Imaging Modalities in the Preoperative Assessment of Femoroacetabular Impingement and Hip Dysplasia: Determining Best Practices.

¼ In the last decade, significant progress has been made in understanding hip pain, especially related to femoroacetabular impingement (FAI) and hip dysplasia (HD), which collectively affect over 20% of the population.¼ Preoperative imaging, including plain radiographs, computed tomography (CT), magnetic resonance imaging (MRI), and ultrasound (US), plays a pivotal role in diagnosing FAI and HD. Imaging precision, standardized techniques, and accurate interpretation are crucial for effective treatment planning.¼ The continual advancements in imaging techniques, especially seen in MRI (arthrograms, application of leg traction, and delayed gadolinium-enhanced MRI of cartilage), represent important strides in the precise assessment of pathology associated with FAI and HD.¼ By incorporating these advancements into routine imaging protocols, healthcare providers can ensure a comprehensive understanding of hip joint dynamics, enabling more accurate diagnosis and effective management strategies for patients with FAI and HD, ultimately leading to improved clinical outcomes.

Predictive Factors for Intraoperative Determination for the Need of Femoral Osteochondroplasty After Periacetabular Osteotomy for Acetabular Dysplasia.

Background: Determination of need for osteochondroplasty (OCP) during periacetabular osteotomy (PAO) commonly relies on intraoperative assessment of internal rotation at 90° flexion (IRF). Performing an OCP helps decrease the risk of iatrogenic femoroacetabular impingement from PAO reduction. Avoiding impingement helps decrease risks of accelerated secondary osteoarthritis. The literature is limited for factors that predict need for OCPs during PAOs. The purpose of this study was to (1) define the characteristics of patients needing concurrent OCP and provide OCP rate based on IRF and femoral version and (2) identify predictive factors (clinical, radiographic) associated with need for OCP during PAO. As some surgeons determine need for OCP pre-operatively, predictive factors would aid decision making. Methods: This was a prospective cohort of 224 hips (207 patients) who underwent PAO for symptomatic acetabular dysplasia, of which 154 hips (69%) underwent OCP between years 2013 and 2017. Patients underwent OCP if they had restrictions in motion or impingement intra-operatively. Pre-operative factors such as age, sex, BMI, and CT findings were recorded that underwent univariate and multivariable analyses. Multivariable analysis found predictors that were described using odds ratios and 95% confidence intervals. IRF>30° and femoral version 10°-25° were used as the reference groups during categorical analysis. P-values ≤0.05 were considered significant. Results: Alpha angles >55° (OR= 2.20, CI: 1.08-4.52, p= 0.03), IRF≤20° (OR: 9.52, CI: 3.87-23.40, p<0.001), IRF >20°-30° (OR: 2.68, CI: 1.08-6.62, p=0.03), and femoral version <10° (OR: 5.26, CI: 1.09-25.30, p=0.04) were associated with increased odds of OCP. On continuous modeling, decreasing femoral version (OR: 1.07, CI: 1.02-1.12, p=0.002) and IRF (OR: 1.06, CI: 1.03-1.09, p<0.001) were associated with increased chance of OCP. For 5° changes, the chance of OCP increased by 40% (OR: 1.40, CI: 1.13-1.73, p=0.002) and 35% (OR: 1.35, IC: 1.16-1.57, p<0.001), respectively. Conclusion: Awareness of need for OCP may be valuable in peri-operative planning for these patients especially since some surgeons perform this technique arthroscopically before PAO. Factors associated with increased chances of OCP were alpha angles >55°, decreased IRF, and decreased femoral version. More studies in the future would help determine how OCP affects patient outcomes. Level of Evidence: III.

Improving Patient Understanding of Femoroacetabular Impingement Syndrome With Three-Dimensional Models.

INTRODUCTION: Three-dimensional (3D) printed models may help patients understand complex anatomic pathologies such as femoroacetabular impingement syndrome (FAIS). We aimed to assess patient understanding and satisfaction when using 3D printed models compared with standard imaging modalities for discussion of FAIS diagnosis and surgical plan. METHODS: A consecutive series of 76 new patients with FAIS (37 patients in the 3D model cohort and 39 in the control cohort) from a single surgeon's clinic were educated using imaging and representative 3D printed models of FAI or imaging without models (control). Patients received a voluntary post-visit questionnaire that evaluated their understanding of the diagnosis, surgical plan, and visit satisfaction. RESULTS: Patients in the 3D model cohort reported a significantly higher mean understanding of FAIS (90.0 ± 11.5 versus 79.8 ± 14.9 out of 100; P = 0.001) and surgery (89.5 ± 11.6 versus 81.0 ± 14.5; P = 0.01) compared with the control cohort. Both groups reported high levels of satisfaction with the visit. CONCLUSION: In this study, the use of 3D printed models in clinic visits with patients with FAIS improved patients' perceived understanding of diagnosis and surgical treatment.

