Richard Underwood, Ph.D.

Dr. Underwood specializes in the tribological performance of mechanical systems and has worked on tribology and failure analysis projects in the bearing, steel, power distribution, power generation, automotive, and medical device sectors. His areas of expertise include measurement of wear, measurement and analysis of surface topography, wear mechanisms, contact mechanics and failure analysis. He has experience in the area of tribological testing and the design of test apparatus.

Dr. Underwood spent two years as the London Implant Retrieval Centre tribologist and established the protocols for the measurement of wear of explanted metal-on-metal hip components. He has measured the wear and investigated the cause of failure of over 250 explanted (retrieval) hip resurfacings and total hip replacements. He has developed a method for measuring the wear of the taper junctions of modular large head metal-on-metal hips and has investigated the causes of tribocorrosion and wear. His research has focused on the effect of design, manufacturing, lubrication mechanisms, wear mechanisms, and surgical and patient factors on the in-vivo performance of hip systems.

Prior to joining Exponent, Dr. Underwood worked as a researcher at the Tribology Group at Imperial College London. In 2008 he completed a Ph.D. on the effects of lubricant contamination on the performance of rolling element bearings. During his time at the tribology group Dr. Underwood worked on projects investigating failure of high voltage switch equipment, environmental degradation of lubricants, bearing failure in marine water jet propulsion system, and bearing failure in pump equipment on a liquid natural gas carrier. He has measured and analyzed the surface topography for projects as diverse as food technology, gas engine crankshafts, corrosion investigations, and machining trials.

Journal Papers

Underwood RJ, Sayles RS, Bills P, Jiang X, Blunt L, Cann PM. The measurement of wear of LHMoM total hip replacement head neck taper junctions. Tribology International 2011, in press.

Underwood RJ, Zoflagos A , Hart A, Sayles RS, Cann PM. Low clearance increases the risk of edge loading in metal on metal hips. Proceedings, Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, in press.

Bills P, Racasan R, Jiang X, Blunt L, Underwood R, Cann P, Hart A. Assessing the impact of measurement uncertainty in the evaluation of wear of retrieved metal-on-metal hip replacements. Wear 2011. doi:10.1016/j.wear.2011.08.030

Myant C, Underwood RJ, Fan J, Cann PM. Lubrication of metal-on-metal hip joints: The effect of protein content and load on film formation and wear. Journal of the Mechanical Behavior of Biomedical Materials 2011. doi:10.1016/j.jmbbm.2011.09.008

Underwood RJ, Matthies A, Skinner J, Cann P, Hart AJ. A comparison of explanted ASR and BHR hip components: the mechanisms of failure. Journal of Bone and Joint Surgery (British Volume) 2011;93-B: 1169-1177.

Fan J, Myant CW, Underwood RJ, Cann PM, Hart A. Inlet protein aggregation: A new mechanism for lubricating film formation with model synovial fluids. Proceedings, Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine July 2011; 225:696–709.

Hart AJ, Ilo K, Underwood RJ et al. The relationship between the angle of version and rate of wear of retrieved metal-on-metal resurfacings. Journal of Bone and Joint Surgery (British Volume) 2011; 93-B:315–320.

Matthies A, Underwood R, Cann P, Ilo K, Nawaz Z, Skinner J, Hart AJ. A retrieval analysis of 240 metal-on-metal hip components, comparing modular total hip replacement with hip resurfacing. Journal of Bone and Joint Surgery (British Volume) 2011; 93-B:307–314.

Conference Proceedings

Underwood RJ, Sayles RS. Some aspects of the abrasive polishing of metal surfaces. Paper No. A0716.0726. Mechanics and Materials in Design Conference (M2D 2006) Porto, Portugal, July 24–26, 2006.

Underwood RJ, Sayles RS, Kadiric A, Ioannides E. An investigation of the load support of fluid trapped in dents. Paper No I-133. World Tribology Congress, Kyoto, Japan, September 6–11, 2009.

