Clinical Outcomes of Total Knee Arthroplasty in Patients Who Have Hemophilic Arthropathy: A Prospective Study.

PURPOSE: Total knee arthroplasty (TKA) is considered the gold standard treatment for patients who have advanced hemophilic knee arthropathy (HA). However, special considerations are required for these patients. This prospective study reports on the need for soft-tissue procedures, implant types, complication rates, mean 53.3 months implant survivorship, and patient-reported outcome measures (PROMs) of TKA in hemophilic patients. METHODS: There were twenty primary TKAs that were performed on 15 hemophilic patients from 2012 to 2023. The mean follow-up was 53.3 months (range, 6 to 128; 33.5). The necessity for additional soft tissue procedures, implant type, complications, and revision rates were recorded. Knee Injury and Osteoarthritis Outcome Score, Knee Society Score, Hemophilia-specific Quality of Life Questionnaire for Adults, Haemophilia Activities List, and range of motion, were compared preoperatively and at the last follow-up. RESULTS: At the last follow-up, implant survivorship was 90%. There were two revisions: one for aseptic loosening and one for periprosthetic joint infection. Additional soft tissue procedures included two quadriceps snips (10%). Tibial augments, tibial stubby stems, and both tibial and femoral traditional stems were used in one (5%), four (20%), and one (5%) TKAs, respectively. A constrained posterior-stabilized bearing was necessary in one case. Clinically and statistically significant improvements were found between the preoperative and final follow-up values of all PROMS, knee flexion (73 versus 108°, P < 0.001), and flexion contracture (11 versus 4°, P = 0.002). CONCLUSION: This study showed that TKA, in patients who have HA, is a reliable treatment option that improves knee function and patients' QoL with acceptable implant survival rates at mid-term follow-up (mean 53.3 months). Standard implants and approaches can be used in most cases. Despite good outcomes, hemophilic patients carry additional risks for complications that require specific considerations. It is paramount for these patients to be treated in specialized centers by experienced surgeons to achieve good results.

Chronic hepatitis C virus infections in Switzerland in 2020: Lower than expected and suggesting achievement of WHO elimination targets.

In this multi-method study, we investigated the prevalence of chronic infections with the hepatitis C virus (HCV) in Switzerland in 2020, and assessed Switzerland's progress in eliminating HCV as a public health problem by 2030 with regard to the World Health Organization (WHO) criteria targeting infections acquired during the preceding year ('new transmissions') and HCV-associated mortality. Based on a systematic literature review, the reappraisal of a 2015 prevalence analysis assuming 0.5% prevalence among the Swiss population and data from many additional sources, we estimated the prevalence among subpopulations at increased risk and the general population. For new transmissions, we evaluated mandatory HCV notification data and estimated unreported new transmissions based on subpopulation characteristics. For the mortality estimate, we re-evaluated a previous mortality estimate 1995-2014 based on new data on comorbidities and age. We found a prevalence of ≤0.1% among the Swiss population. Discrepancies to the 2015 estimate were explained by previous (i) underestimation of sustained virologic response numbers, (ii) overestimation of HCV prevalence among PWID following bias towards subgroups at highest risk, (iii) overestimation of HCV prevalence among the general population from inclusion of high-risk persons and (iv) underestimation of spontaneous clearance and mortality. Our results suggest that the WHO elimination targets have been met 10 years earlier than previously foreseen. These advancements were made possible by Switzerland's outstanding role in harm-reduction programmes, the longstanding micro-elimination efforts concerning HIV-infected MSM and nosocomial transmissions, little immigration from high-prevalence countries except Italian-born persons born before 1953, and wealth of data and funding.

Intermuscular extremity myxoid liposarcoma can be managed by marginal resection following neoadjuvant radiotherapy.

