Long-term Outcomes of Complete Tears of the Distal Biceps Tendon: An Analysis of Surgical Management at a Median Follow-up of 14.7 Years.

Background: Surgical repair of full thickness biceps tears has demonstrated adequate outcomes in short and mid-term studies. However, data on the long-term outcomes of full thickness distal biceps injuries and their treatment are currently lacking. Purpose/Hypothesis: The purpose of this study was to report on patient demographics, injury characteristics, and long-term outcomes for patients with full-thickness distal biceps tears. It was hypothesized that complete distal biceps tears managed operatively would demonstrate robust clinical success at long-term follow-up. Study Design: Case series; Level of evidence, 4. Methods: Patients with magnetic resonance imaging-confirmed, complete distal biceps tendon rupture sustained between 1996 and 2016 were identified. Patients were cross-referenced with a regional geographic database. Results: A total of 66 patients (3 female, 63 male) with a median age of 50.8 years (IQR, 41.5-60.4) and a median clinical follow-up of 14.7 years (IQR, 9.6-17.9 years) were included. Patients who sustained a full-thickness distal biceps tendon tear were likely to be in their early 50s, male, right-hand dominant, current/former smokers, and laborers with a history of traumatic injury during an intentional movement. Most of these patients had pain and supination weakness but no loss of range of motion. All included tears were treated operatively. At final follow-up, patients maintained a majority of near-normal range of motion (median total arc of flexion/extension 140° and supination/pronation 80°), excellent elbow flexion strength (91% of patients had full strength), and adequate elbow supination strength (76% of patients had full strength). The overall complication rate was 24%, with 16 out of 66 patients experiencing some type of complication between infection, rerupture, heterotopic ossification, reoperation, and nerve complications. Overall return to work was 98%, and 85% of those who returned to work did so without restrictions. Conclusion: Complete tears of the distal biceps were most common in patients 50 years of age, male sex, right-hand dominant, and current/former smokers. The most common profession was laborer, and injuries were primarily traumatic in nature during intentional activity. Patients managed operatively demonstrated high rates of success at long-term follow-up with respect to elbow function and clinical outcomes.

Radiographic and Advanced Imaging Evaluation of Posterior Shoulder Instability.

PURPOSE OF REVIEW: Posterior shoulder instability is an uncommon but important cause of shoulder dysfunction and pain which may occur as the result of seizure, high energy trauma, or repetitive stress related to occupational or sport-specific activities. This current review details the imaging approach to the patient with posterior shoulder instability and describes commonly associated soft tissue and bony pathologies identified by radiographs, CT, and MR imaging. RECENT FINDINGS: Advances in MR imaging technology and techniques allow for more accurate evaluation of bone and soft tissue pathology associated with posterior shoulder instability while sparing patients exposure to radiation. Imaging can contribute significantly to the clinical management of patients with posterior shoulder instability by demonstrating the extent of associated injuries and identifying predisposing anatomic conditions. Radiologic evaluation should be guided by clinical history and physical examination, beginning with radiographs followed by CT and/or MRI for assessment of osseous and soft tissue pathology. Synthesis of a patient's clinical history, physical exam findings, and radiologic examinations should guide clinical management.

Retrospective evaluation of MRI findings in arthroscopically confirmed cases of hypermobile lateral meniscus.

