Predictors of flatfoot in 11-12-year olds: a longitudinal cohort study.

BACKGROUND: The structures around the navicular bones, which constitute the medial longitudinal arch, develop by 10 years of age. While navicular bone height is often emphasized in the assessment of flatfoot, three-dimensional (3D) evaluations, including those of structural parameters during inversion, have rarely been investigated. If the development of flatfoot during the growth process could be predicted, appropriate interventions could be implemented. Therefore, in this longitudinal cohort study, we developed a system, utilizing smartphones, to measure the 3D structure of the foot, performed a longitudinal analysis of changes in midfoot structures in 124 children aged 9-12 years, and identified factors influencing the height of the navicular bone. The foot skeletal structure was measured using a 3D system. RESULTS: Over 2 years, foot length and instep height increased during development, while navicular height decreased. The 25th percentile of the instep height ratio and navicular height ratio at ages 9-10 years did not exceed those at ages 11-12 years, with percentages of 17.9% and 71.6%, respectively, for boys, and 15.8% and 49.1%, respectively, for girls. As the quartiles of the second toe-heel-navicular angle (SHN angle) increased at ages 9-10 years, the axis of the bone distance (ABD) and SHN angles at ages 11-12 years also increased, resulting in a decrease in the navicular height ratio. A significant inverse correlation was found between changes in SHN angle and navicular height ratio. These findings indicate that the navicular bone rotation of the midfoot is a predictor of the descent of the navicular bone. CONCLUSIONS: This study revealed that some children exhibit decreases in navicular bone height with growth. As a distinct feature, the inversion of the navicular bone promotes flattening of the midfoot. Thus, this study provides insights into changes in midfoot development in children and provides an effective evaluation index.

Accessory foot bones in a Portuguese identified skeletal collection.

Data from dry bone samples, collected from anatomical or archaeological collections, can improve the knowledge regarding accessory foot bones, including prevalence, size, shape and laterality, that can be useful in disparate fields of research, from medicine to bioarcheology. In the present study, the prevalence of six accessory foot bones (os trigonum, calcaneus secundarium, accessory navicular bone, os vesalianum, os sustentaculum and os intermetatarseum) was assessed in a sample of 486 individuals (226 females, 260 males) from the Coimbra Identified Skeletal Collection (CISC). The most frequent accessory bones are os trigonum (9.9%; 48/485) and calcaneus secundarium (6.0%; 29/486), while the most uncommon is os sustentaculum (0.4%; 2/486). No sex differences were observed. All accessory bones occur more often unilaterally, with the exception of the accessory navicular bone that, in the majority of cases, occurs bilaterally. The unilateral expression of os trigonum, calcaneus secundarium and os vesalianum was mostly in the right foot. The co-occurrence of accessory foot bones was recorded in 1.7% of the individuals (8/486), and the combinations of os trigonum and calcaneus secundarium were the most frequently observed. This research emphasizes the relevance of conducting studies on reference skeletal collections in order to gain a comprehensive understanding of anatomical variations in the foot. This understanding is crucial for accurate diagnoses and successful treatment in clinical settings, as well as for establishing population comparison standards in the fields of bioarchaeology and forensic anthropology.

Three-Dimensional-Printed Patient-Specific Total Cuboid Replacement for Treatment of Post-traumatic Arthritis: A Case Report.

Cuboid injuries, including fractures, are rare and infrequently occur in isolation. Often, cuboid injuries can be treated nonoperatively. However, when surgery is indicated, appropriate management is necessary for maintaining the associated biomechanics of the midfoot. Current procedures for surgical management of the cuboid include open reduction and internal fixation, application of external fixation, or primary arthrodesis of the calcaneocuboid joint. Secondary procedures for symptomatic or poor outcomes of nonoperative and operative cuboid injuries consist of corrective osteotomy, bone resection, and interpositional arthroplasty. We present a novel surgical technique using a patient-specific three-dimensional-printed total cuboid replacement. This is an alternative treatment for post-traumatic arthritis of the cuboid along with a shortened lateral column. A single case example is given as well as details and discussion of the surgical technique.

