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Cite this article: Mhaskar VA, Pai SN (2015) Epidural Steroid Injection: A Convenient Short Term Alternative to Fenestration Discectomy in Lumbar Disc Herniation. JSM Neurosurg Spine 3(2): 1057.

*Corresponding authorVikram A. Mhaskar, 5/407 Mowbray Road, Chatswood, New South Wales, Australia, Tel: 0416866047; Email

Submitted: 22 March 2015

Accepted: 07 April 2015

Published: 09 April 2015

Copyright© 2015 Mhaskar et al.

OPEN ACCESS

Keywords•SF36•VAS•Epidural steroid injection•Fenestration discectomy•Stroke•Blood pressure•Hypertension

MRI•Recovery

Research Article

Epidural Steroid Injection: A Convenient Short Term Alternative to Fenestration Discectomy in Lumbar Disc HerniationVikram A. Mhaskar1* and Sudhir N. Pai2

1Department of Orthopaedics, Royal Prince Alfred Hospital, Australia2Department of Orthopaedics, Saint John’s Medical College Hospital, India

Abstract

Background: To test the null hypothesis that epidural steroid injection and fenestration discectomy equally improve the quality of life over six months in patients with lumbar disc herniation and to compare the pain component of the SF 36 questionnaire and VAS scale with physical impairment.

Methods: Prospective study of 51 patients, 27 of which underwent epidural steroid injection and 24 fenestration discectomy with evidence of lumbar disc herniation on MRI using the SPORT (Spinal Outcomes Research Trial) eligibility criteria from April 2009 and February 2012.

Results: Of the 51 patients, 27 were treated with Epidural steroid injection and 24 with Fenestration Discectomy, at 6 months primary outcomes of Physical Functioning, Energy /Fatigue, Emotional, Pain and General health improved in both groups with no statistically significant difference between the two, Social Functioning did not improve significantly. There was a statistically significant variation of end line as well as percentage change in physical index score with SF36 and VAS scores.

Conclusions: There was significant improvement in quality of life of life of patients treated with both epidural steroid injection and fenestration discectomy with no statistically significant difference between the two groups at all intervals till six months. There was no significant difference between the VAS and pain component of SF 36 scale in measuring improvement in pain. The improvement in quality of life co related with the improvement in physical signs and symptoms.

ABBREVIATIONSESI: Epidural Steroid Injection; SF36: Short Form 36; VAS:

Visual Analogue Scale

INTRODUCTIONBack pain is now an international health issue of major

significance. About 80% suffer from this at some time in their life, ranked as the most frequent cause of limitation of activity in people younger than 45 years by the National Centre for Health Statistics. Only routine examinations post-operative check-up and upper respiratory tract symptoms surpass back problems as a cause of office visits to physicians [1]. Disc herniation is an important cause of low back pain with L3-4 and L4-5 showing maximum predisposition for disc degeneration [2,3].

Disc prolapse accounts for 5% of lower back disorders and is one of the most common causes for surgery [4]. Treatment for

lumbar disc herniation can be conservative or surgical, and which one is effective is always controversial [5]. Choosing the best form of treatment has always posed a challenge to the treating physician. Popular forms of conservative treatment are physical therapy, epidural steroid injection, chiropathy, anti-inflammatory agents and opioid analgesics which are a lot cheaper and less invasive than surgical techniques [4]. Epidural steroid injection is a very popular and low risk alternative to surgical intervention in lumbar disc herniation. It enjoys reasonable success rates for alleviation of radicular symptoms from lumbar herniated discs [6]. Fenestration discectomy as a surgical procedure is less time consuming with less blood loss, less post-operative complications and does not compromise the stability of the spine when compared to laminectomy and discectomy [7]. However it is a surgical procedure and entails the risks of complications associated with any surgical procedure. One needs to weigh the benefits versus the fallacies associated with any intervention before advocating it as a routine treatment measure.

