The use of radiofrequency energy for arthroscopic chondroplasty in the knee

The temperature profile in elbow arthroscopy using radiofrequency ablation

INTRODUCTION

Over the last decades, arthroscopic surgery has become increasingly relevant as its minimally invasive approach offers many benefits. To investigate the risks of orthoscopic surgery at the elbow, this study aimed to investigate the development of temperatures in elbow joints while performing radiofrequency ablation in arthroscopic surgery.

MATERIALS AND METHODS

We performed standard arthroscopic surgeries with posterolateral, transtricipital and anterolateral approaches on seven cadaveric elbows and performed ablation on predefined locations with or without irrigation. Two temperature probes were positioned into the olecranon fossa and between the ulnar nerve and the medial joint capsule. The temperature data were recorded using a real-time data logger. A bipolar radiofrequency ablation (bRFA) device was used at the medial and lateral recess and in the fossa olecrani over a defined period. Data was then analyzed using Matlab.

RESULTS

Using bRFA without irrigation results in rapidly increasing temperature within the joint. A significant temperature increase was found within only 5 s without irrigation (p = 0.0052) in the fossa olecrani. We did not observe critical temperatures above 41 °C close to the ulnar nerve within 30 s under constant irrigation (p = 0.0747).

CONCLUSIONS

Radiofrequency ablation (RFA) can be safely used in elbow arthroscopy with irrigation. The continuous use without irrigation should be limited to 3 s. Despite the anatomical proximity of the ulnar nerve and capsule, we were able to show that a possible rise in temperature most likely does not affect the ulnar nerve.

Radiofrequency in arthroscopic shoulder surgery: a systematic review

BACKGROUND

Radiofrequency has seen an increase in use in orthopedics including cartilage lesion debridement in the hip and knee as well as many applications in arthroscopic shoulder surgery. The purpose of this systematic review is to evaluate the safety and usage of radiofrequency in the shoulder.

METHODS

This systematic review was registered with PROSPERO (international registry) and followed the preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) guidelines. Embase and PubMed were searched using: "shoulder," "rotator cuff," "biceps," "acromion" AND "monopolar," "bipolar," "ablation," "coblation," and "radiofrequency ablation." The title and abstract review were performed independently. Any discrepancies were addressed through open discussion.

RESULTS

A total of 63 studies were included. Radiofrequency is currently utilized in impingement syndrome, fracture fixation, instability, nerve injury, adhesive capsulitis, postoperative stiffness, and rotator cuff disease. Adverse events, namely superficial burns, are limited to case reports and case series, with higher-level evidence demonstrating safe use when used below the temperature threshold. Bipolar radiofrequency may decrease operative time and decrease the cost per case.

CONCLUSIONS

Shoulder radiofrequency has a wide scope of application in various shoulder pathologies. Shoulder radiofrequency is safe; however, requires practitioners to be cognizant of the potential for thermal burn injuries. Bipolar radiofrequency may represent a more efficacious and economic treatment modality. Safety precautions have been executed by institutions to cut down patient complications from shoulder radiofrequency. Future research is required to determine what measures can be taken to further minimize the risk of thermal burns.

Time to reconsider post arthroscopic osteonecrosis of the knee: a systematic review

The etiology of post-arthroscopic osteonecrosis of the knee (PAONK) is still unknown. The aims of this systematic review were to analyze the main characteristics of patients who developed osteonecrosis after arthroscopy. We considered for inclusion in the review case reports, case series, retrospective and prospective clinical trial, that involved patients who developed osteonecrosis of the knee within 1 year of arthroscopy for meniscal lesion or anterior cruciate ligament rupture with or without chondropathy. In all cases, there was a pre-operative magnetic resonance imaging that excluded the presence of osteonecrosis. We used the MINORS criteria to estimate the risk of bias. A total of 13 studies that involved 125 patients were included in the review. Only 14 out of 55 patients performed the pre-operative MRI after the "window period", which we considered 6 weeks between the onset of symptoms and positive MRI findings. A diagnosis of PAONK was made for 55 patients within 1 year of surgery. Of these, 29% was treated conservatively, while 71% repeated surgery. Osteonecrosis after knee arthroscopy is a reality and surgeon shouldn't underestimate the persistence or re-emergence of symptoms after arthroscopy. It may be due to subchondral insufficiency fractures in osteopenic bone, without evidence of necrosis. However, there are not elements enough to differentiate clinical and radiological characteristics of PAONK from SPONK. Terminology should be simplified, distinguishing subchondral insufficiency fractures of the knee as a precursor of primary osteonecrosis of the knee.

Radiofrequency Chondroplasty of the Knee Yields Excellent Clinical Outcomes and Minimal Complications: A Systematic Review

Purpose

To evaluate reported clinical outcomes and complications following radiofrequency (RF) ablation for the treatment of knee chondral lesions.

Methods

A literature search was performed according to the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines by querying EMBASE, PubMed, and Scopus computerized databases from database inception through October 2022. Level I to IV clinical studies that reported outcomes or complications following RF-based chondroplasty were included. Postoperative outcome scores and complications were aggregated. Study quality was assessed via the Newcastle-Ottawa Scale.

