Thoracic Spine and Biomechanics Level III

Thorax

! Vertebromanubrial

! Vertebrosternal Level III Upper ! Vertebrochondral Lenerdene Levesque BScPT, ! MClSc, FCAMPT Thoracolumbar junction

Primal pictures Rohen JW. Yokochi C Color of Anatomy 1988

Thorax - osteology Thorax - osteology

! Paired costal demi- ! Height of body is slightly facets superior and higher posteriorly than inferior (except T1, anteriorly – kyphosis T10-T12)

! Spinous processes ! Vertebral bodies decrease project posterior and in size from T1-T3 inferior to varying degrees – very irregular

Taylor

Grays Anatomy

Lenerdene Levesque BSc.P.T., MCLsc, FCAMPT Thoracic Spine Anatomy and Biomechanics Level III

Typical Thoracic Typical Thoracic Vertebra

! Vertebral bodies are ! Demifacets for the heart-shaped, of the thicker behind ! Transverse processes project posteriorly as well ! – as laterally small, circular – ! Facets for the articular narrowest at T4-T9 portion of the tubercles of the ribs

McMinn RMH. Hutchings RT. Color Atlas of Human Anatomy 1985 McMinn RMH. Hutchings RT. Color Atlas of Human Anatomy 1985

Internal structure of thoracic vertebral body: Within a thin shell of compact , vertical trabeculae predominate; these loadbearing beams are stiffened by transverse trabeculae (cross-ties) which resist buckling of the vertical trabeculae under axial load. Cervico-thoracic junction

X-ray of mid thoracic region from cadaver spine ! width of the transverse Section of thoracic vertebral body processes ! presence of the uncinate processes ! shape of the spinal canal ! orientation of the facets – coronal plane

McMinn RMH. Hutchings RT. Color Atlas of Human Anatomy 1985

Taylor

Lenerdene Levesque BSc.P.T., MCLsc, FCAMPT Thoracic Spine Anatomy and Biomechanics Level III

Thoracolumbar Junction Thorax – osteology ! Transitional vertebra - usually T11 or T12 Ribs ! Superior articular facets are orientated in the coronal plane and the inferior in the sagittal plane ! Transverse process is replaced by three tubercles ! Single complete facet on the side of the vertebral body

A Typical Thorax - osteology

! Typical Ribs (3-9) ! Head " Two articular facets on ! the head of each rib ! Tubercle " Distal to the head is the ! Shaft neck " Distal to the neck lies two tubercles for the CT and the CT

McMinn RMH. Hutchings RT. Color Atlas of Human Anatomy 1985

Lenerdene Levesque BSc.P.T., MCLsc, FCAMPT Thoracic Spine Anatomy and Biomechanics Level III

Vertebrosternal Region Vertebrosternal Region

! Ventral aspect of the transverse process contains a deep, concave facet for articulation with the rib ! Orientation of the facet - anterolateral

McMinn RMH. Hutchings RT. Color Atlas of Human Anatomy 1985 Lee, D. The Thorax An Integrated Approach 2003

Sternum STERNOCOSTAL & INTERCHONDRAL 1 Cart Jt 2 Interchondral Jt Sternocostal Jt Synovial Synovial Eight concave facets which Radiate Lig articulate with the costocartilages of ribs 3 to 6 6

7 8 9&10, Fibrous Interchondral Ligs

McMinn RMH. Hutchings RT. Color Atlas of Human Anatomy 1985 Grays Anatomy

Lenerdene Levesque BSc.P.T., MCLsc, FCAMPT Thoracic Spine Anatomy and Biomechanics Level III

Vertebrochondral Region Vertebrochondral Region

! Facet on the superior aspect of the transverse process is flat and faces anterolateral and superior

