Osteoporosis and Vertebral Column

Abstract

Background: Osteoporosis is an age-related metabolic disease which has a significant impact on bone health and overall quality of life. It is gaining importance as a major medical consideration with the rapid increase in geriatric population globally. It increases the risk of vertebral fractures, progressive spinal deformities and neurological complications, contributing significantly to morbidity and mortality. Increase in life expectancy and advancement of medical technology has led to an increase in the proportion of geriatric patients undergoing orthopaedic procedures. It is becoming vital to adequately evaluate, investigate and treat osteoporosis before planning spinal surgery, especially spinal fusions and instrumentation.

Content: Historically, osteoporosis was considered a contraindication to spine surgery adding to the burden of Disability Adjusted Life Years (DALYs) and mortality. Conversely, osteoporotic patients who underwent spine surgery were not adequately optimized, leading to an increase in failure and complication rates. Better understanding of the pathophysiology of osteoporosis and the biomechanics of an osteoporotic spine with knowledge of current standards of treatment of osteoporosis facilitate the timely and adequate management of this disease. Advances in surgical and anaesthetic techniques facilitate successful surgeries on high-risk elderly and osteoporotic patients with multiple comorbidities allowing for a significantly high predictability for long-term positive outcomes.This article discusses the biomechanics of the osteoporotic spine, the diagnosis and management of osteoporotic patients with spinal disease, and the new treatments, recommendations, surgical indications, strategies and advances in instrumentation in patients with osteoporosis who require spinal surgery.

Implications: In this article, the authors aim to provide a generalized overview for better understanding of the pathophysiological processes underlying osteoporosis in the vertebral column. This review provides a comprehensive set of guidelines for overall health and management of spine patients with pathologies, either caused by or compounded with osteoporosis. An overview of current techniques, strategies and technologies designed to address the challenges associated with spine surgery in osteoporotic patients is also outlined.

Sources: Content for this article has been sourced from routinely cited articles available via PubMed, from National Institute of Health consensus development conference, from the recommendations by World Health Organization technical report series, from previous articles by the authors and from the protocols established by the authors in their clinical practice based on experience and detailed case reviews.

Keywords: Degenerative kyphosis; Degenerative scoliosis; Degenerative spondylolisthesis; Fragility fracture; Instrumentation; Osteoporosis; Osteoporotic vertebral fracture; Stenosis; Vertebral compression fracture.

Fig. 1

Pathogenesis of osteoporotic vertebral fractures [4]

Fig. 2

Factors influencing fracture healing in osteoporotic bones [4, 15]

Fig. 3

Thoracolumbar spine: increased kyphosis in sitting compared to supine position

Fig. 4

Kummel sign with opening and closing on supine versus sitting radiograph

Fig. 5

Genant classification of osteoporotic vertebral fractures [19]

Fig. 6

MRI showing vertebral body fracture, Kummel sign and marrow oedema

Fig. 7

Mechanism of action of anti-osteoporotic therapies [30]