A 4-month-old Irish Draught colt was presented for treatment of a traumatic wound to the right hind pastern region of 6 hours' duration. Investigation confirmed communication between the wound and the proximal interphalangeal joint. Due to the joint's small size, a traditional synovial endoscopic lavage could not be performed. Therefore, a needle arthroscope (Nanocope, Arthrex) was utilised to lavage the joint under general anaesthesia. The needle arthroscope allowed visualisation of the articular surface, higher ingress lavage (compared to needles), as well as assessment for potential foreign bodies. Following surgical treatment and a course of oxytetracycline, the foal returned to soundness. The wound healed without complication. Use of needle synovial endoscopy has therapeutic potential in future cases of septic synovitis in small joints that do not allow entry of a traditional synovial endoscope.

BACKGROUND:Caudal wedge ostectomy has not been investigated for overriding or impinging spinous processes (SPs). OBJECTIVES:To establish the feasibility of caudal wedge ostectomy and compare measures of surgical trauma and error between hypothetical caudal and cranial wedge ostectomies on SPs of different inclinations. STUDY DESIGN:Experimental, method comparison study. METHODS:Computed tomography and caudal wedge ostectomy surgery were performed on four cadavers. Observations, technical difficulties, and surgical errors were recorded. Radiographs from 67 horses with overriding/impinging SPs were reviewed. Hypothetical 'ideal' caudal and cranial wedge ostectomies, and 'error' ostectomies 12° from ideal, were drawn at sites of impingement. Ostectomy area/SP width, ostectomy length/SP width, absolute difference of exit angles (angle ostectomy exits the SP) from 90°, and number of error ostectomies failing to exit the SP (never-ending-cuts [NEC]) were calculated. Continuous variables were compared between techniques in caudally and cranially inclined SP groups using Wilcoxon signed-rank tests. Proportions of NEC were compared using McNemar's tests. RESULTS:No surgical errors were recorded with caudal wedge ostectomy. Median ostectomy area/SP width was lower for caudal versus cranial wedge ostectomy in caudally (14.32, interquartile-range [IQR] 9.72-20.34 vs. 25.57, IQR 17.74-33.06; p < 0.001) and cranially inclined SP groups (11.78, IQR 7.98-17.19 vs. 19.62, IQR 13.65-28.68; p < 0.001). Median difference in exit angles from 90° was smaller for caudal versus cranial wedge ostectomies in caudally (34.77°, IQR 26.85°-45.91° vs. 67.54°, IQR 58.13°-74.55°; p < 0.001) and cranially inclined SP groups (49.14°, IQR 35.61°-59.33° vs. 62.84°, IQR 55.34°-70.61°; p < 0.001). The proportion of NEC was lower for caudal versus cranial wedge ostectomy in caudally (37.6%, 95% confidence interval [CI] 29.4%-45.8%; n = 50/133 vs. 96.2%, 95% CI 93.0%-99.5%; n = 128/133; p < 0.001), but not in cranially inclined SP groups (76.8%, 95% CI 70.9%-82.7%; n = 152/198 vs. 84.3%, 95% CI 79.3%-89.4%, n = 167/198; p = 0.06). MAIN LIMITATIONS:Potential bias drawing 'ideal' ostectomy. CONCLUSIONS:Experimentally, caudal wedge ostectomy was feasible, removed less bone, and resulted in fewer NEC in caudally inclined SPs. Further investigation of the technique is warranted.

Summary An 18‐year‐old Thoroughbred gelding was referred for further investigation and treatment of acute colic. Exploratory celiotomy was recommended based on the degree of suspected large colon distension on rectal palpation, and only transient reprieve from colic signs following analgesia. This subsequently revealed an intussusception affecting the left dorsal colon (LDC) with the orad LDC (intussusceptum) within the aborad LDC (intussuscipiens). The intussusception, approximately 20 cm in length, was obstructing the colon. Following exteriorisation, reduction of the intussusception was performed, but marked thickening of the colon wall and luminal obstruction led to the decision to perform a partial colon resection of the left dorsal and ventral colon and side‐to‐side anastomosis. The gelding made an unremarkable recovery from anaesthesia and progressed well post‐operatively. Histopathology found no clear cause of the intussusception. Follow‐up (11 months post‐operatively) confirmed complete recovery and the horse had returned to the previous level of light exercise.

