The Evaluation Of POSSUM Software Scoring System In Predicting The Postoperative Risk In Patients Of The Fractures In Hip

Hip fracture is common orthopaedic trauma and mostly occur in the old patients and the risk increases with age. The old patients often had maladies of the heart, liver and kidney before the trauma, therefore the mortality and the morbidity are higher than other fractures. Following improvement of the living standard and elongation of the mean longevity, the risk of the kind of fracture has also the increasing trend, Aimed at the diseases like hip fracture which has higher risk than others, we need a scoring system which can exactly estimate operative mortality and morbidity to assess the results of the operation. It is important to predict patients' risk level of operation accurately. The assessment of operative risk mainly depends on the patients symptoms, signs, physiological parameters, operative severity and so on. The Physiological and Operative Severity Score for the enumeration of Mortality and morbidity (POSSUM) was designed by Copeland GP. However, P-POSSUM was developed by Whitley, the scholars of British Portsmouth center, following the reports that POSSUM tended to overestimate the postoperative mortality, particularly in the low risk groups. 436 Patients in the Orthopaedics Department of the First Hospital of Jilin University were retrospectively analyzed with the mordified POSSUM and P-POSSUM surgical scoring system respectively in this study from January 1995 to March 2005. The comparison between the observed and the predicted morbidity and the comparison between the observed and the predicted mortality were made With in 30 days after operation. Modulating the score is tried to forecasting the mortality and morbidity . POSSUM scoring system is modified by Orthopaedics specialty. Replaced the peritoneum infection in the severity index of operation with wound infection. Replaced the several operations at one time with the times of operations. The size and type of operation were made into 4 grades and given corresponding scores. The comparison between the observed and the predicted morbidity and between the observed and the predicted mortaliity were made Within 30 days after operation respectively. The ROC curve was draw and described the coincident degree. And the Interceptive point was made. Compare the scores of the complication group and the non-complication group, the dead group and living group. Analyze the reason of higher incidence of a disease and mortality rate. Improve the formulae through modulating the score of every grade. Every patients was scored carefully according to P-POSSUM and POSSUM scoring system. Missing data may be treated as normal values without influencing outcomes. The predicted mortality were calculated via PS, OS and the logistic equations respectively. POSSUM Morbidity predicting equation: In R2/ (1-R2) =-5.91+0.16×PS+0.19×OS POSSUM mortality predicting equation: In R2/ (1-R2) =-7.04+0.13×PS+0.16×OS P-POSSUM mortality predicting equation: Ln Rl/ (1-R1) =-9.065+0.1692xPS+0.1550xOS(Rl: predicted mortality by P-POSSUM; R2: predicted mortality by POSSUM; PS: physiological score; OS: operative severity score) Results: In the complicative group, both the physiological scores and the operative severity scores of POSSUM scoring system were significantly higher than that of non-complicative group (18.96 + 4.83 vs 15.65 + 3.66 in pysiological score and 13.47 + 2.01 vs 11.74 + 2.26in operative severity score) . The mean ages of the patients were 67.67+12.89 and 61.27 + 14.72 respectively. In the group of the death, both the physiological scores and the operative severity scores of scoring system were significantly higher than the living group (25.56±3.78 vs 16.46 + 4.09 in physiological score and 14.22 + 0.67 vs 12.25 + 2.33 in operative severity score) . The mean ages of the patients were 85.33 + 3.21 vs 62.74 + 14.22. There was perfect consistent between the observed and the predicted morbidity as calculated by published predictor equation for morbidity, and consistent for mortality in the high risk band. With 0.28 as the Cut point of morbidity, and the Sensitivity is 73%, and the specificity is 69%, and the coincident degree is 70 %, and the area of ROC is 0.72 with POSSUM. With 0.254 as the Cut point of mortality, and the Sensitivity is 92%, and the specificity is 86%, and the coincident degree is 89 %, and the area of ROC is 0.938 with P-POSSUM. Adjusted the score Conclusions: Modified POSSUM scoring system may be used to predict the morbidity in patients of hip fracture. Forthermore POSSUM scoring system overpredict the overall risk of death , but P-POSSUM may be used to predict the mortality. We can use scoring system to depress risk before operation. Modulating the score is tried to forecasting the mortality and morbidity, we want to choose a better way. .POSSUM and P-POSSUM has been used widely in general surgery , vascular surgery, thoracic surgery, urinary surgery and so on. Since orthopedics is an important part of surgery, the above systems should be introduced to this field as quickly as possible. It is very partial and subjective to evaluate the old patients operative risk level after trauma because of the personal difference . It is very important to use scoring system before operation. It affect the health of patient. We can adjust the score to be the satisfy the need of Orthopaedics. The score system can be used to evaluating the severity of patient. When the score is higher than threshold, the risk is too great to do the operation. The intercurrent syndrome and original disease need to be treated firstly, until the score lower than the threshold the operation can be made.