Botryomycosis: a rare mimic of sarcoma as an initial presentation of acquired immunodeficiency syndrome.

Botryomycosis is a rare granulomatous response to chronic bacterial infection most frequently associated with Staphylococcus aureus. This disease, which predominantly affects immunocompromised patients, may present with cutaneous, visceral, or soft tissue manifestations. Soft tissue involvement typically has an aggressive mass-like appearance on imaging which can be concerning for malignancy. In immunocompromised patients, botryomycosis can resemble fungal infection both clinically and histologically; therefore, definitive diagnosis requires tissue sampling along with histological and microbiological analysis. Presented here is a 25-year-old man with an enlarging intramuscular soft tissue mass of the right forearm as his first presentation of undiagnosed acquired immunodeficiency syndrome (AIDS). MR imaging showed a mildly T2 hyperintense and enhancing mass with infiltrative margins extending through tissue planes. Biopsy of the mass revealed Staphylococcus aureus-associated botryomycosis, which improved with nonsurgical treatment employing antibiotics. Unfortunately, the patient subsequently expired from other manifestations of his new AIDS diagnosis. This case describes the MR and PET-CT appearance of botryomycosis and also underscores that infection can mimic sarcoma, particularly in the setting of immunodeficiency.

Surgical Site Infection Is Not Associated with 1-Year Progression-Free Survival After Endoprosthetic Reconstruction for Lower-Extremity Osteosarcoma: A Secondary Analysis of PARITY Study Data.

BACKGROUND: Although there is evidence suggesting that postoperative infection confers a survival benefit in osteosarcoma treated with resection and endoprosthetic reconstruction, there have been no prospective studies to date to support these findings. This secondary analysis of Prophylactic Antibiotic Regimens in Tumor Surgery (PARITY) study data examines the relationship between surgical site infection (SSI) and disease progression within 12 months after limb salvage surgery. METHODS: The PARITY trial was an international, multicenter, prospective randomized controlled trial of 604 patients who underwent resection of a lower-extremity bone tumor and endoprosthetic reconstruction. Our primary outcome was progression-free survival (PFS) at 1 year following surgery among the patients with osteosarcoma. Subgroup analyses by disease stage at presentation and infection severity were also performed. Cox proportional hazard models were employed to examine the association between clinical and tumor characteristics, SSI, and PFS. Kaplan-Meier analysis was used to determine the effect of SSI on PFS. RESULTS: The 274 PARITY patients with osteosarcoma were included in this secondary analysis. Thirty-two (11.7%) of the patients presented with metastasis at baseline; 53 (19.3%) of the patients developed an SSI. There was no difference in 1-year PFS between patients with and without SSI. There was no decreased risk of disease progression at 1 year in patients with localized disease at baseline who developed an SSI (hazard ratio [HR] = 1.21; 95% confidence interval [CI] = 0.64 to 2.28). Infection was associated with increased disease progression at 1 year in patients with baseline metastases (HR = 4.26; 95% CI = 1.11 to 16.3). CONCLUSIONS: No positive association was detected between postoperative infection and PFS at 1 year following surgery in this secondary analysis of prospective data. However, this analysis suggests infection could be a risk factor for early disease progression in patients with baseline metastases, and future investigations may better elucidate the association between disease burden and the host immune response to advance immunotherapeutic strategies for osteosarcoma. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Survival and failure modes of the Compress® spindle and expandable distal femur endoprosthesis among pediatric patients: A multi-institutional study.

