Flatfoot Surgery for Flexible Progressive Collapsing Foot Deformity With Inflammatory Joint Diseases: A Report of 3 Cases.

CASE: Three cases of inflammatory joint diseases (systemic lupus erythematosus and ongoing juvenile idiopathic arthritis) with painful flexible progressive collapsing foot deformity (PCFD) underwent flatfoot surgery. All cases maintained sufficient radiological correction and achieved good clinical condition at final follow-up. CONCLUSION: Although the prospect for recurrence of the deformity is not clear, even in inflammatory joint diseases, flat foot surgery such as flexor digitorum longs transfer, spring ligament reconstruction, and lateral column lengthening could have a possibility to be indicated against PCFD, as long as disease activity could be well suppressed by drug therapy, subsequently subtalar and talonavicular joints could be preserved.

Minimally Invasive Method for Treatment of Syndromic Congenital Vertical Talus Deformity in Children.

BACKGROUND: Congenital Vertical Talus (CVT) is a rare form of rigid flatfoot commonly seen in patients with underlying neurologic syndromes. This study aims to evaluate the long-term effectiveness of the minimally invasive method for correcting CVT deformity in a large cohort of syndromic patients. METHODS: A single author recorded preoperative, 2-week postoperative, 1-year postoperative, and most recent radiographic measurements and complications for 25 patients treated with the minimally invasive method from 2006 to 2021. Patient-Reported Outcomes Measurement Information System (PROMIS) questionnaires were administered for 12 patients after January 1, 2015, when the institution began collecting PROMIS in all orthopaedic patients. Average follow-up was 55 months (13-111); 18 patients had minimum 24-month follow-up. RESULTS: Forty feet in 25 patients were analyzed. The average preoperative lateral talar axis-first metatarsal base angle (TAMBA) was 68.7 ± 21.3 vs 12.1 ± 8.9 after initial surgical intervention (P < .0001). There was a statistically significant increase in the lateral TAMBA between the initial postoperative and final follow-up visits (13.0 vs 21.6, P = .02). Radiographic recurrence of talonavicular deformity was noted in 12 feet (30.9%); 7 (15.55%) required corrective surgery. Larger preoperative lateral TAMBA was predictive of recurrence. Notably, patients with arthrogryposis experienced higher radiographic recurrence than other syndromic patients (45.0% vs 14.3%, P = .0384). PROMIS scores were within population norms. CONCLUSION: The study suggests that less than one-third of syndromic CVT patients experienced a radiographic recurrence of talonavicular deformity, with 15% requiring further surgical intervention at an average of 55 months following the initial procedure. A higher incidence of radiographic recurrence occurred in patients with distal arthrogryposis. These findings, along with the satisfactory patient-reported outcomes, suggest that the minimally invasive technique is an effective treatment method for syndromic CVT, underscoring the necessity for clinicians to provide detailed prognoses and consider more intensive follow-up for those at higher risk.

Effects of subtalar arthroereisis in children, assessed on the basis of quality-of-life questionnaires.

INTRODUCTION AND OBJECTIVE: Subtalar arthroereisis is a procedure commonly performed in children with flat feet. The procedure is performed when conservative treatment did not have the desired effect,or when the patient's abnormal symptoms are very severe and make it difficult for them to function normally in daily life. The aim of this study was to assess whether subtalar arthroereisis and physiotherapy improve the quality of life among children with flat feet. MATERIAL AND METHODS: The study comprised 79 patients (140 operated feet) diagnosed with a flat foot defect who underwent a subtalar arthroereisis procedure. A self-administered questionnaire and a shortened version of the standardised WHOQOL-BREF questionnaire were used in the research. RESULTS: The study confirmed that the patients' quality of life after surgery was high in all the areas regarding the somatic, psychological, social and environmental domains. In the group of children assessed 13-24 months after surgery. it was also found that rapid fatigue after exercise (30% ± 9%) and Achilles tendon contracture (7% ± 4%) were significantly reduced. The results of the study confirmed that subtalar arthroereisis contributes to a decreased demand for orthoses in children (9% ± 6%) and for orthopaedic footwear (11% ± 5%) than before surgery. CONCLUSIONS: The employment of subtalars arthroereisis has a positive effect on the quality of life of children with flat feet. The surgery contributes to a reduction in pain and other abnormal symptoms that are associated with flat feet. In addition, physiotherapy performed after the procedure had a positive effect on the healing process and contributed to the improvement of the children's quality of life.

