Hallux Valgus

Question 1

What is hallux valgus

Answer 1

A deformity of the first MTPJ

Colloqually called a bunion.

Question 2

Epidemiology

Answer 2

One of the most common foot problems in adults

Prevalence of around 35% in those aged 65 or more

More common in women

Question 3

During the gait cycle the digits should remain parallel to the long axis of the foot.

What makes this possible?

Answer 3

A balance of static stabilisers (bones and ligaments) and dynamic stabilisers (muscles and tendons).

Question 4

Why is the 1st MTPJ most susceptible to valgus angulation?

Answer 4

It is unstable as it heavily relies on the stabilising structures of the foot.

This means that if a static or a dynamic stabiliser becomes disrupted the 1st MPTJ is most susceptible to deformity.

Question 5

What happens to the big toe when the intrinsic stabilisers loses their control?

Answer 5

The extrinsic tendons become a deforming force leading to medial drift of the metatarsal head.

Question 6

Risk factors

Answer 6

Female

Connective tissue disorder

Hypermobility syndromes

Flat foot

High heels

Narrow-fitting footwear

Question 7

Clinical features

Answer 7

Painful medial prominence aggravated by walking, weight-bearing activities or wearing narrow toed shoes.

Question 8

Examination findings

Answer 8

Medial deviation of 1st MTPJ + lateral deviation +/- rotation of the hallux with associated joint subluxation.

Inflammation and skin breakdown can be present

The foot should be assessed in both a non-weightbearing position and a weightbearing position.

Assess active and passive range of motion + crepitus to check for cartilage breakdown.

There might be contracture of extensor hallucis longus in longstanding joint subluxation and there might also be excessive keratosis on the foot.

Question 9

Dx

Answer 9

Gout

SA

Hallux rigidus

OA

RA

Question 10

Ix

Answer 10

Main investigation is X-ray and often useful to assess the degree of lateral deviation and signs of joint subuxation as well.

Question 11

What confirms a diagnosis of hallux valgus?

Answer 11

Lateral deviation is measured as the angle between the first metatarsal and the first proximal phalanx.

Any angle greater than 15 degrees confirms diagnosis.

Question 12

Severity of hallux valgus

Answer 12

Mild = 15-20 degrees

Moderate = 21-39 degrees

Severe = >40 degrees

Question 13

Conservative management

Answer 13

Sufficient analgesia

Adjusting footwear to prevent deformity and further deterioration and preventing skin irritation.

If the patient has flat feet -> Orthosis

Physio for stretching and gait re-education

Question 14

If a patient is severly impacted by the condition surgical interventions can be done.

There are a variety of procedures.

Answer 14

Chevron procedure

Scarf procedure

Lapidus procedure

Keller procedure

Question 15

Explain Chevron

Answer 15

V-shaped osteotomy of distal first metatarsal.
This allows the first metatarsal to be shifted laterally back into normal alignment.

This is then fixed by pins and screws.

Used in mild deformities

Question 16

Explain Scarf procedure

Answer 16

Longitudinal osteotomy within the shaft of first metatarsal.

Distal portion is moved laterally and fixed with two screws.

Used in moderate to severe disease

Question 17

Explain Lapidus procedure

Answer 17

Base of first metatarsal and medial cuneiform are fused.

Often useful if there is an underlying tarsometatarsal joint hypermobility

Question 18

Explain Keller procedure

Answer 18

Incision made over 1st MTPJ and joint capsule is opened to expose the joint.

Joint surfaces are removed for a space to be left that is stabilised by suturing of the surrounding tissues and subsequent scar tissue.

Common when there is severe MTPJ arthritis

Question 19

Surgical complications

Answer 19

Wound infection

Delayed healing

Nerve injury

Osteomyelitis

Question 20

Complications

Answer 20

Avascular necrosis

Non-union displacement

Reduced range of motion

Prognosis is variable