Treatment of bacterial tarsal tenosynovitis and osteitis of the sustentaculum tali of the calcaneus in five horses

What is the likelihood that a horse treated for septic digital tenosynovitis will return to its previous level of athletic function?

REASONS FOR PERFORMING STUDY

Septic digital tenosynovitis is a serious problem in the horse, with a poor prognosis being reported for recovery.

HYPOTHESIS

The occurrence of septic digital tenosynovitis would significantly reduce the likelihood of a horse returning to its previous level of athletic function.

METHODS

Medical records of 90 horses treated for septic digital tenosynovitis were reviewed. Data retrieved included age, sex, location of inciting cause of sepsis, time from onset of clinical signs to presentation for treatment, and whether the horse survived to be discharged. Long-term outcome was determined through telephone questionnaires. Univariate analyses of categorical variables were conducted for each outcome.

RESULTS

Overall, 87.8% of horses (79/90) survived to be discharged from the hospital. Only one factor examined was shown to have a significant effect on outcome. A delay of 1-7 days between onset of clinical signs and presentation for treatment reduced significantly the likelihood of the horse surviving to be discharged from the hospital. Of the horses discharged from the hospital, long-term follow-up was available for 72 horses, with 54.2% (39/72) returning to their previous level of athletic function.

CONCLUSIONS

Only approximately 50% of horses treated for septic digital tenosynovitis returned to their previous level of athletic function following resolution of synovial sepsis.

POTENTIAL RELEVANCE

Accurate figures allowing a realistic assessment of the athletic future of a horse following treatment for septic digital tenosynovitis are of value to both the owner and treating veterinarian.

Septic tenosynovitis of the tarsal sheath of an Arab gelding and suspected sepsis of the lateral digital flexor tendon subsequent to bacterial peritonitis

A 21-year-old Arab gelding with clinical signs of acute peritonitis had a perforating ulcer on the mesenteric border of the jejunum which resulted in localised contamination of the abdomen with ingesta. The affected segment of jejunum was resected and the abdomen was lavaged extensively. Postoperatively, the gelding was treated with broad-spectrum antibiotics, non-steroidal anti-inflammatory drugs and intravenous fluids, but after four days it became acutely non-weight bearing on its right hindlimb, and a tendonitis of the lateral digital flexor tendon within the tarsal sheath was identified ultrasonographically. The septic tendonitis was treated with broad-spectrum antibiotics but progressed proximodistally within the tendon until it involved both the tarsal sheath and the associated tarsocrural joint, necessitating the euthanasia of the gelding.

Retrospective study of 24 cases of septic calcaneal bursitis in the horse

REASONS FOR PERFORMING STUDY

Wounds to the plantar aspect of the tarsus present a diagnostic and treatment challenge. This study was undertaken to describe specific features of traumatic wounds involving the calcaneal bursa, with a view to determining which clinical examination findings and diagnostic tests results could provide reliable indicators of prognosis.

OBJECTIVES

To report clinical presentation, diagnostic findings, treatment and outcome of 24 cases of septic calcaneal bursitis; and to determine the importance of the involvement of specific anatomical structures in relation to the prognosis for survival and return to athletic function.

METHODS

Records of 24 horses that had suffered traumatic wounds involving the calcaneal bursae were reviewed and divided into 3 groups, based on the bursa involved and presence or absence of involvement of the tuber calcanei. Clinical, diagnostic imaging and surgical findings were recorded for each case. Differences between groups and outcome were examined for significance with Chi-squared, Fisher's Exact or Kruskal-Wallis tests, as appropriate.

RESULTS

Wounds involving only the subcutaneous bursa had an excellent prognosis for survival. Seventy-five percent of horses with wounds involving the intertendinous calcaneal bursa survived. Involvement of the tuber calcanei presented a fair to guarded prognosis, with only 44% of horses with involvement of this structure surviving.

