Diagnostic accuracy of clinical tests for cam or pincer morphology in individuals with suspected FAI syndrome: a systematic review

Femoroacetabular impingement - What the rheumatologist needs to know

Femoroacetabular impingement (FAI) syndrome is a common cause of hip and groin pain in young individuals. FAI syndrome is a triad of signs, symptoms, and imaging findings. Necessary but not sufficient for the diagnosis of FAI syndrome is the presence of cam and/or pincer morphology of the hip. However, pathological thresholds for cam and pincer morphologies are not well-established. Management of FAI syndrome is typically through either physiotherapist-led therapy or surgical intervention. Physiotherapist-led management involves exercises aimed to optimise movement patterns of the hip and pelvis to prevent impingement from occurring, activity modification and analgesia, whereas surgical management involves arthroscopic resection of the cam/pincer morphology and treatment of concomitant soft tissue pathologies such as labral tears, cartilage lesions or ligamentum teres tears. Careful consideration of intervention is required given that FAI syndrome may predispose those affected to developing future osteoarthritis of the hip. In most clinical trials, hip arthroscopy has been found to provide greater improvement in patient-reported outcomes in the short-term compared to physiotherapy, however it is unknown whether this is sustained in the long-term or affects the future development of hip osteoarthritis.

Non-Operative Rehabilitation Principles for Use in Individuals with Acetabular Dysplasia: A North American Based Delphi Study

Background

Acetabular dysplasia (AD) is defined as a structurally deficient acetabulum and is a well-recognized cause of hip pain in young adults. While treatment of severe AD with a periacetabular osteotomy has demonstrated good long-term outcomes, a trial of non-operative management is often recommended in this population. This may be especially true in patients with milder deformities. Currently, there is a paucity of research pertaining to non-operative management of individuals with AD.

Purpose

To present expert-driven non-operative rehabilitation guidelines for use in individuals with AD.

Study Design

Delphi study.

Methods

A panel of 15 physiotherapists from North America who were identified as experts in non-operative rehabilitation of individuals with AD by a high-volume hip preservation surgeon participated in this Delphi study. Panelists were presented with 16 questions regarding evaluation and treatment principles of individuals with AD. A three-step Delphi method was utilized to establish consensus on non-operative rehabilitation principles for individuals presenting with AD.

Results

Total (100%) participation was achieved for all three survey rounds. Consensus, defined a piori as > 75%, was reached for 16/16 questions regarding evaluation principles, activity modifications, appropriate therapeutic exercise progression, return to activity/sport criteria, and indications for physician referral.

Conclusion

This North American based Delphi study presents expert-based consensus on non-operative rehabilitation principles for use in individuals with AD. Establishing guidelines for non-operative management in this population will help reduce practice variation and is the first step in stratifying individuals who would benefit from non-operative management. Future research should focus on patient-reported outcomes and rate of subsequent surgical intervention to determine the success of the guidelines reported in this study.

Level of Evidence

Level V.

Acetabular Rim Disorders: Epidemiology, Etiology, Management, and Outcomes

» Anatomic disorders of the acetabular rim are a common, correctable source of hip pain in younger patients.» Some common conditions of involving abnormal acetabular rim morphology include developmental dysplasia of the hip, pincer-type femoroacetabular impingement, acetabular protrusion, and acetabular retroversion.» Treatment option for these conditions were historically limited to open osteotomy and osteoplasty procedures; however, there is increasing use of arthroscopic intervention for these patients.» Arthroscopic intervention has demonstrated short-term success in a variety of focal acetabular rim disorders; however, further research is needed to determine the long-term outcomes of these procedures and their utility in more global pathology.

Can a Computational Model Predict the Effect of Lesion Location on Cam-type Hip Impingement?

BACKGROUND

The Warwick consensus defined femoroacetabular impingement syndrome as a motion-related clinical disorder of the hip with a triad of symptoms, clinical signs, and imaging findings representing symptomatic premature contact between the proximal femur and acetabulum. Several factors appear to cause labral and cartilage damage, including joint shape and orientation and patient activities. There is a lack of tools to predict impingement patterns in a patient across activities. Current computational modeling tools either measure pure ROM of the joint or include complexity that reduces reliability and increases time to achieve a solution.

