Question 1

Which of the following is the proper sequence (or order) of the classes of macromolecules in articular cartilage in regard to the percentage of dry weight of the components (highest to lowest):

Explanation

Articular cartilage has three principal classes of macromolecules: Collagen – 60% Proteoglycans – 25% to 35% Noncollagenous proteins/glycoproteins – 15% to 20%

Question 2

Which of the following articular cartilage collagens form cross-banded fibrils:

Explanation

Three articular cartilage collagens that form cross bands are types II, IX, and XI. Of particular note: Type XI binds to type II. Type IX binds to the cross-banded fibrils in the superficial layer. Type VI attaches to the matrix around the chondrocytes. Type X is near the calcified layer and is probably involved in mineralization of the calcified layer.

Question 3

Which of the following molecules binds with type II collagen and may aid in the stabilization of the type II collagen network in articular cartilage:

Explanation

Decorin and fibromodulin bind to type II collagen and likely stabilize the type II collagen network. The other responses refer to: Biglycan: Binds with type VI collagen Anchorin C II: Helps attach chondrocytes to the collagen fibrils COMP: Binds to chondrocytes

Question 4

A high collagen concentration and a low proteoglycan concentration is found in which of the following zones of articular cartilage:

Explanation

The superficial zone has a number of important characteristics: Thinnest articular cartilage layer Two layers: Most superficial – fine collagen fibrils (lamina splendens) Deep layer – flattened fibroblast-like chondrocytes (parallel to joint surface) Forms a cartilage skin Important chemical properties: High collagen and low proteoglycan concentration Fibronectin and water concentrations are highest in this zone Great tensile stiffness and strength Seals off the cartilage from the immune system

Question 5

A high concentration of fibronectin and water is found in which of the following articular cartilage zones:

Explanation

The superficial zone has a number of important characteristics: Thinnest articular cartilage layer Two layers: Most superficial – fine collagen fibrils (lamina splendens) Deep layer – flattened fibroblast-like chondrocytes (parallel to joint surface) Forms a cartilage skin Important chemical properties: High collagen and low proteoglycan concentration Fibronectin and water concentrations are highest in this zone Great tensile stiffness and strength Seals off the cartilage from the immune system

Question 6

Which of the following zones of the articular cartilage most likely seals the cartilage off from the immune system:

Explanation

The superficial zone has a number of important characteristics: Thinnest articular cartilage layer Two layers: Most superficial – fine collagen fibrils (lamina splendens) Deep layer – flattened fibroblast-like chondrocytes (parallel to joint surface) Forms a cartilage skin Important chemical properties: High collagen and low proteoglycan concentration Fibronectin and water concentrations are highest in this zone Great tensile stiffness and strength Seals off the cartilage from the immune system

Question 7

Which of the following statements is true concerning the transitional zone of articular cartilage:

Explanation

The transitional zone lies between the superficial and middle zones of the articular cartilage. The following important points should be remembered: The chondrocytes have a high concentration of synthetic organelles such as rough endoplasmic reticulum and Golgi apparatus. The collagen fibers are larger than in the superficial zone. The proteoglycan concentration is higher than the superficial zone.

Question 8

The chondrocytes in which of the following articular cartilage zones have the lowest metabolic activity:

Explanation

The chondrocytes in the calcified cartilage zone show the least metabolic activity. In contrast, the chondrocytes of the other areas are very active: Superficial zone Fine collagen fibrils (lamina splendens) High collagen and low proteoglycan concentration Fibronectin and water concentrations are highest in this zone Transitional zone The chondrocytes have a high concentration of synthetic organelles such as rough endoplasmic reticulum and Golgi apparatus. The collagen fibers are larger than in the superficial zone. The proteoglycan concentration is higher than the superficial zone. Middle (radial or deep) zone Largest diameter collagen fibrils Highest proteoglycan content

Question 9

Which of the following molecules causes the expression of matrix metalloproteinases that can degrade the articular cartilage extracellular matrix:

Explanation

Interleukin I has the potential to increase expression of matrix metalloproteinases that can dissolve the extracellular matrix. The other responses are anabolic factors: Insulin-dependent growth factor I Transforming growth factor beta Bone morphogenetic protein 2 Bone morphogenetic protein 7

Question 10

Which of the following resist tensile and shear deformation forces in articular cartilage:

Explanation

Type II collagen fibers resist tensile and shear deformation forces in the articular cartilage. In contrast, the glycosaminoglycan aggregates resist articular cartilage compression and fluid flow.

Question 11

Which of the following resist articular cartilage compression and fluid flow:

Explanation

Type II collagen fibers resist tensile and shear deformation forces in the articular cartilage. In contrast, the glycosaminoglycan aggregates resist articular cartilage compression and fluid flow.

Question 12

Which of the following stimulates aggrecan core protein and glycosaminoglycan synthesis:

Explanation

Cyclic compressive loads have the ability to stimulate matrix synthesis â aggrecan core protein and the glycosaminoglycans. The other responses are catabolic toward the cartilage â break the cartilage down: Tumor necrosis factor Interleukin I Matrix metalloproteinases Chronic compressive loads outside the physiologic range Static compression (eg, putting a patient in a cast)

Question 13

Which of the following are characteristic of osteoarthritis:

Explanation

The characteristic findings in osteoarthritis are: Asymmetric loss of the joint space Subchondral sclerosis and cysts Osteophyte formation As the cartilage degenerates, progressive bone remodeling occurs. The other responses refer to other synovial proliferative disorders: Pigmented villonodular synovitis: Synovial proliferation, cysts/erosions on both sides of the joint Rheumatoid arthritis: Synovial proliferation with lymphocytic infiltration, periarticular osteopenia, symmetric joint space loss Charcot neuropathy: Subluxation, bone fragmentation, dissolution of the articular surfaces Gout: Periarticular erosions, soft tissue masses, preservation of the articular surfaces

Question 14

Which of the following chemical changes occur in the first phase (earliest) of osteoarthritis:

Explanation

The cause of osteoarthritis is unknown. From a chemical standpoint, one of the earliest findings is a decrease in the proteoglycan and an increase in the water content. One should remember: Constant type II collagen content Decreased proteoglycan concentration and decreased chain length Increased water content The decreased proteoglycan content results in increased permeability of the cartilage. A reduction of the stiffness makes the articular cartilage less able to bear loads.

