48 Forefoot Fractures


48 Forefoot Fractures

Matthew I. Rudloff


Forefoot fractures are frequently encountered in the clinical setting. The forefoot contributes to the intricate biomechanical performance of the foot during gait, and injuries to this anatomic area can result in significant disability. While many injuries to the forefoot can be successfully managed by nonoperative means, surgical intervention may be preferred in some circumstances.

I. History and Physical Examination

  1. A careful history should not only include the mechanism of injury but also any remote injury, previous surgery, ambulatory status, and medical or social comorbidities that may influence decision-making, such as diabetes, neuropathy, or peripheral vascular disease.

  2. Injury mechanisms typically are direct trauma or torsional for the metatarsals and phalanges, whereas a hyperextension moment is responsible for most metatarsophalangeal (MTP) dislocations.

  3. Physical examination should include systematically inspecting and palpating the foot. Comparison to the contralateral foot can aid in identifying focal abnormalities.

  4. A thorough neurovascular examination should be performed. Consider monofilament testing when concerns for underlying neuropathy exist.

  5. Soft-tissue condition should be noted, particularly any impending compromise from fracture displacement, or open injuries.

  6. Excessive or worsening pain should alert one to the potential for foot compartment syndrome and subsequent treatment.

II. Anatomy

  1. First metatarsal

    1. Shorter and wider.

    2. Responsible for bearing one-third of the body’s weight, in conjunction with its respective sesamoids.

    3. Anterior tibialis and peroneus longus insert upon the first metatarsal, creating deforming forces when fractured.

    4. No distal intermetatarsal ligament to provide stability.

  2. Second through fourth metatarsals

    1. Inherent stability afforded by the distal intermetatarsal ligaments.

  3. Fifth metatarsal

    1. Peroneus brevis and lateral band of plantar fascia insertion result in avulsion fractures with inversion injuries (pseudo-Jones’ fracture; ▶ Fig. 48.1 ).

      Fig. 48.1 Lawrence and Botte classification of the proximal fifth metatarsal fractures.

    2. Metatarsal metaphysis is supplied by retrograde nutrient vessel flow, creating a relatively avascular watershed area that can predispose to healing difficulties (Jones’ fracture; ▶ Fig. 48.1 ).

  4. Metatarsophalangeal joints

    1. Stabilized primarily by the dorsal capsule, and plantar plate complex.

    2. First MTP further stabilized by the extensor hallucis longus, flexor hallucis longus, and brevis tendons.

III. Imaging

  1. Three-view radiographic evaluation

    1. Anteroposterior, oblique, and lateral.

    2. Weight-bearing radiographs.

    3. Contralateral comparison films.

  2. Computed tomography

    1. CT may be used to further evaluate fracture comminution for surgical planning, particularly for the first metatarsal.

  3. Magnetic resonance imaging

    1. MRI is useful in evaluation of suspected stress fractures.

IV. Classification

  1. First through fourth metatarsals

    1. Location (neck, shaft, and base).

    2. Displacement.

    3. Comminution.

    4. Angulation.

    5. Articular involvement/dislocation.

  2. Fifth metatarsal

    1. Dancer fracture: distal spiral fracture of the fifth metatarsal (▶ Fig. 48.2 ).

      Fig. 48.2 Distal diaphyseal fracture of the fifth metatarsal.

    2. Proximal (Lawrence and Botte; ▶ Fig. 48.1 ).

      1. Pseudo-Jones’ fracture.

      2. Jones’ fracture.

  3. First metatarsophalangeal joint dislocation (▶ Table 48.1 )

    Table 48.1 Jahss’ classification for dislocations of the first metatarsophalangeal joint

    Type I

    Proximal phalanx is dislocated dorsally, and intersesamoid ligament is intact

    Type IIA

    Proximal phalanx is dislocated dorsally, and intersesamoid ligament is disrupted

    Type IIB

    Dislocation with associated sesamoid fracture

  4. Lesser metatarsophalangeal joint dislocations and phalangeal fractures: descriptive classification.

V. Treatment

  1. Goal is to maintain or restore anatomy to permit normal load distribution across the foot.

  2. First metatarsal fractures

    1. Displacement disrupts the first metatarsal’s critical role in forefoot weight bearing, and therefore little coronal or sagittal malalignment is tolerated.

    2. Initial management: open or impending soft-tissue injury may warrant reduction or temporizing provisional Kirschner’s wire fixation, or external fixation in select circumstances (▶ Fig. 48.3 ).

