SLR - June 2021 - Qanita Ali

Three Dimension Printing Talar Prostheses for Total Replacement in Talar Necrosis and Collapse

Reference: Mu, Mi Duo et al. “Three Dimension Printing Talar Prostheses for Total Replacement in Talar Necrosis and Collapse.” International orthopedics, 10.1007/s00264-021-04992-9. 5 Mar. 2021, doi:10.1007/s00264-021-04992-9

Level of Evidence: Therapeutic Level IV 

Scientific Literature Review

Reviewed By: Qanita Ali, DPM
Residency Program: Beaumont Wayne, Wayne, MI 

Podiatric Relevance: Avascular necrosis of the talus causes talar collapse thus presenting a clinical challenge for podiatric surgeons. The common surgery for talar necrosis and collapse is talectomy and arthrodesis which presents with its own set of complications such as peritalar instability and limited ankle motion. Reconstructing the anatomy of the talus is a challenge in recovering biological function of the ankle. The authors of this study showcase that 3D printed patient-specific total talar prostheses allows anatomical reconstruction with improved patient satisfaction and improvement. 

Methods: Nine patients with complete talar necrosis and collapse underwent total talar replacement using 3D printed technology. The shape and size of the prosthesis were designed by CT imaging to match patient specific anatomy. The clinical outcomes were measured using radiographic parameters of the forefoot, hindfoot, and ankle alignment as well as AOFAS score, VAS score, ankle activity, recurrent pain, and peri-operative complications. 

Results: The mean follow up period was approximately two years (23.17 ± 6.65 months). On plain radiographs, degenerative arthritis and prosthetic dislocation were not found. Talar height and Meary’s angle showed significant changes pre-operative and post-operative (talar height, 27.59 ± 5.99 millimeters to 34.56 ± 3.54 millimeters and Meary’s angle, 11.73 ± 4.79 degrees to 4.45 ± 1.82 degrees). 

The AOFAS hindfoot score improved significantly from 26.33 ± 6.62 to 79.67 ± 3.14 and the VAS score decreased from 6.33 ± 1.03 to 0.83 ± 0.75. Pain relief, activities of daily living, and return to recreational activities scores were good to excellent. 

Conclusions: Surgical treatment options for patients with talar necrosis and collapse remains limited. Current treatment options involve bone grafts or ankle arthrodesis. Fusion of the ankle joint causes loss of ankle function. Autologous bone grafts can be used to fill bone defects but have the disadvantage of being unable to replicate the original talar shape and height. The authors of this study showcased that utilizing 3D printed technology to create a patient specific talar prosthesis allows for an efficient, precise, and personalized surgical treatment option for patients with talar necrosis and collapse. Pre- and post-radiographic findings showed improvement in forefoot and hindfoot alignment and measures of patient satisfaction showcased positive outcomes with no major complications documented. This technology offers promising results and a new method for creating individualized talar prosthesis. 3D printed technology is widely used in other specialty clinical practices and would be advantageous in the podiatric surgical realm.  

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