Firoozbakhsh K, Moneim M S, Mikola E, Haltom S
Department of Orthopaedics and Rehabilitation, Health Sciences Center, University of New Mexico, Albuquerque NM 87131-5296, USA.
Iowa Orthop J. 2003;23:46-50.
Ulnar shortening osteotomy is a surgical treatment option for patients with symptomatic ulnar positive variance for a variety of reasons. Delayed healing and nonunion of the osteotomized sites have been reported and present problematic complications of this procedure. Studies have shown nonunion rate with transverse cuts ranging from 8-15%. The goal is to achieve parallel cuts, thus maximizing the contacting bony surface area for a better union rate. The senior surgeon attempted using a custom thick blade to insure parallel cuts. The concern is whether the heat generated during such a cut would contribute to non-union. It is our hypothesis that complications with ulnar shortening osteotomy using a thick blade are secondary to excess heat generation. When generated heat surpasses the threshold temperature of bone tissue, the organic matrix is irreversibly damaged and necrosis of the bony ends may occur. The present study measured the heat generation during ulnar osteotomy using different blade thicknesses. Thirty-five fresh turkey femurs, having similar size and cortical thickness of the human ulna, were used. Loading was done at three different speeds of 0.66, 1.0, and 1.5 mm/second corresponding respectively to 30, 20, and 10 seconds for the complete cut. A general linear statistical model was fitted relating temperature rise to three predictive factors: blade thickness, sensor distance, and initial bone temperature. There was a statistically significant relationship between temperature rise and all three predictor variables at the 99% confidence level. There was no statistically significant relationship between temperature rise and the number of cuts with the same blade up to 10 times. Compared with the single microsagital saw blade, the temperature rise for the double thickness blade was 14% higher and for the triple thickness blade was 23% higher. The temperature rise was inversely related to the speed of the cut. The temperature rise for the bone cut in 30 seconds was 1.5 times higher than the temperature rise when the bone was cut in 10 seconds. Complications with ulnar shortening osteotomy may be secondary to excess heat generation. A new thick saw blade design and the use of proper internal/external irrigation may overcome the problem.
尺骨短缩截骨术因多种原因是有症状的尺骨正向变异患者的一种手术治疗选择。已有报道称截骨部位愈合延迟和不愈合，这是该手术存在的棘手并发症。研究表明，横向截骨的不愈合率在8%至15%之间。目标是实现平行截骨，从而使骨接触表面积最大化以提高愈合率。资深外科医生尝试使用定制的厚刀片以确保平行截骨。问题在于这种截骨过程中产生的热量是否会导致不愈合。我们的假设是，使用厚刀片进行尺骨短缩截骨术的并发症是由于产生过多热量所致。当产生的热量超过骨组织的阈值温度时，有机基质会受到不可逆的损害，可能会发生骨端坏死。本研究测量了使用不同厚度刀片进行尺骨截骨术时产生的热量。使用了35根新鲜火鸡股骨，其大小和皮质厚度与人类尺骨相似。分别以0.66、1.0和1.5毫米/秒这三种不同速度加载，完成截骨分别对应30、20和10秒。建立了一个一般线性统计模型，将温度升高与三个预测因素相关联：刀片厚度、传感器距离和初始骨温。在99%置信水平下，温度升高与所有三个预测变量之间存在统计学显著关系。在使用同一刀片截骨达10次的情况下，温度升高与截骨次数之间无统计学显著关系。与单微矢状锯片相比，双倍厚度刀片的温度升高高14%，三倍厚度刀片的温度升高高23%。温度升高与截骨速度呈负相关。30秒截骨时骨的温度升高比10秒截骨时高1.5倍。尺骨短缩截骨术的并发症可能是由于产生过多热量所致。一种新的厚锯片设计以及适当的内/外冲洗使用可能会克服这个问题。
