Effect of bipolar radiofrequency energy on human articular cartilage. Comparison of confocal laser microscopy and light microscopy

Does radiofrequency ablation reduce pain and improve maximal incisal opening more effectively than electrocautery in temporomandibular joint arthroscopy? A pilot study

OBJECTIVE

The study compared the effectiveness of radiofrequency and electrocautery techniques in TMJ arthroscopic surgeries by evaluating changes in pain levels and maximal incisal opening before surgery and throughout a 30-day postoperative period.

MATERIALS AND METHODS

This prospective, randomized controlled trial included 62 patients with bilateral TMJ disorders classified as Wilkes stages III and IV. Patients were randomly assigned to two groups: Group 1 (n = 31) underwent arthroscopy with electrocautery, and Group 2 (n = 31) received radiofrequency ablation. Inclusion criteria were patients with Wilkes stages III or IV TMJ disorders. Exclusion criteria included previous TMJ surgery, significant systemic disease, or contraindications to surgery. Pain levels were assessed using the McGill Pain Questionnaire, and maximal incisal opening was measured preoperatively and up to 30 days postoperatively.

RESULTS

The sample included 62 subjects with a mean age of 33.5 years, 80.6% female. The electrocautery group showed significantly greater maximal incisal opening at 12 h, 7 days, and 14 days post-surgery compared to the radiofrequency ablation group. Pain levels did not differ significantly between groups, though the electrocautery group reported higher pain scores on postoperative day 14. Both groups showed similar pain improvement and maximal incisal opening changes over 30 days, with a trend towards more improvement in maximal incisal opening in the radiofrequency ablation group. No significant differences in complications or overall pain improvement were observed.

CONCLUSION

Electrocautery and radiofrequency did not differ in postoperative pain outcomes; however, electrocautery was more effective in improving maximal incisal opening up to postoperative day 14.

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.

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.

Bipolar Radiofrequency Ablation Does Not Result in Full-Thickness Articular Cartilage Penetration: An Ex Vivo Bovine Investigation

Purpose

Methods

Results

Conclusions

Clinical Relevance

Glenohumeral Osteoarthritis: The Role for Orthobiologic Therapies: Platelet-Rich Plasma and Cell Therapies

The glenohumeral (GH) joint ranks third on the list of the large joints that are most commonly affected by osteoarthritis, after the knee and the hip. General nonsurgical modalities, including changes in daily activities, physical therapy, pharmacotherapy, and corticosteroid injections, constitute the mainstay of treatment. Most of these options, however, have shown moderate and short-term effectiveness. Arthroplasty techniques have proven to be successful for elderly patients. Nevertheless, replacement options are not optimal for younger patients because their functional demands are higher and prostheses have a finite life span. This has led to the search for new nonoperative treatment options to target this subgroup of patients. It has been suggested that orthobiologic therapies, including platelet-rich plasma (PRP) and cell therapies, present great promise and opportunity for the treatment of GH osteoarthritis. Despite the promising results that have been shown by cell therapies and PRP for treating degenerative joint conditions, additional studies are needed to provide more definitive conclusions.

The Efficacy and Safety of Subcutaneous Radiofrequency After Liposuction: A New Application for Face and Neck Skin Tightening

BACKGROUND

Minimally invasive or noninvasive skin-tightening procedures have become trends in facial and neck rejuvenation. Radiofrequency-assisted liposuction (RFAL) is a new choice for the treatment of skin relaxation that is more effective than noninvasive surgery without surgical incision.

OBJECTIVES

The authors recommend a 2-step method in which radiofrequency is applied after appropriate liposuction is performed. This approach is safer and more effective than traditional RFAL, and the authors detail the safety guidelines, operative techniques, postoperative satisfaction results, and complications.

METHODS

A total of 227 patients with lower face and neck skin laxity underwent RFAL between April 2012 and June 2019. The following data were collected: age, body mass index, operative duration, volume of fat aspirated, amount of energy delivered, and number and type of complications. Patient satisfaction was surveyed postoperatively and assessed by third-party surgeons at 3 and 6 months.

RESULTS

At 6 months after operation, 78.8% of patients considered the results moderate to excellent, whereas 21.2% of the patients considered the results to be poor or thought there was no change. The photograph evaluation performed by independent plastic surgeons showed moderate to excellent results in 89.1% of patients. There were no major complications that required further medical or surgical intervention.

CONCLUSIONS

This 2-step method is a safe and effective improvement in the application of radiofrequency for face and neck skin tightening. Patients can achieve significant contour correction via minimally invasive surgery with a lower risk of side effects.

LEVEL OF EVIDENCE: 4

Management of Articular Cartilage Defects in the Glenohumeral Joint

Articular cartilage defects are not often encountered in the glenohumeral joint. These lesions are typically found in patients with shoulder trauma, recurrent instability, or previous surgical treatment. Diagnosis can be difficult; these defects are often found incidentally during arthroscopic or open surgical management of other pathology. Initial management of isolated glenohumeral chondral defects is nonsurgical and includes physical therapy and/or corticosteroid injections. If nonsurgical treatment is unsuccessful, patients may undergo surgery. Because these lesions occur infrequently, few studies have documented surgical techniques and outcomes. Surgical strategies include arthroscopic débridement, microfracture surgery, osteochondral autograft or allograft transplantation, autologous chondrocyte implantation, and particulated juvenile allograft cartilage implantation.

Bipolar Radiofrequency Plasma-Mediated Ablation of Porcine Nasal Septal Cartilage: A Pilot Investigation

Background

The objectives of this pilot study were to (1) determine whether bipolar radiofrequency plasma-mediated ablation (PMA) can efficiently remove nasal septal cartilage and (2) calculate the ablation rate as a function of device power, probe force, and translation velocity using ex vivo porcine tissue.

Methods

Specimens were secured to a linear translation stage and were subjected to varying translation velocities (4, 7, and 12 cm/s), probe forces (140, 200, and 225 g), and bipolar radiofrequency generator (Coblator ENTec power settings, 38–58, 77–115, and 129–193 Watts root mean squared. Specimen mass loss and depth of ablation were measured using an analytic balance and dissection microscope, respectively.

Results

Visual and microscopic inspection revealed little char. Mass loss increased with decreasing translation velocity and increasing generator setting. Increasing probe force also influenced mass loss and increased crater depth. Depth of ablation did not correlate with translation velocity or generator setting.

Conclusion

PMA effectively ablates nasal septal cartilage and may be able to reduce or contour cartilaginous deformities and framework structures in the head and neck.

Osteochondral Graft Size Is Significantly Associated With Increased Force and Decreased Chondrocyte Viability

BACKGROUND

Insertion force has been shown to significantly reduce chondrocyte viability during osteochondral allograft transplantation. How graft size influences the required insertion force and chondrocyte viability has yet to be determined. Hypothesis/Purpose: The purpose was to characterize how graft size influences insertion force requirements and chondrocyte viability during osteochondral transplantation. The hypothesis was that larger grafts would require greater force and reduce chondrocyte viability.

STUDY DESIGN

Controlled laboratory study.

METHODS

Four graft sizes-15 × 5 mm, 15 × 10 mm, 25 × 5 mm, and 25 × 10 mm (diameter × depth)-were harvested from 13 thawed fresh-frozen human cadaveric distal femurs. Average, maximum, and cumulative force and number of impacts were recorded for 44 grafts by a surgical mallet embedded with a calibrated force sensor. In a separate experiment, fresh osteochondral tissues were subjected to mechanical loading. To capture a range of clinically important forces, categories were selected to correspond to impaction force data. Chondrocyte viability was assessed with confocal laser microscopy and live/dead staining.

