Static Mediolateral Tilt of the Joint Line after Total Knee Arthroplasty Does Not Reflect Dynamic Tilt during a Stair Ascent Activity

Author(s):  
Kazuma Yabu ◽  
Shinichiro Nakamura ◽  
Shinichi Kuriyama ◽  
Kohei Nishitani ◽  
Hiromu Ito ◽  
...  

AbstractThe correlation between static and dynamic mediolateral (ML) tilts of the joint line in the coronal plane remains unknown after total knee arthroplasty (TKA). The purpose was to evaluate the ML tilt as measured by two-dimensional to three-dimensional registration during stair ascent in TKA patients, and to examine the correlation between the dynamic ML tilt and radiographic measurements of static indices. Thirty-two knees that underwent TKA using the mechanical alignment method were included. Continuous sagittal fluoroscopy was taken from before initial contact (IC) until after the toe-off (TO) phase during the stair ascent. The ML tilt of the tibial component relative to the ground was analyzed in terms of dynamic alignment using image-matching techniques, whereas static alignment was measured using standing long-leg radiographs. The correlation between static and dynamic ML tilts was evaluated. In the fluoroscopic analysis, the joint line was neutral (0.0 degree, standard deviation [SD] = 3.4 degrees) around IC phases, then was tilted valgus (5.5° valgus, SD = 2.6 degrees) in the mid-stance (MS) phase. After the TO phase, the joint line became almost neutral (0.4 degrees valgus, SD = 3.1 degrees). The dynamic ML tilt was significantly more varus during the IC phase and significantly more valgus in MS and TO phases than the static ML tilt (1.4 degrees valgus, SD = 2.0 degrees). No correlation was found between static and dynamic ML tilts in weight-bearing phases. During stair ascent, the static tilt had no correlation with the dynamic tilt in weight-bearing phases despite being in the same range. Static lower limb alignment does not reflect coronal alignment during motion. Further research should be conducted to determine whether the horizontal dynamic ML tilt can improve long-term durability and clinical outcomes after TKA.

Author(s):  
Harun R. Gungor ◽  
Nusret Ok

AbstractThere is a tendency of orthopaedic surgeons to elevate joint line (JL) in revision total knee arthroplasty (RTKA). Here, we ascertain the use of the spacer block tool (SBT) to determine JL more accurately for less experienced RTKA surgeons. To perform more precise restoration of JL, an SBT with markers was developed and produced using computer software and three-dimensional printers. The study was planned prospectively to include patients who received either condylar constrained or rotating hinge RTKA between January 2016 and December 2019. To determine JL, distance from fibular head (FH), adductor tubercle (AT), and medial epicondyle (ME) were measured on contralateral knee preoperative radiographs and on operated knee postoperative radiographs. Patients were randomized and grouped according to the technique of JL reconstruction. In Group 1, conventional methods by evaluating aforementioned landmarks and preoperative contralateral knee measurements were used to determine JL, whereas in Group 2, the SBT was used. The main outcome measure was the JL change in revised knee postoperatively in contrast to contralateral knee to compare effective restoration of JL between the groups. Twenty-five patients in Group 1 (3 males, 22 females, 72 years, body mass index [BMI] 32.04 ± 4.45) and 20 patients (7 males, 13 females, 74 years, BMI 30.12 ± 5.02) in Group 2 were included in the study. JL measurements for the whole group were FH-JL = 18.3 ± 3.8 mm, AT-JL = 45.8 ± 4.6 mm, and ME-JL = 27.1 ± 2.8 mm preoperatively, and FH-JL = 20.7 ± 4.2 mm, AT-JL = 43.4 ± 5.2 mm, and ME-JL = 24.7 ± 3.1 mm postoperatively. JL level differences in reference to FH, AT, and ME in Group 1 were 3.6 ± 3.1, 3.6 ± 3.5, and 3.4 ± 3.1 mm, respectively, and in Group 2 were 1.0 ± .0.9, 1.3 ± 1.3, and 1.1 ± 1.3 mm, respectively. There were statistically significant differences between the two groups in JL changes referenced to all of the specific landmarks (p < 0.05). The use of the SBT helped restore JL effectively in our cohort of RTKA patients. Therefore, this tool may become a useful and inexpensive gadget for less experienced and low-volume RTKA surgeons.