CONCLUSIONS

In contrast to other studies of septic synovial structures, the time between initial injury and referral did not affect the outcome. Correct identification of invasion of the calcaneal bursa(e) and/or tuber calcanei in wounds to the plantar aspect of the tarsus allows for more accurate pronostication. Damage to the tuber calcanei presents a poorer prognosis than for cases that involve only the soft tissue structures in the region.

POTENTIAL RELEVANCE

This study demonstrates the importance of correct anatomical identification of structures involved in wounds in the region of the calcaneal bursa. The use of radiography, ultrasonography and synoviocentesis are essential in these cases to provide the most appropriate treatment for the horse and accurate prognosis for the owner.

Endoscopic surgery in the treatment of contaminated and infected synovial cavities

REASONS FOR PERFORMING STUDY

Contamination and infection of synovial cavities are a common occurrence in clinical practice and, if inadequately treated, may have career or life threatening consequences for affected horses.

HYPOTHESIS

The objectives in treating contamination and infection of joints, tendon sheaths and bursae are most effectively met by endoscopic surgery.

METHODS

Over a 6 year period, cases of synovial contamination and infection admitted to a referral clinic were evaluated and treated endoscopically. The horses received local and systemic antimicrobial drugs with minimal nonsteroidal anti-inflammatory medication but no other medical or surgical treatment. All arthroscope and instrument portals and, whenever possible, all traumatic wounds were closed. Diagnostic information, endoscopic observations and results of treatment were evaluated retrospectively.

RESULTS

A total of 140 affected animals were referred and 121 cases were treated endoscopically. These involved 70 joints, 29 tendon sheaths, 10 bursae and in 12 cases a combination of synovial cavities. The most common aetiologies were open wounds (n = 54) and self-sealing punctures (n = 41). Foreign material was identified endoscopically in 41 but predicted prior to surgery in only 6 cases. Osteochondral lesions were evident at surgery in 51 and recognised before surgery in 25 cases; 32 horses had intrathecal tendon or ligament defects. Follow-up information was obtained for 118 animals; 106 (90%) survived and 96 (81%) returned to their preoperative level of performance. The presence of osteitis/osteomyelitis, other osteochondral lesions and marked deposits of pannus were associated with nonsurvival. For those animals which survived, non-Thoroughbred horses, a combination of synovial structure involvement and regional i.v. antimicrobial administration were associated with reduced post operative performance. Marked pannus, regional i.v. antimicrobial administration and duration of systemic antimicrobial administration were associated with a group combining nonsurviving animals and those with reduced post operative performance.

CONCLUSIONS

Endoscopic surgery makes a valuable contribution to the management of synovial contamination and infection.

POTENTIAL RELEVANCE

The information obtained from and therapeutic options offered by endoscopy justify its early use in cases of synovial contamination and infection.

Osteomyelitis of the sustentaculum tali in horses: 10 cases (1992-1998)

OBJECTIVE

To determine outcome of horses with osteomyelitis of the sustentaculum tali (ST), with or without associated tarsal sheath tenosynovitis, following surgical debridement and lavage.

DESIGN

Retrospective study.

ANIMALS

10 horses in which a diagnosis of osteomyelitis of the ST had been made on the basis of history, physical examination findings, and results of radiography.

PROCEDURE

Information on results of diagnostic testing, surgical findings, postoperative treatment, and short-term outcome was obtained from the medical records. Long-term follow-up information was obtained through reevaluation of horses at the teaching hospital and telephone conversations with referring veterinarians, owners, and trainers.

