Free Fragments in Lumbar
Choithram Hospital & Research Centre
Indore, MP, India
• A piece of Nucleolus pulposus with
Annulus Fribrosus & fragments of
cartilagenous end-plate, lying loose in
the spinal canal.
• It may migrate up or down a level or
two, may migrate posterior to dura or
perforate dura. Incidence - 9 to 15.5%
Presence of free fragments of extruded disc material is usually considered as a severe form of PID and it is considered as
a strong indication for surgery. How ever when patient is not willing for surgery, a phobia is created into the mind of the
patient regarding possible paraplagia (cuada-equina syndrome).
Types of Disk Disease
Disk Bulge Disk Herniation
General term used to
Disk bulges into anterior describe different degrees
epidural space without any of 'eccentric out-pouching'
area of focal-ness or out- of IV disk.
Protrusion Extrusion Sequestration
herniation or sub- herniation, or
ligamentous trans- free
There is quite confusing terminology used in the description of prolapse IVD. An attempt was by providing an MRI
classification of degree of protrusion. Basically In this classification, two terminologies are most frequently used. These
are “A contained disc”, or a non-contained disc. All contained disc varies from a simple disc dehydration - annular bulge –
varying degree of prolapses. While all non-contained disc extrusion are for all practical purposes – free fragments.
Free Fragments Free Fragments
A free fragment can be migrate to any of the places as shown in the slide.
Any portion of the extruded disc if seen against the posterior part of vertebral body, it should be considered as a free
Literature – Free Fragment
• Incidence - 9 to 15.5%
• Composition – N.P. / A.F. + fragments of end plate
• Lateral migration – cranial & caudal
• Posterior migration – cauda equina – mimic tumour
• Intra dural more than 60 cases reported-world
• Roof disc : central disc extrusion : contained by
There are three special situations.
One : migration intra-dural. This is always associated with cauda-equina syndrome. Only 60 cases have been reported in
the world literature.
Second: Migration posterior to the dural sac. It cannot be diagnosed even on MRI and usually it gives a picture of Spinal
A third situation is also commonly seen – Roof disc. It is central extrusion but still contained by the posterior longitudinal
ligament. Here symptoms are different and there may not be much root pain but with profound neurological deficit.
• Since it is impossible to predict on MRI, that a
migrated fragment have some continuity with the
parent disc or not - it should be considered as
• There is a real possibility of migration of the
fragment and increase in the neuro-deficit.
• It is immaterial where the migration is.
• Migration may progress in the initial phase of
extrusion, it may migrate one or two level – up or
Composition of extruded material
• Nucleolus pulposus
• Annulus fibrosus
• Fragments of Cartilage end plate.
• The disc formation takes place before the
immune system develops in the embryonic
• The proteins in the nucleosus pulposus
are foreign to immune system in adults.
• The free fragment is treated as foreign
protein and a reactive granuloma forms,
which absorbs the free fragment.
Inui, Yoshihiro et al in Spine. 29(21):2365-2369, November 1, 2004.
Fas-Ligand Expression on Nucleus Pulposus Begins in Developing Embryo. Expressed there views as - The present results demonstrated that Fas ligand expression is not detected in
the notochord, but at the time of intervertebral disc formation, Fas ligand expression develops in the nucleus pulposus. These results indicate that the immune privilege of the
intervertebral disc may begin in the very early stages of disc formation. Moreover, Fas ligand may play an important role in the formation of the intervertebral disc.
There are three proposed hypothesis for absorption. The first proposed hypothesis is the retraction back into the intervertebral space. If there is bulging or herniation into the annulus
fibrosis, this situation can be encountered theoretically. Second hypothesis is based on the concept of dehydration ( shrinkage with the loss of the water content of the herniated disc
material), slowly The recent studies asserted that the spontaneous regression, to be a result of enzymatic degradation and phagocytosis against the extruded disc tissue in the
epidural space with inflammatory reaction and neovacularization . There are some pathological and experimental studies supporting this situation. There is also possibility that all 3 of
these mechanisms take part in the spontaneous regression and disappearing of the disc material altogether. In journal of Neurological Sciences Volume 23, Number 4, Page(s) 339-
343, 2006, Mehmet ŞENOĞLU, Kasım Zafer YÜKSEL, and Mürvet YÜKSEL reported two cases of spontaneous absorption.
Absorption- composition & time
• Nucleolus Puplposus: absorb by formation
of granulation tissue possibly as an auto-
immune reaction. 3 months
• The Annulus Fibrosus: absorb by
granulation tissue by vascular invasion.
