Subtalar joint arthroereisis in adult-acquired flatfoot and posterior tibial tendon dysfunction

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.

The outcomes of subtalar arthroereisis in pes planus: a systemic review and meta-analysis

INTRODUCTION

Subtalar arthroereisis has been increasingly accepted as a solution to manage symptomatic pes planus. However, despite the recent developments related to arthroereisis, no other published literature has aimed to review the outcomes in paediatric patients since 2010. This systematic review and meta-analysis, therefore, aims to evaluate the current outcomes of subtalar arthroereisis in the treatment of symptomatic pes planus among the paediatric population.

MATERIALS AND METHODS

The review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. All studies reported on the clinical outcomes of subtalar arthroereisis in children aged 21 or younger were included.

RESULTS

A total of 17 publications were included, with 1536 feet. The average duration of follow-up of the studies included in the review is 43.52 months. The studies consistently reported improvement in the radiological outcomes, approximating that of a normal population. Subtalar arthroereisis has shown to restore the collapsed medial longitudinal arch, supported by the decrease in Meary's angle to 5.267° (95% CI: 4.695°-5.839°, normal: 0°-10.0°) post-operatively and an increased calcaneal pitch of 15.70° (95% CI: 15.41°-15.99°, normal 18.0°-20.0°). Deformities associated with pes planus such as heel valgus was also significantly reduced, evident by the post-operative lateral talocalcaneal angle of 27.19° (95% CI: 26.44°-27.93°, normal: 25.0°-45.0°) and a post-operative Kite's angle of 18.13° (95% CI: 17.73°-18.52°, normal: 15.0°-30.0°). Subjectively, subtalar arthroereisis has generally resulted in an improvement in the grading of outcomes postoperatively from the patient's point of view.

CONCLUSIONS

Subtalar arthroereisis could serve as a procedure to correct radiological abnormalities, as well as relieve pain in selected patients with symptomatic pes planus.

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

Subtalar joint arthroereisis (STA) can be used in the management of adult acquired flatfoot deformity (AAFD), including posterior tibial tendon dysfunction. The procedure is quick and normally causes little morbidity; however, the implant used for STA often needs to be removed because of sinus tarsi pain. The present study evaluated the rate and risk factors for removal of the implant used for STA in adults treated for AAFD/posterior tibial tendon dysfunction, including patient age, implant size, and the use of endoscopic gastrocnemius recession. Patients undergoing STA for adult acquired flatfoot were prospectively studied from 1996 to 2012. The inclusion criteria were an arthroereisis procedure for AAFD/posterior tibial tendon dysfunction, age >18 years, and a follow-up period of ≥2 years. The exclusion criteria were hindfoot arthritis, age <18 years, and a follow-up period of <2 years. A total of 100 patients (average age 53 years) underwent 104 STA procedures. The mean follow-up period was 6.5 (range 2 to 17) years. The overall incidence of implant removal was 22.1%. Patient age was not a risk factor for implant removal (p = .09). However, implant size was a factor for removal, with 11-mm implants removed significantly more frequently (p = .02). Endoscopic gastrocnemius recession did not exert any influence on the rate of implant removal (p = .19). After STA for AAFD, 22% of the implants were removed. No significant difference was found in the incidence of removal according to patient age or endoscopic gastrocnemius recession. However, a significant difference was found for implant size, with 11-mm implants explanted most frequently.

Plantar pressure distribution in a hyperpronated foot before and after intervention with an extraosseous talotarsal stabilization device-a retrospective study

Plantar pressure measurements have long been used by clinicians to provide information regarding potential impairments and disorders of the foot and ankle. Elevations in peak plantar pressures or a poor distribution of these pressures can be an indication of pathomechanics in the foot. Lower extremity deficits such as sensory impairment, foot deformities, limited joint mobility, and reduced plantar tissue thickness have been associated with high plantar pressures. The total pressures, pressure distribution, and peak pressures provide useful information to evaluate the abnormal functioning of the talotarsal joint. Instability of the talotarsal joint can result in excessive forces exerted on the joints and surrounding tissues in the foot that can then lead to dysfunction of the proximal musculoskeletal kinetic chain. In the present study, we performed a retrograde analysis of the pre- and postoperative measurements of the peak plantar pressures, peak forces, and area of contact between the foot and the ground during each phase of the gait cycle for 6 patients (12 feet) who had undergone a bilateral extraosseous talotarsal stabilization procedure using a type II extraosseous talotarsal stabilization device. After the procedure, a significant reduction was seen in the peak pressures (42%) over the entire foot and a significant increase in the contact area (19.7%) between the foot and the floor. This could imply that the extraosseous talotarsal stabilization procedure was effective in stabilizing the talotarsal joint complex, thus eliminating abnormal hindfoot motion and restoring the normal biomechanics of the foot and ankle complex, as indicated by a reduction and realignment of the peak plantar pressures and forces.

