8. Foot and Ankle MCQs

Empathy during the interview demonstrates compassion and earns the patient's trust; which, in turn, enables the patient to discuss any agenda or concerns he or she may otherwise feel uncomfortable revealing. It is also important to engage the patient to establish a trusting relationship and thus understand all the factors impacting the patient. A formal attitude toward the patient makes it difficult to engage the patient to be "drawn in." An engaged patient is more comfortable, reliable, and thorough when providing a history. Closed-end, yes-no questions do not allow the patient to detail all of the subtle nuances of their condition and its effect on their life. Taking copious notes likewise prevents engagement of the patient and the distraction of taking notes may cause the physician to miss an important detail. It is better to lean forward in a chair when interviewing a patient because this suggests the physician is genuinely interested, whereas leaning back in a chair suggests the physician is simply waiting for the patient to finish talking. Avoid interrupting the patient when talking.

Tarsal coalitions commonly present in the preadolescent age group as a rigid, planovalgus foot. Small coalitions of the calcaneonavicular joint or the middle facet of the talocalcaneal joint can be excised with interposition of fat or muscle tissue. Isolated calcaneocuboid joint coalitions are very rare. This patient has an associated large talocalcaneal coalition; therefore, resection is contraindicated. Surgery is warranted after failure of nonsurgical management, and because of the involvement of two joints, the only viable option for the severely symptomatic foot is triple arthrodesis.

DISCUSSION: Following failure of physical therapy and pharmacologic management in a patient with complex regional pain syndrome, the management of choice is sympathetic blocks. While continued physical therapy would be assistive, sympathetic blocks allow a more rapid relief of symptoms. Neurostimulation is not appropriate at this stage because of its invasive nature. REFERENCES: Cepeda MS, Lau J, Carr DB: Defining the therapeutic role of local anesthetic sympathetic blockade in complex regional pain syndrome: A narrative and systematic review. Clin J Pain 2002;18:216-233. Perez RS, Kwakkel G, Zuurmond WW, et al: Treatment of reflex sympathetic dystrophy (CRPS type 1): A research synthesis of 21 randomized clinical trials. J Pain Symptom Manage 2001;21:511-526. Tran KM, Frank SM, Raja SN, et al: Lumbar sympathetic block for sympathetically maintained pain changes in cutaneous temperatures and pain perception. Anesth Analg 2000;90:1396-1401. Stanton-Hicks M, Baron R, Boas R, et al: Complex regional pain syndromes: Guidelines for therapy. Clin J Pain 1998;14:155-166.

DISCUSSION: The patient has a symptomatic os trigonum caused by impingement that occurs with maximal plantar flexion of the ankle in the demi-pointe or full-pointe position. Patients frequently report posterolateral pain localized behind the lateral malleolus that may be misinterpreted as a disorder of the peroneal tendon. Pain with passive plantar flexion (the plantar flexion sign) indicates posterior impingement, not a problem with the peroneal tendon. The symptoms are not characteristic of a stress fracture, nor do the radiographs show a stress fracture or an osteochondritis dissecans lesion. The os trigonum is modest in its dimensions. The incidence or magnitude of symptoms does not correlate with the size of the fragment. Large fragments may be asymptomatic, while small lesions may create significant symptoms. REFERENCES: Marotta JJ, Micheli LJ: Os trigonum impingement in dancers. Am J Sports Med 1992;20:533-536. Hamilton WG: Foot and ankle injuries in dancers, in Mann RA, Coughlin MJ (eds): Surgery of the Foot and Ankle, ed 6. St Louis, MO, CV Mosby, 1993, pp 1241-1276.

DISCUSSION: Because the patient is essentially asymptomatic, the most appropriate course of action is observation. Prophylactic hallux valgus surgery is not medically indicated. Steroid injection would only risk infection, as well as joint and capsule damage. There are no data to support the use of a custom orthosis to delay the progression of a hallux valgus deformity. Special shoe wear or an extra-depth shoe is not necessary and is unlikely to be accepted by the patient. REFERENCES: Donley BG, Tisdel CL, Sferra JJ, Hall JO: Diagnosing and treating hallux valgus: A conservative approach for a common problem. Cleve Clin J Med 1997;64:469-474. Teitz CC, Hu SS, Arendt EA: The female athlete: Evaluation and treatment of sports-related problems. J Am Acad Orthop Surg 1997;5:87-96.

