduction/Purpose: Hallux valgus (HV) is one of the most prevalent foot deformities. Coronal metatarsal rotation (pronation) has been recognized as a key element in HV deformity and an important prognostic factor for recurrence. With the advent of weight-bearing CT (WBCT), accurate pronation measurement has improved. The Minimally Invasive Bosh Akin (MIBA) surgery has proven to be effective in treating HV deformity. The literature analyzing correction of pronation in HV surgery is lacking. Purpose: To compare the transverse and coronal plane deformity correction by WBCT in HV patients treated with MIBA surgery. Methods: We retrospectively analyzed HV deformity in patients who underwent MIBA surgery with preoperative and at least 3 months postoperative WBCT for comparison. Intermetatarsal angle (IMA), hallux valgus angle (HVA), and alpha angle (AA) for first metatarsal pronation were measured by 2 different observers. The intraclass and interclass correlation were determined. Pre and postoperative measurement changes were established by T-test for related samples. the p-value for statistical significance was set at &lt; 0.05. Results: 37 feet were included. Intraclass correlation was 0.97 /0.92 for IMA; 0.95/0.91 for AA and 0.99/0.97 for HVA preoperative. Postop it was 0.97/ 0.96 for IMA, 0.97/0.92 for AA, and 0.98 and 0.96 for HVA. Interclass correlation was 0.95 for IMA; 0.7 for AA and 0.82 for HVA preoperative. Postop, was 0.82 for IMA, 0.8 for AA, and 0.79 for HVA. Mean preoperative / postoperative AA was 8.9 degrees and 6.9 degrees respectively, resulting in a first ray pronation change of –2.0 degrees, p&lt; 0.054. The media preoperative and postoperative IMA was 13.6 degrees and 6.8 degrees, demonstrating a significant change (P &lt; .005). The media preoperative and postoperative HVA was 28.7 (8.8) and 13.1 (9.0), demonstrating a significant change (P &lt; .005). Conclusion: To the best of our knowledge, this is the first study that evaluates the radiological changes in HV surgery with WBCT. The MIBA osteotomy for HV deformity has significant power to correct the transverse plane deformity. Even though the coronal plane deformity correction wasn’t statistically significant, it showed a strong tendency, which might be demonstrated by utilizing a bigger sample. The only measurement that didn’t have an excellent agreement was the preop AA.

Analysis of gender differences with traditional posterior stabilized versus kinematic designs in total knee arthroplasty

IntroductionTotal knee arthroplasty (TKA) is a good treatment for end-stage knee osteoarthritis (KOA). Approximately 60% of the patients are females, and 40% are males. This study analyzed pre- and postoperative angle differences in the range of motion (ROM), and the occurrence of complications with traditional posterior stabilization versus kinematic TKA in relation to gender.MethodsData from 434 patients with primary cemented total knee arthroplasty from 2018 to 2021 were collected. Alpha and beta angles were determined pre- and postsurgery. The ROM was collected pre- and postoperatively and during follow-up. Additionally, perioperative complications, revision rate, and blood transfusion management were investigated.ResultsThe pre- and postoperative alpha-angle between men and women was significantly different, as was the level of alpha-angle correction between men and women (p = 0.001; p = 0.003). Same-gender differences in pre- to postoperative alpha-angles between traditional and kinematic TKA were shown (women (w): p = 0.001; men (m); p = 0.042). High postoperative alpha angles led to less ROM in traditional TKA for women (p = 0.008). No significant gender differences in ROM, perioperative complications, or revision surgery and transfusion rates were found.ConclusionDespite high gender differences in pre- and postoperative angles, only female patients with traditional arthroplasty and high postoperative alpha angles showed less ROM in the follow-up. This leads to the assumption that gender-related pre- and postoperative angle differences, and the degree of angle correction, do not influence the ROM or perioperative occurrence of complications. Both designs present safe procedures for both genders with a wide spectrum of axis deformities.

Postoperative alpha angle seems to be important for the achievement of clinical significance at a minimum 5-year follow-up after primary hip arthroscopy.