McMinn RMH. Hutchings RT. Color Atlas of Human Anatomy 1985

Lee, D. The Thorax An Integrated Approach 2003

Vertebrochondral Region Thorax-osteology

Atypical Ribs (1,2) ! 1st rib " Small , flat, and most Anteriorly, the 8th, 9th curved of all ribs " Broad th and 10 ribs articulate " Small round head with one indirectly with the single oval articular facet via a series of cartilaginous bars which ! 2nd rib blend with the 7th costal " Longer, not as flat . " Classified as atypical only because of its attachment to the manubrium

McMinn RMH. Hutchings RT. Color Atlas of Human Anatomy 1985 Rohen JW. Yokochi C Color Atlas of Anatomy 1988

Lenerdene Levesque BSc.P.T., MCLsc, FCAMPT Thoracic Spine Anatomy and Biomechanics Level III

Thorax-osteology Thorax - Arthrology

! Interbody Joint ! Atypical Ribs " Thoracic discs are thinner th " 10 rib – single costal compared to the lumbar facet to T10 " Annulus fibrosis may be th " 11/12 ribs – single thicker in this region and no " Laterally supported by the attachment anteriorly costovertebral articulation

Contrast lower cervical (L) & upper thoracic discs (R) Thoracic discs have flat end-plates with no uncus &no uncovertebral Thoracic Discs clefts

C3 T2 ! Relatively small nucleus with less capacity to swell ! Annular fibres criss-cross forming an angle of 27-30 uncus degrees to the horizontal, posterior fibres are thin and C4 T3 vertical ! May be the presence of

horizontal clefts cervical thoracic

Rohen JW. Yokochi C Color Atlas of Anatomy 1988 C5 T4

Unco- vertebral cleft Taylor

Lenerdene Levesque BSc.P.T., MCLsc, FCAMPT Thoracic Spine Anatomy and Biomechanics Level III

Thorax – arthrology Thorax - arthrology Facet Joints ! Zygapophyseal joint ! Plane of the facet joints – o flat, nearly vertical " Superior articular facets are slightly convex, 60 from the horizontal and 20o from the frontal ! The superior face backward, " Inferior articular facets are slightly concave, face slightly superior and anteriorly slightly inferiorly and medially lateral as their slope

undergoes a gradual change from the cervical spine

Rohen JW. Yokochi C Color Atlas of Anatomy 1988

Arthrology – zygapophyseal joint Typical Thoracic Vertebra

! Z joint is gently convex in both the transverse and sagittal planes ! This orientation permits multidirectional movement

McMinn RMH. Hutchings RT. Color Atlas of Human Anatomy 1985

Lenerdene Levesque BSc.P.T., MCLsc, FCAMPT Thoracic Spine Anatomy and Biomechanics Level III

Costovertebral Joints Rib - Joints

Costovertebral joints

Costotransverse joints

Rohen JW. Yokochi C Color Atlas of Anatomy 1988 Grays Anatomy

Ribs 2-9 articulate with the vertebral body of their Arthrology – Costovertebral Joint level, IVD and the vertebral body of the level above

Head of Head of rib rib

disc AC Joint cavity FC disc Vertebral body Taylor Taylor

Lenerdene Levesque BSc.P.T., MCLsc, FCAMPT Thoracic Spine Anatomy and Biomechanics Level III

Thorax – arthrology Thorax - arthrology Costovertebral Joint

! Radiate ligament " Superior, ! Stabilized by the intermediate and capsular , radiate and inferior bands attach intra-articular to the vertebral body above and below and to the IVD

Thorax - arthrology

! Intra-articular ligament ! " Only from those between ribs articulating with an oval facet on the two vertebral transverse process bodies and facet on the " Attaches from the tubercle of the rib crest between the demi-facets and the ribs Grays Anatomy McMinn RMH. Hutchings RT. Color Atlas of Human Anatomy 1985

Lenerdene Levesque BSc.P.T., MCLsc, FCAMPT Thoracic Spine Anatomy and Biomechanics Level III

Costotransverse Joints Costotransverse Joints - Ligaments

! Upper 6 ribs – articular surfaces are curved ! Interosseous Ligament ! Lateral Costotransverse ! Lower 6 ribs – flattened or planar Ligament

