Superficial Digital Flexor Tendonitis Research Articles

Comparative Regenerative Effects of Allogeneic Bone Marrow and Patellar Ligament Fat Pad Mesenchymal Stem Cells on Experimental Superficial Digital Flexor Tendonitis in New Zealand Rabbits

Background: Cell therapy is applied in tendonitis to speed the healing process of tendon tissue and restore its functional properties. Almost all types of stem cells can differentiate from the recipient cells after transplantation. Objectives: The main goal of this study is to compare the effects of two sources of mesenchymal stem cells on tendon regeneration. Methods: This study randomly divided 32 New Zealand rabbits into 4 groups. The bacterial collagenase was induced at the superficial digital flexor tendon (SDFT) of all rabbits, and the treatment was performed 48 hours after collagenase induction. Group 1 was treated with allogeneic bone marrow mesenchymal stem cells (BMMSCs). Group 2 was treated with adipose-derived stem cells (ADSCs) from the patellar ligament fat pad. Group 3 (sham group) was treated with 0.9% normal saline, and group 4 (control group) was left with no treatment. All rabbits were euthanized 2 and 4 weeks after surgery, and tendon samples were harvested. The histopathology was assessed by hematoxylin-eosin, Masson’s trichrome, and Vangieson’s dye, and tendon structure, fiber arrangement, cell nuclei, tissue inflammation, vascularity (angiogenesis), and density were surveyed. Results: The tendon healing process in the BMMSC and ADSC groups revealed better regeneration than the control and sham groups (P≤0.05). Significant changes (P≤0.05) in some microscopic parameters were seen by comparing the BMMSC and ADSC groups. Conclusion: According to the present study, the injection of mesenchymal stem cells (BMMSCs or ADSCs) showed beneficial results in tendon tissue healing. Furthermore, ADSCs showed better regeneration of the injured tendon tissue than BMMSCs.

Electrohydraulic Shockwave for Treatment of Forelimb Superficial Digital Flexor Tendinitis and Proximal Suspensory Desmitis in Horses

Superficial digital flexor tendinitis (SDFT) and proximal suspensory desmitis (PSD) are common causes of lameness in horses. Current treatment options include rest, controlled exercise, administration of anti-inflammatories, intralesional injections, surgery, and electrohydraulic shock wave therapy (ESWT). ESWT is safe, noninvasive, and is used to treat a variety of musculoskeletal abnormalities. Medical records between 2010 and 2021 were reviewed. Horses were separated into two categories: (group 1: ≥ 3 ESWT treatments; group 2: < 3 ESWT treatments). Our objective was to examine the effect of the number of ESWT treatments in the management of SDFT and PSD injuries and to compare short- and long-term outcomes for the two groups. For group 1, lameness scores between the first and third treatments were significantly reduced in both PSD (p<0.0001) and SDFT (p=0.016) horses. However, neither the PSD (p=0.062) nor SDFT's (p=0.125) ultrasound findings were significantly different at the end of the third treatment.Horses with PSD showed a significant improvement in forelimb lameness between the first and third treatments compared to hindlimb (p = 0.033). In the multivariable ordered logistic regression model, only time (months of follow-up) was significantly associated with a positive outcome (p=0.001) and there was no difference in short and long-term outcome between groups 1 and 2. Also, chronicity of injury was negatively associated with improvement of lameness (p=0.028).

Treatment of racehorse superficial digital flexor tendonitis: A comparison of stem cell treatments to controlled exercise rehabilitation in 213 cases.

