Subtalar Arthroereisis Implant Removal in Adults: A Prospective Study of 100 Patients

Clinical outcomes of subtalar arthroereisis for the treatment of stage 1 flexible progressive collapsing foot deformity

BACKGROUND

The use of subtalar arthroereisis as an adjunct to the surgical treatment of stage 1 flexible progressive collapsing foot deformity (PCFD) is controversial. The aim was to investigate the clinical outcomes and report the implant removal rate of subtalar arthroereisis as an adjunct for stage 1 PCFD.

METHODS

A retrospective study of 212 consecutive feet undergoing operative management of stage 1 PCFD with adjunctive subtalar arthroereisis between October 2010 and April 2018. The primary outcome was the Foot and Ankle Outcome Score (FAOS). Secondary outcomes included Foot and Ankle Disability Index (FADI), Euroqol-5D-5L Index and implant removal rate.

RESULTS

Post-operative clinical FAOS outcomes were collected for 153 feet (72.2%). At mean 2.5-year follow-up, the mean ± standard deviation FAOS for each domain was as follows; Pain: 81.5 ± 18.5, Symptoms: 79.5 ± 12.9, Activities of Daily Living: 82.5 ± 15.4 and Quality of Life: 64.2 ± 23.7. EQ-5D-5L Index was 0.884 ± 0.152. Pre-operative scores were available for 20 of these feet demonstrating a statistically significant improvement in all FAOS, FADI and EQ-5D-5L domains (p < 0.05). The implant removal rate for persistent sinus tarsi pain was 48.1% (n = 102).

CONCLUSION

Use of a subtalar arthroereisis implant as an adjunct to conventional procedures in stage 1 flexible PCFD can result in significant improvement in pain and function. Patients should be counselled as to the relatively frequent rate of subsequent implant removal.

LEVEL OF EVIDENCE

IV.

Design of 3D printing osteotomy block for foot based on triply periodic minimal surface

The ankle joint, which connects the lower limbs and the sole of the foot, is prone to sprain during walking and sports, which leads to ankle arthritis. Supratroleolar osteotomy is an ankle preserving operation for the treatment of ankle arthritis, in which the osteotomy is an important fixing and supporting part. In order to avoid stress shielding effect as much as possible, the osteotomy block is designed as a porous structure. In this study, the osteotomy block was designed based on three-period minimal surface, and the designed structure was manufactured by 3D printing. The mechanical properties of different structures were studied by mechanical test and finite element simulation. In mechanical tests, the Gyroid structure showed a progressive failure mechanism from bottom to bottom, while the Diamond structure showed a shear failure zone at 45° Angle, which was not conducive to energy absorption and was more prone to brittle fracture than the Gyroid structure. Therefore, the Gyroid structure is valuable for further research in the development of porous osteotomy.

Comparative study between medial displacement calcaneal osteotomy using modified step plate and arthroereisis for management of planovalgus feet

Background: Flexible flatfoot is a common condition that is characterized by hindfoot valgus with longitudinal medial-arch collapse. Many strategies for treatment have been reported but according to the current literature, controversy remains. Objectives: To compare the clinical and radiological outcomes of medializing calcaneal osteotomy utilizing modified step plate and subtalar arthroereisis utilizing conical subtalar implant for patients with symptomatic flexible pes planus. Methods: A prospective, randomized, double center study was conducted between May 2017 and May 2019 at the Foot and Ankle Department of Cairo University Hospital and El Sahel Teaching Hospital on 26 patients (37 feet) with flexible flat feet to compare between medial displacement calcaneal osteotomy using modified locked step plate (group A) compromising 17 feet and arthroereisis using subtalar implant (group B) compromising 20 feet. Results: By the end period of the study, 25 males and 12 females were available for our analysis of results with a mean follow-up period of 10.14 months (range 7–14 months), clinical scoring (American Orthopaedic Foot and Ankle Society score, Foot Functional Index) with radiological analysis revealed a non-significant difference between both groups, the overall complication rate was 16.2%. Conclusion: Both medial displacement calcaneal osteotomy and subtalar arthroereisis significantly improved radiographic and subjective clinical outcome measures in the surgical treatment of painful flexible planovalgus feet. The less-invasive nature and lower potential morbidity suggest that judicious use of arthroereisis implants is an appropriate alternative.

