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1.
Background
This work aimed to evaluate the changes in the femoral posterior condylar offset (PCO) and tibial slope after posterior cruciate ligament (PCL)-substituting total knee arthroplasty (TKA), and to address the presence of any interactive effect between the two on knee flexion.Methods
Fifty-two PCL-substituting TKAs were performed using a posterior referencing system. Three-dimensional reconstructed computed tomographic (CT) images were used to evaluate PCO and tibial slope before and after arthroplasty. Range of motion and clinical scores were evaluated at a mean of 3.1 years postoperatively. Multivariate linear model with interaction terms was used to evaluate and compare the relationships among changes in PCO, tibial slope, and postoperative knee flexion angles.Results
The degree of change in PCO was greater in the lateral condyle than in the medial condyle (3.1 ± 2.5 mm and ? 0.5 ± 2.8 mm, respectively). Postoperative medial and lateral tibial slopes were 1.4° ± 1.8 and 1.4° ± 2.0, respectively. The mean degree of postoperative knee flexion was 125°. Analysis with interaction terms and covariate adjustment demonstrated that medial PCO and tibial slope were significantly related to knee flexion with interactive effect (P = 0.011). In cases with < 3° posterior tibial slope, the postoperative PCO was positively correlated to the degree of knee flexion angle. However, in cases with > 3° tibial slope, PCO was negatively correlated to knee flexion.Conclusion
Medial femoral PCO and tibial slope showed interactive effect on knee flexion after PCL-substituting TKAs. Reconstitution of the proper PCO and avoiding excessive tibial slope may be necessary. 相似文献2.
Background
Malrotation of tibial and femoral components is a potential source of pain following total knee arthroplasty (TKA). This study aimed to 1) compare component rotation in TKA patients with unexplained pain versus a control group with well-functioning TKAs and 2) investigate the relationship between TKA component rotation and pain.Methods
Seventy one patients with unexplained pain after primary TKA were compared to a control cohort of 41 well functioning TKA patients. Both groups underwent post-operative computed tomography (CT) scans to assess component rotation. Findings were compared between the painful and control TKA groups.Results
We found no difference in femoral component rotation between the painful and control groups (mean 0.6° vs 1.0° external rotation (ER), p = 0.4), and no difference in tibial component rotation (mean 11.2° vs 9.5° internal rotation (IR), p = 0.3). Also, there was no difference in combined mal-rotation (tibial + femoral rotation) between the groups (mean 10.5° vs 8.5°IR, p = 0.25). Fifty-nine percent of patients in the painful group had tibial component rotation > 9°IR vs 49% in the control group.Conclusion
In the largest study yet on component rotation after TKA, we found no difference in the incidence of tibial, femoral, or combined component mal-rotation in painful versus well-functioning TKAs. Tibial component IR relative to the junction of the medial to middle thirds of the tibial tubercle appears to be common in patients with well-functioning TKAs. The significance of slight tibial IR should be interpreted with caution when evaluating the painful TKA.Level III retrospective case–control study. 相似文献3.
Kyoung-Tak Kang Sae Kwang Kwon Juhyun Son Oh-Ryong Kwon Jun-Sang Lee Yong-Gon Koh 《The Knee》2018,25(5):903-914
Background
Postoperative changes of the femoral posterior condylar offset (PCO) and posterior tibial slope (PTS) affect the biomechanics of the knee joint after fixed-bearing total knee arthroplasty (TKA). However, the biomechanics of mobile-bearing is not well known. Therefore, the aim of this study was to investigate whether alterations to the PCO and PTS affect the biomechanics for mobile-bearing TKA.Methods
We used a computational model for a knee joint that was validated using in vivo experiment data to evaluate the effects of the PCO and PTS on the tibiofemoral (TF) joint kinematics, patellofemoral (PF) contact stress, collateral ligament force and quadriceps force, for mobile-bearing TKA. The computational model was developed using ± 1-, ± 2- and ± 3-mm PCO models in the posterior direction and ? 3°, 0°, + 3°, and + 6° PTS models based on each of the PCO models.Results
The maximum PF contact stress, collateral ligament force and quadriceps force decreased as the PTS increased. In addition, the maximum PF contact stress and quadriceps force decreased, and the collateral ligament force increased as PCO translated in the posterior direction. This trend is consistent with that observed in any PCO and PTS.Conclusions
Our findings show the various effects of postoperative alterations in the PCO and PTS on the biomechanical results of mobile-bearing TKA. Based on the computational simulation, we suggest that orthopaedic surgeons intraoperatively conserve the patient's own anatomical PCO and PTS in mobile-bearing TKA. 相似文献4.
