Original Article First 30 Days Outcome of Conventional Discectomy for De Novo Lumbar Disc Herniation

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1 Egyptian Journal of Neurosurgery Volume 30 / No. 3 / July - September Original Article First 30 Days Outcome of Conventional Discectomy for De Novo Lumbar Disc Herniation 1 Mohamed Nosseir * and 2 Afify Hossam 1 Department of Neurosurgery, Ain Shams University, Cairo, Egypt 2 Department of Neurology, Ain Shams University, Cairo, Egypt Received: 14 July 2015 Accepted: 28 November 2015 Key words: Diagnostic performance, Lumbar disc herniation, L5 Radiculopathy, Early outcome, Patient s satisfaction 2015 Egyp an Journal of Neurosurgery. All rights reserved ABSTRACT Background: A lot of literature exists on almost every aspect of lumbar disc pathology. However, limited studies have looked at the early outcome of disc surgery and patient s satisfaction with respect to pre-operative expectation. Objectives: Our study meticulously outlines the early outcome of pain and neurologic deficit after discectomy as well as assesses patients satisfaction in the early post-operative period. Patients and Methods: One hundred consecutive patients with de novo lumbar disc herniation operated in our department between January and December 2014 were prospec vely followed-up. All patients were assessed pre-operatively and postopera vely on Days 1, 7 and 30 for low back pain, radiculalgia (using the Visual Analogue Scale), neurologic deficit and patient s satisfaction by a verbal patient satisfaction index graded from 0-100%. Results: The mean age was 39.9±9.7 years and male to female sex ra o was 3:2. All pa ents had low back pain (LBP), radicular pain in 88% andnerve root stretch signs in 91% of cases. Pre-opera ve motor deficit was found in 18% and Sensorydeficit in 29%.L45 herniated disc was the most common (66%), disc protrusion was the most frequent (59%).In seventy nine pa ents (79%)the fragment posi on was posterolateral. Severe sciatica was the most common indica on for surgery (85%) and fenestra on was done in 64% of cases. Remission of radicular pain was faster than for LBP and the difference was sta s cally significant (p<0.01).we had 14% post-op complica ons 7% of which were CSF leak managed with favorable outcome. The Mean pa ent sa sfac on was 81.5% (±19.8 SD). Conclusion: Post operative alleviation of back pain is slower, variable and inconsistent than for sciatica. Thus the selection of patients for disectomy with predominantly low back pain should be cautioned by good clinical judgment. In preoperative consenting, patients should be informed on the slower remission of low back pain to limit postoperative dissatisfaction when results do not meet expectation. INTRODUCTION Since 1934 when Mixter and Barr established that a prolapsed lumbar intervertebral disc was commonly the cause for sciatica 1,2, a multitude of papers have been published exploring almost every aspect of lumbar disc pathology 3. 5 Lumbar disc herniation (LDH) is one of the most common pathology encountered in routine neurosurgical practice. With a prevalence of 1-3%, LDH or its sequelae account for an important proportion of discomfort, debility and destitution 4. A patient with LDH usually presents with a characteristic clinical picture of low back pain and/or radicular pain, sensory and/or motor deficit, reflex changes and presence of nerve root stretch signs. Occasionally they present with a cauda equina syndrome a veritable neurosurgical emergency 3. Undoubtedly surgical treatment is advantageous for the treatment of HLD especially the alleviation of sciatica 5,6. * Corresponding Author: Mohamed Nosseir, MD Department of Neurosurgery, Ain Shams University, Cairo, Egypt dr_nosseir@yahoo.com; Tel.: It is also a well-known fact that the outcomes of surgical intervention are unsatisfactory in some cases of herniated lumbar disc (HLD). 