Subchondral Plate Research Articles

Progression of Bone Marrow Lesions and the Development of Knee Osteoarthritis: Osteoarthritis Initiative Data.

Background Bone marrow lesions (BMLs) are a known risk factor for incident knee osteoarthritis (OA), and deep learning (DL) methods can assist in automated segmentation and risk prediction. Purpose To develop and validate a DL model for quantifying tibiofemoral BML volume on MRI scans in knees without radiographic OA and to assess the association between longitudinal BML changes and incident knee OA. Materials and Methods This retrospective study included knee MRI scans from the Osteoarthritis Initiative prospective cohort (February 2004-October 2015). The DL model, developed between August and October 2023, segmented the tibiofemoral joint into 10 subregions and measured BML volume in each subregion. Baseline and 4-year follow-up MRI scans were analyzed. Knees without OA at baseline were categorized into three groups based on 4-year BML volume changes: BML-free, BML regression, and BML progression. The risk of developing radiographic and symptomatic OA over 9 years was compared among these groups. Results Included were 3869 non-OA knees in 2430 participants (mean age, 59.5 years ± 9.0 [SD]; female-to-male ratio, 1.3:1). At 4-year follow-up, 2216 knees remained BML-free, 1106 showed an increase in BML volume, and 547 showed a decrease in BML volume. BML progression was associated with a higher risk of developing radiographic knee OA compared with remaining BML-free (hazard ratio [HR] = 3.0; P < .001) or BML regression (HR = 2.0; P < .001). Knees with BML progression also had a higher risk of developing symptomatic OA compared with BML-free knees (HR = 1.3; P < .001). Larger volume changes in BML progression were associated with a higher risk of developing both radiographic OA (HR = 2.0; P < .001) and symptomatic OA (HR = 1.7; P < .001). In almost all subchondral plates, especially the medial femur and tibia, BML progression was associated with a higher risk of developing both radiographic and symptomatic OA compared with remaining BML-free. Conclusion Knees with BML progression, according to subregion and extent of volume changes, were associated with an increased risk of OA compared with BML-free knees and knees with BML regression, highlighting the potential utility of monitoring BML volume changes in evaluating interventions to prevent OA development. ClinicalTrials.gov Identifier: NCT00080171 © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Said and Sakly in this issue.

Histological and Histopathological Features of the Third Metacarpal/Tarsal Parasagittal Groove and Proximal Phalanx Sagittal Groove in Thoroughbred Horses with Racing History.

Information regarding the histopathology of the proximal phalanx (P1) sagittal groove in racehorses is limited. Twenty-nine cadaver limbs from nine Thoroughbred racehorses in racing/race-training underwent histological examination. Histological specimens of the third metacarpal/metatarsal (MC3/MT3) parasagittal grooves and P1 sagittal grooves were graded for histopathological findings in hyaline cartilage (HC), calcified cartilage (CC), and subchondral plate and trabecular bone (SCB/TB) regions. Histopathological grades were compared between (1) fissure and non-fissure locations observed in a previous study and (2) dorsal, middle, and palmar/plantar aspects. (1) HC, CC, and SCB/TB grades were more severe in fissure than non-fissure locations in the MC3/MT3 parasagittal groove (p < 0.001). SCB/TB grades were more severe in fissure than non-fissure locations in the P1 sagittal groove (p < 0.001). (2) HC, CC, and SCB/TB grades including SCB collapse were more severe in the palmar/plantar than the middle aspect of the MC3/MT3 parasagittal groove (p < 0.001). SCB/TB grades including SCB collapse were more severe in the dorsal and middle than the palmar/plantar aspect of the P1 sagittal groove (p < 0.001). Histopathology in the SCB/TB region including bone fatigue injury was related to fissure locations, the palmar/plantar MC3/MT3 parasagittal groove, and the dorsal P1 sagittal groove.