A Case Report of Brodie's Abscess of the Cuboid Treated by Anatomic Antibiotic-Cement Spacer.

Background: A case of chronic osteomyelitis with Brodie's abscess of the cuboid caused by a wooden foreign body penetrating the plantar foot. Total cuboidectomy was carried out with implantation of an anatomically molded antibiotic-impregnated cement spacer with culture-specific postoperative intravenous antibiotics. At six months of follow-up, the patient was completely asymptomatic without evidence of a recurrence of infection. Final radiographs also didn't show spacer migration or surrounding bone erosions. The spacer obviated the need for any foot fusion which preserved foot biomechanics. The patient didn't need to use any braces or insoles. Conclusion: Osteomyelitis should always be on the differential list of lytic lesions of the tarsal bones, especially if there is a history of prior foot trauma. In this case, cuboid excision and placement of an antibiotic-impregnated cement spacer provided sustained relief of symptoms without evidence of recurrence or complications for six months.Level of Evidence: V.

Clinical Effects of Tibial Posterior Tendon Reconstruction in the Treatment of Young Athletes With Accessory Navicular Bone Syndrome.

OBJECTIVE: To compare the effects of anchor reconstruction of posterior tibial tendon with the traditional Kidner's procedure for accessory navicular bone syndrome. METHODS: A retrospective analysis was conducted on 40 young athletes diagnosed with accessory navicular bone syndrome who were admitted to our hospital from 2018 to 2021. Among them, 20 patients underwent the modified Kidner procedure for the anchor reconstruction of the posterior tibial tendon (Experimental group), while the remaining 20 patients were treated with the traditional Kidner's procedure (Control group). Regular follow-ups were conducted to evaluate the degree of relief of foot symptoms and functional recovery. RESULTS: All patients were followed up for 12 to 24 months (mean duration: 18.6±3.7) after the operation. At the last follow-up, significant differences were observed in the function and symptom relief of the affected foot compared to the preoperative state. The experimental group had a mean operation time of 52.10 ± 3.41 minutes, significantly shorter than the control group's 61.25 ± 2.75 minutes. The mean time to return to normal activity was 12.65 ± 1.23 weeks for the experimental group, compared to 15.25 ± 1.16 weeks for the control group. CONCLUSION: The modified Kidner procedure demonstrates a higher patient satisfaction rate compared to the traditional Kidner procedure. This is attributed to its shorter duration, reduced trauma, and quicker recovery of normal activity.

Navicular and Cuboid Fractures.

Navicular and cuboid fractures can be complex and difficult to treat. Depending on the mechanism of injury, diagnosis of such fractures is not always possible with conventional radiographs due to the irregularity and overlap of the midfoot bones. Advanced imaging is indicated if a fracture is of high suspicion or to further characterize a displaced fracture. Cuboid and navicular fractures can occur in isolation but are often associated with other midfoot injuries due to their anatomic relationships. Typically, nondisplaced fractures can be treated conservatively, whereas displaced fractures require surgical intervention to prevent future complications.

Morphological measurements and classification of the navicular bone: a study based on computed tomography imaging.

OBJECTIVE: The purpose of this study was to present the classification of navicular bones and the anatomical basis for the diagnosis and treatment of navicular fractures of the foot. METHOD: 351 computed tomographic (CT) images of the navicular bone were analyzed and classified. The navicular bone's anatomical morphology was measured by three independent researchers in each type. Analysis and recording of the measurement results followed. RESULT: Navicular bones were assorted into three types: I shape(37.04%), II shape(54.41%), and III shape(8.55%). The left and right sides did not differ in any appreciable ways, except ab, bc, and ∠abc (P < 0.05); And all data were statistically different between men and women except for ∠abc (p > 0.05). CONCLUSION: The classification of the navicular bone in this study may be helpful in making the treatment decision for navicular fracture. LEVEL OF CLINICAL EVIDENCE: 4.

[Navicular bone fractures in horses: Prognosis after conservative and surgical treatment]. / Strahlbein-Frakturen beim Pferd: Prognose nach konservativer und chirurgischer Therapie.