BACKGROUND: Compared with other soft tissue sarcomas, myxoid liposarcoma (MLS) occurs in younger patients, has a propensity for intermuscular locations and is highly radiosensitive. With pre-operative radiotherapy, intermuscular MLS demonstrates substantial volume reduction and can be easily separated from surrounding tissues during resection. However, it is unclear whether marginal excision of MLS is oncologically safe. This study aimed to assess the association between margins and survival in irradiated, intermuscular MLS. METHODS: The study identified 198 patients from seven sarcoma centres with a first presentation of localized, extremity, intermuscular MLS that received pre-operative radiotherapy and was diagnosed between 1990 and 2017. Patient and treatment characteristics, radiological and histological responses to neoadjuvant treatment and clinical surveillance were recorded. RESULTS: Margins were microscopically positive in 11% (n = 22), <1.0 mm in 15% (n = 29) and ≥1.0 mm in 72% (n = 143). There was no association between margin status and local recurrence-free, metastasis-free or overall survival. This finding held true even in patients at higher risk of worse overall survival based on multivariable analysis (% round cell≥5%, percentage ellipsoid tumour volume change ≤ -60.1%). CONCLUSION: Irradiated, extremity, intermuscular myxoid liposarcoma can safely undergo marginal resection without compromising oncologic control.

Bilateral Pseudoarthrodesis: A Case Report of Complex Bilateral Total Knee Replacement for a Severe Hemophilia A Patient with Inhibitors.

CASE: We present a severe hemophilia A patient with high titers of inhibitors presenting stage IV knee arthropathy with functional bilateral arthrodesis. On presentation, his mode of ambulation was to project himself forward without the benefit of any significant ankle motion. Total knee arthroplasty was performed on both knees and allowed significant improvement in the range of motion of both knees from 5° to 100°. CONCLUSION: Although hemophilic patients with inhibitors can represent complex cases, successful outcomes can be achieved in a multidisciplinary team setting. However, we would recommend performing this type of surgery at an earlier stage when less extensive muscle and tendon release is required.

Willingness of patients with sarcoma to participate in cancer surveillance research: a cross-sectional patient survey.

OBJECTIVES: To determine the proportion of patients with extremity sarcoma who would be willing to participate in a clinical trial in which they would be randomised to one of four different postoperative sarcoma surveillance regimens. Additionally, we assessed patients' perspectives on the burden of cancer care, factors that influence comfort with randomisation and the importance of cancer research. DESIGN: Prospective, cross-sectional patient survey. SETTING: Outpatient sarcoma clinics in Canada, the USA and Spain between May 2017 and April 2020. Survey data were entered into a study-specific database. PARTICIPANTS: Patients with extremity sarcoma who had completed definitive treatment from seven clinics across Canada, the USA and Spain. MAIN OUTCOME MEASURES: The proportion of patients with extremity sarcoma who would be willing to participate in a randomised controlled trial (RCT) that evaluates varying postoperative cancer surveillance regimens. RESULTS: One hundred thirty complete surveys were obtained. Respondents reported a wide range of burdens related to clinical care and surveillance. The majority of patients (85.5%) responded that they would agree to participate in a cancer surveillance RCT if eligible. The most common reason to participate was that they wanted to help future patients. Those that would decline to participate most commonly reported that participating in research would be too much of a burden for them at a time when they are already feeling overwhelmed. However, most patients agreed that cancer research will help doctors better understand and treat cancer. CONCLUSIONS: These results demonstrate that most participants would be willing to participate in an RCT that evaluates varying postoperative cancer surveillance regimens. Participants' motivation for trial participation included altruistic reasons to help future patients and deterrents to trial participation included the overwhelming burden of a cancer diagnosis. These results will help inform the development of patient-centred RCT protocols in sarcoma surveillance research. LEVEL OF EVIDENCE: V.

Extended intralesional curettage preferred over resection-arthrodesis for giant cell tumour of the distal radius.

