Turf Toe

Etiology

Turf toe is most commonly sustained due to forceful hyperextension of the first MTP joint. Turf toe can occur during many sports, such as basketball, soccer, and gymnastics. Still, it is most commonly described in football, and the prevalence is far greater in athletes who play on an artificial field since it is more rigid than a natural grass field. This injury was prevalent in the past astroturf (short-pile) fields because it had a much less compliant surface and placed more strain on the players' feet. Modern (high-pile) turf behaves in a way more similar to natural turf, and the prevalence of the injury has decreased.

Pathophysiology

The first MTP is a ginglymi arthrodial joint, which functions as a hinge and a sliding joint. The shallow articulation between the convex metatarsal head and the concave base of the proximal phalanx articular surface results in little bony stability. Therefore, it relies on the complex attachments of the capsule, ligaments, and musculotendinous structures surrounding the joint. The plantar plate is the strongest stabilizer of the first MTP joint and is composed of a thickening of the joint capsule. It attaches to the transverse head of the adductor hallucis, the flexor tendon sheath, and the deep, transverse intermetatarsal ligament. The classification system is composed of the degree of injury to the plantar plate:

• Grade I: Sprain of the plantar plate.
• Grade II: Partial tear of the plantar plate.
• Grade III: Complete tear of the plantar plate

History and Physical

The patient commonly complains of pain and swelling of the first metatarsophalangeal joint. The patient may also complain of antalgic gait and pain, especially with the foot flat to toe-off during the gait cycle. The patient may or may not describe an inciting event of acute forceful hyperextension of the first MTP. There have also been reports of subacute to chronic development of turf toe.

A physical exam should include inspection, palpation, range of motion (ROM), muscle strength testing, and special testing.

• Inspection: There may be swelling and ecchymosis of the first MTP. The examiner should evaluate the patient's gait pattern and note an antalgic gait, especially with the patient favoring toe-off. The patient struggles to perform toe raises on the affected side. The examiner should also note any obvious joint deformities, including dislocation, hallux valgus, or hallux varus deformities.
• Palpation: There should be point tenderness over the plantar aspect of the first MTP. There can also be tenderness over the medial and lateral or dorsal joint. The examiner should compare the location of the sesamoid bone to the unaffected side to assess proximal migration. 
• ROM: Examiners should evaluate passive and active ROM. The patient complains of pain with extension of the first MTP with passive ROM and pain with active flexion of the first MTP.
• Muscle strength: Examiners can have the patient flex or extend the toes against resistance. Abduction can also be performed.
• Special testing: The examiner can perform a valgus and varus stress test of the first MTP joint to assess medial and lateral stability. The Vertical Lachman test tests the degree of vertical translation of the proximal phalanx compared to the metatarsal; it is important to compare this to the contralateral side. A positive test shows more laxity than the contralateral side.
  • To perform vertical Lachman, the examiner should neutralize the metatarsal head in one hand and the base of the proximal phalanx in the other; the maneuver is one of pure vertical translation at the joint. Normally, a competent plantar plate does not allow for any vertical translation. Still, normal variations of soft tissue compliance make it important to compare the affected toe to the unaffected side.

Evaluation

Initial imaging studies should be limited to anteroposterior, lateral, and axial sesamoid weight-bearing radiographs to assess for fracture or dislocation. Bilateral radiographs should be obtained to assess the migration of sesamoid bone for migration or fracture. Radiographs should be normal, but soft tissue swelling may be noted.[6][7][8][9][10]

MRI without contrast should be performed to evaluate for soft tissue pathology. MRI can evaluate for a plantar plate or surrounding soft tissue injury and assess the joint's articular surface. If this becomes a chronic process, the joint may degenerate, potentially leading to hallux rigidus or a traumatic bunion. T2-weighted MRI sequences best identify acute inflammatory changes.

Treatment / Management

Anderson Classification

Turf toe is diagnosed based on physical exam and imaging findings. According to the Anderson classification system, it is graded on a scale of 1 to 3.