Results

Ten articles from 2002 to 2018 consisting of 1,107 patients (n = 1,504 lesions) were identified. Four studies were of Level I evidence, 3 studies were Level II, 1 study was Level III, and 2 studies were Level IV. The mean patient age was 41.8 ± 6.3 years (range, 12-87). Seven studies (n = 1,037 patients) used bipolar RF devices, and 3 studies (n = 70 patients) used monopolar RF devices. The overall mean postoperative Lysholm, Tegner, and IKDC scores ranged from 83 to 91, 3.8 to 7, and 49 to 90, respectively, in lesions ranging from grade I-IV according to the Outerbridge Classification. Monopolar RF devices reported qualitatively similar mean changes in Lysholm scores (83), Tegner scores (3.8), and IKDC scores (range, 49-69) compared with bipolar RF devices (range, 86.4-91, 4.5-7, 90, respectively). The incidence of complications ranged from 0% to 4%. The most commonly reported complication was osteonecrosis (range, 0% to 4%). The incidence rate of patients undergoing additional surgery ranged from 0% to 4.5%.

Conclusions

The available literature on RF-based chondroplasty shows its efficacy and safety for the treatment of knee chondral lesions, with good clinical outcome scores and low complication and reoperation rates.

Level of Evidence

Level IV, systematic review of Level I-IV studies.

Radiofrequency-Based Chondroplasty Creates a Precise Area of Targeted Chondrocyte Death With Minimal Necrosis Outside the Target Zone: A Systematic Review

Purpose

To systematically examine the effects of radiofrequency (RF) ablation or coblation (controlled ablation) on chondrocyte viability following knee chondroplasty in preclinical literature to determine the effectiveness and safety of RF-based techniques.

Methods

A literature search was performed in September 2022 using PubMed and Scopus using the following search terms combined with Boolean operators: "chondroplasty," "radiofrequency," "thermal," "knee," "chondral defect," "articular cartilage," and "cartilage." The inclusion criteria consisted of preclinical studies examining the effect of RF ablation or coblation on chondrocytes during knee chondroplasty. Exclusion criteria consisted of studies reporting chondroplasty in joints other than the knee, clinical studies, in vitro studies using animal models, case reports, non-full-text articles, letters to editors, surveys, review articles, and abstracts. The following data were extracted from the included articles: author, year of publication, chondral defect location within the knee and chondral characteristics, RF probe characteristics, cartilage macroscopic description, microscopic chondrocyte description, and extracellular matrix characteristics.

Results

A total of 17 articles, consisting of 811 cartilage specimens, were identified. The mean specimen age was 63.4 ± 6.0 (range, 37-89) years. Five studies used monopolar RF devices, 7 studies used bipolar RF devices, whereas 4 studies used both monopolar and bipolar RF devices. Time until cell death during ablation at any power was reported in 5 studies (n = 351 specimens), with a mean time to cell death of 54.4 seconds (mean range, 23.1-64) for bipolar RF and 56.3 seconds (mean range, 12.5-64) for monopolar RF devices. Chondrocyte cell death increased with increased wattage, while treatment time was positively correlated with deeper cell death.

Conclusions

In this systematic review, histologic analysis demonstrated that RF-based chondroplasty creates a precise area of targeted chondrocyte death, with minimal evidence of necrosis outside the target zone. Caution must be exercised when performing RF-based chondroplasty due to the risk of cell death with increased application time and wattage.

Clinical Relevance

Although RF ablation has demonstrated favorable results in preliminary trials, including smoother cartilage and less damage to the surrounding healthy tissue, the risks versus benefits of the procedure are largely unknown. Caution must be exercised when performing RF-based chondroplasty in the clinical setting due to the risk of cell death with increased application time and wattage.

Mimicking osteochondral interface using pre-differentiated BMSCs/fibrous mesh complexes to promote tissue regeneration

The heterogeneous nature of osteochondral tissue requires the construction of implant with biomimetic gradients. Electrospun fibrous meshes with different designs provide the feasibility in arranging such a kind of gradient structure via layer-by-layer stacking. In this study, a kind of triphasic implant was constructed by layering pre-differentiated cell sheets, which were hold by electrospun poly(L-lactide)/gelatin (PLLA/Gel) fibrous meshes containing hyaluronic acid and chondroitin sulfate for the cartilage layer or hydroxyapatite for the bone layer. As for the calcified interlayer, the bone marrow mesenchymal stromal cells (BMSCs) seeded on PLLA/Gel fibrous mesh was pre-differentiated with a mixed osteoinductive/chondroinductive (1:1) medium. With this gradient construct being implanted in rabbit knee osteochondral defect, it was found that both the cartilage and subchondral bone were regenerated effectively with reproduced tidal line structure. The importance of implants with biomimetic gradients for osteochondral defect repair was confirmed, and cell sheets on electrospun fibrous meshes were flexible for gradient structure construction via the layer-by-layer stacking technology. HighlightsComposite fibrous meshes with tissue-specific components are electrospun.Confluent BMSCs on fibrous meshes are chondrogenically or osteogenically induced.BMSCs hypertrophy is induced with the mixture of chondroinductive and osteoinductive medium.The pre-differentiated cell/mesh complexes are stacked layer-by-layer to form gradient construct.The gradient construct efficiently promotes osteochondral regeneration in rabbit joint.

Improved Outcomes with Arthroscopic Bone Marrow Aspirate Concentrate and Cartilage-Derived Matrix Implantation versus Chondroplasty for the Treatment of Focal Chondral Defects of the Knee Joint: A Retrospective Case Series

Purpose

To compare the outcomes of patients undergoing treatment of focal chondral defects (FCDs) of the knee joint with chondroplasty versus bone marrow aspirate concentrate (BMAC) and cartilage-derived matrix (CDM) implantation.

