What causes Metatarsophalangeal (MTP) Joint Pain?
Certain risk factors can increase the risk of metatarsophalangeal joint pain:
- Anatomical deformities of foot such as pes cavus, ankle equinus and Achilles tendon deformities.
- Chronic inflammatory conditions of metatarsal joints (especially rheumatoid arthritis).
- Poor choice of footwear or unhealthy lifestyle.
What are some common causes of Metatarsophalangeal Joint Pain?
- Calluses: This is the most frequent cause of metatarsalgia and is also referred to as plantar calluses. These are mainly due to abnormal weight bearing and chronic exposure to pressure that results in inflammation of metatarsal head.
- Morton’s Neuroma: Morton’s neuroma is an entrapment neuroma of the plantar interdigital nerve. The pathophysiology of Morton neuroma revolves around persistent or ongoing irritation due to a narrow or poor choice of footwear leading to fibrosis of interdigital nerve and disturbing symptoms of pain, paresthesia and numbness. Third and fourth interdigital spaces are usually involved and diagnosis is mainly clinical.
- Mechanical disorders of MTP joint: Metatarsophalangeal joint pain (also referred to as metatarsalgia) can also be due to surface misalignment of connective tissue framework, resulting in a misalignment or subluxation of joints, plate tears or destruction of joint cartilage. The misalignment of joints can also lead to swelling and even permanent destruction of joints. The disease process most frequently involves the second metatarsophalangeal joint.
- Stress Fracture. The most common mechanical cause of MTP joint pain is stress fracture (especially of 3 and 4th metatarsal due to limited mobility). The diagnosis of stress fracture is tricky, since radiological examination is usually inconclusive.
- Capsulitis. Click here.
- Foot deformities such as hammer toe. A hammer toe or contracted toe is a deformity of the proximalinterphalangeal joint of the second, third, or fourth toe causing it to be permanently bent, resembling a hammer. Mallet toe is a similar condition affecting the distal interphalangeal joint.
Other less common causes are:
- MTP Arthritis: Morning stiffness, joint rigidity and pain on weight bearing are some signs that are strongly suggestive of early rheumatoid arthritis.
- MTP Synovitis: In osteoarthritic synovitis, patients present with swelling and localized warmth. In cases of inflammatory arthropathies, patients also reports swelling, warmth and redness with severe limitation of joint mobility due to pain and stiffness.
The diagnostic process involve two key elements:
- Clinical evaluation: by a clinician experienced in foot pain. This comprises of a careful history taking and clinical examination. The Squeeze Test: This involves squeezing all the MTP joints together softly. If this causes pain, it suggests underlying joint inflammation.
- Radiological evaluation: Xray, CT or MRI assessment to confirm the clinical diagnosis and to identify concurrent issues.
Management and Treatment:
Treatment mainly revolves around the primary disease process. Injecting local anesthetic solution or corticosteroid can help to reduce inflammation.
Management also involves:
- Orthotics: Orthoses are ideally recommended in the long term management of metatarsophalangeal joint pain. Custom-designed orthotics are helpful in relieving stress and pressure from the joints. Doctors recommend orthotics to correct the unusual bone and foot alignment. Modification of orthotics can also improve the motion of metatarsophalangeal joint and relieve pain.
- Rest and relaxation: It is very important to limit the physical motion or activity in order to control the symptoms and to hasten the recovery.
- Physical therapy and rehabilitative exercises: Controlled activity and carefully executed exercises help in tissue remodeling processes and ensure optimal connective tissue conditioning to shorten the duration of ailment.
- Surgery is a last resort.
- Powless, S. H., & Elze, M. E. (2001). Metatarsophalangeal joint capsule tears: an analysis by arthrography, a new classification system and surgical management. The Journal of foot and ankle surgery, 40(6), 374-389.
- Fink, B. R. (2011). Steps to take in managing metatarsalgia. Journal of Musculoskeletal Medicine, 28(9), 346.
- Guimarães, M. C., Yamaguchi, C. K., Aihara, A. Y., Hartmann, L. G., Pröglhöf, J., & Fernandes, A. D. R. C. (2006). Metatarsalgias: differential diagnosis with magnetic resonance imaging. Radiologia Brasileira, 39(4), 297-304.