Mallet Toe: Understanding and Treatment Options
Mallet toe is a common deformity of the lesser toes, specifically affecting the distal interphalangeal joint (DIPJ). This condition involves the flexion of the distal phalanx over the middle phalanx, often due to a contracture at the DIPJ. Mallet toe can vary in severity, with some cases showing an inability to fully extend the toe, resulting in pain and difficulty wearing shoes. While not as prevalent as other toe deformities like hammertoe or claw toe, mallet toe still represents a significant challenge in foot and ankle surgery.
Causes and Pathophysiology
The exact causes of mallet toe deformity are multifactorial. One of the primary factors is an imbalance between the flexor and extensor muscles controlling the toe. The flexor digitorum longus (FDL) is a key extrinsic muscle responsible for plantar flexion at the DIPJ, and when it overpowers the extensor muscles, the toe becomes fixed in a flexed position. A longer second or third toe relative to the adjacent digits can exacerbate this imbalance, especially when tight or narrow footwear is worn. This condition is particularly prevalent in Western societies, where high heels and restrictive shoes are commonly worn.
Trauma is another significant contributor to mallet toe. Direct injuries to the toe, such as stubbing or a hyperflexion injury, can damage the tendons, leading to the deformity. Additionally, inflammatory conditions like rheumatoid arthritis or psoriatic arthritis may also predispose individuals to developing mallet toe, as joint destruction and muscle imbalances further complicate toe alignment.
Symptoms
Mallet toe is primarily characterized by pain and deformity. The affected toe is often flexed at the DIPJ, leading to pressure on the tip of the distal phalanx, which can cause corns or calluses to form. Pain is typically located at the dorsum of the DIPJ and can worsen with prolonged weight-bearing or tight footwear. In some cases, patients seek treatment for cosmetic reasons, especially if the deformity is visible when the foot is in a resting position. Chronic pressure on the nail bed may also result in nail deformities.
Conservative Treatment Options
The first step in managing mallet toe is determining whether the deformity is flexible or rigid. Flexible deformities can often be managed conservatively with modifications in footwear and non-surgical interventions. The use of shoes with wider toe boxes and soft soles can help alleviate pressure on the affected toe. Palliative treatments such as padding or cushioning over calluses and corns are also effective for symptom relief. Additionally, splints or toe crests may be used to reduce flexion at the DIPJ and promote better alignment.
Stretching the flexor tendons regularly can help delay the progression of the deformity in flexible cases. For patients with diabetes or peripheral vascular disease, conservative treatments should be pursued carefully to avoid exacerbating existing foot complications, such as skin breakdown or ulceration. In more severe cases, when conservative measures fail, surgical intervention may be considered.
Surgical Treatment Options
For patients with rigid or more severe deformities, surgical treatment becomes necessary. Several techniques are employed to correct mallet toe, each chosen based on the specific needs of the patient.
1. Flexor Tenotomy
Flexor tenotomy is a widely used surgical procedure that involves cutting the flexor tendon to relieve the flexion deformity at the DIPJ. This procedure is most effective in cases where the deformity is flexible and can be corrected without the need for additional bony procedures. The surgery is typically performed under local anesthesia, and a small incision is made on the plantar surface of the toe to access the flexor tendon. After the tendon is severed, the toe is allowed to realign. In some cases, a Kirschner wire (K-wire) is used to stabilize the toe while the wound heals.
2. Hemiphalangectomy/Condylectomy
In cases where a simple tenotomy is insufficient, a hemiphalangectomy, or condylectomy, may be performed. This procedure involves the removal of the damaged or deformed portion of the middle phalanx or distal phalanx. While this technique has been used with good results for other deformities like hammertoe, it is less commonly used for mallet toe due to the potential for fibrous union rather than bony fusion. The procedure requires careful removal of bone and soft tissue to ensure proper alignment, followed by stabilization with pins or screws.
3. DIPJ Resection Arthroplasty/Arthrodesis
For more severe cases where the joint is extensively damaged or where other procedures have failed, a resection arthroplasty may be performed. This procedure involves the removal of the joint surfaces at the DIPJ to promote healing and fusion. In some cases, arthrodesis (joint fusion) is performed to ensure permanent stabilization. While this technique offers good pain relief, it may result in reduced joint mobility, making it less desirable for patients seeking full toe function.
4. Distal Phalangectomy
Distal phalangectomy is a more radical option, typically reserved for older patients or those with significant comorbidities. In this procedure, the distal phalanx is amputated, effectively removing the affected toe portion. While this may offer excellent pain relief and is typically used for advanced cases, it does result in the loss of the toe tip, which can affect foot aesthetics and function.
Conclusion
Mallet toe is a challenging foot deformity that requires careful diagnosis and treatment. Advances in both conservative management and surgical techniques have greatly improved outcomes for patients. For flexible deformities, conservative treatments such as footwear modifications and tendon stretching are often sufficient. However, in cases where these measures fail or the deformity is severe, surgical options such as flexor tenotomy, hemiphalangectomy, and DIPJ arthrodesis offer reliable solutions. As with any foot deformity, early intervention is key to achieving the best possible outcomes and preventing further complications.
Dr. Mo Athar
