Effect of simulated shoulder thermal capsulorrhaphy using radiofrequency energy on glenohumeral fluid temperature

The Arthroscopic Application of Radiofrequency in Treatment of Articular Cartilage Lesions

Articular cartilage lesion is a common disease to be treated by arthroscopic surgery. It will eventually progress to osteoarthritis without proper management, which can affect patients’ work and daily life seriously. Although mechanical debridement and laser have been used clinically for its treatment, due to their respective drawbacks, radiofrequency has drawn increasing attention from clinicians as a new technique with more advantages. However, the safety and efficacy of radiofrequency have also been questioned. In this article, the scope of application of radiofrequency was reviewed following an introduction of its development history and mechanism, and the methods to ensure the safety and effectiveness of radiofrequency through power and temperature control were summarized.

Analysis of parameters influencing intraarticular temperature during radiofrequency use in shoulder arthroscopy

PURPOSE

The aim of this study was to analyze the influence of several factors on the temperature in the work chamber during shoulder arthroscopy procedures in order to identify danger zones when using radiofrequency.

METHODS

Intraarticular temperature was measured intraoperatively using system with special probe that directly measured the temperature in 22 patients. Data collection was prospective. The main parameters studied were the measurement of the temperature depending on: localization of the procedure (glenohumeral or subacromial), the use of coagulation or ablation, the number of portals, the pressure of the arthropump, the time of use, the blood pressure and the temperature of the operating room.

RESULTS

Ninety-three recordings were made. No complications were identified. Addition of a portal reduces the average elevation of 3.8 °C (p < 0.05). Ambient temperature above 19.15 °C with two portals leads to an average increase of 13.3 °C (p < 0.05). Increasing the pressure of the arthropump of 10 mmHg increases the temperature of 0.8 °C (p < 0.05). No significant difference was found on the change in blood pressure, location and mode of use.

CONCLUSIONS

These results show the interest of controlling these factors when performing shoulder arthroscopy procedure. This study identifies situations of high joint risk when using radiofrequency and thus to prevent secondary complications such as burns and massive chondrolyses.

Etiology of Shoulder Arthritis in Young Patients

The manifestation of glenohumeral arthritis in the young adult is a devastating occurrence that can be difficult to manage. This review details the many underlying etiologies including genetic causes, congenital abnormalities, glenohumeral instability, posttraumatic lesions, postcapsulorraphy arthropathy, osteonecrosis, intraarticular pain pump postoperative use, radiofrequency/thermal capsulorraphy treatments, septic arthritis/infection, and inflammatory arthropathies. Although each of these potential causes have been well-studied, their contributions to the development of glenohumeral arthritis in the young person has not been described extensively.

Subacromial temperature profile during bipolar radiofrequency use in shoulder arthroscopy. Comparison of Coblation® vs. VAPR®

BACKGROUND

The use of bipolar electrodes for arthroscopic procedures carries a theoretical ex vivo risk of inducing burn injuries. Few studies have measured the in vivo temperatures produced by bipolar electrodes during arthroscopy, and their results are conflicting. The objective of this study was to evaluate the temperature profile within the subacromial space during shoulder arthroscopy with two different electrode systems.

HYPOTHESIS

The primary hypothesis was that the two electrode systems produced similar temperature variations and peak temperatures. The secondary hypothesis was that neither electrode system produced irrigation-fluid temperatures above the tissue-damage threshold.

MATERIAL AND METHODS

A comparative, prospective, single-centre, single-surgeon, single-blind study was conducted to compare the Coblation^® system (Smith&Nephew, Andover, MA, USA) and the VAPR^® system (DePuy Synthes Mitek Sports Medicine, Raynham, MA, USA) in 13 patients undergoing shoulder arthroscopy. A temperature probe inserted into the subacromial space was used to record temperatures at 10-second intervals for 60seconds during continuous radiofrequency application.

RESULTS

Mean baseline temperature was 21.4±0.7°C with VAPR^® and 23.0±2.2°C with Coblation^®. No significant between-group differences were found during the first 40seconds. The mean peak temperature reached after 60seconds was 25.0±1.9°C with VAPR^® and 27.9±2.8°C with Coblation^® (P<0.05).

