Acetabular labral tears in the athlete

Is bone marrow oedema in patients with labral tear an indicator of hip pain?

Background

Hip labral tear (LT) causes various degrees of hip pain, for which there are few objective measures. Bone marrow oedema (BME), characterized by a diffuse, widely spreading change in the bone marrow, is observed in some patients with LT. However, its pathological role has not been fully understood. The purpose of this study was to investigate the prevalence of BME on hip magnetic resonance imaging (MRI) in patients with LT and to determine whether BME was an objective indicator of hip pain.

Methods

In total, 84 patients with LT who underwent MRI scanning under the same conditions were included. We determined the presence or absence of BME and its size on MRI and evaluated the relationships between BME and sex, age, and pain and total scores on the modified Harris hip score (MHHS). In addition, we collected data on surgical treatments such as hip arthroscopy within a one-year follow-up period and examined whether the presence of BME affected the course of therapy.

Results

BME was found in 34.5% of patients. MHHS pain and total scores were significantly lower in patients with BME (MHHS pain score: non-BME vs. BME ≤ 1 cm: p = 0.022, non-BME vs. BME > 1 cm: p < 0.001; MHHS total score: non-BME vs. BME ≤ 1 cm: p = 0.131, non-BME vs. BME > 1 cm: p = 0.027). The presence of BME did not differ between patients who did and did not undergo surgery during follow-up (p = 0.563).

Conclusion

BME on MRI in patients with LT might be an indicator of hip pain and hip joint dysfunction.

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.

Proximal femoral epiphyseal spurs and their association with acetabular labral tears on MRI in symptomatic patients

OBJECTIVE

Femoral epiphyseal spurs are developmental projections that form at the edge of the physis. Although considered incidental, their association with acetabular labral tears has never been examined. Our aim was to assess the prevalence of femoral epiphyseal spurs in symptomatic patients with mechanical hip pain and explore if they are associated with labral tears on MRI.

MATERIALS AND METHODS

Hip MRI scans performed on a Siemens 3 T MRI using femoroacetabular impingement protocol were retrospectively reviewed. All patients were referred by orthopaedic surgeons for mechanical hip pain. Two musculoskeletal radiologists blinded to initial reports evaluated MRI images for the presence of an epiphyseal spur and acetabular labral changes. A consensus was achieved on all cases by the two readers. The association between epiphyseal spurs and labral changes was assessed using Fisher's exact test.

RESULTS

A total of 115 patients (178 hip MRI scans) were reviewed; the mean age was 28.8 years (SD 7.1). There were 52 females (45.2%) and 63 males (54.8%). There were 115 hips with labral tears (64.6%). Fourteen hips (7.8%) in ten patients (8.7%) demonstrated epiphyseal spurs and all of them showed labral tears (100%). There was statistically significant association between epiphyseal spurs and labral tears on MRI (p value = 0.0024).

CONCLUSION

Femoral epiphyseal spurs were observed in 8.7% of our defined patient population, and all patients with epiphyseal spurs demonstrated labral tears. Epiphyseal spurs should be documented on imaging reports due to their potential association with labral tears. Future research is needed to further delineate and guide management of these entities.

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.

Rate of Surgery and Baseline Characteristics Associated With Surgery Progression in Young Athletes With Prearthritic Hip Disorders

Background:

Prearthritic hip disorders (PAHD), such as femoroacetabular impingement (FAI), acetabular dysplasia, and acetabular labral tears, are a common cause of pain and dysfunction in adolescent and young adult athletes, and optimal patient-specific treatment has not been defined. Operative management is often recommended, but conservative management may be a reasonable approach for some athletes.

Purpose:

To identify (1) the relative rate of progression to surgery in self-reported competitive athletes versus nonathletes with PAHD and (2) baseline demographic, pain, and functional differences between athletes who proceeded versus those who did not proceed to surgery within 1 year of evaluation.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

An electronic medical record review was performed of middle school, high school, and college patients who were evaluated for PAHD at a single tertiary-care academic medical center between June 22, 2015, and May 1, 2018. Extracted variables included patients’ self-reported athlete status, decision to choose surgery within 1 year of evaluation, and baseline self-reported pain and functional scores on Patient-Reported Outcomes Measurement Information System (PROMIS) domains, the Hip disability and Osteoarthritis Outcome Score (HOOS), and the modified Harris Hip Score.

Results:

Of 260 eligible patients (289 hips), 203 patients (78%; 227 hips) were athletes. Athletes were no more likely to choose surgery than nonathletes (130/227 hips [57%] vs 36/62 hips [58%]; relative risk [RR], 0.99 [95% CI, 0.78-1.25]). Among athletes, those who proceeded to surgery over conservative care were more likely to be female (81% vs 69%; RR, 1.34 [95% CI, 0.98-1.83]) and had more known imaging abnormalities (FAI: 82% vs 69%, RR, 1.47 [95% CI, 1.09-1.99]; dysplasia: 48% vs 27%, RR, 1.44 [95% CI, 1.16-1.79]; mixed deformity: 30% vs 10%, RR, 2.91 [95% CI, 1.53-5.54]; known labral tear: 84% vs 40%, RR, 2.79 [95% CI, 2.06-3.76]). Athletes who chose surgery also reported worse baseline hip-specific symptoms on all HOOS subscales (mean difference, 10.8-17.7; P < .01 for all).

Conclusion:

Similar to nonathletes, just over half of athletes with PAHD chose surgical management within 1 year of evaluation. Many competitive athletes with PAHD continued with conservative management and deferred surgery, but more structural hip pathology and worse hip-related baseline physical impairment were associated with the choice to pursue surgery.

ISHA-Richard Villar Best Clinical Paper Award: Acetabular labral tears in sexually active women: an evaluation of patient satisfaction following hip arthroscopy

The aim of this study was to evaluate the effect of symptomatic labral tears on the sex lives of women and the effect of surgical intervention on hip symptoms during sexual intercourse. One hundred and twenty consecutive women who had undergone hip arthroscopy under a single surgeon at a tertiary referral centre were identified. A specific questionnaire was designed and sent to each of the patients. Data were collected on the nature of symptoms, if they experienced any hip pain during sexual intercourse and if this had impacted on their sex lives and the degree of resolution of hip symptoms after the procedure, on a scale of 1-10. One hundred and four responses were available. Ninety-two women reported that they were sexually active. Of these, 87 (94%) reported pain during intercourse affecting their sex life. Eight women reported hip pain for a few days following intercourse and four stated that they are often not able to continue on account of the pain. Mean patient satisfaction with a resolution of symptoms during intercourse was 7.8 out of the 10. Seventy-seven women reported a post-operative improvement in the hip symptoms experienced during sex. Labral tears do have a significant effect on the sex life of women. Hip arthroscopy to address the labral tear as well as any underlying pathology relieves the pain experienced by women during intercourse with, a resultant improvement in their sex lives.

