Direct repair surgery with screw fixation in young patients with a pars defect of lumbar spondylolysis may not produce satisfactory outcomes at one-year follow-up, according to research published by the journal Spine.
Led by Gun Woo Lee, Armed Forces Yangju Hospital, Republic of Korea, the study group conducted their research in response to a lack of “clear information on the significance of direct repair and its outcomes in young patients with lumbar spondylolysis.” The authors note that previous studies have been conducted with patients of all ages in low-quality study designs that were retrospective in design and had a small sample size and short follow-up time.
Lee and colleagues suggest that direct repair has gained popularity in the treatment of younger patients due to its “inherent strengths compared with fusion surgery.” Fusion surgery prevents the affected segment performing its natural motion, thus aggravating degeneration of the adjacent segment. On the other hand, direct repair “preserves the motion in the affected segment and avoids problems” therein. Furthermore, direct repair for lumbar spondylolysis “can produce great outcomes regarding pain relief, functional improvement, and radiological outcomes such as fusion rate.” The authors believe that this is the first study to thoroughly describe “the therapeutic outcomes and significance of direct repair surgery for young patients with lumbar spondylolysis in a prospective interventional design.”
The prospective interventional study enrolled 47 patients with lumbar spine spondylolysis who were surgically treated with direct repair surgery and followed up for one year after surgery. Pain levels were assessed using the visual analogue scale, which was the primary outcome measure. Secondary outcomes included patient satisfaction, clinical outcomes based on Oswestry Disability Index (ODI) score and a 12-item short form health survey (SF-12), fusion rate of pars defect based on computed tomographic scans, and surgery-related complications.
Lee et al found that both the intensity and frequency of lower back pain had significantly improved at final follow-up compared with preoperative level (from 8.4±2 at baseline to 3.7±1.2 after one year; p<0.001). However, six patients (13%) had no significant improvement, and pain frequency tended to worsen six months after the operation. “One-year postoperative clinical outcomes (ODI and SF-12) significantly improved compared with preoperative levels, but the two scores also tended to decrease after six months,” reports Lee.
The union rate of the pars defect was 55% (26/47 patients), which was “definitely lower than expected”. That said, there was no significant difference in clinical outcomes between fusion group and non-union group of the pars defect at the final follow-up. In addition to the diminishing clinical improvements, only 25 patients (53%) were satisfied with their direct repair surgery.
Based on these results, authors conclude that “direct repair surgery in young patients with lumbar spondylolysis may produce unsatisfactory outcomes at one year after surgery in terms of degree of pain, clinical outcomes, and fusion outcomes”.