Original Research

Radiofrequency Stimulation for Potential Healing of Meniscal Injuries in the Avascular Zone

Am J Orthop. 2014 December;43(12):E292-E298

References

1. Fauno P, Nielsen AB. Arthroscopic partial meniscectomy: a long-term follow-up. Arthroscopy. 1992;8(3):345-349.

2. Lynch MA, Henning CE, Glick KR, Jr. Knee joint surface changes. Long-term follow-up meniscus tear treatment in stable anterior cruciate ligament reconstructions. Clin Orthop. 1983;172:148-153.

3. Roos H, Lauren M, Adalberth T, Roos EM, Jonsson K, Lohmander LS. Knee osteoarthritis after meniscectomy: prevalence of radiographic changes after twenty-one years, compared with matched controls. Arthritis Rheum. 1998;41(4):687-693.

4. Hennerbichler A, Moutos FT, Hennerbichler D, Weinberg JB, Guilak F. Repair response of the inner and outer regions of the porcine meniscus in vitro. Am J Sports Med. 2007;35(5):754‑762.

5. Gershuni DH, Hargens AR, Danzig LA. Regional nutrition and cellularity of the meniscus. Implications for tear and repair. Sports Med. 1988;5(5):322-327.

6. Gershuni DH, Skyhar MJ, Danzig LA, Camp J, Hargens AR, Akeson WH. Experimental models to promote healing of tears in the avascular segment of canine knee menisci. J Bone Joint Surg Am. 1989;71(9):1363-1370.

7. Papachristou G, Efstathopoulos N, Plessas S, Levidiotis C, Chronopoulos E, Sourlas J. Isolated meniscal repair in the avascular area. Acta Orthop Belg. 2003;69(4):341-345.

8. Fox JM, Rintz KG, Ferkel RD. Trephination of incomplete meniscal tears. Arthroscopy. 1993;9(4):451-455.

9. Zhang Z, Arnold JA, Williams T, McCann B. Repairs by trephination and suturing of longitudinal injuries in the avascular area of the meniscus in goats. Am J Sports Med. 1995;23(1):35-41.

10. Zhang ZN, Tu KY, Xu YK, Zhang WM, Liu ZT, Ou SH. Treatment of longitudinal injuries in avascular area of meniscus in dogs by trephination. Arthroscopy. 1988;4(3):151-159.

11. Ochi M, Uchio Y, Okuda K, Shu N, Yamaguchi H, Sakai Y. Expression of cytokines after meniscal rasping to promote meniscal healing. Arthroscopy. 2001;17(7):724-731.

12. Okuda K, Ochi M, Shu N, Uchio Y. Meniscal rasping for repair of meniscal tear in the avascular zone. Arthroscopy. 1999;15(3):281-286.

13. Uchio Y, Ochi M, Adachi N, Kawasaki K, Iwasa J. Results of rasping of meniscal tears with and without anterior cruciate ligament injury as evaluated by second-look arthroscopy. Arthroscopy. 2003;19(5):463-469.

14. Tasto JP, Cummings J, Medlock V, Harwood F, Hardesty R, Amiel D. The tendon treatment center: new horizons in the treatment of tendinosis. Arthroscopy. 2003;19(suppl 1):213-223.

15. Tasto JP. The role of radiofrequency-based devices in shaping the future of orthopedic surgery. Orthopedics. 2006;29(10):874-875.

16. Tasto JP, Cummings J, Medlock V, Hardesty R, Amiel D. Microtenotomy using a radiofrequency probe to treat lateral epicondylitis. Arthroscopy. 2005;21(7):851-860.

17. Higuchi H, Kimura M, Kobayashi A, Hatayama K, Takagishi K. A novel treatment of hypermobile lateral meniscus with monopolar radiofrequency energy. Arthroscopy 2004;20 (suppl 2):1-5.

18. Tonna EA, Cronkite EP. The periosteum. Autoradiographic studies on cellular proliferation and transformation utilizing tritiated thymidine. Clin Orthop. 1963;30:218-233.

19. Madewell BR. Serum thymidine kinase activity: an alternative to histologic markers of cellular proliferation in canine lymphoma. J Vet Intern Med. 2004;18(5):595-596.

