Achilles Tenotomy Research Articles

A case report of the successful use of regional anaesthesia and mixed sedative techniques in an adolescent with Duchenne muscular dystrophy

In this case report, we present a 12-year-old male who presented with clubbed feet for Achilles tenotomy with comorbid Duchenne muscular dystrophy and obesity. Owing to his prior surgical history and requirement for a prolonged intensive care unit stay with mechanical ventilation, we opted for a regional anaesthetic technique with mixed pharmacological and non-pharmacological sedation. The patient tolerated the nerve blocks with minimal sedation with midazolam and local anaesthesia and the surgery was performed successfully with light sedation and the help of his favourite song.

Peroneal Nerve Dysfunction in Patients with Clubfoot Deformity: Evaluation of Clinical Presentation and Treatment.

BackgroudComplete peroneal nerve dysfunction associated with congenital clubfoot is uncommonly reported. Our retrospective study highlights the recognition of clinical presentation and mid-term outcomes of treatment in these patients.MethodsEight out of 658 patients undergoing treatment for clubfoot were identified with unilateral complete peroneal nerve dysfunction associated with congenital clubfoot. Three patients presented primarily to our center; 5 were treated elsewhere initially. All patients were treated with Ponseti casts, Achilles tenotomy, and subsequent foot abduction bracing. Diagnosis of complete peroneal nerve dysfunction was confirmed using nerve conduction velocity studies in all patients. After full-time bracing, an insole polythene molded ankle foot orthosis was given. Three patients underwent tibialis posterior transfer to improve foot dorsiflexor power.ResultsThe mean age at presentation was 1.3 years (range, 1 week–5 years). All patients had prominence of lateral 3 metatarsal heads and dimpling of intermetatarsal spaces. At a mean follow-up of 5.1 years, mean shortening of 1.2 cm in tibia (range, 1–2.5 cm) and mean calf wasting of 4.4 cm were observed. There was no relapse of any clubfoot deformity till the final follow-up.ConclusionsProminence of lateral metatarsal heads and dimpling of intermetatarsal spaces should raise early suspicion of peroneal nerve dysfunction. Standard Ponseti protocol is useful in treatment of these patients. Tibialis posterior transfer to dorsum partially restores the ankle dorsiflexion.

Spironolactone Ameliorates Senescence and Calcification by Modulating Autophagy in Rat Tendon-Derived Stem Cells via the NF-κB/MAPK Pathway.

Tendinopathy is a disabling musculoskeletal disease, the pathological process of which is tightly associated with inflammation. Spironolactone (SP) has been widely used as a diuretic in clinical practice. Recently, SP has shown anti-inflammatory features in several diseases. Tendon-derived stem cells (TDSCs), a subset cell type from tendon tissue possessing clonogenic capacity, play a vital role in the pathological process of tendinopathy. In the present study, the protective effect of SP on TDSCs was demonstrated under simulated tendinopathy conditions both in vitro and in vivo. SP contributed to the maintenance of TDSC-specific genes or proteins, while suppressing the interleukin- (IL-) 1β-induced overexpression of inflammation-mediated factors. Additionally, IL-1β-induced cellular senescence in TDSCs was inhibited, while autophagy was enhanced, as determined via β-galactosidase activity, western blot (WB), and quantitative real-time polymerase chain reaction analysis. With the aid of several emerging bioinformatics tools, the mitogen-activated protein kinase (MAPK) pathway likely participated in the effect of SP, which was further validated through WB analysis and the use of MAPK agonist. Immunofluorescence analysis and an NF-κB agonist were used to confirm the inhibitory effect of SP on IL-1β-induced activation of the NF-κB pathway. X-ray, immunofluorescence, immunohistochemistry, hematoxylin and eosin staining, histological grades, and Masson staining showed that SP ameliorated tendinopathy in an Achilles tenotomy (AT) rat model in vivo. This work elucidates the protective role of SP on the pathological process of tendinopathy both in vitro and in vivo, indicating a potential therapeutic strategy for tendinopathy treatment.