Overstrain of the superficial digital flexor tendon (SDFT) is a common Thoroughbred racehorse limb injury requiring treatment. To determine whether treatment of SDFT lesions in flat Thoroughbred racehorses with autologous bone marrow-derived mesenchymal stem cells (BM-MSCs) or allogenic adipose-derived mesenchymal stem cells (A-MSCs) is associated with improved likelihood of returning to racing, when compared to racehorses managed with a controlled exercise rehabilitation program (CERP) alone. Retrospective cohort study combining clinical treatment records with race records. A total of 213 Thoroughbred racehorses were identified. All were prescribed the same 12-month CERP and 66 also received intralesional BM-MSC and 17 A-MSC treatment. Follow-up was a minimum of 2 years after return to full race training. Multivariable logistic regression models were used to investigate associations between the treatments and the likelihood of returning to racing and completing five or more (C5+) races post-injury. Compared to CERP alone, BM-MSC treatment was associated with increased odds of returning to racing (OR 3.19; 95% CI 1.55-6.81) and C5+ races post-injury (OR 2.64; 95% CI 1.32-5.33). Older age and increasing lesion length were associated with a reduced likelihood of returning to racing. Male sex and increased number of pre-injury starts were associated with increased odds of returning to racing. There was no observed increased likelihood of return to racing or C5+ races associated with treatment with A-MSCs compared to CERP alone. Due to the retrospective nature of the study it was not possible to ascertain how strictly the CERP was followed. Due to the novelty of the method, the A-MSC treatment group included a limited number of horses. In the study population, intralesional BM-MSC treatment was significantly associated with an increased likelihood of returning to racing and C5+ races post-injury compared to CERP alone. Intralesional A-MSC showed no significant association between treatment and the two investigated outcomes.

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.

Electrohydraulic Shockwave for Treatment of Forelimb Superficial Digital Flexor Tendinitis and Proximal Suspensory Desmitis in Horses

Electrohydraulic Shockwave for Treatment of Forelimb Superficial Digital Flexor Tendinitis and Proximal Suspensory Desmitis in Horses

Evaluation of Autologous Protein Solution Injection for Treatment of Superficial Digital Flexor Tendonitis in an Equine Model.

Autologous protein solution (APS) has been used anecdotally for intralesional treatment of tendon and ligament injuries, however, its use in these injuries has never been studied in vivo. Our objective was to evaluate the effect of APS on tendon healing in an equine superficial digital flexor (SDF) tendonitis model. We hypothesized intralesional injection of APS would result in superior structural and biomechanical healing. SDF tendonitis was induced in both forelimbs of eight horses using collagenase injection. One forelimb was randomly assigned to receive an intralesional injection of APS, while the other was injected with saline. Ultrasonographic examinations were performed at weeks −1, 0, 2, 4, 8, and 12 following treatment. At 12 weeks, horses were euthanized and SDF samples harvested. Histologic evaluation, biomechanical testing, gene expression analysis, total glycosaminoglycan (GAG) and total DNA quantification were performed. Collagen type III (COL3A1) expression was significantly higher (p = 0.028) in saline treated tendon than in normal tendon. Otherwise, there were no significant differences in gene expression. There were no significant differences in histologic or ultrasonographic scores between groups. Mean total DNA content was significantly higher (p = 0.024) in saline treated tendons than normal tendons, whereas total DNA content was not significantly different between APS treated tendon and normal tendon. Elastic modulus was higher in APS treated than saline treated tendon, but the difference was not significant. Reduced expression of COL3A1 in APS treated tendon may indicate superior healing. Increased total DNA content in saline treated tendon may indicate ongoing healing processes, vs. APS treated tendons which may be in the later stages of healing. Limitations include a relatively short study period and inconsistency in size and severity of induced lesions. Intralesional injection of APS resulted in some improvements in healing characteristics.

