Publication Rates of Podium Presentations at an Annual Orthopedic Surgery Resident and Fellow Research Symposium.

Introduction Research is an important aspect of residency and fellowship programs across the country. Developing strategies to foster research productivity is worthwhile. An annual research project is one strategy that some programs implement. Methods All resident and fellow (Sports Medicine, Adult Reconstruction, Spine) presentations at an orthopedic surgery department's annual research symposium from June 2016 through June 2021 were identified. Abstract titles, title keywords, and author names were searched in PubMed and Google Scholar to identify the presence of a peer-reviewed publication. Using the total number of research symposium presentations given, the publication rate was calculated for each year, as well as collectively for 2016 to 2021. In addition to publication rate, first author percent, number of citations, Altmetric score, and journal impact factor were recorded. Current PGY-2 through PGY-5 residents completed a survey to assess the perceived value of the annual research symposium. Results Ninety-eight research symposium presentations were reviewed (69 residents, 29 fellows). Forty (58%) resident studies were published and 28 were first-author publications (70%). Thirteen (45%) fellow studies were published and seven were first-author publications (54%). Combining residents and fellows, the overall publication rate was 54% (53/98), and 66% of these (35/53) were first-author publications. There was a wide range of published manuscript journal impact factors, Altmetric scores, and number of citations. All residents surveyed reported finding value in the research symposium. Conclusion The overall publication rate of presentations at an annual orthopedic surgery department research symposium between 2016 and 2021 was 54%, consistent with publication rates reported at National Orthopedic Surgery Society meetings. All residents reported finding value in the annual research symposium. The results of this study support the academic value of implementing a required annual research project and may provide a useful gauge to inform residency and fellowship curricula at other institutions.

Advanced care at home at scale in an integrated health care system.

OBJECTIVES: To assess the feasibility of scaling advanced care at home (ACAH) (otherwise known as hospital at home) within an integrated health care delivery system. STUDY DESIGN: Retrospective cohort study of patients qualified for hospital-level care who were admitted to either ACAH or a traditional hospital. METHODS: From April 29, 2020, to November 14, 2021, patients requiring hospital-level care received Kaiser Permanente at Home or traditional hospital care. In a subgroup of patients, we compared outcomes for Kaiser Permanente at Home vs traditional hospital care using regression models. RESULTS: A total of 1005 patients were admitted to Kaiser Permanente at Home. Average daily census (ADC) was intentionally increased over time in stages, from 7.2 to 8.8, then to 12.7. The maximum daily census was 22, with a peak ADC of 16, representing 9% of the total hospital inpatient medicine service census. During this time, there were numeric decreases in Kaiser Permanente at Home escalation rates (17.5% to 10.8%), median length of stay (7.43 days to 5.46 days), and readmission rates (9.79% to 9.24%). A subgroup of Kaiser Permanente at Home patients contributed to the comparative analyses, which showed that patients admitted to Kaiser Permanente at Home were 64% less likely to experience delirium than patients admitted for traditional hospital care (OR, 0.36; 95% CI, 0.15-0.88; P = .026). Comparisons of quality metrics across stages of implementation (readmissions, escalations, length of stay) were inconclusive. CONCLUSION: In an integrated delivery system, ACAH care can be scaled and can create hospital capacity. However, our data were inconclusive regarding quality throughout scaling due to the small effective sample size, necessitating replication in a larger prospective study with adequate power/precision.

Plantar Plating for Medial Naviculocuneiform Arthrodesis in Progressive Collapsing Foot Deformity.