Correction of clubfoot by ponseti method - Our experience

Background: Congenital idiopathic clubfoot is a complex deformity which occurs in an otherwise normal child. The Ponseti method of clubfoot management has been shown to be effective, producing better results and fewer complications than traditional surgical methods. Weekly manipulation and plaster casting reduce the deformity. Most feet also require a percutaneous Achilles tenotomy. The correction is maintained by a foot abduction brace (Dennis Browne splint). Recent studies suggest that the Ponseti method can be successful in up to 98% of feet. Objective: The purpose of this study was to assess the results of correction of idiopathic clubfoot by Ponseti method and its complications in children below 2 years of age. Methodology: It is a prospective study in 37 children below 2years of age with idiopathic clubfoot treated by Ponseti method. The study was conducted from august 2016 to august 2018 in Yashoda Superspeciality Hospital, Hyderabad. Observation and Analysis: The mean age of the patient’s was 35 weeks (0-120). Of 37 patients, 25 children presented between 0-6 months, 6 between 6 to 12 months and 6 between 1- 2 years. Among 37 children, 29 were male and 8 were female. Most children had grade III and grade IV (Dimeglio et al. grading) deformity. The average number of casts was 5.1, 5.5 and 7.4 for the age groups 0-6 months, 6 months to 1 year and 1-2 years respectively. The mean number of casts required was 5.76 (4 to 10). Tenotomy was required in 51 feet (100%). The scores for the entire group ranged from 4.0 to 7.0 (of 10) and 4 to 19 (of 20) in the Dimeglio classification. Pirani scores for the age group 0- 6 months were 4.46, 6 months to 1 year were 5.36 and 1-2 years were 5.75 respectively. The results were excellent in 88.3% and good in 11.7%.The mean of initial and final Pirani score is 3.52083 with a ‘ p’ value is 0.000 which is less than 0.01 hence they are statistically significant. Conclusion: Congenital talipes equinovarus (C.T.E.V) is the commonest of all the foot deformities being commoner in male children and bilateral in 66% of cases, idiopathic type being the commonest form. We conclude that the Ponseti method is safe and effective treatment for congenital idiopathic clubfoot in children up to 6 years of age.

Does malnutrition in clubfoot patients affect Ponseti technique and its outcome?

Malnutrition is a crucial health problem predominantly in the developing countries. Malnutrition in children is one of the main risk factors for diseases and mortality. Club foot or congenital talipes equinovarus (CTEV) is the most common form of congenital orthopaedic abnormality. Over the past 20years, the Ponseti method is considered the gold standard for the treatment of clubfoot. Our objective is to determine the prevalence of malnutrition in clubfoot patients, and its effects on the outcome of Ponseti technique in patients presenting to the Orthopaedic Clinic of tertiary care Hospital in Karachi, Pakistan. The cross-sectional study was conducted from January to December 2018. Total 153 clubfoot patients were treated and the World Health Organization (WHO) classification of weight-for-age index was used to assess the nutritional status of patients, and its impact on outcome of Ponseti technique was recorded and analysed with a P value≤.05 as significant. Of the 153 patients, 112 (79.7%) were found in good nutritional status and 42 (20.6%) were malnourished. The average number of casts per patient and patients requiring 6+casts in the undernutrition group was higher compared with good nutrition group (45.5% vs 21.42%, respectively). The number of Achilles tenotomy performed in the undernutrition group was also higher (76.4% vs 51.8%). A significant correlation between patients' nutritional status and outcome of the Ponseti technique is found as it influences the number of casts, possible relapse and failure of treatment.

Nesfatin-1 Promotes the Osteogenic Differentiation of Tendon-Derived Stem Cells and the Pathogenesis of Heterotopic Ossification in Rat Tendons via the mTOR Pathway.