Methods

A retrospective chart review was performed for patients diagnosed with Outerbridge grade 3-4 FCDs. Patients were included if they were treated arthroscopically with BMAC/CDM implantation or chondroplasty alone between March 2016 and May 2019 and had more than 1-year follow-up. Postoperative outcomes included the visual analog scale (VAS) for pain; University of California, Los Angeles (UCLA) activity scores; Knee Outcome Survey (KOS) Activities of Daily Living (ADL) and Sports subscores; postoperative corticosteroid or hyaluronic acid injections; subsequent surgeries; and conversion to total knee arthroplasty.

Results

A total of 98 patients were identified with a mean follow-up in BMAC/CDM of 24 months (range 13-41 months) and in chondroplasty of 44 months (range 34-55 months). A subanalysis was performed to control for significant differences in age, which yielded 39 patients, ages 40-60 years. Within the subanalysis group, mean VAS scores were significantly lower in the BMAC/CDM group (1.7 vs 4.4; P = .005) and mean UCLA scores were significantly greater (7.1 vs 5.0; P = .002). Mean improvement in VAS and UCLA scores were similar between the BMAC/CDM and chondroplasty groups (–3.7 vs –1.3; P = .71, 1.9 vs 0.1; P = .14, respectively). Mean KOS ADL and Sports subscores were significantly greater among patients in the BMAC/CDM group (87% vs 55%; P = .001, 71% vs 41%; P = .002, respectively). There were no differences in postoperative injections, subsequent surgeries, or conversion to total knee arthroplasty between the BMAC/CDM and chondroplasty groups.

Conclusions

Patients with grade 3-4 FCDs of the knee had improved postoperative outcomes when treated with BMAC/CDM implantation versus chondroplasty alone, as evidenced by a significant improvement in VAS and UCLA scores and significantly greater postoperative KOS ADL, and KOS Sport subscores.

Level of Evidence

IV, therapeutic case series.

Articular cartilage and osteochondral tissue engineering techniques: Recent advances and challenges

In spite of the considerable achievements in the field of regenerative medicine in the past several decades, osteochondral defect regeneration remains a challenging issue among diseases in the musculoskeletal system because of the spatial complexity of osteochondral units in composition, structure and functions. In order to repair the hierarchical tissue involving different layers of articular cartilage, cartilage-bone interface and subchondral bone, traditional clinical treatments including palliative and reparative methods have showed certain improvement in pain relief and defect filling. It is the development of tissue engineering that has provided more promising results in regenerating neo-tissues with comparable compositional, structural and functional characteristics to the native osteochondral tissues. Here in this review, some basic knowledge of the osteochondral units including the anatomical structure and composition, the defect classification and clinical treatments will be first introduced. Then we will highlight the recent progress in osteochondral tissue engineering from perspectives of scaffold design, cell encapsulation and signaling factor incorporation including bioreactor application. Clinical products for osteochondral defect repair will be analyzed and summarized later. Moreover, we will discuss the current obstacles and future directions to regenerate the damaged osteochondral tissues.

Use of a Novel Variable Power Radiofrequency Ablation System Specific for Knee Chondroplasty: Surgical Experience and Two-Year Patient Results

Introduction Although stabilisation of knee cartilage lesions (chondroplasty) may be performed with an arthroscopic shaver, more recently, radiofrequency (RF) ablation has gained in popularity. However, their remain some concerns about the avoidance of thermal injury, chondrolysis, and osteonecrosis with the use of RF devices. Methods We reviewed the outcomes of 85 knee chondroplasties performed with a new RF ablation wand designed for knee chondroplasty. Lesion details and Chondropaenia Severity Score (CSS) were recorded for each patient. We evaluated the occurrence of adverse outcomes, post-operative complications, and the need for further surgery. Post-operative outcomes scores (Oxford Knee Score [OKS], Knee injury and Osteoarthritis Outcome Score [KOOS], and International Knee Documentation Committee [IKDC] subjective knee outcome) were recorded at a minimum of one-year follow-up. Results At the final mean follow-up of 27.5 months (range: 12-46.6 months), 12 (14%) knees had undergone or were listed for further surgery. Four patients had corticosteroid injections for ongoing pain at a median 7.5 months (range: 5-20 months) post-operatively. There were no observed re-operations considered to be caused by complications related to thermal injury. Of the six patients listed for or undergoing knee arthroplasty, five (83%) had grade 4 lesions found at the arthroscopic chondroplasty. A negative correlation was noted between CCS, and post-operative IKDC subjective score (R=-0.35), KOOS Sports (R=-0.39), and KOOS QoL (R=-0.36). Conclusions We found that RF chondroplasty appeared safe, and there were no concerns with regard to thermal injury. Functional outcome appeared to be related to the quality of chondral and meniscal tissue throughout all knee compartments, with better results for isolated grade 2 and 3 cartilage lesions.

Arthroscopic debridement for focal articular cartilage lesions of the knee: A systematic review

BACKGROUND AND PURPOSE OF THE STUDY

Arthroscopic debridement, the most commonly applied surgical technique for focal cartilage lesions in the knee, is not included in most treatment algorithms because of discouraging results in the management of osteoarthritis of the knee. The present systematic review evaluates the outcome of arthroscopic cartilage debridement as the primary treatment of focal knee chondral lesions in adults, and defines its indications and role as the primary treatment of focal knee chondral lesions.

