[Prevention and treatment of bearing dislocation of mobile-bearing unicompartmental knee arthroplasty].

Bearing dislocation is a special complication of mobile-bearing unicompartmental arthroplasty, caused by many factors, such as imbalance of the flexion and extension gap, malposition of components, impingement by the remaining osteophytes and cement, damage or delayed chronic laxity of medial collateral ligament, traumatic accident and habitual high knee flexion. It can be reduced by strictly controlling the operation indications before operation, osteotomy and implanting the prosthesis accurately while protecting the medial collateral ligament during operation, actively guiding the appropriate rehabilitation actions and activity intensity of patients after operation. Treatment should be individualized according to the causes and individual conditions of patients.

[Comparison of the early efficacy of unicompartmental and total knee arthroplasty in patients with medial compartmental osteoarthritis of the knee: a propensity score matching study].

Objective: To compare the short-term efficacy of unicompartmental knee arthroplasty (UKA) and total knee arthroplasty(TKA) in the treatment of medial compartmental knee osteoarthritis. Methods: A retrospective analysis was performed on 197 patients with medial compartment osteoarthritis of the knee treated by the same group of doctors from January 2015 to December 2018.There were 86 males and 111 females, aged (67.7±10.5) years (range: 46 to 92 years), among which 101 cases received UKA and 96 cases received TKA.The UKA and TKA patients were matched by the propensity score matching method, and a total of 41 pairs of patients were successfully matched.The difference of short-term outcomes between the two groups were compared by t test, χ(2) test or Fisher exact probability methods. Results: Compared with TKA group, the postoperative reduction of hemogloblin in the UKA group was lower ((15.3±6.4) g/L vs. (20.1±7.5) g/L, t=-3.117, P<0.01), opioid dosage was lower ((160.5±29.3) mg vs. (186.1±46.8) mg, t=-2.969, P<0.01), and the length of hospital stay was shorter ((7.0±2.0)d vs. (10.0±2.5)d, t=-6.000, P<0.01). Forgotten joint score of UKA group was higher ( (65.1±7.6) vs. (58.3±13.9) , t=2.732, P<0.01), the incidence of knee clunk or crepitus was lower (P=0.03) . There was no significant difference in the time of surgical tourniquet, range of motion, American knee society clinical score and incidence of deep vein thrombosis in lower extremities between the two groups.No complications such as surgical site infection, prosthesis loosening and dislocation occurred in the two groups. Conclusion: The early effect of UKA is similar to that of TKA, and it is better than TKA in the aspects of knee clunk or crepitus, forgotten joint score, blood loss, opioid dosage and postoperative hospital stay.

[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.

Growth failure and decreased bone mineral of newborn rats with chronic furosemide therapy.

To test the hypothesis that chronic furosemide treatment in otherwise healthy newborn animals may lead to lowered bone mineral [calcium (Ca) and magnesium (Mg)] content, healthy littermates within each litter of Sprague-Dawley rat pups were randomly assigned to three groups: control, low dose furosemide (5 mg/kg/day), and high dose furosemide (15 mg/kg/day). The pups were treated between days 4 and 28 postnatally. The wet and dry weights of kidneys and tibiae significantly correlated with body weights at sacrifice. Furosemide-treated pups demonstrated a dose-dependent growth delay, decreased total bone (tibiae) Ca and Mg, increased urine Ca and Mg concentration, and a significant inverse correlation between bone Ca and urine Ca concentration. There was no significant difference among the groups when bone Ca and Mg were normalized to per gram of bone dry weight. There were no significant differences among the groups with respect to bone phosphorus or urinary phosphorus concentration; kidney and serum Ca and Mg; or serum sodium, potassium, alkaline phosphatase and immunoreactive parathyroid hormone concentration. We conclude that chronic furosemide therapy leads to growth failure and to increased urinary losses of Ca and Mg. Total bone Ca and Mg in the furosemide-treated pups were diminished in proportion to growth retardation but the bone mineral content per unit of dry weight remained similar to control pups.