Posterior Facet Research Articles

The Relationship Between Fibular Notch Anatomy and ATFL Rupture

The anterior talofibular ligament (ATFL) is the first to be damaged during a lateral ankle sprain. Dynamic and static structures have been investigated to better understand ATFL rupture, but the predisposing factors have not been fully elucidated. This study aims to define the fibular notch version that can evaluate the position of the fibular notch relative to the tibia and investigate the relationship between the fibular notch version (FNV) and ATFL rupture. This study included 71 patients with isolated ATFL rupture diagnosed clinically and radiologically and 71 control patients without any foot or ankle pathologies. Anterior facet length (AFL), posterior facet length (PFL), anterior-posterior facet angle (APFA), fibular notch depth (ND), and FNV measurements were performed on axial magnetic resonance images (MRI). We defined FNV as a parameter that evaluates the fibular notch's relative position to the distal tibia. The mean FNV was 16.6° ± 4.9° in patients with ATFL rupture and 12.4° ± 5.6° in the control group; when both groups were compared, FNV measurements were significantly higher in patients with ATFL rupture (p=.002). The mean APFA was 123.9° ± 10° in the group with ATFL rupture and 129.7° ± 7.8° in the control group. When both groups were compared, APFA was significantly lower in patients with ATFL rupture (p=.014). There was no significant difference between the groups regarding AFL, PFL, and ND. A more posterior (retroverted) fibular notch and a lower fibular notch angle seem to be associated with higher rates of ATFL rupture.

Multiple Reconstructive Osteotomy Treating Malunited Calcaneal Fractures Without Subtalar Joint Fusion.

Various surgical techniques have been reported in treating calcaneal malunions over the decades, while the operations on single plane were accompanied by respective limitations. The purpose of this study is to evaluate the efficacy of a novel multiple reconstructive osteotomy for treating malunited calcaneal fractures without subtalar joint fusion. From March 12, 2010, to August 17, 2017, 10 patients (10 feet) with malunited calcaneal fractures were treated with multiple reconstructive osteotomy with subtalar joint-preserving operations. All patients were treated with a corrective osteotomy, joint realignment, soft tissue balancing, and secondary internal fixation at a mean of 5.6 ± 2.41months since the initial injury. With the utilization of the multiple reconstructive osteotomy, the posterior facet was restored to preserve the subtalar joint. All patients were evaluated clinically and radiographically at a mean follow-up of 3.04 ± 1.21 years. All patients were subjectively satisfied with the treatment. The average time to union was 12.2 ± 1.11 weeks. The American Orthopedic Foot and Ankle (AOFAS) ankle and hind foot score was 86.3 ± 4.45 (t=27.64, P < 0.0001, paired t-test), which was significantly higher than the preoperative assessment. Postoperative radiographic assessment revealed great improvement in Böhler's angle (from 25.4° to 86.3°), talocalcaneal height (65.15-72.68 mm) and Calcaneus-talus angle (from 34.46° to 39.7°). One patient had mild discomfort after a 1-h brisk walk. One patient was suspected to have early posttraumatic arthritis of the subtalar joint based upon radiographic evidence during the follow-up, but the patients could walk normally for a long time without pain. Multiple reconstructive osteotomy is an effective way to restore the calcaneal morphology and preserve the subtalar joint for selected calcaneal malunion.

Study of outcome of calcaneum fractures treated with calcaneum plate or cc screw

Background and Aims: Conservative treatment for displaced intra-articular fracture calcaneum can lead to incongruence of the posterior facet and, incongruence of the calcaneocuboid joint. Therefore surgical treatment is advocated to restore anatomy of calcaneum and reduce complications like subtalar arthritis, malunion and pain while walking. Aim of study is to study functional outcome of fractures treated with calcaneum plate or CC screw.Material and Methods: Total 20 cases were studied fom June 2021 to July 2022 in SSG hospital of calcaneum fractures treated surgically and monthly follow up were taken. Fracture classified on basis of Sanders classification and treated with plate or screw depending on type. Post-operative BK slab for 6 weeks and partial weight bearing till 3 months till sign of union visible.Results: 75% showed excellent results 20% good and 5% poor results.Discussion and Conclusion: Lateral approach to the calcaneum is more widely followed worldwide providing wide exposure of subtalar joint decompression of lateral wall, no risk of any injury to neurovascular structure and wide area for internal fixation. Early mobilization to prevent ankle stiffness. Meticulous surgical techniques, respect for soft tissues, antibiotics are essential to minimize the postoperative infection and skin problems.

