Hindfoot Alignment Angle Research Articles

Hindfoot Alignment in Pediatrics: The Relationship Between Hindfoot Moment Arm and Hindfoot Alignment Angle.

Various measurements are used to evaluate hindfoot alignment and determine appropriate treatment, though the best tool is not known. Few studies have examined the relationship between these measurements in pediatric patients. This study sought to compare Hindfoot Moment Arm (HMA) and Hindfoot Alignment Angle (HAA) in evaluation of pediatric hindfoot deformity. This was a retrospective cohort study of pediatric patients by age: school-aged (7 to 10 years old), preadolescents (11 to 14), and adolescents (15 to 18). A total of 10 males and 10 females were randomly selected for each cohort from patients with available hindfoot radiographs. HMA and HAA were measured by 2 independent reviewers. Pearson correlation of HMA and HAA was performed by age cohort. Multivariable linear regression was used to investigate the association of HMA and HAA adjusting for age, sex, height, and weight. Sixty participants were analyzed. Interrater reliability was found to be excellent for HMA and HAA (ICC=0.996 and 0.992, respectively). HMA was 8.7±9.4mm in school age, 5.7±6.7 mm in preadolescents, and 2.5±13.0 mm among adolescents (P=0.153). HAA was 6.3±9.7 degrees in school age, 6.7±8.6 degrees in preadolescents, and 6.0±14.5 degrees among adolescents (P=0.983). The Pearson correlation coefficient was 0.78 (CI: 0.51-0.91) for school-aged, 0.92 (CI: 0.81-0.97) for preadolescents, and 0.86 (CI: 0.67-0.94) for adolescents. Using multivariable regression, each degree increase in HAA, increased HMA by 0.77 mm. Age, height, and weight were not found to be independent predictors of HMA. HMA and HAA were both found to be reliable measurements across all age cohorts. When comparing across age cohorts, neither HMA nor HAA differed significantly (P=0.153 and 0.983, respectively). Furthermore, Pearson correlation demonstrated a linear relationship between HMA and HAA. When evaluating hindfoot deformity, surgeons may assess hindfoot alignment via either HMA or HAA regardless of patient age. The authors support the use of HMA for clinical and academic purposes as HMA is considerably simpler to measure. Level III.

Joint Preservation Surgery Using Supramalleolar Osteotomy Combined with Posterior Tibial Tendon Release and Lateral Ligament Augmentation in Advanced Varus Ankle Arthritis.

Background: Recent studies utilizing weight-bearing computed tomography have identified abnormal internal rotation of the talus in advanced varus ankle arthritis (VAA) with a large talar tilt (TT), influenced by the posterior tibial tendon (PTT). This study aimed to evaluate the clinical and radiographic results of supramalleolar osteotomy (SMO) combined with PTT release and lateral ligament augmentation for VAA with a large TT. Methods: From January 2015 to September 2018, 15 patients with VAA and a large TT (greater than 5°) underwent SMO combined with PTT release. Clinical results, including visual analog scale (VAS) for pain, American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, and ankle osteoarthritis scale (AOS), were assessed. Radiographic results were assessed with various parameters, including medial distal tibial angle (MDTA), anterior distal tibial angle (ADTA), talar tilt (TT), talus center migration (TCM), Meary angle, hindfoot alignment angle (HAA), and hindfoot moment arm (HMA) on foot and ankle weight-bearing radiographs. Clinical and radiographic results were evaluated preoperatively and at the last follow-up. Results: VAS, AOFAS ankle-hindfoot score, and AOS improved significantly from 7.5, 54.4, and 72.6 preoperatively to 3.1, 82.5, and 34.5 postoperatively, respectively. All radiographic parameters exhibited significant changes postoperatively, with the exception of the Meary angle, which demonstrated no significant change. Four patients exhibited improvement in radiographic stage postoperatively; however, average radiographic stage did not significantly improve postoperatively in all patients. One patient progressed to end-stage arthritis postoperatively, necessitating additional ankle arthrodesis. Conclusions: In conclusion, lengthening and lateral ligament augmentation combined with bony realignment procedures may be a reasonable option for treating VAA with a large TT greater that 5°.

Hindfoot Alignment in Flexible Cavovarus Deformity Under Orthostatic and Coleman Block Test Positions: A Weightbearing Computed Tomography Study.

Flexible cavovarus deformity is prevalent and the Coleman block test is frequently used to assess the first ray plantarflexion malpositioning in the overall deformity as well as the flexibility of the hindfoot. The objective was to assess and compare the weightbearing computed tomography (WBCT) 3-dimensional (3D) changes in clinical and bone alignment in flexible cavovarus deformity patients when performing the Coleman block test when compared to normal standing position and to controls. Twenty patients (40 feet) with flexible cavovarus deformity and 20 volunteer controls (40 feet) with normal foot alignment underwent WBCT imaging of the foot and ankle. Cavovarus patients were assessed in normal orthostatic and Coleman block test positions. Foot and ankle offset (FAO), hindfoot alignment angle (HAA), talocalcaneal angle (TCA), subtalar vertical angle (SVA) and talonavicular coverage angle (TNCA) and a CT-simulated soft tissue envelope image, WBCT clinical hindfoot alignment angle (WBCT-CHAA), were evaluated by 2 readers. Measurements were compared between cavovarus nonstressed and stressed positions and to controls. P values of .05 or less were considered significant. The intra- and interobserver intraclass correlation coefficient were good or excellent for all WBCT measurements. Cavovarus patients demonstrated significant correction of WBCT-CHAA (9.7 ± 0.4 degrees), FAO (2.6 ± 0.4%), and TNCA (8.8 ± 1.8 degrees) when performing the Coleman block test (all P values <.0001). However, WBCT-CHAA and FAO measurements were still residually deformed and significantly different from controls (P values of .001 and <.0001, respectively). TNCA values corrected to values similar to healthy controls (P = .29). No differences were observed in cavovarus patients during Coleman block test for the coronal measures: HAA, TCA, and SVA measurements. In this study, we observed improvement in the overall 3D WBCT alignment (FAO), axial plane adduction deformity (TNCA), as well as CT simulated clinical hindfoot alignment (WBCT-CHAA) in flexible cavovarus deformity patients when performing a Coleman block test. However, we did not find improvement in measures of coronal alignment of the hindfoot, indicating continued varus positioning of the hindfoot in these patients.

