Understanding Hammertoe Deformity

Hammertoe is a progressive flexion deformity of the proximal interphalangeal joint (PIPJ) — the middle joint of the lesser toes — that causes the toe to curl downward into a hammer-like shape. In early stages, the deformity is flexible: the toe can be passively straightened by the examiner. In advanced stages, the joint capsule and collateral ligaments contract, producing a rigid deformity that cannot be passively corrected. The dorsal prominence of the bent PIPJ creates painful pressure against shoe uppers; the tip of the toe may develop painful callus from downward pressure against the shoe sole.

Conservative management — accommodative footwear with adequate toe box height and width, silicone toe caps, and protective padding — addresses symptoms in flexible deformities and delays progression. When rigid deformity produces persistent pain that conservative care cannot adequately manage, surgical correction is indicated. Two primary surgical techniques are available: proximal interphalangeal joint arthroplasty and proximal interphalangeal joint arthrodesis.

PIPJ Arthroplasty (Joint Resection)

What It Is

PIPJ arthroplasty — also called Keller-type arthroplasty or condylectomy — corrects hammertoe by resecting (removing) the head of the proximal phalanx and the base of the middle phalanx, creating a gap at the PIPJ that fills in with fibrous tissue as it heals. The fibrotic ‘pseudarthrosis’ that forms is not a true joint (hence the term ‘arthroplasty’ is slightly misleading) but rather a flexible fibrous connection that allows the toe to straighten without creating a bone-to-bone fusion.

Surgical Technique

PIPJ arthroplasty is performed through a dorsal elliptical skin incision over the PIPJ. The extensor tendon and joint capsule are incised longitudinally. The condyles of the proximal phalanx head are excised with bone-cutting forceps or a small oscillating saw; the articular base of the middle phalanx is similarly resected, creating a gap of approximately 5–6mm. The toe is held in corrected alignment with a smooth Kirschner wire (K-wire) driven through the pulp of the toe, across the PIPJ site, and into the medullary canal of the proximal phalanx. The K-wire remains in place for 3–4 weeks while the fibrous union develops, then is removed in office without anesthesia.

Advantages of Arthroplasty

• Preserves some toe flexibility — the pseudarthrosis is not as rigid as a fusion
• Technically faster than arthrodesis in experienced hands
• Appropriate for elderly patients or those with poor bone quality where fusion healing is uncertain
• No risk of non-union (there is no bone-to-bone healing required)

Disadvantages of Arthroplasty

• Toe may be floppy and unstable after K-wire removal — ‘floating toe’ or ‘cock-up’ deformity risk
• Toe shortening may be more pronounced than with arthrodesis
• Higher recurrence rates compared to arthrodesis in some series
• May not provide adequate correction for severe or complex deformities

PIPJ Arthrodesis (Joint Fusion)

What It Is

PIPJ arthrodesis fuses the proximal and middle phalangeal bones across the PIPJ, creating a rigid permanent correction. Rather than resecting bone to create a mobile gap, arthrodesis prepares the joint surfaces for bone healing and holds them in corrected position until solid fusion occurs. The result is a permanently straight, somewhat rigid toe — but one with excellent stability and predictable correction.

Surgical Technique

The PIPJ joint surfaces are accessed through a dorsal incision as in arthroplasty. The articular cartilage of both the proximal phalangeal head and the middle phalangeal base is removed with a rongeur or burr until bleeding cancellous bone is exposed on both surfaces. The toe is then positioned in slight plantarflexion (5–10 degrees below neutral) — the optimal fusion position that allows the toe tip to contact the ground during walking without excessive pressure. Fixation options include:

• Single smooth Kirschner wire: simple, inexpensive, removed at 4–6 weeks; slightly higher recurrence and malunion risk
• Absorbable PIPJ fusion implants (Arthrex StayFuse, Integra Smart Toe): pre-bent titanium or nitinol implants that passively straighten to apply corrective force during healing, remain in place permanently
• Bone-fixation headless screws: provide compression across the fusion site, retained permanently

Advantages of Arthrodesis

• More durable correction with lower recurrence rates compared to arthroplasty
• Better toe stability — no risk of ‘floating toe’ deformity
• Implant-based fusion devices eliminate K-wire removal burden and may improve patient comfort during the healing period
• Preferred for younger, more active patients where long-term correction durability is a priority

Disadvantages of Arthrodesis

• Risk of non-union (fibrous union without solid bone healing) — occurs in approximately 5–10% of cases; most non-unions are asymptomatic
• Toe is permanently rigid at the PIPJ — no flexibility preserved
• Implant-retained devices carry small risk of implant-related complications (migration, infection)

Choosing Between the Two: Decision Framework

The choice between arthroplasty and arthrodesis depends on: patient age and activity level (younger, more active patients generally benefit from arthrodesis durability); deformity severity and rigidity (more severe deformities are better corrected with arthrodesis); associated conditions (diabetes or vascular disease may impair bone healing, making arthroplasty safer); and surgeon experience and preference.

Recovery

Both procedures allow immediate weight-bearing in a surgical shoe post-operatively. Transition to regular footwear occurs at 3–4 weeks for arthroplasty (after K-wire removal) and 4–6 weeks for arthrodesis (pending fusion progress). Return to athletic activity typically occurs at 6–8 weeks for simple hammertoe correction in otherwise healthy patients.

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Dr. Tom Biernacki, DPM

Dr. Tom Biernacki, DPM is a double board-certified podiatrist and foot & ankle surgeon at Balance Foot & Ankle Specialists in Southeast Michigan. With over a decade of clinical experience, he specializes in heel pain, bunions, diabetic foot care, sports injuries, and minimally invasive surgery. Dr. Biernacki is a member of the APMA and ACFAS, and his patient education content on MichiganFootDoctors.com and YouTube has reached over one million views.