Clinical Presentation Differences Among Four Subtypes of Femoroacetabular Impingement: A Case-Control Study

OBJECTIVE

The aims of this study were to assess the psychological, functional, and physical differences between patients with femoroacetabular impingement (FAI) syndrome and individuals who were asymptomatic (controls) to analyze clinical differences among 4 subtypes of FAI (cam type, cam type with labral tear, pincer type, and pincer type with labral tear), to calculate the correlations among the variables described, and to identify risk factors contributing to the hip function variance.

METHODS

A case-control study was conducted at a hospital rehabilitation unit with a cohort of individuals who were asymptomatic (controls) and a cohort of patients with FAI. Sociodemographic characteristics, pain intensity, psychological health status, hip range of motion (RoM), hip isometric strength, and hip function were assessed.

RESULTS

A total of 69 controls and 69 patients with FAI were analyzed. Although sociodemographic characteristics were comparable between samples, poorer hip RoM, strength, and psychological health were found for the cases. FAI subtypes showed no significant pain intensity, psychological health, or RoM differences (except for hip adduction), but hip strength differed among FAI subtypes. Multiple significant correlations between psychological health, pain intensity, RoM, strength, and hip function were found. The variance values of the International Hip Outcome Tool, Hip Outcome Score (HOS) for daily living activities, and HOS for sports activities were partially explained (47.6%, 36.0%, and 21.6%, respectively) on the basis of kinesiophobia, hip strength, self-efficacy, and anxiety.

CONCLUSION

Patients with FAI showed poorer psychological health, hip RoM, and strength than individuals who were asymptomatic and had similar sociodemographic characteristics. FAI subtype influenced the patients' clinical presentations. Hip strength, kinesiophobia, anxiety, and self-efficacy should be targeted for improving hip function, as they have been demonstrated to be important contributors to hip disability.

IMPACT

This study demonstrated that pain catastrophizing, hip strength, and hip adduction differed among FAI subtypes. However, hip function and pain intensity were comparable between FAI subtypes.

Comparison of Joint Mobilization and Movement Pattern Training for Patients With Hip-Related Groin Pain: A Pilot Randomized Clinical Trial

OBJECTIVE

The objective of this study was to assess the feasibility of completing a randomized clinical trial (RCT) and examine the preliminary effects of 2 interventions for hip-related groin pain (HRGP).

METHODS

In this pilot RCT, patients with HRGP, who were 18 to 40 years old, were randomized (1:1 ratio) to a joint mobilization (JtMob) group or a movement pattern training (MoveTrain) group. Both treatments included 10 supervised sessions and a home exercise program. The goal of JtMob was to reduce pain and improve mobility through peripherally and centrally mediated pain mechanisms. The key element was physical therapist-provided JtMob. The goal of MoveTrain was to reduce hip joint stresses by optimizing the biomechanics of patient-specific tasks. The key element was task-specific instruction to correct abnormal movement patterns displayed during tasks. Primary outcomes were related to future trial feasibility. The primary effectiveness outcome was the Hip Disability and Osteoarthritis Outcome Score. Examiners were blinded to group; patients and treatment providers were not. Data collected at baseline and immediately after treatment were analyzed with analysis of covariance using a generalized linear model in which change was the dependent variable and baseline was the covariate. The study was modified due to the coronavirus disease 2019 (COVID-19) pandemic.

RESULTS

The COVID-19 pandemic affected participation; 127 patients were screened, 33 were randomized (18 to the JtMob group and 15 to the MoveTrain group), and 29 (88%) provided posttreatment data. Treatment session adherence was 85%, and home exercise program component adherence ranged from 71 to 86%. Both groups demonstrated significant mean within-group improvements of ≥5 points on Hip Disability and Osteoarthritis Outcome Score scales. There were no between-group differences in effectiveness outcomes.

CONCLUSIONS

A large RCT to assess the effects of JtMob and MoveTrain for patients with HRGP may be feasible. Preliminary findings suggested that JtMob or MoveTrain may result in improvements in patient-reported pain and activity limitations.

IMPACT

The COVID-19 pandemic interfered with participation, but a randomized controlled trial may be feasible. Modification may be needed if the trial is completed during future pandemics.

