Introduction
Posterior lumbar interbody fusion (PLIF) is a widely accepted procedure for many lumbar degenerative disorders. However, it has been suspected for causing significant postoperative pain in the first few months.
Patients and methods
This prospective study included 36 consecutive patients who underwent a single-level PLIF procedure and were followed up for at least 1 year. At one-year follow-up, there were 20 females and 16 males, with an average age of 60.7 y (range: 39–81 y). All patients were operated in a standardized fashion, with bone graft taken from the iliac crest. Postoperatively, all patients received a standardized analgesic regimen. The modified Oswestry disability index (ODI) and visual analog score (VAS) were assessed preoperatively, at 3 months, at 6 months, and at 1 year postoperatively. Patients who had an obvious surgical reason for postoperative pain such as pedicular screw misplacement, postoperative hematoma, infection, wound problems, loose osseous fragment impingement on neural structures and postoperative pedicle, vertebral body, endplate fracture, or sacroiliac joint violation were excluded from the study.
Results
The most common indication for PLIF was lumbar stenosis with instability (=18) and at 1-year follow-up, all 36 patients achieved bony intervertebral body fusion. The average preoperative ODI was 67.33% (range: 56–82%), and the mean preoperative VAS was 7 (range: 5–9). At 3 months, there was a significant improvement in relation to the preoperative ODI and VAS ( less than 0.0001 for both). Yet, at 6 months and at one year, there was a significant improvement when compared with the preoperative ODI and VAS (<0.0001 for both). The largest improvement of ODI occurred between the third and sixth postoperative month (13%), whereas the largest improvement of VAS occurred between the sixth and 12th postoperative month (2.13). The most common source of pain was the iliac crest graft but tended to resolve completely at 1 year postoperatively. Four (11.11%) patients had slight to moderate pain after one year at the iliac crest. Three patients (8.33%) had persistent slight to moderate low back pain.
Conclusion
For many patients, PLIF is a painful experience, and strict adherence to the details of the operation are necessary to optimize the overall outcome. Still, the iliac crest graft is a major source of postoperative pain, although there is a significant overall improvement of the ODI and VAS at 1 year, and most patients report that they benefited from this operation. This series is based only on a single-center experience, and hence larger multicentric studies are needed to produce reliable data. Confounding this small series is individual pain perception and the inherent subjectivity of the ODI and the VAS.