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Hips :: Knees :: Shoulder :: Elbow :: Back & Spine
Foot & Ankle :: Paediatric Orthopaedics ::Sports Medicine


A detailed review of Dr. Solomon's hip and knee information is found by clicking here:


Total Hip Replacement
A comprehensive summary of Dr. Solomon's recommendation for hip replacement surgery and the type of surgery performed is shown.

Further information on hip replacements and animations are found after the summary.

Information for patients needing a Total Hip Replacement or Hip Resurfacing Replacement

Timing of Surgery

The timing of hip replacement surgery is a decision that you as the patient must make. The need for surgery is a quality of life decision and the aim of the surgery is to eliminate your hip pain. As an added bonus you will likely get a better range of motion, your limp may reduce or disappear and your quality of life should improve significantly.

If you feel that you can manage with your current pain levels then there is no urgency to have your arthritic hip replaced. Simple analgesics (eg.Panadol) or anti-inflammatories (eg.voltaren, celbrex etc) may be sufficient to provide you with a relatively painfree hip. These drugs will not improve stiffness and the arthritis will continue to progress and at some point the drugs will no longer have their pain relief affect.

Alternative medicines (eg. Glucosamine and chondroitin, fish oil etc) may have a role in helping with pain but scientific studies have proven that the claim that they “prevent arthritis or progression of the disease” is false. These medicines whilst not doing you major harm will not stop your hip continuing to wear out.

If you are overweight, weight loss may help in reducing your hip pain. Low impact exercises (walking, cycling and swimming) help maintain muscle tone and thereby control the arthritis pain.

Physiotherapy is often useful in helping strengthen surrounding muscles and maintaining good muscle tone and pelvic balance. Try to avoid overstretching the joint as this will only cause discomfort.

Things you need to know about Hip Replacements and Hip Resurfacing Replacements

Total Hip Replacement, Hip Resurfacing Replacement or “mini stem” Hip Replacement are simply different designs of prosthesis. They all replace your hip and therefore are collectively termed Hip Replacements. Some prosthesis (Birmingham Hip Resurfacing) are more bone conserving but these prosthesis still replace the acetabulum (socket) and either resurface the femoral head (ball) or replace the head but preserve more bone lower down.

What Replacement should you have ?

This can be a most complex topic particularly in discussing the options and correct choice in a young patient.

It is important to get an understanding of what’s available and in which patient group you are best placed.

The key to a successful hip replacement is the surgical skill of the surgeon implanting the prosthesis and the type of bearing used in the ball and socket joint.

Modern day hip prosthesis may well last a patient a lifetime. It is most likely that a well recognized, tried and tested implant will not wear out in patients over the age of 70 provided the surgery is performed correctly. The key to implant longevity apart from good surgical technique is the materials used in the bearing (the actual parts that move).

Facts about bearings

The traditional hip bearing is a metal head (chrome cobalt ball) that moves on a polyethelene liner (“plastic” liner). Modern day plastic liners have very low wear rates unlike the material used 30 years ago. Studies show that modern day liners will probably take about 30 years to wear out. It is for this reason that it is likely that an artificial hip joint implanted in a patient over the age of 70 will last them a lifetime. Off course should the lining wear out sooner a new plastic lining can be inserted.

In an effort to develop bearings that last longer than the traditional “plastic” lining, a number of other alternatives are available. These include the following

Ceramic on Ceramic
Metal on Metal

These bearings were developed to allow younger patients to have hip replacements as they may last longer than traditional metal on plastic bearings and hopefully last a “lifetime”

Ceramic on Ceramic

The ceramic – ceramic bearings have been around for over 20 years. They have extremely low wear rates (1000 times less than plastic) and if implanted correctly may last 40 years or more.

Unfortunately ceramics are not perfect in that there is a 1 in 20 000 incidence of breakage / fracture (ceramic is more brittle than metal) and a very rare chance that the hip can develop a squeak.

