Surgical Principles Flashcards

Question

Neutralization plates

Answer 1

Neutralization plates are commonly used in comminuted fractures. The plate is attached to two primary fracture fragments. Force is then transmitted from proximal to distal, passing over the fracture site neutralizing torsional forces. Bridge plates provide stability to allow for callus formation. The plate is fixed only to two fracture fragments leaving the fracture zone untouched maximizing the blood supply to the area.

Answer 2

Damage to the lateral plantar nerve is a risk present during intramedullary nailing/TCC fusion. The cadaveric study performed on 10 cadaveric legs listed below showed: “The lateral plantar artery was found to be in direct contact with the nail 70% of the time, with a macroscopic laceration 30% of the time. The Baxter nerve was injured 20% of the time, as was the lateral plantar nerve. The medial plantar artery and nerve were never injured. The most proximal structure to cross line AB was the Baxter nerve followed by the lateral plantar artery, the nail, the lateral plantar nerve, and the medial plantar nerve.

Answer 3

Sliding the calcaneus anteriorly on the talus results in dorsiflexion of the forefoot on the rearfoot (decreasing arch height) Conversely, sliding the calcaneus posteriorly on the talus results in plantarflexion of the forefoot on the rearfoot (increasing arch height).

Answer 4

The Chaput fragment is the anterolateral fragment of the distal tibia (the anterior inferior tib fib ligament stays attached to the fracture fragment. A pilon fracture is often splint into 3 fragments: 1. Chaput (anterolateral) 2. Volkmann (posterolateral) 3. Medial fragment. The Wagstaff fragment is the fibular equivalent to the Chaput fragment. Wagstaff fragment serves as the other attachment point of the anterior inferior tibiofibular ligament.

Answer 5

(A) Type I fracture is a talar neck fracture, (B) Type II is a talar neck fracture with subtalar dislocation, (C) Type III is a talar neck fracture with subtalar and tibiotalar dislocations, and (D) Type IV is a talar neck fracture with subtalar, tibiotalar, and talonavicular dislocations.

Answer 6

The dorsomedial approach to the navicular is made between the tibialis anterior tendon and extensor hallucis longus (EHL) tendon. The approach should be made straight down from skin to periosteum without raising flaps or any unnecessary dissection

Answer 7

Meniscoid lesions and fibrous bands are unique lesions, most likely of differing origin. Although they are similar in clinical presentation, their appearance at arthroscopy is clearly different. The meniscoid lesion is attached only at its origin at the inferolateral gutter on the anterior talofibular ligament. Fibrous bands are attached at two ends and may be found anywhere in the joint but are most common extending dramatically over the anterior joint line. Unexpected encountering of a fibrous band should alert the surgeon to carefully inspect the joint for other associated (occult) pathology. Because of the frequent association of bands with antecedent fracture, the observation of this lesion should lead the clinician to consider antecedent intra-articular fracture (transchondral fracture, malleolar fracture, and tibial pilon fracture) as a likely co-pathology. Careful examination of the ankle and review of the radiographs and other available images may be helpful in assessing the joint for these injuries when fibrous bands are encountered. The association of meniscoid lesion with prior soft tissue injury (sprain) is also important to understanding this lesion. Excision of both these abnormal lesions in concert with repair of coexistent pathology is associated with improvement of symptoms. Finally, both fibrous bands and meniscoid lesions are associated with symptoms that warrant closer inspection and observation. Whether the operative intervention is open or closed, the reader can benefit from the information presented.

Answer 8

Choparts amputation is a partial foot amputation through the talonavicular and calcaneocuboid joints and its primary complication is equinus deformity . This can be mitigated by lengthening of the Achilles tendon and transfer of the tibialis anterior to the talar neck.

