Ultrasound evaluations and guided procedures of the painful joint arthroplasty.

The purpose of this article is to describe the use of ultrasound for the diagnosis and treatment of painful joint arthroplasty. Ultrasound plays a crucial role in the diagnosis of the painful joint arthroplasty, especially given its unique dynamic capabilities, convenience, and high resolution. Ultrasound guidance is also instrumental for procedures in both diagnosing and in select cases, treating the painful joint arthroplasty. Topics to be discussed in this article include trends in arthroplasty placement, benefits of the use of ultrasound overall, and ultrasound evaluation of periprosthetic joint infections. We will also review the sonographic findings with dissociated/displaced components and adverse reaction to metallic debris including metallosis, trunnionosis, and metal-on-metal pseudotumors. Additionally, we will discuss ultrasound evaluation of tendon pathologies with arthroplasties, including dynamic maneuvers to evaluate for tendon impingement/snapping. Finally, we will cover ultrasound-guided joint arthroplasty injection indications and precautions. KEY POINTS: • Ultrasound is preferred over MRI in patients with joint arthroplasty and plays a crucial role in diagnosis, especially given its unique dynamic capabilities, convenience and high resolution. • It is especially beneficial for US-guided aspiration in periprosthetic joint infections; effectively used to evaluate periprosthetic fluid collections, facilitating differentiation between abscesses and aseptic collections, and tracking sinus tracts. • Recently, the diagnosis of periprosthetic joint infections has shifted focus to biomarkers in the periprosthetic fluid, specifically α-defensin, which has a high sensitivity and specificity for diagnosing infection. • Cutibacterium acnes is a major pathogen responsible for shoulder arthroplasty infections, often presenting with normal laboratory values and since slow growing, must be kept for a minimum of 14 days.

Elbow Torque Is Reduced in Asymptomatic College Pitchers With Elbow Laxity: A Dynamic Ultrasound Study.

PURPOSE: To determine the relation between medial elbow torque, as measured by wearable sensor technology, and adaptations of the medial elbow structures on dynamic ultrasound imaging in asymptomatic collegiate pitchers. METHODS: Thirty-four pitchers from National Collegiate Athletic Association Division II universities were eligible for preseason testing. The exclusion criteria included age younger than 18 years, history of surgery, non-pitcher, or current restrictions. Pitchers were fitted with a wearable sensor sleeve that recorded elbow torque, arm slot, arm speed, and arm rotation. Pitchers threw 5 fastballs in a standardized manner off the mound at game-speed effort. They also underwent dynamic ultrasound imaging of the elbow by a musculoskeletal sonographer, with standardized valgus loading. Images were deidentified, and measurements of the ulnar collateral ligament (UCL) and ulnohumeral joint space (UHJS), to assess elbow laxity, were performed by a musculoskeletal radiologist. RESULTS: The final analysis included 28 pitchers with an average age of 20.1 years (standard deviation, 1.3 years; range, 18-23 years) and playing experience of 15.3 years (standard deviation, 1.8 years; range, 11-19 years). The dominant UCL thickness (P < .001), loaded UHJS (P = .039), and delta UHJS (P < .001) were significantly greater than the nondominant measurements. An inverse correlation was found between loaded UHJS and medial elbow torque (r = -0.4, P < .001). Additionally, every 1-mm increase in UHJS significantly reduced medial elbow torque by 2.27 Nm (P = .032) and arm slot by 8.8° (P = .019) and increased arm rotation by 5.3° (P = .043). Pitchers with a loaded UHJS of 4.4 mm or greater and delta UHJS of 1.25 mm or greater had significantly reduced medial elbow torque (P < .001). Pitchers with a UCL thickness of 1.65 mm or greater had significantly increased medial elbow torque (47.4 Nm vs 44.8 Nm, P = .006). CONCLUSIONS: Pitchers with increased dynamic elbow laxity were found to experience reduced medial elbow torque while pitching. Additionally, pitchers with greater UCL thickness on ultrasound were found to experience increased medial elbow torque while pitching. This study's findings suggest a relation between anatomic adaptations found on ultrasound of the pitching elbow and medial elbow torque. LEVEL OF EVIDENCE: Level II, prospective cohort study.