METHODS

Two independent investigators searched PubMed, Cochrane CENTRAL, and Virtual Health Library databases using the terms "knee", "cartilage", "chondral", "lesions", "injury", "damage", "debridement", "chondroplasty", "chondrectomy", alone and in combination. Clinical studies evaluating the effect of mechanical cartilage debridement in adults with symptomatic focal cartilage lesions in the knee joint regardless of the defect size and depth were included. We excluded studies if patients had a concomitant ligament or meniscus injury, and/or had additional debridement with monopolar radiofrequency energy.

MAIN FINDINGS

Available studies suggest good to excellent short and medium-term functional outcomes (KOOS, LKSS, Tegner scale) for focal cartilage lesions treated with debridement regardless of the defect size and depth. Data are lacking comparing cartilage debridement versus other cartilage repair techniques.

CONCLUSIONS

Arthroscopic debridement of focal articular cartilage lesions of the knee is associated with good to excellent short and medium-term postoperative outcomes, especially in terms of functional improvement. Arthroscopic debridement may be considered in the primary treatment of focal cartilage injuries regardless of the defect size and depth. However, available studies are limited and the level of evidence is low.

A tri-component knee plug for the 3rd generation of autologous chondrocyte implantation

Here, we report a newly designed knee plug to be used in the 3rd generation of Autologous Chondrocyte Implantation (ACI) in order to heal the damaged knee cartilage. It is composed of three components: The first component (Bone Portion) is a 3D printed hard scaffold with large pores (~ 850 µm), made by hydroxyapatite and β-tricalcium phosphate to accommodate the bony parts underneath the knee cartilage. It is a cylinder with a diameter of 20 mm and height of 7.5 mm, with a slight dome shape on top. The plug also comprises a Cartilage Portion (component 2) which is a 3D printed gelatin/elastin/sodium-hyaluronate soft thick porous membrane with large pores to accommodate chondrocytes. Cartilage Portion is secured on top of the Bone Portion using mechanical interlocking by designing specific knobs in the 3D printed construct of the Cartilage Portion. The third component of the plug (Film) is a stitchable permeable membrane consisting of polycaprolactone (PCL) on top of the Cartilage Portion to facilitate sliding of the knee joint and to hold the entire plug in place while allowing nutrients delivery to the Cartilage Portion. The PCL Film is prepared using a combination of film casting and sacrificial material leaching with a pore size of 10 µm. It is surface modified to have specific affinity with the Cartilage Portion. The detailed design criteria and production process of this plug is presented in this report. Full in vitro analyses have been performed, which indicate the compatibility of the different components of the plug relative to their expected functions.

Adjunct use of radiofrequency coblation for osteochondritis dissecans in children: A case report

RATIONALE

Osteochondritis dissecans (OCD) lesions involve disruption of the osteochondral unit along articular surfaces, with significant potential for joint deterioration if not managed appropriately.

PATIENT CONCERNS

A 15-year-old male presented with persistent and insidious right knee pain, which had worsened following a collision with another player during a basketball game, resulting in episodes of locking.

DIAGNOSES

Magnetic resonance imaging revealed a lateral trochlear OCD extending into the anterior lateral femoral condyle.

INTERVENTIONS

Chondral fraying was observed along the margins of the OCD. Retrograde drilling ensued with use of a 0.045-inch Kirschner wire throughout the lesion to a depth that would allow for penetration of healthy underlying subchondral bone to create an influx of healing factors. Three resorbable pegs were arthroscopically placed through an accessory portal overlying the lesion to stabilize the fracture and compress the gapped cartilage mantle to reduce flow of synovial fluid behind the lesion. Bipolar radiofrequency coblation was used to stabilize the chondral fraying and seal the gap along the periphery of the lesion.

OUTCOMES

The patient was put on a nonweight bearing protocol for 6 weeks, after which crutches and brace were discontinued, but therapy persisted. Repeat imaging at 3 months demonstrated excellent interval healing. The patient was released to slowly engage impact activities. Although he returned at approximately 8 months postoperatively with a contralateral anterior cruciate ligament tear, he reported the operative knee with the OCD was doing extremely well.

LESSONS

Radiofrequency coblation appears to be a viable strategy as an adjunct to management for OCD in children.

Radiofrequency Chondroplasty May Not Have A Long-Lasting Effect in the Treatment of Concomitant Grade II Patellar Cartilage Defects in Humans

The effect of radiofrequency chondroplasty on cartilage tissue is not well studied. This prospective pilot study investigates the effect of radiofrequency chondroplasty on International Cartilage Repair Society (ICRS) grade II patellar cartilage defects using high-resolution magnetic resonance imaging (MRI) with T2 mapping. Six consecutive patients were treated for ICRS grade II patellar cartilage defects using radiofrequency chondroplasty. Before surgery and at defined follow-ups (2 weeks, 4 and 12 months) a high-resolution morphological 3 Tesla MRI with quantitative T2 mapping was performed. At baseline MRI, global T2 values of cartilage defects were increased (46.8 ms ± 9.7) compared to healthy cartilage (35.2 ms ± 4.5) in the same knee which served as reference. Two weeks after treatment, global T2 values (39.2 ms ± 7.7) of the defect areas decreased. However, global T2 values of the defect areas increased beyond the preoperative levels at 4 months (47.4 ms ± 3.1) and 12 months (51.5 ms ± 5.9), respectively. Zonal T2 mapping revealed that the predominant changes in T2 values occurred at the superficial cartilage layer. T2 mapping appears to be an ideal method to monitor cartilage degeneration after chondroplasty. Based on the small sample size of this pilot study, radiofrequency chondroplasty may cause cartilage damage and may not have a long-lasting effect in the treatment of grade II patellar cartilage defects. In five out of six patients, postoperative cartilage damage was observed on quantitative MRI. This study was therefore terminated before completion. We recommend only addressing the pathology which indicated arthroscopy and leaving concomitant cartilage lesions untreated.