BACKGROUND: Distal radius giant cell tumour (GCT) is known to be associated with distinct management difficulties, including high rates of local recurrence and lung metastases compared to other anatomic locations. Multiple treatment options exist, each with different outcomes and complications. QUESTIONS/PURPOSES: To compare oncological and functional outcomes and complications following treatment of patients with distal radius GCT by extended intralesional curettage (EIC) or resection-arthrodesis. METHODS: Patients operated on for distal radius GCT were identified from prospectively collected databases at four Canadian musculoskeletal oncology specialty centres. There were 57 patients with a mean age of 35.4 years (range 17-57). Thirteen tumours were Campanacci grade 2, and 40 were Grade 3 (4 unknown). Twenty patients presented with an associated pathologic fracture. There were 34 patients treated by EIC and 23 by en bloc resection and wrist arthrodesis. All resections were performed for grade 3 tumours. The mean follow-up was 86 months (range 1-280). RESULTS: There were a total of 11 (19%) local recurrences: 10 of 34 (29%) in the EIC group compared to only 1 of 23 (4%) in the resection-arthrodesis group (p = 0.028). For the 10 patients with local recurrence following initial treatment by EIC, 7 underwent repeat EIC, while 3 required resection-arthrodesis. The one local recurrence following initial resection was managed with repeat resection-arthrodesis. Six of the 11 local recurrences followed treatment of Campanacci grade 3 tumours, while 4 were in grade 2 lesions and in one case of recurrence the grade was unknown. There were no post-operative complications after EIC, whereas 7 patients (30%) had post-operative complications following resection-arthrodesis including 4 infections, one malunion, one non-union and one fracture (p = 0.001). The mean post-operative Musculoskeletal Tumor Society score was 33.5 in the curettage group compared to 27 in the resection group (p = 0.001). The mean Toronto Extremity Salvage Score was 98.3% following curettage compared to 91.5% after resection (p = 0.006). No patients experienced lung metastasis or death. CONCLUSIONS: EIC is an effective alternative to wide resection-arthrodesis following treatment of distal radius GCT, with the advantage of preserving the distal radius and wrist joint function, but with a higher risk of local recurrence. Most local recurrences following initial treatment by EIC could be managed with iterative curettage and joint preservation. Wide excision and arthrodesis were associated with a significantly lower risk of tumour recurrence but was technically challenging and associated with more frequent post-operative complications. EIC was associated with better functional scores. Resection should be reserved for the most severe grade 3 tumours and recurrent and complex cases not amenable to treatment with EIC and joint salvage. LEVEL OF EVIDENCE: III, retrospective comparative trial.

The Pediatric Toronto Extremity Salvage Score (pTESS): Validation of a Self-reported Functional Outcomes Tool for Children with Extremity Tumors.

BACKGROUND: The physical function of children with sarcoma after surgery has not been studied explicitly. This paucity of research is partly because of the lack of a sufficiently sensitive pediatric functional measure. The goal of this study was to establish and validate a standardized measure of physical function in pediatric patients with extremity tumors. QUESTIONS/PURPOSES: (1) What is the best format and content for new upper- and lower-extremity measures of physical function in the pediatric population? (2) Do the new measures exhibit floor and/or ceiling effects, internal consistency, and test-retest reliability? (3) Are the new measures valid? METHODS: In Phase 1, interviews with 17 consecutive children and adolescents with bone tumors were conducted to modify the format and content of draft versions of the pediatric Toronto Extremity Salvage Score (pTESS). In Phase 2, the pTESS was formally translated into French. In Phase 3, 122 participants between 7 and 17.9 years old with malignant or benign-aggressive bone tumors completed the limb-specific measure on two occasions. Older adolescents also completed the adult TESS. Floor and ceiling effects, internal consistency, test-retest reliability, and validity were evaluated. RESULTS: Feedback from interviews resulted in the removal, addition, and modification of draft items, and the pTESS-Leg and pTESS-Arm questionnaires were finalized. Both versions exhibited no floor or ceiling effects and high internal consistency (α > 0.92). The test-retest reliability was excellent for the pTESS-Leg (intraclass correlation coefficient [ICC] = 0.94; 95% CI, 0.90-0.97) and good for the pTESS-Arm (ICC = 0.86; 95% CI, 0.61-0.96). Known-group validity (ability to discriminate between groups) was demonstrated by lower mean pTESS-Leg scores for participants using gait aids or braces (mean = 68; SD = 21) than for those who did not (mean = 87; SD = 11; p < 0.001). There was no significant difference between pTESS arm scores among respondents using a brace (n = 5; mean = 73; SD = 11) and those without (n = 22; mean = 83; SD = 19; p = 0.13). To evaluate construct validity, we tested a priori hypotheses. The duration since chemotherapy correlated moderately with higher pTESS-Leg scores (r = 0.4; p < 0.001) but not with pTESS-Arm scores (r = 0.1; p = 0.80), and the duration since tumor resection correlated moderately with higher pTESS-Leg scores (r = 0.4; p < 0.001) but not pTESS-Arm scores (r = 0.2; p = 0.4). Higher VAS scores (that is, it was harder to do things) antecorrelated with both pTESS versions (pTESS-Leg: r = -0.7; p < 0.001; pTESS-Arm: r = -0.8; p < 0.001). To assess criterion validity, we compared the pTESS with the current "gold standard" (adult TESS). Among adolescents, strong correlations were observed between the TESS and pTESS-Leg (r = 0.97, p < 0.001) and pTESS-Arm (r = 0.9, p = 0.007). CONCLUSIONS: Both pTESS versions exhibited no floor or ceiling effects and had high internal consistency. The pTESS-Leg demonstrated excellent reliability and validity, and the pTESS-Arm demonstrated good reliability and reasonable validity. The pTESS is recommended for cross-sectional evaluation of self-reported physical function in pediatric patients with bone tumors. LEVEL OF EVIDENCE: Level II, outcome measurement development.

