PDF herunterladen
Vet Comp Orthop Traumatol 2007; 20(03): 175-179
DOI: 10.1160/VCOT-06-07-0057
Original Research
Schattauer GmbH

Evaluation of compression generated by self compressing Orthofix bone pins and lag screws in simulated lateral humeral condylar fractures

B. M. Daubs
1   Department of Clinical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi, USA
,
R. M. McLaughlin
1   Department of Clinical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi, USA
,
E. Silverman
1   Department of Clinical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi, USA
,
J. Rizon
1   Department of Clinical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi, USA
› Institutsangaben
Weitere Informationen

Publikationsverlauf

Received 11. Juli 2006

Accepted 01. Juli 2006

Publikationsdatum:
21. Dezember 2017 (online)

Auch verfügbar auf
    Lizenzen und Reprints

Summary

A simulated lateral humeral condylar fracture was created in each of the 52 humeri collected from 26 dogs. One humerus from each pair was stabilized with a 2.0 mm cortical bone screw which was inserted in lag fashion. The other humerus from each pair was stabilized with a 2.2 mm threaded diameter Orthofix pin inserted across the condyle. Prior to each repair, an antirotational K-wire was placed and then the Pressurex Sensitive film was inserted in the osteotomy site in order to determine the compressive pressure (MPa), compressive force (KN), and area of compression (cm2) achieved during fixation. The maximum insertional torque achieved before stripping was measured for each implant. The mean compression generated by insertion of a 2.0 mm lag screw was 20.36 ± 1.51 MPa compared to 18.88 ± 1.76 MPa generated by a 2.2 mm Orthofix pin (p<0.003). The mean area of compression generated by insertion of a 2.0 mm lag screw was 2.39 ± 1.29 cm2, compared to 1.16 ± 0.84 cm2 generated by insertion of a 2.2 mm Orthofix pin (p<0.0001). The mean compressive force (compression x area compressed) generated by insertion of a 2.0 mm lag screw was 4.96 ± 2.90 Kn, compared to 2.20 ± 1.65 Kn generated by insertion of a 2.2 mm Orthofix pin (p<0.0001). The mean insertion torque to failure for the lag screws was 0.49 ± 0.07 NM, compared to 0.91 NM ± 0.18 NM generated by the Orthofix pins (P<0.0001). Both repair methods are likely to be acceptable for the repair of similar fractures in small breed dogs.

