Flatfoot Deformity Research Articles

Joint-preserving surgical correction of advanced flexible planovalgus deformity of the adult foot

Adult acquired flatfoot deformity is characterized by aprogressive functional deficit of the foot that leads to an eversion of the subtalar joint complex with heel valgus, abduction of the forefoot and collapse of the medial arch. In the case of aflexible deformity, ajoint-preserving operative reconstruction is advisable, which should correct all elements of the deformity. Acalcaneal lengthening osteotomy can correct excessive abduction of the forefoot, which can be measured by the amount of talar head uncoverage visible on AP weight-bearing x‑rays of the foot. Any calcaneal lengthening osteotomy leads to an incongruence between talar and calcaneal joint surfaces of the subtalar joint, which is arisk factor for secondary degenerative changes. It is, therefore, advisable to limit the amount of lengthening to thenecessary minimum. Aresidual heel valgus can be corrected by an additional medial displacement osteotomy as adjunct to the calcaneal lengthening. Calcaneal osteotomies are usually part of acomplex reconstruction of advanced but still flexible adult flatfoot deformities. In addition to the correction of the hindfoot deformity, persistent forefoot supination needs to be corrected. In cases of midfoot instability, which is frequently located in the naviculo-cuneiforme joint line, acorrective arthrodesis is recommended. Without midfoot instability forefoot aCotton osteotomy is able to reduce forefoot supination and add to reconstruction of the medial arch of the foot. All bony corrections should be combined with soft tissue reconstruction, i.e. spring ligament repair, Flexor tendon transfer and, in cases of gastrocnemius shortening, agastroc recession.

Medial Displacement Calcaneal Osteotomy as a Novel Treatment for Recurrent Pain after Kidner Procedure for Accessory Navicular Syndrome

Category:Hindfoot; Midfoot/ForefootIntroduction/Purpose:The accessory navicular is often considered to be related to flatfoot deformity. While the Kidner procedure is commonly utilized in treating painful accessory navicular, its ability to correct flatfoot deformity is debated. Patients may also have recurrent pain due to increased tension of the posterior tibial tendon (PTT) in the setting of an uncorrected flatfoot. In the literature, both PTT lengthening and tendon transfer are techniques described to address this issue with varying success and outcomes. Because medial displacement calcaneal osteotomy (MDCO) is a powerful procedure capable of reducing tension of the medial column and correcting hindfoot valgus deformity, we investigated its use in addressing these symptoms. We report outcomes of a novel use of MDCO in treating patients with recurrent pain following Kidner procedure.Methods:We retrospectively identified 21 patients who underwent MDCO for recurrent pain after Kidner procedure at our institution. MDCO was indicated when patients failed to perform single heel raise due to pain at the PTT attachment site at minimum 6 months following index surgery. Pre- and postoperative radiographic parameters were measured: lateral talo-1st metatarsal angle (Meary’s), talonavicular coverage angle (TNC), calcaneal pitch (CP), and hindfoot moment arm (HMA). Using previously validated cut-offs in describing flatfoot deformity, a Meary’s angle less than -4 degrees was considered a flattened arch, and a HMA more than 3.2mm was considered a valgus heel deformity. Measurements were also performed in x-rays of the contralateral foot to determine whether foot deformity in the involved foot was attributed to Kidner procedure or a preexisting deformity. Pre- and postoperative visual analogue scale (VAS) and FAOS outcome scores were compared to assess for improvement in patient-reported outcomes.Results:The mean age was 25.7 years (range, 21-49) and the mean follow-up was 20.1 months (range, 14-26). The average time from the index surgery was 7.3 months (range, 6-10). Average size of the accessory navicular before excision was 11 mm (range, 4.6-18.3). Concomitant procedures included medial head gastrocnemius recession (n=11), plantarflexion osteotomy of first metatarsal bone (n=1), and talocalcaneal coalition excision (n=1). Radiographically, 12 patients (57%) had a flattened arch and all patients (100%) had heel valgus deformity. All radiographic parameters except Meary’s angle (p=0.885) improved postoperatively. Contralateral radiographs revealed that fifteen patients (71%) had a flattened arch, and 19 patients (90%) had heel valgus deformity. There were no differences between both sides. VAS and FAOS improved significantly (p <0.001).Conclusion:Our data suggest that recurrent pain after Kidner procedure may be related to unaddressed preexisting hindfoot valgus deformity. MDCO provided satisfactory outcomes in relieving this symptom without performing surgery to the PTT. Therefore, MDCO can be a viable option for treatment of recurrent pain following Kidner procedure while potentially avoiding loss of inversion power and donor-site comorbidities associated with PTT lengthening and tendon transfer.

Radiographic Outcomes, Union Rates, and Complications Associated with Implants Positioned on the Plantar Bone Surface for Midfoot Arthrodesis

Category:Midfoot/Forefoot; TraumaIntroduction/Purpose:Midfoot fusions have long been used to treat a variety of procedures in the foot. Indications may include hallux valgus correction, first ray instability, midfoot arthritis, pes planovalgus, trauma, and Charcot reconstruction. One of the drawbacks of this procedure is nonunion, which has been consistently reported between 5-10%. Placing implants and obtaining fixation along the plantar surface of the bone may create a tension band implant construct during physiologic loading that helps to compress the arthrodesis site and thereby may further optimize the healing potential. This study reports on the radiographic and clinical outcomes of plantar plating and arthrodesis of midfoot joints for a variety of procedures.Methods:A retrospective review was undertaken of consecutive patients between 2012-2019 that underwent a midfoot fusion with plantar positioned implants by a fellowship-trained foot and ankle orthopedic surgeon at a single institution. 62 patients underwent arthrodesis of the midfoot as part of a correction for hallux valgus, flatfoot deformity, midfoot arthritis, Lisfranc injury, Charcot correction or a combination these diagnoses. Average follow-up was 36.2 months (range, 16-66 months). For those treated for a flatfoot deformity, the lateral talus-first metatarsal (Meary’s) angle and medial arch sag angle (MASA) were compared on preoperative and postoperative imaging to obtain the magnitude of radiographic correction achieved. For those treated for hallux valgus deformity, the inter-metatarsal angle (IMA) was utilized to establish the magnitude of deformity correction. Serial weight-bearing radiographs were independently evaluated for malunion, nonunion, or hardware migration to be logged as complications at the arthrodesis site.Results:The 1st TMT joint was fused in 43 patients, and the NC joint was fused in 23 patients. Five patients had simultaneous fusion of the 1st TMT and NC joints. Two patients underwent arthrodesis of the talonavicular (TN) joint with one patient having simultaneous arthrodesis of the TN and NC joints. We found statistically significant improvement in the lateral talus-first metatarsal-angle (Meary’s) and medial arch sag angle (MASA) for those treated for flatfoot corrections. For those treated for hallux valgus, there was significant reduction in the Intermetatarsal angle (IMA) from 15.4 to 6.8 degrees. The overall nonunion rate was 6.45% in all patients. The nonunion rate was reduced to 3.3%when excluding the Charcot neuroarthropathy patients.There was one symptomatic nonunion requiring revision surgery (1.7%).Conclusion:Deformity correction was successfully maintained in those treated for hallux valgus and flatfoot deformities. There were significant improvements in the IMA, the MASA, and Meary’s angle Plates implanted on the plantar bone surface for midfoot arthrodesis provided and maintained deformity correction without hardware irritation for a variety of orthopedic conditions. A clinical and radiographic union rate of94% (97% when excluding Charcot neuroarthropathy patients) was achieved. The risk of nonunion appeared to be higher in diabetic patients, in smokers, with the utilization of claw plates, and when fusion constructs included the NC joint.