Nonoperative Management of Labral Tears of the Hip in Adolescent Athletes: Description of Sports Participation, Interventions, Comorbidity, and Outcomes

CONTEXT

Hip injury among young athletes is increasing, especially hip labral tears. Some tears may require surgical intervention, especially if they are associated with boney pathology such as femoroacetabular impingement (FAI). A protocol for nonoperative treatment of the hip labral tears is not well established.

OBJECTIVE

To identify current nonoperative treatment options, comorbidities, sports participation, and outcomes of adolescent athletes who were diagnosed with hip labral tears.

STUDY DESIGN

Retrospective chart review.

SETTING

A regional tertiary level medical and academic institution.

PARTICIPANTS

Physically active 8- to 20-year-old males and females who were diagnosed with hip labral tears in 2010 to 2013.

MAIN OUTCOME MEASURES

Nonoperative treatment interventions including physical therapy (PT), intraarticular injection (IAI), the type of sports participation, and comorbidity were extracted.

STATISTICAL ANALYSIS

Descriptive statistics and χ tests were used with a priori alpha level <0.05.

RESULTS

Among 76 adolescent athletes who were diagnosed with hip labral tear, 52 (68.4%) had PT, 55 (72.4%) received IAI, and 43 (56.6%) experienced both PT and IAI interventions. Top 3 sports participated were dance (18.4%), soccer (14.5%), and gymnastics (7.9%). The most common comorbidity was FAI, which was observed in 46 individuals (60.5%). Although there was no difference in a proportion of FAI cases between sexes, a greater proportion of surgical cases were observed among hip labrum-injured athletes with FAI compared with those without FAI (P = 0.032).

CONCLUSIONS

Adolescent athletes with hip labral tears often receive PT, IAI, and a combination of both, as nonoperative treatment options in this study cohort. The adolescent athletes who sustained hip labral tears with comorbidity of FAI had significantly greater proportion of surgical cases after nonoperative treatments.

Injuries of the adolescent girl athlete: a review of imaging findings

With the rising participation of girls in sports at both the recreational and elite levels, there has also been increased awareness of injuries common in this athlete population. Anatomic differences between boys and girls cause girl athletes to be predisposed to certain injuries. Certain behavioral patterns, such as eating disorders, also cause problems specific to girl athletes that may result in injury. Imaging plays a large role in diagnosis and ongoing management, but there has been only scant literature dedicated to the specific topic of imaging in girl athletes. The purpose of this article is to review the imaging findings and recommendations for injuries and other conditions affecting the adolescent girl athlete. This article first provides an overview of the key anatomic differences between boys and girls, including both static and dynamic factors, as well as non-anatomic differences, such as hormonal factors, and discusses how these differences contribute to the injury patterns that are seen more typically in girls. The article then reviews the imaging findings in injuries that are commonly seen in girl athletes. There is also a discussion of the "female athlete triad," which consists of osteoporosis, disordered eating, and amenorrhea, and the role of imaging in this condition.

Do Verbal and Tactile Cueing Selectively Alter Gluteus Maximus and Hamstring Recruitment During a Supine Bridging Exercise in Active Females? A Randomized Controlled Trial

Context: Hip extension with hamstring-dominant rather than gluteus maximus-dominant recruitment may increase anterior femoracetabular forces and contribute to conditions that cause hip pain. Cueing methods during hip extension exercises may facilitate greater gluteus maximus recruitment. Objective: We examined whether specific verbal and tactile cues facilitate gluteus maximus recruitment while inhibiting hamstring recruitment during a bridging exercise. Design: Randomized controlled trial. Setting: Biomechanics laboratory. Participants: 30 young adult women (age 24 [3] y; BMI 22.2 [2.4] kg/m2). Intervention: Participants were tested over 2 sessions, 1 week apart, while performing 5 repetitions of a bridging exercise. At their second visit, participants in the experimental group received verbal and tactile cues intended to facilitate gluteus maximus recruitment and inhibit hamstring recruitment. Control group participants received no additional cues beyond original instructions. Main Outcome Measures: Gluteus maximus and hamstring recruitment were measured with surface electromyography, normalized to maximal voluntary isometric contractions (MVICs). Results: Gluteus maximus recruitment was unchanged in the control group and increased from 16.8 to 33.0% MVIC in the cueing group (F = 33.369, P < .001). Hamstring recruitment was unchanged in the control group but also increased from 16.5 to 29.8% MVIC in the cueing group (F = 6.400, P = .02). The effect size of the change in gluteus maximus recruitment in the cueing group (Cohen’s d = 1.5, 95% CI = 0.9 to 2.2) was not significantly greater than the effect size in hamstring recruitment (Cohen’s d = 0.8, 95% CI = 0.1 to 1.5). Conclusions: Verbal and tactile cues hypothesized to facilitate gluteus maximus recruitment yielded comparable increases in both gluteus maximus and hamstring recruitment. If one intends to promote hip extension by facilitating gluteus maximus recruitment while inhibiting hamstring recruitment during bridging exercises, the cueing methods employed in this study may not produce desired effects.

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.

Similar Prevalence of Acetabular Labral Tear in Professional Ballet Dancers and Sporting Participants

OBJECTIVE

To compare the prevalence of acetabular labral tear in male and female professional ballet dancers with age-matched and sex-matched sporting participants and to determine the relationship to clinical findings and cartilage defects.

DESIGN

Case-control study.

SETTING

Clinical and radiology practices.

PARTICIPANTS

Forty-nine (98 hips) male and female professional ballet dancers (current and retired) with median age 30 years (range: 19-64 years) and 49 (98 hips) age-matched and sex-matched sporting participants.

INDEPENDENT VARIABLES

Group (ballet or sports), sex, age, hip cartilage defects, history of hip pain, Hip and Groin Outcome Score, passive hip internal rotation (IR), and external rotation range of movement (ROM).

