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.

Prevalence and pattern of lateral impingements in the progressive collapsing foot deformity.

INTRODUCTION: The prevalence of lateral bony impingements [i.e., Sinus Tarsi (STI), Talo-Fibular (TFI) and Calcaneo-Fibular (CFI)] and their association with Peritalar Subluxation (PTS) have not been clearly established for progressive collapsing foot deformity (PCFD).This study aims to assess the prevalence of STI, TFI and CFI in PCFD, in addition to their association with PTS. We hypothesized that STI and TFI would be more prevalent than CFI. MATERIALS AND METHODS: Seventy-two continuous symptomatic PCFD cases were retrospectively reviewed. Weightbearing computed tomography (WBCT) was used to assess lateral impingements and classified as STI, TFI and CFI. PTS was assessed by the percent of uncovered and the incongruence angle of the middle facet, and the overall foot deformity was determined by the foot and ankle offset (FAO). Data were collected by two fellowship-trained independent observers. RESULTS: Intra-observer and inter-observer reliabilities for impingement assessment ranged from substantial to almost perfect. STI was present in 84.7%, TFI in 65.2% and CFI in 19.4%. PCFD with STI showed increased middle facet uncoverage (p = 0.0001) and FAO (p = 0.0008) compared to PCFD without STI. There were no differences in FAO and middle facet uncoverage in PCFD with TFI and without TFI. PCFD with CFI was associated with STI in 100% of cases. PCFD with CFI showed decreased middle facet incongruence (p = 0.04) and higher FAO (p = 0.006) compared to PCFD without CFI. CONCLUSIONS: STI and TFI were more prevalent than CFI in PCFD. However, only STI was associated with PTS. Conversely, CFI was associated with less PTS, suggesting a different pathological mechanism which could be a compensatory subtalar behavior caused by deep layer failure of the deltoid ligament and talar tilt.

Surgically treated adult acquired flatfoot deformity: Register-based study of patient characteristics, health-related quality of life and type of surgery according to severity.

BACKGROUND: Population-level data describing patient characteristics and interventions used in surgical treatment of adult acquired flatfoot deformity (AAFD) is lacking. METHODS: We analyzed baseline patient-reported data including PROMs and surgical interventions for patients with AAFD reported to the Swedish Quality Register for Foot and Ankle Surgery (Swefoot) 2014-2021. RESULTS: 625 feet with primary AAFD surgery were registered. Median age was 60 (range 16-83) years and 64% were women. Mean preoperative EQ-5D index and Self-Reported Foot and Ankle Score (SEFAS) were low. In stage IIa (n = 319) 78% had medial displacement calcaneal osteotomy and 59% had flexor digitorium longus transfer, with some regional variations. Spring ligament reconstruction was less common. In stage IIb (n = 225), 52% had lateral column lengthening, and in stage III (n = 66), 83% had hind-foot arthrodesis. CONCLUSIONS: Patients with AAFD have low health-related quality of life before surgery. Treatment in Sweden follows best-available evidence but regional variations exist. LEVEL OF EVIDENCE: III.

Does tibialis posterior dysfunction correlate with a worse radiographic overall alignment in progressive collapsing foot deformity? A retrospective study.

BACKGROUND: Posterior Tibial Tendon (PTT) dysfunction is considered to have an important role in Progressive Collapsing Foot Deformity (PCFD). The objective of our study was to assess the relationship between PTT status and three-dimensional foot deformity in PCFD. METHODS: Records from 25 patients with PCFD were included for analysis. The PTT was considered deficient in patients with a positive single heel rise test or a deficit in inversion strength. Three-dimensional foot deformity was assessed using the Foot and Ankle Offset (FAO) from Weight-Bearing-CT imaging. Hindfoot valgus, midfoot abduction and medial longitudinal arch collapse were assessed on X-Rays using hindfoot moment arm, talonavicular coverage angle and Meary's angle respectively. Deland and Rosenberg MRI classifications were used to classify PTT degeneration. RESULTS: PCFD with PTT deficit (13/25) had a mean FAO of 7.75 + /- 3.8% whereas PCFD without PTT deficit had a mean FAO of 6.68 + /- 3.9% (p = 0.49). No significant difference was found between these groups on the hindfoot moment arm and the talonavicular coverage angle (respectively p = 0.54 and 0.32), whereas the Meary's angle was significantly higher in case of PCFD with PTT deficit (p = 0.037). No significant association was found between PTT degeneration on MRI and FAO. CONCLUSION: PCFD associated three-dimensional deformity, hindfoot valgus and midfoot abduction were not associated with PTT dysfunction. PTT dysfunction was only associated with a worse medial longitudinal arch collapse in our study. Considering our results, it does not appear that PTT is the main contributor to PCFD. LEVEL OF EVIDENCE: Level III, Retrospective Comparative Study.