• Grade 1: Acute sprain without bony pathology or joint instability; patient has normal ROM and should be able to bear weight
• Grade 2: Partial tear of the plantar plate or joint capsule; patient has painful ROM, ecchymosis, swelling, and pain with weight-bearing
• Grade 3: Complete tear with the loss of continuity of the plantar plate or capsule;patient has marked tenderness to palpation, decreased ROM, swelling, ecchymosis, and difficulty weight-bearing; migration of sesamoid bone may be noticed on physical exam.

Treatment

Regardless of the grade, initial treatment for most injuries should consist of basic RICE principles (rest, ice, compression, and elevation). A stiff-sole shoe or rocker bottom sole can also help limit motion. For more severe injuries, a controlled ankle motion (CAM) boot or walking cast can help minimize motion at the joint to allow the plantar plate to heal. Once the injury is stable, it is important to begin progressive motion.

Grade 1

Grade 1 injuries typically take a week or 2 to heal before a patient returns to play as tolerated. 

Grade 2

Grade 2 injuries typically recover in 4 to 6 weeks. When the patient returns to play as tolerated, they may require taping. Once the swelling has abated in the acute phase, taping for these injuries should focus on resisting hyperextension of the MTP joint. Corticosteroid or anesthetic injections are not advised for this injury.

Grade 3

Grade 3 injuries are more severe but usually respond to conservative treatment, albeit of longer duration. Immobilization in a CAM boot or short-leg walking cast for 4 to 6 weeks may be enough time for the healing process to begin. A progressive, gentle range of motion should follow initial immobilization and continued protected ambulation with modified shoe wear or inserts like a carbon-fiber foot-plate extension commonly used for hallux rigidus. Activity progression should be tolerated. This injury is expected to take 6 to 12 months to heal.

If the patient fails conservative management, surgical repair is an option. Characteristics of injuries that could benefit from surgical intervention are large capsular avulsion with unstable joint, diastasis or retraction of sesamoids, vertical instability, traumatic hallux valgus deformity, chondral injury, intra-articular loose body, sesamoid fracture, and failed conservative treatment.

Surgical Technique

A medial plantar incision is used to identify and protect the plantar medial digital nerve; Soft tissue injury is also identified and assessed.

• Flexor hallucis longus: Assessed for longitudinal split tears
• Plantar plate tears: These are all distal ruptures; a direct repair may be attempted if there is enough distal stump. If soft tissue is inadequate, suture anchors or drill holes can be used in the proximal phalanx to pass the suture.
• Sleeve avulsion: If there is a sleeve avulsion from a sesamoid, a hole may be drilled in the distal sesamoid to pass the suture.
• Diastasis or fracture: With diastasis or fracture of the sesamoids, one or both poles may need to be excised to repair soft tissue defects. Repair of the sesamoid fracture may be attempted with a headless screw or suture repair.

Joint synovitis or osteochondral defects often require debridement or cheilectomy. If the plantar plate or flexor tendons cannot be restored, abductor hallucis transfer may be required.

Postoperative Management

Patients can begin gentle passive motion at 7 to 10 days with a physical therapist, then be non–weight bearing in a removable splint or boot with Hallux protected for 4 weeks. At 4 weeks, active motion can be increased, and ambulation can be allowed in the boot. Patients should wear modified shoes at 2 months and return to contact activity to protect themselves from excessive dorsiflexion at 3 to 4 months. A full recovery can be expected in 6 to 12 months.

Differential Diagnosis

The differential diagnoses for turf toe include the following:

• Hallux limitus
• Hallux rigidus
• Hallux valgus
• Reverse turf toe
• Soccer toe

Prognosis

The outlook for turf-toe recovery is commensurate with the grade of the injury. More severe injuries require additional recovery time. Some cases result in incomplete recovery, joint stiffness, or an arthritic toe. Prevention of re-injury is paramount to avoiding long-term sequelae.[11]

Complications

Complications of turf toe can include the following:

• Loss of push-off strength
• Hallux rigidus
• Cock-up deformity
• Traumatic bunion deformity
• Loose bodies in the joint space
• Joint fibrosis

Acute complications include infections, scar formation secondary to hypertrophy, and plantar nerve neuroma development.[12]