MAIN OUTCOME MEASURES

Labral tear identified with 3T magnetic resonance imaging (MRI).

RESULTS

Labral tears were identified in 51% of all 196 hips. The prevalence did not differ significantly between the ballet and sporting participants (P = 0.41) or between sexes (P = 0.34). Labral tear was not significantly associated with clinical measures, such as pain and function scores or rotation ROM (P > 0.01 for all). Pain provocation test using IR at 90° of hip flexion had excellent specificity [96%, 95% confidence intervals (CIs), 0.77%-0.998%] but poor sensitivity (50%, 95% CI, 0.26%-0.74%) for identifying labral tear in participants reporting hip pain. Older age and cartilage defect presence were independently associated with an increased risk of labral tear (both P < 0.001).

CONCLUSIONS

The prevalence of labral tear in male and female professional ballet dancers was similar to a sporting population. Labral tears were not associated with clinical findings but were related to cartilage defects, independent of aging.

CLINICAL RELEVANCE

Caution is required when interpreting MRI findings as labral tear may not be the source of the ballet dancer's symptoms.

Hip morphology in elite golfers: asymmetry between lead and trail hips

Aim

During a golf swing, the lead hip (left hip in a right-handed player) rotates rapidly from external to internal rotation, while the opposite occurs in the trail hip. This study assessed the morphology and pathology of golfers’ hips comparing lead and trail hips.

Methods

A cohort of elite golfers were invited to undergo MRI of their hips. Hip morphology was evaluated by measuring acetabular depth (pincer shape=negative measure), femoral neck antetorsion (retrotorsion=negative measure) and α angles (cam morphology defined as α angle >55° anteriorly) around the axis of the femoral neck. Consultant musculoskeletal radiologists determined the presence of intra-articular pathology.

Results

55 players (mean age 28 years, 52 left hip lead) underwent MRI. No player had pincer morphology, 2 (3.6%) had femoral retrotorsion and 9 (16%) had cam morphology. 7 trail hips and 2 lead hips had cam morphology (p=0.026). Lead hip femoral neck antetorsion was 16.7° compared with 13.0° in the trail hip (p<0.001). The α angles around the femoral neck were significantly lower in the lead compared with trail hips (p<0.001), with the greatest difference noted in the anterosuperior portion of the head neck junction; 53° vs 58° (p<0.001) and 43° vs 47° (p<0.001). 37% of trail and 16% of lead hips (p=0.038) had labral tears.

Conclusions

Golfers’ lead and trail hips have different morphology. This is the first time side-to-side asymmetry of cam prevalence has been reported. The trail hip exhibited a higher prevalence of labral tears.

Effect of posture on hip angles and moments during gait

Anterior hip pain is common in young, active adults. Clinically, we have noted that patients with anterior hip pain often walk in a swayback posture, and that their pain is reduced when the posture is corrected. The purpose of this study was to investigate a potential mechanism for the reduction in pain by testing the effect of posture on movement patterns and internal moments during gait in healthy subjects. Fifteen subjects were instructed to walk while maintaining three postures: 1) natural, 2) swayback, and 3) forward flexed. Kinematic and force data were collected using a motion capture system and a force plate. Walking in the swayback posture resulted in a higher peak hip extension angle, hip flexor moment and hip flexion angular impulse compared to natural posture. In contrast, walking in a forward flexed posture resulted in a decreased hip extension angle and decreased hip flexion angular impulse. Based on these results, walking in a swayback posture may result in increased forces required of the anterior hip structures, potentially contributing to anterior hip pain. This study provides a potential biomechanical mechanism for clinical observations that posture correction in patients with hip pain is beneficial.

Effect of increased pushoff during gait on hip joint forces

Anterior acetabular labral tears and anterior hip pain may result from high anteriorly directed forces from the femur on the acetabulum. While providing more pushoff is known to decrease sagittal plane hip moments, it is unknown if this gait modification also decreases hip joint forces. The purpose of this study was to determine if increasing pushoff decreases hip joint forces. Nine healthy subjects walked on an instrumented force treadmill at 1.25 m/s under two walking conditions. For the natural condition, subjects were instructed to walk as they normally would. For the increased pushoff condition, subjects were instructed to "push more with your foot when you walk". We collected motion data of markers placed on the subjects' trunk and lower extremities to capture trunk and leg kinematics and ground reaction force data to determine joint moments. Data were processed in Visual3D to produce the inverse kinematics and model scaling files. In OpenSim, the generic gait model (Gait2392) was scaled to the subject, and hip joint forces were calculated for the femur on the acetabulum after computing the muscle activations necessary to reproduce the experimental data. The instruction to "push more with your foot when you walk" reduced the maximum hip flexion and extension moment compared to the natural condition. The average reduction in the hip joint forces were 12.5%, 3.2% and 9.6% in the anterior, superior and medial directions respectively and 2.3% for the net resultant force. Increasing pushoff may be an effective gait modification for people with anterior hip pain.

[Femoroacetabular impingement in athletes: pathology, diagnostics and operative therapy options]

Femoroacetabular impingement (FAI) and its therapy has gained importance in the last decade and several studies could show that if untreated it may lead to osteoarthritis of the hip joint. In this article an overview of the pathology of FAI, the diagnosis and treatment options are presented. A closer look is taken at the treatment of elite athletes regarding the different techniques. The first own clinical and radiological results of 91 patients treated by the arthroscopically-assisted anterior mini-open approach are presented with very good results and significant postoperative improvement regarding the hip injury and osteoarthritis outcome score (HOOS), the Western Ontario and McMasters University (WOMAC) osteoarthritis index and the University of California Los Angeles (UCLA) activity score, as well as alpha angle correction. This technique which is poorly represented in the literature can be used as a treatment option for FAI. The rehabilitation program is comparable to hip arthroscopy.

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.

Radiographic findings of femoroacetabular impingement in capoeira players

PURPOSE

Capoeira is a Brazilian martial art that requires extreme movements of the hip to perform jumps and kicks. This study evaluated a group of capoeira players to assess the prevalence of femoroacetabular impingement (FAI) in athletes practicing this martial art.

METHODS

Twenty-four experienced capoeira players (14 men, 10 women) underwent a diagnostic assessment, including clinical examination and standard radiographs of the pelvis and hips. The α-angle, head-neck offset, crossover sign, acetabular index, lateral centre-edge angle, and the Tönnis grade were assessed using the radiographs. Clinical relationships for any radiographic abnormalities indicating FAI were also evaluated.

