What Factors Are Associated With Local Metastatic Lesion Progression After Intramedullary Nail Stabilization?

BACKGROUND: Pathologic fracture of the long bones is a common complication of bone metastases. Intramedullary nail stabilization can be used prophylactically (for impending fractures) or therapeutically (for completed fractures) to preserve mobility and quality of life. However, local disease progression may occur after such treatment, and there is concern that surgical instrumentation and the intramedullary nail itself may seed tumor cells along the intramedullary tract, ultimately leading to loss of structural integrity of the construct. Identifying factors associated with local disease progression after intramedullary nail stabilization would help surgeons predict which patients may benefit from alternative surgical strategies. QUESTIONS/PURPOSES: (1) Among patients who underwent intramedullary nail stabilization for impending or completed pathologic fractures of the long bones, what is the risk of local progression, including progression of the existing lesion and development of a new lesion around the nail? (2) Among patients who experience local progression, what proportion undergo reoperation? (3) What patient characteristics and treatment factors are associated with postoperative local progression? (4) What is the difference in survival rates between patients who experienced local progression and those with stable local disease? METHODS: Between January 2013 and December 2019, 177 patients at our institution were treated with an intramedullary nail for an impending or completed pathologic fracture. We excluded patients who did not have a pathologic diagnosis of metastasis before fixation, who were younger than 18 years of age, who presented with a primary soft tissue mass that eroded into bone, and who experienced nonunion from radiation osteitis or an avulsion fracture rather than from metastasis. Overall, 122 patients met the criteria for our study. Three fellowship-trained orthopaedic oncology surgeons involved in the care of these patients treated an impending or pathologic fracture with an intramedullary nail when a long bone lesion either fractured or was deemed to be of at least 35% risk of fracture within 3 months, and in patients with an anticipated duration of overall survival of at least 6 weeks (fractured) or 3 months (impending) to yield palliative benefit during their lifetime. The most common primary malignancy was multiple myeloma (25% [31 of 122]), followed by lung carcinoma (16% [20 of 122]), breast carcinoma (15% [18 of 122]), and renal cell carcinoma (12% [15 of 122]). The most commonly involved bone was the femur (68% [83 of 122]), followed by the humerus (27% [33 of 122]) and the tibia (5% [6 of 122]). A competing risk analysis was used to determine the risk of progression in our patients at 1 month, 3 months, 6 months, and 12 months after surgery. A proportion of patients who ultimately underwent reoperation due to progression was calculated. A univariate analysis was performed to determine whether lesion progression was associated with various factors, including the age and sex of the patient, use of adjuvant therapies (radiation therapy at the site of the lesion, systemic therapy, and antiresorptive therapy), histologic tumor type, location of the lesion, and fracture type (impending or complete). Patient survival was assessed with a Kaplan-Meier curve. A p value < 0.05 was considered significant. RESULTS: The cumulative incidence of local tumor progression (with death as a competing risk) at 1 month, 3 months, 6 months, and 12 months after surgery was 1.9% (95% confidence interval 0.3% to 6.1%), 2.9% (95% CI 0.8% to 7.5%), 3.9% (95% CI 1.3% to 8.9%), and 4.9% (95% CI 1.8% to 10.3%), respectively. Of 122 patients, 6% (7) had disease progression around the intramedullary nail and 0.8% (1) had new lesions at the end of the intramedullary nail. Two percent (3 of 122) of patients ultimately underwent reoperation because of local progression. The only factors associated with progression were a primary tumor of renal cell carcinoma (odds ratio 5.1 [95% CI 0.69 to 29]; p = 0.03) and patient age (difference in mean age 7.7 years [95% CI 1.2 to 14]; p = 0.02). We found no associations between local disease progression and the presence of visceral metastases, other skeletal metastases, radiation therapy, systemic therapy, use of bisphosphonate or receptor activator of nuclear factor kappa-B ligand inhibitor, type of fracture, or the direction of nail insertion. There was no difference in survivorship curves between those with disease progression and those with stable local disease (= 0.36; p = 0.54). CONCLUSION: Our analysis suggests that for this population of patients with metastatic bone disease who have a fracture or impeding fracture and an anticipated survival of at least 6 weeks (completed fracture) or 3 months (impending fracture), the risk of experiencing local progression of tumor growth and reoperations after intramedullary nail stabilization seems to be low. Lesion progression was not associated with the duration of survival, although this conclusion is limited by the small number of patients in the current study and the competing risks of survival and local progression. Based on our data, patients who present with renal cell carcinoma should be cautioned against undergoing intramedullary nailing because of the risk of postoperative lesion progression. LEVEL OF EVIDENCE: Level III, therapeutic study.

