BACKGROUND:Anterior cruciate ligament (ACL) injuries are common, yet little is known about the relationship between time from injury to reconstruction and biological characteristics at the femoral insertion site. This study evaluated whether longer time from ACL injury to reconstruction was associated with differences in vascularity and bone microarchitecture at the femoral ACL footprint. METHODS:In this observational cohort study with cross-sectional histological assessment, 60 adult patients (22-53 years) undergoing primary ACL reconstruction and 10 reference patients (55-65 years) undergoing total knee arthroplasty (TKA) were enrolled. A 4.5-mm femoral bone core was harvested from the ACL femoral footprint or an anatomically corresponding site in the TKA reference cohort. Specimens underwent histological analysis and CD34 immunohistochemistry. The primary outcome was microvessel density (MVD; vessels/mm²). Secondary outcomes included CD34-positive cell cluster density and osteocyte lacunar density, quantified separately in three predefined regions (articular, median, and cranial). Analyses included correlation analyses, mixed-model ANOVA, and exploratory subgroup analyses according to age and time from injury to surgery. RESULTS:Longer time from injury to surgery was associated with lower MVD and CD34-positive cluster density. Patients undergoing ACL reconstruction within 9 months of injury had higher mean articular-region MVD than those undergoing reconstruction after ≥9 months (2.96 ± 0.89 vs 0.40 ± 0.96 vessels/mm²; p = 0.014). Osteocyte lacunar density was also associated with time from injury to surgery. Exploratory age-stratified analyses suggested that the magnitude of some associations may vary according to age. Smoking was associated with lower vascular parameters, with smokers demonstrating lower mean vessel density than non-smokers (2.6 vs 3.4 vessels/mm²; p = 0.032). CONCLUSIONS:Longer time from ACL injury to reconstruction, particularly intervals exceeding 9 months, was associated with lower vascular and bone microstructural parameters at the femoral insertion site. Exploratory subgroup analyses suggested potential age-related differences, while smoking was also associated with lower vascular parameters. These findings indicate that prolonged time from injury to surgery may be accompanied by differences in the local biological environment; however, the cross-sectional design precludes causal inference, and the relationship between these histological findings and postoperative graft performance remains uncertain. LEVEL OF EVIDENCE:III; cohort study with histological evaluation.
INTRODUCTION:The management of chronic prosthetic hip joint infection is complex, typically requiring prolonged antibiotic therapy in combination with complete prosthesis exchange, performed either in a single stage or in two stages. However, the removal of a well-osseointegrated prosthetic component carries significant surgical risks that may adversely affect the outcome of the therapeutic strategy. The partial exchange strategy, understood as the removal of a single prosthetic component while retaining the well-integrated one, has emerged as an alternative approach for the management of selected chronic prosthetic hip joint infections. The primary objective of this study was to review the available evidence on partial prosthetic exchange for the management of chronic hip prosthetic joint infection (PJI). PATIENTS AND METHODS:Studies evaluating partial prosthetic exchange as a treatment for chronic hip prosthetic joint infection up to February 2025 were included. The search terms used were "management prosthetic infection", "partial joint arthroplasty", "retention of well-fixed stem" and "partial exchange". The search was conducted using databases such as PubMed and Ovid. Studies involving other joints, partial prostheses, or cases of acute or hematogenous infection were excluded. RESULTS:Twenty-one studies with chronic prosthetic hip infection treated with partial exchange were included (319), most published between 2009 and 2025 and all studies were retrospective. The mean age was 63.1 (SD7 years). A two-stage strategy predominated (250 PJIs, 78.4%) compared to one-stage procedures (69 PJIs, 21.6%). Among monomicrobial infections, Gram-positive bacteria were the predominant pathogens (202 cases, 74.7%), with coagulase-negative staphylococci and Staphylococcus aureus being the most frequently isolated microorganisms. The mean time between surgeries was 18.2 weeks (SD 11.9), with substantial heterogeneity in antibiotic regimens. The mean follow-up was 4.9 years (SD 2.0). The overall success rate was 89.3% in the intention-to-treat analysis (285 cases), similar to the per-protocol analysis (89.2%, 281 cases). Two-stage partial exchange showed a higher success rate (90.4%; 226 PJIs) than one-stage procedures (85.5%; 59 PJIs). A total of 34 failures were reported, frequently associated with Staphylococcus spp. (14 PJIs; 41.2% of the failures). Functional outcomes, when reported, showed improvement after the procedure, although this information was not systematically provided across all studies. DISCUSSION:Partial exchange may be a viable strategy for managing chronic prosthetic hip joint infection in a selected group of patients, specifically those with a well-fixed prosthetic component. Removing this component is associated with intraoperative and postoperative complications that may compromise joint stability and function. However, the heterogeneity of the studies limits the establishment of clear patient selection criteria. Further studies with higher-quality and larger populations are needed. LEVEL OF EVIDENCE:IV.