BackgroundCross-sectional imaging improves the diagnostic accuracy of complex anatomical regions. Computed tomography (CT) of the pelvis and caudal spine in a large group of live horses and ponies has not been previously reported.ObjectiveTo describe the procedure for acquiring CT images of horses' caudal spine/pelvis under general anaesthesia (GA) and to detail the image quality, artefacts and anatomical variations in this region.Study designRetrospective case series.MethodsHorses with CT of the caudal spine/pelvis were included. Horses under 6 months and CT examination performed post-mortem were excluded. Protocols, image quality, region of interest, anatomical features and morbidities were analysed.ResultsFifty-six horses (8 months to 20 years, 85-680 kg) met the inclusion criteria. GA ranged from 10 to 60 min (mean: 30, median: 32). There were no adverse events recorded in any of the horses associated with the procedure. Images of all horses were considered of diagnostic quality. Anatomical variations were common and included the location of diverging (widest) interspinous space, the presence of spina bifida in the lumbar and sacral spine, the shape of the last lumbar vertebra and the location of intertransverse joints in terms of where they were present and the degree of fusion/modelling.Main limitationsNot all horses underwent CT examination of the same regions, the upper size limit of horses is unknown and will vary depending on bore size and table infrastructure. Image noise, particularly in large horses and beam hardening artefacts from hardware and pelvis degraded image quality. Images were of insufficient quality in large horses for soft tissue interpretation.ConclusionCT of the caudal spine and pelvis in live horses with wide-bore CT machines and modified patient infrastructure was safe and produced diagnostic images. HintergrundDie Querschnittsbildgebung verbessert die diagnostische Genauigkeit von komplexen anatomischen Regionen. Die Computertomographie (CT) des Beckens und der kaudalen Wirbels & auml;ule bei einer gro beta en Gruppe lebender Pferde und Ponys wurde bisher noch nicht berichtet.Ziel der StudieBeschreibung des Verfahrens zur Aufnahme von CT-Bildern der kaudalen Wirbels & auml;ule/des Beckens von Pferden unter Vollnarkose und detaillierte Beschreibung der Bildqualit & auml;t, Artefakte und anatomischen Variationen in diesen Regionen.StudiendesignRetrospektive Fallserie.MethodikPferde mit CT der kaudalen Wirbels & auml;ule/des Beckens wurden in die Studie aufgenommen. Pferde, die j & uuml;nger als 6 Monate waren und bei denen die CT-Untersuchung postmortal durchgef & uuml;hrt wurde, wurden ausgeschlossen. Analysiert wurden Protokolle, Bildqualit & auml;t, Interessengebiet, anatomische Merkmale und Morbidit & auml;ten.ErgebnisseSechsundf & uuml;nfzig Pferde (8 Monate bis 20 Jahre, 85-680 kg) erf & uuml;llten die Einschlusskriterien. Die Dauer der Vollnarkose (GA) lag zwischen 10 und 60 Minuten (Mittelwert 30, Median 32). Bei keinem der Pferde wurden unerw & uuml;nschte Ereignisse im Zusammenhang mit dem Verfahren festgestellt. Die Bilder aller Pferde waren von diagnostischer Qualit & auml;t. Anatomische Abweichungen waren h & auml;ufig und betrafen u.a.: die Lage des divergierenden (breitesten) Zwischenwirbelraums, das Vorhandensein einer Spina bifida in der Lenden- und Sakralwirbels & auml;ule, die Form des letzten Lendenwirbels und die Lage der Intertransversalgelenke in Bezug auf deren Vorhandensein und den Grad der Fusion/Modellierung.Haupteinschr & auml;nkungenNicht bei allen Pferden wurden die gleichen Regionen im CT untersucht, die Obergrenze f & uuml;r die Gr & ouml;beta e der Pferde ist unbekannt und h & auml;ngt von dem Gantrydurchmessers und der Tischkonstruktion ab. Bildrauschen, insbesondere bei gro beta en Pferden, und Strahlenh & auml;rtungsartefakte von Hardware und Becken beeintr & auml;chtigten die Bildqualit & auml;t f & uuml;r die Interpretation von Weichteilen.SchlussfolgerungDie Computertomographie der kaudalen Wirbels & auml;ule und des Beckens bei lebenden Pferden mit Wide-Bore-CT-Ger & auml;ten und modifizierter Patienteninfrastuktur war sicher und lieferte diagnostische Bilder.

