Adult-acquired Flatfoot Research Articles

Validation of patient-specific flatfoot models on finite element analysis

Adult-acquired flatfoot causes various deformities. If a patient-specific foot model can be created using the finite element method, it can be used to study the appropriate surgical technique for each patient. Nine patient-specific flatfoot models were created, and loading simulations were performed. To validate the models, the patients’ weight-bearing radiographs were compared with the parameters of the models. The CCC values ranged from 0.917 to 0.993 , all exceeding the moderate threshold according to the McBride criteria. Our model reproduces the biomechanics of a patient’s foot under loading conditions, which may be useful for investigating patient-specific surgical procedures.

Three-Dimensional Bone Alignment from Cone-Beam Computed-Tomography Scans in Weight-Bearing and Clinical Outcomes Following the Modified Grice–Green Surgical Procedure for Adult Acquired Flatfoot

Severe adult-acquired flatfoot deformity is widely addressed surgically via the Grice–Green subtalar arthrodesis. Standard radiographic measurements have been reported, but these are limited to planar views. These complex deformities and the relevant corrections after surgery should be assessed in weight-bearing using 3D analyses now enabled by modern cone-beam CT scans. The present study is aimed at reporting these 3D radiographical foot bone alignments and the clinical results for this surgery. Ten patients were treated with the Grice–Green procedure. This implies inserting an autologous bone graft from the proximal tibial into the extra-articular sinus-tarsi to perform a subtalar arthrodesis. Before and after surgery, the patients were assessed based on the clinical range-of-motion and Foot-Function and Posture Indexes. Three-dimensional models of the tibia, calcaneus, talus, navicular, and 1st metatarsus were reconstructed from cone-beam CT scans in a single-leg up-right posture. Relevant longitudinal axes were defined to calculate ten spatial angles. Post-operatively, a significant realignment was observed for seven angles, including corrections lift-up of the talus (on average by 15°) and subtalar joint (13° in 3D), as well as the Meary’s angle (21°). Only few correlations were found between traditional clinical and novel 3D radiographical measurements, suggesting the former only limitedly represent the corresponding real skeletal status, and the latter thus offer the physician a more comprehensive evaluation. The present original analysis from modern cone-beam CT scans shows precisely the correction of foot and ankle bone alignments achieved using the Grice–Green surgical procedure, finally in 3D and in weight-bearing. For the first time, traditional clinical and score system evaluations are reported together with bone orientation and joint angles in the three anatomical planes.

The Effects of Midfoot/Hindfoot Fusions on the Behaviour of Peroneus Longus Tendon in Adult-Acquired Flatfoot Deformity: A Biomechanical and Finite Element Analysis

Adult-acquired flatfoot has been considered to arise from tibialis posterior tendon deficiency. Recent evidence shows that arch stability is mainly maintained by structures such as plantar fascia and spring ligament. The dysfunction of these ’passive’ stabilizers results in loss of arch integrity that causes forefoot pronation and reactive tendon overload, especially in the tibialis posterior tendon and peroneus longus tendon. The peroneus longus tendon (PLT) spans several midfoot joints and overloads with arch lengthening. The biomechanical stress/changes that occurs in this tendon are not well recognized. This study evaluates the biomechanical consequences that fusions have on peroneus longus tendon stresses in soft-tissue deficiencies associated with flatfoot deformity. A complete computational human foot model was used to simulate different scenarios related to the flatfoot deformity and associated common midfoot/hindfoot fusions, to quantify the biomechanical changes in the peroneus longus tendon. The results showed that the stress of the peroneus longus tendon is especially affected by the fusion of hindfoot joints and depends on the soft tissue types that fail, causal in generating the flatfoot. These results could be useful to surgeons when evaluating the causes of flatfoot and the secondary effects of surgical treatments on tissues such as the peroneus longus tendon.

Cotton Osteotomy: An Integral Midfoot Procedure for Forefoot Varus Correction

Forefoot varus is a component of the adult-acquired flatfoot deformity which had to be dealt with independently because isolated hindfoot procedures are insufficient to address this deformity. The dorsal opening wedge osteotomy of the medial cuneiform also known as the Cotton osteotomy is an effective and reliable procedure in the correction of forefoot varus with consistently reported good outcomes in terms of improved radiographic and functional outcomes with excellent bony union rate. Notably, it is also very versatile in that the degree of sagittal correction can be adjusted freely. The use of anatomic Cotton plates with titanium wedge integration makes the osteotomy even more robust with the prevention of early loss of correction and reduction of shear forces at the osteotomy site. Therefore, we describe our technique and experience using an anatomic Cotton plate with titanium wedge integration in Cotton osteotomy for forefoot varus. Level of Evidence: Level V.

