Hip dysplasia (also known at Developmental Dysplasia of the Hip or DDH) describes the condition when the hip socket does not develop properly and is more shallow and upward sloping than normal. The severe forms are detected and treated at birth or in infancy but milder forms may not become apparent until adolescence or early adult life. The shallow socket leads to excessive forces on the front of the hip socket causing tears of the acetabular labrum and damage to the articular cartilage. Left untreated, this cartilage damage progresses to osteoarthritis, sometimes within only a few years. Early diagnosis is therefore important to improve the mechanics of the hip and relieve symptoms. The condition is much more common in females and presents with symptoms of a hip injury. Reduced walking distance and stamina develop relatively early as the muscles become more easily fatigued as they try and stabilise the hip. Instability and feelings of giving way in the hip are therefore other features of hip dysplasia.
The most effective treatment for significant and progressive symptoms is an operation to rotate the hip socket so it becomes more horizontal: peri-acetabular osteotomy or PAO. Whilst surgery to reorientate shallow hip sockets has been around since the 1960s, it was not until the late 1980s that a safe reproducible method of performing the surgery was developed by Professor Reinhold Ganz in Berne, Switzerland. It is for this reason that the PAO is also known as a Bernese osteotomy or Ganz procedure. The PAO has been further modified, with a minimally invasive method of performing the surgery being developed by Professor Kjeld Søballe from Aarhus in Denmark in 2003. Mr Bankes visited Professor Søballe in 2010 and now uses his technique. These advances have turned pelvic osteotomy from a lengthy operation requiring blood transfusion and at least ten days in hospital and three months on crutches to a procedure that takes under 90 minutes, with a hospital stay of two to four days and only six weeks on crutches. PAO is a real opportunity to improve the hip mechanics and restore young people's active lives without resort to implants and which will postpone the development of arthritis by decades. The success rate of PAO is at least 90% in relieving pain when performed before arthritis has developed, with slightly less predictable results in the presence of arthritis and in patients over 45.
Frequently asked questions
How long will it take to recover after a PAO?
Patients are in hospital two to four nights and can start to come off crutches after six weeks. They are advised to take 8 weeks off work, but clearly this varies between individuals, particularly as working from home in some capacity is possible for many. However, patients may underestimate how much the surgery affects their stamina and there is no doubt that the longer they take off work, the easier they find it on return. Patients should not do any work at all during the week of surgery and the week after so there are no distractions to recovery. Some gentle work email is reasonable from the third or fourth week, with a potential return to the office for the odd half-day from the end of week six onwards, provided the patient is driven to and from work. Return to full work is usually possible after eight weeks although it will be tiring initially. In addition, physiotherapy will be continuing and setting time aside for exercise is still required. Patients with long or challenging commutes to work should adjust their hours to avoid peak times to ensure they get a seat. By three or four months, the hip should function almost normally in day-to-day life and patients should have resumed their usual gym activities, albeit at lower intensity, with a return to running by six months. The hip will continue to improve further for up to a year after surgery. Patients sometimes report further subtle improvements even in the second year.
What tablets will I need after surgery?
Patients are given slow-release oxycodone (a synthetic morphine-type drug either Oxycontin or Targinact), ibuprofen (Nurofen, the non-steroidal anti-inflammatory drug), and paracetamol. Patients are sent home with a reducing dose of Oxycontin for seven to ten days, as well as a three-week supply of the blood-thinning tablet, Dabigatran. Patients should also have a supply of the over-the-counter painkillers Nurofen and paracetamol at home. Both these drugs can be taken together and with Oxycontin. After two or three weeks, patients are usually only taking paracetamol tablets occasionally.
When can I drive after my PAO?
If patients are confident walking without crutches and are able to enter a car unaided, then a return to driving is reasonable - usually when eight weeks have elapsed.
How much physiotherapy will I need after surgery?
