title: Anterior Hip Subluxation due to Lumbar Degenerative Kyphosis and Posterior Pelvic Tilt.
abstract: Nontraumatic anterior subluxation and dislocation of the hip joint are extremely rare. A 58-year-old woman presented to our outpatient clinic with left hip pain with a duration of 15 years. There was no history of trauma or other diseases. Her hip pain usually occurred only on walking and not at rest. Physical examinations demonstrated no tenderness in the hip joint. The range of motion of both hip joints was almost normal. Laxity of other joints was not observed. The bone mineral density of the lumbar spine and proximal femur confirmed a diagnosis of osteoporosis. A plain radiograph showed osteoarthritic changes of the hip joints, severe posterior pelvic tilt, and superior displacement of both femoral heads, especially in a standing position. Three-dimensional computed tomography (3DCT) revealed anterior subluxation of both femoral heads. Seven years after the initial visit, both hip joints showed progression to severe osteoarthritis. Although the exact cause remains unclear, lumbar kyphosis, posterior pelvic tilt, and a decrease in acetabular coverage may have influenced the current case. We should be aware of these factors when we examine patients with hip osteoarthritis.
authors.affiliation: Ugo Municipal Hospital, 44-5 Otomichi, Nishimonai, Ugo 012-1131, Japan.
authors.forename: Hiroyuki
authors.identifier: 0000-0001-5011-7184
authors.initials: H
authors.lastname: Tsuchie
authors.affiliation: Department of Orthopedic Surgery, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita 010-8543, Japan.
authors.forename: Shin
authors.initials: S
authors.lastname: Yamada
authors.affiliation: Japanese Red Cross Akita Hospital, 221-1 Inashirozawa, Saruta, Kamikitate, Akita 010-1495, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tazawa
authors.affiliation: Department of Orthopedic Surgery, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita 010-8543, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kijima
authors.affiliation: Department of Orthopedic Surgery, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita 010-8543, Japan.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Shimada