Question 15

Which of the following is characteristic of the second stage of osteoarthritis:

Explanation

The cause of osteoarthritis is unknown. From a chemical standpoint, one of the earliest findings is a decrease in the proteoglycan and an increase in the water content. One should remember: Constant type II collagen content Decreased proteoglycan concentration and decreased chain length Increased water content In the second stage, there is a cellular response â chondrocyte proliferation. C lusters of chondrocytes producing new matrix are visible. In this stage, there is nitric oxide and interleukin I production. These are catabolic factors that increase matrix metalloproteinase activity. Degradative enzymes break down types IX and XI collagen, which may compromise the stability of the type II collagen framework.

Question 16

Which of the following is characteristic of the second stage of osteoarthritis:

Explanation

The cause of osteoarthritis is unknown. From a chemical standpoint, one of the earliest findings is a decrease in the proteoglycan and an increase in the water content. One should remember: Constant type II collagen content Decreased proteoglycan concentration and decreased chain length Increased water content In the second stage, there is a cellular response â chondrocyte proliferation. C lusters of chondrocytes producing new matrix are visible. In this stage, there is nitric oxide and interleukin I production. These are catabolic factors that increase matrix metalloproteinase activity. Degradative enzymes break down types IX and XI collagen, which may compromise the stability of the type II collagen framework.

Question 17

Which of the following is characteristic of the second stage of osteoarthritis:

Explanation

The cause of osteoarthritis is unknown. From a chemical standpoint, one of the earliest findings is a decrease in the proteoglycan and an increase in the water content. One should remember: Constant type II collagen content Decreased proteoglycan concentration and decreased chain length Increased water content In the second stage, there is a cellular response â chondrocyte proliferation. Clusters of chondrocytes producing new matrix are visible. In this stage, there is nitric oxide and interleukin I production. These are catabolic factors that increase matrix metalloproteinase activity. Degradative enzymes break down types IX and XI collagen, which may compromise the stability of the type II collagen framework.

Question 18

Which of the following is characteristic of the third and final stage of osteoarthritis:

Explanation

In the last stage of osteoarthritis, there is reduced chondrocyte proliferation and function, which may be secondary to reduced ability to respond to anabolic factors (down regulation). There may be accumulation of molecules that bind to the anabolic factors (and keep the factors from the chondrocytes) such as decorin and insulin-dependent growth factor binding protein.

Question 19

Three years ago, a patient underwent successful resection of a third web space neuroma. She now presents with identical symptoms in the same location. She requests surgery because all attempts at conservative care have failed. Recommended treatment includes:

Explanation

The recurrence rate of a previously resected neuroma is approximately 15%. The deep transverse metatarsal ligament is involved in the pathogenesis of a primary, but not a recurrent, neuroma. None of the present symptoms suggests tarsal tunnel syndrome, although this may exist concurrently with a neuroma. Phenol has ablative neural properties, but it cannot be injected due to the local effect on tissue necrosis.

Question 20

A 72-year-old woman presents for treatment of a painful hallux valgus deformity. On examination of the foot, crepitus is present to range of motion of the hallux. Pain upon compression of the joint is also present. The hallux valgus angle is 45Â° and the intermetatarsal angle is 20Â°. The recommended surgical procedure is:

Explanation

In the presence of metatarsalphalangeal joint arthritis, either resection arthroplasty or arthrodesis is recommended. However, with this degree of intermetatarsal deformity, a resection arthroplasty may lead to a high recurrence rate of hallux valgus deformity.

Question 21

Resection of the tibial sesamoid may result in which deformity of the hallux:

Explanation

The abductor hallucis muscle attaches to the tibial sesamoid and resection without repair of the abductor and medial capsule may lead to hallux valgus. Hallux varus may occur after resection of the fibular sesamoid, and a cock- up extension hallux deformity occurs after resection of both sesamoids or with a rupture of the volar plate.

Question 22

Arthrodesis of the ankle in a 34-year-old woman should be performed with the ankle positioned in:

Explanation

Although the woman may wish to wear shoes of varying height, there is sufficient plantarflexion occurring through the transverse tarsal joint to permit the wearing of high-heel shoes. Any plantarflexion of the fusion will cause arthritis of the transverse tarsal joint, particularly the talonavicular joint. Dorsiflexion of an ankle arthrodesis is associated with a calcaneus position and heel pain. The ankle should be fused in a similar position for both male and female patients.

Question 23

A 27-year-old male athlete presents with a 2-month history of pain along the posteromedial ankle. Swelling is present posteriomedially. The pain is exacerbated with resisted plantarflexion and inversion of the foot. This condition is likely to be associated with:

Explanation

The presence of posterior tibial tendonitis in a young individual should raise the concern for seronegative arthritis. Although a stress fracture of the medial malleolus may be present, pain is not exacerbated with resisted inversion.

