Accessory Ligament Of The Deep Digital Flexor Tendon Research Articles

Accessory Ligament of the Deep Digital Flexor Tendon of the Horse Forelimb and Its Relationship with the Superficial Digital Flexor Tendon: A Plastination, Histological, and Morphometry Study.

The accessory ligament of the deep digital flexor tendon (AL-DDFT) plays a crucial role in the stay apparatus of the horse. This study aimed to investigate the anatomical relationship between the AL-DDFT, the superficial digital flexor tendon (SDFT), and other structures in the metacarpal region. Sixteen distal forelimbs from eight horses, aged 1 to 6 years, were evaluated through macroscopic, microscopic, and morphometric analyses, utilizing detailed dissection, E12 plastinated sections, and histological analysis. During lateral dissection, a connection was observed between the AL-DDFT and the SDFT. Histological evaluation revealed that this connection was a fibrous band (FB), extending the common synovial sheath (CSS) to the SDFT, along with associated collagen fibrils of the epiligament and peritenon. Additionally, two distinct forms of the AL-DDFT were identified, Type I and Type II, with Type II showing a greater cross-sectional area (CSA) than Type I. While numerous morphological and morphometric studies have explored the AL-DDFT and related structures, research incorporating plastination-based morphological and histological evaluations remains scarce. The findings provide valuable insights for both the morphological and clinical assessment of structures within the metacarpal region.

Desmitis of the accessory ligament of the deep digital flexor tendon in the forelimb: A retrospective case study of 91 horses.

Desmitis of the accessory ligament of the deep digital flexor tendon (ALDDFT) is a commonly reported injury. Despite the commonality of this injury, the literature is limited to small case series, with the reported success following treatment varying from 18% to 75%. To identify the prognosis and factors associated with a return to work following ALDDFT injury. Retrospective case series. Medical records of horses from four equine hospitals (January 2000 and December 2018) with a diagnosis of desmitis of ALDDFT were reviewed. Data retrieved included case detail, use, history, lameness treatment and follow-up. Success was defined as returning to work. Backward stepwise logistic regression was used to identify variables significantly associated with return to work. Ninety-one horses were included. The mean age was 13.5 years (standard deviation 4.9 years). Thirty-four percent (28/91) of horses were sound at the initial presentation. Sixty-eight percent (62/91) of horses were managed using controlled exercise alone, 28% (29/91) were treated with intra-lesional injection, therapeutic ultrasound, extracorporeal shockwave therapy or desmectomy of the ALDDFT and 3% (3/91) were euthanased without treatment. Sixty-four percent (54/85) of horses returned to work. Horses that were lame at follow-up were less likely to return to work (odds ratio [OR] 107.93, 95% confidence interval [CI] 20.06-580.61, p < 0.001) than those that returned to soundness. Identification of adhesions on ultrasonography was also associated with having reduced odds for return to work when compared to horses without adhesions (OR 0.10, 95% CI 0.01-0.76, p = 0.03). Retrospective nature of the study, the potential of selection bias with regards to follow-up. Sixty-four percent (54/85) of horses returned to work following injury of the ALDDFT. Persistence of lameness and adhesion formation were significantly associated with a poor outcome.

Neurovascular variations in the proximal plantar metatarsal region of the horse.

