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CERTIFICATE

This is to certify that this dissertation titled “ FUNCTIONAL OUTCOME OF LUMBAR FENESTRATION AND DISCECTOMY IN PATIENTS WITH LUMBAR INTERVERTEBRAL DISC PROLAPSE ”, which is being submitted for M.S ORTHOPAEDICS, is a bonafide work of Dr.KARTHIK.A, Post graduate student of the Department of Orthopaedics, Govt. Mohan Kumaramangalam Medical College Hospital, Salem, during the academic year 2017 -2020.

PROF. DR. K. THIRUMAL BABU, M.D., D.M., Dean, Govt Mohan Kumaramangalam Medical College, Salem.

CERTIFICATE

This is to certify that this dissertation titled “ FUNCTIONAL OUTCOME OF LUMBAR FENESTRATION AND DISCECTOMY IN PATIENTS WITH LUMBAR INTERVERTEBRAL DISC PROLAPSE ”, which is being submitted for M.S.Orthopaedics, is a bonafide work done by Dr.KARTHIK.A, Post graduate student of the Department of Orthopaedics, Govt. Mohan Kumaramangalam Medical College Hospital, Salem.

He has completed the necessary period of stay in the department and has fulfilled the condition required for submission of this thesis according to university regulations. The study was undertaken by the candidate himself and the observations recorded have been periodically checked by us.

Recommended and Forwarded

Prof. C. KAMALANATHAN, M.S.ORTHO., D.ORTHO., DNB., Professor and Head of the Department,

Department of Orthopaedics, Govt. Mohan Kumaramangalam Medical College Hospital,

Salem.

CERTIFICATE

This is to certify that this dissertation titled “ FUNCTIONAL OUTCOME OF LUMBAR FENESTRATION AND DISCECTOMY IN PATIENTS WITH LUMBAR INTERVERTEBRAL DISC PROLAPSE ”, which is being submitted for M.S.Orthopaedics is done by Dr.KARTHIK.A, Post graduate student of the Department of Orthopaedics, Govt Mohan Kumaramangalam Medical College Hospital, Salem under my guidance.

Prof.Dr. T.M.MANOHAR, M.S.ORTHO., Professor of Orthopaedics, Department of Orthopaedics, Govt. Mohan Kumaramangalam Medical College Hospital, Salem.

DECLARATION

I, Dr.KARTHIK.A, solemnly declare that this dissertation titled

“FUNCTIONAL OUTCOME OF LUMBAR FENESTRATION AND DISCECTOMY IN PATIENTS WITH LUMBAR INTERVERTEBRAL DISC PROLAPSE”, is a bonafide work done by me at Govt. Mohan Kumaramangalam Medical College, Salem from November 2017 onwards under the guidance and supervision of Prof. C.KAMALANATHAN, M.S.ORTHO., D.ORTHO., Professor and Head of the Department, Department of Orthopaedics, Govt Mohan Kumaramangalam Medical College, Salem.

I have not submitted this dissertation to any other university for the award of any degree or diploma previously. This dissertation is submitted to the Tamilnadu Dr. M.G.R. Medical University, Chennai towards partial fulfilment of the rules and regulations for the award of M.S Degree in ORTHOPAEDIC SURGERY (BRANCH – II)

PLACE :

DATE : Dr.KARTHIK.A

CERTIFICATE - II

This is to certify that this dissertation work titled “FUNCTIONAL OUTCOME OF LUMBAR FENESTRATION AND DISCECTOMY IN PATIENTS WITH LUMBAR INTERVERTEBRAL DISC PROLAPSE”, by the candidate Dr.KARTHIK.A, with registration Number 221712355 for the award of M.S., DEGREE in the branch of ORTHOPAEDIC SURGERY BRANCH II.

I personally verified the urkund.com website for the purpose of plagiarism Check.

I found that the uploaded thesis file contains from introduction to conclusion pages and result shows 11 percentage of plagiarism in the dissertation.

Guide & Supervisor sign with Seal

ACKNOWLEDGEMENT

I am obliged to record my immense gratitude to Prof. Dr. K. THIRUMAL BABU, M.D., DM., Dean, Govt. Mohan

Kumaramangalam Medical College Hospital, for providing all the facilities to conduct the study.

I take this opportunity to express my deep sense of gratitude and heartfelt thanks to Prof. C.KAMALANATHAN, M.S.Ortho., D.Ortho., Head Of the Department of Orthopaedics, Govt. Mohan Kumaramangalam Medical College Hospital for permitting me to use the clinical materials and for his valuable advice and constant encouragement in bringing out this dissertation. He has been the pillar of discipline, courage and immense kindness and who was instrumental in guiding me throughout the course of this thesis. I consider myself fortunate and privileged to work under his affectionate guidance, excellent supervision and sustained support.

I am extremely thankful to Prof. T.M.MANOHAR, M.S.Ortho., Professor of Orthopaedics, who has been a constant source of inspiration to me and whose excellent guidance and for his valuable insights regarding this study.

I owe a great deal of respect and gratitude to Professor and unit heads Prof. R.T. PARTHASARATHY, M.S.Ortho., Prof. A. D. SAMPATH KUMAR,

M.S.Ortho., for their scholarly suggestions and all around encouragement.

I also express my sincere thanks to my unit Assistant Professors and co guide DR.L.KUMAR, M.S.ORTHO., D.ORTHO.,

DR.S.SELVAKUMAR, M.S.ORTHO., DR.T.SATISH KUMAR, D.ORTHO., DNB ORTHO., DR. S. MOHAN KUMAR, M.S.ORTHO., D.ORTHO., for their suggestion and constant advice during my study.

I also thank the Assistant Professors DR. S. KUMAR, M.S.ORTHO.,

DR.N.KARTHIKEYAN,M.S.ORTHO.,DR.P.RADHAKRISHNAN, M.S., DR.S.JAWAHAR, M.S. ORTHO., DR.P.ARUNANAND, M.S.ORTHO., DR.T.SENTHIL KUMAR, D.ORTHO., DR.P.CHINNADURAI, D.ORTHO.,

DR. S.SYED NASER, D.ORTHO., M.S.ORTHO., D.N.B ORTHO., DR. P.SIVAKUMAR, M.S.ORTHO., DR.R.N.SURESH KUMAR, M.S.

ORTHO., for their valuable suggestions.

