Identifying Musculoskeletal Conditions - NCLEX-PN

Patellofemoral syndrome presents as pain in the front of the knee, sometimes caused by wearing down, roughening, or softening of the cartilage under the kneecap. Osgood-Schlatter disease is a syndrome of irritation of the patellar ligament at the tibial tuberosity, characterized by painful lumps just below the knee, most often seen in young adolescents. Legg-Calvé-Perthes syndrome is due to disruption of blood flow to the femoral head, leading to avascular necrosis. Congenital scoliosis is a spinal deformity characterized by the curving of the spine at an angle greater than 10 degrees on radiography.

Psoriatic arthritis will often show a pencil-in-cup deformity on x-ray. Osteoarthritis will show joint space narrowing, sclerosis, and osteophytes. Rheumatoid arthritis and juvenile rheumatoid arthritis will both show soft tissue swelling, joint space narrowing, and may show marginal erosions.

Swan neck deformity is often seen in patients with rheumatoid arthritis. This is a state in which the distal interphalangeal joint (DIP) becomes hyperflexed (bends toward the palm) while the proximal interphalangeal joint (PIP) is hyperextended (bending away from the palm). Shepherd's crook deformity is seen in Paget's disease of the bone, pencil-in-cup deformity is seen in psoriatic arthritis, and Heberden nodes are frequently seen in the distal phalanges of patients with osteoarthritis.

Duchenne's is the most common and most severe form of muscular dystrophy, accounting for a full 50% of cases of muscular dystrophy in the US. The next most common type is Becker's, followed by myotonic muscular dystrophy and Emery-Dreifuss.

Lambert-Eaton syndrome is a condition of progressive muscle weakness caused by an auto antibodies to presynaptic calcium channels in the neuromuscular junction. This does not allow calcium to enter the presynaptic cell, which is required for neurotransmitter release into the synaptic cleft. Without the release of neurotransmitter, there will be no muscular response. Myasthenia gravis is an autoimmune condition in which antibodies are formed against acetylcholine receptors, and muscular weakness in multiple sclerosis is caused by destruction of myelin in the CNS due to antibodies against oligodendrocytes. Dermatomyositis is an inflammatory connective tissue condition that may be associated with a post-viral autoimmune reaction or triggered by a paraneoplastic syndrome.

Histological findings of dermatomyositis will generally reveal mixed B cell and T cell perivascular inflammatory infiltrate and perifascicular muscle fiber atrophy.

Fibrosed muscle fibers and fatty infiltrates are typical of Duchenne's muscular dystrophy, while granulomas in muscle are rare but may be seen in sarcoidosis and other conditions of granulomatous myositis.

A periorbital heliotrope rash is often seen in dermatomyositis. It is bilateral, symmetric, purpuric, and macular, and erupts over the eyelids and surrounding periorbital area. Malar rash (often called a "butterfly rash") is seen in patients with systemic lupus erythematosus (SLE). Dermatitis herpetiformis is a rash on the elbows and knees generally seen with gluten allergy (celiac disease). Perioral dermatitis is an iatrogenic condition often associated with prolonged use of topical steroid creams.

Polymyositis is characterized by symmetric proximal muscle weakness in the upper and lower extremities, often without the presence of distal muscle weakness. The first sign is often weakness in the thighs while walking, the inability to rise from a seated position without assistance, or the inability to raise the arms above the head.

Dermatomyositis generally includes a characteristic periorbital rash. Weakness is expressed in the neck, arms, and legs. Guillain-Barre syndrome is an ascending paralysis: symptoms start in the hands and feet, then spread proximally as it progresses. Muscular weakness in myasthenia gravis is often especially expressed in muscles of the face and head, especially those that control eye and eyelid movement, facial expression, chewing, swallowing, and speaking.

A rhabdomyoma is a benign tumors of striated muscle. 90% of adult rhabdomyomas present as round masses in the neck.

Paget's disease of bone is a condition characterized by high bone turnover due to accelerated osteoclast and osteoblast activity. This results in increased calcification of bones, especially prominent in the skull, pelvis, femur, and tibia.

