OBJECTIVETo investigate retrospectively the clinical effects and recurrence rate of 143 cases who underwent one level discectomy and followed up more than 10 years. To evaluate the outcome of patients in groups of different operating age and extents of disc herniation, and analyse whether difference exists in each group.

METHODSThere were 143 patients (operation time from January 1996 to December 2000) including 80 males and 63 females, aged from 18 to 66 years old with an average of 37.85 years. The followed-up time was 10 to 15 years with an average of 12.7 years. Patients were divided into 3 groups depends on operating age: < 30 years old, 30 to 50 years old and > 50 years old; 87 patients who's pre-operative CT scan could be collected among 143 cases were divided into 3 groups depends on extents of disc herniation: I degree, II degrees, and III degrees. The final followed-up was obtained in 2011, to evaluate each group and the holistic clincal outcome with JOA scores and ODI scores, and observe whether there were difference between every groups; to judge the effects by patient himself with modified Macnab Criteria.

RESULTS(1) JOA scores pre-operation and final followed-up was 5.11 +/- 2.02 and 12.51 +/- 2.35 respectively; ODI scores pre-operation and final followed-up was 33.98 +/- 7.42 and 13.39 +/- 6.79 respectively. There were significant differences between pre-operative and final followed-up in JOA and ODI (P < 0.01). The excellent-good rate was 83.2% (119/143 ) according to modified Macnab Classification with recurrence rate of 6.3% at final follow-up. (2) Obvious difference was found in JOA scores in group who's age at operation less than 30 years old compared with other 2 groups at followed-up time, and no significant difference was found in JOA scores between other two groups ; no significant difference was found in ODI scores among the three groups. (3) Significant difference was found in JOA and ODI scores in group with III degrees lumbar disc herniation group compared with other 2 groups, and no statistical difference was found in clincal scores between other 2 groups.

CONCLUSION(1) Long-term followed-up of 143 cases prove mono-level lumbar discectomy is an option for disc herniation with good curative effect and lower recurrent rate, the technique should be the prior selection in dealing with patients with lumbar disc herniation. (2) 51% patients (19/37) in group under 30 years old endure persistent low back pain. (3) The long-term clinical effects in patients with severe disc protrution who underwent lumbar discectomy is worse than those patients with mild lumbar disc herniation.