French orthopedic surgeons have played a major role in the development, evaluation, and dissemination of numerous techniques and concepts in conservative orthopedic surgery. In lower-limb surgery, the French contribution has been particularly influential in establishing strong concepts based on the critical assessment of surgical outcomes. Over time, these concepts have gained broad acceptance because of their clinical relevance, reproducibility, and effectiveness, and have contributed to standardizing the management of several orthopedic conditions.Four major concepts are addressed in this article: the comprehensive management for correction of severe objective patellofemoral instability; the correction of adult forefoot deformities; improved control of rotational knee instability through anterolateral reconstruction combined with anterior cruciate ligament reconstruction; and the principles of meniscal preservation and conservation.These concepts illustrate how French orthopedic surgery has contributed not only to the development and refinement of surgical techniques, but also to the emergence of broader treatment philosophies and decision-making frameworks that have influenced contemporary orthopedic practice. This article results from a collaborative effort among French surgeons who were trained in these concepts, contributed to their development and dissemination, and continue to apply them in daily clinical practice.Level of evidence: V; expert opinion
BACKGROUND:Native knee septic arthritis is commonly treated arthroscopically with the primary aim of infection eradication. However, the incidence of postoperative knee stiffness and the need for subsequent surgical procedures after successful treatment remain poorly defined. HYPOTHESIS:We hypothesized that, despite successful infection control, postoperative stiffness and the need for secondary surgical procedures represent frequent and clinically significant complications after arthroscopic treatment of native knee septic arthritis. METHODS:A retrospective single-centre cohort study was conducted including adult patients treated arthroscopically for culture-confirmed native knee septic arthritis between 2013 and 2022. Postoperative stiffness was defined as knee flexion ≤90 ° and/or extension deficit ≥10 ° at 1 year after infection eradication. Range of motion was assessed using standardized clinical goniometric measurements. Secondary outcomes included aseptic reoperations, arthrolysis, conversion to total knee arthroplasty, and Knee injury and Osteoarthritis Outcome Score (KOOS-12). Associations between patient-, infection-, and surgery-related variables and outcomes were analysed. RESULTS:Eighty-two patients met the inclusion criteria. Seventy-four had available 1-year follow-up data and were analysed for the primary outcome. Among these 74 patients, mean follow-up was 45.5 ± 28.4 months (range, 12-123). At 1 year, 45/74 patients (60.8%) met at least one stiffness criterion. Flexion ≤90 ° and extension deficit ≥10 ° occurred in 27/74 (36.5%) and 22/74 (29.7%), respectively. Mean flexion was 105.9 ° ± 16.8 (range, 60-130), and mean extension deficit was 4.9 ° ± 5.3 (range, 0-20). Aseptic reoperation was required in 28/74 patients (37.8%), including arthrolysis in 15/74 (20.3%) and total knee arthroplasty in 7/74 (9.5%). Kaplan-Meier aseptic-reoperation-free survival was 77.0% (95% CI, 65.7-85.0) at 12 months and 60.6% (95% CI, 48.1-70.9) at 45 months. Final KOOS-12 was significantly lower in patients with stiffness than in those without stiffness (65.3 ± 17.3 vs 80.0 ± 15.5; p < 0.001). CONCLUSION:Postoperative stiffness is a frequent and clinically relevant complication following successful arthroscopic treatment of native knee septic arthritis. Successful infection eradication was not systematically synonymous with complete functional recovery, and secondary surgery was frequently required during follow-up. LEVEL OF EVIDENCE:Level IV, retrospective cohort study.
