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BACKGROUND: Up to one-third of children with cerebral palsy (CP) develop migration of the hip, and the risk increases with a higher Gross Motor Function Classification System (GMFCS). In progressive hip migration in young children, adductor tenotomy is an accepted treatment option to delay or prevent progressive hip migration. However, there is quite a large variability in reported results. This systematic review aims to determine the effectiveness of a soft-tissue release in the prevention of progressive hip migration in children with CP. METHODS: This systematic review was performed in accordance with the guidelines of the Cochrane Handbook for Systematic Reviews and the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols statements. Our inclusion criteria were studies describing pediatric, skeletally immature patients with CP and a "hip at risk" of progressive hip migration. Exclusion criteria were simultaneous bony reconstructions, case reports, technical notes, published abstracts, or studies with a follow-up under 1 year postoperatively. The primary outcomes were defined as failure rate (progressive hip migration and/or need for bony surgery, as defined by each paper) and change in migration percentage (MP) at final follow-up. As secondary analyses, we evaluated the outcome after specific subtypes of surgeries and assessed whether performing lengthening of iliopsoas, neurectomy of the anterior branch of the obturator nerve, age at the time of surgery, GMFCS level, and postoperative management impact the outcome. RESULTS: Our literature search identified 380 titles. Eighty-four articles underwent full-text review, of which 27 met our inclusion/exclusion criteria and were subsequently selected for quantitative analysis. A prevalence meta-analysis was performed including 17 studies (2,213 hips). Mean follow-up ranged from 12 to 148.8 months. The mean preoperative MP was 33.4% (2,740 hips) and 29.9% at follow-up. The overall reported failure rate was 39% (95% confidence interval, 26%-52%). Performing a release of only adductor longus had a failure rate of 87%, whereas more extensive soft-tissue releases showed significantly better results with failure rates ranging from 0 to 44% (p < 0.001). Lengthening of the iliopsoas had no significant impact on failure rate (p = 0.48), nor did performing an obturator neurectomy (p = 0.92). CONCLUSION: The failure rate of adductor tenotomies to prevent progressive hip migration appears to be as high as 39% in studies with a varying follow-up. The failure rates are significantly higher when isolated release of the adductor longus is performed. This systematic review supports clinical decision making in children with CP and early hip migration. LEVEL OF EVIDENCE: Level IIA. See Instructions for Authors for a complete description of levels of evidence.

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BACKGROUND: Lateral epicondylitis is a common cause of elbow pain that is generally self-limiting. For patients who have persistent symptoms refractory to conservative treatment, there is still no clear consensus on the most favorable treatment modality. The purpose of this systematic review was to synthesize the available literature regarding both nonoperative and operative treatment modalities for recalcitrant lateral epicondylitis (RLE) to provide insight into the efficacy of treatment options. METHODS: A systematic review was performed in accordance with the 2020 Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines, where the PubMed, MEDLINE/Ovid, CINAHL, Cochrane, and Scopus databases were queried to identify studies evaluating treatment options for RLE. RESULTS: A total of 27 studies with 1,958 patients were included. Of the reviewed studies, there were a wide variety of treatments including platelet-rich plasma injections, percutaneous tenotomies, and various arthroscopic and open procedures. CONCLUSION: There are a wide variety of treatment modalities available for RLE that have promising efficacy in the short, medium, and long terms. A comprehensive approach combining evidence-based and patient-centered care is critical for effective management of refractory symptoms. LEVEL OF EVIDENCE: Level IV. See Instructions for Authors for a complete description of levels of evidence.

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BACKGROUND: Hip replacement surgery is highly effective in relieving pain and improving mobility in patients with various hip conditions. However, some patients develop groin pain after surgery, often due to iliopsoas impingement (IPI), which can be challenging to diagnose. Conservative treatments are initially recommended, but when these are not effective, surgical options may be considered. This study aims to evaluate the clinical outcomes, success and failure rates, revision rates, and complications associated with arthroscopic and endoscopic surgery for IPI, thereby providing a comprehensive understanding of the effectiveness and risks of these surgical interventions. MATERIALS AND METHODS: A systematic review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, including a thorough search of five main databases: PubMed, Scopus, Embase, Medline, and Cochrane. Eligible articles were meticulously evaluated according to predefined criteria for levels of evidence (LoE), with retrospective studies assessed using the Coleman Methodology Score (mCMS). This systematic review was registered in the International Prospective Registry of Systematic Reviews (PROSPERO). RESULTS: Among the 16 included studies, 431 patients with 434 hips underwent either endoscopic or arthroscopic tenotomy. Both techniques showed favorable outcomes, with arthroscopic tenotomy demonstrating slightly higher success rates than endoscopic tenotomy. Common complications included mild pain and occasional infections, with recurrence observed in some cases. Both techniques offer direct visualization of prosthetic components and potential preservation of psoas function. CONCLUSIONS: Arthroscopic and endoscopic iliopsoas tenotomy are effective treatments for alleviating symptoms and improving hip function in patients with IPI post-total hip arthroplasty (THA). LEVEL OF EVIDENCE: IV.