Yasushi Oshima Norishige Iizawa Tatsunori Kataoka Tokifumi Majima Shinro Takai 《The Knee》2018,25(1):195-202
Background
Femoral rotational alignment is considered an essential factor for total knee arthroplasty because malrotation of femoral components results in poor outcomes. To obtain proper alignment, we developed a superimposable computed tomography (CT) scan-based template to intraoperatively determine the accurate surgical epicondylar axis (SEA), and evaluated the effectiveness of this CT template.Methods
In the experimental group (n = 55), three serial slices of CT images, including medial and lateral epicondyles, were merged into a single image, and SEA was overlaid. SEA was traced onto an image of an assumed distal femoral resection level; this combined image was then printed out onto a transparent film as a CT template. Following a distal femoral resection in TKA, SEA was duplicated onto the femoral surface. Thereafter, the posterior condyle was resected parallel to this SEA. In the control group (n = 53), posterior condyles were resected at three degrees of the external rotation from the posterior condylar line (PCL).A posterior condylar angle (PCA) between PCL of the femoral component and SEA was postoperatively evaluated. Positive values indicated external rotation of the femoral component from the SEA.Results
In the experimental group, PCA was 0.01° ± 1.61°, and three cases were considered as outliers (greater than three degrees or less than ?3 degrees). Conversely, in the control group, PCA was 0.10° ± 2.4°, and 12 cases were considered as outliers. Consequently, dispersion of PCA data was significantly smaller in the experimental group (P = 0.004).Conclusions
The CT template accurately determined intraoperative SEA. 相似文献5.
Richard Niehaus David Schilter Paolo Fornaciari Christian Weinand Marcus Boyd Marcel Ziswiler Stefan Ehrendorfer 《The Knee》2017,24(3):518-524
Background
With the aim of improving component alignment and outcome in total knee arthroplasty (TKA), several computer-assisted devices (CAD) have been developed.Methods
In February 2014, the present unit started to use a new imageless navigation system with accelerometric pods within the surgical field for all primary TKAs; there was no need for optical trackers or cameras. This paper presents the results of the first 72 TKAs using this iAssist system in 71 prospectively collected and retrospectively analyzed patients. It analyzed component positioning in standard and full-length leg x-rays.Results
The mean age of the patients was 70 years (range 52–88). The center of hip, knee and ankle (mechanical axes) deviated on average 0.5° (standard deviation (SD) of 1.8) valgus from the targeted straight alignment. Three TKAs had > 3° deviation (i.e. four degree varus, five degree and seven degree valgus). The frontal tibial tray alignment was an average of 89.9° (range 86.4–100.1°, SD ± 2.0) with the target being 90°, and the sagittal slope was as targeted at 85.0° (range 78.4–88.8°, SD ± 1.7).Conclusions
This CAD facilitated good mechanical alignment and reproducible accuracy in component positioning. Pods clipped onto cutting jigs within the surgical field provided simple and accurate navigation, with little extra time needed for calibration and no need for optical trackers or pre-operative imaging. 相似文献6.
Background
The influence of the surgical approach on the position of the prosthetic components in revision of total knee arthroplasties (rTKA) is still not clear. This study compared the medial parapatellar approach (MPA) and lateral parapatellar subvastus approach with tibial tubercle osteotomy (LPA).Methods
Forty-two consecutive patients underwent rTKA from 2006 to 2016 with either MPA (n = 21) or LPA (n = 21) because of aseptic loosening, infection, malposition or instability (mean follow-up: 41.5 months). Revision TKA component position and leg alignment were assessed on three-dimensional CT (3D-CT) images and compared between groups using a t-test (p < 0.05). Rotation of rTKA components graded into internal, neutral or external rotation and rates of postoperative complications and revisions were compared between groups with a chi2-test (p < 0.05).Results
Group MPA and LPA showed no significant differences with respect to the femoral component (coronal: 0.6° vs 0.9°; sagittal: 7.5° vs 7.7°; transversal: 0.4° vs ? 0.2°), tibial component (coronal: 0.1° vs 0.3°; sagittal: 3.1° vs 1.6°; transversal: 6.9° vs 9.3°) and leg alignment (varus: 0.2° vs 1.1°) (p < 0.05). Group LPA showed a non-significant (p = 0.25) higher incidence of neutrally (28.6% vs 9.5%) and less internally (23.8% vs 38.1%) rotated tibial components. Rates of complication and revisions did not differ significantly.Conclusions
In contrast with primary TKA, the two approaches did not influence postoperative rTKA position. This can be explained with the more extensive approach at rTKA and means that no corrections of the orientation of the components are needed performing either MPA or LPA. 相似文献7.
