LAB 2
MUSCULOSKELETAL SYSTEM


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Objectives

1. Define a fracture. Differentiate between open and closed fractures in terms of initial injury, treatment and likely complications.

2. Define bursitis, gout, osteoporosis, malunion, scoliosis, kyphosis, lordosis.

3. Distinguish between rheumatoid arthritis and osteoarthritis (degenerative joint disease).

4. Know all underlined terms and all starred * questions.

SPECIMENS, MODELS AND ORTHOPEDIC DEVICES
Go to Specimen Photo Index

Vertebrae with Osteoarthritis (Degenerative Joint Disease) and Osteoporosis

Compare the diseased vertebrae with a normal vertebra. The surface of the normal vertebra is smooth whereas the surface of the osteoarthritic vertebrae is rough with protrusions of bone matrix called osteophytes. This excess bone limits the range of movement and causes pain.(Fig. 70-2, p. 1038)

                39. Vertebrae, degenerative osteoarthritis, gross  
                40. Vertebrae, degenerative osteoarthritis, gross  
                Femoral head, osteoarthritis, comparison of normal to abnormal articular cartilage, gross [XRAY]  
                Osteoarthritis, of knee radiograph [PATH] 
                Foot with "hammer toes", gross  
                Foot, degenerative osteoarthritis, gross [XRAY]  
                Osteoarthritis, hands, radiograph [PATH]  
                Osteoarthritis, hand, radiograph  
                Osteoarthritis, hand, with joint subluxation, radiograph  
                Osteoarthritis, knee, with joint subluxation, radiograph  

In addition, note the eroded body (centrum) of one of the osteoarthritic vertebrae. This damage is due to osteoporosis, a loss of bone density which causes bones to become weak and easily fractured. This vertebra shows a compression fracture, the centrum has collapsed under the normal weight of the vertebral column.
            Bone density and osteoporosis, diagram [XRAY]  
             1. Normal vertebral bone, gross.  
             2. Normal vertebral bone, gross.  
             3. Normal vertebral bone and marrow, low power microscopic. *
             4. Normal vertebral bone, polarized, medium power microscopic. *
             5. Vertebral bone with osteoporosis, gross.  
             6. Vertebral bone with osteoporosis and compressed fracture, gross.  
             7. Vertebral bone with osteoporosis, low power microscopic. *
             41. Vertebrae, osteoporosis, gross  
             42. Vertebrae, compressed fracture, gross [MRI]  

* Osteoporosis is most common in older women. Why? (p. 963)

Malunions of the Femur and Fibula, (p. 1027-1028)

A malunion occurs when a fracture has healed in an inappropriate or twisted position. This can result from improper reduction (bone is not set properly) or abuse of the bone during the period of healing (inadequate retention of reduction). In many cases, such as the 2 bones here, excessive bone growth will occur at the fracture site. Compare the abnormal bones with their normal counterparts.

Herniated Disc - Model and Diagram (pp. 816-819)

In a herniated (or slipped) intervertebral disc, the jelly-like center ruptures through the fibrous capsule. Notice how the ruptured disc is pressing on a spinal nerve, which can cause severe back pain. This is one of the most common causes of back pain. It often occurs in later life because the fibrous capsule dries out and becomes more brittle with age.

What treatments are commonly used for a herniated disc? (pp. 818-819)
            Herniated intervertebral disc, sagittal view, MRI scan  
            Herniated intervertebral disc, transverse MRI scan   

Orthopedic Surgical Devices , Hip and Knee Chart (p. 1039)

Compression hip screw and hip nail are used to hold the head and shaft of a fractured femur in place (Top right of Hip and Knee Chart). Metal rods are used to support fractured diaphysis of long bones such as femur. Femoral-head replacement is used to substitute for an extensively damaged femoral head (Upper right of Hip and Knee Chart, see also the photo of a radiograph of a total hip replacement).

WALL CHART

Fractures of clavicle and acromion of scapula

These fractures are commonly caused by falls where much of the force from the weight of the body is applied to the shoulder. They heal rapidly and usually do not require a cast.