Neuroendocrine carcinoma arising in a tailgut cyst.

INTRODUCTION: A tailgut cyst, also called retrorectal cystic hamartoma, is a rare congenital lesion that forms most commonly in the retrorectal space. It is presumed to arise from remnants of early embryogenesis. PRESENTATION OF CASE: The following report describes a unique case of a retrorectal cystic hamartoma in a 53 year-old French Canadian man with a history of low back pain. The tumour underwent malignant transformation into a well-differentiated neuroendocrine carcinoma three years after the beginning of symptoms. DISCUSSION: This condition can be found at any age, but occurs especially among middle-aged women. Not only is it frequently misdiagnosed, but also several complications associated to the cyst have been reported such as infection and malignant transformation. This is why complete surgical excision of the tailgut cyst is currently recommended.

Early Improvement in Pain and Functional Outcome but Not Quality of Life After Surgery for Metastatic Long Bone Disease.

BACKGROUND: Bone metastases represent the most frequent cause of cancer-related pain, affecting health-related quality of life and creating a substantial burden on the healthcare system. Although most bony metastatic lesions can be managed nonoperatively, surgical management can help patients reduce severe pain, avoid impending fracture, and stabilize pathologic fractures. Studies have demonstrated functional improvement postoperatively as early as 6 weeks, but little data exist on the temporal progress of these improvements or on the changes in quality of life over time as a result of surgical intervention. QUESTIONS/PURPOSES: (1) Do patients' functional outcomes, pain, and quality of life improve after surgery for long bone metastases? (2) What is the temporal progress of these changes to 1 year after surgery or death? (3) What is the overall and 30-day rate of complications after surgery for long bone metastases? (4) What are the oncologic outcomes including overall survival and local disease recurrence for this patient population? METHODS: A multicenter, prospective study from three orthopaedic oncology centers in Quebec, Canada, was conducted between 2008 and 2016 to examine the improvement in function and quality of life after surgery for patients with long bone metastases. During this time, 184 patients out of a total of 210 patients evaluated during this period were enrolled; of those, 141 (77%) had complete followup at a minimum of 2 weeks (mean, 23 weeks; range, 2-52 weeks) or until death, whereas another 35 (19%) were lost to followup but were not known to have died before the minimum followup interval was achieved. Pathologic fracture was present in 34% (48 of 141) of patients. The median Mirel's score for those who underwent prophylactic surgery was 10 (interquartile range, 10-11). Surgical procedures included intramedullary nailing (55), endoprosthetic replacement (49), plate osteosynthesis (31), extended intralesional curettage (four), and allograft reconstruction (two). Seventy-seven percent (108 of 141) of patients received radiotherapy. The Musculoskeletal Tumor Society (MSTS), Toronto Extremity Salvage Score (TESS), Brief Pain Inventory (BPI) form, and Quality Of Life During Serious Illness (QOLLTI-P) form were administered pre- and postoperatively at 2 weeks, 6 weeks, 3 months, 6 months, and 1 year. Analysis of variance followed by post hoc analysis was conducted to test for significance between pre- and postoperative scores. The Kaplan-Meier estimate was used to calculate overall survivorship and local recurrence-free survival. A p value of < 0.05 was considered statistically significant. RESULTS: MSTS and BPI pain scores improved at 2 weeks when compared with preoperative scores (MSTS: 39% ± 24% pre- versus 62% ± 19% postoperative, mean difference [MD] 23, 95% confidence interval [CI], 16-32, p < 0.001; BPI: 52% ± 21% pre- versus 30% ± 21% postoperative, MD 22, 95% CI, 16-32, p < 0.001). Continuous and incremental improvement in TESS, MSTS, and BPI scores was observed temporally at 6 weeks, 3 months, 6 months, and 1 year; for example, the TESS score improved from 44% ± 24% to 73% ± 21% (MD 29, p < 0.001, 95% CI, 19-38) at 6 months. We did not detect a difference in quality of life as measured by the QOLLTI-P score (6 ± 1 pre- versus 7 ± 4 postoperative, MD 1, 95% CI, -0.4 to 3, p = 0.2). The overall and 30-day rates of systemic complications were 35% (49 of 141) and 14% (20 of 141), respectively. The Kaplan-Meier estimates for overall survival were 70% (95% CI, 62.4-78) at 6 months and 41% (95% CI, 33-49) at 1 year. Local recurrence-free survival was 17 weeks (95% CI, 11-24). CONCLUSIONS: Surgical management of metastatic long bone disease substantially improves patients' functional outcome and pain as early as 2 weeks postoperatively and should be considered for impending or pathologic fracture in patients whose survival is expected to be longer than 2 weeks provided that there are no immediate contraindications. Quality of life in this patient population did not improve, which may be a function of patient selection, concomitant chemoradiotherapy regimens, disease progression, or terminal illness, and this merits further investigation. LEVEL OF EVIDENCE: Level II, therapeutic study.