The underlying osseous deformity in plantar plate tears: a radiographic analysis

PURPOSE

Plantar plate tears can cause pain and deformity of the forefoot. The purpose of this study is to correlate common radiographic findings with observed intra-operative pathology in patients with plantar plate pathology.

METHODS

Bilateral weight-bearing radiographs were reviewed for 88 patients (106 feet) who underwent surgical repair of suspected plantar plate pathology. Parameters reviewed included the first intermetatarsal angle, the metatarsus adductus angle, the second and third metatarsophalangeal angles, splaying of the second and third toes, evaluation of the metatarsal parabola by 3 different methods, the first and second lateral declination angles, and the second lateral metatarsophalangeal angle.

RESULTS

Of 106 feet, 97 had intra-operative plantar plate tears. The radiographs of patients with plantar plate tears had an increased amount of digital splay on the anteroposterior radiograph compared to patients without pathology. For patients with unilateral plantar plate pathology, the metatarsal parabola of the symptomatic foot was compared with that of the asymptomatic foot. A significantly increased second metatarsal protrusion distance as measured by 2 different methods was noted in the symptomatic foot. Odds ratios revealed that patients with an intermetatarsal angle >12, medial deviation of the second toe, and splaying of the digits were more likely to be diagnosed with a plantar plate tear intra-operatively.

CONCLUSION

Although radiographs do not definitively diagnose plantar plate tears, understanding osseous forefoot architecture will aid with diagnosis in the absence of other osseous pathology. Furthermore, these data suggest that parabola should be corrected to maintain long-term correction of plantar plate pathology.

LEVEL OF EVIDENCE

Prognostic, Level II.

Retrospective analysis of the survivability of absorbable versus nonabsorbable subtalar joint arthroereisis implants

Subtalar joint arthroereisis is a surgical modality that has been shown to be an effective procedure for flexible flatfoot in both pediatric and adult populations. Despite advances in understanding its mechanics and function, complication and implant removal rates remain as high as 30% to 40%. Analysis was performed to determine the survivability of 2 subtalar joint arthroereisis implants, absorbable and nonabsorbable, used alone and in combination with other procedures in both the adult and pediatric populations. The 95 total arthroereisis procedures were analyzed in several major categories: absorbable implants versus nonabsorbable implants and adult versus pediatric patients. Each major group was then further subdivided to create further subgroups: absorbable isolated procedures, absorbable combined procedures, nonabsorbable isolated procedures, and nonabsorbable combined procedures. The overall survival rates were 83% for absorbable implants and 81% for nonabsorbable implants. A total of 11 (17%) absorbable implants and 6 (19%) nonabsorbable implants were removed, respectively, at an average of 9 months and 23 months postoperatively. When used alone and in combination with other procedures, 36% and 13% of absorbable implants and 18% and 19% of nonabsorbable implants, respectively, were removed. When comparing adult versus pediatric populations, the overall survival rates of the absorbable and nonabsorbable implants were 81% for absorbable implants and 79% for nonabsorbable implants in the adult population and 85% for absorbable implants and 100% for nonabsorbable implants in the pediatric population.

Outcome of modified Kidner procedure with subtalar arthroereisis for painful accessory navicular associated with planovalgus deformity

BACKGROUND

Type II accessory naviculars are frequently associated with planovalgus deformity. Operative treatment for patients recalcitrant to nonoperative treatment involves resection, with or without takedown, and reattachment of the tibialis posterior tendon as described by Kidner. This does not address the planovalgus deformity. The authors hypothesized that adding a subtalar arthroereisis to the Kidner procedure would lead to improvement of pain and function and correction of the deformity.