Answer 9

The presence of tibial torsion can be suspected from lateral position of the patella causing patella maltracking and patellofemoral joint pain.” “Normally, lateral rotation of the tibia increases from approximately 5º at birth to approximately 15º at maturity. Whereas medial torsion improves with time, lateral torsion often worsens because the natural progression is toward increasing external torsion. The ability to compensate for tibial torsion depends on the amount of inversion and eversion present in the foot and on the amount of rotation possible at the hip. Internal torsion causes the foot to adduct, and the patient tries to compensate by everting the foot, externally rotating at the hip, or both. Similarly, persons with external tibial torsion invert at the foot and internally rotate at the hips.

Answer 10

evere osteoporosis, history of osteomyelitis, diffuse osteonecrosis, or significant bone defect on the tibial and/or talar site. Previous long-term therapy with steroids or immunosuppressive substances may also reduce bone quality, resulting in compromised osteo integration of prosthesis components. Further relative contraindications for TAR include heavy physical work, medium level of sports activities (eg, tennis, jogging, and downhill ski), high body mass index, diabetes, and smoking. Significant preoperative varus or valgus deformity (>10°) has also been seen as a contraindication for TAR

Answer 11

Latency period is subjective and typically ranges from 4-14 days for foot and ankle procedures. If performed within metaphyseal bone, distraction can begin in 7-10 days, whereas a latency of 2 weeks is suggested for the procedure in diaphyseal bone. It should be noted that there is no consensus on this topic. Considerations should be made for bone mineralization, overall health, osteopenia, osteoporosis, diabetes, weight, etc. In generally a longer latency period is considered in adults as younger individuals have a thicker periosteum and quicker revascularization that allows for earlier callus distraction. BoardWizards note: There is controversy regarding this topic. Review of this topic has been recommended by several of our writers. We strongly recommend referencing McGlamry’s textbook because, in our opinion; questions regarding latency (and most controversial subjects) will most likely be sourced from there.

Answer 12

Ideal position of the 1st MTP joint after arthrodesis should be 10 - 15 degrees of dorsiflexion and 10 - 20 degrees of valgus. In the operating room, the hallux should sit loaded just slightly off of a flat plate, and position parallel to the 2nd toe.

Answer 13

During a jones tenosuspension, the extensor hallucis longus tendon is transected and then rerouted through a medial to lateral drill hole in the 1st met head and then sutured back to itself dorsally. This procedure is recommended for the following circumstances: flexible cavus foot, flexible plantarflexed first ray, cock-up hallux, prophylaxis when both hallucal sesamoid bones are removed, and to relieve lesser metatarslgia.

Answer 14

Equinus. As part of the Ponseti technique, a percutaneous tendo-Achilles tenotomy (TAT) is performed on feet that are unable to obtain 15° of dorsiflexion once the forefoot adduction and hindfoot varus have been corrected. It has been reported that TAT is required in approximately 80% of cases

Answer 15

The appropriate size countersink for a fully threaded 6.5 mm and a partially threaded 6.5 mm screw is 6.5mm. Synthes large frag.

Answer 16

Venous congestion is a well-known complication of the RSSAF because of the presence of valves in the deep venous system that prevent uninterrupted retrograde venous flow. The true incidence of congestion is difficult to interpret from the literature as most data are derived from small case series and not every reconstructive surgeon performs the same technique. Proposed explanations for the wide variation in outcomes include differences in patient comorbidities, pedicle widths, whether the pedicle is tunneled or exteriorized, or if the flap is supercharged”

Answer 17

Relocate sesamoids

Answer 18

Farm injuries are considered inherently dirty/contaminated wounds, and therefore are automatically considered Type III Gustilo Anderson wounds, regardless of their size. The recommended antibiotics for Type III Gustilo Anderson injuries include a first or second-generation cephalosporin with an aminoglycoside or fluoroquinolone within 3 hours of injury, with penicillin added for farm injuries.

Answer 19

The mechanism of injury involves a dorsiflexed foot and sudden, substantial inversion contraction of the peroneal muscles.

Answer 20

A surgical shoe will limit the ability of the hallux to “toe-off” and activate the windlass mechanism; inhibiting the propulsive phase of gait.

