BACKGROUND: To prevent infection after limb-sparing surgery for primary malignant bone tumors, it is important to cover the megaprosthesis with muscle tissue that has sufficient blood flow. Coverage with a lateral gastrocnemius flap has been reported in cases of distal femoral replacement in which the vastus lateralis and vastus intermedius muscles have been resected; however, the risk of peroneal nerve palsy is reportedly high because the muscle flap passes near the peroneal head. This study was performed to examine the postoperative outcomes of patients with primary malignant bone tumors of the distal femur who underwent wide resection (including the vastus lateralis and vastus intermedius muscles) followed by reconstruction with a megaprosthesis and coverage of the lateral side of the prosthesis with a sartorius muscle flap.
METHODS: We retrospectively analyzed three patients who underwent reconstruction with a megaprosthesis after wide resection of a primary malignant bone tumor of the distal femur involving the vastus lateralis and vastus intermedius muscles and reconstruction of the soft tissue defect on the lateral side of the prosthesis with a sartorius muscle flap.
RESULTS: The average defect size was 6 × 13 cm, the average time required for a sartorius muscle flap was 100 min, and the average implant coverage was 93%. The average postoperative follow-up period was 35 months, during which no postoperative complications such as infection, skin necrosis, or nerve palsy occurred.
CONCLUSIONS: The distally based sartorius muscle flap is easy to elevate in the supine position, has minimal functional loss after harvesting, and has minimal risk of nerve palsy. It can be advocated as the first option for coverage of soft tissue defects lateral to distal femoral replacement.

As managing pathological fractures of the extremities can be difficult, the present study aimed to present a treatment algorithm for lower extremity bone malignancies. A total of 38 patients with impending and pathological fractures were treated at the Department of Orthopedic Surgery in Kindai University Hospital. Age, sex, fracture site, type of primary malignancy, number of metastases, pre-fracture Eastern Cooperative Oncology Group performance status (ECOG-PS) score, adjuvant therapy, treatment modality, operative time, blood loss, postoperative complications, Musculoskeletal Tumor Society (MSTS) score, outcomes, follow-up period and the MSTS scores and ECOG-PS were compared in cases of primary malignant tumors and those cases of metastatic malignant tumors were retrospectively surveyed. Post-treatment MSTS scores in cases of impending and pathological fractures were compared between intramedullary nail fixation and non-intramedullary nail fixation procedures. Disease sites included the sub-trochanteric femur in 10 patients, trochanteric femur in 8, femoral diaphysis in 7, femoral neck in 5, bilateral trochanteric femur in 3, proximal tibia in 3 and distal femur in 2 patients. A total of 10 patients had metastases between 3-20 sites. The median pre-fracture ECOG-PS score was 1. Adjuvant radiotherapy was administered to 5, chemotherapy to 8 and radiotherapy with chemotherapy to 10 patients. Surgical procedures included intramedullary nails in 18 patients, tumor arthroplasty in 4, plate fixation in 3, artificial head replacement in three, compression hip screw (CHS) in 3, conservative treatment in 2, bilateral intramedullary nail fixation in 2 and artificial bone stem with combined intramedullary nail and plate fixation, right-sided artificial head replacement and left-sided CHS in 1 patient each. The MSTS score was 19.9±8.95 for intramedullary nail fixation and 24.3±7.45 for other procedures, with a negative association between the MSTS score and pre-fracture ECOG-PS. The median follow-up period was 8 months. The outcomes were as follows: Alive with disease, 23 patients; continued disease-free, 1 patient; and dead due to disease, 14 patients. The 1-year postoperative overall survival rate was 60.5%. Moreover, the group with metastatic malignant tumors, which had significantly worse ECOG-PS, had significantly lower MSTS scores than the group with primary malignant tumors. The authors\' treatment algorithm for malignant bone tumors of the lower extremity was shown to be useful.

