Subtalar subluxation in ballet dancers

Magnetic resonance imaging findings associated with posterior ankle impingement syndrome are prevalent in elite ballet dancers and athletes

OBJECTIVE

To report the prevalence of MRI features commonly associated with posterior ankle impingement syndrome in elite ballet dancers and athletes and to compare findings between groups.

MATERIALS AND METHODS

Thirty-eight professional ballet dancers (47.4% women) were age- and sex-matched to 38 elite soccer or cricket fast bowler athletes. All participants were training, playing, and performing at full workload and underwent 3.0-T standardised magnetic resonance imaging of one ankle. De-identified images were assessed by one senior musculoskeletal radiologist for findings associated with posterior ankle impingement syndrome (os trigonum, Stieda process, posterior talocrural and subtalar joint effusion-synovitis, flexor hallucis longus tendon pathology and tenosynovitis, and posterior ankle bone marrow oedema). Imaging scoring reliability testing was performed.

RESULTS

Posterior talocrural effusion-synovitis (90.8%) and subtalar joint effusion-synovitis (93.4%) were common in both groups, as well as the presence of either an os trigonum or Stieda process (61.8%). Athletes had a higher prevalence of either os trigonum or Stieda process than dancers (74%, 50% respectively, P = 0.03). Male athletes had a higher prevalence of either os trigonum or Stieda process than male dancers (90%, 50% respectively, P = 0.01), or female athletes (56%, P = 0.02). Posterior subtalar joint effusion-synovitis size was larger in dancers than athletes (P = 0.02). Male and female dancers had similar imaging findings. There was at least moderate interobserver and intraobserver agreement for most MRI findings.

CONCLUSION

Imaging features associated with posterior impingement were prevalent in all groups. The high prevalence of os trigonum or Stieda process in male athletes suggests that this is a typical finding in this population.

Incidence and Prevalence of Musculoskeletal Injury in Ballet: A Systematic Review

BACKGROUND

Most published studies on injuries in the ballet dancer focus on the lower extremity. The rigors of this activity require special training and care. By understanding prevalence and injury pattern to the musculoskeletal system, targeted prevention and treatment for this population can be developed.

PURPOSE

To determine the incidence and prevalence of musculoskeletal injuries in ballet.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A systematic review registered with PROSPERO was performed using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Level 1 through 4 evidence studies reporting incidence of musculoskeletal injuries in male and female ballet dancers were included, with the numbers and types of injuries extracted from each. Injury rates were recorded and calculated based on professional status, sex, and nature of injury. Incidence was defined as number of injuries sustained over a specific time. Prevalence was defined as proportion of subjects with an injury at a given point in time.

RESULTS

The studies analyzed reported injury incidence or prevalence in more than 1365 amateur and 900 professional dancers. The mean age was 16.2 years among amateur and 27.0 years among professional dancers. The incidence of injury among amateur dancers was 0.99 and 1.09 injuries per 1000 dance hours in males and females, respectively; 75% of injuries were overuse, with similar rates among males and females. In professional dancers, the incidence of injury was 1.06 and 1.46 injuries per 1000 dance hours in males and females, respectively, and 64% of female injuries were overuse, compared with 50% in males (P < .001). Only 3 studies provided prevalence data, including 62% prevalence of lumbosacral pain, 58% painful snapping hip, and 29% patellofemoral pain. Lower extremity injuries comprised 66% to 91% of all injuries, with the foot and ankle accounting for 14% to 57%.

CONCLUSION

The overall incidence of injury among amateur and professional ballet dancers is 0.97 and 1.24 injuries per 1000 dance hours, respectively. The majority are overuse in both amateur and professional dancers, with amateur ballet dancers showing a higher proportion of overuse injuries than professionals (P < .001). Male professional dancers show a higher proportion of traumatic injuries, accounting for half of their injuries (P < .001).

Subtalar dislocations

Subtalar dislocations make up 1-2% of all dislocations, about 75% of them being medial dislocations. Treatment consists of early reduction under adequate sedation. In cases of soft tissue interposition or locked dislocations, open reduction is warranted. More than 60% of subtalar dislocations are associated with additional fractures, therefore a postreduction CT is recommended. Complications include avascular necrosis of the talus, infection, posttraumatic arthritis, chronic subtalar instability, and complex regional pain syndrome with delayed reduction. The prognosis of purely ligamentous injuries is excellent after early reduction. Negative prognostic factors include lateral and open dislocations, total talar dislocations, and associated fractures.

Musculoskeletal injuries and pain in dancers: a systematic review

OBJECTIVE

To assemble and synthesize the best evidence on the epidemiology, diagnosis, prognosis, treatment, and prevention of musculoskeletal injuries and pain in dancers.

DATA SOURCES

Medline, CINAHL, PsycINFO, Embase, and other electronic databases were searched from 1966 to 2004 using key words such as dance, dancer, dancing, athletic injuries, occupational injuries, sprains and strains, and musculoskeletal diseases. In addition, the reference lists of relevant studies were examined, specialized journals were hand-searched, and the websites of major dance associations were scanned for relevant information.

STUDY SELECTION

Citations were screened for relevance using a priori criteria, and relevant studies were critically reviewed for scientific merit by the best evidence synthesis method. After 1865 abstracts were screened, 103 articles were reviewed, and 32 (31%) of these were accepted as scientifically admissible (representing 29 unique studies).

