Search

Ankle joint line orientation (AJLO) is influenced by the subtalar foot and frontal leg alignment. However, the influence of axial leg alignment on AJLO remains unclear. The study aimed to analyze the influence of frontal, axial leg alignment on AJLO in healthy subjects.Thirty healthy subjects (60 legs) without prior surgery underwent standing biplanar long leg radiograph (LLR) between 2016 and 2020. AJLO was measured in standing long-leg radiographs relative to the ground. Meary's angle and calcaneal pitch were measured. Hip-knee-ankle angle (HKA), femoral antetorsion, and tibial torsion were assessed with SterEOS software (EOS Imaging, Paris, France). LLR was acquired with the feet directing straight anteriorly, which corresponds to a neutral foot progression angle (FPA). The influence of subtalar, frontal, and axial alignment on AJLO was analyzed in a multiple regression model.An increase in knee valgus increased relative valgus AJLO by 0.5° (95% CI: 0.2° to 0.7°) per 1° (P 0.001). A decrease in femoral antetorsion increased relative valgus AJLO by 0.2° (95% CI: 0.1° to 0.2°) per 1° (P 0.001), whereas Meary's angle and calcaneal pitch did not influence AJLO.A link between frontal, axial leg alignment, and AJLO could be demonstrated, indicating that a valgus leg alignment and relative femoral retrotorsion are associated with an increase of valgus AJLO in healthy subjects when placing their feet in a neutral position. Alteration of the frontal, or rotational profile after realignment surgery or by implant positioning might influence the AJLO, when the FPA is kept constant.

Background: In cases of tibialis anterior tendon (TAT) ruptures associated with significant tendon defect, an interposition graft is often needed for reconstruction. Both auto- and allograft reconstructions have been described in the literature. Our hypothesis was that both graft types would have a good integrity and provide comparable outcomes. Methods: Patients who underwent TAT reconstruction using either an auto- or allograft were identified. Patient-reported outcomes (PROs) were collected using the 12-Item Short Form Health Survey (SF-12) questionnaire, the American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score, the Foot Function Index (FFI), and the Karlsson-Peterson score. Functional outcome was assessed by isokinetic strength measurement. Outcomes were further assessed with magnetic resonance imaging (MRI) evaluation of graft integrity. All measurements were also performed for the contralateral foot. Results: Twenty-one patients with an average follow-up of 82 months (20-262 months), comprising 12 allograft and 9 autograft TAT reconstructions, were recruited. There were no significant differences in patient-reported outcomes between allograft reconstructions and autografts: SF-12 (30.7 vs 31.1, P = .77); AOFAS (83 vs 91.2, P = .19); FFI (20.7% vs 9.5%, P = .22); and Karlsson-Peterson (78.9 vs 87.1, P = .23). All grafts (100%) were intact on MRI with a well-preserved integrity and no signs of new rupture. There were no major differences in range of motion and functional outcomes as measured by strength testing between the operative and nonoperative side. Conclusion: Reconstructions of TAT achieved good PROs, as well as functional and imaging results with a preserved graft integrity in all cases. There were no substantial differences between allograft and autograft reconstructions. Level of Evidence: Level IV, retrospective case series.

To optimize the biomechanical outcomes in lateral ankle ligament reconstruction, avoid stiffness or residual laxity, aiming for an isometric reconstruction of the anterior lateral talofibular ligament (ATFL) and the calcaneofibular ligament (CFL) is mandatory. However, the localization of the optimal ligament insertion remains challenging to assess intraoperatively.Three-dimensional (3D) surface models from 10 healthy ankles were generated. 30 insertion points of the CFL were defined on the lateral side of the calcaneus each 10% of its total length in the dorsal-to-ventral and proximal-to-distal plane. 6 insertion points were defined at the ventral ridge of fibula from the malleolar tip and 5 insertions were defined along the lateral talar process. The ligament length variation of ATFL and CFL was assessed after a simulation of the flexion/extension around a simulated tibiotalar axis and inversion/eversion around a simulated subtalar axis in 36 different positions.The isometric point of CFL on the calcaneus is located at about 60% along the dorsal-to-ventral and between 60% and 70% along the proximal-to-distal plane. From maximal extension to flexion, these points present respectively a length variation of - 0.8 to - 1.1 mm (p = 0.46) and - 1.1 to - 0.8 mm (p = 0.56). A fibular insertion at 5 mm proximal to the malleolar tip present a length variation ranging from - 0.1-1 mm (p 0.001) for ATFL and from - 0.7-0.5 mm (p 0.001) for CFL. A talar insertion point of the ATFL located 5 mm proximal to the subtalar joint present the lowest variation, ranging from - 1.1-0.7 mm (p 0.001), however an insertion at 20- or 25-mm present isometry (+0.1 to +0.9 mm p = 0.1, and +0.4 to +0.4 mm p = 1 respectively) if the fibular insertion is located at 5 mm proximal to the malleolar tip.This study provides anatomical references which are reproducible in daily practice. These insertion points allow to achieve a stable reconstruction while maintaining a tension-free mobilization of the ankle.

