[Unilateral patellar resurfacing in bilateral total knee arthroplasty: a randomized controlled study]

OBJECTIVE

To perform unilateral patellar resurfacing and contralateral patellar retention in bilateral total knee arthroplasty (TKA) randomly, and to compare the clinical effects of patellar retention with patellar resurfacing in TKA.

METHODS

In the study, 14 bilateral knee osteoarthritis (OA) patients were randomized in the bilateral TKA to receive unilateral patellar resurfacing and contralateral patellar retention, including 28 knees, all were females, 53 to 78 years old, with average (66.9±7.8) years, and the BMI was (26.3±1.8) kg/m². All subjects were followed up from 3 to 12 months. The clinical effects were evaluated based on measurements of American Knee Society score (KSS), range of motion (ROM), anterior knee pain, patellar clunk, and patellar tilt angle (PTA).

RESULTS

All the wounds healed primarily without significant complications, such as infection, aseptic loosening, patellar fracture and so on. The preoperative KSS scores of patellar resurfacing group were 38.9±22.2, and the scores changed to be 92.4±6.7 after operation, which were added by 53.5±20.3. While in the patellar retention group, the KSS scores were 38.4 ± 20.5 preoperatively, and after operation, which were added to be 92.1±4.2, and improved by 53.7±21.4. The differences in the changed KSS scores between TKA with and without patellar resurfacing were not statistically significant (Independent t-test, P=0.98). The ROM was changed from 95.4°±13.5° preoperatively to 120.4°±8.9° postoperatively in the patellar resurfacing group and from 92.9°±19.1° preoperatively to 120.4±8.4° postoperatively in the patellar retention group. The ROM of the two group were increased by 25.0°±14.5° and 27.5°±19.4° respectively. However, no remarkable differences were observed between the 2 groups in the knee ROM (Independent t-test, P=0.70). At the end of the latest follow-up, 3 knees in the patellar resurfacing group and 2 knees in the patellar retention group had knee anterior pain, the incidences of anterior knee pain were 21.4% and 14.3% respectively. There was no obvious difference for the incidence of post-operative anterior knee pain (Chi-square test, P=0.62). The incidences of post-operative patellar clunk in the 2 groups were all with 3 knees (21.4%), which had no significant difference in the 2 groups (Chi-square test, P=1.00). The post-operative PTA were 2.6°±2.6° in the patellar resurfacing group and 3.6°±2.9° in the patellar retention group, respectively. There was also no statistical difference between the 2 groups (Chi-square test, P=0.36).

CONCLUSION

For knee OA patients with mild or moderate patellar cartilage damage, performing patellar resurfacing or not didn't significantly affect anterior knee pain, patellar clunk, functional outcomes or patellar tracking after TKA. So we suggest retain patella in TKA for OA patients with mild or moderate patellar cartilage damage.

[The multicenter study on the registration and follow-up of low anticoagulation therapy for the heart valve operation in China]

OBJECTIVE

To investigate the optimal anticoagulation methods and monitoring strategy for Chinese patients undergoing heart valve replacement, which is potentially quite different from western populations.

METHODS

In this multicenter prospective cohort study, the anticoagulation and monitoring strategy data was acquired from 25 773 in-hospital patients in 35 medical centers and 20 519 patients in outpatient clinic in 11 medical centers from January 1st, 2011 to December 31th, 2015.