2016 ◽  
Vol 10 (1) ◽  
pp. 155-165 ◽  
Author(s):  
Alexandre Renaud ◽  
Alexandre Fuentes ◽  
Nicola Hagemeister ◽  
Martin Lavigne ◽  
Pascal-André Vendittoli

Background:Various implants of total knee arthroplasty (TKA) are used in clinical practice and each presents specific design characteristics. No implant managed this day to reproduce perfectly the biomechanics of the natural knee during gait.Objectives:We therefore asked whether (1) differences in tridimensional (3D) kinematic data during gait could be observed in two different designs of TKA on the same patients, (2) if those gait kinematic data are comparable with those of asymptomatic knees and (3) if difference in clinical subjective scores can be observed between the two TKA designs on the same patient.Methods:We performed knee kinematic analysis on 15 patients (30 TKAs) with two different TKA implant designs (Nexgen, Zimmer and Triathlon, Stryker) on each knee and on 25 asymptomatic subjects (35 knees). Clinical evaluation included range of motion, weight bearing radiographs, questionnaire of joint perception, KOOS, WOMAC and SF-12.Results:Comparison between TKAs and asymptomatic knees revealed that asymptomatic knees had significantly less knee flexion at initial contact (p< 0.04) and more flexion for most of the swing phase (pbetween 0.004 and 0.04). Asymptomatic knees also had less varus at loading response, during stance phase and during most of the swing phase (pbetween 0.001 - 0.05). Transverse plane analysis showed a tendency for asymptomatic knees to be more in internal rotation during stance phase (p0.02 - 0.04). Comparing both TKA designs, NexgenTMimplant had significantly more flexion at the end of swing phase (p= 0.04) compared to knees with the TriathlonTMimplant. In frontal plane, from initial contact to maximum mid stance angle and between the mean mid stance angle and initial contact NexgenTMTKA had significantly more adduction (varus,p=0.02 – 0.03). Clinical scores of both TKAs did not have significant difference.Conclusions:TKA with the tested implants did not reproduce natural knee kinematics during gait. In our cohort of patients, TKA implant design translated in limited kinematics differences during gait and on clinical results.


Author(s):  
LiMing Liu ◽  
Kai Lei ◽  
Xin Chen ◽  
HuaQuan Fan ◽  
Liu Yang ◽  
...  

AbstractRadiographs are widely used to measure distal femoral valgus cut angle (VCA) in total knee arthroplasty (TKA), but its accuracy is controversial. This study used three-dimensional (3D) reconstruction models to verify the accuracy of VCA measurements on radiographs, and explore the correlation of VCA with hip–knee–ankle (HKA) angle and lateral femoral bowing angle (FBA). A total of 444 osteoarthritis knees of 444 patients from August 2016 to June 2018 was included retrospectively. On radiographs, two-dimensional VCA (VCA-2D) was measured between the femoral mechanical axis and the distal femoral anatomical axis, and HKA was measured between the femoral mechanical axis and the tibial mechanical axis. On the coronal projection of computed tomography 3D models, the anatomical landmarks used for VCA-3D measurements were the same as those on the radiographs, FBA was measured between the proximal and distal femoral anatomical axis. The distributions of VCA-2D and VCA-3D were evaluated by means and variances. The correlation between HKA and VCA and between FBA and VCA was explored. There was a statistical difference between VCA-2D and VCA-3D (p < 0.001), but the deviation was very small (0.15 ± 0.69 degrees), 83.3% of the deviations were less than 1 degree. VCA would increase both in 2D and 3D with increasing of FBA and HKA varus. There was no statistically significant difference between VCA-2D and VCA-3D in patients with moderate varus knees (0–8 degrees of varus) and mild bowing femurs (FBA <5 degrees). Overall, the deviation caused by using radiography to measure VCA was negligible. VCA measurements using radiographs were accurate in patients with moderate varus knees and mildly bowed femurs. This study reflects level of evidence III.


Author(s):  
Cole M. Howie ◽  
Simon C. Mears ◽  
C. Lowry Barnes ◽  
Erin M. Mannen ◽  
Jeffrey B. Stambough

AbstractFlexion instability (FI) is one of the leading causes of knee pain and revision surgery. Generally, the biomechanical etiology is considered to be a larger flexion than extension gap. This may be due to mismatch of components sizes to the bone or malalignment. Other factors such as muscle weakness may also play a role, and the diagnosis of FI after total knee arthroplasty (TKA) relies on a combination of patient's complaints during stair descent or walking and physical examination findings. Our study examines the role of implant positioning and sizes in the diagnosis of FI. A retrospective review of 20 subjects without perceived FI and 13 patients diagnosed with FI after TKA was conducted. Knee injury and osteoarthritis outcome scores (KOOS) were documented, and postoperative radiographs were examined. Measurements including included tibial slope, condylar offset, femoral joint line elevation along with surrogate soft-tissue measures for girth and were compared between groups. The FI group was found to have a significantly lower KOOS score compared with the non-FI group (55.6 vs. 73.5; p = 0.009) as well as smaller soft-tissue measurements over the pretubercle region (6.0 mm vs. 10.6 mm; p = 0.007). Tibial slope, condylar offset ratios, and femoral joint line elevation were not significantly different between the FI and non-FI groups. We noted a significant difference in tibial slope in posterior-stabilized implants in subjects with and without FI (6.4° vs. 1.5°; p = 0.003). Radiographic measurements consistent with malalignment were not indicative of FI. X-ray measurements alone are not sufficient to conclude FI as patient symptoms, and clinical examinations remain the key indicators for diagnosis. Radiographic findings may aid in surgeon determination of an underlying cause for an already identified FI situation and help in planning revision surgery.


