Analysis of complications and revisions after spine surgery in 270 multiple myeloma patients with spinal involvement.

BACKGROUND CONTEXT: Patients with multiple myeloma (MM) are at increased risk of infections and suffer from poor bone quality due to their disseminated malignant bone disease. Therefore, postoperative complications may occur following surgical treatment of MM lesions. PURPOSE: In this study, we aimed to determine the incidence of postoperative complications and retreatments after spinal surgery in MM patients. Additionally, we sought to identify risk factors associated with complications and retreatments. STUDY DESIGN: Retrospective cohort study. PATIENT SAMPLE: In total, 270 patients with MM who received surgical treatment for spinal involvement between 2008 and 2021 were included. OUTCOME MEASURES: The incidence of perioperative complications within 6 weeks and reoperations within 2.5 years and individual odds ratios for factors associated with these complications and reoperations. METHODS: Data were collected through manual chart review. Hosmer and Lemeshow's purposeful regression method was used to identify risk factors for complications and reoperations. RESULTS: The median age of our cohort was 65 years (SD = 10.8), and 58% were male (n = 57). Intraoperative complications were present in 24 patients (8.9%). The overall 6-week complication rate after surgery was 35% (n = 95). The following variables were independently associated with 6-week complications: higher Genant grading of a present vertebral fracture (OR 1.41; 95% CI 1.04-1.95; p = .031), receiving intramuscular or intravenous steroids within a week prior to surgery (OR 3.97; 95% CI 1.79-9.06; p = .001), decompression surgery without fusion (OR 6.53; 95% CI 1.30-36.86; p = .026), higher creatinine levels (OR 2.18; 95% CI 1.19-5.60; p = .014), and lower calcium levels (OR 0.58; 95% CI 0.37-0.88; p = .013). A secondary surgery was indicated for 53 patients (20%), of which 13 (4.8%) took place within two weeks after the initial surgery. We additionally discovered factors associated with retreatments, which are elucidated within the manuscript. CONCLUSION: The goal of surgical treatment for MM bone disease is to enhance patient quality of life and reduce symptom burden. However, postoperative complication rates remain relatively high after spine surgery in patients with MM, likely attributable to both inherent characteristics of the disease and patient comorbidities. The risk for complications and secondary surgeries should be explored and a multidisciplinary approach is crucial.

Prospective study for establishing minimal clinically important differences in patients with surgery for lower extremity metastases.

BACKGROUND: The clinical relevance of patient-reported outcomes score changes is often unclear. Especially in patients undergoing surgery due to lower extremity metastases - where surgery is performed in the palliative setting and the goal is to optimize functional mobility, relieve pain and improve overall quality of life. This study assessed the minimal clinically important difference (MCID) of Patient-Reported Outcomes Measurement Information System (PROMIS) Pain Interference, Cancer-specific Physical Function, and Global (Physical and Mental Health) in patients treated surgically for impending or completed pathologic fractures. METHODS: Patients undergoing surgery for osseous metastasis of the lower extremity because of an impending or completed pathologic fracture were consecutively enrolled in this tertiary center study. Patients completed the three PROMIS questionnaires preoperatively (n = 56) and at postoperative follow-up (n = 33) assessment one to three months later. Of the 23 patients that did not complete the postoperative survey, 5 patients died within 1-3 months and 18 patients were alive at 3-months but did not respond or show up at their postoperative consult. Thirty-one patients (94%) of the 33 included patients reported at least minimal improvement and two patients (6.1%) no change 1-3 months after the surgery based on an anchor-based approach. RESULTS: The PROMIS MCIDs (95% confidence interval) for Pain Interference was 7.5 (3.4-12), Physical Function 4.1 (0.6-7.6), Global Physical Health 4.2 (2.0-6.6), and Global Mental Health 0.8 (-4.5-2.9). CONCLUSION: This prospective study successfully defined a MCID for PROMIS Pain Interference of 7.5 (3.4-12), PROMIS Physical Function of 4.1 (0.6-7.6), and Global Physical Health of 4.2 (2.0-6.6) in patients with (impending) pathological fractures due to osseous metastases in the lower extremity; no MCID could be established for PROMIS Global Mental Health. Defining a narrower MCID value for each subpopulation requires a large, prospective, multicenter study. Nevertheless, the provided MCID values allow guidance to clinicians to evaluate the impact of surgical treatment on a patient's QoL. LEVEL OF EVIDENCE: Level II Diagnostic study.