Heterotopic ossification (HO) is a pathological condition involved in tendinopathy. Adipokines are known to play a key role in HO of tendinopathy. Nesfatin-1, an 82-amino acid adipokine is closely reportedly associated with diabetes mellitus (DM), which, in turn, is closely related to tendinopathy. In the present study, we aimed to investigate the effects of nesfatin-1 on the osteogenic differentiation of tendon-derived stem cells (TDSCs) and the pathogenesis of tendinopathy in rats. In vitro, TDSCs were incubated in osteogenic induction medium for 14 days with different nesfatin-1 concentration. In vivo, Sprague Dawley rats underwent Achilles tenotomy to evaluate the effect of nesfatin-1 on tendinopathy. Our results showed that the expression of nesfatin-1 expression in tendinopathy patients was significantly higher than that in healthy subjects. Nesfatin-1 affected the cytoskeleton and reduced the migration ability of TDSCs in vitro. Furthermore, nesfatin-1 inhibited the expression of Scx, Mkx, and Tnmd and promoted the expression of osteogenic genes, such as COL1a1, ALP, and RUNX2; these results suggested that nesfatin-1 inhibits cell migration, adversely impacts tendon phenotype, promotes osteogenic differentiation of TDSCs and the pathogenesis of HO in rat tendons. Moreover, we observed that nesfatin-1 suppressed autophagy and activated the mammalian target of rapamycin (mTOR) pathway both in vitro and in vivo. The suppression of the mTOR pathway alleviated nesfatin-1-induced HO development in rat tendons. Thus, nesfatin-1 promotes the osteogenic differentiation of TDSC and the pathogenesis of HO in rat tendons via the mTOR pathway; these findings highlight a new potential therapeutic target for tendinopathy.

Changes in the Management of Clubfoot Cases During COVID-19 Pandemic-A Survey Among Orthopaedic Specialists.

PurposeThe on-going COVID-19 pandemic has curtailed the established practice norms of many ailments including clubfoot. We conducted a survey to study the changes in the clubfoot treatment practices, Achilles tenotomy methods, and the role along with the possible impact of teleconsultation during this pandemic.MethodsA web-based survey was conducted using a questionnaire prepared on Google forms. The link for this questionnaire was sent to Indian Orthopaedic specialists with a special interest in clubfoot management via a social messaging platform.Results127 eligible responses were analysed. Of them, 67% respondents were in practice for more than 10 years. During the study period, 30.7% of doctors did not perform any casting; 66.9% performed casting in 1–5 cases per week and only 2.4% performed casting in more than five cases per week. A statistically significant difference was noted in the number of doctors who performed casting in less than five cases per week and the doctors who performed casting in more than five cases per week, before and during the COVID-19 pandemic. 30.7% of doctors deferred doing Achilles tenotomy during the study period, and among those who performed one, a significant number of them avoided tenotomy under general anaesthesia.ConclusionThe COVID-19 pandemic has significantly impacted clubfoot treatment practices during the lockdown period in India. Significant reductions in the number of cases, and a reduction with changes in Achilles tenotomy practices were noted too. However, whether this had any adverse influence on the eventual outcome in these feet is yet to be determined.Electronic supplementary materialThe online version of this article (10.1007/s43465-020-00277-2) contains supplementary material, which is available to authorized users.

Dimeglio's derotation of calcaneo pedal block and Pirani's talar head reduction: a quantitative matching.

We aimed to determine the quantitative value of derotation of calcaneo pedal block (DCPB) of Dimeglio system equivalent to talar head reduction of Pirani system. We also compared the ankle dorsiflexion obtained post tenotomy for different measures of DCPB. The study involved 53 idiopathic clubfoot children (86 feet) treated with Ponseti technique. Percutaneous Achilles tenotomy to correct ankle equinus was performed when forefoot adduction, heel varus were corrected and ankle dorsiflexion was <10°. Pirani's coverage of lateral head of talus was taken as a determinant of adequate DCPB and to perform tenotomy. Mean patient age at enrollment was 60.9 ± 71.1 days. The median pre and posttreatment Dimeglio scores were 13 (range 4-20) and 0 (range 0-3), respectively. DCPB at the time of talar head reduction was 53.8 ± 9.8°. In 85% feet, talar head reduction was obtained by DCPB 60° and all were reduced by 70°. The average ankle dorsiflexion improved significantly with DCPB ≥ 50°. The measure at which DCPB matched with talar head reduction of Pirani system was variable (40-70°). In all feet, talar head was reduced by 70° DCPB. Post tenotomy, ankle dorsiflexion was better with DCPB ≥ 50°.

Tranexamic acid has positive effect in early period of tendon healing by stimulating the tumor necrosis factor-alpha and matrix metalloproteinase-3 expression levels.