INTRODUCTION: The aim of this retrospective study is to describe and compare conservative and surgical treatment of navicular fractures in horses. An attempt is made to identify critical points that can favorably influence the prognosis of this orthopedic disease. All horses treated for a navicular fracture at the Equine Clinic, Vetsuisse Faculty, University of Zurich between 2005 and 2017 were included in this study. The severity of lameness at initial examination, radiographic assessment, hoof conformation, treatment (conservative or surgical), complications and outcome were determined from the medical records. Conservative and surgical treatment consisted of stable rest, a controlled exercise program and therapeutic orthopedic shoeing. During surgical treatment, fracture reduction was also carried out with a cortical screw. Computer assisted surgery were used in five horses and computer tomography in three horses. Follow-up examinations included clinical and radiographic examinations. The outcome was divided into three categories: 1 = very good; 2 = good; 3 = poor. Twelve horses met the inclusion criteria; Four horses were treated conservatively and eight were treated surgically. After conservative treatment, two horses (50 %) had a very good outcome and two (50 %) had a good outcome. After surgical treatment, four horses (50 %) had a very good outcome and four (50 %) had a poor outcome. Overall, 67 % of horses had a very good or good outcome, although radiographic signs of bone healing was not present in any of these cases. Various complications were identified, such as the fracture of a screw, the fragmentation of the small navicular bone fragment, the development of osteoarthrosis in the coffin joint and progressive podotrochosis. This study shows that the prognosis of navicular fractures is generally cautious and that degenerative changes to the navicular apparatus worsen the prognosis. In the present study, surgical treatment did not improve the prognosis of navicular fractures despite the intrasurgical use of three-dimensional imaging. However, technical advances could reduce the complication rate in the future.

INTRODUCTION: Le but de cette étude rétrospective était de décrire et de comparer le traitement conservateur et chirurgical des fractures de l'os naviculaires chez le cheval. Une tentative est faite pour identifier les points critiques qui peuvent influencer favorablement le pronostic de cette maladie orthopédique. Tous les chevaux traités pour une fracture de l'os naviculaire à la Clinique équine de la Faculté Vetsuisse de l'Université de Zurich entre 2005 et 2017 ont été inclus dans cette étude. La gravité de la boiterie lors de l'examen initial, l'évaluation radiographique, la conformation du sabot, le traitement (conservateur ou chirurgical), les complications et le résultat ont été déterminés à partir des dossiers médicaux. Le traitement conservateur et chirurgical consistait en un repos au box, un programme d'exercice contrôlé et un ferrage orthopédique thérapeutique. Au cours du traitement chirurgical, une réduction de la fracture a également été effectuée à l'aide d'une vis corticale. La chirurgie assistée par ordinateur a été utilisée sur cinq chevaux et la tomographie assistée par ordinateur sur trois chevaux. Les examens de suivi comprenaient des examens cliniques et radiographiques. Les résultats ont été divisés en trois catégories: 1 = très bon; 2 = bon; 3 = mauvais. Douze chevaux répondaient aux critères d'inclusion ; quatre chevaux ont été traités de manière conservatrice et huit ont été traités chirurgicalement. Après un traitement conservateur, deux chevaux (50 %) ont eu un très bon résultat et deux (50 %) un bon résultat. Après le traitement chirurgical, quatre chevaux (50 %) ont eu un très bon résultat et quatre (50 %) un mauvais résultat. Dans l'ensemble, 67 % des chevaux ont eu un très bon ou un bon résultat, bien que les signes radiographiques de guérison osseuse n'aient été présents dans aucun de ces cas. Diverses complications ont été identifiées, telles que la fracture d'une vis, la fragmentation du petit fragment de l'os naviculaire, le développement d'une arthrose dans l'articulation interphalangienne distale et une podotrochlose progressive. Cette étude montre que le pronostic des fractures de l'os naviculaire est généralement réservé et que les modifications dégénératives de l'appareil naviculaire aggravent le pronostic. Dans la présente étude, le traitement chirurgical n'a pas amélioré le pronostic des fractures du naviculaire malgré l'utilisation intra-chirurgicale de l'imagerie tridimensionnelle. Cependant, les progrès techniques pourraient réduire le taux de complications dans le futur.