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.

Patient Outcomes Following Extra-Osseous Talo-Tarsal Stabilization for Foot Hyperpronation

The aim is to present a single-center case series of patients with symptomatic hyperpronated feet treated with arthroereisis by using a second generation extra-osseous talo-tarsal stabilization device. This case series enrolled 123 feet in 87 patients (20 [6-75] years) treated with arthroereisis, either isolated (76 cases) or combined procedure (47 cases). At their final follow-up, a patient reported questionnaire (overall satisfaction, foot stability and shape, activities of daily living, pain level, and analgesics usage) was distributed. The average postoperative follow-up period was 30 (13-55) months. Nineteen (15%) cases required at least one revision surgery: the implant was manipulated in 5 (4%), while 14 cases (11%) required definitive implant removal. The predominant reason for implant removal was pain (50%), followed by implant migration (27%). The pediatric population with isolated procedure showed lowest revision rate (5%), while adults with combined ankle/hindfoot procedures demonstrated revision rate of 50%. The overall patient satisfaction after arthroereisis was 84%. The patients' perceived improvement in foot stability was 75%, foot shape 85%, and activities of daily living 64%. Eighty-two percent of cases reported no analgesics usage in the last month and mean visual analogue scale (0-10) pain level decreased from 5.5 to 2.2 (p < .001). The subgroup analyses of patient-reported questionnaires revealed the best outcome in the pediatric-isolated cases, while adults with combined procedures reported the lowermost outcome. Extra-osseous talo-tarsal stabilization demonstrated a low rate of revisions surgery and a high satisfaction rate as an isolated procedure. Patients with conjoined procedures experienced more revisions and considerably lower satisfaction rates.

HyProCure for Pediatric Flexible Flatfoot: What Affects the Outcome

BACKGROUND

The high success rate, minimal invasion, and safety of subtalar arthroereisis (SA) have made it a primary mode of surgical management for pediatric flexible flatfoot. The HyProCure procedure is a new surgery for SA, However, very few available studies reported the therapeutic effects of the HyProCure procedure, especially in pediatric flexible flatfoot. The main aim of the present study was to investigate the clinical and radiological outcomes of the HyProCure procedure for pediatric flexible flatfoot and analyze the risk factors for therapeutic outcomes and sinus tarsi pain.

METHODS

In this retrospective cohort study, 69 pediatric flexible flatfoot patients (107 feet) who underwent the HyProCure procedure were included between July 2015 and September 2020. All patients underwent the HyProCure procedure with or without gastrocnemius recession. The Maryland foot score (MFS), visual analog scale (VAS), radiographic data, and complications were assessed at a minimum 1-year follow-up and statistically analyzed.

RESULTS

The mean follow-up was 35.9 months (range, 13-73 months). At the last follow-up, VAS (0.64 ± 1.16) was significantly lower than the preoperative VAS (4.06 ± 1.43) (p < 0.001); MFS (90.39 ± 12.10) was significantly higher than the preoperative MFS (71.36 ± 10.25) (p < 0.001). The AP talar-second metatarsal angle (T2MT angle) significantly decreased from 17.0 ± 5.4° preoperatively to 11.4 ± 5.2° at the last follow-up (p < 0.001). The lateral talar-first metatarsal angle (Meary's angle) significantly decreased from 13.8 ± 6.4° preoperatively to 6.3 ± 5.0° at the last follow-up (p < 0.001). The calcaneal declination angle (Pitch angle) significantly increased from 13.5 ± 4.9° preoperatively to 14.8 ± 4.4° at the last follow-up (p < 0.001). Logistic regression analysis indicated that patients with a longer distance from the tail end of the implant exceeding the longitudinal talar bisection line had 275.8% greater odds of MFS < 90. Yet, no risk factors were found in connection with sinus tarsi pain.

CONCLUSIONS

The HyProCure procedure for pediatric flexible flatfoot achieved satisfactory curative effects with a low complication rate; implant depth was associated with unsatisfactory postoperative outcome.