Determining the changes in morphology and loading status following medial displacement calcaneal osteotomy for flatfoot using patient-specific finite element models.

Medial displacement calcaneal osteotomy (MDCO) is the standard procedure for flatfoot. We investigated the effect of MDCO on the foot using a finite element analysis. Foot models were created from computed tomography data of 8 patients with flat feet. MDCO was performed on each model with bone translation distance of 4, 8, and 12 mm. The morphological changes, plantar pressures, and stress percentage on the talocrural and subtalar joints were evaluated before and after surgery. Morphological evaluation showed improvement in the medial longitudinal arch. The stress percentage of plantar pressure in the medial area decreased, and the stress percentage of plantar pressure in the mid- and lateral forefoot area increased. At the talocrural joint, the medial and middle stress percentage increased, while the lateral and posterior stress percentage decreased. In the subtalar joint, the stress percentage in the middle subtalar joint increased and that in the posterior subtalar joint decreased. Within the posterior subtalar joint, the anterior and medial stress percentage increased, while the posterior and lateral stress percentage decreased. Preoperative simulation using the finite element analysis may be useful in understanding postoperative morphological changes and loading conditions to perform patient-specific surgery.

Outcomes of the "Calcaneo-stop" procedure for treating symptomatic flexible flatfoot in children: A systematic review and meta-analysis of 2394 feet.

BACKGROUND: This study evaluates the efficacy of the calcaneo-stop (C-Stop) procedure's effectiveness in treating symptomatic flexible flatfoot (FFF) in children. METHODS: A systematic review and meta-analysis were conducted using PubMed, Embase, and Cochrane databases to identify studies until 2023 on the outcomes of the C-Stop procedure in children with FFF. The risk of bias was assessed using MINORS criteria. RESULTS: Of 85 studies screened, 20 involving 2394 feet from 1415 patients (mean age 11.2 ± 1.3 years) were included. Post-procedure, significant improvements were noted in pain reduction (93.5%), heel alignment (95.21%), and radiological measures, including reductions in Kite (7.32º), Meary (11.65º), Costa-Bartani angles (17.11º), talar declination (12.63º) and increase in Calcaneal Pitch Angle (5.92º). AOFAS scores increased by 22.32 points on average, with 94.83% reporting high satisfaction. Complication rate was low (7.8%). CONCLUSIONS: The C-Stop procedure is effective for treating FFF in children, offering significant clinical, radiological, and functional improvements with high patient satisfaction and a low complication rate. LEVEL OF EVIDENCE: Level IV, Systematic review of Level-IV studies.

Talocalcaneal coalition classifications: A critical analysis review and suggested new classification system with implications for treatment.

Talocalcaneal coalitions (TCC) is the second most frequent tarsal coalition reported. Our aim was to review talocalcaneal coalition classifications and to propose a new classification emphasizing a therapeutic approach. None of the classifications described for TCC mention the presence of flatfoot or valgus hindfoot, which are the key elements when defining the optimal treatment of this disease. We defined five clinical and radiological factors that would guide the choice of surgical treatment and based on these, we proposed a new classification system.

Simultaneous subtalar arthroeresis, midfoot soft tissue release, and talo-navicular arthrodesis in children with planovalgus neurologic foot.

