Arthroplasty最新文献

Background: Enhanced Recovery After Surgery (ERAS) was introduced in hip and knee arthroplasty to expedite recovery, shorten inpatient stay, and reduce costs. This study aims to investigate the safety and efficacy of implementing a universal standardized non-selective ERAS service for all patients admitted for primary hip and knee arthroplasty in a single high-volume tertiary orthopaedic centre.

Methods: All patients who underwent primary hip or knee arthroplasty under ERAS from April 2023 to March 2024 were compared with a matched cohort between January 2018 and December 2019. Patients were matched at a 2:1 ratio based on procedure, age, sex, ASA grade, and BMI (ERAS = 1811, Standard Care = 3549 patients). Outcomes included Length of Stay (LOS), 30-day readmission, overall infection, superficial infection, deep infection, 30- and 90-day mortality rates.

Results: The median LOS was 1 day (IQR 1-2) in the ERAS group versus 3 days (IQR 2-4) in the Standard Care group (W = 5,415,769, P < 0.001). Rates of 30-day readmission (1.7% vs. 2.1%), overall infection (0.66% vs. 1.15%), deep infection (0.39% vs. 0.68%), superficial infection (0.28% vs. 0.48%), 30-day mortality (0.11% vs. 0.20%), and 90-day mortality (0.22% vs. 0.37%) were all higher in the Standard Care group. However, these differences were not statistically significant, with P-values of 0.41, 0.11, 0.26, 0.38, 0.70, and 0.52, respectively. The estimated cost reduction per patient with the ERAS pathway, considering only the difference in LOS, is £718.60(95%CI £602.56 to £832.64). The subgroup analysis for patients ≥ 80 revealed a statistically significant difference in LOS, which was more pronounced with a median difference of 3 days (5 days in standard care versus 2 days in ERAS, P < 0.001).

Conclusion: Non-selective ERAS was safe and effective in reducing LOS for patients undergoing primary THA and TKA across all age groups and varying comorbidity statuses. Although perioperative morbidity and mortality were less in ERAS, these changes did not reach statistical significance.

Background: Precise acetabular cup positioning is critical for the success and longevity of total hip arthroplasty (THA). Robotic-assisted systems enhance placement accuracy, with closed-platform systems being well-established. A pertinent question is whether newer open-platform systems, which offer implant flexibility, achieve comparable accuracy. This study evaluates the radiographic accuracy of a novel, open-platform robotic system (Yuanhua KUNWU) in achieving the planned acetabular component position.

Methods: A multi-centre retrospective review of 87 consecutive primary robotic THA procedures performed using the KUNWU system was conducted. Pre-operative CT-based planning defined the target acetabular inclination (AI) and anteversion (AV). The primary outcome was the deviation between the planned position and the post-operative CT-measured position. Secondary outcomes included the proportion of cups within the Lewinnek and Callanan safe zones and the accuracy of leg length and offset restoration.

Results: The mean deviation from the planned position to the post-operative CT was -2.7° for inclination (95% CI: -3.7° to -1.8°, P < 0.001) and 1.0° for anteversion (P = 0.058). Overall, 80.5% (70/87) of cups were placed within the combined Lewinnek and Callanan safe zones. A significant difference was found in combined offset (mean 2.79 mm, P = 0.002) but not in leg length discrepancy (P = 0.302). Interobserver reliability was excellent for all measurements.

Conclusion: The KUNWU open-platform robotic system facilitates accurate and reliable acetabular cup positioning, with minimal deviations from the pre-operative plan and a high rate of placement within the classic safe zones. These results support its use as a precise tool for component positioning in THA.

Background: The survival rate after surgical osteosarcoma resection is low, particularly when the sarcoma is not fully removed. Therefore, wide surgical margins are used in surgery, limiting how much bone can be salvaged. Patient-specific instrumentation (PSI) enables smaller margins, but utilization is low. Mixed reality-based techniques (MR) might be easier to implement. The purpose of this study was to compare the cutting accuracy of MR, PSI, and freehand techniques in 3D-printed osteosarcoma models and determine the corresponding technique-related minimal surgical margins.