In general however ceramic on ceramic bearings are an excellent choice to use in the young patient (under the age of 65). Surgical technique is critical.

Metal on Metal Bearings

These bearings have been around for over 30 years and regained popularity with the introduction of modern designed hip resurfacing replacements.

The wear rate of metal on metal bearings is only slightly higher than ceramic on ceramic but like ceramics is significantly lower than metal on plastic bearings. Metal on metal bearings are very tough and are not susceptible to breakage (fracture).

The disadvantage of metal on metal bearings is that they produce metal ion particles and if the implant is not functioning properly these metal ions can invoke a significant inflammatory response in and around the hip joint which can cause hip pain and swelling.

Some patients are allergic to metal on metal implants but this is extremely rare. Some metal on metal bearings squeak but this is usually a temporary phenomenon.

Metal on Metal Bearings should only be used in resurfacing replacements in young very active males.


Total Hip Replacement is an extremely successful surgical procedure to improve a patient’s quality of life when arthritic hip pain becomes debilitating.
Hip replacement surgery offers patients the ability to return to their daily (and some sporting) activities without pain and with improvement in hip flexibility and movement. Patients with a significant limp as a result of an arthritic hip will often walk normally again after recovering from surgery.
The timing of surgery is a quality of life decision and it is never to late to replace the hip joint provided ones general health is satisfactory.
There are various approaches that surgeons use to replace the arthritic hip.
All recognized surgical approaches work and the most important determining factor in ensuring a successful hip replacement that should last well over 20 - 25 years is for the patient to choose a surgeon who is well skilled in hip replacement surgery.
The Australian Joint Replacement Registry and many publications show clear data confirming that more experienced surgeons have better patient outcomes.
The most important factor in determining long-term success of a hip replacement is to choose a skilled surgeon and be guided by his/her recommendations.
Every patient would like to recover as quickly as possible with as little pain as possible. Surgical and Anaesthetic techniques have improved significantly and these improved techniques have allowed an easier recovery.

The Minimally Invasive Direct Anterior Approach  (often termed DAA or AMIS) is an approach that lends itself to a quicker short-term recovery due to the fact that the surgical approach uses intermuscular planes allowing exposure of the hip joint without detaching muscle off bone. This allows a patient the ability to recover quicker and return to function quicker compared to other approaches.
There are many published articles (references at end of this article) that have confirmed that the anterior approach leads to a quicker short term recovery HOWEVER all published articles also confirm that after 12 months patients having had a successful hip replacement function equally well no matter what approach is used.
The most commonly used worldwide approach to hip surgery is the Posterior Approach (ie from the back) and published results show there is no significant difference between a well done posterior approach and well done anterior approach at 12 months after surgery. The posterior approach requires splitting the gluteus maximus (buttock) muscle and detachment of the short external rotator muscles and then reattachment of these muscles/capsule and hence the slightly slower recovery compared to the anterior approach.
There are some short-term hip movement restrictions in the posterior approach (internal rotation of the hip beyond 90 degrees of flexion) for 6-8 weeks to prevent hip dislocation whilst the capsule/muscle repair recovers. The anterior approach is inherently a very stable approach not requiring muscle repair and movement restriction. Patients usually can return to driving at an earlier stage if they have had an anterior approach.
As an experienced hip surgeon (over 20 years performing more than 3000 hip replacements) and I am very comfortable performing either the anterior or posterior approach for arthritic hip replacement surgery.
Not all patients may be suitable for the anterior approach due to many factors including:
Abnormal anatomy (such as Hip Dysplasia, Perthes, previous fractures, abnormal bone structure etc.)
Severe osteoporosis.
Significant muscular build resulting in very tight and limited joint visualization).
Significant leg length discrepancy.
Deficient bone requiring bone grafting or augmentation of the socket.
Specialised hip implants needing to replace the hip joint.
Most revision hip surgery unless a simple head/liner exchange. 
The Responsible Approach :
Every patient I see has an individual assessment taking into account their hip pathology, degree of arthritis, day to day function, general health and body habitus. I will then advise what I believe to be the best surgical approach to achieve the best clinical outcome with the least chance of complication.
Whilst I would prefer from a general recovery perspective to perform an anterior approach it is MORE IMPORTANT to ensure a safe recovery with appropriate attention to the underlying problems at hand. If I feel that the anterior approach is not suitable I will perform a posterior approach AND will reassure the patient that whilst they may have a slightly slower recovery compared to the anterior approach, their LONG TERM function will be identical.
The Final Word on approaches..........
The key to a successful hip replacement with the best chance of a good functional outcome and the least chance of complications is to choose an experienced skilled hip surgeon. Whilst the Anterior Approach may afford a quicker short-term recovery, not all patients are suitable for this approach, yet be reassured that at 6-12 months the posterior approach performs equally as well.
Hip Resurfacing:

This type of replacement is reserved for active young male patients with good quality bone ie: no osteoporosis. 


Modern day resurfacings have been around for the past 14 years. The Birmingham Hip Resurfacing Replacement (Smith & Nephew Inc: is the most successful of the Resurfacings on the market and has the longest track record (over 12 years) We have learned a great deal about resurfacings and the literature (including the Australian Joint Registry has outlined the best patients that are suited for this procedure.

Important facts to know about hip resurfacing:

Hip resurfacing patients take LONGER to recover than conventional total hip surgery patients. The reason for this is that in order to preserve the femoral head for resurfacing, more muscle and ligaments need to be released internally to allow the socket to be prepared. Patients are also advised to partial weight bear for 4 weeks post operatively to allow the bone to adapt to the new implant and not fracture. Conventional hip replacement patients are allowed to full weight bear immediately.

Hip Range of Motion in Resurfacing replacements is LESS than conventional total hip replacements using the same size ball and socket. The reason for this is that the resurfacing sits on the patient’s femoral head and neck and as such in maximal motion the femoral neck may impinge on bone preventing maximum movement compared to a ball that sits on a stemmed hip because the stemmed hip has a narrow neck allowing more impingement free motion (see drawing)

Activity Level:

A good functioning hip resurfacing is very durable and whilst it is not recommended, there have been many reports of patients running and doing triathlons with resurfacings.

ALL hip replacements, resurfacing or conventional, allow the patient to partake in sporting activities including

Backyard running with the kids

As a general rule orthopaedic surgeons do not recommend high contact sports with ANY type of replacement (resurfacing or conventional) including rugby, competition soccer, competition basketball etc)

So what’s the advantage in having a resurfacing ??

Resurfacings preserve the femoral shaft and there are reports that some patients feel that the resurfaced hip “feels more natural”

It allows the possibility of a future revision to be done without to much difficulty HOWEVER it is likely that a well done standard total hip replacement with a modern day bearing will not need revising anyhow.

The BIGGEST issue with metal on metal resurfacings is accuracy in surgical technique. This fact has only recently come to our attention as it was thought that metal on metal implants are as “forgiving” as metal on plastic implants. Recent literature has shown that the metal on metal implants (and ceramic on ceramic bearings) are very susceptible to mal-alignment and if this occurs then these implants may fail.

Cemented or Uncemented prosthesis:

There is NO difference in the revision rates of either a cemented or uncemented femoral component (the hip stem that sits on the thigh bone). A well implanted cemented stem works just as well as a well implanted uncemented stem. As outlined above the key to longevity is in the bearing and NOT whether the stem is cemented or uncemented. A surgeon will choose what stem fits best into your bone quality. In general softer osteoporotic bone with thin cortices do better when cement is used to fixate the implant.

Most acetabular components (sockets) are uncemented and the bone will grow into the component. The lining is then placed in the metal shell and this lining is either plastic, ceramic or metal. Occasionally the bone is so soft that a plastic liner is cemented onto the bone instead of using and uncemented shell..

