THORACIC DISC DISEASEm. dehnokhalaji

THORACIC DISC DISEASE the least common location for disc pathology. Symptomatic thoracic disc herniations remain rare, with

an estimated incidence of one in 1 million individuals per year.

They represent 0.25% to 0.75% of the total incidence of symptomatic disc herniations.

The most common age at onset is between the fourth and sixth decades.

the incidence of asymptomatic disc herniations is high 37%

SIGNS AND SYMPTOMS The natural history of symptomatic thoracic disc

disease is similar to that in other areas, in that symptoms and function typically improve with conservative treatment and time.

The differential diagnosis nonspinal causes the cardiopulmonary, gastrointestinal,

and musculoskeletal systems. Spinal causes infectious, neoplastic, degenerative, and

metabolic problems within the spinal column and the spinal cord.

SIGNS AND SYMPTOMSTwo general patient populations

1. The smaller group of patients is younger and has a relatively short history of symptoms, often with a history of trauma. Typically, an acute soft disc herniation with either acute spinal cord compression or radiculopathy is present. Outcome generally is favorable with operative or nonoperative treatment.

2. The larger group of patients has a longer history, often >6 to 12 months of symptoms, which result from chronic spinal cord or root compression. Disc degeneration, often with calcification of the disc, is the underlying process.

SIGNS AND SYMPTOMS Pain the most common presenting Two patterns : axial, and bandlike radicular pain along the

course of the intercostal nerve. The T10 dermatomal level is the most commonly reported

distribution, regardless of the level of involvement. This is a band extending around the lower lateral thorax and

caudad to the level of the umbilicus. This radicular pattern is more common with upper thoracic

and lateral disc herniations. Associated sensory changes of paresthesias and

dysesthesia in a dermatomal distribution also occur .

SIGNS AND SYMPTOMS High thoracic discs (T2 to T5) can manifest similarly to cervical

disc disease with upper arm pain, paresthesias, radiculopathy, and Horner syndrome.

Myelopathy also may occur. Complaints of weakness, which may be generalized by the patient, typically involving both lower extremities occur in the form of mild paraparesis.

Sustained clonus, a positive Babinski sign, and wide based and spastic gait all are signs of myelopathy.

Bowel and bladder dysfunction occur in only 15% to 20% of these patients.

Abdominal reflexes, cremasteric reflex, dermatomal sensory evaluation, rectus abdominis contraction symmetry, lower extremity reflexes and strength and sensory examinations, and determination of long tract findings all are important.

TREATMENT RESULTS nonoperative treatment usually is effective.

short term rest, pain relief, antiinflammatory agents, and progressive directed activity restoration

should be continued at least 6 to 12 weeks if feasible. Surgery indications:

If neurological deficits progress manifest as myelopathy, if pain remains at an intolerable level

OPERATIVE TREATMENT Simple laminectomy has no role in the treatment of thoracic

disc herniations. Posterior approaches, including costotransversectomy,

transpedicular approach, transfacet pedicle sparing, transdural, and lateral extracavitary approach, all have been used successfully.

Most more recent studies suggest that lateral rachiotomy (modified costotransversectomy) or an anterior transthoracic approach for discectomy produces considerably better results with no evidence of worsening after the procedure.

Anterior approaches via thoracotomy, a transsternal approach, retropleural approach, or VATS also have been used successfully.

THORACIC DISCECTOMYANTERIOR APPROACH

Case presentation Female 21 y/o Back pain from 1.5 years ago Exacerbated after child delivery (9m ago) Pain radiated to right leg from 7m ago

P/E ↓L3 , L4 force right clonus ↓ achilles DTR QC DTR normal Babinski sign normal Intermittent Bladder dysfunction Sensory normal

headfoot

Ant.

lateral decubitus position. A leftsided anterior approach usually is preferredskin incision along the line of the rib that corresponds to the second thoracic vertebra above the involved intervertebral disc except for approaches to the upper five thoracic segments, where the approach is through the third rib.

Post.

10th rib

headfoot

Ant.

headfoot

Ant.

diaphragm

headfoot

Ant.

The segmental vessels

The parietal pleura

T12-L1 disc

T12-L1 disc

ALL L1 T12

T12-L1 discALL

L1 T12

T12-L1 discALL

L1 T12

POSTOPERATIVE CARE Postoperative care is the same as for a thoracotomy. The patient is allowed to walk after the chest tubes are removed. Extension in any position is prohibited.

A brace or body cast that limits extension should be used if the stability of the graft is questionable.

The graft usually is stable without support if only one disc space is removed.

Postoperative care is the same as for anterior corpectomy and fusion if more than one disc level is removed.

If no fusion is done, the patient is mobilized as pain permits without a brace.