SummaryCommon pathology within the digital flexor tendon sheath (DFTS) includes tearing of the manica flexoria, marginal longitudinal lesions of the deep digital flexor tendon and fetlock canal constriction. These are a frequent cause of lameness in cob‐type breeds where skin thickness can make obtaining diagnostic ultrasound images difficult. Radiographic contrast tenography in the standing patient can be used to identify pathology but provides limited information on the exact lesion configuration. This report describes the use of computed tomographic contrast tenography under general anaesthesia to identify and detail the configuration of intrathecal DFTS pathology in four clinical cases (six limbs) subsequently assessed with DFTS tenoscopy. Computed tomography findings altered surgical planning in two cases, and in all cases computed tomography findings were confirmed by tenoscopy. Computed tomographic contrast tenography correctly predicted all lesions observed during tenoscopy: manica flexoria pathology including laterality (4/4 torn and 2/2 intact), fetlock canal constriction (3/3 limbs), deep digital flexor tendon injury (1/1) and intrathecal adhesions (5/5 limbs). Computed tomographic contrast tenography was a useful pre‐operative imaging modality which aided surgical planning. The technique may be applicable for use in standing computed tomography systems where it would provide the diagnostic benefits listed without the associated risk of prolonging anaesthesia.

Sacroiliac dysfunction (SID) is a condition seen in horses associated with poor performance that affects hind limb gait and impulsion. The condition comprises pain and dysfunction but there lacks clarity around the aetiopathogenesis and whether SID encompasses abnormal joint pathology, abnormal joint movement, abnormal regional biomechanical function, joint laxity and pain, or various combinations of these that may vary over time. Clinical assessment remains challenging for equine clinicians due to the deep location of the sacroiliac joint (SIJ) and surrounding structures which limits access for palpation, diagnostic imaging and joint-specific injection. There is no recognised single reference standard diagnostic test for SID. Clinical diagnosis has been based on ruling out other causes of hind limb lameness, along with combinations of ultrasonography, scintigraphy and periarticular anaesthesia of the SIJ. Recent studies have highlighted the lack of specificity of injections targeting the SIJ, with significant dispersal of injectate into surrounding structures including around the lumbosacral joint (LSJ). Advanced imaging modalities such as computed tomography offers promise for assessment of the structure and pathology of the SIJ and surrounding bony structures. However, there is a need to improve the understanding of the significance of anatomic variation of the sacroiliac region structures, with recent studies reporting detailed anatomic variation in groups of horses with and without SID. There are also limitations around functional assessment of the joint which is still largely reliant on a thorough clinical examination. This review aims to present an update on clinical approaches to the diagnosis of horses with SID, and to consider the challenges and limitations.

ObjectiveTo determine the outcome of tenoscopically guided palmar/plantar annular ligament (PAL) desmotomy to treat PAL constriction without concurrent intrathecal soft-tissue injury, notably of the digital flexor tendons and manica flexoria. Study designRetrospective multicenter cohort study. AnimalsSixty-five horses. MethodsHorses from four UK equine hospitals, with digital flexor tendon sheath (DFTS) tenosynovitis, which underwent tenoscopically guided PAL desmotomy for treatment of PAL constriction between 2017 and 2022 were included. All horses had lameness isolated to the DFTS/PAL, and PAL constriction was diagnosed tenoscopically when there was difficulty maneuvering the endoscope into or through the fetlock canal. Horses with tearing of the digital flexor tendons and/or manica flexoria, or any other intrathecal pathology, were excluded. Follow up was via structured telephone questionnaire. ResultsFollow up (median 25 months) was available for 61 horses with cobs and ponies predominating. Forty-two returned to their previous level of work, or a higher level, postoperatively and 50 owners were satisfied with the outcome of surgery. Eleven horses returned to lower level exercise, and six were retired/euthanized as they did not regain soundness. Fifty-two horses achieved soundness (median 3 months postoperatively). ConclusionTenoscopically guided PAL desmotomy for the treatment of PAL constriction in the absence of intrathecal soft tissue injury had a good prognosis for return to previous levels of exercise in a UK horse population. Clinical significanceThe prognosis for horses undergoing tenoscopically guided PAL desmotomy to treat PAL constriction in the absence of intrathecal injury is better than previously described. Cobs and ponies seem to be predisposed to PAL constriction in agreement with the previous literature.