Adipose tissue density on CT as a prognostic factor in patients with cancer: a systematic review.

BACKGROUND: Predicting oncologic outcomes is essential for optimizing the treatment for patients with cancer. This review examines the feasibility of using Computed Tomography (CT) images of fat density as a prognostic factor in patients with cancer. METHODS: A systematic literature search was performed in PubMed, Embase and Cochrane up to March 2020. All studies that mentioned using subcutaneous or visceral adipose tissue (SAT and VAT, respectively) CT characteristics as a prognostic factor for patients with cancer were included. The primary endpoints were any disease-related outcomes in patients with cancer. RESULTS: After screening 1043 studies, ten studies reporting a total of 23 - ten for SAT and thirteen for VAT - comparisons on survival, tumor recurrence and postsurgical infection were included. All ten studies included different types of malignancy: six localized, two metastatic disease, and two both. Five different anatomic landmarks were used to uniformly measure fat density on CT: lumbar (L)4 (n = 4), L3 (n = 2), L4-L5 intervertebral space (n = 2), L5-S1 intervertebral space (n = 1), and the abdomen (n = 1). Overall, six of ten SAT comparisons (60%) and six of thirteen VAT comparisons (46%) reported a significant (p < .05) association of increased SAT or VAT density with an adverse outcome. All remaining nonsignificant comparisons, except one, deviated in the same direction of being predictive for adverse outcomes but failed to reach significance. The median hazard ratio (HR) for the nine SAT and thirteen VAT associations where HRs were given were 1.45 (95% confidence interval [CI] 1.01-1.97) and 1.90 (95% CI 1.12-2.74), respectively. The binomial sign test and Fisher's method both reported a significant association between both SAT and VAT and adverse outcomes. CONCLUSION: This review may support the feasibility of using SAT or VAT on CT as a prognostic tool for patients with cancer in predicting adverse outcomes such as survival and tumor recurrence. Future research should standardize radiologic protocol in prospective homogeneous series of patients on each cancer diagnosis group in order to establish accurate parameters to help physicians use CT scan defined characteristics in clinical practice.

What Factors are Associated With Quality Of Life, Pain Interference, Anxiety, and Depression in Patients With Metastatic Bone Disease?

BACKGROUND: It would be helpful for the decision-making process of patients with metastatic bone disease to understand which patients are at risk for worse quality of life (QOL), pain, anxiety, and depression. Normative data, and where these stand compared with general population scores, can be useful to compare and interpret results of similar patients or patient groups, but to our knowledge, there are no such robust data. QUESTIONS/PURPOSES: We wished (1) to assess what factors are independently associated with QOL, pain interference, anxiety, and depression in patients with metastatic bone disease, and (2) to compare these outcomes with general US population values. METHODS: Between November 2011 and February 2015, 859 patients with metastatic bone disease presented to our orthopaedic oncology clinic; 202 (24%) were included as they completed the EuroQOL-5 Dimension (EQ-5DTM), PROMIS® Pain Interference, PROMIS® Anxiety, and PROMIS® Depression questionnaires as part of a quality improvement program. We did not record reasons for not responding and found no differences between survey respondents and nonrespondents in terms of age (63 versus 64 years; p = 0.916), gender (51% men versus 47% men; p = 0.228), and race (91% white versus 88% white; p = 0.306), but survey responders were more likely to be married or living with a partner (72%, versus 62%; p = 0.001). We assessed risk factors for QOL, pain interference, anxiety, and depression using multivariable linear regression analysis. We used the one-sample signed rank test to assess whether scores differed from US population averages drawn from earlier large epidemiologic studies. RESULTS: Younger age (ß regression coefficient [ß], < 0.01; 95% CI, 0.00-0.01; p = 0.041), smoking (ß, -0.12; 95% CI, -0.22 to -0.01; p = 0.026), pathologic fracture (ß, -0.10; 95% CI, -0.18 to -0.02; p = 0.012), and being unemployed (ß, -0.09; 95% CI, -0.17 to -0.02; p = 0.017) were associated with worse QOL. Current smoking status was associated with more pain interference (ß, 6.0; 95% CI, 1.6-11; p = 0.008). Poor-prognosis cancers (ß, 3.8; 95% CI, 0.37-7.2; p = 0.030), and pathologic fracture (ß, 6.3; 95% CI, 2.5-7.2; p = 0.001) were associated with more anxiety. Being single (ß, 5.9; 95% CI, 0.83-11; p = 0.023), and pathologic fracture (ß, 4.4; 95% CI, 0.8-8.0; p = 0.017) were associated with depression. QOL scores (0.68 versus 0.85; p < 0.001), pain interference scores (65 versus 50; p < 0.001), and anxiety scores (53 versus 50; p = 0.011) were worse for patients with bone metastases compared with general US population values, whereas depression scores were comparable (48 versus 50; p = 0.171). CONCLUSIONS: Impending pathologic fractures should be treated promptly to prevent deterioration in QOL, anxiety, and depression. Our normative data can be used to compare and interpret results of similar patients or patient groups. Future studies could focus on specific cancers metastasizing to the bone, to further understand which patients are at risk for worse patient-reported outcomes. LEVEL OF EVIDENCE: Level III, prognostic study.