Neurovascular variation may be relevant when performing surgical techniques to the proximal plantar metatarsal region. To document variations in the neurovascular anatomy of the proximal plantar metatarsal region and study the relationship of the neurovascular components to each other and other structures located in this area. Descriptive anatomical study. Paired cadaver hind limbs from 15 horses were dissected from the distal tibia to the metatarsophalangeal joint. Deep branch of the lateral plantar nerve (DBLPN) length, location of its origin from the lateral plantar nerve (LPN), individual DBLPN ramifications into the suspensory ligament (SL) and relationship of the DBLPN to the plantar arch and accessory ligament of the deep digital flexor tendon (ALDDFT) were recorded. Mean DBLPN length was 5.8±1.7cm with the nerve arising 3.7±1.5cm proximal to the head of the fourth metatarsal bone (MTIV). There was a median of three individual DBLPN ramifications (range 2-6) entering the SL. There were no significant left/right differences. In 57% (CI 39%-74%; n=17) limbs, the deep plantar arch was superficial to the DBLPN, whereas in 33% (CI 16%-50%; n=10) limbs, the DBLPN passed between the venous and arterial components of the arch. In 10% (CI 1%-20%; n=3) limbs, the deep plantar arch was deep to the DBLPN. In 67% (CI 50%-84%; n=20) limbs, the DBLPN was superficial to the ALDDFT, whereas in 33% (CI 16%-50%; n=10) limbs, the nerve ran deep to the ALDDFT. An additional branch from the LPN was noted in one limb. Limbs were used from horses with unknown clinical history. Anatomical variation, in particular the relationship of the DBLPN and deep metatarsal fascia to the deep plantar arch and the ALDDFT is an important consideration when undertaking surgical approaches to the proximal plantar metatarsal region.

Long-term athletic performance in sport horses after desmotomy of the accessory ligament of the deep digital flexor tendon.

Outcome after desmotomy of the accessory ligament of the deep digital flexor tendon (AL-DDFT) to treat flexural deformity of the distal interphalangeal joint has been reported to be excellent. However, no studies have compared long-term athletic performance of sport horses exposed to desmotomy of the AL-DDFT to that of matched controls. The objective of this study is to compare long-term athletic performance in sports horses subjected to desmotomy of the AL-DDFT with the performance of matched controls. This is an observational multicentre retrospective matched cohort study. Records from horses undergoing desmotomy of the AL-DDFT between 2004 and 2015 were reviewed. Various databases were used to identify age-matched siblings as unexposed controls and data on the horses' athletic careers. Seventy-four exposed and 194 matched unexposed horses were included. Although not significantly different, the proportion of exposed horses entering competition (28%, 95% CI 16%-38%) had a substantial risk difference compared with the proportion of unexposed horses entering competition (38%, 95% CI 26%-44%) (P=.2). Career longevity was significantly better for unexposed (15.6 competitions [95% CI 10.7-22.5] over a median of 570days [IQR 210-1340]) than for exposed horses (9.7 competitions [95% CI 6.4-14.6] over a median of 219days [IQR 2-1159] for horses operated in one limb and 6.1 competitions [95% CI 3.6-9.9] over a median of 446days [IQR 23-603days] for horses operated in two limbs, P<.001). Age at surgery and whether the condition was unilateral or bilateral did not affect chance of competing. Small sample size, varying quality of medical records, stage of contraction not noted in many records and missing information on reasons for not entering into competition. Desmotomy of the AL-DDFT is associated with decreased long-term athletic performance in sport horses compared with matched unexposed horses.

Retrospective analysis of distal limb conformation and lameness in mature horses after desmotomy of the accessory ligament of the deep digital flexor tendon for management of a flexural deformity

SummaryMature horses that present with flexural deformity of the distal interphalangeal joint and lameness isolated to the foot may obtain long‐term benefits from desmotomy of the accessory ligament of the deep digital flexor tendon (ALDDFT). This retrospective analysis of medical records and radiographs included 13 horses, aged ≥2 years, presented for lameness isolated to the hoof region and diagnosed with flexural deformity of the distal interphalangeal joint. Radiographic angles of the hoof and distal interphalangeal joint and lameness scores were compared before and after desmotomy of the ALDDFT. Follow‐up data including the ability to perform the intended use were obtained at least one year after surgery. There was improvement in the angle between the dorsal aspect of the third phalanx and the weightbearing surface of the hoof, improved alignment between the dorsal hoof wall and dorsal aspect of the third phalanx, and improved alignment of the distal interphalangeal joint. Lameness was decreased in 9/13 horses and 10/13 horses were performing at their level of intended use. Evidence of improved hoof conformation and lameness following desmotomy of the ALDDFT in lame horses with flexural deformity of the distal interphalangeal joint would indicate this procedure should be considered in mature horses.

