Synovial Sepsis Research Articles

Transthecal Arthroscopy of the Palmar Distal Interphalangeal Joint in the Horse: A Cadaver Study.

To describe a transthecal approach to the palmar pouch of the distal interphalangeal joint (DIPJ) in horses and compare it with the conventional blind arthroscopic technique. Ex vivo study. Cadaver forelimbs (n = 26 pairs) from mature horses. One limb from each pair was randomly assigned to each arthroscopic approach (conventional or transthecal). The conventional arthroscopic approach was performed as previously described and the transthecal approach was performed through sharp dissection of the distal reflection of the digital flexor tendon sheath (DFTS). The proportion (0-100%) of the navicular bone, palmar aspect of the condyles of the 2nd phalanx, collateral sesamoidean ligaments, and palmar synovial pouches of the DIPJ visualized by each approach was estimated. Limbs were dissected and iatrogenic damage of relevant structures was assessed. Nondirectional Mann-Whitney U-test was used to compare groups. Significance was set at P < .05. The transthecal approach provided greater visualization of the navicular bone (P < .001), palmar aspect of the 2nd phalanx (P < .001), and palmar synovial pouches of the DIPJ (P < .001) than the conventional approach. There were no significant differences in iatrogenic damage between approaches. The transthecal approach provides improved visualization of the palmar aspect of the DIPJ compared to the conventional blind approach and may be useful in nonseptic conditions of the DIPJ. However, because of the creation of communication with the DFTS, use of the transthecal approach for suspected synovial sepsis of the DIPJ may be contraindicated.

Clinical Research Abstracts of the British Equine Veterinary Association Congress 2015.

Blackthorn (Prunus spinosus) is recognised as causing infections and tissue reactions. To describe the presentation, diagnosis, treatment and outcome of blackthorn plant thorn synovitis in the horse. Case series. All cases in this prospective study presented with acute onset synovitis within 24 h of thorn penetration, had a standardised clinical assessment, surgical treatment and aftercare. Surgical treatment was performed within 24 h of presentation under general anaesthesia, using a 2-stage procedure: Stage 1: perisynovial technique. Ultrasound guided placement of a 20 gauge 35 mm needle marker that is used as a guide for electrosurgical dissection onto perisynovial thorn fragments. Stage 2: endoscopic technique. Using standard and novel portals to locate and remove thorn fragments and debris from synovial structures. Thirty-five cases met the study inclusion criteria over a 24 month period. Mean lameness score on presentation was 4/5 (range 1-5). The most commonly affected structures were fetlock joints (11/35) and tendon sheaths (10/35). Mean synovial fluid total protein was 50.5 g/l (range 18-116), and TNCC was 158 x 10(9) (range 21-412) on presentation and 12 x 10(9) (range 1-46) at 48 h post operatively. All synovial fluid cultures were negative. All horses were sound (grade 0) at 5 days post operatively and all returned to full work. There are a limited number of case series of blackthorn injury in humans; however, the consensus is that surgical treatment is required for a successful outcome. The 2-stage surgical procedure described, achieved accurate identification and removal of thorn material in all cases. In contrast to previous studies on synovial sepsis, these cases had a positive outcome despite high pre- and post operative synovial fluid total protein and TNCC. These findings suggest that thorn synovitis cases have a different aetiology from synovitis originating from sepsis or contamination. Ethical animal research: The study was reviewed and approved by the Ethics Committee, School of Veterinary Medicine and Science, University of Nottingham. Owners gave informed consent for their horses' inclusion in the study. None. Competing interests: None declared.

Post operative synovial sepsis following endoscopic surgery: Increased risk associated with the carpal sheath.

