AAOS & ABOS Orthopedic MCQs: Foot & Ankle Set 3 | Board Prep Questions

Whereas chondrosarcoma is the most frequently occurring malignant bone tumor of the foot and synovial sarcoma is the most common soft-tissue foot malignancy, the most common malignant tumor overall is melanoma. It constitutes approximately 25% of lesions found on the lower extremity. Furthermore, 31% of all melanomas arise in the foot. Mizel MS, Miller RA, Scioli MW (eds): Orthopaedic Knowledge Update: Foot and Ankle 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1998, pp 11-26.

The patient clearly has entrapment of the superficial peroneal nerve in the lateral portal. It is most likely only the medial branch by examination. If the nerve is in good condition, it can simply be released. If the nerve is cut or severely thinned, it is better excised and buried. The sural nerve most likely would be caught in a posterior-lateral portal. Jobe MT, Wright PE: Peripheral nerve injuries, in Canale ST (ed): Campbell's Operative Orthopaedics. St Louis, MO, Mosby, 1998, pp 3839-3844.

Appropriate orientation of the saw cut when performing a Weil osteotomy is approximately parallel with the plantar surface of the foot. This is done in an effort to minimize plantar displacement of the capital fragment. The removal of additional bone from the osteotomy site either by removing a separate wafer of bone or using a thicker saw blade has also been described to minimize plantar displacement of the distal fragment. Trnka H, Nyska M, Parks BG, et al: Dorsiflexion contracture after the Weil osteotomy: Results of cadaver study and three-dimensional analysis. Foot Ankle Int 2001;22:47-50.

The steel shank is a flat 1-inch steel strip placed between layers of the shoe to extend the foot lever and prevent deformity at the toe break seen following a partial first ray amputation. A rocker sole may be added as well to facilitate transition from foot flat to the toe-off phase of gait. Proper shoe fit is important, but "snug" fitting shoes in a patient with peripheral neuropathy and likely fluctuations in volume from intermittent swelling are to be avoided. A custom shoe is an unnecessary expense. The patient has at least 10 degrees of dorsiflexion at the ankle with an intact anterior tibialis muscle; therefore, catching the sole on carpeting should not be a problem. Philbin TM, Leyes M, Sferra JJ, et al: Orthotic and prosthetic devices in partial foot amputations. Foot Ankle Clin 2001;6:215-228.

Corrective osteotomy of fibular malunions, with appropriate lengthening, even in the presence of early arthritis, has been shown to decrease ankle pain and increase stability. Reduction and bone grafting of the medial malleolar nonunion is also needed. There is no evidence supporting the use of intra-articular steroids or hyaluronic acid in the ankle joint. Lateral talar displacement of even 1 mm has been reproducibly shown to decrease tibiotalar contact by 40% to 42%, causing a predisposition to arthritis. Weber D, Friederich NF, Muller W: Lengthening osteotomy of the fibula for post-traumatic malunion: Indication, technique and results. Int Orthop 1998;22:149-152. Lloyd J, Elsayed S, Hariharan K, et al: Revisiting the concept of talar shift in ankle fractures. Foot Ankle Int 2006;27:793-796. Offierski CM, Graham JD, Hall JH, et al: Later revision of fibular malunion in ankle fractures. Clin Orthop Relat Res 1982;171:145-149.

Complications of medial sesamoidectomy include stiffness, claw toe, and hallux valgus. Each sesamoid sits within its respective head of the flexor hallucis brevis tendon. Excision of one sesamoid can result in slack in its flexor hallucis brevis tendon; therefore, it is imperative to preserve or repair the flexor hallucis brevis tendon when removing the medial sesamoid. Dedmond BT, Cory JW, McBryde A Jr: The hallucal sesamoid complex. J Am Acad Orthop Surg 2006;14:745-753.

Most authors recommend an initial trial of nonsurgical management in the treatment of adult-acquired flatfoot deformity such as posterior tibial tendon dysfunction. Chao and associates found that there is high patient satisfaction with ankle-foot orthoses and UCBL-type inserts in elderly patients with a relatively sedentary lifestyle. Alternatively, there was a higher dissatisfaction rate in young active patients, those with balance and ambulation difficulties (Parkinson's, severe arthritis of the hip or knee), and patients with inflammatory systemic disorders. Chao W, Wapner KL, Lee TH, et al: Nonoperative management of posterior tibial tendon dysfunction. Foot Ankle Int 1996;17:736-741.

The first step in the treatment of an amputation residual limb (stump) ulcer is local wound care and adjustment of the residual limb-prosthetic interface, as well as adjusting prosthetic alignment. Surgical revision should be undertaken only when prosthetic modification is unsuccessful. Murnaghan JJ, Bowker JH: Musculoskeletal complications, in Smith DG, Michael JW, Bowker JH (eds): Atlas of Amputations and Limb Deficiencies, ed 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 683-700.

The spring ligament is also known as the calcaneonavicular ligament and connects the calcaneus to the navicular. This ligament supports the talar head and is an important anatomic supporting structure of the medial longitudinal arch of the foot. Choi K, Lee S, Otis JC, et al: Anatomical reconstruction of the spring ligament using peroneus longus tendon graft. Foot Ankle Int 2003;24:430-436.