Talar Arthroscopic Reduction and Internal Fixation (TARIF): A Novel All-Inside Soft-Tissue-Preserving Technique.

Talar Arthroscopic Reduction and Internal Fixation (TARIF): A Novel All-Inside Soft-Tissue-Preserving Technique.

Comparison of sinus tarsi approach versus extensile lateral approach in the management of displaced intra-articular calcaneal fractures: A single-center study.

Controversy still exists for optimal treatment for displaced intra-articular calcaneal fractures (DIACFs). Conven-tionally, the extensile lateral approach (ELA) has been the most preferred approach. Although ELA provides excellent fracture access and direct evaluation of the depressed posterior facet, this approach has a high rate of serious complications, such as hematoma, superficial/deep infection, and wound healing issues. To overcome such complications, more minimally invasive techniques including external fixation, percutaneous fixation, arthroscopic assisted fixation, and sinus tarsi approach (STA) have been recently described. The primary aim of this study was to compare STA and LEA in the treatment of DIACFs. Patients who were operated for DIACFs in our clinic were included in the study. Patients with closed DIACFs of Sanders Type II, III, IV, and over 18 years of age were identified. Physical examinations and radiological evaluations of the patients were per-formed, and clinical scores were filled. Patients were divided into subgroups according to the Sander's classification and comparisons were made again according to these subgroups. There were 37 patients (four female and 33 male) in STA group and 44 patients in LEA group (six female and 38 male). The mean age was 44.42±13.57 years (range, 18-61) for STA group and 37.32±11.09 years (range, 18-56) for the LEA group. In clinical outcomes, except for short-form survey (SF-12)/MCS-12 (Mental Score) and visual analog scale score, all the parameters were signifi-cantly better in STA group compared to LEA group. No significant difference was observed between the two groups in radiographic results, except for the Böhler angle. Significantly less infection occurred in the STA group compared to LEA group (P=0.021). According to Sander's classification, American Orthopedic Foot and Ankle Society, foot and ankle disability index, and SF-12/PCS-12 and foot function index scores, no significant differences were determined between STA and LEA groups for Sanders Type 2, whereas the values were considerably higher in STA group than in LEA group for Sanders Type 3 and 4. In DIACFs, STA is considered a safe and effective method for restoring the width, height, and length of the calca-neus and reconstruction of joint alignment and has now become our standard technique for all calcaneal fractures requiring operative treatment.

Treatment of peroneal spasmodic valgus foot with posterior subtalar fusion using a tightly packed iliac crest bone graft without fixation

Abstract Purpose The aim of this work is to study the result of posterior subtalar fusion as a modality of treatment of idiopathic spasmodic valgus feet. We study the effect of using a tightly impacted iliac crest bone graft to achieve stable joint distraction without additional fixation. Materials and Methods The study was done in the period between June 2017 and January 2019. Patients’ age ranged from 12 to 16 years. Patients were all treated with subtalar fusion at the level of the posterior facet. A wedged tricortical iliac crest bone graft was tightly impacted in the joint with its base facing laterally. No additional fixation methods were used. Patients were followed radiologically and functionally using the American Orthopedic Foot and Ankle Society Ankle–Hind foot scale (AOFAS-AHS). Results The study included 12 males and one female with a mean age of 13.5 ± 1.2 years. Five cases were bilateral and eight cases had unilateral affection with a total 18 feet. The mean follow-up period averaged 12 months (6–18) months. The AOFAS-AHS significantly increased from a preoperative mean of 41.2 ± 1.8 points to a postoperative mean of 82.8 ± 3.6 points (P value &lt;0.001), with a significant improvement in the radiological parameters used to evaluate the deformity. Conclusion Operative treatment in form of subtalar fusion is a good surgical option that showed significant improvement of symptoms and deformity correction. The technique of distraction bone block using wedged iliac graft allows a stable fusion and avoids hardware complications.

