Bone Health Optimization (BHO) in Spine Surgery

Abstract and Introduction

Abstract

Study Design: Literature review

Objective: To educate spine surgeons on the importance of bone health optimization in surgical patients.

Summary of Background Data: Osteoporosis is common and underdiagnosed in spine surgery patients. Poor bone health has been linked to worse outcomes and complications after spine surgery. Guidelines are available to inform decision making on screening and treatment in this population.

Methods: Available literature is reviewed regarding bone health screening and treatment. Studies reporting outcomes related to osteoporosis, bone density, and vitamin D status are summarized. Pharmacologic treatment and nutritional considerations are discussed. Bone health optimization practice models and outcomes are also reviewed.

Results: Bone health screening should be considered in all adults over age 50. Gender-specific guidelines are available to determine which patients need dual-energy x-ray absorptiometry. Osteoporosis can be diagnosed by dual-energy x-ray absorptiometry T-score, fracture risk calculator or by history of low-energy fracture. Advanced imaging including computed tomography and magnetic resonance imaging can be used to opportunistically assess bone health. If diagnosed, osteoporosis can be treated with either antiresorptive or anabolic agents. These medications can be started preoperatively or postoperatively and, in high-risk patients, surgical delay can be considered. The implementation of bone health optimization programs has been shown to greatly increasing screening and treatment rates.

Conclusion: Bone health assessment and optimization are important for decreasing surgical risks and improving outcomes in spine surgery patients.

Introduction

Optimization of co-morbid conditions is commonly performed preoperatively to reduce adverse events and improve surgical outcomes. Edwards et al.^[1] described ten conditions that should be optimized before total joint replacement that are widely adopted. Examples include assuring adequate glucose control in diabetic patients, stratifying cardiac risk to determine who needs further evaluation, nasal screening and decolonization for staphylococcus and correcting nutritional deficits. However, poor bone health has received much less attention despite it being common in spine surgery patients and being associated with poorer outcomes and increased likelihood of adverse events.^[2] Bone health optimization (BHO) is the process to identify those at risk for osteoporosis, identify and correct metabolic and nutritional abnormalities and, when indicated, provide bone-active medical treatment preoperatively and postoperatively.^[3] The goal of BHO is to improve outcomes and reduce complications in a cost-effective manner.

The purpose of this manuscript is to inform spine surgeons about best practices for bone health optimization. These include methods for screening, diagnosing, and treating diminished bone quality in patients undergoing planned spinal fusion. The rationale to consider bone health evaluation and treatment will be explored. Using current guidelines, the process of how bone health optimization can be implemented in an office setting will be discussed. Finally, the reader will understand the potential benefits of bone health optimization.

Table 1. Classification of Osteoporosis
World Health Organization
Category	DXA T-score
Normal	>−1.0
Osteopenia	−1.0 to −2.4
Osteoporosis	≤−2.5
Clinical diagnosis of osteoporosis5
Lowest T-score ≤−2.5* History of low-energy hip or spine fracture T-score −1.0 to −2.4 and fragility fracture of pelvis, proximal humerus, or wrist T-score −1.0 to −2.4 and high FRAX based on community specific thresholds

*On the basis of DXA lowest T-score of hip, femoral neck, or 1/3 radius.
DXA indicates dual-energy x-ray absorptiometry; FRAX, fracture risk assessment tool.

Table 2. Indications for DXA Testing in Patients Undergoing Spine Surgery ^43,44
Women ≥65 yr
Men ≥70 yr
Fragility fracture after age 50 yr
FRAX ≥8.4% sans BMD

BMD indicates bone mineral density; DXA, dual-energy x-ray absorptiometry; FRAX, fracture risk assessment tool.

Table 3. Risk Stratification for Bone Health Optimization
Risk Category	Criteria*	Treatment	Surgical Delay
Normal/low risk	FRAX MOF risk<10% No Fracture after age 50	Optimize Calcium/Vitamin D	None
Osteopenia/intermediate risk	Lowest T-score −2.4 or better No prior fracture FRAX MOF risk <20%	Optimize Calcium/Vitamin D	None
Osteoporosis/high risk	Lowest T-score −2.5 to −3.0, Recent fracture (within 2 yr) FRAX MOF risk 20–30%	Optimize Calcium/Vitamin D Antiresorptive or Anabolic Rx	Consider delay
Severe osteoporosis/very high risk	Lowest T-score ≤−3.0 FRAX MOF risk >30% recent fracture Multiple prior fractures	Optimize Calcium/Vitamin D Anabolic Rx if possible	Delay 3–9 mo if possible

-Opportunistic CT (HU<110 at L1).
-VBQ on MRI >3.
-Revision surgery.
-Multilevel spine procedure.
-Failure related to bone (e.g., loosening).
*Modifiers that increase risk.
CT indicates computed tomography; FRAX, fracture risk assessment tool; HU, hounsfield units; MOF, major osteoporotic fracture; MRI, magnetic resonance imaging; VBQ, vertebral bone quality.