Acta Orthopaedica最新文献

Background and purpose: Temporary hemiepiphysiodesis by tension-band devices is commonly applied to correct angular limb deformities in children. We aimed to evaluate knee joint morphology after guided growth using these devices.

Patients and methods: In a retrospective multicenter study we analyzed standardized anteroposterior long-leg radiographs of 222 limbs (285 implants) of patients treated by temporary hemiepiphysiodesis with either eight-Plates or FlexTacks for coronal angular deformities of the knee joint between 2013 and 2019. Femoral floor angle (FFA), femoral notch-intercondylar distance (FNID), and tibial roof angle (TRA) were measured pre- and postoperatively to assess the central knee joint morphology. Statistical exploratory analyses were performed using linear mixed models, t-tests, Wilcoxon signed-rank test, and Mann-Whitney U test.

Results: 217 FlexTacks (femur 106, tibia 111) in 104 children and 68 eight-Plates (femur 61, tibia 7) in 35 children were identified. Median time period under growth guidance was 11 months (range 4-42). No statistically significant change in the FFA was detected (eight-Plate: P = 0.2; FlexTack: P = 0.3). A statistically significant difference of the FNID was found in the eight-Plate group (P = 0.02), but not in the FlexTack group (P = 0.3). While TRA increased in both groups, a statistical significance was observed only in the FlexTack group (P < 0.01).

Conclusion: We found minor but clinically irrelevant changes in knee morphology after the treatment.

Background and purpose: There is inconsistency in the literature regarding the relationship between increased birthweight and risk of developmental dysplasia of the hip (DDH). We aimed to investigate the correlation between birthweight and pubo-femoral distance (PFD), as well as Graf's α angle in newborns undergoing hip ultrasound examination at 6 weeks of age.

Patients and methods: Basic newborn characteristics and ultrasound measurements were retrospectively collected during a 1-year study period. We excluded multiple births, newborns born at less than 37 gestational weeks, and incomplete information. Simple and multiple linear regression analyses were performed to evaluate the correlation of birthweight and PFD, and, second, birthweight and α angles including a stratified regression analysis investigating the potential effect modification of sex.

Results: 707 newborns (1,414 hips) were included. Mean birthweight was significantly higher for male newborns (P < 0.001). Increased birthweight was positively correlated to PFD values (crude coefficient 0.21, 95% confidence interval [CI] 0.10-0.32) and the correlation was still present after adjusting for sex, family history, and breech presentation (adjusted coefficient 0.18, CI 0.07-0.29). The stratified α angle model for the males was significant for both the crude coefficient (-0.73, CI -1.28 to -0.19) and the adjusted (-0.59, CI -1.15 to -0.03), and also for the females (crude coefficient -1.14, CI -1.98 to -0.31 and adjusted coefficient -1.15, CI -1.99 to -0.31).

Conclusion: We found that increased birthweight positively correlated to PFD, and negatively correlated to α angle, but this was not of clinical significance.

Background and purpose: While registry studies have suggested a higher risk of revision for posterior-stabilized (PS) compared with posterior cruciate-retaining (CR) total knee replacements (TKR) using cement, it is unknown whether this is also the case for uncemented TKR. We aimed to compare the revision rates of PS and CR designs in patients receiving primary uncemented TKR.

Patients and methods: Data from the Dutch arthroplasty register (LROI) was analyzed, comprising 12,226 uncemented primary CR TKRs and 750 uncemented PS TKRs registered between 2007 and 2022. Competing risk and multivariable Cox regression analyses were used to compare revision rates, risks of revision, and reasons for revision between groups. Sensitivity analyses were performed to analyze the risk, concerning the 5 most commonly used implants and performing hospitals for each group.

Results: Uncemented PS TKRs had higher 10-year revision rates for any reason and aseptic loosening (6.5%, 95% confidence interval [CI] 4.6-9.2 and 3.9%, CI 2.6-6.7) compared with uncemented CR TKRs (4.2%, CI 3.8-4.7 and 1.4%, CI 1.2-1.7). PS TKRs were 1.4 and 2.5 times more likely to be revised for any reason and aseptic loosening, respectively. These results remained consistent after adjustment for age, sex, BMI, previous surgeries, bearing mobility, and surface modification, with sensitivity analyses.

Conclusion: We found that uncemented PS implants have a higher rate of revision than uncemented CR implants, mainly due to a higher risk of aseptic loosening.

When we checked our data in our article "Similar outcome with a new anteverted or a straight standard stem: a randomized study of 72 total hip arthroplasties evaluated with clinical variables, radiostereometry, and DXA up to 2 years" by Karin Rilby, Maziar Mohaddes, Emma Nauclér, and Johan Kärrholm, Acta Orthop 2021; 92, Published online October 21, 2021 we noticed that the numbers in Table 7 (Supplementary data) were incorrect. We have not been able to fully reconstruct the reason for this error. We are sorry for this mistake. Even if the corrected numbers are different the overall conclusions will be same and also the statistical significances.

Background and purpose: The low radiation biplanar X-ray imager (EOS imaging, Paris, France) scans patients in a weight-bearing position, provides calibrated images, and limits radiation, an asset for serial radiostereometric analysis (RSA) studies. RSA in vivo precision values have not been published for this type of imaging system, thus the goal of this study was to assess the precision of RSA in vivo utilizing a low radiation biplanar imager.