The Final word

I hope I have enlightened you on the basic facts about hip replacement surgery. I would summarize as follows:

1. Choose a surgeon who is well experienced in Hip Replacement Surgery
2. Be guided by the information presented above as to the types of hip replacements available, bearing options and operative approaches.
3. Do not be fooled by advertising and marketing hype.

My approach and recommendations to patients requiring a hip replacement. This is a GUIDE ONLY and each patient’s individual needs are taken into account before a final implant decision is made

Patients over the age of 75 usually have an uncemented stem (if bone quality good) or cemented stem (if bone quality poor) with an uncemented socket and polyethelene (plastic) liner. A metal head is used. This hip should last a lifetime
Patients between 65-75 usually have an uncemented stem and socket with either a ceramic on ceramic liner or ceramic on polyethelene liner. This hip should last a lifetime
Males under the age of 55 who are active and have excellent bone quality are candidates for a resurfacing HOWEVER we discuss the pros and cons of resurfacing vs total hip replacement with a ceramic bearing according to the patients individual circumstances.
Females under age 65 usually have an uncemented stem and socket with a ceramic on ceramic bearing
Males between 55-75 usually have an uncemented stem and socket with the bearing appropriate for their age.
Approaches: An individual assesement is made as to what surgical approach is best for you.

Michael Solomon
(May 2014)
Additional Information on Hip and Knee Surgery
This website and the general handout I provide in the office will outline all the general principles of hip and knee replacement surgery, the  realistic outcomes and things you need to be aware of. This handout provides extra information that you may find useful. 


Before surgery you will need to attend a pre-admission clinic at the hospital where you will meet a clinical nurse who will go over the basic admission process and post operative course. In addition there are routine pre-operative blood tests and an ECG that are performed. Occasionally a chest X-ray is needed. 
If any significant abnormality is detected in your pre-operative visit, the appropriate action/referral will occur to investigate and treat any issue needing attention. 
If you see a cardiologist routinely and are on a regular blood thinner, please advise your cardiologist you are having a joint replacement and that you need to stop blood thinners such as warfarin, plavix/clopidigrol and aspirin. I am happy to perform the replacement under low dose aspirin (100mg) if your cardiologist insists. 


Please stop all anti-inflamatories (mobic, celebrex, nurofen, voltaren etc ) 1 week before surgery. 
Herbal medication (fish oils, garlic, echinacea, kava, glucosamine etc ) need to be stopped 1 week before surgery as they can cause excessive bleeding. 
If you are diabetic it is important that your diabetes is under proper control. Your GP will usually see to this. 
Dental issues. If you have any major dental issues requiring attention please get this done before your joint replacement. 
If you have any prostate issues (Males), please inform me as every patient needs a urinary catheter for 24-48 hrs and prostate problems can result in a difficult catheterisation therefore it is best to have a urologist consult if need be. 


You will be given an antiseptic soap at the pre-admission clinic that you need to shower with for the 2 days prior to surgery. This will reduce the risk of a skin infection after surgery. 
Please DO NOT shave hair around the hip or knee before surgery. The hospital nursing staff will shave the area if needed using special clippers that do not cut the skin. 


The surgery is usually carried out under a combined spinal anaesthetic and light general / sedation. Spinal anaesthesia is safe and has been shown to assist in reducing complications during joint replacement surgery. It provides excellent post operative pain relief. The Anaesthetist will discuss this with you in detail. 
A urinary catheter is used in all cases. Patients with a spinal as well as those who don't have a spinal but get morphine for pain relief, will invariably have difficulty passing urine for 12-18 hrs and hence the need for a catheter. It is much easier to pass a urinary catheter when you are sedated just before surgery than to pass a catheter when you are awake on the ward with a full bladder. 
Removing a catheter is a very easy process done by the ward nurses and is not painful at all. 
Antibiotics are given intravenously for 24-36 hrs and your IV cannula will remain in your arm for this period. The cannula is also often attached to a PCA machine which allows you to administer pain killers when needed. I do not use a PCA in all patients as often (such as in the minimally invasive hip approach) the local anaesthetic and oral pain tablets are sufficient. 
You will be given the appropriate pain relief regime that the anaesthetist will order. This regime is tailored to each individual's needs. 


