Quantitative Proteomic Analysis of Changes Related to Age and Calorie Restriction in Rat Liver Tissue.

Calorie restriction (CR) is the most frequently studied mechanism for increasing longevity, protecting against stress, and delaying age-associated diseases. Most studies have initiated CR in young animals to determine the protective effects against aging. Although aging phenomena are well-documented, the molecular mechanisms of aging and CR remain unclear. In this study, we observe changes in hepatic proteins upon age-related and diet-restricted changes in the rat liver using quantitative proteomics. Quantitative proteomes are measured using tandem mass tag labeling followed by LC-MS/MS. We compare protein levels in livers from young (6 months old) and old (25 months old) rats with 40% calorie-restricted (YCR and OCR, respectively) or ad libitum diets. In total, 44 279 peptides and 3134 proteins are identified and 260 differentially expressed proteins are found. Functional enrichment analysis show that these proteins are mainly involved in glucose and fatty acid metabolism-related processes, consistent with the theory that energy metabolism regulation is dependent on age-related and calorie-restricted changes in liver tissue. In addition, proteins mediating inflammation and gluconeogenesis are increased in OCR livers, but not YCR livers. These results show that CR in old rats might not have antiaging benefits because liver inflammation is increased.

Second-look arthroscopic findings after open-wedge high tibia osteotomy focusing on the posterior root tears of the medial meniscus.

PURPOSE: This study examined, at second-look arthroscopy, the results of open-wedge high tibial osteotomy (HTO) focusing on root tear of the medial meniscus posterior horn (RTMMP). METHODS: Among 31 consecutive patients who underwent HTO without a meniscectomy or pullout repair for RTMMP, 20 patients were available for second-look arthroscopic evaluation. All patients had medial unicompartmental arthritis. The healing status of the RTMMP was classified as complete, incomplete, and no healing. The difference in the weight bearing line from presurgery to the last follow-up was evaluated. Osteoarthritis and chondral lesions were evaluated, as were clinical results. Correlations between healing status and other variables (weight bearing line, cartilage status, and clinical scores) were assessed. The healed (10 patients) and nonhealed (incomplete 6 patients + no healing 4 patients) groups were also evaluated with respect to other variables. RESULTS: There were 10 (50%) cases with complete healing, 6 (30%) with incomplete healing, and 4 (20%) with no healing. Kellgren-Lawrence grade did not improve according to the standing plain radiograph (P = .09). Progression of chondral lesions was not observed at second-look arthroscopy; some improvement was even observed (P = .002). The median Lysholm score improved from 58 preoperatively to 88.5 at the last follow-up. The median Hospital for Special Surgery (HSS) score also increased significantly from 62.4 (range, 50 to 76) to 87.2 (range, 80 to 92; P = .003). The comparison between healed and nonhealed groups revealed no statistical differences in all variables. CONCLUSIONS: This study revealed a high rate of healing of RTMMP after HTO without attempted repair. Healing of the meniscus was not associated with an improved clinical outcome. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Does press-fit technique reduce tunnel volume enlargement after anterior cruciate ligament reconstruction with autologous hamstring tendons? A prospective randomized computed tomography study.

PURPOSE: The purpose of this prospective, randomized, computed tomography-based study was to investigate whether the press-fit technique reduces tunnel volume enlargement (TVE) and improves the clinical outcome after anterior cruciate ligament reconstruction at a minimum follow-up of 1 year compared with conventional technique. METHODS: Sixty-nine patients undergoing primary ACL reconstruction using hamstring autografts were randomly allocated to either the press-fit technique group (group A) or conventional technique group (group B). All patients were evaluated for TVE and tunnel widening using computed tomography scanning, for functional outcome using International Knee Documentation Committee and Lysholm scores, for rotational stability using the pivot-shift test, and for anterior laxity using the KT-2000 arthrometer at a minimum of 1-year follow-up. RESULTS: There were no significant differences in TVE between the 2 groups. In group A, in which the press-fit technique was used, mean volume enlargement in the femoral tunnel was 65% compared with 71.5% in group B (P = .84). In group A, 57% (20 of 35) of patients developed femoral TVE compared with 67% (23 of 34) of patients in group B (P = .27). Both groups showed no significant difference for functional outcome (mean Lysholm score P = .73, International Knee Documentation Committee score P = .15), or knee laxity (anterior P = .78, rotational P = .22) at a minimum follow-up of 1 year. CONCLUSIONS: In a comparison of press-fit and conventional techniques, there were no significant differences in TVE and clinical outcome at short-term follow-up. LEVEL OF EVIDENCE: Level II, therapeutic study, prospective randomized clinical trial.