Neurologic Outcomes After Radiation Therapy for Severe Spinal Cord Compression in Multiple Myeloma: A Study of 162 Patients.

BACKGROUND: Bone destruction is the most frequent disease-defining clinical feature of multiple myeloma (MM), resulting in skeletal-related events such as back pain, pathological fractures, or neurologic compromise including epidural spinal cord compression (ESCC). Up to 24% of patients with MM will be affected by ESCC. Radiation therapy has been proven to be highly effective in pain relief in patients with MM. However, a critical knowledge gap remains with regard to neurologic outcomes in patients with high-grade ESCC treated with radiation. METHODS: We retrospectively included 162 patients with MM and high-grade ESCC (grade 2 or 3) who underwent radiation therapy of the spine between January 2010 and July 2021. The primary outcome was the American Spinal Injury Association (ASIA) score after 12 to 24 months, or the last known ASIA score if the patient had had a repeat treatment or died. Multivariable logistic regression was used to assess factors associated with poor neurologic outcomes after radiation, defined as neurologic deterioration or lack of improvement. RESULTS: After radiation therapy, 34 patients (21%) had no improvement in their impaired neurologic function and 27 (17%) deteriorated neurologically. Thirty-six patients (22%) underwent either surgery or repeat irradiation after the initial radiation therapy. There were 100 patients who were neurologically intact at baseline (ASIA score of E), of whom 16 (16%) had neurologic deterioration. Four variables were independently associated with poor neurologic outcomes: baseline ASIA (odds ratio [OR] = 6.50; 95% confidence interval [CI] = 2.70 to 17.38; p < 0.001), Eastern Cooperative Oncology Group (ECOG) performance status (OR = 6.19; 95% CI = 1.49 to 29.49; p = 0.015), number of levels affected by ESCC (OR = 4.02; 95% CI = 1.19 to 14.18; p = 0.026), and receiving steroids prior to radiation (OR = 4.42; 95% CI = 1.41 to 16.10; p = 0.015). CONCLUSIONS: Our study showed that 38% of patients deteriorated or did not improve neurologically after radiation therapy for high-grade ESCC. The results highlight the need for multidisciplinary input and efforts in the treatment of high-grade ESCC in patients with MM. Future studies will help to improve patient selection for specific and standardized treatments and to clearly delineate which patients are likely to benefit from radiation therapy. LEVEL OF EVIDENCE: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Edema-producing activity of group A streptococcal polysaccharide and its possible role in the pathogenesis of cell wall-induced polyarthritis.

Edematous responses were induced in the limbs of Sprague-Dawley rats by intravenous, intraperitoneal, or intra-articular injections of group-specific polysaccharide (PS) isolated from the cell walls of group A streptococci. After intravenous injection of the edema-producing PS, vascular permeability increase (measured by 125I-human serum albumin) was detected in the limbs, but not in the heart, lungs, spleen, liver, thymus, kidney, skin, skeletal muscle, submandibular lymph nodes, mesenteric lymph nodes, or ascending colon. This indicates a selective effect on vascular endothelium of the joints. Evidence to suggest that the edema-producing activity of the PS might play an important role in the pathogenesis of cell wall-induced polyarthritis included the following: (a) the presence of edema-producing activity in arthropathogenic cell wall preparations; (b) cell wall preparations without edema-producing activity were significantly less active in inducing arthritis than were those which contained edema-producing activity; and (c) the addition of edema-producing PS to cell wall preparations increased both the incidence and the severity of arthritis.