Objectives This study aims to evaluate the effect of tranexamic acid (TXA) application in tendon healing by using its immunohistochemical effects on tumor necrosis factor-alpha (TNF-α), matrix metalloproteinase-3 (MMP-3), and transforming growth factor-beta (TGF-β) expression; and to identify if TNF-α, MMP-3, and TGF-β can be used to monitor and evaluate tendon healing or not in tenotomized rat Achilles tendons.Materials and methods Twelve male Wistar-Albino rats (age 6-7-month-old; weighing 300-350 g) were used in this retrospective study conducted between November 2016 and May 2017. The rats were divided into two groups with similar weights. The right legs of the rats were determined as the study group (TXA), and the left legs as the control serum physiologic (SP) group. Under anesthesia, bilateral Achilles tenotomy was performed and surgically repaired. 1 mL of TXA was applied locally for the right side and 1 mL of SP was locally applied for the left side. Half of the rats were sacrificed at the third week (right leg-TXA3, left leg-SP3) and the other half at sixth week (right leg-TXA6, left leg-SP6) and tendon samples were taken from the extremities. Immunohistochemical findings of TNF-α, MMP-3, and TGF-β were evaluated on the basis of the frequency and intensity of staining. Results In TNF-α and MMP-3 and TXA groups, there was a significant difference in staining compared to SP groups (p<0.05). Regarding TNF-α expression, the total index score in the TXA6 subgroup was higher than the TXA3, SP6, and SP3 subgroups (8, 7, 3, and 4, respectively). Overall scores of TNF-α showed that TXA groups had significantly higher scores when compared to SP groups (p<0.05). In addition, total MMP-3 expression scores were significantly higher in TXA groups than in SP groups, respectively; TXA3: 14, TXA6: 11, SP3: 10, and SP6: 9 (p<0.05). However, the degree of staining with TNF-α was found to be significantly lower than MMP-3 (p<0.05). Immunohistochemical reactivity was not observed with TGF-β.ConclusionTranexamic acid has positive effect in early period of tendon healing by stimulating the TNF-α and MMP-3 expression levels. TNF-α and MMP-3 can be used to monitor and evaluate tendon healing.

Cross Sectional Study of Clinical Profile and Treatment of Clubfoot by Ponseti Method among Infants at a Tertiary Care Hospital

Congenital Talipes Equinovarus (clubfoot) is the most common abnormality of foot. Mostly, clubfoot is idiopathic but various environmental and epidemiological factors have influenced the etiology of it. The aim of study was to access clinical profile and efficacy of Ponseti method of treatment in infants. Methodology: It is a cross-sectional study conducted at orthopedic department, Nishtar medical university and hospital, Multan. Duration of study was 3 years, from 10th January 2016 to 10th January 2019. We included 58 (88 clubfeet) infants with age ranges from 2-12 months. Patients suffering from Arthrogryposis multiplex congenita, Meningomyelocele, spina bifida and had past surgical manipulation were excluded. Results: There were 68.9% male and 31% female patients in our study. There were Bilateral 30 (51.7%) children with bilateral TEV while 28 (48.3%) patients with unilateral clubfoot. In our study, 70 percent of the feet were corrected with six serial casting. Achilles tenotomy was needed in 68 (77.2%) feet. We observed pre-treatment Pirani score 5.51 ± 0.62 while post treatment Pirani score was E‚0.5. Excellent outcome was reported in 80 (91%) while remaining 9% left the treatment and didn’t come for follow up. After evaluating birth history we found that 40 (68%) patients were born through spontaneous vertex delivery, 8 (13.7%) needed Caesarian section and 10 (17%) needed episiotomy to facilitate their births. In fifty (56.8%) patients the calf muscles were normal and among 38 (43.1%) were thin. There was no major complication noted. Conclusion: Clubfoot among male is more common than female. There were equal number of cases with bilateral and unilateral clubfoot. Mode of delivery and positive family history had significant association with clubfoot. Patients with early presentation and low pretreatment Pirani score showed excellent outcome as compare to patient presented with high Pirani scoring. Ponseti technique showed excellent outcome in majority of patients in our study. Effective awareness campaigns and counselling of parents can show good compliance to treatment. Training of primary and secondary healthcare professionals should be done in order to calvefacilitate people and share burden of tertiary care hospitals.

