The surgical management of metastatic lesions of the femur

ABSTRACT BACKGROUND: Malignant tumours commonly metastasise to bone. When this occurs in the femur, surgical intervention is required to reduce pain and restore mobility post fracture, or as a prophylactic measure when fracture is anticipated. This is typically in the form of replacement with hemi- or total arthroplasty or stabilisation with an intramedullary device. The indications for one modality over the other are debatable and the reported outcomes and complications are varied. The purpose of this study is to assess the management algorithm for bony metastasis of the femur at a tertiary bone tumour unit, and the outcomes of the surgical strategies employed METHODS: A retrospective cohort study was performed of all patients presenting to our institution with femoral metastasis, both with and without pathological fracture, who were managed surgically from April 2016 to February 2020. Fractures of the femoral neck were managed with cemented arthroplasty. All other fractures were managed with intramedullary nailing, as were all lesions requiring prophylactic stabilisation. Data was recorded regarding demographics, primary pathology, location of lesion, type of surgery, and implant used. The incidence of complications including radiological failure of fixation, infection, thromboembolic phenomena, re-operation and mortality were recorded RESULTS: Eighty-five femurs in 77 patients were included (mean age 61 years, range 20-90). Lesions were located in the femoral neck (19/85, 22%), intertrochanteric (20/85, 24%), subtrochanteric (40/85, 47%), diaphyseal (2/85, 2%) and metaphyseal/per-condylar (4/85, 5%) regions of the femur. A total of 64/85 (753%) procedures were performed for fractures and 21/85 (25%) prophylactically. Eighteen of the 85 (21%) underwent long-stemmed cemented bipolar hemiarthroplasty, 1/85 (1%) long-stemmed cemented total hip replacement (THR), 62/85 (73%) cephalomedullary nailing, and 4/85 (5%) retrograde femoral intramedullary nailing. Mean follow-up was eight months (range 1-36). There were no dislocations or periprosthetic fractures in the arthroplasty group. One failure (1/66, 2%) of fixation occurred in the intramedullary nailing group. Six deaths occurred in the arthroplasty group (6/64, 9%) and 24 in the nailing group (24/66, 36%) during the study period. Four patients suffered from thromboembolic phenomena (4/77, 5%). Of the 13 patients who sustained a pathological fracture and were managed with intramedullary nailing and followed up for at least one year, all had achieved clinical and radiological union CONCLUSION: Femoral metastasis can be appropriately managed with intramedullary nailing, both prophylac-tically and in the event of fracture, with a low rate of implant failure and an expectation that healing will occur once stabilised. Intracapsular fractures can be managed with long-stemmed cemented arthroplasty with a low risk of subsequent fracture or dislocation Level of evidence: Level 4 Keywords: bone metastasis, femur, pathological fracture

Surgery for femoral metastases

Aims The aim of this study is to evaluate the clinical results of operative intervention for femoral metastases which were selected based on expected survival and to discuss appropriate surgical strategies. Methods From 2002 to 2017, 148 consecutive patients undergoing surgery for femoral metastasis were included in this study. Prognostic risk assessments were performed according to the Katagiri and revised Katagiri scoring system. In general, the low-risk group underwent resection and reconstruction with endoprosthetic replacement (EPR), while the high-risk group underwent internal fixation (IF) and radiation therapy. For the intermediate-risk group, the operative choice depended on the patient’s condition, degree of bone destruction, and radio-sensitivity. Overall survival, local failure, walking ability, and systemic complications were evaluated. Results A total of 83 patients underwent EPR (low-risk, 23%; intermediate-risk, 60%; high-risk, 17%) and 65 patients underwent IF (low-risk, 0%; intermediate-risk, 32%; high-risk, 68%). The one-year survival rate was 71% for EPR and 15% for IF (p < 0.001). The one-year local failure-free survival was 93% for EPR and 67% for IF, and the two-year and five-year local failure-free survival for EPR were both 88% (p = 0.016). Although the ambulatory rate was 99% for EPR and 60% for IF, the median time to ambulation was shorter in the IF (EPR, 28 days, interquartile range (IQR) 25 to 35; IF, 23 days, IQR 18 to 28; p < 0.001) The cause of non ambulation was mainly due to progression of cancer (89%). The rate of systemic complications was comparable between the two groups (EPR, 18%; IF, 22%; p = 0.598). Conclusion Selective use of EPR where survival is expected to be good offers correspondingly good long-term results. IF is less invasive with shorter treatment period, which is beneficial for patients with short-term expected survival. Prognosis is an important indicator in selecting operative procedures for femoral metastasis. Cite this article: Bone Joint J 2020;102-B(3):285–292

