Denm014 Research Methods And Experimental Assessment Answers

The purpose of this assignment is for you to write a critical analysis (review) of three published primary scientific research papers relevant to your MSc programme, but not necessarily related to your project area. Feel free to choose an area that you enjoy or wish to learn more about.

You should include a general background and explain briefly the main achievements (current state of the art) and outstanding issues in the area you choose. You should also include a SWOT analysis involving:

Strengths of each study and the writing of the papers
Weaknesses of the procedures in each study and/or the way data are presented
Opportunities arising from each study for further research
Threats due to other work in the field.

Total hip arthroplasty stand out as the most effective orthopaedic processes. Nonetheless, the hip surgery arena is facing a recurrent challenge of continuous upsurge in the number of patients and cost in addition to controversy about the dependability as well as the performance of implant surfaces (Munir, Walter, and Walsh, 2015). Complete hip arthroplasty is being extensively designated for young individuals and more proactive patients as well as to the expected increasing demand for the process due to the rising life expectancy among patients. Certainly, the outcomes experienced by hip arthroplasty has proved to be successful among grown-up patients. Therefore, with the increase in life expectation in the populace, it is projected that arthroplasty operation is likely to become a normal practice some years to come. In accordance to the contemporary studies by the Brazilian institute for Geography and Statistics (IBGE) the populace of individuals over 60 years will rise by approximately 4% coming 2050.

Indeed, entire hip arthroplasty started in the early 1960s by Charnley a scholar who postulated that the use of a femoral nail with a stainless steel cranium connected with a high-density polyethylene acetabular transplant joined to the bones with the use of polymethylmethacrylate adhesive. Nevertheless, there are numerous challenges which have not be resolved up to date. As a result, there has been need to look for an ultimate mechanical model which has enhanced materials which are resistant to wear and biocompatibility. Accordingly, regardless of the constant research in search of healthier implant resources the most conventional mixture of metal jointed to ultra-high molecular weight polyethylene remain to be the most broadly used. Also, modern materials such as ceramic materials, metal-to-metal alloys among other modern types of polyethylene have been established and polished over the years.

Research papers
1	Munir, S., Walter, W.L. and Walsh, W.R., 2015. Variations in the trunnion surface topography between different commercially available hip replacement stems. Journal of Orthopaedic Research, 33(1), pp.98-105.
2	Pulikottil-Jacob, R., Connock, M., Kandala, N.B., Mistry, H., Grove, A., Freeman, K., Costa, M., Sutcliffe, P. and Clarke, A., 2015. Cost effectiveness of total hip arthroplasty in osteoarthritis: comparison of devices with differing bearing surfaces and modes of fixation. The bone & joint journal, 97(4), pp.449-457.
3	Choudhury, D., Roy, T., Krupka, I., Hartl, M. and Mootanah, R., 2015. Tribological investigation of ultra-high molecular weight polyethylene against advanced ceramic surfaces in total hip joint replacement. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 229(4), pp.410-419.

According to Choudhury et al., (2015) the metal-to-polyethylene surface is still among the commonly used methods in complete hip arthroplasty. The reason for using this method is because it is not costly, it is technically simpler to implant and also allow instant load-bearing. As a result, surgeons have shown a broad experience with this approach. On the same note, the current acetabula which is made of cross-linked polyethylene is expected to improve forthcoming results as experienced with past types of polyethylene. However, this method has its disadvantages such that the used cement weakens with time and then disintegrates. Thus, this is likely to result in cement disease. Therefore, the metal-t-polyethylene surface reveals greater wear unlike it is experienced with the newer surfaces. Furthermore, the particles produced apart from causing polyethylene disease could also cause osteosis.

According to these sources it indicates that ultra-high molecular weight polyethylene is formed through polymerisation of ethylene which is particularly good for orthopaedic implantations. The advantages is that it is biocompatible hence it offers a low friction surface which makes it be resistant to wear.

However, the major challenge of polyethylene is wear which impact on the longevity of prosthesis. Research has shown that young and proactive patients and particularly male patients who are below the age of 55 years are the ones at a greater risk of hastened wear. According to Pulikottil-Jacob et al. (2015) cross-linked polyethylene is attained through the process of irradiating polyethylene using gamma rays. These irradiation of the polyethylene materials generates the cross-bonding in the molecular structure of the material. After that the polyethylene is subjected to heating for a few Celsius just below the melting point, for a specified period so as to exterminate the free radicals. Indeed, the cross-linking of polyethylene which is combined with thermal treatment has come out as the most recent technology for enhancing its resistance against wear. Additionally, this has also improved the oxidation of ultra-high molecular weight polyethylene (UHMWPE) acetabular elements. Certainly, cross-linking is a modern technology since most of the conventional surfaces developed out of UHMWPE have always been sterilised with the use of gamma rays. Therefore, a majority of the acetabular generated from UHMWPE which has been in use for over three decades. Nevertheless, the extent of cross-linking which is only done through gamma sterilisation is not enough as compared to the current irradiation approaches followed by the thermal treatment phase.

