Purpose: This clinical fluoroscopy study investigated knee kinematics of two different cemented fixed‐bearing, posterior‐stabilised (PS) total knee arthroplasty (TKA) designs: an asymmetric tibial... Show morePurpose: This clinical fluoroscopy study investigated knee kinematics of two different cemented fixed‐bearing, posterior‐stabilised (PS) total knee arthroplasty (TKA) designs: an asymmetric tibial component including an asymmetric insert designed to optimise personalised balance and fit and its precursor symmetrical design with symmetric insert. Methods: A consecutive series of patients (16 TKAs from each treatment group) participating in a randomised controlled trial comparing TKA migration was included. The exclusion criterion was the use of walking aids. Flat‐panel fluoroscopic recordings of step‐up and lunge motions were acquired 1‐year postoperatively. Medial and lateral contact points (CPs) were determined to calculate CP displacement, femoral axial rotation and pivot position. Using linear mixed‐effects modelling techniques, kinematics between TKA designs were compared. Results: During knee extension between 20° flexion and full extension, the CPs moved anteriorly combined with a small internal femoral rotation (a screw‐home mechanism). Whereas CP movement was reversed: femoral rollback, external femoral rotation while flexing the knee between full extension and 20° knee flexion, At larger flexion angles, femoral axial rotation (FAR) occurred around a lateral pivot point both during step‐up and lunge. The symmetric design had a 2.3° larger range of FAR compared to the asymmetric design during lunge (p = 0.02). All other kinematics were comparable. Conclusion: Despite the differences in design, this study showed that the asymmetric and symmetric PS TKA designs had mostly comparable knee kinematics during step‐up and lunge motions. It is therefore expected that the functionality of the successor TKA design is similar to that of its precursor design. Show less
Budhiparama, N.C.; Lumban-Gaol, I.; Novito, K.; Hidayat, H.; Meo, F. de; Cacciola, G.; Cavaliere, P. 2023
PurposeMedial pivot (MP) designs resemble native knee kinematics and restore the "natural" kinematics of a knee after total knee arthroplasty (TKA). However, whether to preserve or resect the... Show morePurposeMedial pivot (MP) designs resemble native knee kinematics and restore the "natural" kinematics of a knee after total knee arthroplasty (TKA). However, whether to preserve or resect the posterior cruciate ligament (PCL) is still under debate. We inquired whether sacrificing the PCL would improve range of motion, functional outcomes, and limb alignment compared to preserving the PCL in TKA using medial pivot implants (MP-TKA).MethodsThis prospective, double-blinded, randomized controlled trial consisted of 33 patients (66 knees) undergoing bilateral simultaneous MP-TKA. In one knee, a PCL preservation technique was performed, and in the contralateral knee, the PCL was resected. The primary outcome was postoperative range of motion (ROM). The secondary outcomes were visual analogue scale (VAS) score for knee pain at walking, Knee Injury and Osteoarthritis Outcome Score for symptoms (KOOS-S) and quality of life (KOOS-QoL), Oxford knee score (OKS), and Forgotten Joint Score (FJS), and measurement of the mechanical femoral-tibial axis (mFTA) on X-ray images. All patients were followed up for a minimum of 2 years after surgery.ResultsPatients who underwent MP-TKA with PCL preservation had a similar ROM at 2 years (125.45 +/- 7.00 vs. 126.21 +/- 6.73, p = 0.65) as those who underwent MP-TKAs with PCL resection. There was also no difference in VAS score (1.94 +/- 0.79 vs. 2.00 +/- 0.71, respectively, p = 0.51), OKS (39.97 +/- 2.01 vs. 39.67 +/- 2.03, respectively, p = 0.52), KOOS-S (84.41 +/- 3.77 vs. 84.19 +/- 3.57, respectively, p = 0.92), KOOS-QoL (82.94 +/- 4.76 vs. 82.75 +/- 4.70, respectively, p = 0.84), or FJS (72.66 +/- 8.99 vs. 72.35 +/- 8.64, respectively, p = 0.76) at the 2-year follow-up. No difference in the measurement of the mFTA was found between the two groups (180.27 +/- 2.25 vs. 181.30 +/- 2.13, respectively, p = 0.59).ConclusionThis study demonstrated that both medial pivot TKA with PCL preservation and PCL resection achieved excellent results. There was no difference at the 2-year follow-up in terms of postoperative ROM, patient-reported outcomes, or radiographic evaluation.Level of EvidenceTherapeutic study, Level I. Show less
