ABSTRACT: A total hip replacement ITHR) is a salvage operation that is undertaken when medical management fails. The coxofemoral joint is replaced to maintain function of the limb and to provide a better quality of life for that patient As this is a complex and painful procedure, thought must be given to providing adequate analgesia both peri- and postoperatively. The VN who runs the instrument table for each THR needs an extensive knowledge of the equipment required and the order in which it is used Postoperative nursing care is paramount with every THR.

A total hip replacement (THR) is a salvage procedure performed on patients where other treatment has failed or when a delay in carrying out the procedure may be detrimental to the patient. It involves replacement of a joint that cannot be repaired and is performed when medical management can no longer maintain function of the limb or quality of life.

It is often undertaken in patients with hip dysplasia, intra-articular fractures, dislocation following trauma, or osteoarthritis (Figure 1).

Figure 1: A traumatic fracture requiring THR surgery Normal pelvis on the left demonstrates the degree of traumatic displacement

What type of implant?

There are a number of different types of THR implants on the market (Figures 2a, 2b & 2c). At Fitzpatrick Referrals we generally use BioMedtrix ‘CFX’ cemented or ‘BFX’ non-cemented implants.

Figure 2a: A cemented CFX cup and stem with a universal head

Figure 2b: An uncemented head

Figure 2c: Uncemented stem

Cemented THR implants may loosen or deteriorate with age and are, therefore, indicated in the older patient to avoid revision of the surgery. The risk of infection is greater in cemented THR as cement is more easily colonised by bacteria than metal alone (Figure 3).

Figure 3: A cemented right THR iNote obvious hip dysplasia in the left hip]

’Cementless’ THR may be performed in younger patients as they are less likely to require revising; but they are more prone to luxation, especially if they are not a perfect fit. Initially the stem impacts into the femur and the cup into the acetabulum by a ’press-fit’. Areas of bony in growth develop over six weeks- plus to provide stability (Figure 4).

Figure 4: Bilateral uncemented hip replacement

Client education

It is important that the client fully understands the procedure and aftercare required from T HR surgery. Realistic expectations vary greatly between, for instance, the inactive lapdog to the prize-winning agility dog. All the potential complications must be explained to the client.

Alternative treatments may be considered by the veterinary surgeon depending on the size, age, temperament, and clinical disability of the patient. The other surgical options are triple pelvic osteotomy, or juvenile pubic symphysiodesis in the very young patients, or femoral head and neck excision or amputation in small breeds of dog or cats.

Postoperative care, involving confinement and intensive physiotherapy to achieve the best outcome is vitally important. Clients will need to commit to the aftercare and the VN will play an important role in supporting this aspect of patient management. 

Analgesia and anaesthesia

A THR procedure is invasive and painful, so consideration must be given to the analgesia protocol before, during and after the procedure. We give methadone (10mg/ml Martindale Pharmaceuticals) as part of the premedication and peri operatively as required, and a non¬steroidal anti-inflammatory drug (NSAID) is given peri-operatively, prior to the surgery.

A fentanyl (Durogesic, Janssen-Cilag) patch can be placed before surgery but is often ineffective or less effective peri-operatively and is therefore placed during recovery.

An epidural injection of morphine (30mg/ml Martindale Pharmaceuticals) and bupivicaine (Marcain 0.25%/0.5%, AstraZeneca) is administered prior to the surgery commencing. Methadone is administered, as required, until the fentanyl patch becomes active. For most of our patients, this provides adequate analgesia.

Monitoring of anaesthesia is undertaken by one of our senior nurses who also follows the patient during the ‘post-op’ period. This can be a long procedure, taking from one to three hours to complete – so concentration and experience in anaesthetic monitoring is vital.

Radiographic views of the hips are taken prior to surgery and measurements, using a specially designed template, are taken to determine the size of the implants required for the individual. Once the patient has been correctly positioned in the theatre by the lead surgeon it is given a final sterile preparation by one of our theatre auxiliaries.

Emma Johnson, head clinical nurse at Fitzpatrick Referrals is usually required to scrub and gown’ and run the table (Figure 5). She says: “I remember the first total hip replacement I assisted with. A team of specialised nurses and surgeons from America came to share their knowledge and experience with us.

Figure 5: Emma running the THR tables during surgery

“I felt excited, yet anxious at the same time. I looked at the three theatre tables full of orthopaedic equipment and wondered how I would ever remember what each piece was and where to use it.

“The assistant is responsible for organising the tables and ensuring the equipment is within easy reach. At first, Noel Fitzpatrick would have to tell us what he required, but nowadays I, or the other trained ‘scrubbed’ assistants, have it ready to place in his hand. We have to learn the correct orthopaedic names of all the equip
ment should we work with other surgeons.