Effect of Spinopelvic Parameters on Outcomes After Hip Arthroscopy for Femoroacetabular Impingement Syndrome.

BACKGROUND: Spinopelvic parameters, including pelvic tilt (PT), sacral slope (SS), and pelvic incidence, have been developed to characterize the relationship between lumbar spine and hip motion, but a paucity of literature is available characterizing differences in spinopelvic parameters among patients with femoroacetabular impingement syndrome (FAIS) versus patients without FAIS, as well as the effect of these parameters on outcomes of arthroscopic treatment of FAIS. PURPOSE: To (1) identify differences in spinopelvic parameters between patients with FAIS versus controls without FAIS; (2) identify associations between spinopelvic parameters and preoperative patient-reported outcomes (PROs); and (3) identify differences in PROs between patients with stiff spines (standing-sitting ΔSS ≤10°) versus those without. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: The study enrolled patients ≥18 years of age who underwent primary hip arthroscopy for treatment of FAIS with cam, pincer, or mixed (cam and pincer) morphology. Participants underwent preoperative standing-sitting imaging with a low-dose 3-dimensional radiography system and were matched on age and body mass index (BMI) to controls without FAIS who also underwent EOS imaging. Spinopelvic parameters measured on EOS films were compared between the FAIS and control groups. Patients with FAIS completed the modified Harris Hip Score (mHHS) and Non-Arthritic Hip Score (NAHS) before surgery and at 1-year follow-up. Outcome scores were compared between patients with stiff spines versus those without. Associations between spinopelvic parameters and baseline outcome scores were assessed with Pearson correlations. Continuous variables were compared with Student t test and/or Mann-Whitney U test, and categorical variables were compared with Fisher exact test. RESULTS: A total of 50 patients with FAIS (26 men; 24 women; mean age, 36.1 ± 10.7 years; mean BMI, 25.6 ± 4.2) were matched to 30 controls without FAIS (13 men; 17 women; mean age, 36.6 ± 9.5 years; mean BMI, 26.7 ± 3.6). Age, sex, and BMI were not significantly different between the FAIS and control groups (P > .05). Standing PT was not significantly different between stiff and non-stiff cohorts (P = .73), but sitting PT in the FAIS group was more than double that of the control group (36.5° vs 15.0°; P < .001). Incidence of stiff spine was significantly higher in the FAIS group (62.0% vs 3.3%; P < .001). Among FAIS patients, those with stiff spines had a significantly higher prevalence of cam impingement, whereas those with non-stiff spines had a higher prevalence of mixed impingement (P = .04). No significant differences were seen in preoperative mHHS or NAHS scores or pre- to postoperative improvement in scores between FAIS patients with stiff spines versus those without (P > .05), but a greater sitting SS was found to be positively correlated with a higher baseline mHHS (r = 0.36; P = .02). CONCLUSION: Patients with FAIS were more likely to have a stiff spine (standing-sitting ΔSS ≤10°) compared with control participants without FAIS. FAIS patients with stiff spines were more likely to have isolated cam morphology than patient without stiff spines. Although sitting SS was positively correlated with baseline mHHS, no significant differences were seen in 1-year postoperative outcomes between FAIS patients with versus without stiff spine.

Mid-term results of autologous matrix-induced chondrogenesis for large chondral defects in hips with femoroacetabular impingement syndrome.

