Search Results (113)

The palmaris longus (PL) remains insufficiently quantified in cercopithecoids (Cercopithecoidea), despite growing comparative data across primates. We examined adult archival material of the Anubis baboon (Papio anubis) to document PL presence, tendon configuration and topography, describe muscle–tendon morphometrics, and test for side-, sex- and size-related effects. A PL was present in all limbs. Two tendon configurations were observed: a single tendon inserting into the palmar aponeurosis (Type I, 87.0%) and a bifurcated tendon with both medial and lateral slips inserting into the palmar aponeurosis (Type II, 13.0%). No side- or sex-related differences were found in variant distribution. Males showed larger absolute values for selected measurements, but these differences were not independent of antebrachial size. PL lengths and interstyloid distances were strongly correlated with antebrachial size, indicating overall scaling with limb dimensions. These findings identify a species-level pattern in which PL is consistently present and predominantly unbranched, with only occasional distal bifurcation. The data establish a comparative anatomical baseline for Papio and broaden the available evidence on PL morphology in non-human primates. Full article

Background: Hallux valgus (HV) is a complex forefoot deformity influenced by interactions between osseous alignment, ligamentous restraint, and muscle–tendon forces. While the biomechanical role of ligament laxity and bone geometry has been extensively investigated, the contribution of tibialis anterior (TA) tendon insertion variability to medial column mechanics remains insufficiently understood. Materials and Methods: A patient-specific finite element model of the foot was developed from high-resolution computed tomography data. Five anatomically documented TA distal insertion configurations were modeled, representing different distributions of attachment to the medial cuneiform and first metatarsal base. All simulations were performed under identical boundary and loading conditions representative of the stance phase of gait. Global (full-foot) and local (first bone and first metatarsal) mechanical responses were quantified using total deformation, equivalent von Mises stress, and strain distributions. Results: Marked differences in mechanical behavior were observed across TA insertion types. The metatarsal-dominant configuration (Type 3) demonstrated the highest global and local deformation values (global deformation: 1.0928 mm; first bone deformation: 1.0928 mm) and elevated strain distributions, whereas the medial-dominant configuration (Type 2) showed minimal deformation (global: 0.0727 mm; first bone: 0.0350 mm) but the highest global equivalent von Mises stress (5.7698 MPa). The single-band insertion to the medial cuneiform (Type 5) produced the greatest localized stress in the first bone region (3.8634 MPa). Representative strain maps revealed distinct spatial redistribution patterns within the medial column associated with TA insertion geometry. Conclusions: This patient-specific finite element analysis indicated that distal TA insertion variability alone can substantially modify deformation, stress, and strain patterns within the medial column. These findings suggested that TA insertion anatomy may act as a biomechanical modulator of first-ray mechanics and should be considered in future studies investigating hallux valgus pathomechanics and personalized treatment strategies. Full article

Rotator cuff suture anchors have traditionally been inserted at the 45° “deadman” angle, but this recommendation was largely derived from single-row constructs and may not reflect the biomechanics of contemporary double-row suture bridge repairs. This study compared the biomechanical performance and stress distribution of medial row anchors inserted at 45° versus 90° in a double-row suture bridge construct. Sixteen ovine humeri with intact infraspinatus tendons were randomized to 45° or 90° medial anchor insertion (n = 8 each), and double-row suture bridge repair was performed using 3.5 mm metallic and PEEK anchors. Specimens underwent uniaxial tensile testing (10-N preload, 5 mm/min) to failure, measuring yield load, failure load, displacement, stiffness, and energy absorption; additionally, a CT-based finite element model of the human humerus assessed von Mises stress, strain, and deformation under 200 N loading. Mean failure load was 161.96 ± 50.99 N for 45° and 185.61 ± 60.97 N for 90° (p = 0.447), and stiffness was 31.63 ± 8.18 N/mm versus 36.79 ± 9.26 N/mm (p = 0.291). Displacement at failure was greater with 90° insertion (8.11 ± 0.51 mm vs. 6.65 ± 0.83 mm; p = 0.002), while energy absorption was higher but not significantly different (p = 0.255). Finite element analysis demonstrated lower bone von Mises stress with 90° insertion (14.03 MPa) compared with 45° (24.77 MPa), with similar deformation. In double-row suture bridge repair, 90° medial anchor insertion provides comparable fixation strength to that at 45° while reducing bone stress, suggesting a biomechanical advantage. Full article

