Analysis Of Body Mass Index On Short-medium Term Effect Of Unicompartment Knee Arthroplasty

Background:The association of postoperative effects and obesity after total knee arthroplasty(TKA)has been well described.However,the effect of body-mass index(BMI)on postoperative complications after unicompartmental knee arthroplasty(UKA)is controversial.Objective:To investigate the efficacy of body mass index(body mass index,BMI)in the treatment of anterior medial compartmental osteoarthritis of knee joint with unicompartment knee arthroplasty(UKA).Material and Methods:The clinical data of 55 patients(61 knee)with anterior medial ventricular osteoarthritis of knee joint treated with minimally invasive UKA in May 2014-2019were retrospectively analyzed.According to BMI,the patients were divided into three groups:normal body mass group(A group,BMI 18.5～24.99 kg/m2)23 cases(25knee),overweight group(B group,BMI 25～29.99 kg/m2)23 cases(25 knee),obesity group(C group,BMI 309.99 kg/m2)9 cases(11 knee).The three groups were recorded for gender,age,lateral,course,and preoperative U.S hospital for special surgery(HSS)score,pain visual analogue score(VAS),knee motion(range of motion,ROM)and compared whether the three groups had differences before operation.Intraoperative indexes were recorded in 3 groups:operative time,intraoperative dominant blood loss,and decreased hemoglobin at 1 week after operation.The evaluation indexes of knee function and pain after operation were recorded:HSS score,VAS score and ROM.score The HSS scores,VAS scores and ROM of three groups were compared.After the operation,we observed and recorded whether the patients in the three groups had knee joint infection,deep venous thrombosis of the lower extremity and the last follow-up X to observe whether there were complications such as periprosthetic fracture,gasket dislocation and so on.Results:All 55 patients were followed up for a minimum of 5 months and a maximum of60 months,with an average of 24 months.preoperative related indicators:normal body mass group(A group):HSS:51.6±2.9 score,VAS:5.7±0.8 score;ROM:100.3±10.4°.overweight group(B group):HSS:52.7±5.5 score;VAS:5.8±0.8 score,ROM:96.4±10.7°.obesity group(C group):HSS:51.0±4.6 score,VAS:5.2±0.6 score,ROM:96.4±8.6°.Before operation,there was no statistical difference between the three groups(P>0.05).Table 1.Intraoperative indicators:normal body mass group(A group):operative time:94.5±9.2 minutes;intraoperative dominant blood loss:74.2±14.9 ml;postoperative 1 week hemoglobin drop:1.6±0.5 g/l;overweight group(B group):operative time 95.3±8.6.3±8.6 minutes;intraoperative dominant blood loss:78.9±9.3 ml;1 week after operation,hemoglobin drop:1.5±0.5 g/l;obesity group(C group):operation time 90.2±7.0 min;intraoperative dominant blood loss79.3±9.3 ml;hemoglobin drop 1.6±0.8 g/l 1 week after operation.Comparison of operative time,intraoperative dominant blood loss and one week after operation showed no statistical difference(P>0.05).Table 2.Postoperative related indicators:normal body mass group(A group):HSS:78.7±7.9 score;VAS:0.7±0.8 score;ROM:108.3±8.8°;overweight group(B group):HSS:75.4±7.5 score;VAS:0.7±0.8score;ROM:107.0±9.2°;obesity group(C group):HSS:76.1±5.2 score;VAS:0.5±0.5score;ROM:105.4±10.2°.There was no difference in postoperative HSS score,VAS score and ROM between the three groups(P>0.05).Table 3.The HSS scores,VAS scores and ROM of the three groups were significantly improved compared with those before operation(P<0.05).Table 4.There were no complications such as knee infection,deep venous thrombosis and so on.After operation,the positive and lateral position X line film of knee joint showed no signs of periprosthetic fracture,loosening,dislocation of gasket,wear and tear,and the position of prosthesis was good.Conclusion:Small samples of obese(BMI≥30.00 kg/m~2)and overweight(BMI≥39.99kg/m~2)patients with anterior and medial osteoarthritis of the knee can achieve satisfactory short-and medium-term efficacy using a minimally invasive approach activity platform.Long-term efficacy needs further follow-up observation and further confirmation by larger sample size or multicenter studies.