Free Orthopedics Review | Dr Hutaif General Orthopedics -...

The vertebral bodies grow faster than the spinal cord. A more caudal placement of the conus medullaris is considered normal in an older patient. However, a conus medullaris below L3 at any age is abnormal and may represent a tethered and/or dysplastic cord.

Displacement of the cerebellar tonsils below the foramen magnum is termed a C hiari malfomation. A C hiari I malformation is an isolated malformation; a C hiari II malformation is associated with a syrinx. Symptoms may include headache, vomiting, and nystagmus. Although the normal protrusion allowed decreases with age, 5 mm is abnormal at any age.

With an increase from four to six pins, the load to failure is increased by more than 50%. Additional pins decrease many of the complications, such as loosening and pin tract infection. The risk of dural puncture is not measurably increased because it is a rare complication.

The Bernese (Ganz) osteotomy is contraindicated in patients with open triradiate cartilages because it crosses the cartilage. The procedure is also contraindicated in complete dislocations, incongruous hips, and advanced osteoarthritis with a joint space of 1 mm or less.

The false profile radiographic view assesses anterior coverage and is obtained with the affected hip against the film and the pelvis rotated 65° away from the plane of the film.

The patient has features suggesting mild hemophilia A or B including x-linked inheritance and occasional bleeding episodes. Iliopsoas hematoma is a complication of hemophilia. Bleed into the hip or the lumbar epidural space is less common and there are no signs to suggest infection.

The standard treatment of a psoas abscess is continuous factor replacement. Surgery is usually unnecessary, but it may be considered in cases of acute palsy with severe pain unresponsive to medical therapy. A percutaneous drainage tube is not recommended because the hematoma may be difficult to locate or drain.

Although a spiral fracture is classically consistent with nonaccidental injury, this is not always true. A spiral fracture is often seen in accidental injuries. The location of the fracture in the femur, the socioeconomic status of the family, and the coexistence of other disabilities are all poor predictors. The ability of the child to walk has predictive ability. In one study, nonaccidental injury accounted for 42% of all femur fractures in children before walking age vs. only 2% of fractures after walking age.

Multiple hereditary exostosis (MHE) is inherited as an autosomal dominant condition. There are three genes known to be involved: EXT 1, 2, and 3. EXT 1 and 2 encode glycosyltransferases needed for biosynthesis of heparan sulfate. Fibroblast growth factor receptor is abnormal in achondroplasia.

This patient has an eosinophilic granuloma, which is an isolated form of Langerhans cell histiocytosis. Patients with isolated involvement may be treated with observation, curettage, bone grafting, or steroid injection. For a lesion of this size, the risk of fracture is high and curettage with bone grafting is recommended. C hemotherapy and/or systemic steroids are reserved for patients with systemic disease.

Skeletal survey is the most sensitive means of detecting lesions of eosinophilic granuloma (Langerhans cell histiocytosis). Bone scan detects most, but not all, of the lesions. Some lesions lack enough osteoblastic activity to appear on bone scan. Lesions are not detected on physical exam unless they are large enough to cause pain or tenderness. Indium labeled white cell studies are not used in this condition.

This lesion is most likely to be an osteoid osteoma or an osteoblastoma. The best study to further evaluate the nature and anatomic extent is with computed tomography.
Magnetic resonance imaging may overestimate the lesion because of sensitivity to edema in the marrow and surrounding soft tissue. Bone scintigraphy with or without SPEC T does not provide enough anatomic detail. C oned radiographs do not provide the needed multidimensional detail for this condition, as well as many other spinal problems.

Fibrous dysplasia has been determined to be the result of a postzygotic mutation in the GNAS1 (stimulatory G protein of adenylyl cyclase) gene. All of the cells that are descended from the cell with the mutation manifest features of the disease.
FGFR3 (fibroblast growth factor receptor-3 protein) is abnormal in achondroplasia. FBN1 (fibrillin 1) is abnormal in Marfan syndrome.
C FBA1 is abnormal in cleidocranial dysplasia.
C OL1A1 (collagen, type 1, alpha 1) is abnormal in osteogenesis imperfecta.

