<qa>  What is the purpose of the study?The purpose of the study is to prospectively measure pain, function, and patient satisfaction in 70 consecutive patients treated by lumbar fusion using the Triad allograft. Results of the Triad allograft will be compared to those of other anterior lumbar interbody fusion ALIF, transforaminal lumbar interbody fusion TLIF, and posterior lumbar interbody fusion PLIF surgeries. Patient participation is based on the physician determination that the patient requires one of these surgeries. Participants will be evaluated pre-operatively and post-operatively at 3, 6, 12,and 24 month intervals. Clinic procedures will be related to standard of care except for the completion of several study questionnaires: 