Patients and methods: At a mean of 5 years post-surgery (range 1.4-7.5 years), 15 total knee arthroplasty (TKA) participants (mean age 67 years at the time of imaging, 12 female, 3 male) with RSA markers implanted during index surgery were scanned twice at the same visit in the EOS imager. Precision of marker-based analysis was calculated by comparing the position of the implant relative to the underlying bone between the 2 examinations.

Results: The 95% limit of precision was 0.11, 0.04, and 0.15 mm along the x, y, and z axes, respectively and 0.15°, 0.20°, and 0.14° around the same axes.

Conclusion: This precision study has shown an in vivo RSA precision of ≤ 0.15 mm and ≤ 0.20°, well within published uniplanar values for conventional arthroplasty RSA, with the added benefit of weight-bearing imaging, a lower radiation dose, and without the need for a reference object during the scan.

Background and purpose: Concerns exist regarding the generalizability of results from randomized controlled trials (RCTs) evaluating arthroscopic partial meniscectomy (APM) to treat degenerative meniscus tears. It has been suggested that study populations are not representative of subjects selected for surgery in daily clinical practice. Therefore, we aimed to compare patients included in trials and prospective cohort studies that received APM for a degenerative meniscus tear.

Patients and methods: Individual participant data from 4 RCTs and 2 cohort studies undergoing APM were collected. 1,970 patients were analyzed: 605 patients included in RCTs and 1,365 included in the cohorts. We compared patient and disease characteristics, knee pain, overall knee function, and health-related quality of life at baseline between the RCT and cohort groups using standardized differences, ratios comparing the variance of continuous covariates, and graphical methods such as quantile-quantile plots, side-by-side boxplots, and non-parametric density plots.

Results: Differences between RCT and the cohort were observed primarily in age (younger patients in the cohort; standardized difference: 0.32) and disease severity, with the RCT group having more severe symptoms (standardized difference: 0.38). While knee pain, overall knee function, and quality of life generally showed minimal differences between the 2 groups, it is noteworthy that the largest observed difference was in knee pain, where the cohort group scored 7 points worse (95% confidence interval 5-9, standardized difference: 0.29).

Conclusion: Patients in RCTs were largely representative of those in cohort studies regarding baseline scores, though variations in age and disease severity were observed. Younger patients with less severe osteoarthritis were more common in the cohort; however, trial participants still appear to be broadly representative of the target population.

Background and purpose: This updated meta-analysis evaluates the migration pattern of the tibial component of primary total knee replacements measured with radiostereometric analysis (RSA). We aimed to evaluate whether 6-month maximum total point motion (MTPM) values could be used instead of 1-year MTPM for RSA threshold testing and to present the pooled migration patterns for different implant designs that can be used as a benchmark.

Patients and methods: The search included all published RSA studies on migration patterns of tibial components until 2023. Study groups were classified according to their prosthesis brand, fixation, and insert (PFI). Sub-analyses were performed to compare the mean tibial component migration patterns of different implant variables, stratified according to fixation.

Results: 96 studies (43 new studies), including 197 study groups and 4,706 knees, were included. Most migration occurred within the first 6 postoperative months (126 study groups: mean 0.58 mm, 95% confidence interval [CI] 0.50-0.65), followed by minimal migration between 6 and 12 months (197 study groups: mean 0.04 mm, CI 0.03-0.06), irrespective of the fixation method used. Distinct migration patterns were observed among the different fixation methods. No differences were found in migration patterns among cemented components in any of the sub-group analyses conducted. For uncemented implants, trabecular metal surfaced components seemed to migrate less than porous-coated or uncoated components Conclusion: Based on the small difference between MTPM values at 6 months and 1 year, MTPM at 6 months could be used instead of MTPM at 1 year for RSA threshold testing. The pooled migration patterns can be used as benchmark for evaluation of new implants by defining fixation-specific RSA thresholds when combined with implant survival.

Background and purpose: Despite usage of the ATTUNE total knee arthroplasty (TKA) for about 10 years, few randomized trials exist. We evaluated whether the ATTUNE CR design showed improved clinical results compared with the PFC Sigma CR after 2 years and if there was a difference in tibial component migration.

Patients and methods: 96 patients with knee osteoarthritis were randomly treated with cemented ATTUNE or PFC Sigma TKA. 42 patients with the ATTUNE and 48 with the PFC Sigma attended the 2-year follow-up. Patient-reported outcome measurements (PROMs), migration measured with RSA, implant position, and the development of radiolucent zones were studied. Non-parametric tests and repeated measures analysis were used at the statistical evaluation.

Results: The Oxford Knee Score (OKS) at 2 years (primary outcome) and neither of the secondary PROM outcomes differed between the groups (mean difference OKS ATTUNE - PFC: -0.08, 95% confidence interval [CI] -2.9 to 2.7). RSA showed posterior tilt of the tibial component in the ATTUNE group with proximal lift-off anteriorly and subsidence of the tibial tray posteriorly. In contrast, the PFC Sigma tibial component tilted forward (mean difference ATTUNE - PFC: -0.7°, CI -1.1° to -0.4°) with maximum subsidence in the front and maximum lift-off of the posterior edge. The postoperative implant positions and the extension of radiolucent lines around the tibial component at 2 years did not differ.

Conclusion: We found no significant differences in clinical outcome between the 2 groups but minor differences in migration pattern of the tibial component. The clinical long-term significance of this finding if any is not known.