What Are the Functional, Radiographic, and Survivorship Outcomes of a Modified Cup-Cage Technique for Pelvic Discontinuity?

BACKGROUND: Pelvic discontinuity (PD) presents a complex challenge in revision hip arthroplasty. The traditional cup-cage construct, which involves a screw-secured porous metal cup and an overlying antiprotrusio cage, has shown promising mid- to long-term results. However, there is limited information on the outcomes of modifications to the original technique. Our study aims to evaluate a modified technique in which the cup position is determined by the placement of the overlying cage, allowing for adjustments to achieve optimal orientation. QUESTIONS/PURPOSES: Among patients treated for PD with a cup-cage construct in which the cup position was dictated by the position of the cage: (1) What are Harris hip scores achieved at a minimum of 2 years of follow-up? (2) What is the Kaplan-Meier survivorship free from aseptic loosening or component migration? (3) What is the Kaplan-Meier survivorship free from revision for any reason? (4) What surgical complications are associated with the procedure? METHODS: Between October 2013 and January 2022, we performed 805 acetabular revisions. Among these, 33 patients with PD confirmed intraoperatively were considered potentially eligible for a cup-cage construct; no other method of surgical management was used. We performed 64% (21 of 33) of these procedures from October 2013 to January 2018, with 6% (2 of 33) of patients lost to follow-up before the minimum study follow-up of 2 years; these 19 patients were monitored over a period ranging from 70 to 115 months. A further 12 patients underwent this procedure from January 2018 to January 2022, with one lost to follow-up before the minimum study follow-up of 2 years; the other patients met the minimum 2-year follow-up requirement. The remaining 30 patients with data analyzed here (10 men, 20 women) had a mean ± SD age of 61 ± 12 years and a median BMI of 29 kg/m2 (range 20 to 33 kg/m2) at the time of revision surgery. Twenty-one patients underwent revision due to aseptic loosening, and nine due to periprosthetic joint infection (PJI). The causes of PD in our patients were as follows: cup aseptic loosening without significant osteolysis in 20% (6 of 30), where the loose cup caused erosion of the host bone, leading to PD; PJI in 30% (9 of 30); intraoperative iatrogenic PD in 3% (1 of 30); and osteolysis in 47% (14 of 30), which also resulted in aseptic loosening. The median follow-up time was 79 months (range 25 to 115 months). The Harris hip score was used to evaluate clinical outcomes, with preoperative values compared with the most recent follow-up. Radiographs were reviewed by two experienced surgeons at each follow-up visit to assess component loosening (defined as migration > 5 mm or the presence of circumferential radiolucent lines) or clear migration. PD was considered healed if bridging callus or trabecular bone was visible across the site of the discontinuity. Complications were assessed through a comprehensive review of electronic medical records. Kaplan-Meier analysis was used to estimate implant survivorship and radiographic loosening, with aseptic loosening or component migration as the endpoint, as well as survivorship free from any reoperation. RESULTS: The Harris hip score improved from a median of 39 (range 30 to 66) preoperatively to a median of 76 (range 30 to 90) postoperatively (median difference 33 [range 2 to 48]; p < 0.01). Within the limitations of two-dimensional (2D) radiographic imaging, successful bone graft integration and the healing of PD were noted in 83% (25 of 30) of patients. Kaplan-Meier survivorship free from radiographic signs of aseptic loosening or component migration was 100% (95% CI 100% to 100%) at 115 months. When any revision related to the acetabular component was considered the endpoint, survivorship free from acetabular component revision at 115 months after revision surgery was 100% (95% CI 100% to 100%). When the need for any reoperation was considered the endpoint, survivorship free from needing reoperation at 115 months after revision surgery was 85% for all patients (95% CI 73% to 100%). When including only patients with a follow-up time of > 4 years (20 of 30), survivorship free from needing reoperation at 115 months after revision surgery was 90% (95% CI 78% to 100%). Postoperative complications during the follow-up period included one early dislocation on the fifth day after surgery, treated with closed reduction and 6 weeks of abduction bracing. One femoral stem loosening occurred at 56 months postoperatively, although the acetabular component remained securely fixed; this patient declined revision surgery. One patient experienced a dislocation 5 months after surgery but refused treatment and opted for prolonged bed rest. Additionally, one patient underwent a debridement, antibiotics, and implant retention procedure 1 week after the revision surgery and subsequently showed no signs of infection at the latest follow-up, 38 months postoperatively. CONCLUSION: Our study highlights the effectiveness of a modified cup-cage technique in complex hip revisions, showing promising results in terms of construct survivorship and low complication rates. Surgeons could consider delaying screw fixation until after positioning the cage within the porous cup to allow for optimal adjustment and using metal augments for severe bone defects to achieve better alignment. Surgeon experience with the cup-cage technique is crucial for achieving optimal outcomes. Future studies should focus on long-term follow-up visits to assess the durability and effectiveness of these modifications and explore the comparative effectiveness versus other methods, such as custom triflange components and jumbo cups with distraction. LEVEL OF EVIDENCE: Level III, therapeutic study.

