Road traffic accident (RTA) is much the most common cause of feline trauma presenting to our hospital. The proportion of RTA trauma that is feline is increasing as more dogs are kept on leads.

Cats frequently suffer multiple body system trauma, and while the owner may present the cat as having a 'broken leg' you need to be alert to this. In the face of an obvious limb fracture, assess the whole cat from the outset; look after the rest of the cat and be alert to evidence of thoracic or abdominal trauma.

Common thoracic injury resulting from RTA trauma will be:

 Pneumothorax

 Lung contusion

 Ruptured diaphragm

 Haemothorax

Common abdominal trauma resulting from RTA trauma includes:

 Uroabdomen: bladder rupture; urethral trauma; ureteric trauma

 Abdominal wall rupture: ventral/paracostal

 Liver laceration/trauma

 Splenic trauma

 Biliary tract trauma

In addition to fully assessing the animal on initial clinical examination and providing supportive care as needed, including oxygen supplementation if indicated and intravenous fluid resuscitation if needed, the vet will be considering early morphine, pethidine, or buprenorphine analgesia.

Don't rush to radiography in the face of dyspnoea. Stress may tip a cat over the edge. The vet may elect to perform thoracocentesis on a suspicious thorax to confirm free air or fluid in the pleural space. Minimise stress when handling, assessing and working with a cat with respiratory compromise. Dealing with limb trauma may come secondary to assessment and support of other body systems.

Open Fractures and Degloving Injuries

A priority is to avoid hospital contamination. Wash your hands with chlorhexidine. Wear gloves or sterile gloves. Cover the open wound as soon as possible, at time of admission, to avoid contamination in kennels. It is a priority to deal with the limb further once adequately stable and under anaesthesia. Clip the whole limb (clean clippers!) while the open wound is protected with sterile, saline soaked swabs or sterile KY jelly. Treat these limbs as if they were an orthopaedic surgery going into theatre, in terms of level of care, cleanliness and working conditions. Gently use chlorhexidine to clean the surrounding skin of the limb, for the vet to assess and treat further as a surgical emergency. This may include surgical debridement, copious sterile saline lavage, and initial sterile wet-to-dry dressing and support. Often these limbs are not clipped and prepped adequately at the outset of emergency treatment.

Degloving Injuries

These need a lot of work, time and effort. Typically 5-7 days of daily sterile wet-to-dry dressing are needed until a healthy granulation tissue bed is established for free skin grafting. After grafting, the bulky dressing used to immobilise and protect the graft for the first 10 days needs to be changed every second to third day.

Fractures

 Humeral fractures: often a good candidate for intramedullary (IM) pinning. An IM pin alone is inadequate:

 Intramedullary pin and multiple cerclage

 Intramedullary pin and external fixation

 Comminuted distal humerus: intramedullary pin and external fixator.

 Radius/ulna: fairly commonly fractured. Typically plate the radius, 2.0 dynamic compression plate (DCP), or 2.0/2.7 veterinary cuttable plate (VCP). Much nursing work is involved in care, maintenance and handling in theatre of specialist equipment:

 Choice of non-sterile but shrouded battery powered drill; autoclaveable air powered drill; autoclaveable battery powered drills

 2.0 ASIF kit: drill bits and taps need delicate care

 Carpal instability: typically from a fall; a less common injury in the cat than the dog. Assess palmar stability (stressed radiographs). A temporary transarticular k-wire may be used if there is palmar stability; pancarpal arthrodesis, e.g., 1.5/2.0 pancarpal arthrodesis plate is needed if there is palmar instability. Cartilage debridement and bone grafting are central to arthrodesis. Graft is taken from the proximal humerus, or wing of ilium. Remember to clip up for the graft site while in the prep room.

 Femur:

 IM pin and multiple cerclage (N.B. be aware of potential complications of IM pinning)

 IM pin and external fixator

 Plate

 Plate-rod combination (may want very accurate caudocranial radiograph preoperatively for preoperative contouring of the plate to the lateral cortex of the uninjured leg)

 Distal femoral physeal fracture: skeletally immature cat; neutering delays physeal closure. These are very fixable fractures with cross k-wire stabilisation.

 Femoral capital physeal fracture: skeletally immature cats. Reduce and stabilise with multiple k-wires, or FHE.

 Hip luxation: if closed reduction is unstable, typically transarticular hip pinning is needed (N.B. finger per rectum intraoperatively), or FHE.

