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AOAO BOARD REVIEW FOOT/ANKLE SECTION
2020
William E. Saar, D.O.
TriRivers Musculoskeletal Centers – UPMC
Faculty – UPMC Foot/Ankle Fellowship Program
Common Ft/Ankle Topics Covered
• Posterior Tibial Tendon Dysfunction
• Hallux Valgus
• Diabetic Foot Disorders
• Trauma
• Hallux Rigidus / Arthritis
• Talar (OLT) Lesions
• Achilles Conditions
• Lesser Toe Deformities
• Foot/Ankle Biomechanics-Gait
Posterior Tibial Tendon Dysfunction
• Etiology
• Early (Hypovascularity)
• Late (Primary dynamic support lost)
• Female:Male (3:1); Avg. Age 50-60
• Presentation/Exam/Studies
• “Too many toes” Sign (Forefoot abduction)
• Hindfoot valgus (Rigid/Flexible)
• Single heel rise pain/inability
• Xray
• Lateral Talo-1st MT Angle (Meary) – TN ‘Sag’
• AP – Talar Head Uncoverage
Posterior Tibial Tendon Dysfunction
Posterior Tibial Tendon Dysfunction
Hallux Valgus Deformity
• Pathoanatomy
– Plantarlateral of AbH pronates Phalanx
– Lateral Deviation of EHL/FHL causes valgus progression/pronation
– 1st MT Head moves medially off sesamoids
– Lateral Capsular contracture / Medial Capsular attenuation
• Radiographic Features/Measurements
– HVA / IMA / HVI / DMAA (Congruency??)
• Treatment
– Based on: 1) Angular Measurements; and 2) Clinical Scenario
Hallux Valgus Deformity
Hallux Valgus Deformity
Diabetic Foot Disorders
• Pathoanatomy
– Neuropathy
• SW 5.07 Monofilament depicts protective sensation
• Motor neuropathy MC involves Common Peroneal Nerve – Tib Ant
weakness and Footdrop
– Angiopathy (Healing potential reduced with)
• Total Protein < 6 g/dL
• Total Lymphocytes (WBC) < 1,500
• Albumin Level < 2.5 g/dL
• TCOM < 40 mmHg
• Absolute Toe Pressure < 40
• ABI < 0.5
Diabetic Foot Disorders
• Diabetic Wound Classification (Wagner)
• If Ulcer probes to bone, 67% chance of osteomyelitis (often polymicrobial)
– Equinus Contracture / Level of Amputation
Diabetic Foot Disorders (Charcot)
• Neurotraumatic: Repetitive microtrauma due to lack of protective sensation
• Neurovascular: Autonomic dysfunction increasing blood flow leading to bone resorption and weakening
Diabetic Foot Disorders (Charcot)
• Charcot Classification (Eichenholtz)
Foot/Ankle Trauma – Calcaneus Fracture
• Intra-articular
– Sanders Classification - based on fx pattern through posterior facet
– Lateral wall blowout – subfibular impingement and peronealtendon encroachment
– Indications: facet displacment >2-3mm; Bohler’s angle flattening; tuberosity varus
– Improved Surgical Clinical Outcomes: Age<29; women; non WC cases; significant displacement and flatter Bohler’s angle
• Extra-articular
– Tongue type fracture: displacement places posterior soft tissue at risk; requires urgent reduction/fixation
Foot/Ankle Trauma – Talus Fractures
• Blood Supply
– Provided by: posterior tibial, dorsalis pedis, and perforating peroneal;
artery of tarsal canal-talar body
• Hawkins Classification (see next slide)
• Radiographic Signs
– Hawkins Sign: Subchondral linear lucency of talar dome (indicative of talar
revascularization)
– Sclerosis: Does NOT guarantee that AVN has occurred, but it is suggestive
– Canale View
• Lateral Talar Process (Snowboarder’s Fracture)
Foot/AnkleTrauma – Talus Fractures
• Hawkins Classification
Foot/Ankle Trauma – Lisfranc Injury
• Second MT base is ‘keystone’ of arch
• Ligament b/w medial cuneiform and 2nd MT Base
• Weightbearing views; Evaluate for ‘Fleck Sign’
– Know anatomic landmarks
• Treatment
– Nonsurgical for nondisplaced injuries
– Surgical: Anatomic ORIF vs Primary Arthrodesis
• Based on extent of ligamentous / bony injury (comminution)
Foot/Ankle Trauma – Lisfranc Injury
Foot/Ankle Trauma – 5th MT Fractures
Foot/Ankle Trauma – 5th MT Fractures
• Treatment