Appraising the Welfare of Thoroughbred Racehorses in Training in Queensland, Australia: The Incidence and Type of Musculoskeletal Injuries Vary between Two-Year-Old and Older Thoroughbred Racehorses

Simple SummaryMusculoskeletal injuries (MSI) remain a concerning cause of racehorse morbidity and mortality with serious ethical and welfare consequences. Previous research examining risk factors for injuries report inconsistent findings. Age is thought to affect the risk of injury, but, to date, there have been no prospective studies specifically comparing injuries between two-year-old versus older horses. We aimed to: (1) determine the incidence of injuries for two-year-old and older horses, and whether this was affected by training track, season, or rainfall, and (2) determine the types of injuries affecting two-year-old and older horses, and whether horses trialled or raced after injury. Data were collected through personal structured weekly interviews with participating trainers over a 13-month period. Data were analysed using Poisson regression. The incidence of MSI in the current study was low (0.6%). The incidence of MSI in two-year-old horses was higher than older horses. Types of MSI varied between two-year-old and older horses and affected whether horses subsequently trialled or raced from 11 to 23 months after injury. A larger proportion of two-year-old horses had dorsal metacarpal disease and traumatic lacerations. A smaller proportion of two-year-old horses had suspensory desmitis, superficial digital flexor tendonitis, proximal sesamoid bone fractures, and fetlock joint injuries than older horses. Training track and rainfall did not affect the incidence of injuries. The season affected the incidence of injuries in two-year-old horses but not in older horses.Musculoskeletal injuries (MSI) remain a concerning cause of racehorse morbidity and mortality with important ethical and welfare consequences. Previous research examining risk factors for MSI report inconsistent findings. Age is thought to affect MSI risk, but, to date, there have been no prospective studies comparing MSI in two-year-old versus older horses. This study aimed to: (1) determine the incidence of MSI for two-year-old and older horses, and whether this was affected by training track, season, or rainfall, and (2) determine the types of MSI affecting two-year-old and older horses, and whether horses trialled or raced after injury. A prospective survey was conducted with data collected through personal structured weekly interviews with participating trainers over a 13-month period. Data were analysed using Poisson regression. The incidence of MSI in the current study was low (0.6%). The incidence of MSI in two-year-old horses was higher than older horses (p < 0.001). Types of MSI varied between two-year-old and older horses (p < 0.001) and affected whether horses subsequently trailed or raced from 11 to 23 months after injury (p < 0.001). A larger proportion of two-year-old horses had dorsal metacarpal disease and traumatic lacerations. A smaller proportion of two-year-old horses had suspensory ligament desmitis, superficial digital flexor tendonitis, proximal sesamoid bone fractures, and fetlock joint injuries than older horses. Training track and rainfall did not affect MSI. The season affected MSI in two-year-old horses (p < 0.001) but not older horses. The major limitation was that trainers in this study were metropolitan (city) and our findings may not be generalisable to racehorses in regional (country) areas. Another significant limitation was the assumption that MSI was the reason for failure to trial or race after injury. In conclusion, the incidence of MSI was low in the current study and the types and the risk factors for MSI are different for two-year-old and older horses.

Superficial digital flexor tendinitis treatment using high-intensity laser therapy and therapeutic ultrasound in polo ponies

High-intensity laser therapy (HILT) is an alternative technique that should provide better results than therapeutic ultrasound in the treatment of tendinitis. However, there has not yet been a study to support this hypothesis in horses, especially in polo ponies. This study aims to follow up the outcomes of high-intensity laser therapy and therapeutic ultrasound in tendinitis polo ponies in Thailand. Twelve limbs with tendinitis from 10 ponies were included in the study after lameness examination; the limbs were confirmed to have tendinitis via ultrasonography. The ponies were randomized to high-intensity laser therapy and therapeutic ultrasound group. Recordings of the severity of the cross-sectional area (CSA), echogenicity score, fiber alignment score (FAS), lameness examination and pain responsive were performed on day 0, day 8, day 30 and day 60. The samples were randomized to six limbs in each treatment group. The results show that there was no significantly change in the CSA within treatment groups (HILT: p = 0.2; therapeutic ultrasound p &gt; 0.9) and between the treatment group (p &gt; 0.9), echogenicity score or FAS within and between the treatment group in 60 days of study. None of the ponies in this study experienced skin reactions from the treatment. In conclusion, both high-intensity laser therapy and therapeutic ultrasound are safe to use in the tendinitis of polo ponies and have the ability to decrease inflammation. However, a rehabilitation program is still the most important part that should be controlled along with the treatment.

