A Three-Dimensional Finite Element Analysis of Displaced Intra-Articular Calcaneal Fractures

3D mapping of intra-articular calcaneal fractures

To determine the pattern of intra-articular calcaneal fractures (ICFs) by a three-dimensional (3D) mapping and determine whether there were consistent fracture patterns and comminution zones. In this study, 67 patients with ICFS by CT scan were included. The calcaneal fractures fragments in CT were multiplanar reconstructed and virtual reduced. 3D heat mapping was subsequently created by graphically superimposing all fracture lines onto a standard calcaneal template. The cohort included 26 (38.8%) left calcaneal fractures, 27 (40.30%) right calcaneal fractures, and 14 (20.9%) cases with bilateral fractures. Comminuted fractures accounted for 92.5%. Sagittal 3D mapping shows that the fracture line is mainly concentrated at the critical angle of Gissane and extending rear to the posterior of the tuberosity of the lateral wall and the anterior of the medial process of the calcaneus tuberosity but with more significant variation in the medial wall. The average angle of fracture lines concerning the long calcaneal axis (LCA) was 29.1° and 19.2° in the lateral and medial walls. Axial 3D mapping shows that fracture lines were primarily concentrated in the anterior area to the posterior joint facet and extending along the rear joint facet and calcaneus sulcus to the posteriorly of the tuberosity. The mean angle of fracture lines concerning the LAC was 11° in the axial wall. Our data provided elucidated that ICFs have consistent characteristic fracture patterns and comminution zones. This study provides visual guidelines for understanding fracture morphology, which may assist with fracture classification, preoperative planning, development of fixation concepts.

Biomechanical Study Concerning the Types of Resection in Arthrodesis of First Metatarsophalangeal Joint

This work concerns a biomechanical study aiming to ascertain the optimal type of joint resection when performing a joint arthrodesis. A 3-dimensional digital model of the first metatarsophalangeal joint including the entire first metatarsal bone and proximal phalanx using CT scans of the forefoot was created. Using this computer model, 4 types of resections; ball-and-socket, flat-on-flat, wedge 90°, and wedge 100° were simulated. Parameters measured using this model were the force necessary to separate the 2 fused surfaces, the surface area of the resected surfaces and the shortening of the first ray. By measuring the reactive force necessary to separate the phalanx from the first metatarsal, the 90° wedge resection was found to be the most stable, with comparable results in the case of the 100° wedge resection. Wedge resections are also more favorable when comparing the shortening of the first ray. Wedge resections, though being more technically difficult to perform prove to be the most stable for metatarsophalangeal joint-1 arthrodesis using this model.

Fixation by Open Reduction and Internal Fixation or Primary Arthrodesis of Calcaneus Fractures: Indications and Technique

The quest for the best treatment of displaced intraarticular calcaneal fractures continues. The open reduction and internal fixation of displaced intraarticular calcaneal fractures yields the best results if anatomic reduction is obtained and complications are avoided. The sinus tarsi approach is becoming the new gold standard. In cases with severe comminution or when anatomic reduction cannot be obtained, a primary subtalar arthrodesis is a valuable option, if the overall anatomy of the calcaneus is corrected first. This review discusses the open reduction and internal fixation of displaced intraarticular calcaneal fractures and the indications and technique of the primary arthrodesis.

Patient-specific instrument-assisted minimally invasive internal fixation of calcaneal fracture for rapid and accurate execution of a preoperative plan: A retrospective study

Background

Traditional methods for minimally invasive internal fixation (MIIF) of calcaneal fractures require extensive intraoperative fluoroscopy, and fracture recovery is usually not ideal. We developed a new surgical procedure using digital surgical simulation and constructed a patient-specific instrument (PSI) for calcaneal fracture that we used during the operation. This study investigated whether PSI-assisted MIIF of calcaneal fracture enables rapid and accurate execution of the preoperative plan.

Methods

We retrospectively analyzed patients with Sanders type III or IV fresh calcaneal fractures who had undergone PSI-assisted MIIF at our hospital from January 2016 to December 2018. We analyzed perioperative data including intraoperative fluoroscopy time, concurrence of internal fixation actual usage (IFAU) with the preoperative plan, surgery time, and complications. We also compared pre- and postoperative actual measurements from X-ray radiographs and computed tomography images including Böhler, Gissane, and calcaneus valgus angles; subtalar joint width; and calcaneal volume overlap ratio with the preoperative design. All patients had been followed up and their American Orthopedic Foot and Ankle Score (AOFAS) score was available.

Results

Mean intraoperative fluoroscopy time was 3.95 ± 1.78 h; IFAU in 16 patients (16 ft) was the same as the preoperative plan; mean surgery time was 28.16 ± 10.70 min; and none of the patients developed complications. Böhler, Gissane, and calcaneus valgus angles and subtalar joint width did not differ between pre- and postoperative plans; however, the actual preoperative values of each of these parameters differed significantly from those measured postoperatively. The calcaneal volume overlap ratio with the preoperative design was 91.2% ± 2.3%. AOFAS scores increased with time, with significant differences in the score at each time point.

Conclusions

The newly developed PSI-assisted calcaneal fracture MIIF method can rapidly and accurately execute the preoperative plan.

Closed Manipulation, Intraosseous Reduction, and Rigid Internal Fixation for Displaced Intra-Articular Calcaneal Fractures

Although open reduction and internal fixation for treating displaced intra-articular calcaneal fractures remain common, difficulty obtaining and maintaining both calcaneal morphology and subtalar articular surface reduction remain. In addition, open approaches induce a significant risk of wound-healing complications. For this reason, closed manipulation to restore calcaneal morphology, intra-osseous fracture reduction, and rigid locked nail fixation was developed and validated for clinical use. Conversion to an immediate primary or delayed reconstructive subtalar joint arthrodesis using the same instrumentation remains unique to this system. This article reviews the CALCANAIL surgical technique for performing operative fixation of displaced intra-articular calcaneal fractures.