End Vertebra Versus Apical Vertebra: Where Are We More Likely to Misplace in Spine Deformity?

BACKGROUND DATA: Pedicle screws placement remains technically demanding. The thoracic curve apex is considerably difficult due to its unique morphology and severe rotation. In comparison the upper end vertebrae have smaller pedicles and limited soft tissue exposure. This study seeks to evaluate the likelihood of screw misplacement at the end vertebra and apex. METHODS: A retrospective review of preoperative and postoperative computed tomographic (CT) scans of spinal deformity patients who underwent posterior spinal fusion with pedicle screw constructs between 2004 and 2011 was performed. Pedicles located at the upper instrumented vertebra (UIV) and lower instrumented vertebra (LIV), and the major and minor apices were evaluated. Pedicle morphology was studied on preoperative CT and screw placement on postoperative CT. RESULTS: In total, 188 patients met the inclusion criteria, 172 had preoperative CT scans and 133 had postoperative CT scans. The UIV had a significantly lower percentage of normal pedicles (type A) compared with apex major, apex minor, or LIV (59.1% vs. 76.1% vs. 77.3% vs. 98.7%; P<0.001). UIV had significantly the lowest percentage of normal normally placed screws compared with LIV, apex major, or apex minor (69.4% vs. 97.3% vs. 87.6% vs. 92.1%; P<0.001). In a logistic regression adjusted for preoperative Cobb angles, UIV was more likely to have screws misplaced (odds ratio =7.56; 95% confidence interval, 4.01-14.30; P<0.001) and abnormal pedicles (odds ratio=2.81; 95% confidence interval, 1.52-5.19; P=0.001) compared with any other location studied. In abnormal pedicles, 41 (39.8%) of the 103 UIV screws were misplaced, whereas 10 (16.4%) of the 61 apex major, apex minor, or LIV screws were misplaced (P=0.007). CONCLUSIONS: The UIV presents more of a risk for pedicle screw misplacement and abnormal morphology when compared with LIV and apical vertebra. We believe these findings can aid in the surgeon's preoperative and intraoperative management to ensure increased success in accurate and safe pedicle screw placement. LEVEL OF EVIDENCE: Level III.

Survey of current trends in postgraduate musculoskeletal ultrasound education in the United States.

OBJECTIVE: To determine current trends in postgraduate musculoskeletal ultrasound education across various medical specialties in the United States. MATERIALS AND METHODS: A survey regarding musculoskeletal ultrasound education was sent to all program directors for diagnostic radiology and physical medicine rehabilitation residency programs, as well as adult rheumatology and sports medicine fellowship programs in the United States. The survey, sent in July 2015, queried the presence of formal musculoskeletal ultrasound training, the components of such training and case volume for trainees. RESULTS: Response rates were 23, 25, 28 and 33% for physical medicine and rehabilitation, radiology, rheumatology and sports medicine programs, respectively. Among respondents, musculoskeletal ultrasound training was present in 65% of radiology programs, 88% of sports medicine programs, 90% of rheumatology programs, and 100% of physical medicine and rehabilitation programs. Most programs utilized didactic lectures, followed by hands-on scanning. The majority of programs without current training intend to implement such training within 5 years, although radiology programs reported the lowest likelihood of this happening. Most program directors believed that musculoskeletal ultrasound education is important for their trainees, and is of greater importance than it was 10 years ago. Case volume was lowest for radiology trainees and highest for sports medicine trainees. CONCLUSION: Among respondents, the majority of diagnostic radiology programs offer musculoskeletal ultrasound training. However, this experience is even more widespread in other medical specialties, and hands-on training and experience tend to be greater in other specialties than in radiology.

Fluoroscopically guided retrocalcaneal bursa steroid injection: description of the technique and pilot study of short-term patient outcomes.

