Injecting Chondrocytes Into The Physis From Physeal Distraction Of The Epiphysis

Me: The study seems to suggest that you can delay and prevent the closure of the physics (growth plate) if you can cause even the slightest of distraction in the epiphysis and inject even a little bit of chondrocyte the lengthening process can be extended leading to more height increase. This validates to a slight extent the idea of possibly putting a type of growth plate implant into the long limbs so that they can continue to or restart to lengthen again. However, the issue is that if you just use chondrocyte injections, the effect seems to only go towards the hypertrophic zone and the chondrocytes start to cluster which previous experiments have shown was not a good thing in the resting zone.

From the study “The purpose of this study was to determine if cultured chondrocytes could prevent premature closure of the physis after physeal distraction in a rabbit model.” The actual experiment was ” injection of cultured chondrocytes after epiphyseal distraction” . The conclusion was that “The zone of hypertrophic chondrocytes was enlarged. It appears that the injected cells differentiated into hypertrophic chondrocytes and delayed premature physeal closure. At 10 weeks after distraction of the physis, the width of the physis was restored to 75% of normal, but disordered chondrocyte growth with cell clustering was present in the cell-injected group.


J Orthop Res. 2006 Mar;24(3):355-65.

Chondrocyte injection in distraction epiphysiolysis (rabbit model).

Ahn JI, Erdin RA, Smith R, Canale ST, Hasty KA.

Source

Department of Orthopaedic Surgery, University of Tennessee Health Science Center-Campbell Clinic, 956 Court Avenue, Room A302, Memphis, Tennessee 38163, USA. jahn@utmem.edu

Abstract

The purpose of this study was to determine if cultured chondrocytes could prevent premature closure of the physis after physeal distraction in a rabbit model. Epiphyseal distraction at the proximal tibial epiphysis was performed in 24 immature rabbits. Chondrocytes were harvested from the iliac apophysis. The animals were divided into three groups: A, epiphyseal distraction alone; B, injection of phosphate buffered saline (PBS) after epiphyseal distraction; and C, injection of cultured chondrocytes after epiphyseal distraction. After epiphyseal separation was noted radiographically, each animal was evaluated at routine intervals. At 2 to 4 weeks, significant tibial lengthening as compared to the contralateral tibia was noted in all three groups. At 10 weeks, lengthening was apparent only in group C; in groups A and B, the operated tibia was shorter than the unoperated one. Histologic examination at 4 weeks revealed partial bony bridge formation with cell clustering in the fibrocartilaginous matrix in groups A and B. In group C, the matrix showed a typical hyaline aspect with cells organized in columns at the injection site. The zone of hypertrophic chondrocytes was enlarged. It appears that the injected cells differentiated into hypertrophic chondrocytes and delayed premature physeal closure. At 10 weeks after distraction of the physis, the width of the physis was restored to 75% of normal, but disordered chondrocyte growth with cell clustering was present in the cell-injected group.

Copyright 2005 Orthopaedic Research Society.

PMID: 16479568    [PubMed – indexed for MEDLINE]