Intraoperative 3D imaging
Maayan Kosovsky

Introduction
• Fluoroscopy - intraoperative analysis of fracture reduction and
implant placement
• Summation effect- concave shape of the tibial plateau
• assessment of the complete articular surface may not be
possible
• Post operative CT needed to evaluate the surgical result

Introduction
• gold standard - post-operative CT
• malreduction or implant misplacement, the patient might need
secondary revision surgery
• Intraoperative 3D imaging similar to CT detecting malreduction
and implant malposition that were not visible in fluoroscopy

Tibial Plateau
• Tibial plateau fractures 1% of all fractures
Treatment:
• Conservatively
- minimally displaced split or depressed fractures
- low energy fracture stable to varus/valgus alignment
- non-ambulatory patients
- significant co-morbidites that preclude surgical intervention
• Dislocated articular tibial plateau fractures,
surgical management - gold standart

Tibial Plateau
• Frequently associated with soft tissue injury
• Lateral plateau 70-80%
bicondylar 10-30%
medial plateau 10-20%

AO/OTA classification

Tibial Plateau- ORIF
Indications
• articular depression > 5-10 mm
• condylar widening > 5mm
• varus/valgus instability >10 deg
• medial plateau fractures
• bicondylar fractures
Goals
• restore alignment
• normal condylar width
• congruent articular surface
• stable knee
• minimize additional soft tissue trauma

Study Aims
• Evaluate intraoperative revision rate and reasons for revision
following 3D imaging
• Hypothesis- insufficient reduction or implant malposition may
not be visible in fluoroscopy but can be visualized in
intraoperative 3D imaging

Materials and Methhods
• Retrospective study
• Patients who underwent surgery for type B or C tibial plateau fracture
• Between August 2001 and December 2017 and whose results were
verified using intraoperative 3D imaging

Materials and Methhods
The revisions were classified:
• Improvement in reduction with articular step-offs of > 2 mm
• Replacement of an intraarticular screw
• Replacement of a screw with one of a different length
• Other consequence

Results
• 559 fractures
• Type B3 (37.4%), C3 (30.4%), B2 (15.9%),
B1 (7.9%), C2 (4.5%), C1 (4.3%)

Results
148 out of 559 cases (26.5%)- immediate intraoperative revision
after using intraoperative 3D imaging
• improved reduction result was achieved in 114 cases
• Intraarticular screw was replaced in 5 cases
• A different screw length was used in 21 cases (17 cases shorter screw,
4 cases longer screw)

Results
“Other consequences”:
• 3 cases- an intraarticular bone fragment was removed which was not visible in fluoroscopy
• 2 cases, an additional screw was inserted to support the reduction
• 1 case, a plate projected proximally was corrected
• 5 cases, the position of a screw was altered to achieve better fixation of a fragment
• 2 cases, an additional defect was discovered which was not visible in fluoroscopy
• 1 case, a lateral fragment could not be fixed and discarded
• 1 case, it was found that a central fragment could not be reached via the lateral approach making
an additional dorsal approach
• 1 case, additional plate was necessary to achieve stabilization

Discussion
At least one revision based on 3D imaging in 26.5% of the cases
• Improvement in reduction- 72.6%
• AO/OTA- type C3 (multifragment)- 32.4%, B3 (split depression)- 27.5%
• Detection of intraarticular bone fragments

Discussion

Discussion
• 3D imaging offers an advantage over conventional imaging for
all dislocated articular tibial plateau fractures
• Improves the visualization of insufficient anatomical reduction,
malpositioned implants, and intraarticular fragments
• Immediate correction is possible
• Subsequent surgery or an impaired clinical/ radiological
outcome prevented

Limitations
• Restricted C- arm image can only display 12 × 12 × 12 cm
• Lack of proof of the clinical benefit, only radiological consequences
resulting from the intraoperative 3D imaging were examined
• Case control analysis (ethical problem)
• Consequences of a prolonged operation time of about
5 min per scan have not been investigated

Conclusion
• Correct alignment of the tibial plateau is difficult to
evaluate using conventional fluoroscopy
• Intraoperative 3D imaging appears to be beneficial for
the analyzation of reduction and implant placement
• If intraoperative 3D imaging is not available,
a postoperative CT should be considered

Take home message
• Summation effects- conventional fluoroscopy is limited
• 3D imaging offers an advantage over conventional imaging
in articular fractures