I am also grateful to all anaesthesiologists, my fellow post graduates, all paramedical staffs for rendering timely help to complete my study. Last but not the least I am profoundly grateful to all the patients for their co-operation and participation in this study.

TABLE OF CONTENTS

SL.NO. CONTENTS PAGE NO

1. INTRODUCTION 1

2. OBJECTIVES 3

3. REVIEW OF LITERATURE 4

4. ANATOMY 9

5. PATHOLOGY 26

6. DIAGNOSTIC TESTS 36

7. INVESTIGATIONS 38

8. TREATMENT 41

9. MATERIALS AND METHODS 47

10. RESULTS AND ANALYSIS 56

11. DISCUSSION 69

12. SUMMARY 75

13. CONCLUSION 76

14. CASE ILLUSTRATIONS 78

15. BIBLIOGRAPHY 88

16. ANNEXURE 94

17. MASTER CHART 103

LIST OF TABLES

SL. NO TABLES PAGE NO.

1. AGE DISTRIBUTION 56

2. SEX DISTRIBUTION 57

3. OCCUPATION 58

4. SYMPTOMS AND SIGNS 60

5. SIDE INVOLVEMENT 61

6. LEVEL OF DISC HERNIATION 62

7. PRE OP JOA SCORE 64

8. POST OP JOA SCORE 65

9. COMPLICATIONS 66 10. NEUROLOGICAL DEFICIT AND IMPROVENT 66

11. JOAS FUNCTIONAL OUTCOME 67

LIST OF CHARTS

SL. NO CHARTS PAGE NO.

1 AGE DISTRIBUTION 56

2 SEX DISTRIBUTION 57

3 OCCUPATION 58

4 SYMPTOMS AND SIGNS 60

5 SIDE INVOLVEMENT 61

6 LEVEL OF DISC HERNIATION 63

7 PRE OP JOA SCORE 64

8 POST OP JOA SCORE 65

9 JOAS FUNCTIONAL OUTCOME 68

LIST OF ABBREVIATIONS USED

CT : COMPUTED TOMOGRAPHY

IVDP : INTERVERTEBRAL DISC PROLAPSE IFT : INTERFERENTIAL THERAPY

MRI : MAGNETIC RESONANCE IMAGING

LS : LUMBOSACRAL

JOAS : JAPANESE ORTHOPAEDIC ASSOCIATION SCORE

SWD : SHORT WAVE DIATHERMY

TENS : TRANSCUTANEOUS ELECTRIC NERVE STIMULATION

ABSTRACT

AIM : To study the functional outcome of lumbar fenestration discectomy in patients with lumbar intervertebral disc prolapse.

MATERIALS AND METHODS : This is a prospective study in patients with lumbar intervertebral disc prolapse in the age group of 20 –70 years admitted in Government Mohan Kumaramangalam Medical College and Hospital, Salem during the period from November 2017 to October 2019. The cases were evaluated using Japanese Orthopaedic Association Score. Those patients who do not responding to conservative treatment are evaluated and operated using the technique of lumbar fenestration discectomy.

DISCUSSION : The mean age group of patients in our study was 42.9 years with a male preponderance. Thirty patients were included in the study. L4-L5 disc was the common level of disc prolapse. Sciatica was the most common symptom.

One patient has excellent outcome, 24 patients have good outcome, three patients have fair outcome and two patients have poor outcome.

RESULTS : Lumbar fenestration discectomy has proved to give good results when combined with proper patient selection and post operative physiotherapy. The results obtained are similar to results from technically demanding procedures like microdiscectomy.

INTRODUCTION

Back pain accounts for 2% of patients in general outpatient clinic, and 60%

of orthopaedic outpatient census, the commonest cause of low back pain being lumbar disc prolapse. 80% people experience low backache at some point of their lifetime.¹Most important cause for loss of decreased productivity in middle age and young individuals. Nerve root decompression by surgical intervention is the goal.

Sciatica caused by nucleus pulposus herniation of disc is the commonest symptom of patients presenting to outpatient clinic. With an annual incidence of 1% - 5%, lumbar disc prolapse has a favourable outcome. MRI prevalence accounts for 30% but clinical incidence with low back ache accounts for only 1-2%. Seventy percentage patients have resolution of symptoms with nonoperative management.²

The natural course of lumbar disc prolapse shows that the disc may reduce in size or disappear within duration of weeks to months. Macrophages phagocyte extruded and herniated discs but in contained herniations, nucleus pulposus dehydrate and result in reduction of disc size. Overall the long term benefits of surgery versus non operative treatment are still unclear.³

Progressing neurological deficit and cauda equina syndrome are absolute indications for surgery. Surgical management of those patients with severe low back pain without progressing neurological deficit remains the topic of debate.

Eventhough surgery is planned for such patients the exact timing of surgical intervention still remains contradictory.

Many studies have shown good results with fenestration discectomy ranging from 46-97%.^4-6 Many surgical techniques have been developed since then.

Laminectomy, hemilaminectomy, fenestration discectomy, microscopic discectomy and endoscopic discectomy are the various techniques.

Mixter and Barr first showed that laminectomy and decompression could relieve symptoms in patients with low back ache in 1934 and from then open discectomy has become a gold standard approach for lumbar disc prolapsed.²

This was later enhanced by Semmes. He described hemilaminectomy and retraction of the dural sac with disc excision which was later on described as the

“Classical discectomy technique”. Many minimally invasive techniques were developed since then. Yasargil in 1977 performed the first microscopic discectomy.

Mayer and Brock in 1993 and Smith and Foley in 1997 described the technique of endoscopic discectomy which demonstrated decreased soft tissue manipulation, time of surgery, blood loss, and hospital stay with early recovery.

The aim of our study is to analyse the functional outcome of lumbar disc prolapse managed by fenestration discectomy and the scoring used is Japanese Orthopaedic Association low back ache scoring system. It consists of a total score of 29 subclassified into four categories

1) Patient symptoms 2) Clinical signs

3) Ability to do day to day activities 4) Bladder sensation

OBJECTIVES

To analyse the functional outcome of lumbar fenestration discectomy in patients with lumbar intervertebral disc prolapse.

REVIEW OF LITERATURE

Low back ache has been a disease known to humankind since a very long time and records of it were found in books written by Hippocrates. But the relation between leg pain and lumbar disc prolapse was found only in the early 20^th century.

