Correlation between synovial fluid and serum IL-1beta levels after ACL surgery-preliminary report

Polymorphism of Genes Encoding Inflammatory Interleukins and the Risk of Anterior Cruciate Ligament Injury: A Systematic Review and Meta-Analysis

Sport injuries, including the anterior crucial ligament rupture (ACLR) seem to be related to complex genetic backgrounds, including the genes responsible for inflammatory response. This review and meta-analysis investigated the contribution of the polymorphisms of genes encoding inflammatory cytokines and their receptors to the risk of ACLR. The scientific databases Science Direct, EBSCO host, Scopus, PubMed, and Google Scholar were screened (completed on 14 June 2023) according to the established inclusion/exclusion criteria (only fully accessible, original, human case-control studies written in English concerning the effect of interleukin genes' polymorphisms on the occurrence of ACL injury were included) and statistical meta-analysis using R version 4.0.3 was performed. The PRISMA methodology was used to review articles. The review protocol was registered under the number CRD42024514316 in the Prospero database. Eighty-nine studies were identified and narrowed down to three original case-control studies used for the meta-analysis. The studies analyzed Polish, South African, and Swedish cohorts, altogether 1282 participants. The candidate polymorphisms indicated in the studies involved IL6 rs1800795, IL6R rs2228145 and IL1B rs16944. The systematic review showed the relationships between IL6 rs1800795 polymorphism and ACLR in the Polish subpopulation, and IL6R rs2228145 and IL1B rs16944 in the South African subpopulations. The meta-analysis revealed that the IL6 rs1800795 CG genotype was over-represented (OR = 1.30, 95% CI 1.02-1.66), while the CC genotype was under-represented (OR = 0.75, 95% CI 0.54-1.03) in ACLR subjects, but no significant impact of IL6R rs2228145 was shown. Additionally, a tendency of the IL1B rs16944 CT genotype to be protective (OR 0.89, 95% CI 0.70-1.14), while the TT to be a risk genotype (OR 1.19, 95% CI 0.84-1.68) was observed. Thus, the relationship between the interleukin receptor IL6R rs2228145 and ACLR risk was not confirmed. However, the impact of genes coding pleiotropic IL6 rs1800795 on the incidences of ACLR was clear and the effect of pro-inflammatory IL1B rs16944 was possible.

Anterior Screw Insertion Results in Greater Tibial Tunnel Enlargement Rates after Single-Bundle Anterior Cruciate Ligament Reconstruction than Posterior Insertion: A Retrospective Study

Background and Objectives: Tunnel enlargement (TE) is a widely reported phenomenon after anterior cruciate ligament reconstruction (ACLR). Given the paucity of knowledge in the literature, it remains unclear whether screw position in the tunnel affects TE. This retrospective cohort study evaluated differences in postoperative tunnel enlargement rates (TER) and clinical results between anterior and posterior tibial interference screw insertion during single-bundle ACLR using autologous hamstring grafts. Materials and Methods: A group of consecutive patients that underwent primary arthroscopic single-bundle ACLR in our hospital were screened and divided into two groups based on the position of the tibial interference screw (determined by Computer Tomography within 3 days after surgery): anterior screw position group (A) and posterior screw position group (B). The bone tunnel size was measured using magnetic resonance imaging (MRI) performed 1 year after surgery. International Knee Documentation Committee (IKDC) score and the Knee Injury and Osteoarthritis Outcome Score (KOOS) were used for clinical results 1 year postoperatively. Results: 87 patients were included. The TER of Group A is higher than that of Group B (43.17% vs. 33.80%, p = 0.024). Group A showed a significant increase (12.1%) in enlargement rates at the joint line level than group B (43.77% vs. 31.67%, p = 0.004). Moreover, KOOS and IKDC scores improved in both groups. There were no significant differences in clinical outcomes between the two groups. Conclusions: One year after ACLR, patients with posterior screw showed significantly lower TE than patients with anterior screw. However, the position of screw did not lead to differences in clinical results over our follow-up period. Posterior screw position in the tibial tunnel maybe a better choice in terms of reducing TE. Whether the different screw positions affect the long-term TE and long-term clinical outcomes needs to be confirmed by further studies.