PURPOSE: Planovalgus foot deformity (PVFD) is common in children with neuromuscular conditions and severe deformity may require surgical correction. This study aims to assess clinical and radiological outcomes of PVFD secondary to neuromuscular disease managed by subtalar arthroeresis (SuAE), midfoot soft tissue release and talo-navicular arthrodesis (TNA). METHODS: A retrospective analysis of children with neuromuscular disease and nonreducible PVFD who underwent SuAE, midfoot soft tissue release, and TNA and with a minimum follow-up of 5 years was performed. A total of 60 patients with neuromuscular disease (108 feet) including cerebral palsy were reviewed. Mean age at surgery was 12.7 ± 4.6 years (6-17). Mean follow-up was 7 ± 2.9 years (5-10). Clinical outcomes and radiologic correction at final follow-up were compared with preoperative values. Statistical analysis was performed and significance was set at P < 0.01. RESULTS: Statistically significant radiological improvements between pre- and postoperative values were found for all angle values. At final follow-up, there was a significant improvement in VAS score (4.8 vs. 2; P < 0.01). There was also a positive trend in the improvement of walking ability. No cases of pseudoarthrosis were reported at final follow-up. Screw removal was required in 5 out of 108 feet (4.6%) and 2 feet (3.3%) had delayed medial wound healing. CONCLUSIONS: SuAE combined with TNA and midfoot soft tissue is a safe and feasible procedure that can provide good clinical and radiologic results in patients with neuromuscular disease and nonreducible PVFD; the procedure can improve foot stability, and has a limited number of complications. LEVEL OF EVIDENCE: IV.

[Flatfoot in children]. / Kindlicher Knick-Senk-Fuß.

The diagnosis of flatfoot in children is made clinically. In most cases it is an age-appropriate benign physiological variant, as long as it can be passively and actively redressed and the child does not show any neurological abnormalities, especially under the age of 6 years. Treatment is only indicated for symptomatic variants. In the case of rigid flatfeet, further diagnostics are necessary to exclude neurological or structural causes. Subtalar arthroereisis has become established and is an effective but slightly invasive procedure. Further options include the lengthening and medial translational osteotomy of the calcaneus or the Cotton operation; however, the indications must always be critically questioned, especially for surgical but also for conservative treatment, even if it is the wish of the family.

Preliminary Results of Calcaneal Lengthening Osteotomy Combined With Extra-articular Subtalar Arthrodesis for Severe Pes Planovalgus Deformity in Children With Cerebral Palsy: A New Surgical Technique.

OBJECTIVE: Pes planovalgus is the most common foot deformity seen in patients with cerebral palsy (CP). There are several different treatment modalities to treat this condition. Single or double calcaneal osteotomies, extra-articular arthrodesis, calcaneo-cuboido-cuneiform osteotomy, intraarticular arthrodesis, and arthroereisis are some of these modalities. Currently, there is insufficient information to determine the most effective treatment approach for pes planovalgus in children with CP. The aim of this study is to show the short to mid-term results of the new technique which combines calcaneus lengthening osteotomy, extra-articular subtalar arthrodesis, and soft tissue reconstruction that aims to decrease recurrence and complication rates of pes planovalgus surgery for patients with ambulatory CP. METHODS: Patients with CP who were treated with calcaneal lengthening surgery and extra-articular subtalar arthrodesis between 2018 and 2021 were investigated retrospectively. All patients were ambulatory and Gross Motor Function Classification System I-II-III. Functional levels of the patients were assessed with the American Orthopaedic Foot and Ankle Society, Ankle-Hindfoot Score, and the Foot and Ankle Ability Score (Foot and Ankle Ability Measure) in preoperative and postoperative periods. On anteroposterior x-rays, talus-first metatarsal, talocalcaneal, talonavicular coverage angle and on lateral x-rays talus-first metatarsal, talocalcaneal, calcaneal inclination angle and talar tilt angle were evaluated. RESULTS: The mean follow-up was 46 (range: 36 to 60) months. The mean American Orthopaedic Foot and Ankle Society increased from 41 (20 to 79) to 74 (38 to 93; P < 0.001). The mean Foot and Ankle Ability Measure increased significantly from 35 (7 to 73) to 54 (29 to 96; P <0.001). Clinical results were "satisfactory" for 32 feet, while they were "unsatisfactory" for 2 feet. Significant deformity correction was observed in all radiologic parameters. CONCLUSION: Our technique is found to be efficient for patients with Gross Motor Function Classification System I-II-III CP with pes planovalgus deformity. In short to mid-term follow-up, the technique achieved successful clinical and radiologic results with low complication rates. Superiority of this technique compared with the traditional ones can only be shown with randomized prospective studies. LEVEL OF EVIDENCE: Level III-retrospective cohort study.