Artículo traducido] Configuración y localización óptima de los tornillos posteriores en las fracturas de calcáneo Sanders 2B: estudio biomecánico

BackgroundCalcaneal fractures can be high energy intra-articular injuries associated with joint depression. Challenges to fracture reduction include lateral wall blow out, medial wall overlap, comminution and central bone loss. Secondary deformity such as hindfoot varus alters foot biomechanics. Minimally invasive approaches with indirect reduction of the calcaneal tuberosity to maintain the reduction using posterior screws is routinely being used in the treatment of joint depression fractures. Biomechanically, optimum screw numbers and configuration is not known. Biomechanical studies have evaluated and proposed different screw configurations, however, it is not clear which configuration best controls varus deformity. This study aims to determine the optimum screw configuration to control varus deformity in Sanders 2B calcaneal fractures. MethodsSawbone models were prepared to replicate Sanders type 2-B fracture, with central bone loss and comminution. 0.5 cm medial wedge of the calcaneal tuberosity was removed to create varus instability. After stabilising posterior facet with a single 4 mm partial threaded screw, and applied an 8 hole contoured plate to stabilise the angle of Gissane, inserted one or two 7 mm cannulated partially threaded CharlotteTM (Wright Medical Technology, Memphis, USA) Headless Multi-use Compression (under image guidance) extra screws to control varus and subsidence deformity of the fracture. Coronal plane displacement of the dissociated calcaneal tuberosity fragment relative to the body when applying 5 N, 10 N and 20 N force was measured in millimetres (mm). Results2 screws inserted (one medial screw into the sustentaculum talus from inferior to superior and, one lateral screw into the long axis anterior process) provides the least displacement (0.88 ± 0.390 at 5 N and 1.7 ± 1.251 at 20 N) and the most stable construct (p < 0.05) when compared to other configurations. A single medial screw into the sustentaculum tali (conf. 3) resulted in the least stable construct and most displacement (4.04 ± 0.971 at 5 N and 11.24 ± 7.590 at 20 N) (p < 0.05). ConclusionThis study demonstrates the optimal screw configuration to resist varus in calcaneal fractures using minimally invasive techniques. Optimal stability is achieved using 2 screws; one located along the long axis of the calcaneus (varus control) and the other placed in the short axis directed towards the posterior facet of the calcaneus (control varus and subsidence). Further cadaver research would help evaluate optimal screw placement in simulated fractures to further assess reproducibility.

Racial differences in prevalence and anatomical distribution of tarsal coalition

Previous studies have reported a prevalence of tarsal coalition of 0.03–13%. Calcaneonavicular coalition is known as main anatomical type, and the bilateral occurrence of tarsal coalition is known to be 50% or more. These are the results of studies on Caucasians, there have been few studies targeting large number of East Asians so far. We hypothesized that the prevalence and characteristics of tarsal coalition in East Asians might differ from those in Caucasians. The medical records of 839 patients who underwent bilateral computed tomography on foot and ankle in our hospital from January 2012 to April 2021 were retrospectively reviewed. The overall prevalence was 6.0%, talocalcaneal coalition was the most common anatomical type. The overall bilateral occurrence was 56.5%, talocalcaneal coalition had the highest bilateral occurrence (76.0%) among anatomical types. Isolated union of the posterior facet was the most common subtype of talocalcaneal coalition (43.2%). Talocalcaneal coalition had a significantly higher proportion of coalition-related symptomatic patients than calcaneonavicular coalition (p = 0.019). Our study showed a similar trend to other East Asian studies, confirming the existence of racial differences. The possibility of tarsal coalition in foot and ankle patients in East Asians should always be considered, and bilateral examination is essential for diagnosis.

Intramedullary nailing for calcaneal fractures: what are the available techniques? A review of the literature

Objective. Displaced intra-articular fractures of the calcaneus (DIACF) may be treated in several ways. In recent years, intramedullary locking devices (ILD) have been proposed with the aim to reduce complications and improve long-term results. In this regard, we have reviewed the literature in order to identify devices currently available and evaluate their characteristics. Methods. Following a PRISMA checklist, Medline, Scopus and EMBASE databases were searched to identify studies reporting use of ILDs to treat DIACFs. In this review, only technical notes were included. Manuscripts selected were critically analysed in order to highlight common points and differences among surgical techniques. Results. Overall, four technical notes dealing with ILDs were found, of which two concerned the Calcanail® (FH Orthopedics, Heimsbrunn, France) and two the C-Nail® implant (Medin, Nov. Město n. Moravě, Czech Republic). While the Calcanail® is stabilised by two screws and allows indirect reduction of the posterior facet, the C-Nail® involves direct visualisation of the joint space and use of multiple multi-directional screws to achieve final stabilisation. Conclusions. Although similar in the design, the Calcanail® and the C-Nail® lead to the reduction and stabilisation of fragments through different mechanisms. In both cases the restoration of heel height and anatomical reduction of the subtalar joint are the primary goals of surgery.

