Contribution of Lateral Column Lengthening to Correction of Forefoot Abduction in Stage IIb Adult Acquired Flatfoot Deformity Reconstruction

Biomechanical effects of Evans versus Hintermann osteotomy for treating adult acquired flatfoot deformity: a patient-specific finite element investigation

BACKGROUND

Evans and Hintermann lateral column lengthening (LCL) procedures are both widely used to correct adult acquired flatfoot deformity (AAFD), and have both shown good clinical results. The aim of this study was to compare these two procedures in terms of corrective ability and biomechanics influence on the Chopart and subtalar joints through finite element (FE) analysis.

METHODS

Twelve patient-specific FE models were established and validated. The Hintermann osteotomy was performed between the medial and posterior facets of the subtalar joint; while, the Evans osteotomy was performed on the anterior neck of the calcaneus around 10 mm from the calcaneocuboid joint surface. In each procedure, a triangular wedge of varying size was inserted at the lateral edge. The two procedures were then compared based on the measured strains of superomedial calcaneonavicular ligaments and planter facia, the talus-first metatarsal angle, and the contact characteristics of talonavicular, calcaneocuboid and subtalar joints.

RESULTS

The Hintermann procedure achieved a greater correction of the talus-first metatarsal angle than Evans when using grafts of the same size, indicating that Hintermann had stronger corrective ability. However, its distributions of von-Mises stress in the subtalar, talonavicular and calcaneocuboid joints were less homogeneous than those of Evans. In addition, the strains of superomedial calcaneonavicular ligaments and planter facia of Hintermann were also greater than those of Evans, but both generally within the safe range (less than 6%).

CONCLUSION

This FE analysis study indicates that both Evans and Hintermann procedures have good corrective ability for AAFD. Compared to Evans, Hintermann procedure can provide a stronger corrective effect while causing greater disturbance to the biomechanics of Chopart joints, which may be an important mechanism of arthritis. Nevertheless, it yields a better protection to the subtalar joint than Evans osteotomy.

CLINICAL RELEVANCE

Both Evans and Hintermann LCL surgeries have a considerable impact on adjacent joints and ligament tissues. Such effects alongside the overcorrection problem should be cautiously considered when choosing the specific surgical method.

LEVEL OF EVIDENCE

Level III, case-control study.

Which parameters predict correction of the intermetatarsal angle after first metatarsophalangeal fusion?

Fusion of the first metatarsophalangeal joint (MTPJ) is a commonly performed surgical procedure. Although the effect of first MTPJ fusion on reduction of Intermetatarsal angle (IMA) is well described, contributing factors remain unclear. The aim of this study was to identity predictive parameters for IMA reduction. Fifty-one patients (68 feet) who underwent a first MTPJ fusion and had an IMA greater than fourteen degrees were assessed retrospectively. The average age was 68 (31.4-79.3) years. Sixteen demographic and radiographic variables were evaluated using a multivariate regression analysis for association with change in IMA after surgery. The mean preoperative IMA was 16.11 (range, 14.0-22.5) degrees with a mean reduction of 4.95 (range, 0-17) degrees after surgery. Multivariate regression analysis revealed three significant independent predictors of the change in IMA. Increased preoperative IMA (β = .663, CI = .419, .908, P <.001), increased preoperative translation at base of MT1 (β = .490, CI = 0.005, .974, P = 0.039), and less postoperative translation in the fusion (β= -0.693, CI= -1.054, -.331, P= 0.002) significantly increased the amount of IMA reduction. Pre-operative IMA and translation at the base of the first metatarsal were positive predictors for correction of IMA after first MTPJ fusion. Translation at the level of the MTP I fusion was a negative predictor for the amount of IMA correction. Based on these findings, we recommend minimizing the lateral translation of the proximal phalanx relative to the metatarsal head to optimize IMA correction after MTPJ fusion.

Medium- to Long-term Results of Nonanatomic Spring Ligament Reconstruction Using an Allograft Tendon in Progressive Collapsing Foot Deformity With Severe Abduction Deformity

BACKGROUND

Spring ligament reconstruction (SLR) has been suggested as an adjunct to other reconstructive procedures to potentially avoid talonavicular joint fusion in progressive collapsing foot deformity (PCFD) with severe abduction deformity. Most clinical reports present short-term follow-up data and a small number of patients. The purpose of this study was to examine the medium- to long-term outcomes of an SLR using allograft tendon augmentation as part of PCFD surgical reconstruction. This study to our knowledge represents the largest number of patients and the longest follow-up to date.

METHODS

This study retrospectively reviewed 26 patients (27 feet, mean age of 61.4 years) who underwent SLR with allograft tendon as part of PCFD reconstruction. The mean follow-up of the cohort was 8 years (range, 5-13.4). Radiographic evaluation consisted of 5 parameters including talonavicular coverage angle (TNC), with the maintenance of correction being evaluated by comparing parameters from the early postoperative period (mean: 11.6 months, range, 8-17) to final follow-up. Foot and Ankle Outcome Score (FAOS) and patient satisfaction questionnaires were collected at final follow-up. Conversion to talonavicular or subtalar fusion was considered as a failure.

RESULTS

Final radiographs demonstrated successful abduction correction, with the mean TNC improving from 43.7 degrees preoperatively to 14.1 degrees postoperatively (P < .0001). All other radiographic parameters improved significantly and exhibited maintenance of the correction. All FAOS subscales showed significant improvement. Responses to the satisfaction questionnaire were received from all except 1 patient, of whom 88.5% (23/26) were satisfied with the results, 96.2% (25/26) would undergo the surgery again, and 88.5% (23/26) would recommend the surgery. Eight feet (29.6%) required painful hardware removal and 1 (3.7%) developed nonunion of the lateral column lengthening osteotomy. No patient required conversion to talonavicular or subtalar fusion.

CONCLUSION

This study demonstrates favorable medium- to long-term outcomes following PCFD reconstruction including an SLR with allograft tendon augmentation.

LEVEL OF EVIDENCE

Level IV, case series.

Axial Plane Rotation of the Talus in Progressive Collapsing Foot Deformity: A Weightbearing Computed Tomography Analysis

BACKGROUND

Progressive collapsing foot deformity (PCFD) is recognized as a 3-dimensional deformity centered around the talus. Previous studies have described some features of talar motion in the ankle mortise in PCFD, such as sagging in the sagittal plane or valgus tilt in the coronal plane. However, axial plane alignment of the talus in the ankle mortise in PCFD has not been investigated extensively. The purpose of this study was to examine this axial plane alignment of PCFD vs controls using weightbearing computed tomography (WBCT) images and to determine if talar rotation in the axial plane is associated with increased abduction deformity, as well as to assess the medial ankle joint space narrowing in PCFD that may be associated with axial plane talar rotation.

METHODS

Multiplanar reconstructed WBCT images of 79 patients with PCFD and 35 control patients (39 scans) were retrospectively analyzed. The PCFD group was divided into 2 subgroups depending on preoperative talonavicular coverage angle (TNC): moderate abduction (TNC 20-40 degrees, n=57) and severe abduction (TNC >40 degrees, n=22). Using the transmalleolar (TM) axis as a reference, the axial alignment of the talus (TM-Tal), calcaneus (TM-Calc), and second metatarsal (TM-2MT) were calculated. Difference between TM-Tal and TM-Calc was calculated to examine talocalcaneal subluxation. A second method to assess talar rotation within the mortise utilized an angle between the lateral malleolus and the talus (LM-Tal) in the axial slices of WBCT. In addition, the prevalence of medial tibiotalar joint space narrowing was assessed. These parameters were compared between the control and PCFD groups, and between moderate and severe abduction groups.

RESULTS

The talus was significantly more internally rotated with respect to the ankle TM axis and the lateral malleolus in PCFD patients compared to controls, and in the severe abduction group compared with the moderate abduction group, using both measurement methods. Axial calcaneal orientation did not differ between groups. There was significantly greater axial talocalcaneal subluxation in the PCFD group, and this was also greater in the severe abduction group. The prevalence of medial joint space narrowing was higher in PCFD patients.

CONCLUSION

Our findings suggest that talar malrotation in the axial plane should be considered an underlying feature of abduction deformity in PCFD. The malrotation occurs in both the talonavicular and ankle joints. This rotational deformity should be corrected at the time of reconstructive surgery, especially in cases of severe abduction deformity. In addition, medial ankle joint narrowing was observed in PCFD patients, with a higher prevalence of medial ankle joint narrowing in those with severe abduction.

LEVEL OF EVIDENCE

Level III, case-control study.