Impingement-Free Hip Flexion in Asymptomatic Young Adult Women.

BACKGROUND: Ultrasound-assisted measurement of hip flexion has demonstrated that hip flexion has been historically overestimated in men. To our knowledge, assessment of hip flexion in women using similar methods has not been reported. Establishing normative values for hip flexion is vital to aid diagnosis, management, and future research. Therefore, we asked 2 questions: (1) At what range of midsagittal hip flexion do soft-tissue impingement and femoroacetabular abutment occur in asymptomatic young adult women? (2) Do radiographic findings on a supine anteroposterior pelvic radiograph correlate with ultrasound-assisted measurements of hip flexion? METHODS: Fifty-five asymptomatic adult women volunteers (107 hips) underwent ultrasound-assisted assessment of hip flexion. Hip flexion was recorded at the initiation of labral contact and at bone-on-bone contact. Recorded motion was correlated with common radiographic measurements of hip morphology as observed on a supine anteroposterior pelvic radiograph. RESULTS: The mean age of the subjects was 26 ± 3 years (range, 21 to 35 years), and the mean body mass index was 23 ± 3 kg/m (range, 17 to 31.6 kg/m). Mean impingement-free and maximum midsagittal passive flexion were 72° ± 8° (95% confidence interval [CI], 70° to 74°) and 101° ± 11° (95% CI, 99° to 103°), respectively. There were no significant correlations between radiographic measurements of hip morphology and ultrasound-measured hip range of motion. CONCLUSIONS: Observed hip flexion in the asymptomatic hips of young women is substantially less than has been historically reported. Morphologic features that are measurable on anteroposterior pelvic radiographs do not correlate with ultrasound-measured hip flexion. Diagnosis of hip disorders and treatments that are designed to alter hip range of motion should be based on normative data. Future studies regarding surgical restoration and/or preservation of hip flexion should be based on an understanding of normal hip range of motion. CLINICAL RELEVANCE: Ultrasound-assisted hip flexion measurement established normative values to guide surgical restoration and/or preservation of hip flexion.

Digital Tomosynthesis and Fractal Analysis Predict Prevalent Vertebral Fractures in Patients With Multiple Myeloma: A Preliminary In Vivo Study.

OBJECTIVE. The objective of this study was to investigate the association of fractal-derived bone microstructural parameters with vertebral fracture status using in vivo digital tomosynthesis images of the spine. MATERIALS AND METHODS. Digital tomosynthesis images of the thoracic and lumbar spine from T1 to L5 were acquired from 36 patients with newly diagnosed multiple myeloma or monoclonal gammopathy of uncertain significance (age range, 39-85 years old). Scans were performed with patients in the supine position with reconstructed planes formed in the coronal direction. Bone mineral density (BMD) was recorded for 10 patients who had recently undergone dual x-ray absorptiometry. Vertebral fracture and lytic lesion status was determined by a radiologist from digital radiographs. Radiologist interpretation was reviewed to identify levels with a minimum number of fractures or lesions. For fractal analysis, the largest possible cuboid volume of interest within the cancellous bone was cropped from T7 and T11 images. Mean and SD of fractal variables between slices of fractal dimension (FD, a measure of self-similarity in the texture), mean lacunarity (λ, a measure of heterogeneity) and the slope of lacunarity versus box size relationship (Sλ, a measure of sensitivity of heterogeneity to size scale) were calculated using a box-counting method. A generalized estimating equation (GEE) platform was used to examine fractal variables as predictors of fracture status. RESULTS. Fracture status was not significantly associated with sex, race, age, stage of myeloma, presence of lesion in the spine, or BMD. In light of these results, no correction was made for these variables in further analyses of fractal variables. No interaction was found between vertebral level and any of the fractal variables (p = 0.12-0.77). Therefore, vertebral level was not considered further as an independent variable. Logistic regression analysis within GEE indicated that probability of fracture decreased with increasing mean FD (p = 0.02). In contrast, probability of fracture increased with increasing mean λ (p = 0.03). Although not to a statistically significant degree, probability of fracture increased with increasing mean Sλ (p = 0.08), SD of FD (p = 0.07), SD of λ (p = 0.07), and SD of Sλ (p = 0.06). CONCLUSION. We found FD and lacunarity calculated within the cancellous centrum of T7 and T11 vertebrae to be significantly associated with the presence of a vertebral fracture in this cohort. The decreased probability of fracture with increasing fractal dimension and increased probability of fracture with increasing lacunarity are consistent with the idea that cancellous bone with a better organized trabecular architecture is mechanically more competent. To our knowledge, this is the first in vivo evidence that fractal analysis of vertebral bone from tomosynthesis images may be useful in assessing vertebral fracture risk in patients with multiple myeloma.