The purpose of the present study was to clarify whether there is an association of postoperative alpha value with functional scores or progression of osteoarthritis at X-rays at the midterm after arthroscopic treatment of femoroacetabular impingement (FAI) syndrome with femoral osteoplasty, labral repair or debridement and rim trimming. A retrospective review of prospectively gathered data from 2013 to 2017 was performed. All patients who underwent first-time unilateral hip arthroscopy for FAI resection with 5-year follow-up were included. Patient-reported outcomes included the modified Harris Hip Score (mHHS) and Visual Analog Scale for Pain (Pain VAS). The progression of osteoarthritis (Tönnis grade) and radiological parameters (alpha angle, lateral center-edge angle [LCEA] and head-neck offset) were evaluated. A receiver operating characteristic (ROC) analysis was used to evaluate the correlation between significant variables and achievement of patient-acceptable symptomatic state (PASS) and degree of osteoarthritis. We identified 52 patients with a minimum 5-year follow-up (average, 6.7 years). The average patient age was 33.9 ± 11.5 years. There were 19 (36.5%) female patients. The mHHS improved from 60.1 ± 13.4 before surgery to 86.8 ± 14 after surgery (P < 0.001). The Pain VAS decreased from 6.21 before surgery to 2 after surgery (P < 0.001). Overall, 69% achieved the PASS for mHHS. The ROC curve for postoperative alpha angle demonstrated acceptable discrimination between patients achieving a fifth-year PASS value and those who did not have an area under the curve of 0.72. Patients having a postoperative alpha angle of ≤48.3° achieved the fifth-year PASS value at a significantly higher rate than patients having a postoperative alpha angle of >48.3° (P = 0.002). The postoperative alpha angle is a predictor of the achievement of the fifth-year PASS value for the mHHS. A threshold of ≤48.3° had a sensitivity of 0.75 and a specificity of 0.69 to predict positivity. Level of evidence IV.

Do patients with femoroacetabular impingement syndrome who undergo hip arthroscopy display improved alpha angle (magnetic resonance imaging) and radiographic hip morphology?

To compare (a) the change in radiological bony morphology between participants with femoroacetabular impingement (FAI) syndrome who underwent arthroscopic hip surgery compared to physiotherapist-led non-surgical care and (b) the change in radiological bony morphology between participants with FAI syndrome who underwent arthroscopic hip surgery involving cam resection or acetabular rim trimming or combined cam resection and acetabular rim trimming. Maximum alpha angle measurements on magnetic resonance imaging and Hip2 Norm standardized hip measurements on radiographs were recorded at baseline and at 12 months postoperatively. One-way analysis of covariance and independent T tests were conducted between participants who underwent arthroscopic hip surgery and physiotherapist-led non-surgical care. Independent T tests and analysis of variance were conducted between participants who underwent the 3 different arthroscopic hip procedures. Arthroscopic hip surgery resulted in significant improvements to mean alpha angle measurements (decreased from 70.8° to 62.1°) (P value < .001, 95% CI -11.776, -4.772), lateral center edge angle (LCEA) (P value=.030, 95% CI -3.403, -0.180) and extrusion index (P value=0.002, 95% CI 0.882, 3.968) compared to physiotherapist-led management. Mean maximum 1-year postoperative alpha angle was 59.0° (P value=.003, 95% CI 4.845, 18.768) for participants who underwent isolated cam resection. Measurements comparing the 3 different arthroscopic hip procedures only differed in total femoral head coverage (F[2,37]=3.470, P=.042). Arthroscopic hip surgery resulted in statistically significant improvements to LCEA, extrusion index and alpha angle as compared to physiotherapist-led management. Measured outcomes between participants who underwent cam resection and/or acetabular rim trimming only differed in total femoral head coverage.

Ultrasound Demonstrates Potential in Identifying Proximal Femoral Morphology Before and After Cam Resection: A Cadaveric Study