Clubfoot treatment with Ponseti method\u2014parental distress during plaster casting

BackgroundClubfoot is one of the most prevalent musculoskeletal congenital defects. Gold standard treatment of idiopathic clubfoot is the conservative Ponseti method, including the reduction of deformity with weekly serial plaster casting and percutaneous Achilles tenotomy. It is well known that parents of children with severe and chronic illnesses are mentally stressed, but in recent studies regarding clubfoot treatment, parents were only asked about their satisfaction with the treatment. Largely unknown is parental distress before and during plaster casting in clubfoot.Therefore, we want to determinate first, how pronounced the parents’ worries are before treatment and if they decrease during the therapy. Second, we hypothesized that parents faced with an extreme deformity (high Pirani score), reveal more distress, than parents whose children have a less pronounced deformity (low Pirani score). Therefore, we wanted to investigate whether the Pirani score correlates with the parents’ mental resilience in relation to the therapy of the child as a global distress parameter.MethodsTo answer this question, we developed a questionnaire with the following emphases: Physical capacity, mental resilience, motion score, parents score, and child score with point scores 1 (not affected) to 6 (high affected). Subsequently, we interviewed 20 parents whose children were treated with clubfeet and determined the Pirani score of the infants at the beginning (T0) and at the end (TE) of the treatment with plaster casting.ResultsHigh values were obtained in child score (Mean (M) = 3.11), motion score (M = 2.63), and mental resilience (M = 2.25). During treatment, mental resilience improved (p = 0.015) significantly. Spearman correlation coefficient between Pirani score (T0) and mental resilience (T0) is 0.21, so the initial hypothesis had to be rejected.ConclusionThe issues of the children are in the focus of parental worries concerning clubfoot treatment, especially the assumed future motion and the assumed ability to play with other children. Particular emphasis should be placed on educating parents about the excellent long-term results in the function of the treated feet especially as this topic shows the greatest parental distress.

The Ponseti method of treatment for neuromuscular and syndromic (non-idiopathic) clubfeet: evaluation of a programme-based approach at a mean follow-up of 5.8years.

To analyse the results of the Ponseti method in the treatment of non-idiopathic clubfeet and compare them with idiopathic clubfeet in a programme-based setting using a standardized protocol METHODS: We reviewed two groups of 782 children treated prospectively in our programme-based Clubfoot Clinic: group I comprised of 89 patients (146 feet) with non-idiopathic clubfoot and group II comprised of 693 patients (1032 feet) with idiopathic clubfoot. Both groups were compared on the basis of patient demographics, number of casts, tenotomy rate, success rate, rate of recurrences, and the need for additional secondary procedures. Non-idiopathic clubfeet had a higher incidence of bilateral involvement (p = 0.0093) and affected both males and females equally (p = 0.002) as compared with idiopathic clubfeet. Non-idiopathic clubfeet (group I) required significantly more casts (6.75 ± 4.2) compared with idiopathic clubfeet (4.23 ± 4.14), had a higher rate of Achilles tenotomy (90.4% vs 75%, p < 0.0001), and had a lower initial correction rate compared with idiopathic clubfeet (92.5% vs 100%, p < 0.0001). There was a significant difference in the recurrence rates between the two groups, as 42.5% of non-idiopathic feet (38 patients) relapsed compared with 10.2% (71 patients) in the idiopathic group (p < 0.0001). Most recurrences in group I were amenable to re-casting, with only nine patients (14 non-idiopathic clubfeet) requiring extensive soft tissue releases. The final success rate in the non-idiopathic group at a mean follow-up of 5.8years (2-8years) was 87.7%. We recommend the use of the Ponseti method as an effective treatment for non-idiopathic clubfeet associated with neuromuscular and syndromic conditions.

Effect of Achilles tendon on kinematic coupling relationship between tarsal bones: a pilot finite element study

