8. Foot and Ankle MCQs

DISCUSSION: Talar compression syndrome is also known as os trigonum syndrome or posterior ankle impingement syndrome and occurs in activities involving extreme ankle plantar flexion. It involves pinching of the posterior talus (os trigonum or posterior process of the talus) between the calcaneus and tibia. The flexor hallucis longus also may be impinged. The other structures are not commonly injured in this syndrome.

DISCUSSION: The patient has cavus feet with minimal clinical symptoms. At this stage, conservative management is preferred. The use of a molded orthosis will allow better support of the midfoot and provide cushioning of the forefoot. This will most likely result in long-term relief. In more advanced cases with forefoot callus formation, Achilles tendon lengthening or calcaneal osteotomy and Steindler stripping are effective in correcting the cavus deformity. In the presence of arthritic changes in the hindfoot, a triple arthrodesis with corrective bone resection may be necessary.

Hallux varus-The question does not specify proximal or distal osteotomies, however it is the most common complication with overcorrection of proximal 1st metatarsal osteotomies. Mann. Pg. 329. “Transfer” 2nd metatarsaglia-most significant, not most common, complication of the Mitchell Osteotomy.Mann pg. 319.Physeal arrest of the first metatarsal-“While an open epiphysis cannot be considered an absolute contraindication to an osteotomy in either the proximal phalanx, or proximal first metatarsal, it isimportant at surgery to determine the exact location of the metaphyseal epiphysis to avoid injury.” Pg. 307 Mann, Surgery of Foot and Ankle.In studies performed by Blais et. Al. A females full foot growth is usually achieved by 14 years and at 12 years an average less than 1 cm of total foot growth remains with less than 50% of this growth at the proximal epiphysis. Males’ terminal growth expected at 16 years of age with 3cm left at 12 years and approximately 1.5 cm of metatarsal growth.Most studies show recurrence of Hallux Valgus deformity after surgical correction in the juvenile as inordinately high.

Rheumatoid arthritis commonly affects the metatarsophalangeal joints, which become destabilized with time resulting in hallux valgus and dislocated lesser claw toes. The result is metatarsalgia as the dislocated claw toes “pull” the fat pad distally. Severe hallux valgus reduces first ray load, which compounds the metatarsalgia because the load is transferred to the lesser metatarsal heads. First metatarsophalangeal arthrodesis restores weight bearing medially and corrects the painful bunion. Metatarsal head resection slackens the toe tendons to allow correction of the claw toes by whatever means necessary and decreases plantar load over the forefoot. Rheumatoid arthritis in the first metatarsophalangeal joint will continue to progress if osteotomies or a Lapidus procedure are performed. Keller resection arthroplasty increases transfer metatarsalgia and reduces push-off power during gait. Flexor-to-extensor tendon transfer of the lesser toes does not address the metatarsalgia and does not correct the dislocation of the metatarsophalangeal joint.

DISCUSSION: Turf toe, or capsuloligamentous injury to the first MTP joint, most commonly is caused by an axial load being applied to a fixed, dorsiflexed great toe with the heel off the ground. The external force causes further dorsiflexion of the great toe, leading to injury to the capsuloligamentous complex. A less common mechanism of turf toe is hyperplantarflexion of the great toe with valgus stress, which is seen in beach volleyball players. RECOMMENDED READINGS: Kadakia AR, Molloy A. Current concepts review: traumatic disorders of the first metatarsophalangeal joint and sesamoid complex. Foot Ankle Int. 2011 Aug;32(8):834-9. Review. PubMed PMID: 22049873. Clanton TO, McGarvey W. Athletic Injuries to the soft tissues of the foot and ankle. In: Coughlin MJ, Mann RA, Saltzman CL, eds. Surgery of the Foot and Ankle. 8th ed. Philadelphia, PA: Mosby-Elsevier; 2007:1526-1535

DISCUSSION: Diabetes mellitus, obesity, and exposure to steroids have all been associated with the development of Achilles tendinopathy. In addition, Achilles tendinopathy has been associated with a history of hormone replacement therapy and the use of oral contraceptives. Quinolone antibiotics have also been linked to Achilles tendinopathy. Estrogen deficiency is not typically cited as a primary risk factor for Achilles tendinopathy. REFERENCES: Holmes GB, Lin J: Etiologic factors associated with symptomatic Achilles tendinopathy. Foot Ankle Int 2006;27:952-959. Holmes GB, Mann RA, Well L: Epidemiological factors associated with rupture of the Achilles tendon. Contemp Orthop 1991;23:327-331.

