Digital Flexor Tendon Injuries Research Articles

Prognostic value of power doppler ultrasonography for equine superficial digital flexor tendon injury in thoroughbred racehorses

The potential value of hypervascularity detected with power Doppler ultrasonography (PDU) within equine superficial digital flexor tendon (SDFT) as a prognostic factor of SDFT injury is not clear. The purpose of this study was to test the hypothesis that hypervascularity within SDFT is one of the risk factors for subsequent severe SDFT injury and to evaluate the prognostic value. A prospective cohort study of 97 Thoroughbred racehorses without any clinical signs of SDFT injury was conducted. Six variables of age, body weight, sex, the cross-sectional area of SDFT, PDU signal within SDFT and experience of steeplechase were assessed for the possibility of risk factors of subsequent SDFT injury in follow-up period of 1 year. Multivariable logistic regression analyses were used for assessment of the odds ratios (ORs) and 95 % confidence intervals (CIs) of SDFT injury. Multivariable logistic regression analysis revealed that the PDU signal within SDFT was a risk factor for the development of SDFT injury in follow-up period (P = 0.017). The adjusted OR of SDFT injury was significantly higher in PDU positive group than in PDU negative group (OR 3.17, 95 % CIs 1.20–8.35). Although further studies are required, these results would be useful for early detection and/or prevention of development for clinical severe SDFT injury.

Safety assessment of equine allogeneic tenogenic primed mesenchymal stem cells in horses with naturally occurring tendon and ligament injuries.

Mesenchymal stem cells provide a valuable treatment option in orthopedic injuries in horses. The aim of this study was to evaluate the hematological, biochemical, immunological and immunomodulatory parameters following intralesional treatment with tenogenic primed equine allogeneic peripheral blood-derived mesenchymal stem cells (tpMSCs) in client-owned horses with naturally occurring superficial digital flexor tendon (SDFT) and suspensory ligament (SL) injuries. The immunogenicity and immunomodulatory capacities of tpMSCs were assessed in a modified mixed lymphocyte reaction, including peripheral blood mononuclear cells (PBMCs) of 14 horses with SDFT and SL injuries after treatment with tpMSCs. In a second study, 18 horses with SDFT and SL injuries received either an intralesional injection with tpMSCs (n = 9) or no treatment (n = 9). The tpMSCs did not provoke a cellular immune response (p < 0.001) and were able to immunomodulate stimulated T lymphocytes (p < 0.001) in vitro. Therapeutic use of tpMSCs did not result in relevant hematologic or biochemical abnormalities. Both studies had a small sample size. No statistical analyses were performed in the second study. Fibrinogen was only analyzed in a single horse prior to treatment. Co-incubation of tpMSCs and PBMCs of horses that have been previously exposed to tpMSCs did not elicit a cellular immune response and tpMSCs were able to immunomodulate stimulated T lymphocytes. Intralesional treatment with tpMSCs did not provoke abnormal changes in hematological and biochemical parameters.

Distal forearm squeeze test for the diagnosis of digital flexor tendon injuries

BackgroundThe forearm/wrist squeeze/compression test has been used to examine digital flexor tendon injuries with varied names. Furthermore, the test has not been minutely described and its mechanism remains unclear. We renamed the test the “distal forearm squeeze test”. The purpose of this study was to elaborate on the test and elucidate the mechanism.MethodsTwo patients with digital flexor tendons ruptured in zone 3 and zone 1 respectively and 50 outpatients with intact digital tendons underwent the test. Then the test was performed on 3 chickens under 4 conditions. First, when the digital flexor and extensor tendons were all intact. Second, after the flexor tendons of the third toe were transected. Third, after the flexor tendons of all toes of the foot were transected. Finally, after the flexor and extensor tendons of all toes of the foot were transected.ResultsIn the patient with digital flexor tendons ruptured in zone 3, the test showed that the injured digit was flexed slightly while the uninjured digits were flexed obviously. In the patient with digital flexor tendon ruptured in zone 1, after separate stabilization of the proximal interphalangeal (PIP) joints of the injured and uninjured fingers in extension, the test showed that the distal interphalangeal joint of the patient’s injured finger had no response, while those of the uninjured fingers were flexed. All 50 subjects showed clenched or half-clenched hands in response to the test. The test showed that all toes were flexed when the digital tendons of the chicken were intact. All toes were flexed except the third toe after the flexor tendons of the third toe were transected. All toes were extended after all the digital flexor tendons were transected. All toes had no response after all the digital flexor and extensor tendons were transected.ConclusionsThe distal forearm squeeze test is valuable in examining digital flexor tendon injuries. If only the flexor digitorum profundus tendon is examined, the PIP joint of the finger should be stabilized in extension during the test.

