Chapter 83 - Management of Bursitis Flashcards
What is the primary function of bursae in the musculoskeletal system?
Bursae reduce frictional wear on muscles, tendons, or ligaments as they move against bony structures.
what type of tissue layer makes up the outer wall of a bursa?
The outer wall consists of a fibrous layer.
What is the role of the inner synovial membrane in a bursa?
The synovial membrane secretes synovial fluid and reduces friction by enabling smooth movement of tendons within the bursa.
Describe a tendon sheath and its relationship to bursae.
A tendon sheath is a type of bursa that completely envelops a tendon, acting as a lubricated wrap around it.
What is the source of the synovial fluid within bursae?
Synovial fluid is secreted by the synovial membrane of the bursa.
What characteristic does synovial fluid in bursae share with synovial fluid in joints?
It has similar lubricative properties.
What are congenital bursae, and where are they typically located?
Congenital bursae are naturally occurring bursae located in consistent anatomical locations, often subtendinous or subligamentous.
List ten examples of congenital bursae.
Navicular,
Atlantal
trochanteric bursae,
Bicipital, infraspinatus, atlantal and supraspinatus bursae, subtendinous bursa of the common and long digital extensor tendons over MCP/MTP joint and the subtendinous bursa of the long digital extensor at the proximoateral level of the tibia
What is the cause of acquired bursae formation?
Acquired or false bursae commnly form superficial to the extensor tendon at the dorsum of the fetlock in horses that jump fixed fences - these may become infected
How does a bursa differ when a large portion of a tendon must be protected?
The bursa completely ensheathes the tendon, acting as a tendon sheath.
What are the two main layers of a bursa wall?
An outer fibrous layer and an inner synovial membrane (parietal layer).
What does the inner synovial membrane cover within the bursa or sheath?
It covers the tendon or ligament surface inside the bursa or sheath (visceral layer).
What substance fills bursae and what produces it?
Synovial fluid, produced by the synovial membrane, fills bursae.
How does synovial fluid benefit tendon movement within a bursa?
It lubricates layers, reducing frictional damage to the tendon during movement.
What term is used to describe naturally occurring bursae?
True or congenital bursae.
Where are congenital bursae typically located?
They are typically found in consistent anatomical locations, either subtendinous or subligamentous.
What conditions lead to the formation of acquired bursae?
Persistent mechanical irritation or pressure over bony prominences.
What are alternative terms for acquired bursae?
False, functional, or facultative bursae.
Where do acquired bursae often develop in horses?
They may develop over the carpus, olecranon, and calcaneal tuberosity.
How does an acquired bursa begin to form?
It starts as a subcutaneous fluid accumulation due to tearing of subcutaneous tissue and hemorrhage.
What happens to an acquired bursa if trauma persists?
The fluid is not reabsorbed, leading to a seroma and eventual encapsulation by fibrous tissue.
What type of membrane eventually forms in an acquired bursa?
A synovial-like membrane.
What diagnostic techniques are often required to evaluate bursitis?
Diagnostic anesthesia, radiography, ultrasonography, contrast radiography, cytology, bacterial culture, and possibly tenoscopy or bursoscopy.
What is the typical cell count and protein level in normal synovial fluid?
Less than 500 nucleated cells/μL, less than 10% neutrophils, and less than 2.5 g/dL of total protein.
What nucleated cell count in synovial fluid indicates infection?
More than 30,000 cells/μL suggests infection, while over 100,000 cells/μL is pathognomonic for infection.
What is a typical protein concentration in septic synovial fluid?
Greater than 4 g/dL.
What treatment is generally attempted first for non-infected acquired bursae?
Conservative treatments, such as rest, anti-inflammatories, pressure bandaging, and removal of trauma sources.
When might surgical removal of an acquired bursa be necessary?
If the bursa is a well-established fibrous structure or there is evidence of synovial infection.
How is acute nonseptic bursitis typically managed?
With systemic, topical, and/or intrasynovial anti-inflammatory drugs, along with rest (2- months) and pressure bandaging.
What are key steps in treating infected bursae?
Wound debridement, synovial lavage and drainage, and administration of antimicrobials.
What minimally invasive procedure is recommended for bursitis treatment?