DISCUSSION: Angular deformities of the ankle can occur following physeal injury. While an orthosis may be beneficial, the deformity is at the level of the ankle rather than the hindfoot. An epiphysiodesis or physeal bar resection would not be indicated as the growth plates are closed. Correction of the angular deformity should level the ankle joint and normalize the weight-bearing stresses on the ankle. This is most easily achieved with a closing wedge distal tibial osteotomy with or without concomitant osteotomy of the fibula. REFERENCES: Thompson DM, Calhoun JH: Advanced techniques in foot and ankle reconstruction. Foot Ankle Clin 2000;5:417-442. Ting AJ, Tarr RR, Sarmiento A, Wagner K, Resnick C: The role of subtalar motion and ankle contact pressure changes from angular deformities of the tibia. Foot Ankle 1987;7:290-299. Tarr RR, Resnick CT, Wagner KS, Sarmiento A: Changes in tibiotalar joint contact areas following experimentally induced tibial angular deformities. Clin Orthop 1985;199:72-80.

Discussion: The radiographs reveal a trimalleolar ankle fracture dislocation with an associated distal tibiofibular syndesmotic disruption. Medial and lateral malleolar stabilization are consistently agreed upon. The decision to stabilize the posterior malleolus is more controversial. Posterior malleolar stabilization restores incisura competence, thereby reducing the incidence of syndesmotic malreduction by creating containment, assists in stabilizing the syndesmosis via the posterior inferior tibiofibular ligament, potentially limiting the need for additional syndesmotic stabilization, maximizes the surface area for ankle joint loading, and enhances posterior translational stability of the talus. Because of the additive syndesmotic stability gained through the deep deltoid ligament and medial malleolar fixation, the anterior talofibular ligament and lateral malleolar fixation, and the posterior inferior tibiofibular ligament and posterior malleolar fixation, syndesmotic stability should only be assessed after all other points of instability that are planned for fixation are fixed.

Arthritis of the ankle and hindfoot can pose challenges. Depending upon patient age, comorbidities, and alignment, a variety of surgical interventions may be offered. A total ankle replacement may be considered for patients older than 60 years of age who have minimal misalignment and low-demand lifestyles. In all other cases, ankle fusion must be considered. Patients with diabetes and Charcot arthropathy may be treated nonsurgically with total-contact casting during acute and active or "hot" phases and accommodative shoes during consolidation and stable or "cool" phases. When the patient has recurrent ulcers or major anatomy changes, surgical intervention must be considered. Tibiotalocalcaneal fusion helps to realign the foot and ankle and make it more braceable in the setting of ankle and hindfoot Charcot disease.

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.

DISCUSSION: The distal oblique shortening (Weil) metatarsal osteotomy has not been associated with transfer lesions to the extent of other shortening osteotomies, and malunions and nonunions are unusual complications. Recurrent dorsal contracture of the toe has been reported. A potential cause suspected for this phenomenon is the relatively dorsal positioning of the intrinsic tendons after plantar displacement of the metatarsal head.

DISCUSSION: The patient has a supple planovalgus deformity that is passively fully correctable, and nonsurgical management has failed to provide relief. Lateral column lengthening with medial soft-tissue tightening will correct the deformity and maintain a flexible foot. Arthrodesis is not recommended for a supple, correctable deformity because of loss of motion and long-term degeneration of surrounding joints. Medial displacement calcaneal osteotomy is generally reserved for an adult-acquired flexible flatfoot. REFERENCES: Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 613-631. Evans D: Calcaneo-valgus deformity. J Bone Joint Surg Br 1975;57:270-278. Mosca VS: Calcaneal lengthening for valgus deformity of the hindfoot: Results in children who had severe, symptomatic flatfoot and skewfoot. J Bone Joint Surg Am 1995;77:500-512.

DISCUSSION: The artery of the tarsal canal is a branch of the posterior tibial artery. Among the branches of the artery of the tarsal canal is the deltoid artery. This arterial complex supplies the medial one third of the talar body. Disruption of this artery may lead to osteonecrosis of the medial body and subsequent collapse into varus. This is most commonly seen with talar body fractures but may be seen in Hawkins type 3 talar neck fractures. The artery of the tarsal sinus arises from the dorsalis pedis, lateral malleolar, and perforating peroneal arteries. The peroneal artery anastomoses with the calcaneal branches of the posterior tibial artery to form a plexus of vessels that supplies the posterior tubercle of the talus. Disruption of this artery would not result in collapse of the medial body, and thus would not lead to a varus deformity. REFERENCES: Halibruton RA, Sullivan CR, Kelly PJ, et al: The extra-osseous and intra-osseous blood supply of the talus. J Bone Joint Surg Am 1958;40:1115. Mulfinger GL, Trueta J: The blood supply of the talus. J Bone Joint Surg Br 1970;52:160-167.