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.

Is subtalar arthroereisis a good procedure in adult-acquired flatfoot? A systematic review of the literature

INTRODUCTION

The aim of the present systematic literature review was to determine results and complications in subtalar arthroereisis for stage-2 adult-acquired flatfoot.

METHOD

A search of the PubMed, Medline, CINAHL, Cochrane and Embase databases used MeSH terms "arthroereisis" AND "flatfoot" OR "adult-acquired flatfoot" OR "pes planovalgus" OR "pes planus". Two of the authors analyzed 125 articles. After reading titles and Abstracts, 105 articles were read in full text and their references were analyzed. Finally, 12 articles were selected and divided into 2 groups: isolated and associated arthroereisis.

RESULTS

Improvement in functional scores was greater in associated arthroereisis. Whether isolated or associated, arthroereisis achieved radiologic correction. However, the rate of complications was high, mainly concerning tarsal sinus pain.

CONCLUSION

Subtalar arthroereisis for stage-2 adult-acquired flatfoot is rarely performed in isolation. When it is associated to other procedures, good radiologic and clinical results can be expected.

LEVEL OF EVIDENCE

IV.

Flexible Progressive Collapsing Foot Deformity: Is There Any Role for Arthroereisis in the Adult Patient?

Over the last two decades there is a growing interest in the adult literature for subtalar joint arthroereisis. Parallel to this interest, there have been improvements in the design and biomechanics of the implant, although the main indication of subtalar joint arthroereisis in adults is not clear. Most studies show significant improvement in postoperative clinical scores and visual analog scores. Sinus tarsi pain, being the most common complication, is the main determinant of clinical satisfaction. This review focuses on the role and complications of subtalar joint arthroereisis in the adult population.

Lateral column osteotomy versus subtalar arthroereisis in the correction of Grade IIB adult acquired flatfoot deformity: A clinical and radiological follow-up at 24 months

BACKGROUND

Adult acquired flat foot deformity (AAFD) is a spectrum of conditions which can be progressive if untreated. Surgical correction and restoration of anatomical relationship are often required in the treatment of symptomatic Grade II AAFD after a failed course of conservative treatment. There is a paucity of literature recommending best practice-especially in the adult population. The authors aim to compare radiological and clinical outcomes of two widely employed surgical techniques in the treatment of symptomatic AAFD.

METHODS

A retrospective study of 76 patients with Grade IIB AAFD and had undergone either lateral column lengthening (LCL) or subtalar arthroereisis (STA) surgical correction of their symptomatic AAFD. Each technique was augmented with both bony osteotomy and soft tissue transfer as determined by on table assessment. Clinical and radiological outcomes were reviewed 24 months after surgery.

RESULTS

LCL and STA groups had comparable radiological outcomes at 24 months after surgery. However, LCL group demonstrated superior American Orthopaedic Foot and Ankle Society (AOFAS) midfoot (90.3 ± 12.6 vs 81.1 ± 20.6, p < 0.001) as well as Visual Analogue Scale (VAS) midfoot scores (0.5 ± 1.6 vs 1.3 ± 2.4, p < 0.001) at 24 months compared to the STA group. STA had a higher complication rate (20.6% vs 4.4%), with all cases complaining of sinus tarsi pain requiring subsequent removal of implant.

CONCLUSION

There is a role for either techniques in the treatment of symptomatic AAFD. LCL whilst more invasive has demonstrated superior outcome scores and lower complication rates at 24 months compared to STA. Patients need to be counselled appropriately to appreciate the benefits of each technique.

[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.

Mid-term Results of Subtalar Arthroereisis with Talar-Fit Implant in Pediatric Flexible Flatfoot and Identifying the Effects of Adjunctive Procedures and Risk Factors for Sinus Tarsi Pain

Objectives

To (i) report the mid‐term outcomes of subtalar arthroereisis using Talar‐Fit implant for the treatment of flexible flatfoot patients; (ii) compare clinical and radiographic outcomes between arthroereisis with and without adjunctive operative procedures to investigate the effects of adjuncts on the outcomes; and (iii) analyze the risk factors associated with sinus tarsi pain, which is the most common postoperative complication of arthroereisis.

