Adult Acquired Flatfoot Deformity Research Articles

Advancing Adult-Acquired Flatfoot Deformity Treatment: Enhanced Biomechanical Support Through Graphene Oxide-Integrated Bioengineered Grafts Tested In Silico

Adult-Acquired Flatfoot Deformity (AAFD) is a progressive orthopedic condition causing the collapse of the foot’s medial longitudinal arch, often linked with injuries to the plantar arch’s passive stabilizers, such as the spring ligament (SL) and plantar fascia. Conventional treatment typically involves replacing the SL with synthetic material grafts, which, while providing mechanical support, lack the biological compatibility of native ligaments. In response to this shortcoming, our study developed an electrospun, twisted polymeric graft made of polycaprolactone (PCL) and type B gelatin (GT), enhanced with graphene oxide (GO), a two-dimensional nanomaterial, to bolster biomechanical attributes. The addition of GO aimed to match the native ligamentous tissue’s mechanical strength, with the PCL-GT-GO 2.0% blend demonstrating an optimal Young’s modulus of 240.75 MPa. Furthermore, the graft showcased excellent biocompatibility, evidenced by non-hemolytic reactions, suitable wettability and favorable platelet aggregation—essential features for promoting cell adhesion and proliferation. An MTT assay revealed cell viability exceeding 80% after 48 h of exposure, highlighting the potential of the graft as a regenerative scaffold for affected ligaments. Computational modeling of the human foot across various AAFD stages assessed the graft’s in situ performance, with the PCL-GT-OG 2.0% graft efficiently preventing plantar arch collapse and offering hindfoot pronator support. Our study, based on in silico simulations, suggests that this bioengineered graft holds significant promise as an alternative treatment in AAFD surgery, marking a leap forward in the integration of advanced materials science for enhanced patient care.

HyProCure for Flatfoot Deformity: A Clinical Characteristics Analysis in China.

Flatfoot is a common foot disorder involving progressive foot deformity of the three-dimensional structures of the forefoot, midfoot, and hindfoot. Currently, Chinese surgeons and patients favor subtalar arthroereisis (SA) due to its minimally invasive and low-damage characteristics. HyProCure device is widely used. However, there is limited analysis of large sample sizes. This study utilized statistical evaluation with a large sample size to analyze clinical characteristics trends of SA for flatfoot, including baseline indicators, selection of HyProCure size and surgical strategy, complications, and implant removal. This study will enhance the understanding of SA in China. A retrospective analysis of 732 patients (1008 ft) who underwent SA from June 2015 to June 2023, with 509 pediatric and adolescent patients (772 ft) and 223 adult patients (236 ft). Based on the patient's age, patients aged ≤ 18 were included in the children and adolescent group, while adult acquired flatfoot deformity (AAFD) patients aged > 18 were included in the adult group. General data was collected, including patient sex, age, side, body mass index (BMI), surgery date, HyproCure size, and surgical data, and trends were analyzed. Postoperative complications and HyProCure removal were collected as outcome measures during follow-up. The age of patients treated with SA was gradually getting younger, with male patients predominating, mainly concentrated in the 11-14 age group. HyProCure 7 has the highest usage rate. In the children and adolescent group, 288 ft (37.31%) only underwent SA. In the adult group, 18 ft (7.63%) only underwent SA. Complications include sinus tarsi pain, peroneal spasms, achilles tendon tension, and muscle strength decline. The complication rate in the children and adolescent group was 5.05%, while in the adult group it was 28.81%. Overall, it was 10.62%. The removal rate of HyProCure in the children and adolescent group is 1.04%, in the adult group is 15.25%, and overall is 4.37%. The trend in flatfoot treated with SA was towards children and adolescent male patients, and sinus tarsi pain was the most common complication after SA. The complication rate and removal rate in the children and adolescent group were lower than those in the adult group. HyProCure can be removed without additional adverse effects.

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

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

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

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

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 August15, 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-termoutcomes 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.

Comparison of Radiological Parameters to Predict the Adult Acquired Flatfoot Deformity (AAFD) in Indian population: A Retrospective Study

Comparison of Radiological Parameters to Predict the Adult Acquired Flatfoot Deformity (AAFD) in Indian population: A Retrospective Study

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

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. 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 10mm 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. 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 lesshomogeneous 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%). 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 mechanismof arthritis. Nevertheless, it yields a better protection to the subtalar joint than Evans osteotomy. 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 III, case-control study.

