Symptomatic Femoroacetabular Impingement Syndrome Research Articles

PATIENTS WITH FEMOROACETABULAR IMPINGEMENT SYNDROME OBTAIN SIGNIFICANT AND SUSTAINED IMPROVEMENT FOLLOWING A COMBINED HIP INJECTION AND REHABILITATION PROGRAM

INTRODUCTION Initial treatment recommendations for symptomatic femoroacetabular impingement syndrome include non-surgical therapies such as injections and rehabilitation. However, many patients undergo isolated injections or a rudimentary exercise regime. This study investigated the benefit of a combined intra-articular hip injection and structured exercise rehabilitation program in patients with FAIS. METHODS Participants were recruited and underwent a guided intra-articular injection of corticosteroid and local anaesthetic, followed by a 12-week rehabilitation program. Patients were assessed pre-and post-injection(8 weeks, 4, 6, 12 and 24 months) via patient-reported outcome measures including the 33-item International Hip Outcome Tool and Hip Outcome score. Hip ROM and peak isometric hip strength in all planes were assessed, along with single-limb hop capacity. Limb Symmetry Indices were calculated. The percentage of patients transitioning toward surgery over the period was evaluated. RESULTS A total of 44 patients underwent the injection and completed the initial 8-week rehabilitation component. A significant improvement (p<0.05) in all PROMs was observed, with 93% of patients satisfied. A significant increase (p<0.05) in all active hip ROM and isometric strength measures was observed, sustained over the 24-month period. Bilateral improvements in hop capacity were observed, with all hop test LSIs significantly improving (p<0.05). Overall, 14 patients (32%) progressed toward surgical intervention over the 24-month post-injection period. These patients reported significantly worse (p<0.05) PROMs pre-surgery and more pain within the first 4 weeks post-injection. CONCLUSION This is the first study seeking to implement and comprehensively assess a best-practice, multimodal non-operative program consisting of an intra-articular injection and a structured exercise program. Most patients with symptomatic FAIS demonstrated significant improvement in symptoms.

Orthobiologics as an adjunct in treatment of femoroacetabular impingement syndrome: cell-based therapies facilitate improved postoperative outcomes in the setting of acetabular chondral lesions-a systematic review.

To evaluate studies utilizing orthobiologics in the management of femoroacetabular impingement syndrome (FAIS) to (1) assess the indications for usage, and (2) analyze patient-reported outcome measures (PROM) following treatment. It was hypothesized that orthobiologics would (1) be utilized for symptomatic FAIS in the setting of labral or chondral pathology, and (2) improve PROM at most recent follow-up. The Pubmed, Ovid Medline, Cochrane, and Web of Science databases were searched for clinical studies evaluating orthobiologics [hyaluronic acid (HA), platelet-rich plasma (PRP), or cell-based therapy (CBT) for treatment of FAIS. Exclusion criteria included orthobiologics used in conjunction with cartilage transfer or scaffolding procedures and a primary indication other than FAIS. Data collection included patient demographics, indications, and baseline and most recent PROM. Eleven studies (one level I, four level II, four level III, and two level IV evidence) met inclusion criteria, consisting of 440 patients with mean ages ranging from 32.8 to 47years. All 11 studies demonstrated an improvement in PROM from baseline to most-recent follow-up. Four studies administered PRP either intraoperatively or the day after surgery as an adjunct to labral repair. CBT was used intraoperatively in the setting of acetabular chondral lesions (three studies) and labral repair (one study). When comparing to a control group at most recent follow-up, three PRP cohorts demonstrated similar PROM (n.s.), while one PRP group exhibited worse visual analog pain scores (2.5 vs. 3.4, p = 0.005) and modified Harris Hip Scores (mHHS) (82.6 vs. 78.7, p = 0.049). The four CBT studies reported favorable results compared to a control group, with a significantly higher mHHS at most recent follow-up or mean improvement from baseline in Hip Outcome Score-Activities of Daily Living (p < 0.05). Three studies reported on HA, which was utilized exclusively in the nonoperative setting. Intraoperative PRP and CBT have been commonly reported in the setting of hip arthroscopy for labral repairs and acetabular chondral lesions, respectively. The CBT cohorts demonstrated more favorable PROM at most recent follow-up when compared to a control group, though these results should be interpreted with caution due to heterogeneity of orthobiologic preparations. IV.

Poster 231: Three-Dimensional Statistical Shape Modeling of Hip Morphology is More Predictive of Femoroacetabular Impingement Syndrome Compared to Traditional Two-Dimensional Radiographic Metrics