A2M inhibits inflammatory mediators of chondrocytes by blocking IL-1β/NF-κB pathway

A hallmark of osteoarthritis (OA) is cartilage degeneration, which has been previously correlated with dramatic increases in inflammatory enzymes. Specifically, interleukin-1β (IL-1β) and subsequent upregulation of nuclear factor kappa B (NF-κB) is implicated as an important player in the development of posttraumatic osteoarthritis (PTOA). Alpha 2-macroglobulin (A2M) can inhibit this inflammatory pathway, making it a promising therapy for PTOA. Herein, we demonstrate that A2M binds and neutralizes IL-1β, blocking downstream NF-κB-induced catabolism seen in in vitro. Human chondrocytes (cell line C28) were incubated with A2M protein and then treated with IL-1β. A2M was labeled with VivoTag™ 680 to localize the protein postincubation. The degree of binding between A2M and IL-1β was evaluated through immunoprecipitation (IP). Catabolic proteins, including IL-1β and NF-kB, were detected by Western blot. Pro-inflammatory and chondrocyte-related gene expression was examined by qRT-PCR. VivoTag™ 680-labeled A2M was observed in the cytoplasm of C28 human chondrocytes by fluorescence microscopy. IP experiments demonstrated that A2M could bind IL-1β. Additionally, western blot analysis revealed that A2M neutralized IL-1β and NF-κB in a dose-dependent manner. Moreover, A2M decreased levels of MMPs and TNF-α and increased the expression of cartilage protective genes Col2, Type2, Smad4, and aggrecan. Mostly importantly, A2M was shown to directly neutralize IL-1β to downregulate the pro-inflammatory responses mediated by the NF-kB pathway. These results demonstrate a mechanism by which A2M reduces inflammatory catabolic activity and protects cartilage after joint injury. Further in vivo studies are needed to fully understand the potential of A2M as a novel PTOA therapy.

A Cell-free Biodegradable Synthetic Artificial Ligament for the Reconstruction of Anterior Cruciate Ligament in a Rat Model

Traditional Anterior Cruciate Ligament (ACL) reconstruction is commonly performed using an allograft or autograft and possesses limitations such as donor site morbidity, decreased range of motion, and potential infection. However, a biodegradable synthetic graft could greatly assist in the prevention of such restrictions after ACL reconstruction. In this study, artificial grafts were generated using "wet" and "dry" electrospinning processes with a biodegradable elastomer, poly (ester urethane) urea (PEUU), and were evaluated in vitro and in vivo in a rat model. Four groups were established: (1) Wet PEUU artificial ligament, (2) Dry PEUU artificial ligament, (3) Dry polycaprolactone artificial ligament (PCL), and (4) autologous flexor digitorum longus tendon graft. Eight weeks after surgery, the in vivo tensile strength of wet PEUU ligaments had significantly increased compared to the other synthetic ligaments. These results aligned with increased infiltration of host cells and decreased inflammation within the wet PEUU grafts. In contrast, very little cellular infiltration was observed in PCL and dry PEUU grafts. Micro-computed tomography analysis performed at 4 and 8 weeks postoperatively revealed significantly smaller bone tunnels in the tendon autograft and wet PEUU groups. The Wet PEUU grafts served as an adequate functioning material and allowed for the creation of tissues that closely resembled the ACL.

Bioresorbable Stent in Anterior Cruciate Ligament Reconstruction

The exact causes of failure of anterior cruciate ligament (ACL) reconstruction are still unknown. A key to successful ACL reconstruction is the prevention of bone tunnel enlargement (BTE). In this study, a new strategy to improve the outcome of ACL reconstruction was analyzed using a bioresorbable polylactide (PLA) stent as a catalyst for the healing process. The study included 24 sheep with 12 months of age. The animals were randomized to the PLA group (n = 16) and control group (n = 8), subjected to the ACL reconstruction with and without the implantation of the PLA tube, respectively. The sheep were sacrificed 6 or 12 weeks post-procedure, and their knee joints were evaluated by X-ray microcomputed tomography with a 50 μm resolution. While the analysis of tibial and femoral tunnel diameters and volumes demonstrated the presence of BTE in both groups, the enlargement was less evident in the PLA group. Also, the microstructural parameters of the bone adjacent to the tunnels tended to be better in the PLA group. This suggested that the implantation of a bioresorbable PLA tube might facilitate osteointegration of the tendon graft after the ACL reconstruction. The beneficial effects of the stent were likely associated with osteogenic and osteoconductive properties of polylactide.

A short report on the effect of decreased incubation time on the architectural profile of autologous conditioned serum (ACS)

If present in high enough concentrations, IL-1-Ra has the potential to inhibit Interleukin-1, the chief offender that promotes the pro-inflammatory cascade causing pain, swelling and joint dysfunction associated with osteoarthritis (OA). IL-1-Ra and growth factor levels were quantified from whole blood in this retrospective chart review investigation (n=20) using Zero and 15min incubation times respectively. The hypothesis that this process can significantly (p<0.0001) increase levels of IL-1-Ra was confirmed. Mean Arthrokinex™ induced IL-1-Ra levels reached a concentration of 13,288pg/mL and 12,809pg/mL compared to 518pg/mL at baseline, representing a 26-fold increase. Post conditioning levels of pro-inflammatories IL-1β, IL-6 and TNF α were not changed to any significant degree. The Arthrokinex™ blood conditioning process induces adequate levels of IL-1-Ra to alter the IL-1-Ra: IL-1β ratio and mitigate the inflammatory cascade, while increasing growth factors PDGF and TGF respectively.

