# Development of a Pericapsular Knee Desensitization Technique in Dogs: An Anatomical Cadaveric Study

## TL;DR

This study introduces a new technique for managing knee pain in dogs by targeting specific nerves without causing motor impairment, with ultrasound guidance showing better results.

## Contribution

The novel pericapsular knee desensitization (PKD) technique is introduced as a motor-sparing method for canine knee pain management.

## Key findings

- The ultrasound-guided PKD technique achieved a significantly higher success rate (96.7%) compared to the blind technique (73.3%).
- The medial articular nerve (MAN) was stained successfully in 100% of ultrasound-guided injections but only 50% of blind injections.
- Histological confirmation validated the anatomical findings, though posterior articular nerve (PAN) identification remained inconsistent.

## Abstract

Chronic pain from stifle joint diseases, such as osteoarthritis, is a common condition in dogs that often requires complex medical and surgical management. Conventional analgesic methods may be inadequate for controlling pain or may be associated with undesirable side effects, which may lead to diminished quality of life. Peripheral nerve blocks (i.e., femoral and sciatic nerve blocks) can be employed to relieve joint pain but are associated with unwanted motor impairment. This cadaveric study introduced the pericapsular knee desensitization (PKD) technique as a motor-sparing approach to selectively target the sensory articular branches innervating the canine knee joint. Two techniques—ultrasound-guided and blind injections—were developed and compared to evaluate the success rate of staining the articular nerves using a dye solution. The results showed that the ultrasound-guided technique had significantly greater accuracy in staining the target nerves. These findings support the feasibility of the PKD technique and provide anatomical and procedural guidance for future clinical studies aimed at improving pain management in dogs with stifle disease.

Regional anesthesia techniques targeting articular nerve branches offer promising avenues for managing articular pain. This study developed and compared the success rates of an ultrasound-guided versus a blind pericapsular knee desensitization (PKD) technique in canine cadavers. In Phase I, gross dissection and ultrasound evaluations were performed in eight limbs to characterize the anatomy of the medial (MAN), lateral (LAN), and posterior (PAN) articular branches of the saphenous, common fibular, and tibial nerves, respectively, and to identify suitable anatomical and ultrasonographic landmarks. In Phase II, ultrasound-guided and blind PKD injections of a dye solution were randomly performed in 10 cadavers (20 limbs), followed by dissection and histological assessment of staining accuracy. The ultrasound-guided technique achieved a significantly higher overall success rate (96.7%) than the blind technique (73.3%; p = 0.02). The MAN was successfully stained in 100% of ultrasound-guided and 50% of blind injections (p = 0.03), while the LAN and PAN were stained with high but comparable success. Parent nerve involvement was minimal for MAN and PAN but frequent for the common fibular nerve following LAN injections. Histological confirmation supported the anatomical findings, although PAN identification remained inconsistent. These results support the feasibility and increased precision of ultrasound-guided PKD, providing a foundation for further clinical evaluation.