Posterior vs. Middle Facet of the Subtalar Joint: The Search for an Early Sign of Peritalar Subluxation and Progressive Flatfoot Deformity

Category:Hindfoot; Ankle; OtherIntroduction/Purpose:Adult acquired flatfoot deformity (AAFD) is a three-dimensional (3D) and complex pathology that is characterized by peritalar subluxation (PTS) of the hindfoot. Measuring the amount of subluxation of the subtalar joint at the posterior facet was described and utilized for many years as a marker of PTS. The subluxation of the middle facet was recently proposed as possibly a more accurate and reliable early marker of pronounced deformity, with almost 100% sensitivity and specificity for symptomatic AAFD. The objective of this study was to compare the amount of subluxation of both the medial and posterior facets in patients with increased hindfoot valgus and controls.Methods:In this IRB-approved retrospective comparative study, we included a total of 91 patients with AAFD (108 feet) who underwent standing weightbearing CT (WBCT) as a standard baseline assessment of their foot deformity. One blinded Fellowship- Trained Orthopedic Foot and Ankle Surgeon with more than 10 years of experience performed WBCT measurements regarding the amount of subluxation of the subtalar joint (percentage of uncoverage) at the posterior and middle facet, as previously described in the literature (Please see attached Figure). Measurements were performed at the sagittal midpoint of the articular facets using Coronal Plane WBCT images. The inter-method agreement between the posterior and middle facet subluxation was assessed using Spearman’s Correlation and Bivariate Analysis. A paired comparison of the measurements was performed using Wilcoxon. P-values of <0.05 were considered significant.Results:The inter-method Spearman’s correlation between the subluxation of posterior and middle facets was measured 0.69. In a bivariate analysis, both measurements were found to be significantly and linearly correlated (P<0.0001), (R2=0.5). The mean/median value and 95% Confidence Interval (CI) for subluxation of the subtalar joint facets were found to be more pronounced in the middle facet (29.8%/26.8%, CI 25.7% to 33.9%) when compared to the posterior facet (12.5%/15.1%, CI 8.4% to 16.6%), p-value <0.0001. The median difference between the measurements (Hodges-Lehman factor) was found to be 12.8% higher subluxation in the middle facet (CI 6.6 to 21.2%).We also found that for each 1% increase in the amount of posterior facet subluxation, a 1.7 times higher subluxation could be expected in the middle facet.Conclusion:This study is the first to compare measurements of the amount of subluxation of the posterior and middle facets of the subtalar joints as markers of peritalar subluxation in patients with AAFD. We found a positive and linear correlation between the measurements, with the middle facet subluxation being significantly more pronounced than the posterior facet by an average of almost 13%. Our results are consistent with the idea that the middle facet subluxation might represent an earlier sign of pronounced and progressing peritalar subluxation in patients with adult acquired flatfoot deformity.Figure 1.

Outcomes of Flexible Flatfoot Deformity Reconstruction in the Young Patient

Category:Hindfoot; Midfoot/ForefootIntroduction/Purpose:Surgical correction of the collapsing flatfoot deformity has been well studied in the literature, with the average patient being a female in her 50s. While reconstruction of the flexible, symptomatic flatfoot in children and adolescents has been described, assessment of outcomes across age groups is limited. Therefore, the purpose of our study is to compare the clinical and radiographic outcomes in younger patients 30 years or less undergoing flatfoot reconstruction with that of older patients. In addition, the procedures performed for reconstruction and the incidence of subsequent reoperations were compared between the two groups.Methods:Ninety-four feet (51 left, 43 right) in 87 patients who underwent reconstruction for flexible collapsing flatfoot deformity were divided into 2 groups based on age: <= 30 years (n=22), and >30 years (n=72). Exclusion criteria included tarsal coalition or neuromuscular disease. Average age and BMI was 20.8 years (range, 13 to 30) and 26.8 (range, 18 to 38) in the younger cohort, and 57.5 years (range, 35 to 81) and 29.8 (range, 18 to 46) in the older cohort. Preoperative and minimum 2-year postoperative PROMIS scores were compared. Average follow-up was 30.6 and 27 months in the younger and older cohorts, respectively. We assessed five radiographic parameters both preoperatively and postoperatively, including talonavicular (TN) coverage angle, lateral talo-first metatarsal angle (Meary’s), lateral talocalcaneal angle, calcaneal pitch, and hindfoot moment arm (HMA). Operative reports and hospital records were reviewed to compare procedures performed for reconstruction as well as subsequent reoperations.Results:Younger patients demonstrated significant preoperative to postoperative improvements in Physical Function (p=0.01), Pain Interference (p<0.01), and Pain Intensity (p<0.01), with significantly greater improvement in Physical Function by 4.2 points (95% CI = 0.9 to 7.6, p=0.01) compared to the older cohort. All radiographic parameters demonstrated significant improvement (p<0.01) with no differences between the two groups. Younger patients were more likely to undergo Cotton osteotomy and deltoid ligament repair (p=0.01), and less likely to undergo flexor digitorum longus transfer, first tarsometatarsal fusion, spring ligament repair, and posterior tibial tendon repair (p<0.01). There were 8 (36.4%) reoperations in the younger group with painful hardware removal (ROH), and 27 (37.5%) in the older group (1 conversion to triple arthrodesis, 3 non-unions, 4 repeat medializing calcaneal osteotomies, 19 ROH).Conclusion:While the approach to surgical correction of younger patients with symptomatic, collapsing flatfoot deformity is similar to that of older adult patients, our data suggest that age may play a role in clinical outcomes, procedures indicated, and subsequent corrective reoperations. These findings point towards the efficacy of surgical correction in addressing this symptomatic pathology at a younger age.