Bone tunnel enlargement following hamstring anterior cruciate ligament reconstruction: a comprehensive review

Nowadays, bone tunnel enlargement (BTE) after anterior cruciate ligament reconstruction is a well-known phenomenon. It has been identified, investigated and described by many authors during the last thirty years. Nevertheless, the etiology of bone tunnel enlargement still remains unclear. It is known that the causes are multifactorial and may include the surgical technique, the method of fixation, materials used, type of graft as well as biological factors. Due to the recent popularization of the use of hamstring grafts in anterior cruciate ligament reconstruction, the bone tunnel enlargement phenomenon is becoming increasingly common. In this review article, the authors focus on compiling current knowledge about the etiology, diagnosis, and the possibility of reducing the occurrence of this phenomenon by using the latest methods of supporting reconstruction surgery.

Mechanisms of post-traumatic osteoarthritis after ACL injury

Anterior cruciate ligament (ACL) rupture is a common and devastating injury with long-term sequelae that include meniscal tears, chondral injury, and an increased risk of knee osteoarthritis (OA). ACL reconstruction is recommended to protect against knee instability, reduce the likelihood of meniscal tears and further surgery, and enable earlier return to sporting activities. ACL reconstruction, however, does not reduce the incidence of early-onset OA. In this review, we discuss the factors before and after surgery that are believed to contribute to the premature development of degenerative joint disease.

Dynamic Intraligamentary Stabilization (DIS) for treatment of acute anterior cruciate ligament ruptures: case series experience of the first three years

Background

In recent years, the scientific discussion has focused on new strategies to enable a torn anterior cruciate ligament (ACL) to heal into mechanically stable scar tissue. Dynamic intraligamentary stabilization (DIS) was first performed in a pilot study of 10 patients. The purpose of the current study was to evaluate whether DIS would lead to similarly sufficient stability and good clinical function in a larger case series.

Methods

Acute ACL ruptures were treated by using an internal stabilizer, combined with anatomical repositioning of torn bundles and microfracturing to promote self-healing. Clinical assessment (Tegner, Lysholm, IKDC, and visual analogue scale [VAS] for patient satisfaction scores) and assessment of knee laxity was performed at 3, 6, 12, and 24 months. A one-sample design with a non-inferiority margin was chosen to compare the preoperative and postoperative IKDS and Lysholm scores.

Results

278 patients with a 6:4 male to female ratio were included. Average patient age was 31 years. Preoperative mean IKDC, Lysholm, and Tegner scores were 98.8, 99.3, and 5.1 points, respectively. The mean anteroposterior (AP) translation difference from the healthy contralateral knee was 4.7 mm preoperatively. After DIS treatment, the mean 12-month IKDC, Lysholm, and Tegner scores were 93.6, 96.2, and 4.9 points, respectively, and the mean AP translation difference was 2.3 mm. All these outcomes were significantly non-inferior to the preoperative or healthy contralateral values (p < 0.0001). Mean patient satisfaction was 8.8 (VAS 0–10). Eight ACL reruptures occurred and 3 patients reported insufficient subjective stability of the knee at the end of the study period.

Conclusions

Anatomical repositioning, along with DIS and microfracturing, leads to clinically stable healing of the torn ACL in the large majority of patients. Most patients exhibited almost normal knee function, reported excellent satisfaction, and were able to return to their previous levels of sporting activity. Moreover, this strategy resulted in stable healing of all sutured menisci, which could lower the rate of osteoarthritic changes in future. The present findings support the discussion of a new paradigm in ACL treatment based on preservation and self-healing of the torn ligament.

Dynamic intraligamentary stabilization: novel technique for preserving the ruptured ACL

PURPOSE

Replacement of the torn anterior cruciate ligament (ACL) with a transplant is today`s gold standard. A new technique for preserving and healing the torn ACL is presented.

HYPOTHESIS

a dynamic intraligamentary stabilization (DIS) that provides continuous postinjury stability of the knee and ACL in combination with biological improvement of the healing environment [leucocyte- and platelet-rich fibrin (L-PRF) and microfracturing] should enable biomechanically stable ACL self-healing.

METHODS

Ten sportive patients were treated by DIS employing an internal stabilizer to keep the unstable knee in a posterior translation, combined with microfracturing and platelet-rich fibrin induction at the rupture site to promote self-healing. Postoperative clinical [Tegner, Lysholm, International Knee Documentation Committee (IKDC), visual analogue scale patient satisfaction score] and radiological evaluation, as well as assessment of knee laxity was performed at 6 weeks, 3, 6, 12, and 24 months.

RESULTS

One patient had a re-rupture 5 months postoperative and was hence excluded from further follow-ups. The other nine patients presented the following outcomes at 24 months: median Lysholm score of 100; IKDC score of 98 (97-100); median Tegner score of 6 (range 9-5); anterior translation difference of 1.4 mm (-1 to 3 mm); median satisfaction score of 9.8 (9-10). MRI showed scarring and continuity of the ligament in all patients.