RESULTS

Treatment consisted of surgical debridement, intra- and postoperative lavage, and long-term antimicrobial and anti-inflammatory treatment. Eight horses had evidence of involvement of the tarsal sheath. One horse was euthanatized after surgery because of a lack of response to treatment; the other 9 were discharged from the hospital. Severity of lameness had improved, but all still had grade-1 or -2 lameness at the time of discharge. One horse was euthanatized after discharge because of contralateral hind limb laminitis, and another horse was lost to follow-up. Of the remaining 7 horses, 6 returned to their previous use, and 1 was sound but retired for breeding for unrelated reasons.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that horses with osteomyelitis of the ST, with or without concomitant tarsal sheath tenosynovitis, can have an excellent to good outcome and may return to their previous use after surgical debridement of affected tissues and lavage of the tarsal sheath.

Treatment of chronic digital septic tenosynovitis in 12 horses by modified open annular ligament desmotomy and passive open drainage

A modified open annular ligament desmotomy followed by passive open drainage was used to treat 12 horses with chronic digital septic tenosynovitis due to trauma in the form of open wounds or self-sealing punctures. The surgical approach included complete transection of the palmar/plantar annular ligament of the fetlock and proximal digital annular ligament, which facilitated the removal of fibrin, selective debridement and synovectomy, followed by lavage of the digital sheath. The incision was partially closed leaving a 2 cm gap open distally to allow for passive open drainage. Gentamicin was administered intrathecally during surgery. Postoperatively the horses received ceftiofur and non-steroidal anti-inflammatory drugs. A sterile bandage was used to protect the wound until the gap had healed completely by second intention. Infection was controlled in 11 of the horses which all returned to their previous levels of work, but one horse was euthanased as a result of the persistence of the infection and financial considerations.

Osteolytic lesions of the tuber calcanei in two horses

Two adult horses were evaluated for chronic hind limb lameness. Nonseptic calcanean bursitis with associated focal osteolytic lesions at the point of insertion of the gastrocnemius tendon was diagnosed in each horse by physical and lameness examinations, radiography, ultrasonography, and synovial fluid analysis. Both horses underwent arthroscopic exploration and lavage of the affected bursa, and one horse also underwent surgical debridement of the osseous lesion. Both horses remained lame for 13 months after the surgical procedures. To our knowledge, osseous lesions of the calcaneus in horses with nonseptic calcanean bursitis have not been reported. The flexed proximoplantar-to-distoplantar tangential radiographic view of the calcaneus was essential in localizing the lesions, as was the sonogram in one horse. Arthroscopy provided a thorough evaluation of the bursa and associated tendons. On the basis of the outcome of these 2 horses, the prognosis for complete recovery for horses with this condition appears to be unfavorable. Surgical debridement of the osseous lesion was of no benefit and may have been detrimental.

Endoscopic examination of the tarsal sheath of the lateral digital flexor tendon in horses

This study was designed to develop a reliable technique for endoscopic examination of the tarsal sheath of the lateral digital flexor tendon of horses. The anatomy of the tendon sheath and associated structures was studied in detail in cadavers before determining portals for the insertion of an arthroscope into the sheath. Approaches into the sheath through the proximal pouch and through the flexor retinaculum, at the level of the sustentaculum tali, were performed and compared in cadavers. The proximal pouch portal permitted visualisation only of the proximal half of the sheath, while the approach through the retinaculum allowed examination of the entire sheath. The normal endoscopic appearance of the tarsal sheath was studied. The endoscopic approach was subsequently used to examine and treat 5 horses with tarsal sheath tenosynovitis, including 2 cases of chronic, traumatic tenosynovitis and 3 of subacute septic tenosynovitis. Four of these horses had fragmentation of the sustentaculum tali. The technique allowed adequate examination of the sheath and debridement of adhesions and lesions within the lumen of the sheath. Fragments dorsal to the medioplantar edge of the sustentaculum tali could not be visualised endoscopically and had to be removed after widening of the wound. All 5 horses survived. Follow-up enquiries (8-31 months) revealed that the horses were all reported to be sound. Four were performing at their previous level of activity, 1 was used for hacking. The 2 cases presented with chronic tenosynovitis had residual sheath distension with no associated loss of function. A prospective study, including longer term follow-up investigation, is currently being performed.