Inguinal Hernia in Athletes: Role of Dynamic Ultrasound.

BACKGROUND: Inguinal hernia is a commonly encountered cause of pain in athletes. Because of the anatomic complexity, lack of standard imaging, and the dynamic condition, there is no unified opinion explaining its underlying pathology. HYPOTHESIS: Athletes with persistent groin pain would have a high prevalence of inguinal hernia with dynamic ultrasound, and herniorrhaphy would successfully return athletes to activity. STUDY DESIGN: Case-control study. LEVEL OF EVIDENCE: Level 3. METHODS: Forty-seven amateur and professional athletes with sports-related groin pain who underwent ultrasound were selected based on history and examination. Patients with prior groin surgery or hip pathology were excluded. Clinical and surgical documentation were correlated with imaging. The study group was compared with 41 age-matched asymptomatic athletes. RESULTS: Ultrasound was positive for hernia with movement of bowel, bladder, or omental tissue anterior to the inferior epigastric vessels during Valsalva maneuver. The 47-patient symptomatic study group included 41 patients with direct inguinal hernias, 1 with indirect inguinal hernia, and 5 with negative ultrasound. Of 42 patients with hernia, 39 significantly improved with herniorrhaphy, 2 failed to improve after surgery and were diagnosed with adductor longus tears, and 1 improved with physical therapy. Five patients with negative ultrasound underwent magnetic resonance imaging and were diagnosed with hip labral tear or osteitis pubis. The 41-patient asymptomatic control group included 3 patients with direct inguinal hernias, 2 with indirect inguinal hernias, and 3 with femoral hernias. CONCLUSION: Inguinal hernias are a major component of groin pain in athletes. Prevalence of direct inguinal hernia in symptomatic athletes was greater than that for controls ( P < 0.001). Surgery was successful in returning these athletes to sport: 39 of 42 (93%) athletes with groin pain and inguinal hernia became asymptomatic. CLINICAL RELEVANCE: Persistent groin pain in the athlete may relate to inguinal hernia, which can be diagnosed with dynamic ultrasound imaging. Herniorrhaphy is successful at returning athletes to sports activity.

Ultrasound findings in asymptomatic patients with modular metal on metal total hip arthroplasty.

OBJECTIVE: The use of metal-on-metal and modular total hip arthroplasty is associated with potentially serious local and systemic complications. The primary aim of this study was to identify the prevalence of a pseudotumor in asymptomatic patients with a particular metal-on-metal hip prosthesis after a minimum follow-up of 5 years using ultrasound evaluation. A secondary purpose was to identify associations between the presence of pseudotumor and serum metal ion levels following implantation. METHODS: We prospectively evaluated data collected from 36 asymptomatic patients who underwent implantation of a Profemur Z metal-on-metal total hip arthroplasty from January 2004 to January 2010. Serum metal ion levels were collected in 2012 and 2015. Hip ultrasounds were performed in 2015. RESULTS: Pseudotumors were found in 7/36 patients (19.4%). The average pseudotumor size measured 38.2 cm3 (range 7.35 cm3-130.81 cm3). Elevated metal ion levels were found in all patients at all time points. No statistical correlation was found between the presence of pseudotumor and patient age, age of the implant, component design, and any of the serum metal ion levels or ratios. CONCLUSIONS: One in every five asymptomatic patients with metal-on-metal implants was found to have a periarticular pseudotumor. There was no dose-dependent relationship found between elevated serum metal ion levels and the development of a pseudotumor. Our findings suggest that in patients with known elevated metal ion levels, continued monitoring of ion levels may not be a reliable predictor of pseudotumor formation, and ultrasound surveillance can and should be routinely used to document the presence and progression of pseudotumor.

