Original Article Management of Single Level Lumbar Degenerative Spondylolisthesis: Decompression Alone or Decompression and Fusion

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1 Egyptian Journal of Neurosurgery Volume 9 / No. 4 / October - December Original Article Management of Single Level Lumbar Degenerative Spondylolisthesis: Decompression Alone or Decompression and Fusion ARTICLE INFO Received: 9 December 014 Accepted: 4 April 015 Key words: Degenerative lumbar spondylolisthesis, Claudication pain, JOA score, Lumbar fusion Mohamed I Refaat* Department of Neurosurgery, School of Medicine, Cairo University ABSTRACT Background: Degenerative spondylolisthesis is the second common form of spondylolisthesis, it typically occurs at the level of L4-L5. Patients present with intermittent low back pain, neurogenic claudication, and occasionally radicular pain. Only 10% to 15% of patients may need surgery. Surgical options include spinal decompression alone, or decompression with fusion. Objective: This study is comparing the results of decompression alone and decompression with fusion for degenerative spondylolisthesis. Patients & Methods: Sixty patients with degenerative spondylolisthesis were included in this study. All cases failed to respond to conservative measures for at least three months. Patients were randomly divided in two groups, Group (A) patients were operated upon by decompression and posterolateral instrumental fusion, while Group (B) patients were operated upon by decompression alone. Results: Fifty seven of our cases (95%) showed improvement, regarding their clinical symptoms, 5% of cases didn t show any improvement. None of our cases showed deterioration than their preoperative state. No statistical significance was found between recovery rates in both groups. There was no statistical significance between complication rates of both groups. The hospital stay was significantly shorter in the non-fusion group than the fusion group. Conclusion: Degenerative spondylolisthesis is more commonly seen in females in their 5 th and 6 th decades. It affects commonly L4/5 and L5/S1 spaces. There was no statistical significant difference when comparing the recovery rates of decompression alone, and decompression followed by fusion. The incidence of complications was the same in both groups. The only significant difference in this study was a longer hospital stay in the fusion group in comparison to the non fusion one. 014 Egyptian Journal of Neurosurgery. Published by MEDC. All rights reserved INTRODUCTION The term Spondylolisthesis describes the forward displacement of one vertebra in relation to another. There are five types of listhesis according to the Wiltse-Newman-MacNab classification system; the isthmic, degenerative, dysplastic, traumatic, and pathologic forms 4. Junghans in 1931 was the first to describe degenerative spondylolisthesis as a specific form of listhesis with an intact neural arch. Degenerative spondylolisthesis may be either primary or secondary, primary degenerative spondylolisthesis is commonly seen in middle-aged females presenting with spinal stenosis. Secondary degenerative spondylolisthesis occurs as a result of a predisposing factor, such as adjacent segment degeneration above a fused level 1,5. Degenerative spondylolisthesis is the second common form of spondylolisthesis after the isthmic type, it typically occurs at the level of L4-L5, followed *Corresponding Author: Mohamed I Refaat Department of Neurosurgery, School of Medicine, Cairo University mrefaat77@yahoo.com, Tel.: +/ by L3-L4 and L5-S1 levels. Older people are most commonly affected; the average age at presentation being 60 years. It is four times more likely to occur in women than men. The causative factors and their related importance remain unclear. Osteoporosis is implicated in the sagittal orientation of the joints and disruption of the disc. Another important factor is the relative immobility of the segment below the lesion. Immobility is commonly caused by hemisacralization, but can also result from advanced disc degeneration. Spinal fusion is an iatrogenic cause for immobility 11. Clinically patients frequently complain of intermittent low back pain, neurogenic claudication, occasionally radicular pain from compression by the degenerative facet 4. Imaging includes plain X-ray standing lateral, anteroposterior, oblique & flexion/extension views, CT and MRI of lumber spine 1. The natural history of degenerative spondylolisthesis is generally favorable, only 10% to 15% of patients will need surgery. Treatment includes conservative care and surgical treatment indicated for patients with progressive neurological deficit and those Egyptian Journal of Neurosurgery 51