Purpose - The aim of this prospective randomised controlled study was to compare wear characteristics and functional outcome between deep-dished mobile bearing (MB) and fixed bearing (FB) cemented... Show morePurpose - The aim of this prospective randomised controlled study was to compare wear characteristics and functional outcome between deep-dished mobile bearing (MB) and fixed bearing (FB) cemented total knee arthroplasty (TKA). We hypothesised that deep-dished MB reduces polyethylene wear and improves patient-reported outcome measures.MethodsA total of 50 patients were randomised to receive a MB or FB tibia component of the same cemented TKA design. Patients were evaluated over a 5-year follow-up period. Medial and lateral wear were assessed using model-based Roentgen Stereophotogrammetric Analysis (RSA) and compared with the direct postoperative minimal joint space measurement. Functional outcome was assessed by the clinician-derived KSS and OKS, WOMAC, LEAS, and FJS-12. All data were derived using a general linear mixed model.Results - At 5-year follow-up, decreased wear in the MB compared to the FB group was observed on the lateral side (0.07 +/- 0.17 mm, p = 0.026), but not on the medial side (0.31 +/- 0.055 mm, p = 0.665). Functional outcomes improved with a statistical significant effect over time, with no significant differences between groups (all p > 0.17).ConclusionThis model-based RSA study with 5-year follow-up showed that cemented deep-dished MB reduced lateral polyethylene wear as compared to FB in a single TKA system, whilst clinical outcomes were comparable. Longer follow-up is needed to establish clinical implications of these altered wear patterns and determine type of wear. Show less
Easwaran, R.; Khan, M.; Sancheti, P.; Shyam, A.; Bhandari, M.; Ranawat, A.S.; ... ; Rajgopal, A. 2022
Purpose There is a lack of consensus regarding need for Venous Thrombo Embolism (VTE) prophylaxis following arthroscopic knee surgery and open soft tissue knee reconstruction. Clear cut guidelines... Show morePurpose There is a lack of consensus regarding need for Venous Thrombo Embolism (VTE) prophylaxis following arthroscopic knee surgery and open soft tissue knee reconstruction. Clear cut guidelines like ones for trauma surgery and arthroplasty do not exist and the published literature is limited to case reports with a few society guidelines. Given this lack of consensus, we conducted a modified Delphi questionnaire of international experts to provide recommendations on this topic. Methods The consensus statements were generated using an anonymised 3 round modified Delphi questionnaire, sent to an international panel of 38 knee surgeons, with an 80% agreement being set as the limit for consensus. The responses were analysed using descriptive statistics with measures like mode, median and box plots. Feedback was provided to all panelists based on responses from the previous rounds to help generate the consensus. Results Six consensus statements were generated after the three rounds of Delphi. Patient factors, prolonged surgery duration and family history of thrombogenic events emerged as the main points to be taken into consideration for prophylaxis. Conclusion It was established through this study, that there exists a select group of patients undergoing arthroscopic surgery that justify the usage of VTE prophylaxis. The expert responses to most of the questions in different scenarios favoured usage of VTE prophylaxis based on patient factors like advanced age, past history of VTE, smoking, oral contraceptive use etc. Show less
Rietbergen, T.; Marang-van de Mheen, P.J.; Graaf, J. de; Diercks, R.L.; Janssen, R.P.A.; Linden-van der Zwaag, H.M.J. van der; ... ; SMART Study Grp 2022
Purpose: To evaluate the effectiveness of a tailored intervention to reduce low value MRIs and arthroscopies among patients >= 50 years with degenerative knee disease in 13 Dutch orthopaedic... Show morePurpose: To evaluate the effectiveness of a tailored intervention to reduce low value MRIs and arthroscopies among patients >= 50 years with degenerative knee disease in 13 Dutch orthopaedic centers (intervention group) compared with all other Dutch orthopaedic centers (control group). Methods: All patients with degenerative knee disease >= 50 years admitted to Dutch orthopaedic centers from January 2016 to December 2018 were included. The tailored intervention included participation of clinical champions, education on the Dutch Choosing Wisely