Question 24

A 23-year-old collegiate athlete presents for evaluation of recurrent ankle pain associated with ankle sprains. Upon examination, pain is present along the lateral ankle, an anterior drawer test is negative, and marked instability is apparent with inversion stress of the ankle. Stress radiographs are normal. The most likely cause of the patientâ s symptoms is:

Explanation

Subtalar instability is not common, although a component of instability may be present in conjunction with ankle instability. If symptoms are suggestive of ankle instability but cannot be verified upon clinical or radiographic examination, then subtalar instability is likely to be present. The clinical diagnosis of subtalar instability is difficult.

Question 25

A 46-year-old nurse presents for treatment of pain in the heel. The pain has been present for 6 months and increases upon rising from bed and after sedentary periods. The pain is focal and reproduced with pressure over the proximal medial heel. The initial treatment most likely to be associated with relief of symptoms is:

Explanation

With the exception of physical therapy and a rigid orthotic support, most of the treatment alternatives would be helpful in the initial treatment of plantar fasciitis. Achilles stretching combined with a soft, gel-type heel cushion is consistently the most successful modality.

Question 26

A 72-year-old man presents for evaluation and treatment of pain and limited motion in his arthritic ankle and subtalar joint. The foot is plantigrade with respect to the leg. Radiographs demonstrate ankle arthritis, an absent joint space, no malalignment of the tibiotalar joint, and a normal subtalar joint. The most reliable surgical procedure consistent with maintaining increased activity and patient function is:

Explanation

Ankle replacement is a treatment alternative that is widely recommended today, although it is still not as reliable as an ankle arthrodesis in terms of predictability and absence of complications. One must consider the option of arthrodesis and replacement carefully with each patient.

Question 27

A 37-year-old construction worker presents for evaluation and treatment of a painful stiff foot. He has noticed the stiffness for approximately 12 years, and particularly feels the stiffness when he is working on uneven ground surfaces. Upon clinical and radiographic examination, he is noted to have a calcaneonavicular coalition without any peritalar arthritis. Your recommended treatment is:

Explanation

Although arthrodesis has proved reliable with respect to managing tarsal coalition in the adult, resection of a calcaneonavicular coalition should be performed whenever possible. This procedure is preferable to a triple arthrodesis. A subtalar arthrodesis would be applicable as treatment for a middle facet coalition in the adult.

Question 28

A 28-year-old male runner presents for treatment of a painful lesion under the first metatarsal head (located more toward the medial aspect of the metatarsophalangeal joint). The lesion is associated with painful callosity to palpation, normal hallux function, and a normal position of the first metatarsal. Attempts to relieve the pressure with orthoses and shoe modifications have not been successful. The ideal treatment is:

Explanation

Planing or shaving of the sesamoid is a reliable procedure for treatment of a specific focal keratosis beneath the tibial sesamoid. Resection of the tibial sesamoid is a reasonable alternative, although it should be used only for pathology of the sesamoid itself. In this individual, the position of the first metatarsal is normal. Since no plantarflexion is present, an osteotomy is not indicated.

Question 29

A 29-year-old football player twisted his foot 1 year ago, and he recalls pain and swelling of the midfoot at the time of the injury. No definitive treatment was provided at that time. Although he returned to athletic activity, he has experienced constant pain and occasional swelling. The pain is present upon passive pronation and abduction of the midfoot, and radiographs demonstrate that there is a 2.5-mm gap between the base of the first and second metatarsal and medial and middle cuneiform. Initial management should include:

Explanation

The patientâ s history and clinical findings indicate an injury to the tarsometatarsal joint complex, specifically between the middle and the medial columns. Although surgery may become necessary, initial treatment should consist of support. Physical therapy will worsen foot pain and injection is not indicated.

Question 30

A 44-year-old man has a 2-year history of pain in his hallux. The pain is accompanied by limited range of motion, pain on passive dorsiflexion of the hallux, and difficulty with athletic activities. Radiographs demonstrate that the plantar two-thirds of the joint is normal, with osteophytes of the dorsal surface of the joint. He has been unsuccessful with shoe wear modifications, and he requests surgery. The ideal procedure for him would be:

Explanation

Preservation of the joint and maintaining range of motion are important to any active individual. Any procedure, such as resection or implant arthroplasty, is contraindicated in this age group. Arthritis has not progressed to the degree that arthrodesis is necessary.

Question 31

A 32-year-old woman with a history of diabetes presents with a 1-month history of painless swelling in the foot. The foot is swollen, warm, and erythema is present in the midfoot. She has no fever and her blood sugars are normal. Radiographs demonstrate the presence of fracture and dislocation of the tarsometatarsal joint. There are no new periosteal bone formations, and complete dorsal dislocation of the metatarsals on the cuneiforms is noted. The ideal treatment is:

Explanation

If there is a contraindication to performing surgery, nonoperative methods of treatment for an acute C harcot neuroarthropathy may be acceptable. This patientâ s midfoot is dislocated and is likely to result in a worsening deformity over time, with ulceration and infection possible. Open reduction with internal fixation has not proven sufficient in patients presenting with the symptoms indicated in the scenario. Arthrodesis is most likely to yield a satisfactory outcome.

Question 32

A 54-year-old woman presents with a 1-year history of medial foot and ankle pain. She does not recall an episode of trauma, and she has had no change in her daily living activities. Her foot is changing shape; it is flatter than the opposite foot. On clinical examination she has a unilateral flatfoot deformity, an inability to perform a single heel rise, and weak inversion strength. The subtalar joint is flexible. Following an initial period of support of the foot, surgery is recommended. The ideal procedure is:

Explanation

This patient has a rupture of the posterior tibial tendon. Repair of the tendon will not work because there is a degenerative elongation of the tendon that will not heal. Because the foot is flexible, arthrodesis is not necessary. Flexor digitorum longus transfer with calcaneal osteotomy is a reliable procedure for treatment of Stage II posterior tibial tendon insufficiency.

