Bunion, commonly known as bigfoot, is the most common foot deformity. According to foreign statistics, the prevalence of bunion is 3% in people aged 15-30 years, 9% in people aged 31-60 years, and 16% in people older than 60 years. The bunion deformity is mainly manifested by the lateral tilt of the bunion, the inversion of the first metatarsal, the increase of the angle between the first and second metatarsals, the subluxation of the metatarsophalangeal joint, and the formation of a bone superfluous on the inside of the first metatarsal head. After long-term abrasion by shoes, the local skin will thicken and become red and inflamed in severe cases, forming a “bunion”. When the bunion is severe, the second toe can be squeezed to the dorsal side by the bunion, forming a hammer finger. At the same time, due to the outward shift of the main weight-bearing area of the forefoot, the weight-bearing of the second and third metatarsal heads increases, resulting in the formation of plantar callus with pain, which is known as “metastatic metatarsalgia”. In addition, the presence of bunion deformity increases the stress load on the lateral metatarsal bones and makes the trabecular structures vulnerable to cumulative stress, which can cause fatigue fractures in the lateral metatarsal bones due to excessive stress concentration. Bunion patients have limited dorsiflexion of the bunion, and the body compensates for this by adjusting the activities of other parts during walking, which in turn often leads to lesions of the knee and lumbar spine, seriously affecting health. Therefore, we need to pay attention to the bunion deformity and severe bunions require the necessary surgical intervention to restore the normal foot biomechanics. A good surgical procedure will not only relieve pain but also restore as much normal foot shape as possible, thus bringing harmony between function and aesthetics. Zheng Yuxin, Orthopedic Department of Shanghai Shuguang Hospital East Hospital, causes of bunion: bunion deformity is mostly seen in women, the ratio of men to women is about 1:40. There are many causes of bunion, about half of them are related to genetic factors, the mother has bunion, the prevalence of children increases significantly. Since women have weaker ligaments in their feet than men, they are more likely to develop bunions under the same genetic conditions. In addition, the flexibility of the ligaments decreases with age, which is why bunions are more common in middle-aged and older women.
Other common causes of bunions are: (1) shoe wearing habits. Women often wear high-heeled shoes, pointed shoes, the whole body weight is easily concentrated in the front of the foot, pointed shoes often force the forefoot forced squeezed in a narrow triangular area, making the toes in a long-term abnormal state, in the long run will gradually form bunion deformity. (2) Increased mobility of the bunion, the first metatarsal, and the first metatarsal row where the medial cuneiform bone is located. (3) Structural abnormalities of the foot. Other structural abnormalities include overlength of the first metatarsal, inversion of the first metatarsal, and bunion rotation front deformity. (4) Joint inflammation. Rheumatoid arthritis, gout and other pathologies tend to disrupt the normal balance structure of the soft tissues and bone joints of the foot, resulting in bunion deformity due to the combined effect of various internal and external factors. (5) Others. Trauma, cerebral palsy and other causes of neuromuscular lesions often cause imbalance of the soft tissue muscles of the foot, especially the first metatarsophalangeal joint, which can also produce bunions.
Clinical manifestations of bunions: Pain is the main symptom of bunions, and the presence of bunion deformity and painful medial bunions of the first metatarsophalangeal joint are the main clinical manifestations. However, the degree of deformity is not directly proportional to the pain, and pain is not necessarily present when the deformity is obvious. In addition to pain caused by bunions, other signs such as hammertoes of the second and third toes and plantar callus are also important in producing painful symptoms. The x-ray presentation varies with the severity of the disease.
Pain: (1) pain caused by bunions (2) pain caused by hammertoes (3) pain caused by plantar calluses (4) pain caused by stress concentrations in the lateral metatarsals (5) pain in the knee, hip and lumbosacral region caused by postural compensations.
Deformity: bunion, inversion of the first metatarsal, medial bones of the first metatarsophalangeal joint, hammertoe of the second and third toes, etc.
X-ray: the first metatarsophalangeal joint is semi-dislocated, the bunion is displaced to the midline, the bunion angle is >15 degrees, and the angle between the first and second metatarsals is >10 degrees as the basic manifestation.
According to the clinical manifestations and X-ray changes, the development of bunion can be divided into three stages: (1) Early stage: symptoms are mild, pain is not serious, and there is no subluxation of the first metatarsophalangeal joint on X-ray. (2) Middle stage: the bunion deformity is obvious, the bunion pain is more severe, and the x-ray shows the bunion proximal joint is semi-dislocated to the lateral side, and the second toe hammer deformity appears. (3) Late stage: In addition to bunion pain, the metatarsophalangeal joint is swollen and painful, and osteoarthritis is seen in the metatarsophalangeal joint on X-ray.
Treatment of bunion: conservative treatment and surgical treatment.
Conservative treatment: Only applicable to early stage patients.
1. Non-specific treatment: rest, reduced activity, and wearing loose shoes can reduce pain. Topical drugs such as fotarine can be applied locally when pain is present, or non-steroidal anti-inflammatory and analgesic drugs such as Cilazol can be taken orally. Hot compresses and physical therapy are also effective. Sometimes local closure of the painful area is also possible. However, most conservative treatments are symptomatic but not causative, and cannot fundamentally relieve pain, and are prone to relapse after a period of time.