Relationship Between Middle Facet Peritalar Subluxation and the Severity of Flatfoot Deformity

Category:Hindfoot; Midfoot/Forefoot; OtherIntroduction/Purpose:Recent literature has established the middle facet of the subtalar joint as a reliable and accurate marker of pronounced peritalar subluxation (PTS) in Adult Acquired Flatfoot Deformity (AAFD) patients. The Foot and Ankle Offset (FAO) has also been accepted as a more complete and three-dimensional (3D) measurement of foot collapse and hindfoot valgus. To date, no assessment has been made regarding the relationship between the severity of the AAFD and the amount PTS measured at the middle facet. The objective of this study was to investigate the correlation between these variables. We hypothesized that direct positive linear correlation would be found, with significantly increased middle facet joint incongruence and subluxation in patients with more pronounced hindfoot valgus and foot collapse.Methods:In this IRB-approved retrospective comparative study, we included 76 feet (42 left, 35 right) with symptomatic AAFD who underwent standing weightbearing CT (WBCT) as standard baseline assessment of their foot deformity. One blinded fellowship-trained foot and ankle surgeon with more than 10 years of experience performed measurements using multiplanar reconstruction (MPR) WBCT images. Manual measurements of subluxation and incongruence of the middle facet were performed at the anteroposterior midpoint of the articular facet. Semiautomatic calculation of the FAO was performed after 3D coordinate harvesting of the weightbearing points of the first, fifth metatarsal and calcaneus as well as the center of the ankle. Correlation of FAO severity and subluxation/incongruence of the middle facet was assessed by Spearman’s correlation and bivariate analysis. Paired Wilcoxon was utilized to compare FAO values in congruent (0% subluxation), subluxated (1-99% subluxation) and dislocated middle facets. P-values <0.05 were considered significant.Results:No significant direct correlation was observed between FAO and Middle Facet Incongruence angle (p=0.12). However, positive linear correlation was found between middle facet subluxation and FAO (Spearman’s 0.54, R2 0.29, p<0.0001). The subluxation of the middle facet was found to increase by 3.5% for every one-point FAO increase (Middle Facet Subluxation (%) = 6.903202 + 3.5452074*Foot and Ankle Offset). Mean values and confidence intervals (CI) of FAO were significantly different depending on the congruency of the middle facet (p=0.0003): congruent, 5.2 (CI, 3.4 to 7.0), subluxated, 8.7 (CI, 6.8 to 9.0) and dislocated, 12.9 (CI, 9.8 to 15.9). Similarly, middle facet subluxation was also found to progressively and significantly increase when FAO values were staged from zero (normal alignment) to four (FAO>20) (p<0.0001).Conclusion:This study is the first to compare and correlate measurements regarding the amount of subluxation of middle facet with the severity of AAFD, when measured by the foot and ankle offset (FAO). We found a significant, positive and linear correlation between the amount of subluxation of the middle facet and FAO measurements. No correlation was found between the incongruence angle of the facet and FAO. Our results support the concept of using the subluxation of the middle facet of the subtalar joint as a key marker of early and progressive deformity in patients with AAFD.

Contribution of First Tarsometatarsal Joint Fusion to Deformity Correction in the Treatment of Adult Acquired Flatfoot Deformity

Category:Midfoot/Forefoot; OtherIntroduction/Purpose:Severe adult-acquired flatfoot deformity (AAFD) is often associated with painful medial column collapse at the naviculocuneiform (NC) joint. The purpose of this study was to examine the role of first tarsometatarsal (1st TMT) fusion combined with subtalar fusion in correcting deformity at this joint.Methods:We retrospectively analyzed 40 patients (41 feet) who underwent 1st TMT and subtalar (ST) fusion as part of a flatfoot reconstructive procedure. We assessed six radiographic parameters both preoperatively and at a minimum of 6 months postoperatively, including talonavicular (TN) coverage angle, lateral talo-first metatarsal angle, lateral talocalcaneal angle, calcaneal pitch, hindfoot moment arm, and a newly defined navicular-cuneiform incongruency angle (NCIA). Patient-Reported Outcomes Measurement Information System (PROMIS) clinical outcomes were assessed preoperatively and at a minimum 1 year follow-up.Results:The NCIA demonstrated excellent interobserver reliability, with no significant change between pre- and postoperative measurements. All other radiographic parameters, except calcaneal pitch, demonstrated statistically significant improvement postoperatively (p <0.01). Overall, patients had statistically significant improvement in all PROMIS domains (p <0.01), except for depression. Worsening NC deformity was not associated with worse patient-reported outcomes.Conclusion:Our data suggests that when addressing collapse of the medial arch in patients with AAFD, fusion of the 1st TMT joint in combination with other procedures leads to acceptable radiographic and clinical outcomes. There was no change in deformity at the NC joint at short-term follow-up, and patients achieved significant improvement in multiple PROMIS domains. Based on our findings, deformity through the NC joint does not significantly impact clinical outcomes. In addition, the NCIA was established as a reliable radiographic parameter that can be used to assess NC deformity in the presence of talonavicular and/or 1st TMT fusion.

Lateral Column Lengthening Versus Medial Displacement Calcaneal Osteotomy in Stage II Tibialis Posterior Tendon Dysfunction: Randomized Controlled Trial