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BACKGROUND: Congenital talipes equinovarus, or clubfoot, can lead to lifelong functional impairments, including diminished gross motor skills (GMS), if left untreated. The Ponseti method corrects idiopathic clubfoot through casting and bracing. Given the importance of GMS in childhood development, this technique must be optimized to support childhood and long-term health outcomes. This study examined immediate posttreatment GMS in 3-year-old children treated with Ponseti, hypothesizing that they would perform on par with their nonclubfoot peers. METHODS: Data from 45 children (33 to 46 mo of age) treated for idiopathic clubfoot were analyzed. The Peabody Developmental Motor Scales, 2nd edition, was used to assess GMS, and logistic regression identified factors influencing Gross Motor Quotient (GMQ) scores. RESULTS: Approximately half (n=22) of the patients exhibited below-average GMS (11th to 25th percentile), with 11 scoring below the 10th percentile. Initial deformity severity, gender, and cast numbers did not impact GMQ. Repeat percutaneous tenotomy was associated with lower GMQs. Brace compliance significantly reduced odds of low GMQs by up to 80%. Age at testing and additional surgery were also linked to below-average and poor GMQs. CONCLUSIONS: GMS appeared to be impaired in almost half of the 3-year-old patients treated for idiopathic clubfoot, so our hypothesis was disproven. Repeat percutaneous tenotomy was associated with lower GMS, necessitating future recognition of patients who might be at risk of relapse. Brace noncompliance emerged as a significant risk factor, emphasizing early identification of these patients and education for their parents. This study offers a benchmark for clinicians and parents, but research on long-term outcomes is needed. LEVEL OF EVIDENCE: Level II, prospective cohort study.

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CASE: We present a 67-year-old woman with long finger extrinsic extensor tightness and a 56-year-old man with limited index finger flexion due to extrinsic extensor tightness secondary to tendon transfers for radial nerve palsy. Both patients underwent prior surgical procedures that led to limited range of motion (ROM). Subsequently, they elected for central tendon tenotomy (CTT), which demonstrated postoperative ROM improvement and satisfactory patient outcomes. CONCLUSION: Surgical management of extrinsic extensor tendon tightness of the hand is generally addressed by performing tenolysis to improve tendon excursion. We present a novel and simple technique of CTT with pertinent anatomy, descriptive cases, and a cadaveric video.

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Aims: The gold standard for percutaneous Achilles tendon tenotomy during the Ponseti treatment for idiopathic clubfoot is a tenotomy with a No. 15 blade. This trial aims to establish the technique where the tenotomy is performed with a large-bore needle as noninferior to the gold standard. Methods: We randomized feet from children aged below 36 months with idiopathic clubfoot on a 1:1 basis in either the blade or needle group. Follow-up was conducted at three weeks and three months postoperatively, where dorsiflexion range, Pirani scores, and complications were recorded. The noninferiority margin was set at 4° difference in dorsiflexion range at three months postoperatively. Results: The blade group had more dorsiflexion at both follow-up consultations: 18.36° versus 18.03° (p = 0.115) at three weeks and 18.96° versus 18.26° (p = 0.001) at three months. The difference of the mean at three months 0.7° is well below the noninferiority margin of 4°. There was no significant difference in Pirani scores. The blade group had more extensive scar marks at three months than the needle group (8 vs 2). No major complications were recorded. Conclusion: The needle tenotomy is noninferior to the blade tenotomy for usage in Ponseti treatment for idiopathic clubfoot in children aged below 36 months.

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CASE: Traumatic pediatric Achilles ruptures are rare, and few cases have been reported among patients with a history of Achilles tenotomy. A 17-year-old boy with a history of Achilles tenotomies for congenital clubfoot as an infant presented with acute midsubstance Achilles tendon rupture of the right leg. The gastrocnemius fascia was dissected to allow for approximation of the ruptured Achilles tendon segments. Furthermore, the plantaris tendon was harvested and sutured around the Achilles tendon-rupture site to improve strength. CONCLUSIONS: Patients with a history of clubfoot and chronic Achilles tendon pain should be alerted to the risk of Achilles tendon rupture.

