History and presenting complaint

Most horses with olecranon fractures have a history of a direct kick from another horse or are injuries sustained when falling. Horses typically present with an acute onset, severe lameness and, due to a lack of functional triceps, may have a dropped elbow appearance with an inability to extend the carpus.⁶ (Fig. 18.1)

Physical examination

Clinical signs in horses with olecranon fractures may show a dropped elbow appearance, which is due to the lack of effective triceps function as this muscle attachment is to the fractured olecranon.⁶ This dropped elbow appearance occurs with displaced or unstable fractures. These horses may display swelling around or near the point of the elbow and may be sensitive to palpation in this area depending upon the degree and configuration of the fracture.³ Contrary to other horses with a dropped elbow appearance, such as those with complete humeral fractures or radial neuropathy, these horses may be able to bear weight on the limb (minimally displaced fractures). An open wound may also accompany these fractures, which may communicate with the elbow joint.

Special examination

Latero-medial and cranio-caudal radiographic projections are recommended to assess the fracture configuration and to determine if there is an articular component. Once the fracture is identified, it can be classified. There have been different grading schemes reported, but the authors use the one described below.⁷

Laboratory examination

Synovial fluid analysis in fractures with an articular component may demonstrate non-septic inflammation; whereas, open fractures may demonstrate septic inflammation depending upon the time of fluid collection. Fluid analysis is not typically helpful aside from ruling out septic inflammation.

Diagnostic confirmation

Radiography is the most common way to confirm the diagnosis (Fig. 18.2). Nuclear scintigraphy may be useful in simple non-displaced fractures that are difficult to visualize radiographically. Computed tomography would be more useful for surgical planning; however, this is still not an easily accessible area to image in the adult horse due to the current gantry size in most available scanners.

Therapeutic aims

The main therapeutic goal is to restore the articular margin as quickly as possible to prevent secondary osteoarthritis. Infection in open fractures should be addressed. Fractures that are displaced, articular and disrupt the triceps apparatus warrant internal fixation.

Therapy

First aid to stabilize the fracture is indicated in cases where the horse is unable to bear weight on the limb. The leg should be bandaged and a full limb caudal splint from elbow to fetlock should be applied to lock the carpus in extension. Local wounds in open fractures should be clipped of hair and cleaned. Many of these horses become more comfortable with the splint applied. Displaced and articular fractures warrant internal fixation to restore the joint surface. Locking or Dynamic Compression Plates are typically used to repair these fractures.8–10 Articular fractures that are not displaced have the potential to be treated conservatively. Non-displaced and non-articular fractures are typically treated conservatively with rest, but should frequently be re-evaluated to ensure the fracture has not become displaced.

Prognosis

A favorable prognosis can be achieved with most olecranon fractures. Non-displaced and non-articular fractures are the most amenable to conservative management. Type 5 and minimally displaced type 3 fractures can be treated conservatively successfully; whereas, other fracture configurations will typically require surgical treatment.11–14

History and presenting complaint

Horses typically present following a history of direct trauma or acute, severe lameness. The severity of lameness will depend upon the degree of displacement of the fracture.3,5,15 Complete, displaced fractures will result in a non-weight bearing lameness. A wound over the radius may be present and is commonly on the medial aspect of the limb due to decreased soft tissue coverage in this area.

Physical examination

Clinical signs in horses with radial fractures will depend upon the degree of displacement and can range from a walking lameness to non-weight bearing. In horses with displaced fractures, attempts at weight bearing usually result in deviation of the limb and many will stand with their carpus and fetlock joints flexed and the toe dragging. Most horses will have significant swelling over the site of fracture. Affected horses may also have a visible deviation in the limb or palpable crepitance. Since there is minimal soft tissue covering over the radius many of these fractures have an associated wound medially. Non-displaced or minimally displaced fractures can be harder to diagnose as horses will be severely lame, but palpable swelling, crepitus, or a wound may not be present to point the examiner to the radius.¹⁵