First Metatarsophalangeal Joint Arthrodesis With Complete Resection of the Subchondral Bone Plate

First metatarsophalangeal arthrodesis is associated with high union rates but there is a wide range of union incidence reported. Whether the subchondral plate is completely resected, is not reported by individual studies and without meticulous care, there is often residual subchondral plate. The primary aim was to report our union rate following first metatarsophalangeal arthrodesis with complete resection of the subchondral plate, locking plate fixation and immediate protected weight bearing. A retrospective case study of 2 surgeons was performed from August 2016 to June 2023. Our study was unique in that all patients had complete resection of the subchondral plate to trabecular bone. One hundred seventeen feet were identified for analysis, in 112 patients following exclusion criteria. Patients were excluded if they had less than 3 months follow-up, revisional surgery or charcot. Demographic data and indications for the procedure were reported. A single construct locking plate with an interfragmentary compression screw through the plate was used in 37 feet and a locking plate with separate interfragmentary compression screw was used in 80 feet. We reported a nonunion incidence of 0.9% (n = 1) with a delayed union incidence of 0.9% (n = 1) and a broken hardware incidence of 0.9% (n = 1). Complete resection of subchondral plate with early weight bearing and locking plate fixation had a high union rate for first metatarsophalangeal arthrodesis. Our results compare favorably with union rates in the literature, where there is often residual subchondral plate.

Surgical Management of Osteochondritis Dissecans of the Glenoid via Autologous Bone Marrow Aspirate Concentrate and Extracellular Matrix Graft in an Eighteen-Year-Old College Pitcher

Background: Osteochondritis dissecans (OCD) affects the shoulder in only 0.6% of patients aged 2 to 19 years with disease most commonly in the humeral head. When the glenoid is affected, it is often in male overhead throwing athletes and treated with fixation via autologous osteochondral plugs following bone marrow aspirate. Indications: The primary indication for surgical management of OCD is failure of conservative management, often with imaging showing disruption of the glenoid subchondral plate. This patient is an 18-year-old male pitcher with over 2 years of chronic, deep-seated shoulder pain unresponsive to conservative management. Technique Description: We present a primary arthroscopic technique of autologous bone marrow aspirate concentrate graft for management of OCD in an 18-year-old college baseball pitcher. The patient was placed in the left lateral decubitus position with an axillary roll and standard portals were established. A loose fragmented flap with no underlying osseous material was debrided and a 3-cm central area of bony loss was identified. Bone marrow aspirate of 80 mL was taken from the anterior superior iliac crest. The aspirate was mixed with Biocartilage (Arthrex) to fill the defect flush with the surrounding tissue and sealed with fibrin glue. Ports were closed and an abduction sling was applied. Results: A recent review article demonstrated that athletes who underwent surgical management of OCD lesions returned to sports an average of 1.2 months sooner than those managed non-operatively, though this difference was not significant. This patient had a full return to play at 9 months. At 1-year follow-up, he made a full recovery and is currently playing professionally without shoulder pain. Discussion/Conclusion: Autologous bone marrow aspirate defect filling is a viable treatment of OCD, even in high-level overhead throwing athletes. It allows for arthroscopic treatment with long-term success in the treatment of pain and function. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Endoscopic Sequential Decompression of Avascular Necrosis of the Femoral Head of Nontraumatic Origin: Description of a Surgical Technique

Introduction: Treatment options for nontraumatic avascular necrosis of the femoral head (NAVNT) aim to reduce intraosseous pressure and restore vascular flow to prevent the collapse of the femoral head. The objective of this study was to describe a modification of the standard central decompression technique, called sequential decompression, in patients with NAVNT. Materials and Methods: Sequential decompression consists of 4 stages: (1) negative pressure release with capsulotomy, (2) bone decompression by removing the cortical from the anterior superior part of the femoral head-neck junction, (3) intramedullary decompression and stimulation of osteogenesis through tunnels from the anterolateral aspect of the femoral neck, and (4) stimulation of angiogenesis with the application of platelet-rich plasma in the subchondral plate. Results: Five cases (4 men and 1 woman, age: 28.8±16.4 y) were treated with the sequential decompression technique. A decrease in pain and an improvement in function were observed in all cases. Conclusion: We believe that the approach offered by sequential decompression impacts the different pathophysiological pathways of NAVNT, which helps control intraosseous pressure, removal of necrotic tissue, stimulation of angiogenesis, and bone regeneration. Level of Evidence: Level V, expert opinion.

Subchondral Insufficiency Fractures of the Knee: A Clinical Narrative Review.

