Finding puts Wits at forefront of bone rehab

Proffessor Ugo Ripamonti speaks about the work his unit is doing at the Bone Research Laboratory of the Medical Research council at the University of the Witwatersrand in Johannesburg. Picture:Paballo Thekiso

Proffessor Ugo Ripamonti speaks about the work his unit is doing at the Bone Research Laboratory of the Medical Research council at the University of the Witwatersrand in Johannesburg. Picture:Paballo Thekiso

Published Nov 19, 2012

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Durban - Professor Ugo Ripamonti, director of Wits University’s Bone Research Laboratory, once needed surgeons to tap into his own “bone bank” to have his arm, broken in an accident, rehabilitated.

The “bone bank” Ripamonti was referring to is a patient’s pelvis (iliac crest), where new bone is harvested to regenerate defective bone.

Even though this remains the best way for skeletal rehabilitation, because there is less chance of the body rejecting the implant, it is not always possible to harvest from this area.

In children, for example, “a surgeon cannot take bone from the iliac crest, as this would damage the growth of the child”.

The operation to harvest the material is also an additional surgical procedure on top of other, already complex, treatments to rehabilitate the skeleton of the patient.

Ripamonti said the only alternative was then to use bone donated to a bone bank – although this was not ideal.

“A lot of research has been implemented in the past several years to avoid the surgical harvest of a bone graft to regenerate bone,” he says.

Now, after many years of research and an international collaboration, Ripamonti’s work has finally yielded a viable alternative.

And although this new method of bone regeneration has only been used in a few cases, the results have been exciting.

Ripamonti explains that bone matrix is made from various components – including proteins. It’s these proteins or bone morphogenetic proteins (BMPs) that are the catalysts for making new bones.

“Worldwide research has discovered that the bone contains proteins which are capable of initiating the induction of bone formation; these proteins have been called bone BMPs.”

Not all proteins, however, are successful or safe to use for bone regeneration.

Working independently at Wits, Ripamonti found that other proteins, similar but different from the BMPs, are also capable of generating new bone.

One, named TGF- ß3, has been found to be a very powerful bone inducer when tested in primates. In addition TGF- ß3 can be manufactured outside the body, alleviating the need for harvesting from the pelvis.

And it is so quick to take that within days of an operation, evidence of new bone can be seen in a patient. This will give renewed hope to many patients diagnosed with tumours affecting the mandibular or the maxilla (facial bones used for chewing).

“My dream is to see all our discoveries translated to the bedside of many patients affected by severe craniofacial pathologies,” said Ripamonti. - Sunday Tribune

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