Introduction and aim. With the development of minimally invasive surgery (MIS), decreased incision size produces limited visualization leading to an increased risk of adjacent neurovascular structures during the procedure.The aim was to identify the safest zones of surgical procedures for the prevention of major neurovascular structures around the acetabulum. Material and methods. 84 cadaver pelvic specimens with 168 hips were used to analyze the anatomic relationship between the sciatic nerve and the piriformis muscle in the normal Korean population according to sex and height. We performed a qualitative and quantitative analysis of the anatomic relationship between the acetabulum and the sciatic nerve, based on the clockwise direction method, to identify the safety zones of the surgical procedure’s proximity to the acetabulum. Results. The prevalence of type I (normal type) was more than 79% and 88% in males and females, respectively. Distances A, B and E were 7.1±0.78 mm between the 3 and 4 o’clock position, 14.2±0.67 mm between the 8 and 9 o’clock position, 17.0±1.22 mm in the 9 o’clock position, respectively, on the left side, whereas 6.0±0.69 mm between the 8 and 9 o’clock position, 14.8±0.59 mm in the 7 o’clock position, 17.9±1.08 mm in the 3 o’clock position on the right side. The proximity of the retractors to acetabulum should be placed with careful and proper retraction between the 3 and 5 o’clock position on the left side and between the 7 and 9 o’clock position on the right side, in which the placement in the 9 and 3 o’clock position should be cautious on the right and left side, respectively. The cautious use of electrocautery between the 3 and 5 o’clock position on the left side, and between the 7 and 9 o’clock position on the right side, is recommended. However, performing the electrocauterization in the 9 o’clock and 3 o’clock position respectively on the left and right side should be avoided. It is forbidden between the 10 and 12 on the left side and between 12 and 2 o’clock position on the right side. The absolute safety zones for the placement of the transacetabular screw were between 1 and 3, and between the position 5 and the 6 o’clock position on the left side and between the position 9 and 11, and between the 6 and 7 on the right side. Relative safe zones were between 12 and 1, and between the 6 and 7 o’clock position on the left and between the 11 and 12, and between the 5 and 6 o’clock positions on the right side. Screws with a length of <24mm could be safely inserted between the 3 and 5 o’clock position on the left side and between the 7 and 9 o’clock position on the right side. The risk zones were between 7 and 9, and between the 9 and 12 hours on the left side, and between 3 and 5, and between the 12 and 3 o’clock position on the right side. In cases with highly elevated trochanter major, the distances between the acetabulum and adjacent neurovascular structures changed and the risk of the SN increased. Conclusion. These data could be helpful for arthroplasty surgeons in avoiding neurovascular injuries in MIS THA.

Background: Infection control rate of debridement, antibiotics, and implant retention (DAIR) remains controversial. We aim to identify the influence of preoperative negative pressure wound therapy (NPWT) with intermittent pulsatile irrigation (IPI) on the efficacy of DAIR in delayed periprosthetic joint infection (PJI) hip cases. Methods: 112 patients with delayed hip PJI were randomized into two groups. Group A included 53 cases treated with DAIR only whereas group B included 59 cases treated with NPWT and IPI followed by DAIR. Surgical invasiveness parameters, postoperative drainage, inflammation markers, and reinfection rate were evaluated in two groups. Results: In group B, serologic and clinical inflammation markers decreased significantly than in group A, and major systemic or local adverse events were not observed during preoperative NPWT-based therapy. The duration of debridement and surgical invasiveness indices such as hemoglobin decrease were significantly lower in group B. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were significantly lower in group B until 3 weeks after DAIR. In group B, the duration of antibiotics administration was considerably shorter than in group A. In groups A and B, reinfection rates were 35.8% and 1.7% at the final follow-up. Conclusions: Preoperative and postoperative NPWT could maximize DAIR's indication and success rate in delayed PJI cases.

Rheumatoid arthritis (RA) is a slow-progressive inflammatory autoimmune disorder characterized by synovial inflammation, hyperplasia, and joint degradation, leading to joint destruction and poor patients’ quality of life. Numerous in vitro RA models have been developed to elucidate disease mechanisms and identify therapeutic targets; however, most fail to fully recapitulate the in vivo synovial microenvironment, including the cellular heterogeneity, biomechanical stress, and dynamic cell-matrix interactions, limiting their translational relevance. This translational gap underscores the need for advanced 3D microengineered platforms that integrate patient-specific cells, biomechanical elements, and real-time biosensing to bridge in vitro findings to clinical outcomes. Recent progress in microengineering has enabled the development of systems that closely mimic the physiological and pathological conditions of the RA synovial membrane in vitro. This review highlights recent progress in microengineered synovial models and their applications in elucidating RA pathogenesis and seeking therapeutic interventions. We also introduce persisting technical and biological challenges, and emerging trajectories for innovation within this rapidly advancing discipline.