AAOS & ABOS Foot & Ankle MCQs (Set 4): Ankle Fractures, Deformities & Achilles Injuries

The patient has a ligamentous Lisfranc injury. Diastasis seen between the bases of the second metatarsal and medial cuneiform is pathognomonic for a rupture of the Lisfranc's ligament. This injury is best treated surgically with either open reduction and internal fixation or possibly closed manipulation and percutaneous screw fixation if anatomic alignment can be achieved closed. Pin fixation has been shown to be inferior to screw fixation due to the length of time that fixation is required for adequate ligament healing. Chiodo CP, Myerson MS: Developments and advances in the diagnosis and treatment of injuries of the tarsometatarsal joint. Orthop Clin North Am 2001;32:11-20.

Intra-articular fractures of the calcaneus often include depression of the posterior facet of the subtalar joint. This can lead to dorsiflexion of the talus because of diminished height posteriorly. In a weight-bearing position, the dorsal surface of the talar neck can impinge against the distal tibia, causing anterior ankle pain. In addition, posttraumatic arthritis of the subtalar joint typically occurs after a calcaneus fracture. The patient's symptoms are consistent with both anterior ankle impingement and subtalar degenerative arthritis. The Bohler angle, approximately 15 degrees, confirms depression of the posterior facet. Distraction subtalar arthrodesis with a corticocancellous bone block autograft will improve talar declination, decrease anterior impingement, and address the subtalar degenerative arthritis simultaneously. Rammelt S, Grass R, Zawadski T, et al: Foot function after subtalar distraction bone-block arthrodesis: A prospective study. J Bone Joint Surg Br 2004;86:659-668.

In considering faith-based issues regarding treatment of this patient, the presence of her husband for the office visit would imply an agreement with her decision to have surgery. It also may facilitate her examination. Her role as caregiver, dietary concerns, and cleansing rituals are less important considerations with an outpatient-based procedure. Privacy concerns remain paramount to Muslim women, which include limited exposure during examination, during surgery, and in subsequent follow-up visits.

A high index of suspicion is required to identify a possible navicular stress fracture, especially in runners. High pain tolerance in the competitive athlete and often minimal swelling contribute to frequent delays in diagnosis. Localized tenderness over the dorsal navicular (so-called "N spot") in a running athlete should alert the treating physician. In this patient, the radiographs are negative and the MRI scan shows marrow edema within the navicular. This could represent a stress reaction, stress fracture, or osteonecrosis. Appropriate management should include non-weight-bearing immobilization and obtaining a CT scan to determine if a fracture is present. Early surgical treatment may be considered but only if a fracture is identified. Lee A, Anderson R: Stress fractures of the tarsal navicular. Foot Ankle Clin 2004;9:85-104.

The patient has a flexible hallux varus that is a complication of the bunion surgery. With joints that are not arthritic and still flexible, a medial release is necessary to realign the joint. The extensor hallucis longus split transfer helps maintain position and still preserve motion at the interphalangeal joint level. Arthrodesis is a salvage procedure. Soft-tissue releases alone are most likely inadequate. Excision of the lateral sesamoid is contraindicated because that further compromises the forces resisting hallux varus. Phalangeal osteotomy would not address the medial subluxation at the metatarsophalangeal joint. Richardson EG (ed): Orthopaedic Knowledge Update: Foot and Ankle 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 27-32.

Stage III hallux rigidus comprises end-stage degenerative arthritis with loss of cartilage from the phalanx and metatarsal. Therefore, cheilectomy, osteotomy, and resection arthroplasty are inadequate. Resection arthroplasty results in diminished propulsion and transfer metatarsalgia. Resurfacing implant hemiarthroplasty remains unproven for earlier stages of hallux rigidus, but is not appropriate when there is cartilage loss from the base of the proximal phalanx. First metatarsophalangeal arthrodesis has proven to be a very reliable and functional treatment of end-stage hallux rigidus. Gibson JN, Thomson CE: Arthrodesis or total replacement arthroplasty for hallux rigidus: A randomized controlled trial. Foot Ankle Int 2005;26:680-690.

The patient has a calcaneonavicular tarsal coalition. Symptoms of calcaneonavicular coalitions typically are seen between the ages of 10 and 14 years. The cause of pain has not been clearly established. It has been postulated that the coalition stiffens with maturity and microfractures can result, producing pain. Resection of a calcaneonavicular coalition generally has been associated with a satisfactory result. Soft-tissue interposition, most commonly using the extensor digitorum brevis muscle, appears to be helpful. A hindfoot arthrodesis (usually triple) would be reserved if coalition resection proves to be unsuccessful. Achilles tendon lengthening and orthotic support, as well as debridement of the sinus tarsi, are not expected to result in a satisfactory outcome. The patient does not have a flatfoot deformity. Vaccaro AR (ed): Orthopaedic Knowledge Update 8. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2005, pp 757-765.

