Background. Collagenase represents a novel non-surgical treatment for Dupuytrens disease. Xiapex (Injectable collagenase, Pfizer pharmaceuticals) was recently approved by the MHRA for clinical use. The main objective of this study was to assess the proportion of patients with Dupuytrens disease that are suitable for treatment with collagenase and the financial implications of its introduction. Methods. All new patients diagnosed with Dupuytrens disease over a three month period (Sept-Nov) were enrolled into study. Patients were assessed in clinic by a senior surgeon. All patients with a palpable Dupuytrens cord without significant skin tethering were offered collagenase. Comparisons were made with the corresponding quarter in the previous 2 years. Management trends were compared over the three years (2009–11) to identify the impact of collagenase. Cost effectiveness analysis was based on a comparison with costs incurred by a fasiectomy, the most common intervention in the management of Dupuytrens disease. Results. Total number of patient referrals was relatively static over the three years with a range of 269 to 285. 23 (36.9%) of 58 patients received collagenase in the time period it was available. Needle fasiotomies which accounted for 11/76 (14%) procedures in 2009 and 5.2% of procedures in 2010 was not performed once collagenase was available. There was a significant reduction in the number of fasiectomies performed over the three year period. 42% (28/58) of procedures performed were fasiectomies in 2010 this had significantly fallen to 32% (21/58) in 2011. Dermofasiectomies were stable over the three year 17% in 2009 to 13% in 2011 with the introduction of collagenase. Cost effectiveness analysis revealed a significant reduction in cost with collagenase. Conclusions. Upto 40% of patients with established Dupuytrens disease maybe suitable for management with collagenase. This represents a cost-effective, clinically effective non-surgical option in the management of Dupuytrens disease

The collagenase of Clostridium Histolyticum enzyme infiltration is a mini-invasive treatment method for Dupuytren's disease which has emerged in recent years as an alternative to traditional surgery (selective aponeurectomy). Although both treatments are effective in the long term, a wider use of the enzyme is spreading worldwide. Indications and protocol of administration of collagenase are strictly regulated by the Italian Drug Administration Agency (AIFA). In the present study an off-label use of this medication has been experienced, in terms of wider indications and more numerous infiltration sites in the same cord (Multipoint technique) and in additional cords affecting other digits (Multicord technique). All patients suffering from Dupuytren's disease and accessing the Hand Surgery outpatient at Rizzoli Institute were considered for the study, between february 2014 and february 2016. Inclusion criteria were Dupuytren's disease and a positive tabletop test. The collagenase injection was indicated for degrees of passive extension deficit (PED) higher than AIFA regulations (MCPJoints >50° and PIPJoints >45°). These patients were compared with the same PED subgroup of surgical patients who were treated through aponeurectomy. Since the drug is dispensed in vials of 0.90 mg, but according to the protocol only 0.58 mg are to be infiltrated, the injection of the remaining 0.32 mg that would otherwise remain unused was experienced. Therefore, in patients who had only one pathological cord in the hand, the first point of the cord to be treated was inoculated with 0.58 mg, according to standards, while two additional points were selected along the fibrosis and injected with the remaining 0, 32 mg. This group was compared with patients treated with the traditional 0.58 mg only on a single cord. In patients in whom the presence of more than a single pathological cord was found, the worse lesion was injected with the usual 0.58 mg as by legislation and the second cord was infiltrated with the 0.32 mg residue and the results obtained within the second cord were compared with those achieved with the usual dose of 0.58 mg. The endpoints considered were the perioperative variations of passive extension deficit (PED) and range of motion (ROM), both expressed as degrees. Data were statistically analyzed in order to find any possible significance in the comparison of groups. Comparing the surgical patients with those treated with collagenase, for the same degrees but higher than AIFA reference, both methods showed a reduction of contracture by at least 50% at 30 days and an improvement of ROM (p>0.05), with fewer complications in those treated enzymatically (p<0.01). Infiltrating the whole dose of collagenase (0.90 mg) through the multipoint mode, has enabled an easier handling of the cord at 24 hours post-injection, a reduction in contracture of at least 50% at 30 days allowing a dowstaging of the disease and a better and faster recovery of hand function, than the classic treatment, although these results are not statistically significant (p>0.05). For degrees of contractures within AIFA indications for collagenase, the 0.32 mg dose is sufficient to cause the lysis of a cord with similar results compared to the greater AIFA-recommended dose of 0.58, in terms of all considered endpoints, with no statistically significant difference (p >0.01). This study confirms the success of treatment with collagenase compared to surgical treatment, in terms of efficacy, safety, more rapid recovery and less invasiveness. In addition, through further clinical studies, AIFA regulations can be gradually safely and effectively extended in terms of a progressive widening of indications and modalities including:. Indication to collagenase for PED higher than 50° (MCP joints) or 45° (PIP joints). Multiple injections in the same cord with the whole content of the vial (0.90 mg). Injections in multiple cords with the whole content of the vial (0.90 mg)