Restriction of greater toe dorsiflexion without degeneration of the first metatarsophalangeal joint is defined as hallux limitus. We assume that in hallux limitus the limitation of greater toe dorsiflexion takes place in the terminal stance phase because of massive tightening of the calf and plantar structures. The current study investigated the role of a tight plantar fascial structure in impairing dorsiflexion of the greater toe. For the purpose of the study, 7 lower limbs from Thiel-fixated human cadavers were evaluated. To simulate double-limb standing stance, the tibia and fibula were mounted on a materials testing machine and constantly loaded with 350N. Additionally, the tendons of the specimens were loaded using a custom-made system. The plantar fascia was fixed to a clamp and tensioned using a threaded bar. Four different tensile forces were then applied to the plantar fascia (approximately 100, 200, 300, and 350 N) and the extension of the first toe was measured. The results show a significant positive correlation between the decrease in extension of the hallux and the tension applied to the plantar fascia reaching a maximum mean decrease of 4.2° (117% compared with the untightened situation) for an applied tension of 364N.

Background Biomechanical studies have shown a higher compressive force and higher torsional stiffness for fixation with three screws compared to two screws. However, clinical data to compare these fixation techniques is still lacking. Methods A retrospective analysis of 113 patients was performed, who underwent isolated subtalar fusion between January 2006 and April 2018. Results Revision arthrodesis was required in 8% (n = 6/36) for 3-screw-fixation and 38% (n = 35/77) for 2-screw-fixation. For 3-screw-fixation, non-union, was observed in 14% (n = 5/36) compared to 35% (n = 27/77) in 2-screw fixation. Non-union (p = .025) and revision arthrodesis (p = .034) were significantly more frequent in patients with 2 screws. A body mass index ≥30 kg/m2 (p = .04, OR = 2.6,95%CI:1.1–6.3), prior ankle-fusion (p = .017,OR = 4.4,95%CI:1.3–14.5) and diabetes mellitus (p = .04,OR = 4.9,95%CI:1.1–17.8) were associated with a higher rate of revision arthrodesis. Conclusions Our findings suggest that successful subtalar fusion is more reliably achieved with use of three screws. However, future prospective studies will be necessary to further specify this recommendation.

Purpose Posttraumatic fibular malunion alters ankle joint biomechanics and may lead to pain, stiffness, and premature osteoarthritis. The accurate restoration is key for success of reconstructive surgeries. The aim of this study was to analyze the accuracy of a novel three-dimensional (3D) registration algorithm using different segments of the contralateral anatomy to restore the distal fibula. Methods Triangular 3D surface models were reconstructed from computed tomographic data of 96 paired lower legs. Four segments were defined: 25% tibia, 50% tibia, 75% fibula, and 75% fibula and tibia. A surface registration algorithm was used to superimpose the mirrored contralateral model on the original model. The accuracy of distal fibula restoration was measured. Results The median rotation error, 3D distance (Euclidean distance), and 3D angle (Euler’s angle) using the distal 25% tibia segment for the registration were 0.8° (− 1.7–4.8), 2.1 mm (1.4–2.9), and 2.9° (1.9–5.4), respectively. The restoration showed the highest errors using the 75% fibula segment (rotation error 3.2° (0.1–8.3); Euclidean distance 4.2 mm (3.1–5.8); Euler’s angle 5.8° (3.4–9.2)). The translation error did not differ significantly between segments. Conclusion 3D registration of the contralateral tibia and fibula reliably approximated the premorbid anatomy of the distal fibula. Registration of the 25% distal tibia, including distinct anatomical landmarks of the fibular notch and malleolar colliculi, restored the anatomy with increasing accuracy, minimizing both rotational and translational errors. This new method of evaluating malreductions could reduce morbidity in patients with ankle fractures. Level of evidence IV