Grays Anatomy

Costotransverse Joints Blood Supply

! Superiorly supplied via the anterior spinal and paired posterior spinal ! Augmented throughout course via medullary feeders ! Larger Artery of Adamkiewicz (T9) Rohen JW. Yokochi C Color Atlas of Anatomy 1988 Superior

Lenerdene Levesque BSc.P.T., MCLsc, FCAMPT Thoracic Spine Anatomy and Biomechanics Level III

Blood Supply

Note the supply to the nerve root and feeder supply to the cord Intra canal tumour Rohen JW. Yokochi C Color Atlas of Anatomy 1988

Neurology of the Thoracic Spine Sympathetic

! Sinuvertebral nerve – supplies the , epidural blood vessels, PLL, and the posterior portion of the ribs ! Dorsal rami – supplies the posterior thoracic muscles, Z joints and the costotransverse jts. ! – anterior aspect of the ribs ! Innervation of the disc is not well understood

Butler D. Mobilisation of the Nervous System 1991

Lenerdene Levesque BSc.P.T., MCLsc, FCAMPT Thoracic Spine Anatomy and Biomechanics Level III

Local System Anatomy – Force Closure

! Maintain low force continuous activity in all spinal positions and during all directions of motion ! Control of angular and translatoric motion especially in the neutral zone ! Anticipatory action prior to loading Local System Global System

Hodges

Global System

Multifidus

! Action is direction specific – especially active during rotation Levator Costarum breves ! Generate torque and control motion concentrically, isometrically and eccentrically Rotatores thoracis Levator Costarum longus

Primal Pictures

Lenerdene Levesque BSc.P.T., MCLsc, FCAMPT Thoracic Spine Anatomy and Biomechanics Level III

Iliocostalis thoracis

Thoracic component of longissimus thoracis

Primal Pictures

Osteoporosis: Loss of Osteoporosis bone Predominantly affects post-menopausal density! women and generally affects men about a decade later. ! Increased Central collapse The x-ray shows collapse of the concavity! of the end plates vertebral endplates with marked ! Marked central increase in endplate concavity or loss porosity of the of vertebral height. Loss of vertebral bodies The decreased bone density of the height! ! Biconcavity of the internal cancellous bone contrasts with vertebra – fish the preservation of the peripheral mouth vertebra compact shell.

Adequate exercise, calcium & Bullough PG.Boachie-Adjei O. Atlas of Spinal Diseases 1988 hormones can prevent it Taylor

Lenerdene Levesque BSc.P.T., MCLsc, FCAMPT Thoracic Spine Anatomy and Biomechanics Level III

Osteoporosis – Risk Factors Canadian Guidelines for Osteoporosis 2002 Metastases

Major Risk Factors Minor Risk Factors • Age > 65 • RA • Vertebral compression fracture • Past history of clinical Cancer can reach vertebral hyperthyroidism • Fragility fracture after age 40 bodies through segmental veins, • Chronic anticonvulsant • Family history of osteoporotic therapy which connect through the IV fracture • Low dietary Ca intake foramen with the internal • Systemic glucocorticoid vertebral venous plexus and the therapy of > 3 months • Smoker • Malabsorption syndrome • Excessive alcohol intake basivertebral veins. The vertebral • Primary hyperparathyroidism • Excessive caffeine intake veins are valveless and blood can • Propensity to fall • Weight < 57 kg. flow in any direction (according to • Osteopenia apparent on x-ray • Weight loss > 10% of weight local pressures). at age 25 • Hypogonadism • Chronic heparin therapy • Early menopause (before age 45)

Taylor

Metatastic Tumours Malignant melanoma

! 60 year old male In the absence of marked with a primary bone production or bone carcinoma of the destruction, extensive colon metastatic disease may be present without any obvious ! total collapse of the radiographic changes. body of T9

Bullough PG.Boachie-Adjei O. Atlas of Spinal Diseases 1988 Bullough PG.Boachie-Adjei O. Atlas of Spinal Diseases 1988

