This trial is investigating whether donated bone marrow stem cells can aid recovery following surgery for avascular necrosis of the femoral head. This study is being conducted at the Hospital Universitari Vall d'Hebron in Barcelona in conjunction with the Spanish Blood and Tissue Bank (Banc de Sang i Teixits). The trial expects to recruit 24 participants with avascular necrosis of the femoral head between July 2012 and December 2014. The subjects will be randomly assigned to a control group which will receive standard treatment, or an experimental group that will have a transplant of a proprietary product that is an donated bone matrix impregnated with donated bone marrow derived stem cells (XCEL-MT-OSTEO-ALPHA). Participants will be monitored for complications and for changes in bone growth and pain levels.