Background
The purpose of this study was to evaluate the usefulness of three-dimensional (3D) printed models for open wedge high tibial osteotomy (HTO) in porcine bone.Methods
Computed tomography (CT) images were obtained from 10 porcine knees and 3D imaging was planned using the 3D-Slicer program. The osteotomy line was drawn from the three centimeters below the medial tibial plateau to the proximal end of the fibular head. Then the osteotomy gap was opened until the mechanical axis line was 62.5% from the medial border along the width of the tibial plateau, maintaining the posterior tibial slope angle. The wedge-shaped 3D-printed model was designed with the measured angle and osteotomy section and was produced by the 3D printer. The open wedge HTO surgery was reproduced in porcine bone using the 3D-printed model and the osteotomy site was fixed with a plate. Accuracy of osteotomy and posterior tibial slope was evaluated after the osteotomy.Results
The mean mechanical axis line on the tibial plateau was 61.8 ± 1.5% from the medial tibia. There was no statistically significant difference (P = 0.160). The planned and post-osteotomy correction wedge angles were 11.5 ± 3.2° and 11.4 ± 3.3°, and the posterior tibial slope angle was 11.2 ± 2.2° pre-osteotomy and 11.4 ± 2.5° post-osteotomy. There were no significant differences (P = 0.854 and P = 0.429, respectively).Conclusion
This study showed that good results could be obtained in high tibial osteotomy by using 3D printed models of porcine legs. 相似文献8.
Alberto Grassi Cecilia Signorelli Francisco Urrizola Federico Raggi Luca Macchiarola Tommaso Bonanzinga Stefano Zaffagnini 《The Knee》2018,25(4):577-587
Background
Until now, there has been a lack of in vivo analysis of the correlation between bony morphological features and laxity values after an anterior cruciate ligament (ACL) injury.Methods
Forty-two patients who underwent ACL-reconstruction were enrolled. Static laxity was evaluated as: antero-posterior displacement and internal–external rotation at 30° and 90° of flexion (AP30, AP90, IE30, IE90) and varus–valgus rotation at 0° and 30° of flexion (VV0, VV30). The pivot-shift (PS) test defined the dynamic laxity. Using magnetic resonance imaging, we evaluated the transepicondylar distance (TE), the width of the lateral and medial femoral condyles (LFCw and MFCw) and tibial plateau (LTPw and MTPw), the notch width index (NWI) and the ratio of width and height of the femoral notch (N-ratio), the ratio between the height and depth of the lateral and medial femoral condyle (LFC-ratio and MFC-ratio), the lateral and medial posterior tibial slopes (LTPs and MTPs) and the anterior subluxation of the lateral and medial tibial plateau with respect to the femoral condyle (LTPsublx and MTPsublx).Results
Concerning the AP30, LTPs (P = 0.047) and MTPsublx (P = 0.039) were shown to be independent predictors while for the AP90 only LTPs (P = 0.049) was an independent predictor. The LTPs (P = 0.039) was shown to be an independent predictor for IE90 laxity, while for the VV0 test it was identified as the LFCw (P = 0.007).Conclusions
A higher antero-posterior laxity at 30° and 90° of flexion was found in those with a lateral tibial slope < 5.5°. 相似文献9.