Dupuytren's disease is often disabling and traditionally has been managed with various surgical methods, with recurrence rates up to 50 %. Recently clostridial collagenase injection has been licensed for use in the NHS. We prospectively analysed the results of clostridial collagenase injection in 62 patients with varying degrees of Metacarpo phalangeal (MCP) and Proximal interphalangeal (PIP) joint contractures. There were 48 males and 14 females with an average age of 66 years. The average MCPJ and PIPJ deformities were 33 and 17 degrees respectively. Following the infiltration and subsequent manipulation under local anaesthetic and night splinting for 3 months, patients were followed up at 4 weeks and 6 months. Deformities persisted in 5 patients and later required surgical correction. MCPJ deformities were more amenable for correction than PIPJ and in those with recurrence. The average residual deformity was 7 degrees. Common complications include bruising, swelling, pain not responding to routine analgesia, lymphangitis and skin break in some but none required any additional interventions. 14 patients had completed 6 month follow up and there was no recurrence. Subjective assessment through questionnaires revealed high patient satisfaction rate with early return to work within 1 week in most patients. Patients with previous operations preferred injections over operative correction. Collagenase injections are effective in deformity correction with higher satisfaction rate and low morbidity. Early results are encouraging but long term follow up is required to assess recurrence rates

In December 2012 the orthopaedic Hand and wrist unit at Derriford hospital introduced the use of collagenase injections for the treatment of Dupuytrens' contracture, and currently remains the only centre to use it in the southwest peninsula. We present the short term results of our first year of use of the therapy. There was a statistically significant improvement in PEM scores by 1 and 3 months post-treatment (P: 0.0001 and 0.0016 with 95% confidence). Full correction was obtained in 81% of all MCPJ contractures included in the analysis. Success with PIPJ contractures was more limited, however there was still an average correction of 30 degrees achieved. Complications were limited to skin tears, all of which healed at subsequent follow-up, and 2 failures of therapy. We will continue to use this therapy and as experience and expertise build we hope we can improve our outcomes further

This study aimed to determine if the adoption of collagenase treatment is economically viable. Xiapex collagenase was trialled at Gloucestershire Hospitals NHS Trust in 50 patients suitable for fasciectomy, with a palpable cord and up to two affected joints. Retrospective data for contracture angle pre-injection, immediately post-manipulation and at an average 6 weeks (range 2–17) clinic follow up was collected from medical notes. At follow up the post-procedure number of days required for return to activities of daily living (ADLs) and/or work were recorded, along with overall patient satisfaction rating. Complete data was obtained for 43 patients of average age 67 (range 45–82). At follow up 88% had ≤ 20° residual contracture. Average days return to full ADLs was 9 and work was 11. Overall satisfaction was 8.6 out of 10. Xiapex patients required an average 1 hand physiotherapy appointment post-manipulation compared to 6 for fasciectomy, saving £172.20. Total cost for one treatment course, excluding physiotherapy, was £1166 for Xiapex compared to £2801 for palmar fasciectomy and £5352 for digital fasciectomy. The level of contracture after one Xiapex treatment course permitted return of hand function in the majority of patients whose overall treatment course required less financial and hospital resources