BackgroundThe procedure of percutaneous Achilles tenotomy (PAT) is an important component of the Ponseti method. However, few studies reported the influence of Achilles tendon on kinematic coupling relationship between tarsal bones. The purpose of present study was to demonstrate the effect of Achilles tendon on the kinematic coupling relationship between tarsal bones, and to illustrate how kinematic coupling relationship between tarsal bones works in term of finite element analysis.MethodsA three-dimensional finite element model of foot and ankle was constructed based on the Chinese digital human girl No.1 (CDH-G1) image database using the software of mimics, Geomagic studio, HyperMesh, and Abaqus. The last manipulation of the Ponseti method before the procedure of PAT was simulated. The talus head and the proximal tibia and fibula bone were fixed in all six degrees of freedom, and the outward pressure was added on the first metatarsal head to investigate the kinematic coupling relationship between tarsal bones.ResultsThe least relationship of kinematic coupling between tarsal bones was found in calcaneus. Stress concentration was mainly observed at the navicular, talus and the medial malleolus. The difference in displacement of the navicular was only found with the Achilles tendon stiffness of 0 N/mm and others. No difference in the navicular displacement was found in the stiffness of Achilles tendon between 40, 80, 200, 400, and 1000 N/mm. The maximum displacement of navicular was observed at the ankle position of PF-20° (plantar flexion-20°). The difference in displacement of the navicular was greater at the ankle position of PF-20° with the Achilles tendon stiffness of 0 N/mm than that at the ankle position of PF-40° with the Achilles tendon stiffness of 40 N/mm.ConclusionsBased on the findings from this study, it was demonstrated that the Achilles tendon existence or not and ankle position had great influence, while increased stiffness of Achilles tendon had no influence on kinematic coupling relationship between tarsal bones. For the cases with severe equinus, earlier implementation of PAT procedure (with the purpose of release the Achilles tendon and reduce the degree of ankle plantar flexion) may be beneficial to the deformity correction.

Interventions for congenital talipes equinovarus (clubfoot).

Interventions for congenital talipes equinovarus (clubfoot).

Macrophage-derived neurotrophin-3 promotes heterotopic ossification in rats

AbstractHeterotopic ossification (HO) is a debilitating condition that results from traumatic injuries or genetic diseases, for which the underlying mechanisms remain unclear. Recently, we have demonstrated the expression of neurotrophin-3 (NT-3) and its role in promoting HO formation via mediating endothelial–mesenchymal transition (EndMT) of vascular endothelial cells. The current study investigated the role of NT-3 on the surrounding mesenchymal cells and its potential origin throughout HO formation at injured Achilles tendons in rats. We used an Achilles tenotomy to induce HO formation in vivo and cultured primary tendon-derived stem cells (TDSCs) to investigate the underlying mechanisms mediating the osteogenesis in vitro. Furthermore, RAW264.7 cells were employed to identify the origin of NT-3. The mRNA levels of NGF, BDNF, NT-3, and NT-4 and their tyrosine protein kinase (Trk) receptors as well as p75 receptor were elevated at injury sites. NT-3 and TrkC showed the highest induction. Neutralization of the NT-3-induced effects by the pan-Trk inhibitor GNF5837 reduced the expression of bone/cartilage-related genes while injection of NT-3 promoted HO formation with elevated mRNA of bone/cartilage-related markers at injured sites. In vitro, NT-3 accelerated osteogenic differentiation and mineralization of TDSCs through activation of the ERK1/2 and PI3K/Akt signaling pathways. Moreover, the colocalization of NT-3 and macrophages, including M1 and M2 macrophages, was observed in injured sites throughout HO formation, and in vitro studies demonstrated that activated macrophages mediated the secretion of NT-3. In addition, an increasing concentration of serum or supernatant NT-3 was observed both in vivo and in vitro. Depletion of macrophages with clodronate-loaded liposomes reduced HO formation as well as secretion and mRNA expression of NT-3. Our study suggests that macrophage-derived NT-3 may promote HO formation and osteogenesis of TDSCs via the ERK1/2 and PI3K/Akt signaling pathways, which may provide new insights for the therapeutic directions of HO in the future.

The Influence of Achilles Tenotomy and Compliance with Foot Abduction Orthosis on the Relapse Rate of Ponseti Treatment for Idiopathic Clubfoot: A Regional Study