Osteotomía de Evans sin injerto óseo en el pie plano estadio IIB del adulto

Objetivo: Evaluar los resultados radiográficos y funcionales al año de la cirugía, en una serie consecutiva de pacientes con diagnóstico de pie plano valgo estadio IIB, sometidos a una osteotomía de Evans sin injerto óseo. Materiales y Métodos: Se evaluó, en forma retrospectiva, a dos grupos de pacientes: grupo 1 (placa con espaciador, n = 12) y grupo 2 (celdas de PEEK, n = 14). La edad promedio era de 47 años (DE 18) en el grupo 1 y de 54 años (DE 12) en el grupo 2. Resultados: Se evaluó a 26 pacientes (28 pies operados); 20 (77%) eran mujeres. Las mediciones radiográficas: ángulo de inclinación del calcáneo, ángulo astrágalo-calcáneo (perfil), ángulo astrágalo-calcáneo (frente), cobertura astragalonavicular, altura de la columna medial, longitud de la columna externa, arrojaron diferencias estadísticamente significativas entre las determinaciones preoperatorias y al año dela cirugía. El puntaje promedio de la escala de la AOFAS al año fue de 96 (DE 4,70) en el grupo 1 y de 95 (DE 4,98) en el grupo 2. El puntaje en la escala analógica visual para dolor fue de 1,2 (DE 0,42) en el grupo 1 y 1,16 (DE 0,46) en el grupo 2. Conclusiones: De acuerdo con los resultados obtenidos, concluimos en que la osteotomía de Evans sin el uso de injerto óseo logra preservar las correcciones obtenidas en el mediano plazo utilizando placas con espaciador o celdas de PEEK.

Adult Acquired Flatfoot Deformity: A Narrative Review about Imaging Findings

Adult acquired flatfoot deformity (AAFD) is a disorder caused by repetitive overloading, which leads to progressive posterior tibialis tendon (PTT) insufficiency. It mainly affects middle-aged women and occurs with foot pain, malalignment, and loss of function. After clinical examination, imaging plays a key role in the diagnosis and management of this pathology. Imaging allows confirmation of the diagnosis, monitoring of the disorder, outcome assessment and complication identification. Weight-bearing radiography of the foot and ankle are gold standard for the diagnosis of AAFD. Magnetic Resonance Imaging (MRI) is not routinely needed for the diagnosis; however, it can be used to evaluate the spring ligament and the degree of PTT damage which can help to guide surgical plans and management in patients with severe deformity. Ultrasonography (US) can be considered another helpful tool to evaluate the condition of the PTT and other soft-tissue structures. Computed Tomography (CT) provides enhanced, detailed visualization of the hindfoot, and it is useful both in the evaluation of bone abnormalities and in the accurate evaluation of measurements useful for diagnosis and post-surgical follow-up. Other state-of-the-art imaging examinations, like multiplanar weight-bearing imaging, are emerging as techniques for diagnosis and preoperative planning but are not yet standardized and their scope of application is not yet well defined. The aim of this review, performed through Pubmed and Web of Science databases, was to analyze the literature relating to the role of imaging in the diagnosis and treatment of AAFD.

Radiographic Analysis of the Lateral Column Lengthening Procedure in Stage II Adult Acquired Flatfoot Deformity

Adult acquired flat foot deformity (AAFD) is a progressive, tri-planar deformity involving collapse of the medial longitudinal arch, valgus deformity of the rear foot, and abduction of the mid-foot on the rear foot. There are a wide variety of surgical treatment options for this deformity, including lateral column lengthening (LCL) which results in tri-planar correction of AAFD. We retrospectively reviewed weightbearing preoperative radiographs and weight-bearing 6-week postoperative radiographs of 34 patients with stage II AAFD who underwent LCL (with and without concurrent procedures) with a minimum of 1-year of follow up. Outcomes, including complications and postoperative differences in 6 types of angle measurements were evaluated. Radiographic evaluation showed statistically significant differences in preoperative and postoperative measures in the following angles: calcaneal inclination, Meary's, Simmons, talocalcaneal, and metatarsus adductus (each p ≤ .05). Postoperative Engel's angle difference did not reach statistical significance (p = .07). Paired t tests showed TN coverage angles increased greater with LCL plus a Cotton osteotomy as compared to isolated LCL. Additionally, there was no significant difference in TN coverage angle based on LCL graft size (p = .20). Furthermore, the distance of the osteotomy from the calcaneocuboid joint on anteroposterior and lateral radiographs did not significantly predict TN coverage angle change. Our study suggests that LCL corrects AAFD in three planes while decreasing the metatarsus adductus angle. LCL appears to be more effective when performed with a Cotton osteotomy. Wedge size (6 mm, 8 mm, 10 mm) and osteotomy location did not demonstrate a relationship with postoperative TN coverage angle or incidence of lateral column overload.

Non-invasive and quantitive analysis of flatfoot based on ultrasound

Flatfoot is a common foot deformity that seriously affects the quality of life. The aim of this study is to develop an accurate and noninvasive method for the diagnosis of flatfoot based on B-mode ultrasound. In this study, 51 patients (the flatfoot group) and 43 healthy subjects (the control group) were included. The plantar fascia angle, a new measurement for use in the diagnosis of flatfoot is proposed, as determined using B-mode ultrasound. For comparison, the calcaneal pitch angle and medial cuneiform height were also measured using lateral X-radiography, based on traditional diagnostic methods. The intraclass correlation values of the plantar fascia angle, the calcaneal pitch angle, and the medial cuneiform height were all more than 0.95, and there is a moderate correlation (r = 0.51) between the medial cuneiform height and the calcaneal pitch angle, and an excellent correlation (r = 0.85) between the plantar fascia angle and the calcaneal pitch angle. The optimal cutoff value, sensitivity, and specificity for medial cuneiform height in flatfoot diagnosis were 12.8 mm, 93.0%, and 54.9%, respectively. The optimal cutoff value, sensitivity, and specificity for plantar fascia angle in flatfoot diagnosis were 9.8°, 97.7%, and 94.1%, respectively. The proposed plantar fascia angle has good sensitivity and specificity in diagnosing flatfoot, therefore supplying a new approach for the noninvasive diagnosis of flatfoot.

Radiographic Cutoff Values for Predicting Lateral Bony Impingement in Progressive Collapsing Foot Deformity

BACKGROUND

Lateral bony impingement is a major cause of lateral foot pain in progressive collapsing foot deformity (PCFD). Weightbearing computed tomography (WBCT) provides better sensitivity than standard radiographs for detecting impingement. However, many orthopaedic centers have not yet acquired WBCT imaging. This study aimed to (1) investigate the correlation of common radiographic parameters measured on standard weightbearing radiographs with talocalcaneal and calcaneofibular distance assessed with WBCT and (2) establish radiographic cutoff values to detect bony impingement as identified on WBCT.

METHODS

Ninety-one patients treated for PCFD with standard preoperative radiographs and WBCT were identified. Patients with asymmetric ankle arthritis (talar tilt >2 degrees) were excluded. The talocalcaneal distance at the sinus tarsi and calcaneofibular distance were measured in multiplanar reconstructed WBCT images. Impingement was defined as direct abutment between bones. The relationships between WBCT measurements and 4 common parameters (talonavicular coverage angle [TNC], talo-first metatarsal angle, calcaneal pitch, and hindfoot moment arm [HMA]) in standard radiographs were assessed with Pearson correlations. Receiver operating characteristic curve analysis evaluated the ability of radiographic cutoffs to detect sinus tarsi or calcaneofibular bony impingement, and the area under curve (AUC), sensitivity, specificity, negative and positive predictive value (PPV) were calculated.

RESULTS

Talocalcaneal distance narrowing at the sinus tarsi strongly correlated with TNC (r = 0.64, P < .001), and the calcaneofibular distance narrowing correlated with the HMA moderately yet best among the parameters (r = 0.55, P < .001). TNC (AUC = 0.837, 95% CI 0.745-0.906) and HMA (AUC=0.959, 95% CI 0.895-0.989) provided the best predictive ability for sinus tarsi and calcaneofibular bony impingement, respectively. A TNC threshold of 41.2 degrees had a 100% PPV for predicting sinus tarsi impingement, whereas an HMA threshold of 38.1 mm had a 100% PPV for calcaneofibular impingement.

CONCLUSION

This study provides evidence that TNC and HMA measurements made on standing radiographs could be used to indicate potential lateral bony impingement in PCFD. Narrowing of talocalcaneal distance best correlated with abduction deformity of the foot, and the narrowing of calcaneofibular distance was best correlated with valgus hindfoot deformity.

LEVEL OF EVIDENCE

Level III, case control study.

The optimal procedure for lateral column lengthening calcaneal osteotomy according to anatomical patterns of the subtalar joint: an anatomical study in the Chinese population

Background

Lateral column lengthening calcaneal osteotomy is a powerful procedure for correcting forefoot abduction in flatfoot deformity. However, it involves the risk of damaging articular facets of the subtalar joint. The optimal method to avoid violating the subtalar joint during lateral column lengthening remained controversial in published reports, implying that the subtalar joint might present anatomical variations among different nationalities. Therefore, the objective of this study was to perform an anatomical study by targeting the healthy Chinese population for the purpose of identifying the optimal procedure for lateral column lengthening calcaneal osteotomy according to anatomical patterns of the subtalar joint.