Methods

Thirty‐one flexible flatfoot children and adolescents (46 feet) treated with subtalar arthroereisis using Talar‐Fit implant from June 2014 to May 2019 were retrospectively analyzed. The feet were divided into four treatment groups: (i) arthroereisis alone, (ii) arthroereisis with gastrocnemius recession, (iii) arthroereisis with Kidner procedure, and (iv) arthroereisis with gastrocnemius recession and Kidner procedure. Clinical function was evaluated based on the American Orthopaedic Foot and Ankle Society (AOFAS) ankle and hindfoot score. The following angles were measured for radiographic evaluation: talar‐first metatarsal angle, calcaneal pitch angle, and talar declination angle on the lateral view; and talar‐first metatarsal angle, talocalcaneal angle, and anteroposterior talonavicular coverage angle on the anteroposterior (AP) view. The paired Student's t‐test was used to compare the pre‐ and postoperative angular measurements and AOFAS scores. The Wilcoxon rank‐sum test was undertaken to determine the outcome differences among four treatment groups. Multivariate logistic regression analysis was used to analyze risk factors for sinus tarsi pain. P value <0.05 is considered statistically significant.

Results

The mean follow‐up of the feet was 32.8 months (range, 10–71 months). The mean AOFAS score significantly improved from 55.5 ± 14.5 preoperatively to 86.3 ± 9.9 (P < 0.001). Comparison of radiographic outcomes showed that the lateral talar‐first metatarsal angle decreased by a mean of 19.1° ± 11.9° (P < 0.001), the calcaneal pitch angle increased by a mean of 5.4° ± 3.4° (P < 0.001), the talar declination angle decreased by a mean of 14.8° ± 9.9° (P < 0.001), the AP talar‐first metatarsal angle decreased by a mean of 15.6° ± 10.3° (P < 0.001), the AP talocalcaneal angle decreased by a mean of 7.2° ± 8.3° (P = 0.001), and the AP talonavicular coverage angle decreased by a mean of 20.4° ± 9.0° (P < 0.001). There were no statistically significant differences with regard to AOFAS score and all angle measurements on both the AP and lateral views among the four treatment groups. There was one dislocation case caused by a fall 6 weeks after surgery, which was treated nonoperatively. The incidence of sinus tarsi pain was 13% and logistic regression analysis indicated that patients with a longer distance from the tail end of the implant to the lateral calcaneal wall had 38.8% greater odds of developing sinus tarsi pain.

Conclusions

The mid‐term clinical and radiographic results were satisfactory in patients who underwent the subtalar arthroereisis procedure using Talar‐Fit implant, alone or in combination with other adjuncts, for the treatment of flexible flatfoot.

Finite element analysis of subtalar joint arthroereisis on adult-acquired flexible flatfoot deformity using customised sinus tarsi implant

Background

Subtalar arthroereisis may cause sinus tarsi pain complications. In this study, we aimed to introduce a customised implant that facilitated treatment effect and less impingement. The biomechanical outcome between the intact and implant conditions was compared using finite element analysis.

Methods

A female patient with flatfoot (age: 36 years, height: 156 ​cm, body mass: 51 ​kg) was recruited as the model patient. The customised implant was designed from the extracted geometry. Boundary and loading conditions were assumed from the data of a normal participant. Four gait instants, including the ground reaction force first peak (25% stance), valley (45%), initial push-off (60%) and second peak (75%) were analyzed.

Results

The navicular height was elevated by 4.2% at 25% stance, whereas the strain of the spring, plantar cuneonavicular and plantar cuboideonavicular ligaments were reduced. The talonavicular joint force decreased and the calcaneocuboid joint increased by half and 67%, respectively, representing a lateralised load pathway. There was a stress concentration at the sulcus tali reaching 15.29 ​MPa

Conclusion

Subtalar arthroereisis using a customised implant may produce some positive treatment effects in terms of navicular height elevation, ligament strain relief and lateralised joint loading pathway. Although the concentrated stress at the sulcus tali did not exceed the threshold of bone breakdown, we could not rule out the potential of vascular disturbance owing to the remarkable elevation of stress. Future study may enlarge the contact area of the bone–implant interface by considering customisation based on the dynamic change of the sinus tarsi during walking gait.