OBJECTIVE: To describe a lateral fluoroscopically guided retrocalcaneal bursa injection technique, report patient outcomes at 1-4 weeks after steroid/anesthetic retrocalcaneal bursal therapeutic injection, and correlate pre-injection diagnostic heel ultrasound variables with improvement in patient pain scores. MATERIALS AND METHODS: After IRB approval, fluoroscopically guided therapeutic retrocalcaneal bursa injections performed using a lateral approach were retrospectively reviewed. Pre-injection heel ultrasound results and pre- and post-injection patient VAS pain scores (scale 0-10) were recorded. The Wilcox matched-pair test compared pain scores, and Spearman's rho assessed for correlation between pain score changes and heel ultrasound results. RESULTS: Thirty-two injections were performed in 30 patients (25 females, 5 males; mean 56.5 ± 9.3 years, range 39-75 years; 21 left heel, 11 right heel) with technical success in 32 of 32 cases (100 %). Insertional Achilles tendon pathology and retrocalcaneal bursitis were present in 31 of 32 cases (97 %) and 16 of 32 cases (50 %), respectively. Median pre- and post-procedure pain scores were 8 (IQR 7, 10) and 1.75 (IQR 0, 6). A statistically significant decrease in pain score was observed following injection, with a median change of 4.75 (IQR 3, 8; p < 0.001). Clinically significant response (>50 % reduction in pain score) was present in 69 % (95 % CI, 0.52-0.86; p < 0.001). No significant correlation was identified between a decrease in pain score and a sonographically abnormal Achilles tendon or retrocalcaneal bursa. CONCLUSION: Fluoroscopically guided retrocalcaneal bursal steroid/anesthetic using a lateral approach is an effective technique. This technique yielded 100 % technical success and a clinically significant decrease in patient pain scores (p < 0.001).

MRI findings in pediatric patients with scurvy.

In modern times scurvy is a rarely encountered disease caused by ascorbic acid (vitamin C) deficiency. However, sporadic cases of scurvy persist, particularly within the pediatric population. Recent individual case reports highlight an increased incidence of scurvy among patients with autism or developmental delay, with isolated case reports detailing the magnetic resonance imaging (MRI) findings of scurvy in these pediatric populations. We present the MRI findings of scurvy in four patients with autism or developmental delay, and review the literature on MRI findings in pediatric patients with scurvy. Despite its rarity, the radiologist must consider scurvy in a pediatric patient with a restricted diet presenting with arthralgia or myalgia.

Pedicle screws adjacent to the great vessels or viscera: a study of 2132 pedicle screws in pediatric spine deformity.

STUDY DESIGN: A retrospective study. OBJECTIVE: To determine the incidence of pedicle screws close to vital structures and to identify patient or curve characteristics that increase the risk of screw misplacement. SUMMARY AND BACKGROUND: Most pedicle screw misplacements are asymptomatic, thus they are frequently undetected. This study identifies the rate of screw placement in proximity to vital structures using postoperative computed tomography scans. METHODS: A total of 2132 screws in 101 patients, who underwent posterior spinal fusion for spinal deformity, were reviewed. Screws adjacent to great vessels and viscera were identified and evaluated. Patients with screws at risk (group B) were compared with patients without screws at risk (group A). Patient and curve characteristics were analyzed to determine whether a correlation with screw misplacement exists. RESULTS: A total of 40 at risk screws (∼2%) were identified in 25 patients (∼25%). These 40 screws were in proximity to the aorta (31), left subclavian artery (1), esophagus (3), trachea (3), pleura (1), and diaphragm (1). Of the 31 screws close to the aorta, 10 screws in 6 patients were impinging or distorting the aortic wall. One hundred percent of misplaced screws were in the thoracic spine, 50% were misplaced laterally, 50% were 35 mm long, 57.5% were in pedicles with normal morphology, and 75% were in curves between 40 and 70 degrees. Median screw misplacement rate was 10% in group A and 13% in group B. Adjusted for age and preoperative Cobb angle, patients with a higher misplacement rate were more likely to have screws adjacent to vital organs [adjusted odds ratio: 1.06 (95% confidence interval, 1.01-1.13), P=0.033]. CONCLUSIONS: Although only a small number of screws were at risk, they occurred in a large percentage of patients (25%). A single at-risk screw causes a significant complication for the patient. Postoperative imaging beyond routine x-rays may be needed to detect at-risk screws in asymptomatic patients.

