This study revealed that the knee arthroscopy rate in the United States was more than twofold higher than in England or Ontario, Canada, in 2006. Our study found that nearly half of the knee arthroscopic procedures were performed for meniscal tears. Meniscal damage, detected by magnetic resonance imaging, is commonly assumed to be the source of pain and symptoms. Further study is imperative to better define the symptoms, physical findings, and radiographic findings that are predictive of successful arthroscopic treatment.

Acetabular retroversion has been proposed to contribute to the development of osteoarthritis of the hip. For the diagnosis of this condition, conventional AP pelvic radiographs may represent a reliable, easily available diagnostic modality as they can be obtained with a reproducible technique allowing the anterior and posterior acetabular rims to be visible for assessment. This study was designed to: (i) determine cranial, central, and caudal anatomic acetabular version (AV) from cadaveric specimens; (ii) establish the validity and reliability of the radiographic measurements of central acetabular anteversion; and (iii) determine the validity and reliability of the radiographic ''cross-over-sign'' to detect acetabular retroversion. Using 43 desiccated pelvises (86 acetabuli) the anatomic AVs were measured at three different transverse planes (cranially, centrally, and caudally). From these pelvises, standardized AP pelvic radiographs were obtained. To directly measure central AV, a modified radiographic method is introduced for the use of AP pelvic radiographs. The validity and reliability of this radiographic method and of the radiographic crossover-sign to detect cranial acetabular retroversion were determined. The mean central and caudal anatomic AVs were approximately 208, and the mean cranial AV was 88. Cranial retroversion (AV < 08) was present in 19 of 86 hips (22%). A linear correlation was found between the central and cranial AV. Below 108 of central AV, all acetabuli were cranially retroverted. Between 108 and 208, 30% of the acetabuli were cranially retroverted, and above 208, only 1 of 45 acetabuli was cranially retroverted. The radiographic measurement of the central AV (20.3 AE 6.58) correlated strongly with the anatomic AV (20.1 AE 6.48). The sensitivity of the cross-over-sign to detect a cranial acetabular anteversion of less than 48 was 96%, its specificity 95%, and the positive predictive and negative predictive values 90% and 98%, respectively. Both the modified radiographic anteversion measurements and the cross-over-sign demonstrated substantial inter-and intraobserver reliability. Retroversion is almost exclusively a problem of the cranial acetabulum. The cranial AV is on average 128 lower than the central AV, with the latter directly measurable from AP pelvic radiographs. A central AV of less than 108 was associated with cranial retroversion. The presence of a positive cross-over-sign is a highly reliable indicator of cranial AV of <48. ß

With greater than 70% good or excellent results, fresh osteochondral allograft transplantation is a successful surgical treatment for osteochondritis dissecans of the femoral condyle.

The local delivery of antibiotics in the treatment of osteomyelitis has been used safely and effectively for decades. Multiple methods of drug delivery have been developed for the purposes of both infection treatment and prophylaxis. The mainstay of treatment in this application over the past 20 years has been non-biodegradable polymethylmethacrylate, which has the advantages of excellent elution characteristics and structural support properties. Biodegradable materials such as calcium sulfate and bone graft substitutes have been used more recently for this purpose. Other biodegradable implants, including synthetic polymers, are not yet approved for use but have demonstrated potential in laboratory investigations. Antibiotic-impregnated metal, a recent development, holds great promise in the treatment and prophylaxis of osteomyelitis in the years to come.

Patients younger than fifty years of age had a significantly higher risk of undergoing revision due to periprosthetic joint infection or to aseptic mechanical failure at one year after primary total knee arthroplasty.

Simultaneous-bilateral total knee arthroplasty was associated with a clinically important reduction in the incidence of periprosthetic joint infection and malfunction within one year after arthroplasty, but it was associated with a moderately higher risk of an adverse cardiovascular outcome within thirty days. If patients who are at higher risk for cardiovascular complications can be identified, simultaneous-bilateral knee arthroplasty may be the preferred surgical strategy for the remaining lower-risk patients.

Prophylactic parenteral antibiotics have contributed to the present low rate of surgical site infections following hip and knee arthroplasty. Over the past decade, there has been a change in the pattern of methicillin-resistant Staphylococcus aureus infections from hospital-acquired to community-acquired. The findings of recent studies on screening programs to identify carriers of methicillin-resistant Staphylococcus aureus have been equivocal, with some studies showing that such programs reduce the rate of infections and others showing no effect on infection rates. Hospitals with antibiogram data that reveal high Staphylococcus resistance should consider use of vancomycin as a prophylactic antibiotic.

Several studies support the concept that, for optimum range of motion in THA, the combined femoral and acetabular anteversion should be some constant or fall within some "safe zone." When using a cementless femoral component, the surgeon has little control of the anteversion of the component since it is dictated by native femoral anteversion. Given this constraint, we asked whether the surgeon should use the native anteversion of the acetabulum as a target for implant position in THA. Forty-six patients scheduled for primary THA underwent CT scanning and preoperative planning using a computer workstation. The native acetabular anteversion and the native femoral anteversion were measured. Prosthetic femoral anteversion was measured on the workstation by three-dimensional templating of a straight-stemmed tapered implant. The mean of the sum of the native acetabular anteversion and native femoral anteversion was 28.9 degrees; however, 17% varied by 10 degrees to 15 degrees and 11% by more than 15 degrees. The mean of native femoral anteversion and prosthetic femoral anteversion was 13.8 degrees (range, -6.1 degrees-32.7 degrees) and 22.5 degrees (range, 1 degrees-39 degrees), respectively. Based on our data, we believe the surgeon should not use the native acetabular anteversion as a target for positioning the acetabular component.