Translated article] Cadaveric biomechanical study of the calcaneonavicular ligament in midfoot medial column collapse comparing two surgical techniques.

Background/Objectives: Bilateral Achilles tendon ruptures are exceptionally rare, accounting for <1% of Achilles injuries; chronic presentations are frequently linked to diagnostic delay in the acute phase. The aim of this paper is to describe a modified, single-stage bilateral reconstruction of neglected Achilles tendon ruptures using Flexor Digitorum Longus (FDL) transfer and turndown flaps. This study evaluates 12-month functional and radiological outcomes while comparing this surgical strategy with current literature. Methods: A 58-year-old man with rheumatoid arthritis on long-term corticosteroids presented 4 months after asynchronous bilateral Achilles ruptures with progressive weakness and gait limitation. Clinical examination and MRI confirmed chronic discontinuity with retracted stumps and interstump gaps of ~6.5-7.0 cm. Intervention: After pre-operative tapering of corticosteroids, a single-stage bilateral reconstruction was performed. Surgical intervention involved simultaneous bilateral reconstruction using flexor digitorum longus (FDL) transfer for one tendon and a combination of FDL and flexor hallucis longus (FHL) transfers for the other, with bilateral turndown flap augmentation. Decisions regarding tendon transfers were based on intraoperative findings, with the FDL selected for its larger caliber when the FHL was deemed insufficient. Results: Recovery was uneventful. At 6 months, the patient resumed full-time work and could perform repeated tiptoe rises. The AOFAS ankle-hindfoot score improved from 46 pre-operatively to 85. At 12 months, MRI demonstrated bilateral tendon continuity without re-rupture, with hypertrophy at the reconstructed stumps. Conclusions: In chronic, large-gap bilateral Achilles ruptures with systemic risk factors, single-stage reconstruction using FDL (with or without FHL) plus turndown augmentation is feasible and yields favorable functional recovery. Careful tensioning, secure calcaneal fixation, steroid optimization, and structured rehabilitation appear pivotal to outcomes. This case supports the applicability of this strategy in complex bilateral presentations.

Category: Midfoot/Forefoot Introduction/Purpose: Residual forefoot supination present after correcting the hindfoot in Stage IIb adult acquired flatfoot deformity (AAFD) can be addressed with a dorsal opening wedge medial cuneiform (Cotton) osteotomy. The amount of correction is generally judged clinically and there currently are no preoperative guides that can predict the size of graft needed. The aim of this study was to evaluate the relationship between the Cotton osteotomy graft size and other accessory flatfoot reconstructive procedures, and the amount of correction of longitudinal arch collapse. We hypothesized that correction of longitudinal arch collapse, as measured by the cuneiform articular angle (CAA), would primarily be influenced by the Cotton osteotomy performed. More specifically, we hypothesized that the size of the graft would have the largest effect on the CAA. Methods: Seventy-nine feet in 74 patients undergoing Cotton osteotomy as part of flatfoot reconstruction were reviewed retrospectively. Preoperative and minimum 40-week postoperative lateral weightbearing foot radiographs were compared to assess correction of longitudinal arch collapse as measured by 13 radiographic parameters, with particular emphasis on the CAA. Additional demographic and intraoperative variables analyzed for association with radiographic change included age, gender, body mass index (BMI), amounts and graft types of Cotton osteotomy and lateral column lengthening (LCL), and amount of medializing calcaneal osteotomy (MCO). Other concomitant procedures at the time of surgery, namely Achilles lengthening, flexor digitorum longus (FDL) transfer, spring ligament reconstruction, gastrocnemius recession, and excision of accessory navicular were also recorded. Ultimately, a multivariable linear regression model was developed to estimate the effect of Cotton osteotomy on change in the CAA, adjusting for patient and clinical variables. Results: Cotton osteotomy graft size was significantly associated with changes in the CAA (P &lt; .001), calcaneal pitch (P = .03), lateral talo-navicular Cobb angle (P = .03), and lateral naviculo-medial cuneiform Cobb angle (P = .03). Multivariable linear regression models included age at surgery, gender, BMI, and the use of all concomitant procedures (LCL, Achilles lengthening, FDL transfer, gastrocnemius recession, and excision of accessory navicular) except for spring ligament reconstruction, since this was not associated with any of the four radiographic measurements. Cotton graft size was the only factor found to significantly predict a change in the CAA in the final linear regression model (P &lt; .001, R2 = .27), with each millimeter of Cotton corresponding to a 2.1-degree decrease of the CAA (figure 1). Conclusion: Correction of longitudinal arch collapse, as measured by the CAA, was primarily influenced by graft size of the Cotton osteotomy in a linear fashion. The results also demonstrate that the procedure has a more distal effect in correction of longitudinal arch collapse and is of particular importance when the apex of deformity is at the medial cuneiform. Because the relationship between the Cotton osteotomy graft size and the CAA can be modeled linearly, we believe that preoperative measurement of the CAA can be a useful guide in helping surgeons to titrate the proper amount of longitudinal arch collapse correction intraoperatively.