Utility of the coned-down lateral view of the lumbosacral spine.

OBJECTIVE: At certain institutions and radiology practices, a routine lumbar radiographic exam may include 3 views: AP, lateral, and coned-down lateral of the lumbosacral junction. The purpose of this study is to determine whether the third coned-down-lateral view adds significant diagnostic information regarding pathology at the L4-L5 and L5-S1 levels. MATERIALS AND METHODS: This retrospective study includes patients (n = 74) who had a 3-view radiographic exam of the lumbar spine, as well as a CT or MRI within six months. The AP and lateral views were reviewed by three radiologists, both with and without the use of the third, coned-lateral view. Subsequently, the CT and MRI performed within 6 months was reviewed, and the results compared. The primary outcome was detection of abnormal alignment and disc disease at the L4-L5 and L5-S1 levels. RESULTS: For the combined findings of alignment and disc disease at each L4-L5 and L5-S1, there was disagreement between the 2-view and 3-view exams on 18 (of 296) evaluations. Of these 18, the 2-view and the 3-view exam each made positive findings on 9. By the binomial test, there is no evidence that either the 2-view or the 3-view exam tends to make more findings than the other (p = 1). Compared to CT/MRI, the 2-view exam agrees on 74.7 % of evaluations and the 3-view exam agrees on 75.3 %. There is therefore no evidence that the 3-view exam is more accurate than the 2-view exam. CONCLUSION: Elimination of the coned-down lateral view could reduce radiation exposure and imaging-related costs while maintaining diagnostic quality.

Does a dedicated "Scoliosis Team" and surgical standardization improve outcomes in adolescent idiopathic scoliosis surgery and is it reproducible?

PURPOSE: The objective of this study was to determine if standardization improves adolescent idiopathic scoliosis (AIS) surgery outcomes and whether it is transferrable between institutions. METHODS: A retrospective review was conducted of AIS patients operated between 2009 and 2021 at two institutions (IA and IB). Each institution consisted of a non-standardized (NST) and standardized group (ST). In 2015, surgeons changed institutions (IA- > IB). Reproducibility was determined between institutions. Median and interquartile ranges (IQR), Kruskal-Wallis, and χ2 tests were used. RESULTS: 500 consecutive AIS patients were included. Age (p = 0.06), body mass index (p = 0.74), preoperative Cobb angle (p = 0.53), and levels fused (p = 0.94) were similar between institutions. IA-ST and IB-ST had lower blood loss (p < 0.001) and shorter surgical time (p < 0.001). IB-ST had significantly shorter hospital stay (p < 0.001) and transfusion rate (p = 0.007) than IB-NST. Standardized protocols in IB-ST reduced costs by 18.7%, significantly lowering hospital costs from $74,794.05 in IB-NST to $60,778.60 for IB-ST (p < 0.001). Annual analysis of surgical time revealed while implementation of standardized protocols decreased operative time within IA, when surgeons transitioned to IB, and upon standardization, IB operative time values decreased once again, and continued to decrease annually. Additions to standardized protocol in IB temporarily affected the operative time, before stabilizing. CONCLUSION: Surgeon-led standardized AIS approach and streamlined surgical steps improve outcomes and efficiency, is transferrable between institutions, and adjusts to additional protocol changes.

Maximizing time-resolved MRA for differentiation of hemangiomas, vascular malformations and vascularized tumors.

Contrast-enhanced magnetic resonance angiography (MRA) using time-resolved imaging is a relatively new and increasingly popular technique. We will describe the technique utilized at our institution, Time-Resolved Imaging of Contrast Kinetics (TRICKS; GE Healthcare, Milwaukee, WI), and the parameters that can be adjusted to optimize the exam. We will review key imaging features of hemangiomas and vascular malformations in various modalities, with a special emphasis on the TRICKS appearance.