The overall rate of sepsis following endoscopic surgery of synovial structures has not previously been documented. Clinical observation has led to the conjecture that tendon sheaths, in particular the carpal flexor tendon sheath, are more prone to post operative synovial sepsis than other synovial structures. To document and investigate the rate of post operative synovial sepsis following elective endoscopic surgery. Retrospective case series. The medical records of horses that underwent arthroscopy, tenoscopy or bursoscopy at Donnington Grove Veterinary Surgery between January 1999 and July 2012 were reviewed. The signalment, anatomical structure involved, use of electrosurgery, tourniquet or motorised resector, presence of a fracture, whether surgery was performed with the horse standing or under general anaesthesia and the number of structures examined were recorded. Multivariable logistic regression was used to test the association between the selected variables and synovial sepsis. Odds ratios (OR) and 95% confidence intervals (CI) were calculated. Level of significance was P<0.05. There were 1670 horses that underwent endoscopic surgery of 3159 synovial structures: 2517 joints, 583 tendon sheaths and 59 bursae. There were 16 cases of post operative sepsis in 16 horses; therefore, the infection rate was one per 100 horses or 5 per 1000 procedures. Carpal sheath tenoscopy was associated with an OR of developing post operative synovial sepsis of 14.9 (95% CI 4.8-45.9, P<0.001) compared to other synovial structures. Tendon sheath endoscopy had an OR of developing post operative synovial sepsis of 5.21 (95% CI 1.24-21.91, P<0.02) compared to other synovial structures. Surgeons should be aware that tendon sheaths and the carpal sheath in particular appear to have higher odds of developing sepsis following endoscopic surgery.

Ultrasonographic appearance of normal and injured lateral patellar ligaments in the equine stifle.

Ultrasound is widely used in horses with stifle lameness, yet limited information is available regarding the appearance of normal and injured lateral patellar ligaments (LPL). To map the normal ultrasonographic appearance of the LPL. To describe the clinical and ultrasonographic features of LPL injuries. Descriptive study of healthy horses and retrospective case series. Twelve horses without stifle lameness underwent ultrasonographic examination of bilateral LPLs and ultrasonographic features were recorded. Eighteen horses with LPL injury were identified from 1999 to 2011. The normal LPL changes in appearance from origin to insertion. It shows ill-defined margins at the patella, becomes flattened and bilobed over the lateral trochlear ridge, is oval-triangular shaped with variable echogenicity and fibre pattern distal to the LTR, and becomes tapered with striations at the tibial insertion. LPL injury was identified in 18 horses of multiple breeds and uses. All injuries were acute, and 12 had wounds. Eleven horses were severely lame (grade 4-5/5). Ultrasonographic lesions were severe in 78% of cases. The mid to insertional portion of the LPL was most often affected. Radiography showed fractures of the tibial tuberosity (n = 6), patella (n = 4) and lateral trochlear ridge (n = 1). Fractures involved LPL attachments in 9 horses. Five were treated for osteomyelitis and one for synovial sepsis. Recheck ultrasound in 4 horses showed minimal to no change in the appearance of LPL injuries. Nine horses returned to riding, one continued as a broodmare, 2 were retired, one became a broodmare, 2 were lost to follow-up and 3 were subjected to euthanasia owing to concurrent injuries. Normal variations in shape, echogenicity and fibre pattern of the LPL are important considerations to prevent false positive diagnoses during ultrasonography. LPL injuries were often severe and associated with craniolateral stifle trauma. Prognosis varied from good to guarded in horses without additional severe injuries.

Infraspinatus and intertubercular (bicipital) bursae sepsis

SummaryThe case report by O'Sullivan et al. in this month's issue of EVE describes an unusual case of synovial sepsis raising interesting points on synovial infection in general and more specifically the implication of haematogenous spread of bacteria from a remote site in the mature horse. The identification of synovial sepsis in this location is challenging due to the complex and unfamiliar anatomy in the shoulder region. This clinical commentary reviews the anatomy in this region and discusses the unusual presentation of synovial sepsis secondary to haematogenous spread.

Treatment of aStandardbred racehorse for septic infraspinatus and intertubercular bursitis caused by haematogenous bacterial spread

SummaryThis report describes the diagnosis and treatment of synovial sepsis of the infraspinatus and intertubercular (bicipital) bursae. The origin of infection was considered to be haematogenous spread from an ipsilateral foot abscess. The horse responded well to treatment and returned to full athletic function.

EquineReview

Introduction: This edition of Equine Review considers papers on factors associated with survival following treatment for synovial sepsis, septic sialoadenitis, and the effects of psyllium and magnesium sulphate for the removal of sand from the large colon.

