Bionic plate design for calcaneal fracture treatment. A biomechanical analysis and first clinical results

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.

Are Variable-Angle Locking Screws Stable Enough to Prevent Calcaneal Articular Surface Collapse? A Biomechanical Study

PURPOSE

To compare fixed- or variable-angle locking screws in calcaneal fracture plates using a sawbones biomechanical model.

METHODS

Intra-articular calcaneal fractures were created in synthetic bones. Reduction and stabilization was performed with 3 different plates. In group A, a fixed-angle locking plate was used with screws fastened perpendicularly to the plate (3.5 LCP, DePuySynthes). In groups B and C (2.7 VA-LCP, DePuySynthes and 3.5 Aptus, Medartis, respectively), fracture fixation was performed using variable-angle locking plates. Biomechanical testing was conducted. Displacement of the subtalar articular surface, stiffness, maximum displacement, change in the angle of Gissane, and mode of failure under cyclic loading at 200 N, 600 N, and 1000 N (500 cycles each) were determined.

RESULTS

No statistically significant difference of articular surface dislocation under cyclic loading was detected. The stiffness and maximum displacement did not reveal any disparity as well. The change in the angle of Gissane showed only minor displacement of the articular surface.

CONCLUSION

In our study, the resistance of variable-angle locking plates against articular surface displacement was similar to fixed-angle locking screws.

Comparison of 2 plating techniques for lateral clavicle fractures, using a new standardized biomechanical testing setup

BACKGROUND

Conservative treatment of lateral clavicle fractures (Neer type II) often ends with unsatisfactory results for patients. Operative treatment is thus gaining acceptance. A retrospective study found success using a double plate technique for these injuries. For the current study, a standardized testing setup was developed to compare the mechanical properties of single versus double plate technique for lateral clavicle fractures.

METHODS

Six synthetic bones were tested for each technique. Neer type IIB fractures were created using computer-aided design (CAD). Fatigue testing was carried out with a cantilever bending test. Parameters measured were cycles undergone, failure load and stiffness at the point of failure.

RESULTS

The standardized testing setup was able to provide reproducible failures. The double plate technique lasted about 16,000 more cycles and withstood an additional 22.4 N on average.

CONCLUSIONS

The new modified standardized testing setup produced reproducible fixation failures for both clavicle fracture fixation techniques. The double plate technique seems to be mechanically superior to the single plate technique.

Radiological study of the secondary reduction effect of early functional exercise on displaced intra-articular calcaneal fractures after internal compression fixation

PURPOSE

Early post-operative exercise and weight-bearing activities are found to improve the functional recovery of patients with displaced intra-articular calcaneal fractures (DIACFs). We hypothesized that early functional exercise after surgery might have a secondary reduction effect on the subtalar joint, in particular the smaller fracture fragments that were not fixed firmly. A prospective study was conducted to verify this hypothesis.

METHODS

From December 2012 to September 2013, patients with unilateral DIACFs were enrolled and received a treatment consisting of percutaneous leverage and minimally invasive fixation. After surgery, patients in the study group started exercising on days two to three, using partial weight bearing starting week three, and full weight bearing starting week 12. Patients in the control group followed a conventional post-operative protocol of partial weight bearing after week six and full weight bearing after the bone healed. Computed tomography (CT) scanning was performed at post-operative day one, week four, week eight, and week 12 to reconstruct coronal, sagittal, and axial images, on which the maximal residual displacements of the fractures were measured. Function was evaluated using the American Orthopaedic Foot and Ankle Society (AOFAS) scoring scale at the 12th post-operative month.

RESULTS

Twenty-eight patients in the study group and 32 in the control group were followed up for more than 12 months; their data were collected and used for the final analysis. Repeated-measures analysis of variance (ANOVA) of the maximal residual displacements of the fracture measured on CT images revealed significant differences between the study and the control groups. There were interaction effects between group and time point. Except for the first time point, the differences between the groups at all studied time points were significant. In the study group, the differences between all studied time points were significant. Strong correlations were observed between the AOFAS score at post-operative month 12 and the maximal residual displacement of the fractures on the CT images at postoperative week 12.

