scholarly journals A patient-specific 3D model of the knee to compare the femoral rollback before and after total knee arthroplasty (TKA)

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Alexandra Mercader ◽  
Timon Röttinger ◽  
Amir Bigdeli ◽  
Tim C. Lüth ◽  
Heinz Röttinger

Abstract Purpose Total knee arthroplasty (TKA) is nowadays performed as a standard procedure on a large number of patients suffering from arthrosis. Replacing the knee joint causes changes in the geometry and kinematics of the knee, which are unique to each individual. This research focuses on the method to detect these changes after TKA and on the impact on the knee movement. This approach could reduce complications in patients with post-operative pain and reduce the number of revisions. Methods A 3D model of a patient’s knee was made by measuring the movement with a medically certified infrared stereo camera. This measurement was combined with the 3D model of the patient’s bones, previously segmented from the CT scan. This model is printed in 3D, one part being the mechanism that follows the movement of the patient, and the other part being the 3D copy of the femur and tibia bones. The knee replacement operation is performed directly on the model and the resulting rollback is being measured before and after TKA. Results We observe a difference in the rollback before and after TKA on the 3D printed model. The variation in size and shape of the femoral implant compared to the natural femur condyles is one of the reasons for the changes in the rollback effect. The rollback is half as large after the prosthesis insertion, which confirms the fact that the femoral prosthesis geometry influences the knee kinematics. Conclusions In this study, a first 3D model combining the patient-specific kinematic and the geometry of his bones has been constructed. This model allows the surgeon to validate the plan of the operation, but also to understand the problems and consequences generated by the prosthesis insertion. The rollback is one of the most important motion of the knee joint and this behavior could be quantified, providing comparative analysis of the knee joint before and after the operation. As a future study, the model could be used to analyse more parameters of the TKA such as the impact of different implantation methods.

2020 ◽  
pp. 1-9
Author(s):  
Jereme B. Outerleys ◽  
Michael J. Dunbar ◽  
Glen Richardson ◽  
Cheryl L. Hubley-Kozey ◽  
Janie L. Astephen Wilson

Total knee arthroplasty (TKA) surgery improves knee joint kinematics and kinetics during gait for most patients, but a lack of evidence exists for the level and incidence of improvement that is achieved. The objective of this study was to quantify patient-specific improvements in knee biomechanics relative to osteoarthritis (OA) severity levels. Seventy-two patients underwent 3-dimensional (3D) gait analysis before and 1 year after TKA surgery, as well as 72 asymptomatic adults and 72 with moderate knee OA. A combination of principal component analysis and discriminant analyses were used to categorize knee joint biomechanics for patients before and after surgery relative to asymptomatic, moderate, and severe OA. Post-TKA, 63% were categorized with knee biomechanics consistent with moderate OA, 29% with severe OA, and 8% asymptomatic. The magnitude and pattern of the knee adduction moment and angle (frontal plane features) were the most significant contributors in discriminating between pre-TKA and post-TKA knee biomechanics. Standard of care TKA improves knee biomechanics during gait to levels most consistent with moderate knee OA and predominately targets frontal plane features. These results provide evidence for the level of improvement in knee biomechanics that can be expected following surgery and highlight the biomechanics most targeted by surgery.


2020 ◽  
Vol 8 (9_suppl7) ◽  
pp. 2325967120S0054
Author(s):  
Wang Yuehui ◽  
Zou Shiping ◽  
Cao Liangliang ◽  
Chen Wenzhong

