Comparison of Actifuse ABX and Local Bone in Spinal Surgery

The current method for posterolateral lumbar fusion surgeries utilizes autograft bone
typically derived from the patient's iliac crest. However, complications have been reported
concerning the use of iliac crest bone, that include additional healing time due to the
secondary surgical site and gait abnormalities. Clinicians are in need of an adequate
alternative, and many have begun testing growth factors or synthetic compounds used in
conjunction with local bone autografts. Though this avoids the need for a secondary surgical
site, synthetic materials are not without their own limitations. These compounds must
achieve similar growth and fusion rates as native bone. This study will test the
applicability of Actifuse, a synthetic bone graft substitute, in instrumented multi-level
adult spinal deformity surgery.

Actifuse is a silicate substituted calcium phosphate. It is osteostimulative, and is a bone
void filler intended for orthopedic applications such as a filler for gaps and voids that
are not intrinsic to the stability of the bony structure. Actifuse has several features that
mimic human bone (amount of silicon, resorption rate, etc). It provides a scaffold for
long-term bone healing and is intended to be packed gently into bony voids or gaps of the
skeletal system, i.e. extremities, pelvis and spine including use in posterolateral spinal
fusion procedures with appropriate stabilizing hardware. These defects may be surgically
created osseous defects or osseous defects created from traumatic injury to the bone. The
product provides a bone void filler that is resorbed and replaced by native bone during the
healing process.

Actifuse accelerates bone growth by combining an interconnected macro- and micro- porous
structure with osteostimulative chemistry created through a patented silicate substitution
process to attach and stimulate osteoprogenitor cells (OPCs) and mesenchymal stem cells
(MSCs). It resists irrigation and can be easily viewed on x-rays to monitor healing.
Previous groups have shown that Actifuse is successful in the laboratory as well as in
patients; however, previously reported literature has not studied the efficacy of Actifuse
in instrumented multi-level adult spinal deformity.

Based on previous literature, investigators expect the Actifuse ABX to successfully fuse to
native bone growth and promote fusion as well as an autograft replacement. Potential
pitfalls include Actifuse not functioning as well in place of native bone. If this occurs,
investigators will conduct revision surgery to ensure proper bone union.

The success of this project could have significant effects for the society at large. It is
estimate that over 200,000 arthrodeses are performed each year, and the autologous iliac
crest bone graft is often considered the standard of care, therefore these results could
improve the outcome of surgery for thousands of patients every year. In addition, it will
likely cut down on time the surgeon is in the operating room. It could also speed patient
recovery by 1) lowering the amount of autologous bone harvested from the patient, and 2)
taking advantage of the properties of Actifuse (osteostimulation, resorption rate, etc) that
should result in quicker bone fusing and healing.

Inclusion Criteria:

- Patient aged 18 to 80

- Patient received primary diagnosis of adult spinal deformity (with fusion of >2
levels)

- Patient is a candidate for multi-level posterior lumbar fusion

- Patients that do not meet any of the exclusion criteria

Exclusion Criteria:

- Non-English speaker

- Current Smoker

- Prisoner

- Patient with any of the following:

Severe degenerative disease Inflammatory bone disease (e.g. osteomyelitis) Metabolic bone
disease Radiation bone therapy Existing acute or chronic infections Abnormal calcium
metabolism Hypocalcaemia Severe vascular or neurological disease Cardiovascular disease
precluding elective surgery Uncontrolled diabetes Severely impaired renal function
Documented renal disease Malignant tumors Pregnant or nursing