Objectives: Femoroacetabular impingement syndrome (FAIS) is classically described as cam, pincer, or mixed morphology, leading to pathologic osseous contact between the femur and acetabulum (Beck JBJS). Many studies have analyzed femur shape variability and/or acetabulum shape variability in isolation, rather than utilizing meaningful articulation of a loaded joint. At present, there is limited evidence characterizing how morphologic variations of an articulated hip joint contribute to FAIS. The primary objective of this study was to assess morphologic variations of the articulated hip joint amongst patients with FAIS compared to an asymptomatic cohort using statistical shape modeling (SSM). The secondary objective was to determine which two-dimensional (2D) measures have the strongest correlation with three-dimensional (3D) parameters associated with FAIS. Methods: This retrospective case-control study recruited 14 patients with unilateral or bilateral symptomatic FAIS and 24 asymptomatic controls with no known history of hip surgery, chronic hip- related pathology, or severe musculoskeletal injury to the lumbar spine, hip, or lower extremity. Participants underwent computed tomography (CT) scans of their bilateral pelvis and proximal femurs (0.5 x 0.5 x 1.25 mm) that were used to create preoperative subject-specific bone models of the proximal femur and hip joint. Participants also underwent static standing biplane radiographs that were used to characterize articulation of their loaded hip joint. These 3D hip positions were determined with sub-millimeter accuracy using a previously validated volumetric model-based tracking process that matched the subject-specific bone models to the biplane radiographs. Once co-registered, left-sided hip joints were mirrored for each patient, to allow for comparison between left and right hip joints, and uploaded to Shapeworks 6.3 for SSM analysis. Using principal component analysis (PCA), complex morphologic variations within the study population were distilled into more digestible categories known as modes, which represented simplified independent morphologic variations. Scores for each mode for each hip are derived from the PCA and represent the morphology of patient-specific hip joints as compared to the overall study cohort. Multivariate regression was performed to identify subject-specific mode scores and demographics that predicted FAI using Stata 16E software. Lastly, Pearson correlations were utilized to correlate 2D measurements of alpha angle, femoral version, and acetabular version to mode scores. Results: Of the 14 symptomatic cases with known cam-type FAIS, 11 met inclusion/exclusion criteria, yielding 11 cases (22 hip joints). Of the 24 controls recruited, no patients were excluded, resulting in 48 additional hip joints. Therefore, the final cohort consisted of 35 patients, roughly one-third of which showed FAIS pathology and eventually underwent femoroplasty, and two-thirds had no history of pathology prior to recruitment. Table 1 details mode descriptions from a surgeon with specialized fellowship training in hip preservation and the amount of explained morphologic variation captured by each mode. Figure 1 illustrates a montage of images that represent variations across Mode 1. Only Mode 1 (p = 0.0006), Mode 6 (p = 0.031), and patient age (p = 0.002) were able to distinguish between cases and controls. However, when further specifying the laterality of surgical intervention for FAIS correction, an interaction was observed between Mode 1 and patient age. More specifically, hip joints with lower Mode 1 values were more likely to require surgery at a younger age; whereas higher Mode 1 values demonstrated no association between age and probability of undergoing surgical intervention ( Figure 2). Mode 6 was not predictive of surgical intervention. When considering 2D measurements, femoral version was the only parameter associated with Mode 1 values (r = -.41, p = 0.004), while alpha angle was the only predictor of Mode 6 values (r = -.41, p = 0.001). Acetabular version was not associated with either. Conclusions: Diagnostic criteria for FAIS are heterogeneous and imprecise. Femoral neck rotation within the acetabulum in combination with anteroposterior placement of the greater trochanter relative to the femoral neck axis is the strongest predictor of symptomatic FAIS. These results highlight the limitations of using 2D static imaging to represent highly complex 3D articulating structures, especially femoral variations. Although less precise than 3D methods, 2D measurements of femoral version, rather than alpha angle, may serve as a more accurate risk assessment for FAIS. SSM more accurately predicts symptomatic FAIS requiring surgery compared to traditional 2D radiographic metrics. This technique may help to identify patients who may benefit from early intervention and facilitate joint preservation. Furthermore, SSM may help identify patients who have a morphology that may be better treated with open rotational osteotomy rather than hip arthroscopy surgery. [Table: see text]

Comparison of the PROMIS and iHOT-12 in Determining Satisfaction Levels After Hip Arthroscopy for FAIS.

The Patient-Reported Outcomes Measurement Information System (PROMIS) has not been fully evaluated for outcomes assessment after hip arthroscopy to correct femoroacetabular impingement syndrome (FAIS). The purpose of this study was to compare the accuracy of the PROMIS Physical Function (PF) and Pain Interference (PI) subscales with the 12-Item International Hip Outcome Tool (iHOT-12) to define patients with 3 unique substantial clinical benefit (SCB) scores-patients who reported ≥80%, ≥90%, and 100% satisfaction at 1 year after hip arthroscopy for FAIS. We hypothesized that the iHOT-12 would be more accurate than the PROMIS-PF and PROMIS-PI subscales in identifying these 3 patient groups. Cohort study (diagnosis); Level of evidence, 2. We reviewed the records of patients who underwent hip arthroscopy for symptomatic FAIS at 3 centers from January 2019 through June 2021 and had 1-year clinical and radiographic follow-up data. Patients completed the iHOT-12, PROMIS-PF, and PROMIS-PI on initial assessment and at 1 year (±30 days) postoperatively. Postoperative satisfaction was reported on an 11-category scale with anchors defined as "0% satisfied" and "100% satisfied." Receiver operator characteristic analysis was performed to determine the absolute SCB values for the iHOT-12 and PROMIS subscales that would most accurately identify those patients who reported ≥80%, ≥90%, and 100% satisfaction. Area under the curve (AUC) values and 95% CIs for the 3 instruments were compared. Included were 163 patients (111 [68%] women and 52 [32%] men), with a mean age of 26.1 years. Corresponding absolute SCB scores for patients who reported ≥80%, ≥90%, and 100% satisfaction were as follows: iHOT-12, 68.4, 72.1, 74.7; PROMIS-PF, 45, 47.7, 49.9; and PROMIS-PI, 55.9, 52.4, 51.9. The AUC ranged between 0.67 and 0.82, with overlapping 95% CIs indicating a minimal difference in accuracy between the 3 instruments. Sensitivity and specificity values ranged between 0.61 and 0.82. The PROMIS-PF and PROMIS-PI subscales were as accurate as the iHOT-12 in defining absolute SCB scores for patients reporting ≥80%, ≥90%, and 100% satisfaction at 1-year follow-up after hip arthroscopy for FAIS.