Aims: The purpose of this study was to evaluate the mid-term outcomes of autologous matrix-induced chondrogenesis (AMIC) for the treatment of larger cartilage lesions and deformity correction in hips suffering from symptomatic femoroacetabular impingement (FAI). Methods: This single-centre study focused on a cohort of 24 patients with cam- or pincer-type FAI, full-thickness femoral or acetabular chondral lesions, or osteochondral lesions ≥ 2 cm2, who underwent surgical hip dislocation for FAI correction in combination with AMIC between March 2009 and February 2016. Baseline data were retrospectively obtained from patient files. Mid-term outcomes were prospectively collected at a follow-up in 2020: cartilage repair tissue quality was evaluated by MRI using the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score. Patient-reported outcome measures (PROMs) included the Oxford Hip Score (OHS) and Core Outcome Measure Index (COMI). Clinical examination included range of motion, impingement tests, and pain. Results: A total of 12 hips from 11 patients were included (ten males, one female, mean age 26.8 years (SD 5.0), mean follow-up 6.2 years (SD 5.2 months)). The mean postoperative MOCART score was 66.3 (SD 16.3). None of the patients required conversion to total hip arthroplasty. Two patients had anterior impingement. External hip rotation was moderately limited in four patients. There was a correlation between MOCART and follow-up time (rs = -0.61; p = 0.035), but not with initial cartilage damage, age, BMI, or imaging time delay before surgery. PROMs improved significantly: OHS from 37.4 to 42.7 (p = 0.014) and COMI from 4.1 to 1.6 (p = 0.025). There was no correlation between MOCART and PROMs. Conclusion: Based on the reported mid-term results, we consider AMIC as an encouraging treatment option for large cartilage lesions of the hip. Nonetheless, the clinical evidence of AMIC in FAI patients remains to be determined, ideally in the context of randomized controlled trials.

Femoroacetabular Variations Are Predisposing Factors for Traumatic Posterior Hip Dislocation.

BACKGROUND: Although high-energy trauma mechanisms are generally considered to cause traumatic posterior hip dislocations, femoroacetabular variations are assumed to contribute to low-impact hip dislocations. Thus, the present study aimed to identify morphologic femoral and acetabular risk factors that may also contribute to posterior hip dislocations in high-energy trauma mechanisms. METHODS: The acetabular and femoral morphology of 83 hips with a traumatic posterior dislocation following a high-energy trauma mechanism were analyzed and matched to a control group of 83 patients who sustained high-energy trauma without a hip injury. The lateral center-edge angle, acetabular index, acetabular depth/width ratio, cranial and central acetabular version angles, and the anterior and posterior acetabular sector angles were measured on computed tomography to quantify femoroacetabular impingement (FAI) morphology, acetabular version, and coverage. The caput-collum-diaphyseal angle and the alpha angles in the coronal and axial planes were measured to detect cam-type FAI deformity. A receiver operating characteristic curve was utilized to determine threshold values for an increased risk of hip dislocation. RESULTS: Acetabular retroversion and posterior acetabular undercoverage were significantly increased in patients with hip dislocations compared with controls (p < 0.001). The central acetabular version angle and posterior acetabular sector angle that indicated an increased risk of hip dislocation were ≤9° and ≤90°, respectively. Cam-type FAI deformity and coxa valga were significantly increased in the dislocation group (p < 0.001). The anterolateral alpha angle that indicated an increased dislocation risk was ≥47°. CONCLUSIONS: Acetabular retroversion, posterior acetabular undercoverage, and cam-type FAI morphology may be risk factors contributing to traumatic posterior hip dislocation in high-energy trauma mechanisms. LEVEL OF EVIDENCE: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Computer-Assisted Arthroscopic Cam Resection.

Determining the appropriate femoral cam resection during hip arthroscopy for femoroacetabular impingement syndrome is both critical for the patient and challenging for the surgeon. Incomplete bone resection is a leading cause of failed hip arthroscopy, whereas over-resection may increase the risk of femoral neck fracture. The alpha angle is a validated 2-dimensional radiographic measurement used to both diagnose femoroacetabular impingement syndrome preoperatively and to determine resection adequacy postoperatively. Computer-assisted intraoperative guidance systems enhance the accuracy of femoral cam resection, although a preoperative 3-dimensional computed tomography scan may be required. Other systems, such as the HipCheck software (Stryker, Kalamazoo, MI), have been developed to provide intraoperative guidance with live feedback using simultaneous alpha angle measurements overlayed on fluoroscopic images without the requirement for routine preoperative computed tomography. Via intraoperative touchscreen navigation, the surgeon identifies the midpoint of the femoral neck and femoral head. A commercial software program provides real-time alpha angle measurements, as well as enhanced visualization of the femoral cam deformity with an adjustable resection curve. Before the surgeon performs the cam resection, the software provides a template for appropriate resection depth in 6 positions of the hip. Upon completion of the femoral cam resection, the hip is again assessed in the same 6 positions and the alpha angle is assessed to ensure a complete resection.

