Labral tears, extra-articular injuries, and hip arthroscopy in the athlete

Radial Planes in Hip Magnetic Resonance Imaging: Techniques, Applications, and Perspectives

The hip cartilage and labrum, as the main targets of femoroacetabular impingement, sports-related or traumatic damage, as well as congenital and developmental abnormalities, have attracted increasing attention with the development of magnetic resonance imaging (MRI) and hip arthroscopy. MRI is a commonly used imaging modality to noninvasively visualize the hip cartilage and labral lesions. However, conventional orthogonal MRI planes encounter unique challenges given the ball-and-socket configuration of the hip joint, its anatomically abducted and anteverted orientation, and the thin, closely apposed cartilage enveloping the femoral head and acetabulum. Advancements in hip MRI's radial plane, which is acquired through the center of the hip joint, offer a solution. This technology provides true cross-sectional images of the cartilage and labrum perpendicular to the curvature of the joint, thereby mitigating the partial-volume-averaging effects. The integration of 3.0-Tesla high field strength and three-dimensional (3D) acquisition techniques further enhances the capabilities of the radial plane. This combination yields a high signal-to-noise ratio, high spatial resolution, high contrast between intraarticular structures, while minimizing partial-volume-averaging effects. Such improvements potentially facilitate the comprehensive detection of even minor chondral and labral lesions. The capability for multiplanar reconstruction from a single 3D volumetric acquisition further strengthens the usefulness of the radial plane by aiding in precise localization of hip cartilage and labral lesions, in line with hip arthroscopy findings. These advancements have the potential to standardize MRI evaluations and radiographic reporting systems for hip cartilage and labrum, offering precise guidance for hip arthroscopy. This article presents a comprehensive review of radial plane technology applied to the hip MRI, and discusses the morphological assessment and localization of hip cartilage and labral lesions utilizing this advanced imaging technique. EVIDENCE LEVEL: 5 TECHNICAL EFFICACY: Stage 2.

Mid- to Long-Term Outcomes in Patients After Hip Arthroscopy With Labral Reconstruction: A Systematic Review

Background

There is a paucity of aggregate data documenting mid- to long-term outcomes of patients after hip arthroscopy with labral reconstruction.

Purpose

To report mid- to long-term outcomes in patients after undergoing either primary or revision hip arthroscopy with labral reconstruction for the treatment of irreparable labral tears.

Study Design

Systematic review; Level of evidence, 4.

Methods

A systematic review of the PubMed, Cochrane, and Scopus databases in May 2022 was conducted with the following keywords: "hip arthroscopy,""labral reconstruction,""irreparable,""labrum,""reconstruction,""five-year,""midterm,""5 year,""long-term,""10 year," ten-year," and "femoroacetabular impingement" using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. Midterm was defined as mean 5-year follow-up, and long-term was defined as mean 10-year or longer follow-up. For each included article, the demographic, radiographic, intraoperative, and surgical variables, as well as patient-reported outcomes (PROs), psychometric thresholds, and secondary surgeries were recorded. Forest plots were created for PROs that were reported in ≥3 studies; heterogeneity was assessed using I2 values.

Results

Out of 463 initial articles, 5 studies including 178 hips with primary and 41 hips with revision surgeries were included. One study had an average 5-year follow-up, three studies had a minimum 5-year follow-up and one study had a minimum 10-year follow-up. The most common indications for hip arthroscopy with labral reconstruction were irreparable labral tears. The most common PRO was the modified Harris Hip Score (mHHS), which was reported in all 5 studies. The mean preoperative mHHS ranged from 58.9 to 66, and the mean postoperative mHHS at minimum 5-year follow-up ranged from 80.2 to 89. The preoperative and postoperative mHHSs for the single long-term follow-up study were 60 and 82, respectively. All 5 studies demonstrated significant improvements in reported PROs. All 5 studies reported secondary surgery rates, with 1 study reporting rates at both 5- and 10-year follow-up. Conversion to total hip arthroplasty ranged from 0% to 27%, while overall secondary surgery rates ranged from 0% to 36%.

Conclusion

Findings demonstrated that patients undergoing primary and revision hip arthroscopy with labral reconstruction experienced favorable outcomes and high rates of clinical benefit and survivorship at mid- to long-term follow-up.

A New Clinical Examination Algorithm to Prescribe Conservative Treatment in People with Hip-Related Pain

Hip-related pain is a common issue in active adults affecting their quality of life, mobility, and overall function, and it can lead to persistent disability. However, diagnosing hip-related pain is challenging due to the many potential sources and causes, including intra-articular and extra-articular pathology, and referred pain from other areas (lumbar or groin related pain). To address this, there is a need for a clinical algorithm based on the best available evidence and expert consensus. This algorithm could guide healthcare professionals in assessing and managing patients with hip-related pain, during the diagnosis, test selection, intervention, monitoring, and promoting collaboration among various healthcare providers. This clinical algorithm for hip-related pain is a comprehensive, flexible, adaptable to different settings, and regularly updated to incorporate new research findings. This literature review aims to establish a clinical algorithm specifically for prescribing exercise treatment to patients with hip-related pain, addressing their individual needs and enhancing their overall care.

Covariance in human limb joint articular morphology

OBJECTIVES

Limb synovial joints exhibit complex shapes that must accommodate often-antagonistic demands of function, mobility, and stability. These demands presumably dictate coordination among joint articular shapes, but the structure of morphological covariance within and among joints is unknown. This study analyzes the human shoulder, elbow, hip, and knee to determine how articular covariance is structured in relation to joint structure, accessory cartilage, and function.

MATERIALS AND METHODS

Surface models were created from the CT scans of 200 modern skeletons from the University of Tennessee Donated Skeletal Collection. Three-dimensional landmarks were collected on the shoulder, elbow, hip, and knee joints. Two-block partial least squares were conducted to determine associations between surfaces of conarticular shapes, functionally analogous articulations, and articulations belonging to the same bone.

RESULTS

Except for the components of the shoulder, all conarticular pairs exhibit covariance, though the strength of these relationships appears unrelated to the amount of accessory cartilage in the joint. Only the analogous articulations of the humerus and femur exhibit significant covariance, but it is unlikely that this pattern is due to function alone. Stronger covariance within the lower limb than the upper limb is consistent broader primate patterns of within-limb integration.

DISCUSSION

With the exception of the elbow, complementary joint function does not appear to promote strong covariance between articulations. Analogous humeral and femoral surfaces are also serially homologous, which may result in the articular associations observed between these bones. Broadly, these patterns highlight the indirect relationship between joint congruence and covariance.

Particularities on Anatomy and Normal Postsurgical Appearances of the Hip

Detailed knowledge of anatomy helps to understand pathologic processes. This article focuses on the anatomy and functionality of the hip, with emphasis on recently studied concepts and anatomic features that have an association with the development of symptoms. The most common anatomic variants posing a challenge for diagnosis and other common findings in asymptomatic patients are reviewed. Good understanding of the different surgical procedures helps in providing as much information as possible to guarantee a favorable outcome, improving prognosis. We review what are the commonly expected postsurgical appearances and the most common postsurgical complications.

Return to sport after arthroscopic surgery for femoroacetabular impingement

BACKGROUND

Femoroacetabular impingement (FAI) is common among the active and young population. The present study analysed the rate of return to sport, related influencing factors, and the sport activity level according to the Hip Outcome Score - Sport-Specific Subscale (HOS-SSS).

METHODS

The literature search was performed in December 2020. All clinical trials investigating HOS-SSS and/or return to sport after arthroscopic treatment for FAI were considered for inclusion. The outcomes of interest were to analyse the rate of return to sport and the sport activity level according to the HOS-SSS in patients who underwent arthroscopic osteoplasty for FAI.

RESULTS

Data from 41 studies (4063 procedures) were retrieved. A total of 88.75% (581 of 655) of patients returned to sports within a mean of 37.4 ± 16.5 months. The HOS-SSS score improved from 45.0 ± 10.6 to 73.1 ± 9.5 (P < 0.0001) at last follow-up. The following baseline characteristics evidenced positive association with post-operative activity level: lighter weight (P = 0.01), younger age (P = 0.001), Tönnis angle grade I (P = 0.009), greater HHS (P = 0.01), NAHS (P < 0.0001) and HOS-ADL (P = 0.01).