Desmotomy of the accessory ligament of the deep digital flexor tendon for treatment of chronic deep digital flexor tendinopathy in three Quarter Horses

SummaryEffective treatments for horses diagnosed with severe deep digital flexor (DDF) tendinopathy are limited. In this study, three Quarter Horses diagnosed with severe bilateral DDF tendinopathy underwent bilateral desmotomy of the accessory ligament of the DDF tendon after failing to respond to conservative therapy. Lameness markedly improved in all three horses. Given that severe DDF tendinopathy is typically associated with persistent or recurrent lameness, desmotomy of the accessory ligament of the DDF tendon might be a treatment option to alleviate lameness in horses with DDF tendinopathy. This treatment option appears promising; however, a larger number of cases is necessary to support the results in these three horses.

Evaluation of mean echogenicity of tendons and ligaments of the metacarpal region in neonatal foals: A preliminary study

The aims of this research were to evaluate mean echogenicity (ME) of the deep and superficial digital flexor tendons (DDFT and SDFT), the interosseous muscle (IM), and the accessory ligament of the deep digital flexor tendon (ALDDFT) of the metacarpal region in neonatal foals, and determine the effect of sex, side and body weight on this quantitative ultrasonographic evaluation. Thirteen orthopedically sound neonatal foals were examined. Four areas of study (1A, 1B, 2A, 2B) were identified. Transverse scans of the DDFT, SDFT, IM and ALDDFT were obtained, recorded, and analyzed. The most echogenic structures were the ALDDFT and DDFT, while the SDFT was significantly less echogenic than all other structures (P<0.05). No influence of sex, forelimb, or body weight was observed. The echogenicity of the tenodesmic structures of foals partially overlapped that reported in the metacarpal region in adult horses, except for IM.

Concurrent proximal suspensory desmopathy and injury of the proximal aspect of the accessory ligament of the deep digital flexor tendon in forelimbs or hindlimbs in 19 horses

SummaryClinical features of proximal suspensory desmopathy (PSD) and concurrent injury of the proximal aspect of the accessory ligament of the deep digital flexor tendon (ALDDFT) have not been documented. The objectives were to describe clinical signs and diagnosis. This was a retrospective study. Patient details, lame limb(s), response to diagnostic analgesia, and radiographic and ultrasonographic findings were recorded. PSD and injury of the proximal aspect of the ALDDFT were identified in 19 horses, 14 with forelimb lameness (unilateral 5, bilateral 9) and 5 with hindlimb lameness (unilateral 2, bilateral 3). Localising clinical signs were seen in 7/31 lame limbs (subtle thickening in the region of the ALDDFT [n = 3], pain on palpation of the body of the suspensory ligament (SL) [n = 6], heat in the proximal metacarpal or metatarsal region [n = 2]). Forelimb lameness was abolished by perineural analgesia of the palmar metacarpal (subcarpal) nerves in 17/23 limbs. In the remaining limbs intra‐articular analgesia of the middle carpal joint (n = 2) or an ulnar nerve block (n = 4) were required to eliminate the lameness. Hindlimb lameness was abolished by perineural analgesia of the deep branch of the lateral plantar nerve (n = 2) or local infiltration of the proximal plantar aspect of the metatarsus (n = 3); a tibial nerve block resolved lameness in the remaining 3 limbs. Lesions of the SL and of the ALDDFT were characterised ultrasonographically by enlargement, heterogeneous echogenicity and loss of long linear echoes in longitudinal images. In 3 horses adhesions between the ALDDFT and the SL were identified post mortem. Close apposition of these structures seen ultrasonographically may indicate adhesion formation. It was concluded that the clinical features of PSD and concurrent injury of the ALDDFT are similar to those for PSD alone, highlighting the need for comprehensive and systematic ultrasonographic assessment.