Percutaneous reduction and cannulated screw fixation assisted by 3D printing technology of calcaneal fractures in children

BackgroundPercutaneous reduction and cannulated screw fixation (PR + CSF) for treatment of calcaneal fractures in pediatric patients has been proven to achieve satisfactory outcomes with few complications. But it is also a difficult technology due to the limited exposure and surgeons are unable to reduce articular surface under direct vision. The purpose of this study was to analyze the outcomes of applying 3D printing technology to preoperative preparation and Intraoperative operating for the treatment of calcaneal fractures in children. MethodsPediatric patients with calcaneal fractures from January 2010 to December 2018 were reviewed during study period. Preoperative radiographs and computed tomography scans were collected to classify the fractures, reconstruct 3D printed model and evaluate postoperative outcomes. The blood loss, operative time, number of fluoroscopies, surgeon and patient satisfaction were used to assess the effectiveness, feasibility and safety of 3D printing technology. Functional results were measured by American Orthopedic Foot and Ankle Society (AOFAS) hindfoot score. Result12 patients (10 boys and 2 girls) with 17 fractures were involved in our study. There were significant differences in the average Böhler angle before operation compared with that after operation and at last follow-up (P < 0.001). Similarly, the calcaneal height and length postoperatively and at the end of follow-up time were proved to have significant difference (P < 0.05) compared to preoperative. CT scan showed good reduction of the posterior facet according to Goldzak index. The average subjective AOFAS hindfoot score was 94.1. Both patients and surgeon made sense of the 3D printed model that can help them getting more information about the factures and making preoperative plans. No wound complication was found in this study. ConclusionThis study indicated that percutaneous reduction and cannulated screw fixation (PR + CSF) assisted by 3D printing technology in the treatment of calcaneal fractures in pediatric patients achieve good outcomes, with specific preoperative preparation, satisfactory functional recovery and fewer complications. Level of evidenceIII.

OUTCOMES OF OPEN REDUCTION AND INTERNAL FIXATION OF FRACTURE OF NECK OF TALUS

Background: Talus is the second largest tarsal bone with unique importance regarding its location and anatomy . It is an osseous link between foot and the leg and has got a pivotal role in overall foot function . It has got three important articulations at tibiotalar , talocalcaneal and talonavicular joint . It is divided into body , neck and posterior facets. Almost 70% surface of talus is covered with articular cartilage . Its blood supply is predominantly extraosseous and is at risk during fractures .&#x0D; Objectives : The aim of our study is to observe the long term outcomes after surgical treatment of fracture neck of talus .&#x0D; Study design : Prospective cross sectional study .&#x0D; Study setting : Department of Orthopedic Surgery Services hospital , Lahore&#x0D; Study duration : From Dec 2017 – Feb 2020&#x0D; Methodology: After approval from hospital ethical review board , total number of 30 patients with fracture neck of talus , both males ( 20 patients ) and females ( 10 patients ) were included in the study . Each patient underwent X-rays of ankle joint AP , LAT and ankle mortis views .. All these fractures were fixed with 4 mm cannulated screw by using combined anterolateral and anteromedial approach.&#x0D; Results: Post-traumatic arthritis was observed in 15 patients (50.0%) out of the 30 patients with 10 (75.0 %) patients at subtalar joint and 5 (25.0 %) patients at ankle joint. Among these 30 patients , 8 (26.7%) patients were having Hawkins type 2 , 14 (46.6%) with Hawkins type 3 and remaining 8 (26.7%) patients with were having Hawkins type 4 fractures. Osteonecrosis was mostly observed in Hawkins type 3 fractures 6 (42.8%) in Hawkins type 3, 2 (25.0%) patients in Hawkins type 2 fractures and 1 (12.5%) patient in Hawkins type 4 fractures. 1 (3.3 %) patient developed non-union and 1 (3.3 %) patient developed delayed union. 4(13.3 %) patients developed the superficial infection which was treated with IV antibiotics and wound irrigation .&#x0D; Conclusion: We concluded from our study that familiarity with the complex vascular , bony , surgical anatomy and techniques for rigid fixation of fractures is of utmost importance for fracture neck of talus . Rate of osteonecrosis , arthritis , mal-union and non-union are still high even in the presence of rigid internal fixation of these fractures

MRI changes of adjacent segments after transforaminal lumbar interbody fusion (TLIF) and foraminal endoscopy: A case-control study.

