Reliability of Modified Radiographic Union Score for Tibia Scores in the Evaluation of Femoral Shaft Fractures in a Low-resource Setting

Standard or Fin SIGN® nail? which option is better for the treatment of femoral fractures in low and middle-income countries?

PURPOSE

Femoral fractures are common in low and middle-income countries (LMIC), predominantly caused by high-energy trauma. The surgical implant generation network (SIGN®) program offers two different intramedullary nails in LMIC which are designed to be used without image intensifier free of charge for the patients: the SIGN standard nail (SSN®) and the SIGN Fin nail (SFN®). This study aimed to compare the results of the SSN® and the SFN® for the treatment of middle and distal shaft femoral fractures through a retrograde approach.

MATERIAL AND METHODS

This was a retrospective, descriptive, and non-experimental study including all consecutive patients who underwent surgical management of middle or distal shaft femoral fracture between January 2017 and May 2022 in an NGO hospital located in Freetown, Sierra Leone. The duration of surgery, type of reduction, complications like screw loosening, implant migration, anterior knee pain and non-union rate at six months of follow up were evaluated.

RESULTS

A total of 122 patients were included in the study. Group A: 60 patients were managed with SSN® and Group B: 62 patients with SFN®. The mean operative time was 104 min with SSN® and 78 with SFN® (p < 0.001). Open reduction of the fracture was necessary in ten (16.7%) patients with SSN® and 12 (19.4%) patients treated with SFN® (p = 0.69). Non-union was observed in one (1.7%) patient with SSN® and two (3.2%) patients with SFN® (p = 0.57).

CONCLUSIONS

Both options seem equally effective in treating midshaft and distal femoral shaft fractures. The SFN® reduces the surgical time, due to this fact, in polytraumatized patients, patients with bilateral femur fracture or patients with ipsilateral tibia fracture, it can be considered as the best option to be used. There was no statistical difference in the complications presented by the two groups.

Titanium versus stainless steel alloy bridge plates for distal femur fractures: Does callus form earlier with titanium?

INTRODUCTION

Distal femur fractures account for 3-6% of all femur fractures. Internal fixation of most distal femur fractures with an anatomic lateral locking plate should permit some motion at the metaphyseal portion of the fracture when secondary bone healing is planned by the operating surgeon. While several studies have been performed evaluating union rates for distal femur fractures with stainless steel and titanium plates, the timing of callus formation between stainless steel and titanium implants used as bridge plates for distal femur fractures (AO/OTA 33-A and -C) has been investigated to a lesser extent. We hypothesize that callus will be visualized earlier with post-operative radiographs with titanium versus stainless steel bridge plates.

METHODS

We retrospectively reviewed a consecutive cohort of patients over 18 years of age with acute AO/OTA 33-A and 33-C fracture patterns treated with an isolated stainless steel or titanium lateral bridge plate within 4 weeks of injury by a single fellowship-trained orthopedic trauma surgeon from 2011 to 2020 at one academic Level 1 trauma center. An independent, fellowship-trained orthopedic trauma attending surgeon reviewed anterior-posterior (AP) and lateral radiographs from every available post-operative clinic visit and graded them using the Modified Radiographic Score for Tibia (mRUST).

RESULTS

Twenty-five subjects were included in the study with 10 with stainless steel and 15 with titanium plates. There were no significant differences in demographics between both groups, including age, sex, BMI, injury classification, open versus closed, mechanism, and laterality. Statistically significant increased mRUST scores, indicating increased callus formation, were seen on 12-week radiographs (8.4 vs. 11.9, p = 0.02) when titanium bridge plates were used. There were no statistically significant differences in mRUST scores at 6 or 24-weeks, but scores in the titanium group were higher in at every timepoint.

DISCUSSION

In conclusion, we observed greater callus formation at 12 weeks after internal fixation of 33-A and 33-C distal femur fractures treated with titanium locked lateral distal femoral bridge plates compared to stainless steel plates. Our data suggest that titanium metallurgy may have quicker callus formation compared to stainless steel if an isolated, lateral locked bridge plate is chosen for distal femur fracture fixation.

Computer-Based Mechanobiological Fracture Healing Model Predicts Non-Union of Surgically Treated Diaphyseal Femur Fractures

As non-unions are still common, a predictive assessment of healing complications could enable immediate intervention before negative impacts for the patient occur. The aim of this pilot study was to predict consolidation with the help of a numerical simulation model. A total of 32 simulations of patients with closed diaphyseal femoral shaft fractures treated by intramedullary nailing (PFNA long, FRN, LFN, and DePuy Synthes) were performed by creating 3D volume models based on biplanar postoperative radiographs. An established fracture healing model, which describes the changes in tissue distribution at the fracture site, was used to predict the individual healing process based on the surgical treatment performed and full weight bearing. The assumed consolidation as well as the bridging dates were retrospectively correlated with the clinical and radiological healing processes. The simulation correctly predicted 23 uncomplicated healing fractures. Three patients showed healing potential according to the simulation, but clinically turned out to be non-unions. Four out of six non-unions were correctly detected as non-unions by the simulation, and two simulations were wrongfully diagnosed as non-unions. Further adjustments of the simulation algorithm for human fracture healing and a larger cohort are necessary. However, these first results show a promising approach towards an individualized prognosis of fracture healing based on biomechanical factors.