Question 33

The anatomic structure responsible for the development of an interdigital neuroma is:

Explanation

The deep transverse metatarsal ligament passes between the undersurface of the metatarsal heads and connects the volar plate to the adjacent soft tissue structures. The common digital nerve becomes irritated under the sharp edge of the distal portion of the ligament, resulting in nerve swelling and formation of the neuroma.

Question 34

A 14-year-old boy with a painful flatfoot deformity presents for evaluation and treatment. He has had pain of the midfoot associated with thickening, callosity, and shoe wear. Shoe wear modifications, orthoses, and restriction of activity have not been successful. On examination, he has a very flexible flatfoot deformity. The hindfoot and midfoot are passively correctable, the subtalar and transverse tarsal joints are mobile, and callosity is present over the talar head. The recommended treatment is:

Explanation

It is unusual for an adolescent to require surgical correction of a flatfoot deformity, however, when the deformity is markedly symptomatic, surgery is a reasonable treatment option. Arthrodesis should not be considered as treatment of the flexible flatfoot in the adolescent. There is no indication of an accessory navicular bone being present. Lateral column lengthening (Evans Procedure) is a reliable procedure in this age group. The most common correction in kids with severe flexible pes planus is a lateral column lengthening. This is because most children, such as in this case, have severe forefoot abduction with significant talo-navicular uncoverage. (The description stated that the patient had a callus under the talar head, which means the talus is protruding beyond the navicular medially.) Medial slide calcaneal osteotomy would only correct the heel valgus, whereas a lateral column lengthening has the potential to correct both heel valgus and forefoot abduction.

Question 35

A 23-year-old woman with juvenile rheumatoid arthritis presents for treatment of painful forefoot deformity. Painful hallux valgus is present and is associated with dislocation of the lesser metatarsophalangeal joints. The recommended surgical treatment is:

Explanation

The gold standard surgical treatment for rheumatoid patients with severe forefoot deformities is first metatarsophalangeal fusion with second through fifth metatarsal head resections.

Question 36

The most common complication following triple arthrodesis in the adult patient is:

Explanation

Each of the possible answers may occur following triple arthrodesis. In numerous studies, ankle arthritis is the complication most likely to occur regardless of the underlying disease process.

Question 37

A pantalar arthrodesis is described as a:

Explanation

A pantalar arthrodesis is the combination of an ankle and triple arthrodesis. It should not be confused with an ankle and subtalar arthrodesis (tibiotalocalcaneal).

Question 38

A 23-year-old woman with a bilateral leg and foot deformity presents for evaluation. She has weakness in the foot and ankle, giving way of the ankle, and difficulty with exercise activities. She mentions that both her brother and uncle have similar problems and deformities with their limbs. On examination, she has a cavovarus foot deformity and muscle weakness. The most likely combination of muscle loss is:

Explanation

By history, this patient has hereditary sensorimotor neuropathy (C harcot- Marie-Tooth disorder). Historically referred to as peroneal muscular atrophy, this condition initially affects the peroneus brevis, followed by the intrinsic and anterior tibial muscles. Other patterns of deformity and muscle loss are occasionally present.

Question 39

A 63-year-old woman presents for evaluation and treatment of a painful bunion deformity. She has a moderate hallux valgus deformity. Pain and crepitus are present with range of motion of the hallux metatarsophalangeal joint. The hallux valgus deformity measures 25Â° and the intermetatarsal angle is 14Â°. The recommended surgical procedure is:

Explanation

Although resection arthroplasty (Keller procedure) may be a reasonable alternative, arthrodesis of the hallux metatarsophalangeal joint is required in the presence of arthritis. Other alternatives, such as osteotomies, are impractical.

Question 40

The nerve commonly associated with painful heel syndrome is the:

Explanation

The first branch of the lateral plantar nerve (occasionally referred to as the nerve to the abductor digiti quinti) is occasionally involved in pathologic painful heel syndrome and plantar fasciitis.

Question 41

A 63-year-old woman with diabetes has had an ulcer under the plantar aspect of the foot for 3 months. The ulcer extends from the inferior aspect of the heel pad toward the midfoot. Nonoperative measures have failed to heal the ulcer. The amputation that is most likely to be successful is a:

Explanation

A foot salvage amputation, including the transarticular ankle amputation (Symeâ s amputation), will not work in the presence of a disrupted heel pad (with or without ulceration) and infection of the heel.

Question 42

A 56-year-old man has a painful flatfoot deformity. Attempts at orthotic support and bracing of the foot have not been successful. On examination, the forefoot is abducted, the heel is fixed in valgus, and the subtalar joint is rigid. The operation that is most likely to correct the foot deformity is:

Explanation

By history and physical examination, this patient has a Stage III flatfoot deformity. Due to the rigidity, only an arthrodesis will correct this abnormality. Although a transverse tarsal arthrodesis (Choparts arthrodesis) may adequately correct the deformity, a triple arthrodesis will correct all of the components including heel valgus, forefoot abduction, and midfoot pronation.