Comparison of the Acute Postoperative Complications Between Isolated Talonavicular Versus Talonavicular and Subtalar (Double) Arthrodesis in Flatfoot Deformity.

Both isolated talonavicular arthrodesis and talonavicular and subtalar (such as double) arthrodesis can be effective treatments for adult-acquired flatfoot deformity (AAFD) with good success rates, but double arthrodesis has become more commonly performed in recent years. The purpose of this study is to evaluate whether isolated talonavicular versus talonavicular and subtalar arthrodesis led to significantly different 30-day postoperative complication rates in patients with AAFD. We performed a retrospective review to identify a large cohort of adult patients with the diagnosis of AAFD or posterior tibial tendon deformity (PTTD) who underwent isolated talonavicular or talonavicular and subtalar arthrodesis between 2006 and 2020 from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP). To investigate whether there was a difference in complication rate between the 2 surgical cohorts, we estimated logistic regression models and log-binomial models on each of the outcomes while also adjusting for sex and age. We found that there was no significant difference in the rate of major complications (P = .567) or readmissions (P = .567) between patients who underwent isolated talonavicular versus talonavicular and subtalar arthrodesis for AAFD. However, there was a significantly higher rate of minor complications in patients who underwent isolated talonavicular arthrodesis when compared with patients who underwent talonavicular and subtalar arthrodesis (P = .009). This study found that there was no increased risk of 30-day postoperative complications or readmissions with talonavicular and subtalar arthrodesis when compared with isolated talonavicular arthrodesis for AAFD. In addition, there was no increased risk of major complications for talonavicular and subtalar arthrodesis when compared with isolated talonavicular arthrodesis, and isolated talonavicular arthrodesis actually carried a higher risk of minor complications for this surgical cohort. This may provide valuable information for surgeons considering surgical treatment for a particular case of AAFD. Level III.

Correlation of Posterior Tibial Tendon Ultrasound with Calcaneal Inclination Angle in Indonesian Professional Athletes with Medial Ankle Pain.

Background: Adult-acquired flatfoot deformity (AAFD) is characterized by partial or complete flattening of the longitudinal medial arch, which develops after maturity. AAFD secondary to posterior tibialis tendon dysfunction (PTTD) is one of professional athletes' most common foot and ankle pathologies. Different modalities and procedures can be used to establish the diagnosis of AAFD and PTTD. However, imaging measurements such as the calcaneal inclination index and ultrasonography (US) of the posterior tibialis tendon (PTT) in professional athletes with medial ankle and focal pain along the PTT have yet to be widely studied. This study investigates the correlation of PTT ultrasound for evaluating PTTD with calcaneal inclination angle (CIA) for evaluating AAFD in professional athletes with medial ankle and focal pain along the PTT. Through this study, clinicians and radiologists may benefit from considering AAFD in athletes with PTTD. Methods: 112 Indonesian professional athletes with medial ankle or foot pain and focal pain along the direction of the PTT underwent foot radiography using the CIA and ankle ultrasound to observe PTT abnormalities. Results: A negative correlation between fluid thickness surrounding the PTT and the CIA (p<0.001; 95% CI - 0.945, - 0.885), as well as a negative correlation between PTT thickness and CIA (p<0.001, 95% CI - 0.926, - 0.845), with a correlation coefficient (r) of - 0.921 and - 0.892, respectively. No significant correlation was found between PTT tear and CIA (p = 0.728; 95% CI -0.223, - 0.159; r - 0.033). Conclusion: This study showed a negative correlation between PTTD and AAFD via ultrasound and CIA in professional athletes with medial ankle and focal pain along the PTT. A better understanding of PTTD and AAFD imaging will lead to more effective management and prompt treatment.

