Operative Techniques in Orthopaedic Surgery (4 Volume Set) 1st Edition

445. Tarsometatarsal Arthrodesis

Ian L. D. Le and Mark E. Easley

DEFINITION

 Arthrodesis of the first, second, and third tarsometatarsal (TMT) joints is a relatively uncommon procedure used for the treatment of midfoot arthrosis.

 The majority of cases arise from either posttraumatic arthrosis or as part of a systemic inflammatory arthropathy.

ANATOMY

 The medial column of the foot is anatomically designed to be rigid and impart a strong lever arm for push-off, whereas the lateral column is mobile, allowing for forefoot accommodation to walking surfaces.

 Consequently, the first, second, and third TMT joints typically exhibit minimal axial or sagittal plane motion compared to the more mobile fourth and fifth TMT joints.

 Arthrosis of the first, second, and third TMT joints is best addressed surgically via arthrodesis; arthrosis of the fourth and fifth TMT joints is best addressed surgically with a motionpreserving operation including interposition or arthroplasty.

 The goal of foot surgery is to obtain a plantigrade position with normal underlying mechanical alignment to allow for weight bearing, shock absorption, accommodation, and power for efficient painless gait.

 The first TMT joint is typically 30 mm deep.

 The second TMT joint is recessed proximally in relation to the adjacent first and third TMT joints.

PATHOGENESIS

 Equinus is often an underlying pathologic feature.

NATURAL HISTORY

 There are no reported data regarding the natural history of TMT arthrosis, although it can be reasonably assumed that, with the exception of inflammatory arthropathy, most cases of midfoot arthrosis will progress at a variable rate over time, although symptoms may wax and wane.

PATIENT HISTORY AND PHYSICAL FINDINGS

 Pain is often well localized to the dorsum of the midfoot, although some patients may simply complain of a vague dorsal foot discomfort.

 Due to the lack of abundant subcutaneous tissue on the dorsum of the foot, inspection usually reveals localized swelling and osteophytic formation directly over the TMT joints.

 Palpation of the foot tenderness over the affected TMT joints that is exacerbated with motion is characteristic.

 Examination of the extensor tendons and subcutaneous tissue is done to rule out other pathology, including ganglions.

 Physical examination methods include the equinus or Silfverskiöld test. The examiner corrects the hindfoot to neutral subtalar position and checks dorsiflexion range of motion with the knee in straight extension and then flexed 30 degrees. An inability to obtain neutral dorsiflexion with the knee in straight extension that corrects with flexion is indicative of isolated gastrocnemius equinus.

IMAGING AND OTHER DIAGNOSTIC STUDIES

 Plain weight-bearing radiographs including AP, lateral, and oblique views of the foot should be obtained. Every effort should be made to obtain a true lateral radiograph with talar dome overlap.

 Seldom is a CT scan, MRI, or other imaging modality needed except to rule out a subtle Lisfranc injury.

 If there is question as to the cause of midfoot pain, a fluoroscopically guided injection of the suspected TMT joint can be both therapeutic and more importantly diagnostic.

DIFFERENTIAL DIAGNOSIS

 Lisfranc injury

 Metatarsal stress fracture

 Gout or other inflammatory arthropathy

 Ganglion

 Neuroma of the superficial or deep peroneal nerve

NONOPERATIVE MANAGEMENT

 Many patients with hallux valgus and hypermobility of the first TMT joint can be asymptomatic.

 However, once symptoms develop, progression is inevitable, in particular in patients with underlying equinus contractures.

 Initially management can be directed at resolving local symptoms, such as nonsteroidal anti-inflammatories, activity modification, rest, weight loss, shoe modifications, and orthotics.

 A stiff-soled rocker-bottom shoe or rigid orthotic minimizes motion across the midfoot, alleviating pain arising from the TMT arthrosis.

 In patients with equinus, a well-directed physiotherapy stretching protocol can be helpful.

SURGICAL MANAGEMENT

 Indication: persistent pain despite an adequate course of conservative management

 Contraindication: open physeal growth plates

Preoperative Planning

 AP foot plain radiographs are reviewed for the extent of involvement of midfoot joints and relative lengths of metatarsal heads.

 Lateral foot plain radiographs are reviewed for talar–first metatarsal angle and evidence of a cavus or planus foot.

 Based on the above, the surgeon templates an operative plan.

