angels presenting chronic patellar luxation in cattle.by pavul

PATELLAR LUXATION

Prepared by Dr.Pavulraj.S

M.V.Sc., (Veterinary Pathologist) Research fellow

National Research Centre of Equines, India

2/15/2015 Dr. Pavulraj. S, M.V.Sc., Veterinary

Pathologist, Research fellow, NRCE, India

Definition Impaired patellar function characterized by

jerky movements during flexion to complete immobilization of the joints.

• Animal fixes its ‘limb in extension’ while the patella glides up over the trochlea to its maximum height on the articular surface.

• Recurrent or permanent upward fixation of the patella.

• More common in draught purpose animals.

Patellar luxation in cattle



• It is non-inflammatory functional disorders of the femoropatellar articulation in cattle.

• When one limb involved, animal moved forward by swinging the rigid affected limb outward and forward.



• Patella – large sesamoid bone.

• Connected to femur by collateral ligaments and to the cranial tibial tuberosity by patellar ligaments.

• Patellar ligaments are medial, middle and lateral.

Patella



• Laxity of the patellar ligaments predisposed the animal to upward fixation of the patella.

• Relaxed ligaments allow the patella to glide freely on the articular surface of the trochlea.

• If limb is over extended, the patellar apex may get jammed between the trochlear ridges by hooking the medial fibrocartilage over the medial trochlear ridge



Clinical signs

• Posture of the animal is normal at rest but, every attempt to move the animal backwards is resisted.

• Animal shows jerky flexion during movements or drags the affected limbs with flexed pastern.

• Affected limb is brought forward with a jerky flexion on every step.

• Sitting - affected limb stretched.



A, Craniocaudal view; note lateral position of the patella (arrow). B, Lateral view; patella (arrow) is not seen dorsal to the trochlea groove but overlaps the trochlea because of its lateral position.



• The subcutaneous division of the medial patellar ligament is the common surgical treatment to correct upward fixation of the patella.

• Bassi’s method

Open method

tab method

Clinicians prefer the surgery in the standing animal, In lactating animal a lateral recumbency is preferred.

Treatment



Objective

• The patella gets fixed above the trochlea of femur and the medial straight ligament is tightly overstretched behind the medial trochlear ridge, which prevents the downward return of the patella.

• The object of the operation is to mechanically bring down the patella by cutting the tensed medial ligament.



• The animal is cast with the affected limb lower most and the other three limbs are tied together. The affected limb is drawn slightly backward in such a way that the stifle joint is flexed completely.

• The site is prepared for aseptic surgery and infiltrated with local anesthetic solution .

Casting



• The index finger is moved upward along the cranial border of the tibia till the cranial tibial tuberosity is reached

• The cranial ligament is traced as a broadest and thickest among the three partellar ligaments .

• The finger is then moved over the medial ligament which is felt as a prominent cord .

Locating the medial patellar ligament



• A small incision is made in the skin directly over the medial ligament. The index finger is passed into the wound and the skin separated from the fascia all around the site.

• The fascia is dissected to expose white glistening medial patellar ligament . The ligament is exteriorized by passing a curved scissors.

Open method



• The ligament is then sectioned near its insertion using a knife . The cutaneous wound is sutured with one or two interrupted sutures which are removed on seventh or eighth postoperative day.

• Cessation of crunching sound and immediate relief of the characteristic jerky flexions during progression are indications of a successful medial patellar desmotomy.



• A stab incision is made into the skin with a B.P. blade immediately in front of the medial tibial tuberosity .

• Though this incision,the abscess knife, curved probe pointed knife or Hey groove knife is passed flat wise between the middle and medial patellar ligaments and the sharp edge of the instrument is directed towards the ligaments.

Closed method



• The ligament is then transected by withdrawing the knife towards the operator.

• A small quantity of tincture iodine is instilled into the wound which is left unsutured.

• A piece of the ligaments is removed to prevent the reunion of cut ends of the ligaments.

• Cessation of crunching sound and immediate relief of the characteristic jerky flexions during progression are indications of a successful medial patellar desmotomy.



Patellar luxation in dogs

• Displacement of patellar from the trochlear sulcus

• Slipped knee cap

• Smaller, toy- breeds affected

• Intermittent weight bearing lameness. Hold the leg in a flexed position for one to two step.

Medial patellar Luxation



Grading

• Grade1. Spontaneous luxation of the patellar during normal joint, flexion and extension other wise normal

• Grade 2. Patella luxate with flexion of the stifle joint. It

remain luxated

• Grade 3. Patella remain luxated, but manually reduced with stifle extension, there will be medial displacement of quadriceps muscle

• Grade 4. Patella in permanently luxated. Cannot manually repositioned. Medial displacement of quadriceps muscle.



Physical examination

• Skipping while walking

• Non – weight being limping

• Walk with near quarter in a crouched position

Radiograph Cranio-caudal and medial – to – lateral

radiograph. Patella displaced medially.



Surgical treatment

• Positioning: lateral or dorsal recumbency

• Place polyester suture through femoral fabellar ligament and lateral parapateller fibrocartilage. Next place series of imbrication suture though the fibrous joint capsule and lateral edge of the patella tendon.

• Tie the femoral – fabellar suture and imbrication suture.

Lateral reinforcement



Deepening of the trochlear groove

• It deepens the trochlear groove to restrain the patella and maintain the integrity of patella femoral articulation.

• Fine-toothed hand-held saw used to cut the trochlea. Cut in to the articular cartilage of the trochlea, making a diamond shaped out line.

• The width of the cut is sufficient at its midpoint to accommodate the width of the patella. Close the arthrotomy as lateral approach to stifle joint.

Trochlear wedge recession



Trochlear resection

• Is a method of deepening the trochlear groove through removal of articular cartilage and subchondral cancellous bone.



Lateral patellar luxation

• It is an intermittent or permanent displacement of the patella from the trochlear sulcus.

• More in large breeds of dog

• Intermittent, weight – bearing lameness

• Animal holds the leg in a flexed position for one or two step.

Diagnosis



• Skipping when walking

• Walk with the near quarters in crouched position (due to inability to extent the stifle joints fully )

Craniocaudal and medial to lateral radiograph – patella displaced laterally.

Physical examination

Radiograph



Surgical treatment

Positioning

Animal in lateral recumbency with affected leg up.

Methods

• Lateral reinforcement

• Trochlear wedge resection

• Trochlear resection.

Prognosis – fair – 52%

2/15/2015

Dr. Pavulraj. S, M.V.Sc., Veterinary Pathologist, Research fellow, NRCE, India

References

• Small Animal Surgery- Theresa Welch Fossum

• Bovine Surgery and Lameness, Second Edition- A. David Weaver

• Ruminant Surgery - R.P.S.Tyagi.Jit Singh, Fourth edition



TARA

JESSY



angels presenting chronic patellar luxation in cattle.by pavul

Science

patellar ligaments

india objective

india laxity

medial patellar ligament

lateral view patella

patellar luxation

patellar apex

standing animal