Bone marrow nails created by percutaneous osteoplasty for long bone fracture: comparisons among acrylic cement alone, acrylic-cement-filled bare metallic stent, and acrylic-cement-filled covered metallic stent.

PURPOSE: This study was designed to compare the strength among bone marrow nails created to treat long bone fractures using interventional procedures.

METHODS

Twelve resected intact tibiae of healthy swine were used. A circumferential bone fracture was made in nine tibiae and restored with the following created bone marrow nails: acrylic cement alone (ACA) (n=3), acrylic-cement-filled bare metallic stent (AC-FBMS) (n=3), and acrylic-cement-filled covered metallic (AC-FCMS) stent (n=3). The remaining intact tibiae (n=3) were used as controls.

RESULTS

A bone marrow nail was successfully achieved within 30 min in all swine. The maximum injection volume of acrylic cement for creating ACA, AC-FBMS, and AC-FCMS was 1.7±0.3, 3.2±0.4, and 2.9±0.4 mL, respectively. The thickness of bone marrow nail created in the ACA, AC-FBMS, and AC-FCMS groups was 3.6±1.0, 10.3±0.26, and 9.6±0.32 mm, respectively (AC-FBMS group versus AC-FCMS group, p=0.038), probably because of leakage of acrylic cement surrounding the interstices. The maximum bending power (kilonewton) and bending strength (newton/mm2) in the normal long bone, ACA, AC-FBMS, and AC-FCMS groups were: 1.70±0.25 and 79.2±16.1; 0.21±0.11 and 8.8±2.8; 0.46±0.06 and 18.2±1.6; and 0.18±0.04 and 7.8±2.7, respectively.

CONCLUSIONS

Although the maximum bending power and bending strength of AC-FBMS were not satisfactory, it was the most robust of the three marrow nails for restoring fractured long bone.