Hammertoe Deformity Workup

Updated: Feb 07, 2023
  • Author: Anthony Watson, MD; Chief Editor: Vinod K Panchbhavi, MD, FACS, FAOA, FABOS, FAAOS  more...
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Laboratory Studies

If inflammatory arthropathy is suspected, serologic evaluation should be considered. Tests include evaluation of rheumatoid factor (RF), antinuclear antibody (ANA), human leukocyte antigen (HLA) B27, and Lyme titers.


Imaging Studies

Radiographic evaluation of hammertoe is not necessary for clinical diagnosis; however, it can be helpful for ruling out alternative diagnoses and can aid in surgical planning. Imaging considerations in the evaluation of hammertoe deformity include the following:

  • Weightbearing anteroposterior and lateral radiographs of the involved foot are useful (see the images below)
  • Intra-articular and periarticular erosions suggest rheumatoid arthritis and psoriatic arthritis, respectively
  • Enlargement of the metatarsal head and osteophytes suggests a previous Freiberg infraction
  • Varus angulation and/or dorsal subluxation or widening of the joint space of the metatarsophalangeal (MTP) joint suggests MTP instability
  • The presence of other deformities should be noted, especially hallux valgus (see the images below), which is associated with the "crossover" toe deformity
Anteroposterior radiograph showing hammertoe defor Anteroposterior radiograph showing hammertoe deformity in second toe and associated hallux valgus deformity in forefoot.
Lateral radiograph showing hammertoe deformity. Lateral radiograph showing hammertoe deformity.

Histologic Findings

Histologic evaluation is typically not available or necessary before hammertoe treatment. Skin ulceration and osteomyelitis may occur in neuropathic patients with hammertoe deformity. Histologic confirmation of osteomyelitis precludes most hammertoe reconstruction procedures.