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This study intends to compare the changes in quality of life of individuals with low back ache and radiculopathy for at least six weeks, undergoing epidural steroid injection or fenestration discectomy using the SF 36 and VAS scales, over a period of six months. With this study we intend to explore whether the solution to a crippling problem can be non- surgical (epidural steroid injection) and whether it can be an effective long term alternative to fenestration discectomy for single level disc herniation.

MATERIALS AND METHODSSubjects and Methods

This study was conducted from April 2009 to February 2012 in patients between the age group 20years - 65years. 51 patients were recruited in all. 27 underwent epidural steroid injection and 24 fenestration discectomy. The patient was evaluated by an independent surgeon pre and post operatively.

Inclusion criteria

Back pain and radiculopathy for at least six weeks in an adult male/female with evidence of lumbar disc herniation as a single level protrusion occupying > 25 % of the spinal cross sectional area on an axial section MRI and had been counselled about the requirement of a fenestration discectomy were included.

Exclusion Criteria

Patients with back pain for less than six weeks and with evidence of more than single level lumbar disc herniation on MRI, those with the disc occupying < 25% of the spinal cross sectional area measured on an axial section, asymptomatic individuals with/without evidence of lumbar disc herniation on MRI, those with osseous cause for lumbar canal stenosis on MRI, individuals with signs of lumbar disc degeneration without lumbar disc herniation, patients who previously underwent discectomies, epidural steroid injections, patients with associated spinal pathologies and cauda equina syndrome and patients without radiculopathy even if there was evidence of lumbar disc herniation on MRI with low back ache were excluded.

Patients were assessed clinically, a thorough history and clinical and neurological examination was carried out, the subjective symptoms and objective signs were recorded. This was followed by routine pre-operative investigations as well as a MRI scan of the lumbosacral spine of all the patients to confirm the diagnosis. The study was conducted for a period of six months on a patient. The change in quality of life was evaluated by administering the SF36 quality of life questionnaire and Visual Analogue Scale (VAS).

a) Before the start of treatment b) two weeks after the completion of treatment

c) one month after the completion of treatment d) six months after completion of the treatment.

Those candidates that underwent surgical treatment after the epidural steroid injection were excluded.

The scoring was done according to the SF36 scoring system and VAS scales.

Operative Procedure of Discectomy by the Fenestration Method

Patient was positioned in the prone knee chest position, care being taken to see if the abdomen is free to prevent undue engorgement of the epidural veins and thus decrease the extent of intraoperative blood loss. The affected lumbar space was localized using X ray intra op.

A vertical midline incision was made after localizing the level of the disc. The para-spinal muscles were retracted and the inter-laminar space exposed. Only the ligamentum flavum was excised, without removing any part of the lamina. The cord was retracted, the disc herniation identified and discectomy carried out using disc removing forceps. The entire disc at that level was removed. The cord and the roots are confirmed to be decompressed and lying freely in their respective canals. The wound was closed in layers and dressing done.

Epidural steroid Injection Dosage and Procedure

The patient was positioned in the left lateral position/sitting in the epidural steroid injection room .The level of the disc was pre-determined by MRI. The drugs to be injected were kept ready. The mixture used contained 40 mg Triamcinolone acetate which corresponds to approximately 4 ml, mixed with 4 ml of 0.5% sensorcaine and 12 ml of normal saline to make a 20 ml mixture according to the anesthesia department’s protocol. This mixture was then injected in the epidural space one level higher to the level of disc herniation causing compression via interlaminar technique.

An IV cannula was placed in situ for at least 4 hrs to be able to tackle any hypotension that ensued.

The mixture was then injected into the epidural space. No X-ray control or contrast medium was used.

Types of Outcome Measures

Patient centered outcomes analyzing a) Proportion of patients who recovered according to self, clinicians assessment or both b) Proportion of patients who had improvement or resolution of pain c) Proportion of patients who had an improvement in function measured on the SF 36 quality of life scale, and d) the rate of subsequent back surgery were used.

