Repair of experimentally induced large osteochondral defects in rabbit knee with various concentrations of Escherichia coli-derived recombinant human bone morphogenetic protein-2.

Effective therapies for the regeneration of large osteochondral defects are still lacking; however, various approaches have been used. We evaluated the efficacy of Escherichia coli-derived dimeric recombinant human BMP-2 (E-rhBMP-2) for the repair of large osteochondral defects in a rabbit model. Osteochondral defects made in the femoral patellar groove of the knee were treated by transplanting gelatin sponges onto which no or various doses of E-rhBMP-2 were loaded. The outcomes were compared with those of an untreated control group four, 12 and 24 weeks after transplantation. At early time points, the cartilage tissue was repaired in a dose-dependent manner, and bone repair was accelerated in the defects treated with high doses of E-rhBMP-2. At 24 weeks, the repair of cartilage tissue was better with E-rhBMP-2 treatment, even at low doses, than without E-rhBMP-2 treatment. Our findings suggest that the use of E-rhBMP-2 improves and accelerates the repair of osteochondral defects in a rabbit model.

Highly sensitive ELISA for determining serum keratan sulphate levels in the diagnosis of OA.

OBJECTIVE: There have been a large number of reports on alterations in the serum level of keratan sulphate (KS), a potential marker of articular cartilage degeneration in patients with arthropathy. Such studies have commonly employed ELISA using the anti-KS monoclonal antibody 1/20/5D4 (5D4-ELISA) to determine KS levels. Recently, a highly sensitive KS ELISA (HS-ELISA) kit has been developed, allowing determination of serum KS levels even in small animals, which were formerly undetectable with 5D4-ELISA. However, the effectiveness of this kit in humans has not been demonstrated. The objective of this study was to assess the usefulness of the HS-ELISA for the analysis of human serum samples. METHODS: Serum samples were collected from 28 patients with knee OA and 23 healthy volunteers. KS was determined by 5D4-ELISA and HS-ELISA, and measurements were compared with those obtained by HPLC. KS levels in serum samples with protease pretreatment were also determined by HS-ELISA. RESULTS: KS levels determined by HS-ELISA exhibited a better correlation with those determined by HPLC, and a higher diagnostic sensitivity for OA compared with 5D4-ELISA. Protease pretreatment of serum further improved the correlation between the values obtained by HS-ELISA and HPLC, as well as the diagnostic sensitivity of HS-ELISA for OA. CONCLUSIONS: HS-ELISA proved useful for determining KS level in serum and the diagnosis of OA. Pretreatment of serum samples with a protease further improved the performance of HS-ELISA.

Blocking of tumor necrosis factor activity promotes natural repair of osteochondral defects in rabbit knee.

BACKGROUND AND PURPOSE: Osteochondral defects have a limited capacity for repair. We therefore investigated the effects of tumor necrosis factor (TNF) signal blockade by etanercept (human recombinant soluble TNF receptor) on the repair of osteochondral defects in rabbit knees. MATERIAL AND METHODS: Osteochondral defects (5 mm in diameter) were created in the femoral patellar groove in rabbits. Soon after the procedure, a first subcutaneous injection of etanercept was performed. This single injection or, alternatively, 4 injections in total (twice a week for 2 weeks) were given. Each of these 2 groups was divided further into 3 subgroups: a low-dose group (0.05 microg/kg), an intermediate-dose group (0.4 microg/kg), and a high-dose group (1.6 microg /kg) with 19 rabbits in each. As a control, 19 rabbits were injected with water alone. The rabbits in each subgroup were killed 4 weeks (6 rabbits), 8 weeks (6 rabbits), or 24 weeks (7 rabbits) after surgery and repair was assessed histologically. RESULTS: Histological examination revealed that the natural process of repair of the osteochondral defects was promoted by 4 subcutaneous injections of intermediate-dose etanercept and by 1 or 4 injections of high-dose etanercept at the various time points examined postoperatively (4, 8, and 24 weeks). Western blot showed that rabbit TNFalpha had a high affinity for etanercept. INTERPRETATION: Blocking of TNF by etanercept enabled repair of osteochondral defects in rabbit knee. Anti-TNF therapy could be a strategy for the use of tissue engineering for bone and cartilage repair.

