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1.
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2.
Manabu Kawata Yusuke Sasabuchi Hiroshi Inui Shuji Taketomi Hiroki Matsui Kiyohide Fushimi Hirotaka Chikuda Hideo Yasunaga Sakae Tanaka 《The Knee》2017,24(5):1198-1205
Background
Various nationwide studies have reported differing annual trends in utilization of knee arthroplasty and tibial osteotomy. Using the Diagnosis Procedure Combination database in Japan, the present series examined annual trends and demographics in total knee arthroplasty (TKA), unicompartmental knee arthroplasty (UKA) and tibial osteotomy.Methods
All patients were identified who underwent TKA, UKA or tibial osteotomy for osteoarthritis, osteonecrosis or rheumatoid arthritis of the knee between July 2007 and March 2015.Results
A total of 170,433 cases of TKA, 13,209 cases of UKA and 8760 cases of tibial osteotomy were identified. The proportion of patients undergoing UKA rose from 4.0% in 2007 to 8.1% in 2014 (P < 0.001), and that of tibial osteotomy from 2.6% in 2007 to 5.5% in 2014 (P < 0.001); the proportion undergoing TKA fell from 93.4% in 2007 to 86.3% in 2014 (P < 0.001). Between 2007 and 2014 the proportions of patients with osteonecrosis who underwent UKA and tibial osteotomy increased from 34.7% and 11.6% to 38.6% and 16.2%, respectively (P = 0.001 for UKA and P = 0.004 for tibial osteotomy). The proportions of patients with osteonecrosis undergoing UKA or tibial osteotomy were significantly greater than those with other diagnoses (P < 0.001 for both).Conclusions
The popularity of UKA and tibial osteotomy in Japan increased during the period 2007–2014 at the expense of TKA. The proportions of UKA and tibial osteotomy in patients with osteonecrosis also increased, and were larger than those in patients with other causative diseases. 相似文献3.
Chang-Wan Kim Seung-Suk Seo Chang-Rack Lee Heui-Chul Gwak Jung-Han Kim Sun-Gyu Jung 《The Knee》2017,24(5):1099-1107
Background
To evaluate the factors that affect articular cartilage repair after open-wedge high tibial osteotomy (OWHTO) and the relationship between regeneration of articular cartilage repair and clinical outcomes.Methods
Among the cases of OWHTO that were performed from March 2005 to February 2012, the patients who followed up for > 2 years and received a second-look arthroscopy were retrospectively reviewed. For clinical evaluation, the Knee Society scores and Western Ontario and McMaster Universities Osteoarthritis Index score were measured. For radiologic evaluation, the Kellgren–Lawrence scale, mechanical femorotibial angle, and joint line obliquity were used. In the initial and second-look arthroscopy, the status of the articular cartilage of the medial compartment was evaluated.Results
A total of 62 knees (61 patients) were included in this study. Articular cartilage repair was observed in 18 knees (29.0%). In multiple logistic regression analysis, patients with Kellgren–Lawrence Grade 4 (OR 0.076; 95% CI 0.007–0.822; P = 0.034), the existence of a bipolar lesion (OR 0.108; 95% CI 0.016–0.724; P = 0.022), or joint line obliquity > 5° (OR 0.109; 95% CI 0.013–0.936; P = 0.043) had significantly lower odds of articular cartilage repair compared to the corresponding counter group. In a comparison of clinical outcomes between a group that had articular cartilage repair and a group without repair, no significant difference was observed (P > 0.05).Conclusions
Severe arthrosis, existence of a bipolar lesion, and marked postoperative joint line obliquity had a negative impact on articular cartilage repair after OWHTO. However, articular cartilage repair showed unknown clinical significance. 相似文献4.