Special examination

Visual assessment of complete, displaced radial fractures is usually diagnostic; however, radiography is extremely helpful in determining the degree of comminution and the configuration of the fracture. Nuclear scintigraphy is helpful in cases of non-displaced or stress fractures of the radius.³

Diagnostic confirmation

Standard latero-medial and cranio-caudal radiographic views are the minimum required to evaluate the fracture, but oblique views and stress views may provide valuable information. Stress fractures or incomplete radial fractures can be diagnosed with radiography or nuclear scintigraphy. Trauma to the radius can also result in sequestration or osteomyelitis, which can be suspected with radiography and/or scintigraphy.¹⁶ Computed tomography may be beneficial to fully characterize the fracture in foals with radial fractures, but the gantry size in most computed tomography scanners does not typically allow imaging of this area in the adult patient. Furthermore, since scanning requires general anesthesia substantial risk is encountered during anesthetic recovery unless the fracture is repaired with internal fixation. High-resolution ultrasound may be beneficial in locating breaks within the periosteum; however, the methods mentioned above are preferred.

Therapeutic aims

The main therapeutic goal is to return stability to the radius. External coaptation and local wound care in open fractures is crucial to prevent further soft tissue trauma to the area and to prevent the fracture from propagating.

Therapy

First aid therapy in displaced open fractures is to clip the open wound and thoroughly clean the area with dilute saline solution. Foreign material should be removed from the area and the leg should be bandaged to prevent further contamination. This is with a heavy bandage with a lateral splint that extends from the ground up to the withers and a caudal splint that extends from the ground to the olecranon.

In horses with non-displaced or incomplete fractures, conservative therapy is recommended. This entails strict stall confinement and cross-ties to prevent the horse from laying down. Horses that have incomplete fractures that are not cross tied have the potential of causing further displacement or propagation of the fracture due to the stresses placed on the limb when attempting to stand. This stall confinement is recommended for 3–4 months prior to attempting short handwalks with periodic radiographic assessment of fracture healing.³ In cases that are not amenable to conservative management (displaced fractures), internal fixation with bone plates is required. Involvement of the fracture line into the elbow joint or a wound communicating with the joint must be ruled out to treat the horse conservatively.¹⁶ Sequestration requires removal of the fragment. Osteomyelitis requires long-term antimicrobial therapy.

Prognosis

The prognosis of adult horses with complete radial fractures is poor. Although there have been successful attempts at internal fixation, oftentimes the internal fixation cannot withstand the forces applied to the radius. Although stronger locking plates are now available (5.5 broad), these can still be challenging fractures to internally stabilize due to secondary complications such as contralateral limb laminitis or implant infection. Conservatively treated horses with non-displaced fractures that strictly adhere to the stall confinement can have a good prognosis.¹⁷ Horses with sequestration without fracture have a good prognosis and those with osteomyelitis can have a good prognosis following surgical debridement and long-term antimicrobial therapy.¹⁶

Epidemiology

Radial fractures in adult horses are relatively uncommon.

Prevention

Aside from avoiding the traumatic event there are no strategies to prevent radial fractures.

History and presenting complaint

Horses with advanced sepsis in the elbow joint have a severe (grade 4 or 5) lameness, which is due to joint distention secondary to the inflammation. Acute injuries or those with open wounds into the joint will typically have a less severe lameness until the joint distention occurs. Horses that have had a recent injection into the elbow that become acutely lame should be considered septic until proven otherwise.

Physical examination

Horses with septic arthritis will have a severe lameness that may be variable depending upon the degree of infection. The limb may be warm to the touch and attempts at flexing or extending the elbow joint will typically result in pain. Palpable effusion within the elbow joint is possible; although unless severe it will be difficult to palpate.

Special examination

Radiographic examination can be beneficial in these cases to evaluate for osseous damage, secondary arthritic changes or osteomyelitis. Radiography is also recommended to rule out other causes of lameness in this area. Progressive radiographic arthritic changes are typically not encountered unless the cases are chronic.