Symptoms of sciatica were first observed by Aurelinus in the early 15^th century. In 1543, the intervertebral disc was first discoverd by Andreas Vesalius. In 18^th century, Contugnio first related symptoms of leg pain to sciatic nerve.

In 1881, Laseague sign was first described by Frost and named it Laseague sign in honour of his teacher. Von Luskha, Oppenheim and Krause described disc rupture individually in consequent years.

In the year 1909, Krause and Oppenheim performed the first surgical excision of intervertebral disc and they described it unknowingly as enchondroma of the spine.

In 1911, Goldwaithe made the observation of L5-S1 disc prolapse with annulus fibrosus tear and the same causing compression of nerve roots and causing symptoms of cauda equine and sciatica.

In 1928, Schmorl, a pathologist observed Schmorl nodes, which he described as intravertebral extension of disc. Many considered disc hernia as a neoplasm in those days and considered it be a enchondroma .

The usefulness of surgical excision of disc in the betterment of patients with low back ache and sciatica was first published in the New England journal of

medicine by Mixtard and Barr after their observation in 58 patients. Total laminectomy and disc excision by transdural approach was the commonly performed procedure.

It was Semmes who first performed the modern day practise of disc excision through subtotal laminectomy and dural retraction. This is the most commonly performed procedure even today for disc excision.²

Lyman smith coined the term chemonucleolysis by injecting chymopapain and performing enzymatic dissolution of the disc back in 1963.⁷ Many kept attributing sciatic symptoms to disc prolapsed and this led Macnab to term the events as “dynasty of the disc”.

In 1974, Naylor postulated that conservative management should not be continued for patients who do not show improvement for a long duration of time based on the long term observation he made in 204 patients. Patients with central disc prolapse who present with bladder and bowel disturbances are definitive indications for disc excision. The functional outcome is affected by the duration of symptoms and the degeneration of the disc at the time of presentation. 79%

excellent results were observed in his study.

In 1980 Shankaran and Sharma published their study involving 117 patients with disc prolapse of which 57 were treated surgically. 82% good results were obtained in this study. Myelography was used for the localisation of the disc level.⁹

In 1983, Kambin and Gelman postulated percutaneous method of disc excision.¹⁰ In the same year, Weber compared patients managed by conservative and surgical management and found that patients managed surgically by disc excision showed better outcome in the first year in terms of pain reduction.¹¹ Both the groups had good neurological recovery and the long term results were comparable between the two groups.

The importance of CT in disc herniations was found by John Goldersky in 1984.¹³ He observed that CT scan aided in diagnosing disc prolapse levels and prevented unnecessary exploration of spinal canal.

Micheal Modic in 1984 saw MRI was the most successful tool for the surgeon compared to CT, myelogram and radiographs. All the structures of disc namely nucleus annulosus, fibrosus, the hydration of the disc, the level of prolapse and stage were all clearly shown by MRI.¹⁴

In 1985, Nagi used the technique of fenestration discectomy and found 91.9% excellent results.¹⁵

In 1986, Ebeling et al published results of his microsurgical discectomy in his study on 485 patients and found 39% excellent, 34% good, 19% satisfactory and 9% poor results and found better outcome with microsurgical discectomy than with routine fenestration discectomy.¹⁷

In 1987, Matti Hurme et al found that surgical outcome was good if patients were operated 2 months from the onset of symptoms and social and psychological factors played a very vital role in the outcome.¹⁹

In 1987, Jeffrey et al did a prospective study with 100 patients who underwent surgical discectomy and found that surgical intervention with physiotherapy produced better outcome.²⁰

In 1989, Gupta et al found 86% good to excellent results and 4 patients had developed failed back syndrome in his study.²⁴ In 1990, Spengler et al devised a scoring system to select patients for discectomy and found better outcomes in those patients selected after preoperative scoring.²⁵

In 1992, Pappas et al found that patients who had lifestyle modifications and professionals had better outcome than those who continued same sternous activity in his study involving 654 patients.⁵

In 1993, Tullberg found no significant difference in those patients treated by standard discectomy and microscopic discectomy. Mochodo et al found that patients treated by open discectomy had better functional outcome than those treated by percutaneous nucleotomy.²⁸

In 1994, Davis found 89% good results in patients with surgical discectomy.

6% had recurrence and 4% developed failed back syndrome.⁶

In 1995, Erico et al found open discectomy as the gold standard for the treatment of disc excision and it was associated with minimal recurrence and less complications.

In 1996, Mcculloshfound that patient selection was the most determining factor in surgical outcome of disc surgery. In 1988 Wang et al found that dural tears had no long term disastrous outcome based on his study on 88 patients.³⁰

In 2003, Morgan et al found that open discectomy had 7.9% recurrence rates and more severe conservative management with life style modifications will be needed in these cases.³³ Endoscopic spine surgery is a rapidly developing field due to developments in scope design, techniques and instrumentation where spine is approached through the Kambin’s triangular space.

Microendoscopic spine surgery combining the technique of endoscope and microscopic surgery is another rapidly evolving technique for minimally accessing the disc. However it is a time consuming surgery with steep learning curve.

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FIG.3 VERTEBRAL COLUMN

Intervertebral foramen: This is formed by the superior and inferior articular processes which are located superior and inferior to the pedicles respectively. The inferior articular process is the most prominent. It forms the intervertebral foramen together with the superior process, through which spinal nerves exit the spinal canal.³⁷

The intervertebral discs: These are discoid fibro-cartilage substance, which possess elastic properties that absorbs and disperses loads on the spinal column and allows for smooth movement of the spine. 25% of the length of spine is contributed by the intervertebral disc and this is increased to 33% in the lumbar region. There are 23 discs in total but absent at the atlanto axial articulation. Discs are thinnest in the dorsal spine and thickest in the lumbar region.

Each disc consists of three parts. ³⁹ 1) Nucleus pulposus :

Being placed little posterior to the central axis of the vertebrae, it is made up of glistening white, mucoid semi fluid material which is composed of glycosaminoglycans, water and salts. Few multinucleated notochordal cells are also present at birth which become obsolete in the first decade, these are later replaced by mucoid fibrocartilage material obtained from the annulus fibrosus and the hyaline cartilaginous end plates throughout life.

With these changes the nucleus pulposus becomes amorphous and loses its colour. Also its hydrophilic properties decline which its obtains through the

proteins. Microscopic structure shows fine fibrillar structure with clear stroma resembling connective tissue, mucin and fibroblastic cartilage and rarely notochordal cells. The borders slowly gradually merge into the annulus fibrosus and becomes indistinct.