OBJECTIVE: To identify preoperative MRI findings in patients with arthroscopically confirmed hypermobile lateral meniscus utilizing a standard MRI knee protocol, with comparison to normal control and lateral meniscal tear groups. SUBJECTS AND METHODS: All patients with arthroscopically confirmed hypermobile lateral meniscus diagnosed at our institution were retrospectively identified. The following structures were evaluated on preoperative knee MRIs: superior and inferior popliteomeniscal fascicles, lateral meniscus and meniscocapsular junction, popliteal hiatus, and soft tissue edema around the popliteal hiatus. The same MRI features were evaluated in the normal control and lateral meniscal tear groups. RESULTS: Study, normal control, and lateral meniscal tear patients (18 each) were included. In the study group, 94.4% had superior popliteomeniscal fascicle abnormality, 89.0% had inferior popliteomeniscal fascicle abnormality, and 72.2% had lateral meniscal abnormality. Incidence of these abnormalities was significantly higher than in the normal control group. Meniscal abnormalities in the study group all involved the posterior horn meniscocapsular junction, 12/13 of which had vertical signal abnormality at the junction and 1/13 with anterior subluxation of the entire posterior horn. Popliteus hiatus measurements were largest in the lateral meniscal tear group. CONCLUSION: In patients with hypermobile lateral meniscus, the combination of popliteomeniscal fascicle abnormality and vertical signal abnormality at the meniscocapsular junction was seen in the majority of patients. Popliteomeniscal fascicle signal abnormality without identifiable lateral meniscal injury was the next most common imaging appearance. Radiologists may provide valuable information by suggesting the diagnosis of hypermobile lateral meniscus in such cases.

Management of Partial-Thickness Tears of the Distal Bicep Tendon: Evaluation of 111 Patients With 10-Year Follow-up.

Background: There is a paucity of research on the management of partial-thickness tears of the distal bicep tendon, and even less is known about the long-term outcomes of this condition. Purpose: To identify patients with partial-thickness distal bicep tendon tears and determine (1) patient characteristics and treatment strategies, (2) long-term outcomes, and (3) any identifiable risk factors for progression to surgery or complete tear. Study Design: Case-control study; Level of evidence, 3. Methods: A fellowship-trained musculoskeletal radiologist identified patients diagnosed with a partial-thickness distal bicep tendon tear on magnetic resonance imaging between 1996 and 2016. Medical records were reviewed to confirm the diagnosis and record study details. Multivariate logistic regression models were created using baseline characteristics, injury details, and physical examination findings to predict operative intervention. Results: In total, 111 patients met inclusion criteria (54 treated operatively, 57 treated nonoperatively), with 53% of tears in the nondominant arm and a mean follow-up time after surgery of 9.7 ± 6.5 years. Only 5% of patients progressed to full-thickness tears during the study period, at a mean of 35 months after the initial diagnosis. Patients who were nonoperatively treated were less likely to miss time from work (12% vs 61%; P < .001) and missed fewer days (30 vs 97 days; P < .016) than those treated surgically. Multivariate regression analyses demonstrated increased risk of progression to surgery with older age at initial consult (unit odds ratio [OR], 1.1), tenderness to palpation (OR, 7.5), and supination weakness (OR, 24.8). Supination weakness at initial consult was a statistically significant predictor for surgical intervention (OR, 24.8; P = .001). Conclusion: Clinical outcomes were favorable for patients regardless of treatment strategy. Approximately 50% of patients were treated surgically; patients with supination weakness were 24 times more likely to undergo surgery than those without. Progression to full-thickness tear was a relatively uncommon reason for surgical intervention, with only 5% of patients progressing to full-thickness tears during the study period and the majority occurring within 3 months of initial diagnosis.

Association Between Transtibial Meniscus Root Repair and Rate of Meniscal Healing and Extrusion on Postoperative Magnetic Resonance Imaging: A Prospective Multicenter Study.

