The importance of ergonomics in Total Knee Arthroplasty

Message from Antonia Chen, MD   

Brigham and Women’s Hospital - Boston, MA

Stuart Simpson

As orthopaedic surgeons, our most important goal is to take care of our patients, but we also should make sure to take care of ourselves. Orthopaedic surgery is physically and mentally demanding, which can be beneficial from an intellectual perspective but detrimental if we are interested in operating long-term. Approximately 44 to 66% of orthopaedic surgeons have had a work-related injury attributed to poor surgeon posture.1,2 Literature indicates that multiple factors can influence a surgeon’s incidence of injury.3,4 Additionally, hospital staff routinely take on ergonomically challenging tasks which has been shown to decrease longevity of performing in the operating room.3 Thus, it is beneficial to institute measures to lessen the likelihood for injury by improving ergonomics in the operating room and decreasing energy expenditure for surgeons and operating room staff.

Ergonomics is the study of people's efficiency in their working environment. When evaluating the ergonomics of orthopaedic surgery, the cervical spine, lumbar spine and shoulders are the areas of greatest concern.1,2 Motion sensors placed in these locations can indicate whether or not performing surgical procedures, such as total knee arthroplasty (TKA), place great strain by measuring angles, elevation, and electromyography. Workload questionnaires can also assess surgeons’ mental and physical demands when performing surgical procedures.

In one study comparing robotic TKA to TKA performed by conventional manual instrumentation, it was found that a lower volume arthroplasty surgeon had less energy expenditure when using the Mako system compared to high-volume arthroplasty surgeons and to conventional TKA.5 In addition, another study found that one less surgical assistant was needed in the operating room when performing Mako Total Knee procedures. The same study found that occiput angle was less for both attendings and fellows when performing Mako Total Knee surgery compared to conventional TKA.6 Mako Total Knee was also less mentally and physically demanding based on a workload questionnaire.6 Finally, a surgical assistant demonstrated less shoulder movement when performing Mako Total Knee compared to conventional TKA, as there was no placement of jigs, and array placement and bone registration required less shoulder elevation compared to motions performed during conventional TKA.7

As an orthopaedic surgeon interested in a long career, I find it important to perform surgical procedures that are ergonomic that will allow us surgeons to efficiently perform our cases. Evaluation of surgeon energy expenditure, posture and mental demand determined that Mako Total Knee improved the ergonomics of TKA compared to conventional TKA. Shoulder motion was also improved for an orthopaedic surgical assistant. The future lies in surgeon preservation. Utilizing Mako Total Knee may help improve the posture and ergonomics of orthopaedic surgeons and orthopaedic surgical staff.

Dr. Chen’s “Surgeon posture and workload demands during TKA” poster
  1. Alqahtani SM, Alzahrani MM, Tanzer M. Adult reconstructive surgery: a high-risk profession for work-related injuries. J Arthroplasty. 2016 Jun;31(6):1194-1198
  2. Davis WT, Sathiyakumar V, Jahangir AA, Obremskey WT, Sethi MK. Occupational injury among orthopaedic surgeons. J Bone Joint Surg Am. 2013 Aug 7;95(15):e107.
  3. Abdollahzade F, Mohammadi F, Dianat I, Asghari E, Asghari-Jafarabadi M, Sokhanvar Z. Working posture and its predictors in hospital operating room nurses. Health Promot Perspect. 2016 Mar 31;6(1):17-22.
  4. Yu D, Dural C, Morrow MMB, Yang L, Collins JW, Hallbeck S, Kjellman M, Forsman M. Intraoperative workload in robotic surgery assessed by wearable motion tracking sensors and questionnaires. Surg Endosc (2017) 31:877-886.
  5. Blevins, K.M., Danoff, J.R., Goel, R., Foltz, C., Hozack, W.J., Chen, A.F. Energy expenditure during conventional and robotic arm-assisted total knee arthroplasty. ISTA 31st Annual Congress to be held 10-13 October, 2018.
  6. Scholl, L.Y., Hampp, E.L., Alipit, V., Bhave, A., Bhowmik-Stoker, M., Mont, M.A., Chen, A. Does the use of Robotic Technology Improve a Surgeon’s Cervical Ergonomics and their Overall Satisfaction? ISTA 31st Annual Congress to be held 10-13 October, 2018.
  7. Scholl, L.Y., Hampp, E.L., Alipit, V., Bhave, A., Bhowmik-Stoker, M., Mont, M.A., Chen, A. Can Surgical Technology Reduce Surgical Staff Postural Demands during Total Knee Arthroplasty? ISTA 31st Annual Congress to be held 10-13 October, 2018.