RESULTS

Four subjects (17 %) reported pain in their hips. Forty-four hips (91.7 %) had at least one radiographic sign of CAM impingement, and 22 (45.8 %) had an α-angle of more than 60°. Eighteen hips (37.5 %) had at least one sign of pincer impingement and 16 (33.3 %) a positive crossover sign. Sixteen hips (33.3 %) had mixed impingement. There was a significant positive association between having an α-angle of more than 60° and the presence of groin pain (P = 0.002). A reduced femoral head-neck offset (P < 0.001) and an increased α-angle on the anteroposterior radiograph (P = 0.008) were independently associated with a higher Tönnis grade.

CONCLUSION

High prevalence of radiographic CAM-type FAI among these skilled capoeira players was found. In these subjects, a negative clinical correlation for an increased α-angle was also detected. Additional caution should be exercised whenever subjects with past or present hip pain engage in capoeira.

Femoroacetabular impingement: fact, fiction, or fantasy?

OBJECTIVE

Proponents of femoroacetabular impingement (FAI) now claim that FAI is an important risk factor for hip osteoarthritis and argue that early, aggressive treatment is indicated to stave off long-term complications. The result is more young patients undergoing corrective surgery; does the literature support these claims or has hype trumped reality? This article critically reviews these assertions together with the current scientific evidence that defends (or refutes) them.

CONCLUSION

Each reader will need to weigh the evidence carefully when interpreting images or planning management for patients with possible FAI.

Emerging intra-articular causes of groin pain in athletes

Groin pain remains one of the most poorly understood conditions in clinical sports medicine. It may be caused by either extra-articular or intra-articular conditions. While extra-articular causes have been extensively studied and reasonably understood, a number of elusive intra-articular causes are emerging, many of which were previously unknown and therefore undiagnosed, leading to premature ending of many competitive careers. This article makes an attempt to look at various, elusive intra-articular causes of groin pain in athletes. This article also analyses the currently available evidence on trends in diagnosis and treatment for these conditions.

The hip antero-superior labral tear with avulsion of rectus femoris (HALTAR) lesion: does the SLAP equivalent in the hip exist?

BACKGROUND

The purpose of this report is to describe a new lesion, the "Hip Antero-superior Labral Tear with Avulsion of Rectus femoris (HALTAR)". This injury may be seen in both adolescent and skeletally mature athletes and shares several characteristics with the "Superior Labral tear from Anterior to Posterior (SLAP)" lesion in the shoulder.

METHODS

We present a case example, as well as a detailed anatomic description of the pathological condition.

RESULTS

As the rectus femoris crosses two joints it is exposed to substantial forces during muscle contraction. Considering the peri-articular origin of the reflected head at the superior aspect of the acetabular rim, a powerful eccentric contraction of the rectus femoris muscle or traction related to sudden knee flexion may cause an avulsion injury of the rectus femoris as well as a concomitant labral tear.

CONCLUSIONS

A strain injury of the rectus femoris muscle, which is common in young athletic patients, may cause a concomitant tear of the acetabular labrum. Therefore, we recommend further diagnostic work-up in cases with prolonged hip pain and impaired hip function following an AIIS injury in order to identify any associated peri- and intra-articular damage. In our experience these patients seldom need aggressive surgical management.

Surgical dislocation of the hip: evolving indications

BACKGROUND

Femoroacetabular impingement (FAI) is a condition that has become increasingly identified as abnormal, repetitive abutment of the proximal femur and acetabular rim. Safe surgical dislocation of the hip has been popularized as a technique that allows surgeons to not only improve joint preservation procedures but also understand disease patterns more clearly.

QUESTIONS/PURPOSES

We describe the technique of surgical dislocation as well as review the indications, results, and complications that are associated with the procedure. We also present various case examples to highlight this technique.

SEARCH STRATEGIES

We performed a systematic review of the literature to define the indications, clinical outcomes, and complications associated with surgical dislocation of the hip for the treatment of FAI.

RESULTS

Clinical success rates vary in the literature between 64% and 96% of patients with good results, and conversion to total hip arthroplasty ranging between 0% and 30% in patients who underwent FAI treatment with surgical dislocation. Reported major complication rates have ranged from 3.3% to 6%, most commonly in the form of trochanteric nonunion, neurapraxia, or heterotopic ossification.

CONCLUSIONS

FAI deformities encompass a wide spectrum of disease patterns. Surgical dislocation allows full access to the hip in addition to observing its pathomechanics. Strict adherence to proper technique allows the surgeon to minimize complication rates while treating the deformity at hand.

Acetabular rim lesions: arthroscopic assessment and clinical relevance

PURPOSE

The purpose of this study was to investigate whether acetabular morphology may influence both pathogenesis and prognosis of the acetabular rim lesions and to propose a new system to classify labral tears.

METHODS

We assessed radiographic and arthroscopic findings in 81 patients (40 male and 41 female patients, 86 hips) aged from 16 to 74 years (median, 31 years) who underwent hip arthroscopy.

RESULTS

Acetabular rim lesions were associated with four different hip morphologies. Eleven (32 %) of 34 patients with severe rim lesions underwent hip arthroplasty for progressive symptoms, whereas no patient with early rim lesion reported significant progression of symptoms. The strategy of treatment was changed in 33 % of the patients undergoing arthroscopy before undertaking peri-acetabular osteotomy.

CONCLUSIONS

Hip arthroscopy avoids more invasive procedures in patients with early acetabular rim lesions.

Identification of acetabular labral pathological changes in asymptomatic volunteers using optimized, noncontrast 1.5-T magnetic resonance imaging

BACKGROUND

Acetabular labral tears as a source of potential hip pain have received a great deal of attention in recent literature. The gold standard for identifying acetabular labral tears is hip arthroscopy, but recent advances in optimized, noncontrast magnetic resonance imaging (MRI) have proven effectiveness in identifying intra-articular hip pathological changes without the invasive nature of hip arthroscopy or gadolinium-enhanced arthrography. There are little data in the literature on imaging results in an asymptomatic population.

PURPOSE

The objective of this study was to use an optimized, noncontrast 1.5-T MRI protocol to identify hip abnormalities, including paralabral cysts, in asymptomatic volunteers.

STUDY DESIGN

Case series (prevalence); Level of evidence, 4.

