非骨水泥近端固定股骨柄和远端固定股骨柄中期随访时骨丢失的X线片表现

COMPARISON OF MEDIUM-TERM X-RAY IMAGINGS BETWEEN ANATOMIQUE BENOIST GIRAUD HIP AND ANATOMIC MEDULLARY LOKCING HIP

目的比较非骨水泥近端固定(anatomique benoist giraud,ABG)股骨干骺端与远端固定(anatomic medullary locking,AML)股骨干假体周围骨丢失特点,评价中期X线片表现。方法对1992年1月～1996年12月接受髋关节置换的患者,其中ABG176髋分别为:股骨头坏死103髋,先天性髋臼发育不良57髋,其他原因16髋,共计125例;AML220髋分别为:股骨头坏死147髋,先天性髋臼发育不良65髋,其他原因8髋,共计173例。术后随访5～12年,平均8年的髋关节X线片正位,对比术后即刻和随访时X线片显示的骨质变化,按照Gruen分区记录发生骨丢失;测量骨丢失的范围占假体周围骨长度的比例。比较两种假体周围骨丢失的特点。结果术中造成股骨干裂纹骨折ABG2髋,AML5髋;干骺端裂纹骨折ABG3髋,AML1髋。术后外伤骨折ABG6髋,AML3髋,2髋ABG行翻修术,余行复位内固定术。ABG随访期间9髋翻修,其中无菌松动7髋,骨折2髋;AML随访期间无菌性松动3髋,未翻修;ABG和AML发生骨丢失的部位相似,近端1和7区最先和最多出现骨丢失,随时间加重并由近端向远端发展。AML在2、5、6、7区发生骨丢失者多于ABG;AML假体周围骨丢失的范围大于ABG。结论骨丢失的主要原因为应力遮挡,AML远端固定,在假体近侧发生应力遮挡性骨丢失;解剖形近端固定的ABG股骨柄减少了应力遮挡作用和骨丢失。值得注意的是AML在10年后骨丢失发展缓慢,提示假体周围骨丢失不会无限制发展,保证了假体的长期稳定性。在术后12年内ABG假体周围骨丢失少于AML。

Objective To compare the bone resorption between the proximal fixation of the anatomique benoist giraud （ABG） hip and the distal fixation of the anatomic medullary locking（AML） hip by the medium-term X ray films, and to evaluate the clinical results of the two prostheses. Methods From January 1992 to December 1996, 298 patients （396 hips） underwent the total hip arthroplasty at Wilson Hospital in Korea. In 125 patients, 176 hips were ABG hips, including 103 avascular necrosis hips, 57 dysplasia hips, and 16 other diseased hips; In the other 173 patient the remaining 220 hips were AML hips, including 147 avascular necrosis hips, 65 dysplasia hips, and 8 other diseased hips. The A-P X-ray imagings were followed up for 5-12 years averaged 8 years, and were compared with the immediate postoperative X-ray imagings. The bone resorption area was measured and the bone resorption cases were recorded according to the Gruen zone obsesvation. Results During operation, 2 ABG hips and 5 AML hips were cracked at the femoral diaphysis; 3 ABG hips and 1 AML hip were cracked at the metaphysis; 6 ABG hips and 3 AML hips were fractured because of trauma after operation; among them, 2 ABG hips needed the stem revision and the remaining hips underwent the open reduction and the internal fixation. During the follow-up, 9 ABG hips were revised, 7 hips of which developed the aseptic loosening. No AML hip was revised, but 3 AML hips developed the aseptic loosening. The bone resorption pattern in the ABG and AML hips was similar. The bone resorption occurred most commonly in the Gruen zones 1 and 7, and it extended from the metaphysis to the diaphysis. In the Guren zones 2, 5, 6 and 7, there were more AML hips than ABG hips that developed the bone resorption. The bone resorption area around the AML hip was larger than that around the ABG hip. Conclusion The stress shielding bone resorption usually occurs proximally to the union area of the bone and the prosthesis. The ABG prosthesis is a proximal fixation prosthesis, therefore, the stress shielding bone resorption can be reduced. The bone resorption around the AML prosthesis develops slowly within 10 years after operation. The stress shielding bone resoption may reach the summit within 10 years and it will not develop endlessly, so the prosthesis will be stable for a long time. The probability of the bone resorption in the ABG prosthesis is smaller than that in the AML prosthesis. The bone resorption around the AML prosthesis may develop slowly after 10 years and will not affect the stability of the orosthesis for a long, time.