July 2, 2009

1.) Hi Dr. Malhan, can you please first start out by telling us how you got started with Hip Resurfacing and give us a little background on your experience as a surgeon.  Where did you train for hip resurfacing?  Who trained you?  Did you continue your training after starting resurfacing?

Having completed my orthopaedic residency programme in the KEM Hospital, Mumbai (India), I joined the same institute as a junior consultant and lecturer. KEM Hospital is a 1800 bedded tertiary level university hospital. I had an interest in joint reconstruction surgery and was especially attracted to tissue conserving techniques. This took me abroad for further training and I completed my orthopaedic residency and FRCS (Orth) in the UK. I did my training in the west midlands rotation and had the opportunity o work with stalwarts in the field of reconstructive and hip resurfacing surgery. I returned to India after nearly seven years in the UK to join a tertiary level hospital in the city of Mumbai-Wockhardt Hospital. This is an internationally acclaimed JCI accredited hospital. Wockhardt hospital is an associate of Harward Medical, USA and offers state of the art infrastructure. I established the regional joint replacement and resurfacing centre in Wockchardt hospital Mumbai. With this, I started the journey of establishing hip resurfacing, as a bone conserving alternative to replacement in India. I started training centres, did live demonstrations to vast medical audiences and many multi centre symposia to usher in the era of bone conserving hip surgery. A number of my live surgeries were attended by various international faculties including Dr McMinn. I continue to be actively involved in resurfacing training programmers all over the world and especially in the AsiaPacific region. We recently did multiple live surgical demonstrations in various centres in Malaysia. I treat patients from all over the world including the US, Canada and Europe and have done over a 1000 resurfacings to date.    

2.)   Do you do the neck capsule preservation technique in your surgeries?

Hip resurfacing is a bone and tissue preserving surgery. All efforts have to made to protect tissues during this technique. Since the femoral head is not discarded like in a replacement one has to be certain that the blood supply to the bone in the femoral head is preserved during the procedure for good long term results.
Inspite of data to support the theory that the blood supply to the arthritic femoral head comes predominantly by an intraosseous route (i.e. bloodvessels that lie inside the bone) and hence cannot be damaged by soft tissue dissection on the outside, recent anatomic studies reveal that the intraosseous route may certainly not be the only source of blood and definitely not in all patients. The retinacular blood vessels (these blood vessels run along the outer side of bone in the femoral neck) appear to make an important contribution to blood supply of the femoral head , especially in cases where the progress from a normal to an arthritic hip has been swift and the intraosseous supply has therefore not had adequate time to develop. It may be therefore assumed that in cases where the progress of arthritis has been slow and over a number of years the intraosseous blood supply has had time to adapt to the change in bone architecture and is sufficient for viability of the femoral head provided gross tissue and vascular damage s not done. This is often the scenario in cases with osteoarthritis. However in hip conditions where the progress has been sudden, the intraosseous blood vessel may be insufficient to keep the femoral head viable after the procedure.
Various surgeons have used different techniques to preserve these retinacular extraosseous blood vessels (blood vessels outside the bone). Some have advocated a routine capsular ( capsule is the layer of tissue that encloses the hip joint just as your car cover would enclose the car) opening but care in dissection around the femoral neck. Others have suggested to open the capsule in a circumferential manner so as to leave a skirt of capsule around the femoral neck in the hope that this will form a soft tissue barrier preventing damage to the retinacular blood vessels that lie deeper to it. This has been often described as the neck capsule preserving approach.
It is important to remember and not lose sight of the fact that it is the blood supply and vascularity we are interested in and preserving the capsule is merely a means to an end. Preservation of capsule but disrespect to blood supply will lead to a poor result. It is for exactly this reason that I have developed the biologic “vascularity preserving approach” (VPA) for hip resurfacing surgery at our centre. As part of this technique the capsule  is routinely preserved in a manner that retinacular blood vessels have minimum chance of damage and it is easy to close the capsule anatomically after the procedure. This closure has been shown to increase the hip stability manifold and probably also preserves proprioception better. Besides this, attention is given to doing all tissue dissection well away from bone so that we may preserve as much blood supply to bone as possible. The  quadratus muscle is braided into tight bundles using a special technique we have designed and then cut well away from area of insertion so that the main feeder vessels that run alongside are also preserved. We release the gluteus maximus tendon only when it appears to restrict exposure.       

3.)  Do you re-attach the gluteus tendon?

The gluteus medius and minimus is never released and the gluteus maximus tendon is only released when needed. This has two advantages –
a) It reduces the size of the incision needed
b) It preserves soft tissue
In cases where anterior translation of the femur is tight ,  release of the gluteus maximus tendon is done with stay sutures in place. This is always stitched back at end of procedure.

4.)  Which approach do you prefer to use antero lateral or posterior?