» Subchondral insufficiency fractures of the knee (SIFKs) are subchondral plate fractures with a prevalence of 2% to 4% of all knee injuries.» Magnetic resonance imaging is the gold standard for evaluating SIFK, while plain radiographs have limited the use in the diagnosis of SIFK.» Among patients with SIFK, 50% to 100% have meniscal pathology.» Medical therapies and standard treatments traditionally used in the management of knee osteoarthritis differ from recommended management of SIFK patients.» Randomized controlled trials and cohort studies with long-term follow-up are needed to determine the optimal rehabilitation protocol, interventional therapy, and prognosis of SIFK patients.

192 Preserving Glenoid Subchondral Bone in aTSR

Abstract Aim Glenoid loosening remains a major concern in anatomical Total Shoulder Replacement (aTSR). Preoperative planning software and patient specific guides allow implantation optimization in aTSR. This study aims to examine and compare the amount of bone resected with prescribed adjusted angles to respecting the subchondral plate with minimal resection, using a freehand technique. Method Two groups of shoulder CT scans were assessed, normal and osteoarthritic of patients who had undergone aTSR. Preoperative planning software was used to place the glenoid component in prescribed adjusted angles, with neutral (0o,0o), retroverted (-10o,0o) and inclined alignment (0o,10o). This was then compared to positioning the component using a freehand technique, whereby the component was placed in a position to maintain the subchondral plate with minimal bone loss and respecting the integrity of the vault. Results The number of CT scans was 68, 34 normal and 34 osteoarthritic. The freehand technique resulted in statistically superior cortical bone seating in the osteoarthritic group with a mean (standard deviation) of 53.27% (14.32), while neutral alignment resulted in 36.68% (10.81), retroversion 40.40% (13.06), and inclination 39.34% (13.52), p&amp;lt;0.001. Similarly in the normal scans, cortical bone seating in the freehand scenario was 46.71% (15.96), neutral 25.65% (12.27), retroverted 26.73% (15.03), and inclined 32.93% (12.12), p&amp;lt;0.001. Conclusions The freehand method for positioning the guidewire resulted in significantly superior cortical bone seating, when compared to prescribed adjusted angles. Applying this technique in the clinical setting may achieve superior glenoid component seating and hence reduce the risk of aseptic loosening in aTSR.

Protective effect of vaginal resveratrol administration on joint tissues in ovariectomized rats: Targeting mTOR and сaspase 3

IntroductionEstrogens play a considerable role in maintaining bone and articular cartilage homeostasis. Menopause provokes joint disorders due to metabolic syndrome and altered signaling pathways. Phytoestrogen resveratrol was demonstrated to provide chondroprotective and osteoprotective effects. However, the mechanisms of such action of Resveratrol are still being explored. AimThe study aims to determine the effect of Resveratrol on the joints and its therapeutic mechanism in ovariectomized rats. Material and methodsThe study was carried out on Wistar female rats that were divided into three groups, including control animals; ovariectomized rats (OVX); and the OVX group treated with an intravaginal gel containing Resveratrol (0.5 % 0.1 mL, daily 28 days). Knee joint tissues (articular cartilage, subchondral plate, subchondral bone) were assessed by histomorphometry. The expression of mTOR, PTEN, Caspase 3 and BCL-2 in articular cartilage and subchondral bone were evaluated immunohistochemically. ResultsResveratrol treatment of OVX rats prevented weight gain by 17 % (P < 0.001), demonstrating the systemic effect on metabolic pathways. Although there were no statistically significant differences in the thickness of articular cartilage between groups, OVX rats possessed degenerative changes in chondrocytes, associated with the enhanced expression of mTOR (P < 0.001) and Casp-3 (P = 0.005). Resveratrol decreased mTOR (P = 0.007) and Casp-3 (P = 0.011) expression in chondrocytes, reducing degenerative changes. At the same time, resveratrol attenuated the deterioration of trabecular bone in OVX rats (P = 0.002). This effect was through the up-regulation of BCL-2 (P = 0.018) and down-regulation of Casp-3 expression (P < 0.001). ConclusionsIntravaginal administration of resveratrol provided systemic effects and ameliorated joint tissue structure and signaling in OVX rats through stimulation of BCL-2 and reduced Casp-3 expression.

Irisin Protects against Loss of Trabecular Bone Mass and Strength in Adult Ovariectomized Mice by Stimulating Osteoblast Activity.