Reddyhoff T, Underwood RJ, Nikas GK, Sayles RS, Spikes HA. Thermal aspects of debris in EHL contacts. Paper No C1-222. World Tribology Congress, Kyoto, Japan, September 6–11, 2009.

Underwood RJ, Cann PM, Ilo K, Wagner CR, Skinner J, Cobb J, Porter M, Muirhead-Allwood S, Hart A. What is the incidence and common characteristics of high wearing explanted metal on metal hips. 2010 British Hip Society Meeting, Sheffield, UK, February 25, 2010.

Underwood RJ, Cann PM, Ilo K, Wagner CR, Skinner J, Hart A. Development of protocol for measuring wear in explanted hip joints using roundness machine 2010 British Hip Society Meeting, Sheffield, UK, February 25, 2010.

Underwood RJ, Cann P M, Hart A, Ilo K, Skinner J, Wagner CR. Development of a protocol for measuring wear in explanted hip joints using roundness machine. Poster No 2322. 2010 ORS (Orthopaedic Research Society) Annual Meeting, New Orleans, LA, March 7–12, 2010.

Underwood RJ, Cann PM, Ilo K, Skinner J, Hart, A. A study of explanted durom metal on metal hips. Poster No 2275. 2010 ORS (Orthopaedic Research Society) Annual Meeting, New Orleans, LA, March 7–12, 2010.

Cann PM, Underwood RJ, Mavraki A, Hart A. A new model for synovial fluid lubrication and wear of artificial joints? 2010 ORS (Orthopaedic Research Society) Annual Meeting, New Orleans, LA, March 7–12, 2010.

Hart A, Ilo K, Underwood RJ, Cann PM, Henckel J, Cobb J, Porter M, Muirhead-Allwood S, Skinner J. Pre-revision CT measured cup angles are related to wear of retrieved metal on metal (MOM) hips Poster No 2495. American Academy of Orthopedic Surgeons (AAOS), March 9–15, 2010.

Hart A, Lloyd G, Sabah S, Sampson B, Underwood RJ, Cann PM, Henckel J, Cobb J, Lewis A, Porter M, Muirhead Allwood S, Skinner J. Why do current generation metal on metal hip arthroplasties fail? British Orthopedic Research Society (BORS), Cardiff, Wales, July 12–13, 2010.

Underwood RJ, Cann PM, Skinner J, Hart A. Does edge loading occur in well positioned cups o f a metal on metal hip arthroplasty. British Orthopaedic Research Society (BORS), Cardiff, Wales, July 12–13, 2010.

Bills P, Underwood RJ, Cann PM, Hart A. What is required to measure the wear of explanted metal on metal hips? British Orthopaedic Research Society (BORS), Cardiff, Wales, July 12–13, 2010.

Underwood RJ, Cann PM, Skinner J, Hart A. Wear analysis of 118 failed current generation MOM hip couples. Paper No. 49. 7th Combined Orthopaedic Research Societies (CORS), Kyoto, Japan, October 16–20, 2010.

Hart A, Underwood RJ, Cann PM, Skinner J. Cause of failure of 118 current generation metal-on-metal (MOM) hip couples. Paper No. 130. 7th Combined Orthopaedic Research Societies (CORS), Kyoto, Japan, October 16–20, 2010.

Underwood RJ, Cann PM, Skinner J, Hart A. The relationship between CT measured component version and wear rate of failed metal on metal hip arthroplasties. Paper 131. 7th Combined Orthopaedic Research Societies (CORS), Kyoto, Japan, October 16–20, 2010.

Hart A, Underwood RJ, Cann PM. Analysis of lesions on 159 MARS MRI scans from patients with metal-on-metal hip replacements. Paper No. 132. 7th Combined Orthopaedic Research Societies (CORS), Kyoto, Japan, October 16–20, 2010.