Answer 21

The Weil osteotomy is made in an orientation from dorsal distal to plantar proximal, angulated 30 degrees, parallel to the weightbearing surface of the 2nd metatarsal.

Answer 22

Lisfranc joint injuries occur from 2 basic mechanisms: 1. Direct force injuries occur with a crushing mechanism (ie, crushe by vehicle, weight, large object). 2. Indirect injuries are most common and occur from forefoot abduction and plantarflexion forces to the TMT joint.

Answer 23

The initial incision which will become the diagonal line of the Z, is made longitudinally along the length of the scar or along the direction to be lengthened. The other two incisions are then made off this central line at 45-60 degree angles and should parallel to the RSTL

Answer 24

During range of motion exercises a hallux that drifts laterally after being placed in neutral position is track-bound, unable to stay completely in a corrected position. Hallux that drifts immediately back to abnormal position during motion is tracking.

Answer 25

The tendon utilized for the tendon transfer is the Flexor Hallucis Longus tendon, which can be utilized in repair of the achilles. It is innervated by the tibial nerve and inserts into the distal phalanx of the first digit/hallux. A possible outcome of sacrificing the Flexor Hallucis Longus for a tendon transfer is weakness with plantarflexion of the hallux.

Answer 26

Larger IM correction is a significant advantage in using first metatarsal base osteotomies and procedures. Simple fixation, early-weight bearing, and less shortening are often associated with distal 1st metatarsal osteotomies.

Answer 27

The True, calculated intermetatarsal angle = the intermetatarsal angle plus (metatarsus adductus angle – 15 degrees). In this example 12 + (20 – 15) = 17 degrees. Just remember than metadductus angle over 15 is abnormal, therefore only include any deformity over normal in your calculation

Answer 28

Clostridium is an anaerobe, and would be covered by Penicillin as this is a dirty, contaminated injury.

Answer 29

- Flexor stabilization - Flexor substitution - Extensor substitution

Answer 30

Flexor stabilization: most common, occur in a pronated foot and involves the flexors tendons that overpower the interossei. Recognized by excessive “gripping,” hammering/clawing, and adductovarus deformity to the fourth and fifth toes

Answer 31

Flexor substitution, the least common of the three groupings responsible for digital deformity. The deep compartment flexors overpower the interossei when they attempt to substitute for a weak triceps surae muscle. This may be seen after excessive lengthening of the Achilles tendon.

Answer 32

Extensor substitution: occurs when the extensors overpower the lumbricals, often seen in anterior cavus, anterior compartment muscle weakness, and equinus. Clinically this type is recognizable by as the extensor tendons begin to contract prior to heel off with marked bowstringing. The toes appear clawed with no varus rotation.

Answer 33

Serial casting should be the initial treatment, though before the article by Dobbs et al, it was usually thought to be unsuccessful. Serial casting should be used to stretch the foot in plantarflexion and inversion while counterpressure is applied to the medial aspect of the talus. Elongating and stretching the talonavicular joint in order to facilitate its reduction is important in avoiding compression of the dorsally displaced navicular into the talus. A long leg cast is then applied, with the knee flexed 90° to prevent the cast from slipping. The cast should be changed frequently (about every 1-2 weeks) in order to maximize its effectiveness. Whereas preoperative casting may be useful for stretching out the dorsal structures, casting rarely is associated with permanent correction.” “In the Dobbs technique, if the navicular can be manipulated into the correct alignment relative to the talus, it can then be pinned with a Kirschner wire (K-wire) to maintain the reduction. A small incision can be made over the talonavicular joint, and the joint can be reduced via an open technique if there is any difficulty with the reduction. A percutaneous heel-cord tenotomy is always performed. The K-wire is left in place for a total of 5 weeks, and the position is held with a long leg cast, which is changed 2 weeks after surgery. A postoperative brace is worn 23 hours per day until walking age, and it is then worn for walking until age 2 years. A single-stage surgical correction is another option and can be accomplished via either the Cincinnati approach or the dorsal approach

Answer 34

Stage 1 Stage 2 A/B Stage 3 Stage 4

Answer 35

Normal radiographs, able to perform single-heel raise, and mild tenosynovitis.