RESULTS

Total force for all grafts averaged 4576 N. Median number of impacts for all grafts was 20 (range, 7-116). The mean number of impacts for 5-mm-deep grafts was 14.2 (95% CI, 10.8-18.6), as compared with 26.3 (95% CI, 19.9-34.4) for 10-mm-deep grafts ( P < .001). The mean cumulative force for 5-mm-deep grafts was 2128 N (95% CI, 1467-3087), as opposed to 4689 N (95% CI, 3232-6803) for 10-mm-deep grafts ( P = .001). For every 1 mm in graft depth, an average of 13.1% (95% CI, 6.2%-20.3%) more impacts are required when controlling for diameter and density ( P < .001). For every 1 mm in graft depth, the force required increases on average by 17.1% (95% CI, 7.7%-27.4%) when controlling for diameter and density ( P = .001). There was a significant reduction in chondrocyte viability for the forces required for graft thickness values >10 mm. Only forces associated with graft thickness <10 mm had chondrocyte viabilities consistently >70%.

CONCLUSION

Insertion force increases significantly with increasing graft depth. Controlling for diameter and bone density, a 1-mm increase in graft depth is associated with 13.1% more impacts and 17.1% more force. Chondrocyte viability was significantly reduced to <70% at average forces associated with grafts thicker than 10 mm.

CLINICAL RELEVANCE

Based on the current data, graft depth is an important consideration for surgeons when sizing osteochondral allograft transplant for chondral lesions of the knee.

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.

Radiofrequency energy in the arthroscopic treatment of knee chondral lesions: a systematic review

INTRODUCTION

Cartilage debridement is one of the recommended procedures for the management of chondral defects. Radiofrequency probes allow to debride the cartilage, but may induce subchondral bone necrosis.

SOURCES OF DATA

Medline, Cochrane and Google Scholar were searched to identify studies on arthroscopic debridement of the articular cartilage of the knee using radiofrequency chondroplasty. The methodological quality of the studies was assessed using the Coleman methodology score (CMS).

AREAS OF AGREEMENT

Monopolar and bipolar radiofrequency devices provide significantly better clinical outcomes, especially for patients with high-grade chondral lesions, compared with mechanical shaver only. Despite the original concerns regarding subchondral bone necrosis, low complication rates are reported.

AREAS OF CONTROVERSY

Heterogeneity in terms of type of device does not allow sound comparison of the published results. There is lack of evidence on the long-term effects of radiofrequency chondroplasty.

GROWING POINTS

Study methodology should be improved: the average Coleman methodology score was 56.2 out of 100.

RESEARCH

More comparative, well-designed and larger cohort trials are needed to ascertain whether radiofrequency chondroplasty offers long-term benefits over other simpler and more economical alternatives.

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.

Preliminary investigations on therapy thresholds for laser dosimetry, cryogen spray cooling duration, and treatment cycles for laser cartilage reshaping in the New Zealand white rabbit auricle

Previous studies have demonstrated the feasibility of laser irradiation (λ = 1.45 μm) in tandem with cryogen spray cooling (CSC) to reshape rabbit auricular cartilage using a total energy density of 14 J/cm(2). The aim of this study was to further explore and identify the dosimetry parameter space for laser output energy, CSC duration, and treatment cycles required to achieve shape change while limiting skin and cartilage injury. Ten New Zealand white rabbits were treated with the 1.45 μm diode laser combined with cryogen spray cooling (Candela Smoothbeam™, Candela Co., Wayland, MA, USA). The ear's central portion was bent around a cylindrical jig and irradiated in consecutive spots of 6 mm diameter (13 or 14 J/cm(2) per spot) along three rows encompassing the bend. CSC was delivered during irradiation in cycles consisting of 25-35 ms. At thin and thick portions of the ear, 4-7 and 6-10 treatment cycles were delivered, respectively. After surgery, ears were examined and splinted for 6 weeks. Treatment parameters resulting in acceptable (grades 1 and 2) and unacceptable (grade 3) skin injuries for thick and thin regions were identified, and shape change was observed. Confocal and histological analysis of cartilage tissue revealed several outcomes correlating to laser dosimetry, CSC duration, and treatment cycles. These outcomes included expansion of cartilage layers (thickening), partial cartilage injuries, and full-thickness cartilage injuries. We determined therapy thresholds for laser output energy, cryogen spray cooling duration, and treatment cycles in the rabbit auricular model. These parameters are a starting point for future clinical procedures aimed at correcting external ear deformities.

Regenerative and proliferative activities of chondrocyte based on the degree of perichondrial injury in rabbit auricular cartilage

Although the regeneration process for injured cartilage requires an intact perichondrium, few studies have addressed the importance of the intact perichondrial layer in the regeneration of damaged cartilage. In this study, we evaluated the role of the perichondrium on regenerative activities in injured cartilage according to different degrees of perichondrial injury. Auricular cartilage harvested from six New Zealand white rabbits was irradiated with a 1,460-nm diode laser at two different power settings (0.3 or 0.5 W). Irradiated cartilage was reimplanted into a subperichondrial pocket under three different conditions: non-injured perichondrium (NPI), unilaterally injured perichondrium (UPI), or bilaterally injured perichondrium (BPI). Rabbits were sacrificed at 1, 2, and 4 weeks after reimplantation and the auricular cartilage was reharvested. A histopathological study using hematoxylin and eosin staining, a live/dead viability assay, and immunohistochemical staining for proliferating cell nuclear antigen were performed to evaluate structural changes and regenerative and proliferative activities of the injured chondrocytes. A modified array and restored boundary of chondrocytes were observed in the NPI and UPI groups. Regeneration of chondrocytes was prominent in the NPI and UPI groups, but was not observed in the BPI group. Proliferative activity of chondrocytes was observed only when the perichondrium was preserved in the NPI and UPI groups. In contrast, proliferative activity was not observed until 4 weeks in the BPI group. The degree of perichondrial injury affected proliferation and regeneration in injured elastic cartilage. In the case of unilateral perichondrial injury, the surgeon should be careful to avoid damaging the other side of the perichondrium, because at least a unilateral perichondrial layer is needed for the regeneration of elastic cartilage.

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

Objectives

Cartilage reshaping by laser irradiation is used to correct septal and auricular cartilage deformities. Chondrocyte viability following laser irradiation and reshaping has been well established. However, the regeneration process of chondrocyte after laser irradiation has not been revealed yet. The aims of this study were to determine the mechanism of cartilaginous thermal injury and the regenerative process of damaged cartilage following laser irradiation.

Methods

Laser irradiation was performed on human septal cartilage and rabbit auricular cartilage using a 1,460-nm diode laser. We observed change in the shape of cartilage and evaluated the extent of cartilage injury using live/dead cell assay via confocal microscopy. Hoechst and propidium iodide (PI) staining was used to evaluate the mechanism of chondrocyte injury after laser irradiation. To evaluate the regeneration of cartilage, laser irradiated cartilages were reimplanted into a subperichondrial pocket and were harvested at 1, 2, and 4 weeks after reimplantation for viability assessment and histologic examination.

Results

Laser irradiation using a 1,460-nm diode laser produced a marked shape change in both human septal and rabbit auricular cartilages. Thermal damage on cartilage was correlated with the exposure time and the laser power. Hoechst and PI staining showed that chondrocyte death by laser irradiation was due to mainly necrosis, rather than apoptosis. In lower power treatment group (0.3 W and 0.5 W), all the chondrocytes regenerated within 4 weeks, however, in 1 W treatment group, chondrocytes could not regenerate until 4 weeks.

Conclusion

Reshaping of cartilage using 1,460 nm diode laser was attained concurrently with the thermal injury to the chondrocytes. The extent of thermal damage on chondrocytes was dependent on the exposure time and the laser power and the damaged chondrocytes irradiated with lower level of laser power could be regenerated after reimplantation into subperichondrial pocket.

Endoscopic approach for plantar fasciopathy: a long-term retrospective study

PURPOSE

The purpose of this study was to report the long term effectiveness of endoscopic plantar fascia release for recalcitrant plantar fasciopathy.