Persistence of group a streptococcal cell walls related to chronic inflammation of rabbit dermal connective tissue.

Antibodies specific for the mucopeptide and group-specific C polysaccharide antigens of Group A streptococcal cell walls were prepared by acid dissociation of immune precipitates, and labeled with either fluorescein or (125)I. Employing both fluorescent and radioautographic procedures the persistence of the antigens was followed in skin sites injected with cell wall fragments. Both antigens persisted within macrophages for at least 54 days in those animals which developed no chronic tissue response. In animals which did develop chronic nodular lesions the concentration of antigen decreased as the inflammatory process subsided. Lesion activity was thus associated with the presence of cell wall material. The fate of these antigens was also determined following the intradermal injection of intact Group A streptococcal cells. Cell wall antigens persisted in the tissue site considerably longer than morphologically identifiable streptococci, indicating that cell wall fragments are released during dismantling of streptococci in phagocytic cells.

Biological characterization of an immunosuppressant from group A streptococci.

A component in extracts of Group A streptococci suppresses antibody formation in mice against heterologous erythrocyte and protein antigens. Large doses are not toxic and repeated injection does not change its effectiveness. It is most effective when injected 1 or 2 days before antigen and it is not suppressive when given after antigen. The active factor occurs as a large polydisperse complex and activity can be increased 10- to 25-fold by filtration through Sepharose 2B. Both direct (gammaM) and indirect (gammaG) antibody-forming cells are suppressed in primary and secondary responses. Injection before a primary response does not reduce memory cell development. It increases rather than depresses the "background" antibody-forming cells to sheep erythrocytes, and is equally effective if injected intraperitoneally or intravenously. Ribonuclease increases activity while deoxyribonuclease has no effect. Proteases destroy immunosuppressive action.

Relation of rheumatic-like cardiac lesions of the mouse to localization of group A streptococcal cell walls.

Mice injected intraperitoneally with isolated cell wall fragments of Group A streptococci develop a carditis similar to that previously observed in mice injected with crude extracts of this organism. Neither the soluble cytoplasmic components of Group A streptococcal cells nor the nonfragmented cell walls produced carditis in this experimental model. Fluorescein and (125)I-labeled antibodies specific for Group A streptococcal cell wall antigens were used to demonstrate that, for 5 wk after injection, cell wall material is localized around the sites of active lesions in the heart. In addition, the cell wall antigen accumulates in the liver, spleen, mediastinal lymph nodes, and the adjacent loose connective tissue, where it persists for at least 10 wk.

Treatment of experimental erosive arthritis in rats by injection of the muralytic enzyme mutanolysin.

A single intravenous injection into rats of 0.4 mg of the muralytic enzyme mutanolysin, given as long as 3 d after an arthropathic dose of peptidoglycan-polysaccharide polymers derived from group A streptococci (PG-APS), resulted in a complete resolution of acute arthritis and the prevention of chronic joint disease. When administration of mutanolysin was delayed until 14 d after the injection of PG-APS, a great reduction in the severity of chronic inflammation was still observed. Quantitation of the amount of PG-APS present in the limbs, spleen, and liver by a solid phase enzyme-linked immunoassay indicated that the tissues of mutanolysin-treated rats contained as much PG-APS as tissues of PBS-treated control rats. In addition, rats treated with mutanolysin immediately after receiving an intraperitoneal injection of PG-APS developed a transient limb edema similar to that seen in rats after the injection of PG-APS digested to a small fragment size in vitro with mutanolysin. We hypothesize that mutanolysin acts in vivo by degrading PG-APS to small fragments that persist but are no longer arthropathic.

Arthritis in rats after systemic injection of streptococcal cells or cell walls.