Factors associated with survival to hospital discharge following endoscopic treatment for synovial sepsis in 214 horses

To determine risk factors involved in survival to hospital discharge of cases of synovial sepsis. Investigate pre-, intra- and post operative factors involved in short-term survival of horses undergoing endoscopic treatment for synovial sepsis. Retrospective case series. Clinical data were obtained for horses (>6 months old) undergoing endoscopic surgery as part of management for synovial sepsis over a 7-year period in a single hospital population. Descriptive data were generated for pre-, intra- and post operative variables. Multivariable logistic regression analysis was used to develop 3 models related to presurgical, surgical and post surgical stages of management with outcome defined as survival to hospital discharge. Two hundred and fourteen horses were included. In Model 1 (preoperative variables), increased preoperative synovial fluid total protein (TP) was associated with nonsurvival (OR 0.88, 95% CI 0.83-0.94, P<0.001) whereas the presence of a wound on admission was associated with survival (OR 4.75, 95% CI 1.21-18.65, P = 0.02). Model 2 (intraoperative variables) revealed that factors associated with decreased survival were anaesthetic induction outside of normal working hours (OR 0.36, 95% CI 0.15-0.88 P = 0.02) and presence of moderate/severe synovial inflammation at surgery (OR 0.28, 95% CI 0.12-0.67, P = 0.004). Model 3 (post operative variables) showed that increased post operative synovial fluid TP (OR 0.94, 95% CI 0.90-0.98, P = 0.013) and undertaking more than one endoscopic surgery for treatment (OR 0.19, 95% CI 0.05-0.70, P = 0.005) were associated with nonsurvival. Cut-off values for predicting survival were 55-60 g/l for preoperative and 50-55 g/l for post operative TP measurements. This study has identified factors associated with altered likelihood of survival to hospital discharge following endoscopic surgery for synovial sepsis. Prognosis for survival to hospital discharge can be based on evidence from this study at the key stages of management of horses with synovial sepsis.

Outcome of horses with synovial structure involvement following solar foot penetrations in four UK veterinary hospitals: 95 cases

The factors associated with outcome following solar foot penetration involving synovial structures treated using endoscopic lavage have not been described in the UK population. To provide descriptive data on horses with synovial contamination or sepsis following solar penetration in 4 UK equine referral hospitals and to identify specific factors associated with the outcome. Retrospective case series. Data were collected from 4 veterinary hospitals. Follow-up data were obtained via a telephone questionnaire. Two multivariable logistic regression models were generated. Model 1 included all horses with synovial contamination following foot penetration undergoing surgical treatment, with the outcome variable being euthanasia during hospitalisation. Model 2 included all horses surviving anaesthesia, with the outcome variable being failure to return to pre-injury athletic function. Ninety-five horses were included. Overall, 56% of horses survived to discharge and 36% of horses returned to pre-injury athletic function. Model 1 included penetration of the central frog sulcus (odds ratio [OR] 10, 95% confidence interval [CI] 1.9-51.8), concurrent distal phalanx involvement (OR 32, 95% CI 2.6-101.9), increasing days to presentation (OR 1.2, 95% CI 1.0-1.3) and hospital. Model 2 included increasing days to presentation (OR 1.1, 95% CI 1.1-1.6), breed (OR 32, 95% CI 2.2-135.4), more than one surgery (OR 5.6, 95% CI 1.0-32.7) and hospital. Synovial involvement following solar foot penetration has a guarded prognosis for survival to discharge and a poor prognosis for return to pre-injury athletic function. Penetration of the central sulcus of the frog and distal phalanx involvement are associated with euthanasia during hospitalisation. Delayed referral and hospitalisation are associated with both euthanasia and failure to return to pre-injury athletic function. Breed and more than one surgery are associated with failure to return to pre-injury athletic function. These data may assist veterinary surgeons and owners to make evidence-based decisions when managing cases with synovial involvement following solar foot penetration.

Risks of Synovial Sepsis Following Intrasynovial Medication in Ambulatory Practice, 2006–2011: 9456 Intrasynovial Injections

