Long-term outcome of an intra-articular allograft technique for treatment of spontaneous cranial cruciate ligament rupture in the dog.

OBJECTIVE: To determine the 12-month outcome in dogs with spontaneous cranial cruciate ligament (CCL) rupture after repair with an intra-articular decellularized allograft. STUDY DESIGN: Prospective pilot case series. ANIMALS: Ten client-owned dogs with unilateral CCL rupture. METHODS: An intra-articular, decellularized, deep digital flexor tendon allograft was secured in the stifle with a femoral cross pin and tibial spiked washers and screws. An interference screw was placed in the tibial tunnel. Dogs were evaluated with an owner questionnaire, radiographs, and force platform gait analysis before and 2, 6, and 12 months after surgery. RESULTS: Owners reported improvement in level of pain and mobility throughout the study, especially over the first 6 months. Peak vertical force and vertical impulse improved across all time points. Ground reaction force asymmetry index for peak vertical force and vertical impulse at 12 months showed 3 dogs within a normal index (<6%), 4 dogs as nonvisibly lame (6-20%), and 3 dogs as visibly lame (≥20%). For most dogs, osteoarthritis scoring did not change over the 12-month period and some femoral-tibial translation was detected on standing horizontal beam radiographs. CONCLUSION: Intra-articular repair using a decellularized allograft can provide functional clinical outcomes in dogs with CCL disease. A better understanding of long-term engraftment after this procedure is needed.

Clinical results of single-session bilateral medial patellar luxation repair in 26 small breed dogs.

Medical records of 26 small breed dogs treated with single-session bilateral medial patellar luxation repair were reviewed. Excluding dogs with complications associated with cranial cruciate ligament disease, 20/21 dogs with long-term follow-up achieved a complete or acceptable clinical recovery. The complication rate was not increased compared to that previously reported for unilateral patellar luxation repair.

Résultats cliniques de la réparation d'une luxation patellaire médiale bilatérale en une seule séance chez 26 chiens de petites races. Les dossiers médicaux de 26 chiens de petites races ayant subi la réparation d'une luxation patellaire médiale bilatérale en une seule séance ont été évalués. En excluant les chiens avec des complications associées à la maladie du ligament croisé antérieur, un rétablissement clinique complet ou acceptable a été observé chez 20/21 chiens lors d'un suivi à long terme. Le taux de complication n'a pas augmenté comparativement aux résultats antérieurement publiés pour la réparation d'une luxation patellaire unilatérale.(Traduit par Isabelle Vallières).

Biochemical, histologic, and biomechanical characterization of native and decellularized flexor tendon specimens harvested from the pelvic limbs of orthopedically normal dogs.

OBJECTIVE: To evaluate the biochemical and biomechanical properties of native and decellularized superficial digital flexor tendons (SDFTs) and deep digital flexor tendons (DDFTs) harvested from the pelvic limbs of orthopedically normal dogs. SAMPLE: 22 commercially supplied tendon specimens (10 SDFT and 12 DDFT) harvested from the pelvic limbs of 13 canine cadavers. PROCEDURES: DNA, glycosaminoglycan, collagen, and protein content were measured to biochemically compare native and decellularized SDFT and DDFT specimens. Mechanical testing was performed on 4 groups consisting of native tendons (5 SDFTs and 6 DDFTs) and decellularized tendons (5 SDFTs and 6 DDFTs). All tendons were preconditioned, and tension was applied to failure at 0.5 mm/s. Failure mode was video recorded for each tendon. Load-deformation and stress-strain curves were generated; calculations were performed to determine the Young modulus and stiffness. Biochemical and biomechanical data were statistically compared by use of the Wilcoxon rank sum test. RESULTS: Decellularized SDFT and DDFT specimens had significantly less DNA content than did native tendons. No significant differences were identified between native and decellularized specimens with respect to glycosaminoglycan, collagen, or protein content. Biomechanical comparison yielded no significant intra- or intergroup differences. All DDFT constructs failed at the tendon-clamp interface, whereas nearly half (4/10) of the SDFT constructs failed at midsubstance. CONCLUSIONS AND CLINICAL RELEVANCE: Decellularized commercial canine SDFT and DDFT specimens had similar biomechanical properties, compared with each other and with native tendons. The decellularization process significantly decreased DNA content while minimizing loss of extracellular matrix components. Decellularized canine flexor tendons may provide suitable, biocompatible graft scaffolds for bioengineering applications such as tendon or ligament repair.

Mechanical strength of four allograft fixation techniques for ruptured cranial cruciate ligament repair in dogs.

OBJECTIVE: To test ex vivo mechanical properties of 4 allograft fixation techniques for cranial cruciate ligament (CCL) replacement. SAMPLE: 30 stifle joints from canine cadavers. PROCEDURES: CCL-deficient stifle joints repaired by 1 of 4 techniques (n = 6/group) and CCL-intact stifle joints (control group; 6) were mechanically tested. Three repair techniques involved a patella-patella ligament segment (PPL) allograft: a tibial and femoral interference screw (PPL-2S), a femoral interference screw and the patella seated in a tapering bone tunnel in the tibia (PPL-1S), or addition of a suture and a bone anchor to the PPL-1S (PPL-SL). The fourth technique involved a deep digital flexor tendon (DDFT) allograft secured with transverse femoral fixation and stabilized with a tibial interference screw and 2 spiked washers on the tibia (DDFT-TF). The tibia was axially loaded at a joint angle of 135°. Loads to induce 3, 5, and 10 mm of femoral-tibia translation; stiffness; and load at ultimate failure with the corresponding displacement were calculated. Group means were compared with a multivariate ANOVA. RESULTS: Mean ± SD load for the intact (control) CCL was 520.0 ± 51.3 N and did not differ significantly from the load needed to induce 3 mm of femoral-tibial translation for fixation techniques PPL-SL (422.4 ± 46.3 N) and DDFT-TF (654.2 ± 117.7 N). Results for the DDFT-TF were similar to those of the intact CCL for all outcome measures. CONCLUSIONS AND CLINICAL RELEVANCE: The DDFT-TF yielded mechanical properties similar to those of intact CCLs and may be a viable technique to test in vivo.