QUESTIONS/PURPOSES

The purpose of this study was to examine the efficacy of a low computational cost approach to combining cam-type hip shape and multiple hip motions for predicting impingement. Specifically, we sought to determine (1) the potential to distinguish impingement in individual hip shapes by analyzing the difference between a cam lesion at the anterior femoral neck and one located at the superior femoral neck; (2) sensitivity to three aspects of hip alignment, namely femoral neck-shaft angle, femoral version angle, and pelvic tilt; and (3) the difference in impingement measures between the individual activities in our hip motion dataset.

METHODS

A model of the shape and alignment of a cam-type impinging hip was created and used to describe two locations of a cam lesion on the femoral head-neck junction (superior and anterior) based on joint shape information available in prior studies. Sensitivity to hip alignment was assessed by varying three aspects from a baseline (typical alignment described in prior studies), namely, femoral neck-shaft angle, femoral version, and pelvic tilt. Hip movements were selected from an existing database of 18 volunteers performing 13 activities (10 male, eight female; mean age 44 ± 19 years). A subset was selected to maximize variation in the range of joint angles and maintain a consistent number of people performing each activity, which resulted in nine people per activity, including at least three of each sex. Activities included pivoting during walking, squatting, and golf swing. All selected hip motion cases were applied to each hip shape model. For the first part of the study, the number of motion cases in which impingement was predicted was recorded. Quantitative analyses of the depth of penetration of the cam lesion into the acetabular socket and qualitative observations of impingement location were made for each lesion location (anterior and superior). In the second part of the study, in which we aimed to test the sensitivity of the findings to hip joint orientation, full analysis of both cam lesion locations was repeated for three modified joint orientations. Finally, the results from the first part of the analysis were divided by activity to understand how the composition of the activity dataset affected the results.

RESULTS

The two locations of cam lesion generated impingement in a different percentage of motion cases (anterior cam: 56% of motion cases; superior cam: 13% of motion cases) and different areas of impingement in the acetabulum, but there were qualitatively similar penetration depths (anterior cam: 6.8° ± 5.4°; superior cam: 7.9° ± 5.8°). The most substantial effects of changing the joint orientation were a lower femoral version angle for the anterior cam, which increased the percentage of motion cases generating impingement to 67%, and lower neck-shaft angle for the superior cam, which increased the percentage of motion cases generating impingement to 37%. Flexion-dominated activities (for example, squatting) only generated impingement with the anterior cam. The superior cam generated impingement during activities with high internal-external rotation of the joint (for example, the golf swing).

CONCLUSION

This work demonstrated the capability of a simple, rapid computational tool to assess impingement of a specific cam-type hip shape (under 5 minutes for more than 100 motion cases). To our knowledge, this study is the first to do so for a large set of motion cases representing a range of activities affecting the hip, and could be used in planning surgical bone removal.

CLINICAL RELEVANCE

The results of this study imply that patients with femoroacetabular impingement syndrome with cam lesions on the superior femoral head-neck junction may experience impinging during motions that are not strongly represented by current physical diagnostic tests. The use of this tool for surgical planning will require streamlined patient-specific hip shape extraction from imaging, model sensitivity testing, evaluation of the hip activity database, and validation of impingement predictions at an individual patient level.

Oxford consensus on primary cam morphology and femoroacetabular impingement syndrome: part 2-research priorities on conditions affecting the young person's hip

INTRODUCTION

Primary cam morphology is highly prevalent in many athlete populations, causing debilitating hip osteoarthritis in some. Existing research is mired in confusion partly because stakeholders have not agreed on key primary cam morphology elements or a prioritised research agenda. We aimed to inform a more rigorous, inclusive and evidence-based approach to research on primary cam morphology and its natural history by working towards agreement on a set of research priorities for conditions affecting the young person's hip.

METHODS

An international expert panel-the Young Athlete's Hip Research (YAHiR) Collaborative-rated research priority statements through an online two-round Delphi exercise and met online to explore areas of tension and dissent. Panellists ranked the prioritised research statements according to the Essential National Health Research (ENHR) ranking strategy. Reporting of results followed REPRISE (REporting guideline for PRIority SEtting of health).

