The subject of noise in the operating theatre was recognized as early as 1972 and has been compared to noise levels on a busy highway. While noise-induced hearing loss in orthopaedic surgery specifically has been recognized as early as the 1990s, it remains poorly studied. As a result, there has been renewed focus in this occupational hazard. Noise level is typically measured in decibels (dB), whereas noise adjusted for human perception uses A-weighted sound levels and is expressed in dBA. Mean operating theatre noise levels range between 51 and 75 dBA, with peak levels between 80 and 119 dBA. The greatest sources of noise emanate from powered surgical instruments, which can exceed levels as high as 140 dBA. Newer technology, such as robotic-assisted systems, contribute a potential new source of noise. This article is a narrative review of the deleterious effects of prolonged noise exposure, including noise-induced hearing loss in the operating theatre team and the patient, intraoperative miscommunication, and increased cognitive load and stress, all of which impact the surgical team’s overall performance. Interventions to mitigate the effects of noise exposure include the use of quieter surgical equipment, the implementation of sound-absorbing personal protective equipment, or changes in communication protocols. Future research endeavours should use advanced research methods and embrace technological innovations to proactively mitigate the effects of operating theatre noise. Cite this article: Bone Joint J 2024;106-B(10):1039–1043

The October 2024 Research Roundup. 360. looks at: Fracture risk among stroke survivors according to post-stroke disability status and stroke type; Noise-induced hearing loss: should surgeons be wearing ear protection during primary total joint replacement?; Intravenous dexamethasone in hip arthroscopy can enhance recovery; Patient-reported outcomes following periprosthetic joint infection of the hip and knee: a longitudinal, prospective observational study; When should surgery take place after weight loss?; Which type of surgery is the hardest physically and mentally?

Aims. In the UK, the agricultural, military, and construction sectors have stringent rules about the use of hearing protection due to the risk of noise-induced hearing loss. Orthopaedic staff may also be at risk due to the use of power tools. The UK Health and Safety Executive (HSE) have clear standards as to what are deemed acceptable occupational levels of noise on A-weighted and C-weighted scales. The aims of this review were to assess the current evidence on the testing of exposure to noise in orthopaedic operating theatres to see if it exceeds these regulations. Methods. A search of PubMed and EMBASE databases was conducted using PRISMA guidelines. The review was registered prospectively in PROSPERO. Studies which assessed the exposure to noise for orthopaedic staff in operating theatres were included. Data about the exposure to noise were extracted from these studies and compared with the A-weighted and C-weighted acceptable levels described in the HSE regulations. Results. A total of 15 studies were deemed eligible. These included a total of 386 orthopaedic operations and the use of 64 orthopaedic instruments. A total of 294 operations (76%) and 45 instruments (70%) exceeded the regulations on an A-weighted scale, and 22% (10 of 46) of operations exceeded the maximum C-weighted peak acceptable level of noise. Noise-induced hearing loss was reported in 28 of 55 orthopaedic staff members (50.9%). Conclusion. Safe levels of noise can be exceeded in orthopaedic operations, and when using orthopaedic instruments. Employers have clear policies about exposure to noise in the workplace but have yet to identify orthopaedic theatres as a potential at-risk area. Orthopaedic staff need education, monitoring, and protection, while employers should consider regular assessments of staff in orthopaedic theatres and offer methods to prevent noise-induced hearing loss. Cite this article: Bone Joint J 2023;105-B(6):602–609

Introduction. Orthopaedic theatres can be noisy. Noise exposure is known to be related to reduced cognition, reduced manual dexterity and increased rates of post-operative wound infection. Up to 50% of orthopaedic theatre staff have features of Noise-Induced Hearing Loss (NIHL) with higher levels in consultants compared to registrars. Exposure to noise levels of 90dB(A) at work for a career of 40 years, equates to a 51% risk of hearing loss. Materials & methods. A Casella CEL-242 meter was positioned in the corner of the theatre tent. Recordings were taken for 17 Total Knee Replacements (TKRs) and 11 Total Hip Replacements (THRs). This meter recorded the decibel level once per second (whereas EU Regulation requires equivalent continuous level measurement). Results. Noise levels reached 105.6dB(A) using a hammer during a TKR and 97.9dB(A) with an oscillating saw. Decibel levels exceeded 90dB(A) in every operation within the sample. Percentages of readings at 80.0dB(A) or above, per case, were calculated to estimate the proportion of our data above the EU regulation Lower Action Level; the maximum was 12.6% and they appeared to be greater in TKRs. Discussion. The small percentage of values at 80.0dB(A) or above indicates that the equivalent continuous decibel level for an average 8 hour day would be below the EU Lower Action Level. It was expected that TKRs would have higher percentages of decibels at 80.0dB(A) or above, given the greater time spent sawing in this procedure. Exposure to levels above 90dB (which occurred in every case) for short time periods is proven to cause irreversible loss of hearing. Minor damage accumulates throughout a career of 40 years, and can result in NIHL. Conclusion. Tools used in orthopaedic theatre produce impulse noises that can cause NIHL. Average daily exposure can be assumed to be acceptable. Further investigation is required

Surgeons working in orthopaedic operating theatres are exposed to significant noise pollution due to the use of powered instruments. This may carry a risk of noise-induced hearing loss (NIHL). This study was designed to quantify the noise exposure experienced by orthopaedic surgeons and establish whether this breaches occupational health guidelines for workplace noise exposure. A sound dosimeter was worn by the operating surgeon during 3 total hip replacements and 2 total knee replacements. A timed record of the procedures was kept concurrently. Noise levels experienced during each part of the procedure were measured and total noise exposures calculated. Quantified noise exposures were compared with occupational health guidelines. Noise exposure in total hip replacement averaged 4.5% (1.52–6.45%) of the allowed daily dose (average duration 77.28 min). Total knee replacement exposure was 5.74% (4.09–7.39%) of allowed exposure (average duration 69.76min). Maximum sound levels approached, but did not exceed recommended limits of 110 dBA (108.3dBA in total hip replacement and 107.6dBA in total knee replacement). Transient peak sound levels exceeded occupational health maximum limits of 140dB on multiple occasions during surgery. Overall total noise dose during orthopaedic surgery was acceptable, however orthopaedic surgeons experience brief periods of noise exposure in excess of legislated guidelines. This constitutes a noise hazard and carries a significant, but unquantified risk for NIHL

In the light of EEC proposals on the avoidance of damage to hearing caused by noise, a study was undertaken to determine the risk posed by powered orthopaedic instruments. The noise levels from a number of air-powered and electric tools were measured and analysed and found to exceed the recommended levels. The predicted daily personal noise exposure was calculated and the potential for hearing damage confirmed. Twenty-seven senior orthopaedic staff were then assessed by audiometry; evidence of noise-induced hearing loss was found in half the subjects. The increasing use of powered instruments in elective orthopaedics and fracture fixation may present a significant cumulative risk to the hearing of orthopaedic surgeons and theatre personnel. The use of ear defenders should be promoted, and manufacturers should be encouraged to develop instruments with lower noise emission levels