METHODS

In this study, 42 hips in asymptomatic patients with an average age of 34 years (range, 27-43 years) were prospectively imaged with optimized, noncontrast 1.5-T MRI scans. Two fellowship-trained musculoskeletal radiologists interpreted the scans at 2 different points in time and commented on the presence of labral abnormalities including paralabral cysts. The results were analyzed for both interobserver and intraobserver reliability.

RESULTS

Acetabular paralabral cysts were identified in 11 of 42 (26.2%) and 9 of 42 (21.4%) hips by the 2 respective radiologists, with an interobserver reliability of 90.5% (κ = .74) and intraobserver reliability of 95.2% (κ = .87). In addition, acetabular labral tears were identified in 36 of 42 (85.7%) and 34 of 42 (80.9%) hips, with an interobserver reliability of 90.5% (κ = .70) and intraobserver reliability of 95.2% (κ = .83).

CONCLUSION

Utilizing an optimized, noncontrast 1.5-T MRI protocol, we report the previously undescribed prevalence of acetabular labral pathological abnormalities and paralabral cysts in a young, asymptomatic population. This emphasizes the importance of correlating patient symptoms with history and physical examination when evaluating patients with hip pain and radiographic abnormalities as defined by MRI criteria. These data demonstrate that labral tears can occur without symptoms.

MR arthrographic appearance of the postoperative acetabular labrum in patients with suspected recurrent labral tears

OBJECTIVE

The objective of our study was to evaluate the MR arthrographic appearance of the acetabular labrum in patients with a suspected recurrent acetabular labral tear after previous arthroscopic resection of a labral tear.

CONCLUSION

The labrum after excision will appear shortened on MR arthrography. A recurrent labral tear can be diagnosed by the identification on MR arthrography of a new line to the labral surface, an enlarged and distorted labrum, or a new paralabral cyst.

Concurrent criterion-related validity of physical examination tests for hip labral lesions: a systematic review

Hip injuries are prevalent, especially within the athletic population. Of the hip injuries in this population, some 18-55% are lesions to the labrum of the hip. Clinical diagnosis of hip labral lesions is difficult because data on prevalence are varied. In addition, data on the prevalence of internal and external risk factors are absent as are data on the correlation of these risk factors with labral lesions, making it difficult to gauge the diagnostic utility. The mechanism of injury is often unknown or not specific to labral lesions. Internal risk factors may remain hidden to physical therapists because in most jurisdictions, ordering imaging tests is not within their scope of practice. Anterior inguinal pain seems highly sensitive for the diagnosis of patients with labral lesions but can hardly be considered specific; data on other pain-related and mechanical symptoms clearly have little diagnostic utility, making these data collected during the patient history almost irrelevant to diagnosis. By way of a comprehensive literature review and narrative and systematic analysis of the methodological quality of the retrieved diagnostic utility studies, this paper aimed to determine a diagnostic physical examination test or test cluster based on current best evidence for the diagnosis of hip labral lesions. Current best evidence indicates that a negative finding for the flexion-adduction-internal rotation test, the flexion-internal rotation test, the impingement provocation test, the flexion-adduction-axial compression test, the Fitzgerald test, or a combination of these tests provides the clinician with the greatest evidence-based confidence that a hip labral lesion is absent. Currently, research has produced no tests with sufficient specificity to help confidently rule in a diagnosis of hip labral lesion. Suggestions for future research are provided.

Current concepts in the diagnosis and management of femoroacetabular impingement

Femoroacetabular impingement is becoming increasingly recognised as a cause of hip pain in the young adult. It is thought that the condition may lead to acetabular labral tears, chondro-labral separation, chondral delamination and eventually predispose to osteoarthritis of the hip. Efforts have thus been directed to diagnosing and treating the underlying pathology and subsequent sequelae. This article presents the relevant literature with regards to the aetiology of femoroacetabular impingement, its clinical features, investigations and options of management. Finally outcomes relating to both open and arthroscopic approaches to treatment are discussed.

Hip instability

Understanding of the etiology and pathology of hip instability has increased in recent years as new information has emerged regarding the disease processes of the hip. Hip instability, heretofore considered uncommon in clinical practice, is increasingly recognized as a pathologic entity. Instability may be classified as traumatic or atraumatic, and diagnosis is made based on patient history, physical examination, and imaging studies. Plain radiography, MRI, MRI arthrography, and hip instability tests (eg, posterior impingement, dial) can be used to confirm the presence of instability. Nonsurgical management options include physical therapy and protected weight bearing. Surgical intervention, whether arthroscopic or open, is required for large acetabular fractures and refractory instability. Knowledge of the etiology and evolving research of hip instability is essential to understand the spectrum of hip disease.

Assessment of congruence and impingement of the hip joint in professional ballet dancers: a motion capture study

BACKGROUND

Early hip osteoarthritis in dancers could be explained by femoroacetabular impingements. However, there is a lack of validated noninvasive methods and dynamic studies to ascertain impingement during motion. Moreover, it is unknown whether the femoral head and acetabulum are congruent in typical dancing positions.

HYPOTHESIS

The practice of some dancing movements could cause a loss of hip joint congruence and recurrent impingements, which could lead to early osteoarthritis.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Eleven pairs of female dancer's hips were motion captured with an optical tracking system while performing 6 different dancing movements. The resulting computed motions were applied to patient-specific hip joint 3-dimensional models based on magnetic resonance images. While visualizing the dancer's hip in motion, the authors detected impingements using computer-assisted techniques. The range of motion and congruence of the hip joint were also quantified in those 6 recorded dancing movements.

RESULTS

The frequency of impingement and subluxation varied with the type of movement. Four dancing movements (développé à la seconde, grand écart facial, grand écart latéral, and grand plié) seem to induce significant stress in the hip joint, according to the observed high frequency of impingement and amount of subluxation. The femoroacetabular translations were high (range, 0.93 to 6.35 mm). For almost all movements, the computed zones of impingement were mainly located in the superior or posterosuperior quadrant of the acetabulum, which was relevant with respect to radiologically diagnosed damaged zones in the labrum. All dancers' hips were morphologically normal.

CONCLUSION

Impingements and subluxations are frequently observed in typical ballet movements, causing cartilage hypercompression. These movements should be limited in frequency.

CLINICAL RELEVANCE

The present study indicates that some dancing movements could damage the hip joint, which could lead to early osteoarthritis.