Background: Medial column procedures are commonly used to treat progressive collapsing foot deformity (PCFD) reconstruction. The aim of this research is to present the clinical results of plantar plating for medial naviculocuneiform (NC) arthrodesis when NC joint pathology contributes to medial arch collapse. The authors hypothesized that lag screws with a plantar neutralization plate would result in a satisfactory NC joint fusion rate. Methods: A single-surgeon, retrospective case series was performed on patients with flexible PCFD who underwent NC arthrodesis using lag screws and a contoured neutralization plate applied plantarly across the medial NC joint as part of PCFD reconstruction. Thirteen patients (11 females, 2 males; mean age 53.1 [34-62] years) between 2016 and 2019 were identified for inclusion. Mean follow-up was 25.2 ± 12.7 months. Preoperative and postoperative anteroposterior talo-first metatarsal angle, lateral talo-first metatarsal angle, talonavicular coverage angle, and calcaneal pitch were measured. Union was evaluated radiologically. AOFAS midfoot scores were recorded at final follow-up. Results: All parameters demonstrated a significant improvement. Fusion was confirmed in 11 of 13 patients (85%) at a mean 5.7 ± 2.1 months. One patient required a revision of their NC fusion because of symptomatic nonunion. There were no cases of symptomatic plantar hardware. Conclusion: The results of this small cohort series suggest that lag screw with plantar plate NC arthrodesis yielded generally improved short-term radiographic and clinical outcomes in PCFD patients with medial arch collapse through the NC joint.Level of Evidence: Level IV, retrospective case series.

Interrater and Intrarater Reliability of the Beighton Score: A Systematic Review.

BACKGROUND: The Beighton score is commonly used to assess the degree of hypermobility in patients with hypermobility spectrum disorder. Since proper diagnosis and treatment in this challenging patient population require valid, reliable, and responsive clinical assessments such as the Beighton score, studies must properly evaluate efficacy and effectiveness. PURPOSE: To succinctly present a systematic review to determine the inter- and intrarater reliability of the Beighton score and the methodological quality of all analyzed studies for use in clinical applications. STUDY DESIGN: Systematic review; Level of evidence, 3. METHODS: A systematic review of the MEDLINE, Embase, CINAHL, and SPORTDiscus databases was performed. Studies that measured inter- or intrarater reliability of the Beighton score in humans with and without hypermobility were included. Non-English, animal, cadaveric, level 5 evidence, and studies utilizing the Beighton score self-assessment version were excluded. Data were extracted to compare scoring methods, population characteristics, and measurements of inter- and intrarater reliability. Risk of bias was assessed with the COSMIN (Consensus-Based Standards for the Selection of Health Measurement Instruments) 2017 checklist. RESULTS: Twenty-four studies were analyzed (1333 patients; mean ± SD age, 28.19 ± 17.34 years [range, 4-71 years]; 640 females, 594 males, 273 unknown sex). Of the 24 studies, 18 reported raters were health care professionals or health care professional students. For interrater reliability, 5 of 8 (62.5%) intraclass correlation coefficients and 12 of 19 (63.2%) kappa values were substantial to almost perfect. Intrarater reliability was reported as excellent in all studies utilizing intraclass correlation coefficients, and 3 of the 7 articles using kappa values reported almost perfect values. Utilizing the COSMIN criteria, we determined that 1 study met "very good" criteria, 7 met "adequate," 15 met "doubtful," and 1 met "inadequate" for overall risk of bias in the reliability domain. CONCLUSION: The Beighton score is a highly reliable clinical tool that shows substantial to excellent inter- and intrarater reliability when used by raters of variable backgrounds and experience levels. While individual components of risk of bias among studies demonstrated large discrepancy, most of the items were adequate to very good.

Twenty Five-Year Publication Trends in Foot and Ankle Literature: Improved Methodological Quality and Internationality With Time.

BACKGROUND: Methodological quality and author internationality are increasing in orthopaedic surgery. The purpose of this study was to evaluate the methodological quality and author geography trends from 1994 to 2019 in high-quality foot and ankle journals. METHODS: Analyses of 1,242 foot and ankle publications in Foot and Ankle International, American Journal of Bone and Joint Surgery, and American Journal of Sports Medicine were done for 1994, 1999, 2004, 2009, 2014, and 2019. Articles were classified according to study type, level of evidence (LOE), and author's country of publication. RESULTS: The most common clinical study was therapeutic (65.4). Significant increases were noted in the proportion of therapeutic (P < 0.01) and prognostic (P < 0.01) articles. The average LOE increased from 3.96 ± 1.01 to 3.19 ± 0.97 (P < 0.01). The proportion of Level I (P = 0.29) and level IV articles (P = 0.21) remained constant, level II (P < 0.01) and level III (P < 0.01) articles increased, and level V (P < 0.01) articles decreased. United States authorship decreased from 78.1% in 1994 to 44.8% in 2009, then remained constant through 2019 (P < 0.01). CONCLUSION: This study demonstrated an improvement in LOE of foot and ankle publications across a 25-year period in three high-quality orthopaedic journals. Increasing internationality was also observed.