An Update Management of Pes Planus and Pes Cavus

This review article provided an update on managing pes planus and pes cavus, two common foot deformities caused by an imbalance of the forces acting on the foot. The article described the stages of adult-acquired flatfoot deformity and its causes, risk factors, and treatment options, including conservative and surgical approaches. The report also provided information on the clinical and radiological assessment of the condition and the use of various modalities such as orthotics and braces, physical therapy, and medication

Patient Reported Outcomes Following Triple Arthrodesis for Adult Acquired Flat Foot Deformity: Minimum Two Year Follow Up

The aim of this study is to analyze patient-reported outcomes following this procedure as well as any demographics that may confer prognostic capability. A retrospective analysis was conducted of patients who underwent Triple Arthrodesis at our facility from 2014-2021. Patients were selected if they underwent an isolated triple arthrodesis. All cases included either a gastrocnemius recession versus a percutaneous tendo-achilles lengthening depending on the patient's Silverskiold examination. The electronic medical record was utilized to collect basic patient demographics, previous foot and ankle surgeries, hardware failures, additional procedures, and surgical complications. To evaluate outcomes, we compared patient reported outcomes measurement information system (PROMIS) survey scores with the general population and preoperative versus postoperative visual analog scale (VAS) scores. Foot function index (FFI) scores and scores were utilized as a validation tool for our results. A total of 132 patients met the criteria for our study with a total of 50 participants completing the PROMIS and FFI surveys. The average time point at which the outcomes were collected was 5.50 y postoperatively, ranging from 1.65 to 7.57 y. The average PROMIS physical function was 38.35, pain interference was 61.52, and depression was 49.82 for this population. The mean FFI scores were 58.56 for pain, 60.07 for disability, and 48.07 for activity limitation. There was a significant decrease in preoperative and postoperative VAS scores from 5.4 to 2.55 (p < .001). Three patients experienced wound complications related to decreased sensation. Our results indicated that only PROMIS depression scores were within one standard deviation of the population mean following a triple arthrodesis procedure. PROMIS physical function and pain interference were both outside of one standard deviation for the population.

Biomechanical Effects of Medializing Calcaneal Osteotomy on Bones and the Tissues Related to Adult-Acquired Flatfoot Deformity: A Computational Study

Medializing calcaneal osteotomy (MCO) is a flatfoot treatment in stages IIa–IIb. It is true that structural correction is well known, but stress changes in foot tissues have not been sufficiently studied to date. Our objective was to evaluate the stress generated by MCO in both hindfoot and forefoot bones and in some soft tissues that support the arch. A finite element foot model was employed, simulating some situations related to flatfoot development. Results show a higher stress concentration around the osteotomy region when MCO is used in patients with plantar fascia weakness. Additionally, the stress increase found in lateral metatarsals would be the explanation for the long-term pain reported by patients.

Radiographic Outcomes of Titanium Augment vs Bone Graft in Lateral Column Lengthening for Adult-Acquired Flatfoot Deformity.

Lateral column lengthening (LCL) is a surgical procedure used to manage forefoot abduction and, in theory, also increases the longitudinal arch by plantarflexion of the first ray through tensioning the peroneus longus for patients with stage IIB adult acquired flatfoot deformity (AAFD). This procedure utilizes an opening wedge osteotomy of the calcaneus, which is then filled with autograft, allograft, or a porous metal wedge. The primary aim of this study was to compare the radiographic outcomes of these different bone substitutes following LCL for stage IIB AAFD. We conducted a retrospective review of all patients who underwent LCL from October 2008 until October 2018. Preoperative weightbearing radiographs, initial postoperative radiographs, and 1-year weightbearing radiographs were reviewed. The following radiographic measurements were recorded: incongruency angle, talonavicular coverage angle (TNCA), talar-first metatarsal angle (T-1MT), and calcaneal pitch. A total of 44 patients were included in our study. The mean age of the cohort was 54 (range, 18-74). The study cohort was divided into 2 groups. There were 17 (38.7%) patients who received a titanium metal wedge and 27 (61.5%) that received autograft or allograft. Patients that underwent LCL with the autograft/allograft group were significantly older (59 vs 47 years old, P = .006). Patients who underwent LCL with a titanium wedge had a significantly higher preoperative talonavicular angle (32 vs 27 degrees, P = .013). There were no significant differences in postoperative TNCA, incongruency angle, or calcaneal pitch at 6 months or 1 year. At 6 months and 1 year, no radiographic differences were found between autograft/allograft bone substitutes vs titanium wedge in LCL. Level III, retrospective cohort study.