Aim. To determine effectiveness of Collagenase Clostridium Histolyticum (CCH) in deformity correction and hand function for patients with Dupuytren's disease. Materials & Methods. Patients with MCPJ contractures with no previous surgery to the same finger were included. Treatment consisted of one Xiapex injection to a prominent pretendinous band as an outpatient procedure. Follow up was arranged at 48 hours, 3 weeks and final follow up > 6 months. Results. 17 patients were included. Of the 21 fingers that were studied 14 were right and 7 were left sided. Average age was 69 years (56–82) and mean deformity was 37.6° (10–70). Mean follow up was 11.6 months (SD – 3.13, range 7–17). Post manipulation under correction of deformity was present in 3 fingers which improved by final follow up (mean 6.7°). Three patients had re-appearance of deformity (mean 6.7°). The remaining patients had complete correction of deformity. All deformities were significantly corrected, average correction 35.7° (p<0.05). Michigan hand questionnaire (MHQ) score improved significantly following correction of deformity (p<0.005). The subsets of MHQ – hand function, activities of daily living, aesthetics and satisfaction scores improved significantly (p<0.005). Conclusion. CCH an effective, minimally invasive option for the treatment of Dupuytren contracture

Study. This is a prospective double blind, placebo controlled trial. Collagenase Clostridium Histolyticum was effective and well tolerated used in well palpable cords of Dupuytren's Contracture. Concurrent fingers treatment with early complications have been reported. Patients reported outcome measures have been obtained. Materials & Method. 143 fingers were treated in 125 patients. Deformity of more than 30° at metacarpo phalangeal joints and more than 20° at proximal interphalangeal joints with well palpable cord were selected in this study. Finger straightening procedure was undertaken at 24–72 hours post injection. Prospectively evaluated for early complications, extent of correction, residual deformity and recurrence rate at 3 years and 6 months follow up. Concurrent fingers were treated without serious side effects. Results. Full correction was achieved in 130 fingers (91%). Residual flexion deformity noted in mainly in PIPJ with flexion 80° or more. At four years follow up, the recurrence rate was noted in Metacarpophalangeal Joints in 4(3%)fingers and Proximal Inter Phalangeal Joints in 12(9%) fingers. Patient reported outcome measures have been collected and expressed high degree of satisfaction. Conclusion. Most local complications resolved within two weeks of the injection. Isolated MPJ deformity is more likely to be corrected fully. Isolated Proximal Interphalangeal Joints and combined Proximal Interphalangeal Joints and Metacarpo Phalangeal Joints contractures are mostly end up in residual flexion. Concurrent finger treatment was uneventful

Introduction. In Europe, injectable collagenase clostridium histolyticum (CCH) is a novel, minimally invasive, non-surgical therapy with efficacy in correcting Dupuytren's contracture (DC). We evaluated the efficacy and tolerability of 5 CCH injections using a protocol designed to follow clinical practice. Methods. This was a 20-center, 9-month, open-label study in which DC patients with primary flexion deformities 20° (100° for MP; 80° for PIP) received 3 CCH (0.58 mg) injections/joint (5 injections/patient) at 30-day intervals. The primary endpoint was clinical success, defined as a reduction in contracture to 5° 30 days after the last injection (“Day 30”). After first injection into a prioritized joint, patients opted to receive up to 2 more injections into the same cord or cords from other affected joints whether or not they achieved clinical success with the first joint. Adverse events (AEs) were monitored. Results. For the primary endpoint, 71% of MP (n=343) and 41% of PIP (n=244) joints showed a reduction in contracture to 5° with CCH injections. Of joints that did not achieve clinical success, 66% of MP (n=100) and 38% of PIP joints (n=144) showed 50% reduction in contracture after CCH. For range of motion (ROM), mean±SD increase from baseline to Day 30 was 33.0±16.2° for MP and 27.5±18.5° for PIP joints. Most commonly reported AEs were localized edema, bruising, pain, swelling, and tenderness; most resolved without intervention. Two serious AEs, deep vein thrombosis in the leg and tendonitis with partial tendon/ligament injury, were deemed possibly and probably related to treatment, respectively. Conclusions. Results from this open-label study, designed to follow clinical practice, provide support for the efficacy of CCH in correcting the flexion deformity of MP/PIP joints caused by DC. Clinical success and ROM improvements were comparable to those observed in randomized, placebo-controlled trials. This study was funded by Auxilium Pharmaceuticals, Inc

