PSEUDOARTHROSIS OF THE LUMBAR SPINE - OUTCOME AFTER CIRCUMFERENTIAL FUSION

Study Design. Twenty-five patients with a pseudarthrosis after previou s spinal fusion surgery were reviewed after a circumferential fusion w as performed. Objectives. To determine the fusion rate and its relatio n to outcome, i.e., pain reduction and return to work, and associated complications. Summary of Background Data. Circumferential fusion has become a common procedure with more patients undergoing multiple opera tions. The operation is thought to improve the fusion rate with a low complication rate. However, the procedure has not been evaluated speci fically for the management of pseudarthrosis. Methods. Twenty-five pat ients were reviewed regarding age, gender, smoking status, previous ba ck surgeries, extent of leg and back pain, occupation, levels of surge ry, type of instrumentation, blood loss, and complications. A minimum follow-up period of 2 years included evaluation of radiographs, pain l evels, medication, and return to work. Results. Twenty percent of pati ents were heavy smokers. An average of 2.2 previous procedures had bee n performed, and the average follow-up period was 2-7 years. Eighty pe rcent of patients underwent multiple-level fusions. A solid fusion was achieved in 100%. Complications included two painful instrumentation devices requiring removal, one retroperitoneal hematoma, one anterior abdominal wall dehiscence, and one case of pneumonia. Pain scores impr oved from 7.4 to 4.7 for back pain, and 5.4 to 2.8 for leg pain, respe ctively. Both improvements were statistically significant (P < 0.01 an d 0.003, respectively). However, only 52% of patients reduced their pa in by a full category. Forty-one percent were still taking narcotics i ntermittently or consistently, and 53% returned to work or were active ly seeking employment. Discussion. A fusion rate of 100% was noted in the face of factors often placing patients at high risk for developing a pseudarthrosis, namely multiple levels of previous spinal surgery, including previous pseudarthrosis, and a habit of heavy smoking. Compl ications were few. However, the satisfactory outcome rate was only som ewhat better than 50%, based on a lack of substantial pain improvement and return to work.