The Ponseti method for treating idiopathic clubfoot is based on gradual manipulations and corrective plaster castings followed by a years-long period of use of a foot orthosis. The role of surgery is limited. The factors that may affect outcome and their influence are subject of controversy. The aim of the study is to systematically and objectively evaluate the results of Ponseti treatment in our region of Southern Israel and focus on the role of the Achilles tenotomy and compliance to foot orthosis as factors that may influence outcome. The use of Ponseti method was retrospectively studied (level of evidence IV) by searching computerized medical files and clinical photos. The severity of deformity was evaluated by Dimeglio score (D-score) at baseline and at last examination. During 2006-2014, 57 children with idiopathic clubfoot (total 90 feet) were enrolled. An Achilles tenotomy was performed in 55/90 (61.1%) of the feet. If the D-score was 15 or higher there was a 20% increase in the incidence of Achilles tenotomy. The parental compliance had a weak protective effect against relapse. The treatment of idiopathic clubfoot by the Ponseti method was successful and reliable, proving efficiency and universality of the method. A dominant predictor for relapse was not seen. An incidental observation was that extended time in cast may buffer the adverse effects of low compliance rate. Although the initial severity, or compliance to braces are important, there may be other factors that affect the outcome such as, accuracy of the casting technique, time in the cast, access to a dedicated clubfoot clinic, cooperation with nurses and pediatricians, economic status that allows purchase of new generation of braces, cultural perception, and education level of the patient population are some examples.

Abstract 40: Post-Traumatic Limb Immobilization Alters Mesenchymal Stem Cell Fate

Purpose: Traumatic heterotopic ossification (HO) is a debilitating condition where aberrant bone is formed outside the skeleton due to a fate switch of tissue resident mesenchymal/progenitor cells (MSCs). HO can occur after extremity trauma, burns, and extremity surgeries including amputations and joint replacements. No effective preventive strategies exist as the underlying mechanisms have not been elucidated. Though HO forms at sites of mechanical stress, the role of joint mobilization during extremity trauma, healing, and HO formation has not been clearly defined. We hypothesize that movement is central to HO formation via mechanotransductive signaling, and can provide a basis for improving post-trauma guidelines to prevent HO. Methods: HO was induced in mice via a dorsal partial thickness burn with concomitant Achilles tenotomy (B/T). Single cell RNA (scRNA) sequencing was performed prior to injury and on 3, 7, and 21 days post-B/T tissue using 10X genomics and downstream analysis with Seurat R package. scRNA sequencing was performed on immobilized mice 7 days post B/T and compared to that of mobile mice at the same time point. Scores were generated for each cell based on correlations with either osteogenic or adipogenic gene signatures in MSCs from mobile or immobilized mice. B/T was performed in mice of 4 groups (n=3/group): forced run, exercised passive range of motion (ROM), ambulated normally (mobile), or immobilized, and hindlimb bone volume was assessed at 9 weeks post-B/T by MicroCT (uCT). Immunofluorescent (IF) labeling for PDGFRα and pFAK, TAZ, or Perilipin-1 was done on 1 week cross sections and quantified (n=3/group). Results: Single cell clustering showed there are 15 unique clusters, 3 of which are MSC populations with increased expression of mechanotransductive markers such as Ptk2 (FAK), Yap1 (YAP) and Wwtr1 (TAZ). Joint immobilization of the ankle completely inhibited HO formation, therefore, the comparison of mobile and immobile mice was explored. Histology of immobilized mice demonstrated there is decreased mechanotransductive signaling (pFAK and nuclear TAZ) compared to mobile group. Interestingly, we noted increased adipocytes in the immobilized group at 1 week. Comparing scRNA sequencing revealed that MSCs (clusters 2, 3, and 14) from immobile mice correlated with an adipogenic signature compared to mobile MSCs that favored osteogenesis. This finding suggests a cell fate shift towards adipogenesis with joint immobilization. Conclusion: Hindlimb immobilization plays a significant role altering mechanotransductive pathways which we demonstrate results in an shift in MSC differentiation programming from endochondral ossification to adipogenesis. Immobilization protocols should be considered in patients at high HO risk.

Desloratadine inhibits heterotopic ossification by suppression of BMP2-Smad1/5/8 signaling.