Effects of asymptomatic rotator cuff pathology on in vivo shoulder motion and clinical outcomes.

BACKGROUND: The incidence of asymptomatic rotator cuff tears has been reported to range from 15% to 39%, but the influence of asymptomatic rotator cuff pathology on shoulder function is not well understood. This study assessed the effects of asymptomatic rotator cuff pathology on shoulder kinematics, strength, and patient-reported outcomes. METHODS: A clinical ultrasound examination was performed in 46 asymptomatic volunteers (age: 60.3 ± 7.5 years) with normal shoulder function to document the condition of their rotator cuff. The ultrasound imaging identified the participants as healthy (n = 14) or pathologic (n = 32). Shoulder motion was measured with a biplane x-ray imaging system, strength was assessed with a Biodex (Biodex Medical Systems, Inc., Shirley, NY, USA), and patient-reported outcomes were assessed using the Western Ontario Rotator Cuff Index and visual analog scale pain scores. RESULTS: Compared with healthy volunteers, those with rotator cuff pathology had significantly less abduction (P = .050) and elevation (P = .041) strength, their humerus was positioned more inferiorly on the glenoid (P = .018), and the glenohumeral contact path length was longer (P = .007). No significant differences were detected in the Western Ontario Rotator Cuff Index, visual analog scale, range of motion, or acromiohumeral distance. CONCLUSIONS: The differences observed between the healthy volunteers and those with asymptomatic rotator cuff pathology lend insight into the changes in joint mechanics, shoulder strength, and conventional clinical outcomes associated with the early stages of rotator cuff pathology. Furthermore, these findings suggest a plausible mechanical progression of kinematic and strength changes associated with the development of rotator cuff pathology.

The advantages of tomosynthesis for evaluating bisphosphonate-related atypical femur fractures compared to radiography.

OBJECTIVE: To investigate the advantages of using tomosynthesis (TS) compared to radiographs in the detection, characterization, and follow-up of bisphosphonate-related atypical femur fractures (BP-AFF). SUBJECTS AND METHODS: Eight patients were identified retrospectively who underwent TS for radiographic findings suspicious for BP-AFF. Two radiologists independently interpreted 15 radiographs and 16 TS examinations, indicating the presence or absence of the following: (1) cortical "beaking" on radiographs, (2) radiolucent fracture line on radiographs, and (3) fracture lucency on TS corresponding to the site of radiographic abnormality. Radiation dose data were calculated for radiographs and TS using Monte Carlo analysis. RESULTS: There was agreement on 100 % of radiographs regarding the presence or absence of a cortical beak. Regarding the presence or absence of a fracture lucency, there was agreement on 100 % of TS examinations (Kappa = 1.0) and 73 % of radiographs (Kappa = 0.40 ± 0.24). For the 46 % of radiographs in which one or both radiologists did not visualize a fracture line, there was 100 % agreement for the presence of a fracture line on the corresponding TS. The interobserver agreement for fracture line detection was significantly higher for TS than for radiographs (p = 0.012). The effective radiation dose using TS was approximately 96 % lower compared to radiography. CONCLUSION: TS outperformed radiographs in the detection and characterization of BP-AFF. TS may also have advantages over radiography for BP-AFF follow-up through its unique ability to visualize fracture healing with lower effective radiation doses to the patient.

Ulnar Collateral Ligament and Elbow Adaptations in High School Baseball Pitchers.

