[雙語翻譯]醫(yī)學外文翻譯--犬全膝關節(jié)置換模型使用pa涂層脛骨假體的影像學評估（英文）

1、Tibial Component Fixation with a Peri-Apatite CoatingEvaluation by Radiostereometric Analysis in a Canine Total Knee Arthroplasty ModelMatthew J. Allen, Vet MB, PhD,*y Kendall A. Leone, BS,y Michael J. Dunbar, MD, PhD,z

2、Amos Race, PhD,y Paula F. Rosenbaum, PhD,§ and Jonathan M. Sacks, MS, MBA∥Abstract: Cementless fixation for the tibial component in total knee arthroplasty (TKA) remains problematic. Peri-Apatite (PA), a solution-de

3、posited hydroxyapatite, is under investigation as an option for improving the fixation of cementless tibial components. In this study, radiostereometric analysis was used to document implant migration in 48 dogs that und

4、erwent TKA with cementless, PA-coated, or cemented tibial components. Migration at 12 weeks was similar in the 2 groups. At 12 months, there was greater migration in the PA-coated group, but the difference between the 2

5、groups was below the threshold considered clinically significant. In this canine TKA model, cementless fixation with PA performed less well than did cemented fixation, but not to a degree that would make a clinical diffe

6、rence in the short term. Keywords: implant migration, dog, arthroplasty, bone cement, hydroxyapatite. © 2012 Elsevier Inc. All rights reserved.Cementless fixation offers significant potential advan- tages over cemen

7、ted fixation for total joint arthroplasty. In addition to the elimination of bone cement as a source of particulate debris [1-3], cementless fixation is more amenable to minimally invasive surgical approaches and better

8、preserves periprosthetic bone stock at the time of surgery [4,5]. With the current trend toward performing total joint arthroplasty in younger patients [6] and patients with higher body mass indices [7], preservation of

9、bone mass may be critically important in optimizing the mechanical integrity of the bone-implant interface and ensuring implant longevity.Although cementless implants have a successful track record in total hip arthropla

10、sty [8-10], experience to date with traditional bone ingrowth surfaces (beads, fiber mesh, etc) have produced mixed results with total knee arthroplasty (TKA) implants [11-13]. Data from the Swedish Knee Arthroplasty Reg

11、istry indicate that the risk of aseptic loosening is significantly higher with cementless TKA implants than with cemented implants [14]. The use of a bioactive coating such as hydroxyap- atite (HA) has been shown to enha

12、nce bone apposition and improve implant fixation in animal models [15-17], and there is widespread interest in developing these coatings for TKA implants. However, concerns remain that variations in coating composition a

13、nd deposition methods make it very hard to obtain predictable osseointegration in TKA. As new coating methodologies and ingrowth surfaces are developed, there is a pressing need for preclinical data to support the safety

14、 and efficacy of these candidate coatings and fixation surfaces in animal models that faithfully recapitulate the clinical features of TKA in humans. The specific aim of this study was to determine whether a new, solutio

15、n-deposited form of HA (Peri- Apatite, or PA; Stryker Orthopaedics, Mahwah, NJ) [18] provides effective fixation of the tibial component in cementless TKA. Because most preclinical research onFrom the *Department of Vete

16、rinary Clinical Sciences, The Ohio State University, Columbus, Ohio; yDepartment of Orthopedic Surgery, SUNY Upstate Medical University, Syracuse, New York; zDepartment of Orthopedic Surgery, Dalhousie University, Nova S

17、cotia, Canada; §Department of Public Health and Preventive Medicine, SUNY Upstate Medical University, Syracuse, New York; and ∥Stryker Orthopaedics, Mahwah, New Jersey. Submitted April 26, 2011; accepted December 24

18、, 2011. The Conflict of Interest statement associated with this article can be found at doi:10.1016/j.arth.2011.12.029. Reprint requests: Matthew J. Allen, Vet MB, PhD, Department of Veterinary Clinical Sciences, The Ohi

19、o State University, 601 Vernon L. Tharp St, Columbus, OH 43210. © 2012 Elsevier Inc. All rights reserved. 0883-5403/2706-0052$36.00/0 doi:10.1016/j.arth.2011.12.0291138The Journal of Arthroplasty Vol. 27 No. 6 2012r

20、adiographswereobtainedtodocumentaccurateposition- ing of the implant, a second dose of antibiotics was administered, and a Robert Jones bandage was applied. The dog was then transferred to a stainless steel recovery cage

21、(Shor-Line,KansasCity,Kan)forovernighthousing. Postoperative pain management included opiate analgesics (morphine 10 mg IM) every 6 to 12 hours for 2 days postoperatively. Nonsteroidal anti-inflammatory agents (carprofen

22、 100 mg orally, once daily) and antibiotics (cephalexin 500 mg orally, twice daily) were given on the first postoperative morning and continued for 7 to 10 days postsurgery. The bandage was typically removed 3 to 4 days

23、postsurgery. Skin staples were removed 8 to 10 days postsurgery. The animal care staff checked the animals at least twice daily, and any animal showing signs of pain or distress was referred to the attending veterinarian

24、. Animals were also examined 5 days/wk by one of the technicians on the study. Body temperature was recorded, and the skin incision was checked for signs of inflammation and/or infection. Once the skin staples had been r

25、emoved, the focus changed to evaluating knee function and limb use. Dogs were allowed out of their kennels for periods of up to 15 minutes from weeks 2 through 6, with the expectation being that limb use would gradually

26、increase over this period. From week 6 onward, dogs were allowed 30 minutes of unrestricted activity per day. Passive joint range of motion wasmeasured with a goniometer, and lameness was evaluated using an established s

27、coring scheme [27] at 6, 12, 26, and 52 weeks after surgery. Biplanar (orthogonal view) radiographs for RSA were obtained with the animal under heavy sedation with medetomidine hydrochloride (750 μg/m2 IV). The operated

28、stifle joint was positioned in the knee cage (Cage 10; RSA Biomedical) with the long axis of the hind limb parallel to the axes of the laboratory coordinate system. The initial (baseline) examination was typically perfor

29、med 1 week after surgery, and follow-up examinations were performed at 6, 12, 26, and 52 weeks postsurgery. Migration of the tibial tray was determined by measuring relative motion between the implant and the proximal ti

30、bia (the reference segment). The mean error of rigid body fitting was used as an estimate of the stability of the markers within the reference and moving segments. In this study, a mean error of less than 0.2 mm was cons

31、idered acceptable [28]. The distribution of the markers within the 2 segments was quantified as the condition number, with a condition number of less than 150 being considered acceptable for this study, as is current pra

32、ctice with clinical RSA in humans [29]. Migration of the tibial tray in relation to the proximal tibia was described as rotation around or translation along the 3 cardinal axes, x, y, and z. Global analysis of maximal im

33、plant migration was performed using theFig. 1. (A) Cemented (left) and cementless (right) tibial components used in this study. Close-up images of the morphology of the cemented (B) and cementless (C) fixation surfaces.1