RESULTS

A diverse Delphi panel (n=65, Delphi rounds 1 and 2; three ENHR strategy surveys: n=49; n=44; n=42) from 18 countries representing six stakeholder groups, prioritised and ranked 18 of 38 research priority statements. The prioritised statements outlined seven research domains: (1) best practice physiotherapy, (2) rehabilitation progression and return to sport, (3) exercise intervention and load management, (4) primary cam morphology prognosis and aetiology, (5) femoroacetabular impingement syndrome prognosis and aetiology, (6) diagnostic criteria, and (7) screening. The panel recommended areas of tension and dissent for the research community to focus on immediately.

CONCLUSION

While informing more rigorous, inclusive and evidence-based research, this consensus is a roadmap for researchers, policy-makers and funders to implement research dedicated to reducing the cost and burden of hip disease related to primary cam morphology.

Diagnostic Accuracy of Clinical Tests and Imaging Exams for Femoroacetabular Impingement: An Umbrella Review of Systematic Reviews

OBJECTIVE

To synthesize available evidence about diagnostic accuracy of clinical tests and imaging examinations for femoroacetabular impingement (FAI) syndrome.

DESIGN

Umbrella review.

SETTING

N/A.

PARTICIPANTS

N/A.

INTERVENTIONS

N/A.

MAIN OUTCOME MEASURES

Systematic reviews (SR) indexed in Embase, LIVIVO, PubMed, SCOPUS, the Cochrane Library, and Web of Science were searched in a 2-phase process. SR assessing diagnostic accuracy were considered eligible.

RESULTS

From 1520 studies, 6 SR were included, which evaluated 24 primary studies related to FAI syndrome. Of these, 5 SR assessed clinical tests, and a substantial heterogeneity was found concerning reference standards adopted across primary studies, which included arthroscopy, clinical examination (associated or not with imaging exams), intra-articular injections, and open surgery. Most clinical tests presented higher values of sensitivity compared with specificity, although evidence was considered limited because the same primary studies were often included across SR. Nonetheless, evidence around the flexion adduction internal rotation (FADIR) test was considered stronger and its use as a screening tool was consistently supported. Only one SR assessed the accuracy of imaging examinations, which adopted open surgery as the sole reference standard. Most imaging exams presented considerably high values of sensitivity, although specificity values were notably lower.

CONCLUSIONS

No robust recommendations can be provided for most clinical tests, although the FADIR test, in particular, was consistently supported as a screening tool. Moreover, although imaging examinations showed considerably high sensitivity values, evidence was considered sparse and further research is strongly recommended to validate its use as reference standards for diagnostic accuracy data.

Is Internal Rotation Measurement of the Hip Useful for Ruling in Cam or Pincer Morphology in Asymptomatic Males? A Diagnostic Accuracy Study

BACKGROUND

Cam and pincer morphologies are associated with limited internal rotation. However, the routine clinical examination for hip rotation has limited reliability. A more standardized method of measuring hip rotation might increase test-retest and interobserver reliability and might be useful as a screening test to detect different hip morphologies without the need for imaging. We developed an examination chair to standardize the measurement of internal hip rotation, which improved interobserver reliability. However, the diagnostic test accuracy for this test is unknown.

QUESTION/PURPOSE

Is a standardized method of determining internal hip rotation using an examination chair useful in detecting cam and pincer morphology with MRI as a reference standard?

METHODS

A diagnostic test accuracy study was conducted in a sample of asymptomatic males. Using an examination chair with a standardized seated position, internal rotation was measured in 1080 men aged 18 to 21 years who had been conscripted for the Swiss army. The chair prevents compensatory movement by stabilizing the pelvis and the thighs with belts. The force to produce the internal rotation was standardized with a pulley system. Previous results showed that the measurements with the examination chair are similar to clinical assessment but with higher interobserver agreement. A random sample of 430 asymptomatic males was invited to undergo hip MRI. Of those, 244 White European males responded to the invitation and had a mean age of 20 ± 0.7 years and a mean internal rotation of the hip of 33° ± 8.5°. Using MRI as the reference standard, 69% (169 of 244) had a normal hip, 24% (59 of 244) a definite cam morphology (Grades 2 and 3), 3% (8 of 244) an increased acetabular depth, and 3% (8 of 244) a combination of both. One experienced radiologist graded cam morphology as follows: 0 = normal, 1 = mild, 2 = moderate, and 3 = severe. Pincer morphology was defined by increased acetabular depth (≤ 3 mm distance between the center of the femoral neck and the line connecting the anterior and posterior acetabular rims). The intraobserver agreement was substantial (weighted κ of 0.65). A receiver operating characteristic (ROC) curve was fitted, and sensitivity, specificity, and likelihood ratios were estimated for different internal rotation cutoffs.