Percutaneous Screw Stabilization of Non-Periacetabular Pelvic Lesions Caused by Metastatic Cancer and Multiple Myeloma.

BACKGROUND: The pelvis is one of the most common locations for metastatic bone disease. While many of the publications that describe surgical treatments focus on periacetabular lesions (Enneking zone II), there is a lack of investigation into lesions in the non-periacetabular areas (zones I, III, and IV). We recently described a minimally invasive percutaneous screw application for metastatic zone-II lesions with excellent results. In the present study, we aimed to extend this approach to the other pelvic areas. METHODS: Twenty-two consecutive patients with painful non-periacetabular pelvic metastatic cancer were included based on retrospective chart review. There were 16 women and 6 men with an average age of 60 years (range, 36 to 81 years). The most common primary cancers were multiple myeloma (7 cases) and breast (5 cases). The most common locations were the sacrum and the ilium. A pathologic fracture was identified in 15 patients. Most of the lesions were treated with multiple large-diameter screws, except for the isolated zone-III lesions. All of the procedures were completed in a standard operating room without the need for special instruments. Radiation therapy was given to 19 patients; the average dose was 15 Gy. The studied outcomes were pain and functionality as assessed by a visual analog scale (VAS) score and the Eastern Cooperative Oncology Group score (ECOG), respectively. RESULTS: There were no surgical complications and no need for blood transfusion. The average follow-up time was 7 months (range, 0.3 to 34.0 months). Two patients died within 4 weeks of surgery due to COVID-19 infection. There was significant improvement in the postoperative VAS pain score (p < 0.0001) and the ECOG score (p < 0.05) when compared with the preoperative scores. There was no implant failure or revision surgery. Local bone-healing was observed in 12 of 14 patients (86%) who survived for >3 months after surgery. CONCLUSIONS: Percutaneous screw application is safe and effective in the treatment of metastatic non-periacetabular pelvic lesions. Given the simplicity of the technique and the instrumentation and the tolerance for concomitant treatments, this approach is worthy of broader consideration. LEVEL OF EVIDENCE: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

A Newer Way of Determining LIV in AIS Patients: Rotation of the Touched Vertebrae.

STUDY DESIGN: A retrospective review. OBJECTIVE: The objective of this study was to determine whether fusing to touched vertebra (TV) on prone x-rays (XRs) with minimal rotation (Gd 0/1) allow for shorter fusion with optimal correction. SUMMARY OF BACKGROUND: Previous studies have shown risk of "adding on" when TV is not selected as lowest instrumented vertebra (LIV). Fusion proximal to TV leads to suboptimal results but fusing to TV on standing XRs can result in longer fusions. On lying down XRs, TV moves proximally, and its rotation decreases by a grade. METHODS: TV patients with minimal rotation were selected on prone (TVP) or standing XRs (TVS). Patients fused to rotated (Gd 2+) TV on standing or prone XRs were considered touched vertebra rotated (TVR). In the non-TV (NTV) group, LIV was fused proximal to TV. Disk wedging ≥5° determined risk of "adding-on." To compare patients fused to minimally rotated TV, to those that were not, patients in group A (TVP + TVS) were compared with group B (TVR + NTV).In part II: TVP, TVS, TVR, and NTV patients were compared. Subanalysis compared levels saved as the difference between predicted and real LIV in TVP and TVS patients. Another subanalysis was carried out for Lenke 1+2 and Lenke 3, 4, 5.In part III: XRs of nonoperative adolescents idiopathic scoliosis patients with Cobb <30 and Risser 4/5 were analyzed to determine "acceptable" end vertebra tilt and disc wedging and served as controls. RESULTS: There were a significantly greater number of patients in group B patients(TVR + NTV) with final disk wedging ≥5°, final LIV translation ≥1 and ≥2 cm ( P <0.001).Utilizing prone XRs in TVP saved average 1 level, and 1.2 levels in TVS patients. TVP patients also had similar LIV tilt, disk wedging and coronal balance( P >0.05) to controls. CONCLUSION: Choosing minimally rotated (Gd 0/1) TV on prone XR saves levels without sacrificing radiographic outcomes.