Computed tomographic contrast tenography aids pre‐operative diagnosis in clinical conditions of the digital flexor tendon sheath

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.

Equine allogeneic tenogenic primed mesenchymal stem cells: A clinical field study in horses suffering from naturally occurring superficial digital flexor tendon and suspensory ligament injuries.

Mesenchymal stem cells are an innovative therapeutic for various equine orthopaedic diseases, including soft tissue injuries. To evaluate the safety and efficacy of tenogenic primed equine allogeneic peripheral blood-derived mesenchymal stem cells (tpMSCs) in horses with naturally occurring superficial digital flexor tendon (SDFT) and suspensory ligament (SL) injuries. Multicentre, blinded, randomised, placebo-controlled clinical trial. One hundred client-owned horses with SDFT and SL injuries were randomised to receive an intralesional tpMSC (66) or saline (34) injection. Clinical and ultrasonographic evaluation was performed before treatment and on Days 56 ± 3 and 112 ± 3 after treatment. Long-term data on re-injury was collected up to 2 years after treatment. Significantly more tpMSC-treated horses achieved improvement in fibre alignment score (FAS) (100% vs. 54.5%, p < 0.001) and echogenicity (97.0% vs. 57.6%, p < 0.001) on Day 112 ± 3, and their lesion size decreased significantly (-27.6 ± 25.91 vs. -4.6 ± 26.64 mm2, p < 0.001) compared to the placebo group. A FAS = 0 was achieved in 65% of tpMSC-treated horses, as compared to 9% of placebo-treated horses at Day 112 ± 3. The attending veterinarians reported no re-injury in 41 of 53 tpMSC and in 2 of 26 saline-treated horses available for long-term follow-up (p < 0.001). As this study consisted of client-owned horses, no samples for histology were collected. Long-term follow-up was only available for a subset of enrolled horses. The intralesional administration of tpMSCs was safe and improved the quality of healing and long-term outcomes in sports horses with naturally occurring SDFT and suspensory injuries.

Mesenchymal stem cell licensing: enhancing MSC function as a translational approach for the treatment of tendon injury.

Tendon injuries are common in both veterinary and human clinical patients and result in morbidity, pain, and lost athletic performance. Consequently, utilizing naturally occurring injuries in veterinary patients as a comparative model could inform the development of novel therapies and increase translation for the treatment of human tendon injuries. Mesenchymal stem cells (MSCs) have shown considerable efficacy for the treatment of experimental and clinical superficial digital flexor tendon injury in the horse; however, the reinjury rate following treatment can remain high and MSC efficacy in treating other tendons is less well known. Additionally, the translation of MSC therapy to human tendon injury has remained poor. Recent evidence indicates that naïve MSC function can be enhanced through exogenous stimulation or manipulation of their environment. This stimulation or activation, herein termed MSC licensing, markedly alters MSC functions associated with immunomodulation, extracellular matrix remodeling, vascular development, bioactive factor production, and endogenous stromal/progenitor cell support. Additionally, a variety of licensing strategies has proven to influence MSC-secreted factors that have positively influenced outcome parameters in both in vitro and in vivo disease models separate from musculoskeletal tissues. Therefore, identifying the optimal licensing strategy for MSCs could ultimately provide an avenue for reliable and repeatable treatment of a broad range of tendon injuries of both veterinary and human clinical patients. This article details current evidence on the effects of licensed MSCs in both in vitro and in vivo disease models of different species and provides commentary on how those effector functions identified may be translated to the treatment of tendon injuries.

