2. • Review article.
• Study conducted at Department of Orthopaedic
surgery, Seoul Sacred Heart General Hospital,
Seoul, Korea.
• Published online in September 2013, Asian Spine
Journal
• Cite: Asian Spine J 2014;8(1):89-96.
• Citation count: 14
3. • Ligamentum Flavum(LF) connects adjoining
two laminae at the posterior side of dura
mater, separated at midline
• Divided into capsular & inter-laminar part.
• Incidence upto 20% in >65 years old
Japanese elderly population but can be
seen in other countries as well.
• Extends from C2 to sacral vertebra
• Attaches to anterior lamina of superior
vertebra to superior lamina of inferior
vertebra
Netter’s concise orthopaedic anatomy, 2nd edition, Frank Netter et al.
5. - Dorsal myelopathy : OPLL>OLF>HNP
- Site: Lower thoracic>high thoracic> mid thoracic
- MC site: T10 and T11.
- Begins at capsular—>interlaminar & posterior—>dural.
6. Clinical Features
• Often missed & delayed
• Local pain & features of myelopathy are
sine qua non.
• Posterior cord syndrome—>spastic
paraparesis—>loss of sensation.
• Loss of functional gait is MC manifestation.
• Atypical presentation - when myelopathy
develops acutely as in acute compression
frx
• Important to perform whole Spine MRI to
rule out double crush syndrome.
8. Treatment
• Sequence of decompression- IAP & Inferior lamina excised—> ossified ligament
separated from dura mater—> OLF & SAP are ground into paper-thin plate—>
excision.
• If there is dural ossification, floating laminectomy is used.
• Floating method is insufficient if dural ossification extends upto foramen.
• Epidural plexus & dural pulsation can atrophy the dural ossification mass, thus
obviating any need for decompression at foramen.
9. • In summary, when OLF is lateral, extended or
enlarged at a single intervertebral level,
fenestration ( laminotomy ) is the choice.
• French-door laminectomy is indicated in multilevel
cases.
• For fused or tuberous type, en-bloc laminectomy is
indicated.
• If complicated by ossification of dura mater the
removal of ossified mass and surrounding dura
mater is performed, leaving arachnoid intact.
Ossification of posterior longitudinal ligament, 2nd edition, K. Yonenobu et al.
10. • Dural ossification is present in
11-40% of cases.
• Comma sign - ossified mass
which encompass >2/3rd dura
mater
• Tram track sign - low-signal
line between parallel bone
plates which looks like rail
road.
11. • Decompression is followed by
fusion to obviate the continuous
tensile force which may prevent
local recurrence & development
of kyphosis.
• Improvement after
decompression maybe upto 50%
though not complete.
• The most important factor in most
studies is severity of pre-operative
symptoms & time interval before
surgery.
12. • OLF causes slow progressive myelopathy seen more in East Asians.
• As cord is compressed first, posterior cord syndrome develops first followed
by spastic paresis followed by gait imbalance.
• Prompt surgical decompression is necessary when myelopathy symptoms
develop.
• The more severe the pre-operative symptoms are and the longer the
decompression surgery is delayed, the poorer the surgical outcome.
• An acute severe myelopathy can develop after a minor trauma to a pre-
existing OLF, in which case the prognosis is not so favourable.
In conclusion...
13. Mr. X 57/M
• Post-tubercular discittis D12, treated with
reconstruction & fusion D10-L2 in 2017.
• Completed one year of AKT
• Developed difficulty in gait, weakness of
lower limbs, walking with assistance,
presented in Feb 2019, finally
deteriorating to Grade V Nurick’s.
• Bowel & bladder not involved.
14.
15. • Implants removed at lower level.
• Wide laminectomy with decompression
done from D6-9 done.
• Intra-op dural ossification was seen -
floating procedure done.
• Post-operative patient is recovering,
uneventful.
16. Outcomes
• It is evaluated by modified version
of mJOA.
• It includes motor function of lower
limb, with sensory function of lower
limb & trunk, sphincter dysfunction.
• Total score is 11.
• Recovery rate (%) is calculated as:
(Postoperative JOA-Preoperative JOA)/
(11-preoperative JOA score) x 100.
Ossification of posterior longitudinal ligament, 2nd edition, K. Yonenobu et al.