Efficacy and safety of postoperative single-dose anticoagulant treatment in preventing venous thromboembolism after revision hip arthroplasty: a retrospective cohort study.

PURPOSE: The purpose of the study is to determine the efficacy and safety of postoperative single-dose anticoagulant treatment in preventing venous thromboembolism (VTE) after revision THA, in comparison with a multiple-dose chemoprophylaxis protocol. METHODS: We retrospectively compared 295 patients undergoing revision THA who received multiple-dose chemoprophylaxis protocol (40 mg low-molecular-weight heparin once and oral rivaroxaban for 10 days) or single-dose chemoprophylaxis protocol (40 mg low-molecular-weight heparin once) for VTE. The patients in both groups performed active lower limb exercises. Each group was further stratified into subgroups based on the aetiology of revision. The incidence of VTE, wound complications within three months, hidden blood loss (HBL), transfusion rate, and surgical drainage duration were recorded. RESULTS: The incidence rates of VTE (P = 0.870) did not differ between the two prophylaxis protocols. However, significant differences were observed in wound complications within three months (P = 0.002), HBL (P = 0.015), transfusion rate (P = 0.028). Surgical drainage duration was also shorter in the single-dose chemoprophylaxis group (P = 0.0023). In the subgroup analysis, the use of single-dose chemoprophylaxis protocol cannot significantly reduce HBL and transfusion rate after septic revision THA. The use of multiple-dose chemoprophylaxis protocol (OR = 2.89, P = 0.002) and high BMI (OR = 1.09, P = 0.037) were independent risk factors of wound complications. CONCLUSIONS: Single-dose chemoprophylaxis protocol effectively and safely prevented VTE after revision THA compared with multiple-dose chemoprophylaxis protocol. The effect in reducing HBL and postoperative transfusion rate was limited in septic revision.

Outcome of Irrigation and Debridement With Topical Antibiotics Delivery for the Management of Periprosthetic Joint Infection Occurring Within 3 Months Since the Primary Total Joint Arthroplasty.

BACKGROUND: Irrigation and debridement with modular component exchange is appealing for surgeons to treat early-stage periprosthetic joint infection (PJI). However, the indication, perioperative protocol, and success rate remain controversial. This study is the first one to present results of debridement, antibiotics, and implant retention (DAIR) with integrated MIT (modular component exchange, povidone-iodine and topical antibiotics delivery) protocol for treating PJI occurring within 3 months since the primary total joint arthroplasty. METHODS: We retrospectively analyzed patients who received DAIR with MIT protocol in our department between January 2011 and May 2018. Topical antibiotics were delivered in all cases. Topical antibiotics infusion was applied for those infected with multidrug-resistant bacteria, fungus, polymicrobial infection, and culture negative one. Failure was defined as additional surgical intervention for infection after DAIR; persistent sinus tract, drainage or excessive joint pain; need for suppressive antibiotics therapy due to the infection; infection relapse with the same pathogen; reinfection with different microorganism; and infection-related death. RESULTS: A total of 73 patients with a mean age of 63.30 ± 10.97 years were included in this study, including 43 men and 30 women. There are 41 knees and 32 hips. Thirty patients had sinus tract. With a mean follow-up of 63.79 ± 18.57 months, there were 9 failures in total with an overall success rate of 87.67%. The success rate was 88.57% and 86.84% for those receiving topical antibiotics infusion postoperatively and those without. CONCLUSIONS: DAIR with a standard MIT protocol is a viable and safe option for PJI occurring within 3 months since the primary total joint arthroplasty. LEVEL OF EVIDENCE: Level 4, therapeutic study.

The in vitro and in vivo performance of a strontium-containing coating on the low-modulus Ti35Nb2Ta3Zr alloy formed by micro-arc oxidation.