– Conservative: Immobilization; NWB (Zone 2)
– Surgical: ORIF (Intramedullary/Plate-Screw)
Arthritis – Hallux Rigidus
• Pathoanatomy: Unknown; Anatomic/Genetic Predisposition, and Repetitive Trauma• Grading
Treatment
Grade 0/1: NSAIDs; Activity Mod.; Orthotic (Morton’s Ext)
Grade ½: Dorsal Cheilectomy
Grade ¾: Arthrodesis (vs. Arthroplasty)
Arthritis – Tibiotalar
• Mostly Post-traumatic in origin
• Commonly results from non-anatomic fracture healing – altering
joint contact forces and load bearing
• Tibiotalar (Ankle) Arthrodesis
– Reliable relief of pain: Young laborers/less active elderly
patients
– Up to 50% subtalar arthritis at 10 year F/U
– Position: Neutral DF (90°); 0-5° Valgus; 5-10° Ext Rotn
Arthritis – Ankle Replacement
• Indicated in posttraumatic, elderly, inflammatory arthritis
• Contraindications: Bone Loss, Severe Deformity, AVN, Obesity, Infection, Charcot, Instability
• TAA has shown the best outcome in patients with Osteoarthritis
Talar (OLT) Lesions
• Lateral Lesions
– Traumatic; often symptomatic/displaced
– More anterior/central; usually shallow/wafer shaped
• Medial Lesions
– More common; Atraumatic
– Larger; More posterior; Cup shaped and deeper
• Treatment
– Nondisplaced/Incomplete: Protected WB Cast x 6 weeks
– < 1 cm.: Arthroscopic removal with/without microfracture
– > 1 cm. with intact cap: Retrograde Drilling
– >0.5 cm. and displaced: ORIF vs. OATS vs. Restorative Procedures
Talar (OLT) Lesions
Achilles Conditions
• Non-insertional Tendonitis/Tendinopathy
– Pathophysiology: Abnormal vascularity 2-6 cm. proximal
to insertion with overuse, microscopic tearing of tendon
• Treatment
– Activity modification; Heel Lifts; NSAIDs; PT
– Open Excision with tubularization/repair
• Tendon Transfter (>50% degeneration)
Achilles Conditions
• Insertional Tendonitis (Haglunds/Spur/RC Bursitis)
Pathophysiology: Repetitive trauma and insertional/bursal inflammation
– Treatment
• Activity Modification; Heel Lifts; NSAIDs; PT
• U/S Guided Bursal Injection
• Sx – Bursal Excision / Resection Haglunds-Spur / Tendon Augmentation (FHL) if
> 50% degeneration
Achilles Conditions
• Achilles Rupture– Risk Factors: Weekend warriors, Fluoroquinolones, Steroid
Injections
– Eccentric Achilles contraction with rupture 4-6 cm above insertion
– Treatment• Non-Op: Functional Rehab; Decreased Op Complications;
Possible Increased Re-rupture• Open Repair• Percutaneous Repair: Less wound issues; Sural Neuropraxia• Reconstruction with V-Y Advancement for defects 2-5 cm.
with/without FHL Transfer
Lesser Toe Deformities
• Pathoanatomy: Typically results from tendon imbalance, resulting in synovitis and MTP pain due to deformity
Lesser Toe Deformities
• Treatment
– Non-operative: Shoe modification (Wide/Deep Toe Box);
Foam/Silicone Sleeves; Budin Splints
– Operative
• Tendon Transfers (usually FDL to EDL)
• Tenotomies
• PIP Joint Resection/Fusion for rigid deformities
(High rate of nonunion)
• Osteotomies (Weil, etc…)
Lesser Toe Deformities
Biomechanics/Gait• Hindfoot
– Subtalar joint responsible for inversion/eversion
– Transverse Tarsal Joints (TN/CC)
• Inversion LOCKS the TT Joints in toe off
• Eversion UNLOCKS the TT Joints to accommodate heel strike
• Midfoot (Naviculocuneiform and TMT Joints)
– 3 Columns: Medial; Middle (Keystone); Lateral (flexible)
– Ligamentous Support: Interosseous (Lisfranc); Plantar; Dorsal
• Forefoot
– Transverse MT Ligament holds Hallux sesamoids in place
– Plantar Plates: Weakest at MT Neck origin, when attenuated can be deformed by EDL and increase dorsal translation of Proximal Phalanx
Biomechanics/Gait
• Windlass Mechanism: Tightening of the Plantar Fascia (medial calcaneal tuberosity to MT bases) during toe off to increase arch height/support