Cerebral fat embolism syndrome after simultaneous bilateral total knee arthroplasty: a case series.

Total knee arthroplasty (TKA), particularly when performed as a simultaneous bilateral procedure, theoretically increases the risk for entry of fat globules into the blood stream. The frequency of cerebral fat embolism syndrome (CFES) was retrospectively investigated among 2345 simultaneous bilateral TKA procedures performed from August 2006 to May 2010. During that period, 9 patients presented with neurologic deficits after surgery and underwent brain magnetic resonance imaging. For identification of CFES among them, we used both magnetic resonance imaging findings and clinical criteria modified from the original one of Gurd and Wilson (J Bone Joint Surg Br 1974; 56B:408). Four patients fulfilled the modified criteria. The overall incidence of CFES occurring after simultaneous bilateral TKA was 0.17%. Cerebral fat embolism syndrome should be ruled out, although rare, in patients who present with neurologic impairment after TKA.

The biomechanical performance of bone block and soft-tissue posterior cruciate ligament graft fixation with interference screw and cross-pin techniques.

PURPOSE: The purpose of this study was to evaluate the biomechanical properties of 4 different graft fixation constructs on the tibial side of the posterior cruciate ligament with reconstruction by use of an Achilles tendon graft. METHODS: Biomechanical testing of 4 different fixation techniques was performed on 20 human cadaveric tibias and Achilles tendons. Cross-pin fixation with bone blocks (group A), interference screw fixation with bone blocks (group B), cross-pin fixation of soft tissue with backup fixation (group C), and interference screw fixation of soft tissue with backup fixation (group D) were tested. The tibia-graft fixation complex was cyclically loaded between 50 N and 250 N at 1 Hz for 1,000 cycles. After cycling, the amount of graft displacement was determined by measuring the change in grip-to-grip distance. The complex was then loaded to failure at 1 mm/s, and maximum failure load, stiffness, and mode of failure were determined. RESULTS: Group C had a higher maximum failure load and stiffness than groups A and B (P < .05 and P < .001, respectively) but poor results for displacement (P < .05 and P < .05, respectively). The failure modes were bone block fracture, graft laceration, or cross-pin fracture in the cross-pin groups and graft pullout in the interference screw groups. CONCLUSIONS: Our study suggests that maximum failure load and stiffness of hybrid fixation for Achilles tendon graft are comparable to those of both single calcaneal bone plug fixation methods that we studied. However, tendon graft displacement was significantly greater regardless of fixation method when compared with bone plug fixation. CLINICAL RELEVANCE: Hybrid fixation for soft-tissue graft on the tibial fixation site provides comparable biomechanical properties of bone-to-bone fixation.

Partial femoral avulsion of the posterior cruciate ligament presenting as an osteochondral defect.

A 22-year-old soldier presented with mild anterior knee pain. Routine knee radiographs and magnetic resonance imaging revealed bony fragments that suggested an osteochondral defect in the medial femoral condyle. Arthroscopy revealed the fragment originated from a posterior cruciate ligament (PCL) avulsion and a well-located intercondylar notch with a connection to the PCL fiber. An initial attempt was made to fix the fragment at the original avulsion site. However, the fragment was deformed, and the avulsion site was incongruent after reduction. The fragment was debrided accordingly, and the defect site was filled with an osteochondral graft from a nonweight-bearing portion of the lateral femoral condyle. The patient's postoperative course was uneventful, and he was able to participate in military training without discomfort.

Quality and Lactic Acid Bacteria Diversity of Pork Salami Containing Kimchi Powder.

We investigated the quality properties and bacteria diversity of pork salami containing homemade kimchi powder (KP). Pork salamis were manufactured with commercial starter culture (control), and 1% KP (KP1), 3% KP (KP3), and 5% KP (KP5). The salami was fermented and aged for 2 days and 56 days, respectively. The pH and AW values of salamis with KP were significantly lower than that of the control (p<0.05). The 2-thiobarbituric acid reactive substance values of all salamis with KP increased but were below 0.2 mg MDA/kg. Salamis with KP, decreased the L* value, but increased the a* and b* values (p<0.05). The Lactobacillus count was significantly higher in the salamis with KP than in the control by day 14 (p<0.05). The number of Leuconostoc was higher in salamis with KP than in the control and was the highest in salamis in KP1. The KP1 protected lipid oxidation and showed low TBARS value of pork salami compared to the control. This study demonstrates that KP can improve pork salami properties and can serve as a potential natural compounds for fermented meat prodcuts like Metzgerei.

Physicochemical and Functional Characterization of Blue-Shelled Eggs in Korea.

The aim of this study was to compare the quality and physicochemical characteristics of blue-shelled eggs (BE) and conventional eggs (CE). Proximate composition, quality, pH value, shell color, collagen content, fatty acid composition, total cholesterol, α-glucosidase inhibition activity, and antioxidation activity were determined. The proximate composition, general qualities, and pH values of CE and BE showed no significant differences, except in moisture composition, weight, and shell thickness. Moisture content and weight of BE were significantly lower than those of CE. However, shell thickness and weight of BE were higher than those of CE (p<0.05). Lightness of BE was significantly higher than that of CE (85.20 vs. 58.80), while redness (a*) and yellowness (b*) of BE were lower than those of CE (a*: -4.75 vs. 14.20; b*: 10.45 vs. 30.63). The fatty acid [C18:1n7 (cis-vaccenic acid) and C18:3n6 (gamma-linolenic acid)] contents of BE were significantly higher than those of CE. The total cholesterol contents of BE and CE were similar. DPPH radical scavenging activity of BE was significantly higher than that of CE (40.78 vs. 35.35). Interestingly, α-glucosidase inhibition activity of whole egg and egg yolk in BE (19.27 and 36.06) was significantly higher than that of whole egg and egg yolk in CE (13.95 and 32.46). This result indicated that BE could potentially be used as a functional food material. Further studies are required to evaluate the specific compounds that affect functional activity.

