Cementless fixation in Oxford unicompartmental knee replacement: a multicentre study of 1000 knees.

The Cementless Oxford Unicompartmental Knee Replacement (OUKR) was developed to address problems related to cementation, and has been demonstrated in a randomised study to have similar clinical outcomes with fewer radiolucencies than observed with the cemented device. However, before its widespread use it is necessary to clarify contraindications and assess the complications. This requires a larger study than any previously published. We present a prospective multicentre series of 1000 cementless OUKRs in 881 patients at a minimum follow-up of one year. All patients had radiological assessment aligned to the bone-implant interfaces and clinical scores. Analysis was performed at a mean of 38.2 months (19 to 88) following surgery. A total of 17 patients died (comprising 19 knees (1.9%)), none as a result of surgery; there were no tibial or femoral loosenings. A total of 19 knees (1.9%) had significant implant-related complications or required revision. Implant survival at six years was 97.2%, and there was a partial radiolucency at the bone-implant interface in 72 knees (8.9%), with no complete radiolucencies. There was no significant increase in complication rate compared with cemented fixation (p = 0.87), and no specific contraindications to cementless fixation were identified. Cementless OUKR appears to be safe and reproducible in patients with end-stage anteromedial osteoarthritis of the knee, with radiological evidence of improved fixation compared with previous reports using cemented fixation.

The early radiological results of the uncemented Oxford medial compartment knee replacement.

We carried out a prospective investigation into the radiological outcomes of uncemented Oxford medial compartment unicondylar replacement in 220 consecutive patients (231 knees) performed in a single centre with a minimum two-year follow-up. The functional outcomes using the mean Oxford knee score and the mean high-activity arthroplasty score were significantly improved over the pre-operative scores (p < 0.001). There were 196 patients with a two-year radiological examination performed under fluoroscopic guidance, aiming to provide images acceptable for analysis of the bone-implant interface. Of the six tibial zones examined on each knee on the anteroposterior radiograph, only three had a partial radiolucent line. All were in the medial aspect of the tibial base plate (zone 1) and all measured < 1 mm. All of these patients were asymptomatic. There were no radiolucent lines seen around the femoral component or on the lateral view. There was one revision for loosening at one year due to initial inadequate seating of the tibial component. These results confirm that the early uncemented Oxford medial unicompartmental compartmental knee replacements were reliable and the incidence of radiolucent lines was significantly decreased compared with the reported results of cemented versions of this implant. These independent results confirm those of the designing centre.

Cytotoxic activity of selected West Indian medicinal plants against a human leukaemia cell line.

OBJECTIVE: To assess the cytotoxic activities of crude extracts and solvent fractions of Spermacoce verticillata, Ficus pumila and Flemingia strobilifera against a MT-4 human leukaemia cancer cell line. METHODS: Crude extracts of dried leaves of S verticillata, F pumila and F strobilifera were made by exhaustive methanol extraction, fractions were obtained from sequential extraction of the crude extract using solvents of increasing polarity. Dose responses corresponding to cell survival following 72-hour exposure to the extracts were determined using a leukaemia cancer cell line (MT-4). Cell viability was assessed using the MTT[3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide] assay reading absorbances at 570 nm. Comparisons were made with controls and cell survival, in each sample well, was determined based on the ratio of the absorbance of the sample to the control. RESULTS: Crude extracts of S verticillata, F pumila and F strobilifera displayed cytotoxicity and the IC50 values were 89 microg/ml, 131 microg/ml and 81 microg/ml, respectively. The petroleum ether and chloroform fractions of the crude extracts of S verticillata and F strobilifera showed potent cytotoxic activity but the highest cytotoxic activity was found in the chloroform and butanol fractions of F pumila with IC50 values of 23 microg/ml and 26 microg/ml, respectively. CONCLUSION: The crude extracts of S verticillata, F pumila and F strobilifera were shown to be cytotoxic to the leukaemia cell line, MT-4 and IC50 values were determined. Fractionation of the crude extracts by solvent-solvent extraction enabled determination of the active fractions and their IC50 values. We propose that cytotoxic activity may be due to antioxidant compounds previously isolated from these plants.

Novel bis(monoterpenoid) indole alkaloids from Psychotria bahiensis.

Two new bis(monoterpenoid) indole alkaloid glucosides, bahienoside A (1) and bahienoside B (2), together with five known compounds, 5alpha-carboxystrictosidine, angustine, strictosamide, and (E)- and (Z)-vallesiachotamine, were isolated from the aerial parts of Psychotria bahiensis collected in Trinidad, West Indies. The structures of the compounds were elucidated using 1D and 2D NMR spectral methods, viz., (1)H, (13)C, (13)C DEPT, (1)H-(1)H COSY, HSQC, HMQC, HMBC, and TOCSY aided by IR, UV, and circular dichroism measurements.

Bioactive compounds from local Psychotria plant species

Bioassay-guided fractionation of the methanol extracts of the aerial parts of Psychotria uliginosa Sw yielded four known bioactive compounds: benz[g]isoquinoline-5,10-dione and 1-hydroxy-4,7-megastigmadien-3-one and blumenol A, which are chemically related to S-(+)-dehydrovomifoliol a known inhibitor of the germination of lettuce seeds. Evaluation of the basic components obtained from the methanol extract of the aerial parts of Psychotria bahiensis DC. yielded five bioactive indole monoterpenoid alkaloids which are known to display various levels of antiplasmodial and antitumor activity: 5 alpha-carboxystrictosidine, angustine, strictosamide and (E) and (Z)-vallesiachotamine; and the novel epimers bahienoside A and B which are currently being investigated for biological activity. The structures were determined by means of 1D and 2D NMR techniques

Post-traumatic creatinuria.

The creatinuria after musculoskeletal injuries was studied in 31 patients. In addition to creatine the urinary outputs of creatinine, total nitrogen, and 3-methylhistidine were studied. Plasma creatine, creatinine, and guanidinoacetate concentrations were measured in some patients. In rats the effect of bilateral hind-limb ischemia was observed on the urine outputs of creatine and creatinine, and on the creatine, protein, and DNA contents of the hind limbs and carcass. In man the creatinuria was positively related to the severity of the injury and this relationship was stronger than with the urinary output of either creatinine or total nitrogen. In the rat creatinuria was related to the duration of the limb ischemia. The mechanism of the creatinuria is not known but the experiments on rats showed part of the excess creatine to be derived from the damaged muscle and excreted shortly after the injury, and part from the undamaged muscle of the carcass which provided the delayed excretion. It is suggested that creatinuria could be used as an indicator of the post-traumatic 'flow' phase.

Bioactive compounds from local Psychotria plant species

Bioassay-guided fractionation of the methanol extracts of the aerial parts of Psychotria uliginosa Sw yielded four known bioactive compounds: benz[g]isoquinoline-5,10-dione and 1-hydroxy-4,7-megastigmadien-3-one and blumenol A, which are chemically related to S-(+)-dehydrovomifoliol a known inhibitor of the germination of lettuce seeds. Evaluation of the basic components obtained from the methanol extract of the aerial parts of Psychotria bahiensis DC. yielded five bioactive indole monoterpenoid alkaloids which are known to display various levels of antiplasmodial and antitumor activity: 5 alpha-carboxystrictosidine, angustine, strictosamide and (E) and (Z)-vallesiachotamine; and the novel epimers bahienoside A and B which are currently being investigated for biological activity. The structures were determined by means of 1D and 2D NMR techniques (AU)