Viability and Regeneration of Chondrocytes after Laser Cartilage Reshaping Using 1,460 nm Diode Laser

Thermal Damage in Orthopaedics

There are numerous potential sources of thermal damage encountered in orthopaedic surgery. An understanding of the preclinical mechanisms of thermal damage in tissues is necessary to minimize iatrogenic injuries and use these mechanisms therapeutically. Heat generation is a phenomenon that can be used to a surgeon's benefit, most commonly for hemostasis and local control of tumors. It is simultaneously one of the most dangerous by-products of orthopaedic techniques as a result of burring, drilling, cementation, and electrocautery and can severely damage tissues if used improperly. Similarly, cooling can be used to a surgeon's advantage in some orthopaedic subspecialties, but the potential for harm to tissues is also great. Understanding the potential of a given technique to rapidly alter local temperature-and the range of temperatures tolerated by a given tissue-is imperative to harness the power of heat and cold. In all subspecialties of orthopaedic surgery, thermal damage is a relevant topic that represents a direct connection between preclinical and clinical practice.

Temperature Profile Measurement From Radiofrequency Nasal Airway Reshaping Device

OBJECTIVE

Nasal airway obstruction (NAO) is caused by various disorders including nasal valve collapse (NVC). A bipolar radiofrequency (RF) device (VivAer®, Aerin Medical, Sunnyvale, CA) has been used to treat NAO through RF heat generation to the upper lateral cartilage (ULC). The purpose of this study is to measure temperature elevations in nasal tissue, using infrared (IR) radiometry to map the spatial and temporal evolution of temperature.

STUDY DESIGN

Experimental and computational.

METHODS

Composite porcine nasal septum was harvested and sectioned (1 mm and 2 mm). The device was used to heat the cartilage in composite porcine septum. An IR camera (FLIR® ExaminIR, Teledyne, Wilsonville, OR) was used to image temperature on the back surface of the specimen. These data were incorporated into a heat transfer finite element model that also calculated tissue damage using Arrhenius rate process.

RESULTS

IR temperature imaging showed peak back surface temperatures of 49.57°C and 42.21°C in 1 and 2 mm thick septums respectively. Temperature maps were generated demonstrating the temporal and spatial evolution of temperature. A finite element model generated temperature profiles with respect to time and depth. Rate process models using Arrhenius coefficients showed 30% chondrocyte death at 1 mm depth after 18 s of RF treatment.

CONCLUSION

The use of this device creates a thermal profile that may result in thermal injury to cartilage. Computational modeling suggests chondrocyte death extending as deep as 1.4 mm below the treatment surface. Further studies should be performed to improve dosimetry and optimize the heating process to reduce potential injury. Laryngoscope, 134:1063-1070, 2024.

The synergic use of the High Power Laser Therapy and Glucosamine sulfate in Knee osteoarthritis: A Randomized Controlled Trial

Background and aim:

To determine the efficacy of the synergistic use of High Power Laser Therapy (HPLT) with glucosamine sulfate (GS) in knee osteoarthritis.

Methods:

This 2-arm randomized controlled trial (RCT) enrolled 90 subjects (M=53, F=37, y= 55±11.2) and randomly allocated using a stratified sampling method in experimental group (A) with HPLT+GS 1500mg (GS - Dona®, Rottapharm, Monza, Italy) (n=45) or in a control group (B) with HPLT + placebo (n=45).

Results:

VAS score in Activities of day Living (ADL), Standardized stair climb test (SSCT), Zohlen’s sign (RASPING) and Rabot test were used, to evaluate patients at the beginning of the study (T0), at 2 months (T1) and at 6 months (T2). In the mean scores for VAS in ADL, SSCT, RABOT and RASPING at T1, no significant differences were found between the experimental and the control group with paired T and ANOVA test. But significant differences between groups (p<0.05) in all outcomes were observed at 6 months (T2).

