Understanding 1st MTP OA: A Step Towards Better Foot Health

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Osteoarthritis (OA) is one of the most common forms of arthritis, affecting millions of people worldwide. Among the various joints that can be impacted, the first metatarsophalangeal (MTP) joint, located at the base of the big toe, often bears the brunt of this condition. Recent population data shows that symptomatic radiographic OA for the first MTP joint affected 7.8% of people aged 50 years and above, which makes it as prevalent as hip OA (Roddy et al., 2015).

?What is 1st MTP Osteoarthritis?

?1st MTP osteoarthritis is characterized by the degeneration of the cartilage in the first MTP joint. This joint plays a crucial role in our ability to walk, run, and perform daily activities. When the cartilage that cushions the bones in the joint wears down, it leads to pain, stiffness, and limited mobility, significantly worsening their quality of life (Bergin et al., 2012).

Bony projections, known as osteophytes, develop around the joint line, resulting in bony bumps around the big toe joint.

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Causes and Risk Factors

Understanding the causes of 1st MTP osteoarthritis is crucial for prevention and management. Some common risk factors include:

.??Age: The risk of developing osteoarthritis increases with age as cartilage naturally wears down.

·? Obesity: Excess body weight adds stress to weight-bearing joints, including the MTP joint.

·? Prior Injury: Previous injuries to the foot or big toe can predispose individuals to osteoarthritis.

·? Altered mechanics : The movement and function of the foot can also cause changes and exert pressure on the 1st metatarsophalangeal (MTP) joint.

·? Genetics: Having a family history of osteoarthritis can make individuals more prone to the condition, as the cartilage in their joints may deteriorate faster compared to others.

·??High-Impact Activities: Participation in sports or physical activities that put excessive stress on the feet can accelerate cartilage wear.

Signs and symptoms

The symptoms of 1st MTP osteoarthritis can vary in severity and may include:

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·??Pain: Often worsens with activity and improves with rest.

·??Stiffness: Particularly noticeable after periods of inactivity, such as in the morning.

·??Swelling: Inflammation around the joint can lead to noticeable swelling, and it may sometimes be accompanied by redness.

·? Reduced Range of Motion: Experiencing difficulty in bending or moving the big toe can make walking challenging and change your gait.

·??Bone Spurs: Bony growths can form around the joint, causing discomfort. Sometimes, toe deformities are also visibly noticeable, for example- Hallux rigidus.

Diagnosis

As a physiotherapist, the primary method of diagnosis involves reviewing the patient’s medical history and conducting a physical examination. Understanding the specifics of the symptoms and any relevant past injuries aids in forming a diagnosis. The physical examination includes assessing joint tenderness, swelling, range of motion restrictions, and capsular patterns to gain a better understanding of the condition.

While imaging tests like X-rays or MRIs can reveal joint space narrowing, bone spurs, and other signs of osteoarthritis, they are not always necessary for diagnosis.

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Despite its prevalence and disease burden, there is very limited evidence to guide conservative or non- surgical treatment of first MTP joint OA.?

Few options that can avoid any surgical procedure are :

·??Lifestyle modifications: Increasing physical activity and managing weight, if applicable and possible, can help reduce stress on the joints. Participating in low-impact exercises can maintain joint function without worsening the pain.

·??Physiotherapy : Manual mobilization to enhance range of motion, combined with a customized exercise program to boost strength, flexibility, and stability of the foot, can significantly alleviate pain and discomfort. If visible swelling is present, therapeutic ultrasound can be utilized to promote healing and reduce inflammation.

·? Footwear modifications and insoles : One of the most important things you can do to help is to wear the right footwear. Custom made orthotics which provides appropriate arch support and alleviate the pressure from the joint can be beneficial. A comprehensive foot scan assessment, incorporating static, dynamic, and gait measurements to understand foot mechanics, can result in comfortable and suitable orthotics.

·??Injections: ?When the pain and inflammation are the primary issues, a corticosteroid (cortisone) injection can be highly effective. Its anti-inflammatory properties offer significant pain relief.

?Another often overlooked option is hyaluronic acid injections. Recent studies have shown that patients with osteoarthritis experience very positive outcomes with hyaluronic acid, which acts as a non-drug based supplemental cartilage. It provides essential lubrication and cushioning to the joint with the anti-inflammatory properties, helping to maintain joint health and function, with almost no possible side effects.

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The corticosteroid injection can also be used as a diagnostic tool. If you get good pain? relief, it indicates that the pain is coming from that joint. If it does not give good pain relief for any period of time, this might be because other factors are causing the pain.

Surgery for 1st MTP osteoarthritis is an option when non-surgical treatments do not sufficiently alleviate your symptoms, preventing you from performing your usual daily activities, work, or hobbies.

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REFERENCES

Roddy, E., Thomas, M.J., Marshall, M., Rathod, T., Myers, H., Menz, H.B., Thomas, E. and Peat, G., 2015. The population prevalence of symptomatic radiographic foot osteoarthritis in community-dwelling older adults: cross-sectional findings from the clinical assessment study of the foot.?Annals of the rheumatic diseases,?74(1), pp.156-163.

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Bergin SM, Munteanu SE, Zammit GV, Nikolopoulos N, Menz HB. Impact of first metatarsophalangeal joint osteoarthritis on health-related quality of life.?Arthritis Care Res.?2012;64:1691–1698. doi:?10.1002/acr.21729.

Allan, J.J., McClelland, J.A., Munteanu, S.E., Buldt, A.K., Landorf, K.B., Roddy, E., Auhl, M. and Menz, H.B., 2020. First metatarsophalangeal joint range of motion is associated with lower limb kinematics in individuals with first metatarsophalangeal joint osteoarthritis.?Journal of Foot and Ankle Research,?13, pp.1-8.

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Menz, H.B., Roddy, E., Marshall, M., Thomas, M.J., Rathod, T., Myers, H., Thomas, E. and Peat, G.M., 2015. Demographic and clinical factors associated with radiographic severity of first metatarsophalangeal joint osteoarthritis: cross-sectional findings from the Clinical Assessment Study of the Foot.?Osteoarthritis and cartilage,?23(1), pp.77-82.