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

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 = 10): 9 weeks treatment. Study B (n = 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.