Combined weightbearing CT and MRI assessment of flexible progressive collapsing foot deformity.

BACKGROUND: The objective of this study was to evaluate the correlation between Weightbearing CT (WBCT) markers of pronounced peritalar subluxation (PTS) and MRI findings of soft tissue insufficiency in patients with flexible Progressive Collapsing Foot Deformity (PCFD). We hypothesized that significant correlation would be found. METHODS: Retrospective comparative study with 54 flexible PCFD patients. WBCT and MRI variables deformity severity were evaluated, including markers of pronounced PTS, as well as soft tissue degeneration. A multiple regression analysis and partition prediction models were used to evaluate the relationship between bone alignment and soft tissue injury. P-values of less than .05 were considered significant. RESULTS: Degeneration of the posterior tibial tendon was significantly associated with sinus tarsi impingement (p = .04). Spring ligament degeneration correlated to subtalar joint subluxation (p = .04). Talocalcaneal interosseous ligament involvement was the only one to significantly correlate to the presence of subfibular impingement (p = .02). CONCLUSION: Our results demonstrated that WBCT markers of pronounced deformity and PTS were significantly correlated to MRI involvement of the PTT and other important restraints such as the spring and talocalcaneal interosseus ligaments. LEVEL OF EVIDENCE: Level III, Retrospective comparative study.

American College of Foot and Ankle Surgeons Clinical Consensus Statement: Appropriate Clinical Management of Adult-Acquired Flatfoot Deformity.

This clinical consensus statement of the American College of Foot and Ankle Surgeons focuses on the highly debated subject of the management of adult flatfoot (AAFD). In developing this statement, the AAFD consensus statement panel attempted to address the most relevant issues facing the foot and ankle surgeon today, using the best evidence-based literature available. The panel created and researched 16 statements and generated opinions on the appropriateness of the statements. The results of the research on this topic and the opinions of the panel are presented here.

Review of Classification Systems for Adult Acquired Flatfoot Deformity/Progressive Collapsing Foot Deformity and the Novel Development of the Triple Classification Delinking Instability/Deformity/Reactivity and Foot Type.

Background: Classifications of AAFD/PCFD have evolved with an increased understanding of the pathology involved. A review of classification systems helps identify deficiencies and respective contributions to the evolution in understanding the classification of AAFD/PCFD. Methods: Using multiple electronic database searches (Medline, PubMed) and Google search, original papers classifying AAFD/PCFD were identified. Nine original papers were identified that met the inclusion criteria. Results: Johnson's original classification and multiple variants provided a significant leap in understanding and communicating the pathology but remained tibialis posterior tendon-focused. Drawbacks of these classifications include the implication of causality, linearity of progression through stages, an oversimplification of stage 2 deformity, and a failure to understand that multiple tendons react, not just tibialis posterior. Later classifications, such as the PCFD classification, are deformity-centric. Early ligament laxity/instability in normal attitude feet and all stages of cavus feet can present with pain and instability with minor/no deformity. These may not be captured in deformity-based classifications. The authors developed the 'Triple Classification' (TC) understanding that primary pathology is a progressive ligament failure/laxity that presents as tendon reactivity, deformity, and painful impingement, variably manifested depending on starting foot morphology. In this classification, starting foot morphology is typed, ligament laxities are staged, and deformity is zoned. Conclusions: This review has used identified deficiencies within classification systems for AAFD/PCFD to delink ligament laxity, deformity, and foot type and develop the 'Triple classification'. Advantages of the TC may include representing foot types with no deformity, defining complex secondary instabilities, delinking foot types, tendon reactivity/ligament instability, and deformity to represent these independently in a new classification system. Level of Evidence: Level V.

Chronic Deltoid Insufficiency in Stage IV Adult Acquired Flatfoot Deformity: Do We Have a Good Answer?