Methods: CT-scans of patients with extremity osteosarcoma were acquired, segmented, and the bones 3D-printed three times. Scans were excluded if they had low resolution or metal artifacts. Pre-surgical planning for full resection was conducted, and corresponding PSI and MR plans were created. Tumor resections were separately done via a freehand, PSI, and MR approach. Resected bone models were 3D scanned, and the cutting accuracy was determined. Differences in accuracy were determined via Bartlett's test and corresponding post-hoc tests for a significance level of 0.05. The techniques' surgical margins were determined for 90, 95, 97.5, and 99% successful cuts.

Results: Ten osteosarcomas with one to three cutting planes were included, leading to a total of 19 cuts. The variance in cut accuracy was significantly greater for the freehand approach (standard deviation (STD) [95%CI]: 6.85 [5.18-10.13] mm) than the MR (STD: 3.71 [2.79-5.57] mm) and the PSI (STD: 2.68 [2.02-3.96] mm) approach. No significant difference in variance between PSI and MR was found (P = 0.44). Surgical margins varied between techniques, with the freehand approach being about twice those of the MR and PSI approaches. To achieve 99% tumor-free cuts, the estimated required margins were 15.9 mm (freehand), 6.2 mm (PSI), and 8.6 mm (MR).

Conclusion: This study acts as a non-clinical proof of concept that the adoption of patient-specific instrumentation or mixed reality techniques for osteosarcoma resection might enable narrower margins pending in-vivo validation, potentially enabling bone and joint preservation and restoration, while decreasing resection failure rates.

Background: Total joint arthroplasty (TJA) complications necessitate the development of accurate risk prediction models; however, interpretability in machine learning remains a challenge. While Shapley Additive Explanations (SHAP) offers insights at the individual level, partial dependence plots (PDPs) may provide a better understanding at the population level for developing clinical guidelines. This study compared PDPs and SHAP in explaining machine learning-based 30-day complication risk prediction following TJA.

Methods: We conducted a retrospective cohort study using the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database (2019-2023), including 517,826 primary TJA cases. Binary classification models (Random Forest, Gradient Boosting) predicted composite 30-day complications based on 20 clinical predictors. A comprehensive interpretability analysis employed directional concordance validation between PDP and SHAP, permutation importance thresholding (5% relative influence), followed by one- and two-dimensional partial dependence analyses with explicit interaction modeling.

Results: The cohort comprised 517,826 primary TJA procedures with a complication rate of 6.67%. The baseline Random Forest model achieved test AUC = 0.678. Directional concordance analysis demonstrated 97.8% weighted agreement between PDP trends and SHAP attributions, validating methodological comparison. Threshold analysis identified seven significant features, with interaction effects accounting for 49.9% of total model influence (71.9% among top features). PDPs showed actionable dose-response relationships, including critical thresholds for preoperative hematocrit (< 38%), operative time (> 120 min), and complementary interactions, such as age × ASA classification (19.1% importance), operative time × ASA classification (10.1%), and hematocrit × diabetes (6.4%). Comparative patient analysis demonstrated that while SHAP quantified individual contributions, only PDPs provided population thresholds directly translatable to institutional protocols.

Conclusion: PDPs appear more methodologically appropriate than SHAP for population-level clinical guideline development, offering actionable dose-response relationships and population risk thresholds that SHAP's individualized attribution framework cannot provide. The dominance of interaction effects among the most influential predictors validates that PDPs accurately capture complementary relationships while presenting them in a format directly applicable to evidence-based perioperative protocols and institutional quality improvement initiatives. Video Abstract.

Background: Periprosthetic joint infection (PJI) remains a major diagnostic challenge, and no single biomarker provides definitive accuracy. With rapid advances in synovial, serum, and molecular assays, a comprehensive overview of global biomarker research is needed. This study provides a broad, data-driven mapping of PJI biomarker research, clarifying major thematic shifts and their implications for clinical translation.