Beneficial storage effects of epigallocatechin-3-o-gallate on the articular cartilage of rabbit osteochondral allografts.

A fresh osteochondral allograft is one of the most effective treatments for cartilage defects of the knee. Despite the clinical success, fresh osteochondral allografts have great limitations in relation to the short storage time that cartilage tissues can be well-preserved. Fresh osteochondral grafts are generally stored in culture medium at 4 degrees C. While the viability of articular cartilage stored in culture medium is significantly diminished within 1 week, appropriate serology testing to minimize the chances for the disease transmission requires a minimum of 2 weeks. (-)-Epigallocatechin-3-O-gallate (EGCG) has differential effects on the proliferation of cancer and normal cells, thus a cytotoxic effect on various cancer cells, but a cytopreservative effect on normal cells. Therefore, a storage solution containing EGCG might extend the storage duration of articular cartilages. Rabbit osteochondral allografts were performed with osteochondral grafts stored at 4 degrees C in culture medium containing EGCG for 2 weeks and then the clinical effects were examined with macroscopic and histological assessment after 4 weeks. The cartilaginous structure of an osteochondral graft stored with EGCG was well-preserved with high cell viability and glycosaminoglycan (GAG) content of the extracellular matrix (ECM). After an osteochondral allograft, the implanted osteochondral grafts stored with EGCG also provided a significantly better retention of the articular cartilage with viability and metabolic activity. These data suggest that EGCG can be an effective storage agent that allows long-term preservation of articular cartilage under cold storage conditions.

Detection of gene expression in synovium of patients with osteoarthritis using a random sequencing method.

BACKGROUND: The etiology of osteoarthritis (OA) is multifactorial and current research attributes it to a complex network of biochemical factors. We attempted to identify important molecules in OA joint destruction. PATIENTS AND METHODS: Synovium was collected from 2 women with hip OA. Total RNA was extracted from the combined synovium. Messenger RNAs (mRNAs) were randomly sequenced for identification with the oligo-capping method. mRNA expression of 9 genes that were found to be frequently expressed was compared in synovium from 7 OA patients and 2 control patients with no signs of arthritis. RESULTS: We sequenced 7,339 mRNAs in total and identified 4,247 different kinds, which were ranked in order of frequency. Fibronectin was the protein most frequently expressed (230/7,339), followed by matrix metalloproteinases (MMPs) 1 and 3. The 9 genes selected were those encoding fibronectin 1, MMP1, MMP3, tissue inhibitor of metalloproteinase 3, apolipoprotein L-I (APOL1), syndecan binding protein, insulin-like growth factor binding protein 5, heat shock protein 90, and a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS5). We investigated expression of these 9 genes in synovium from the 7 individual patients with OA. All 9 genes were expressed in OA and control synovium. Expression of MMP1 mRNA was weak in OA samples, however, while expression of ADAMTS5 and APOL1 mRNAs was weak in the controls and some of the OA samples. INTERPRETATION: ADAMTS5 and APOL1 may have important roles in the mechanism of OA.

Optimal duration of conservative treatment for lumbar disc herniation depending on the type of herniation.

Six hundred and six clinical records of patients who were admitted to the Department of Orthopaedic Surgery, Suwa Red Cross Hospital, Nagano, Japan, due to lumbar disc herniation (LDH) between 1991 and 2002 were reviewed to determine the ideal conservative treatment period in relation to different types of LDH: contained and non-contained. Since 1997, we have prolonged in-hospital conservative treatment over a few weeks, which resulted in a decrease in the number of surgeries for non-contained LDH, especially of surgeries performed within 1 month. The number of surgeries for contained LDH did not decrease. The preoperative period of non-contained LDH was significantly shorter than that of contained LDH. These results indicate that for patients who have non-contained LDH, intensive conservative treatment may avoid a surgical procedure. For those patients who have contained LDH, conservative treatment should not be prolonged. We believe that the optimal duration of intensive conservative therapy should be less than 1 month.