BACKGROUND: Baseball pitchers have adaptive changes in the soft tissues of the throwing elbow. HYPOTHESIS: High school baseball pitchers would show adaptive changes in the ulnar collateral ligament (UCL), such as calcifications and hypoechoic foci, thickening, and increased ulnohumeral joint laxity, on dynamic ultrasound (DUS). STUDY DESIGN: Cross-sectional study. LEVEL OF EVIDENCE: Level 3. METHODS: Twenty-two asymptomatic high school pitchers, designated as their primary position by their coach, underwent DUS and physical examination of the throwing and nonthrowing elbows prior to the start of the season. UCL substance consistency and thickness, ulnohumeral joint space widening, and soft tissue elbow structures were evaluated. RESULTS: The mean age of the cohort was 16.9 years. Calcifications of the UCL were similar, being present in 7 of 22 (32%) throwing elbows versus 8 of 22 (36%) nonthrowing elbows (P = 0.11). UCL hypoechoic foci also were similar between elbows: 2 of 22 (9%) throwing elbows versus 0 of 22 nonthrowing elbows (P = 0.11). UCL thickness was also found to be similar in both elbows (throwing arm, 6.54 mm vs nonthrowing, 6.71 mm; P = 0.48). Ulnohumeral joint laxity unloaded (throwing arm, 3.13 mm vs nonthrowing, 3.17 mm; P = 0.835) and loaded (throwing arm, 3.87 mm vs nonthrowing arm, 4.11 mm; P = 0.30) was similar between elbows. Throwing elbows showed posteromedial olecranon spurring in 36%, effusions in 27%, and synovitis in 9%. CONCLUSION: High school pitchers show limited adaptive changes in the elbow, including UCL calcifications, hypoechoic foci, posteromedial olecranon spurring, and effusions. However, these changes are similar to those seen in the nonthrowing elbow, and these younger athletes lack findings seen in professional and collegiate pitchers such as UCL thickening and increased ulnohumeral joint space laxity. CLINICAL RELEVANCE: Preseason ultrasound examination of the high school pitching elbow lacks the adaptive changes to the elbow as seen in professional pitchers. These changes likely occur later in a pitcher's career.

Pre- and Postseason Dynamic Ultrasound Evaluation of the Pitching Elbow.

PURPOSE: To use ultrasound imaging to document changes over time (i.e., preseason v postseason) in the pitching elbow of high school baseball pitchers. METHODS: Twenty-two high school pitchers were prospectively followed. Pitchers were evaluated after a 2-month period of relative arm rest via preseason physical exams, dynamic ultrasound imaging of their throwing elbow, and the Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) assessment. Players were reevaluated within 1 week of their last game. Dynamic ultrasound images were then randomized, blinded to testing time point, and evaluated by 2 fellowship-trained musculoskeletal radiologists. RESULTS: Average pitcher age was 16.9 years. Average pitches thrown was 456.5, maximum velocity 77.7 mph, games pitched 7.3, and days off between starts 6.6. From preseason to postseason, there were significant increases in ulnar collateral ligament (UCL) thickness (P = .02), ulnar nerve cross-sectional area (P = .001), UCL substance heterogeneity (P = .001), and QuickDASH scores (P = .03). In addition, there was a nonsignificant increase in loaded ulnohumeral joint space (P = .10). No pitchers had loose bodies on preseason exam, while 3 demonstrated loose bodies postseason. The increase in UCL thickness was significantly associated with the number of bullpen sessions per week (P = .01). The increase in ulnar nerve cross-sectional area was significantly associated with the number of pitches (P = .04), innings pitched (P = .01), and games pitched (P = .04). CONCLUSIONS: The stresses placed on the elbow during only one season of pitching create adaptive changes to multiple structures about the elbow including UCL heterogeneity and thickening, increased ulnohumeral joint space laxity, and enlarged ulnar nerve cross-sectional area. LEVEL OF EVIDENCE: Level II prospective observational study.

Value of ultrasound before joint aspiration.

OBJECTIVE: The purpose of this article is to illustrate and discuss the value of ultra-sound screening before joint aspiration. CONCLUSION: Before joint aspiration, ultrasound assessment of the overlying and surrounding soft tissues requires little time and is relatively inexpensive. Bursal fluid collections, soft-tissue abscesses, and other fluid collections that would be undetected with fluoroscopy or blind aspiration can thus be identified. Ultrasound screening before joint aspiration can aid diagnosis and decrease the risk of iatrogenic complications.

Angiosarcoma of the humerus presenting with fluid-fluid levels on MRI: a unique imaging presentation.

Fluid-fluid levels are a known feature of a number of osseous lesions, but have never before been described in primary osseous angiosarcoma, which is itself a rare malignancy. We report a case of humeral angiosarcoma presenting with fluid-fluid levels. Recognizing this entity as a possible etiology for fluid-fluid levels could help radiologists to avoid potential confusion in the differential diagnosis on imaging.

