Introduction of a novel magnetic resonance imaging-based scoring system for assessing disease activity in children with juvenile dermatomyositis.

Objectives: We aimed to develop and assess the reliability of a novel MRI-based scoring system for reporting the severity of MRI findings in children with suspected JDM. Methods: Nine consultant paediatric radiologists independently assessed and scored 40 axial and 30 coronal thigh MR images of children with suspected JDM on two occasions using the juvenile dermatomyositis magnetic resonance Imaging Score (JIS). JIS was calculated for both reads for each plane and each limb, with possible scores ranging from 0 (normal) to 100 (severe). Inter- and intraobserver agreement was calculated using the intraclass correlation coefficient (ICC) and two- and one-way random effects models, respectively. Bland-Altman plots of the difference in JIS against the average JIS were also produced for each rater. Results: Overall, the interobserver reliability and agreement was good-for axial images, JIS ranged from 46.8 to 61.0 [ICC = 0.88 (95% CI: 0.82, 0.92)] for the left limb and 47.9-61.4 [ICC = 0.87 (95% CI: 0.81, 0.92)] for the right limb. For coronal images, JIS ranged from 56.7 to 65.1 [ICC = 0.90 (95% CI: 0.85, 0.95)] for the left limb and 55.7 to 66.8 [ICC = 0.90 (95% CI: 0.84, 0.94)] for the right limb. The intraobserver reliability and agreement was good, with ICC ranging from 0.90 to 0.94. Conclusion: JIS is a semi-objective scoring system with potential to serve as a reliable biomarker of disease severity and response to therapeutic interventions in children with JDM.

Mycobacterium avium-intracellulare: a rare cause of subacromial bursitis.

Septic subacromial bursitis is an uncommon disorder with only a few reported cases in the literature. The most common causative organism is Staphylococcus aureus. We report the case of a 61-year-old female with a septic subacromial bursitis where the causative organism was found to be Mycobacterium avium-intracellulare (MAI). The diagnosis was only made following a biopsy, and we use this case to highlight the importance of recognising the need to consider a biopsy and aspiration in atypical situations.

The British Athletics Muscle Injury Classification grading system as a predictor of return to play following hamstrings injury in professional football players.

OBJECTIVES: Investigate the British Athletics Muscle Injury Classification (BAMIC) grading system as a predictor of return to play (RTP) following primary hamstring strain injury (HSI) and its agreement with the Peetron's classification system in professional footballers. METHODS: A retrospective cohort study of 39 hamstrings strains in a professional English football club were identified. Two musculoskeletal radiologists reviewed historical MRI's and classified them against the BAMIC and Peetron's grading system. Classification, oedema length and cross-sectional area were compared against RTP. RESULTS: Pearson's correlation coefficient demonstrated a weak but statistically significant correlation between BAMIC and RTP (r = 0.32; 95%CI 0.01 to 0.58; p = 0.05). Maximum length of intramuscular oedema demonstrated weak correlations with RTP (r = 0.3; 95%CI -0.02 to 0.56; p = 0.06). Percentage cross sectional demonstrated a weak correlation with RTP (r = 0.02; 95%CI -0.3 to 0.33; p = 0.91). Multiple regression demonstrated that 16% of the variance in RTP was explained by the model. Kappa for the agreement between BAMIC and Peetron's was 0.21 (95%CI 0 to 0.42). CONCLUSIONS: A significant association between the grade of HSI on the BAMIC system and RTP was found. Findings suggest BAMIC could provide valuable prognostic information on the RTP.

In vitro toxicity assessment of chitosan oligosaccharide coated iron oxide nanoparticles.

Iron oxide nanoparticles (INPs) have potential biological, biomedical and environmental applications. These applications require surface modification of the iron oxide nanoparticles, which makes it non-toxic, biocompatible, stable and non-agglomerative in natural and biological surroundings. In the present study, iron oxide nanoparticles (INPs) and chitosan oligosaccharide coated iron oxide nanoparticles (CSO-INPs) were synthesized to evaluate the effect of surface coating on the stability and toxicity of nanoparticles. Comparative in vitro cytotoxicity of nanoparticles was evaluated in HeLa (human cervix carcinoma), A549 (human lung carcinoma) and Hek293 (human embryonic kidney) cells by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay along with flow cytometry study for cell viability, membrane integrity, mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) production. Morphological alteration in nanoparticles treated cells was analyzed by Acridine orange/ethidium bromide double staining and electron microscopy. Synthesized nanoparticles were found to be spherical in shape, well dispersed and stable at various pH values, making them suitable for biomedical and environmental applications. The present study also indicates that the chitosan oligosaccharide coating on iron oxide nanoparticles results in the decrease in cellular damage and moderate ROS production, thereby, significantly decreasing the cytotoxic impact of bare iron oxide nanoparticles.

Intracellular Targeting of the Oncogenic MUC1-C Protein with a Novel GO-203 Nanoparticle Formulation.

