Load sharing interbody fusion device

A method of spacing apart opposing vertebral end plates by:

• inserting a spacer between opposing vertebral end plates;
• and
• controlling reduction in height of the spacer during a healing process of a reconstructed vertebral space defined by the end plates.

An interbody fusion device comprising:

• a first portion including a first side having a first end plate surface for engaging an end plate of a first vertebral body and a second opposite side having male portion extending therefrom, said male portion including an end surface;
• and
• a second portion including a second end plate surface for engaging an opposing end plate of a second vertebral body, said second portion including a cavity defined by a wall portion surrounding a floor portion for slidingly receiving said male portion therein and entrapping a bioresorbable material between said end surface and said floor portion.

An interbody fusion device comprising:

• piston means for entrapping a bioresorbable material therein and having a predetermined height which reduces as the bioresorbable material resorbs;
• and
• vertebral end plate gripping means for fixedly engaging opposing vertebral end plates when said device is disposed therebetween.

An interbody fusion device comprising:

• a male member including a first end plate surface for engaging an end plate of a first vertebral body and a lower surface;
• and
• a female member including a second end plate surface for engaging an opposing end plate for a second vertebral body, said female member including a cavity having wall portions surrounding a floor portion for slidingly receiving said lower surface therein and entrapping a biosorbable material between said lower surface and said floor portion.