Total Hip Replacement
A total hip replacement is a surgical procedure to repair the hip-joint by partly (Hemi-arthroplasty) or fully (Bipolar-hemiarthroplasty) replacing the original hip joint with prosthetic substitutes. Care needs to be taken with this operation because of the invasive nature of this procedure , it is cautiously deliberated if surgery is advised, to take account of age, medical problems, hip disease, activity status and possible fracture characteristics.
Clinically Relevant Anatomy
The hip a ‘ball and socket’ joint. This means that the caput of the femur fits in the acetabulum of the pelvis. The ‘ball’ is the femeral head which fits into the socket is the acetabulum of the pelvis. This ball and socket design is what allows the poly-axial movement seen at the hip. The hip is made up of the pelvis and the femur. The pelvis is formed by 3 bones; the ischium, ilium and pubis. The femur is the longest and strongest bone in the human body. The acetabulum is cup-shaped providing the articular surface for the head of femur to move within. The head of the femur is gripped by the acetabulum beyond its maximum diameter. The caput of the femur and the inside of the acetabulum are covered with a layer of hyaline cartilage.
Total hip replacement is a frequently done procedure.  Hip replacements are used to repair hip fractures, caused by trauma’s such as a fall. Osteoporosis and osteomalacia are significant factors responsible for the high incidence of hip fractures within the elderly population. Arthritis is a common degenerative process occurring in joints within this eldery population, with osteoarthritis being the most common of the varieties. Due to the high degree of success at reinstating independence and mobility of osteoarthritis sufferers, total hip replacement procedures have become a well accepted treatment modality for hip degeneration secondary to osteoarthritis. It is also a treatment for (juvenile) rheumatoid arthritis but only if all the other options have failed.
Often unable to walk, complains of vague pain in the knee, thigh, groin, back or buttock and difficulty of weight bearing 
Crepitations are sensible or audible when the hip is moved, inability to assume the neutral anatomical position.
Range of all hip movements is impaired, movement is painful, pain and stiffness when the activity is resumed after resting. 
Because patients with a hip replacement have muscular atrophy and loss of muscle strength, particularly in the gluteus medius muscle and ipsilateral quadriceps, it may be good to consult a physiotherapist after surgery. The result of the loss of strength is that the elderly are less independent. Early postoperative rehabilitation after total hip replacement focuses on resorting mobility, strength, flexibility and reducing pain.  Patients with total hip replacement often present with a gradual decline in hip muscle strength two to three years after the operation.  Research has also shown that when the hip abductors are weak after surgery there is a major risk associated with joint instability and prosthetic loosening. A gait dysfunction may persist for many months after joint replacement. 
Indications for surgery
Pain and loss of mobility are the most common preoperative complaints of patients with a total hip arthroplasty. Preexisting hip disease is a valid indication for primary total hip replacement. When there are complications with the internal fixation of a fracture to the femoral neck, in particularly if articular cartilage in the acetabulum is lost or when endoprosthesis have failed in acute fractures, a total hip replacement is a good solution.
Fractures of the neck of the femur caused by an underlying pathology for example Paget’s disease in older patients are generally treated with a total hip replacement. When a patient is suffering from a rapidly destructive hip disease ,a rapid destruction of the femoral head or the pubic ramus is observed on the radiographs, therefore a total hip replacement should be the only option.
Important considerations before choosing for a total hip arthroplasty are age, activity status, the patients expectations and medical conditions based on radiological disorders.  Medics are cautious with performing a total hip replacement. It’s only used when all other options failed. In the end it’s the surgeon who decides if a total hip replacement is the best solution for the patient.
There is no specific way to diagnose if a patient is in need of a total hip replacement. Mainly because there are multiple possible disorders where a total hip replacement is recommended. When a patient is complaining about hip pain this is notoriously misleading, for often it is referred from the spine or pelvis and so it has no connection to the hip joint itself.There are ways to see if the patient has the conditions in which a total hip replacement can be required for example an MRI and a physical examination. It will be the decision of the treating doctor to do a hip replacement.
The task of a physical therapist consists before the operation of investigating the muscular state (force, volume), ROM and the circulatory state of the injured as well as the healthy limb  . This gives an idea of the preoperative state of the patient.
The general physical and psychological state of the patient should also be taken care of.
For example explaining the surgical technique and the therapeutic monitoring after surgery can help lowering the patient’s anxiety. Explaining how to use a rollator or walk on crutches properly can also make the patient more self-confident when entering the postoperative stage of the therapy.
Many surgical approaches for THR are described but we can resume them to anterior, lateral and posterior approach. These approaches determine the amount of soft tissue damaged. Many surgeons are changing from a posterior approach to a more anterior one. Cadaveric studies show that this type of approach is less invasive and damaging for muscles, capsules, ligaments and nerves. Other studies have shown a better rehabilitation time and functional outcome. Because of the lowered risk of dislocation compared to a posterior approach, early mobilizations as well as full weight bearing exercises according to tolerance are made possible in the first postoperative days.