Before we decide which hip exposure for resurfacing is the most appropriate let us understand the special requirements for this surgery in terms of surgical approach.
Resurfacing is a surgery done for active individuals who look forward to a very active lifestyle. The surgical approach has to allow satisfactory exposure to perform a good job on the bone and at the same time cause less tissue damage so as to allow a fast rehab and satisfactory postoperative result.
One must appreciate a very subtle but significant difference between resurfacing and replacement i.e. in a resurfacing the head and acetabular size must match. If one uses a larger head to avoid notching the neck then you are committed to a larger cup size which causes greater bone loss on the acetabular side. A smaller head will preserve acetabular bone but is technically more demanding to avoid notching. To make resurfacing truly bone conserving, it is not enough to simply preserve bone on the femoral side. The acetabular bone stock has to be respected and preserved by using an appropriate size of femoral head. All this means a satisfactory surgical exposure without any struggle or lack of visualization during surgery. The chromium cobalt metal cups in a resurfacing are harder than the titanium joint replacement cups. The bone has to be prepared adequately to allow satisfactory fixation and at the same time avoid fracture of bone while inserting these hard cups. Cup deformation is also not acceptable. All this demands a generous view of the acetabulum.
I do not think a direct anterior approach is satisfactory for a resurfacing for the same reasons.
I strongly believe that the posterior exposure of the hip allows satisfactory bone work with ease and through a smaller incision. It is a more anatomical approach and releases only those structures which were tight anyway due to the inherent external rotation deformity most of these patients have. Releasing tight external rotating muscles is probably helpful in deformity correction. Also this approach does not damage the gluteus medius muscle which I think is the workhorse muscle and most important for good post operative function. The anterolateral approach damages the gluteus medius muscle. The posterior approach is my preferred exposure for a hip resurfacing.     

5.)  What size do your incisions normally range in inches?

I believe in mini invasive surgery. My average incision  ranges between 4 – 6 inches. It will be longer for more obese patients, tighter hips, revisions and complicated cases. The smaller the incision the better but it must not make the surgery maxi invasive due to excessive tissue retraction by assistants and should not jeopardize the tissue conserving nature of this operation, as I mentioned earlier. It is important to understand that mini invasive can also be mini incision but mini incision is not necessarily mini invasive.

6.)   How long do you feel it takes for the bone to be fully healed, actually grow into the prosthesis?

There is evidence to show that the bone starts to grip on to the uncemented prosthesis as early as 3 weeks after implantation. This is supplemented by a good primary fit at time of operation and the implant is usually quite stable to allow early full load bearing mobilization. However if we look at it like healing of a fracture which usually takes about 3 months, one can safely assume that osseointegration of the implant will take the same amount of time.

8.)   Barring any complications, how many days in the hospital will a patient normally stay? Can you explain how you handle overseas patients.

The patient is discharged from hospital once the wound has settled, the patient is comfortable and pain free, and independently mobile with aids. In our practice Indian local patients are discharged at 3-4 days after operation. Overseas patients who have to take long flights back home also mobilize as fast as the local patients but are discharged 9 days after operation in view of the long journey home. This also allows extended supervised physiotherapy and the patients are quite clear about future rehab protocols and expectations by the time they are ready to fly back.

8.)   What is your typical rehab protocol?  90 degree restriction? Walker” Crutches Cane? amount of time?  Blood thinners?  TED stockings?  Ice?  PT

The rehab protocol is divided into various phases depending on what is most important for the patient at a particular time after surgery.
Phase 1: designed to make the patient independent, allow wound healing, and make the patient comfortable – first 3-4 days
Phase 2: geared towards improving range of movement along with gentle muscle strengthening. Build up on gait training and functional activities – 3 days May go on longer in pts who have severe problems
Phase 3:  From now on muscle strengthening and gait gradually become more aggressive depending on what the patient can cope with.
The patient is allowed to sit up comfortably on the first post operative day. How much to bend is decided by the patient based on the tightness he or she feels in the buttock. The satisfactory capsular closure at time of surgery allows safe hip bending and tells the patient what is appropriate for him or her. I think it is extremely important that the surgeon should not over tighten the hip due to the way in which he implants the prosthesis or closes the tissues to allow comfortable and satisfactory rehabilitation.
The various phases of mobilization after surgery may overlap and their durations may vary from case to case.
Overall plan is to have the patient completely independent, comfortable and safe for a long haul flight within about 9 days after operation. It is for this reason that I insist on the patient staying in hospital for the full nine days after operation, to undergo physiotherapy under my care. I do not prefer them being moved to a hotel a few days after the surgery.
We give our patients detailed advise on rehabilitation on return to home country. There are hotline numbers for contacting the hospital and doctor if needed.
We use a combination of mechanical and chemical prophylaxis for DVT. Compression Stockings are also used but we like make sure the stockings do not curl down and cause a tight band around the leg.
Local patients are discharged from the hospital 3-4 days after the operation, when phase 1 is complete. This followed up by a home physiotherapy programme.
9.)   How long before a typical patient is allowed to drive a car, return to work?
I advise against impact loading work for 6 months.
Return to work depends on the kind of work, need for traveling and need for use o public transport. The patient may return to work as early after surgery if appropriate on the other hand I have had patients who do very heavy work and climb ladders where I have recommended a longer period off work The average is about 4 – 6 weeks after surgery.

Car driving can start once the patient has a good leg control and strength. It should alo fulfill insurance requirements in the country in question. I generally recommend about 4 - 6 weeks after surgery.