recommendation for MRI's and arthroscopies in degenerative knee disease, training of orthopaedic surgeons to manage patient expectations, performance feedback, and provision of a patient brochure. A difference-in-difference analysis was used to compare the time trend before (admitted January 2016-June 2017) and after introduction of the intervention (July 2017-December 2018) between intervention and control hospitals. Primary outcome was the monthly percentage of patients receiving a MRI or knee arthroscopy, weighted by type of hospital. Results: 136,446 patients were included, of whom 32,163 were treated in the intervention hospitals. The weighted percentage of patients receiving a MRI on average declined by 0.15% per month (beta = - 0.15, P < 0.001) and by 0.19% per month for arthroscopy (beta = - 0.19, P < 0.001). However, these changes over time did not differ between intervention and control hospitals, neither for MRI (beta = - 0.74, P = 0.228) nor arthroscopy (beta = 0.13, P = 0.688). Conclusions: The extent to which patients >= 50 years with degenerative knee disease received a MRI or arthroscopy declined significantly over time, but could not be attributed to the tailored intervention. This secular downward time trend may reflect anoverall focus of reducing low value care in The Netherlands. Show less
Noorduyn, J.C.A.; Graaf, V.A. van de; Willigenburg, N.W.; Scholten-Peeters, G.G.M.; Mol, B.W.; Heymans, M.W.; ... ; ESCAPE Res Grp 2022
Purpose Marker-by-treatment analyses are promising new methods in internal medicine, but have not yet been implemented in orthopaedics. With this analysis, specific cut-off points may be obtained,... Show morePurpose Marker-by-treatment analyses are promising new methods in internal medicine, but have not yet been implemented in orthopaedics. With this analysis, specific cut-off points may be obtained, that can potentially identify whether meniscal surgery or physical therapy is the superior intervention for an individual patient. This study aimed to introduce a novel approach in orthopaedic research to identify relevant treatment selection markers that affect treatment outcome following meniscal surgery or physical therapy in patients with degenerative meniscal tears. Methods Data were analysed from the ESCAPE trial, which assessed the treatment of patients over 45 years old with a degenerative meniscal tear. The treatment outcome of interest was a clinically relevant improvement on the International Knee Documentation Committee Subjective Knee Form at 3, 12, and 24 months follow-up. Logistic regression models were developed to predict the outcome using baseline characteristics (markers), the treatment (meniscal surgery or physical therapy), and a marker-by-treatment interaction term. Interactions with p < 0.10 were considered as potential treatment selection markers and used these to develop predictiveness curves which provide thresholds to identify marker-based differences in clinical outcomes between the two treatments. Results Potential treatment selection markers included general physical health, pain during activities, knee function, BMI, and age. While some marker-based thresholds could be identified at 3, 12, and 24 months follow-up, none of the baseline characteristics were consistent markers at all three follow-up times. Conclusion This novel in-depth analysis did not result in clear clinical subgroups of patients who are substantially more likely to benefit from either surgery or physical therapy. However, this study may serve as an exemplar for other orthopaedic trials to investigate the heterogeneity in treatment effect. It will help clinicians to quantify the additional benefit of one treatment over another at an individual level, based on the patient's baseline characteristics. Show less
Gerritsen, L.M.; Lelij, T.J.N. van der; Schie, P. van; Fiocco, M.; Arkel, E.R.A. van; Zuurmond, R.G.; ... ; Driel, P.B.A.A. van 2022