2011 Mid-America Orthopaedic Association Dallas B. Phemister Physician in Training Award: Can musculoskeletal tumors be diagnosed with ultrasound fusion-guided biopsy?

BACKGROUND: Percutaneous biopsy for musculoskeletal tumors commonly relies on imaging adjuncts including ultrasound (US), CT, or MRI. These modalities however have disadvantages (US) or are cumbersome, not universally available, and costly (CT and MRI). US fusion is a novel technique that fuses previously obtained CT or MRI data with real-time US, which allows biopsies to be performed in an US suite. It has proven useful in various body systems but musculoskeletal applications remain scarce. Our goal is to evaluate the fusion technology and determine its ability to diagnose musculoskeletal tumors. QUESTIONS/PURPOSES: We determined whether biopsies performed via US fusion compared with CT guidance provide equivalent diagnostic yield and accuracy and allow quicker biopsy scheduling and procedure times. METHODS: Forty-seven patients were assigned to undergo either US fusion (with MR, n = 16 or CT, n = 15) or CT-guided biopsies (n = 16). We evaluated adequacy of the histologic specimen (diagnostic yield) and correlation with surgical pathology (diagnostic accuracy). We determined scheduling times and lengths of the biopsy. RESULTS: US fusion and CT-guided biopsy groups had comparable diagnostic yields (CT = 94%; US/MRI = 94%; US/CT = 93%) and accuracy (CT = 83%; US/MRI = 90%; US/CT = 100%). US fusion biopsies were faster to schedule and perform. All procedures were safe with minimal complications. CONCLUSIONS: US fusion provides a high diagnostic yield and accuracy comparable to CT-guided biopsy while performed in the convenience of an US suite. This may have resulted in the observed faster scheduling and biopsy times. LEVEL OF EVIDENCE: Level II, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

In vivo shoulder function after surgical repair of a torn rotator cuff: glenohumeral joint mechanics, shoulder strength, clinical outcomes, and their interaction.

BACKGROUND: Surgical repair of a torn rotator cuff is based on the belief that repairing the tear is necessary to restore normal glenohumeral joint (GHJ) mechanics and achieve a satisfactory clinical outcome. HYPOTHESIS: Dynamic joint function is not completely restored by rotator cuff repair, thus compromising shoulder function and potentially leading to long-term disability. STUDY DESIGN: Controlled laboratory study and Case series; Level of evidence, 4. METHODS: Twenty-one rotator cuff patients and 35 control participants enrolled in the study. Biplane radiographic images were acquired bilaterally from each patient during coronal-plane abduction. Rotator cuff patients were tested at 3, 12, and 24 months after repair of a supraspinatus tendon tear. Control participants were tested once. Glenohumeral joint kinematics and joint contact patterns were accurately determined from the biplane radiographic images. Isometric shoulder strength and patient-reported outcomes were measured at each time point. Ultrasound imaging assessed rotator cuff integrity at 24 months after surgery. RESULTS: Twenty of 21 rotator cuff repairs appeared intact at 24 months after surgery. The humerus of the patients' repaired shoulder was positioned more superiorly on the glenoid than both the patients' contralateral shoulder and the dominant shoulder of control participants. Patient-reported outcomes improved significantly over time. Shoulder strength also increased over time, although strength deficits persisted at 24 months for most patients. Changes over time in GHJ mechanics were not detected for either the rotator cuff patients' repaired or contralateral shoulders. Clinical outcome was associated with shoulder strength but not GHJ mechanics. CONCLUSION: Surgical repair of an isolated supraspinatus tear may be sufficient to keep the torn rotator cuff intact and achieve satisfactory patient-reported outcomes, but GHJ mechanics and shoulder strength are not fully restored with current repair techniques. CLINICAL RELEVANCE: The study suggests that current surgical repair techniques may be effective for reducing pain but have not yet been optimized for restoring long-term shoulder function.

Atypical rapid progression of osteoarticular amyloidosis involving the hip in a patient on hemodialysis using polyacrylonitrile membranes.