Simultaneous subtalar arthroeresis, midfoot soft tissue release, and talo-navicular arthrodesis in children with planovalgus neurologic foot.

PURPOSE: Planovalgus foot deformity (PVFD) is common in children with neuromuscular conditions and severe deformity may require surgical correction. This study aims to assess clinical and radiological outcomes of PVFD secondary to neuromuscular disease managed by subtalar arthroeresis (SuAE), midfoot soft tissue release and talo-navicular arthrodesis (TNA). METHODS: A retrospective analysis of children with neuromuscular disease and nonreducible PVFD who underwent SuAE, midfoot soft tissue release, and TNA and with a minimum follow-up of 5 years was performed. A total of 60 patients with neuromuscular disease (108 feet) including cerebral palsy were reviewed. Mean age at surgery was 12.7 ± 4.6 years (6-17). Mean follow-up was 7 ± 2.9 years (5-10). Clinical outcomes and radiologic correction at final follow-up were compared with preoperative values. Statistical analysis was performed and significance was set at P < 0.01. RESULTS: Statistically significant radiological improvements between pre- and postoperative values were found for all angle values. At final follow-up, there was a significant improvement in VAS score (4.8 vs. 2; P < 0.01). There was also a positive trend in the improvement of walking ability. No cases of pseudoarthrosis were reported at final follow-up. Screw removal was required in 5 out of 108 feet (4.6%) and 2 feet (3.3%) had delayed medial wound healing. CONCLUSIONS: SuAE combined with TNA and midfoot soft tissue is a safe and feasible procedure that can provide good clinical and radiologic results in patients with neuromuscular disease and nonreducible PVFD; the procedure can improve foot stability, and has a limited number of complications. LEVEL OF EVIDENCE: IV.

Talonavicular-cuneiform arthrodesis in the management of Mueller-Weiss Syndrome: a retrospective case series.

Mueller-Weiss Syndrome (MWS), characterized by spontaneous adult-onset tarsal navicular osteonecrosis, is an uncommon cause of chronic midfoot pain that can lead to functional impairment and progressive deformities. This study aimed to present clinical and radiological outcomes of talonavicular-cuneiform (TNC) arthrodesis in the treatment of patients with MWS. A retrospective study was performed on 8 consecutive patients (6 female, 2 male; mean age = 50 years; range = 33-64) who underwent TNC arthrodesis using plate fixation with autologous bone grafting for the treatment of MWS. To evaluate clinical status, the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Midfoot Score was performed immediately preoperatively and at the final follow-up. In radiographic evaluation, talus-first metatarsal angle (Meary's angle) was measured preoperatively and at the final follow-up. Solid fusion was also examined on postoperative radiographs and computerised tomography. The mean follow-up was 35 months (range = 24-52). The mean AOFAS improved from 37 (range = 24-53) preoperatively to 85 (range = 80-93) at the final follow-up (p < 0.001). No major intra- operative complications were observed in any of the patients. According to the Maceira and Rochera radiological staging system, 5 feet was stage 3, and 3 feet was stage 4. The mean union time was 10 months (range = 5-15). Radiographic solid fusion was achieved in all but one foot that developed talonavicular non-union. TNC arthrodesis using plate fixation with autologous bone grafting seems to be an effective surgical method for reconstruction of MWS.

[Postoperative outcome of 30 patients with navicular bone fractures-In connection with AOFAS-Score, SF-12 and fracture classifications]. / Das postoperative Outcome von 30 Patienten mit Os-naviculare-Fraktur ­ im Zusammenhang mit AOFAS-Score, SF-12 und Frakturklassifikationen.