The purpose of this prospective study was to evaluate the response of the flexor digitorum longus (FDL) and posterior tibial (PT) muscles to FDL tendon transfer and medial displacement calcaneal osteotomy for stage II posterior tibial tendon dysfunction (PTTD). Twelve patients were divided into two groups, depending on whether the PT tendon was excised (Excised Tendon Group) or left intact (Intact Tendon Group). The muscle volumes of the FDL and PT muscles in both legs were measured and compared, using cross-sectional area (CSA) analysis of preoperative and postoperative MRI. Preoperatively, there was an average 11% reduction in the PT muscle volume and a 17% increase in the FDL muscle volume from the normal contralateral side in both groups. One year after surgery (average 13.4 months) in both groups, the FDL muscle volume had increased by an average of 27% and the PT muscle volume had decreased by 23% compared to the contralateral normal side. The FDL volume increased by 44% in the Excised Tendon Group compared to 11% in the Intact Tendon Group. The PT muscle volumes were not assessed in the Excised Tendon Group because all PT muscle had been replaced by fatty infiltration. The PT volumes in the Intact Tendon Group decreased further from a 6% reduction preoperatively to a 23% reduction postoperatively compared to the normal contralateral side. The American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot scores increased from 50 preoperatively to 88 at 1 year after surgery. There was no difference in the scores between the Excised Tendon (47 to 87) and Intact Tendon (53 to 89) groups. We concluded that the FDL muscle hypertrophies in response to a failing PT muscle. This hypertrophy continues after FDL transfer and medial displacement calcaneal osteotomy. With excision of the PT tendon, the FDL undergoes greater hypertrophy than if the tendon is left attached. The PT muscle continues to atrophy and undergoes complete fatty replacement if the tendon is excised. Transfer of the FDL and medial displacement calcaneal osteotomy produce a satisfactory improvement in hindfoot function; the outcome was the same whether the PT tendon was sacrificed or left intact.

Concomitant tears of the peroneus longus and brevis tendons are rare injuries, with literature limited to case reports and small patient series. Only 1 recent study directly compared the results of single-stage lateral deep flexor transfer, and no previous series objectively evaluated power and balance following transfer. The purpose of this study was to evaluate clinical outcomes, patient satisfaction, and objective power and balance data following single-stage flexor hallucis longus (FHL) and flexor digitorum longus (FDL) tendon transfers for treatment of concomitant peroneus longus and brevis tears. Over an 8-year period (2005-2012), 9 patients underwent lateral transfer of the FHL or FDL tendon for treatment of concomitant peroneus longus and brevis tears. All but 1 patient underwent additional procedures to address hindfoot malalignment or other contributing deformity at the time of surgery. Mean age was 56.9 years, and average body mass index was 27.9. Lateral transfer of the FHL was performed in 5 patients, and FDL transfer performed in 4 with mean follow-up 35.7 months (range: 11-94). Eight of 9 patients completed SF-12 and Foot Function Index (FFI) scores, and 7 returned for range of motion (ROM) and manual strength testing of the involved and normal extremities. These 7 patients also completed force plate balance tests, in addition to peak force and power testing on a PrimusRS machine with a certified physical therapist. All patients were satisfied with the results of the procedure. Mean SF-12 physical and mental scores were 32 and 55, respectively; mean FFI total score was 56.7. No postoperative infections were noted. Two patients continued to utilize orthotics or braces, and 2 patients reported occasional pain with weightbearing activity. Three patients noted mild paresthesias in the distribution of the sural nerve and 2 demonstrated tibial neuritis. All patients demonstrated 4/5 eversion strength in the involved extremity. Average loss of inversion and eversion ROM were 24.7% and 27.2% of normal, respectively. Mean postoperative eversion peak force and power were decreased greater than 55% relative to the normal extremity. Patients demonstrated nearly 50% increases in both center-of-pressure tracing length and velocity during balance testing. There were no statistically significant differences between the FHL and FDL transfer groups with regards to clinical examination or objective power and balance tests. The FHL and FDL tendons were both successful options for lateral transfer in cases of concomitant peroneus longus and brevis tears. Objective measurements of strength and balance demonstrated significant deficits in the operative extremity, even years following the procedure. These differences, however, did not appear to alter or inhibit patient activity levels or high satisfaction rates with the procedure. Although anatomic studies have demonstrated benefits of FHL transfer over the FDL tendon, further studies with increased patient numbers are needed to determine if these differences are clinically significant. Level IV, retrospective case series.