Conclusions:

HPLT is useful in treating knee osteoarthritis, but when combined with Glucosamine Sulfate, thanks to the synergy of two interventions, can achieve a long-term effect up to 6 months after treatment. (www.actabiomedica.it)

Rheometer enabled study of cartilage frequency-dependent properties

Despite the well-established dependence of cartilage mechanical properties on the frequency of the applied load, most research in the field is carried out in either load-free or constant load conditions because of the complexity of the equipment required for the determination of time-dependent properties. These simpler analyses provide a limited representation of cartilage properties thus greatly reducing the impact of the information gathered hindering the understanding of the mechanisms involved in this tissue replacement, development and pathology. More complex techniques could represent better investigative methods, but their uptake in cartilage research is limited by the highly specialised training required and cost of the equipment. There is, therefore, a clear need for alternative experimental approaches to cartilage testing to be deployed in research and clinical settings using more user-friendly and financial accessible devices. Frequency dependent material properties can be determined through rheometry that is an easy to use requiring a relatively inexpensive device; we present how a commercial rheometer can be adapted to determine the viscoelastic properties of articular cartilage. Frequency-sweep tests were run at various applied normal loads on immature, mature and trypsinased (as model of osteoarthritis) cartilage samples to determine the dynamic shear moduli (G*, G′ G″) of the tissues. Moduli increased with increasing frequency and applied load; mature cartilage had generally the highest moduli and GAG depleted samples the lowest. Hydraulic permeability (K_H) was estimated from the rheological data and decreased with applied load; GAG depleted cartilage exhibited higher hydraulic permeability than either immature or mature tissues. The rheometer-based methodology developed was validated by the close comparison of the rheometer-obtained cartilage characteristics (G*, G′, G″, K_H) with results obtained with more complex testing techniques available in literature. Rheometry is relatively simpler and does not require highly capital intensive machinery and staff training is more accessible; thus the use of a rheometer would represent a cost-effective approach for the determination of frequency-dependent properties of cartilage for more comprehensive and impactful results for both healthcare professional and R&D.

Characterization of Injury Induced by Routine Surgical Manipulations of Nasal Septal Cartilage

Importance

This study characterizes and compares common surgical manipulations' effects on septal cartilage to understand their implications for rhinoplasty outcomes based on cell viability and cartilage health.

Objective

To illustrate distinct differences in the impact of various surgical manipulations on septal cartilage in an in vitro septal cartilage model. A secondary objective is to better understand the chondrocyte's response to injury as well as how alterations in the extracellular matrix correspond to chondrocyte viability.

Design, Setting, and Participants

In this bench-top in vitro porcine model using juvenile bovine septal cartilage from bovine snouts, easily obtainable septal cartilage was used to generate large numbers of homogenous cartilage specimens. Quantitative outcomes at early and late time points were cell viability, cell stress, matrix loss, and qualitative assessment through histologic examination. The study was performed at a single academic tertiary care research hospital.

Interventions

Four common surgical manipulations were contrasted with a control group: crushed cartilage, scored cartilage, diced cartilage, and shaved cartilage.

Main Outcomes and Measures

Following the manipulation of the cartilage, the quantitative outcomes were glycosaminoglycan release to the media, lactate dehydrogenase release to the media, and cell death analysis through apoptosis staining. The qualitative outcomes were histologic staining of the manipulated cartilage with safranin-O/fast green stain to identify proteoglycan loss.

Results

The crushing followed by shaving manipulations were the most damaging as indicated by increased levels of lactate dehydrogenase release, glycosaminoglycans loss, and cell death. Matrix loss did not increase until after 48 hours postinjury. Furthermore, chondrocyte death was seen early after injury and accelerated to the late time point, day 9, in all manipulations. Conversely, cell stress was found to be greater at 48 hours postinjury, which then declined to the late time point, day 9.

Conclusions and Relevance

The crushing manipulation followed by shaving and then dicing were the most destructive methods of cartilage manipulation relative to control specimens. Collectively, these outcomes demonstrate the range of injury which occurs with all septal cartilage manipulations and can inform rhinoplasty practice to use the least damaging effective surgical manipulation to obtain the desired outcome.