Answer 36

Arch collapse on a radiograph, unable to perform single-heel raise, and a flexible flatfoot deformity.

Answer 37

Arch collapse and talonavicular uncoverage (over 40%) on a radiograph, unable to perform single heel raise, flexible flatfoot deformity, and characteristic forefoot abduction or “too many toes” sign.

Answer 38

Subtalar arthritis on a radiograph, unable to perform single heel raise, flatfoot deformity with rigid forefoot abduction and hind foot valgus

Answer 39

Valgus deformity of talus in the ankle mortise visualized on AP radiograph of the ankle - talar tilt due to deltoid ligament compromise, subtalar arthritis on radiographs, unable to perform single heel raise, flatfoot deformity with rigid forefoot abduction and hind foot valgus.

Answer 40

There is evidence to demonstrate that 83% of patients with plantar fasciitis have an equinus contracture.

Answer 41

Anterior translation of the talus will increase the lever arm of the foot and place extra mechanical stress across the midtarsal joint complex, leading to premature wear over time.

Answer 42

Buttress plates function opposite to tension band. The plate is always under compression and is helpful around thin bone and around joints, and are used to support bone that is unstable in axial loading.

Answer 43

Antiglide plates are a method of fixation functioning similar to a buttress plate but produces compression when a lag screw passes through the plate. This is often seen in distal 1/3 fibular fractures where a 1/3 tubular plate is applied posterolaterally on the fibula to act as a buttress to resist posterior-proximal displacement with an additional lag screw applied through the plate.

Answer 44

Neutralization plates are commonly used in comminuted fractures, and often used in combination with lag screws.

Answer 45

Bridge plating is fixed to only the two fracture fragments, leaving the fracture zone untouched; maximizing the blood supply to the area.

Answer 46

Post-traumatic arthritis typically will take hold after an intra articular fracture. Chondrocytes which are affected can die via necrosis or apoptosis. Initial cell death at the superficial cartilage zones will occur via necrosis at the fracture margins, while apoptosis will occur in a delayed manner.

Answer 47

Patients between 12 and 15 years of age with closing physes are susceptible to specific distal tibial fracture patterns. The Tillaux fracture is a variant of SH-III fractures and represents avulsion of anterolateral distal tibia epiphysis at the insertion site of anterior inferior tibiofibular ligament. This accounts for less than 5% of pediatric ankle fractures, and may present together with a distal fibula fracture. Triplane fractures are complex, three-dimensional SH-IV fractures, occurring in younger children than the Tillaux fractures

