ITAP

Me and my implant

In 1993 I lost my right leg above the knee in a motorbike accident. With the support of family and friends, and the dedication of numerous members of the NHS, I made a swift recovery. Within months of the accident I was sufficiently rehabilitated to return to work and in time, with a suitable prosthetic, I became a relatively high-functioning above-knee amputee.

After getting used to my prosthetic leg, I soon realised that the factor limiting my ability to wear the leg and walk any distance was the way the leg fitted. I used a rigid plastic socket that closely-fitted my stump. Once put-on each day the leg was meant to remain in place as a result of suction due to this close fit. Although this was the best type of socket for my level of activity, it would cause my stump to get sore. My weight was borne through the soft tissue of the stump and the action of walking would eventually create painful areas of skin where the socket rubbed. If I were to walk any significant distance, I would be severely restricted in what else I could then do or would have to remove my leg and let the stump recover. Obviously it was sometimes impossible to remain within my comfort zone and often I managed to make my stump sore to the point that wearing my leg was very painful. This situation was exacerbated in warm weather so I would not look forward to hot summer days with any enthusiasm. Living with this restriction became the norm and soon the changes to my daily life required to compensate for my disability became routine – the life of an amputee….

One fateful day in 2008 a letter arrived that would herald a new era in my own life and potentially that of a large proportion of amputees. I had been invited to find out more about a trial to attach my prosthetic in a novel manner, without the need for the rigid plastic socket. I rapidly expressed an interest and was subsequently informed about Intraosseous Transcutaneous Amputation Prosthesis (ITAP). If I agreed and was a suitable candidate, a titanium rod would be surgically implanted into the bone in my stump. This would protrude through the skin and allow my prosthetic to be effectively bolted to my skeleton. Use of the implant would mean there would be no need for any weight bearing by my soft tissue, removing the major drawback of a conventional prosthetic. The implant had been devised in such a fashion that the skin would hopefully heel around the protruding part, sealing the wound from infection. Rehabilitation from the operation was scheduled to take approximately six months, during which time I would be unable to wear a leg and be reliant on crutches.

It was time to make a decision. All the information I had been given sounded very positive. If all went according to plan then ITAP would be fantastic. But that was a fairly large ‘if’. Disregarding the obvious but small risks of any surgery, what if something went wrong and I couldn’t use a prosthetic at all? Despite the limitations, I did like my leg and the relative freedom it gave me. I was reassured by the fact that an ITAP implant had been performed before on an arm amputee and the results were good. But the leg implant would be significantly bigger and have to take more force. In the end, I decided to say ‘yes’ as I considered the potential benefits outweighed the risks. I just hoped that I was right!

On a Sunday in December 2008 I was admitted to the Royal National Orthoepaedic Hospital, where the surgery was to take place the following morning. With some trepidation I settled in to the ward and tried to get what rest I could. Later that evening I met the plastic surgeon who would be working on the soft tissue component of the operation, Mr Norbert Kang. I found out that I would be ITAP leg patient number two as an implant had recently been successfully performed. Somewhat reassured, I was ready for the surgery!

On Monday morning my bed and I were rolled out of the ward and over to theatre. Unusually this involved going outside as my ward (Duke of Gloucester) was separate from the main hospital building. It was a cold December morning and any vestiges of sleep were forcibly removed by the sharp drop in temperature. The covered walkway along which I was pushed was a significant improvement over the old system of having a canopy on wheels that attached to the bed to provide shelter. With friendly efficiency I was prepped for surgery and before I knew it I was waking up in recovery. After some pain relief was administerd I was wheeled back to the ward, much to relief of Helen who had been waiting somewhat nervously!

The wonders of digital photography allowed Helen to capture my delightful post-op appearance but also meant I could sneak a photo of my x-ray for posterity – the operation had gone well – I was much relieved!

As soon as I was able after surgery I had to investigate the appearance of my brand new piece of titanium. The first glance was a bit of shock as my stump looked to have trebled in size but, after being reassured it was mostly bandage, I looked further and saw a surprisingly small piece of metal sticking out from the bandage layers. It wasn’t until the bandages were removed the next day that I got a proper look. Frustratingly, everyone else’s angles for getting a look were better than mine, so I had to rely on digital photography once again.

My stump was still pretty swollen at this stage but this would subside over time. Over the next few days I was taught to look after my implant and the newly established skin-seal. After a week I was deemed fit to return home, in plenty of time for Christmas.