The Ertl modification of a below-knee amputation has been proposed to create a more stable "platform" to aid in transferring the load of weight bearing between the residual limb and the prosthetic socket. It is felt that a stable platform allows total contact loading over an enlarged stable surface area. Early studies have suggested that this modification may enhance the patient's perceived functional outcome. Pinzur MS, Pinto MA, Saltzman M, et al: Health-related quality of life in patients with transtibial amputation and reconstruction with bone bridging of the distal tibia and fibula. Foot Ankle Int 2006;27:907-912.

The patient was admitted to the hospital with sepsis. The sepsis has resolved, leaving the patient with a negative nitrogen balance. Now that the patient is stable, metabolic support should be used to optimize his nutrition. If the serum albumin can be increased to 2.5 g/dL, he has an excellent potential to heal an amputation at the Syme ankle disarticulation level; a level that will optimize his functional independence. Pinzur MS, Stuck RR, Sage R, et al: Syme ankle disarticulation in patients with diabetes. J Bone Joint Surg Am 2003;85:1667-1672.

Excessive internal tibial torsion is a common cause of intoeing in toddlers. In most children, this resolves spontaneously by 3 to 4 years of age. Intoeing in elementary age children is usually the result of excessive femoral anteversion. Studies have shown that active intervention (casting, splinting, and shoe modifications) has no demonstrable effect on the natural history or resolution of tibial torsion. Surgery is rarely indicated in adolescents with severe internal tibial torsion that has not resolved and is resulting in cosmetic and functional problems. Canale ST, Beaty JH: Operative Pediatric Orthopaedics. St Louis, MO, Mosby Year Book, 1991, pp 357-385.

Arthrodesis of the talonavicular joint eliminates almost all hindfoot motion. Arthrodesis of the subtalar joint eliminates 74% of talonavicular motion and 44% of calcaneocuboid motion. Arthrodesis of the calcaneocuboid joint eliminates 33% of talonavicular motion and 8% of subtalar motion. Arthrodesis of the naviculocuneiform or cuboid-fifth metatarsal joint has limited effect on hindfoot motion. Astion DJ, Deland JT, Otis JC, et al: Motion of the hindfoot after simulated arthrodesis. J Bone Joint Surg Am 1997;79:241-246.

The patient has chronic tibial osteomyelitis that is due to low virulent bacteria. The history and studies do not suggest the need for an amputation or a free-flap procedure. This is a localized tibial infection that is in a healed bone; there is no need to resect the entire area of the tibia bone around the infection. The most appropriate treatment is curettage, debridement of nonviable bone, and placement of absorbable antibiotic beads, followed by a course of IV antibiotics from 1 to 4 weeks and a 6-week course of oral antibiotics. Studies have shown that in cases of localized osteomyelitis that are of low virulence, as little as 1 week of IV antibiotics followed by 6 weeks of oral antibiotics is successful. Patzakis MJ, Zalavras CG: Chronic posttraumatic osteomyelitis and infected nonunion of the tibia: Current management concepts. J Am Acad Orthop Surg 2005;13:417-427.

At the ankle level, the anterior tibial artery lies medial to the EHL tendon. The artery becomes the dorsalis pedis after crossing onto the dorsum of the foot. At this point, the artery lies lateral to the tendon. 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.

The area of the tendon degeneration is greater than 50% of the width so a supplemental tendon transfer is needed. Debridement and repair alone do not provide adequate strength. Injection risks tendon rupture. Brisement is indicated for peritendinitis, not tendinosis. Nonsurgical management is unlikely to be of benefit after 12 months. Richardson EG (ed): Orthopaedic Knowledge Update: Foot and Ankle 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 94-95.

The structure labeled "A" is a peroneus quartus, a supernumary muscle arising most commonly from the peroneus brevis. The presence of peroneus quartus is not uncommon, with an incidence of up to 21%, and is associated with lateral ankle pain and peroneal tendon symptoms, theoretically as a result of mass effect within the peroneal tendon sheath. Zammit J, Singh D: The peroneus quartus muscle: Anatomy and clinical relevance. J Bone Joint Surg Br 2003;85:1134-1137.

These lesions are emboli related to the cardiac surgery, and the patient is already on anticoagulation medication. The foot reveals no signs consistent with gangrene or infection. Unless the patient shows local or systemic signs of sepsis, the best management is observation. It is unlikely that formal debridement will be necessary. Bowker JH, Pfeiffer MA (eds): The Diabetic Foot. St Louis, MO, Mosby, 2001, pp 219-260.

Passive dorsiflexion is adequate to accommodate standing erect without excessive pressure, and a gastrocnemius recession may lead to more instability. Complete excision of the medial sesamoid could lead to an iatrogenic hallux valgus deformity. She does not have a cock-up toe deformity; therefore, a flexor hallucis longus tendon transfer is not warranted. There is no significant foot deformity; therefore, a dorsiflexion osteotomy is not warranted. The appropriate procedure is planing of the plantar half of the medial sesamoid, thereby preserving its function while diminishing the excessive pressure. Grace DL: Sesamoid problems. Foot Ankle Clin 2000;5:609-627. Mizel MS, Miller RA, Scioli MW (ed): Orthopaedic Knowledge Update: Foot and Ankle 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1998, pp 135-150.