On-site Clinical Care for Professional Dance Companies.

Thirty years ago the introduction of on-site health care for professional dance companies was a novel concept and dance medicine clinicians often had limited on-site hours, restricted treatment space, and small budgets. Companies are now developing fully staffed on-site clinics and backstage care that provide a multidisciplinary approach to dancer health and wellness. On-site dance medicine programs focus on holistic dancer health and preventive care rather than just triage and rehabilitation. Best practice recommendations for care of professional dancer patients allow for streamlined patient care within a network of medical professionals who understand the demands of a professional dance career.

An Injury Prevention Program for Professional Ballet: A Randomized Controlled Investigation.

BACKGROUND: Few investigations have examined dance-specific injury prevention programs (IPPs), and no published randomized controlled trials are available that evaluate IPPs for dance. HYPOTHESIS: The implementation of an IPP will significantly reduce the risk of injury in professional ballet dancers. STUDY DESIGN: Randomized controlled trial; Level of evidence, 2. METHODS: A randomized controlled trial was designed that entailed a superiority model for the intervention group. All professional dancers from a single ballet company were eligible to participate. Randomization and allocation were performed before the start of the season. The control group practiced and performed without change to preexisting standard operating practice. The IPP group was instructed to perform a 30-minute exercise program 3 times per week over the 52-week study period. Injuries were recorded. Standard continuous and categorical data comparisons and correlations were used. Cox proportional hazards regression models for recurrent failures were used wherein the hazard ratio indicates the relative likelihood of injury in the control versus intervention groups. RESULTS: Of the 52 eligible dancers, 75% (n = 39) participated. Of these 39 dancers, 19 (9 males, 10 females; mean age, 26.6 ± 4.0 years) were randomized to the control group and 20 (11 males, 9 females; mean age, 25.1 ± 5.1 years) to the IPP group. No significant (P > .05) difference was found in baseline demographics between groups. A total of 116 injuries were recorded for the entire study population (49 IPP; 67 control). Traumatic and chronic injuries accounted for 54% and 46% of injuries, respectively. The injury rate was 82% less (IPP hazard ratio, 0.18; z = -2.29; P = .022) in the IPP group after adjustment for confounding variables, and time between injuries was 45% longer (IPP hazard ratio, 0.55; z = -2.20; P = .028) than for controls. CONCLUSION: The present study is the first prospective randomized controlled investigation of an IPP for professional ballet. The results showed an 82% decrease in injury rate for the intervention group and an extended period from previous injury to subsequent injury. REGISTRATION: NCT04110002 (ClinicalTrials.gov identifier).

High Prevalence of Connective Tissue Gene Variants in Professional Ballet.