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PURPOSE: The objective of this study was to evaluate the functional outcome during follow-up (FU) after endoscopic tenotomy for iliopsoas (IP)-cup impingement and to quantitatively analyze the hip flexion strength. METHODS: This was a monocentric, retrospective cohort study of a single surgeon series. Functional assessment was based on the modified Harris score, the Oxford score and the visual analog scale score. Strength was measured with a handheld dynamometer in the sitting and lying position. RESULTS: Thirty-six IP tenotomies for cup impingement were performed between May 2013 and November 2021. Seven (19%) patients were lost to FU. At the time of tenotomy, the mean (standard deviation) age was 62,6 (12,2) and BMI was 26,5 (4,1). The mean FU time after tenotomy to the last FU was 3,6 (0,8) years. All three outcome scores improved from preoperatively to six months postoperatively (p < 0.001). There were no significant change from six months to last FU. The minimal clinically important difference (MCID) of the modified Harris score was set at 25. 20 (69%) patients had values that exceeded the threshold at one month and six months and neutral 19 (65.5%) had values that exceeded the threshold at the last FU. The limp symmetry index concerning hip flexion strength was 63% at 90° and 40% at 30° at the last FU. CONCLUSION: Most patients significantly improved their outcome scores after endoscopic iliopsoas tenotomy, with results remaining consistently stable over time. Despite a significant loss in hip flexion strength, the majority of patients did not report any impairment of their quality of life. STUDY DESIGN: Level III, Retrospective cohort study.

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BACKGROUND: Snapping hip syndrome (SHS) is characterized by snapping sensation and pain and affects up to 10% of the general population. External snapping hip syndrome (ESHS), the most common form, is often due to repetitive movements in sports or anatomical predispositions. Conservative treatment includes physiotherapy and corticosteroid injections, while surgery is considered if conservative measures fail. Open surgical techniques carry several risks, while modern arthroscopic techniques offer less invasive options, such as endoscopic iliotibial band release (ITB) and gluteus maximus tenotomy. MATERIALS AND METHODS: A systematic review was conducted adhering to the PRISMA guidelines. Relevant studies were searched in four databases: Pubmed, Scopus, Embase, and Medline. The selected articles were evaluated according to the criteria of levels of evidence. The Risk of Bias In Non-randomized Studies of Interventions (ROBINS-I) was used to analyze the retrospective studies. This paper was registered in the International Prospective Registry of Systematic Reviews (PROSPERO). RESULTS: Out of 9 included studies, 403 patients with 689 hips underwent endoscopic treatment. ITB release and his variations were the main surgical techniques. Gluteus maximus tenotomy was also used in some studies. Postoperative rehabilitation protocols varied. Patients generally experienced significant improvements in symptoms and functional outcomes, with low rates of recurrence (1.02%) and revision (0.15%). Complications were minimal. CONCLUSIONS: Endoscopic treatment of ESH shows favorable results, improving functional outcomes and returning patients to pre-injury activity levels. Long-term efficacy and costeffectiveness need to be evaluated, emphasizing the importance of large-scale prospective randomized trials to clarify surgery's benefits in refractory ESH cases.

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ABSTRACT: Achilles tendinopathy is a common overuse injury that is traditionally managed with activity modification and a progressive eccentric strengthening program. This narrative review describes the available evidence for adjunctive procedural interventions in the management of midportion and insertional AT, specifically in the athletic population. Safety and efficacy data from available literature on extracorporeal shockwave therapy, platelet-rich plasma, high-volume injectate with or without tendon scraping, and percutaneous needle tenotomy are used to propose an algorithm for treatment of Achilles tendinopathy for the in-season athlete.