<h3>Purpose</h3> (1) To compare alpha angles measured on fluoroscopy with those measured on ultrasound pre- and postosteoplasty and (2) to determine whether ultrasound can adequately assess cam deformity correction. <h3>Methods</h3> Twelve full-body specimens (20 hips) were analyzed. Images using fluoroscopy and ultrasound were captured of the operative hip with the hip in 6 consistent positions: 3 views in hip extension (neutral [N], 30° internal rotation [IR], and 30° external rotation [ER]) and 3 views in hip flexion of 50° (neutral [F-N], 40° external rotation [F-ER40], and 60° external rotation [F-ER60]). A curved-array ultrasound transducer probe was used with the transducer placed in line with the femoral neck to evaluate the proximal femoral morphology. An open femoral osteoplasty using an anterior approach was performed. Fluoroscopy and ultrasound were again used to capture images with the hip in the same 6 positions. Bland–Altman plots were used to determine whether fluoroscopic and ultrasound alpha angles agreed at each position. Independent <i>t</i>-tests were used to compare the alpha angles between the 2 modalities at each position, and paired <i>t</i>-tests were used to compare preoperative and postoperative alpha angles at each position. <h3>Results</h3> No significant differences between the alpha angle on fluoroscopy and ultrasound at all 6 positions were appreciated preosteoplasty. The mean preoperative alpha angle on ultrasound in each position was as follows: N (55.4° ± 5.9° vs 43.0° ± 2.1°), IR (55.1° ± 5.3° vs 43.9° ± 5.5°), ER (58.6° ± 5.6° vs 42.8° ± 3.0°), F-N (53.9° ± 5.5° vs 41.6° ± 3.3°), F-ER40 (55.5° ± 4.6° vs 41.5° ± 2.7°), and F-ER60 (57.9° ± 6.5° vs 41.2° ± 4.2°). The mean preoperative and postoperative alpha angle on fluoroscopy in each position were as follows: N (56.0 ± 12.8° vs 43.1 ± 2.1°), IR (54.1 ± 13.4° vs 41.9 ± 2.9°), ER (61.2 ± 11.0° vs 44.2 ± 1.9°), F-N (57.9 ± 10.6° vs 44.0 ± 2.3°), F-ER40 (59 ± 8.2° vs 42 ± 2.2°), and F-ER60 (55 ± 7.6° vs 41.1 ± 2.6°). Postosteoplasty, there was no significant difference between the mean alpha angle on fluoroscopy versus ultrasound in any position except F-N (44.0 ± 2.3 vs 41.6 ± 3.3, <i>P</i> = .015). Bland–Altman plots showed a high level of agreement between alpha angle values on fluoroscopy and ultrasound at all positions pre- and postosteoplasty. There was a significant reduction in alpha angle measured on ultrasound and fluoroscopy at each position following osteoplasty. There were no significant differences in the delta of the pre- and postosteoplasty alpha angle measurements between fluoroscopy and ultrasound. <h3>Conclusions</h3> Ultrasound is a useful tool for assessing a cam deformity in patients with femoroacetabular impingement syndrome and for determining adequate resection of a cam deformity intraoperatively. <h3>Clinical Relevance</h3> Due to the inherent limitations and risks of the fluoroscopy, it is worth evaluating other nonionizing imaging modalities. Ultrasound has potential to be an accessible, cost-effective, and safe imaging modality that lacks radiation and is commonly used for intra-articular hip injections and dynamic examination of the hip.

Paper 27: Return to Sport and Testing following Hip Arthroscopy For FAI in High School and Collegiate Athletes

Objectives:Femoroacetabular impingement (FAI) is a known cause of hip pain and dysfunction in young, active patients and can be successfully managed with hip preservation surgery. For athletes with FAI, however, there is inconsistent data regarding the ability to return to competitive sport after surgery and how performance level is impacted. The purpose of this study is to evaluate patient factors contributing to return to sport after hip preservation surgery.Methods:Study Design: Retrospective cohort We retrospectively reviewed patients aged 14 to 44 who underwent hip preservation surgery between December 2018 and May 2021 and who participated in a competitive or recreational sport pre-operatively. All patients underwent formal return-to-sport (RTS) testing between 4 and 6 months after surgery. Patient-reported outcomes (PROs) were obtained at initial RTS testing using the International Knee (Hip) Documentation Committee (IKDC) questionnaire, Hip Outcome Score – Sports Specific Subscale (HOS-SSS), and Hip Return to Sport After Injury (Hip-RSI) scale. Regression analysis was performed to evaluate the relationship between RTS tests, PRO’s, BMI, pre- and post-operative alpha angles, and degree of correction. Degree of correction was the difference between pre- and post-operative alpha angles measured on Dunn view hip x-rays.Results:We identified 40 patients, 47 operative hips (34 females, 85%). Three patients (4 hips) were excluded for incomplete testing data. Mean age was 17.73 ± 2.7 years. All patients underwent hip arthroscopy for FAI including one case of single-stage bilateral hip arthroscopy. The most common primary sports were dance (7), softball (6), and basketball (5). Mean alpha angles were 67.15 ± 10.9° pre-operatively and 41.37 ± 4.5° post-operatively. Average time from surgery to first RTS testing was 26.79 ± 6.5 weeks (median 25.1 weeks). Mean HOS-SSS score at initial testing was 85.98 ± 11. Posteromedial (PM) and posterolateral (PL) reach on Y-balance test were significantly associated with HOS-SSS score at initial testing (PM: r=0.54, p<0.001; PL: 0.53, p<0.01). Composite Y-balance score was also significantly associated with HOS-SSS score (r=0.6, p<0.01). All other comparisons between PROs and RTS tests were not significantly associated. Similarly, there were no significant associations between time to initial RTS testing and BMI, pre-operative alpha angle, or degree of correction.Conclusions:Higher Y-balance scores at initial RTS testing are associated with improved PROs and perceived readiness to return to sport. This test can be easily incorporated into an assessment for safe return after FAI surgery; further prospective studies are warranted.