Modern Hip Arthroscopy for FAIS May Delay the Natural History of Osteoarthritis in 25% of Patients: A 12-Year Follow-up Analysis.

BACKGROUND: Little is known about the effect of modern hip arthroscopy on the natural history of femoroacetabular impingement syndrome (FAIS) with respect to joint preservation. PURPOSE: To (1) characterize the natural history of FAIS and (2) understand the effect of modern hip arthroscopy by radiographically comparing the hips of patients who underwent only unilateral primary hip arthroscopy with a minimum follow-up of 10 years. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Between 2010 and 2012, 619 consecutive patients were reviewed from the practice of a single fellowship-trained hip arthroscopic surgeon. Inclusion criteria were FAIS, bilateral radiographic findings of femoroacetabular impingement, primary unilateral hip arthroscopy (labral repair, femoroplasty, or capsular closure), and minimum 10-year follow-up. The preoperative and minimum 10-year postoperative radiographs of patients were evaluated at each time point. Both operative and nonoperative hips were graded using the Tönnis classification or the presence of hip arthroplasty by 2 independent reviewers. Subgroup analyses were performed. RESULTS: A total of 200 hips from 100 patients were evaluated at a mean follow-up of 12.0 years. Preoperatively, 98% and 99% of operative and nonoperative hips were evaluated as Tönnis grades 0 and 1, respectively; 5% of nonoperative hips had worse Tönnis grades than operative hips. The nonoperative hip advanced to a worse Tönnis grade in 48% (48/100) of cases compared with 28% (28/100) among operative hips. At follow-up, Tönnis grades between hips were equal in 70% (70/100) of the cases, the operative hip had a better grade 25% (25/100) of the time, and the nonoperative hip had a better grade 5% (5/100) of the time. Modern hip arthroscopy was associated with a relative risk reduction of 42% in osteoarthritis progression. Impingement with borderline dysplasia, age, preoperative Tönnis grade, and alpha angle >65° were key risk factors in the radiographic progression of osteoarthritis. CONCLUSION: Although the majority of patients (70%) undergoing hip arthroscopy for FAIS did not experience differences between operative and nonoperative hips in terms of the radiographic progression of osteoarthritis, the natural history may be favorably altered for 25% of patients whose Tönnis grade was better after undergoing arthroscopic correction. Modern hip arthroscopy indications and techniques represent a valid joint-preservation procedure conferring a relative risk reduction of 42% in the progression of osteoarthritis. Arthroscopy for mixed patterns of impingement and instability were the fastest to degenerate.

Association Between Chondrolabral Junction Breakdown and Conversion to Total Hip Arthroplasty After Hip Arthroscopy for Symptomatic Labral Tears: Minimum 8-Year Follow-up.

BACKGROUND: Arthroscopic treatment of femoroacetabular impingement (FAI) and symptomatic labral tears confers short- to midterm benefits, yet further long-term evidence is needed. Moreover, despite the physiological and biomechanical significance of the chondrolabral junction (CLJ), the clinical implications of damage to this transition zone remain understudied. PURPOSE: To (1) report minimum 8-year survivorship and patient-reported outcome measures after hip arthroscopy for FAI and (2) characterize associations between outcomes and patient characteristics (age, body mass index, sex), pathological parameters (Tönnis angle, alpha angle, type of FAI, CLJ breakdown), and procedures performed (labral management, FAI treatment, microfracture). STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: This retrospective cohort study included patients who underwent primary hip arthroscopy for symptomatic labral tears secondary to FAI by a single surgeon between 2002 and 2013. All patients were ≥18 years of age with minimum 8-year follow-up and available preoperative radiographs. The primary outcome was conversion to total hip arthroplasty (THA), and secondary outcomes included revision arthroscopy, patient-reported outcome measures, and patient satisfaction. CLJ breakdown was assessed using the Beck classification. Kaplan-Meier estimates and weighted Cox regression were used to estimate 10-year survivorship (no conversion to THA) and identify risk factors associated with THA conversion. RESULTS: In this study of 174 hips (50.6% female; mean age, 37.8 ± 11.2 years) with mean follow-up of 11.1 ± 2.5 years, the 10-year survivorship rate was 81.6% (95% CI, 75.9%-87.7%). Conversion to THA occurred at a mean 4.7 ± 3.8 years postoperatively. Unadjusted analyses revealed several variables significantly associated with THA conversion, including older age; higher body mass index; higher Tönnis grade; labral debridement; and advanced breakdown of the CLJ, labrum, or articular cartilage. Survivorship at 10 years was inferior in patients exhibiting severe (43.6%; 95% CI, 31.9%-59.7%) versus mild (97.9%; 95% CI, 95.1%-100%) breakdown of the CLJ (P < .001). Multivariable analysis identified worsening CLJ breakdown (weighted hazard ratio per 1-unit increase, 6.41; 95% CI, 3.11-13.24), older age (1.09; 95% CI, 1.04-1.14), and higher Tönnis grade (4.59; 95% CI, 2.13-9.90) as independent negative prognosticators (P < .001 for all). CONCLUSION: Although most patients achieved favorable minimum 8-year outcomes, several pre- and intraoperative factors were associated with THA conversion; of these, worse CLJ breakdown, higher Tönnis grade, and older age were the strongest predictors.

