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Does radiofrequency ablation (RFA) epiphysiodesis affect adjacent joint cartilage?

Shiguetomi-Medina JM, Rahbek O, Abood AA, Stødkilde-Jørgensen H, Ramírez Garcia-Luna JL, Møller-Madsen B - J Child Orthop (2016)

Bottom Line: We found no evidence of articular cartilage damage on the 40 8-min RFA procedures.The tibiae ablated for 16 min and 24 min showed intact joint cartilage.This study shows that RFA can be done safely in the growing physis of pigs, even with triple duration procedures.

View Article: PubMed Central - PubMed

Affiliation: Orthopaedic Research Laboratory, Danish Paediatric Orthopaedic Research, Aarhus University Hospital NBG, Aarhus University, Noerrebrogade 44 Building 1A, 8000, Aarhus C, Denmark. jmshigue@gmail.com.

ABSTRACT

Purpose: To test the hypothesis that epiphysiodesis made with radiofrequency ablation (RFA) is a safe procedure that disrupts the growth plate without damaging the adjacent joint articular cartilage.

Methods: RFA epiphysiodesis was done during 8 min in vivo in 40 growing pig tibia physis. In addition, three tibiae were ablated for 16 min and three more for 24 min. As a burned cartilage reference, six tibiae were ablated on the joint articular cartilage for 8 min. After the procedure, the animals were terminated and the tibiae were harvested. Magnetic resonance imaging (MRI) was done ex vivo to evaluate the joint articular cartilage in all samples. We used T1-weighted, T2-weighted, and water content sequences under a 1.5 T magnetic field.

Results: On the burned articular cartilage, intensity changes were observed at MRI. We found no evidence of articular cartilage damage on the 40 8-min RFA procedures. The tibiae ablated for 16 min and 24 min showed intact joint cartilage.

Conclusions: Epiphysiodesis using RFA is safe for the adjacent articular cartilage. This study shows that RFA can be done safely in the growing physis of pigs, even with triple duration procedures.

No MeSH data available.


Related in: MedlinePlus

Colored water content MRI, study A. The physeal ablation sites become evident (arrows)
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Fig6: Colored water content MRI, study A. The physeal ablation sites become evident (arrows)

Mentions: This nonsurvival study is based on a previously published protocol that results in growth arrest without giving the animal discomfort or complications during the follow-up [7]. Early changes caused by thermal damage to the articular cartilage are described by Meister et al. [9]. They report that thermal lesions of articular cartilage can be observed as “shrinkage” surrounded by edema. MR is accepted to analyze cartilage damage and it can detect early changes that result in degeneration [10]. After analysis using MR, we did not find any changes in the procedures where the physis was ablated. We could not identify shrinkage of the articular cartilage in the group that was ablated directly on the cartilage, but edema was evident and it was measured indirectly using MR T1 values [11]. In the present study, we chose a porcine model because the bone biology resembles humans and the distance between the physis and the articular cartilage is closely equal to humans [12]. Subjective evaluation of MRI both in T1-weighted and T2-weighted images can suggest tissue changes. In colored water content images (Fig. 6), these changes are easier to identify. However, an objective analysis is more accurate and can be obtained from T1 mapping. This allows the quantification of damage and usage of reference parameters. The water content allows it to be known if the cells are compromised or they suffered damage. Damaged cell membranes lead to cell death. Thermal damage affects mainly membranes. Such changes directly affect the water content immediately [3]. Damaged membranes lead to edema, which causes an influx of calcium. This phenomenon can be observed even in temperatures of 50 °C, which would not cause cellular death but would suppress the ability of chondrocytes to remodel, leading to permanent damage [13].Fig. 6


Does radiofrequency ablation (RFA) epiphysiodesis affect adjacent joint cartilage?

Shiguetomi-Medina JM, Rahbek O, Abood AA, Stødkilde-Jørgensen H, Ramírez Garcia-Luna JL, Møller-Madsen B - J Child Orthop (2016)

Colored water content MRI, study A. The physeal ablation sites become evident (arrows)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4940242&req=5

Fig6: Colored water content MRI, study A. The physeal ablation sites become evident (arrows)
Mentions: This nonsurvival study is based on a previously published protocol that results in growth arrest without giving the animal discomfort or complications during the follow-up [7]. Early changes caused by thermal damage to the articular cartilage are described by Meister et al. [9]. They report that thermal lesions of articular cartilage can be observed as “shrinkage” surrounded by edema. MR is accepted to analyze cartilage damage and it can detect early changes that result in degeneration [10]. After analysis using MR, we did not find any changes in the procedures where the physis was ablated. We could not identify shrinkage of the articular cartilage in the group that was ablated directly on the cartilage, but edema was evident and it was measured indirectly using MR T1 values [11]. In the present study, we chose a porcine model because the bone biology resembles humans and the distance between the physis and the articular cartilage is closely equal to humans [12]. Subjective evaluation of MRI both in T1-weighted and T2-weighted images can suggest tissue changes. In colored water content images (Fig. 6), these changes are easier to identify. However, an objective analysis is more accurate and can be obtained from T1 mapping. This allows the quantification of damage and usage of reference parameters. The water content allows it to be known if the cells are compromised or they suffered damage. Damaged cell membranes lead to cell death. Thermal damage affects mainly membranes. Such changes directly affect the water content immediately [3]. Damaged membranes lead to edema, which causes an influx of calcium. This phenomenon can be observed even in temperatures of 50 °C, which would not cause cellular death but would suppress the ability of chondrocytes to remodel, leading to permanent damage [13].Fig. 6

Bottom Line: We found no evidence of articular cartilage damage on the 40 8-min RFA procedures.The tibiae ablated for 16 min and 24 min showed intact joint cartilage.This study shows that RFA can be done safely in the growing physis of pigs, even with triple duration procedures.

View Article: PubMed Central - PubMed

Affiliation: Orthopaedic Research Laboratory, Danish Paediatric Orthopaedic Research, Aarhus University Hospital NBG, Aarhus University, Noerrebrogade 44 Building 1A, 8000, Aarhus C, Denmark. jmshigue@gmail.com.

ABSTRACT

Purpose: To test the hypothesis that epiphysiodesis made with radiofrequency ablation (RFA) is a safe procedure that disrupts the growth plate without damaging the adjacent joint articular cartilage.

Methods: RFA epiphysiodesis was done during 8 min in vivo in 40 growing pig tibia physis. In addition, three tibiae were ablated for 16 min and three more for 24 min. As a burned cartilage reference, six tibiae were ablated on the joint articular cartilage for 8 min. After the procedure, the animals were terminated and the tibiae were harvested. Magnetic resonance imaging (MRI) was done ex vivo to evaluate the joint articular cartilage in all samples. We used T1-weighted, T2-weighted, and water content sequences under a 1.5 T magnetic field.

Results: On the burned articular cartilage, intensity changes were observed at MRI. We found no evidence of articular cartilage damage on the 40 8-min RFA procedures. The tibiae ablated for 16 min and 24 min showed intact joint cartilage.

Conclusions: Epiphysiodesis using RFA is safe for the adjacent articular cartilage. This study shows that RFA can be done safely in the growing physis of pigs, even with triple duration procedures.

No MeSH data available.


Related in: MedlinePlus