PURPOSE: The MUC1-C oncoprotein is an intracellular target that is druggable with cell-penetrating peptide inhibitors. However, development of peptidyl drugs for treating cancer has been a challenge because of unfavorable pharmacokinetic parameters and limited cell-penetrating capabilities. EXPERIMENTAL DESIGN: Encapsulation of the MUC1-C inhibitor GO-203 in novel polymeric nanoparticles was studied for effects on intracellular targeting of MUC1-C signaling and function. RESULTS: Our results show that loading GO-203 into tetrablock polylactic acid (PLA)-polyethylene glycol (PEG)-polypropylene glycol (PPG)-PEG copolymers is achievable and, notably, is enhanced by increasing PEG chain length. In addition, we found that release of GO-203 from these nanoparticles is controllable over at least 7 days. GO-203/nanoparticle treatment of MUC1-C-positive breast and lung cancer cells in vitro was more active with less frequent dosing than that achieved with nonencapsulated GO-203. Moreover, treatment with GO-203/nanoparticles blocked MUC1-C homodimerization, consistent with on-target effects. GO-203/nanoparticle treatment was also effective in downregulating TIGAR, disrupting redox balance, and inhibiting the self-renewal capacity of cancer cells. Significantly, weekly administration of GO-203/nanoparticles to mice bearing syngeneic or xenograft tumors was associated with regressions that were comparable with those found when dosing on a daily basis with GO-203. CONCLUSIONS: These findings thus define an effective approach for (i) sustained administration of GO-203 in polymeric PLA-(PEG-PPG-PEG) nanoparticles to target MUC1-C in cancer cells and (ii) the potential delivery of other anticancer peptide drugs.

Primary total hip arthroplasty with a proximally porous-coated femoral stem.

BACKGROUND: The use of cementless, proximally porous-coated femoral stems for total hip arthroplasty has increased in popularity. The purpose of the present report was to examine the five to ten-year results associated with the use of a so-called second-generation circumferentially proximally porous-coated titanium-alloy stem. METHODS: Between 1991 and 1994, 123 Harris-Galante Multilock femoral stems were implanted in 101 patients. The average age of the patients at the time of surgery was 53.8 years. The patients were followed prospectively and were reevaluated at a minimum of five years postoperatively. No patient was lost to follow-up. Twenty-five patients (thirty hips) were interviewed by telephone, and four patients (five hips) died during the study period because of problems that were unrelated to the operation. The remaining seventy-two patients (eighty-eight hips) had a minimum of five years of clinical and radiographic follow-up. RESULTS: The average duration of follow-up was seventy-eight months. At the time of the most recent follow-up, the average Harris Hip Score was 95 points. Eighty-seven (99%) of eighty-eight stems were biologically stable, with eighty-four hips (95%) having osseous ingrowth and three hips (3%) having stable fibrous fixation. One stem was revised because of loosening. Thirty-three hips (38%) had minimal proximal osteolysis, and no hip had diaphyseal osteolysis. Seventy-two hips (82%) had some degree of stress-shielding in the proximal metaphysis, but only two hips had cortical resorption. None of these patients required additional surgery, and all reported a satisfactory outcome. CONCLUSIONS: Given the young age and high activity level of these patients, this stem fared well: the levels of patient function and satisfaction were high, the rates of loosening and revision were very low, and distal osteolysis did not occur. Osseous fixation occurred reliably. Proximal stress-shielding was seen but did not seem to be clinically important.

Reconstruction of a ruptured patellar tendon with achilles tendon allograft following total knee arthroplasty.

BACKGROUND: Rupture of the patellar tendon after total knee arthroplasty is a rare and debilitating complication. Proper surgical management of this condition remains controversial. The purpose of this study was to review the results of reconstruction of a ruptured patellar tendon with an Achilles tendon allograft following total knee arthroplasty. METHODS: We reviewed our experience with the use of a fresh-frozen Achilles tendon allograft with an attached calcaneal bone graft to restore extensor function in nine patients with patellar tendon rupture following total knee arthroplasty (five primary and four revision). All patients were examined clinically and radiographically at an average of twenty-eight months. RESULTS: The average knee and functional scores improved from 26 and 14 points, respectively, before the surgery to 81 and 53 points after the surgery. The average extensor lag decreased from 44 degrees preoperatively to 3 degrees postoperatively, and the average range of motion of the knee increased from 88 degrees to 107 degrees. Two grafts failed in the early postoperative period. Both were repaired successfully. Radiographs showed an average proximal patellar migration of 17.8 mm, which did not appear to affect extensor function. CONCLUSIONS: This short-term follow-up study showed that once an Achilles allograft has healed, it can serve as a reliable reconstruction of a ruptured patellar tendon following total knee arthroplasty. This technique may be particularly suited for patients in whom the extensor mechanism was compromised by multiple prior operations. Continued follow-up is necessary to determine the long-term durability of these results.

The effect of a 5-day space flight on the immature rat spine.