10.)   What is the recommended time you tell your patients before they can start to run again/do impact sports?  Are there any sports you don’t want your patients to participate in after surgery?  Out of the patients you have resurfaced what are some of the sports they have returned to?

I recommend starting impact sports only 6 months after surgery and a good rehabilitation programme. I do not forbid them from returning to what they were doing before operation. A good resurfacing should mimic the native hip joint without significant collateral damage. It should not significantly damage and alter the integrity of the soft tissues. I see no reason why the individual cannot return to what he was doing easily before the operation. The operation should make him safer and better at doing the same activity . We have simply changed the joint surface. I have had my patients return to activities like athletics, cycling, swimming and diving, karate, rock climbing, gymnastics, dancing, weight lifting, horse riding, tennis, football, etc

11.)   What is your take on cementless (femoral) devices for resurfacing?

Cementless femoral resurfacing devices have been tried in the past without success. A lot has changed since then in terms of preserving blood supply to the head and the quality of surface coatings. But cemented femoral components have given good results and would be keen to stick to them.

12.)         Do you have a cut off age for resurfacing patients or do you go on a case by case basis?

I do not give much importance to the chronological age of the patient. If the patients physiological age is young, functional demands high and the life expectancy appropriate to justify a tissue conserving operation along with a hip anatomy and pathology where resurfacing is likely to give a better long term result than replacement, then I would offer a resurfacing. Choice of procedure is made on a case to case basis. I have done successful resurfacing on patients as young as 18 yrs and as old as 84 yrs.

13.)         What type of anesthesia do you use general or epidural or ?

I usually leave the type of anaesthetic to my anaesthetist and patient preference. However I prefer to have an epidural catheter in all my patients for good post operative pain control.

14.)     Are there any cases that you will not take in particular, AVN, dysplasia, small cysts.  Maybe touch on some of the very difficult cases you have been able to resurface.

The decision to offer and do resurfacing in a particular case depends depends upon a host of factors. These can be divided into general factors like age, activity level, bone condition and other medical conditions and local hip factors which determine whether a particular case is appropriate for a resurfacing. The main advantage of a resurfacing is bone conservation and the value of this for a particular patient has to be understood in the light of the functional status, age and life expectancy. Obviously a younger patient will benefit more from such a technique and hence I would push the limits of the procedure if I am reasonably certain that I can a satisfactory stable construct can be achieved while conserving bone on the acetabular and femoral side.
The most important thing to realize when doing a resurfacing is that it is a procedure where femoral head and acetabular cup size must be matched. With increasing head size the cup size will increase and therefore sacrifice more acetabular bone. This is probably the most important distinction between a resurfacing and a replacement where acetabular cup sizing is independent of the size of femoral head.
Everybody talks about preserving femoral bone, but it is as important to preserve bone on the acetabular side to make the surgery truly bone conserving. A resurfacing done inappropriately without acetabular and femoral bone preservation will not do justice to the procedure. Therefore when I decide on this procedure I am certain with my templating that I can implant appropriate sizes. If there is something in the anatomy that prevents me from doing this  then I would not offer a resurfacing
Besides this it is also essential to produce a stable construct which is biomechanically sound. The implants have to be in satisfactory alignment with an appropriate degree of head valgus, and good bone contact. Cementing a femoral head in a position which is satisfactory but has poor bone contact is not going to justify the operation. At the same time the acetabular anatomy has to allow a cup which is appropriate in size and position with good bone coverage and contact. As in all metal on metal bearing the cup has to give satisfactory cover over the femoral head.
The hip chosen for a resurfacing must be in a patient where it is going to justify the bone conservation and at the same time do justice to the bony anatomy and offer a stable long lasting solution to the problem.
I specialize in hip and knee reconstructive surgery. I established a large regional joint resurfacing and replacement centre and hence see a large number of complex cases. I see a number of patients where I feel that the patient profile and functional level would benefit most from a bone conserving procedure like resurfacing. Often the hip anatomy and pathology in these patients is less than optimum for the procedure and a significant percentage of the 1100 plus resurfacings we have done to date demanded specialized techniques and novel ideas to achieve what we set out to do. I have developed principles of a technique – capitoplasty, which allows one to deal with the most complex of cases. It looks at how one can use the femoral head bone in the most optimum way with correct sizing and positioning of the implant. It allows you to sacrifice areas with unhealthy bone and preserve what is healthy. I have described the “principle of thirds” which allows easy and accurate decision making when confronted with femoral head defects and cysts. I have often elaborated on the choice of implant appropriate to hip pathology. Since I think this medium is not appropriate for taking commercial names I will refrain for specifically naming products. Available implants vary greatly in terms of their thickness, cementing technique, cup surface and fixation devices and must be chosen as per requirements of the case. Obviously implant history and metallurgy must be definitely considered. My vascularity preserving technique helps in these cases especially those of avascular necrosis of the femoral head which forms the bulk of our Indian patients. I have often spoken at meetings about the pros and cons of various instrumentation systems for resurfacing i.e. use of the lateral referencing jigs or direct head neck referencing systems based on the condition of the hip.