Comparison of Iliac Crest Marrow vs. Proximal Tibia Avitus® Bone Graft

Inclusion Criteria:

* Patient must be 18 years of age or older.
* Patient must be able and willing to sign the IRB approved informed consent.
* Patient must consent to preoperative knee and pelvis radiographs to confirm no issue at harvest location.
* Patient has indication for autograft bone harvest (undergoing any ankle or hindfoot fusion, complex mid and forefoot fusions requiring graft supplementation, treatment of fuse and fracture nonunions)
* Patient is indicated for proximal tibia autograft harvest and iliac crest BMA (e.g. no hx bilateral TKAs or previous iliac wing trauma bilaterally).
* Patient is skeletally "mature" and presents with no concern for osteopenia/osteoporosis.
* Patient has sufficient volume of harvest material for study inclusion (minimum of 10 ml of cancellous bone graft plus 10 ml fluid pressed out from cancellous bone portion)
* Patient must speak English or have access to sufficient translator.

Exclusion Criteria:

* Patient is 70 yrs of age or older.
* Patient is unwilling or unable to give consent or comply with study protocol.
* Patient has any condition, which in the judgement of the Investigator, places the patient at undue risk or interferes with the study.
* Patient has mental or neurological disorder that will not allow for proper informed consent.
* Patient is known to be pregnant or breastfeeding.
* Patient is a vulnerable subject (prisoner, mentally incompetent or unable to understand what participation to the study entails, a known alcohol or drug abuser, and/or anticipated to be non-compliant).
* Patient has any condition, which in the judgement of the Investigator, may chemically skew bone marrow. This may include but is not limited to the following:

  * Cancer
  * Undergoing chemotherapy radiation,
  * Bone marrow transplant
  * Infection at the donor sites
  * Organ transplant on antirejection meds
  * Usage of anti-rheumatologic drugs
  * Chronic steroid usage
  * Anemia
  * Myelodysplastic Syndromes
* Patient presents with arthritis of the knee and may require knee replacement within the next 12 months.