CONCLUSION

Arthroscopic treatment for FAI resulted in excellent results in terms of return to sport. Moreover, lighter weight and younger age, greater HHS, NAHS, HOS-ADL at baseline were positively associated with post-operative sport activity level.

LEVEL OF EVIDENCE

IV, systematic review.

Biomolecules-releasing click chemistry-based bioadhesives for repairing acetabular labrum tears

Currently, there are no effective clinical or experimental treatments to fully restore the function of the torn acetabular labrum. To fill the gap, here, we report the finding of progenitor cells in labral tissue, which can be recruited and stimulated to repair torn acetabular labral tissue. This study aimed to develop a biomolecule releasing bioadhesive which can speed up labral tissue healing by eliciting autologous labral progenitor cellular responses. A click chemistry-based bioadhesive, capable of releasing biomolecules, was synthesized to exert ~3× adhesion strength compared with fibrin glue. Via the release of platelet-derived growth factor (PDGF), the adhesive was shown to actively recruit and stimulate the proliferation of labral progenitor cells to the tear sites and within the adhesive. Finally, the ability of this biomolecules-releasing adhesive designed to promote labral tissue regeneration was evaluated using discarded human acetabular labrum tissue compared with surgical suture ex vivo. Histological analysis shows that PDGF-releasing bioadhesive yielded significantly more labrum cell responses and extracellular matrix protein (proteoglycan and collagen) production at the tear tissue site than surgical suture controls. The results confirm that the new PDGF-releasing bioadhesive can activate the responses of autologous labral progenitor cells to significantly improve labral tissue regeneration. Clinical significance: These PDGF-releasing bioadhesives may serve as a new and effective tool for repairing and regenerating acetabular labrum tears.

Hip Pain Increases With Age and Experience Level in Adult Karate Athletes: A Statewide Survey Study

Purpose

To investigate the prevalence of hip pain from labral tears and femoroacetabular impingement (FAI) in karate athletes using a statewide online survey.

Methods

An anonymous electronic survey was distributed via Qualtrics to all registered members of a statewide karate organization who were a purple belt or higher. Basic demographic information was collected as well as belt level, competitive level, and information regarding hip pain and treatment for hip pain. Microsoft Excel was used to store and analyze data.

Results

Of 180 respondents, 123 (68.3%) never had hip pain when practicing karate, and 54 (30.0%) had hip pain at some point in their karate career. Three subjects did not provide an answer and were excluded. Furthermore, of the symptomatic individuals, 52 reported the location of their hip pain, whereas 2 subjects did not. Of the symptomatic individuals (54), 32 had formal diagnoses by a medical professional, 4 (12.5%) were diagnosed with FAI of the hip, 6 (18.8%) diagnosed with a hip labral tear, 3 (9.4%) diagnosed with hip bursitis, 3 (9.4%) diagnosed with hip arthritis, and 16 (50%) had other diagnoses. The remaining 22 participants have not received a formal diagnosis by a medical professional.

Conclusions

The prevalence of hip pain in karate athletes in this survey was lower compared to athletes of other martial arts and kicking sports. No differences in the percentage of injuries were found between sex and years practiced; however a higher incidence of hip pain was found between elite status and age group. When evaluating hip pain in the karate population, orthopaedic surgeons should maintain an index of suspicion for FAI and hip labral tears.

Level of Evidence

Level IV, retrospective cross-sectional study.

The clinical outcomes of arthroscopic hip labral repair: a comparison between athletes and non-athletes

The objective of this study is to compare the clinical outcomes after arthroscopic hip labral repair in athletes and non-athletes. The design of this study is a retrospective comparative study. The setting of this study is an institutional study. One hundred and sixteen patients of hip labral tears who underwent arthroscopic labral repair were included. Eighty-five of these patients met the inclusion/exclusion criteria (25 athletes and 60 non-athletes). Hip labral tears underwent arthroscopic labral repair. The main outcome measures are as follows: visual analog scale (VAS) and modified Harris Hip Score (mHHS) 2 years postoperatively and the rate of return to sports at previous level. There was no significant difference in the gender, alpha angle, lateral center-edge angle between the two groups, except for the mean age (19.3 versus 42.2, P &lt; 0.001), Marx activity rating scale (MARS) (14.6 versus 6.8, P &lt; 0.001) and University of California, Los Angeles (UCLA) activity rating scale (9.6 versus 5.0, P &lt; 0.001). The intraoperative findings were similar in the two groups. The VAS scores and mHHS both showed a significant improvement after surgery in both groups (VAS improvement 3.6 and mHHS improvement 22.4 in the athlete group; VAS improvement 3.9 and mHHS improvement 25.0 in the non-athlete group, all P &lt; 0.001). There was no difference in VAS improvement or mHHS improvement between the athlete and non-athlete groups. All the patients in the athlete group return to sports at previous level 6 months after the operation. The mean time of return to sports at previous level was 5.4 months. Both athletes and non-athletes demonstrate significant VAS and mHHS improvement following arthroscopic labral repair. The VAS scores improvement and mHHS improvement were similar in the athlete and non-athlete groups after arthroscopic labral repair.

Acetabular labral tear is associated with high pelvic incidence with or without femoroacetabular impingement morphology

PURPOSE

The aim of this study was to investigate the association between pelvic sagittal parameters and acetabular labral tears.

METHODS

Three-hundred and sixty-five patients (449 hips) who underwent magnetic resonance imaging (MRI) or magnetic resonance arthrogram (MRA) for hip pain were enrolled in this study. Pelvic sagittal parameters, including the pelvic incidence, pelvic tilt, and sacral slope, were measured with a standing lumbosacral lateral radiograph. All subjects were divided into two groups according to the presence or absence of radiologic acetabular labral tears and compared. Furthermore, the two groups were divided into subgroups according to whether femoroacetabular impingement (FAI) morphology was present or not and compared.

RESULTS

Pelvic incidence was greater in the labral tear group than in the non-labral tear group (52.3° ± 8.2° versus 47.1° ± 6.8°, p < 0.001). After accounting for potentially confounding variables, we found that higher age (odds ratio 1.04, 95% confidence interval [CI] 1.02 to 1.06, p = 0.001), FAI (odds ratio 15.11, 95% CI 7.43 to 30.75, p < 0.001), and high pelvic incidence (odds ratio 1.13, 95% CI 1.09 to 1.17, p < 0.001) were independently associated with acetabular labral tear. When only the patients without FAI (308 hips) were divided into groups with and without acetabular labral tear, we found that higher age (odds ratio 1.03, 95% CI 1.01 to 1.06, p = 0.008) and high pelvic incidence (odds ratio 1.15, 95% CI 1.11 to 1.19, p < 0.001) were independently associated with acetabular labral tear.

CONCLUSION

Acetabular labral tear is associated with high pelvic incidence with or without FAI morphology.

LEVEL OF EVIDENCE

III.

Hip Pain: Imaging of Intra-articular and Extra-articular Causes

Hip pain is a common and complex clinical entity. The causes of hip injuries in athletes are many and diverse, requiring efficient, accurate diagnosis for proper management. Imaging is an important step in the clinical evaluation of hip pain, and familiarity with multiple imaging modalities as well as characteristic imaging findings is a helpful tool for sports medicine clinicians. This article discusses imaging recommendations and gives imaging examples of common causes of intra-articular and extra-articular hip pain including femoroacetabular impingement, labral tears, cartilage defects, ligamentum teres injuries, snapping hip syndrome, femoral stress injuries, thigh splints, athletic pubalgia, avulsion injuries, and hip dislocation.

Patient-Reported Outcomes in Athletes Following Hip Arthroscopy for Femoroacetabular Impingement With Subanalysis on Return to Sport and Performance Level: A Systematic Review

PURPOSE

To identify present trends in demographics, surgical indications, preoperative findings, and surgical treatment of athletes undergoing hip arthroscopy for femoroacetabular impingement and (2) to investigate the outcomes in this patient population, including patient-reported outcome scores (PROS), return-to-sport, complications, and reoperation data at minimum 2-year follow-up in the athletic population.