Paper 07: Predictors of Return to Sport in High-Level Athletes Following Hip Arthroscopy for Femoroacetabular Impingement

Objectives:The purpose of this study is to identify clinical and radiographic factors that predict return to sport in high-level athletes and to determine thresholds for significant predictors.Methods:Data were reviewed on all patients who underwent primary hip arthroscopy between November 2008 and August 2018. Patients were included if they played professional, college, or high school sports within 1 year before surgery and had preoperative, 3-month, 1-year, and 2-year postoperative patient reported outcome (PRO) scores for modified Harris Hip Score (mHHS), Hip Outcome Score-Sport Specific-Subscale (HOS-SSS), and Non-Arthritic Hip Score (NAHS). Patients were divided into groups based on whether they returned to sport (RTS). Multivariate logistic regression and receiver operator characteristic (ROC) analysis were used to evaluate the correlation between significant variables and RTS.Results:A total of 136 patients with a mean age of 20.8 ± 7.07 years were included. Competition level, postoperative alpha angle, change in alpha angle, and postoperative PROs were significantly different between groups. The multivariate logistic regression model identified postoperative alpha angle as a statistically significant predictor of return to sport [P < .001, S > 9.97 (OR 0.85, CI 0.79-0.91)]. The ROC curve for postoperative alpha angle demonstrated acceptable discrimination between patients returning to sport and patients not returning to sport with an area under the curve of 0.71 and a threshold value of 46˚. Athletes with a postoperative alpha angle ≤ 46˚ returned to sport at a rate of 71.2%, while those with a postoperative alpha angle > 46˚ returned to sport at a rate of 28.1% [(P < .001, S > 9.97 (OR 6.3, CI 2.6-15.2)]Conclusions:Postoperative alpha angle was identified as a predictor of return to sport in high-level athletes. The odds of returning to sport were 6.3 times greater in athletes with postoperative alpha angles ≤ 46˚ compared to athletes with angles > 46˚.

Three-Dimensional Quantification of Cam Resection Using MRI Bone Models: A Comparison of 2 Techniques.

Background:The current clinical standard for the evaluation of cam deformity in femoroacetabular impingement syndrome is based on radiographic measurements, which limit the ability to quantify the complex 3-dimensional (3D) morphology of the proximal femur.Purpose:To compare magnetic resonance imaging (MRI)–based metrics for the quantification of cam resection as derived using a best-fit sphere alpha angle (BFS-AA) method and using 3D preoperative-postoperative surface model subtraction (PP-SMS).Study Design:Descriptive laboratory study.Methods:Seven cadaveric hemipelvises underwent 1.5-T MRI before and after arthroscopic femoral osteochondroplasty, and 3D bone models of the proximal femur were reconstructed from the MRI scans. The alpha angles were measured radially along clockfaces using a BFS-AA method from the literature and plotted as continuous curves for the pre- and postoperative models. The difference between the areas under the curve for the pre- and postoperative models was then introduced in the current study as the BFS-AA–based metric to quantify the cam resection. The cam resection was also quantified using a 3D PP-SMS method, previously described in the literature using the metrics of surface area (FSA), volume (FV), and height (maximum [FHmax] and mean [FHmean]). Bivariate correlation analyses were performed to compare the metrics quantifying the cam resection as derived from the BFS-AA and PP-SMS methods.Results:The mean ± standard deviation maximum pre- and postoperative alpha angle measurements were 59.73° ± 15.38° and 48.02° ± 13.14°, respectively. The mean for each metric quantifying the cam resection with the PP-SMS method was as follows: FSA, 540.9 ± 150.7 mm2; FV, 1019.2 ± 486.2 mm3; FHmax , 3.6 ± 1.0 mm; and FHmean, 1.8 ± 0.5 mm. Bivariate correlations between the BFS-AA–based and PP-SMS–based metrics were strong: FSA (r = 0.817, P = .012), FV (r = 0.888, P = .004), FHmax (r = 0.786, P = .018), and FHmean (r = 0.679, P = .047).Conclusion:Strong positive correlations were appreciated between the BFS-AA and PP-SMS methods quantifying the cam resection.Clinical Relevance:The utility of the BFS-AA technique is primarily during preoperative planning. The utility of the PP-SMS technique is in the postoperative setting when evaluating the adequacy of resection or in patients with persistent hip pain with suspected residual impingement. In combination, the techniques allow surgeons to develop a planned resection while providing a means to evaluate the depth of resection postoperatively.