Clubfoot Correction with Ponseti Technique: Three-Dimensional Alignment Analysis and Residual Adult Deformity Effects on Patient-Reported Outcomes

Introduction/Purpose: Few studies have assessed the long-term outcomes of the Ponseti technique and none have utilized 3- dimensional weightbearing analysis. The goal of this study was to understand how potential residual 3D deformities and abnormalities influence patient reported outcomes (PROs). This was accomplished by assessing anatomical foot and ankle alignment in adult clubfoot patients treated with the Ponseti method using 3D weightbearing CT (WBCT) imaging and then correlating residual foot and ankle malalignment with PROs. Methods: There were 37 consecutive patients (57 feet) included and 14 volunteers healthy controls (28 feet) included in this study. Every participant was evaluated using a WBCT (HiRise©) in a bipedal standing position. From these scans Cavus, Adductus, and Varus components were evaluated using multiple 3D measurements calculated using the semi-automatic segmentation software Bonelogic®. Specific Cavus related measurements included sagittal talus-first metatarsal angle and the calcaneal inclination angle. Varus related measurements included talocalcaneal angle in both the sagittal and axial planes as well as the hindfoot moment arm and the hindfoot alignment angle. Adductus deformity was evaluated using talonavicular coverage angle. These measurements were then correlated with patient reported outcome surveys, which included Visual Acuity Scale for pain, PROMIS general health, PROMIS physical function, PROMIS pain interference, pain catastrophic scale, and European foot and ankle society score. Results: There was no significant overall residual 3D-deformity observed in clubfoot patients when compared to controls, with similar FAO measurements observed between the groups, clubfoot=2.63% (95%CI=1.41%-3.85%) and control=3.2% (CI=1.6%- 4.8%,P=0.58). The sagittal talus-first-metatarsal in the clubfoot-patients had a mean-value of -0.12° compared to the controls, −5.2°. Clubfoot patients also had a decreased calcaneal-inclination-angle relative to the controls, 13.01° and 21.5° respectively. Talocalcaneal-angle for clubfoot patients in both the sagittal-plane,44.28°, and axial-plane, 17.74°, were reduced compared to the controls, 57.51° and 25.78°. Talonavicular-coverage-angle in the clubfoot-group (18.63°) was less than the controls (29.19°). Talus- first-metatarsal-angle in the sagittal-plane was significantly correlated with VAS-scores (RSquare=0.19,P=0.0118) and the EFAS- Score (RSquare=0.27,P=0.0025). Talocalcaneal-angle in the sagittal plane was also significantly correlated with the PROMIS-Pain- Interference-score (P=0.038) and PROMIS-Physical-Function-score (RSquare=0.32,P=0.0007). Conclusion: The Ponseti technique is an effective nonsurgical treatment for the overall three-dimensional foot and ankle alignment of Clubfoot. While mild, but statistically significant residual Varus and Adductus deformities were observed in adult clubfoot patients, the overall 3D alignment (FAO) was found to be similar between clubfoot patients and controls. These findings highlight the efficacy of the Ponseti technique and potentially explain the overall good PROs. The results of this study could potentially provide insight into treatment targets that may be applied to help optimize patient outcomes when treating children with Clubfoot in the future. The Ponseti technique is an effective nonsurgical treatment for Clubfoot's overall three-dimensional foot and ankle alignment. While mild, but statistically significant residual Varus and Adductus deformities were observed in adult clubfoot patients, the overall 3D alignment (FAO) was found to be similar between clubfoot patients and controls. These findings highlight the efficacy of the Ponseti technique and potentially explain the overall good PROs. The results of this study could potentially provide insight into treatment targets that may be applied to help optimize patient outcomes when treating children with Clubfoot in the future.

Isolated Subtalar Repositional Arthrodesis Compared With Triple Arthrodesis for the Treatment of Progressive Collapsing Foot Deformity

The optimal extent of arthrodesis for severe and rigid progressive collapsing foot deformity is controversial. Traditionally, triple arthrodesis has been recommended; however, good results have been reported using subtalar arthrodesis only. We compared the results of triple arthrodesis and isolated subtalar repositional arthrodesis. A total of 22 symptomatic feet were evaluated retrospectively. Isolated subtalar repositional arthrodesis was performed in 13 cases (the subtalar group) and double or triple arthrodesis in 9 cases (the triple group). Various radiographic variables for assessing flatfoot and osteoarthritic changes in ankle and tarsal joints were measured and compared between the 2 groups at 3 time points: preoperatively, 3 months postoperatively, and 4 y postoperatively. Additionally, we analyzed various factors that affect postoperative valgus talar tilt in the ankle joint, which has been associated with poor prognosis. There were no differences in preoperative demographic data and the severity of the disease between the 2 groups; both groups showed improvement in radiographic parameters postoperatively compared with preoperative results. With the numbers available, no significant differences could be detected in postoperative radiographic measurements between the 2 groups. Of all the variables analyzed, postoperative hindfoot alignment angle was associated with postoperative talar tilt development. Additionally, postoperative talar tilt was observed more in triple group than in subtalar group. In conclusion, isolated subtalar repositional arthrodesis is an effective procedure to correct advanced progressive collapsing foot deformity. In addition, Chorpart joint arthrodesis with improper position can cause valgus talar tilt in the ankle joint.

