Unveiling Syndesmotic Malreduction: A Proof-of-Concept towards Portable Ultrasound Detection.

Objectives: To evaluate the utility and diagnostic performance of portable handheld ultrasound for evaluating fibular rotation at the distal tibiofibular articulation after syndesmotic disruption. Methods: Four above-the-knee cadaveric specimens were included. Syndesmotic disruption was precipitated by transecting the Anterior Inferior Tibiofibular Ligament, Interosseous Ligament, and Posterior Inferior Tibiofibular Ligament. Thereafter, a proximal fibular osteotomy was performed, and three conditions were modeled at the distal syndesmosis: 1) reduced, 2) 5 degree internal rotation malreduction, and 3) 5 degree external rotation malreduction. Two blinded observers performed separate ultrasonographic examinations for each condition at the level of both the anterior and posterior distal tibiofibular articular surfaces. Syndesmotic gap penetrance, defined as the ability of the P-US to generate signal between the distal fibula and tibia at the level of the incisura, was graded positive if the sonographic waves penetrated between the distal tibiofibular joint and negative if no penetrating waves were detected. The accuracy measures of the anterior and posterior gap penetrance were evaluated individually. Results: Our preliminary results showed that posterior gap penetrance showed good performance when detecting either internal or external rotational malreduction of the fibula with very good specificity (87.5%) and PPV (90.0%). On the other hand, the anterior gap penetrance showed limited performance when detecting either form of rotational malreduction. Conclusion: We introduced a novel sign, the "gap penetrance sign", best measured from the posterior ankle, which can accurately detect syndesmotic malreduction using P-US in a manner that does not require specific quantitative measurements and is readily accessible to early P-US users.

The Influence of Talar Displacement on Articular Contact Mechanics: A 3D Finite Element Analysis Study Using Weightbearing Computed Tomography.

BACKGROUND: Talar displacement is considered the main predictive factor for poor outcomes and the development of post-traumatic osteoarthritis after ankle fractures. Isolated lateral talar translation, as previously studied by Ramsey and Hamilton using carbon powder imprinting, does not fully replicate the multidirectional joint subluxations seen in ankle fractures. The purpose of this study was to analyze the influence of multiple uniplanar talar displacements on tibiotalar contact mechanics utilizing weightbearing computed tomography (WBCT) and finite element analysis (FEA). METHODS: Nineteen subjects (mean age = 37.6 years) with no history of ankle surgery or injury having undergone WBCT arthrogram (n = 1) and WBCT without arthrogram (n = 18) were included. Segmentation of the WBCT images into 3D simulated models of bone and cartilage was performed. Three-dimensional (3D) multiple uniplanar talar displacements were simulated to investigate the respective influence of various uniaxial displacements (including lateral translation, anteroposterior translation, varus-valgus angulation, and external rotation) on the tibiotalar contact mechanics using FEA. Tibiotalar peak contact stress and contact area were modeled for each displacement and its gradations. RESULTS: Our modeling demonstrated that peak contact stress of the talus and tibia increased, whereas contact area decreased, with incremental displacement in all tested directions. Contact stress maps of the talus and tibia were computed for each displacement demonstrating unique patterns of pressure derangement. One millimeter of lateral translation resulted in 14% increase of peak talar contact pressure and a 3% decrease in contact area. CONCLUSION: Our model predicted that with lateral talar translation, there is less noticeable change in tibiotalar contact area compared with prior studies whereas external rotation greater than 12 degrees had the largest effect on peak contact stress predictions. LEVEL OF EVIDENCE: Level V, computational simulation study.

Effect of sequential burr passes on minimally invasive akin and first metatarsal dorsiflexion osteotomies.

BACKGROUND: Minimally invasive surgical (MIS) osteotomies are increasing as a surgical option for treating midfoot and forefoot conditions. This study aimed to evaluate the impact of each burr pass on the degree of correction, gap size, and alignment in MIS Akin and first metatarsal dorsiflexion osteotomies (DFO). METHODS: MIS Akin and first metatarsal DFO were performed on ten cadaveric specimens. Fluoroscopic measurements included the metatarsal dorsiflexion angle (MDA), dorsal cortical length (MDCL), first phalangeal medial cortical length (PCML) and proximal to distal phalangeal articular angle (PDPAA). RESULTS: The average decrease in PCML with each burr pass was as follows: 1.53, 1.33, 1.27, 1.23 and 1.13 mm at the 1st to 5th pass, respectively. The MDCL sequentially decreased by 1.80, 1.59, 1.35, 0.75, and 0.60 mm. The MDA consistently decreased, and the PDPAA incrementally became more valgus oriented. CONCLUSION: On average, a first metatarsal dorsal wedge resection of 4.7 mm and first phalangeal medial wedge resection of 2.9 mm was achieved after 3 and 2 burr passes, respectively. This data may aid surgeons determine the optimal number of burr passes required to achieve the desired patient-specific surgical correction.