The Effect of a Formal Nonoperative Management Program Combining a Hip Injection With Structured Adjunctive Exercise Rehabilitation in Patients With Symptomatic Femoroacetabular Impingement Syndrome

Background: Although the initial treatment recommendations for femoroacetabular impingement syndrome (FAIS) may include nonsurgical therapies such as injections and rehabilitation, many patients undergo isolated injections or a rudimentary exercise regimen. Purpose: To investigate the benefit of an intra-articular hip injection and concomitant structured exercise rehabilitation program in patients with symptomatic FAIS ≥6 months. Study Design: Case series; Level of evidence, 4. Methods: For this study we recruited 49 patients with a mean age of 32.8 years (range, 16-56 years) and symptoms ≥6 months (range, 6-250 months) associated with FAIS, as confirmed via magnetic resonance imaging and radiography. After a guided intra-articular injection of corticosteroid and local anesthetic, patients underwent a structured 12-week rehabilitation program. Patients were assessed before and after injection (8 weeks and 4, 6, 12, and 24 months) with a range of patient-reported outcome measures (PROMs), including the 33-item International Hip Outcome Tool, Hip Outcome Score, modified Harris Hip Score, the Tegner Activity Score, a visual analog scale assessing the frequency and severity of hip pain, and a Global Rating of Change scale. Range of motion, peak isometric hip strength, and hop tests were assessed. Absolute scores and limb symmetry indices were calculated. The percentage of patients transitioning toward surgery over the period was evaluated. Results: Of the 44 patients who underwent the injection and completed the initial 8-week rehabilitation component, 14 (31.8%) progressed toward surgical intervention over the 24-month postinjection period owing to dissatisfaction and/or symptom recurrence. Patients who progressed toward surgery, as compared with those who did not, reported significantly worse (P < .05) PROMs presurgery and more pain within the first 4 weeks after injection. In the nonoperative cohort, a significant improvement (P < .05) in all PROMs was observed, with 93% of these patients satisfied overall. The Global Rating of Change did not improve, although this was measured only after the injection, reflecting no further significant perceived global change from 8 weeks to 24 months. A significant increase (P < .05) in all hip range of motion and most isometric strength measures was observed at 8 weeks after injection, with these improvements largely sustained until 24 months. Bilateral improvements in hop capacity were observed, with hop test LSIs significantly improving for the single (p = 0.009), triple (p = 0.029) and triple crossover (p = 0.005) hop tests for distance. Conclusion: Although 32% of patients progressed toward surgery, significant improvement in hip pain, symptoms, and physical function was observed in the majority of patients with symptomatic FAIS as a result of a targeted nonoperative management pathway consisting of an intra-articular injection and a structured exercise program.

Change in functional biomechanics following a targeted exercise intervention in patients with acetabular retroversion and femoroacetabular impingement syndrome

BackgroundAcetabular retroversion is a form of hip dysplasia that may cause femoroacetabular impingement syndrome (FAIS), leading to pain and restricted hip range of motion. An exercise intervention aiming at altering pelvis tilt and related functional biomechanics may be a useful first-line intervention for patients who are not eligible for surgical repositioning. Research questionDoes squat and gait biomechanics change following an 8-week targeted exercise program in individuals with symptomatic acetabular retroversion and FAIS? MethodsThis prospective intervention study used participants as their own controls. Examinations were conducted at three time-points: T1 baseline; T2 following an 8-week control period; T3 after 8 weeks’ intervention. At each time-point, three-dimensional motion analysis of a deep squat and level gait was performed, and pain intensity was recorded using a numerical rating scale (NRS 0–10). The intervention consisted of a home-exercise program to improve core stability and pelvic movement. Differences in waveforms between time-points across pelvis and lower-limb biomechanics were evaluated using statistical parametric mapping. Delta (Δ, differences between T1-T2 and T2-T3) was used to evaluate changes in spatiotemporal gait parameters and pain. ResultsNineteen patients (18 females), mean age 22.6 (SD 4.5) years, BMI (kg/m2) 23.0 (SD 4.1), were included. Changes (Δ T1-T2 vs. Δ T2-T3) in squat biomechanics were observed as: (i) decreased anterior pelvic tilt, (ii) deeper vertical pelvis position, and (iii) increased knee flexion angle. Contrary, no significant changes in gait biomechanics, Δ walking speed, Δ step length, or NRS for pain were found. SignificanceFollowing a targeted exercise intervention, participants were able to squat deeper, potentially allowing better hip function. The deepened squat position was accompanied by increased knee flexion and reduced anterior pelvic tilt. Gait biomechanics and patient-reported pain remained unchanged post-intervention. These findings are important for future design of exercise interventions targeting pelvic tilt in symptomatic individuals.

Improvement in pain and patient-related outcome measures following hip arthroscopy in patients with femoroacetabular impingement syndrome and concomitant generalized ligamentous laxity: a systematic review.

Within orthopaedic sports medicine, concomitant ligamentous laxity is often found to be a negative prognostic factor for post-operative outcomes following various procedures. The effect of ligamentous laxity on outcomes following hip arthroscopy remains infrequently reported. Therefore, the purpose of this study is to report on the outcomes of hip arthroscopy for the treatment of femoroacetabular impingement syndrome (FAIS) with concomitant generalized ligamentous laxity (GLL). A systematic search was performed in Medline, EMBASE, CENTRAL, and SPORTDiscus (from inception to April 2021) for studies reporting outcomes following hip arthroscopy for symptomatic FAIS in patients with concomitant GLL. Six studies representing 213 patients and 231 hips were included. Outcomes of pain and functional scores as measured by VAS, Harris Hip Score, and Hip Disability and Osteoarthritis Outcomes Score were tabulated. A mean improvement of 4.8 on VAS was observed. Improvements of 30.0 on HHS, 33.1 for ssHOS, and 23.9 for ADL-HOS were observed. Hip arthroscopy is an effective method of alleviating pain and improving function with statistically significant improvements in all PROM in patients with concomitant FAIS with GLL. IV. CRD42021248864.

