回復期リハビリテーション病棟入院中に股関節の病変により膝痛を呈した2症例

Referred Pain to the Knee with Hip Diseases : A Case Series Study

はじめに

　股関節病変に伴って膝痛を呈しうることは以前より知られている^1）．しかしながら，リハビリテーション（以下，リハ）施行患者において膝痛を呈した場合，その原因を股関節病変に見出すことは必ずしも容易ではない．今回，回復期リハ病棟入院中に膝痛を呈しその原因となった股関節病変を発見するのに難渋した2症例を経験したため，若干の文献的考察とその経過を報告する．

Abstract : Patient 1, a 75-year-old woman with a past history of osteoarthritis of the right knee and Parkinson disease, had a subarachnoid hemorrhage. She complained of right knee pain during her rehabilitation. It turned out that she had sustained a right trochanteric fracture after falling out of bed in another hospital. Patient 2, an 86-year-old woman with a past history of rheumatoid arthritis, was treated with the Gamma nail technique for a left trochanteric fracture. She described experiencing pain in the region from the left knee to the lateral side of the left thigh during her rehabilitation, about two months after the hip operation. X-ray and computed tomography images showed varus displacement of the femoral head due to screw cut-out. In each of these cases, it took some time for us to detect the underlying hip diseases. The dermatome shows regions of the skin innervated by each single spinal segment. Similarly, the sclerotome shows regions of bone and periosteum innervated by each single spinal segment. According to Inman and Saunders's sclerotome, the proximal portion of the femur is mainly innervated by L3, L4 and L5. On the other hand, in dermatome perspective, L3, L4 and L5 innervate the knee and region around the knee. It means that hip diseases can cause referred pain to the knee. Untypical pain in distant regions from the hip joint makes it difficult to examine the hip joint and causes delay in an accurate diagnosis, as in the cases just described. Therefore, we should keep in mind that hip diseases can cause referred pain to the knee.