20. Mujoomdar M, Bennett A, Hoskin D, Blay J. Adenosine stimulation of proliferation of breast carcinoma cell lines: evaluation of the [3H]thymidine assay system and modulatory effects of the cellular microenvironment in vitro. J Cell Physiol. 2004;201(3):429-438.

21. Vander Borght T, Labar D, Pauwels S, Lambotte L. Production of [2-11C]thymidine for quantification of cellular proliferation with PET. Int J Rad Appl Instrum A. 1991;42(1):103-104.

22. Spindler KP, Mayes CE, Miller RR, Imro AK, Davidson JM. Regional mitogenic response of the meniscus to platelet-derived growth factor (PDGF-AB). J Orthop Res. 1995;13(2):201-207.

23. Thomopoulos S, Zaegel M, Das R, et al. PDGF-BB released in tendon repair using a novel delivery system promotes cell proliferation and collagen remodeling. J Orthop Res. 2007;25(10):1358-1368.

24. Pennock AT, Robertson CM, Emmerson BC, Harwood FL, Amiel D. Role of apoptotic and matrix-degrading genes in articular cartilage and meniscus of mature and aged rabbits during development of osteoarthritis. Arthritis Rheum. 2007;56(5):1529-1536.

25. Allen RT, Tasto JP, Cummings J, Robertson CM, Amiel D. Meniscal debridement with an arthroscopic radiofrequency wand versus an arthroscopic shaver: comparative effects on menisci and underlying articular cartilage. Arthroscopy. 2006;22(4):385-393.

26. Figueroa D, Calvo R, Vaisman A, et al. Bipolar radiofrequency in the human meniscus. Comparative study between patients younger and older than 40 years of age. Knee. 2007;14(5):357-360.

27. Friedman M, LoSavio P, Ibrahim H, Ramakrishnan V. Radiofrequency tonsil reduction: safety, morbidity, and efficacy. Laryngoscope. 2003;113(5):882-887.

28. Hall DJ, Littlefield PD, Birkmire-Peters DP, Holtel MR. Radiofrequency ablation versus electrocautery in tonsillectomy. Otolaryngol Head Neck Surg. 2004;130(3):300-305.

29. Kaplan H, Gat A. Clinical and histopathological results following TriPollar radiofrequency skin treatments. J Cosmet Laser Ther. 2009;11(2):78-84.

30. Mancini PF. Coblation: a new technology and technique for skin resurfacing and other aesthetic surgical procedures. Aesthetic Plast Surg. 2001;2595):372-377.

31. Penka I, Kaplan Z, Sefr R, Sirotek L, Eber Z, Ondrák M. Use of radiofrequency ablation in the treatment of malignant liver lesions. Hepatogastroenterology. 2008;55(82-83):562-567.

32. Tasto JP, Ash SA. Current uses of radiofrequency in arthroscopic knee surgery. Am J Knee Surg. 1999;12(3):186-191.

33. Amiel D, Ball ST, Tasto JP. Chondrocyte viability and metabolic activity after treatment of bovine articular cartilage with bipolar radiofrequency: an in vitro study. Arthroscopy. 2004;20(5):503-510.

34. Barry KJ, Kaplan J, Connolly RJ, et al. The effect of radiofrequency-generated thermal energy on the mechanical and histologic characteristics of the arterial wall in vivo: implications for radiofrequency angioplasty. Am Heart J. 1989;117(2):332-341.

35. Hoch DH, Grodzinsky AJ, Koob TJ, Albert ML, Eyre DR. Early changes in material properties of rabbit articular cartilage after meniscectomy. J Orthop Res. 1983;1(1):4-12.

36. Thompson AM, Stockwell RA. An ultrastructural study of the marginal transitional zone in the rabbit knee joint. J Anat. 1983;136(Pt 4):701-713.

Adverse Outcomes

There were no surgical complications. During the histologic evaluation, there were no incidences of fibrochondrocyte cell death or damage from the application of RF treatment.