Level of Evidence

NA.

Laser photobiomodulation for cartilage defect in animal models of knee osteoarthritis: a systematic review and meta-analysis

To review and assess the efficacy of laser photobiomodulation for cartilage defect in animal models of knee osteoarthritis (KOA). Medline, Web of Science, and EMBASE were searched. Studies were considered if the global quality score of cartilage were parallelly reported between laser and untreated control groups. The methodological quality of each study was assessed using a modified 10-item checklist. The effect size was estimated by standardized mean difference (SMD) and pooled based on the random-effects model. Stratified analysis and regression analysis were conducted to partition potential heterogeneity. An adjusted significant level of 0.01 was acceptable. Five hundred eight initial search recordings were identified, of which 14 studies (including 274 animals) were included for quantitative analysis. The global quality scores mostly weighted by the structural integrity and chondrocyte distribution were measured by different four scales including Histologic Histochemical Grading System (HHGS), Osteoarthritis Research Society International (OARSI), Pineda, and Huang. There were considerable variances on laser parameters and irradiation time among those included studies. Overall, a moderate level of methodological qualities was determined. The synthesis results indicated that the SMD effect size was significantly larger in HHGS (z = 2.61, P = 0.01) and Huang (z = 4.90, P < 0.01) groups. Stratified by irradiance, SMD of low (< 1 W/cm²) but not high (≥ 1 W/cm²) level estimated significant difference (z = 5.62, P < 0.01). Meta-regression identified a significant association for SMDs and irradiation time (P < 0.01). Yet, Egger's test detected small study effect (P < 0.01). No individual study with significant variance was found in homogeneity tests. The results demonstrated the positive effect of laser photobiomodulation for cartilage defect in animal models of KOA under proper irradiance and adequate irradiation time.

Effects of Intradiscal Injection of Local Anesthetics on Intervertebral Disc Degeneration in Rabbit Degenerated Intervertebral Disc

Analgesic discoblock is widely used for the diagnosis or treatment of discogenic low back pain by injecting local anesthetics. The purpose of this study was to investigate the deleterious effects of local anesthetics on degenerated rabbit intervertebral disks (IVDs) using an organotypic culture model and in vivo long-term follow-up model. To induce IVD degeneration, a rabbit annular puncture model was used. For the organotypic culture model, degenerated IVDs were harvested 1 month after the initial annular puncture and cultured for 3 or 7 days after intradiscal injection of local anesthetics (1% lidocaine and 0.5% bupivacaine). To perform in vivo analysis, local anesthetics were injected into degenerated IVDs, and IVDs were prepared for histological analysis after 6 or 12 months. In the organotypic model, terminal deoxynucleotidyl transferase dUTP nick end labeling-positive nucleus pulposus (NP) cells were significantly increased in the bupivacaine group compared with the other groups. In the in vivo study, the number of NP cells was significantly decreased in the saline and local anesthetics groups compared with the untreated control and puncture-only groups. However, there was no significant difference among the saline, lidocaine, and bupivacaine groups. In addition, histological analysis showed no significant difference of IVD degeneration among the puncture-only, saline, lidocaine, and bupivacaine groups. Although bupivacaine induced apoptotic NP cell death in the organotypic culture model, in vivo observations did not show any definitive proof to suggest that local anesthetics were capable of promoting degeneration in the degenerated IVD, except for pressurized injection-induced damage. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1963-1971, 2019.

[Preliminary study on microdissection needle-assisted ear cartilage reshaping in vivo rabbit models]

Objective

To preliminarily investigate morghological changes of rabbits reshaping ear cartilage assisted by microdissection needle and explore feasibility of new therapy for ear deformity.