Purpose The purpose of this study was to determine and compare the percentage of completely healed meniscal tears after arthroscopic repair combined with anterior cruciate ligament reconstruction ... Show morePurpose The purpose of this study was to determine and compare the percentage of completely healed meniscal tears after arthroscopic repair combined with anterior cruciate ligament reconstruction (ACLR) for the different vascular zones of the meniscus. Methods PubMed, Embase, Web of Science, Cochrane library and Emcare were searched on 19 May 2020 for articles reporting healing rates after arthroscopic meniscal repair with concomitant ACLR for the different meniscal vascular zones as assessed by second-look arthroscopy. Data on meniscal tears were extracted as located in zones 1, 2 or 3, according to the Cooper classification. Studies were graded in quality using a modified Newcastle-Ottawa Scale. Pooled analyses were performed utilizing a random-effects model. Meta-analyses were performed using R version 3.6.2 and SPSS statistical software version 25.0. The study was registered with PROSPERO (ID:CRD42020176175). Results Ten observational cohort studies met the inclusion criteria, accounting for 758 meniscal tear repairs in total. The pooled overall proportion of healing was 78% (95% CI 72-84%). The mean weighted proportion of healing was 83% (95% CI 76-90%) for studies (n = 10) reporting zone 1 tears and 69% (95% CI 59-79%) for studies (n = 9) reporting zone 2 tears. No study reported healing rates for zone 3 tears. The pooled overall odds ratio was 2.5 (95% CI 1.00-6.02), indicating zone 1 tears as 2.5 times more likely to heal than zone 2 tears. Conclusion This study demonstrates that meniscal tears localized in vascular zone 1 were more likely to heal than those in zone 2. Show less
Gerritsen, L.M.; Lelij, T.J.N. van der; Schie, P. van; Fiocco, M.; Arkel, E.R.A. van; Zuurmond, R.G.; ... ; Driel, P.B.A.A. van 2022
Purpose: The purpose of this study was to determine and compare the percentage of completely healed meniscal tears after arthroscopic repair combined with anterior cruciate ligament reconstruction ... Show morePurpose: The purpose of this study was to determine and compare the percentage of completely healed meniscal tears after arthroscopic repair combined with anterior cruciate ligament reconstruction (ACLR) for the different vascular zones of the meniscus. Methods: PubMed, Embase, Web of Science, Cochrane library and Emcare were searched on 19 May 2020 for articles reporting healing rates after arthroscopic meniscal repair with concomitant ACLR for the different meniscal vascular zones as assessed by second-look arthroscopy. Data on meniscal tears were extracted as located in zones 1, 2 or 3, according to the Cooper classification. Studies were graded in quality using a modified Newcastle-Ottawa Scale. Pooled analyses were performed utilizing a random-effects model. Meta-analyses were performed using R version 3.6.2 and SPSS statistical software version 25.0. The study was registered with PROSPERO (ID:CRD42020176175). Results: Ten observational cohort studies met the inclusion criteria, accounting for 758 meniscal tear repairs in total. The pooled overall proportion of healing was 78% (95% CI 72-84%). The mean weighted proportion of healing was 83% (95% CI 76-90%) for studies (n = 10) reporting zone 1 tears and 69% (95% CI 59-79%) for studies (n = 9) reporting zone 2 tears. No study reported healing rates for zone 3 tears. The pooled overall odds ratio was 2.5 (95% CI 1.00-6.02), indicating zone 1 tears as 2.5 times more likely to heal than zone 2 tears. Conclusion: This study demonstrates that meniscal tears localized in vascular zone 1 were more likely to heal than those in zone 2. Show less
Schie, P. van; Lelij, T.J.N. van der; Gerritsen, M.; Meijer, R.P.J.; Arkel, E.R.A. van; Fiocco, M.; ... ; Driel, P.B.A.A. van 2021
Purpose The purpose of this study was to assess whether the vascularisation of the meniscus could be visualised intra-operatively using near-infrared fluorescence (NIRF) imaging with indocyanine... Show morePurpose The purpose of this study was to assess whether the vascularisation of the meniscus could be visualised intra-operatively using near-infrared fluorescence (NIRF) imaging with indocyanine green (ICG) in patients undergoing total knee arthroplasty (TKA). Methods The anterior horn (i.e., Cooper classification: zones C and D) of the meniscus that was least affected (i.e., least degenerative) was removed during TKA surgery in ten patients to obtain a cross section of the inside of the meniscus. Thereafter, 10 mg of ICG was injected intravenously, and vascularisation of the cross section of the meniscus was assessed using the Quest spectrum NIRF camera system. We calculated the percentage of patients in whom vascularisation was observed intra-operatively using NIRF imaging compared to immunohistochemistry. Results Meniscal vascularisation using NIRF imaging was observed in six out of eight (75%) patients in whom vascularisation was demonstrated with immunohistochemistry. The median extent of vascularisation was 13% (interquartile range (IQR) 3-28%) using NIRF imaging and 15% (IQR 11-23%) using immunohistochemistry. Conclusion This study shows the potential of NIRF imaging to visualise vascularisation of the meniscus, as vascularisation was observed in six out of eight patients with histologically proven meniscal vascularisation. Show less
