scholarly journals Changes in Femoral Posterior Condylar Offset, Tibial Posterior Slope Angle, and Joint Line Height after Cruciate-Retaining Total Knee Arthroplasty

2016 ◽  
Vol 28 (1) ◽  
pp. 27-33 ◽  
Author(s):  
Sang Jun Song ◽  
Dae Kyung Bae ◽  
Kang Il Kim ◽  
Ho Yeon Jeong

Introduction: The aim of this work was to compare the posterior tibial slope of the tibial component after performing a total knee arthroplasty, as an intramedullary or extramedullary guide was used during the surgical technique, as well as comparing the range of mobility obtained according to the Instrumentation used. Material and methods: We conducted a descriptive, retrospective, observational study of a series of 57 patients operated in our Center during 2012 and 2013, with the same model of total knee arthroplasty (Sigma PS® DePuy), divided into two homogeneous groups in terms of age, sex, degree of osteoarthritis evolution, the first with patients operated by extramedullary guidance and the second by intramedullary guidance. A radiographic study was performed, measuring the posterior slope angle in the sagittal plane. The range of mobility achieved after arthroplasty and implant survival was studied. Results: Together, in both groups, measurements of the posterior slope angle were made, which was 4.35º preoperative average. In groups, the mean postoperative posterior fall angle was 4.04 ° in the patients who underwent an EM guide, while those who underwent an IM guide the mean was 1.76 °; the differences being statistically significant. The range of mobility in the ATRs operated by intramedullary guidance was 102.7º on average (range 80-125º), while in the group where the extramedullary guide was used, it was 104.3º (range 80-130º) no these differences being statistically significant. Regarding the survival of the implant, during the study period two cases of patients undergoing surgery for the replacement of prostheses were found, both of which belonged to the “Extramedullary guide” group. Conclusion: The posterior drop angle, for the same PS prosthesis model, was statistically different according to the guide used, being within the 3-7º range in the group where the extramedullary guide was used; but despite these differences, no impact on the range of mobility was observed. Currently, it is recommended to restore the patient's posterior tibial slope, and in cases with a slope greater than 10º use a PS ATR.


2018 ◽  
Vol 7 (1) ◽  
pp. 69-78 ◽  
Author(s):  
K-T. Kang ◽  
Y-G. Koh ◽  
J. Son ◽  
O-R. Kwon ◽  
J-S. Lee ◽  
...  

ObjectivesPosterior condylar offset (PCO) and posterior tibial slope (PTS) are critical factors in total knee arthroplasty (TKA). A computational simulation was performed to evaluate the biomechanical effect of PCO and PTS on cruciate retaining TKA.MethodsWe generated a subject-specific computational model followed by the development of ± 1 mm, ± 2 mm and ± 3 mm PCO models in the posterior direction, and -3°, 0°, 3° and 6° PTS models with each of the PCO models. Using a validated finite element (FE) model, we investigated the influence of the changes in PCO and PTS on the contact stress in the patellar button and the forces on the posterior cruciate ligament (PCL), patellar tendon and quadriceps muscles under the deep knee-bend loading conditions.ResultsContact stress on the patellar button increased and decreased as PCO translated to the anterior and posterior directions, respectively. In addition, contact stress on the patellar button decreased as PTS increased. These trends were consistent in the FE models with altered PCO. Higher quadriceps muscle and patellar tendon force are required as PCO translated in the anterior direction with an equivalent flexion angle. However, as PTS increased, quadriceps muscle and patellar tendon force reduced in each PCO condition. The forces exerted on the PCL increased as PCO translated to the posterior direction and decreased as PTS increased.ConclusionThe change in PCO alternatively provided positive and negative biomechanical effects, but it led to a reduction in a negative biomechanical effect as PTS increased. Cite this article: K-T. Kang, Y-G. Koh, J. Son, O-R. Kwon, J-S. Lee, S. K. Kwon. A computational simulation study to determine the biomechanical influence of posterior condylar offset and tibial slope in cruciate retaining total knee arthroplasty. Bone Joint Res 2018;7:69–78. DOI: 10.1302/2046-3758.71.BJR-2017-0143.R1.


2021 ◽  
Vol 87 (3) ◽  
pp. 453-460
Author(s):  
Hany Elbardesy ◽  
André McLeod ◽  
Rehan Gul ◽  
James Harty

The aim of this systematic review was to evaluate the evidence on reservation of Posterior Femoral Condylar Offset (PFCO) and Joint Line (JL) after Revision Total Knee Arthroplasty (RTKA) for im- proved functional outcomes. A comprehensive search of PubMed, Medline, Cochrane, CINAHL, and Embase databases was conducted, with papers published from the inception of the database to October 2020 included. All relevant articles were retrieved, and their bibliographies were hand searched for further references on Posterior condylar offset and revision total knee arthroplasty. The search strategy yielded 28 articles. After duplicate titles were excluded, abstracts and full text were reviewed. Nine studies were assessed for eligibility, four studies were excluded because they did not fully comply with the inclusion criteria. Six articles were finally included in this systematic review. Based on this systematic review restoration of the JL and PFCO in RTKR is associated with a significant improvement in the post-operative range of motion, KSS, OKS, patellar function, and SF-36. Reservation of JL should be a major consideration when undertaking RTKA. Of note, increasing PFCO to balance the flexion gap while maintaining joint line should be well assessed intra-operatively. The upper limit of the PFCO that widely accepted is up to 40 % greater than that of the native knee. 4 mm is the upper limit for JL restoration. Level of evidence III.


Author(s):  
Masanori Tsubosaka ◽  
Tomoyuki Kamenaga ◽  
Yuichi Kuroda ◽  
Koji Takayama ◽  
Shingo Hashimoto ◽  
...  

AbstractSeveral studies have reported better clinical outcomes following kinematically aligned total knee arthroplasty (KA-TKA) than mechanically aligned TKA. Consistent reproduction of a KA-TKA is aided by accurate tibial bone resections using computer navigation systems. This study compares an accelerometer-based portable navigation system with a conventional navigation system on tibial bone resection and clinical outcomes in KA-TKA. This study included 60 knees of patients who underwent primary KA-TKA between May 2015 and September 2017. They were randomly assigned to the OrthoPilot and iASSIST groups. A tibial bone cut was performed with 3 degree varus and 7 degree posterior slope in relation to the mechanical axis in all cases. The tibial component angle (TCA) and posterior slope angle (PSA) were evaluated by postoperative radiography, and those that deviated more than 2 degree were set as outliers. The clinical outcomes were the knee range of motion (ROM) and 2011 Knee Society Score (KSS) evaluated at 1 year postoperation. The groups were compared in terms of the TCA, PSA, number of outliers, ROM, and 2011 KSS (p < 0.05). No significant difference was observed between the groups in terms of the mean TCA, PSA, number of outliers, ROM, and categories of the 2011 KSS (objective knee indicators, symptoms, satisfaction, expectations, and functional activities). Although tibial bone cuts were performed with 3 degree varus and 7 degree posterior slope, no significant difference was observed between the OrthoPilot and iASSIST groups in terms of the accuracy of cuts or postoperative clinical result. The iASSIST was found to be a simple and useful navigation system for KA-TKA.


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