RESULTS

For cam morphology, the area under the ROC curve was 0.75 (95% CI 0.67 to 0.82). Internal hip rotation of less than 20° yielded a positive likelihood ratio of 9.57 (sensitivity 0.13, specificity 0.99), and a value of 40° or more resulted in a negative likelihood ratio of 0.36 (sensitivity 0.93, specificity 0.20). The area under the curve for detecting the combination of cam and pincer morphologies was 0.87 (95% CI 0.74 to 1.0). A cutoff of 20° yielded a positive likelihood ratio of 9.03 (sensitivity 0.33, specificity 0.96).

CONCLUSION

This examination chair showed moderate-to-good diagnostic value to rule in hip cam morphology in White European males. However, at the extremes of the 95% confidence intervals, diagnostic performance would be poor. Nonetheless, we believe this test can contribute to identifying cam morphologies, and we hope that future, larger studies-ideally in more diverse patient populations-will seek to validate this to arrive at more precise estimates of the diagnostic performance of this test.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Can a Hip Brace Improve Short-Term Hip-Related Quality of Life for People With Femoroacetabular Impingement and Acetabular Labral Tears: An Exploratory Randomized Trial

OBJECTIVES

To examine whether a hip brace can improve hip health quality-of-life (QoL) and is well-tolerated in people with femoroacetabular impingement syndrome (FAIS) or symptomatic labral tears after 6 weeks of wear.

DESIGN

Parallel, two-arm, exploratory randomized trial.

SETTING

Hospital and private clinics of orthopaedic surgeons.

PARTICIPANTS

Individuals >18 years with FAIS or labral tears.

INTERVENTIONS

Usual conservative care versus usual conservative care plus a hip brace.

MAIN OUTCOMES

Patient-reported outcomes were assessed with the International Hip Outcome Tool (iHOT-33), and Copenhagen Hip and Groin Outcome Scores (HAGOS). Brace acceptability was measured using the Quebec User Evaluation of Satisfaction with Assistive Technology survey. Independent t-tests assessed between-group differences.

RESULTS

Thirty-eight participants were recruited, 19 each group, 60% women, mean age 39.3 ± 11.8 years, body mass index 25.3 ± 4.4 kg/m2, iHOT-33 36.6 ± 24.8. Three participants dropped out (one usual care, 2 braced). The mean between-group difference for iHOT-33 was 19.4 (95% confidence interval [CI] 1.68-37.06, P = 0.03) favoring the brace. There were improvements in most HAGOS subscale scores favoring the brace. Issues with brace tolerability for some participants were perceived comfort and effectiveness. Three brace-related adverse events were reported.

CONCLUSION

Between-group differences favored the braced group for hip health QoL, pain, symptoms, and function. Although these were promising results, the CIs for the estimates were wide, the small sample size likely a contributing factor. Our results suggest that further investigation of the brace is warranted, we calculated sample sizes and made recommendations for the design of a future trial.

Femoroacetabular impingement syndrome and labral injuries: grading the evidence on diagnosis and non-operative treatment-a statement paper commissioned by the Danish Society of Sports Physical Therapy (DSSF)

This statement summarises and appraises the evidence on diagnostic tests and clinical information, and non-operative treatment of femoroacetabular impingement (FAI) syndrome and labral injuries. We included studies based on the highest available level of evidence as judged by study design. We evaluated the certainty of evidence using the Grading of Recommendations Assessment Development and Evaluation framework. We found 29 studies reporting 23 clinical tests and 14 different forms of clinical information, respectively. Restricted internal hip rotation in 0° hip flexion with or without pain was best to rule in FAI syndrome (low diagnostic effectiveness; low quality of evidence; interpretation of evidence: may increase post-test probability slightly), whereas no pain in Flexion Adduction Internal Rotation test or no restricted range of motion in Flexion Abduction External Rotation test compared with the unaffected side were best to rule out (very low to high diagnostic effectiveness; very low to moderate quality of evidence; interpretation of evidence: very uncertain, but may reduce post-test probability slightly). No forms of clinical information were found useful for diagnosis. For treatment of FAI syndrome, 14 randomised controlled trials were found. Prescribed physiotherapy, consisting of hip strengthening, hip joint manual therapy techniques, functional activity-specific retraining and education showed a small to medium effect size compared with a combination of passive modalities, stretching and advice (very low to low quality of evidence; interpretation of evidence: very uncertain, but may slightly improve outcomes). Prescribed physiotherapy was, however, inferior to hip arthroscopy (small effect size; moderate quality of evidence; interpretation of evidence: hip arthroscopy probably increases outcome slightly). For both domains, the overall quality of evidence ranged from very low to moderate indicating that future research on diagnosis and treatment may alter the conclusions from this review.