Posterior Tibial Tendon Allograft Reconstruction for Stage II Adult Acquired Flatfoot: A Case Series

Background: Acquired flexible flatfoot encompasses a wide spectrum of disease, and there is no validated treatment protocol. We hypothesized that a medializing calcaneal osteotomy with a flexor digitorum longus transfer is adequate to correct a less severe acquired flexible flatfoot but not a more severe flatfoot. We also hypothesized that use of an additional procedure would further correct the flatfoot. Methods: The study included seven pairs of cadaver specimens, with one side randomly selected for the creation of a mild flatfoot deformity and the other, for the creation of a severe flatfoot deformity. Cyclic axial load was applied to the intact foot, to the flatfoot, after correction with a medializing calcaneal osteotomy and a flexor digitorum longus transfer, and after the addition of a subtalar arthroereisis. Radiographic and pedobarographic data were obtained at each stage. A repeated-measures analysis of variance with post hoc analysis was used to compare all parameters in the intact foot with those in the flatfoot and corrected specimens. A Student t test was used to compare flatfoot severity between the mild and severe models. Results: Compared with the intact foot, the mild and severe flatfoot models showed a significant change in the talar-first metatarsal angle (p = 0.01 and 0.03, respectively), talonavicular angle (p = 0.04 and 0.04), and medial cuneiform height (p = 0.03 and 0.05). The mild and severe models were significantly different from each other with regard to the talar-first metatarsal angle (p = 0.003) and talonavicular angle (p = 0.002). After the osteotomy and tendon transfer in the mild-flatfoot model, the talar-first metatarsal angle and talonavicular angle were not significantly different from those in the intact state. In the severe-flatfoot model, the talar-first metatarsal angle, talonavicular angle, and medial cuneiform height remained significantly undercorrected after the osteotomy and tendon transfer. After the arthroereisis, the talonavicular angle and medial cuneiform height were not significantly different from the values for the intact foot. Conclusions: In a cadaver model, the effectiveness of different procedures on radiographic and pedobarographic parameters varies with the severity of an acquired flatfoot deformity. Clinical Relevance: This study suggests that less severe acquired flexible flatfoot might be appropriately treated with a combined medializing calcaneal osteotomy and flexor digitorum longus transfer and that severe flatfoot might require an additional procedure for adequate correction.

The function of the posterior talofibular ligament was studied using an apparatus which subjected the ankle joint to a measured torque and allowed the simultaneous recording of rotatory movements in two planes. Thirty osteoligamentous preparations of ankle joints were examined, half in the sagittal and horizontal planes and the remainder in the sagittal and frontal planes. Successive section of the lateral collateral ligaments was performed, including, in particular, selective division of the short and long fibres of the posterior talofibular ligament. The function of this ligament was investigated in combination with the other two collateral lateral ligaments, with the calcaneofibular ligament alone, and finally as the only remaining intact ligament. The posterior talofibular ligament plays only a supplementary role in ankle stability when the lateral ligament complex is intact. After rupture of the anterior talofibular and the calcaneofibular ligaments, however, the short fibres of the posterior ligament restrict internal and external rotation, talar tilt, and dorsiflexion, while its long fibres inhibit only external rotation, talar tilt, and dorsiflexion. As the posterior talofibular ligament has no independent stabilizing function in the intact ankle joint, an isolated rupture of this ligament is unlikely.

Twenty-three patients with stage II posterior tibial tendon dysfunction who had failed non-surgical therapy were treated with flexor digitorum longus transfer and calcaneal osteotomy. At latest follow-up averaging 35 +/- 7 months (range, 24 to 51 months), 22 patients (96%) were subjectively "better" or "much better." No patient had difficulty with shoe wear; however, four patients (17%) required routine orthotic use consisting of a molded shoe insert. AOFAS scores were available on 21 patients and improved from a preoperative mean of 50 +/- 14 (range, 27 to 85) to a postoperative mean of 89 +/- 10 (range, 70 to 100). Our experience, at an intermediate date follow-up is that calcaneal osteotomy and flexor digitorum longus transfer is a safe and effective form of treatment for stage II posterior tibial tendon dysfunction.