Invariant hip moment pattern while walking with a robotic hip exoskeleton

Robotic lower limb exoskeletons hold significant potential for gait assistance and rehabilitation; however, we have a limited understanding of how people adapt to walking with robotic devices. The purpose of this study was to test the hypothesis that people reduce net muscle moments about their joints when robotic assistance is provided. This reduction in muscle moment results in a total joint moment (muscle plus exoskeleton) that is the same as the moment without the robotic assistance despite potential differences in joint angles. To test this hypothesis, eight healthy subjects trained with the robotic hip exoskeleton while walking on a force-measuring treadmill. The exoskeleton provided hip flexion assistance from approximately 33% to 53% of the gait cycle. We calculated the root mean squared difference (RMSD) between the average of data from the last 15 min of the powered condition and the unpowered condition. After completing three 30-min training sessions, the hip exoskeleton provided 27% of the total peak hip flexion moment during gait. Despite this substantial contribution from the exoskeleton, subjects walked with a total hip moment pattern (muscle plus exoskeleton) that was almost identical and more similar to the unpowered condition than the hip angle pattern (hip moment RMSD 0.027, angle RMSD 0.134, p<0.001). The angle and moment RMSD were not different for the knee and ankle joints. These findings support the concept that people adopt walking patterns with similar joint moment patterns despite differences in hip joint angles for a given walking speed.

The female athlete

Over time, women have become more extensively involved in athletic programs. The female athlete presents a unique challenge to sports medicine in general. Although specific types of injuries are the same as in the male athlete, the female athlete is at higher risk for some of these injuries. Injuries may be sport specific, but gender-related injuries are also related to morphologic and physiologic differences between the male and female athlete. This article reviews some of the differences between the male and female athlete and focuses on a few prominent injuries or risks related specifically to the woman athlete.

Muscle activation and movement patterns during prone hip extension exercise in women

CONTEXT

The consistency of muscle activation order during prone hip extension has been debated.

OBJECTIVE

To investigate whether women use a consistent and distinguishable muscle activation order when extending the hip while prone and to explore the effects of verbal cues on muscle activation and movement.

DESIGN

Single-session, repeated-measures design.

SETTING

University laboratory.

PATIENTS OR OTHER PARTICIPANTS

Eleven healthy women (age = 27.7 +/- 6.2 years [range, 22-37 years]).

INTERVENTION(S)

We tested the participants under 3 conditions: no cues, cues to contract the gluteal muscles, and cues to contract the hamstrings muscles.

MAIN OUTCOME MEASURE(S)

We measured hip and knee angle and electromyographic data from the gluteus maximus, medial hamstrings, and lateral hamstrings while participants performed prone hip extension from 30 degrees of hip flexion to neutral.

RESULTS

When not given cues, participants used the consistent and distinguishable muscle activation order of medial hamstrings, followed by lateral hamstrings, then gluteus maximus (195.5 +/- 74.9, 100.2 +/- 70.3, and 11.5 +/- 81.9 milliseconds preceding start of movement, respectively). Compared with the no-cues condition, the gluteal-cues condition resulted in nearly simultaneous onset of medial hamstrings, lateral hamstrings, and gluteus maximus (131.3 +/- 84.0, 38.8 +/- 96.9, and 45.1 +/- 93.4 milliseconds, respectively) (P > .059); decreased activation of the medial hamstrings (P < .03) and lateral hamstrings (P < .024) around the initiation of movement; increased activation of gluteus maximus throughout the movement (P < .001); and decreased knee flexion (P = .002). Compared with the no-cues condition, the hamstrings-cues condition resulted in decreased activation of the medial hamstrings just after the initiation of movement (P = .028) and throughout the movement (P = .034) and resulted in decreased knee flexion (P = .003).

CONCLUSIONS

Our results support the contention that the muscle activation order during prone hip extension is consistent in healthy women and demonstrates that muscle timing and activation amplitude and movement can be modified with verbal cues. This information is important for clinicians using prone hip extension as either an evaluation tool or a rehabilitation exercise.

Arthroscopic labral reconstruction in the hip using iliotibial band autograft: technique and early outcomes

PURPOSE

The purpose of this study was to investigate the indications for and outcomes of arthroscopic labral reconstruction in the hip by use of iliotibial band (ITB) autograft.

METHODS

Between August 2005 and May 2008, the senior author (M.J.P.) performed 95 arthroscopic labral reconstructions using an ITB autograft in patients with advanced labral degeneration or deficiency. There were 47 patients who had undergone surgery at a minimum of 1 year previously and met the inclusion criteria. The modified Harris Hip Score (MHHS) and patient satisfaction were used to measure outcomes postoperatively. The labral autograft was harvested from the ITB through a separate incision. The graft was sutured to the intact labral remnant in the region of labral deficiency, re-establishing the suction seal of the hip joint.

RESULTS

There were 32 men and 15 women. The mean age at the time of surgery was 37 years (range, 18 to 55 years). The mean time from the onset of symptoms to labral reconstruction was 36 months (range, 1 month to 12 years). Subsequent total hip arthroplasty was performed in 4 patients (9%). Follow-up was obtained in 37 of the remaining 43 patients. The mean time to follow-up was 18 months (range, 12 to 32 months). The mean MHHS improved from 62 (range, 35 to 92) preoperatively to 85 (range, 53 to 100) postoperatively (P = .001). Median patient satisfaction was 8 out of 10 (range, 1 to 10). Patients who were treated within 1 year of injury had higher MHHSs than patients who waited longer than 1 year (93 v 81, P = .03). The independent predictor of patient satisfaction with outcome after labral reconstruction was age.

CONCLUSIONS

This study showed that patients who have labral deficiency or advanced labral degeneration had good outcomes and high patient satisfaction after arthroscopic intervention with acetabular labral reconstruction. Lower satisfaction was associated with joint space narrowing and increased age. Patients who waited longer than 1 year from the time of injury to surgery had lower function at follow-up than those treated in the first year.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

An integrated platform for hip joint osteoarthritis analysis: design, implementation and results

PURPOSE

We present a software designed to improve hip joint osteoarthritis (OA) understanding using 3D anatomical models, magnetic resonance imaging (MRI) and motion capture.