The rigidity of the nucleus pulposus is due to the high osmotic pressure of the disc which draws fluid from the spongiosa of the vertebrae. The nucleus transmits the pressure against the cartilage plate and annulus fibrosus due to its non compressible nature. This makes a person one centimetre taller in the morning than in the evening due to changes in the water composition of disc.

2) Annulus fibrosus :

It has a thin outer collagenous zone and a wider inner fibrocartilagenous zone made up of numerous concentric rings of fibrocartilogenous tissue. These fibres are linked to each other through diagonal fibres and radial fibres. Sharpey’s fibres connect the lamellar rings to the epiphyseal end plates. In the periphery the lamellae simply overlap each other. Posteriorly they interlink in a complex manner.

Posteriorly the fibres are vertical leading to the tendency for pulposus to herniate.

The rest of the fibres are arranged oblique to the vertebra and hence limit rotational movements of the spine.

3) Cartilaginous end plates :

This contains layers of hyaline cartilage, the ends of which are calcified and in direct contact with the trabeculae of the vertebral bodies. This aids in nutritional

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LUMB BAR VER RTEBRA A AND IN NTERVE ERTEBR RAL DIS SCS

APPLIED ANATOMY

Intervertebral discs contribute to 20% of the vertebral height overall. In young individuals the discs are so strong that trauma weakens vertebral bones first.

After the second decade, degenerative changes begin and result in nercrosis and sequestration of the pulposus, weakness of the annulus fibrosus layer. Trivial trauma causes derangement of the pulposus layer with peripheral displacement which bulges through the annulus fibrosus in the anatomically weaker posterolateral region.

Ligaments of the spine: The anterior and posterior longitudinal ligaments span the entire length of the spine and are named depending on their position to the vertebral bodies.

1. The anterior longitudinal ligament :

This begins cranially from the base of the skull and extends caudally to attach into the ventral sacral vertebra. Through the entire length, this gets attached to the vertebral bodies and intervertebral discs.

2. The posterior longitudinal ligament :

Lying posterior to the vertebral bodies this lines the spinal canal ventrally.

Like the anterior longitudinal ligament, it is attached along its length to the vertebral bodies and intervertebral discs.

3. The ligamentam flava :

This holds the consecutive lamina in position by blending anteriorly to the superior lamina and posteriorly to the inferior lamina and limits the separation of lamina during flexion and helps in extension of the spine.

4. The supraspinous ligament :

This begins from the seventh cervical vertebra and ends in the sacrum connecting the tips of all the spinous processes.

5. The interspinous ligament :

This begins from the ligamentum flavum anteriorly and extends till the supraspinous ligament posteriorly.

LIIGAMENTTS OF LUUMBAR SPPINE

B

BLOOD SSUPPLY OOF THE VVERTEBRRAL CANNAL

Motion segment of spine:

The functional unit of the spinal column is called the motion segment of the spinal canal. This is composed of two adjacent vertebral bodies, the facet joint formed by superior and inferior articular processes, the intervertebral disc between them and the surrounding soft tissue structures. The intervertebral disc and the facet joints (one on each side of the midline) permits motion in coronal, sagittal and rotational movements.

Farfan showed that disc protrusion leads to increased tension over the roots in the posterolateral corner. Posterior longitudinal ligament is also weak in the posterolateral corner. Weak PLL and increased tension in the posterolateral corner eventually leads to nucleus pulposus tearing the lamina of annulosus and protruding into the canal in the posterolateral region. The exiting nerve root is usually present in this region leading to exiting nerve root compression effects. The disc may sometimes protrude into the extraforaminal space and produce proximal nerve root compression.

Blood supply:

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Intervertebral disc prolapse incidence:

Hult reported a progressive increase in disc prolapsed with age and mounts to about 100% by the age of 59 in manual labourers. Kelsey found that disc disease incidence was lowest in white collar professionals and highest in manual labourers.

Pathogenesis of disc degenertion and Natural history of disc disease

Kirkaldy – Willis and Hill studied the natural course of disc disease by their cinical studies. He postulated that all spines degenerate over time and all our treatment methods never cure the disease.

They described the degenerative disc disease in three stages.

1. Stage of dysfunction 2. Stage of instability 3. Stage of stabilization

At any given time, different spinal segments may be in different stages of the disease. The facet joint and disc of the same level may be in different phases of the disease.

1) Stage of dysfunction:

It is usually found in the middle and young ages. Circumferential and radial tears in the annulosus layer along with facet joint synovitis are its features. With repetitive minor trauma and ageing process, nutrition to the disc is reduced causing failure to synthesise the lost proteoglycans. All these leads to disturbed water

exchange and reduced collagen synthesis in the discs. All these lead to annular tears due to loss of nuclear integrity. Symptoms include pain, muscular spasm and reduced mobility.

2) Stage of instability:

Occurs in 35 to 70 year old patients and causes disc disruption with progeressive resorption, facet joints degenerative changes with stretching of the capsule, joint subluxation and erosion. As the disease progresses, fragmentation of the pulposus layer occurs, the disc loses its structural integrity due to break in the hyaline end plates and annular tears. Exagerrated sagittal and coronal plane mobility finally results.

3) Stage of stabilization:

In this stage, there occurs facet joint hypertrophy leading to decreased mobility and ankyosis of the joints and stiffness of vertebral segments. Disc height reduction leads to decreased angular movements. Disc bulge and protrusion are natural events of the disease but disc extrusion needs some associated trauma.

Miller, Schmatz and Schultz noticed that degeneration progresses with age and males were more susceptible than females. L4-L5 followed by L3-L4 are the levels of greatest incidence in their study. The course of disc disease includes periods of waxing and waning and pain free and painful episodes alternating.

The staging of the lowback ache depending on the duration is as follows

 Acute (less than 6 weeks)

 Subacute ( 6 -12 weeks)

 Chronic (greater than 12 weeks)

 Recurrent

PATHOLOGY

Radial tears in the annulus fibrosus layer or the altered water content of the pulposus layer leads to loss of function of the disc per se. The pulposus begins to prolapse into the annulosus layer and this leads to loss of disc height. Later the annulosus layer becomes calcified. The nucleus contained within the annulosus by some means is named protrusion and that completely ruptured out is termed extrusion where the disc material will be found lying in the epidural space

BIOMECHANICAL FACTORS AND BIOCHEMICAL FACTORS ASSOCIATED WITH DISC PROTRUSION

A supine patient of weight 70 kilograms sustains a pressure of 20 kilograms on his disc, 100 kilograms while standing and 270 kilograms while sitting on the same disc with a weight of 20 kilograms in his hand.

