Comminuted Intra-Articular Distal Tibia Fracture Fixation Using Computer Techniques

1. Recruitment Patients with a comminuted distal tibia fracture (OTA 43-C type) who present
for care at Inova Fairfax Medical Campus (IFMC) or at the Inova Medical Group (IMG)
Orthopaedic outpatient clinic will be eligible for consent and possible enrollment in
this study. Patients will not be compensated for participating in this study. Given that
this is a convenience sample of patients who present with an acute traumatic injury,
there are no plans to advertise or recruit patients.

2. Subject Randomization and Blinding Procedures Eligible patients will be randomized in
equal proportions to one of two groups (enhanced pre-operative planning vs. SOC
pre-operative planning) using an electronic randomization system with a simple
randomization table. After consent and inclusion/exclusion criteria have been confirmed,
subjects will be randomized by a research coordinator/associate. All surgeons will be
temporarily blinded to the randomization assignment, in order to complete an unbiased
pre-operative plan (pre-randomization survey) using the SOC imaging alone (plain film
radiographs and 3D CT scan). After the pre-operative plan (pre-randomization survey) is
completed by the attending surgeon (using the SOC imaging alone) and submitted to the
research coordinator/ associate, the surgeon will be informed of the randomization
assignment. For subjects randomized to the enhanced pre-operative planning group, the
surgeon will then be provided the 3D prototype and be asked to complete a
post-randomization survey capturing their pre-operative plan. The biomechanics lab with
arrange with the research coordinator/associate for delivery of the 3D prototype,
ensuring that the temporary blinding of treatment assignment is not broken. A
post-randomization survey will not be administered to surgeons with subjects randomized
to the SOC group.

Subjects will not be blinded to the assigned group. However, in order to ensure the
temporary blind is maintained with the attending surgeon who will be performing the
definitive surgery, the subject won't be informed of their randomization assignment
until the time of definitive surgery.

3. Standard of Care Procedures Prior to Definitive Surgery: All Groups The following
pre-operative care described is the standard of practice and is a general summary of the
care that will be given to all study patients prior to their definitive surgery,
regardless of treatment group assignment. There are two scenarios with which patients
will be eligible and approached for participation in this study: 1). stable fracture
treated with a splint, and 2). unstable (open or closed) fracture requiring
external-fixator surgery.

All patients will be initially evaluated in the emergency department (ED) by a member of
the orthopaedic trauma team. Patients with an axially stable injury will undergo manual
realignment and application of a well-padded posterior with U-shaped plaster splint. A
computed tomography (CT) scanning with sagittal, coronal reconstructions and 3D
reformations will be obtained in the ED; and then sent home after learning to crutch
ambulate, with instructions for continued strict elevation, non-weight bearing, and
follow-up in the clinic. Once these patients are seen in the clinic, it is determined
that surgery is required and the patient is subsequently scheduled for definitive
surgery, to occur after resolution of swelling and normalization of skin.

Patients who present in the ED with axially unstable-closed fractures on initial plain
radiographs will undergo closed reduction and be admitted to the hospital for surgical
placement of a temporizing, spanning external-fixator (Depuy Synthes Inc. West Chester,
PA). Patients with axially unstable-open fractures will be administered intravenous
antibiotics and tetanus update on presentation to the ED, and will go to the operating
room for urgent initial debridement and placement of a temporizing, spanning
external-fixator. Patients with unstable fractures (open or closed) will have computed
tomography (CT) scanning with sagittal, coronal reconstructions and 3D reformations
after placement of an external-fixator. Patients will be discharged with appropriate
placement (home vs. acute rehab vs. SNF) after evaluation by physical therapy and have
their definitive surgery scheduled. All patients will be non-weight bearing to the study
injury limb. Definitive operative fixation will occur after resolution of swelling and
normalization of skin.

4. Study Procedures: Pre-operative Surgery Planning and open treatment and internal
fixation (ORIF) Surgery

4.1 Standard of Care In the control group, 20 patients will have standard of care
treatment, which includes pre-operative evaluation and surgical planning based on plain
films (3 views: anterior, lateral and oblique) and CT scans with sagittal, coronal and
3D reformations. Operative fixation of the fractures using distal tibia fracture
fixation implants (Depuy Synthes Inc. West Chester, PA) will be performed through
standard approaches as judged by the operating surgeon. The implants can include, but is
not limited to: 3.5 mm LCP Low Bend Medial Distal Tibia Plates, 3.5 mm LCP
Antero-lateral Distal Tibia Plates, 3.5 mm LCP Posterior Distal Tibia Plates, or 2.7 mm
/ 3.5 mm LCP Distal Fibula Plates.

4.2 Treatment Group: Enhanced Pre-Operative Planning In the treatment group, 20 patients
randomized to enhanced pre-operative planning will include a 3D prototype of the distal
tibia, fibula and talus—in addition to standard of care imaging (plain films 3 view, CT
scans with sagittal, coronal and 3D reformations). On the injured extremity, discrete
bone fragments are segmented and models of the study injury will then be imported into a
computer aided design (CAD) software Unigraphics NX8 (Siemens PLM, Plano, TX). CAD
models of the injured ankle will be converted into plastic prototypes using a Ultimaker
3D printer (Ultimaker B.V., Geldermalsen, Netherlands). Surgeons will use the 3D plastic
prototype model to understand the geometry, displacement, and ideal reduced location of
the fragments. Based on the addition of the 3D plastic prototype model, a second
pre-operative plan will be documented. This will be compared to the initial pre-op plan
to determine if the addition of the 3D prototype changed the surgeon's plan. The 3D
plastic prototypes may be brought to the operating room (in the unsterile field) for
reference during surgery as the surgeons execute the surgical plan. ORIF is then
conducted to fix the fractures as per surgeon's standard of practice. The implants can
include, but are not limited to: 3.5 mm LCP Low Bend Medial Distal Tibia Plates, 3.5 mm
LCP Antero-lateral Distal Tibia Plates, 3.5 mm LCP Posterior Distal Tibia Plates, or 2.7
mm / 3.5 mm LCP Distal Fibula Plates (Depuy Synthes Inc. West Chester, PA).

