Distal limb conditions and injuries

• What are the conditions that affect the distal limb?

  Trauma:

  • Fractures
  • Soft tissue injuries including sprains and associated luxations.
  • Puncture wounds and lacerations (including flexor tendons)

  Infection:

  • Puncture wounds and associated cellulitus
  • Foreign bodies
  • Pododermatitis

  Miscellaneous:

  • Sesamoiditis, nail, injuries, pad injuries, corns
• Tarsal fractures and subluxations

  Multiple injuries of this type.

  The talocrural/tibiotarsal joint are commonly associated with RTAs and involve the medial and lateral malleolu and ligaments with associated subluxations and luxations.

  The tarsal bones including the central bones and T4 (seen in racing greyhound). Primary repair is possible bit poorer prognosis.

  Tarsometatarsal subluxations with associated fractures.
• Carpal fractures and subluxations

  The intercarpal and carpometacarpal are both low motion joints, so arthrodesis does little functional change.

  Damage/rupture to the collateral ligaments of the antebrachial joint are uncommon.

  Luxation of the radiocarpal bone is uncommon, associated with the rupture of the medial/radial collateral ligament.

  Intercarpal and carpometacarpal subluxations are common and associated with carpal hyper extension.
• Metatarsal, metacarpal and phalangeal fractures

  Usually a result of trauma - RTA, heavy object falling on paw, trapping/twisting the paw.

  Treatment depends on the number of bones broken.

  External caoptation with dressings or splints. Can only be employed if at least one of the metatarsal or metacarpal bones is intact to act as a splint.
• Soft tissue injuries - shear injuries

  These occur when the animal is dragged along the road with the loss of medial soft tissues and occasionally bone.

  Ligament loss results in joint instability or subluxation.

  These instabilities can be managed with the use of artificial ligament material including monofilament nylon, braided nylon and orthopaedic wire anchored around bone screws or especially designed bone anchors.
• Tendon injuries

  Small lacerations to the palmar or plantar aspect region of the paw may include flexor tendons. Often occurs between the digital and main pad.

  To determine the integrity of the flexor tendons make the dog weight bear by picking up the other limb and examine to toe position.

  Attempts to repair are rarely successful.

  
• Puncture wounds - presentation and assessment

  Present with acute lameness, soft tissue swelling to affected pad on palpation.

  Radiogrpahs may be appropriate if the presence of a radio-opaque foreign body is suspected e.g. glass.
• Puncture wounds treatment and management

  Surgical exploration with the use of a hypodermic needle may allow the retrieval of glass fragments and blackthorns.

  Flush the wound with Hartmann’s solution and leave open to drain.

  Apply dressing to protect the wound and prevent further contamination.

  The use of broad spectrum antibiotics can be justified in this situation, in a particularly deep wound.
• Cellulitis

  Develops as a result of a bite from another cat is the most common cause of lameness in this species.

  Acute onset lameness 2-3 days after fight wich may or may not have been observed by the owner.

  Swelling the limb and may be Pyrexic and off-colour. The cat will be painful with varying degrees of lameness.

  Careful palpation may reveal scabs either side of the limb where the canine teeth have punctured the skin. When you pick this scab, some pus comes out to confirm the diagnosis.
• What is pododermatitis/interdigital pyoderma?

  A dermatological condition requiring extensive work up (beware localised demodex). Patient conformation appears to be significant contributory cause of this condition.

  Is a significant cause of lameness in particular breeds including the English bulldog and the bull terrier.

  Presents with swelling, multiple discharging sinuses and hair loss.

  
• What is sesamoiditis?

  An inflammatory condition associated fragmentation of the sesamoid bones seen particularly in greyhounds.

  Can be a incidental finding of fracture 2 and 7 in the Rottweiler.

  A profound acute lameness is exhibited with pin point pain on applying pressure over the affected sesamoid and flexing and extending the metacarpo or metatarso-phalangeal joints.

  The lameness may resolve with rest only to recur with exercise.
• How do you treat sesamoiditis?

  Rest and analgesia (NSAIDs) for 3-4 weeks.

  If this fails can move on to local instillation of a depo-steroid preparation (methyl prednisolone) followed b a similar period of rest

  If this fails surgical excision of the affected sesamoid is possible but this is tricky as you have to leave the flexor tendons intact.
• Nail injuries - torn nail

  Acute onset, small amount of blood at the nail base, marked pain on manipulation of the nail.

  These will rarely heal with dressings and analgesia, so if the nail is only just hanging on then a swift pull to remove it then quickly followed by dressings and and analgesia. If the nail is more strongly adherent then general anaesthesia and removal of the nail and ungual process of P3 is indicated.
• Nail conditions - paronychia

  Bacterial infection in nail base.

  Maybe secondary to nail injury.

  Remove nail to allow drainage and then antibiotics.
• Nail conditions - Onychomycosis

  Fungal infection

  Seen in multiple nails.

  Local treatment including removal of the nails and antifungals.
• Nail conditions - autoimmune disease

  Symmetrical lupoid and onychodystrophy (SLO) seen in the GSD and greyhound.

  Pemphigus in cats and digs (cat presents with lameness and a caseous discharge from multiple nail beds).
• Symmetrical Lupoid Onychodystrophy

  A condition to manage rather than cure.

  • Remove affected nails so they are no longer prone to further trauma.
  • Nicotinamide
  • Oxytetracycline
  • Essential fatty acids.
• Neoplastic conditions of the nail bed

  Any non-healing nail bed infection or a torn nail that fails to heal after removal, always consider neoplasia.

  Radiogrpahs will show slow destruction of P3.

  Palpate the local lymph node and if enlarged aspirate.

  Treatment is amputation of the digit.

  Remember that the majority of the weight bearing is performed by digits 3 and 4 but excision of any one digit will not affect weight bearing.

  In the dog the commonest neoplasia is the squamous cell carcinoma and melanoma
• Pad laceration

  Very common in the dog, rare in the cat.

  Some can be managed with dressings only, beware of any embedded foreign bodies
• Corns

  A condition common in the gazehounds.

  Very painful, mainly in forelimbs and more common in digits III and IV, if excised they almost always recur.

  Once the weight bearing is reduced to the affected digits (by the laceration of the SDF tendon) the corn grows out and no further treatment is required.

  This can be conducted on multiple digits without loss of function.