MATERIALS

Twenty-three consecutive patients underwent endoscopically-assisted plantar fascia release for symptomatic plantar fasciopathy unresponsive to nonoperative measures. The clinical diagnosis was supported by imaging (plain radiographs and magnetic resonance imaging [MRI]) and the American Orthopaedic Foot & Ankle Society (AOFAS) score was administered to all patients. All patients underwent endoscopic plantar fascia release. Postoperatively, patients were assessed at clinical examination and the AOFAS score was administered.

RESULTS

Twenty-two (26 feet) of the 23 patients included in our original cohort returned to our clinic at an average final follow-up of 9.6 years. The mean preoperative AOFAS score of 51 (range, 41-63) improved to 89 (range, 41-97) at the last follow-up, with no statistically significant difference between patients with or without calcaneal bone spur (p = 0.43). At the last appointment, physically active patients reported significantly higher AOFAS scores than sedentary patients (p = .008).

CONCLUSIONS

This endoscopic plantar approach could be a viable alternative to more invasive procedures for management of recalcitrant plantar fasciopathy. Future randomised controlled trials are needed.

Open technique is more effective than percutaneous technique for TOPAZ radiofrequency coblation for plantar fasciitis

BACKGROUND

Microtenotomy coblation using a radiofrequency (RF) probe is a minimally invasive procedure for treating chronic tendinopathy. It has been described for conditions including tennis elbow and rotator cuff tendinitis. There have been no long term studies to show its effectiveness in plantar fasciitis.

METHODS

A prospective non-randomised trial was conducted on 48 patients who had failed conservative treatment for plantar fasciitis, between 2007 and 2009. The procedure was performed using the TOPAZ microdebrider device (ArthroCare, Sunnyvale, CA), either via an open or a percutaneous method. Fifty-nine feet were treated and followed up for up to 1 year thereafter. Preoperative, 3, 6 and 12 months post-operative VAS pain, American Orthopaedic Foot-Ankle Society (AOFAS) hindfoot and SF-36 scores, patient expectation and satisfaction scores were analysed.

RESULTS

VAS scores improved significantly in both groups at 1-year follow-up. The open group had a more significant improvement in the VAS score at 1-year follow-up. AOFAS hindfoot scores improve significantly for both groups pre- and post-operatively, but there was no significant difference between both groups at the 1-year mark. SF-36 scores showed equally significant improvement in both groups 1 year post-operatively. Expectation and satisfaction scores were equally high in both arms.

CONCLUSIONS

TOPAZ RF coblation is a good and effective method for the treatment of recalcitrant plantar fasciitis. Clinical results improve with time for up to 1-year post-operatively. The open method seems to have a more significant improvement in pain VAS scores at 1-year postoperatively.

Effects of radiofrequency energy on porcine articular cartilage: higher-power settings in ablation mode show lower thermal radiation injury

PURPOSE

The purpose of this study was to compare the radiofrequency (RF) injury effect on cartilage in the different settings that are mostly used in clinical work under rigidly controlled laboratory conditions.

METHODS

Twelve fresh porcine knees were used in our study. Five treatment areas were created on the femoral condyles of each knee: the control group, coagulation (setting 2) group, coagulation (setting 7) group, ablation (setting 2) group, and ablation (setting 7) group. Hematoxylin/eosin staining, dual fluorescence staining, and the GAG content were observed to evaluate the histological cartilage changes, vacuolar cell rate of chondrocytes, depth of chondrocyte death, and detection of GAG content.

RESULTS

Vacuolar cell rates of chondrocytes in each experimental group were higher than that in the control group (P < 0.05); there was no significant difference in vacuolar cell rate among experimental groups. Dual fluorescent staining showed that the ablation (setting 7) group had a smaller depth of cell death than did the coagulation (setting 2) group (P < 0.05); the other experimental groups showed no statistically significant difference (n.s.). In addition, there was no significant difference in GAG content between the experimental groups and control group (n.s.).

CONCLUSIONS

The coagulation mode results in heavier thermal radiation injury to chondrocytes than does the ablation mode. Higher-power settings in the ablation mode result in lower thermal radiation injury and may be most suitable for cartilage debridement.

A review of the treatment methods for cartilage defects

The purpose of this article is to provide a broad review of the literature related to the treatment of cartilage defects and degenerated cartilage in animals with some inferences to the treatment in humans. Methods range from the insertion of osteochondral tissue or cells to the application of radio frequency or insertion of scaffolds and growth factors alone or in combination. Debridement, microfracture, radio frequency, and chondrocyte implantation are all methods normally utilized when treating smaller articular cartilage defects. Scaffolds and mosaicplasty are examples of methods to treat larger defects. This review will cover all major treatment methods currently used to treat articular cartilage defects.

The use of radiofrequency energy for arthroscopic chondroplasty in the knee

We present a review of the current literature surrounding the use of radiofrequency energy for arthroscopic chondroplasty in the knee. This review article summarizes basic science, clinical efficacy, and recent advances in the understanding of radiofrequency energy use for the treatment of chondral lesions. Laboratory evidence of increased mechanical stability and decreased release of inflammatory mediators associated with the use of radiofrequency energy chondroplasty is described with clinical evidence of decreased pain and increased functional scores when compared with mechanical chondroplasty. We re-examine concerns about the immediate side effects of radiofrequency energy use, including damage to local structures, in light of new potentially contradictory results, as well as the progression of techniques and probe design. However, although reported complications are few, because the quality of clinical evidence about safety and efficacy remains low, we suggest cautious and judicious use of this technology until future research has clearly defined the long-term clinical outcomes and risks.

Three-dimensional radiofrequency tissue tightening: a proposed mechanism and applications for body contouring

The use of radiofrequency energy to produce collagen matrix contraction is presented. Controlling the depth of energy delivery, the power applied, the target skin temperature, and the duration of application of energy at various soft tissue levels produces soft tissue contraction, which is measurable. This technology allows precise soft tissue modeling at multiple levels to enhance the result achieved over traditional suction-assisted lipectomy as well as other forms of energy such as ultrasonic and laser-generated lipolysis.

Complication of the use of a radiofrequency device in arthroscopic shoulder surgery: second-degree burn of the shoulder girdle

Radiofrequency ablation (RF) energy devices are increasingly being used in arthroscopic surgery. This is a case report of a 53-year-old man who had second-degree burns of the shoulder and chest wall as a result of fluid overheating due to RF. During an extensive arthroscopic bursal dissection of the left shoulder, the suction device on the RF wand and the valve was left open, allowing fluid to drip onto the chest and arm of the patient. Three days after his surgery, on his first postoperative visit, the dressings were removed, and the patient was noted to have severe blistering on the lateral aspect of his arm and on the anterolateral aspect of his left chest wall. One year after the surgery, he still had residual scarring that was only mildly intermittently pruritic. The use of RF during arthroscopic surgery is very useful clinically; however, it is important to have a strict understanding of the potential hazards the thermal energy can cause to the surrounding soft tissue.

Radiofrequency microtenotomy for the treatment of plantar fasciitis shows good early results

BACKGROUND

Microtenotomy coblation using a radiofrequency (RF) probe is a minimally invasive procedure for treating chronic tendinopathy. It has been described for conditions including tennis elbow and rotator cuff tendinitis. There have been no studies to show the effectiveness of such a procedure for plantar fasciitis.

METHODS

14 Patients with plantar fasciitis with failed conservative treatment underwent TOPAZ RF treatment for their symptoms between 2007 and 2008. The RF-based microdebridement was performed using the TOPAZ Microdebrider device (ArthroCare, Sunnyvale, CA). There were 6 men and 8 women with an average age of 44.0 years (23-57). There were 15 feet, with 6 right and 9 left feet. They were followed up for up to 6 months thereafter. Pre-operative, 3 and 6 months post-operative AOFAS ankle-hindfoot and SF-36 scores were analysed.

RESULTS

There was a significant improvement in mean pre-operative, post-operative 3- and 6-month AOFAS hindfoot scores from 34.47 to 69.27 and 71.33 (p=0.00) respectively. There was a significant decrease in SF-36 for bodily pain, and significant increases in physical and social function scores. 12 out of 14 (85.7%) patients reported good to excellent satisfaction results at 6 months, and 12 out of 14 (85.7%) patients have had their expectations met from the procedure at 6 months follow up.