METHODS

Cochrane, Embase, and PubMed databases were searched according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines to distinguish articles that reported PROS after hip arthroscopy in athletes. Athletes were defined as anyone who played a sport for minimum 2 years at any level. The standardized mean difference was calculated to compare the effect size of hip arthroscopy on various PROS.

RESULTS

Eighteen studies, with 904 athlete hips and a collective study period of January 1993 to April 2017, were included in this systematic review. Across all studies, the mean age and body mass index ranged from 15.7-36.7 years and 20.3-26.3, respectively. The follow-up range was 24-240 months. Mean preoperative alpha angle ranged from 57.7° to 80.0°. Athletes most commonly underwent femoroplasty and labral management. At latest follow-up, the modified Harris Hip Score were excellent in 6 studies (range, 92.1-98), good in 10 studies (range, 84.2-88.5), and fair in 1 study (77.1). Each studies' individual athletic cohort showed significant improvement on the modified Harris Hip Score, Nonarthritic Hip Score, the Hip Outcome Score-Activities of Daily Living, the Hip Outcome Score-Sport-Specific Subscale, visual analog scale for pain, and International Hip Outcome Tool at latest follow-up (P < .05). The return-to-sport rate ranged from 72.7% to 100%, with 74.2-100% of these athletes returning to preinjury or greater level.

CONCLUSIONS

Athletes undergoing arthroscopic hip surgery in the setting of femoroacetabular impingement, not only exhibit significant functional improvement, but also have a high rate of return to sport at the same or greater competition level compared with preinjury level.

LEVEL OF EVIDENCE

IV, systematic review of Level III and IV studies.

The dimensions of the hip labrum can be reliably measured using magnetic resonance and computed tomography which can be used to develop a standardized definition of the hypoplastic labrum

PURPOSE

The purpose of this study was to examine the existing literature to determine the dimensions of the acetabular labrum, with a focus on hypotrophic labra, including the modalities and accuracy of measurement, factors associated with smaller labra, and any impacts on surgical management.

METHODS

Four databases (PubMed, Ovid [MEDLINE], Cochrane Database, and EMBASE) were searched from database inception to January 2020. Two reviewers screened the literature independently and in duplicate. Methodological quality of included papers was assessed using the Methodological Index for Non-Randomized Studies (MINORS) criteria. Where possible, data on labral size were combined using a random effects model.

RESULTS

Twenty-one studies (5 level II, 9 level III, 7 level IV) were identified. This resulted in 6,159 patients (6,436 hips) with a mean age of 34.3 years (range 8.4-85). The patients were 67.3% female with an average follow-up of 57.3 months. There was no consistent definition of labral size quoted throughout the literature. The mean width on MRI/MRA was 7.3 mm (95% CI 6.9-7.8 mm), on computed tomography arthrography was 8.7 mm (95% CI 8.0-9.3), and during arthroscopy was 5.0 mm (95% CI 4.9-5.2). Inter-observer reliability was good to excellent in all modalities. Labral hypotrophy may be associated with increased acetabular coverage. Hypertrophic labra were highly associated with acetabular dysplasia (r = - 0.706, - 0.596, - 0.504, respectively; P < 0.001).

CONCLUSION

Labral width can reliably be measured utilizing imaging techniques including magnetic resonance and computed tomography. The pooled mean labral width was 6.2 mm, and height 4.6 mm. The establishment of a gold-standard of measurement on arthroscopy and advanced imaging would aid in clinical decision-making regarding treatment options for patients presenting with a painful hip, particularly those with hypoplastic labra, and provide radiological guidelines for standardized labrum size classifications.

LEVEL OF EVIDENCE

Level IV.

Generalized Joint Hypermobility Is Associated With Decreased Hip Labrum Width: A Magnetic Resonance Imaging-Based Study

Purpose

To explore the relationship between generalized joint hypermobility and hip labrum width.

Methods

A retrospective review was performed of a single-surgeon database containing patients who underwent hip arthroscopy between 2014 and 2017. Patients were assessed for generalized laxity via Beighton Test Scoring (BTS), which tests for hyperextension of the fifth metacarpophalangeal joint, thumb apposition, elbow hyperextension, knee hyperextension, and trunk flexion on a 9-point scale. Patients were stratified into a "high BTS cohort" with a BTS ≥4, and a control cohort with BTS <4. Magnetic resonance imaging measurements of labral width for each patient were conducted by 2 blinded, musculoskeletal fellowship-trained radiologists at standardized "clockface" locations using a previously validated technique. Statistical analyses used to determine associations between BTS and labral width included Mann-Whitney U and Fisher exact testing as well as linear regression.

Results

Thirty-four patients met inclusion criteria (17 cases, 17 controls). Both groups were composed exclusively of female patients. There was no significant difference between cases or controls in terms of age (33.3 ± 10.4 years vs 35.2 ± 8.3 years, P = .57) or body mass index (26.1 ± 9.3 vs 23.6 ± 3.4, P = .36). The high Beighton score cohort had significantly thinner labrae at the indirect rectus (5.35 ± 1.2 mm vs 7.1 ± 1.1 mm, P < .001) and anterosuperior position (5.53 ± 1.4 mm vs 7.27 ± 1.6 mm, P = .003). There was no statistical difference between the high Beighton score cohort and controls at the psoas U position (6.47 ± 1.6 mm vs 7.43 ± 1.7 mm, P = .112). Linear regression analysis demonstrated Beighton score was significantly negatively associated with labrum width at the indirect rectus position (R² = 0.33, P < .001) and the anterosuperior position (R² = 0.25, P = .004).

Conclusions

Patients with a BTS ≥4 were found to have significantly thinner labra than those with a BTS of <4.

Level of Evidence

III, retrospective comparative trial.

The Prevalence of Cam Morphology: A Cross-Sectional Evaluation of 3,558 Cadaveric Femora

Purpose: We sought to determine (1) the prevalence of cam deformity in the population and that of bilateral cam deformity, (2) the typical location of a cam lesion, and (3) the typical size of a cam lesion by direct visualization in cadaveric femora. Methods: Two observers inspected 3,558 human cadaveric femora from the Hamann-Todd Osteological Collection from the Cleveland Museum of Natural History. Any asphericity >2 mm from the anterior femoral neck line was classified as a cam lesion. Once lesions had been inspected, the prevalence in the population, prevalence by gender, and prevalence of bilateral deformity were determined. Additionally, each lesion was measured and localized to a specific quadrant on the femoral neck based upon location of maximal deformity. Results: Cam lesions were noted in 33% of males and 20% of females. Eighty percent of patients with a cam lesion had bilateral lesions. When stratified by location of maximal deformity, 90.9% of lesions were in the anterosuperior quadrant and 9.1% were in the anteroinferior quadrants. The average lesion measured 17 mm long × 24 mm wide × 6 mm thick in men and 14 mm × 22 mm × 4 mm in women (p < 0.05). Conclusions: The population prevalence of cam deformity determined by direct visualization in cadavers may be higher than has been suggested in studies utilizing imaging modalities. Level of Evidence : Level II, diagnostic study.

Decreased Hip Labral Width Measured via Preoperative Magnetic Resonance Imaging Is Associated With Inferior Outcomes for Arthroscopic Labral Repair for Femoroacetabular Impingement

PURPOSE

To determine the association between labral width as measured on preoperative magnetic resonance imaging (MRI) and hip-specific validated patient self-reported outcomes at a minimum of 2 years' follow-up.

