Lower Extremity Injury Patterns in Elite Ballet Dancers: Ultrasound/MRI Imaging Features and an Institutional Overview of Therapeutic Ultrasound Guided Percutaneous Interventions

Little or No Differences in Hip Morphology Between Professional Dancers and Controls: A Systematic Review

OBJECTIVE

To systematically evaluate and synthesize the literature on bony hip morphology of professional dancers, as measured by 2D or 3D imaging techniques.

DATA SOURCES

A literature search was performed on November 20, 2020, using MEDLINE, Embase, and Cochrane. Clinical studies were eligible if they reported on hip morphology of professional dancers. Two independent reviewers screened titles, abstracts, and full-texts to determine eligibility; performed data extraction; and assessed the quality of eligible studies according to the Joanna Briggs Institute (JBI) checklist. This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines.

MAIN RESULTS

The search returned 1384 records; 449 were duplicates, 923 were excluded after title/abstract/full-text screening, and 12 were eligible, reporting on 447 individuals (352 professional dancers and 95 controls). The JBI checklist indicated that 11 studies scored ≥4 points. For professional dancers, lateral center edge angle was 22.4 to 30.8 degrees, acetabular version was 6.7 to 13.5 degrees, neck-shaft angle was 132.5 to 139.5 degrees, and femoral version was 4.7 to 14.4 degrees. Statistically significant differences between dancers and controls were found in some of the studies for acetabular version, neck-shaft angle, and femoral version, although only femoral version showed clinically relevant differences.

CONCLUSIONS

The bony hip morphology of professional dancers is similar to that of other athletes and age-matched controls, which is in contrast to the authors' clinical experience. We presume that the abnormal morphology we have seen at the clinic is only present in symptomatic dancers who require total hip arthroplasty (THA) and is not a general characteristic of all dancers. Further studies should compare the hip morphology of dancers undergoing THA with matched nondancers.

Spotty Bone Marrow: A Frequent MRI Finding in the Feet of Ballet Dancers

INTRODUCTION

Bone marrow signal abnormalities on magnetic resonance imaging (MRI) are common in athletes. However, few studies evaluate the MRI appearance of bone marrow in the feet of ballet dancers. Our study aims to describe the "spotty bone marrow" (SBM) pattern in the tarsal bones of a cohort of ballet dancers, establishing its prevalence, distribution, potential associations, and evolution.<br/> Methods: Eighty-six MRIs of 68 ankles in 56 ballet dancers were retrospectively reviewed for mar- row signal alterations, which were classified as focal or SBM (defined as patchy fluid-sensitive signal hyperintensity spanning more than one location or tarsal bone). When SBM involved the talus, its anatomic distribution in the bone and morphologic pattern were recorded. Additional osseous and soft tissue findings were documented. For subjects with more than one MRI of the same ankle, the SBM's evolution was monitored.<br/> Results: Spotty bone marrow was identified in 44 ankles (65%). Spotty bone marrow was isolated to the talus (44%), present in all tarsal bones (25%), or distributed between the talus and one to three other tarsal bones (31%). In the talus, The SBM involved the entire bone (65%), the neck and body (31%), or the head and neck (4%). The SBM most commonly showed a random morphologic pattern (87%) but occasionally showed a peripheral predominance (13%). There was no statistically significant difference in the prevalence of other pathologies in ankles with and without SBM. In eight ankles with a follow-up MRI, the SBM worsened in one, remained stable in two, and improved in five ankles. None progressed to a stress fracture.<br/> Conclusion: Spotty bone marrow is an MRI finding frequently encountered in ballet dancers. It is usually self-limiting and should not be misinterpreted as a more aggressive pathology.

Conceptualisation of a region-based group of musculoskeletal pain conditions as 'tibial loading pain' and systematic review of effects of load-modifying interventions

OBJECTIVES

Conceptualisation of a clinically-relevant group of conditions as a region-based, load-related musculoskeletal pain condition ('tibial loading pain') to enable identification of evidence of treatment effect from load-modifying interventions.

DESIGN

Systematic review and evidence synthesis based on a developed and justified theoretical position.