Methods

The bilateral ears of 5 male New Zealand rabbits (aged, 5-6 months) were fixed maintaining the curvature and randomly divided into 2 groups (5 ears in each group). The ears were stimulated by microdissection needle in experimental group and were not treated with stimulation in control group. The skin reaction in the experimental group was observed immediately and at 4 weeks after stimulation. Then, the fixtures were removed at 4 weeks, and the shapes of the ears were observed. The cartilages were harvested from the ears to examined morphological changes after HE staining, and measured the chondrocyte layer thickness.

Results

All rabbits survived until the end of the experiment. The skin has healed completely after 4 weeks in experimental group. After removing fixtures, the ears in the two groups all maintained certain forms momentarily; while 24 hours later, the ears in the control group mostly recovered original form, and the ears in the experimental group still maintained certain molding form until 8 weeks. HE staining showed there were smooth cartilage and uniform distribution of cells in the control group; the matrix staining was basically consistent; and the skin was normal appearance with epidermis, dermis, and cartilage of normal aspect. But the proliferation of chondrocyte with more layers of cells were observed in the experimental group. In addition, there were degeneration and injury of cartilage cells and connective tissue with necrotic cells and inflammatory cells at needle insertion sites. The chondrocyte layer thickness was (385.714±2.027) μm in the control group and (1 594.732±1.872) μm in the experimental group, there was significant difference between the two groups ( t=-759.059, P=0.000).

Conclusion

Rabbit ear cartilage can be effectively reshaped by microdissection needle. Proliferation of chondrocyte and changes in matrix can be found during the reshaping process.

Laser Soldering of Cartilage Graft Interposed Into a Tracheal Incision in a Porcine Model

OBJECTIVES/HYPOTHESIS

Investigate the feasibility of soldering a free cartilage graft into a tracheal defect by laser heating and assessing the resulting burst pressure and thermal damage to the cartilage.

STUDY DESIGN

Animal study.

METHODS

A 20 × 8 mm defect was created in fresh cadaveric pig tracheas, a cartilage graft of the same size was harvested from the thyroid ala cartilage, and the graft was fitted into the defect. The soldering process involved covering the edges with liquid albumin and using a fiber-laser system for heating the edges to temperature T under temperature control. This was done for groups of grafts at various temperatures T = 60°C to 90°C. The tracheas were sealed, for each group the burst pressure was measured, and a histologic examination of the soldered incisions was performed.

RESULTS

The burst pressures were in the range of 66 to 409 mm Hg. The median burst pressure was 78, 157, 231, and 146 mm Hg, respectively, for T = 60°C, 70°C, 80°C, and 90°C. Statistical analysis revealed significant differences in burst pressures between the T = 60°C group and the T = 80°C and T = 90°C groups (P < .05). The highest burst pressure was measured in the T = 80°C group. Histologic examination revealed no thermal damage to the cartilage at this temperature.

CONCLUSIONS

Performing a sutureless laser soldering of a free cartilage graft to a tracheal defect, achieving an immediate watertight bond, is feasible. At T = 80°C the highest burst pressures were achieved. No histologic damage was observed. In vivo studies are needed before implementation of this technique in laryngotracheopasty.

LEVEL OF EVIDENCE

NA Laryngoscope, 129:58-62, 2019.

Assessing the negative impact of phenyl alkanoic acid derivative, a frequently prescribed drug for the suppression of pain and inflammation, on the differentiation and proliferation of chondrocytes

Background

Non-steroidal anti-inflammatory drugs (NSAIDs) are frequently prescribed to relieve pain and inflammation. These NSAIDs have also analgesic effects and can be administered via oral, injectable, and topical routes. During inflammation, a number of synovial mediators and cytokines are released which decrease the pH level of the synovial fluid. Administration of acidic NSAIDs further decreases the pH levels and hence contributes to the destruction of the cartilage. To our knowledge, no cellular-based study regarding the chondrotoxicity of phenyl alkanoic acid derivatives on NSAIDs was conducted before. Thus, the aim of this pioneering study was to examine the effect of frequently prescribed NSAIDs, a phenyl alkanoic acid derivative, flurbiprofen, on the proliferation and differentiation of human primer chondrocyte cultures in vitro.