Relationship between the Depth of Acetabuloplasty and Outcomes of Hip Arthroscopy in Patients with Global Pincer Femoroacetabular Impingement: Study with a Minimum Follow-Up Period of 2 Years

OBJECTIVE

There has been no definite consensus on the ideal depth of acetabuloplasty, especially in cases of global pincer femoroacetabular impingement (FAI). This study aims to determine whether the depth of acetabuloplasty influences postoperative outcomes in cases of global pincer FAI.

METHODS

Data were retrospectively collected from patients with global pincer FAI who underwent hip arthroscopy with a minimum follow-up period of 2 years from May 2014 to December 2018. Patients with global pincer FAI were subdivided into low or high resection depth groups based on whether the intraoperative acetabular rim was resected by more than 3 mm. Radiographic measurements; arthroscopic procedures; preoperative and postoperative PROs were recorded. Achievement of MCID and PASS was compared for the VAS, mHHS, HOS-ADL, and iHOT-12. A paired Student t-test was used to evaluate the significance of preoperative and postoperative PROs and two-tailed unpaired Student t-test was used to compare demographic data and PROs between different groups. MCID and PASS were evaluated using the chi-square test or the Fisher's exact test.

RESULTS

A total of 41 hips with global pincer FAI (15 and 26 patients in low or high resection depth groups, respectively) were included in this study. Both groups showed significant postoperative improvements in the scores of all PROs (p < 0.001). Compared to the low resection depth group, the high resection depth group had a lower degree of improvement through hip arthroscopy, which manifested as lower postoperative mHHS scores (94.29 vs. 85.08, p = 0.006), higher VAS scores (0.93 vs. 2.54, p = 0.002), and lower improvements in VAS (-5.00 vs. -3.35, p = 0.028), HOS-ADL (34.99 vs. 23.90, p = 0.017) and iHOT-12 (39.89 vs. 29.27, p = 0.036). Patients in high resection depth group were less likely to achieve the MCID for the VAS score compared to low resection depth group in significant (73.3 vs. 26.9%, p = 0.004).

CONCLUSIONS

For patients with global pincer, the outcomes in high resection depth group were slightly worse than the the low resection depth group. It is indicated that excessive resection of the acetabular rim during the procedure should be avoided.

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

BACKGROUND

Acetabular 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 QUESTION

Does squat and gait biomechanics change following an 8-week targeted exercise program in individuals with symptomatic acetabular retroversion and FAIS?

METHODS

This 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.

RESULTS

Nineteen 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.

SIGNIFICANCE

Following 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.

Labral tears in hip dysplasia and femoroacetabular impingement: a systematic review

INTRODUCTION

Hip dysplasia and femoroacetabular impingement are pathologies whose impact on the function and survival of the hip joint is no longer debated. Labral tears may be present and impact the prognosis of the causal pathology. Labral tear management lacks consensus and still raises several questions, thus we conducted a systematic analysis to clarify: 1) What is its prevalence in hip dysplasia and femoroacetabular impingement? 2) Does it modify the symptomatology of the causal pathology? 3) Is its repair better than resection or abstention?

MATERIAL AND METHOD

A systematic literature review was carried out following the PRISMA guidelines, using the Medline and Embase databases and including all articles in French or English, written until June 2022 referring to labral tears in hip dysplasia and femoroacetabular impingement. The articles were analyzed by 2 surgeons in order to select them according to a predefined algorithm. 1) Articles were selected by title from the search results. 2) A selection based on the abstract was then made. 3) A final selection was made upon complete reading. 4) In the event of a discrepancy during the selection, a third co-author was contacted for a final decision. 5) Data extraction was then carried out by the two readers using a preformatted sheet.

RESULTS

Of the 1177 articles identified, 43 articles were kept for the final analysis. The prevalence of labral tears was on average 78.80±4.7% [17 to 100%] in dysplasia and 93.8±16.8% [33% to 100%] in impingement. The review did not reveal any symptomatology specific to the labral tear. In dysplasia, 5 comparative studies were analyzed. A single study on shelf arthroplasties demonstrated the negative impact of a labral tear in the event of resection on survival compared to no tear (83% versus 15.2% (p = 0.048)). Regarding impingements, 8 comparative studies were analyzed. At 7 years of follow-up, only one study found a significant and clinically relevant functional gain in terms of MCID (minimal clinically important difference) for labral repair compared to debridement on the mHHS score (p = 0.008), SF-12 score (p = 0.012), and pain scale (p = 0.002). One study showed superiority of repair over labral debridement in terms of 10-year survival (78% 95% CI [64-92%] vs 46% 95% CI [26-66%] (p = 0.009)).