2.Wearing orthopedic brace: There are many kinds of braces for bunion correction, and different types and degrees of bunions need different types of braces. Usually wear braces at night and insist on 8 hours a day for 3 months, which can reduce the pain symptoms to some extent and slow down the development of further deformation of the bunion.
Surgery: Once a bunion causes persistent pain or severe deformity, surgery is required. Surgery can reduce the pain and correct the deformity to improve the function of the foot. Purpose of surgery: The primary purpose is to relieve pain. Treatment goals: (1) correction of the bunion deformity; (2) removal of the hyperplastic bones and bursa; (3) correction of the first metatarsal inversion and repositioning of the seed bone system; (4) adjustment of the metatarsal head weight bearing and correction of combined deformities (callus, hammertoe, etc.); and (5) stabilization of the first metatarsal row.
The surgical treatment itself is less invasive, and surgery can be considered for those with severe pain. There are many surgical methods, and it is important to choose the appropriate method according to the degree of deformity. In addition, the surgery is very skillful, such as the operation is not fine will affect the overall effect, and then the equipment used for surgery should also be fine, because the skin of the foot is thin, it is generally recommended to use imported small plates and screws, some domestic plates and screws are too big and too thick, which will affect the efficacy of the surgery. Therefore, it is important to choose an experienced surgeon. The following are some specific surgical methods introduced.
1.Soft tissue surgery This type of surgery aims to correct the bunion angle (HVA) and is represented by the McBride surgery and has been modified by several scholars. The main components of the surgery are the severance of the contracted bunion muscle at the stop of the lateral base of the bunion, resection of the medial tuberosity of the first metatarsal, lateral release of the bunion capsule, and medial tightening. The efficacy of this procedure alone is more certain in mild bunions without enlargement of the first and second intermetatarsal angles (IMA). For bunions with significant IMA enlargement, this procedure usually needs to be used in combination with other osteotomies.
2.Osteotomy bunions: Used to correct bunions with an increased interphalangeal joint.
First metatarsal neck osteotomy: There are more of these surgical methods, mainly Austin and Mitchell, and they have been repeatedly modified. The purpose of the procedure varies slightly from procedure to procedure and is primarily to correct excessive valgus of the IMA and the first metatarsal head. This type of surgery has good results for mild to moderate bunions. However, in cases where the deformity of the first metatarsal is more pronounced, this type of surgery cannot achieve perfect orthosis.
First metatarsal base osteotomy: In cases with significant IMA enlargement, first metatarsal base osteotomy can effectively correct IMA, and can also correct the elevation and internal rotation deformity of the first metatarsal by rotating back and depressing the metatarsal head, which can effectively restore the shape of the transverse arch of the foot. There are various methods of first metatarsal osteotomy, such as “V” (chevron) osteotomy, transverse osteotomy and curved osteotomy. However, in cases where the joint surface of the first metatarsal head is obviously turned out, only correcting the inversion of the first metatarsal can increase the joint surface of the first metatarsal head turned out, so the first metatarsal neck osteotomy can be added to correct the situation.
The Mayo procedure is the preferred procedure for bunion cases that only show bunion swelling.
4, joint fusion first metatarsophalangeal joint fusion: severe joint lesions, joint instability can be considered. clutton believes that metatarsophalangeal joint fusion in a good position is a permanently satisfactory treatment and emphasizes the importance of internal fixation, it is generally accepted that a good joint fusion must be.
1, have good cancellous bone contact surfaces.
2, The bunion is fixed in a functional position.
3, Have strong internal fixation and be able to bear weight early.
4.Fast functional recovery.
The metatarsophalangeal joint fixation position is generally considered to be 20-30 in dorsiflexion as the most appropriate, and greater than 30 will produce metatarsal pain syndrome, which will achieve the desired results in the short term after surgery. fitzcra1d reported that the postoperative period also allowed participation in sports activities with a success rate of 90%, but produced painful arthritis of the interphalangeal joint in 10% of cases during long-term follow-up.
First metatarsal cuneiform fusion: It should be used in more severe bunions, overactive first metatarsal cuneiform joint, severe painful plantar callus and collapse of the transverse and longitudinal arches of the foot, and is a more efficacious surgical procedure.
5.Arthroplasty of the first metatarsal phalangeal joint: the Keller procedure to remove the proximal end of the proximal phalangeal bunion is still respected by some scholars. For elderly bunion patients whose pain is mainly caused by severe bunion arthritis, the Keller procedure is relatively simple and can indeed solve the pain of some patients, but because the Keller procedure shortens the bunion, the plantarflexion of the bunion, which has already lost some of its function, is further reduced, which will aggravate the pain of the plantar base. This type of surgery should be avoided or strictly indicated.
First metatarsophalangeal joint prosthesis replacement: Due to the serious shortcomings of joint fusion and the Keller procedure, and the successful use of major joint arthroplasty in recent years, the development and use of artificial prostheses for the foot and hand has been promoted. Artificial arthroplasty of the first metatarsophalangeal joint can provide good function after bunion surgery, prevent recurrence of deformity, and be painless after surgery. The following points should be noted during the artificial joint replacement.
1. Local skin is intact, bone support exists and extension and flexion muscle kinetics are intact.
2. Surgical operation should be meticulous.
3.Surgical instruments should be matched.
4.Soft tissues should not be injured.
5.Good postoperative drainage should be available.
6.Intraoperative and postoperative application of prophylactic antimicrobial agents.
7.Postoperative fixation on the force line.
8.Persons who have had septic arthritis are contraindicated.