Cotton Osteotomy: An Integral Midfoot Procedure for Forefoot Varus Correction

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

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

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

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

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

An Update Management of Pes Planus and Pes Cavus

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

Analysis of Patient-Reported Outcomes Following Triple Arthrodesis: A Minimum Two-Year Followup

Category: Hindfoot Introduction/Purpose: Adult acquired flatfoot deformity (AAFD) is a debilitating condition that is common in the United States. Triple arthrodesis (TA) is a treatment option reserved for advanced disease. Evidence on patient outcomes following this procedure remains limited. This study aims to report patient-reported outcomes following TA via patient reported outcome measurement information systems (PROMIS). Secondary aims are to delineate any demographics or patient characteristics that significantly impact PROMIS scoring. Methods: In this single institution study, we identified all patients who underwent triple arthrodesis between 2014 and 2021 based on CPT coding. Patients who underwent a TA procedure for AAFD with a minimum of 24 months follow-up were eligible for inclusion in this study. Patients under the age of 18, those undergoing revision surgeries, or those with pathologies other than AAFD were excluded from this study. Patient demographics and surgical complications were collected through chart review. The Patient Reported Outcomes Measurement Information System (PROMIS) survey and Foot Function Index (FFI) scores were collected via telephone interview. PROMIS scores were analyzed with a Type III “SS” ANOVA test to stratify independent risk factors and account for confounding variables. Results: 49 patients (43%) submitted responses to the survey. Patient outcomes were collected at an average of 5.50 years postoperatively. There were no significant differences in the rates of complications among any of the variables analyzed. The average PROMIS physical function score was 38.35, the average pain interference score was 61.52, and the average depression score was 49.82. Males and patients with prior foot and ankle procedures had significant increases in PROMIS physical function scores (p &lt;.05). The mean FFI scores were 58.56 for pain, 60.07 for disability, and 48.07 for activity limitation. Patients &gt; 50 years old had significantly higher FFI pain, disability, and total scores (p &lt;.05). VAS scores decreased preoperatively to postoperatively from 5.4 to 2.6. Conclusion: Our study is the first to examine variables significantly impacting PROMIS, FFI and VAS scores for patients undergoing TA for AAFD. Treatment of AAFD with TA appears to be beneficial in long-term reduction of pain. This study is one of the largest to date involving patient reported outcomes following TA and can serve as a prognostic tool for physicians to use when counseling patients prior to this procedure.

A Modified Technique for Lateral Column Lengthening as Part of Adult Acquired Flatfoot Deformity Correction: An Intact Medial Calcaneal Cortex, a Low-Profile Locking Plate With a Combination of Autologous Calcaneal Bone Graft and Demineralized Human Bone Matrix

Adult acquired flatfoot deformity encompasses deformities of the entire foot and ankle, with most clinical presentations comprising of a flexible planovalgus deformity and forefoot abduction. Numerous operative procedures have been proposed, and a lateral column–lengthening procedure is advocated to correct the forefoot abduction. Autologous iliac crest bone graft is routinely inserted into the opening-wedge osteotomy at the anterior calcaneum. Fixation methods are also variable with increasing use of locking plates to achieve stability at this osteotomy. Harvesting the iliac crest graft exposes the patient to significant donor site morbidity. We describe a modified lateral column–lengthening technique, leaving the medial calcaneum cortex intact, packing a combination of autologous calcaneal bone graft, and demineralized bone matrix into the osteotomy site, fixed with a low-profile locking plate. In the short term, our technique offers reduced rates of wound complications, symptomatic hardware, nonunion, and deformity recurrence when compared with published rates. Level of Evidence: Level IV, Case Series (retrospective).

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

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

Evaluation of the heel external rotation test in soft tissue deficiencies associated with adult acquired flatfoot deformity (AAFD). A cadaver sectioning analysis.