Quantitative Analysis of Surface Contouring with Pulsed Bipolar Radiofrequency on Thin Chondromalacic Cartilage

The purpose of this study was to evaluate the quality of surface contouring of chondromalacic cartilage by bipolar radio frequency energy using different treatment patterns in an animal model, as well as examining the impact of the treatment onto chondrocyte viability by two different methods. Our experiments were conducted on 36 fresh osteochondral sections from the tibia plateau of slaughtered 6-month-old pigs, where the thickness of the cartilage is similar to that of human wrist cartilage. An area of 1 cm² was first treated with emery paper to simulate the chondromalacic cartilage. Then, the treatment with RFE followed in 6 different patterns. The osteochondral sections were assessed for cellular viability (live/dead assay, caspase (cell apoptosis marker) staining, and quantitative analysed images obtained by fluorescent microscopy). For a quantitative characterization of none or treated cartilage surfaces, various roughness parameters were measured using confocal laser scanning microscopy (Olympus LEXT OLS 4000 3D). To describe the roughness, the Root-Mean-Square parameter (Sq) was calculated. A smoothing effect of the cartilage surface was detectable upon each pattern of RFE treatment. The Sq for native cartilage was Sq = 3.8 ± 1.1 μm. The best smoothing pattern was seen for two RFE passes and a 2-second pulsed mode (B2p2) with an Sq = 27.3 ± 4.9 μm. However, with increased smoothing, an augmentation in chondrocyte death up to 95% was detected. Using bipolar RFE treatment in arthroscopy for small joints like the wrist or MCP joints should be used with caution. In the case of chondroplasty, there is a high chance to destroy the joint cartilage.

Subchondral fracture caused by unevenly stiffened meniscus after radiofrequency-assisted arthroscopic knee meniscectomy: A case report and review of the literature

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Although the worsening of symptoms following knee arthroscopy in older patients is often labeled as progression of arthritic symptoms, subchondral insufficiency fracture following arthroscopy may be underdiagnosed.

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There is a possibility that uneven stiffening of the meniscus causes concentration of stress that resulted in postarthroscopic subchondral fracture.

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Surgeons should consider avoiding subsequent subchondral fracture when to use radiofrequency in the debridement of a torn meniscus.

Introduction

Causality for postarthroscopic osteonecrosis of the knee is unknown, and related mechanisms have been poorly characterized.

Presentation of case

This report describes a case of a 69-year-old man with subchondral fracture occurring after arthroscopic meniscectomy using a radiofrequency assisted shaver. The patient experienced increasingly intense knee pain 10 months after the meniscectomy. MR imaging revealed postarthroscopic osteonecrosis of the knee in the femoral medial condyle, requiring unicompartmental knee arthroplasty. A mid-coronal cut section of the resected medial femoral condyle showed a linear fracture line parallel to the subchondral bone endplate. Histopathological examination showed prominent callus formation on both sides of the fracture, comprised of reactive woven bone and granulation tissue. The middle portion of the resected medial meniscus was of uneven height, with significant stiffening of the higher side. The stiffened region of the medial meniscus corresponded to the subchondral fracture in the medial femoral condyle.

Discussion

The etiology of post-arthroscopic osteonecrosis of the knee is controversial, but it seems possible that altered knee biomechanics after meniscectomy may predispose patients to osteonecrosis. The findings of the current case suggested that uneven stiffening of the meniscus caused concentration of stress that resulted in postarthroscopic subchondral fracture.

Conclusion

Subchondral insufficiency fracture following arthroscopy may be underdiagnosed. Surgeons need to carefully consider the risk of subchondral fracture following uneven stiffening of the meniscus when to use radiofrequency in the debridement of a torn meniscus.

The history of radiofrequency energy and Coblation in arthroscopy: a current concepts review of its application in chondroplasty of the knee

Radiofrequency energy has had widespread use for a variety of surgical procedures. Its application in orthopedic surgery initiated with shoulder instability. Over the last couple decades it has been applied as surgical tool for cartilage treatment as well. There have been significant gains in its technology and our understanding of its potential benefits. We address its history and advancements in becoming a surgical tool for cartilage lesions along with a review of recent long-term follow up studies.

A Retrospective Study Assessing Safety and Efficacy of Bipolar Radiofrequency Ablation for Knee Chondral Lesions

OBJECTIVE

Bipolar radiofrequency (bRF) ablation is gaining popularity as a treatment modality for unstable knee chondral lesions of the knee. Limited reports of osteonecrosis and chondrolysis have been published; however, there is little data examining the safety of this treatment in larger series. This study aims to evaluate the safety and efficacy of bRF in the treatment of chondral lesions encountered during knee arthroscopy.