DISCUSSION

The literature analysis was heterogeneous with a few comparative studies and predominantly short periods of follow-up. Understanding labral pathology and its impact requires differentiating between the different tear categories and proposing treatment to restore or preserve the biomechanical properties of the joint.

LEVEL OF EVIDENCE

IV, Systematic Review of Level 1-4 Evidence.

Effect of modeling femoral version and head-neck offset correction on computed contact mechanics in dysplastic hips treated with periacetabular osteotomy

While correction of dysplastic acetabular deformity has been a focus of both clinical treatment and research, concurrent femoral deformities have only more recently received serious attention. The purpose of this study was to determine how including abnormalities in femoral head-neck offset and femoral version alter computationally derived contact stresses in patients with combined dysplasia and femoroacetabular impingement (FAI). Hip models with patient-specific bony anatomy were created from preoperative and postoperative CT scans of 20 hips treated with periacetabular osteotomy and femoral osteochondroplasty. To simulate performing only a PAO, a third model was created combining each patient's postoperative pelvis and preoperative femur geometry. These three models were initialized with the femur in two starting orientations: (1) standardized template orientation, and (2) using patient-specific anatomic landmarks. Hip contact stresses were computed in all 6 model sets during an average dysplastic gait cycle, an average FAI gait cycle, and an average stand-to-sit activity using discrete element analysis. No significant differences in peak contact stress (p = 0.190 to 1), mean contact stress (p = 0.273 to 1), or mean contact area (p = 0.050 to 1) were identified during any loading activity based on femoral alignment technique or inclusion of femoral osteochondroplasty. These findings suggest that presence of abnormal femoral version and/or head-neck offset deformities are not themselves predominant factors in intra-articular contact mechanics during gait and stand-to-sit activities. Inclusion of modified movement patterns caused by these femoral deformities may be necessary for models to adequately capture the mechanical effects of these clinically recognized risk factors for negative outcomes.

[Epidemiology, prevention and early detection of femoroacetabular impingement syndrome (FAIS)]

During the last two decades femoroacetabular impingement syndrome (FAIS) has gained importance and is one of the main causes of hip pain in young adults. FAIS is a motion-related clinical pathology of the hip that represents symptomatic contact between the proximal femur and the acetabulum. Symptoms, clinical signs, and imaging findings must be present to diagnose FAIS. Especially the development of the cam-FAIS seems to be associated with an overuse of the growth plate during adolescence. Here an approach may be found for the prevention of the development of FAIS. Sufficient evidence through high-quality long-term results is yet lacking.

Open MRI assessment of anterior femoroacetabular clearance in active and passive impingement-provoking postures

Aims

Cam and pincer morphologies are potential precursors to hip osteoarthritis and important contributors to non-arthritic hip pain. However, only some hips with these pathomorphologies develop symptoms and joint degeneration, and it is not clear why. Anterior impingement between the femoral head-neck contour and acetabular rim in positions of hip flexion combined with rotation is a proposed pathomechanism in these hips, but this has not been studied in active postures. Our aim was to assess the anterior impingement pathomechanism in both active and passive postures with high hip flexion that are thought to provoke impingement.

Methods

We recruited nine participants with cam and/or pincer morphologies and with pain, 13 participants with cam and/or pincer morphologies and without pain, and 11 controls from a population-based cohort. We scanned hips in active squatting and passive sitting flexion, adduction, and internal rotation using open MRI and quantified anterior femoroacetabular clearance using the β angle.

Results

In squatting, we found significantly decreased anterior femoroacetabular clearance in painful hips with cam and/or pincer morphologies (mean -11.3° (SD 19.2°)) compared to pain-free hips with cam and/or pincer morphologies (mean 8.5° (SD 14.6°); p = 0.022) and controls (mean 18.6° (SD 8.5°); p < 0.001). In sitting flexion, adduction, and internal rotation, we found significantly decreased anterior clearance in both painful (mean -15.2° (SD 15.3°); p = 0.002) and painfree hips (mean -4.7° (SD 13°); p = 0.010) with cam and/pincer morphologies compared to the controls (mean 7.1° (SD 5.9°)).