Concurrent Proximal Suspensory Desmopathy And Injury of the Proximal Aspect of the Accessory Ligament of the Deep Digital Flexor Tendon in Forelimbs and Hindlimbs

Reasons for performing studyThere are no reports of proximal suspensory desmopathy (PSD) and concurrent injuries of the proximal aspect of the accessory ligament of the deep digital flexor tendon (ALDDFT).ObjectivesTo describe clinical features, response to local analgesia and ultrasonographic features.Study designRetrospective study.MethodsReview of case records, January 2009–2014.ResultsThere were 8 horses with forelimb lameness, 4 unilateral and 4 bilateral (2 with bilateral injuries of the suspensory ligament [SL] and ALDDFT and 2 with PSD and injury of the ALDDFT in one limb and injury of the ALDDFT alone in the other). One horse had pain on palpation of the proximal aspect of the ALDDFT. Lameness was abolished by palmar metacarpal (subcarpal) nerve blocks in 10/12 limbs; in 2 limbs an ulnar nerve block was required to abolish lameness. There were 5 horses with bilateral hindlimb lameness; concurrent desmopathy of the ALDDFT and PSD was identified in one horse. In the other 4 horses there was a history of bilateral PSD which had undergone treatment. Recurrent lameness was associated with unilateral (n = 3) or bilateral (n = 1) PSD and desmopathy of the ALDDFT. In 2 horses there was soft tissue swelling in the proximomedial aspect of the metatarsus in the region of the ALDDFT. Lameness was abolished by local infiltration of mepivacaine in the proximoplantar aspect of the metatarsus in 3 limbs; in one limb a tibial nerve block was required to eliminate lameness. In all horses lesions were characterised ultrasonographically by enlargement of both the ALDDFT and the proximal aspect of the SL and a diffuse decrease in echogenicity. There was echogenic material between the SL and ALDDFT in 5 limbs.ConclusionsAll soft tissue structures in the proximal aspect of the metacarpus/metatarsus should be evaluated ultrasonographically if pain is localised to this area.Ethical animal research: The study was approved by the Ethical Review Committee of the Animal Health Trust and there was informed owner consent. Sources of funding: None. Competing interests: None.

Desmitis of the Accessory Ligament of the Equine Deep Digital Flexor Tendon: A Regenerative Approach

Background: Desmitis of the accessory ligament of the deep digital flexor tendon (ALDDFT) is a very common problem in different breeds of sport horses, with an inability to heal adequately after conservative therapy in many cases. However, the treatment of different kinds of tendon lesions with platelet-rich plasma (PRP), mesenchymal stem cells (MSCs), or even tenogenic induced MSCs have been reported with promising results. Methods: After MSC and PRP isolation of the peripheral blood (PB) of a donor horse, tenogenic induction of the MSCs (Tendo-Cell®) was confirmed, and samples were microbiologically tested and frozen. Adverse and clinical effects (macroscopic noticeable swelling, lameness and ultrasound imaging) of PRP (n=4), or Tendo-Cell® (n=4) were evaluated after a single intralesional injection in the ALDDFT in 8 horses. For each case, two independent veterinary practitioners were asked to give a score from 0-5, at approximately 6 weeks and 4 months after treatment (0=no ultrasonographic improvement and 5=90-100% improvement, or (nearly) no ultrasonographic abnormalities, the ligament has (almost) no hypo-echoic foci, and (nearly) the same fiber orientation as the contralateral ligament). Results: At approximately 6 weeks post injection, the ultrasound images of all 4 horses treated with PRP only slightly improved. Therefore, a score 2/5 was given by the two attending veterinarians to all 4 patients. In the Tendo- Cell® treated group, on the other hand, all 4 horses received a score 4/5 by the same veterinarians at 6 weeks after intralesional injection. This implicates that the lesions improved about 80% on the ultrasound images, which was much better than the 40% improvement in the PRP treated group. Conclusion: This study reports a positive clinical and ultrasonographical outcome after tenogenic induced MSC (Tendo-Cell®) treatment of desmitis of the equine ALDDFT, whereas no considerable improvements could be noticed after treatment with allogenic PRP.