DESIGN

A retrospective evaluation of adverse outcomes in patients that underwent treatment of chondral lesions using bRF was undertaken. Secondary outcome measures included change in patient reported outcome scores and its correlation to patient demographics and quality of chondral and meniscal lesions using Chondropenia Severity Score.

RESULTS

Only 2.2% and 2.7% of the patients had a postoperative complication or required a reoperation, respectively. None of the complications were directly related to the use of bRF. A statistically significant difference was observed when comparing pre- and postoperative scores in all normalized categories ( P < 0.0001). No statistically significant correlation was found between change in self-reported scores and Chondropenia Severity Score.

CONCLUSION

Bipolar radiofrequency ablation is a safe modality in treatment of chondral lesions.

Patellofemoral Cartilage Repair

Purpose of Review

This review provides an overview of well-established and newly developed cartilage repair techniques for cartilage defects in the patellofemoral joint (PFJ). An algorithm will be presented for approaching cartilage defects considering the distinct anatomy of both the patellar and trochlear articular surfaces.

Recent Findings

Recent studies on cartilage repair in the PFJ have demonstrated improved outcomes in an attempt to delay or obviate the need for arthroplasty, and improve symptoms in young patients. While autologous chondrocyte implantation shows good and excellent outcomes for chondral lesions, osteochondral defects are adequately addressed with osteochondral allograft transplantation. In case of patellar malalignment, concomitant tibial tubercle osteotomy can significantly improve outcomes. Particulated cartilage and bone marrow aspirate concentrate are potential new alternative treatments for cartilage repair, currently in early clinical studies.

Summary

Due to the frequency of concomitant anatomic abnormalities in the PFJ, a thorough clinical examination combined with careful indication for each procedure in each individual patient combined with meticulous surgical technique is central to achieve satisfying outcomes. Additional comparative studies of cartilage repair procedures, as well as investigation of newer techniques, are needed.

Postarthroscopy Osteonecrosis of the Knee: Current Concepts

Knee osteonecrosis is a severe disease rapidly leading to end-stage osteoarthritis, which was classified into three categories: spontaneous, secondary, and postarthroscopy. To understand postarthroscopy osteonecrosis of the knee, all the three types of knee osteonecrosis have to be deepened. This article reviewed spontaneous and secondary osteonecroses of the knee, with special focus upon postarthroscopy osteonecrosis, which is a rare form, affecting patients operated for arthroscopic knee surgery, most commonly for meniscectomy. Due to its rarity, patients and surgeons are often unprepared for this complication. A correct diagnosis is essential for appropriate treatment, and also to determine if a preexisting osteonecrosis was present, avoiding medicolegal sequelae, although many authors agree that osteonecrosis (both spontaneous and postarthroscopy) represent unpreventable and unpredictable conditions. In spontaneous osteonecrosis, the treatment is defined according to the size and the degree of the lesion, whereas in postarthroscopy osteonecrosis, the size of the lesion has no prognostic value, and therefore, the choice of the correct treatment is based more on the timing of the diagnosis. A diagnostic and therapeutic algorithm was outlined on the basis of the actual knowledge.

Arthroscopic Chondral Debridement Using Radiofrequency Ablation for Patellofemoral Compartment Pathology

The purpose of this Technical Note is to introduce a surgical technique using a fluid pressure pump, mid-lateral portal, and radiofrequency ablation for visualization, assessment, and subsequent, accurate/adequate removal of patellofemoral articular lesions for the treatment of patellofemoral compartment pathology. With the patient in the supine position, and an inflated thigh tourniquet, standard lateral and medial portals are made. The medial-femoral compartment, notch, lateral-femoral compartment, and patellofemoral compartments are assessed. If pathology is seen within the patellofemoral compartment, a mid-lateral portal is made if chondral pathology cannot be addressed thoroughly. Addressing chondral pathology to achieve chondral stability is then performed using a combination of the radiofrequency ablator and chondrotome. This technique provides greater visibility and access to accurately and thoroughly smooth chondral pathology.

Debridement of Articular Cartilage: The Natural Course

Chondral defects of the knee are quite common, affecting an estimated 10% to 12% of the population. Symptomatic chondral defects are thought to be persistent and possibly progressive. Less is known about the natural history of asymptomatic chondral lesions. Traditional treatment of chondral lesions has involved arthroscopic debridement with a mechanical shaver. Radiofrequency chondroplasty has been explored as a possible alternative or adjuvant to mechanical chondroplasty. The role of chondroplasty in the setting of knee osteoarthritis is more controversial. Early studies demonstrated promising results of arthroscopic debridement in the context of knee arthritis. However, publications in the last 10 to 15 years have brought into question the role of arthroscopic debridement in the setting of knee osteoarthritis. The purpose of this chapter is to explore the role of arthroscopic debridement in the treatment of chondral defects.

Management of Patellofemoral Arthritis: From Cartilage Restoration to Arthroplasty

The management of patellofemoral cartilage lesions is controversial and should begin with a comprehensive nonsurgical treatment plan. Patients with patellofemoral cartilage lesions in whom nonsurgical treatment fails may be candidates for surgical treatment. Surgical treatment strategies for the management of patellofemoral cartilage lesions are guided by the size, quality, and location of the defect. Recent advancements in cartilage restoration and arthroplasty techniques as well as appropriate patient selection and meticulous surgical technique have resulted in promising outcomes in patients with patellofemoral cartilage lesions who undergo surgical treatment.

Does radiofrequency ablation (RFA) epiphysiodesis affect adjacent joint cartilage?