BACKGROUND: Expandable endoprostheses can be used to equalize limb length for pediatric patients requiring reconstruction following large bony oncologic resections. Outcomes of the Compress® Compliant Pre-Stress (CPS) spindle paired with an Orthopedic Salvage System expandable distal femur endoprosthesis have not been reported. METHODS: We conducted a multi-institutional retrospective study of pediatric patients with distal femoral bone sarcomas reconstructed with the above endoprostheses. Statistical analysis utilized Kaplan-Meier survival technique and competing risk analysis. RESULTS: Thirty-six patients were included from five institutions. Spindle survivorship was 86.3% (95% confidence interval [CI], 67.7-93.5) at 10 years. Two patients had a failure of osseointegration (5.7%), both within 12 months. Twenty-two (59%) patients had 70 lengthening procedures, with mean expansions of 3.2 cm (range: 1-9) over 3.4 surgeries. The expandable mechanism failed in eight patients with a cumulative incidence of 16.1% (95% CI, 5.6-31.5) at 5 years. Twenty-nine patients sustained International Society of Limb Salvage failures requiring 63 unplanned surgeries. Periprosthetic joint infection occurred in six patients (16.7%). Limb preservation rate was 91% at 10 years. CONCLUSIONS: There is a high rate of osseointegration of the Compress® spindle among pediatric patients when coupled with an expandable implant. However, there is a high rate of expansion mechanism failure and prosthetic joint infections requiring revision surgery. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Cutibacterium (formerly Propionibacterium) acnes clavicular infection.

Cutibacterium (formerly Propionibacterium) acnes13, 16 is a slow growing, gram-positive bacteria that is naturally found in higher concentrations as skin flora on the chest and back, as well as in other areas with greater numbers of hair follicles.25, 37 Most of the reported cases of C. acnes shoulder girdle infection follow arthroplasty surgery,18, 20, 26, 27, 32, 35 which then often requires debridement, administration of intravenous antibiotics, and surgical revision of the implanted device.12, 15, 21, 28-30 In a recent study, 56% of 193 shoulder revisions had a positive culture, 70% of which grew C. acnes.30 Despite the relatively common presumed association of C. acnes humeral osteomyelitis with prosthetic infection, infection of the scapula or clavicle secondary to C. acnes is rare.4, 23, 36 Osteomyelitis of the clavicle involving any organism is also an uncommon event that can arise spontaneously via presumed hematogenous spread, or secondary to open fractures or internal fixation.6, 33 The most commonly found organism in clavicular osteomyelitis is Staphylococcus aureus.9 We here report two cases of clavicular infection secondary to C. acnes that were not associated with implants.

Considerations for the Long Term Treatment of Pediatric Sarcoma Survivors.

Sarcomas are primary malignancies of the connective tissues. They are exceedingly rare in adults, but much more common in children. The historically recent advent of cytotoxic chemotherapy for pediatric sarcomas has revolutionized the treatment of these diseases and dramatically improved their prognoses. There is thus a population of pediatric sarcoma survivors that are "coming of age" as adults. However, this progress is not without consequences. Due to aggressive treatment protocols that include various combinations of surgery, chemotherapy, and radiation therapy, pediatric sarcoma survivors are at risk of myriad physical, medical, and psychological difficulties as they enter adulthood. These include but are not limited to physical disabilities, chemotherapy-induced cardiac issues, second malignancies, and anxiety. These patients pose unique challenges to their adult primary care physicians. One possible solution to these challenges is multidisciplinary sarcoma survivorship clinics. By paying greater attention to the unique issues of pediatric sarcoma survivors, involved physicians can maximize the physical and emotional health of pediatric sarcoma survivors.

HPMA-Copolymer Nanocarrier Targets Tumor-Associated Macrophages in Primary and Metastatic Breast Cancer.

Polymeric nanocarriers such as N-(2-hydroxypropyl) methacrylamide (HPMA) copolymers deliver drugs to solid tumors and avoid the systemic toxicity of conventional chemotherapy. Because HPMA copolymers can target sites of inflammation and accumulate within innate immune cells, we hypothesized that HPMA copolymers could target tumor-associated macrophages (TAM) in both primary and metastatic tumor microenvironments. We verified this hypothesis, first in preliminary experiments with isolated bone marrow macrophage cultures in vitro and subsequently in a spontaneously metastatic murine breast cancer model generated from a well-established, cytogenetically characterized 4T1 breast cancer cell line. Using our standardized experimental conditions, we detected primary orthotopic tumor growth at 7 days and metastatic tumors at 28 days after orthotopic transplantation of 4T1 cells into the mammary fat pad. We investigated the uptake of HPMA copolymer conjugated with Alexa Fluor 647 and folic acid (P-Alexa647-FA) and HPMA copolymer conjugated with IRDye 800CW (P-IRDye), following their retroorbital injection into the primary and metastatic tumor-bearing mice. A significant uptake of P-IRDye was observed at all primary and metastatic tumor sites in these mice, and the P-Alexa647-FA signal was found specifically within CD11b+ TAMs costained with pan-macrophage marker CD68. These findings demonstrate, for the first time, a novel capacity of a P-Alexa647-FA conjugate to colocalize to CD11b+CD68+ TAMs in both primary and metastatic breast tumors. This underscores the potential of this HPMA nanocarrier to deliver functional therapeutics that specifically target tumor-promoting macrophage activation and/or polarization during tumor development. Mol Cancer Ther; 16(12); 2701-10. ©2017 AACR.