METHODS

Institutional Review Board-approved, prospectively collected data were reviewed for 20 patients (23 feet), who underwent a combined modified Kidner and subtalar arthroereisis for painful type II accessory navicular with planovalgus deformity recalcitrant to nonoperative treatment. The average age at the time of surgery was 18 years. Patients were evaluated preoperatively and at final follow-up clinically, radiographically, and via the visual analog pain scale (VAPS), the American Orthopaedic Foot and Ankle Society (AOFAS) ankle hindfoot score, and a satisfaction rating. Mean follow-up was 53.9 months.

RESULTS

The mean AOFAS scores improved from 53 preoperatively to 95 at final follow-up and the mean VAPS score decreased from 7.4 preoperatively to 1.7 at final follow-up. Radiographically, the average Meary's angle improved from 18.5° apex plantar preoperatively to 3° apex plantar on weight-bearing lateral radiographs, and the average talar head uncoverage percentage on weight-bearing anteroposterior radiographs improved from 24% preoperatively to 3%. Nineteen of 20 patients reported good or excellent results. Three patients required implant removal because of pain; no recurrence of planovalgus deformity occurred after implant removal. No patients developed subtalar arthritis.

CONCLUSION

The modified Kidner procedure combined with a subtalar arthroereisis resulted in significant pain and functional improvement. The deformity correction obtained at surgery was maintained even if the arthroereisis plug was removed. The extra-articular plug did not lead to subtalar arthritis.

Surgical treatment of hyperpronation using an extraosseous talotarsal stabilization device: radiographic outcomes in 70 adult patients

The purpose of this study was to determine radiographic correction achieved in adult patients treated with an extraosseous talotarsal stabilization (EOTTS) procedure. Patients diagnosed with flexible/reducible talotarsal joint dislocation (partial) underwent surgical correction with the HyProCure(®) EOTTS device. Preoperative and postoperative weightbearing radiographs taken in the anteroposterior (AP) and lateral views for a total 95 feet (in 70 patients) were analyzed to determine standardized radiographic angles, and to quantify the correction obtained after the EOTTS procedure. Postoperative radiographs were taken at an average follow-up of 17 days from the surgery date. The mean preoperative and postoperative talar second metatarsal angles (measured from the AP radiographs) were 24.8° ± 1.0° and 5.8° ± 0.9°, respectively, that is, mean decrease by 19°. The mean preoperative and postoperative talar declination angles (measured from the lateral radiographs) were 25.1° ± 0.7° and 19.4° ± 0.5°, respectively, that is, mean decrease by 5.7°. The mean preoperative and postoperative calcaneal inclination angles (measured from the lateral radiographs) were 21° ± 0.7° and 21.8° ± 0.7°, respectively, that is, mean increase by 0.8°. Postoperatively, the talar second metatarsal and talar declination angles were reduced to average values reported in the literature for normal feet. This study shows the efficacy of a minimally invasive EOTTS procedure in restoring the normal angular relationships between hindfoot and forefoot osseous structures on weightbearing, in both the transverse and sagittal planes. This indicates stabilization of the talotarsal joint complex and elimination of hyperpronation, which may lead to reduced pain, improved foot functional abilities, and patient satisfaction.

Extraosseous talotarsal stabilization devices: a new classification system

Displacement of the articular facets of talus on the tarsal mechanism, or partial talotarsal dislocation, is a condition seen in children, adult, and geriatric populations. A characteristic of this pathologic condition is a prolonged period of and excessive amount of pronation (hyperpronation) on weightbearing. The ill effects of this condition may lead to a multitude of other foot pathologies and to pathologies associated with the proximal lower extremity musculoskeletal structures. A variety of conservative and operative treatment options have been used to eliminate or minimize hyperpronation. Extraosseous talotarsal stabilization (EOTTS) devices have been used to realign and stabilize the articular facets of the talus on the tarsal mechanism, thereby attempting to restore the normal range of hindfoot motion while eliminating hyperpronation. A multitude of such devices, which are intended for the same purpose, are available for the surgeon to choose from. However, there is no literature discussing the differences among these devices, or the benefits of one device over the other. Based on current understanding and available knowledge base, the goal of this article was to classify EOTTS devices based on their design features and biomechanical functioning. A theoretical description of how these different types of devices function is laid out in an attempt to understand the reason for their success or failure. This new classification system is intended to help researchers and surgeons appreciate the subtle yet important differences among these devices, and to thus help them design future research studies when using these devices.