Measures of Objective physical impairment

SLRT (Straight Leg Raising Test), alteration in neurological status and motor/sensory function were assessed. A physical index scoring system was devised where in a single point was given if low back ache, radiculopathy, paresthesia’s, bowel, bladder symptoms, limitation of activities of daily living were present and zero points given if absent. In SLRT 4 points were given if SLRT was<10 degrees, 3 points if 10-30, 2 points if 30-60, 1 point from 60-80, 0 if >80. In power if power of a muscle group of the lower limb was 5/5, 0 points were given if 4/5,1 point given, 3/5, 2 points given, 2/5, 3 points given, 1/5, 4 points given, 0/5, 5 points given. Sensory disturbance if present was given a score of 1, if absent 0. A total score was calculated and change over 4 follow ups calculated and percentage of improvement from baseline compared with percentage of improvement in the

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VAS and pain component of SF36 scales. All patients underwent discectomy by the fenestration method.

Ethics

The procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional or regional) and with the Helsinki Declaration of 1975, as revised in 2000. Ethical clearance was taken from the St John’s Medical College Ethical Committee before the commencement of the study.

Statistical methods

Data was analyzed using SPSS verison17 software. Results are reported using mean and SD, numbers and percentages. Independent ‘t’ test was used to assess the significant difference between the ESI and discectomy group at baseline. Repeated Measures of ANOVA was used to assess the effect of intervention on reduction in the pain level over time. Spearman’s rank correlation was used to find the correlation between the VAS, SF scale at baseline and endpoint with Physical index score. Percentage change in VAS, SF pain scale and physical index score was also calculated from baseline to endpoint and comparison was done using spearman’s rank correlation. Probability value less than 5% was considered as statistically significant.

RESULTS AND DISCUSSIONOf the 51 patients 27 underwent epidural steroid injection

and 24 fenestration discectomy, before treatment 2 weeks after, 1 month and 6 months after treatment, the visual analogue scale was consistently high in both the ESI and discectomy groups on baseline measurement (ESI 63.3±22.8 versus 70.8±21.2), this progressively reduced on follow up and reduced to almost half in both groups at 6 months (ESI 27±29.9 versus 35.8±37.4) at 6months. This was statistically significant improvement in pain but there was no difference between both groups (Table1).

The SF 36 scores showed a consistent improvement from baseline scores to scores at 6 months. The maximum scores recorded in physical functioning (ESI 77.5±24.3, Discectomy 69.8±26.8), emotional (ESI 72.6±17.2, Discectomy 72.6±18.9) and social functioning (ESI 85.8±22.6, Discectomy 86.3±23.9) (Table1).

Maximum improvement was seen in physical functioning (32.5 in ESI and 34 in discectomy) and pain (30.3 in ESI and 29.6 in discectomy) (Table 1).

There was a statistically significant change in 6 month physical function scores compared to the change in VAS and SF 36 scores with a co relation of 0.41 with VAS and 0.613 with SF 36; this however was not statistically significant with pre-operative scores in all three systems (Table 2).

Though the pain improved in 50 patients, one patient had deterioration in pain and developed progression of neurological deficits. In view of this patient underwent emergency fenestration discectomy three weeks after epidural steroid injection. The patient improved symptomatically post operatively, but motor power in L5 segment had not improved at 6 months follow up.