Medial column fusion for degenerative pesplanovalgus deformity. Report of 9 patients.

Degenerative pesplanovalgus is a progressive disabling condition; there are more than one surgical procedure used in the treatment with varied outcomes. The aim of the current study is to highlight the benefits of the medial column fusion surgery in the treatment of this condition. Nine adult patients with rigid degenerative pesplanovalgus (without significant valgus heel deformity) underwent medial column fusion between January 2015 to December 2020. The procedure was combined with subtalar fusion in four patients and lateral column lengthening in one patient. The mean follow-up period was 19.5 months (range, 15-27). Regular clinical and radiological reviews was carried out in the postoperative period. The mean Manchester Oxford foot score was good in 7 patients, and fair in two patients. The mean Meary angle was 5.8 ± 5.4° preoperatively and improved to 0.9 ± 7.7° at final follow-up, and the mean Pitch angle also improved from 12.5 ± 3.7° preoperatively to 23.2 ± 4.1° (P < .001). In a patient, and at a different stage, talo-navicular fusion was added to the medial column fusion.The outcome of this series of cases was encouraging and medial column fusion continues to be a good option in the management of rigid pesplanovalgus deformity.

Conventional vs Augmented Reality-Guided Lateral Calcaneal Lengthening Simulated in a Foot Bone Model.

BACKGROUND: Acquired adult flatfoot deformity (AAFD) results in a loss of the medial longitudinal arch of the foot and dysfunction of the posteromedial soft tissues. Hintermann osteotomy (H-O) is often used to treat stage II AAFD. The procedure is challenging because of variations in the subtalar facets and limited intraoperative visibility. We aimed to assess the impact of augmented reality (AR) guidance on surgical accuracy and the facet violation rate. METHODS: Sixty AR-guided and 60 conventional osteotomies were performed on foot bone models. For AR osteotomies, the ideal osteotomy plane was uploaded to a Microsoft HoloLens 1 headset and carried out in strict accordance with the superimposed holographic plane. The conventional osteotomies were performed relying solely on the anatomy of the calcaneal lateral column. The rate and severity of facet joint violation was measured, as well as accuracy of entry and exit points. The results were compared across AR-guided and conventional osteotomies, and between experienced and inexperienced surgeons. RESULTS: Experienced surgeons showed significantly greater accuracy for the osteotomy entry point using AR, with the mean deviation of 1.6 ± 0.9 mm (95% CI 1.26, 1.93) compared to 2.3 ± 1.3 mm (95% CI 1.87, 2.79) in the conventional method (P = .035). The inexperienced had improved accuracy, although not statistically significant (P = .064), with the mean deviation of 2.0 ± 1.5 mm (95% CI 1.47, 2.55) using AR compared with 2.7 ± 1.6 mm (95% CI 2.18, 3.32) in the conventional method. AR helped the experienced surgeons avoid full violation of the posterior facet (P = .011). Inexperienced surgeons had a higher rate of middle and posterior facet injury with both methods (P = .005 and .021). CONCLUSION: Application of AR guidance during H-O was associated with improved accuracy for experienced surgeons, demonstrated by a better accuracy of the osteotomy entry point. More crucially, AR guidance prevented full violation of the posterior facet in the experienced group. Further research is needed to address limitations and test this technology on cadaver feet. Ultimately, the use of AR in surgery has the potential to improve patient and surgeon safety while minimizing radiation exposure. CLINICAL RELEVANCE: Subtalar facet injury during lateral column lengthening osteotomy represents a real problem in clinical orthopaedic practice. Because of limited intraoperative visibility and variable anatomy, it is hard to resolve this issue with conventional means. This study suggests the potential of augmented reality to improve the osteotomy accuracy.