The translational potential of this article

Geometry mismatch of prefabricated implants could be the reason for complications. With the advancement of 3D printing, customising implant becomes possible and may improve treatment outcome. This study implemented a theoretical model approach to explore its potential under a simulation of walking.

The effect of extra-osseous talotarsal stabilization (EOTTS) to reduce medial knee compartment forces - An in vivo study

Background

Excessive hindfoot pronation, talotarsal joint (TTJ) instability, has been attributed to an increase in medial knee compartment pathology. Advocacy for hindfoot realignment has been the subject of research. An internal solution for TTJ instability, extra-osseous talotarsal stabilization (EOTTS), exists but its effect on knee forces is unknown. This is the first study to measure the in vivo forces acting within the medial knee compartment before and after EOTTS. We hypothesized that following EOTTS there should be a reduction of force acting on the medial knee compartment.

Methods

10 fresh frozen cadaver lower extremities exhibiting clinical and radiographic evidence of TTJ instability were evaluated. The proximal femur segment was mounted to a mechanical testing unit. Pressure sensors were placed within the medial knee compartment. A force of 1000 newtons was then applied, and the femur was internally rotated 10 degrees. Measurements were recorded before and after the insertion of a type II EOTTS stent.

Results

Pre-EOTTS resulted in an average of 842 ± 247N acting within the medial knee joint compartment. These forces then decreased to an average of 565 ± 260N (<0.05) following EOTTS, representing an average reduction of force by 32.8%.

Conclusion

EOTTS has been shown to decrease the in vivo forces action within the medial knee compartment. This helps to further illustrate the importance of realigning and stabilizing the hindfoot for the prevention and treatment of chronic knee pain.

[Development and clinical application of ankle prosthesis]

OBJECTIVE

To review the development and clinical application of ankle prosthesis.

METHODS

The recent literature on ankle prosthesis design and clinical application was reviewed and analyzed.

RESULTS

Compared with the hip and knee prostheses, the ankle prosthesis develops slowly and has been developed to the third generation. The ankle joint has a special structure of multi-axis movement. The design of the first and second generations of prostheses is not conformed to the biomechanics of the ankle. The third generation of prosthesis is more conform to the characteristics of ankle biomechanics, with high postoperative survival rate and satisfactory clinical outcome.

CONCLUSION

At present, the survival rate of ankle prosthesis is low, and there is still much room for improvement in biomechanics, materials, and other aspects.

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.

Total talar replacement with a novel 3D printed modular prosthesis for tumors

Purpose

Arthrodesis is one of the most widely accepted surgical recommended methods for tumors of the talus, but it may be associated with poor limb functions. The aim of this study was to present a novel reconstruction with ankle function preserved after en bloc talus tumor resection.

Patient and method

A 43-year-old female with mesenchymal sarcoma of the talus was admitted in West China Hospital. Total talar replacement with three-dimensional (3D) printed modular prosthesis was prepared for reconstruction. The 3D printed modular prosthesis was designed exactly as the mirror image of the contralateral talus with complete filling of the sinus tarsi and subtalar joint space. The upper modular component of prosthesis was made of ultra high molecular weight polyethylene, and the lower component, titanium alloy. Pre-drilled holes in three directions were prepared for screw fixation of the subtalar joint.

Results

The patient underwent en bloc talus resection through anterior approach, followed by reconstruction with the 3D printed prosthesis. The whole procedure took 2 hours, and intra-operative blood loss was 50 mL. At the last follow-up, our patient was disease free and she could walk almost normally without any aid or pain. The Musculoskeletal Tumor Society score was 26/30. The American Orthopedic Foot and Ankle Society score was 91/100. The range of motion for dorsiflexion and plantar flexion was 40°. And no abnormalities were observed in the roentgenograph.

Conclusion

Total talar replacement with a 3D printed modular prosthesis may be an effective procedure for patients with tumors of the talus as it could maintain ankle function.

Arthroereisis: What Have We Learned?

