Abstract:Objective To design a type of intervertebral manual joint with grooving spring and analyse its mechnical analysis. Methods The joint consists of two parts: cage and internal nucleus. The cage with flat olive bore looks similar to the contour of the Ray-TFC, and has grooving spring on lateral sides. The internal nucleus also looks like flat olive in appearance but little smaller than the bore. After the insertion of the internal nucleus into the bore, the analogous motion of flexion, extension and lateral bending could be achieved through the stretching of the spring and the minute sliding of the nucleus. The intensity and fatigue tests then were carried out on MTS 858 machine. Results The results of intensity test proved that when the pressure reached to 130N, the cage still remained intact, and the spring was reduced 0.70mm . The fatigue test shew that there was no damage caused to the joint after 1×10 5 stress circulations in four days. Conclusion This type of manual joint may replace cervical disc well.