The most common inherited neuromuscular disease seen by orthopaedic surgeons is CMT, which is an inherited autosomal-dominant disease. It is more commonly seen in men due to the nature of the inheritance. Identification of cavus deformity in the foot of a child should arouse suspicion. Richardson EG (ed): Orthopaedic Knowledge Update: Foot and Ankle 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 135-143. Charcot-Marie-Tooth Disease (CMT) Penn State Hershey Medical Center. www.hmc.psu.edu/healthinfo/c/cmt.htm

When performing a gastrocnemius slide at the tendinous portion of the gastrocnemius insertion, the sural nerve and saphenous vein, which tend to run midline posterior at this level, must be protected and retracted laterally. An anatomic study of the sural nerve at this level localized the nerve superficial to the deep fascia overlying the gastrocnemius in 42.5% of the cases; deep to the superficial fascia in 57.5% of the cases, and directly applied to the gastrocnemius tendon in 12.5% of cases. Pinney SJ, Sangeorzan BJ, Hanen ST Jr: Surgical anatomy of the gastrocnemius resection (Strayer procedure). Foot Ankle Int 2004;25:247-250.

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. Weening B, Bhandari M: Predictors of functional outcome following transsyndesmotic screw fixation of ankle fractures. J Orthop Trauma 2005;19:102-108.

A farm injury is automatically considered a grade III (Gustillo classification) injury regardless of size, energy, or additional soft-tissue injury due to the likelihood of substantial contamination. Antibiotic recommendations for grade III injuries include a first- or second-generation cephalosporin with an aminoglycoside or fluoroquinolone within 3 hours of injury, with penicillin added for farm injuries. Okike K, Bhattacharyya T: Trends in the management of open fractures: A critical analysis. J Bone Joint Surg Am 2006;88:2739-2748.

Absolute toe pressures greater than 40 to 50 mm Hg are a good sign of healing potential. An ABI of greater than 0.45 favors healing, but indices greater than 1 are falsely positive due to calcifications in the vessels. Normal albumin is an overall indication of nutritional status. A transcutaneous oxygen level should be greater than 40 mm Hg for healing. Mizel MS, Miller RA, Scioli MW (eds): Orthopaedic Knowledge Update: Foot and Ankle 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1998, pp 113-122.

Clinical studies have shown that smoking cessation for 4 weeks reduces the risk of infection to the level of nonsmokers. Adverse effects on wound healing caused by chemotherapy used to treat rheumatoid arthritis has not been borne out in the literature. Bibbo C, Anderson RB, Davis WH, et al: The influence of rheumatoid chemotherapy, age, and presence of rheumatoid nodules on postoperative complications in rheumatoid foot and ankle surgery: Analysis of 725 procedures in 104 patients. Foot Ankle Int 2003;24:40-44. Bibbo C, Goldberg JW: Infections and healing complications after elective orthopaedic foot and ankle surgery during tumor necrosis factor-alpha inhibition therapy. Foot Ankle Int 2004;25:331-335.

Intrinsic muscles of the foot function to flex the metatarsophalangeal joints and extend the interphalangeal joints. Myerson MS, Shereff MJ: The pathologic anatomy of claw and hammertoes. J Bone Joint Surg Am 1989;71:45-49.

The history and presentation are consistent with type I Charcot-Marie-Tooth (CMT), the most common form of hereditary peripheral motor sensory neuropathy. Type I CMT is the most common, occurring in 50% of patients with CMT, and is characterized by marked slowing of motor neuron velocities, and inconsistent slowing of sensory neuron velocities. Peroneus longus to brevis transfer is indicated to release the overpull of the peroneus longus, and restore the eversion and dorsiflexion function of the peroneus brevis. A lateralizing calcaneal osteotomy with proximal translation is indicated to correct heel varus given that the Coleman block only allows for partial correction of heel varus. Proximal translation of the posterior tuber corrects for the increased calcaneal dorsiflexion, improving the lever arm for the triceps surae. A medial column closing wedge osteotomy is often required to correct a rigid, or semirigid plantar flexed first ray to allow for a balanced, plantigrade foot. Triple arthrodesis is indicated for rigid, arthritic hindfoot deformities. Transfer of the posterior tibial tendon to the tibialis anterior is not indicated since it is an out-of-phase transfer. Transfer of the posterior tibial tendon, when performed, should be to the lateral aspect of the foot. A medializing calcaneal osteotomy would accentuate the heel varus. There is no indication for Botox in CMT; Botox injection of the calf would further weaken push-off during gait. Bracing of a progressive semirigid or rigid deformity is not recommended. Younger AS, Hansen ST Jr: Adult cavovarus foot. J Am Acad Orthop Surg 2005;13:302-315. Sammarco GJ, Taylor R: Cavovarus foot treated with combined calcaneus and metatarsal ostetotomies. Foot Ankle Int 2001;22:19-30.