All the other patients showed varying levels of improvement

Evaluation Epidural Steroid Injection Discectomy P value

Visual Analogue Scale

<.0001 0.998

Baseline 63.3±22.8 70.8±21.2

Follow up 1 43.8±14.9 52.5±20.2

Follow up 2 34.0±20.2 41.8±27.9

Follow up 3 27±29.9 35.8±37.4

Physical Functioning

<.0010.716

Baseline 45±24 35.8±22.5

Follow up 1 64.5±17.8 50.3±25.6

Follow up 2 72±23.1 64.8±22.8

Follow up 3 77.5±24.3 69.8±26.8

Energy <.0010.929

Baseline 44.4±15.2 43.0±17.4

Follow up 1 50.8±14.5 50.5±12.9

Follow up 2 59.0±15.2 56.3±16.2

Follow up 3 60.3±22.1 60.8±17.2

Emotional <.0010.206

Baseline 55.5±18.3 61.4±16.3

Follow up 1 63.3±16.1 70.6±14.6

Follow up 2 71.3±14.2 71.5±13.8

Follow up 3 72.6±17.2 72.6±18.9

Social Functioning

0.2340.629

Baseline 80±27.9 80±29.9

Follow up 1 88.1±18.4 81.3±25.5

Follow up 2 85.8±20.2 86.3±21.0

Follow up 3 85.8±22.6 86.3±23.9

Pain <.0010.718

Baseline 37.0±18.1 36.4±17.1

Follow up 1 50.8±26.5 47.6±17.0

Follow up 2 61.8±18.3 54.5±12.2

Follow up 3 67.3±27.2 66.0±21.8

General Health <.0010.572

Baseline 50.8±26.5 59.3±18.4

Follow up 1 63.0±21.5 66.0±18.0

Follow up2 63.8±19.9 70.0±18.9

Follow up 3 66.1±22.7 68.8±16.4

Table 1: SF 36 and VAS scale changes over four follow ups in discectomy and ESI groups.

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in pain. Seven patients in the fenestration discectomy group had neurological deficits. Three had Grade 3 motor and sensory deficits in the L5 nerve root, two had Grade 3 MRC (Medical Research Council), and two had Grade 4 MRC L4 nerve root motor and sensory deficits. After fenestration discectomy four out of seven had complete recovery of neurological deficits and three had partial sensory recovery at six months follow up. In the epidural steroid group four patients had Grade 4 MRC L5 nerve root motor and sensory deficits. All four had partial sensory deficit recovery ad no motor deficit recovery at six months follow up.

On comparing the physical index score with SF 36 and VAS, the end line and percentage change in physical index score with VAS and SF 36 was statistically significant with a high correlation.

The ideal treatment for various types of disc herniation has posed a challenge to many spine surgeons and choosing the most appropriate and effective mode of therapy in each type is of paramount importance.

Although Lumbar discectomy is a common operation, valid indications for operative treatment are still elusive and the results of such treatment are inconsistent [8].

Epidural steroid has been proven to be an effective method to alleviate radicular symptoms in patients with lumbar disc herniation and has been shown to be effective up to 12-27 months in alleviating these symptoms though it may not be a permanent solution to the problem [6].

Although Lumbar laminectomy is one of the common operations for a herniated lumbar disc, laminectomy has its inherent draw backs of a prolonged surgical time, more blood loss and a delayed convalescence period. The post-operative complication (e.g. arachnoiditis and adhesions) are found to be more when laminectomy is used as a procedure. To add to this it is also found to jeopardize the mechanical stability of the spine. In such a situation a surgical procedure which is less damaging to the stability of the spine, has a shorter surgical time, less blood loss, lesser incidence of post-operative complications and ultimately has a shorter convalescence period would be more beneficial.

Discectomy by fenestration method is exactly that kind of a surgical procedure wherein only the inter-laminar space is utilized without removal of any part of the lamina, the cord is exposed retracted and the discectomy carried out [7].

Epidural Steroid is a low cost alternative to fenestration discectomy as a temporary measure to reduce symptoms. It also does away with the complications of surgery and is a much faster procedure though it has limitations with regard to its duration of effectiveness.

In a study comparing epidural steroid versus discectomy at The Midwest Spinal Institute, one hundred and sixty-nine patients with a large herniation of the lumbar nucleus pulposus (a herniation of >25% of the cross-sectional area of the spinal canal) were followed over a three-year period. One hundred patients who had no improvement after a minimum of six weeks of noninvasive treatment were enrolled in a prospective, non-blinded study and were randomly assigned to receive either epidural steroid injection or discectomy. Evaluation was performed with the use of outcomes scales and neurological examination.

