Department of Orthopaedic Surgery, Chung-Ang University College of Medicine, Seoul, Korea.
Clin Orthop Surg. 2010 Jun;2(2):85-9. doi: 10.4055/cios.2010.2.2.85. Epub 2010 May 4.
The hemiepiphyseal stapling has both positive and negative effects on effective leg length. The purpose of this study was to analyze change in effective leg length after angular correction by hemiepiphyseal stapling, and to validate in clinical cases.
Mathematical analysis of a hemiepiphyseal stapling model was conducted. The induced formula was validated in 6 cases fulfilling the assumptions of the model. Anatomical parameters involved in this formula were measured in additional 21 cases undergoing hemiepiphyseal stapling or hemiepiphysiodesis.
EFFECTIVE LEG LENGTH INCREASED OR DECREASED ACCORDING TO THREE PARAMETERS IN THIS MODEL: 1) limb length distal to the operated physis (L), 2) width of the operated physis (d), and 3) the amount of angular deformity to be corrected (theta). Actual change in effective leg length of 6 cases similar to this model coincided with the predicted change at least in its direction. L/d ratio was 4.82 +/- 0.51.
Considering the narrow range of the L/d ratio, hemiepiphyseal stapling is likely to decrease effective leg length if the amount of angular correction is less than 10 degrees , whereas to increase it if the amount of angular correction is larger than 16 degrees . This should be taken into consideration when selecting the surgical method for angular deformity correction in skeletally immature patients.
半骺板截骨术对有效下肢长度既有积极影响，也有消极影响。本研究旨在分析半骺板截骨术矫正角度后有效下肢长度的变化，并通过临床病例验证。
对半骺板截骨模型进行数学分析。对满足模型假设的 6 例进行了诱导公式验证。在接受半骺板截骨或半骺骺阻滞术的另外 21 例中，测量了该公式中涉及的解剖参数。
该模型中的三个参数决定了有效下肢长度的增加或减少：1）操作骺板远端的肢体长度（L），2）操作骺板的宽度（d），3）要矫正的角度畸形量（theta）。与该模型相似的 6 例实际有效下肢长度的变化至少在方向上与预测的变化一致。L/d 比值为 4.82±0.51。
考虑到 L/d 比值的狭窄范围，如果角度矫正量小于 10 度，半骺板截骨术可能会减少有效下肢长度，而如果角度矫正量大于 16 度，则会增加有效下肢长度。在选择未成熟骨骼患者角度畸形矫正的手术方法时，应考虑到这一点。