Forearm soft tissue sarcoma: tumors characteristics and oncologic outcomes following limb salvage surgery.

BACKGROUND: Complex anatomy of the forearm may impact on local control and survivals of soft tissue sarcoma. Little is known about characteristics and oncologic outcomes following surgical treatment. METHODS: Demographic and tumor data of 117 patients with forearm soft tissue sarcoma were collected and analyzed. Following limb salvage, survivals, and prognostic factors were studied. RESULTS: Seventy-three patients were males (62%) and 53 (45%) were referred after unplanned excision. Pleomorphic undifferentiated sarcoma was most frequent (45%). The average tumor size was 5.1 cm and grade III histology was mostly identified (53%). With radiotherapy, local recurrence occurs in 8 patients (7%) and 30 patients (24%) developed metastasis. Overall survival, disease free survival, local recurrence free survival, and metastasis free survival were 83%, 74%, 93%, and 74%, respectively. Better survival was found for grade I (80% vs. 60%) and small size (<5 cm) (72% vs. 47%). Large size tumor, extra-compartmental site, extramuscular, and virgin tumor were positive predictors of metastasis. CONCLUSION: Soft tissue sarcomas of the forearm are often referred after unplanned excision. Limb salvage was achieved for most and local recurrence remained low in context of radiotherapy. Metastatic progression remained frequent. Low grade and small size were predictors of survival.

Para-iliac actinomycetoma presenting as sarcoma, a late complication of appendicitis: A case report.

INTRODUCTION: Actinomycosis is known to mimic several types of neoplasms, leading to morbid surgical interventions. PRESENTATION OF CASE: We report the particular case of an extensive right para-iliac actinomycetoma presenting as a sarcoma, which to our knowledge has not yet been described in the literature, in a patient with previous ruptured appendicitis. Thanks to the collaborative work between the orthopedic and general surgeons, pathologist and microbiologist, the diagnosis of actinomycosis was made pre-operatively, saving this 15-year-old patient from a tumor resection protocol. DISCUSSION: Actinomycetomas have often been reported to present in the same way as several abdominal and gynecological neoplasms, and on rare occasions been described as mimicking other soft-tissue sarcomas, leading to unnecessary morbid tumor resection protocols. The most common cause of abdominal actinomycosis is perforated appendicitis, and may present several years later. CONCLUSION: While faced with a soft tissue mass transgressing tissue planes and possibly extending to the region of the right lower quadrant, especially with a history of previous perforated appendicitis, one should consider the possibility of an abscess caused by pathogens of intestinal origin, including the gram positive anaerobe Actinomycosis israelii. Failure to actively search for this pathogen, which is not detectable with routine staining techniques and may take up to 1-2 weeks to isolate, may lead to unnecessary morbid surgical procedures.

Diagnostic utility of molecular and cytogenetic analysis in lipoblastoma: a study of two cases and review of the literature.