METHODS

In addition to a standard static clinical evaluation (anamnesis, medical images examination), the software provides a dynamic assessment of the hip joint. The operator can compute automatically and in real-time the hip joint kinematics from optical motion capture data. From the estimated motion, the software allows for the calculation of the active range of motion, the congruency and the center of rotation of the hip joint and the detection and localization of the femoroacetabular impingement region. All these measurements cannot be performed clinically. Moreover, to improve the subjective reading of medical images, the software provides a set of 3D measurement tools based on MRI and 3D anatomical models to assist and improve the analysis of hip morphological abnormalities. Finally, the software is driven by a medical ontology to support data storage, processing and analysis.

RESULTS

We performed an in vivo assessment of the software in a clinical study conducted with 30 professional ballet dancers, a population who are at high risk of developing OA. We studied the causes of OA in this selected population. Our results show that extreme motion exposes the morphologically "normal" dancer's hip to recurrent superior or posterosuperior FAI and to joint subluxation.

CONCLUSION

Our new hip software includes all the required materials and knowledge (images data, 3D models, motion, morphological measurements, etc.) to improve orthopedists' performances in hip joint OA analysis.

Prognostic value of chondral defects on the outcome after arthroscopic treatment of acetabular labral tears

Pathology of the acetabular labrum plays an increasing role in the treatment of hip pain. Hip arthroscopy has proven its clinical value as a useful procedure for successful treatment of labral tears. Until today, only a few studies have investigated the influence of articular cartilage defects on the clinical outcome of partial arthroscopic labrum resection in a larger patient population. We prospectively evaluated patients with an intraoperatively proven labral lesion/tear without any radiological and arthroscopical sign of a concomitant bony femoroacetabular impingement or hip dysplasia for a minimum postoperative follow-up of 2 years. Cartilage defects were classified according to Outerbridge and divided into two subgroups: Outerbridge < or = 1 and Outerbridge > or = 2, respectively. To evaluate combined results, various established scoring systems (visual analogue scale, modified Harris Hip Score, Larson Hip Score) were used. Out of 54 originally enrolled patients, 50 individuals (29 female, 21 male) with a median age of 33 years (range 15-49) were available for follow-up after a mean of 34 (range 24-48) months. At follow-up, the total study population experienced significant improvement in pain and in the combined evaluation scales (Larson Hip Score/MHHS). When patients were categorized into two subgroups, either with intraoperatively present or absent articular cartilage defects, our data indicated that subjects with no degenerative changes of the articular cartilage surface significantly improved in the applied clinically scoring systems. In contrast, in patients with an articular cartilage lesion during hip arthroscopy score values had a tendency to be unimproved or even deteriorated at follow-up. Regression analysis revealed a significant negative correlation between postoperative outcome and the grading of the coexistent articular cartilage defect. On the basis of our investigation, we conclude that partial arthroscopic resection of a torn labrum without attending bone deformity (dysplasia or femoroacetabular impingement) can reveal good and satisfied results. Depending on the extent of a coexisting articular cartilage defect subjective clinical results are compromised.

A comprehensive review of hip labral tears

The hip labrum has many functions, including shock absorption, joint lubrication, pressure distribution, and aiding in stability, with damage to the labrum associated with osteoarthritis. The etiology of labral tears includes trauma, femoroacetabular impingement (FAI), capsular laxity/hip hypermobility, dysplasia, and degeneration. Labral tears present with anterior hip or groin pain, and less commonly buttock pain. Frequently, there are also mechanical symptoms including clicking, locking, and giving way. The most consistent physical examination finding is a positive anterior hip impingement test. Because of the vast differential diagnosis and the need for specialized diagnostic tools, labral tears frequently go undiagnosed during an extended period of time. Evaluation usually begins with plain radiographs to assess for dysplasia, degeneration, and other causes of pain. While magnetic resonance imaging (MRI) and computed tomography scans are unreliable for diagnosis, magnetic resonance arthrography (MRA) is the diagnostic test of choice, with arthroscopy being the gold standard. Typically, treatment begins conservatively with relative rest and non-steroid anti-inflammatory agents, with physical therapy (PT) being controversial. Often, surgical treatment is necessary, which entails, arthroscopic debridement of labral tears and surgical repair of associated structural problems.

The 23-point arthroscopic examination of the hip: basic setup, portal placement, and surgical technique

The 23-point arthroscopic examination of the hip has been used for more than 400 arthroscopic hip procedures. It ensures that all components of the hip are carefully inspected and allows for proper documentation. It is vital that a precise knowledge of hip anatomy and common portal placement is coupled with proper patient selection, sound preoperative planning, and a consistent arthroscopic technique in order to maximize clinical outcomes. The 23-point arthroscopic examination of the hip uses 3 standard portals (anterior, anterolateral, and posterolateral) that provide a systematic method of examination of the key structures of the central and peripheral hip joint. The points are divided up into groups based on the portal through which they are viewed. The 23-point arthroscopic examination of the hip is reproducible, and offers some standardization within the evolving field of hip arthroscopy. It provides a consistent routine for hip arthroscopy that has yet to be published. Using this standardized examination can assist with the diagnostic accuracy of hip arthroscopy.

Clinical presentation of patients with symptomatic anterior hip impingement

Femoroacetabular impingement (FAI) is considered a cause of labrochondral disease and secondary osteoarthritis. Nevertheless, the clinical syndrome associated with FAI is not fully characterized. We determined the clinical history, functional status, activity status, and physical examination findings that characterize FAI. We prospectively evaluated 51 patients (52 hips) with symptomatic FAI. Evaluation of the clinical history, physical exam, and previous treatments was performed. Patients completed demographic and validated hip questionnaires (Baecke et al., SF-12, Modified Harris hip, and UCLA activity score). The average patient age was 35 years and 57% were male. Symptom onset was commonly insidious (65%) and activity-related. Pain occurred predominantly in the groin (83%). The mean time from symptom onset to definitive diagnosis was 3.1 years. Patients were evaluated by an average 4.2 healthcare providers prior to diagnosis and inaccurate diagnoses were common. Thirteen percent had unsuccessful surgery at another anatomic site. On exam, 88% of the hips were painful with the anterior impingement test. Hip flexion and internal rotation in flexion were limited to an average 97 degrees and 9 degrees, respectively. The patients were relatively active, yet demonstrated restrictions of function and overall health. These data may facilitate diagnosis of this disorder.

Effect of position and alteration in synergist muscle force contribution on hip forces when performing hip strengthening exercises

BACKGROUND

Understanding the magnitude and direction of joint forces generated by hip strengthening exercises is essential for appropriate prescription and modification of these exercises. The purpose of this study was to evaluate hip joint forces created across a range of hip flexion and extension angles during two hip strengthening exercises: prone hip extension and supine hip flexion.

