Ex vivo biomechanical evaluation of extracapsular stabilization with quasi-isometric points in canine cranial cruciate ligament-deficient stifles

BACKGROUND

Cranial cruciate ligament (CCL) disease is one of the most common causes of lameness in dogs. The extracapsular stabilization (ECS) utilizing bone anchors and monofilament nylon leader was an alternative treatment for CCL-deficient (CCLD) dogs. However, the biomechanical response of the canine stifle to such a surgical repair strategy in conjunction with the use of recently reported quasi-isometric anchoring points remains unclear. The objectives of the study were to evaluate the mobility and stability of CCL-intact, CCLD, and CCLD stifles repaired with ECS at two different pairs of quasi-isometric points (quasi-IPs).

METHODS

Twelve stifle specimens from 7 dogs underwent mobility and stability tests under 4 different conditions, namely, CCL-intact, CCLD, and ECS-repaired at 2 different pairs of quasi-IPs (referred to as ECS-IP1 and ECS-IP2). The mobility tests evaluated 6 degrees-of-freedom stifle kinematics during flexion and extension. The stability tests involved cranial drawer and tibial internal rotation (IR) tests at various stifle opening angles and quantifying the cranial tibial translation (CTT) and tibial IR angles under constantly applied loadings.

RESULTS

The ECS repaired at quasi-IPs was shown to restore cranial instability of the stifles with averaged CTT magnitudes < 1.4 mm. During the tibial IR test, the ECS treatments resulted in significantly less tibial IR compared to those in intact CCL stifles. The mobility tests showed similar results.

CONCLUSION

The 2 chosen pairs of quasi-IPs were shown to effectively correct the excessive CTT caused by CCLD stifles, whereas the excessive tibial external rotation in comparison to those of intact stifles should be considered for its subsequent influence on joint alignment and the contact pressure applied to the stifle joint.

Influence of radiographic examination findings on recommendations made during routine clinical re-evaluation of dogs with uncomplicated tibial plateau leveling osteotomy

OBJECTIVE

To determine the influence of follow-up radiographic examination on recommendations made during routine clinical re-evaluation of dogs that had undergone uncomplicated tibial plateau leveling osteotomy (TPLO).

STUDY DESIGN

Retrospective multi-institutional case series.

ANIMALS

Client-owned dogs (N = 1010) that underwent uncomplicated TPLO.

METHODS

Records from 11 institutions were searched for dogs that had been treated with unilateral TPLO and had no history of postoperative complications before their routine follow-up examination. The frequency of change in further clinical recommendations resulting from client- or clinician-voiced concerns or radiographic abnormalities was investigated.

RESULTS

Follow-up evaluation was performed at a median of 6 (range, 4-15) weeks after TPLO. Radiographic examination findings contributed to a change in recommendations in 4.15% (38/915) of dogs presented without client concerns and without abnormalities at orthopedic examination. Abnormal radiographic findings alone influenced the management of 3.76% (38/1010) of dogs. An association was detected between clinical features and radiological findings leading to a change in recommendations (P < .0001). Administration of analgesia at the time of follow-up was associated with radiographic abnormalities (P = .017) and change in postoperative plans (P = .0007).

CONCLUSION

Radiographic examination findings at follow-up did not influence the management of most dogs with uncomplicated TPLO.

CLINICAL SIGNIFICANCE

Radiographic examination findings are unlikely to influence the treatment of dogs that seem to be recovering uneventfully from an uncomplicated TPLO without concerns from clients, analgesia, or abnormal findings on thorough orthopedic examination by a surgical specialist, at the time of the planned clinical re-evaluation.

Evaluation of cranial tibial translation in dogs: Diagnostic accuracy of radiographic method using a simple device

A hand-made, radiolucent, custom-designed device having a mobile and a non-mobile platforms was used to objectively quantify the in vivo cranial tibial translation, in order to assess the functional status of cranial-cruciate-ligament (CrCL) in dogs. The hypothesis was that changes in CrCL integrity would result in detectable changes in tibial translation. To validate the diagnostic method, data from injured (PA, n = 32), contralateral (CO, n = 32) and healthy stifles (HE, n = 32) were compared. Normalized tibial translation (Δ_N) of each stifle was measured in medio-lateral radiographic projection obtained before and during standard thrust force application, in PA (43.59±12.97%), CO (20.32±6.69%) and HE (12.22±3.77%). Comparing PA with HE and CO (Δ_N cut-off value: 29.73%), diagnosis could be issued with very high probability. Comparing HE with CO (Δ_N cut-off value: 14.80%), high performance was obtained. The translator device could be a useful tool to objectively quantify the in vivo tibial translation in dogs with CrCL rupture, before surgery and during post-operatory follow-up.