Summary

Freiberg Infraction is an osteochondrosis (Avascular Necrosis) of the metatarsal head, predominantly affecting the 2nd Metatarsal (68%) in adolescent females. It is caused by repetitive microtrauma or vascular compromise, leading to subchondral bone collapse and flattening of the articular surface. The dorsal aspect of the metatarsal head collapses first, creating a characteristic "squared off" appearance. If untreated, it progresses to severe secondary osteoarthritis (Hallux Rigidus of the lesser toe). The mainstay of surgical treatment is the Dorsal Closing Wedge Osteotomy (Gauthier), which rotates the healthy plantar cartilage dorsally to restore the joint surface. [1,2,3]

Key Facts

• The Victim: The classic patient is a 14-year-old female athlete (dancer/gymnast) complaining of forefoot pain.
• The Site: Usually the 2nd Metatarsal Head (longest metatarsal, anchors the foot). Occasionally the 3rd. Rarely the 4th/5th.
• The Mechanism: The 2nd Metatarsal is locked in the mortise (Lisfranc). During push-off (high heels/relevé), the dorsal aspect of the head impinges against the proximal phalanx, cutting off blood supply.

Clinical Pearls

"The Flat Head Sign": On X-ray, the metatarsal head looks flattened (like a plateau) rather than round. This "squaring" is diagnostic.

"Smillie's Stages": The progression from a simple fissure (Stage 1) to a loose body (Stage 3) to total joint destruction (Stage 5) dictates treatment.

"Rotate the Head": The plantar cartilage is almost always preserved (because the toe dorsiflexes away from it). The genius of the Gauthier osteotomy is simply rotating this good cartilage up to become the new weight-bearing surface.

                 FOREFOOT PAIN (2nd MTP)
                           ↓
                  X-RAY + CLINICAL EXAM
            ┌──────────────┴──────────────┐
         NORMAL                         ABNORMAL
      (Suspect Stage I)             (Stage II-V)
           ↓                              ↓
          MRI                      SMILLIE STAGE?
           ↓                  ┌───────────┴───────────┐
        EDEMA?              EARLY (I-III)           LATE (IV-V)
      ┌────┴────┐             ↓                       ↓
     YES       NO        CONSERVATIVE              SURGERY
    (Boot)   (Other)    (Metatarsal Bar)          (Osteotomy)

Indications

• Stage I, II, III (Early).
• Acute flare-ups.

Protocol

• Offloading:
  • Walking Boot: 4-6 weeks for acute pain.
  • Metatarsal Bar: A pad placed proximal to the metatarsal heads to offload weight from the head to the shaft.
  • Stiff Soled Shoe: Prevents dorsiflexion.
• Activity Modification: Stop dance/running for 3 months.

Indications

• Failed conservative treatment.
• Loose bodies causing locking (Stage III).
• End-stage arthritis (Stage V).

Techniques

1. Debridement (Cheilectomy):
   • Removal of osteophytes and loose bodies.
   • For mild cases.
2. Dorsal Closing Wedge Osteotomy (Gauthier):
   • The Workhorse.
   • A wedge of bone is removed from the dorsal neck. The head is tilted up.
   • Effect: Bringing the healthy plantar cartilage to the dorsal / axial position.
   • Fixation: Screw or K-wire.
3. Metatarsal Head Resection (DuVries):
   • Old operation. Causes "Floppy toe" (Transfer metatarsalgia). Not recommended.
4. Joint Replacement:
   • Silicone/Ceramic. Poor long-term results in young active patients.

The Gauthier Osteotomy

• Gauthier & Elbaz (1979): Reported 90% satisfaction. The biological rationale (rotating healthy cartilage) makes it superior to resection or replacement.

Vitamin D

• Always screen these patients for Vitamin D deficiency, as it predisposes to bone stress injury.

The Condition

The "cap" of the bone in your second toe has died because it lost its blood supply. It has collapsed like a crushing eggshell, making the joint square instead of round.

Who gets it?

Teenage girls, especially dancers or those with high arches.

The Treatment

We try to rest it first. If the bone is crumbling, we do an operation to "tilt" the bone head, moving the bad part out of the way and putting the good part (from underneath) into the main joint space.

Q1: What is Smillie's Classification? A: A 5-stage radiological classification for Freiberg's Infraction. I: Fissure. II: Central collapse (depression). III: Loose body (detached central fragment). IV: Multiple loose bodies + Head flattening. V: End-stage arthritis.

Q2: Describe the Gauthier osteotomy. A: A Dorsal Closing Wedge osteotomy of the metatarsal neck. It extends, shortens, and elevates the head, but most importantly, it rotates the intact plantar articular cartilage dorsally to replace the damaged surface.

Q3: Which metatarsal is most commonly affected? A: The Second (68%). Followed by the Third (27%).

Q4: Differentiate Freiberg's from a Stress Fracture. A:

• Freiberg: Involves the articular surface (Head/Epiphysis). Can lead to joint destruction.
• Stress Fracture: Usually involves the Shaft or Neck (extra-articular). Heals with callus, usually leaves joint intact.

(End of Topic)