The articulating couples (head and cup) used by surgeons are made of metal-on-polyethylene (PE), ceramic-on-PE, metal-on-metal and ceramic-on-ceramic. Important components of prosthesis are friction-coefficient, survival, stability against dislocation and fixation in bone tissue. In some cases there can be formation of osteonecrosis due to erosion of the two components rubbing against each other.
Physical Therapy Management
The main factors defining the therapy management are the surgical approach and the general state of the patient. Whether the patient desires to gain physical fitness or wishes to recover for recreational activity should also be taken into account when establishing the rehabilitation program.
After a total hip replacement there are a set of essential and mandatory precautions patients should be taught and adhere to prevent dislocation. These precautions are hip flexion above 90 degrees, endorotation and adduction across midline. For example, cycling with elevated saddle and low resistance keeps the articulation in a reasonable range of motion and induces bearable joint load. For the anterior approach it is the combination of extension, exorotation and abduction although the probability of dislocation is less great than for the posterior approach.
The risk of dislocation after replacement is great because of the trauma to the stabilisers of the hip such as the capsule, ligaments and muscles but also due to the size difference of the prosthesis to the bones. The average diameter of the head of femur in a human is 46mm and the prosthetic head of femur can range between 32mm-38mm and therefore this reduced size makes it easier to dislocate until the stabilising tissues have healed and adapted to this smaller size. This generally takes up to 6 weeks to occur.
The treatment after a total hip arthroplasty (without other complications) includes the non-exhaustive set of items listed below. The given order is not fixed but shows a progressive contribution of the patient in the therapy. It should start as soon as possible according to the patient’s tolerance and medical recommendations.
- First postoperative day:
• Static contraction of the M. Quadriceps in order to have a muscular and circulatory effect.
• Flexion/extension/rotation of feet and toes to prevent edema
• Education of muscular relaxation
• Upper limb exercises to stimulate the cardiac function
• Maintenance of the non-operated leg: attention should be paid to the range of motion in order to preserve controlled mobilization on the operated hip.
Bed exercise following total hip replacement does not seem to have an effect on the quality of life but remains none of the less important (edema, cardiac function, etc.). It also allows an assessment of the physical and psychological condition of the patient right after surgery.
- First postoperative week:
• Active/passive mobilizations to gain ROM
• Progressive resistance exercises
• Progressive weight bearing exercises according to tolerance
• Equilibrium exercises including walking with crutches/2 canes/1 cane.
Early exercises including full weight bearing exercises have shown different positive effects on the recovery of patients after THA (faster recovery, gain in walking ability). Physical activity is also good for quality of bone tissue. It improves the fixation of the prosthesis and decreases the incidence of early loosening. Once again the amount of activity is linked to the general state of the patient. Certain specific sport movements have a higher risk of injury for unskilled individuals.
- 1-12 postoperative month:
• Gain of initial ROM, muscular force (stabilization), and control (proprioception).
• Equilibrium on one foot
• Speed, precision, neurological coordination
• Functional exercises
Physical therapy quickly maximizes the patient’s function which is associated with a greater probability of earlier discharge, which is in turn associated with a lower total cost of care.
Minns Lowe C. J. et al. Effectiveness of physiotherapy exercise following hip arthroplasty for osteoarthritis: a systematic review of clinical trials. BMC Musculoskeletal Disorders 2009; 10 (98)
Clinical Bottom Line
Proper preoperative examination and early postoperative rehabilitation is crucial for succsessful outcome.
Keywords: total hip replacement, total hip arthroplasty, surgical approach for THR, rehabilitation/physiotherapy + THR.