Methods

A total of 72 ft from 70 fresh frozen cadavers were obtained from the Department of Anatomy of Central South University. For each foot, soft tissues were surgically removed from the bones, and the calcaneus was completely separated from other bones to recognize the anatomical features of the calcaneus. The distance between the calcaneocuboid joint and the articular facet of the subtalar joint was measured by digital calipers for further analysis.

Results

Out of the 72 ft, 36.1% had separated anterior and middle facets in the calcaneus, and 63.8% had partly or completely fused anterior and middle facets. In the calcanei with discrete facets, the mean distance from the calcaneocuboid joint to the proximal margin of the anterior facet was 12.75 ± 2.10 mm, and the mean width of the separation between the anterior and middle facets was 2.43 ± 1.41 mm. In the calcanei with partly or completely fused anterior and middle facets, the mean width of the narrowest part of the tarsal sinus was 5.81 ± 0.62 mm and 6.25 ± 0.35 mm, respectively.

Conclusions

The anatomy of the subtalar joint presents significant individual variations in the Chinese population. Calcanei with partly or completely fused anterior and middle facets were observed in nearly two thirds of individuals. Since the modified Evans procedure might potentially incur damage to the subtalar joint facets, the Hintermann procedure or other modified extra-articular lateral column lengthening procedures may be more applicable to the Chinese population.

The Effect of Progressive Lateral Column Lengthening in a Novel Stage II-B Flatfoot Cadaveric Model Evaluated Using Software-Guided Radiographic Measurements of Foot Alignment

BACKGROUND

This work used software-guided radiographic measurement to assess the effects of progressive lateral column lengthening (LCL) on restoring alignment in a novel cadaveric model of stage II-B flatfoot deformity.

METHODS

A stage II-B flatfoot was created in 8 cadaveric specimens by transecting the spring ligament complex, anterior deltoid, and interosseous talocalcaneal and cervical ligaments. Weightbearing computed tomographic (WBCT) scans were performed with specimens under 450 N of compressive load in the intact, flat, and 6-, 8-, and 10-mm lateral column-lengthening conditions. Custom software-guided radiographic measurements of the lateral talo-first metatarsal (Meary) angle, anteroposterior talo-first metatarsal angle, naviculocuneiform overlap, and 2 new measures (plantar fascia [PF] distance and angle) were recorded on digitally reconstructed radiographs. Four anonymized analysts performed measurements twice. Intra- and interobserver agreement was assessed using intraclass correlation coefficients (ICCs).

RESULTS

Six-millimeter LCL restored alignment closest to the intact foot in this new cadaveric model, whereas 10-mm lengthening tended toward overcorrection. The PF line displaced laterally in the flatfoot condition, and LCL restored the PF line to a location beneath the talonavicular joint. Interobserver agreement was excellent for PF distance (ICC = 0.99) and naviculocuboid overlap (ICC = 0.91), good for Meary angle (ICC = 0.81) and PF angle (ICC = 0.69), and acceptable for the talonavicular coverage angle (ICC = 0.65).

CONCLUSION

In this stage II-B cadaveric flatfoot model, cervical ligament transection was essential to create deformity after the medial hindfoot ligaments were transected. Software-guided radiographic measurement proved reliable; standardized implementation should improve comparability between studies of flatfoot deformity. The novel PF distance performed most consistently (ICC = 0.99) and warrants further study. With this model, we found that a 6-mm LCL restored alignment closest to the intact foot, whereas 10-mm lengthening tended toward overcorrection.

CLINICAL RELEVANCE

Future joint-sparing flatfoot corrections may consider using a relatively small LCL combined with other bony and/or anatomic ligament/tendon reconstructions.

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.

Subtalar Arthroereisis as an Adjunct Procedure Improves Forefoot Abduction in Stage IIb Adult-Acquired Flatfoot Deformity

BACKGROUND

Our aims were (a) to determine whether subtalar arthroereisis (STA) as adjunct procedure improved radiographic correction of stage IIb adult-acquired flexible flatfoot deformity (AAFD); (b) to assess the STA-related complication rate.

METHODS

A retrospective analysis of 22 feet (21 patients) diagnosed with stage IIb AAFD treated by medializing calcaneal osteotomy (MCO), flexor digitorum longus (FDL) transfer, spring ligament (SL) repair with or without Cotton osteotomy and with or without STA in a single institution was carried out. Seven measurements were recorded on pre- and postoperative (minimum 24 weeks) radiographs by 2 observers and repeated twice by 1 observer. Inter- and intraobserver reliabilities were assessed. The association of demographic (gender, side, age, body mass index) and surgical variables (Cotton, STA) with radiographic change was tested with univariate analysis followed by a multivariable regression model.

RESULTS

Excellent inter- and intraobserver reliabilities were demonstrated for all measurements (intraclass correlation coefficient range, 0.75-0.99). Gender, side, Cotton osteotomy, and STA were included in the multivariable analysis. Regression showed that STA was the only predictor of change in talonavicular coverage angle (TNCA) (R² = 0.31; P = .03) and in calcaneo-fifth metatarsal angle (CFMA) (R² = 0.40; P = .02) on dorsoplantar view. STA was associated to a greater change in TNCA by 10.1° and in CFMA by 5°. Four patients out of 12 STA complained of sinus tarsi pain after STA, and removal of the implant resolved symptoms in 3 of them.

CONCLUSION

In this series, STA as an adjunct procedure to MCO, FDL transfer, SL repair in the treatment of stage IIb AAFD led to improvement in correction of forefoot abduction. STA-related complication and removal rates were 33%.

LEVELS OF EVIDENCE

Level IV: Retrospective cohort study.

Return to Physical Activity Following Flatfoot Reconstruction

BACKGROUND

Progressive collapsing foot deformity (PCFD) is a debilitating condition encompassing several interrelated, progressive deformities requiring a combination of reconstructive procedures. Few studies investigate returns to activity following flatfoot reconstruction, and existing studies only examine 1 or 2 of the numerous procedures employed. This study aims to provide the first generalizable assessment of returns to sports and physical activity following reconstruction surgery in patients with flexible flatfoot deformity.

METHODS

Patients aged 18-60 years who underwent reconstructive surgery between February 16 and May 19 for symptomatic flexible-stage flatfoot deformity were identified by registry review. Eighty-two of 113 eligible patients (73%) were reached at a mean 2.9 years (range, 2.0-5.4) of follow-up with mean age at surgery of 48.9 years (range, 18-59). Returns to physical activity were evaluated with a sports-specific survey. Clinical outcomes were evaluated with Patient-Reported Outcomes Measurement Information System (PROMIS) scores.

RESULTS

Patients reported participation in 21 specific sports and activities. One-fourth (25.6%) of patients (21/82) reported increased difficulty with physical activities postoperatively, 15.9% reported equal difficulty, and 58.5% (48/82) reported decreased difficulty. Median return times were 9-12 months for participation and 12-18 months to reach maximum preoperative participation levels. Improvements in Physical Function (P= .001), Pain Interference (P < .001), Pain Intensity (P <.001), and Global Physical Health (P = .004) were associated with increased satisfaction with respect to sports and physical activities.

DISCUSSION

This study investigated participation in specific sports and physical activities following flatfoot reconstruction. Our findings suggest mixed outcomes, where many patients reported life-changing improvements but many also experienced prolonged pain and difficulty after surgery. Some patients reported increased difficulty or inability to return to their preoperative maximum level of participation, indicating that flatfoot reconstructions can lead to athletic limitations.

CONCLUSION

Although flatfoot reconstruction can be a powerful tool to increase patients' capacity to engage in physical activity, in our cohort many patients had reduced physical activity outcomes.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

The Plantar Fascia Talar Head Correlation: A Radiographic Parameter With a Distinct Threshold to Validate Flatfoot Deformity and Its Corrective Surgery on Conventional Weightbearing Radiographs

BACKGROUND

Corrective surgery for flexible flatfoot deformity (FD) remains controversial, and one of the main reasons for this is the lack of standardized radiographic measurements to define an FD. Previously published radiographic parameters to differentiate between a foot with and without an FD do not have a commonly accepted and distinct threshold.

METHODS

The plantar fascia-talar head correlation (PTC) with its defined threshold was assessed by measuring the distance between the medial border of the plantar fascia and the center of the talar head (DPT) on conventional dorsoplantar and lateral weightbearing radiographs; the authors were blinded to the clinical diagnosis of the 189 patients' first visits. Feet were sorted into groups with and without an FD based on their clinical examination. The effect of operative corrections of FD on the PTC was retrospectively evaluated on an additional 38 patients.

RESULTS

The sensitivity of the PTC was 0.98 (95% CI: 0.9-1) and specificity 0.96 (95% CI: 0.92-0.98), respectively, to identify an FD, consistent with the clinical examination. Thirty-five of 38 surgeries sufficiently corrected the FD and the PTC comparable to that in subjects without an FD. Three corrections with a residual FD did not adequately correct the PTC.

