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

Autosomal recessive conditions classically show âhorizontalâ inheritance. Ancestors do not display the gene because they would likely have only one copy of the mutant allele. Only when two carriers reproduce is the phenotype manifest in approximately one- fourth of their offspring.
Autosomal dominant inheritance is characterized by vertical transmission. Many generations manifest the trait because it takes only a single copy of a mutant allele to display the phenotype.
Sex-linked conditions are often traced back in a family. Normally the males are affected and the females are carriers. Multifactorial conditions are thought to result from the combination of different genes. Although the risk of recurrence in kindred is somewhat greater than the population as a whole, it is still quite low (only a few percent). It is rare for siblings to be affected.
Anticipation refers to the phenomenon in which successive generations are likely to display more severe forms of a given disorder. Myotonic dystrophy is a classic example of this phenomenon.

Two copies of a mutant allele are required to reduce enzyme function to levels that cause clinical impairment.
Enzyme defects are rarely inherited by an autosomal dominant pattern because even half of the normal activity of most enzymes is adequate to maintain normal function.
Enzyme defects are rarely inherited in an X-linked dominant pattern because one copy of a mutant allele is usually sufficient.
Multifactorial inheritance refers to the interaction of multiple, or different genes, to produce a disorder. Enzyme deficiencies are typically the result of a defect in a single gene.
Because enzymes are typically coded by a single gene, they follow mendelian patterns.

Morquio syndrome is a member of the family of mucopolysaccharidoses. Morquio syndrome is a deficiency in the enzyme galactose-6-sulfatase. A deficiency in galactose-6-sulfatase results in increased urinary excretion of keratosulfate.
Alpha-L-iduronidase is deficient in Hurler syndrome.
Beta-glucuronidase is deficient in some rare mucopolysaccharidoses. Fibroblast growth factor receptor protein is deficient in achondroplasia. Sulfate transport protein is deficient in diastrophic dysplasia.

Polymerase chain reaction refers to denaturing DNA, isolating a segment of interest with known primers, and reannealing the strands multiple times to produce exponential copies of a segment.

The term pleiotropy refers to a disease taking different shapes in various patients.
Variation in the severity of a given problem is better termed "variable expressivity." Target joints are not genetically determined.
Hurler syndrome usually not being present in prior generations of an affected patient is an example of autosomal recessive inheritance.
The term pleiotropy refers to a disease taking different shapes in different subjects, whereas the cause of patients with
Ollier disease having more involvement on one side of the body is unknown.

Stiffness and mandibular hypoplasia are fairly common in juvenile rheumatoid arthritis (JRA) due to inflammation of the temporomandibular joint that affects the growth plates of the mandibles.
Basilar invagination is rare in JRA.
Rotatory subluxation of C 1-C 2 is rare in JRA. Subaxial subluxation is rare in JRA.
C ervical stenosis is not a clinical problem in JRA.

Magnetic resonance imaging should be the next step to rule out pyogenic spondylitis.
Ultrasound has not been proven effective in evaluation of anterior spinal pathology.
C omputed tomograms do not have a greater sensitivity than plain films in early diagnosis of infection.
An indium labeled scan may yield diagnostic information but would not be the preferred test because of the time needed and inability to provide other diagnostic information.
Hip arthrogram would not be the next step because the hip range of motion is normal. Even if hip pathology were suspected, the next step would be a plain film and an ultrasound.

A retrospective comparison study has shown no increase of risks in delayed treatment of supracondylar fractures as long as the neurovascular examination is within normal limits.

The distal tibia grows more than the distal fibula.
The anterolateral portion of the tibial physis ceases growing last, thus explaining the phenomenon of the Tillaux fracture. The physis of the distal fibula is always located more distally than the distal tibia.
The two physes are not conjoined.

The majority of children and adolescents do not have an identifiable cause of back pain after all appropriate tests are performed. Many times the diagnosis is "musculo-ligamentous strain." the most common identified cause is spondylolysis.

An early histology confirmed later by a culture is considered the definitive means of diagnosis for active skeletal tuberculsosis.
The tuberculin tine tests do not indicate active disease, only exposure.
Magnetic resonance imaging is not specific for a particular infectious organism.
The enzyme linked immunosorbent assay (ELISA) test is used to diagnose Lyme disease.

The lower thoracic-upper lumbar spine is most commonly affected by tuberculosis. Multiple vertebrae are often involved in tuberculosis spondylitis.

Vertebral destruction exceeds disc destruction in tuberculosis.
Bony changes occur earlier in tuberculosis than in pyogenic spondylitis.
Involvement of multiple contiguous levels is more common in tuberculosis than pyogenic spondylitis.
Bony erosions seen on computerized tomography are large in tuberclosis and small in pyogenic spondylitis. Magnetic resonance imaging often shows significant soft tissue involvement in both disorders.

