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Osteochondrosis of the Lateral Trochlear Ridge of the Talus
82
PA RT O N E
•
SURGICAL PROCEDURES FOR JOINT DISEASES
TA R S U S
Osteochondrosis of the Lateral Trochlear Ridge of the Talus
CHAPTER 27
INDICATIONS Candidates include dogs with persistent lameness and pain of the tarsus caused by osteochondrosis (OCD) that is not responsive to conservative management. OBJECTIVES • To improve limb function by removal of the entire OCD flap, curettage of the adjacent diseased cartilage, and forage to provide blood supply to the exposed subchondral bone via forage
bone curettes, pin chuck or high-speed wire driver, Kirschner wires or small Steinmann pin for forage PREPARATION AND POSITIONING Prepare the leg circumferentially from dorsal midline to the phalanges. Use a hanging leg preparation, with the dog in dorsal recumbency at the end of the surgery table to allow for maximal manipulation and visualization of the tarsus during surgery. PROCEDURE Dorsolateral Approach:2,4–6 Flex and extend the tarsus to
ANATOMIC CONSIDERATIONS 1–5 The tarsus is the third most common joint to be affected by OCD, with a reported incidence of 9%. Forty-four percent of the tarsal lesions are bilateral, although the typical presenting complaint of a dog with tarsal OCD is a unilateral lameness. Seventy-five percent of the OCD lesions of the tarsus occur on the plantar half of the medial trochlear ridge of the talus, and 25% occur on the lateral ridge. Because of the diversity of the lesion location, the surgical approach used to expose the lesion is as important as the surgical débridement and curettage. Both medial and lateral approaches have been described. A combined dorsomedial and plantaromedial approach exposes all but 4% of the medial trochlear ridge of the talus. Similarly, a combined dorsolateral and plantarolateral approach exposes the entire lateral trochlear ridge, with the central 20% of the lateral ridge being accessible from either individual approach.
accurately identify dorsal aspect of the lateral trochlear ridge via palpation. Center a curvilinear 4-cm to 5-cm incision over the trochlear ridge from the distal tibia and fibula to the distal intertarsal joint. Retract the skin and subcutaneous tissues with a Gelpi or Senn retractor to improve visualization of the tendons of the long digital extensor muscle, the cranial tibial muscle, the extensor hallucis longus muscle, the dorsal branch of the lateral saphenous vein, and the superficial peroneal nerve (Plate 27A). Retract these structures laterally. Retract the tendons of the peroneus longus, the lateral digital extensor, and the peroneus brevis in a plantar direction. Incise the deep fascia and adherent joint capsule longitudinally along the midline of the palpable portion of the lateral trochlear ridge, preserving the lateral collateral ligament of the tarsus. If necessary, extend the joint capsular incision into the periosteum at the junction of the distal tibia and fibula to increase the exposure of the trochlea (Plate 27B).
EQUIPMENT • Standard surgical pack, two medium or large Gelpi retractors (depending on the size of the dog), blunt Hohmann retractor,
Continued
PA RT O N E
•
SURGICAL PROCEDURES FOR JOINT DISEASES
TA R S U S
Osteochondrosis of the Lateral Trochlear Ridge of the Talus
CHAPTER 27
INDICATIONS Candidates include dogs with persistent lameness and pain of the tarsus caused by osteochondrosis (OCD) that is not responsive to conservative management. OBJECTIVES • To improve limb function by removal of the entire OCD flap, curettage of the adjacent diseased cartilage, and forage to provide blood supply to the exposed subchondral bone via forage
bone curettes, pin chuck or high-speed wire driver, Kirschner wires or small Steinmann pin for forage PREPARATION AND POSITIONING Prepare the leg circumferentially from dorsal midline to the phalanges. Use a hanging leg preparation, with the dog in dorsal recumbency at the end of the surgery table to allow for maximal manipulation and visualization of the tarsus during surgery. PROCEDURE Dorsolateral Approach:2,4–6 Flex and extend the tarsus to
ANATOMIC CONSIDERATIONS 1–5 The tarsus is the third most common joint to be affected by OCD, with a reported incidence of 9%. Forty-four percent of the tarsal lesions are bilateral, although the typical presenting complaint of a dog with tarsal OCD is a unilateral lameness. Seventy-five percent of the OCD lesions of the tarsus occur on the plantar half of the medial trochlear ridge of the talus, and 25% occur on the lateral ridge. Because of the diversity of the lesion location, the surgical approach used to expose the lesion is as important as the surgical débridement and curettage. Both medial and lateral approaches have been described. A combined dorsomedial and plantaromedial approach exposes all but 4% of the medial trochlear ridge of the talus. Similarly, a combined dorsolateral and plantarolateral approach exposes the entire lateral trochlear ridge, with the central 20% of the lateral ridge being accessible from either individual approach.
accurately identify dorsal aspect of the lateral trochlear ridge via palpation. Center a curvilinear 4-cm to 5-cm incision over the trochlear ridge from the distal tibia and fibula to the distal intertarsal joint. Retract the skin and subcutaneous tissues with a Gelpi or Senn retractor to improve visualization of the tendons of the long digital extensor muscle, the cranial tibial muscle, the extensor hallucis longus muscle, the dorsal branch of the lateral saphenous vein, and the superficial peroneal nerve (Plate 27A). Retract these structures laterally. Retract the tendons of the peroneus longus, the lateral digital extensor, and the peroneus brevis in a plantar direction. Incise the deep fascia and adherent joint capsule longitudinally along the midline of the palpable portion of the lateral trochlear ridge, preserving the lateral collateral ligament of the tarsus. If necessary, extend the joint capsular incision into the periosteum at the junction of the distal tibia and fibula to increase the exposure of the trochlea (Plate 27B).
EQUIPMENT • Standard surgical pack, two medium or large Gelpi retractors (depending on the size of the dog), blunt Hohmann retractor,
Continued