Irisin is a peptide secreted by skeletal muscle that plays a major role in bone metabolism. Experiments in mouse models have shown that administration of recombinant irisin prevents disuse-induced bone loss. In this study, we aimed to evaluate the effects of irisin treatment for the prevention of bone loss in the ovariectomized (Ovx) mouse, the animal model commonly used to investigate osteoporosis caused by estrogen deficiency. Micro-Ct analysis conducted on Sham mice (Sham-veh) and Ovx mice treated with vehicle (Ovx-veh) or recombinant irisin (Ovx-irisn) showed bone volume fraction (BV/TV) decreases in femurs (Ovx-veh 1.39± 0.71 vs. Sham-veh 2.84 ± 1.23; p = 0.02) and tibia at both proximal condyles (Ovx-veh 1.97 ± 0.68 vs. Sham-veh 3.48 ± 1.26; p = 0.03) and the subchondral plate (Ovx-veh 6.33 ± 0.36 vs. Sham-veh 8.18 ± 0.41; p = 0.01), which were prevented by treatment with a weekly dose of irisin for 4 weeks. Moreover, histological analysis of trabecular bone showed that irisin increased the number of active osteoblasts per bone perimeter (Ovx-irisin 32.3 ± 3.9 vs. Ovx-veh 23.5 ± 3.6; p = 0.01), while decreasing osteoclasts (Ovx-irisin 7.6 ± 2.4 vs. Ovx-veh 12.9 ± 3.04; p = 0.05). The possible mechanism by which irisin enhances osteoblast activity in Ovx mice is upregulation of the transcription factor Atf4, one of the key markers of osteoblast differentiation, and osteoprotegerin, thereby inhibiting osteoclast formation.

Comparison of Intermediate-Term Clinical Outcomes Between Medial and Lateral Osteochondral Lesions of the Talus Treated With Autologous Osteochondral Transplantation.

The conventional operative method to treat an osteochondral lesion of the talus (OLT) is through bone marrow stimulation (BMS). Autologous osteochondral transplantation (AOT) is being used as an alternative option in cases with a large OLT, accompanying subchondral cyst, and/or failed BMS. We aimed to compare the intermediate-term clinical and radiologic results between medial and lateral OLTs after an AOT procedure. Among the patients who underwent AOT, 45 cases with at least 3 years' follow-up were included in this retrospective study. We had 15 cases of lateral lesions and selected 30 cases of medial lesions matched for age and gender. Lateral lesions were resurfaced without an osteotomy; medial lesion resurfacing was combined with a medial malleolar osteotomy. Clinical assessment was performed using the Foot and Ankle Outcome Score (FAOS) and Foot and Ankle Ability Measure (FAAM). Radiographic assessment included the irregularity of articular surface (subchondral plate), the progression of degenerative arthritis, and the change of the talar tilt. The mean FAOS and FAAM scores significantly improved after surgery in both groups. Up to 1 year postoperatively, there was significant difference in FAAM scores between the both groups (mean 75.3 points in medial group and 87.2 points in lateral group, P < .001). Delayed union or malunion of the malleolar osteotomy was found in 4 cases (13%) in the medial group. In addition, the progression of joint degeneration was observed in 3 cases (10%) in the medial group. There were no significant differences in the irregularity of articular surface and the change of talar tilt between both groups. A comparison between medial and lateral OLTs treated with AOT demonstrated comparable intermediate-term clinical outcomes. However, patients with medial OLT required a longer period to restore ability for daily and sport activities. In addition, we found more complications and higher rate of progression in the radiologic arthritis grade after medial malleolar osteotomy. Level IV, retrospective comparative study.

Promotion of Joint Degeneration and Chondrocyte Metabolic Dysfunction by Excessive Growth Hormone in Mice.

