Accurate component placement plays a critical role in the outcome of total hip arthroplasty (THA). Robotic-assisted THA (R-THA) has emerged as an option to optimize this aspect compared to the conventional manual THA (C-THA). The aim of this meta-analysis was to analyze the studies comparing R-THA and C-THA. The hypothesis was that the use of robotic technology could improve component positioning, but this advantage may not translate into clinically relevant benefits. The literature search was conducted on three databases (PubMed, Cochrane Library, and Web of Science) in January 2024. The screening process and analysis were conducted separately by two independent observers according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The inclusion criteria were comparative studies, English language, no time limitation, and focusing on the comparison of R-THA and C-THA. Among the 1,883 articles retrieved, 38 studies (10,055 patients) were included. The meta-analysis covered radiological outcomes, clinical outcomes, perioperative parameters, complications, and revisions. The quality of each article was assessed using the "Downs and Black's checklist for measuring quality". Robotic THA provided superior radiological results compared to C-THA in terms of acetabular cup placement within the Lewinnek safe zone (P < 0.01) and horizontal change of the rotation center (P = 0.03). No statistically significant difference was obtained in terms of clinical scores between the two approaches, including Harris Hip Score, Western Ontario and McMaster Universities Arthritis Index, Forgotten Joint Score, and Merle d'Aubigné Hip Score. Robotic THA showed longer operative time (P < 0.01), but lower complication rates (P = 0.04). No difference was obtained in terms of intraoperative blood loss and revision rates. The results of this meta-analysis suggest that R-THA can provide more accurate cup placement and better restoration of the native hip anatomy while reducing complication rates compared to C-THA. However, these benefits did not translate into clinical differences in terms of patient-reported outcomes between the two approaches, and R-THA required longer operative time. While the overall results suggest some benefits with the robotic technology, future studies should investigate if further technical improvements will translate into clinically relevant benefits for patients undergoing THA.

Aims: Robotic-assisted unicompartmental knee arthroplasty (R-UKA) has been proposed as an approach to improve the results of the conventional manual UKA (C-UKA). The aim of this meta-analysis was to analyze the studies comparing R-UKA and C-UKA in terms of clinical outcomes, radiological results, operating time, complications, and revisions.Methods: The literature search was conducted on three databases (PubMed, Cochrane, and Web of Science) on 20 February 2024 according to the guidelines for Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). Inclusion criteria were comparative studies, written in the English language, with no time limitations, on the comparison of R-UKA and C-UKA. The quality of each article was assessed using the Downs and Black Checklist for Measuring Quality.Results: Among the 3,669 articles retrieved, 21 studies on 19 series of patients were included. A total of 3,074 patients (59.5% female and 40.5% male; mean age 65.2 years (SD 3.9); mean BMI 27.4 kg/m² (SD 2.2)) were analyzed. R-UKA obtained a superior Knee Society Score improvement compared to C-UKA (mean difference (MD) 4.9; p < 0.001) and better Forgotten Joint Score postoperative values (MD 5.5; p = 0.032). The analysis of radiological outcomes did not find a statistically significant difference between the two approaches. R-UKA showed longer operating time (MD 15.6; p < 0.001), but reduced complication and revision rates compared to C-UKA (5.2% vs 10.1% and 4.1% vs 7.2%, respectively).Conclusion: This meta-analysis showed that the robotic approach for UKA provided a significant improvement in functional outcomes compared to the conventional manual technique. R-UKA showed similar radiological results and longer operating time, but reduced complication and revision rates compared to C-UKA. Overall, R-UKA seems to provide relevant benefits over C-UKA in the management of patients undergoing UKA.Cite this article: Bone Jt Open 2024;5(5):374–384.

This systematic review and meta-analysis of randomized controlled trials (RCTs) aimed at comparing resurfacing hip arthroplasty (RHA) and total hip arthroplasty (THA) in terms of rate of complications, revisions, functional outcomes, blood loss, operative time and metal ions levels. The search was conducted on three databases (PubMed, Cochrane and Web of Science) updated until 13 October 2022. The inclusion criteria were RCTs) written in the English language, with no time limitation, comparing RHA and THA. Among the retrieved 4748 articles, 18 RCTs were eligible for a total of 776 patients (mean age 53.1 ± 5.0). A meta-analysis was performed. RHA reported significantly lower blood loss compared to THA (p < 0.001) but with longer operative time (p < 0.001). No statistically significant difference was found between RHA and THA in terms of complications (12.08% and 16.24%, respectively) and revisions (6.32% and 6.14%, respectively). Both RHA and THA provide excellent clinical results in a population of young and active patients. Functional outcomes were not significantly different between the groups. Moreover, no significant difference in metal ion levels was found. These findings provide evidence concerning the safety and clinical effectiveness of RHA. Because of its bone-preserving properties, the lack of drawbacks and good outcomes, RHA appears to be a valid alternative to THA in young and active patients.