Lenerdene Levesque BSc.P.T., MCLsc, FCAMPT Thoracic Spine Anatomy and Biomechanics Level III

Metastases – Thoracic Spine Ankylosing Spondylitis

Metastatic tumour T6 Multiple metastases Bullough PG.Boachie-Adjei O. Atlas of Spinal Diseases 1988

DISH – Diffuse Idiopathic Skeletal DISH Hyperostosis

! Cortical hyperostosis ! Ligamentous ! Intact vertebral end without plates significant disc disease ! Normal disc height ! Usually is manifest in ! Flowing ossification of older males and clinical the A.L.L. symptoms are ! Absence of facet or SI generally mild joint involvement Bullough PG.Boachie-Adjei O. Atlas of Spinal Diseases 1988

Bullough PG.Boachie-Adjei O. Atlas of Spinal Diseases 1988

Lenerdene Levesque BSc.P.T., MCLsc, FCAMPT Thoracic Spine Anatomy and Biomechanics Level III

Thoracic injuries: Scheurmann’s Disease

In flexion or axial compression vertebrae are injured more often than discs In order of severity ! endplate fracture ! bone bruising ! wedge compression ! burst fracture Bullough PG.Boachie-Adjei O. Atlas of Spinal Diseases 1988 In upper thoracic extension, thoracic facet injuries are almost as common as cervical facet injuries

An endplate fracture of T1 with bleeding Axial compression with bone bruising from a fall (32M) into adjacent disc T3-9 close-up of T6 bone bruising+ endplate #

#!

T6!

Bone bruising

Normal marrow

Taylor Taylor

Lenerdene Levesque BSc.P.T., MCLsc, FCAMPT Thoracic Spine Anatomy and Biomechanics Level III

T1-2 fracture dislocation: Wedge Compression Fractures severe extension injury (49 male) upper thoracic injuries often resemble lower cervical injuries

avulsion Articular Taylor T7 fracture cartilage 41 male injury

Taylor

Extension injuries to upper thoracic facet joints Thoracic Spine in MVAs Biomechanics

T2-3 facet tip fracture: extension of T2 against shelf of lamina below

T2-3 facet tip injury in 17F partial AC separation: AC fragment & torn capsule!

Taylor

Lenerdene Levesque BSc.P.T., MCLsc, FCAMPT Thoracic Spine Anatomy and Biomechanics Level III

Degrees of Freedom Flexion - osteokinematics 1. Flex/Ext: 2-6 per joint (less in upper and greater in the lower thorax) ! Vertebral segment 2. Side flexion: 3-6 " Anterior sagittal rotation coupled with anterior translation (.5mm) and 3. Rotation: 6-8 per joint (rotation range slight distraction reduced in lower thorax)

Flexion – arthrokinematics (spinal) Flexion – arthrokinematics (costal)

! Zygapophyseal joints Vertebrosternal region " Costotransverse joint " Inferior facet of the ○ Concave/convex superior vertebrae ○ Superior glide of the glides superoanteriorly tubercle of the rib along the plane of the " Costovertebral joint facets ○ Spin with an anterior roll

Lee, D. The Thorax An Integrated Approach 1994

Lee, D. The Thorax An Integrated Approach 2003

Lenerdene Levesque BSc.P.T., MCLsc, FCAMPT Thoracic Spine Anatomy and Biomechanics Level III

Flexion – arthrokinematics (costal) Extension - osteokinematics

Vertebrochondral ! Vertebral segment " Costotransverse joint " Posterior sagittal ○ planar rotation coupled with ○ posterosuperomedial posterior translation glide (1mm) and slight distraction

Lee, D. The Thorax An Integrated Approach 2003

Extension - osteokinematics Extension - arthrokinematics

! Zygapophyseal Joint ! Costal Region " Inferior facets of the " Posterior rotation superior vertebra glides inferoposteriorly along the plane of the facets

