Foot and ankle

Question 1

Keller resection arthroplasty

Answer 1

• operative tx for diabetic foot ulcers
• indications: IPJ plantar neuropathic ulcer w/ hypomobile/stiff MTPJ that has failed total contact casting
• involves motion restoration at the MTPJ through basal resection of the proximal phalanx

Question 2

what does worsening glycemic control in a diabetic pt w/ foot ulcer suggest?

Answer 2

• worsening glycemic control is an indicator of worsening infection
• consider obtaining advanced imaging to further assess extent of infection

Question 3

Common criteria for revascularization of circulatory compromise in diabetic foot?

Answer 3

• ABI < 0.45
• systolic ankle pressure < 55mmHg
• toe pressure < 30mmHg
• transcutaneous oxygen pressure < 30mmHg

Question 4

Indications and contraindications for total contact casting (TCC) in a diabetic foot?

Answer 4

• indications: gold standard for mechanical relief of plantar ulcerations
• absolute contraindications: infection
• relative contraindications: marginal arterial supply to affected area, pts unable to comply w/ cast care, pts unable to tolerate a cast

Question 5

when bone is probed in a diabetic ulcer, what is the likelihood of osteomyelitis being present?

Answer 5

60-70%

Question 6

forefoot ulcerations in neuropathy

Answer 6

• result of increased pressure
• frequently associated w/ tight heel cord
• lesions under 1st metatarsal head often have an associated overpull of the peroneus longus, plantar flexing the first metatarsal
• before bony resections are contemplated, a fractional lengthening of the heel cord (gastrocsoleus recession) as well as peroneal longus to brevis tendon transfer will decrease the forefoot pressures and lead to decreased ulcer recurrence rates

Question 7

what is the biggest predictor of eventual lower extremity amputation in diabetics?

Answer 7

Presence of a diabetic ulcer

Question 8

Risk factors associated w/ poor healing response in diabetic foot ulcers?

Answer 8

• lymphocyte count < 1500
• albumin < 3.5
• ABI < 0.45
• transcutaneous oxygenation pressures < 20-30 mmHg

Question 9

clinical finding that has been found to be most specific for bony involvement of osteomyelitis in diabetic foot ulcer?

Answer 9

Ulcer that probes directly to bone

Question 10

how to manage isolated forefoot gangrene in the presence of a palpable posterior tibial artery pulse?

Answer 10

Syme amputation (ankle disarticulation, removal of malleoli, and anchoring heel pad to the WB surface)
-viable heel pad is critical for success (blood supply from branches of posterior tibial artery)

Question 11

The primary risk factor for the development of a diabetic foot ulcer is loss of protective sensation and this is commonly tested w/ a 5.07 Semmes-Weinstein monofilament. Once an ulcer is present, non-invasive vascular evaluation is performed to determine ulcer healing potential via ABI or transcutaneous oxygen pressure.

Answer 11

.

Question 12

Silverskiold test

Answer 12

• differentiates isolated contractures of the gastrocnemius from the gastrocsoleus complex
• forefoot is inverted and hind foot is positioned in subtalar neutral to lock the transverse tarsal joints; knee is first flexed w/ ankle dorsiflexion and then compared to passive ankle dorsiflexion w/ knee extended; isolated gastroc contracture present if dorsiflexion is INCREASED during knee FLEXION compared to knee extension and indicated that an isolated gastrocnemius fascia lengthening (Strayer procedure) is sufficient. If there is an equinus contracture that does not improve w/ knee flexion, then the entire gastrocsoleus complex is contracted and an achilles tendon lenghtening (Hoke procedure) is required.

Question 13

2 most common locations for tarsal coalition?

Answer 13

• Talocalcaneal

- Calcaneonavicular

Question 14

plantar plate deficiency of the second joint.

Answer 14

Plantar plate deficiency often results in chronic forefoot pain, often in the second toe. The most common complaint is focal pain under the second toe MTP joint. Drawer testing of the MTP joint is an objective test to evaluate the integrity of the plantar plate. The radiographs of the foot reveal a long metatarsal and a dorsiflexion deformity at the second MTP joint. The recommended initial treatment for plantar plate deficiency is unloading of the joint with foot orthotics with metatarsal pads.

Question 15

best imaging study to differentiate Charcot arthropathy from infection or both concurrently?

Answer 15

MRI combined w/ Indium 111 scan

Question 16

bunionette deformity

Answer 16

The pain over the fifth MTP joint is secondary to the relative prominence of the fifth metatarsal head secondary to the deformity. The radiographs reveal a type 2 deformity with lateral bowing in the distal aspect of the fifth metatarsal without any enlargement of the metatarsal head. In discussing bunionettes, three types have been described: type I: enlargement of the first metatarsal head; type II: lateral bowing in the distal half of the fifth metatarsal; type III: widened fourth and fifth intermetatarsal angle. Surgical treatment is dictated by the bunionette type: type 1: partial lateral condylectomy; type 2: distal chevron osteotomy; type 3: midshaft diaphyseal osteotomy.

Metatarsal head resection has no role in the treatment of bunionette deformities and is more commonly associated with treatment of patients with autoimmune disorders and treatment of chronically dislocated toe. In cases of revision or salvage, metatarsal head resection can be considered an option, but it is not appropriate as an initial treatment consideration.

Question 17

which nerve is most at risk during endoscopic excision of a symptomatic os trigonum?

Answer 17

Sural nerve

Question 18

Patients who undergo transtibial amputation must exert which percentage of increased energy for ambulation as compared to baseline?

Answer 18

25%
-Patients who undergo transfemoral amputation exert 65% more energy for ambulation compared to baseline. Patients with transtibial amputations exert 25% more energy compared to baseline.

Question 19

Most common location for tarsal coalitions?

Answer 19

-Talocalcaneal and Calcaneonavicular joints

Question 20

Bunion treatment options (angles)?

Answer 20

The IMA between the first and second metatarsals as well as the HVA must be measured. If the IMA is smaller than 15 degrees and the HVA is smaller than 35 degrees, a distal osteotomy is preferred. Distal soft-tissue reconstruction is only useful for IMAs smaller than 11 degrees and HVAs smaller than 25 degrees. Proximal osteotomies and the Lapidus bunionectomy are reserved for larger hallux valgus deformities with IMAs exceeding 15 degrees and HVAs exceeding 35 degrees.