      Fig. 48.3 External fixation can provide provisional stability for higher energy fractures with significant soft-tissue disruption, such as this ballistic injury.

    3. Definitive management:

      1. Nonoperative treatment is appropriate for minimally displaced or nondisplaced fractures.

      2. Malunion can result in transfer metatarsalgia, in which the normal physiologic load is shifted laterally to the lesser toes resulting in painful weight bearing. Therefore, operative intervention is indicated in displaced injuries.

    4. Surgical approach:

      1. Dorsal approach—skin incision in line with the first ray. Deep interval is between the extensor hallucis longus and hallucis brevis. Protect the dorsomedial cutaneous nerve to the hallux medially, and the digital branch of the deep peroneal nerve to the second toe.

      2. Medial approach—skin incision in line with the first ray. The internervous interval is between the dorsomedial cutaneous nerve and the medial plantar hallucal nerve. The abductor hallucis muscle is retracted plantarly.

    5. Fixation technique:

      1. If anatomic closed reduction can be achieved, or significant soft-tissue injury precludes a formal surgical approach, then closed reduction and stabilization with Kirschner’s wires can be performed.

      2. Otherwise, internal fixation with interfragmentary lag screws, neutralization plating, or bridge plating may be performed with low-profile small fragment (3.5-mm), mini-fragment (2.7-mm), or anatomic plates.

      3. Fractures with proximal articular involvement can be addressed with fixation extending across the tarsometatarsal joint (▶ Fig. 48.4 ).

        Fig. 48.4 Comminuted first metatarsal shaft with proximal articular extension.

    6. Complications—hardware prominence.

    7. Rehabilitation:

      1. Nonoperatively managed fractures can be initially immobilized with a cast or boot, immediate weight bearing as tolerated versus non-weight bearing for 4 to 6 weeks.

      2. Following operative stabilization, a splint can be applied until the surgical wound is appropriate, and then subsequent conversion to a cast or boot. Non–weight bearing for 4 to 6 weeks, followed by gradual progression.

  3. Second through fourth metatarsals

    1. Definitive management:

      1. Central metatarsal fractures can frequently be managed nonoperatively with a hard-sole orthosis and weight bearing as tolerated when isolated and minimally displaced.

      2. Operative treatment should be considered for greater than 4 mm of displacement, greater than 10 degrees of sagittal plane deformity, and multiple metatarsal fractures.

      3. Coronal malalignment is better tolerated than displacement in the sagittal plane. The typical dorsal angulation results in the plantar flexion of the distal metatarsal, thus resulting in abnormal loading and transfer metatarsalgia.

      4. Metatarsal shaft fractures, unless multiple, or with significant sagittal plane displacement, can be managed nonoperatively.

      5. Metatarsal base fractures often are inherently more stable and can be treated nonoperatively, provided a more significant injury to the Lisfranc articulations can be ruled out.

    2. Surgical approach:

      1. Percutaneous incisions, localized under fluoroscopy, can facilitate closed reduction maneuvers for fixation.

      2. Dorsal intermetatarsal approach:

        • i. Exposure to the second and third metatarsals—make a longitudinal incision in this web space. The deep interval is then between the long and short toe extensor tendons.

        • ii. Exposure to the fourth metatarsal—the incision is located along the dorsolateral aspect.

        • iii. Fourth metatarsal base fractures—the deep interval lateral to the long extensor of the fifth toe, whereas for more distal fractures, deep dissection occurs between the long extensor of the fourth and fifth toes.

    3. Fixation technique:

      1. Metatarsal fractures can be stabilized with mini-fragment plates (▶ Fig. 48.5 ), screws, or Kirschner’s wires (▶ Fig. 48.6 ). Joint spanning plates can be utilized in the setting of extensive comminution of the base.

        Fig. 48.5 Mini-fragment fixation for open multiple metatarsal fractures.
        Fig. 48.6 Intramedullary Kirschner’s wire fixation for multiple displaced metatarsal fractures.

      2. Most lesser metatarsal neck and shaft fractures can be stabilized with intramedullary Kirschner’s wires, and less commonly mini-fragment devices.

      3. Adjuvant Kirschner’s wires or a percutaneously placed dental pick can aid in reduction prior to fixation.

      4. Intramedullary Kirschner’s wires can be placed retrograde, or through limited exposures in an antegrade/retrograde fashion.

      5. When using the retrograde technique, dorsiflexion of the toe can facilitate a central starting point on the metatarsal head, but can result in extension of the toe. Alternatively, the wire can be inserted into the base of the proximal phalanx, in line with the medullary canal of the metatarsal.