BACKGROUND: Fractures of the navicular bone are rare and the number of those treated surgically is even smaller. Moreover, scientific analyses on this topic are only sporadically present in the literature, therefore this retrospective and monocentric study was initiated. METHODS: A total of 30 patients with 30 fractures were included. With the exception of one primary fusion, all patients underwent open reduction with internal osteosynthesis. Clinical and radiological follow-up was performed at least 2 years postoperatively using AOFAS-Score, SF-12 and a radiological examination. The primary objectives were the clinical and radiologic outcomes as mid-term to long-term outcomes. The secondary objective was to compare these results with two existing computed tomography (CT) fracture classifications in terms of their association with the outcome. RESULTS: The median follow-up was 7.8 years (range 2-16.2 years) postoperatively. One patient suffered an infection, four patients required secondary arthrodesis and eight patients had to change their occupation. The mean AOFAS-Score was 80.8/100 and the mean physical and mental SF-12 component summary scores were 47.1 and 55.7 points, respectively. Male sex and arthrodesis were associated with worse outcomes in both scores but not patient age or ipsilateral concomitant injuries. Both CT fracture classifications showed low predictive value. CONCLUSION: The severity of the injury in the preoperative CT showed no connection with the clinical outcome in the AOFAS-Score and SF-12 scores. Posttraumatic osteoarthritis and secondary arthrodesis are associated with a poor outcome. In the course of the observational period the reduction results improved, which was accompanied by a better clinical outcome.

Tarsals from the Sima de los Huesos Middle Pleistocene site (Atapuerca, Burgos, Spain).

Here, we provide a complete, updated, and illustrated inventory, as well as a comprehensive study, of the tarsals (rearfoot) recovered from the Middle Pleistocene site of Sima de los Huesos (SH, Atapuerca, Spain) in comparison to other Homo comparative samples, both extant and fossil. The minimum number of individuals (MNI) estimated from the tarsals has been established as 15, which represents 51.7% of the 29 dental individuals identified within the SH sample. Within the SH hominin foot sample, an exclusive combination of primitive or plesiomorphic and derived or autapomorphic traits can be observed when compared with other Homo individuals/populations. Other characters are shared among SH hominins and Neandertals that might represent shared derived or autapomorphic traits for this evolutionary line, and most are likely related to robusticity (e.g., rectangular-like trochlea of the talus, broad calcanei, broad naviculars, and short lateral cuneiforms). Additionally, we observed some exclusive autapomorphic traits in the SH tarsal sample (e.g., narrow head of the talus and short intermediate cuneiforms). A few exclusive traits in SH tarsal remains are even more robust than in Neandertals (e.g., broad lateral malleolar facet in talus, more projected sustentaculum tali, and broad medial cuneiform). These traits could suggest a slightly higher level of gracilization in the tarsal bones of Neandertals compared to the SH sample that is also supported by other anatomical postcranial skeleton elements. Additionally, some paleobiological inferences are made in relation to body size (stature and body mass) and some associations are proposed within the SH sample. In conclusion, the morphology of the SH tarsi confirms an evolutionary relationship of sister groups between this population and Neandertals, probably representing a morphotype similar to the Neandertal ancestors.

Treatment of Symptomatic Os Supranaviculare in Athletes.

BACKGROUND: Although the incidence of os supranaviculare (OSSN) is generally low, symptomatic OSSN affects athletes. The aim of this study was to assess the variations of OSSN and the results of osteosynthesis between the OSSN and the navicular bone. METHODS: Eleven feet of 10 elite athletes with symptomatic OSSN were treated. There were 3 male and 7 female patients with an average age of 19 years. Eight feet exhibited navicular stress fracture (NSF). Operative treatment was performed in 9 feet of 8 patients and 2 conservatively. Seven OSSNs were fixed with 1 or 2 screw(s) according to their size, using an autologous bone graft. The accompanying NSF was also treated surgically in 4 feet. Foot condition was evaluated using the Japanese Society for Surgery of the Foot (JSSF) midfoot rating scale and sports activity score of the Self-Administered Foot Evaluation Questionnaire (SAFE-Q). RESULTS: The median OSSN was 12.7 mm in width, 5.6 mm in length, and 6.6 mm in height. The dorsal surface of the OSSN required at least 70 mm2 to be fixed using 2 screws. Seven OSSNs of 6 patients treated surgically successfully fused with the navicular. Two small OSSNs that were not stabilized with screws also fused after surgical treatment for NSF. However, one of the 2 OSSNs with NSF treated nonoperatively did not achieve fusion. The patients were followed up for 24-161 months. The median JSSF score improved from 87 to 97.7 postoperatively (P = .00312). The median postoperative SAFE-Q sports score was 84.8. All patients returned to their original activities. CONCLUSION: Our results suggest that osteosynthesis with autologous bone graft was effective for symptomatic OSSNs. Even when the OSSN was small and not suitable for internal fixation, treatment of NSF was effective for union of OSSNs. The OSSN possibly belongs to a part or subtype of NSF.