 Tibial diaphysis: often treated using an external fixator, with the limb suspended throughout surgery.

 Tibiotalar joint: this seems to be a common joint for traumatic fracture luxation in the cat. It looks catastrophic, but does well with k-wire stabilisation of any associated malleolar fracture, reduction of the luxation and transarticular external fixation. The newer generation IMEX clamps will accommodate very small, positive-profile fixator pins suitable for use in the metatarsal bones.

 Pelvis: many pelvic fractures in cats are managed conservatively. However, assess loss of intact weightbearing axis, loss of pelvic outlet diameter, pain, and neurological integrity. Many will be better managed surgically to re-establish normal pelvic canal width, and to allow earlier comfort and ambulation.

 Sacroiliac luxation

 Iliac wing fracture

 Iliac body fracture

 Sacroiliac luxation: reduction and screw stabilisation with the cat carefully positioned. There is minimal room for directional error in screw placement in the sacrum.

 Iliac fracture: typically stabilised by laterally placed 2.0 DCP or VCP.

All fracture surgery is very dependent on good equipment, veterinary surgeon and nurse understanding of equipment and its maintenance, and absolute sterility, but is very rewarding.

Postoperative fracture care involves:

 In-patient postoperative nursing, intravenous fluid therapy (IVFT), comfort, analgesia.

 Client communication: needs time spent at discharge to ensure owner's full understanding of postoperative care needs: written instructions; collapsible cage use set up prior to discharge; written instructions for safe daily care of any dressings or fixator frame; clear understanding of what is needed from home care, what problems to look out for, advice to contact hospital staff immediately if there is a concern with an implant or dressing; clear expectation of check-back appointments and scheduled follow-up radiographs through the anticipated time of fracture healing.

Ruptured Diaphragm

Careful assessment is needed to know when to move the patient from supportive/stabilising care to surgical correction. This will probably not be in the first 24 hours unless there is, for example, a dilating stomach in the thorax. The key to a successful outcome is preplanned team work and defined roles for all staff involved. Ideally the operating veterinary surgeon will have another vet anaesthetise the cat while the surgeon and scrub assistant are ready scrubbed in theatre with the instrument trolley laid out, in case the cat is unstable once anaesthetised. Clearly define the team's roles beforehand: who will do intermittent positive pressure ventilation (IPPV)? IPPV is usually best started at induction. Preplan everything before inducing anaesthesia: the area you are clipping, who is monitoring, emergency drugs pre-planned or drawn up; everybody involved there and ready. Induction is a high-risk time, and subsequent anaesthesia may be more stressful until the displaced organs are withdrawn from the thorax and returned to the abdomen. Often small intestine, omentum, spleen, liver lobe are all in the thorax. The nurses often feel happier about the cat once the veterinary surgeon has replaced the abdominal contents. Generally we don't place a chest drain after feline diaphragmatic rupture repair. Team work at the end of surgery is important, after the surgeon has gently drained the thorax of free air, and staff transition the cat from IPPV to spontaneous respiration. Take particular team care at anaesthesia recovery of these cats. There is a paper on diaphragm rupture repair listed as a reference, which we have found useful to hand out to the involved nursing/vet team before ruptured diaphragm repair.

Dog Attack

Thankfully this is fairly uncommon. The author's impression is that if there is a 'trauma cat' that does worse than expected it will be a 'dog attack cat'. Visible bite punctures are the tip of the iceberg. Tissue trauma is severe. There is potential for thoracic penetration and abdominal penetration with damage to thoracic and abdominal viscera. Be alert for the need, for example, for early, urgent exploratory laparotomy if there is suspicion of abdominal visceral damage. These animals need careful ongoing assessment and intensive care.

Fall From Height

This is an urban summer problem for the young adult cat. It usually involves an inexperienced cat under 2 years of age. Typical falls are from a first to fifth floor window sill, or balcony of a block of flats. Older cats are generally wiser. Injuries include:

 Mandibular symphysis fracture

 Hard palate fracture

 Forelimb fractures

 Hindlimb fractures

 Ruptured diaphragm

 Ruptured bladder

 Pneumothorax/lung contusions

The cat should be treated exactly as an RTA cat presentation. If you get them through this, they WILL do it again if young: advise the owners to protect cat in future by making safe any window/ balcony access.

References

1.  Sullivan M, Reid J. Management of 60 cases of diaphragmatic rupture. Journal of Small Animal Practice 1990; 31: 425-430.