2. Trauma MCQs

DISCUSSION: Because the patient is critically ill and requires expeditious care, stabilization of the long bone fracture is required, but definitive care of the fracture should be postponed. The treatment of choice at this time is irrigation with 12 L of saline solution, followed by debridement and nondefinitive stabilization with a simple four-pin external frame to regain axial and rotational alignment. When the patient’s condition is more stable, more definitive care can be performed.

DISCUSSION: The false profile view of Lequesne and de Seze is obtained with the patient standing with the affected hip on the cassette, the ipsilateral foot parallel to the cassette, and the pelvis rotated 65 degrees from the plane of the cassette. This view best assesses anterior coverage of the femoral head.

The standard treatment for a bicondylar tibial plateau fractures is a period of post-operative non-weight bearing.Tingstad et al found favorable results of immediate weightbearing on humeral shaft fractures treated with plating and full weightbearing did not have any effect on the union or malunion rates.Brumback et al evaluated the feasibility, safety and efficacy of immediateweightbearing after treatment of femoral shaft fractures with statically locked IM nail. All the patients went on to union and no loss of fixation occurred.OrthoCash 2020

The radiograph reveals an atrophic nonunion of the diaphysis of the clavicle. Electrical or ultrasound stimulation may be an option in diaphyseal nonunions that have shown some healing response with callus formation, but these techniques are not successful in an atrophic nonunion. The preferred technique for achieving union is open reduction and internal fixation with bone graft. Percutaneous fixation has no role in treatment of nonunions of the clavicle.

DISCUSSION: In a patient with damage control orthopedics (DCO) criteria (e.g., polytrauma, coagulopathy, acidosis), the goal is to stabilize fractures with the least invasive method possible to minimize systemic inflammatory response. External fixation is the preferred method for both the open tibial fracture and the femoral fractures in this unstable patient.