Category:Hindfoot; Midfoot/ForefootIntroduction/Purpose:Adult acquired flatfoot deformity is a complex deformity associated with the collapse of the medial longitudinal arch. Several factors have been proposed in the etiology of adult acquired flatfoot deformity including arthritic, neuromuscular, and traumatic conditions; however, posterior tibial tendon dysfunction remains the most common etiology. A spectrum of conditions affecting the posterior tibial tendon has been identified, with tendinitis occurring early in the disease process and tendon rupture occurring at the more advanced stages. Adult-acquired flatfoot deformity requires a complex operative plan that often utilizes several procedures to correct deformity, at both the hindfoot and midfoot. The objective of this study was to compare the efficacy of two different osteotomies commonly used to correct flexible flat feet.Methods:42 Patients (21 males and 21 females) with stage II PTTD acquired flexible flatfeet were included with a mean age of 49.62 +- 6.2. Twinty-two patients had medial displacement calcaneal osteotomy (MDCO) while 20 cases had latercal column lenghtening (LCL). Strayer procedure, spring ligament plication and FDL transfer were done in all patients. Pre- and Post-operative clinical assessment was done using AOFAS and FFI questionaire. Six radiographic parameters were analyzed, two in the anteroposterior view ( talo-navicular coverage and talo-calcaneal angle), three in lateral view ( talo- first metatarsus angle, talo- calcaneal angle and calcaneal inclination angle) and tibio-calcanal angle in axial view.Results:At a mean follow up of 12 months, significant improvement in AOFAS and FFI scores in MDCO and LCL groups with no significant difference between both groups. Postoperative significant improvements in all radiographic measurements in both groups. LCL group showed significant better correction in TNC and calcaneal inclination angles when compared to MDCO group. However, MDCO procedure showed significantly better correction in axial tibial calcaneal angle. Both techniques correct the deformity, however cases received LCL has better correction than MDCO cases and less reoperation rate.Conclusion:Reconstructions performed with LCL produced a greater change in the realignment of adult acquired flatfoot, maintained more of their initial correction over time, and were associated with a lower incidence of additional surgery than reconstructions with a MDCO of the calcaneus. However, a higher incidence of degenerative change in the hindfoot was observed in the LCL group. The ability of LCL to correct the deformity in anteroposterior and lateral plan and MDCO in lateral and axial plan suggests that proper osteotomy should be planned according to the existing deformity. Combination of both techniques may be required in certain cases.

Radiographic Union of Evans Osteotomy Without Fixation

Category:Hindfoot; OtherIntroduction/Purpose:The Evans osteotomy is a lateral column lengthening procedure of the calcaneus that is commonly used to correct flexible flatfoot deformities. There is no consensus on whether fixation is needed to avoid nonunion and calcaneocuboid subluxation when performing this osteotomy. We assessed the nonunion rate and correlated extent of subluxation with graft size in an unfixed Evans osteotomy with an allograft wedge and no pinning of the calcaneocuboid joint at any point in the largest series of the procedure to date. Surgeries were performed in patients undergoing flexible flatfoot reconstruction.Methods:We retrospectively reviewed 120 consecutive patients who had undergone 145 unfixed Evans osteotomies by a single surgeon with allogenic bone graft for flatfoot reconstruction between January 2013 and October 2017, with a mean follow-up of 62.5 (range 9.4-266.7) weeks. The calcaneocuboid joint was not pinned during the procedure. Data were collected using clinical and radiographical examination during regular follow-up.Results:A total of 137 feet (94.5%) underwent a double calcaneal osteotomy with an associated medial displacement calcaneal osteotomy (MDCO). There was one nonunion (0.69%). The mean time to union was 10.8 (range, 6.7-17.9) weeks. There was significant improvement in all radiographic parameters postoperatively, including calcaneal pitch, talonavicular uncoverage, anteroposterior and lateral talo-first metatarsal angle, lateral column length, and naviculocuboid overlap (p<0.05). Minor postoperative calcaneocuboid joint subluxation (1.51 +- 2.3 mm) occurred in 72 of 118 feet (61.0%) and had no correlation with wedge size (r=0.06; 95% CI, -0.13, 0.24; p=0.6).Conclusion:An unfixed Evans osteotomy for symptomatic flatfoot deformity resulted in a significant improvement in the radiographic alignment of the foot with an exceptionally rare nonunion rate. Detectable calcaneocuboid subluxation was common but minimal in extent and was not correlated with wedge size in this series in which wedges were less than 12 mm in the maximum dimension. This report represents the largest series of the Evans procedure to date.

Union Rates and Deformity Correction Using the Hintermann Osteotomy in Type IIb Flatfoot Deformity

Category:Ankle; HindfootIntroduction/Purpose:Multiple Lateral column lengthening procedures have been described for the correction of the abduction component of stage II flatfoot deformity. The Hintermann osteotomy, although technically difficult, offers powerful lengthening of the lateral column with low risk of violating the articular cartilage of the subtalar joint as compared to the more widely performed Evans osteotomy. This study reports on the radiographic and clinical outcomes of the Hintermann osteotomy performed by a single surgeon.Methods:Patients who underwent reconstruction for stage II flatfoot deformity with a Hintermann lateral column lengthening were restrospectively identified. The talus-1st metatarsal angle, percent talus uncoverage, calcaneal pitch, lateral column length, CC joint subluxation, and distance from CC joint to the osteotomy were measured on pre and postop radiographs. Radiographic union was also assessed. The Kellgren-Lawrence scale was used to assess degenerative changes at the ST, CC, and TN joints.Charts were reviewed for comorbidities, clinical evidence of union, time to protected weightbearing, time to unrestricted weightbearing, signs of peroneal irritation, clinical signs of osteoarthritis progression, and complications. A paired students t test was used to identify differences in radiographic parameters.Results:Twenty-six patients (30 feet) met inclusion criteria. All osteotomies achieved union with only 1 (1/30) instance of delayed union. Average duration before clinical and radiographic union was 12.6 weeks (9-37). The AP Talus-1st metatarsal angle decreased on average of 12.3 degrees (STD 9.1) (p<0.0001). Percent talus uncoverage decreased on average 17.7 percent (STD 11.5%) (p<0.0001). Subluxation at the CC joint was found to increase on average 1.63mm (STD 1.99) (p<0.01). Only 3 patients (10%) had radiographic progression of osteoarthritis at either the CC or ST joint. No patients showed clinical signs of osteoarthritis and none went on to fusion. One patient had lateral hardware pain necessitating plate removal.Conclusion:The Hintermann osteotomy is a powerful tool for lateral column lengthening. In this series there was significant correction of the preoperative abduction deformity with no nonunions. Degenerative changes in the surrounding hindfoot joints were rare. One benefit of the Hintermann osteotomy is its ability to preserve the articular cartilage of the anterior and middle facets.