Osteogenesis imperfecta is an issue with collagen formation that causes fragile bones and multiple fractures. Multiple myeloma is a malignancy of plasma calls, and giant cell tumors are rare tumors that generally originate from the epiphysis of long bones (with no effect on bone deposition).

Paget's disease of the bone generally presents in after the age of 55, and is very rare in younger individuals. The prevalence in individuals over 55 is as high as 3%.

Osteoid osteoma is a benign, bone-forming tumor characterized by a small area of neoplastic growth surrounded by an area of mature, reactive bone.

Fibrosarcoma, osteosarcoma, and Ewing's sarcoma are all malignancies.

Osteosarcoma is the most common primary malignancy of bone, excluding hematopoietic malignancies, making up approximately 20% of all primary bone cancers.

Fibrosarcoma and Ewing's sarcoma are relatively rare conditions, and osteoid osteomas are is non-malignant.

Roughly 75% of osteosarcomas occur in the distal femur or around the knee. The next most common site is the upper arm. Spinal or pelvic involvement are rare.

The majority of cases of osteosarcoma are in children and adolescents between the age of 10 and 25. It's the most common type of bone cancer in children and young adults, and the third most common cancer in teens.

Dystonia is a condition of sustained muscle contractions causing abnormal posture, twisting, restricted movement, and pain. Torticollis is a form of dystonia specific to the muscles of the neck. Ballismus is a condition of rapid, violent involuntary motions. Geniospasm is specific to the mentalis muscle, causing involuntary movements of the jaw.

Elevation of the limb above the heart may slow arterial perfusion and raise venous pressure, and worsen circulation. Ice may cause vasoconstriction and further lead to circulation compromise. Both of these interventions would not be appropriate for compartment syndrome.

Know the six P's of compartment syndrome: pallor, pain on passive movement, paresthesia, paralysis, pulses, pressure: all of these may be present in compartment syndrome. Pulselessness is an ominous sign of impending permanent damage, the physician should be notified. Muscle damage can lead to myoglobinemia of the blood thereby damaging the kidneys leading to rhabdomyolysis and dark urine. A tight bandage could further increase the pressure in the compartment and should be loosened if this is so.

The correct answer is "costochondritis." Costochondritis is an inflammation of the cartilage that bridges the sternum to the ribs. It is a very common cause of acute chest pain in young, healthy, physically active individuals without known cardiovascular disease. In this case, we have a very prototypical case: a young, physically active (especially with physical activity involving the chest like weight-lifting and rowing crew), otherwise healthy male with focal, reproducible chest pain in the parasternal area, and normal vital signs on presentation. When you see this history, this is a rather convincing case for costochondritis. There is no information given that would seem to indicate a personal or family history of cardiovascular disease, and thus, costochondritis would be the best answer choice. He can be treated conservatively with NSAID's for anti-inflammatory and pain control effects.

Acute coronary syndrome (e.g. myocardial infarction) is very unlikely in this patient as he is young and healthy, has reproducible, focal chest pain, is very physically active, and has stable vital signs. If there was a personal or family history of cardiovascular disease, or any report of recent drug use (particularly cocaine), then this could be higher on the differential.

Pulmonary embolism is very unlikely in this patient as there is no leg swelling reported, the chest pain is focal, the patient is healthy and active, and his vital signs are normal.

Peripheral vascular disease would not present with chest pain, and would be highly unlikely to be present in an otherwise healthy 19-year old.

There is nothing to suggest that this healthy, active 19-year old patient has diabetes mellitus from the information provided.

The correct answer is "ACL, MCL, and Medial meniscus." This is the only answer choice that correctly lists all three components of the "unhappy triad." The unhappy triad is frequently injured in athletes who participate in contact sports, such as football. The injury mechanism often involves a direct, forceful hit to a firmly planted leg. The hit is forceful enough to rupture two ligaments (ACL and MCL), as well as the medial meniscus. The treatment for such an injury involves surgical intervention and a lengthy recovery period, though for patients inclined to partake in the rehabilitation process, they can often return to their desired sports after completion of surgery and rehab.