A moderate-intensity static magnetic field enhances repair of cartilage damage in rabbits.

BACKGROUND AND AIMS: Electromagnetic fields have been proposed to enhance healing of cartilage defects by stimulation of chondrocyte proliferation, proteoglycan synthesis as well as decreasing pain and improving motion in osteoarthritic patients. However, the effects of a moderate-intensity static magnetic field on cartilage repair have not been investigated. This study tries to determine the effects of a moderate-intensity permanent magnetic field of 40 mT on cartilage repair. METHODS: Defects of 3 mm in diameter and 6 mm in depth were made on the weight bearing surface of the right medial femoral condyle of 30 rabbits. The animals were divided randomly into three equal groups (magnet, sham and control). In the magnet group, cylindrical permanent magnets were implanted subcutaneously medial to the medial femoral condyle, while in the sham group the cylindrical ceramic were not magnetized, and nothing was implanted in controls. After 12 weeks of observation, Mankin's microscopic scoring was done on all specimens, and irregularity of surface characteristics, cell colonization, hypocellularity, cartilage matrix formation, and presence of empty lacunae were investigated. RESULTS: Each of these characteristics showed significant differences in magnet group relative to control and sham groups (p <0.05). Mankin's score was 1.6 ± 0.6 in magnet group, 7.2 ± 1.6 in sham group and 7.7 ± 1 in control group (p <0.001). CONCLUSIONS: [corrected] In this animal study, microscopic Mankin's scoring depicted histological improvement in cartilage of magnet group.

Arthroscopic anterior cruciate ligament reconstruction with modified "wireless" cross-screw transfix femoral fixation.

Among several graft fixation options in arthroscopic ACL reconstruction for hamstring tendons, transcondylar fixation has been suggested to offer mechanical advantages compared to other femoral fixation systems. Blind nature of the procedure may result in several complications including iliotibial band irritation syndrome, breakage of the bio absorbable cross-pin, stress fracture of the femoral cortex, and more commonly intraoperative wire loop twisting, resulting in fixation failure, wire breakage or graft laceration. We used "wireless" transfixation technique to avoid complications associated with wire loop.

A modification of tibial inlay fixation in posterior cruciate ligament reconstruction by interference screw: a biomedical study on calf tibial bone model.

This study presents a modification of tibial inlay technique in posterior cruciate ligament (PCL) reconstruction and evaluates the structural properties of tibial side fixation of the graft, comparing tibial inlay technique and a new modification, that is interference screw fixation of tibial side of the graft in suggested supine position which is more applicable, with less potential intraoperative neurovascular complications. Forty fresh calf knees that were prepared from 20 healthy 3 years old calves which were between 200 and 220 kg were the subject of this study. The tibias were separately used simulating tibial side PCL reconstruction with tibial tuberosity-patellar tendon-patellar bone graft. Tibial side of the graft was fixed using two cancellous screws in 20 tibiae and with interference screw in obliquely oriented canal in another 20 tibiae. Load-to-failure test was carried out on ten samples from each group. The remaining samples were used for cycling loading. Mann-Whitney U test was used to compare structural properties of each group. No significant differences were observed between two methods at load-to-failure test; but mean elongation at 1,000 cycles of new modification was significantly lower than tibial inlay technique.

Procrastination of wound drainage and malnutrition affect the outcome of joint arthroplasty.

UNLABELLED: The association between wound drainage and subsequent periprosthetic infection is well known. However, the most appropriate treatment of wound drainage is not well understood. We retrospectively reviewed the records of 10,325 patients (11,785 procedures), among whom 300 patients (2.9%) developed persistent (greater than 48 hours postoperatively) wound drainage. Wound drainage stopped spontaneously between 2 and 4 days in 217 patients treated with local wound care and oral antibiotics. The remaining 83 patients (28%) underwent further surgery. A single débridement resulted in cessation of drainage without subsequent infection in 63 of 83 patients (76%), whereas 20 (24%) patients continued to drain and underwent additional treatment (repeat débridement, resection arthroplasty, or long-term antibiotics). Timing of surgery and the presence of malnutrition predicted failure of the first débridement. There were no differences between the success and failure groups with regard to all other examined parameters, including demographic or surgical factors. LEVEL OF EVIDENCE: Level III, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Determining "true" leukocytosis in bloody joint aspiration.

This study intends to determine the diagnostic value of implementing a corrective formula that can adjust for serum leukocytes in bloody joint fluid. Our cohort included 91 infected and 37 aseptic total knee arthroplasties. Joint fluid leukocyte count (>1760/microL) and neutrophil percentage (>73%) were the cutoff values for deep infection. The adjusted fluid leukocyte counts were calculated using the following simple formula: WBCadjusted=WBCobserved-[(WBCblood x RBCfluid/RBCblood)]predicted. Adjusted fluid cell counts of only 5 infected patients dropped below the cutoff value, whereas the remaining 86 maintained a high cell count. Ten noninfected patients had false-positive cell counts, 6 of which were successfully corrected to levels below the designated thresholds. The aspirates that were corrected had a greater number of introduced white blood cells. This study suggests that our corrective formula can detect false-positive joint aspirations without jeopardizing the diagnosis of periprosthetic infection.

Hip pain in young adults: femoroacetabular impingement.

Femoroacetabular impingement is a more recently noticed cause of hip pain in young patients, and early diagnosis and treatment are critical to prevent development of osteoarthritis and/or delay the need for a more radical treatment option such as arthroplasty surgery. Two general types of femoroacetabular impingement have been described. In the cam impingement, the femoral deformity, usually a bump on the head-and-neck junction, impinges on the acetabular rim. The pincer type of impingement is caused by the deformity on the acetabular side, which may be a deep socket, or an acetabular overcoverage due to retroversion that creates an obstacle for flexion and internal rotation. This article attempts to examine the underlying pathogenesis and discusses diagnostic and treatment modalities.