Long-Term Patient Reported Outcomes after Correction of Traumatic Foot Drop

Category:Trauma; AnkleIntroduction/Purpose:There is limited literature on patient reported outcomes after tendon transfer for traumatic foot drop. The purpose of this study was to determine long-term patient reported functional outcomes after posterior tibialis tendon (PTT) transfer in patients with foot drop resulting from a traumatic common peroneal nerve injury.Methods:Between August 2006 to January 2019, 31 patients underwent PTT transfer for foot drop secondary to a traumatic injury to their common peroneal nerve at our institution. The average follow-up was 14 months. A retrospective chart review was performed to document physical exam measures and to review postoperative radiographs for changes in foot alignment. There were 17 out of the initial 31 patients available at a mean follow-up of 5.9 years who responded to a phone questionnaire, including the Foot and Ankle Ability Measure (FAAM) questionnaire, and questions on brace and assistive device use, activity level, and satisfaction with surgery.Results:Preoperatively, all patients had an equinus contracture with no dorsiflexion strength, abnormal gait, and used an ankle- foot orthosis (AFO) or pneumatic boot for ambulation. Postoperatively, the average ankle dorsiflexion strength was 4/5 with 28/31 patients reporting a normal gait and 26/31 not using a brace for ambulation. Postoperative radiographs did not show changes in alignment or progression to flatfoot deformity. For the subset of 17 patients who responded to the phone questionnaire, the mean FAAM ADL subscale score was 68.1 and the Sport subscale score was 52.1 at an average of 5.9 years after surgery. The majority of patients (76%) were very or quite satisfied with the outcome of surgery and 15/17 (88%) patients reported they would undergo the PTT transfer procedure again.Conclusion:Posterior tibialis tendon transfer for patients with foot drop secondary to a traumatic injury to their common peroneal nerve showed a high satisfaction rate and improvement in function after surgery without the need for brace or assistive device use at long-term follow-up at an average of 6 years. Additionally, there was no progression to flatfoot deformity after posterior tibialis tendon transfer at 1 year postoperatively.

Predictors of Spring Ligament Degeneration and Outcomes of Reconstruction during Correction of Adult Acquired Flatfoot Deformity

Category:Hindfoot; Midfoot/ForefootIntroduction/Purpose:It is currently unclear how injury to the spring ligament (SL) affects the preoperative presentation of adult acquired flatfoot deformity (AAFD). The purposes of this study were to retrospectively identify shared factors that could be used to preoperatively predict SL damage in patients undergoing AAFD correction as well as compare outcomes of patients undergoing SL reconstruction to those not undergoing reconstruction during AAFD correction.Methods:All patients undergoing operative correction of grade 2B AAFD secondary to tibialis posterior tendon dysfunction by a single fellowship-trained foot and ankle orthopaedic surgeon from 2011 to 2017 were reviewed. Operative reports were reviewed for the surgeon’s evaluation of the competency of the SL and to determine whether SL reconstruction was performed. Patient charts were reviewed for demographic information, preoperative Visual Analog Scale (VAS) pain level, and their Foot and Ankle Ability Measure (FAAM) Activities of Daily Living (ADL) and -Sports subscales. Preoperative radiographic parameters were assessed by a surgeon blinded to the intraoperative findings. Patient outcomes of VAS pain, FAAM-ADL, and FAAM-Sports were collected at a minimum of 24 months postoperatively. Multiple logistic regression analysis was performed to determine significant independent predictors of spring ligament tears.Results:The study included 115 feet undergoing corrective reconstruction, with 47 feet having a spring ligament tear (40.9%). Patients with tears were significantly older (p<0.001), with higher preoperative reported pain (p=0.01), and lower preoperative FAAM-ADL (p=0.04) and -Sports (p=0.006) scores than those without SL tears. Patients with a SLT demonstrated significant differences in AP talo-1st MT angle (p=.003), talonavicular uncoverage percentage (p<0.001), talonavicular angle (p=0.017), and Meary`s talo-1st MT angle (p=0.001). Based on multiple logistical regression analysis (odds ratio [95% confidence interval]), patient age (1.10 [1.03, 1.18]; p=0.003), talonavicular uncoverage percentage (1.35 [1.13, 1.60]; p<0.001), and talonavicular angle (0.82 [0.71, 0.96]; p=0.0133) were independently predictive of ligament degeneration. Patients undergoing SL reconstruction did not differ significantly in functional score improvements compared to those without reconstruction.Conclusion:Our findings suggest that a SLT is associated with more advanced flexible pes planovalgus, measured both by radiographic parameters as well as its impact on patient function. Increasing patient age, increasing talonavicular uncoverage percentage, and decreasing talonavicular angle are all independently associated with increased likelihood of patients with AAFD having a SLT. AAFD correction with concomitant SL reconstruction does not appear to influence absolute or changes in patient pain and function.

Pre-Operative Radiographic Parameters of Arch Collapse Do Not Predict Future Treatment Failure in Patients with Stage IIb Pes Planus

Category:Ankle; Hindfoot; Midfoot/ForefootIntroduction/Purpose:Adult-acquired flatfoot deformity (AAFD) is a complex pathology of the foot that often results from dysfunction of the posterior tibial tendon (PTTD) and encompasses a wide spectrum of deformity. A high-degree of continued morbidity following flatfoot reconstruction exists for which prognostic indicators of future poor outcomes are uncertain. AP and lateral weight-bearing radiographs are commonly utilized to assess the severity of deformity including forefoot abduction, medial arch collapse, and hindfoot valgus. However, the relationship between pre-operative radiographic severity of deformity and predilection for future surgical treatment failure remains uncertain. The purpose of this study was to perform pre-operative radiographic measurements of patients with stage IIb PTTD and determine which preoperative radiographic parameters, if any, predict future surgical treatment failure.Methods:Following IRB approval, an institutional electronic medical record database was queried from January 2000-2014 to identify all patients undergoing surgical correction for stage IIb PTTD. 256 patients with stage IIb PTTD underwent medial displacement calcaneal osteotomy and flexor digitorum longus transfer, with possible spring ligament repair and/or Achilles lengthening. Patients undergoing concomitant lateral column lengthening or midfoot fusion, patients with previous hardware, and patients with incomplete medical records were excluded. Preoperative radiographs were retrospectively analyzed to assess preoperative deformity. Talonavicular coverage angle was measured using AP radiographs. Lateral radiographs were used to measure talar-1st metatarsal angle (Meary’s) angle, calcaneal pitch and medial cuneiform-floor height. Patient charts were also reviewed to determine whether patients experienced treatment failure, defined as return to the operating room for unplanned revision surgery (e.g. broken/painful hardware, nonunion, residual deformity, infection, nerve damage, blood clot/DVT). The degree of pre-operative deformity was compared between treatment failure and non-failure groups.Results:Out of the 256 patient cohort, a total of 58 patients (22.7%) experienced treatment failure indicated by the need for an unplanned revision surgery, while 198 patients (77.3%) did not experience failure. There were no significant differences in the severity of pre-operative radiographic deformity between the treatment failure and non-failure groups including Meary’s angle (p = 0.93), calcaneal pitch (p = 0.70), talonavicular coverage angle (p = 0.99), and medial cuneiform height (p = 0.52, Table 1).Conclusion:The results of this study show that there is no significant difference in pre-operative radiographic deformity between patients who experienced failure versus non-failure following surgical flatfoot correction suggesting that the degree of pre- operative deformity is not significantly associated with an increased risk for future surgical failure. The analysis of these results, may underscore the relative importance of the physical exam in the evaluation of patients with symptomatic stage IIb PTTD and a relative lack of prognostic value in radiographic parameters commonly used to describe patients’ deformity.