Background:Intervertebral foramen endoscopy has developed rapidly, but compared with transforaminal lumbar interbody fusion (TLIF), the progress of degeneration is unknown. We aim to compare the changes of intervertebral disc and intervertebral foramen in adjacent segments after TLIF and endoscopic discectomy for patients with lumbar disc herniation (LDH).Methods:From 2014 to 2017, 87 patients who were diagnosed with single-level LDH and received surgery of TLIF (group T, n = 43) or endoscopic discectomy (group F, n = 44) were retrospectively analyzed. X-ray, MRI, CT and clinical symptoms were recorded before operation and at the last follow-up (FU). The neurological function was originally evaluated by the Japanese Orthopaedic Association (JOA) scores. Radiological evaluation included the height of intervertebral space (HIS), intervertebral foramen height (FH), intervertebral foramen area (FA), lumbar lordosis (CA) and intervertebral disc degeneration Pfirrmann scores.Results:There was no significant difference in baseline characteristics, JOA improvement rate, reoperation rate and complications between the two groups. The age, average blood loss, average hospital stays and average operation time in group F were lower than those in group T. During the last FU, HIS, CA and FA decreased in both groups, and the changes in group T were more significant than those in group F (P < .05). There was no significant difference in FH changes between the two groups (P > .05).Conclusion:Both TLIF and endoscopic surgery can achieve good results in the treatment of LDH, but the risk of lumbar disc height loss and intervertebral foramina reduction in the adjacent segment after endoscopic surgery is lower.

Effect of Insertion Trajectory on the Compressive Performance of Intramedullary Devices for Subtalar Arthrodesis

Category: Hindfoot; Other Introduction/Purpose: Subtalar arthrodesis is a common procedure to treat hindfoot pathologies. Prior studies have evaluated the effect of screw trajectory on the initial compression of the subtalar joint. More recently, intramedullary (IM) devices using pseudoelastic NiTiNOL, developed for subtalar arthrodesis, can apply sustained dynamic compression (SDC). Headed screws' compression is achieved via the lag effect and is dependent upon its fixation in bone. The SDC device's compression is achieved by a manual mechanism; however, its fixation is dependent upon transverse screws. However, it is unknown how the trajectory of these devices in the subtalar joint alters compression. The aim of this study is to determine how the trajectory of both static compression screws and sustained dynamic compression devices affects joint compression. Methods: Based upon previously published methods, a synthetic talus and calcaneus were mechanically isolated in a custom fixture, and the compression measured via a load cell located in parallel to the subtalar construct. Static headed screws were inserted either in a parallel configuration across the posterior facet or in a diverging configuration across the posterior and anterior facets. A single IM SDC device was inserted across the posterior facet or the anterior facet and secured in the talus and calcaneus via transverse cortical screws. The resulting compression was measured in a thermal chamber at 37°C (n=8/group). Devices were inserted following the manufacturer's recommended instructions. Data was tested for normality using the Kolmogorov-Smirnov test. A one-way ANOVA was performed with a post-hoc Tukey test (α=0.05). All values are given as mean +- standard deviation. Results: The SDC device's compression was 398+-47N in the posterior facet and 417+-31N in the anterior facet (p=0.64). The screws' compression was 267+-31N in the parallel configuration and 269+-21N in the diverging configuration (p=0.99). The single SDC device, regardless of position, had significantly greater compression than the parallel or diverging headed screws configuration (p&lt;0.01). Conclusion: The SDC device's compression is not affected by insertion trajectory, thus allowing for surgeon preference in anatomic placement. The SDC device is able to generate more compression than the headed screws, regardless of trajectory or screw configuration.

Calcaneus Fracture Fixation: Assessing the Adequacy of the Sinus Tarsi Surgical Fixation Technique