Anterior debridement, strut graft, and posterior fusion with instrumentation provide the patient with the best chance of a positive result. This procedure minimizes graft dislodgement and posterior overgrowth.
A two-drug therapy alone for at least 6 months leaves the patient at a significant risk of progressive kyphosis and neurologic deficit.
A two-drug therapy for at least 6 months along with a body cast also leaves the patient with significant risk of progressive kyphosis and neurologic deficit.
The lack of anterior support from a two-drug therapy and posterior spinal fusion to prevent deformity leaves the patient with significant risk of kyphosis.
Even with an anterior spinal debridement and a rib strut graft, there is a risk of graft dislodgment over this large defect and of posterior growth into kyphosis.

The dorsal approach has not shown evidence of avascular necrosis, whereas the posteromedial approach has shown such changes at follow-up in as many as 40% of cases.
The dorsal approach requires a less extensive dissection than the posteromedial approach.
The dorsal approach does not require or permit plication of the talonavicular capsule, whereas the posteromedial approach does.
The dorsal approach does not appear to have a higher rate of redislocation of the talonavicular joint than the posteromedial approach.
The dorsal approach requires a shorter tourniquet time than the posteromedial approach.

Patients with cerebral palsy do not have an increased risk of congenital vertical talus, but they may develop an acquired neuromuscular vertical talus.
Patients with myelomeningocele have approximately a 5% to 10% risk of vertical talus, far above that of the general population.
Arthrogryposis is associated with an increased risk of vertical talus.
Nail patella syndrome and Larsen syndrome are associated with an increased risk of vertical talus.

Scoliosis curves are much more likely to begin in the juvenile period than idiopathic scoliosis.
There is no significant difference in the likelihood of left thoracic curves in Marfan syndrome. Brace treatment is less likely to be successful in Marfan syndrome than in idiopathic scoliosis. Marfan patients with scoliosis are more likely to have back pain.
Marfan curves are more likely to progress in adulthood.

Demineralized bone matrix is weakly osteoinductive.
The term osteogenic refers to direct transmittal of cells capable of making bone. Demineralized bone matrix is not osteogenic.
Demineralized bone matrix varies in efficacy between different forms and different methods of sterilization. The term osteoconduction refers to provision of a favorable scaffold and environment for bone formation. Demineralized bone matrix is osteoconductive.

Posterior fusion and instrumentation is the best-documented treatment. Although this form of treatment is followed by an increased incidence of wound healing problems, the problems can be treated.
Observation is not recommended because the curve is highly likely to increase and cause a decrease in pulmonary function.
Bracing has no role in large curves, and it is not known if bracing is successful in Ehlers-Danlos syndrome.
Anterior fusion with instrumentation would be difficult with a double curve. Anterior fusion carries an increased risk due to vascular fragility. It is not necessary because there is no increased risk of crankshaft or pseudarthrosis.
There is no particular reason for adding an anterior procedure in this situation in view of the vascular risk.

Scoliosis in osteogenesis imperfecta (OI) is due primarily to ligamentous laxity.
Scoliosis in OI is due primarily to ligamentous laxity, not bony fractures. There is no association between brainstem impression and scoliosis. Scoliosis in OI rarely responds to brace treatment.
Scoliosis, when present in OI, is a major impairment of quality of life.

Right convex apex is not a specific characteristic of dystrophic curves. It is more common in dystrophic curves than in nondystrophic curves, but it is commonly present in both types of curves.
Penciling of the ribs is one of the features specific for dystrophic curves in neurofibromatosis 1.
Scalloping of the vertebrae anteriorly and posteriorly is characteristic of dystrophic curves in neurofibromatosis 1. Widening of the neural foramen is specific for dystrophic curves in neurofibromatosis 1. Widening of the neural foramen is due to tumorous masses passing through the foramen.
Thinning of the transverse process is a characteristic of dystrophic curves in neurofibromatosis 1.

There is an increased risk of loss of fixation in familial dysautonomia curves due to decreased bone density and curve rigidity.
Scoliosis is common in patients with familial dysautonomia and affects up to one-half of patients with the disorder. The curves in familial dysautonomia are rigid, leading to limited correction.
The bone density in familial dysautonomia is decreased.
Spinal stenosis is not reported in patients with familial dysautonomia.

Symptomatic stenosis of the thoracic and lumbar spine is seen in almost half of all achondroplastic patients, although not all patients require surgery.
Atlantoaxial instability is rare in achondroplasia, although it is not uncommon in other dysplasias. Basilar invagination is not present in achondroplasia.
Kyphosis is often transient in achondroplasia and rarely persists beyond the second year. Kyphosis is rarely symptomatic. Spondylolisthesis is rare in achondroplasia.