Question 43

A 54-year-old woman with a 10-year history of diabetes presents for treatment of a non-healing ulcer that has been present under the plantar aspect of her second metatarsal for 9 months. The ulcer is 1.5 cm in diameter, is associated with mild serous drainage, and has shown no radiographic changes. She has normal circulation to the forefoot. The recommended treatment is:

Explanation

Management of the non-infected plantar neuropathic ulcer is nonoperative, with the exception of refractory recurrent ulceration. In this case, surgery may be indicated. The most reliable means of healing the ulcer is with the use of a total contact cast that permits immediate ambulation and protection for the rest of the foot. Shoe modifications are required following healing of the ulcer but are insufficient as part of the initial treatment program.

Question 44

A patient presents for treatment in your emergency department following an injury that he sustained 4 hours earlier. His foot was run over by a piece of heavy industrial equipment. On examination, he has pain in the foot, a displaced fracture of the second metatarsal, a 3-cm area of severe contusion over the forefoot, and numbness of the dorsal surface of the foot. The next examination that you recommend is:

Explanation

Because of his history, this patient may have a compartment syndrome of the foot. Although other studies may be relevant as part of his evaluation, a compartment syndrome mandates emergency treatment. Vascular evaluation, including laser Doppler flowmetry is unreliable in diagnosing compartment syndrome. Imaging studies may be performed as part of the surgical work-up, but they are not indicated at this time.

Question 45

A 63-year-old woman presents for treatment of pain and a burning/tingling sensation along the medial aspect of the foot and hallux. She underwent a tarsal tunnel release 12 months ago, but she has not experienced much symptomatic relief. Upon clinical examination, she has a positive percussion test (Tinel sign) along the course of the distal tibial nerve and pain upon pressure of the tarsal canal. There are no other pertinent clinical findings and a magnetic resonance image does not reveal any pathologic lesion. The next course of treatment is:

Explanation

This patient presents with symptoms of a tarsal tunnel syndrome, specifically involving the medial plantar nerve. Because she did not experience any initial pain relief from her surgery, one may suspect that an inadequate release was initially performed. Cortisone injection and physical therapy have no role in the management of a recurrent tarsal tunnel syndrome, although desensitization treatments with neuroleptic medication and manual massage are beneficial following surgery. It is important to rule out a sympathetically mediated pain syndrome prior to embarking on repeat surgery.

Question 46

For 3 years, a 23-year-old female gymnast has experienced recurrent ankle sprains associated with a sense of instability of the hindfoot. Upon examination, a positive anterior drawer test is present and stress radiographs are taken. She has attempted rehabilitation numerous times. She is unable to compete with her current symptoms. The recommended treatment is:

Explanation

For athletes, particularly those involved in activities that require repetitive proprioceptive and balance activities of the foot and ankle, an anatomic repair (Brostrom procedure) with addition of the extensor retinaculum (Gould modification) is the only procedure that will allow this individual to return to athletic activity. Surgeons must not sacrifice the peroneal tendon, or part thereof, since this may unnecessarily weaken the foot. Orthopedic Prometric Exam Question

Question 47

A 31-year-old recreational soccer player presents for evaluation of chronic ankle pain during physical activity. He reports a severe inversion ankle sprain that occurred 1 year ago and notes that he was treated with cast immobilization. Upon examination, he does not demonstrate laxity of the ankle ligaments and pain is present along the anterior medial ankle. A radiograph is presented. The recommended treatment is:

Explanation

This patient has an osteochondral defect of the talus. According to most classification systems, the grade of the defect is not severe. Retrograde drilling of the defect through the sinus tarsi is possible for a posteromedial lesion of the talus for which the cartilage surface is intact. An autogenous osteochondral bone graft is indicated for a severe lesion with bone loss or following failure of previous attempts at arthroscopic drilling. The ideal procedure is arthroscopic debridement and drilling of the subchondral bone.

Question 48

A 43-year-old woman has had a 2-year history of ankle pain. Her ankle pain is associated with swelling, decreased activities, and limited range of motion. Upon examination, diffuse warmth and swelling of the ankle are noted. Radiographs and a clinical picture are presented. The most likely diagnosis is:

Orthopedic Prometric Exam Question

Explanation

Although pigmented villonodular synovitis (PVNS), infection, or gout may cause inflammatory changes on both sides of the ankle joint, the most likely cause of this inflammatory arthropathy is rheumatoid arthritis. Note the cystic changes, the synovial hypertrophy, and the joint inflammation.

Question 49

A 25-year-old football player sustained an injury to his ankle 2 months ago. He has ankle pain upon dorsiflexion and external rotation. A radiograph demonstrates widening of the tibiofibular syndesmosis and a 3-mm space between the medial talus and the medial malleolus. The recommended treatment is:

Explanation

It is imperative that any diastasis of the tibiofibular joint is repaired to prevent the late sequelae (e.g., arthritis), particularly in the athlete. Arthroscopy is not sufficient, other than evaluation for additional joint pathology, and syndesmosis arthrodesis would rarely be indicated for this condition. There is no evidence of a high fibula fracture, although this must be a concern and should always be considered.

Question 50

A patient presents for surgical treatment of a third web space neuroma. She inquires as to the potential for complications from the procedure. You inform her that the recurrence rate following excision is approximately:

Explanation

The reported recurrence rate following excision of a primary interdigital neuroma is approximately 15%. The recurrence rate should always be communicated to the patient preoperatively.

Question 51

What is the primary function of aggrecan in the extracellular matrix of articular cartilage?

Explanation

Aggrecan is a highly sulfated proteoglycan that draws water into the cartilage matrix via Donnan osmotic pressure. This creates a swelling pressure that provides cartilage with its unique compressive stiffness.

