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Munir Khan

Publications and source records attributed to Munir Khan.

5 recordsLinked to original sources
PubMed2006

Current in vivo wear of metal-on-metal bearings assessed by exercise-related rise in plasma cobalt level.

Baseline metal ion levels are elevated in patients with metal-on-metal (MOM) hip arthroplasty. Interpretation of baseline levels is difficult as measurements are influenced by wear, corrosion, and metal ion release from stored metal in the body. Schmalzried et al. demonstrated that "wear is the function of use, not time." The specific research question we asked was: Does physiological exercise increase the wear of metal-on-metal articulation which can be measured from the plasma metal ion levels? Patients with three different well functioning MOM bearings [two types of resurfacing (BHR 46.8 mm and Cormet 48 mm) and Metasul 28 mm] were included. Blood samples were taken immediately before, immediately after, and 1 h after exercise to determine cobalt and chromium levels. A significant increase (p<0.005) in serum cobalt and chromium of 13% and 11%, respectively, was noticed after the exercise. Rise of cobalt levels in patients with a resurfacing MOM was 8.5 times (BHR group) or 6.5 times (Cormet group) larger than in those with a Metasul MOM (p=0.021 and p=0.047). Neither rise of metal levels nor baseline levels correlated with any other factor (p>0.27). Exercise-related elevations of plasma cobalt level provides information on current in vivo wear production that cannot be inferred from a baseline measurement of cobalt levels. Chromium levels cannot provide reliable information on the in vivo wear of the devices. Diameter was the important feature of the implant in determining exercise-related elevations of plasma cobalt level. Exercise-related elevations of plasma cobalt level is a potential in vivo tool to understand and improve the tribology of metal-metal bearings.

Adult↗
PubMed2005

Complex fractures.

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Clinical Competence↗
PubMed2005

Eponyms: errors in clinical practice and scientific writing.

Eponymous terms are in daily use in medicine. This system of nomenclature which simply commemorates a person is inconvenient, poses difficulties to students and leads to frequent mistakes in scientific writings. Nevertheless it can be helpful in completely describing a multi-symptomatic medical condition or a complex surgical procedure which otherwise would not be neatly encapsulated in a reasonably convenient word or phrase. We used Finkelstein's test as an example to demonstrate that the use of such nomenclature in clinical practice and scientific writing creates inaccuracies. We contacted 62 consultant orthopaedic surgeons and 47 specialist orthopaedic registrars of whom 53 consultant and 39 registrars responded. Three different descriptions of Finkelstein's test were used as described in current literature. Only 10 (10.7%) surgeons recognised the correct method as described by Finkelstein and 83 (89.3%) were unable to do so. The results shows that a statistically significant proportion of surgeons uses the test (p < 0.0001) but fails to identify the correct method (p < 0.0001). We also found that Finkelstein's test was inaccurately described in literature since Leao's incorrect description in 1958 (quoting Eichhoff's manoeuvre) and the mistake persisted for over 50 years before it could be accredited. Such mistakes are frequent not only in hand surgery but in other sections of medicine as well. We conclude that in the modern era of evidence based medicine, use of such trivial nomenclature should be avoided. Efforts should be made to introduce proper descriptive nomenclature, by devising criteria systems which would be easy to use and not fictitious.

Data Collection↗