Introduction. Injectable collagenase clostridium histolyticum (CCH) is a minimally invasive non-surgical therapy with efficacy in correcting Dupuytren's contracture (DC). In the concurrently run JOINT I and JOINT II studies, designed to follow clinical practice, we evaluated the efficacy of ?5 CCH injections in patients with DC. Methods. JOINT I and II were multicenter, 9-month, open-label studies in which DC patients with primary flexion deformities ?20° received ?3 CCH (0.58 mg) injections/joint (?5 injections/patient) at 30-day intervals into joints prioritized by extent of contracture. After the first injection, patients could opt to receive up to 2 additional injections in same cord or other cords regardless of outcome for the first joint. The primary endpoint was reduction in contracture to ?5° 30 days after the last injection. Data from JOINT I and II were pooled. Results. For the primary endpoint, 70% of MP (371/531) and 37% of PIP (128/348) joints showed a reduction in contracture to ?5° with CCH injections; 42% (223/531) of MP and 20% (69/348) of PIP joints reached success within 7 days of the first injection. Overall, 89% of MP (470/531) and 58% (202/348) of PIP joints showed clinical improvement (ie, ?50% reduction in contracture). Mean±SD percentage changes in contracture were 84±25% for MP joints and 55±41% for PIP joints. The 2 most common treatment-related adverse events (AEs) localized to the injection site were edema peripheral and contusion. Two patients had treatment-related serious AEs (deep vein thrombosis; tendonitis), but no tendon ruptures or systemic reactions were noted. Conclusions. Pooled results from the JOINT studies designed to follow clinical practice, provide support for the efficacy of CCH in correcting DC. Efficacy and safety data from this analysis are comparable to those observed in randomized, placebo-controlled trials

Xiapex is a novel non-surgical intervention for the treatment of Dupuytren's contracture. It comprises a fixed-ratio mixture of two purified collagenolytic enzymes (AUX-I [clostridial type I collegenase] and AUX II [clostridial type II collagenase]) isolated from the medium of Clostridium histolyticum. Xiapex targets the contracture through the injection of enzymes into the pathologic diseased cords.

The objectives of this study were to evaluate the safety and efficacy of Xiapex in patients with Dupuytren's Contracture, the recovery and associated use of health care resources. The study commenced in June 2011 and was completed in 11 months. 15 patients were screened for the study, 12 patients were eligible (10 male:2 female). All 12 patients completed the trial and 2 patients received multiple injections, one had two fingers affected and the other had two joints affected in one finger.

Following screening visit to determine patient suitability, the patient received their first injection usually within 7 days. Xiapex was injected directly into the palpable cord. 24 hours after injection patients were reviewed and a “finger extension procedure” was performed if the cord had not spontaneously ruptured. Patients were then followed up at 7 days, 30 days and 6 months. Assessments at each visits included: Finger Goniometry, Physician and Subject Global Assessment and Satisfaction, Health Care Resource Utilization and URAM (function assessment) and adverse events.

Of the 14 cords injected all ruptured after finger extension. No patient experienced any serious adverse events, but a number of more minor adverse events were recorded including skin tears, pain at injection site, swelling and bruising. At the time of final follow-up recurrence rates were 14%

In conclusion, Xiapex is suitable for appropriately selected patients who are affected by Dupuytren's contractures and who have a well-developed palpable cord.

Objectives

Injectable Bromelain Solution (IBS) is a modified investigational derivate of the medical grade bromelain-debriding pharmaceutical agent (NexoBrid) studied and approved for a rapid (four-hour single application), eschar-specific, deep burn debridement. We conducted an ex vivo study to determine the ability of IBS to dissolve-disrupt (enzymatic fasciotomy) Dupuytren’s cords.

Aims. Mesenchymal stem cells (MSCs) are usually cultured in a normoxic atmosphere (21%) in vitro, while the oxygen concentrations in human tissues and organs are 1% to 10% when the cells are transplanted in vivo. However, the impact of hypoxia on MSCs has not been deeply studied, especially its translational application. Methods. In the present study, we investigated the characterizations of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) in hypoxic (1%) and normoxic (21%) atmospheres with a long-term culture from primary to 30 generations, respectively. The comparison between both atmospheres systematically analyzed the biological functions of MSCs, mainly including stemness maintenance, immune regulation, and resistance to chondrocyte apoptosis, and studied their joint function and anti-inflammatory effects in osteoarthritis (OA) rats constructed by collagenase II. Results. We observed that long-term hypoxic culture surpassed normoxic atmosphere during hUC-MSCs culture in respect of promoting proliferation, anti-tumorigenicity, maintaining normal karyotype and stemness, inhibiting senescence, and improving immunoregulatory function and the role of anti-apoptosis in chondrocytes. Furthermore, we demonstrated that the transplantation of long-term hypoxic hUC-MSCs (Hy-MSCs) had a better therapeutic effect on OA rats compared with the hUC-MSCs cultured in the normoxic atmosphere (No-MSCs) in terms of the improved function and swelling recovery in the joints, and substantially inhibited the secretion of pro-inflammatory factors, which effectively alleviated cartilage damage by reducing the expression of matrix metallopeptidase 13 (MMP-13). Conclusion. Our results demonstrate that Hy-MSCs possess immense potential for clinical applications via promoting stemness maintenance and enhancing immunoregulatory function. Cite this article: Bone Joint Res 2024;13(12):763–777