BACKGROUND: There is a high prevalence of hypermobility spectrum disorder (HSD) in dancers. While there is no known genetic variant for HSD, hypermobile Ehlers-Danlos syndrome is a genetic disorder that exists within HSD. There are many connective tissue disorders (CTDs) with known (and unknown) genes associated with hypermobility. Hypermobility has distinct advantages for participation in flexibility sports, including ballet. PURPOSE: To determine the prevalence of gene variants associated with hypermobility in a large professional ballet company. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: In this cross-sectional investigation, 51 professional male and female dancers from a large metropolitan ballet company were eligible and offered participation after an oral and written informed consent process. Whole blood was obtained from peripheral venipuncture, and DNA was isolated. Isolated DNA was subsequently enriched for the coding exons of 60 genes associated with CTD that included hypermobility as a phenotype, including Ehlers-Danlos syndromes, osteogenesis imperfecta, Marfan syndrome, and others. Genes were targeted with hybrid capture technology. Prepared DNA libraries were then sequenced with next-generation sequencing technology. Genetic database search tools (Human Gene Mutation Database and e!Ensembl, http://useast.ensembl.org/ ) were used to query specific variants. Descriptive statistics were calculated. RESULTS: Of 51 dancers, 32 (63%) agreed to participate in DNA analysis (mean ± SD age, 24.3 ± 4.4 years; 18 men, 14 women). Twenty-eight dancers had at least 1 variant in the 60 genes tested, for an 88% prevalence. A total of 80 variants were found. A variant in 26 of the 60 genes was found in at least 1 dancer. Among the 28 dancers with variants, 16 were found in the TTN gene; 10 in ZNF469; 5 in RYR1; 4 in COL12A1; 3 in ABCC6 and COL6A2; 2 in ADAMTS2, CBS, COL1A2, COL6A3, SLC2A10, TNC, and TNXB; and 1 in ATP6V0A2, B4GALT7, BMP1, COL11A1, COL5A2, COL6A1, DSE, FBN1, FBN2, NOTCH1, PRDM5, SMAD3, and TGFBR1. Nine variants found in this population have never been reported. No identified variant was identical to any other variant. No identified variant was known to be disease causing. In the general population, the prevalence of each variant ranges from never reported to 0.33%. In the study population, the prevalence of each variant was 3.13%. There was no association between hypermobility scores and genetic variants. CONCLUSION: Genetic variants in CTD-associated genes are highly prevalent (88%) in professional ballet dancers. This may significantly account for the high degree of motion in this population.

Treatment of Proximal Fifth Metatarsal Fractures and Refractures With Plantar Plating in Elite Athletes.

BACKGROUND:: Fractures of the proximal fifth metatarsal are relatively common foot injuries in elite athletes. Acute fixation with intramedullary screws is the most common operative treatment. However, the rate of nonunion and refracture after this procedure remains a concern. The purpose of this study was to determine rates of clinical and radiographic fracture healing, return to sport, and patient-reported clinical outcomes of elite athletes with proximal fifth metatarsal fracture or refracture treated with plantar plating. METHODS:: An institutional review board-approved retrospective single-surgeon case series investigation assessed athletes (competing at college, Olympic, or professional levels) with proximal fifth metatarsal fracture or refracture, treated with open reduction internal fixation and calcaneal autogenous bone grafting using a plantar plate with a minimum 2-year follow-up. Demographic data, radiographic evaluation, and the time until return to unrestricted sporting competition were collected and analyzed. Means with standard deviations were calculated for continuous data, and frequencies of categorical data were calculated in percentages. RESULTS:: Four refractures and 4 primary fractures were treated in 8 male athletes with a mean age of 21.9 ± 1.9 years at a mean follow-up of 3.2 ± 0.4 years. Two patients experienced temporary neuropraxia of the sural nerve that resolved within 6 weeks. There were no incisional complications, delayed unions or nonunions, refractures, hardware loosening, or complaints of hardware prominence. Clinically asymptomatic radiographic union was observed in 100% of the athletes at 6.5 ± 1.1 weeks and full release given at 12.3 ± 1.9 weeks. All athletes returned to sport at the same level of competition. CONCLUSION:: With minimum 2-year follow-up, plantar plating of proximal fifth metatarsal fractures was an effective and safe technique that was used in both primary and revision settings. LEVEL OF EVIDENCE:: Level IV, case series.

Physician Rating Scales Do Not Accurately Rate Physicians.

The purpose of this study was to determine the proportion of questions used by online physician rating scales to directly rate physicians themselves. A systematic review was performed of online, patient-reported physician rating scales. Fourteen websites were identified containing patient-reported physician rating scales, with the most common questions pertaining to office staff courtesy, wait time, overall rating (entered, not calculated), trust/confidence in physician, and time spent with patient. Overall, 28% directly rated the physician, 48% rated both the physician and the office, and 24% rated the office alone. There is great variation in the questions used, and most fail to directly rate physicians themselves. [Orthopedics. 2018; 41(4):e445-e456.].