Changes in total alkaline phosphatase level after hip fracture: comparison between femoral neck and trochanter fractures.

BACKGROUND: Biochemical bone metabolic markers are affected by fractures, and total alkaline phosphatase (ALP) is considered one of the bone formation markers. Only a few reports have dealt with changes in bone formation markers during the healing process of bone fragility hip fractures. Despite the difference in the amount of callus formation and bone fusion rate, no significant differences in longitudinal change of total ALP between femoral neck and trochanter fracture have been reported. METHODS: A total of 69 osteoporotic patients with femoral neck or trochanter fracture whose serum concentrations of total ALP were examined at least four times at six periodic examination points (1, 2, 3, 4, 6, and 8 weeks after surgery) and whose state of bone union was obtained within 24 weeks after surgery were selected for this retrospective study. The characteristic longitudinal change of total ALP during the healing process was shown, and the possibility of total ALP as a predictive factor for the state of osteosynthesis of hip fractures is discussed. RESULTS: Changes in the total ALP level according to the healing process were similar for femoral neck and trochanter fractures. The concentration of total ALP rose to a maximum at 3 weeks after surgery and then gradually decreased for both fractures. However, the range of change was significantly greater for trochanter fractures than for femoral neck fractures. For trochanter fractures, total ALP decreased from 3 to 6 weeks after surgery in all but one patient. CONCLUSIONS: Increases in the concentration of total ALP after surgery and the subsequent decreases may reflect the normal healing process. A significant difference in the changes of total ALP after surgery between femoral trochanter and neck fractures was shown. Periodic measurement of total ALP might be useful for obtaining information on the osteosynthesis state.

Urinary excretion of type I collagen cross-linked N-telopeptide and serum bone-specific alkaline phosphatase analysis to determine the correlation of age and back-pain related changes in elderly women.

We evaluated bone turnover using biochemical markers in 273 women over 60 years of age with suspected osteoporosis. Their age range was 60-96 years, with an average of 72.7 years. Patients with disorders that might affect bone metabolism were excluded. Those complaining of back pain within 6 months before or after examination were assigned to the back-pain group. Serum bone-specific alkaline phosphatase (BAP) was measured as a bone formation marker, and the urinary N-terminal telopeptide of type I collagen (NTX) was measured as a bone resorption marker. Both BAP and NTX levels increased in individuals over 60 years of age; moreover, these markers were significantly higher in subjects aged over 80 years. Among elderly patients, both BAP and NTX levels were significantly higher in those with back pain than in those without, and in a similar way were observed to increase in parallel with age from the 60-year point. We found that both NTX and BAP increased with aging, and that the increase in these bone turnover markers was closely related to back pain. We also showed that NTX and BAP levels increased significantly in women over 80 years, and specifically in patients with back pain.

Unusual stress fracture of the femoral neck in a young adult not caused by excessive stress: a case report.

A 30-year-old man complained of a 10-day history of gradual onset of severe left leg pain. He did not have any history of trauma or excessive training. Routine laboratory data showed no abnormal findings. He was able to perform passive motions of the hip joint without pain, but active motion of the left hip joint was impossible due to anterolateral thigh pain. Plain radiographs of the hip showed no abnormal findings. However, bone scintigraphy indicated trace accumulation in the left femoral neck, and T(1)-weighted magnetic resonance imaging showed a linear low signal on the inferomedial aspect of the femoral neck. Bone mineral density of the lumbar spine was 1.053 g/cm(2), which ruled out osteoporosis. The thigh pain was resolved 2 months after onset with conservative treatment, when plain radiographs showed sclerotic change and a reduction in the intensity of the low signal of T(1)-weighted magnetic resonance imaging. Our diagnosis of unusual stress fracture indicates that the possibility of stress fractures without bone fragility should be kept in mind when young adults complain of atypical pain even without evidence of unusual activities.