Question 52

Which of the following bundles of the anterior cruciate ligament (ACL) is the primary restraint to anterior tibial translation when the knee is in 90 degrees of flexion?

Explanation

The anteromedial (AM) bundle of the ACL is tight in flexion and is the primary restraint to anterior translation at 90 degrees. The posterolateral (PL) bundle is tight in extension and primarily resists rotatory loads.

Question 53

A 13-year-old obese male presents with progressive left groin and knee pain. On physical examination, as his left hip is passively flexed, it obligatorily deviates into external rotation. What is the most likely diagnosis?

Explanation

Obligatory external rotation with passive hip flexion is a hallmark clinical sign of slipped capital femoral epiphysis (SCFE). The disorder is most common in overweight, adolescent males.

Question 54

In the setting of a traumatic anterior pelvic ring injury (APC-III), where is the anatomically correct placement of a circumferential pelvic binder to effectively reduce pelvic volume?

Explanation

To optimally reduce pelvic volume and stabilize the pelvic ring, a pelvic binder must be centered directly over the greater trochanters. Placement higher over the iliac crests is less effective and may worsen the deformity.

Question 55

Which of the following total hip arthroplasty (THA) bearing surface combinations demonstrates the lowest volumetric wear rate in laboratory simulator studies?

Explanation

Ceramic-on-ceramic bearing surfaces exhibit the lowest volumetric wear rates of all THA bearing options. However, they carry specific risks, such as component fracture and squeaking.

Question 56

Primary bone healing occurs without the formation of a visible fracture callus. Which of the following fixation constructs is designed to achieve primary bone healing?

Explanation

Primary bone healing requires absolute stability, which is achieved through rigid fixation with interfragmentary compression (e.g., compression plating). Constructs providing relative stability result in secondary bone healing via callus formation.

Question 57

What is the most common neurological deficit associated with a severely displaced extension-type supracondylar humerus fracture in a pediatric patient?

Explanation

The anterior interosseous nerve (AIN) is the most commonly injured nerve in extension-type supracondylar fractures. It is evaluated clinically by testing the patient's ability to make an 'OK' sign.

Question 58

The primary blood supply to the adult femoral head is derived predominantly from which of the following vessels?

Explanation

The medial femoral circumflex artery (MFCA) provides the primary blood supply to the adult femoral head via its lateral epiphyseal branches. Injury to this vessel significantly increases the risk of avascular necrosis.

Question 59

During a total knee arthroplasty (TKA), internal rotation of the femoral component relative to the epicondylar axis will most likely result in which of the following complications?

Explanation

Internal rotation of the femoral component laterally displaces the trochlear groove relative to the extensor mechanism, leading to lateral patellar maltracking and potential dislocation. It also tightens the medial compartment in flexion.

Question 60

A 25-year-old male sustains a humeral shaft fracture at the junction of the middle and distal thirds (Holstein-Lewis fracture).

Which nerve is most acutely at risk in this specific fracture pattern?

Explanation

A Holstein-Lewis fracture is a distal third spiral humerus fracture. The radial nerve is tethered at the lateral intermuscular septum in this region, making it highly susceptible to stretch or entrapment.

Question 61

Which of the following ligaments is primarily responsible for stabilizing the base of the second metatarsal to the medial cuneiform, and is critically evaluated in midfoot trauma?

Explanation

The Lisfranc ligament is a stout intra-articular, interosseous ligament connecting the lateral aspect of the medial cuneiform to the medial base of the second metatarsal. Disruption of this ligament leads to critical midfoot instability.

Question 62

In the context of flexor tendon injuries of the hand, what anatomical landmarks define 'Zone II'?

Explanation

Zone II (historically known as 'no man's land') extends from the A1 pulley (distal palmar crease) to the insertion of the FDS on the middle phalanx. Both flexor tendons travel within the narrow fibro-osseous sheath here, increasing the risk of post-repair adhesions.

Question 63

A 16-year-old male presents with knee pain. Radiographs show an aggressive, bone-forming distal femoral metaphyseal lesion with periosteal reaction (Codman's triangle). Which is the most common site of metastasis for this suspected malignancy?

Explanation

The clinical and radiographic picture strongly suggests conventional osteosarcoma. The lungs are the most common site for distant hematogenous metastasis in osteosarcoma.

Question 64

Which of the following muscles is innervated by the posterior interosseous nerve (PIN)?

Explanation

The PIN innervates the extensor carpi ulnaris (ECU), extensor digitorum communis, extensor digiti minimi, and the thumb extensors. The ECRL, brachioradialis, and anconeus are innervated by the radial nerve proper prior to its bifurcation.

Question 65

A 35-year-old construction worker falls from a height and sustains a comminuted, displaced intra-articular calcaneus fracture.

If utilizing an extensile lateral approach for ORIF, the sural nerve is most at risk in which part of the incision?

Explanation

During the extensile lateral approach to the calcaneus, the sural nerve is most commonly at risk near the distal extent of the horizontal limb of the incision. The nerve must be carefully protected to prevent painful neuromas.

Question 66

Which of the following describes the typical mechanism of injury for a Hangman's fracture (traumatic spondylolisthesis of the axis)?

Explanation

A Hangman's fracture (bilateral pars interarticularis fractures of C2) classically occurs via a mechanism of sudden hyperextension and axial loading. A common scenario is an unbelted passenger in a motor vehicle collision striking their chin against the dashboard.

Question 67

Which of the following cytokines is considered the major stimulator of osteoclast differentiation, activation, and bone resorption?

Explanation

RANKL binds to the RANK receptor on osteoclast precursors, stimulating their differentiation and survival. Osteoprotegerin (OPG) acts as a decoy receptor for RANKL, competitively inhibiting this bone-resorbing cascade.