METHODS

We performed an institutional review board-approved retrospective review of prospectively gathered hip arthroscopy patients from 2010 to 2017. The inclusion criteria were defined as patients aged 18 to 65 years with radiographic evidence of femoroacetabular impingement who underwent a primary labral repair and had a minimum of 2 years' clinical follow-up. The exclusion criteria were defined as inadequate preoperative imaging, prior hip surgery, Tönnis grade 1 or higher, or lateral center-edge angle lower than 25°. An a priori power analysis was performed. MRI measurements of labral width were conducted by 2 blinded, musculoskeletal fellowship-trained radiologists at standardized "clock-face" locations using a previously validated technique. Outcomes were assessed using the Harris Hip Score (HHS), modified Harris Hip Score (mHHS), and Non-arthritic Hip Score (NAHS). For the mHHS, scores of 8 and 74 were used to define the minimal clinically important difference and patient acceptable symptomatic state, respectively. Patients were divided into groups by a labral width less than 1 SD below the mean (hypoplastic) or widths above 1 SD below the mean. Statistical analysis was performed using linear and polynomial regression; the Mann-Whitney U, χ², and Fisher exact tests; and intraclass correlation coefficient testing.

RESULTS

A total of 103 patients (107 hips) met the inclusion criteria (mean age, 39.4 ± 17 years; body mass index, 25.0 ± 4; 51% right sided; 68% female patients; mean follow-up, 76.5 ± 19.1 months [range, 30.0-113.0 months]). Mean labral width at the 11:30 clock-face position (indirect rectus), 3-o'clock position (psoas U), and 1:30 clock-face position (point halfway between the 2 aforementioned positions) was 7.1 ± 2.2 mm, 7.0 ± 2.0 mm, and 5.5 ± 1.9 mm, respectively. Intraclass correlation coefficient agreements were good to excellent between readers at all positions (0.83-0.91, P < .001). The preoperative HHS, mHHS, and NAHS were not statistically significantly different (P > .05) between the 2 groups. Sex, laterality, and body mass index were not predictive of outcomes (P > .05). The postoperative HHS, mHHS, and NAHS were found to be significantly lower in the hypoplastic group at each location tested (P < .01), including the mHHS at the 11:30 clock-face position (69 vs 87), 3-o'clock position (70 vs 87), and 1:30 clock-face position (71 vs 87). The proportion of patients with hypoplastic labra who reached the minimal clinically important difference was significantly lower (P < .001) at the 11:30 clock-face position (50% vs 91%), 3-o'clock position (56% vs 90%), and 1:30 clock-face position (58% vs 91%) in comparison to the non-hypoplastic labrum group. The proportion of patients with hypoplastic labra above the patient acceptable symptomatic state was significantly lower (P < .001) at the 11:30 clock-face position (44% vs 83%), 3-o'clock position (37.5% vs 84%), and 1:30 clock-face position (42% vs 85%) in comparison to the non-hypoplastic labrum group. Linear regression modeling was not significant at any position (P > .05). Polynomial regression was significant at the 11:30 clock-face position (R² = 0.23, P < .001), 3-o'clock position (R² = 0.17, P < .001), and 1:30 clock-face position (R² = 0.26, P < .004).

CONCLUSIONS

Hip labral width less than 1 SD below the mean measured via preoperative MRI was associated with significantly worse functional outcomes after arthroscopic labral repair and treatment of femoroacetabular impingement. The negative relation between labral width and outcomes may be nonlinear.

LEVEL OF EVIDENCE

Level IV, case series with subgroup analysis.

Can the Open Stance Forehand Increase the Risk of Hip Injuries in Tennis Players?

Background

The open stance forehand has been hypothesized by tennis experts (coaches, scientists, and clinicians) to be more traumatic than the neutral stance forehand as regards hip injuries in tennis. However, the influence of the forehand stance (open or neutral) on hip kinematics and loading has not been assessed.

Purpose

To compare the kinematics and kinetics at the hip joint during 3 common forehand stances (attacking neutral stance [ANS], attacking open stance [AOS], defensive open stance [DOS]) in advanced tennis players to determine whether the open stance forehand induces higher hip loading.

Study Design

Descriptive laboratory study.

Methods

The ANS, AOS, and DOS forehand strokes of 8 advanced right-handed tennis players were recorded with an optoelectronic motion capture system. The flexion-extension, abduction-adduction, and external-internal rotation angles as well as intersegmental forces and torques of the right hip were calculated using inverse dynamics.

Results

The DOS demonstrated significantly higher values than both the ANS and AOS for anterior (P < .001), medial (P < .001), and distractive (P < .001) forces as well as extension (P = .004), abduction (P < .001), and external rotation (P < .001) torques. The AOS showed higher distractive forces than the ANS (P = .048). The DOS showed more extreme angles of hip flexion (P < .001), abduction (P < .001), and external rotation (P = .010).

Conclusion

The findings of this study imply that the DOS increased hip joint angles and loading, thus potentially increasing the risk of hip overuse injuries. The DOS-induced hip motion could put players at a higher risk of posterior-superior hip impingement compared with the ANS and AOS.

Clinical Relevance

Coaches and clinicians with players who have experienced hip pain or sustained injuries should encourage them to use a more neutral stance and develop a more aggressive playing style to avoid the DOS, during which hip motion and loading are more extreme.

Integrating Osteopathic Manipulative Treatment and Injections in the Diagnosis and Management of a Hip Labral Tear

Hip pain in adults is a common complaint. Secondary processes can often mask underlying conditions, prolonging the course to diagnosis and definitive treatment. In this case, a 74-year-old man presented to an outpatient clinic after 6 weeks of right hip pain that began upon initiation of a rehabilitation program following coronary artery bypass graft surgery. Various imaging and treatment modalities (including radiography, osteopathic manipulative treatment, injection of the greater trochanteric bursa, L2-3 paravertebral block, magnetic resonance imaging, and intra-articular hip injection with 1% lidocaine) ultimately led to the definitive diagnosis of a labral tear. This case report highlights how a comprehensive osteopathic approach was used to evaluate and treat a patient with persistent unilateral hip pain because of an acetabular labral tear, associated psoas syndrome, and trochanteric bursitis, all within 2 months and with a positive clinical outcome.

Validity of Magnetic Resonance Imaging Measurement of Hip Labral Width Compared With Intraoperative Assessment

PURPOSE

To determine if magnetic resonance angiography (MRA) and/or magnetic resonance imaging (MRI) could accurately determine the width of the labrum.

METHODS

Consecutively enrolled patients between the ages of 18 and 65 indicated for hip arthroscopy for femoroacetabular impingement were included between December 2017 and June 2018. Inclusion criteria for preoperative MRIs included: MRI availability in picture archiving and communication system; performance on a 1.5T or 3T MRI or 3T MRA; and adequate quality and lack of labrum ossification. Intraoperative labral width measurements were taken at standardized locations using an established acetabular "clockface" paradigm. Measurement was performed using a calibrated probe. The labral width was defined as the distance from the labrum extended laterally from the acetabular rim. MRI measurements were taken by 2 blinded musculoskeletal fellowship-trained radiologists at the same positions. Measurements were made at the 11:30 o'clock position (indirect rectus) on coronal proton density (PD) sequence, at 3 o'clock position (psoas-U) on axial oblique PD sequence, and at 1:30 (a point halfway between the 2) on sagittal fat-suppressed PD. The surgeons were blinded to the radiologists' measurements and vice versa. Intraoperative and radiographic labral width measurements were compared using an intraclass correlation coefficients (ICC), absolute agreement, and 2-way random effects model. The 2 radiologists' measurements were compared for interrater reliability using the same ICC model.

RESULTS

Fifty-one patients were included (30 females, 26 right hips). Average labrum width at the 3:00, 11:30, and 1:30 o'clock positions by arthroscopic measurement were 5.8 mm (range; standard deviation, 2-8; ±1.4), 6.3 mm (2-10; ±1.5) and 6.0 mm (2-9; ±1.5), and by MRI were 6.3 mm (2-10; ±1.5), 6.7 mm (3-10; ±1.4), and 6.1 mm (2-9; ±1.6), respectively. When including all MRI modalities, ICC agreement between intraoperative assessment, and radiologist assessment at the 3:00 o'clock, 11:30, and point halfway between was 0.82 (P < .001), 0.78 (P < .001), 0.84 (P < .001), respectively. Radiologist interrater ICC agreement at the same points was 0.88 (P < .001), 0.93 (P < .001), and 0.88 (P < .001).