The multi-axis articulated foot assembly is the best prosthetic for ambulation over uneven ground, and functions best for below knee amputations. Low functioning patients who need a prosthesis for transfers would probably benefit from a solid ankle, cushioned heel prosthesis. Runners and athletes often require high end carbon fiber prostheses. Patients with above kneeamputations have several options to optimize ambulation including solid, energy storing, and multi-axial prothesis.Aaron et al. reviews the important considerations for patient specific prostheses and new developments on the horizon to maximize ambulation in prosthesis users.Mesenchymal stem cells have the capacity to differentiate into all the following cell types EXCEPT?OsteoclastsChondrocytesAdipocytesOsteoblastsFibroblastsMesenchymal stem cells are multipotent stem cells which retain the ability to self-renew and to form cells of the mesenchymal lineage. They can therefore form muscle, fat, tendon (made from fibroblasts), bone, cartilage, and the marrow stromal cells. Mesenchymal stem cells do not however form osteoclasts, which are formed from the monocyte lineage - from hematopoietic stem cells.Caterson et al review the use of mesenchymal stem cells in tissue engineering and regeneration of musculoskeletal tissue.A 60 year-old male was brought into the operating room for total hip replacement. Before making the incision, what precautionary procedure must be performed by the entire staff to minimize surgical error?Mark the word "No" on the nonoperative extremitiesUse intraoperative fluoroscopic imagingPerform "timeout"Have blood products ready in the operating roomUse the newest prosthesisSurgical "timeout" is now part of the standard procedure which must be performed before starting surgery to minimize surgical error such as wrong site surgery.Which of the following statements regarding articular cartilage is TRUE?Cartilage is an isotropic materialMost of the water in articular cartilage exists in the deep layer next to the calcified cartilageCartilage only heals if the injury does not pass through the tidemarkCalcified cartilage is the only place that type IV collagen is foundCartilage exhibits stress shielding of the solid matrix componentsCartilage exhibits significant stress shielding of the solid matrix components due to its high water content, the non-compressibility of water, and the structural organization of collagen and proteoglycans. Cartilage is composed of a permeable porous matrix and 65 to 80% of the total weight of articular cartilage is made up of water. A pressure gradient causes the water to flow through the porous-permeable solid matrix. Significant flow of fluid through the solid matrix requires high hydrodynamic pressures because of the lowpermeability of the solid matrix.The other answers are incorrect because cartilage is anisotropic, most of the water is located in the superficial layers, it only heals if the injury does pass through the tidemark, type X collagen is found in calcified cartilage and is thought to be involved in mineralization. Type IV collagen is found in the basal lamina.A 38-year-old patient presents 6 months after intramedullary nailing of a distal third tibia fracture with symptoms consistent with complex regional pain syndrome. During the early stage of the disease he was treated with intermittent splinting, elevation and massage, contrast baths, and transcutaneous electrical nerve stimulation. Despite these modalities, he continues to have severe and debilitating symptoms. Which of the following treatment options is indicated as a second line of treatment?Long leg cast immobilization for 3 monthsWalking boot with non weight bearing for three monthsExchange nailing to stimulate healing response to the limbEpidural spinal cord stimulatorSurgical sympathectomy of the affected limbComplex regional pain syndrome is a chronic progressive disease of unknown etiology characterized by pain, swelling and skin changes. If nonoperative modalities fail, a surgical sympathectomy of the affected limb is indicated.The first line of treatment is physical therapy including intermittent splinting, elevation and massage, contrast baths, and transcutaneous electrical nerve stimulation. Aggressive passive range-of-motion exercises should be avoided. If nonoperative modalites fail and symptoms remain severe, a surgical sympathectomy of the affected limb is indicated.Keys to successful treatment include early clinical suspicion and treatment. Late CRPS is highly refractory to treatment and often results in permanent disability.Two forms of Complex regional pain syndrome exist: 1) Reflex sympathetic dystrophy- which does not demonstrate nerve lesions, and 2) Causalgia - which is associated with damage to peripheral nerves. Diagnostic criteria include:Major criteria: intense and prolonged pain, swelling, stiffness, and discoloration (vasomotor disturbances).Minor criteria: trophic changes, osseous demineralization, temperature changes, and palmar fibromatosis.Tran et al present their systemic review of 41 RCTs of the research regarding treatment of CRPS. Their data suggest that only bisphosphonates offer clear medicinal benefits in the treatment of CRPS. Evidence regarding a beneficial effect of lumbar sympathetic blocks, gabapentin, and physical therapy is lacking. As such, these authors advocate for further study thru well-designed RCTs to better evaluate appropriate and effective treatment strategies.You are planning an intramedullary nail to treat a geriatric patient with a peritrochanteric femur fracture. Which of the following preoperative considerations is correct regarding your implant?The radius of curvature of an intramedullary nail is generally greater than the radius of curvature of the femurClosed section nails have less stiffness than slotted nailsThe medial/lateral nail starting point relative to the greater trochanter does not affect varus/valgus position in the fractureThe bending stiffness of your nail is proportional to the second power of the radiusIntramedullary nails allow for mostly direct intramembranous bone healingThe radius of curvature of an intramedullary nail is generally greater than the radius of curvature of the femur, which is why anterior distal femurpenetration is a known complication of intramedullary nailing procedures.Egol et al. evaluated the radius of curvature of 948 femurs (474 matched pairs) and compared those data with current intramedullary nails. He found the average femoral anterior radius of curvature was 120 cm (± 36 cm)whereas the radius of curvature of the intramedullary nails ranged from 186 to 300 cm.The other answers are incorrect because closed section nails have more stiffness than slotted nails. The starting position on the greater trochanter greatly affects the post- operative varus/valgus of the fracture. Intramedullary nails allow for mostly indirect enchondral bone healing due to relative motion at the fracture site.All of the following antibiotics function by interfering with protein synthesis by inhibiting ribosomes EXCEPTgentamicintobramycinvancomycinerythromycinlinezolidGentamicin and tobramycin are aminoglycosides that function by inhibition of bacterial protein synthesis via irreversible binding to ribosomal subunits. Erythromycin functions by binding to the 50s subunit of the bacterial 70s rRNA complex and thereby inhibits protein synthesis. Linezolid binds to the 23s portion of the ribosomal subunit and inhibits protein synthesis. In contrast, Vancomycin acts by inhibiting proper cell wall synthesis and does not inhibit the ribosome.The bending rigidity of the implant shown in Figure A is proportional to what power of the measured radius of the implant?