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Aims: There is a lack of high-quality research investigating outcomes of Ponseti-treated idiopathic clubfeet and correlation with relapse. This study assessed clinical and quality of life (QoL) outcomes using a standardized core outcome set (COS), comparing children with and without relapse. Methods: A total of 11 international centres participated in this institutional review board-approved observational study. Data including demographics, information regarding presentation, treatment, and details of subsequent relapse and management were collected between 1 June 2022 and 30 June 2023 from consecutive clinic patients who had a minimum five-year follow-up. The clubfoot COS incorporating 31 parameters was used. A regression model assessed relationships between baseline variables and outcomes (clinical/QoL). Results: Overall, 293 patients (432 feet) with a median age of 89 months (interquartile range 72 to 113) were included. The relapse rate was 37%, with repeated relapse in 14%. Treatment considered a standard part of the Ponseti journey (recasting, repeat tenotomy, and tibialis anterior tendon transfer) was performed in 35% of cases, with soft-tissue release and osteotomies in 5% and 2% of cases, respectively. Predictors of relapse included duration of follow-up, higher initial Pirani score, and poor Evertor muscle activity. Relapse was associated with poorer outcomes. Conclusion: This is the first multicentre study using a standardized COS following clubfoot treatment. It distinguishes patients with and without relapse in terms of clinical outcomes and QoL, with poorer outcomes in the relapse group. This tool allows comparison of treatment methods and outcomes, facilitates information sharing, and sets family expectations. Predictors of relapse encourage us to create appropriate treatment pathways to reduce relapse and improve outcome.

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Ultrasound (US) can guide and confirm percutaneous release of the achilles tendon in the clubfoot. However, this technique may not always be available; therefore, surgeons' reported feelings of tendon release ("click" or "pop") and the Thompson sign could demonstrate that they are sensitive and reliable for confirming complete tendon release. The purpose of this study was to compare the reproducibility of clinical maneuvers that aim to detect the reported "click" or "pop" sensation by the surgeon and the Thompson sign after surgical release in percutaneous achilles tenotomy compare with US in patients with clubfoot. A cross-sectional reproducibility study of consecutive patients with idiopathic clubfoot was conducted. All the patients were scheduled to undergo tenotomy in the operating room using the standard percutaneous achilles tenotomy technique under sedation. The surgeon's reported surgical sensation ("click" or "pop") and Thompson signs were compared to the US assessment of the cut. The final Pirani score was used to predict recurrence risk and was correlated with the number of plaster casts and age. Forty-five feet were affected in 30 patients. Eighteen (60%) men. Age range: 1 to 60 months. The sensation of "click" or "pop" was recorded in 38 patients, and complete release was confirmed by US in 37 patients, for a sensitivity (Se) of 0.95 and specificity (Sp) of 0.63. Thompson signs were positive in 33 and 36 patients at 2 evaluations, with Se values of 0.87 and 0.92 and Sp values of 0.88 and 0.75, respectively. The Pirani final score, a predictor of recurrence risk, had an area under the curve of 0.80 (95% CI = 0.63-0.97; P = .005), Se = 0.78, and Sp = 0.56, with a cutoff point of 2.75. The feeling of achilles tendon release and Thompson sign had high sensitivity, prevalence, accuracy, and posttest probability. The confirmation of tendon release based on clinical signs could prevent the use of US.

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BACKGROUND: Percutaneous needle tenotomies constitute a promising approach that enables direct access to tendons through minimally invasive interventions. They can be performed rapidly without need for large incisions or general anaesthesia. However, the reported procedures are heterogeneous and currently conducted without guidelines. OBJECTIVES: We aimed to determine the indications for percutaneous needle tenotomies described in the current literature. Our secondary aim was to identify the different procedures reported, as well as their efficacy and their safety. METHODS: A systematic review following PRISMA guidelines was conducted to identify original articles that mentioned percutaneous needle tenotomy in humans and reported its application, description, effectiveness or adverse events. Non-percutaneous tendinous surgical procedures and ineligible designs were excluded. The Downs and Black checklist was used to assess the risk of bias. RESULTS: A total of 540 studies were identified from the MEDLINE, Embase, Cochrane Library, and PEDro databases. Fourteen clinical studies met the inclusion criteria and were found to have an acceptable quality (674 individuals, 1664 tenotomies). Our results indicated a wide variety of indications for percutaneous needle tenotomies in children and in adults. We highlighted 24 tendons as eligible targets in the upper and lower limbs. Tenotomies were performed with either 16- or 18-Ga needles, lasted from 1 to 30 min, and were performed using various procedures. Their efficacy was mainly assessed through clinical outcomes highlighting tendon discontinuity on palpation after the procedure. Passive range-of-motion gains after tenotomy were reported for both upper and lower limbs with an estimated 5 % complication rate. CONCLUSION: This is the first review to systematically synthesize all the available evidence on the indications, procedures, efficacy and safety of percutaneous tenotomies exclusively performed with needles. Current evidence suggests that procedures are safe and effective for treating various deformities. PROSPERO REGISTRATION: CRD42022350571.