CONCLUSIONS

Strong agreement was found between radiologic and arthroscopic measurement of labrum width when using MRI, suggesting MRI is an accurate way to measure labral width. There was not a significant difference between different MRI modalities. Accurately measuring labral width preoperatively with MRI may aid in surgical decision making.

LEVEL OF EVIDENCE

Level II, diagnostic study.

The anatomical properties of the indirect head of the rectus femoris tendon: a cadaveric study with clinical significance for labral reconstruction surgery

BACKGROUND

Acetabular labral tear is a common pathology. In some clinical situations, primary labral repair may not be possible and labral reconstruction is indicated.

PURPOSE AND CLINICAL RELEVANCE

Describe the anatomy of the indirect head of the rectus femoris (IHRF) tendon with clinical application in arthroscopic labral reconstruction surgery.

METHODS

Twenty-six cadaver hips were dissected. Thirteen measurements, each with clinical relevance to arthroscopic labral reconstruction using an IHRF tendon graft were taken on each hip. All measurements were taken in triplicate. Mean values, standard deviations and intra-observer reliability were calculated.

RESULTS

The mean footprint of the direct head of the rectus femoris tendon was 10.6 mm × 19.6 mm. The width and thickness at the confluence of both heads were 10.9 mm and 6.9 mm, respectively. The mean total length of the footprint and "free portion" of the IHRF was 55.3 mm, the mean cranial to caudal footprint measured at the 12 o'clock, 1 o'clock, and 2 o'clock positions were 22.3 mm. The mean length of the Indirect Head footprint alone was 38.1 mm. The mean length of IHRF tendon suitable for grafting was 46.1 mm and the mean number of clock face sectors covered by this graft was 3.3 clock face sectors. Intra-observer reliability was ≥ 0.90 for all recorded measurements. The origin of the IHRF on the acetabulum fans out posteriorly, becoming thinner and wider as the origin travels posteriorly. The tendon footprint is firmly attached on the lateral wall of the ilium and becomes a free tendon overlying the acetabular bone as it travels anteriorly and distally towards its muscular attachment.

CONCLUSION

The IHRF tendon is in an ideal location for harvesting and contains the appropriate thickness, length and triangular architecture to serve as a safe and local graft source for acetabular labral reconstruction surgery.

Hip and Knee Injuries

Hip and knee injuries are a common presenting concern for patients to a primary care office. This pathology represents a large differential and it can often be a diagnostic challenge for providers to determine the etiology of a patient's symptoms. This article discusses several of the most common causes for hip and knee pain while providing an evidence based review of physical examination maneuvers, imaging studies and treatment modalities to assist a primary care provider when encountering active patients with underlying hip or knee pain.

The Pediatric Hip: A Rare Case of Acetabular Labral Tear and Paralabral Cyst: A Case Report

CASE

We report the case of an active 8-year-old patient with a 2-year history of groin and thigh pain. Magnetic resonance imaging of the hip demonstrated a paralabral cyst arising from a superior labral tear. Arthroscopic labral repair and decompression of the cyst were performed, and the patient remains asymptomatic at 2-year follow-up.

CONCLUSIONS

Acetabular labral tears with concomitant paralabral cysts have been described in the literature in the adult population and successfully treated arthroscopically. We propose that surgeons should be aware of this as a cause for undiagnosed groin and thigh pain in the pediatric population and that arthroscopic management is successful.

The outcome of arthroscopic repair of acetabular labral tears using the iHOT-33

Background

The purpose of this study was to determine patient reported outcome measures (PROMS) after arthroscopic repair of an isolated labral tear using the validated International Hip Outcome Tool (iHOT-33). The iHOT-33 specifically measures (1) symptoms and functional limitations, (2) sport and recreation limitations, (3) job related concerns and social and (4) emotional and lifestyle concerns.

Methods

A retrospective review was performed on 45 procedures in 43 patients between September 2012 and September 2015. Two patients had bilateral isolated labral tears. Patients were excluded if they were younger than 18 years, had prior ipsilateral hip surgery and had radiological or arthroscopic evidence of femoroacetabular impingement (FAI), hip dysplasia or other bony dysmorphism.

Results

Of the 43 patients undergoing arthroscopy there were 29 right and 16 left hips repaired. There were 34 females and 9 males. The mean age at surgery was 37.4 years (range 19–63 years) with a mean follow up of 1.7 years (range 1.0–2.6 years). At follow up the mean total iHOT-33 score improved from 34.1 to 67.3 (p < 0.02). The mean improvement was 33.2 (p = < 0.02). Significant improvements were described in all 4 iHOT-33 sub sections.

Conclusion

The study showed statistically significant favourable outcomes in selected patients with short follow-up for patients that underwent hip arthroscopy for an isolated labral tear using the validated iHOT-33.

Level of Evidence

IV, retrospective non-randomised study.

Diagnosis and treatment of labral tear

Objective:

To review the literature regarding diagnosis and treatment of labral tear.

Data sources:

A systematic search was performed in PubMed using various search terms and their combinations including hip, labrum, acetabular labral tear, arthroscopy, diagnosis, and anatomy.

Study selection:

For each included study, information regarding anatomy, function, etiology, diagnosis, and management of acetabular labral tear was extracted.

Results:

Five hundred and sixty abstracts about anatomy, function, etiology, diagnosis, and management of acetabular labral tear were reviewed and 66 selected for full-text review. The mechanism of labral tear has been well explained while the long-term outcomes of various treatment remains unknown.

Conclusions:

Labral tear is generally secondary to femoroacetabular impingement, trauma, dysplasia, capsular laxity, and degeneration. Patients with labral tear complain about anterior hip or groin pain most commonly with a most consistent physical examination called positive anterior hip impingement test. Magnetic resonance arthrography is a reliable radiographic examination with arthroscopy being the gold standard. Conservative treatment consists of rest, non-steroidal anti-inflammatory medication, pain medications, modification of activities, physical therapy, and intra-articular injection. When fail to respond to conservative treatment, surgical treatment including labral debridement, labral repair, and labral reconstruction is often indicated.

Prevalence of labrum and articular cartilage injuries of the hip on 3T magnetic resonance imaging of asymptomatic elite soccer players

OBJECTIVE

To establish the prevalence of lesions of the labrum and articular cartilage of the hip in asymptomatic elite soccer players by performing 3T magnetic resonance imaging.

METHODS

Eighty-four asymptomatic hips of 42 professional soccer players were evaluated. Male subjects older than 18 years were included. Cam and pincer deformity were defined as an alpha angle greater than 55 degrees and a lateral centre edge angle greater than 39 degrees, respectively. Labral injuries were classified with the Czerny classification and cartilage damage was classified with the Outerbridge classification. Specific statistical tests were used to establish the relationship between anatomical variances of the hip and the presence of chondral and labral injuries.

RESULTS

FAI morphology prevalence was 25%. Abnormalities such as cam (22.5%) and labral injuries (33.8%) were found. Those cases with reported labral injury were predominantly intrasubstance damage (18.8%). Anatomical features of FAI were found to be related to lesions of the femoral cartilage (P<.001), chondrolabral damage (P=.042), or both injuries (P<.001).

CONCLUSION

Asymptomatic labral or cartilaginous injuries of the hip were reported in 25% of the included professional soccer players. These injuries were associated with anatomical features of FAI.

Graft choices for acetabular labral reconstruction

The acetabular labrum plays a key role in maintaining hip function and minimizing hip degeneration. Once thought to be a rare pathology, advances in imaging have led to an increase in the number of diagnosed labral tears. While still a relatively new field, labral reconstruction surgery is an option for tears that are irreparable or require revision after primary repair. Various autograft and allograft options exist when considering labral reconstruction. The first labral reconstruction surgery was described using the ligamentum teres capitis, and has since evolved, incorporating more graft sources and reconstructive techniques. The purpose of this review is to assess and describe the different graft sources and technique currently implemented by hip surgeons. Moreover, this review attempts to determine whether a single labral reconstructive graft type is superior to the others. Techniques using the Ligamentum teres capitis autograft, ITB autograft, gracilis autograft, quadriceps tendon autograft, capsular autograft, semitendinosus allograft, indirect head of the rectus femoris autograft, peroneus brevis tendon allograft and Tensor fascia lata allograft were found. Scoring was available on 5 out of the 9 graft types. The advantages and disadvantages of each graft source is described as a comparative tool. No single graft type has shown increased benefit in acetabular labral reconstruction. The lack of uniform outcome measurements hinders comparison of reported outcomes. Surgeons should make an informed decision based on their experience as well as the patient's history and needs when choosing which graft type would be best suited for their patients.