The Metastatic Early Prognostic (MEP) score

Aims The early mortality in patients with hip fractures from bony metastases is unknown. The objectives of this study were to quantify 30- and 90-day mortality in patients with proximal femoral metastases, and to create a mortality prediction tool based on biomarkers associated with early death. Methods This was a retrospective cohort study of consecutive patients referred to the orthopaedic department at a UK trauma centre with a proximal femoral metastasis (PFM) over a seven-year period (2010 to 2016). The study group were compared to a matched control group of non-metastatic hip fractures. Minimum follow-up was one year. Results There was a 90-day mortality of 46% in patients with metastatic hip fractures versus 12% in controls (89/195 and 24/192, respectively; p < 0.001). Mean time to surgery was longer in symptomatic metastases versus complete fractures (9.5 days (SD 19.8) and 3.4 days (SD 11.4), respectively; p < 0.05). Albumin, urea, and corrected calcium were all independent predictors of early mortality and were used to generate a simple tool for predicting 90-day mortality, titled the Metastatic Early Prognostic (MEP) score. An MEP score of 0 was associated with the lowest risk of death at 30 days (14%, 3/21), 90 days (19%, 4/21), and one year (62%, 13/21). MEP scores of 3/4 were associated with the highest risk of death at 30 days (56%, 5/9), 90 days (100%, 9/9), and one year (100%, 9/9). Neither age nor primary cancer diagnosis was an independent predictor of mortality at 30 and 90 days. Conclusion This score could be used to predict early mortality and guide perioperative counselling. The delay to surgery identifies a potential window to intervene and correct these abnormalities with the aim of improving survival. Cite this article: Bone Joint J. 2020;102-B(1):72–81

Fracture after radiation therapy for femoral metastasis: incidence, timing and clinical features

ABSTRACT We analyzed 428 femoral metastases initially treated with radiotherapy between 2002 and 2011 to clarify the clinical details of post-irradiation fractures of femoral metastasis. Patients included 161 men and 167 women, with a mean age of 62 years. Fracture incidence, fracture site, fracture risk based on X-ray images before radiotherapy, and interval from completion of radiotherapy to fracture occurrence were assessed. In addition, 24 pathological specimens obtained during 27 surgeries for these fractures were examined. Fractures occurred in 7.7% of 428 femoral metastases (total 33: 28 actual fractures and five virtual fractures with progressive pain and bone destruction). The fracture rate was 7.8% in the proximal femur and 1.5% in the shaft (P = 0.001). Fractures occurred a median of 4.4 months after radiotherapy, with 39.4% occurring within 3 months and 63.6% within 6 months. Among femurs with high fracture risk according to Harrington’s criteria or Mirels’ score, the fracture rate was 13.9% and 11.8%, respectively. Viable tumor cells were detected in all five patients with painful virtual fracture, in 85.7% of femurs with actual fractures that occurred within 3 months, and in only 25.0% of actual fractures occurring after 3 months. Post-irradiation fractures of femoral metastasis most frequently occurred within 3 months after radiotherapy, and were more common in the peritrochanteric area than in the shaft. Radiological evidence of impending fracture did not correlate with a high fracture rate. Actual fractures occurring after more than 3 months were likely caused by post-irradiation fragility of the femur, without viable tumor cells.

CT-Guided Percutaneous Femoroplasty for the Treatment of Proximal Femoral Metastases

Background: The spine, pelvis, skull, and femur are the most common sites of bone metastases, and pain is the main symptom of metastatic tumors. Percutaneous femoroplasty (PFP) is becoming increasingly popular for treating proximal femoral metastases. Objectives: To assess the clinical value and feasibility of PFP performed under the guidance of computed tomography (CT). Study Design: A retrospective clinical review comparing pain intensity and the ability to perform activities of daily living before and after treatment with PFP. Setting: Single academic medical center. Methods: Sixteen patients with proximal femoral metastasis were treated with PFP under CT guidance and followed up for 6 – 12 months. Pain intensity was evaluated using the visual analog scale (VAS) and patients’ quality of life was evaluated using the Barthel Index of Activities of Daily Living (BIADL) preoperatively and at both 7 days and 6 months after PFP. Results: The mean VAS score decreased from 7.44 ± 0.81 preoperatively to 2.69 ± 0.79 at 7 days postoperatively and 1.25 ± 0.93 at 6 months postoperatively. The BIADL score increased from 44.06 ± 9.53 preoperatively to 69.06 ± 8.61 at 7 days postoperatively and 83.13 ± 6.55 at 6 months postoperatively. No patients suffered from pulmonary embolism or complications such as pathologic fracture of the proximal femur. The median overall survival was 12 months. One patient experienced cement leakage into the hip, and the injection was immediately stopped. Then dexamethasone was injected intravenously to prevent potential pulmonary fat embolism caused by localized high pressure. Limitations: The study evaluated a single group of patients before and after CT-guided PFP and did not include a comparison with conventional fluoroscopic approaches in a large patient sample. Conclusion: Use of CT-guided PFP was associated with a low risk of complications and improvement in patients’ quality of life. CT guidance made the operation easy and safe, and thus, this approach represents a potential treatment option for proximal femoral metastases if indications are observed closely. Key words: CT guidance, percutaneous femoroplasty, proximal femoral metastasis, pain relief, cementoplasty