ORTHOPEDIC MCQS OB 20 BASIC 6

 

599. A college athlete on a scholarship has a medical condition that you feel presents a life-threatening risk to him with participation in athletics. Because of the gravity of this decision and the potential effect it can have on the student/athlete's future, the college asks for your guidance. As the team physician for the college, what is your ethical obligation?

 

1. Ban the athlete from sports participation.
2. Allow the athlete to participate as it is his constitutional right to do so.
3. Advise the college to revoke the athlete's college scholarship.
4. Offer no opinion as it is a matter strictly between the college and the athlete.
5. Recuse yourself from all decision making and advise the athlete to get an opinion from a third-party physician who is not employed by the college or university.

 

Corrent answer: 1

There is legal precedent for banning a scholarship athlete from participation in college athletics if the physician feels that it presents a significant physical risk to the athlete. The courts have decided that the athlete has no constitutional right to participate in NCAA sports, and as a team physician you must advise your athlete and the school as to the best course of action. The athlete must be allowed to keep his or her college scholarship.

 

600. Figure 59 shows properties of a material being tested for use as an implant. What is represented by the portion of the stress-strain curve from point A to point B?

 

1. Elastic limit
2. Nonproportional behavior
3. Plastic behavior
4. Elastic behavior
5. Fracture point

 

Corrent answer: 4

 

The figure is a stress-strain diagram representing specific metal subjected to increasing tensile stress. The portion of the curve from A to B is a straight line demonstrating a proportional increase in strain for each increase in tensile stress. If the stress is removed at any point between A and C, the material will return to its original shape, returning back along the original curve without permanent deformation. This is termed elastic behavior. If the applied stress causes strain beyond point C, then permanent deformation occurs and returns along a different path to a different zero stress point. This is termed plastic behavior. The point C at which the material stops behaving in an elastic manner and begins behaving in a plastic manner is the elastic limit or yield point. Point D represents a point on the curve of plastic deformation. Point E is the fracture point when the stress on the material creates enough strain that the material fractures.

 

601. Which of the following diseases has documented transmission by allograft tissue transplantation in the last 20 years?

1. Tuberculosis
2. Hepatitis B
3. HIV
4. West Nile virus
5. Clostridium

 

Corrent answer: 5

 

The only reported cases of HIV transmission with tissue transplantation occurred more than 20 years ago. The only reported cases of tuberculosis and hepatitis B occurred more than 50 years ago. The donor-associated clostridium infection occurred in 2001. The facility was not AATB-accredited (American Association of Tissue Banks) and the local AATB facility refused the graft. It is necessary for the surgeon using the allograft tissue to be aware of the current status of tissue regulation, and procurement and processing procedures.

 

602. An otherwise healthy 25-year-old man underwent a right

anterior cruciate ligament reconstruction with a bone-patellar tendon- bone allograft. Routine preimplantation cultures of the allograft taken by the surgeon were positive for coagulase-negative Staphylococcus 5 days postoperatively. The patient has exhibited no evidence of clinical infection and his postoperative course has been uncomplicated during this time. What is the ideal management of this patient?

 

1. Observation
2. Oral antibiotics for 6 weeks
3. IV antibiotics for 6 weeks
4. Arthroscopic irrigation and debridement with graft retention
5. Arthroscopic irrigation and debridement with graft removal

 

Corrent answer: 1

 

The incidence of preimplantation positive cultures of musculoskeletal allografts used for anterior cruciate ligament reconstruction has varied between 4.8% and 13.3%.

Interestingly, in none of the studies evaluating this issue did any of the patients implanted with a "contaminated" graft develop a clinical infection. The results of the current literature suggest that the treatment of

low-virulence organisms is unnecessary if no evidence of clinical infection exists. Preimplantation cultures do not appear to correlate with clinical infection. Therefore, the routine culture of allograft tissue is not recommended.

 

603. Which of the following most accurately approximates the estimated risk of a musculoskeletal allograft containing the human immunodeficiency virus (HIV)

despite adequate screening?

 

1. 1 in 600

2. 1 in 6,000

3. 1 in 60,000

4. 1 in 1,600,000

5. 1 in 6,000,000

 

Corrent answer: 4

 

The calculated risk of a musculoskeletal allograft containing HIV despite adequate screening has been estimated to be approximately 1 in 1.6 million. This estimate is based on the risk of HIV in the population, projected population estimates, and current methods of donor screening.

 

604. What allograft has the highest antigenicity when used for ligament reconstruction about the knee?

 

1. Tibialis anterior used for anterior cruciate ligament (ACL) reconstruction
2. Tibialis anterior used for posterolateral reconstruction
3. Bone-patellar tendon-bone used for ACL reconstruction
4. Semitendinosus used for posterior cruciate ligament reconstruction
5. Semitendinosus used for medial collateral ligament reconstruction

 

Corrent answer: 3

 

Although theoretically the intra-articular environment is slightly more immune privileged, the role of immunogenicity is related more to bone than soft tissue. Therefore, the bone- patellar tendon-bone used for ACL reconstruction would have the highest risk of immunogenicity if storage techniques and harvest techniques were similar. This also is true for bone plugs associated with meniscal allografts.

 

605. What serum marker is most closely associated with colorectal carcinoma?

 

1. Carbohydrate antigen 125
2. Carcinoembryonic antigen
3. Carbohydrate antigen 19-9
4. Cancer Antigen 15-3
5. Alpha fetoprotein

 

Corrent answer: 2

 

Carcinoembryonic antigen (CEA) is most closely associated with colorectal carcinoma.

Lang reviews the science behind identification and utilization of cancer antigens for diagnosis, treatment response monitoring, and vaccine purposes.

 

Incorrect answers:

1.Carbohydrate antigen 125 (CA-125) is seen in ovarian cancer. 3.Carbohydrate antigen 19-9 (CA-19-9) is seen in pancreatic cancer. 4.Cancer antigen 15-3 (CA-15-3) is seen in breast cancer.

5.Alpha fetoprotein (AFP) can be seen in many cancers, but is most commonly seen in hepatocellular carcinomas.

 

606. The diagnosis of gout can be made either by the presence of tophaceous deposits in the skin or bursae of the extremities or by the presence of which of the following?

 

1. Elevated urine pH
2. Elevated serum uric acid
3. Calcium pyrophosphate crystals in the synovial fluid
4. Monosodium urate crystals in the synovial fluid
5. Elevated serum phosphate

 

Corrent answer: 4

 

Gout is an inflammatory arthritis caused by the presence of monosodium urate crystals in the joint. It is characterized acutely by a painful joint that remits after 1 to 2 weeks and recurs periodically. The diagnosis of gout can be made by confirming the presence of monosodium urate crystals in the joint fluid

aspirated from the inflamed joint. Patients with gout may also have tophaceous deposits within the skin or bursae of the extremities. Elevated urine pH, serum uric acid, and serum phosphate can all be associated with numerous conditions and are not specific to gout. Calcium pyrophosphate crystals are associated with chondrocalcinosis (pseudogout).

 

607. A 72-year-old woman is evaluated for sacrococcygeal pain sustained after a twisting injury. Radiographic and MRI evaluation confirms the presence of a nondisplaced fracture at the sacrococcygeal junction. Over a 3-week period, the pain has gotten significantly better. No additional lesions or injuries are noted.

Laboratory studies show a serum calcium level of 8.8 mg/dL (normal 8.6-10.3 mg/dL) and a 25-OH Vitamin D level of 14 ng/mL (normal

30-80 ng/mL). What is the most appropriate treatment for this patient?

 

1. Expectant observation
2. Calcium supplementation
3. High dose vitamin D supplementation
4. Bisphosphonate therapy
5. Surgical fixation of the sacrococcygeal fracture

Corrent answer: 3

 

Chronic Vitamin D deficiency leads to problems with bone health and has been shown to increase the risk of falls in the elderly. Appropriate supplementation of Vitamin D has been shown to decrease this risk. Conversion in the skin decreases with age and may be nearly nonexistent in darkly pigmented individuals. Vitamin D3 is the preferred form for supplementation, but D2 is the form most available by prescription in the US. Hypervitaminosis D is rare and very high doses can be tolerated without significant concern for toxicity. Because the patient has sustained one insufficiency fracture, she is at risk for insufficiency fractures in other skeletal locations, rendering expectant observation insufficient. Her serum calcium is normal, and with a low Vitamin

D level, calcium utilization in her system would be inadequate. Bisphosphonate therapy in addition to calcium and vitamin D supplementation may provide a good long-term solution, but should not be instituted until the bone mineral imbalance has been adequately corrected. Surgical fixation of this fracture is not indicated, particularly in lieu of improving symptoms.

 

608. Figures 70a and 70b show the radiograph and MRI scan of a 66- year-old man who has fatigue, weight loss, and muscle weakness. Examination reveals marked pain and discomfort in the left mid leg. Biopsy specimens are shown in Figures 70c and 70d. What is the most likely diagnosis?