Background: Peroneus brevis tendon tears are associated with chronic ankle pain and instability following sprain injuries. The aim of this study is to elucidate the biomechanical changes induced by a peroneus brevis split and surgical treatment by tubularizing suture or partial resection. Methods: Nine human lower leg specimens were biomechanically tested. Preexisting tendon pathology was ruled out by magnetic resonance imaging and histology. Specimens were subjected to sequential testing of 4 conditions of the peroneus brevis tendon: (1) native, (2) longitudinal lesion, (3) tubularizing suture, and (4) 50% resection. The outcome parameters were the tendon stiffness (N/mm) and the length variation of the split portion at 5 N load. Results: The median specimen age at death was 55.8 years (range 50-64 years). The longitudinal tendon split led to an elongation by 1.21 ± 1.15 mm, which was significantly reduced by tubularizing suture to 0.24 ± 0.97 mm ( P = .021). Furthermore, 50% resection of the tendon elongated it by a mean 2.45 ± 1.9 mm ( P = .01) and significantly reduced its stiffness compared to the intact condition (4.7 ± 1.17 N/mm, P = .024) and sutured condition (4.76 ± 1.04 N/mm, P = .011). Conclusion: Longitudinal split and 50% resection of the peroneus brevis tendon led to elongation and loss of tendon stiffness. These properties were improved by tubularizing suture. The significance of these changes in the clinical setting needs further investigation. Clinical Relevance: Tubularizing suture of a peroneus brevis split can restore biomechanical properties to almost native condition, potentially aiding ankle stability in symptomatic cases. A split lesion and partial resection of the tendon showed reduced stiffness and increased elongation.

Background Several risk factors for adult acquired flatfoot deformity (AAFD) have been identified in literature. To this date, little attention has been paid to the lateral ligament complex and its influence on AAFD, although its anatomic course and anatomic studies suggest a restriction to flatfoot deformity. The aim of this study was to assess the influence of the anterior talofibular ligament (ATFL) on AAFD and on radiologic outcome following common operative correction by lateral calcaneal lengthening. Methods We reviewed all patients that underwent lateral calcaneal lengthening for correction of AAFD between January 2008 and July 2018 at our clinic. Patients were grouped according to the preoperative MRI findings into those with an intact ATFL and those with an injured ATFL. Two independent readers assessed common radiographic flatfoot parameters on preoperative and postoperative radiographs. Results Sixty-four flatfoot corrections in 63 patients were included, whereby the ATFL was intact in 29 cases, and in 35 cases the ligament was injured. An ATFL lesion was overall radiologically associated with increased flatfoot deformity with a statistically significant difference between the two groups for preoperative talometatarsal-angle (p = 0.002), talocalcaneal-angle (p = 0.000) and talonavicular uncoverage-angle (p = 0.005). No difference between the two groups could be observed regarding the success of operative correction or operative consistency after lateral calcaneal lengthening. Conclusion The ATFL seems to influence the extent of AAFD. In patients undergoing lateral calcaneal lengthening, the integrity of the ligament seems not to influence the degree of correction or the consistency of the postoperative result., BMC Musculoskeletal Disorders, 20 (1), ISSN:1471-2474

Background The biomechanical effects of joint-line medialization during shoulder surgery are poorly understood. It was therefore the purpose of this study to investigate whether medialization of the joint line especially associated with total shoulder arthroplasty leads to changes in the rotator cuff muscle forces required to stabilize the arm in space. Methods A validated computational 3-D rigid body simulation model was used to calculate generated muscle forces, instability ratios, muscle-tendon lengths and moment arms during scapular plane elevation. Measurements took place with the anatomical and a 2 mm and 6 mm lateralized or medialized joint line. Results When the joint line was medialized, increased deltoid muscle activity was recorded throughout glenohumeral joint elevation. The rotator cuff muscle forces increased with medialization of the joint line in the early phases of elevation. Lateralization of the joint line led to higher rotator cuff muscle forces after 52° of glenohumeral elevation and to higher absolute values in muscle activity. A maximum instability ratio of >0.6 was recorded with 6 mm of joint-line medialization. Conclusion In this biomechanical study, medialization and lateralization of the normal joint line during total shoulder arthroplasty led to substantial load changes on the shoulder muscles used for stabilizing the arm in space. Specifically, medialization does not only lead to muscular shortening but also to increased load on the supraspinatus tendon during early arm elevation, the position which is already most loaded in the native joint.