The deformity is long-standing, the hindfoot is immobile, and the radiographs reveal severe degenerative arthritis involving the entire hindfoot, severe deformity, and talonavicular dislocation. The "exostosis" responsible for the callus is the talar head; resection would severely destabilize the foot. Degenerative arthritis and fixed deformity preclude lateral column lengthening, medial slide calcaneal osteotomy, and talonavicular arthrodesis. Triple arthrodesis is the only viable option. Johnson JE, Yu JR: Arthrodesis techniques in the management of Stage II and III acquired adult flatfoot deformity. Instr Course Lect 2006;55:531-542.

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%). 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.

The abductor hallucis muscle inserts together with the medial tendon of the flexor hallucis brevis into the medial base of the proximal phalanx of the great toe. When the hallux assumes a valgus position, the action of the abductor becomes one of flexion and pronation of the first metatarsal. Resch S: Functional anatomy and topography of the foot and ankle, in Myerson M (ed): Foot and Ankle Disorders. Philadelphia, PA, WB Saunders, 2000, vol 1, pp 25-49.

Owens and Thordardson cautioned surgeons not to release the conjoined tendon from the base of the proximal phalanx of the great toe because of an increased risk of iatrogenic hallux varus. Release of the transverse and oblique heads of the adductor hallucis is largely accomplished by releasing the soft tissue adjacent to the lateral sesamoid, without releasing tissue from the base of the proximal phalanx. The conjoined tendon is made up of the flexor hallucis brevis and the adductor hallucis. Owens S, Thordardson DB: The adductor hallucis revisited. Foot Ankle Int 2001;22:186-191.

Multiple authors have shown similar infection rates for grade 1 and 2 open medial fractures and closed fractures that have been treated with an extensile lateral approach and open reduction and internal fixation. Patients only need IV antibiotics for 2 to 3 days after surgery. Formal open reduction and internal fixation is not recommended for grade 3 medial wounds and most lateral wounds. Heier KA, Infante AF, Walling AK, et al: Open fractures of the calcaneus: Soft-tissue injury determines outcome. J Bone Joint Surg Am 2003;85:2276-2282.

Prospective studies, including randomized and randomized multicenter reports, have shown that percutaneous or mini-open acute Achilles tendon repair has comparable functional results when compared to traditional open techniques. Calder and Saxby reported one superficial infection out of 46 patients with a mini-open repair; Assal and associates and Cretnik and associates had no wound complications or infections. The other complications have not proved to be less likely with the mini-open or percutaneous technique. Assal M, Jung M, Stern R, et al: Limited open repair of Achilles tendon ruptures: A technique with a new instrument and findings of a prospective multicenter study. J Bone Joint Surg Am 2002;84:161-170. Calder JD, Saxby TS: Early, active rehabilitation following mini-open repair of Achilles tendon rupture: A prospective study. Br J Sports Med 2005;39:857-859.

This is an example of a missed deep posterior compartment syndrome that typically presents 6 months after the injury with progressive clawing due to necrosis, scarring, and contracture of the posterior tibial tendon, flexor digitorum longus, and flexor hallucis longus. Treatment consists of debridement of necrotic muscle and scar tissue with corresponding tendon excision. After debridement and posterior capsule release, if the equinus is relieved with knee flexion, a gastrocnemius slide may be performed. Otherwise, the lengthening should be at the level of the Achilles tendon. Bracing will not address the claw toes. Hansen ST Jr: Functional Reconstruction of the Foot and Ankle. Philadelphia, PA, Lippincott Williams & Wilkins, 2000, pp 212-213. Manoli A II, Smith DG, Hansen ST Jr: Scarred muscle excision for the treatment of established ischemic contracture of the lower extremity. Clin Orthop Relat Res 1993;292:309-314.

Chronic lateral instability is commonly associated with a longitudinal split tear of the peroneus brevis tendon. The interrelationship of lateral ankle instability with superior retinacular laxity and resultant peroneus brevis split can account for persistent lateral ankle pain in this patient. Surgical treatment must identify and correct the underlying tendon pathology and should attempt to repair or debride the peroneus brevis tendon, reconstruct the superior peroneal retinaculum, flatten the posterior edge of the fibula by removing the sharp bony prominence, or deepening the fibular groove, along with addressing lateral ankle ligamentous instability. The laboratory values are not consistent with infection. A negative anterior drawer test confirms stability of the repair. Ankle arthritis is not seen on radiographs and usually takes longer than 3 months to develop. Bonnin M, Tavernier T, Bouysset M: Split lesions of the peroneus brevis tendon in chronic ankle laxity. Am J Sports Med 1997;25:699-703.

