Anterior Lumbar Interbody Fusion for Degenerative Discogenic Low Back Pain: Evaluation of L4–S1 Fusion

The treatment of degenerative discogenic pain is controversial, and anterior lumbar fusion for the treatment of degenerative discogenic low back pain has also been a controversial topic for over a generation. The aim of this systematic review was to evaluate the outcome of different anterior lumbar fusion levels for degenerative discogenic low back pain. In this study, we performed a clinical outcome subgroup analysis. The outcomes of 84 consecutive patients who underwent anterior lumbar interbody fusion from 2004 to 2009 were reviewed. The operative time, intraoperative blood loss, hospital stay, Oswestry Disability Index (ODI), visual analog scale (VAS) results, and complication rate were recorded separately. Medical indications were degenerative disc disease (73.8%), postdiscectomy disc disease (16.1%), and disc herniation (9.5%). Patients with severe spondylolysis or disc degeneration, with more than 3 or multilevel lesions, were excluded. The mean operative time was 124.5 10.9 min (range 51–248 min), the mean intraoperative blood loss was 242.1 27.7 mL (range 50– 2700 mL), the mean hospital stay was 3.9 1.1 days (range 3–6 days), the mean preoperative VAS score was 7.5 1.4, and the mean preoperative ODI score was 60.0 5.7. At the 1-year follow-up, the mean postoperative VAS score was 3.3 1.3 and the mean postoperative ODI score was 13.6 3.4 (P< 0.05). L4–L5 disc fusion led to better clinical results than 2-level L4–L5/L5–S1 disc fusion. Additionally, the 2-level fusion of L4–L5/L5–S1 had better clinical results than the L5–S1 disc fusion at both the 1 and 2-year postoperative follow-ups regarding the VAS score and the ODI score. The rate of complications was more frequent in the 2-level L4–L5/L5–S1 group (27.3%) (group C) than in the L4–L5 group (9.1%) (group A) and the L5–S1 group (12.5%) (group B). There was no difference between the L4–L5 group (9.1%) , MD, Ning Liu, MD, and Kirkham B. Wood, MD these patients underwent a spinal fusion with instrumentation, with a posterior approach after a mean of 1 year. The complications secondary to the surgical approach were persistent abdominal pain (1/84, 1.2%) and wound dehiscence (1/84, 1.2%). Anterior lumbar interbody fusion for L4–L5 had better clinical results than the 2-segmental L4–L5/L5–S1 disc fusion, and the 2segmental L4–L5/L5–S1 disc fusion had better clinical results than the L5–S1 disc fusion. Also, the 2-segmental L4–L5/L5–S1 disc fusion had a higher complication rate (27.3%), but there was no difference between the L4–L5 group (9.1%) and the L5–S1 group (12.5%). (Medicine 94(43):e1851) Abbreviations: ALIF = anterior lumbar interbody fusion, DDLBP = degenerative discogenic low back pain, LBP = low back pain, ODI = Oswestry Disability Index, TDR = total disc replacement, VAS = visual analog scale. INTRODUCTION L ow back pain was identified as ‘‘the leading’’ debilitating condition worldwide and represents a tremendous socioeconomic and health care burden. Although not always synonymous with each other, disc degeneration is regarded as one of the determinants related to the development of low back pain. The treatment of degenerative discogenic pain is also controversial. There are no prospective randomized controlled studies demonstrating that surgery is useful for degenerative discogenic pain. Most spine surgeons agree that discectomy alone usually is not helpful for degenerative discogenic pain. However, several longitudinal series strongly suggest that total disc replacement (TDR) relieves symptoms. Dynamic techniques and fusion are useful for degenerative discogenic pain. Lumbar TDR is indicated in the management of degenerative discogenic back pain without facet arthritis. However, many patients with degenerative discogenic back pain have facet arthritis, segmental instability, and loss of intervertebral height. More than 95% of patients with potential surgical indications are likely to have a contraindication for lumbar TDR. Recently, lumbar TDR was shown to be superior to fusion in cases presenting with lower adjacent-level degeneration. Dynamic techniques for spinal stabilization have also been described. The newer designs including the dynamic neutralization system for the spine (Dynesys Dynamic Stabilization System; Zimmer, Warsaw, IN) attempt to reduce motion equally in flexion and