METHODS

Musculoskeletal pain localised to the tibial (shin) region and consistent with clinical presentations of an exercise/activity-related onset mechanism, was conceptualised as a group of conditions ('tibial loading pain') that could be reasoned to respond to load modifying interventions. Five databases were searched for randomized controlled studies investigating any load-modifying intervention for pain in the anterior-anteromedial lower leg (shin). Study quality was evaluated (Risk of Bias Tool Version 2) and level of certainty for the findings assessed.

RESULTS

Six studies reporting seven comparisons were included. Interventions included braces, anti-pronation taping, compression stocking and a stretch + strengthening programme. All included studies were assessed as having unclear or high risk of bias. The review found no evidence of beneficial effect from any of the load-modifying interventions on symptoms, physical performance or biomechanical measures, apart from a possible benefit of anti-pronation 'kinesio' taping. There was very low certainty evidence that kinesio taping improves pain and pain-free hopping distance after one week. The braces were associated with minor adverse effects and problems with acceptability.

CONCLUSIONS

None of the treatments investigated by the included studies can be recommended. Conceptualisation of the problem as regional, primarily loading-related pain rather than as multiple distinct pathoanatomically-based conditions, and clearer load-modifying hypotheses for interventions are recommended.

Snapping Plantaris Tendon: A Rare Case in a Competitive Dancer

Pathology associated with the plantaris includes rupture of the tendon and an association with mid-substance Achilles tendinopathy in some patients. There have only been two previous case reports in the literature in English language describing snapping of the plantaris tendon. We present a case report of a 15-year-old female competitive dancer who described pain and an audible popping at the medial margin of the Achilles tendon while squatting. Physical examination revealed visible and audible popping of the plantaris, and ultrasonography confirmed the diagnosis. After symptoms persisted despite nonsurgical treatment with physical therapy, the patient underwent an open plantaris tenotomy. By 8 weeks after surgery, she had resumed dancing. Twenty-three months after her operation, she reported an excellent outcome and full recovery with no limitations to her physical activity. She reported having no pain, a Foot and Ankle Ability Measure Activities of Daily Living Subscale score of 100, and a Foot and Ankle Ability Measure Sports Subscale score of 100. This case demonstrates a successful course of treatment for this uncommon pathology within the context of a competitive dancer.

MRI of the Achilles tendon-A comprehensive pictorial review. Part one

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Presence of normal septation between subtendons may mimic an intrasubstance tear.

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MRI is superior to ultrasound in detection of partial tears.

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Ultrasound is as useful as MRI in detection of tendinopathy and full-thickness tears.

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Kager's fat pad is involved in infection more than in postoperative changes.

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The Achilles tendon xanthoma has a higher signal on T1- and T2-weighted sequences.

The normal Achilles tendon is composed of twisted subtendons separated by thin high signal septae, which are a potential pitfall on MRI because they mimic a tendon tear.

Tendinopathy and full thickness tears may be assessed effectively both on MRI and ultrasound. MRI is superior to ultrasound in detection of partial tears and for postoperative assessment. The use of fat suppression sequences allows the ability to detect focal lesions. Sagittal and coronal sections are useful for assessing the distance between stumps of a ruptured tendon. Sequences with contrast are indicated in postoperative investigations and suspicion of infection, arthritis or tumor. MRI may reveal inflammatory changes with minor symptoms long before the clinical manifestations of seronegative spondyloarthropathy. The most common non-traumatic focal lesion of the Achilles tendon is Achilles tendon xanthoma, which is manifested by intermediate or slightly higher signal on T1- and T2-weighted images compared to that in the normal Achilles tendon. Other tumors of the Achilles tendon are very rare, whereas the involvement of the tendon from tumor in adjacent structures is more frequent.

The novel MRI sequences may help to detect disorders of the Achilles tendon more specifically before clinical manifestation. Regeneration or remodeling of the Achilles tendon can be non‐invasively detected and monitored in diffusion tensor imaging. Assessment of healing is possible using T2-mapping while evaluating the tendon vascularization in intravoxel incoherent motion MRI.