A modified lateral column lengthening for the treatment of flexible flatfoot: From clinical applications to finite element analysis.

BACKGROUND: Finite element (FE) analysis and clinical follow-up were used to evaluate the efficacy of a modified lateral column lengthening (H-LCL) for treating flexible flatfoot. METHODS: By applying inclusion and exclusion criteria, we selected patients who underwent H-LCL surgery at our institution from January 2019 to January 2023. We compared the Visual Analog Scale (VAS) scores, American Orthopaedic Foot and Ankle Society (AOFAS) scores, Pain Interference (PI), and Physical Function (PF) scores in Patient-Reported Outcomes Measurement Information System (PROMIS) between preoperative and final follow-up assessments of patients, as well as FE submodels. Furthermore, evaluate the H-LCL's biomechanical characteristics and clinical outcome before and after surgery. RESULTS: A total of 66 patients met the criteria. The average surgery time was 69.47 ± 13.22 min, and the follow-up duration was 15.18 ± 6.40 months. In the last follow-up, VAS and PI decreased compared to before surgery, while AOFAS and PF increased compared to before surgery. Meary's angle (dorsoplantar image and lateral image), calcaneal valgus angle, and talonavicular coverage angle decreased compared to before surgery, while the pitch angle increased compared to before surgery. In FE analysis, postoperative tension on the plantar fascia (PF), spring ligament (SL), and posterior tibial tendon (PTT) decreased compared to before surgery, pressure on the talonavicular joint and subtalar joints also decreased compared to before surgery, and there was no significant change in pressure on the calcaneocuboid joint. CONCLUSION: H-LCL in correcting flexible flatfoot resulted in a significant improvement of clinical outcome scores and led to good radiological correction of flatfoot deformities. It can reduce the soft tissue and interosseous pressure in maintaining the foot arch.

Isolated Subtalar Repositional Arthrodesis Compared With Triple Arthrodesis for the Treatment of Progressive Collapsing Foot Deformity.

The optimal extent of arthrodesis for severe and rigid progressive collapsing foot deformity is controversial. Traditionally, triple arthrodesis has been recommended; however, good results have been reported using subtalar arthrodesis only. We compared the results of triple arthrodesis and isolated subtalar repositional arthrodesis. A total of 22 symptomatic feet were evaluated retrospectively. Isolated subtalar repositional arthrodesis was performed in 13 cases (the subtalar group) and double or triple arthrodesis in 9 cases (the triple group). Various radiographic variables for assessing flatfoot and osteoarthritic changes in ankle and tarsal joints were measured and compared between the 2 groups at 3 time points: preoperatively, 3 months postoperatively, and 4 y postoperatively. Additionally, we analyzed various factors that affect postoperative valgus talar tilt in the ankle joint, which has been associated with poor prognosis. There were no differences in preoperative demographic data and the severity of the disease between the 2 groups; both groups showed improvement in radiographic parameters postoperatively compared with preoperative results. With the numbers available, no significant differences could be detected in postoperative radiographic measurements between the 2 groups. Of all the variables analyzed, postoperative hindfoot alignment angle was associated with postoperative talar tilt development. Additionally, postoperative talar tilt was observed more in triple group than in subtalar group. In conclusion, isolated subtalar repositional arthrodesis is an effective procedure to correct advanced progressive collapsing foot deformity. In addition, Chorpart joint arthrodesis with improper position can cause valgus talar tilt in the ankle joint.

