A comparison between the Bluman et al. and the progressive collapsing foot deformity classifications for flatfeet assessment.

INTRODUCTION: Bluman et al., flatfoot classification is based on posterior tibial tendon (PTT) dysfunction leading to a chronological appearance of several foot deformities. An expert consensus recently proposed a new classification named Progressive Collapsing Foot Deformity (PCFD) in which the focus was shifted to five different independent foot and ankle deformities and their flexibility or rigidity. The aim of this study was to compare Bluman and PCFD classifications. We hypothesize that both classifications will be reliable and that the PCFD classification will allow a larger distribution of the different types of foot deformity. MATERIALS AND METHODS: We performed a retrospective IRB-approved study including 92 flatfeet. Three foot and ankle surgeons reviewed patient files and radiographs to classify each foot using both classifications. Bluman classification was performed one time as initially described and a second time after removing the Angle of Gissane sclerosis sign. Interobserver reliabilities were determined with Fleiss' kappa values. RESULTS: Interobserver reliabilities of Bluman and PCFD classifications were, respectively, substantial 0.67 and moderate 0.55. PCFD Class C and D reliabilities were, respectively, slight 0.07 and fair 0.28. The 276 readings were spread into 10 substages in Bluman and 65 subclasses in PCFD. The progressivity of the Bluman classification prevented the combination of flexible hindfoot valgus (II Bluman, 1A PCFD), midfoot abduction (IIB, 1B) and medial column instability (IIC, 1C) which was frequent in our study (112/276 readings, 40.6%). By removing the Angle of Gissane sclerosis sign from the Bluman classification, the prevalence of stage III decreased from 44.2 to 10.1%. CONCLUSIONS: Bluman and PCFD classifications were reliable. The PCFD classification showed a larger distribution of different types of flatfeet but Classes C and D need better definition. The progressivity of Bluman classification causes inconsistencies and Gissane angle sclerosis sign is inappropriately used and might lead to incorrect surgical indications.

Distal Metatarsal Articular Angle in Hallux Valgus Deformity. Fact or Fiction? A 3-Dimensional Weightbearing CT Assessment.

BACKGROUND: The Distal Metatarsal Articular Angle (DMAA) was previously described as an increase in valgus deformity of the distal articular surface of the first metatarsal (M1) in hallux valgus (HV). Several studies have reported poor reliability of this measurement. Some authors have even called into question its existence and consider it to be the consequence of M1 pronation resulting in projection of the round-shaped lateral edge of M1 head.Our study aimed to compare the DMAA in HV and control populations, before and after computer correction of M1 pronation and plantarflexion with a dedicated weightbearing CT (WBCT) software. We hypothesized that after computerized correction, DMAA will not be increased in HV compared to controls. METHODS: We performed a retrospective case-control study including 36 HV and 20 control feet. In both groups, DMAA was measured as initially described on conventional radiographs (XR-DMAA) and WBCT by measuring the angle between the distal articular surface and the longitudinal axis of M1. Then, the DMAA was measured after computerized correction of M1 plantarflexion and coronal plane rotation using the α angle (3d-DMAA). RESULTS: The XR-DMAA and the 3d-DMAA showed higher significant mean values in HV group compared to controls (respectively 25.9 ± 7.3 vs 7.6 ± 4.2 degrees, P < .001, and 11.9 ± 4.9 vs 3.3 ± 2.9 degrees, P < .001).Comparing a small subset of precorrected juvenile HV (n=8) and nonjuvenile HV (n=28) demonstrated no significant difference in the measure DMAA values. On the other hand, the α angle was significantly higher in the juvenile HV group (21.6 ± 9.9 and 11.4 ± 3.7 degrees; P = .0046). CONCLUSION: Although the valgus deformity of M1 distal articular surface in HV is overestimated on conventional radiographs, comparing to controls showed that an 8.6 degrees increase remained after confounding factors' correction. CLINICAL RELEVANCE: After pronation computerized correction, an increase in valgus of M1 distal articular surface was still present in HV compared to controls. LEVEL OF EVIDENCE: Level III, retrospective case-control study.

Deformity Correction in Ankle Osteoarthritis Using a Lateral Trans-Fibular Total Ankle Replacement: A Weight-Bearing CT Assessment.