Objectives: We aimed to evaluate Achilles tendon stiffness characteristics in asymptomatic patients with psoriatic arthritis (PsA) using shear wave elastography (SWE). Methods: In this prospective case–control study, 34 asymptomatic PsA patients and 34 age- and sex-matched healthy controls underwent bilateral Achilles tendon evaluation with grayscale ultrasonography and SWE. Tendon thickness was measured 3 cm proximal to the calcaneal insertion. Shear-wave velocity (m/s) and Young’s modulus (kPa) were obtained under standardized acquisition conditions, including five-star motion stability and ≥90% reliability. Results: Achilles tendon morphology and thickness did not differ between PsA patients and controls (p > 0.05). In contrast, SWE demonstrated higher tendon stiffness in the PsA group. Mean shear-wave velocity was significantly greater in PsA patients for both the left (4.89 ± 2.52 m/s vs. 3.23 ± 0.41 m/s; p < 0.001) and right tendons (4.88 ± 1.94 m/s vs. 3.12 ± 0.30 m/s; p < 0.001), with corresponding increases in Young’s modulus (all p < 0.001). SWE demonstrated good group discrimination, with shear-wave velocity achieving AUC values of up to 0.90 in differentiating PsA patients from healthy controls. Conclusions: SWE may reflect biomechanical tendon alterations in PsA, even in the absence of clinical symptoms, and may serve as a complementary imaging tool in the assessment of tendon involvement. Full article

The iliopsoas muscle (IPM) is a flexor of the hip joint in dogs that is vulnerable to injury. Intraobserver and interobserver reliability of musculoskeletal ultrasound when evaluating the tendon of insertion of the IPM was studied. The IPM tendons of insertion of a randomly selected cohort were screened by one investigator and recorded. Musculoskeletal ultrasound recordings were separated into two groups of 20 dogs with presumptively normal IPM tendons of insertion and 32 dogs with one or two presumptively abnormal IPM tendons. Recordings were anonymized. The 104 tendons from these 52 dogs were independently reviewed twice by three observers. Abnormalities were detected in 6 of 40 presumptively normal IPM tendons (15%) and 59 of 64 presumptively abnormal IPM tendons (92%). Intraobserver repeatability of measurements of tendon dimensions was good (range, 0.24 to 0.76 mm), intraobserver reliability was good or excellent (range, 0.812 to 0.917), and intraobserver consistency was good (all coefficients of variation <20%). All measurements had poor interobserver consistency (intraclass correlation coefficients <0.500). Measurements of the tendon of insertion of the IPM have acceptable intraobserver repeatability, consistency, and reliability but have poor interobserver consistency, suggesting that efforts should be made to standardize the interpretation methods when using diagnostic ultrasound to evaluate problems affecting the tendon of insertion of the IPM in dogs. Full article