Tendon-related pathologies such as tendinopathy represent a relevant clinical and socioeconomic issue. The most innovative and conservative therapeutic approaches are meant to stimulate the intrinsic healing capability of the tissue. In this study, the use of pulsed electromagnetic fields (PEMFs) was investigated in a rat model of Achilles tendinopathy as a potential therapy. Achilles tendinopathy was chemically induced in eighty-six Sprague Dawley rats by injecting collagenase Type I within the tendon fibers. Fifty-six of them were stimulated with PEMFs (8 hours/day, 1.5 ± 0.2 mT; 75 Hz), divided in different experimental groups basing on the starting-time of PEMFs exposure (after 0, 7, 15 after Collagenase injection) and its duration (7, 15 or 30 days). Thirty animals were left unstimulated (CTRL group). According to the different time points, explanted tendons were evaluated through histological and immunohistochemical analyses in term of matrix deposition, fiber re-organization, neovascularization and inflammatory reaction. The most effective PEMF stimulation was demonstrated in the 15 days of treatment. However, when PEMF were applied immediately after the collagenase injection, no significant therapeutic results were found. On the contrary, when PEMF were applied after 7 and 15 days from the collagenase injection, they promoted the deposition of extracellular matrix and tendon fiber re-organization, reducing both the inflammatory reaction and vascularization, with significant differences compared to the CTRL group (p<0.05). Therefore, these results suggest an effective activity of PEMFs stimulation that provides a satisfying restoration of the damaged tissue, although the most performing protocol of application still needs to be identified

Introduction and Objective. Guided Bone Regeneration (GBR) uses biodegradable collagen membranes of animal origin tissues (dermis and pericardium). Their barrier effect prevents soft tissues to interfere with the regeneration of alveolar bone. However, their xenogeneic origin involves heavy chemical treatments which impact their bioactivity. Wharton's Jelly (WJ) from the umbilical cord is a recoverable surgery waste. WJ is mostly made from collagen fibers, proteoglycans, hyaluronic acid, and growth factors. WJ with immunologically privileged status and bioactive properties lends credence to its use as an allograft. Nevertheless, low mechanical properties limit its use in bone regenerative strategies. Herein, our objective is to develop a crosslinked WJ-based membrane to improve its strength and thus its potential use as a GBR membrane. Materials and Methods. The umbilical cords are collected after delivery and then stored at −20°C until use. The WJ membranes (1 × 5 × 12 mm) were obtained after the removal of blood vessels and amniotic tissue, washed, lyophilized, and stored at −20°C. WJ membranes were incubated in genipin solutions in decreasing concentrations (0.3 g / 100 mL − 0.03 g / 100 mL) for 24 hours at 37°C. The crosslinking degree was estimated by ninhydrin and confirmed by FTIR (Fourier-transform infrared spectroscopy) assays. The swelling rate was obtained after the rehydration of dry crosslinked WJ-membrane for 10 min in D-PBS. The mechanical properties were assessed in hydrated conditions on a tensile bench. The resistance to the degradation was evaluated by collagenase digestion (1 mg/mL for 60 hours) assay. The cytotoxicity of crosslinked WJ-membrane was evaluated in accordance with the standard ISO.10993-5 (i.e. Mitochondrial activity and Lactate Dehydrogenase release) against Mesenchymal Stem Cells (MSCs). Finally, the MSCs colonization and proliferation were followed after 21 days of culture on crosslinked WJ-membranes. Results. The increase of crosslinking rates from 30% to 90% of the WJ membrane was demonstrated by the ninhydrin assay. FTIR analysis showed a prominent peak at 1732 cm. -1. , confirming the incorporation of genipin in the WJ. The swelling rate of crosslinked WJ-membrane decreased with an increase of the crosslinking rate. An increase in elastic modulus and an increase in the resistance to the collagenase degradation were observed along with an increase in the crosslinking degree. Cytotoxicity investigations did not elicit a harmful effect of the genipin, however, a poor MSCs adhesion on the crosslinked membrane was observed. Conclusions. Our results show that a membrane can be developed from Wharton's jelly. The mechanical and degradation properties can be improved by crosslinking with genipin without inducing any cytotoxicity effect. However, the percentage of crosslinking has an influence on the adhesion of the cells to the membranes. The crosslinked WJ-membrane bioactivity and the osteo-regenerative potential in vitro/in vivo will be evaluate