Fortunately for me I had Helen waiting to take care of me when I got home. I had forgotten that using crutches effectively reduces your ability to carry anything in hand to zero. This was particularly frustrating when it came to cups of tea but Helen was on hand to provide! Over the festive period I had various dressings changed on the surgical incisions and watched as the skin-seal began to heal around the protruding part of the implant. All too soon the resting phase of my recovery was over and it was back to hospital to begin physio.

Physio began with a gentle set of exercises but rapidly got tougher. Normal amputee physio aims to maintain as much muscle strength and flexibility as possible and ITAP required not only this but ‘special’ physio of it’s own. The bone in my leg had softened over my years as an amputee as it had experienced no force upon it. To ensure the implant embedded itself properly in my bone and enable me to use it effectively, it would be necessary to gradually increase the force through the bone from zero to my full weight and more, guided by the amount I could tolerate. This was achieved using a training prosthesis, which attached to the implant and could be fitted with weights.

Initially I would simply perform normal physio with the training device attached (weighing 500g). This soon became routine so I was provided with large metal cylinders that bolted on to the trainer, increasing the weight I could attach to my implant. In addition to these exercises, I was loading the implant along the axis of the bone three times a day by cyclically applying and removing an amount of weight, discerned using a bathroom scale, one hundred and eighty times in three minutes.

Cyclic loading picture…

Each week, or whenever I felt able, the cyclic loading weight was increased. I started at about 15kg and increased the amount by 5kg when appropriate. I also started wearing the prosthetic around the house and increased my wear-time as I was able. By ensuring I never pushed myself beyond the boundaries of discomfort, I was able to safely and relatively painlessly build up the amount of force that I could tolerate through the implant. This was, of course, building up to supplying me with another full prosthetic leg.

Leg picture…

In early March I was deemed ready for my new leg, which I received with great excitement. Unfortunately I had a long way to go before I could use it to walk. Initially I could bolt on the leg for further physio: cyclic loading, swinging and heel strike exercises. The heel strikes were particularly uncomfortable as these were the first jarring impacts that I had experienced through the implant. As with previous exercises though, I soon got used to movements and in a short space of time I was able to walk again in the parallel bars at the amputee gym and then on crutches. Even at this stage of my rehab I could begin to sense the potential of ITAP. I could bolt the leg on, wear it for sitting, walking, washing-up, etc, all without any soreness of my stump – it was beginning to look fantastic!

Walking again with crutches, initially for short periods.

Walking again with crutches, initially for short periods.

As my capabilities with the implant/leg combination increased I was fortunate that the skin-seal continued to behave itself and I now experienced virtually no oozing or other unpleasant phenomena. I was soon able to wear my leg for prolonged periods of time and my stability improved with more physio, including ball rolling, cycling etc.

The hardest part of the rehab was to go from crutches to walking sticks. The decreased level of support offered by sticks required a greater level of stability from my new leg than I had previously been able. With perseverance and encouragement from my physio this became routine and I rapidly progressed from two sticks to one, and eventually none!

I have had the ITAP for around eighteen months at the time of writing this text. In that time I have rediscovered the delights of walking. In essence this procedure has given me my leg back! This may sound too strong an expression of how pleased I am with the implant but it is true. Bio-mechanically, current prosthetics are very good, the limiting factor is how they attach to the person. ITAP has totally negated this disadvantage and allowed me to fully exploit the capabilities of my artificial leg. I can attach my leg on waking and only need to remove it when showering or it’s time for bed. I now feel properly balanced only when my leg is attached, the opposite of how I used to feel. I have yet to walk a sufficient distance to cause my implant to suffer, despite taking part in Kilimanjaro training, and expect only a challenge on the scale of climbing a mountain to push it to the limit. I have enjoyed hot weather for the first time since becoming an amputee and intend to make the most of this on future holidays. I have no regrets regarding my choice to take part in the ITAP trial and can only hope that the implant continues to function at this level for the foreseeable future.

My positive outcome from the ITAP trial was only achieved as a result of the hard work of numerous people. I would like to thank those who developed the ITAP and continue to support my implant, the surgeons for a good clean job and Jennifer, my physio, without whom I’m sure my rehab would have been far less effective.

As an ordinary amputee undertaking these varying adventures, I hope to demonstrate the utility of this type of implant and to increase awareness of how ingenious research and the subsequent technology can improve the lives of people with disabilities.

Follow this link for more information about another beneficiary of ITAP technology: Oscar the cat!

Pioneering Prosthetics  – A movie made by UCL about ITAP featuring Oscar and me!