Tibial Tuberosity Advancement for Treatment of CrCL Injury: Complications and Owner Satisfaction

Comparative anatomy of the proximal tibia in healthy Labrador Retrievers and Yorkshire Terriers

OBJECTIVES

1) To provide specific quantitative data of tibial conformation in Labrador Retrievers and Yorkshire Terriers; 2) To compare the tibial conformation of these two breeds; and 3) To compare these data with previously reported data.

METHODS

Mediolateral radiographs of the stifle were obtained from 30 consecutive Labrador Retrievers and 30 consecutive Yorkshire Terriers with an angle of extension of 135°. The tibial plateau angle (TPA), the angle between the tibial plateau and the patellar tendon (PTA), the Z angle, the distal tibial axis/proximal tibial axis angle (DPA), and the relative tibial tuberosity width (rTTW) were measured and compared among the two breeds.

RESULTS

The breed had a significant effect on all of the measured variables (p <0.01): Labrador Retrievers had a lower TPA (25 ± 3° compared to 30 ± 4°), a lower Z angle (58.8 ± 3.2° compared to 69.2 ± 4.5°), a lower DPA (4.5 ± 2.3° compared to 10.8 ± 4.3°), and a lower rTTW (0.74 ± 0.1 compared to 0.86 ± 0.1) than Yorkshire Terriers. The PTA was greater in Labrador Retrievers compared to Yorkshire Terriers (106.9 ± 3.9° compared to 103.7 ± 6.5°). Four correlations were found to be significant: the DPA angle was correlated with the TPA, the Z angle, and the rTTW. The TPA was also correlated with the Z angle.

CLINICAL SIGNIFICANCE

The variation in tibial conformation between breeds should be taken into account when studying the role of each measured parameter in the pathology of cruciate disease. When the relevance of each of the aforementioned measured parameters is better understood, it may help determine the most appropriate surgical treatment.

Clinical audit for the tibial tuberosity advancement procedure: establishing the learning curve and monitoring ongoing performance for the tibial tuberosity advancement procedure using the cumulative summation technique

OBJECTIVES

To quantitatively assess the learning curve for the tibial tuberosity advancement (TTA) procedure performed by a single surgeon using the cumulative summation (CUSUM) technique and to determine if surgeon performance remained under control (i.e. within specified quality boundaries) after the learning curve had been climbed.

STUDY DESIGN

Retrospective study.

ANIMALS

Dogs (n = 122) with cranial cruciate ligament deficient stifles (n = 167).

METHODS

Records of all dogs that had a TTA procedure performed by the same surgeon were reviewed. Cases were included if the following information was available: weight, breed, date of surgery, presence of partial or full cruciate rupture, meniscal pathology, occurrence and description of postoperative complications and treatment with a minimum of 12 months follow-up. Patients were excluded if they had a concurrent illness. Major complications were defined as those requiring revision surgery. The CUSUM technique was used to determine the time taken for the surgeon to reach a pre-defined level of competency and to monitor ongoing performance.

RESULTS

Major complications occurred in 15 out of 167 procedures (9%) within 12 months of TTA surgery. The complication rate decreased as surgical experience was gained with the technique, however the learning curve continued until the 22nd procedure. Thereafter, despite the target complication rate being re-set at a lower level, the surgeon's performance remained acceptable, i.e. within the revised quality boundary.

CLINICAL SIGNIFICANCE

The CUSUM technique was used for clinical audit, to determine the learning curve for the TTA procedure for a single surgeon, and to monitor ongoing performance. An experienced general practitioner had a learning curve of 22 procedures and complication rates were within the published ranges.