Stage IV adult acquired flatfoot deformity (AAFD) with secondary chronic deltoid ligament insufficiency is a challenging deformity to treat, with minimal consensus in the literature concerning its surgical management. Many surgical treatment options have been described, including joint-sparing techniques, fusions, osteotomies, and even arthroplasties. However, questions remain as to what, if any, treatment is optimal. This contribution reviews studies on surgical treatments for stage IV AAFD with deltoid ligament failure and provides a critical analysis regarding the quality of outcomes reported for those different treatment options. PubMed and Google Scholar databases were searched between June 1, 2022, and August 15, 2022, for studies published between 1990 and 2022 that describe the treatment of stage IV AAFD with deltoid ligament insufficiency. Articles included in the study focused on subjects with stage IV AAFD and associated deltoid ligament insufficiency undergoing surgical correction. Exclusion criteria included stage I, II, and III AAFD, as well as deltoid ligament repair following acute injury/rupture. Nine studies covering five different treatment options for patients with stage IV AAFD and chronic deltoid insufficiency were included, with minimal overlap in outcome measures used to assess the efficacy of the procedure. Triple arthrodesis with deltoid ligament reconstruction resulted in a 62.5% (5/8) success rate with a residual tibiotalar (TT) angulation of 2° (success defined as <3°). Tibiotalar arthrodesis of four patients resulted in an average post-operative tibiotalar angulation of 4.8° with all patients showing progressive destabilization of the hindfoot complex at 12-18 year follow-ups. Deltoid arthroscopic laminoplasty (Brostrom) resulted in an increased American Orthopaedic Foot and Ankle Society (AOFAS) score from 49.7 pre-op to 91.9 post-op. There was no long-term follow-up of these patients. Deltoid ligament reconstruction using autografts of the peroneus longus resulted in a post-operative valgus of 2.1° in one study and <5° in another. Deltoid ligament reconstruction using an anterior tibial tendon autograft resulted in a gain of 126.4 + 40.2% in stiffness compared to an intact ligament. Twinfix suture anchors resulted in a post-operative hindfoot angle averaging 5.3°. Combined deltoid and spring ligament reconstruction resulted in a 5.1° valgus angulation. There is currently no standard of care or clinical consensus regarding surgical treatment for stage IV AAFD with deltoid insufficiency. Several studies imply that mild valgus malalignment around the tibiotalar joint can result in satisfactory outcomes. A few studies even deemed <5° of valgus tilt post-operatively successful. However, it has been described that any imbalance in tibiotalar tilt is a significant risk factor for progressive arthritis and future ligamentous failure. No treatment option was able to correct valgus tilt to an anatomical standard (i.e., to normal anatomy). These varied findings, along with the lack of consensus on post-surgical measures to assess efficacy, are worrisome and emphasize the need for better surgical options. Moreover, there is a critical need for additional research on the long-term outcomes following stage IV AAFD and deltoid insufficiency repair, particularly, as over five million people in the United States and 10% of the geriatric population are affected by AAFD with a risk of progressing to stage IV.

Plantar forces in flexor hallucis longus versus flexor digitorum longus transfer in adult acquired flatfoot deformity.

BACKGROUND: Flexor hallucis longus (FHL) and flexor digitorum longus (FDL) tendon transfers are frequently used to restore the function of a deficient tibialis posterior tendon in stage II adult acquired flatfoot deformity (AAFD). Either transfer causes some loss in toe flexion force, although the decision to tenodese the cut tendon to restore associated function remains controversial. This study quantified changes in plantar force before and after tendon transfer and with or without distal tenodesis in a cadaveric model. METHODS: The plantar force distribution of 10 matched pairs of statically loaded cadaveric lower extremities was investigated. Each foot was tested when it was intact, after FDL/FHL tendon transfer, and after tendon transfer + tenodesis. RESULTS: Transfer of either FHL or FDL showed a statistically significant decrease in flexion force of the great toe (P < .01) and lesser toes (P < .001), respectively. Subsequent tenodesis in either tendon demonstrated an ability to restore flexion force in the great (P < .05) and lesser (P < .01) toes, respectively, with the FHL transfer + tenodesis restoring great toe loading to near pretransfer levels. Following either transfer, plantar force increased in the medial forefoot; this was sustained with FDL transfer + tenodesis but reduced under FHL transfer + tenodesis. Lateral forefoot force increased modestly (8%) with FHL transfer (P < .05) but returned to near intact levels with tenodesis. FDL transfer + tenodesis resulted in increased medial midfoot and heel loading. DISCUSSION: FHL or FDL transfer notably reduces associated toe flexion force. This loss can be restored to near normal levels with tenodesis for FHL transfer. As increased lateral forefoot loading is commonly associated with AAFD corrective procedures, FHL tenodesis may mitigate the unintended increases caused by the tendon transfer. The medial midfoot and heel loading with FDL transfer + tenodesis underscores that tendon transfers alone do not reestablish the passive architecture of the foot but augment deficient subtalar inversion force. CLINICAL RELEVANCE: This cadaveric study shows that the FHL is more biomechanically suitable for tibialis posterior tendon insufficiency than the FDL, which may be a basis for a study to investigate whether it is superior in a clinical situation.