2 who fail to improve with conservative measures. Surgical options include spinal decompression alone, or decompression and instrumental fusion 6. PATIENTS AND METHODS This study included sixty patients of lumbar degenerative spondylolisthesis. All cases tried conservative measures for at least three months of active physiotherapy program, non-steroidal anti-inflammatory medications & lumbosacral brace before surgical treatment. The patients were randomly assigned into two groups according to the surgical approach used in treatment. : included patients who did decompression and instrumented fusion, and : included patients who did decompression only. Cases were operated upon in the Neurosurgery Department, Kasr El-Aini Hospitals, Cairo University between January 011 and December 013. Full preoperative neurological examination was done for all cases. The Japanese Orthopedic Association (JOA) evaluation system for low back pain was used to evaluate the patients before and after surgery. Cases were subjected to neuroradiological investigations in the form of plain X-ray lumbosacral spine anteroposterior, lateral, oblique and dynamic stress views, as well as MRI of the lumbosacral spine. Cases were operated upon by adequate decompression of the stenotic level; laminectomy was performed in all cases. The decompression procedure extended laterally. Unilateral or bilateral medial facetectomy was done to decompress nerve roots. Discectomy was done if significant disc bulge was found (Fig 1). Only in group (A) cases, this was followed by posterolateral intertransverse fusion, augmented by pedicle screws and rods/plates for the affected level (Fig,3). a b c d Fig. 1 a-d: a, b: Preoperative dynamic x-ray and c: Sagittal MRI of a 47 years old female with L4/5 degenerative Spondylolisthesis. d: Postoperative lateral x-ray after decompression only. The patient s JOA improved from 5 to 13, with improvement rate 86.8%. 5 Egyptian Journal of Neurosurgery

3 a b c d Fig. a-d: a&b: Preoperative dynamic x-ray. c: sagittal MRI of a 50 years old female with L4/5 degenerative Spondylolisthesis. d: Postoperative lateral x-ray after decompression and fixation. The patient s JOA improved from 6 to 15, with improvement rate 93.1%. a b Fig. 3 a&b: a: Sagittal MRI of a 56 years old male with L4/5 degenerative Spondylolisthesis. b: Postoperative lateral x- ray after decompression and fixation. The patient s JOA improved from 6 to 15, with improvement rate 100%. Immediate post-operative and at 6-months intervals postoperative evaluation with JOA scores assessment, and full neurological examination was done for all cases. The mean follow-up period was 18 months (range 1-4 months). Immediate and late post-operative X-ray was done. MRI was performed after surgery to confirm adequate decompression. Results after surgery were assessed according to the recovery rate of the JOA score, and were classified into a four-grade scale: excellent, improvement of above 90%or more; good, 75 89%; fair, 50 74%; and poor, below 49%. Recovery rate (RR) % = Post-operative score Pre-operative score Full score pre-operative score. x 100% Egyptian Journal of Neurosurgery 53

4 RESULTS The data collected from sixty cases of surgically managed lumbar degenerative spondylolisthesis was analyzed. Thirty cases were treated by decompression and instrumented fusion (), while thirty cases were treated by decompression only (). The age of patients ranged between 4 years and 59 years. The mean age was 50 years in group (A), and 5 years in group (B). 73% of the cases of group (A) were females while only 50% of the cases of group (B) were females. Hard laborers were 61% in group (A), while they were only 43% in group (B). The mean Body mass index (BMI) in group (A) was 3.5, and 31.7 in group (B). The mean duration of symptoms was 1 months in group (A), and 7 months in group (B). Back pain, claudication pain, and paravertebral muscle spasm were the most common presenting features, followed by sensory deficits. Motor weakness was found in only 3 cases in group (A) (Table 1). Preoperative JOA score ranged from 5 to 8, with mean value Group (A) cases had significant lower mean low back pain score than group (B) cases, while group (B) cases had significant lower mean walking ability and straight leg raising scores than group (A) (table ). Table 1: Clinical presentations among the two groups Clinical presentation Group (A) Group (B) Significance By chi-square (x ) Back pain 30 (100%) 30 (100%) NS Claudication pain 30 (100%) 30 (100%) NS Sciatica 11 (37%) 13 (43%) P=0.014 Motor deficits 3 (10%) 0 NS Sensory deficits 4 (80%) 15 (50%) NS Paravertebral muscle spasm 30 (100%) 7 (90%) NS Palpable step 3 (10%) (7%) NS The most common level for Spondylolisthesis was L4/5 (60% of cases), followed by L5/S1 (5% of cases) in both groups. Postoperative JOA scores ranged from 9 to 15, with mean value of No statistical difference between the two groups as regards the postoperative scores, except that group (B) had significant lower walking ability scores (table ). Group (A) had excellent recovery in 43.3%, good recovery in 40%, fair recovery in 13.3%, and poor recovery in 3.3% of cases. While group (B) had excellent recovery in 30%, good recovery in 50%, fair recovery in 13.3%, and poor recovery in 6.7% of cases. This showed no statistical significance between both groups (table 3). Table : Pre and postoperative JAO scores of both groups Mean score Preoperative score Postoperative score Change Low back pain Leg pain Walking ability Straight leg raising test Sensory abnormality Motor deficit Total JOA score Egyptian Journal of Neurosurgery

