골밀도 번역(한국어 원본)Pedicle screw fixation에서 나사못과 골과의 결합 정도는 fusion level의 stability와 fusion을 위해 매우 중요하나 osteoporosis 환자에서는 pedicle screw loosening될 가능성이 높아 수술의 indication을 결정하는 데 어려움이 있다. 이에 저자들은 posterior lumbar pedicle screw instrumentation을 요하는 환자에 대해 bone mineral density 수치와 pedicle screw 삽입시 torque과의 상관관계를 알아내고 bone mineral density 수치에 대해 예측 가능한 pedicle screw의 삽입시 torque값을 밝히고자 한다.
2006년 11월부터 2009년 12월까지 동일 술자에게 pedicle screw를 이용한 posterior lumbar instrumentation을 시행받고 수술 전 dual-energy X-ray absorptiometry bone mineral density를 시행하고 수술 중 insertional torque of pedicle screw을 측정한 181명의 환자를 대상으로 하였다. 척추경 나사못 삽입시 디지털 torque gauge를 이용하여 토크값을 측정한 후, 삽입시 토크값과 해당 분절 bone mineral density값, lumbar 평균 골밀도값, hip 평균 골밀도값, 그리고, 척추경 inner diameter과의 상관관계를 스피어만 상관계수로 분석하였고, 골밀도값에 따른 척추경 나사못 삽입시 토크값은 simple regression analysis를 시행하여 분석하였다.
척추경 나사못 삽입시 토크값은 좌우 강한 상관관계 (r=0.7)를 보였고, 삽입 요추 골밀도 (r=0.49), 삽입 요추 T-값 (r=0.52), 요추부 평균 골밀도 (r=0.32), 요추부 평균 T-값 (r=0.50), 대퇴골 평균 골밀도 (r=0.45), 대퇴골 평균 T-값 (r=0.42)과는 뚜렷한 양의 상관관계가 있었다. Osteoporosis 환자의 경우 삽입시 토크값은 삽입 요추 골밀도 (r=0.45, 삽입 요추 T-값 (r=0.44), 요추부 평균 골밀도 (r=0.31)과는 뚜렷한 양의 상관관계가 있었고, 요추부 평균 T-값 (r=0.28)과는 약한 양의 상관관계가 있었다. Osteopenia 환자의 경우 삽입시 토크값은 삽입 요추 골밀도 (r=0.18)와 T-값 (r=0.24), 요추부 평균 T-값 (r=0.18), 대퇴골 평균 골밀도 (r=0.16) 및 대퇴골 평균 T-값 (r=0.14)과는 약한 양의 상관관계가 있었다.
정상 환자의 경우 삽입 요추 골밀도 (r=0.47), 삽입 요추 T-값 (r=0.45), 요추부 평균 골밀도 (r=0.53), 요추부 평균 T-값 (r=0.53), 대퇴골 평균 골밀도 (r=0.47), 대퇴골 평균 T-값 (r=0.45)과는 뚜렷한 양의 상관관계가 있었다.
골다공증 환자와 골감소증 환자의 삽입시 토크값은 정상 환자의 삽입시 토크값에 비해 통계적으로 유의하게 낮았다. 또한, 토크값에 대한 회귀 분석식은, -1.3 + 16.1 X 삽입 요추 골밀도, 9.6 + 7.87 X 요추 평균 골밀도, -3.26 + 24.6 X 대퇴부 평균 골밀도였다.