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BACKGROUND: The Ponseti method for treating clubfoot consists of initial treatment with serial casting accompanied by achillotenotomy if needed, followed by the maintenance phase including treatment with a foot abduction orthosis (FAO) for at least four years. This study aimed to examine the duration, course, and outcome of orthotic treatment in children with clubfoot. METHODS: 321 children with clubfoot, born between 2015 and 2017, registered in the Swedish Pediatric Orthopedic Quality Register (SPOQ), were included in this prospective cohort study. Data on deformity characteristics and orthotic treatment were extracted. For children with bilateral clubfoot, one foot was included in the analysis. RESULTS: Of the 288 children with isolated clubfoot, 274 children (95.5%) were prescribed an FAO, and 100 children (35%) changed orthosis type before 4 years of age. Of the 33 children with non-isolated clubfoot, 25 children (76%) were prescribed an FAO, and 21 children (64%) changed orthosis type before 4 years of age. 220 children with isolated clubfoot (76%), and 28 children with non-isolated clubfoot (84%) continued orthotic treatment until 4 years of age or longer. Among children with isolated clubfoot, children ending orthotic treatment before 4 years of age (n = 63) had lower Pirani scores at birth compared to children ending orthotic treatment at/after 4 years of age (n = 219) (p = 0.01). It was more common to change orthosis type among children ending orthotic treatment before 4 years of age (p = 0.031). CONCLUSIONS: The majority of children with clubfoot in Sweden are treated with an FAO during the maintenance phase. The proportion of children changing orthosis type was significantly greater and the Pirani score at diagnosis was lower significantly among children ending orthotic treatment before 4 years of age. Long-term follow-up studies are warranted to fully understand how to optimize, and individualize, orthotic treatment with respect to foot involvement and severity of deformity. LEVEL OF EVIDENCE: II.

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Surgical management of the subscapularis tendon is critical to a successful outcome following anatomic total shoulder arthroplasty. However, the optimal surgical technique for adequate exposure of the glenohumeral joint while mini-mizing complications resulting from subscapularis tendon dysfunction continues to be controversial. Common surgical techniques for the management of the subscapularis tendon include tenotomy, peeling, sparing, and lesser tuberosity oste-otomy. Despite a number of published studies comparing these techniques, no consensus has been reached regarding optimal management. This article reviews the extensive literature on the biomechanical, radiologic, and clinical outcomes of each technique, including recently published comparison studies.

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Heterotopic ossification (HO), the pathological formation of bone within soft tissues such as tendon and muscle, is a notable complication resulting from severe injury. While soft tissue injury is necessary for HO development, the specific molecular pathology responsible for trauma-induced HO remains a mystery. The previous study detected abnormal autophagy function in the early stages of tendon HO. Nevertheless, it remains to be determined whether autophagy governs the process of HO generation. Here, trauma-induced tendon HO model is used to investigate the relationship between autophagy and tendon calcification. In the early stages of tenotomy, it is observed that autophagic flux is significantly impaired and that blocking autophagic flux promoted the development of more rampant calcification. Moreover, Gt(ROSA)26sor transgenic mouse model experiments disclosed lysosomal acid dysfunction as chief reason behind impaired autophagic flux. Stimulating V-ATPase activity reinstated both lysosomal acid functioning and autophagic flux, thereby reversing tendon HO. This present study demonstrates that autophagy-lysosomal dysfunction triggers HO in the stages of tendon injury, with potential therapeutic targeting implications for HO.

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PURPOSE: The influence of the subscapularis tendon on reverse total shoulder arthroplasty (RTSA) has been discussed controversially. The aim of the study was to investigate the subscapularis-sparing approach for RTSA and the effect of the intact subscapularis tendon. METHODS: This retrospective comparative study included 93 patients. Among these, 55 underwent the deltopectoral subscapularis-sparing approach, and in 38 cases, the standard deltopectoral approach with subscapularis tenotomy was applied. At the final follow-up, representative shoulder scores were measured, radiographs were taken in two planes, and shoulder sonography was performed. RESULTS: The subscapularis-sparing group showed a significantly higher Constant score (71.8 vs. 65.9 points) and adapted Constant score if the subscapularis tendon was shown to be intact in the postoperative sonography (85.2% vs. 78.6%) (p = 0.005; p = 0.041). Furthermore, these patients had improved abduction (128.2 vs. 116.8, p = 0.009) and external rotation (34.6 vs. 27.1, p = 0.047). However, no significant differences were found for the degree of internal rotation and internal rotation strength. No dislocation or infection was observed. The degree of scapular notching was not significantly different between the two groups (p = 0.082). However, independently from the integrity of the subscapularis the subscapularis-sparing approach showed no difference in clinical and radiographic outcome (Constant score scapularis-sparing 70.0 points vs. tenotomy 66.8 points; p = 0.27). CONCLUSION: The subscapularis-sparing approach RTSA showed improved clinical outcome, abduction, and external rotation, if the subscapularis was shown to be intact at time of follow-up. Both groups showed no difference in internal rotation.