Ambulatory Neuromuscular Scoliosis Patients Have Superior Perioperative Results Than Nonambulatory Neuromuscular Scoliosis Patients and Can Approach Adolescent Idiopathic Scoliosis Outcomes After Posterior Spinal Fusion.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: This study aims to identify differences in perioperative outcomes between ambulatory patients with neuromuscular scoliosis (ANMS) and adolescent idiopathic scoliosis (AIS) following spinal fusion. SUMMARY OF BACKGROUND DATA: NMS patients have severe curves with more comorbidities and procedural complexity. These patients require extensive fusion levels, increased blood loss, and suffer increased periop complications. However, NMS patients have a variable severity spectrum, including ambulation status. METHODS: Chart and radiographic review of NMS and AIS patients undergoing PSF from 2005 to 2018. NNMS included NMS patients who were completely dependent (GMFCS IV-V). ANMS consisted of community ambulators without significant reliance on wheeled assistive devices (GMFCS I-III). Subanalysis matched by age, sex, levels fused and preoperative Cobb angle was conducted as well. Wilcoxon Rank-Sum, Kruskal-Wallis, χ2, and Fisher exact tests were performed. RESULTS: There were 120 patients in the NNMS group, 54 in ANMS and 158 in the AIS group. EBL was significantly lower for ANMS and AIS patients (P < 0.001). Complications within 30 days were similar between ANMS and AIS (P = 1.0), but significantly higher for NNMS (P < 0.001). Two (1.3%) AIS patients, (1.7%) nonambulatory NMS patients, and one (1.9%) ANMS patient required revision surgery (P = 1.0). However, all NMS patients had increased fusion levels, fixation points, and surgery time (P < 0.05). NNMS had significantly longer ICU (P < 0.001), hospital stay (P < 0.001), intraoperative transfusions (P < 0.001), and fewer patients extubated in the OR (P < 0.001) than ANMS and AIS patients. In the subanalysis, ANMS had similar radiographic measurements, EBL, transfusion, surgery time, extubation rate, and complication rate (P > 0.05) to AIS. CONCLUSION: Our data show radiographic outcomes, infections, revisions, and overall complications for ANMS were similar to the AIS population. This suggests that NMS patients who ambulate primarily without assistance can expect surgical outcomes comparable to AIS patients with further room for improvement in length of ICU and hospital stay.Level of Evidence: 4.

Aggressively recurrent infantile myofibroma of the axilla and shoulder girdle.

Infantile myofibroma is the most common fibrous tumor of infancy, typically affecting neonates and children under 2 years of age. Though the multicentric variant portends a grave prognosis, solitary lesions have an excellent prognosis and frequently undergo spontaneous regression. Surgical excision of solitary lesions is usually curative. In this report, we describe a pediatric patient with an unusually aggressive solitary myofibroma of the axilla who ultimately required a forequarter amputation as a lifesaving measure following multiple tumor recurrences and progressive tumor growth. The clinical course, radiographic findings, histology, and management rationale are presented.

A dual-team approach benefits standard-volume surgeons, but has minimal impact on outcomes for a high-volume surgeon in AIS patients.