Revision Distal Femoral Arthroplasty With the Compress(®) Prosthesis Has a Low Rate of Mechanical Failure at 10 Years.

BACKGROUND: Patients with failed distal femoral megaprostheses often have bone loss that limits reconstructive options and contributes to the high failure rate of revision surgery. The Compress(®) Compliant Pre-stress (CPS) implant can reconstruct the femur even when there is little remaining bone. It differs from traditional stemmed prostheses because it requires only 4 to 8 cm of residual bone for fixation. Given the poor long-term results of stemmed revision constructs, we sought to determine the failure rate and functional outcomes of the CPS implant in revision surgery. QUESTIONS/PURPOSES: (1) What is the cumulative incidence of mechanical and other types of implant failure when used to revise failed distal femoral arthroplasties placed after oncologic resection? (2) What complications are characteristic of this prosthesis? (3) What function do patients achieve after receiving this prosthesis? METHODS: We retrospectively reviewed 27 patients who experienced failure of a distal femoral prosthesis and were revised to a CPS implant from April 2000 to February 2013. Indications for use included a minimum 2.5 mm cortical thickness of the remaining proximal femur, no prior radiation, life expectancy > 10 years, and compliance with protected weightbearing for 3 months. The cumulative incidence of failure was calculated for both mechanical (loss of compression between the implant anchor plug and spindle) and other failure modes using a competing risk analysis. Failure was defined as removal of the CPS implant. Followup was a minimum of 2 years or until implant removal. Median followup for patients with successful revision arthroplasty was 90 months (range, 24-181 months). Functional outcomes were measured with the Musculoskeletal Tumor Society (MSTS) functional assessment score. RESULTS: The cumulative incidence of mechanical failure was 11% (95% confidence interval [CI], 4%-33%) at both 5 and 10 years. These failures occurred early at a median of 5 months. The cumulative incidence of other failures was 18% (95% CI, 7%-45%) at 5 and 10 years, all of which were deep infection. Three patients required secondary operations for cortical insufficiency proximal to the anchor plug in bone not spanned by the CPS implant and unrelated to the prosthesis. Median MSTS score was 27 (range, 24-30). CONCLUSIONS: Revision distal femoral replacement arthroplasty after a failed megaprosthesis is often difficult as a result of a lack of adequate bone. Reconstruction with the CPS implant has an 11% failure rate at 10 years. Our results are promising and demonstrate the durable fixation provided by the CPS implant. Further studies to compare the CPS prosthesis and other reconstruction options with respect to survival and functional outcomes are warranted. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Carbon fiber intramedullary nails reduce artifact in postoperative advanced imaging.