Collection of the International Hip Outcome Tool-12 Using a Smartphone Application Format Is Faster and Preferred When Compared With the Paper Version: A Pilot Study of rHip

PurposeTo evaluate the agreeability between the mobile application-based International Hip Outcome Tool-12 (iHOT-12) survey with the paper version, as well as compare the time it takes patients each of the versions, and patient preferences between the two.MethodsPatients seen with symptomatic femoroacetabular impingement syndrome were prospectively enrolled in February 2019 and completed both the paper and application-based iHOT-12, in randomized order. Outcomes scores and time to completion were recorded for each version, and patients were also asked which they preferred. Intraclass correlation coefficient was calculated to assess for absolute agreement between the 2 versions. Bland–Altman plots were constructed to evaluate the agreeability between paper and application-based iHOT-12 scores. Bland–Altman plots were evaluated to identify systematic bias and data stratification was performed to identify sequence bias between the application and paper-based collection modalities.ResultsTwenty-nine patients (aged15-56 years) completed both the paper and application-based versions of the iHOT-12. Between the application-based and paper versions, the intraclass correlation coefficient was 0.98, and Bland–Altman analysis showed agreement without bias between versions. There was no sequence bias. Accounting for completion order, the application-based iHOT-12 was faster for patients when compared to the paper version (61.4 ± 20.3 vs 71.9 ± 23.6 seconds, P = .02). Twenty-two patients reported a version preference where 19 of 22 (86%) chose application-based (P < .001).ConclusionsThe application-based iHOT-12 demonstrated absolute agreement with the paper iHOT-12, and is faster for patients to complete. Patients preferred using the application-based iHOT-12 over the paper-based version. Application-based PROs allow for collection of patient data at more frequent time points, which may be helpful in tracking the recovery progress of patients and predicting outcomes.Clinical RelevanceAs electronic-based outcome surveys become more common, it is important to know how the results may differ from traditional paper-based surveys.

Patients Require Less Time to Complete Preoperative Patient-Reported Outcomes Measurement Information System (PROMIS) Than Legacy Patient-Reported Outcome Measures

PurposeTo analyze time to completion of preoperative legacy patient-reported outcomes (PROs) and more recent computer adaptive Patient-Reported Outcomes Measurement Information System (PROMIS) questionnaires in patients with symptomatic femoroacetabular impingement syndrome undergoing primary hip arthroscopy.MethodsA retrospective analysis was conducted on patients undergoing hip arthroscopy by a single fellowship-trained hip arthroscopist. Inclusion criteria were patients undergoing primary arthroscopic hip surgery and completion of at least 1 legacy PRO or PROMIS questionnaire at the preoperative time point. Exclusion criteria were history of contralateral or ipsilateral hip surgery, non–English-speaking patients, patients who completed PROs by phone or by paper form, and patients who did not complete preoperative PROs. Legacy PROs included modified Harris Hip Score (mHHS), Hip Outcome Score (HOS), International Hip Outcome Tool (iHOT-12), and Hip Pain Visual Analog Scale (VAS-Pain). PROMIS PROs included Physical Function (PROMIS-PF), Pain Interference (PROMIS-PI), and Depression (PROMIS-D). Only preoperative PROs were included in the analysis. Completion time was calculated using the questionnaire start and stop time reported by the survey collecting software. The median and interquartile range of each PRO were reported for analysis of central tendency and statistical dispersion, respectively.ResultsA total of 1,901 patients and 269 patients were included in the legacy and PROMIS groups, respectively. The median time required for completion of each PRO in (minutes: seconds) format was as follows: mHHS (1:29), HOS (3:58), iHOT (2:11), VAS-Pain (0:32), PROMIS-PF (0:46), PROMIS-PI (0:37), and PROMIS-D (0:43). The interquartile range of the middle 50% of respondents was as follows; mHHS (0:58), HOS (2:46), iHOT (1:22), VAS-Pain (0:28), PROMIS-PI (0:19), PROMIS-D (0:29), and PROMIS-PF (0:20).ConclusionsThis study supports that preoperative PROMIS forms require less time to complete than preoperative legacy PROs and are not significantly influenced by age, race, or workers compensation status.Level of EvidenceLevel IV, case series.

Preoperative and Postoperative Walking Gait in Women With Acetabular Labral Tears and Femoroacetabular Impingement Syndrome.

Symptomatic femoroacetabular impingement syndrome (FAIS) is a painful condition that leads to decreased function. How walking gait changes over time within the first year after surgery for FAIS and how these changes present in women are currently unknown. To determine biomechanical gait differences between women with FAIS or labral tears and control individuals preoperatively and at 3 and 6 months postoperatively. Case-control study. Laboratory. A total of 18 female participants comprising 9 women in the FAIS group (age = 31.44 ± 7.47 years, height = 1.73 ± 0.08 m, mass = 73.61 ± 14.44 kg) and 9 women in the control group (age = 31.44 ± 6.65 years, height = 1.69 ± 0.06 m, mass = 60.93 ± 5.58 kg). Between-groups comparisons of the Hip Outcome Score Activities of Daily Living subscale (HOSADL) and gait biomechanics were conducted preoperatively and at the 3- and 6-month postoperative sessions. Statistical parametric mapping was performed on normalized time-series data. Preoperatively, the FAIS group had poor HOSADL scores (FAIS group = 64.1 ± 15.4 versus control group = 100.0 ± 0, P < .001), walked 15% slower, and exhibited several gait differences compared with the control group. Three months postoperatively, the FAIS group displayed greater vertical ground reaction force (P = .01), ankle-dorsiflexion angle (P = .02), and external dorsiflexion moment (P = .01) in midstance, as well as a greater knee-flexion angle through the second half of stance (P < .001). The FAIS group also demonstrated less hip-extension angle (P = .02) and hip-abduction angle (P = .01) through the second half of stance, which transitioned into less hip extension (P = .040) and hip abduction (P = .03) during the subsequent swing phase. The FAIS group improved their HOSADL to 87.6 ± 7.6 by 6 months postoperatively and had a greater dorsiflexion moment (P = .003) and ankle external rotation during stance (P = .03). In addition, the FAIS group showed a greater external hip external-rotation moment in late stance (P < .001). The biomechanical differences between groups were most evident at 3 months postoperatively, suggesting that women with FAIS had more postoperative gait compensations in the short term after surgery. By 6 months postoperatively, patient-reported outcomes had markedly improved, and the FAIS group displayed few gait differences compared with the control group.

