Digital Flexor Tendon Sheath Research Articles

Ultrasound Effectiveness of Steroid Injection for hand Psoriatic Dactylitis: Results from a Longitudinal Observational Study.

IntroductionTo assess clinical and ultrasound effectiveness of steroid injection (local treatment, LT) into the digital flexor tendon sheath for the treatment of psoriatic dactylitis compared to systemic treatment (ST) alone.MethodsIn this observational, multicentre, prospective study, 88 cases of symptomatic hand dactylitis were evaluated clinically and sonographically by high-frequency ultrasound (US) probe in both greyscale (GS) and power Doppler (PD). The presence of flexor tenosynovitis (FT), soft tissue oedema (STO), peritendon extensor inflammation and synovitis was assessed (including DACtylitis glObal Sonographic—DACTOS—score) before treatment, at 1-month (T1) and 3-months (T3) follow-up. LT was proposed to all patients. Patients refusing LT were treated with oral NSAIDs. Patients continued the same baseline csDMARDs and/or corticosteroid therapy during the whole follow-up period. US response was defined for DACTOS score < 3 and US remission for DACTOS score = 0.ResultsAt T3 evaluation the ST group showed a significantly higher persistence (grade > 1) of FT and STO (p < 0.001 for all) and MCP synovitis (p = 0.001). US remission was achieved only in the LT group (at T3 31% vs. 0, p < 0.001). The percentage of patients with DACTOS < 3 was significantly greater in the LT group compared with ST group, at both T1 (49% vs. 5%, p < 0.001) and T3 evaluation (76% vs. 7%, p < 0.001). In multiple conditional logistic regression analysis, the only factor associated with US remission was LT (T3 odds ratio = 41.21, p < 0.001).ConclusionsUS confirmed the effectiveness of steroid injection for dactylitis by demonstrating that it involves the resolution of extra-articular inflammation, in particular FT and STO.

Comparison of Synovial Fluid Composition in Distended and Normal Digital Flexor Tendon Sheath of Horses (A Pilot Study)

Diagnosis of tenosynovitis is usually confirmed on the basis of synovial fluid analysis (such as cytological and biochemical examinations). This study was designed to examine biochemical (serum amyloid A (SAA), haptoglobin (Hp) and D-dimer) and cytological (total nucleated cell count (TNCC), neutrophil, lymphocyte, and monocyte count) characteristics of serum and synovial fluid of the equine digital flexor tendon sheath (DFTS). Synovial fluid samples were aseptically collected in EDTA from 43 limbs in 20 horses with (study group) and 8 limbs in 8 horses without (control group) distention of DFTS and serum samples were collected from each horse. Lymphocyte, monocyte, neutrophil, and TNCC in the synovial fluid were statistically higher in the distended sheath that shows an inflammatory nature of the distention, however, concentrations of D-dimer was lower in serum (0.1, 0.10-3.80) and (0.2, 0.10-0.20) than synovial fluid (19.2, 17.78-20.00) and (20, 19.90-20.00)) in both groups. The serum SAA concentrations of the control group (1.7, 0.10-2.16) were significantly higher than the study group (1, 0.86-1.05) and the concentration of SAA in serum was higher than synovial fluid (0.89, 0.86-0.98) in the control group. Results of this current study show that a cytological evaluation of the synovial fluid is more valuable than biochemical findings in the diagnosis of the inflammatory nature of this condition.

Ex vivo evaluation of needle endoscopy in the equine digital flexor tendon sheath

Ex vivo evaluation of needle endoscopy in the equine digital flexor tendon sheath

Risk of septic spread during surgical management of digital flexor tendon sheath phlegmon: Exsanguination by mechanical compression versus simple elevation

This study aimed to demonstrate that there was no risk of extension of infection in performing mechanical exsanguination before inflating the tourniquet for surgical treatment of digital flexor tendon sheath phlegmon. The series comprised 96 patients, with a mean age of 47 years (range, 18–87 years) and 37 women. Group I included 47 patients in whom exsanguination was performed with a Velpeau band before inflating the pneumatic tourniquet at the root of the limb. In Group II, which included 49 patients, the tourniquet was inflated after simple elevation of the limb. Six patients underwent revision surgery for recurrence or osteoarticular complications: 4 (8.5%) in Group I and 2 (4.1%) in Group II, the difference between two groups being non-significant (p = 0.6378). In conclusion, mechanical exsanguination before inflating the tourniquet did not incur risk of complications in surgical management of digital flexor tendon sheath phlegmon.