Preoperative Hindfoot Alignment and Outcomes After High Tibial Osteotomy for Varus Knee Osteoarthritis: We Walk on Our Heel, Not Our Ankle.

This article was updated on May 15, 2024 because of previous errors, which were discovered after the preliminary version of the article was posted online. On page 898, in the section entitled "Materials and Methods," the sentence that had read "The WBL ratio of the knee joint was defined as the point where the GA or MA passed through the width of the tibia and intersected a line from the center of the femoral head to the center of the calcaneus (for the GA) or talus (for the MA), with the medial edge defined as 0% and the lateral edge as 100%." now reads "The WBL ratio of the knee joint was defined as the point where the GA or MA passed through the width of the tibia and intersected a line from the center of the femoral head to the lowest point of the calcaneus (for the GA) or the center of the talus (for the MA), with the medial edge defined as 0% and the lateral edge as 100%." Likewise, in the legend for Figure 3 on page 899, the sentence that had read "Depiction of the ground mechanical axis (GA), defined as the line (represented by the solid red line) from the center of the femoral head to the ground reaction point at the center of the calcaneus, passing lateral to the traditional mechanical axis (MA; represented by the dashed red line)." now reads "Depiction of the ground mechanical axis (GA), defined as the line (represented by the solid red line) from the center of the femoral head to the ground reaction point at the lowest point of the calcaneus, passing lateral to the traditional mechanical axis (MA; represented by the dashed red line)." Finally, on page 903, "HKA" was changed to "HKA angle" in Table III. The hip-to-calcaneus axis, previously known as the ground mechanical axis (GA), ideally passes through the center of the knee joint in the native knee. The aim of this study was to elucidate, with use of hip-to-calcaneus radiographs, changes in knee and hindfoot alignment and changes in outcomes following high tibial osteotomy (HTO). We reviewed the records for 128 patients who underwent HTO between 2018 and 2020. Patients were stratified into 2 groups, a hindfoot valgus group (n = 94) and a hindfoot varus group (n = 34), on the basis of their preoperative hindfoot alignment. The hindfoot alignment was evaluated with use of the hindfoot alignment angle (HAA). To evaluate lower-limb alignment, full-length standing posteroanterior hip-to-calcaneus radiographs were utilized to measure 4 radiographic parameters preoperatively and 2 years postoperatively: the hip-knee-ankle (HKA) angle, hip-knee-calcaneus (HKC) angle, and the weight-bearing line (WBL) ratios of the mechanical axis (MA) and GA. The mean HAA improved significantly from 5.1° valgus preoperatively to 1.9° valgus postoperatively in the hindfoot valgus group (p < 0.001). In contrast, in the hindfoot varus group, the HAA showed no meaningful improvement in the coronal alignment of the hindfoot following HTO (p = 0.236). The postoperative mean HKC angle in the hindfoot varus group was 2° more varus than that in the hindfoot valgus group (1.0° versus 3.0°; p = 0.001), and the GA in the hindfoot varus group passed across the knee 8.0% more medially than that in the hindfoot valgus group (55% versus 63% from the most medial to the most lateral part of the tibial plateau). The hindfoot varus group had worse postoperative clinical outcomes than the hindfoot valgus group in terms of the mean Knee injury and Osteoarthritis Outcome Score for pain and American Orthopaedic Foot & Ankle Society Ankle-Hindfoot Score. Although our findings did not provide sufficient evidence to establish clinically relevant differences between the groups, they indicated that the group with a preoperative fixed hindfoot varus deformity had a higher rate of undercorrection and worse clinical outcomes, especially pain, following HTO. Therefore, modification of the procedure to shift the GA more laterally may be required for these patients. Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

A Novel Technique of Medial Displacement Calcaneal Osteotomy Using the Intramedullary Fixation of a Conventional Low-Profile Locking Wedge Plate.

Postoperative heel pain arising from prominent screw heads is a common complication following medial displacement calcaneal osteotomy (MDCO). This study aims to present the clinicoradiographic outcomes of a novel MDCO technique, wherein intramedullary fixation of a conventional low-profile locking wedge plate is employed. A retrospective analysis, involving a comparison of clinical and radiographic parameters among consecutive patients who underwent MDCO was conducted. The patients were subjected to either intramedullary wedge plate fixation through the osteotomy site (IWPF group, n = 45 cases) or conventional cannulated screw fixation from the heel (CCSF group, n = 51 cases). Radiographic evaluation included measurement of hindfoot alignment angle, alignment ratio, and moment arm. Clinical outcomes were measured with the American Orthopaedic Foot & Ankle Society ankle-hindfoot score, and the Foot and Ankle Ability Measure (FAAM) activities of daily living and sports subscales, before and at 6, 12, and ≥24 months postoperatively. The presence of heel pain was evaluated at the postoperative 6 and 12 months in both groups. For both groups, a marked enhancement in all 3 radiographic parameters was observed. The extent of correction for all clinicoradiographic parameters demonstrated no statistically significant divergence between the 2 groups. However, the FAAM-Sports scores at the 6-month postoperative juncture exhibited a significant elevation in the IWPF group relative to the CCSF group. Importantly, no patient reported heel pain at postoperative 6 and 12 months in the IWPF group whereas the rates of patients having heel pain at postoperative 6 and 12 months were 56.8% (29 cases) and 33.3% (17 cases), respectively, in the CCSF group. Both techniques yield analogous postoperative clinical and radiographic enhancements. However, the utilization of IWPF promotes a swifter clinical improvement with respect to sports activities when juxtaposed with the CCSF from the calcaneal tuberosity. Level III, retrospective comparative study.