PURPOSE

To test the hypothesis that epiphysiodesis made with radiofrequency ablation (RFA) is a safe procedure that disrupts the growth plate without damaging the adjacent joint articular cartilage.

METHODS

RFA epiphysiodesis was done during 8 min in vivo in 40 growing pig tibia physis. In addition, three tibiae were ablated for 16 min and three more for 24 min. As a burned cartilage reference, six tibiae were ablated on the joint articular cartilage for 8 min. After the procedure, the animals were terminated and the tibiae were harvested. Magnetic resonance imaging (MRI) was done ex vivo to evaluate the joint articular cartilage in all samples. We used T1-weighted, T2-weighted, and water content sequences under a 1.5 T magnetic field.

RESULTS

On the burned articular cartilage, intensity changes were observed at MRI. We found no evidence of articular cartilage damage on the 40 8-min RFA procedures. The tibiae ablated for 16 min and 24 min showed intact joint cartilage.

CONCLUSIONS

Epiphysiodesis using RFA is safe for the adjacent articular cartilage. This study shows that RFA can be done safely in the growing physis of pigs, even with triple duration procedures.

What are the current indications for use of radiofrequency devices in hip arthroscopy? A systematic review

The role of radiofrequency energy (RFE) devices has been minimally studied in hip arthroscopy. The purpose of this study was to determine the role of RFE devices in hip arthroscopy through a systematic review of the literature. We searched the PubMed database using the following Medical Subject Heading terms: hip arthroscopy, hip radiofrequency, thermal capsulorrhaphy, thermal chondroplasty and radiofrequency debridement. Two authors independently reviewed the literature and included articles based on predetermined inclusion criteria. We excluded review, technique and experimental articles. After title and abstract review, we selected 293 articles for full-text review. Ten articles met the inclusion and exclusion criteria. For the included articles, a total of 305 hips underwent arthroscopy with concomitant RFE treatment at a mean age of 25.7 years. Eight articles presented patient-reported outcome (PRO) instruments, one study did not report an outcome instrument but utilized an evaluation of postoperative range of motion (ROM) and 1 year magnetic resonance image (MRI) and computed tomography (CT) imaging. The remaining article measured only the ROM pre- and postoperatively. Only one of the articles reviewed reported complications. Current evidence on the safety and indications for use of RFE devices in hip arthroscopy is insufficient. The literature shows mixed results regarding its use in hip arthroscopy. Although the use of thermal energy is not without risk, if used judiciously and appropriate precautions are taken to avoid damage to adjacent tissues, those devices can be useful for the treatment of certain intra-articular hip pathologies arthroscopically.

RFE based chondroplasty in wrist arthroscopy indicates high risk for chrondocytes especially for the bipolar application

Background

The application of radiofrequency energy (RFE) has become widespread for surgical performed chondroplasty especially due to the anticipated sealing effect, however the safety of this procedure in the wrist remains unclear. The purpose of this study was to investigate the subchondral temperature during radiofrequency energy (RFE) application simulating chondroplasty in an arthroscopic setting of the wrist.

Methods

A chondroplasty of the lunate fossa was performed during an arthroscopy setting on 14 cadaver arms using monopolar or biopolar RFE. The temperature was recorded simultaneously from 7 predefined anatomical landmarks.

Results

The mean temperature for both application modes did not exceed more than 30°C at all measured points, except for the lunate fossa. The highest subchondral measured peak temperature was 49.35°C (monopolar) and 69.21°C (bipolar) in the lunate fossa. In addition, the temperature decreased for both radiofrequency (RF) devices depending on the distance of the sensors to the RF-probe.

Conclusion

It remains to be questionable how safe RFE can be used for chondroplasty in wrist arthroscopy under continuous irrigation and constant movement to obtain the desired sealing effect. However, the bipolar device should be applied with more caution since peak temperature in the lunate fossa almost reached 70°C even under continuous irrigation.

Postarthroscopy osteonecrosis of the knee

PURPOSE

Spontaneous subchondral osteonecrosis of the knee joint confined to a localized area of one condyle can occur after arthroscopic procedures. Meniscal tears, arthroscopic meniscectomy, and radiofrequency chondroplasty are aetiological factors in the development of osteonecrosis. The aim of this study was to investigate whether the incidence of osteonecrosis increased when mechanical or radiofrequency chondroplasty was used in conjunction with arthroscopic meniscectomy.

METHODS

In this prospective clinical trial, arthroscopic meniscectomy was the primary treatment in 75 patients (mean age 40 ± 13) with stage II and III degenerative changes on the articular cartilage. Patients had to meet the following criteria: 1) have preoperative MRI and plain film radiographs showing no evidence of osteonecrosis; 2) be symptomatic for at least 6 weeks before the preoperative MRI; and 3) have arthroscopically confirmed stage II or III chondral lesion. A preoperative MRI was performed for all patients. For treatment of chondral lesions, debridement with a shaver or chondroplasty with a monopolar RF energy system was used. Patients were divided into three treatment groups. Partial meniscectomy of the medial or lateral (or both) menisci was performed on all patients, but patients in group 2 additionally received mechanical debridement of the chondral lesion, and those in group 3 were additionally treated with RF chondroplasty. Patients in group 1 were treated with partial meniscectomy alone. Patients were re-examined after 6 months, at which time a repeat MRI was performed.

RESULTS

Development of osteonecrosis was detected during the postoperative MRIs of five patients: two in group 1, two in group 2, and one in group 3.