Acetabular labrum of hip joint in osteoarthritis: A qualitative original study and short review of the literature

PURPOSE

Histological architecture of normal acetabular labrum regarding free nerve endings (FNEs) and mechanoreceptors (MRs) has been satisfactorily described in the literature. However, the presence of FNEs and MRs in acetabular labrum of hip joint has been analyzed only once in patients with osteoarthritis (OA). Aim of this article is to report histological distribution pattern of FNEs and MRs in acetabular labrum of patients with severe OA, at the same time conducting a comparison with normal acetabular labrum described in the literature.

METHODS

Seven patients with severe hip OA were enrolled in this study. Patient selection was assisted by the utilization of specific clinical scales delineated by the American College of Rheumatology. After successful total hip arthroplasty, tissue samples of acetabular labra of seven patients were histologically processed and stained with the gold standard chloride method, which was subsequently examined under a compound microscope.

RESULTS

FNEs and MRs constituted the major histological structures. Identified MRs included Pacini corpuscles, Ruffini corpuscles, and Golgi-Mazzoni corpuscles. The presence of FNEs was predominant in the middle part of the acetabular labrum, featuring a remarkable decrease in peripheral parts. In contrast, MRs were detected basically in peripheral parts and less in the middle part.

CONCLUSIONS

Differentiation of the distribution pattern of MRs and FNEs in acetabular labrum of hip joint is remarkable between normal patients and patients with severe OA. The abundance of FNEs in the middle part of the pathologic labrum is mainly responsible for the observed discrimination. A "conversion" of MRs to FNEs may occur during OA progression, modulating therefore this pattern as well as the upcoming clinical manifestations.

Basics in hip chondrolabral lesions and state of the art

Chondrolabral complex is a weak point along an histological transition zone. Most cartilage and labral lesions in the femoroacetabular impingement syndrome are located in this area. Different classifications are used to evaluate the severity and predict the prognosis of chondrolabral complex injuries. Acetabular Labrum Articular Disruption (ALAD) and Multicenter Arthroscopy of the Hip Outcomes Research Network (MAHORN) classifications are commonly used with a prognosis and treatment implication. Treatment of chondrolabral lesions detected on magnetic resonance imaging (MRI), should only be considered when clinical symptoms are presented. A wide range of treatment options include debridement with or without microfracture, repair or regenerate therapies. The future of hip joint preservation should be directed towards to the development of the treatment of chondrolabral injuries.

Arthroscopic internal drainage and cystectomy of popliteal cyst in knee osteoarthritis

Background

The purpose of this study was to evaluate the efficacy of arthroscopic knee cavity internal drainage and cyst cavity debridement operation of popliteal cyst in knee osteoarthritis patients.

Methods

From August 2007 to March 2013, 58 knee osteoarthritis patients with popliteal cyst were treated with arthroscopic knee cavity internal drainage through posteromedial portal and popliteal cyst cavity debridement through superior posteromedial portal. In all patients, preoperative magnetic resonance imaging (MRI) was performed to detect combined intra-articular pathology and the communication between popliteal cyst and knee cavity. Clinical efficacy was evaluated through VAS score and Lysholm score.

Results

All patients had neither recurrence of popliteal cyst nor complaints of pain, swelling, or functional impairment at average 24 months follow-up after surgery. Postoperatively, VAS score was decreased significantly and Lysholm score was raised significantly comparing preoperatively.

Conclusion

Arthroscopic knee cavity internal drainage operation through posteromedial portal and popliteal cyst cavity debridement through superior posteromedial portal is an effective minimally invasive surgery method for the treatment of popliteal cyst without recurrence in knee osteoarthritis patients.

Sports Injuries about the Hip: What the Radiologist Should Know

Injuries of the hip and surrounding structures represent a complex and commonly encountered scenario in athletes, with improper diagnosis serving as a cause of delayed return to play or progression to a more serious injury. As such, radiologists play an essential role in guiding management of athletic injuries. Familiarity with hip anatomy and the advantages and limitations of various imaging modalities is of paramount importance for accurate and timely diagnosis. Magnetic resonance (MR) imaging is often the modality of choice for evaluating many of the injuries discussed, although preliminary evaluation with conventional radiography and use of other imaging modalities such as ultrasonography (US), computed tomography, and bone scintigraphy may be supplementary or preferred in certain situations. Stress fractures, thigh splints, and posterior hip dislocations are important structural injuries to consider in the athlete, initially imaged with radiographs and often best diagnosed with MR imaging. Apophyseal injuries are particularly important to consider in young athletes and may be acute or related to chronic repetitive microtrauma. Femoroacetabular impingement has been implicated in development of labral tears and cartilage abnormalities. Tear of the ligamentum teres is now recognized as a potential cause of hip pain and instability, best evaluated with MR arthrography. Greater trochanteric pain syndrome encompasses a group of conditions leading to lateral hip pain, with US playing an increasingly important role for both evaluation and image-guided treatment. Muscle injuries and athletic pubalgia are common in athletes. Lastly, snapping hip syndrome and Morel-Lavallée lesions are two less common but nonetheless important considerations. ^©RSNA, 2016.

Outcomes of Hip Arthroscopy in Competitive Athletes

PURPOSE

To evaluate the minimum 2-year postoperative clinical outcomes and the rate of return to sports in athletes who underwent capsular plication for the treatment of ligamentous laxity and/or borderline dysplasia during hip arthroscopy for the treatment of femoroacetabular impingement and labral pathology.

METHODS

Since 2008, data were prospectively collected on patients who underwent hip arthroscopy for the treatment of femoroacetabular impingement and/or labral tears. Inclusion criteria were as follows: athlete at the high school, collegiate, or professional levels preoperatively, underwent capsular plication, and preoperatively recorded patient-reported outcome scores including modified Harris hip score (mHHS), nonarthritic athletic hip score (NAHS), hip outcome score-sports-specific subscale (HOS-SSS), and visual analog scale (VAS). Exclusion criteria were as follows: <16 years old, preoperative Tönnis grade >1, and previous hip conditions. Sports activity and competitive levels were collected at a minimum of 2 years postoperatively.

RESULTS

Fifty-one hips (49 patients) met the inclusion criteria, and 41 hips (39 patients) had minimum 2-year follow-up (80.4% follow-up). Mean mHHS increased from 67.1 preoperatively to 83.5 (P < .0001). Mean NAHS increased from 66.8 to 88.8 (P < .0001). Mean HOS-SSS improved from 46.8 to 80.1 (P < .0001). Mean VAS decreased from 5.1 to 1.7 (P < .0001). Thirty-five (85.4%) hip arthroscopies allowed the patients to return to sports at follow-up. Thirty-four (82.9%) hip arthroscopies allowed the patients to maintain their competitive physical abilities at follow-up.

CONCLUSIONS

Patient-reported outcomes and VAS in athletes significantly improved at a minimum of 2 years after capsular plication as a part of hip arthroscopy addressing varying pathologies. In addition, most patients returned to sports at similar or higher competitive levels. These results suggest that capsular plication is a favorable treatment option in athletes with ligamentous laxity and/or borderline dysplasia.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Decision Making for Labral Treatment in the Hip: Repair Versus Débridement Versus Reconstruction

The role and function of the acetabular labrum have been studied extensively in the past decade. Recent studies have proposed that, in addition to causing pain and mechanical symptoms, labral tears may accelerate arthritis. Labral preservation is believed to be important because of the role the labrum plays in maintaining a healthy joint. Treatment of the acetabular labrum is becoming one of the fastest growing fields in orthopaedics; therefore, the treatment decision-making process must be refined. Currently, three commonly practiced labral treatments are available: repair, débridement, and reconstruction. Arguments for and against each treatment option exist in the literature. Reviewing the currently proposed indicators for labral tear treatments in conjunction with the treatment procedures yields a thorough decision-making guide for choosing the appropriate labral procedure.