AIMS: Lipoblastoma is a benign neoplasm of embryonic white fat tissue that results from the proliferation of primitive adipocytes, in which histological features can be ambiguous. In order to discriminate between lipoblastoma and other lipogenic and lipomatous tumours, we studied chromosomal alterations and protein expression in two cases of lipoblastoma in infants. METHODS AND RESULTS: Standard cytogenetic analysis, fluorescence in-situ hybridization, array comparative genomic hybridization and Western blotting allowed us to demonstrate the presence of chromosome abnormalities involving the 8q11-13 region containing the pleomorphic adenoma gene 1 (PLAG1), which are classically reported in lipoblastoma, and aberrant expression of PLAG1. CONCLUSIONS: This report illustrates two different tumorigenic pathways implicating PLAG1 in lipoblastoma: amplification through multiple copies of a small marker chromosome derived from chromosome 8, and a paracentric inversion of the long arm of chromosome 8. Both these anomalies induced aberrant expression of PLAG1, emphasizing the role of PLAG1 in tumorigenesis. The aberrant expression of PLAG1 protein has been hypothesized, but this is the first report to demonstrate its occurrence in lipoblastoma.

Effectiveness of pamidronate as treatment of symptomatic osteonecrosis occurring in children treated for acute lymphoblastic leukemia.

BACKGROUND: Osteonecrosis (ON) is a severe complication of acute lymphoblastic leukemia (ALL) treatments. Recent studies suggest that bisphosphonates might reduce pain and loss of motor function in patients with ON. We assessed the effects of pamidronate compared to standard care in patients with symptomatic ON (sON) and studied whether steroids might be continued after diagnosis of ON in some patients. METHODS: We evaluated 17 patients with sON as complication of primary ALL treatment between 2000 and 2008. Fourteen patients were treated with pamidronate. Mobility and pain control were monitored in all patients. Affected joints were classified by magnetic resonance imaging (MRI) at ON diagnosis and after 6-72 months. RESULTS: Out of 220 patients with ALL, 17 (7.7%) patients developed sON. The median age at ALL diagnosis was 11 years (range: 2.7-16.6 years) and sON occurred a median of 13.4 months (range: 2.5-34 months) after ALL diagnosis. Affected joints were hip, knee and ankle. MRI scans showed 7 severe, 4 moderate, and 6 mild ON lesions. Fourteen patients showed improvement in pain (77% of patients) and motor function (59% of patients), even though corticoids were reintroduced in 4 patients. MRI demonstrated improvement, stability or worsening in 6, 3, and 5 cases, respectively. CONCLUSIONS: Pamidronate seems to be effective in the management of pain and motor function recovery in sON. Further studies are needed to provide evidence as to whether bisphosphonates can be recommended for the treatment or the prevention of ON in childhood ALL patients.

Prophylactic antibiotic regimens in tumour surgery (PARITY): protocol for a multicentre randomised controlled study.

INTRODUCTION: Limb salvage with endoprosthetic reconstruction is the standard of care for the management of lower-extremity bone tumours in skeletally mature patients. The risk of deep postoperative infection in these procedures is high and the outcomes can be devastating. The most effective prophylactic antibiotic regimen remains unknown, and current clinical practice is highly varied. This trial will evaluate the effect of varying postoperative prophylactic antibiotic regimens on the incidence of deep infection following surgical excision and endoprosthetic reconstruction of lower-extremity bone tumours. METHODS AND ANALYSIS: This is a multicentre, blinded, randomised controlled trial, using a parallel two-arm design. 920 patients 15 years of age or older from 12 tertiary care centres across Canada and the USA who are undergoing surgical excision and endoprosthetic reconstruction of a primary bone tumour will receive either short (24 h) or long (5 days) duration postoperative antibiotics. Exclusion criteria include prior surgery or infection within the planned operative field, known colonisation with methicillin-resistant Staphylococcus aureus or vancomycin-resistant Enterococcus at enrolment, or allergy to the study antibiotics. The primary outcome will be rates of deep postoperative infections in each arm. Secondary outcomes will include type and frequency of antibiotic-related adverse events, patient functional outcomes and quality-of-life scores, reoperation and mortality. Randomisation will be blocked, with block sizes known only to the methods centre responsible for randomisation, and stratified by location of tumour and study centre. Patients, care givers and a Central Adjudication Committee will be blinded to treatment allocation. The analysis to compare groups will be performed using Cox regression and log-rank tests to compare survival functions at α=0.05. ETHICS AND DISSEMINATION: This study has ethics approval from the McMaster University/Hamilton Health Sciences Research Ethics Board (REB# 12-009). Successful completion will significantly impact on clinical practice and enhance patients' lives. More broadly, this trial will develop a network of collaboration from which further high-quality trials in Orthopaedic Oncology will follow.

