醫(yī)學(xué)外文翻譯--股骨柄偏距和股骨頭直徑對于全髖關(guān)節(jié)置換術(shù)后 髖關(guān)節(jié)安全活動范圍的影響（英文）

1、Effects of the Femoral Offset and the Head Size on the Safe Range of Motion in Total Hip ArthroplastyAkinobu Matsushita, MD,* Yasuharu Nakashima, MD, PhD,* Seiya Jingushi, MD, PhD,* Takuaki Yamamoto, MD, PhD,* Akio Kurao

2、ka, PhD,? and Yukihide Iwamoto, MD, PhD*Abstract: The purpose of this study was to quantify the effects of femoral offset and head size on range of motion (ROM) after total hip arthroplasty. Modular prostheses were impla

3、nted into 11 cadaveric hips using a posterolateral approach and tested for ROM with 3 different offsets and 5 different femoral head sizes. Increasing the femoral offset to 4 and 8 mm resulted in 21.1° and 26.7°

4、; of improved flexion, and 13.7° and 21.2° of improved internal rotation, respectively. The ROM improved in a head size–dependent manner primarily because of increasing the jumping distance of the femoral head

5、rather than delaying any impingement. In contrast, the effectiveness of femoral offset was driven by delayed osseous impingement. Key words: total hip arthroplasty (THA), femoral offset, femoral head size, range of motio

6、n (ROM), jumping distance. © 2009 Elsevier Inc. All rights reserved.Dislocation is one of the most frequent and important complications after total hip arthroplasty (THA) [1-3]. The rate of dislocation after primary

7、 THA has been reported to be 2% to 5% [4-6]. Various factors influence dislocation. Patient-asso- ciated factors include age, sex, paralysis, and muscle weakness [4,7]. Factors associated with the surgery include inappro

8、priate cup or stem position, use of a posterior approach, repair of the soft tissue, and intraoperative positioning [3-5,8,9]. Characteristics of the prosthesis, such as head size and head-neck ratio, also influence hip

9、stability after THA [10-13]. In most dislocations, femoral heads deviate because of implant or osseous impingement. There-fore, it is important to delay impingement to prevent dislocations; and implants should be careful

10、ly designed to reduce the risk of impingement. Improvements can potentially be achieved by increasing the femoral head size and/or the femoral offset. Numerous studies have previously reported the effects of head size on

11、 range of motion (ROM) [2,4,13,14]. However, to our knowledge, only a few studies have focused on the relation between head size and impingement and jumping distance. Quan- tification of the effects of femoral offset on

12、ROM also has not yet been reported. In this study, we conducted experiments using cadavers to quantify the effects of femoral offset and femoral head size on safe ROM of the hip after THA. We also analyzed the effects of

13、 femoral head size on the jumping distance.MethodsImplantationModular total hip prostheses (PerFix HA; Japan Medical Material, Osaka, Japan) were implanted using a posterolateral approach in 11 hip joints from 8 cadavers

14、. In each surgery, the anterior jointFrom the *Department of Orthopedic Surgery, Graduate School of Medical, Sciences, Kyushu University, Higashi-ku, Fukuoka, Japan; and ?Department of Anatomy and Cell Biology, Graduate

15、School of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka, Japan. Submitted November 14, 2007; accepted February 10, 2008. No benefits or funds were received in support of the study. Reprint requests: Yasuharu N

16、akashima, MD, PhD, Depart- ment of Orthopedic Surgery, Graduate School of Medical, Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. © 2009 Elsevier Inc. All rights reserved. 0883-540

17、3/08/2404-0024$36.00/0 doi:10.1016/j.arth.2008.02.008646The Journal of Arthroplasty Vol. 24 No. 4 2009hoc Tukey test. Significance was defined as a P value less than .05.ResultsEffect of Femoral OffsetThe ROM of the hip

18、increased in a femoral offset– dependent manner. Increasing the femoral offset to 4 and 8 mm significantly increased the range of flexion by 21.1° and 26.7°, respectively (Fig. 3A). The range of flexion reached

19、 an average of 132.5° with an 8-mm femoral offset. Increasing the femoral offset to 4 and 8 mm with an adduction of 0°significantly increased the range of internal rotation by 13.7° and 21.2°, respect

20、ively (Fig. 3B). Significant improvement in the range of internal rotation was also observed with a 20° adduction.Head SizeThe range of flexion and internal rotation improved in a head size–dependent manner. Increas

21、ing the head size from 22 to 36 mm with a 0° adduction significantly increased the range of flexion and the range of internal rotation by 11.3° and 10.0°, respectively (Fig. 4A, B). Significant improvement

22、 in the range of internal rotation was also observed with 0° and 20° adductions.Fig. 3. Effects of the femoral offset in the ROM. Data are shown as the improvement (degrees) from that with 22-mm head size. A, R

23、ange of flexion until dislocation. Increasing the femoral offset to 4 and 8 mm laterally significantly increased the range of flexion by 21.1° and 26.7°, respectively. B, Range of internal rotation until disloc

24、ation with a 90° flexion and with or without a 20° adduction. Increasing the femoral offset to 4 and 8 mm laterally with 0° adduction significantly increased the range of internal rotation by 13.7° an

25、d 21.2°, respectively. Significant improvements of the internal rotation were also noted with 20° adduction. *P b .05.Fig. 4. Effects of head size on ROM. Data are shown as the improvement (degrees) from that w

26、ith 22-mm head size. A, Range of flexion until dislocation. The range of flexion increased in a head size–dependent manner. Increasing the head size from 22 to 36 mm with 0° adduction significantly increased the ran

27、ge of flexion by 11.3°. B, Range of the internal rotation until dislocation with a 90° flexion and with or without a 20° adduction. Increasing the head size from 22 to 36 mm with 0° adduction signific

28、antly increased the range of internal rotation by 10°. There was no significance in the ROM with 20° adduction. The head size larger than 28 mm significantly increased ROM compared with that less than 26 mm. Th