Research trends on digital flexor tendon: A bibliometric analysis based on CiteSpace

BackgroundA host of experts have shown interest in the digital flexor tendon. However, few have conducted a bibliometric analysis of this field. PurposeThis study aimed to carry out comprehensive and practical research on the academic status and the development trend in this area. MethodsAll papers regarding digital flexor tendons announced from 1991 to 2022 were retrieved and downloaded from the Web of Science Core Collection. CiteSpace was utilized to analyze the information on publication output, journals, authors, countries, institutions and keywords. ResultsA total of 3100 publications met the inclusion criteria, which were made up of articles and reviews. The publications and cite frequency increased rapidly per year (t = 10.652, P < 0.001; t = 19.716, P < 0.001). Journal of Hand Surgery American Volume had the largest number of studies (307 publications). Amadio PC was identified as the most prolific author, and Dyson SJ (336 citations) was the most cited author. The United States had the highest publications (35.39%), followed by England. Though Australia ranked tenth, which had the greatest impact (centrality = 0.43). This study collected 20 clusters and 25 citation bursts on the basis of keywords. ConclusionThis study recommends that international cooperation and linkages among authors, countries and institutions should be strengthened. Ultrasound, tenosynovitis, platelet-rich plasma, and 3-loop pulley suture have been the focus of current research. The surgical and non-surgical treatment of digital flexor tendon injury would be future frontiers.

The role of DMSO and MSM in treatment of tendinopathies affection in equine: A comparative study

Superficial digital flexor tendon (SDFT) injury is a main cause of lameness in polo and racehorses inciting long-term lameness and recovery. This study aimed to compare the efficacy of topical dimethyl sulfoxide (DMSO) and Methylsulfonylmethane (MSM) on bowed tendons in horses. Ten client-owned injured horses, aged between 5-15 years with an average age of 8.5 years and weighing approximately 400-500 kg, suffering from chronic tendinitis were selected and allocated into two groups: group A (DMSO) and group B (MSM). The group A animals (n=5) were treated with 60 mL of topical 90% DMSO aqueous solution, while Group B animals (n=5) received 60 mL of topical 90% MSM aqueous solution on the bowed tendon at days 0, 7, 14, 21, 28, 35, and day 42. Clinical examinations were performed to evaluate the severity of pain and lameness grade. Ultrasound scans of the superficial digital flexor tendon were taken at days 0, 21, and day 42. Images were placed in numerical form, and the fiber alignment score of the fibers (FS) and the echogenicity score (ES) of the superficial digital flexor tendon at the maximum injury zone (MIZ) were recorded. Results showed that pain reduction and lameness significantly (P<0.05) reduced from 21d to 42d in the DMSO animals compared with the MSM animals. The echogenicity score didn’t differ between the two groups at 0d, 21d, and 42d (P>0.05) however, it was significantly declined in group A at 42d than 0d (P<0.05). Fiber alignment in group A was (P<0.01) reduced at 42d compared with group B. This study concluded that group A horses showed very effective and long-term improvements compared to the group B horses.

Intralesional bone marrow and superior check desmotomy is superior to conservative treatment of equine superficial digital flexor tendonitis.

Superficial digital flexor tendon (SDFT) injury is common in racehorses and a significant cause of lost training days and wastage in the industry. To compare the post-injury performance of Thoroughbred and Standardbred racehorses diagnosed with SDFT tendonitis treated with intralesional bone marrow and superior check desmotomy or managed conservatively and further to compare this performance with that of uninjured racehorses. Retrospective and case-controlled. Medical and race records of racehorses treated surgically or managed conservatively for SDFT tendonitis were collated. Signalment, lesion severity and treatment were identified and performance post-injury compared. Performance of the treatment groups was further assessed by comparison with uninjured racehorses matched for age, sex, number of starts pre-injury and randomly selected from the cases' last races. The study population comprised 114 racehorses divided into surgical (39/114), conservative (38/114) and control groups (37/114). Horses that had surgery were more likely to return to racing than those managed conservatively (OR 4.7 95% CI [1.6-14.3], P=.006). Standardbreds were more likely to return to race compared with Thoroughbreds (OR 4.0 95% CI [1.2-13.3], P=.03). There was no statistically significant difference in the average number of placings, average number of wins and post-injury earnings between the surgically treated and conservatively managed groups (P=.9, P=.9 and P=.7, respectively). The average number of lifetime starts post-injury/post-selection between surgery, conservative and control groups were not statistically significantly different (P=.2). Surgically treated horses had a statistically significantly shorter time to start post-injury compared with the conservative group (P=.04). The retrospective nature of the study precludes an actual fit as a nonrandomised clinical trial and the nonrandomised nature of the allocation of the treatment groups is biased. Surgical intervention of superficial digital flexor tendonitis in racehorses suffering flexor tendon injury showed a higher likelihood of return to racing than conservative treatment.