CONCLUSION

The PTC is a reliable radiographic parameter with a distinct threshold that is sensitive and specific for the differentiation of feet with and without an FD including feet with and without residual FD after corrective surgery. The PTC is applicable to monitor the needed intraoperative amount of correction using simulated weightbearing fluoroscopy.

LEVEL OF EVIDENCE

Level III, diagnostic.

Understanding Radiographic Measurements Used in Foot and Ankle Surgery

Given the high volume of patient visits for foot and ankle complaints, developing a systematic approach to evaluation of foot and ankle pathology is important for orthopaedic providers. A thorough evaluation of weight-bearing radiographs is essential to differentiate acute and chronic injury from normal findings to dictate treatment. Radiographic changes and varying degrees of deformity can influence surgical considerations. The purpose of this article was to review and define radiographic measurements relevant to surgical decision making for common foot and ankle pathologies and treatment.

First-Ray Radiographic Changes After Flexible Adult Acquired Flatfoot Deformity Correction

BACKGROUND

Adult acquired flatfoot deformity (AAFD) and hallux valgus (HV) are common foot and ankle deformities. Few studies have reported the changes in radiographic parameters of HV after reconstructive surgery for AAFD. This study aimed to evaluate the changes in radiographic parameters of HV and analyze the risk factors for increased HV after correction of AAFD.

METHODS

Adult patients with flexible AAFD who underwent similar bony procedures including medializing calcaneal osteotomy and Cotton osteotomy were included. Radiographic parameters were measured on weightbearing radiographs preoperatively, postoperatively, and at the final follow-up. Patients were divided into hallux valgus angle (HVA) increased and HVA nonincreased groups; logistic regression analysis was performed to identify risk factors affecting increased HV.

RESULTS

Forty-six feet of 43 patients were included. After AAFD reconstructive surgery, the tibial sesamoid position improved by 1 grade, but the HVA increased 4 degrees in average. Further, 21 of 46 feet (46%) showed an HVA increase ≥5 degrees immediately after AAFD correction surgery. Preoperative talonavicular coverage angle <21.6 degrees was a risk factor associated with HV increase immediately after the surgery.

CONCLUSION

In this case series, using plain radiographs to measure standard parameters of foot alignment, we found the association between AAFD correction and HV deformity measures somewhat paradoxical. Correction of overpronation of the hindfoot and midfoot appears to improve the first metatarsal rotational deformity but may also increase HVA. A lower preoperative talonavicular coverage angle was associated with an increase of the HVA after surgery.

LEVEL OF EVIDENCE

Level IV, case series study.

Adult Acquired Flatfoot Deformity

Adult acquired flatfoot deformity (AAFD) is a condition commonly seen by orthopaedic surgeons. Posterior tibial tendon dysfunction is thought to be the initial pathoanatomic etiology that leads to this deformity. Successful resolution of the pain associated with AAFD can be achievable with nonsurgical methods. Patients who continue to have pain or functional limitations despite nonsurgical treatment can find improvement with appropriately selected surgical interventions. This article addresses new advances in treatment based on the stage of AAFD and will identify areas of continued development with a focus on surgical management. The literature continues to evolve as demonstrated by a recent update regarding the nomenclature and treatment of this condition to progressive collapsing flatfoot deformity. Future goals of research include understanding the natural history of the disease, from asymptomatic to symptomatic, and studying a wide array of newer treatments and implants that have not been prospectively evaluated.

Dynamic medial column stabilization using flexor hallucis longus tendon transfer in the surgical reconstruction of flatfoot deformity in adults

BACKGROUND

A common challenge in flatfoot reconstruction arises when there are multiple locations of collapse within the medial column. An extension of arthrodesis may lead to complications such as stiffness or adjacent joint arthritis. The purpose of this study was to report outcomes of flatfoot reconstruction using the dynamic medial column stabilization (DMCS) technique, which transfers the flexor hallucis longus (FHL) tendon to the first metatarsal base to support the entire medial column.

METHODS

We retrospectively reviewed 14 consecutive patients (14 feet) who underwent DMCS as an adjunct to flatfoot reconstruction. In all cases, a medial displacement calcaneal osteotomy and gastrocnemius recession were performed to address hindfoot valgus deformity and heel cord tightness, respectively. Deformity correction was assessed using preoperative and postoperative weightbearing radiographs. The newly defined metatarsal-cuneiform articular angle (MCAA) and naviculo-cuneiform articular angle (NCAA) were measured to assess correction at each medial column joints. Clinical outcomes included the FFI and VAS scores. Any complications related to the surgery were investigated.

RESULTS

All radiographic parameters significantly improved postoperatively. The sagittal plane correction occurred at all three joints within the medial column. Clinically, both FFI and VAS improved significantly at the final follow-up. One patient developed plantar pain under the first metatarsal head that may have been associated with the overtightening of the transferred tendon.

CONCLUSION

DMCS using FHL tendon transfer to the first metatarsal base was a useful technique for restoring the medial arch and correcting three planar deformities in the setting of flatfoot deformity.

Lateral Column Lengthening For Flexible Adult Acquired Flatfoot: Systematic Review and Meta-Analysis

Flexible Adult Acquired Flatfoot is known to have multiplanar components and can often be a challenge to manage in the clinical setting, with resistance to non-surgical intervention. Lateral Column Lengthening is a favorable option for surgical management, although there are several methods in achieving this, an opening wedge osteotomy of the anterior calcaneus or distraction arthrodesis of the calcaneocuboid joint appear to be the 2 most widespread. In this review we conducted in systematic fashion, analysis of the available literature utilizing the following electronic bibliographic databases, in line with the PRISMA-P checklist: MEDLINE, CINHAL, EMBASE, and the Cochrane library without date restriction up to November 1, 2019. Results identified 21 studies which were assessed for quality using the Coleman methodology score and later evaluated using the PICO analysis system. From 172 participants, we found a higher rate of graft failure with the use of allograft versus autograft, although from a total 355 cases union rates were reported as similar. From the 355, fewer complications with arthrodesis in comparison to osteotomy were reported, including that of post-operative lateral column pain. Surgical intervention using either lateral column procedure yields excellent clinical and radiological results, the literature findings marginally favor the arthrodesis procedure and autograft over allograft. Keeping graft size under 8 mm was found to be clinically important to mitigate overlengthening of the lateral column and biomechanical testing exhibited triangular graft superiority. Where significant correction is required the addition of a medial column stabilization procedure will mitigate post-operative intractable lateral column pain.

I am Afraid of Lateral Column Lengthening. Should I Be?

Lateral column lengthening has long been used in conjunction with other soft tissue and bony procedures to correct the midforefoot abduction seen in class B progressive collapsing foot deformity. The effectiveness of this osteotomy to restore the physiologic shape of the foot has been used by foot and ankle surgeons around the world to provide functional improvement for patients suffering from this disease. The overall low complication rates, low nonunion rates, and improved radiographic and functional outcomes provided by lateral column lengthening make this a valuable option for the treatment of class B progressive collapsing foot deformity.

Spring and Deltoid Ligament Insufficiency in the Setting of Progressive Collapsing Foot Deformity. An Update on Diagnosis and Management

The spring ligament and deltoid ligament are important stabilizers of the medial ankle. Together, they form a complex along the medial ankle and foot that is critical to stability of both the ankle and the medial longitudinal arch. Incompetence of the spring and deltoid ligament is a component of both the early and late stages of progressive collapsing foot deformity. As the importance of this medial ligament complex has been recognized, repair and reconstruction of these ligaments have progressively evolved, initially as separate reconstructions, and more recently as combined techniques.

Surgical Management of Musculotendinous Balance in the Progressive Collapsing Foot Deformity: The Role of Peroneal and Gastrocnemius Contracture

Surgical treatment of progressive collapsing foot deformity (PCFD) relies on understanding the dynamic and deforming musculotendinous structures that contribute to hindfoot valgus, forefoot abduction, forefoot varus, and collapse or hypermobility of the medial column. Equinus commonly is seen in PCFD and consideration should be given to isolated gastrocnemius or Achilles lengthening. Although transfer of the flexor digitorum longus tendon is performed in PCFD attributed to dysfunction and pathology of the posterior tibialis tendon (PTT), retention of PTT is an area for further research. The peroneus brevis, which contributes to hindfoot imbalance in chronic cases, is a possible component of tendon rebalancing.