CONCLUSION

TOPAZ RF coblation is a good and effective method for the treatment of recalcitrant plantar fasciitis. Early results are encouraging, and we will continue to assess the patients over a longer follow-up period.

Ablation of articular cartilage with an erbium:YAG laser: an ex vivo study using porcine models under real conditions-ablation measurement and histological examination

BACKGROUND AND OBJECTIVES

The use of an erbium:YAG laser in arthroscopic surgery has the advantage of a precise treatment of soft tissue. Due to the high absorption in water, the laser energy is perfectly matched to smoothing the hydrous, fibrillated articular cartilage surface. In minimal invasive surgery, the workspace is filled with aqueous liquids for enlargement. This appears contrary to the absorption characteristics of erbium:YAG laser radiation in water. The purpose of this study was to evaluate the ablated volume per pulse of cartilage lesions and the potential side effects including thermal damage and tissue necrosis.

STUDY DESIGN/MATERIALS AND METHODS

Twenty-four osteochondral specimens of porcine knee joints were irradiated with an Er:YAG laser completely submerged in water, with distances to the cartilage surface of 1, 3 and 5 mm and pulse durations of 75 and 100 microseconds. To keep a constant peak power of approximately 6 kW, pulse energies of 450 and 580 mJ were used at a pulse repetition rate of 15 Hz. After a histological preparation, ablated volumes, depths, and widths of the cuts were investigated. Additionally, laser protocols were correlated with different markers of cartilage tissue damage and apoptosis.

RESULTS

Ablation could be observed for every measurement. The influence of the distance showed a statistical significance (P < 0.001) for the volume, depth, and width of the cuts. For the pulse duration, statistical significance (P < 0.001) was found only for the volume and the depth. We observed no loss of proteoglycan or collagen type II. The total cell number, cell morphology, and number of apoptotic cells in an area close to the cutting edge and in a corresponding unaffected area of the same specimens revealed no differences regardless of the applied protocol.

CONCLUSION

The use of an Er:YAG laser demonstrates the successful application in liquid environments for cartilage removal without any damage of the surrounding tissue.

Comparison of intra-articular drilling and diode laser treatment for arthrodesis of the distal tarsal joints in normal horses

REASONS FOR PERFORMING STUDY

Anecdotal reports suggest that laser-facilitated arthrodesis of the distal tarsal joints improves the prognosis compared with intra-articular drilling but no objective comparisons have been performed.

OBJECTIVES

To evaluate intra-articular drilling and laser-facilitated arthrodesis using in situ and in vivo techniques.

METHODS

Fourteen cadaver limbs were evaluated in situ for chondrocyte viability after both surgical techniques. In vivo, one randomly selected limb was subjected to laser-facilitated arthrodesis and the other underwent intra-articular drilling in 6 normal horses. Clinical examinations were performed at 1, 3 and 5 months. Two horses were subjected to euthanasia at 1, 3 and 5 months.

RESULTS

Significantly more chondrocyte death was observed with laser-facilitated arthrodesis compared to drilling, but the overall degree suggested only a focal effect. In vivo, both groups demonstrated minimal post operative morbidity. There was more evidence of arthrodesis seen at all time points with intra-articular drilling.

CONCLUSIONS

This study demonstrated that changes associated with ultimate arthrodesis occur earlier after intra-articular drilling of the distal tarsal joints than laser-facilitated arthrodesis, although clinically affected horses may respond differently.

POTENTIAL RELEVANCE

Intra-articular drilling may provide earlier arthrodesis of the distal tarsal joints, but not necessarily a better long-term result.

The effect of early hyaluronic acid delivery on the development of an acute articular cartilage lesion in a sheep model

BACKGROUND

Partial-thickness articular cartilage lesions occur with knee trauma and may progress to osteoarthritis. This study evaluates the effectiveness of hyaluronic acid on cartilage healing after acute knee injury in sheep.

HYPOTHESIS

Early administration of hyaluronic acid to an acute cartilage injury will prevent chondrocyte death and improve cartilage metabolism.

STUDY DESIGN

Controlled laboratory study.

METHODS

A 10 x 10 mm partial-thickness articular cartilage lesion was created on the medial condyle of 16 adult sheep stifles (hindlimbs). Eight sheep received intra-articular hyaluronic acid injections at days 0, 8, and 15, and 8 controls received saline. Contralateral stifles were nonoperated controls. All sheep were sacrificed at 12 weeks after surgery. Synovial fluid was drawn before surgery and after euthanasia for collagen II, nitric oxide, and interleukin-1 beta analysis. The medial condyle was analyzed by gross appearance, confocal laser microscopy for cell viability, histologic analysis for cartilage morphology, and dimethylmethylene blue assay for proteoglycan.

RESULTS

At 12 weeks, histologic analysis revealed that the hyaluronic acid group had significantly better scores than the saline group (P = .001). The hyaluronic acid group had significantly greater glycosaminoglycan content than the saline group (P = .011), and showed a trend of reduced chondrocyte death compared with the saline group (P = .07). Synovial fluid showed no significant differences between the groups in collagen II, nitric oxide, and interleukin-1 beta levels.

CONCLUSION

The results demonstrated that early administration of hyaluronic acid shows a significant improvement in cartilage histologic analysis and increased glycosaminoglycan content after acute traumatic cartilage injury.

CLINICAL RELEVANCE

Early hyaluronic acid treatment for acute partial-thickness articular cartilage lesions may decrease or delay articular degeneration.

Glenohumeral chondrolysis after arthroscopy: a systematic review of potential contributors and causal pathways

PURPOSE

This systematic review provides (1) a synthesis of existing clinical evidence that helps identify factors associated with the development of glenohumeral chondrolysis after arthroscopy (PAGCL), (2) a consolidated conceptualization of potential causal pathways that elucidate proposed mechanisms leading to PAGCL, and (3) a summary of implications for practice, policy, and future research.

METHODS

A computerized literature review using an iterative search process identified 245 publications in English between January 1960 and April 2009. After we applied inclusion and exclusion criteria, 35 articles were stratified into 4 categories of factors related to PAGCL: (1) patient factors, (2) surgical factors (preoperative and intraoperative), (3) postoperative factors, and (4) causal pathways.

RESULTS

The majority of studies (61%) focused on surgical factors correlated with PAGCL, and most were laboratory based (n = 21). Publications involving human subjects were descriptive case reports (n = 15), not epidemiologic studies. A total of 88 patients (91 shoulder surgeries) with PAGCL were identified in case reports. The majority of patients (55%) was male, and the mean age was 27.9 years (range, 13.1 to 64 years). Among patients, 68% (n = 53) had implants/anchors, 67% (n = 59) received local anesthetics through a pain pump, and 45% (n = 41) had surgeries involving radiofrequency devices. The causal pathways to PAGCL likely involve initiating and secondary cartilage injury due to mechanical, thermal, or chemical events. The result is a cascade of interactive cellular responses that may include inflammation and chondrocyte apoptosis causing disturbance of cellular metabolism with subsequent loss of the gliding surface, congruity, and synovial fluid, leading to increased friction and accelerated wear that ultimately yield PAGCL.

CONCLUSIONS

The literature is limited to correlates, rather than true risk factors, for PAGCL. Well-designed epidemiologic studies that examine various exposures in relation to health outcomes, while controlling for potential confounders, are needed to determine relative risks that allow causal inference, thereby facilitating sound practice and policy decision making.

LEVEL OF EVIDENCE

Level IV, systematic review.

Factors influencing intra-articular fluid temperature profiles with radiofrequency ablation

BACKGROUND

Radiofrequency ablation devices are being used increasingly in arthroscopic surgery. However, there are concerns that excessive temperatures may damage the articular cartilage. The purpose of this study was to investigate the temperature profiles that occur within the glenohumeral space with the use of one commercially available radiofrequency ablation probe.