Prevalence of hip femoroacetabular impingement deformities in high-level (La Liga) male professional football players.

BACKGROUND: Femoroacetabular impingement (FAI) is considered one of the main causes of hip osteoarthritis in young adults, especially in athletes. In recent years, morphological changes in FAI in the hip have been linked to early and intense sports participation, but studying top-level athlete samples is not easy. This paper presents the prevalence of FAI radiological markers in 120 active white male professional football players in the Spanish First Division League (La Liga) and compares the morphological changes with those of a control group of healthy individuals without significant sport activity. METHODS: The precontract medical evaluation hip X-rays of 120 white male professional football players from four different First Division Spanish football teams were prospectively filed and retrospectively reviewed by a dedicated skeletal radiologist. The footballers' hip X-rays were compared with those of a control group of 80 healthy individuals (age-sex matched) without significant sport activity (obtained from routine work medical checks). RESULTS: The femoral head-neck deformity associated with the Cam type of femoroacetabular impingement was observed in 61.6% of professional football players and only in 11.6% of the control group (p <0.01). The presence of "herniation pit" (11.6%) and os acetabuli (13.3%) also reached statistical significance in the professional football players group. In the other analyzed parameters, no statistically significant differences between the groups were observed. CONCLUSIONS: White professional top-level football players have an increased incidence of abnormal lateral epiphyseal extension ("pistol grip deformity"), os acetabuli and herniation pits.

Cam-type hip morphology in asymptomatic patients.

BACKGROUND: The alpha angle has been widely used in the assessment of cam-type of impingement, but recent studies have shown that this angle may also be high in asymptomatic patients. The aim of this study is to report the prevalence of cam-type morphology in asymptomatic volunteers and explore its correlation with hip clinical and radiological parameters. METHODS: This single-centre prospective study included 48 asymptomatic male volunteers (96 hips). All candidates fulfilled the inclusion and exclusion criteria. Physical examination and 1.5 -T MRI imaging were done for bilateral hips on the same day. Alpha angle measurements were obtained from 4 different positions and cam-type morphology was considered positive using 2 different cut points >55° and >60°. Descriptive statistics were analysed and correlations were performed where appropriate and p-value < 0.05 was considered to be significant. RESULTS: The prevalence of cam-type morphology using alpha angle >55° was 68.8%, 87.5%, 50% and 34.4% in the 12, 1, 2 and 3 o'clock positions respectively. While it was 38.5%, 69.8%, 26% and 12.5% in the 12, 1, 2 and 3 o'clock positions of the studied hips respectively using alpha angle >60°. The maximum alpha angle was more frequently prevalent at the 1 o'clock position in 71 (74%). Labral tear was detected in 26 (27.1%) hips and impingement test was positive in 12 (12.5%) hips. There was no correlation between the presence of cam-type morphology and range of motion of the hip, presence of positive impingement test nor labral tears. CONCLUSIONS: Cam-type morphology prevalence is high among asymptomatic males, and mostly pronounced at the 1 o'clock position. A correlation between high alpha angle and positive impingement test or labral tear was not found in our cohort. Future studies are required to determine the natural history of asymptomatic cam-type morphology and risk of hip derangement.

Comparison of MRI and arthroscopy findings for transitional zone cartilage damage in the acetabulum of the hip joint.

