How to assess consolidation after foot and ankle arthrodesis with computed tomography. A systematic review

Extensible lateral approach versus sinus tarsi approach for sanders type II and III calcaneal fractures osteosynthesis: a randomized controlled trial of 186 fractures

AIMS

Which is the best extensile lateral (ELA) or sinus tarsi (STA) approach for osteosynthesis displaced intraarticular calcaneal fracture (DIACF) is still debatable. The current RCT's primary objective was to compare the complications incidence after open reduction and internal fixation of DIACFs through STA vs. ELA. The secondary objectives were the differences in intraoperative radiation exposure, time to fracture union, functional and radiological outcomes.

METHODS

Between August 2020 and February 2023, 157 patients with Sanders type II and III fractures were randomly assigned to either ELA (81 patients with 95 fractures) or STA (76 patients with 91 fractures). The primary outcome was the incidence of complications. The secondary outcomes were Böhler's and Gissane angles angle, fracture union, and American Orthopaedic Foot and Ankle Society (AOFAS) score.

RESULTS

No statistical differences between both groups regarding basic demographic data, injury characteristics, and fracture classification; however, patients in the STA group were operated upon significantly earlier (4.43 ± 7.37 vs. 7 ± 6.42 days, p = 0.001). STA's operative time was significantly shorter (55.83 ± 7.35 vs. 89.66 ± 7.12 min, p < 0.05), and no statistical difference regarding intraoperative radiation exposure. The time to fracture union was significantly shorter in STA (6.33 ± 0.8 vs. 7.13 ± 0.7 weeks, p = 0.000). Skin complications (superficial or deep infection) and Subtalar osteoarthritis were significantly higher in ELA (18.9% vs. 3.3%, p = 0.001) and (32.6% vs. 9.9%, p = 0.001), respectively. The radiological parameters were significantly better in STA postoperatively and at the last follow up. The AOFAS scores were significantly better in STA (83.49 ± 7.71 vs. 68.62 ± 7.05, respectively, p = 0.000).

CONCLUSION

During osteosynthesis of Sanders type II and III DIACFs, STA is superior to ELA in terms of operating earlier, shorter operative time, fewer complications, and better radiological and functional outcomes.

Clinical and Radiographic Outcomes After Hindfoot and Ankle Arthrodesis Using Cellular Bone Allograft Augmentation: A Short Report

Background

Nonunion after ankle or hindfoot arthrodesis is associated with poor outcomes. Cellular bone allograft is an alternative to autograft for use in these procedures. The purpose of this study was to prospectively evaluate the early efficacy and safety of cellular bone allograft use in hindfoot and ankle arthrodesis procedures.

Methods

Fourteen patients undergoing hindfoot or ankle arthrodesis supplemented with cellular bone allograft were prospectively enrolled. Computed tomography (CT) scans were obtained postoperatively at set time points and reviewed by 3 fellowship-trained foot and ankle surgeons as well as 1 musculoskeletal radiologist. Primary outcome was CT-verified union, defined as >25% of joint surface. Complications were recorded and revision procedures offered as indicated.

Results

CT-verified union rate during the study period was 76.7% (23 of 30 joints). Union was 100% for the ankle joint (2 of 2), 50% for the talonavicular joint (5 of 10), 100% for the calcaneocuboid joint (8 of 8), and 80.0% for the subtalar joint (8 of 10). One patient underwent revision fusion procedure, and 1 patient underwent hardware removal during the study period.

Conclusion

Our initial experience suggests that use of cellular bone allograft augmentation in hindfoot and ankle arthrodesis may offer an alternative to autograft without potential of donor site morbidity.

Level of Evidence

Level IV, case series.

Cone-Beam CT of the Extremities in Clinical Practice

Cone-beam CT (CBCT) is a promising tool with increasing applications in musculoskeletal imaging due to its ability to provide thin-section CT images of the appendicular skeleton and introduce weight bearing, which accounts for loading forces that typically interact with and affect this anatomy. CBCT devices include an x-ray source directly opposite a digital silicon detector panel that performs a single rotation around an object of interest, obtaining thin-section images. Currently, the majority of research has been focused on the utility of CBCT with foot and ankle pathologic abnormalities, due to the complex architectural arrangement of the tarsal bones and weight-bearing nature of the lower extremities. Associated software can provide a variety of options for image reconstruction, including metal artifact reduction, three-dimensional biometric measurements, and digitally reconstructed radiographs. Advancements in this technology have allowed imaging of the knee, hip, hand, and elbow. As more data are published, it is becoming evident that CBCT provides many additional benefits, including fast imaging time, low radiation dose, lower cost, and small equipment footprint. These benefits allow placement of CBCT units outside of the traditional radiology department, including the orthopedic clinic setting. These technologic developments have motivated clinicians to define the scope of CBCT for diagnostics, surgical planning, and longitudinal imaging. As efforts are made to create standardized protocol and measurements, the current understanding and surgical approach for various orthopedic pathologic conditions will continue to shift, with the hope of improving outcomes. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.