Foot and Ankle



Foot and Ankle


Nigel N. Hsu

Casey Jo Humbyrd



ANATOMY



  • Ligaments



    • Lateral



      • Anterior talofibular ligament (ATFL)


      • Calcaneofibular ligament (CFL)


      • Posterior talofibular ligament


      • Syndesmosis



        • Anterior inferior tibiofibular ligament (AITFL)—35% of strength


        • Posterior inferior tibiofibular ligament (PITFL)—40% of strength


        • Interosseous ligament—21% of strength


    • Medial



      • Deltoid ligament complex


      • Calcaneonavicular ligament


  • Windlass mechanism



    • Plantar fascia tightens as the metatarsophalangeal (MTP) joints extend and lock the tarsal bones into a rigid column.


  • Gait mechanics



    • Stance phase



      • Heel strike



        • Hindfoot eversion unlocks the transverse tarsal joints for shock absorption.


        • Tibialis anterior—eccentric contraction


      • Foot flat



        • Gastrocnemius-soleus complex—eccentric contraction


      • Midstance



        • Hip extensors and quadriceps—concentric contraction


      • Heel off



        • Hip flexors—concentric contraction


    • Swing phase



      • Toe off



        • Hindfoot inversion locks the transverse tarsal joints for rigid lever arm.


        • Gastrocnemius-soleus complex—concentric contraction


      • Midswing



        • Tibialis anterior—concentric contraction


      • Terminal swing



        • Hamstring—decelerate


FOREFOOT


Hallux Valgus



  • Definition



    • Valgus deviation of the great toe with varus deviation of the first metatarsal (MT)


  • Patient history



    • More common in women


    • Pain over medial eminence


    • Difficulty with footwear


  • Physical examination



    • Hallux—valgus and pronation


  • Imaging (Figure 8.1)



    • Hallux valgus angle (HVA) <15°







      Figure 8.1 Hallux valgus. From Walker R, Hamilton P, Singh S. Scarf osteotomy. In: Easley ME, ed. Operative Techniques in Foot and Ankle Surgery. 2nd ed. Philadelphia, PA: Wolters Kluwer; 2017:41-50.


    • Intermetatarsal angle (IMA) <9°


    • Distal metatarsal articular angle (DMAA) <15°


    • Hallux valgus interphalangeus angle (HVI) <10°


    • Access congruency of the first MTP


  • Treatment



    • Soft-tissue release (modified McBride procedure)


    • First MTP fusion—first MTP joint arthritis


    • Lapidus (first tarsometatarsal [TMT] joint fusion)—instability of first TMT joint


    • Distal chevron osteotomy—IMA <13° and HVA <40°


    • Proximal osteotomy—IMA ≥13° and HVA ≥40°


    • Biplanar osteotomy—to correct a DMAA >15°; may also need a proximal osteotomy


    • Akin osteotomy (proximal phalanx medial closing wedge osteotomy)—HVI >10°


  • Hallux rigidus



    • Definition—first MTP arthritis and stiffness


    • History—pain and swelling of the first MTP


    • Physical examination



      • Decreased dorsiflexion


      • Positive axial grind test


    • Imaging (Figure 8.2)



      • Grade 0—normal radiograph, stiffness on examination


      • Grade 1—mild dorsal osteophyte, mild pain on examination


      • Grade 2—moderate dorsal osteophyte, <50% joint space narrowing, moderate pain on examination







        Figure 8.2 Hallux rigidus. A, Grade 1: hallux rigidus. B, Grade 2: hallux rigidus. C, Grade 3: hallux rigidus. D, Lateral view of hallux rigidus. From San Giovanni TP. Arthrosurface hemiCAP resurfacing. In: Easley ME, ed. Operative Techniques in Foot and Ankle Surgery. 2nd ed. Philadelphia, PA: Wolters Kluwer; 2017:154-175.


      • Grade 3—severe dorsal osteophyte, >50% joint space narrowing, major stiffness, pain at extreme range of motion (ROM), no pain at midrange


      • Grade 4—severe dorsal osteophyte, >50% joint space narrowing, major stiffness, pain at extreme ROM, pain at midrange


    • Treatment



      • Nonoperative—Morton extension, that is, stiff foot plate with extension under great toe


      • Operative



        • Dorsal cheilectomy—grades 1 and 2


        • First MTP arthrodesis (fuse in 10°-15° of dorsiflexion)—grades 3 and 4


Lesser Toe Deformities



  • Hammer toe



    • Definition



      • Distal interphalangeal (DIP) joint extension


      • Proximal interphalangeal (PIP) joint flexion


      • MTP joint normal (slight extension)


