De novo degenerative lumbar scoliosis with stenosis and rotational olisthesis: What affects surgical outcome?

2010

SUMMARY

This prospective study of 58 patients with degenerative lumbar scoliosis, stenosis and listhesis and followed 4 years showed significant improvement in VAS and ODI (P=0.001) with surgical treatment. Patients developing nonunion had poorer outcomes (P=0.001). Factors not affecting outcome: chief complaint(back pain, back and leg pain, weakness, imbalance), age, interbody BMP dose, pre-op deformity severity, pre-op sagittal imbalance, fusion length, fusion to S1, correction achieved, co-morbidities, smoking, and all other complications.

INTRODUCTION

Degenerative lumbar scoliosis (DLS) is a common source of pain and disability in the aging population. Surgery to correct the stenosis, instability, and deformity can be complicated for patient and surgeon. We analyzed the factors affecting outcomes in surgery for DLS.

METHODS

Prospectively collected data on 58 consecutive patients with DLS, stenosis, and listhesis who underwent decompression and posterior instrumented deformity reduction and fusion at a single center and were followed 48 months (25-82 months). Average age: 68 years (49-80); 16 had previous surgery, 8 were smokers. Fusions averaged 7.4 levels (4-17 levels), 42 fused to S1; rhBMP-2 at 7.6mg/disc (2-12mg) used in 39 TLIF, 19 ALIF. Chief complaints: back pain-23, back and leg-29, gluteal pain–3, leg pain–1. Stenosis was present at average 3.4 levels. Co-morbidities were noted. Outcomes included VAS, Oswestry (ODI), medication records, and full radiographic follow-up measuring scoliosis curve, sagittal T10-L2, lordosis T12-S1, coronal and sagittal balance, and pelvic incidence.

RESULTS

Most common complications: adjacent degeneration-22, fracture-7, nonunion-7. Patients had significant improvement surgery: VAS pre-6.4, 1 yr-2.5, 2 yr-3.2, (P=.001); ODI pre-50, 1 yr-24.0, 2 yr-29.6, (P=.001). Pain medication requirements dropped accordingly. The only predictors of inferior outcome was development of a nonunion (P=0.001). Not associated with outcome: Chief complaint (back pain, back and leg pain, weakness, imbalance), age, BMP dose, pre-op deformity severity, pre-op sagittal imbalance, fusion length, fusion to S1, correction achieved, co-morbidities, smoking, and all other complications. Curve correction averaged 68%.

CONCLUSION

In DLS patients undergoing surgery, significant improvement is achievable regardless of the specific surgical requirements, co-morbidities, and clinical presentation. The only complication affecting outcome was nonunion.

SIGNIFICANCE

Achieving a solid arthrodesis in Degenerative Lumbar Scoliosis should be a high priority as it is the main predictor or inferior outcome following surgical treatment.