Combined Deltoid and Spring Ligament Reconstruction Using the Quadrangular Construct: Our Experience and Review of the Literature.

Background A combined reconstruction of chronic deltoid and spring ligament insufficiency is uncommon. Our study aims to share our experience in treating post-traumatic, chronic deltoid, and spring ligament insufficiency using the "quadrangular construct" technique. Material and methods Five patients who had post-traumatic combined deltoid and spring ligament insufficiency were included in the study. All patients reported a "giving-way" sensation.Preoperatively, each patient underwent weight-bearing radiographs of the ankle and foot. The talo-first metatarsal angle and hindfoot alignment angle were noted. The superficial deltoid ligament was repaired using a suture anchor augmented with Internal BraceTM (Arthrex, Naples, USA) FiberTape® to form a quadrangular construct that anatomically mimics various components of the deltoid-spring ligament complex. Due to the associated excessive heel valgus, three patients also underwent medial displacement calcaneum osteotomy. Additionally, one patient required lateral ligament repair, and another patient required syndesmotic stabilization. TheAmerican Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score was used to evaluate preoperative and postoperative ankle function. Results All five patients were followed up for a mean of 20 months (range: 12-24 months). The mean preoperative talo-first metatarsal angle improved from 8.46 degrees to 4.84 degrees. The preoperative mean hindfoot alignment angle was reduced from 10.9 to 5.76 degrees postoperatively. One patient had irritation due to the anchor, which needed removal after one year. Postoperatively, no patients re-experienced the feeling of "giving way". The AOFAS scores postoperatively showed two patients as excellent, two as good, and one as fair. All the patients returned to their pre-injury work. Conclusion We have developed a technique for combined deltoid and spring ligament reconstruction using a quadrangular construct. This technique helps to restore anatomical stability, is safe, easily reproducible, and has shown positive short-term results in follow-up. The level of evidence is one of the methods used to categorize the quality and reliability of research, and our study falls under the category of level IV evidence.

Pathophysiology of abnormal compensation ability of the subtalar joint in the varus knee

BackgroundIn recent years, the involvement of the compensation ability of the subtalar joint in lower extremity alignment has been reported. We previously showed that hindfoot alignment angle (HAA) is an indicator of compensation ability of the subtalar joint. The abnormal compensation ability of the subtalar joint was defined by the mobility of the subtalar joint, and evaluation of the mobility of the subtalar joint may help to further clarify the pathophysiology of abnormal compensation ability of the subtalar joint. This study was performed to evaluate the mobility of the subtalar joint and clarify the pathophysiology of abnormal compensation ability of the subtalar joint in the varus knee. MethodsSeventy-two knees of 72 patients aged ≥40 years with varus knee were included in this study. Preoperative radiographs were used for measurement of this study parameters. Based on our previous study, we defined HAA of ≥15.9°as abnormal compensation ability of the subtalar joint. The patients were divided into an abnormal group (A-group) and normal group (N-group). All measurement parameters were compared between the groups, and correlations between the HAA and each measurement parameter were analyzed. ResultsThe weight-bearing hindfoot angle (WBHA) (p < 0.001) and non-weight-bearing hindfoot angle (non-WBHA) (p = 0.003), were significantly greater in the A-group than in the N-group. Conversely, the ratio of change in hindfoot alignment (p = 0.006), were significantly smaller in the A-group than in the N-group. The HAA was positively correlated with WBHA (r = 0.66) and non-WBHA (r = 0.43) and negatively correlated with the ratio of change in hindfoot alignment (r = −0.32). ConclusionsThe pathophysiology of abnormal compensation ability of the subtalar joint in the varus knee is thought to involve a state of increased valgus of hindfoot alignment and an inability to move into normal hindfoot alignment. Level of evidenceLevel Ⅲ, retrospective study.

Intraoperative assessment of hindfoot alignment using C-arm fluoroscopy

BackgroundHindfoot malalignment can cause various foot and ankle problems. For better surgical performance and correction of hindfoot malalignments, reliable intraoperative determination of hindfoot alignment is essential. However, there is no standard method for the intraoperative assessment of hindfoot alignment. We devised an intraoperative modified Méary posteroanterior (IOPPA) view to assess intraoperative hindfoot alignment. This study aimed to compare this intraoperative method with other radiographic hindfoot alignment measurements. MethodsThirty-seven patients (47 feet) with various foot and ankle conditions scheduled to undergo surgery were prospectively recruited. Before surgery, the Saltzman, long axial, and modified Méary views were taken in a controlled and standardized fashion. IOPPA views were obtained under simulated weight bearing conditions using C-arm fluoroscopy in the operating room before surgery. The relationship between the IOPPA view and the three radiographic hindfoot alignments was evaluated using Pearson's correlation. ResultsThe mean hindfoot alignment angle was varus 3.50° (CI, varus 1.91 to 5.08) on the Saltzman view, varus 2.00° (CI, varus 0.60 to 3.39) on the long axial view, varus 0.13° (CI, valgus 1.41 to varus 1.67) on the modified Méary view, and varus 1.32° (CI, valgus 0.02 to varus 2.65) on IOPPA view. The IOPPA view and the three other hindfoot alignment views were found to be significantly correlated (r = 0.60 for the Saltzman view, r = 0.50 for the long axial view, r = 0.71 for the modified Méary view, P < .05). The intraobserver ICC (Intraclass Correlation Coefficient) value was 0.974 and interobserver ICC (Intraclass Correlation Coefficient) value was 0.988 for the IOPPA view (P < .001). ConclusionThere was a statistically significant correlation between the IOPPA view and the other three hindfoot alignment views. We also found that interobserver and intraobserver ICC values were excellent. This study proposes that the IOPPA view can be used as a reliable intraoperative assessment tool for hindfoot alignment. Level of evidenceProspective study.