CONCLUSIONS

DIS combined with microfracturing and L-PRF resulted in stable clinical and radiological healing of the torn ACL in all but one patient of this first series. They attained normal knee scores, reported excellent satisfaction and could return to their previous levels of sporting activity.

LEVEL OF EVIDENCE

Case series with no comparison group, Level IV.

Identification of α2-macroglobulin as a master inhibitor of cartilage-degrading factors that attenuates the progression of posttraumatic osteoarthritis

OBJECTIVE

To determine if supplemental intraarticular α2-macroglobulin (α2 M) has a chondroprotective effect in a rat model of osteoarthritis (OA).

METHODS

Using Western blotting, mass spectrometry, enzyme-linked immunosorbent assay (ELISA), and immunohistochemistry, α2 M was identified as a potential therapeutic agent through a comparison of α2 M concentrations in serum, synovial fluid (SF), and cartilage from normal subjects and patients with OA. In cultured chondrocytes, the effects of α2 M on interleukin-1 (IL-1)-induced cartilage catabolic enzymes were evaluated by Luminex assay and ELISA. In vivo effects on cartilage degeneration and matrix metalloproteinase 13 (MMP-13) concentration were evaluated in male rats (n = 120) randomized to 1 of 4 treatments: 1) anterior cruciate ligament transection (ACLT) and saline injections, 2) ACLT and 1 IU/kg injections of α2 M, 3) ACLT and 2 IU/kg injections of α2 M, or 4) sham operation and saline injections. Rats were administered intraarticular injections for 6 weeks. The concentration of MMP-13 in SF lavage fluid was measured using ELISA. OA-related gene expression was quantified by real-time quantitative polymerase chain reaction. The extent of OA progression was graded by histologic examination.

RESULTS

In both normal subjects and OA patients, α2 M levels were lower in SF as compared to serum, and in OA patients, MMP-13 levels were higher in SF than in serum. In vitro, α2 M inhibited the induction of MMP-13 by IL-1 in a dose-dependent manner in human chondrocytes. In the rat model of ACLT OA, supplemental intraarticular injection of α2 M reduced the concentration of MMP-13 in SF, had a favorable effect on OA-related gene expression, and attenuated OA progression.

CONCLUSION

The plasma protease inhibitor α2 M is not present in sufficient concentrations to inactivate the high concentrations of catabolic factors found in OA SF. Our findings suggest that supplemental intraarticular α2 M provides chondral protection in posttraumatic OA.

Anterior cruciate ligament regeneration using mesenchymal stem cells and collagen type I scaffold in a rabbit model

PURPOSE

The objective of this study was to determine whether using mesenchymal stem cells (MSC) seeded in a collagen type I scaffold would be sufficient to regenerate the torn anterior cruciate ligament (ACL).

METHODS

Anterior cruciate ligament transection was performed on both knees in 10 New Zealand rabbits and then repaired with as follows: suture alone (suture-treated group, n = 6), suture associated with collagen type I scaffold (collagen type I scaffold-treated group, n = 8) or suture associated with autologous MSC seeded on collagen type I scaffold (MSC/collagen type I scaffold-treated group, n = 6). At 12-week post-intervention, the animals were killed and the ACLs were characterised macroscopically and histologically. Data of the 3 groups were against normal ACL (normal group, n = 10).

RESULTS

Macroscopic observation found that in MSC/collagen type I scaffold group, 33% of specimens showed a complete ACL regeneration, with a tissue similar to the normal ACL. Regeneration was not observed in the group treated with suture alone or associated with collagen type I scaffold without cells. In the latter, only a reparative attempt at the ends was observed. Histological analysis of the regenerated ACL showed a tissue with organised collagen and peripheric vessels.

CONCLUSIONS

These results provide evidence that the use of MSC seeded in a collagen type I scaffold in the treatment of ACL injuries is associated with an enhancement of ligament regeneration. This MSC-based technique is a potentially attractive tool for improving the treatment of ACL ruptures.

The role of cytokines in posttraumatic arthritis

The development of arthritis after joint injury is commonly known as posttraumatic arthritis (PTA). The inciting traumatic event may range from cartilage contusion and bone bruise combined with meniscus or ligament tear, to intra-articular fracture. End-stage PTA is often indistinguishable from primary osteoarthritis. However, knowing the time of the inciting traumatic event in a patient with PTA provides an opportunity to understand the events following joint injury that lead to the progression of arthritis. Joint injury often leads to mechanical alterations in loading of the injured joint, and restoration of joint mechanics through surgical repair remains an important aspect of treatment. However, the accuracy of joint reduction by itself does not account for the variability in outcome following joint injury, as evidenced by the fact that PTA remains a significant clinical problem. Emerging research in animal models and human subjects indicates that several inflammatory cytokines and related inflammatory mediators are elevated following joint injury. Data from animal studies and early clinical trials suggest that early inhibition of the intra-articular inflammatory response may improve clinical outcomes.