Impact of the medial displacement calcaneal osteotomy on foot biomechanics: a systematic literature review.

INTRODUCTION: Progressive collapsing foot deformity (PCFD), formally known as "adult-acquired flatfoot deformity" (AAFFD), is a complex foot deformity consisting of multiple components. If surgery is required, joint-preserving procedures, such as a medial displacement calcaneal osteotomy (MDCO), are frequently performed. The aim of this systematic review is to provide a summary of the evidence on the impact of MDCO on foot biomechanics. MATERIALS AND METHODS: A systematic literature search across two major sources (PubMed and Scopus) without time limitation was performed according to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) criteria. Only original research studies reporting on biomechanical changes following a MDCO were included. Exclusion criteria consisted of review articles, case studies, and studies not written in English. 27 studies were included and the methodologic quality graded according to the QUACS scale and the modified Coleman score. RESULTS: The 27 included studies consisted of 18 cadaveric, 7 studies based on biomechanical models, and 2 clinical studies. The impact of MDCO on the following five major parameters were assessed: plantar fascia (n = 6), medial longitudinal arch (n = 9), hind- and midfoot joint pressures (n = 10), Achilles tendon (n = 5), and gait pattern parameters (n = 3). The quality of the studies was moderate to good with a pooled mean QUACS score of 65% (range 46-92%) for in-vitro and a pooled mean Coleman score of 58 (range 56-65) points for clinical studies. CONCLUSION: A thorough knowledge of how MDCO impacts foot function is key in properly understanding the postoperative effects of this commonly performed procedure. According to the evidence, MDCO impacts the function of the plantar fascia and Achilles tendon, the integrity of the medial longitudinal arch, hind- and midfoot joint pressures, and consequently specific gait pattern parameters.

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.

In silico comparative biomechanical analysis of oblique and chevron medial displacement calcaneal osteotomies for pes planus deformity.

BACKGROUND: Medializing displacement calcaneal osteotomy is commonly performed as part of reconstructive surgery for patients with valgus hindfoot and progressive pes planus deformity. Among several types of calcaneal osteotomies, the oblique and Chevron osteotomy patterns have been commonly described in the literature and gained popularity as they are easily reproducible through percutaneous techniques. Currently, there is scarce evidence in the literature on which cut pattern is superior in terms of stability. To investigate the impact of cut pattern and posterior fragment medialization level on foot biomechanics, computational methods are employed. METHODS: Ankle weightbearing computer tomography (CT) scans of seven patients diagnosed with stage II pes planus deformity are segmented and converted into 3D computational models. Oblique and Chevron osteotomy patterns are modeled independently for each patient. The posterior fragments are medially translated by 8-, 10- and 12-mm and subsequently fixated to the anterior calcaneus with two screws. A total of 42 models are exported to finite element software for biomechanical simulations. Among the investigated parameters, the higher stiffness and lower von Mises stress at the osteotomy interface and the screw site are assumed to be precursors of better stability. RESULTS: It is recorded that as the medialization level increases, the stiffness decreases, and overall stresses increase. Also, it is observed that the Chevron cut produces a stiffer construct while the overall stresses are lower, indicating better stability when compared to the oblique cut. The statistical comparisons of the relevant groups that support these trends are found to be significant (p < 0.05). CONCLUSION: Chevron osteotomy showed superior stability compared to the oblique osteotomy while underscoring the negative impact of increased medialization of the posterior fragment. CLINICAL RELEVANCE: Opting for a lower medialization level and implementing the Chevron technique may facilitate union and earlier weightbearing.

Biomechanical Effects of Subtalar Joint Fusion and Medial Ligament Reconstruction in Simulated Progressive Collapsing Foot Deformity.

