Diversity in Leadership at Musculoskeletal Oncology Fellowships in the United States.

Musculoskeletal oncology fellowship directors (MOFDs) possess the unique ability to influence treatment paradigms in musculoskeletal oncology through teaching and research. Currently, the characteristics that define this important role including demographics, training characteristics, research activity, and grant funding are poorly defined. A list of musculoskeletal oncology fellowship programs was obtained from the American Association of Hip and Knee Surgeons and Musculoskeletal Oncology Fellowship Match. Bibliometric data including the h-index were abstracted from Scopus. Demographics, training, and federal grant characteristics were collected from academic websites. Comparisons were made using t-tests and data were presented as means ± SD. The average age at the appointment was 41±9 years and most were male (80%) and Caucasian (85%). Few had an additional graduate degree (10% MS, 5% PhD). The mean h-index was 23±15 resulting from 91±56 publications. There was a positive correlation between age and h-index (r=0.398, p=0.082). Four MOFDs (20%) had at least one National Institutes of Health research grant. Sex, race, additional graduate degree, and procurement of NIH funding were not associated with higher h-index values. Full professors had higher h-index values than assistant/associate professors (p=0.014). Women and racial minorities are underrepresented among leadership positions in musculoskeletal oncology fellowship programs. This study can help provide a benchmark for departments in orthopedic surgery and aspiring orthopedic surgeons for MOFD positions.

Isoform- and ligand-specific modulation of the adhesion GPCR ADGRL3/Latrophilin3 by a synthetic binder.

Adhesion G protein-coupled receptors (aGPCRs) are cell-surface proteins with large extracellular regions that bind to multiple ligands to regulate key biological functions including neurodevelopment and organogenesis. Modulating a single function of a specific aGPCR isoform while affecting no other function and no other receptor is not trivial. Here, we engineered an antibody, termed LK30, that binds to the extracellular region of the aGPCR ADGRL3, and specifically acts as an agonist for ADGRL3 but not for its isoform, ADGRL1. The LK30/ADGRL3 complex structure revealed that the LK30 binding site on ADGRL3 overlaps with the binding site for an ADGRL3 ligand - teneurin. In cellular-adhesion assays, LK30 specifically broke the trans-cellular interaction of ADGRL3 with teneurin, but not with another ADGRL3 ligand - FLRT3. Our work provides proof of concept for the modulation of isoform- and ligand-specific aGPCR functions using unique tools, and thus establishes a foundation for the development of fine-tuned aGPCR-targeted therapeutics.

Can low-grade chondrosarcoma in flat bones be treated with intralesional curettage and cryotherapy?

BACKGROUND AND OBJECTIVES: Chondrosarcomas in flat bones are thought to be more aggressive in their behavior, and little is known about intralesional treatment outcomes of low-grade chondrosarcoma in these locations. We tried to find the differences between patients who had low-grade chondrosarcoma in their flat bones versus those with long bone involvement with regard to (1) disease outcome, (2) functional outcome, and (3) treatment complications. METHODS: We retrospectively reviewed 44 patients with primary low-grade chondrosarcoma who were treated with intralesional curettage and cryotherapy. The patients were divided by location of tumor, group I (flat bones, seven patients) and group II (long bones, 37 patients). RESULTS: The local recurrence rate was higher in group I with 5 years disease-free survival of 80.0% in group I and 97.0% in group II (p = 0.001). All recurrent cases were noted to have initially presented with soft tissue extension (Enneking stage IB). The mean Musculoskeletal Tumor Society score at the last follow-up was 21.7 in group I and 27.9 in group II (p = 0.045). CONCLUSIONS: Intralesional curettage and cryotherapy for low-grade chondrosarcoma appear to be a safe and reasonable surgical option for patients with lesions confined to bone (Enneking stage IA). LEVEL OF EVIDENCE: Level III, retrospective cohort study. See the Guidelines for Authors for a complete description of levels of evidence.

Radiolucent Implants for Fixation of Impending and Pathologic Fractures.

Radiolucent implants offer theoretical advantages of increased ability to evaluate the fracture site for healing and recurrence and potentially less effect on radiation treatment, avoiding scatter. Their clinical utility and outcomes have yet to be proven in a well-designed randomized trial or large cohort study, although studies based on other indications have shown relative safety and they are approved by the US Food and Drug Administration for treatment of pathologic fractures. Further research is necessary to better understand when and how these implants should be implemented in practice. [Orthopedics. 2022;45(3):e115-e121.].

Fibro-Osseous Pseudotumor Arising From Nail Bed of the Great Toe: A Rare Case of Recurrence.

A fibro-osseous pseudotumor (FOPT) is a rare, rapidly enlarging, benign soft-tissue neoplasm that presents with localized pain, swelling, and redness. It typically presents in the hands and much less frequently in the feet. FOPT is characterized histologically by foci of osseous differentiation within the proliferated fibroblasts. This must be differentiated from other benign and malignant lesions. FOPT of the toes has been described in a few reports, but recurrence, following surgical excision, is extremely rare. Here we report a young, healthy female patient who presented with a rapidly growing FOPT of the left great toe. This unusual case had recurred twice following surgical excision, all within a 2-month period of time. The lesion was again completely excised, with no recurrences at follow-ups of 18 and 36 months. In conclusion, FOPT is a rare soft tissue lesion of the toes. It features fibroblastic proliferation and osseous differentiation, which needs to be differentiated from other benign and malignant tumors. The standard treatment is complete surgical excision with an excellent prognosis.