Down syndrome is the only condition listed that does not involve congenital contractures.
Amyoplasia (or classic arthrogryposis) involves multiple contractures with normal intelligence and loss of flexion creases. Diastrophic dysplasia is a disorder of cartilage that includes contractures of many joints, as well as epiphyseal irregularity. Popliteal pterygium syndrome includes contractures with webbing across the flexor surfaces of the joints.
Larsen syndrome involves multiple joint dislocations, as well as contractures.

A diastematomyelia is an osseous or fibrocartilaginous septum within the spinal canal that invaginates or splits the neural tissue. A diastematomyelia may or may not be associated with neurologic deficit. Surgical excision is indicated for the presence of symptoms or at the time of spinal deformity correction.

Several series of patients with diastematomyelia have shown the following anatomic distribution: 64% occur in the lumbar spine,
27% occur in the lower thoracic spine, 9% in the upper thoracic spine, and almost none occur in the cervical or sacral regions.

Widened interpedicular distance is the most common finding (94% or greater) in patients with diastematomyelia.
Neurologic deficit is present in 60% to 88% of patients with diastematomyelia.
A cutaneous lesion, such as a dimple or hairy patch, is present in 55% to 79% of patients with diastematomyelia. Anisomelia is present in 53% to 58% of patients with diastematomyelia.
Foot deformities are present in 32% to 52% of patients with diastematomyelia.

Hemiepiphyseodesis is most likely to produce progressive curve correction in patients under age 6. Hemiepiphyseodesis is not likely to result in improvement when there is no concave growth potential, as in the case of a congenital bar. In hemivertebra of the lumbosacral region, improvement is most likely when a hemivertebra resection is performed.

C hildren ages 4 to 8 (40 lbs to 60 lbs) are at risk for airbag injuries and should not be in the front seat. In addition, they require booster seats to allow proper fitting of the shoulder harness on the upper torso. Rear-facing seats are only appropriate for infants. C hildren should not be in the front seat until after age 12 and over 100 lbs.

Acute internal fixation in children has not been shown to provide the same life-saving and morbidity-reducing benefits as in adults. However, it will ease the management of the polytraumatized patient.

Pin fixation of supracondylar humerus fractures in children decreases the risk of compartment syndrome as well as malreduction. Use of medial and lateral pins has been shown to be the most stable construct in biomechanical studies. The use of medial and lateral pins carries a risk of iatrogenic injury to the ulnar nerve. No nerve injuries have been demonstrated after the use of two lateral pins.

The use of medial pins in treatment of supracondylar fractures of the humerus has been associated with a risk of ulnar nerve injury. However, in the largest reported series, 16 of 17 palsies resolved spontaneously and completely with observation after a mean of 18 weeks. There is no evidence that pin removal, exploration, or transposition is necessary at this stage. Hyperflexion in a splint may cause the nerve to be apposed to the pin and can be decreased.

Measurement of congenital scoliosis has an intraobserver variation of 8°. Measurement accuracy decreases with decreased level of training, increased curve size, and decreased clarity of the endpoints. A coned and centered film would give better detail.

The ossification groove of Ranvier contains chondrocytes that provide latitudinal growth of the growth plate. The groove of Ranvier may be thought of as âthe growth ring of the growth plate.â
The chondroepiphysis is the cartilage precursor of the epiphysis. The apophysis is a nonarticular growth region.
The ring of LaC roix is a peripheral structure that reinforces the growth plate. The secondary spongiosa is mature lamellar bone after it has been remodeled.

The lowest pressure of oxygen is in the hypertrophic zone because it is poorly vascularized. This is one of the features that triggers cell death and calcificaton.

The normal lumbar and thoracic vertebrae are comprised of two posterior and one main anterior ossification center. These join at the neurocentral synchondrosis and the midline vertebal ossification center.

The somite is a group of tissues that are bilaterally symmetric and repeated to comprise the axial skeleton. Each somite contains a dermatome, myotome, and sclerotome.

Homeobox genes code for transcription factors involved in regulation of limb genesis in the embryonic period. Homeobox genes have a highly conserved 60-nucleotide sequence.

The proteoglycan aggregation is greatest in the reserve zone and in the epiphysis. Proteoglycan concentration progressively decreases in the direction of the metaphysis. This phenomenon also enables calcification to occur.

Renal failure is associated with the highest risk (90%) of bilaterality. By contrast, idiopathic SC FE has a 20% risk of bilaterality initially and a further 10% to 20% risk until maturity.