Methods: A literature search of the Web of Science Core Collection (2011-2024) identified research and review articles on PJI diagnostics and biomarkers. Bibliometric indicators, collaboration networks, and keyword co-occurrence were analyzed using VOSviewer, CiteSpace, and Bibliometrix. Co-citation and keyword analyses were used to determine influential references and evolving hotspots. Recent high-impact studies and consensus guidelines were reviewed to contextualize the findings.

Results: PJI biomarker publications increased markedly, rising from fewer than five per year before 2014 to 57 in 2020. The 380 papers included accumulated more than 5,200 citations (mean 13.8 per article). China (103) and the USA (88) accounted for half of all output, with the USA showing the strongest citation impact; Germany, the UK, and Italy were also key contributors. Collaboration mapping highlighted Parvizi, Trampuz, and the Rothman Institute as central nodes. The Journal of Arthroplasty published the largest share of studies, while JBJS-Am and CORR had the highest citations per article. Keyword evolution showed a transition from conventional serum markers (2011-2015) to synovial α-defensin and leukocyte esterase assays (2016-2018), and more recently to synovial calprotectin, machine learning, microfluidics, and molecular diagnostics (2019-2024).

Conclusion: From 2011 to 2024, PJI biomarker research grew rapidly, driven mainly by institutions in the United States, China, and Europe. Key themes included synovial α-defensin, calprotectin, machine learning, and next-generation sequencing. Future progress depends on multicenter validation, assay standardization, and integrating biomarkers into diagnostic algorithms. Stronger collaboration, data sharing, and decision-support tools will be essential for earlier and more accurate PJI diagnosis. Video Abstract.

Background: Although favorable survival and good outcomes have been reported with Oxford unicompartmental knee arthroplasty (UKA), the effect of perioperative alignment change on patient-reported outcome measures (PROMs) remains controversial. In this study, we investigated the impact on outcomes and survivorship of medial UKA with significant perioperative alignment changes.

Methods: We retrospectively reviewed 316 patients with anteromedial OA who underwent primary Oxford UKA. The patients were divided into three groups (A, n = 146; B, n = 98; C, n = 72), Group A: mild varus alignment change (≤ 4°), Group B: moderate varus alignment change (> 4° and < 7°) and Group C: large varus alignment change (≥ 7°). The mean follow-up period was 2.9 years (range: 1.9-4.5 years). Patient history, as well as pre- and post-operative KOOS-JR (Knee Injury and Osteoarthritis Outcome Score for Joint Replacement) scores and Kujala scores, were obtained through chart review. Continuous data were compared using analysis of variance (ANOVA). Chi-squared tests were used to compare discrete variables. Linear regression was conducted to estimate the effect of alignment change on the improvement of the KOOS-JR score.

Results: In all groups, the KOOS-JR and Kujala scores showed significant improvement after surgery. At the 1-month follow-up, the difference in mean KOOS-JR score between the groups was not significant (P > 0.05). The Kujala score of Group A was highest (P < 0.05), and the difference between Group B and C was not significant (P > 0.05). In the 2-year follow-up, mean KOOS-JR and Kujala outcomes were comparable among groups (P > 0.05). The KOOS-JR MCID in each group was 71% in Group A, 73% in Group B, and 85% in Group C. Linear regressions showed no statistically significant relationship between the variation of perioperative alignment and KOOS-JR scores (P > 0.05). The 2-year survival rate for the entire cohort was 100%.

Conclusion: UKA with a low angle of perioperative varus deformity change would have a rapid improvement of functional scores, especially the relief of anterior knee pain. Severe varus deformity with large perioperative alignment change can still obtain desirable outcomes. Video Abstract.