5 Table 3: Improvement rates of both groups Recovery Significance By chi-square (X ) Excellent 13 cases (43.3%) 9 cases (30%) NS Good 1 cases (40%) 15 cases (50%) NS Fair 4 cases (13.3%) 4 cases (13.3%) NS Poor 1 case (3.3%) cases (6.7%) NS Five cases had superficial wound infection (3 in group A and in group B), CSF leak occurred in four cases (two belonging to each group). No statistical significance was found in the complication rates in both groups. The mean hospital stay was significantly higher in group A (4. days) than in group B (.7 days). DISCUSSION Nonoperative methods are effective in the treatment of most patients with symptomatic degenerative spondylolisthesis and spinal stenosis. Initial treatment consists of short-term activity restriction and nonsteroidal anti-inflammatory drugs. Physical therapy along with massage, heat, ultrasound, may be used as well. Ultimately, patients are recommended to establish a regular exercise program 6. Surgery was advised to patients in this study who failed to respond to a reasonable trial of non-operative treatment for a minimum of 3 months. The mainstay of surgical treatment is decompression. Most of the current studies about spondylolisthesis are reflecting the recent trend towards fusion, but the significantly shorter recovery times of simple decompression continue to make the latter tempting. There is no general agreement about the indications for fusion. Indications for instrumentation are even more controversial 8. The mean age of our cases was 50 years which is lower than many studies. Jacobsen et al, reported a mean age of 68 years in men and 71 years in women 7. As regard sex distribution we noted female predominance in 68% of cases coinciding with Jacobsen et al, (83%) 7. Female predominance is inconclusively explained by generalized joint laxity due to hormonal factor, weak back muscles and obesity. Laborers, doing heavy house work were reported in 57 % of our cases, which was not significantly correlated to degree of spondylolisthesis or severity of symptoms. This coincides with Jacobsen et al, who reported that lifting heavy weights was not associated with degenerative Spondylolisthesis 7. As regards to the clinical picture, we noted that back pain and claudication pain were the most common presenting features, this almost corresponds to the findings of Plotz & Benini who reported predominance of severe back pain 84% of their studied cases 9. The most common affected level in our study was L4-5 (60% of cases) followed by L5-S1 (5% of cases). This coincides with Jacobsen et al who reported L4-5 in 67% of cases and L5-S1 in 17% of cases 7. Concerning postoperative complications, we found no significant difference in complication rate between the two studied groups. We had two main postoperative complications, superficial wound infection and CSF leak. Ghogawala et al. reported similar rate of superficial infection and no difference in complication rate between fusion and decompression group 3. Hospital stay was significantly higher in fusion group than non-fusion group; several authors repotted this finding 7,3. Group (A) cases had 86% mean improvement rate (mean preoperative JOA score 6.6 and mean postoperative score13.8). Group (B) cases had 8.3% mean improvement rate (mean preoperative JOA score 6.5 and mean postoperative score 13.5). However, these values showed no statistical significance. Satomi et al reported improvement rates of 77% and 55.7% in both groups respectively 10. CONCLUSION Degenerative spondylolisthesis is more commonly seen in females in their 5 th and 6 th decades. It affects commonly L4/5 and L5/S1 spaces. There was no statistical significant difference when comparing the recovery rates of decompression alone, and decompression followed by fusion. The incidence of complications was the same in both groups. The only significant difference in this study was a longer hospital stay in the fusion group in comparison to the non-fusion one (by an average of 1.5 days). REFERENCES 1. Alijani B, Emamhadi M, et al: Posterior interbody fusion and posterolateral fusion: analogous procedures in decreasing the index of disability in patients with Spondylolisthesis. Asian J Neurosurg 10(1):51, Devine J, Skelly A: Risk factors of degenerative Spondylolisthesis: a systematic review. Evid Based spine Care J 3():5-34, Ghogawala Z, Benzel E, et al: Prospective outcomes evaluation after decompression with or without instrument fusion for lumbar stenosis and Egyptian Journal of Neurosurgery 55

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