 

1. Mastocytosis
2. Multiple myeloma
3. Hyperparathyroidism
4. Metastatic carcinoma
5. Multicentric giant cell tumor

 

Corrent answer: 3

 

The signs and symptoms of hyperparathyroidism are similar to those in patients with diffuse skeletal metastases. Serum markers are very helpful in making the diagnosis. In this patient, the radiograph shows multiple lesions in the tibia and proximal fibula that have a variable appearance. For example the mid-tibial lesion is radiolucent and slightly expansile whereas the more proximal tibial lesions are radiodense. The proximal fibula lesion is mixed (radiolucent/radiodense). These findings would be very uncommon in patients with myeloma, metastatic disease, or multicentric giant cell tumor. The histopathology shows a bland fibrous stroma with multiple multinucleated

giant cells. On higher power, the stromal cells are spindled and the giant cells are relatively small in contrast to giant cell tumor where the giant cells are larger and the stromal cells are more rounded with nuclei that closely resemble those in the giant cells.

There is blood extravasation (stromal

hemorrhage) and hemosiderin deposition. The constellation of findings is most consistent with brown tumors due to hyperparathyroidism (secondary to a parathyroid adenoma in this patient).

 

609. A 68-year-old woman has had progressive pain in the right thigh for the past several months. She has a history of hypertension, treated with hydrochlorothiazide and osteoporosis treated with alendronate

for 10 years. At this point, she is virtually wheelchair bound.

Radiographs are shown in Figures 78a and 78b. Additional studies show no signs of systemic disease. What is the most likely etiology of her condition?

 

1. Prolonged use of bisphosphonates
2. Use of calcium-wasting diuretics
3. Occult metastatic cancer
4. Vitamin D-resistant rickets
5. Disuse osteopenia

 

Corrent answer: 1

 

The patient has been on alendronate for 10 years and has evidence of a proximal diaphyseal fatigue fracture. These have been associated with long- term use of bisphosphonates. Staging studies have failed to show systemic disease, and while metastasis with an unidentifiable primary does occur, it would be unlikely to present with this radiographic appearance, now recognized to be classic for stress fractures associated with chronic bisphosphonate usage. Hydrochlorothiazide does not cause calcium wasting. Vitamin D-resistant rickets would be a long-standing event and would present much earlier in life, often with pronounced deformities. Whereas the patient's progression to intolerance of weight bearing likely has led to some degree of disuse osteopenia, the underlying problem is the long-term bisphosphonate exposure.

610. A surgeon recommends an interscalene regional block to a patient undergoing shoulder arthroscopy. When asked about potential complications, which of the following is most likely to occur?

 

1. Persistent motor neuropathy
2. Sensory neuropathy
3. Complex regional pain syndrome
4. Pneumothorax
5. Cardiac arrythmia and arrest

 

Corrent answer: 2

 

Sensory neuropathy is the most common complication seen with interscalene regional block.

1. FOR ALL MCQS CLICK THE LINK ORTHO MCQ BANK

Bishop et al. retrospectively reviewed 478 patients who had shoulder surgery under interscalene regional block. A total of 462 patients (97%) had a successful block. While all of the answers have been described, in this study no patient had a seizure, pneumothorax, cardiac event, or other major complication. Twelve (2.3%) of the 512 patients who had a block had minor complications, which included sensory neuropathy in eleven patients and a complex regional pain syndrome that resolved at three months in one patient. For ten of the eleven patients, the neuropathy had resolved by six months.

 

611. Cathepsin K is an enzyme produced by osteoclasts. What is the function of cathepsin K?

 

1. Reduction of disulfide bonds in the extracellular matrix
2. Bone resorption
3. Activation of RANK (Receptor activator of nuclear factor kappa-B)
4. Antagonize the action of RANK
5. Absorb water in the extracellular matrix

 

Corrent answer: 2

 

Cathepsin K is an enzyme produced and released by osteoclasts at the ruffled border that functions to resorb bone. Cathepsin K inhibitors are being clinically evaluated as potential anti-resorptive drugs for use in osteoporosis treatment. Other proteins associated with osteoclasts include tartrate-resistant acid phosphatase (TRAP) and calcitonin receptor.

Illustration A is a drawing that depicts the action of cathepsin k within osteoclasts.

 

612. What is the primary problem in rickets osteomalacia?

 

1. Defect in the zone of proliferation within the physis
2. Defect in type I collagen
3. Defect in the ext-1 gene
4. Low level of calcium
5. Production of dysplastic fibrous bone

 

Corrent answer: 4

 

Rickets is a disorder of bones in children that results from decreased calcium available in the blood resulting in poor mineralization of bone that can lead to fractures and deformity. The most common cause of rickets is from vitamin D deficiency but it can also be caused by poor nutrition or gastrointestinal

disease that results in poor calcium absorption such as celiac disease or severe diarrhea from other causes. Rickets is not primarily a physeal disorder. Osteogenesis imperfecta is caused by a defect in type I collagen. A defect in

the ext-1 gene is often seen in patients with multiple hereditary exostoses. Fibrous dysplasia also can result in bone deformity and fractures due to production of dysplastic fibrous bone but is not caused by calcium or vitamin D deficiency.

 

613. If an orthopaedic surgeon receives royalties from a company for his or her participation in the design and development of a product, and uses that same product for the care of his or her patients, what is the orthopaedic surgeon's obligation?

 

1. Obligated to disclose only the fact that he or she was involved in the design and development
2. Obligated to disclose only the company relationship if there is a state law requiring it
3. Obligated to disclose his or her full relationship with the company, including the fact that he or she receives royalties
4. No obligation to disclose this private matter to the patient
5. Avoid this situation because it should not exist since he or she cannot use such a product

 

Corrent answer: 3

 

The AAOS has a specific code of ethics and professionalism that addresses this issue: "When an orthopaedic surgeon receives anything of value, including royalties, from a manufacturer, the orthopaedic surgeon must disclose this fact to the patient." It is derived from a broader document developed by the American Medical Association, and is applicable to all physicians. At present, this is an ethical issue receiving greater federal scrutiny. This issue has had a greater effect on the public's perception of the integrity of the orthopaedic profession.

 

614. A minimally invasive plate osteosynthesis is seen in Figure 15. The resultant fracture healing can best be attributed to a fixation construct that was

 

1. stiff and stable.
2. flexible and stable.
3. facilitating direct osteonal healing.
4. inhibitory to endochondral ossification.
5. stimulatory to intramembranous ossification.

Corrent answer: 2

Locked plating constructs with long-working lengths provide flexible but stable constructs that promote (not inhibit) endochondral ossification. Because of the longer working length they are not stiff, and these fractures do not heal with intramembranous ossification which occurs in bones like the calvarium. Direct osteonal healing is usually seen with constructs

where absolute stability is achieved through interfragmentary compression, unlike in this case.

 

615. An orthopaedic surgeon makes an incision on a right knee and realizes that the patient was supposed to have a left total knee arthroplasty. The surgeon should do which of the following?

 

1. Leave the wound open and talk to the family immediately.
2. Close the wound, abort the surgery, and talk to the patient and family when the patient is awake.
3. Close the wound, complete the left knee arthroplasty, and talk to the family after the surgery is complete.
4. Complete the surgery and talk directly to the patient the following day on rounds.
5. Discuss the problem in the office the next week in a calm reassuring manner.

 

Corrent answer: 3

 

The AAOS recommendation is to complete the correct surgery, repair the incorrect surgery to as close to normal as possible, and then discuss it openly with the family after the surgery is complete. Prompt informing is necessary. Aborting the surgery then results in the patient requiring a second anesthesia and surgical time needlessly.

 

616. Spindled cells that are surrounded in mature osteoid that

connect to other similar cells via canaliculi are best described as which of the following?

 

1. Osteoblasts
2. Osteoclasts
3. Osteocytes
4. Histiocytes
5. Megakaryocytes

 

Corrent answer: 3

 

Osteocyte cell processes travel through canaliculi to interconnect with other osteocytes and cells on the bone surfaces. Osteoblasts are cells that produce bone matrix and are seen rimming immature bone. Osteoclasts are large multinucleated cells that resorb bone and are found in Howship's lacunae. Megakaryocytes and histiocytes are found in marrow but not mature bone cortex.

617. A 48-year-old woman has an open subtrochanteric femur fracture. No other injuries are reported. After thorough evaluation, it is determined that she will need emergent surgical fixation. The patient and family indicate that they are practicing Jehovah's witnesses and desire adherence to the religious standards with respect to blood product usage. The patient signs a valid advanced directive confirming these wishes. Which of the following would be considered acceptable treatment?

