Complications Flashcards
AVN following chevron osteotomy
The artery most likely implicated in development of AVN of the first metatarsal head is the first dorsal metatarsal artery, which is fed by the nutrient artery. This is most likely to cause AVN if disrupted. The first dorsal metatarsal artery helps to form a significant extracapsular anastomosis that supplies approximately two-thirds of the metatarsal head.
Contraction over time of skin grafts
The thinner the graft is, the more likely it is to contract. STSG will contract more than FTSG.
Hyperplasia following 1st MTPJ implant
Traditionally, long term results in 1st MTP joint total implants have varied. Instability and synovitis are common complications with the Swanson implant. Fibrous hyperplasia is common and forms within medullary bone, impacting the hinges and increases likelihood for failure and need for removal. Insertion of the implant sizer allows for assessment of the fit, and directs appropriate bone resection and implant placement alignment.
Intravascular lidocaine
Peak blood levels of lidocaine usually occur 10–25 minutes after injection. This is the point at which the toxic effects are most likely to be observed. The onset of symptoms is faster if accidental intravascular injection has occurred. The first symptoms and signs of local anaesthetic toxicity are usually neurological with numbness of the mouth and tongue. Shortly afterwards, there is the onset of tinnitus, confusion, seizures, and potentially coma.
Toxic dose for lidocaine plain
Toxic dose for Lidocaine plain = 4.5mg/kg
Toxic dose for lidocaine with epi
Lidocaine with epinephrine = 7mg/kg
Toxic dose for marcaine plain
Marcaine plain = 3mg/kg
Toxic dose of lidocaine plain for a 60 kg female
60kg x 4.5mg = 270mg. 270mg % (10mg/mL) = 27mL
Most common complication of external fixation
Pin-tract infections are the most common complication, and an almost inevitable problem when using external fixation. If left untreated the infection may lead to pin loosening and instability of pin-bone construct.
Most common complication following displaced talar neck fracture
Subtalar joint arthritis would be the single most likely complication in an isolated subtalar joint dislocation. “Peritalar stiffness and arthritis commonly occur after both talar neck and talar body fractures. Subtalar joint arthritis occurs more frequently after talar neck fractures, with an incidence of 60–100%. Talar body fractures have increased rates of arthritis at the tibiotalar joint. Despite x-ray evidence of joint space narrowing in many patients, there is usually little need for secondary reconstructive procedures
What does a distraction bone block arthrodesis achieve
TN subluxation, TT impingement, subtalar arthrosis
Does not address peroneal tendons directly
Subtalar joint arthritis would be the single most likely complication in an isolated subtalar joint dislocation. “Peritalar stiffness and arthritis commonly occur after both talar neck and talar body fractures. Subtalar joint arthritis occurs more frequently after talar neck fractures, with an incidence of 60–100%. Talar body fractures have increased rates of arthritis at the tibiotalar joint. Despite x-ray evidence of joint space narrowing in many patients, there is usually little need for secondary reconstructive procedures
What does a distraction bone block arthrodesis achieve
TN subluxation, TT impingement, subtalar arthrosis
Does not address peroneal tendons directly
Subtalar joint arthritis would be the single most likely complication in an isolated subtalar joint dislocation. “Peritalar stiffness and arthritis commonly occur after both talar neck and talar body fractures. Subtalar joint arthritis occurs more frequently after talar neck fractures, with an incidence of 60–100%. Talar body fractures have increased rates of arthritis at the tibiotalar joint. Despite x-ray evidence of joint space narrowing in many patients, there is usually little need for secondary reconstructive procedures
Peroneal tendons following DIACF
Peroneal tendonitis is typically seen following non surgical management of displaced calcaneal fractures. The articular surface is not reduced and the heel remains shortened and widened, with the talus being dorsiflexed. The lateral wall, being displaced, leads to peroneal impingement/irritation.
Talar neck fracture blood supply
The image shown is a type 3 Hawkins fracture. The deltoid branch of the posterior tibial artery; supplies up to 1/2 of the medial aspect of the talar body. Often, it is the deltoid artery that is the only remaining blood supply to the talus in these injuries. It is vitally important to preserve the deltoid ligament in order to avoid avascular necrosis.
Risk of AVN following talar neck fracture
The extent of initial fracture displacement/dislocation, is related to the incidence of avascular necrosis of the talus. The greater the fracture displacement, the higher the probability the blood supply to the talus has been compromised; which then will increase the likelihood of avascular necrosis developing.
Rates of nonunion for the 3 joints in a triple arthrodesis
The overall nonunion rate for triple arthrodesis in this series was 29.9% (47/157). The nonunion rate of the talonavicular joint was 20.4% (32/157); the nonunion rate of the calcaneocuboid joint was 17.2% (27/157); and the nonunion rate of the subtalar joint was 8.9% (14/157)
Structure at risk during gastroc recession
The sural nerve should always be protected during a gastrocnemius recession. “It is generally safe to place the posterolateral incision more than 14cm above the calcaneal tuberosity to avoid the sural nerve if surgeons plan to use a posterolateral incision for endoscopic recession
Gustilo Anderson Classification
Type I: simple fracture patterns with wounds less than 1 cm
Type II: simple fracture pattern or mildly comminuted with wound 1-10 cm
Type IIIA: significant soft tissue injury that requires skin graft
Type IIIB: significant soft tissue injury that requires flap coverage
Type IIIC: significant soft tissue injury with arterial compromise requiring vascular repair
Increased risk of nonunion in talar neck fracture
The deltoid artery located within the deep deltoid provides blood supply to the deltoid ligament. Care should be taken to preserve the deep deltoid as often this may be the only remaining blood supply to the body with a talar neck fracture.
Contraction of skin grafts
The thinner the graft is, the more likely it is to contract. STSG will contract more than FTSG.
Hawkins classification
Hawkins I: Nondisplaced 0-13% chance of AVN
Hawkins II: Subtalar dislocation 20-50% chance of AVN
Hawkins III: Subtalar and tibiotalar dislocation 20-100% chance of AVN
Hawkins IV: Subtalar, tibiotalar, and talonavicular dislocation 70-100% chance of AVN
Osseous equinus following ankle arthrodesis
During an ankle fusion, the ankle must be positioned at 90 degrees. Often times, the surgeon will misinterpret mid foot extension as a form of ankle dorsiflexion, and this may lead to improper ankle fixation at time of hardware placement. Surgeons should have fluoroscopic evaluation during positioning and fixation.
Hammer toes
Flexor stabilization. This is the most common cause of hammertoes, occurring in a pronated foot type when the flexor digitorum longus or flexor digitorum brevis gains a mechanical advantage over the interossei muscles. Due to the decreased action of the interossei, the flexors contract earlier and longer in an effort to stabilize the toe.
Flexor substitution. Least common cause where the flexors gain an advantage over the interossei. This usually occurs when the achilles tendon is weak and the other flexors compensate by contracting earlier and longer.
Extensor substitution. This occurs in the swing phase of gait rather than the stance phase like the other two scenarios. The EDL gains an advantage over the lumbricales.
In the scenario described in the MCQ, the FDL has become mechanically weak, thereby allowing for the EDL to gain mechanical advantage over the lumbricales leading to extensor substitution and a cock up hallux.
AVN following chevron osteotomy
The artery most likely implicated in development of AVN of the first metatarsal head is the first dorsal metatarsal artery, which is fed by the nutrient artery. This is most likely to cause AVN if disrupted. The first dorsal metatarsal artery helps to form a significant extracapsular anastomosis that supplies approximately two-thirds of the metatarsal head.