7 The substantiation of realistic expectations and development of pre-screening methods can simplify patient selection and improve on disc surgery outcome 4. Many criteria for measuring outcomes are used albeit mostly from retrospective studies 6. Common criteria for outcome assessment include: social limitations, disability, physical activity, daily living activity, changes in personality traits, or relief of back and leg pain. The Visual Analogue Scale (VAS) for pain assessment, the Oswestry Disability Index that includes social and physical limitation are the most common tools used for evaluating surgical outcome. 5 Limited studies have looked at the early outcome of lumbar disc surgery as well as patient s satisfaction with respect to pre-operative expectation. 8 Our study meticulously outlines the early outcome of pain and neurologic deficit after classical macrodiscectomy as well as assesses the patients satisfaction of surgery using a patient s verbal satisfaction index (0-100%) in addition to the traditional VAS (0-10). Egyptian Journal of Neurosurgery 227

2 228 PATIENTS AND METHODS Study Design, Setting and Period Prospective descriptive Cohort Study: One hundred consecutive patients with de novo lumbar disc herniation operated in our department between January and December 2014 were prospectively followed-up. Study Population (Participants) All consecutive patients with (de novo) lumbar disc herniation (n=100 cases) were included in our study. Indications for surgery were: Severe Sciatica (Relative Indication), failure of conservative treatment after 5-8 Weeks, profound/progressive neurologic deficit and cauda equina Syndrome 8. Patients with recurrent herniated lumbar disc were excluded. Procedure The patients were assessed pre-operatively and post-operatively (Immediate (Day zero), on discharge, Week1 and 4) for low back pain and radicular pain, sensory and motor deficit, reflex changes, spinters and presence of nerve root stretch signs. For pain assessment, we used the Visual Analogue Scale (graded from 0-10), for the motor function using the Medical Research Council (MRC) Scale for Muscle Strength 9 ( graded on a scale of 0-5), and Overall Outcome was assessed using a Verbal Patient Satisfaction (graded from 0-100). All patients were assessed pre-operatively and postoperatively on Days 1, 7 and 30 for low back pain, radiculalgia, neurologic deficit and patient s verbal satisfaction. RESULTS Baseline Sociodemographic Features: A total of 100 patients were included in our study. The mean age was 39.9±9.7 years [Minimum=16Y Maximum= 65Y]. Sixty-one percent of our cases were males and thirty nine percent females (male to female sex ratio of 3:2). Fifty-four percent of our patients had a profession that required heavy intensity task and thirty nine percent in light intensity task. Seventy-three percent were obese (body mass index (BMI) 25Kg/m²). The mean BMI was 27.9±4.7 Kg/m² (minimum: 17.3 and maximum: 42.6 Kg/m²). 16% had an accompanying medical condition with diabetes occurring in seven cases (7%) and hypertension in eight cases (8%). One case of scoliosis (spinal deformity) and 23 patients revealed a history of minor back trauma. Thirty-six patients (36%) were smokers (1 was female).two cases (2%) had a positive family history of lumbar disc surgery in first-degree relatives. Clinical Presentation All patients had low back pain (LBP) with 70% being severe (VAS 7). The Mean duration of LBP was 23 months (Range:1-120 months). Radicular pain was present in 88% of cases and the mean duration of the pain (±SD) was 5±3 months. Median duration between LBP and radicular pain was 8.5 months (min=0 max=118) Nerve root stretch signs occurred in 91% of cases. Sciatica was most common on the left (45%), was on right in 32%, bilateral in 21%.Two patients had no sciatica. As regards neurologic deficit, pre-operative motor deficit was reported (symptom) in 14% of cases and found on examination (sign) in 18%. (Fig. 1) Sensory abnormalities of numbness/paresthesia were reported in 53% of cases but hypothesia was objectivated during physical examination only in 29%. (Fig.2) Fig. 1: Outcome of motor function Fig. 2: Outcome of Sensory Function Regarding reflex changes, an abnormal knee reflex occurred in twenty patients (20%),seven cases with either an L2-3 or L3-4 herniated disc and thirteen cases without a herniated disc at the corresponding level; an abnormal medial hamstring reflex occurred in fifty-five cases (55%), fifty cases with L4-5 herniated disc and five cases without a herniated disc at that level and an abnormal ankle reflex occurred in fifty-nine patients Egyptian Journal of Neurosurgery