Comparation of outcomes of iliac crest bone graft and accessory navicular bone graft in the Cotton osteotomy for pediatric and adolescent flexible flatfoot

Objective: To compare the outcomes between iliac crest and accessory navicular as different bone grafts in the Cotton osteotomy in the treatment of pediatric flexible flatfoot deformity. Methods: A retrospective cohort study. The clinical data of pediatric flexible flatfoot patients with symptomatic accessory navicular received operations from July 2018 to March 2022 in Beijing Tongren Hospital were retrospectively analyzed. All the patients were treated with Cotton osteotomy. According to the different sources of bone grafting in Cotton osteotomy, the patients were divided into iliac crest group and accessory navicular group. There were 12 patients (19 feet) in iliac crest group, including 9 males and 3 females with a median age M(Q1, Q3) of 11(11, 12) years and were followed-up for 36(6, 48) months. There were 9 patients (16 feet) in accessory navicular group, including 6 males and 3 females, with a median age M(Q1, Q3) of 11(11, 11) years and were followed-up for 12(6, 17) months. Radiographic evaluations were reviewed and compared between the two groups before surgical treatment and at final follow-up, included talo-1st metatarsal angle (T1MT), talonavicular coverage angle (TNCA), talocalcaneal angle (TCA) in weight bearing anteroposterior view, and Meary angle, calcaneal Pitch angle, Kite angle, cuneiform articular angle (CAA) in weight bearing lateral view, and hindfoot alignment angle (HAA) in calcaneal long axial view. Functional scores included American Orthopedic Foot and Ankle Society (AOFAS), visual analog scale (VAS), and Maryland scores were recorded and compared before and after the operation. The complications were also recorded. Results: Total of 21 patients were successfully followed in this study. The radiographic measurements in the two groups, such as T1MT, TNCA, Meary angle, Pitch angle, Kite angle, CAA, HAA, were all significantly improved at the last follow-up when compared with those before the surgery (all P<0.05); and the AOFAS, VAS, Maryland scores in both groups were all improved after the surgery (all P<0.05). There was a significant difference in CAA alteration (∆CAA) after the operation between the two groups, the ∆CAA in iliac crest group and the accessory navicular group was 6.0°±2.6° and 4.3°±1.3°, respectively (P=0.017). There was no significant differences in the improvement of other radiographic measurements between the two groups (all P>0.05). All the patients had a successful bone union. Two patients had donor site pain in the iliac crest group and were treated conservatively. Conclusion: Compared with iliac crest bone graft, accessory navicular bone graft could achieve comparable outcomes in radiographic measurements and functional scores in the treatment of pediatric flexible flatfoot with accessory navicular pain.

Evaluation of Hindfoot Alignment on Lateral Weightbearing x-rays: A Novel Prospective In Vivo Study

Category: Hindfoot; Midfoot/Forefoot Introduction/Purpose: In clinical practice and research, there are several scenarios when a hindfoot alignment view weightbearing XR is not obtained whether as a result of a lack of resources, technology, in retrospective studies when a hindfoot view was not obtained, as well as in many practices where a hindfoot view XR is not considered a routine examination for foot and ankle disorders. A lateral weightbearing radiograph however is almost routinely obtained, and the goal of this study was to correlate the hindfoot alignment angle with measurements on lateral weightbearing images. Methods: Four volunteers (8 feet) with flexible feet and ankles and no symptoms, nor significant trauma &amp; surgical history in their lower limbs were recruited for this study. A portable fluoroscopy machine (Smart C, Turner Imaging, Salt Lake City, USA) was used for imaging. The participant was asked to stand on different custom wooden wedges with the angle changed every 5 degrees from 30 degrees of varus to 30 degrees of valgus and a weightbearing lateral image was taken for each position. The hindfoot alignment was measured using a skin marker which had been drawn prior to initiation of the imaging, and the angular changes of the hindfoot was measured with the placement of each wedge placed. All standardized measurements of the midfoot and hindfoot were obtained on the lateral images. Results: With the hindfoot positional changes between 30o of varus to 30o of valgus, there was a gradual measurable change in the subtalar joint, with corresponding changes in the midfoot and hindfoot. There was a significant linear correlation between the hindfoot alignment angle and all radiographic parameters on lateral images. When the hindfoot alignment angle increased by 1 degree in the valgus direction, there was 0.49o decrease in the pitch angle, 0.58o of decrease in the middle vs posterior facet angle, 0.06o of decrease in the proximal cuneiform/cuboid height, 0.40o of decrease in the proximal cuneiform/5th Metatarsal height, 0.40o of increase in the fifth metatarsal/cuboid height, 0.009o of increase in the sinus tarsi/lateral process height, and 0.015o increase in Cuboid/Anterior Process Height. (Figure 1) Conclusion: The lateral weightbearing XR can be used to predict the status of the hindfoot alignment, and this study has proven that this can be none not only qualitatively but also quantitatively. This novel research can provide our colleagues with linear regression equations to correlate the lateral imaging metrics with the hindfoot alignment angle. Further study with a larger sample size and participants with different types of hindfoot deformities is needed to help develop an algorithm that would help both clinical practice and research.