Background
In total knee arthroplasty (TKA), femoral component rotation is an important factor in the flexion stability and biomechanics of the patellofemoral joint. However, it remains unclear how much tension is appropriate when performing TKA using the gap technique.Methods
One hundred fifty TKAs that used the gap technique were randomized into one of the three groups. Gravity group (n = 50) included patients who underwent TKA using only the weight of the patient's lower leg. In 20-lbf group (n = 50) and 30-lbf group (n = 50), a gap-tensioning device was set at 20 lbf and 30 lbf respectively. The femoral component rotation was measured based on the clinical transepicondylar axis (cTEA) on postoperative CT and any outliers (a femoral component rotation diverging from the cTEA over 3°) were evaluated.Results
The mean femoral component rotation was ? 0.82° ± 2.44° (95% confidence interval [CI], ? 1.52° to ? 0.13°) in gravity group, ? 0.40° ± 2.22° (95% CI, ? 1.03° to 0.23°) in 20-lbf group, and 1.37° ± 2.70° (95% CI, 0.61° to 2.14°) in 30-lbf group. The mean femoral component rotation in 30-lbf group was significantly different from that in gravity group (p < 0.001) and 20-lbf group (p < 0.001). There were more outliers in 30-lbf group (18% in gravity group, 18% in 20-lbf group, and 36% in 30-lbf group; p = 0.043).Conclusions
The use of a tensioning device set at 30 lbf resulted in an externally rotated femoral component and frequent outliers. 相似文献10.
Background
The purpose of this study was to investigate the ankle center position as determined from the malleoli for total knee arthroplasty (TKA).Methods
We retrospectively analyzed computed tomography data from 102 patients with osteoarthritic knees. The tibial anteroposterior (AP) axis and transmalleolar axis (TMA) were used as rotational reference axes of the knee and ankle joint, respectively. With these axes, we regarded the offset distance from the intermalleolar midpoint as the position of the ankle center and investigated any angular osteotomy errors on the proximal tibia when the ankle center was assumed to the intermalleolar midpoint.Results
The mean offset distances relative to the tibial AP axis were 1.8 ± 0.9 mm medial and 4.2 ± 1.2 mm anterior, and the distances relative to the TMA were 3.0 ± 0.9 and 3.6 ± 1.1 mm in the coronal and sagittal planes, respectively. Mean angular osteotomy errors were 0.3 ± 0.2° in the coronal plane and 0.8 ± 0.2° in the sagittal plane.Conclusions
The ankle center was located around the intermalleolar midpoint. The position of the ankle center observed along the knee reference axis further approached the intermalleolar midpoint than when observed along the ankle reference axis in the coronal plane, but not in the sagittal plane. And the coronal angular osteotomy error was smaller than the sagittal error. Therefore, the intermalleolar midpoint in the coronal plane is a reliable landmark for the ankle center during TKA. However, surgeons should be cognizant of this sagittal angular error. 相似文献11.
Rhodri Williams Amal Thomas Stefan Bajada Tony Antonios Rhidian Morgan-Jones Jelena Bekvalac Philip Adds 《The Knee》2018,25(3):453-458
Background
This large osteology study examined the reliability, reproducibility and correlation between previously described tibial tray rotation alignment lines (including Akagi and Dalury lines). In addition, it described a novel inter-eminence line utilising the tibial plateau inter-condylar eminences as a landmark.Methods
A total of 214 post-medieval (18–19th centuries) skeletal tibia were examined. The inter/intra-observer variation and correlation between reference lines were measured.Results
Inter-observer reproducibility was excellent and there were no differences between Akagi, Dalury, and inter-eminence lines. Similarly, intra-observer reliability was excellent for Akagi, Dalury, and inter-eminence lines. Qualitative review of tibial inter-condylar eminences suggested that these could be easily identifiable. When taking the medial angle from a medial–lateral reference line, the Akagi line showed a mean of 96.90° (± 10.27), inter-eminence line 94.52° (± 12.84), and Dalury line 88.06° (± 11.75). The angle produced by the Dalury line was significantly different from both the Akagi and inter-eminence lines (P ≤ 0.001). The Akagi line and inter-eminence line showed a strong correlation (r = 0.74). The Dalury line showed a weaker correlation with both the Akagi line (r = 0.69) and inter-eminence line (r = 0.40).Conclusion
This study suggested that tibial rotation lines showed excellent intra/inter-observer reliability and reproducibility. The novel and easily drawn inter-eminence line showed strong correlation with the Akagi line and could be used for tibial tray rotational alignment in total knee arthroplasty. 相似文献12.
