Cartilage is an important yet vulnerable tissue with limited self-healing capacity, where damage often progresses to joint degeneration, which eventually leads to severe osteoarthritis (OA). Current tissue engineering strategies focus on biocompatible scaffolds for cartilage regeneration, particularly amnion (or amniotic membrane), emerging as a promising biomaterial due to its wide availability, low immunogenicity, and naturally derived microenvironment that is advantageous for cartilage regeneration. This systematic review aims to evaluate the existing evidence on the efficacy of amnion as a tissue scaffolding material for cartilage regeneration in both preclinical and clinical studies. Using terms such as “cartilage damage”, “cartilage injuries”, “amnion” and “amniotic membrane”, 19 relevant studies were identified across three major databases (PubMed, Scopus and Web of Science) until 25 December 2025. All preclinical and clinical studies that utilized amnion for cartilage repair or as cartilage tissue engineering scaffolding materials were included. Evidence quality was assessed using the OHAT and MINORS risk of bias tool. This study is prospectively registered in the PROSPERO database under the ID 1178444. The findings consistently indicate that amniotic scaffolds, regardless of processing methods or cell seeding, yield favorable outcomes without adverse effects across different species. In vitro analysis revealed that treatment groups with amnion show better cell attachment, viability, and proliferation, and higher content of cartilage-related markers expressed by the seeded cells, either chondrocyte, bone marrow-derived mesenchymal stem cells (MSCs), adipose tissue-derived MSCs, placenta-derived MSCs, umbilical cord-derived MSCs, amniotic MSCs or amniotic epithelial cells. In in vivo and ex vivo studies, amnion-treated groups demonstrated improved quality of the treated cartilage, with better integration, as indicated by higher histological scores and the presence of type II collagen (COL-II). There was an inconsistency in the reporting of cartilage defect dimensions in the in vivo models across the different studies. Nevertheless, the outcome measurements were consistently reported with histological analysis, with or without International Cartilage Repair Society (ICRS) scoring and immunohistochemistry (IHC) analysis, across the studies. Clinically, most subjects show improvement in the Knee Injury and Osteoarthritis Outcome Score (KOOS) Sports and Recreation score and KOOS Quality of Life score, as well as reduced Visual Analogue Scale (VAS) average and maximum pain scores. In conclusion, preclinical and clinical studies support amnion as an ideal scaffold material for cartilage tissue engineering and regeneration. Future research should focus on optimizing and standardizing amnion scaffold preparation at a production scale to facilitate the translation of these positive outcomes into clinical applications. This study is funded by the Ministry of Higher Education Malaysia via Prototype Research Grant Scheme (PRGS/1/2021/SKK01/UM/02/1) and UM International Collaboration Grant—2023 SATU Joint Research Scheme Program: ST007-2024.

Periprosthetic joint infection (PJI) remains a challenging complication following total hip arthroplasty (THA), commonly managed through a two-stage revision which can lead to significant morbidity. In this article, we present a rare case of Salmonella enteritidis PJI, initially presenting as prosthetic hip dislocation. Preoperative hip aspiration utilizing blood culture bottles enabled early identification of the organism and guided targeted antimicrobial therapy. The patient underwent revision THA using a well-fixed custom-made articulating spacer (CUMARS) construct, with targeted antibiotic-loaded bone cement. One-year follow-up demonstrated successful eradication of the infection, stable implant fixation, and good functional outcomes. In conclusion, this case underscores the importance of diagnostic hip aspiration and highlights the potential of the CUMARS technique as an effective and durable solution for managing rare PJIs caused by atypical organisms such as Salmonella enteritidis.

Misalignment and improper implant positioning in total knee arthroplasty (TKA) are key predictors of early prosthesis loosening and failure. Correct femoral component rotation is essential for proper patellar tracking, balanced flexion gap, and correct limb alignment during flexion. The objective of this study is to assess and compare the precision of femoral component rotational placement between robotic-assisted TKA (RA-TKA) and navigation-assisted TKA (NA-TKA) surgeries. This single-surgeon retrospective case-control study involved 60 knees from 37 patients, with 30 knees in the robotic-assisted group and 30 knees in the navigation-assisted group. The procedures utilized either a semi-active robotic system (MAKO) or an image-free eNlite navigation system. Femoral component rotational placement and limb alignment were assessed using computed tomography scans and full-length standing anterior-posterior radiographs. The NA-TKA group had a higher proportion of female patients (80%) and was younger on average (64.9 ± 18.4 years), while the RA-TKA group had 65% female patients with an average age of 68.4 ± 8.1 years. There were no significant differences in the absolute errors between intraoperative plans and postoperative alignment of the femoral component in the axial plane between RA-TKA (0.9°±1.9°) and NA-TKA (0.6°±1.6°). Postoperative hip-knee-ankle angles were similarly restored in both groups (RA-TKA: 0.2°±2.6°, NA-TKA: 0.9°±1.7°; p = 0.22). The NA-TKA group had fewer outliers (> 3°) for femoral component rotational placement (p = 0.45). Our study indicates that RA-TKA achieves similar accuracy in femoral component rotational placement compared to NA-TKA. While RA-TKA aims for the highest accuracy in femoral component placement, it may not necessarily surpass the accuracy of navigation-assisted techniques. Level III.