Further investigation of the biological properties of streptococcal cells and their components has produced a model of erosive synovitis in rats. A single intraperitoneal injection of an aqueous suspension of whole cell sonicate of group A streptococci into Sprague-Dawley rats induced an acute arthritis which evolved into a prolonged inflammatory process characterized by several complete or partial remissions, joint deformity, and ankylosis. The toxic moiety is a peptidoglycan-polysaccharide fragment of the cell wall which persists in tissue. Histologic features of the arthritis include an acute exudative phase followed by an erosive synovitis that leads to destruction of cartilage and subchondral bone and fibrous ankylosis of the joints. The arthropathic properties of whole cell sonicates of several species of streptococci are compared along with studies of the ability of heat-killed, whole cells of groups A, B, and C streptococci to induce arthritis in rats. Whole cells induce arthritis after a latent period of 57-120 days when group A cells are injected and 7-10 days when group B cells are tested.

Lipopolysaccharide induces recurrence of arthritis in rat joints previously injured by peptidoglycan-polysaccharide.

Rat ankle joints injected intraarticularly with 5 micrograms of group A streptococcal peptidoglycan-polysaccharide (PG-APS) developed an acute course of arthritis. Recurrence of arthritis was induced in 100% of these joints by intravenous injection of as little as 10 micrograms of Salmonella typhimurium lipopolysaccharide (LPS) 3 wk after intraarticular injection. This reaction was similar in athymic and euthymic rats. Buffalo rats were less susceptible than Lewis or Sprague-Dawley rats. Neisseria gonorrhoeae, Yersinia enterocolitica, and Escherichia coli LPS, and S. typhimurium Re mutant LPS, were also active. Re mutant LPS activity was greatly reduced by mixing with polymyxin B. E. coli lipid A was weakly active. An acute synovitis of much less incidence, severity, and duration was seen in contralateral joints injected initially with saline, and in ankle joints of naive, previously uninjected rats after intravenous LPS injection. The intravenous injection of the muramidase mutanolysin on day 0 or 7 after intraarticular PG-APS injection prevented LPS-induced recurrence of arthritis. These studies suggest that the phlogistic activities of lipid A and peptidoglycan might interact in an inflammatory disease process, and that LPS may play a role in recurrent episodes of rheumatoid arthritis or reactive arthritis.

Immunosuppressant from group A streptococci.

A cytoplasmic component of group A streptococci suppresses both 19S and 7S antibody responses of mice to sheep erythrocytes. Partial purification is achieved by differential centrifugation and gel filtration. When the direct and indirect hemolytic plaque techniques are used, a single injection of this group A material given before injection of erythrocytes produces more than 90-percent suppression of either primary or secondary immune response.

Management of metastatic humeral fractures: Variations according to orthopedic subspecialty, tumor characteristics.

HYPOTHESIS: This study assessed, if there was a difference in surgical decision making for metastatic humeral lesions based on; orthopaedic subspecialty, tumor characteristics. STUDY TYPE: Cross sectional survey study. MATERIALS AND METHODS: Twenty-four case scenarios were created by combining: tumor type, life expectancy, fracture type, and anatomical location. Participants were asked for every case: what treatment would you recommend? Participants were 78 (48%) orthopaedic oncologists and 83 (52%) orthopaedic surgeons that were not regularly involved in the treatment of bone tumors. RESULTS: There was a difference between orthopaedic oncologists and other subspecialty surgeons in recommendation for specific treatments: intramedullary nailing was less often recommended by orthopaedic oncologists (53%, 95%CI: 47-59) compared to other surgeons (62%, 95%CI: 57-67) (p=0.023); while endoprosthetic reconstruction (orthopaedic oncologists: 8.8% [95%CI: 6.6-11], other surgeons: 3.6%[95%CI: 2.3-4.8], p<0.001) and plate-screw fixation (orthopaedic oncologists: 19%[95%CI: 14-25], other surgeons: 9.5%[95%CI: 5.9-13], p=0.003) were more often recommended by orthopaedic oncologists. There was no difference in recommendation for nonoperative management. There were differences in recommendation for specific treatments based on tumor type, life expectancy, and anatomical location, but not fracture type. DISCUSSION: Subspecialty training and patient and tumor characteristics influence the decision for operative management and the decision for a specific implant in metastatic humeral fractures. LEVEL OF EVIDENCE: Level 3.

Degradation of endogenous bacterial cell wall polymers by the muralytic enzyme mutanolysin prevents hepatobiliary injury in genetically susceptible rats with experimental intestinal bacterial overgrowth.

