Management of skeletal metastases: An orthopaedic surgeon's guide

Abstract

Skeletal metastasis is a common cause of severe morbidity, reduction in quality of life (QOL) and often early mortality. Its prevalence is rising due to a higher rate of diagnosis, better systemic treatment, longer lives with the disease and higher disease burden rate. As people with cancer live longer and with rising sensitivity of body imaging and surveillance, the incidence of pathological fracture, metastatic epidural cord compression is rising and constitutes a challenge for the orthopedic surgeon to maintain their QOL. Metastatic disease is no longer a death sentence condemning patients to "terminal care." In the era of multidisciplinary care and effective systemic targeted and nontargeted therapy, patient expectations of QOL, even during palliative end of care period is high. We lay emphasis on proving the diagnosis of metastasis by biopsy and histopathology and discuss imaging modalities to help estimate fracture risk and map disease extent. This article discusses at length the evidence and decision-making process of various modalities to treat skeletal metastasis. The modalities range from radiation including image-guided, stereotactic and whole body radiation, systemic targeted or hormonal therapy, spinal decompression with or without stabilization, extended curettage with stabilization, resection in select cases with megaprosthetic or biological reconstruction, percutaneous procedures using radio frequency ablation, cementoplasties and discusses the role of emerging modalities like high frequency ultrasound-guided ablation, cryotherapy and whole body radionuclide therapy. The focus lies on the role of multidisciplinary care, which considers complex decisions on patient centric prognosis, comorbidities, cost, feasibility and expectations in order to maximize outcomes on QOL issues.

Keywords: Bone metastases; Metastases; bone cancer; fracture; pathological; pathological fracture; skeletal metastases.

Figure 1

Varied radiological appearance of metastasis-lytic, mixed and blastic. (a) The radiograph of forearm with elbow joint anteroposterior view showing lytic metastasis from lung carcinoma occurring distal to the elbow (Note that metastases below the knee and elbow are rare) (b) The radiograph of hip joint with proximal thigh anteroposterior view showing an impending fracture from a lytic metastasis arising from a colonic primary. Pure lytic lesions are common with renal, lung, thyroid, uterine, adrenal, GI malignancies and melanoma (c) X-ray pelvis with both hip joints anteroposterior view showing extensive lytic and sclerotic metastases to pelvis and both femori from breast cancer. Mixed lesions are known with breast, lung, ovary, cervix, testicular malignancies and lymphoma (d) X-ray pelvis with both hip joints anteroposterior view showing pure sclerotic or blastic metastasis arising from a prostate carcinoma in a 70-year-old male. Pure blastic lesions are common with prostate, bladder cancers, medullary carcinoma thyroid and bronchial carcinoids

Figure 2

The plain radiograph (a) Underestimates the disease extent identified on magnetic resonance imaging (MRI) images (b) MRI can also identify and delineate soft tissue involvement, joint effusion, skip lesions and other crucial information like relation to neurovascular structures which can critically affect treatment plan

Figure 3

Workup of a patient with a symptomatic bony lesion or impending fracture or pathological fracture from suspected metastases

Figure 4

(a) A 50-year-old male with a pathological fracture shaft femur was assumed to have metastasis (b) He underwent immediate fixation with an intramedullary Nail and a derotation plate. No prior biopsy was performed. Figure shows the postoperative X-ray (c) Rapid growth of a bony hard mass at the fracture site a few weeks later prompted a referral. Note the exuberant bone formation (d) Histology proved to be an osteosarcoma (e) Resection involved removing the entire femur. Specimen is bivalved to show the tumor (f) Postoperative X-ray showing the total femur replacement. This would not be necessary were a proper workup done prior to surgery

Figure 5

This 54-year-old lady was treated for breast cancer 4 years prior to having this pathological fracture through the proximal femur. It was assumed to be metastasis. A radiologically obvious chondrosarcoma was missed. The treatment and prognosis were radically different, reinforcing the need for histopathological confirmation with a biopsy

Figure 6

MRI T2W sagittal image showing (a) metastasis with cord compression (prostate) (b) Response to orchidectomy can often be dramatic as shown in the image on the right and may obviate the need for immediate surgery

Figure 7

X-ray of the arms with shoulder joint anteroposterior view (a and b) showing local recurrence after previous cementing + fixation in renal cell carcinoma metastasis (c) Angiogram showing the hypervascularity. Preoperative embolisation is a must especially if intralesional surgery is contemplated (d) Resection specimen (e) Postoperative X-ray showing a nail-cement spacer. This is a cost effective construct in the upperlimb and sometimes in the lowerlimb

Figure 8

(a) Postoperative X-ray after intralesional curetting and cementing of a metastatic lesion from breast cancer (b) Local recurrence is seen within a year despite postoperative radiotherapy (c) Progressive disease which required resection. In patients with long expected survival, primary resection may obviate need for more surgery in future

Figure 9

A solitary diaphyseal metastasis from uterine leiomyosarcoma treated with resection and diaphyseal prosthesis. It allowed immediate weight bearing ambulation and preservation of native hip and knee

Figure 10

(a) Inverted ice cream cone prosthesis from Stanmore implants worldwide (Stanmore, UK) is useful in reconstructing large periacetabular defects and allows immediate weight bearing (b) The stem is hydroxyapatite coated and anchors in the strong posterior ilium while cement screw struts fashioned allow additional mechanical integrity. It can often be combined with a constrained liner to prevent dislocations (c) Postoperative x-ray showing the implant in place

Figure 11

X-ray of hip joint anteroposterior view showing challenge of cementing in intertrochanteric lesions. Calcar has to be built up to allow least chances of failure in a high stress zone

Figure 12

(a) Extensive involvement of distal femur and tibia in a case of renal cell carcinoma resistant to therapy. Intralesional surgery with cement had been done earlier (b) Composite resection of distal femur with proximal tibia over a fixed hinge prosthesis allowing immediate weight bearing

Figure 13

(a) Preoperative X-rays of a 70 year old with recalcitrant but indolent myeloma affecting the distal femur and tibial shaft (b) Reconstruction was done in a single step with a distal femur megaprosthesis with a custom tibial tray with a long stem. The patient, a practicing lawyer was back to work in 4 weeks after surgery

Figure 14

(a) Proximal humeral metastasis from thyroid cancer in a 55-year-old lady (b) Hypervascularity seen on the angiogram (c) preoperative embolization has obliterated hypervascularity (d) Resection was done as thyroid malignancies are associated with relatively long survivals even with extensive bony metastases. Resection greatly minimizes the risk of local recurrence. The embolization makes the surgery easier

Figure 15

(a) The radiograph depicts a 56-year-old male who presented with a pathological fracture while serving during a game of tennis. Biopsy revealed a metastatic cancer. Positron emission tomography-computerised tomography (PET-CT) showed this to be solitary metastases from renal cell carcinoma (b) Resection and reconstruction with a reverse shoulder type of implant (Stanmore Implants Worldwide, UK) preserving the deltoid muscle and axillary nerve allows better abduction and flexion

Figure 16

(a) Proximal radius lesion which on biopsy was a metastatic carcinoma. Positron emission tomography-computerised tomography revealed a lung primary with this lesion being a solitary metastasis (b) After chemotherapy, both lesions underwent resection. The radius was reconstructed with a custom intercalary prosthesis (c) Custom prosthesis, proximal and distal segments