METHODS

Ten fresh-frozen human cadaver shoulder specimens were used. Intra-articular temperatures were measured at different time intervals over a two-minute period at a distance of 1, 3, 5, and 10 mm away from the probe. The radiofrequency probe was activated throughout the range of machine power settings, and irrigation fluid flow was varied (no flow, a flow at 60 mm Hg without suction, and a flow at 60 mm Hg with suction).

RESULTS

Temperatures deleterious to articular cartilage chondrocytes (i.e., those in excess of 50 degrees C) were seen with an increased duration of application, a decreased distance between the thermometer and the probe, and a decreased irrigation fluid flow rate. The highest recorded irrigation fluid temperature reached >80 degrees C after two minutes in a no-flow setting. The flow rate was found to be the most significant predictor of intra-articular temperature profiles. The various machine power settings had no apparent influence on temperature, meaning that higher probe settings are not necessarily associated with higher temperature profiles.

CONCLUSIONS AND CLINICAL RELEVANCE

These results demonstrate the importance of the management of the irrigation fluid flow rate across the joint during arthroscopic procedures that involve radiofrequency ablation. Even short intervals of limited flow could lead to supraphysiological temperature profiles and potentially to cartilage damage.

Radiofrequency application to the growth plate in the rabbit: a new potential approach to epiphysiodesis

BACKGROUND

Radiofrequency energy is being used more and more frequently in orthopaedics, mainly in the treatment of bone tumors. We postulated that radiofrequency ablation may produce growth plate lesions similar to those observed in the bone and conducted this study to see whether radiofrequency may be used as a technique for producing epiphysiodesis.

METHODS

We randomized 60 8-week-old female New Zealand white rabbits into 3 groups. Group A was destined for a total epiphysiodesis at 60 degrees C, group B was destined for a total epiphysiodesis at 90 degrees C, and group C for a lateral hemiepiphysiodesis at 90 degrees C. Radiofrequency energy was delivered in 1 minute in all 3 groups. Using fluoroscopic imaging, radiofrequency was applied percutaneously to the left proximal tibial physis whereas the right growth plate received a sham procedure. A bicortical pin was used to evaluate the longitudinal growth rate at every monthly radiologic control, beginning 8 weeks after the procedure. Comparisons between the right and left side and between groups A and B were achieved using a paired t test. A histopathologic study was conducted in parallel to the radiographic study.

RESULTS

In a radiograph at the 8-week point, pin migration was 4.74 mm on the left side compared with 9.72 mm on the right (P<0.0001), in group A. In group B, pin migration on the left was 1.37 mm compared with 5.49 mm on the right (P<0.0001). In group C, mean angular deviation was 11.6 degrees on the left compared with 1.9 degrees on the right (P=0.0001). These differences were maintained until the end of growth. Pathology specimens revealed cellular anarchy, loss of columnar stratification, and height of the physis on the left side, which occurred earlier and were more pronounced in group B than in group A. In group C, these changes involved only the lateral half of the left physis whereas its medial counterpart remained normal. There was no evidence of articular cartilage damage.

CONCLUSIONS

This experimental study shows that radiofrequency can efficiently and rapidly achieve epiphysiodesis. It is one of many methods that can be used for this purpose. The development of new electrodes suitable for use on human growth plates and the elaboration of specific utilization protocols may lead to its use in children. Its simplicity and precision may lead to a quick and efficient growth arrest with little pain and postoperative disability in addition to reduced costs.

CLINICAL RELEVANCE

Radiofrequency has proved to be effective in producing growth arrest in rabbits with no complications. Technical improvements and adaptations may allow its use for pediatric limb inequalities or angular deformities in the near future.

Thermoforming of tracheal cartilage: viability, shape change, and mechanical behavior

BACKGROUND AND OBJECTIVES

Trauma, emergent tracheostomy, and prolonged intubation are common causes of severe deformation and narrowing of the trachea. Laser technology may be used to reshape tracheal cartilage using minimally invasive methods. The objectives of this study were to determine: (1) the dependence of tracheal cartilage shape change on temperature and laser dosimetry using heated saline bath immersion and laser irradiation, respectively, (2) the effect of temperature on the mechanical behavior of cartilage, and (3) tissue viability as a function of laser dosimetry.

MATERIALS AND METHODS

Ex vivo rabbit trachea cartilage specimens were bent and secured around a cylinder (6 mm), and then immersed in a saline bath (45 and 72 degrees C) for 5-100 seconds. In separate experiments, tracheal specimens were irradiated with a diode laser (lambda = 1.45 microm, 220-400 J/cm(2)). Mechanical analysis was then used to determine the elastic modulus in tension after irradiation. Fluorescent viability assays combined with laser scanning confocal microscopy (LSCM) were employed to image and identify thermal injury regions.

RESULTS

Shape change transition zones, between 62 and 66 degrees C in the saline heating bath and above power densities of 350 J/cm(2) (peak temperatures 65+/-10 degrees C) for laser irradiation were identified. Above these zones, the elastic moduli were higher (8.2+/-4 MPa) than at lower temperatures (4.5+/-3 MPa). LSCM identified significant loss of viable chondrocytes within the laser-irradiation zones.

CONCLUSION

Our results indicate a change in mechanical properties occurs with laser irradiation and further demonstrates that significant thermal damage is concurrent with clinically relevant shape change in the elastic cartilage tissues of the rabbit trachea using the present laser and dosimetry parameters.

Viability of human septal cartilage after 1.45 microm diode laser irradiation

BACKGROUND AND OBJECTIVES

Chondrocyte viability following laser irradiation and reshaping has not been established for human nasal septal cartilage. Knowledge of the relationship between thermal injury and laser dosimetry is needed in order to optimize septal laser cartilage reshaping. The objective of this study was to determine the depth and width of thermal injury in human septal cartilage following laser irradiation.

STUDY DESIGN/MATERIALS AND METHODS

Excess fresh nasal septal cartilage sections from rhinoplasty or septoplasty operations were irradiated using a 1.45 microm diode laser 1.25-3.6 W (2.8 mm spot diameter) with 1 second fixed exposure time, and then at exposure times of 1-4 seconds for a fixed power of 1.25 W. An infrared camera recorded surface temperature profiles during irradiation, and the temperature data were incorporated into a rate process model to numerically estimate thermal damage. Calcein AM and ethidium homodimer-1 fluorescent dyes combined with confocal laser microscopy (CLM) were used to measure thermal damage.

RESULTS

CLM demonstrated clear demarcation between dead and living cells following irradiation. The extent of non-viable chondrocyte distributions increased with power and exposure time. The maximum depths of injury were 1,012 and 1,372 microm after 3.6 W 1 second and 1.25 W 4 seconds irradiation respectively. The damage predictions made by the rate process model underestimated thermal injury when compared with CLM measurements.

CONCLUSIONS

The assay system identified regions of non-viable chondrocytes in human septal cartilage and defined how thermal injury varies with dosimetry when using a 1.45 microm diode laser.