Comparison of basilar sesamoidean and distal approaches for synoviocentesis of the forelimb digital flexor tendon sheath in horses.

To evaluate synoviocentesis of the equine forelimb digital flexor tendon sheath (DFTS) via a basilar sesamoidean approach (BSA) or distal approach (DA). 21 healthy adult horses without DFTS-related lameness. The forelimbs of each horse underwent the BSA or DA (21 limbs/approach) performed by 1 individual. The volume of synovial fluid (SF) aspirated, time from skin puncture to collection of SF, and number of attempts to place a needle in the DFTS were compared between approaches. An SF sample was successfully aspirated from 16 of 21 (76%) limbs with the BSA and 20 of 21 (95%) limbs with the DA. For the BSA and DA, the number of attempts to obtain SF was 2 and 1, respectively; the median volume of SF obtained was 0.4 and 0.7 mL, respectively; and the median time to SF collection was 17.91 and 18.48 seconds, respectively. Between the approaches, the number of limbs with SF successfully aspirated and number of attempts to collect SF differed significantly, whereas the volume of SF aspirated and time to SF collection did not. Regarding SF collection from forelimb DFTSs in horses without DFTS-related disease, use of the DA had a greater success rate with fewer attempts, compared with findings for the BSA, which may reflect the relative ease of identifying anatomic landmarks for the DA. Results suggested that a DA for DFTS synoviocentesis in horses appears efficient and effective and may minimize limb trauma by requiring fewer attempts for SF sample collection, compared with a BSA.

Diagnosis of digital flexor tendon sheath conditions in the horse

Diagnosis of digital flexor tendon sheath conditions can be challenging, although they are a common occurrence in horses. Injuries can occur in either the fore- or hindlimbs and a thorough understanding of the complex anatomy of the digital flexor tendon sheath will help practitioners to gain confidence in their diagnostic ability of its pathologies. This article outlines the clinically relevant anatomy, approaches to and interpretation of diagnostic anaesthesia, as well as common stable-side imaging findings that may be expected for the main pathologies associated with the digital flexor tendon sheath. Tips and tricks to maximise diagnostic potential are also included throughout the article.

Tenectomy of the superficial digital flexor tendon as a treatment of suspected septic tendinitis and tenosynovitis of the digital flexor tendon sheath followed by rehabilitation with an orthotic device

SummaryA 15‐year‐old Sports horse gelding was referred for nonweightbearing lameness of the left hindlimb. Septic cellulitis was diagnosed and managed medically. After 14 days, septic tenosynovitis of the digital flexor tendon sheath (DFTS), with septic tendinitis of the superficial (SDFT) and deep (DDFT) digital flexor tendons, became evident. Surgical resection of the intrathecal portion of the septic SDFT was performed. Post‐operatively, a half‐limb cast was placed on the operated limb for 10 weeks followed by an articulated orthotic support boot during a rehabilitation period of 6 weeks. The horse recovered and regained long‐term pasture soundness. Ultrasonography demonstrated the presence of bridging connective tissue in the location of the resected SDFT.

Septic Tenosynovitis of the Digital Flexor Tendon Sheath in 83 Cattle.

Simple SummaryLameness is an ongoing challenge for the cattle industry because it affects the wellbeing and productivity of the animals. Lameness is mostly caused by claw disorders; however, infection of the digital flexor tendon sheath (septic tenosynovitis) is a frequent complication of claw lesions and penetrating wounds located at the lower limb in cattle. Our aim was to describe clinical findings, methods of diagnosis, and outcome in cattle diagnosed with this condition. We aimed to illustrate three different surgical techniques and their success, including the improvement of gait (locomotion) and life expectancy of cattle after surgery. We found that most animals that were subjected to surgical treatment could be discharged cured, even though postsurgical complications had occurred in 17 animals. In all cattle, locomotion improved over the course of hospitalization, which lasted between 13 and 21 days in most cases. After treatment, cattle lived for another 23.7 months on average. This allowed the patients to almost reach the life expectancy of an average Austrian dairy cow. Therefore, we conclude that surgical treatment of cows for septic tenosynovitis of the digital flexor tendon can be performed successfully and is an economically viable option to keep cattle in the herd.Septic tenosynovitis of the digital flexor tendon sheath (DFTS) is the second most prevalent infection of deeper structures of the distal limb in cattle, after septic arthritis of the distal interphalangeal (DIP) joint. Depending on the type of infection and the involvement of adjacent anatomical structures, various surgical techniques may be used for therapy: Incising the DFTS to resect one or both digital flexor tendons (RDFT), additional resection of the DIP joint (RDIP) or additional digital amputation (RAMP). Our goal was to describe clinical findings and outcome in cattle patients (euthanasia vs. treatment) and the success of surgical methods including improvement of locomotion and postoperative survival time (POST). Data of eighty-three cattle with a mean age of 4.3 years were reviewed in this retrospective study. Overall, 57.7% of tenosynovitis cases were in the lateral DFTS of a hind limb. Fifty-five cattle were treated surgically; the remaining 28 cattle were euthanized following diagnosis. The median cumulative POST was 17.3, 83.1, and 11.9 months for RDFT, RDIP, and RAMP, respectively. Fatal postoperative complications occurred in three cattle. We conclude that the applied methods were successful and allowed the animals to almost reach the average life expectancy of an Austrian dairy cow.