DISCUSSION: Nonunions after intramedullary nails are often treated with exchange reamed nailing. In a recent study, this resulted in a union rate of 53%. After failed exchange nailing, bone grafting and compression plating should be used. The other options resulted in less satisfactory results as compared to bone grafting and compression plating.

The child has isolated ipsilateral femoral shaft and tibial shaft fractures. Spica cast immobilization is unlikely to accommodate for shortening and alignment in this child with multiple levels of injury. In this instance, efforts should be made to mobilize a least one level of the limb; therefore, treatment should include flexible nailing of the femur and tibia. Rigid reamed nails are not indicated in this young patient secondary to risk of a growth arrest and osteonecrosis of the proximal femur.

Anterior tibial pain can often be difficult to diagnose. A bone scan showing the tibial cortex in a diffuse, longitudinal orientation is consistent with shin splints compared to a more discreet, localized uptake more commonly seen with a stress fracture. Bone stress injuries are due to cyclical overuse of the bone. They are relatively common in athletes and military recruits but are also seem in otherwise healthy people who have recently started new or intensive physical activity. Diagnosis of bone stress injuries is based on the patient's history of increased physical activity and on imaging findings.The general symptom of a bone stress injury is stress-related pain. Bone stress injuries are difficult to diagnose based only on a clinical examination because the clinical symptoms may vary depending on the phase of the pathophysiological spectrum in the bone stress injury. Imaging studies are needed to ensure an early and exact diagnosis. If the diagnosis is made early, most bone stress injuries heal well without complications.

In bridged plating, only the most proximal and distal screw holes are filled. This creates a flexible, axially stable construct. The construct is flexible because of increased distance between the two screws closest to the fracture (long working length), allowing for stress distribution and permitting more motion at the fracture site. The construct is also axially stable because the plate acts as an extramedullary splint and resists axial compression.

Facet joint fracture or dislocation is associated with an increased risk of loss of alignment with halo vest immobilization. The recently published study by van Middendorp and associates confirms the findings of prior studies that facet fracture-subluxations or dislocations are difficult to immobilize with a halo vest due to a limited ability to maintain reduction and alignment. C2 pars fractures, burst fractures, and C1 lateral mass fractures can be managed with halo vest immobilization.

DISCUSSION: The radiograph shows a type V acromioclavicular joint injury. Type V injuries involve disruption of the acromioclavicular and coracoclavicular ligaments. Type I injuries involve a sprain of the acromioclavicular joint ligaments. Type II injuries involve disruption of the acromioclavicular joint ligaments; the coracoclavicular ligaments are partially injured. Sternoclavicular ligaments stabilize the medial clavicle and the sternum; they are not damaged with acromioclavicular joint dislocations. REFERENCES: Fukuda K, Craig EV, An KN, et al: Biomechanical study of the ligamentous system of the acromioclavicular joint. J Bone Joint Surg Am 1986;68:434-439. Bosworth B: Complete acromioclavicular dislocation. N Engl J Med 1949;241:221-225.

DISCUSSION: Transolecranon fracture-dislocations are most effectively managed with open reduction and internal fixation, followed by early aggressive range of motion. Concomitant injury to the collateral ligament is rare, and stability is achieved by anatomic reconstruction of the olecranon fracture with rigid fixation. The need for collateral ligament repair or a hinged external fixator is uncommon in this fracture pattern. REFERENCE: Ring D, Jupiter JB, Sanders RW, et al: Transolecranon fracture-dislocation of the elbow. J Orthop Trauma 1997;11:545-550.

