Comparison of Computer-Assisted Surgery with Conventional Technique for the Treatment of Axial Distal Phalanx Fractures in Horses: An In Vitro Study (original) (raw)

Computer-Assisted Surgery for Screw Insertion into the Distal Sesamoid Bone in Horses: An In Vitro Study

Veterinary Surgery, 2006

Objective-To compare the precision of computer-assisted surgery with a conventional technique (CV) using a special guiding device for screw insertion into the distal sesamoid bone in horses. Study Design-In vitro experimental study. Sample Population-Cadaveric forelimb specimens. Methods-Insertion of a 3.5 mm cortex screw in lag fashion along the longitudinal axis of intact (non-fractured) distal sesamoid bones was evaluated in 2 groups (8 limbs each): CV and computer-assisted surgery (CAS). For CV, the screw was inserted using a special guiding device and fluoroscopy, whereas for CAS, the screw was inserted using computer-assisted navigation. The accuracy of screw placement was verified by radiography, computed tomography, and specimen dissection. Results-Surgical precision was better in CAS compared with CV. Conclusion-CAS improves the accuracy of lateromedial screw insertion, in lag fashion, into the distal sesamoid bone. Clinical Relevance-The CAS technique should be considered for improved accuracy of screw insertion in fractures of the distal sesamoid bone.

Use of Computed Tomography in Standing Position to Identify Guidelines for Screw Insertion in the Distal Phalanx of Horses: An Ex Vivo Study

Veterinary Surgery, 2009

Objectives-To compare the precision of radiography and computed tomography (CT) preoperatively in the standing position for identification of guidelines for screw insertion in the distal phalanx, and to identify whether standing CT might improve operative time compared with preoperative radiographic planning. Study Design-Experimental ex vivo study. Animals-Cadaveric equine thoracic limb pairs (n ¼ 10). Methods-Insertion of a 4.5 mm cortex screw in lag fashion into an intact distal phalanx was evaluated in 2 groups (n ¼ 10) of cadaveric equine thoracic limbs. In 1 group, the site, direction, and length of the implant were determined by radiography, and in the other group, by CT. Accuracy of screw placement was verified by specimen dissection. Outcomes were (1) absence of penetration of the articular surface, the solar surface, or the semilunar canal (2) appropriate length and direction of the screw. Surgical time was also measured. Results-No screw penetrated the articular surface, the solar surface, or the semilunar canal in either group. CT was more accurate to identify guidelines for screw insertion (U ¼ 23.50, P ¼ .049). With CT, surgical time (mean, 7.7 minutes) was significantly shorter (U ¼ 0.000, P ¼ .000) than with radiography (mean, 12.7 minutes). Conclusion-Standing CT can be used to accurately determine anatomic landmarks for screw insertion in lag fashion in sagittal fractures of the distal phalanx. Clinical Relevance-This study has a clear clinical relevance for improved internal fixation of sagittal fractures of the distal phalanx.

Evaluation of a Novel Screw Position in a Type III Distal Phalanx Fracture Model: An Ex Vivo Study

Veterinary surgery : VS, 2015

Mechanical evaluation of a novel screw position used for repair in a type III distal phalanx fracture model and assessment of solar canal penetration (SCP). Experimental study. Disarticulated equine hooves (n = 24) and 24 isolated distal phalanges. Hooves/distal phalanges cut in a sagittal plane were repaired with 1 of 2 different cortical screw placements in lag fashion. In group 1 (conventional screw placement), the screw was inserted halfway between the proximal border of the solar canal (SC) and the subchondral bone surface on a line parallel to the dorsal cortex, whereas in group 2, the screw was inserted more palmar/plantar, where a perpendicular line drawn from the group 1 position reached the palmar/plantar cortex. Construct strength was evaluated by 3-point bending to failure. SCP was assessed by CT imaging and macroscopically. Screws were significantly longer in group 2 and in forelimbs. Group 2 isolated distal phalanges had a significantly more rigid fixation compared wit...

Long‐term clinical and radiographic results after lag screw ostheosynthesis of short incomplete proximal sagittal fractures of the proximal phalanx in horses not used for racing

Veterinary Surgery, 2019

Objective: To determine long term outcomes of nonracing equines athletes treated for short incomplete proximal sagittal fractures of the proximal phalanx (SIPSFP1) by lag screw fixation. Study design: Retrospective study. Sample population: Thirty-one horses. Methods: Medical records from horses with an SIPSFP1 (2008-2014) were reviewed. Long-term (≥12 months) outcomes were assessed with telephone interviews and clinical and radiographic examinations. Results: Warmblood was the predominant breed in cases included in the study. Among horses with long-term interview information, 27 of 31 returned to previous athletic activity level. In total, 15 horses with 19 fractures had clinical and radiographic assessment after a minimum of 12 months. Among those, nine of 15 horses were sound at the trot, and six of 15 were mildly lame. Complete radiographic healing was confirmed in six limbs, and the facture line was evident in 13. The position of the proximal screw was not associated with radiographic fracture healing or return to soundness. Conclusion: Most horses treated for SIPSFP1 with lag screw fixation returned to previous activity levels, although radiographic fracture healing remained incomplete 12 months or more after surgery. Clinical significance: Lag screw fixation is a valid treatment for horses not used for racing that are experiencing an SIPSFP1 and results in a high rate of return to intended use, although complete radiographic fracture healing cannot be expected.