BACKGROUND: Prospective studies evaluating second-look imaging of meniscus root repair using a transtibial pull-out technique are limited; therefore, optimal surgical indications and the technique for meniscus root repair remain uncertain. HYPOTHESIS: It was hypothesized that there would be a high rate of healing, improvement in meniscal extrusion, and prevention of articular cartilage degeneration and subchondral bone abnormalities after meniscus root repair. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Consecutive patients undergoing transtibial root repair were prospectively enrolled at 2 orthopaedic centers between March 2017 and January 2019. Pre- and postoperative magnetic resonance imaging (MRI) scans were reviewed by a musculoskeletal radiologist in a blinded fashion for meniscal healing, quantification of extrusion, articular cartilage grade, subchondral bone changes, and coronary/meniscotibial ligament abnormalities. Given persistent extrusion observed on postoperative MRI scans, an additional 10 patients gave consent and were enrolled for immediate (before weightbearing) postoperative MRI scans. RESULTS: A total of 45 patients (16 male, 29 female; mean ± standard deviation age, 42.3 ± 12.9 years; body mass index, 31.6) were prospectively enrolled in the study; there were 47 meniscus root repairs: 29 medial and 18 lateral (2 with both). Postoperative MRI was obtained at an average of 6.3 months (range, 5.1-8 months); 98% of meniscal repairs had evidence of healing. Mean extrusion increased significantly, from 1.9 ± 1.5 mm preoperatively to 2.6 ± 1.4 mm postoperatively (P = .03). There was no significant progression of chondromalacia grade, subchondral edema, insufficiency fracture, subchondral cysts, or subchondral collapse. In the additional 10-patient cohort, the mean preoperative extrusion (1.6 ± 1.2 mm) was not significantly different from that immediately postoperatively (2.0 ± 1.0 mm; P = .23). CONCLUSION: Prospective MRI analysis of transtibial meniscus root repair confirmed a high rate of meniscal healing and no observable progression of cartilage degeneration or subchondral bone abnormalities at the short-term follow-up. However, meniscal extrusion worsened in the first 6 months after surgery. REGISTRATION: NCT03037242 (ClinicalTrials.gov identifier).

A Case of Medial Tibial Crest Friction Syndrome: A Rare Cause of Medial Knee Pain.

ABSTRACT: Knee pain is among the most common problems in active patients, with common causes of medial knee pain including meniscal injury, osteoarthritis, medial collateral ligament (MCL) injury, and pes anserine bursopathy/distal hamstring tendinopathy. Some cases of medial knee pain are refractory to standard treatment options and may be caused by rare pathology. We present a case of medial knee pain secondary to medial tibial crest friction syndrome (MTCFS) in a 22-year-old male training for a sprint triathlon after rapidly increasing his training program. Magnetic resonance imaging revealed bone marrow and soft-tissue edema about the MTC deep to the MCL consistent with MTCFS. The patient failed a period of relative rest and activity modification, but improved with corticosteroid injection deep to the MCL in the location of his symptoms. This case highlights a potential management option for MTCFS, a disorder previously described only in radiologic literature.

To Be or Not to Be (A Morton's/Interdigital Neuroma): That Is the Question-A Case Series of Lateral Forefoot Pain Localized to the Proper Digital Nerve of the Fifth Toe.

ABSTRACT: We present 2 cases where the initial history and examination were similar to a Morton's/interdigital neuroma. In both cases, however, diagnostic ultrasound revealed symptomatic snapping of the proper digital nerve of the fifth toe. The anatomy of the proper digital nerve of the fifth toe may predispose it to a snapping phenomenon. Clinical awareness of this atypical cause of forefoot pain can help guide the diagnosis and treatment in those patients with persistent and refractory lateral forefoot pain and paresthesias.

The Difference in Medial Meniscal Extrusion between Non-Weight-Bearing and Weight-Bearing Positions in People with and without Medial Compartment Knee Osteoarthritis.

BACKGROUND: Medial meniscal extrusion (MME) has been correlated with medial meniscal injury and progression of medial knee osteoarthritis (OA). OBJECTIVE: To examine the difference in MME between non-weight-bearing (supine) and weight-bearing (standing) positions in patients with and without medial knee OA. Determine the correlation between body mass index (BMI), Kellgren-Lawrence (KL) grade, Knee Osteoarthritis Outcome Score (KOOS), and MME. DESIGN: Prospective. SETTING: Tertiary institution PM&R Department. PARTICIPANTS: Forty five participants (29 female, 16 male), 24 with healthy knees and 21 with OA. METHODS OR INTERVENTIONS: A single physician sonographer measured supine and standing MME with ultrasound (US) on each participant. The physician was blinded to all measurements. BMI was recorded on all participants. KL grades and KOOS questionnaires were obtained for the OA group. MAIN OUTCOME MEASURES: MME in supine and standing positions, change in MME from supine to standing, BMI, KL grade, and KOOS subscale scores. RESULTS: MME increased .52 mm from supine to standing (P < .001). MME was greater in the OA group in both the supine (P = .002) and standing (P < .001) positions. Increasing BMI was moderately correlated with increasing MME (supine P = .001, standing <.001). Increasing age was correlated with increasing MME (supine P = .012, standing P = .002). Increasing KL grade (from 1 to 4) was correlated with increasing MME (supine P = .015, standing = .006). There was a small-to-moderate correlation between KOOS activities of daily living (ADL) subscale score and change in MME from supine to standing (P = .035). The change in MME from supine to standing positions had a small-to-moderate correlation (P = .035) with KOOS ADL subscale score alone but did not correlate with any of the other KOOS subscale scores or KOOS total scores. Receiver operating characteristic curve analysis suggested a standing MME value of 4.2 mm provides a positive likelihood ratio of 6.02 for knee OA. CONCLUSIONS: MME is greater in those with OA and with weight-bearing. MME correlates with BMI, age, KL grade, and the KOOS ADL subscale score. Finally, standing MME of 4.2 mm yielded a higher positive likelihood ratio to differentiate between healthy knees and those with medial compartment OA than the previously reported value of 3.0 mm.