Influence of Weightbearing Computed Tomography in the Progressive Collapsing Foot Deformity Classification System.

BACKGROUND: The objective of this study was to compare progressive collapsing foot deformity (PCFD) classifications performed using clinical and conventional radiographs (CR) with classifications established using clinical and weightbearing computed tomography (WBCT). METHODS: This retrospective comparative study evaluated 89 consecutive PCFD feet (84 patients). Three readers performed chart reviews and CR evaluations, determining PCFD classifications that were previously published. After a washout period, the sequence was randomized, and a new classification was executed using clinical and WBCT assessment. One of the readers repeated the WBCT evaluation for intrarater reliability. RESULTS: Interrater reliability for the WBCT was found moderate (0.55) and intrarater excellent (0.98). Evaluation using WBCT produced 29.6% of 1ABC (CR: 25.4%, P = .270), 11.6% of 1ABCD (CR: 6.9%, P = .081), and 6.4% of BC (CR: 3.3%, P = .090) as most prevalent. Class A was presented in 83.9% (CR: 89.5%, P = .55), class B in 89.9% (CR: 76.4%, P < .001), class C in 93.6% (CR: 86.2%, P = .004), class D in 46.4% (CR: 34.8%, P = .006), and class E in 27.7% (CR: 22.5%, P = .158) of the classifications performed by WBCT. CONCLUSION: WBCT showed a different rate of deformity recognition, which increased the incidence of all classes, especially B, C, and D. An excellent intrarater agreement was found, which infers assessment reliability combining clinical and WBCT evaluation. The obtained information could enhance disease understanding and supply patients with more precise care. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Deformities Influencing Different Classes in Progressive Collapsing Foot.

Background: The current classification system of progressive collapsing foot deformity (PCFD) is comprised of 5 possible classes. PCFD is understood to be a complex, three-dimensional deformity occurring in many regions along the foot and ankle. The question remains whether a deformity in one area impacts other areas. The objective of this study is to assess how each one of the classes is influenced by other classes by evaluating each associated angular measurement. We hypothesized that positive and linear correlations would occur for each class with at least one other class and that this influence would be high. Methods: We retrospectively assessed weight bearing CT (WBCT) measurements of 32 feet with PCFD diagnosis. The classes and their associated radiographic measurements were defined as follows: class A (hindfoot valgus) measured by the hindfoot moment arm (HMA), class B (midfoot abduction) measured by the talonavicular coverage angle (TNCA), class C (medial column instability) measured by Meary's angle, class D (peritalar sub-luxation) measured by the medial facet uncoverage (MFU), and class E (ankle valgus) measured using the talar tilt angle (TTA). Multivariate analyses were completed comparing each class measurement to the other classes. A p-value <0.05 was considered significant. Results: Class A showed substantial positive correlation with class C (ρ=0.71; R2=0.576; p=0.001). Class B was substantially correlated with class D (ρ=0.74; R2=0.613; p=0.001). Class C showed a substantial positive correlation with class A (ρ=0.71; R2=0.576; p=0.001) and class D (ρ=0.75; R2=0.559; p=0.001). Class D showed substantial positive correlation with class B and class C (ρ=0.74; R2=0.613; p=0.001), (ρ=0.75; R2=0.559; p=0.001) respectively. Class E did not show correlation with class B, C or D (ρ=0.24; R2=0.074; p=0.059), (ρ=0.17; R2=0.071; p=0.179), and (ρ=0.22; R2=0.022; p=0.082) respectively. Conclusion: This study was able to find relations between components of PCFD deformity with exception of ankle valgus (Class E). Measurements associated with each class were influenced by others, and in some instances with pronounced strength. The presented data may support the notion that PCFD is a three-dimensional complex deformity and suggests a possible relation among its ostensibly independent features. Level of Evidence: III.

Intra- and Interobserver Reliability of the New Classification System of Progressive Collapsing Foot Deformity.