Patient-Reported and Radiographic Outcomes in Primary and Revision Stage II, III, and IV Adult- Acquired Flatfoot Deformity Surgery

Category:Hindfoot; Midfoot/ForefootIntroduction/Purpose:Adult-Acquired Flatfoot Deformity (AAFD) is a progressive hindfoot and midfoot deformity that causes pain and disability. It presents as a plano-valgus deformity from the failure of static and dynamic medial osteoligamentous stabilizers. Stage II presents as a passively correctable, flexible deformity of the foot; stage III presents as a fixed or arthritic deformity of the foot; and stage IV presents with marked deformity of the foot caused by failure of the deltoid ligament and subsequent peritalar instability. Although operative treatment of AAFD is dependent on the stage, there is little data on patient- reported and radiographic outcomes stratified by primary versus revision stage II, III, and IV reconstruction surgery.Methods:Patient Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF) and Pain Interference (PI) scores were prospectively obtained on 46 consecutive patients who underwent AAFD reconstruction between November 2013 and January 2019 with minimum 12-month follow-up (average 23 months). Twenty patients underwent stage II reconstruction, 5 of which were revision surgeries; 19 patients underwent stage III reconstruction, 8 of which were revision surgeries; and 7 patients underwent stage IV reconstruction, all of which were primary surgeries. Radiographic correction was measured pre- and post-operatively and correlated with PROMIS scores. Measurements included the talonavicular uncoverage angle, talonavicular uncoverage percent, AP talo-first metatarsal angle, Meary’s angle, medial cuneiform height, and medial cuneiform-fifth metatarsal height.Results:For the overall cohort, PROMIS PF increased significantly from 37.6+-5.7 to 42.4+-6.8 (p=0.0014). PROMIS PI improved significantly from 64.7+-6.3 to 54.6+-9.5 (p<0.0001). PROMIS scores were not statistically different between AAFD stages. Change in PROMIS PI was significantly greater in primary (-12.3) versus revision (-3.7) surgery (p=0.0157). Change in PROMIS PF was non- significantly greater in primary (+4.0) versus revision surgery (+2.3). All radiographic measurements improved significantly (p<0.05). In primary stage II AAFD, pre-operative PROMIS PI scores correlated with pre-operative medial cuneiform-fifth metatarsal height (r = -0.606, p = 0.0479). In addition, in primary stage II AAFD, post-operative PROMIS scores correlated with post-operative medial cuneiform height (PROMIS PF: r=0.7725, p=0.0020; PROMIS PI: r=-0.5692, p=0.0446).Conclusion:Patient-reported and radiographic outcomes improve significantly after AAFD reconstruction. There was no significant difference in PROMIS scores between AAFD stages. However, stage III patients had non-significantly lower improvements in PROMIS PF, likely due to loss of function after arthrodesis. Primary operations had better patient-reported outcomes compared to revision operations. In primary stage II AAFD, reconstructing the medial arch correlates significantly with improvement in pain and functionality. This survey of outcomes after primary and revision stage II, III, and IV reconstruction should help clinical decision making by providing data on expected surgical improvement.

Minimally Invasive Surgery for Correction of Adult Acquired Flat Foot Deformity: An Anatomic Study

Category:Midfoot/Forefoot; HindfootIntroduction/Purpose:Adult acquired flatfoot deformity (AAFD) is a complex and chronic debilitating condition characterized by a decrease in the medial arch height and, in advanced stages, a decrease in the talonavicular coverage angle as the forefoot drifts into pronation and abduction. Operative treatment of stage II deformity has changed significantly over the past few decades. Joint sparing procedures which aim to realign the hindfoot and augment the diseased tibialis posterior tendon with the flexor digitorum longus transfer are commonly performed. The introduction of minimally invasive surgery (MIS) has been associated with smaller incisions, less blood loss, and quicker recovery times. The purpose of this study was to qualitatively and quantitatively observe the tendinous and neurovascular structures at risk with MIS AAFD osteotomy procedures in cadaveric feet.Methods:MIS technique was used to perform medial displacement calcaneal, Evans, and Cotton osteotomies on nine cadaveric feet under fluoroscopic guidance. The sural nerve, superficial peroneal nerve and its branches, deep peroneal nerve, dorsalis pedis artery, saphenous vein, and peroneal and extensor hallucis longus tendons were carefully dissected from each cadaveric foot and evaluated for injuries following the MIS osteotomy cuts. The distance from the osteotomy cuts and these anatomic structures were measured and recorded.Results:On average, the sural nerve was 8.4 mm and 9 mm from the calcaneal and Evans osteotomy sites, respectively. The intermediate dorsal cutaneous nerve was on average 68.3 mm and 41.1 mm from the calcaneal and Evans osteotomy sites, respectively. The peroneal tendons were on average 16.7 mm and 0 mm from the calcaneal and Evans osteotomy sites, respectively. The extensor hallucis was an average of 1 mm from the Cotton osteotomy site. There was a partial tear injury to the peroneus brevis in four of the cadaveric specimens at the Evans osteotomy site without complete laceration. There was no injury to the sural nerve, superficial peroneal nerve and its branches, saphenous vein, deep peroneal nerve, dorsalis pedis artery, or extensor hallucis longus tendon.Conclusion:Tendinous and neurovascular structures are at risk with MIS AAFD osteotomy procedures. Care should be taken with soft tissue handling and blunt dissection to decrease iatrogenic injuries to these structures. Specifically, extra care and recognition of the peroneal tendons during the Evans osteotomy may prevent damage, as this structure was at greatest risk among the three osteotomy cuts. Future research studies evaluating this technique and the functional outcomes in patients in a clinical setting is warranted. Surgical technique studies are underway to implement smaller, yet appropriate bone grafts through mini incisions.

