Foot and Ankle Problems

Educational Objectives

The goal of this program is to improve the management of traumatic and degenerative problems of the foot and ankle. After hearing and assimilating this program, the clinician will be better able to:

1.   Evaluate ankle sprains during a clinical examination.

2.   Provide rehabilitation to patients exhibiting lingering complications related to ankle injuries.

3.   Assess injuries to the forefoot.

4.   Recognize and prevent compartment syndrome in patients with significant orthopedic trauma.

5.   Discuss ankle replacement as an alternative to fusion in patients with deteriorated ankle joints.

Faculty Disclosure

In adherence to ACCME Standards for Commercial Support, Audio-Digest requires all faculty and members of the plan­ning committee to disclose relevant financial relationships within the past 12 months that might create any personal con­flicts of interest. Any identified conflicts were resolved to ensure that this educational activity promotes quality in health care and not a proprietary business or commercial interest. The following has been disclosed: Dr. Easley is a consultant and has received fellowship support from Wright Medical, and is a consultant for Small Bone Innovations. Drs. Russell and Alexander and the planning committee reported nothing to disclose.

Acknowledgments

The speakers were recorded at 9th Annual Canadian Orthopaedic Foot and Ankle Symposium, held April 25-26, 2009, in Calgary, AB, and sponsored by the Division of Orthopaedic Surgery, Department of Surgery, University of Calgary. The Audio-Digest Foundation thanks the speakers and the sponsors for their cooperation in the production of this program.

Ankle Sprain: Diagnosis and Management

Iain S. Russell, MD, Clinical Assistant Professor, Division of Orthopaedic Surgery, Department of Surgery, University of Calgary, AB

Background on ankle sprains: large percentage of patients develop residual pain; several high-quality studies show proprioceptive measures (eg, training on wobble board to boost cognitive awareness of foot orientation) and ever­sion strengthening significantly decrease incidence of lateral ankle injury; inversion injuries with axial loads

Examination: ability to walk immediately after injury often indicates degree of severity; ask patient about time until onset of swelling; even during first 24 hr, locating source of greatest pain can identify damaged anatomic struc­tures; palpate over fibula to rule out fracture; evaluate anterior and inferior aspects of fibula (ligaments) and poste­rior fibula (possible site of damage to peroneal tendons or peroneal retinacula); focus on anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL); ATFL tears first, as it bears most of varus stress during plan­tar flexion; simple surface anatomy  —  locate and palpate sinus tarsi; evaluate base of fifth metatarsal and insertion of peroneus brevis for fracture; calcaneocuboid joint (identifiable in majority of patients) should be compared to opposite side and evaluated for tenderness; anterior ankle joint line  —locate tip of medial malleolus; joint line lo­cated 1 cm up and 1 cm anterior (medial to tibialis anterior); obscured by extensor tendons; best space for aspira­tion of ankle joint; palpate back of ankle joint; Achilles tendon  —  missed ruptures lead to difficult recoveries; examination difficult, especially after 24 hr (due to swelling); ultrasonography (US) definitively diagnoses rup­tures; stress testing in acute setting  —  not recommended by speaker due to patient discomfort; associated complications  —  syndesmotic injury; peroneal tendon or retinacular injury; fracture; stress radiographs  —  not helpful in acute setting; useful with chronic injuries; magnetic resonance imaging (MRI) excellent but cost often prohibitive

Treatment: protection, rest, ice, compression, and elevation; short-term immobilization acceptable for severe sprains (eg, cast before weightbearing possible, crutches as necessary); early movement and range-of-motion (ROM) exer­cises important; apply progressive weightbearing; rehabilitation  —  takes 2 wk to 6 mo; stiff joints and weak mus­cles may have developed; training with wobble boards and eversion strengthening prevents future injuries; reevaluation critical