SummaryBackgroundThe digital flexor tendon sheath (DFTS) is a common site of pathology in the UK equine population, often necessitating tenoscopic exploration. Common intrathecal pathologies may lead to fetlock canal constriction. The palmar/plantar annular ligament (PAL) is often surgically transected to relieve constriction or to facilitate surgical access and instrumentation.ObjectivesThe objectives of this study were (1) to establish whether diagnostic quality needle tenoscopy can be achieved in the proximal DFTS in cadaver limbs; (2) to determine if needle tenoscopy can be used to safely guide PAL transection; and (3) to evaluate iatrogenic damage when undertaking needle tenoscopy and PAL transection.Study designEx vivo experimental.MethodsSix cadaveric limbs were used and needle tenoscopy of the DFTS was performed via biaxial approach at the base of the sesamoids. Access to and diagnostic assessment of the proximal DFTS, as well as the completeness of needle tenoscopically guided transection of the PAL was recorded. Limbs were dissected and examined for iatrogenic damage and completion of PAL transection.ResultsPositioning of the cannula/obturator unit was achieved on the first attempt 11/12 times. Laterally 16/24 and medially 18/24 proximal DFTS channels were accessed. Images were of diagnostic quality in 12/24 and 11/24 channels following lateral and medial approach, respectively. The PAL was completely transected in 4/6 limbs with partial transection in 1/6 limbs. The superficial digital flexor tendon (SDFT) was longitudinally lacerated instead of the PAL in one limb, with other iatrogenic damage limited to mild fibrillation to the intersesamoidean ligament.Main limitationsEx vivo and sample size.ConclusionsThe findings in this pilot study suggest that needle tenoscopically guided PAL transection in the live horse is not recommended currently. While diagnostic needle tenoscopy offered partial assessment of most of the proximal DFTS, further refinement is necessary before needle tenoscopy could be considered a viable alternative to traditional tenoscopy.

SummaryThis case report describes the diagnosis and arthroscopic removal of a ruptured epidermoid cyst in a distal interphalangeal (DIP) joint of a horse. The cyst was the cause of chronic moderate lameness and following removal the horse returned to athletic performance. However, 12 months postoperatively the horse was retired due to the recurrence of lameness. Epidermoid cysts have been diagnosed elsewhere in the equine digit but have not been reported intra‐articularly to the best of our knowledge.

A 3-week-old pedigree British blue bull, weighing 70 kg, presented with soft tissue swelling of the distal left forelimb, with a discharging sinus associated with a granulating wound (pressure sore). Involvement of the metacarpophalangeal joint was suspected. There were also granulating wounds on the dorsal aspect of both metacarpophalangeal joints and laterally on both tarsi. Radiography, arthrocentesis, arthroscopy and joint lavage were carried out under general anaesthesia and the external wounds were debrided and dressed. Intra-articular antibiotics were given at the time of surgery and systemic antibiotics and anti-inflammatories were given for 14 days afterwards. The calf made a good recovery and returned to normal function.

OBJECTIVE:To describe the surgical treatment, postoperative management, and outcome of a miniature horse undergoing total hip arthroplasty (THA).STUDY DESIGN:Case report.ANIMALS:A 4-year-old miniature horse stallion weighing 85 kg.METHODS:The horse presented with left coxofemoral luxation of ~6 weeks duration. Computed tomography confirmed craniodorsal luxation with marked degenerative changes to the femoral head. The horse underwent THA using cementless press fit implants, including an interlocking lateral bolt for the femoral stem.RESULTS:The horse recovered well from anesthesia but suffered a coma-like episode after returning to a stable. Following treatment of presumed hypovolemia, the horse regained normal mentation and was discharged 24 days after surgery. At reassessment 12 weeks postoperatively, the horse was 2/10 left hind limb lameness at trot with good healing of the surgery site. Five months postoperatively mild (1/10) lameness remained at trot but the horse was able to canter normally on both reins. The horse has since been managed normally with no veterinary treatment required for 32 months postoperatively.CONCLUSION:Total hip arthroplasty is possible in miniature horses weighing up to 85 kg and can result in a good long-term outcome.

Osteomyelitis in adult horses, often associated with trauma or iatrogenic infection following surgery, usually presents as a focal area of infected bone. Diffuse osteomyelitis, affecting both the cortex and medulla, along the full length of a bone is encountered less frequently and treatment of such infections is not well reported in horses. The 2-year-old Warmblood mare in this case was diagnosed with diffuse osteomyelitis affecting the 4th metacarpal bone with concurrent unicortical fracture of the third metacarpal bone following traumatic injury. Computed tomography (CT) aided diagnosis in this case, providing critical additional detail to that obtained with radiography and ultrasound. This case highlights the value of CT in the diagnosis of diffuse osteomyelitis. This is the first reported case of diffuse osteomyelitis caused by Clostridium perfringens in horses. Successful treatment in this case consisted of surgical debridement of the associated abscess, followed by systemic and locoregional antimicrobial therapies.