Introduction: To invest the auxiliary role of Patient specific Instrument(PSI) used as osteotomy guide plate in total knee arthroplasty(TKA) with valgus knee. Hypotheses: PSI osteotomy guide plate is applicable for total knee arthroplasty with valgus knee. Methods: A retrospective analysis was performed on 21 patients with valgus knee, including 5 males and 16 females, who underwent TKA in joint surgery department I of ZhengZhou Orthopaedic Hospital from March 2016 to February 2018. All the operations were performed with the assistance of PSI, and the radiographic and clinical evaluations including femoral tibial joint ectropion angle(FTA) before and after operation, range of motion(ROM) and the Hospital for Special Surgery (HSS) knee score were reviewed, and surgical complications were recorded. Results: All the 21 patients werefollowed up for 10 ˜ 26 months (mean 16 months).All the incisions healed by first intention. The FTA was reduced significantly to 6.3 °±1.2° after operation from 17.6 ° + 5.7 °(P < 0.05), the ROM was improved significantly from preoperative 71.3° ±5.8° to postoperative 102.4°±7.5° (P < 0.05), the HSS score at the last follow-up was improved from 38.2±5.7 to 87.5-3.5(P < 0.05). During the follow-up, no complications such as infection, loosening, sinking and valgus were observed. Conclusion: Providing accurate osteotomy, effective correction of the force line, simple operation and satisfactory clinical effect, the PSI osteotomy guide plate is applicable for total knee arthroplasty with valgus knee.


Background: Osteoarthritis involves degeneration of articular cartilage seen with increasing age. The knee joint, the most common joint that falls prey to attacks of osteoarthritis, has 30% incidence in population above 60 years. Total knee arthroplasty (TKA) is the main surgical option for orthopaedics. Though it corrects the deformity and relieves pain, yet it is not the treatment of choice in younger population. This study aimed to validate the effects of proximal fibular osteotomy (PFO) as a newer technique in managing medial compartment knee osteoarthritis. Methods: The diagnosed patients for medial compartment knee joint osteoarthritis were selected for study from Dr. Ziauddin University hospital of Karachi. Excluded were aged less than 40 years, or with BMI more than 30, and patients with tri-compartmental arthritis. Medial and lateral joint spaces along with Oxford knee score were measured and recorded pre- and post-operatively. Patients underwent PFO after giving written and informed consent. Results: Total number of patients selected was 30 for this study; 21 (70%) females, and 9 (30%) males (mean age 58.8 years). Mean pre-operative measured medial joint space on standard antero-posterior (AP) radiograph was 0.442± 0.04 cm. Mean recorded pre-operative Oxford knee score was 23.87±3.74 mm. Improvement was observed in mean postoperative medial joint space to 0.572± 0 .066 cm and mean post-operative Oxford knee score to 40.2±5.8mm. Conclusion: This study concludes that PFO significantly improves joint function in patients with medial compartment osteoarthritis knee and may delay the need for total knee arthroplasty, if carried out at an appropriate stage. Keywords: Osteotomy; Osteoarthritis; Total Knee Arthroplasty.


2018 ◽  
Vol 32 (10) ◽  
pp. 1020-1023 ◽  
Author(s):  
Masahiro Hasegawa ◽  
Shine Tone ◽  
Yohei Naito ◽  
Hiroki Wakabayashi ◽  
Akihiro Sudo

AbstractThe present study aimed to define the prevalence of pain persisting after total knee arthroplasty (TKA) and determine the impact of neuropathic pain. Knee pain after TKA was evaluated in 154 patients (222 knees with osteoarthritis) using a numerical rating scale (NRS) and followed up for a mean of 4.7 years. The patients were classified according to whether they had no or mild pain (NRS ≤ 3), or moderate-to-severe pain (NRS > 3), and then assigned to groups with nociceptive, unclear, or neuropathic pain based on responses to painDETECT questionnaires. Risk factors for these types of pain were determined. The ratio of patients with moderate-to-severe pain was 28% (62 knees). Thirteen patients (21 knees; 9%) experienced unclear pain. Patients with moderate-to-severe or unclear pain had malalignment and lower Knee Society knee scores. In conclusion, a significant number of patients experienced moderate-to-severe and unclear pain after TKA. Moderate-to-severe pain was associated with unclear pain.