Epidural steroid injection was not as effective as discectomy in reducing symptoms and disability associated with a large herniation of the lumbar disc. However, epidural steroid injection did have a role: it was found to be effective for up to three years by nearly one-half of the patients who had not had improvement with six or more weeks of noninvasive care [9].

In the SPORT study a randomized clinical trial enrolling patients between 2000 and 2004 from 13 specialized spine clinics in the US from 11 states with 501 enrolments with similar inclusion criteria as our study comparing non operative and operative treatments of lumbar disc herniation over 2 years yielded the following results on the SF36 scales : As-treated analyses based on treatment received were performed with adjustments for the time of surgery and factors affecting treatment crossover and missing data. These yielded far different results than the intent-to-treat analysis, with strong, statistically significant advantages seen for surgery at all follow-up times through 2 years [10]. In our study both groups showed significant improvement in physical scores as well as quality of life.

There was one patient in our study where we shifted to fenestration discectomy after epidural steroid injection after six months due to the persistence of symptoms and affection of quality of life with progression of neurological deficits.

Our results reflect that both treatment modalities are as effective at six months follow up which co relate well with significantly improved physical function scores at the end of six months. This could be related to the fact that most of the initial pain in disc herniation is related to the inflammation around the disc that the epidural steroid effectively reduces due to its anti-inflammatory effect. Our hypothesis is that the patient is usually aware of this and tends to reduce activity levels for a period of time. This subsequently prevents a recurrence of symptoms. It would however be interesting to note whether the symptoms recur when they resume full pre symptom activities. This time period could be variable depending on the patient.

The improvement in quality of life co-related very well with an improvement in physical function scores that further establishes that both modalities are excellent at improving physical symptoms as well as quality of life.

Base line Correlation r2 P value

Physical index score with VAS 0.22 0.172

Physical index score with SF 36 pain -0.22 0.167

End line Physical index score with VAS 0.41 <0.01

Physical index score with SF36 pain 0.613 <0.001Base linePhysical index score percentage change with VAS 0.406 <0.01

Physical index score change with SF36 0.478 <0.01

Table 2: Physical Index Score variation with SF 36 and VAS scales

All components of the SF36 score improved post intervention in both groups and there was no significant difference between the two groups.

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Mhaskar VA, Pai SN (2015) Epidural Steroid Injection: A Convenient Short Term Alternative to Fenestration Discectomy in Lumbar Disc Herniation. JSM Neurosurg Spine 3(2): 1057.

Cite this article

On feedback from patients the gradation of question e.g.: most of the time, some of the time, a little of the time etc. were difficult to categorize with no definitive guidelines for the same which at times would confuse the patients.

The VAS was difficult to compare with the SF 36 as it was more relative and based on a single opinion not taking various factors affecting the pain component. This was relatively less reproducible as compared to the pain component of the SF36 and responses varied slightly on questioning at various times.

The SF36 also took a very long time to administer varying between 20 and 25 minutes which again made the patients tired while responding with varying concentration levels while filling up the questionnaire.

CONCLUSIONThere was significant improvement in quality of life of

life of patients treated with both epidural steroid injection and fenestration discectomy with no statistically significant difference between the two groups at all intervals till 6 weeks.

There was no significant difference between the VAS and pain component of SF 36 scale in measuring improvement in pain. The improvement in quality of life co related with the improvement in physical signs and symptoms. There was no significant difference in results between the two sexes.

Epidural steroid is a good low cost alternative to fenestration discectomy for temporary relief of symptoms of lumbar disc herniation especially radiculopathy.

SF 36 is a useful questionnaire to evaluate quality of life in an Indian setting though some aspects of it are not applicable to the rural population especially pertaining to physical functioning.

ACKNOWLEDGEMENTSI would like to thank my statistician Mrs Sumitra, my wife Dr

Parul Maheshwari, my parents Dr Rita and Dr Arun Mhaskar for

their help and support. I would also like to thank the Department of Orthopaedics SJMCH, Mrs. Sumithra my statistician my inspiration Dr J Maheshwari.

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