DISCUSSION: This patient appears to have adequate blood supply to heal a Syme’s ankle disarticulation but is currently malnourished because of the systemic infection, and is likely to progress to wound failure. Therefore, the initial management of choice is culture-specific antibiotic therapy, open wound management, and nutritional supplementation. If his serum albumin rises to a minimum of 2.5 gm/dL, he can undergo elective Syme’s ankle disarticulation. If the serum albumin does not rise within a short period of time, he should undergo transtibial amputation. REFERENCE: Pinzur MS, Stuck RM, Sage R, et al: Syme ankle disarticulation in patients with diabetes. J Bone Joint Surg Am 2003;85:1667-1672.

The presence of a dorsal ulcer in the presence of weak or absent pulses strongly suggests the possibility of arterial insufficiency. The best initial noninvasive study to assess for ischemia is the Doppler arterial study. A determination of the vascular status is of a greater priority than an assessment for infection or neuropathy because of the location and presentation of the ulcer. If ankle pressures are less than 45 mm Hg, there is a high risk that these lesions will not heal without revascularization.

The tibial nerve gives off two branches. In the distal 1/3 of the leg, the tibial nerve curves anteroinferiorily into the sole of the foot behind the medial malleolus, deep to the flexor retinaculum and between the tendons of the flexor hallicus longus and the flexor digitorum longus muscles. Just distal to the flexor retinaculum, the tibial nerve divides into the medial and lateral plantar nerve. At this site, the lateral plantar nerve gives off its first branch which lies anterior and adjacent to the abductor hallicus.

DISCUSSION: The most important determining factor for correction of an adult flatfoot without an arthrodesis is the flexibility of the subtalar and transverse tarsal joints. Rigid deformities cannot be corrected with a medial sliding calcaneal osteotomy with FDL transfer or a subtalar arthroereisis. Isolated subtalar or talonavicular arthrodesis does not correct the deformities entirely. If the patient has forefoot supination that can be corrected to less than 7°, an isolated subtalar fusion is a possible alternative. REFERENCE: Mann RA: Flatfoot in adults, in Coughlin MJ, Mann RA (eds): Surgery of the Foot and Ankle, ed 6. St Louis, MO, Mosby, 1993, pp 757-784.

DISCUSSION: In one series, only 44% of patients demonstrated good results from tarsal tunnel decompression if they did not have a mass in the tarsal tunnel. Conditions that produce a traction neuropathy of the posterior tibial nerve are unlikely to respond to neurolysis. The most favorable condition associated with a good response to decompression is when a compressing anatomic structure can be removed from the tarsal tunnel. REFERENCES: Frey C, Kerr R: Magnetic resonance imaging and the evaluation of tarsal tunnel syndrome. Foot Ankle 1993;14:159-164. Garrett AL: Poliomyelitis, in Nickel VL (ed): Orthopaedic Rehabilitation. New York, NY, Churchill Livingston, 1982, pp 449-458. Pfeiffer WH, Cracchiolo A III: Clinical results after tarsal tunnel decompression. J Bone Joint Surg Am 1994;76:1222-1230.

Figure A represents a type 3 Hawkins talar neck fracture. A type 3 injury is defined as a displaced fracture of the talar neck with dislocation of body of talus from both the subtalar joint and the tibiotalar joint. In these injuries, the talar body fragment typically rotates around intact deltoid ligament fibers to lie in soft tissues with the fracture surface pointing laterally and cephalad. Often, the deltoid branch of the posterior tibial artery, which lies between the leaves of the deltoid ligament and supplies up to 1/2 of the medial talar body, is the only remaining blood supply. Therefore, the deltoid ligament must be preserved to lower the risk of avascular necrosis. When performing a medial malleolar osteotomy, the deltoid ligament must remain in continuity with the malleolus to prevent disruption of the blood supply.The review article by Fortin et al discusses talar blood supply, injury mechanisms and classifications, and treatment options. They state that the main artery to the body of the talus is the artery of the tarsal canal, which is a branch of the posterior tibial artery. The peroneal and anterior tibial artery also contribute branches to the talus.Illustration A and B show the arterial network of the talus.OrthoCash 2020