 The surgeon should intraoperatively assess for equinus and the need for percutaneous tendo Achilles lengthening or gastrocnemius slide.

Positioning

 Patients are placed supine on a radiolucent table with a padded wedge or bump under the ipsilateral hip to correct external rotation.

 The arm is placed across the chest and the ulnar nerve is padded.

 A tourniquet is applied either to the calf or the thigh. If proximal tibial bone graft is considered, the tourniquet should be applied on the thigh.

 The limb is exsanguinated with an elastic bandage and the tourniquet is inflated.

Approach

 Most commonly, two well-spaced longitudinal incisions are made to allow adequate exposure of the first, second, and third TMT joints.

 A 4-cm medial incision is centered over the lateral third of the first TMT joint. This allows exposure of the entire first TMT joint and the medial half of the second TMT joint.

 A 4-cm lateral incision is made over the third TMT joint. This allows exposure of the lateral half of the second TMT joint and the entire third TMT joint.

 Every effort is made to maximize the skin bridge between the two incisions to prevent wound necrosis or slough. Aggressive skin retraction must be minimized and done through deeper layers and not superficially.

TECHNIQUES

EXPOSURE OF THE FIRST AND SECOND TARSOMETATARSAL JOINTS

  Make the medial incision between the extensor hallucis longus and extensor hallucis brevis, roughly in line with the lateral third of the first TMT joint (TECH FIG 1).

  Carry dissection down with caution to avoid the dorsal cutaneous nerves.

  Identify the deep peroneal nerve with the accompanying dorsalis pedis artery just deep to the medial aspect of the extensor hallucis brevis tendon, coursing toward the first web space.

  Identify the first TMT joint by moving the first metatarsal, and cut the capsule transverse in line with the joint to minimize periosteal stripping.

  Carry the dissection up between the first and second metatarsal bases; the second TMT joint can be identified more proximally relative to the first TMT joint.

  Denude all joint surfaces of cartilage with a combination of an AO elevator, a quarter-inch osteotome, straight and curved curettes, and rongeur.

  Use a 2.0-mm drill bit to create a series of perforations in the arthrodesis surfaces to optimize surface area and blood flow. A lamina spreader can be helpful for distraction.

  In similar fashion, prepare the first TMT joint, the medial aspect of the second TMT joint, and the articulation between the first and second metatarsal bases.

  Avoid using an oscillating saw, as it can predispose to the risk of metatarsal shortening.

  It is imperative to remove cartilage all the way down to the plantar aspect of the first TMT joint to prevent excessive dorsiflexion. The first TMT joint is 28 to 30 mm deep.

TECH FIG 1 • First and second tarsometatarsal joint exposure and preparation.

  Make the second longitudinal incision described above earlier over the third TMT joint.

  Carry dissection to the extensor digitorum brevis muscle belly, avoiding the dorsal cutaneous nerves (TECH FIG 2).

  Typically, the extensor digitorum brevis cannot be retracted plantar, so instead it is split in line with the incision to expose the underlying third TMT joint.

  Again, split the periosteum in line with the joint to avoid excessive periosteal stripping.

  Expose the lateral aspect of the second TMT joint and the space between the second and third metatarsal bases.

  Prepare these arthrodesis surfaces in a similar manner to that described earlier.

TECH FIG 2 • Third tarsometatarsal joint exposure and preparation.

  Before stabilization, hold the foot in a reduced position and palpate the forefoot to ensure it is plantigrade.

  Two crossed 0.062 Kirschner wires are used to hold the first TMT joint in a reduced position. They should be placed where the final screws will ultimately be positioned (TECH FIG 3A).

  Place the first from the dorsal medial cuneiform to the plantar aspect of the first metatarsal base. Place the second from the dorsal first metatarsal shaft to the plantar aspect of the medial cuneiform.

  Reduce the second metatarsal to the middle cuneiform and the first metatarsal base. Again, palpate the forefoot to ensure the plantar metatarsal heads are level.

  Make a stab incision over the medial aspect of the medial cuneiform through the skin only. Dissect down to bone with retraction of the tibialis anterior.

  Hold the second metatarsal in place with a guide pin from the 3.0-mm cannulated screw set while protecting the tibialis anterior tendon (TECH FIG 3B).

  Aim the wire from the medial cuneiform to the base of the second metatarsal.