Autologous mesenchymal stem cells for treatment of acute superficial digital flexor tendonitis in athletic horses:&#x0D;clinical study of 15 cases

Autologous mesenchymal stem cells for treatment of acute superficial digital flexor tendonitis in athletic horses:&#x0D;clinical study of 15 cases

Comparing Rest Alone to Bandaging and Rest in Horses With Superficial Digital Flexor Tendinopathy

&lt;strong&gt;PICO question&lt;/strong&gt;&lt;br /&gt;&lt;p&gt;In horses with superficial digital flexor tendonitis is bandaging and rest compared to rest alone more effective at promoting healing?&lt;/p&gt;&lt;strong&gt;Clinical bottom line&lt;/strong&gt;&lt;br /&gt;&lt;p&gt;There is currently a lack of scientific evidence to suggest that bandaging promotes effective tendon healing following injury. However, rigid bandages significantly limit lesion propagation in equine superficial digital flexor (SDF) tendinopathies. The result of this PICO question suggests that a short period (ten days) of cast immobilisation during the initial inflammatory phase of the injury improves prognosis by limiting lesion propagation. The level of confidence in the outcomes from the body of evidence in the four studies identified is moderate.&lt;/p&gt;&lt;br /&gt; &lt;img src="https://www.veterinaryevidence.org/rcvskmod/icons/oa-icon.jpg" alt="Open Access" /&gt; &lt;img src="https://www.veterinaryevidence.org/rcvskmod/icons/pr-icon.jpg" alt="Peer Reviewed" /&gt;

Clinical findings and prognosis of interference injuries to the palmar aspect of the forelimbs in Standardbred racehorses: A study on 74 cases.

Information on interference injuries in racehorses is lacking. To describe clinical findings and prognosis of palmar forelimb interference injuries in Standardbreds. Retrospective cohort study. Records of 74 racehorses sustaining palmar forelimb interference injuries were studied; 7 occurred during training and 67 during racing. The number of starts before injury, hind shoeing status, gait penalties and racing speeds in cases occurring during racing were compared with negative controls (67 age, sex and speed category matched horses) from the same races. The number of starts and racing speed in 30 racing days preceding recruitment were compared with those following recruitment (negative controls) or return to racing (cases). Clinical aspects and outcome in interference-induced superficial digital flexor (SDF) tendonitis were compared with 77 horses with overstrain-induced SDF tendonitis. In 89% of cases, there was SDF tendonitis and this was associated with a longer time to return to racing (6 months vs. 1 months; P<0.001). The presence of gait penalties (odds ratio (OR) 11.13; 95% CI 3.74, 41.64; P<0.001) and unshod hind feet (OR = 6.26, 95% CI 2.26, 19.62; P<0.001) increased risk of interference injuries. After recruitment/return to racing, horses with interference injuries participated in a lower number of races (24 starts per racing day, interquartile range [IQR] 20-32) compared with controls (49, IQR 43-55, P<0.0001). Interference-induced tendonitis cases (n = 58) had a shorter time to return to racing (245 ± 137 days) than overstrain-induced tendonitis cases (331 ± 118 days, P<0.001). Data were collected retrospectively; time of ultrasonographic assessment varied and health status of the racing controls is unknown. SDF tendonitis is common with palmar forelimb interference injuries in Standardbreds and increases time to return to racing. Interference-induced SDF tendonitis has a better prognosis than overstrain-induced tendonitis.

Randomized controlled trial demonstrates the benefit of RGTA® based matrix therapy to treat tendinopathies in racing horses.