1 – 2 years
• The Hyline cartilage of end-plate:
resistant to absorb
Radicular pain from the compressed nerve root is due to sensitization of the nerve root as a result of inflammation induced by antigen – antibody reaction. This is the reason for a quick
response to cortisone therapy in acute prolapse. This is the reason why fragments mainly composed of nucleolus pulposus get absorbed early. The annulus is absorbed by
granulation formation. Lumbar Disk Herniation:Correlation of Histologic Findings with Marrow Signal Intensity Changes in Vertebral Gebhard Schmid, MD. Endplates at
MR Imaging- Gebhard Schmid et al published in “Radiology Vol 231 No.2 - Findings in the current study show that avulsion-type disk herniation with hyaline cartilage material
occurs frequently (in nearly 50% of patients). The amount of cartilage may be as much as 50% of the extruded material, and bone fragments were observed in five patients. Our results
confirm that there is cartilaginous material in a high proportion of extruded disk herniations. The amount of cartilage in the herniation material is usually less than 10%, but it can be as
much as 50%. The association of the amount of cartilaginous material with endplate abnormalities supports the theory that avulsion of the vertebral endplate is one source of disk
herniation. The good correlation of marrow signal intensity changes in the middle third of the endplate with cartilaginous material in the disk herniation further supports the
histopathologic findings by Tanaka et al (22) that most avulsions occur in the inner or transitional zone of the annulus end plate interface. Spine 1997; 22:1429–1434.
Carreon LY, Ito T, Yamada M, Uchiyama S, Takahashi HE. Neovascularization induced by annulus and its inhibition by cartilage endplate: its role in disc absorption.
• The amount of hyaline cartilage, should be
predictable on the basis of imaging data.
• Vertebral endplate marrow signal intensity
changes are associated with ﬁssures in
the vertebral end-plate.
• Signal intensity changes may be regarded
as osteo-cartilaginous fracture signs
similar to other skeletal manifestations.
MRI – showing End-plate lesion,
Indicating a portion of end-plate
avulsion in the extruded disc &
Will take long time to absorbed or
reduction in size.
Early surgery may be
Published in Radiology Vol 231 No.2 358, May 2004 Schmid et al.
A 35 male, had acute disc
extrusion at L4-L5 rt.
With free fragment in the canal
A follow up MRI after 2months
Showing End-Plate edema L5.
A 35 male with acute backache sciatica had mild EHL weakness ( Stable, monoradiculopathy rt L5).
The initial MRI and a follow-up MRI showing persistence of End-plate edema. This is indicating that
Absorption of the disc fragment will take long time. A surgery can be advised at this stage. Due to
Stable neurology and minimal pain, patient refused surgery. There is perceptible reduction in size.
Fate of Free Fragment –Complete absorption
• Sei A, Nakamura T et al 1994
• Coevoet V et al t.d. 1997
• Westmark RM et al c.d. 1997
• Miller S et al 1998
• Singh P, Singh AP. 1998
• Morandi X et al 1999
• Kobayashi N et al c.d. 2003
More than 55% of absorption is clinically significant
Follow up MRI – every 3 months for one year
Spontaneous changes on MRI &
- 42 cases treated conservatively.
Takada & Takahashi
• MRI changes Cases Excellent Good Poor
Disappearance 08 06 02 00
More 50% 29 11 18 00
No reduction 05 00 01 04
50% involution in 3 – 6 months
J.of Orthopaedic Surgery 2001, 9(1): 1–7
• Number of cases 80
• M/F same
• Age 20 – 70
• Duration of symptoms 01 – 90
• No deficit 06
• Mono-radiculopathy 59
• Poly-radiculopathy 13
• Delayed Cauda-equina 02
• Stable neurological deficit & Presented
late > than one week.
• Bearable radicular pain with negative root
stretching test (SLRT).
• No bladder or bowel dysfunction.
• Patient not willing for surgery but gave
consent for surgery as & when needed.
Kept under strict watchful supervision.
The clinical picture and MRI findings frightens both, the surgeon and the patient. Almost all patients seen by were as third
or forth consultation. Patient too much afraid of surgery and has already delayed the surgery by cross consultations. It
became very easy for me to treat these patients using their own psyche. Specially patients with no more radicular pain
and with stable neurological deficit, or deficit confined to single root.
R.K.- Absorption one month
• A 25 M
• Acute agonizing pain 5 days duration
• Spinal flexion 50%, EHL lt weak gr3
• No bladder – bowel dysfunction.
• Pain minimal
• MRI extruded disc at L5-S1 left
• Repeat MRI after one month – extruded
fragment (N.P.)absorbed completely.
R.K. was very young and about to get married. He had no radicular pain after the initial attack and a fired L5 root.
