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Duke Orthopaedics
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Wheeless' Textbook of Orthopaedics

Metatarsalgia


- Discussion:
    - in the normal foot, metatarsal heads bear one half of a person's body wt, when the foot is plantigrade;
           - the first metatarsal normally bears half the wt of the forefoot;
    - long 2nd metatarsal can contribute to pressure under metatarsal head;
    - limitation of dorsiflexion (from heel cord contracture or ankle impingement can contribute to diffuse metatarsalgia;
    - claw toe deformities will concentrate wt bearing on metatarsal heads;
    - hallux valgus:
           - as proximal phalanx moves into valgus, and the splay between first and second metatarsals increases, the first metatarsal base at first cuneiform-first
                   metatarsal joint also moves into varus and elevates creating in many  instances, less wt bearing than normal on 1st metatarsal head relative to the 2nd;
           - this set up a potential transfer lesion to the adjacent head;
           - hypermobility of the first MTC joint may also contribute to transfer metatarsalgia;
    - sesamoids:
           - tibial sesamoid normally assumes most of the wt bearing fx transmitted to the head of the first metatarsal;
           - because the sesamoids are eembedded in teh tendon of the FHB, which inserts into the base of the proximal phalanx, any degree of hallux valgus
                   tends to rotate both sesamoids on the long axis;
           - fibular sesamoid tends to rotate into the 1st metatarsal interspace, thereby disposing of the possibility of its becoming a wt bearing focus;



- Differential diagnosis:
    - injury / degenerative changes w/ resultant arthritis (hallucis rigidus)
    - morton's neuroma
          - pain in the metatarsal head may be caused by perineural fibrosis of intermetatarsal plantar digital nerves (Morton's neuroma);
    - sesamoids:
          - w/ hallux valgus, sesamoids may be displaced laterally;
          - frx of sesamoids are infrequent and must be distinguished from bipartite sesamoids;
    - loss of metatarsal fat pad;
    - metatarsal stress frx;
    - verruca plantaris
    - abnormally long 2nd metatarsal;
          - unless the foot is free to deviate laterally, the second metatarsal takes an undue share of the body wt at push off;
          - absolute weakness of intrinsic muscles may also concentrate body wt on 2nd metatarsal due to decreased ability to depress adequately
                   more mobile metatarsals;
                   - note how the 2nd metatarsal is wedged between the three cuniform bones, making it relatively immobile in relation to the midfoot;
          - insufficient supination of the forefoot at push off because of functional abnormality of the mid foot and hindfoot;


- Exam:
    - note amount of ankle dorsiflexion;
    - look for plantar keratosis and other skin changes;
    - deformities of lesser toes (and their flexibility);
    - take note of even a mild hallux valgus deformity;
    - examine plantar fascia and determine if windlass mechanism is intact;


- Non Operative Treatment:
    - heel cord stretching if heel cord contracture is present;
    - orthotics for the foot:
           - reduce forefoot pressure
           - transfer wt bearing to longitudinal and metatarsal arches;
           - lower heel to reduce metatarsal head pressure (avoid high heel shoes);
           - rocker bottom to shoe to reduce forefoot motion and pressures;
           - severe angle rocker sole
                    - has a more severe angle at the toe than standard designs
                    - has no heel rocker angle, which reduces weight-bearing pressures distal to the ball of the foot;
                    - indicated for extreme relief of metatarsal head or toe tip ulcerations;
           - carefully placed metatarsal pad proximal to painful metatarsal head;
           - if metatarsalgia is due to a ruptured volar plate (such as in rheumatoid arthritis), often a stiff full length insole that limits MTP hyperextension of the foot is useful;


- Operative Treatment:
    - heel cord lengthening for ankle equinus deformity;
    - in the case of a rheumatoid forefoot w/ intractable metatarsalgia consider a Hoffman procedure;
    - w/ a transfer lesion due to hallux valgus, the obvious treatment should be appropriate correction of the bunion (rather than the lesser metatarsalgia lesion);
           - this will recreate the windlass mechanism;
    - long-oblique metatarsal osteotomy;
           - if the osteotomy is not fixed, then great care needs to be taken w/ contouring the plantar arch with a well molded cast;
           - in the series by OB Idusuyi et al 1998 in which long oblique osteotomy was performed for metatarsalgia, over one half of patients had 
                 less than an optimal result;
                 - 4/23 patients had less than an optimal result;
                 - average shortening was 6 mm (+/- 6 mm);
    - chevron osteotomy:
           - in the study by Kitaoka and Patzer 1998, the authors performed chevron osteotomies of the 2nd, 3rd, and 4th metatarsals with good results in 16 out of 19 feet;
           - a detailed operative technique is outlined in this report;
                 - make a dorsal longitudinal incision over the metatarsal head (or between them if two metarasals are involved);
                 - a small drill hole is made at the junction of the metatarsal head and neck, which marks the apex of the V shaped osteotomy;
                 - make the cut at a 45 deg angle on both sides of the apex hole;
                 - the distal fragment is dorsally displaced about 2-3 mm and is then impacted;
                 - insert a K wire from proximal to distal to hold this position;
    - plantar fascia release may be appropriate for intractable metatarsalgia when it occurs w/ pes cavus;
    - adjacent hammer toe may be addressed with severe central metatarsalgia



Metatarsalgia: diagnosis and treatment.

Chevron osteotomy of lesser metatarsals for intractable plantar callosities

Effect of varying arch height with and without the plantar fascia on the mechanical properties of the foot.

Oblique metatarsal osteotomy for intractable plantar keratosis: 10 year follow up

The surgical management of central metatarsalgia.

Two modifications of the Weil osteotomy: analysis on sawbone models.

The Weil osteotomy for treatment of dislocated lesser metatarsophalangeal joints: good outcome in 21 patients with 42 osteotomies.

Metatarsal neck osteotomy with proximal interphalangeal joint resection fixed with a single temporary pin.

Comparison of the Results of the Weil and Helal Osteotomies for the Treatment of Metatarsalgia Secondary to Dislocation of the Lesser Metatarsophalangeal Joints

Neuropathic Plantar Forefoot Ulcers Treated with Tendon Lengthenings



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Thursday, May 24, 2012 2:32 pm