This patient has nutritional rickets because of a combination of decreased vitamin D intake and increased need for sunlight due to dark skin. The laboratory findings should include a lowânormal calcium phosphate, elevated alkaline phosphatase and parathryoid hormone, and low vitamin D levels and precursors. Vitamin D supplementation without bracing is adequate treatment.

The dose of acetaminophen should be 10-15 mg/kg. The maximum daily dose should be no more than 75 mg/kg. Larger doses of acetaminophen pose a risk of hepatotoxicity over a long period of time.

Opioids must be used with caution in infants younger than 3 months of age because of decreased clearance and decreased protein binding. This results in greater bioavailability.

The potency ratio of commonly-used drugs is one of the factors that determines the appropriate dose of a drug. The potency ratio of hydromorphone to morphine sulfate is 7-10:1.

Pain measurement is becoming increasingly important for both children and adults. A number scale to quantitate pain can be appropriately used for most children over the age of 7 years. For younger children, the âfaces scaleâ or a finger span scale (stretching the fingers as far apart as possible) is more accurate.

Spasticity is a hallmark of upper motor lesions. Spasticity is characterized by hyperreflexia, clonus, and velocity-dependent resistance. After early childhood, muscle contracture also develops. Writhing movements are characteristic of athetosis, not spasticity.

Botulinum toxin type A acts by blocking the release of acetylcholine at the nerve terminal. Over time, new terminals sprout and the effect is lost. By contrast, alcohol and phenol denature proteins and disrupt nerve conduction.

Baclofen mimics the effect of gamma-aminobutyric acid, an inhibitory neurotransmitter in both the peripheral and central nervous system. Baclofen reduces peripheral spasticity. A major side effect of baclofen is sedation. The ratio of sedation to spasticity reduction may be enhanced by intrathecal administration.

The migration index of Reimers is used to quantitate hip subluxation in cerebral palsy. It is defined as the ratio of the uncovered portion of the femoral head (lateral to a vertical line through the outer edge of the acetabulum) to the total width of the head.

The only absolute indication for preoperative magnetic resonance imaging in idiopathic adolescent scoliosis is an abnormal neurologic exam or abnormal curve pattern.

Although the angle of trunk rotation (ATR) does not convert directly to a C obb angle, there are population-based figures for mean curve at each ATR. The mean C obb angle for curves having a 7° ATR is 20°.

Use of a 5° ATR threshold for detection of curves with a C obb angle over 20° has a sensitivity of 98%, but a specificity of only
64%.

The normal values for kyphosis in the general population (2 standard deviations above and below the mean) are 20° to 50°.

Head injury is the cause of virtually all mortality in children with pelvic fractures. The rarity of life-threatening intrapelvic hemorrhage is in marked contrast to adults. Pulmonary embolism and multisystem organ failure are rare in children.

A childâs pelvis can absorb a significant amount of energy without serious displacement. There is rapid healing and good remodeling potential. Bedrest is the appropriate treatment for this patient because of the low risk of complications.

A positive age-weight test is defined as a patient who is under the 50th percentile of weight for age or older than 16 years of age at presentation with slipped capital femoral epiphysis. These patients should have a workup for underlying renal or endocrine disease. A positive family history is found in 5% to 10% of patients with slipped capital femoral epiphysis.

A grade III slip refers to more than 50% displacement of the epiphysis. Renal failure is associated with the highest risk (43%) of progressing to a grade III slip. Fortunately, these slips are usually stable.

The essential feature of the definition of Klippel-Feil syndrome is congenital cervical fusion. Features other than congenital cervical fusion are sometimes seen but are not essential features of the syndrome. Features other than those listed above include scoliosis in different regions of the spine, congenital heart defects, a short neck, Sprengel deformity, and renal anomalies.

Basilar invagination is extremely rare in this syndrome, and problematic cervical kyphosis is equally uncommon. Atlanto-occipital translation and subaxial instability occur but rarely cause symptoms. Atlantoaxial instability is the most common of the cervical abnormalities listed to cause neurologic compromise in Down syndrome. Nevertheless, surgery is only indicated if the atlantoaxial interval exceeds 6 mm, or causes neurologic deficits.