A randomized controlled trial was performed on racing horses, to evaluate the efficacy of a new class of therapeutic agents in regenerative medicine—ReGeneraTing Agents® (RGTA®), to treat tendinopathies. Preliminary uncontrolled studies on tendon healing in racing horses with RGTA® (OTR4131)—Equitend® showed encouraging results, justifying performing a randomized, controlled, multicenter study with a two-year racing performance follow up. The objective of this study was to evaluate the effect of Equitend® versus placebo on acute superficial digital flexor tendonitis in racing French Standardbred Trotters (ST). Twenty-two ST were randomly and blindly assigned to receive with a ratio of 2 to 1, a single Equitend® (n = 14) or placebo (n = 8) intralesional injection under ultrasonographic guidance. Horses were evaluated over 4 months, by clinical and ultrasonographic evaluations (day 0, months 1, 2, 4), and their racing performances followed up over the 2 years after treatment. During the first month of treatment, a significant decrease in the cross-sectional area (CSA) was found in the Equitend® group (p = 0.04). After 4 months, the number of Equitend® treated horses with an improved CSA was significantly higher than the placebo-treated horses (p = 0.03571). The Equitend® group returned to their pre-injury performance level, racing in, and winning, significantly more races than the placebo group (p = 0.01399 and 0.0421, respectively). Furthermore, recurrence was significantly higher in the placebo group than in the Equitend® group (71.4% vs 16.6%, p = 0.02442). In conclusion, we measured a significant, short-term, reduction effect on CSA and demonstrated a long-term beneficial effect of intralesional injection of Equitend® for the treatment of superficial digital flexor tendonitis on racing ST, racing 2. 3 times more often than placebo, with 3.3 times fewer recurrences maintaining pre-injury performance level. This study may open the way for the development of a human treatment of tendonitis.

Clinical application of adipose-derived stromal vascular fraction in 3 Thoroughbred horses with superficial digital flexor tendonitis: Case Report

Tendon injuries are considered major causes of wastage in active Thoroughbred racehorses as they are among the most common musculoskeletal injuries in equine athletes. There has been considerable interest in the potential use of concentrated adipose tissue digest, such as stromal vascular fraction, in tendon overstrain injuries. It has been reported that the adipose-derived stem cells, which are present in stromal vascular fraction of adipose tissue, can promote neovascularization and improve healing process. The purpose of this study was to evaluate the potential effects of intralesional use of autologous adipose-derived stromal vascular fraction on tendon healing in three Thoroughbred active racehorses with moderate to severe superficial digital flexor tendonitis. Based on the results of this report it seems that intratendinous injection of autologous adipose-derived stromal vascular fraction leads to marked clinical improvement and reduction of rehabilitation period in racehorses suffering from superficial digital flexor tendonitis.

A retrospective study of radiographic abnormalities in the repositories for Thoroughbreds at yearling sales in Japan

This study aimed to evaluate whether radiographic abnormalities at yearling sales were associated with the failure to start racing at 2–3 years of age. Radiographic abnormalities in the carpal (n=852), tarsal (n=976), metacarpophalangeal (n=1,055), and metatarsophalangeal joints (n=1,031) from 1,082 horses, recorded at yearling sale, were reviewed. Eighty-two horses (7.6%) failed to start racing. Radiographic abnormalities such as wedged or collapsed tarsal bones, irregular lucency of a sagittal ridge at the distal aspect of the distal third metatarsal bone, and proximal dorsal fragmentation of the first phalanx in metatarsophalangeal joints were associated with failure to start racing in these horses. In the follow-up survey of 12 horses with one or more these radiographic abnormalities, the horses failed to start racing due to reasons unrelated to these radiographic abnormalities such as pelvic fractures (2 horses), fracture of a distal phalanx (1 horse), cervical stenotic myelopathy and proximal sesamoid fracture (1 horse), superficial digital flexor tendonitis (2 horses), laryngeal hemiplegia (1 horse), economic problems (2 horses) and unknown causes (3 horses). Although radiographic abnormalities at yearling sales can be associated with failure to start racing at 2–3 years of age, these radiographically detected abnormalities might not necessarily cause that failure.