Chronic pain and instability: patients often receive inadequate rehabilitation after injury to CFL and ATFL; routine MRIs do not provide comprehensive diagnosis; ensure patients see physical therapist for ROM exercise, control of swelling, and proprioception and strength training; functional instability  —  common development in patients with severe or recurrent injury; presents as lapsed ligament with gross instability during examination; question patients about anxiety and ankle rolling occurring regularly during normal activity; intra-articular pathology  —  eg, osteo­chondral lesion; causes chronic problems after ankle sprain; other considerations  —  injuries to syndesmosis; ankle impingement; tendon problems; stress fractures; arthritides; nerve injuries; evaluation  —  ask questions to differenti­ate functional instability from pain; repeat examination; point of maximal tenderness key; put patients through ROM (active and passive); perform functional evaluation (eg, getting patients to hop, walk, squat); radiography  —  bone scan highly sensitive, but not specific; MRIs highly useful (include instructions for radiologist with orders); indications for surgical referral  —  failure during initial assessment; failure to recover after adequate rehabilitation; intra-articular pathology; osteochondral injury; genuine functional instability; help offered when patients limit ac­tivities; instability  —  occurs in £40% of patients suffering ankle sprains; anxiety over instability often troubles pa­tients after recovery; obtain stress x-rays, varus stress, anteroposterior (AP) or anterior drawer lateral stress view, or MRI; surgical reconstruction for instability  —  examine surface of joint endoscopically (look for intra-articular pa­thology); reconstruct ATFL and CFL (often present as condensations within joint capsule rather than discrete ropes) flattened ligaments cut and reattached, becoming twice as thick and half as long; speaker’s technique  —  lift up extensor retinaculum during approach to lateral side; take down capsule by cutting through ATFL and CFL on anterior-inferior portion of fibula; divide both; elevate flap off bone; roughen surfaces (bleeding theoretically pro­motes healing); place suture anchors; bring inferior flap up to bone, then lay other half on top; patients splinted 2 wk after procedure; movement encouraged after 2 wk; some patients require 6 wk in cast with feather weightbear­ing; high patient satisfaction rates reported

Forefoot Trauma

Pradeep Alexander, MD, Active Staff, Orthopaedic Surgeon, William Osler Health Care Center, Brampton Civic Hospital, Brampton, ON

Metatarsal fractures: in patients with metatarsal base injury, Lisfranc joint complex requires close scrutiny; shaft fractures  —  often overlooked in patients with polytrauma; typically found on routine x-rays and treated with cast or fracture boot and no weightbearing for 4 to 6 wk; lesser metatarsals  —  ie, second to fifth; patients with fractures but no gross displacement (typically in sagittal plane) treated nonoperatively; first metatarsal  —  anatomy critical to function of forefoot; injuries intolerant of malalignment or displacement; greater indication for surgery (malunion may lead to painful transfer lesions of lesser metatarsal heads); platable on dorsal surface or medial side; stress fractures  —loads directed toward metatarsal shaft may cause microfractures; often found on x-rays (periosteal re­action visible), bone scans, computed tomography (CT), or MRI; rarely treated surgically (rest or immobilization recommended); metatarsal neck fractures  —  associated with high-energy injuries; usually multiple and displaced; malunion creates metatarsalgia due to pressure between metatarsal heads and plantar surfaces (may promote cal­luses); reduced under general anesthetic; speaker’s repair technique  —  make small dorsal incision over metatarsal neck; push K-wire through joint to proximal phalanx; back wire out in retrograde (holds toe in reduction); avoid ex­cessive plantar wiring (leaves joint in hyperextension); metatarsal head fractures  —  typically result from direct trauma; treatment with closed reduction and percutaneous pinning may promote stiffness and arthritis

Metatarsophalangeal (MTP) joint dislocation and “turf toe”: due to repetitive loading of first MTP, which causes stretching of capsule; closed reduction impossible when plantar plate becomes interposed with sesamoids above metatarsal head (requires dorsal incision to release plate and sesamoids underneath head); lesser MTPs  —  ³40 de­grees of extension required for walking; dorsal incision to divide plantar plate necessary if irreducible