Investigating the Chronology of Meniscus Root Tears: Do Medial Meniscus Posterior Root Tears Cause Extrusion or the Other Way Around?

BACKGROUND: Meniscus root tears are increasingly being recognized. Meniscal extrusion has previously been associated with medial root tears; however, the relationship between secondary meniscal restraints, such as the meniscotibial (MT) ligament, extrusion, and root tears has yet to be formally evaluated. PURPOSE: To better understand the association between MT ligament competence, medial meniscal extrusion, and medial meniscus posterior root tears (MMPRTs) as well as to determine the progression of meniscal extrusion over time. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Serial magnetic resonance imaging (MRI) scans were reviewed for patients who showed evidence of medial meniscal extrusion and MMPRTs on at least 1 of ≥2 available MRI scans. All patients were symptomatic at the time of diagnosis. All MRI scans were analyzed independently by 2 board-certified musculoskeletal radiologists. MT ligament disruption, medial meniscal extrusion, and MMPRTs were recorded for each MRI scan. The time between MRI scans, presence of insufficiency fractures, and Outerbridge classification for the medial femur and tibia were also evaluated. RESULTS: Overall, 27 knees in 26 patients were included in this study, with a total of 63 MRI scans analyzed (21 knees with 2 MRI scans, 3 with 3 MRI scans, and 3 with 4 MRI scans). All patients demonstrated clear medial meniscal extrusion and MT ligament disruption before the subsequent development of MMPRTs (P < .001). Mean extrusion at the time of initial MRI was 3.3 ± 1.1 mm and increased significantly to 5.5 ± 1.8 mm at the time of first imaging with an identified MMPRT (P < .001). The mean time between initial MRI and the first identification of an MMPRT on later MRI was 1.7 ± 1.6 years. CONCLUSION: In a sample of 27 symptomatic knees with serial MRI scans both before and after an MMPRT diagnosis, all patients demonstrated MT ligament disruption and associated meniscal extrusion before the development of subsequent medial meniscus root tears. These findings suggest that MT ligament disruption and medial meniscal extrusion represent early and predisposing events contributing to MMPRTs. Therefore, this provides a possible explanation of why meniscal extrusion is not corrected with medial meniscus root repair.

Isolated meniscus extrusion associated with meniscotibial ligament abnormality.

