Skeletal metastases – The role of the orthopaedic and spinal surgeon

Abstract

Developments in oncological and medical therapies mean that life expectancy of patients with metastatic bone disease (MBD) is often measured in years. Complications of MBD may dramatically and irreversibly affect patient quality of life, making the careful assessment and appropriate management of these patients essential.

The roles of orthopaedic and spinal surgeons in MBD generally fall into one of four categories: diagnostic, the prophylactic fixation of metastatic deposits at risk of impending fracture (preventative surgery), the stabilisation or reconstruction of bones affected by pathological fractures (reactive surgery), or the decompression and stabilisation of the vertebral column, spinal cord, and nerve roots.

Several key principals should be adhered to whenever operating on skeletal metastases. Discussions should be held early with an appropriate multi-disciplinary team prior to intervention. Detailed pre-assessment is essential to gauge a patient’s suitability for surgery – recovery from elective surgery must be shorter than the anticipated survival. Staging and biopsies provide prognostic information. Primary bone tumours must be ruled out in the case of a solitary bone lesion to avoid inappropriate intervention. Prophylactic surgical fixation of a lesion prior to a pathological fracture reduces morbidity and length of hospital stay. Regardless of a lesion or pathological fracture’s location, all regions of the affected bone must be addressed, to reduce the risk of subsequent fracture. Surgical implants should allow full weight bearing or return to function immediately. Post-operative radiotherapy should be utilised in all cases to minimise disease progression.

Spinal surgery should be considered for those with spinal pain due to potentially reversible spinal instability or neurological compromise. The opinion of a spinal surgeon should be sought early, as delays in referral directly correlate to worse functional recovery following intervention. Patients who suffer a slowly progressive deficit, present within hours of complete neurological deficit, or have compression caused by bone alone are those most likely to benefit from surgery. Back pain in the presence of MBD should be regarded as impending spinal cord compression, and investigated urgently to allow intervention prior to the development of neurological compromise.

Introduction

Metastatic bone disease forms the final common pathway of many malignancies. Bone is the third commonest site of metastases after the lungs and liver. At post mortem 84% of patients with breast or prostate cancer have some form of skeletal deposits [1]. Patients with thyroid, lung and renal cancer have metastases in 50%, 44% and 37% respectively [2].

Although metastatic bone disease (MBD) seldom causes fatalities directly, it often dramatically and deleteriously affects quality of life. As oncological treatments have developed, life expectancy for patients with MBD has improved. Prognosis has been well reported; the median survival following diagnosis of MBD in patients with breast and prostate cancer is more than 2 and 3 years respectively [3], [4]. During this time patients are at significant risk of suffering skeletal related complications. This makes their appropriate management essential.

Advances in the fields of orthopaedic and spinal surgery mean many surgical options are available to treat skeletal metastases. Despite this the general levels of understanding of the role of surgery in MBD remain low. This unfortunately inevitably translates into the delayed or under-referral of patients that may benefit from surgery [5], [6].

This review outlines the role of orthopaedic and spinal surgeons in the management metastatic lesions of the appendicular skeleton and spine. We discuss the general principles of metastatic bone surgery, and some of the prophylactic, reactive and emergency scenarios where referral for consideration of surgery is appropriate. We also discuss the role of imaging, diagnosis and staging preoperatively, and propose which patients should be referred for an orthopaedic or spinal opinion, and those which are unlikely to benefit.