Byung Hoon Lee Chul Won Ha Sang Won Moon Minho Chang Hun Yeong Kim Sin Hyung Park Joon Ho Wang 《The Knee》2017,24(2):362-371
Background
To assess the axial rotational change of distal tibia and posterior tibial slope (PTS) change after OWHTO in 3-D planes and to identify the causal relationship on the effect of variation in the posterior slope angle and rotational errors.Methods
A total of 21 patients (23 knees) underwent OWHTO and were evaluated with 3D-CT before and after surgery. Medial proximal tibial angle in the coronal plane, PTS in the sagittal plane, and rotational axis in axial plane were evaluated and compared between pre- and post-operative 3D models constructed by applying reverse-engineering software. As a selective osteotomy parameter, hinge axis and gap ratio were measured in the postoperative 3D modelsResults
The increasing tendency of internal rotation of the distal tibia after OWHTO was positively related to hinge axis (β = 0.730, p = 0.001, R2 = 0.546) and gap ratio (β = ? 0.283, p = 0.001, R2 = 0.520), which also showed statistically significant linear correlations to PTS changes after multivariate regression analysis that controlled for the rotational change of the distal tibia (hinge axis: β = 0.443, p = 0.006; gap ratio: β = 0.144, p = 0.017).Conclusion
Hinge axis more posterolaterally was related to a greater increase in internal rotation after biplane medial open-wedge HTO, and hinge axis and gap ratio were significant predictors of PTS change after rotational change was controlled for. Hinge axis has to be considered an important independent variable for limiting unintended axial rotation change as well as PTS change as secondary.Clinical relevance
The relationship of the hinge axis with the rotational change and its influence to PTS change, acknowledged from by-product of the statistical analysis, might provide a deeper understanding of HTO, and should have constitutional effects on the development of HTO procedures and implants. 相似文献5.
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6.
Yoshinori Ishii Hideo Noguchi Junko Sato Hana Ishii Koji Todoroki Shin-ichi Toyabe 《The Knee》2017,24(5):1153-1159
Background
Proximal tibial bone mineral density (BMD) has been studied for its potential impact on subsidence and loosening of the tibial component after total knee arthroplasty (TKA). However, no known studies of proximal tibial BMD after TKA have evaluated the effect of major impact factors such as body weight (BW), muscle strength, and level of activity. We aim to determine whether factors such as level of activity, quadriceps strength, BW, gender, age, and prosthetic design affect proximal tibial BMD over the mid- to long-term following TKA.Methods
We evaluated 36 patients (72 knees) who were undergoing bilateral TKA performed by a single surgeon. Median follow up time was 115 months (range, 60–211 months) for a minimum of five years. We measured BMD in the proximal tibia and used a hand-held dynamometer to measure quadriceps isometric strength, recording the maximum value of three measurements for each patient.Results
Univariate analyses using Spearman's correlation coefficient for continuous variables revealed a weak negative correlation between age and BMD (r = ? 0.316, P = 0.007) and a moderate positive correlation between BW and BMD (r = 0.430, P < 0.001). However, no significant correlations were found between the other factors above and BMD for continuous and discrete variables. Based on multivariate analyses, only BW had a significant effect on BMD (β = 0.342, P = 0.003).Conclusions
BW is the most impact factor on the proximal tibial BMD after mid- to long-term follow up TKA. Therefore, the management of BW may contribute to prevention of decline of tibial BMD for TKA patients owing to aging. 相似文献7.