He insisted on having a repeat MRI with in one month and the nucleolus part of the disc was already absorbed by this
N.K.- Complete absorption one year
• H/o backache sciatica 2005 – MRI
degenerated discs at L4-L5, L5-S1.
• Extruded disc in 2006 – with no
• Tx – conservatively with complete
absorption of free fragment.
She is very interesting case. She had acute backache in 2005. The MRI at that time showed dehydration and bulge at L4-
L5, and L5-S1. she was treated as acute lumbago. She had frank extrusion at L5-S1 in 2006. If proper back care advice
was given her, she might have been saved from extrusion. She had past experience of conservative treatment, she
refused for surgery this time. I was 7th surgeon for consultation. However she had total absorption of the disc material in a
Case history – U.S.
• 45 M,
• Acute backache sciatica 15 days duration
• Attended clinic as OPD patient.
• L5 – S1 Rt. with loose fragment over L5 body
• Measuring 2.4cm x 1.5cm
• Full flexion spine and negative SLRT
• Mild gr.4 weakness in EHL and Hypoasthesia in
• Tx conservatively
Yet another case where familial tendency of disc disease came my knowledge. His elder brother was operated for disc at
L4 – L5, His younger brother had cervical C5-C6 disc treated conservatively. His elder brother’s son have contained disc
He had complete extrusion of L5-S1- migrated against the body of L5. Complete absorption took one year.
Reduction in size
• More than 50% reduction in size on follow-
up MRI is clinically significant.
• Bigger the size, better the chances of
reduction and better clinical outcome.
Eiichi Takada and Masaya Takahashi - E Takada et al. Journal of Orthopaedic Surgery Vol. 9 No. 1, June 2001 Natural
history of lumbar disc hernia with radicular leg pain.
Case report Mrs. W.
Before & after 6 months
fragment extruded beween S1 root & card - conservative
Before & after 6 months
> 50% reduction in size
Patient when reported late
• It is usually for a second opinion.
– For persisting pain
– No improvement in neurological deficit.
– It is stable neurology.
– May be a case for surgical intervention.
– Some times Epidural steroids works.
In my opinion probably this is the precise indication for epidural steroids.
These are late presentations, with stable neurology but persistent radicular pain.
A weekly epidual Methyl Prednisolone 80mg and maximum three injections.
Prolonged use of steroids delays the absorption has been reported in literature.
Backache sciatica Lt 3 months
Had localised pain around knee joint
Case summary – Delayed reporting
Conservative treatment failed
• Six cases
– Intractable radicular pain
– Increase in neurological deficit due to
– Increase in deficit due to central extrusion
– Poor patient compliance
– Surgery on demand
Case report – Operated for severe unbearable
pain after 3 weeks of adequate treatment
Fragment had transfixed S1 root - Surgery
It was a axillary type of extrusion where the S1 root got trapped between pedicle of S1 on one side and extruded fragment
on other. She was in severe agony and was relieved by the surgery.
Central “Roof Disc extrusion”
Operated for developing bladder
A central “roof” type extrusion needs very close observation when treated conservatively. Neurological deterioration can
occur without increase in the radicular pain. They should be operated at the earliest sign of unstable or increasing
Migration two level down Rupture of Dura –
deteriorated on conservative treatment-
Operated fragments removed transdurally
Patient was diagnosed as a case of acute PID and accordingly advised rest as there was no neurological deficit.
However patient continued his routine work in spite of increasing pain and returned back in 3 days with bladder
dysfunction. MRI at this stage showing migration two level down. He was operated by laminectomy and disc fragment
Migration of fragment after one
• Mr. M.L. 65 M.
• Pain in the gluteal region with stiff back
• No neurological deficit with – Ve SLRT.
• MRI – free fragment in the sacral canal.
• Recurrence after 1 year. Some parasthesia in
gluteal region, bladder bowel dysfunction some
• Repeat MRI – fragment size same – mild
• Tx – conservatively, asymptomatic
Probably he is one of those case where cartilagenous element is more than nucleolus pulposus and annulus fibrosus. It
has been reported that cartilage end plate contribution is more in elderly patients with disc extrusion.
Fragment did not absorb even after
one year, migrated minimally down
• All Tx conservative initially
• Strict Bed Rest in position of comfort
• No pelvic / limb traction
• Sitting strictly prohibited
• Supportive drugs Tx – steroids sos.
• Frequent neurological examination
• Bed rest cont… till SLRT become -ve
Management - Protocol
• Gradual Mobilization in the house
• Exercises programme
– Straight leg raising
– Knee bending to chest
– Forward bending in sitting postion
– Forward bending in standing
– Back care ( jerk, weight lifting, bending,
sitting at work etc.
Strict instructions regarding reporting of
All exercises are prescribed as per the tolerance of the patient.
