Is digital photography an accurate and precise method for measuring range of motion of the shoulder and elbow?

BACKGROUND: Accurate measurements of shoulder and elbow motion are required for the management of musculoskeletal pathology. The purpose of this investigation was to compare three techniques for measuring motion. The authors hypothesized that digital photography would be equivalent in accuracy and show higher precision compared to the other two techniques. METHODS: Using infrared motion capture analysis as the reference standard, shoulder flexion/abduction/internal rotation/external rotation and elbow flexion/extension were measured using visual estimation, goniometry, and digital photography on 10 fresh frozen cadavers. These measurements were performed by three physical therapists and three orthopaedic surgeons. Accuracy was defined by the difference from the reference standard (motion capture analysis), while precision was defined by the proportion of measurements within the authors' definition of clinical significance (10° for all motions except for elbow extension where 5° was used). Analysis of variance (ANOVA), t-tests, and chi-squared tests were used. RESULTS: Although statistically significant differences were found in measurement accuracy between the three techniques, none of these differences met the authors' definition of clinical significance. Precision of the measurements was significantly higher for both digital photography (shoulder abduction [93% vs. 74%, p < 0.001], shoulder internal rotation [97% vs. 83%, p = 0.001], and elbow flexion [93% vs. 65%, p < 0.001]) and goniometry (shoulder abduction [92% vs. 74%, p < 0.001] and shoulder internal rotation [94% vs. 83%, p = 0.008]) than visual estimation. Digital photography was more precise than goniometry for measurements of elbow flexion only [93% vs. 76%, p < 0.001]. CONCLUSIONS: There was no clinically significant difference in measurement accuracy between the three techniques for shoulder and elbow motion. Digital photography showed higher measurement precision compared to visual estimation for shoulder abduction, shoulder internal rotation, and elbow flexion. However, digital photography was only more precise than goniometry for measurements of elbow flexion. Overall digital photography shows equivalent accuracy to visual estimation and goniometry, but with higher precision than visual estimation.

Brake Reaction Time After Hip Arthroscopy for Femoroacetabular Impingement and Labral Tear.

PURPOSE: To determine if a difference exists in brake reaction time (BRT) before and after hip arthroscopy for femoroacetabular impingement (FAI) and labral tear compared with age- and gender-matched controls. METHODS: Consecutive adult subjects undergoing primary hip arthroscopy were eligible for this prospective investigation. Individuals with symptomatic FAI and labral tear that underwent hip arthroscopy with minimum 8 weeks follow-up were included. BRT was measured using the RT-2S reaction time tester a maximum of 6 weeks preoperatively and every 2 weeks postoperatively for 8 weeks. Sit-to-stand test (STST) was measured at each BRT testing session. An age- and gender-matched control group without hip or lower extremity symptoms were selected and completed both BRT and STST. Continuous pre- and postoperative BRT values were compared with Mann-Whitney and analyses of variance. Association of BRT and STST tests was performed with Spearman correlation. An a priori sample size calculation determined that minimally 18 subjects per group (surgery group vs control group) were necessary to detect, with 80% power (difference of 0.2 seconds in BRT). RESULTS: Nineteen subjects (age 37.1 ± 12.7 years, 10 women, 11 right hip) were analyzed. All subjects underwent arthroscopic labral repair and FAI correction. There was no difference between preoperative (604 ± 148 milliseconds [ms]) and postoperative (608 ms 2 weeks; 566 ms 4 weeks; 559 ms 6 weeks; 595 ms 8 weeks) BRT. There was no difference between controls and subjects at any time point. There was a strong negative correlation between BRT and STST preoperatively and at 4 and 6 weeks postoperatively and a moderate negative correlation at 2 weeks postoperatively. CONCLUSIONS: After hip arthroscopy for FAI and labral tear, BRT is not different from preoperative values or that of controls. In addition, BRT had a significant correlation with STST in the first 6 weeks after surgery. LEVEL OF EVIDENCE: Level II, diagnostic, prospective.

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.

