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Orthopedic reconstructive surgery can be physically demanding. The musculoskeletal related demands related to performing shoulder arthroplasty are unknown. This study investigates the prevalence of musculoskeletal injuries associated with performing shoulder arthroplasty. An anonymous online survey based on the validated Nordic Musculoskeletal Questionnaire (NMQ) was distributed to society members of the American Shoulder and Elbow Surgeons. The REDCap based branching chain logic survey consisted of four main sections including: 1) personal demographics, 2) practice demographics, 3) NMQ questionnaire, and 4) effects of injury. A novel addition to the nine-region NMQ survey evaluated these areas for bothersome subclinical symptoms with no formal treatment requirement. Overall, 71% of 87 responding surgeons reported musculoskeletal symptoms related to performing shoulder arthroplasty. Within this group, 72% reported primary subclinical pain and 9% reported secondary exacerbation of a previous injury. Symptomatic regions and diagnoses were most often wrist/hand discomfort (20.7%) due to carpal tunnel syndrome and basilar thumb arthritis. Other associated symptoms included spine discomfort due to degenerative disc disease in the cervical (9.4%) or lumbar (18.4%) regions and elbow pain (6.7%) due to lateral epicondylitis or posterior interosseus nerve entrapment. The most common factors related to symptoms were case volume (24%), patient beach-chair operative positioning (17%), and table height (17%). Twenty-five surgeons required time off for work-related symptoms: 23 required <1 week and two required >1 week. Nine surgeons pursued nonoperative treatment and four surgeons underwent surgical intervention. Among all factors assessed, private practice surgeons reported symptoms significantly less frequently than those at tertiary referral (academic) centers. A high percentage of orthopedic surgeon's experience musculoskeletal symptoms related to shoulder arthroplasty. The three most commons areas of work-related pain in shoulder arthroplasty are wrist/hand discomfort, degenerative changes in the cervical and lumbar areas, and elbow pain. [ABSTRACT FROM AUTHOR]

This paper presents a new method for image-guided surgery called image-enhanced endoscopy. Registered real and virtual endoscopic images (perspective volume renderings generated from the same view as the endoscope camera using a preoperative image) are displayed simultaneously; when combined with the ability to vary tissue transparency in the virtual images, this provides surgeons with the ability to see beyond visible surfaces and, thus, provides additional exposure during surgery. A mount with four photoreflective spheres is rigidly attached to the endoscope and its position and orientation is tracked using an optical position sensor. Generation of virtual images that are accurately registered to the real endoscopic images requires calibration of the tracked endoscope. The calibration process determines intrinsic parameters (that represent the projection of three-dimensional points onto the two-dimensional endoscope camera imaging plane) and extrinsic parameters (that represent the transformation from the coordinate system of the tracker mount attached to the endoscope to the coordinate system of the endoscope camera), and determines radial lens distortion. The calibration routine is fast, automatic, accurate and reliable, and is insensitive to rotational orientation of the endoscope. The routine automatically detects, localizes, and identifies dots in a video image snapshot of the calibration target grid and determines the calibration parameters from the sets of known physical coordinates and localized image coordinates of the target grid dots. Using nonlinear lens-distortion correction, which can be performed at real-time rates (30 frames per second), the mean projection error is less than 0.5 mm at distances up to 25 mm from the endoscope tip, and less than 1.0 mm up to 45 mm. Experimental measurements and point-based registration error theory show that the tracking error is about 0.5-0.7 mm at the tip of the endoscope and less than 0.9 mm for all points in the field of view of the endoscope camera at a distance of up to 65 mm from the tip. It is probable that much of the projection error is due to endoscope tracking error rather than calibration error. Two examples of clinical applications are presented to illustrate the usefulness of image-enhanced endoscopy. This method is a useful addition to conventional image-guidance systems, which generally show only the position of the tip (and sometimes the orientation) of a surgical instrument or probe on reformatted image slices. Index Terms--Camera calibration, image-guided surgery, lens-distortion correction, minimally invasive therapy, perspective volume rendering, virtual endoscopy.