What is metatarsal-phalangeal joint osteoarthritis (MTP joint OA)?
Osteoarthritis of the MTP joint is the name given to arthritis which gives pain in the “big toe joint”. This also causes the affected joint to become stiff.
The process of osteoarthritis involves wearing or thinning of the smooth cartilage joint surfaces as well as stiffening to the soft tissue surrounding the joint. Swelling, inflammation and pain are potential consequences.
Several factors normally combine to cause symptoms of osteoarthritis:
- Previous joint damage (from trauma or other conditions such as such as gout and rheumatoid arthritis)
- Increased bodyweight
- Age (risk increases with age)
- Family history (genetics)
- Poor ankle-foot alignment (termed biomechanics) such as a flat foot posture
General exercise such as walking, cycling and playing sports does not increase the risk of developing, or the rate of deterioration of, MTP joint OA.
Pain is felt primarily across the top and sometimes the inside of the MTP joint (the base of the big toe). Often there is a significant stiffness or deviation of the joint, which may be the first noticeable symptoms. Fortunately, the presence of MTP joint osteoarthritis does not always cause pain so it is quite possible to be pain free despite reasonably advanced arthritis. In addition, the joint undergoes a “wear and repair cycle” so pain can improve with appropriate treatment.
How is MTP joint OA diagnosed?
MTP joint OA can be reliably diagnosed by your doctor or physiotherapist by taking a history of your condition and by conducting a physical examination.
The main feature on examination is often a reduced range of movement.
X-rays are not routinely required but may be requested if symptoms are severe enough that surgery is being considered.
How is MTP joint OA treated?
In the majority of cases, the symptoms of MTP joint OA can be managed effectively by non-invasive measures as described below:
Footwear. The most effective measure is wearing appropriate footwear including wearing wider fitting shoes.
Orthotics. Appropriately supportive insoles can improve symptoms.
Exercises. Regular exercises to maintain flexibility to the ankle and foot:
Using painkillers when needed. Over-the-counter analgesia is available through pharmacies when needed. Paracetamol is most commonly prescribed. Anti-inflammatories, such as Ibuprofen, can be used, but as there is little or no inflammation involved in osteoarthritis these are best avoided without discussing with your GP. Side effects are even more common than with paracetamol so please ensure to take appropriate medical advice. There is a good booklet on the Arthritis Research UK website with information about the various drug options.
Corticosteroid injection therapy. For individuals with relatively early-stage MTP joint OA who continue to suffer disabling symptoms in spite of a course of other non-surgical measures as management (outlined above), or for patients who are unable to commence a supervised exercise program due to pain levels, a corticosteroid injection can may be offered as the next line of treatment. You can read more about local corticosteroid injections here.
MTP joint debridement, fusion or MTP joint replacement surgery can be effective options for patients with advanced stage MTP joint OA who:
- Have trialed a course of non-surgical management without success
- Have consistent, disabling pain significantly limiting mobility
- Have a satisfactory Body Mass Index (BMI) or have made lifestyle changes to lose excess bodyweight
It normally takes 6-8 weeks following foot surgery for patients to resume wearing normal footwear.
Further information about Osteoarthritis – Arthritis Research UK