DISCUSSION

Few studies have compared the in vivo temperatures produced during arthroscopy by different electrode systems. In vivo studies have established that temperature increases can cause tissue damage, particularly to chondrocytes, and that the irrigation flow rate plays a key role in lowering the in vivo temperatures. Our study showed a significant difference between the two electrode systems after 50seconds of use, with lower temperatures with the VAPR^®. Nevertheless, neither system increased the irrigation-fluid temperatures above the tissue-damage threshold. Both systems can be used safely, provided the manufacturer instructions are followed and the irrigation system is effective.

LEVEL OF EVIDENCE

II (prospective randomized trial).

Dermal burn during hip arthroscopy

Radiofrequency devices are often used during arthroscopic surgery, most commonly of the shoulder and knee, and increasingly in hip arthroscopy. The most commonly described complication is elevation of joint temperature, leading to capsular shrinkage, chondrolysis, and nerve damage. A less commonly reported complication is that of dermal burns from the heated irrigation fluid. There are several case reports describing dermal burns after shoulder arthroscopy; however, to the authors' knowledge, there are none describing the complication in hip arthroscopy that is often performed by surgeons doing limited if any shoulder arthroscopy. The authors report this case to raise awareness that the use of radiofrequency devices can also lead to extra-articular complications because of the effect of elevated irrigant fluid temperatures on the patient's skin. Sufficiently high temperatures were generated inside the joint, causing a superficial second-degree burn from the outflow irrigant. In the course of instrument switching from sucker/shaver to radiofrequency wand, the outflow valve was inadvertently left open with no attached suction while the radiofrequency wand was in use. Most second-degree burns like the one reported require only conservative therapy with cool compresses to decrease the temperature of the wound. The authors did recommend bacitracin ointment to prevent superficial wound infection, however unlikely with no disruption of the skin. The authors continue to use radio-frequency devices in hip arthroscopy, but are vigilant to maintain dedicated suction at the outflow tubing throughout the procedure. Surgeons should take strict precautions to avoid this preventable complication and follow all manufacturer instructions on the use of such devices.

Effect of radiofrequency use on hip arthroscopy irrigation fluid temperature

PURPOSE

The purpose of this study was to determine operating parameters for joint fluid lavage using radiofrequency (RF) in maintaining intra-articular temperatures ≤50°C in the hip joint and to then quantify the influence of flow rate on maintaining safe intra-articular temperatures.

METHODS

Fiberoptic intra-articular thermometers at radial distance intervals of 1, 2, 5, and 10 mm, spanning cross-sectional areas of 3.14, 12.56, 78.5, and 314.1 mm(2), respectively, from the RF probe were used in 3 human hip cadaveric specimens at room temperature, with 9 trials per variable, using a 3-portal technique with a capsule release. Using a new Dyonics RF System continuously at the superior capsulolabral junction for 90 seconds, continuous temperatures were recorded at 50 mm Hg inflow and variable outflow intervals: no flow and 5, 15, and 30 seconds. Lavages were 1 second in duration on suction. Statistical comparison was through multivariate regression analysis and a logistic model.

RESULTS

Temperatures reached ≥50°C at 5-mm radial distance from the probe in all but the 5-second pulse lavage group. Elevated temperatures were reached within 1 to 2 seconds locally (1- to 2-mm radial distance) and at a radial distance of 5 mm in the 15-, 30-, and 0-second lavage groups. Logistic regression revealed a reduction in the odds that temperatures ≥50°C will occur as flow frequency increases every 30 (odds ratio = 0.68, P = .086); 15 (odds ratio = -1.22, P = .0067); and 5 (odds ratio = -4.26, P < .0001) seconds.

CONCLUSIONS

Increasing-interval pulsed irrigation is effective in maintaining intra-articular temperature profiles below 50°C during use of continuous RF ablation. Five-second-interval pulsed lavage is the longest flow interval identified during which fluid 5 mm radially from the RF device never reached temperatures >50°C.

CLINICAL RELEVANCE

Clinical guidelines for using the RF ablation include: meticulous technique, intermittent use, good inflow and outflow, and pulsed lavage at frequent intervals.

Thermal stress potentiates bupivacaine chondrotoxicity

PURPOSE

The primary objective of this study was to determine whether thermal stress potentiates the chondrotoxic effect of bupivacaine, resulting in decreased articular chondrocyte viability compared with exposure to bupivacaine alone.