Surface functionalized mesoporous silica nanoparticles with natural proteins for reduced immunotoxicity

Mesoporous silica nanoparticles (MSNs) present themselves as one of the most promising nano-carriers for drug delivery. To reduce their immunotoxicities, in this study, natural proteins of gelatin (Gel), bovine serum albumin (BSA), and lysozyme (Lys) were employed as end-caps of MSNs by using succinic anhydride as an intermediate linker, thus leading to fabrication of MSNs/protein nanocomposites, respectively. Furthermore, combined techniques of SEM, TEM, FTIR, and zeta potential instruments were utilized to monitor the construction processes of MSNs/protein nanocomposites, respectively. Finally, the immunotoxicities of those nanocomposites to macrophage cells (RAW264.7 cells) were investigated in detail, i.e., cell morphology, cell viability, nitric oxide (NO) production, reactive oxygen species (ROS), and acid phosphatase activity (ACP) as well as inflammation cytokine expressions (tumor necrosis factor-α and interleukin-1β). All results suggest that macrophages were activated after uptaking nanoparticles of SiO2 and MSNs, which subsequently induced severe inflammation responses in vitro. In contrast, the inflammation responses of MSNs nanocomposites were reduced dramatically after end-capping with those natural proteins. Overall, this study accumulates knowledge for the development of MSNs-based drug delivery systems with reduced immunotoxicity.

Use of autologous conditioned serum (Orthokine) for the treatment of the degenerative osteoarthritis of the temporomandibular joint. Review of the literature

Objectives: Treatment of osteoarthritis (OA) using autologous conditioned serum (ACS) has become in recent years an alternative to consider in the approach of the degenerative joint disease of the knee. There is no support in the literature for the use of ACS for the treatment of OA of the temporomandibular joint (TMJ), although the promising results obtained in human patients with knee joint disease as well as in animal studies are opening the way for its use at the TMJ. The aim of this paper is to conduct a review of the published literature regarding the use of the ACS for the treatment of OA in humans, considering the level of scientific evidence, and following the principles of the evidence-based medicine and dentistry. Material and Methods: A PubMed-MEDLINE search was carried out of articles published between 1980 and 2011. After an initial search, a total of 102 articles were obtained, followed by a selection of the most relevant articles according to the topic; a total of 8 articles were selected, which were stratified according to their level of scientific evidence using SORT criteria (Strength of Recommendation Taxonomy). Results: At the time of this review, there is no available literature referring the use of ACS at the TMJ. However, the use of the ACS in other joints is well documented, both experimentally and clinically, in humans and animals. The reviewed articles, with a level of evidence 1 and 2 according to the SORT criteria, have generally promising results. Discussion and Conclusions: The use of ACS in the treatment of OA in joints other than the TMJ, is endorsed by the level of evidence found in the literature, which opens the door to future studies to determine the feasibility of the use of the ACS in the treatment of degenerative OA that affects TMJ.

Key words:Osteoarthritis, temporomandibular joint, autologous conditioned serum.

Autologous conditioned serum for the treatment of osteoarthritis and other possible applications in musculoskeletal disorders

INTRODUCTION

The therapeutic use of interleukin 1 (IL-1) cytokine receptor antagonists (IL-1RA) has promoted the development of new biological therapies for osteoarthritis (OA). Autologous conditioned serum (ACS) is an alternative, safe and well-tolerated treatment in OA. Sources of data We performed a comprehensive search of PubMed, Medline, Cochrane, CINAHL, Embase, SportDiscus, Pedro and Google scholar databases using keywords such as 'interleukin 1', 'osteoarthritis' and 'autologous conditioned serum'.

AREAS OF AGREEMENT

ACS, containing endogenous anti-inflammatory cytokines including IL-1RA and several growth factors, could reduce pain and increase function and mobility in mild to moderate knee OA. AREA OF CONTROVERSY: Given the limited data available on the composition of ACS, the mechanisms through which ACS produces clinical improvement, the duration of its effect and the changes in cytokine levels after repeated injections are still unknown. Growing points Although previous clinical data are encouraging and confirm the safety of this modality, given the limitations of current studies, there should be additional, controlled trials to further confirm efficacy for the use of ACS in OA treatment. AREA TIMELY FOR DEVELOPING RESEARCH: ACS can lead to enhancement of tissue regeneration and to reduction of degenerative mechanisms.

Attenuation of osteoarthritis via blockade of the SDF-1/CXCR4 signaling pathway

Introduction

This study was performed to evaluate the attenuation of osteoarthritic (OA) pathogenesis via disruption of the stromal cell-derived factor-1 (SDF-1)/C-X-C chemokine receptor type 4 (CXCR4) signaling with AMD3100 in a guinea pig OA model.

