The pin-bone interface is critical in maintaining a stable external skeletal fixator to allow bony union and prevent complications related to loose pins (3, 7, 13, 14, 16, 17). Threaded pins have increased pull-out strength in comparison to smooth pins and have improved the bone-pin interface (1, 2, 4, 12, 16, 21). Pull-out strengths were compared between smooth Kirschner size pins and Imex™ Miniature Interface Fixation Half Pins in a polyurethane foam bone model. The negative profile end threaded pins had significantly higher pull-out strengths (p <0.001) than smooth pins. Increasing the diameter of the pin and the length of engagement also increased the pull-out strengths of both pin types. Improving the pull-out strength of pins should minimize morbidity of external skeletal fixators used in repair of mandibular/maxillary fractures or long bone repairs on small and exotic patients.
1
Anderson MA,
Mann FA,
Kinden DA,
Wagner-Mann CC.
Evaluation of Cortical Bone Damage and Axial Holding Power of Nonthreaded and Enhanced Threaded Pins Placed With and Without Drilling of a Pilot Hole in Femurs From Canine Cadavers. JAVMA 1996; 06: 883-7.
2
Anderson MA,
Mann FA,
Wagner-Mann C,
Hahn AW,
Jiang BL,
Tomlinson JL.
A Comparison of Nonthreaded, Enhanced Threaded, and Ellis Fixation Pins Used in Type I External Skeletal Fixators in Dogs. Vet Surg 1993; 22: 482-9.
4
Bennett RA,
Egger EL,
Histand M,
Ellis AB.
Comparison of the Strength and Holding Power of 4 Pin Designs for Use with Halft Pin (Type I) External Skeletal Fixation. Vet Surg 1987; 16: 207-11.
6
Chapman JR,
Harrington RM,
Lee KM,
Anderson PA,
Tencer AF.
Kowalski
Factors Affecting the Pull-out Strength of Cancellous Bone Screws. J Biomech Eng 1996; 118: 391-8.
8
Clary EM,
Roe SC.
In Vitro Biomechanical and Histological Assessment of Pilot Hole Diameter for Positive-Profile External Skeletal Fixation Pins in Canine Tibia. Vet Surg 1996; 25: 453-62.
9
Cook WT,
Smith MM,
Markel MD,
Grant W.
Influence of an Interdental Full Pin on Stability of an Acrylic External Fixator for Rostral Mandibular Fractures in Dogs. AJVR 2001; 62: 576-80.
10
Davis M,
Schulz KS,
Fawcett A,
Slater MR,
Roths JB.
Flexural and Torsional Analysis of Five Acrylics for Use in External Skeletal Fixation. Vet Comp Orthop Traumatol 1998; 11: 53-8.
12
Sandman
Dernell WS,
Harari J.
Blackketter
et al. A Comparison of Acute Pull-out Strength Between Two-Way and One-Way Transfixation Pin Insertion for External Skeletal Fixation in Canine Bone. Vet Surg 1993; 22: 110-4.
15
Field JR,
Hearn TC,
Arighi M.
Investigation of Bioabsorbable Screw Usage for Longbone Fracture Repair in the Horse: Biomechanical Features. Vet Comp Orthop Traumatol 1993; 06: 42-6.
18
Marti JM,
Roe SC.
Biomechanical Comparison of the Trocar Tip Point and the Hollow Ground Tip Point for Smooth External Skeletal Fixation Pins. Vet Surg 1998; 27: 423-8.
19
McDonald DE,
Palmer RH,
Hulse DA,
Neigut JS,
Hyman WA,
Slater MR.
Holding Power of Threaded External Skeletal Fixtaion Pins in the Near and Far Cortices of Cadaveric Canine Tibiae. Vet Surg 1994; 23: 488-93.
21
Palmer RH,
Hulse DA,
Hyman WA,
Palmer DR.
Principles of Bone Healing and Biomechanics of External Skeletal Fixation. Vet Clin North Am 1992; 22: 45-68.
23
Ross JT,
Matthiesen DT.
The Use of Multiple Pin and Methylmethacrylate External Skeletal Fixation for the Treatment of Orthopedic Injuries in the Dog and Cat. Vet Comp Orthop Traumatol 1993; 06: 115-21.
25
Shahar R.
Relative Stiffness and Stress of Type I and Type II External Fixators: Acryilic Versus Stainless-Steel Connecting Bars A Theoretical Approach. Vet Surg 2000; 29: 59-69.
28
Wilier RL,
Egger EL,
Histand MB.
Comparison of Stainless Steel Versus Acrylic for the Connecting Bar of External Skeletal Fixators. JAAHA 1991; 27: 541-8.
