Locking conical coupling plates in small animal orthopedics: A review

Conical coupling locking plates (CCP) have become an interesting alternative in veterinary orthopedics and traumatology. Available data in this regard, however, must be interpreted with caution, and several studies are still required to reach definitive conclusions on the clinical use of these implants. In this context, this review aims to discuss CCP applications and mechanical aspects in small animals and summarize in vivo, in vitro and ex vivo study results.

Pes varus correction in dachshunds with mini hybrid external skeletal fixators

AIM

To evaluate the clinical and radiographic outcome of pes varus deformity correction in dachshunds managed with acute medial opening wedge osteotomy of the distal tibia and stabilised with a mini hybrid external skeletal fixator (HESF).

METHODS

Surgical correction involved a transverse osteotomy over the premeasured location at the distal tibia and application of a IMEX mini HESF. All corrections were evaluated using centre of rotation and angulation methodology.

RESULTS

Medical records and radiographies of 20 dachshunds (28 pes varus corrections) were reviewed. All osteotomies healed and fixators were removed between 6 and 12 weeks. Lameness resolved in 18 dachshunds (90%) and significantly improved in two dachshunds (10%). Lateral patella luxation (LPL) was detected in 11/28 (39.2%) of the involved pelvic limbs, all of which resolved following pes varus correction. Mean frontal plane alignment (FPA) of the normal and abnormal tibiae were 12.3° valgus (range: 4°-18°) and 25° Varus (range: 16°-41°) respectively. Angular correction ranged between 30° and 50° (Mean: 39°) and the mean post-operative FPA was 13° valgus (range: 5°-21°).

CLINICAL SIGNIFICANCE

Pes varus deformity in dachshunds can be corrected by medial opening wedge osteotomy of the distal tibia stabilised by HESF. Single-session bilateral pes varus corrections can also be performed with minimal morbidity. LPL was commonly detected in dogs with pes varus deformity and all resolved spontaneously following pes varus correction alone.

Correction of pes varus deformity in a Miniature Dachshund by true spherical osteotomy with a dome saw blade

CASE DESCRIPTION

A 6-month-old male Miniature Dachshund was referred for examination and correction of a unilateral pes varus deformity.

CLINICAL FINDINGS

Clinical examination and diagnostic imaging revealed varus, procurvatum, and internal torsion of the distal aspect of the left tibia causing intermittent lameness.

TREATMENT AND OUTCOME

True spherical osteotomy performed with a dome-shaped saw allowed correction of the deformity in 3-D, and orthogonal internal plate fixation provided stabilization. No intraoperative or immediate postoperative complications developed. Outcome as judged by the clinician and the owners was satisfactory 2 weeks after surgery and excellent at each subsequent assessment. The patient remained free of clinical signs at the last follow-up 30 months after surgery.

CLINICAL RELEVANCE

To the authors' knowledge, this case represented the first time a true spherical osteotomy was used to correct a pes varus deformity in a canine patient.

Establishment of Normal Mechanical Tibial Joint Angles in Dachshunds

OBJECTIVE

 The aim of this study was to establish breed-standard mechanical tibial joint reference angles in the frontal plane in Dachshunds.

STUDY DESIGN

 Craniocaudal (n = 38) and mediolateral (n = 32) radiographs of normal tibiae from Dachshunds were retrospectively reviewed. The mechanical medial proximal, mechanical medial distal, mechanical caudal proximal and mechanical cranial distal tibial angles were measured on three occasions by two separate observers using previously established methodology. Interclass correlation coefficient was used to assess the reliability of radiographic measurements.

RESULTS

 The mean and standard deviation for mechanical medial proximal, mechanical medial distal, mechanical caudal proximal and mechanical cranial distal were 93.1 degrees ± 4.2, 97.5 degrees ± 3.9, 75.3 degrees ± 3.7 and 85.0 degrees ± 5.3 respectively. Intra-observer reliability was good to excellent for all measures, while inter-observer reliability was moderate to excellent in the frontal plane and poor to good in the sagittal plane. Dachshund-specific joint reference angles were similar to a range of previously reported non-chondrodystrophic breeds in the frontal plane but differed to most in the sagittal plane.

CONCLUSION

 Dachshund tibial joint reference angles are reported which can be used in surgical planning for correction of bilateral pes varus.