Internal Fixation of Fractures of the Third Phalanx in Three Horses

Australian Veterinary Journal, 1979

The technique of internal fixation of intra-articular fractures of the third phalanx using lag screw interfragmentary compression is described. Three cases are discussed and the successful treatment of infection and osteomyelitls described in one of them. Despite this potential complication internal fixation offers a better prognosis and also a more rapld return to work than non-operative treatments.

Management and outcome of fractures of the distal phalanx: A retrospective study of 285 horses with a long term outcome in 223 cases

Veterinary Journal

A multicentre study of 285 cases was performed to enhance the management of distal phalangeal fractures on the basis of clinical evidence. The outcome after treatment was available for 223 of the cases. Horses with a non-articular type I fracture had a better prognosis (91.7%) for return to original or expected level of use than horses with an articular type II or III fracture (69.6% and 74.1%, respectively). The prognosis for types IV and V fractures was fair (57.7% and 57.1%, respectively) and for type VI good (80%). Horses with a hindlimb fracture had a significantly greater chance of a successful outcome. No significant association between age or time to start treatment and success rate was noted. The best treatment option for types I–III fractures was a conservative approach (box rest). Type IV fractures were best treated by arthroscopic removal of the fragment. Immobilisation of the hoof did not seem to influence outcome. Radiological findings and clinical healing were not accurately correlated and the re-commencement of training should be based on clinical rather than radiological findings. Complete osseous union of the fracture was not essential for a successful return to athletic activity.

Introduction of 3.5mm and 4.5mm cortex screws into the equine distal sesamoid bone with the help of the VetGate Computer Assisted Surgery Systems and comparison of the results with the previously reported ones, acquired with the SurgiGATE 1.0 System – an in vitro study

Pferdeheilkunde, 2017

The in vitro experimental study was performed to evaluate the functionality and accuracy of the VetGate Computer Assisted Surgery (CAS) System and compare the results with those achieved with the SurgiGATE System previously reported. On ten cadaveric equine limb pairs free of major phalangeal pathologies (n = 20) either a 3.5 mm or 4.5 mm cortex screw was inserted in lag fashion across a virtual midsagittal fracture of the distal sesamoid bone under real-time supervision by the VetGate CAS-System. Care was taken to avoid penetration of the distal interphalangeal joint and the navicular bursa, as well as avoid damage of the articular cartilage. The placement within the bone was perfect for all 20 screws. The results for the 3.5 mm screws were good in all aspects, whereas the screw head of the 4.5 mm screws jeopardized the edge of the articular surface of the navicular bone in 8 out of 10 cases. The difference between the screw length determined by the VetGate system during the planning phase and the actually inserted screw length was significantly smaller than with the one experienced with the SurgiGATE 1.0 CAS-System. In conclusion standard 4.5mm screws are not feasible in Thoroughbreds and Warmblood horses of average size, mainly because of the screw head that is too large (8mm), whereas 3.5mm cortex screws serve the purpose very well. The use of the 4.0mm cortex screws is preferred because this screw has the same screw head diameter as the 3.5mm cortex screw and a thicker core diameter, which makes it more resistant towards implant breakage. The latter screw was not tested, but even 4.5 mm cortex screws could be inserted without damaging any vital structure. The VetGate CAS-System allows precise screw placement at this difficult location without damaging neighboring structures.

A biomechanical comparison of headless tapered variable pitch and AO cortical bone screws for fixation of a simulated slab fracture in equine third carpal bones

Veterinary Surgery, 2003

Objective-To compare mechanical properties and failure characteristics of 2 methods of fixation for repair of a transverse, midbody fracture of the proximal sesamoid bone (PSB): 4.5-mm AO cortical bone screw (AO) placed in lag fashion and 4/5-mm Acutrak s (AT) self-compressing screw. Study Design-An in vitro biomechanical evaluation of intact forelimb preparations and forelimb preparations with a simulated midbody PSB fracture stabilized by a bone screw. Sample Population-Sixteen paired and 8 unilateral cadaveric equine forelimbs. Methods-A midbody transverse osteotomy was created in the medial PSB of bilateral forelimbs of 8 equine cadavers. The osteotomized PSB in 1 forelimb from each cadaver was repaired with an AO screw. The osteotomized PSB in each contralateral limb was repaired with an AT screw. Eight unilateral intact control limbs were also studied. Mechanical properties were determined from axial compression, single cycle to failure, load-deformation curves. Failure characteristics were determined by evaluation of video images and radiographs. Results-No statistically significant differences were found between repair groups. Both AO and AT groups had significantly lower mechanical properties than intact limbs except for stiffness. Conclusion-AO and AT constructs were mechanically comparable when used to stabilize a simulated midbody fracture of the medial PSB. Both constructs were mechanically inferior to intact limbs. Clinical Relevance-The AT screw should be considered for clinical use because of the potential for less soft tissue impingement and superior biocompatibility compared with the stainless-steel AO screw. However, postoperative external coaptation is necessary to augment initial fracture stability for either fixation method, and to maintain a standing metacarpophalangeal joint dorsiflexion angle between 1501 and 1551.