Evaluation of a New Surgical Treatment for Equine Hind Limb Proximal Suspensory Desmitis.

OBJECTIVE: To evaluate the effects of a new microfracture and ligament splitting procedure on ligament healing and to examine the usefulness of magnetic resonance (MR) imaging for monitoring ligament healing over time using a collagenase model of hind limb proximal suspensory desmitis. STUDY DESIGN: Experimental in vivo study. ANIMALS: Healthy adult horses (n=6). METHODS: Horses were free of lameness with normal hind limb proximal suspensory ligaments (PSL). The origin of both hind limb PSL was injected with collagenase and underwent MR imaging 2 weeks later, followed by the microfracture and ligament splitting procedure on 1 limb, with the opposite limb serving as the sham-operated control. Serial lameness and MR examinations were performed. Horses were euthanatized 210 days after surgery, the PSL harvested, and histology, biochemistry, and gene expression performed on both PSL. RESULTS: Collagenase lesions viewed on MR images appeared similar to those seen clinically. Serial MR images demonstrated resolution of abnormal signal intensity and tissue formation in the microfracture sites within the third metatarsal bone. Treated limbs had histologic evidence of connective tissue appearing to originate from the small perforations and blending into the ligament but no statistical differences were identified. Gene expression for cartilage oligomeric matrix protein and decorin were significantly increased in treated compared to control limbs. CONCLUSION: The microfracture and ligament splitting procedure did incite a tissue response but further clinical investigation is necessary to determine if this tissue remodeling at the bone-ligament interface translates to improved clinical outcome. MR imaging may be useful to follow healing in horses with hind limb proximal suspensory desmitis.

Clinical outcome after intra-articular administration of bone marrow derived mesenchymal stem cells in 33 horses with stifle injury.

OBJECTIVE: To report outcome of horses with femorotibial lesions (meniscal, cartilage or ligamentous) treated with surgery and intra-articular administration of autologous bone marrow derived mesenchymal stem cells (BMSCs). STUDY DESIGN: Prospective case series. ANIMALS: Horses (n = 33). METHODS: Inclusion criteria included horses that had lameness localized to the stifle by diagnostic anesthesia, exploratory stifle arthroscopy and subsequent intra-articular administration of autologous BMSCs. Case details and follow-up were gathered from medical records, owner, trainer or veterinarian. Outcome was defined as returned to previous level of work, returned to work, or failed to return to work. RESULTS: Follow-up (mean, 24 months) was obtained; 43% of horses returned to previous level of work, 33% returned to work, and 24% failed to return to work. In horses with meniscal damage (n = 24) a higher percentage in the current study (75%) returned to some level of work compared to those in previous reports (60-63%) that were treated with arthroscopy alone, which resulted in a statistically significant difference between studies (P = .038). Joint flare post injection was reported in 3 horses (9.0%); however, no long-term effects were noted. CONCLUSIONS: Intra-articular administration of BMSC postoperatively for stifle lesions appeared to be safe, with morbidity being similar to that of other biologic agents. Improvement in ability to return to work may be realized with BMSC treatment compared to surgery alone in horses with stifle injury.

Response to injection of the navicular bursa with corticosteroid and hyaluronan following high-field magnetic resonance imaging in horses with signs of navicular syndrome: 101 cases (2000-2008).

OBJECTIVE: To determine treatment outcome on the basis of pathological changes identified on MRI and lameness duration in horses with navicular syndrome that underwent injection of corticosteroid and hyaluronan into the navicular bursa. DESIGN: Retrospective case series. ANIMALS: 101 horses with navicular syndrome. PROCEDURES: Medical records of horses with signs of navicular syndrome evaluated between January 2000 and December 2008 were reviewed. Data on signalment, use of the horse, history, affected limbs, duration of lameness, findings on lameness examination, radiographic findings, MRI findings, treatment, and outcome were collected from the medical records. Follow-up information was obtained a minimum of 10 months after navicular bursa injection. RESULTS: Following navicular bursa injection, 76 of 101 (75%) horses returned to their intended use for a mean of 9.66 months, and 35 (35%) were sound at follow-up. Horses that had been lame for < 6 months before treatment were significantly more likely to return to their intended use, have a longer positive response to treatment, and be sound at follow-up, compared with horses that had a longer lameness history. Horses with primary deep digital flexor (DDF) tendonitis responded best to navicular bursa injection with rest and rehabilitation, followed by horses with navicular bursitis and horses with DDF tendonitis and adhesions to the collateral sesamoidean ligament of the distal sesamoid (navicular) bone. Horses with scar tissue in the proximal portion of the navicular bursa, adhesions from the navicular bone to the DDF tendon, or multiple abnormalities did not respond as well to treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Response to navicular bursa injection with corticosteroid and hyaluronan in horses with navicular syndrome was dependent on the disease process detected on MRI and duration of lameness.

