A Simple Goniometer for Use Intraoperatively in Total Knee Arthroplasty

Abstract

Intraoperative range of motion (ROM) assessment can be challenging during total knee arthroplasty (TKA) surgery. As computer assisted surgery is costly and not readily available to many surgeons, we have developed a simple, cost-effective intraoperative device to precisely measure knee flexion and extension. A simple knee goniometer system was constructed consisting of a digital level mounted to a base that rigidly attaches two standard needles. The needles are pushed through the overlying soft tissue of the distal femur. The device is then applied to the proximal tibia, where an angle measurement of the knee is registered. A validation study for this device was conducted on two pairs of intact cadaveric lower limbs at 0 deg, 10 deg, 15 deg, 20 deg, 25 deg, and 30 deg. Two orthopedic surgeons experienced with the system performed three measurements at each angle. Systematic error, defined as the goniometer reading at 0 deg flexion anatomically as determined by the navigation system, ranged from −9.1 deg to 3.0 deg, consistent for each operator on every case. Measurement error, defined as the variability in repeated, fixed angle measurements made with the goniometer, was 1.5 ± 1.0 deg across all surgeons, cases, and prescribed flexion angles. For both surgeons and all imposed flexion angles, measurement errors were below the 4 deg clinical threshold. The simple knee goniometer system generated accurate, repeatable measures of changes in flexion angle intraoperatively with measurement error comparable to errors obtained using the commercial navigation system (1 deg–2 deg). However, the knee goniometer is less complex, less time intensive, and less costly than currently available computer assistive devices. Taken together, our results are very promising for the continued development of this device.

Intraoperative Angle Measurement of Anatomical Structures: A Systematic Review

“…Of the 32 articles in the study, 15 reported on technology that is non-image-based [ 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 , 98 ] and will be included in this section. The distribution of the included studies based on the surgery target is illustrated in Figure 4 a, while Figure 4 b shows their distribution based on the surgery type.…”

“…Out of those 15 articles, 6 focused on measurements from manual instruments [ 84 , 85 , 86 , 87 , 88 , 89 ], and 9 focused on inertial-based instruments [ 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 , 98 ], encompassing IMU-, accelerometer-, gyroscope-, and magnetometer-based instruments. The results will be presented considering those subgroups and summarized in Table 5 and Table 6 , respectively.…”

“…In 2013, McGann et al [ 86 ] developed and validated an intraoperative device to precisely measure knee flexion and extension. This knee goniometer consisted of a digital level mounted to a base that rigidly attaches two needles to be pushed through the soft tissue.…”

“…The results will be presented considering those subgroups and summarized in Tables 5 and 6, respectively. Vendittoli (2002) [84] Inclinometer with acetabular insertion rods by hand-tightening a single screw Scaled at 2°intervals from 0°to 70°V ertical acetabular positioning during total hip arthroplasty Position precision for the inclinometer is 42.2 ± 3.8°compared with 44.4 ± 11.4°S ykes (2012) [85] The closed-tube inclinometer used with the transverse acetabular ligament Acetabular inclination during total hip arthroplasty in the lateral decubitus position Two trials were performed for three techniques (freehand, mechanical guide and inclinometer): In the first one, the mean errors were: 5.2 ± 4.3°, 3.6 ± 3.9°, 0.5 ± 0.4°In the second they were: 6.2 ± 4.2°, 3.8 ± 3.3°, 0.6 ± 0.5°M cGann (2013) [86] Knee goniometer: digital level mounted to a base attached to two needles Knee flexion and extension during total knee arthroplasty Systematic error ranged from −9.1°to 3°M easurement error was 1.5 ± 1°M eermans (2015) [87] Digital inclinometer Inclination of the acetabular component during total hip arthroplasty Significantly reduced the number of acetabular component inclination outliers compared with freehand positioning Jeong (2020) [88] Ruler with differently colored lines Perioral ruler for routine aesthetic surgery A woman received corner mouth lift where the angle of the corner of the mouth measured from the stomion changed from −6°to 3°C huaychoosakoon (2020) [89] Two coronal K-wires placed at an angle measured using a goniometer Two sagittal K-wires placed parallel to each other to ensure tibial slope is maintained…”

In Vitro Testing and Clinical Handling of a Novel Implant Positioning Technology for Proximal Humeral Plating

“…The Xin1 implant positioning system, as introduced in [ 5 ], uses existing imaging modalities such as a C-arm to guide the surgeon in the 3D anatomical environment, where otherwise experience and strong spatial perception are required. The system was designed with simplistic thinking in mind to augment established workflows and overcome the common shortcomings of surgical navigation systems, such as complexity, setup and takedown efforts as well as high costs [ 7 ]. The Xin1 principle was abstracted and developed into various prototype application modules, as summarized in [ 5 ].…”