Methods

Primer chondrocyte cultures were prepared from osteochondral tissue obtained during surgery for gonarthrosis. Samples not exposed to the pharmacological agent were used as the control group. The samples were treated with 1, 10, 100, 250, 500, or 1000 μM of the agent for 24, 48, and 72 h. The cell viability, toxicity, and proliferation were assessed with MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) analysis and prechondrocytic precursor stage-specific embryonic antigen-1 (SSEA-1) expression using a commercial ELISA kit spectrophotometrically. The surface morphology of the samples in each group was compared using an inverted light microscope and an environmental scanning electron microscope (ESEM). An analysis of variance was used to compare between-group differences. Tukey’s honest significant difference (HSD) method (95 % confidence interval) was used to evaluate the differences and significance in averages. The alpha significance value was considered <0.01.

Results

Statistically significant cytotoxicity was observed in the treatment groups. NSAID had a significant negative effect on the proliferation and differentiation of chondrocytes as compared to the control group (p < 0.01).

Conclusion

Before administering phenyl alkanoic acid derivatives in the clinical setting, their role in suppressing the proliferation and differentiation of chondrocytes should be taken into account. Thus, caution should be given when prescribing these drugs.

In vivo needle-based electromechanical reshaping of pinnae: New Zealand White rabbit model

IMPORTANCE

Electromechanical reshaping (EMR) is a low-cost, needle-based, and simple means to shape cartilage tissue without the use of scalpels, sutures, or heat that can potentially be used in an outpatient setting to perform otoplasty.

OBJECTIVES

To demonstrate that EMR can alter the shape of intact pinnae in an in vivo animal model and to show that the amount of shape change and the limited cell injury are proportional to the dosimetry.

DESIGN, SETTING, AND SPECIMENS

In an academic research setting, intact ears of 18 New Zealand white rabbits underwent EMR using 6 different dosimetry parameters (4 V for 5 minutes, 4 V for 4 minutes, 5 V for 3 minutes, 5 V for 4 minutes, 6 V for 2 minutes, and 6 V for 3 minutes). A custom acrylic jig with 2 rows of platinum needle electrodes was used to bend ears at the middle of the pinna and to perform EMR. Treatment was repeated twice per pinna, in proximal and distal locations. Control pinnae were not subjected to current application when being bent and perforated within the jig. Pinnae were splinted for 3 months along the region of the bend using soft silicon sheeting and a cotton bolster.

MAIN OUTCOMES AND MEASURES

The ears were harvested the day after splints were removed and before euthanasia. Photographs of ears were obtained, and bend angles were measured. Tissue was sectioned for histologic examination and confocal microscopy to assess changes to microscopic structure and cellular viability.

RESULTS

Treated pinnae were bent more and retained shape better than control pinnae. The mean (SD) bend angles in the 7 dosimetry groups were 55° (35°) for the control, 60° (15°) for 4 V for 4 minutes, 118° (15°) for 4 V for 5 minutes, 88° (26°) for 5 V for 3 minutes, 80° (17°) for 5 V for 4 minutes, 117° (21°) for 6 V for 2 minutes, and 125° (18°) for 6 V for 3 minutes. Shape change was proportional to electrical charge transfer, which increased with voltage and application time. Hematoxylin-eosin staining of the pinnae identified localized areas of cell injury and fibrosis in the cartilage and in the surrounding soft tissue where the needle electrodes were inserted. This circumferential zone of injury (range, 1.5-2.5 mm) corresponded to dead cells on cell viability assay, and the diameter of this region increased with total electrical charge transfer to a maximum of 2.5 mm at 6 V for 3 minutes.

CONCLUSIONS AND RELEVANCE

Electromechanical reshaping produced shape change in intact pinnae of rabbits in this expanded in vivo study. A short application of 4 to 6 V can achieve adequate reshaping of the pinnae. Tissue injury around the electrodes increases with the amount of total current transferred into the tissue and is modest in spatial distribution. This study is a critical step toward evaluation of EMR in clinical trials.