A Biomechanical Comparison of Fifth Metatarsal Jones Fracture Fixation Methods.

BACKGROUND: Fifth metatarsal base fractures of the metaphyseal-diaphyseal watershed junction (Jones fracture) are commonly treated with surgical fixation in athletes. Intramedullary screw fixation remains the most utilized construct, although plantar-lateral plating is an alternative. Purpose/Hypothesis: The purpose was to compare the mechanical strength of fracture fixation between an intramedullary screw and plantar-lateral plating. The hypothesis was that plantar-lateral plate fixation would allow for more cycles and higher peak loads before failure, as well as less fracture gapping, than would an intramedullary screw in cadaveric foot specimens with simulated Jones fractures exposed to cantilever bending. STUDY DESIGN: Controlled laboratory study. METHODS: Twelve pairs of male cadaver feet were separated into 2 groups (plate or screw) to conduct contralateral comparative testing of 2 devices with equally numbered right and left feet. For each fifth metatarsal, an osteotomy with a microsagittal saw was created to simulate a Jones fracture. The plate group underwent fixation with a 3.0-mm 4-hole low-profile titanium plate placed plantar-laterally with 3 locking screws and 1 nonlocking screw. The screw group underwent fixation with a 40- or 45-mm × 5.5-mm partially threaded solid titanium intramedullary screw. After fixation, the metatarsals were excised for biomechanical testing. Cyclic cantilever failure testing was conducted with a gradient-cycle method. Sinusoidal loading forces were applied, increasing by 5.0-pound-force increments per 10 cycles, until each specimen experienced mechanical failure of implant or bone. Failure mode, number of cycles to failure, peak failure load, gap width at the last mutual prefailure loading, and video data were recorded. Paired 2-tailed t test (α = 0.05) was used to compare groups ( P < .05 set for significance). RESULTS: Failure mode in both groups occurred predominantly at the bone-implant interface. Plate fixation resulted in significantly higher mean ± SD values for cycles to failure (63.9 ± 27.0 vs 37.3 ± 36.9, P = .01) and peak failure load (159.2 ± 60.5 N vs 96.5 ± 45.8 N, P = .01), with a significantly lower mean gap width (0.0 ± 0.0 mm vs 3.2 ± 2.4 mm, P < .01). CONCLUSION: As compared with intramedullary screw fixation, plantar-lateral plating allowed for greater cycles to failure and peak load before failure, as well as less gap width, when applied to cadaver foot specimens with simulated Jones fractures exposed to cantilever bending in a load frame. CLINICAL RELEVANCE: Early return to play among athletes before Jones fracture union is associated with increased risk of failure. This study introduces a plantar-lateral plating construct that performed more favorably than intramedullary screw fixation when applied to simulated Jones fractures in cadaveric foot specimens. Further clinical comparative studies are needed to assess the clinical use of this construct.

Performance and Return to Sport After Achilles Tendon Repair in National Football League Players.

BACKGROUND: Achilles tendon injuries are common in sports, including football. The purpose of this study was to determine (1) return-to-sport rate in National Football League (NFL) players following Achilles tendon repair, (2) postoperative career length and games per season, (3) pre- and postoperative performance, and (4) postoperative performance compared with control players matched by position, age, years of experience, and performance. METHODS: Publicly available records were used to identify NFL players who underwent Achilles tendon repair and matched controls were identified. Ninety-five players (98 surgeries) were analyzed (mean age 28.2 ± 2.8 years; mean 5.5 ± 2 .8 years in NFL at time of surgery). Demographic and performance data were collected. Comparisons between case and control groups and preoperative and postoperative time points were made using paired-samples Student t tests. RESULTS: Seventy-one (72.4%) players were able to return to sport in the NFL at a mean of 339.8 ± 84.8 days following surgery. Thirty-one (32%) Achilles tendon repairs were performed during training camp or preseason. Controls (3.6 ± 2.1 years) had a significantly longer NFL career ( P < .05) than players who underwent Achilles tendon repair (2.7 ± 2.1 years). There was no significant difference in games per season in subsequent seasons following surgery compared with controls. Postoperative performance scores were significantly worse ( P < .05) for running backs (RBs) (n = 4) and linebackers (LBs) (n = 12) compared to preoperative scores. LBs had significantly worse postoperative performance scores when compared to matched controls ( P < .05). CONCLUSION: Following Achilles tendon repair, less than 75% of players returned to the NFL. Postoperative career length was 1 season shorter than matched controls. No difference was observed in the number of games per season played compared to matched controls. Postoperative performance scores were significantly worse for RBs and LBs compared to preoperative and LBs had significantly worse postoperative performance when compared to matched controls. LEVEL OF EVIDENCE: Level III, retrospective comparative series.