extension. There is no support for the superiority of dynamic stabilization compared to typical arthrodesis. The use of lumbar fusion has wider indications. Therefore, fusion will continue to be an essential part of the mentarium for the foreseeable future. fusion often complain of residual disiated with screw irritation, which makes www.md-journal.com | 1 surgeons believe that anterior interbody fusion may be a better option. Anterior lumbar interbody fusion (ALIF) removes this structure and replaces it with a bone transplant for the treatment of degenerative discogenic low back pain (DDLBP). ALIF has advantages compared to posterior lumbar interbody fusion because the anterior approach permits more extensive disc removal, avoids scarring of the neural canal, and preserves the posterior elements. The purpose of our study was to demonstrate the effectiveness of surgical therapy using ALIF. Additionally, we evaluated the outcome of different anterior lumbar fusion levels in patients with DDLBP. MATERIALS AND METHODS We reviewed the records of 84 consecutive patients who underwent ALIF from January 2004 to December 2009, with institutional review board approval of the authors’ institution. We included patients with severe and therapy-resistant DDLBP. The patients had more than 2 years of existing pain without ongoing psychiatric illness. All the patients failed to respond to conservative treatment including physical therapy and injections. The patients with severe spondylolysis or disc degeneration with more than 3 or multilevel lesions were excluded from this study. Degenerative changes (spondylosis) were shown on plain radiographs, computed tomography (CT) scan, and/or magnetic resonance imaging (MRI). There were no specific radiologic findings such as isthmic spondylolisthesis, spinal stenosis, new or old fractures, infection, inflammation, or neoplasm. There were no previous spine surgeries reported in the patients’ past medical histories, except for the successful removal of a herniated disc more than 2 years before entering this study. The diagnosis of DDLBP was confirmed by demonstrating a ‘‘black disc’’ on MRI along with the provocation of pain after discography. We confirmed the diagnosis of DDLBP by discography and discoblock (intradiscal injection) using lidocaine. All patients were identified by reviewing the ‘‘Electronic Patient Records.’’ All clinical notes including inpatient operative and discharge summaries were reviewed for a minimum of 2 years. The presence of preoperative severe DDLBP was assessed by the treating surgeon as emanating from L4–L5, L5–S1, or both. The DDLBP was not accompanied by any dominant leg pain component. The preoperative and postoperative clinical outcomes were evaluated using the visual analog scale (VAS) and the Oswestry Disability Index (ODI) for back and leg pain. VAS is one of the most commonly used measures of pain intensity in pain research, with a scale graduation of 0 to 10 cm (0 cm, minimal pain; 10 cm, maximal pain). ODI includes 10 sections of questions that evaluate the activities of daily living, such as sitting, walking, standing, sleeping, and so on, which can be drastically influenced by LBP. The total score ranges from 0 to 100, with 0 representing no disability and 100 representing maximum disability. The VAS and ODI scores before surgery, and 1 and 2 years after surgery were recorded and compared. If patients had persistent low back pain, then a CT scan was performed 1 year after surgery. We evaluated bone union by both radiograph and CT. Discography or Discoblock for the Diagnosis of Ni et al Degenerative Discogenic LBP Discography and discoblock were performed with a standard posterolateral approach using a 22-gauge needle. A 2 | www.md-journal.com discoblock is a modification of discography in which a local anesthetic such as lidocaine is infused with the contrast agent into the disc to enhance the diagnostic capability of the procedure. A contrast agent (range 1.0–1.5 mL) was injected into each disc until severe pain was provoked or contrast medium leaked from the disc into the spinal canal. If a leak occurred, then 0.5 mL of 1% lidocaine was injected into the disc. We confirmed the diagnosis of degenerative discogenic pain if the pain was provoked when using discography and decreased when using discoblock. We localized the degenerative discogenic pain level and performed surgery on 1 or 2 levels.