Category: Trauma; Hindfoot Introduction/Purpose: Intra-articular calcaneus fractures are devastating injuries, and life-changing for patients that develop post-traumatic arthritis, a common outcome. Debate exists as to whether non-operative symptomatic management, or operative treatment, best manages these injuries, partially due to the difficulty of achieving anatomic subtalar joint reduction. Traditionally, a large, lateral extensile incision has been used, plagued with soft tissue complications quoted at rates upwards of 22%. A less invasive incision, the limited sinus tarsi approach (ST-a), has become more common, proposed to lower complication rates without compromising radiographic nor clinical outcomes. The primary purpose of this study was to objectively assess the adequacy of joint reduction along with the associated soft tissue complications using the ST-a and compare it to the standards of the lateral extensile incision. Methods: All calcaneus fractures fixated through the ST-a at our institution were reviewed between March 2017 and Jan 2020. Inclusion criteria included the presence of preoperative and post-operative X-rays and CT scans. Primary outcomes were radiographic measures, including Bohler's angle on X-ray, and the maximum summative step deformity at the posterior facet of the subtalar joint in all three planes on CT scan. Secondary clinical outcomes included soft tissue complications (infection, delayed wound healing) and the need for reoperation. Results: Thirty patients were included with an average age of 48.9 +- 13.9 (n=24 males, n=6 females) and Sanders classification of 2.8. Pre-operatively, the mean Bohler's angle and summative posterior facet step deformity were 5.8 +- 16.6° and 17.2 +- 9.3mm, respectively. These radiographic outcomes were significantly improved postoperatively to 27.2 +- 7.7° and 5.3 +- 2.9mm. Soft tissue complication rates were half that of the comparative extensile approach. Conclusion: Using the ST-a, radiographic joint reduction was acceptable compared to literature standards. There was subsequently a lower incidence of soft tissue complications than previously quoted for the lateral extensile approach. Although technically more demanding, the ST-a is a valuable method for the treatment of intra-articular calcaneal fractures and should be considered when planning operative management of intra-articular calcaneus fractures.

Evaluation of Automated Coverage and Distance Mapping Selections to Improve Reliability and Clinical Utility of 3D Weightbearing CT Assessments

Category: Hindfoot; Basic Sciences/Biologics; Other Introduction/Purpose: Progressive collapsing foot deformity (PCFD) is a complex three-dimensional (3D) deformity where adjacent structures may adopt subtle differences in positioning that result in increased contact or subluxation. Recent studies have highlighted the need for and utility of 3D analyses in PCFD using weightbearing CT (WBCT) and bone segmentation. Beyond the limitations of triplanar imaging, 3D distance and coverage mapping analyses have further highlighted key regional differences like sinus tarsi narrowing ahead of impingement and early middle facet uncoverage ahead of collapse. However, these analyses rely upon manual identification of subregions hindering the utility of 3D mapping clinically. The objective of this study was to compare an automated selection process with manual selections in the context of subtalar regional distance and coverage maps in PCFD. Methods: In this IRB-approved retrospective study, WBCT data of 20 consecutive patients with flexible PCFD and 10 controls were analyzed. Subregions of the peritalar surface (middle and posterior facets of the calcaneus and talus; sinus tarsi area) were manually selected by two experts on manually generated bone surfaces of all 30 feet. An automated algorithm for selecting coverage area was applied to identify the same regions on the semi-automatically generated bones (Figure). A 3D distance mapping (DM) technique was used to create coverage maps (CMs) across the entire peritalar surface where areas with distances less than 4mm were defined as covered. DM and CM percentages were compared using intra-class correlations and t-tests between PCFD and control groups. The Sørensen–Dice index, or Dice coefficient, was used for comparisons of selections on the semi-automated surfaces to evaluate reproducibility of expert selections. Results: The automated process produced identical selections resulting in perfect intra-method ICCs of 1.00 for all regions and Dice coefficients of 1.00. The average Dice coefficient for all manual selections was 0.903 (range: 0.865-0.935) indicating that observers were able to reliably select the same regions with 90% overlap. When assessing reliability of manual selections, intra- observer ICCs ranged from 0.41-0.92 while inter-observer ICCs ranged from 0.47-0.99 were found. Despite strong significant correlations, average coverage was significantly lower in the sinus tarsi region of the automated selections vs the manual selections (34.3+-16.8% vs 23.1+-12.7%, p&lt;0.005). However, mean distances in each region were not significantly different in the middle facet or the sinus tarsi regions (p=0.323, p=0.095, respectively). Conclusion: Understanding of the complex 3D deformities that constitute PCFD requires sensitive and reproducible measures. Fully automated 3D assessments of coverage and bone relations may have the potential to improve understanding of these deformities aiding in diagnosis, staging, and objective evaluation of treatment effects. Prior work with 3D coverage and distance maps specifically identified the middle facet and sinus tarsi regions as being of particular importance. Compared to manual selections, these regions were well identified by the automated process. This represents a step toward the goal of viable use of fully automated 3D coverage and distance mapping when evaluating PCFD patients.

