Comparison of patient reported outcomes after Triathlon? and Kinemax Plus prostheses

INTRODUCTION

The Triathlon^® (Stryker, Kalamazoo, MI, US) total knee replacement was designed to improve patient function and survivorship. The aim of this study was to determine whether the Triathlon^® prosthesis produces better patient reported outcomes than a previous design by the same manufacturer, the Kinemax Plus.

METHODS

The outcome of 233 knees of patients with a mean age of 68 years (range: 40–80 years) who received the Kinemax Plus prosthesis were compared with the outcomes of 220 knees of patients with a mean age of 70 years (range: 42–90 years) who received the Triathlon^® prosthesis. Data were collected via postal questionnaire prior to surgery as well as at 8–12 weeks and at 1 year following surgery. Validated questionnaires were used including the WOMAC^® (Western Ontario and McMaster Universities) pain and function scales, the Knee injury and Osteoarthritis Outcome Score quality of life scale and the self-administered patient satisfaction scale.

RESULTS

This study found that patients who had the Triathlon^® prosthesis had significantly better pain relief (p<0.0001), function (p=0.028), knee related quality of life (p<0.0001) and satisfaction (p=0.0003) at three months after surgery than those who received the Kinemax Plus prosthesis. In addition, knee related quality of life (p=0.002) and satisfaction (p=0.021) were significantly higher at one year after surgery in Triathlon^® patients.

CONCLUSIONS

The findings suggest that return to function and reduction in pain may occur more quickly in patients with a Triathlon^® prosthesis than in those with the Kinemax Plus.     

Hormone replacement therapy is associated with improved arterial physiology in healthy post-menopausal women

OBJECTIVE Oestrogen replacement therapy is associated with a marked reduction in coronary event rates in post-menopausal women. As older age is associated with progressive arterial endothelial damage, a key event in atherosclerosis, we assessed whether hormone replacement therapy (HRT) with oestrogen alone, or oestrogen and progesterone combined, is associated with improved endothelial function in healthy women after the menopause. DESIGN Using high resolution external vascular ultrasound, brachial artery diameter was measured at rest and in response to reactive hyperaemia, with increased flow causing endothelium-dependent dilatation (flow-mediated dilatation). PATIENTS We investigated 135 healthy women; 40 were pre-menopausal (mean±SD age/26±6 years, group 1), 40 were post-menopausal and had never taken HRT (aged 58±3 years; group 2) and 55 were age-matched post-menopausal women who had taken HRT for >2 years, from within 2 years of the menopause (aged 57±4 years; group 3). In group 3, 40 women were on combined oestrogen and progesterone and 15 on oestrogen-only HRT. RESULTS In group 2, flow-mediated dilatation was significantly reduced compared with group 1 (4.4±3.4 vs 9.6±3.6%, P<0.001), consistent with a decline in arterial endothelial function after the menopause. In group 3, however, flow-mediated dilatation was significantly better than group 2 (6.2±3.3 vs 4.4±3.4%, P=0.01), suggesting a protective effect of HRT. Flow-mediated dilatation was similar in women taking oestrogen alone and in those on combined HRT (5.5±2.8 vs 6.5±3.4%, P=0.40). CONCLUSIONS Long-term HRT is associated with improved arterial endothelial function in healthy post-menopausal women. This benefit was observed in both the combined hormone replacement and unopposed oestrogen therapy groups. This may explain some of the apparent cardioprotective effect of HRT after the menopause.     

Clinical investigation of human alpha interferon in chronic myelogenous leukemia

Fifty-one patients with previously untreated or minimally treated chronic myelogenous leukemia in chronic phase received human alpha interferon 3 to 9 X 10(6) units intramuscularly (IM) daily until complete hematologic remission, then at doses ranging from 3 X 10(6) units every other day to 9 X 10(6) units daily. Forty-one (80%) patients achieved a hematologic response, 36 (71%) of them attaining a complete hematologic remission with normal peripheral WBC and differential counts. Responding patients showed continuous but slow normalization of several other blood and marrow parameters including platelet counts, serum lactic dehydrogenase and B12 levels, and marrow cellularity and maturation index. Suppression of the Philadelphia chromosome on serial cytogenetic studies of marrow metaphases was documented in 20 of the 36 patients who achieved complete hematologic remission (56%; 39% of total group), eight of whom (22%) had a decrease of the Philadelphia chromosome-positive metaphases to less than 35%. These changes were persistent for 6 months or longer in 18 patients, seven of whom had continuous suppression of the Philadelphia chromosome to less than 90% for a median of 30+ months (range 21+ to 39+ months). After a median follow-up period of 37 months, 25 patients remain in continued disease control with interferon therapy. The projected 3-year survival rate is 76%, with a yearly death rate of 6%, 9%, and 9% in the first 3 years. Response, Philadelphia chromosome suppression, and survival were significantly better among patients in the low-risk category compared to intermediate- and high-risk categories, as defined by a multivariate analysis-derived prognostic model. The projected 3- year survival rate was 94% for patients who achieved a complete hematologic remission on interferon therapy and 45% for those who did not. Thirteen patients have developed blastic crisis, six with lymphoid and three with undifferentiated morphology. We conclude that human leukocyte alpha interferon effectively controls chronic myeloid leukemia and allows reappearance of diploid hemopoietic cells in some patients.     

