Friday, September 28, 2018 3:00 PM–4:00 PM abstracts: optimizing lumbar disc surgery: 212. Surgery versus standardized nonoperative care for the treatment of lumbar disc herniations with 4-12 months of symptoms

Abstract

BACKGROUND CONTEXT The beneficial treatment effect surgery demonstrates over conservative care for radiculopathy secondary to acute lumbar disc herniation (LDH), occurs in the first three to six months, thereafter outcomes are recognized to be similar. This is not surprising given the favorable natural history; 90% will experience gradual resolution of their symptoms within 4 months. In Canada, due to the inherent wait time to see a surgeon and the referring physician's expectation that most patients will improve without surgery, symptomatic patients presenting to surgeons are often the 10% that have remained symptomatic longer than the expected 4 months. Little is known about the effectiveness of treatments for this population with chronic sciatica. PURPOSE The purpose of this study is to determine if surgery is superior to conservative care in a patient population that has had persistent symptoms for more than four months. STUDY DESIGN/SETTING A single blinded (assessor) prospective randomized control trail performed at a single academic center. PATIENT SAMPLE We enrolled 18-60 year old patients with a unilateral, single radiculopathy from a posterolateral L4-5 or L5-S1 disc herniation. Radiculopathy duration had to be greater than 4 months but less than 12 months. OUTCOME MEASURES The primary outcome was numerical rating scale (NRS) for intensity of leg pain (0–10) and Oswestry Disability Index (ODI) measured at 6 months following treatment. Secondary outcome measures included NRS for back pain and leg pain, ODI, SF-36, work status, and satisfaction and is reported for 6 weeks, 3, 6, and 12 months follow-up. METHODS Patients on a waiting list to see surgeons at one academic hospital center were invited to a study screening session. Participation in the study expedited the patient's care to receive almost immediate care by either a study surgeon or physiatrist. Consented patients were randomized to early microdiscectomy or standardized nonoperative care including medications, education, physiotherapy, and steroid injections. Patients were excluded prior to randomization if they had previously received these conservative modalities or they were not a candidate for/or agree to possible lumbar discectomy. At the time of randomization, all patients randomized to the nonoperative treatment group were placed on the surgical consultation waiting list of one of the participating surgeons and were re-assessed for surgery when they reached the top of the regular waiting list. This waiting list is a minimum of six months. Therefore, the opportunity for cross-over to surgery at our center due to ongoing radiculopathy was possible only after a minimum of six months had passed following randomization, which was the primary outcome time point. RESULTS A total of 168/376 patients screened were determined eligible for enrollment.A total of 40 patients refused study participation. A total of 64 patients were randomized to early surgery and 64 to nonoperative care. There was no difference between groups in demographic characteristics or pretreatment patient-rated outcome measures. PretreatmentNSR leg pain was 8.0 (SD 1.8) for the nonoperative cohort and 7.7 (SD 2.0) for the surgical cohort. Pretreatment ODI was 50.2 (SD 15.9) for the nonoperative cohort and 49.7 (SD 15.8) for the surgical cohort. At the 6 months primary outcome data was available for 51/64 patients in the surgical cohort (11 missed visit, two withdrew) and 54/64 patients in the nonoperative cohort (eight missed visits, two withdrew). At 6 months NSR leg pain improved to 5.1 (SD 3.0) and 2.9 (SD 2.9) for the nonoperative and surgical cohorts respectively (p=.0001), while the ODI improved to 33.2 (SD 19.1) and 23 (SD 19.7) respectively (p=.008) on the intent-to-treat analysis. Treatment effect for all secondary outcome measures favored surgery. 22 patients in the nonoperative cohort crossed into surgical treatment; two received surgical treatment in another city at 8 weeks following enrollment which violated study protocol, 20 received surgery more than 6 months after enrollment by a study surgeon. Eight patients randomized to surgical treatment did not receive surgery; one developed a cardic event precluding surgery, seven patients improved before surgery and surgery was cancelled. A time-weighted overall treatment effect favored early surgery over delayed surgery (the 22 patients which crossed-over) for ODI, NSR back and leg pain, SF-36 physical and mental component summary scores. CONCLUSIONS Microdiscectomy is superior to nonoperative care for patients presenting with sciatica lasting greater than 4 months secondary to lumbar disc herniation.