Dogs & Bones: Topsey’s turvy spine and Lucca’s limbs helped with bespoke titanium devices

November 14, 2018

Certain breeds of small dog are genetically prone to developing potentially life changing conditions.  In dachshunds and Shih Tzu’s, abnormal bone growth can sometimes cause their front paws to point outwards. And in pugs, and other breeds with corkscrew tails, are susceptible to spinal problems caused by mis-shapen bones. Fortunately, if diagnosed in time, these conditions can be treated with surgery.   

 

Improving Accuracy, Predictability of Outcomes & Reduce Theatre Times  

However, the size and weight of the patients can often present a challenge to veterinarian surgeons.  With such small animals, corrective surgery to drill and cut bones, stabilize vertebrae or reposition limbs is a laborious and intricate process, with little or no margin for error.   

Two British vets, Dr Kevin Parsons an orthopaedic vet based at the small animal hospital at Langford Vets, in Bristol, and a former colleague Tom Shaw a neurosurgeon, now at Willows Veterinary Centre and Referral Service in Solihull are pushing the boundaries of the use of additive manufacturing in veterinary science and are applying it to both scenarios.  

Since 2016, Parsons and Shaw have been using custom 3D-printed anatomical guides, surgical guides and titanium implants in daily practice with animals referred to them suffering from angular limb deformity or spinal malformation. In doing so, they have not only been able to improve surgical accuracy and the predictability of outcomes, but also reduce theatre time. 

 “Taking this approach with additive has resulted in a improved preoperative planning, reduced surgical time and more predictable outcomes,” said Dr Kevin Parsons. 

Integral to Langford Vets’ additive journey has been its partnership with Swansea-based CBM Wales (CBM) - a commercially focused advanced research, product development and batch manufacturing facility, established by the University of Wales Trinity Saint David.

Dr Ffion O’Malley and an experienced team of additive manufacturing designers and engineers at CBM, oversee production of bespoke surgical guides (either in polymer or metal) and titanium implants to match exactly to each individual patient’s anatomy to restore mechanical and/or aesthetical functions. Each implant design, follows precise specifications from the Langford Vets’ surgical team, using CT or MRI diagnostic imaging data, and is manufactured on a GE Additive Arcam EBM Q10plus on site at CBM’s facility in South Wales. 

The Q10plus is particularly well-suited for medical implant manufacture and has been developed for easy powder handling and fast turnaround times. The EBM process takes place in a vacuum and at elevated temperatures, which results in stress-relieved implants with properties better than cast and comparable to wrought materials.  

The bespoke implants are built in Titanium Ti6Al4V ELI, which is certified to the USP Class VI standard for biocompatibility and is extensively used for FDA and CE marked implants. CBM has ISO 9001:2015 certification for the provision of a design, prototyping and small batch manufacturing service and ISO 13485:2016 & EN ISO 13485:2016 certification for the design and manufacture of custom made 3D-printed surgical guides and implants. 

 

Meet Lucca the Shih Tzu 

dog

Image credit: Langford Vets

Image credit diagnostic images/ surgical guide: CBM Wales

dog leg Diagnosis: Lucca at aged one was diagnosed by Dr Kevin Parsons with angular limb deformity.  CBM was briefed by Dr Parson to design and additively manufacture a cutting and repositioning surgical guide required to reposition and straighten the limb and a titanium implant to hold the limb in its new repositioned location.
dog Repositioning: the desired result was for the angular limb to be repositioned to mimic the opposite side limb. The lower limb was to be repositioned into its preferred location and screw trajectories were planned to hold the correction implant in place. 

do

Surgical Guides: two cutting planes were used to guide a v-cut to achieve the correct planned repositioned angle of the limb. Four K-wires were placed in the limb to be used alongside the two surgical guides to re-orientate the lower limb. The bone bound surface of this surgical guides contoured the anatomy so that it located and fit accurately onto the bone. 

The four K-wires were used alongside the Repositioning Guide to orientate the lower limb into its correct planned position. The bone bound surface of this surgical guide contoured the anatomy so that it located and fit accurately onto the bone.

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Implant: 10 screw holes were designed onto the implant to attach it to the limb. 10 x 2.4mm screws specified by the surgeon. The bone bound surface of this Titanium implant contoured the anatomy so that it located and fit accurately onto the bone.

 

Meet Topsey the Pug 

pug Image credit: Langford Vets
Image credit diagnostic images/surgical guide: CBM Wales
pug2 Diagnosis: Topsey, at aged one, was diagnosed by Tom Shaw with hind limb weakness caused by a severe spinal malformation.  CBM Wales were briefed to produce a stabilisation implant required to work in conjunction with a surgical drilling guide.
pug3 Surgical Guide: Five drill cylinders were used to guide the pilot drill to achieve the correct trajectories. The bone bound surface of this surgical guide contoured the spinal anatomy so that it located and fit accurately onto the bone.
pug4 Implant: Ten screw holes were designed onto the implant and located in the same position as the drill cylinders to achieve the correct trajectories. The bone bound surface of this Titanium implant contoured the spinal anatomy so that it located and fit accurately onto the bone.
 


Dr Ffion O’Malley and Lloyd Stoker from CBM Wales will present at the GE Additive booth (Hall 3.0, Booth D30) at formnext on November 14, between 14:00-14:15 and are available for media interviews before or afterwards.