Is the T-ligament a ligament? A histological study in equine cadaver forelimbs

Foot pain is a frequent cause of lameness in horses and can involve multiple structures within the hoof. The T-ligament (an anatomical structure connecting the synovium of the distal interphalangeal joint, the digital flexor tendon sheath and the navicular bursa) is poorly described.Five pairs of equine cadaver distal forelimbs were collected from a slaughterhouse. Sagittal sections (medial, middle and lateral) were obtained and processed with Haematoxylin Eosin Safran, Unna's Orcein, and Picrosirius red stains.Histological assessment revealed that the T-ligament was covered by the surrounding synovia of the distal interphalangeal joint, the digital flexor tendon sheath and the navicular bursa. Its collagen content was lower (30.01%±10.15) than that of the collateral sesamoidean ligament (89.48%±5.8; P = .0008) and the middle phalanx (85.72%±3.67; P = .0008). Under polarized light microscopy, it showed a slight heterogeneous pattern of birefringence, with angle-related changes. Elastic fibres were more numerous (21.76%±8.72) than in the collateral sesamoidean ligament (0.28%±0.45), or deep digital flexor tendon (0.04%±0.02); and were more densely packed. Mean cell count was higher for the T-ligament than for other tissues (P = .0007). Blood vessels were identified in the T-ligament and were penetrating the deep digital flexor tendon (8/10 limbs, 5/5 horses).In conclusion, the T-ligament looked like a vinculum for the deep digital flexor tendon, with a central elastic core, surrounding loose connective tissue and blood vessels. It is not a ligament. Its clinical relevance still needs to be determined.

Effectiveness of steroid injection for hand psoriatic dactylitis: results from a multicentre prospective observational study.

To assess the effectiveness of steroid injection (local treatment, LT) into the digital flexor tendon sheath of dactylitis in psoriatic arthritis (PsA) patients as compared with systemic treatment (ST). Forty-six PsA patients with a total of 73 dactylitic fingers were assessed in an observational, multicentre, prospective study by the Leeds Dactylitis Index basic (LDI-b) score and evaluated for local pain (visual analogue scale-VAS pain) and functional impairment (VAS-FI). Steroid injection was proposed to all patients. Patients refusing LT were treated with oral NSAIDs. Both the groups continued baseline csDMARDs and/or corticosteroids therapy. The clinical outcomes were measured at baseline, 1month (T1) and 3months (T3). The reduction of VAS-pain, VAS-FI and LDI-b values was statistically significant higher in the LT group (24 patients, 38 dactylitic fingers) as compared with the ST group (22 patients, 35 dactylitic fingers), both at T1 (p < 0.001, p < 0.001 and p = 0.008, respectively) and at T3 (p < 0.001, p < 0.001 and p < 0.001, respectively). A clinically meaningful treatment response (defined as a contemporary reduction of at least 5 points in VAS-pain and VAS-FI or as values of VAS-pain and VAS-FI were both ≤ 2) was observed at T1 in 33 (87%) digits in LT group and in 6 (17%) digits in ST group (p < 0.001). At T3, clinical response improved significantly in both the groups, with significant difference (94% vs 31%, p < 0.001). For the first time, we show the effectiveness of steroid injection into the digital flexor tendon sheath in improving clinical aspects of hand psoriatic dactylitis. Key Points • Therapy with steroid injection (local treatment, LT), into the digital flexor tendon sheath for the treatment of active dactylitis in psoriatic arthritis patients, is more effective when compared with systemic treatment (ST) alone. • The reduction of VAS-pain, VAS-functional impairment (VAS-FI) and Leeds Dactylitis Index basic values was statistically significant higher in the LT group as compared with the ST group, both at T1and at T3. • A clinically meaningful response was observed at T1 in 87% of digits of patients treated with steroid injection and in 17% of digits of the systemic treatment group (p < 0.001). At T3, clinical response improved significantly in both the groups, with significant difference. • For the first time, findings from this study show that the use of steroid injections into the digital flexor tendon sheath for psoriatic dactylitis could be an effective and safe first-line therapy for psoriatic dactylitis.

