Controlled segmental balloon kyphoplasy: a new technique for patients with heterogeneous vertebral bone density.

STUDY

DESIGN

Case series.

OBJECTIVE

To describe a novel kyphoplasty procedure that gives uniform bone expansion in treatment of vertebra with heterogeneous bone structure.

SUMMARY OF BACKGROUND DATA: Balloon kyphoplasty is used to treat vertebral compression fractures by restoring vertebral height and correcting kyphosis before the injection of bone cement that stabilizes the fracture. In vertebra with heterogeneous bone structure, balloon expansion may be nonuniformly as a result of this heterogeneity and could result in inadequate fracture reduction.

METHODS

In the first part of the procedure, the balloon remains partially in its introducer trocar to inflate only the distal segment of balloon in the stronger bone area that provides high mechanical resistance. This segmental inflation creates a cavity that will allow to initiate fracture reduction in the stronger bone area. In the second part of the procedure, the emerging segment is deflated and the balloon is advanced until it emerges completely from the introducer trocar, after which the balloon is inflated totally in the vertebral body. Seven vertebrae in 5 patients (mean age of 71.4 years) were managed with this procedure. Etiology of fractures included myeloma (2 patients, 4 vertebrae) and senile osteoporosis (3 patients, 3 vertebrae). Twenty-millimeter long kyphoplasty balloons were used in all vertebrae. Polyméthylmetacrylate bone cement was used to fill the cavities. Technical, anatomic and clinical parameters were used for evaluation of the procedure.

RESULTS

No complications occurred on balloon inflation. Mean volume of cement injected was 5.8 mL (range, 5-6 mL). Mean maximal inflation pressure was 200 PSI (range, 150-300 PSI). One (14.8%) cement leak was observed at 1 vertebra. Mean restoration of maximal lost height was 42.8% (range, 25%-52.9%). Mean reduction in local kyphosis was 4.4 degrees (range, 0-10 degrees ). All 5 patients were pain free at 1 month post procedure. Morbidity and mortality were nil.

CONCLUSION

The described procedure allows for uniform bone expansion and adequate fracture reduction in vertebrae with heterogeneous bone structure.