Influence of pedicle fixation on postoperative pain

From October 1988 through November 1990, 29 lumbar and lumbosacral spine fusion patients, 11 instrumented and 18 noninstrumented, were observed. Seventeen were men and 12 were women, with a mean age of 42.6 years (range, 22-83). The narcotic equivalent (NE) in milligrams/kilogram/day of medication used was analyzed. Age, sex, height, and weight were compared to the type, dose, mode, and duration of medication administration. Morphine was the reference point narcotic at 1.0:1.0. Levels fused, use of instrumentation, and prior surgery were related to NE. No significant differences in age, total body weight, height, levels fused, or hospital stay were established. There were 89.6% of patients over the ideal body weight by a mean 17.47 kg or 38.3 lb. The mean population NE was 3.76 mg/kg/day. Prior surgery patients tended to request narcotics intramuscularly for a longer period, while older patients tended to receive less medication. Patient obesity was related to lower NE. This study could not demonstrate a decrease in postoperative pain as it relates to the amount of narcotic medication received with the use of pedicle instrumentation.