Hip Arthroscopy for Femoroacetabular Impingement Syndrome Shows Good Outcomes and Low Revision Rates, With Young Age and Low Postoperative Pain Score Predicting Excellent 5-Year Outcomes

To evaluate the clinical outcomes of hip arthroscopy for femoroacetabular impingement syndrome (FAIS) and their predictors at a minimum 5 years' follow-up. We retrospectively analyzed patients with FAIS after first-time unilateral hip arthroscopy between January 2010 and July 2016. Patient-reported outcomes (PROs) included the validated modified Harries Hip Score (mHHS) and Visual Analog Scale for Pain (Pain VAS). We included patients with Tönnis grade 0 or 1 and reported PROs, and excluded patients with previous hip diseases or bilateral symptoms. Bivariate and multivariate analyses were used for data analysis. We included 159 patients with a mean follow-up of 6.4 years, aged 36.18 ± 8.61 years, 41.5% female, and a mean body mass index of 23.61 ± 3.45. The mean postoperative mHHS was 88.82 ± 11.60, and the mean Pain VAS was 1.93 ± 1.89, significantly better than before surgery (P < .001). Postoperative alpha angle (P= .003) and lateral center edge angle (P < .001) were significantly decreased. Most patients (83.7%) achieved clinically important improvement based on patient-acceptable symptom state and minimal clinically important difference (MCID). The overall revision surgery rate was 2.5%. There were no conversions to total hip arthroplasty. Bivariate analysis indicated that age (P < .001), preoperative mHHS (P= .002), and postoperative Pain VAS (P <.001) correlated with postoperative mHHS at a minimum 5 years' follow-up. Multivariate regression analysis of MCID showed that age (P <.001), preoperative PROs (P < .01 for both), and postoperative Pain VAS (P < .001) were significant outcome predictors. Patients with FAIS after first-time unilateral hip arthroscopy showed significant improvement in PROs at mid-term follow-up, with a low revision surgery rate. Young patients and those with low postoperative Pain VAS showed excellent outcomes at a minimum 5 years' follow-up. Level IV, retrospective case series.

Hallux Valgus Pronation Correction by Scarf Osteotomy: Prospective Case Series with WB-CT Scan

Category:Bunion; Midfoot/ForefootIntroduction/Purpose:Hallux valgus is one of the most prevalent foot deformities. Coronal metatarsal rotation (pronation) has been recognized as a key element in hallux valgus deformity and an important prognostic factor for recurrence. New surgical techniques have been developed in order to specifically address pronation deformity but tend to be technically demanding. With the advent of weight bearing CT (WBCT), accurate pronation measurement has improved. Deformity correction by means of metatarsal osteotomies has been an effective way to correct transverse plane deformity but its capacity for pronation correction is not well established. Purpose: Assess transverse and coronal plane rotation deformity correction by WBCT in hallux valgus patients after scarf osteotomy.Methods:We prospectively analyzed hallux valgus deformity in patients who underwent Scarf osteotomy for symptomatic hallux valgus with preoperative and at least 3 month postoperative WBCT for comparison. Intermetatarsal angle (IMA), hallux valgus angle (HVA) and alpha angle (AA) for first metatarsal rotation (pronation) was measured by 3 different observers. The intraclass correlation was determined. Pre and postoperative measurement change was established by T-test and Wilcoxon for related samples.Results:40 feet in 25 patients were included. The interclass correlation between observers was 0.9 for AA (pronation), 0.92 for IMA and 0.95 for HVA in preoperative evaluation and 0.94 for AA, 0.65 for IMA and 0.82 for HVA in postoperative evaluation. The mean preoperative and postoperative AA of the first metatarsal was 8.9 degrees (range -8.83-24,40, SD 6.8) and 6.3 degrees (range -10.7-28.4, SD 8.3) respectively, resulting in a significant first ray pronation change of -2.5 degrees (P =.006). The media preoperative and postoperative IMA was 13.1 degrees (SD 2.9) and 4.9 degrees (SD 2.0) respectively, demonstrating a significant change (P <.001). The media preoperative and postoperative HVA was 25 degrees (SD 6.7) and 5.9 degrees (SD 4.2) respectively, demonstrating a significant change (P <.001)Conclusion:The Scarf osteotomy for hallux valgus deformity has a significant power to correct both transverse and coronal plane (pronation) deformity.

High prevalence of hip lesions secondary to arthroscopic over- or undercorrection of femoroacetabular impingement in patients with postoperative pain