Computational Modeling of Peritalar Joint Contact Mechanics in Flexible Flatfoot Deformity

Category: Hindfoot; Ankle; Ankle Arthritis Introduction/Purpose: Patients with longstanding progressive collapsing foot deformity (PCFD) often develop osteoarthritis of the peritalar (tibiotalar, subtalar, and talonavicular) joints, which can be symptomatic or can lead to fixed deformities that further complicate the treatment of other sequalae of the deformity (Mann, 1992). Degeneration and subsequent tearing of the arch supporting ligaments leads to altered joint contact mechanics which is a likely causative factor in the development of arthrosis (Hauser and Dolan, 2011). However, the initial effect of ligament tears on changes in joint contact mechanics in the collapsing foot has not been well characterized. The goal of this work was to compare the joint contact mechanics between the neutrally aligned and the flexible flatfoot (collapsed foot). Methods: A validated finite element model of the foot (Malakoutikhah et al., 2022a) was used to compare joint contact pressures between the normally aligned and the collapsed foot. The model of the foot constructed from CT scan images of a female cadaveric foot weighing 60 kg included all 28 bones, 72 ligaments, cartilage, and an encapsulating soft tissue. The model was loaded with 0.5 body weight applied at the center of mass and 0.25 body weight applied to the Achilles tendon simulating quiet stance. The collapsed foot model was created by simulated transection of the plantar fascia, long plantar, short plantar, deltoid, and spring ligaments and unloading of the posterior tibial tendon (Malakoutikhah et al., 2022b). The joint contact pressure maps were determined for both the neutrally aligned and collapsed foot models. The average and peak contact pressures were compared. Results: The peak contact pressures were increased in the tibiotalar and subtalar joints, but paradoxically were decreased in the talonavicular joint in the collapsed as compared to the neutrally aligned foot (Figure 1). The center of pressure was markedly different in all three joints between the neutral and collapsed foot conditions. Specifically, collapsing the foot caused two centers of the talonavicular joint peak pressure to shift towards the central region of the navicular bone, which were evenly distributed in the lateral and medial regions in the neutrally aligned foot. In the subtalar joint, the peak pressure that was uniformly distributed in the lateral and medial regions of the posterior facet in the neutrally aligned foot shifted towards the lateral region in the collapsed foot. Similarly, the peak contact pressure across the tibiotalar joint moved from the center to the lateral region when the foot collapsed. Conclusion: Degenerative tearing of the arch supporting ligaments in PCFD leads to an increase and laterization of the contact pressure in the tibiotalar and subtalar joints with a decrease of the pressure in the talonavicular joint. The paradoxical unloading of the talonavicular joint may be a result of the inability of the malaligned medial column to transmit force from the hindfoot to the forefoot. One implication of this work is that future treatments of PCFD might be directed towards normalizing contact pressure within the peritalar joints to prevent the progression of disease and the development of arthrosis.

Factors Related to the Inconstancy of Sustentaculum Tali Fragments in Intra-Articular Calcaneus Fractures

Category: Trauma Introduction/Purpose: Since intra-articular fractures are common in calcaneus fractures, anatomical reduction is important. Several ligaments such as spring ligament and deltoid ligament are attached to the Sustentaculum tali (ST). It is known that ST fragment is constant in calcaneus fracture. However, few studies have been reported to prove this. Therefore, we studied to establish criteria for the inconstancy of ST fragments through the analysis of computed tomography (CT) of the unaffected calcaneus, to confirm the prevalence of ST fragment inconstancy by applying these criteria, and to analyze the factors related to the inconstancy of the ST fragment. Methods: From 2012 to 2020, CT scans of calcaneus fractures of 122 patients (101 men and 21 women) were taken, and angulation and diastasis of ST fragment were measured in the semi-coronal plane. As a control, angulation and diastasis were measured in 62 unaffected calcaneus. After establishing criteria for the inconstancy of ST fragments, we evaluated the prevalence of ST fragment inconstancy. After, we analyzed related factors. Patient factors included age, BMI, smoking, and diabetes. Radiographic factors included the degree of comminution of the posterior facet, location of the outermost fracture line of the posterior facet, presence of an intra-articular fracture of the ST, and width of the ST fragment. Results: The upper limit of the 95% CI of angulation and diastasis was 7.58° and 2.51 mm, respectively. Based on these criteria, the inconstancy of the ST fragment was observed in 34.5%. The width of the ST fragment was significantly smaller in the inconstant group. Severe comminution of the posterior facet, intra-articular fracture of the ST, and diabetes were significantly higher in the inconstant group. The inconstancy of the ST fragment was significantly associated with the width of the ST fragment (p &lt; 0.001) (Table 1). Cut-off values for the inconstancy of the ST fragment were 20.5 mm for the width of the ST fragment. Conclusion: In intra-articular calcaneal fractures, ST fragment inconstancy was observed in 34.5%. The width of the ST fragment was significantly associated with the inconstancy of the ST fragment.