Comparison between achilles tendon reinsertion and dorsal closing wedge calcaneal osteotomy for the treatment of insertional achilles tendinopathy: A meta-analysis.

BACKGROUND: The debridement and Achilles tendon reinsertion (DATR) have been the most common surgical approach for the treatment of Insertional Achilles Tendinopathy (IAT), while dorsal closing wedge calcaneal osteotomy (DCWCO) has recently gained popularity as an alternative surgical option. This study aimed to systematically review the published literature on both surgical techniques and compare their clinical outcomes and complication rates. METHODS: A systematic review was performed according to the PRISMA guidelines using Medline, Embase, and Scopus databases. The inclusion criteria encompassed clinical studies reporting functional outcomes and complications, with a minimum of 10 patients and at least 12 months of follow-up. RESULTS: Seven studies (n = 169) were included for the analysis of DATR, and eight studies (n = 227) were included for the analysis of open DCWCO. Both groups showed a similar improvement in AOFAS score. The overall complication rates were 16.6% in the DATR group and 9.2% in the DCWCO group, but the difference was not statistically significant. However, there was a significantly higher incidence of wound complications in the DATR group (10.1%, 95% C.I.: 4.7-15.6) compared to the DCWCO group (2.5%, 95% C.I.: 0.6-4.4) as the confidence intervals did not overlap. CONCLUSIONS: Clinical outcomes and overall complication rates of both techniques were comparable, although DCWCO had a lower incidence of wound complications. Further research should be focused on prospective studies comparing the two techniques to corroborate the current findings. LEVEL OF EVIDENCE: Level IV; meta-analysis.

Medializing Calcaneal Osteotomy for progressive collapsing foot deformity alters the three-dimensional subtalar joint alignment.

BACKGROUND: A medializing calcaneal osteotomy (MCO) is considered as one of the key inframalleolar osteotomies to correct progressive collapsing foot deformity (PCFD). While many studies were able to determine the post-operative hind- and midfoot alignment, alternations of the subtalar joint alignment remained obscured by superposition on plain radiography. Therefore, we aimed to assess the hind-, midfoot- and subtalar joint alignment pre- compared to post-operatively using 3D weightbearing CT (WBCT) imaging. METHODS: Seventeen patients with a mean age of 42 ± 17 years were retrospectively analyzed. Inclusion criteria consisted of PCFD deformity corrected by a medializing calcaneal osteotomy (MCO) as main procedure and imaged by WBCT before and after surgery. Exclusion criteria were patients who had concomitant calcaneal lengthening osteotomies, mid-/hindfoot fusions, hindfoot coalitions, and supramalleolar procedures. Image data were used to generate 3D models and compute the hindfoot (HA), midfoot (MA) - and subtalar joint (STJ) alignment in the coronal, sagittal and axial plane, as well as distance maps. RESULTS: Pre-operative measurements of the HA and MA improved significantly relative to their post-operative equivalents p < 0.05). The post-operative STJ alignment showed significant inversion (2.8° ± 1.7), abduction (1.5° ± 1.8), and dorsiflexion (2.3° ± 1.7) of the talus relative to the calcaneus (p < 0.05) compared to the pre-operative alignment. The displacement between the talus and calcaneus relative to the sinus tarsi increased significantly (0.6 mm±0.5; p < 0.05). CONCLUSION: This study detected significant changes in the sagittal, coronal, and axial plane alignment of the subtalar joint, which corresponded to a decompression of the sinus tarsi. These findings contribute to our clinical practice by demonstrating the magnitude of alteration in the subtalar joint alignment that can be expected after PCFD correction with MCO as main procedure.

Diagnostic applications and benefits of weightbearing CT in the foot and ankle: A systematic review of clinical studies.