METHODS

A musculoskeletal model was used to estimate hip joint forces during simulated prone hip extension and supine hip flexion under a control condition and two altered synergist muscle force conditions. Decreased strength or activation of specific muscle groups was simulated by decreasing the modeled maximum force values by 50%. For prone hip extension, the gluteal muscle strength was decreased in one condition and the hamstring muscle strength in the second condition. For supine hip flexion, the strength of the iliacus and psoas muscles was decreased in one condition, and the rectus femoris, tensor fascia lata, and sartorius muscles in the second condition.

FINDINGS

The hip joint forces were affected by hip joint position and partially by alterations in muscle force contribution. For prone hip extension, the highest net resultant force occurred with the hip in extension and the gluteal muscles weakened. For supine hip flexion, the highest resultant forces occurred with the hip in extension and the iliacus and psoas muscles weakened.

INTERPRETATION

Clinicians can use this information to select exercises to provide appropriate prescription and pathology-specific modification of exercise.

Safe angle for suture anchor insertion during acetabular labral repair

PURPOSE

The purpose of this study was to define a safe angle for suture anchor insertion during acetabular labral repair that will facilitate anchor placement within bone and prevent penetration into the hip joint.

METHODS

Nine acetabuli were harvested. Anatomic measurements were performed at the anterosuperior quadrant. Electronic calipers were used to measure acetabular bone. "Safe angle" measurements were obtained with suture anchor drills and a protractor. Comparisons between groups were calculated with a 1-way analysis of variance. The Tukey post-hoc analysis was completed for all significant analysis of variance results.

RESULTS

Labral insertion point distances and acetabular bone widths at the labral insertion did not statistically differ. Mean "danger angles" ranged from 17.0 degrees to 23.8 degrees. Safe angle measurements ranged from 20.1 degrees to 27.6 degrees.

CONCLUSIONS

The extracapsular labral insertion, located between 2.3 and 2.6 mm from the rim of the anterosuperior acetabulum, is offered as a starting point for insertion of anchors sized less than 3.0 mm. The danger angle and safe angle of anchor insertion serve as guidelines that may improve fixation in bone and lessen intra-articular penetration. A target angle of 10 degrees is recommended.

CLINICAL RELEVANCE

The danger angle and safe angle may be referenced intraoperatively, during imaging and suture anchor insertion, to assure anchor placement within bone and prevent intra-articular penetration. A target angle of 10 degrees is safe and easily remembered.

Identification of abnormal hip motion associated with acetabular labral pathology

STUDY DESIGN

Resident's case problem.

BACKGROUND

Recent literature has suggested that acetabular labral pathology secondary to femoroacetabular impingement (FAI) may be a precursor to early-onset hip osteoarthritis. The purpose of this resident's case problem was to explore the extent to which abnormal movement at the hip is a possible contributor to acetabular labral pathology.

DIAGNOSIS

The patient was a 25-year-old female with a 4-year history of anterior-medial groin pain. Based on a combination of the clinical examination and magnetic resonance imaging findings, she was given a diagnosis of acetabular labral tear by her orthopaedic surgeon and referred to a physical therapist for assessment. Movement analysis during a single-leg step down, running, and a drop jump maneuver revealed excessive hip adduction and internal rotation on the involved side, which reproduced her symptoms. Application of a hip-strapping device resulted in decreased hip adduction and internal rotation, and an immediate decrease in symptoms.

DISCUSSION

The reduction in pain secondary to controlling hip motion suggests that excessive frontal and transverse plane hip motions may contribute to FAI. Accordingly, physical therapy intervention aimed at controlling and reducing hip adduction and internal rotation during activities may be indicated in patients who present with this movement pattern associated with anterior hip/groin pain.

Walking with increased ankle pushoff decreases hip muscle moments

In a simple bipedal walking model, an impulsive push along the trailing limb (similar to ankle plantar flexion) or a torque at the hip can power level walking. This suggests a tradeoff between ankle and hip muscle requirements during human gait. People with anterior hip pain may benefit from walking with increased ankle pushoff if it reduces hip muscle forces. The purpose of our study was to determine if simple instructions to alter ankle pushoff can modify gait dynamics and if resulting changes in ankle pushoff have an effect on hip muscle requirements during gait. We hypothesized that changes in ankle kinetics would be inversely related to hip muscle kinetics. Ten healthy subjects walked on a custom split-belt force-measuring treadmill at 1.25m/s. We recorded ground reaction forces and lower extremity kinematic data to calculate joint angles and internal muscle moments, powers and angular impulses. Subjects walked under three conditions: natural pushoff, decreased pushoff and increased pushoff. For the decreased pushoff condition, subjects were instructed to push less with their feet as they walked. Conversely, for the increased pushoff condition, subjects were instructed to push more with their feet. As predicted, walking with increased ankle pushoff resulted in lower peak hip flexion moment, power and angular impulse as well as lower peak hip extension moment and angular impulse (p<0.05). Our results emphasize the interchange between hip and ankle kinetics in human walking and suggest that increased ankle pushoff during gait may help to compensate for hip muscle weakness or injury and reduce hip joint forces.

Symptomatic labral tear post femoral shaft fracture: case report

Fracture of the femoral shaft is a common injury that is often treated with closed locked intramedullary nailing. Associated injuries such as ipsilateral femoral neck fracture, neurological or vascular compromise, and soft tissue injury of the knee are well known, but surprisingly little information exists regarding soft tissue injury of the hip in the setting of a femoral shaft fracture. In this case a 35-year-old man status-post closed femoral shaft fracture fixation was found to have a symptomatic ipsilateral labral tear and was successfully treated with arthroscopic debridement.

Acetabular labral tears of the hip in women

Acetabular labral tears are a major cause of hip dysfunction in young patients and a primary precursor to hip osteoarthritis. In addition, labral disease more commonly occurs in women and can present with nonspecific symptoms. It is possible to diagnose, quantify, and treat labral tears before the onset of secondary joint deterioration. However, the diagnosis requires a high index of suspicion, special attention to subtle patterns of presentation, and timely consideration for imaging studies. Treatment options are still evolving and include a wide array of nonsurgical and surgical techniques. Treatment should also address secondary dysfunction that can be associated with hip pathology. An initial trial of conservative management is recommended and failure to progress is an indication for surgical consultation.