AimsTo determine the incidence of synovial sepsis following intra‐articular and intrathecal injections. Synovial sepsis is a serious potential complication of intrasynovial medication.MethodsAvailable case records for all horses receiving intrasynovial medications (ISMs) performed by 9 ambulatory clinicians were examined over 5 years (2006–2011). Intrasynovial medications were defined as therapeutic interventions, based on clinical history and orthopaedic examination; nontherapeutic injections for diagnostic analgesia were excluded. Routine protocol was not to clip injection sites; the skin was prepared using standard aseptic technique. Scrupulous aseptic injection technique was employed at all times. All horses were under the care of a single practice, dealing with mainly Thoroughbred racehorses. Records were cross‐referenced against synovial cytology submissions and hospital admissions for synovial sepsis. Development of 2 out of 4 clinicopathological signs of synovial sepsis (lameness, joint distension, synovial white blood cell count &gt;10,000/l, synovial total protein &gt;25 g/l) within 8 weeks of medication of the same synovial space was considered to represent a post medication complication (PMC). Failure of the PMC to resolve with conservative therapy was considered to represent post medication synovial sepsis (PMSS).ResultsDuring the study period 9456 ISMs were recorded, in 4332 sessions, in 1732 horses. Corticosteroids were included in 92.3% of ISMs, 94.8% included amikacin and 0.15% (14/9456) included polysulphated glycosaminoglycans (PSGAGs). Twelve horses developed PMC (0.0013% ISM), 4 horses developed PMSS (0.0004% ISM). All 4 horses returned to use following joint lavage. Administration of intrasynovial PSGAGs, was significantly associated with PMSS (P&lt;0.0001 OR = 787 95% CI 145–20,337). Intrasynovial medications that included amikacin were less likely to develop PSSM (P = 0.005 OR = 0.0181 95% CI 0.0019–0.174); however if the PSGAGs group was excluded the difference became nonsignificant (P = 0.0981).Conclusions and practical significanceThe risk of iatrogenic sepsis following intrasynovial medication is extremely low. Intrasynovial medication with PSGAGs should be avoided without concomitant antimicrobials.AcknowledgementsA. Wilson and K. Batteate for case collation.Ethical animal researchNot required by this Congress: retrospective analysis of case records. Sources of funding: None. Competing interests: None.

Operative Hip Arthroscopy, 3rd ed

Operative Hip Arthroscopy is a third edition update by the renowned hip arthroscopist J. W. Thomas Byrd, M.D., from Nashville. Dr. Byrd begins this text by dedicating the work to his 2 primary mentors, his father, Benjamin Franklin Byrd, Jr., M.D., and his fellowship director, James R. Andrews, M.D. To quote his father, “a surgeon is just a regular doctor, with a few special skills.” He thanks his mentors for sharing their skills and instilling in him a remarkable desire to make the most of his abilities. The first and second editions of this text were well received by the orthopaedic community, and the third edition effectively merges the latest technical progress in hip arthroscopy with the basics of the pathophysiologic processes behind hip disease. The book covers all aspects of hip arthroscopy as it stands today, and Dr. Byrd's techniques have proved safe, efficient, and reproducible. Lanny Johnson, M.D., in his forward states, “This text includes a comprehensive review of the pertinent anatomy and pathological processes that are potentially amenable to the ever widening application of arthroscopy.” The book is composed of 34 chapters compiled from 47 different contributors, all experts in their fields, ranging from hip arthroscopists to physical therapists, radiologists, arthroplasty surgeons, and sports medicine physicians. This breadth of involvement ensures the quality and completeness of the topics discussed. Dr. Byrd begins the text with an invigorating overview and history of hip arthroscopy, after which he details his criteria for patient selection and reviews the thorough physical examination. The remainder of the text comprehensively covers imaging; anatomy; patient positioning and distraction options; portal placement; tips for access to the central and peripheral compartments; management of labral, chondral, and pulvinar pathologic conditions; and synovial disease and sepsis. Dr. Byrd, and then Trevor Gaskill, M.D., and Marc Philippon, M.D., offer “My Approach to Femoroacetabular Impingement,” which is an interesting comparison of the thoughts and techniques from some of the world's best hip arthroscopists. The latter half of the book addresses some emerging techniques and thoughts for extra-articular hip disorders of the iliopsoas tendon, iliotibial band, abductor tendons, subgluteal space, and hamstrings. Many of these techniques are truly cutting edge and represent a new frontier in hip endoscopy. The last few chapters are dedicated to other concepts such as hip instability, hip arthroscopy in the pediatric population, complications in hip arthroscopy, rehabilitation, and postoperative care. The text is heavily illustrated with high-quality arthroscopic images, cadaveric sections, demonstrative photographs, helpful drawings, and links to videos. In summary, the third edition of Operative Hip Arthroscopy by Dr. J. W. Thomas Byrd has effectively pulled together an amazing team of expert contributors to discuss the latest and greatest in hip arthroscopy. This book emphasizes wise decision making and a thorough understanding of the dos and don'ts of the procedure. This book is a must for any orthopaedist in practice or training who treats these patients or wants a complete picture of this procedure and related issues.