Makoto Asaeda Masataka Deie Naoto Fujita Yoshifumi Kono Chiaki Terai Wataru Kuwahara Hodaka Watanabe Hiroaki Kimura Nobuo Adachi Toru Sunagawa Mitsuo Ochi 《The Knee》2017,24(2):280-288
Background
The aim of our study was to evaluate the effects of gender on recovery of knee joint biomechanics over the stance phase of gait after reconstruction of the anterior cruciate ligament (ACL).Methods
Gait parameters and knee joint kinematics and kinetics were compared in 32 patients (16 male and 16 female) who underwent ACL reconstruction for a unilateral ACL deficiency, with comparison to an age-, height-, and weight-matched Control group. Knee flexion, adduction and tibial rotation angles were measured and knee extension and abduction moment was calculated by inverse dynamics methods.Results
Females exhibited more tibial external rotation, in both the Control and ACL groups (P < 0.05), which was not changed after ACL reconstruction. Prior to reconstruction, sagittal plane biomechanics were changed, in both males and females, compared to the Control groups (P < 0.05). These abnormal sagittal plane mechanics were recovered at 12 months, but not six months post-reconstruction.Conclusions
We identified gender-based differences in tibial rotation that influenced the kinematics and kinetics of the knee over the stance phase of gait, both pre-operatively and post-ACL reconstruction. Evaluation of biomechanical effects of ACL injury, before and after reconstruction, should be separately evaluated for females and males. 相似文献8.
Christopher J. Maugans Matthew G. Scuderi Frederick W. Werner Stefanos F. Haddad John P. Cannizzaro 《The Knee》2017,24(2):264-270
Purpose
The purpose of this study was to determine whether a modified step-cut tibial tubercle osteotomy (Maquet–Fulkerson hybrid) might produce comparable or better results than a standard oblique anteromedialization tibial tubercle osteotomy (Fulkerson type) and thus warrant the surgical need for additional cuts.Methods
Six pairs of cadaveric knees were evaluated prior to and after tibial tubercle osteotomies. Simulation was done via a shallow knee bend simulator through 20 to 70° of knee flexion for the intact specimens and following the surgical procedures. The variables tested were trochlear contact forces and pressures and patellar motion.Results
Testing showed a decreased force (P = 0.027), peak contact pressure (P = 0.01) and contact area (P = 0.034) on the lateral trochlea of the femur for both types of osteotomies. There was no significant difference in the lateral femoral peak pressure or in the medial femoral peak pressure between the oblique cut and the step-cut. Also, there was no difference in patellar motion after either procedure.Conclusion
We conclude that both osteotomies decrease lateral patellofemoral trochlear pressure. The oblique osteotomy may decrease lateral pressure to a greater extent. Regarding biomechanical testing, there was no demonstrable advantage to performing a step-cut osteotomy. 相似文献9.
Hiroyuki Kawashima Akira Ogose Tetsuo Hotta Takashi Ariizumi Tetsuro Yamagishi Naoto Endo 《The Knee》2017,24(3):657-662
Background
Reconstruction of the extensor mechanism after resection of the proximal tibia is challenging, and several surgical procedures are available. The purpose of this study was to determine the outcome of the fibular transposition technique for reconstruction of the extensor mechanism of the knee after proximal tibial resection.Methods
We retrospectively reviewed five consecutive patients who underwent resection of the proximal tibia with prosthetic reconstruction and reconstruction of the extensor using fibular transposition between 1997 and 2011. There were two female and three male patients with a mean age of 50 years (range, 27 to 76 years). A follow-up evaluation included both passive and active range of motion, extensor lag, the MSTS score and complications.Results
Patients were followed up for 93 months (range, 44 to 160 months). The mean extensor lag and active flexion were four degrees (range, 0 to 10°) and 103° (range, 85 to 110°), respectively. The mean MSTS score was 80% (range, 73 to 90%). All patients were able to ambulate without crutches at the latest follow-up.Conclusions
The utilization of the fibular transposition technique is a simple, reliable, and successful procedure for extensor reconstruction after proximal tibial resection. 相似文献10.
