Intraoperative computer navigation parameters are poor predictors of function 1 year after total knee arthroplasty.

Intraoperative navigation data were collected prospectively for 134 knees undergoing cemented, posterior-stabilized total knee arthroplasty. Partial least squares regression analysis was used to test the association between patient demographics and intraoperative data collected with a computer-assisted navigation system (coronal alignment, ligament balance, range of motion, external tibiofemoral rotation) with 1-year outcomes (36-item Short-Form Health Survey, Oxford Knee Score, range of motion). Age at surgery displayed the largest coefficients of any other predictor. In contrast, navigation coefficients were variable in the strength and direction of their association with the outcome variables. Static knee alignment data obtained intraoperatively have limited capacity to explain the variance in functional outcome at 1 year. Although alignment and component position can be precisely measured intraoperatively, intrinsic patient factors remain dominant in determining the outcome.

Unsatisfactory accuracy as determined by computer navigation of VISIONAIRE patient-specific instrumentation for total knee arthroplasty.

This investigation evaluated the Smith and Nephew VISIONAIRE patient-specific cutting block (PSCB) system for total knee arthroplasty. A consecutive series of 60 patients was recruited. Intraoperative computer navigation was used to evaluate the accuracy of the cutting blocks in the coronal and sagittal planes for the tibia, as well as rotational plane for the femur. The PSCB would have placed 79.3% of the sample within ±3° of the preoperative plan in the coronal plane, while the rotational and sagittal alignment results within ±3° were 77.2% and 54.5% respectively. The VISIONAIRE PSCB system achieved unacceptable accuracy when assessed by computer navigation. There might be many sources of error, but caution is recommended before using this system routinely without objective verification of alignment.

Is femoral nerve block necessary during total knee arthroplasty?: a randomized controlled trial.

There remains a lack of randomized controlled trials comparing methods of perioperative analgesia for total knee arthroplasty. To address this deficiency, a blinded, randomized controlled trial was conducted to compare the use of femoral nerve block (group F) and local anesthetic (group L). A sample of 55 patients who met the inclusion criteria were randomized to either group. No significant differences in the most severe pain score or 36-Item Short Form Health Survey, The Western Ontario and McMaster Universities Arthritis Index (WOMAC), or Oxford scores were observed between groups. However, the Knee Society score was significantly higher in group F. In addition, group F used significantly fewer micrograms of intravenous fentanyl in the first 24 hours. Balancing the risks of femoral nerve block with those of increased systemic narcotic delivery should be performed on a case-by-case basis.

The use of linezolid in the treatment of infected total joint arthroplasty.

Fourteen patients with a diagnosis of infected total joint arthroplasty treated by 1 or 2-stage revision and a course of oral linezolid were reviewed. Patients were assessed according to McPherson stage, inflammatory markers, nature of surgery, use of antibiotics, pathogen isolated, and outcome at follow-up. Pathogens isolated were coagulase-negative staphylococcus, multiresistant Staphylococcus aureus, Enterobacter cloacae, and mixed growth. McPherson stages were 1 IB2, 1 IA3, 1 II A2, 3IIIA2, 2 IIIB1, 3 IIIB2, 1 IIIB3, 1 IIIC2, and 1 IIIC3. All patients showed resolution of infection, with normalization of inflammatory markers after treatment. Mean length of follow-up is 32.7 months (range, 9-44 months). Comparison is drawn with previous studies highlighting the good results achievable with the use of this antibiotic. Although no substitute for adequate surgical management, it does allow oral treatment and therefore avoids the difficulties associated with long-term intravenous antibiotic therapy.

Cruciate ligament reconstruction.

Injuries to the cruciate ligaments of the knee can be disabling. Advances in treatment over recent years have made their early diagnosis imperative. Surgical reconstruction is not appropriate for all. Once surgical candidates have been identified a number of reconstructive options exist.