STUDY DESIGN: Retrospective chart review of prospectively collected data. OBJECTIVE: This study seeks to evaluate the effect of number of surgeons, surgeon experience, and surgeon volume on AIS surgery. Recent literature suggests that utilizing two surgeons for spine deformity correction surgery can improve perioperative outcomes. However, the surgeon's experience and surgical volume are likely as important. METHODS: AIS patients undergoing PSF from 2009 to 2019 were included. Patient demographics, X-ray and perioperative outcomes were collected and collated based on primary surgeon. Analysis was performed for single versus dual surgeons, surgeon experience (≤ 10 years in practice), and surgical volume (less/greater than 50 cases/year). Median (IQR) values, Wilcoxon Rank Sums test, Kruskal-Wallis test, and Fisher's exact test were utilized. RESULTS: 519 AIS cases, performed by 4 surgeons were included. Two surgeons were highly experienced, 1 of whom was also high volume. Five cohorts were studied: a single senior high volume (S1) (n = 302), dual-junior surgeons (DJ) (n = 73), dual senior-junior (SJ) (n = 36), dual-senior (DS) (n = 21) and a single senior, standard-volume surgeon alone (S2) (n = 87). Radiographic parameters were similar between the groups (p > 0.05). Preoperative Cobb was significantly higher for DS compared to S1 (p = 0.034) Pre- and post-op kyphosis were similar (p > 0.05). Cobb correction was similar (p > 0.05). Levels fused, fixation points, anesthesia and surgical times were similar (p > 0.05). When the standard-volume surgeon operated with a second surgeon, radiographic parameters were similar (p > 0.05), but anesthesia time, surgical time, and hospital length of stay were significantly shorter (p < 0.05). Additionally, DJ had significantly shorter anesthesia and operative times (p < 0.001) and length of stay (p < 0.001) compared to S2. CONCLUSION: Standard-volume surgeons have better outcomes with a dual surgeon approach. Junior surgeons benefit operating with an experienced surgeon. A high-volume surgeon, however, does not benefit from a dual surgeon approach. LEVEL OF EVIDENCE: Level II.

A Study of Critical Events That Lead to Spinal Cord Injury and the Importance of Rapid Reversal of Surgical Steps in Improving Neurological Outcomes: A Porcine Model.

STUDY DESIGN: Porcine model. OBJECTIVE: To quantify critical vascular and mechanical events that occur before and during an evolving spinal cord injury. SUMMARY OF BACKGROUND DATA: Spinal cord injuries are one of the most devastating complications in spine surgery. Intraoperative neuromonitoring changes can occur as a secondary event of spinal cord compression and decrease in spinal cord blood flow (SCBF). Laser Doppler flowmetry has been well validated for measuring blood flow. METHODS: Seventeen pigs were studied, 14 of which completed the experiment. Multilevel, midthoracic laminectomies were performed. Laser Doppler flowmetry electrodes were placed on the dura to measure SCBF. Spinal cord injury was induced by incremental balloon inflation in the epidural space. The animals were separated into two groups. After motor-evoked potential (MEP) loss, group A underwent medical interventions and then balloon decompression approximately 20 minutes later. Group B underwent immediate balloon decompression followed by medical interventions. After interventions, wake-up test was performed and computed tomography scan measured thoracic spinal canal volume. RESULTS: Median SCBF changes were seen 15.8 (5.4-25.1) minutes before MEP loss. However, the 20% threshold interval was often reached before. At the 20% threshold, median pressure was 7 psi, balloon volume was 0.5 cm, and 50% of the spinal canal was compromised. In group A, no pigs moved and all had pathology indicating ischemia. In group B, 9 of 10 were found to be moving their hind legs with 7 indicating ischemia. CONCLUSION: Compression spinal cord injury is the end of a cascade involving increasing intracanal pressure, decreasing canal volume, and hypoperfusion. Rapid relief of compression leads to MEP return. SCBF monitoring can detect ischemia preinjury, giving surgeons an opportunity for early intervention. LEVEL OF EVIDENCE: 4.

The Screw-Aorta Dilemma: Changing Patient Position in Computed Tomography Scan Is Critical in Documenting Aortic Mobility.