Forefoot injuries: zone 1 injuries  —  similar to avulsion; lateral band of plantar aponeurosis (sometimes with pero­neus brevis) pull tuberosity of fifth metatarsal; rule out os peroneum (ossification) by assessing smoothness of frac­ture edges; injuries often minimally displaced and stable; strong blood supply allows healing in 6 to 8 wk with nonoperative measures (eg, hard-soled shoe, walking cast); zone 2 injuries  —true Jones fractures; can present as stress or acute fractures; area between junction of metaphysis and diaphysis of bone; patients who report preexist­ing symptoms (eg, regional pain) often receive treatment as for zone 3 injury; acute injuries in zone 2 typically treated nonoperatively (eg, cast, fracture boot for 8-10 wk with weightbearing); zone 3 injuries  —  occur within proximal 1.5 cm of diaphyseal shaft; due to stress fractures from repetitive loads; fracture propagates laterally to­ward medial side; unlikely to heal without intervention due to poor blood supply; nutrient artery likely injured; ex­tended nonweightbearing period recommended (»3 mo); open reduction and internal fixation with bone graft indicated in patients with nonunion; distal spiral (dancers’) fractures  —  spiral oblique fractures typically caused by rotational force applied to foot in axial-loaded plantar-flexed position; blood supply typically intact (allows healing without intervention)

Phalangeal fractures: most often occur in proximal phalanx of fifth toe; rarely surgical; symptomatic management (eg, buddy taping) recommended; displaced fractures may be reduced with digital block and buddy taping; lesser toe fractures  —  typically given supportive treatment; closed reduction with ring block occasionally required; mal­union may require removal of any bony prominences causing pressure; sesamoid bone  —  critical to weightbearing; tibial sesamoid at greatest risk for fracture; activity exacerbates pain; easily identified on x-rays; conservative treat­ment advocated for 6 wk (ie, nonweightbearing with stiff shoe); chronic pain alleviated by medial approach to re­move tibial sesamoid in place without injuring flexor hallucis brevis tendon (injury removal of both or injury to tendon may create “cock-up” toe deformity); open fractures  —  aggressive irrigation and debridement recom­mended; antibiotic coverage varies based on severity; assess for tetanus; removal of contamination may require multiple operations with serial debridement; bony stabilization and possibly early skin grafting utilized

Other injuries: crush injuries  —  determining neurovascular status critical; aggressive debridement required; main­tain weightbearing in all metatarsal heads; crushing may cause compartment syndrome up to 36 hr after initial in­jury (suspect in patients with disproportionate pain); compartment syndrome  —  diagnosed when pressure in compartment within 30 mm Hg of diastolic blood pressure; often diagnosed clinically (pain on passive stretching of muscle belly); measuring of compartments required only if patient obtunded or has serious injuries; fasciotomy rec­ommended with even slight suspicion; fasciotomy  —  incisions made over second and fourth metatarsal, leaving suf­ficient skin to prevent sloughing and allow decompression of all 4 intrinsic compartments; medial incision made from tip of medial malleolus down toward base of first metatarsal allows opening of fascia over abductor hallucis and medial intermuscular septum

Update on Ankle Arthritis

Mark E. Easley, MD, Assistant Professor, Department of Surgery, Division of Orthopaedic Surgery, Duke Uni­versity Medical Center, Durham, NC

In-bone prosthesis: replacements approved in United States utilize fixed bearings (movable structures possibly supe­rior); intramedullary ankle replacement  —  constructed from within joint; highly adjustable stem size (allows place­ment of additional support); foot frame allows intramedullary alignment; procedure requires significant fluoroscopy (radiation protection necessary); intramedullary guide passes through subtalar joint (single hole in front of articular surface); Agility LP Total Ankle Replacement  —cutting block used to resect joint after alignment (substantial amount of bone removed); prosthesis constructed within area of removal; deformity  —  ankles not al­ways straight (may lead to arthritis or deformity); use of laminar spreaders and prosthetics allows replacement of ankles previously only eligible for arthrodesis

Ankle arthrodesis: still taught as gold standard; ankle replacement widely regarded as investigational or experimen­tal (insurers often dispute coverage); higher rates of reoperation seen after replacement; however, arthrodesis asso­ciated with long-term development of arthritis in subtalar joint; hindfoot  —  compensates for fused ankle; in 22-yr follow-up of 23 successful ankle arthrodesis procedures, many patients showed deterioration of hindfoot and func­tional limitations

