Introduction The frequency of spine surgery in the elderly continues to increase in parallel with the overall aging of the population. The main goal of this study was to determine if age is a risk factor for major complications in spine surgery. In addition, other co-morbidities and the relationship with age and potential for major complications were explored.

Methods All adult patients undergoing spine surgery at our center over a four-year period were included in this study, for a total of 1937 patients (605 age 18 – 39; 1001 age 40–64, 331 age 65 and over). One independent observer abstracted baseline medical histories and co-morbidities as well as post-operative complications. Major risk factors explored included history of cardiac, cancer, smoking, diabetes, substance abuse, obesity, respiratory problems, previous infections and hypercholesterolemia. Details of surgical procedure, including type of surgery, duration of surgery and blood loss were also captured. Major complications were defined as death, CVA, embolism, pneumonia and deep wound infections.

Patients ranged in age from 18 years to 91 (average age 48 years) and 41% were males. Thirty percent of the population was deformity patients, 49% degenerative patients and the remaining 21% had various other spine problems. Thirty-five percent of the patients underwent a combined anterior posterior procedure, 13% anterior alone and 34% posterior alone.

Statistical analysis included descriptive summary, vicariate correlation to assess individual risk factors (university analysis) and multivariate regression.

Results The overall major complication rate was 2.1% (40 patients). There were no intra- or post-operative deaths. Major complications included 7 CVA (0.4%), 2 embolisms (0.1%), 3 deep wound infections (0.2%) and 28 pneumonia (1.4). For patients age 65 or older,

Overall, 61% of the patients had at least one of the major risk factors. The number of major risk factors increased with increased age. The percent of patients with any given risk factor also increased with age.

When no other factors were taken into account (such as co-morbidities), there was an increased occurrence of a major complication (any one), pneumonia and infection with increased age at time of surgery. In order to differentiate the effect due to age and due to co-morbidities (which increased with age), multivariate regression was utilized. For the occurrence of any major complication, the presence of respiratory problems and previous infection were both more influential than age. Furthermore, when the effects of these two risk factors were controlled for, there no longer was an effect due to age.

Discussion Older patients did not have an increased rate of major complications when compared to younger patients with similar respirator and infection history profiles.