Equis ISSN 2398-2977

Musculoskeletal: flexural deformity

Synonym(s): Contracted tendon

Contributor(s): Steve Adair, Helen Herinckx, Chris Whitton, Laura Quiney

Introduction

  • Abnormal angular deviation of the limb in the sagittal plane, usually abnormal flexion of one or more joints, and less commonly hyperextension.
  • Cause: congenital (multifactorial) or acquired (relative shortening of the musculotendinous unit).
  • Signs: hyperflexion of joint(s), also includes flexor tendon flaccidity → hyperextension.
  • Most commonly affects:
  • Diagnosis: physical examination +/- radiography, ultrasonography, serology.
  • Treatment: conservative, medical, surgery, farriery.
  • Prognosis: good to poor depending on degree of abnormality, anatomic location of flexural deformity and response to treatment.
Print off the Owner factsheet on Flexural limb deformities to give to your clients.

Pathogenesis

Etiology

Congenital

  • Often unknown/not understood, probably multifactorial.
  • Genetic factors.
  • Ingestion of locoweed, Sudan grass, sweet pea by the mare during gestation.
  • Equine Influenza (exposure to mare) Equine influenza.
  • Equine goiter.
  • Prematurity/dysmaturity.
  • Arthrogryposis (deformity of multiple limbs and the head and neck).
  • Uterine malposition has been proposed but is unproven.
  • Possibly defects in elastic or collagen formation (sweet pea ingestion by the mare).

Acquired

  • Developmental orthopedic disease.
  • Mismatch of the relative lengths of the musculotendinous and osseous units:
    • Rapid growth +/- over-nutrition of rapidly growing animals – bone grown more quickly than the soft tissues elongate.
  • Lameness, ie pain – contraction of the muscular portion of the musculotendinous unit.
  • Treatment of flexural deformity, eg limb casting, oxytetracycline administration may → hyperextension.

Predisposing factors

  • Multifactorial.
  • Foals with the propensity for rapid growth.
  • Nutritional factors.
  • Limb casting, oxytetracycline.
  • Lameness/altered weight bearing.

Pathophysiology

  • ‘Contracted tendon’ is a misnomer as true contracture is unlikely to be the cause of most flexural limb deformities.
  • Rapid growth: during periods of rapid long bone lengthening, passive elongation of the tendons may be limited, thereby a discrepancy develops between the musculotendinous and osseous units.
  • Pain causing altered weight-bearing may also reduce passive elongation of the tendons.

Timecourse

  • Can develop in utero (congenital) and until ~18 months of age (acquired).

Diagnosis

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Treatment

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Outcomes

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Kidd J (2017) Flexural deformities Part 1: Congenital. In Pract 39 (3), 128-134 VetMedResource.
  • Kidd J (2017) Flexural deformities Part 2: Acquired. In Pract 39 (4), 182-186 VetMedResource.
  • Carlier S, Oosterlinck M, Martens A & Pille F (2016). Treatment of acquired flexural deformity of the distal interphalangeal joint in the horse: a retrospective study of 51 cases. Vlaams Diergeneeskundig Tijdschrift 85 (1), 9-14 VetMedResource.
  • Greet T (2016) Angular and flexural limb deformities in foals and yearlings. Part 2: Flexural limb deformities. Vet Nurs J 31 (7), 210-212 VetMedResource.
  • Getman L M (2011) Surgical treatment of severe, complex limb deformities in horses. Equine Vet Educ 23 (8), 386-390 VetMedResource.
  • Brommer H, Weisler S & Tatz A J (2010) Facilitated ankylosis of a juvenile, flexurally deformed, open, luxated and infected metacarpophalangeal joint using an alternative approach. Equine Vet Educ 22 (8), 412-419 VetMedResource.
  • Adams S B et al (1999) Management of flexural limb deformities in young horses. Equine Pract 21 (2), 9-15 VetMedResource.
  • Lear T L et al (1999) Autosomal trisomy in a thoroughbred colt - 65, XY + 31. Equine Vet J 31 (1), 85-88 PubMed.
  • Munroe G A & Chan C H (1996) Congenital flexural deformities of the foal. Equine Vet Educ 8 (2), 92-96 VetMedResource.
  • Jansson N (1995) Treatment of acquired flexural deformity of the metacarpophalangeal joint in foals and young horses by desmotomy of the accessory ligament of the deep digital flexor tendon. Dansk-Veterinertidsskrift 78 (14), 714-716 VetMedResource.
  • Jansson N, Sonnichsen H V (1995) Acquired flexural deformity of the distal interphalangeal joint in horses - treatment by desmotomy of the accessory ligament of the deep digital flexor tendon. A retrospective study. J Equine Vet Sci 15 (8), 353-356 VetMedResource.
  • White N A (1995) Ultrasound-guided transection of the accessory ligament of the deep digital flexor muscle (distal check ligament desmotomy) in horses. Vet Surg 24 (5), 373-378 PubMed.
  • Lokai M D (1992) Case selection for medical management of congenital flexural deformitites in foals. Equine Pract 14 (4), 23-25 VetMedResource.
  • Stick J A et al (1992) Long-term effects of desmotomy of the accessory ligament of the deep digital flexor muscle in Standardbreds - 23 cases (1979-1989). JAVMA 200 (8), 1131-1132 PubMed.
  • Whitehair K  Jet al (1992) Arhtrodesis for congenital flexural deformity of the metacarpophalangeal and metatarsophalangeal joints. Vet Surg 21 (3), 228-233 PubMed.
  • Lokai M D & Meyer R J (1985) Preliminary observations on oxytetracycline treatment of congenital flexural deformities in foals. Mod Vet Pract 66 (24), 237-239 VetMedResource.
  • Wagner P C et al (1985) Long-term results of desmotomy of the accessory ligament of the deep digital flexor tendon (distal check ligament) in horses. JAVMA 187 (12), 1351-1353 PubMed.
  • Wagner P C et al (1985) Management of acquired flexural deformity of the metacarpophalangeal joint in Equidae. JAVMA 187 (9), 915-918 PubMed.

Other sources of information

  • Auer J A (1999) Flexural Deformities. In: Equine Surgery. Eds: Auer J A & Stick J A. W B Saunders Co, USA. pp 752-765.
  • Wagner P C (1990) Flexural Deformity of the Carpus. In: Current Practice of Eqiune Surgery. Eds: White N A & Moore J N. J B Lippincott, USA. pp 480-482.
  • Wagner P C (1990) Flexural Deformity of the Metacarpophalangeal Joint (Contracture of the Superficial Digital Flexor Tendon). In: Current Practice of Eqiune Surgery. Eds: White N A & Moore J N. J B Lippincott, USA. pp 476-480.
  • Wagner P C (1990) Flexural Deformity of the Distal Interphalangeal Joint (Contracture of the Deep Digital Flexor Tendon). In: Current Practice of Eqiune Surgery. Eds: White N A & Moore J N. J B Lippincott, USA. pp 472-475.


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