Ryo Shimizu Nobuo Adachi Minoru Ishifuro Atsuo Nakamae Masakazu Ishikawa Masataka Deie Mitsuo Ochi 《The Knee》2017,24(5):1055-1066
Background
The purpose of this study was to evaluate bone tunnel changes following anterior cruciate ligament (ACL) reconstruction during the early postoperative period using computed tomography (CT), and to understand the impact of postoperative immobilization on these changes.Methods
Twenty patients who underwent double-bundle ACL reconstruction using hamstring tendon autografts were included. We subcategorized patients into two groups: patients who underwent isolated ACL reconstruction and had three days of knee immobilization (Group A, n = 10); and patients with concomitant meniscus injuries who underwent ACL reconstruction and meniscus repair simultaneously (Group B, n = 10) had their knees immobilized for two weeks after surgery. Bone tunnel enlargement was evaluated using CT imaging at one to three days, two weeks, one month, three months and six months after surgery. The cross-sectional area of the femoral and tibial tunnels was measured, and enlargement rate was calculated. The tunnel center location at two weeks after surgery was also evaluated.Results
The mean cross-sectional area adjacent to the joint space of the femoral and tibial tunnels significantly increased immediately after surgery, especially in the first month (P < 0.01). However, after one to six months they were not increased (P > 0.01). There was no significant difference in tunnel enlargement rate between group A and B. Tunnel center location changed even in the first two weeks.Conclusions
Bone tunnel enlargement following double-bundle ACL reconstruction occurred at an earlier time point after surgery than anticipated. Postoperative immobilization could not prevent bone tunnel enlargement, but might prevent tunnel migration. 相似文献11.
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12.
Ron Batash Guy Rubin Alexander Lerner Hussein Shehade Nimrod Rozen David E. Rothem 《The Knee》2017,24(3):622-626
Background
Successful total knee arthroplasty (TKA) includes accurate alignment. Controversy remains as to whether computer-navigated TKA improves the overall result and clinical outcome. Our aim is to compare the limb alignment and prosthesis positioning according to the pre- and postoperative computed tomography (CT) scans with the data collected from the navigation system.Methods
We compared the pre- and postoperative limb alignments and prosthesis alignment provided by the Orthopilot navigation system, Aesculap®, with CT scans measured by the Traumacad® software of 70 TKAs.Results
A positive correlation with statistical significance (P = 0.00001, r = 0.874) between the navigation system data and the CT images was found. Mean femoral cut was five degrees (valgus), and mean tibial cut was one degree (varus). Our study revealed that the navigation system assisted the surgeon to implant the prosthesis at a good acceptable alignment.Conclusion
We found that the navigation system is accurate and correlates to the pre- and postoperative CT scans. Furthermore, the navigation system can assist the surgeon to achieve good limb alignment and cutting planes of the prosthesis. 相似文献13.
Suguru Nakamura Yukihide Minoda Shigeru Nakagawa Yoshinori Kadoya Susumu Takemura Akio Kobayashi Shigekazu Mizokawa Yoichi Ohta Sinji Takahashi Kazumasa Yamamura Hiroaki Nakamura 《The Knee》2017,24(2):434-438
Background
The medial pivot total knee prosthesis with alumina ceramic femoral components was introduced to reproduce physiological knee kinematics and reduce polyethylene wear. The five-year clinical outcomes of alumina medial pivot total knee arthroplasties (TKA) have previously been reported. The purpose of this study was to provide the longer-term clinical results at a minimum follow-up of 10 years.Methods
The clinical results of 70 alumina medial pivot TKA in 51 consecutive patients, with a minimum follow-up period of 10 years, were evaluated.Results
Mean follow-up was 11.8 years (range 10 to 13). Alumina medial pivot TKAs improved the patients' Knee Society knee scores, function scores, and postoperative ranges of motion compared with their pre-operative statuses (P < 0.05 for each). Revision surgery was required in one knee due to a postoperative fracture of the tibial plateau after a fall that occurred two years postoperatively. Osteolysis and femoral component loosening was identified in one case after the initial five-year time point of analysis. The survival rate was 99.1% at 10 years.Conclusions
This study demonstrated excellent clinical results for patients receiving the alumina medial pivot prosthesis at a minimum follow-up period of 10 years. 相似文献14.