Background: The traditional A1-centric paradigm for trigger finger (TF) management does not fully capture heterogeneous pathology spanning isolated pulley stenosis, tendon degeneration, and impaired tendon–sheath gliding. Methods: A comprehensive literature synthesis (2010–2025) integrating anatomy, biomechanics, and ultrasound-guided interventions was performed to develop a testable, phenotype-driven framework. Results: A continuum model is proposed emphasizing (i) origin-to-insertion assessment of the flexor apparatus, (ii) pragmatic ultrasound phenotyping into pulley-dominant, tendon-dominant, and mixed patterns, and (iii) a stepwise, phenotype-matched management pathway incorporating conservative care, ultrasound-guided injection, selected adjuncts (e.g., hydrodissection, prolotherapy, ESWT) for tendon-dominant or mixed presentations, and percutaneous or open release when an A1 bottleneck is confirmed. Conclusions: This framework is presented as a hypothesis to guide standardized reporting, reliability testing, and phenotype-stratified comparative trials, rather than as a validated clinical guideline. This article proposes a novel, phenotype-driven clinical framework to address this limitation. Contemporary evidence is integrated to construct a model emphasizing (i) a whole-length, origin-to-insertion assessment of the flexor apparatus, (ii) sonographic phenotyping into pulley-dominant, tendon-dominant, and mixed patterns, and (iii) a stepwise treatment algorithm integrating conservative care, ultrasound-guided injections, ultrasound-guided percutaneous release, and selected adjunctive approaches such as hydrodissection (HD), prolotherapy (Prolo), and extracorporeal shockwave therapy (ESWT). While evidence supports individual modalities, the framework’s primary innovation lies in matching interventions to phenotype. This sonographic phenotyping system is presented not as a validated tool, but as a testable hypothesis designed to guide future validation studies. The proposed framework establishes research priorities, including standardized criteria, reliability testing, and comparative effectiveness research for phenotype-stratified management. Full article

Background: Treatment of chronic painful insertional Achilles tendinopathy is known to be challenging. If non-surgical treatment does not give sufficient relief of symptoms, surgery may be indicated. Treatment with ultrasound (US)- and colour Doppler (CD)-guided wide-awake-local-anaesthetic-no-tourniquet (WALANT) surgery for insertional Achilles tendinopathy is a new approach with promising clinical results. This study aimed to evaluate clinical results of this new approach on patients suffering from insertional Achilles tendinopathy. Methods: Forty-eight consecutive patients with 53 symptomatic tendons (33 men with 34 tendons, mean age 49.3 ± 12.0 years; 14 women with 18 tendons, mean age 55.0 ± 7.4 years) and a duration of more than 12 months with painful insertional Achilles tendinopathy (including tendon, bursae, bone, and plantaris pathology) were included. US- and CD-guided WALANT surgery with removal of pathological bursae, bone, and tendons was used. Immediate weight-bearing loading was allowed, followed by a structured rehabilitation protocol for the first 12 weeks after surgery. VISA-A scores before and after surgery and a questionnaire that evaluated subjective satisfaction with the treatment and current activity level were used. Results: In total, 42/48 patients with 46/53 tendons participated in a 3-year follow-up (mean 34 ± 9 months) by an independent examiner; 39/42 patients with 43/46 tendons were satisfied (n = 37) with the treatment. The mean VISA-A score increased significantly from 41.9 ± 18.2 pre-operatively to 87.7 ± 18.2 post-operatively (p < 0.001). There were three surgical complications, two superficial wound infections, and one minor wound rupture. Conclusions: Patients who suffered from chronic painful insertional Achilles tendinopathy treated with US- and CD-guided WALANT surgery followed by immediate weight-bearing showed high patient subjective satisfaction rates and better functional scores at the 3-year follow-up with a low complication rate. This novel treatment approach warrants more study, including randomised trials comparing it against traditional surgical procedures according to Nunley and Keck and Kelly. Full article

Background/objective: The palmaris longus muscle is a variable and often inconsistent muscle in the anterior compartment of the forearm. This fusiform-shaped muscle originates at the medial epicondyle of the humerus bone following a long and narrow tendon that inserts at the palmar aponeurosis. That tendon is used in reconstructive surgery, and for this reason, detailed information from an ultrasound is used to detect the tendon and the possible variations in the muscle. The present study aimed to investigate the palmaris longus muscle and its variations through ultrasound, anatomical, and histological analysis with clinical and surgical applications. Methods: A total of 72 upper limbs from 33 females and 39 males, 32 right and 40 left, were evaluated in ultrasound, anatomical, and histological studies. The main objective was to prove the existence of the palmaris longus muscle and its variations, as well as to measure the tendon for surgical applications. Results: Ultrasound analysis showed that it is possible to determine the existence of the muscle (76.4%) and its variations (23.6%), as well as its absence (15.3%). The anatomical results proved the ultrasound results. The width of the tendon was between 0.4 and 0.38 mm. by ultrasound and anatomical analysis. Also, normal palmaris longus tendons were not a direct cause of compression of the median nerve. Conclusions: It is important to confirm the existence and possible variations in the palmaris longus muscle and tendon through ultrasound before surgical reconstruction and for clinical diagnostics. Full article