Associated correction of forefoot alignment with hindfoot fusion for pes planovalgus deformity

BackgroundThe present study aimed to investigate changes in hallux alignment after corrective surgery for adult-acquired flatfoot deformity (AAFD). Patients and methodsThe present study retrospectively investigated the changes of hallux alignment in 37 feet (33 patients) which were treated with double or triple arthrodesis of the hindfoot for AAFD between 2015 and 2021 and could be followed up to one year postoperatively. ResultsHallux valgus (HV) angle significantly decreased by a mean 4.1° among the whole 37 subjects and by a mean 6.6° among the 24 subjects who had a preoperative HV angle of 15° or more. Those who had HV correction (HV angle correction ≥ 5°) demonstrated more near-normal postoperative alignment of the medial longitudinal arch and hindfoot than those without HV correction. ConclusionsHindfoot fusion for AAFD could improve preoperative HV deformity to some degree. HV correction was associated with proper realignment of the midfoot and hindfoot. Level of evidenceLevel IV; retrospective case series

Clinical and multi-segment kinematic analysis of a modified Grice arthrodesis to correct type II adult-acquired flat-foot

BackgroundAdult acquired flat foot (AAFF) is a symptomatic postural alteration of the foot due to modifications in bony structures and/or soft tissues supporting the medial longitudinal arch. For the most severe cases, when orthotic solutions do not provide enough pain relief, surgery may be necessary. Research questionIs it possible to restore a normal medial longitudinal arch and to correct the static and dynamic frontal plane alignment of the rearfoot via a modified Grice surgical procedure in AAFF patients? MethodsEleven patients with stage II AAFF were recruited in the study and underwent the Grice procedure. Patients were assessed via gait analysis using a validated multi-segment foot protocol. Double-leg standing static posture and foot joint kinematics during barefoot walking were measured before surgery and at a mean follow-up of 15 ± 8 months. Twenty-seven age-matched healthy subjects without foot morphological alterations were used as control. Patients’ feet were clinically assessed via the Foot Function Index and the Foot Posture Index. Wilcoxon signed rank test was used to assess differences in kinematic and spatio-temporal parameters between pre-op and follow-up evaluations. 1D statistical parametric mapping was used to assess differences in temporal profiles of foot joint rotations. ResultsThe clinical indexes significantly improved at post-op (p < 0.05). No differences in sagittal plane static and dynamic joint rotations were observed between pre-op and post-op. In the frontal plane, metatarsus to calcaneus and midfoot to calcaneus rotation angles significantly improved from pre-op to post-op, with the latter resulting consistent with control data. Range of motion and maximum value of the medial longitudinal arch angle were reduced following surgery. SignificanceThe modified Grice procedure restored a good frontal-plane alignment of rearfoot and midfoot, and the clinical scores provided evidence of its effectiveness in significantly reducing pain and improving the quality of daily activities.

Surgical Correction of Peritalar Subluxation and Subtalar Joint Articular Coverage Improves Patient- Reported Outcomes in Progressive Collapsing Foot Deformity

