Anatomy of Back PDF

Anatomy of Back Prof.Dr Fadi Hadidi,MD,AFRCSI Professor of Orthopaedics and Spine Surgery 7 Cervical 12 Thoracic 5 Lumbar 5 Sacrum Our vertebral column consist of multiple bony segments called vertebrae, in between these bony pieces there is intervertebral disc. If the bones touch each other with ti...

Anatomy of Back Prof.Dr Fadi Hadidi,MD,AFRCSI Professor of Orthopaedics and Spine Surgery 7 Cervical 12 Thoracic 5 Lumbar 5 Sacrum Our vertebral column consist of multiple bony segments called vertebrae, in between these bony pieces there is intervertebral disc. If the bones touch each other with time we will have distraction and injury, intervertebral discs act as pillow ( shock absorber), reduce the tension and compression on bones so reduce the injury in vertebral column. Usually we have 33 vertebrae , there names are given according to their place , in neck they called cervical vertebra, in thoracic ( thoracic vertebra) , in abdomen (lumber vertebra) , in pelvis (sacral & coccygeal vertebra). Alignment of the vertebral column of the human has a very peculiar alignment that doesn’t exist in any species in mammalian. Anterior or posterior view of vertebral column we will see it straight, but medial or lateral view we will see multiple curves. Our vertebral column is straight because the main function of the vertebral column is to keep the head central over the pelvis so that the right side of our body is symmetrical to the left side otherwise the brain will feel there is something abnormal so it will try to do compensation. We always stay under the effect of gravity and that’s why the spine in medial to lateral view isn’t straight, the convexity of the curve anterior called lordosis , the convexity of the curve posterior called kyphosis. We have cervical lordosis and lumbar lordosis, thoracic kyphosis and sacral kyphosis ,so 50% of our spine is kyphosis the other 50% is lordosis. If we put the gravity line on the spine we will notice that it’s anterior in area of kyphosis and posterior in area of lordosis so most of our vertebral column is away from the effect of the gravity, if we where under the effect of gravity all the time we will have destruction , our bone will be weak with time. However , in some areas the vertebral column is still touching the gravity line (C1,T1, L1, S1) and these areas are the most viable areas to destruction. The functional unit of the vertebral column is called segment ( two vertebra & intervertebral disc between them ) as if we have multiple joints along the vertebral column, that give the vertebral column a very wide range of motion ( flexion, extension, bending ,rotation and complex motion like bending and flexion at the same time ) we don’t have other part of body that gives this widening of mobility like the vertebral column. Mobility inversely related to the stability , as stability increases the mobility decreases sacral joint is immobile joint and that’s why it’s a very stable joint , it holds the whole trunk. As mobility increases the stability decreases so more chance for injury. collectively-- LARGEROM flex/ ext L-Rrotation L-Rlateralflexion 9 · This baby has a problem in sternocleidomastoid muscle , his head is shifted, the left sternocleidomastoid is shorter than the other one this disease called torticollis , his face is asymmetrical. The head should be central over the pelvis to have symmetry between the left and the right. If the head is deviated to one side so the gravity line is shifted to that side, any area exposed to high gravity the oranges don’t grow , his left eye is smaller than the right also the check and mouth. If this condition not corrected (return the head central over the pelvis) he will complete his life with facial asymmetry between the right and the left. This female has a condition called Scoliosis ,the spine is deviated to one side , her right shoulder is higher than the left , the ribs on the right side is well developed, while they’re under developed on the left. In the previous slide, the picture on the right is after the correction of scoliosis , so the vertebral column became straight as much as we can. Ankylosing spondylitis Clinical features – Kyphotic posture When the patient has arthritis all the vertebral region became kyphosis , and this kyphosis will increase gradually over time so the patient is unable to extend his back , with time he will have a problem vision , respiration, eating and drinking. Types of vertebrae 1- typical a-body b-arch All vertebrae that has body and arch is called typical vertebrae, and any vertebrae that doesn’t have arch or body or contain additional structure or fused those are called atypical vertebrae 2- atypical additional structures fused All these vertebra have body & arch so they’re called typical vertebrae. The first vertebrae here has two arch without body (atypical vertebrae), the second has body and arch with accessory process the dense ( atypical vertebrae), the last one the coccygeal bone all of the have body without arch (atypical vertebrae) The sacrum has body and arch but it’s fused ( atypical vertebrae). typical vertebrae Typical vertebrae Consists of body and arch - Body : anterior, bigger than the arch (why: because body of the vertebrae is carrying 70%of the load of the body) * Size of the vertebrae increases as we go downward cervical < Thoracic < lumbar (cervical: carries the head , thoracic: carries the head + chest, lumbar: carries the whole body) * Usually 70% of the load carried on the body of the vertebrae (70%anterior) and 30% is carried on the arch (30%posterior) - Arch : posterior , consists of 2 bone called lamina, these 2 bone diffuse together to give us the spinous process, and there is a transverse process We have these process (spinous + transfer) for the attachment of the ligament and the attachment of the muscle origin The bone that connects between the body and the arch is called pedicle(very strong, the strongest part of the vertebrae) Pedicle + arch they form together the Spinal canal (the circle in the middle) the spinal cord and nerves passes through the canal and it protects these nerves and spinal cord to prevent injuries from occurring How to distinguish a vertebrae: there are a specification for each vertebrae - cervical vertebrae: small body size(smallest size ), oval in shape , spinous process is short and bifid (bifid: something that is divided or cleft into two equal parts or lobes, looks like a (V)) - thoracic