Many patients with acromegaly, a hormonal disorder with excessive growth hormone (GH) production, report pain in joints. We undertook this study to characterize the joint pathology of mice with overexpression of bovine GH (bGH) or a GH receptor antagonist (GHa) and to investigate the effect of GH on regulation of chondrocyte cellular metabolism. Knee joints from mice overexpressing bGH or GHa and wild-type (WT) control mice were examined using histology and micro-computed tomography for osteoarthritic (OA) pathologies. Additionally, cartilage from bGH mice was used for metabolomics analysis. Mouse primary chondrocytes from bGH and WT mice, with or without pegvisomant treatment, were used for quantitative polymerase chain reaction and Seahorse respirometry analyses. Both male and female bGH mice at ~13 months of age had increased knee joint degeneration, which was characterized by loss of cartilage structure, expansion of hypertrophic chondrocytes, synovitis, and subchondral plate thinning. The joint pathologies were also demonstrated by significantly higher Osteoarthritis Research Society International and Mankin scores in bGH mice compared to WT control mice. Metabolomics analysis revealed changes in a wide range of metabolic pathways in bGH mice, including beta-alanine metabolism, tryptophan metabolism, lysine degradation, and ascorbate and aldarate metabolism. Also, bGH chondrocytes up-regulated fatty acid oxidation and increased expression of Col10a. Joints of GHa mice were remarkably protected from developing age-associated joint degeneration, with smooth articular joint surface. This study showed that an excessive amount of GH promotes joint degeneration in mice, which was associated with chondrocyte metabolic dysfunction and hypertrophic changes, whereas antagonizing GH action through a GHa protects mice from OA development.

FIBRONECTIN TYPE III DOMAIN CONTAINING 5 MITIGATES CHONDROCYTE SENESCENCE, SUBCHONDRAL OSTEOCLAST FORMATION, AND OSTEOARTHRITIS DEVELOPMENT THROUGH INHIBITING INTERLEUKIN-6

Senescent chondrocyte and subchondral osteoclast overburden aggravate inflammatory cytokine and pro-catabolic proteinase overproduction, accelerating extracellular matrix degradation and pain during osteoarthritis (OA). Fibronectin type III domain containing 5 (FNDC5) is found to promote tissue homeostasis and alleviate inflammation. This study aimed to characterize what role Fndc5 may play in chondrocyte aging and OA development.Serum and macroscopically healthy and osteoarthritic cartilage were biopsied from patients with knee OA who received total knee replacement. Murine chondrocytes were transfected with Fndc5 RNAi or cDNA. Mice overexpressing Fndc5 (Fndc5Tg) were operated to have destabilized medial meniscus mediated (DMM) joint injury as an experimental OA model. Cellular senescence was characterized using RT-PCR analysis of p16INK4A, p21CIP1, and p53 expression together with ß-galactosidase activity staining. Articular cartilage damage and synovitis were graded using OARSI scores. Osteophyte formation and mechanical allodynia were quantified using microCT imaging and von Frey filament, respectively. Osteoclast formation was examined using tartrate-resistant acid phosphatase staining.Senescent chondrocyte and subchondral osteoclast overburden together with decreased serum FNDC5 levels were present in human osteoarthritic cartilage. Fndc5 knockdown upregulated senescence program together with increased IL-6, MMP9 and Adamts5 expression, whereas Alcian blue-stained glycosaminoglycan production were inhibited. Forced Fndc5 expression repressed senescence, apoptosis and IL-6 expression, reversing proliferation and extracellular matrix production in inflamed chondrocytes. Fndc5Tg mice showed few OA signs, including articular cartilage erosion, synovitis, osteophyte formation, subchondral plate sclerosis and mechanical allodynia together with decreased IL-6 production and few senescent chondrocytes and subchondral osteoclast formation during DMM-induced joint injury. Mechanistically, Fndc5 reversed histone H3K27me3-mediated IL-6 transcription repression to reduce reactive oxygen species production.Fndc5 loss correlated with OA development. It was indispensable in chondrocyte growth and anabolism. This study sheds light onto the anti-ageing and anti-inflammatory actions of Fndc5 to chondrocytes; and highlights the chondroprotective function of Fndc5 to compromise OA.

The extinct osteoarthritic lagomorphs (Prolagus sardus) from Sardinia (Italy) reveal further evidence of life history evolution in insular domains

The study of past pathologies by means of quantitative reports is an underexplored approach to deal with the biology and ecology of extinct taxa. In the present study, we assessed the prevalence rate of primary osteoarthritis in a large sample of Prolagus sardus (Mammalia, Lagomorpha) from Medusa Cave (also known as Grotta Dragonara, Sardinia, Italy; Late Pleistocene) to shed light on the evolutionary history of small mammals under isolation regimes. The hip and knee joints of 246 femora were examined grossly, microscopically, and using advanced radiology, recording essential biological features such as age or weight. We noted that 27.7% of skeletally mature sample had degenerative disorder of the joints, with higher frequency in adults (p-value < 0.05), regardless of their body mass (p-value > 0.05). Histologically, affected joints displayed changes in subchondral plate potentially reflecting adaptive modeling. Our analysis revealed ageing (the extended lifespan) as the main driver of this prevalence rate, whereas mechanical factors (caused by a particular lifestyle) were considered of significantly lesser importance. Our results provide additional empirical support to the analytical framework of life history theory from a new perspective, according to which, under low extrinsic mortality regimes, selection should favor slow-strategies (extended lifespan) in small-sized mammals.