Category: Hindfoot; Ankle; Midfoot/Forefoot Introduction/Purpose: Optimization of articular joint coverage has been shown to decrease the progression of arthritic degeneration and to improve outcomes in patients with hip and shoulder pathologies. Progressive Collapsing Foot Deformity (PCFD), previously known as Adult-Acquired Flatfoot Deformity, has been demonstrated to advance with peritalar subluxation (PTS), progressively decreased articular coverage of the subtalar joint articular facets (anterior, middle, and posterior), as well as the development of sinus tarsi and subfibular impingements. Outcome assessment in PCFD has focused on improving conventional radiographic measurements such as the talus-first metatarsal angle and the hindfoot moment arm. This study aimed to evaluate improvements of PTS, subtalar joint articular coverage, and extra-articular impingement following PCFD joint-sparing surgical treatment, as well as the influence of these improvements in patient-reported outcomes. Methods: IRB-approved prospective comparative study. Adult PCFD patients that failed conservative treatment for three-months and underwent hindfoot joint-sparing surgical procedures by a single-surgeon were enrolled. Realignment soft-tissue and bony procedures performed were recorded. All patients underwent Weight Bearing CT (WBCT) preoperatively, and at the 3- and 12- months follow-up. Two observers performed traditional WBCT PCFD measurements. The foot bones were segmented, and distance measurements were performed along the entire 3D superior surface of the calcaneus, including the subtalar joint (SJ) articular facets (anterior, middle, and posterior), sinus tarsi and subfibular area. Color-coded coverage maps (CM) were calculated to grade the amount of articular joint coverage and extra-articular impingement. Patient Reported Outcomes (PROs) were recorded at all follow-up time-points. Pre- and postoperative measurements were compared by paired T-Tests/Wilcoxon and a Multivariate regression analysis was utilized to assess the influence of improvements of articular coverage and impingement in PROs. Results: Twenty patients were included (15F/5M), mean age, BMI, and follow-up of respectively 48.1 (22 to 72) years, 33.88 (23.8 to 46.8) kg/m2, and 13.2 (4 to 27) months. Significant improvements in all traditional PCFD WBCT measurements were noted postoperatively. Articular coverage (CM) of the SJ middle and anterior facets improved postoperatively by respectively 13.5% (p=0.02) and 78% (p=0.001). Similarly, improvement in sinus tarsi impingement, with a 69% decrease in sinus tarsi coverage was observed (p&lt;0.001). Significant PROs improvements were also noted, with Pain Catastrophizing Score (PCS) improving from 13.4 to 5.2 (p=0.0032) and the European Foot and Ankle Score (EFAS) from 6 to 8.5 (p=0.036). Improvements in PROs for PCS and EFAS were explained its majority by improvement in SJ articular coverage and sinus tarsi impingement, with R2 values of respectively 84% and 92% for PCS and EFAS. Conclusion: Peritalar subluxation (PTS) is an important marker of Progressive Collapsing Foot Deformity (PCFD). To the author's knowledge, this is the first time that 3D articular coverage maps were utilized to assess deformity correction following surgical treatment in PCFD. We found significant improvements in the subtalar joint (SJ) anterior and middle facet articular coverage as well as significantly decreased sinus tarsi and subfibular impingement. Most importantly, we found that PTS and SJ articular coverage improvements were the most important variables to influence Patient-Reported Outcomes. Three-dimensional evaluation of PTS and joint coverage can hopefully optimize treatment and improve outcomes in PCFD.

A Novel Anatomic Reconstruction for Posterior Tibialis Tendon in Treatment of Flexible Adult-Acquired Flatfoot Deformity.

ObjectiveTo present a novel approach for the anatomic reconstruction of the posterior tibialis tendon (PTT) in restoring plantar insertions and evaluate its efficiency in treating flexible adult‐acquired flatfoot deformity (AAFD) caused by PTT dysfunction.MethodsFor AAFD treatment, a novel PTT reconstruction method was presented. The current study involved 16 patients, including three men, and 13 women, from August 2017 to July 2019. The mean age was 43.2 ± 15.1 years (21–64 years). The innovative PTT repair method was used on all patients. The treatment involved performing a traditional Flexor Digitorum Longus (FDL) transfer in the navicular tuberosity and suturing the plantar insertions to FDL as tension was applied to tighten the plantar structures of the foot. The results were retrospectively analyzed. The clinical outcome was assessed using the pain visual analogue scale (VAS), the satisfaction VAS, and the American Orthopedic Foot and Ankle Society ankle–hindfoot scale (AOFAS‐AH). Isokinetic testing was performed using a dynamometer at 60°/s and 120°/s for inversion/eversion and plantarflexion/dorsiflexion, respectively, to determine the mean peak torque. Radiographic measurements were employed to assess the outcomes.ResultsBone surgeries combined with the modified anatomic PTT reconstruction were performed on patients with medializing calcaneal osteotomy in 12 (75%) patients and subtalar joint fusion in four (25%) patients. The branch linking to the plantar insertions was detected in every case, with an average width of 3.5 ± 0.8 mm (3.1–4.3 mm). All patients were followed up for the mean of 16.8 ± 1.8 months (range, 15–20 months). The average postoperative functional scores, including pain VAS, satisfaction VAS, total AOFAS‐AH, and all AOFAS‐AH sub‐scales, steadily improved during the follow‐up. In the last follow‐up, isokinetic testing revealed no loss of plantarflexion strength (p = 0.350 and 0.098) and significant improvement in the inversion strength (p = 0.007 and 0.008) in the operated ankles at 60°/s and 120°/s. Radiographic outcomes, particularly the talar head uncovering, improved significantly after more than a year (p < 0.001 for all).ConclusionsThe novel technique for PTT reconstruction in restoring the plantar insertions serves as an effective procedure in treating AAFD caused by PTT dysfunction in terms of delivering a consistent improvement in ankle inversion strength, medial longitudinal arch restoring, and satisfactory clinical outcomes.