1. Whole blood
2. Platelets
3. Plasma
4. Starch product (ie, Hetastarch, Hespan)
5. Donor-directed blood from a family member who is a practicing Jehovah's witness

 

Corrent answer: 4

 

Jehovah's witnesses beliefs regarding blood products stems from direct interpretation of passages from the bible. The use of crystalloid, starch products such as Hetastarch and colloids are accepted. Typically Jehovah's witnesses will accept most medical treatment but refrain from the use of blood products including whole blood, packed red cells, platelets, white cells, or plasma. Any autologous transfusion, whether from the patient themself or donor directed, is forbidden. The use of cell-saver type processes is a matter of individual choice by the patient. The use of hemoglobin-based oxygen carriers are now accepted by many patients but it is important to respect the wishes of each individual patient. It is very important to discuss preoperatively with the patient and family their wishes and thoughts on what is acceptable to use. Many facilities have adopted

bloodless-surgery protocols and committees that definitively outline the measures that can be used and take into consideration the many ethical issues involved in taking care of these patients.

 

618. In a diagnostic test, the proportion of individuals who are truly free of a designated disorder identified by the test is known as

 

1. specificity.
2. sensitivity.
3. accuracy.
4. positive predictive value.
5. negative predictive value.

Corrent answer: 1

Specificity refers to the proportion of individuals who are truly free of the designated disorder who are so identified by the test. Sensitivity refers to the proportion of individuals who truly have the disorder who are so identified by the test. Positive predictive value refers to the proportion of individuals with a positive test who have the disorder. Negative predictive value refers to the proportion of individuals with a negative test who are free of the disorder.

Accuracy is the overall ability to identify patients with the disorder (true positives) and without the disorder (true negatives) in the study population.

619. An orthopaedic surgeon in his first year of practice is negotiating with a private for-profit hospital to be their employed trauma specialist. The state of employment is known to have a high rate of malpractice claims because of a favorable plaintiff legal environment. During the course of negotiations, malpractice insurance is being discussed. The surgeon should ask the hospital to provide which type of malpractice insurance policy?

 

1. Claims made with "nose" coverage
2. Claims made without tail coverage
3. No policy because of employed status and sovereign immunity
4. Occurrence coverage
5. Occurrence coverage with "nose" coverage

 

Corrent answer: 4

 

An occurrence policy provides coverage for all claims made during employment irrespective of when it is filed (during or postemployment) and therefore is the best option. Claims made policy only covers suits for the time employed. A prepurchased "tail" is needed to provide coverage for cases that occurred during employment but filed postemployment. Nose coverage is applicable if the surgeon was previously employed and did not have tail coverage from previous employment, but this surgeon just emerged from training where it is not applicable. Claims made without tail coverage is unwise because the surgeon would be unprotected or have to purchase his own policy postemployment.

Only in certain situations does sovereign immunity exist, and generally not in a for-profit system. Occurrence coverage with nose coverage

is incorrect because it does not apply to this surgeon with no previous employment or claims policy lacking tail coverage.

 

620. Results of a study demonstrating no difference between treatments when a difference truly exists is an example of which of the following?

 

1. Statistical insignificance
2. Type I error
3. Type II error
4. Fragile p-values
5. Negative predictive value

 

Corrent answer: 3

 

A type II error (also known as a beta error) occurs when results demonstrate that two groups are similar when, in reality, they are different (with regard to the statistic being measured). Type I errors show that a difference exists when, in reality, no difference exists. A statistically insignificant result may lead an investigator to conclude that no difference exists between two groups; this may be correct (and therefore not a type II error). The concept of

`fragile` p-values is that small sample sizes may result in wide variability of p- values with only one change in a data point for a given group. This singular change could be a chance occurrence, but it still can affect the statistical significance of the outcomes analysis.

Fragility of p-values is limited by increasing sample sizes. Negative predictive value is the

proportion of patients with negative test results who are correctly diagnosed.

 

621. A patient with a transverse femur fracture undergoes statically locked antegrade intramedullary nailing. Postoperatively, the patient appears to have a rotational deformity of greater than 25 degrees. The surgeon informs the patient, who chooses to undergo corrective treatment with removal of distal interlocking screws, rotational correction, and relocking of the screws. The patient goes on to heal

but has persistent hip pain and a limp that does not improve completely after extensive rehabilitation. There is complete healing, no evidence of infection, no hardware issues, no ectopic bone, and rotational studies indicate less than 2 degrees of malrotation. Functional capacity testing reveals the affected abductor and quadriceps function to be about 85% of the uninjured side and the patient returns to work and most of his recreational activities except rock climbing. Two days before the statute of limitations, the patient

files a malpractice suit alleging negligence of surgery, loss of function, consortium, and pain and suffering due to the surgeon's efforts. What action should the surgeon and the defense team take?

 

1. Settle the case because the surgeon made an error that resulted in unnecessary surgery, and thus the case is indefensible.
2. Settle the case because they are likely to lose the case, and it would be cheaper to settle than to defend.
3. Defend the case alleging that there was no error, and no damages, and that the patient is malingering.
4. Defend the case because despite there being an error, the error was corrected and there were little or no damages compared with expected outcomes.
5. Contact the patient directly to discuss why he is suing and attempt an amicable resolution.

 

Corrent answer: 4

 

To establish negligence, certain criteria must be met. 1) A duty was owed by the surgeon (in this case, yes, a relationship was established). 2) The duty was breached, where the provider failed to meet the standard of care (there

was a technical error, but it was corrected). 3) The breach caused an injury. In this case, the patient had an outcome that was very acceptable, as

documented with outcome studies, for femur fractures. Also, the rotational error and locking distally would have had little impact on the hip, whereas antegrade nailing itself is expected to result in some objective impairment of the hip in some patients. 4) Damages were incurred as a result. In this case, the patient returned to work and could not rock climb which could be reasonably expected with a femur fracture in some patients, and cannot be causally linked to the corrective surgery. For all practical purposes, the patient had a very acceptable outcome. Thus, settling the case for an error would be rather permissive and the important issue is that the surgeon recognized the problem, addressed it, and fulfilled his or her postoperative responsibility. The case is very defendable, and thus it is unlikely to be lost. Defending the case and alleging no error is incorrect because there was an error. The surgeon should never function outside of his or her legal counsel once a suit is filed.

622. You design a research study in which you ask patients who have a nonunion of the tibia to fill out a questionnaire in which they report on a variety of medical conditions and social/behavioral practices. You compare these findings to a similar group who did not develop a nonunion in order to identify medical and/or social conditions that might be risk factors for the development of tibial nonunions. This would be an example of what type of study?

 

1. Case series
2. Meta-analysis
3. Case control study
4. Retrospective cohort study
5. Prospective cohort study

Corrent answer: 3

 

A case control series starts with the occurrence of a specific disease or observation, and then compares data on those individuals to a similar group without the disease (control group) in order to identify potential risk factors for the development of the disorder. A case series is an observational study in which an investigator follows a series of patients who received a specific treatment, recording the results and outcomes of that treatment. A meta- analysis is the combination of several separate studies that look at similar hypotheses in an effort to create a larger patient population for analysis. A cohort study looks for the incidence of a specific outcome in two groups (cohorts) of patients who are similar with the exception of a particular

research variable (risk factor).

 

623. Which gene or protein is the most specific marker of mature osteoblasts but is not expressed by immature, proliferating osteoblasts?

 

1. Osteocalcin
2. TGF-B
3. COLIIA1
4. cFOS
5. IL-1

 

Corrent answer: 1

 

Osteocalcin is the most specific marker of the osteoblast phenotype and is expressed only in mature osteoblasts. TGF-B is a growth factor involved in the differentiation of multiple cell lines. For bone, TGF-B plays a role in stem cell differentiation into mesenchymal stem cells along osteoblast pathways. COLIIA1 is the gene for Type II Collagen and is involved in chondrocyte differentiation. cFOS is involved in osteoclast differentiation. In regards to

bone metabolism, IL-1 stimualtes osteoclastic bone resorption.

624. A workers' compensation carrier for a local manufacturing company requests a second opinion on a 59-year-old man who sustained a crush injury to his foot and leg at work 6 months ago. His leg and foot were pinned between a forklift and a wall when an employee he was supervising lost control of the forklift. The employer

suspects that the injured worker is malingering because the treating physician released him to work, but he has not returned to work. Which of the following elements of your history will best help you determine that the injured worker does not want to return to work out of fear of a confrontation with the employee he was supervising?