Indwelling Cephalic or Saphenous Vein Catheter Use for Regional Limb Perfusion in 44 Horses with Synovial Injury Involving the Distal Aspect of the Limb

To describe indwelling cephalic or saphenous vein catheter use for intravenous regional limb perfusion (ID-IV-RLP) to treat horses with synovial injury (contamination/infection) of the distal aspect of the limb. Retrospective case series. Horses (n = 44; 45 limbs) treated with proximal ID-IV-RLP. Horses had ID-IV-RLP using a cephalic (21 limbs) or saphenous (24 limbs) vein. Amikacin was the most frequently used antibiotic. Number of perfusions ranged from 3 to 21 (median 7). A cast was applied to 14 injured limbs (1 tube cast, 1 full-limb cast, 2 foot casts, and 10 half-limb casts). Synovial sepsis of the distal portion of 87% of limbs (39) resolved, and 61% of horses returned to soundness. Catheter-related complications occurred in 27% of the limbs but were not significantly associated with outcome. Presence of osteomyelitis was significantly associated with a poor outcome. ID-IV-RLP using the cephalic or saphenous vein is an alternative to traditional RLP. An indwelling catheter provided prolonged venous access and facilitated successive perfusions.

Multi-drug-resistant Enterococcus spp. as a cause of non-responsive septic synovitis in three horses

CASE HISTORY: Three Thoroughbred horses, a 6-week-old filly (Case 1), a 15-year-old broodmare (Case 2) and a yearling filly (Case 3), sustained synovial sepsis secondary to trauma. CLINICAL FINDINGS: Case 1 presented with a heel bulb laceration communicating with the distal interphalangeal joint. Arthroscopic lavage was performed and treatment commenced using systemic and local broad spectrum antimicrobial drugs. A pure growth of multi-drug-resistant (MDR) Enterococcus gallinarum was cultured from samples of synovium and joint fluid. Antimicrobial treatment was changed according to the susceptibility results. Response to treatment was poor and despite repeat arthroscopic lavage and intra-osseous regional perfusion of antimicrobials the filly was subject to euthanasia 24 days after the initial injury. Post-mortem examination confirmed septic synovitis, cartilage degeneration and osteomyelitis. Case 2 sustained a full thickness wound to the carpus which was sharply debrided and closed. The wound dehisced with effusion within the tendon sheath. Drainage was established and treatment included systemic broad spectrum antimicrobials, topical lavage with povodine-iodine and manuka honey infusion. A mixed infection including MDR Enterococcus faecalis was cultured from the synovial fluid. Antebrachiocarpal joint effusion developed 21 days after initial injury and joint sepsis was confirmed. Arthroscopic lavage and tendon sheath debridement were performed, followed by treatment with systemic and local antimicrobials. The mare improved and was discharged. Three months later lameness recurred and corticosteroids were administered intra-articularly. The mare became non-weight bearing lame and was subject to euthanasia. Post-mortem examination confirmed joint sepsis of the antebrachiocarpal and intercarpal joint. Case 3 presented with a complete articular open fracture of the tibial crest. Under general anaesthesia the fracture was stabilised and the wounds debrided and closed. Systemic broad-spectrum antimicrobials were administered. Six days later the wound dehisced and a bone fragment was removed. Three weeks post-surgery the wound deteriorated with a purulent discharge. Culture of the discharge revealed a mixed bacterial infection, including a MDR Enterococcus faecalis. Femoropatellar joint involvement was confirmed, and treatment included joint lavage, local and systemic antibiosis, and manuka honey instilled into the wound. The filly initially improved, and then deteriorated such that euthanasia was performed. DIAGNOSIS: All three cases had synovial sepsis with MDR Enterococcus spp. CLINICAL RELEVANCE: Increased awareness of MDR pathogens in equine wound infections is essential. Prompt diagnostic testing, appropriate therapy, infection control strategies and on-going monitoring and management are vital to limit the clinical impact of these organisms.