Effect of Medial Closing Wedge Distal Femoral Varization Osteotomy on Coronal Ankle and Hindfoot Alignment

Category: Hindfoot; Ankle Introduction/Purpose: To date, only a few studies have reported postoperative changes in coronal ankle alignment after valgus knee correction through Medial Closing Wedge Distal Femoral Varization Osteotomy (MCWDFO). This study aimed to measure the changes of MCWDFO on coronal ankle and hindfoot alignment. Methods: We retrospectively reviewed the radiographic findings of 27 consecutive patients (34 cases) with knee valgus malalignment who underwent MCWDFO for either lateral knee joint osteoarthritis (OA) or recurrent patellar subluxation/dislocation (RPD) . Several radiographic parameters were measured and compared based on the reason for operation, followed by the status of preoperative hindfoot alignment (hindfoot alignment angle [HAA] &gt; 4°, varus; -4° HAA 4°, neutral; HAA &lt; -4°, valgus) in each group. Results: Overall, pre- and postoperative hindfoot alignments were within the neutral alignment range and were not significantly changed after the operation (P &gt; 0.05). Nineteen cases were for lateral knee OA and 15 were for RPD, respectively. In both groups, preoperative neutral hindfoot alignments accounted for the largest portion (52.6% in the lateral OA group; 80.0% in the RPD group). Postoperatively, regardless of the reason for operation, hindfoot alignments changed toward the neutral range in all subgroups (i.e., no changes in the preoperative neutral group; increased in the valgus group; decreased in the varus group). Conclusion: We recommend that surgeons leave the hindfoot untouched when they plan the MCWDFO to correct knee joint valgus malalignment concomitant with hindfoot valgus or varus deviation as the hindfoot malalignment appears to change towards neutral range postoperatively.

The Variation Between Unilateral and Bilateral Weight Bearing in Hindfoot Alignment Evaluation. Part I: A Prospective In Vivo Radiographic Study

Category: Hindfoot; Midfoot/Forefoot Introduction/Purpose: When weight bearing radiographs are taken, the patient is frequently asked to stand on the foot being examined with the other foot lifted off the floor. We have found however that alignments of the hind and midfoot change when bearing weight switches from bilateral to unilateral standing. This study investigated the possible differences in hindfoot alignments between unilateral and bilateral weight bearing using radiographical evaluation. Methods: Eight flexible feet without symptoms symptoms, nor significant trauma &amp; surgical history in their lower limbs were recruited for this study. A portable fluoroscopy machine (Smart C, Turner Imaging, Salt Lake City, USA) was used to take weightbearing lateral views. The patient first stood on both feet with the non-examined foot standing outside of the collimator but bearing weight evenly (Figure 1), and then lifted the non-examined foot off the floor when the lateral XR image was taken for the examined foot. Hindfoot alignment in both positions was reflected by measuring the angle between the long axes of the proximal and distal portions of the Achilles tendon on the skin using the subtalar joint line as the intersection. On lateral XRs, various parameters were measured to reflect the subtalar joint alignment, the position of the calcaneus with inversion and eversion of the hindfoot, and the lateral and medial arch heights. Results: From bearing weight on two feet (bilaterally) to one foot (unilaterally), the Hindfoot Alignment Angle (Achilles) increased (6.23 to 11.21 degrees), the Calcaneal Pitch Angle decreased (22.06 to 19.22 degrees), the Middle vs Posterior Facets Angle decreased (166.46 to 160.74 degrees), and the 5th metatarsal/cuboid height decreased (0.73 to 0.67) all significant changes (p &lt; 0.05). All of these represented a pronation movement in the mid and hindfoot, ie, valgus tilt/eversion of the calcaneus, decreased sinus tarsi opening, and reduced lateral arch height. In this small cohort, these differences were more obvious in the feet that were either slightly flat or cavus shaped (Figure 1, Table 1, and 2) than in feet with a more neutral alignment. Conclusion: The hindfoot and midfoot are more pronated in unilateral weightbearing than in bilateral weightbearing which may mask the severity of the deformity in a flexible cavovarus foot, but increase that in a flexible flatfoot. Modification of the traditionally used unilateral weightbearing position in obtaining clinical radiographs should be considered. Bilateral WBCT scans may be a better alternative, taking advantage of allowing both feet to stand in the most natural position without one foot blocking the other during the radiographic imaging.

Weight-bearing line at the ankle joint level shifted laterally after total knee arthroplasty for varus knee osteoarthritis: Evaluation of the hip-to-calcaneus line

BackgroundFew studies have comprehensively examined how alignment beyond the ankle joint changes after Total knee arthroplasty (TKA). This retrospective study aimed to answer the questions: (1) do the radiological parameters beyond the ankle joint, including the weight-bearing line at the ankle joint level, change after TKA in varus knee osteoarthritis? (2) Does the lower extremity alignment correlate with alignment beyond the ankle joint? HypothesisOur hypothesis was that TKA altered the radiological parameters beyond the ankle, which correlated with the lower extremity alignment. Patients and methodsThis retrospective study included 67 patients who underwent mechanically aligned TKA for varus knee osteoarthritis. The hip-knee-ankle angle (HKA), tibial plafond inclination angle (TPIA), hindfoot alignment angle (HA), talar tilt (TT), and weight-bearing line at the ankle joint level (mechanical ankle joint axis point [MAJAP]) were measured using radiographs taken before and 6 months after TKA; each parameter was compared between the two time points. The correlations between HKA and other parameters were examined preoperatively and postoperatively. ResultsThe mean HKA, TPIA, HA, TT, and MAJAP changed significantly after TKA from 15.0±6.1̊ to 2.6̊±3.5̊, from 10.8̊±5.7̊ to 4.7̊±3.9̊, from 2.3̊±5.5̊ to –2.5̊±4.5̊, from 0.2̊±1.3̊ to –0.5̊±1.4̊, and from 29.3±23.3 to 54.3±20.6, respectively. Correlations were noted between the preoperative HKA and the preoperative TPIA (r=0.58), HA (r=0.36), and MAJAP (r=–0.59), and between the postoperative HKA and the postoperative TPIA (r=0.54) and MAJAP (r=–0.38). DiscussionTKA for varus knee osteoarthritis altered radiological parameters beyond the ankle, with the weight-bearing line at the ankle joint level passing more laterally. The weight-bearing line at the ankle joint level was correlated with lower extremity alignment both preoperatively and postoperatively. Level of evidenceIV; single-centre retrospective observational study.