METHODS

Bovine articular cartilage explants and cultured chondrocytes were treated with a range of thermal exposures (10 to 20 minutes at 37°C to 65°C) to create time/temperature viability curves and to determine threshold conditions for cell death. A second set of experiments was performed to determine whether subthreshold thermal stress potentiates bupivacaine toxicity. Explants were exposed to 37°C or 55°C for 10 or 20 minutes, and cultured chondrocytes were exposed to 37°C or 45°C for 10 or 20 minutes. Thirty minutes later, the explants and chondrocytes were treated with either 0.9% normal saline solution or 0.5% bupivacaine for 30 minutes. Chondrocyte viability was quantified 24 hours after treatment.

RESULTS

There was a temperature- and time-dependent decrease in chondrocyte viability above the thermo-toxicity threshold in both intact cartilage explants and cultured chondrocytes (55°C and 45°C, respectively; P < .05). Chondrocyte viability in cartilage explants was significantly lower after treatment with thermal stress for 10 or 20 minutes followed by bupivacaine for 30 minutes compared with treatment with bupivacaine at 37°C (bupivacaine and 55°C for 10 minutes, 0.09% ± 0%; bupivacaine and 55°C for 20 minutes, 0.08% ± 0%; bupivacaine and 37°C for 10 minutes, 37.4% ± 1.2% [P < .001]; and bupivacaine and 37°C for 20 minutes, 47.1% ± 0.8% [P < .001]). A similar trend was seen in cultured chondrocytes, although it was not statistically significant (P > .05).

CONCLUSIONS

Thermal stress potentiates the chondrotoxic effects of bupivacaine in intact cartilage, leading to decreased chondrocyte viability compared with exposure to bupivacaine alone.

CLINICAL RELEVANCE

Intra-articular injection of bupivacaine after arthroscopic procedures during which cartilage is exposed to elevated temperatures, such as with prolonged use of radiofrequency probes, may increase the risk of chondrocyte toxicity.

In vivo temperature measurement in the subacromial bursa during arthroscopic subacromial decompression

BACKGROUND

The purpose of the study was to evaluate whether use of a bi-polar radiofrequency (RF) ablation wand would cause excess heating, which may lead to collateral damage to the surrounding tissues during arthroscopic subacromial decompression. Cadaveric studies have shown that high temperatures can potentially be reached when using RF ablation wands in arthroscopic shoulder surgery. Only 1 other published study assesses these temperature rises in the clinical setting.

METHODS

Fifteen patients were recruited to participate in the study. A standard arthroscopic subacromial decompression was performed using continuous flow irrigation, with intermittent use of the RF ablation wand for soft tissue debridement. The temperature of the irrigation fluid within the subacromial bursa and the outflow fluid from the suction port of the wand were measured during the procedure using fiber-optic thermometers.

RESULTS

The mean peak temperature recorded in the subacromial bursa was 32.0°C (29.3-43.1°C), with a mean rise from baseline of 9.8°C. The mean peak temperature recorded from the outflow fluid from the wand was 71.6°C (65.6-77.6°C), with a mean rise from baseline of 49.4°C.

CONCLUSION

High temperatures were noted in the outflow fluid from the wand; however, this was not evident in the subacromial bursa itself. Use of room temperature inflow fluid, maintenance of flow through the bursa, and avoidance of prolonged uninterrupted use of the wand all appear to ensure that safe temperatures are maintained in the subacromial bursa not only in the laboratory but also in a clinical setting.

Thermal shrinkage for shoulder instability

Thermal capsular shrinkage was popular for the treatment of shoulder instability, despite a paucity of outcomes data in the literature defining the indications for this procedure or supporting its long-term efficacy. The purpose of this study was to perform a clinical evaluation of radiofrequency thermal capsular shrinkage for the treatment of shoulder instability, with a minimum 2-year follow-up. From 1999 to 2001, 101 consecutive patients with mild to moderate shoulder instability underwent shoulder stabilization surgery with thermal capsular shrinkage using a monopolar radiofrequency device. Follow-up included a subjective outcome questionnaire, discussion of pain, instability, and activity level. Mean follow-up was 3.3 years (range 2.0-4.7 years). The thermal capsular shrinkage procedure failed due to instability and/or pain in 31% of shoulders at a mean time of 39 months. In patients with unidirectional anterior instability and those with concomitant labral repair, the procedure proved effective. Patients with multidirectional instability had moderate success. In contrast, four of five patients with isolated posterior instability failed. Thermal capsular shrinkage has been advocated for the treatment of shoulder instability, particularly mild to moderate capsular laxity. The ease of the procedure makes it attractive. However, our retrospective review revealed an overall failure rate of 31% in 80 patients with 2-year minimum follow-up. This mid- to long-term cohort study adds to the literature lacking support for thermal capsulorrhaphy in general, particularly posterior instability.