Owing to their superficial position on the lower limb, close approximation to the suspensory ligament and rather insubstantial nature, it is unsurprising that splint bone fractures are commonly encountered in practice. These fractures can be caused by either external or internal trauma, and can take a number of configurations. Treatment and prognoses differ depending on the location, configuration and age of the fracture, as well as involvement of adjacent soft tissue structures, the third metacarpal or metatarsal bone, or the carpometacarpal or tarsometatarsal joints. However, despite the frequency of splint bone fractures, there is no consensus regarding appropriate treatment. Management consists of conservative or surgical strategies, both of which have distinct advantages and disadvantages. Most reports consist of small case series and clinical experience. This review article presents current information and guidance for managing splint bone fractures.

Validated assessment protocols have been developed to quantify welfare states for intensively managed sport, pleasure, and working horses. There are few protocols for extensively managed or free-roaming populations. Here, we trialed welfare indicators to ascertain their feasibility, reliability, and repeatability using free-roaming Carneddau Mountain ponies as an example population. The project involved (1) the identification of animal and resource-based measures of welfare from both the literature and discussion with an expert group; (2) testing the feasibility and repeatability of a modified body condition score and mobility score on 34 free-roaming and conservation grazing Carneddau Mountain ponies; and (3) testing a prototype welfare assessment template comprising 12 animal-based and 6 resource-based welfare indicators, with a total of 20 questions, on 35 free-roaming Carneddau Mountain ponies to quantify inter-assessor reliability and repeatability. This pilot study revealed that many of the indicators were successfully repeatable and had good levels of inter-assessor reliability. Some of the indicators could not be verified for reliability due to low/absent occurrence. The results indicated that many animal and resource-based indicators commonly used in intensively managed equine settings could be measured in-range with minor modifications. This study is an initial step toward validating a much-needed tool for the welfare assessment of free-roaming and conservation grazing ponies.

The sacroiliac joint and pain deriving from this complex region remains poorly understood in horses, although our understanding grows as the body of literature grows. A deeper understanding can be derived from the richer body of literature in human sacroiliac joint pain as the disease processes and biomechanics appear similar in both species. A highly specific and sensitive diagnostic test for this condition does not exist, so equine clinicians have to make presumptive diagnosis based on presenting signs, findings of clinical examination, diagnostic imaging and the response to blocking of the sacroiliac joint region. Many horses with sacroiliac joint region pain have concurrent orthopaedic injury or disease. Treatment is largely based on fundamentals, anecdotal evidence and translation of non-surgical techniques used in humans. Treatment for other orthopaedic conditions can conflict with rehabilitation for sacroiliac joint region pain, necessitating compromise.

BACKGROUND:Accuracy of intrasynovial injections can be challenging to assess in a clinical setting in horses. Contrast-enhanced ultrasonography (CEUS) using injectate agitated with air has been used to determine the success rates of synovial injections in human rheumatology.OBJECTIVES:To assess the diagnostic sensitivity and specificity of CEUS and to describe its clinical use.STUDY DESIGNS:Cadaveric study followed by a prospective descriptive observational study.METHODS:Part 1: CEUS was performed following injection of agitated methylene-blue solution targeting 13 different anatomical synovial structures from three equine cadavers. Contrast was seen as hyperechoic dots, patches or lines on ultrasonography. CEUS was classified as positive if contrast was considered to be intrasynovial and negative if contrast was considered to be extrasynovial. A second synoviocentesis was performed to determine if the injection was intrasynovial based on the presence or absence of methylene-blue. Estimates of sensitivity and specificity were calculated. Part 2: CEUS was performed following injection of agitated solutions targeting synovial structures as part of routine investigation and treatment of clinical cases.RESULTS:Part 1: CEUS was correctly classified as positive or negative in all intrasynovial and extrasynovial injections respectively. The sensitivity estimate was 100% (CI 93%-100%) and the specificity estimates was 100% (CI 16%-100%). Part 2: The technique was used safely for 26 injections (14 horses; 19 different synovial structures) administered to localise or treat lameness. Traumatic intersynovial communications or synovial membrane defects were identified using CEUS in 3 horses.MAIN LIMITATIONS:The low number of extrasynovial injections in Part 1 resulted in an imprecise specificity estimate.CONCLUSIONS:In horses, CEUS performed following intended intrasynovial injection can be useful for identifying unsuccessful injections.

