Biomechanical evaluation of the influence of an intramedullary pin on the stability of a feline ilial fracture model stabilized with a bone plate.

OBJECTIVE: To compare the mechanical properties of feline ilial fractures stabilized with either a plate (P), or a plate and IM pin (P + P). STUDY DESIGN: Mechanical study. SAMPLE POPULATION: Cadaveric cat pelvii (n = 10). METHODS: Feline ilial fractures (n = 20) stabilized with either P or P + P were subjected to 100 nondestructive load cycles, then loaded to failure. Deformation after cycling, yield load and displacement, stiffness and load at 2 mm of displacement were compared between groups. RESULTS: There were no significant differences between groups for any of the parameters. Variability of data was much larger for the P + P group. CONCLUSIONS: No biomechanical advantage was demonstrated. The P + P constructs were not significantly stronger than plates alone in this acutely loaded cadaveric model.

Use of an extracapsular stabilization technique to repair cruciate ligament ruptures in two avian species.

An extracapsular stabilization technique was used to repair cruciate ligament ruptures in a trumpeter hornbill (Bycanistes bucinator) and an African grey parrot (Psittacus erithacus). The hornbill demonstrated cranial drawer motion and severe rotational instability of the stifle from ruptures of the cranial and caudal cruciate ligaments and stifle joint capsule. The luxation was reduced, and the fibula was cranially transposed, in relation to the tibiotarsus, and anchored with 2 positive profile threaded acrylic pins. A lateral extracapsular stabilization was then performed. The African grey parrot had a traumatic stifle luxation, and an open reduction and a lateral extracapsular stabilization were performed. Both birds regained function of the affected leg by 1 month after surgery. Extracapsular stabilization allows motion of the stifle joint to be maintained during the postoperative recovery period, an advantage over rigid stabilization. Maintaining motion in the stifle joint facilitates physical therapy and can aid in full recovery after avian stifle injuries.

Biomechanical comparison of dual interlocking single loop and double loop tension band techniques to the classic AO tension band technique for repair of olecranon osteotomies in dogs.

OBJECTIVE: To compare olecranon fragment stability between the classic tension band wire (TBW) technique with the wire placed either in contact with (Arbeitsgemeinschaft für Osteosynthesefragen [AO]), or not in contact with, a Kirschner (K)-wire (AOW) to 2 novel wire patterns: a dual interlocking single loop (DISL) and a double loop (DL). STUDY DESIGN: Ex vivo mechanical evaluation on cadaveric bones. SAMPLE POPULATION: Canine ulnae (n=40) with olecranon osteotomies repaired with 2 K-wires and 1 of 4 TBW constructs. METHODS: Single load to failure applied through the triceps tendon. Displacement was measured from images captured from digital video. Techniques were compared based on the load resisted when the olecranon fragment was displaced 0.5, 1, and 2 mm. RESULTS: At 0.5 mm of displacement, the DISL construct resisted more load than the AOW construct (505 versus 350 N; P=.05). AO and DL constructs resisted an intermediate load (345 and 330 N, respectively). There was no significant difference between groups at 1 mm of displacement. At 2 mm of displacement, DL (785 N) resisted more load than AO (522 N, P=.01) and AOW (492 N, P=.03) groups. CONCLUSIONS: DISL constructs provided similar stability to classic TBW constructs whereas DL constructs were more stable at higher loads. CLINICAL RELEVANCE: The DL construct is easy to perform, less bulky, and provides comparable fragment stability to standard TBW techniques at functional loads. Surgical method is important for optimal performance of all TBW constructs.

Wound healing in the veterinary rehabilitation patient.

Wound healing is a biologically complex cascade of predictable overlap-ping events and is a natural restorative response to tissue injury. The biologic process for wound healing is the same for all wounds, although the specific mechanisms may vary. This article reviews the wound heal-ing process, discussing factors that may delay normal healing progression and potential modalities and treatments to aid healing.