Question 68

Perren's strain theory postulates specific mechanical environments for different types of bone healing. According to this theory, primary bone healing occurs without callus formation when the interfragmentary strain is maintained at:

Explanation

Perren's strain theory states that absolute stability with an interfragmentary strain of less than 2% is required for primary bone healing. Strains between 2% and 10% promote secondary bone healing via endochondral ossification and callus formation.

Question 69

A 25-year-old male presents with a displaced, vertically oriented femoral neck fracture (Pauwels type III). What is the most biomechanically stable fixation construct to resist the high shear forces inherent in this fracture pattern?

Explanation

Pauwels type III fractures have a vertical orientation with high shear forces that can lead to varus collapse. A sliding hip screw (fixed-angle device) combined with an anti-rotation screw provides superior biomechanical stability against vertical shear compared to multiple cancellous screws.

Question 70

A 13-year-old obese male presents with a 2-month history of groin pain and an obligatory external rotation of the thigh during passive hip flexion. Following fixation of the affected hip, which of the following is the most robust indication for prophylactic pinning of the contralateral hip?

Explanation

The patient has a Slipped Capital Femoral Epiphysis (SCFE). Prophylactic pinning of the contralateral hip is heavily considered in patients at high risk for a subsequent slip, which includes skeletal immaturity (low modified Oxford bone age score) and endocrine disorders.

Question 71

In the context of anterior cruciate ligament (ACL) reconstruction, which of the following graft choices possesses the highest initial ultimate tensile load?

Explanation

A quadrupled hamstring autograft has an ultimate tensile load of approximately 4000 N, which is significantly higher than the native ACL (approx. 2160 N) and BPTB autograft (approx. 2977 N). However, long-term clinical stability remains comparable among modern graft choices.

Question 72

When counseling a 40-year-old highly active patient regarding total hip arthroplasty (THA), which of the following bearing surface combinations should be noted as having the lowest linear and volumetric wear rates?

Explanation

Ceramic-on-ceramic articulations exhibit the lowest linear and volumetric wear rates among all THA bearing couples. Despite excellent wear characteristics, they carry unique risks such as "squeaking" and the potential for catastrophic component fracture.

Question 73

A 45-year-old male presents with bilateral lower extremity radicular pain, progressive leg weakness, and recent onset of bowel incontinence. MRI confirms a massive central L4-L5 disc herniation compressing the cauda equina. To maximize the probability of full sphincter function recovery, surgical decompression should ideally be performed within what timeframe from symptom onset?

Explanation

Cauda equina syndrome is a surgical emergency. The current literature demonstrates that surgical decompression within 48 hours of symptom onset significantly improves outcomes for bladder, bowel, and sexual function compared to decompression performed after 48 hours.

Question 74

During the surgical repair of a zone II flexor tendon laceration, preservation of the flexor sheath pulleys is critical. Which two pulleys are the most biomechanically important to prevent flexor tendon bowstringing?

Explanation

The A2 and A4 pulleys arise directly from the periosteum of the proximal and middle phalanges, respectively. They are the most critical structures to preserve or reconstruct in order to maintain the mechanical advantage of the flexor tendons and prevent bowstringing.

Question 75

A 28-year-old male presents with midfoot swelling after a fall from a horse. The AP foot radiograph demonstrates a small bony avulsion fragment in the first intermetatarsal space (the "fleck sign"). This fragment represents an avulsion of a ligament that classically originates from the:

Explanation

The "fleck sign" is pathognomonic for a Lisfranc injury, representing an avulsion fracture. The Lisfranc ligament originates from the lateral aspect of the medial cuneiform and inserts onto the medial base of the second metatarsal.

Question 76

Which of the following is the most frequent primary site of involvement for classic high-grade intramedullary osteosarcoma in the pediatric population?

Explanation

Osteosarcoma most commonly affects the metaphyses of long bones where growth is most active. The distal femur is the single most common site, followed by the proximal tibia and the proximal humerus.

Question 77

A 4-year-old child presents with hip pain and a limp. According to the original Kocher criteria used to differentiate septic arthritis from transient synovitis, which of the following is NOT one of the four classic predictive variables?

Explanation

The original four Kocher criteria are non-weight-bearing status, ESR > 40 mm/hr, temperature > 38.5 C (101.3 F), and WBC count > 12,000/mm^3. Although CRP is highly sensitive and was added to modified algorithms later, it was not one of the original four parameters.

Question 78

A 40-year-old male sustains an anteroposterior compression (APC-III) pelvic ring injury. Upon arrival, he is hypotensive and tachycardic. Despite the immediate application of a pelvic binder and administration of 2 units of packed red blood cells, he remains hemodynamically unstable. What is the most appropriate next step in management?

Explanation

In a hemodynamically unstable patient with a mechanically stabilized pelvic ring (via binder), the source of continued shock is likely retroperitoneal venous or arterial bleeding. Preperitoneal packing and angiography with embolization are the interventions of choice. CT is contraindicated in a hemodynamically unstable patient.

Question 79

A 65-year-old female presents with a dorsally displaced distal radius fracture. She is treated with open reduction and internal fixation utilizing a volar locking plate. What is the most common complication associated with this specific surgical approach and implant placement distal to the watershed line?

Explanation

Volar plating of the distal radius places the flexor tendons at risk, specifically the flexor pollicis longus (FPL). Placement of the plate prominent or distal to the watershed line significantly increases the risk of FPL rupture due to mechanical attrition.