CONCLUSION

The addition of mechanical or RF chondroplasty to meniscectomy did not increase the number of patients with osteonecrosis. Also, RF chondroplasty, which is commonly proposed to be an aetiological factor, resulted in a decrease in the number of patients that developed osteonecrosis.

LEVEL OF EVIDENCE

II.

Arthroscopic debridement of unicompartmental arthritis: fact or fiction?

Patients with recurrent or mechanical symptoms of unicompartmental knee arthritis that have failed conservative management are candidates for surgical intervention. Surgical options include debridement, lavage, chondroplasty, bone marrow-stimulating techniques, chondrocyte transfer, and chondrocyte implantation. These techniques have been well studied but it is still unclear which technique is superior. Various factors need to be accounted for when choosing the proper technique; among the factors discussed are the patient's age and the size of the articular cartilage defect.

A review of current concepts in radiofrequency chondroplasty

Radiofrequency (RF) chondroplasty is a promising treatment of chondral defects. The purpose of this study is to summarize current literature reporting the use of radiofrequency energy as an alternative treatment to mechanical shaving in chondroplasty. This review depicts the basic understanding of RF energy in ablating cartilage while exploring the basic science, laboratory evidence and clinical effectiveness of this form of chondroplasty. Laboratory studies have indicated that RF energy decreases inflammatory markers in the cartilage as well as providing optimal results with smoothing of chondral clefts. There have been concerns of chondrolysis due to heat damage of chondrocytes; however, this is unsubstantiated in clinical studies. These clinical trials have highlighted that RF energy is a safe and efficacious method of chondroplasty when compared to the mechanical shaving technique.

Temperature profile of radiofrequency probe application in wrist arthroscopy: monopolar versus bipolar

PURPOSE

The purpose of this study was to investigate the changes in temperature during wrist arthroscopy comparing monopolar and bipolar radiofrequency energy (RFE).

METHODS

A standard wrist arthroscopy was performed on 14 arms of 7 cadavers without irrigation or with continuous irrigation with 0.9% saline solution and gravity-assisted outflow through an 18-gauge needle. We treated 7 wrists with a bipolar device (VAPR II with 2.3-mm side effect electrodes; DePuy Mitek, Westwood, MA) and 7 wrists with a monopolar device (OPES Ablator for small joints, 45°; Arthrex, Naples, FL). The temperature was recorded simultaneously from 7 predefined anatomic landmarks.

RESULTS

We observed an increase in the temperature corresponding to the time of energy application. The highest measured peak temperatures were 52°C (monopolar) and 49.5°C (bipolar) without irrigation. Continuous irrigation led to a significant reduction in the temperature at the site of the energy application. The mean temperature decreased by 7°C for the monopolar system and 5°C for the bipolar system when irrigation was used. For both radiofrequency devices, we found a decrease in the temperature proportional to the distance of the sensors to the radiofrequency probe.

CONCLUSIONS

Monopolar and bipolar RFE can be safely used in wrist arthroscopy if a continuous irrigation system is applied and the energy impulse does not exceed 5 to 10 seconds. However, it should be used with great care to avoid local heat damage especially at the cartilage.

CLINICAL RELEVANCE

This basic science study was performed to gain data concerning the temperature in wrist arthroscopy and to broaden the knowledge about the risks when using RFE. Furthermore, we sought to control side effects of RFE by finding the best applied form of RFE regarding duration and pulsation (monopolar/bipolar).

Bipolar radiofrequency plasma ablation induces proliferation and alters cytokine expression in human articular cartilage chondrocytes

PURPOSE

The aim of the study was to determine the in vitro effects of plasma-mediated bipolar radiofrequency ablation on human chondrocyte compensatory proliferation and inflammatory mediator expression.

METHODS

Human articular cartilage biopsy specimens, from total knee replacement, and human chondrocytes in alginate culture, from patients undergoing autologous chondrocyte implantation, were exposed to plasma ablation with a Paragon T2 probe (ArthroCare, Austin, TX). Instantaneous chondrocyte death was investigated with live/dead assays of biopsy specimens and cell cultures. Chondrocyte proliferation was determined by Hoechst staining of DNA on days 3 and 6. Messenger RNA expression of IL-1β, IL-6, IL-8, tumor necrosis factor α, high-mobility group protein B1, matrix metalloproteinase 13, type IIA collagen, and versican was determined on days 3 and 6.

RESULTS

Live/dead imaging showed a well-defined local margin of cell death ranging from 150 to 200 μm deep, both in the alginate gel and in the biopsy specimens exposed to plasma ablation. The ablation-exposed group showed a significant proliferation increase compared with control on day 3 (P < .043). There were significant increases compared with control in IL-6 expression on day 3 (P < .020) and day 6 (P < .045) and in IL-8 expression on day 3 (P < .048). No differences were seen for IL-1β, tumor necrosis factor α, high-mobility group protein B1, matrix metalloproteinase 13, type II collagen, or versican.

CONCLUSIONS

This study has shown that exposure to plasma-mediated ablation induces a well-defined area of immediate cell death and a short-term increase in proliferation with human articular chondrocytes in vitro. The exposure also alters cytokine expression for the same period, causing upregulation of IL-6 and IL-8.

CLINICAL RELEVANCE

The results show the potential of plasma-mediated ablation to cause the onset of a tissue regeneration response with human articular cartilage.