The Effect of Gastrocnemius Recession and Tendo-Achilles Lengthening on Adult Acquired Flatfoot Deformity Surgery: A Systematic Review

The purpose of this study was to evaluate the available clinical and radiographic evidence for incorporation of a gastrocnemius recession or tendo-Achilles lengthening into the surgical correction of adult acquired flatfoot deformity. A systematic review of the literature was performed using PubMed, Embase, Cochrane, CINAHL, and Google Scholar. Among the relevant articles, the level of evidence and quality was identified using the Methodological Index for Non-Randomized Studies tool. No study explicitly examined whether clinical or radiographic outcomes after adult acquired flatfoot deformity correction are improved when incorporating a gastrocnemius recession or tendo-Achilles lengthening compared with when no such procedure is performed, nor have they directly compared outcomes between 2 procedures. Studies demonstrated an overall improvement in postoperative range of motion and plantar flexion power after gastrocnemius recession, but such findings are hard to separate from the clinical contribution of concomitant corrective procedures to the foot itself. All studies that analyzed anteroposterior talo-calcaneal angle, anteroposterior lateral talo-first metatarsal angle and calcaneal inclination angle revealed improvement of each parameter postoperatively. There were no high-level evidence studies in the literature explicitly quantifying ankle range of motion, plantar flexion power, or radiographic impact of gastrocnemius recession or tendo-Achilles lengthening on adult acquired flatfoot deformity correction. Although gastrocnemius-soleus complex contractures have certainly been demonstrated to coexist with adult acquired flatfoot deformity, support for lengthening procedures is largely based on expert opinion or case series and is difficult to distinguish from the clinical contribution of associated corrective procedures.

Current Concepts in Treatment of Ligament Incompetence in the Acquired Flatfoot

Flatfoot deformity consists of a loss of medial arch, hindfoot valgus, and forefoot abduction. Historically considered a posterior tendon insufficiency, multiple ligament damage and subsequent incompetence explain the different clinical presentations with varying degrees of deformity. When surgery is deemed necessary, depending on the apex of the deformity, skeletal and soft tissue procedures are considered to keep motion and restore function. Osteotomies are considered at every level where an apex of deformity is found. The recently designated tibiocalcaneonavicular ligament comprises the older superficial and deep deltoid and spring ligaments; its repair or reconstruction should be considered in most flatfoot cases.

[Adult Acquired Flatfoot Deformity: Diagnosis and Surgical Treatment]

The adult acquired flatfoot is a deformity with slow progression, which may leads to pain and restrictions of activities of daily living if untreated. Various treatment strategies, depending on the clinical and radiological presentation, exist. Therefore, an individual therapy approach is necessary for optimal treatment. This article covers etiopathologic aspects, conservative and operative treatments as well as postoperative mobilization and rehabilitation.

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.

Consensus for the Indication of Lateral Column Lengthening in the Treatment of Progressive Collapsing Foot Deformity

RECOMMENDATION

Progressive collapsing foot deformity (PCFD) is a complex 3D deformity with varying degrees of hindfoot valgus, forefoot abduction, and midfoot supination. Although a medial displacement calcaneal osteotomy can correct heel valgus, it has far less ability to correct forefoot abduction. More severe forefoot abduction, most frequently measured preoperatively by assessing talonavicular coverage on an anteroposterior (AP) weightbearing conventional radiographic view of the foot, can be more effectively corrected with a lateral column lengthening procedure than by other osteotomies in the foot. Care must be taken intraoperatively to not overcorrect the deformity by restricting passive eversion of the subtalar joint or causing adduction at the talonavicular joint on simulated AP weightbearing fluoroscopic imaging. Overcorrection can lead to lateral column overload with persistent lateral midfoot pain. The typical amount of lengthening of the lateral column is between 5 and 10 mm.

LEVEL OF EVIDENCE

Level V, consensus, expert opinion.

CONSENSUS STATEMENT ONE

Lateral column lengthening (LCL) procedure is recommended when the amount of talonavicular joint uncoverage is above 40%. The amount of lengthening needed in the lateral column should be judged intraoperatively by the amount of correction of the uncoverage and by adequate residual passive eversion range of motion of the subtalar joint.Delegate vote: agree, 78% (7/9); disagree, 11% (1/9); abstain, 11% (1/9).(Strong consensus).

CONSENSUS STATEMENT TWO

When titrating the amount of correction of abduction deformity intraoperatively, the presence of adduction at the talonavicular joint on simulated weightbearing fluoroscopic imaging is an important sign of hypercorrection and higher risk for lateral column overload.Delegate vote: agree, 100% (9/9); disagree, 0%; abstain, 0%.(Unanimous, strongest consensus).

CONSENSUS STATEMENT THREE

The typical range for performing a lateral column lengthening is between 5 and 10 mm to achieve an adequate amount of talonavicular coverage.Delegate vote: agree, 100% (9/9); disagree, 0%; abstain, 0%.(Unanimous, strongest consensus).

Titrating the Amount of Bony Correction in Progressive Collapsing Foot Deformity

RECOMMENDATION

There is evidence indicating that the amount of bony correction performed in the setting of progressive collapsing foot deformity reconstructive surgery can be titrated within a recommended range for a variety of procedures. The typical range when performing a medial displacement calcaneal osteotomy should be 7 to 15 mm of medialization of the tuberosity. The typical range when performing an Evans lateral column lengthening should be 5 to 10 mm of a laterally based wedge in the anterior calcaneus. The typical range when performing a plantarflexion opening wedge osteotomy of the medial cuneiform (Cotton) osteotomy should be 5 to 10 mm of a dorsal wedge.

LEVEL OF EVIDENCE

Level V, consensus, expert opinion.

Outcomes of Idiopathic Flexible Flatfoot Deformity Reconstruction in the Young Patient

Background:

Operative correction of flatfoot deformity has been well studied in the older population. There is a subset of younger patients without congenital foot deformity that also develop a collapsing flatfoot. However, assessment of outcomes across age groups is limited, especially in the young demographic. The purpose of our study was to compare operative outcomes of flatfoot reconstruction between these 2 age groups.

Methods:

Seventy-six feet (41 left, 35 right) in 71 patients who underwent flexible flatfoot reconstruction were divided into 2 groups based on age: ≤30 years (n = 22) and >30 years (n = 54). Exclusion criteria included congenital causes of flatfoot (tarsal coalition, vertical talus, overcorrected clubfoot). Average age was 20.8 years (range, 14-30) and 55.4 years (range, 35-74) in the younger and older cohorts, respectively. Preoperative and minimum 2-year postoperative Patient-Reported Outcomes Measurement Information Systems (PROMIS) scores were compared. Five radiographic parameters were assessed pre- and postoperatively: talonavicular coverage angle, lateral talo–first metatarsal angle, lateral talocalcaneal angle, calcaneal pitch, and hindfoot moment arm. Procedures performed and incidence of minor (removal of symptomatic hardware) and major (revision) reoperations were compared.

Results:

Younger patients were less likely to undergo flexor digitorum longus transfer, first tarsometatarsal fusion, spring ligament repair, and posterior tibial tendon repair (all P < .05). Both younger and older cohorts demonstrated significant improvement in multiple PROMIS domains at an average follow-up of 30.6 (range, 24-44) and 26.8 (range, 24-45) months, respectively ( P = .07). Younger patients demonstrated significantly higher pre- and postoperative Physical Function (mean difference postoperatively, 4.6; 95% confidence interval, 1.5-7.8; P = .03). There were no differences in radiographic parameters postoperatively. There were 8 (36.4%) reoperations (all minor) in the younger group, and 21 (38.9%) reoperations (6 major, 15 minor) in the older group ( P = .84).

Conclusion:

Our data suggest that age may play a role in clinical outcomes, procedures indicated, and subsequent corrective reoperations. Younger patients maintained greater physical function with comparable radiographic correction, with less frequent indication for tendon transfers, arthrodesis, and additional corrective surgeries.

Level of Evidence:

Level III, retrospective comparative study.

Three-Dimensional Biometric Weightbearing CT Evaluation of the Operative Treatment of Adult-Acquired Flatfoot Deformity

BACKGROUND

Assessment of operative correction of adult-acquired flatfoot deformity (AAFD) has been traditionally performed by clinical evaluation and conventional radiographic imaging. Previously, a 3-dimensional biometric weightbearing computed tomography (WBCT) tool, the foot ankle offset (FAO), has been developed and validated in assessing hindfoot alignment. The purpose of this study was to investigate the role of FAO in evaluating operative deformity correction in AAFD.

METHODS

In this prospective comparative study, 19 adult patients (20 feet) with stage II (flexible) flatfoot deformity underwent preoperative and postoperative standing WBCT examination at mean 19 months (range, 6-24) after surgery. Three-dimensional coordinates of the foot tripod and center of the ankle joint were acquired by 2 independent and blinded observers. These coordinates were used to calculate the FAO using dedicated software, and subsequently compared pre- and postoperatively. The FAO is a previously validated biometric measurement that represents centering of the foot tripod as well as hindfoot alignment, with a normal mean FAO of 2.3% ± 2.9%. In addition, Patient Reported Outcomes Measurement Information System (PROMIS) clinical outcomes scores were compared pre- and postoperatively with a mean follow-up of 22.6 months (range, 14-37).

RESULTS

There was significant correction of flatfoot deformity from a mean preoperative FAO of 9.8% to a mean postoperative value of 1.3% (P < .001). Additionally, there was statistically significant improvement in all PROMIS domains (P < .05), except depression, at an average follow-up of 22.6 months. Spring ligament reconstruction was the only procedure associated with a significant correction in FAO (P = .0064).