Desmotomy of the accessory ligament of the deep digital flexor tendon in the forelimb of 24 horses 2 years and older.

OBJECTIVE: To report outcome after desmotomy of the accessory ligament of the deep digital flexor tendon (ALDDFT) in adult horses (≥2 years) for treatment of desmitis of the ALDDFT or flexural deformity of the distal interphalangeal joint (FDDIJ). STUDY DESIGN: Case series. ANIMALS: Horses with desmitis of the ALDDFT (n=9) and FDDIJ (n=15). METHODS: Records (April 1996-July 2008) of 24 adult horses (mean age, 6.7 years) that had ALDDFT desmotomy were reviewed. Follow-up data was obtained 12-120 months after desmotomy. RESULTS: Outcome was available for 22 horses; 18 (82%; 6 of 8 horses with desmitis of the ALDDFT and 12 of 14 with FDDIJ) returned to their intended use within 6-24 months (mean, 12 months). CONCLUSION: In mature horses, ALDDFT desmotomy resulted in successful return to intended use in most horses with ALDDFT desmitis (75%) or FDDIJ (86%).

Intrathecal deep digital flexor tenectomy for treatment of septic tendonitis/tenosynovitis in four horses.

OBJECTIVE: To describe partial removal of the intrathecal component of the deep digital flexor tendon (DDFT) in horses with chronic septic DDF tendonitis and tenosynovitis unresponsive to conventional therapy, and to report long-term outcome. STUDY DESIGN: Case series. ANIMALS: Horses (n=4). METHODS: Four horses with chronic septic DDF tendonitis and tenosynovitis were treated by surgical tenectomy of the intrathecal component of the DDFT, followed by stabilization in casts and subsequent corrective shoeing. All horses were previously managed unsuccessfully with combinations of conventional therapy consisting of systemic antibiotics, through and through tendon sheath lavage/open drainage, regional limb perfusions, tenoscopy with debridement and transection of the palmar/plantar annular ligament, and intrathecal antibiotics. RESULTS: Time from initial injury/diagnosis to tenectomy ranged from 10 to 210 days. Mean hospitalization time after surgery was 82 days. Long-term follow-up (>1.5 years; mean, 3.8 years) was available. All 4 horses were able to walk comfortably at pasture and were used as broodmares. CONCLUSIONS: Intrathecal tenectomy is a viable surgical procedure for treatment of chronic septic tenosynovitis of the digital sheath that is complicated by septic tendonitis of the DDFT.

Evaluation of an arthroscopic approach for transection of the equine collateral sesamoidean ligament.

OBJECTIVE: To evaluate: (1) an arthroscopic technique for transection of the collateral sesamoidean ligament (CSL); and (2) the healing response using magnetic resonance (MR) and microscopic examination. STUDY DESIGN: Experimental study. ANIMALS: Adult horses (n=6). METHODS: Six sound horses with normal front foot radiographic and MR examinations were used. Lameness examination was performed before surgery and monthly for 12 months. Front foot radiography was performed at 180 and 360 days after surgery. Front foot MR was performed before, and at 7, 90, 180, and 360 days after surgery. Arthroscopic CSL desmotomy was performed on 1 forelimb. Gross and microscopic examination was performed on the CSL from both forelimbs at 360 days after surgery. Lameness scores were compared over time using the nonparametric Friedman's test for paired groups. CSL measurements were compared using paired t-tests with a 2-tailed significance level of P<.05. RESULTS: Radiographs remained normal throughout study period. Surgery resulted in lameness on the operated limb for up to 2 months, after which all horses returned to soundness. CSL transection was confirmed during arthroscopy and with MR examination 7 days after surgery. Gross and microscopic evaluation confirmed ligament healing. CONCLUSIONS: CSL desmotomy resulted in short-term lameness after surgery followed by healing of the CSL confirmed by gross and microscopic analysis.

Desmitis of the distal digital annular ligament in seven horses: MRI diagnosis and surgical treatment.