“I have been running the THR tables for over five years, but still find every procedure as exciting as my first!”

Operative procedure

The first element of surgery involves removal of the femoral head; then the acetabulum and femur are surgically adapted for the three THR component implants.

Remodelling of the acetabulum is required to ensure the acetabular cup sits securely in place. Many of the patients requiring this surgery have abnormal acetabular architecture as a consequence of chronic changes over time. A ‘starter reamer’ – comparable to a cheese grater – that is a size smaller than the final cup measurement is chosen to begin the process of remodelling. A hemisphere is formed with the reamer as it removes cartilage and sclerotic bone. A ‘finisher reamer’ then widens the acetabulum.

A ‘trial’ cup is then fitted to ensure that the entire surface of the cup is covered by the acetabulum. If a cemented cup is being used, the cement is now mixed and placed in the prepared acetabulum. The ‘CFX’ cup is then placed onto the cement, adjusted and held in place as the cement sets. The non-cemented ‘BFX’ is a press- fit cup and is positioned in the prepared area using a cup impactor’.

The femoral stem can be placed once the femoral canal has been channelled. Entry is initially made with an IM (intra- medullary) pin followed by a drill bit and then a reamer and broach to widen and deepen the canal. Once the correct size is achieved, the femoral stem can be press- fitted or cemented in place.

The third component is the femoral head which sits on the stem. The leg is then manoeuvred until the head sits securely in the acetabular cup. Once the surgeon is happy with the fit of all the components, a culture swab is taken and closure of the surgical wound begins.

When surgery is completed, the patient is transferred to the X-ray room for postoperative radiographs (Figure 6). The patient is settled into its recovery kennel which has a thick orthopaedic mattress and comfortable bedding.

Figure 6:. A postoperative lateral radiograph

The nurse recovers the patient and ensures analgesia is adequate before passing it over to the kennel nurse and ward auxiliaries. An ice pack is placed over the operation site for approximately 10 minutes and repeated every four hours.

Postoperative care

Postoperative care is paramount in THR cases. One of our chartered physiotherapists assesses each case and formulates a postoperative treatment plan, along with the senior surgeon. A nurse and one or two ward auxiliaries support the patient with the use of a sling during walks.

Secure support must be maintained at all times because if the patient were to slip this could result in luxation of the cup, head or even fracture the femur. The owners are given advice regarding the need for confinement and an exercise programme is also discussed. Physiotherapy is extremely important for these patients to ensure that they achieve the best outcome possible.


Complications of THR include luxation, infection, aseptic loosening, sciatic neuropraxia, femoral fracture, bone infarction, luxating patella and acetabular cup displacement (Figures 7 & 8).

Figure 7: A radiograph of a fractured femur

Figure 8: Fixing a fractured femur following THR

Luxation had been described as a common complication of fixed head implants’ (Richards II, Richards Medical Company, Memphis,TN) with incidences of 17 per cent during the first five years of use and three per cent during the following three years. Luxation for cemented implants ranges from one to 4.7 per cent.


Many THRs are performed in large breeds of dog weighing between 25 and 40kg, but we have also successfully completed the surgery in giant breed dogs, miniature dogs and cats (Figure 9).

Figure 9: A cat after receiving THR surgery

THR surgery results in a normal – or near normal – gait, good to normal muscle mass, and a normal range of motion. Quality of life is improved for the patient postoperatively as it aims to abolish the clinical pain felt by the patient prior to the surgery caused by the abnormally functioning joint.

The nurse plays an important role in the outcome of this extensive surgical procedure, by ensuring the patient remains calm and comfortable during the immediate post-operative recovery and its stay in hospital. 


Josephine Killner DipAVN(Surg)DipAVN(Med) RVN/MBVNA

Josey qualified as a veterinary nurse in 1988 She continued to work in primary care practice for 22 years, gaining the Advanced Diploma in Surgical Nursing (DipAVNSurg) and NVQ Assessor qualification in 2001. and the Advanced Diploma in Medical Nursing (DipAVNMed) in 2006. In 2007. she joined Fitzpatrick Referrals, as head of training.

To cite this article use either

DOI: 10.1111/j.2045.0648.00125.x or Veterinary Nursing Journal Vol 26 pp 428-431

Suggested reading

Slatter Textbook of Small Animal Surgery 3rd edition 2: 2046-2056

BRINKER. PIERMATTEI and FLO Handbook of Small Animal Orthopaedics and Fracture Repair 4th edition pp. 495-507

NELSON. L . DYCE. J and SHOTT. S [2007] Risk Factors for Ventral Luxation in Canine Total Hip Replacement Vel Surg 36[7] 644-653


Veterinarv Nursing Journal • VOL 26 • December 2011 •