Bursoscopy, as it is both diagnostic and therapeutic.
Define a carpal hygroma.
A facultative subcutaneous bursa that develops over the dorsal carpus due to repetitive trauma or falls.
What behavior in horses can contribute to the formation of a carpal hygroma?
“Knee banging” on stable doors, drinking troughs, feeders, or fences.
How is a carpal hygroma typically presented?
As a nonpainful, fluctuant, uniform soft tissue swelling on the dorsal aspect of the carpus.
When might a carpal hygroma become painful?
If it becomes septic.
What imaging technique helps distinguish carpal hygroma from other carpal conditions?
Contrast radiography or ultrasonography.
What conservative treatment may be attempted for carpal hygroma?
Aspiration, corticosteroid (methylprednisolone acetate) or atropine 7 mg doseinjection, and firm bandaging (min 2w).
What surgical options are available for treating persistent carpal hygromas?
Surgical drainage ~(S-incision or elliptical) with a Penrose drain, synovial lining curettage, or complete surgical extirpation.
What type of bandage is recommended after surgical hygroma treatment?
A pressure bandage with a splint or sleeve cast to prevent carpal flexion and support healing.
Why is an S-shaped incision recommended during hygroma removal?
It provides optimal access for dissection of the fluid-filled sac from surrounding tissues.
What is the purpose of an Esmarch bandage in hygroma surgery?
To facilitate the removal of the hygroma by reducing blood flow in the area.
How long should bandaging be maintained post-hygroma surgery?
Bandaging should be continued for at least 2 weeks initially, with a total of 8 weeks of stall confinement for healing.
What complications can arise from bandaging a carpal hygroma post-surgery?
Risk of iatrogenic sepsis and pressure sores, especially over the accessory carpal bone.
How is infection of a carpal hygroma suspected clinically?
Increased skin temperature, localized pain upon pressure, and lameness.
What fluid analysis result is indicative of carpal hygroma infection?
Synovial fluid with elevated nucleated cell counts and protein levels.
What advice should owners receive about the cosmetic outcome of hygroma surgery?
A blemish is likely to remain despite successful healing.
What is olecranon bursitis commonly known as?
It is commonly known as “capped elbow” or “shoe boil.”
What causes olecranon bursitis in horses?
It is primarily caused by chronic trauma to the subcutaneous tissue over the point of the elbow.
How can repetitive trauma lead to olecranon bursitis in horses?
Repetitive trauma can occur when the horse’s limb hits the ground or if the hoof hits the olecranon while recumbent, causing tissue inflammation and bursitis.
Which horses are more prone to olecranon bursitis?
Gaited and Standardbred horses are more prone due to their movement patterns, which can cause the hind foot to strike the elbow.
Why should the skin incision be planned carefully during the treatment of olecranon bursitis?
To avoid placing the incision directly over the olecranon tuberosity, reducing the risk of re-injury and promoting better healing.
What type of suture material is commonly used for closing deep tissues in olecranon bursitis surgery?
Absorbable USP size 2/0 suture material is used.
Why are tension-reducing suture patterns used in olecranon bursitis treatment?
Tension-reducing patterns, like vertical mattress sutures, help minimize stress on the skin and reduce the risk of suture line rupture.
What post-surgical care is recommended to prevent excessive tension on a sutured olecranon bursa?
The horse is crosstied for 2-3 weeks to restrict movement and reduce tension at the surgical site.
How can recurrence of olecranon bursitis be prevented?
By avoiding repeated trauma to the elbow, such as using padding or protective boots.
What is a capped hock?
It is an acquired bursitis caused by chronic trauma to the subcutaneous tissue over the point of the hock (tarsus).
What are common causes of capped hock in horses?
Kicking against hard surfaces like walls or trailer gates.
How does initial swelling complicate the diagnosis of capped hock?
Acute injury can lead to extensive edema, which may mask the extent of the injury.
Why might a capped hock not be a concern unless it becomes septic?
Because a capped hock is generally seen as a cosmetic issue unless infection occurs, leading to lameness or other complications.
What conservative treatments can be used for a capped hock?
Ice, dimethyl sulfoxide, or diclofenac liposomal cream, combined with bandaging, are typically used.
How can corticosteroid injections help treat capped hock?