OBJECTIVE: (1) To describe the clinical signs and abnormalities observed on magnetic resonance imaging (MRI) in 7 horses with desmitis of the distal digital annular ligament (DDAL); (2) to describe the normal magnetic resonance (MR) appearance and thickness of the DDAL in health; and (3) to describe a tenoscopic surgical technique for treating horses with desmitis of the DDAL. STUDY DESIGN: Retrospective study. ANIMALS: Horses (n=7) with desmitis of the DDAL. METHODS: MR examinations of 20 sound horses were reviewed to determine the normal appearance of the DDAL. Dimensions obtained from these images were compared with MR findings from 7 horses with DDAL desmitis. Desmitis of the DDAL was treated by tenoscopic surgery and outcome assessed. RESULTS: Horses with DDAL desmitis had lameness (grade 2-3 out of 5) that improved after a palmar digital nerve block. The affected DDAL was enlarged and had an abnormal signal on MR images of the feet. After tenoscopy and DDAL transection, 5 horses returned to athletic performance, including 2 horses that failed to respond to medical treatment and rest before surgery. CONCLUSION: Primary desmitis of the DDAL is a cause of lameness in horses. Transection of the DDAL allowed 5 horses with this injury to return to athletic performance. CLINICAL RELEVANCE: DDAL desmitis should be included in the differential diagnoses of horses with lameness that improves after a palmar digital nerve block but have no abnormalities observed on radiographs of the feet. Tenoscopic surgical transection of the DDAL is an effective treatment for some horses.

Surgical approach for removal of nonarticular base sesamoid fragments of the proximal sesamoid bones in horses.

OBJECTIVES: To describe a surgical approach for the removal of nonarticular base sesamoid fragments in performance horses and to report the outcome. STUDY DESIGN: Retrospective study. ANIMALS: Horses (n=11), 7 months to 10 years of age, with lameness because of nonarticular base sesamoid fragments. METHODS: Lameness was localized to the metacarpophalangeal/metatarsophalangeal region by clinical examination or response to diagnostic local anesthesia. Radiographs confirmed the diagnosis of a nonarticular base sesamoid fragment. Surgical removal was performed with an incision over the base of the affected sesamoid through the digital flexor tendon sheath. After identifying the fragment with the aid of needles, a small vertical incision was made in the straight distal sesamoidean ligament (SDSL) and the fragment was freed from its attachments and removed. Six months convalescence and rehabilitation was prescribed for all horses. RESULTS: Eleven horses had 16 nonarticular fragments of the base of the proximal sesamoid bones. Eleven (69%) fragments occurred in the forelimbs with the right front (82%) and medial sesamoid (73%) more commonly affected. Horses were treated by surgical fragment removal. In horses with follow-up, 9 of 10 returned to their intended use. CONCLUSIONS: Surgical removal of nonarticular base sesamoid fragments can be accomplished through a palmar/plantar approach through the digital flexor tendon sheath and SDSL. This "keyhole" approach minimizes damage to the distal sesamoidean ligament attachments to the sesamoid base and allows some horses to return to their intended use. CLINICAL RELEVANCE: Surgical removal of nonarticular base sesamoid fragments should be considered in horses with performance-limiting lameness as a result of the fragment.

Detection of an epidermoid cyst in the foot of a horse by use of magnetic resonance imaging.

CASE DESCRIPTION-A 4-year-old Quarter Horse stallion was evaluated because of a 10-month history of moderate (grade 3/5) left forelimb lameness (detectable during trotting over a smooth, hard surface). CLINICAL FINDINGS-No abnormalities were detected in either forelimb via palpation or application of hoof testers; however, lameness was eliminated after administration of a palmar digital nerve block in the left forelimb. Whereas radiography and ultrasonography did not identify any left forelimb foot abnormalities, magnetic resonance (MR) imaging revealed a circumscribed soft tissue mass in the distal aspect of the digital flexor tendon sheath (DFTS) dorsal to the lateral aspect of the deep digital flexor tendon. Subsequently, the left forelimb DFTS was injected with local anesthetic, which resulted in 90% improvement of the horse's lameness. TREATMENT AND OUTCOME-The distal aspect of the left forelimb DFTS was evaluated tenoscopically. The mass was removed under tenoscopic guidance, after which the distal digital annular ligament was transected. The horse received phenylbutazone orally for 10 days, and the left forelimb DFTS was injected with hyaluronic acid and methylprednisolone acetate 7 days after the surgery. Following a rehabilitation program, the horse was returned to full training at 6 months after surgery and competed successfully during a 2-year follow-up period. CLINICAL RELEVANCE-Use of MR imaging should be considered in all lame horses for which a definitive diagnosis cannot be made via radiography, ultrasonography, or other imaging techniques, especially when the lameness has been localized to a specific anatomic region by use of diagnostic anesthesia.