BACKGROUND: The purpose of this study is to investigate the biomechanical effect of medial displacement calcaneal osteotomy (MDCO), subtalar joint fusion (SF), and medial ligament reconstruction (MLR: deltoid-spring ligament) in a severe flatfoot model. We hypothesized that (1) combination of MDCO and SF improves the tibiotalar and foot alignment in severe progressive collapsing foot deformity (PCFD) cadaver model. (2) However, if a residual valgus heel alignment remains after MCDO and SF, it can lead to increased medial ligament strain, foot malalignment, and tibiotalar valgus tilt, which will be mitigated by the addition of MLR. METHODS: Ten fresh-frozen cadaveric foot specimens were used to create a severe flatfoot model. The foot alignment changes, including the talo-first metatarsal angle in the axial and sagittal planes, subtalar angle, and tibiotalar angle in the coronal plane, were measured. The angles were measured at the initial condition, after creating the severe flatfoot model, and after each successive reconstructive procedure in the following order: (1) MDCO, (2) SF, and (3) MLR. RESULTS: Tibiotalar valgus tilt was decreased with the MDCO procedure: 4.4 vs 1.0 degrees (P = .04). Adding in situ SF to the MDCO led to increased tibiotalar tilt to 2.5 degrees was different from the initial condition (P = .01). Although the tibiotalar valgus tilt was significantly decreased after adding the MLR to the MDCO/SF procedure compared with the severe flatfoot model (0.8 vs 4.4 degrees, P = .03), no significant difference in the tibiotalar valgus tilt was observed between MDCO/SF and MDCO/SF with MLR. CONCLUSION: Our results demonstrated that MDCO significantly improved forefoot abduction and medial arch alignment, with no significant additional improvement observed with addition of SF. Following SF, a residual valgus heel alignment can contribute to subsequent tibiotalar valgus tilt. The addition of MLR did not show significantly decreased tibiotalar valgus tilt following SF. CLINICAL RELEVANCE: Residual valgus heel alignment after subtalar joint fusion in the surgical treatment of PCFD can lead to increased medial ligament strain. Although MLR might be considered for providing medial stability, it may not necessarily prevent the development of tibiotalar valgus tilt.

Does the Presence of Asymptomatic Flatfoot Deformity Impact the Clinical and Radiographic Outcomes of the Minimally Invasive Chevron and Akin Bunionectomy?

BACKGROUND: Flatfoot deformity is believed to play a role in hallux valgus development and recurrence. While symptomatic flatfoot deformity can be treated with separate procedures at the time of hallux valgus correction, the question remains whether the patient undergoing correction of a symptomatic hallux valgus deformity should have their asymptomatic flatfoot concurrently addressed. We aimed to investigate whether the presence of asymptomatic flatfoot influences patient-reported and radiographic outcomes of the minimally invasive chevron and Akin bunionectomy. METHODS: A total of 104 patients were included in this study. Forty-two asymptomatic patients met the radiographic criteria for flatfoot while 62 had a normal arch. Patient-reported outcomes were evaluated and compared between the two groups using validated PROMIS measures preoperatively and at a minimum one-year postoperatively. Radiographic outcomes including hallux valgus angle (HVA), intermetatarsal angle (IMA), Meary's angle, calcaneal pitch (CP), and talonavicular coverage angle (TNCA) were measured and compared preoperatively and minimum six-months postoperatively. RESULTS: Both groups demonstrated similar preoperative and postoperative PROMIS scores with significant improvements in physical function, pain interference, pain intensity, and global physical health. Preoperatively, HVA was similar between both groups, however the flatfoot group showed a greater IMA, Meary's angle, TNCA, and lower CP. Postoperatively, HVA and IMA were similar between groups, although patients in the flatfoot group retained a significantly greater Meary's angle, TNCA, and lower CP. Both groups showed significant improvements in HVA, IMA, and TNCA. CONCLUSION: Our study indicates that the minimally invasive chevron and Akin bunionectomy leads to improved clinical and radiographic hallux valgus outcomes without adversely impacting radiographic flatfoot parameters. Therefore, the MIS bunionectomy may be an effective option for hallux valgus correction in patients with mild, asymptomatic flatfoot. LEVEL OF EVIDENCE: Level III, retrospective cohort.

