Rupture of the Vinculum in Association with Tendon Injury within the Digital Flexor Tendon Sheath in Two HorsesJournal of Equine Veterinary Science


Kathryn Rose Owen, Guy J. Hinnigan, Ellen R. Singer


Mechanism of Cell Death in Inflamed Superficial Digital Flexor Tendon in the Horse

Y. Hosaka, H. Teraoka, E. Yamamoto, H. Ueda, K. Takehana

Flexor Tendon Injury

Linda J. Klein

Flexor tendon injuries

J.W. Strickland





RCV hurst t between the palmar/plantar border of the superficial digital flexor tendon and the adjacent palmar/plantar annular ligament was identified in combination with other tendon pathology within the digital flexor tendon sheath. This tenoscopic finding has not been described previously in the literature.  2012 Elsevier Inc. All rights reserved. outer one lines the canal in which the tendon lies (parietal layer). The two layers are continuous along a fold termed the mesotendon [1,5]. Mesotendons extend from the proximomedial and proximolateral margins of the deep digital flexor tendon (DDFT) to the adjacent synovial 2. Case Presentation 2.1. History 2.1.1. Case 1

A 7-year-old Appaloosa gelding used for hunting presented with a history of a mild left forelimb (LF) lameness of 1-month duration. The lameness resolved with rest;

V age:

Journal of Equine Veterinary ScCorresponding author at: Kathryn Rose Owen, BVSc, CertES(Orth),A number of terms have been used to describe the synovial reflections that exist between the synovial lining of the digital flexor tendon sheath (DFTS) and the digital flexor tendons, which divide the sheath into compartments. These terms include mesotenons [1,2], mesotendons [1,3,4], and vinculae [1,2], and they are often used interchangeably in texts, which can be confusing to the reader.

The synovial sheath is a sac that is folded around the tendon so that two layers can be distinguished: the inner one (visceral layer) is adherent to the tendon, whereas the [2]. The DDFT also has a mesotendon that attaches from the palmar/plantar surface at the level of the proximal interphalangeal joint to the synovial membrane lining palmar/ plantar at midline [3,6].

In areas of great mobility within the synovial sheaths, the nerve and blood supply to the tendons is through a modified mesotendon, termed a vinculum [1]. The sagittal, adhesion-like mesotendon between the superficial digital flexor tendon (SDFT) and palmar/plantar annular ligament (PAL) within the DFTS is referred to as the vinculum of the SDFT [6] (Fig. 1).Received in revised form 1 April 2012

Accepted 10 April 2012

Available online 3 August 2012






Tenoscopy 1. IntroductionMRCVS, Oakhill Veterinary Centre, Langley lane, Goos 2JQ, UK.

E-mail address: (K.R. Owen). 0737-0806/$ - see front matter  2012 Elsevier Inc. A doi:10.1016/j.jevs.2012.04.006membrane lining within the proximal recess of the DFTSArticle history:

Received 15 December 2011The following report documents an unusual anatomical finding in two cases of aseptic tenosynovitis of the digital flexor tendon sheath. Disruption of the vinculum attachmentCase Report

Rupture of the Vinculum in Associa the Digital Flexor Tendon Sheath in

Kathryn Rose Owen BVSc, CertES(Orth), MRC

Ellen R. Singer DCM, DVSc, DipACVS/ECVS, M

Musculoskeletal and Locomotion Research Group, University of Liverpool, Lea a r t i c l e i n f o a b s t r a c

Journal of Equine journal homepnargh, Preston, PR3 ll rights reserved.n with Tendon Injury within o Horses

Guy J. Hinnigan BVSc, CertES(Orth), MRCVS,


Campus, Neston, Wirral, UK eterinary Science ience 32 (2012) 851-857however, when exercise was reintroduced, the lameness and DFTS effusion recurred. Preliminary radiography and e Veteultrasonography of the metacarpophalangeal joint region, performed by the referring veterinarian, revealed no significant abnormalities. 2.1.2. Case 2

A 13-year-old Cob gelding used for general purpose riding presented with a history of a moderate right hind limb (RH) lameness of 4 months’ duration. Intra-articular medication of the distal tarsal joints, performed by the referring veterinarian, owing to a history of distal tarsal

Fig. 1. A line drawing of the anatomy of the palmar fetlock region (in transverse section) of a horse at the level of the proximal sesamoid bones (PSBs). This shows the location of the vinculum of the superficial digital flexor tendon (SDFT). Yellow dashed arrow, digital flexor tendon sheath; Red solid arrow, vinculum; a, deep digital flexor tendon; b, SDFT; c, manica flexoria; d, PSB; e, third metacarpal bone.

K.R. Owen et al. / Journal of Equin852joint osteoarthritis failed to improve the lameness. An abaxial sesamoid nerve block, performed at the level of the proximal sesamoid bones (PSBs), also failed to produce a significant improvement in the degree of lameness observed. 2.2. Clinical Findings

A prominent convex swelling of the palmar/plantar fetlock region at the level of the PAL was accompanied by a moderate effusion of the DFTS in both cases. 2.2.1. Case 1

The horse showed mild resentment to firm digital palpation of the PAL and DFTS areas. The horse showed a grade 3/10 (0 ¼ sound, 10 ¼ non-weight-bearing [7]) LF lameness when trotted in a straight line on a smooth hard surface. When lunged on a soft surface, the horse showed a 3/10 LF lameness on the left rein and a 2/10 LF lameness on the right rein. When lunged on a hard surface, the degree of lameness increased to 4/10 on the LF on both reins. The lameness was exacerbated by distal limb flexion of the LF. 2.2.2. Case 2

The horse showed a 5/10 RH lameness when trotted in a straight line on a smooth hard surface, followed by a slight deterioration to a 6/10 RH lameness on the rightrein on the lunge. The lameness was exacerbated by both proximal and distal limb flexions of the RH. 2.3. Diagnostic Techniques 2.3.1. Radiography Case 1. Five standard radiographicprojectionsof the metacarpophalangeal joint were evaluated (lateromedial, flexed lateromedial, dorsopalmar, dorsal-45-lateralpalmaromedial, and dorsal-45-medial-palmarolateral obliques). No significant radiographic abnormalities were detected. 2.3.2. Diagnostic Anesthesia

Diagnostic anesthesia was not performed in case 1 owing to the acute onset of lameness and associated DFTS effusion. In case 2, anesthesia of the medial and lateral plantar nerves of the RH was performed at a level 1 cm proximal to the level of the distal second and fourth metatarsal bones, using 3 mL of 2.0% w/v mepivacaine hydrochloride (Intra-epicaine, Arnolds Veterinary Products,