5. Baseline and Follow-Up Assessments Demographics, mechanism of injury, and fracture
classification will be collected at baseline. Patients will be followed over a 12-month
period at 6 weeks, 26 weeks, and 52 weeks postoperatively. The outcome parameters being
collected during the follow-up visits include re-operation, malunion and nonunion, other
complications, Olerud and Molander Score, Numeric Pain Rating Scale (NPRS) for pain, and
General Health Status. Radiographs as part of standard of care will be obtained of the
anterior, lateral and oblique planes (3 views) to assess healing. The Schedule of Events
details the requirements and procedures for each visit. Paper Case Report Forms (CRFs)
will be used to document each follow-up assessment (as source documentation) and will
then be entered electronically (eCRF) into an electronic data capture system. In cases
when patients are not able to come in person for a follow-up assessment and all efforts
to bring the patient in for an appointment have been exhausted, the option to complete
the follow-up via telephone interview may be completed.

5.1 Outcome Surveys Three outcome surveys will be obtained at each follow-up visit: 1)
Olerud and Molander Scoring of Symptoms after Ankle Fracture, 2) Numeric Pain Rating
Scale, and 3) General Health. The estimated total time to complete these three outcome
surveys is 5 minutes.

The Olerud and Molander Scoring of Symptoms after Ankle Fracture is a 9-question
self-assessment of pain, stiffness, swelling, ability to climb stairs, run, jump, squat,
use of supports, and work/activities of daily life. A total score out of 100 is
calculated, with 100 equaling best or completely unimpaired. The Olerud and Molander
Scoring of Symptoms after Ankle Fracture has been supported as a valid instrument,
significantly correlating to a linear analog scale used to subjectively assess ankle
function, range of motion in loaded dorsal extension, presence of osteoarthritis and
presence of dislocation on radiographs. The Olerud and Molander Score also can capture
minor subjective differences in disability and has a high correlation in test-retest
reliability.

A Numeric Pain Rating Scale (NPRS) (11-point numeric scale), a numeric version of the
Visual Analog Scale for pain, will be used to assess the subject's current pain level.
The NPRS is a 10 cm horizontal line, separated by 1cm integer increments, anchored with
0 = No Pain and 10 = Worst Possible Pain. The Numeric Rating Scale has been demonstrated
to be valid in terms of construct validity, when compared to 5 other pain intensity
measures such as Visual Analog Scale and Verbal Rating Scales. Subjects will be given
this rating scale, self-administered, to record the number that best reflects their
current pain. The NPRS takes less than 1 minute to complete. The NPRS can also be
administered verbally by telephone.

The subject's general health state will be measured using the Centers for Disease
Control and Prevention's Health-Related Quality of Life, Healthy Days Core Module
Question 1. This general health question is part of 4 items in the Healthy Days Core
Module, which can be found in several national surveys, including the Behavioral Risk
Factor Surveillance System and Medicare Health Outcome Survey. The validity of the CDC's
HRQOL has been demonstrated.

6. Statistical Analysis The statistical analysis will be conducted using SPSS (IBM, version
18.0) and statistical significance set at p < α= .05 (two-tailed). Descriptive
statistics will include frequency and percentages, as well as Chi-square analysis or
Fisher's exact test (for cell sizes less than 5), to compare any differences at baseline
between the two treatment groups. Any differences found at baseline, will be controlled
for in the analysis as a covariate/confounding. The percentage of complications, such as
infection, re-operation, malunion, and nonunion, within the two treatment groups will
also be analyzed.

When comparing differences between the SOC versus enhanced pre-operative planning group
(independent variable) and the Olerud and Molander Score and NPRS (ratio scales), both
outcome/dependent variables capture pain. Therefore, a preliminary analysis of the
correlation between these two dependent variables will be first assessed to determine
appropriateness to use a multivariate analysis of variance (MANOVA), vs. two separate
independent t-tests (Bonferroni correction α= .05/2). When comparing differences between the
SOC versus enhanced pre-operative planning group with the categorical variable of general
health, a Chi-square analysis or Fisher's exact test will be conducted.

The percentage of agreement between the pre and post-randomization pre-operative plan will be
calculated and presented as a descriptive statistic. The number of items in agreement will be
divided by the total number of items answered.

Inclusion Criteria

1. Adults 18 to 75 years old.

2. Diagnosis of a closed or open, isolated intra-articular comminuted distal tibia
fracture (OTA 43-C), with plans for delayed definitive surgery. May have concomitant
fracture or injury of fibula.

3. Standard of care imaging available for pre-operative assessment and modeling

4. English speaking.

5. Available for follow-up for 12 months.

6. Patient signs informed consent.

Exclusion Criteria

1. History of musculoskeletal disease of the foot and/or ankle (i.e. arthritis).

2. Non-ambulatory prior to injury.

3. Bilateral lower extremity fractures.

4. Fracture of ipsilateral talus or calcaneus.