CHAPTER 89
Mallet Toe
Vasilios A. Lirofonis, DPM; Robert J. Scardina, DPM
Definition
Mallet toe refers to an abnormal flexion deformity at the distal interphalangeal (DIP) joint (Fig. 89.1). Typically, the metatarsophalangeal and proximal interphalangeal joints are aligned in neutral position without extension or flexion. The most commonly affected toe is the longest toe, usually the second. The deformity may be fixed (rigid), semirigid, or flexible; it may occur unilaterally or bilaterally, and it may be acquired or congenital. High-heeled shoes and shoes with a narrow toe box may aggravate the deformity; it is present symptomatically more in women [1,2]. There is some observational evidence to suggest that a toe longer than adjacent toes is at increased risk for development of lesser toe deformities [3]. The incidence of a mallet toe deformity is much less common than that of a hammer toe deformity at almost 1:10 [4]. This is likely to be related to presentation rates as hammer toes are typically more problematic compared with mallet toe deformity.
Symptoms
Patients typically complain of pain or tenderness in the area of the dorsal DIP joint or distal aspect of the toe, most commonly when wearing shoes, particularly with a narrow toe box. The symptoms are also worse during weight-bearing activities, such as running. Patients may also have complaints of toenail deformities, which eventually may become painful. A painful corn or clavus may develop on either the dorsal aspect of the DIP joint (as a result of shoe irritation) or the distal aspect of the toe.
Physical Examination
The degree of DIP joint flexion should be evaluated, both weight bearing and non–weight bearing. Passive range of motion should be determined to evaluate whether the deformity is flexible, rigid, or semirigid, which will influence treatment options. One should inspect for cutaneous lesions (corns) on both the dorsal and distal aspects of the toe. Corns may progress to ulcers with subsequent superficial or deep infection, especially in the diabetic population with neuropathy. If the patient has peripheral arterial disease, ulceration may lead to necrosis and possible toe loss.
Swelling, increased temperature, or erythema might indicate inflammatory arthritis or joint infection. The patient’s footwear should be examined to determine sufficient or insufficient toe box height to accommodate the deformity. Traditional neurologic and vascular examinations generally reveal no abnormal findings in uncomplicated mallet toe conditions.