BACKGROUND: Historical concept of flatfoot as posterior tibial tendon dysfunction (PTTD) has been questioned. Recently, the consensus group published a new classification system and recommended renaming PTTD to Progressive Collapsing Foot Deformity (PCFD). The new PCFD classification could be effective in providing comprehensive information on the deformity. To date, there has been no study reporting intra- and interobserver reliability and the frequency of each class in PCFD classification. METHODS: This was a single-center, retrospective study conducted from prospectively collected registry data. A consecutive cohort of PCFD patients evaluated from February 2015 to October 2020 was included, consisting of 92 feet in 84 patients. Classification of each patient was made using characteristic clinical and radiographic findings by 3 independent observers. Frequencies of each class and subclass were assessed. Intraobserver and inteobserver reliabilities were analyzed with Cohen kappa and Fleiss kappa, respectively. RESULTS: Mean sample age was 54.4, 38% was male and 62% were female. 1ABC (25.4%) was the most common subclass, followed by 1AC (8.7%) and 1ABCD (6.9%). Only a small percentage of patients had isolated deformity. Class A was the most frequent component (89.5%), followed by C in 86.2% of the cases. Moderate interobserver reliability (Fleiss kappa = 0.561, P < .001, 95% CI 0.528-0.594) was found for overall classification. Very good intraobserver reliability was found (Cohen kappa = 0.851, P < .001, 95% CI 0.777-0.926). CONCLUSION: Almost half (49.3%) of patients had a presentation dominantly involving the hindfoot (A) with various combinations of midfoot and/or forefoot deformity (B), (C) with or without subtalar joint involvement (D). The new system may cover all possible combinations of the PCFD, providing a comprehensive description and guiding treatment in a systematic and individualized manner, but this initial study suggests an opportunity to improve overall interobserver reliability. LEVEL OF EVIDENCE: Level III, retrospective diagnostic study.

Managing Complications of Foot and Ankle Surgery: Reconstruction of the Progressive Collapsing Foot Deformity.

Our understanding of the cause and principles of treatment of progressive collapsing foot deformity (PCFD) has significantly evolved in recent decades. The goals of treatment remain improvement in symptoms, correction of deformity, maintenance of joint motion, and return of function. Although notable advancements in understanding the deformity have been made, complications still occur and typically result from (1) poor decision making, (2) technical errors, and (3) patient-related conditions. In this article, we discuss common surgical modalities used in the treatment of PCFD and further highlight the common complications that occur and the techniques that can be used to prevent them.

Fusion Versus Joint-Sparing Reconstruction for Patients With Flexible Flatfoot.

AIMS: Passively correctible, adult-acquired flatfoot deformities (AAFD) are treated with joint-sparing procedures. Questions remain as to the efficacy of such procedures when clinical deformities are severe. In severe deformities, a primary fusion may lead to predictable outcomes, but risks nonunion. We evaluated pre- and postsurgical flexible AAFD patients undergoing joint-sparing or fusion procedures, comparing reoperation and complication rates. METHODS: We identified patients with flexible AAFD between January 1, 2001 and 2016. Exclusion criteria were incomplete medical record, rigid AAFD, and prior flatfoot surgery. Patient demographics, pre- and postsurgical radiographic measurements, surgery performed, and postoperative complications were evaluated by bivariate analysis, comparing joint-sparing versus fusion procedures. RESULTS: Of 239 patients (255 feet) (mean follow-up 62 ± 50 months), 209 (87%) underwent joint-sparing reconstructions, 30 (12.6%) underwent fusions. Fifty-four (24.1%) feet underwent joint-sparing reconstruction with reoperation versus 11 (35.5%) in fusion patients (P = .17). Radiographic improvement in talonavicular angle, talar first-metatarsal (anteroposterior view), and Meary's angle was higher in fusion patients (P < .001, P < .001, and P = .003, respectively). DISCUSSION: More nonunion reoperations among fusion patients were offset by reoperations in joint-sparing patients. Fusion uniquely corrected Meary's angle. Nonunion is of less concern for joint-sparing versus fusion for patients with severe flexible AAFD. Degree of deformity versus advantage of joint motion should improve decision making. LEVELS OF EVIDENCE: Level IV: Retrospective case series.

Injuries to the Spring Ligament: Nonoperative Treatment.

The fibrocartilage within the superomedial calcaneonavicular (spring) ligament is part of an interwoven complex of ligaments that span the ankle, subtalar, and talonavicular joints. Acute isolated rupture of the spring ligament has been reported in association with an eversion ankle sprain. Attenuation and failure of the spring ligament causes complex 3D changes called the progressive collapsing foot deformity (PCFD). This deformity is characterized by hindfoot eversion, forefoot supination, collapse of the medial longitudinal arch, and forefoot abduction. Nonoperative treatment of an isolated spring ligament rupture and PCFD using various designs of orthoses have shown promising results.