Retrospective investigation of prognostic indicators for adult horses with infection of a synovial structure

To investigate predictors of survival and athletic function in adult horses with infection of a synovial structure. Increasing duration from contamination to referral, bone or tendon involvement and positive microbial culture decreases short-term survival. Synovitis and/or sepsis at 5 days post-admission and involvement of Staphylococcus spp. decreases long-term athletic function. Retrospective study. Records over 4 years of adult horses with synovial sepsis were reviewed. A two-tailed Fisher's exact test, Mann-Whitney U test or t-test was used to examine whether variables were predictive of short-term survival and long-term athletic function. During the study period 75 horses underwent treatment for infection of 93 synovial structures. Short-term survival was 84% (63/75) and 54% (30/56) of horses returned to athletic function. Of the variables measured at admission, duration from contamination to referral did not affect survival, whereas evidence of bone or tendon involvement decreased survival and athletic function. Of the variables available during treatment, abnormal synovial fluid at 4-6 days post-admission and positive microbial culture reduced athletic function. Staphylococcal infection was associated with persistent sepsis. Of the variables available at presentation, only evidence of bone or tendon involvement negatively affected survival and athletic function. During treatment of synovial sepsis, analysis of synovial fluid at 4-6 days and bacterial culture results have prognostic value.

Use of blood culture medium enrichment for synovial fluid culture in horses: A comparison of different culture methods

Standard methods for culturing equine synovial fluid (SF) are often unrewarding. Evidence-based information on the relative efficiency of different systems used for optimisation of isolation of microorganisms from equine SF is lacking. To compare the results of different culture systems performed in parallel on SF samples from horses clinically diagnosed with synovial sepsis. Synovial fluid specimens were collected between February 2007 and October 2008 from all horses admitted to a referral hospital that were clinically diagnosed with synovial sepsis and from control horses. Synovial fluid samples were cultured in parallel by: 1) direct agar culture (DA); agar culture after: 2) lysis-centrifugation pretreatment (LC); 3) conventional enrichment (CE); 4) combined LC/CE; or 5) blood culture medium enrichment using an automated system (BACTEC 9050). Ninety SF samples from 82 horses were included, together with 40 control samples. Seventy-one of 90 samples (79%) were culture-positive by using blood culture medium enrichment (BACTEC), which was significantly higher compared to all other methods. BACTEC enrichment was never negative while any of the other methods was positive. Although agar culture following LC and/or CE resulted in a slightly higher number of positive samples compared to DA, this difference was not significant. All control samples were culture negative by the 5 different techniques. Although the majority of samples containing isolates recovered without enrichment, culture results after BACTEC enrichment were available on the same day as for agar culture with or without LC (19/23 samples), while CE postponed recovery by at least one day in 20/23 samples. Blood culture medium enrichment is superior to other techniques for isolation of bacteria from SF of horses. The use of an automated system allows enrichment without substantially postponing recovery of microorganisms. The efficient and fast isolation of microorganisms from infected SF by the BACTEC system allows for rapid susceptibility testing and a more appropriate antibiotic treatment.

Bacterial culture of septic synovial structures of horses: Does a positive bacterial culture influence prognosis?

The influence of synovial fluid culture on short- and long-term prognosis of cases with septic synovitis requires study. Horses with a positive bacterial culture from septic synovial fluid are less likely to survive or return to successful athletic function than those with a negative bacterial culture from septic synovial fluid. Records of mature horses presented to 2 equine referral hospitals for investigation of suspected septic synovitis were examined. Horses (n=206) were included in the study if synovial fluid was submitted for full laboratory examination, including bacterial culture. A diagnosis of septic synovitis was based on a nucleated cell count>30x10(9) cells/l or>90% neutrophils and other clinical, cytological and bacteriological parameters. Long-term follow-up was obtained by telephone questionnaire. Univariate analysis, using the Fisher's exact test, was used for all outcomes. Fourteen (20.9%) of 67 horses with a positive bacterial culture from synovial fluid were subjected to euthanasia because of persistent synovial sepsis compared to 2 (1.44%) of 139 with negative bacterial cultures (P<0.001). Overall survival and successful long-term return to function in horses with a positive bacterial culture was 50% (24/48 horses) compared to 70.5% (74/105) in culture negative horses (P=0.01). In horses that survived to be discharged, successful long-term return to function was not significantly different between culture positive and culture negative groups. Growth of Staphylococcus aureus from synovial fluid did not affect short-term survival to discharge from the hospital compared to other positive bacterial culture; however, successful long-term return to function was only 30.4% (4/13) in horses from which S. aureus was cultured compared to 73.9% (17/23) of horses in which other bacteria were cultured (P=0.015). CONCLUSIONS AND POTENTIAL CLINICAL RELEVANCE: Horses with a positive bacterial culture from a septic synovitis have a poorer prognosis for survival to discharge from hospital and overall long-term return to function than horses that yielded no bacterial growth. When S. aureus was cultured, the long-term prognosis was poorer.