Michael Worlicek Benedikt Moser Günther Maderbacher Raphael Zentner Florian Zeman Joachim Grifka Armin Keshmiri 《The Knee》2017,24(4):711-717
Background
Patellofemoral instability may lead to osteoarthritis, anterior knee pain, and patellar luxation. The purpose of this study was to conduct an exploratory investigation into the difference of patellar kinematics of healthy knees during extension/flexion cycles in neutral, varus and valgus alignment.Methods
The three-dimensional patellar kinematics of 10 lower extremities of whole body cadavers were examined during passive motion, in neutral position, and under valgus and varus stress. Kinematics was recorded by means of an optical computer navigation system.Results
The study samples did not significantly differ with regard to mediolateral patellar shift and epicondylar distance. Varus stress led to significantly higher external rotation than valgus stress (P = 0.04) and to a significantly higher lateral patellar tilt than neutral position (P = 0.016) and valgus stress (P = 0.016). No difference was found between valgus stress and neutral position.Conclusion
Analysis of tibiofemoral alignment alone is insufficient for predicting patellar kinematics. 相似文献15.
Arne Ekeland Tor Kjetil Nerhus Sigbjørn Dimmen Elisabeth Thornes Stig Heir 《The Knee》2017,24(2):380-389
Background
To report time dependent functional improvement and predictive risk factors for failure when the load in varus knees with medial osteoarthritis is shifted from the medial to the lateral knee compartment.Methods
Forty-nine consecutive patients (52 knees), mean age 47 (31–64) years, underwent a high tibial opening-wedge valgus osteotomy stabilized with a Puddu plate and bone grafting. The patients were evaluated with the Knee Injury and Osteoarthritis Outcome Score (KOOS) preoperatively and at three and six months, one, two, five and 10 years postoperatively with a mean follow-up time of 8.3 years (2.0–10.6).Results
Mean angular correction was 8.0° (four to 12). The five subscores of KOOS increased significantly during the first year by 40–131% from preoperative values, the good results remaining throughout the 10-year follow-up for those with a surviving osteotomy. The outcome was related to the grade of preoperative osteoarthritis. Seven knees were converted to total knee arthroplasty (TKA) mean 6.2 years (two to nine) post-operatively, and had a lower KOOS preoperatively than those of surviving osteotomies. The osteotomy survival rate at five years was 94% and at 10 years 83%. Patients with KOOS subscore quality of life (QoL) < 44 at the two-year follow-up had a 11.7 times higher risk for later TKA than those with QoL ≥ 44 (P = 0.017).Conclusion
High tibial opening-wedge osteotomy for medial knee osteoarthritis resulted in good functional recovery after one year and favorable mid-term results. It may be a good treatment option for middle-aged patients with varus knees and medial osteoarthritis in order to prevent or postpone TKA. 相似文献16.
Seong Hwan Kim Du-Hyun Ro Young-Min Lee Yool Cho Sahnghoon Lee Myung-Chul Lee 《The Knee》2017,24(5):1129-1137
Background
To evaluate the difference between preoperative plan and postoperative alignment after closed-wedge HTO and determine factors associated with difference.Methods
This retrospective cohort study included 165 cases with closed-wedge HTO. The following radiographic parameters were measured: mechanical tibiofemoral angle (mTFA), mechanical medial proximal tibial angle (MPTA), joint line convergence angle, mediolateral joint width discrepancy, Kellgren–Lawrence (K–L) grade, and discrepancy between the correction angle in tibia and correction angle in mTFA. The linear regression analysis was used for the preoperative factors that affect the discrepancy between correction angle in tibia and correction angle in mTFA.Results
Preoperative and postoperative mTFA was varus 8.3° ± 3.7 and valgus 3.1° ± 2.6. The MPTA was varus 6.2° ± 3.1 preoperatively, valgus 3.7° ± 3.0 postoperatively. The mediolateral joint width discrepancy was 3.1 mm ± 1.8 preoperatively and 1.8 mm ± 1.4 postoperatively. The discrepancy between correction angle in tibia and correction angle in mTFA was 1.5° ± 2.3 valgus. By regression analysis, one degree of valgus overcorrection was found to be related with every 2.5° of joint convergence angle (r2 = 0.396), 2.4 mm of mediolateral joint width discrepancy (r2 = 0.310) and increased one grade of K–L classification (r2 = 0.107) as preoperative measurement.Conclusions
The 1.5° valgus overcorrection of postoperative mTFA was found compared with planned correction angle in tibia. By the equation, every 2.5° of joint convergence angle and 2.4 mm of mediolateral joint width discrepancy preoperatively could predict one degree of valgus overcorrection. 相似文献17.