Dynamic Assessment of Femoroacetabular Impingement Syndrome Hips

The purpose of our study was to compare lower extremity rotational kinematics and kinetics (angles, torques, and powers) and hip muscle electromyography (EMG) activity between cam-type femoroacetabular impingement syndrome (FAIS) and age- and sex-matched controls during walking, fast walking, stair ascent, stair descent, and sit-to-stand. This study included 10 males with unilateral FAIS and 10 control males with no FAIS. We measured kinematics, kinetics, and electromyographic signals during stair ascent/descent, sit-to-stand, self-selected walk, and fast walk. Peak signal differences between groups were compared with independent t-tests with statistical significance when P < .05. FAIS hips showed significant differences compared to controls, including increased hip flexion during walking (+4.9°, P= .048) and stair ascent (+7.8°, P=.003); diminished trunk rotation during stair ascent (-3.4°; P= .015), increased knee flexion during self-selected walking (+5.1°, P= .009), stair ascent (+7.4°, P= .001), and descent (+5.3°, P= .038); and increased knee valgus during fast walking (+4.7°, P= .038). gMed and MedHam showed significantly decreased activation in FAIS during walking (gMed:-12.9%, P= .002; MedHam:-7.4%, P= .028) and stair ascent (gMed:-16.7%, P= .036; MedHam:-13.0%, P= .041); decreased gMed activation during sit-to-stand (-8.8%, P=.004) and decreased MedHam activation during stair descent (-8.0%, P= .039). Three-dimensional motion analysis and EMG evaluation of functional kinematics and kinetics in subjects with symptomatic unilateral cam-type FAIS across a spectrum of provocative tasks demonstrated significant differences compared to controls in hip flexion, trunk rotation, knee flexion, and valgus. FAIS hips had significantly decreased gMed and MedHam activity. These findings may explain altered torso-pelvic, hip, and knee mechanics in FAIS patients and suggest that evaluation of FAIS should include the patient's hip, knee, and torso-pelvic relationships and muscle function. The clinical and functional manifestation of FAIS hip pathomechanics is not entirely understood, and previous literature to date has not clearly described the alterations in gait and functional movements seen in patients with cam-type FAIS. The current study used 3D motion analysis and EMG evaluation of functional kinematics and kinetics to identify a number of differences between FAIS and control hips, which help us better understand the lower extremity kinematics and kinetics and muscle activation in FAIS.

Use of Younger Patient Age and Greater Anterior Center-Edge Angle to Predict the Need for Bilateral Hip Arthroscopy in Patients With Bilateral Femoroacetabular Impingement–Related Hip Pain

Background: In patients with symptomatic femoroacetabular impingement syndrome, bilateral hip pain has been reported to occur in high frequency. However, not all patients require bilateral hip arthroscopy. Purpose: To determine the incidence, patient-specific variables, and postoperative outcomes in patients who presented with bilateral hip pain at the time of index hip arthroscopy and underwent subsequent contralateral arthroscopic hip surgery. Study Design: Case series; Level of evidence, 4. Methods: Patients who presented with bilateral hip pain, underwent primary hip arthroscopy between January 2012 and June 2018 for indication of femoroacetabular impingement syndrome, and had minimum 2-year follow-up were retrospectively analyzed. Baseline descriptive data, preoperative hip range of motion, and radiographic measurements were recorded with pre- and postoperative patient-reported outcomes (PROs). Independent samples t test was used to compare continuous variables, and chi-square test was used to compare categorical variables between patients undergoing unilateral and bilateral surgery. Bivariate correlations and a multivariable binary logistic regression were performed to determine factors predictive of the need for future contralateral hip arthroscopy. Results: In total, 108 patients were identified who reported bilateral hip pain during the index evaluation, underwent primary hip arthroscopy, and had 2-year follow-up. Among these, 42% (n = 45) elected to undergo hip arthroscopy on the contralateral hip at a mean of 6.0 months (range, 1-17 months) after the index surgery. Patients requiring bilateral surgery were significantly younger (P = .004) and had a larger preoperative anterior center-edge angle (ACEA; P = .038) when compared with patients who had unilateral surgery. There were no significant differences in alpha angle measurements between patients who had unilateral and bilateral surgery. On bivariate analysis, younger age at the time of the index surgery (r = −0.272; P = .005) and preoperative ACEA (r = 0.249; P = .016) were significantly correlated with the need for bilateral surgery. On multivariate analysis, younger age remained a significant predictor for bilateral surgery (odds ratio, 0.95; 95% CI, 0.91-0.99). Patients who underwent bilateral hip arthroscopy reported significant improvement in all PROs (P < .001), with a significantly greater mean Hip Outcome Score− Sports Specific Subscale score when compared with patients undergoing unilateral surgery (P = .037). Conclusion: Subsequent contralateral hip arthroscopy was performed in 42% of patients who presented with bilateral hip pain. Younger age at the time of the index surgery and greater ACEA were predictive of the need for contralateral surgery. Patients undergoing bilateral surgery reported significantly improvement in PROs at minimum 2-year follow-up.

