Higher preoperative Oswestry Disability Index is associated with better surgical outcome in upper lumbar disc herniations

Abstract

To evaluate the surgical outcome in terms of functional and subjective recovery, patients who needed discectomies at L1-L2, L2-L3 and L3-L4 levels were compared with an age and sex-matched group of patients who required L4-L5 and L5-S1 discectomies. We prospectively enrolled 50 consecutive patients, referred to our center, who had L1-L2, L2-L3 and L3-L4 herniations and required surgical intervention. Likewise, a comparative group of 50 consecutive patients with herniations at L4-L5 and L5-S1 were selected. All 100 patients were treated and followed for a 1 year period. Physical examination findings as well as Oswestry Disability Questionnaire before surgery were recorded. After 1 year, patients were requested to fill the same questionnaire. Significant decline in the Oswestry Disability Index (ODI) scores was considered to be a measure of functional improvement and recovery. The mean age of patients with upper lumbar disc herniation (L1-L2, L2-L3, L3-L4) was 45.7 years and patients with lower lumbar disc herniation (L4-L5, L5-S1) had a mean age of 41.2 years. There was no statistically significant difference in age between the two groups. The preoperative Oswestry Disability (ODI) Index score had a statistically significant impact on ODI score improvement after surgery in both lower and upper lumbar disc groups. All 100 patients with either lower or upper lumbar disc herniation had statistically significant ODI change after surgical intervention (P < 0.0001 for both groups). However, patients with upper disc herniations and moderate preoperative disability (ODI of 21-40%) did not show significant improvement, while patients with ODI greater than 40% had significant reduction (P = 0.018). Surprisingly, as many as 25% of the former had even an increase in ODI scores after surgery. Gender was also a conspicuous factor in determining the surgical outcome of patients with upper lumbar disc herniation, and male patients had more reduction in ODI score than female patients (P = 0.007). Since the functional recovery in patients with herniated lumbar disc, especially upper lumbar herniation, is influenced by preoperative ODI scores, the use of ODI or any other standard pain assessment tool is a sensible consideration as an inherent investigative method to preclude unfavorable surgical outcome.

Fig. 1

Box plot of Oswestry Disability Index reduction in patients with upper (a) and lower (b) lumbar disc herniations

Fig. 2

Box plot of Oswestry Disability Index reduction in terms of gender in patients with upper (a) and lower (b) lumbar herniations