Risk of osteonecrosis of the femoral condyle after arthroscopic chondroplasty using radiofrequency: a prospective clinical series

Radiofrequency (RF) energy can be used for treatment of intraarticular pathologies in knee joint. RF energy was found to be superior to mechanical techniques in smoothening the articular surface (chondroplasty), shortening the operation time and reducing the blood loss. As RF produces thermal energy it has been reported to be responsible for the postoperative osteonecrosis however, there is no clinical evidence in the literature supporting that RF causes osteonecrosis. The current study searches for an answer whether surgical arthroscopic modalities using RF energy causes osteonecrosis. We hypothesize in the presented study that chondroplasty with RF has no effect on increasing the incidence of osteonecrosis in knee joint. In a prospective clinical trial, arthroscopic chondroplasty was performed in 50 patients with degenerative changes of the articular cartilage, stage II and III according to Outerbridge. To be included in the study, the patients had to meet the following criteria: (1) Preoperative MRI and plain film radiographs showing no evidence of osteonecrosis. (2) Patients had to be symptomatic for at least 6 weeks before the preoperative MRI. (3) Arthroscopically confirmed stage II or III. Preoperative MRI was taken in all patients. For chondral lesions bipolar RF energy system (VAPR-DePuy Mitek, Norwood, USA) was used. The patients were examined at the end of the sixth month and we performed MRI. Fifty patients with an average of age 45.54 (between 18 and 64) (SD, 10.63). During arthroscopy, together with chondropathy 22 patients pure medial meniscus tears, 7 patients medial and lateral meniscus tears, 7 patients pure lateral meniscus tears, 2 patients medial plica, and 3 patients synovial hypertrophy were detected. Among all 50 patients, osteonecrosis were detected at only 2 (4%) in the postoperative period. Until now it was not clear that RF energy causes osteonecrosis; however, according to this study if proper method is used, bipolar RF energy used for arthroscopic chondroplasty does not causes subchondral osteonecrosis.

Arthroscopic knee chondroplasty using a bipolar radiofrequency-based device compared to mechanical shaver: results of a prospective, randomized, controlled study

Both mechanical shavers and radiofrequency-based devices are used to treat symptomatic partial thickness chondral lesions. Controversy exists as to which mode of treatment provides better outcomes. The purpose of this study was to compare clinical results after bipolar radiofrequency-based chondroplasty (RFC) to mechanical shaver debridement (MSD). Patients (n = 60) included in the study presented with knee pain associated with a medial meniscus tear and idiopathic ICRS grade III defect of the medial femoral condyle. Patients who had osteoarthritis, grade II or higher cartilage defects of the tibial joint surface, the lateral compartment, or the femoro-patellar joint, or had previously undergone surgery on the affected knee were excluded. Patients underwent partial meniscectomy; during the procedure, they were randomly assigned to receive bipolar RFC (Paragon, ArthroCare Corporation, Austin, TX) or MSD (Full radius resector LR 4.85 x 12.5 cm), Arthrex, Naples, FL). Postoperatively, the same physiotherapist provided instructions for a daily 2-h home training program consisting of isometric, isotonic, and leg lifting exercises; patients were provided the option of using crutches. Clinical outcomes were assessed using the Tegner score, visual analogue scale (VAS) score, and Knee and Osteoarthritis Outcome Score (KOOS) assessment, which consists of five principal domains including pain, symptoms, function in daily living (ADL), and knee related quality of life (QOL), where a score of 0 indicates extreme symptoms and 100 represents no symptoms. Age and time from injury onset did not differ significantly between the RFC and MSD groups (43 +/- 10 vs. 44 +/- 9 years, P = 0.732; 8 +/- 3 vs. 7 +/- 4 months, P = 0.279). No complications or adverse events were observed. Preoperatively, mean (+/-SD) scores for all KOOS principal domains were <20 and did not differ significantly (P > 0.05) between treatment groups. Postoperatively, the RFC patients returned to activity significantly earlier than MSD patients (17 +/- 7 vs. 22 +/- 6 days, P = 0.002). VAS pain scores at 6 h, 24 h, 6 weeks, and 1 year were significantly (P < 0.001) lower for the RFC group than for the MSD group (4 +/- 2, 2 +/- 0.5, 2 +/- 1, 2 +/- 1 vs. 8 +/- 1, 4 +/- 1, 4 +/- 1, 3 +/- 1, respectively). At 1 year, RFC patients had significantly better Tegner score (4.1 +/- 0.8 vs. 2.8 +/- 0.6, P < 0.001) and KOOS domain scores for pain, symptoms, ADL, QOL, respectively (81.1 +/- 8, vs. 59.4 +/- 12.8; 80.7 +/- 7.5 vs. 59.6 +/- 7.5; 81.5 +/- 6.5 vs. 60.1 +/- 6.9; 80 +/- 10 vs. 61.3 +/- 12.5; P < 0.001) than MSD patients. Significantly fewer RFC patients (2% vs 23%, p = 0.026) reported using NSAIDS for knee pain at 1 year. Patients undergoing radiofrequency-based chondroplasty for ICRS grade III medial femoral condyle chondral lesions in conjunction with partial meniscectomy had significantly better clinical outcomes through 1 year than patients with similar pathology receiving chondral debridement using the mechanical shaver.

Ex vivo comparison of mechanical versus thermal chondroplasty: assessment of tissue effect at the surgical endpoint

PURPOSE

The purpose of this study was to evaluate tissue effect (tissue removal plus underlying cell death) of two chondroplasty techniques: mechanical debridement (MD) using a rotary shaver blade and thermal chondroplasty using radiofrequency energy (RFE).

METHODS

Forty-eight human chondromalacic cartilage samples were treated with either MD or RFE. Pre- and post-treatment arthroscopic images of the cartilage surface were recorded. Samples were incubated with cell viability stain and visualized with confocal laser microscopy to determine tissue effect. Smoothing was quantitated by three surgeons using a visual analog scale (VAS) as well as a subjective rating regarding whether smoothing was "arthroscopically acceptable."

RESULTS

Tissue effect at the surgical endpoint of arthroscopically acceptable smoothing was 385 microm for MD versus 236 microm for RFE, a significant difference (P < .0001). Mean post-treatment VAS for MD was 2.8 points less smooth than for RFE (P < .0001). Overall, arthroscopically acceptable smoothing was achieved in 90% of RFE samples compared to 49% of MD samples.

CONCLUSIONS

Our results shown that chondroplasty using a RFE probe results in greater smoothing of chondromalacic cartilage in fewer treatment passes and with decreased total tissue effect than MD using a rotary shaver blade.

CLINICAL RELEVANCE

If safety and efficacy can be shown in vivo, thermal chondroplasty may represent an alternative for treatment of symptomatic chondromalacia.

Young patients with shoulder chondrolysis following arthroscopic shoulder surgery treated with total shoulder arthroplasty

Chondrolysis following shoulder arthroscopy is a devastating complication, often seen in young patients. After nonoperative measures have been exhausted, there are few treatment options available that reliably improve pain and function. The purpose of this study is to examine the intra-operative findings, radiographic features, and clinical outcomes of a series of patients with chondrolysis following arthroscopic surgery managed with a total shoulder arthroplasty. A retrospective review was performed on 11 patients (average age 39) with shoulder chondrolysis following arthroscopy. Attention was focused on review of the index arthroscopy, radiographs, and functional outcome scores prior to total shoulder arthroplasty, as well as intra-operative cultures, histology, radiographs, and functional outcomes from most recent follow-up. All patients were treated with total shoulder arthroplasty at an average of 26 months after the index arthroscopy. Preoperative and postoperative radiographs were reviewed, and outcomes were compared using validated measurements. Statistically significant improvements in shoulder abduction (89 degrees -123 degrees , P = .027), external rotation (26 degrees -48 degrees , P = .037), total ASES scores (30-77.5, P = .0039), and SST scores (3-8, P = .0078) were noted. Ten patients subjectively rated their outcomes as good or excellent, with 1 as satisfactory. Chondrolysis after shoulder arthroscopy has a rapid clinical progression and is likely multifactorial in etiology. Early results of total shoulder arthroplasty show an opportunity for improvements in pain and function; however, progressive glenoid radiolucencies may develop in these patients.

Articular cartilage thickness of the humeral head: an anatomic study

This study determined the thickness of normal humeral head articular cartilage by anatomic cross section using computer-aided image analysis software. Sixteen adult cadaveric humeral heads were analyzed. Our findings reveal that the thickness of humeral articular cartilage is substantially thinner than articular cartilage found in the knee. The cartilage is thickest in the central portion of the head and becomes progressively thinner towards the periphery. Surgical techniques used to treat pathology in the glenohumeral joint, specifically thermal energy or mechanical debridement, may have deleterious effects on the relatively thin humeral articular cartilage.