LEVEL OF EVIDENCE

NA.

Laser radiation effect on chondrocytes and intercellular matrix of costal and articular cartilage impregnated with magnetite nanoparticles

BACKGROUND AND OBJECTIVE

Magnetic nanoparticles with the ability to absorb laser radiation are the perspective agents for the early diagnostics and laser therapy of degenerative cartilage. The effect of starch stabilized magnetite nanoparticles (SSNPs) on the cartilage structure components has never been studied before. The aim of the work is to establish the Erbium:glass laser effect on costal and articular cartilage impregnated with SSNPs.

MATERIALS AND METHODS

Porcine articular and costal cartilage disks (2.0 mm in diameter and 1.5-2 mm in thickness) were impregnated with SSNPs and irradiated using a 1.56 μm laser in therapeutic laser setting. The one sample group underwent the second irradiation after the SSNPs impregnation. The samples were analyzed by the means of histology, histochemistry and transmission electron microscopy (TEM) to reveal the alterations of cells, glycosaminoglycans and collagen network.

RESULTS

The irradiated cartilage demonstrates the higher content of cell alterations than the intact one due to the heat and mechanical affection in the course of laser irradiation. However the alterations are localized at the areas near the irradiated surfaces and not dramatic. The impregnation of SSNPs does not cause any additional cell alterations. For both costal and articular cartilage the matrix alterations of irradiated samples are not critical: there is the slight decrease in acid proteoglycan content at the irradiated areas while the collagen network is not altered. Distribution and localization of impregnated SSNPs is described: agglomerates of 150-230 nm are observed located at the borders between matrix and cell lacunas of articular cartilage; SSNPs of 15-45 nm are found in the collagen network of costal cartilage.

CONCLUSIONS

It was shown that SSNPs do not appreciably affect the structural components of both articular and costal cartilage and can be safely used for the laser diagnostics and therapy. The area of structural alterations is diffuse and local as the result of the mechanical and heat effect of laser impact. SSNPs reveal the areas of the structural alterations of cartilage matrix and give information about the size of the pores and defects.

Effects of single injection of local anesthetic agents on intervertebral disc degeneration: ex vivo and long-term in vivo experimental study

BACKGROUND

Analgesic discography (discoblock) can be used to diagnose or treat discogenic low back pain by injecting a small amount of local anesthetics. However, recent in vitro studies have revealed cytotoxic effects of local anesthetics on intervertebral disc (IVD) cells. Here we aimed to investigate the deteriorative effects of lidocaine and bupivacaine on rabbit IVDs using an organotypic culture model and an in vivo long-term follow-up model.

METHODS

For the organotypic culture model, rabbit IVDs were harvested and cultured for 3 or 7 days after intradiscal injection of local anesthetics (1% lidocaine or 0.5% bupivacaine). Nucleus pulposus (NP) cell death was measured using confocal microscopy. Histological and TUNEL assays were performed. For in vivo study, each local anesthetic was injected into rabbit lumbar IVDs under a fluoroscope. Six or 12 months after the injection, each IVD was prepared for magnetic resonance imaging (MRI) and histological analysis.

RESULTS

In the organotypic culture model, both anesthetic agents induced time-dependent NP cell death; when compared with injected saline solution, significant effects were detected within 7 days. Compared with the saline group, TUNEL-positive NP cells were significantly increased in the bupivacaine group. In the in vivo study, MRI analysis did not show any significant difference. Histological analysis revealed that IVD degeneration occurred to a significantly level in the saline- and local anesthetics-injected groups compared with the untreated control or puncture-only groups. However, there was no significant difference between the saline and anesthetic agents groups.

CONCLUSIONS/SIGNIFICANCE

In the in vivo model using healthy IVDs, there was no strong evidence to suggest that discoblock with local anesthetics has the potential of inducing IVD degeneration other than the initial mechanical damage of the pressurized injection. Further studies should be performed to investigate the deteriorative effects of the local injection of analgesic agents on degenerated IVDs.