Effectiveness and risk factors of supramalleolar osteotomy in treatment of varus-type ankle arthritis

To assess the effectiveness of supramalleolar osteotomy (SMOT) as a therapeutic intervention for varus-type ankle arthritis, while also examining the associated risk factors that may contribute to treatment failure. The clinical data of 82 patients (89 feet) diagnosed with varus-type ankle arthritis and treated with SMOT between January 2016 and December 2020 were retrospectively analyzed. The patient cohort consisted of 34 males with 38 feet and 48 females with 51 feet, with the mean age of 54.3 years (range, 43-72 years). The average body mass index was 24.43 kg/m 2 (range, 20.43-30.15 kg/m 2). The preoperative tibial anterior surface angle (TAS) ranged from 77.6° to 88.4°, with a mean of 84.4°. The modified Takakura stage was used to classify the severity of the condition, with 9 feet in stage Ⅱ, 41 feet in stage Ⅲa, and 39 feet in stage Ⅲb. Clinical functional assessment was conducted using the Maryland sore, visual analogue scale (VAS) score, and psychological and physical scores in Health Survey 12-item Short From (SF-12). Radiology evaluations include TAS, talar tilt (TT), tibiocrural angle (TC), tibial medial malleolars (TMM), tibiocrural distance (TCD), tibial lateral surface angle (TLS), and hindfoot alignment angle (HAA). The results of clinical failure, functional failure, and radiology failure were statistically analyzed, and the related risk factors were analyzed. The operation time ranged from 45 to 88 minutes, with an average of 62.2 minutes. No complication such as fractures and neurovascular injuries was found during operation. There were 7 feet of poor healing of the medial incision; 9 pin tract infections occurred in 6 feet using external fixator; there were 20 cases of allograft and 3 cases of autograft with radiographic bone resorption. Except for 1 foot of severe infection treated with bone cement, the remaining 88 feet were primary healing, and the healing area was more than 80%. All patients were followed up 24-82 months, with an average of 50.2 months. Maryland score, VAS score, SF-12 psychological and physiological scores, and TAS, TC, TLS, TCD, TT, TMM, HAA, and Takakura stage were significantly improved at last follow-up ( P<0.05). Postoperative clinical failure occurred in 13 feet, functional failure in 15 feet, and radiology failure in 23 feet. Univariate analysis showed that obesity, TT>10°, and Takakura stage Ⅲb were risk factors for clinical failure, HAA≥15° and Takakura stage Ⅲb were risk factors for functional failure, and TT>10° was risk factor for radiographic failure ( P<0.05). Further logistic regression analysis showed that TT>10°, HAA≥15°, and TT>10° were risk factors for clinical failure, functional failure, and radiographic failure, respectively ( P<0.05). SMOT is effective in the mid- and long-term in the treatment of varus-type ankle arthritis, but it should be used with caution in patients with obesity, severe hindfoot varus, severe talus tilt, and preoperative Takakura stage Ⅲb.

Short-term effectiveness of INBONE TM Ⅱ total ankle prosthesis arthroplasty in the treatment of moderate to severe varus-type ankle arthritis

To investigate the short-term effectiveness of INBONE TM Ⅱ total ankle prosthesis arthroplasty in the treatment of moderate to severe varus-type ankle arthritis. The clinical and radiographic data of patients with moderate to severe varus-type ankle arthritis, who were admitted between May 2017 and November 2021 and treated with total ankle arthroplasty (TAA) using INBONE TM Ⅱ prosthesis, was retrospectively analyzed. A total of 58 patients (58 ankles) met the selection criteria and were included in the study. Among them, there were 24 males and 34 females, with an average age of 62.6 years (range, 41-85 years). According to the preoperative tibiotalar angle (TTA), the patients were divided into a moderate varus group (group A, TTA 5°-15°, n=34) and a severe varus group (group B, TTA>15°, n=24). There was no significant difference in gender, side, etiology, preoperative American Orthopaedic Foot and Ankle Society (AOFAS) score, ankle dorsiflexion, plantarflexion, and total range of motion, and tibial lateral surface angle (TLS) between the two groups ( P>0.05). Yet the patients in group A were younger than group B, the degrees of oesteoarthritis (Takakura stage) and ankle pain [visual analogue scale (VAS) score] were milder, and the TTA, talar tilt angle (TT), hindfoot alignment angle (HAA) were smaller while the tibial articular surface angle (TAS) was larger, showing significant differences ( P<0.05). The pre- and post-operative VAS score, AOFAS score, the occurrence of early and late complications, the radiographic parameters of the ankle (TTA, TAS, TT, HAA, TLS), ankle dorsiflexion, plantarflexion, and total range of motion were recorded and compared. All patients were followed up 19-72 months, with an average of 38.9 months. Compared with the preoperative data, the VAS score of all patients significantly decreased ( P<0.05); the AOFAS score, ankle dorsiflexion range of motion, and total range of motion significantly increased ( P<0.05); and the TTA, TAS, TT, HAA, and TLS significantly improved at last follow-up ( P<0.05); but there was no significant difference in plantarflexion range of motion ( P>0.05). Early complications occurred in 13 patients, and only 1 patient underwent revision surgery due to a larger size of the talar component. At last follow-up, there was no significant difference in the difference of clinical parameters before and after operation between the two groups ( P>0.05); there was a significant difference in the difference of other radiographic parameters ( P<0.05) except TLS. No significant difference in the incidence of complications between the two groups was found ( P>0.05). TAA using the INBONE TM Ⅱtotal ankle prosthesis is an effective treatment for moderate or severe varus-type ankle arthritis, and good clinical and radiographic results can be obtained. Correcting bony deformities and balancing soft tissue are the keys to successful surgery.