ObjectivesTo compare the prevalence of pre- and postoperative osseous deformities and intra-articular lesions in patients with persistent pain following arthroscopic femoroacetabular impingement (FAI) correction and to identify imaging findings associated with progressive cartilage damage.MethodsRetrospective study evaluating patients with hip pain following arthroscopic FAI correction between 2010 and 2018. Pre- and postoperative imaging studies were analyzed independently by two blinded readers for osseous deformities (cam-deformity, hip dysplasia, acetabular overcoverage, femoral torsion) and intra-articular lesions (chondro-labral damage, capsular lesions). Prevalence of osseous deformities and intra-articular lesions was compared with paired t-tests/McNemar tests for continuous/dichotomous data. Association between imaging findings and progressive cartilage damage was assessed with logistic regression.ResultsForty-six patients (mean age 29 ± 10 years; 30 female) were included. Postoperatively, 74% (34/46) of patients had any osseous deformity including 48% (22/46) acetabular and femoral deformities. Ninety-six percent (44/46) had an intra-articular lesion ranging from 20% (9/46) for femoral to 65% (30/46) for acetabular cartilage lesions. Prevalence of hip dysplasia increased (2 to 20%, p = 0.01) from pre- to postoperatively while prevalence of cam-deformity decreased (83 to 28%, p < 0.001).Progressive cartilage damage was detected in 37% (17/46) of patients and was associated with extensive preoperative cartilage damage > 2 h, i.e., > 60° (OR 7.72; p = 0.02) and an incremental increase in postoperative alpha angles (OR 1.18; p = 0.04).ConclusionPrevalence of osseous deformities secondary to over- or undercorrrection was high. Extensive preoperative cartilage damage and higher postoperative alpha angles increase the risk for progressive degeneration.Key Points• The majority of patients presented with osseous deformities of the acetabulum or femur (74%) and with intra-articular lesions (96%) on postoperative imaging.• Prevalence of hip dysplasia increased (2 to 20%, p = 0.01) from pre- to postoperatively while prevalence of a cam deformity decreased (83 to 28%, p < 0.001).• Progressive cartilage damage was present in 37% of patients and was associated with extensive preoperative cartilage damage > 2 h (OR 7.72; p = 0.02) and with an incremental increase in postoperative alpha angles (OR 1.18; p = 0.04).

Three-Dimensional Measures of Bony Resection During Femoral Osteochondroplasty Are Related to Alpha Angle Measures: A Cadaveric Study

PurposeTo determine whether 3-dimensional (3D)–reconstructed proximal femoral bone models can be used to quantify femoral osteochondroplasty and to determine whether the 3D-based metrics are related to clinical alpha angle measures.MethodsSix cadaveric specimens with cam-type morphology underwent open femoral osteochondroplasty. Alpha angles were measured on the oblique axial computed tomography slice before and after femoral osteochondroplasty. Preoperative and postoperative computed tomography–based 3D reconstructed femur models were generated for each cadaveric specimen. A 3D-3D registration technique was used to merge the preoperative and postoperative models to measure the surface-to-surface distance between the model surfaces. Bivariate correlation analyses were used to determine the correlations between the preoperative, and the difference between the preoperative and postoperative alpha angle (Δ alpha angle) measures and each of the femoral osteochondroplasty variables of surface area (mm2), volume (mm3), maximum height (mm), and mean height (mm). The strength of the bivariate correlations was defined as follows: weak 0.1 to 0.3, moderate 0.3 to 0.5, and strong as 0.5 to 1.00.ResultsBivariate correlations revealed a strong positive correlation between preoperative alpha angle with femoral osteochondroplasty volume (r = 0.899, P = .007) and surface area (r = 0.899, P = .007). No significant correlations were found between the change in alpha angle and the osteochondroplasty variables.ConclusionsIn this study, pre- and postoperative 3D bone models could be used to quantify femoral osteochondroplasty and to determine if the 3D-based metrics are related to clinical alpha angle measures.Clinical Relevance3D-reconstructed image bone models may be helpful to ensure that adequate femoroplasty is performed intraoperatively, in particular with arthroscopic approach in which visualization may be challenging due to capsular management issues and surgeon experience.

Postoperative Alpha Angle Is Predictive of Return to Sport in Athletes Undergoing Hip Arthroscopy for Femoroacetabular Impingement

To identify clinical and radiographic factors that predict return to sport in athletes undergoing hip arthroscopy and to determine thresholds for significant predictors. Data were reviewed on all patients who underwent primary hip arthroscopy between November 2008 and August 2018. Patients were included if they played professional, college, or high school sports within 1 year before surgery and had preoperative, 3-month, 1-year, and 2-year postoperative patient-reported outcome scores for modified Harris Hip Score, Hip Outcome Score-Sport Specific-Subscale, and Nonarthritic Hip Score. Rates of achieving the minimal clinically important difference also were evaluated. Patients were divided into groups based on whether they returned to sport at the same or greater level. Multivariate logistic regression and receiver operator characteristic analysis were used to evaluate the correlation between significant variables and return to sport. A total of 136 patients with a mean age of 20.8 ± 7.07 years were included. Among athletes who attempted to return, professional and collegiate athletes returned to sport at any level at a rate of 85.0% (51/60), and high-school athletes returned at a rate of 88.1% (52/59). Competition level, postoperative alpha angle, change in alpha angle, and postoperative patient-reported outcomes were significantly different between groups. Athletes who returned to sport achieved the minimal clinically important difference for Hip Outcome Score-Sport Specific-Subscale at significantly higher rates than athletes who did not return to sport (91.6% vs 71.7%, P= .002, S= 8.97). The multivariate logistic regression model identified postoperative alpha angle as a statistically significant predictor of return to sport (P < .001, S > 9.97 [odds ratio 0.85, 95% confidence interval 0.79-0.91]). The receiver operator characteristic curve for postoperative alpha angle demonstrated acceptable discrimination between patients returning to sport and patients not returning to sport with an area under the curve of 0.71 and a threshold value of 46°. Athletes with a postoperative alpha angle ≤46° returned to sport at significantly higher rates than those with a postoperative alpha angle >46° [(P < .001, S > 9.97 [odds ratio 6.3, 95% confidence interval 2.6-15.2]). Postoperative alpha angle was identified as a predictor of return to sport in athletes. The odds of returning to sport were 6.3 times greater in athletes with postoperative alpha angles ≤46° compared with athletes with angles >46°. III, retrospective cohort study.