Amyloidosis related to dialysis is a well-known complication affecting many organ systems, in particular the musculoskeletal system. In 1985 Shirahama et al. (Biochem Biophys Res Commun 53:705-709, 1985) identified beta-2 microglobulin (MG) as the offending constituent by using protein purification techniques. Amyloidosis has been increasing in prevalence because of longer life spans and increased chronic medical conditions such as end-stage renal disease. When dialysis-related amyloidosis involves the musculoskeletal system, it affects the shoulder girdle, the so called shoulder pad sign, the wrist, hip, knee, and spine (Resnick, Diagnosis of bone and joint disorders, 4th edn., pp. 2054-2058 and 2176-2183, 2002). Other osteoarticular manifestations of amyloidosis include osteoporosis, lytic lesions, and pathologic fractures. It has been well documented that the prevalence of amyloid is dependent on duration of dialysis-over 90% in patients on dialysis for over 7 years (Jadoul, Nephrol Dial Transplant 13:61-64, 1998). However, a recent changeover to high-flux membranes used in hemofiltration has been reported to delay its onset (Campistol et al., Contrib Nephrol 125:76-85, 1999). We report on the radiographic, nuclear medicine, and computed tomography (CT) findings of osteoarticular amyloidosis involving the hip, and sequence its atypical rapid onset. The imaging, histopathological findings, and differential diagnosis are discussed.

Battling fire and ice: remote guidance ultrasound to diagnose injury on the International Space Station and the ice rink.

BACKGROUND: National Aeronautical and Space and Administration (NASA) researchers have optimized training methods that allow minimally trained, non-physician operators to obtain diagnostic ultrasound (US) images for medical diagnosis including musculoskeletal injury. We hypothesize that these techniques could be expanded to non-expert operators including National Hockey League (NHL) and Olympic athletic trainers to diagnose musculoskeletal injuries in athletes. METHODS: NHL and Olympic athletic trainers received a brief course on musculoskeletal US. Remote guidance musculoskeletal examinations were conducted by athletic trainers, consisting of hockey groin hernia, knee, ankle, elbow, or shoulder evaluations. US images were transmitted to remote experts for interpretation. RESULTS: Groin, knee, ankle, elbow, or shoulder images were obtained on 32 athletes; all real-time US video stream and still capture images were considered adequate for diagnostic interpretation. CONCLUSIONS: This experience suggests that US can be expanded for use in locations without a high level of on-site expertise. A non-physician with minimal training can perform complex, diagnostic-quality examinations when directed by a remote-based expert.

Outcome and structural integrity after arthroscopic rotator cuff repair using 2 rows of fixation: minimum 2-year follow-up.

BACKGROUND: Although arthroscopic repairs of the rotator cuff are becoming increasingly popular, security of fixation remains a concern. Two-row repairs have been described, but clinical outcome reports have primarily involved open techniques. HYPOTHESIS: An arthroscopic repair technique that uses 2 rows of fixation produces satisfactory outcome and structural integrity by ultrasonography. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Forty-eight patients (52 shoulders) with a full-thickness, but fully reducible, rotator cuff tear who met the inclusion criteria were treated with an arthroscopic rotator cuff repair using 2 rows of suture anchors. The mean tear size was 2.47 cm (range, 1-4 cm). Patients were evaluated by subjective functional assessment (L'Insalata Shoulder Rating Questionnaire), clinical examination, including measured strength testing, and ultrasonography. RESULTS: At a mean follow-up of 30 months (minimum of 2 years), functional scores improved from a mean of 42 preoperatively to 93 postoperatively (P < .001). Active range of motion was increased in all measured planes (P < .001). Strength was also increased in elevation (P < .001), external rotation (P < .001), and internal rotation (P = .033). Nine of the 52 shoulders (17%) had evidence of retear or persistent defect on postoperative ultrasonography. There were no differences detected in functional scores between those with an intact repair and those with a defect, but those with an intact repair were stronger in elevation (P = .006) and external rotation (P = .001). CONCLUSION: An arthroscopic 2-row rotator cuff repair produces excellent functional outcome and repair integrity comparable with previously reported open repairs. Presence of a defect after repair did not appear to affect patient-reported function and return to preinjury activity but did affect measured strength.