Ultrasound findings in tendons and ligaments of lame sport horses competing or training in South Florida venues during the winter seasons of 2007 through 2016

SummaryKnowledge of common soft tissue lesions in sport horses in training should prove beneficial for evaluating lameness and developing training and management regimens to avoid injury and aid rehabilitation. Medical records were reviewed from 2007 to 2016 to describe tendon/ligament lesions in lame sport horses training and competing at the same venues during the winter show circuit and identified by lameness and ultrasonographic examinations. Season, discipline, breed, age, gender, limb and ultrasound findings were recorded. Descriptive statistics were used to describe the population of horses. Significance of association of gender, discipline and limb with lesion type was evaluated using chi‐squared analyses. Values were considered significant at P ≤ 0.05. Lesions were identified in 296 horses: 176 dressage and 120 hunter/jumpers. Ninety‐two horses (31%) had multiple lesions. Suspensory ligament lesion locations (n = 281) were categorised as proximal (n = 144), body (n = 22) and branches (n = 115). Superficial digital flexor tendon (SDFT; n = 37), deep digital flexor tendon (DDFT; n = 27), inferior check ligament (ICL; n = 34), digital flexor tendon sheath (n = 17), distal sesamoidean ligament (n = 10), lower limb collateral ligament (n = 14), carpal sheath (n = 2), superior check ligament (n = 2) and tarsal sheath (n = 1) lesions were noted. Remaining lesions identified were medial branch SDFT (n = 2), lateral branch SDFT (n = 2), palmar annular ligament (n = 3), lateral plantar ligament (n = 2) and inter‐sesamoidean ligament (n = 1). Rear limb proximal suspensory abnormalities, specifically the right hindlimb (n = 68), were significantly over‐represented (P = 0.03). Suspensory origin, suspensory branch, ICL, SDFT and DDFT accounted for 82% of the abnormal findings identified. SDFT, DDFT and ICL lesions were most often identified in the front limb. The lesion type and location may provide insight in assessing training regimens, patient monitoring and rehabilitation guidelines.

Cutaneous mastocytoma with eosinophilia and eosinophilic infiltration of the small intestine in an Arabian gelding

A 12-year-old Arabian gelding presented to the University of Adelaide for investigation of a firm subcutaneous mass, just proximal to the digital flexor tendon sheath of the right forelimb, that...

Postanaesthetic brachial compartmental syndrome in a horse

A 9-year-old Irish sports horse gelding was anaesthetised out-of-hours for management of digital flexor tendon sheath sepsis after a left hind foot penetration. In the postanaesthetic period, the patient manifested...

Epithelial inclusion cyst of the equine digital flexor tendon sheath: diagnosis by ultrasonography and magnetic resonance and successful treatment by tenoscopy

A six-year-old warmblood horse was presented with a longstanding frontlimb lameness with mild digital flexor tenosynovitis and swelling of the distomedial pastern. Ultrasonography and magnetic resonance revealed a dense mass lesion in the distal aspect of the digital flexor tendon sheath, with a partial lamellar architecture, absence of internal vascularization and adjacent smooth pressure osteolysis of the middle phalanx. After surgical excision, histopathology confirmed an epithelial inclusion cyst. Epithelial inclusion cysts, also known as keratinizing or follicular cysts, are expansile benign mass-like lesions of aberrant epidermal tissue. In the horse, they are known to occur in cutaneous and several non-cutaneous tissues. In the digital flexor tendon sheath, they have rarely been described. Given their often chronic presentation in this location, they may appear as an atypical dense mass on imaging, uncommon for cystic lesions. Complete tenoscopic removal, even for larger masses, is achievable and considered curative with good prognosis for return.

Improved diagnostic criteria for digital flexor tendon sheath pathology using contrast tenography.

