【PURPOSE】Anterior instrumentation surgery for thoracolumbar spinal diseases is a reasonable procedure when major pathology is located in the anterior part of the spine. However, it tends to be avoided due to the complexity and the large invasiveness of the procedure. This tendency is especially strong in elderly patients because of many comorbidities and severe osteoporosis. The purpose of this study is to investigate the outcomes of thoracolumbar anterior spinal instrumentation surgery performed in elderly people and to clarify its merits and demerits.
【METHODS】From April 2012 to March 2022, 3072 cases of thoracolumbar spine surgeries were performed in our institute out of a total of 3472 spinal surgery cases. Among these, 1484 cases associated with fusion surgery were investigated. Inclusion criteria were: 1) age 65 years or older, 2) same surgeon, 3) thoracolumbar burst fracture or pseudoarthrosis after osteoporotic vertebral fracture, 4) anterior fusion associated with anterior instrumentation, 5) neurological deficits involving spinal cord, nerve roots and/or cauda equina, and 6) minimum 2-year follow-up after the surgery. Variables investigated were the operation time, blood loss, and postoperative complications. Pre- and postoperative QOL was evaluated using Roland-Morris Disability Questionnaire (RDQ) and Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ). Radiographic evaluation was performed in terms of bone union, instrument-related complications, and local kyphotic angle.
【RESULTS】There were 16 patients (9 males and 7 females; age 66 - 89 years with an average of 77.6 year). Level of fracture was T12 in 8 patients, L1 in 5, L2 in 2, and T11 in 1. Subtotal vertebrectomy, followed by reconstruction with anterior instrumentation (2-screws&2-rods), was performed in all patients. Autologous rib strut graft was placed on both sides of the expandable cage for anterior column reconstruction. Excessive correction of local kyphosis was not performed to prevent instrument-related complications. The average operation time was 5h&7m + 1h&20m, and the average blood loss was 856+247ml. Neurological symptoms improved in all patients. The average local kyphosis was 29.2° preoperatively, 12.7° immediately after surgery, and 18.5° at the final follow-up. Two of 16 patients (12.5%) developed instrument-related complications and required additional posterior fusion. RDQ improved from 18.1 to 9.5 preoperatively and at the final follow-up. The JOABPEQ score (5 domains; pain, lumbar function, walking function, social life, psychology) also improved from 21, 25, 19, 21, 29 to 57, 61, 51, 55, 53, respectively. There were no postoperative infections or respiratory complications.
【DISCUSSION】The current retrospective study demonstrated that anterior spinal reconstruction using anterior instrumentation could successfully treat more than 80% of the elderly patients with thoracolumbar anterior pathology causing neurological deficits. However, a potential risk associated with surgical approach exists regarding respiratory complications especially on open thoracotomy. Careful consideration on selecting surgical procedure is mandatory to manage elderly patients.