Subtalar arthroereisis and its role in pediatric and adult population

Subtalar joint arthroereisis is a surgical procedure that addresses symptomatic flexible flatfoot deformities using an extraarticular implant within the sinus tarsi. Three groups of implants have been developed for this procedure: self-locking wedges, axis-altering devices, and impact-blocking devices. The self-locking wedge implants are the focus of this article, relative to its use, limitations, and controversies in the pediatric and adult population.

Subtalar joint arthroereisis in the management of pediatric flexible flatfoot: a critical review of the literature

BACKGROUND

Pediatric flexible flatfoot is a common deformity for which a small, but significant number undergo corrective surgery. Arthroereisis is a technique for treating flexible flatfoot by means of inserting a prosthesis into the sinus tarsi. The procedure divides opinion in respect of both its effectiveness and safety.

METHODS

A database search up until 2010 was used to find articles regarding arthroereisis in pediatric patients. We summarized the findings of this study.

RESULTS

Seventy-six studies were identified. Eight of the nine radiographic parameters reported show significant improvement following arthroereisis reflecting both increased static arch height and joint congruency. Calcaneal inclination angle demonstrated the least change with only small increases following arthroereisis. Arthroereisis remains associated with a number of complications including sinus tarsi pain, device extrusion, and under-correction. Complication rates range between 4.8% and 18.6% with unplanned removal rates between 7.1% and 19.3% across all device types.

CONCLUSION

Current evidence is limited to consecutive case series or ad hoc case reports. Limited evidence exists to suggest that devices may have a more complex mode of action than simple motion blocking or axis altering effects. The interplay between osseous alignment and dynamic stability within the foot may contribute to the effectiveness of this procedure. Although literature suggests patient satisfaction rates of between 79% to 100%, qualitative outcome data based on disease specific, validated outcome tools may improve current evidence and permit comparison of future study data.

Arthroereisis of the subtalar joint: an uncommon complication and literature review

Arthroereisis is an operation to prevent abnormal pronation in the subtalar joint in children and adults with symptomatic flexible flatfeet. In the present report, we describe an uncommon late complication of a former variation of this procedure, namely the case of an adult male who experienced migration of a xenogeneic bone graft that had been implanted 55 years earlier. A thorough review of the existing data was also undertaken to better understand the complications of this procedure.

Evaluating plantar fascia strain in hyperpronating cadaveric feet following an extra-osseous talotarsal stabilization procedure

Abnormal talotarsal joint mechanics leading to hyperpronation is implicated as one of the most common causes of plantar fasciopathy. In patients with hyperpronating feet, the plantar fascia experiences excessive tensile forces during static and dynamic weight-bearing activities because of excessive medial longitudinal arch depression. For the purposes of this study, we hypothesized that plantar fascia strain in hyperpronating cadaveric feet would decrease after intervention with an extra-osseous talotarsal stabilization (EOTTS) device. A miniature differential variable reluctance transducer was used to quantify the plantar fascia strain in 6 fresh-frozen cadaver foot specimens exhibiting flexible instability of the talotarsal joint complex (i.e., hyperpronation). The strain was measured as the foot was moved from its neutral to maximally pronated position, before and after intervention using the HyProCure(®) EOTTS device. The mean plantar fascia elongation was 0.83 ± 0.27 mm (strain 3.62% ± 1.17%) and 0.56 ± 0.2 mm (strain 2.42% ± 0.88%) before and after intervention, respectively (N = 18, variation reported is ± 1 SD). The average plantar fascia strain decreased by 33%, and the difference was statistically significant with p < .001. From this cadaveric experiment, the reduction in plantar fascia strain suggests that an EOTTS device might be effective in stabilizing the pathologic talotarsal joint complex and the medial longitudinal arch and in eliminating hyperpronation. An EOTTS procedure might offer a possible treatment option for plantar fasciopathy in cases in which the underlying etiology is abnormal talotarsal biomechanics.