Proximal injuries of the accessory ligament of the deep digital flexor tendon in forelimbs and hindlimbs: 12 horses (2006–2010)

SummaryThere have been no detailed ultrasonographic descriptions of injuries of the accessory ligament of the deep digital flexor tendon (ALDDFT) in the carpal and proximal metacarpal and tarsal and proximal metatarsal regions. The aims of this study were to describe the: 1) normal ultrasonographic appearance of the proximal aspect of the ALDDFT in fore‐ and hindlimbs and 2) clinical and ultrasonographic features of proximal injuries of the ALDDFT in both fore‐ and hindlimbs. The proximal aspects of the ALDDFT of both fore‐ and hindlimbs of 10 horses free from lameness were examined ultrasonographically. Clinical records of 12 horses examined between January 2006 and December 2010 with proximal injuries of the ALDDFT were reviewed. All 4 horses with proximal lesions of the ALDDFT in a forelimb had no localising clinical signs and diagnostic analgesia was required to localise the source of pain. Eight horses with recent onset hindlimb lameness had oedematous swelling in the proximoplantaromedial aspect of the metatarsal region (n = 7) or more generalised thickening in the region of the proximal aspect of the ALDDFT (n = 1). Diagnosis was confirmed ultrasonographically in all horses. One horse was retired for unrelated reasons. One of 3 horses with forelimb lameness returned to full athletic function. Four of 6 horses with hindlimb lameness returned to work; the remaining 2 horses resumed work, but experienced recurrent injury of the ALDDFT. Proximal injuries of the ALDDFT should be considered as a cause of either fore‐ or hindlimb lameness, even in the absence of gross palpable abnormalities.

Effects of Extracorporeal Shock Wave Therapy on Desmitis of the Accessory Ligament of the Deep Digital Flexor Tendon in the Horse

To evaluate the effects of extracorporeal shock wave therapy (ESWT) on collagenase-induced lesions in the accessory ligament of the deep digital flexor tendon (ALDDFT) of horses. Paired, blinded controlled study. Eight Thoroughbred horses (3 mares, 5 geldings; mean ± SD weight, 464 ± 26 kg, mean age, 8 ± 1.7 years). Lesions were created in both ALDDFTs of all horses by injection of 2 × 10(3) IU of collagenase type I. Percent lesion and structure (fiber alignment and echogenicity) were quantified with ultrasonographic imaging 3, 6, and 9 weeks after collagenase injection. After ultrasound examinations, ESWT (1000 shocks at 0.15 mJ/mm2) was applied to 1 ALDDFT in each horse. ALDDFT were harvested 15 weeks after collagenase injection and the microstructure, mRNA levels of collagen types I and III, and collagen and glycosaminoglycan content were evaluated. There were no differences in percent lesion, echogenicity, or fiber alignment between control- and ESWT-treated ligaments at each evaluation time; however, compared with 3-week values, there was a significant increase in percent lesion and echogenicity for EWST treated ligaments at 6 weeks and significant decrease in both variables for treated and control ligaments at 12 weeks. Fiber alignment improved significantly at 9 weeks in controls and at 12 weeks in treated and control ligaments. Collagen type I mRNA levels were significantly higher in the ESWT treatment group compared with the control group 15 weeks after collagenase injection though differences in other mRNA levels, microstructure, and composition were not significant. Our results do not support an effect of ESWT on collagenase-induced lesions in the equine ALDDFT.

Desmotomy of the Accessory Ligament of the Deep Digital Flexor Tendon in the Forelimb of 24 Horses 2 Years and Older

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

Evaluation of a Tenoscopic Approach for Desmotomy of the Accessory Ligament of the Deep Digital Flexor Tendon in Horses