DISCUSSION: In the presence of a supination external rotation-type fracture of the distal fibula (Weber type B), stability of the ankle is best assessed by performing an external rotation stress AP view of the ankle. This test is used to assess the integrity of the deltoid ligament. The presence of a deltoid ligament rupture results in instability and generally is best managed surgically. The gravity stress test can also be used. REFERENCES: Egol KA, Amirtharajah M, Tejwani NC, et al: Ankle stress test for predicting the need for surgical fixation of isolated fibular fractures. J Bone Joint Surg Am 2004;86:2393-2398. McConnell T, Creevy W, Tornetta P III: Stress examination of supination external rotation-type fibular fractures. J Bone Joint Surg Am 2004;86:2171-2178. Schock HJ, Pinzur M, Manion L, et al: The use of the gravity or manual-stress radiographs in the assessment of supination-external rotation fractures of the ankle. J Bone Joint Surg Br 2007;89:1055-1059.

DISCUSSION: A Hawkins III fracture-dislocation generally presents with posteromedial displacement with the deltoid ligament intact. Therefore, the only remaining blood supply is the deltoid branch of the artery of the tarsal canal originating from the posterior tibial artery. Often, the medial malleolus is fractured, assisting in reduction and visualization of fracture reduction. If the medial malleolus is intact, a medial malleolus osteotomy allows visualization of the reduction without compromising the last remaining blood supply to the talus. REFERENCES: Mulfinger GL, Trueta J: The blood supply of the talus. J Bone Joint Surg Br 1970;52:160-167. Vallier HA, Nork SE, Barei DP, et al: Talar neck fractures: Results and outcomes. J Bone Joint Surg Am 2004;86:1616-1624.

DISCUSSION: An os trigonum is usually asymptomatic, but this accessory bone has been associated with persistent posterior ankle pain, which has been described as os trigonum syndrome. This usually affects athletes and ballerinas. Forced plantar flexion leads to impingement of the os trigonum against the posterior tibial plafond, and flexor hallucis tendinitis may develop. Steroid injections may lead to tendon rupture. The results of excision of a symptomatic os trigonum through a posteromedial or lateral approach are favorable, with a rapid return to full function. REFERENCES: Hedrick MR, McBryde AM: Posterior ankle impingement. Foot Ankle Int 1994;15:2-8. Abramowitz Y, Wollstein R, Barzilay Y, et al: Outcome of resection of a symptomatic os trigonum. J Bone Joint Surg Am 2003;85:1051-1057.

The inferior tibiofibular syndesmosis is a fibrous articulation consisting of four ligaments; the elasticity of these ligaments permits axial, vertical, anterior, posterior, and mediolateral motion at the ankle syndesmosis during weight bearing. Nielson et al reported that the level of the fibular fracture does not correlate reliably with the integrity or extent of the interosseous membrane (IOM) tears identified on MRI in operative ankle fractures. Therefore, one cannot consistently estimate the integrity of the IOM and subsequent need for transsyndesmotic fixation based solely on the level of the fibular fracture. This supports the need for intraoperative stress testing (i.e., external rotation stress or Cotton test) of the ankle syndesmosis in all operative ankle fractures. The study by Leeds et al noted a correlation between syndesmosis reduction (initial and final) and outcomes (radiographic and clinical). Of note, the Cotton test was originally described around 1910 by Frederic J. Cotton as the "talar glide test" evaluating the medial/lateral translation of the talus in the mortise. A positive result, indicating disruption of the deltoid ligament or ankle syndesmosis, was defined as translation of greater than 1 mm.

Because the patient has sustained a tarsometatarsal injury with midfoot sag, the treatment of choice is a tarsometatarsal arthrodesis. The cause of his flatfoot deformity is secondary to the tarsometatarsal injury and not from posterior tibialis tendon deficiency. Lateral column lengthening, double arthrodesis, and calcaneal osteotomy are not indicated. Although open reduction and internal fixation may be performed late when arthritis is present, these procedures are less likely to succeed.

Weil osteotomies are useful in achieving shortening of a lesser metatarsal with preservation of the distal articular surface. The osteotomy is oriented from distal-dorsal to proximal-plantar; therefore, proximal displacement of the distal fragment is associated with plantar (not dorsal) displacement as well. Plantar displacement can result in the intrinsics acting dorsal to the center of the metatarsophalangeal joint and the development of an extended or “floating toe.” Nonunion, osteonecrosis, and inadequate shortening are infrequent complications associated with the Weil lesser metatarsal osteotomy.

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.