Methods

OA chondrocytes and cartilage explants were incubated with SDF-1, siRNA CXCR4, or anti-CXCR4 antibody before treatment with SDF-1. Matrix metalloproteases (MMPs) mRNA and protein levels were measured with real-time polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. The 35 9-month-old male Hartley guinea pigs (0.88 kg ± 0.21 kg) were divided into three groups: AMD-treated group (n = 13); OA group (n = 11); and sham group (n = 11). At 3 months after treatment, knee joints, synovial fluid, and serum were collected for histologic and biochemical analysis. The severity of cartilage damage was assessed by using the modified Mankin score. The levels of SDF-1, glycosaminoglycans (GAGs), MMP-1, MMP-13, and interleukin-1 (IL-1β) were quantified with ELISA.

Results

SDF-1 infiltrated cartilage and decreased proteoglycan staining. Increased glycosaminoglycans and MMP-13 activity were found in the culture media in response to SDF-1 treatment. Disrupting the interaction between SDF-1 and CXCR4 with siRNA CXCR4 or CXCR4 antibody attenuated the effect of SDF-1. Safranin-O staining revealed less cartilage damage in the AMD3100-treated animals with the lowest Mankin score compared with the control animals. The levels of SDF-1, GAG, MMP1, MMP-13, and IL-1β were much lower in the synovial fluid of the AMD3100 group than in that of control group.

Conclusions

The binding of SDF-1 to CXCR4 induces OA cartilage degeneration. The catabolic processes can be disrupted by pharmacologic blockade of SDF-1/CXCR4 signaling. Together, these findings raise the possibility that disruption of the SDF-1/CXCR4 signaling can be used as a therapeutic approach to attenuate cartilage degeneration.

Intraarticular application of autologous conditioned serum (ACS) reduces bone tunnel widening after ACL reconstructive surgery in a randomized controlled trial

PURPOSE

Pro-inflammatory cytokines play a pivotal role in osteoarthritis, as well as in bone tunnel widening after ACL reconstructive surgery. A new treatment option is to administer autologous conditioned serum (ACS) containing endogenous anti-inflammatory cytokines including IL-1Ra and growth factors (IGF-1, PDGF, and TGF-β1, among others) in the liquid blood phase. The purpose of this trial was to establish whether the postoperative outcome could be affected by intraarticular application of ACS.

METHODS

In a prospective, randomized, double-blinded, placebo-controlled trial with two parallel groups, 62 patients were treated. Bone tunnel width was measured by CT scans, while clinical efficacy was assessed by patient-administered outcome instruments (WOMAC, IKDC 2000) up to 1 year following the ACL reconstruction in patients receiving either ACS (Group A) or placebo (Group B). We compared the levels and dynamics of IL-1β concentrations in the synovial liquid and examined the correlation between the levels of IL-1β at three different postoperative points.

RESULTS

Bone tunnel enlargement was significantly less (6 months: 8%, 12 months: 13%) in Group A than in Group B (6 months: 31%, 12 months: 38%). Clinical outcomes (WOMAC, IKDC 2000) were consistently better in patients treated with ACS at all data points and for all outcome parameters, and there were statistically significant differences in the WOMAC stiffness subscale after 1 year. The decrease in IL-1β synovial fluid concentration was more pronounced in the ACS group, and values were lower, to a statistically significant degree, in the ACS group at day 10.

CONCLUSION

The intraarticular administration/injection of ACS results in decreased bone tunnel widening after ACL reconstructive surgery.

Response of human engineered cartilage based on articular or nasal chondrocytes to interleukin-1β and low oxygen

Previous studies showed that human nasal chondrocytes (HNC) exhibit higher proliferation and chondrogenic capacity as compared to human articular chondrocytes (HAC). To consider HNC as a relevant alternative cell source for the repair of articular cartilage defects it is necessary to test how these cells react when exposed to environmental factors typical of an injured joint. We thus aimed this study at investigating the responses of HNC and HAC to exposure to interleukin (IL)-1β and low oxygen. For this purpose HAC and HNC harvested from the same donors (N=5) were expanded in vitro and then cultured in pellets or collagen-based scaffolds at standard (19%) or low oxygen (5%) conditions. Resulting tissues were analyzed after a short (3 days) exposure to IL-1β, mimicking the initially inflammatory implantation site, or following a recovery time (1 or 2 weeks for pellets and scaffolds, respectively). After IL-1β treatment, constructs generated by both HAC and HNC displayed a transient loss of GAG (up to 21.8% and 36.8%, respectively) and, consistently, an increased production of metalloproteases (MMP)-1 and -13. Collagen type II and the cryptic fragment of aggrecan (DIPEN), both evaluated immunohistochemically, displayed a trend consistent with GAG and MMPs production. HNC-based constructs exhibited a more efficient recovery upon IL-1β withdrawal, resulting in a higher accumulation of GAG (up to 2.6-fold) compared to the corresponding HAC-based tissues. On the other hand, HAC displayed a positive response to low oxygen culture, while HNC were only slightly affected by oxygen percentage. Collectively, under the conditions tested mimicking the postsurgery articular environment, HNC retained a tissue-forming capacity, similar or even better than HAC. These results represent a step forward in validating HNC as a cell source for cartilage tissue engineering strategies.