2013 ◽  
Vol 7 (4) ◽  
Author(s):  
Hannah J. Lundberg ◽  
Markus A. Wimmer

The purpose of this work is to describe a computational framework for predicting total knee arthroplasty loads which are necessary for accurate preclinical testing of implant designs. Inputs required include patient knee joint kinematics, and implant type, size, and physiological alignment. Computational models used in the framework include the calculation of knee joint kinematics and kinetics, prediction of the contact path, a model to determine muscle forces, and a force model to obtain parametric solutions for implant forces. The resulting knee implant forces have been validated in two studies, and in both the model accurately predicted differences in knee joint loading. To date, implant contact forces have been predicted for 35 patients with four different implant types. Forces have been calculated for walking, chair, and stair activities.


10.29007/g7l8 ◽  
2020 ◽  
Author(s):  
Jialong Li ◽  
David Liu ◽  
Stephen McMahon ◽  
Jonathan Baré ◽  
Andrew Shimmin ◽  
...  

Correcting the knee joint to accommodate the pre-existing soft tissue structures is a major aim in total knee arthroplasty. 3D-to-2D registration of segmented boney geometry obtained from computer tomography (CT) scans to functionally stressed positions in X-Ray (XR) imaging can be a more accurate method of obtaining the laxity envelop. From which, a more patient specific limit for the correctability of the knee joint can be found. Supine CT scans were segmented, and 3D bone models and anatomical landmarks were registered to 2D functional stressed XR imaging. The functional position of the patient femoral and tibial bone is then used to calculate the varus and valgus extent of the patient’s knee joint laxity. 103 preoperative knees undergoing primary total knee arthroplasty identified from six different surgeons. The range of patients who are correctable back to within 3 degrees when a force is applied is 52%. 65% of patients who were within 3 degrees varus/valgus for tibia varus were correctable, while 41% of patients who were within 3 degrees varus/valgus for femoral valgus were correctable. 26% of patients were correctable when the LDFA is outside the threshold and MPTA is not, while 56% of patients were correctable when the MPTA is outside the threshold and LDFA is not. This study demonstrates the complexity of soft tissue structures of the knee joint. The main finding of this study is that correctability is more sensitive to the proximal tibial than the distal and posterior femoral articulating geometry. A lack of dependency between correctability of the knee joint and anatomical measures specific to flexion of the knee is seen. Careful consideration should be made intraoperatively when balancing the knee joint flexion gaps surrounding the soft tissue structures.


2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Yunfeng Zhang ◽  
Hua Liu

Objective. To explore the safety of total knee arthroplasty (TKA) in the treatment of knee osteoarthritis (KOA) and its impact on patients’ postoperative pain and quality of life. Methods. A total of 60 KOA patients admitted to our hospital from January 2019 to January 2020 were selected as the research objects. The knee joint scores (HSS) before and after TKA were compared, and the patients’ quality of life was evaluated using the Osteoarthritis Index of Western Ontario and McMaster University (WOMAC). At the same time, the number of patients with complications was recorded, and the efficacy of TKA was comprehensively analyzed. Results. The postoperative HSS score was significantly higher than the preoperative score ( P < 0.05 ), the postoperative pain score increased with time, and the pain gradually decreased. The postoperative WOMAC score was significantly lower than the preoperative score ( P < 0.001 ), and the score at 6 months after surgery was significantly lower than that at 3 months after surgery ( P < 0.001 ). There were no complications such as severe prosthesis fracture, secondary sepsis, and patellar tendon rupture, and the total incidence of complications was 11.7%. The effective rate of treatment at 6 months after operation was 98.3%, which was significantly higher than that at 3 months after operation ( P < 0.05 ). Conclusion. Total knee arthroplasty can improve the knee joint function of patients with knee osteoarthritis, with low postoperative pain, low complication rate, and good quality of life for patients. It is worthy of promotion and application.


Sign in / Sign up

Export Citation Format

Share Document