Minimally invasive surgery in medial displacement calcaneal osteotomy for acquired flatfoot deformity: a systematic review of the literature.

BACKGROUND: Minimally invasive surgery (MIS) in medial displacement calcaneus osteotomy (MDCO) has been proposed for surgical correction of adult-acquired flat foot deformity (AAFD) to reduce complications of open approaches. The aim of our study is to systematically analyze complications and the clinical and radiological results of MIS- MDCO. METHODS: A systematic review of the English literature was performed on 30th October 2023. Randomized controlled trials and non-randomized trials, cohort studies, case-control studies and case series concerning surgical correction of AAFD with MIS-MDCO and with at least 15 patients were included. Case reports, technical notes, animal or cadaveric studies were excluded. The quality and risk of bias of the studies included were evaluated using GRADE and MINORS systems. Complications rate, clinical and radiological results were inferred from the studies included. RESULTS: Nine articles were included. A total of 501 cases treated with MIS-MDCO were analysed with a mean follow-up of 11.9 ± 5.1 months. The reported wound infection rate was about 3% and sural neuropathy was rated about 1%. Only 4% of the cases required removal of the screw for pain. In the comparative studies (MIS versus Open MDCO), comparable clinical results but with significant differences (P < 0.001) in infection rates (1% versus 14%) and sural neuropathy (2% versus 1%) were observed. CONCLUSION: AAFD correction performed with MIS-MDCO, with the limitation of a poor quality and high risk of bias of the included studies, seems to provide good clinical results and high subjective satisfaction with a lower complication rate compared to open approach. Further high-quality long-term comparative studies could better clarify complications and clinical and radiological outcomes of the MIS technique in the treatment of AAFD. LEVEL OF EVIDENCE: Level IV.

Medializing Calcaneal Osteotomy for progressive collapsing foot deformity alters the three-dimensional subtalar joint alignment.

BACKGROUND: A medializing calcaneal osteotomy (MCO) is considered as one of the key inframalleolar osteotomies to correct progressive collapsing foot deformity (PCFD). While many studies were able to determine the post-operative hind- and midfoot alignment, alternations of the subtalar joint alignment remained obscured by superposition on plain radiography. Therefore, we aimed to assess the hind-, midfoot- and subtalar joint alignment pre- compared to post-operatively using 3D weightbearing CT (WBCT) imaging. METHODS: Seventeen patients with a mean age of 42 ± 17 years were retrospectively analyzed. Inclusion criteria consisted of PCFD deformity corrected by a medializing calcaneal osteotomy (MCO) as main procedure and imaged by WBCT before and after surgery. Exclusion criteria were patients who had concomitant calcaneal lengthening osteotomies, mid-/hindfoot fusions, hindfoot coalitions, and supramalleolar procedures. Image data were used to generate 3D models and compute the hindfoot (HA), midfoot (MA) - and subtalar joint (STJ) alignment in the coronal, sagittal and axial plane, as well as distance maps. RESULTS: Pre-operative measurements of the HA and MA improved significantly relative to their post-operative equivalents p < 0.05). The post-operative STJ alignment showed significant inversion (2.8° ± 1.7), abduction (1.5° ± 1.8), and dorsiflexion (2.3° ± 1.7) of the talus relative to the calcaneus (p < 0.05) compared to the pre-operative alignment. The displacement between the talus and calcaneus relative to the sinus tarsi increased significantly (0.6 mm±0.5; p < 0.05). CONCLUSION: This study detected significant changes in the sagittal, coronal, and axial plane alignment of the subtalar joint, which corresponded to a decompression of the sinus tarsi. These findings contribute to our clinical practice by demonstrating the magnitude of alteration in the subtalar joint alignment that can be expected after PCFD correction with MCO as main procedure.