Tension-Free Weight-Bearing Model of Steroid-Induced Osteonecrosis of Femoral Head in Rats

Summary

The protocol shows building a simple and cost-effective rat weight-bearing training model for steroid-induced osteonecrosis of the femoral head using elastic therapeutic tape.

Abstract

Unlike humans, rats are animals that walk on all fours, while humans are bipedal animals that stand, and the hips are subjected to tremendous pressure when walking and standing. In rat steroid-induced femoral head necrosis models, the biomechanical characteristics of the human hip under higher pressure often need to be simulated. Some scholars try to emulate the state of human hip pressure by making rats bear a certain weight, but fixing the weight-bearing object on the rat is tough. Rats can easily break free of immobilization, and sticking the weight on the rats with adhesive tape will cause the rats to suffocate or die from intestinal obstruction. Our research group used elastic therapeutic tape to perform tension-free immobilization of weight-bearing objects in rats so that the rats could breathe freely and not break away from the immobilization under weight-bearing conditions. Compared to the usual steroid-induced femoral head necrosis rat model, we found that this weight-bearing intervention can aggravate the progression of femoral head necrosis in rats.

Introduction

The administration of glucocorticoids is the most common risk factor for non-traumatic osteonecrosis of the femoral head (ONFH)¹. Numerous pieces of evidence suggest that, in addition to glucocorticoids, the pressure load on the hip joint in patients is also associated with the occurrence of ONFH. Factors such as body weight and physical labor intensity are recognized as risk factors for ONFH². Multiple clinical studies have demonstrated a close relationship between hip joint loading conditions and the timing and incidence of joint replacement^3,4,

Protocol

The protocol adheres to the ethical guidelines set by the Institutional Animal Care and Use Committee (IACUC) at Beijing University of Chinese Medicine, Protocol number BUCM-4-2022062001-2109. The protocol uses Sprague Dawley (SD) rats (SCXK(Jing)2019-0008), aged 8-10 weeks and weighing 200 g-250 g.

1. Adaptation training

1. Albino rats generally have a visual range of less than 60 cm¹⁵. During the modeling process, place the rats in opaque cag.......

Discussion

Currently, various animals, such as rabbits²⁵, rats²⁶, mice²⁷, pigs²⁸, broilers²⁹, ostriches⁸, and emus³⁰ can be used to establish models of femoral head necrosis. Among them, rats, mice, and rabbits are the most commonly used species. The rat, as a model for femoral head necrosis, offers numerous advantages. Rats are easy to feed and breed, grow rapidly, .......

Materials

Name	Company	Catalog Number	Comments
15ml centrifuge tube	Corning,USA	430791
5mm stainless steel bead	Gelisen,China	5mm
Acetic acid	Merck KGaA, Germany	64-19-7
Anhydrous alcohol	Merck KGaA, Germany	64-17-5
clay	Mincai stationery,China	102
Coverslip	Servicebio,China	WMWD-1818
Flat pressure bottle 10ml	BEHNCKE,China	MD10ml
Formic acid	Macklin Biochemical ,China	64-18-6
HE staining kit	Solarbio,China	G1120
HistoCore AUTOCUT	Leica, Germany	149AUTO00C1
Kinesio tape (elastic therapeutic tape)	Fuluo medicine,China	CL1819
Lipopolysaccharide	Solarbio,China	L8880
Lipopolysaccharides (LPS)	Selleck,USA	S7850
Manual carbon dioxide euthanasia box	Yuyan,China	LC-500-S1
Methylprednisolone sodium succinate,MPS	AbMole,China	M25573
MicroCT	Hiscan,China	Hiscan VM Pro
Neutral resin	Beijing Zhongshan Golden Bridge Biotechnology l ,China	ZLI-9555
Paraffin	Servicebio,China	WGHB-319213129
Paraformaldehyde	Servicebio,China	G1101-500ML
Potassium chloride	Macklin Biochemical ,China	7447-40-7
Slide	Servicebio,China	WG6012
Treadmill for Rats and  mice	Litc Life Science,USA	801
Xylene	Macklin Biochemical ,China	1330-20-7