OBJECTIVE: This study assessed whether radiolucent carbon fiber reinforced-polyetheretherketone (CFR-PEEK) intramedullary nails decreased hardware artifact on magnetic resonance imaging (MRI) and computed tomography (CT) in vitro and in an oncologic patient population. MATERIALS AND METHODS: In vitro and clinical evaluations were done. A qualitative assessment of metal artifact was performed using CFR-PEEK and titanium nail MRI phantoms. Eight patients with a femoral or tibial prophylactic CFR-PEEK nail were retrospectively identified. All patients had postoperative surveillance imaging by MRI, CT, and were followed for a median 20 months (range, 12-28 months). CFR-PEEK images were compared to images from a comparative group of patients with titanium femoral intramedullary nails who had a postoperative MRI or CT. A musculoskeletal-trained radiologist graded visualization of the cortex, corticomedullary junction, and bone-muscle interface, on T1-weighted (T1W), STIR, and contrast-enhanced T1-weighted fat-saturated (T1W FS) sequences of both groups with a five-point scale, performing independent reviews 4 months apart. Statistical analysis used the Wilcoxon rank-sum test and a weighted kappa. RESULTS: Substantially less MRI signal loss occurred in the CFR-PEEK phantom than in the titanium phantom simulation, particularly as the angle increased with respect to direction of the static magnetic field. CFR-PEEK nails had less MRI artifact than titanium nails on scored T1W, STIR, and contrast-enhanced T1W FS MRI sequences (p ≤ 0.03). The mean weighted kappa was 0.64, showing excellent intraobserver reliability between readings. CONCLUSIONS: CFR-PEEK intramedullary nail fixation is a superior alternative to minimize implant artifact on MRI or CT imaging for patients requiring long bone fixation.

Reverse total shoulder arthroplasty for the management of failed shoulder arthroplasty with proximal humeral bone loss: is allograft augmentation necessary?

BACKGROUND: Patients undergoing revision shoulder arthroplasty frequently have deficient proximal humeral bone stock. Proximal humeral allograft has been recommended to augment reverse total shoulder arthroplasty (RTSA) to improve stability and function. This study reports the results of RTSA without proximal humeral allograft in patients with proximal humeral bone loss secondary to failed shoulder arthroplasty. MATERIALS AND METHODS: From 2005 to 2008, 251 patients were enrolled in a prospective RTSA cohort study. Significant humeral bone loss was demonstrated in 15 of 56 undergoing revision for failed arthroplasty. Average age was 67 years. Average bone loss measured 38.4 mm (range, 26-72 mm). Patients were followed up for a minimum of 2 years with American Shoulder and Elbow Surgeons (ASES), Subjective Shoulder Value (SSV), Constant Score (CS), and visual analog scale (VAS) pain scores, as well as self-reported satisfaction and radiographs. RESULTS: Patients demonstrated significant improvement in mean CS (23.0 to 44.2), ASES (38.2 to 68.3), ASES activities of daily living (7.0 to 15.9), SSV (19.2 to 75.8), and VAS pain (4.6 to 1.6) scores. Thirteen of 15 patients reported satisfaction (87%). Range of motion improved in forward flexion (38.3° to 103.2°) and external rotation (-0.5° to 11.9°). Radiographs demonstrated notching in 3 patients (20%), no humeral subsidence or loosening, and prosthetic fracture of 1 modular humeral stem. CONCLUSIONS: Use of RTSA for failed shoulder arthroplasty and deficient humeral bone stock provides a significant clinical benefit without the need for allograft augmentation. Monoblock humeral component use may diminish risk for prosthetic fracture.

Megaprosthesis versus Condyle-sparing intercalary allograft: distal femoral sarcoma.

UNLABELLED: Although functionally appealing in preserving the native knee, the condyle-sparing intercalary allograft of the distal femur may be associated with a higher risk of tumor recurrence and endoprosthetic replacement for malignant distal femoral bone tumors. We therefore compared the risk of local tumor recurrence between patients in these two types of reconstruction groups. We retrospectively reviewed 85 patients (mean age, 22 years; range, 4-82 years), 38 (45%) of whom had a condyle-sparing allograft and 47 (55%) of whom had endoprostheses. The minimum followup for both groups was 2 years (mean, 7 years; range, 2-19 years). Local recurrences occurred in 11% (five of 47) of the patients having implants versus 18% (seven of 38) of the patients having allografts. Using time to local recurrence as an end point, the Kaplan-Meier survivorship of the implant group was similar to that of the condyle-sparing allograft group at 2, 5, and 10 years (93% versus 87% at 2 years, 87% versus 81% at 5 years, and 87% versus 81% at 10 years, respectively). The condyle-sparing allograft procedure offers the potential advantage of retaining the native knee in a young patient population while incurring no greater risk of local recurrence as those offered the endoprosthetic procedure. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.