Subchondral insufficiency fracture (SIF) of the femoral head is one of the predominant etiologies of rapidly progressive osteoarthritis of the hip (RPOH). SIF is a rare disease that causes acute pain in the hip joint. It is most frequently found in elderly women with osteoporosis. It is often underdiagnosed or misdiagnosed as osteonecrosis of the femoral head. SIF is currently a well-established cause of RPOH; however, the deeper etiology of SIF is not clear. Good clinical outcomes have been reported for hip preservation therapy and hip replacement. SIF is not obvious radiologically in the early stage, and a T1-weighted magnetic resonance imaging shows a discontinuous low-intensity band under the articular cartilage convex to the articular surface as its characteristic manifestation. Some patients will lose the opportunity to preserve the hip joint due to symptoms such as progressive joint space narrowing and subchondral collapse within a very short period. Patients with progressive hip space narrowing and subchondral collapse on Xray should be converted to total hip arthroplasty. Based on the characteristics of the disease, surgeons need to master the clinical and radiological characteristics of SIF and strive for early diagnosis and treatment.

Total hip arthroplasty (THA) has been one of the most successful orthopaedic surgery in the last 50 years, with an excellent survival rate of more than 20 years. However, hip instability, impingement, dislocation, and liner wear remain common causes of THA failure and revision after THA. To minimize the risk of postoperative complications, abnormal spine-pelvic-hip mobility and its impact on THA outcomes have received increasing attention. According to the concept, the patient's pelvic mobility should be fully considered when making preoperative plans for THA. Individualized anteversion and inclination angles should be set according to the patient's sagittal balance and pelvic mobility to reduce the incidence of postoperative adverse events and prolong the life of the prosthesis. In the literature, recent studies have shown that patient aging, postural changes in daily life, high body mass index (BMI), and different surgical approaches and positions can impact spinopelvic mobility. Because changes in pelvic mobility translate into changes in acetabular orientation, excessive intraoperative or postoperative changes in pelvic mobility may result in poor intraoperative prosthesis orientation, postoperative impingement, dislocation, and accelerated liner wear, ultimately shortening the life of the prosthesis. Therefore, it is vital to evaluate and measure spinopelvic mobility preoperatively, investigate the factors that influence intraoperative pelvic mobility changes and the use of assisted positioning devices for accurate cup placement, and observe postoperative changes in pelvic mobility and the resulting adverse outcomes. This review takes the current literature on the spine-pelvic-hip interrelationship as a starting point and presents studies on the factors influencing spinopelvic mobility and the strategies for perioperative management of THA.