Performance and Return to Sport After Sports Hernia Surgery in NFL Players.

BACKGROUND: Recognition, diagnosis, and treatment of athletic pubalgia (AP), also known as sports hernia, once underrecognized and undertreated in professional football, are becoming more common. Surgery as the final treatment for sports hernia when nonsurgical treatment fails remains controversial. Given the money involved and popularity of the National Football League (NFL), it is important to understand surgical outcomes in this patient population. HYPOTHESIS: After AP surgery, players would: (1) return to sport (RTS) at a greater than 90% rate, (2) play fewer games for fewer years than matched controls, (3) have no difference in performance compared with before AP surgery, and (4) have no difference in performance versus matched controls. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Internet-based injury reports identified players who underwent AP surgery from January 1996 to August 2015. Demographic and performance data were collected for each player. A 1:1 matched control group and an index year analog were identified. Control and case performance scores were calculated using a standardized scoring system. Groups were compared using paired Student t tests. RESULTS: Fifty-six NFL players (57 AP surgeries) were analyzed (mean age, 28.2 ± 3.1 years; mean years in NFL at surgery, 5.4 ± 3.2). Fifty-three players were able to RTS. Controls were in the NFL longer (P < .05) than players who underwent AP surgery (3.8 ± 2.4 vs 3.2 ± 2.1 years). Controls played more games per season (P < .05) than post-AP players (14.0 ± 2.3 vs 12.0 ± 3.4 games per season). There was no significant (P > .05) difference in pre- versus post-AP surgery performance scores and no significant (P > .05) difference in postoperative performance scores versus controls post-index. CONCLUSION: There was a high RTS rate after AP surgery without a significant difference in postoperative performance, though career length and games per season after AP surgery were significantly less than that of matched controls.

Plantar Plating for the Treatment of Proximal Fifth Metatarsal Fractures in Elite Athletes.

Proximal fifth metatarsal fractures, zones II and III, are commonly treated surgically, especially in elite athletes. Intramedullary screw fixation remains the most used construct despite nonunion and refracture. High tensile forces on the plantar-lateral aspect of the fifth metatarsal are difficult to control, and intramedullary screw fixation depends on ideal screw position, length, and width. The authors present a plantar plating technique with cancellous bone autograft for zones II and III proximal fifth metatarsal fractures. Rotational instability and plantar-lateral gapping are resisted by applying a compression plate to the tension side of the fracture, eliminating causes for failure. [Orthopedics. 2017; 40(3):e563-e566.].

Acute Tibialis Posterior Tendon Rupture With Pronation-Type Ankle Fractures.

Tibialis posterior tendon rupture in the setting of pronation-type ankle fractures can lead to long-term debility as a result of chronic tendon dysfunction. This rare injury pattern presents a diagnostic challenge because thorough preoperative examination of the function of the tendon is limited by pain, swelling, and inherent instability of the fracture. As such, a high index of suspicion is necessary in ankle fractures with radiographs showing a medial malleolus fracture with an associated suprasyndesmotic fibula fracture. This report describes 3 cases of tibialis posterior tendon rupture associated with pronation-type ankle fractures treated acutely with open reduction and internal fixation and primary tendon repair. Additionally, common features of this injury pattern are discussed based on the current literature. In accordance with this report, the typical mechanism of injury is high energy and includes forced pronation, external rotation, and dorsiflexion of the ankle, which places maximal stress on the tibialis posterior tendon. Rupture most commonly occurs in a relatively hypovascular area of the tendon located at the posteromedial extent of the medial malleolus fracture. In the operative treatment of pronation-type ankle fractures, direct inspection of the tibialis posterior tendon allows for timely diagnosis and treatment of associated ruptures. [Orthopedics.2016; 39(5):e970-e975.].