Background: Conversion to total hip arthroplasty (THA) is associated with higher rates of infection. The purpose of this study is to determine whether applying the surgical technique of single-stage revision can effectively reduce the infection rate of conversion THA after failed femoral neck fractures.

Methods: A retrospective cohort study was conducted on patients who underwent conversion THA after failed femoral neck fracture between January 2019 and December 2022, with a minimum follow-up of 2 years. From January 2019 to March 2020, patients undergoing conversion THA were managed as a primary procedure without synovial fluid culture (Group A). From April 2020 to December 2022, patients undergoing conversion THA were managed with the single-stage revision technique and routine intraoperative synovial fluid culture (Group B). The patients in Group B were matched 1:1 to patients in Group A. Unexpected positive intraoperative culture (UPIC) results were recorded, and PJIs were monitored during the minimum 2-year follow-up period.

Results: As intraoperative cultures were only performed in Group B, the unexpected positive intraoperative culture (UPIC) results presented were solely for Group B. Among the patients in Group B who underwent conversion THA, 91% had no UPIC (90 of 99), 7% had a single (either anaerobic bottle or aerobic bottle) UPIC (7 of 99), and 2% had two (both anaerobic and aerobic bottles) UPICs (2 of 99). In Group A, 7 patients (7/99, 7%) experienced PJIs, compared to 1 patient (1/99, 1%) in Group B, showing a significant difference between the two groups (P = 0.030).

Conclusion: As a novel method for conversion to THA after failed femoral neck fracture, the single-stage revision technique is potentially associated with a lower incidence of PJI. Further evaluation of this technique in larger comparative series is warranted. Video Abstract.

Introduction: Periprosthetic joint infections (PJI) pose significant clinical challenges due to biofilm formation and antibiotic resistance. Standard treatment often involves implant removal and prolonged antibiotic therapy. Novel strategies target intracellular pathogens and biofilm-associated bacteria, including liposomal antibiotics, antimicrobial peptides, and bacteriophage therapy. Bacteriophages offer specificity and minimal disruption to human microbiota but remain experimental in PJI. Combining phages with targeted antibiotics shows promising results in preclinical models, though further research is needed to confirm efficacy in human PJI and optimise delivery methods.

Objectives: This study updates the current evidence on the use of bacteriophages for patients with PJI, proposing guidelines for their clinical application.

Method: PubMed was searched for articles containing phage therapy in revision arthroplasty. No additional filters or time constraints were used. All eligible studies were accessed by hand.

Results: A total of 39 studies (20 clinical, 19 reviews) on phage therapy for PJI were analysed, covering 56 patients. Of those, negative outcomes were only reported in five. Most studies involved elderly patients with periprosthetic infections of the knee or hip and showed high success rates when combined with antibiotics and surgery. Phage therapy was well tolerated, with only mild adverse effects, such as fever and reversible transaminitis, occurring predominantly with intravenous administration. Review articles reveal that despite promising outcomes, challenges remain, including a lack of standardisation, limited clinical data, and regulatory hurdles.

Conclusion: This study highlights the potential of phage therapy for PJI, emphasising its high specificity, ability to target antibiotic-resistant bacteria, and capacity to disrupt biofilms, and provides a guideline for its clinical administration. Clinical adoption, however, remains limited by regulatory barriers, lack of standardised protocols, and insufficient trial data. Key steps for implementation include establishing regulatory frameworks, developing academic-industrial partnerships and reference centres, and identifying indications supported by controlled trials. With these in place, phage therapy could become a promising adjunct in managing periprosthetic joint infections. Video Abstract.

Background: Accurate femoral component alignment in the sagittal plane is crucial for total knee arthroplasty (TKA) success. In manual TKA, sagittal alignment is typically guided by the intramedullary axis (IMA) determined on lateral radiographs. However, due to femoral bowing, the IMA varies along the femoral shaft, raising the question of the optimal level for referencing this axis. As short-segmented knee radiographs (SSKR) are increasingly used in clinical practice, it is unclear whether they introduce systemic deviations in IMA determination. This study aimed to compare the IMA derived from SSKR and conventional lateral radiographs (CLR), and to assess whether axis deviation increases with femoral shaft length.