Percutaneous transluminal balloon dilatation of the mitral valve in pregnancy.

Pregnancy can cause life threatening complications in women with mitral stenosis, and there is a substantial risk of fetal death if valvotomy under cardiopulmonary bypass is required. A patient is described in whom pulmonary oedema developed after delivery of her first child by caesarean section 13 months previously. Subsequent cardiac catheterisation showed severe mitral stenosis (valve area 0.96 cm2, valve gradient 12 mm Hg, pulmonary artery pressure 30/16 mm Hg). Before valvotomy could be performed the patient again became pregnant and presented in pulmonary oedema at twenty two weeks' gestation. Medical treatment was unsuccessful and she underwent percutaneous transluminal balloon dilatation of the mitral valve. This increased the valve area to 1.78 cm2 and reduced the transmitral gradient to 6 mm Hg. The procedure was uncomplicated, and she remained symptom free on no medication. She delivered vaginally at 37 weeks' gestation. Percutaneous transluminal balloon dilatation of the mitral valve is a safe and effective alternative to mitral valvotomy in pregnancy.     

A unique pattern of central nervous system leukemia in acute myelomonocytic leukemia associated with inv(16)(p13q22)

Twenty-six patients with inv(16)(p13q22) or del(16)(q22) in association with acute myelomonocytic leukemia (AMML-M4, FAB classification), and abnormal marrow eosinophils have been treated at this institute. Initial bone marrow eosinophilia (greater than or equal to 4%) was observed in 22 of 26 patients (85%), and abnormal eosinophil morphology, characterized by immature cells with some interspersed basophilic granules, was evident in 26 of 26 (100%). Giemsa-banded chromosome analysis performed in all patients revealed 16 cases with inv(16)(p13q22) alone, and ten cases with additional chromosome changes. Twenty-five patients received combination induction chemotherapy, and 23 (92%) achieved complete remission (CR). The median duration of remission was 18 months (range, six to 72 + months), and the median duration of survival was 34 months (range, 0.5 to 133 months). Nine patients (35%) relapsed in the CNS at a median time of 19 months (range, six to 133 months) from first marrow CR. All patients had leptomeningeal disease, and in addition, six of nine (66%) demonstrated two or more enhancing lesions on computed tomography brain scan, consistent with intracerebral myeloblastomas. Review of 384 Giemsa-banded patients with acute myeloid leukemia revealed no other morphologic or cytogenetic subgroup with either an equivalent incidence of CNS leukemia or documented intracerebral myeloblastomas. This series of inv(16)(p13q22)/del(16)(q22) AMML reports a favorable prognosis for such patients and associates a specific clonal cytogenetic subgroup of acute leukemia with a distinct propensity for CNS relapse, manifesting as leptomeningeal disease and intracerebral myeloblastomas.     

Inaccuracies associated with the automated measurement of mean cell hemoglobin concentration in dehydrated cells

Because of discrepancies between electronically and manually measured values of mean cell hemoglobin concentration (MCHC) encountered in studies of pathologic red cells, we studied the effect of cell water content on MCHC measurements by both methods. A series of red cell samples with varying water contents (54%-164% normal) were prepared from normal cells using the antibiotic nystatin. MCHC was then measured, using the microhematocrit centrifuge and three different electronic cell counters in common laboratory use. For MCHC values above 36 g/dl as measured by the spun hematocrit method, all three electronic counters under estimmated the MCHC, with increasing error as the true MCHC increased. For MCHC values below 30 g/dl, the values from two conductivity based instruments agreed with those from the spun hematocrit method, whereas one instrument based on light scattering overestimated the MCHC. These results indicate that inaccuracies in the measured mean cell volume (MCV) of dehydrated or otherwise undeformable cells may lead to spurious values for MCHC when electronic cell counters are used.     

Evaluation of drugs for elimination of leukemic cells from the bone marrow of patients with acute leukemia

Relatively nonmyelotoxic drugs and drug combinations were investigated for their ability to eliminate malignant cells from human bone marrow. In vitro 90% inhibitory concentration (IC90) doses were established on granulocyte macrophage colony-forming units (GM-CFU) in culture of bone marrow by using the GM-CFU assay for the following drugs: 4- hydroperoxycyclophosphamide (4-HC), Adriamycin, L-asparaginase, bleomycin, hydrocortisone, VP-16, spirogermanium, Taxol, and vincristine. The leukemic cell kill efficiency of these drugs at IC90 doses was compared with that of 4-HC on acute lymphoid leukemia (ALL) cell lines by using the limiting-dilution assay. Under these conditions, no single drug was superior to 4-HC. To increase the in vitro effect in leukemic cell kill, combinations of vincristine with hydrocortisone, Adriamycin, VP-16, and 4-HC were investigated. Vincristine at 1 to 5 micrograms/mL increased the marrow cytotoxicity of hydrocortisone, Adriamycin, and VP-16, but it was protective (subadditive) with 4-HC. Vincristine and 4-HC in combination was additive to supraadditive on ALL cell lines, increased the leukemic cell kill by one to two logs above 4-HC alone at IC90 doses (P less than .05), and was not affected by the addition of excess marrow cells. The recommended doses for chemopurging in clinical studies are vincristine, 1 to 5 micrograms/mL, plus 4-HC, 5 micrograms/mL.