Adult-Acquired Flatfoot Deformity: Combined Talonavicular Arthrodesis and Calcaneal Displacement Osteotomy versus Double Arthrodesis.

Background: Adult-acquired flatfoot deformity due to posterior tibial tendon dysfunction (PTTD) is one of the most common foot deformities among adults. Hypothesis: Our study aimed to confirm that the combined procedures of calcaneal displacement osteotomy and talonavicular arthrodesis are equivalent to double arthrodesis. Methods: Between 2016 and 2020, 41 patients (13 male and 28 females, mean age of 63 years) were retrospectively enrolled in the comparative study. All deformities were classified into Stages II and III of PTTD, according to Johnson and Strom. All patients underwent isolated bony realignment of the deformity: group A (n = 19) underwent calcaneal displacement osteotomy and talonavicular arthrodesis, and group B (n = 23) underwent double arthrodesis. Measurements from the Foot Function Index-D (FFI-D) and the SF-12 questionnaire were collected, with a comparison of pre- and post-operative radiographs conducted. The mean follow-up period for patients was 3.4 years. Results: The mean FFI-D was 33.9 (group A: 34.5; group B: 33.5), the mean SF-12 physical component summary was 43.13 (group A: 40.9; group B: 44.9), and the mean SF-12 mental component summary was 43.13 (group A: 40.9; group B: 44.9). The clinical data and corrected angles showed no significant intergroup differences. Conclusion: Based on the available data, our study confirmed that the combined procedures of talonavicular arthrodesis and calcaneal shift, with preservation of the subtalar joint, can be considered equivalent to the established double arthrodesis, with no significant differences in terms of clinical and radiological outcomes.

Three-Dimensional Distance and Coverage Maps in the Assessment of Peritalar Subluxation in Progressive Collapsing Foot Deformity

Category:Ankle; Basic Sciences/Biologics; Hindfoot; OtherIntroduction/Purpose:Progressive collapsing foot deformity (PCFD), formerly termed Adult-Acquired Flatfoot Deformity (AAFD), is a complex 3-dimensional (3D) deformity characterized by peritalar subluxation (PTS) of the hindfoot through the triple joint complex. PTS severity is typically measured at the posterior facet of te subtalar joint, but recent studies have called this into question and presented the middle facet as a more accurate marker of deformity. The objective of this study was to use 3D distance mapping (DM) from weightbearing computed tomography (WBCT) images to assess PTS in PCFD patients and controls across the entire peritalar suface. We hypothesized that 3D DMs would identify the middle facet as a superior marker for PTS, as well as indicate increased extra-articular sinus tarsi and subfibular inpingements in PCFD patients.Methods:In this case control study, we analyzed WBCT data of 20 consecutive patients with flexible PCFD and 10 controls. Novel 3D distance mapping (DM) technique was used to objectively characterize joint coverage across the entire peritalar surface, including both articular (anterior, middle and posterior facets of the subtalar joint) and nonarticular regions (sisus tarsi and subfibular areas). Distance maps were measured in millimeters, and colored to highlight regions of interest. Distances from 1-4mm were shown in blue to indicate expected joint interaction/extra-articular proximity, while distances under 1mm were highlighted in yellow/red indicating close bone proximity consistent with joint space narrowing (articular) or impingement (extra-articular). Joint coverage was defined as percentage of articular area with DMs <4 mm. Coverage Maps (CM) were built highlighting areas of adequate joint interaction (blue), joint subluxation (pink), and impingement (red). Comparisons were performed with independent t-tests or Wilcoxon tests. P values <.05 were considered significant.Results:Overall, coverage was decreased in articular regions and impingement was increased in nonarticular regions of PCFD patients. Objectively, a significant 46.6% average increase in the uncoverage of the middle facet of the subtalar joint was observed in PCFD patients (p<.001), consistent with signifcant middle facet subluxation when compared to controls. No significant similar uncoverage was identified in the anterior or posterior facets. Extra-articularly, an overall 98% increase in sinus tarsi coverage was identified in PCFD patients (p<.007) with direct sinus tarsi impingement in 6 of 20 patients with PCFD, and one of the controls. Direct subfibular impingement was noted in only 1 of 20 PCFD patients, but subfibular space narrowing greater than 2 standard deviations was noted in 17 of 20 PCFD patients. Attached figures demonstrate examples of distance and coverage maps, as well as a comparative averaged assessment of peritalar surface coverage in PCFD and controls.Conclusion:Our study results revealed that when compared to controls PCFD patients demonstrated that a significant decrease in 3D measures of subtalar joint coverage was only identified in the middle facet, but not at the anterior or posterior facets. We also determined significantly decreased inter-bone distances in the sinus tarsi and subfibular regions of PCFD patients, confirming the occurrence of extra-articular impingement in those areas. We hope that the use of these 3D accurate and objective measures of distance (DM) and coverage maps (CM) of middle facet subluxation will support early detection of PCFD patients at high risk for progressive collapse.