CONCLUSION

The FAO was a reliable and sensitive tool that was used to evaluate preoperative deformity as well as postoperative correction, with patients demonstrating both significant improvement in FAO as well as patient-reported outcomes. These findings demonstrate the role for biometric 3-dimensional WBCT imaging in assessing operative correction after flatfoot reconstruction, as well as the potential role for operative planning to address preoperative deformity.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Multiplanar Semiautomatic Assessment of Foot and Ankle Offset in Adult Acquired Flatfoot Deformity

BACKGROUND

Semiautomatic 3-dimensional (3D) biometric weightbearing computed tomography (WBCT) tools have been shown to adequately demonstrate the relationship between the center of the ankle joint and the tripod of the foot. The measurement of the foot and ankle offset (FAO) represents an optimized biomechanical assessment of foot alignment. The objective of this study was to evaluate the correlation between FAO and traditional adult acquired flatfoot deformity (AAFD) markers, measured in different planes. We hypothesized that the FAO would significantly correlate with other radiographic markers of pronounced AAFD.

METHODS

In this retrospective comparative study, we included 113 patients with stage II AAFD, 43 men and 70 women, mean age of 53.5 (range, 20-86) years. 3D coordinates (x, y, and z planes) of the foot tripod (most plantar voxel of the first and fifth metatarsal heads, and calcaneal tuberosity) and the center of the ankle joint (most proximal and central voxel of the talar dome) were assessed by 2 blinded and independent fellowship-trained orthopedic foot and ankle surgeons. The FAO was automatically calculated using the 3D coordinates by dedicated software. Multiple WBCT parameters related to the severity of the deformity in the coronal, sagittal, and transverse planes were manually measured.

RESULTS

We found overall good to excellent intra- (range, 0.75-0.99) and interobserver (range, 0.73-0.99) reliability for manual AAFD measurements. FAO semiautomatic measurements demonstrated excellent intra- (0.99) and interobserver (0.99) reliabilities. Hindfoot moment arm (HMA) (P < .00001), subtalar horizontal angle (P < .00001), talonavicular coverage angle (P = .00004), and forefoot arch angle (P = .0001) were the only variables found to significantly influence and correlate with FAO measurements, with an R² value of 0.79. An HMA value of 19.8 mm was found to be a strong threshold predictor of increased values of FAO, with mean values of FAO of 6.5 when the HMA was lower than 19.8 mm and 14.6 when the HMA was equal to or higher than 19.8 mm.

CONCLUSION

We found that 3D WBCT semiautomatic measurements of FAO significantly correlated with some traditional markers of pronounced AAFD. Measurements of FAO were also found to be slightly more reliable than the manual measurements. The FAO offers a simple and more complete biomechanical and multiplanar assessment of the AAFD, representing in a single measurement the 3D components of the deformity.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Analysis of biomechanical stresses caused by hindfoot joint arthrodesis in the treatment of adult acquired flatfoot deformity: A finite element study

BACKGROUND

Treatments of adult acquired flatfoot deformity in early stages (I-IIa-IIb) are focused on strengthening tendons, in isolation or combined with osteotomies, but in stage III, rigidity of foot deformity requires more restrictive procedures such as hindfoot joint arthrodesis. Few experimental studies have assessed the biomechanical effects of these treatments, because of the difficulty of measuring these parameters in cadavers. Our objective was to quantify the biomechanical stress caused by both isolated hindfoot arthrodesis and triple arthrodesis on the main tissues that support the plantar arch.

METHODS

An innovative finite element model was used to evaluate some flatfoot scenarios treated with isolated hindfoot arthrodesis and triple arthrodesis.

RESULTS AND CONCLUSIONS

When arthrodeses are done in situ, talonavicular seems a good option, possible superior to subtalar and at least equivalent to triple. Calcaneocuboid arthrodesis reduces significantly both fascia plantar and spring ligament stresses but concentrates higher stresses around the fused joint.

Effectiveness of subtalar arthroereisis with endorthesis for pediatric flexible flat foot: a retrospective cross-sectional study with final follow up at skeletal maturity

BACKGROUND

Pediatric flexible flatfoot is sometimes asymptomatic but it can rarely cause physical impairment, pain, and difficulty walking. We evaluated the radiographic effectiveness of intervention of subtalar arthroereisis with endorthesis for pediatric flexible flatfoot with final follow-up at skeletal maturity.

METHODS

This is a retrospective cross-sectional study. 56 consecutive patients (112 feet) who underwent surgical treatment with subtalar arthroereisis for pediatric flexible flatfoot (mean age at final follow-up 15.5±1.2 years, 39.3% female) were enrolled. All the radiographic studies were performed in the hospital. Radiographs (standard weight-bearing radiographs of the foot with anteroposterior and lateral view) were used to measure lateral talocalcaneal angle (LTC), calcaneal pitch angle (CP), Meary's angle (MA), anteroposterior talonavicular angle (APTN), talonavicular uncoverage percent (TNU). Minimum follow-up was 18 months. Measures were assessed pre-operatively and at the final follow-up. Clinical and functional parameters were assessed at the final follow-up.

RESULTS

Children who underwent surgical treatment with subtalar arthroereisis for pediatric flexible flatfoot exhibited a statistically significant improvement in all radiographic measurement parameters at the last follow-up at skeletal maturity (all, p<0.004). Mean follow-up was 40.1±23.6months. Clinical parameters were not correlated with the foot radiographic parameters at follow up period.

CONCLUSIONS

Our results suggest that endorthesis in pediatric flexible flatfoot was effective for improving radiographic parameters at skeletal maturity. The amount of the morphologic correction at the end of the skeletal growth should be expected mainly for lateral tarso-metatarsal alignment and talo-navicular congruency (MA, APTN, TNU).

LEVEL OF EVIDENCE

Level III, retrospective study.

Outcomes of Reconstruction of the Flexible Adult-acquired Flatfoot Deformity

Reconstruction of the flexible adult-acquired flatfoot deformity (AAFD) is controversial, and numerous procedures are frequently used in combination, including flexor digitorum longus transfer, medializing calcaneal osteotomy (MCO), heel cord lengthening/gastrocnemius recession, lateral column lengthening (LCL), Cotton osteotomy or first tarsometatarsal fusion, and spring ligament reconstruction. This article summarizes recent studies demonstrating that patients have significant improvements after operative treatment of flexible AAFD. It reviews current literature on clinical and radiographic outcomes of the MCO, LCL, and Cotton osteotomies. The authors describe how this information can be used in surgical decision making in order to tailor operative treatment to an individual patient's deformity.

Three-Dimensional Morphometric Modeling Measurements of the Calcaneus in Adults with Stage IIB Posterior Tibial Tendon Dysfunction: A Pilot Study

Background: The pathophysiology of adult-acquired flatfoot deformity (AAFD) is not fully explained by degeneration of the posterior tibial tendon alone. While a shortened or dysplastic lateral column has been implicated in flatfoot deformity in pediatrics, there is no study that has quantified the degree of dysplasia in adults with a stage IIb flatfoot deformity, or if any exists at all. Methods: An institutional radiology database was queried for patients with posterior tibial tendon dysfunction (PTTD) who had computed tomography (CT) performed. Controls were patients receiving CT scan for an intra-articular distal tibia fracture without preexisting foot or calcaneal pathology. Clinical notes, physical examination, and weightbearing radiographs were used to find patients that met clinical criteria for stage IIb PTTD. Morphometric measurements of the calcanei were performed involving the length of the calcaneal axis (LCA), height of the anterior process (HAP), and length of the anterior process (LAP). All measurements were performed independently by separate observers, with observers blinded to group assignment. We considered a difference of ±4 mm as our threshold. Results: 7 patients and 7 controls were available for reconstruction and analysis. On average, the LCA was 3.1 mm shorter in patients with stage IIb PTTD compared with controls (P < .05). The LAP was shorter in PTTD patients compared with controls 3.4 mm (P < .001). Conclusions: Our results support the hypothesis that the calcaneus of adult patients with stage IIb AAFD is dysplastic when compared with healthy controls, which further supports the utility of lateral column lengthening. Levels of Evidence: Level III: Case-control study.

Outcomes of the Extended Z-Cut Osteotomy for Correction of Adult Acquired Flatfoot Deformity

BACKGROUND

Medial displacement calcaneus tuberosity osteotomy and anterior process lengthening calcaneus osteotomy are traditional single-plane osteotomy techniques used in adult acquired flatfoot deformity reconstruction. More recently, 3-plane step-cut osteotomies were described for each of these and shown to offer improved rotational stability via the horizontal limb. However, a major technical challenge is achieving a sufficiently long horizontal limb to correct deformity through lengthening without losing bony apposition. Combining the anterior process and tuberosity step-cuts using an elongated horizontal limb alleviates this technical challenge, creates a very large surface area for bony healing, and utilizes a single incision. We hypothesized that the Z-cut osteotomy would achieve clinical and radiographic flatfoot deformity correction with a high union rate.