To develop a tenoscopic approach for desmotomy of the accessory ligament of the deep digital flexor tendon (AL-DDFT) in horses. Experimental. Cadaveric forelimbs (n=10) and 4 forelimbs from 2 horses anesthetized for terminal teaching procedures, and 12 forelimbs of 6 experimental horses. Saline distention of the carpal flexor sheath facilitated insertion of an arthroscope into the distal medial aspect of the sheath between the AL-DDFT and deep digital flexor tendon (DDFT). Location of an instrument portal on the lateral aspect of the metacarpus was identified with a needle. The lateral aspect of the AL-DDFT was transected and the arthroscope and instrument were switched to transect the remaining fibers on the medial aspect. Cadaveric specimens were dissected for evaluation. Experimental horses were monitored for 30 days postoperatively. Minor complications including incomplete division of the AL-DDFT and shallow incision into the suspensory ligament were observed in some cadaver specimens. The AL-DDFT was completely transected in all experimental horses with no suspensory ligament damage. Mean±SD surgical time (incision to skin closure) was 28.3±11.8 minutes. On ultrasonographic examination, transection of the AL-DDFT was complete in all experimental horses. Minor DDFT fiber disruption was noted in 1 limb during ultrasound examination at day 30. A tenoscopic approach through the carpal flexor sheath provided adequate access for desmotomy of the AL-DDFT.

Anatomical, magnetic resonance imaging and histological findings in the accessory ligament of the deep digital flexor tendon of forelimbs in nonlame horses

Detailed magnetic resonance imaging (MRI) and histological appearances of the accessory ligament of the deep digital flexor tendon (AL-DDFT) have not been documented previously in detail. To: 1) describe anatomical connections between the AL-DDFT and adjacent structures; 2) describe high-field and low-field MRI and histological appearances of the AL-DDFT in the forelimb of horses with no carpal or proximal metacarpal pain; and 3) assess the relationship between age, breed, gender, height, weight and MRI findings. Ten forelimbs were dissected to determine anatomical relationships among the AL-DDFT and adjacent structures. High- and low-field MR images of the AL-DDFT and related structures from 29 cadaver limbs of nonlame horses were analysed subjectively and objectively. The relationship between age, breed, gender, height, weight and MRI findings was assessed using a Chi-squared test. Twelve ALs-DDFT were examined histologically. Histological and MRI findings were compared subjectively. Fibrous bundles were seen between the AL-DDFT and the lateral aspect of the superficial digital flexor tendon (n = 9) and the DDFT (n = 2). The AL-DDFT had low to intermediate signal intensity in most limbs in most high-field and low-field MRI sequences. In 69% of limbs, oblique bands of higher signal intensity than the rest of the ligament were identified in high-field images of the AL-DDFT. The cross-sectional area of the AL-DDFT in the proximal 7 cm of the metacarpal region ranged from 68.1-299 mm(2) . There was no significant relationship between age, gender, weight or height and either the cross-sectional area of the AL-DDFT or the presence of oblique higher signal intensity bands. Histological examination revealed that the AL-DDFT had thick collagen bundles arranged in large crimps and sometimes crossing in oblique directions. The cellularity was greater than in the deep digital flexor tendon in all limbs. The large variability in the MRI appearance and size of the AL-DDFT in nonlame horses should be borne in mind when interpreting MR images of lame horses.

Two clinical manifestations of desmopathy of the accessory ligament of the deep digital flexor tendon in the hindlimb of 23 horses

Desmopathy of the accessory ligament of the deep digital flexor tendon (ALDDFT) in the hindlimb is an unusual cause of lameness in horses, and reports of the condition are sparse. To describe the clinical and ultrasonographic findings, therapy and outcome of 23 horses treated for desmopathy of the ALDDFT in the hindlimb. Records of 23 horses with ultrasonographic evidence of desmopathy of the ALDDFT in one or both hindlimbs from 3 referral centres were reviewed retrospectively. Age, breed, sex, duration and nature of clinical signs, results of clinical and lameness examinations, treatment and outcome were recorded. In 13 horses (Group A), there was an acute onset of unilateral lameness. Ten horses (Group B) had an insidious or sudden onset of postural abnormality. There were 10 cobs, 5 British native-breed ponies and 8 horses of various larger breeds. Twenty horses were used for general purposes, and mean age was 12 years. Enlargement of the ALDDFT in the affected hindlimb(s) was identified in all horses. In 44% of horses, ultrasonographic abnormalities were localised to part of the ALDDFT. Treatment included box-rest and controlled exercise, and 10 horses were subjected to desmotomy or desmectomy of the ALDDFT. Seventy-three percent of horses in Group A returned to full function, while 90% of those in Group B remained lame. Two distinct clinical conditions are associated with the ALDDFT of the hindlimb. Traumatically induced injury resulting in acute onset lameness appears to have a favourable prognosis, with most horses returning to previous work. However, postural changes, once present, are irreversible and indicate a poor prognosis. Desmopathy of the ALDDFT should be recognised as a potential cause of hindlimb lameness and this study provides clinical and prognostic information. Knuckling and/or semiflexion of the metatarsophalangeal joint may accompany the condition; therefore, if a horse is presented with a flexural deformity of this joint, desmopathy of the ALDDFT should be considered as a primary differential diagnosis.