BACKGROUND CONTEXT: Spaceflight has many reported effects upon the musculoskeletal system structure and function. This study was designed to determine the effect of a 5-day flight on the rat spine. METHODS: In September 1991, 8 neonatal rats were flown aboard the Space Shuttle Columbia flight STS-48 during a 5-day mission. Upon return to earth, the spines were dissected, frozen and shipped to our laboratory. Matched ground-based rats were used as controls. The spines were radiographed and then slowly thawed. Individual vertebrae were subjected to compressive biomechanical testing using an Instron tester (Instron Corp, Canton, MA, USA) and then processed for determination of calcium and phosphorus content. The intervertebral discs were placed in physiological saline and the stress-relaxation characteristics measured. The discs were then lyophilized and assayed for collagen and proteoglycan content. Disc height on radiographs was measured by image analysis. RESULTS: After space flight, the heights of the discs were found to be 150 to 200 microns greater, although the values were not statistically significant. There was no difference in the resiliency of the thoracic discs as determined by stress-relaxation. However, in the lumbar discs, space flight increased the resiliency (p<.01). There was no difference in water content. In both the thoracic and lumbar discs there was a 3.3-fold increase in hydroxyproline-proteoglycan ratio after space flight. However, because of the small sample size, these values were not statistically significant. In the vertebrae, there was no difference in calcium-phosphate ratio or compressive strength. CONCLUSIONS: These data suggest that even after a short 5-day flight, the spine begins to undergo biomechanical and biochemical changes. In addition, the weightless environment in space may provide a good model to study the effects of immobilization on earth.

The use of customized TKA implants for increased efficiency in the OR.

Efficiency in surgical procedures saves time and money and can decrease medical complications. Several sources of inefficiency exist in the operating room, including preoperative and intraoperative. The instruments used during TKA are frequently redundant. Customized instruments and implants can improve efficiency by reducing steps. Additional benefits may include improved alignment and kinematics. This chapter addresses the various sources of inefficiency, provides suggestions to overcome them, and introduces the concept of customized guides and implants as a method to improve efficiency.

Outcomes of robotic arm-assisted unicompartmental knee arthroplasty.

Early outcomes of unicompartmental knee arthroplasty performed with a robotically assisted navigation system have been favorable. The surgical technique enhances accuracy of bone preparation and component positioning. Technical errors of the system have been minimal. The surgeon's learning curve is not adversely affected. Early patient outcomes are excellent and complications minimal. Further follow-up and study will help to determine whether these early outcomes are sustained over time.

Long-stem cemented calcar replacement arthroplasty for proximal femoral bone loss.

Revision total hip arthroplasty with accompanying bone defects may require calcar replacement prostheses to restore hip stability and function. Twenty-nine hips in 27 patients were followed for a mean of 41 months (range, 24-101 months). The average Harris Hip Score increased from 34 to 82 points. Acceptable cement mantles (A, B, C1) were present in all cases. Three femoral components (10.3%) were re-revised as a result of aseptic loosening. Two others (6.9%) were loose by radiographic criteria. Thus, 24 (82.8%) of the 29 index femoral components were rigidly fixed according to radiographic criteria, whereas 26 (89.7%) still were in place at the time of review. The results of this study suggest that long-stem cemented calcar-replacement prostheses with modern cementing technique are a reasonable option in femoral revision arthroplasties involving proximal bone loss.

Surgical approaches to total hip arthroplasty.

Surgical exposure of the hip for trauma, infection, or reconstruction can be adequately accomplished through a variety of surgical approaches. This article describes in detail five classic approaches to the hip: Smith-Petersen (anterior), Watson-Jones (anterolateral), Hardinge (direct lateral), transtrochanteric, and posterolateral. In addition, recently described mini-incision posterior and anterior approaches are outlined.

Guidelines and alternatives for neuraxial anesthesia and venous thromboembolism prophylaxis in major orthopedic surgery.

Neuraxial anesthesia during major orthopedic surgery, combined with venous thromboembolism prophylaxis, is generally safe and well tolerated, with potential benefits over general anesthesia. The risk of spinal/epidural hematoma, a rare but very serious complication, can be minimized by careful patient selection and attention to anesthetic technique. This risk is further reduced with the use of peripheral nerve blocks in place of neuraxial anesthesia.

Long-term suppression of infection in total joint arthroplasty.

Optimal treatment for a chronic infected prosthesis is the removal of infected and necrotic tissue and all the components of the prosthesis with staged revision in conjunction with systemic antibiotics. If this is not possible because of the poor general condition of the patient, because of unacceptable functional results secondary to removal of the prosthesis, or because the patient refuses surgery in an attempt to salvage the infected prosthesis, a reasonable alternative is long-term oral suppressive antibiotic therapy for maintenance of a functioning prosthesis. Prompt recognition with rapid debridement and initiation of antibiotic therapy seems crucial. Our study confirms a favorable outcome of maintenance of functioning prostheses in 86.2% of patients after a mean followup of 5 years. All patients had initial debridement with 4 to 6 weeks of systemic antibiotic therapy. Advanced age did not seem to predict poor outcome. Joint location, duration of symptoms, and the time of onset of infection did not predict success or failure. The overall success rate for Staphylococcus aureus prosthetic joint infection was 69% after a mean followup of 5 years. The ideal regimen and optimal duration of oral suppressive therapy for a favorable outcome is not well-established and needs additional data with prospective multicenter studies.