METHODS

This was an institutional review board-approved retrospective study of 16 patients who underwent Z-cut osteotomy for the treatment of moderate to severe symptomatic adult acquired flatfoot deformity, stage IIA/B. The mean radiographic follow-up was 8.8 months, while the mean clinical follow-up was 2.36 years. Radiographic correction was assessed via weightbearing radiographs taken preoperatively and at a mean of 26 ± 2 weeks postoperatively. Measurements included Meary's angle (talo-first metatarsal angle), talonavicular (TN) joint uncoverage percentage, TN incongruency angle, medial cuneiform to fifth metatarsal height, and calcaneal pitch. Union rates and clinical outcomes via the Foot Function Index (FFI) score were assessed preoperatively and at a mean of 29 months following surgery. Paired t test was used to compare both clinical and radiographic outcomes with statistical significance set at P < .05.

RESULTS

Fifteen of 16 patients returned an FFI questionnaire with a mean improvement of 52.1 to 10.3 (P = .002). The calcaneal pitch improved from 12.7 to 15.2 degrees (P = .002), the medial cuneiform-fifth metatarsal distance improved from 12.8 to 18.5 mm (P = .002), the TN coverage angle improved from 21.3 to 9.1 degrees (P < .001), the TN uncoverage percentage improved from 32.9% to 20.3% (P < .001), and the TN incongruency angle improved from 41.4 to 19.9 degrees (P < .001). Deformity correction was well maintained in 13 of 16 patients at final follow-up. The union rate of the osteotomy was 100%. Three patients had symptomatic hardware initially; 1 patient required removal of hardware. One patient developed a superficial infection that cleared. Another patient developed peroneal tendonitis, which resolved with corticosteroid injection.

CONCLUSION

The Z-cut osteotomy is a novel, technically simplified, single-incision, single-osteotomy alternative to the previously described double calcaneus osteotomy techniques for reconstructing flexible moderate to severe adult acquired flatfoot deformity that offers comparable short-term clinical and radiographic outcomes with acceptably low complications.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Postoperative Medial Cuneiform Position Correlation With Patient-Reported Outcomes Following Cotton Osteotomy for Reconstruction of the Stage II Adult-Acquired Flatfoot Deformity

BACKGROUND

Residual supination of the midfoot during reconstruction of the stage II adult-acquired flatfoot deformity (AAFD) is often addressed with a medial cuneiform (Cotton) osteotomy after adequate correction of the hindfoot valgus deformity. The purpose of this study was to determine if there was a correlation between postoperative alignment of the medial cuneiform and patient-reported outcomes.

METHODS

Sixty-three feet in 61 patients with stage II AAFD who underwent a Cotton osteotomy as part of a flatfoot reconstruction were included in the study. Radiographic angles were measured on weightbearing lateral radiographs at a minimum of 40 weeks postoperatively. Pearson's correlation analysis was used to determine if there was an association between postoperative radiographic angles and Foot and Ankle Outcome Score (FAOS) at a minimum of 24 months postoperatively. Patients were also divided into mild plantarflexion (cuneiform articular angle [CAA] ≥-2 degrees) and moderate plantarflexion (CAA <-2 degrees) groups to evaluate for differences in clinical outcomes.

RESULTS

Postoperative CAA was significantly positively correlated with the postoperative FAOS symptoms ( r = .27, P = .03), daily activities ( r = .29, P = .02), sports activities ( r = .26, P = .048), and quality of life ( r = .28, P = .02) subscales. Patients in the mild plantarflexion group had statistically and clinically better outcomes compared with the moderate plantarflexion group in the FAOS symptoms ( P = .04), daily activities ( P = .04), and sports activities ( P = .01) subscales.

CONCLUSIONS

Our study suggests that the surgeon should avoid excessive plantarflexion of the medial cuneiform and use the Cotton osteotomy judiciously as part of a flatfoot reconstruction for stage II AAFD.

LEVEL OF EVIDENCE

Level III, comparative series.

Severe Flexible Pes Planovalgus Deformity Correction Using Trabecular Metallic Wedges

BACKGROUND:

Lateral column lengthening and plantarflexion dorsal opening wedge osteotomy of the medial cuneiform are 2 commonly used procedures to address the deformity seen in severe flexible pes planovalgus deformity. Traditionally, iliac crest allograft or autograft has been used to fill the osteotomy sites. Porous metallic wedges can be used as an alternative to avoid the concerns associated with both autograft and allograft.

METHODS:

We performed a retrospective review of patients who had corrective osteotomies utilizing metallic wedges to address flexible pes planovalgus with at least 2 years of follow-up data. Preoperative radiographic measurements (anteroposterior [AP] and talo-first metatarsal angle, calcaneal pitch, talocalcaneal angle, and talonavicular uncoverage angle) and functional scores (visual analog scale [VAS] pain, Foot and Ankle Ability Measure [FAAM] Activities of Daily Living [ADL], FAAM Sports) were compared to postoperative radiographic measurements and functional scores.

RESULTS:

There were statistically significant improvements in all radiographic parameters and functional scores. Two nonunions were seen, one of which healed with revision surgery while the other was asymptomatic. At the time of last radiographic follow-up, there were no recurrences of deformity or collapse.

CONCLUSION:

Porous metallic wedges offer an attractive alternative to autograft and/or allograft in the setting of corrective osteotomies for severe flexible pes planovalgus. Patients who underwent corrective osteotomies using these wedges demonstrated reliable, effective, and stable radiographic correction as well as significant improvements in function and pain.

LEVEL OF EVIDENCE:

Level IV, case series.

Adult-Acquired Flatfoot Deformity

Adult-acquired flatfoot deformity (AAFD) comprises a wide spectrum of ligament and tendon failure that may result in significant deformity and disability. It is often associated with posterior tibial tendon deficiency (PTTD), which has been linked to multiple demographic factors, medical comorbidities, and genetic processes. AAFD is classified using stages I through IV. Nonoperative treatment modalities should always be attempted first and often provide resolution in stages I and II. Stage II, consisting of a wide range of flexible deformities, is typically treated operatively with a combination of soft tissue procedures and osteotomies. Stage III, which is characterized by a rigid flatfoot, typically warrants triple arthrodesis. Stage IV, where the flatfoot deformity involves the ankle joint, is treated with ankle arthrodesis or ankle arthroplasty with or without deltoid ligament reconstruction along with procedures to restore alignment of the foot. There is limited evidence as to the optimal procedure; thus, the surgical indications and techniques continue to be researched.

Porous Titanium Wedges in Lateral Column Lengthening for Adult-Acquired Flatfoot Deformity

Lateral column lengthening (LCL) is a common procedure for reconstruction of stage II flexible adult-acquired flatfoot deformity (AAFD). The recent development of porous titanium wedges for this procedure provides an alternative to allograft and autograft. The purpose of this study was to report radiographic and clinical outcomes achieved with porous titanium wedges in LCL. A retrospective analysis of 34 feet in 30 patients with AAFD that received porous titanium wedges for LCL from January 2011 to October 2014. Deformity correction was assessed using both radiographic and clinical parameters. Radiographic correction was assessed using the lateral talo-first metatarsal angle, the talonavicular uncoverage percentage, and the first metatarsocuneiform height. The hindfoot valgus angle was measured. Patients were followed from a minimum of 6 months up to 4 years (mean 16.1 months). Postoperative radiographs demonstrated significant correction in all 3 radiographic criteria and the hindfoot valgus angle. We had no cases of nonunion, no wedge migration, and no wedges have been removed to date. The most common complication was calcaneocuboid joint pain (14.7%). Porous titanium wedges in LCL can achieve good radiographic and clinical correction of AAFD with a low rate of nonunion and other complications.

LEVELS OF EVIDENCE

Level IV: Case series.

Contribution of Medial Cuneiform Osteotomy to Correction of Longitudinal Arch Collapse in Stage IIb Adult-Acquired Flatfoot Deformity

Background Residual forefoot supination after correcting the hindfoot in stage IIb adult-acquired flatfoot deformity can be addressed with a dorsal opening wedge medial cuneiform (Cotton) osteotomy. The amount of correction is generally judged clinically, and there currently are no preoperative guides that can predict the size of graft needed. The aim of this study was to evaluate the correlation between patient and operative factors and the correction achieved with the Cotton osteotomy.

METHODS

Seventy-nine feet in 74 patients undergoing Cotton osteotomy as part of flatfoot reconstruction were reviewed retrospectively. Preoperative and minimum 40-week postoperative lateral foot weightbearing radiographs were compared to assess correction of longitudinal arch collapse as measured by 13 radiographic parameters, with particular emphasis on the cuneiform articular angle (CAA). Additional demographic and intraoperative variables analyzed for association with radiographic change included age, gender, body mass index, amounts and graft types of Cotton osteotomy and lateral column lengthening, and amount of medializing calcaneal osteotomy. A multivariate linear regression model was developed for each variable found to be significant in univariate analysis.