Sport and Exercise Activity After Isolated Ankle Arthrodesis for Advanced-Stage Ankle Osteoarthritis: A Single-Center Retrospective Analysis.

Ankle arthrodesis, a recognized operative treatment for advanced-stage ankle osteoarthritis (OA), is recommended when conservative treatment proves unsuccessful. This single-center retrospective analysis examined the change in functional outcomes and the type of sport/exercise activity performed by advanced-stage ankle OA patients after ankle arthrodesis treatment. A total of 61 advanced-stage ankle OA patients (age, 63.1 ± 12.6 years) who had undergone ankle arthrodesis were included in this single-center retrospective study. The patients had functional outcomes evaluated via American Orthopaedic Foot & Ankle Society Score (AOFAS), Foot Function Index (FFI), Tegner Activity Level Scale (TAS), and High-Activity Arthroplasty Score (HAAS) questionnaires. Clinical status was compared across prearthritic, arthritic, and postarthrodesis periods, and satisfaction with return to sport/exercise activity was recorded. Patients' tarsal sagittal ROM (mean [95% CI]: 22.7 degrees [21.4-24.0]); time to union (15.7 weeks [11.8-19.6]); time to walk without gait aid (14.4 weeks [11.0-17.7]); time to return to work (17.9 weeks [15.1-20.8]); and time to exercise activity (20.6 weeks [17.9-23.4]) were recorded postarthrodesis. Hindfoot alignment angle toward a neutral position (difference: 11.4 degrees [9.2-13.6], P < .001) and functional outcomes (P < .001) significantly improved after arthrodesis surgery; however, only the TAS questionnaire indicated patients returned to their prearthritic activity level (P > .99). Patients generally reported "good" satisfaction with their recovery from ankle arthrodesis surgery, with 64% of patients returning to high-impact-type activity. Advanced-stage ankle OA patients had improved functional outcomes at ~1 year postarthrodesis surgery, enabling the majority of patients to return to high-impact-type activity. Level III, retrospective cohort study.

Comparison of the effect of total knee arthroplasty and high tibial osteotomy on coronal pelvic and ankle–hindfoot alignment

BackgroundTotal knee arthroplasty (TKA) and high tibial osteotomy (HTO) are different procedures on the continuous spectrum of osteoarthritic knee treatments. TKA aims for neutral alignment and HTO aims for slight valgus. Methods2:2:2:1 propensity score matching yielded 100, 100, 100, and 50 patients with unilateral TKA, bilateral TKA, unilateral HTO, and bilateral HTO, respectively. Radiological evaluations of pelvis, knee, ankle, and hindfoot were performed. The important factors affecting the alignment change of the adjacent joints were identified, and subgroup analyses were performed using the identified parameters. The clinical outcomes were also compared. ResultsThe coronal alignments of the adjacent joints were corrected to the neutral position after TKA and HTO. The tibiotalar tilt angle (TTTA) was a common factor that affected changes in the ankle and hindfoot alignment. Patients with larger preoperative TTTA showed larger changes in TTTA in both TKA and HTO groups (P < 0.001). Patients with larger preoperative hindfoot alignment angle (HAA) showed larger changes in tibial plafond inclination, talar inclination, and HAA in both TKA and HTO groups (P < 0.001). TKA groups showed negative pelvic tilt values in the horizontal plane, and HTO groups showed a larger weight-bearing line ratio. ConclusionEven more severe deformities including adjacent joints were observed in TKA patients, both TKA and HTO patients showed improved alignment of the adjacent joints. However, HTO patients showed closer normal alignment than patients who underwent TKA. The preoperative TTTA and HAA were important factors for restoration of ankle and hindfoot alignment after knee surgery.

Simulated Weightbearing Fluoroscopy to Assess Intraoperative Hindfoot Alignment.

Intraoperative evaluation of hindfoot alignment is one of the factors that may affect outcomes for foot and ankle reconstructive surgery. The present study was performed to evaluate the effect of simulated weightbearing fluoroscopy on the intraoperative assessment of hindfoot alignment reconstruction. The medical records of patients diagnosed with disorders of the foot and ankle with abnormal hindfoot alignment were retrospectively reviewed from November 2014 to November 2021. Hindfoot alignment view (HAV) fluoroscopy in the simulated weightbearing position and HAV radiographs were routinely recorded during and after surgery, respectively. The hindfoot alignment angle (HAA) and hindfoot alignment ratio (HAR) were measured on intraoperative and postoperative images, respectively. Seventy-two women and 82 men (155 ankles) with a mean age of 45.48 years were included in the present study. The intraobserver and interobserver reliabilities of the HAA and HAR measurements were satisfactory. The intraoperative and postoperative HAA was -0.7 ± 4.8 degrees and -0.2 ± 5.0 degrees, respectively. The mean HAR on intraoperative fluoroscopy and postoperative radiographs was 37.4% ± 19.7% and 40.4% ± 18.2%, respectively. Simple regression analysis revealed a correlation between the intraoperative and postoperative HAA (R2 = 0.631, P < .001) and HAR (R2 = 0.262, P < .001). Univariate analysis suggested that the difference between the intraoperative and postoperative HAA was positively affected by the body mass index (P < .001). The present study showed that intraoperative HAV fluoroscopy in the simulated weightbearing position is a potentially useful method to predict postoperative hindfoot alignment in the weightbearing position. Patients with a lower body mass index had smaller HAA deviations between intraoperative and postoperative measurements of hindfoot alignment. Level IV, retrospective case series.