1. A COMPARATIVE STUDY ON THE EFFECTIVENESS OF THE TWO DIFFERENT DEVICES IN MANAGEMENT OF DDH IN NEWBORN AND INFANTS Roberto Azzoni, MD Orthopaedic Dep., State University of Milan 20097 S. Donato mil. (Milan) - 30, Morandi Street, Italy (roberto.azzoni@unimi.it) 118 developmental dysplasia of the hip (DDH) was detected by ultrasound (US) and classified following Graf’s criteria. A blinded randomized study on these cases was effected using Tueffuel- Mignon (59) and Coxa-Flex (59) devices, to evaluate effectiveness of both harnesses in DDH management. Study checked 51 type IIC; 43 IID; 15 IIIA; 9 IIIB. Type C recovered in 60,09 days, D in 100, IIIA in 103,60, IIIB in 108,66 days. Statistical model shows associations between outcome and pathological type (P<0.001), age at diagnosis (P<0.001) and device (P<0.02). Model shows that on average for each day of delay in diagnosis needed more than half a day for the patient to recover. Model confirmed that patients with serious pathologies need more time to recover. The treatment of DDH is based on the device, on the correct diagnosis with Graf’s method and on the early treatment, when the hip is more mouldable. Our opinion is that one device instead of another isn’t what’s important. What’s fundamental is the choice of the device based on long experience. Femal newborn 15 days old: right hip IIA, left hip IIIA Graf’s type; Ortolani and Barlow manoeuvres was positive at left, immediate treatment with Coxa-Flex device Same baby at 36 days old:. right and left hip Graf’s type IIA, again treatment with same device Same baby at 90 days old.: right and lrft hip Graf’s type IB, stop of the treatment X-Ray of the pelvis at the end of treatment: normal hip. Teuffel Mignon Device Coxa-Flex device Tab. 1. DDH treated with 2 different devices. Type of Grafn.TM device Treated n.CF device Treated n. IIC513120 IID432023 IIIA15510 IIIB936 Graf’s type of hipMedian days of recoveryMedian days of recovery with TM device Median days of recovery with CF devices Type C 60,095063,45 Type D 10058,5089,00 Type IIIA 103,6012294,50 Type IIIB 108,66121102,50 Table 3. Statistical analysis: linear multiple regression model for describethe relationship between time to remission (outcome) and available predictive variables (covariates: type of device, age, sex). Significance codes: 0 `***' 0.001 `**‘ 0.01 `*' 0.05 `.' 0.1 ` ' 1 Residual standard error: 15.65 on 111 degrees of freedom Multiple R-Squared: 0.59, Adjusted R-squared: 0.57 F-statistic: 27.45 on 6 and 111 DF, p-value: < 2.2e-16 ° Teuffel Mignon device. Estimate Std. ErrorT valuePr (>|t|) (Intercept)48.163.8712.44< 2e-16 *** Device (TM°)7.373.072.400.0180 * Age0.550.068.762.41 e-14*** type Graf (IID)8.353.272.550.0121* type Graf(IIIA)31.394.696.689.67e-10 *** type Graf(IIIB)37.095.806.384.11e-09*** Sex (M)1.442.990.480.6300 Table 4. Estimated time to remission at median age for male patient treated with TM. DDH Graf typeMedian ageEstimated remission time (days) IIC4280 IID3987 IIIA33107 IIIB49121 Tab. 2. Time of recovery of the DDH on the base of the Graf’s type and the device employed.