Heterotopic ossification (HO) is a pathological condition in which ectopic bone forms within soft tissues such as skeletal muscle. Human platelet-derived growth factor receptor α positive (PDGFRα+) cells, which were proved to be the original cells of HO were incubated in osteogenic differentiation medium with Food and Drug Administration-approved compounds. Alkaline phosphatase activity was measured as a screening to inhibit osteogenic differentiation. For the compounds which inhibited osteogenic differentiation of PDGFRα+ cells, we examined dose dependency of its effect using alizarin red S staining and its cell toxicity using WST-8. In addition, regulation of bone morphogenetic proteins (BMP)-Smad signaling which is the major signal of osteogenic differentiation was investigated by Western blotting to elucidate the mechanism of osteogenesis inhibitory effect by the compound. In vivo experiment, complete transverse incision of Achilles tendons in mice was made and mice were fed the compound by mixing with drinking water after operation. Ten weeks after operation, we assessed and quantified HO by micro-computed tomography scan. Intriguingly, we discovered desloratadine inhibited osteogenic differentiation of PDGFRα+ cells using the drug repositioning method. Desloratadine inhibited osteogenic differentiation of the cells dose dependently without cell toxicity. Desloratadine suppressed phosphorylation of Smad1/5/8 induced by BMP2 in PDGFRα+ cells. In Achilles tenotomy mice model, desloratadine treatment significantly inhibited ectopic bone formation compared with control. In conclusion, we discovered desloratadine inhibited osteogenic differentiation using human PDGFRα+ cells and proved its efficacy using Achilles tenotomy ectopic bone formation model in vivo. Our study paved the way to inhibit HO in early clinical use because of its guaranteed safety.

Adaptive and innate immune cell responses in tendons and lymph nodes after tendon injury and repair.

Tendon injuries are a common clinical condition with limited treatment options. The cellular components of the innate immune system, such as neutrophils and macrophages, have been studied in tendon injuries. However, the adaptive immune system, comprising specialized lymphocytes, plays an important role in orchestrating the healing of numerous tissues, but less is known about these cells in tendon healing. To gain a greater understanding of the biological processes that regulate tendon healing, we determined how the cellular components of the adaptive and innate immune system respond to a tendon injury using two-month-old male mice. We observed that lymphatic vasculature is present in the epitenon and superficial regions of Achilles tendons, and that the lymphatics drain into the popliteal lymph node. We then created an acute Achilles tenotomy followed by repair, and collected tendons and popliteal lymph nodes 1, 2, and 4 wk after injury. Tendon injury resulted in a robust adaptive immune cell response that followed an initial innate immune cell response in tendons and lymph nodes. Monocytes, neutrophils, and macrophages initially accumulated at 1 wk after injury in tendons, while dendritic cells and CD4+ T cells peaked at 2 wk after injury. B cells and CD8+ T cells progressively increased over time. In parallel, immune cells of the popliteal lymph node demonstrated a similarly coordinated response to the injury. These results suggest that there is an adaptive immune response to tendon injury, and adaptive immune cells may play a role in regulating tendon healing.NEW & NOTEWORTHY While the innate immune system, consisting of macrophages and related hematopoietic cells, has been studied in tendon injury, less is known about the adaptive immune system. Using a mouse model of Achilles tendon tenotomy and repair, we observed an adaptive immune cell response, consisting of CD4+ and CD8+ T cells, and B cells, which occur through 4 wk after tendon injury. This response appeared to be coordinated by the draining popliteal lymph node.

Confirmation of Tenotomy Healing at 3 Weeks Using the Ponseti Protocol

Percutaneous Achilles tenotomy is an integral key element of the Ponseti method in clubfoot management. The duration of posttenotomy casting has been empirical. Evidence-based duration of healing in Achilles tendon is required to objectively determine the period of posttenotomy casting. This study aims to use clinical and ultrasonographic methods to evaluate the mean duration of Achilles tendon gap (ATG) closure and the weekly percentage of feet that achieved ATG closure after tenotomy. Prospectively, 37 feet of 25 patients <5 years old with idiopathic clubfoot were managed using Ponseti methods. The Achilles tendon was assessed clinically and ultrasonographically before and after tenotomy. The tendon stump gap was created at tenotomy, and posttenotomy assessments were done on a weekly basis until tendon stump gap closure was achieved, with a minimum follow-up of 2 years. The immediate posttenotomy ultrasonographic mean tendon gap area was 5 ± 2.8 mm. The mean duration of the tendon stump gap closure as determined clinically was 1.9 ± 0.8 weeks, whereas it was 2.6 ± 0.9 weeks as assessed ultrasonographically (p < .001). The significant difference between clinical and ultrasound methods of assessing the Achilles tendon gap closure appears to establish casting removal and ambulatory walking at 3 weeks after tenotomy for <5-year-old children with idiopathic clubfoot treated with the Ponseti method. We recommend that the duration of posttenotomy cast should be 3 weeks based on the ultrasonographic findings.