A case report of multicentric carpotarsal osteolysis syndrome: Depiction of a debilitating disease course.

Multicentric carpotarsal osteolysis syndrome (MCTO) is a rare skeletal disorder characterized by progressive osteolysis involving the carpal and tarsal bones, and often associated with nephropathy. It is caused by heterozygous mutation in the MAF bZIP transcription factor B (MAFB) gene. Heterogeneous clinical manifestation and wide spectrum of disease severity have been observed in patients with MCTO. Here, we report a case of a male patient who presented with kidney failure in childhood with progressive disabling skeletal deformity. He was diagnosed with MCTO at 31-years-old, where a de novo pathogenic heterozygous variant in NM_005461.5:c.212C>A: p.(Pro71His) of the MAFB gene was identified. While there has been little data on the long-term prognosis and life expectancy of this disease, this case report sheds light on the debilitating disease course with multiple significant morbidities of a patient with MCTO throughout his lifetime of 33 years.

Torques in the human upper ankle joint level and their importance in conservative and surgical treatment.

The paper deals with the torques of external muscles acting on the upper ankle joint under weight-bearing conditions and their importance in diagnosing and treating the human foot. Experimental data were collected and calculations were performed. Based on the experiments with the biomechanical model of the foot and upper ankle joint, it was shown how the changes in the force arms of the external muscles of the foot under weight-bearing conditions, change the torque. The real values of muscle forces and torques of the external muscles of the foot were calculated. Taking into account the distance of the lines of muscle action from the axis of rotation of the upper ankle joint the rotational force of the muscles was calculated. The influence of changing the force arm on the rotational efficiency of the muscle balancing the moment of gravity was shown. Knowledge of muscle torque under weight-bearing conditions is crucial for correctly assessing foot biomechanics. It has been shown that torque (gravitational and muscular), not pure force, is crucial when assessing the rotational capacity of the analyzed joint. A change in the approach to diagnostics and treating paresis or weakness of extrinsic foot muscles was proposed through the manipulation of the distance of their action line from the axis of joint rotation.

Clinical report of microsurgical treatment of Kohler's disease.

The conservative treatment for Kohler's disease will take several months, but some patients still have flatfoot and persistent pain. From October 2013 to July 2015, 3 children with Kohler's disease underwent navicular decompression and micro-circulation reconstruction surgery in our hospital. All the patients have received conservative treatment for more than 3 months and the effect was poor. X-ray showed the bone density of navicular increased significantly. All patients were followed up over 1 year. The 3 patients recovered well. VAS score decreased from 7.0 to 2.6 at 1 month after the operation. The pain symptom disappeared completely on 3 months after surgery. The density of navicular bone recovered to normal. Navicular decompression and micro-circulation reconstruction surgery may quickly improve the ischemic status of navicular bone, alleviate pain symptom and enable patients to resume normal activity as soon as possible.

Effect of foot orthoses on balance among individuals with flatfoot: A systematic review and meta-analysis.

Individuals with flatfoot have impaired proprioception owing to ligament laxity and impaired tendons, which can result in poor balance. Foot orthoses (FOs) have been reported to stimulate plantar mechanical receptors and are used to manage foot overpronation in individuals with flatfoot. However, the results of the use of FOs to improve balance are inconsistent. In this systematic review and meta-analysis, we aimed to identify and investigate the effects of FOs on balance in individuals with flatfoot. Electronic databases were searched for articles published before March 2023. Peer-reviewed journal studies that included adult participants with flexible flatfoot and reported the effects of FOs on balance were included and classified based on the study design: randomized control trials (RCT) and non-RCTs. Four RCT studies were retained, and their methodological quality was assessed (mean, 63.2%; range 47.3%-73.1%: high), as were three non-RCT studies (mean, 54.1%; range, 42.1%-68.4%: high). Meta-analysis was performed by calculating the effect size using the standardized mean differences between the control and FO conditions. Transverse-arch insoles immediately improved static balance after use. However, no immediate significant effect was found for medial archsupport FOs, cuboid-posting FOs, or University of California Berkeley Laboratory FOs during the study period (2-5 weeks) when compared with the controls. The transverse-arch insole is the most effective FO feature for improving static balance. However, the high heterogeneity between study protocols contributes to the lack of evidence for the effects of FO on balance in people with flatfoot.