삽입시 토크값은 삽입 요추 골밀도, 요추 평균 골밀도, 고관절 평균 골밀도와 양의 상관관계를 나타냈으며, 특히 골다공증 환자와 정상 환자에서 골감소증 환자 보다 상관 관계가 더 뚜럿하엿고, 삽입분절 척추경 내경과는 상관관계가 없는 것으로 나타났다. 또한, 동일한 골밀도에서도 다양한 정도의 삽입시 토크값을 보여 골밀도로 정확한 척추경 나사못의 고정 정도를 예측하기는 어렵지만, 골밀도와 척추경 나사못의 고정력에는 양의 상관관계가 있으므로 골다공증이 의심되는 환자에게 척추경 나사못 삽입술이 필요한 경우 골밀도 검사를 하여 기기 고정 여부 및 분절수를 결정하는 것이 유용할 것으로 판단된다. |
골밀도 번역(영어 번역본)In a pedicle screw fixation, the degree of fusion between a screw and the bone is an essential factor for the stability of fusion level and fusion. In patients with osteoporosis, however, there is a high possibility for a pedicle screw loosening. Owing to this, there is a difficulty in determining the surgical indications. Given the above background, we attempted to identify the correlation between the bone mineral density and the torque during a pedicle screw fixation in patients who are indicated in posterior lumbar pedicle screw instrumentation. Then, we also attempted to clarify the predictable torque depending on the bone mineral density during a pedicle screw fixation.
The current study was conducted in 181 patients who underwent dual-energy X-ray absorptiometry (DEXA) during a period ranging from November of 2006 to December of 2009; received the posterior lumbar instrumentation using a pedicle screw by a single surgeon; and intraoperatively had an insertional torque of pedicle screw measured. In a pedicle screw fixation, the troque was measured using a digital torque gauge. An analysis was performed using Spearman correlation coefficient for the torque during a pedicle screw fixation, the bone mineral density at the surgical sites, the mean bone mineral density in the lumbar region, the mean bone mineral density in the hip and the inner diameter of a pedicle. Besides, a simple regression analysis was performed for the correlation between the bone mineral density and the torque generated during a pedicle screw fixation.
In regard to the torque generated durign a pedicle screw fixation, there was a strong positive correlation between the left and right side (r=0.7). It also had strong positive correlations with the bone mineral density at the surgical sites (r=0.49), T-value at the surgical sites (r=0.52), mean bone mineral density in the lumbar region (r=0.32), mean T-value in the lumbar region (r=0.50), mean bone mineral density in the femoral region (r=0.45) and mean T-value in the femoral region (r=0.42). In patients with osteoporosis, the torque generated durign a pedicle screw fixation had strong positive correlations with the bone mineral density at the surgical sites (r=0.45), T-value at the surgical sites (r=0.44) and mean bone mineral density in the lumbar region (r=0.31). But it had a weak positive correlation with mean T-value in the lumbar region (r=0.28). In patients with osteopenia, the torque generated durign a pedicle screw fixation had weak positive correlations with the bone mineral density at the surgical sites (r=0.18), T-value at the surgical sites (r=0.24), mean T-value in the lumbar region (r=0.18), mean bone mineral density in the femoral region (r=0.16) and mean T-value in the femoral region (r=0.14).
In normal patients, there were strong positive correlations between the bone mineral density at the surgical sites (r=0.47), T-value at the surgical sites (r=0.45), mean bone mineral density in the lumbar region (r=0.53), mean T-value in the lumbar region (r=0.53), mean bone mineral density in the femoral region (r=0.47) and mean T-value in the femoral region (r=0.45).
The torque generated during a pedicle screw fixation was significantly lower in patients with osteoporosis and those with osteopenia as compared with normal patients. Besides, a regression analysis formula for the torque was found to be -1.3 + 16.1 X (the bone mineral density at the surgical sites), 9.6 + 7.87 X (mean bone mineral density in the lumbar region) and -3.26 + 24.6 X (mean bone mineral density in the femoral region).
The torque generated during a pedicle screw fixation had positive correlations with the bone mineral density at the surgical sites, mean bone mineral density in the lumbar region and mean bone mineral density in the femoral region. Particularly in patients with osteoporosis and normal patients, this correlation was more notable as compared with patients with osteopenia. But there was no significant correlation with the internal diameter of a pedicle at the surgical sites. Besides, a variable degree of torque was observed during a pedicle screw fixation even at the same degree of bone mineral density. The bone mineral density cannot therefore be used in predicting the accurate degree of a pedicle screw fixation. Because there is a positive correlation between the bone mineral density and the fixation force of a pedicle screw, however, it can therefore be inferred that the assessment of bone mineral density would be useful in determining the fixation of device and the number of surgical segments in patients who are suspected to have osteoporosis and indicated in a pedicle screw fixation. |