3 (59%), thirty three cases with L5-S1 herniated disc and twenty six cases without a herniated disc at the corresponding level. There were two cases of caudaequina syndrome. There was no case with limb atrophy. Imaging Findings MRI disc level: L4-5 herniated disc was the most common and occurred in 66% of cases, followed by L5- S1which occurred in 40%. L1-2 was the least frequent (1%).Double level disc occurred in 17% of cases. Disc Type: disc protrusion was the most frequent in 59%, extrusion in 29%, and migration in 10%. There was only one case of sequestrated disc. Disc site: 79% were posterolateral, 20% central and one far lateral. Severe sciatica was the most common indication for surgery. (Table 1) Treatment Table 1: Indications for Surgery Indication N (%) Severe Pain (Radicular Pain) 85(85) Severe Pain + Weakness 10(10) Cauda Equina 2 (2) Weakness 3 (3) Failed Medical Treatment 1 (1) Surgical technique: Fenestration was done in 64% of cases, laminectomy in 34% and hemilaminectomy in 2%. (Fig. 3) Table 2: Time from admission to surgery and length of hospital stay Variable Mean± Min Max SD Waiting Time 3.9± (Admission-Operation)/Days Length of Hospital Stay/Days 4.4± Mean Change in Pain (Post-operative VAS score pre-operative VAS) Table 3: Outcome of Pain using VAS Variable Mean± S.D Min Max LOW BACK PAIN 3.4± RADICULAR PAIN 7.3± The mean change in pain (Post-op VAS score preop VAS) was 7.3 for radicular pain and 3.4 for LBP. (Table 3) Change in Low Back Pain Table 4: Outcome of Low Back Pain (VAS) VAS Low Back Pain PRE-OP Score: N(%) POST-OP: N(%) Mild 11 (11) 70 (70) Moderate 19 (19) 25 (25) Severe 70 (70) 5 (5) P-Value <0.05 (Fisher Exact test) Change in Radicular Pain Fig.3: Technique for surgical operations Outcome Our main outcome was pain: low back pain and radicular pain (sciatica & femoralgia) and secondary outcomes were neurologic function: motor, sensory, reflexes abnormalities. We also evaluated the complications and assessed the overall outcome by a verbal patient satisfaction index graded from 0-100%. Mean waiting time (from admission to operation) was 3.9 ± 2.7 days and average length of hospital stay was 4.4±4.8 days. (Table 2) Table 5: Outcome of Radicular Pain VAS Radicular Pain PRE-OP Score: N(%) POST-OP: N(%) Mild 5 (5) 94 (94) Moderate 7 (7) 5 (5) Severe 88(88) 1 (1) P-Value <0.05 (Fisher Exact test) Remission of radicular pain is faster than for LBP and the difference was statistically significant (p<0.01). (Fig. 4) Egyptian Journal of Neurosurgery 229

4 Two patients presented with severe numbness and three with weakness in lower limb. Weakness is considered a complication if it was of lower grade than pre-operative grade. (Fig. 6) Fig.4: Kaplan Meier Remission for Low Back Pain and Radicular Pain One new case of numbness. One had resolved completely by Day-30 after surgery. Neurologic Deficit: Reflex Changes No change in reflexes in the early (first 30 days) post-operative period. Neurologic Deficit: Autonomic Changes No change in spincteric function in the early (first 30 days) post-operative period for the two cases with caudaequina syndrome. Complications Intraoperative complications: Unintended durotomy (6 cases), wrong level (1 case), root injury (2 cases). (Fig.5) Fig. 2: Post-operative Complications The mean length of hospital stay was higher for 6.4 days for patients with a complication and 3.3 days for patients with an uneventful post-operative period. (Table 6) Table 6: LOS in Complicated vs Non Complicated cases Group n Mean±Std. Dev. [95% Confidence Interval] Complication=Yes ±5.1 ( ) No Complication ±4.4 ( ) Combined ±4.8 ( ) P=0.04 t-test Patient Satisfaction (Verbal Patient Satisfaction Index) The Mean patient satisfaction was 81.5% (±19.8 SD). Fourteen (14%) of the patients admitted there weren t satisfied with the results of surgery. (Table 7) Fig.1: Per-operative Complications Post-operative complications: We had 14% of immediate post-operative complications. Seven (7%) of which were CSF leak managed with favorable outcome educing the one week post-operative complication to 7%. There was one case with no intra-operative dural tear but CSF leak in the post-operative period. Table 7: Patient Satisfaction (Verbal Patient Satisfaction) Patient Verbal Frequency Percentage Satisfaction EXCELLENT ( 80%) GOOD (60-80) POOR ( 60%) There was little correlation between the Patient verbal satisfaction Index (PSI) and duration of low back pain (left) and radicular pain (right). (P-value >0.05). (Fig. 7) 230 Egyptian Journal of Neurosurgery