Preoperative planning to preserve glenoid subchondral bone in anatomical total shoulder replacement

Glenoid loosening remains a concern in anatomical total shoulder replacement. Preoperative planning software allows optimization of the component positioning, but the target orientation remains unclear due to conflicting optimization priorities. Commonly, the component is aligned to the prescribed version and inclination that reflect the population's average anatomy. The freehand technique attempts to secure strong fixation by aiming to preserve the subchondral bone. This study compared the state of the subchondral plate after reaming and compared the results of these two techniques. Two groups of shoulder computed tomography scans were assessed, 34 normal and 34 osteoarthritic. Preoperative planning software was used to place the glenoid component in prescribed adjusted angles, with neutral (0o,0o), retroverted (-10o,0o) and inclined alignment (0o,10o). The computed tomography Hounsfield values at the virtually reamed surface were assessed to determine the percentage of the intended component-bone interface consisting of cortical bone, here termed "cortical bone seating". This was then compared to positioning the component using a freehand technique. The freehand technique improved cortical bone seating in the osteoarthritic group with a mean (standard deviation) of 53.3% (14.3), while neutral alignment resulted in 36.7% (10.8), retroversion 40.4% (13.1), and inclination 39.3% (13.5), P<.001. A similar trend was observed in the normal group. The freehand method resulted in significantly improved cortical bone seating compared to the prescribed adjusted angles. These findings question the use of a one-size-fits-all-orientation and suggest that applying a technique that aims for maximum cortical fixation (freehand) may reduce the risk of aseptic loosening.

Retrograde "Sandwich" Technique and Implantation of Minced Cartilage in a Hyaluronic Acid Scaffold for Deep Osteochondral Knee Lesions

The management of deep osteochondral lesions is a subject of great controversy. Despite multiple studies and research efforts, it has not been possible to establish an ideal technique for their treatment. The main goal of all available treatments is to avoid the progress toward early osteoarthritis. Hence, this article will present a one-step technique for the handling of osteochondral lesions with a depth equal to or greater than 5 mm, with retrograde subchondral bone grafting to reconstruct the subchondral bone, seeking the greatest possible preservation of the subchondral plate, and implantation of autologous minced cartilage plus a hyaluronic acid–based scaffold (HyaloFast; Anika Therapeutics) under arthroscopic surgery.

Early zoledronate treatment inhibits subchondral bone microstructural changes in skeletally-mature, ACL-transected canine knees.

Anterior cruciate ligament (ACL) tear leads to post-traumatic osteoarthritis (PTOA), a significant clinical burden worldwide that currently has no cure. Recent studies suggest a role of subchondral bone adaptations in the development of PTOA. Particularly, microstructural changes in the rod-and-plate microstructure of subchondral bone may precede and contribute to OA progression. In this study, we quantified microstructural changes in subchondral trabecular rods and plates after ACL-transection for the first time in the well-established preclinical canine model of PTOA and investigated the therapeutic potentials of a bisphosphonate (zoledronate) and NSAID treatment (meloxicam). Unilateral hindlimb ACL transection was performed on skeletally-mature (2-year-old, N = 20) and juvenile (10-month-old, N = 20) male beagles. Animals were assigned to 4 groups (N = 5): ACLT, un-operated control, ACLT with zoledronate, and ACLT with meloxicam treatment. Subchondral bone microstructure was evaluated by micro-computed tomography and cartilage integrity was evaluated histologically. We found that ACL-induced subchondral bone changes depended on skeletal maturity of animals. In mature animals, significant loss of trabecular plates that resulted in reduced PR ratio occurred at Month 1 and persisted until Month 8. Zoledronate treatment prevented trabecular plate loss while meloxicam treatment did not. Whether cartilage degeneration is also attenuated warrants further investigation. In juvenile animals that have not reached skeletal maturity, transient changes in trabecular plate and rod microstructure occurred at Month 3 but not Month 9. Neither zoledronate nor meloxicam treatment attenuated bone microstructural changes or cartilage damages. Findings from this study suggest that early inhibition of bone resorption by bisphosphonate after injury may be a promising therapeutic approach to prevent alterations in subchondral bone microstructure associated with PTOA. Our results further demonstrate that pathogenesis of PTOA may differ between adolescent and adult patients and therefore require distinct management strategies.