Disc pressures and myoelectric activity are highest when sitting with a slight bend without support and lowest when sitting straight with support. Disc disease causes:

1. Glycosaminoglycans concenteration reduction of the disc 2. Fissuring and deposition of collagen

3. Increase in low molecular weight proteoglycans

TYPES OF DISC PROLAPSE

1. Intrapongi-nuclear herniation:

Pulposus layer decussates into the annulosus but the outer rim of annulosus is intact, shape and integrity is maintained.

2. Protrusion:

Annular layer develops a small bulge into the canal.

3. Extrusion:

The annulus layer is completely ruptured but the protruded pulposus layer is still in contact with the main nucleus

4. Sequestration:

The nuclear material lies freely in the canal space and is totally cut off from the native nucleus.⁴⁵

Depending on the site of disc prolapsed disc protrusion may be classified into:

A. Central type- rare

B. Paramedian type-one intradural and one extradural nerve roots are affected.

C. Lateral type- both the affected nerve roots are extradural.

The disc normally protrudes lateral to PLL. Based on the size of the prolapse the nerve root may be compressed either

1) backwards and medially 2) backwards and laterally

The commonest site of disc protrusion is lateral to the posterior longitudinal ligament . The root may be compressed backwards and medially or backwards and laterally depending on the size of the disc bulge.

Intermittent herniation of Falconer or Concealed disc of Dandy is type of disc herniation which is not obvious on the operating table in flexion position due to the softness of the fibrosus layer. Hyperextension of the spine reproduces the bulge.³

A

C)

A) BULGE

EXTRUSI

STAGES

E

ION

OF DISC PROLAP

B)

D) S PSE

) PROTRU

SEQUEST

USION

TRATION

INCIDENCE

Hult showed that 80% of people suffer from low back ache at some point of time in their lives.

Svenson and Anderson showed life time incidence of 61% and prevalence of 31% in their study involving men in the age group of 40-47 years.. In women between the age group of 38 to 64 years the incidence was 66% and prevalence is 35%.

The incidence of lumbar discectomy in the USA is approximately 70/100,000 patients as shown by Kave. The average age at which a person undergoes spine surgery is 38 years and twice the number of men are affected in comparison to women.⁴⁶

The age incidence of lumbar disc prolapse is fairly evenly distributed in the 3 decades between 20 and 50 years.³⁹

Frymoyer in his study showed that the average age of patients undergoing lumbar discectomy is 42 years and the lifetimeincidence is 42% and the nerve root involvement is only in 3% patients. ⁴⁴

Horal noted that 35 percent of patients with low back pain will at some time develop sciatica. Nachemson in his study showed that 4.8% of male population and 2.5% of female population above the age of 35 years will at some time in their life experience sciatica. Hakelius showed 75 % of patients with acute lumbar radiculopathy will experience low backache.

CLINICAL FEATURES

HISTORY:

Back pain:

This is the most common presenting complaint but patients present the symptom of pain only after a history of trauma. On repeated probing, the patient reveals their symptoms being present for a long time. Most patients with degenerative disc diseases have low back pain. Pain in the lower back radiating to the lower limbs which aggravates by lifting weights, bending forwards, and trunk torsion or twisting, coughing, sneezing that relieves by rest in specified positions is the usual elaboration of pain in lumbar disc disease. Trauma is a precipitating rather than a causative factor.⁴³

Referred pain:

Pain starts in the lower back and is referred to the sacroiliac region, buttock and posterior thigh. Pain from other areas of the spine also get referred in this pattern including the facet joints, longitudinal ligaments and periosteum of the vertebrae.⁴³

These are mesodermal structures which when irritated cause referred pain to sacroiliac joint, buttocks etc. This pattern of referral is to the area- designated sclerotome, which has the same embryonic origin as the mesodermal tissues stimulated.⁴³ This is called referred pain.

Radicular pain:

Pain caused by the pressure on the inflamed nerve root by the protruding disc causes motor and /or sensory deficits along the dermatome which is usually called the radicular pain and presents below the knees. In almost all cases the radicular pain is greater than the low back ache. ⁴³

Sciatica:

The leg pain is characteristic of disc herniation and is exaggerated by valsalva maneuver and by other activities that increases the intradiscal pressure or intracranial presure. ⁴³

A. Motor and sensory symptoms:

Weakness and paraesthesia are occasional and variable and are restricted to the level of disc prolapsed. Sensory involvement is also associated to the dermatome of the nerve root

B. Cauda equina syndrome :

A high level disc prolapse or a large central prolapse can compress many roots of the cauda equine leading to cauda equine syndrome. Raaf found the incidence to be 2% while Spangfort reported 1.2%. Numbness and weakness of both legs, rectal pain, numbness in the perineum and paralysis of sphincters are all the symptoms. Overflow incontinence, difficulty in initiating micturition are all possible presentations.

Saddle anaesthesia, impotence, perianal numbness, loss of rectal tone and loss of anal reflex or diminished rectal tone are associated with severe forms of cauda equina syndrome.⁴³

C. Bladder symptoms that can arise are - total urinary retention

- chronic, long standing, partial retention - vesicular irritability, loss of desire to void.⁴³

SIGNS/ PHYSICAL EXAMINATION Inspection:

These patients have a characteristic gait with the patient flexing the hip and highly anxious to place the involved leg on the floor. There is also a loss of lumbar mobility, lumbar lordosis obliterated and paraspinal muscle spasm are seen in acute stage of disc degeneration. “Sciatic scoliosis” is a special posture where the patient bends sideways and walks.⁴³

Palpation:

Deep tenderness on spinal palpation at the level of disc degeneration with paraspinal spasm is the usual finding. Tender points in the involved myotome also occurs which represents neuromuscular junctions.

Neurological examination:

A thorough neurological examination provides evidence of nerve root compression and shows the disc degeneration and nerve root involved. L4-L5, then L5-S1 followed by L3-L4 is the usual disc incidence. Motor nerve fiber compression of the nerve root leads to wasting or atrophy of the muscle groups along with motor weakness or paraparesis with diminished or lost reflexes.

