The Acute Effect of Bipolar Radiofrequency Energy Thermal Chondroplasty on Intrinsic Biomechanical Properties and Thickness of Chondromalacic Human Articular Cartilage

2012 ◽  
Vol 134 (8) ◽  
Author(s):  
Nicholas Dutcheshen ◽  
Tristan Maerz ◽  
Patrick Rabban ◽  
Roger C. Haut ◽  
Keith D. Button ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Time Constant ◽  
Peak Force ◽  
Radiofrequency Energy ◽  
Human Articular Cartilage ◽  
Radio Frequency Energy ◽  
Grade Ii ◽  
Matrix Modulus ◽  
Tissue Permeability ◽  
Thermal Chondroplasty

Radio frequency energy (RFE) thermal chondroplasty has been a widely-utilized method of cartilage debridement in the past. Little is known regarding its effect on tissue mechanics. This study investigated the acute biomechanical effects of bipolar RFE treatment on human chondromalacic cartilage. Articular cartilage specimens were extracted (n = 50) from femoral condyle samples of patients undergoing total knee arthroplasty. Chondromalacia was graded with the Outerbridge classification system. Tissue thicknesses were measured using a needle punch test. Specimens underwent pretreatment load-relaxation testing using a spherical indenter. Bipolar RFE treatment was applied for 45 s and the indentation protocol was repeated. Structural properties were derived from the force-time data. Mechanical properties were derived using a fibril-reinforced biphasic cartilage model. Statistics were performed using repeated measures ANOVA. Cartilage thickness decreased after RFE treatment from a mean of 2.61 mm to 2.20 mm in Grade II, II-III, and III specimens (P < 0.001 each). Peak force increased after RFE treatment from a mean of 3.91 N to 4.91 N in Grade II and III specimens (P = 0.002 and P = 0.003, respectively). Equilibrium force increased after RFE treatment from a mean of 0.236 N to 0.457 N (P < 0.001 each grade). Time constant decreased after RFE treatment from a mean of 0.392 to 0.234 (P < 0.001 for each grade). Matrix modulus increased in all specimens following RFE treatment from a mean 259.12 kPa to 523.36 kPa (P < 0.001 each grade). Collagen fibril modulus decreased in Grade II and II-III specimens from 60.50 MPa to 42.04 MPa (P < 0.001 and P = 0.005, respectively). Tissue permeability decreased in Grade II and III specimens from 2.04 *10−15 m4/Ns to 0.91 *10−15 m4/Ns (P < 0.001 and P = 0.009, respectively). RFE treatment decreased thickness, time constant, fibril modulus, permeability, but increased peak force, equilibrium force, and matrix modulus. While resistance to shear and tension could be compromised due to removal of the superficial layer and decreased fibril modulus, RFE treatment increases matrix modulus and decreases tissue permeability which may restore the load- bearing capacity of the cartilage.

Effects of Radiofrequency Energy on Human Articular Cartilage

2005 ◽  
Vol 33 (7) ◽  
pp. 1035-1039 ◽  
Author(s):  
Sean Caffey ◽  
Edward McPherson ◽  
Brian Moore ◽  
Thomas Hedman ◽  
C. Thomas Vangsness
Keyword(s):  
Cell Death ◽  
Articular Cartilage ◽  
Dead Cell ◽  
Radiofrequency Energy ◽  
Human Articular Cartilage ◽  
Human Cartilage ◽  
Cellular Death ◽  
Significant Difference ◽  
Grade Ii ◽  
Grade Iii