The ß-titanium alloy is thought to be a promising alloy using as orthopedic or dental implants owing to its characteristics, which contains low elastic modulus, high corrosion resistance and well biocompatibility. Our previous study has reported that a new ß-titanium alloy Ti35Nb2Ta3Zr showed low modulus close to human bone, equal tissue compatibility to a traditional implant alloy Ti6Al4V. In this study, micro-arc oxidation (MAO) was applied on the Ti35Nb2Ta3Zr alloy to enhance its surface characteristics and biocompatibility and osseointegration ability. Two different coatings were formed, TiO2 doped with calcium-phosphate coating (Ca-P) and calcium-phosphate-strontium coating (Ca-P-Sr). Then we evaluated the effects of the MAO coatings on the Ti35Nb2Ta3Zr alloy through in vitro and in vivo tests. As to the characteristics of the coatings, the morphology, chemical composition, surface roughness and contact angle of MAO coatings were tested by scanning electron microscopy, energy dispersive spectroscopy, atomic force microscopy, and video contact-angle measurement system respectively. Besides, we performed MTT assay, ALP test and cell morphology-adhesion test on materials to evaluate the MAOed coating materials' biocompatibility in vitro. The in vivo experiment was performed through rabbit model. Alloys were implanted into rabbits' femur shafts, then we performed micro-CT, histological and sequential fluorescent labeling analysis to evaluate implants' osseointegration ability in vivo. Finally, the Ca-P specimens and Ca-P-Sr specimens exhibited a significant enhancement in surface roughness, hydrophilicity, cell proliferation, cell adhesion. More new bone was found around the Ca-P-Sr coated alloy than Ca-P coated alloy and Ti35Nb2Ta3Zr alloy. In conclusion, the MAO treatment improved in vitro and in vivo performance of Ti35Nb2Ta3Zr alloy. The Ca-P-Sr coating may be a promising modified surface formed by MAO for the novel ß-titanium alloy Ti35Nb2Ta3Zr.

Strontium Ameliorates Glucocorticoid Inhibition of Osteogenesis Via the ERK Signaling Pathway.

Glucocorticoid (GC) has been widely used in clinical work due to its anti-inflammatory and immune-inhibitory properties. However, long-term or high-dose administration is associated with side effects, such as GC-induced osteoporosis (GIOP), which causes great pain for and poses a heavy financial burden on patients. We sought to investigate the potential effects of strontium on GIOP and further explore its underlying mechanisms, including its reversal of the inhibitory effect of GC on osteogenesis of bone marrow-derived mesenchymal stem cells (BMSCs). We incubated BMSCs with Dexamethasone (DEX) in combination with or without strontium and then measured osteogenic and adipogenic gene expression levels by RT-qPCR and Western blot. We added a specific ERK signaling pathway inhibitor, U0126, to evaluate the involvement of that pathway. Strontium promoted osteogenic differentiation and matrix mineralization in DEX-treated BMSCs, accompanied by upregulation of RUNX2, Osx, ALP, BSP, COL1A1, and OCN. DEX blocked the expression of several osteogenesis-related marker genes by activating the ERK signaling pathway. U0126 attenuated the suppression of osteogenesis in DEX-treated BMSCs. These results suggested that strontium could enhance osteogenic differentiation and matrix mineralization by counteracting DEX's inhibitory effect on osteogenesis via the ERK signaling pathway. Therefore, strontium might be a promising therapeutic agent for GIOP.

Artesunate alleviates interleukin­1ß­induced inflammatory response and apoptosis by inhibiting the NF­κB signaling pathway in chondrocyte­like ATDC5 cells, and delays the progression of osteoarthritis in a mouse model.

Osteoarthritis (OA) is a progressive and degenerative joint disorder that is highly prevalent worldwide and for which there is currently no effective medical therapy. Artesunate (ART), a natural compound used to treat malaria, possesses diverse biological properties, including the regulation of inflammation and apoptosis in various cells; however, its role in OA remains unclear. The aim of the present study was to investigate the effects of ART on interleukin (IL)­1ß­induced chondrocyte­like ATDC5 cells and in an OA mouse model. The results revealed that ART dose­dependently relieved the inhibitory effect of IL­1ß on cell viability. Moreover, ART significantly reduced the overexpression of matrix metalloproteinase (MMP)­3, MMP­13, a disintegrin and metalloproteinase with thrombospondin motifs­5 and cyclooxygenase­2 at both the gene and protein levels in chondrocyte­like ATDC5 cells stimulated by IL­1ß. Furthermore, ART decreased the expression of pro­apoptotic Bax, cleaved caspase­3 and cleaved caspase­7 in a dose­dependent manner, and increased the expression of the anti­apoptotic factor Bcl­2. These changes were mediated by the inhibitory effect of ART on the nuclear factor­κB signaling pathway, defined as repression of the phosphorylation of IκBα and p65, and improved redistribution of p65. Additionally, ART blocked the advancement of the calcified cartilage zone and the loss of proteoglycan, and lowered histological scoring of OA in a mouse model. Taken together, these results indicate that ART may be of value as a therapeutic agent for OA.