High Rate of Full Duty Return to Work After Hip Arthroscopy for Femoroacetabular Impingement Syndrome in Workers Who Are Not on Workers’ Compensation

Background: Femoroacetabular impingement syndrome (FAIS) is an increasingly common diagnosis among working-age adults. Hip arthroscopy provides reliable improvements in pain and may allow patients to return to physical activities. No study to date has evaluated return to work (RTW) among a general population of adults after arthroscopic surgery for FAIS. Purpose: To evaluate (1) patients’ rate of RTW, (2) time required to RTW, and (3) factors correlated with time required to RTW after arthroscopic surgery for symptomatic FAIS. Study Design: Case series; Level of evidence, 4. Methods: Consecutive patients aged 25 to 59 years who underwent arthroscopic surgery for FAIS between June 2018 and December 2018 were reviewed. Workers’ compensation cases and patients with <1-year follow-up were excluded. The following were collected at a minimum of 1 year postoperatively: demographics, employment characteristics, Hip Outcome Score (HOS; Activities of Daily Living and Sports Specific subscales), modified Harris Hip Score, 12-Item International Hip Outcome Tool (iHOT-12), visual analog scale for pain, and RTW characteristics. Work physical activity level was classified as sedentary, light, moderate, heavy, or very heavy per established criteria. Results: A total of 97 patients were selected through inclusion and exclusion criteria. RTW surveys were collected for 79 (81.4%), and 61 were employed preoperatively. Time worked per week was 42.8 ± 12.5 hours (mean ± SD). Patients’ work level was most commonly classified as sedentary (42.6%), followed by moderate (24.6%). All 61 (100%) patients returned to work at a mean 7.3 weeks (range, <1-88 weeks) postoperatively. Sixty patients (95.2%) returned to full duty. Time required to full duty RTW was strongly correlated with expected time off from work (r = 0.900; P < .0001) and moderately correlated with work classification (r = 0.640; P = .0001). All patients had significant pre- to postoperative improvements in the HOS–Activities of Daily Living (64.8 ± 15.3 to 87.1 ± 12.2; P < .001), HOS–Sports Specific (42.8 ± 18.8 to 76.7 ± 16.5; P < .001), iHOT-12 (31.3 ± 18.8 to 69.3 ± 21.1; P < .001), modified Harris Hip Score (61.8 ± 12.1 to 80.3 ± 14.1; P < .001), and visual analog scale for pain (5.19 ± 2.11 to 2.40 ± 1.96; P < .001). Conclusion: Patients undergoing arthroscopic treatment for FAIS demonstrated a high rate of RTW at a mean of <2 months postoperatively. A patient’s expected time off from work and the level of physical demands required for work were highly associated with time required to RTW. These results are valuable for orthopaedic surgeons, patients, and employers when establishing a timeline for expected RTW after surgery.

Arthroscopy versus nonoperative treatment of symptomatic femoroacetabular impingement syndrome: A systematic review and meta-analysis.

Background:Presently, hip arthroscopy is a widely adopted surgical intervention for the treatment of femoroacetabular impingement (FAI). However, there is insufficient evidence regarding which between arthroscopy and nonoperative treatment is more optimal for symptomatic FAI.Methods:MEDLINE, Embase, Web of Science, and the Cochrane Library were systematically searched for studies that compared arthroscopy and nonoperative interventions for FAI treatment from inception to August 4, 2020. We included studies that directly compared surgical and nonsurgical treatment for symptomatic FAI and excluded those that did not use arthroscopic treatment as a surgical technique and studies performed on patients with concomitant diagnoses instead of pure FAI. We compared the following clinical outcome scores at 6 and 12 months of follow-up: International Hip Outcome Tool 33 (iHOT-33), hip outcome score (HOS), EuroQol-visual analog scale (EQ-VAS), modified Harris hip score (mHHS), and nonarthritic hip score (NAHS).Results:Five studies totaling 838 patients were included in the qualitative and quantitative synthesis; 382 patients underwent hip arthroscopy, and 456 patients were treated by nonoperative interventions. At 6 months of follow-up, there were no statistically significant differences in iHOT-33 ratings (mean difference [MD] = 7.92, P = .15), HOS (MD of HOS-ADL = 5.15, P = .26 and MD of HOS-Sports = 2.65, P = .79, respectively), and EQ-VAS (MD = 1.22, P = .76) between the 2 treatment strategies. At 12 months of follow-up, the arthroscopy group had a greater mean improvement in iHOT-33 score than the conservative treatment group (MD = 8.42, P = .002), but there was no difference between the groups in terms of mHHS rating (MD = −0.24, P = .83) and NAHS (MD = −2.08, P = .09).Conclusion:Despite arthroscopy being associated with significantly superior iHOT-33 scores after 12 months of follow-up, we were unable to discern the difference between the treatment strategies using other scoring methods, such as HOS, EQ-VAS, mHHS, and NAHS. Further studies will be needed to conclusively determine if 1 strategy is superior to the other for treating FAI.