Comparison of MRI, CT, Dunn 45° and Dunn 90° alpha angle measurements in femoroacetabular impingement.

PURPOSE: To determine if a significant difference existed among alpha angle measurements between 4 imaging techniques, axial oblique CT and MRI, Dunn 45° and Dunn 90° plain radiographs, in patients with symptomatic cam femoroacetabular impingement (FAI) and labral tear. METHODS: A single-surgeon prospective radiographic analysis of consecutive non-arthritic and non-dysplastic -patients with symptomatic FAI and labral tears who underwent surgery was performed. Alpha angle was measured using standard techniques as described by Nötzli. Cam morphology was defined via alpha angle measurement of >50.5 degrees. Group comparisons were made using ANOVA and chi-squared test. Sample size calculation was performed prior to study enrollment. RESULTS: 31 subjects (16 female; 33.5 ± 10.5 years mean age) were included. There was a significant difference in alpha angle measurements between all 4 imaging techniques (F [3,120] = 8.144; p<0.001), with the Dunn 45° view (66.3 ± 11.4°) significantly greater than all 3 other techniques (Dunn 90° [57.5 ± 10.7°; p = 0.015], MRI [53.3 ± 11.5°; p<0.001], and CT (54.9 ± 11.6°; p = 0.001). There was no significant difference in alpha angle between Dunn 90°, MRI, and CT. There was a significant difference in the observed number of hips with cam morphology between imaging techniques (χ2 9.4; p = 0.025). CONCLUSIONS: The Dunn 45° radiograph yielded a significantly higher alpha angle than Dunn 90°, axial oblique MRI, and CT imaging modalities. Use of the Dunn 90° or axial oblique MRI or CT as the threshold for cam osteoplasty may result in untreated symptomatic cam FAI. The authors recommend the Dunn 45° radiograph as the most sensitive evaluation of cam morphology.

How Does Level and Type of Experience Affect Measurement of Joint Range of Motion?

OBJECTIVES: Comparison of range of motion measurements by 3 types of investigators with different levels and types of training using three different measurement techniques. The study hypothesis was that the accuracy and precision of range of motion measurements would vary based on (1) the level and type of experience of the investigator and (2) the measurement technique used. DESIGN/SETTING: Descriptive laboratory study. PARTICIPANTS: Ten fresh frozen cadavers (20 upper and 20 lower extremities). INTERVENTIONS: Shoulder, elbow, hip, and knee motion were measured using 3 different measurement techniques (digital photography, goniometry, and visual estimation) by 3 groups of investigators (attending orthopedic surgeons, physical therapists, and residents). Accuracy was defined by the difference from the reference standard (motion capture analysis), whereas precision was defined by the proportion of measurements within either 5° or 10° of the reference standard. Analysis of variance, t-tests, and chi-squared tests were used. RESULTS: Statistically significant (p < 0.05) differences in accuracy were found for hip flexion, abduction, internal rotation, external rotation, and knee flexion. However, none of these differences met the authors' defined clinical significance (maximum difference 3°). Precision was significantly (p < 0.05) different for elbow extension, hip flexion, abduction, internal rotation, external rotation, and knee flexion. CONCLUSION: This study found that clinically accurate measurements of shoulder, elbow, hip, and knee motion are obtained regardless of technique used or the investigators' level and type of experience. Precision was equivalent for all shoulder motions, elbow flexion, and knee extension, but varied by as much as 7% to 28% between groups for all other motions.

Arthroscopic hip preservation surgery practice patterns: an international survey.