 

1. Formality
2. Empathy
3. Yes-no questions
4. Taking copious notes
5. Sitting leaning back in a chair

 

Corrent answer: 2

 

Empathy during the interview demonstrates compassion and earns the patient's trust; which, in turn, enables the patient to discuss any agenda or concerns he or she may otherwise feel uncomfortable revealing. It is also important to engage the patient to establish a trusting relationship and thus understand all the factors impacting the patient. A formal attitude toward the patient makes it difficult to engage the patient to be "drawn in." An engaged patient is more comfortable, reliable, and thorough when providing a history. Closed-end, yes-no questions do not allow the patient to detail all of the subtle nuances of their condition and its effect on their life. Taking copious notes likewise prevents engagement of the patient and the distraction of taking

notes may cause the physician to miss an important detail. It is better to lean forward in a chair when interviewing a patient because this suggests the physician is genuinely interested, whereas leaning back in a chair suggests the physician is simply waiting for the patient to finish talking. Avoid interrupting the patient when talking.

 

625. When a Workers' Compensation patient recovers after an injury to a point that further restoration of function is no longer anticipated, he or she is said to have reached which of the following?

 

1. Functional capacity
2. Maximum medical improvement
3. Permanent disability
4. Impairment rating
5. Predesignation

 

Corrent answer: 2

This is the definition of maximum medical improvement (MMI). The patient has essentially reached the plateau of his improvement.

Functional capacity evaluations (FCE) are based upon a theoretical model of comparing job demands to worker capabilities. The results of FCEs are often used to determine musculoskeletal capacity to return to work.

 

Strong et al. reported on the use of FCE in the Workers' Compensation system, and note how these FCE results are required by employers to determine the level of return to work of their employees. They also mention that the reports are frequently perceived with a negative tone. The employees reported a wider range of restrictions in their varied life roles than did the FCE reports, which deal more narrowly with work roles.

 

Pransky et al. reported that although FCE's are relied upon for determination of ability to perform physical work, several scientific, legal, and practical concerns persist. They note that test criteria often do not accurately reflect real-life job requirements or performance, and subjective evaluation remains common. They conclude that more research into predictive linking of FCE outcomes with occupational outcomes is necessary to determine their role in the Workers' Compensation system.

 

Incorrect Answers:

1: A functional capacity evaluation (FCE) is set of tests, practices and observations that are combined to determine the ability of the evaluated to function in a variety of circumstances (most often employment) in an objective manner.

3: Permanent disability is any lasting disability that results in a reduced earning capacity after maximum medical improvement is reached; this implies that MMI must be reached before this is determined.

4: Impairment rating is an objective data point obtained by a physician reviewing the patient's overall condition during a functional capacity evaluation.

5: This is the process a patient uses to tell their employer they want a personal physician to treat them for a work injury.

 

626. A physician receives a summons that he is being sued. The first step should be to

 

1. call the patient and apologize.
2. notify the medical liability carrier.
3. contact an attorney with whom the physician is familiar with and have the attorney review the records.
4. be sure to discard any handwritten phone messages because they are not discoverable.
5. find a colleague with a similar subspecialty and have the colleague review the record before doing anything.

 

Corrent answer: 2

 

The most appropriate first step is to notify the medical liability carrier. The medical liability carrier will assign an attorney who is likely to be more appropriate. A review by a colleague may be requested by the defense attorney but that should be at their discretion. Patient apology is appropriate early on when and if you discover an error.

Records should be reviewed, but never altered.

 

627. Currently, what is the most common clinical study type in the orthopaedic literature?

 

1. Level 1 (prospective, randomized trial)
2. Level 2 (cohort trial)
3. Level 3 (retrospective case control)
4. Level 4 (retrospective case series)
5. Level 5 (expert opinion)

Corrent answer: 4

Although a recent push for prospective, randomized trials has been advocated by multiple orthopaedic journals, many studies published continue to be of Level 4 evidence (retrospective case series). Case series represented 64% of all studies reviewed by Freedman and associates in 2001 from the British and American volumes of Journal of Bone and Joint Surgery and from Clinical Orthopaedics and Related Research.

Obremskey and associates published that

58.1% of all studies from nine orthopaedic journals were Level 4 evidence. Further investigation of more current trends is likely warranted with the

current emphasis on publishing higher level-of-evidence studies in orthopaedic journals.

 

628. Figure 147 is an MRI scan of a 72-year-old woman admitted to the hospital 7 days ago with persistent and worsening back pain. A

repeat vertebral augmentation was performed at L2 three days ago. Today she became diaphoretic, reported severe dyspnea, and collapsed during physical therapy. Examination reveals a pulse of

128/min, blood pressure of 98/55 mm Hg, and temperature of 100 degrees F (37.7 degrees C). Jugular venous distention is noted. What

is the most likely complication?

 

1. Spinal shock
2. Neurogenic shock
3. Hemorrhagic shock
4. Pulmonary embolism
5. Autonomic dysreflexia

 

Corrent answer: 4

 

The patient has the classic symptoms of a pulmonary embolism. Symptoms of pulmonary embolism of polymethylmethacrylate (PMMA) following vertebral augmentation may occur with a delay. A symptomatic pulmonary embolism following vertebroplasty can occur either by migration of acrylic or the migration of fat and bone marrow cells. The MRI scan reveals a new superior endplate fracture involving L2. With this now being the third consecutive vertebral compression fracture in 2 months, one must be suspicious that these represent pathologic fractures, rather than osteoporosis. Risk factors for venous thromboembolic disease include increasing age, prolonged immobility, surgery, trauma, malignancy, pregnancy, estrogenic medications (eg, oral contraceptive pills, hormone therapy, tamoxifen [Nolvadex]), congestive heart

failure, hyperhomocystinemia, diseases that alter blood viscosity (eg, polycythemia, sickle cell disease, multiple myeloma), and inherited thrombophilias. In addition to the risk associated with embolization of PMMA, the patient has been immobile for 7 days and was ultimately diagnosed with multiple myeloma.

 

629. Which key factor that induces osteoclastogenesis is secreted by osteoblasts in response to inflammatory stimuli?

 

1. Osteoprotegerin (OPG)
2. Tumor necrosis factor (TNF)
3. Insulin growth factor-1 (IGF)
4. Bone morphogenetic protein (BMP)
5. Receptor activator of nuclear factor kappa-B ligand (RANKL) Corrent answer: 5

Osteoclasts are derived from cells of the monocyte/macrophage lineage. They are multinucleated and develop by fusion of mononuclear precursors, a process that requires receptor activator for nuclear factor kappa-B ligand (RANKL) and macrophage-colony stimulating factor (M-CSF). RANKL is secreted by osteoblasts in response to inflammatory signals and is a key component of inflammation-mediated osteolysis. OPG binds to and sequesters RANKL, thus inhibiting osteoclast differentiation and activity.

BMP and IGF-1 are potent regulators of osteoblast differentiation and activation. TNF is a cytokine secreted by macrophages and degranulating platelets infiltrated in the fracture site and impacts a variety of cells, not osteoclasts.

 

630. A prospective outcome study is performed at a single institution to analyze the potential differences in treating intertrochanteric hip fractures with a plate/screw device versus an intramedullary device. No specific randomization is performed because an equal number of surgeons have preferences for the use of one of these devices and they are allowed to continue their preferred method. Hip- specific and general health-related outcome measures are used, an excellent follow-up rate of 85% of the patients at 2 years is accomplished, and there appears to be results that favor the intramedullary device but the confidence intervals are wide. This study would be considered to carry what level of evidence?

1. I
2. II
3. III
4. IV
5. V

 

Corrent answer: 2

 

This is a prospective comparative study but is not randomized or blinded and

is therefore a Level II therapeutic study. To qualify as Level I, it would need to be a high- quality randomized trial with narrow confidence intervals regardless of a significant difference or no difference in outcomes. Level III would be

case-control studies or retrospective comparisons. Level IV is case series and Level V is expert opinion.

 

631. The fracture seen in Figures A and B is most likely to occur in which of the following growth plate zones?

 

1. Resting zone
2. Proliferative zone
3. Zone of maturation
4. Zone of degeneration
5. Zone of provisional calcification

Corrent answer: 5

 

Physeal fractures typically occur through the zone of provisional calcification. Answers 3-5 are all part of the hypertrophic zone which is labeled "D" on the histologic illustration A. Illustration B shows the relationship of the physeal zones to the epiphysis and metaphysis of a growing bone. However, the stress concentration is greatest in the sub-layer where there is a transition from the soft cartilagenous physis to the harder calcific metaphysis.

As discussed in the review by Ballock and O'Keefe, the growth plate is a remarkable portion of the skeleton that requires precise coordination between multiple endocrine, paracrine, and autocrine signaling systems. While fractures can occur in any portion of the growth plate, the zone of provisional calcification is the most common.

 

632. Since the adoption by the American Academy of Orthopaedic Surgeons in 1997 of the presurgical protocol in which the surgeon signs the surgical site and the mandate for this protocol by the Joint Commission on the Accreditation of Healthcare Organizations (JCAHO)

in 2003, the total number of wrong-site surgeries reported per year in the United States has

 

1. increased.
2. decreased.
3. decreased for orthopaedic surgery but stayed the same for other surgeries.
4. remained the same.
5. only improved for hospital-based surgery.

