Cement use in total knee arthroplasty: 40 versus 80 grams.

BACKGROUND: Studies of cement use in total knee arthroplasty (TKA) have historically addressed mechanical properties and application strategies. Recently, cement technique has been studied as a means to reduce cost. We transitioned from opening two bags (80 grams) of cement to one bag (40 grams) of cement for primary TKA to improve cost efficacy. This study investigates the radiographic outcome and cost of TKAs performed with 40 versus 80 grams of cement. METHODS: TKAs from January 2017 to January 2019 were evaluated. Cement mantle and implant alignment were assessed per the Modern Knee Society Radiographic Evaluation System at four months by three blinded reviewers. Data was analyzed according to quantity of cement used. Cement mantle quality at 16 implant zones was compared. Cost was evaluated. RESULTS: 163 patients (age 66.8 yrs. +/- 8.9, 51.5% female) underwent TKA with 80 grams of cement, while 142 patients (age 67.1 yrs. +/- 9.3, 56.3% female) underwent TKA utilizing 40 grams of cement. There was no significant difference in cement mantle quality. The most common zone of cement deficiency was the femoral posterior flange (9% in 40 gram group versus 4% in 80 gram group, p value = 0.08). There was no difference in implant size. Cost saving was calculated at $7,810 for the 40 gram group. CONCLUSION: There was no difference in radiographic cement mantle appearance between primary knees performed with 40 or 80 grams of cement. Cement usage represents a target for cost saving and opportunity to increase the value of primary TKA. Based on the current incidence of TKA in the United States, cost savings could exceed 33 million dollars annually.

Operative Treatment of Acute Patellar Tendon Ruptures.

BACKGROUND: The gold standard for patellar tendon repair is a transosseous technique. Suture anchor repair has gained popularity, with recent biomechanical studies demonstrating significantly less gap formation during cyclic loading and significantly higher ultimate failure loads as compared with transosseous repair. These findings have not been substantiated in a large clinical cohort. PURPOSE: To report demographic and epidemiologic data, clinical and surgical findings, and outcomes and complications of anchor and transosseous suture repairs of acute patellar tendon ruptures. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: All patients who underwent a primary repair of a traumatic patellar tendon rupture within 45 days of injury between 2006 and 2016 were retrospectively reviewed. Surgery was performed at a multisurgeon (120 surgeons) multicenter (14 centers) community-based integrated health care system. Patient demographic information, repair type, complications, and time from surgery to release from medical care were recorded. RESULTS: A total of 361 patients (374 knees) met our inclusion criteria. The mean age was 39.8 years (range, 9-86 years), and 91.7% were male. There were 321 transosseous and 53 anchor repairs. There was no significant difference in the mean age (P = .27), sex (P = .79), tourniquet time (P = .93), or body mass index (P = .78) between the groups. There was a significant difference in rerupture rate between transosseous and anchor repairs (7.5% vs 0%, respectively; P = .034). Based on logistic regression, transosseous repair had 3.24 times the odds of reoperation verseus anchor repair (95% CI, 0.757-13.895; P = .1129). The infection rate was 1.6% for transosseous repair and 7.5% for anchor repair (P = .160). There was no difference in time to release from medical care: 18.4 weeks for anchor and 17.1 weeks for transosseous repairs (P = .92). CONCLUSION: Anchor repair demonstrated a significant decrease in rerupture rate when compared with transosseous repair. There was no difference in reoperation rate, infection rate, or time to release from medical care.

Clinical outcome evaluation of intraosseous vancomycin in total knee arthroplasty.

BACKGROUND: Vancomycin is a commonly used prophylactic antibiotic for total joint replacement surgery to protect against methicillin-resistant Staphylococcus aureus. Studies have suggested intraosseous (IO) infusions provide superior local tissue antibiotic concentration compared with intravenous (IV) access in total knee arthroplasty (TKA). We reviewed patients receiving IO vancomycin before TKA, comparing complication rates to a matched group receiving IV prophylactic vancomycin. METHODS: Retrospective review of TKA patients administered IO vancomycin (500 mg vancomycin in 200 mL normal saline), September 1, 2018 to March 1, 2019, was compared with TKAs performed with prophylactic IV vancomycin, January 1, 2018 to August 31, 2018. Before incision, an IO needle was inserted into the tibial tubercle region, delivering 100 mL of the mixed vancomycin solution. The needle was then removed and inserted into the distal femur, delivering 100 mL of the solution. Evaluation included preoperative and postoperative creatinine values, tourniquet time, and knee-related 30-day and 90-day complications. Data for primary and revision TKA surgery cases were analyzed independently. RESULTS: There were 100 primary and 29 revision TKA cases in the control (IV) arm and 100 primary and 19 revision TKA cases in the intervention (IO) arm, comprising a study group of 248 cases. There were fifteen 30-day complications and eighteen 90-day complications overall. No significant differences in the complication rate or creatinine values were identified between IO and IV groups. CONCLUSIONS: IO vancomycin has an adequate safety profile in primary and revision TKA, eliminating the logistical challenge of timely prophylactic antibiotic administration.

Vascular KCNQ (Kv7) potassium channels as common signaling intermediates and therapeutic targets in cerebral vasospasm.

Cerebral vasospasm after subarachnoid hemorrhage (SAH) is characterized by prolonged severe constriction of the basilar artery, which often leads to ischemic brain damage. Locally elevated concentrations of spasmogenic substances induce persistent depolarization of myocytes in the basilar artery, leading to continuous influx of calcium (Ca) through voltage-sensitive Ca channels and myocyte contraction. Potassium (K) channel openers may have therapeutic utility to oppose membrane depolarization, dilate the arteries, and reduce ischemia. Here, we examined the involvement of vascular Kv7 K channels in the pathogenesis of cerebral vasospasm and tested whether Kv7 channel openers are effective therapeutic agents in a rat model of SAH. Patch-clamp experiments revealed that 3 different spasmogens (serotonin, endothelin, and vasopressin) suppressed Kv7 currents and depolarized freshly isolated rat basilar artery myocytes. These effects were significantly reduced in the presence of a Kv7 channel opener, retigabine. Retigabine (10 µM) also significantly blocked L-type Ca channels, reducing peak inward currents by >50%. In the presence of a selective Kv7 channel blocker, XE991, the spasmogens did not produce additive constriction responses measured using pressure myography. Kv7 channel openers (retigabine or celecoxib) significantly attenuated basilar artery spasm in rats with experimentally induced SAH. In conclusion, we identify Kv7 channels as common targets of vasoconstrictor spasmogens and as candidates for therapeutic intervention for cerebral vasospasm.