Background: The distal biceps brachii tendon inserts proximally and posteriorly on the bicipital tuberosity of the radius and it is a forearm supinator but also contributes to flexion of the elbow. Chronic distal biceps tendon ruptures are relatively rare, often complicated by tendon and muscle retraction, and, therefore, their primary repair is difficult or impossible. The gold standard treatment of these chronic lesions is its anatomic reinsertion at the radial tuberosity after tendon reconstruction, using autograft or allograft tissue, but there is no agreement about the most appropriate surgical technique. Untreated injuries usually result in elbow joint deficits and decreased muscular strength. We report the preliminary results in a group of patients treated with a tripled autologous semitendinosus graft. Methods: In the present retrospective study, we report the results in a series of 13 patients surgically treated using tripled autologous semitendinosus graft, fixed to the residual distal biceps tendon, starting from the myotendinous junction, and using tension-slide technique (Biceps Button—Arthrex, Inc, Naples, FL 34108, USA) in association with an interference screw. Eleven males and two females, with a mean age of 46, participated in the study. Results: At mean follow-up check-in of 35 months, clinical results were assessed using the DASH score and MEPS, with a mean value of 11 points and 87 points, respectively. Tensiomyography was also performed to evaluate muscular strength. Six patients had excellent results and seven had good results. No patient had either a tendon re-rupture, or a peripheral neurological deficit, or symptomatic heterotopic ossifications. Seven patients had a mild deficit in elbow motion and six patients had a mild deficit in forearm prono-supination. Upon tensiomyography evaluation, five patients showed a mild deficit in flexion and supination strength. All patients returned to their previous daily and sporting activities. Conclusions: According to our results, in patients affected by chronic distal biceps tendon rupture, surgical treatment performed using tripled autologous semitendinosus autograft secured to the radial tuberosity using the tension-slide technique and interference screw is associated with satisfactory outcomes. Full article

Objectives: Previous studies have suggested the potential for semitendinosus (ST) tendon regeneration following harvesting for anterior cruciate ligament (ACL) reconstruction. This retrospective cross-sectional (observational) study aims to evaluate ST tendon regeneration using high-resolution ultrasound (US), with special reference to morphological and structural changes in the muscle–tendon unit. Methods: Twenty-four patients who had undergone ST tendon harvesting at least 24 months prior were evaluated. Ultrasound assessment included neotendon (NT) detection, thickness, echotexture, insertion site, dynamic gliding, myotendinous junction (MTJ) shifting, and muscle cross-sectional area (CSA), compared with the healthy contralateral side. Results: ST tendon regeneration was detected in 19/24 patients (79%). In regenerated tendons, NT thickness was significantly greater than the native tendon (3.40 ± 1.38 mm vs. 2.40 ± 0.27 mm; mean difference 0.98 mm; p = 0.005. Subgroup analysis revealed that fibrillar-like NTs were associated with a smaller MTJ shift (3.91 ± 1.14 cm vs. 7.75 ± 2.43 cm; p = 0.001) and higher muscle CSA preservation (0.85 ± 0.10 vs. 0.55 ± 0.09; p < 0.001). A strong inverse correlation was found between MTJ displacement and muscle CSA (ρ = −0.96; p < 0.001). Patients without NT regeneration (n = 5) exhibited more pronounced MTJ retraction (11.0 ± 1.0 cm) and muscle hypotrophy (CSA ratio 0.41 ± 0.07), although these results were descriptive. Conclusions: High-resolution US is an effective, non-invasive method for assessing ST tendon regeneration from a qualitative and quantitative perspective. Our findings indicate possible changes in the architecture and position of the regenerated tendon, the MTJ, and the muscle belly, which may reflect structural remodeling of the muscle–tendon unit. Full article