Introduction and Objective. Osteoarthritis (OA) represents one of the leading cause of disability all over the world. Cell therapies, mainly based on mesenchymal stem cells (MSCs), have shown to modulate the pathogenesis of OA in basic, preclinical and clinical studies. Adipose tissue (AT) have emerged as a rich and promising source of MSCs called adipose derived stem cells (ASCs). Different systems are available for processing lipoaspirate to purify the samples from oily and haemorrhagic fractions, minimizing the risk of complications and maximizing the biological yield for subsequent grafting. However, few studies compared the efficacy of the different processing devices already used in clinical practice. This study aims to characterize the products obtained by the use of two different systems such as micro-fragmentation or nano-fragmentation comparing them with the starting material (AT) and the collagenase isolated ASCs. Materials and Methods. AT from 12 donors arrived without selection to the laboratories: 4 lipoaspirated (LA), 4 micro-fragmented (mF) and 4 nano-fragmented (nF). The samples were divided into three aliquots for paraffin embedding, RNA extraction and digestion with collagenase for ASCs isolation. Paraffin embedded tissue sections were stained with hematoxylin-eosin to analyze morphology. RNA was extracted, retro-transcribed and analyzed with real-time PCR to analyze the expression of pluripotency genes (SOX2, NANOG and POU5F1) and inflammatory genes (IL-1beta and iNOS). Data were analyzed using Graphpad Prism 8.0 and expressed as mean ± SD. One-way ANOVA followed by Tukey test was used to compare the different groups. Results. The LA comprised small lobules, with intact cell membranes and structurally integer adipocytes. mF samples showed the presence of integer adipocytes, small lobules and higher amount of cell clusters. nF samples showed the almost completely absence of adipocytes, a high amount of cells without lipid content and a high amount of stromal matrix. Real-time PCR results showed the lowest expression levels of pluripotency genes in LA samples that were assumed equal to 1.0 and used to calculate the expression levels of the other samples. mF showed expression levels of pluripotency genes similar to AT. nF showed expression levels of pluripotency genes higher than AT and mF, but without statistically significant differences. ASCs showed statistically significant higher expression levels of these genes compared to LA and mF (p ≤ 0.001). Likewise, the expression of inflammatory genes resulted to be lowest in LA samples (assumed equal to 1.0), higher in mF samples and in nF samples without statistical significance. As expected, the highest values were found in ASCs isolated cells compared to all the other samples (p ≤ 0.0001). Conclusions. These results confirmed that micro-fragmentation (mF) and nano-fragmentation (nF) permitted to separate a cell mixture enriched in ASCs from a lipoaspirate sample without activating the inflammatory pathways. Both processing methods gave a minimally manipulated product suitable for OA cell therapy application. Further studies are needed to elucidate possible different activities of the ASCs enriched AT-derivatives

Objectives. Recent studies have shown that systemic injection of rapamycin can prevent the development of osteoarthritis (OA)-like changes in human chondrocytes and reduce the severity of experimental OA. However, the systemic injection of rapamycin leads to many side effects. The purpose of this study was to determine the effects of intra-articular injection of Torin 1, which as a specific inhibitor of mTOR which can cause induction of autophagy, is similar to rapamycin, on articular cartilage degeneration in a rabbit osteoarthritis model and to investigate the mechanism of Torin 1’s effects on experimental OA. Methods. Collagenase (type II) was injected twice into both knees of three-month-old rabbits to induce OA, combined with two intra–articular injections of Torin 1 (400 nM). Degeneration of articular cartilage was evaluated by histology using the Mankin scoring system at eight weeks after injection. Chondrocyte degeneration and autophagosomes were observed by transmission electron microscopy. Matrix metallopeptidase-13 (MMP-13) and vascular endothelial growth factor (VEGF) expression were analysed by quantitative RT-PCR (qPCR).Beclin-1 and light chain 3 (LC3) expression were examined by Western blotting. Results. Intra-articular injection of Torin 1 significantly reduced degeneration of the articular cartilage after induction of OA. Autophagosomes andBeclin-1 and LC3 expression were increased in the chondrocytes from Torin 1-treated rabbits. Torin 1 treatment also reduced MMP-13 and VEGF expression at eight weeks after collagenase injection. Conclusion. Our results demonstrate that intra-articular injection of Torin 1 reduces degeneration of articular cartilage in collagenase-induced OA, at least partially by autophagy activation, suggesting a novel therapeutic approach for preventing cartilage degeneration and treating OA. Cite this article: N-T. Cheng, A. Guo, Y-P. Cui. Intra-articular injection of Torin 1 reduces degeneration of articular cartilage in a rabbit osteoarthritis model. Bone Joint Res 2016;5:218–224. DOI: 10.1302/2046-3758.56.BJR-2015-0001

