Fracture, Fifth Metatarsal (Avulsion, Jones Fractures)

By admin On Dec 6, 2023

Ovid: 5-Minute Sports Medicine Consult, The

Mark E. Lavallee

R. Michael Galbraith

Basics

Description

Fractures of the proximal 5th metatarsal of the foot occur at different locations, often with different etiologies. Prognosis and treatment differ vastly, and there is potential to have chronic pain and instability of the foot if not treated properly. Proximal 5th metatarsal fractures are classified into 3 types by region, especially in relation to the joint at the base of the 4th/5th metatarsals (1,2,3,4):
- Avulsion fracture of the tuberosity:
  - Near splayed insertion of the peroneus brevis tendon (within 0.5 cm from proximal tip of 5th metatarsal)
  - Located extra-articular and do not extend into the joint between the 4th and 5th metatarsal (cubometatarsal joint)
- Jones fracture (metaphyseal–diaphyseal junction):
  - Fracture line extends into or towards the articulation between the bases of the 4th and 5th metatarsals (measuring from the proximal tip of the 5th metatarsal, >0.5 cm and <1.5 cm)
  - Have relative poor blood supply, heal more slowly, and are prone to delayed union and nonunion
- Diaphyseal stress fractures:
  - Most commonly occur just distal to the 4th and 5th intermetatarsal articulation to midshaft
  - Result of chronic, repetitive microtrauma, especially in younger athletes
  - Heal most slowly and have greatest risk of delayed union, nonunion, and recurrence
- Subtypes according to healing potential (5):
  - Type I (acute): Acute without prior pain. X-rays show clean fracture without sclerosis.
  - Type II (delayed union): Involve prior symptoms or a known stress fracture. X-rays show medullary sclerosis and a widened fracture line.
  - Type III (nonunion): Involves prior symptoms or a known stress fracture. X-rays show evidence of repeated trauma, widened fracture line, and exuberant sclerosis (suggesting fracture nonunion).
Synonym(s): Dancer's or tennis fracture: avulsion fracture of base of the 5th metatarsal

Epidemiology

Fractures of the proximal 5th metatarsal are common foot fractures.
Avulsion fractures are the most common type of fracture.
Diaphyseal stress fractures are the least common type of fracture.

Risk Factors

Previous fracture to the proximal 5th metatarsal
Lateral ankle instability

Commonly Associated Conditions

Lateral ankle sprain: Tuberosity avulsion fractures are commonly associated with ankle sprains with the foot inverted and plantar flexed. The anterior talofibular and calcaneofibular ligaments often are injured, and there may be swelling and ecchymosis just anterior and distal to the lateral malleolus.
Proximal 5th metatarsal stress fracture: Patient may have had a previously undiagnosed and slightly symptomatic stress fracture of the proximal 5th metatarsal.
There is a high incidence of delayed union, nonunion, and refracture with Jones and diaphyseal stress fractures.

Diagnosis

Postreduction views are only applicable when clinician attempts to reduce a significantly displaced fracture of the 5th metatarsal. Most displaced fractures are best treated operatively. Views would be anteroposterior, lateral, and oblique

History

How and when did it occur? Mechanism of injury is important to determine.
Did athlete injure this foot previously? Determine presence of fracture of the 5th metatarsal.
Was there a recent history of ankle sprain prior to this injury? Loss of proprioception and reflex inhibition may have predisposed athlete to this injury.
History of other medical conditions? Diabetes or other causes of peripheral neuropathy.

Physical Exam

Patient may complain of pain over the lateral aspect of foot, especially when weight-bearing on plantar-flexed foot.
Jones fractures often occur as a result of a pivot in the direction opposite the planted foot.
Patient is tender to palpation over the proximal 5th metatarsal.
Often there may be swelling or ecchymosis of the proximal 5th metatarsal.
Check neurovascular status: Posterior tibial and dorsalis pedis pulses and normal capillary refill
Palpate the peroneus brevis tendon to assess its integrity.
Resisted external rotation of foot activates the peroneus brevis muscle and checks its strength.
Full examination of the distal fibular, lateral ligaments, and foot helps identify associated ankle or foot injury.
Check sensation: If decreased around lateral aspect of foot, the lateral dorsal cutaneous nerve, a branch off the sural nerve, may be injured.

Diagnostic Tests & Interpretation

Imaging

Standard x-ray films: Anteroposterior (AP), lateral, and oblique views of the foot. If findings are suggestive of ankle trauma meeting the Ottawa criteria for radiographs, ankle films (AP, lateral, and oblique views) also should be taken. The Ottawa Ankle rules state that radiographs are indicated for patients between the ages of 15 and 55 yrs old with inability to walk 5 steps after an ankle injury OR tender over posterior 3rd of distal fibula.