2021 ◽  
pp. 1-14
Author(s):  
Yuki Takahashi ◽  
Takashi Sato ◽  
Tomoharu Mochizuki ◽  
Satoshi Watanabe ◽  
Osamu Tanifuji ◽  
...  

BACKGROUND: After total knee arthroplasty (TKA), the femur tends to be located posteriorly under weight-bearing (WB) conditions, and a paradoxical femoral anterior motion occurs, leading to joint instability. OBJECTIVE: We aimed to clarify factors which affect the postoperative femoral anteroposterior position relative to the tibia under WB conditions (A-P position) in medial pivot (MP) TKA. METHODS: Among 126 knees (81 women) with primary TKA using MP prosthesis for varus osteoarthritic knees, 70 knees had cruciate-retaining inserts (CR) with the reduced conformity and 56 knees had cruciate-substituting inserts (CS) with the full conformity. Using the three-dimensional (3D) assessment system, the associations between the A-P position and the factors including pre- and postoperative lower extremity alignment, component positions, and posterior femoral condylar offset (PCO), were assessed regarding the type of inserts. RESULTS: Significant correlations were seen between the A-P position and posterior tibial slope (PTS), medial PCO, and lateral PCO. Regarding the difference between the two inserts, the PTS, medial PCO, and lateral PCO significantly correlated with the A-P position in the CR, but only the PTS correlated in the CS. CONCLUSIONS: The increased PTS and decreased PCO were the dominant factors for the A-P position in MP TKA.


Author(s):  
Mehmet Emin Simsek ◽  
Mustafa Akkaya ◽  
Safa Gursoy ◽  
Özgür Kaya ◽  
Murat Bozkurt

AbstractThis study aimed to investigate whether overhang or underhang around the tibial component that occurs during the placement of tibial baseplates was affected by different slope angles of the tibial plateau and determine the changes in the lateral and medial plateau diameters while changing the slope angle in total knee arthroplasty. Three-dimensional tibia models were reconstructed using the computed tomography scans of 120 tibial dry bones. Tibial plateau slope cuts were performed with 9, 7, 5, 3, and 0 degrees of slope angles 2-mm below the subchondral bone in the deepest point of the medial plateau. Total, lateral, and medial tibial plateau areas and overhang/underhang rates were measured at each cut level. Digital implantations of the asymmetric and symmetric tibial baseplates were made on the tibial plateau with each slope angles. Following the implantations, the slope angle that prevents overhang or underhang at the bone border and the slope angle that has more surface area was identified. A significant increase was noted in the total tibial surface area, lateral plateau surface area, and lateral anteroposterior distance, whereas the slope cut angles were changed from 9 to 0 degrees in both gender groups. It was found that the amount of posteromedial underhang and posterolateral overhang increased in both the asymmetric and symmetric tibial baseplates when the slope angle was changed from 0 to 9 degrees. Although the mediolateral diameter did not change after the proximal tibia cuts at different slope angles, the surface area and anteroposterior diameter of the lateral plateau could change, leading to increased lateral plateau area. Although prosthesis designs are highly compatible with the tibial surface area, it should be noted that the component overhangs, especially beyond the posterolateral edge, it can be prevented by changing the slope cut angle in males and females.


The Knee ◽  
2018 ◽  
Vol 25 (6) ◽  
pp. 1262-1271 ◽  
Author(s):  
Monther A. Gharaibeh ◽  
Elizabeth Monk ◽  
Darren B. Chen ◽  
Samuel J. MacDessi

Author(s):  
Kartik M. Varadarajan ◽  
Angela Moynihan ◽  
Darryl D’Lima ◽  
Clifford W. Colwell ◽  
Harry E. Rubash ◽  
...  

Accurate knowledge of in vivo articular contact kinematics and contact forces is required to quantitatively understand factors limiting life of total knee arthroplasty (TKA) implants, such as polyethylene component wear and implant loosening [1]. Determination of in vivo tibiofemoral contact forces has been a challenging issue in biomechanics. Historically, instrumented tibial implants have been used to measure tibiofemoral forces in vitro [2] and computational models involving inverse dynamic optimization have been used to estimate joint forces in vivo [3]. Recently, D’Lima et al. reported the first in vivo measurement of 6DOF tibiofemoral forces via an instrumented implant in a TKA patient [4]. However this technique does not provide a direct estimation of tibiofemoral contact forces in the medial and lateral compartments. Recently, a dual fluoroscopic imaging system has been used to accurately determine tibiofemoral contact locations on the medial and lateral tibial polyethylene surfaces [5]. The objective of this study was to combine the dual fluoroscope technique and the instrumented TKAs to determine the dynamic 3D articular contact kinematics and contact forces on the medial and lateral tibial polyethylene surfaces during functional activities.


Sign in / Sign up

Export Citation Format

Share Document