A Goodship, A Hart, R Underwood. UK Workshop (BORS) on Metal-on-Metal Hip Replacements, 7th Combined Orthopaedic Research Societies (CORS), Kyoto, Japan, October 16–20, 2010.

Underwood RJ, Matthies A, Zografos A, Skinner J, Cann PM, Hart. What are the mechanisms of edge loading in metal-on-metal hips? A study of 400 explanted hip components. Paper No. 0386. 2011 ORS (Orthopaedic Research Society) Annual Meeting, Long Beach, CA, January 13–16, 2011.

Myant C, Fan J, Cann PM, Underwood RJ, Hart A. The influence of model synovial fluid chemistry on the wear of CoCrMo alloy in sliding tests. Poster No. 1108. 2011 ORS (Orthopaedic Research Society) Annual Meeting, Long Beach, CA, January 13–16, 2011.

Hart A, Matthies A, Underwood RJ, Cann P, Ilo K, Zuhair N, Skinner J. Retrieval analysis of 240 metal-on-metal hip components: Comparison between modular total hip replacement and hip resurfacing arthroplasty. Poster No. 120. 2011 ORS (Orthopaedic Research Society) Annual Meeting, Long Beach, CA, January 13–16, 2011.

Underwood, RJ, Matthies A, Zografos A, Cann PM, Skinner J, Hart A. Calculation of the centre of the contact patch to rim distance: The effect of cup position and design on the risk of edge loading in metal-on-metal hips. 2011 ORS (Orthopaedic Research Society) Annual Meeting, Long Beach, CA, January 13–16, 2011.

Underwood RJ, Cann PM, Matthies A, Ilo K, Skinner J, Sayles RS, Hart A. Is “self polishing” in metal-on-metal hips a myth? Poster No. 1213 2011 ORS (Orthopaedic Research Society) Annual Meeting, Long Beach, CA, January 13–16, 2011.

Underwood RJ, Matthies A, Zografos A, Skinner J, Cann PM, Hart A. What are the mechanisms of edge loading in metal-on-metal hips? A study of 400 Explanted Hip Components Poster No. 0386. 2011 ORS (Orthopaedic Research Society) Annual Meeting, Long Beach, CA, January 13–16, 2011.

Hart A, Matthies A, Underwood RJ, Cann PM, Ilo K, Nawaz S, Skinner J, Porter M. Retrieval analysis of 240 metal-on-metal hip components: stemmed versus resurfacing hip arthroplasty. Paper No. 033. American Academy of Orthopaedic Surgeons (AAOS) San Diego, CA, February 15–17, 2011.

Hart A, Underwood RJ, Cann PM, Ilo K, Matthies A, Cobb J, Muirhead-Allwood S, Porter M, Skinner J. Clinical and wear analysis of 276 failed large diameter metal-on-metal components. Paper No. 067. American Academy of Orthopaedic Surgeons (AAOS) San Diego, CA, February 15–17, 2011.

Underwood RJ, Zografos A, Matthies A, Ilo K, Cann PM, Lali F, Skinner J, Hart A. The occurrence of edge loading in metal on metal hips: Low clearance is a new risk factor. Paper No. 068. American Academy of Orthopaedic Surgeons (AAOS) San Diego, CA, February 15–17, 2011.

Underwood R, Zografos A, Hart A, Sayles RS, Cann P. Edge loading in current generation metal-on-metal hips—The risk factors. International Conference on BioTribology, London, England, September 18–21, 2011.

Underwood RJ, Bills P, Sayles R, Cann P, Xiang J, Blunt L. Taper wear in large head metal-on-metal hips. International Conference on BioTribology, London, England, September 18–21, 2011.

Underwood RJ, Decaulaux E, Kadiric A, Sayles RS, Cann PM. Measurement and analysis of surface topography of new and explanted metal on metal hip joints. International Conference on BioTribology, London, England, September 18–21, 2011.

• Associate Member of the Institution of Mechanical Engineers, Membership # 80012952