Methods: This retrospective analysis included 153 patients undergoing primary TKA. The femoral IMA was determined using a two-circle method on both the full CLR and a 12.5 cm distal segment simulating SSKR. For the CLR axis, one circle was positioned at the most proximal point of the femoral shaft visible on the radiograph, and the second circle was placed 5 cm proximal to the distal femoral joint line. For the SSKR-based axis, the distal circle remained identical, while the proximal circle was repositioned 12.5 cm proximal to the joint line. Measurements were performed twice by two observers. The angular deviation between CLR- and SSKR-based axes was reported in degrees. A one-sample t-test was used to test for statistical significance. Clinically relevant deviation was defined as ≥ 2°, and the number and percentage of such outlier cases were reported. Correlation between femoral shaft length and angular deviation was analyzed using Pearson correlation. A multivariable regression tested whether femoral length independently predicted angular deviation after adjusting for age, sex, BMI, and side.

Results: The IMA on SSKR was significantly more posterior than on CLR, with a mean angular deviation of 2.3° ± 1.1° (95% CI: 2.2-2.5; P < 0.001; Cohen's d = 2.1). In 57 cases (38%), deviation exceeded the clinically relevant threshold of ≥ 2°. A significant positive correlation was found between the visible femoral shaft length and the angular deviation between CLR and SSKR axes (r = 0.504, P < 0.001). In multivariable regression, femoral length remained an independent predictor of angular deviation after adjustment for age, sex, BMI, and side (P < 0.001).

Conclusion: Referencing the IMA on SSKR results in a significantly more posterior axis compared to CLR, which may lead to increased femoral component flexion in TKA. Given the high incidence of outlier cases and their association with femoral shaft length, surgeons should be cautious when relying on short radiographs for preoperative planning of sagittal femoral alignment. Video Abstract.

Purpose: To evaluate the accuracy of two-dimensional (2D) digital templating in primary total knee arthroplasty (TKA) and assess whether surgical training level affects templating accuracy.

Methods: A total of 424 patients who underwent primary TKA with preoperative 2D digital templating using the Attune system were retrospectively analyzed. Templating was performed in TraumaCad (Brainlab AG) by junior residents (< 3 years of training), senior residents (≥ 3 years), or board-certified orthopaedic surgeons. Planned and implanted component sizes were compared, and accuracy was assessed as exact matches and deviations of ± 1, ± 2, and ± 3 sizes. Pearson correlation analysis was used to assess the association between planned and implanted sizes. One-way ANOVA was used to compare mean absolute deviation across training levels. Additionally, the proportion of cases with a deviation greater than ± 1 size was calculated for both components across experience levels and compared using chi-square tests.

Results: A total of 424 patients (61% female) were included. The median planned component sizes were 6 (IQR, 5-7) for the femoral and 6 (IQR, 5-7) for the tibial component; the median implanted sizes were 6 (IQR, 5-7) and 6 (IQR, 4-7), respectively. Planned and implanted sizes were very strongly correlated for both femoral (r = 0.864; P < 0.001) and tibial components (r = 0.841; P < 0.001). Templating accuracy was high, with 92.7% of femoral and 88.7% of tibial components within ± 1 size. No significant differences in correlation strength or mean absolute deviation were observed across training levels (P > 0.05). The proportion of cases with > ± 1 size deviation was low across all groups and did not differ significantly between training levels for either component (femoral: P = 0.874; tibial: P = 0.791).

Conclusion: 2D digital templating for primary TKA demonstrated high accuracy, with reliable prediction within a ± 1 size range and no significant influence of surgical training level. These findings support its continued clinical use and confirm that templating can be reliably performed by residents at all stages of training. Video Abstract LEVEL OF EVIDENCE: Level III, diagnostic study.