Pathology of the digital flexor tendon sheath is a significant cause of lameness in the horse. Imaging is important to identify lesions and inform on prognosis prior to tenoscopic surgery. To use a large population to evaluate 1) the sensitivity and specificity of digital flexor tendon sheath (DFTS) contrast radiographs in diagnosing manica flexoria (MF) tears, deep digital flexor tendon (DDFT) tears and constriction of the palmar/plantar annular ligament (PAL) using novel criteria; 2) predisposition to pathology in signalment and limb affected. Multicentre retrospective cohort study. The medical records of 206 horses with lameness localised to the DFTS, contrast radiographs and subsequent tenoscopic surgery were reviewed. Breed and limb predispositions were evaluated for pathology of the DDFT, MF and PAL constriction. Contrast radiographs of the DFTS were reviewed by four masked operators and for each pathology the sensitivity, specificity and interobserver variability were calculated. Contrast tenography was a sensitive test for MF tears (92% confidence interval [CI] 88.4-94.4%; specificity 56%, CI 51.1-61.1%) and specific for diagnosing DDFT tears (73%, CI 68.6-76.8%; sensitivity 54%, CI 47.8-60.2%) but had a lower sensitivity (71%, CI 65.1-75.9% ) and specificity (45%, CI 39.1-52.0%) for PAL constriction. It had good to substantial interobserver agreement for MF and DDFT tears (Krippendorff's alpha 0.68 and 0.46 respectively). Ponies (57%) and cobs (58%) were significantly more likely to be affected with MF tears (other breeds 20-39%, P=0.003) and Thoroughbreds (50%), warmbloods (45%) and draught breeds (48%) were more likely to have DDFT tears (other breeds 22-34%, P=0.01). MF tears and PAL constriction were overrepresented in the hindlimbs compared to DDFT tears in forelimbs. No standardisation of contrast radiographs was possible. The subjectivity of diagnosis of PAL constriction may also have led to bias. Radiographs were read as JPEGS reducing ability to manipulate images. Contrast radiography of the DFTS is accurate in the pre-operative diagnosis of DFTS pathologies. Different pathologies are overrepresented in certain breeds and limbs.

Ultrasound-Guided Proximolateral Approach for Digital Flexor Tendon Sheath Injection in the Horse: A Cadaver Study

Abstract Objectives The aim of this study was to define a reliable ultrasound-guided proximolateral approach (PLA) for injection of the digital flexor tendon sheath (DFTS) in horses that would be as accurate as the landmark-guided basilar sesamoidean approach (BSA). Study Design Forty cadaveric limbs with no palpable effusion or DFTS abnormalities were randomly and evenly distributed between one senior (WRR) and one resident clinician (CRH) and between ultrasound-guided PLA and landmark-guided BSA groups. Limbs were injected with contrast, radiographed, and dissected. For each injection, the following was recorded: clinician, order of injection, number of attempts, if contrast was present within the DFTS, and if a structure other than the DFTS was penetrated. Results The ultrasound-guided PLA resulted in a greater number of successful injections into the DFTS than the landmark-guided BSA (19/20 vs. 16/20, respectively) with significantly fewer attempts (p = 0.03). The ultrasound-guided PLA also resulted in significantly less penetration of the surrounding soft tissue structures compared with the landmark-guided BSA (p = 0.02). Neither clinician experience nor injection number within the series was determined to have an effect on injection outcome. Conclusions The ultrasound-guided PLA to the DFTS is accurate and technically easy to perform. This approach should be considered for synoviocentesis of the DFTS, particularly in cases in which effusion is not present to reduce soft tissue trauma.

Surgical treatment of phlegmons of the digital flexor tendon sheaths at the early stage: Lavage by conventional open technique versus ultrasound-guided percutaneous technique