PURPOSE: The purpose of this study was to describe meniscus extrusion, present imaging characteristics, and provide clinical correlations for patients with isolated meniscus extrusion. METHODS: Of the 3244 MRI reports identified as having meniscus extrusion, 20 patients were identified to have isolated meniscus extrusion (0.62%). Patients with moderate to severe chondromalacia, meniscus tears, intra-articular fractures, tumours, and ligament tears were excluded. Radiographs were reviewed and graded using Kellgren-Lawrence (K-L) scores. MRI's were reviewed for the extent of extrusion and whether or not the meniscotibial ligament was intact. Clinical presentation and management were recorded. RESULTS: The study population consisted of 12 females and 8 males with a mean age of 40.5, diagnosed with meniscus extrusion and minimal concomitant knee pathology. 68% of patients were considered symptomatic as their knee pain correlated with the side of their meniscus extrusion and no other reason for pain was identified. The mean amount of meniscus extrusion was 2.5 mm (SD ± 1.1 mm) with 45% (9 of 20) having 3 + mm of extrusion. Meniscotibial ligament abnormality was identified in 65% of cases (13 of 20). Patients with 3 + mm of meniscus extrusion were much more likely to have associated meniscotibial ligament abnormality (100%, 9 of 9) compared to those with < 3 mm of extrusion (36%, 4 of 11) (RR 2.75, p = 0.048). The mean K-L grade obtained at the initial visit was 0.9 (95% CI 0.7-1.4) and the mean K-L grade obtained on final follow-up was 1.3 (95% CI 0.8-2.8) (n.s.) at a mean of 44.7 months. No correlation was found between K-L grade, gender, age, acute injury, and BMI in relation to meniscotibial ligament abnormality or amount of meniscal extrusion. CONCLUSIONS: Meniscus extrusion often occurs in the presence of significant knee pathology, predominantly with meniscus tears or osteoarthritis. Isolated meniscus extrusion is a rare occurrence that may present clinically with knee pain, commonly to the side in which the extrusion occurs. In patients with three or more millimetres of meniscus extrusion, an intact meniscus and minimal knee pathology, meniscotibial ligament abnormality is likely. This may provide an opportunity to treat the meniscotibial ligament abnormality with meniscus centralisation technique and decrease the amount of meniscus extrusion.

Ultrasound Assessment of Weight-Bearing and Non-Weight-Bearing Meniscal Extrusion: A Reliability Study.

BACKGROUND: Ultrasound has become a useful instrument in evaluating musculoskeletal pathology. Recent studies suggest that ultrasound imaging of weight-bearing menisci may enhance the assessment of knee pathology, such as osteoarthritis (OA) and meniscal injuries. OBJECTIVE: The primary aim of this study was to determine the intrarater and interrater reliability of ultrasound measurements of medial meniscal extrusion (MME) after a brief training session. DESIGN: Prospective reliability study. SETTING: Physical medicine and rehabilitation (PM&R) department within a tertiary care institution. PARTICIPANTS: Forty-five participants (29 female, 16 male) were recruited to serve as models, 24 of whom had healthy knees and 21 of whom had radiographically confirmed medial compartment knee OA. Three physician sonographers (1 = experienced, 1 = sports medicine fellow, 1 = post-graduate year [PGY]-4 PM&R resident) were recruited to serve as operators. METHODS OR INTERVENTIONS: Operators received a brief training session on identifying and measuring MME. All operators measured bilateral MME in each model in the standing and supine positions on two separate days. Operators were blinded to all measurements. MAIN OUTCOME MEASUREMENTS: Primary outcomes were inter- and intrarater intraclass correlation coefficients (ICCs) of MME measurements among operators with different levels of ultrasound experience. RESULTS: Supine MME intrarater reliability ICCs were 0.927, 0.885, and 0.780 for the experienced physician, sports medicine fellow, and PGY-4 operators, respectively. Standing MME intrarater reliability ICCs were 0.941, 0.902, and 0.824 for the experienced physician, sports medicine fellow, and PGY-4 operators, respectively. Interrater reliability ICCs were 0.896 and 0.842 for supine and standing measurements, respectively. There was a statistically significant increase in intrarater reliability with experience between the PGY-4 resident and experienced physician operators. CONCLUSIONS: Operators with different levels of ultrasound experience demonstrated good MME measurement intra- and interrater reliabilities in both supine and standing positions.

Can a Brief Training Session Prepare Physician Sonographers of Differing Experience to Measure the Ischiofemoral Space? A Reliability Study.