Jejunal self-filling blind loops with subsequent small bowel bacterial overgrowth (SBBO) induce hepatobiliary injury in genetically susceptible Lewis rats. Lesions consist of portal tract inflammation, bile duct proliferation, and destruction. To determine the pathogenesis of SBBO-induced hepatobiliary injury, we treated Lewis rats with SBBO by using several agents with different mechanisms of activity. Buffer treatment, ursodeoxycholic acid, prednisone, methotrexate, and cyclosporin A failed to prevent SBBO-induced injury as demonstrated by increased plasma aspartate aminotransferase (AST) and elevated histology scores. However, hepatic injury was prevented by mutanolysin, a muralytic enzyme whose only known activity is to split the beta 1-4 N-acetylmuramyl-N-acetylglucosamine linkage of peptidoglycan-polysaccharide (PG-PS), a bacterial cell wall polymer with potent inflammatory and immunoregulatory properties. Mutanolysin therapy started on the day blind loops were surgically created and continued for 8 wk significantly diminished AST (101 +/- 37 U/liter) and liver histology scores (2.2 +/- 2.7) compared to buffer-treated rats (228 +/- 146 U/liter, P < 0.05, 8.2 +/- 1.9, P < 0.001 respectively). Mutanolysin treatment started during the early phase of hepatic injury, 16-21 d after surgery, decreased AST in 7 of 11 rats from 142 +/- 80 to 103 +/- 24 U/liter contrasted to increased AST in 9 of 11 buffer-treated rats from 108 +/- 52 to 247 +/- 142 U/liter, P < 0.05. Mutanolysin did not change total bacterial numbers within the loop, eliminate Bacteroides sp., have in vitro antibiotic effects, or diminish mucosal PG-PS transport. However, mutanolysin treatment prevented elevation of plasma anti-PG antibodies and tumor necrosis factor-alpha (TNF alpha) levels which occurred in buffer treated rats with SBBO and decreased TNF alpha production in isolated Kupffer cells stimulated in vitro with PG-PS. Based on the preventive and therapeutic activity of this highly specific muralytic enzyme, we conclude that systemic uptake of PG-PS derived from endogenous enteric bacteria contributes to hepatobiliary injury induced by SBBO in susceptible rat strains.

Quality of life after resection of a chordoma of the mobile spine.

AIMS: The aim of the study was to compare measures of the quality of life (QOL) after resection of a chordoma of the mobile spine with the national averages in the United States and to assess which factors influenced the QOL, symptoms of anxiety and depression, and coping with pain post-operatively in these patients. PATIENTS AND METHODS: A total of 48 consecutive patients who underwent resection of a primary or recurrent chordoma of the mobile spine between 2000 and 2015 were included. A total of 34 patients completed a survey at least 12 months post-operatively. The primary outcome was the EuroQol-5 Dimensions (EQ-5D-3L) questionnaire. Secondary outcomes were the Patient-Reported Outcome Measurement Information System (PROMIS) anxiety, depression and pain interference questionnaires. Data which were recorded included the indication for surgery, the region of the tumour, the number of levels resected, the status of the surgical margins, re-operations, complications, neurological deficit, length of stay in hospital and rate of re-admission. RESULTS: The median EQ-5D-3L score was 0.71 (interquartile range (IQR) 0.44 to 0.79) which is worse than the national average in the United States of 0.85 (p < 0.001). Anxiety (median: 55 (IQR 49 to 61), p = 0.031) and pain (median: 61 (IQR 56 to 68), p < 0.001) were also worse than the national average in the United States (50), while depression was not (median: 52 (IQR 38 to 57), p = 0.513). Patients who underwent a primary resection had better QOL and less anxiety, depression and pain compared with those who underwent resection for recurrent or residual disease. The one- and five-year probabilities were 0.96 and 0.74 for survival, 0.07 and 0.25 for tumour recurrence, and 0.02 and 0.16 for developing distant metastasis. A total of 25 local complications occurred in 20 patients (42%), and there were 50 systemic and other complications in 25 patients (52%) within 90 days. CONCLUSION: These patient reported outcomes and oncological and surgical outcomes can be used when counselling patients and to aid decision-making when planning surgery. Cite this article: Bone Joint J 2017;99-B:979-86.

Functional and oncological outcome after surgical resection of the scapula and clavicle for primary chondrosarcoma.