Gender differences of the morphology of the distal femur and proximal tibia in a Korean population.

PURPOSE: We conducted this study to determine whether the sizes of distal femurs and proximal tibiae in Korean men and women are different, and to assess suitability of the sizes of prostheses currently used in Korea. MATERIALS AND METHODS: We performed morphological analysis of proximal tibia and distal femur on 115 patients (56 male, 59 female) using MRI to investigate a gender difference. Tibial mediolateral dimension (tMAP), tibial medial anteroposterior dimension (tMAP), tibial lateral anteroposterior dimension (tLAP) femoral mediolateral dimension (fML), femoral medial anteroposterior dimension (fMAP), and femoral lateral anteroposterior dimension (fLAP) were measured. The ratio of tMAP and tLAP to tML (plateau aspect ratio, tAP/tML×100%), and that of fMAP and fLAP to fML (condylar aspect ratio, fAP/fML×100%) were calculated. The measurements were compared with the similar dimensions of four total knee implants currently used. RESULTS: The tML and tAP lengths showed a significant gender difference (P<0.05). The plateau aspect ratio (tMAP/tML) revealed a significant difference between male (0.74±0.05) and female (0.68±0.04, P<0.05). For morphotype of distal femur, males were found to have significantly large values (P<0.05) in the parameters, except for fLAP. With regards to the ratio of the ML width to the AP length, the women showed a narrower ML width than the men. Both genders were distributed within the range of the dimensions of the prostheses currently used prostheses. CONCLUSIONS: Korean population revealed that women have smaller dimensions than male counterparts. In both genders, a relatively small size of prostheses matches distal femur and proximal tibia better among the implants currently used in Korea.

Analysis of synovial fluid in culture-negative samples of suspicious periprosthetic infections.

Synovial fluid analysis can help to rule out a periprosthetic infection. The goal of this study was to evaluate the prognostic significance of synovial fluid suspicious for a periprosthetic infection given the synovial leukocyte count and percent of neutrophils. From August 2006 to November 2008, patients who had synovial fluid aspirated for painful knees and elevated C-reactive protein levels after total knee arthroplasty but revealed no growth of any microorganism were retrospectively evaluated by medical record review. Mean follow-up period was 827.7±250.6 days from the date of joint aspiration results. The optimal cut-off values for synovial leukocyte counts and percent neutrophils were determined using receiver operating characteristic curves. From a total of 56 patients, 14 were classified as having poor results. The remaining 42 patients had an uneventful clinical course with a stable prosthesis on radiographs without specific therapy during the follow-up period. The receiver operating characteristic curve showed that a synovial leukocyte count of 3600/uL had an 86% sensitivity and 79% specificity; with 89% synovial neutrophils, the sensitivity was 72% and specificity 62%. The synovial fluid leukocyte count and percent neutrophils were significant predictors of outcome in patients with cultures that were negative but suspicious for periprosthetic infections.

False-negative transcranial motor-evoked potentials during scoliosis surgery causing paralysis: a case report with literature review.

STUDY DESIGN: Case report. OBJECTIVE: To report a case of false-negative intraoperative motor-evoked potentials (MEP) that developed paraplegia after surgery. SUMMARY OF BACKGROUND DATA: Although several false-negative results have been reported with somatosensory-evoked potentials, there is no report noted with MEP. Therefore, several authors have preferred using MEPs as a gold standard in neuromonitoring. METHODS: We report a case of false-negative MEP during the scoliosis surgery which is the first report showing false-negative MEPs during operation. RESULTS: A 15-year-old girl with severe kyphoscoliosis (Cobb angle, 140 degrees) in neurofibromatosis was operated for correction and posterior spinal fusion surgery, using pedicle screw instrumentation. Intraoperative neuromonitoring did not show any change in MEPs throughout the procedure, however, she woke-up with paraplegia. Immediate implant release could not recover her neurology functionally at last follow-up. Positive event during the operation was massive blood loss which could not show drop in MEPs as an ischemic cord injury (probable cause). Postoperative CT scan in both patients did not show any injury with pedicle screw as implants were well placed within the pedicles. Reviewing the literature, we could not find out any prospective study in animals identifying false-negative results with MEPs. CONCLUSION: From our experience of false-negative MEPs, we conclude that unwanted events with use of MEP in scoliosis or other spinal surgeries. We propose further prospective research on animals to solve this issue.

Fracture of a polyethylene tibial post in a Scorpio posterior-stabilized knee prosthesis.

We report the case of a polyethylene tibial post fracture in a 72-year-old woman 14 months after a Scorpio posterior-stabilized (PS) total knee arthroplasty. The polyethylene wear was found around the fracture site of the post, especially over the anterior aspect of the post base. The failure mechanism of the post fracture in the present case was anterior impingement with excessive wear over the base of the anterior aspect of the tibial post, which became a stress-riser of post and cam articulation. This is the first report of a polyethylene tibial post fracture of a Scorpio PS prosthesis.