Dermatomal involvement usually follows the specific pattern, S1 radiculopathy leads to loss of sensation in lateral part of foot and sole and posterior calf. All these needs to be tested with precision.

Clinical Root Syndrome

Sensory Findings Motor Findings Deep tendon Reflex

L4 Numbness over

the anteromedial thigh and knee

Weakness and Atrophy of quadriceps.

Knee jerk absent.

L5 Numbness over

lateral leg, web of great toe.

Weakness of dorsiflexion of great toe and foot.

Usually none.

S1 Numbness over

back of calf, lateral heel, foot and toe.

Weakness of plantar flexion of foot and great toe may be affected.

Ankle jerk diminished or absent.

DIAGNOSTIC TESTS

O’connell categorised these signs as - the spinal signs

- nerve tension signs and - neurological signs Sciatic nerve tension signs:

These tests tighten the sciatic nerve and further cause compression of inflamed nerve root against a prolapsed lumbar disc.

A. Lasegue test or the straight leg raise test :

This is the most commonly done test. With this manoeuvre, the L5 and S1 nerve roots move 2 to 6 mm above the resting position in the foramen. With 35 to 70 degrees of elevation from the supine position, it was noted that tension is realized within the nerve roots contributing to the sciatic nerve. This test is performed with the patient lying supine and his head flat or on a low pillow. The test is considered positive only when leg pain or reproduction of the patients radicular pain occurs.

B. Bowstring test :

With knee in full extension patient is asked to flex the hip on the affected side till the pain feels pain. At this point the knee is flexed, which instantaneously reduces the pain. On pressing the sciatic nerve in the popliteal fossa the painful radicular symptoms restarts which indicates tension on the nerve roots.

C. Contra lateral straight leg raising test or the Well leg raising test.

D. Circumduction test :

It helps to define the relationship between the nerve root and the disc protrusion (Whether medial or lateral to nerve root).

E. Braggards sign.

F. The femoral nerve stretch test:

With the patient prone,the hip is extended with knee in 90 degrees flexion.pain is produced in the anterior aspect of thigh when the disc prolapse occurs at a higher level.⁴³

INVESTIGATIONS 1. Roentgenography :

AP and lateral x-rays of the lumbosacral spine are taken. They help to rule out bony pathology and also help to reveal disc degeneration by the loss of disc height in lateral view. Anterior disc space narrows in the early stages followed by total narrowing of disc height. Osteophytes begin to appear and facet joint degeneration begins to appear as the disease progresses.⁴⁸

2. Myelography:

This is considered the gold standard investigation in which about 3-5 ml of omnipaque is injected into the subarachnoid space and the patient is taken x rays on a tilting table. Obliteration of the arachnoid spaces below the nerve roots is of diagnostic value.

The typical myelographic appearances of disc lesions are

A. Lateral indentation and deformation by disc protrusion posterolaterally

B. Hourglass deformity due to central bulge C. Root-pouch filling defects

D. Complete or incomplete obliteration at the level of the herniation³⁹

3. Computed tomography:

CT scan with multiplanar reformations (CT-MPR)

Modifies the standard axial ct imaging of the spine into a more useful imaging study. Reformatted ct scan provides enlarged axial and sagittal views which can be even enhanced by contrast meyelography A three dimensional view of the spine and its surrounding structures can be obtained. The lumbar disc herniation is seen as focal, asymmetric and dorsolateral in location and is seen to lie opposing the nerve root traversing that disc causing demonstrable nerve root compression or displacement of the nerve root and foraminal encroachment by disc can be seen.

The major limitation is that it cannot differentiate scar from reherniation and poor soft tissue diferentiation between annulus and nucleus pulposus. The final limitation is because we cannot differentiate contained and non contained discs.⁴⁸

4) MRI scan:

In 1977, MRI was first developed in a Nottingham laboratory that uses the technique of interaction between an atom and the external electromagnetc field that is oscillating. T1 weighted images give a good imaging of the cord and nerve roots while T2 images provide myelogram like imaging to differentiate between disc annulosus and pulposus. Gadolinium labeled diethylene triamine pentaacetate (GD-DTPA) provides better contrast imaging.

All the stges of disc herniation can be perfectly imaged with MRI-contained and

1

Other diagnostic tests:

All associated diseases can be ruled out using these tests.

1) electromyography – to rule out peripheral neuropathy.

2) somatosensory evoked potentials (SSEP) – to identify the level of root involvement.

3) positron emission tomography (pet).

4) injection studies - a) differential spinal

b) root infiltration or block

c) discography.¹

.

TREATMENT

Management is focussed towards removing the compression on the nerve root by various modalities. The protruded disc lesion gets eaten by macrophages, granulocytes and lymphocytes and scarring heals the annulus fibrosus tear. These are classified broadly as non operative and operative.

Conservative treatment in the form of rest, medications and physiotherapy, epidural steroid infiltrations are the non-operative treatment available.

Operative techniques in current use are chemonucleolysis, standard laminectomy, discectomy, microscopic discectomy, spinal fusion and total disc replacement.

I) Conservative treatment:

A variety of conservative nonoperative treatment options are available ranging from simple bed rest to expensive traction kits. The treatment in the acute stage is strict bed rest with non weight bearing, pain killers, muscle relaxants and physiotherapy.

a) Bed rest :

3 weeks of bed rest is usually sufficient. Strengthening exercises are advised only when the patient gets pain relief and is devoid of muscle spasm.

Several studies have found that laying on the side with hip and knees flexed with a pillow between the legs or on the semi fowlers positon takes off almost all the pressure from the nerve roots but use of pelvic traction and skin traction is still in debate.

Though bike and car driving is discouraged, after pain relief patients are motivated to undergo abdomen and spine strengthening exercises and walk within the comfort of patient limits.

b) Drug therapy :

NSAIDs, sleeping pills and muscle relaxants are given as supplements along with bed rest and physiotherapy.³⁹

c) Physiotherapy :

Proper sitting posture, lifting and lying positions are advised to the patient either in the form of individual exercises or group instructions. This type of education constitutes “back school” exercises to educate the patient regarding proper posture and body biomechanics. All the muscle groups need to be focussed rather than focussing on single muscle groups. Short wave diathermy, TENS and IFT are the most used methods.

- TRANSCUTANEOUS ELECTRICAL NERVE STIMULATION (TENS) gives good response in many patients acting by the principle of gate control theory of pain blocking the afferent large nerve fibres which are inhibited by application of pulsed rectangular wave current through surface electrodes.

