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



  • Definition—arthritis of the naviculocuneiform, intercuneiform, or MT cuneiform joint


  • History—midfoot pain with push-off


  • Physical examination



    • Arch collapse


    • Midfoot collapse


    • Tenderness to palpation in midfoot


  • Imaging (Figure 8.4)



    • Meary angle


    • Longitudinal arch collapse


    • Loss of joint space







      Figure 8.4 Jones Fracture (A) Midfoot. (B) Pseudo-Jones. (C) Oblique radiograph obtained at 8-month follow-up after open reduction and internal fixation (ORIF) (A) from Chou L B. Orthopaedic Knowledge Update. Wolters Kluwer, 2020. (B) From Sherman SC, Ross C, Nordquist E, Wang E, Cico S. Atlas of Clinical Emergency Medicine. Wolters Kluwer 2015. (C) Flatow E, Colvin AC, Atlas of Essential Orthopaedic Procedures 2ed. Wolters Kluwer 2019.


  • Treatment

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

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