Yasushi Akamatsu Satoshi Ohno Hideo Kobayashi Yoshihiro Kusayama Ken Kumagai Tomoyuki Saito 《The Knee》2017,24(1):70-75
Background
The coronal subluxation of the proximal tibia relative to the distal femur is a common radiological finding in patients with knee osteoarthritis. The purpose was to evaluate whether the coronal subluxation was corrected after opening wedge high tibial osteotomy (OWHTO), and whether this subluxation was one cause of inconsistency between the actual and predicted alignments (correction loss).Methods
Fifty-one patients (55 knees) were treated with OWHTO. The change of location between the intersection points of the femoral and tibial axes on the tibial plateau (subluxation-C), the change of location between the lines through the most lateral points of the lateral femoral and tibial condyles (subluxation-L), and joint space angle (JSA) were compared in standing knee radiographs before and one year after OWHTO. The subluxation-C and subluxation-L were converted to a percentage of the tibial plateau width.Results
The mean subluxation-C of 6.5% before OWHTO significantly increased to a mean subluxation-C of 7.3% one year after OWHTO. The mean subluxation-L of 6.3% and JSA of 4.5° before OWHTO significantly decreased to a subluxation-L of 1.8% and JSA of 3.3° one year after OWHTO. The change in subluxation-L correlated with the change in femorotibial angle and correction loss (r = 0.634, P < 0.001 and r = 0.463, P < 0.001, respectively).Conclusion
The proximal tibia shifted medially relative to the distal femur after OWHTO. This medial shift correlated with the correction loss. The coronal subluxation might be one cause of correction loss. 相似文献13.
J. Ryan Martin Keith A. Fehring Chad D. Watts Daniel L. Levy Bryan D. Springer Raymond H. Kim 《The Knee》2017,24(4):863-868
Background
Semi-constrained, or varus–valgus constrained, implants are occasionally necessary to achieve stability in primary total knee arthroplasty (TKA). However, outcomes with these implants are largely unknown. Therefore, the primary goals of this study were to determine 1) can we identify preoperatively which patients might require a semi-constrained implant and 2) are there any clinical and or radiographic differences for those that require a semi-constrained implant?Methods
A multicenter retrospective study was performed to retrospectively review patients that had a Stryker Triathlon (Kalamazoo, MI) TKA with a Total Stabilized (TS) tibial insert (n = 75). This TS cohort was subsequently matched 1:1 based on age, gender, and BMI to a cohort of patients with the same primary TKA design with a PS insert (n = 75). Preoperative and postoperative radiographic and clinical data were compared between the two groups.Results
Preoperatively, the TS cohort had significantly greater varus (9.72 vs. 3.48; p = 0.0001) and valgus (14.1 vs. 7.57; p = 0.0001) deformity. Post-operatively, there were no statistically significant differences in revisions (p = 1), reoperations (p = 1), or complications (p = 1). Mean clinical and radiographic follow-ups were equivalent between groups (25.5 vs. 25.8 months, p = 0.8851).Conclusion
As suspected, use of a semi-constrained insert to achieve intraoperative coronal stability was most predicted by preoperative coronal deformity (either varus or valgus). Longer follow-up and larger patient cohorts are necessary to determine. 相似文献14.
Youngjun Kim Byung Hoon Lee Kinde Mekuria Hyunchul Cho Sehyung Park Joon Ho Wang Deukhee Lee 《The Knee》2017,24(2):329-339
Background
Recently, surgical navigation systems have been widely used to improve the results of various orthopaedic surgeries. However, surgical navigation has not been successful in anterior cruciate ligament reconstruction, owing to its inaccuracy and inconvenience. This study investigated the registration of preoperative and intraoperative data, which are the key components in improving accuracy of the navigation system.Methods
An accurate registration method was proposed using new optical tracking markers and landmark retake. A surgical planning and navigation system for anterior cruciate ligament reconstruction was developed and implemented. The accuracy of the proposed system has been evaluated using phantoms and eight cadaveric knees. The present study investigated only the registration accuracy excluding the errors of optical tracking hardware and surgeon.Results
The target registration errors of femoral tunnelling for anterior cruciate ligament reconstruction in phantoms were found to be 0.24 ± 0.03 mm and 0.19 ± 0.10° for the tunnel entry position and tunnel direction, respectively. The target registration errors measured using cadavers were 0.9 mm and 1.94°, respectively.Conclusions
The preclinical experimental results showed that the proposed methods enhanced the registration accuracy of the developed system. As the system becomes more accurate, surgeons could more precisely position and orient the femoral and tibial tunnels to their original anatomical locations. 相似文献15.