Corrent answer: 1

Despite the initiatives by the American Academy of Orthopaedic Surgeons and the

JCAHO, the number of reported cases of wrong-site surgery has continued to increase yearly since 1997. Because reporting of these events is not mandated by JCAHO, it is possible that the continued increase is due to a greater awareness of the problem and thereby a greater level of reporting. The U.S. estimates are 12.7 wrong-site surgeries per million cases performed. Orthopaedic surgery and podiatry are the most common specialties associated with wrong-site surgery (41%) followed by general surgery (21%), neurosurgery (14%), and urologic surgery (11%).

 

633. The use of evidence-based studies among professions associated with health care, including purchasing and management, is known as

 

1. decision analysis.
2. cost-utility analysis.
3. cost-benefit analysis.
4. cost-effectiveness analysis.
5. evidence-based health care.

Corrent answer: 5

Evidence-based health care extends the application of the principles of evidence-based medicine to all professions associated with health care. This concept is becoming more important because data will be used by the different parties for their decision making (policy makers, health insurances, hospitals, doctors, and the public). Cost-benefit analysis refers to the conversion of effects into the same monetary terms as the costs and compares them. Cost- effectiveness analysis refers to the conversion of effects into health terms and describes the costs for some additional health gain (eg, cost per additional event prevented). Cost-utility analysis refers to the conversion of effects into personal preferences (or utilities) and describes how much it costs for some additional quality gain (eg, cost per additional quality-adjusted life-year).

Decision analysis refers to the application of explicit, quantitative methods to analyze decisions under conditions of uncertainty.

 

634. All of the following medications have been associated with an increased risk of osteoporosis EXCEPT:

 

1. Selective serotonin reuptake inhibitors (SSRI)
2. Glucocorticoids
3. Non-steroidal anti-inflammatories (NSAIDs)
4. Phenytoin
5. Protease inhibitors

 

Corrent answer: 3

 

Numerous drugs are associated with an increased risk of osteoporosis in

adults, including oral corticosteroids, androgen-deprivation therapy, aromatase inhibitors, protease inhibitors, selective serotonin reuptake inhibitors,

prolactin-raising antiepileptic agents and many cytotoxic agents.

Additionally, a number of disease states are associated with osteoporosis, including endocrinopathies such as hyperparathyroidism, thyrotoxicosis and type I diabetes, hypogonadism, chronic glucocorticoid therapy, malnutrition, malabsorption states, chronic immobilization, rheumatoid arthritis, alcoholism, vitamin D deficiency, and multiple myeloma.

 

NSAIDs have not been shown to increase risk of osteoporosis.

 

635. A 65-year-old woman with rheumatoid arthritis is unable to actively extend her index, middle, ring, and little fingers secondary to tendon rupture. In performing a flexor digitorum sublimis (FDS) of the middle/ring finger to extensor digitorum communis (EDC) transfer to restore active metacarpophalangeal (MCP) joint extension, the FDS should be passed

 

1. ulnarly, around the ulna in a dorsal direction.
2. radially, around the radius in a dorsal direction.
3. through the interosseous membrane.
4. through the intermetacarpal spaces between the index, middle, ring, and little fingers.
5. through the lumbrical canals of the index, middle, ring, and little fingers. Corrent answer: 2

Although the early use of FDS as a transfer to restore finger extension in patients with radial nerve palsy was performed by passing the tendon through the interosseous membrane, Nalebuff and Patel later modified this procedure for the rheumatoid arthritis patient by passing the FDS radially, around the radius in a dorsal direction. They felt that this provided a number of advantages, including: 1. technical ease, 2. avoidance of synovial disease on the dorsum of the wrist, and 3. correction of ulnar deviation of the fingers through the line of pull from the radial side of the forearm.

 

636. Based on the clinical photograph, radiographs, and biopsy specimen shown in Figures 68a through 68d, what is the most likely diagnosis?

 

1. Calcium pyrophosphate deposition disease
2. Bacterial infection
3. Fungal infection
4. Gout
5. Giant cell tumor

 

Corrent answer: 4

 

The patient has gout. Unfortunately, gout may mimic several conditions affecting the small joints of the hand, including infection. The histologic specimen shows negatively birefringent intracellular rods consistent with gout. The histology rules out giant cell tumor and calcium pyrophosphate deposition disease.

 

637. An otherwise healthy 30-year-old man undergoes right shoulder arthroscopic Bankart repair under regional anesthesia using an interscalene brachial plexus block. In the recovery room, he reports mild difficulty breathing and his chest radiograph shows a high riding diaphragm on the right side. His peripheral oxygenation is 97% on 2 liters of oxygen by nasal cannula. What is the most appropriate management?

 

1. Continued observation and monitoring
2. Obtain arterial blood gas measurements
3. Obtain emergent spiral CT scan to assess for pulmonary embolism
4. Insertion of a chest tube
5. Airway control and, if necessary, endotracheal intubation

Corrent answer: 1

 

Because the phrenic nerve lies in close proximity to the site of anesthetic injection, temporary hemidiaphragmatic paresis is a very common side effect of interscalene brachial plexus block. Pulmonary function and chest wall mechanics may be slightly compromised, but can easily be compensated in a healthy patient. Therefore, with

sufficient oxygenation, aggressive assessments or treatments such as arterial blood gas measurements,

emergent spiral CT scans, chest tube insertions, or endotracheal intubation are not warranted. For this stable patient, continued monitoring with gradual withdrawal of oxygen is the most appropriate treatment.

 

638. A 67-year-old woman with rheumatoid arthritis has had a 3-year history of gradually progressive right elbow pain and limited function despite intra-articular injections and medical management. She previously underwent a rheumatoid hand reconstruction, and has no pain or dysfunction of the ipsilateral shoulder.

Radiographs are shown in Figures 93a and 93b. What is the most appropriate treatment?

1. Soft-tissue interposition arthroplasty with radial head resection
2. Arthroscopic synovectomy with radial head resection
3. Elbow arthrodesis
4. Total elbow arthroplasty
5. Resection arthroplasty

 

Corrent answer: 4

 

Total elbow arthroplasty is the treatment of choice. The patient has end-stage rheumatoid involvement of the ulnohumeral and radiocapitellar joints. Given the advanced nature of the disease and evidence of bony erosion, arthroscopic

synovectomy and interposition arthroplasty are unlikely to provide lasting benefit or functional improvement. Elbow arthrodesis and resection arthroplasty are considered salvage techniques and are generally not considered as a primary treatment method.

 

639. A 66-year-old woman with known poorly controlled rheumatoid arthritis reports that for the past 4 weeks she has been unable to extend the metacarpophalangeal (MCP) joints of her right hand index, middle, ring and little fingers. She cannot hyperextend the thumb interphalangeal joint. Active wrist extension is possible, but shows radial deviation. Examination reveals mild synovitis at the wrist and MCP joints of the affected hand. There is no ulnar deviation at the MCP joints with normal alignment. When the MCP joints are passively extended, the patient is unable to maintain them in this position.

There is no piano key sign at the distal ulna. Passive wrist motion shows a normal tenodesis effect. Which of the following would most likely confirm your diagnosis?

 

1. Radiographs of the hand
2. Radiographs of the cervical spine
3. Electrodiagnostic studies of the affected upper extremity
4. Surgical exploration of the extensor tendon ruptures
5. MRI of the elbow

 

Corrent answer: 3

 

There are many causes of inability to extend the MCP joints in a patient with rheumatoid arthritis. The most common cause is rupture of the extensor tendons. An intact tenodesis test suggests that the extensor tendons are intact, thus surgical exploration is not indicated and would not confirm the diagnosis. The patient has normal alignment of the fingers without ulnar deviation, suggesting that there are no MCP dislocations to account for the inability to extend the MCP joints; therefore, radiographs would not confirm the diagnosis. The most likely cause of inability to extend the fingers in this patient is posterior interosseous nerve (PIN) palsy. Electrodiagnostic studies would confirm the presence of PIN palsy. An MRI of the elbow may show synovitis at the radiocapitellar joint, which can cause the PIN palsy. This finding however, is nonspecific and many patients without PIN palsy would also demonstrate synovitis at the radiocapitellar joint.

Therefore, although an MRI would be helpful in localizing a potential cause of PIN compression, it would not in itself confirm the diagnosis.

 

640. What is the predominant type of collagen found in the nucleus pulposus of the intervertebral disk?

 

1. Type I
2. Type II
3. Type V
4. Type VI
5. Type XII Corrent answer: 2

Types I and II collagen are the predominant types of collagen found in the intervertebral disk. Type I collagen is present in the highest concentration in the annulus fibrosus and type II collagen in the nucleus pulposus. Type V collagen is present in small concentration in the annulus fibrosus. Type VI collagen is a non-fibrillar, short-helix collagen found in both the annulus and nucleus. Type XII is present in the annulus fibrosus only.