Fractures of the calcaneus occur as a result of shear and compression forces. Foot position at the time of impact, the force of the impact, and bone quality all dictate the degree of comminution and fracture line orientation. Two primary fracture lines are consistently observed, one of which divides the calcaneus into medial and lateral portions. An essential feature of this fracture line is that it creates a fragment (sustentaculum tali) that remains attached to the talus by the interosseous ligament. This medial portion (constant fragment) of the posterior facet retains its normal anatomic position beneath the posterior talus. Its corresponding lateral component (labeled with an * in the figure), however, can be found displaced inferiorly within the body of the calcaneus. It is often rotated 90 degrees (as depicted in Figure 28) in relation to the remainder of the subtalar joint. This gives the appearance of what has been described as the "double-density" sign. The middle facet is more anterior and less commonly displaced. The lateral wall is nonarticular.

The indications for a free flap coverage for the foot and ankle include loss of skin and subcutaneous tissue with exposed bone, tendon, and neurovascular structures and, on occasion, surgical hardware; local options are not available or feasible and coverage is necessary to providehealing and survival of the underlying structures, prevent infection, and provide a durable and/or flexible cover. Furthermore, the standard cross-leg flap no longer is used because of significant problems with positioning and joint stiffness, and because it provides inadequate coverage material. For the various surfaces of the ankle and dorsum of the foot, very few local tissues are available to provide coverage when free skin grafting is insufficient. Thus, out of the possible answers, free rectus abdominis flap is the preferred response.

DISCUSSION: The photographs show a planovalgus posture of the foot. The foot deformity and decreased inversion strength are secondary to laceration of the posterior tibial tendon 18 months ago. If the injury had been recognized acutely, optimal treatment would have consisted of repair of the tendon; however, contracture now precludes that possibility. Therefore, transfer of the flexor digitorum longus or flexor hallucis longus is the preferred treatment. In adults with posterior tibial dysfunction, the entire tendon is typically degenerated and the transfer must be anchored through a drill hole in the navicular. In this patient, the distal end of the posterior tibial tendon is a satisfactory insertion site. Lengthening osteotomy of the calcaneus could be combined with the tendon transfer if the patient had a fixed deformity of the foot. UCBL orthoses and an ankle-foot orthosis are not considered good long-term solutions for a 12-year-old patient. REFERENCES: Mosca VS: Flexible flatfoot and skewfoot, in Drennan JC (ed): The Child’s Foot and Ankle. New York, NY, Raven Press, 1992, pp 355-376. Myerson MS: Adult acquired flatfoot deformity: Treatment of dysfunction of the posterior tibial tendon, in Springfield DS (ed): Instructional Course Lectures 46. Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1997, pp 393-405.

DISCUSSION: Radiographs reveal a Lisfranc fracture dislocation with fractures of the first and second metatarsals. Tenting of skin that is over a bony prominence is an orthopaedic emergency. The fracture dislocation should be reduced without delay. There is no evidence of compartment syndrome of the foot, but this may develop and monitoring is necessary. Toe deformity may develop on a delayed basis because of the subclinical presentation. Nerve irritation is not uncommon with dorsal midfoot surgical incisions. A positive Tinel test result over the midfoot in the distribution of the superficial common peroneal nerve is consistent with a stretch injury to this nerve. CRPS is usually associated with multiple nerve distributions and autonomic nerve findings such as cold hypersensitivity and hyperhidrosis. RECOMMENDED READINGS: Benirschke SK, Meinberg EG, Anderson SA, Jones CB, Cole PA. Fractures and dislocations of the midfoot: Lisfranc and Chopart injuries. Instr Course Lect. 2013;62:79-91. PubMed PMID: 23395016. Schepers T, Oprel PP, Van Lieshout EM. Influence of approach and implant on reduction accuracy and stability in Lisfranc fracture-dislocation at the tarsometatarsal joint. Foot Ankle Int. 2013 May;34(5):705-10. doi: 10.1177/1071100712468581. Epub 2013 Jan 14. PubMed PMID: 23637239.

DISCUSSION: 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. REFERENCES: Philbin TM, Leyes M, Sferra JJ, et al: Orthotic and prosthetic devices in partial foot amputations. Foot Ankle Clin 2001;6:215-228. Pinzur MS, Dart HC: Pedorthic management of the diabetic foot. Foot Ankle Clin 2001;6:205-214.