To date, evaluation of the heel external rotation test has not been taken with respect to AAFD. Traditional 'gold standard' tests do not account for the contribution of the midfoot ligaments towards instability. These tests would be flawed as any midfoot instability may produce a false positive result. To evaluate the differential contribution of the spring, deltoid and other local ligaments in external rotation generated at the heel. Serial ligament sectioning was performed on 16 cadaveric specimens, with a 40N-external rotation force applied to the heel. These were divided into four groups with different sequences of ligament sectioning. Measurements of the total amount/range of external, tibiotalar and subtalar rotation were made. The deep component of the deltoid ligament (DD) was the main ligament influencing heel external rotation (P<0.05, in all cases), and acted primarily at the tibiotalar joint (87.9 %). The spring ligament (SL) influenced heel external rotation predominantly (91.2 %) at the subtalar joint (STJ). Greater than 20 degrees external rotation could only be achieved with DD sectioning. The interosseous (IO) and cervical (CL) ligaments did not significantly contribute to external rotation at either joint (P>0.05). Clinically relevant external rotation (>20 degrees) is solely attributable to DD failure in the presence of intact lateral ligaments (LL). This test may improve detection of DD instability and allow clinicians to subclassify patients with Stage 2 AAFD into those where DD may or may not be compromised.

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

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

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

BackgroundPopulation-level data describing patient characteristics and interventions used in surgical treatment of adult acquired flatfoot deformity (AAFD) is lacking. MethodsWe 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. Results625 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. ConclusionsPatients with AAFD have low health-related quality of life before surgery. Treatment in Sweden follows best-available evidence but regional variations exist. Level of evidenceIII

Differential contribution of lateral plantar foot ligaments to lateral column stability – A cadaver based sectioning analysis

Lateral column (LC) instability occurs in adult acquired flatfoot deformity (AAFD). Differential ligament contribution to LC stability is unknown. The primary aim was to quantify this by using cadaver sectioning of lateral plantar ligaments. We also determined the relative contribution of each ligament to dorsal translation of the metatarsal head in the sagittal plane.17 below-knee cadaveric specimens, preserved by vascular embalming method, were dissected to expose plantar fascia, long/short plantar ligaments (L/SPL), calcaneocuboid (CC) capsule and inferior 4th/5th tarsometatarsal (TMT) capsule. Dorsal forces of 0 N, 20 N and 40 N were applied to the plantar 5th metatarsal head after sequential ligament sectioning in different orders. Pins provided linear axes on each bone, allowing relative angular bone displacements to be calculated. Photography and ImageJ processing software were then used for analysis.The LPL (and CC capsule) had the greatest contribution to metatarsal head motion (107 mm) after isolated sectioning. In the absence of other ligaments, sectioning these resulted in significantly increased hindfoot-forefoot angulation (p ≤ 0.0003). Isolated TMT capsule sectioning demonstrated significant angular displacement even when other ligaments remained intact (with intact L/SPL, p = 0.0005). CC joint instability required both LPL and capsular sectioning for significant angulation to occur, whilst TMT joint stability was largely dependent on its capsule.The relative contribution of static restraints to the lateral arch has not yet been quantified. This study provides useful information on relative ligament contribution to both CC and TMT joint stability, which may in turn improve understanding of surgical interventions used to restore arch stability.

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

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

Adult acquired flatfoot deformity: an update in classification

Adult acquired flatfoot deformity (AAFD) involves a complex spectrum of pathologies, arising primarily from failure of static restrains, leading to collapse of the medial longitudinal arch and further subsequent deformities in the foot. The landmark paper and classification by Johnson et al. proposed that pathology in the posterior tibial tendon (PTT) was key in the development of AAFD. Since then, the understanding of AAFD has evolved and advanced. Multiple structures aside from the PTT, such as the spring ligament, plantar fascia and deltoid ligament, have been identified to play a similarly key role in disease development and progression. Classification systems have also evolved to incorporate this new understanding. These include modifications to Johnson's classification (Myerson, Bluman) as well as new systems which aim to incorporate modern thinking, capture the wide spectrum of presentations or utilize modern advancements in imaging modalities. Current classification systems continue to aid understanding and management of AAFD, despite their increasing complexity. Future classifications should aim to provide a succinct way to describe and understand AAFD, as well as guiding prognosis and management.