The key to preventing thrombosis is mobilisation and exercise . Every patient is fitted with a calf compressor after surgery. This machine compresses the calf intermittently which promotes venous blood flow back to the heart and prevents clots. The compressors are used whilst in bed for the first 48 hrs. The sooner you get out of bed and walk the less the risk of a thrombosis. 
In addition to early mobilisation and calf compressors you will either be given oral aspirin or clexane injections to assist in reducing the incidence of thrombosis. 
I encourage 2 walks a day whilst in hospital. The more you can manage the better but don't overdo things. 
Whilst the risk of a thrombosis is low despite all preventative measures they can still occur and are treated accordingly. I do not perform a routine Doppler scan to check for thrombosis as all studies have shown that routine scanning is a waist of time. 


The risk of getting an infection in your replaced joint is extremely rare following routine procedures such as dental work and colonoscopies. 
DENTAL procedures:
For routine dental cleaning after joint replacement surgery there is no need to take antibiotic prophylaxis. For major dental work after a joint replacement ( such as root canal etc) I recommend a single dose of 2gm amoxicillin 1 hour before provided you are not allergic to amoxil. 
COLONOSCOPY, Prostate, Bladder or Gynaecological procedures after joint replacement :
Routine colonoscopy without any major biopsies or risk of bleeding do not require prophylactic antibiotic cover. 
Surgery to the bladder, bowel, gynaecological and prostate surgery require a single intravenous antibiotic dose that is administered by the surgeon at the time of the procedure. Please advise them that you have a joint replacement. 

Some other things about replacements:

All knee replacements have some numbness on the outer side of the wound. This is unavoidable as there is a skin nerve that goes directly across the skin incision and hence is purposefully cut in order to open up the knee joint. It is a minor nerve and the numbness will tend to lighten up over time but is never completely eliminated. 
All knee replacements click. This is normal. It is simply the metal and polyethylene parts touching each other and is no cause for alarm. It is how the joint functions. The clicking noise will tend to get quieter over time. 
Hip Replacements can occasionally click at the extreme of motion. No cause for alarm. Some ceramic on ceramic hip bearings can squeak (rare) again no cause for alarm. 
Intraoperative stability is important in hip replacements. Rarely one may need to tension the hip which can lead to a leg length discrepancy. Various techniques are used to minimise this possibility. 
The key to a successful recovery is motivation to mobilise and to do the exercises the physiotherapist will show you. Hip and Knee replacement surgeries have excellent outcomes provided the patients assist in a motivated recovery. 



Click on the topics below

Normal Anatomy :: Hip Arthroscopy :: Anterior Hip Replacement
Femoroacetabular Impingement :: Total Hip Replacement THR
Hip Resurfacing :: Revision Hip Replacement
Complex Hip Surgery :: Periacetabular Osteotomy :: Prevent Osteoarthritis :: Hip Fracture

Normal Anatomy of the Hip joint

How does the Hip joint work?
Find out more in this web based movie.

Hip Anatomy

Total Hip Replacement (THR)

Total Hip Replacement (THR) procedure replaces all or part of the hip joint with an artificial device (prosthesis) to eliminate pain and restore joint movement.

Find out more about Total Hip Replacement (THR) with the following links.

Total Hip Replacement Total Hip Replacement Total Hip Replacement

Anterior Hip Replacement

Direct Anterior Hip Replacement is a technique in which hip replacement surgery is performed through an alternative approach compared to conventional hip replacement surgery. Historically, hip replacement surgery was performed utilizing traditional posterior or lateral approaches. This necessitates that certain muscles or tendons are cut in order to access the hip joint and perform the surgery.