Lee, D. The Thorax An Integrated Approach 1994 Lee, D. The Thorax An Integrated Approach 2003

Lenerdene Levesque BSc.P.T., MCLsc, FCAMPT Thoracic Spine Anatomy and Biomechanics Level III

Extension - arthrokinematics Extension - arthrokinematics

! Vertebrosternal region ! Vertebrochondral region " Posterior rotation of the rib results in an inferior glide of the tubercle of " Anterolateral inferior the rib at the glide of the tubercle costotransverse joint of the rib along the plane of the TP

Lee, D. The Thorax An Integrated Approach 2003 Lee, D. The Thorax An Integrated Approach 1994

Lateral Bending - osteokinematics Lateral Bending - ostoekinematics

! Theory ! Theory " As the thorax side flexes " In the vertebrosternal to the right, the ribs on the region this creates a right approximate and on the left separate relative superior glide of the tubercle of the right

rib and a relative inferior " Costal motion stops first and the thoracic vertebra glide of the left rib continue to side flex to the " The effect of this motion right is to rotate the vertebal body contralaterally Lee, D. The Thorax An Integrated Approach 1994

Lee, D. The Thorax An Integrated Approach 2003

Lenerdene Levesque BSc.P.T., MCLsc, FCAMPT Thoracic Spine Anatomy and Biomechanics Level III

Lateral Bending - osteokinematics Lateral Bending - arthrokinematics

! Zygapophyseal joint ! In the vertebrochondral " The left inferior articular facet region the pattern of of the superior vertebra movement coupling is glides superomedially and either ipsilateral or the right inferolaterally contralateral dependent on the movement pattern ! Costotransverse joint

" Left tubercle glides inferior Lee, D. The Thorax An Integrated Approach 2003 " Right tubercle glides superior

Thoracic Rotation Rotation - osteokinematics

! Clinically observe rotation / side flexion occur to the same side ! Experimentally the side bending was inconsistent ! Rotation was coupled with contralateral translation

Lenerdene Levesque BSc.P.T., MCLsc, FCAMPT Thoracic Spine Anatomy and Biomechanics Level III

Rotation - osteokinematics Rotation - osteokinematics

! Theory " The coupled contralateral translation tightens the ligaments of the costotransverse joint

" Further right rotation of the superior vertebra ! Lee, D. The Thorax An Integrated Approach 2003 occurs as the superior Theory vertebra tilts to the right " right rotation of the superior vertebra pushes the superior along the aspect of the head of the left rib forward at the costotransverse joint costovertebral join inducing anterior rotation of the left rib Lee, D. The Thorax An Integrated Approach 2003 and posterior rotation of the right

Rotation - arthrokinematics Vertebrosternal Right Rotation

" Zygapophyseal ○ Ipsi - inferior glide ○ Contra – superior glide " Costotransverse ○ Ipsi – inferior glide ○ Contra – superior glide " Costovertebral ○ Ipsi – posterior roll

○ Contra – anterior roll Lee, D. The Thorax An Integrated Approach 2003

Lee, D. The Thorax An Integrated Approach 1994

Lenerdene Levesque BSc.P.T., MCLsc, FCAMPT Thoracic Spine Anatomy and Biomechanics Level III

References:

McMinn RMH. Hutchings RT. Color Atlas of Human Anatomy Year Book Publishers Inc. Chicago 1985 Bullough PG. Boachie-Adjei O. Atlas of Spinal Diseases J.B. Lippincott Company Philadelphia 1988 Lee D. The Thorax An Integrated Approach Diane Lee Physiotherapist Corporation 2003 Butler D. Mobilisation of the Nervous System Churchill Livingstone Melbourne Edinburgh London 1991 Panjabi MM. Brand RA. White AA. Mechanical Properties of the human thoracic spine. JBJS 1976;58A:642 Rohen JW. Yokochi C. Color Atlas of Anatomy Igaku-Shoin New York Tokyo 1988

Lenerdene Levesque BSc.P.T., MCLsc, FCAMPT