Rietbergen, T.; Marang-van de Mheen, P.J.; Diercks, R.L.; Janssen, R.P.A.; Linden-van der Zwaag, H.M.J. van der; Nelissen, R.G.H.H.; ... ; SMART Study Grp 2021
Purpose The purpose of this study was to assess in which proportion of patients with degenerative knee disease aged 50+ in whom a knee arthroscopy is performed, no valid surgical indication is... Show morePurpose The purpose of this study was to assess in which proportion of patients with degenerative knee disease aged 50+ in whom a knee arthroscopy is performed, no valid surgical indication is reported in medical records, and to explore possible explanatory factors.Methods A retrospective study was conducted using administrative data from January to December 2016 in 13 orthopedic centers in the Netherlands. Medical records were selected from a random sample of 538 patients aged 50+ with degenerative knee disease in whom arthroscopy was performed, and reviewed on reported indications for the performed knee arthroscopy. Valid surgical indications were predefined based on clinical national guidelines and expert opinion (e.g., truly locked knee). A knee arthroscopy without a reported valid indication was considered potentially low value care. Multivariate logistic regression analysis was performed to assess whether age, diagnosis ("Arthrosis" versus "Meniscal lesion"), and type of care trajectory (initial or follow-up) were associated with performing a potentially low value knee arthroscopy.Results Of 26,991 patients with degenerative knee disease, 2556 (9.5%) underwent an arthroscopy in one of the participating orthopedic centers. Of 538 patients in whom an arthroscopy was performed, 65.1% had a valid indication reported in the medical record and 34.9% without a reported valid indication. From the patients without a valid indication, a joint patient-provider decision or patient request was reported as the main reason. Neither age [OR 1.013 (95% CI 0.984-1.043)], diagnosis [OR 0.998 (95% CI 0.886-1.124)] or type of care trajectory [OR 0.989 (95% CI 0.948-1.032)] were significantly associated with performing a potentially low value knee arthroscopy.Conclusions In a random sample of knee arthroscopies performed in 13 orthopedic centers in 2016, 65% had valid indications reported in the medical records but 35% were performed without a reported valid indication and, therefore, potentially low value care. Patient and/or surgeons preference may play a large role in the decision to perform an arthroscopy without a valid indication. Therefore, interventions should be developed to increase adherence to clinical guidelines by surgeons that target invalid indications for a knee arthroscopy to improve care. Show less
Noorduyn, J.C.A.; Teuwen, M.M.H.; Graaf, V.A. van de; Willigenburg, N.W.; Schavemaker, M.; Dijk, R. van; ... ; Escape Res Grp 2021
Purpose Although physical therapy is the recommended treatment in patients over 45 years old with a degenerative meniscal tear, 24% still opt for meniscal surgery. The aim was to identify those... Show morePurpose Although physical therapy is the recommended treatment in patients over 45 years old with a degenerative meniscal tear, 24% still opt for meniscal surgery. The aim was to identify those patients with a degenerative meniscal tear who will undergo surgery following physical therapy. Methods The data for this study were generated in the physical therapy arm of the ESCAPE trial, a randomized clinical trial investigating the effectiveness of surgery versus physical therapy in patients of 45-70 years old, with a degenerative meniscal tear. At 6 and 24 months patients were divided into two groups: those who did not undergo surgery, and those who did undergo surgery. Two multivariable prognostic models were developed using candidate predictors that were selected from the list of the patients' baseline variables. A multivariable logistic regression analysis was performed with backward Wald selection and a cut-off of p < 0.157. For both models the performance was assessed and corrected for the models' optimism through an