Question 80

A 13-year-old obese male presents with left thigh pain and a limp for 3 weeks. An AP pelvis radiograph is evaluated.

On physical examination, what is the most likely finding when the affected hip is passively flexed?

Explanation

Slipped Capital Femoral Epiphysis (SCFE) classically presents with obligatory external rotation of the thigh during passive hip flexion. This occurs due to the relative posterior and inferior displacement of the proximal femoral epiphysis.

Question 81

A 55-year-old male presents with a painless, enlarging mass in the proximal humerus. Biopsy reveals a malignant cartilage-forming tumor with permeation of the host bone trabeculae. What is the most appropriate initial treatment for a conventional grade II chondrosarcoma?

Explanation

Conventional intermediate and high-grade chondrosarcomas are typically resistant to both chemotherapy and radiation. Wide surgical resection with negative margins is the standard of care to maximize survival and minimize local recurrence.

Question 82

During the process of secondary bone healing following a diaphyseal fracture, which of the following signaling molecules is most directly responsible for stimulating the differentiation of multipotent mesenchymal stem cells into osteoblasts?

Explanation

Bone morphogenetic proteins (BMPs), particularly BMP-2 and BMP-7, are potent osteoinductive growth factors. They play a critical role in the bone healing cascade by stimulating mesenchymal stem cell differentiation into osteoblastic lineages.

Question 83

A 68-year-old male presents with deteriorating handwriting, dropping objects, frequent falls, and hyperreflexia in both lower extremities. What is the most sensitive physical examination maneuver for detecting early upper motor neuron dysfunction in this patient's suspected condition?

Explanation

The Hoffmann reflex is a highly sensitive clinical sign for detecting upper motor neuron lesions and early cervical spondylotic myelopathy. Spurling test evaluates for cervical radiculopathy, not myelopathy.

Question 84

A 22-year-old soccer player undergoes an anterior cruciate ligament reconstruction using a bone-patellar tendon-bone (BTB) autograft.

Six months postoperatively, she complains of persistent anterior knee pain when descending stairs. What is the most likely cause of her pain?

Explanation

Anterior knee pain is the most frequent long-term complication following BTB autograft harvest. It is typically exacerbated by activities that eccentrically load the extensor mechanism, such as descending stairs or squatting.

Question 85

A 70-year-old female sustains a posterior dislocation of her total hip arthroplasty 4 weeks post-surgery. Her index surgical approach was posterior. To minimize the risk of recurrent posterior dislocation during a planned revision, which component position adjustment is most appropriate?

Explanation

Posterior THA instability is commonly associated with inadequate anteversion of the acetabular cup. Increasing cup anteversion and utilizing a larger diameter femoral head can effectively enhance posterior stability.

Question 86

A 35-year-old male is brought to the trauma bay after an industrial crush injury. He has an open-book pelvic ring disruption (APC-III) and remains hemodynamically unstable despite a massive transfusion protocol. What is the most appropriate next step in management?

Explanation

In a hemodynamically unstable patient with a mechanically unstable pelvic ring, temporary mechanical stabilization (binder) combined with preperitoneal pelvic packing is the most rapid and effective initial step to control the retroperitoneal venous bleeding, which is the most common hemorrhage source.

Question 87

A 24-year-old male falls on an outstretched hand and sustains a fracture of the scaphoid proximal pole.

Which of the following anatomic factors most significantly increases the risk of avascular necrosis and nonunion in this specific fracture pattern?

Explanation

The major blood supply to the scaphoid is retrograde, entering via the dorsal ridge at the waist and distal pole before perfusing the proximal pole. Proximal pole fractures disrupt this flow, resulting in a very high risk of avascular necrosis.

Question 88

A 30-year-old equestrian rider gets her foot caught in the stirrup, causing a severe hyperplantarflexion midfoot injury. Radiographs reveal pathological widening of the space between the medial and middle cuneiforms. The injured Lisfranc ligament primarily connects which two bony structures?

Explanation

The Lisfranc ligament is a robust interosseous ligament that runs obliquely from the lateral aspect of the medial cuneiform to the medial aspect of the base of the second metatarsal. It provides critical stability to the tarsometatarsal articulation.

Orthopedic Prometric Exam Preparation MCQs - Part 1

Orthopedic Prometric Exam Preparation MCQs - Part 1

Detailed Chapters & Topics

Orthopedic Prometric Exam Preparation MCQs - Part 2

Orthopedic Prometric Exam Preparation MCQs - Part 3

Orthopedic Prometric Exam Preparation MCQs - Part 4

Orthopedic Prometric Exam Preparation MCQs - Part 5

Orthopedic Prometric Exam Preparation MCQs - Part 6

Orthopedic Prometric Exam Preparation MCQs - Part 7

Orthopedic Prometric Exam Preparation MCQs - Part 8

Orthopedic Prometric Exam Preparation MCQs - Part 9

Orthopedic Prometric Exam Preparation MCQs - Part 10

Orthopedic Prometric Exam Preparation MCQs - Part 11

Orthopedic Prometric Exam Preparation MCQs - Part 12

Orthopedic Prometric Exam Preparation MCQs - Part 13

Orthopedic Prometric Exam Preparation MCQs - Part 14

Orthopedic Prometric Exam Preparation MCQs - Part 15

Orthopedic Prometric Exam Preparation MCQs - Part 16

Orthopedic Prometric Exam Preparation MCQs - Part 17

Orthopedic Prometric Exam Preparation MCQs - Part 18

Orthopedic Prometric Exam Preparation MCQs - Part 20

Orthopedic Prometric Exam Preparation MCQs - Part 19

Guide Overview