OBJECTIVE: To assess the performance of morphologic and hypointense signal changes on MRI to predict grades and types of acetabular cartilage damage in the chondrolabral transitional zone (TZ) of the hip identified at arthroscopy. MATERIALS AND METHODS: This retrospective single-center study reviewed conventional 3T MRI hip studies from individuals with symptomatic femoroacetabular impingement (FAI) and subsequent hip arthroscopy surgery within 6 months. Independent review was made by three radiologists for the presence of morphologic damage or a hypointense signal lesion in the TZ on MRI. Fleiss' kappa statistic was used to assess inter-reader agreement. The degree of TZ surfacing damage (modified Outerbridge grades 1-4) and presence of non-surfacing wave sign at arthroscopic surgery were collected. Relationship between sensitivity and lesion grade was examined. RESULTS: One hundred thirty-six MRI hip studies from 40 males and 74 females were included (mean age 28.5 years, age range 13-54 years). MRI morphologic lesions had a sensitivity of 64.9-71.6% and specificity of 48.4-67.7% for arthroscopic surfacing lesions, with greater sensitivity seen for higher grade lesions. Low sensitivity was seen for wave sign lesions (34.5-51.7%). MRI hypointense signal lesions had a sensitivity of 26.3-62% and specificity of 43.8-78.0% for any lesion. Inter-reader agreement was moderate for morphologic lesions (k = 0.601) and poor for hypointense signal lesions (k = 0.097). CONCLUSION: Morphologic cartilage damage in the TZ on MRI had moderate sensitivity for any cartilage lesion, better sensitivity for higher grade lesions, and poor sensitivity for wave sign lesions. The diagnostic value of hypointense signal lesions was uncertain.

Sagittal Pelvic Tilt Directly Influences the Ischiofemoral Space: A Cadaveric Study.

BACKGROUND: Ischiofemoral impingement (IFI) is understood to be a pain generator in the deep gluteal space. Femoral position is known to influence the ischiofemoral space (IFS), but there has been no study examining the effect of sagittal pelvic tilt on the IFS. The purpose of this study was to determine whether changes in pelvic tilt in the sagittal plane lead to changes in the dimensions of the IFS. MATERIALS AND METHODS: Five fresh frozen cadavers (10 hips) were used for this anatomic study. The specimens were skeletonized and placed in the prone position with the pelvis fixed to a custom-built hinged table. A digital inclinometer was used to tilt the pelvis -10°, 0°, and 10° simulating posterior, neutral, and anterior pelvic tilt, respectively. Digital calipers were used to measure the dimensions of the IFS in all three positions of sagittal pelvic tilt. RESULTS: Changes in pelvic tilt resulted in significant changes in the dimensions of the IFS. Mean IFS dimensions measured 29.3±9.7 mm, 37.2±9.0 mm, and 24.3±9.2 mm in the neutral, anterior, and posterior pelvic tilt positions, respectively (P<.0001). CONCLUSION: Changes in sagittal pelvic tilt influence the dimensions of the IFS, with posterior pelvic tilt noted to significantly decrease the IFS when compared with neutral and anterior pelvic tilt. These findings suggest that further evaluation of sagittal spinopelvic balance in the etiology of symptomatic IFI may be warranted. [Orthopedics. 2024;47(3):167-171.].

Successful therapy of complex regional pain syndrome after hip arthroscopy for femoroacetabular impingement syndrome: a case report.

BACKGROUND: Complex regional pain syndrome is a neuropathic pain disorder associated with ongoing pain that persists beyond the usual expected tissue healing time and that is disproportionate to the degree of tissue injury present. Complex regional pain syndrome after hip arthroscopy has not been reported before. Hip arthroscopy is a fast-growing domain that could lead to an increasing number of complex regional pain syndrome cases, probably owing to the high traction forces that are necessary. CASE PRESENTATION: We report the case of a 30-year-old German female semiprofessional tennis player who presented with complex regional pain syndrome type I in the lower leg 3 weeks after hip arthroscopy for femoroacetabular impingement syndrome with suture anchor labral repair and femoroplasty. After 2 months of immediate multimodal conservative therapy including administration of gabapentin, prompt full weight-bearing, and intensified physiotherapy, complete recovery was achieved. CONCLUSION: Complex regional pain syndrome does occur after elective hip arthroscopy. Disproportionate postoperative pain or other symptoms raising suspicion of complex regional pain syndrome should be promptly evaluated and treated through a multimodal approach. Postless hip arthroscopy may be advantageous.