OBJECTIVE: The primary aim of this study was to determine the inter- and intrarater reliability of ultrasound (US) measurements of the ischiofemoral space (IFS) following a brief training session. A secondary aim was to determine if reliability correlated with sonographer experience. DESIGN: Prospective cohort study. SETTING: Physical medicine and rehabilitation department within a tertiary care institution. PARTICIPANTS: Seven male and 3 female individuals were recruited to serve as models. Nine physician sonographers (3 postgraduate year [PGY]-2 residents, 3 PGY-4 residents, 3 physicians) were recruited to serve as sonographers. METHODS OR INTERVENTIONS: Sonographers received a 15-minute educational session on identifying the IFS with US, followed by 20 minutes of practice. Models were then placed in a prone position and secured to prevent hip movement. All operators measured bilateral IFSs in each model twice with a washout period between measurements. Operators were blinded to all measurements. MAIN OUTCOME MEASURES: Primary outcomes were inter- and intrarater reliability interclass coefficients (ICCs) of IFS measurements among the groups with different levels of US experience. Secondary outcomes included comparisons of inter- and intrarater reliability ICCs of IFS measurements between groups, and the difference of mean IFS measurements between groups. RESULTS: Intrarater reliability ICCs were 0.829, 0.680, and 0.596 for physician, PGY-4, and PGY-2 groups, respectively. Interrater reliability ICCs were 0.722, 0.427, and 0.558 for physician, PGY-4, and PGY-2 groups, respectively. No statistically significant differences in reliability were identified between groups. Mean IFS measurements were 31.2, 33.4, and 34.0 mm for physician, PGY-4, and PGY-2 groups, respectively. Physician measurements were significantly smaller than the PGY-4 and PGY-2 measurements (P < .049 and P < .01). CONCLUSIONS: Following a brief training session, experienced sonographers demonstrated excellent IFS measurement intrarater reliability, whereas PGY-4 and PGY-2 sonographers demonstrated fair intrarater reliability. All sonographers demonstrated fair interrater reliability. LEVEL OF EVIDENCE: II.

Recurrent Brachial Neuritis Attacks in Presentation of B-Cell Lymphoma.

We describe a 51-year-old woman who over 5 years had 9 painful monophasic attacks affecting the brachial plexus before a fascicular plexus biopsy diagnosed large B-cell lymphoma. The initial attacks were responsive to steroids with clinical resolution. At last attack, magnetic resonance imaging showed multifocal T2 hyperintensities and nodular gadolinium enhancement in the right brachial plexus not seen previously. Also seen were similar changes in the thoracic spinal cord, basal ganglia, cerebellum, and brainstem. Positron emission tomography revealed marked hypermetabolic activity of the plexus facilitating targeted fascicular brachial plexus biopsy, making the pathological diagnosis. Neurolymphomatosis affecting the peripheral nervous system typically presents with insidious painful progressive infiltration of nerves, roots, or plexi. Recurrent idiopathic brachial neuritis attacks (ie, Parsonage-Turner syndrome) in contrast most commonly are seen in persons with a family history and a discoverable genetic cause by SEPT9 mutations, which tested negative in this patient. This case illustrates how neurolymphomatosis, which represents a malignant transformation of B cells within peripheral nerves, can sometimes present with paraneoplastic immune-responsive neuritis mimicking Parsonage-Turner syndrome. Recurrence, an immune-refractory course or insidious progressive involvement of the nervous system, should raise suspicion of neurolymphomatosis.

Variability of ischiofemoral space dimensions with changes in hip flexion: an MRI study.

