Reliability of the posterior condylar offset

Author(s):  
Vicente J. León‐Muñoz ◽  
Andrea Parrinello ◽  
Gianluca Galloni ◽  
Alonso J. Lisón‐Almagro ◽  
Mirian López‐López ◽  
...  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Liangxiao Bao ◽  
Shengwei Rong ◽  
Zhanjun Shi ◽  
Jian Wang ◽  
Yang Zhang

Abstract Background Femoral posterior condylar offset (PCO) and posterior tibial slope (PTS) are important for postoperative range of motion after total knee arthroplasty (TKA). However, normative data of PCO and PTS and the correlation between them among healthy populations remain to be elucidated. The purpose of this study was to determine PCO and PTS in normal knees, and to identify the correlation between them. Methods Eighty healthy volunteers were recruited. CT scans were performed followed by three-dimensional reconstruction. PCO and PTS were measured and analyzed, as well as the correlation between them. Results PTS averaged 6.78° and 6.11°, on the medial and lateral side respectively (P = 0.002). Medial PCO was greater than lateral (29.2 vs. 23.8 mm, P <  0.001). Both medial and lateral PCO of male were larger than female. On the contrary, male medial PTS was smaller than female, while there was no significant difference of lateral PTS between genders. There was an inverse correlation between medial PCO and PTS, but not lateral. Conclusions Significant differences exhibited between medial and lateral compartments, genders, and among individuals. An inverse correlation exists between PCO and PTS in the medial compartment. These results improve our understanding of the morphology and biomechanics of normal knees, and subsequently for optimising prosthetic design and surgical techniques.


2017 ◽  
Vol 31 (08) ◽  
pp. 754-760 ◽  
Author(s):  
Ryan Degen ◽  
Jacob Matz ◽  
Matthew Teeter ◽  
Brent Lanting ◽  
James Howard ◽  
...  

AbstractTotal knee arthroplasty (TKA) is an effective, durable treatment for knee osteoarthritis. However, a subset of patients experiences incomplete pain relief and ongoing dysfunction. Posterior condylar offset (PCO) has previously been shown to be associated with postoperative range of motion (ROM) following TKA; however, an association with patient-reported outcome measures (PROMs) has not been established. The purpose of this study was to evaluate the association between PCO and postoperative ROM and PROMs. A retrospective review of 970 posterior-stabilized single design TKAs was performed. Preoperative and postoperative radiographs were analyzed to measure the change in PCO and anteroposterior (AP) femoral dimension. Clinical outcome measures, including Short Form-12 physical and mental component summaries, Western Ontario and McMaster Universities Arthritis Index, and Knee Society Score were reviewed to determine if these were influenced by changes in PCO and AP dimension. PCO was increased by more than 3 mm in 15.1%, maintained (within 3 mm) in 59.6%, and decreased by more than 3 mm in 25.3% of patients. Comparing between these groups, there were no significant differences in postoperative ROM or PROM. AP dimension increased in 24.4%, maintained in 47.8%, and decreased in 27.8%. Similarly, there were no significant differences in ROM or PROM between these groups. Spearman's correlation analyses failed to identify an association between PCO and ROM or PROMs. In conclusion, increasing or decreasing PCO or AP femoral dimension with this PS TKA design did not significantly affect postoperative ROM or PROM. Similarly, maintenance of PCO within one implant size with this system compared with optimal sizing had no deleterious effect on TKA outcomes.


2015 ◽  
Vol 4 (4) ◽  
pp. 15-21
Author(s):  
Sae Kwang Kwon ◽  
Nimesh Prakash Jain ◽  
Jong Yeal Kang ◽  
Yeon Gwi Kang ◽  
Tae Kyun Kim

Background: Infection complicates traditional joint reconstruction prostheses in up to 7% of cases, witBackground: Alteration in femoral posterior condylar offset (PCO) after total knee arthroplasty (TKA) has been reported to influence maximal flexion angle after TKA. However, there are contradictory reports about its influence on clinical outcome, and the effects of PCO alterations may vary with implant type.Question / purposes: The purpose of this study was to determine whether PCO alterations affect maximal flexion after TKA and other functional outcomes, and whether the effects of PCO alterations differ by implant type.Patients and Methods: Fifty consecutive cases of TKAs in each of four implant types, namely, fixed bearing (FB) cruciate retaining (CR) or posterior stabilized (PS), mobile bearing (MB) CR or PS were included in the study. Patients were evaluated for maximal flexion and clinical outcome scales. The PCO alteration was measured using pre- and postoperative true lateral knee radiographs. Correlations between PCO alterations and functional outcomes including maximal flexion were compared among the four implant types. Results: No significant correlation was found between PCO alterations and maximal flexion achieved in any of the four implant groups (Correlation Coefficient [CC]=-0.03, 0.14, -0.14, 0.04; p> 0.05). The mean maximal postoperative flexion was greater in PS implants than in CR implants (p <0.05). In MB-CR implanted knees, a greater PCO alteration was correlated with worse anterior knee pain score as measured by the PF scoring system (CC=-0.44, p=0.003) and worse WOMAC pain score (CC=-0.41, p=0.007). Conclusions: Our findings indicate that PCO alterations have no effect on maximal postoperative flexion after TKA regardless of the implant type. Whether the implant is of PS or CR type is a better predictor of the final flexion achieved. However, increased PCO is correlated with worse pain score in MB-CR implants. Level of Evidence: Level III, Retrospective comparative study


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.


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