BACKGROUND: Foot and ankle weightbearing CT (WBCT) imaging has emerged over the past decade. However, a systematic review of diagnostic applications has not been conducted so far. METHOD: A systematic literature search was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines after Prospective Register of Systematic Reviews (PROSPERO) registration. Studies analyzing diagnostic applications of WBCT were included. Main exclusion criteria were: cadaveric specimens and simulated WBCT. The Methodological Index for Non-Randomized Studies (MINORS) was used for quality assessment. RESULTS: A total of 78 studies were eligible for review. Diagnostic applications were identified in following anatomical area's: ankle (n = 14); hindfoot (n = 41); midfoot (n = 4); forefoot (n = 19). Diagnostic applications that could not be used on weightbearing radiographs (WBRX) were reported in 56/78 studies. The mean MINORS was 9.8/24 (range: 8-12). CONCLUSION: Diagnostic applications of WBCT were most frequent in the hindfoot, but other areas are on the rise. Post-processing of images was the main benefit compared to WBRX based on a moderate quality of the identified studies.

Effect of sequential burr passes on osteotomy magnitude and calcaneal morphology in minimally invasive Zadek osteotomy.

PURPOSE: This study aimed to evaluate the impact of each burr pass on degree of correction, gap size and calcaneal morphology in MIS Zadek osteotomy. METHODS: MIS Zadek osteotomy was performed on ten cadaveric specimens using a 3.1 mm Shannon burr. After each burr pass, the osteotomy gap was manually closed, and the subsequent burr passes were carried out with the foot held in dorsiflexion, which was repeated five times. Lateral X-rays were taken before and after each burr pass. Two independent reviewers measured the dorsal calcaneal length after each burr passage, as well as changes in several calcaneal parameters including X/Y ratio, Fowler Philip angle, and Böhler angle. RESULTS: The average decrease in dorsal calcaneal cortical length with each burr pass was as follows: 2.6 ± 0.9 mm at the 1st pass, 2.4 ± 1 mm at the 2nd pass, 2 ± 1 mm at the 3rd pass, 1.6 ± 1 mm at the 4th pass, and 1.4 ± 0.7 mm at the 5th pass. The Fowler Philip and Böhler angles consistently decreased while the X/Y ratio consistently increased following each consecutive burr pass. Interobserver reliability analysis demonstrated good agreement for all parameters. CONCLUSION: The results revealed the trends of length and anatomical changes in the calcaneus with each burr pass. On average, a dorsal wedge resection of 10 mm was achieved after 5 burr passes. This data can aid surgeons in determining the optimal number of burr passes required for a particular amount of resection, ensuring the attainment of the desired patient-specific surgical outcome.

The hind- and midfoot alignment computed after a medializing calcaneal osteotomy using a 3D weightbearing CT.

PURPOSE: A medializing calcaneal osteotomy (MCO) is a surgical procedure frequently performed to correct an adult acquired flatfoot (AAFD) deformity. However, most studies are limited to a 2D analysis of 3D deformity. Therefore, the aim is to perform a 3D assessment of the hind- and midfoot alignment using a weightbearing CT (WBCT) preoperatively as well as postoperatively. METHODS: Eighteen patients with a mean age of 49.4 years (range 18-67) were prospectively included in a pre-post-study design. A MCO was performed and a WBCT was obtained pre- and postoperative. Images were converted into 3D models to compute linear and angular measurements, respectively, in millimeters (mm) and degrees (°), based on previously reported landmarks of the hind- and midfoot alignment. A regression analysis was performed between the displacement of a MCO and the obtained postoperative correction. RESULTS: The mean 3D hindfoot angle improved significantly preoperative compared to postoperative (p < 0.001). This appeared according to a linear relation with the amount of medial translation in a MCO (R2 = 0.84, p < 0.001). The axes of the tibia showed significant coronal as well as axial changes (p < 0.05). Analysis of the midfoot showed significant changes in the navicular height and rotation as well as the Méary angle (p < 0.05). Additionally, a linear trend between the midfoot measurements and amount of medial translation in a MCO was observed, but not significant (p > 0.05). CONCLUSION: This study demonstrates an effective 3D correction of an AAFD by a MCO according to a linear relationship. The concomitant formula can be used to perform a preoperative planning. The novelty is the comparative 3D weightbearing CT assessment of both the computed hind- and midfoot alignment after a medializing calcaneus osteotomy. This could improve accuracy of the currently performed preoperative planning in clinical practice.