According to Munir, Walter, and Walsh, (2015) these scholars argue that the use of metal-to-metal surfaces in entire hip arthroplasty is beneficial as it has the capacity to reduce wear. Accordingly, metal-to-metal joints have minimal wear rates. On the same note, the volumetric rate of wear for metal-to-metal joints has been found to be roughly 200 times lower as compared to that of metal-to-polyethylene joints. To the contrary, regardless of the benefits associated with metal-to-metal joints benefits it has various flaws. Some of these flaws include the high cost, absence of long-lasting clinical trials, patient hypersensitivity to the metal and the production of metal ions which has been perceived in urine and blood (Banaszkiewicz, 2014). While there has been abnormal levels of metal ions being observed in association with metal-to-polyethylene joints, however, these variations are extremely low. Therefore, even though there has been a rise in the number of research in relation to metal-to-metal joints research has shown that there are possible serious effects with the entire hip arthroplasty method. Accordingly, the most common problem being the biological response of lymphocytes and macrophages which are as a result of poor positioning of the implants. As a result, this leads to heightened wear and the release of metal ions.

Brock et al., 2015: The article shows that the taper wear at the head-neck joints has the possibility of causing early failure in large head metal-to-metal hip substitutions.

Tan et al., (2015): This sources is well structure in the sense that it illustrates the procedure used in conducted the research on the way on how to find out how taper design influence fretting and corrosion at the head trunnion surface.

Pulikottil-Jacob et al., 2015: This source gives a clear description regarding the approaches used for fixing of hybrid entire hip arthroplasty in hospitals for special surgery. The sources indicates that the novel which does not have a cemented acetabular elements has fewer screw holes which has enhanced its locking mechanism and reduced the thickness as well as shell-inner conformity.

Weaknesses

González Della Valle et al., 2016: This article shows that even though a majority of the total hip arthroplasty design which has been developed are cost effective, they undergo increased wear. As a result, this has led to the release of metal ions.

Whittaker et al., 2017: This article does not explains how the loss of materials from the head-stem taper joints of the total hip arthroplasty happens and how it can be prevented.

Opportunities

Triantafyllopoulos et al., 2015: This article help by revealing the risk factors for surgical infections following total hip arthroplasty. According to this article it is important to acknowledge patients who are at risk of such complications.

Threats

Park et al., 2016: Most of the modern research are mostly likely to copy the research of the past which is only hip implants in a hip reproduction rig.

Choudhury et al., 2015: This journal comprise of general subject matters which have been research and discovered already, thus it is only affecting the originality of the research topic.

Conclusion

In conclusion, it is beyond doubt that the chief aspect that face total hip arthroplasty is the challenge of wear. Based on the above it shows that the most suitable total hip arthroplasty is that of metal-to-metal method since it has the least wear effect. Therefore, according to this research studies is that joint surfaces are supposed to be made from materials which have high resistance, resistant to corrosion, low wear as well as low friction.

Bibliography

Banaszkiewicz, P.A., 2014. “Modes of failure” of cemented stem-type femoral components: a radiographic analysis of loosening. In Classic Papers in Orthopaedics (pp. 35-38). Springer, London.

Brock TM, Sidaginamale R, Rushton S, Nargol AV, Bowsher JG, Savisaar C, Joyce TJ, Deehan DJ, Lord JK, Langton DJ. Shorter, rough trunnion surfaces are associated with higher taper wear rates than longer, smooth trunnion surfaces in a contemporary large head metal?on?metal total hip arthroplasty system. Journal of Orthopaedic Research. 2015 Dec; 33 (12):1868-74.

Choudhury, D., Roy, T., Krupka, I., Hartl, M. and Mootanah, R., 2015. Tribological investigation of ultra-high molecular weight polyethylene against advanced ceramic surfaces in total hip joint replacement. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 229(4), pp.410-419.

González Della Valle, A., Sharrock, N., Barlow, M., Caceres, L., Go, G. and Salvati, E.A., 2016. The modern, hybrid total hip arthroplasty for primary osteoarthritis at the Hospital for Special Surgery. The bone & joint journal, 98(1_Supple_A), pp.54-59.

Munir, S., Walter, W.L. and Walsh, W.R., 2015. Variations in the trunnion surface topography between different commercially available hip replacement stems. Journal of Orthopaedic Research, 33(1), pp.98-105.

Park, I., Koehle, M. and Deveza, L.R., Howmedica Osteonics Corp, 2016. Total hip replacement surgical guide tool. U.S. Patent 9,408,618.

Pulikottil-Jacob, R., Connock, M., Kandala, N.B., Mistry, H., Grove, A., Freeman, K., Costa, M., Sutcliffe, P. and Clarke, A., 2015. Cost effectiveness of total hip arthroplasty in osteoarthritis: comparison of devices with differing bearing surfaces and modes of fixation. The bone & joint journal, 97(4), pp.449-457.

Sidaginamale, R.P., Joyce, T.J., Bowsher, J.G., Lord, J.K., Avery, P.J., Natu, S., Nargol, A.V.F. and Langton, D.J., 2016. The clinical implications of metal debris release from the taper junctions and bearing surfaces of metal-on-metal hip arthroplasty: joint fluid and blood metal ion concentrations. The bone & joint journal, 98(7), pp.925-933.

Tan, S.C., Teeter, M.G., Del Balso, C., Howard, J.L. and Lanting, B.A., 2015. Effect of taper design on trunnionosis in metal on polyethylene total hip arthroplasty. The Journal of arthroplasty, 30(7), pp.1269-1272.

Triantafyllopoulos, G., Stundner, O., Memtsoudis, S. and Poultsides, L.A., 2015. Patient, surgery, and hospital related risk factors for surgical site infections following total hip arthroplasty. The Scientific World Journal, 2015.

Whittaker RK, Hothi HS, Eskelinen A, Blunn GW, Skinner JA, Hart AJ. Variation in taper surface roughness for a single design effects the wear rate in total hip arthroplasty. Journal of Orthopaedic Research. 2017 Aug;35 (8):1784-92.