Buttock groove bone swelling and pain may be caused by sacroiliitis, sciatic tuberosity bursitis, sacrococcygeal fracture, and femoral head necrosis. 1. Sacroiliac arthritis: Sacroiliac arthritis may be caused by infection, long-term poor posture, acetabular dysplasia and so on. Patients will have pain in the hip or lower back, morning stiffness, limited joint movement, etc. Therefore, patients will show buttock groove bone swelling and pain. 2. Sciatica bursitis: Sciatica bursitis is considered to be caused by prolonged sedentary activities and friction of the buttocks. Patients will have sciatica pain, and when the pain is severe, they cannot sit down, so patients with sciatica bursitis will have pain in the buttock groove. 3. Sacrococcygeal fracture: Sacrococcygeal fracture may be caused by direct or indirect violence such as fall or fall from height. The patient mainly manifests sacrococcygeal pain, swelling, anal swelling, etc., and thus the patient will have the symptom of buttock groove bone distension and pain. 4. Other: patients with buttock groove bone pain may also be femoral head necrosis, trauma, sacrococcygeal fasciitis, hip muscle strain, sacral osteophytes and other factors. It is recommended that patients with buttock groove bone pain need to consult a doctor in time, the doctor will choose the appropriate measures according to the cause of the treatment.