Conclusion

Our results support the anterior femoroacetabular impingement pathomechanism in hips with cam and/or pincer morphologies and highlight the effect of posture on this pathomechanism.

Cite this article: Bone Jt Open 2021;2(11):988–996.

FUNCTIONAL OUTCOMES OF ARTHROSCOPIC TREATMENT IN 230 FEMOROACETABULAR IMPINGEMENT CASES

Objective:

To analyze the functional outcomes after arthroscopic treatment of femoroacetabular impingement (FAI).

Methods:

194 patients (131 males and 63 females), with a mean age of 39 (15-68) years old for men and 43 (16-58) years old for women. The average follow-up was 17 months (2 to 71). 103 patients presented Cam-type FAI, 102 mixed and 25 Pincer. “Unilateral” arthroscopy was performed in 161 cases, “Bilateral” (only once each side) in 46 cases and, “Multiple” (more than one procedure on the same hip) in 23. The female sex was prevalent in the Pincer type FAI (76%), while males were prevalent in Mixed and Cam type, 74.5% and 72.8%, respectively.

Results:

The mean HHSpre score was 63.7 and 87.1 for HHSpost, i.e. 73.11%. Differences appeared between “mixed” and “unilateral” groups. The complications percentage in this series was 18.7% and 7% progressed to total hip arthroplasty.

Conclusion:

The arthroscopic FAI treatment improved the postoperative clinical scores of these patients, especially in cases of mixed-type FAI, which presented a higher improvement rate. Insufficient femoral osteoplasty was the main cause for surgical re-intervention, particularly in the initial cases of this series. Level of Evidence II, Retrospective study.

Gender-Specific Sexual Activity After Hip Arthroscopy for Femoroacetabular Impingement Syndrome: Position Matters

BACKGROUND

There is limited evidence on the safety of return to sexual activity after hip arthroscopy.

AIM

To determine the positional safety of sexual activity after hip arthroscopy relative to hip instability and/or impingement risk.

STUDY DESIGN

This study is an observational study.

METHODS

12 common sexual positions were identified based on previous research. Gender-specific hip motion was then assessed for the possibility of postarthroscopic hip instability (due to disruption of iliofemoral ligament [interportal capsulotomy] repair) and/or impingement (labral or capsular compressive stress with disrupted repair) for all 12 positions (both right and left hips; 15 unique male and 14 unique female positions). Instability risk was defined as greater than 0° hip extension, greater than 30° external rotation (ER), or greater than 30° abduction. Impingement risk was defined as greater than 90° hip flexion, greater than 10° internal rotation, and greater than 10° adduction.

OUTCOMES

A majority of both male and female sexual positions caused either instability or impingement, with only 4 positions in women and 4 positions in men deemed "safe" by avoiding excessive hip motion.

RESULTS

Return to sexual activity after hip arthroscopy may cause instability in 10/15 of male positions and 5/14 female positions. Most male positions (6/10) were at risk for instability because of excessive ER. 2 positions were unstable because of a combination of ER and extension, one was due to extension, and one abduction. In female instability positions, all 5 were unstable because of excessive abduction. Impingement may be observed in 5 of 15 male positions and 6 of 14 female positions. In male impingement positions, all were due to excessive adduction. 4 female positions risked impingement due to excessive flexion and 2 positions due to internal rotation.

CLINICAL IMPLICATIONS

This study demonstrates risks that should be considered when counseling patients preoperatively and postoperatively regarding sexual activity.

STRENGTHS & LIMITATIONS

This study closely models a hip preservation patient population by using 2 young and otherwise healthy individuals. The most significant limitation of this investigation was its basis with only 2 young healthy volunteers (one male, one female) in a single motion capture session using surface-based spherical retroreflective markers from a previous investigation.

CONCLUSION

After hip arthroscopy, patients need to be made aware of the possibility of hip instability (10 of 15 men; 5 of 14 women) and impingement (5 of 15 men; 6 of 14 women) due to excessive hip motion that may compromise their outcome. Morehouse H, Sochacki KR, Nho SJ, et al. Gender-Specific Sexual Activity After Hip Arthroscopy for Femoroacetabular Impingement Syndrome: Position Matters. J Sex Med 2020;17:658-664.