Effect of extra-osseous talotarsal stabilization on posterior tibial tendon strain in hyperpronating feet

Posterior tibial tendon dysfunction is considered one of the most common causes of progressive adult acquired flatfoot deformity. The etiology leading to the dysfunction of posterior tibial tendon remains controversial. The purpose of this study was to quantify strain on the posterior tibial tendon in cadaver feet exhibiting hyperpronation caused by flexible instability of the talotarsal joint complex. We hypothesized that posterior tibial tendon strain would decrease after a minimally invasive extra-osseous talotarsal stabilization procedure. A miniature differential variable reluctance transducer was used to measure the elongation of posterior tibial tendon in 9 fresh-frozen cadaver specimens. The elongation was measured as the foot was moved from its neutral to maximally pronated position, before and after intervention with the HyProCure(®) extra-osseous talotarsal stabilization device. The mean elongation of the posterior tibial tendon (with respect to a fixed reference point) was found to be 6.23 ± 2.07 mm and 3.04 ± 1.85 mm, before and after intervention, respectively (N = 27; variation is ± 1 SD). The average elongation reduced by 51% and was statistically significant with p < .001. Strain on the posterior tibial tendon is significantly higher in hyperpronating feet. An extra-osseous talotarsal stabilization procedure reduces excessive abnormal elongation of the posterior tibial tendon by minimizing excessive abnormal pronation. This minimally invasive procedure may thus provide a possible treatment option to prevent or cure posterior tibial tendon dysfunction in patients exhibiting flexible instability of the talotarsal joint complex.

Identifying risk factors in subtalar arthroereisis explantation: a propensity-matched analysis

A case-control study was undertaken to identify differences in patients with flexible flatfoot deformity who required explantation of subtalar arthroereisis compared with those who did not. All patients who required removal of a self-locking wedge-type subtalar arthroereisis were identified between 2002 and 2008. Propensity scores matched 22 explanted subtalar arthroereises to 44 controls (nonexplanted arthroereises), resulting in a total of 66 implants that met all inclusion and exclusion criteria. Multivariate logistic regression found that patients who required explantation had a greater odds of radiographic undercorrection, determined from radiographic anteroposterior talar-first metatarsal angles postoperatively, P = .0012, odds ratio (OR) = 1.175 (95% confidence interval [CI] 1.066 to 1.295), or residual transverse plane-dominant deformities, as determined from radiographic calcaneocuboid abduction angles postoperatively, P = .05, OR = 1.096 (95% CI 1.06 to 1.203). Patients with smaller postoperative anteroposterior talocalcaneal angles had a 16.7% reduction in odds for arthroereisis explantation (P = .0019) (95% CI 6.5% to 25.8%). Age, gender, implant size, shape, duration, implant position, surgeon experience, and concomitant procedures were not statistically different between the 2 groups. This study helps identify key factors that may result in subtalar arthroereisis explantation.

Radiographic evaluation of navicular position in the sagittal plane-correction following an extraosseous talotarsal stabilization procedure

The navicular drop in the sagittal plane on weight-bearing is a valid indicator of foot pronation. Dislocation of the talus on the tarsal mechanism results in hyperpronation, which can lead to excessive navicular drop. The purpose of the present study was to radiographically determine the efficacy of HyProCure(®) in realigning the navicular bone in hyperpronating feet. We hypothesized that following the placement of HyProCure(®), the navicular height would increase significantly compared to its preoperative value. Radiographs of 61 adult patients (86 feet) who received HyProCure(®) without adjunctive hindfoot or midfoot soft tissue or osseous procedures were analyzed. The distance of the navicular with respect to the cuboid was measured from the pre- and postoperative weight-bearing lateral radiographs. Additionally, we measured foot length to normalize the navicular to cuboid distance. The postoperative radiographs were taken at an average follow-up of 17 days. The mean preoperative true navicular to cuboid distance was 19 ± 6 mm as compared to a mean postoperative value of 24 ± 5 mm. The mean pre- and postoperative normalized navicular to cuboid distances were 0.098 ± 0.029 and 0.125 ± 0.027, respectively (± 1 SD). The postoperative increase in the true and normalized navicular to cuboid distance was statistically significant (p < .001). HyProCure(®) was effective in improving the anatomic alignment of the talonavicular joint by reducing excessive navicular drop. This indicates reduction of excessive abnormal pronation and stabilization of the medial column of the foot, which can also lead to reduction in the excessive forces placed on the supporting soft tissue structures.

Revision of failed flatfoot surgery

Revision of failed flatfoot surgery presents a unique and challenging dilemma for the foot and ankle surgeon. Revision surgery is focused on establishing a plantigrade foot with correction of the hindfoot valgus, midfoot abduction, and forefoot varus. Successful reconstruction of failed flatfoot surgery begins with a proper evaluation. No treatment algorithm exists for the management of the malaligned flatfoot. Patient complaints, an understanding of the initial deformity and biomechanical problems, and surgeon experience play a role in correction of failed flatfoot surgery.