PURPOSE: The scapula is a relatively common site for chondrosarcoma to develop in contrary to the clavicle, which is rarely affected by these tumors. The aim of this study is to determine the functional and oncological outcome for patients treated operatively for scapular or clavicular chondrosarcoma. METHODS: In this single-center retrospective study, we included a sample of 20 patients that received the diagnosis of a primary chondrosarcoma of the scapula or clavicle. Of the surviving patients, the functional function was assessed using the DASH and the PROMIS Physical Function-Upper Extremity. Patients were longitudinally tracked for their oncological outcome. RESULTS: All patients were followed for at least 2 years or until death. The mean age of the cohort was 47 years. Eighteen patients suffered from a chondrosarcoma of the scapula, and in 2 patients, the tumor was located in the clavicle. Metastasis, local recurrence and a higher tumor grade were all associated with a decreased overall survival. For the patients with a chondrosarcoma of the scapula, the average DASH score was 16 ± 16 and the mean PROMIS Physical Function-Upper Extremity score was 48 ± 10. Patients with both an intact rotator cuff and glenoid had a better physical function. CONCLUSIONS: Upper extremity function after (partial) scapulectomy varied depending on whether the glenoid was spared and whether a functioning shoulder abductor remained. When the resection spared these structures, then excellent functional outcomes were reported. Oncologic outcomes depended upon the grade of the tumor and whether local recurrence and metastases occurred.

Microangiographic studies of experimental erosive synovitis in rats.

Chronic remittent erosive synovitis, which is clinically, radiologically and pathologically similar to rheumatoid arthritis in man, can be produced in rats by systemic injection of cell wall fragments isolated from Group A streptococci. Because of our desire to study the synovial microvasculature in this experimental model, we developed a reliable microangiographic technique to document these changes. This paper describes the first reported microangiographic studies of rat joints and discusses the microvascular changes that parallel the previously reported radiographic and histologic findings. As the arthritis progresses, as judged by clinical and radiographic parameters, early synovial hypervascularity associated with developing hyperplastic synovium gives way to a more obliterative hypovascular pattern associated with chronic erosions, periosteal reaction, and fibrous ankylosis. Microangiography offers an additional and helpful modality by which to investigate synovial microvascular morphology as well as the pathophysiology of joint destruction during erosive synovitis.

Streptococcal antigen-induced dislocation and dysplasia of the hip in newborn rats. Radiologic and histologic evaluation of a model of congenital dislocation of the hip.

Dislocation of the hip developed in 62% of newborn rats with streptococcal antigen-induced synovitis. Age at the time of the induction of synovitis is critical since dislocation is not observed in older rats. Synovitis with distention and laxity of the joint capsule is most likely responsible for the hip dislocation. Although congenital dislocation of the hip in children is not mediated by an inflammatory process, the current model of dislocation of the hip in rats is similar in being critically age-dependent, and associated with ligamentous laxity. Our model may be helpful in studying this important clinical entity.

Bone-resorbing activity is expressed by rat macrophages in response to arthropathic streptococcal cell wall polymers.

Rat peritoneal macrophages stimulated in vivo by group A streptococcal peptidoglycan-polysaccharide (PG-APS) resorb bone as measured by solubilization of 45Ca from radiolabeled, devitalized bone chips. Activity was strain-dependent and correlated with the susceptibility of rat strains to PG-APS-induced arthritis. PG-APS-stimulated macrophages from the resistant Buf rat strain were not induced to resorb bone, but ingested equivalent concentrations of PG-APS compared to bone-resorbing macrophages from the arthritis-susceptible Lew strain. Resorptive activity peaked at three to five days and decreased to background levels by 10 days after injection. PG-APS-stimulated macrophages from congenitally athymic Lew rats were as effective as macrophages from heterozygous littermates at resorbing bone. Lew macrophages were also responsive to small, nonarthropathic PG-APS polymers generated by mutanolysin digestion. Resident peritoneal macrophages did not respond to stimulation by PG-APS in vitro. Indomethacin at a concentration of 10 micrograms/ml was an effective blockade against PG-APS-induced macrophage bone resorption in vitro, but catalase was ineffective. These results indicate that expression of rat macrophage bone-resorbing activity reflects genetic regulation of the response to PG-APS rather than a defect in ingestion of these polymers and imply that PG-APS-stimulated, bone-resorbing macrophages may contribute to early, initial bone destruction that occurs in inflammatory arthritis.