Editorial Commentary: Small Labral Size on Magnetic Resonance Imaging Is an Indication for Labral Reconstruction in the Setting of Revision Hip Arthroscopy.

Revision hip arthroscopy is an increasingly common procedure as rates of primary hip arthroscopy rise. Etiologies for symptom recurrence may include residual femoroacetabular impingement, cam over-resection, labral pathology, chondral wear, adhesions, and instability. This has spawned sophisticated surgical techniques in hip arthroscopy including labral reconstruction. Indications for labral reconstruction in the revision setting obviously include labral deficiency. In addition, in the absence of other obvious reasons for failure of the primary procedure, a labral reconstruction should be considered for diminutive labra. The ability to predict labral size before surgery based on magnetic resonance imaging can be invaluable.

Factors associated with cam deformity in Japanese local residents.

Femoroacetabular impingement has increasingly been recognized as a cause of primary hip osteoarthritis; however, its epidemiological indications remain unclear. We aimed to clarify the epidemiological indications and factors associated with cam deformity in a large-scale population-based cohort in Japan. Overall, 1480 participants (2960 hips) (491 men, 989 women; mean age, 65.3 years) analyzed in the third survey of the Research on Osteoarthritis/Osteoporosis Against Disability study were included. The α angle and spinopelvic parameters (lumbar lordosis, sacral slope, pelvic tilt, and pelvic incidence) were radiographically measured. Cam deformity was defined as α angle ≥ 60°. Overall, the cam deformity prevalence was 147/2960 (5.0%). Cam deformity prevalence tended to increase with age; in the univariate analysis, a higher percentage of men was observed in the group with cam deformity than in the group without it. No relationship was observed between cam deformity and hip pain. Factors associated with α angle were examined via multiple regression analysis for each gender; α angle was significantly associated with age and BMI in each gender. The α angle and PT were correlated in women. Thus, α angle and cam deformity prevalence increase with age in Japanese individuals. Accordingly, cam deformity can be considered a developmental disease.

Intermediate-Term Outcomes of Hip Arthroscopy for Femoroacetabular Impingement Syndrome in Patients With Global Versus Isolated Lateral Acetabular Overcoverage.

BACKGROUND: Previous studies evaluating the outcomes of hip arthroscopy for patients with global acetabular overcoverage and focal superolateral acetabular overcoverage suffer from short-term follow-up and inconsistent radiographic criteria when defining these subpopulations of patients with femoroacetabular impingement syndrome (FAIS). PURPOSE: To evaluate the intermediate-term postoperative outcomes for patients with FAIS in the setting of global acetabular overcoverage, lateral acetabular overcoverage, and normal acetabular coverage. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Patients undergoing hip arthroscopy for FAIS were enrolled in a prospective cohort study, and those with a minimum follow-up of 5 years were included in this analysis. Patients were grouped based on type of acetabular coverage: global overcoverage (lateral center-edge angle [LCEA] ≥40°, with coxa profunda), lateral overcoverage (LCEA ≥40°, without coxa profunda), and no overcoverage (LCEA <40°). Functional outcomes (modified Harris Hip Score and Nonarthritic Hip Score) and failure of primary hip arthroscopy were compared between groups. RESULTS: In total, 94 patients (mean age, 41.9 ± 14.2 years) were included with a mean follow-up duration of 6.1 ± 0.9 years. Of these patients, 40.4% had no acetabular overcoverage, 36.2% had lateral overcoverage, and 23.4% had global overcoverage. There was no difference between groups with respect to percentage of patients who underwent reoperation for either revision arthroscopy or conversion to total hip arthroplasty (28.9% for the normal acetabular coverage group, 29.4% for the lateral overcoverage group, and 31.8% for the global overcoverage group; P = .971). Among patients for whom primary hip arthroscopy did not fail, there was no difference in 5-year functional outcomes between groups. Postoperative LCEA >40° (ß = -13.3; 95% CI, -24.1 to -2.6; P = .016), female sex (ß = -14.5; 95% CI, -22.7 to -6.2; P = .001), and higher body mass index (ß = -1.9; 95% CI, -2.8 to -1.0; P < .001) were associated with worse intermediate-term hip function in terms of modified Harris Hip Score. CONCLUSION: There was no difference in functional outcomes or rate of reoperation at a minimum of 5 years postoperatively between those with global acetabular overcoverage, those with regional lateral overcoverage, and those with normal acetabular coverage. Provided that an appropriate acetabuloplasty is performed, there is no evidence to suggest that global acetabular overcoverage portends a worse prognosis than other FAIS subtypes.