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INTRODUCTION: The Ponseti serial casting method is the method of choice in treating children with congenital clubfeet. The arthrogrypotic clubfoot has traditionally been considered challenging to treat, with higher rates of recurrence and the need for more corrective surgeries. However, initial reports have found promising results in using the Ponseti method to treat arthrogrypotic feet. This study aims to compare the outcomes of idiopathic versus arthrogrypotic clubfeet following initial treatment with the Ponseti serial casting method. METHODS: A retrospective review of medical records from a single institution was conducted. Data was collected from children ages 0 to 18 with idiopathic or arthrogrypotic clubfoot treated from 2002 to 2022 with Ponseti-style serial casting with a minimum 2-year follow-up. Recurrence was defined as the need for additional casting or subsequent surgeries following initial correction. Data was collected on relevant patient demographics, previous treatment, casting records, Achilles tenotomies, and surgical treatments. RESULTS: A total of 352 patients (546 feet) met inclusion criteria. In all, 334 idiopathic and 18 arthrogrypotic patients were analyzed with an average follow-up duration of 3.4 and 4.2 years, respectively. Twelve patients had distal arthrogryposis, and 6 had amyoplasia. In all, 93.4% of idiopathic and 72.2% of arthrogrypotic patients successfully achieved correction with Ponseti casting and Achilles tenotomy. Recurrence rates were significantly higher in the arthrogrypotic group at 83.3% compared with 44.6% in the idiopathic group ( P =0.001). A posterior or posterior medial release was performed in 35.0% of idiopathic and 66.7% arthrogrypotic feet. CONCLUSIONS: We report the largest series of arthrogrypotic clubfeet treated by Ponseti casting to the best of our knowledge. In contrast to earlier reports, our investigation underscores that while the Ponseti method may be able to secure initial correction in arthrogrypotic clubfeet, on average, at a 3-year follow-up, the prognosis is less favorable. These patients exhibit higher recurrence and often require operative treatment. Notably, a posterior medial release may eventually be needed in up to 6 of 10 patients. LEVEL OF EVIDENCE: Level III-therapeutic studies-investigating the results of treatment.

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PURPOSE: Small angle hypertropia in sagging eye syndrome is conveniently treated by graded vertical rectus tenotomy, yet an adjustable technique under topical anesthesia has been recommended because of variability of effect. We performed graded tenotomy in an experimental model to elucidate the reason for variability of response to this surgical procedure. DESIGN: Experimental study. METHODS: Thirty-two fresh bovine rectus musculotendon specimens were prepared including continuity with insertional sclera, and extending for a total 40 mm length to the proximal muscle bellies, and trimmed to 16 mm width. Specimens were anchored by the clamps at the scleral insertion and muscle belly ends within a physiological chamber. After preconditioning and elongation to 10% strain was imposed by a linear motor, tensile force was allowed to stabilize at a plateau state. Then 25%, 50%, 75%, 90%, and 100% marginal tenotomies were performed progressively as remnant forces were measured. RESULTS: Tendon thickness averaged 0.29 ± 0.05 mm and width 19.71 ± 2.25 mm. On average, remnant force decreased linearly (R2 = 0.985) from 4.23 ± 1.34, 2.76 ± 0.88, 1.70 ± 0.73, 1.01 ± 0.49, 0.39 ± 0.10, and 0 N, at 0%, 25%, 50%, 75%, 90%, and 100% tenotomy. However, there was marked individual variability in effect among specimens, with coefficients of variation of 32%, 32%, 43%, 49%, and 27%, respectively. CONCLUSION: On average, there is a linear relationship between graded rectus tenotomy and percentage force reduction, but the effect among individual tendons is large, paralleling the reported variation in surgical effect. This explains and implies continued advisability of adjustable technique in this procedure.

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