Insurance Coverage Criteria for Femoroacetabular Impingement Surgery: Are They Responding to Improving Evidence?

BACKGROUND

With the rapidly growing body of FAI literature in the last decade, improved evidence exists to support FAI surgery. However, it remains unclear how well third-party insurance company's FAI policies have adapted over time to improved evidence. The purpose of this study was (1) to compare the 2020 FAI surgery criteria of four major insurance companies utilizing a multi-center cohort of FAI patients undergoing surgery to identify rates and causes of ineligibility, and (2) to compare the rates of approval based on changes in policy from 2012 to 2020.

METHODS

Four major insurance companies' coverage policies with specific criteria for the surgical treatment of FAI were applied to this population at two time points (2012 and 2020). The policies listed various combinations of age, symptom duration, radiographic signs of FAI, radiographic signs of osteoarthritis, and physical exam findings. A prospective, multi-center cohort of 712 patients (including 45.5% males and 54.5% females with a mean age of 28.7 years) undergoing surgical treatment of FAI was utilized for analysis of insurance policies.

RESULTS

Based on 2020 FAI policies across 4 insurers, 22.5% (range 18.4-28.4%) of FAI patients would be deemed ineligible. In 2012, the average percent exclusion of the four companies was 23.7%. The most likely reason to be excluded was either failure to meet imaging criteria (alpha angle >50° or positive cross-over sign) [13%, n=94]) or the absence of an impingement sign (9%, n=65). Other causes of exclusion were <6-month symptom duration (6%, n=44), age <15 years (4%, n=28), or skeletally immaturity (3%, n=23).

CONCLUSION

Our study shows that despite a six-year span of growing literature and updated policies, nearly 1 in 5 patients diagnosed with FAI would still potentially be denied coverage. This highlights a continued divide between surgeons and insurance companies. There is a major need for improved consensus regarding the diagnosis of FAI and appropriate indications for surgical intervention.Level of Evidence: IV.

Less hip range of motion is associated with a greater alpha angle in people with longstanding hip and groin pain

PURPOSE

A higher alpha angle has been proposed to correlate with lower hip range of motion, but the association in people with longstanding hip and groin pain is currently unclear. The aims were to: (1) assess the association between range of motion and alpha angle in patients with longstanding hip and groin pain; (2) examine if a cut-off value in range of motion variables could identify patients with an alpha angle above or below 60°.

METHODS

Seventy-two participants were consecutively recruited from an orthopaedic department after referral for hip- and groin-related pain. Passive hip range of motion was measured in flexion, internal rotation with 90° hip flexion, internal rotation in neutral hip position, external rotation with 90° hip flexion, and abduction. The alpha angle was calculated from a frog-leg lateral radiograph. Linear regression examined the association between range of motion and alpha angle, and an ROC-curve analysis was performed to identify the sensitivity and specificity of range of motion cut-offs.

RESULTS

Lower range of motion in internal rotation in flexion, external rotation, and abduction were associated with higher alpha angle. Internal rotation of 27° or less displayed good sensitivity (81%) and specificity (85%) to detect an alpha angle above 60°, while a cut-off of 41° in external rotation and 27° in abduction showed a sensitivity of 72% and specificity of 50% and 60%, respectively.

CONCLUSION

Less internal rotation in flexion, external rotation, and abduction are associated with a greater alpha angle in a cohort of people with longstanding hip and groin pain. A cut-off of 27° in internal rotation has good sensitivity and specificity to identify people with an alpha angle above or below 60° and have the potential to be used in the clinical setting to identify patients that require further imaging, or that are unlikely to have cam morphology.