Normal and malaligned talonavicular fusion alters cadaveric foot pressure and kinematics.

Talonavicular (TN) fusion is a common treatment for TN arthritis or deformity correction. There is incongruous evidence regarding remaining motion at the talocalcaneal and calcaneocuboid joints after TN fusion. Additionally, the effects of a malaligned TN fusion are not well understood and alignment of the fusion may be important for overall foot integrity. This project assessed the kinematic and kinetic effects of neutral and malaligned TN fusions. Ten cadaveric feet were tested on a gait simulator in four conditions: unfused, fused in neutral, fused in varus, and fused in valgus. The fusions were simulated with external fixation hardware. An eight-camera motion analysis system and a 10-segment foot model generated kinematic data, and a pressure mat captured pressure data. Simulated TN fusion was achieved in eight feet. From unfused to fused-neutral, range of motion (ROM) was not eliminated in the adjacent joints, but the positions of the joints changed significantly throughout stance phase. Furthermore, the ROM increased at the tibiotalar joint. Plantar pressure and center of pressure shifted laterally with neutral fusion. The malalignments marginally affected the ROM but changed joint positions throughout stance phase. Pressure patterns were shifted laterally in varus malalignment and medially in valgus malalignment. The residual motion and the altered kinematics at the joints in the triple joint complex after TN fusion may subsequently increase the incidence of arthritis. Clinical significance: This study quantifies the effects of talonavicular fusion and malalignment on the other joints of the triple joint complex.

Müller-Weiss Disease: Midfoot Arthrodesis in Reduction vs Malreduction.

BACKGROUND: Midfoot arthrodesis is regarded as the main surgical approach for treating Müller-Weiss disease (MWD). This study aimed to investigate the incidence of postoperative pain during MWD treatment through midfoot reduction or malreduction during arthrodesis and to explore the factors influencing postoperative pain in patients with MWD. METHODS: A total of 67 patients with MWD were recruited and divided into two groups according to whether midfoot alignment was reduced: reduction group (n = 38) and malreduction group (n = 29). Demographic characteristics before the operation and at the last follow-up, as well as clinical and radiographic parameters, were compared between the two groups. Clinical parameters included the American Orthopaedic Foot & Ankle Society score and visual analog scale score, whereas radiographic parameters included the calcaneal pitch angle, lateral Meary's angle, talometatarsal-1 angle dorsoplantar (TMT1dp), talocalcaneal angle dorsoplantar (Kite angle), talonavicular coverage angle, and medial navicular pole extrusion. Postoperative complications and incidence of midfoot pain were evaluated at the last follow-up visit. RESULTS: The reduction group exhibited better clinical and radiological parameters, including the TMT1dp and medial navicular pole extrusion, than the malreduction group at the last follow-up (all P < .05). However, the calcaneal pitch angle, lateral Meary's angle, Kite angle, and talonavicular coverage angle did not significantly differ between the two groups (all P > .05). The overall incidence of midfoot pain was 26.4%. The reduction group showed a lower incidence of medial pain than the malreduction group (15.7% vs. 40.0%, P < .05). Regression analysis revealed that midfoot abduction, represented by the TMT1dp, was a critical factor for midfoot arthrodesis failure and that medial navicular pole extrusion was not correlated with postoperative midfoot pain. CONCLUSION: Midfoot reduction arthrodesis yields better clinical outcomes than malreduction arthrodesis. The TMT1dp, representing midfoot abduction, is a key factor for midfoot arthrodesis failure. The extruded medial navicular bone may not affect postoperative medial midfoot pain. LEVEL OF EVIDENCE: Level III, retrospective comparative study.