Radiofrequency use on articular cartilage lesions

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.

Strategies for articular cartilage lesion repair and functional restoration

Injury of articular cartilage due to trauma or pathological conditions is the major cause of disability worldwide, especially in North America. The increasing number of patients suffering from joint-related conditions leads to a concomitant increase in the economic burden. In this review article, we focus on strategies to repair and replace knee joint cartilage, since knee-associated disabilities are more prevalent than any other joint. Because of inadequacies associated with widely used approaches, the orthopedic community has an increasing tendency to develop biological strategies, which include transplantation of autologous (i.e., mosaicplasty) or allogeneic osteochondral grafts, autologous chondrocytes (autologous chondrocyte transplantation), or tissue-engineered cartilage substitutes. Tissue-engineered cartilage constructs represent a highly promising treatment option for knee injury as they mimic the biomechanical environment of the native cartilage and have superior integration capabilities. Currently, a wide range of tissue-engineering-based strategies are established and investigated clinically as an alternative to the routinely used techniques (i.e., knee replacement and autologous chondrocyte transplantation). Tissue-engineering-based strategies include implantation of autologous chondrocytes in combination with collagen I, collagen I/III (matrix-induced autologous chondrocyte implantation), HYAFF 11 (Hyalograft C), and fibrin glue (Tissucol) or implantation of minced cartilage in combination with copolymers of polyglycolic acid along with polycaprolactone (cartilage autograft implantation system), and fibrin glue (DeNovo NT graft). Tissue-engineered cartilage replacements show better clinical outcomes in the short term, and with advances that have been made in orthopedics they can be introduced arthroscopically in a minimally invasive fashion. Thus, the future is bright for this innovative approach to restore function.

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.

Severe chondrolysis after shoulder arthroscopy: a case series

HYPOTHESIS

Chondrolysis has been observed after shoulder arthroscopy and results in severe glenohumeral complications.

MATERIALS AND METHODS

Twenty three cases of post-arthroscopic glenohumeral chondrolysis, occurring between 2005-2006, are reported following a variety of arthroscopic shoulder procedures. Presenting complaints, signs and symptoms, associated operative findings, and potential etiological factors are reviewed. Management options are summarized.

RESULTS

Of the 23 cases of chondrolysis identified in our practice over a two year period, 14 occurred in patients following labral repair using a bioabsorbable device. Seventeen of the 23 patients used a high volume intra-articular pain pump for 48 hours after surgery. Seven of the 23 cases had documented use of a thermal probe. Four cases occurred in shoulders with no reported use of fixation anchors, pain pumps, or thermal probes. All cases had at least a 20 cc intra-articular bolus injection of 0.25% bupivicaine with epinephrine.

DISCUSSION

This case series identifies several common factors that could be responsible for post-arthroscopic glenohumeral chondrolysis. No single mechanism can be implicated based on the results of this study. Although strong concerns are raised over the use of intra-articular local anesthetics, glenohumeral chondrolysis appears to be an unfortunate convergence of multiple factors that may initiate rapid dissolution of articular cartilage and degenerative changes.

CONCLUSION

Chondrolysis is a devastating complication of arthroscopic shoulder surgery that can result in long-term disabling consequences. Further research is required to specifically identify causative factors. Until this is a available, we strongly advise against the use of large doses of intra-articular placement of local anesthetics.