臼蓋形成不全の股関節に行った転子間骨切り術後症例に対するカスタムメイドセメントレスステムの術後10年以上の成績

Background: During fixation of total hip arthroplasty (THA) after osteotomy, it is difficult to obtain a good cement mantle with a cemented stem and to obtain good fit along the medullary canal with a ready-made stem. We developed a CT-based custom stem, which was inserted after osteotomy in THA. Methods: We investigated 32 hips in 28 patients. The mean patient age at surgery was 62 and the mean follow-up period was 13 years. The previous osteotomy was intertrochanteric varus femoral osteotomy in 14 hips, intertrochanteric valgus femoral osteotomy in 17, and Schanz osteotomy in one. CT studies were obtained with a 5 mm slice intervals and 2 mm slice width. We produced stems made of Ti-6Al-4V. The stems did not have collars and the proximal third was coated with a 400-μ. m-thick porous coating covered with 20-μ m-hydroxyapatite (HA) coating. Results: The Harris Hip Score improved from a preoperative mean of 49.9 points to a postoperative mean of 82.7 points. One patient complained of postoperative thigh pain. Fractures occurred in two hips. Dislocation occurred in three patients. To date. no patient has reqired revision of the stem due to aseptic loosening. There was bone-ingrown fixation in all hips. Severe stress shielding was found in 14 hips (44%) Conclusion: Stable fixation was achieved with the proximal press-fit of the custom stem. Although stress shielding was observed in 14 hips, excellent results were obtained over a follow-up period of 10 years with this custom stem system for hips after intertrochanteric femoral osteotomy.博士（医学）・乙第1419号・平成30年6月27

Indications for free vascularized fibular grafting for the treatment of osteonecrosis of the femoral head

Abstract Background The present study aimed to determine the indications for free vascularized fibular grafting for the treatment of osteonecrosis of the femoral head. Methods Seventy-one hips (60 patients) were clinically followed for a minimum of 3 years. Average follow-up period was 7 years. Etiologies were alcohol abuse in 31 hips, steroid use in 27, idiopathic in 7 and trauma in 6. Preoperative staging of the necrotic lesion was done using the Steinberg's classification system. The outcomes of free vascularized fibular grafting were determined clinically using the Harris hip-scoring system, radiographically by determining progression, and survivorship by lack of conversion to total hip replacement. Results The average preoperative Harris hip score was 56 points and the average score at the latest follow-up examination was 78 points. Forty-seven hips (67%) were clinically rated good to excellent, 4 hips (6%) were rated fair, and 20 hips (28%) were rated poor. Thirty-six hips (51%) did not show radiographic progression while 35 hips (49%) did, and with an overall survivorship of 83% at 7 years. Steroid-induced osteonecrosis was significantly associated with poor scores and survival rate (68%). Preoperative collapse was significantly associated with poor scores, radiographic progression and poor survival rate (72%). A large extent of osteonecrosis greater than 300 degrees was significantly associated with poor scores, radiographic progression and poor survival rate (67%). There was no relationship between the distance from the tip of the grafted fibula to the subchondral bone of the femoral head and postoperative radiographic progression. Conclusion In conclusion, small osteonecrosis (less than 300 degrees of the femoral head) without preoperative collapse (Steinberg's stages I and II) is the major indication for free vascularized fibular grafting. Steroid-induced osteonecrosis is a relative contraindication. Large osteonecrosis (greater than 300 degrees) with severe preoperative collapse (greater than 3 mm) is a major contraindication. Hips with 2 negative factors such as severe preoperative collapse and a large extent of osteonecrosis, require hip replacements.</p