Malignant perineurioma (malignant peripheral nerve sheath tumor with perineural differentiation).

The great majority of malignant peripheral nerve sheath tumors (MPNST) exhibit Schwannian differentiation. In recent years, a subset of perineurial MPNST (malignant perineurioma) has been identified based on their histologic, immunohistochemical and ultrastructural features. Immunopositivity for epithelial membrane antigen (EMA), glut-1 and claudin-1, is characteristic. Such tumors must be distinguished from benign perineurioma and a variety of atypical or malignant soft tissue tumors featuring EMA positivity. Herein, we report a perineurial MPNST involving the buttock of a 42-year-old woman. Nerve involvement was noted. The clinicopathologic features of reported examples are ummarized and key differential diagnoses are discussed.

Myxoid\round cell liposarcoma (MRCLS) revisited: an analysis of 418 primarily managed cases.

BACKGROUND: Objectives of this study were to evaluate oncologic outcomes and to provide guidelines for the management of primary myxoid (MLS) and round cell liposarcoma (RCLS). METHODS: A multicenter, retrospective study of 418 cases of MRCLS primarily managed by Canadian multidisciplinary sarcoma teams. RESULTS: Study included 418 cases (MLS: 311 patients and RCLS: 107; >5% round cell) with a median age of 45 years and a median follow-up of 5.2 years. Median tumor size was 10 cm, and 81% were deep and 90% were in lower limb. The majority of patients underwent surgical resection and radiotherapy, with a small percentage (6%) receiving chemotherapy. The overall 10-year local control rate was 93% with no differences between MLS and RCLS. Radiotherapy was significant in preventing local relapse and reducing tumor diameter (median=18%) and improving microscopic margin status, but did not impact survival. Radiotherapy and the margin status were independent predictors of local recurrence. The 5- and 10-year metastatic-free survivals were 84 and 77% respectively for MLS and 69 and 46% for RCLS. The initial site of metastasis was found in multiple locations (34%) and bone involvement was frequent (40%) with predilection for spine (79%). Round cell percent (>5%) and tumor diameter (>10 cm) correlated with increased risk for metastasis and death. CONCLUSIONS: MLS and RCLS showed different metastatic risk but equally good local control. Radiotherapy was effective in preventing local recurrence and should be delivered as neoadjuvant. New staging strategies are to be defined to account for the unusual metastatic pattern.

Adverse effect of older age on the recurrence of soft tissue sarcoma of the extremities and trunk.

PURPOSE: To examine the effect of age on the recurrence of soft tissue sarcoma in the extremities and trunk. PATIENTS AND METHODS: This was a multicenter study that included 2,385 patients with median age at surgery of 57 years. The end points considered were local recurrence and metastasis. Cox proportional hazards models were used to estimate hazard ratios across the age ranges with and without adjustment for known confounding factors. RESULTS: Older patients presented with tumors that were larger (P < .001) and of higher grade (P < .001). The proportion of positive margins increased significantly as patients age (P < .001), but radiation therapy was relatively underused in patients older than age 60 years. The 5-year cumulative incidences of local recurrence were 7.2% (95% CI, 4% to 11.7%) for patients age 30 years or younger and 12.9% (95% CI, 9.1% to 17.5%) for patients age 75 years or older. The corresponding 5-year cumulative incidences of metastasis were 17.5% (95% CI, 12.1% to 23.7%) and 33.9% (95% CI, 28.1% to 39.8%) for the same groups. Regression models showed that age was significantly associated with local recurrence (P < .001) and metastasis (P < .001) in nonadjusted models. After adjusting for imbalance in presentation and treatment variables, age remained significantly associated with local recurrence (P = .031) and metastasis (P = .019). CONCLUSION: Older patients have worse outcomes because they tend to present with worse tumors and are treated less aggressively. However, there remained a significant increase in the risk of both local and systemic recurrence associated with increasing age that could not be explained by tumor or treatment characteristics.