Ankle replacement: Agility LP Total Ankle Replacement  —talar component may settle down into talar bone, creating long-term complications; suitable for long-term implantation with proper support; anatomic total ankle replace­ment (Salto Talaris)  —  utilized in ankles with minimal deformity; features movable plastic bearing; Scandinavian total ankle replacement (STAR)  —  associated with poorer outcomes in patients with unfavorable coronal plane anatomy (eg, incongruent alignment); alignment critical in ankle repair; arthritis and ankle replacement  —  speaker recommends medial release of soft-tissues before replacement; superficial fibers of deltoid ligament left intact as sleeve (deep fibers released); intact sleeve allows use of contracture in ankle alignment; cutting block placed in ref­erence to intramedullary alignment may offer advantages; tibial component assembled inside joint; medial release utilized due to relative looseness of lateral tissues; painful ankle arthritis  —  seen in patients with ankle arthrodesis; associated with stress in rear of foot; anesthetization of subtalar joint region relieves pain; tibiotalocalcaneal arthrodesis  —  fusion of entire hindfoot; associated with poor functional status; taking down arthrodesis  —  guide pins inserted for protection of malleolae; fused ankle cut out and new ankle created; in younger patients ineligible for ankle replacement, speaker recommends preserving anatomy (eg, fibula) during arthrodesis

Fixation: proper preparation of joint surfaces required with internal or external fixation; rigid internal fixation  —compresses surfaces together; allows only minimal adjustment and repair after procedure; Ilizarov external fixator frame  —  speaker recommends in place of cast for patients with deformity and poor bone quality; fixators utilizing computerized adjustments allows greater flexibility and inexact alignment; external fixation  —  may promote heal­ing in patients with poor bone quality undergoing revision ankle arthrodesis; allows progressive tightening and compression over successive clinic visits; complex external fixation frame  —  fixation of talus and foot preserves and prevents stress to subtalar joint; compression of subtalar joint may damage cartilage

Distraction arthroplasty: ankle distracted into highly symmetric Ilizarov frame with thin wires; hinged frame  —  wire placed through talus for support; external fixation plus confinement of hinging to Inman’s axis of ankle joint prevents talus from walking out of ankle mortise; speaker’s technique  —  clean up joint area (eg, remove bone spurs); loosening of hinges and placement of extra struts (in clinic) prevents frame from breaking and allows rapid return to mobility; frame removal  —  joint appears collapsed after removal; scar tissue may fill in and create interpo­sitional arthroplast; significant arthritis in front of ankle may increase failure rates; talar avascular necrosis (AVN)  —  subtalar arthrodesis possible if subtalar joint fuses underneath

Suggested Reading

Cracchiolo A 3rd, Deorio JK: Design features of current total ankle replacements: implants and instrumentation. J Am Acad Orthop Surg 16:530, 2008; Culpan P et al: Arthrodesis after failed total ankle replacement. J Bone Joint Surg Br 89:1178, 2007; Henning JA et al: Open reduction internal fixation versus primary arthrodesis for lisfranc injuries: a pro­spective randomized study. Foot Ankle Int 30:913, 2009; Kim C et al: Tibiotalocalcaneal arthrodesis for salvage of severe ankle degeneration. Clin Podiatr Med Surg 26:283, 2009; Mandracchia VJ et al: Fractures of the forefoot. Clin Podiatr Med Surg 23:283, 2006; McCormick JJ, Anderson RB: The great toe: failed turf toe, chronic turf toe, and complicated sesamoid injuries. Foot Ankle Clin 14:135, 2009; Mohammadi F: Comparison of 3 preventive methods to reduce the recur­rence of ankle inversion sprains in male soccer players. Am J Sports Med 35:922, 2007; O’Loughlin PF et al: Ankle insta­bility in sports. Phys Sportsmed 37:93, 2009; Pollak AN et al: The relationship between time to surgical debridement and incidence of infection after open high-energy lower extremity trauma. J Bone Joint Surg Am 92:7, 2010; Raikin Sm, Mys­erson MS: Avoiding and managing complications of the Agility Total Ankle Replacement system. Orthopaedics 29:930, 2006; Santos MJ, Liu W: Possible factors related to functional ankle instability. J Orthop Sports Phys Ther 38:150, 2008; Valderrabano V et al: Etiology of ankle osteoarthitis. Clin Orthop Relat Res 457:1800, 2009.