Differential Diagnosis

Peroneus brevis tendon injury
Apophysis (secondary ossification center closes between ages 9 and 11 yrs in girls, 11 and 14 yrs in boys)
Apophysitis (Iselin disease)
Accessory ossicles
Hematoma of lateral proximal foot
Midshaft diaphyseal fracture of the 5th metatarsal
Sprain of the cubometatarsal joint

P.197

Treatment

Apply ice, rest, and elevate foot.
Oral pain relief (acetaminophen, tramadol, or narcotics) or topical lidocaine is often sufficient if reduction not necessary.
If reduction is needed, give oral pain relief before performing a hematoma block (2–5 mL of 1% lidocaine).
Significantly displaced fracture warrants an orthopedic referral for possible surgery.
Reduction techniques generally not recommended if surgical fixation is an option
Grab the 5th toe and distract in a longitudinal plane. Apply plantar or dorsal pressure to the proximal portion of the 5th metatarsal.
Check alignment via postreduction radiographs.
Avulsion fractures:
- Place in a hard-soled shoe or post-op shoe for 3–4 wks (2,3)[A].
- Can place in a walking boot or walking cast if worried about patient compliance. May weight-bear as tolerated (1,2)[A].
Jones (metaphyseal–diaphyseal) fractures and diaphyseal stress fractures:
- Type I (acute): For nondisplaced or minimally displaced fractures (<2 mm), can place patient in short leg cast and make strict non-weight-bearing for 6–8 wks (or longer). Otherwise, consider surgical fixation (1,2)[A].
- Type II (delayed union/stress): Consider surgical fixation because of better prognosis and quicker return to activity. Occasionally can consider prolonged immobilization (up to 16 wks) with non-weight-bearing for selective patients (1,2)[A].
- Type III (nonunion): Consider surgical fixation (1,2)[A].

Additional Treatment

Additional Therapies

When deciding on treatment for type II fractures, take into account athlete's timetable and previous medical history.
Occasionally after conservative treatment, a nonunion develops secondary to “distal to proximal” vascular supply to the bone.
Bone stimulation (electrical or US) has shown in some cases to improve healing for delayed union and nonunion fractures (1)[B]. Progression to surgery may be indicated instead of using bone stimulation or if there is inadequate healing with bone stimulation.
Avulsion fractures: Start with range of motion and progress to strengthening of the peroneus brevis (external rotation and pronation of the foot). Patient may return to play after 3–4 wks and when no longer symptomatic.
Jones fractures: Once no longer immobilized, start with range of motion and progress to strengthening. Electrical stimulation may help patient initially learn to reactivate musculature. Resume weight-bearing activities slowly.

Surgery/Other Procedures

Avulsion fractures rarely require surgery (2)[A].
Jones (metaphyseal–diaphyseal) and diaphyseal stress fractures:
- Type I: Consider surgical fixation (open reduction, internal fixation with a cannulated screw) for athletes and active patients who wish quicker return to play (1,2,4)[A].
- Type II (delayed union) and type III (nonunion): Refer for surgical evaluation (1,2)[A].

Ongoing Care

Follow-Up Recommendations

Orthopedic referral for surgery as indicated above and for avulsion fractures that are displaced (rare), comminuted (rare), or involve >30% of the cubometatarsal articulation
Patients not responding to home exercise programs after immobilization is complete may benefit from referral to physical therapy.
Type I Jones or diaphyseal stress fractures should be referred to an orthopedist if patient prefers surgery in order to return to play quicker or the fracture is displaced or comminuted.

References

1. Brown SR, Bennett CH. Management of proximal 5th metatarsal fractures in the athlete. Curr Opin Ortho 2005;16:95–99.

2. Fetzer GB, Wright RW. Metatarsal shaft fractures and fractures of the proximal 5th metatarsal. Clin Sports Med. 2006;25:139–150, x.

3. Hatch RL, Alsobrook JA, Clugston JR. Diagnosis and management of metatarsal fractures. Am Fam Physician. 2007;76:817–826.

4. Mologne TS, Lundeen JM, Clapper MF, et al. Early screw fixation versus casting in the treatment of acute Jones fractures. Am J Sports Med. 2005;33:970–975.

5. Torg JS, Balduini FC, Zelko RR, et al. Fractures of the base of the 5th metatarsal distal to the tuberosity. Classification and guidelines for non-surgical and surgical management. J Bone Joint Surg Am. 1984;66:209–214.

Codes

ICD9

733.94 Stress fracture of the metatarsals
825.25 Fracture of metatarsal bone(s), closed
825.35 Fracture of metatarsal bone(s), open