Engineered cartilage maturation regulates cytokine production and interleukin-1β response

BACKGROUND

Because the injured joint has an actively inflammatory environment, the survival and repair potential of cartilage grafts may be influenced by inflammatory processes. Understanding the interactions of those processes with the graft may lead to concepts for pharmacologic or surgical solutions allowing improved cartilage repair.

QUESTIONS/PURPOSES

We asked whether the maturation level of cartilaginous tissues generated in vitro by expanded human articular chondrocytes (HACs) modulate (1) the spontaneous production of cytokines and (2) the response to interleukin (IL)-1β.

METHODS

Twelve pellets/donor prepared with monolayer-expanded HACs (n = 6 donors) were evaluated at six different culture times for mRNA expression (n = 72) and spontaneous baseline release of monocyte chemoattractant protein (MCP)-1, IL-8, and transforming growth factor (TGF)-β1 (n = 72). We cultured 24 pellets/donor from each of four donors for 1 or 14 days (defined as immature and mature, respectively) and exposed the pellets to IL-1β for 3 days. MCP-1, IL-8, TGF-β1, and metalloprotease (MMP)-1 and MMP-13 were quantified in pellets and culture supernatants.

RESULTS

By increasing culture time, the spontaneous release of IL-8 and MCP-1 decreased (12.0- and 5.5-fold, respectively), whereas that of TGF-β1 increased (5.4-fold). As compared with immature pellets, mature pellets responded to IL-1β by releasing lower amounts of MMP-1 (2.9-fold) and MMP-13 (1.7-fold) and increased levels of IL-8, MCP-1, and TGF-β1 (1.5-, 5.0-, and 7.5-fold, respectively). IL-8 and MCP-1 promptly returned to baseline on withdrawal of IL-1β.

CONCLUSIONS

Our observations suggest more mature cartilaginous tissues are more resistant to IL-1β exposure and can activate chemokines required to initiate tissue repair processes.

CLINICAL RELEVANCE

The implantation of more mature cartilaginous tissues might provide superior graft survival and improve/accelerate cartilage repair.

Novel drug OMS103HP reduces pain and improves joint motion and function for 90 days after arthroscopic meniscectomy

PURPOSE

This phase 2 study compared OMS103HP (Omeros, Seattle, WA) with control (lactated Ringer's) irrigation solution in patients undergoing arthroscopic partial meniscectomy.

METHODS

This was a prospective, multicenter, double-blind, randomized, vehicle-controlled, parallel-group study. Safety and postoperative pain, range of motion, and self-reported function were evaluated for 90 days. Statistical results were based on univariate analysis of variance and repeated-measures analyses.

RESULTS

Mean visual analog scale (VAS) pain scores within 24 hours after discharge from the recovery room showed more pain in the control group beginning at 2 hours and peaking at 8 hours. Univariate analysis of variance of mean VAS scores over the 24-hour period did not meet statistical significance. Repeated-measures analysis yielded a statistically significant difference (P = .004) for time-by-treatment interaction, showing a clear drug benefit over time based on VAS scores. There were statistically significant differences at day 7 between the groups in passive flexion without pain (P = .022). The proportion of patients achieving flexion of 95° or greater, 110°, and 125° was greater for the OMS103HP group. The Knee Injury and Osteoarthritis Outcome Score (KOOS) showed statistically significant differences (P ≤ .05) between the OMS103HP and control groups for 4 of 5 outcomes (symptoms, pain, sport and recreation, and knee-based quality of life but not activities of daily living). All scores showed a treatment effect through day 90. The overall incidence of adverse events and abnormal laboratory values for the OMS103HP and control groups was similar. Serious adverse events occurred in 1 control patient.

CONCLUSIONS

In this study of patients with meniscal tears who underwent simple debridement, the use of OMS103HP resulted in reduced acute postoperative pain (measured by VAS over the first 24 hours postoperatively), reduced pain during recovery (measured by the KOOS pain subscale, which measures both background levels of pain and exacerbations caused by movements or activities), improved postoperative knee motion, and improved functional outcomes as assessed with the KOOS Knee Survey. Clinical benefits of OMS103HP were consistent and sustained throughout 90 days of postoperative follow-up.

LEVEL OF EVIDENCE

Level I, prospective, randomized, controlled trial.