5 Fig. 3: Correlation between the PSI and Low back pain (left) /Radicular pain (right). Illustrated Case 1 (Fig. 8) Fig. 4: L4-5 Herniated Lumbar Disc presenting with CaudaEquina Syndrome (CES). Ruptured Central L4-5 HLD in a 41 year-old female presenting with CES. Emergency L4 laminectomy and macrodiscectomy. Improvement in neurologic status by day 30 except for incontinent urinary sphincters. DISCUSSION The prevalence of sciatic symptoms reported in the literature varies considerably ranging from 1.6% in the general population to 43% in a selected working population 10. Although the prognosis is good in most patients 11, a substantial proportion (up to 30%) continues to have pain for 1 year or longer 12,13. HLD characteristically presents with a clinical picture of low back pain and/or radicular pain, sensory and/or motor deficit, reflex changes and presence of nerve root stretch signs and occasionally with a caudaequina syndrome 3. Multiple systematic reviews have revealed that surgical discectomy for carefully selected patients with sciatica due to lumbar disc prolapse provides faster relief from the acute attack although any positive or negative effects on the lifetime natural history of the underlying disc disease are still unclear 14,15. The outcomes of treating HLD have been evaluated in a number of studies 4,5,7,11,12,14,15 most of which used the Visual Analogue Scale (VAS) for pain assessment, the Oswestry Disability Index that includes social and physical limitation for overall outcome assessment 5. In our study we used the VAS and patient s verbal satisfaction index. A total of one hundred patients were included in our study all operated by classical macrodiscectomy for de novo HLD (Fig.). The mean change in pain (Postoperative VAS score minus pre-operative VAS) was for radicular pain and -3.4 for LBP implying there was reduction in post-operative pain more pronounce with radiclular pain. Likewise the remission of radicular pain was faster than for low back pain difference, which was statistically significant (Error! Reference source not found.). These conclusions are in agreement with the data obtained by Sharma MK 8 who assessed pain on discharge using a modified Oswestry Disability Index, and G. Waddell 3 which also attested to pain reduction in patients with the same pathological condition during the postoperative stages according to the data reported by the patients regarding their walking, sitting, and sleeping ability. The pain severity assessed by VAS score was lower at the postoperative stages, which is in agreement with the data obtained by O. Hagg et al. 16, who reported similar results in patients with spine disorders. In their study, 294 patients treated for chronic low back pain were evaluated with a visual analog scale for back pain, the Oswestry Disability Index, the Million Score and general function score for disease-specific disability, and the Zung Depression Scale for depressive symptoms. They also concluded that patient global assessment is a valid and responsive descriptor of overall effect in randomized controlled trials of treatment for chronic low back pain 16. With regards to neurologic function there was mild change in motor and sensory deficit within the early Egyptian Journal of Neurosurgery 231