Intraosseous hibernoma is an uncommon presentation of brown adipose tissue benign tumors. Imaging differential diagnoses include bone island, sclerotic metastasis, lymphoma, hemangioma, and sclerotic myeloma. In this report, a 72-year-old patient presented with right hip pain following a fall injury, leading to an extensive diagnostic workup. Initial CT of the pelvis without contrast suggested potential sclerotic metastatic disease. MRI findings could not be definitive. Further assessment with CT-guided biopsy and S-100 immunohistochemical staining confirmed a rare diagnosis of intraosseous hibernoma. This case describes multimodality imaging characteristics of a rare intraosseous hibernoma with discussion of imaging features of differential diagnostic considerations of related benign and malignant bone lesions.

Compartment syndrome is a rare critical condition that can arise in individuals with cancer, presenting with significant challenges in diagnosis and management. Compartment syndrome occurs when the pressure within a closed fascial space rises to a point that restricts circulation. A 56 year-old male patient presented with 2 days of pain and swelling in the right upper extremity pain. Physical examination was remarkable for right upper extremity erythema swelling and tense compartments, concerning for compartment syndrome. Humerus X-ray showed moth eaten appearance of mid humerus with periosteal reaction and fracture. Patient was taken to the operating room for anterior and posterior compartment fasciotomies. Compartment syndrome is a surgical emergency, for which fasciotomy is generally performed. Pathology has rarely been linked to malignancy, with seldom reports examining causation. More research regarding pathophysiology of cancer in relation to compartment syndrome needs to be conducted.

UNASSIGNED: Enchondroma is a cartilaginous benign tumor of bone with the most common involvement of tubular bones of hands and feet. The triquetrum and pisiform are carpal bones and the enchondroma of the triquetrum and pisiform has not been reported in the literature to the best of our knowledge.
UNASSIGNED: A 26-year-old male presented with swelling over his right wrist with painful terminal motion. Based on magnetic resonance imaging findings, diagnosis of enchondroma of triquetrum and pisiform was made. Bone excision and curettage were performed, and histopathology confirmed the diagnosis. After 2 years of follow-up, the patient has gained pain-free wrist movements post excision, and there are no signs of recurrence. The Modified Mayo Wrist Score of 75 (fair) improved to 100 (excellent).
UNASSIGNED: The surgeon should always keep in mind the possibility of a tumor at the rare site and accurately diagnose the tumor with the help of imaging modalities and biopsy.

Determining the risk of pathologic fracture in dogs with a primary bone tumor would aid in case selection for in-situ treatment options. Prior research found strong relationships between in vitro strength of canine antebrachii with primary bone tumors and CT-derived metrics. This study assesses the prognosis for pathologic fracture in dogs with distal radial bone tumors using CT-derived structural analysis metrics. CT images of the antebrachium in dogs with aggressive osseous lesions of the radius were used to calculate structural rigidity and failure forces, including axial rigidity (AR), craniocaudal bending rigidity (BR), torsional rigidity (TR), and failure forces for a slightly-curved/asymmetric beam (Fs) or a curved beam (Fc). Metrics were compared with the clinical outcome of radial fracture. Eight of 19 dogs with CT-derived metrics developed a radial fracture. The prognostic potential of the metrics to discriminate fractured and nonfractured bones was analyzed using receiver operating characteristic curves (area under the curve), stepwise logistic regression, and classification regression (CART) analyses. Fc was the most sensitive and specific metric for prognosing fracture occurrence (AUC = 0.864). When dog body weight (BW) was included, all five metrics had AUC > 0.705. Fc was the best predictor of fracture using stepwise logistic regression and CART analysis, followed by BR. An indication of fracture probability can be determined by normalizing Fc or BR with dog BW or by using the logistic regression equation of either metric with dog BW. Results warrant further analysis of a larger cohort to evaluate fracture likelihood in dogs with antebrachial bone neoplasia.

Aim: Nano-hydroxyapatite (nHA) is a good nanocarrier to load 223Ra, but the low specific activity (sp.act.) of 223Ra@nHA limits its application in medicine. Methods: We proposed a method for preparing nHA using PEG as a template, which significantly increases the sp.act of 223Ra@nHA and a new method to loaded 99mTc for in vivo tracking. Results: The nHA synthesized using PEG as a template was associated with higher sp.act for 223Ra in comparison to nHA with identical particle size and without PEG. The nHA load 99mTc-MDP was associated with higher labeling rate and stability in comparison to 99mTc. Conclusion: All these findings suggest that using PEG as a template and 99mTc-MDP could be the most effective of synthetic 223Ra/99mTc@nHA.
[Box: see text].