Arthroscopic Capsular Reconstruction of the Hip With Acellular Dermal Extracellular Matrix: Surgical Technique

Atraumatic instability of the hip has become an increasingly studied occurrence in recent years. There are several established surgical techniques that help restore stability of the native hip joint. In some cases, these procedures are not an option. As the phenomenon has become recognized more frequently, a greater number of revision surgeries are warranted in patients with ligamentous laxity. A durable solution for irreparable microinstability needs to be formulated to address this vulnerable patient demographic. We describe the surgical technique for capsular reconstruction with acellular dermal extracellular matrix.

The Hip in Ice Hockey: A Current Concepts Review

Ice hockey is a fast, physical sport with unique associated biomechanical demands often placing the hip in forced and repetitive supraphysiological ranges of motion. Ice hockey players commonly endure and are sidelined by nebulous groin injury or hip pain. Underlying causes can be chronic or acute and extra-articular, intra-articular, or "hip-mimicking." This article serves to review common hip-related injuries in ice hockey. For each, we define the particular condition; comment on risk factors and preventive strategies; discuss key historical, physical examination, and imaging findings; and finally, suggest nonoperative and/or operative treatment plans.

Clinical and surgical correlation of hip MR arthrographic findings in adolescents

OBJECTIVE

The purpose of this study was to analyze the utility of MRA-H in adolescents by comparing the results of imaging with surgical findings and/or clinical outcome.

MATERIAL AND METHODS

After obtaining appropriate IRB approval, the Radiologic Information System database was queried for all patients 13-18 years of age who underwent MRA-H from 2004 through 2013. The electronic medical record was reviewed for clinical history, clinical examination findings, and operative notes. MRA-H images were reviewed for soft tissue abnormalities (labral tear, paralabral ganglion, articular cartilage loss, synovitis, ligament tears) and bony abnormalities (cam-type femoroacetabular impingement (FAI), pincer-type FAI, hip dysplasia). MRA-H findings were correlated with surgical findings and with clinical outcomes.

RESULTS

Twenty-six patients with labral tears by MRA-H were included in study and grouped as follows: Group I) patients who underwent surgical management (n=10); group II) patients managed non-surgically (medication, intra-articular injection, physical therapy) (n=9); group III) patients lost to follow up after being advised to have surgery (n=7). With regard to presenting symptomatology, 87.5% of patients with labral tear had groin pain. Of those patients who were diagnosed with a labral tear, 52% were categorized as idiopathic labral tears, 26% as secondary tears (secondary to abnormal bony morphology), and 22% as traumatic labral tears. The labral tears were found to be anterior in 61% and posterior in 22%. Associated articular cartilage lesions were found in 29% of patients. In group I (surgical patients), MRA-H labral findings were confirmed at surgery in 9/10. Seventy percent of labral tears in our study had some form of abnormal bony morphology. Nine of the 12 patients with bone abnormalities were derived from group I patients. Six out of 7 patients with cam-type FAI had a labral tear.

CONCLUSION

Labral tears diagnosed by MRA-H in the adolescent population correlated well with clinical examination and surgical findings. Also, MRA-H contributed by defining bony morphology that was directly applied to surgical management. Non-surgical management of labral tears diagnosed on MRA-H had a generally favorable outcome.

Assessment of cartilage contact pressure and loading in the hip joint during split posture

PURPOSE

Given the crucial role of the mechanical behavior in the degenerative process of the hip joint, analyzing the contact mechanics in the articular layers during physical activities could contribute to understanding the pathology. Indeed, the development process of hip osteoarthritis generally evolves over a long time period, and therefore analyzing the mechanical behavior of the hip joint during extreme repetitive movements will be helpful to analyze degeneration causes. The aim of the study was to investigate the link between the excessive movements and the development of hip osteoarthritis.

METHODS

To individualize the analysis, we used a subject-specific and noninvasive approach based on finite element analysis and magnetic resonance imaging (MRI) data. The contact pressure distribution and loading conditions on the acetabular cartilage were assessed on eleven professional dancer subjects performing a split movement. This movement is frequently practiced (repetitive) by dancers during their daily exercises. Moreover, split postures are mostly characterized by high anatomical angles with subluxation (excessive). To ensure the motion accuracy, MRI data of the subjects were acquired in neutral and split positions performed inside the MRI scanner. Based on the reconstructed bone models from the MRI data, a motion tracking approach was used to compute the transformation between the two poses. To evaluate the contact during the split movement and to quantify the role of the labrum in the hip joint mechanics, additional simulations of two daily activities (walking and stand-up) were performed. Finally, a clinical study based on morphological and radiological analysis of the subjects was performed and validated by orthopedic surgeons and radiological experts to evaluate the proposed approach.

RESULTS

The reconstructed split movement was characterized by high anatomical angles with a subluxation on the left hip. Consequently, strong deformations and pressures were observed during the simulation. The comparison of the simulation results of split posture and daily activities showed higher pressure and lower contact area during extreme movements. Moreover, the presence of labrum absorbed part of load and consequently decreased the predicted contact pressure and contact area on the acetabular cartilage.

CONCLUSION

The comparison of the simulation results of the split posture and daily activities, as well as the correlation between the results of the analysis on extreme movement results and the clinical analysis performed by medical experts, strongly suggests that repetitive extreme movement could lead to early hip osteoarthritis.

Tissue engineering and the future of hip cartilage, labrum and ligamentum teres

As the field of hip arthroscopy continues to evolve, the biological understanding of orthopaedic tissues, namely articular cartilage, labral fibro-cartilage and the ligamentum teres continues to expand. Similarly, the need for biological solutions for the pre-arthritic and early arthritic hip continues to be a challenge for the sports medicine surgeon and hip arthroscopist. This article outlines existing biological and tissue-engineering technologies, some being used in clinical practice and other technologies being developed, and how these biological and tissue-engineering principals may one day influence the practice of hip arthroscopy. This review of hip literature is specific to emerging biological technologies for the treatment of chondral defects, labral tears and ligamentum teres deficiency. Of note, not all of the technologies described in this article have been approved by the United States Food and Drug Administration and some of the described uses of the approved technologies should be considered 'off-label' uses.

Femoroacetabular Impingement in Elite Ice Hockey Goaltenders: Etiological Implications of On-Ice Hip Mechanics

BACKGROUND

Femoroacetabular impingement (FAI) is particularly prevalent in ice hockey. The butterfly goalie technique is thought to involve extreme ranges of hip motion that may predispose goaltenders to FAI.

PURPOSE

To quantify hip mechanics during 3 common goaltender movements and interpret their relevance to the development of FAI.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Fourteen collegiate and professional goaltenders performed skating, butterfly save, and recovery movements on the ice. Hip mechanics were compared across the 3 movements.

RESULTS

The butterfly did not exhibit the greatest range of hip motion in any of the 3 planes. Internal rotation was the only hip motion that appeared close to terminal in this study. When subjects decelerated during skating—shaving the blade of their skate across the surface of the ice—the magnitude of peak hip internal rotation was 54% greater than in the butterfly and 265% greater than in the recovery. No movement involved levels of concomitant flexion, adduction, and internal rotation that resembled the traditional impingement (FADIR) test.

CONCLUSION

The magnitude of internal rotation was the most extreme planar hip motion (relative to end-range) recorded in this study (namely during decelerating) and appeared to differentiate this cohort from other athletic populations. Consequently, repetitive end-range hip internal rotation may be the primary precursor to symptomatic FAI in hockey goaltenders and provides the most plausible account for the high incidence of FAI in these athletes. Resection techniques should, therefore, focus on enhancing internal rotation in goaltenders, compared with flexion and adduction. While the butterfly posture can require significant levels of hip motion, recovering from a save and, in particular, decelerating during skating are also demanding on goaltenders' hip joints. Therefore, it appears critical to consider and accommodate a variety of sport-specific hip postures to comprehensively diagnose, treat, and rehabilitate FAI.