Comparison of treatment outcomes for superficial digital flexor tendonitis in National Hunt racehorses

Superficial digital flexor (SDF) tendonitis is a common injury in Thoroughbred racehorses. Injuries require prolonged rehabilitation, with unpredictable outcomes and a high incidence of re-injury. This observational case–control study aimed to compare race outcomes after commonly advocated treatments for tendon healing. Clinical and racing records were evaluated for 127 National Hunt racehorses treated between 2007 and 2011 for an SDF tendon injury. Two age- and sex-matched control horses were selected for each case horse to analyse the effect on post-injury racing outcomes of pre-injury data, lesion severity and treatment group [controlled exercise alone, bar firing, intralesional platelet-rich plasma (PRP), tendon splitting, tendon splitting combined with bar firing]. Control horses raced more often than case horses, with higher maximum racing post rating (RPRmax) and longer racing distances. Pre-injury racing performance was not associated with treatment group. Rate of return to racing was not associated with lesion severity or treatment group. Number of races, total distance raced post-injury and RPRmax were not associated with lesion severity or treatment group. Controlled exercise alone offered similar post-injury racing outcomes in National Hunt racehorses with SDF tendonitis to the other treatment options examined. Bar firing, either alone or in conjunction with tendon splitting, provided no additional benefit in rate of return to racing and race performance.

Autologous bone marrow aspirate for treatment of superficial digital flexor tendonitis in 105 racehorses

To evaluate a treatment protocol whereby superficial digital flexor (SDF) tendonitis in Thoroughbred and Standardbred racehorses was treated with autologous bone marrow aspirate (ABMA) obtained from the sternebrae. This treatment...

Non-fatal injury occurrence in Southern California Thoroughbred racehorses 2009–2010

Private-practice racetrack veterinarians in southern California recorded non-fatal injuries meeting defined criteria in Thoroughbreds for 1 year. Injury incidence was 2.29 injury events per 100 horse-months, which was lower than other studies where trainer reported injury data were collected. Of 477 injuries recorded, 344 (72.1%) were acute and 133 (27.9%) were chronic. Fractures were common (47.6% of injuries), with stress fractures accounting for 14% of injuries. Superficial digital flexor tendonitis and suspensory ligament desmitis accounted for 15.3 and 11.5% of injuries, respectively. Agreement between non-fatal injuries recorded in the current study and those recorded via an existing regulatory system (Equine Injury Database) was poor, with neither system capturing all injuries. Non-fatal injuries occurred 17–29 times more often than fatal injuries. Non-fatal musculoskeletal injury remains an ongoing issue for Thoroughbred racehorses, and an accurate, comprehensive system for recording these injuries is needed.

Long-Term Follow-up of Superficial Digital Flexor Tendonitis Treated by a Single Intralesional Injection of a ReGeneraTing Agent in 51 Horses

ReGeneraTing Agents (RGTA) are nanopolysaccharides engineered to mimic heparan sulfates and have been shown to stimulate tissue repair and healing (skin, cornea, gingival, and muscle) in several animal models of injury and in human medicine. A preliminary study, monocentric and uncontrolled, was conducted to evaluate the efficacy of a dedicated RGTA (named Equitend) in improving the healing quality of the injured tendon after a single and ultrasound-guided intralesional injection. Improvement of ultrasonographic appearance of tendinous or ligamentous lesion was documented at least over 4 months in Equitend-treated horses and was further supported by another study on superficial digital flexor tendonitis, in 51 horses (16 French Standardbred trotters (ST), 13 Thoroughbreds (TB), and 22 eventers). Long-term follow-up of these horses showed high rates of return to racing, with 95% of eventers, 87.5% of French ST, and 77% of TB. The mean duration before the first race or competition was 6.6 and 7.4 months for ST and eventers, respectively. The group of 16 treated ST was then compared with a matched control group, showing that the Equitend-treated group was able to return to a higher level of earning after lesion (74% vs. 15% in the control group). Furthermore, the Equitend-treated group was back in racing 2.4 months earlier than the control group.