ELECTRONIC SUPPLEMENTARY MATERIAL

The online version of this article (doi:10.1007/s11420-010-9187-7) contains supplementary material, which is available to authorized users.

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.

Pain pump use after shoulder arthroscopy as a cause of glenohumeral chondrolysis

Shoulder arthroscopy has become a routine outpatient surgery. Pain control is a limiting factor for patient discharge after surgery, and several modalities are used to provide continued analgesia postoperatively. Regional anesthetic blocks and shoulder pain pumps are common methods to provide short-term pain control. Shoulder pain pumps can be used either in the subacromial space or within the glenohumeral joint. Several clinical studies suggested--which was confirmed by a bovine and rabbit cartilage study--that there is significant chondrotoxicity from bupivacaine, a local anesthetic commonly used in pain pumps. Postarthroscopic glenohumeral chondrolysis is a noninfectious entity associated with factors including use of radiofrequency thermal instruments and intra-articular pain pumps that administer bupivacaine, but there have been no cases reported with subacromial pain pump placement. Treatment options are difficult in a young patient with postarthroscopic glenohumeral chondrolysis, and understanding the literature with regard to risk factors is paramount to counseling patients and preventing this devastating complication.

Effect of radiofrequency energy on glenohumeral fluid temperature during shoulder arthroscopy

BACKGROUND

Reports of glenohumeral chondrolysis following arthroscopy have raised concern about the deleterious effects that thermal devices may have on articular cartilage. The purpose of this study was to investigate the effects of flow and duration of treatment with a thermal device on temperatures within cadaveric glenohumeral joint specimens. It was hypothesized that the use of a thermal device during surgery increases the temperature of fluid within the joint to >45 degrees C, which has been shown to cause chondrocyte death.

METHODS

Temperature was measured at four locations within ten cadaver shoulder joints. Eight heating trials were performed on each cadaver shoulder to test three variables: the method of heating (continuous or intermittent), the fluid-pump flow rate (no flow, 50% flow, or 100% flow), and the location of the radiofrequency probe (the radiofrequency energy was either applied directly to anterior capsular tissue in a paintbrush pattern or held adjacent to the glenoid without tissue contact).

RESULTS

Temperatures of >45 degrees C occurred in every trial. The average maximum temperatures in all no-flow conditions were significantly higher than those in the trials with flow. Higher temperatures were measured by the anterior probe in all trials. When the heating had been applied adjacent to the glenoid, without tissue contact, the time needed to cool to a safe temperature was significantly longer in the no-flow states (average, 140.5 seconds) than it was in the 50% flow states (average, 12.5 seconds) or the 100% flow states (average, 8.5 seconds).

CONCLUSIONS

Use of a thermal probe during arthroscopy may cause joint fluid temperatures to reach levels high enough to cause chondrocyte death. Maintaining adequate fluid-pump flow rates may help to lower joint fluid temperatures and protect articular cartilage.

Glenohumeral chondrolysis after shoulder arthroscopy with thermal capsulorrhaphy

Glenohumeral chondrolysis is a rare but devastating complication that can occur after shoulder arthroscopy and thermal capsulorrhaphy. We retrospectively reviewed the medical records and imaging studies of 8 patients in whom glenohumeral chondrolysis developed after shoulder arthroscopy in which thermal energy was used. Of the 8 patients, 5 had previous thermal capsulorrhaphy for the diagnosis of instability. Two patients were diagnosed with instability with associated labral tears and underwent labral repair with thermal capsular shrinkage. One patient was diagnosed with a labral tear and underwent labral debridement with an extensive glenohumeral synovectomy via a thermal probe. No patients had evidence of chondral damage at their index arthroscopy, and none received postoperative pain pumps. In all patients, radiographic evidence of chondrolysis developed and repeat arthroscopy was performed to confirm the diagnosis. Open surgical stabilization has not been known to have this complication, and it is speculated that heating of the joint fluid at the time of arthroscopy from any source plays a role in cartilage death. Further studies are warranted to determine whether adequate outflow during shoulder arthroscopy where the fluid volume is relatively small will aid in avoiding complications associated with the use of heat sources.

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.