Associations between early neutering, obesity, outdoor access, trauma and feline degenerative joint disease

OBJECTIVES

The aim of this case-control study was to identify early-life risk factors associated with the occurrence of owner-reported mobility changes in 6-year-old cats by examining prospective data from a longitudinal cohort study of pet cats, the Bristol Cats study.

METHODS

Data on potential risk factors were obtained from seven sequential questionnaires completed between the ages of 2-4 months and 5 years. Mobility-related questions from the study questionnaire distributed at the age of 6 years were used to calculate each cat's mobility score. Cats with mobility scores of ⩾2 and 0 were allocated to the case and control groups, respectively, and the cat's status was the outcome variable.

RESULTS

Of the 799 cats included for analysis, 238 (29.8%) had owner-reported mobility changes. Binomial logistic regression using backwards elimination identified four risk factors for owner-reported mobility changes at 6 years of age: entire neuter status at 6 months of age (odds ratio [OR] 1.97; 95% confidence interval [CI] 1.26-3.07), sustained trauma before 6 years of age (OR 1.85; 95% CI 1.30-2.60), outdoor access at 6 years of age (OR 1.67; 95% CI 0.96-2.90) and overweight/obese status at 6 years of age (OR 1.62; 95% CI 1.13-2.33).

CONCLUSIONS AND RELEVANCE

Risk factor analysis demonstrated that obesity, outdoor access and a history of trauma may predispose cats to developing owner-reported mobility changes associated with degenerative joint disease, whereas neutering before 6 months of age appears to decrease that risk.

Intrinsic modifiable risk factors in ballet dancers: Applying evidence based practice principles to enhance clinical applications

INTRODUCTION

The risk of musculoskeletal injury is multifactorial (Bahr 2005). Injury risk is a composite of intrinsic and extrinsic risk factors that can be modifiable or non-modifiable. Ballet dancers have unique risk factors, due to the nature of their art and sport. The purpose of this literature review is to identify intrinsic modifiable risk factors for injury in ballet dancers. The secondary purpose is to investigate potential screening tools which can be used to identify these risk factors.

METHODS

The authors performed a review of the literature in October 2017 within the databases of MEDLINE Complete, SPORTDiscus, and PubMed Central following a list of inclusion and exclusion criteria.

RESULTS

A review of the available literature identified seven intrinsic modifiable factors specifically for ballet dancers and seven appropriate screening tools.

DISCUSSION

The literature identified the most common intrinsic modifiable risk factors associated with ballet dancers to be: hypermobility, fatigue, overuse, neuromuscular dysfunction, degree of turnout, weakness of core and lower extremity musculature, and lower extremity range of motion (ROM) discrepancies.

CONCLUSION

Sports medicine professionals who manage these performing artists can use this literature review to help develop injury prevention programs and enhance return to sport decision.

Patellofemoral pain, body morphology and alignment in female pubertal dancers: One-year follow-up

The aim of this study was to assess changes in body morphology, anatomical alignment and prevalence of patellofemoral pain (PFP) in young female dancers along one year of pubertal growth, and to identify the risk factors related to PFP in these young dancers. Both legs of 60 dancers were evaluated during grade 7 and again after 1-year. At each of these points in time, the dancers were interviewed concerning their background, and anthropometric measurements, lower-limb physical examinations and knee ultrasound scans were performed. Morphological parameters changed significantly from baseline to follow-up. PFP was found in 53.3% of the dancers' knees at baseline. At follow-up, 55.4% of the asymptomatic knees at baseline developed PFP, and only 9.4% of the symptomatic knees at baseline recovered. Lower BMI was identified among dancers who developed PFP during follow-up compared with dancers with no PFP, either at baseline or at follow-up. A positive grinding and positive Patellar Inhibition Test (PIT) were found to be risk factors for PFP at follow-up. A high prevalence of young dancers suffered PFP, from injuries they sustained mostly during the 1-year of dance practice. Parameters predisposing the dancers to PFP should be identified at early stages of dance class.

Ultrasonography findings and physical examination outcomes in dancers with and without patellofemoral pain

OBJECTIVES

To identify whether a physical examination for patello-femoral pain (PFP) is related to ultrasonography findings at the knee, and to identify possible factors related to PFP in young dancers.

