Upadhyay Sachin, Raza H K T, Srivastava Pranay
Department of Orthopaedics, Netaji Subhas Chandra Bose Medical College Jabalpur, (MP), India.
J Orthop Surg (Hong Kong). 2013 Apr;21(1):23-7. doi: 10.1177/230949901302100108.
To assess the Insall-Salvati ratio in normal Indian adults to determine its applicability and the incidence of patella alta and baja in Indian populations.
800 knees in 200 men and 200 women aged 18 to 50 (mean, 30) years were evaluated using lateral radiographs. The knee was set in semi-flexion (30º) to enable good visualisation of the patellar tendon and its insertion into the tibia on radiographs. The length of the patellar tendon (LT) over the length of the patella (LP)-the Insall-Salvati ratio-was measured, using a vernier caliper.
The mean LT/LP ratio was 1.14 (standard deviation, 0.18). Based on the 95% confidence interval, the ratio was considered normal if within ±40%. The LT/LP ratio was significantly higher in females than males (1.17 vs. 1.12, p<0.01). The cut-off point of patella alta was significantly greater in our Indian subjects than in western subjects (>1.5 vs. >1.2, p<0.0001). In the present cohort, the frequencies of patella alta (ratio, >1.5) and patella baja (ratio, <0.7) were 2.8% and 1%, respectively.
The use of the Insall-Salvati ratio to determine the patellar position is less applicable to Indian populations in which squatting, sitting cross-legged, and kneeling are customs. We propose that the normal range of the ratio for squatters among Indian populations be 0.7 to 1.5.
评估印度正常成年人的Insall-Salvati比率，以确定其适用性以及印度人群中高位髌骨和低位髌骨的发生率。
对200名年龄在18至50岁（平均30岁）的男性和200名女性的800个膝关节进行了侧位X线片评估。将膝关节置于半屈曲位（30°），以便在X线片上更好地观察髌腱及其在胫骨上的附着点。使用游标卡尺测量髌腱长度（LT）与髌骨长度（LP）的比值——Insall-Salvati比率。
LT/LP平均比率为1.14（标准差为0.18）。基于95%置信区间，如果该比率在±40%以内，则被认为是正常的。女性的LT/LP比率显著高于男性（1.17对1.12，p<0.01）。我们印度受试者中高位髌骨的临界点显著高于西方受试者（>1.5对>1.2，p<0.0001）。在本队列中，高位髌骨（比率>1.5）和低位髌骨（比率<0.7）的发生率分别为2.8%和1%。
使用Insall-Salvati比率来确定髌骨位置在有蹲坐、盘腿坐和跪等习俗的印度人群中适用性较低。我们建议印度人群中蹲坐者该比率的正常范围为0.7至1.5。
