Custom-Made Total Talonavicular Replacement

NewsBot · Jul 29, 2015

Members do not see these Ads. Sign Up.
Custom-Made Total Talonavicular Replacement in a Professional Rock Climber
Sandro Giannini, MD, Matteo Cadossi, MD, PhD, Antonio Mazzotti, MD, Laura Ramponi, MD, Claudio Belvedere, PhD, Alberto Leardini, PhD
Jnl Foot and Ankle Surgery; Article in Press

Professional athletes are often eager to resume sporting activities at preinjury levels. When facing the challenge of restoring joint function after a complex articular fracture, innovative solutions must be explored. We describe the results of what we believe to be the first custom-made talonavicular prosthesis implanted in a professional rock climber who had developed post-traumatic ankle and talonavicular arthritis as sequelae of a complex talar and navicular fracture. Using computed tomography scan reconstruction of the contralateral healthy ankle and direct metal laser sintering, a custom-made talonavicular prosthesis was obtained and implanted using an anteromedial approach. The patient was clinically and radiographically evaluated every 6 months after surgery for 30 months. A 3-dimensional videofluoroscopic analysis was performed to assess the range of motion about the prosthesis. At the last follow-up visit, the functional scores were excellent (Tegner activity scale score of 9 of 10), and he had completely resumed his sporting activity. The American Orthopaedic Foot and Ankle Society score had increased from 36 to 81 points, and no signs of radiolucency were observed on the radiographs. The 3-dimensional videofluoroscopic analysis showed 15? of dorsiflexion and 4? of plantar flexion at the ankle. A customized solution is an option when the patient's expectations are not likely to be met by standard treatment, such as arthrodesis. A custom-made talonavicular prosthesis can be an effective solution for complex ankle injury sequelae in patients demanding high functionality.
Click to expand...

Ian Drakard · Jul 29, 2015

Now this is cool. Would love more details of the prosthesis if anyone has access?

Griff · Jul 30, 2015

.....

After considering the patient's expectations in terms of functional outcome, we decided to undertake surgical implantation of a custom-built total talonavicular replacement prosthesis to maintain the hindfoot and ankle structure and restore as much movement as possible. For this purpose, bilateral foot and ankle computed tomography scans were obtained and used to manufacture the prosthesis in 2 separate phases (Sintac srl, Biomedical Engineering, Trento, Italy).

First, from the computed tomography scans of the contralateral foot and ankle, a volume rendering was obtained. The shape of the required prosthesis was then designed to reconstruct the missing bones to fit the remaining joint surfaces. The custom-built prosthesis was fabricated by ?mirroring? the contralateral normal ankle, naviculocuneiform and talocalcaneal joints, and the talonavicular prosthesis, defining all the different parts to be replaced. The final computer-assisted design model of the prosthesis was completed with porous articular surfaces and a talar-navicular component with 2 channels to host the lag screws for fixation to the calcaneus. Second, the artificial talonavicular segment, which precisely replicated the healthy talonavicular complex, was manufactured using state-of-the-art laser technology by powder melting a cobalt-chromium alloy (cobalt 63.8%, chromium 24.4%, molybdenum 5%, tungsten 5.4%, silicone 1.2%, free of nickel, beryllium, and cadmium, according to standard DIN EN ISO
22674:2006).

With this technology, a special software program controlled the layer-by-layer laser beam melting of the alloy until the definite shape of the computer-assisted design model was created. In simple terms, the laser beam melted the molecules of metal powder that were deposited in a platform inside the sintering machine, where the 3-dimensional (3D) prosthesis was constructed layer by layer. Manufacturing the prosthesis required approximately 3 weeks, and the final implant weighed 475 g.
Click to expand...

RobinP · Aug 8, 2015

That is pretty awesome. It would be interesting to see how custom prostheses performed in other forms of arthroplasty. I know from some orthopod friends that the componentry choice is often critical in the success
One would imagine that a custom prosthesis stands a better chance of carrying success, assuming that the contralateral side was suitably symmetrical.
That being said, I am sure that like foot orthoses, in the right situation a modular set up is as good as a custom made solution
Very interesting.
If you had a choice of a ?30,000 knee custom hemi arthroplasty and a ?10,000 standard - which would you choose? (guessing at figures obviously?) if the evidence showed a statistically significant benefit of the custom over the standard

NewsBot The Admin that posts the news.

Ian Drakard Active Member

Griff Moderator

Attached Files:

TN implant.jpg

RobinP Well-Known Member

Total contact cast vs. custom-made temporary footwear

Custom-Made Foot Orthotics for People With Lower Limb Conditions

Effect by custom-made foot orthoses with added support under the first metatarsophalangeal joint

Plantar forefoot pain: ultrasound findings before and after treatment with custom-made foot orthoses

Custom-Made Foot Orthoses versus Prefabricated foot Orthoses

Effectiveness of custom-made foot orthoses for treating forefoot pain

Analysis of prescription characteristics for custom-made foot orthoses

Share This Page