• Definition
• Incidence
• Pathogenesis
• Clinical Presentation
• Joint Fluid Analysis Findings
• Useful Lab Tests/Studies
• Radiographic Findings
• Morphological Changes
• Differential Diagnosis
• Impact of Disease
• Treatment

Hallux limitus describes a condition in which there is limitation of motion of the 1st metatarsal phalangeal joint in the sagittal plane. Hallux limitus is the inability of the hallux to dorsiflex at the 1st MPJ. This limited range of motion results in jamming of the 1st metatarsal phalangeal joint (1st MPJ). Over time, repetitive jamming will contribute to arthritis of the 1st MPJ. The most characteristic sign of hallux limitus is a bump (exostosis) on top of the head of the 1st metatarsal. In fact, many doctors also refer to hallux limitus as a dorsal bunion.

Incidence

Ages 30 to 50 years old, men and women equally. Tends to occur in the pronated foot.

Pathogenesis

Hallux limitus is caused by four contributing factors. These factors include the following:

1. A long 1st metatarsal.
2. An elevated 1st metatarsal. (Metatarsus primus elevatus)
3. An impaction injury (trauma) of the 1st MPJ resulting in an osteochondral defect (OCD) of the joint.
4. Systemic diseases that cause injury to the joint such as rheumatoid arthritis, lupus, or gout.

Patient usually presents with pain in the bottom of the 1st MPJ where a callous can develop due to the toe not bending upward enough. Another consequence of the jamming of the 1st MPJ is the development of spurs on the top of the joint, which can become painful as a result of shoe pressure. Evaluation of the range of motion of the 1st MPJ can be performed in two positions; relaxed and functional. In a relaxed position, with no resistance exerted by the calf, the 1st MPJ shows normal range of motion without pain. In a functional position, when resistance is applied by the calf, the range of motion of the 1st MPJ changes and hallux limitus can be more appropriately assessed. The term functional hallux limitus is applied to cases that have normal range of motion in a relaxed position, but decreased range of motion in a functional position.

Joint Fluid Analysis Findings

Non-inflammatorty, but can be used to rule out differentials

Useful Lab Tests/Studies

Diagnosis is made by performing a physical exam of the foot and the use of x-rays. Physical exam will reveal pain and limitation in motion of the 1st MPJ. The motion at the 1st MPJ is less than 65 degrees dorsiflexion. There is commonly mild swelling and bony prominences associated with the 1st MPJ. X-rays of the foot will reveal the true severity of the patient’s condition. It will allow the physician to evaluate the joint for bone spurs, decrease in joint space, flattening of joint surfaces, and loose bodies in the joint. X-rays can also reveal the cause of hallux limitus such as an elongated or elevated 1st metatarsal.

Radiographic Findings

Uneven joint space narrowing, at the site of abnormal applied force. Subcondral sclerosis (Eburnation) adjacent to the site of the joint space narrowing, can be more diffuse in severe cases. Osteophytosis, typically at the margins of the affected joint, can be an isolated finding absent of joint space narrowing or subchondral sclerosis. Subchondral cyst in affected joint. Loose osseous body in affected joint. The loose body appears as a bone fragment or ossicle within the joint. It can be the initiating factor and caused by trauma, or it could be a fractured osteophyte in an already existing osteoarthritic joint. These 5 finds are also found in osteoarthritis which is essentially what hallux limitus is.

Morphological Changes

Narrowing of joint spaces and break down of cartilage, formations of cysts and exostosis of the bone around areas of cartilage that have been broken down due to increased pressure. Sclerosis of subchondral bone in response to increased pressure on an area. Progressively get worse as the disease progresses to hallux rigidus.

Differential Diagnosis

Osteoarthritis, Gout, Pseudogout, Rheumatoid arthritis, Lupus, septic arthritis, sesamoiditis, and sesamoid fractures.

Impact of Disease

Patient will have decreased ambulation due to the pain and limitation of motion at the 1st MPJ and therefore have a decreased quality of life.

Treatment

Conservative- anti-inflammatories, physical therapy, ice, MPJ ROM exercises once painful symptoms resolve, strapping to reduce motion of joint, padding, shoe gear with stiff soles, orthotic control. Long term conservative treatment is usually not very effective. Patients who do not respond to conservative treatment (especially patients with Hallux Rigidus) require surgery. One example of surgery preformed is a bunionectomy with an implant. The arthritic part of the bone and joint is removed and replaced with an implant.