Background Progressive collapsing foot deformity (PCFD) is a complex 3-dimensional (3-D) deformity with varying degrees of hindfoot valgus, forefoot abduction, and midfoot varus. The first aim of this study was to perform a 3-D analysis of the talus morphology between symptomatic PCFD patients that underwent operative flatfoot correction and controls. The second aim was to investigate if there is an impact of individual talus morphology on the success of operative flatfoot correction. Methods We reviewed all patients that underwent lateral calcaneal lengthening for correction of PCFD between 2008 and 2018 at our clinic. Radiographic flatfoot parameters on preoperative and postoperative radiographs were assessed. Additionally, 3-D surface models of the tali were generated using computed tomography (CT) data. The talus morphology of 44 flatfeet was compared to 3-D models of 50 controls without foot or ankle pain of any kind. Results Groups were comparable regarding demographics. Talus morphology differed significantly between PCFD and controls in multiple aspects. There was a 2.6° increased plantar flexion (22.3° versus 26°; p = 0.02) and medial deviation (31.7° and 33.5°; p = 0.04) of the talar head in relation to the body in PCFD patients compared to controls. Moreover, PCFD were characterized by an increased valgus (difference of 4.6°; p = 0.01) alignment of the subtalar joint. Satisfactory correction was achieved in all cases, with an improvement of the talometatarsal-angle and the talonavicular uncoverage angle of 5.6° ± 9.7 (p = 0.02) and 9.9° ± 16.3 (p = 0.001), respectively. No statistically significant correlation was found between talus morphology and the correction achieved or loss of correction one year postoperatively. Conclusion The different morphological features mentioned above might be contributing or risk factors for progression to PCFD. However, despite the variety of talar morphology, which is different compared to controls, the surgical outcome of calcaneal lengthening osteotomy was not affected. Level of evidence III.

Background: Peroneal tendon lesions can cause debilitating pain, but operative treatment remains controversial. Some studies recommend peroneal tenodesis or transfer if more than half of the tendon is affected. However, clinical outcomes and inversion/eversion motion after peroneal transfer have not been investigated yet. Methods: Patients who underwent distal peroneus longus to brevis transfer for major peroneus brevis tendon tears with a minimum follow-up of 2 years were included. Clinical outcome parameters included the American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score, the German Foot Function Index (FFI-D), and Karlsson-Peterson score. Functional outcome was tested with a standardized active range-of-motion (ROM) and isokinetic strength measurement protocol, including concentric and eccentric eversion and inversion tests. Results: Of total 23 eligible patients, 14 (61%) were available for follow-up. Clinical outcome scores were good with AOFAS 86 ± 16 points, FFI-D pain 26% and FFI-D disability 26%, and Karlsson-Peterson score 78 ± 23 points. There was no difference in strength in comparison to the contralateral foot (all P > .05). Isokinetic strength was 16.3 ± 4.9 Nm (108% of contralateral side) and 18.8 ± 4.5 Nm (101%) at concentric 30 deg/s and eccentric 30 deg/s eversion tests, as well as 15.7 ± 5.2 Nm (102%) and 18.7 ± 3.3 Nm (103%) at concentric 30 deg/s and eccentric 30 deg/s inversion tests, respectively. There was no difference in ROM compared to the contralateral side (eversion/inversion 14.5-0-18.7 vs 14.1-0-16.1 degrees). Conclusion: Peroneus longus to brevis transfer is a viable option for treating severe peroneus brevis tendon tears and does not compromise measurable strength or ROM in inversion or eversion in comparison to the contralateral ankle joint. Level of Evidence: Level IV, prospective case series.