DISCUSSION: Due to the relatively high incidence of delayed union and nonunion associated with this mildly displaced Jones-type fracture, and the temporal proximity to his playing season, intramedullary screw fixation is the treatment of choice in this collegiate athlete to best ensure healing and expedite his return to football. If nonsurgical management were elected, application of a non-weight-bearing short leg cast would be appropriate since a higher likelihood of healing is expected with it versus a short leg walking cast. The risk of recurrent fracture of fractures that heal with nonsurgical management has reportedly been high (approximately 30%). REFERENCES: Quill GE: Fractures of the proximal fifth metatarsal. Orthop Clin North Am 1995;26:353-361. Torg JS, Balduini FC, Zelko RR, et al: Fractures of the base of the fifth metatarsal distal to the tuberosity: Classification and guidelines for nonsurgical and surgical management. J Bone Joint Surg Am 1984;66:209-214. Dameron TB Jr: Fractures of the proximal fifth metatarsal: Selecting the best treatment option. J Am Acad Orthop Surg 1995;3:110-114.

Whereas ipsilateral fractures of the femoral neck and shaft are uncommon, it is critical to recognize a femoral neck fracture that may occur in conjunction with a femoral shaft fracture. The combined injury is seen in 2% to 9% of femoral shaft fractures and may initially be missed in as many as one third of the cases. Preoperative examination of a thin cut CT scan and dedicated AP internal rotation views of the femoral neck can help identify this injury. In addition, the intraoperative AP and lateral hip fluoroscopic view should be examined, and a dedicated radiograph of the hip obtained at the conclusion of the surgery. At follow-up, Tornetta and associates has recommendedobtaining a dedicated AP radiograph of the hip with the leg internally rotated 15 to 20 degrees. Because the femoral neck is anteverted, 15 to 20 degrees of internal rotation of the hip offers the best view of the femoral neck. Whereas associated lumbar spine pathology may cause groin pain, the presence of a missed femoral neck fracture must first be ruled out prior to investigating other sources of pain.

OrthoCash 2020

DISCUSSION: When a displaced talar neck fracture occurs, the rate of osteonecrosis is high; however, many revascularize the talus without collapse. A nonunion can occur but is less common than osteonecrosis and arthritis. A varus malunion can be debilitating and lead to subtalar arthritis. In a fracture with the talar body dislocated posteromedially, neurologic deficits in the tibial nerve distribution are common but typically improve with urgent reduction. Studies show that posttraumatic subtalar arthritis is common after this injury and is the most likely cause of long-term functional impairment.

DISCUSSION: Rapid fluid resuscitation is the cornerstone of therapy for hypovolemic shock. Fluid should be infused at a rate sufficient to rapidly correct the deficit. In general, a favorable response to fluid replacement therapy includes increased urinary output (at least 0.5 mL/kg/hr), improved level of consciousness, increased peripheral perfusion, and changes in vital signs. Lab values that are important include lactic acid, which is increased if the shock is severe enough to cause anaerobic metabolism, and decreased serum bicarbonate which leads to a negative base deficit. Successful resuscitation in a shock patient will therefore lead to a falling lactate (i.e., <2.0 mmol/L) and a normalizing pH.

DISCUSSION: The radiographs reveal a Monteggia injury, with a proximal ulnar shaft fracture and a radial head dislocation. Treatment involves open reduction and internal fixation of the ulnar fracture. With correct reduction of the ulna, the radial head is reducible and remains stable, despite an obvious soft-tissue injury around the elbow. Problems with persistent radial head subluxation are almost always attributed to malreduction of the ulnar fracture. Rare causes of persistent radial head subluxation are interposition of soft tissues in the joint and lateral ligamentous injuries.

DISCUSSION: Treatment of a chronic nonunion of the proximal humerus in the elderly should be treated with arthroplasty when possible. Critical attention should be paid to correct all deformities: tuberosity positioning, articular surface realignment, soft tissue balancing, rotator cuff repair (when needed), and treatment of soft tissue contractures. Attempts at internal fixation should be performed with caution in this patient population, due to general osteopenia and significant rates of loss of fracture reduction. The referenced article by Cheung et al reviews treatment options for proximal humeral nonunions and reports successful use of arthroplasty in treating elderly osteoporotic proximal humeral nonunions as a pain-relieving procedure.