DISCUSSION: The first branch of the lateral plantar nerve is susceptible to entrapment beneath the deep fascia of the adductor hallucis muscle adjacent to the calcaneal attachment of the plantar fascia. This can be a cause of chronic heel pain. Additionally, the nerve is vulnerable to injury by a blind dissection in releasing the plantar fascia. The dorsal cutaneous branch of the superficial peroneal nerve supplies sensation to the dorsum of the foot. The medial calcaneal branch of the posterior tibial nerve lies in the subcutaneous tissues and innervates the skin of the heel. It is vulnerable to injury from skin incisions on the medial side of the heel. The lateral branch of the medial plantar nerve forms the second and third common digital nerves. Entrapment of the proper medial plantar nerve can occur at the master knot of Henry. This is well distal to the calcaneal attachment of the plantar fascia, and the pain usually radiates more distally in the arch, separate from heel pain. The communicating branch of the fourth common digital nerve crosses to the third common digital nerve. Therefore, the third common digital nerve receives supply from both the lateral and medial plantar nerves. This dual supply has been implicated in the increased incidence of digital neuroma of the third common digital nerve. REFERENCES: Bordelon RL: Heel pain, in Mann RA, Coughlin MJ (eds): Surgery of the Foot and Ankle, ed 6. St Louis, MO, CV Mosby, 1993, pp 837-857. Mann RA, Baxter DE: Diseases of the nerves, in Mann RA, Coughlin MJ (eds): Surgery of the Foot and Ankle, ed 6. St Louis, MO, CV Mosby, 1993, pp 543-574. Baxter DE: The heel in sport. Clin Sports Med 1994;13:683-693.

DISCUSSION: The contents of the anterior tarsal tunnel are the extensor hallucis longus, tibialis anterior, extensor digitorum longus, dorsalis pedis artery, and the deep peroneal nerve. The term “anterior tarsal tunnel syndrome” is used to specifically describe the compression of the deep peroneal nerve under the inferior extensor retinaculum. With nerve compression, patients report a burning sensation across the dorsum of the foot with paresthesias in the first web space. There also may be wasting and weakness of the extensor digitorum brevis. REFERENCES: Kuritz HM: Anterior entrapment syndromes. J Foot Surg 1976;15:143-148. Sarrafian S: The Anatomy of the Foot and Ankle: Descriptive, Topographic, Functional, ed 2. Philadelphia, PA, JB Lippincott, 1993, pp 113-158.

DISCUSSION: Surgical treatment is indicated for a symptomatic tarsal coalition that has failed to respond to nonsurgical management. In this patient, the radiographs reveal a calcaneonavicular coalition and no degenerative changes. The patient is symptomatic, and two attempts at use of a short leg walking cast have failed to provide relief. For calcaneonavicular coalitions, good results have been reported following resection and interposition of the extensor digitorum brevis. A retrospective study of this procedure achieved good to excellent results in 58 of 75 feet (77%). Degenerative arthritis or persistent pain following resection of a coalition is a reasonable indication for a triple arthrodesis. A medial closing wedge osteotomy of the calcaneus may be indicated for a rigid flatfoot with severe valgus deformity. There are no studies documenting the long-term effectiveness of a manipulation under general anesthesia for this condition. REFERENCES: Gonzalez P, Kumar SJ: Calcaneonavicular coalition treated by resection and interposition of the extensor digitorum brevis muscle. J Bone Joint Surg Am 1990;72:71-77. Richards BS (ed): Orthopaedic Knowledge Update: Pediatrics. Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1996, pp 211-218.

DISCUSSION: The radiographs demonstrate persistent widening of the medial clear space with an ossicle. This represents soft-tissue interposition-scar tissue, the deltoid ligament, or the posterior tibialis tendon. Physical therapy will not improve the symptomatic malalignment. Hardware removal would be indicated for pain localized to the lateral fibula. Repeat syndesmotic screw fixation alone will not reduce the malalignment. Deltoid ligament repair may be necessary but will need to be combined with debridement of the medial ankle and syndesmosis, as well as repeat placement of one or more syndesmotic screws to maintain the reduction. REFERENCES: Weening B, Bhandari M: Predictors of functional outcome following transsyndesmotic screw fixation of ankle fractures. J Orthop Trauma 2005;19:102-108. Harper MC: Delayed reduction and stabilization of the tibiofibular syndesmosis. Foot Ankle Int 2001;22:15-18.