 

641. What complication is associated with the use of epidural morphine and steroid paste after laminectomy?

 

1. Surgical site infection
2. Arachnoiditis
3. Urinary retention
4. Disk space infections
5. Nerve irritation

 

Corrent answer: 1

 

Kramer and associates conducted a retrospective review during an "epidemic" period to identify the risk factors associated with a sudden increase in the rate of surgical site infections. They found in a multivariate analysis that the use of morphine nerve paste resulted in a 7.6-fold increase in postoperative surgical wound debridement, and an 11% rate of surgical site complications. There is no evidence in the literature verifying the incidence of postoperative urinary retention and arachnoiditis.

 

642. Which of the following materials has the highest modulus of elasticity?

 

1. Cortical bone
2. Cobalt-chrome
3. Ceramic
4. Titanium
5. Stainless steel

Corrent answer: 3

 

Young's modulus of elasticity is a measure of the stiffness of a material and its ability to resist deformation. This is the slope of the stress/strain curve in the elastic range. The highest modulus is ceramic, followed by: cobalt-chrome alloy, stainless steel, titanium, and then cortical bone.

 

643. What medication has been shown to decrease osteolysis after total joint replacement surgery?

 

1. Bisphosphonates
2. NSAIDs
3. TNF-alpha inhibitors
4. Calcium and vitamin D supplementation
5. BMP-7

 

Corrent answer: 1

 

Bisphosphonates have been shown to decrease osteolysis after total joint replacement surgery.

 

Aseptic loosening and osteolysis are the primary causes of implant failure in total joint arthroplasty. Early findings indicate that bisphosphonates upregulate bone morphogenetic protein-2 production and stimulate new bone formation, leading to decreased osteolysis in total joint replacement surgery. While

further investigation is required, bisphosphonates may play a future role in improving the long-term duration of joint arthroplasties.

 

Shanabhag et al. reviewed the use of bisphosphonates and reported that they had the potential to enhance bone ingrowth into implant porosities, prevent bone resorption under adverse conditions, and dramatically extend the long- term durability of joint arthroplasties. They recommended further investigation into the subclasses to determine which ones are most beneficial.

Arabmotlagh el al. performed a prospective study on use of alendronate after total hip arthroplasty. They reported that the alendronate-treated patients had significantly less periprosthetic bone loss on DXA scans after 6 years.

 

Illustration A shows evidence of osteolysis (arrows) around a total hip arthroplasty.

 

Incorrect Answers:

2-5: These medication classes do not decrease osteolysis after total joint arthroplasty.

 

644. A 60-year-old woman has progressive neck pain, upper extremity pain, and paresthesias. A lateral cervical spine radiograph and an MRI scan are shown in Figures 52a and 52b. What is the most likely underlying diagnosis?

 

1. Osteomyelitis
2. Ankylosing spondylitis
3. Age-related degenerative changes
4. Rheumatoid arthritis
5. Previous cervical decompression Corrent answer: 4

The radiograph and sagittal T2-weighted MRI scan show multilevel degenerative changes and subaxial subluxations with anterolisthesis at C3-C4 and C4-C5 and retrolisthesis at C5-C6. In addition, there is evidence of midcervical kyphosis. Such findings are often seen in patients with rheumatoid arthritis. Patients with osteomyelitis typically show increased signal intensity in the disks and vertebral bodies. Patients with ankylosing spondylitis typically show ankylosis of the disks and vertebral bodies. Age-related degenerative changes typically manifest as degenerative disk disease with occasional single- level spondylolisthesis, but not typically multilevel spondylolisthesis, as seen in this patient. The spinous processes are intact; these changes do not appear to be postoperative.

 

645. Which of the following actions increases radiation exposure to patients and personnel when using fluoroscopy?

1. The use of lead glasses, thyroid shield, and a lead apron with a equivalent lead thickness of 0.25 mm
2. Orienting the cathode ray tube beneath the patient with the image intensifier receptor as close to the patient as possible
3. Limiting the beam on time to only what is clinically important
4. The use of continuous fluoroscopy to ensure proper placement of implants
5. Orienting the beam in the opposite direction of the working team and keeping the team outside a 6-foot radius from the fluoroscopy machine

 

Corrent answer: 4

 

Continuous fluoroscopy and cineradiography exposes the patient and personnel to markedly increased levels of direct and scatter radiation exposure. Continuous fluoroscopy should be limited to only what is absolutely needed for safe completion of the procedure. By orienting the cathode ray

tube beneath the patient and placing the image intensifier as close as clinically possible to the patient, scatter radiation exposure to the personnel is minimized.

 

646. Smoking has been associated with lower fusion rates in both cervical and lumbar fusion. Which of the following statements best describes an explanation for these findings?

 

1. Nicotine impairs osteoblast activity, thus interfering with bone remodeling.
2. The effects of smoking on bone healing are multifactorial and not yet fully understood.
3. The vasoconstrictive and platelet-activating properties of nicotine inhibit fracture healing.
4. Nicotine inhibits the function of fibroblasts, red blood cells, and macrophages.
5. Hydrogen cyanide inhibits oxidative metabolism at the cellular level. Corrent answer: 2

Tobacco smoking is now the leading avoidable cause of morbidity and mortality in the United States. The musculoskeletal effects of smoking have been implicated in osteoporosis, low back pain, degenerative disk disease, poor wound healing, and delayed fusion and fracture healing. A number of studies have demonstrated the relationship between smoking and development of pseudarthrosis. Numerous studies have been performed to

offer an explanation of the mechanism mediating this effect. Whereas all of the above have been postulated as explanations, more recent studies have

demonstrated that nicotine delivered via a transdermal patch significantly enhanced posterior spinal fusion in rabbits. Thus it appears that the effects of smoking on fracture healing are multifactorial and not yet fully understood.

 

647. In which of the following scenarios should a physician be relieved of their duties?

 

1. After 24 hours of continuous work
2. A significant error in care is noted
3. The physician appears fatigued
4. Physician is recovering from an ankle fracture
5. Chemical impairment is suspected

 

Corrent answer: 5

 

Impairment of a healthcare professional is the inability or impending inability to practice according to accepted standards as a result of substance use, abuse, or dependency (addiction). A surgeon (resident, fellow or attending) who discovers chemical impairment, dependence, or incompetence in a colleague or supervisor has the responsibility to ensure that the problem is identified and treated. Mechanisms exist for the proper identification and treatment of the impaired physician. Misconduct can be reported to state and local agencies. One must be sure to act in good faith with reasonable evidence when reporting such an incident. If a patient is at risk for immediate harm or injury by an impaired physician, one should assert authority and relieve the physician of the patient care and then address the problem with the senior hospital staff as soon as possible. The referenced article by Baldisseri is a review on the ethics of dealing with impaired healthcare professionals, with a focus on physicians.

 

648. A 78-year-old woman has a history of chronic low back pain. She denies any extremity problems. Her pain is worse in the morning, and gets better, although it does not go away, as the day goes on. An MRI scan of the lumbar spine is shown in Figure 88. She denies any acute worsening of her symptoms, although in general, her symptoms are slowly worsening. She takes nonsteroidal anti-inflammatory drugs as needed for her pain, but otherwise takes no other medications. What is the next most appropriate step in management?

 

1. DEXA scan
2. Brace treatment with a Jewett hyperextension brace
3. Anterior lumbar corpectomy and arthrodesis with instrumentation
4. Posterior lumbar decompression and fusion
5. Vertebral cement augmentation

 

Corrent answer: 1

 

The patient has MRI findings throughout her lumbar spine consistent with old compression fractures. Given the imaging findings and advanced age, she is at high risk for osteoporosis and subsequent fragility fractures. Management should consist of a DEXA scan to evaluate her degree of osteoporosis and

begin medical treatment as appropriate. Because acute fracture is unlikely, and she has no neurologic compromise, neither bracing nor surgical treatment is indicated.

 

649. Figure 10 is the radiograph of a middle-aged woman who has had midfoot pain for the past several years without antecedent trauma. What is the most likely etiology of her condition?

 

1. Osteomyelitis
2. Kohler disease
3. Rheumatoid arthritis
4. Primary osteoarthritis
5. Osteochondritis dissecans

 

Corrent answer: 3

 

The radiograph shows isolated degeneration in the talonavicular joint that is symmetric. The symmetry of the degeneration is characteristic of an inflammatory arthritis. In the absence of trauma, isolated arthritis in this joint is uncommon. The navicular is normal sized, ruling out Kohler disease (as well as the patient being in the wrong age group). There are no erosions indicative of osteomyelitis. Osteochondritis dissecans appears as focal osteochondral lesions, which are not present in the radiograph.