METHODS

Sixty-seven young female dancers (7th grade, aged 12.8 ± 0.5) from three schools with identical special dance programs were included in the study. All the dancers were interviewed for demographic details, dance background, and training intensity; were evaluated for anthropometric measurements; underwent physical examination of both knees for PFP and for knee range of motion (ROM); and, had ultrasonography assessment for pathologies and of anatomical parts of their knees.

RESULTS

PFP was found in 54.5% of the 134 knees physically examined. In ultrasonography assessment, infra-articular effusion was found in 46.2% of the knees examined. H/week of dance practice was significantly higher among dancers with PFP (in both knees) compared with dancers with no PFP (p < .05). Knees with PFP had a significantly higher prevalence of intra articular effusion (p = .018) and higher prevalence of genu-recurvatum (p = .042). Knees with PFP had significantly greater growth plate width-anterior tibial tuberosity (p = .022) and a greater bony trochlear groove angle (p = .048).

CONCLUSION

This study describes the relationship between physical examination for PFP and the sonographic findings, and the factors related to knee injuries. The results showed a high prevalence of PFP and intra articular knee effusion among young dancers at the age of 12-13 years; and, that the number of hours of practice and anatomical structure are related to PFP. Our results should alert physicians, physiotherapists, athletic trainers and dance teachers to the need for devising modifications of training and injury prevention strategies from a young age (<12 years old).

Twenty-Year Systematic Review of the Hip Pathology, Risk Factors, Treatment, and Clinical Outcomes in Artistic Athletes-Dancers, Figure Skaters, and Gymnasts

OBJECTIVE

To identify (1) the predominant level of evidence of the clinical studies regarding the hip pathology, risk factors, treatment, and clinical outcomes in artistic athletes (dancers, figure skaters, and gymnasts) (2) the most commonly reported hip pathology, risk factors, treatments, and clinical outcomes in dancers, figure skaters, and gymnasts.

METHODS

To conduct this systematic review PubMed, EMBASE, and Scopus databases were searched for relevant studies and pertinent data were collected from the eligible articles. Included were studies which reported hip injuries in artistic athletes, the risk factors, treatment, and/or the clinical outcomes. We excluded case reports or irrelevant studies. No meta-analysis was performed because of study heterogeneity. The methodical index for nonrandomized studies (MINORS) criteria were used for quality control.

MAIN RESULTS

Thirty-eight studies were included in the analysis. The mean MINORS score was 13.6 ± 4.6 points indicating fair quality of evidence of the included articles. The predominant level of evidence was level IV. Chondrolabral pathology and muscle injuries were the most commonly reported pathologies. We found only 2 risk factor analysis studies; however, many studies reported risk correlation between artistic sports or imaging findings and hip pathology. Treatment strategies were reported in only 7 studies, clinical outcomes are significantly underreported.

CONCLUSION

Chondrolabral pathology was the most commonly reported hip pathology in artistic athletes, however, prospective cohort studies are necessary to really understand these injuries and their associated risk factors. The lack of clinical outcomes is significant and future data collection is required to assess the effectiveness of the various treatments.

Rehabilitation and Prevention of Proximal Hamstring Tendinopathy

Proximal hamstring tendinopathy (PHT) comprises a small but significant portion of hamstring injuries in athletes, especially runners. PHT is a chronic condition that is clinically diagnosed but can be supported with imaging. The main presenting complaint is pain in the lower gluteal or ischial region that may or may not radiate along the hamstrings in the posterior thigh. There is little scientific evidence on which to base the rehabilitation management of PHT. Treatment is almost always conservative, with a focus on activity modification, addressing contributing biomechanical deficiencies, effective tendon loading including eccentric training, and ultrasound-guided interventional procedures which may facilitate rehabilitation. Surgery is limited to recalcitrant cases or those involving concomitant high-grade musculotendinous pathology. The keys to PHT management include early and accurate diagnosis, optimal rehabilitation to allow for a safe return to preinjury activity level, and preventative strategies to reduce risk of reinjury.