Abstract：
BACKGROUND: Total knee arthroplasty (TKA) is the most effective method of pain relief and increased functional status for end-stage knee arthritis. We aimed to assess in patients undergoing unilateral, primary TKA whether the temperature of the operated limb, compared to the nonoperative limb, remains elevated up to 1 year postoperatively.
METHODS: Using a prospective, longitudinal, observational study design, 1,094 patients were enrolled, and 889 patients completed a minimum of 4 out of 5 follow-up appointments. There were 864 patients who had a normal postoperative course, while 25 patients were deemed to have a superficial or deep infection. Skin temperatures were measured using an infrared thermometer on the operated and nonoperated knees preoperatively, at 2, 6, 12 weeks, and 1 year postoperatively. A subgroup analysis was performed on the 25 patients deemed to have a superficial or deep infection.
RESULTS: There was a statistically significant increase in skin temperature in the operated versus nonoperated knee at every follow-up, with a P < .001. However, the effect size was small at the 1-year follow-up, with a mean difference in skin temperature of 0.3 °C. In the infected subgroup, there was a statistically significant difference in skin temperature at 2, 6, and 12 weeks, with a greater difference in skin temperature between the operated and nonoperated knees (4.05 versus 3.78 °C in the noninfected). However, there was little clinical difference (0.27 °C) at 2 weeks between infected and noninfected patients.
CONCLUSIONS: This study could improve postoperative interactions between patients and surgeons. It is normal for skin temperature post-TKA to increase initially and improve over time, but it can take up to 1 year before there is little clinical difference. Because of the small difference in the rise of skin temperature between infected and noninfected patients, there is little indication that skin temperature is a reliable indicator of infection.
METHODS: Using a prospective, longitudinal, observational study design, 1,094 patients were enrolled, and 889 patients completed a minimum of 4 out of 5 follow-up appointments. There were 864 patients who had a normal postoperative course, while 25 patients were deemed to have a superficial or deep infection. Skin temperatures were measured using an infrared thermometer on the operated and nonoperated knees preoperatively, at 2, 6, 12 weeks, and 1 year postoperatively. A subgroup analysis was performed on the 25 patients deemed to have a superficial or deep infection.
RESULTS: There was a statistically significant increase in skin temperature in the operated versus nonoperated knee at every follow-up, with a P < .001. However, the effect size was small at the 1-year follow-up, with a mean difference in skin temperature of 0.3 °C. In the infected subgroup, there was a statistically significant difference in skin temperature at 2, 6, and 12 weeks, with a greater difference in skin temperature between the operated and nonoperated knees (4.05 versus 3.78 °C in the noninfected). However, there was little clinical difference (0.27 °C) at 2 weeks between infected and noninfected patients.
CONCLUSIONS: This study could improve postoperative interactions between patients and surgeons. It is normal for skin temperature post-TKA to increase initially and improve over time, but it can take up to 1 year before there is little clinical difference. Because of the small difference in the rise of skin temperature between infected and noninfected patients, there is little indication that skin temperature is a reliable indicator of infection.
摘要：
背景：全膝关节置换术（TKA）是缓解终末期膝关节炎疼痛和增加功能状态的最有效方法。我们的目的是评估接受单侧治疗的患者，主要TKA是否手术肢体的温度，与非手术肢体相比，术后1年仍升高。
方法：使用前瞻性，纵向,观察性研究设计，1094名患者入选，889例患者完成了5次随访中至少4次.864例患者术后病程正常,而25例患者被认为有浅表或深部感染。术前使用红外线温度计对手术和非手术的膝盖测量皮肤温度，在第2、6和12周，术后1年。对25例被认为具有浅表或深部感染的患者进行了亚组分析。
结果：每次随访时，手术膝关节与非手术膝关节的皮肤温度均有统计学上的显着升高，P<0.001。然而,在1年的随访中，效应大小很小，皮肤温度的平均差异为0.3oC。在被感染的亚组中，在第2、6和12周的皮肤温度有统计学上的显着差异，手术和非手术膝盖之间的皮肤温度差异更大（未感染者为4.05oC，而非3.78oC）。然而,感染和未感染患者在2周时几乎没有临床差异（0.27oC）。
结论：这项研究可以改善患者和外科医生之间的术后互动。TKA后的皮肤温度最初增加并随着时间的推移而改善是正常的，但它可能需要长达1年的时间，才有微小的临床差异。由于感染和未感染患者之间皮肤温度上升的差异很小，几乎没有迹象表明皮肤温度是感染的可靠指标。
方法：使用前瞻性，纵向,观察性研究设计，1094名患者入选，889例患者完成了5次随访中至少4次.864例患者术后病程正常,而25例患者被认为有浅表或深部感染。术前使用红外线温度计对手术和非手术的膝盖测量皮肤温度，在第2、6和12周，术后1年。对25例被认为具有浅表或深部感染的患者进行了亚组分析。
结果：每次随访时，手术膝关节与非手术膝关节的皮肤温度均有统计学上的显着升高，P<0.001。然而,在1年的随访中，效应大小很小，皮肤温度的平均差异为0.3oC。在被感染的亚组中，在第2、6和12周的皮肤温度有统计学上的显着差异，手术和非手术膝盖之间的皮肤温度差异更大（未感染者为4.05oC，而非3.78oC）。然而,感染和未感染患者在2周时几乎没有临床差异（0.27oC）。
结论：这项研究可以改善患者和外科医生之间的术后互动。TKA后的皮肤温度最初增加并随着时间的推移而改善是正常的，但它可能需要长达1年的时间，才有微小的临床差异。由于感染和未感染患者之间皮肤温度上升的差异很小，几乎没有迹象表明皮肤温度是感染的可靠指标。