Background Previous radiofrequency work has not rigidly controlled energy application to the articular cartilage, giving uncertain results published to date. Hypothesis At minimal settings, radiofrequency probes cause cell death in measurable areas when applied to human articular cartilage. Study Design Controlled laboratory study. Methods Simulating operating room conditions, 5 commercially available radiofrequency probes were attached to a customized jig to standardize a minimal contact pressure of each probe tip to 2.0 g. Keeping all variables the same, probes were placed on specific points of fresh grade II human cartilage with treatment times of 1 and 3 seconds at the manufacturer's recommended settings. Grade III cartilage was also tested with a treatment time of 3 seconds, and grade II cartilage was studied with the probe held 1 mm off the cartilage surface. Cartilage was blindly analyzed by confocal microscopy using a live/dead cell viability assay to determine the extent of cell death. Results Radiofrequency probes produced significant cellular death in the form of a half-circle into the cartilage to variable depths. For treatment times of 1 and 3 seconds, cell death measurements ranged from 404 to 539 μm and 1034 to 1283 μm, respectively. One probe failed to show any effect, with minimal evidence of cell death or cartilage smoothing. When probes were kept a 1.0-mm distance above the cartilage, no cell death or cartilage smoothing was noted. Radiofrequency treatment of grade III cartilage penetrated to the subchondral bone. There was no statistically significant difference between the damage caused by monopolar and bipolar probes when tested under these rigidly controlled conditions. Conclusion These results showed significant cellular death at these minimal conditions to the underlying chondrocytes with radiofrequency probes. Surgeons using this technology need to be aware of the power and dangerous potential these probes can have on articular cartilage.

Mechanical and Biochemical Effect of Monopolar Radiofrequency Energy on Human Articular Cartilage

2006 ◽  
Vol 34 (8) ◽  
pp. 1322-1327 ◽  
Author(s):  
Ko Yasura ◽  
Yasuaki Nakagawa ◽  
Masahiko Kobayashi ◽  
Hiroshi Kuroki ◽  
Takashi Nakamura
Keyword(s):  
Articular Cartilage ◽  
Radiofrequency Energy ◽  
Human Articular Cartilage ◽  
Biochemical Effect

Effect of bipolar radiofrequency energy on human articular cartilage

2001 ◽  
Vol 17 (2) ◽  
pp. 117-123 ◽  
Author(s):  
Yan Lu ◽  
Ryland B. Edwards ◽  
Vicki L. Kalscheur ◽  
Shane Nho ◽  
Brian J. Cole ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Radiofrequency Energy ◽  
Human Articular Cartilage ◽  
Bipolar Radiofrequency

Recovery of Chondrocyte Metabolic Activity after Thermal Exposure

2003 ◽  
Vol 31 (3) ◽  
pp. 392-398 ◽  
Author(s):  
Lee D. Kaplan ◽  
Constance R. Chu ◽  
James P. Bradley ◽  
Freddie H. Fu ◽  
Rebecca K. Studer
Keyword(s):  
Thermal Stress ◽  
Articular Cartilage ◽  
Metabolic Activity ◽  
Clinical Relevance ◽  
Thermal Exposure ◽  
Radiofrequency Energy ◽  
Human Cartilage ◽  
Energy Devices ◽  
Increased Sensitivity ◽  
Thermal Chondroplasty

Background The relationship between temperature elevation and thermal exposure time during thermal chondroplasty has implications for cell viability and subsequent articular cartilage function. Purpose To characterize cartilage metabolic changes after exposure to thermal stress and to determine whether changes seen acutely are reversible. Study Design Controlled laboratory study. Methods Human cartilage was exposed to a 45°, 50°, or 55°C bath for up to 3 minutes. Untreated control specimens were analyzed with each group. Viability and metabolic capability of treated and untreated specimens were evaluated immediately or 1 week after thermal stress by using methylthiotetrazole conversion, 3H-serine incorporation into protein, and 35S-sulfate incorporation into newly synthesized proteoglycan. Results Nonarthritic and arthritic articular cartilage metabolic activity declined with increasing thermal exposure. Articular cartilage displayed a recovery from thermal stress after exposure to the 50°C but not the 55°C bath. Arthritic cartilage displayed increased sensitivity with higher temperatures. Conclusions Understanding of the increased sensitivity to thermal stress of arthritic articular cartilage may be helpful in thermally based treatments. Clinical Relevance Further correlation with the temperatures attained during thermal chondroplasty will be necessary to confirm the clinical relevance of these in vitro observations to the use of radiofrequency energy devices to treat partial-thickness chondral lesions.

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