Three-Dimensional Coverage Maps in the Assessment of Chopart Subluxation in Progressive Collapsing Foot Deformity

Category:Basic Sciences/Biologics; Hindfoot; Midfoot/ForefootIntroduction/Purpose:Progressive collapsing foot deformity (PCFD), formerly termed Adult-Acquired Flatfoot Deformity (AAFD), is a complex 3D deformity characterized by peritalar subluxation (PTS) of the hindfoot through the triple joint complex. In this context, adjacent structures may adopt different positions and boney relations can change, producing areas increased contact or subluxation. The objective of this study was to use 3D distance maps (DMs) and coverage maps (CMs) from weightbearing CT (WBCT) images to assess subluxation across the Chopart joint in PCFD patients. We hypothesized that CMs would show decreased coverage indicative of subluxation through certain regions of the Chopart joint in PCFD patients when compared to the controls.Methods:In this IRB-approved, retrospective case-control study, we analyzed WBCT data of 18 consecutive patients with flexible PCFD and 10 controls. Using principle component analysis, candidate coverage area was divided into nine regions on the talar head and 4 regions on the calcaneal-cuboid (CC) articular surface. Novel 3D distance mapping (DM) technique was used to objectively characterize joint coverage across the entire Chopart joint surface on both the talus and calcaneus. Distance maps were measured in millimeters and colored to highlight covered areas. Areas with distances less than 4mm were defined to be covered, while areas with distances greater than 4mm were considered to be uncovered. Joint coverage was defined as percentage of articular area with DMs lower than 4 mm. Coverage Maps (CM) were created to highlight areas of coverage (teal) versus non- coverage (pink). Comparisons were performed with independent t-tests, assuming unequal variances. P values <.05 were considered significant.Results:Changes in coverage percentages of PCFD cases relative to controls are indicated in attached figure 1. The middle lateral region of the talar head was found to have a 9% increase in coverage in PCFD cases relative to the controls (p = 0.011). The plantar region of the calcaneal-cuboid joint was found to have a 18% decrease in coverage compared to the controls. Except for the dorsal medial regions, the medial side of the talar head saw overall decreases in coverage. However, these values were not statistically significant. On the calcaneus, the plantar region of the calcaneal-cuboid joint was found to have a significant coverage decrease of 18% relative to the controls (p = 0.017). There was also a decrease in coverage observed in the medial region of the calcaneal-cuboid joint and an increase in the dorsal and lateral areas.Conclusion:Our results support the occurrence of significant Chopart joint changes in early flexible PCFD. Increased lateral and decreased medial/plantar talar head coverage point to internal rotation and plantarflexion of the talus. Associated dorsal migration of the cuboid where plantar and medial areas have decreased coverage indicate subluxation through the entirety of the Chopart joint. Novel 3D coverage mapping enabled objective quantification of subluxation though the Chopart joint in early stage PCFD. These findings may assist clinical decision making regarding the restoration of normal joint alignment during PCFD corrections. Further studies are needed to establish thresholds of change associated with degeneration.