Background: Ankle osteoarthritis (AO) is often secondary to prior trauma and frequently presents with joint deformity. Total ankle replacement (TAR) has been shown as a viable surgical option to reduce pain, improve function, and preserve ankle joint range of motion. The standard TAR uses an anterior approach, but recently a lateral trans-fibular approach has been developed. Our aim was to determine if the lateral TAR was able to correct alignment and improve patient reported outcomes (PROs) in patients with end-stage AO. Methods: This IRB-approved, retrospective comparative study included 14 consecutive patients that underwent lateral trans-fibular approach TAR for end-stage AO. All patients had received pre-and post-operative WBCT imaging on the affected foot and ankle. Using multiplanar reconstruction of WBCT images, measures of coronal and sagittal plane ankle alignment: Foot and Ankle Offset (FAO), Talar Tilt Angle (TTA), Hindfoot Moment Arm (HMA), and Lateral Talar Station (LTS) were performed. PROs were collected pre- and postoperatively at the latest clinical follow-up. Results: All patients demonstrated a significant deformity correction in all measurements performed: FAO (7.73%-3.63%, p=0.031), HMA (10.93mm - 5.10mm, p=0.037), TTA (7.9o-1.5o, p=0.003), and LTS (5.25mm-2.83mm, p=0.018). Four of the PROs measured exhibited significant improvement postoperatively, the Tampa Scale for Kinesiophobia (TSK) (42.7-34.5, p=0.012), PRO-MIS Global Physical Health (46.1-54.5, p=0.011), EFAS (5-10.3, p=0.004), and FAAM Daily Living (60.5-79.7, p=0.04). Multivariate analysis assessing the influence of deformity correction in the improvements of PROs found that PROMIS Global Physical Health was significantly associated with improvements in FAO and LTS, TSK associated with HMA, and FAAM Daily Living with FAO and TTA (p<0.05). Conclusion: The results of this retrospective comparative cohort study suggest that the lateral trans-fibular TAR can correct different aspects of AO deformity. The method also impacted PROs, particularly TSK, PROMIS Global Physical Health, EFAS, and FAAM Daily Living. Direct correlation between some of the deformity correction measurements and the significantly improved PROs was found. The obtained data could help surgeons when making treatment decisions and be the base for comparative prospective studies. Level of Evidence: III.

Weightbearing Computed Tomography for Assessment of Foot and Ankle Deformities: The Iowa Experience.

BACKGROUND: Weightbearing computed tomography (WBCT) is a reliable and precise modality for the measurement and analysis of bone position in the foot and ankle, as well as associated deformities. WBCT to assess three dimensional relationships among bones allowed the development of new measurements, as the Foot and Ankle Offset (FAO), which has high inter and intra-rater reliability. This study reports the University of Iowa's experience utilizing WBCT for the care of foot and ankle patients by describing its utility across different orthopedic diseases in improving diagnostic assessment, aiding surgical planning, and expanding the use for objective clinical follow-up. METHODS: The medical records of consecutive patients with various foot and ankle disorders that underwent WBCT examination as part of the standard of care at a single institution between November 2014 and August 2020 were retrospectively reviewed. Patient factors, including body mass index (BMI), sex, and patient comorbidities were collected. 3D coordinates for calculation of FAO were harvested using the Multiplanar Reconstruction (MPR) views were calculated from the obtained exams. Descriptive statistics were performed with Shapiro-Wilk test and the Anderson-Darling tests. RESULTS: 1175 feet and ankles (820 patients) had a WBCT performed over the studied 68 months. 53% of the subjects were male and 47% female. 588 of the acquisitions were from the right side (50.04%) and 587 from the left side (49.96%). Diabetes was present in 15.47% of, Rheumatic diagnoses in 4.52% and smoking habits in 44.10% of patients. Mean BMI of the sample was found to be 32.47 (32.03-32.90, 95% CI). The mean Foot and Ankle Offset (FAO) encountered in the study's population was 2.43 (2.05-2.82, 95% CI; min -30.8, max 37.65; median 2.39). CONCLUSION: This study contains the largest cohort of WBCTs with accompanied FAO measurements to date, which can aid with establishing a new baseline FAO measurement for multiple pathological conditions. Acquiring WBCTs resulted in a variety of more specific diagnoses for patient with foot and ankle complaints. The ability to utilize WBCT for presurgical planning, the capability to provide a 3D reconstruction of patient anatomy, and its use for assessment of advanced relational foot and ankle measurements, such as FAO, demonstrate how WBCT may serve as a remarkable utility in clinical practice and has become a standard of care in our practice at the University of Iowa.Level of Evidence: IV.