Physical Therapy May Not Be Successful for Patients With Cam-Type Femoroacetabular Impingement Syndrome and May Result in Insufficient Hip Range of Motion When Femoral Anteversion Is Less Than 16° and α-Angle Is Greater Than 65°.

PURPOSE: To identify factors associated with insufficient range of motion (ROM) improvement after the posterior pelvic tilt change in cam-type femoroacetabular impingement syndrome. METHODS: Preoperative computed tomography images from 71 consecutive patients with femoroacetabular impingement syndrome treated with arthroscopic cam resection were evaluated. Using a dynamic computer simulation program, 3-dimensional models with a 10° posterior pelvic tilt from the supine functional pelvic plane (baseline) were created by computed tomography models. Patients were divided into 2 groups: those who experienced >10° (effective group) and ≤10° (ineffective group) improvements in internal rotation at 90° flexion after a 10° posterior pelvic tilt. Demographic characteristics; preoperative range of internal rotation at 90° flexion; and radiographic parameters, including Tönnis grade, lateral center-edge angle, acetabular roof obliquity angle, central acetabular anteversion, cranial acetabular anteversion, femoral anteversion, and α angle, were compared in the 2 groups. Univariate and multivariable logistic regression analyses were performed to evaluate factors associated with insufficient ROM improvement following a 10° posterior pelvic tilt. RESULTS: The 71 patients included 58 men and 13 women, of mean age 41.4 ± 14.6 years. Posterior pelvic tilt was effective in 13 hips and ineffective in 58. Univariate analysis showed that preoperative range of internal rotation at 90°flexion, femoral anteversion, and α angle differed significantly in the 2 groups. Multivariable analysis showed that femoral anteversion <16° (odds ratio 7.4; 95% confidence interval 1.6-35; P = .012) and α angle >65° (odds ratio 6.7; 95% confidence interval 1.2-37; P = .027) were significant factors associated with insufficient ROM improvement after posterior pelvic tilt. CONCLUSIONS: Physical therapy may not be successful for patients with cam-type femoroacetabular impingement syndrome and may result in insufficient hip ROM when femoral anteversion is less than 16° and α-angle is greater than 65°. CLINICAL RELEVANCE: Patients with a prominent cam-type deformity and lower anterior femoral anteversion are at high risk of clinical failure following improvement in pelvic mobility by conservative treatment alone and are likely to benefit from surgery for cam deformity.

Hip Disorders in Bull Riders: Clinical Observations and Outcomes of Arthroscopy.

Bull riders represent a microcosm of athletes in whom severe consequences of femoroacetabular impingement may challenge the limits of arthroscopic intervention. Observations of this cohort may provide meaningful insight into the treatment of other populations. All patients undergoing hip arthroscopy are prospectively assessed with a modified Harris Hip Score. Sixteen consecutive bull riders (21 hips) with minimum 2-year follow-up are reported. The average age was 26 years, duration of symptoms was 33 months, and follow-up was 57 months. Arc of rotational hip motion averaged 31°. All had femoroacetabular impingement (17 combined and 4 cam impingements). Among the cam impingements, 1 also had dysplasia and 1 also had borderline dysplasia. Radiographic Tönnis grades were as follows: 2 Tönnis 1; 18 Tönnis 2; and 1 Tönnis 3. All had acetabular articular damage (14 Outerbridge grade 4; 6 Outerbridge grade 3; and 1 Outerbridge grade 1). Nine underwent microfracture. Four had accompanying femoral chondral lesions (3 grade 3; 1 grade 4). There were 20 labral tears (14 repaired and 6 debrided). All but 1 (95%) improved after surgery. One bilateral case underwent conversion to resurfacing arthroplasty on one side and revision arthroscopy on the other. The average improvement was 21.3 points. Thirteen (81.25%) returned to bull riding at an average of 7 months. Among the 3 who did not return, each had undergone bilateral procedures. There were no complications. Femoroacetabular impingement can be a significant problem among bull riders. Limited range of motion, grade 4 articular damage, and Tönnis 2 radiographic changes may not preclude successful arthroscopic treatment, but advanced bilateral disease may be too much even for these hardened athletes. [Orthopedics. 2024;47(2):79-82.].