Incidence of bilateral discoid lateral meniscus in an Asian population: an arthroscopic assessment of contralateral knees.

PURPOSE: To investigate the incidence of bilateral discoid lateral meniscus (DLM) and to evaluate the arthroscopic features of lateral meniscus in asymptomatic contralateral knees in an Asian population who presented with symptomatic DLMs. METHODS: This study prospectively enrolled 52 consecutive patients who underwent arthroscopic procedures for symptomatic DLMs (31 complete and 21 incomplete) and who consented to the examination of the contralateral knee at the time of arthroscopy. Types of DLMs and of meniscus tears were assessed by use of arthroscopic findings. Preoperative and postoperative functional outcomes were evaluated with Lysholm and Tegner activity scores. RESULTS: Arthroscopic examinations showed 21 complete DLMs, 19 incomplete DLMs, 11 normal lateral menisci, and 1 ring-shaped lateral meniscus in contralateral knees. The incidence of bilateral DLM in our study population was 79% (41 of 52 contralateral knees). Furthermore, 65% of patients (34 pairs of knees) had the same DLM types. In addition, 3 pairs of knees with complete DLMs had menisci of different thicknesses. DLM tears were observed in 2 contralateral knees (1 radial and 1 longitudinal) and were treated by partial central meniscectomy. CONCLUSIONS: This study provides evidence of the high prevalence of bilateral DLM in an Asian population.

Second-look arthroscopic assessment of arthroscopic single-bundle posterior cruciate ligament reconstruction: comparison of mixed graft versus achilles tendon allograft.

BACKGROUND: Although controversy continues over the choice of graft tissue, including autografts, allografts, and synthetic ligaments, for posterior cruciate ligament (PCL) reconstruction, the use of a mixed graft consisting of a hamstring (semitendinosus and gracilis) autograft plus tibialis anterior allograft tendon has not been studied in detail. HYPOTHESIS: Outcomes of PCL reconstructions performed with a mixed graft would be superior to those using solely an Achilles tendon allograft in terms of functional knee scores, posterior stability, and the graft appearance. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Fifty-eight patients who underwent isolated single-bundle PCL reconstruction using an arthroscopic trans-septal portal with remnant preservation technique were evaluated. They were divided into group A (mixed tendon; n = 30) and group B (Achilles tendon; n = 28). Knee function was evaluated using the Lysholm knee score, Tegner activity score, and the International Knee Documentation Committee (IKDC) grading scale. Anteroposterior stability was measured using the Telos stress view. Twenty patients (66.7%) from group A and 21 patients (75.0%) from group B underwent hardware removal and a second-look arthroscopic examination. RESULTS: The Lysholm knee scores in groups A and B increased from a respective average of 43 and 50 preoperatively to 90 and 88 at follow-up. The IKDC grade and Tegner activity scores were also significantly improved in both groups. Stability was improved in both groups, with an average posterior laxity of 3.0 mm (group A) and 3.3 mm (group B) at follow-up (P > .05). However, there were 4 intraoperative complications in group B: 2 bone fractures and 2 graft pullouts during precyclic tensioning. Second-look arthroscopy revealed a partial tear in 8 cases (40%) from group A and 15 cases (71.4%) from group B (P = .03). All of the partial tears were located in the femoral aperture area. Complete synovial coverage was demonstrated in 10 patients (50%) from group A and 5 patients (23.8%) from group B (P = .04). However, clinical outcomes and stability were not affected by the arthroscopic graft appearance. CONCLUSION: Satisfactory results were obtained for groups A and B in patients who underwent reconstruction for isolated PCL injury. However, 4 intraoperative complications (14.3%) were encountered with use of the Achilles tendon allograft (group B), with a relative higher rate of partial tear and less synovialization in the femoral aperture area.

Arthroscopic direct repair for a complete radial tear of the posterior root of the medial meniscus.

We report here on a new arthroscopic direct repair technique for a radial tear of the posterior root of the medial meniscus (PRMM) using a posterior trans-septal portal. Radial tears of the PRMM are commonly observed in the elderly population of Korea and Japan, and the life style of these people requires squatting and kneeling down in daily life. A radial tear of the PRMM results in the loss of hoop tension and this accelerates degenerative changes in the knee joint and causes early osteoarthritis. Several reports in the medical literature have focused on various repair techniques for these tears by using pull out sutures. These techniques result in nonanatomic fixation of the meniscus, which may lead to disturbed meniscal excursion and failure to restore hoop tension. Arthroscopic direct repair may contribute to restoring hoop tension and preventing accelerated degenerative changes in the knee joint of these patients.