LEVEL OF EVIDENCE

II.

Historical analysis of the diagnosis and management of femoroacetabular impingement prior to the year 2000: a systematic review

 

This systematic review aims to assess the diagnosis, indications and treatment of femoroacetabular impingement (FAI) prior to the year 2000 and to determine if historical concepts remain applicable today. PUBMED, MEDLINE and EMBASE were searched for literature evaluating the diagnosis/treatment of FAI prior to 2000. Cadaver/non-human, non-English and review studies were excluded. Quality assessment was performed using the Methodological Index for Non-Randomized Studies. Nine studies comprising 307 patients [315 hips; mean age of 32.6 ± 2.4 years (range, 12-58)] were included. Patients reported groin pain. Magnetic resonance arthrography (MRA; n = 76) and the anterior impingement test (AIT) (n = 88) were used to diagnose impingement. Surgical dislocation with a trochanteric flip osteotomy (n = 237) and Bernese periacetabular osteotomy (n = 40) were common treatments. Pain and range of motion improved for patients. Overall complication rate was 35% (n = 99), with heterotopic ossification (n = 79) most commonly reported. Prior to 2000, there was low quantity and quality of research on the diagnosis/management of FAI. Diagnostic evaluation was primarily through clinical examination (i.e. groin pain and AIT). MRA was occasionally used to detect labral degeneration; however, utilization of computed tomography (CT) and diagnostic injections were not reported. Surgical dislocation and osteotomies of the acetabulum yielded desirable short-term clinical outcomes with a moderate complication rate. No study reported using arthroscopy for FAI management prior to 2000. Clinicians today can learn from historical principles (i.e. clinical diagnosis of FAI, management with surgical correction of femoral head-neck offset) while applying novel techniques (i.e. CT, injections, arthroscopic surgical techniques and rehabilitation) to improve patient outcomes.

Level of Evidence

IV (systematic review of III and IV evidence).

Diagnostic accuracy of tests for type 2 diabetes and prediabetes: A systematic review and meta-analysis

AIM

This systematic review aimed to ascertain the diagnostic accuracy (sensitivity and specificity) of screening tests for early detection of type 2 diabetes and prediabetes in previously undiagnosed adults.

METHODS

This systematic review included published studies that included one or more index tests (random and fasting tests, HbA1c) for glucose detection, with 75-gram Oral Glucose Tolerance Test (or 2-hour post load glucose) as a reference standard (PROSPERO ID CRD42018102477). Seven databases were searched electronically (from their inception up to March 9, 2020) accompanied with bibliographic and website searches. Records were manually screened and full text were selected based on inclusion and exclusion criteria. Subsequently, data extraction was done using standardized form and quality assessment of studies using QUADAS-2 tool. Meta-analysis was done using bivariate model using Stata 14.0. Optimal cut offs in terms of sensitivity and specificity for the tests were analysed using R software.

RESULTS

Of 7,151 records assessed by title and abstract, a total of 37 peer reviewed articles were included in this systematic review. The pooled sensitivity, specificity, positive (LR+) and negative likelihood ratio (LR-) for diagnosing diabetes with HbA1c (6.5%; venous sample; n = 17 studies) were 50% (95% CI: 42-59%), 97.3% (95% CI: 95.3-98.4), 18.32 (95% CI: 11.06-30.53) and 0.51 (95% CI: 0.43-0.60), respectively. However, the optimal cut-off for diagnosing diabetes in previously undiagnosed adults with HbA1c was estimated as 6.03% with pooled sensitivity of 73.9% (95% CI: 68-79.1%) and specificity of 87.2% (95% CI: 82-91%). The optimal cut-off for Fasting Plasma Glucose (FPG) was estimated as 104 milligram/dL (mg/dL) with a sensitivity of 82.3% (95% CI: 74.6-88.1%) and specificity of 89.4% (95% CI: 85.2-92.5%).

CONCLUSION

Our findings suggest that at present recommended threshold of 6.5%, HbA1c is more specific and less sensitive in diagnosing the newly detected diabetes in undiagnosed population from community settings. Lowering of thresholds for HbA1c and FPG to 6.03% and 104 mg/dL for early detection in previously undiagnosed persons for screening purposes may be considered.