Assessment of Hip Translation In Vivo in Patients With Femoracetabular Impingement Syndrome Using 3-Dimensional Computed Tomography

PurposeTo determine the 3-dimensional (3D) in vivo hip translation in patients with symptomatic femoroacetabular impingement syndrome (FAIS) using 3D computed tomography (CT) models with the hip in neutral and FABER (flexion, abduction, and the external rotation) positions and to identify patient predictors associated with the degree of hip translation.MethodsSeventy-eight patients with FAIS and cam lesions underwent CT scans in neutral and FABER positions. Demographics including age, sex, and body mass index (BMI) were recorded for each patient. The cam deformity was characterized both in plain x-ray film and 3D. Translation between both positions was calculated using a validated high-precision 3D-3D registration technique. Univariate and multivariate regression analyses sought factors correlated with translation.ResultsThe mean age of the patients included in the analysis was 36.3 ± 9.2 years, with 51% of the study group being female. The mean 3D femoral head center translation was 0.84 ± 0.37 mm, decomposed into vectors on standard anatomical directions as 0.13 ± 0.58 mm medial, 0.10 ± 0.54 mm posterior, and 0.08 ± 0.46 mm inferior. Multivariate analysis demonstrated that total translation was associated with larger alpha angles (β = 0.014; 95% confidence interval [CI] 0.003-0.024; P = .013), and greater BMI (β = 0.033; 95% CI 0.001-0.065; P = .042). Furthermore, posterior–inferior translation was associated with BMI (β = 0.032; 95% CI 0.003-0.061; P = .031), whereas medial–lateral translation is associated with the female sex (β = 0.388; 95% CI 0.124-0.634; P = .002), and smaller head radius (β = –0.068; 95% CI –0.128 to –0.007; P = .029).ConclusionsAs a provocative maneuver, FABER positioning in patients with FAIS resulted in an average measurable translation of the femoral head center in the posterior, medial, and inferior direction. Factors including sex, BMI, and alpha angle predicted the degree of translation.Clinical RelevanceThe current study demonstrates that there is measurable hip translation between the neutral and FABER positions in patients with symptomatic FAIS, which may cause hip microinstability. Furthermore, the study found an association between hip translation and both modifiable and nonmodifiable factors. This may indicate the need for more comprehensive preoperative surgical planning, intraoperative dynamic examination of the hip, and consideration of capsular plication in certain patients.

Leg dominance as a risk factor for femoroacetabular impingement syndrome.

One etiological factor of femoroacetabular impingement syndrome (FAIS) is high impact athletics involving deep hip flexion, axial loading and jumping during skeletal development. Previous work has established that there is physiologic asymmetry of the lower limbs regarding function, with the dominant limb being primarily responsible for propulsion and kicking while the non-dominant limb is responsible for stability and planting. The authors hypothesize that the dominant limb will be more likely to undergo hip arthroscopy for symptomatic FAIS. Four hundred and sixty-nine patients at a single surgical center who underwent primary or revision hip arthroscopy for cam-type FAIS were identified. Patients were asked to identify their dominant lower extremity, defined as the lower extremity preferred for kicking. Sixty patients who indicated bilateral leg dominance were excluded. It was assumed that with no association between limb dominance and the need for surgery, the dominant side would have surgery 50% of the time. Enrichment for surgery in the dominant limb was tested for using a one-sample test of proportions, determining whether the rate differed from 50%. The enrichment for surgery on the dominant side was 57% (95% confidence interval 52–62%) which was significantly different from the rate expected by chance (50%), P = 0.003. No other significant differences were noted between groups. Limb dominance appears to be an etiological factor in the development of cam-type FAIS. Patients are more likely to undergo arthroscopic treatment of FAIS on their dominant lower extremity, although the non-dominant lower extremity frequently develops FAIS as well.

Return to Pilates following hip arthroscopy for treatment of femoroacetabular impingement syndrome

AbstractThe Pilates Method is a common exercise program which focuses on strength, flexibility and control of the body. While the effects of Pilates have been shown to benefit, limited research has investigated its effect on patients with symptomatic femoroacetabular impingement syndrome (FAIS). As such, the purpose of this study was to examine the rate of return to Pilates following hip arthroscopy after undergoing hip arthroscopy for FAIS. The study evaluated consecutive patients who identified themselves as participating in Pilates and had undergone hip arthroscopy for the treatment of FAIS by a single fellowship-trained surgeon between 2012 and 2015 were reviewed. Demographic data, baseline physical examination, imaging, pre- and postoperative patient-reported outcome scores at a minimum of 2-years following surgery as well as a Pilates-specific questionnaire were assessed for all patients. A total of 25 patients (all female) with mean age 38 ± 11 years were identified. Preoperatively, 12 patients had discontinued Pilates due to activity-related hip complaints, 11 patients had scaled back involvement, and 2 patients maintained their baseline routine. Postoperatively, 23 of 25 patients (92%) returned to Pilates at an average of 7.7 ± 4.2 months following surgery (range, 3–14 months). Postoperatively, 96% returned to Pilates at the same level or better than preinjury. Preinjury and postoperative involvement in Pilates were comparable (2.2 h v. 1.8 h per week, P = 0.8). Loss of interest and fear of reinjury were the most common reasons for reduced Pilates involvement. All patients had significant improvements in HOS-ADL (pre 56.52 ± 21.6; post 86.1 ± 18.8; P &lt; 0.001), HOS-SS (30.1 ± 20.0, 63.8 ± 34.8; P &lt; 0.001), mHHS scores (57.6 ± 12.8; 79.2 ± 19.6; P &lt; 0.001), and VAS pain (68.8 ± 15.4; 21.4 ± 26.5; P &lt; 0.001). In conclusion, arthroscopic treatment of FAIS in Pilates participants resulted in significant improvements in hip function and predictably high rates of satisfaction.

