Department of Orthopedics, University of Washington Medical Center, Seattle, WA 98195, USA.
J Bone Joint Surg Am. 2011 Jan 5;93(1):11-9. doi: 10.2106/JBJS.I.01227.
Glenoid component loosening is a common cause of failure of total shoulder arthroplasty. It has been proposed that the heat generated during glenoid preparation may reach temperatures capable of producing osteonecrosis at the bone-implant interface. We hypothesized that temperatures sufficient to induce thermal necrosis can be produced with routine drilling and reaming during glenoid preparation for shoulder arthroplasty in vivo. Furthermore, we hypothesized that irrigation of the glenoid during reaming can reduce this temperature increase.
Real-time, high-definition, infrared thermal video imaging was used to determine the temperatures produced by drilling and reaming during glenoid preparation in ten consecutive patients undergoing total shoulder arthroplasty. The maximum temperature and the duration of temperatures greater than the established thresholds for thermal necrosis were documented. The first five arthroplasties were performed without irrigation and were compared with the second five arthroplasties, in which continuous bulb irrigation was used during drilling and reaming. A one-dimensional finite element model was developed to estimate the depth of penetration of critical temperatures into the bone of the glenoid on the basis of recorded surface temperatures.
Our first hypothesis was supported by the recording of maximum surface temperatures above the 56°C threshold during reaming in four of the five arthroplasties done without irrigation and during drilling in two of the five arthroplasties without irrigation. The estimated depth of penetration of the critical temperature (56°C) to produce instantaneous osteonecrosis was beyond 1 mm (range, 1.97 to 5.12 mm) in four of these patients during reaming and one of these patients during drilling, and two had estimated temperatures above 56°C at 3 mm. Our second hypothesis was supported by the observation that, in the group receiving irrigation, the temperature exceeded the critical threshold in only one specimen during reaming and in two during drilling. The estimated depth of penetration for the critical temperature (56°C) did not reach a depth of 1 mm in any of these patients (range, 0.07 to 0.19 mm).
Temperatures sufficient to induce thermal necrosis of glenoid bone can be generated by glenoid preparation in shoulder arthroplasty in vivo. Frequent irrigation may be effective in preventing temperatures from reaching the threshold for bone necrosis during glenoid preparation.
肩盂组件松动是全肩关节置换术失败的常见原因。有人提出，在肩盂准备过程中产生的热量可能达到在骨-植入物界面产生骨坏死的温度。我们假设，在活体全肩关节置换术中进行肩盂准备时，常规钻孔和扩孔会产生足以诱导热坏死的温度。此外，我们假设在扩孔过程中对肩盂进行冲洗可以降低这种温度升高。
使用实时、高清、红外热视频成像技术，确定了 10 例连续接受全肩关节置换术的患者在进行肩盂准备时钻孔和扩孔产生的温度。记录了最大温度和大于热坏死确定阈值的温度持续时间。前 5 例关节置换术未进行冲洗，并与后 5 例关节置换术进行比较，后 5 例关节置换术中在钻孔和扩孔过程中使用了连续球管冲洗。根据记录的表面温度，建立了一维有限元模型来估计临界温度穿透肩盂骨的深度。
我们的第一个假设得到了支持，在 5 例未冲洗的关节置换术中，有 4 例在扩孔过程中记录到超过 56°C 阈值的最大表面温度，在 5 例未冲洗的关节置换术中有 2 例在钻孔过程中记录到超过 56°C 阈值的最大表面温度。在这 4 例患者的 4 例中，在扩孔过程中，临界温度（56°C）的穿透深度足以立即产生骨坏死，在这 4 例患者中的 1 例和这 5 例患者中的 1 例在钻孔过程中记录到了超过 56°C 的温度，在这 2 例患者中，在扩孔过程中记录到了超过 56°C 的温度。在这些患者中，没有任何一位患者的临界温度（56°C）穿透深度达到 1 毫米（范围，1.97 至 5.12 毫米）。我们的第二个假设得到了支持，观察到在接受冲洗的组中，只有 1 例在扩孔过程中和 2 例在钻孔过程中温度超过临界阈值。在这些患者中，临界温度（56°C）的穿透深度均未达到 1 毫米（范围，0.07 至 0.19 毫米）。
在活体全肩关节置换术中，肩盂准备过程中产生的温度足以诱导肩盂骨发生热坏死。频繁冲洗可能有助于防止在肩盂准备过程中温度达到骨坏死的阈值。