Find out more about Anterior Hip Replacement with the following links.

Anterior Hip Replacement Anterior Hip Replacement

Hip Arthroscopy

Hip Arthroscopy is a relatively new surgical technique that can be effectively employed to treat a variety of Hip conditions.

Find out more about Hip Arthroscopy with the following link

Hip Arthroscopy Hip Arthroscopy Hip Arthroscopy

Femoro Acetabular Impingement FAI

Femoroacetabular Impingement FAI is a condition resulting from abnormal pressure and friction between the ball and socket of the Hip joint resulting in pain and progressive Hip dysfunction. This when left untreated leads to the development of secondary osteoarthritis of the hip.

Femoro Acetabular Impingement FAI

Hip Resurfacing

Hip Resurfacing or bone conserving procedure replaces the acetabulum (hip socket) and resurfaces the femoral head. This means the femoral head has some or very little bone removed and replaced with the metal component. This spares the femoral canal. Find out more about Hip Resurfacing from the following options.

Find out more about Hip Resurfacing with the following links.

Hip Resurfacing Hip Resurfacing Hip Resurfacing

Revision Hip Replacement

This maybe because part or all of your previous hip replacement needs to be revised. This operation varies from very minor adjustments to massive operations replacing significant amounts of bone and hence is difficult to describe in full.

Find out more about Revision Hip Replacement with the following links.

Revision Hip Replacement Revision Hip Replacement Revision Hip Replacement

Complex Hip Surgery

Coming soon

Find out more about Complex Hip Surgery with the following links.

Complex Hip Surgery

Periacetabular Osteotomy

Periacetabular osteotomy is the surgical procedure indicated in hip dysplasia and it involves cutting the bone around the acetabulum so as to fit the head of the femur bone into acetabular socket. This method was developed and performed by Professor Reinhold Ganz and therefore it is also called as Ganz osteotomy.


Periacetabular Osteotomy is a hip preserving procedure performed to correct a congenital deficiency of the acetabulum:

Acetabular Dysplasia:

Acetabular dysplasia is a condition defined by inadequate development of an individual's acetabulum. The resulting acetabulum is shallow and "dish shaped" rather than "cup shaped". The upper portion (roof of the acetabulum is obliquely inclined outward rather than having the normal horizontal orientation.
Because of these abnormalities, the superior and usually anterior femoral head are incompletely covered by this dysplastic acetabulum.  Individuals with acetabular dysplasia usually develop through childhood and adolescence without symptoms or knowledge of their abnormality.
By the age of 30 however the patient typically experiences pain from their hip and they often seek medical evaluation and an X-ray discloses the abnormality (acetabular dysplasia).  Other patients may have been treated for hip problems as an infant or child.

Acetabular dysplasia is often also associated with abnormalities in the  shape of the upper femur which may contribute to the patient's hip symptoms.
Acetabular dysplasia is associated with an abnormally high stress on the outer edge (rim) of the acetabulum which leads to degeneration of the articular cartilage (arthritis). It is also possible for  breakdown of the acetabular labrum (rim cartilage of the acetabulum) or a  fatigue fracture of the rim of the acetabulum to occur as a result of  this rim overload. Any one or a combination of these conditions can cause hip pain sufficient for the patient to seek medical evaluation and treatment.

When the diagnosis of acetabular dysplasia is made, the X-ray also usually shows a sign of arthritis  which is most commonly an acetabular cyst though increased  bone density, a femoral head cyst, osteophytes (bone spurs), and/or  cartilage thinning may also be  present. If the dysplasia is left uncorrected worsening of the arthritis is predictable and often   progresses to a severe status within a few years and sometimes even a few months. For the patient, this means increasing hip pain, progressive loss of hip motion, and worsening
functional capabilities.
Periacetabular Osteotomy (PAO) is a surgical treatment for acetabular dysplasia that preserves and enhances the patient's own hip joint rather than replacing it with an artificial part. The goal is to alleviate the patient's pain, restore function, and maximize the functional life of their dysplastic hip.