Mirror Image Modeling of Acetabular Rim Thickness Differences in Patients With Unilateral Femoroacetabular Impingement Syndrome

PurposeTo use mirror imaging to identify the location and magnitude of difference in acetabular rim morphology between the symptomatic and unaffected acetabula in patients with symptomatic unilateral pincer-type or mixed femoroacetabular impingement syndrome (FAIS) using 1-dimensional models created with computed tomography (CT).MethodsCT scans of bilateral hips in 33 patients diagnosed with unilateral pincer-type or mixed FAIS were obtained. Three-dimensional bilateral hip models were constructed, and the unaffected hemipelvis was superimposed onto the symptomatic side to compare acetabular thickness. Protrusion of the symptomatic side was recorded, and rim morphology was divided into clock face quadrants to analyze the location of greatest magnitude of difference between affected and unaffected acetabula. Analysis of the quadrants was performed using analysis of variance with post hoc Bonferroni correction.ResultsThe study group consisted of more females (51.6%) than males, with an average age of 35.72 ± 7.8 years and an average body mass index of 24.3 ± 4.1 kg/m2. Of the 33 hips included, 14 were isolated pincer-type FAIS and 19 were mixed. The average preoperative symptomatic side lateral center edge angle was 37.5° ± 7.2° compared with 29° ± 5.1° on the asymptomatic side (P = .001). The symptomatic acetabular rim was on average 0.43 ± 0.18 mm thicker than the corresponding location on the unaffected rim. When the acetabulum was divided into clock face quadrants, the 12 to 3 o'clock position showed the greatest difference between symptomatic and unaffected sides (0.55 ± 0.18 mm) compared with the 3 to 6 o'clock position (0.4 ± 0.28 mm; P = .006), 6 to 9 o'clock (0.34 ± 0.07 mm; P < .001), and 9 to 12 o'clock (0.38 ± 0.03; P = .001).ConclusionsPatients with unilateral, symptomatic pincer-type or mixed FAIS show statistical differences in rim thickness between the affected and unaffected acetabula. Small changes in acetabular rim morphology on the order of ≤0.5 mm may be the difference between symptomatic FAIS and the unaffected hip.Level of EvidenceIV, case series.

Hip Arthroscopy for Femoroacetabular Impingement Syndrome Performed with Modern Surgical Techniques Provides High Survivorship and Durable Outcome

Objectives: To analyze predictors of clinical failure as defined by revision hip arthroscopy or conversion to total hip arthroplasty (THA) as well as predictors of inferior outcomes defined as the not reaching Minimally Clinical Important Difference (MCID) or Patient Acceptable Symptomatic State (PASS) for Hip Outcome Score-Activities of Daily Living Subscale (HOS-ADL). Methods: Prospective data on all patients who underwent primary hip arthroscopy with routine capsular closure for the treatment of femoroacetabular impingement syndrome (FAIS) by a single, fellowship-trained surgeon between January 2012 and November 2015 were collected and analyzed. Inclusion criteria consisted of clinical and radiographic diagnosis of symptomatic FAIS, failed conservative management, and undergoing hip arthroscopy to correct FAIS with a minimum of two-year follow-up. Exclusion criteria consisted of prior ipsilateral hip surgery and hip arthroscopy for an indication other than FAIS. Baseline demographic data and radiographic parameters were collected and patient-reported outcomes (PROs) were obtained at baseline and at a minimum of two-years postoperatively. Rates of clinical failure and inferior clinical outcomes were recorded at a minimum of two-years postoperatively then stepwise linear regression was used to identify patient-related and imaging-related factors as predictors of each, respectively. Results: Out of 1,161 eligible patients, 949 (81.7%) completed PROs at a minimum of two-years postoperatively. The average age was 32.8 ± 12.4 years with a mean BMI of 25.4 ± 10.7 kg/m2. The overall clinical failure rate was 2.2% (n=21) including eleven cases of revision hip arthroscopy and eleven cases of conversion to THA (one patient underwent revision then subsequent THA). The inferior clinical outcome group consisting of patients who failed to reach MCID for HOS-ADL included164 patients while those who failed to reach PASS for HOS-ADL included 353 patients. In the regression model, poor articular cartilage, hypertension, lateral rim impingement on physical exam, history of back pain/spine pathology, limp on presentation, decreased daily physical activity, greater preoperative alpha angle, weakness in abduction with knees extended, and prolonged symptom duration were predictive of clinical failure (all p-values&lt;0.05). Predictors of failing to reach MCID for HOS-ADL included: prolonged symptom duration, history of back pain/spine pathology, Tonnis grade &gt;1, being a current/former smoker, pain with ischial palpation, lateral rim impingement, snapping iliotibial band, and pain with resisted sit-up and over the greater trochanter. Predictors of failing to reach PASS for HOS-ADL included: prolonged symptom duration, decreased daily physical activity, workman’s compensation, history of anxiety and/or depression, snapping iliotibial band, limp on examination, and pain with palpation of the spine/sacroiliac joint (all p-values&lt;0.05). Conclusion: The clinical failure rate of hip arthroscopy may be lower than previously reported. Reoperation is predicted by medical comorbidity, lack of preoperative athletic activity, and multiple positive physical exams. Inferior clinical outcomes are predicted by prolonged symptom duration, back pain, being a current/former smoker, a history of a psychiatric comorbidity, as well as numerous signs on physical examination.

Femoroacetabular Impingement in the Adolescent Athlete

Femoroacetabular impingement syndrome (FAIS) is a source of hip pain that can present in adolescent athletes and is related to sports participation and extreme use in these patients. FAIS is characterized by morphologic abnormalities of the acetabulum and/or proximal femur that leads to pathologic contact within the hip joint. FAIS is classified as cam-type, pincer-type, or combined. Early sports participation is a factor in the development of symptomatic FAIS. Adolescent patients with FAIS are also more likely to have associated extra-articular pathologies. History and physical exam findings in adolescents with FAIS are not considerably different than corresponding findings in adults with FAIS and include activity-related groin pain aggravated by pivoting and flexion activities. FAIS can be treated conservatively or surgically. In refractory cases, outcomes after surgical intervention have been shown to be significantly better than nonsurgical treatment. Surgical intervention involves repairing damage to the labrum and/or cartilage and decompressing the bony impingement. Open and arthroscopic approaches have been shown to be safe and effective in adolescents with good outcomes. Most adolescent athletes are able to return to participation in their sport and a majority returning to their preinjury level of play after surgical intervention.