They reduce inflammation and can be effective in treating acute cases by resolving the bursa swelling.
What surgical approach is taken if conservative treatments for capped hock fail?
En bloc resection of the bursa may be performed to improve appearance and reduce swelling.
What precaution should owners be aware of regarding surgical treatment of capped hock?
Wound dehiscence is common, and some cosmetic blemishes may remain even after healing.
Why is a Robert Jones bandage applied after surgery on a capped hock?
It stabilizes the area and reduces motion at the tarsus, aiding in proper healing.
How can recurrence of capped hock be prevented?
Hock boots should be worn in stalls or trailers to protect the area from trauma.
What is false thoroughpin in horses?
It’s an effusion of the tarsal sheath resulting in a fluid-filled structure in the lower leg not connected to the tarsal sheath or calcaneal bursa.
What are possible causes of false thoroughpin?
Synoviocoele, synovial herniation, or organizing hematomas/seromas.
What might the presence of synovial membrane mesenchymal cells in a false thoroughpin cavity lead to?
Formation of synoviocytes that line and secrete fluid into the cavity, expanding the bursa.
How can imaging assist in diagnosing false thoroughpin?
Contrast radiography and ultrasonography can help identify the origin of the swelling.
Is false thoroughpin always associated with lameness?
No, it may or may not be a cause of lameness, so other potential causes must be ruled out.
Figure 83-1. A padded, donut-shaped boot that fits around the pastern prevents the foot or shoe from contacting the olecranon and developing a shoe boil.
Figure 83-2. After local anesthetic solution is injected subcutaneously around the base of the olecranon bursa (A), an elliptical, vertical skin incision is made over the lateral aspect of the mass (B). The mass is freed from skin and subcutaneous tissue using Mayo scissors to create a plane of dissection for removal of the mass en bloc (C). Care should be taken when planning the skin incision that when skin edges are reapposed they lie lateral to, not directly over, the olecranon tuberosity (D).
Figure 83-3. Example of a capped hock.
figure 83-4 - A large, spherical, biaxial swelling (false thoroughpin) is present in the caudodistal aspect of the crus between the tibia and the tendons of insertion of the gastrocnemius and the superficial digital flexor tendon, just proximal to the calcaneal tuberosity.
Figure 83-5. Clinical signs of supraspinous bursitis include singular or multiple draining tracts of the withers.
Figure 83-7. Extension of the shoulder joint, as described by elicits signs of resentment in horses with bicipital bursitis.
Figure 83-8. Fluid distension of the bursa is indicated by an increase in space between the tendon and the humerus and outpouching of the lateral and medial recesses of the bursa on either side of the tendon. (A) Normal left bicipital bursa; (B and C) left bicipital bursa containing excessive fluid (arrows). Note that the lateral head of the bicipital tendon has a larger cross-sectional area than the medial head. The lateral lobe of the tendon is “teardrop”-shaped and the medial lobe has an elongated rectangular shape. *, Lateral lobe of the bicipital tendon.
Figure 83-11. Sagittal magnetic resonance short tau inversion recovery (STIR) image of the left foot of a horse with navicular bursitis. The proximolateral pouch of the navicular bursa is severely distended with synovial fluid causing accumulation of hyperintense (white) fluid signal.
Figure 83-12. A contrast bursogram of the navicular bursa results in a flow of contrast medium along the penetrating solar wound that has resulted in a double tract, one entering the navicular bursa and one entering the distal interphalangeal joint. Looking for leakage after distending the navicular bursa with contrast medium from a site distant to the wound is preferable to performing direct fistulography to determine if the bursa has been breached.
Figure 83-13. Position of arthroscope for treatment of septic navicular bursitis following a penetrating wound of the lateral sulcus of the frog.
Figure 83-14. The bursa of the long digital extensor tendon (arrow) can act as a reservoir of sequestered bacteria and inflammatory products in foals with sepsis of the lateral compartment of the femorotibial joint.
Figure 83-15. The calcaneal bursae include the subcutaneous calcaneal bursa (A), the intertendinous calcaneal bursa (B), and the gastrocnemius calcaneal bursa (C). The intertendinous and gastrocnemius calcaneal bursae always communicate and can be referred to collectively as the subtendinous calcaneal bursa.