Osteoprogenitors on the inner layer of periosteum are the major cellular contributors to appositional bone growth and bone repair by callus formation. Previous work showed that periosteal-derived cells have little or no osteogenic activity under standard in vitro osteogenic culture conditions. This study was conducted to determine what growth factor(s) can activate periosteal osteogenic capacity. This study was conducted with IACUC approval. Periosteum from five equine donors was digested in collagenase for 3-4 hours at 37C. Isolated periosteal cells were maintained in DMEM/10% FBS medium and exposed to PDGF, Prostaglandin E2, BMP-2 and TGF-b3 at a range of concentrations for 72 hours. Changes in osteogenic gene expression (Runx2, OSX and ALP) were measured by qPCR. Periosteal cells were pre-treated with TGF-b3 or maintained in control medium were transferred into basal or osteogenic medium. Osteogenic status was assessed by Alizarin Red staining for mineralized matrix, ALP enzymatic activity and induction of osteogenic genes. PDGF, PgE2 and BMP-2 had little impact on expression of osteogenic markers by periosteal cells. In contrast, TGF-b3 stimulated significant increases in Osterix (over 100-fold) ALP expression (over 70-fold). Pre-treating periosteal cells with TGF-b3 for 72 hours stimulated rapid cell aggregation and aggregate mineralization once cells were transferred to osteogenic medium, while cells not exposed to TGF-b3 exhibited minimal evidence of osteogenic activity. This study indicate that TGF-b signaling is vital for periosteal osteogenic activity. Transient ‘priming’ of periosteal cells through TGF-b exposure was sufficient to activate subsequent osteogenesis without requiring ongoing growth factor stimulation. TGF beta ligands are secreted by many cell types, including periosteal progenitors and osteocytes, providing opportunities for both autocrine and paracrine pathways to regulate periosteal bone formation under homeostatic and reparative conditions

Depletion of Scleraxis-lineage (ScxLin) cells in adult tendon recapitulates age-related decrements in cell density, ECM organization and composition. However, depletion of ScxLin cells improves tendon healing, relative to age-matched wildtype mice, while aging impairs healing. Therefore, we examined whether ScxLin depletion and aging result in comparable shifts in the tendon cell environment and defined the intrinsic programmatic shifts that occur with natural aging, to define the key regulators of age-related healing deficits. ScxLin cells were depleted in 3M-old Scx-Cre+; Rosa-DTRF/+ mice via diphtheria toxin injections into the hindpaw. Rosa-DTRF/+ mice were used as wildtype (WT) controls. Tendons were harvested from 6M-old ScxLin depleted and WT mice, and 21-month-old (21M) C57Bl/6 mice (aged). FDL tendons (n=6) were harvested for single-cell RNAseq, pooled, collagenase digested, and sorted for single cell capture. Data was processed using Cell Ranger and then aligned to the annotated mouse genome (mm10). Filtering, unsupervised cell clustering, and differential gene expression (DEG) analysis were performed using Seurat. Following integration and sub-clustering of the tenocyte populations, five distinct subpopulations were observed. In both ScxLin depletion and aging, ‘ECM synthesizers’ and ‘ECM organizers’ populations were lost, consistent with disruptions in tissue homeostasis and altered ECM composition. However, in ScxLin depleted mice retention of a ‘specialized ECM remodeler’ population was observed, while aging tendon cells demonstrated inflammatory skewing with retention of a ‘pro-inflammatory tenocyte population’. In addition, enrichment of genes associated with protein misfolding clearance were observed in aged tenocytes. Finally, a similar inflammatory skewing was observed in aged tendon-resident macrophages, with this skewing not observed in ScxLin depleted tendons. These data suggest that loss of ‘ECM synthesizer’ populations underpins disruptions in tendon homeostasis. However, retention of ‘specialized remodelers’ promotes enhanced healing (ScxLin depletion), while inflammatory skewing may drive the impaired healing response in aged tendons