Autologous surface repair: autologous matrix-induced chondrogenesis and minced cartilage implantation

<h2>ABSTRACT</h2><h3>Introduction</h3> The treatment of cartilage damage remains challenging. There are several procedures described. Microfracturing is considered one of the most established procedures, but long-term results are unsatisfactory, especially for larger defects. Autologous Matrix-Induced Chondrogenesis (AMIC), in which bone marrow-stimulated areas are covered with a membrane, has been introduced to address some of the limitations of microfracture with a number of long-term outcomes studies reporting satisfactory results. Minced cartilage Implantation (MCI), in which cartilage tissue is minced and inserted into cartilage defects has also been shown to have satisfactory results at 5-year results although longer-term results are still pending. <h3>Technique</h3> Both procedures can be performed arthroscopically. In the AMIC procedure, bone at the base of the chondral lesion is debrided to the subchondral plate and a bone marrow stimulation or microfracture is performed. Arthroscopic fluid is drained and the area covered with a membrane and fixed using fibrin glue or stiches either arthroscopically or using a mini-open approach. In MCI, the defect is also first debrided. Cartilage tissue removed from the affected joint is then cut into small pieces. In the open procedure, this is done with a scalpel; in the arthroscopic procedure, it is done with a shaver. The tissue is then inserted into the defcet and fixed using an allogeneic or autologous fibrin glue. <h3>Discussion</h3> AMIC and the minced cartilage technique represent a relatively simple, safe and reproducible evolution of cartilage repair techniques. Long-term studies (up to 9 years) support the satisfactory outcomes of the AMIC procedure. Five-year results for MCI procedure, report a decrease in pain and improved function, but long-term results are awaited. Well designed level one studies are now required to evaluate these techniqeus in the longer term.

"Can You Feel It": An Early Experience with Simulated Vibration to Recreate Glenoid Reaming.

We validated a novel custom simulator constructed using a vibration transducer transmitting simulated reaming vibrations to a powered nonwearing reamer tip through a 3D-printed glenoid. Validation and system fidelity were evaluated by 9 fellowship-trained shoulder surgeon experts performing a series of simulated reamings. We then completed the validation process through a questionnaire focused on experts' experience with the simulator. Experts correctly identified 52% ± 8% of surface profiles and 69% ± 21% of cartilage layers. Experts identified the vibration interface between simulated cartilage and subchondral bone (77% ± 23% of the time), indicating high fidelity for the system. An interclass correlation coefficient for experts' reaming to the subchondral plate was 0.682 (confidence interval 0.262-0.908). On a general questionnaire, the perceived utility of the simulator as a teaching tool was highly ranked (4/5), and experts scored "ease of instrument manipulation" (4.19/5) and "realism of the simulator" (4.11/5) the highest. The mean global evaluation score was 6.8/10 (range 5-10). We examined a simulated glenoid reamer and feasibility of haptic vibrational feedback for training. Experts validated simulated vibration feedback for glenoid simulation reaming, and the results suggested that this may be a useful additional training adjuvant. Level II, prospective study.

Daphnoretin relieves IL-1β-mediated chondrocytes apoptosis via repressing endoplasmic reticulum stress and NLRP3 inflammasome