Diagnostic Accuracy of the Progressive Collapsing Foot Deformity (PCFD) Classification.

BACKGROUND: A consensus group recently proposed the term progressive collapsing foot deformity (PCFD) and a new classification with 2 stages plus 5 classes to describe the complex array of flatfoot deformities. This study aimed to validate different diagnostic accuracy rates of the PCFD classification. METHODS: This was a survey-based study distributed among 13 foot and ankle fellowship programs for 3 groups of participants with varied experience in practice (group 1: fellows in training, group 2: surgeons in practice for 1-4 years, and group 3: surgeons in practice for ≥5 years). Each participant was asked to assign 20 different cases of flatfoot deformity to the appropriate classes and stages using the PCFD classification. The overall diagnostic accuracy, class, and stage diagnostic accuracy rates for the 20 cases were calculated first for the entire cohort and then compared among the 3 groups. The misdiagnosis rate for each class of deformity (the sum of overdiagnosis and underdiagnosis rates) of the entire cohort was calculated and compared with the other classes. Mean and standard evidence were used to describe numerical data. One-way analysis of variance was used to compare values among the 3 groups and the 5 classes. P <.05 was considered statistically significant. RESULTS: For the whole cohort, the overall diagnostic accuracy, class diagnostic accuracy, and stage diagnostic accuracy rates were 71.0%, 78.3%, and 81.7%, respectively There was a statistically significant difference between group 1 and 2, and group 1 and 3, in overall diagnostic accuracy and class diagnostic accuracy, with no significant difference among the 3 groups regarding stage diagnostic accuracy. Class B had a significantly higher overdiagnosis rate than the rest of the classes, whereas class D was significantly underdiagnosed than others. The misdiagnosis rates for classes A to E were 3.3%, 17.5%, 11.1%, 26.0%, and 3.7%, respectively. CONCLUSION: The PCFD classification showed overall fair diagnostic accuracy rates. The highest diagnostic accuracy was for "hindfoot valgus deformity" and "ankle instability." Further content validation of the PCFD classification is needed to examine the terminology and interpretation of those classes with low diagnostic accuracy including "midfoot/forefoot abduction deformity," "forefoot varus deformity/medial column instability," and "peritalar subluxation/dislocation."Level of Evidence: Level II, prospective comparative study.

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.

Progressive Collapsing Foot Deformity: Should We Be Staging It Differently?

This article cursorily reviews the history of classification systems for pathologic flatfoot deformity in the adult and also critically reviews the recent introduction of a classification system intended to improve on the deficiencies of prior systems. The article concludes by offering suggestions for further work in evolving even more utilitarian systems for the staging and treatment of adult flatfoot disorder.

18-Year Operative Incidence and Cost Analysis of the Treatment of Adult Acquired Flatfoot Deformity.

BACKGROUND: Adult acquired flatfoot (AAFD) is commonly treated by foot and ankle surgeons. Despite how commonly this disease presents, its incidence and economic impact have yet to be defined. We hypothesized that the operative incidence of AAFD and its economic burden would increase over the time period 1996 to 2014. METHODS: The South Carolina database was queried for data from acute care and ambulatory surgery centers. Bivariate descriptive statistics were used to analyze the data. Operative incidence was calculated and demographics and medical comorbidities of patients who progressed to operative intervention were analyzed. Costs associated with operative care episodes were calculated to determine the economic burden. RESULTS: A total of 1299 patients underwent AAFD corrective surgery between 1996 and 2014. Patients who underwent surgery for AAFD were most likely to be white, female, and in their fourth, fifth, and sixth decade of life. Operative incidence for AAFD rose from 0.26 per 100 000 covered lives in 1996 to 3.04 in 2014. The total health care costs associated with patients who underwent surgery for AAFD increased from $57 395.33 in 1996 to $6 859 723.60 in 2014. CONCLUSIONS: This data demonstrate that patients most commonly undergoing operative intervention for AAFD were white, female, and in their fourth, fifth, or sixth decade of life. There has been a significant increase in operative incidence, which may help direct attention to further exploration of outcome data in these patient populations, associated treatment costs, and preventative treatment options. LEVEL OF EVIDENCE: Level III, retrospective comparative study.