Relationship between the ultrasonographic findings of suspected superficial digital flexor tendon injury and the prevalence of subsequent severe superficial digital flexor tendon injuries in Thoroughbred horses: a retrospective study.

The onset of severe injury to the superficial digital flexor tendon (SDFT) is extremely difficult to predict from slight changes in ultrasonographic findings in cases with no apparent clinical signs. This study investigated the relationship between an increased cross-sectional area (CSA) or edema in the subcutaneous tissue around the tendon and the subsequent onset of severe SDFT injury in Thoroughbred racehorses. Horses were classified into three groups based on ultrasound diagnosis (USD) findings: Group A included cases with enlarged tendons; Group B included cases with tendons of normal size but with prominent edema in the peritendinous tissue; and Group C (control group) included cases with no abnormal USD findings. The incidence of subsequent severe tendon injury was significantly higher in the horses in Groups A (25.7%, 28/101) and B (28.3%, 65/212) than in those in Group C (4.9%, 2/41). There were no significant differences in the median period and the median number of races from the first examination to the subsequent tendon injury between Groups A (140 days, 1 race) and B (120 days, 1 race). The results of this study revealed that horses with increased CSA and peritendinous edema are likely to suffer a subsequent severe tendon injury. Also, these two USD findings, i.e., increased CSA and peritendinous edema, indicate the risk of onset of severe SDFT injury.

Deep Digital Flexor Tendon Injury at the Level of the Proximal Phalanx in Frontlimbs With Tendon Sheath Distension Characterized by Standing Low-Field Magnetic Resonance Imaging in Horses: 13 Cases (2015-2021).

Objective: To describe the MRI findings for 13 horses with deep digital flexor tendon (DDFT) injury at the proximal phalanx where the tendon goes from ovoid to bilobed in frontlimbs with tendon sheath distension. In addition, the prognosis of this lesion was assessed.Design: Retrospective case series.Animals: Thirteen client-owned horses.Procedures: Medical records were reviewed, and data were collected regarding signalment, history, MRI findings, and outcomes of horses. Findings of MRI were recorded and whether the case was confirmed with tenoscopy.Results: A diagnosis of DDFT injury at the junction between ovoid and bilobed portions at the level of the proximal phalanx was established in 13/20 (65%) horses that underwent MRI examination of the frontlimb digital flexor tendon sheath. Return to previous level of work was poor in this subset of horses with only three of 13 (23%) horses returning to previous level of work and one horse still in rehabilitation.Conclusions and Clinical Relevance: Standing low-field MRI represents a potentially useful diagnostic tool to evaluate digital flexor tendon sheath distension especially when evaluating the DDFT at the proximal phalanx where the tendon progresses from ovoid to bilobed. Prognosis of lesions of the DDFT at the proximal phalanx appears less favorable than previously reported causes of tendon sheath distension.

Using Short Term of High Power Laser Therapy in Horse's Tendon Injuries.

High-power laser therapy has been used as a treatment to cure sports injuries; however, there are no controlled standardized studies on its efficacy. Moreover, high-power laser therapy has been applied for the sport horses field. This study aimed to investigate whether high-power laser therapy can cure tendon disorders and reduce the pain in tendon lesions in injured horses and also to examine the effect of laser therapy on injured horses. This retroactive experiential clinical research was performed on50 racing horses between 5 and 15 years old. They were diagnosed with neither superficial digital flexor tendon nor deep digital flexor tendon injuries of the suspensory ligament on either hind or front limbs and were medicated with a high-power laser. The high-power laser was used with a maximum output power of 15000 MW and therapeutic effects were assessed using lameness graded and ultrasound the day after laser therapy (week 2) and 4weeks later (week 6). Results showed that laser treatment was effective and uncomplicated in all injured horses. In addition, significant improvement was observed in ultrasound scores and lameness following high-power laser treatment. There was a progressive correlation between the improvement of lameness and the following parameters; returning tendon survival, normality of tendon tissue and functions in rest, trot, or competition after treatment. According to the results, laser treatment is a good way to eliminate the complications caused by tendon damage.

