A key goal of all TKA alignment strategies is to achieve joint balance. This study aims to compare the alignments achieved by preoperatively planning to a novel distracted joint gap protocol to common alignment strategies as well as to the alignment of a healthy non-arthritic population.A retrospective study comprised of 145 knees was performed. A long-leg supine CT scan, weightbearing AP knee X-ray and two distracted knee X-rays (one each in extension and flexion, making use of an ankle weight to open the joint) were taken pre-operatively. This imaging was used to perform segmentation, landmarking and 3D-to-2D registration. The medial and lateral joint gaps were determined in extension and flexion.The mean weightbearing, KA planned and distracted joint planned HKA were 4.7° (±5.9°) varus, 0.3° (±3.2°) varus, and 2.2° (±3.5°) varus. This compares to a healthy adult HKA of 1.3° (±2.3°) varus. A patient level comparison between the planned KA and distracted joint HKA found that the coronal angles of the two alignments are within 3° of each other for 64% patients, within 3-5° for 26% of patients and greater than 5° for the remaining 10% of patients.Of those compared, the planned distracted HKA was the closest to the constitutional varus HKA of a healthy population. Patient level analysis highlighted the fundamental differences between the planned KA and joint distracted alignments. By considering both hard and soft tissue, the planned joint distracted alignment allows for a more holistic foundation for pre-operative surgical planning for a given patient.
{"title":"Population Level Validation of a Novel Joint Distraction Radiology Protocol in Total Knee Arthroplasty Planning","authors":"David W. Liu, Ishaan Jagota, J. Twiggs, B. Miles","doi":"10.29007/xfj7","DOIUrl":"https://doi.org/10.29007/xfj7","url":null,"abstract":"A key goal of all TKA alignment strategies is to achieve joint balance. This study aims to compare the alignments achieved by preoperatively planning to a novel distracted joint gap protocol to common alignment strategies as well as to the alignment of a healthy non-arthritic population.A retrospective study comprised of 145 knees was performed. A long-leg supine CT scan, weightbearing AP knee X-ray and two distracted knee X-rays (one each in extension and flexion, making use of an ankle weight to open the joint) were taken pre-operatively. This imaging was used to perform segmentation, landmarking and 3D-to-2D registration. The medial and lateral joint gaps were determined in extension and flexion.The mean weightbearing, KA planned and distracted joint planned HKA were 4.7° (±5.9°) varus, 0.3° (±3.2°) varus, and 2.2° (±3.5°) varus. This compares to a healthy adult HKA of 1.3° (±2.3°) varus. A patient level comparison between the planned KA and distracted joint HKA found that the coronal angles of the two alignments are within 3° of each other for 64% patients, within 3-5° for 26% of patients and greater than 5° for the remaining 10% of patients.Of those compared, the planned distracted HKA was the closest to the constitutional varus HKA of a healthy population. Patient level analysis highlighted the fundamental differences between the planned KA and joint distracted alignments. By considering both hard and soft tissue, the planned joint distracted alignment allows for a more holistic foundation for pre-operative surgical planning for a given patient.","PeriodicalId":385854,"journal":{"name":"EPiC Series in Health Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127544370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yves Vanderschelden, A. Grassi, S. Bignozzi, Irene Asmonti, S. Zaffagnini
A procedure with subvastus lateral approach has been utilized routinely on 60 patients, navigation was used due to the reduced exposure of this technique. Purpose of this study was to evaluate pain, function, and implant kinematics at early follow up of this surgical technique.Tibial and femoral implant planning was based on ligament balance, gaps, and intraoperative kinematics. This approach, on pain and function, was verified at early follow- up. KSS and pain score were obtained at pre-op, 1, 3, 12 months. Data were analyzed with ANOVA for KSS and Chi-square for Pain.No intraoperative complications were registered, no patellar tendon lesion or avulsion was noted. Preoperative average leg alignment was 4±6° varus (range 16; -14), corrected to 0° (range 2; -1). Kinematic analysis showed rollback on lateral compartment, while on medial compartment rollback was lower or negligible until 70° of flexion. Less than 5% had a “Fair” or “Poor” KSS score after 3 months. Preop pain was: 41% severe; 50% moderate; 8% mild and 0% none. At 1 month pain was: 2% severe; 18% moderate; 55% mild and 25% none. After 3 months 50% of patients had mild and 50% had no pain. This data was maintained after 1 year, with 31% of patients with mild and 69% of patients no pain (p<0.05).This approach produced promising early outcomes in terms of pain, ROM and knee function, with less than 5% of patients presenting sub-optimal clinical results at 3- months. On symmetrical implant, medial pivot behavior was observed. Medial ligamental envelope preservation and navigated ligament balancing allow to optimize the medial stability and minimize the post-operative pain.
{"title":"Kinematics and Early Clinical Outcomes of Navigated Total Knee Arthroplasty through a Lateral Subvastus Approach","authors":"Yves Vanderschelden, A. Grassi, S. Bignozzi, Irene Asmonti, S. Zaffagnini","doi":"10.29007/qpnp","DOIUrl":"https://doi.org/10.29007/qpnp","url":null,"abstract":"A procedure with subvastus lateral approach has been utilized routinely on 60 patients, navigation was used due to the reduced exposure of this technique. Purpose of this study was to evaluate pain, function, and implant kinematics at early follow up of this surgical technique.Tibial and femoral implant planning was based on ligament balance, gaps, and intraoperative kinematics. This approach, on pain and function, was verified at early follow- up. KSS and pain score were obtained at pre-op, 1, 3, 12 months. Data were analyzed with ANOVA for KSS and Chi-square for Pain.No intraoperative complications were registered, no patellar tendon lesion or avulsion was noted. Preoperative average leg alignment was 4±6° varus (range 16; -14), corrected to 0° (range 2; -1). Kinematic analysis showed rollback on lateral compartment, while on medial compartment rollback was lower or negligible until 70° of flexion. Less than 5% had a “Fair” or “Poor” KSS score after 3 months. Preop pain was: 41% severe; 50% moderate; 8% mild and 0% none. At 1 month pain was: 2% severe; 18% moderate; 55% mild and 25% none. After 3 months 50% of patients had mild and 50% had no pain. This data was maintained after 1 year, with 31% of patients with mild and 69% of patients no pain (p<0.05).This approach produced promising early outcomes in terms of pain, ROM and knee function, with less than 5% of patients presenting sub-optimal clinical results at 3- months. On symmetrical implant, medial pivot behavior was observed. Medial ligamental envelope preservation and navigated ligament balancing allow to optimize the medial stability and minimize the post-operative pain.","PeriodicalId":385854,"journal":{"name":"EPiC Series in Health Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130154715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}