Patients are advised to continue the exercises they will have learnt in hospital when they get home. It is important the hip doesn’t stiffen up whilst on crutches. Weekly land-based physiotherapy is essential for successful rehabilitation after surgery. As well as providing appropriate guidance for the hip itself, a visit to the physiotherapist provides an important focus for the week and allows the patient to see real progress at each visit. If available, hydrotherapy once or twice a week is also helpful for the first six weeks. Use of an exercise bike is strongly encouraged after coming off crutches at six weeks, initially starting with low resistance for a few minutes. Muscles take many weeks to recover not only from the surgery but also, more importantly, the long-term effect of the dysplasia itself prior to surgery. After two or three months, physiotherapy can become more spaced out as the emphasis of rehabilitation moves from the physiotherapy practice to the patient’s own gym. As the surgical discomfort subsides patients become more confident achieving goals set by their physiotherapist, with a step-wise move from static bike, to elliptical trainer and finally treadmill.
Rehabilitation Guide after PAO
Are there any stitches to remove?
No. The stitches are under the skin and dissolvable
When can I fly after my PAO?
The additional risk of blood clots after a PAO has almost gone after six weeks. It is for this reason that patients are advised not to fly long haul within this time. Shorter flights to Europe pose little, if any, additional clot risk and can be undertaken after three to four weeks provided others can carry the luggage.
What can go wrong with a PAO?
Complications are rare with modern surgical and anaesthetic techniques. Blood clot risk (deep vein thrombosis or DVT) is kept to a minimum with use of a combination of measures. The blood-thinning tablet Dabigatran is given for four weeks after surgery and the patient is advised to wear compression (TED) stockings for six weeks after surgery. In addition, foot pumps are used to enhance blood flow in the legs whilst the patient is in hospital. Wound infection occurs occasionally and whilst blood loss does occur during surgery, the advent of minimally invasive PAO has abolished the risk of blood transfusion completely. Numbness or altered sensation of the outer aspect of the thigh is almost inevitable due to the nerve which supplies skin in that area being exactly in the way. This sensory nerve is retracted and protected throughout the surgery, so usually makes a good recovery. Major nerve injury to either the femoral or sciatic nerves is rare, with a risk of less than 1%. If these major nerves are injured they have not actually been cut, but have been susceptible to stretching which occurs during the operation. Failure of the bone to heal is extremely rare and loss of fixation of the fragment would only occur if the patient is involved in a severe accident. Stress fractures of the pelvic ring can also occur usually when coming off crutches. Whilst these usually heal without incident, they do slow down recovery as the patient develops a new pain in the buttock and may need to be on crutches for a few weeks longer. Very rarely, when cutting round the hip socket, the bone cracks into the socket itself. Whilst this is usually recognised at surgery, it may prevent the socket being moved to the best position. Subtle lengthening of the leg may also occur. The most important complication is that the surgery may not succeed in its goals of relieving pain and improving activity levels. However, whilst these cases are unusual, patients do notice, as time passes, that their hip is no longer deteriorating.
Will I need my screws removing after my PAO?
Yes. We usually try to remove screws 6 - 9 months after the PAO as, at this stage, they are easy to remove; screw head breakage during removal becomes more common after about 18 months. Screw removal is a very small day-case operation re-using the top 1cm of the original PAO scar. Crutches are not required afterwards and you can go back to work the following day. As well as relieving the irritation of the screw heads when lying on your front or rubbing on trouser waist bands, screw removal also “clears the pitch” for any potential scanning or surgery. The presence of screws severely affects the image quality of any subsequent scans as well as potentially getting in the way of hip replacement components.
Will I need a hip arthroscopy after my PAO?
Possibly. About a quarter of patients need a hip arthroscopy after their PAO to deal with residual symptoms from a torn labrum. The labrum is the rubbery structure round the edge of the hip socket which becomes injured by the excessive forces that result from the shallow hip socket. The PAO takes the pressure off the labrum and in the majority of cases this is enough to provide excellent pain relief. However in some patients, the labrum still generates troublesome symptoms requiring hip arthroscopy to repair and stabilise the labrum. Hip arthroscopy is usually performed 6 - 12 months after the PAO to give time to fully assess the symptom relief by the PAO alone and is usually combined with screw removal.