What Is the Metatarsophalangeal Joint?

Metatarsophalangeal joint. The first to fifth metatarsophalangeal joints belong to the forefoot, and are composed of 5 metatarsal heads and the base of the metatarsophalanges of their proximal segments. Because the metatarsophalangeal joints often flex and extend simultaneously during exercise, they are collectively referred to as metatarsophalangeal joints.

Metatarsophalangeal joint. The first to fifth metatarsophalangeal joints belong to the forefoot, and are composed of 5 metatarsal heads and the base of the metatarsophalanges of their proximal segments. Because the metatarsophalangeal joints often flex and extend simultaneously during exercise, they are collectively referred to as metatarsophalangeal joints.

Chinese name

Metatarsophalangeal joint

Foreign name

metatarsophalangeal joint

Belong to

Elliptical joint

Can be

Flexion and extension

Metatarsophalangeal joint auxiliary structure

The metatarsophalangeal joint capsule is loose, with lateral collateral ligaments strengthened on both sides, and metatarsal collateral ligaments on the metatarsal plane. The zygomatic collateral ligament is hypertrophic, located between the collateral ligaments on both sides, and is loosely connected to the sacrum. It is tightly connected to the phalanges, deep transverse ligaments of the sacrum, and lateral collateral ligaments. There is a zygomatic deep transverse ligament (sacral small ligament transverse ligament) between the 1st to 5th metatarsal heads. When transplanting the second toe, the severed transverse sacral ligament must be sutured, otherwise the transverse arch of the foot will collapse and cause pain. .

Metatarsophalangeal joint movement

As far as the form of movement is concerned, the metatarsophalangeal joint is an elliptical joint, which can flex (hook toes) and extend (extend toes) around the coronary axis, and perform slight abduction (pentacostal deployment) and adduction (about phalangeal) around the sagittal axis. The five toe bones are moved together, in which the first metatarsal head and the fourth and fifth metatarsal heads become the front support points of the medial and lateral longitudinal arches, which plays a role in maintaining the support of the soles of the foot, especially the stability of the kick. Metatarsophalangeal joint dorsiflexion can reach 90 °. Due to the limitation of ligaments and tendons, plantar flexion of the first metatarsophalangeal joint is about 30 °, and the other 4 toes can reach 50 °. The first metatarsophalangeal joint has a valgus angle when it is normal. This angle is formed by the intersection of the axis of the first metatarsal bone with the axis of the proximal phalangeal bone. This angle is generally considered to be 15 ° to 20 °.

Development of Metatarsophalangeal Joint Motor Function

1. For the flexion of the foot, such as running and jumping, the final action must be in the metatarsophalangeal joint: the ankle joint plantar flexor cooperates with the toe flexor muscle to contract under far-fixed conditions to complete the metatarsophalangeal joint extension. motion. The effect of the metatarsophalangeal joint on foot movements cannot be ignored, and its flexion and extension characteristics can have an important impact on the running and jumping movements of the human body, especially the support of the kicking effect at the later stage.

2. Sneakers with proper flexion and extension stiffness will not change the flexibility of the forefoot, but can also help improve the efficiency of pedaling. This requires that the flexion and extension stiffness of the metatarsophalangeal joint itself is highly consistent with the stiffness of the sneaker. It can be seen that sports shoe designers should work with experts in the fields of sports science, materials science and ergonomics to find the relationship between soles, upper flexion and extension positions and optimal flexion and extension stiffness when stepping on the ground to ensure that sports shoes are protected against damage and Sports performance maximizes both aspects.

3. Prospect: At this stage, how to improve the mechanical effect of the metatarsophalangeal joint flexion and extension, effectively reduce the energy absorption of the metatarsophalangeal joint, and finally achieve the goal of improving fatigue and improving sports performance has become the key to exploring the function of the metatarsophalangeal joint. In addition, through additional intervention factors, such as the change in flexion and extension stiffness of the metatarsophalangeal joint and long-term training of the metatarsophalangeal joint, it can indeed change the mechanical characteristics of the lower joints and affect the absorption and utilization of joint energy. A series of problems such as increasing sports performance, reducing and preventing possible sports injuries are still unclear.

It can be seen that the new features and new theories of the motor function and biomechanical characteristics of the metatarsophalangeal joint, including the relationship with energy contribution and athletic ability, have opened up new directions for understanding and optimizing the development of human movement. This further extends to the development of related training theories, sports equipment and sports equipment.

Metatarsophalangeal joint clinical technology and application

1. Metatarsophalangeal joint disease often manifests as limited function, severe pain, and appearance deformity. Metatarsophalangeal joint replacement can effectively solve these clinical symptoms.

2. Indications: Metatarsal head ischemic necrosis (Freiberg disease), which occurs in the second metatarsal bone. Metatarsophalangeal joint replacement can be performed for patients with Smillie stage III (toe bone cartilage collapse, metatarsal cartilage intact) and severe palpitation. Metatarsophalangeal joint replacement surgery has good effects such as alleviating plantar pain and increasing the mobility of the metatarsophalangeal joint. Patients with metatarsophalangeal osteoarthritis pain, age, and imaging grades are important factors for whether or not to undergo metatarsophalangeal joint replacement. Preoperative overall conditions and prognosis of patients should be strictly evaluated. As an autoimmune arthritis, rheumatoid arthritis is mainly manifested in the destruction of polyarticular bones of the extremities. For patients with rheumatoid arthritis with severe forefoot deformity or imaging showing severe metatarsophalangeal joint bone destruction, metatarsophalangeal joint replacement can be considered.

3. Contraindications: Decreased bone mass in patients with osteoporosis not only affects osteotomy and prosthesis implantation during metatarsophalangeal joint replacement surgery, but also reduces the biological growth characteristics of bone tissue to the prosthesis after surgery. Increasing the risk of joint and peripheral fractures during and after surgery. Severe diabetes often causes delayed healing of the surgical incision, especially foot surgery should be treated with caution. For patients with congenital foot diseases such as congenital metatarsophalangeal joint dislocation and polio, clinical surgery is still mainly based on metatarsophalangeal joint fusion and metatarsophalangeal arthroplasty.

4. Complications The complications of metatarsophalangeal joint replacement are related to many factors such as the experience of the surgeon, the surgical method, and the type of artificial joint. Similar to arthroplasty in other parts, metatarsophalangeal joint replacement has complications such as infection, pain, limited function, and loosening of the prosthesis.

Metatarsophalangeal joint replacement surgery can effectively solve the problems of patients with metatarsophalangeal joint pain and limited mobility. It has good patient satisfaction and is an ideal choice for surgery for metatarsophalangeal joint diseases.