Comparison of three methods for arthrodesis of the distal intertarsal and tarsometatarsal joints in horses.

OBJECTIVE: To evaluate the effects of diode laser surgery (LS), surgical drilling (SD), and intraarticular sodium monoiodoacetate (MIA) as methods for fusing the distal intertarsal (DIT) and tarsometatarsal (TMT) joints in horses. STUDY DESIGN: Experimental study. ANIMALS: Adult horses (15) without radiographic signs of osteoarthritis (OA) of the DIT and TMT joints. METHODS: Group 1 (n=3) had LS performed bilaterally on DIT and TMT joints; 1 horse was evaluated for 1 week and 2 horses were evaluated for 2 weeks. Group 2 (n=6) had LS on DIT and TMT joints of 1 tarsus and MIA administration into the contralateral DIT and TMT joints and were evaluated for 6 months. Group 3 (n=6) had LS performed on DIT and TMT joints of 1 tarsus and SD of the contralateral DIT and TMT joints and were evaluated for 12 months. Postoperative comfort, lameness, radiography, microradiography, and histology scores were compared using repeated measures ANOVA, and paired or 2 sample t-tests; significance was set at P<.05. RESULTS: LS caused the least postoperative morbidity. In group 2, horses were less lame in 4 LS-treated limbs and 2 MIA-treated limbs at 6 months when compared with the contralateral limb. In group 3, horses were less lame in 5 LS-treated limbs and 1 SD-treated limb at 6 and 12 months compared with the contralateral limb. On microradiography, 11 MIA joints and 2 LS joints had bone bridging the joint at 6 months whereas 8 SD joints and 5 LS joints had bone bridging at 12 months. Significantly more joint space was bridged by bone in MIA- (51.4%) and SD (46.2%)-treated joints compared with LS joints at 6 (30.6%) and 12 (28.5%) months, respectively (P<.05). CLINICAL RELEVANCE: SD and MIA resulted in more bone bridging of the distal 2 tarsal joints, than LS. However, LS seemingly caused less pain and discomfort to horses in the immediate postoperative period; horses were generally less lame in the LS limb. More laser energy may need to be applied to these joints to promote fusion; however, it may also have beneficial effects beyond fusion. Further research on horses with OA of the distal 2 tarsal joints is needed to determine whether LS can cause soundness without facilitating bony fusion.

Septic arthritis and granulomatous synovitis caused by infection with Mycobacterium avium complex in a horse.

A 12-year-old American Saddlebred gelding was referred to a veterinary teaching hospital for evaluation of a chronic lameness problem in the right radiocarpal joint. The horse had been treated for osteoarthritis of the right radiocarpal joint with multiple injections of cortisone during the past 3 years. The horse was severely lame on the right forelimb at a trot. Radiography and computed tomography revealed a 3 x 2-cm lytic defect in the distal portion of the radius and periarticular bone proliferation around the right radiocarpal joint. Ultrasonography of the distal portion of the radius revealed a soft tissue mass in the palmarolateral aspect of the joint. Proliferative synovium with a large amount of fibrin was observed in the dorsal and palmar aspects of the joint via arthroscopic examination of the right radiocarpal joint. Histologic examination of synovial biopsy specimens revealed proliferative granulomatous synovitis with giant cells. Mycobacterium avium complex was cultured from the synovial fluid. Infection with M avium complex should be considered in horses with chronic recurring arthritis associated with granulomatous synovitis.

Use of magnetic resonance imaging identify suspensory desmitis and adhesions between exostoses of the second metacarpal bone and the suspensory ligament in four horses.

Four horses were examined because of chronic forelimb lameness. In all horses, the cause of the lameness was localized to the metacarpus by means of physical examination and diagnostic anesthesia, and radiography of the affected limb revealed a small exostosis of the second metacarpal bone. Magnetic resonance imaging revealed suspensory desmitis in the region of this exostosis in all 4 horses. In addition, an abnormal area of low signal intensity, suggestive of an adhesion, was seen between the exostosis and the suspensory ligament. In all horses, an adhesion between the suspensory ligament and the exostosis on the second metacarpal bone was identified and transected at surgery, and the exostosis and distal portion of the second metacarpal bone were removed. All horses were able to return to their previous athletic use following a 6-month rest and rehabilitation program for treatment of the suspensory desmitis. Findings in these horses suggest that adhesions between the suspensory ligament and an exostosis of the second metacarpal bone may be a cause of chronic or recurrent forelimb lameness in horses.