Background: Prolotherapy (proliferative therapy) is a nonsurgical regenerative injection technique that introduces small amounts of hyperosmolar dextrose to the site of painful or degenerated tendons or their insertions. Under ultrasound guidance, a 25-gauge needle is used to fenestrate and inject hyperosmolar dextrose into the injured area of the Achilles tendon. This is found to induce the proliferation of new cells, allowing the regeneration of healthy tissue. The purpose of this study was to evaluate the treatment response to prolotherapy in Achilles tendinitis. Methods: We reviewed 132 participants with nontraumatic Achilles tendinopathy. Data were collected retrospectively from electronic health records from January 1, 2014, to December 31, 2017. These participants have Achilles tendinopathy from daily activity. We excluded any traumatic cause, history of Achilles tendon rupture, and tendon pathology. Participants were followed for 12 months; those lost to follow-up were excluded. The duration of pathology, number of prolotherapy sessions, and outcome data were recorded. Musculoskeletal radiologists performed the prolotherapy. We received an exemption from the institutional review board of Boston Medical Center for this study. Results: One hundred thirty-two participants (45 men and 87 women) met the study’s criteria, with a mean age of 55 years (range, 21–80 years). Overall, within 12 months, 98 participants (74.2%) experienced symptom resolution. Seventy-one participants (53.8%) experienced symptom improvement with a single treatment. Thirty-four participants (25.8%) still had symptoms after 12 months. Conclusions: This study demonstrated that prolotherapy yielded excellent results for Achilles tendinitis, particularly for participants without skeletal deformities. No adverse events were reported during the 12-month study. A prospective, comparative, and randomized controlled study with long-term follow-up is needed to determine the efficacy of prolotherapy. (J Am Podiatr Med Assoc 115(6), 2025; doi:10.7547/23-186) Full article

Background: Medial columnnails have been introduced intoCharcot’s neuroarthropathy reconstruction as superconstruct fixation with high fatigue strength and pullout resistance. Similar to intramedullary nailing throughout other long-bone fixation, injury to neurovascular and musculotendinous structures secondary to percutaneous interlocking screwfixationmay exist.We sought to identify structures at risk for injury during the interlocking of amedial column nail. Methods: Medial column nails were inserted into ten cadaveric limbs. The proximal (talar), middle (first metatarsal), and distal (first metatarsal) locations for the interlocking screws were drilled, and a 0.062 Kirschner wire was inserted into respective drillholes to simulate interlocking screws. After dissection, the distances of each Kirschner wire to nearby anatomical structures were measured. Levels of risk were assigned to each soft-tissue structure based on distance to each Kirschner wire: high (0–3.5 mm), intermediate (3.6–7.0 mm), and low (> 7.0 mm). A 3.5-mm threshold for each category was used because this represented a multiple of the diameter of the interlocking screws. Mean ± SD and ranges are reported for structures at high and intermediate risk for injury. Results: Proximally, the deltoid ligament (ten of ten), posterior tibial tendon (eight of ten), and saphenous vein (six of ten) were at high or intermediate risk for injury consistently. At the middle screw, the medial dorsal cutaneous nerve and the medial marginal vein were at high or intermediate risk in ten and eight specimens, respectively. At the distal interlocking screw, the medial dorsal cutaneous nerve was at high risk for injury in all ten specimens. Conclusions: There is high and intermediate risk to many musculotendinous and neurovascular structures when performing percutaneous interlocking screws in a medial column nail. These findings serve to educate surgeons of the anatomical considerations they must have when performing medial column nailing for reconstruction of Charcot’s foot. Full article