Bisphosphonate Therapy for Treating Osteonecrosis in Pediatric Leukemia Patients: A Systematic Review.

BACKGROUND: Despite improved outcomes in children with leukemia, complications such as osteonecrosis are common. We conducted a systematic review to investigate the role of bisphosphonates in reducing pain, improving mobility, and stabilizing lesions in pediatric leukemia survivors. METHODS: Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we searched the PubMed, Embase, Cochrane, Web of Science, Scopus, CINAHL, and ClinicalTrials.gov databases. Five of 221 articles retrieved met our inclusion criteria. RESULTS: Bisphosphonates, especially when combined with dietary calcium and vitamin D supplements and physical therapy (supplements/PT) were associated with improved pain and mobility in 54% and 50% of patients, respectively. A significantly greater proportion of patients treated with bisphosphonates (83%) reported mild/moderate pain or no pain compared with those with supplements/PT alone (36%) (P<0.001). Sixty-six percent of patients treated with bisphosphonates achieved improved/full mobility compared with 27% of those treated with supplements/PT alone (P=0.02). However, 46% of patients showed progressive joint destruction despite bisphosphonate therapy. No adverse events were reported, except for acute phase reactions to intravenous therapies. CONCLUSIONS: Bisphosphonates, when combined with supplements/PT, were associated with less pain and improved mobility, but not prevention of joint destruction in pediatric leukemia patients with osteonecrosis.

Adjuvant MRI-guided percutaneous cryoablation treatment for aneurysmal bone cyst.

Aneurysmal bone cysts are benign, expansile, lytic bone lesions that behave in a locally aggressive manner. Although radiography and computed tomography (CT) can detect the lesion, magnetic resonance imaging (MRI) is ideal for the demonstration of characteristic fluid-fluid levels, extent, and margins. Treatment typically consists of open surgical curettage with the addition of local adjuvants and bone grafting. Residual or recurring lesions may be treated using percutaneous cryoablation. Although CT guidance is often employed for image guidance, visualization and targeting of smaller clusters can be challenging in young children, secondary to the partially mineralized bone matrix in the immature skeleton. In such cases, the higher contrast resolution of interventional MRI affords direct visualization and targeting of small aneurysmal bone cysts, accurate monitoring of the extent of the growing ice ball beyond the lesion's margin, and avoidance of exposure to ionizing radiation. We report a case of a 5-year-old boy with recurrent or remaining aneurysmal bone cysts of the scapula after surgical excision and embolization, which were successfully treated using MRI-guided cryoablation.

Lymphatic spread of pagetic osteogenic sarcoma detected by bone scan.

Bone scans are widely utilized for detection of metastases from bone sarcomas. Technetium methylene diphosphonate scan ([(99m)Tc]MDP) is one of the most popular radiotracers used for that purpose. Lymphatic spread of bone sarcomas is unusual and often difficult to diagnose. Unfortunately, bone scans are not as sensitive in demonstrating lymphatic spread of sarcomas as they are at demonstrating hematogenous spread. A bone scan will often fail to demonstrate lymph nodes metastases until there is mineralization at the affected node. In this report, we highlight an interesting case of a patient with secondary osteogenic sarcoma (OS) from Paget's disease in the distal femur with non-ossified inguinal nodal metastasis diagnosed with [(99m)Tc]MDP. Lymph node involvement was not appreciated on plain radiographs or computed tomography (CT).

Prospective identification of risk factors for wound infection after lower extremity oncologic surgery.

BACKGROUND: Surgical site infections (SSI) are frequent causes of morbidity and mortality after orthopaedic oncologic procedures. This study was conducted to identify the surgical site infection rate following a lower extremity or pelvic procedure and assess the risk factors for acquiring SSI by direct observation of orthopaedic oncology patients' wounds at a comprehensive cancer center. METHODS: One hundred ten consecutive patients were prospectively studied. The surveillance of surgical site infections was carried out by a surgeon-trained nurse from the Infectious Disease Service. Nineteen variables were analyzed as risk factors. RESULTS: The overall SSI rate was 13.6% (15 of 110). Excluding those patients with known preoperative infections, the SSI rate was 9.5% (10 of 105). Two statistically significant risk factors for surgical site infection in these patients emerged in the multivariate analysis: blood transfusion (P =.007) and obesity (P =.016). Procedure category was significant in univariate analysis only. Preoperative length of stay, length of procedure, prior adjuvant treatment (chemotherapy or radiotherapy), prior surgery, and use of an implant or allograft were not statistically significant risk factors for wound infection. Antibiotic usage patterns did not influence SSI rate. CONCLUSIONS: Blood transfusion and obesity should be considered individual risk factors for the development of wound infection in patients having orthopaedic oncologic procedures.