 

650. Figure 39 is the radiograph of a 67-year-old woman with rheumatoid arthritis who reports an 8-month history of increasing pain, swelling, and deformity. Anti- inflammatory drugs, orthotics, and extra-depth shoes have failed to provide relief. What is the next most appropriate step in treatment?

 

1. First metatarsophalangeal joint arthrodesis and lesser metatarsal head resections
2. First metatarsophalangeal joint replacement and lesser metatarsal head resections
3. Keller arthroplasty and lesser metatarsal head resections
4. Distal Chevron osteotomy and lesser metatarsal head resection
5. Lapidus procedure and Weil osteotomies

 

Corrent answer: 1

 

The patient has a severe rheumatoid forefoot deformity involving all metatarsophalangeal joints. Coughlin and Mann have found that 90% of patients have excellent and good results with combined first metatarsophalangeal fusion and lesser metatarsal head resection. Keller arthroplasty does not provide a stable platform for walking and is associated with recurrent deformity and pain. The first metatarsophalangeal joint replacement has not been shown to provide reliable long- term results. Osteotomies may be indicated in patients without erosive joint changes. The Lapidus procedure is an arthrodesis of the first tarsometatarsal joint, which would not address the patient's arthritic first metatarsophalangeal joint.

 

651. The operative report of a recent patient incorrectly documents the timing of peri-operative antibiotic administration. How should the

medical record be legally altered?

 

1. Obtain written approval from the hospital medical director
2. Obtain written approval from the risk management team
3. Obtain written approval from your lawyer and the senior partners of his law firm
4. No approval is needed, as you were the treating surgeon and have identified

the error

5. It is illegal to alter the medical record, but an addendum can be made

 

Corrent answer: 5

 

It is illegal to alter the medical record under any circumstance. If a documentation error has occurred, you may addend the medical record by identifying the error and noting the correction.

 

The review article by Bal discusses medical practice and highlights the four legal elements that must be proven in litigation: (1) a professional duty owed to the patient; (2) breach of such duty; (3) injury caused by the breach; and (4) resulting damages.

 

652. A 31-year-old woman underwent a left Kidner procedure 3 months ago. She now has pain overlying the medial column of the foot. She withdraws the foot when touching of the medial foot is attempted. Examination reveals allodynia, pain, hyperalgesia, and edema of the medial foot. What is the most likely diagnosis?

 

1. Shingles
2. Cellulitis
3. Charcot foot
4. Osteomyelitis
5. Reflex sympathetic dystrophy

 

Corrent answer: 5

 

Patients with reflex sympathetic dystrophy (RSD) have a history of trauma, minor rather than major (eg, Colles fracture), in about 50% to 65% of cases. The condition may also follow a surgical procedure. Patients usually have symptoms and signs of RSD including: pain, described as burning, throbbing, shooting, or aching; hyperalgesia; allodynia; and hyperpathia. There are trophic changes within 10 days of onset of RSD in 30% of the extremities affected, including stiffness and edema and atrophy of hair, nails, and/or skin.

Finally there can be autonomic dysfunction, such as abnormal sweating, either

in excess or anhydrosis, heat and cold insensitivity, or redness or bluish discoloration of the extremities. Shingles, also called herpes zoster or zoster, is a painful skin rash caused by the varicella zoster virus (VZV). VZV is the same virus that causes chickenpox. After a person recovers from chickenpox, the virus stays in the body.

Usually the virus does not cause any problems; however, the virus can reappear years later, causing shingles. Charcot arthropathy is a progressive condition of the musculoskeletal system that is characterized by joint dislocations, pathologic fractures, and debilitating deformities. This disorder results in progressive destruction of bone and soft tissues at weight-bearing joints; in its most severe form, it may cause significant disruption of the bony architecture. In patients with diabetes, the incidence of acute Charcot arthropathy of the foot and ankle ranges from

0.15% to 2.5%. Acute Charcot arthropathy almost always appears with signs of inflammation. Profound unilateral swelling, an increase in local skin temperature (generally, an increase of 3° to 7° above the nonaffected foot's skin temperature),

erythema, joint effusion, and bone resorption in an insensate foot are present. These characteristics, in the presence of intact skin and a loss of protective sensation, are often pathognomonic of acute Charcot arthropathy. Cellulitis is an infection of the skin.

Examination would reveal erythema, edema, and pain. Osteomyelitis is an infection of the bone. Examination may reveal edema, drainage, and pain.

 

653. Of the following variables, which has the strongest influence on external fixator stiffness?

 

1. Pin diameter
2. Pin spread
3. Bone quality
4. Stacking a second fixator bar
5. Distance from bone to fixator bar

 

Corrent answer: 1

 

Whereas all of the factors will have an impact on frame rigidity and stability, the single biggest factor is the pin diameter because it has an exponential effect.

 

654. Which of the following clinical scenarios represents the strongest indication for locked plating technique in a 70-year-old woman?

1. Segmentally comminuted ulnar fracture
2. Simple diaphyseal fracture of the humerus
3. Transverse midshaft displaced clavicle fracture
4. Periprosthetic femur fracture distal to a well-fixed total hip arthroplasty
5. Schatzker 2 fracture of the tibia with severe joint depression and comminution

 

Corrent answer: 4

 

Locking screw fixation is a relatively new option in the armamentarium of orthopaedic surgeons treating fractures. The understanding of the biomechanics, implications to healing, and optimal indications and surgical techniques is still in evolution. A periprosthetic proximal femur fracture with a stable prosthesis is best treated with open reduction and internal fixation with locking proximal fixation with or without cerclage cables. Diaphyseal fractures treated with compression plating or bridge plating can be treated well with conventional implants unless osteoporosis is severe. An AO/OTA B-type partial articular fracture is also better suited to standard buttress plating with periarticular rafting lag screws. Locking fixation is not always required for a transverse displaced midshaft clavicle fracture.

655. What is the post-amplification product of reverse transcription polymerase chain reaction (RT-PCR)?

 

1. RNA
2. DNA
3. Protein
4. Mitochondria
5. Immunoglobulins

 

Corrent answer: 2

 

Reverse transcription polymerase chain reaction (RT-PCR) is a variant of polymerase chain reaction (PCR) used in molecular biology to generate many copies of a DNA sequence from fragments of RNA. The RNA strand is first reverse transcribed into its DNA complement, followed by amplification of the resulting DNA using polymerase chain reaction. Polymerase chain reaction amplifies short segments of DNA by using the temperature stable DNA polymerase enzyme.

 

656. A 63-year-old woman falls from standing and lands on her right hand. She complains of deformity and wrist pain. Radiographs are provided in Figure A. Following closed reduction, the patient inquires whether she has osteoporosis and if she is likely to have another fracture. In counselling the patient, which of the following is the strongest predictor for a future fracture from low energy trauma?

 

1. Bone mineral density T-score < -2.5
2. Low vitamin D levels
3. Family history of osteoporosis
4. History of a prior fragility fracture
5. Ten year history of oral prednisone use

 

Corrent answer: 4

 

Each of the answer choices is a risk factor for subsequent fragility fracture, but patient history of a prior fragility fracture is the strongest predictor.

 

Bouxsein et al reviews the proper care, diagnosis, and prevention of fragility fractures. History of a fragility fracture is the greatest predictor of a future fracture from low energy trauma. Appropriate care includes not only treatment of the fracture itself, but also proper evaluation to identify the etiology of the fracture and appropriate intervention to rectify the underlying pathology. Evaluation includes bone densitometry, lab testing of Vitamin D and calcium.

A T-score compares your bone density to the optimal peak bone density for your gender. It is reported as number of standard deviations below the average. A T-score of -1 to -2.5 is considered osteopenia, and a risk for developing osteoporosis. A T- score of less than -2.5 is diagnostic of osteoporosis.

 

657. Long-term alendronate (Fosamax) use for osteoporosis has been associated

with which of the following?

 

1. Scurvy
2. Detached retina
3. Uterine carcinoma
4. Osteonecrosis of the femoral head
5. Diaphyseal femoral insufficiency fractures

 

Corrent answer: 5

 

Alendronate is a bisphosphonate that inhibits the ruffled border of the osteoclast. When used long term, this class of medication prevents the normal bone remodeling process. Long-term use has recently been shown to be associated with insufficiency fractures of the femur. Osteonecrosis of the jaw has been described but not in other anatomic locations. Scurvy occurs because of a lack of vitamin C and use of bisphosphonates is not associated with

uterine cancer or a detached retina.

 

658. Implants composed of polylactic acid are excreted by what system after they are absorbed?

 

1. Hepatic
2. Renal
3. Respiratory
4. Gastrointestinal

 

Corrent answer: 3

 

Polylactic acid suture and suture anchors are popular bioabsorbable orthopaedic implants. This material undergoes hydrolysis of the ester background in vivo. Resulting lactic acid enters the tricarboxylic acid (Krebs)

cycle and is excreted as carbon dioxide by the lungs. Polyglycolic acid and poly(p- dioxanone) may also be excreted by the kidneys.