Suture anchors are widely used for tendon and ligament repair, but their fixation strength is compromised in osteoporotic bone and limited bone volume such as the coracoid process. Existing designs are prone to penetration and insufficient cortical engagement under such conditions. In this study, we developed a novel short expandable-wing (SEW) suture anchor (Ti6Al4V) designed to enhance pull-out resistance through a deployable wing mechanism that locks directly against the cortical bone. Finite element analysis based on CT-derived bone material properties demonstrated reduced intra-bone displacement and improved load transfer with the SEW compared to conventional anchors. Mechanical testing using matched artificial bone surrogates (N = 3 per group) demonstrated significantly higher static pull-out strength in both normal (581 N) and osteoporotic bone (377 N) relative to controls (p < 0.05). Although the sample size was limited, results were consistent and statistically significant. After cyclic loading, SEW anchor fixation strength increased by 25–56%. In a 3D-printed anatomical coracoclavicular ligament reconstruction model, the SEW anchor provided nearly double the fixation strength of the hook plate, underscoring its superior stability under high-demand clinical conditions. This straightforward implantation protocol—requiring only a 5 mm drill hole without tapping, followed by direct insertion and knob-driven wing deployment—facilitates seamless integration into existing surgical workflows. Overall, the SEW anchor addresses key limitations of existing anchor designs in small bone volume and osteoporotic environments, demonstrating strong potential for clinical translation. Full article

Background: Anatomical variations of the extensor hallucis longus (EHL) tendon hold significant implications for foot and ankle surgery, yet they remain underrepresented in orthopedic literature. Accurate recognition of these variants is crucial for minimizing iatrogenic injuries and improving surgical outcomes. Aim: This narrative review aims to summarize current anatomical knowledge on EHL tendon morphology, with a particular focus on the classification system proposed by Olewnik et al. Emphasis is placed on its diagnostic, radiological, and surgical relevance. Methods: A comprehensive literature review was conducted, integrating findings from cadaveric dissections, imaging studies, and clinical observations. The Olewnik classification—based on the number and insertion of EHL tendon slips—serves as the organizing framework for the anatomical and surgical discussion. Findings: The Olewnik classification delineates three primary types: Type I (single slip), Type II (two slips, subdivided into IIa–IIc), and Type III (three slips). Each type is discussed in terms of anatomical features, diagnostic challenges on MRI and ultrasound, and implications for surgical exposure, tendon transfer, and graft harvesting. Comparative analysis with prior typologies underscores the enhanced clinical utility of the Olewnik system. Conclusions: The reviewed classification offers a reproducible, imaging-compatible, and surgically applicable framework for understanding EHL tendon variability. Incorporating this system into preoperative planning may enhance procedural safety and precision. Further clinical validation and broader integration into surgical education are warranted. Full article

Damaged connective tissues between the bone and tendons or ligaments are common among adults regardless of activity level. Achilles tendinosis is one of the most common tissue defects and enthesopathies. This case report presents the novel application of Wharton’s jelly to supplement tissue defects in the Achilles tendon and its insertion. The patient in this study is a 54-year-old female with slow-onset chronic Achilles tendinosis from chronic enthesopathy at the Achilles tendon insertion with a retrocalcaneal exostosis progressively worsening for 3 years, who failed standard-of-care practices for more than 3 years. Her previous care included rest, one successful inferior calcaneal osteotomy, and one minimally successful retrocalcaneal resection of the contralateral foot, both performed by prior surgeons. The patient received extracorporeal pulsed-activated therapy (EPAT) before applying 2 mL of CryoText, a Wharton’s jelly tissue allograft. The patient then received class IV laser therapy treatments. The patient started with a 10/10 visual analog scale (VAS) at the initial visit, and by week 13, the patient rated her pain as 0/10 VAS. The improvement in patient-reported pain and functionality reported in this study after the application of Wharton’s Jelly, EPAT, and class IV laser therapy warrants future research studying the safety and efficacy of these patient care modalities together as an alternative intervention for patients with Achilles Tendinosis who have failed other standard-of-care treatments. Future research will help identify additional application sites and solidify application and dosage protocols. Full article