• At 3 months
• At 6 months
• At 12 months
• Fragment mainly consist of NP will
absorbed in 3 months
• Fragment mainly consisting of NP+AF will
take 6 months – one year
• Fragment consist of end plate cartilage
take longer time – more than 2 years.
Since it is not possible to have a strict regime for all patients because of financial constrains, follow up MRI were done as
per affordability of the patients.
• negative crossed straight-leg-raising test,
• absence of leg pain with spinal extension,
• absence of stenosis on imaging studies,
• favorable response to steroids,
• normal psychological profile,
• a motivated physically fit patient,
• more than twelve years of education,
• no Workers’ Compensation claim.
These types of patients are ideally suited for conservative management specially with monoradiculopathy of stable nature
( not progressive)
• Extruded disc – acute onset
• Fragment is free in the canal and migrate
• It is more likely to cause neurological
deficit when it get trapped at narrow parts
of spinal canal.
• It take roughly two weeks for the fragment
to get fixed by the granulation tissue.
• Traction immobilize the patient is a fixed
• Muscle spasm is basically protective and keep
the patient in a posture which protect the
compressed nerve root.
• An alteration in posture by forceful traction
increases the chances of damage to nerve root.
• Traction should be avoided for acute pain.
For acute disc prolapse – in my opinion traction is contra-indicated. It causes more harm than do any good.
There are ample literature against traction. It may be good for chronic backache. A detailed summary has been published
in JB&JS 2006 under current concepts in spine.
Sitting posture to be avoided
• Maximum pressure on the damaged disc
occur in sitting posture specially with
• It increases the chances of further
displacement or migration of the fragment.
Sitting posture increases intra-discal pressure
Relative increases and decreases in intradiscal pressure in relation to different body positions. Note that seated and
bending postures apply more pressure to the disc than do standing and recumbent positions. This explains the
exacerbation of symptoms of herniated disc when patients are in the former positions.
Photograph taken from net quoted by
Clinical Evaluation & Treatment of Herniated Lumbar Disc
Clinical Evaluation and Treatment Options for Herniated Lumbar Disc
S. CRAIG HUMPHREYS, M.D., and JASON C. ECK, M.S. , Chattanooga, Tennessee. Copy write Scott Bodell 1999.
Primary and revision lumbar discectomy
A 16-YEAR REVIEW FROM ONE CENTRE
C. V. J. Morgan-Hough et al, England
• primary protrusions are almost three times as
likely to require revision surgery as primary
extrusions or sequestrations.
• We suggest that protrusion represents the
beginning of a process of serial fragmentation of
disc material, whereas extrusion and
sequestration are an end-stage of this process
Saal JA, Saal JS, Herzog RJ: The natural history of lumbar
intervertebral disc extrusions treated non-operatively.
Spine 15: 683–686, 1990
• Patients with large compressive lesions
are also generally believed to be more
ideally suited to surgical intervention.
These same patients, however, are those
most likely to experience spontaneous
regression of their lesions and they have a
high rate of clinical improvement with
Spangfort, - 2504 operations
• 99.5% results in complete or partial pain relief in
cases of free fragments in the canal.
• 82% Incomplete herniation or extrusion of disc.
• 63%, Excision of the bulging or protruding disc.
• 38%, removal of the normal or minimally bulging
• Failure to relieve sciatica was proportional to the
degree of herniation
Spangfort, - 2504 operations
persisted back pain
• 30% persisted back pain
• The incidence of persistent back pain after
surgery was inversely proportional to the
degree of herniation.
• In patients with complete extrusions the
incidence was about 25%, but with
minimal bulges or negative explorations
the incidence rose to over 55%.
• Protrusion – degenerated disc –
decreased height – facetal joint
degeneration – ligamentum flavum
infolding – segmental canal stenosis
• Degenerative dynamic instability
• Osteoarthritis – osteophytes in an attempt
to stabilize the spine.
• Surgery only relieve leg pain temporarily.
Radiculopathy and the Herniated Lumbar Disc. Controversies
Regarding Pathophysiology and Management
J. Bone Joint Surg. Am.
John M. Rhee, Michael Schaufele and William A. Abdu, 88:2070-
This information is current as of January 21, 2007
• Both the surgeon and the patient must
realize that disc surgery is not a cure but
may provide symptomatic relief.
• It neither stops the pathological
processes that allowed the herniation to
occur nor restores the back to a normal
• Presence of Free fragment in the canal indicates auto-
decompression of the nerve roots (SLRT –ve, Pain ↓
as nerve fired/ decompressed).
• Usually stable mono-radiculopathy – recovery is
• Patients with gross / ↑ neurological deficit should be