PAO is a procedure that was developed and first performed in 1984 in Bern, Switzerland by Professor Reinhold Ganz.
The Anatomy      
Two parts comprise the hip joint: a ball on the upper end of the thigh  bone (femur), called the head of the femur, and a socket in the pelvis  known as the acetabulum. The hip joint, like other joints, is made up of specialized structural elements that serve as precisely fitting moving parts. The head of the  femur rotates freely within the  smooth, concentric surface of the  acetabulum. An extremely low  friction tissue, hyaline cartilage, lines  this joint as well as others in the human body. The friction between two hyaline cartilage surfaces is much less than the best man-made bearing.

A normal acetabulum "covers" the upper (superior) portion of the head of the femur as well as a partial portion of the front (anterior) and back (posterior) of the femoral head  "Periacetabular" means around the acetabulum. "Osteotomy" means to cut bone. Simply put, the PAO cuts the bone around the acetabulum that joins the acetabulum to the pelvis.  Once the acetabulum is detached  from the rest of the pelvis by a series of carefully controlled cuts, it is rotated to a position of ideal coverage  as dictated by the specific acetabulum's unique anatomy. PAO thereby re-orientates the acetabulum by changing its rotational position. The dysplastic roof that incompletely covers the femoral head is brought over the head to give the head a  normal coverage and also brings the roof from an oblique to a horizontal position.
Other subtle changes typically also occur. Anterior coverage may increase. Also the shortening of the  extremity and lateralization of the  joint which are often a part of acetabular dysplasia can also be  improved. Individual cases of dysplasia however present with their own unique deficiencies and the PAO must often be tailored to solve these unique problems. X-rays take during surgery confirm the correct position of the acetabulum and screws (typically 3) are inserted into the bone to maintain the acetabulum's  new corrected position during bone healing.

A proximal femoral osteotomy  (cutting and repositioning the bone of  the upper femur) is also advisable in about one out of 20 patients who  undergo PAO surgery in order to correct abnormalities related to the femur. The indication for this is not always known until during the PAO operation. The femoral osteotomy is then completed during the same surgery though a second incision is  necessary.
As with any other major hip surgery, there is some risk of complications.  Surgical wound infection and injury to major nerves or arteries is possible. Non-union (lack of healing) of the bone following the osteotomy is also possible.

Studies have shown PAO to be a relatively safe operation with the chance for any one of these complications to be less than one percent.

The Natural History of an untreated shallow hip is to develop osteoarthritis in the patients 30’s or 40’s

The periacetabular osteotomy is designed to delay the onset and progression of hip arthritis.  There is still a possibility that despite the surgery hip arthritis will continue to progress and very rarely may develop sooner if a complication arises

The Operation and Aftercare:

A cell saver is used in the operation to reduce the degree of blood loss.

An Epidural Anaesthetic as well as a General Anaesthetic is used during the surgery. The Epidural is for pain relief and is usually kept in for 3 days. A urinary catheter is placed in your bladder for 3 to 4 days. It is common for the vaginal or scrotal skin to swell for about 1 week post operatively. The swelling will always resolve. Patients spend the two hours following surgery in the recovery room where nurses closely monitor them.

The same team of medical specialists and nursing staff cares for each patient pre- and post-operatively. Included among the team's post-surgical priorities are pain management, preventing  infection,  and the prevention of deep vein  thrombosis (blood clots in large veins), and pulmonary emboli  (blood clots traveling through veins to the lungs).

Patients begin physical therapy as soon as possible to improve hip motion and muscle function and to learn to use appropriate assistive devices such as crutches or a walker.   During the first eight weeks following surgery, the operated hip should bear no more than a limited weight of 5Kg’s. Placing full weight on the operated side prior healing may lead to screw breakage and for the osteotomy to lose its position. Too vigorous exercise such as resistive exercise against weights can also cause failure. If failure occurs, re-operation may be necessary and the chance of developing arthritis is greatly increased.

