Does Use of a Variable Distal Femur Resection Angle Improve Radiographic Alignment in Primary Total Knee Arthroplasty?

详细信息    查看全文

• 作者：Denis Nam ; MD ; MSc ; Sravya Vajapey ; BA ; Jacob A. Haynes ; MD ; Robert L. Barrack ; MD ; Ryan M. Nunley ; MD
• 关键词：variable resection ; fixed resection ; intramedullary alignment ; femoral alignment ; mechanical axis
• 刊名：The Journal of Arthroplasty
• 出版年：2016
• 出版时间：September 2016
• 年：2016
• 卷：31
• 期：9_supp_S
• 页码：91-96
• 全文大小：776 K

文摘

The distal femur resection in total knee arthroplasty (TKA) is commonly made using a fixed angle relative to an intramedullary rod. This study’s purpose was to assess if a variable distal femur resection angle technique improves femoral component alignment in TKA.

d="absSec_2">Methods

d="abspara0015">This was a review of primary TKAs performed by 2 surgeons. One surgeon used a fixed resection angle of 5° for varus and 3° for valgus knees (“fixed” cohort). The second used hip-knee-ankle (HKA) radiographs to measure the angle between the femoral anatomic axis and a line perpendicular to the femoral mechanical axis, which was used as the resection angle for each patient (“variable” cohort).

d="abspara0020">Femoral component and HKA alignment were measured from standing HKA radiographs by 2, independent, blinded observers. Two hundred ninety patients were needed for power to detect a 15% difference in femoral component &ldquo;outliers&rdquo; (target of 0&deg; ± 2&deg;; significance = P < .05).

d="absSec_3">Results

d="abspara0025">Three hundred twenty consecutive patients were included with no differences in age, body mass index, or preoperative deformity (P = .3-.8). A 5&deg; resection angle was used in 46.3% of the variable and 80.0% of the fixed cohort patients.

d="abspara0030">A total of 80.2% of femoral components in the variable and 63.1% in the fixed cohort were within 0&deg; ± 2&deg; (P = .002; 84.6% of variable and 56.3% of fixed for valgus knees, P < .001). The mean HKA alignment was improved in the variable cohort (−1.4&deg; ± 3.3&deg; vs −2.6&deg; ± 3.3&deg;, P = .001).

d="absSec_4">Conclusion

d="abspara0035">Use of a variable distal femur resection angle improves femoral component alignment after TKA.