《The Knee》2020,27(2):477-484
BackgroundThe position of the femoral component can influence knee kinematics by altering the posterior (PCO) and anterior condylar offset (ACO). The primary aim of this study was to assess whether the length of the cemented stem influences the sagittal position of the femoral component after revision total knee arthroplasty (rTKA). The secondary aim was to determine the influence of the sagittal position on PCO and ACO.MethodsThere were 172 consecutive patients over a seven-year period that underwent rTKA with a cemented semi-constrained prosthesis. The 172 patients were separated into two groups: 115 with short stems (50 mm) and 57 with longer stems (100 or 150 mm). Using rotationally acceptable lateral radiographs, the degree of flexion(+)/extension(−) of the femoral components, PCO, and ACO were measured.ResultsThere was no significant difference (p > 0.25) between the two groups for sagittal position, PCO, or ACO. The average flexion of the femoral component with short stems was 2.2 ± 4.1° and 2.2 ± 3.4° for long stems (difference = 0.0, 95% confidence intervals (CI) − 1.3 to 1.2). The average PCO ratio was 1.02 ± 0.15 for short stems and 0.99 ± 0.17 for long stems (difference = 0.03, 95% CI − 0.02 to 0.08). The average ACO ratio was at 0.07 ± 0.08 for short stems and 0.08 ± 0.08 for long stems (difference = 0.01, 95% CI − 0.01 to 0.04). There was a significant correlation between sagittal alignment of the femoral component and PCO (flexion increased PCO, r = 0.39, p < 0.0001) and ACO (flexion decreased ACO, r = − 0.34, p < 0.0001).ConclusionsCemented stem length does not influence the position of femoral component in the sagittal axis, PCO, or ACO. Surgical technique and sizing of the femoral component may be more predictive. 相似文献
16.
Background
In current practice, anterior cruciate ligament (ACL) tears can be diagnosed using several devices to measure anterior tibial translation and rotational knee laxity, but these measures are never collected together. The Rotab®, which yields simultaneous measurements of anterior tibial translation and passive lower limb rotation under stress, would therefore be advantageous in current practice, but its reliability has never been tested.Aim of study
To evaluate the accuracy and reliability of the Rotab® compared to the reference system, radiostereometric analysis (RSA).Methods
This anatomical study was conducted on 14 lower limbs collected from fresh cadavers. Simultaneous measurements of anterior tibial translation and rotation were obtained with both systems, with antero-posterior (AP) forces of 134 N and 250 N using the Rotab®. Measurements were made on intact ACL and then repeated after ACL section. Variables were analyzed in univariate analysis by ANOVA, and the intraclass correlation coefficient (ICC) between the systems was determined by the Bland and Altman method.Results
The difference between the two methods for evaluating anterior tibial translation was 0.05 ± 0.98 mm at 134 N and 0.29 ± 1.04 mm at 250 N. The correlation between the tests was high (r134 = r250 = 0.97, p = 0.8). The difference between the two methods for rotational laxity was 0.69 ± 2.7° at 134 N and 0.5 ± 0.6° at 250 N. The Rotab® showed a significant difference only at 250 N for rotational laxity after the ACL tear.Conclusion
The Rotab® is a reliable device to measure rotational laxity coupled with anterior translation of the knee. 相似文献17.