BackgroundOsteoarthritis (OA), mainly caused by severe joint degeneration, is often accompanied by joint pain and dysfunction syndrome. Inflammatory mediators and apoptosis play key roles in the evolution of OA. It is reported that daphnoretin has significant antiviral and anti-tumor values. The present study aims at investigating the role of daphnoretin in OA.MethodsThe OA mouse model was constructed by performing the destabilization of the medial meniscus through surgery, and the OA cell model was induced in ATDC5 chondrocytes with IL-1β (10 ng/mL) in vitro. Chondrocyte viability and apoptosis were measured by 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide (MTT), Caspase-3 activity, and flow cytometry. The levels of COX-2, iNOS, TNF-α, IL-6, Bax, Bcl2, cleaved-Caspase3, endoplasmic reticulum stress (ERS) proteins (GRP78, CHOP, ATF6, and Caspase-12), and NLRP3-ASC-Caspase1 inflammasome were determined by quantitative real-time PCR or western blot. The concentrations of TNF-α, IL-6, and PGE2 were tested by enzyme-linked immunosorbent assay. The content of nitrates was detected by the Griess method. In vivo, morphologic differences in knee joint sections and the thickness of the subchondral bone density plate in mice were observed by hematoxylin–eosin (H&E) staining and safranin O-fast green staining.ResultsDaphnoretin effectively choked IL-1β-induced chondrocyte apoptosis and facilitated cell viability. Daphnoretin dose-dependently abated ERS, inflammatory mediators, and the activation of NLRP3 inflammasomes in IL-1β-induced chondrocytes. What’s more, in vivo experiments confirmed that daphnoretin alleviated OA progression in a murine OA model by mitigating inflammation and ERS.ConclusionDaphnoretin alleviated IL-1β-induced chondrocyte apoptosis by hindering ERS and NLRP3 inflammasome.Graphical abstract

Maximum Plantarflexion Lateral Ankle Radiograph for Pre-Operative Planning for the Arthroscopic Treatment of Osteochondral Lesions of the Talus

Category: Arthroscopy; Ankle; Sports; Trauma Introduction/Purpose: Osteochondral Lesions of the Talus (OLT) are now a commonly encountered pathology resulting in ankle pain and disability. Because of growing interest and support for arthroscopic management, it has become increasingly important to develop pre-operative evaluation methods to determine which lesions are amenable to standard arthroscopic evaluation and treatment versus the use of alternative strategies including posterior ankle arthroscopy, open arthrotomy, or malleolar osteotomy. Recently a CT scan protocol has been developed with the maximum ankle plantarflexion to estimate which lesions are accessible by standard anterior ankle arthroscopy based on the location of the lesion relative to the anterior tibial plafond. We present a simplified alternative method using a clinic-based lateral ankle radiograph with maximal plantarflexion to attain similar information for surgical planning. Methods: A 25-year-old female presented to clinic approximately 3 years after an initial injury to the left ankle sustained while skiing, with prior conservative treatment. After examination and review of available imaging, discussion was held with the patient regarding continued conservative management of her left ankle OLT versus surgical intervention with ankle arthroscopy, OLT debridement, and microfracture due to the lesion size of less than 150 mm2 based on previously described treatment algorithms. To determine the best approach for ankle arthroscopy, anterior versus posterior, a left ankle non-weight-bearing maximal plantar flexion radiograph was performed in the clinic. This showed that with plantarflexion, the anterior margin of the medial based OLT was adjacent to the anterior lip of the tibial plafond. Based on the clinical experience of the treating surgeon, this serves as an indication that the lesion can be adequately accessed using standard anterior ankle arthroscopy with plantarflexion and/or non- invasive distraction. Results: The patient underwent standard ankle anterior tibiotalar arthroscopy with non-invasive distraction. Following diagnostic arthroscopy and limited debridement, with the ankle manually plantarflexed by an assistant, the OLT leading edge was easily identified. The remaining joint was intact without cartilage injury. There was moderate synovitis noted anterior and medial. An arthroscopic shaver and curette was used to debride the unstable articular cartilage back to sharp, stable borders, and all loose cartilage fragments were removed from the joint. This left approximately 8 x 15 mm of exposed subchondral bone. The subchondral plate was intact without bone loss or evidence of collapse. Using an arthroscopic microfracture awl, several microfracture holes were created through the subchondral plate and into the underlying metaphyseal bone until marrow fat was identified. Postoperatively, she was non weight bearing for six weeks with range of motion as tolerated, and advanced to full activity at three months without residual symptoms. Conclusion: In the management of OLTs, the limits of anterior arthroscopy have been pushed with time, due to the added complexity and possible morbidity associated with posterior arthroscopy and medial malleolus osteotomies for an open approach. Many factors have an impact on the intraarticular access using anterior ankle arthroscopy, with the posterior talus being the most challenging site to access. As seen in this case presentation, this simple and cost-effective radiographic technique can be employed by the clinician, among other clinical and imaging tools, to help guide appropriate surgical technique for lesions in the posterior half of the talar body.