OBJECTIVE: The primary aim of this study was to determine if ischiofemoral space (IFS) dimensions vary with changes in hip flexion as a result of placing a bolster behind the knees during magnetic resonance imaging (MRI). A secondary aim was to determine if IFS dimensions vary between supine and prone hip neutral positions. DESIGN: The study employed a prospective design. SETTING: Sports medicine center within a tertiary care institution. PARTICIPANTS: Five male and five female adult subjects (age mean = 29.2, range = 23-35; body mass index [BMI] mean = 23.5, range = 19.5-26.6) were recruited to participate in the study. METHODS: An axial, T1-weighted MRI sequence of the pelvis was obtained of each subject in a supine position with their hips in neutral and flexed positions, and in a prone position with their hips in neutral position. Supine hip flexion was induced by placing a standard, 9-cm-diameter MRI knee bolster under the subject's knees. The order of image acquisition (supine hip neutral, supine hip flexed, prone hip neutral) was randomized. The IFS dimensions were then measured on a separate workstation. The investigator performing the IFS measurements was blinded to the subject position for each image. MAIN OUTCOME MEASUREMENTS: The main outcome measurements were the IFS dimensions acquired with MRI. RESULTS: The mean IFS dimensions in the prone position were 28.25 mm (SD 5.91 mm, standard error mean 1.32 mm). In the supine hip neutral position, the IFS dimensions were 25.1 (SD 5.6) mm. The mean difference between the two positions of 3.15 (3.6) mm was statistically significant (95 % CI of the difference = 1.4 to 4.8 mm, t19 = 3.911, p = .001). The mean IFS dimensions in the hip flexed position were 36.9 (SD 5.7) mm. The mean difference between the two supine positions of 11.8 (4.1) mm was statistically significant (95 % CI of the difference = 9.9 to 13.7 mm, t19 = 12.716, p < .001). CONCLUSIONS: Our findings demonstrate that the IFS measurements obtained with MRI are dependent upon patient positioning with respect to hip flexion and supine versus prone positions. This finding has implications when evaluating for ischiofemoral impingement, an entity resulting in hip and/or buttock pain secondary to impingement of the quadratus femoris muscle within a pathologically narrowed IFS. One will need to account for patient hip flexion and supine versus prone positioning when evaluating individuals with suspected ischiofemoral impingement.

Can Ultrasound Accurately Assess Ischiofemoral Space Dimensions? A Validation Study.

BACKGROUND: Ischiofemoral impingement is a potential cause of hip and buttock pain. It is evaluated commonly with magnetic resonance imaging (MRI). To our knowledge, no study previously has evaluated the ability of ultrasound to measure the ischiofemoral space (IFS) dimensions reliably. OBJECTIVE: To determine whether ultrasound could accurately measure the IFS dimensions when compared with the gold standard imaging modality of MRI. DESIGN: A methods comparison study. SETTING: Sports medicine center within a tertiary-care institution. PARTICIPANTS: A total of 5 male and 5 female asymptomatic adult subjects (age mean = 29.2 years, range = 23-35 years; body mass index mean = 23.5, range = 19.5-26.6) were recruited to participate in the study. METHODS: Subjects were secured in a prone position on a MRI table with their hips in a neutral position. Their IFS dimensions were then acquired in a randomized order using diagnostic ultrasound and MRI. MAIN OUTCOME MEASUREMENTS: The main outcome measurements were the IFS dimensions acquired with ultrasound and MRI. RESULTS: The mean IFS dimensions measured with ultrasound was 29.5 mm (standard deviation [SD] 4.99 mm, standard error mean 1.12 mm), whereas those obtained with MRI were 28.25 mm (SD 5.91 mm, standard error mean 1.32 mm). The mean difference between the ultrasound and MRI measurements was 1.25 mm, which was not statistically significant (SD 3.71 mm, standard error mean 3.71 mm, 95% confidence interval -0.49 mm to 2.98 mm, t19 = 1.506, P = .15). The Bland-Altman analysis indicated that the 95% limits of agreement between the 2 measurement was -6.0 to 8.5 mm, indicating that there was no systematic bias between the ultrasound and MRI measurements. CONCLUSIONS: Our findings suggest that the IFS measurements obtained with ultrasound are very similar to those obtained with MRI. Therefore, when evaluating individuals with suspected ischiofemoral impingement, one could consider using ultrasound to measure their IFS dimensions. LEVEL OF EVIDENCE: III.

Incidence of associated knee injury in pediatric tibial eminence fractures.