    • Treatment



      • Nonoperative—footwear modification to high toe box


      • Operative



        • Flexible deformity



          • Flexor tenotomy


          • Flexor-to-extensor tendon transfer


        • Fixed deformity



          • PIP arthroplasty


          • PIP arthrodesis



  • Claw toe



    • Definition



      • DIP flexion


      • PIP flexion


      • MTP hyperextension


    • Treatment



      • Nonoperative—footwear modification to high toe box


      • Operative



        • Flexible deformity



          • Extensor digitorum brevis (EDB) tenotomy, extensor digitorum longus lengthening, flexor-to-extensor tendon transfer


        • Fixed deformity



          • PIP arthroplasty/arthrodesis, MTP joint capsulotomy, extensor lengthening


          • Shortening (Weil) osteotomy


  • Mallet toe



    • Definition



      • DIP flexion


      • PIP normal


      • MTP normal


    • Treatment



      • Nonoperative—footwear modification to high toe box


      • Operative



        • Flexible deformity—flexor tenotomy


        • Fixed deformity—DIP arthroplasty/arthrodesis


  • Crossover toe



    • Definition—second toe lies dorsomedially relative to hallux


    • Treatment



      • Nonoperative—toe taping/splint


      • Operative



        • Flexor-to-extensor tendon transfer, medial collateral ligament release


        • EDB transfer to the intermetatarsal ligament


        • Shortening (Weil) MT osteotomy


  • MTP dislocation



    • Definition



      • Multiplanar instability


      • Plantar plate disruption


      • Walk on “marble in the ball of the foot”


    • Treatment



      • Nonoperative—taping, footwear modification, MT pads


      • Operative



        • Weil osteotomy


        • Plantar plate repair


        • Flexor-to-extensor tendon transfer


        • EDB transfer to the intermetatarsal ligament


  • Bunionette



    • Definition



      • Bony prominence over lateral MT head



        • Type I—Enlarged fifth MT head or lateral exostosis


        • Type II—Congenital bow of fifth MT


        • Type III—Increased 4 to 5 IMA


    • Treatment



      • Nonoperative—footwear modification to wide-based shoes


      • Operative



        • Lateral condylectomy



        • Distal MT osteotomy


        • Oblique diaphyseal rotational osteotomy


Sesamoid Injuries



  • Turf toe



    • Definition



      • Forced dorsiflexion—avulsion of the plantar plate of the base of the phalanx and proximal migration of the sesamoids



        • Grade 1—capsular strain


        • Grade 2—partial capsular tear


        • Grade 3—complete plantar plate tear


    • Treatment



      • Nonoperative—stiff insole, toe taping


      • Operative—plantar plate repair


  • Sesamoid fracture



    • Boot immobilization


    • Transition to sesamoid relief pad


    • Surgery-excision versus open reduction and internal fixation (ORIF)


  • Sesamoiditis



    • Rest, ice, compression, and elevation


    • Footwear modification


Fifth MT Base Fracture



  • Zone 1—avulsion fracture (pseudo-Jones fracture)



    • Hindfoot inversion—peroneus brevis or plantar fascia


    • Protected weight bearing in shoe/boot


  • Zone 2—metaphyseal-diaphyseal junction, extend into fourth and fifth intermetatarsal articulation (Jones fracture)



    • Forefoot adduction


    • Nonweight bearing


    • Intramedullary screw fixation in elite athletes


  • Zone 3—proximal diaphysis fracture



    • Repetitive microtrauma


    • Vascular watershed region


    • Increased risk of nonunion


    • Nonweight bearing


    • Intramedullary screw fixation with sclerosis/nonunion or athletes


MIDFOOT


Lisfranc Injury



  • Definition



    • TMT fracture/dislocation


    • Lisfranc ligament—medial cuneiform to base of second MT; plantar ligament


  • History



    • Axial loading of a plantar-flexed foot


    • Sports injuries


    • Motor vehicle accident


  • Physical examination



    • Severe pain and swelling


    • Plantar ecchymosis







      Figure 8.3 Lisfranc injury. Isolated disruption of second tarsometatarsal joint. From Early JS, Kitaoka HB, Campbell JT. Tarsometatarsal (Lisfranc) reduction and fixation. In: Kitaoka HB, ed. Master Techniques in Orthopaedic Surgery: The Foot and Ankle. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2013:229-248.


  • Imaging (Figure 8.3)



    • Widened gap between first and second MTs


    • Fleck sign—first intermetatarsal space


    • Weight-bearing view


    • Abduction stress view


  • Treatment



    • Nonoperative—cast immobilization for 8 weeks until no displacement on weight bearing or stress views


    • Operative



      • ORIF


      • Primary arthrodesis



        • Purely ligamentous injury


        • Intra-articular comminution


Midfoot Arthritis

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Dec 19, 2019 | Posted by in ORTHOPEDIC | Comments Off on Foot and Ankle

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