Pre-operative Optimization for Adult Spinal Deformity Surgery

The incidence of adult spinal deformity (ASD) continues to increase with our aging population. Surgeries not considered possible or reasonable 20 years ago are now being performed on a regular basis, with good results but complication rates are high. It is the cost of complications, particularly those that leads to reoperation and readmission, that makes this kind of surgery unsustainable for the economy as a whole. Through a multi-disciplinary team evaluation of patients considered for surgery, improvements in outcomes and decrease in complications can occur. Critics of this approach claim this denial of care.  While it is true that some patients are just not candidates for surgery, it is our belief that many may not currently be a candidate, but could become one when their overall health is optimized.

Preoperative Patient Factors

Albumin

• Albumin is measurable protein in our blood. Preoperative albumin levels of 3.5 g/dl or lower is associated with a 13.8 chance of dying and a 2.5 chance of developing a wound infection and is an independent factor predicting readmission.

Smoking

• The use of nicotine, particularly smoking, is known to cause a wide range of health problems, including lung cancer and other forms of cancer.
• Smoking is also associated with an increased risk of medical complications after adult spinal surgery including wound problems and non-healing of the bone and fusion. Patients may need help to quite smoking prior to surgery.

Bone Mineral Density

• Several studies identified an association between decreased BMD and screw loosening in adult spinal surgery.
• Bone density is an indication of the strength of the bone and when it is low, you have osteoporosis, which is associated with a higher risk of reoperation.
• A DEXA scan is used to screen for osteoporosis and specific medications might be needed prior to surgery, including Vitamin D, when you have osteoporosis.

Preoperative Hemoglobin

• Hemoglobin is and indicator of the amount of iron in your blood and directly correlated to the capacity of the red blood cells to carry oxygen.   
• There is an association between a low preoperative hemoglobin and complications and increased need for a blood transfusion. Several studies also indicate a longer length of stay in the hospital and more complications including a higher incidence of death in the first 30 days. 
• Hemoglobin level of lower than 12 should be worked up prior to surgery.

Body Mass Index

• Obesity is now widely recognized as a significant health problem in the United States and elsewhere. The Centers for Disease Control and Prevention (CDC) currently uses the following ranges and definitions as they relate to BMI:  Underweight <18.5; Normal 18.5to <25; Overweight 25 to <30; Obese 30 or higher.  They further categorize obesity as Class 1 (BMI 30 to < 35), Class 2 (BMI 35 to < 40), or Class 3 (BMI 40 or greater). 
• Patients with a BMI ≥ 30 kg/m2 was associated with a higher incidence of major complications and wound infections as well as rod fractures and implant failures. BMI increases the risk of proximal junctional kyphosis, or topping off at the top of the construct.
• We recommend Weight Management and even bariatric surgery to achieve the desired goal, but many patients are able to lose the needed weight through modified eating habits alone.  Improved diabetic control and blood pressure are two of the positive side effects from losing weight.

Frailty

• Frailty is defined as age-associated declines in physiologic reserves and function across several organ systems.  The modified Frailty Index (mFI) is a scale that uses 11 of the 70 variables proposed by the Canadian Study of Health and Aging Frailty Index. 
• Complications are increased in frail patients.
• We believe this is an important part of the preoperative assessment of patients prior to major spinal surgery.  Exercising pre-surgery and staying active is encouraged.

Hemoglobin A1c

• Diabetes Mellitus is currently an epidemic in the United States and parts of Europe and is a leading cause of death and disability in the Western world. 
• It serves as an evaluation of the average amount of glucose in the blood over the previous 2-3 months.  A normal level is a HbA1c below 5.7%.  Pre-diabetes is HbA1c between 5.7% and 6.4% and diabetes is generally identified as a HbA1c of 6.5% or higher. 
• Improved diabetic control can lessen the risk of complications with surgery.  Increased levels above 7 is associated with infection. It is critical to control blood sugar levels before and during surgery.

Mental Health

• Impaired mental health has been known for years to affect spinal complaints. Studies have shown a correlation between impaired mental health and diminished outcomes after spine surgery.  However, there was tremendous variability in the measures used to evaluate mental health. 
•  Your provider will ask you to fill out several forms in an attempt to assess your mental health. You might need to see a counsellor prior to surgery.

Vitamin D

• Vitamin D is produced by the body in response to exposure of the skin to sunlight and it occurs naturally in some foods (some fish and egg yolks) and in fortified dairy and other products.  It is essential to aid the body in utilizing calcium to maintain proper mineralization of bone. 
• The two commonly measured forms of Vitamin D are Vitamin D2 (ergocalciferol) and Vitamin D3 (cholecalciferol).  Both of these can be converted in the body into the active form of the vitamin D.
• Levels below 30 ng/ml is associated with a higher complication rate. You might need to take supplemental Vit D, before and after surgery and lifelong in order to maintain your bone health.

Conclusion

Our surgical techniques and implants to treat adult spinal deformity have progressed remarkably over the last 20 years; however, our complication rates remain unacceptably high.  The optimization of patients’ co-morbidities has the potential to help us reduce these complications and enable us to deliver better and safer care to the growing number of patients with adult spinal deformity.

Provided by the SRS Patient Education Committee