- SHORT WAVE DIATHERMY are high frequency currents in the range of 27.12 Mhz that produces deep pain and increases local blood flow thus washing away all the painful metabolites.

- Interferential Therapy produces low frequency alternating selectively at any tissue depth. These interferential currents cause inhibition of sympathetic system and cause vasodilation washing away local metabolites. It also reduces pain based on gate theory of Melzack and Wall.

- Skin traction with bed rest and back.

- Braces or corsets are also advised as supportive measures. Ultrasonic massage and short wave diathermy are also used in pain relief.¹

d) Epidural steroids :

Reduction of the inflammation around the nerve root is achieved by injection of long acting steroid with an anaesthetic in the epidural space surrounding the nerve roots. Pain relief upto three weeks have been reported with 70% satisfactory results. However transient motor weakness and spinal headaches can occur as complications. ¹

II) Surgical Management

Several surgical techniques are used when the conservative management fails.

1) Chemonucleolysis

2) Standard laminectomy and fenestration discectomy 3) Microscope assisted lumbar discectomy

4) Percutaneous discectomy 5) Discectomy and spinal fusion 6) Total disc replacement

1) Chemonucleolysis:

Lyman smith in 1963 first described enzymatic dissolution of disc using chymopapain. Due to the hazards of it, its use was restricted.⁷

Surgical treatment Indications:

1) Absolute indication is cauda equina syndrome with bladder involvement, saddle anaesthesia.

2) Progressing neurological impairment.

3) Failed conservative management after 6 weeks.

4) Severe and recurring sciatica pain.

Surgical options available are – 1) The posterior approach :-

• standard laminectromy and discectomy

• fenestration operation – limited laminotomy

• microsurgical laminotomy with disc fragment excision 2) Anterior approach with or without interbody fusion.

3) Percutaneous approach – suction, laser or arthroscopic discectomy.

General principles:

Anaesthesia used is general anaesthesia with patient in kneeling position or prone with bolsters under the chest and anterior superior iliac spine allowing the abdomen to hang free and reduces epidural venous dilatation and intraoperative bleeding.

Neural structures should be carefully protected. Bipolar cautery is used to control epidural bleed. Sponging and cottonoid patties should extend to the outside. Pre marked pituitary rongeurs should be used to prevent trauma to abdominal structures and aorta. Post operative epidural fibrosis is best prevented by the use of autologous fat chunk. The surgical outcomes depend mainly on the patient selection. Microscopes and magnifying glasses can be used to give a better view of the surgical field.³⁹

Long term studies comparing surgical and conservative management of patients have found no significant differences in the long term

Complications:

The complications associated with standard laminectomy and discectomy are –

1) Infection

A) Superficial wound infection

B) Deep – disc space infection - discitis 2) Thromboplebitis / deep vein thrombosis 3) Pulmonary embolism

4) Dural tears – leading to pseudomeningocoele, CSF leak, and meningitis. Dural tears are best repaired with 6.0 or 7.0 material using a simple or running locking stitch. Fascial graft may be sutured to the dura in cases of large tears of dura. Muscles and facsia are

closed with non absorbable sutures in two layers, Patient is advised bed rest in supine position for the next 4 to 7 days following surgery.

5) Postoperative cauda-equina lesions

6) Neurological damage or nerve-root injury 7) Urinary infections and urinary retentions 8) CSF fistula

9) Pyogenic spondylitis

10) Lacerations of abdominal vessels 11) Injury to abdominal viscera 12) Paralytic ileus.

MATERIALS AND METHODS

Cases satisfying the inclusion and exclusion criteria in our hospital were included in our study.

Inclusion criteria:

A. Age 18-70 years.

B. Both sexes.

C. Failure to respond to non-operative treatment.

D. Presence of positive root tension signs with or without neurological deficits.

E. MRI scan- showing disc prolapse with correlating to the dermatomal and neurological lesion.

Exclusion criteria:

1) More than two level of involvement (in which other procedure like fusion was needed).

2) Failed back syndrome (in which fusion warned).

3) Less than 18 years of age.

4) Associated spinal canal stenosis.

5) Patient with other spinal problems like:

- Spondylolysis.

- Spondylolisthesis.

- Scoliosis.

- Infective arthritis.

6) History of previous low back operation.

7) Inability to undergo full sequenced lumbar imaging.

8) Magnetic resonance imaging.

9) Disc prolapse coexisting with spinal malignancies.

10) Spinal infections.

All patients were examined and a thorough clinical examination was made and findings recorded. Plain x rays with anteroposterior and lateral views of lumbar spine including flexion and extension views were taken to rule out any spondylolisthesis and other fractures and also to diagnose level of lesion by disc space reduction. Preoperative and postoperative JOAS was made and results compared.

CONVENTIONAL OPEN FENESTRATION AND DISCECTOMY Surgery was done for all patients in the prone position. The level of disc of prolapse was marked intraoperatively. Follow up was done at one month, 3 months and 6 months following surgery. The Japanese Orthopaedic Association low backache score was used pre and postoperatively to assess the outcome.

• Excellent - 90 to 100 % improvement

• Good - 75 to 90% improvement

• Fair - 50 to 74% improvement

• Poor - Below 49% improvement

All the postoperative pain, neurological improvement and day to day activities were all recorded and evaluated.

OPERATIVE PROCEDURE

Standard open fenestration and discectomy:

Preoperative preparations:

1) Patient was kept nil per oral from the night before surgery 2) Spine prepared by soap and water and entire back prepared 3) Preoperative antibiotics were administered

Anesthesia:

General anesthesia was given.

Position of the patient:

Knee-chest position with the abdomen hanging to prevent bleeding from epidural veins.

Approach:

Back is painted and drapped and infiltration done by lignocaine, sodium bicarbonate and adrenaline mixture. A mid-line vertical incision of 5-8 centimetres is made over the spinous process after marking under image intensifier. Incision is deepened and the lumbodorsal fascia is incised and the supraspinous ligament is split over the involved disc space. Strip the paraspinal muscles from the spines and laminae of the vertebrae on either side by the technique of subperiosteal dissection and self retaining retractors are applied.

Using a kerrison rongeur, the laminae are carefully nibbled and the ligamentum flavum is scribed. Now the cord is exposed and the dura is retracted using a cord retractor and the nerve root is visualised. The nerve root is retracted along its shoulder medially.