One of the most common orthopedic problems in the authors' practice is flatfoot and, although it is most commonly treated conservatively, there is still lack of consensus about the type of surgical treatment that is best recommended in a specific patient. Keeping in mind that medial soft tissue reconstruction alone has not proved enough as an isolated procedure and that osteotomies and arthrodesis are considered more invasive surgery, arthroereisis is a quick, easy, and reproducible technique that seems to have good results without major complications in the correct patient. Indications, biomechanical principles, and technique are described in this article.

Results of subtalar arthroereisis for posterior tibial tendon dysfunction stage IIA1. Based on 35 patients

BACKGROUND

The aim of the study was to evaluate the clinical and radiological results obtained in the treatment of adult flexible flatfoot secondary to posterior tibial dysfunction with subtalar arthroereisis using a Kalix ^® endorthesis.

METHODS

35 patients (37 feet) were studied, having been operated between January 2010 and January 2015 for reducible flatfoot secondary to posterior tibial tendon dysfunction stage IIA1 of Bluman.

RESULTS

The average follow up was 47.52 months with a minimum of 14 months and a maximum of 75 months. The average age was 54.85, with an age range from 40 to 80 years old. In 74% of cases excellent or good results were obtained, according to our evaluation. The most common complication of this procedure was persistent pain in the sinus tarsi. 35% of cases in this group required implant removal for this reason.

CONCLUSIONS

We believe that arthroereisis is valid for the treatment of flat foot secondary to posterior tibial tendon dysfunction at this stage, giving a high percentage of good and excellent results.

The role of arthroereisis of the subtalar joint for flatfoot in children and adults

Subtalar arthroereisis has been reported as a minimally-invasive, effective and low-risk procedure in the treatment of flatfoot mainly in children but also in adults.It has been described as a standalone or adjunctive procedure, and is indicated in the treatment of flexible flatfoot, tibialis posterior tendon dysfunction, tarsal coalition and accessory navicular syndrome.Different devices for subtalar arthroereisis are currently used throughout the world associated with soft-tissue and bone procedures, depending on the surgeon rather than on standardised or validated protocols.Sinus tarsi pain is the most frequent complication, often requiring removal of the implant.To date, poor-quality evidence is available in the literature (Level IV and V), with only one comparative non-randomised study (Level II) not providing strong recommendations. Long-term outcome and complication rates (especially the onset of osteoarthritis) are still unclear. Cite this article: EFORT Open Rev 2017;2:438-446. DOI: 10.1302/2058-5241.2.170009.

Use of the arthroereisis screw with tendoscopic delivered platelet-rich plasma for early stage adult acquired flatfoot deformity

PURPOSE

Early stage adult acquired flatfoot deformity (AAFD) is traditionally treated with osteotomy and tendon transfer. Despite a high success rate, the long recovery time and associated morbidity are not sufficient. This study aims to evaluate the functional and radiological outcomes following the use of the arthroereisis screw with tendoscopic delivered PRP for early stage AAFD.

METHODS

Patients with stage IIa AAFD who underwent the use of the arthroereisis screw with tendoscopic delivered PRP with a minimum follow-up time of 24 months were retrospectively evaluated. Clinical outcomes for pain were evaluated with the Foot and Ankle Outcomes Score (FAOS) and Visual Analog Score (VAS). Radiographic deformity correction was assessed using weight-bearing imaging.

RESULTS

Thirteen patients (13 feet) with mean follow-up of 29.5 months were included. The mean age was 37.3 years (range, 28-65 years). FAOS-reported symptoms, pain, daily activities, sports activities, and quality of life significantly improved from 52.1, 42.6, 57.6, 35.7, and 15.4 pre-operatively to 78.5, 68.2, 83.3, 65.0, and 49.6 post-operatively, respectively (p < 0.05). Statistically significant radiographic improvements (lateral talus first metatarsal angle, calcaneal pitch, and cuneiform to ground distance) were also observed between the pre- and post-operative images.

CONCLUSIONS

This study elucidates the successful implementation of a less invasive approach to stage IIa AAFD. Through the use of a subtalar arthroereisis screw, PTT tendoscopy, and PRP injection, clinical and radiographic outcomes were improved.