Keywords

Humeral condylar fracture - Orthofix pin - compression
 

  • References

  • 1 Bardet JF, Hohn RB, Rudy RL. Fractures of the humerus in dogs and cats a retrospective study of 130 cases. Vet Surg 1983; 12: 73-77.
    CrossrefPubMedGoogle Scholar
  • 2 Vannini R, Smeak DD, Olmstead ML. Evaluation of surgical repair of 135 distal humeral fractures in dogs and cats. JAmAnim Hosp Assoc 1988; 24: 531-536.
    PubMedGoogle Scholar
  • 3 Vannini R, Olmstead ML, Smeak DD. An epidemiological study of 151 distal humeral fractures in dogs and cats. JAmAnim Hosp Assoc 1988; 24: 531-536.
    PubMedGoogle Scholar
  • 4 Deny JR. Condylar fractures of the humerus in the dog: a review of 133 cases. J Small Anim Pract 1988; 24: 185-197.
    PubMedGoogle Scholar
  • 5 Rorvik AM. Risk factors for humeral condylar fractures in the dog: A retrospective study. J Small Anim Pract 1993; 34: 277-282.
    CrossrefPubMedGoogle Scholar
  • 6 Meyer-Lindberg A, Heinen V, Fehr M. et al. Incomplete ossification of the humeral condyle as the cause of lameness in dogs. Vet Comp Orthop Traumatol 2002; 3: 187-194.
    Artikel in Thieme ConnectPubMedGoogle Scholar
  • 7 Butterworth Butterworth, Innes JF. Incomplete humeral condylar fractures in the dog. J Small Anim Pract 2001; 42: 394-398.
    CrossrefPubMedGoogle Scholar
  • 8 Unger M, Montavon PM, Heim UFA. Classification of fractures of the long bones in the dog and cat: Introduction and clinical application. Vet Comp Orthop Traumatol 1990; 3: 41-50.
    Artikel in Thieme ConnectPubMedGoogle Scholar
  • 9 Marcellin-Little DJ, DeYoung DJ, Ferris KK. et al. Incomplete ossification of the humeral condyle in spaniels. Vet Surg 1994; 23: 475-487.
    CrossrefPubMedGoogle Scholar
  • 10 Kaderly Kaderly, Lamothe M. Incomplete humeral condylar fracture due to minor trauma in a mature cocker spaniel. JAmAnim Hosp Assoc 1994; 28: 475-487.
    PubMedGoogle Scholar
  • 11 Matthiesen Matthiesen, Walter M. Surgical management of distal humeral fractures. Compend Contin Educ Pract Vet 6 1984; 1027-1036.
    PubMedGoogle Scholar
  • 12 Cook JL, Tomlinson FL, Reed AL. Fluoroscopi- cally guided closed reduction and internal fixation of fractures of the lateral portion of the humeral condyle: prospective clinical study of the technique and results in ten dogs. Vet Surg 1999; 28: 315-321.
    CrossrefPubMedGoogle Scholar
  • 13 Lanz OI, Lewis DD, Newell SM. Stabilization of a physeal fracture using an Orthofix partially- threaded Kirschner wire. Vet Comp Orthop Traumatol 1999; 12: 88-91.
    Artikel in Thieme ConnectPubMedGoogle Scholar
  • 14 Larsen LJ, Roush JK, McLaughlin RM. et al. Microangiography of the humeral condyle in cocker spaniel and non-cocker spaniel dogs. Vet Comp Orthop Traumatol 1999; 12: 134-137.
    Artikel in Thieme ConnectPubMedGoogle Scholar
  • 15 Herron MR. Lateral condylar fractures of the humerus: amethod of closed repair. Canine Practice 1975; Jan-Feb 30-34.
    PubMedGoogle Scholar
  • 16 Guille AE, Lewis DD, Anderson TP. et al. Evaluation of surgical repair of humeral condylar fractures using self-compressing orthofix pins in 23 dogs. Vet Surg 2004; 33: 314-322.
    CrossrefPubMedGoogle Scholar
  • 17 Elkins AD, Tangner CH, Herron MR. Lag screw fixation of capitular fractures of the humerus. Calif Vet 1982; 1: 13-16.
    PubMedGoogle Scholar
  • 18 Anderson TJ, Carmichael S, Miller A. Intercondylar humeral fracture in the dog: A review of 20 cases. J Small Anim Pract 1992; 31: 437-442.
    PubMedGoogle Scholar
  • 19 Vida JT, Pooya H, Sasseur PB. et al. Biomech- anical comparison of Orthofix pins and cortical bone screw is a canine humeral condylar fracture model. Vet Surg 2005; 34: 491-498.
    CrossrefPubMedGoogle Scholar
  • 20 Johnson KA, Smith FW. Axial compression generated by cortical and cancellous lag screws in the distal phalanx. Vet J 2003; 166: 159-163.
    CrossrefPubMedGoogle Scholar
  • 21 Phillips Phillips, Rahn BA. Comparison of compression and torque measurements of self-tapping and pretapped screws. Plast Reconstr Surg 1989; 83: 447-458.
    CrossrefPubMedGoogle Scholar
  • 22 Draper ER, Wallace AL, Strachan RK. et al. The design and performance of an experimental external fixation device with load transducers. Med Eng Phys 1995; 17: 618-24.
    CrossrefPubMedGoogle Scholar
  • 23 Galuppo LD, Stover SM, Jensen DG. et al. A biomechanical comparison of headless tapered variable pitch and AO cortical bone screws for fixation of a simulated lateral condylar fracture in equine third metacarpal bones. Vet Surg 2001; 30: 332-340.
    CrossrefPubMedGoogle Scholar
  • 24 Rovinsky D, Haskell A, Liu Q. et al. Evaluation of a new method of small fragment fixation in a medial malleolus fracture model. J Orthop Trauma 2000; 14: 420-425.
    CrossrefPubMedGoogle Scholar
  • 25 Field JR, Hearn TC, Caldwell CB. The influence of screw torque, object radius of curvature, mode of bone plate application and bone plate design on bone-plate interface mechanics. Injury 1998; 29: 233-241.
    CrossrefPubMedGoogle Scholar
  • 26 Field JR, Hearn TC, Caldwell CB. Bone plate fixation: an evaluation of interface contact area and force of the dynamic compression plate (DCP) and the limited contact-dynamic compression plate (LC-DCP) applied to cadaveric bone. J Othop Trauma 1997; 11: 368-373.
    PubMedGoogle Scholar
  • 27 Field JR, Edmonds-Wilson R, Stanley RM. An evaluation of the interface contact profiles in two low contact bone plates. Injury 2004; 35: 551-556.
    CrossrefPubMedGoogle Scholar
  • 28 Braitman LE. Confidence Intervals Assess both Clinical Significance and Statistical Significance. Annals of Internal Medicine 1991; 114: 515-517.
    CrossrefPubMedGoogle Scholar
  • 29 Prieur WD, Sumner-Smith G. Interfragmentary compression. In Manual of Internal Fixation in Small Animals. Brinker WO, Hohn RB, Prieur WD. (eds). Berlin: Springer-Verlag; 1984: 29-30.
    Google Scholar