Discussion

RF treatments have been used for many years in various medical and surgical applications. Presently, the most common implementation of RF is for cutting and coagulating tissue during surgery. More recently, however, several publications have shown that when used properly and safely, RF can be an effective surgical adjunct for tendinosis recalcitrant to conservative therapy.^15-17,25-32

Many have suggested that RF coblation is successful in these clinical scenarios because of its ability to promote an increased angiogenic and fibroblastic response in hypovascular tissue.^29,33,34

This body of literature led to the evaluation of RF coblation in treating meniscal tears in the avascular zone. Studies have shown poor success of meniscus repairs done in the avascular zone; however, our data demonstrate that supplementing suture repair with RF treatment may improve the acute-phase healing response. Although the control and suture-repair groups showed no signs of healing, the suture-repair-combined-with-RF-treatment group had 2 specimens in which complete gross and histologic healing occurred. In addition, 19 (58%) specimens in the RF group showed gross or histologic signs of healing.

Biochemically, ³H-thymidine incorporation was examined to assess cellular proliferation. Mitogenic (IGF, bFGF) and angiogenic (VEGF, αV) growth factors were measured as markers of an increased healing response. Compared with noninjured meniscal tissue, ³H-thymidine incorporation was significantly increased in both the suture and suture-combined-with-RF-treatment groups at 9 and 28 days after surgery. Between the suture and suture-RF groups, RF treatment led to a 40% greater increase in ³H-thymidine incorporation suggesting greater cellular proliferation in the immediate postoperative period. With respect to mitogenic and angiogenic factors, IGF, bFGF, VEGF, and αV were only significantly increased when RF was combined with suture repair. All 4 factors are important regulators of vasculogenesis, angiogenesis, wound healing, bone remodeling, and neurogenesis. The suture repair–only group showed no upregulation of these factors compared with uninjured controls.

Our study has several strengths. Using an animal model with menisci grossly similar to that of humans, we performed a controlled study comparing 2 treatment options, suture repair only and suture repair combined with RF treatment.^35,36The animal model also enabled second-look examinations at designated intervals. We analyzed the effect of RF treatment on concrete measures, such as gross, histologic, and biochemical healing. In particular, the biochemical analysis may indicate that RF treatment can increase the proliferative, mitogenic, and angiogenic capabilities of surrounding progenitor cells. This was evidenced by the statistically significant increase we saw in IGF-1, bFGF, VEGF, and αV at 9 and 28 days compared with controls.

Meniscal tears in the avascular zone represent a significant treatment dilemma for the physiologically young patient population. While partial meniscectomy provides excellent short-term relief, the long-term outcome of this intervention is degenerative joint disease. Meniscal repair in the central two-thirds of the meniscus has shown poor results. Our study presents data that show supplementing suture repair of avascular meniscal tears with RF can lead to increased gross, histologic, and biochemical healing in the New Zealand white rabbit. While these results are encouraging, studies with longer follow-up and specimens that represent the human menisci are necessary to determine whether these preliminary results would translate to human meniscal tears in the avascular zone.

Weaknesses of our study include the use of an animal model and the location of the tear created in the menisci. While using an animal model had many strengths, the results of our study are probably not strong enough to immediately extrapolate the use of RF in human meniscal repairs. However, the data we obtained are very encouraging and perhaps suggest that RF warrants human trials. Our open surgical technique made it difficult to create and repair a tear on the posterior horn of the medical meniscus without completely dislocating the knee anteriorly. As a result, the knees were subluxed anteriorly, and the meniscal tears and repairs were performed more anteriorly. The more anterior aspects of the menisci do not undergo the same rotational and axial loads as the posterior horn, and it is unclear whether this difference would contribute to the results we obtained from RF treatment. In addition, the tears were surgically created and the repair was done during the same procedure. Patients do not present in this manner, and this further underscores the need for a clinical trial to determine the effectiveness of this treatment option in humans.

Conclusion

RF-based supplementation of meniscal repairs in the avascular zone showed acute signs of biochemical healing in 58% of New Zealand white rabbit specimens. In addition, gross and histologic evaluations showed an increase in healing compared with controls. Two specimens treated with RF in combination with suture repair had complete healing. These results illustrate the effectiveness of RF in stimulating a healing response in hypovascular tissue. Clinical trials are necessary to determine the effectiveness of this treatment in humans.