The patient has an atypical adult flatfoot deformity. The radiographs reveal forefoot abduction, mild loss of calcaneal pitch, and marked plantar flexion sag through the naviculocuneiform joint. The inability to perform a single limb heel rise indicates that the posterior tibial tendon is nonfunctional; however, the deformity remains flexible. In this patient, surgical treatment should include a tendon transfer, lateral column lengthening, medial column arthrodesis, and heel cord lengthening. Because a substantial portion of the deformity stems from the naviculocuneiform joint in this instance, tendon transfer and lateral column lengthening alone provide insufficient deformity correction. Triple arthrodesis and heel cord lengthening is best reserved for fixed flatfoot deformities. Soft-tissue procedures alone are associated with a high failure rate, as are attempted tendon repairs. Greisberg J, Assal M, Hansen ST Jr, et al: Isolated medial column stabilization improves alignment in adult-acquired flatfoot. Clin Orthop Relat Res 2005;435:197-202.

The radiograph shows a displaced calcaneal beak fracture, a tongue-type fracture variant. The fracture fragment typically includes the insertion point of the Achilles tendon, which places marked tension on the thin overlying soft-tissue envelope and can lead to full-thickness necrosis if not acutely addressed. Cast immobilization does not adequately address the increased soft-tissue tension, as the fragment will be difficult to control. Arthroscopic-assisted techniques or primary arthrodesis are not indicated because calcaneal beak fractures are typically extra-articular. Sanders RW, Clare MP: Fractures of the calcaneus, in Coughlin MJ, Mann RA, Saltzman CL (eds): Surgery of the Foot and Ankle, ed 8. Philadelphia, PA, Mosby-Elsevier, 2007, vol 2, pp 2017-2073.

The incidence of osteonecrosis following displaced talar neck fractures is most related to the extent of initial fracture displacement. With increasing fracture displacement, the tenuous vascular supply to the talar body is more at risk for damage, thereby increasing the risk of osteonecrosis. Although displaced talar neck fractures have historically been considered a surgical emergency, recent studies have shown that the timing of surgical intervention bears no impact on the development of osteonecrosis. While nicotine use has an influence on fracture healing, it has never been shown to be a factor in osteonecrosis, nor has posterior-to-anterior screw fixation or the quality of fracture reduction. Lindvall E, Haidukewych G, Dipasquale T, et al: Open reduction and stable fixation of isolated, displaced talar neck and body fractures. J Bone Joint Surg Am 2004;86:2229-2234.

The symptoms and MRI scan indicate dislocated peroneal tendons. In this patient, the structure that needs to be repaired is the superior peroneal retinaculum. If the popping was coming from a torn peroneal tendon, repair would involve the peroneal longus or brevis tendon, but this is not shown in the MRI scan. The anterior talofibular ligament or the calcaneofibular ligament would need to be repaired if the patient had ankle instability due to an ankle sprain. Jones DC: Tendon disorders of the foot and ankle. J Am Acad Orthop Surg 1993;1:87-94.

The patient likely has a significant Achilles contracture that causes her to always bear more weight on her forefoot. A gastrocnemius recession takes the ankle out of plantar flexion and she will be able to return to a normal gait and reduce the pressures on her forefoot. A forefoot amputation is a salvage option. The other choices are appropriate; however, the patient has had this problem for 2 years and she has already had multiple attempts at shoe wear modification. Laughlin RT, Calhoun JH, Mader JT: The diabetic foot. J Am Acad Orthop Surg 1995;3:218-225.

The two sesamoids of the metatarsophalangeal joint are embedded in the tendons of the short flexor of the great toe. They are held together by the intersesamoid ligament and the plantar plate, which inserts on the base of the proximal phalanx of the hallux. The flexor hallucis longus tendon inserts onto the distal phalanx of the great toe. The plantar calcaneonavicular (spring) ligament, by supporting the head of the talus, principally maintains the arch of the foot. The plantar fascia inserts distally onto the skin and to the flexor tendons and transverse metatarsal ligaments at each metatarsophalangeal joint. The intermetatarsal ligament attaches to the base of the second through fifth metatarsals. Lewis WH (ed): Gray's Anatomy of the Human Body, ed 20. Philadelphia, PA, Lea & Febiger, 2000.

This is a nonplantigrade deformity in a patient with a Charcot foot deformity. Longitudinal studies have shown that recurrent ulceration/infection is likely unless the deformity is corrected. Achilles tendon lengthening is advised for simple forefoot ulcers. The current approach to this problem is best managed with surgical correction of the deformity, Achilles tendon lengthening, and therapeutic footwear. Bevan WP, Tomlinson MP: Radiographic measures as a predictor of ulcer formation in diabetic charcot midfoot. Foot Ank Int 2008;29:568-573. Simon SR, Tejwani SG, Wilson DL, et al: Arthrodesis as an early alternative to nonoperative management of Charcot arthropathy of the diabetic foot. J Bone Joint Surg Am 2000;82:939-950.

Several conditions must be met before a tendon transfer has the potential to correct a dynamic deformity. If the target joint cannot be passively corrected to neutral, it indicates that a static joint contracture or bony deformity exists that cannot be corrected with a dynamic tendon transfer. While in-phase muscles are best, out-of-phase muscles are often the only muscles available for transfer. Tendon transfer should pull in a straight line to avoid tethering and late failure. Canale ST (ed): Campbell's Operative Orthopaedics, ed 10. St Louis, MO, Mosby, 2003, pp 1283-1287.