        Normal bone
        1. Normal vertebral bone, gross.  
        2. Normal vertebral bone, gross.  
        3. Normal vertebral bone and marrow, low power microscopic. *
        4. Normal vertebral bone, polarized, medium power microscopic. *
        Fractures
        3. Fracture with new woven bone, high power microscopic *
        4. Fracture with new woven bone, medium power microscopic *
        5. Fracture callus, high power microscopic *
        Pathologic fracture of humerus, radiograph [CT, NM]  

* What is a fracture? (p. 1025)

Osteomyelitis of Humerus

Osteomyelitis is an infection of a bone. It may result as a complication from a fracture or from bacteria spreading to the bone from some other area of the body.
        Humerus, compound fracture, gross [XRAY]  
        Osteomyelitis, foot, radiograph 
        Osteomyelitis, great toe, radiograph 
        Osteomyelitis, great toe, nuclear medicine scan 
        Osteomyelitis, tibia, radiograph 
        Osteomyelitis, vertebra, MRI scan 
        Osteomyelitis, vertebra, MRI scan 
        Osteomyelitis, vertebra, MRI scan  
        6. Chronic osteomyelitis, medium power microscopic *

* Why is osteomyelitis a serious problem? (p. 1027)

Dislocation of shoulder, Torn shoulder capsule (pp. 1030)

Dislocation of the shoulder often accompanies fractures of the clavicle or acromion process because it too is caused by severe blows to the shoulder. Forces causing excessive movement of the upper arm beyond its normal range of motion are also common causes. Dislocation may be a serious injury since it can easily lead to complications such as damage to the nerves and blood vessels passing through the joint. These structures are vital to the health of the arm.

Another complication of shoulder dislocation is tearing of the shoulder capsule. This capsule provides the main structural support for the shoulder joint. Should it be damaged, surgical repair and artificial supports are often needed.
        Rotator cuff injury, MRI scan  

* What is the difference between dislocation and subluxation? (p. 1028)
        Osteoarthritis, hand, with joint subluxation, radiograph  
        Osteoarthritis, knee, with joint subluxation, radiograph  

* What complications often occur after dislocation injuries? (p. 1028)

Bursitis of the shoulder

Bursitis is inflammation of a bursa (a fluid-filled sac between soft tissues or between soft tissue and a bone). Bursae are often found near joints where they serve to cushion and reduce friction.
        Bursitis of elbow, radiograph  

Rheumatoid Arthritis and Osteoarthritis

Arthritis is a general term meaning inflammation of a joint. Note that in rheumatoid arthritis, the joint has swollen soft tissues while in osteoarthritis, excess bone tissue is present in the joints. 

           Rheumatoid arthritis
          
46. Hand, rheumatoid arthritis, gross  
           Rheumatoid arthritis, hand, radiograph  
           47. Elbow, rheumatoid nodule, gross  
           49. Rheumatoid arthritis, rheumatoid nodule, microscopic *
           48. Rheumatoid arthritis, pannus in joint, microscopic *

           Osteoarthritis
          
39. Vertebrae, degenerative osteoarthritis, gross  
           40. Vertebrae, degenerative osteoarthritis, gross  
           Vertebrae, degenerative osteoarthritis, gross  
           Vertebrae, degenerative osteoarthritis, gross  
           Femoral head, osteoarthritis, comparison of normal to abnormal articular cartilage, gross [XRAY] 
           Foot with "hammer toes", gross  
           Foot, degenerative osteoarthritis, gross [XRAY]  
           Hand, degenerative osteoarthritis, gross [XRAY]  
           Osteoarthritis, hands, radiograph [PATH]  
           Osteoarthritis, hand, radiograph  
           Osteoarthritis, hand, with joint subluxation, radiograph  
           Osteoarthritis, knee, with joint subluxation, radiograph  

* Which joints are most commonly affected by rheumatoid arthritis? By osteoarthritis? (pp. 1037, 1041)