Early Experience in Pathologic Humerus Fracture Treated With the Photodynamic Bone Stabilization System Shows Limitations Related to Patient Selection.

Impending and complete pathologic fractures often necessitate surgical fixation. Traditional orthopedic implants are commonly used, achieving clinically acceptable outcomes, but their metallic composition can impair radiographic evaluation and affect radiation treatments. Recognition of these concerns led to the development of radiolucent implants such as the minimally invasive Photodynamic Bone Stabilization System (PBSS; IlluminOss Medical Inc), featuring a light cured polymer contained within an inflatable balloon catheter. Two participating hospitals in one health care system reviewed cases using the PBSS implant. Twenty-five patients with 29 impending or pathologic fractures in the proximal radius or humerus from metastatic carcinoma, myeloma, lymphoma, and melanoma were identified. Clinical charts and imaging were reviewed to determine the status of the implant at final follow-up as well as complications. For analysis, a chi-square test was used for nominal variables and a t test was used for continuous variables. Eleven of the 25 patients were alive with disease at the time of analysis. Eight of 29 (27.5%) implants failed. Five of 25 (20%) patients required repeat surgery due to complications, including 3 revision open reduction and internal fixations, 1 open reduction and internal fixation for a periprosthetic fracture, and 1 screw removal. Five of the 9 cases (56%) (P=.03) with lesions in the distal humeral shaft had breakage of the implant by final follow-up, compared with 3 of 20 cases (15%) (P=.03) elsewhere in the humerus; no failures were seen in the radius. One of 4 patients (25%) also had failure in the surgical neck, although this did not reach significance. Five patients were noted to have progression of disease on follow-up radiographs, with 4 failures in patients with progression. The PBSS implants potentially allow improved surveillance of fracture healing and tumor recurrence along with decreased scattering of radiation during treatment. Unfortunately, there may be a higher rate of mechanical failures, particularly for lesions involving the distal humerus. This may be due to decreased cross-sectional area of the implant in this region as compared with the metaphyseal and proximal regions. Caution should be exercised when treating distal humeral pathologic fractures with large lytic lesions where the underlying disease process is not well controlled. [Orthopedics. 2021;44(3):154-159.].

Acute Onset of Vancomycin Anaphylaxis With Disseminated Intravascular Coagulation in an Orthopedic Patient Despite Prior Repeated Exposure.

Vancomycin is a glycopeptide antibiotic that exhibits bactericidal activity against gram-positive cocci. It is commonly recommended for surgical prophylaxis in cases of suspected bacterial resistance or penicillin allergy. There are 2 main types of hypersensitivity reactions associated with vancomycin. Red man syndrome is an anaphylactoid reaction caused by direct release of histamine. The second is an anaphylactic reaction, which is an immunoglobulin E-mediated response. We present the case of a 55-year-old woman with a history of metastatic giant cell tumor of the right proximal tibia. She had undergone multiple surgeries for this and other nonorthopedic conditions. The patient received vancomycin for the majority of these procedures and extended courses of vancomycin on 2 separate occasions. In the present case, the patient was taken to the operating room for a prosthetic infection, and vancomycin was given after cultures were taken. The patient immediately developed signs consistent with anaphylaxis and disseminated intravascular coagulation. This was treated acutely with hemodynamic resuscitation, replacement of blood components, steroids, and repeated boluses of epinephrine. She recovered and was taken back to the operating room during that same admission without incident. The patient has since been treated with systemic daptomycin and a tobramycin cement spacer without further incident.

Is distal locking necessary? A biomechanical investigation of intramedullary nailing constructs for intertrochanteric fractures.

OBJECTIVES: Unstable intertrochanteric fractures in the elderly occur frequently. Several studies have evaluated the biomechanical impact of distally locking long cephalomedullary nails under axial loading; however, the impact of torsional loading has not been investigated. The purpose of this study is to determine the rotational load to failure of unstable intertrochanteric fractures treated with long cephalomedullary nails, with and without distal interlocking. METHODS: Eleven paired cadaveric femora treated with long cephalomedullary nails were randomized into 2 groups. Group 1 was left unlocked, whereas group 2 was distally locked. Osteotomies were completed to create unstable 4-part fractures. The femora were anatomically fixed proximally and distally and secured to the biomechanical testing machine to undergo internal rotation. Torque and rotational angle were measured until failure. RESULTS: The locked group had a mean maximal torsional load of 57.9 ± 19.0 N·m and a mean rotational stiffness of 119.4 ± 35.7 N·m/rad. The femora treated with unlocked nails had a mean maximal torsional load of 29.1 ± 12.2 N·m and a mean rotational stiffness of 77.2 ± 31.3 N·m/rad. Distal locking resulted in a significant increase in maximal rotational load (P = 0.001) and rotational stiffness (P = 0.004) before failure. No significant difference was found in mean rotational angle at failure between groups (26.0 ± 9.6 degrees, P = 0.263). CONCLUSIONS: Maximal torsional load to failure for the unlocked group is within the functional range of rotational loads experienced at the hip for an average adult. The results show that distal locking significantly increases rotational load to failure. The authors highly recommend routine use of distal interlocking screws during cephalomedullary nail placement in unstable intertrochanteric fractures.