vertebrae : medium body size, heart shape , spinous process long and thin - Lumber vertebrae: large body size (largest size ) , kidney shape , spinous process short and thick also Sacral consisting of body and arch The most important feature is that they are fussed together That’s why we consider them as atypical vertebrae Coccygeal bone : body of the vertebrae Attached to each other These are also Atypical vertebrae Epi view Size increase as we go downward Pedicle Spinous process Arch Here in the x-ray we should see many things: 1- size of the vertebrae increase as we go downward 2- spinous process it must be located in the midline 3-arch (not present in everyone. We call it spina bifida 4-pedicle (look like circles\eyes) Lateral view: Body of the vertebrae rectangular in shape All of the vertebrae must be positioned on same line and the size of the vertebrae increase as we go downward If we have a patient falling down and I took an x-ray like this slide we will see 1- shape not rectangle 2- the size of the vertebrae is smaller than the vertebrae above So here we have a problem called fracture So this patient has vertebrae fracture 70% of the load of the patient is carried on the body of the vertebrae. But in this case we have fractures so the vertebrae will not be able to carry this load 70%. However it carries about 50-60% So, what do we do in this case? I have to restore the load again at the same time I have to increase the load of the arch (so that it'll be able to carry more) Because we know that the arch carries 30% So we need to bring back the integrity of the vertebrae as much as I can In such a case we placed screws anteriorly to increase the load of the arch posteriorly So, we added artificial bone inside the vertebrae so that the vertebrae will be able to restore it's integrity and the patient will be able to move and walk, and the 70%load to return on the body of the vertebrae However in this case the vertebrae will be completely destroyed. Here we lost all of the 70% on the vertebrae It is in the wrong place, it is going into the canal And it is pressing on spinal cord In order for the patient to get better i must remove what is pressing the spinal cord. So, I must remove the whole vertebrea from its place. This is the only way to treat such a condition. Remove the hole vertebrae and to replace by artificial vertebrae. Vertebral Articulation Superior articular process each articulation is a fully encapsulated synovial joint these are often called apophyseal joints Inferior articular process Note: the processes are bony outcroppings. 29 If we look laterally to vertebrae we will see 2 process One process superior we called superior articular process another inferior called inferior articular process Each vertebrae has one process superior and once inferior Usually the superior of the vertebrae articulate with the inferior with that of the one vertebrae above On another hand the inferior of the vertebrae articulate with the superior of the vertebrae inferior So, they will form something called Apophysealjoints (facet joints) Now, these joints will be the same as any joint that we have, it will have a synovial fluid capsule… arthritis, hematrophyarthritis , osteoarthritis could develop in these joints Patient could complain and suffer from Severe pain related to the arthritis in facet joints. So we try to manage them versatility by some medication or by physiotherapy, but some times we have to deliver medication inside the joint (steroid injection inside the joint) [why steroids: because it act as anti inflammatory medication so it’s very important to localized the facet joint] So I put the injection then I put a dye to be sure if I was inside the joint When I am sure I will inject steroid inside the joints. To be able to perform this I must understand the anatomy for facet joints Muscles of back 1 superficial muscles * ass with shoulder girdle *Ttrapezius, latissimus dorsi, levator scapulae 2 intermediate muscles * ass with respiration * serratus post sup , serratus post inf We said that the problem with the vertebral column is that Its vibration is high and the stability is low So it is more prone to injuries (but that doesn't mean that every tiny fall leads to injuries due to the very huge number of muscles around the back ) We have 3 layers of muscles around the back (3 groups) : 1. Superficial groups 2. Intermediate groups 3. Deep groups The anatomist usually classified the muscle function according to origin and insertion If the orgin and the insertion are at the same place then then it is said that they work on that place But, if the orgin and the insertion are in different places then they share their function with more than one area of the body So for example, superficial muscles work on the back and they also work on different places for example trapezius and latissimus dorsi they are working in the back but the same time they are working on the shoulder That’s why we don’t consider them the main stabilizers for spine Intermediate also work on the back and the same time on the respiration. 3- Deep musclesPosterior Muscular Support primarily produce extension and medial/lateral flexion Superficial to deep – erector spinae – semispinalis – deep posterior The most important Also divided into 3 groups Superficial Intermediate Deep Deep muscle are divided based on the origin and insertion. A part of them works from vertebrae to vertebrae, and another part of them work over top three vertebrae, another part works on thoracic vertebrae only. Some alternate between thoracic and lumbar. Some other alternate between servical andthoracic, and so on and so forth Due to their huge number, we 34 them can't memorize Spine Posterior Muscular Support primarily produce extension and medial/lateral flexion Posteriorly – erector spinae iliocostalis longissumus thoracis spinalis 35 spinalis longissimus Erector spinae Versatile muscles that can generate rapid force yet are fatigue resistant iliocostalis cervicis thoracis lumborum 3 6 What's important in these muscles is: 1. They can generate rapid force 2. Resistance to fatigue (because they have a lot of ATP) They give us a high amount of energy and their force is really strong that’s how we are able to stand for a long time (1,2,3hours ) without having back pain Semispinalis capitis cervicis thoracis 37 IT IS intertransversarius interspinales Deep posterior multifidus rotatores 3 8 s T u A D C A E D T N E Thank you M I C s C T E A L M u B