RESULTS

As for in-hospital patients, mean age of study population was (48.6±11.2) years old; main etiology of valve pathology was rheumatic (87.5%) origin among study cohort; 94.8% of study population received mechanical valve implantation; international normalized ratio (INR) monitoring (in all the study centers) and low-intensity anticoagulation strategy (31 hospitals chose target INR range of 1.5-2.5, and actual values of INR among 89.2% of 100 069 in-hospital monitoring samples were 1.5-2.5), with mean actual INR values of 1.84±0.53, and warfarin dosage of (2.82±0.93) mg/d were widely adopted among the study centers; strategies of in-hospital warfarin administration were similar in all the study centers; complication rates of low-intensity anticoagulation strategy were low in severe hemorrhage (0.02%), thrombosis (0.05%), and thromboembolism (0.05%) events, without anticoagulation-related death.As for 18 974 outpatient clinic patients, the follow-up rate was 92.47%, with a total of 30 012 patient-years (Pty). Anticoagulation-related morbidity and mortality rates were 0.67% and 0.15% Pty; major hemorrhage morbidity and mortality rates were 0.25% and 0.13% Pty; thromboembolism morbidity and mortality rates were 0.45% and 0.03% Pty.The mean dosage of warfarin daily dosage was (2.85±1.23) mg/d and INR value was 1.82±0.57.No significant regional difference in the intensity of anticoagulation therapy was noted during the study.

CONCLUSIONS

INR can be used as a normalized indicator for intensity of anticoagulation therapy in China.The optimal anticoagulation intensity with INR range from 1.5 to 2.5 is safe and effective for Chinese patients with heart valve replacement, and there is no significant regional difference in the intensity of anticoagulation therapy.

Open-heart surgery in patients with liver cirrhosis: indications, risk factors, and clinical outcomes

BACKGROUND

Because of recent advances in cardiopulmonary bypass (CPB) surgery, there are broadened indications to approach patients with a high operative risk. Meanwhile, there is an increasing number of patients with severe liver dysfunction subjected to open-heart surgery. This retrospective study was designed to evaluate the operative indications and clinical outcomes in patients with liver cirrhosis (LC) undergoing open-heart surgery. In addition, determinants influencing their prognosis were assessed.

PATIENTS AND METHODS

Between May 1996 and June 2005, 24 patients with LC underwent CPB open-heart surgery in our institution. The preoperative severity of the LC was determined according to the Child-Pugh classification. Their perioperative data were analyzed. Several perioperative factors were compared by multivariate logistic regression analysis between survivors and nonsurvivors to determine possible risk factors contributing to mortality.

RESULTS

There were 14 females and 10 males. Their age ranged from 36 to 72 (mean 53 +/- 13) years. Seventeen cases were classified as having Child-Pugh class A LC, 6 as having Child-Pugh class B, and 1 as having Child-Pugh class C LC. All patients underwent CPB surgery. The mean operation time and the cross-clamp time were 160 +/- 53 and 90 +/- 42 min, respectively. During the first 24 h after the operation, the mean chest tube output was 1,080 +/- 320 ml. The mean duration of mechanical ventilation was 32 +/- 22 h, and the mean intensive care unit stay was 11 +/- 8 days. Sixty-six percent of the patients experienced significant morbidity. Fifty-three percent of the patients with Child-Pugh class A LC and 100% of those with Child-Pugh class B and C LC suffered postoperative complications. The overall mortality rate was 25%. The postoperative mortality rates of the patients with Child-Pugh class A, B, and C LC were 6, 67, and 100%, respectively. Preoperative serum total bilirubin and cholinesterase levels and EuroSCORE (European System for Cardiac Operative Risk Evaluation) values along with CPB time were identified as the important predictors to differentiate between survivors and nonsurvivors by multivariate logistic regression analysis.

CONCLUSIONS

The Child-Pugh class is associated with hepatic decompensation and mortality after open-heart CPB surgery in patients with LC. Such surgery can be performed safely in patients with a Child-Pugh class A LC. But cardiac interventions using CPB in patients with more advanced LC are associated with high mortality and morbidity rates. The preoperative total plasma bilirubin and cholinesterase concentrations as well as the EuroSCORE along with the CPB time are identified as statistically significant predictors of mortality after open-heart surgery in patients with LC. Our findings indicate that patients with chronic liver disease scheduled for open-heart surgery should be carefully evaluated before the operation and that the CPB duration should be as short as possible.