Patients with severe slipped capital femoral epiphysis treated by the modified Dunn procedure have low rates of avascular necrosis, good outcomes, and little osteoarthritis at long-term follow-up

AIMS

The modified Dunn procedure has the potential to restore the anatomy in hips with severe slipped capital femoral epiphyses (SCFE). However, there is a risk of developing avascular necrosis of the femoral head (AVN). In this paper, we report on clinical outcome, radiological outcome, AVN rate and complications, and the cumulative survivorship at long-term follow-up in patients undergoing the modified Dunn procedure for severe SCFE.

PATIENTS AND METHODS

We performed a retrospective analysis involving 46 hips in 46 patients treated with a modified Dunn procedure for severe SCFE (slip angle > 60°) between 1999 and 2016. At nine-year-follow-up, 40 hips were available for clinical and radiological examination. Mean preoperative age was 13 years, and 14 hips (30%) presented with unstable slips. Mean preoperative slip angle was 64°. Kaplan-Meier survivorship was calculated.

RESULTS

At the latest follow-up, the mean Merle d'Aubigné and Postel score was 17 points (14 to 18), mean modified Harris Hip Score was 94 points (66 to 100), and mean Hip Disability and Osteoarthritis Outcome Score was 91 points (67 to 100). Postoperative slip angle was 7° (1° to 16°). One hip (2%) had progression of osteoarthritis (OA). Two hips (5%) developed AVN of the femoral head and required further surgery. Three other hips (7%) underwent implant revision due to screw breakage or change of wires. Cumulative survivorship was 86% at ten-year follow-up.

CONCLUSION

The modified Dunn procedure for severe SCFE resulted in a low rate of AVN, low risk of progression to OA, and high functional scores at long-term follow-up. The slip deformities were mainly corrected but secondary impingement deformities can develop in some hips and may require further surgical treatment. Cite this article: Bone Joint J 2019;101-B:403-414.

Causes of Chronic Hip Pain Undiagnosed or Misdiagnosed by Primary Physicians in Young Adult Patients: a Retrospective Descriptive Study

BACKGROUND

Hip pain is a common musculoskeletal complaint in general practice. Although comprehensive diagnostic approach on hip pain is mandatory for adequate treatment, un- or mis-diagnosis is not rare in primary care. The aim of this study was to analyze descriptively un- or mis-diagnosed hip pain cases referred from primary care to a tertiary hospital, especially in young adults ≤ 50 years old.

METHODS

We retrospectively analyzed a consecutive cohort of 150 patients (≤ 50 years old) with chronic hip pain (≥ 6 weeks), which was not diagnosed or misdiagnosed based on the information provided on the referral form.

RESULTS

Overall an average 32 cases/month were referred due to hip pain without a diagnosis or with an incorrect diagnosis. Among them, 150 patients were enrolled in this study and 146 (97.3%) could be allocated to a specific disease by using data from routine clinical practice. Four common final diagnoses were femoroacetabular impingement (FAI) syndrome (55.3%), hip dysplasia (HD, 13.3%), referred pain from the lumbar spine (9.3%), and spondyloarthritis (SpA, 7.3%). In patients with FAI syndrome, 37 (44.0%) had pincer-type FAI and 33 (39.8%) had combined-type. Although the pain site or gender was not tightly clustered, the distribution of final diagnosis was significantly different according to hip pain location or gender. Especially, SpA or HD was not observed in younger women subgroup or elder men subgroup, respectively, when stratified by the mean age of participants.

CONCLUSION

Most (> 80%) young patients with hip pain, a difficult issue to diagnosis for many primary physicians, had FAI syndrome, HD, spine lesions, and SpA. This study could give a chance to feedback information about cases with un- or mis-diagnosed hip pain, and it suggests that primary physicians need to be familiar with the diagnostic approach for these 4 diseases.