Many diastrophic cervical kyphoses will correct spontaneously if the curve does not exceed 50°. In this patient, the lack of walking is most likely due to other skeletal factors.
There is no evidence that orthosis will change the natural history of the disorder.
There is no need for traction given the high chance of spontaneous resolution and the dangers of traction.
Posterior fusion is only indicated if the kyphosis is continually progressive, or if neurologic signs or symptoms develop. Anterior and posterior surgery is only indicated in cases with severe pre-existing neurologic deficit.

Patients with diastrophic dysplasia rarely have instability of the upper cervical spine.
Babies with diastrophic dysplasia often have rigid equinovarus feet that require surgery to become plantigrade and wear normal shoes.
A number of patients with diastrophic dysplasia develop progressive scoliosis that requires surgical treatment. Degenerative disease of the hips is common and often requires arthroplasty in early adulthood.
Degenerative disease of the knees is common and often requires arthroplasty in early adulthood.

Atlantoaxial instability, sometimes combined with stenosis of the atlas, is a frequent cause of myelopathy in spondyloepiphyseal dysplasia congenita.
Scoliosis does not account for developmental delay or myelopathy.
Foramen magnum stenosis is rare in spondyloepiphyseal dysplasia congenita.
Lumbar stenosis is rare with spondyloepiphyseal dysplasia congenita and would not account for myelopathy. Thoracolumbar kyphosis severe enough to cause myelopathy is rare in spondyloepiphyseal dysplasia congenita condition.

Scoliosis with cleidocranial dysplasia (C C D) is frequently associated with syringomyelia.
C ervical instability is rare in C C D. Spondylolisthesis is rare in C C D. Spinal stenosis is rare in C C D.
Spinal decompensation is rare in C C D.

Posterior cervical fusion has been proven effective in curves of 60°or less in Larsen syndrome, in preventing progression, and allowing correction with anterior growth.
This curve is much more likely to worsen than to spontaneously improve, so preventive surgery is indicated. There is no role for halo traction in this situation.
Bracing has not been proven effective in helping patients with Larsen syndrome.
Addition of anterior fusion is not needed for this degree of curve in a neurologically normal child.

Anterior and posterior fusion will correct the translation, instability, and ensure a solid fusion. In some cases, posterior fusion alone will suffice if pedicle fixation is good.
Exercises will not correct the subluxation, which is the cause of the pain. A thoracolumbar orthosis is not corrective or well tolerated.
There is no need for halo traction.
Anterior fusion alone is not enough to control this focal instability if the patient is well enough to tolerate a more involved procedure.

Aneurysmal bone cyst of the spine is most common in the lumbar spine, followed by the cervical spine. Aneurysmal bone cyst most commonly involves the anterior elements but later may expand into the posterior elements.

The most common age is the second decade; the mean age is 13 years old for patients with this disorder.

This patient has an aneurysmal bone cyst. Selective arterial embolization is a minimally invasive treatment that often succeeds in arresting the lesions. Many times it is the only treatment needed. Selective arterial embolization can also be used as part of a strategy to be followed by curettage and reconstruction to decrease operative bleeding.
This lesion will continue to expand and might cause neurologic compromise or mechanical instability. Radiation therapy poses risks of later malignant degeneration. There are other ways of treating this lesion. Radical en bloc resection may unnecessarily injure neurologic structures.
While curettage is often necessary, there is no reason to introduce the risk of radiation therapy.

Low back pain, followed closely by ipsilateral knee pain, is the most common late effect of hip arthrodesis in young patients. The tolerable pain usually occurs much later but may be treated by conversion to arthroplasty, if needed.
Ipsilateral hip pain should be minimal or absent if the fusion is successful.
Activity following arthrodesis is not significantly limited. Sports and heavy physical activities are feasible. The limp is usually minimal because the loss of hip motion is masked by lumbar motion.
Pain in the contralateral hip is rare and is often minimal after hip arthrodesis.

Neutral abduction is important in preventing back pain.
The flexion should be between 25° and 35°.
Any abduction beyond neutral poses increases risk of back pain. External rotation beyond approximately 5° is not needed.
Arthrodesis often produces some mandatory shortening; therefore, intentional shortening is not needed.

Bilateral proximal femoral resection is the recommended treatment.
Femoral head dislocations may become painful in cerebral palsy at a much earlier age than in nonspastic individuals. Botulinum toxin or adductor tenotomy will not solve the problem.
Replacing the deformed femoral heads into the acetabulum will not achieve the long-term goal of good hip range of motion.

The translation and shortening are not problems and the amount of angulation will easily remodel with this fracture. There is nothing to be gained from operative reduction.

Eight inch-pounds is the currently recommended torque to provide optimal biomechanical fixation while minimizing pin penetration. This is also recommended for adults. In young children, 4- to 6-inch-pounds are preferred.