Postarthroscopic glenohumeral chondrolysis

BACKGROUND

Recent reports have noted the appearance of postarthroscopic glenohumeral chondrolysis. Although this devastating process has been identified, no cause has been directly identified.

HYPOTHESIS

A cause of postarthroscopic glenohumeral chondrolysis will be associated with a specific factor (ie, implanted device, surgical technique, etc), and this factor can be identified by a review and comparison of cases seen in the senior author's office.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Analyze possible etiologic factors with imaging studies, demographics, history, and physical examinations of 10 patients (12 shoulders) with postarthroscopic glenohumeral chondrolysis, and then compare perisurgical information with a focused chart review and comparison with the rest of the 177 arthroscopic shoulder surgeries in the same period of time.

RESULTS

There were 12 cases of postarthroscopic glenohumeral chondrolysis (all were the senior author's patients). Four common factors were identified, and only high-flow intra-articular pain pump catheters filled with bupivacaine and epinephrine were a new addition to years of shoulder surgery by the senior author; 177 shoulders underwent arthroscopy in the identified time frame, and only 19 shoulders, of 30 with capsular procedures, had intra-articular pain pump catheters filled with bupivacaine and epinephrine. Of these, 12 have been identified with chondrolysis.

CONCLUSION

Use of intra-articular pain pump catheters eluting bupivacaine with epinephrine appear highly associated with postarthroscopic glenohumeral chondrolysis.

CLINICAL RELEVANCE

Intra-articular pain pump catheters, especially those eluting bupivacaine with epinephrine, should be avoided until further investigation.

Arthroscopic evaluation of radiofrequency chondroplasty of the knee

BACKGROUND

Considerable debate exists over the use of radiofrequency-based chondroplasty to treat partial-thickness chondral defects of the knee. This study used second-look arthroscopy to evaluate cartilage defects previously treated with bipolar radiofrequency-based chondroplasty.

HYPOTHESIS

Partial-thickness articular cartilage lesions treated with bipolar radiofrequency-based chondroplasty will show no progressive deterioration.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

One hundred ninety-three consecutive patients underwent bipolar radiofrequency-based chondroplasty over 38 months; 15 (25 defects treated with bipolar radiofrequency-based chondroplasty) underwent repeat arthroscopy for recurrent or new injuries. Time from the initial to repeat arthroscopy ranged from 0.7 to 32.7 months. At both procedures, the location, size, grade, and stability of lesions were evaluated, recorded, and photographed arthroscopically.

RESULTS

At the initial procedure, 25 lesions treated using bipolar radiofrequency-based chondroplasty ranged from 9 to 625 mm2 (mean, 170.2 +/- 131.2 mm2; median, 120 mm2); at second look, lesion size was 9 to 300 mm2 (mean, 107.7 +/- 106.7 mm2; median, 100 mm2). At second look, 3 (12%) demonstrated unstable borders with damage in the surrounding cartilage that appeared to be progressive. Eight (32%) lesions were unchanged in size. Eight (32%) demonstrated partial filling with stable repair tissue, and 6 (24%) demonstrated complete filling with stable repair tissue. Lesions in the tibiofemoral compartments showed better response to radiofrequency chondroplasty than did those within the patellofemoral joint (P < .05).

CONCLUSION

Only 3 of 25 lesions demonstrated progression. More than 50% showed partial or complete filling of the defect. Bipolar radiofrequency chondroplasty is an effective way to treat partial-thickness cartilage lesions; however, long-term effects of this treatment on cartilage remain unknown.

Mechanical chondroplasty: early metabolic consequences in vitro

PURPOSE

The purpose of this study was to determine the depth of penetration from mechanical chondroplasty and metabolic consequences of this procedure on the remaining articular cartilage.

METHODS

Mechanical chondroplasty was performed in vitro on a portion of fresh grade I or II articular cartilage from 8 human knee arthroplasty specimens. Treated and control (untreated) explants (approximately 30 mg) were cut from the cartilage. The explants were divided into 2 groups, day 1 and day 4, placed separately in a 48-well plate containing media, and incubated at 37 degrees C for 24 hours. After the 24-hour incubation, the explants were weighed on day 1 and day 4, and explant media were removed and tested for total proteoglycan synthesis and aggrecan synthesis. At time 0, 2 sets (2.6 mm each) of treated and control cartilage slices were cut with a precision saw. One set was stained for confocal laser microscopy via a cytotoxicity stain to determine cell viability. The second set was stained with H&E to determine depth of penetration.

RESULTS

The mean depth of penetration was 252.8 +/- 78 microm. There was no significant difference (P > .25) between total proteoglycan synthesis for control versus treatment groups on day 1 or 4. Aggrecan synthesis was significantly reduced on day 1 when normalized for tissue weight (P = .019) and double-stranded deoxyribonucleic acid (P = .004). On day 4, no significant difference was detected. Confocal laser microscopy did not show cell death below the zone of treatment.

CONCLUSIONS

There was no significant metabolic consequence caused by chondroplasty to the remaining articular cartilage, and the zone of injury was limited to the treatment area.

CLINICAL RELEVANCE

Mechanical chondroplasty causes no significant metabolic consequences to articular cartilage under these conditions.

Chondrolysis of the glenohumeral joint following arthroscopic capsular release for adhesive capsulitis: a case report

This is a case of glenohumeral chondrolysis, following arthroscopy for adhesive capsulitis of the shoulder, during which, capsular release has been performed using a bipolar radio frequency energy probe. Heat produced during the procedure by the radio frequency energy probe, probably was the reason behind the occurance of such a rare pathological entity. Chondrolysis has to be put on the top of the list of complications that may occur following arthroscopy, whenever radio frequency energy tools are used. This is not because it is a common one, but because of the difficulty in managing it.

Comparison of mechanical debridement and radiofrequency energy for chondroplasty in an in vivo equine model of partial thickness cartilage injury

OBJECTIVE

The purpose of this study was to develop a long-term model of cartilage injury that could be used to compare the effects of radiofrequency energy (RFE) and mechanical debridement as a treatment.

METHODS

Partial thickness fibrillation of patellar cartilage was created in 16 mature ponies. Three months after the initial surgery all injured patellae were randomly selected to receive one of the four treatments (n = 8/treatment): (1) control, (2) mechanical debridement with a motorized shaver, (3) TAC-CII RFE probe, and (4) CoVac 50 RFE probe. The ponies were euthanized 22 months after treatment. Macroscopic appearance of the cartilage surface was scored, vital cell staining was used to determine chondrocyte viability and light microscopy was used to grade the morphometric changes within the cartilage. Mechanical properties (aggregate modulus, Poisson's ratio and permeability) also were determined and compared to normal uninjured cartilage.

RESULTS

There were no differences in the cartilage surface scores among the treatment groups and control samples (P > 0.05). The maximum depth of cell death and the percentage of dead area in control and mechanical debridement groups were significantly less than those in both RFE groups. There were no significant differences in maximum depth and the percentage of dead area between the two RFE treatment groups. Histologic scores demonstrated better cartilage morphology for the control and mechanical debridement groups than those of RFE groups. However, even with full thickness chondrocyte death, the matrix in the RFE treated sections was still retained and the mechanical properties of the treated cartilage did not differ from the mechanical debridement group.

CONCLUSION

RFE caused greater chondrocyte death and more severe morphological changes compared to untreated degenerative cartilage and mechanical debridement in this model.

Effects of thermal energy on chondrocyte viability

OBJECTIVE

To determine the critical temperature that reduces chondrocyte viability and evaluate the ability of chondrocytes to recover after exposure to the critical temperature.

SAMPLE POPULATION

Cartilage explants obtained from the humeral heads of 30 sheep.

PROCEDURES

In a randomized block design, 318 full-thickness cartilage explants were collected from 30 humeral heads of sheep and cultured for up to 14 days. On the first day of culture (day 0), explants were subjected to temperatures of 37 degrees , 45 degrees , 50 degrees , 55 degrees , 60 degrees , or 65 degrees C for 5 minutes by heating culture tubes in a warming block. The ability for chondrocytes to recover after exposure to the critical temperature was determined by evaluating viability at days 0, 1, 3, 7, and 14 days after heating. Images were analyzed by use of confocal laser microscopy.

