Since the plasma level of MMP-3 in GOA was higher than that in KOA patients, it may be a superior indicator for whole-joint degeneration.

Objective. To determine the content of two crosslinks, pyridinoline (a mature crosslink) and pentosidine (a senescent crosslink), in human articular cartilage, and to examine the effect of bone and joint disorders on the content 9f those crosslinks in articular cartilage.Methods. After pretreatment with SP-Sephadex C-25, high-performance liquid chromatography was conducted on a hydrolysate of human articular cartilage from 53 patients with one of the following diseases: osteoarthritis (OA), rheumatoid arthritis (RA), osteoporosis, femoral head necrosis, and renal osteodystroResults. Pyridinoline levels were either unchanged with age or were slightly decreased in elderly patients. Pentosidine levels increased with age in the entire patient population. There was no significant difference in the pyridinoline content among the study groups, but there was a significant difference in pentosidine content (P < 0.001). ROD patients had the highest mean level of pentosidine (407 pmoleslmole of hydroxyproline), and RA patients had a higher mean P~Y (ROD). Conchsion. Bone and joint disorders do not affect the pyridinoline content in articular cartilage, but they do affect the pentosidine content.Pyridinoline is a trifunctional 3-hydroxypyridinium crosslink of mature collagen that is widely distributed in the connective tissues and is abundant in cartilage and bone (1,2). Pyridinoline is an intra-and inter-molecule crosslink of cartilage collagen fibrils and plays a role in stabilizing the collagen fibril network (3). It is a nonreducible crosslink, and its synthesis increases with collagen maturation. Urinary pyridinoline and its minor analog, deoxypyridinoline (4), have been used as markers of bone metabolism (5). It has also been proposed that these substances might reflect cartilage metabolism (6,7).Pentosidine, a condensation product of arginine, lysine, and ribose, is an end product of advanced glycation. Since it accumulates in human tissues with age, it is regarded as a senescent crosslink (8). It is also formed by sequential glycosylation and oxidation reactions. The accumulation of pentosidine in tissues such as the ocular lens and the skin increases in the presence of diabetic and uremic conditions (9). Plasma (1 0,ll) and urinary (12) levels of pentosidine have also been shown to be elevated under diabetic and uremic conditions.In previous studies characterizing human articular cartilage pentosidine by use of fluorometry and high-performance liquid chromatography (HPLC) of hydrolysates (13), we found that the amount of pentosidine increased exponentially with age. The amount of pyridinoline, however, remained constant with age

Arthroscopic surgery of the posterior compartment of the knee is difficult when only two anterior portals are used for access because of the inaccessibility of the back of the knee. Since its introduction, the posterior transseptal portal has been widely employed to access lesions in the posterior compartment. However, special care should be taken to avoid neurovascular injuries around the posteromedial, posterolateral, and transseptal portals. Most importantly, popliteal vessel injury should be avoided when creating and using the transseptal portal during surgery. Purpose of the present study is to describe how to avoid the neurovascular injuries during establishing the posterior three portals and to introduce our safer technique to create the transseptal portal. To date, we have performed arthroscopic surgeries via the transseptal portal in the posterior compartments of 161 knees and have not encountered nerve or vascular injury. In our procedure, the posterior septum is perforated with a 1.5-3.0-mm Kirschner wire that is protected by a sheath inserted from the posterolateral portal and monitored from the posteromedial portal to avoid popliteal vessel injury.

The aim of this study was to evaluate the changes of biochemical markers during fracture healing in patients with osteoporosis. The study included 26 patients; 9 underwent hip hemiarthroplasty (mean age +/- SD: 71.0 +/- 10.2 years, group EN) for femoral neck fractures. 7 underwent osteosynthesis (75.3 +/- 8.2 years, group OS) for trochanteric fractures, and 10 subjects had spinal compression fractures (68.2 +/- 12.0 years, group CO). No operative procedures were performed in group CO. Urinary pyridinoline (Pyr), deoxypyridinoline (Dpyr) by high performance liquid chromatography (HPLC), Crosslaps by both enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay (RIA) (CTx-ELISA and CTx-RIA) and serum N-terminal mid-fragment osteocalcin (OCN-Mid) by ELISA were analyzed at the time of admission and at weeks 1, 2, 4, 8 and 24 after operation or, in the case of group CO, after admission. As a whole, bone resorption markers started to increase from week 1, with various peak values between weeks 4 and 8 depending upon the particular marker, but returned to the initial vales at week 24. OCN-Mid started to increase from week 8 and remained at elevated levels at week 24. In groups EN and OS, bone resorption markers changed in the same manner as they did as a whole group. OCN-Mid did not change in group EN, although it increased significantly from week 8 in group OS. No biochemical markers changed significantly in group CO. In conclusion, bone resorption was accelerated at an early stage due to acute osteonecrosis or bed rest, followed by bone formation due to callus or mechanical stress later on. As far as bone resorption markers are concerned, 24 weeks are enough to eliminate the effect of fracture.