Background:Autologous matrix-induced chondrogenesis (AMIC) has been shown to result in favorable clinical outcomes in patients with osteochondral lesions of the talus (OLTs). Though, the influence of ankle instability on cartilage repair of the ankle has yet to be determined.Purpose/Hypothesis:To compare the clinical and radiographic outcomes in patients with and without concomitant lateral ligament stabilization (LLS) undergoing AMIC for the treatment of OLT. It was hypothesized that the outcomes would be comparable between these patient groups.Study Design:Cohort study; Level of evidence, 3.Methods:Twenty-six patients (13 with and 13 without concomitant ankle instability) who underwent AMIC with a mean follow-up of 4.2 ± 1.5 years were enrolled in this study. Patients were matched 1:1 according to age, body mass index (BMI), lesion size, and follow-up. Postoperative magnetic resonance imaging and Tegner, American Orthopaedic Foot & Ankle Society (AOFAS), and Cumberland Ankle Instability Tool (CAIT) scores were obtained at a minimum follow-up of 2 years. A musculoskeletal radiologist scored all grafts according to the MOCART (magnetic resonance observation of cartilage repair tissue) 1 and MOCART 2.0 scores.Results:The patients’ mean age was 33.4 ± 12.7 years, with a mean BMI of 26.2 ± 3.7. Patients with concomitant LLS showed worse clinical outcome measured by the AOFAS (85.1 ± 14.4 vs 96.3 ± 5.8; P = .034) and Tegner (3.8 ± 1.1 vs 4.4 ± 2.3; P = .012) scores. Postoperative CAIT and AOFAS scores were significantly correlated in patients with concomitant LLS ( r = 0.766; P = .002). A CAIT score >24 (no functional ankle instability) resulted in AOFAS scores comparable with scores in patients with isolated AMIC (90.1 ± 11.6 vs 95.3 ± 6.6; P = .442). No difference was seen between groups regarding MOCART 1 and 2.0 scores ( P = .714 and P = .371, respectively).Conclusion:Concurrently performed AMIC and LLS in patients with OLT and ankle instability resulted in clinical outcomes comparable with isolated AMIC if postoperative ankle stability was achieved. However, residual ankle instability was associated with worse postoperative outcomes, highlighting the need for adequate stabilization of ankle instability in patients with OLT.

An established treatment strategy in surgical site infection after hindfoot and ankle surgery is a two-stage procedure with debridement and placement of a cement spacer, followed by antibiotic treatment and secondary arthrodesis. However, there is little evidence to favor this treatment over a one-stage procedure with debridement, followed by primary arthrodesis with an Ilizarov external fixator and antibiotic treatment. We compared the infection control and clinical and radiological outcome of a two-stage and a one-stage procedure. In this study, 7 patients with a two-stage revision and 11 patients with a one-stage revision between 2005 and 2015 were included. The primary outcome was infection control (absence of the Musculoskeletal Infection Society PJI criteria) 2 years after the ankle or hindfoot arthrodesis. Secondary outcome measures were the AOFAS hindfoot score and radiological consolidation rate. Infection control was 85% (6 out of 7 patients) in the two-stage group and 81% (9 out of 11 patients) in the one-stage group (p = 1.0). One patient (14%) of the two-stage and two patients (18%) in the one-stage group needed below-knee amputation. In the two-stage group, the mean postoperative AOFAS score was 74.8 (SD: ±11.3) versus 71.7 (SD: ±17.8) in the one-stage group. Radiological consolidation could be achieved in 71% in the spacer group (n = 5) and in 72% in the Ilizarov external fixator group (n = 9). Infection control, AOFAS score, and radiologic consolidation of hindfoot and ankle arthrodesis were comparable in both groups of patients with complicated postsurgical hindfoot or ankle infections.