Racing performance of Thoroughbreds with superficial digital flexor tendonitis treated with desmotomy of the accessory ligament of the superficial digital flexor tendon: 332 cases (1989-2003).

To assess postoperative probability of racing, career longevity, and convalescent time in Thoroughbred racehorses with moderate to severe superficial digital flexor tendonitis (SDFT) in the forelimbs treated by desmotomy of the accessory ligament of the superficial digital flexor tendon (ie, superior check ligament desmotomy [SCLD]). Retrospective case series. 332 Thoroughbred racehorses with SDFT consecutively treated by means of SCLD. Medical records and racing records were reviewed to assess return to racing, number of races completed, time to first race, and lifetime performance. The horses were categorized as raced or unraced prior to and after surgery. Descriptive statistics including age and treated limb were also recorded. Of 332 horses, 228 (69%) returned to racing following injury and treatment. Seventy-eight of 118 (66%) horses that had not raced prior to injury and 150 of 214 (70%) horses that had raced prior to injury raced after treatment. Seventeen of 39 (44%) horses ≥ 5 years old raced following injury and treatment and 211 of 293 (72%) horses ≤ 4 years old returned to racing. There was no difference in the percentages of horses returning to racing for 2-, 3-, or 4-year olds. Postoperative infections occurred in 6 of the 332 (2%) horses. Median time to first race for horses that raced after surgery was 302 days (range, 48 to 1,120 days; mean ± SD, 341 ± 153 days), with a median of 8 starts/horse after surgery (range, 1 to 109 starts; mean ± SD, 14 ± 15.8 starts). Of 228 horses that returned to racing, 159 (70%) raced ≥ 5 times after surgery. Sex and treated limb did not have a significant effect on return to racing. However, horses ≥ 5 years old were significantly less likely to return to racing, compared with younger horses. In horses with unilateral SDFT and < 5 starts, the affected and contralateral limbs were both treated, but return to racing was not significantly different between horses treated bilaterally versus unilaterally. 228 of 332 (69%) horses with SDFT of the forelimb treated with SCLD successfully returned to racing. Convalescent times were shorter, compared with previous recommendations, and treated horses had a longer racing career after surgery than has been described for other treatment modalities. The results of the present study support consideration of SCLD as part of a treatment plan for SDFT in Thoroughbred racehorses.

Superficial digital flexor tendonitis in cutting horses: 19 cases (2007–2011)

To characterize superficial digital flexor (SDF) tendon lesions in the forelimbs of cutting horses and determine recurrence rate and prognosis for this condition. Retrospective case series. 19 cutting horses with SDF tendonitis. Medical records for horses evaluated for SDF tendonitis in 2007 through 2011 were reviewed. Data regarding age, sex, lameness grade, affected limb, and treatment were collected. Ultrasonographic images were reviewed, and lesion characteristics were recorded. Follow-up telephone interviews with owners or trainers were conducted to determine recurrence of SDF tendonitis, return of horse to its previous level of activity, and duration of the convalescent period. All 19 horses initially evaluated for SDF tendonitis had similar lesions in the lateral aspect of the tendon. The right forelimb was affected in 11 horses, and the left forelimb was affected in 7 horses; 1 horse was affected in both forelimbs. Mean lameness grade was 1.26 (range, 0 to 3). Of 17 horses for which follow-up information was available, 3 had recurrence of tendon lesions and 1 developed a lesion in the contralateral forelimb SDF tendon; 16 horses returned to their previous level of activity. The location of SDF tendonitis in cutting horses appeared to be unique in that no central core lesions were detected ultrasonographically. Lesions at the periphery of the tendon may have an increased ability to heal, compared with lesions at the central core. Results suggested that cutting horses with SDF tendonitis have a better prognosis than that reported for affected racehorses.