Recent Related Research (from Pubmed)
- ↑ 1.0 1.1 1.2 1.3 1.4 GREMEAUX, V., RENAULT, J., PARDON, L., DELEY, G., LEPERS, R., CASILLAS, J., Low frequency electric muscle stimulation combined with physical therapy after total hip arthroplasty for hip osteoarthritis in elderly patients: a randomized controlled trial, http://www.archives-pmr.org/article/S0003-9993%2808%2901388-9/fulltext (accessed: 2010-12-25)
- ↑ 2.0 2.1 2.2 2.3 2.4 JAN, M., HUNG, J., LIN, J.C., WANG, S., LIU, T. TANG, P., Effects of a home program on strength, walking speed, and function after total hip replacement, http://www.archives-pmr.org/article/S0003-9993%2804%2900306-5/fulltext ( accessed: 2010-12-25)
- ↑ 3.0 3.1 3.2 3.3 STOCKTON, K.A., MENGERSEN, K.A., Effects of multiple physiotherapy sessions on functional outcomes in the initial postoperative period after primary total hip replacement: a randomized controlled trial, http://www.archives-pmr.org/article/S0003-9993%2809%2900377-3/fulltext (accessed: 2010-12-25)
- ↑ 4.0 4.1 4.2 4.3 RAHMANN, A.E, BRAUER, S.G., NITZ, J.C., A specific inpatient aquatic physiotherapy program improves strength after total hip or knee replacement surgery: a randomized controlled trial, http://www.archives-pmr.org/article/S0003-9993%2809%2900144-0/fulltext ( accessed: 2010-12-25)
- ↑ MEYERS, H. M., Fractures of the hip, Chicago: Year of the book medical publishers Inc.,1985
- ↑ 6.0 6.1 TRUDELLE-JACKSON, E., SMITH, S.S., Effects of a late-phase exercise program after total hip arthroplasty: a randomized controlled trial http://www.archives-pmr.org/article/S0003-9993%2804%2900156-X/fulltext (accessed 2010-12-25)
- ↑ CALLAGHAN, J.J., ROSENBERG, A.G., RUBASH, H.E., The adult hip, second edition, Philadephia: Lippincott Williams &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp; Wilkins, 2007
- ↑ 8.0 8.1 8.2 8.3 8.4 MEYERS, H. M., Fractures of the hip. Chicago: Year of the book medical publishers Inc., 1985
- ↑ 9.0 9.1 9.2 9.3 9.4 9.5 CRAWFORD, A.J., HAMBLEN, D.L., Outline of Orthopaedics , thirteenth edition,Londen: Churchill Livingstone,2001
- ↑ BATRA, S., BATRA, M., McMURTRIE, A., SINHA. A.K, Rapidly destructive osteoarthritis of the hip joint: a case series, http://www.josr-online.com/content/3/1/3 ( accessed: 2010-12-25)
- ↑ 11.0 11.1 BRUNNER, L.C., ESHILIAN-OATES, L., KUO, T.Y., Hip fractures in adults, http://www.aafp.org/afp/2003/0201/p537.html (last checked: 2010-12-25)
- ↑ KINGMA, M.J., KOEKENBERG, L.J.L., VAN LINGE, B., VAN RENS, TH.J.G., SIJBRANDIJ, S., Letsels van het steun en bewegingsapparaat, Utrecht/Antwerpen: Scheltema &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp; Holkema BV,1983
- ↑ 13.0 13.1 13.2 Raymond Sohier, Kinesitherapie de la hanche ; La Hestre : Sohier, 1974
- ↑ Van Oldenrijk J. et al., Soft tissue damage after minimally invasive THA. Acta orthopaedica 2010; 81 (6): 696-702
- ↑ Zhang X. et al. Anterolateral muscle sparing approach total hip arthroplasty: an anatomic and clinical study. Chinese Medecine Journal 2008; 121 (15):1358-1363
- ↑ 16.0 16.1 Röttinger H. Minimally invasise anterolateral approach for total hip replacement.,Operative Orthopädie und Traumatologie (4)
- ↑ Sköldenberg O. et al. Reduced dislocation rate after hip arthroplasty for femoral neck fractures when changing posterolateral to anterolateral approach. Acta Orthopaedica 2010; 81 (5): 583-587
- ↑ http://orthopedics.about.com/od/hipkneereplacement/a/implants.htm
- ↑ Bader R. et al. Differences between the wear couples metal-on-polyethylene and ceramic-on-ceramic in the stability of dislocation of total hip replacement. Journal of materials science: materials in medicine 2004; 15:711-718
- ↑ Garcia-Rey E. et al. Alumina-on-alumina total hip arthroplasty in young patients. Clinical Orthopaedics and Related Research; 467 (9):2281-2289
- ↑ 21.0 21.1 Mahendra G. et al. Necrotic and inflammatory changes in metal-on-metal resurfacing hip arthroplasties. Acta Orthopaedica 2009; 80 (6): 653-659.
- ↑ Kuster M. Exercise recommendations after total joint replacement. Sports medecine 2002 ;32(7) : 433-445
- ↑ Mirza S, Dunlop D G, Panesar S, Syed G N, Shafat G, Saif S. Basic Science Considerations in Primary Total Hip Replacement Arthroplasty. The Open Orthopaedics Journa. 2010;4,169-180
- ↑ Suetta C. et al. Training-induced changes in muscle CSA, muscle strength, EMG, and rate of force development in elderly subjects after long-term unilateral disuse 2004; 97: 1954-1961
- ↑ Smith T. et al. Bed exercises following total hip replacement : a randomised controlled trial. Physiotherapy 2008; 94: 286-291
- ↑ Perhonen M. et al. Cardiac atrophy after bed rest and spaceflight. Journal of Applied Physiology 2001; 91: 645-653
- ↑ Ström H. et al. Unrestricted weight bearing and intensive physiotherapy after uncemented total hip arthroplasty. Scandinavian Journal of Surgery 2006; 95: 55-60
- ↑ Kishida Y. et al. Full weight-bearing after cementless total hip arthroplasty. International Orthopaedics 2001; 25: 25-28
- ↑ Freburger J. An analysis of the relationship between the utilization of physical therapy services and outcomes of care for patients after total hip arthroplasty. Physical therapy 2000; 80 (5): 448-458