Background
Medial meniscus posterior root tear (MMPRT) has been reported to play a key role in the development of spontaneous osteonecrosis of the knee (SONK) and osteoarthritis (OA) of the knee. However, little is known about the differences in the development of SONK and OA after MMPRT. The purpose of this study was to investigate the factors contributing to the development of these conditions.Methods
We evaluated the existence of MMPRT and the extent of medial meniscal extrusion in preoperative magnetic resonance images and proximal tibial morphology in radiographs of 45 patients with SONK and 104 patients with OA who underwent knee surgery.Results
There were no significant differences in age, gender, height, weight, and body mass index between the two groups. The incidence of MMPRT and the mean posterior tibial slope (PTS) were significantly higher in SONK than in OA patients (62.2% versus 34.3%, P = 0.002, and 12.8° versus 10.5°, P < 0.001, respectively). The mean extent of meniscal extrusion was larger in OA than in SONK patients (7.5 mm versus 5.3 mm, P < 0.001). The mean tibial varus angle was 4.8° in SONK and 5.4° in OA, with no significant difference between the two (P = 0.088). Multivariable logistic regression analysis showed that compared with OA, SONK was more closely associated with the existence of MMPRT and had a smaller extent of medial meniscus extrusion and higher PTS.Conclusion
MMRPT and higher PTS were more closely associated with the development of SONK than with that of OA. 相似文献18.
Farhad Iranpour Azhar M Merican Seow Hui Teo Justin P Cobb Andrew A Amis 《The Knee》2017,24(3):555-563
Background
Patellofemoral instability is a major cause of anterior knee pain. The aim of this study was to examine how the medial and lateral stability of the patellofemoral joint in the normal knee changes with knee flexion and measure its relationship to differences in femoral trochlear geometry.Methods
Twelve fresh-frozen cadaveric knees were used. Five components of the quadriceps and the iliotibial band were loaded physiologically with 175 N and 30 N, respectively. The force required to displace the patella 10 mm laterally and medially at 0°, 20°, 30°, 60° and 90° knee flexion was measured. Patellofemoral contact points at these knee flexion angles were marked. The trochlea cartilage geometry at these flexion angles was visualized by Computed Tomography imaging of the femora in air with no overlying tissue. The sulcus, medial and lateral facet angles were measured. The facet angles were measured relative to the posterior condylar datum.Results
The lateral facet slope decreased progressively with flexion from 23° ± 3° (mean ± S.D.) at 0° to 17 ± 5° at 90°. While the medial facet angle increased progressively from 8° ± 8° to 36° ± 9° between 0° and 90°. Patellar lateral stability varied from 96 ± 22 N at 0°, to 77 ± 23 N at 20°, then to 101 ± 27 N at 90° knee flexion. Medial stability varied from 74 ± 20 N at 0° to 170 ± 21 N at 90°. There were significant correlations between the sulcus angle and the medial facet angle with medial stability (r = 0.78, p < 0.0001).Conclusions
These results provide objective evidence relating the changes of femoral profile geometry with knee flexion to patellofemoral stability. 相似文献19.
Takaaki Ohmori Tamon Kabata Yoshitomo Kajino Tadashi Taga Daisuke Inoue Takashi Yamamoto Tomoharu Takagi Junya Yoshitani Takuro Ueno Hiroyuki Tsuchiya 《The Knee》2018,25(1):15-24
Background
The “grand-piano sign” is a well-known indicator of proper rotational femoral alignment. We investigated changes in the shape of the femoral anterior cutting plane by changing the rotational alignment, anterior portion depth, and cutting plane flexion angle.Methods
We simulated various cutting planes after cutting the anterior portion of the femur next to the distal femoral osteotomy in 50 patients with varus knee and also a femoral anterior osteotomy with four degree (S group) and seven degree (T group) flexion angles regarding the mechanical axis. We defined the final cutting plane as the farthest position that we could reach without making a notch and the precutting plane as two millimeters anterior from the final cutting plane. The simulated resection plane was rotated to produce external and internal rotation angles of 0°, three degrees, and five degrees relative to the surgical transepicondylar axis (SEA). We investigated medial and lateral portions of the femoral anterior cutting plane length ratio (M/L).Results
When we cut parallel to SEA, M/L was 0.67 ± 0.09 and 0.62 ± 0.12 in the T and S groups, respectively. M/L was approximately 0.8 and 0.5 with five degree internal and external rotations, respectively (P < 0.01). On comparing final cutting and precutting planes, there were no significant differences in M/L without five degree external rotation in the T group and no significant difference in any case in the S group (P > 0.01).Conclusions
The ideal M/L of the femoral anterior cutting plane was 0.62–0.67. M/L did not change with a precutting plane in almost all rotational patterns. 相似文献20.
Christopher J. Maugans Matthew G. Scuderi Frederick W. Werner Stefanos F. Haddad John P. Cannizzaro 《The Knee》2017,24(2):264-270