STUDY DESIGN: Retrospective chart review. OBJECTIVE: To determine if obtaining a prone computed tomography (CT)-scan can better delineate a questionable screw-aorta relationship. SUMMARY OF BACKGROUND DATA: Pedicle screw misplacement rate is reported between 6% and 15%. Studies looking at misplacements on a per patient basis show up to 14% of patients have screws at risk (impinging vital structures). A screw abutting the aorta is a management challenge and often requires vascular surgery intervention. However, CT scans routinely done in supine position may overestimate screw-aorta relationship. Change in patient position may allow the aorta to roll away and, in most cases, reveal an uncompromised aorta. This will allow safe removal of pedicle screws without any vascular intervention. METHODS: One hundred eleven spinal deformity patients who underwent Posterior spinal fusion from 2004 to 2009 were evaluated. Patients with concerning screw-aorta relationship underwent additional prone CT scan. Mobility of the aorta was determined and distance was compared using prone and supine CT scans. RESULTS: Two thousand two hundred ninety five screws were reviewed, 36 screws in 18 patients were in proximity to the aorta. Fourteen screws (nine patients) appeared to be impinging the aorta. On prone CT, 13 out of the 14 instances the aorta moved away from the screw. The average distance at the screw level was 13.6 ±â€Š4.8 mm in supine position and 8.9 ±â€Š5.4 mm in prone position (P = 0.001). In one instance the relationship was unchanged on prone CT. No screw was noted to violate the lumen or distort the aorta. CONCLUSION: Supine CT scan alone is not entirely accurate in determining screw-aorta relationship. Prone-CT scan provides additional information for better delineation. This additional diagnostic step can change the treatment option by limiting the need for vascular intervention. When in doubt, the additional use of an arteriogram can allow for improved visualization. LEVEL OF EVIDENCE: 3.

Pain in the butt: spectrum of gluteal region abnormalities in children.

OBJECTIVE: The purpose of this study was to illustrate the spectrum of solitary gluteal lesions in children. The distinctive anatomic and radiologic features are discussed. CONCLUSION: Pathologic entities in the gluteal region reflect the diversity of tissue types present. Ultrasound is valuable for imaging of infants and young children and for evaluating superficial lesions. Cross-sectional imaging is most useful for defining the extent of disease and may show pathognomonic features, enabling a precise diagnosis.

Cryptococcal pyarthrosis and sarcoidosis.

Cryptococcus neoformans is an infrequent cause of septic arthritis. Cryptococcal infections have been linked to sarcoidosis because of both inherent immunologic consequences of the disease and its typical immune modulating treatments. Cryptococcal infections should be suspected in patients with underlying immune deficiencies, and a high degree of vigilance should be exercised to avoid misdiagnosis, dissemination of infection, and meningitis.

Design and Validation of a Peer-Teacher-Based Musculoskeletal Ultrasound Curriculum.

RATIONALE AND OBJECTIVES: To design and validate a peer-teacher based musculoskeletal ultrasound curriculum for radiology residents. MATERIALS AND METHODS: A musculoskeletal ultrasound curriculum with hands-on scanning workshops was designed for radiology residents. Prior to the workshops, several residents received 3 hours of hands-on training in ultrasound scanning technique which was overseen by an attending musculoskeletal radiologist; these "peer teachers" then led small-group hands-on scanning during the workshops. Participants performed diagnostic ultrasound examinations at the conclusion of the workshops to assess skill acquisition and 2 months following the workshops to quantify skill retention. Participants also completed surveys to determine confidence in performing musculoskeletal ultrasound examinations. Median scores and interquartile range (25-75%) were calculated, and t test was used to compare results. RESULTS: Thirty seven residents from all years of training and six senior resident or fellow peer teachers participated in four workshops. Diagnostic ultrasound images were obtained in 100% at the conclusion of the workshop and in 79% 2 months later. Prior to the workshops, residents reported low level of musculoskeletal ultrasound knowledge (median 2, interquartile ranges 1-2), and low confidence in performing (1, 1-2) and interpreting (1, 1-2) musculoskeletal ultrasound examinations. There was a significant increase in knowledge (3, 3-4) and confidence performing (3, 3-4) and interpreting (3, 3-4) studies following the workshops (p < 0.001 for all comparisons). CONCLUSION: Hands-on musculoskeletal ultrasound workshops, utilizing a peer teacher led small group format is an effective method of teaching scanning skills to residents. There was excellent skill acquisition, good skill retention, and significant increase in confidence performing and interpreting these studies following completion of the curriculum.