Purpose: Multiple clinical factors may concur to determine the clinical trajectory leading towards total knee arthroplasty (TKA) in patients affected by knee osteoarthritis (OA). The aim of this study was to identify the main factors influencing progression to TKA in a large population of knee OA patients. Methods: A total of 7552 knees were selected from the Osteoarthritis Initiative (OAI) multicentre database. The data collected included demographic data, Kellgren–Lawrence (KL) grade, the presence of knee swelling, the frequency of swelling, visual analogue scale (VAS) for pain, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee Injury and Osteoarthritis Outcome Score (KOOS) and the number of knees requiring TKA. The baseline data were collected as reported by the OAI database, and patients were followed up at 12, 24, 36, 48, 60, 72, 84 and 96 months, documenting whether they underwent TKA during this period. Results: A multivariable analysis was performed to identify factors independently influencing progression to TKA. At 96 months, 7.1% of knees underwent TKA. The progression to TKA correlated with age ( p < 0.001), KL grade ( p < 0.001), swelling frequency ( p < 0.001), knee swelling ( p < 0.001), VAS ( p = 0.003) and KOOS ( p < 0.001). Knees with KL Grades 3 and 4 had the same risk of undergoing this procedure, while the need for TKA was able to be predicted based on WOMAC pain ( p = 0.035, hazard ratio [HR] = 0.864), VAS ( p = 0.008, HR = 1.131) and KOOS ( p = 0.02, HR = 0.966). Conclusions: This study revealed that several factors influenced progression to TKA, including age, KL grade, knee swelling, VAS pain and KOOS. However, there was no statistically significant difference between KL 3 and KL 4 in predicting the disease trajectory, and patients' clinical symptoms, as quantified by WOMAC pain subscale, VAS and KOOS, had a greater influence on progression to TKA than knee KL OA severity. Level of Evidence: Level IIb.

Purpose: The aim was to compare the safety profiles of corticosteroids (CS), hyaluronic acid (HA), blood‐derived products based on platelet concentrates (for simplicity indicated as PRP ‐ platelet‐rich plasma ‐ being PRP the most common product), and cell‐based therapies (namely products exploiting the therapeutic function of mesenchymal stromal cells and other cell populations, either expanded or prepared at the point of care) for knee osteoarthritis (OA) injective treatment. Methods: The literature search was conducted on PubMed, Cochrane, and Web of Science according to PRISMA guidelines on clinical studies reporting adverse events of CS, HA, PRP, or cell‐based therapies. Number of patients with adverse events and number and type of adverse events were collected for each treatment. A meta‐analysis was conducted for each product on the total, non‐severe, severe adverse events, and on the infection rate. Results: Out of 848 included studies, 559 reported data on the adverse events in 76,061 patients and were used for the meta‐analysis. These studies included 7121 patients treated with CS, 51,146 patients with HA, 11,941 patients with PRP, and 5853 patients with cell‐based therapies. The rates of patients reporting at least one adverse event were 11.0% for CS, 10.5% for HA, 8.7% for PRP, and 14.7% for cell‐based therapies. The mean number of total adverse events per treated patient was 0.21 for CS, 0.13 for HA, 0.05 for PRP, and 0.19 for cell‐based therapies, with a significant difference in each individual comparison ( p < 0.001) except for CS versus cell‐based therapies. The same trend was observed for non‐severe adverse events. The rates of severe adverse events were 1.1% for CS, 0.7% for HA, 0.3% for PRP, and 0.5% for cell‐based therapies, while infection rates were 0.4% for CS, 0.1% for HA, 0.3% for PRP, and 0.4% for cell‐based therapies. Conclusion: CS, HA, PRP, and cell‐based therapies for knee OA have different safety profiles. PRP presented the lowest total adverse event rate, followed by HA, cell‐based therapies, and CS. The same trend was observed for non‐severe adverse events. PRP demonstrated the lowest rate of severe adverse events, followed by cell‐based therapies, HA, and CS, while HA showed the lowest infection rate followed by PRP, CS, and cell‐based therapies. Level of Evidence: Level IV.