Radiographic Evidence of Hip Microinstability in Elite Ballet.

PURPOSE: To determine prevalence, magnitude, and predisposing radiographic features of hip subluxation in elite ballet dancers. METHODS: A cross-sectional investigation of professional male and female ballet dancers was performed using 5 plain radiographs. A "splits" anteroposterior (AP) radiograph was performed with legs abducted parallel to the trunk in the coronal plane (splits position; grand écart facial). Hip center position (HCP) was measured on standing AP pelvis and AP pelvis splits views and the difference calculated (subluxation distance) to determine prevalence and magnitude of femoral head subluxation. Student t test compared HCP on AP pelvis and splits radiographs. Pearson correlations were used to correlate splits HCP with radiographic measures of femoroacetabular impingement and dysplasia. RESULTS: Analyzing 47 dancers (21 men, 26 women; 23.8 ± 5.4 years), mean HCP on standing AP pelvis was 9.39 ± 3.33 mm versus 10.8 ± 2.92 mm on splits radiograph, with mean subluxation distance of 1.41 mm (P = .035). Forty-two dancers' femoral heads translated laterally with splits positioning, and 17 dancers (36%) exhibited a "vacuum sign" (bilateral in 71% of subjects with at least 1 hip vacuum sign). There was strong positive correlation (r = 0.461, P = .001) with splits HCP and alpha angle (Dunn 45°), and moderate negative correlation (r = -0.332, P = .022) with subluxation distance and neck-shaft angle. In men, splits HCP increased as lateral center edge angle (CEA) decreased (r = -0.437, P = .047), as anterior CEA decreased (r = -0.482, P = .027), as Tönnis angle increased (r = 0.656, P = .001), and as femoral head extrusion index increased (r = 0.511, P = .018). In women, there was moderate negative correlation (r = -0.389, P = .049) with subluxation distance and neck-shaft angle. CONCLUSIONS: Hip subluxation occurs during splits in most professional ballet dancers, with a significantly greater magnitude of subluxation in women than men. Subluxation magnitude increases with increasing alpha angle and decreasing neck-shaft angle. In men, the magnitude increases with severity of dysplasia. Women had subluxation regardless of acetabular morphology but increased subluxation with decreased neck-shaft angle. This provides radiographic support for hip microinstability in elite ballet. LEVEL OF EVIDENCE: Level IV, diagnostic.

Injuries in a Professional Ballet Dance Company: A 10-year Retrospective Study.

Ballet dancers are high-performance athletes who are particularly susceptible to a wide variety of musculoskeletal injuries. However, they are relatively understudied, and data on their injury rates are lacking. This retrospective study features the largest aggregate data on professional ballet dancers to date and aims to identify the most common diagnoses and areas of injury in this unique population to better direct preventative and clinical practices. The study encompassed a 10-year period from January 2000 to December 2010 of dancers from a single company. Data regarding the dancers' age, gender, location of injury, and diagnosis were collected from workers' compensation claims, company records, and medical records maintained by the treating doctors. These were analyzed to determine metrics on injury incidence, frequency, and diagnosis. Over the 10-year span, 574 injuries occurred. There were approximately 52 dancers per year for a total of 153 who danced at least one complete season during the study period. The average age was 27, and 53% were female. Given turnover with retirement and replacements, the total number of dancer-years was 520, indicating an injury incidence per annum of 1.10 (574 injuries per 520 dancer-years). The most common locations of injury were foot and ankle and the lumbar spine, with the three most common diagnoses making up greater than a third (37%) of the total. As the current largest study in professional ballet, the findings set the benchmark metrics for musculoskeletal injury to the foot, ankle, and lumbar spine sites. Future studies should aim to identify injury risk factors and modalities for prevention of these injuries.

