Background:

The cause of osteochondritis dissecans (OCD) is unknown.

Purpose:

To determine if mechanical axis deviation correlates with OCD lesion location in the knee, if degree of mechanical axis deviation correlates with size of OCD lesion, and if the deformity was primarily in the distal femur or proximal tibia.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

We identified 61 knees that underwent osteochondral allograft (OCA) transplantation for femoral condyle OCD lesions and used preoperative lower extremity alignment radiographs to measure lower extremity mechanical axis, mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA), and hip-knee-ankle angle. Lesion location and area were retrieved from operative records.

Results:

The location of the OCD lesion was the medial femoral condyle (MFC) for 37 knees and lateral femoral condyle (LFC) for 24 knees. Among knees with MFC lesions, alignment was varus in 25 (68%). Conversely, knees with LFC lesions had valgus alignment in 16 (67%). The mLFDA was significantly more valgus in the LFC group. mMPTA was not different between MFC and LFC groups. There was no significant correlation between degree of mechanical axis deviation and lesion size.

Conclusion:

In this cohort, two-thirds of patients with symptomatic OCD lesions had associated mechanical axis deviation. Lesion location correlated with mechanical axis deviation (LFC lesions were associated with a deformity in the distal femur). Degree of deformity was not correlated with lesion size. Mechanical axis deviation may play a role in OCD pathogenesis. These data do not allow analysis of the role of mechanical axis deviation in causation or prognosis of OCD lesions, but surgeons treating OCD should be aware of this common association.

中文翻译：

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解剖性骨软骨炎的病变部位与机械轴偏斜高度一致。

背景：

剥离性骨软骨炎（OCD）的原因尚不清楚。

目的：

要确定机械轴偏差是否与膝盖中的OCD病变位置相关，是否确定机械轴偏差的程度与OCD病变的大小相关，以及畸形是否主要发生在股骨远端或胫骨近端。

学习规划：

横断面研究；证据水平3。

方法：

我们确定了61例行股骨con OCD损伤的骨软骨同种异体移植（OCA）移植的膝盖，并使用术前下肢对准X线照片测量了下肢机械轴，机械外侧股骨角（mLDFA），机械内侧胫骨近端角（mMPTA）和髋膝踝角。从手术记录中检索病变部位和面积。

结果：

OCD病变的位置为37膝的股内侧con（MFC）和24膝的股外侧lateral（LFC）。在患有MFC病变的膝盖中，有25例（68％）内翻。相反，患有LFC病变的膝盖有16个外翻对准（67％）。LFDA组中，mLFDA明显多于外翻。MFC组和LFC组之间的mMPTA相同。机械轴偏离程度与病变大小之间无显着相关性。

结论：

在这一队列中，三分之二有症状的强迫症患者具有相关的机械轴偏斜。病变位置与机械轴偏移相关（LFC病变与股骨远端畸形相关）。畸形程度与病变大小无关。机械轴偏差可能在OCD发病机理中起作用。这些数据无法分析机械轴偏斜在强迫症病变的因果关系或预后中的作用，但是治疗强迫症的外科医生应了解这种常见关联。