internal validation using bootstrapping technique with 500 repetitions. Results At 6 months, 32/153 patients (20.9%) underwent meniscal surgery following physical therapy. Based on the multivariable regression analysis, patients were more likely to opt for meniscal surgery within 6 months when they had worse knee function, lower education level and a better general physical health status at baseline. At 24 months, 43/153 patients (28.1%) underwent meniscal surgery following physical therapy. Patients were more likely to opt for meniscal surgery within 24 months when they had worse knee function and a lower level of education at baseline at baseline. Both models had a low explained variance (16 and 11%, respectively) and an insufficient predictive accuracy. Conclusion Not all patients with degenerative meniscal tears experience beneficial results following physical therapy. The non-responders to physical therapy could not accurately be predicted by our prognostic models. Show less
Rietbergen, T.; Diercks, R.L.; Anker-van der Wel, I.; Akker-van Marle, M.E. van den; Lopuha?, N.; Janssen, R.P.A.; ... ; Bodegom-Vos, L. van 2020
Purpose The purpose of this study was to assess which factors were associated with the implementation of "Choosing Wisely" recommendations to refrain from routine MRI and arthroscopy use in... Show morePurpose The purpose of this study was to assess which factors were associated with the implementation of "Choosing Wisely" recommendations to refrain from routine MRI and arthroscopy use in degenerative knee disease. Methods Cross-sectional surveys were sent to 123 patients (response rate 95%) and 413 orthopaedic surgeons (response rate 62%) fulfilling the inclusion criteria. Univariate and multivariate logistic regression analyses were used to identify factors associated with implementation of "Choosing Wisely" recommendations. Results Factors reducing implementation of the MRI recommendation among patients included explanation of added value by an orthopaedic surgeon [OR 0.18 (95% CI 0.07-0.47)] and patient preference for MRI [OR 0.27 (95% CI 0.08-0.92)]. Factors reducing implementation among orthopaedic surgeons were higher valuation of own MRI experience than existing evidence [OR 0.41 (95% CI 0.19-0.88)] and higher estimated patients' knowledge to participate in shared decision-making [OR 0.38 (95% CI 0.17-0.88)]. Factors reducing implementation of the arthroscopy recommendation among patients were orthopaedic surgeons' preferences for an arthroscopy [OR 0.03 (95% CI 0.00-0.22)] and positive experiences with arthroscopy of friends/family [OR 0.03 (95% CI 0.00-0.39)]. Factors reducing implementation among orthopaedic surgeons were higher valuation of own arthroscopy experience than existing evidence [OR 0.17 (95% CI 0.07-0.46)] and belief in the added value [OR 0.28 (95% CI 0.10-0.81)]. Conclusions Implementation of "Choosing Wisely" recommendations in degenerative knee disease can be improved by strategies to change clinician beliefs about the added value of MRIs and arthroscopies, and by patient-directed strategies addressing patient preferences and underlying beliefs for added value of MRI and arthroscopies resulting from experiences of people in their environment. Show less
Purpose Evaluation of survival of meniscal allograft transplantation (MAT) and postoperative patient-reported outcome (PRO), and their association with prior interventions of the knee. Methods A... Show morePurpose Evaluation of survival of meniscal allograft transplantation (MAT) and postoperative patient-reported outcome (PRO), and their association with prior interventions of the knee. Methods A prospective consecutive study of 109 consecutive patients who had an arthroscopic meniscal allograft transplantation (MAT) between 1999 and 2017 by a single surgeon. Patients were assessed with KOOS scores, preoperative and after a minimal follow-up of 2 years. Furthermore, two anchor questions (whether expectations were met and overall satisfaction, on a five-point Likert scale) were asked. Additionally, prior interventions to MAT were evaluated. Results Prior to MAT, patients had undergone an average of 2.8 (range 1-14) of surgical procedures of the knee. Overall, mean allograft survival was 16.1 years (95% CI 14.8-17.5 years). Higher age at surgery was associated with lower MAT survival: hazard ratio for MAT failure was 1.19 per year increase (95% CI 1.04 to 1.36,p = 0.009). At 4.5 years (IQR, 2-9) of follow-up, all KOOS score were