Our intent is to review pediatric tibial eminence fractures treated at a Level I Trauma Center and to note the incidence of associated knee pathology. All pediatric patients treated operatively for a tibial eminence fracture over a 10-year period were identified. A chart review was performed to identify patient demographics, injury pattern, presence of associated pathology, and magnetic resonance imaging (MRI) findings. In our series of 20 pediatric tibial eminence fractures, 6 patients had associated meniscal tears. Meniscal tears occurred more commonly in type III injuries (5 of 13) than type II injuries (1 of 6). Two patients sustained associated ligamentous injury; there were no patients with associated chondral defects. A displaced pediatric tibial eminence fracture is a relatively infrequent injury. The incidence of associated meniscal injury in our study was 30%, and associated ligamentous injury was uncommon. Arthroscopic evaluation before definitive treatment of displaced tibial eminence fractures should be considered given the associated incidence of meniscal tears. MRI does not appear to provide additional information if arthroscopic treatment is pursued. This study is level IV, case series.

Femoroacetabular impingement in former high-level youth soccer players.

BACKGROUND: Femoroacetabular impingement (FAI) can be a source of hip pain in young adults. Repetitive kicking associated with youth soccer may lead to morphologic changes of the proximal femur that predispose a person to the development of FAI. HYPOTHESIS: Young adults who participated in high-level soccer competition as youths are more likely to demonstrate radiographic changes consistent with FAI and to have increased alpha angles as compared with controls. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Pelvic radiographs (anteroposterior and frog-lateral) were obtained on 50 individuals who participated in high-level soccer during skeletal immaturity and 50 controls who did not participate in high-level soccer. There were 25 men and 25 women in each group. All subjects were between 18 and 30 years of age, had a body mass index of less than 30, and had not sought or received treatment for hip disorders. Radiographs were analyzed independently for the presence of FAI, and alpha angles were measured. Hips with alpha angles that measured greater than or equal to 55° were deemed to have cam deformity. RESULTS: Fifteen of the 25 male subjects had evidence of cam deformity, compared with 14 male controls. Nine of the 25 female subjects had evidence of cam deformity, compared with 8 female controls. Neither of these differences was statistically significant. There was a significantly higher prevalence of cam deformity in men as compared with women (29 vs 17, P = .016). CONCLUSION: Participation in high-level soccer during skeletal immaturity is not associated with a higher risk of development of cam deformity in the young adult years. There is a high prevalence of cam deformity in the young adult population. Males demonstrate a higher prevalence of cam deformity than do females.

Comparison of FRPE and human embryonic stem cell-derived RPE behavior on aged human Bruch's membrane.

PURPOSE: To compare RPE derived from human embryonic stem cells (hES-RPE) and fetal RPE (fRPE) behavior on human Bruch's membrane (BM) from aged and AMD donors. METHODS: hES-RPE of 3 degrees of pigmentation and fRPE were cultured on BM explants. Explants were assessed by light, confocal, and scanning electron microscopy. Integrin mRNA levels were determined by real-time polymerase chain reaction studies. Secreted proteins in media were analyzed by multiplex protein analysis after 48-hour exposure at culture day 21. RESULTS: hES-RPE showed impaired initial attachment compared to fRPE; pigmented hES-RPE showed nuclear densities similar to fRPE at day 21. At days 3 and 7, hES-RPE resurfaced BM to a limited degree, showed little proliferation (Ki-67), and partial retention of RPE markers (MITF, cytokeratin, and CRALBP). TUNEL-positive nuclei were abundant at day 3. fRPE exhibited substantial BM resurfacing at day 3 with decreased resurfacing at later times. Most fRPE retained RPE markers. Ki-67-positive nuclei decreased with time in culture. TUNEL staining was variable. Increased integrin mRNA expression did not appear to affect cell survival at day 21. hES-RPE and fRPE protein secretion was similar on equatorial BM except for higher levels of nerve growth factor and thrombospondin-2 (TSP2) by hES-RPE. On submacular BM, fRPE secreted more vascular endothelial growth factor (VEGF), brain-derived neurotrophic factor, and platelet-derived growth factor; hES-RPE secreted more TSP2. CONCLUSIONS: Although pigmented hES-RPE and fRPE resurfaced aged and AMD BM to a similar, limited degree at day 21, cell behavior at earlier times was markedly dissimilar. Differences in protein secretion may indicate that hES-RPE may not function identically to native RPE after seeding on aged or AMD BM.