The usual hospital stay is 5 to 7 days and depends on how rapidly pain subsides and progress in physical therapy. At discharge pain medication is prescribed as well as an anticoagulant to prevent blood clots. Some degree of pain after discharge is natural which may increase or decrease on different days but the general trend should be toward decreasing pain. Some patients may sense an occasional  "click" or "pop" in or around the hip. Numbness and a tingling sensation is common around the incision area. It is usual to feel numb on the outer aspect of the thigh due to bruising of a small skin nerve. This usually resolves but if not it does not cause any functional problems in the future.

After discharge if you experience severe or consistent pain or have redness, swelling and/or wound drainage please contact the hospital

Follow-up outpatient visits are necessary to monitor progress by  X-ray and physical examination. The first follow-up visit is usually scheduled about 6 weeks after surgery and the second at 12 weeks.

At 8 weeks after the surgery the patient is allowed to progress to full weight bearing and work toward discontinuing use of the crutches. Muscle strengthening exercises often with the help of a physical therapist are also started. Progress in walking depends on return of muscle strength. The majority of patients are walking without support by 3 months after the surgery Subsequent follow-up visits are at 6 months, I year and 2 years after surgery and then at 2 year intervals.  Screws are usually removed after 6 to 8 months as a small day only procedure with minimal discomfort.

Osteotomy should not be thought of as an inferior second choice to total hip replacement that the young patient with early arthritis must undergo because he or she is too young for total hip replacement. The results after PAO, which preserves the patient's own hip, justify its use and the long term results can be better than what the patient could have obtained from a hip replacement. The patient's own hip is a living tissue with self-maintenance capabilities, whereas deterioration with  time is inevitable for an artificial part. 

It is improtant to understand that a pelvic ostetomy (PAO) is not going to make your joint "normal" again. The surgery is indicated to releave pain from a dysplastic (shallow)  joint and to try and delay the progression of osteoarthritis. Osteoarthritis will always develop if one has a shallow hip. A well done PAO will delay (or possibly even prevent) the development of end stage arthritis of the shallow hip. After recovering from a PAO you should not participate in high impact running sports or competetive impact sports. You are able to walk, hike, play tennis, swim, cycle, excersise sensibly in the gym and snow ski. One always looses a little hip flexibility after a PAO.


Appropriately selected patients have an 85% chance of a successful operation and pain free hip 20 years after the surgery.

Results of periacetabular ostetomies show the majority of patients with poor results did not have an immediate poor result but were benefited by the PAO for a variable period (6-12 years) before requiring further surgery.

For patients who develop a poor result some time after their PAO surgery the cause is typically advancing hip arthritis. These patients are almost always best treated by total hip replacement surgery. For these patients the previous PAO has typically enhanced the acetabular bone with the increased femoral head coverage. Enhancement of a dysplastic acetabulum contributes to the success of a later total hip replacement by making the stability of the prosthetic acetabulum more reliable.

I trust the information provided in this handout will give you a better understanding about your hip problem and the surgical treatment available. Please do not hesitate to ask any questions.

Michael Solomon

Oct 2014

Periacetabular Osteotomy

Prevent Osteoarthritis

Coming soon

Find out more about Prevent Osteoarthritis with the following links.

Prevent Osteoarthritis

Hip Fracture

Hip fracture is a break in the upper end of the thigh bone forms the hip joint. It usually occurs in elderly people aged over 65 years either due to a fall or a direct blow to the hip. Certain medical conditions such as osteoporosis, cancer and stress injuries weaken the bone and increase the risk of hip fractures in elderly people. Often, hip fractures require surgical correction and the surgery depends on the part of the upper femur bone affected.

Find out more about Hip Fracture with the following links.

Hip Fracture

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