still improved compared to baseline. Age below 35 years, simultaneous anterior cruciate ligament reconstruction and number of knee surgeries before MAT were associated with lower KOOS scores. Overall patient expectations and overall satisfaction after MAT were not associated with preoperative patient characteristics nor with the number or kind of preoperative interventions. Conclusion Meniscal allograft transplantation has a good overall survival with a clinically relevant improvement. Both meniscal allograft survival and PRO were associated with age. PRO was lower in patients younger than 35 years at time of MAT and meniscal allograft survival was worse in patients older than 50 years. PRO was associated with preoperative patient characteristics and number of surgical procedures prior to MAT. All patients reported improved postoperative satisfaction and met expectations after MAT, both independent of the preoperative history of knee interventions. Show less
Purpose The aim of this study was to evaluate the anthropometric differences between knees of Indonesian Asians and Dutch Caucasians and the fit of nine different knee implant systems. Methods A... Show morePurpose The aim of this study was to evaluate the anthropometric differences between knees of Indonesian Asians and Dutch Caucasians and the fit of nine different knee implant systems. Methods A total of 268 anteroposterior (AP) and lateral knee preoperative radiographs from 134 consecutive patients scheduled for total knee arthroplasty at two different centres in Jakarta and Leiden were included. Both patient groups were matched according to age and sex and included 67 Asians and 67 Caucasians. We assessed the radiographic differences between the Asian and Caucasian anthropometric data. The dimensions of the nine knee implant designs (Vanguard, Genesis II, Persona Standard, Persona Narrow, GK Sphere, Gemini, Attune Standard, Attune Narrow, and Sigma PFC) were compared with the patients' anthropometric (distal femur and proximal tibia) measurements. Results The Dutch Caucasian patients had larger mediolateral (ML) and AP femoral and tibial dimensions than the Indonesian Asians. The aspect ratios of the distal femur and tibia were larger in Asians than in Caucasians. The AP and ML dimensions were mismatched between the tibial components of the nine knee systems and the Asian anthropometric data. Both groups had larger ML distal femoral dimensions than the knee systems. Conclusion Absolute and relative differences in knee dimensions exist not only between Asian and Caucasian knees but also within both groups. Not all TKA systems had a good fit with the Asian and Caucasian knee phenotypes. An increase in the range of available knee component sizes would be beneficial, although TKA remains an adequate compromise. Show less
PURPOSE: The aim of this study was to compare a broad range of total knee prostheses with different design parameters to determine whether in vivo kinematics was consistently related to design. The... Show morePURPOSE: The aim of this study was to compare a broad range of total knee prostheses with different design parameters to determine whether in vivo kinematics was consistently related to design. The hypothesis was that there are no clear recognizable differences in in vivo kinematics between different design parameters or prostheses. METHODS: At two sites, data were collected by a single observer on 52 knees (49 subjects with rheumatoid arthritis or osteoarthritis). Six different total knee prostheses were used: multi-radius, single-radius, fixed-bearing, mobile-bearing, posterior-stabilized, cruciate retaining and cruciate sacrificing. Knee kinematics was recorded using fluoroscopy as the patients performed a step-up motion. RESULTS: There was a significant effect of prosthetic design on all outcome parameters; however, post hoc tests showed that the NexGen group was responsible for 80% of the significant values. The range of knee flexion was much smaller in this group, resulting in smaller anterior-posterior translations and rotations. CONCLUSION: Despite kinematics being generally consistent with the kinematics intended by their design, there were no clear recognizable differences in in vivo kinematics between different design parameters or prostheses. Hence, the differences in design parameters or prostheses are not distinct enough to have an effect on clinical outcome of patients. LEVEL OF EVIDENCE: Therapeutic study, Level III. Show less