Radiographic Outcomes of Talonavicular Joint Arthrodesis With Varying Fixation Techniques in Stage III Adult Acquired Flatfoot Reconstruction

Utilization of the talonavicular joint (TN) arthrodesis as an isolated procedure or in combination with hindfoot arthrodesis has been described in the literature for treatment of numerous hindfoot conditions. When used in isolation or with concomitant hindfoot arthrodesis, the TN joint has demonstrated nonunion rates reported as high as 37% in the literature. Despite previous research, there remains a lack of agreement upon the ideal fixation technique for TN joint arthrodesis with and without concomitant subtalar joint arthrodesis. The purpose of this study was to retrospectively compare the radiographic and clinical results of TN joint arthrodesis as part of double arthrodesis procedure utilizing 4 separate fixation constructs in the treatment of advanced hindfoot malalignment in stage III adult-acquired flatfoot deformity. We retrospectively reviewed 105 patients who underwent TN joint arthrodesis as part of double arthrodesis procedure utilizing 4 separate fixation constructs. Our results demonstrated a nonunion rate of 16.2%, with 17 nonunions identified within our patient population. One (2.4%) nonunion was observed in the 3-screw cohort, 7 (33.3%) nonunions were observed in the 2-screw cohort, 4 (16.0%) nonunions were observed in the 2-screw plus plate cohort, and 5 (29.4%) nonunions were observed in the 1-screw plus plate cohort. The difference in nonunion rate between the 4 cohorts was statistically significant. Based on these results, we conclude that the use of a 3-screw construct for TN joint arthrodesis as part of double arthrodesis procedure demonstrates a statistically significant reduction in nonunion rate and should be considered a superior fixation construct for this procedure.

Radiographic Analysis and Clinical Efficacy of Hindfoot Arthrodesis With Versus Without Cotton Osteotomy in Stage III Adult Acquired Flatfoot Deformity

Forefoot varus develops as a result of longstanding adult-acquired flatfoot deformity (AAFD). This occurs with varying degrees of deformity and flexibility. Residual forefoot varus following hindfoot realignment in AAFD can lead to lateral column loading and a persistent pronatory moment in efforts to reestablish contact between the forefoot and the ground. The Cotton osteotomy may serve as a reasonable adjunct procedure to help avoid complications and poor outcomes associated with residual forefoot varus in patients undergoing hindfoot arthrodesis for stage III AAFD. The aim of this study was to compare the radiographic outcomes in patients undergoing isolated hindfoot arthrodesis to patients undergoing hindfoot arthrodesis with adjunctive cotton osteotomy. We retrospectively reviewed 47 patients matched based upon age, sex, and comorbidities who underwent hindfoot reconstruction for the treatment of stage III AAFD between 2015 and 2019. A retrospective radiographic review was performed on standard weightbearing radiographs including anterior-posterior and lateral views preoperatively, postoperatively at the initiation of full weightbearing, and at final follow-up. Statistical analysis utilizing paired t test to calculate p values where <.05 was statistically significant. At final follow-up, radiographic measurements showed statistically significant differences in CAA, calcaneal inclination, talo-calcaneal, and talar tilt (p value <.05). The Cotton osteotomy group showed a quicker return to presurgical activity level and a decreased incident of tibiotalar valgus. Our study suggests that the Cotton osteotomy can address residual forefoot varus and potentially prevent further progression of ankle valgus in AAFD when used in combination with hindfoot arthrodesis.

Imaging of progressive collapsing foot deformity with emphasis on the role of weightbearing cone beam CT.

The term progressive collapsing foot deformity (PCFD) is currently recommended as the replacement to adult-acquired flatfoot deformity and posterior tibial tendon dysfunction to better reflect its pathology, which consists of a complex three-dimensional deformity involving the foot and ankle. The new consensus has also provided a new classification that requires clinical and radiographic findings for patient stratification into each class. However, conventional radiographs are susceptible to errors resulting from the inadequate positioning of patients, incorrect angulation of the X-ray tube, and overlapping of bone structures. Weightbearing cone beam computed tomography (WBCBCT), which has greater diagnostic accuracy than conventional radiograph, is useful for evaluating progressive collapsing foot deformity to determine medial arch collapse, hindfoot alignment, peritalar subluxation, posterior subtalar joint valgus, intrinsic talus valgus, and lateral extra-articular bone impingement. The present review aimed to discuss the new recommendations for nomenclature, classification, and imaging evaluation of PCFD, with an illustrative and quantitative focus on the measurements used in conventional radiography and WBCBCT. The measurements presented here are important criteria for decision-making.