Category: Hindfoot, Sports Introduction/Purpose: Medial displacement calcaneal osteotomy with flexor digitorum longus transfer is considered the gold standard in treatment of adult flatfoot associated with posterior tibial tendon dysfunction (stage II in Myerson classification). The aim of this study was to estimate if patients underwent medial displacement calcaneal osteotomy with flexor digitorum longus transfer can participate to sport activities. Methods: 48 patients (21 men, 43,75%; 27 women, 56,25%) with a mean age at time of surgery of 42,3 years (range 19-74 years) were evaluated with a medium follow-up of 30 months (range, 27-34 months). All patients were evaluated clinically and by imaging before and after surgery. The clinical evaluation included for each patient the self-filling of Sports Athlete Foot and Ankle Score (SAFAS). and Pre- and postoperative sporting activities were recorded. The imaging evaluation included a pre-operative foot and ankle MRI and weight-bearing radiographs (antero-posterior, lateral and Saltzman 20° views) of the foot and ankle before surgery and at final follow-up. Moreover, each patients’ pre- and post-operative sport activities were recorded. Results: Preoperatively, 29 of 48 (60,4%) patients were engaged in athletic activities, participating in an average of 1.4 hours/week (range, 0-6 hours/week); postoperatively, 40/48 (83.3%) participated in sport and recreational activities for an average of 3.5 hours/week (range, 0-15 hours/week). Meary’s angle improved significantly from 11.3±6.3 degrees preoperatively to 7.2±5.5 degrees at final-follow-up (p&lt;0.01); calcaneal pitch improved significantly from 16.1±4.3 degrees to 19.4±4.8 degrees (p&lt;0.01). At final follow-up, patients demonstrated good SAFAS scores in symptom tolerance (85.90%), pain tolerance (88.30%), daily living performance (96.2%) and sports performance (86.45%). Conclusion: Most of patients returned or resumed to participate to sport activities after medial displacement calcaneal osteotomy and flexor digitorum longus transfer for the treatment of adult flatfoot associated with posterior tibial tendon dysfunction and the increase of the average number of activities for patient and of the mid time spent was observed.

ACL Research Retreat V

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

Progressive Collapsing Foot Deformity (PCFD), previously termed Adult Acquired Flatfoot Deformity (AAFD), is a progressive condition characterized by failure of medial soft tissue structures leading to painful biomechanical dysfunction. Traditional reconstructions often rely on nonanatomic osteotomies, such as lateral column lengthening, which carry notable risks. This study evaluates a novel soft tissue reconstruction of the spring-deltoid ligament complex combined with medial column osteotomies for stage II PCFD. Methods: A retrospective case series was performed on 9 feet in 8 patients (mean age 44.7 years) treated between September 2021 and December 2024. The surgical technique included spring ligament InternalBrace™ augmentation with Flexor Digitorum Longus (FDL) transfer, Cotton osteotomy with titanium wedge and minimally invasive Medial Calcaneal Osteotomy (MICO). Pre- and postoperative radiographs were analyzed for Meary’s angle, talocalcaneal angle, calcaneal inclination angle, calcaneocuboid angle and intermetatarsal angle. Functional outcomes were assessed using FAOS and AOFAS hindfoot scores. Paired t-tests determined statistical significance (p &lt; 0.05). Results: All radiographic parameters demonstrated significant improvement: Meary’s angle (14.56° → 2.11°), talocalcaneal angle (28.11° → 18.44°), calcaneal inclination (11.67° → 15.89°), calcaneocuboid angle (21.11° → 12.11°) and intermetatarsal angle (11.11° → 6.67°) (all p &lt; 0.05). Functional outcomes also improved, with mean FAOS of 79.1 ± 10.5 and mean AOFAS of 84.3 ± 3.8 at an average of 21 month follow-up. No patients required adjunctive lateral column lengthening and no construct failures or major complications were observed. Conclusion: Spring-deltoid ligament reconstruction with InternalBrace™ augmentation, combined with MICO and Cotton osteotomy, achieved significant radiographic and functional correction in stage II PCFD without the need for nonanatomic lateral column lengthening. This technique may provide a safer, anatomic alternative to traditional reconstructions, offering reliable restoration of medial column stability and improved patient-reported outcomes. Level of Evidence: IV (Retrospective case series).

Load response of the medial longitudinal arch in patients with flatfoot deformity: in vivo 3D study

Position of the anterior cruciate ligament (ACL) represents one of the anatomical factors which can lead to the rupture of the ligament. The aim of this study was to overview and compare gender and age differences of the position of the ACL and its relation with the medial aspect of the lateral femoral condyle. The measurements were performed on the fifty cadaver knees (32 male and 18 female) aged between 15 - 53 years with intact ACL. We were measuring the angle of the ACL in sagittal and frontal plane and the angle of the medial aspect of the lateral condyle in frontal and horizontal plane. Measurements of the ACL in sagittal plane and measurements of the angle of the medial aspect of the lateral femoral condyle in horizontal plane showed statistically significant variations with the age (p < 0.05 and p < 0.01, respectively). The angle of the medial aspect of the lateral femoral condyle in frontal plane was statistically significant higher than the same measured angle in the horizontal plane ( p < 0.01). ACL fomis narrower angle with medial aspect of the lateral femoral condyle in extension of lower leg than in flexion as a result of smaller angle of the medial aspect of the lateral femoral condyle in frontal compared to horizontal plane.

Flexor Digitorum Longus transfer and medial displacement calcaneal osteotomy for posterior tibial tendon dysfunction: A clinical and radiographical analysis