Axial plane alignment of the talar component in total ankle arthroplasty is poorly understood and remains a major issue, especially since malpositioning results in increased peak pressure and rotational torque. Further profound knowledge regarding individual anatomy of the talus and its relation to proximal and distal osseous structures is therefore needed. Therefore, three-dimensional (3D) surface models of 50 lower extremities were generated using computed tomography data of patients without ankle osteoarthritis. The talus neck torsion was measured using a novel 3D measurement method. Then, tibial torsion and subtalar joint axis orientation were measured and correlated to the talus neck torsion. Moreover, a 2D measurement method of the talus neck torsion was developed. A statistically significant correlation was found between external tibia torsion and medial talus neck torsion, as well as talus neck axis and subtalar joint axis in the transversal and frontal plane. The novel defined 3D measurement methods indicated excellent inter-rater and intra-rater reliability. The 2D measurement method of the talus neck torsion was in good agreement with the 3D method. The results showed that the rotational profiles of the tibia, talus, and adjacent joints are interconnected, which should be considered in total ankle replacement (TAR). Clinical relevance: This study improves the overall understanding of the talar anatomy, as well as its relationship to adjacent osseous structures. The novel 2D measurement method of the talus neck torsion might improve talar component positioning in the axial plane corresponding to the patient's individual anatomy, and therefore improve the survival rate of TAR.

Aim Currently, cohort studies reported the use of minimally invasive arthrodesis of the first metatarsophalangeal joint (MTP I). The aim of this systematic literature review was to analyse clinical, radiological outcome and complications with this technique. Methods A systemic literature search of the databases Google Scholar, PubMed, Scopus, EMBASE and Cochrane to identify studies reporting on clinical, radiological outcome or complications of minimally invasive MTP I arthrodesis was conducted. Results A total of 6 studies (1 Level V, 5 Level IV) reporting on 109 minimally invasive MTP arthrodesis in 105 patients were included. Validated scores were reported in 103 cases. Clinical outcome improved in 57 cases from a mean of 36.9 to 82.6 points American Orthopedic Foot and Ankle Score (AOFAS) and in 46 cases from 38.7 to 18.4 points Manchester Oxford Foot Questionnaire (MOXFQ). Radiological fusion rate was 87% (n = 94 out of 109) achieved after 6-12 weeks. Overall complication rate was 11.9% (13 cases) leading to revision surgeries in 5.5% (6 cases). Most common complications Most common complications were symptomatic non-union (n = 6, 5.5%), asymptomatic non-union (n = 2, 1.8%) and subsequent interphalangeal joint arthritis (n = 2, 1.8%). Conclusion Minimally invasive MTP I arthrodesis is a promising technique with comparable clinical, radiological outcome and complication rates to open surgery in hallux rigidus and rigido-valgus. Future studies are needed providing higher level of evidence to prove the potential benefit of minimally invasive compared to open MTP I arthrodesis.

The subtalar joint plays an important role for the hindfoot when accommodating during gait. Joint degeneration may be caused by posttraumatic, inflammatory, and pathologic biomechanical changes. Once conservative treatment has failed, subtalar fusion should be considered. The indication for surgery is based on thorough clinical and radiographic evaluation. Several techniques for subtalar fusion are published in literature. This article aims to describe a technique for in situ arthrodesis of the subtalar joint, paying special attention to biomechanical aspects as well as preoperative clinical and radiological work-up.

The precise planning of metatarsal (MT) I length in hallux valgus surgery is important. However, currently no tool exists which allows the surgeon to reliably predict this parameter.30 virtual 3-dimensional hallux valgus surgeries were performed on varied deformation models based on cadaveric feet scans. The shortening of the first ray during distal metatarsal I osteotomy for different osteotomy angles were measured. An algebraic 2-dimensional calculation was done and compared to the results obtained from the 3-dimensional models.Inadvertent shortening of the first metatarsal bone can be as much as 8 mm depending on the amount of intermetatarsal angle (IMA) correction and osteotomy angle. Comparison of the 3 dimensional simulations and the 2 dimensional model resulted in a very strong correlation (R0.99 p0.00001). Based on our findings an anterior pointing osteotomy of approximately 10° is necessary to restore the length in distal metatarsal I hallux valgus surgery.A slight misdirection of the osteotomy plane in distal hallux valgus surgery may result in relevant unwanted alterations in first metatarsal bone length and triangulation by eye is insufficient in this complex geometrical situation without appropriate planning. The present study provides surgeons a practical tool to plan and control the change of first metatarsal length during hallux valgus procedure through exact orientation of the osteotomy angle. If no alteration of length is intended, it may be generalized that an anterior direction of the cut relative to the second metatarsal bone will preserve the length of the first metatarsal bone.