Using a root retractor to expose the underlying disc. The disc may be seen as a bulge in the posterior longitudinal ligament or as an extrusion.

Cottonoid sponges are used to arrest the bleed from epidural veins. The disc fragments are removed using a pituitary forceps until the bulge has been decompressed. Suction and cottonoid patties are used to control bleeding.

Wound is closed in layers and sterile dressing is applied.

A )MAR IMA

C) FEN CO

RKING LE AGE INTE

NESTRAT ORD VISU

EVEL UND ENSIFIER

TION WIT ALISATIO

E) DISC F DER R

TH ON

CECTOM FOR B

B) SK

D)

MY SPECIM BIOPSY

KIN INCIS DISSECT

) DISCEC

MEN

SION AND TION

CTOMY D

INSTRRUMENTTS USED IIN THE PRROCEDUURE

POST-OPERATIVE REGIMEN

o Neurological function is regularly examined after surgery o Turning in bed is allowed

o Intravenous antibiotics are given for three days and adequate analgesia is given

o Sitting and walking are allowed with lumbosacral orthosis

o After back pain subsides in the initial post operative days, isotonic exercises are begun

o Dressing is changed on the second post op day and alternate day till no soakage occurs

o The sutures are removed on 12^th post-operative day

o Sitting and walking are eventually increased every week till 6 weeks.

o Lifting, bending and stooping are prohibited for 3 months and during the second post op month, backschool training is strictly enforced o Patients with intense jobs are advised change of job

Multiple factors decide the outcome lumbar disc surgery. Meaning that patient selection is the key to success. Also lumbar spine surgery without lifestyle modifications and physiotherapy has always resulted in poor results.

Only when the correlation between the clinical presentation and radiological studies are similar, results of lumbar disc surgery are excellent.

MICRO LUMBAR DISC EXCISION :

Microscopic removal of disc material by performing a laminotomy has enabled performance of discectomy as outpatient procedure, better lighting, magnified view and much smaller exposure are its advantages. ⁴⁷

PERCUTANEOUS DISCECTOMY:

Endoscopic techniques have come a long way to perform these procedures. This allows for minimal hospital stay and earlier return to activity. ⁴⁷

DISCECTOMY AND INTERBODY FUSION:

Patients who underwent discectomy at a single level subsequently developed low backache in the coming years due to motion segment degeneration in the adjacent levels. Hence instability and poor outcomes result.

To avoid this discectomy followed by interbody fusion is performed and this has resulted in decreased degenerative changes in the adjacent motion segments, anterior lumbar interbody fusion techniques, postero lateral interbody fusion techniques, posterior interbody fusion techniques, and combined anterior and posterior fusion are many of the techniques done.⁴⁷

There are a variety of stabilization alternatives - interbody devices, pedicle screw fixation, cages. Solid arthrodesis is the goal of these fusion techniques. However studies also suggest accelerated degeneration with lumbar arthrodesis with these fusion procedures.

TOTAL DISC REPLACEMENT:

With isolated disc prolapsed and the involved disc level having a normal facet joint, total disc replacement through anterior approach can be performed and this is gaining interest in the last 5 years as the motion segment of spine is preserved. However long term studies are not available and knowledge of revision studies are still an area of research.⁴⁷

RESULTS AND ANALYSIS

This study consists of 30 patients with lumbar disc prolapse treated by fenestration discectomy during the period of 2017-2019 at our institute. The age of the patients was in the range of 20 to 70 years with a mean age of 42.9 years.

AGE DISTRIBUTION Table 1

Age in years No. Of cases Percentage

20-30 5 16.66 30-40 11 36.66 40-50 6 20 50-60 5 16.66

>60 3 10 total 30 100

20-30 31-40 41-50 51-60 >60

age 5 11 6 5 3

Percentage 16.66 36.66 20 16.66 10

0 5 10 15 20 25 30 35 40

AGE DISTRIBUTION

F

FEMA 40%

SEX MALE FEMALE

TOTAL

ALE

%

SE

T

SEX

X DISTRI Table TOTAL C

18 12 30

X DISTRI

IBUTION e 2

ASES

BUTION

N

PERC

MALE 60%

N

CENTAGE 60

40 100

E

OCCUPATION Table 3

OCCUPATION CASES PERCENTAGE

UNSKILLED LABOUR 17 56.6%

HOUSE WIFE 7 23.3%

TECHIE 2 6.66%

AGRICULTURIST 1 3.33%

BUTCHER 1 3.33%

BUSSINESSMAN 1 3.33%

STUDENT 1 3.33%

TOTAL CASES 30 100%

0 5 10 15 20 25 30 35

UNSKILLED LABOUR HOUSE WIFE TECHIE AGRICULTURIST BUTCHER BUSSINESSMAN STUDENT TOTAL CASES

UNSKILLE D LABOUR

HOUSE

WIFE TECHIE AGRICUL

TURIST BUTCHERBUSSINES

SMAN STUDENT TOTAL CASES PERCENTAGE 56.60% 23.30% 6.66% 3.33% 3.33% 3.33% 3.33% 100%

CASES 17 7 2 1 1 1 1 30

OCCUPATION

The occupation of the patients were studied and unskilled labour were found to amount to the majority of our study with history of weight lifting and long day standing followed by house wifes who revealed history of sternous household activity with activities involving long duration forward bending.

Technical professionals and farmers were also part of the study. Average duration of symptoms was 12.2 months in the range of 3 to 30 months. All patients had radicular pain and low back ache which were the main presenting complaint with nerve tension signs. Ten patients had motor deficit and 19 patients had parasthesia and sensory deficit. Bladder and bowel sensation were intact in all the patients involved in the study.

SYMPTOMS AND SIGNS TABLE 4

SYMPTOMS AND SIGNS CASES PERCENTAGE

RADICULAR PAIN 30 100%

NERVE TENSION SIGNS 30 100%

MOTOR DEFICIT 10 33.3%

SENSORY DEFICIT 19 63.3%

BLADDER/BOWEL INVOLVEMENT

NIL NIL

RADICULAR PAIN

NERVE TENSION

SIGNS

MOTOR DEFICIT

SENSORY DEFICIT

BLADDER/B OWEL INVOLVEME

NT

SYMPTOMS AND SIGNS 30 30 10 19 0

PERCENTAGE 100% 100% 33.30% 63.30% 0

0 5 10 15 20 25 30 35