SagittalMeter Pro vs WhereMyCup

SagittalMeter is an educative app to easily measure sagittal balance parameters, by directly placing your phone on the sagittal X-Rays. The sagittal balance is an imperative factor to take into consideration for all practitioners treating spine problems and particularly for surgeons during the pre-operative phase. The compensatory mechanisms of a sagittal unbalanced spine may prevent a successful surgery outcome. A fundamental understanding of a correct sagittal alignment is strongly recommended in determining the correct use of fusion or non fusion devices. SagittalMeter enables you to measure 3 fundamental angles which are essential to analyze sagittal alignment (for pre, per and post-operative phases): • Pelvic incidence (PI) • Pelvic tilt (PT) • Sacral slope (SS) Values of lumbar lordosis are also important parameters to describe sagittal balance, so with SagittalMeter you can measure both: • L1-S1 lordosis • L4-S1 lordosis You can do a complete sagittal balance analysis by using advanced mode which extends the previous values with the following measures: • Occipito-C2 angle • Spino-sacral angle (SSA), angle between line from C7/T1 center to S1 plateau center and surface of S1 plateau • C7/T1 slope • C7-C2 angle • Spino-cranial angle (CIA), angle between line from C2 Dens to C7/T1 center and surface of C7/T1 endplate What does it mean? If a patient appears to have sagittal imbalance, this needs to be taken into consideration in the pre-operative planning. Any surgical treatment option should aim at the re-establishment of an ‘economic’ posture, achieved with the restoration of the patient specific sagittal balance. Remembering all theoretical normal values is very important but is definitively not easy and can even be impossible. SagittalMeter gives you the possibility to measure all the parameters in a quick way and gives you the average theoretical normal values for an equivalent asymptomatic healthy patient. How much correction do I need to restore a good balance in daily practice? Before any kind of lumbar fusion including the segment L4 to S1 it is mandatory to analyse the spine balance. If the PT or the lumbar lordosis are not correlated with the value of the PI, an approximation of the amount of correction requested can be evaluated with the FBI technique: C7 translation angle + Femur obliquity angle + PT compensation angle. SagittalMeter enables you to evaluate the FBI index value to get an average correction value.

Evaluation of functional spinopelvic imaging in lateral radiographs in sitting and standing positions is of importance, especially in patient before total hip replacement surgery. Patients with concomitant hip and spine pathology undergoing primary total hip were identified as being at high risk for dislocation. Instability-prone patients arhtroplasty (THA) should appropriately assessed for the presence of deformity and abnormal spinopelvic mobility. The preoperative planning for THA should encompass evaluation of functional spinopelvic imaging in lateral radiographs in sitting and standing positions. Before planning cup position the surgeon should taken into account also anterior pelvic plane (APP) the coronal (functional) plane and the anterior pelvic plane tilt APPt or pelvic tilt and abnormal spinopelvic mechanics from standing to sitting. The App is software aimed for orthopaedic surgeons, and allow to: -securely import medical images directly from the camera or stored photos. - mark certain points at the image of X-ray, and calculate at once the anterior pelvic plane tilt (APPt) or pelvic tilt , Pelvic incidence (PI), Sacral slope (SS), Lumbar lordosis (LL), Pelvic incidence Angle (PI) minus Lumbar lordosis Angle (LL)(PI–LL). -to classify the patient into one of four Categories of the Hip-Spine Classification (1A,1B,2A,2B) by integrating spinal alignment (spinal deformity defined at PI-LL mismatch >10 degree(1) -cases are categorised to group-specific recommendations for acetabular cup position respectively thus with minimal measurements will effectively identify the complex “hip-spine” THA patient at high risk for postoperative instability (1). -save the planned images, for later review or consultation.The measured values are exported as txt file, ready to print or to input as cells to excel for research. -in case of wrong selection powerful undo feature is present. -According to measured parameters in standing and sitting lateral x- rays - based n a busy everyday practice, app offers a convenient way to perform radiographic measurements for spine, at the spinopelvic juncture - combing sitting and standing X-Rays, in a blink of an eye in front of your screen. The build in features of the app, allows results to be categorized and may help identify the complex “hip-spine” THA patient at high risk for postoperative instability and helps planning the optimum cup placement. All information received from the software output must be clinically reviewed regarding its plausibility before patient treatment! App indicated for assisting healthcare professionals. Clinical judgment and experience are required to properly use the software.The software is not for primary image interpretation. Please see tutorial videos at the developer’s web site www.orthopractis.com References 1. Luthringer, J.M. Vigdorchik A Preoperative Workup of a "Hip-Spine" Total Hip Arthroplasty Patient: A Simplified Approach to a Complex Problem. J Arthroplasty 2019 Jul;34(7S):S57-S70. 2. Pierrepont J, Hawdon G, Miles BP, et al. Variation in functional pelvic tilt in patients undergoing total hip arthroplasty. Bone Joint J 2017;99-B:184. 3 .Langston J, Pierrepont J, Gu Y, Shimmin A. Risk factors for increased sagittal pelvic motion causing unfavourable orientation of the acetabular component in patients undergoing total hip arthroplasty. Bone Joint J 2018;100-B:845. 4. Vigdorchik JM, Sharma AK, Dennis DA, Walter LR, Pierrepont JW, Shimmin AJ. The majority of total hip arthroplasty patients with a Stiff spine Do not have an Instrumented Fusion. J Arthroplasty 2020;35(6S):S252e4. 5. Esposito CI, Carroll KM, Sculco PK, Padgett DE, Jerabek SA, Mayman DJ. Total hip arthroplasty patients with Fixed spinopelvic Alignment are at higher risk of hip dislocation. J Arthroplasty 2018;33:1449. 6.Buckland AJ, et al. Effects of sagittal spinal Alignment on Postural pelvic mobility in total hip arthroplasty Candidates. J Arthroplasty 2019;34:2663.