CONCLUSIONS

Early functional exercise and weight bearing activity can smooth and shape the subtalar joint and reduce the residual displacement of the articular surface, improving functional recovery of the affected foot. Therefore, early rehabilitation functional exercise can be recommended in clinical practice.

Surgical complications of intra-articular calcaneal fracture treatment

Introduction: The authors present complications following surgical treatment of intra-articular calcaneus fractures, in regards to the surgical technique employed, based on their own clinical material. Materials and methods: The techniques analyzed included the Westhues’ technique and its modifi cation with additional bone stabilization by Kirschner wires and the percutaneous stabilization by Rapala. The research material covered the years from 1990 to 2012 and consists of 82 operated patients - 68 men (83%) and 14 women (17%). Analyzed calcaneus fractures were divided using the Essex-Lopresti classifi cation. Results: The authors of the article indicate that the most frequently registered complications of surgical treatment of intra-articular calcaneus fractures in early observation were thromboembolic complications and local infl ammatory reactions of the skin at the point of incision and placing the stabilizing material. During the long-term follow-up, the post-thrombotic syndrome and algodystrophic disorders were the most common. Conclusions: Factors contributing to the occurrence of the complications registered were fracture morphology, fixation of bone fragments by an excessive number of stabilizing materials and prolonged immobilization of the operated limb. Cite this article as: Golec P., Tomaszewski K.A., Nowak S., Dudkiewicz Z. Surgical complications of intra-articular calcaneal fracture treatment. Med Rehabil 2016; 20(2): 25-30.

Fall-induced fractures of the calcaneus and foot in older people: nationwide statistics in Finland between 1970 and 2013 and prediction for the future

BACKGROUND

Although fall-induced fractures of elderly persons are a major problem, epidemiologic knowledge on their time trends is limited. We assessed the trends in fall-induced fractures of the calcaneus and foot in older Finns between 1970 and 2013.

METHODS

The current trends in the number and incidence (per 100,000 persons) of fall-induced fractures of the calcaneus and foot of older Finns were determined by taking into account individuals 50-year-olds or older who were admitted to Finnish hospitals for primary treatment of such injury in 1970-2013.

RESULTS

The number and raw incidence of these fractures increased considerably between 1970 and 2013, from 64 (number) and 5.6 (incidence) in 1970, to 325 and 15.0, respectively, in 2013. The age-adjusted incidence of fracture was higher in men than women and showed a clear rise in both sexes in 1970-2013, from 7.2 to 15.2 in men (111% increase), and from 4.3 to 13.9 in women (223% increase). A similar rise was observed in the age-specific incidences. If trends in the age-specific fracture incidence continue at the same rate as were observed in 1970-2013, and the 50-year-old or older population increases as predicted (by 15% by the year 2030), the annual number of fall-induced fractures of the calcaneus and foot in this population will be 1.8 times higher in the year 2030 (580 fractures) than it was in 2013 (325 fractures).

CONCLUSIONS

The number of fall-induced fractures of the calcaneus and foot among Finns 50 years of age or older has risen sharply between 1970 and 2013 with a rate that cannot be explained merely by demographic changes. Further studies should examine the reasons for the rise and possibilities for fracture prevention.

Reduction and internal fixation of displaced intra-articular calcaneal fractures with a locking nail: a prospective study of sixty nine cases

PURPOSE

The best treatment for intra-articular fractures of the calcaneus is still debated. The aims of this study were to determine whether intrafocal reduction of thalamic fractures is effective, to evaluate whether a locking nail is able to maintain reduction of the articular surface and to analyse the functional results of this original method.

METHODS

This prospective study assessed 69 fractures treated with a locking fracture nail in 63 cases and with primary subtalar fusion in six (Calcanail (®), FH). Articular congruity and global reduction of the calcaneus was assessed in all patients by computed tomography (CT) scan three months postoperatively. Functional results were evaluated according to the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Score (AOFAS-AHS) and all complications recorded.

RESULTS

For the 63 fracture nails, the average AOFAS score was 85.9 at a mean final follow-up of 12 months. Only three secondary fusions were performed. For the six comminuted fractures requiring primary fusion, the average AOFAS score was 75.9 at the last follow-up.

CONCLUSIONS

The posterior intrafocal approach for both reduction and locked nailing of intra-articular calcaneal fractures has been proven as an effective and reliable procedure.