DATA EXTRACTION

Data from accepted studies were abstracted into evidence tables relating to the prevalence and associated factors, incidence and risk factors, diagnosis, treatment, economic costs, and prevention of musculoskeletal injuries and pain in dancers.

DATA SYNTHESIS

The scientifically admissible studies consisted of 15 (52%) cohort studies, 13 (45%) cross-sectional studies, and 1 (3%) validation study of a diagnostic assessment tool. There is a high prevalence and incidence of lower extremity and back injuries, with soft tissue and overuse injuries predominating. For example, lifetime prevalence estimates for injury in professional ballet dancers ranged between 40% and 84%, while the point prevalence of minor injury in a diverse group of university and professional ballet and modern dancers was 74%. Several potential risk factors for injury are suggested by the literature, but conclusive evidence for any of these is lacking. There is preliminary evidence that comprehensive injury prevention and management strategies may help decrease the incidence of future injury.

CONCLUSIONS

The dance medicine literature is young and heterogeneous, limiting our ability to draw consistent conclusions. Nonetheless, the best available evidence suggests that musculoskeletal injury is an important health issue for dancers at all skill levels. Better quality research is needed in this specialized area. Future research would benefit from clear and relevant research questions being addressed with appropriate study designs, use of conceptually valid and clinically meaningful case definitions of injury and pain, and better reporting of studies in line with current scientific standards.

Bone stress injury of the ankle in professional ballet dancers seen on MRI

Background

Ballet Dancers have been shown to have a relatively high incidence of stress fractures of the foot and ankle. It was our objective to examine MR imaging patterns of bone marrow edema (BME) in the ankles of high performance professional ballet dancers, to evaluate clinical relevance.

Methods

MR Imaging was performed on 12 ankles of 11 active professional ballet dancers (6 female, 5 male; mean age 24 years, range 19 to 32). Individuals were imaged on a 0.2 T or 1.5 T MRI units. Images were evaluated by two musculoskeletal radiologists and one orthopaedic surgeon in consensus for location and pattern of bone marrow edema. In order to control for recognized sources of bone marrow edema, images were also reviewed for presence of osseous, ligamentous, tendinous and cartilage injuries. Statistical analysis was performed to assess the strength of the correlation between bone marrow edema and ankle pain.

Results

Bone marrow edema was seen only in the talus, and was a common finding, observed in nine of the twelve ankles imaged (75%) and was associated with pain in all cases. On fluid-sensitive sequences, bone marrow edema was ill-defined and centered in the talar neck or body, although in three cases it extended to the talar dome. No apparent gender predilection was noted. No occult stress fracture could be diagnosed. A moderately strong correlation (phi = 0.77, p= 0.0054) was found between edema and pain in the study population.

Conclusion

Bone marrow edema seems to be a specific MRI finding in the talus of professional ballet dancers, likely related to biomechanical stress reactions, due to their frequently performed unique maneuvers. Clinically, this condition may indicate a sign of a bone stress injury of the ankle.

Diagnosis and management of the painful ankle/foot part 1: clinical anatomy and pathomechanics

Distinctive anatomical features can be witnessed in the ankle/foot complex, affording specific pathological conditions. Disorders of the ankle/foot complex are multifactoral and features in both the clinical anatomy and biomechanics contribute to the development of ankle/foot pain. The superior tibiofibular, distal tibiofibular, talocrural, subtalar, and midtarsal joint systems must all participate in function of the ankle/foot complex, as each biomechanically contributes to functional movements and clinical disorders witnessed in the lower extremity. A clinician's ability to effectively evaluate, diagnose, and treat the distal lower extremity is largely reliant upon a foundational understanding of the clinical anatomy and biomechanics of this complex complex. Thus, clinicians are encouraged to consider these distinctions when examining and diagnosing disorders of the ankle/foot.

Dance-Related Injury

Although dance medicine has derived extensive knowledge from sports medicine, some aspects covered in the practice of dance medicine are unique to this field. Acute and overuse injuries must be analyzed within the scope of associated mechanisms of injury, mainly related to the practice of specific dance techniques. Even though most available medical literature concerning dance medicine is specific to ballet-related conditions, many of the concepts covered here and in other articles can be helpful in the treatment and diagnosis of participants in other dance disciplines. Continued research is expanding the knowledge on injury patterns of different dance disciplines. It is the experience of dance practitioners that dancers are quite in touch with their bodies; thus, when their ailments are systematically analyzed, and underlying cause can usually be identified. In this sense, it is evident that the principles of dance medicine and rehabilitation allow the practitioner to arrive at a diagnosis and treat the underlying causes to prevent reinjury, ameliorate sequelae from injury, and minimize residual deficits after injury.

Chronic subluxation of the midtarsal joint of the foot: a case report

Traumatic injuries to the midtarsal joint are quite uncommon and usually involve fractures of adjacent bones. Pure dislocations without fracture are very rare. A patient sustained a pure dislocation that was treated with a nonweight-bearing cast for six weeks, but she went on to present with chronic subluxation at the midtarsal joint. Imaging modalities were confusing because the pathology was seen only when the deformation was present throughout the imaging examination, not when it was reduced. Stress varus- valgus radiographs of the foot, not ankle, provided a definitive diagnosis. The patient was treated successful by arthrodesis of calcaneocuboid and talo-navicular joints (the midtarsal joint which was unstable) without subtalar fusion.