Inflation osteoplasty: in vitro evaluation of a new technique for reducing depressed intra-articular fractures of the tibial plateau and distal radius

BACKGROUND: Anatomic reduction of intra-articular fractures of the tibial plateau and distal radius can be difficult to achieve. Treatment goals are centered on restoring the native anatomy and articular congruency. Several surgeons in the USA have begun using an inflatable bone tamp to reduce these fracture patterns. The concept is built on the success of the tamp in kyphoplasty of the spine, but it has yet to be tested in the lab for use in the extremities. We performed an investigation into the safety and efficacy of using an inflatable bone tamp for intra-articular fracture reduction of the tibial plateau and distal radius. MATERIALS AND METHODS: Paired cadaveric specimens were obtained for a total of six proximal tibias and six distal radii. Intra-articular depression-type fractures were created in all specimens. The inflatable bone tamp was then used to reduce the depression. For comparison, the tibias were fractured on the medial and lateral side and a conventional metal tamp was used on the contralateral side of the balloon. Fine-cut micro-computed tomography (CT) scans were performed on all intact specimens, which were then fractured, and again after fracture reduction. CT data was used to measure the amount of restoration of the normal anatomy and to compare the effectiveness of the balloon to conventional methods. RESULTS: The inflatable bone tamp was equivalent to conventional methods in large, minimally displaced fracture fragments and proved superior when comminution was present at the articular surface. No instances of overreduction or penetration into the joint were encountered with the balloon, whereas this was a common occurrence with conventional metal tamps. The inflatable tamp was successful in reducing all distal radius fractures without complication. CONCLUSION: Anatomic reduction of impacted articular fractures should be the goal of any treating surgeon. In our cadaveric models, we have shown the inflatable bone tamp to be safe and effective in reducing depressed articular fractures around the tibial plateau and distal radius. The balloon offers the advantage of being minimally invasive and creating a symmetric, contained defect to hold bone filler for subchondral support.