Internal Fixation

Authors: Benjamin J. Ahern, BVSc , Dean W. Richardson, DVM , Raymond C. Boston, PhD and Thomas P. Schaer, VMD
Journal: Veterinary Surgery

Objective: To determine the rate of postoperative infection (POI) for internal fixation repaired equine long bone fractures and arthrodeses and identify associated risk factors.

Study Design: Case series.

Animals: Horses (n=192) with fracture repair of the third metacarpal and metatarsal bones, radius, ulna, humerus, tibia, and femur, or arthrodesis with internal fixation.

Authors: Gary A. Sod, DVM, PhD , Laura M. Riggs, DVM, PhD, Diplomate ACVS , Colin F. Mitchell, BVMS, MS, Diplomate ACVS , George S. Martin, DVM, MS, MBA, Diplomate ACVS , and Marjorie S. Gill, DVM, MS, Diplomate ABVP
Journal: Veterinary Surgery

Objectives: To compare the monotonic biomechanical properties and fatigue life of a 5.5-mm-broad locking compression plate (5.5 LCP) fixation with a 4.5-mm-broad locking compression plate (4.5 LCP) fixation to repair osteotomized equine 3rd metacarpal (MC3) bones.

Study Design: In vitro biomechanical testing of paired cadaveric equine MC3 with a middiaphyseal osteotomy, stabilized by 1 of 2 methods for fracture fixation.

Animal Population: Fifteen pairs of adult equine cadaveric MC3 bones.

Authors: Naoki Sasaki, DVM, PhD; Jun Takakuwa, DVM; Haruo Yamada, DVM, PhD; Ryuji Mori, MD, PhD
Journal: American Journal of Veterinary Research

Objective—To evaluate effectiveness of allogeneic bone screws and pins for internal fixation of midbody transverse fractures of equine proximal sesamoid bones (PSBs) in vitro. Sample Population—14 forelimbs from cadavers of 3-year-old Thoroughbreds. Procedures—Allogeneic cortical bone fragments were collected from the limbs of a male Thoroughbred, and cortical bone screws were prepared from the tissue by use of a precision desktop microlathe programmed with the dimensions of a metal cortical bone screw.

Authors: ASHLEE E. WATTS, DVM, Diplomate ACVS 1 , LISA A. FORTIER, DVM, PhD, Diplomate ACVS 1 , ALAN J. NIXON, BVSc, MS, Diplomate ACVS 1 , and NORM G. DUCHARME, DVM, MSc, Diplomate ACVS 1
Journal: Veterinary Surgery

Objective—To report a technique for laser-facilitated, minimally invasive proximal interphalangeal joint (PIJ) arthrodesis in horses.

Study Design—Case series.

Animals—Horses (n=6); 5 thoracic and 2 pelvic limb PIJ.

Authors: JAMES L. CARMALT, MA, VetMB, MVetSc, Diplomate ABVP & ACVS 1 , LANA DELANEY, DVM 1 , and DAVID G. WILSON, DVM, Diplomate ACVS 1
Journal: Veterinary Surgery

Objective—To compare the biomechanical cyclic fatigue properties of 2 and 3 parallel transarticular 5.5 mm cortical screws used in arthrodesis of the proximal interphalangeal (PIP) joint.

Study Design—Randomized block design, for horse, fixation method (2 versus three 5.5 mm cortical screws), side (right, left) and end (front, hind) in cadaveric equine limbs.

Sample Population—Cadaveric adult equine fore- and hindlimbs (n=5 pairs each).

Authors: GARY A. SOD, DVM, PhD 1 , Laura M. RIGGS, DVM, PhD, Diplomate ACVS 1 , COLIN F. MITCHELL, BVMS, MS, Diplomate ACVS 1 , JEREMY D. HUBERT, BVSc, MS, Diplomate ACVS 1 , and GEORGE S. MARTIN, DVM, MS, MBA, Diplomate ACVS 1
Journal: Veterinary Surgery

Objectives—To compare in vitro monotonic biomechanical properties of an axial 3-hole, 4.5 mm narrow dynamic compression plate (DCP) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion (DCP-TLS) with 3 parallel transarticular 5.5 mm cortical screws inserted in lag fashion (3-TLS) for the equine proximal interphalangeal (PIP) joint arthrodesis.

Study Design—Paired in vitro biomechanical testing of 2 methods of stabilizing cadaveric adult equine forelimb PIP joints.

Authors: ANDREW J. LEWIS, DVM 1 , GARY A. Sod, DVM, PhD 1 , DANIEL J. BURBA, DVM, Diplomate ACVS 1 , and COLIN F. MITCHELL, BVM&S, Diplomate ACVS 1
Journal: Veterinary Surgery

Objectives—To compare compression pressure (CP) of 6.5 mm Acutrak Plus (AP) and 4.5 mm AO cortical screws (AO) when inserted in simulated lateral condylar fractures of equine 3rd metacarpal (MC3) bones.

Study Design—Paired in vitro biomechanical testing.

Sample Population—Cadaveric equine MC3 bones (n=12 pair).

Authors: Roberts, B.L.; Railton, D.; Adkins, A.R.
Journal: Equine Veterinary Education

A single screw technique is described as a temporary transphyseal bridge for the treatment of fetlock varus angular limb deformity in foals. This has been compared to tension band wiring with regards to rate of correction, cosmetic result and incidence of complications. The single screw was found to be an effective technique resulting in more rapid improvement of deviations in foals aged up to 5 months. Complications were minimal following both techniques and the final cosmetic result was better following single screw surgery.

Authors: K. A. Bubeck, J. Garcia-Lopez, L. S. Maranda
Journal: Veterinary and Comparative Orthopaedics and Traumatology

Objectives: To compare heat generation and time to finish between a new step drill and sequential drilling in order to create a 6.2 mm pilot hole for insertion of a positive profile transfixation pin into the equine third metacarpal bone. Methods: Nine pairs of equine third metacarpal bones from cadavers of adult horses were used. Maximum temperature rise of the bone was measured continuously at the cis- and trans-cortices 1, 2 and 3 mm from the final pilot hole during creation of a 6.2 mm hole using a step drill and sequential drilling with 4.5, 5.5 and 6.2 mm drill bits.

Authors: RYAN R. E. WOLKER, DVM, MVetSc 1 , JAMES L. CARMALT, MA, VetMB, MVetSc, Diplomate ABVP & ACVS 1 , and DAVID G. WILSON, DVM, Diplomate ACVS
Journal: Veterinary Surgery

Objective—To compare the biomechanical characteristics, failure mode, and effects of side (left or right limb) and end (forelimb or hindlimb) of different screws in 2-screw, parallel-screw proximal interphalangeal joint arthrodesis constructs in horses.

Study Design—In vitro experimental study.

Sample Population—Twenty limbs from 6 cadavers (4 complete limb sets, 2 partial sets—total of 4 forelimb and 6 hindlimb pairs).