Antimicrobial delivery by intrasynovial catheterisation with systemic administration for equine synovial trauma and sepsis

To present the technique for intra-articular catheter placement and report the clinical outcomes of 38 cases of equine synovial trauma and/or infection treated with broad-spectrum antimicrobials administered via an intrasynovial catheter (ISC). Retrospective study. Medical records of 38 horses treated for synovial trauma and sepsis with frequent antimicrobial administration through an ISC from 1995 to 2008 were reviewed. Follow-up information was obtained via clinical re-evaluation or telephone contact with the owners. The majority of horses (84%) received amikacin and Timentin(R) four times daily. In addition, synovial lavage through the ISC was carried out in 27 horses (71%). Only radiological evidence of osteolysis had a significant negative impact on both lameness at the time of hospital discharge and the long-term outcome. In total, 92% of horses treated with frequent antimicrobial administration through an ISC had clinical resolution of infection. Catheter obstruction occurred in three cases, necessitating replacement or removal, and two synovial fistulae developed at sites of open drainage. The majority of horses treated had a favourable outcome, with 86% being at least pasture sound and 43% returned to riding. Septic synovial structures treated with frequent antimicrobial administration through an ISC had a good prognosis for survival and 43% returned to riding, which is consistent with the results of other studies. The use of a simple ISC should be considered when broad-spectrum intrasynovial antimicrobial administration and lavage of a septic synovial structure are indicated.

Osteomyelitis and Osteonecrosis after Intraosseous Perfusion with Gentamicin

To describe and discuss previously unreported complications associated with intraosseous perfusion with gentamicin in horses. Case report. Ten-year-old Warmblood gelding. Intraosseous perfusion with gentamicin into the proximal phalanx (P1) was used as part of the treatment regimen for distal interphalangeal joint and navicular bursa synovial sepsis. Although the sepsis responded favorably complications developed at the perfusion site, including persistent osteomyelitis, progressive osteonecrosis, and ultimately pathologic fracture of P1. The progression of the clinical signs and findings at necropsy are suggestive of a toxic osteonecrosis secondary to intraosseous perfusion. Further work is needed to investigate the effects of high dose gentamicin on equine mesenchymal cells that may be achieved during intraosseous perfusion. Lower doses of perfusate within the medullary canal of P1 or alternative perfusion sites should be considered.

Tenoscopic surgery for treatment of lacerations of the digital flexor tendon sheath.

Lacerations to the digital flexor tendon sheath (DFTS) are a common injury in the horse, but little information is available in the literature regarding prognostic indicators. To ascertain whether laceration of the DFTS carried a better prognosis if treated by tenoscopic lavage, debridement and repair within 36 h of the original injury. A retrospective analysis of 39 horses treated surgically for lacerations to the DFTS was performed over a 3 year period. The injury-to-surgery interval was recorded as <36 or >36 h. The structures damaged by the injury were also recorded, as well as age, sex, use and outcome. Sixteen horses had laceration and contamination of the DFTS alone, of which 15 (94%) returned to their original or intended use. Sixteen horses had lacerations involving the superficial digital flexor tendon, of which 12 (75%) made a full recovery. Six horses had lacerations to both superficial and deep digital flexor tendons, 5 were subjected to euthanasia intraoperatively and one is paddock sound. Treatment within 36 h of initial laceration carried a significantly better prognosis for return to intended athletic use (25 of 28 horses allowed to recover from anaesthesia) than treatment after 36 h (2 of 5 P = 0.03; Fisher's Exact Test). If sepsis is treated early using tenoscopic visualisation, lavage and repositol antibiotics, the limiting factor in return to athletic function is tendon damage. This study supports anecdotal evidence that early treatment of synovial sepsis improves the prognosis for return to intended use. It also provides information on prognostic indicators including extent of damage to collateral structures.

Treatment of traumatically induced synovial sepsis in horses with gentamicin-impregnated collagen sponges

Eight horses with synovial sepsis induced by trauma were treated by arthroscopic/tenoscopic debridement and lavage followed by the implantation of a gentamicin-impregnated collagen sponge. Seven of them responded favourably and...