Spinal cord injury occurs in approximately 0.1% of patients operated upon for idiopathic scoliosis. In some cases, sensory spinal cord monitoring may be unchanged, especially if the injury preserves the dorsal columns. The instrumentation should be removed as soon as possible in case spinal traction or derotation or implant protrusion is producing effects on the cord or its blood supply.
C orticosteroids should be administered at spinal cord injury doses, but this should not be the only measure. Obtaining a myelogram may delay the removal of instrumentation and should not be the first step. Heparinization has no proven effect.

Extensive posterior decompression poses a high risk of postoperative increase in kyphosis because of both the patientâs age and pre-existing kyphosis.
Observation would not be a good idea because the risk is already known to be high.
Neither a brace nor an uninstrumented fusion would prevent the deformity from developing. C orpectomy is not indicated because the kyphosis is not focal.
Posterior instrumented fusion at the time of decompression is indicated.

Brace treatment is effective for Scheuermann kyphosis. Unlike idiopathic scoliosis, permanent correction of the deformity is the goal.
The Milwaukee brace is often indicated.
Brace treatment is ineffective for curves over 74°. The brace should be worn until skeletal maturity.

Bone marrow transplantation is effective in preventing the deposition of mucopolysaccharides in solid organs. Transplantation should be done early to prevent organ damage. Because the lysosomal enzyme does not cross the cell membrane of osteocartilaginous cells, it does not affect the orthopedic aspects. The risk of graft-versus-host disease is high but may be treated in most cases. Survival rate is 61% at 2 years for Hurler disease, which is otherwise fatal before maturity.

Nonoperative treatment will allow the patient to retain maximum mobility of the hips.
Operative treatment carries substantial risk of avascular necrosis, stiffness, and redislocation. These risks are not worth taking in view of the patientâs limited muscle strength about the hips. In addition, the motor level alluded to (L2-L3) means that she will not have sensation of pain from the hips.

This scenario is common. The most likely explanation of the patientâs loss of motor power on either side below the knee is a result of a tethered spinal cord.
It is unlikely that all transferred tendons have pulled out and that he has lost function in all of the other L5 muscles that should be active.
Shunt malfunction is a common occurrence in patients with spina bifida, but shunt malfunction does not present with a focal deficit at a distal level.
Muscle fatigue is not a recognized phenomenon in spina bifida.

Low-energy fractures are the most likely cause of the patientâs bilateral swollen legs. The fractures may occur with everyday activities, and they do not cause pain because of the patientâs high neurologic level. If plain radiographs do not give the diagnosis, stress radiographs should be obtained to detect undisplaced physeal fractures.
Deep vein thrombosis is rare in this age group, especially bilaterally.
Spontaneous joint infection and spontaneous osteomyelitis are not any more likely in patients with spina bifida than in the general population.

At motor level L5, dorsiflexors overpower plantarflexors to cause a calcaneus position.
This condition occurs from muscle imbalance. Even with significant ambulation, it will persist. Brace properties do not cause fixed deformity.
At L3, neither dorsiflexors nor plantarflexors of the ankle work. At S1, both dorsiflexors and plantarflexors are well innervated.

The leverage provided by long instrumentation prevents loss of correction and junctional deformity.
Short instrumentation poses a risk of junctional kyphosis or loss of fixation.
Because of the severe angular deformity, fusion in situ without correction will be followed by increasing deformity. Resection of one to three of the vertebrae on the lower limb of the kyphosis is essential to allow safe correction without excessive tension on vessels and viscera.
The anterior approach to the gibbus is deep and impractical. This approach does not allow mechanically efficient instrumentation.

Latex sensitivity is common in patients with spina bifida because of frequent exposure through catherizations and procedures. Latex avoidance is becoming the standard in institutions that commonly treat patients with spina bifida, but community hospitals that rarely see such patients may not always be aware of this problem.
Dissection is not likely unless the patient has a connective tissue disorder. Septic shock is not likely to develop from a freely draining peripheral ulcer.
Tension pneumothorax is not any more likely in patients with spina bifida than in the general population.
Although it is important to be aware of shunt failure, it is not likely in this procedure which is done without anesthetic.

Aneurysmal bone cyst is the most common benign bone tumor of the vertebral body. Aneurysmal bone cysts sometimes extend into the posterior elements.
Osteoid osteoma, osteoblastoma, and osteochondroma are primarily found in the posterior elements of the vertebrae. Giant cell tumor is rare in the spine.

A Gibbs artifact is a linear focus in the cord on T2-weighted images that parallels the ventral aspect of the cord and mimics a syrinx. The Gibbs artifact is due to the linear interface between two tissues of differing signal intensity. It is not seen on axial images or T1-weighted images.
Motion artifact is a blurring of the image due to patient motion, respiration, or cerebral spinal fluid pulsation. Ependymoma and astrocytoma are seen on both the axial and the sagittal images.