Answer 48

``` A surgical pen is used to mark the Achilles tendon and the lateral malleolus. With the foot in neutral position (90°), a straight line parallel to the foot sole is drawn from the tip of the lateral malleolus to the Achilles tendon. The posterolateral portal (PL) is made just proximal to this line and tangential to the Achilles tendon. The posteromedial (PM) portal is located at the same level on the medial side of the Achilles tendon . Ten ml of saline are injected into the ankle or subtalar joint with a syringe. Then, the vertical skin incision of the PL portal is made. Dissection of the subcutaneous tissue and deeper layers is performed bluntly with a mosquito clamp, which is oriented towards the first interdigital space. A 2.7 or 4.0-mm arthroscope is then inserted into the joint. The posterior talar process can be palpated and used as a landmark between ankle and subtalar joints. The PM portal skin incision is then made at the same level and parallel with respect to the PL portal. Deep dissection is performed with a mosquito clamp as previously described. The clamp is directed toward the arthroscope shaft at a 90° angle, then it is moved along the shaft and opened in front of the tip of the arthroscope in order to create space and improve visualization. A 2.9 full-radius mm shaver is then inserted into the PM portal, and initial synovectomy is performed. The FHL tendon is an important landmark and should always be identified, debrided from its sheath, and kept in view medially in order to avoid damage to the neurovascular bundle during the whole procedure. Passive motion of the great toe will assist in the identification of the FHL ```

Answer 49

Lateral process fractures are usually a consequence of forced dorsiflexion and inversion of fixed pronated foot. These are also commonly known as snowboarder’s fractures.” “Fractures of the posterolateral process can potentially be mistaken as os trigonum, which is the posterior process arising from a secondary ossification that failed to fuse with the body of the talus. An os trigonum appears rounded, corticated and is found in 7% to 10% of the normal population. It can also fracture and cause difficulty in diagnosis, but a CT or MRI scan can aid in differentiating the two conditions. Fractures of the lateral tubercle of the posterior process are known as Shepherd’s fracture and may be similar to ankle sprains in presentation but may demonstrate posterolateral tenderness with pain both on movement of the subtalar joint and on passive movement of the flexor hallucis longus (FHL) tendon.

Answer 50

External rotation Pathologic forces to the ankle syndesmosis typically result from excessive external rotation of the ankle at the end-range of dorsiflexion or some combination of ankle dorsiflexion associated with adduction or abduction of the foot. These forces can produce widening of the fibula relative to the tibia at the ankle mortise, disrupting the syndesmotic ligaments and resulting in secondary talar instability . With high pathologic forces rotating a fixed foot (i.e., from body weight or impact with another player or object), the talus rotates laterally, resulting in injury to the AITFL. With continued force, the fibula moves further away from the tibia, producing a shearing force that can be transferred axially between the bones, causing injury to the interosseous membrane. With continued high forces, the PITFL and deltoid can fail, and/or the fibula, posterior malleolus, or medial malleolus can fracture

Answer 51

Open reduction and internal fixation is currently the accepted treatment for displaced Lisfranc joint injuries. However, even with anatomic reduction and stable internal fixation, treatment of these injuries does not have uniformly excellent outcomes. A primary stable arthrodesis of the medial two or three rays appears to have a better short and medium- term outcome than open reduction and internal fixation of ligamentous Lisfranc joint injuries

Answer 52

6 to 7 mm from the tibial nerve & 3 to 4 mm from the sural nerve

Answer 53

The posterior tibial tendon (PTT) can be subjected to anterior transfer, a surgical procedure performed to repair foot drop caused by several conditions, such as irreversible lesions in the peroneal nerve or the dorsiflexor muscles of the foot and the ankle , supinated equinovarus foot deformity secondary to club deformity , Charcot-Marie-Tooth disease , leprosy , mononeuropathy, trauma to the common peroneal nerve ,cerebrovascular accident, and Duchenne’s muscular dystrophy

Answer 54

The best age for this procedure is one to two years, and the upper age limit should be approximately six years

Answer 55

In previous studies, most authors agree that the distal fibula plays the key role in the stability of the ankles because 1 mm lateral displacement of the talus decreases the tibiotalar contact surface by 42%. As we know, ankle instability increases the risk of tibiotalar arthrosis. . .We concluded that rigid fixation of the fractured fibula in the pilon fracture provided strong ankle stability and should decrease the ankle arthrosis

Answer 56

Deep infection is a potential complication of any joint implant. Ankle arthroplasty is no exception. The American Academy of Orthopaedic Surgeons has a position statement on the use of prophylactic antibiotics after joint arthroplasty. The authors follow the same recommendations. All patients undergoing dental, genitourinary, or gastrointestinal manipulations who are within 2 years of their arthroplasty surgery are given 2 g amoxicillin 2 hours before the procedure, or 600 mg clindamycin 1 hour before, if allergic to penicillin. After 2 years, only patients at high-risk (patients with diabetes, patients with hemophilia, or patients who are immunosuppressed) are given prophylaxis antibiotics. The authors also consider patients with rheumatoid arthritis who are taking medication for their disease to be in this high-risk category