Aims. In the context of tendon degenerative disorders, the need for innovative conservative treatments that can improve the intrinsic healing potential of tendon tissue is progressively increasing. In this study, the role of pulsed electromagnetic fields (PEMFs) in improving the tendon healing process was evaluated in a rat model of collagenase-induced Achilles tendinopathy. Methods. A total of 68 Sprague Dawley rats received a single injection of type I collagenase in Achilles tendons to induce the tendinopathy and then were daily exposed to PEMFs (1.5 mT and 75 Hz) for up to 14 days - starting 1, 7, or 15 days after the injection - to identify the best treatment option with respect to the phase of the disease. Then, 7 and 14 days of PEMF exposure were compared to identify the most effective protocol. Results. The daily exposure to PEMFs generally provided an improvement in the fibre organization, a decrease in cell density, vascularity, and fat deposition, and a restoration of the physiological cell morphology compared to untreated tendons. These improvements were more evident when the tendons were exposed to PEMFs during the mid-acute phase of the pathology (7 days after induction) rather than during the early (1 day after induction) or the late acute phase (15 days after induction). Moreover, the exposure to PEMFs for 14 days during the mid-acute phase was more effective than for 7 days. Conclusion. PEMFs exerted a positive role in the tendon healing process, thus representing a promising conservative treatment for tendinopathy, although further investigations regarding the clinical evaluation are needed. Cite this article: Bone Joint Res 2020;9(9):613–622

Summary:. Hamstring tendons (HT) represent a widely used autograft for ACL reconstruction. Harvesting, processing and pretensioning procedures together with the time out of the joint could theoretically hamper tendon cells (TCs) viability. The authors hypothesize that HT cells are not impaired at the end of the surgical procedures and their tenogenic phenotype may be strongly improved by exposure to PEMF. Methods. Remnants of semitendinosus and gracilis tendons were collected at the end of the surgical procedures before skin closure from 15 healthy donors who underwent ACL reconstruction with autologous hamstring tendons. To isolate TCs, the tendon was minced and digested with 0.3 % type I collagenase and the nucleated cells were plated at a density 5x10E3 cells/cm2 and cultured in chamber slides in differentiation medium composed of DMEM + 5ng/ml basic fibroblast growth factor (b-FGF) for 7, 14, 21 days. The following cell cultures were set up:. -. TCs cultured with differentiation medium + exposure to PEMF 8 h/day (PEMF generator system IGEA, intensity of magnetic field = 1.5 mT, frequency = 75 Hz). -. TCs cultured with differentiation medium without exposure to PEMF. At day 0, day 7, day 14 and day 21, immunofluorescence analysis was performed to evaluate the expression of collagen type I, collagen type VI, scleraxis and PCNA (proliferative marker). Subsequently, tendon explant cultures were set up to verify, at day 21, explant viability and the expression of collagen type I, collagen type VI, beta-catenin and PCNA. Results. The TCs from the tendon fragments at the end of the ACL reconstruction were alive and they expressed markers of proliferation and tendon phenotype at the end of the culture periods. The TCs in the presence PEMF 8h/day showed greater production of collagen type I, collagen type VI and scleraxis than that of TCs cultured without PEMF (p<0,05): the expression of this markers increased from 7 to 21 days of culture. The expression of PCNA, in the presence of PEMF stimulus, was significantly lower (p<0,05) than that of TCs cultured without PEMF. A similar behavior was surprisingly observed in tendon explant cultures. Conclusions. Hamstring tendons used for ACL reconstruction are not simple autologous tenoconductive scaffold but are a biologic structure rich in progenitor cells that show tenogenic behavior. Their tenogenic phenotype may be strongly improved by exposure to PEMF. In a future clinical perspective, the postoperative use of PEMF could be used to enhance the ligamentization processes of autologous hamstring tendons, when used as autografts for ACL reconstructions