Microinstability of the Hip and the Splits Radiograph.

A normal hip has a natural tendency toward stability because of both osseous and soft tissue structures. Hip motion is primarily rotational around a center of rotation. When the femoral head and its center of rotation translate, with or without rotation, the inherent stability of the femoroacetabular articulation may be lost. The spectrum of hip instability ranges from subtle microinstability to traumatic dislocation. Microinstability may be the cause or the effect of several other hip pathologies. Soft tissue contributions to stability include the static capsule, dynamic musculotendinous units, and underlying generalized connective tissue (eg, Ehlers-Danlos). Osseous contributions include multiple femoral and acetabular radiographic coverage parameters. Iatrogenic contributions include an unrepaired capsulotomy, overresection of the acetabular rim (iatrogenic dysplasia), overresection of cam osteochondroplasty, iliopsoas tenotomy, labral debridement, and ligamentum teres debridement. Patients with hip microinstability often have deep groin pain, exhibited by a C sign. These patients frequently participate in flexibility sports and activities, such as ballet, gymnastics, figure skating, and martial arts. On physical examination, generalized hypermobility syndromes should be assessed, as should loss of log-roll external rotation recoil, excessive abduction, trochanteric-pelvic impingement, and abductor fatigue. Standard imaging, including plain radiographs, magnetic resonance imaging, and computed tomography, should be analyzed for all causes of hip pain. A new plain radiograph, the splits radiograph is introduced here, consistently showing lateral femoral head translation and creation of a vacuum sign, showing hip microinstability. The splits radiograph is illustrated in a 22-year-old female dancer who presented with bilateral deep anterolateral groin pain.

Radiographic Prevalence of Dysplasia, Cam, and Pincer Deformities in Elite Ballet.

BACKGROUND: The demands of hip strength and motion in ballet are high. Hip disorders, such as cam and pincer deformities or dysplasia, may affect dance performance. However, the prevalence of these radiographic findings is unknown. PURPOSE: To determine the prevalence of radiographic cam and pincer deformities, borderline dysplasia, and dysplasia in a professional ballet company. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: An institutional review board-approved cross-sectional investigation of a professional ballet company was undertaken. Male and female adult dancers were eligible for inclusion. Four plain radiographs were obtained (standing anteroposterior pelvis, bilateral false profile, and supine Dunn 45°) and verified for adequacy. Cam and pincer deformities, dysplasia, borderline dysplasia, and osteoarthritis were defined. All plain radiographic parameters were measured and analyzed on available radiographs. Student t test, chi-square test (and Fisher exact test), and Spearman correlation analyses were performed to compare sexes, groups, and the effect of select radiographic criteria. RESULTS: A total of 47 dancers were analyzed (21 males, 26 females; mean age (±SD), 23.8 ± 5.4 years). Cam deformity was identified in 25.5% (24/94) of hips and 31.9% (15/47) of subjects, with a significantly greater prevalence in male dancers than females (48% hips and 57% subjects vs 8% hips and 12% subjects; P < .001 and P = .001, respectively). Seventy-four percent of subjects had at least 2 of 6 radiographic signs of pincer deformity. Male dancers had a significantly greater prevalence of both prominent ischial spine and posterior wall signs (P = .001 and P < .001, respectively), while female dancers had a significantly greater prevalence of coxa profunda (85% female hips vs 26% male hips; P < .001). Eighty-nine percent of subjects had dysplasia or borderline dysplasia in at least 1 hip (37% dysplastic), with a significantly greater prevalence of dysplasia or borderline dysplasia in female versus male dancers (92% female hips vs 74% male hips; P < .022). Further, in those with dysplasia or borderline dysplasia, 92% of female and 82% of male dancers had bilateral findings. CONCLUSION: In this professional ballet company, a high prevalence of radiographic abnormalities was found, including cam and pincer deformity and dysplasia. The results also revealed several sex-related differences of these abnormalities in this unique population. The long-term implications of these findings in this group of elite athletes remain unknown, and this issue warrants future investigation.