RESULTS

The Cotton osteotomy graft size was significantly associated with changes in the CAA ( P < .001), calcaneal pitch ( P = .03), lateral talonavicular Cobb angle ( P = .03), and lateral naviculomedial cuneiform Cobb angle ( P = .03). The Cotton graft size was the only factor found to significantly predict a change in the CAA in the final linear regression model ( P < .001, R² = 0.27), with each millimeter of Cotton corresponding to a 2.1-degree decrease of the CAA.

CONCLUSION

Correction of longitudinal arch collapse, as measured by the CAA, was primarily influenced by the size of the graft used for the Cotton osteotomy in a linear fashion. The preoperative CAA may help surgeons titrate the proper amount of graft placed intraoperatively.

LEVEL OF EVIDENCE

Level IV, Retrospective Case Series.

Double calcaneal osteotomy for severe adolescent flexible flatfoot reconstruction

Background

The timing and strategy of treatment for flatfoot still remain controversial. It is a difficult problem when facing severe adolescent flexible flatfoot because a single procedure cannot realign flatfoot deformity effectively.

Methods

We reviewed 13 adolescent flexible flatfoot patients who underwent double calcaneal osteotomy during May 2012 to June 2015. The mean age of patients was 15.2 ± 1.8 (range, 10–18) years. The American Orthopaedic Foot and Ankle Society Ankle-Hindfoot (AOFAS-AH) scores and SF-36 score were adopted to evaluate the preoperative and postoperative functions of the foot. Changes of hindfoot valgus angles, talonavicular uncoverage angles on AP view and talo-first metatarsal angles, and talar pitch angles and calcaneal pitch angles on the lateral film before and after surgery were measured.

Results

All 13 patients (15 ft) were followed. The mean duration of follow-up was 34.5 ± 15.7 (range, 21–60) months. The hindfoot valgus angle improved from 16.5 ± 4.1 to 2.9 ± 1.6. On the foot AP view, the mean preoperative and postoperative talonavicular coverage angles were 24.9 ± 8.5 and 6.5 ± 3.6. On the lateral view of the foot, the average preoperative and postoperative talo-first metatarsal angles were 18.1 ± 5.5 and 4.9 ± 4.4. The mean preoperative and postoperative talar pitch angles were 36.4 ± 4.7 and 24.0 ± 5.6. The AOFAS-AH score improved from 68.9 ± 12.3 preoperatively to 94.6 ± 3.9 postoperatively.

Conclusion

With additional procedures, double calcaneal osteotomy was an effective method for severe adolescent flexible flatfoot.

Overcorrected Flatfoot Reconstruction

The overcorrected flatfoot reconstruction is a less common but often difficult sequelae of surgical treatment of the adult acquired flatfoot deformity. Understanding the patient's symptoms and how they correlate to the procedures performed during the index surgery are paramount to determining the appropriate course of treatment. Patients' symptoms may resemble those seen in the cavovarus foot condition, often secondary to overlengthening of the lateral column or excessive displacement of the calcaneal tuberosity. Osteotomies of the calcaneus, midfoot, and often the first metatarsal may be sufficient to revise the overcorrection. However, hindfoot and/or midfoot arthrodesis may be required in more severe or rigid cases.

In Vivo Plantar Pressures in Adult-Acquired Flatfoot Compared to Control Using an Intraoperative Pedobarographic Device

BACKGROUND

Intraoperative pedobarography has the potential to aid surgical decisions, but no parameters exist to guide its use.

QUESTIONS/PURPOSES

This study compared supine plantar pressures between flatfoot patients and controls using a previously validated intraoperative pedobarographic device and examined associations between supine, walking, and standing plantar pressures.

METHODS

Ten preoperative patients with stage II adult-acquired flatfoot deformity (AAFD) were compared to ten healthy controls. Supine plantar pressures were assessed using the pedobarographic device. Standing and walking plantar pressures were assessed with an EMED-XT sensor array (Novel). Maximum force (MF) and peak pressure (PP) were calculated for nine anatomical foot regions adjusting for age and BMI.

RESULTS

No differences in plantar pressures were found between flatfoot patients and controls in the supine or standing positions. During walking, flatfoot patients had greater MF of the first, second, and third metatarsals (p ≤ 0.018) and greater PP of the first and second metatarsals than controls (p ≤ 0.010). Supine MF and PP were both strongly positively correlated with their respective pressure measurements for both standing and walking in multiple foot regions (p ≤ 0.05, all analyses). Correlations in the first metatarsal region were generally weak and not statistically significant.

CONCLUSION

This device did not show differences in supine plantar pressures of flatfoot patients and healthy subjects, highlighting the limitations of intraoperative devices in guiding flatfoot correction. The differences between flatfoot and controls during walking and the correlations between supine and walking conditions suggest that dynamic plantar pressures are a more useful parameter in guiding flatfoot reconstruction.

Biomechanical Analysis of Cuboid Osteotomy Lateral Column Lengthening for Stage II B Adult-Acquired Flatfoot Deformity: A Cadaveric Study

Purpose. To investigate the effect of cuboid osteotomy lateral column lengthening (LCL) for the correction of stage II B adult-acquired flatfoot deformity in cadaver. Methods. Six cadaver specimens were loaded to 350 N. Flatfoot models were established and each was evaluated radiographically and pedobarographically in the following conditions: (1) intact foot, (2) flatfoot, and (3) cuboid osteotomy LCL (2, 3, 4, and 5 mm). Results. Compared with the flatfoot model, the LCLs showed significant correction of talonavicular coverage on anteroposterior radiographs and talus-first metatarsal angle on both anteroposterior and lateral radiographs (p < .05). Compared with the intact foot, the above angles of the LCLs showed no significant difference except the 2 mm LCL. In terms of forefoot pressure, medial pressure of the 2 mm LCL (p = .044) and lateral pressure of the 3, 4, and 5 mm LCLs showed statistical differences (p < .05), but lateral pressure of the 3 mm LCL was not more than the intact foot as compared to the 4 and 5 mm LCLs, which was less than medial pressure. Conclusion. Cuboid osteotomy LCL procedure avoids damage to subtalar joint and has a good effect on correction of stage II B adult-acquired flatfoot deformity with a 3 mm lengthening in cadavers.

Adult-acquired flatfoot deformity

Adult-acquired flatfoot deformity (AAFD) is a known and recognized cause of pain and disability. Loss of PTT function is the most important contributor to AAFD, and its estimated prevalence is thought to be over 3%. This review aims to summarize the current literature and encompass recent advances regarding AAFD.

Calcaneal Z Lengthening Osteotomy Combined With Subtalar Arthroereisis for Severe Adolescent Flexible Flatfoot Reconstruction

BACKGROUND

The timing and strategy for operative treatment of flatfoot are still controversial. The purpose of this study was to evaluate clinical outcomes and radiographic changes following calcaneal Z osteotomy combined with subtalar arthroereisis for severe adolescent flexible flatfoot.

METHODS

Data were analyzed for 16 patients (20 feet) who had flatfoot without tibialis posterior tendon dysfunction and were treated by calcaneal Z osteotomy combined with arthroereisis between October 2011 and February 2015. The mean age of patients at the time of surgery was 12.8 ± 1.4 years (range, 10-14 years). Preoperative and postoperative measurements included changes in hindfoot valgus angles; changes in talonavicular uncoverage angles on anteroposterior (AP) radiographic view; and changes in talo-first metatarsal angles, talar pitch angles, and calcaneal pitch angles on lateral radiographic view. The American Orthopaedic Foot & Ankle Society Ankle-Hindfoot Score (AOFAS-AH) was used to assess foot function. The mean follow-up was 18.9 ± 6.9 months (range, 13-33 months).

RESULTS

The hindfoot valgus angle improved from 14.9 ± 4.2 degrees to 2.3 ± 1.7 degrees. On the AP view, the preoperative and postoperative talonavicular uncoverage angles were 30.5 ± 9.4 degrees and 9.8 ± 4.8 degrees, respectively. On lateral radiographs, the preoperative talo-first metatarsal angle, talar pitch angle, and calcaneal pitch angle were -22.1 ± 7.9 degrees, 36.1 ± 4.4 degrees, and 14.4 ± 4.0 degrees, respectively. Postoperative lateral radiographs demonstrated talo-first metatarsal angle, talar pitch angle, and calcaneal pitch angle of -6.2 ± 4.7 degrees, 27.3 ± 4.9 degrees, and 19.0 ± 4.3 degrees, respectively. The AOFAS-AH score improved from 66.8 ± 24.1 preoperatively to 96.5 ± 3.4 postoperatively.

CONCLUSIONS

For adolescents with flatfoot, calcaneal Z osteotomy combined with subtalar arthroereisis provided satisfactory results.

LEVEL OF EVIDENCE

Level IV, retrospective case series.