Identification and characterization of foreign bodies in the distal limb of horses poses a diagnostic challenge. The aims of this prospective experimental cadaver study were to describe the appearance of five foreign body materials within the equine hoof using CT, MRI, and digital radiography (DR) and to compare interrater agreement among three reviewers. Fifty foreign bodies consisting of five materials were implanted at a solar location or a coronary location in 25 equine cadaver feet. The images were reviewed by three equine veterinarians experienced in advanced imaging interpretation, who were blinded to the material of the foreign body. Foreign bodies were graded on visibility and appearance. Sensitivity and specificity were calculated for accurate identification of the different materials. Interrater agreement was assessed using Fleiss' kappa. Computed tomography had higher visibility score, sensitivity/specificity, and interrater agreement for detection of all materials; particularly slate, glass, and dry wood, compared to the other imaging modalities. Soaked wood and plastic had lower sensitivity (31-33%) on CT with a similar attenuation of the two materials. Foreign bodies were often visible on MRI, although with similar appearance and unclear details. On DR, only slate and glass were visible. The interrater agreement for identifying the correct material was almost perfect for slate, glass, and dry wood (κ = 0.92-1.00) and poor for plastic and soaked wood (κ < 0.20) on CT. Interrater agreement was poor for all materials on MRI and DR (κ < 0.20), with the except for fair (κ = 0.28) for slate on DR and moderate (κ = 0.28) for soaked wood on MRI.

Housing bachelor groups is a necessary aspect of the care and husbandry of non-breeding individuals in zoological collections. Intraspecific aggressive behaviors may occur in this setting despite management strategies designed to mitigate these behaviors. Androgens (including testosterone) are associated with aggression in male species and interventional techniques to alter the animals' physiology to modify aggressive behavior are sometimes required. When agonistic behavior and physical aggression in two mature male Amur leopards housed together at Tayto Park escalated, despite all strategic management involvements, further intervention to moderate aggression was required. The gonadotropin-releasing hormone (GnRH) agonist, deslorelin, has been found to be effective in reducing androgens in domestic and non-domestic carnivores. We hypothesized that deslorelin's suppressive effect on hypothalamic-pituitary-gonadal axis would mitigate intraspecific aggression in two male intact leopards. Behavioral observations were carried out pre- and post-implant implantation of 9.4 mg deslorelin implant. The frequency of agonistic/aggressive behaviors for both leopards declined significantly (p < 0.05), as did marking behaviors post-implantation (p < 0.001). The insertion of deslorelin implants in two male intact leopards demonstrating increased frequency and severity of aggressive behaviors resulted in a reduction of the frequency of these behaviors. Deslorelin implantation should be considered for management of interspecific aggression of intact male leopards in bachelor groups.

Synovial fluid analysis is utilized to diagnose septic synovitis. However, not all cases are clearly and rapidly discernible with the diagnostic tools available in the laboratory. Serum amyloid A (SAA), an acute phase protein, has been shown to be elevated in synovial fluid from inflamed synovial structures. The goal of this study is to describe the correlation between two diagnostic tests measuring equine SAA levels in septic and non-septic synovial structures and to understand the correlation between an elevated SAA result and synovial sepsis. Prospective estimation of sensitivity (Se) and specificity (Sp) of two tests, handheld and ELISA, measuring SAA in synovial fluid was completed in 62 horses presented with injured synovial structures. The comparison was made to a reference diagnosis based on white cell count, percentage of neutrophils, intracellular bacteria and bacterial culture on synovial fluid. Handheld test levels were classified as: 4 lines visible—SAA level negative; 3 lines visible—SAA level mild; 2 lines visible—SAA level moderate; and 1 line visible—SAA level severe and compared to the numerical value obtained with ELISA test. The ELISA SAA test had an area under the curve of 0.88 (0.78–0.98). An ELISA cut-off of 23.95 μg/mL maximized Se and Sp. This cutoff gave a Se of 0.93 (0.66–1.00) and Sp of 0.77 (0.63–0.88). The handheld test was highly correlated with the ELISA SAA test (Spearman rank correlation 0.96) and at a cutoff of moderate or higher for positive results gave identical Se and Sp. Se and Sp of synovial fluid SAA are very reliable when clinical signs of synovitis are present for >6 h. This test, in conjunction with traditional methods, can assist practitioners to rapidly diagnose and expedite appropriate intervention of synovial sepsis.