Journal of orthopaedic trauma
-
Review
State of the art review: techniques to avoid pin loosening and infection in external fixation.
The purpose of this manuscript is to review techniques of optimizing the interface between the bone and pin in external fixation to minimize pin loosening and infection. ⋯ Among the different techniques to improve the bone-pin interface in external fixation, coating the pins with hydroxyapatite proved to be the most effective. In a highly loaded animal study, three pin types were compared. Type A remained uncoated, type B was coated with hydroxyapatite, and Type C was coated with titanium. Radiographic rarefaction of the bone pin tract was lower in type B pins. Extraction torque was thirteen times higher in type B pins compared to type A and two times higher compared to type C pins. Extraction torque was significantly lower compared to the corresponding insertion torque in both types A and C. In contrast, in the hydroxyapatite coated pins there was no difference between extraction and insertion torque. At sixty times magnification, bone pin contact of type B and C pins was significantly higher than type A. At 10,000 times magnification direct bone pin contact was found only in type B pins. In a clinical study the pin insertion and extraction torque forces were measured in a study of seventy-six external fixation pins in nineteen patients treated with hemicallotasis for osteoarthritis of the medial side of the knee. The patients were randomized to be treated with either standard tapered pins or tapered pins coated with hydroxyapatite. Extraction torque of the hydroxyapatite coated pins was higher than the standard ones in both cancellous and cortical bone. These studies show that in hydroxyapatite coated pins there is no deterioration of the bone-pin interface strength and there is optimal bone-pin contact. Among the various pin types coated with hydroxyapatite, the best results were obtained with the tapered pins.
-
To evaluate the unreamed femoral nail with spiral blade (UFN-SB) in the treatment of nonpathologic subtrochanteric and segmental femoral fractures. ⋯ There is predictive value of the Seinsheimer classification as to outcome using UFN-SB. The UFN-SB is an option for the treatment of subtrochanteric or segmental fractures of the femur, especially in patients with a good quality of bone. The complications using this device are not caused by the learning curve, but by the characteristics of the implant and the type of fracture for which it is used. The implant should not be used in elderly women with a reversed oblique fracture or a subtrochanteric fracture with an intertrochanteric component.
-
To determine the biomechanical characteristics of four different fixation constructs for split depression fractures of the lateral tibial plateau (OTA classification 41B3.1). ⋯ There was no significant difference in the overall construct stiffness between the four fixation constructs. Fixation constructs with a raft of subchondral screws were more resistant to local depression loads. This supports the use of a raft construct when a central depression is a significant component of the overall fracture pattern. Condylar tilt data showed a persistent weakness in the postfixation lateral plateau regardless of fixation construct when compared with the intact specimen. This supports the current clinical practice of delayed weight-bearing for ten to twelve weeks.
-
Comment Letter Review
Paradoxical fat embolism after intramedullary rodding.