Artesunate, an Anti-Malaria Agent, Attenuates Experimental Osteoarthritis by Inhibiting Bone Resorption and CD31hiEmcnhi Vessel Formation in Subchondral Bone.

Osteoarthritis (OA) is a common and debilitating joint disease worldwide without interventions available to reverse its progression. Artesunate (ART), an anti-malaria agent, possesses diverse biological activities, including the inhibition of osteoclastogenesis and angiogenesis in various cells, but its role in subchondral bone during OA progression is not known. Here, we explored the curative effects of ART on the pathogenesis of OA in anterior cruciate ligament transection (ACLT) mice models. We found that ART attenuated articular cartilage degeneration, defined by lowered histologic scoring of OA and retarded calcification of the cartilage zone. Moreover, ART improved the expression of lubricin and aggrecan and reduced the expression of collagen X (Col X) and matrix metalloproteinase-13 (MMP-13). In parallel, ART normalized abnormal subchondral bone remodeling by maintaining bone volume fraction (BV/TV) and subchondral bone plate thickness (SBP Th) and reducing trabecular pattern factor (Tb.pf) compared to the vehicle-treated mice. Our results indicated that ART suppressed osteoclastic bone resorption through regulating RANKL-OPG system, restored coupled bone remodeling by indirectly inhibiting TGF-ß/Smad2/3 signaling. Additionally, ART abrogated CD31hiEmcnhi vessel formation via downregulating the expression of vascular endothelial growth factor (VEGF) and angiogenin-1 in subchondral bone. In conclusion, ART attenuates ACLT-induced OA by blocking bone resorption and CD31hiEmcnhi vessel formation in subchondral bone, indicating that this may be a new therapeutic alternative for OA.

Silver-nanoparticles-modified biomaterial surface resistant to staphylococcus: new insight into the antimicrobial action of silver.

Titanium implants are widely used clinically, but postoperative implant infection remains a potential severe complication. The purpose of this study was to investigate the antibacterial activity of nano-silver(Ag)-functionalized Ti surfaces against epidemic Staphylococcus from the perspective of the regulation of biofilm-related genes and based on a bacteria-cell co-culture study. To achieve this goal, two representative epidemic Staphylococcus strains, Staphylococcus epidermidis (S. epidermidis, RP62A) and Staphylococcus aureus (S. aureus, USA 300), were used, and it was found that an Ag-nanoparticle-modified Ti surface could regulate the expression levels of biofilm-related genes (icaA and icaR for S. epidermidis; fnbA and fnbB for S. aureus) to inhibit bacterial adhesion and biofilm formation. Moreover, a novel bacteria-fibroblast co-culture study revealed that the incorporation of Ag nanoparticles on such a surface can help mammalian cells to survive, adhere and spread more successfully than Staphylococcus. Therefore, the modified surface was demonstrated to possess a good anti-infective capability against both sessile bacteria and planktonic bacteria through synergy between the effects of Ag nanoparticles and ion release. This work provides new insight into the antimicrobial action and mechanism of Ag-nanoparticle-functionalized Ti surfaces with bacteria-killing and cell-assisting capabilities and paves the way towards better satisfying the clinical needs.

A novel open-porous magnesium scaffold with controllable microstructures and properties for bone regeneration.

The traditional production methods of porous magnesium scaffolds are difficult to accurately control the pore morphologies and simultaneously obtain appropriate mechanical properties. In this work, two open-porous magnesium scaffolds with different pore size but in the nearly same porosity are successfully fabricated with high-purity Mg ingots through the titanium wire space holder (TWSH) method. The porosity and pore size can be easily, precisely and individually controlled, as well as the mechanical properties also can be regulated to be within the range of human cancellous bone by changing the orientation of pores without sacrifice the requisite porous structures. In vitro cell tests indicate that the scaffolds have good cytocompatibility and osteoblastic differentiation properties. In vivo findings demonstrate that both scaffolds exhibit acceptable inflammatory responses and can be almost fully degraded and replaced by newly formed bone. More importantly, under the same porosity, the scaffolds with larger pore size can promote early vascularization and up-regulate collagen type 1 and OPN expression, leading to higher bone mass and more mature bone formation. In conclusion, a new method is introduced to develop an open-porous magnesium scaffold with controllable microstructures and mechanical properties, which has great potential clinical application for bone reconstruction in the future.