Short-Term Complications Following Early Protected Weight Bearing after Flatfoot Reconstruction when Utilizing a Fibertape Device for Spring Ligament Reefing Augmentation

Category:AnkleIntroduction/Purpose:In an estimated 70% of cases of Adult Acquired Flatfoot Deformity (AAFD) reconstruction, the spring ligament is elongated and/or damaged. Spring ligament reefing can be performed through several techniques including augmentation with Fibertape devices. In addition, biomechanical studies have demonstrated its safety and suggest early weight bearing may be performed. The purpose of this study is to evaluate the outcomes of early weight bearing following flatfoot reconstruction with use of InternalBrace augmentation for spring ligament reefing when performed in combination with medical displacing calcaneal osteotomy (MCO) and FDL tendon transfer.Methods:From 2016-2018, 45 patients underwent flatfoot reconstruction (MCO, FDL transfer, and gastrocnemius recession) with spring ligament reefing and augmentation with the InternalBrace device. All surgeries were performed by the senior orthopaedic surgeons (PJJ & MCA). Institutional early post-operative weight bearing protocol involves weight bearing as tolerated in a splint with crutches for two weeks, transitioning at 2 weeks to a Cam boot with 1 wedge WBAT. At 4 weeks, the patient is weaned off crutches and recommended to start therapy restricting excessive eversion and concentrating on calf strengthening, gait, and ROM. At weeks 6-8 they are weaned from the Cam boot into lace up ASO and shoe with arch support. Data were recorded at 2 weeks, 6 weeks, 12 weeks, 6 months and at yearly intervals. Outcomes and complications were documented.Results:Of the 45 cases there were no complications related to early weight bearing. Radiographic bony union rate of the MCO was 100% (45/45). Moreover, there was no loss of fixation of either the FDL transfer or spring ligament reefing with InternalBrace augmentation with early weight bearing. Lastly, radiographic evaluation noted no loss of Meary’s talo-first metatarsal angle when comparing initial postoperative radiographic to their final follow up. Additional complications in our cohort included the following: removal of painful hardware (1, 2.22%), sural neuritis (2, 4.44%), superficial cellulitis (1, 4.44%), and delayed lateral wound healing(1, 2.22%).Conclusion:Preliminary data shows that early protected weight bearing after flatfoot reconstruction and augmentation of the spring ligament with the InternalBrace device is safe and demonstrates few complications and no early loss of correction.

The Influence of Preoperative Deformity Severity in Postoperative Patient Reported Outcomes in Adult Acquired Flatfoot

Category:Ankle; Hindfoot; OtherIntroduction/Purpose:Adult acquired flatfoot deformity (AAFD) is a complex deformity. Previous work has demonstrated correlation between postoperative foot alignment and patient-reported outcomes. While this work has provided essential targets for surgeons performing flatfoot reconstruction, there is an absence of data that would enable surgeons to predict which patients are likely to have greater or less improvement after surgery based on their preoperative deformity. Conventional radiographs alone may not provide enough detail to isolate individual elements of the deformity. Weightbearing CT (WBCT) allows for far more precise analysis in this regard. We hypothesized that there would be a set of parameters defining preoperative alignment on WBCT that would predict which patients are at risk for a lower magnitude of postoperative improvement in patient-reported outcomes (PROs).Methods:In this retrospective IRB-approved study, patients that underwent surgical flatfoot reconstruction after having a preoperative standing WBCT were identified. Preoperative WBCT images were evaluated by two independent/blinded observers. Multiple parameters related to preoperative alignment and AAFD severity were measured in the sagittal, coronal and transverse planes. Parameters measured included talus-first metatarsal angle; distances between the floor and the navicular, medial cuneiform and cuboid; subtalar joint horizontal angle; superior talar - inferior talar angle; subtalar joint subluxation; talonavicular uncoverage angle; hindfoot moment arm (HMA); and foot and ankle offset (FAO). Prospectively collected data regarding preoperative and postoperative PROs was evaluated. Six PROs components were assessed: physical function; pain interference, pain intensity, global mental health, global physical health and depression. Multivariate regression analysis and a partition prediction model were used to assess the correlation between preoperative alignment and improvement in PROs. P-values of less than 0.05 were considered significant.Results:A total of 51 patients with a preoperative WBCT and postoperative PROs scores were identified and included. Demographic data is shown in Table 1. Multivariate regression analysis demonstrated that preoperative alignment significantly correlated with improvement in three out six components of PROs: pain interference, pain intensity and global mental health. The strongest predictor of improvement in PROMIS physical function t-score was medial cuneiform to floor distance, for pain interference t-score: cuboid to floor distance, for pain intensity: subtalar joint subluxation, for depression t-score: superior talar - inferior talar angle, and for global physical and mental health t-scores: sagittal talus-first metatarsal angle.Conclusion:Our analysis yielded readily identifiable cutoffs for WBCT measurements, where values above or below were correlated with significant differences in the magnitude of PRO score change. Interestingly, measures of sagittal plane collapse and hindfoot valgus were the most predictive of score changes. This data provides useful information for surgeons counseling patients prior to flatfoot reconstruction. Future work using this data to develop prediction models for postoperative outcomes would be valuable, as would studies using WBCT to evaluate the relationship between postoperative corrected alignment and PROs.Complete results are shown in the attached Table.

Clinical Significance of Measurements in Adult Acquired Flatfoot Deformity using Weight Bearing CT: A Matched Case-Control Study