Laboratory examination

Synovial fluid analysis is extremely beneficial in cases of septic arthritis. Nucleated cell counts will be greater than 2000 cells/uL and are typically greater than 10 000 cells/uL with a neutrophil differential of >90% with or without degeneration. Synovial fluid culture and sensitivity can be performed, but is frequently unrewarding.

Diagnostic confirmation

Synovial fluid analysis is the most beneficial test to evaluate for septic arthritis; however, radiography can also help rule out other causes of severe lameness in this area such as articular olecranon fractures.

Therapeutic aims

The main therapeutic goal is to remove the source of infection and fibrin within the joint and to prevent degeneration of cartilage and subsequent osteoarthritis.

Therapy

Removal of inflammatory cells and fibrin can be accomplished with lavage of the elbow joint under general anesthesia. Through-and-through needle lavage can remove the source of infection and inflammatory mediators; however, advanced cases or those with gross contamination are better treated with arthroscopic lavage. Arthroscopic lavage not only provides a larger bore flush and facilitates removal of fibrin, but also provides a diagnostic view of the elbow joint. The horse should also be placed on systemic antibiotics and anti-inflammatory medications post-operatively.5,18

Prevention

Aside from preventing the trauma to the area and good husbandry in neonates, there are no prevention strategies. Strict aseptic technique should be adhered to for joint injections.

History and presenting complaint

The horse typically presents for a unilateral forelimb lameness that varies from mild to moderate.3,5

Physical examination

Horses with elbow arthritis have variable grades of forelimb lameness. Unless a wound is present over the elbow, these horses are clinically difficult to differentiate from other causes of forelimb lameness without diagnostic analgesia. Palpable effusion may be present over the elbow joint, but this is typically difficult to determine.

Special examination

Flexion or extension tests of the elbow may help localize the lameness to this region. Horses with effusion in the elbow joint will typically have a positive response to flexion. Interpretation of these tests may be difficult since some normal horses resent this leg manipulation. Comparison to the contralateral limb is recommended. Intra-articular anesthesia will improve the lameness in these cases.3,5

Laboratory examination

Synovial fluid collected from the elbow joint in horses with osteoarthritis may demonstrate an increased nucleated cell count, but does not typically exceed 10 000 cells/uL and total protein will typically be less than 2.0 g/dL. Cytological differential cell counts will have a predominantly (>90%) mononuclear cell population.

Diagnostic confirmation

The best way to confirm the diagnosis is with radiography (Fig. 18.3). Periarticular osteophytes, enthesiophytes, subchondral lysis or sclerosis, and decreased joint space can confirm the diagnosis.

Therapeutic aims

Therapeutic strategies are aimed at decreasing the inflammation within the joint. Complete resolution should not be expected, as osteoarthritis is a progressive condition and in this joint can be difficult to manage.

Therapy

Therapies to treat osteoarthritis include: intra-articular corticosteroids, hyaluronan, polysulfated glycosaminoglycans or IRAP (see Chapter 23). Systemic joint therapies such as NSAIDs, hyaluronan, and polysulfated glycosaminoglycans can also be explored for treatment. Numerous oral supplements are available to reduce inflammation, but the authors typically only recommend those that have undergone testing such as glucosamine and chondroitin sulfate, specifically brands such as Cosequin® ASU (Nutramax® Laboratories, Inc Edgewood, MD, USA) as they have been tested for their contents and studied in clinical trials. Significant disease modifying effects have not been demonstrated in horses although anectodal evidence of efficacy abounds. Topical medications such as 1% diclofenac sodium (Surpass® Boehringer Ingelheim Vetmedica, Inc. St. Joseph, MO, USA) has proven to have disease modifying effects in carpal joints with osteoarthritis and as such are frequently recommended to treat other joints with osteoarthritis.¹⁹

Prognosis

The prognosis for treating low-grade osteoarthritis is good with administration of the medications listed above; however, as this disease is progressive, these medications will ultimately become less effective over time. Prognosis is dependent upon the response to therapy, but cases with advanced radiographic changes will likely have a guarded prognosis for long term soundness. Overall osteoarthritis in this joint is more difficult to manage than in other joints.³

History and presenting complaint

Horses present with a swelling over the point of the elbow. The overlying skin may either be closed or open resulting in local infection. There is typically no lameness.20,21

Physical examination

Examination reveals a swelling over the point of the elbow that is not associated with the underlying bone (Fig. 18.4). The swelling is usually freely movable. Typically lameness is not present, even with infection. The non-septic swelling typically contains fluid, fibrous tissue or both.²¹ If the skin is damaged it is possible that there may be a wound and associated local infection.

