Posterior Spinal Fusion With Two Energy Dissection Techniques

The primary objective is to compare intraoperative blood loss between surgeries performed
with monopolar electrocautery and ultrasonic energy (as the primary means for soft tissue
dissection) in patients diagnosed with adolescent scoliosis undergoing multilevel (>=6)
posterior spinal fusion (PSF).

This is a prospective, multicenter, pair-matched comparison study that will be carried out in
two phases:

Phase I Perioperative outcome variables (primary and secondary) will be collected from
patients with adolescent scoliosis, meeting the study inclusion criteria, scheduled to
undergo PSF using monopolar electrocautery and metal Cobb elevator (considered the current
standard) for soft tissue dissection and removal from vertebral surfaces. This group will be
the Electrocautery Dissection (ED) group.

Phase II The same outcomes variables measured on the ED group during Phase I will be
subsequently collected from a group of patients with adolescent scoliosis, meeting the study
inclusion criteria and scheduled to undergo PSF surgery. For this study group, surgery will
be performed with the Harmonic OSTEOVUE™ Spine Soft Tissue Dissector (referred to as the
OSTEOVUE™ Dissector in this protocol) and metal Cobb elevator, as the primary means of soft
tissue dissection and removal from vertebral surfaces. This group will be the Ultrasonic
Dissection (UD) group.

Patients in the UD group will be recruited from the existing patient population of PSF
candidates at each participating site.

Prior to recruitment of participants in Phase II, each Principal Investigator (PI) will have
documented training/in service of the use the OSTEOVUE™ Dissector in at least 5 multilevel
spine surgery cases.

The proportion of neuromuscular versus idiopathic cases recruited in Phase II will be based
on the proportion of patients with either of these conditions recruited in Phase I.

Up to five US sites of orthopedic surgeons and/or neurosurgeons, with expertise in pediatric
PSF surgery, will participate in the study. 100 subjects will be enrolled in this study (46
in the ED group and 54 in the UD group).

Propensity score matching will be utilized to match subjects in the ED group to subjects in
the UD group. Propensity scores will be based on the variables known to influence blood loss,
and full details of the matching methodology will be provided in a separate Statistical
Analysis Plan.

Inclusion Criteria:

1. Between 10 and 21 years of age;

2. Diagnosed with neuromuscular scoliosis associated with cerebral palsy or with
idiopathic scoliosis between the ages of 10 and 18;

3. Indicated for primary PSF surgery;

4. Anticipated >= 6 vertebrae fusions;

5. Not in need of three column osteotomy (pedicle subtraction osteotomy [PSO]);

6. Not in need of vertebral column resection (VCR);

7. Curve magnitude >45 degrees for scoliosis and for sagittal deformity; and

8. An American Society of Anesthesiologists (ASA) physical status (PS) classification of
1 to 4

Exclusion Criteria:

1. One or both parents or a guardian unable or unwilling to provide parental permission
and child assent (if capable, the child must express willingness to participate);

2. Previous failed vertebral fusion at same target levels;

3. Syndromic scoliosis;

4. Congenital scoliosis;

5. Early-onset scoliosis (onset before 10 years of age);

6. Requiring an anterior procedure;

7. Requiring PSO;

8. Requiring VCR;

9. Presence of coagulation abnormalities;

10. Planned staged procedure (exclude if second stage or beyond);

11. Requiring emergency surgery; and/or

12. Participation in any other clinical study (not to include registry or survey-only
studies) for the duration of the study.