Longitudinal tendon healing assessed with multi-modality advanced imaging and tissue analysis.

The range of diagnostic modalities available to evaluate superficial digital flexor tendon (SDFT) injury includes magnetic resonance imaging (MRI), computed tomography (CT) and ultrasonography (US). Direct, comprehensive comparison of multi-modality imaging characteristics to end-point data has not previously been performed using a model of tendinopathy but is required to obtain a better understanding of each modality's diagnostic capabilities. To compare CT, MRI and US evaluation to outcome measures for histologic, biochemical and biomechanical parameters using an equine surgical model of tendinopathy. Controlled experiment. Lesions were surgically created in both forelimb SDFTs of eight horses and imaged using MRI, CT and US at seven time points over 12months. Imaging characteristics were then correlated to end point histologic, biochemical and biomechanical data using lasso regression. Longitudinal lesion size was compared between imaging modalities. Lesion to tendon isoattenuation on CT evaluation correlated with the greatest levels of aggrecan deposition. A significant correlation between cellular density and percentage of tendon involvement on the T2-weighted sequence and signal intensity on the proton density fat saturated (PD FS) sequence was appreciated at the 12-month time point (P=.006, P=.02 respectively). There was no significant correlation between end-point data and US or contrast imaging characteristics. Cross sectional area lesion to tendon measurements were significantly largest on CT evaluation, followed by MRI and then US (P<.001). Experimentally induced tendon injury with singular end-point data correlation. Lesion isoattenuation on CT evaluation suggested scar tissue deposition, while T2-weighted hyperintensity indicated hypercellular tendinopathy even in chronic stages of healing. Non contrast-enhanced MRI and CT evaluation correlated most closely to cellular characteristics of surgically damaged tendons assessed over a twelve month study period. Ultrasonographic evaluation underestimates true lesional size and should be interpreted with caution.

Imaging findings and clinical outcome of foot pain attributable to insertional deep digital flexor tendon injury and/or fluid signal within the flexor surface of the distal phalanx

SummaryBackgroundInsertional deep digital flexor tendon (DDFT) lesions with concurrent injury to the flexor surface of the distal phalanx are uncommon and there is limited information regarding prognosis.ObjectivesTo provide descriptive data on horses with insertional DDFT injuries and determine whether there is any association between magnetic resonance imaging (MRI) findings, and outcome.Study designRetrospective case series.MethodsHorses with lameness localised to the foot that underwent low field standing MRI between January 2015 and April 2019 were included. Injury of the DDFT, presence of short tau inversion recovery (STIR) hyperintensity at the flexor surface of the distal phalanx and concurrent lesions were recorded. Follow‐up information was obtained by telephone questionnaire.ResultsThirty‐two horses fulfilled the inclusion criteria. Thirty‐one limbs had DDFT insertional lesions on MRI with three limbs showing hyperintense STIR signal of the flexor surface of the distal phalanx without a tendon lesion. Seventeen DDFT lesions were graded as mild and 14 as severe. Thirteen limbs showed hyperintense STIR signal within the tendon and 15 limbs showed hyperintense STIR signal within the flexor surface of the distal phalanx at the insertion of the DDFT and/or the distal sesamoidean impar ligament (DSIL). Eight horses returned to previous athletic function, 8 returned to a lower level of athletic activity, 4 were retired, 9 were subjected to euthanasia and 3 were lost to follow‐up. No significant association was found between DDFT lesion severity, hyperintense STIR signal within the DDFT, hyperintense STIR signal at the flexor surface of the distal phalanx and outcome post‐injury.Main limitationsSmall sample size and reliance on clients to provide accurate follow‐up information.ConclusionsInsertional DDF tendinopathy carries a guarded prognosis for return to previous athletic function. The presence of hyperintense STIR signal at the flexor surface of the distal phalanx did not appear to influence the prognosis.