 

659. A patient sustains a grade III medial collateral ligament injury. One year later, when compared to collagen in an uninjured ligament, an increase is likely in the

 

1. gross number of fibers.
2. proportion of type III fibers.
3. cross-linking.
4. mass and diameter of fibers.

Corrent answer: 1

Studies on animal models have shown that there is a change in collagen fiber type and distribution early in the healing process. There is a higher portion of type III fibers than in

normal ligament initially, but this ratio returns to normal about 1 year after the injury occurs. Healing ligaments show an increased number of collagen fibers, but the number of mature collagen cross-links is

45% of predicted value after 1 year. There is also a decrease in the mass and diameter of the collagen fibers.

 

660. Sclerostin and dickkopf-1 (Dkk-1) are direct inhibitors of what pathway related to bone and/or cartilage regulation?

 

1. Bone morphogenetic protein (BMP)/SMAD pathway
2. Receptor activator of nuclear factor kappa beta (RANK)/RANK ligand (RANKL) pathway
3. Wnt/Beta-catenin (&#223;-catenin) pathway
4. Parathyroid hormone (PTH) pathway

 

Corrent answer: 3

 

Dkk-1 and sclerostin are proteins that inhibit the binding of the Wnt molecule to receptors LRP5/6. In the absence of sclerostin and Dkk-1, Wnt binds to its receptor, which in turn inhibits phosphorylation of the ß-catenin. The unphosphorylated ß-catenin then builds up in the cytoplasm of the cell, allowing it to be transported to the nucleus of the cell. Once in the nucleus, ß- catenin will lead to upregulation of a series of proteins involved in osteoblast formation differentiation. Knocking out or inhibiting sclerostin or Dkk-1 results  in increased bone mass secondary to constitutive activation of the Wnt/ß- catenin pathway. The other responses are not directly affected by Dkk-1 or sclerostin. RANKL and RANK are expressed on osteoblasts and osteoclasts, respectively, and are involved in osteoblast-mediated osteoclast activation. BMPs work through SMADs to cause osteoblastic differentiation, and there is reported crosstalk between the Wnt and BMP pathways (but this is an indirect link). Finally, PTH at physiologic levels binds to osteoblasts, causing a series of events that lead to osteoblast-mediated osteoclast activation and subsequent increased bone resorption.

 

661. During endochondral ossification of the growth plate, the process that most contributes to the longitudinal growth of long bones is

 

1. chondrocyte apoptosis.
2. chondrocyte hypertrophy.
3. chondrocyte proliferation.
4. growth plate matrix synthesis.

Corrent answer: 2

The growth plate is divided into 5 distinct zones: reserve, proliferative, maturation, hypertrophy, and vascular invasion. During growth-plate chondrocyte hypertrophy, intracellular volume and an increase in chondrocyte height are responsible for most growth of long bones. Other factors that contribute to bone growth are chondrocyte proliferation and matrix synthesis, but to a lesser degree than chondrocyte hypertrophy. Growth plate chondrocytes undergo programmed cell death (apoptosis) after hypertrophy

takes place.

 

662. Bacterial resistance to tetracycline is confirmed by ribosome protection, tetracycline modification, and

 

1. altered RNA polymerase.
2. altered membrane binding protein.
3. increased drug efflux.
4. DNA gyrase mutation.

Corrent answer: 3

Mutations of bacterial DNA gyrase can decrease the effectiveness of quinolones. Altered membrane-binding protein is observed with resistance to ?

-lactam antibiotics. Tetracyclines are antibiotics that inhibit bacterial growth by stopping protein synthesis. Three specific mechanisms of tetracycline

resistance have been identified: increased tetracycline efflux, ribosome protection, and tetracycline modification. Alteration of RNA polymerase is found in resistance to rifampin.

 

663. A 14-year-old boy has failed physical therapy management for Scheuermann kyphosis, and an extension thoracolumbosacral orthosis brace is recommended. The boy and his parents are told that the brace will force his thoracic spine into normal sagittal alignment and put the anterior vertebral bodies of the thoracic segment into tension, which will induce bone growth and normalization of wedge- shaped

vertebrae. What name is associated with this process?

 

1. Hooke's law
2. Kirchhoff's law
3. Wolff's law
4. Heuter-Volkmann principle

 

Corrent answer: 4

 

The Heuter-Volkmann principle shows that bone placed in longitudinal tension will tend to stimulate longitudinal growth, and that compressive longitudinal forces inhibit longitudinal growth, making this response the best choice. Hooke's law relates to stress being proportional to strain and is not directly related to bone growth. Kirchhoff's laws apply to electrical circuit design. Wolff's law states that bone remodels in response to mechanical stress, with the correlate that increased stress causes increased growth, and decreased stress leads to bone loss.

664. A tendon repair is thought to be weakest during which phase of tendon healing?

 

1. Inflammatory
2. Proliferation
3. Maturation
4. Remodeling

Corrent answer: 1

 

Healing after a tendon repair or rupture has the following stages: inflammatory, cellular proliferation, and remodeling. During the inflammatory phase, neutrophils and macrophages migrate into the injury site and release chemotactic factors that recruit fibroblasts. A tendon is thought to be weakest

5 to 21 days after repair, which coincides with the inflammatory phase. During the proliferative phase, inflammatory cells secrete cytokines and growth

factors (platelet-derived growth factor, insulin-like growth factor, bone morphogenetic protein (BMP)-12 and BMP 13, and transforming growth factor- beta) that promote differentiation of fibroblasts. Fibrosis and decreased cellularity are the hallmarks of the remodeling stage.

 

665. A 4-year-old boy has bilateral genu varum and is in the fifth percentile for height for his age. A younger sister has less severe genu varum. Radiographs reveal physeal cupping and widening on both the distal femur and proximal tibia. Laboratory studies show sodium 145 mEq/L (reference range, 136-142 mEq/L), potassium 4.0 mEq/L (reference range, 3.5-5.0 mEq/L), calcium 9.0 mg/dL (reference range, 8.2-10.2 mg/dL), phosphorous 2 mg/dL (reference range, 4-

6.5 mg/dL), vitamin D 50 ng/mL (reference range, 30-100 ng/mL), and urine phosphorus 2 g/24-hour collection (reference range, 0.4-1.3 g). What effect would treatment with only Calcitriol (1,25 dihydroxy vitamin D3) have?

 

1. Restore normal limb alignment
2. Restore normal limb alignment and height
3. Have no effect on limb alignment and height
4. Stabilize degree of genu varum, but not improve limb alignment

 

Corrent answer: 3

 

This patient has familial hypophosphatemic rickets, a vitamin D-resistant form of rickets that is an X-linked inherited disorder. Patients are short (< 10th percentile). Varus occurs both in the distal femur and proximal tibia. Patients have increased urinary excretion of phosphorus, leading to hypophosphatemia. Calcium levels are within defined limits and vitamin D levels can be normal as well. Treatment should include phosphate and 1,25 dihydroxy vitamin D3 (calcitriol). Phosphate administration increases the plasma concentration,

which lowers plasma ionized calcium concentration and further reduces plasma calcitriol concentration (removal of hypophosphatemic stimulus). Secondary hyperparathyroidism results because of both hypocalcemia and removal of the

normal inhibitory effect of calcitriol on parathyroid hormone (PTH) synthesis. Elevated PTH levels will increase urinary phosphate excretion, defeating the aim of oral therapy.

Addition of calcitriol is necessary to increase the intestinal absorption of calcium and phosphate to prevent secondary hyperparathyroidism. Massive doses of vitamin D alone can restore normal radiographic appearances to the epiphyses, but normal growth is not restored unless phosphate replacement is adequate.

 

666. A 35-year-old woman began to train for a half marathon. After 8 weeks of increasing her mileage, what changes can you expect in her Achilles tendon?

 

1. Net decrease of type I collagen
2. Net increase of type I collagen
3. Increased diameter of collagen fibrils
4. Increased cross-sectional area of the tendon

 

Corrent answer: 2

 

Training increases turnover of type I collagen, promoting both synthesis and degradation of collagen and a net increase synthesis of type I collagen in tendon-related tissue.

Strenuous endurance training has resulted in decreased collagen cross-links, suggesting increased collagen turnover, but decreased collagen maturation. In human studies, physical training results in increased turnover of collagen. Synthesis and degradation are elevated initially when beginning an exercise program, but degradation products decrease overall. It is not known if activity levels in humans affect the diameter of collagen fibrils or the cross-sectional area of tendons.

1. FOR ALL MCQS CLICK THE LINK ORTHO MCQ BANK