Morphometric data on the accessory ligament of the deep digital flexor tendon in the equine hindlimb

Desmopathy of the accessory ligament of the deep digital flexor tendon (ALDDFT) in the hindlimb has recently been described as a cause of lameness in horses. However, there is limited morphometric data on this ligament. In the present study, the ALDDFT was carefully dissected in 165 hindlimbs that were collected from an abattoir. Length, width (lateral-to-medial) and thickness (plantar-to-dorsal) of the ligament were measured. It was found that the ALDDFT may be absent in a minority of horses, but when it was present the general morphology was variable. The ALDDFT can be a single rectilinear structure ranging from slender or poorly developed to quite large and can be divided, in part or in its entirety, into two or three bundles.

Desmectomy of a septic accessory ligament of the deep digital flexor tendon in the hindlimb of a horse under standing sedation

SummaryA horse presented with a discharging wound over the proximal aspect of the right metatarsal region. Examination, radiography and ultrasonography diagnosed a septic process within the accessory ligament of the deep digital flexor tendon (ALDDFT). Due to previous unsuccessful treatment with systemic antibiotics as well as financial restrictions, an ALDDFT desmectomy was performed with the patient under standing sedation and local analgesia. Histopathology confirmed the septic process within the affected structure. The patient made a rapid recovery and was discharged from the hospital 7 days post operatively and 2 years later was still in full work. This report describes the first case of infective hindlimb ALDDFT and the first desmectomy of this structure performed under standing sedation.

Acquired flexural deformity of the metacarpophalangeal joint in five horses associated with tendonous damage in the paimar metacarpus

Five cases of acquired flexural deformity of the metacarpophalangeal joint (MCP) in older horses and ponies were studied. The mean age of affected horses was 14.8 years. Four deformities developed...

Effects of experimental desmotomy on material properties and histomorphologic and ultrasonographic features of the accessory ligament of the deep digital flexor tendon in clinically normal horses

Abstract Objective To evaluate posttrauma biomechanical behavior of the scar attributable to desmotomy of the accessory ligament of the deep digital flexor tendon (AL-DDFT), compared with the histomorphologic and ultrasonographic appearance. Animals 5 Standardbred trotters. Procedure Gross appearance, length, cross-sectional area (CSA), in vitro material properties, and ultrasonographic and histomorphologic features were studied 6 months after desmotomy. Tensile tests were conducted, with forces and elongation simultaneously recorded. Surgically treated limbs were compared with nontreated contralateral limbs. Results The CSA of the treated ligaments was increased threefold, and treated ligaments were 1 cm longer than control ligaments. In the healed AL-DDFT, stress and material stiffness were approximately a third of those values for controls. The functional characteristics, force and elongation at failure, reached 80% of control values. Ultrasonographic and the histomorphologic examination of the scar tissue revealed high amounts of randomly oriented collagen. Conclusion From the ultrasonographic and histomorphologic findings and the material properties, it was concluded that the scar tissue was of inferior quality. However, the functional properties had been restored for the most part by increase of the CSA. The length increase may lead to strain relief in the AL-DDFT after desmotomy. Clinical Relevance Desmotomy is recommended as treatment for chronic desmitis. (Am J Vet Res 1998;59:352–358)