The subtalar joint, located below the ankle between the talus bone and the calcaneus bone, is the first joint of the foot. Together with the knee, the subtalar joint plays a fundamental role in the cushioning of the weight of the body, with the supports or impacts, when walking, running or jumping.
The most common cause is traumatic injury, either from repetitive microtrauma or from a fracture of the calcaneus or the body or tail of the talus. The posterior part of the joint (posterior subtalar) is most frequently affected.
Other causes are autoimmune diseases such as rheumatoid arthritis, infections, sequelae of calcaneal fractures, uncorrected congenital deformities of the position of the talus or calcaneus, or posterior tibial tendon dysfunction.
Clinical picture
Patients with symptomatic hindfoot osteoarthritis often complain of pain, swelling and stiffness in the back of the foot and in the lateral and posterior ankle area, which worsens with walking on uneven ground, running or sports. The pain usually improves with rest or with the use of special shoes.
Diagnosis
Traumatologists must analyze gait disturbances, foot position, and general alignment, identifying varus or valgus foot, if there are deformities and if they are flexible or not, if they are corrected with the various positions. The clinical examination will show swelling or stiffness of the subtalar joint when moving the hindfoot from side to side, in eversion and supination.
Radiography is essential for a correct evaluation of the alignment and degree of osteoarthritis of the subtalar joint and neighboring joints.
Ankle and posterior subtalar arthrosis
Conservative treatment of subtalar osteoarthritis
The goal of treatment is to limit painful joint motion, accommodate the footprint, correct malalignment, and relieve and offload pressure points.
Conservative treatment of subtalar osteoarthritis is based on recommendations to slow the progression of the disease.
Some of them are:
- Do not walk, run or jump too much on uneven terrain.
- Perform physical therapy and non-impact exercises: swimming pool, cycling (helps mobility, proprioception and strength).
- Modify physical activity by avoiding activities that cause pain.
- In case of overweight, follow a diet to lose weight, along with the exercises described.
- Analgesic or non-steroidal anti-inflammatory drugs.
- Modification of footwear, use of orthotics or custom braces to stabilize the joint and also the midtarsal joint.
- In the initial stages, cartilage protectors, intra-articular hyaluronic acid infiltrations, platelet-rich plasma or autologous conditioned serum (Orthokine®) may help.
Surgical treatment of subtalar osteoarthritis
Surgical treatment is resorted to when the patient’s pain is disabling and prevents him/her from leading a normal life.
The operation consists of making a fusion or arthrodesis of the joint. It is indicated in cases of osteoarthritis or arthritis with pain, instability or deformity of the joint, which have not improved with conservative treatment.
The loss of mobility for the patient is minimal because the disease is already limiting the movement. Generally, the patient retains a residual mobility, but painful, so that the complete elimination of this residual mobility eliminates the pain and improves the function of the rest of the ankle and foot joints.