Similar growth plate morphology in stapling and tension band plating hemiepiphysiodesis: A porcine experimental histomorphometric study

Abstract

The tension band plating technique for hemiepiphysiodesis is new and advocated because it is believed to reduce the risk of premature closure of the growth plate compared to stapling. The benefit of the tension band plating technique has not yet been proven in experimental or randomized clinical studies. Ten weeks old domestic pigs in two randomized, paired studies were used. Right proximal tibia was randomized to medial epiphysiodesis by either stapling or tension band plating. Left side received the opposite treatment. Study A (n ¼ 10): 9 weeks treatment. Study B (n ¼ 8): implant removal after 9 weeks of treatment and 5 weeks of housing. Fractions of the chondrocyte layers were determined using quantitative histomorphometry. Mean heights of the growth plates were measured. No significant changes were observed between histomorphometric parameters in neither study A or B. Areas with disorganized cartilage tissue were abundant in 13/16 samples from study B and observed after both treatment with tension band plating and staples. Chondrocyte zone fractions did not differ between tension band plating and staple treatment in this randomized, paired animal study. The growth plate responded to release of hemiepiphysiodesis with abundant disorganized cartilage tissue in both groups. The histological response to hemiepiphysiodesis by tension band plating and staples appear to be similar. ß

Rebound growth after hemiepiphysiodesis

“…The choice was arbitrary, as the data available on the histological changes after hemiepiphysiodesis were limited. 18 Based on the literature, 19 we believed that three histological controls for each of the cut-off points would be sufficient for histological comparison.…”

“…A sham group was not used, as in previous studies of hemiepiphysiodesis no influence had been revealed. 18,20 The surgery comprised a medial proximal tibial hemiepiphysiodesis using a twohole titanium plate and screws (Normed, Tuttlingen, Germany). The device was left in place for three weeks and then removed.…”

Physeal histological morphology after thermal epiphysiodesis using radiofrequency ablation

“…Since its first description by Phemister in 1933, epiphysiodesis has become a common treatment for correction of deformities in growing children. Several techniques are currently used and all the non-reversible ones are used to obtain a permanent closure of the growth plate [3]. Thermal epiphysiodesis using radiofrequency ablation (RFA) has been reported as a successful treatment that can arrest growth in rabbits [4–6].…”

“…However, the effects of RFA epiphysiodesis in large species have not yet been described, to our knowledge. The histology of two reversible methods has been studied previously [3]. Micro-characteristics are important, sometimes crucial, to understanding disease and treatment.…”

“…1Growth plate zones, ×10. It is possible to identify the functional classification suggested by Delgado-Martos et al ( right ) [2], and the histological classification suggested by Marino ( left ) [3] …”