Special examination

Palpable and visible examination is typically diagnostic. Radiographs may be performed to determine if there is any olecranon involvement; however, this is typically not necessary in most cases. Cases where a penetrating trauma occurred near the olecranon, osteomyelitis may occur, but is rare.

Laboratory examination

Collection of hygroma fluid may be attempted, but does not provide further information unless it is septic.

Diagnostic confirmation

Visual examination and palpation is diagnostic. Cases with lameness or open wounds associated with the swelling warrant radiographs to rule out fractures or osteomyelitis of the olecranon.

Therapeutic aims

As this is typically a cosmetic blemish, most can be ignored; however, treatments can be explored to remove the swelling.

Therapy

If therapy is chosen, injections with corticosteroids, orgotein, dysprosium-165 or atropine have been reported.20,21 Similarly injection of iodine or Lugol’s solution has been reported to be successful.^3,21 Regardless of the product injected, most are unrewarding and/or require multiple injections to treat the condition. If there is an open wound, lavage with curettage of the ‘bursal’ lining can resolve the bursitis. The bursa may be surgically resected if the above methods fail to resolve the condition.

Prognosis

The prognosis for soundness is excellent. Unless surgical excision is performed, multiple treatments are typically required and may be frustrating to treat.

History and presenting complaint

Horses present with a variable degree of lameness, but it is typically severe in the acute stages. The resultant lameness after this acute phase is dependent upon the degree of injury to the region if the elbow is destabilized.³

Physical examination

Horses will typically have a severe lameness and may have soft tissue swelling over the corresponding trauma. Abduction or adduction of the limb may provide a presumptive diagnosis; however without complete tearing the bone articulation between the humerus and the radius/ulna, the diagnosis may be difficult without imaging.³

Special examination

Ultrasound is the diagnostic method of choice for collateral ligament injuries. Radiography can be beneficial in cases where the ligament is completely torn, there are avulsion fragments or secondary osteoarthritis within the elbow joint.²² Distraction views can be helpful in diagnosing the rupture (Fig. 18.5). Nuclear scintigraphy can be beneficial if ultrasound or radiographs fail to diagnose the condition due to the bone attachments of these ligaments to the lateral humeral epicondyle or the lateral radial tuberosity. Intra-articular analgesia may improve the lameness; however, if the tears are outside of the elbow joint, these may be negative.

Laboratory examination

There are no specific laboratory tests to diagnose the condition. Synovial fluid may demonstrate a non-septic inflammation if the joint has instability.

Diagnostic confirmation

Ultrasound is the most effective way to diagnose collateral ligament tears. Radiography with stressed views can help determine joint stability or confirm complete ligament rupture as well as evaluate for avulsion fragments or osteoarthritis.

Therapeutic aims

The goal of therapy is for the ligament to heal via rest with or without regenerative therapies.

Therapy

As there are no surgical procedures for treating these ligaments, healing is by second intention. Regenerative therapies such as bone marrow derived mesenchymal stem cells or platelet rich plasma may be beneficial in these cases.23–25 Recheck ultrasound and lameness examinations should be performed periodically. The horse should be kept under stall confinement for at least a few months depending upon the degree of damage and then can be gradually re-introduced to handwalking. The course of healing will depend upon the degree of damage, but can take upwards of six months to one year for complete healing. Rehabilitation depends on ultrasound appearance on recheck examinations.

Prognosis

The prognosis for return to use in partial collateral ligament injury is good; however, horses with secondary osteoarthritis or those that have subluxation of the elbow joint may have persistent osteoarthritis and thus have a more guarded prognosis.