Minimally Invasive Posterior Facet Decortication and Fusion Using Navigated Robotic Guidance: Feasibility and Workflow Optimization.

Minimally invasive spine surgery reduces tissue dissection and retraction, decreasing the morbidity associated with traditional open spine surgery by decreasing blood loss, blood transfusion, complications, and pain. One of the key challenges with a minimally invasive approach is achieving consistent posterior fusion. Although advantageous in all fusion surgeries, solid posterior fusion is particularly important in spinal deformity, revisions, and fusions without anterior column support. A minimally invasive surgical approach accomplished without sacrificing the quality of the posterior fusion has the potential to decrease both short- and long-term complications compared to the traditional open techniques. Innovations in navigated and robotic-assisted spine surgery continue to address this need. In this article, we will outline the feasibility of achieving posterior facet fusion using the Mazor X Stealth Edition Robotic Guidance System.

The subtalar calcaneal angle: A novel angle for evaluation of displaced calcaneal fractures – A retrospective study

ObjectivesThe radiological measurement of the Böhler angle (BA) and the critical angle of Gissane (CAG) is used not only to diagnose and corroborate the suspicion of the presence of calcaneal fractures but also to assess the prognosis of different injury patterns and to evaluate the operative reduction of calcaneal fractures. Notwithstanding, many previous studies indicated the poor intra- and interobserver reproducibility of both angles. In this retrospective study, we present the subtalar calcaneal angle (SCA) as an additional diagnostic tool -to BA and CAG-which can be applied on pre- and postoperative radiographs to assess calcaneal fractures involving the posterior facet. DesignRetrospective Study. MethodsTwo retrospective groups were established, a ‘CF-group’ including radiographs of patients diagnosed with a calcaneal fracture and underwent operative treatment in the authors' traumatology department, and a ‘control group’ with 50 lateral calcaneal radiographs clear of skeletal lesions. Initially, the SCA, BA, and CAG were measured in both groups by three examiners. Those measurements were repeated one month later. The intra- and intertester reliabilities of all three angles were tested by determining the intraclass correlation coefficient (ICC). A paired t-test was used to prove the statistically significant difference between the SCA values for the pre- and postoperative groups, while the significant difference between the SCA values for the control and preoperative groups was tested through an independent-samples t-test. ResultsThe intra- and interobserver reliability of the SCA and the BA was in close proximity. The values of the SCA in both the control and postoperative groups were significantly different compared to the measurements of the preoperative group. The CAG showed poor intertester reliability. ConclusionThe subtalar calcaneal angle is a new instrument with proven reliability in estimating the prognosis of displaced calcaneal fractures and the postoperative alignment of the posterior facet. Level of clinical evidenceDiagnostic, Level III.

Study of morphological pattern of the talar articular facets in dry human calcanei and its clinical implications

Background: The calcaneum is longest and largest of all the tarsal bone. Morphology of the talar articular facets of calcanei is important for anatomy with respect to diagnosis and treatment of the injuries related to foot. Aims: This study was done to understand the variation in the morphology of talar articular facets on the superior surface of human calcanei and to study various shapes of these facets . Methods: 138 of adult dry calcanei 86 of right side and 52 of left side of unknown gender were taken from the museum of Department of Anatomy of Rohilkhand Medical College and Hospital, Bareilly and LBKMCH,Saharsa and evaluated one by one. Result: PatternI was 69.5% of the studied bones, Pattern II and Pattern III were 4.3% each, Pattern IV was 21.7%, Pattern V was not found. The anterior and middle articular facets were mostly oval in shape and that of posterior articular facet was oval and convex. The calcaneal length was recorded with the mean and SD of 6.9 ± 0. 65cms (left side) and 6.9 ± 0. 9cm (right side). The width was 4.0 ± 0.38 cm (left) ,4.1 ± 0.3 cm (right).