Inferior fixation with a new pin design for external fixation: a randomized study in 50 patients operated on by the hemicallotasis technique.
OBJECTIVE
Tibial osteotomy by the hemicallotasis technique (HCO) requires strong pin fixation. We compared pin fixation in HCO using a new self-drilling XCaliber pin (Orthofix) with optimized thread and tip design, with the commonly used standard pin (Orthofix).


METHODS
50 patients, mean age 51 (35-66) years, to be treated by HCO were randomized to standard pins or XCaliber pins. In the metaphyseal bone, hydroxyapatite-coated (HA-coated) pins were used in both types of pins. In the diaphyseal bone, non-coated pins were used. The torque forces for insertion and extraction (in Nm) were measured.


RESULTS
The insertion torque was higher for both the proximal and distal standard pins (2.1 Nm (SD 0.9) and 7.0 Nm (1.3), respectively) than for the XCaliber pins (1.3 Nm (0.8) and 3.6 Nm (1.4)). The extraction torque force was higher for the proximal standard pins (4.3 Nm (3.1)) than for the proximal XCaliber pins (1.5 Nm (1.7)) (p < 0.001). The extraction torque for the distal standard pins was 1.9 Nm (2.0) and for the distal XCaliber pins it was 1.4 Nm (1.1).


CONCLUSIONS
The commonly used standard pin gives stronger fixation during the treatment of HCO.
Toksvig-Larsen
Sören
S
Department of Orthopedics, Lund University Hospital, Lund, Sweden. Soren.Toksvig-Larsen@med.lu.se
W-Dahl
Annette
A
D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D001858:Bone Nails / Q000009:adverse effects; D020099:Coated Materials, Biocompatible; D017886:Durapatite; D004867:Equipment Design; D005260:Female; D005593:Fracture Fixation, Internal / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D017102:Fracture Healing; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery; D010027:Osteotomy / Q000295:instrumentation* / Q000379:methods; D013977:Tibia / Q000601:surgery
D020099:Coated Materials, Biocompatible; D017886:Durapatite