SLR - August 2021 - Raddison Veater

Calcaneal Fractures: 3d-Printing Model to Assist Spatial Weaving of Percutaneous Screws Versus Conventional Open Fixation-A Retrospective Cohort Study 

Reference: Zhang Y, Weng Q, Gu Y, Chen J, Yang Y. Calcaneal Fractures: 3d-Printing Model to Assist Spatial Weaving of Percutaneous Screws Versus Conventional Open Fixation-A Retrospective Cohort Study. Int Orthop. 2021 Jun 11. doi: 10.1007/s00264-021-05094-2. Epub ahead of print. PMID: 34117504.

Level of Evidence: Level 3 single-center retrospective cohort study

Scientific Literature Review

Reviewed By: Raddison Veater, DPM
Residency Program: Kaiser North Bay Consortium - Vallejo, CA 

Podiatric Relevance: This article provides a modified surgical approach for displaced intra-articular calcaneal fractures (DIACF) using 3D spatial weaving screw fixation (3D-SWSF). 

Methods: Patients with Sanders II and III DIACF were included into the study. CT images were taken of the affected calcaneus and contralateral calcaneus and converted into a 3D model reconstruction. The non-affected calcaneus was mirrored to simulate the affected calcaneus. The reduction model was constructed based on the mirror replication of the uninjured side which acted as guide for accurate fracture reduction of the affected calcaneus. The 3D reconstruction was done using 3.5 millimeters fully threaded screws. The screw placement design was divided into three main directions to a “spatial weaving structure”, providing a stable construct to support the calcaneus. The 3D-SWSF results were compared to the results of open reduction and internal fixation (ORIF) via the lateral extensile approach. 

Results: Thirty-one patients were in the 3D-SWSR group and 41 from the ORIF group. Average f/u time was 19.3 months. They found that surgical duration, hospital stay, operative blood loss, wound complications, and last follow up were remarkably decreased in the 3D-SWSR group. AOFAS and VAS scores were also found to be better in the 3D-SWSR group as compared to the ORIF group. At the one-year mark radiographs were compared between the two groups and although there were some minor differences, there were no significant differences in the Bohler’s angle, Gissane’s ankle and anatomical dimensions (height, width and length) of the calcaneus. 

Conclusions: The study showed that 3D-SWSF is an effective way of treating displaced intra-articular calcaneal fractures with shorter surgical duration and hospital stay, reduced risk of wound complications, and improved post-operative rehabilitation. The 3D model helps to provide a precise reconstruction model to improve accuracy in treating calcaneal fractures. Further studies comparing this approach to a sinus tarsi incision would be useful to evaluate whether the positive results were a function of the 3D technology or the incisional approach.

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