RESULTS

Analysis of images revealed a significant decrease in live cells and a significant increase in dead cells as temperature increased. Additionally, the deepest layer of cartilage had a significantly lower percentage of live cells, compared with values for the 3 most superficial layers. Chondrocytes did have some ability to recover temporarily after the initial thermal insult.

CONCLUSIONS AND CLINICAL RELEVANCE

A strong relationship exists between increasing temperature and cell death, with a sharp increase in chondrocyte death between 50 degrees and 55 degrees C. Chondrocytes in the deepest cartilage layer are most susceptible to thermal injury. The threshold of chondrocyte recovery from thermal injury is much lower than temperatures reached during chondroplasty by use of most radiofrequency energy devices.

Treatment of grade III femoral chondral lesions: mechanical chondroplasty versus monopolar radiofrequency probe

PURPOSE

Articular cartilage defects are commonly found on the femoral condyle, and their treatment with thermal energy is thought to provide a smoother surface, sealing the damaged articular cartilage and possibly decreasing the progression of these lesions. Reports of femoral avascular necrosis (AVN) developing after bipolar thermal chondroplasty are worrisome. The purpose of this study was to compare the effects on subchondral bone and the early clinical effectiveness of mechanical shaving versus mechanical shaving plus monopolar radiofrequency (MRF) on grade III femoral chondromalacia.

TYPE OF STUDY

Randomized, prospective, controlled trial.

METHODS

In this trial 60 subjects were treated by either mechanical shaving alone (n = 30) or mechanical shaving plus MRF (n = 30). Preoperative and 12-month postoperative magnetic resonance imaging (MRI) evaluations and Tegner, Lysholm, Cincinnati, International Knee Documentation Committee, and visual analog scale assessments at 12 and 24 months were obtained.

RESULTS

Of the subjects, 56 were available for the final analysis (28 treated by shaver and 28 treated by shaver plus MRF). Baseline demographics were similar between treatment groups. Postoperative MRI findings were similar between groups, including no incidents of AVN. At a mean of 19 months postoperatively, Tegner, Lysholm, Cincinnati, International Knee Documentation Committee, and visual analog scale assessments improved significantly from pretreatment levels in both groups. No difference in mean improvement was observed between groups.

CONCLUSIONS

The primary endpoint was to look for AVN. No subchondral bone effects attributable to either mechanical shaving or radiofrequency energy were noted. The secondary endpoint was a clinical evaluation. Both groups showed significant improvements in pain and function outcomes with no discernible differences between groups. The use of monopolar radiofrequency as an adjuvant to mechanical chondroplasty with a shaver for the treatment of grade III chondral lesions did not affect MRI findings or pain and function outcomes when compared with mechanical chondroplasty by use of a shaver only.

LEVEL OF EVIDENCE

Level II, randomized controlled trial with confidence intervals not reported.

An ex vivo thermal chondroplasty model: the association of a char-like layer and underlying cell death

PURPOSE

The purpose of this study was to evaluate the relation between the char-like layer observed during radiofrequency energy (RFE) treatment of cartilage and the depth of underlying cell death.

METHODS

Healthy adult bovine patellae were treated with a monopolar RFE probe ex vivo at generator settings of 20, 30, 40, 50, 60, 80, and 110 in cut mode. The presence or absence of a char-like layer and visual electrical discharge was noted. Treated tissue was incubated with cell viability stain, and the depth of cell death and matrix debridement was measured from confocal laser microscopy images.

RESULTS

At generator settings of 60 and above, a char-like layer, electrical discharge, and matrix debridement were consistently observed, and the depth of cell death was significantly less (P < .05) than when these features were not observed (< or =30). Paradoxically, the least depth of cell death did not occur at the lowest generator setting in cut mode. It occurred at a generator setting of 60. An increase in impedance of the system and a decrease in current were also associated with reduced cell death.

CONCLUSIONS

In this controlled ex vivo study formation of a char-like layer, visual electrical discharge, increased impedance, and reduced current were associated with less depth of cell death when cartilage was treated with monopolar RFE.

CLINICAL RELEVANCE

This study suggests that a char-like layer and electrical discharge during RFE treatment of cartilage may be advantageous because, potentially, these features are associated with less depth of cell death (safety) and greater matrix debridement (efficacy).

Osteonecrosis of the knee after laser or radiofrequency-assisted arthroscopy: treatment with minimally invasive knee arthroplasty

BACKGROUND

Osteonecrosis of the knee after various arthroscopic procedures associated with the use of laser or radiofrequency devices has been described in a few case reports. The purpose of this study was to report on a series of nineteen patients with osteonecrosis of the knee after arthroscopic procedures. A literature search was done to compare this series of patients to previously reported cases. In addition, we analyzed the outcome after treatment with minimally invasive knee arthroplasty.

METHODS

We studied patients who had development of osteonecrosis of the knee after a routine arthroscopic procedure. Preoperative and postoperative clinical notes, radiographs, and magnetic resonance images of patients were analyzed. Only those patients with no evidence of osteonecrosis on preoperative magnetic resonance imaging who later had development of osteonecrosis and subsequently required a knee arthroplasty were included. We conducted a search of the current literature to compare the results seen in our patient population with those seen in other patients with this entity. Patients were followed both clinically and radiographically for a mean of sixty-two months.

RESULTS

A total of nineteen patients met the inclusion criteria. There were fourteen women and five men with a mean age of sixty-nine years. Six patients underwent an arthroscopy with associated holmium or yttrium-aluminum-garnet laser treatment, ten patients had associated radiofrequency treatment, and three patients had microfracture surgery. Subsequent arthroplasty procedures included four unicompartmental knee arthroplasties and fifteen tricompartmental knee arthroplasties. At the time of final follow-up, the mean Knee Society objective score was 95 points.

CONCLUSIONS

Arthroscopic procedures may play a role in the development of osteonecrosis of the knee. To our knowledge, this is the largest series of patients to have development of this condition after arthroscopy with associated laser, radiofrequency, or microfracture surgery. The midterm results of knee arthroplasty in this unique patient population are comparable with those of patients undergoing knee arthroplasty for osteoarthritis of the knee.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions to Authors on jbjs.org for a complete description of levels of evidence.

Development of partial thickness articular cartilage injury in an ovine model

The purpose of this study was to create a controlled partial thickness cartilage lesion in a sheep model, and to provide a foundation to study the natural history of the progression of this lesion. Twenty-eight sheep divided into four groups (1, 12, 24, and 52 weeks, n=7/group) were used in this study. In one stifle, a mechanical tool was used to create a 200 microm partial thickness lesion (1.5x1.5 cm2) on the medial femoral condyle via arthroscopy. Joint fluid was drawn presurgery and after euthanasia for analysis of collage II 3/4 C (long) (C2C). After euthanasia, the condyle was analyzed by gross appearance, confocal laser microscopy (CLM) for cell viability, scanning electronic microscopy (SEM) for surface roughness, Artscan for cartilage stiffness, and histology for cartilage morphology. The gross appearance of the treated area appeared rough, soft, and swollen compared to untreated control over time. CLM demonstrated that the depth of cell death increased to 590 microm at 52 weeks after surgery. SEM demonstrated that the treated area became more irregular over time. Stiffness of the treated area was significantly less than control by 12 weeks after surgery. Histologic analysis demonstrated that the 12, 24, and 52 week groups had significantly poorer histologic scores than the 1 week group. Joint fluid analysis demonstrated that the treatment group at 1 week had significant higher levels of C2C than the pretreatment baseline data. The results of this study demonstrated that partial thickness injury of cartilage continued to propagate and degenerate over time in this sheep model. Options for the prevention or treatment of this lesion may be tested using this model in the future.