    4. Complications: Toe stiffness can occur with wire fixation. Malunion can lead to transfer metatarsalgia.

    5. Rehabilitation:

      1. Isolated, nondisplaced, or minimally displaced fractures can be treated with a hard-sole orthosis and permitted to weight bear as tolerated.

      2. Fractures treated with intramedullary Kirschner’s wires typically are protected in a splint, and converted to a cast. Heel weight bearing is allowed. Pins are typically removed between 4 and 6 weeks once radiographic progression of healing is noted.

  4. Fifth metatarsal

    1. Definitive management:

      1. Distal fractures can be managed similar to the central metatarsals. Significant angulation resulting in malunion can impact shoe wear.

      2. Proximal fractures require greater attention given the propensity for nonunion complications.

      3. Zone 1 (avulsion: pseudo-Jones’) fractures can typically be managed nonoperatively, unless the fragment has extensive involvement and is displaced greater than 2 mm and greater than 30% of the metatarsal cuboid articulation.

      4. Zone 2 (metadiaphyseal: Jones’) fractures managed nonoperatively require cast immobilization and non–weight bearing for minimum of 6 weeks, followed by gradual progression. Displaced fractures or those in younger, high-demand individuals benefit from operative fixation. Fractures that are subacute, stress fractures, or refractures are best treated surgically.

    2. Surgical approaches:

      1. Percutaneous approach—the appropriate starting portal is at the center of the base of the metatarsal.

      2. Lateral approach to the fifth metatarsal—skin incision begins just proximal to the styloid, proceeding distally. Incise the abductor digiti quinti fascia, retracting the musculature plantarly, exposing the metatarsal.

    3. Fixation techniques:

      1. This is typically performed by percutaneous placement of an intramedullary screw in acute fractures. Screw size should permit engagement of the threads into the diaphyseal cortical bone, without disrupting it.

      2. Alternative modalities include mini-fragment plates and tension band constructs but necessitate larger surgical exposures.

    4. Complications:

      1. Nonunion up to 20% of nonoperatively treated fractures.

      2. Implant-related complications include hardware prominence, hardware penetration, and secondary screw removal. Nonunion and refracture can also occur.

    5. Rehabilitation:

      1. Immobilization in a non–weight bearing cast or boot for a minimum of 6 weeks, potentially longer depending upon radiographic progression.

      2. Time to union of nonoperatively managed metadiaphyseal fractures has been reported to be 16 weeks, whereas those treated acutely in a surgical manner heal in 7 to 8 weeks. Operative intervention in this subset of fractures permits earlier return to function.

  5. First metatarsophalangeal joint dislocation

    1. Definitive management: Urgent closed reduction should be attempted under local digital block anesthesia. If unsuccessful, operative open reduction should be undertaken. Typically, these are Jahss’ type I injuries, where the first metatarsal head has become incarcerated with the plantar plate complex (▶ Table 48.1 ).

    2. Surgical approach: Dorsal approach to the MTP joint—skin incision medial to the extensor hallucis longus tendon. The plantar plate, which may require release, can then be reduced from the metatarsal head. Residual instability may rarely require Kirschner’s wire fixation.

    3. Complications—stiffness, nonconcentric reduction, and osteoarthritis from chondral injury.

    4. Rehabilitation—Immobilization with a hard-sole orthosis, with dorsiflexion limitation for 4 weeks. If Kirschner’s wire fixation is necessary, wires can be removed at 4 weeks.

  6. Lesser toe metatarsophalangeal dislocations (▶ Fig. 48.7 )

    Fig. 48.7 Irreducible fifth metatarsophalangeal dislocation with associated the fourth metatarsal neck fracture, requiring open reduction.

    1. Definitive management: similar to dislocations of the first MTP.

  7. Phalangeal fractures

    1. Definitive management:

      1. Almost all phalangeal fractures can be managed by nonsurgical means. Nondisplaced or minimally displaced fractures can be effectively treated with buddy taping and a hard-sole orthosis.

      2. Displaced fractures with visible deformity of the toe can be closed under digital anesthesia with longitudinal traction and correction of angulation.

      3. Operative intervention considered for displaced intra-articular fractures of hallux.

    2. Complications: Malunion can occur; however, it is rarely symptomatic.

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Jun 26, 2020 | Posted by in ORTHOPEDIC | Comments Off on 48 Forefoot Fractures
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