6 post-operative period. (Fig. 1 & Fig. 2) There were no changes in reflexes in the early (first 30 days) postoperative period and autonomic (sphincter function) remained the same in this study. Evidence from literature reveals that neurologic function usually requires longer periods to regain normal function 3. In this study, CaudaEquina shows little clinical improvement at the short-term (<1year) follow-up especially in patients treated remotely from the onset of symptoms. Long-term follow-up is mandatory to evaluate the real outcome of surgical managed in patients with neurologic deficit. We had 13% per-operative and 14% (week 1) postoperative complications, half of which were unintended durotomies and CSF Leak that resolved before discharge. (Fig. 5) The overall patient satisfaction using the verbal PSI was excellent in seventy-five cases (75%) but poor in fourteen cases (14%). The PSI correlated weakly with duration of pain, inversely correlated with pain severity and was strong associated with post-operative complications (Table 7 & Fig. 3). CONCLUSION Disectomy leads to rapid relief and gives more satisfactory short term results for radicular pain than for low back pain. Post operative alleviation of back pain is slower, variable and inconsistent than for sciatica. Thus the selection of patients for disectomy with predominantly low back pain should be cautioned by good clinical judgment. In preoperative consenting, patients should be informed on the slower remission of low back pain to limit post-operative dissatisfaction when results do not meet expectation. Disclosure: The authors have no personal, financial or institutional interest in any of the drugs, materials, or devices described in this article. REFERENCES 1. Mixter WJ, Barr JS: Rupture of the Intervertebral Disc with Involvement of the Spinal Canal. N Engl J Med 211: , Parisien RC, Ball PA: William Jason Mixter ( ). Ushering in the "dynasty of the disc". Spine (Phila Pa 1976 )23: , Christopher E Wolfla: Lumbar Disc Herniation, Setti S. Rengachary, Richard G. Ellenbogen: Principles of Neurosurgery. Elsevier Mosby, 2005, pp Carragee EJ, Han MY, Suen PW, Kim D: Clinical outcomes after lumbar discectomy for sciatica: the effects of fragment type and anular competence. J Bone Joint Surg Am85-A: , Ronnberg K, Lind B, Zoega B, Halldin K, Gellerstedt M, Brisby H: Patients' satisfaction with provided care/information and expectations on clinical outcome after lumbar disc herniation surgery. Spine (Phila Pa 1976 )32: , Stambough JL: Lumbar disk herniation: an analysis of 175 surgically treated cases. J Spinal Disord10: , Stromqvist B, Fritzell P, Hagg O, Jonsson B: Oneyear report from the Swedish National Spine Register. Swedish Society of Spinal Surgeons. Acta Orthop Suppl76:1-24, Sharma MK, Chichanovskaia LV, Shlemskii VA: [A comprehensive study of early outcome (at the time of discharge from the hospital) after lumber discectomy for degenerative spine disease.]. Zh Vopr Neirokhir Im N N Burdenko77:30-34, Paternostro-Sluga T, Grim-Stieger M, Posch M, Schuhfried O, Vacariu G, Mittermaier C, Bittner C, Fialka-Moser V: Reliability and validity of the Medical Research Council (MRC) scale and a modified scale for testing muscle strength in patients with radial palsy. J Rehabil Med 40: , Konstantinou K, Dunn KM: Sciatica: review of epidemiological studies and prevalence estimates. Spine (Phila Pa 1976) 33: , Legrand E, Bouvard B, Audran M, Fournier D, Valat JP: Sciatica from disk herniation: Medical treatment or surgery? Joint Bone Spine74: , Weber H: Lumbar disc herniation. A controlled, prospective study with ten years of observation. Spine (Phila Pa 1976) 8: , Vroomen PC, de Krom MC, Slofstra PD, Knottnerus JA: Conservative treatment of sciatica: a systematic review. J Spinal Disord13: , Gibson JN, Waddell G: Surgical interventions for lumbar disc prolapse: updated Cochrane Review. Spine (Phila Pa 1976 )32: , Jacobs WC, van TM, Arts M, Rubinstein SM, van MM, Ostelo R, Verhagen A, Koes B, Peul WC: Surgery versus conservative management of sciatica due to a lumbar herniated disc: a systematic review. Eur Spine J 20: , Hagg O, Fritzell P, Oden A, Nordwall A: Simplifying outcome measurement: evaluation of instruments for measuring outcome after fusion surgery for chronic low back pain. Spine (Phila Pa 1976) 27: , Tamburrelli FC, Genitiempo M, Bochicchio M, Donisi L, Ratto C: Caudaequina syndrome: evaluation of the clinical outcome. Eur Rev Med Pharmacol Sci 18: , Egyptian Journal of Neurosurgery