The Severity of Acetabular Retroversion Does Not Influence Outcomes of Arthroscopic Management of FAI

Objectives:Controversy exists regarding optimal treatment of FAI in the setting of acetabular retroversion. The purpose of this study was to investigate changes in pain and function among patients with acetabular retroversion treated with hip arthroscopy. Secondarily, to assess if the severity of posterior wall deficiency influences post-operative outcomes following hip arthroscopy.Methods:A retrospective review of patients with acetabular retroversion with hip arthroscopic surgery at a single institution was performed. Acetabular retroversion was defined by three radiographic criteria: the presence of crossover sign, ischial spine sign, and posterior wall sign. Anteroposterior radiographs were used to measure lateral center edge angle (LCEA), Tonnis grade, anterior wall index (AWI) and posterior wall index (PWI), and alpha angle. Patient-reported outcome (PROs) included modified Harris Hip Score (MHHS), visual analog scale (VAS) and quality of life with Veterans RAND-12 (VR-12). Spearman correlation coefficients were used to determine correlation of PWI with pre- and post-PROs. Multivariate analysis was performed and generalized estimating equation was used to determine independent predictors for outcome scores. Significance was set at p<0.05.Results:Between 2013 and 2019, 138 patients with FAI and acetabular retroversion underwent hip arthroscopy, 67% were female. The average follow-up was 29 months, with minimum of 6 months. Average preoperative LCEA 28, alpha angle 70.1, postoperative alpha angle 44.6 (p<0.05). All PROs demonstrated significant improvement from preoperative baseline to follow-up scores (MHHS (59.5 +/- 14.7 vs 80.8 +/- 18.8), VAS (6.3 +/- 1.7 vs 3.0 +/- 2.7), p<0.0001). Four patients (3%) underwent revision procedures. Upon multivariate analysis, no association between PWI and PROs was not found. Preoperative mHHS was the strongest predictor of clinical outcome.Conclusions:This is the largest study of patients with acetabular retroversion assessing for a correlation between PWI on patient-reported outcomes following arthroscopic management of FAI. In patients with acetabular retroversion, outcomes are good following arthroscopic management with low complication and revision rate following hip arthroscopy. Posterior wall deficiency was not a predictor of poor outcome in patients with acetabular retroversion. In this single surgeon selected series, the severity of retroversion (measured by PWI) does not appear to have a threshold or any correlation with postoperative outcomes in following FAI treatment.

There is no definite consensus on the adequate radiographic correction in arthroscopic osteochondroplasty for femoroacetabular impingement: a systematic review and meta-analysis.

The purpose of this study is to evaluate and define what is considered an adequate radiographic correction in arthroscopic osteochondroplasty for FAI and to secondarily assess how radiographic outcomes relate to patient reported outcomes and complications. The databases EMBASE, PubMed, and MEDLINE were searched for relevant literature from database inception until January 2021. Studies were screened by two reviewers independently and in duplicate for studies reporting on post-operative radiographic outcomes in arthroscopic osteochondroplasty for FAI. Data on radiographic outcomes as well as data reporting functional outcomes and complications were recorded. A meta-analysis was used to combine the mean pre- and post-operative radiographic outcomes using a random effects model. A risk of bias assessment was performed for all included studies using the MINORS score. The most commonly reported radiographic outcome was the alpha angle with a pooled mean post-operative angle of 44° (95% CI 41°-46°), and mean pre- to post-surgical difference of -19° (-22 to -16, I2 = 96%), followed by the LCEA with a pooled mean post-operative angle of 30° (95% CI 29-31) and mean difference after surgery of -4° (-6 to -1, I2 = 97%,). Eleven studies reported on the correlation between radiographic and clinical outcomes with no consistent consensus correlation found amongst the included studies. Similarly, six studies correlated radiographic outcomes with conversion to THA with no consistent consensus correlation found amongst the included studies. Based on this review, the main conclusion is that there is no consensus definition on the optimal radiographic correction for FAI and there was no consistent correlation between radiographic correction and functional outcomes. However, based on the uniform improvement in functional outcomes, this review suggests a post-operative alpha angle target of 44° with a correction target of 19° and LCEA target of 30° with a correction target of 3°. IV.