To design and conduct a survey analyzing pre-, intra- and post- hip arthroscopy practice patterns among hip arthroscopists worldwide. A 21-question, IRB-exempt, HIPAA-compliant, cross-sectional survey was conducted via email using SurveyMonkey to examine pre-operative evaluation, intra-operative techniques and post-operative management. The survey was administered internationally to 151 hip arthroscopists identified from publicly available sources. Seventy-five respondents completed the survey (151 ± 116 hip arthroscopy procedures per year; 8.6 ± 7.1 years hip arthroscopy experience). Standing AP pelvis, false profile and Dunn 45 were the most common radiographs utilized. CT scans were utilized by 54% of surgeons at least some of the time. Only 56% of participants recommended an arthrogram with MRI. Nearly all surgeons either never (40%) or infrequently (58%) performed arthroscopy in Tönnis grade-2 or grade-3 osteoarthritis. Surgeons rarely performed hip arthroscopy on patients with dysplasia (51% never; 44% infrequently). Only 25% of participants perform a routine 'T' capsulotomy and 41% close the capsule if the patient is at risk for post-operative instability. Post-operatively, 52% never use a brace, 39% never use a continuous passive motion, 11% never recommended heterotopic ossification prophylaxis and 30% never recommended formal thromboembolic disease prophylaxis. Among a large number of high-volume experienced hip arthroscopists worldwide, pre-, intra- and post- hip arthroscopy practice patterns have been established and reported. Within this cohort of respondents, several areas of patient evaluation and management remain discordant and controversial without universal agreement. Future research should move beyond expert opinion level V evidence towards high-quality appropriately designed and conducted investigations.

Is digital photography an accurate and precise method for measuring range of motion of the hip and knee?

BACKGROUND: Accurate measurements of knee and hip motion are required for management of musculoskeletal pathology. The purpose of this investigation was to compare three techniques for measuring motion at the hip and knee. The authors hypothesized that digital photography would be equivalent in accuracy and show higher precision compared to the other two techniques. METHODS: Using infrared motion capture analysis as the reference standard, hip flexion/abduction/internal rotation/external rotation and knee flexion/extension were measured using visual estimation, goniometry, and photography on 10 fresh frozen cadavers. These measurements were performed by three physical therapists and three orthopaedic surgeons. Accuracy was defined by the difference from the reference standard, while precision was defined by the proportion of measurements within either 5° or 10°. Analysis of variance (ANOVA), t-tests, and chi-squared tests were used. RESULTS: Although two statistically significant differences were found in measurement accuracy between the three techniques, neither of these differences met clinical significance (difference of 1.4° for hip abduction and 1.7° for the knee extension). Precision of measurements was significantly higher for digital photography than: (i) visual estimation for hip abduction and knee extension, and (ii) goniometry for knee extension only. CONCLUSIONS: There was no clinically significant difference in measurement accuracy between the three techniques for hip and knee motion. Digital photography only showed higher precision for two joint motions (hip abduction and knee extension). Overall digital photography shows equivalent accuracy and near-equivalent precision to visual estimation and goniometry.

Lower thoracic rib stress fractures in baseball pitchers.

Stress fractures of the first rib on the dominant throwing side are well-described in baseball pitchers; however, lower thoracic rib fractures are not commonly recognized. While common in other sports such as rowing, there is scant literature on these injuries in baseball. Intercostal muscle strains are commonly diagnosed in baseball pitchers and have a nearly identical presentation but also a highly variable healing time. The diagnosis of a rib stress fracture can predict a more protracted recovery. This case series presents two collegiate baseball pitchers on one team during the same season who were originally diagnosed with intercostal muscle strains, which following magnetic resonance imaging (MRI) were found to have actually sustained lower thoracic rib stress fractures. The first sustained a stress fracture of the posterior aspect of the right 8th rib on the dominant arm side, while the second presented with a left-sided 10th rib stress fracture on the nondominant arm side. In both cases, MRI was used to visualize the fractures as plain radiographs are insensitive and commonly negative early in patient presentation. Patients were treated with activity modification, and symptomatic management for 4-6 weeks with a graduated return to throwing and competition by 8-10 weeks. The repetitive high stresses incurred by pitching may cause either dominant or nondominant rib stress fractures and this should be included in the differential diagnosis of thoracic injuries in throwers. It is especially important that athletic trainers and team physicians consider this diagnosis, as rib fractures may have a protracted course and delayed return to play. Additionally, using the appropriate imaging techniques to establish an accurate diagnosis can help inform return-to-play decisions, which have important practical applications in baseball, such as roster management and eligibility.

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.

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.

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).