BACKGROUND: Serum level of tartrate-resistant acid phosphatase 5b (TRACP5b) is an excellent serum marker of bone resorption. In patients with giant cell tumor of bone (GCTB), TRACP5b levels are reportedly elevated. This study investigated whether TRACP5b could be a diagnostic serum marker and be useful for detecting postoperative disease progression for GCTB.
METHODS: Cohort 1: We abstracted data from 120 patients with TRACP5b measurements from our database: 49 patients with GCTB and 71 patients non-GCTB. We compared serum TRACP5b values between the GCTB and non-GCTB groups. Cohort 2 included 47 patients with GCTB who had more than 6 months of follow-up and multiple TRACP5b values. For patients with local recurrence, TRACP5b change rate was calculated by comparing the TRACP5b value just before progression (a) with the value at the time of progression (b): Change rate = [(b)-(a)]/(a). In the non-progression group, the change rate was calculated from the two consecutive TRACP5b values, (c) and (d): Change rate =[(c)-(d)]/(c). We compared TRACP5b change rates between the progression and non-progression groups.
RESULTS: Cohort 1: The GCTB group had a significantly higher mean TRACP5b value (1756 ± 2021 mU/dL) than the non-GCTB group (415 ± 219 mU/dL) (p < 0.0001). Cohort 2: The mean TRACP5b change rate of the progression group was significantly higher than the non-progression group (8.53 ± 8.52 and 0.24 ± 0.27, respectively; p < 0.0001).
CONCLUSIONS: TRACP5b is a useful diagnostic marker in GCTB. The rate of change in serum TRACP5b values is a highly sensitive marker for predicting local recurrence in GCTB.

With the improvement in survival of patients undergoing knee reconstructive surgeries, the functional parameter became widely studied heading optimize and minimize motor sequelae. In patients undergoing knee endoprosthesis, proximal tibial or distal femoral resections affect the functioning of the knee extensor mechanism, with possible repercussions on gait. Seventeen patients were selected, divided into two groups, undergoing distal femoral or proximal tibial resection, and gait analysis examination was performed. Changes in gait velocity, cadence, step length, and alterations in the support and balance phase were observed. No major statistically significant differences were found in the kinetic and kinematic parameters between the operated groups. The study corroborates that although tibial resections have a higher theoretical risk of compromising the extensor mechanism, such data were not observed in the analyzed sample.

UNASSIGNED: Osteochondromas are the most common benign tumors of the bone and can be sessile or pedunculated. Although osteochondromas are typically seen in the long bones, they are rarely seen in the small bones of the hand or foot. Verruca vulgaris, also known as the common wart, is one of the most common skin conditions presenting to physicians and must be distinguished either clinically or histologically from other hyperkeratotic conditions, including bone conditions such as bone tumors that can place pressure on the skin and cause callus formation that can mimic a wart or create skin deformity. A high index of suspicion for underlying bone mass or tumor should be entertained when evaluating patients for skin conditions, particularly of the hand or foot, with failure to improve with treatment.
UNASSIGNED: This case report presents a 20-year-old male with a pedunculated osteochondroma of the left fourth distal phalanx with hyperkeratotic skin overlying the mass at the end of the toe. He was initially treated by a family doctor and podiatrist for verruca vulgaris for over 5 years with two treatments of liquid nitrogen cryotherapy and surgical excision of the mass when the treating podiatrist encountered bone and recommended radiographs. The family requested follow-up with our practice several days later after they were told the patient had a bone tumor. The patient requested surgical excision of the osteochondroma secondary to pain with activities and difficulties with his vocation as a pilot.
UNASSIGNED: All physicians must be mindful of an underlying bone tumor or mass in patients presenting with skin changes, particularly about the foot or hand. Knowledge that an underlying bone tumor can present as a verruca vulgaris may prevent a delay in diagnosis or unnecessary treatment when evaluating and treating a patient with a skin lesion. Fortunately, our case was a benign osteochondroma; a malignant tumor with a delay in diagnosis could lead to loss of limb or life.