Surgical Treatment of Femoroacetabular Impingement: Minimum 10-Year Outcome and Risk Factors for Failure.

Background:Femoroacetabular impingement (FAI) is a well-known cause of hip pain and dysfunction in young adults. Surgical treatment has been widely popularized during the past decade. However, most reported results have been limited to short-term and intermediate-term follow-up. The long-term success rate and risk factors for failure are largely unknown. This study aimed to report the long-term (minimum, 10 years) clinical outcomes of surgical treatment of FAI and to describe the clinical and radiographic parameters associated with the failure of treatment involving femoroacetabular osteoplasty (FAO) and labral repair.Methods:Using our prospective hip preservation database, 164 patients (178 hips) who had undergone FAO between January 2005 and April 2009 were identified. Patient demographic characteristics, clinical history, duration of preoperative symptoms, radiographic parameters (preoperative and postoperative alpha angles, hip dysplasia and retroversion, Tönnis grade for osteoarthritis), and intraoperative findings were reviewed and compared between the success and failure groups. At a minimum 10-year follow-up, clinical functional outcomes (modified Harris hip score [mHHS] and Short Form-36 [SF-36] at 6 weeks, 6 months, 1 year, and 10 years) and failure rates (conversion to total hip arthroplasty [THA]) were collected.Results:The mean patient age (and standard deviation) was 34.3 ± 8.4 years, and 65 patients (40%) were female. After the surgical procedure, there was significant improvement in the mean mHHS (59.3 ± 7.3 points preoperatively to 88.4 ± 7.3 points postoperatively) and the mean SF-36 (61.3 ± 8.4 points preoperatively to 89.1 ± 7.2 points postoperatively). At a mean follow-up of 12.5 years, 12% (22 hips) required conversion to THA, with a mean time to THA of 5.3 ± 2.0 years. Older age, longer preoperative symptomatic period, higher preoperative and postoperative alpha angles, presence of hip dysplasia, a higher Tönnis grade, joint space narrowing, and a full-thickness acetabular chondral lesion at the time of the FAO were identified as risk factors for failure and conversion to THA.Conclusions:Patients with symptomatic FAI who undergo a surgical procedure experience pain relief and functional improvement that appear to endure over a decade in the majority of patients. This study on a relatively large cohort with a long-term follow-up has also identified patients who are at a higher risk for treatment failure.Level of Evidence:Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Radiographic Factors Associated With Failure of Revision Hip Arthroscopy

PurposeTo identify clinical and radiographic factors associated with failure of revision hip arthroscopy (RHA).MethodsA database was used to identify patients who underwent primary hip arthroscopy and revision hip arthroscopy (RHA) from January 2007 to December 2017 for the indication of femoroacetabular impingement and failure of the index procedure, respectively. The primary outcome was defined as the change, or difference, in the preoperative to postoperative alpha angle between patients with successful RHA and those with failed RHA. Failure was defined as reoperation on the operative hip for any indication or a modified Harris Hip Score (mHHS) of less than 70 at the 1-year postoperative time point. All patients had a minimum of 2 years’ follow-up from the date of revision hip surgery. Patients with a history of revision were divided into those with failed revisions and those with successful revisions. The inclusion criteria for failed revision included a history of subsequent revision surgery (or arthroplasty) or an mHHS of less than 70 at final follow-up.ResultsThe study included 26 patients, comprising 8 (31%) with failed RHA and 18 (69%) with successful revision. The failure group showed a significantly smaller decrease in the alpha angle with surgery, measured on the Dunn view, compared with the success group. When the preoperative alpha angle was held constant, each 1° increase in the difference between the preoperative and postoperative alpha angles achieved during surgery was associated with a 17% decrease in the odds of failure. Patients included in the success group had both a higher preoperative mHHS (44.2 ± 8.6 vs 34.7 ± 9.6) and a higher postoperative mHHS (83.2 ± 8.3 vs 62.3 ± 14.2) than patients with failed RHA. There was a statistically significant difference in the frequency of patients who achieved the patient acceptable symptomatic state of +74.0 between the failure (25%) and success (83%) groups; 88% of patients in the failure group met the minimal clinically important difference, whereas 100% of patients in the success group (n = 18) met it.ConclusionsComplete resection of cam lesions as determined by changes in the alpha angle, anterior offset, and head-neck ratio when measured on the Dunn 45° view correlates with positive clinical outcomes after RHA.Level of EvidenceIII, Retrospective Comparative Study.