Zonal characterization and differential trilineage potentials of equine intrasynovial deep digital flexor tendon-derived cells

BackgroundIntrasynovial deep digital flexor tendon (DDFT) injuries occur frequently and are often implicated in cases of navicular disease with poor outcomes and reinjuries. Cell-based approaches to tendon healing are gaining traction in veterinary medicine and ultimately may contribute to improved DDFT healing in horses. However, a better understanding of the innate cellular characteristics of equine DDFT is necessary for developing improved therapeutic strategies. Additionally, fibrocartilaginous, intrasynovial tendons like the DDFT are common sites of injury and share a poor prognosis across species, offering translational applications of this research. The objective of this study is to isolate and characterize tendon-derived cells (TDC) from intrasynovial DDFT harvested from within the equine forelimb podotrochlear bursa. TDC from the fibrocartilaginous and tendinous zones are separately isolated and assessed. Flow cytometry is performed for mesenchymal stem cell (MSC) surface markers (CD 29, CD 44, CD 90). Basal tenogenic, osteogenic and chondrogenic markers are assessed via quantitative real time-PCR, and standard trilineage differentiation is performed with third passage TDC from the fibrocartilaginous (fTDC) and tendinous (tTDC) zones of DDFT.ResultsLow-density plating isolated homogenous TDC populations from both zones. During monolayer passage, both TDC subpopulations exhibited clonogenicity, high in vitro proliferation rate, and fibroblast-like morphology. fTDC and tTDC were positive for MSC surface markers CD90 and CD29 and negative for CD44. There were no significant differences in basal tenogenic, osteogenic or chondrogenic marker expression between zones. While fTDC were largely restricted to chondrogenic differentiation, tTDC underwent osteogenic and chondrogenic differentiation. Both TDC subpopulations displayed weak adipogenic differentiation potentials.ConclusionsTDC at the level of the podotrochlear bursa, that potentially could be targeted for enhancing DDFT injury healing in horses were identified and characterized. Pending further investigation, promoting chondrogenic properties in cells administered exogenously into the intrasynovial space may be beneficial for intrasynovial tendon regeneration.

Chronic Collateral Sesamoidean Desmopathy in Draft Horses: Magnetic Resonance Imaging and Histopathological Findings

Desmopathy of the collateral sesamoidean ligament (CSL) is an unusual disorder in draft horses. This study records the magnetic resonance imaging (MRI) features of chronic CSL desmopathy in eight draft horses and confirms these features by histopathology. The recorded chronic CSL desmopathy has usually affected the forelimbs (100%) and commonly bilateral (62.5%). All horses showed positive proximal digital nerve block, positive front digital flexion test, and negative interphalangeal extension test. Radiography revealed no osseous abnormalities in all feet. MRI features of chronic CSL desmopathy included thickening of the ligament with increased moderate intensity in fast low-angle shot, T1 turbo spin echo, and proton density images in the affected part of the ligament. Chronic CSL desmopathy was concomitant with deep digital flexor tendon injury and distal sesamoidean impar desmitis. In most chronic cases of CSL desmopathy, heterogeneous signal intensities were seen with multiple foci of low signal intensities interlaced with increased moderate signal intensities of thickened CSL. Histopathology confirmed the MRI findings and revealed separated bundles and fascicles by septa of less organized and loose connective tissues containing fibroblasts and loose collagen fibers. Multifocal islands of cartilaginous metaplasia, mineralized areas, and dystrophic calcification were observed in the injured ligament. In conclusion, chronic CSL desmopathy may progress to cartilaginous metaplasia and dystrophic calcification. MRI is a beneficial diagnostic and prognostic tool for chronic CSL desmopathy, and histopathology is a gold standard to document the MRI findings associated with CSL dysmopathy in draft horses.

Using time-series analysis techniques to enhance the understanding of musculoskeletal injury in Thoroughbred racehorses.