Category:Hindfoot; OtherIntroduction/Purpose:Adult Acquired Flatfoot Deformity (AAFD) results in progressive foot collapse through peritalar subluxation. Numerous radiographic and Weight Bearing CT (WBCT) measurements have been described in the literature aiming to gauge the severity of the multiple components of the deformity. However, the real diagnostic power of each measurement is currently unknown. Moreover, novel measurements have recently been described such as 3D biometrics and multidimensional measurements. The objective of this case-control study was to individually assess the diagnostic accuracy of known 2D and 3D WBCT measurements and to compare it with a novel multidimensional measurement. We hypothesized that the latter would demonstrate superior diagnostic power than isolated 2D and 3D measurements.Methods:Retrospective case-control study, including 19 AAFD feet and 19 controls that were matched for age, gender and BMI (9 male, 10 female, mean age 54.4 years in both groups). All patients had standing WBCT imaging as baseline assessment of their foot pathology. 2D measurements assessed included: axial and sagittal talus-first metatarsal angles (TM1A), talonavicular coverage angle (TNCA), forefoot arch angle (FFAA) and middle facet incongruence angle (MF°) and uncoverage percentage (MF%). The 3D Foot and Ankle Offset (FAO) was calculated using semi-automatic software. A novel multiplanar biometric measurement (AAFD- MD) was calculated using a multidimensional mathematical algorithm that pooled multiplanar 2D measurements. Intra and interobserver reliabilities were assessed. Comparisons between variables were done using Student-t test or Wilcoxon rank-sum test. Receiver Operating Characteristic (ROC) curves were calculated to determine diagnostic accuracy, sensitivity and specificity of each measurement.Results:AUC for ROC curves were 1. for MF%, 0.96 for FAO, 0.94 for MF° and 0.92 for AAFD-MD. For MF%, a threshold value equal of greater than 28.1% was found to be diagnostic of AAFD with a sensitivity of 100% and specificity of 100%. FFAA were decreased in AAFD: 6.3° versus 15.2° in controls (p<0.001). Axial and sagittal TM1A were respectively 17.6° and 20.8° in AAFD, while in controls: 7.5° (p<0.001) and 6.3° (p< 0.001). The TNCA was increased in AAFD: 27.9° versus 15.6° in controls (p<0.001). In AAFD, MF° and MF% were respectively 13° and 49.4% compared with 5.3° and 10.6% in controls (p<0.001 for both). The FAO was 7.5% in AAFD and 1.1% in controls (p<0.001).Conclusion:The observed results did not confirm our hypothesis. The multidimensional measurement was not as accurate a diagnostic tool as Middle Facet uncoverage percentage which expresses the amount of subluxation of the MF. In that respect, this could mean that congruency of the middle facet could be the last frontier between asymptomatic Pes Planovalgus and symptomatic AAFD, leading to progressive foot collapse, secondarily affecting the FAO. These results also give insight into the meaning of the FAO, which appears here to be a more general assessment of the Foot and Ankle Complex alignment, rather than a marker for a specific pathology.

Outcomes after Tibiocalcaneonavicular Ligament Reconstruction in Stage IIB and Stage IV Adult Acquired Flatfoot Deformity

Category:Hindfoot; Ankle; Midfoot/ForefootIntroduction/Purpose:The tibiocalcaneonavicular ligament (TCNL) is formed from the confluence of the superficial deltoid ligament and the superomedial spring ligament. In advanced flexible adult acquired flatfoot deformity (AAFD), progressive strain on the TCNL can lead to spring ligament tears, deltoid insufficiency, and eventual medial peritalar instability. Historically, medial peritalar instability was corrected using calcaneal osteotomy in conjunction with isolated spring or deltoid reconstruction. A recent study (Brodell et al.) demonstrated the efficacy of TCNL reconstruction in patients with medial peritalar instability. The purpose of this study is to add to this literature using patient-reported and radiographic outcomes in patients undergoing TCNL reconstruction. Patient-reported outcomes were collected using Patient Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF) and Pain Interference (PI) surveys.Methods:Sixteen patients (mean age 50.25 years; 11 female, 5 male) who underwent TCNL reconstruction were prospectively identified. TCNL reconstruction was indicated for stage IIB patients (n=13) with large spring ligament tears (>1.5cm on MRI or intraoperatively) or if osseous correction did not provide adequate talonavicular joint correction. TCNL reconstruction was indicated in stage IV patients (n=3) if deltoid reconstruction required additional medial stabilization. No patients underwent lateral column lengthening osteotomies. PROMIS scores were obtained at baseline and at minimum 12-months follow-up (average 16 months). Surgical success was determined using minimum clinically important differences (MCID), defined as improvement greater than one-half the standard deviation of each pre-operative PROMIS domain (PF: +2.9 and PI: -2.5). Pre- and post-operative radiographic parameters were measured: talonavicular uncoverage angle, talonavicular uncoverage percentage, AP talo-first metatarsal angle, Meary’s angle, and medial cuneiform height (MCH). Correlation coefficients determined the relationship between radiographic parameters and PROMIS scores.Results:PROMIS PF scores improved significantly from 38.1+-5.8 to 44.1+-7.1 (p=0.0087). PROMIS PI scores improved significantly from 62.9+-5.1 to 52.3+-8.9 (p=0.0025). Seventy-nine and 77 percent of patients had successful surgeries, as defined by MCIDs in the PROMIS PF and PI domains, respectively. Talonavicular uncoverage percentage and Meary’s angle improved significantly from 34.4+-13.4 to 26.3+-9.9 percent (p=0.0360) and 19.2+-8.8 to 15.3+-6.2 degrees (p=0.0089), respectively. Talonavicular uncoverage angle improved from 29.3+-9.6 to 23.3+-8.0 degrees (p=0.0562), AP talo-first metatarsal angle improved from 15.2+-10.2 to 10.4+-9.0 degrees (p=0.0555), and MCH improved from 13.5+-6.2 to 15.9+-4.8 millimeters (p=0.1374). Post- operative MCH correlated significantly with post-operative PROMIS PF scores (r=0.5941; p=0.0152). Change in AP talo-first metatarsal angle correlated significantly with change in PROMIS PI scores (r=0.5682; p=0.0427). No other correlations were significant.Conclusion:Patients with stage IIB and stage IV AAFD who undergo TCNL reconstructions have excellent patient-reported and radiographic outcomes. Reconstruction of the medial longitudinal arch, as measured by post-operative MCH, is associated with higher post-operative functionality. Surgical correction of midfoot abduction, as measured by change in the AP talo-first metatarsal angle after surgery, is associated with improvements in pain. In patients with medial peritalar instability, TCNL reconstruction can be a valuable technique to correct the sagittal arch, prevent excessive midfoot abduction, and improve pain and functionality.

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

Category:Hindfoot; Midfoot/ForefootIntroduction/Purpose:Our aims were: (i) to determine whether subtalar arthroereisis (STA) as adjunct procedure improved radiographic correction of stage IIb adult acquired flexible flatfoot deformity (AAFD); (ii) to assess the STA-related complication rate.Methods:A retrospective analysis of 22 feet (21 patients) diagnosed with stage IIb AAFD treated by medialising 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 two observers and repeated twice by one. Inter and intraobserver reliability was assessed. The association of demographic (gender, side, age, BMI) and surgical variables (Cotton, STA) with radiographic change was tested with univariate analysis followed by a multivariable regression model.Results:Excellent inter and intraobserver reliability was demonstrated for all measurements (ICC range, 0.75-0.99). Multivariable regression showed that STA was the only predictor of change in talo-navicular coverage angle (TNCA) (R2=0.31; p=0.03) and in calcaneo-fifth metatarsal angle (CFMA) (R2=0.40; p=0.02) on dorsoplantar view. STA was associated to a greater change in TNCA by 10.1 degrees and in CFMA by 5 degrees. 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%.