Ryan T. Lewinson Chad P. Maag Victor M.Y. Lun J. Preston Wiley Chirag Patel Darren J. Stefanyshyn 《The Knee》2017,24(1):31-39
Background
Clinical effectiveness of lateral wedges for knee osteoarthritis is inconsistent across studies. One explanation is that knee loading is not fully described by the peak frontal-plane knee moment. The purpose of this study was to propose a 3D resultant approach to describing moments at the knee and evaluate how this moment changes in response to lateral wedges.Methods
Walking gait analysis was performed on 20 individuals with knee osteoarthritis, in their own shoes, with and without a six millimeter lateral wedge insole. Frontal-plane and 3D resultant moments were calculated for each participant and footwear condition. Paired t-tests identified differences between footwear conditions, correlations identified relationships between frontal-plane and 3D resultant moments, and regressions assessed relationships between moments and pain.Results
Significant reductions to peak frontal-plane moments (p = 0.001) and 3D resultant moments at the same time point (p = 0.042) were observed with lateral wedges. While an overall significant correlation was observed between change in frontal-plane moments and change in 3D resultant moments with a lateral wedge (r = 0.68, p = 0.001), 5/20 participants experienced disparate results where the frontal-plane moment was reduced yet the 3D moment increased.Conclusions
While lateral wedges alter frontal-plane moment magnitude, the direction of change does not always correspond to the direction of change observed in the 3D resultant moment. Thus resultant knee load may sometimes increase with lateral wedges.Clinical relevance
Future prospective studies should evaluate if changes in 3D resultant moments, and thus total knee load, offer an explanation as to why some participants do not experience clinical benefit from lateral wedges. 相似文献18.
Christian Scheele Matthias F. Pietschmann Christian Schröder Thomas Grupp Melanie Holderied Volmar Jansson Peter E. Müller 《The Knee》2017,24(2):402-408
Background
Unicompartmental total knee arthroplasty (UKA) is a well-established treatment option for unicondylar osteoarthritis, and generally leads to better functional results than tricompartimental total knee arthroplasty (TKA). However, revision rates of UKAs are reported as being higher; a major reason for this is aseptic loosening of the tibial component due to implant–cement–bone interface fatigue. The objective of this study was to determine the effects of trabecular bone preparation, prior to implantation of tibial UKAs, on morphological and biomechanical outcomes in a cadaver study.Methods
Cemented UKAs were performed in 18 human cadaver knees after the bone bed was cleaned using pulsed lavage (Group A), conventional brush (Group B) or no cleaning at all (Group C, control). Morphologic cement penetration and primary stability were measured.Results
The area proportion under the tibial component without visible cement penetration was significantly higher in Group C (21.9%, SD 11.9) than in both Group A (7.1%, SD 5.8), and Group B (6.5%, SD 4.2) (P = 0.007). The overall cement penetration depth did not differ between groups. However, in the posterior part, cement penetration depth was significantly higher in Group B (1.9 mm, SD 0.3) than in both Group A (1.3 mm, SD 0.3) and Group C (1.4 mm, SD 0.3) (P = 0.015). The mode of preparation did not show a substantial effect on primary stability tested under dynamic compression-shear test conditions (P = 0.910).Conclusion
Bone preparation significantly enhances cement interdigitation. The application of a brush shows similar results compared with the application of pulsed lavage. 相似文献19.
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20.