Use of magnetic resonance imaging for identifying subchondral bone damage in horses: 11 cases (1999-2003).

OBJECTIVE: To assess the use of magnetic resonance (MR) imaging for identifying subchondral bone damage in the distal limbs of horses. DESIGN: Retrospective study. ANIMALS: 11 horses. PROCEDURE: Medical records of horses with lameness and subsequent evidence of subchondral bone damage as determined by MR imaging were reviewed. Severity and duration of lameness, results of diagnostic local anesthesia and diagnostic testing, surgical and necropsy findings, and treatment were recorded. Outcome was determined by follow-up information obtained from the owner or referring veterinarian. RESULTS: Lameness was localized by physical examination and diagnostic local anesthesia. Lameness was localized to the metacarpophalangeal or metatarsophalangeal joint in 4 horses, distal interphalangeal joint in 5 horses, and tarsocrural joint in 2 horses. The duration of lameness ranged from 2 weeks to 20 months. Magnetic resonance imaging of the affected joints revealed abnormal fluid accumulation within the subchondral bone. None of the abnormalities observed by MR imaging were detected by radiography. Subchondral bone damage was diagnosed in all horses. Arthroscopy of the affected joint was performed in 4 horses. Communication with the articular surface of the affected bone was suspected on the basis of results of MR imaging in 4 horses and was confirmed by arthroscopy in 1 horse and by necropsy in 1 horse. CONCLUSIONS AND CLINICAL RELEVANCE: Magnetic resonance imaging was useful for providing a diagnosis when other imaging techniques did not definitively identify the cause of lameness. Subchondral bone damage was clearly identified by MR imaging and should be considered as a cause of lameness in horses in which radiographic findings are unremarkable.

Use of a hydro-pool system to recover horses after general anesthesia: 60 cases.

OBJECTIVE: To report complications observed using a hydro-pool recovery system after general anesthesia in horses. STUDY DESIGN: Retrospective study. ANIMALS: Sixty horses. METHODS: Retrospective review of the medical records and quality of recovery from anesthesia of 60 horses that had surgical or diagnostic procedures under general anesthesia. RESULTS: Mean total anesthesia time was 182 minutes (range, 25 to 390 minutes). Mean time in the hydro-pool was 108 minutes (range, 20 to 270 minutes). One horse that had bilateral rear limb extensor weakness while recovering in a padded recovery stall was moved to the hydro-pool and maintained for 12 hours. Ten horses developed some pulmonary edema; in 3 horses, the signs of pulmonary edema were severe; and 1 horse died from related complications. One horse developed septic arthritis of an operated stifle joint, and 2 horses developed incisional infections. Two horses incurred multiple skin abrasions on the distal aspect of their limbs during violent attempts to leave the pool. CONCLUSIONS: A hydro-pool system was useful for recovering horses from general anesthesia when difficult recoveries were anticipated because of the horse's injury, size, demeanor, duration of anesthesia, or risk of further injury. Recovery using the hydro-pool was more time and labor intensive than a standard stall recovery. Pulmonary edema that required treatment was a serious complication that occurred in 17% of the horses. Careful closure of the skin with cyanoacrylate glue and pressure from bandages were used to prevent postoperative incisional infections. CLINICAL RELEVANCE: A hydro-pool system is a useful method for recovering horses from general anesthesia when difficult recoveries are anticipated.

Psychiatric presentations of non-HIV infectious diseases. Neurocysticercosis, Lyme disease, and pediatric autoimmune neuropsychiatric disorder associated with streptococcal infection.

Infectious diseases can cause an array of symptoms, including psychiatric symptoms. Psychiatrists serving the medically ill need to be aware not only of classic infectious diseases (e.g., neurosyphilis and HIV), but also of less commonly discussed infectious diseases (e.g., NCC, PANDAS, and Lyme disease). These examples represent an internationally endemic disease (e.g., NCC), a probable immunogenetic disease (e.g., PANDAS), and a frequently overdiagnosed and overtreated disease (Lyme disease).