RADIOGRAPHS AND PHOTOGRAPHS
Go to X-ray Index
 
Go to Photo Index

Radiologic images of lesions involving bone and joints 

Fractures
- radiographs # 1-10, 14, 15

Examine these radiographs and try to find the fracture(s) present in each case.
            Fracture and ORIF repair of humerus, radiograph [PATH] 
            Fracture, femur at hip joint with prosthesis, radiograph 
            Hip joint with prosthesis, pelvic CT scan 
            Fracture-dislocation of sacroiliac joint, pelvic CT scan 
            Fracture of 5th metacarpal of hand, radiograph [PATH] 
            Linear fracture of skull, radiograph [PATH] 
            Skull fractures, head CT scan 
            Fracture, femur, radiograph  
            Intertrochanteric fracture, femur, radiograph 
            Comminuted fracture, femur, radiograph [PATH] 
            Comminuted spiral fracture, femur, radiograph 
            Comminuted spiral fracture, tibia, radiograph  
            Tibia and fibula fractures, healing, radiograph 
            Tibia, healing fracture, CT scan 
            Fracture, healing, tibia, radiograph 

Hip Fractures and Treatment - radiographs # 11,12, & 13

First examine radiograph #12 of a normal hip. Notice the density of the os coxae (hip bones) and the 2 femurs. (The denser the bone the lighter it appears on X-ray). Next examine the fractured femur in rad. # 13; the head of the femur is completely broken off. Note also the density of the hip bone and femur by comparing this radiograph with #12.

* What disease is likely responsible for the decrease in density of the bones in rad. #13?

Now examine radiograph #11. The fractured femur has been repaired and stabilized with the insertion of pins into the head of the femur.

Note (on rad #11) the fracture on the opposite femur and the density of these bones. This patient also has osteoporosis, which is common in elderly patients and a common cause of hip fractures. Another method of treating such fractures is by a "total hip replacement" in which the head of the femur is replaced by a prosthesis (orthopedic device). Be sure to examine these devices on display in today's lab and note the photograph of a radiograph of a total hip replacement.

        Femur, osteoporosis, radiograph  
        Femur, osteoporosis, radiograph [PATH]  
        Humerus, osteoporosis, radiograph  
        Hand, osteoporosis, radiograph  

Curvatures of the Back - photographs and radiographs

Distinguish between scoliosis, kyphosis and lordosis (p. 600 "Thoracic Cage DIsorders" and see lab  photograph). Note the extreme curvature of the back in the patient with kypho-scoliosis (radiograph). Note how this has altered the structure of the thoracic cavity (compare with normal chest film). This condition makes breathing very difficult for the patient. If diagnosed early (before puberty), scoliosis may be treated effectively by a Milwaukee brace. This brace is worn 23 hrs per day until the patient has stopped growing. If treatment is not successful or if the diagnosis is not made until later in life, scoliosis may be treated with surgical implantation of surgical steel rods (as in the photograph).

           Vertebral abnormalities, table 
           Vertebrae, scoliosis, gross [CT]  
           Scoliosis of vertebral column, axial view, abdominal CT scan  
           Kyphosis of vertebral column, lateral chest radiograph  
           Kyphosis of vertebral column, chest CT scan  
           T-spine kyphosis with compressed fractures, MRI scan [PATH]  

Gout - photograph of foot and radiograph (pp. 1054-1056)

Notice the redness and swelling of the foot, especially of the big toe. Note in the radiograph, the inflammatory reaction occurring within this joint. This is a common site for gout to occur.
           53. Foot, gout, gross  
           Gout, big toe, radiograph  
           54. Gouty arthritis, radiograph  
           Gout, hand, radiograph 
           55. Gouty tophus in soft tissue, medium power microscopic *

* What is responsible for gout? (pp. 1054-1056) 
          56. Gouty arthritis, joint fluid, polarized, microscopic *

8Copyright 2001 - Augustine G. DiGiovanna - All rights reserved.

This material may not be reproduced or distributed in any form or by any means, or stored in any data base or retrieval system without prior written permission is obtained from Augustine G. DiGiovanna, Ph.D.,  Professor of Biology, Salisbury University, Salisbury, MD  21801.