Descriptive Epidemiology of Patients Undergoing Total Hip Arthroplasty in Korea with Focus on Incidence of Femoroacetabular Impingement: Single Center Study

We analyzed the causes leading to total hip arthroplasty (THA), aimed to clarify the incidence of femoroacetabular impingement (FAI) among the causes, and compared the incidence in Korea with those in other countries. From January 2000 to December 2014, 1,206 hips of 818 patients who underwent primary THA at our institute were reviewed retrospectively in terms of radiographs and electronic charts. The radiographs and radiographic parameters were reviewed and measured by 2 of the authors, who are orthopedic surgeons. Patients were categorized in terms of the causes leading to THA as primary osteoarthritis (OA), rheumatoid arthritis (RA), posttraumatic arthritis, post infectious arthritis, avascular necrosis (AVN) of the femoral head, fracture of the femoral head or neck, ankylosing spondylitis (AS), developmental dysplasia of the hip (DDH), Legg-Calvé-Perthes disease (LCPD), FAI, and others. There were 32 patients (3.91%) in the primary OA group, 41 (5.01%) in the RA group, 84 (10.27%) in the posttraumatic arthritis group, 39 (4.77%) in the post infectious arthritis group, 365 (44.62%) in the AVN group, 39 (4.77%) in the fracture group, 21 (2.57%) in the AS group, 52 (6.36%) in the DDH group, 71 (8.68%) in the LCPD group, 52 (6.36%) in the FAI group, and 22 (2.69%) in the 'other' group. The causes leading to THA in Korea differ from those in Western countries. FAI could be causes of severe secondary OA that requires THA in Korea, therefore symptomatic FAI should not be neglected.

Posterior, Lateral, and Anterior Hip Pain Due to Musculoskeletal Origin: A Narrative Literature Review of History, Physical Examination, and Diagnostic Imaging

OBJECTIVE

The purpose of this study was to present a narrative review of the literature of musculoskeletal causes of adult hip pain, with special attention to history, physical examination, and diagnostic imaging.

METHODS

A narrative review of the English medical literature was performed by using the search terms "hip pain" AND "anterior," "lateral," and "posterior." Additionally, specific entities of hip pain or pain referral sources to the hip were searched for. We used the PubMed search engine through January 15, 2016.

RESULTS

Musculoskeletal sources of adult hip pain can be divided into posterior, lateral, and anterior categories. For posterior hip pain, select considerations include lumbar spine and femoroacetabular joint referral, sacroiliac joint pathology, piriformis syndrome, and proximal hamstring tendinopathy. Gluteal tendinopathy and iliotibial band thickening are the most common causes of lateral hip pain. Anterior hip pain is further divided into causes that are intra-articular (ie, labral tear, osteoarthritis, osteonecrosis) and extra-articular (ie, snapping hip and inguinal disruption [athletic pubalgia]). Entrapment neuropathies and myofascial pain should also be considered in each compartment. A limited number of historical features and physical examination tests for evaluation of adult hip pain are supported by the literature and are discussed in this article. Depending on the clinical differential, the gamut of diagnostic imaging modalities recommended for accurate diagnosis include plain film radiography, computed tomography, magnetic resonance imaging, skeletal scintigraphy, and ultrasonography.

CONCLUSIONS

The evaluation of adult hip pain is challenging. Clinicians should consider posterior, lateral, and anterior sources of pain while keeping in mind that these may overlap.

Intra-Articular Injections in Patients with Femoroacetabular Impingement: a Prospective, Randomized, Double-blind, Cross-over Study

We evaluated and compared the effectiveness of intra-articular injection of hip joint using hyaluronic acid and steroid in patients with femoroacetabular impingement (FAI). Thirty patients with FAI clinically and radiologically were enrolled and underwent hip injection using steroid (TA) or hyaluronic acid (HA) at 0-weeks with cross-over injection at 2-weeks in patients without clinical response of decrease of pain intensity less than 2-point. Patients were followed up to 12-weeks for pain intensity (Numeric rating scale, NRS: 0-10), hip disability score (HOOS), oral medication and adverse events. In 17 patients without cross-over, HOOS at 2-weeks was improved significantly in patients with HA injection (mean increase of HOOS = 13.8 with HA vs. -2.2 with TA, P = 0.031) without difference of NRS (P = 0.943). In 13 patients with cross-over, NRS was significantly improved at 2-weeks with first TA injection (mean decrease of NRS= 1.7 with first TA vs. 0.3 with first HA, P = 0.036), without difference of HOOS (P = 0.431). At 4-weeks, NRS and HOOS were significantly different according to injection drugs (NRS: 0.9 with TA first and HA later vs. 2.7 with HA first and TA later, P = 0.001; mean increase of HOOS: 5.3 with TA first and HA later vs. 10.2 with HA first and TA later, P = 0.032). Intra-articular hip injection may be effective in FAI, with faster effect of pain improvement by TA and more delayed effect of function improvement by HA.