Is labral hypotrophy correlated with increased acetabular depth?

Labral hypertrophy is a distinct feature in hip dysplasia. Occasionally, very small, hypotrophic labra are observed. However, there is no literature concerning this pathology. We investigated if the size of the labrum correlated with any radiologic parameters reflecting the amount of acetabular coverage. It was hypothezised that there is a negative correlation between labrum size and acetabular coverage. Labra were categorized into three groups depending on the relation between length of the articular sided surface and height of bony attachment. Labra with a height:length ratio of 2 were classified as hypotrophic, with a height:length ratio of 1 as normal and with a ratio of 0.5 as hypertrophic. Labral cross-sectional areas (CSA) were measured on radial magnetic resonance imaging-arthrography slices using the measuring tool of the PACS system of 20 hips with hypotrophic labra (group 1), 20 hips with normal labral appearance (group 2) and 10 hips with hypertrophic labra (group 3). These values were then analyzed against following parameters: neck-shaft-angle (NSA), lateral center-edge angle (LCE), acetabular index (AI), femoral extrusion index (FEI) and acetabular retroversion index (ARI). Analyses of variance were used to determine differences in mean values between the three groups. Mean labral CSA differed significantly between all groups (group 1: 12.1 ± 2.9 mm²; group 2: 25.2 ± 6.2 mm²; group 3: 41.1 ± 12.3 mm²; P < 0.001). NSA, LCE, AI and FEI all showed a significant difference between group 3 and 1 or 2. The ARI showed no difference between groups. Stepwise linear regression analyses showed a significant correlation between LCE angle and labral CSA with a corrected R²-value of 0.301. Labral CSA correlates with the LCE. No statistically significant difference between groups 1 and 2 concerning the LCE, AI or FEI could be identified. Nevertheless, group 1 had the highest mean coverage of all groups, hips with hypertrophic labra the lowest.

The gymnasts' hip and groin: a magnetic resonance imaging study in asymptomatic elite athletes

OBJECTIVE

Specific patterns of developmental adaptation of the proximal femur have been recognized in some sports. Gymnastics are characterized by repetitive axial loading and hip rotations in combination with extreme hip positions. It is unknown how and if these forces can affect an immature skeleton in the long term. We sought to evaluate this, by means of magnetic resonance imaging of the hip and groin of such elite asymptomatic athletes.

MATERIALS AND METHODS

We performed a case-control comparative MR imaging study of both hips and groin of 12 (7 male, 5 female) skeletally mature young (mean age 18.6 years) asymptomatic international level gymnasts with a minimum of 10 years' training with age-matched non-athletes. At the time of recruitment, none of the athletes had a recorded musculoskeletal complaint or injury in the anatomical area around the hip.

RESULTS

The study showed that elite gymnasts share four common morphological characteristics on MRI that deviate from normal and are considered to be the result of adaptational changes to the specific sport: high centre-column-diaphysis angle (coxa valga140° on average), ligamentum teres hypertrophy, friction of the iliotibial band with oedema surrounding the greater trochanter, and a high incidence (62.5 %) of radiological appearances of ischiofemoral impingement.

CONCLUSION

Our study showed that elite gymnasts share four common morphological characteristics on MRI that deviate from normal. These findings were in asymptomatic subjects; hence, radiologists and sports physicians should be aware of them in order to avoid unnecessary treatment.

[Hip arthroscopy in males younger than 40 with femoroacetabular impingement: short-term outcomes]

INTRODUCTION AND OBJECTIVES

Femoroacetabular impingement is probably the most common mechanism that leads to the development of early cartilage and labral damage in the non-dysplastic hip. The objective was to evaluate the outcomes of hip arthroscopy as a treatment for femoroacetabular impingement in patients with high level of function.

MATERIAL AND METHODS

A prospective study was performed on 41 patients younger than 40 years old undergoing hip arthroscopy for femoroacetabular impingement. Modified Harris Hip Score and HOS and IHOT questionnaires were used for clinical assessment. Radiological evaluation was made for joint space and alpha angle.

RESULTS

The mean age of patients was 32.7 years. Labrum injury was detected in 78%, and acetabular cartilage injury in 56% of cases. The average follow-up was 31.3 months. There was a significantly improvement in the mean score in the clinical questionnaires. Radiologically there was no change in the mean joint space, with significantly reduction to normal values of the alpha angle. All patients returned to sports at their pre-injury level of function.

DISCUSSION

Hip arthroscopy resulted in improvement in hip functional outcomes with correction of the underlying osseous deformity and treatment of the associated labral and cartilage pathology, with the return of patients to their pre-injury sports. Further follow-up is essential to confirm the stability of the clinical and radiological outcomes.

Nonarthritic hip joint pain

The Orthopaedic Section of the American Physical Therapy Association (APTA) has an ongoing effort to create evidence-based practice guidelines for orthopaedic physical therapy management of patients with musculoskeletal impairments described in the World Health Organization's International Classification of Functioning, Disability, and Health (ICF). The purpose of these clinical practice guidelines is to describe the peer-reviewed literature and make recommendations related to nonarthritic hip joint pain.

Effect of warmed irrigation solution on core body temperature during hip arthroscopy for femoroacetabular impingement

PURPOSE

To determine the effect of warming arthroscopic irrigation solution on core body temperature during hip arthroscopic surgery in patients with femoroacetabular impingement.

METHODS

An analytical, prospective, observational study was performed in a cohort of 166 consecutive patients. All patients underwent hip arthroscopy for treatment of femoroacetabular impingement. Two groups were studied: patients operated on with arthroscopic irrigation solution warmed up to 32°C ± 2°C (89.6°F ± 3.6°F) and a control group comprising patients operated on with irrigation solution used at room temperature. Relevant information was collected regarding the patients (age, sex, body mass index, and blood pressure) and the procedure (volume and temperature of saline solution, pressure of fluid pump, surgery time, and room temperature). Corresponding statistical analysis was performed with STATA 11.0 (StataCorp, College Station, TX), by use of descriptive statistics, parametric and nonparametric tests, and a generalized estimating equation model for repeated measurements.

RESULTS

Both groups were comparable in terms of age, sex, systolic and diastolic blood pressure, body mass index, volume of irrigation solution used, and room temperature. The mean age of the cohort was 33 years (range, 14 to 60 years); mean body mass index, 23.7 kg/m(2) (range, 17.2 to 34 kg/m(2)); mean volume of irrigation solution, 26 L (range, 12 to 39 L); mean systolic blood pressure, 97 mm Hg; mean diastolic blood pressure, 51 mm Hg; and mean surgical time, 110 minutes. A decrease in core body temperature by 0.5°C (0.9°F) or greater occurred during the course of surgery in 66% of patients in the control group versus 28% in the warmed-solution group (P < .001). At least 1 core body temperature measurement of less than 36°C (96.8°F) was recorded in 48% of patients in the control group versus 14% in the warmed-solution group (P < .001). The trend toward a decrease in core body temperature was 4 times greater in the control group than in the warmed-solution group (P < .001).

CONCLUSIONS

Use of arthroscopic irrigation solution warmed up to 32°C (89.6°F) reduces the risk of a decrease in core body temperature during hip arthroscopy in patients with femoroacetabular impingement.

LEVEL OF EVIDENCE

Level II, analytical, prospective, comparative study in a cohort of consecutive patients.

Hip anatomic variants that may mimic abnormalities at MRI: labral variants

OBJECTIVE

Normal anatomic variants of the acetabular labrum are observed on MR images and include labral variants, several sublabral sulci, and perilabral sulcus. Because variants can be misidentified as labral abnormalities such as labral tears, the radiologist needs to avoid the pitfall of mistaking variants as abnormalities.

CONCLUSION

The hip has multiple anatomic variants that can mimic abnormalities at hip MRI. The labrum has several anatomic variants that can be confused with true labral tears.