Low Vitamin D Impairs Strength Recovery After Anterior Cruciate Ligament Surgery

The purpose of this study was to identify strength gains after an anterior cruciate ligament injury and surgery and during inflammatory challenge in participants with disparate vitamin D levels. Plasma samples were obtained from those who had not previously experienced an anterior cruciate ligament injury and from injured patients 2 weeks before and 3 months after anterior cruciate ligament surgery. Plasma 25-hydroxyvitamin D and cytokine concentrations were measured in each blood sample. Single-leg peak isometric forces were measured 2 weeks presurgery and 3 months postsurgery. Compared with noninjured participants, inflammatory cytokines were elevated prior to and following anterior cruciate ligament reconstruction. During this inflammatory challenge, the peak isometric force increases after surgery were significantly lower in those with plasma 25-hydroxyvitamin D concentrations <30 ng/mL compared with those with concentrations ≥30 ng/mL. The authors conclude that low vitamin D appears to hinder strength recovery after anterior cruciate ligament surgery and during inflammatory insult.

Does Vitamin E and C Supplementation Improve the Recovery From Anterior Cruciate Ligament Surgery?

Muscular (quadriceps) weakness is a predominant impairment that follows anterior cruciate ligament injury and surgery. This continued weakness impairs activities of daily living and could predispose patients to adverse conditions later in life, such as knee osteoarthritis. Vitamins E and C have potent antioxidant and anti-inflammatory activity. Herein, the authors summarize the state-of-the science and suggest directions for future research endeavors regarding the therapeutic influence of vitamins E and C, or other antioxidants, on the recovery from anterior cruciate ligament injury and surgery.

Intra-articular Anakinra for the Treatment of Persistent Inflammation and Arthrofibrosis following Anterior Cruciate Ligament Reconstruction

Purpose

Postoperative inflammation and arthrofibrosis remain difficult problems following ACL reconstruction. Interleukin-1 (IL-1) is a potent driver of intra-articular inflammation and arthrofibrosis following injury and surgery. Anakinra (Kineret, Amgen, Thousand Oaks, CA) is an IL-1 receptor antagonist. We hypothesize that postoperative intra-articular anakinra use decreases inflammation and subsequent arthrofibrosis, reducing the need for arthroscopic debridement and manipulation under anesthesia.

Methods

Four patients (ages 15-56) who were treated with anakinra for persistent postoperative inflammation and scarring within 4 months of ACL reconstruction were retrospectively reviewed. Anakinra was utilized when patients were unable to obtain full extension and at least 90° of flexion 1 month postoperatively in association with persistent effusions or decreased patellar mobility.

Results

Anakinra injection was performed between 36 and 97 days postsurgery. All four reported improvements in range of motion and decreased pain and effusions within 10 days of injection. One patient, who did not receive anakinra until more than 3 months postsurgery, required eventual arthroscopic debridement of a cyclops lesion but none of the patients required frank lysis of adhesions or manipulation under anesthesia. No adverse reactions to anakinra occurred.

Conclusion

Based on previous experience, we believe that all of these patients would have required arthroscopic debridement of scar tissue and manipulation under anesthesia to regain motion were not for the anakinra treatment. Clearly, the concept of IL-1 inhibition in the postoperative knee requires further research, but early results are promising for this unique treatment of a difficult clinical problem.

Grafted tendon healing in tibial tunnel is inferior to healing in femoral tunnel after anterior cruciate ligament reconstruction: a histomorphometric study in rabbits

PURPOSE

This study aimed to test whether graft healing in the tibial tunnel was inferior to that in the femoral tunnel after anterior cruciate ligament (ACL) reconstruction in rabbits.

METHODS

Surgical reconstruction by use of the digital extensor tendon in the bone tunnel was performed in 18 rabbits. The rabbits were killed at weeks 2, 6, and 12 postoperatively, with 6 at each time point, for histologic examination.

RESULTS

The transiently formed cartilaginous interface was gradually mineralized during re-establishment of direct tendon-to-bone integration, which was observed significantly less in the tibial tunnel than in the femoral tunnel (P < .05). The cell density of the graft was significantly lower in the tibial tunnel than that in the femoral tunnel at weeks 2 and 6 postoperatively (P < .05 for both). An increase in the immature type III collagen content was accompanied by a decrease in graft collagen fiber organization, with healing over time in both the femoral and tibial tunnels. The collagen fiber organization of the graft was significantly poorer in the tibial tunnel than that in the femoral tunnel at week 12 after surgery (P < .05).

CONCLUSIONS

Grafted tendon healing in the tibial tunnel was inferior to that in the femoral tunnel at the tendon-to-bone interface and with regard to the grafted tendon within the bone tunnel after ACL reconstruction in rabbits.

CLINICAL RELEVANCE

Future biopsy study is desirable to test whether this observation was valid clinically, which might provide a scientific basis for therapeutic targets to improve the outcome of ACL surgery.