  Make a stab incision on the lateral forefoot to facilitate insertion of another guide pin from the 3.0-mm cannulated screw set to stabilize the third metatarsal to the cuneiforms in a reduced position (TECH FIG 3C).

  Examine the foot position to confirm plantigrade position before final stabilization.

TECH FIG 3 • A. First tarsometatarsal joint temporary fixation. B. Second tarsometatarsal joint temporary fixation. C. Third tarsometatarsal joint fixation with screw.

  The first TMT joint is stabilized first.

  Place a 3.5-mm drill sleeve over the 0.062 Kirschner wire from the medial cuneiform to the first metatarsal and use a cautery mark to mark the angulation of the wire.

  Back the 0.062 Kirschner wire out while maintaining the drill sleeve in a fixed position. Use a 3.5-mm drill followed by a 2.5-mm drill to allow insertion of a 3.5-mm cortical screw in a lag manner. Countersink the screw head before insertion.

  Use similar steps to place an additional lag screw from the first metatarsal to the cuneiform.

  Drill the second metatarsal cannulated wire with a cannulated drill.

  Use a 3.5-mm drill followed by a 2.5-mm drill to allow insertion of a lag screw. A washer may be needed due to the softer cuneiform bone.

  Protect the tibialis anterior tendon during insertion of this screw.

  Use a similar technique to insert the screw from the third metatarsal to the middle cuneiform.

  Obtain further stabilization of the second and third TMT joints by placing compression staples (TECH FIG 4).

TECH FIG 4 • A. Third tarsometatarsal joint fixation with compression staple. B. Second tarsometatarsal fixation with additional compression staple.

  Bone graft is applied to the dorsal surfaces of all arthrodesis sites.

  Autograft or allograft may be used. We often use cancellous allograft mixed with a platelet-rich derivative to promote both osteoconduction and osteoinduction.

  Autograft may be harvested from the calcaneus, proximal or distal tibia, or iliac crest.

  Obtain AP, lateral, and oblique images to ensure adequate reduction and opposition of arthrodesis sur-

faces in addition to appropriate hardware positioning (TECH FIG 5).

TECH FIG 5 • A. Intraoperative fluoroscopy of temporary stabilization. B, C. Final radiographic images.

  Deflate the tourniquet as pressure is applied to the wound.

  Obtain hemostasis and insert a drain to prevent postoperative hematoma formation.

  Reapproximate the capsule over the TMT joints with an absorbable suture.

  Reapproximate subcutaneous tissue with interrupted buried absorbable sutures.

  Close the skin with horizontal or vertical mattress nylon sutures with minimal tension.

POSTOPERATIVE CARE

 A well-molded below-knee posterior splint is applied with toes exposed.

 Analgesic control is optimal with a local or regional anesthetic in addition to oral narcotics.

 The patient is mobilized on a knee scooter, non–weightbearing.

 Progressive weight bearing is permitted between 6 and 12 weeks in a removable boot.

 The patient is weaned out of the removable boot into standard shoes at 12 weeks.

OUTCOMES

 Relatively little is published on outcomes of midfoot arthrodesis.

 With appropriate surgical indications, surgical technique, and patient compliance, patient satisfaction rates exceed 90%.

REFERENCES

1. Hansen ST. Functional Reconstruction of the Foot and Ankle. Philadelphia: Lippincott Williams & Wilkins, 2000:332–334.

2. Johnson JE, Johnson KA. Dowel arthrodesis for degenerative arthrodesis of the tarsometatarsal (Lisfranc) joints. Foot Ankle 1986;5:243–253.

3. Komenda GA, Myerson MS, Biddinger KR. Results of arthrodesis of the tarsometatarsal joints after traumatic injury. J Bone Joint Surg Am 1996;78A:1665–1676.

4. Mann RA, Prieskorn D, Sobel M. Mid-tarsal arthrodesis for primary degenerative osteoarthrosis or osteoarthrosis after trauma. J Bone Joint Surg Am 1996;78A:1376–1385.

5. Sangeorzan BJ, Veith R, Hansen ST. Fusion of Lisfranc's joint for salvage of tarsometatarsal injuries. Foot Ankle 1990;10: 193–200.

6. Vertullo CJ, Easley ME, Nunley JA. The transverse dorsal approach to the Lisfranc joint. Foot Ankle Int 2002;23:420–426.