Many racing jurisdictions monitor race-day musculoskeletal injury (MSI) but fail to evaluate injuries occurring during training. Additionally, previous risk factor analyses have failed to explore temporal trends in injury occurrence. To use time-series analysis techniques to identify trends, cyclicity and peaks in MSI incidence, in racehorses training and racing at the Hong Kong Jockey Club (HKJC) from July 2010 to June 2018. Retrospective longitudinal study. The monthly incidence of all MSI, superficial digital flexor tendon (SDFT) injury, suspensory ligament injury and appendicular skeletal fracture occurring in training and racing were collected from veterinary records. The number of horses in training was collated monthly from trainer records. Time-series analysis techniques were used to describe trends and cyclical patterns for injury types. For each injury, incidence risks above the 90th percentile were identified as peaks in incidence. A total of 1471 injuries were recorded over eight racing seasons; 605 fractures (41.1%), 550 SDFT injuries (37.4%), and 316 suspensory ligament injuries (21.5%). Evidence of seasonality was detected in fracture incidence risk; increasing from October (median 0.25 per 1000 horses) until May (median 0.71 per 1000 horses), coinciding with the racing season (ending mid-July). Elevated incidence of MSI occurred throughout 2012; however, the greatest incidence risks of SDFT (14.8 per 1000 horses) and fracture (1.3 per 1000 horses) occurred since 2017. Monthly (opposed to daily) incidence risk of injury reduced the resolution of the data. Additionally, fracture was not described according to bone or fracture type, which may have confounded overall trends. Evidence for seasonal variation in the incidence of fracture occurrence has been demonstrated. Based on using time-series techniques, further epidemiological studies, retrospectively targeting periods of high peaks in injury incidence risk could be used to aid identification of risk factors for injury.

Application of gene therapy in the treatment of superficial digital flexor tendon injury in horses.

Background:Tendon injuries are one of the most common causes of orthopedic disorders in horses. Such injuries involve a long course of treatment and recovery. The most promising method of treating these injuries is the use of recombinant proteins and gene therapy.Aim:In this work, we evaluated the therapeutic efficacy of plasmid DNA (pDNA) containing two species-specific coding sequences, i.e. vascular endothelial growth factor 164 (VEGF164) and fibroblast growth factor 2 (FGF2), in the treatment of severe damage to the tendon of the superficial digital flexor.Methods:A pDNA construct was used to restore the damaged superficial digital flexor tendon in the horse.Results:This study showed that the administration of pDNA encoding VEGF164 and FGF2 genes at the injury area increased the regenerative activities of the damaged tendon.Conclusion:This study shows the therapeutic properties of genetic constructs (pDNA) and contributes to the advancements in the use of these therapies.

The Use of the Water Treadmill for the Rehabilitation of Musculoskeletal Injuries in the Sport Horse.

In recent years, exercise on a water treadmill has come to have great relevance in rehabilitation and training centres for sport horses. Its use exploits certain physical properties of water, related to the fundamental principles of hydrodynamics, such as buoyancy, viscosity, hydrostatic pressure, and water temperature. These properties together with deliberate specification of the depth of the water and the velocity of the treadmill provide a combination of parameters that can be varied according to the purpose of the rehabilitation or training programme, the disease to rehabilitate, or the healing phase. In the current article, kinematic adaptations to exercise on a water treadmill and the direct application of such exercise to the rehabilitation of superficial and deep digital flexor tendon and accessory ligament injuries and back and joint diseases are described.

Autologous platelet rich plasma for regeneration of tendon injuries in horses

Digital flexor tendon injuries are the most common cause of early retirement and economic loss in the equine industry due to the poor healing tendency of the tendons. This study was conducted to improve the quality of tendon healing by using Autologous Platelet Rich Plasma incorporated collagen scaffold. Using ultrasound guidance, autologous Platelet Rich Plasma with and without collagen scaffold was engrafted intra-lesionally into 12 affected digital flexor tendons of 11 horses and healing was assessed periodically. Lameness score decreased in all the horses and the therapeutic outcome of intra-lesional engraftment of Autologous Platelet Rich Plasma with collagen scaffold was found to be superior in terms of clinical outcome, ultrasonographic and biochemical assessment. Ultrasonography served as an effective tool for diagnosis and for evaluation of healing tendon injuries.