Ronnie Furlong, the man, his hip, his philosophy, the manufacturing breakthrough…

Alister Hart

Alister Hart is a hip surgeon at the Royal National Orthopaedic Hospital NHS Trust and the UCL chair of orthopaedics. The BBC nicknamed him the ‘Hospital Hip Detective’ for his clinical and research work on hip implants which has led to changes to international health policy and regulation. He has pioneered the use of 3D printing for primary and revision hip surgery.

It is 50 years since the founding of the UK hip implant manufacturer, JRI Ltd, by Ronnie Furlong. Actually it is now 51 years, because this anniversary was overlooked in 2020 because of COVID-19. I met him, and his wife Eileen, whilst working on the surgical training rotation at St Thomas’ Hospital in 1998. He was an inquisitive doer, entrepreneur, and leader who was at the epicentre of British orthopaedics at a crucial time.

1970 is arguably the key year for hip implant innovation in the UK: the year the Exeter stem was invented; the year that Bill Harris started the renowned Harvard hip course to disseminate the use of the Charnley hip replacement throughout the USA; and the year that Ronnie Furlong set up JRI Ltd to import the Muller ‘Banana’ hip from Germany to the UK.

Key dates in Ronnie Furlong’s life (1909 – 2002)

• 1969 – Director of the Orthopaedic Department at St Thomas’ Hospital.

• 1970 – Established JRI Ltd to enable import of the Muller stem from Germany.

• 1976 – JRI manufacturing plant in Sheffield.

• 1979 – Clinical use of new cemented Furlong straight stem: based on the conical stopper of a wine decanter.

• 1985 – The first hydroxyapatite ceramic coated (HAC) prosthesis, the cementless Furlong straight stem, was implanted by Ronnie Furlong.

Ronnie Furlong.

The war

Ronnie Furlong joined the army during the war and in his five years of service he commanded orthopaedic units in North Africa, Egypt and Italy. This active war experience was invaluable to his orthopaedic career. In Caserta, Italy, he plated and documented 200 fractured femora and then in Germany he observed Kuntschner himself using his nail.

St Thomas’ Hospital

In 1969 he became Director of the Orthopaedic Department at St Thomas’ Hospital, where one of his responsibilities was the teaching of hip replacement surgery. He was neither keen on Charnley’s small 22.25mm head and the surgical technique of removal and rewiring of the greater trochanter, nor on Mckee’s hip. He met Professor Maurice Muller of Switzerland, and learnt his operative technique of the Muller curved stem with a 32mm diameter head, which he named the Muller ‘banana’.

Joint Replacement Instrumentation (JRI) Ltd

He was so impressed with Muller’s Banana hip that in 1970, in order to obtain an import licence for the Muller hip, he established Joint Replacement Instrumentation (JRI) Ltd. In 1976, in order to encompass his growing interest in the design and manufacture of prostheses and instrumentation, he expanded the Company by setting up its own manufacturing plant in Sheffield. The company has grown on the clinical success of its hip implants and continues today.

Scientific collaborators: Professors Pauwels and Osborn

He had two key scientific collaborations that helped him design hip implants that lasted decades. First, Ronnie Furlong sought out the World’s most notable expert in biomechanics, Professor Friedrich Pauwels of Aachen in Germany. This led him to design the Straight stem in 1979, one of the first straight stem prostheses for use with cement. Legend has it that Furlong’s concept of a straight stem was inspired by studying the effectiveness of a conical glass stopper in a wine decanter.

Secondly, he collaborated with Professor Osborn, Facio-Maxillary Surgeon in the University Hospital of Bonn. Professor Osborn heard of the failures of hip replacements due to loosening from his orthopaedic colleagues and he began to question whether hydroxyapatite could be used as an alternative fixation. On 23rd May 1985 Mr Furlong, whilst travelling to Switzerland, decided to deviate to Stuttgart in order to visit the factory of Feldmuhle AG, to see the production of the ceramic ball heads. He was met by Dr Dore who was interested in the prosthesis on to which Mr Furlong wanted to use the ceramic head. He needed to see the design of the taper. Quite uncharacteristically it so happened that Mr Furlong had his newly designed coned prosthesis in his pocket. On the large boardroom table at Dr Dore’s request, the prosthesis was displayed. There was no doubt as to the sudden excitement of Dr Dore. Mr Furlong was bemused. Dr Dore took the prosthesis and disappeared through the big double doors. After 15 minutes Mr Furlong was getting anxious as he remained awaiting his host’s return, accompanied by the entire R&D team of Feldmuhle. The ceramic ball head had been forgotten which seemed amusing to Mr Furlong since that was the object of the visit. Mr Furlong was then besieged with questions because it was realised that surely this was the prosthetic stem which would be appropriate for their newly developed ceramic coating. The very English name of Osborn was constantly referred to in the electric atmosphere which prevailed, and Mr Furlong became intrigued with this excitable confusion. A prosthetic box was brought to him containing a test coated stem to show the latest development of a bioactive ceramic coating. In fact, the stem was coated with hydroxyapatite ceramic (HAC).

Plain radiograph of a Furlong HAC stem with CSF cup.

This stem had been rejected by Professor Osborn due to inappropriate design. The excitement from the ecstatic group transferred to Mr Furlong himself. There was the coating. There was the wrong shaped stem lying in the box and there was the correct stem, his stem, on the table uncoated. For one moment it was all unreal. He thought an English source had eluded him as continuously the name of Osborn was referred to by the group and as the innovator behind the technology.

Mr Furlong was ready to return to England and find Osborn but, no, Professor Osborn was in Bonn and to Bonn he travelled the next day together with Dr Dore. There, the historic meeting of scientist and surgeon so long searching for each other became reality as Osborn and Furlong met. There was an immediate affinity which was momentous and held within itself a future revolution in orthopaedic history.

The latest Furlong hip can now be planned in three dimensions prior to surgery to ensure the optimum size and position so that the patient’s hip biomechanics are ideal for function and longevity.

Implant loosening, osteolysis and ‘cement disease’

The success of his HAC straight stem was partly due to a misinterpretation of the cause of loosening of cemented stems. In the 1980s, prosthetic loosening became the dominant factor leading to increasing revision surgery and cement fragmentation was considered largely responsible for this problem. 40,000 hip replacements were performed in Great Britain each year, of which 10% were revisions. As a result, cementless prostheses had begun to emerge, but the results were indifferent and disappointing and they too began to add to the revision surgeries.

However, Ronnie Furlong had appreciated that polyethylene debris, and not cement fragmentation, was the cause of the loosening and stated with conviction that the cause of loosening “to be cementless by itself was not enough”. The recognition that a similar pattern of bone osteolysis and loosening occurred in both cemented and cementless implants led to the understanding that polyethylene debris was the culprit.

Retrieval analysis: conclusive proof that HAC works

In November 1995, the histological findings of a nine-year explant, a patient of Mr Furlong’s, were presented by him at a symposium held at the Royal College of Surgeons of England and attended by 600 delegates worldwide. This explant was an HAC coated prosthesis of thelongest duration that had been retrieved in the world. The hydroxyapatite ceramic (HAC) had remained at full thickness in all stress areas and proved conclusively that the coating worked. Millions of implants have now been produced by many manufacturers using an HAC coating.

Throughout Mr Furlong’s long working life, he was supported by his wife, Eileen, and their achievements continued as the Furlong Charitable Research Foundation which became Orthopaedic Research UK, ORUK.