The aim of this work was to analyze the results of a percutaneous drainage technique with 2 catheters during surgical treatment of phlegmons of the finger flexor tendon sheath. Our series included 32 patients with a phlegmon of flexor tendon sheaths, including 19 men and 13 women, mean age 43.4years. The first 16 patients (group I) were treated by a conventional open technique for the lavage and drainage of the affected tendon sheath. The last 16 (group II) were treated by an ultrasound-guided percutaneous lavage technique with 2 catheters: one proximal and one distal. In the case of impermeability of the digital canal, conversion by open technique was carried out. In group II, the ultrasound-guided percutaneous lavage was 5 times successful. Failure of the proximal catheter alone was noted once, whereas failure of the distal catheter alone was noted 7 times. The failure of both catheters was noted 3 times. At a mean follow-up of 19.7 days, mean handgrip strength was 56.5% compared to the contralateral side in group I and 82% in group II (P<0.05). However, there was no significant difference for pain, QuickDASH, total active mobility between group I and group II. Pain was at 1.4/10 for group I and 1.4/10 for group II. QuickDASH was measured at 27/100 for group I and 22.27/100 for group II. Total active mobility was 227° for group I and 243° for group II. In conclusion, surgical treatment of the phlegmons of the finger flexor tendon sheath with an ultrasound-guided percutaneous lavage technique gives significantly better short-term grip strength than the conventional open technique.

Langetermijnresultaten van tenoscopische behandeling van letsels in de sesamschede: een retrospectieve studie van vijftig paarden

Letsels ter hoogte van structuren in de sesamschede kunnen de primaire oorzaak zijn van nietinfectieuze tenosynovitis, waarbij tenoscopie zowel diagnostisch als therapeutisch aangewend kan worden. In deze studie werden de gegevens van vijftig paarden uit de databank van de Faculteit Diergeneeskunde (UGent) verzameld, die in de periode van 2008 tot 2016 een tenoscopische behandeling van niet-infectieuze tenosynovitis van de sesamschede ondergingen. Telefonische follow-up informatie kon van veertig paarden worden bekomen. Bij springpaarden waren de voorbenen significant vaker aangetast dan de achterbenen, terwijl letsels bij paarden die niet voor jumping gebruikt werden, frequenter ter hoogte van de achterbenen werden vastgesteld (P=0,01). Letsels van de diepe buigpees vertegenwoordigden 45% van de gevallen terwijl er in 39% van de gevallen letsels ter hoogte van de manica flexoria waren. Uiteindelijk konden 27,7% van de paarden met laesies van de diepe buigpees en 53% paarden met laesies van de manica flexoria terug op hun oorspronkelijk niveau worden ingezet met een gemiddelde follow-upperiode van 4,6 ± 2,5 jaar.

Enhanced ultrasonographic imaging of the equine distal limb using saline injection of the digital flexor tendon sheath: A cadaver study

Injuries to the structures within the digital flexor tendon sheath (DFTS) can lead to lameness with a variable degree of effusion in horses. In some cases, effusion is absent or minimal, and this may be related to the chronicity and type of injury, or veterinary interventions. The purpose of this study was to determine if saline injection into the DFTS would improve ultrasonographic and magnetic resonance imaging of the distal limb without introducing artifact. Nine normal equine cadaver forelimbs were collected. Non-weight-bearing ultrasonographic and magnetic resonance imaging (MRI) examination of each limb was performed pre- and immediately post-injection of the DFTS.The presence of fluid in the DFTS significantly improved the delineation of the deep digital flexor tendon, manica flexoria, and straight distal sesamoidean ligament visualised using both ultrasonography and MRI (P<0.05). Significant improvement in visualisation of the margins of the superficial digital flexor tendon was noted only with MRI (P<0.05). Saline distension did not alter the size/shape of the intra- and extrathecal structures. The findings of this study support further evaluation of this imaging technique in clinical cases with minimal DFTS effusion.

Alternative surgical treatment for synovial ganglion cyst of the digital tendon sheath in one horse

SummaryA 6‐year‐old Highland pony gelding was presented with severe left fore (LF) limb lameness of acute onset. The lameness occurred concomitantly with mild digital flexor tendon sheath (DFTS) effusion and focal painful swelling on the lateral aspect of the LF fetlock region. Clinical examination and diagnostic analgesia localised the lameness to the fetlock region and on ultrasound, a cyst‐like structure filled with anaechoic fluid was detected just proximal to the lateral sesamoid bone, at the proximo‐lateral aspect of the DFTS and adjacent to the lateral neurovascular bundle. Communication between the cyst‐like structure and the DFTS was suspected ultrasonographically and then confirmed with contrast tenography. Tenoscopic examination of the LF DFTS was performed and the communication between the fluid‐filled structure and the synovial cavity was detected. The defect in the DFTS wall was enlarged tenoscopically and the lining of the cyst‐like structure was debrided. The horse recovered well post‐operatively and was back in work with no evident lameness 8 months after surgery. This alternative minimally invasive surgical treatment had an excellent outcome and has the advantage of reducing the risk associated with en bloc resection.