Tendon Length Research Articles

EFFECT OF CHANGES IN THE LENGTH OF THE COMPONENTS OF THE MUSCULOTENDINOUS ELEMENT OF THE ELBOW FLEXOR MUSCLES ON THE ISOMETRIC FORCE AND JOINT TORQUE

Immobilization of the joint leads to the formation of immobilization contracture, which is accompanied by a decrease in the elasticity of tendons and muscles, i.e. loss of full contraction and stretching. The torque in human joints is one of the key indicators in assessing rehabilitation. Objective. To study the effect of changes in the strength, length of muscles and tendons of the elbow joint on the torque in flexion. Methods. The basic OpenSim model arm26 was used for modeling. To determine the change in the length of the components of the muscle-tendon element (MTE), their length was determined at a 90° angle of elbow flexion. The decrease in muscle strength was considered a loss per day for elbow flexors — 1.2 %, extensors — 1.1 %. The decrease in strength was calculated for a period of immobilization of 45 days. Three models were created: Normal — a model without changes in muscle parameters; Contracture — a change in the length of muscles and tendons; Contracture + muscle (CM) — an additional decrease in muscle strength. Results. The obtained data of torques when changing the length of the MTE components showed their increase in conditions of unchanged isometric muscle strength. But this option is not possible after immobilization of the limb. Therefore, it is closer to the real model of СM, in which the torque is significantly reduced by the amount of decrease in muscle strength. These models show a tendency that the change in the components of the MTE due to immobilization increases the joint torque and, when trying to apply excessive force during joint development, can lead to traumatic consequences. During immobilization, the flexor muscles shorten, which prevents the patient from fully extending the elbow joint. Conclusions. This work on predicting the elbow joint torque generated by the muscles can be useful in studying specific clinical situations with elbow joint contractures, but cannot be fully transferred to practice due to the significant conventionality of the model parameters. However, the modeling method can show trends in changes in muscle function parameters when their geometry changes.

Minimally Invasive Peroneal Tenodesis Assisted by Peroneal Tendoscopy: Technique and Preliminary Results.

Introduction: Peroneal disorders are a common cause of ankle pain and lateral instability and have been described in as much as 77% of patients with lateral ankle instability. Clicking, swelling, pain, and tenderness in the peroneal tendons track are frequent symptoms, but they can be confused with other causes of lateral ankle pain. The management of peroneal disorders can be conservative or surgical. When the conservative treatment fails, surgery is indicated, and open or tendoscopic synovectomy, tubularization, tenodesis or tendon transfers can be performed. The authors present a surgical technique of tendoscopy associated to minimally invasive tenodesis for the treatment of peroneal tendon tears, as well as the preliminary results of patients submitted to this procedure. Methods: Four patients with chronic lateral ankle pain who were diagnosed with peroneal brevis pathology were treated between 2020 and 2022 with tendoscopic-assisted minimally invasive synovectomy and tenodesis. Using a 2.7 mm 30° arthroscope and a 3.0 mm shaver blade, the entire length of the peroneus brevis tendon and most parts of the peroneus longus tendon can be assessed within Sammarco's zones 1 and 2. After the inspection and synovectomy, a minimally invasive tenodesis is performed. Results: All patients were evaluated at least six months after surgery. All of them reported improvement in daily activities and in the Foot Function Index (FFI) questionnaire (pre-surgery mean FFI = 23.86%; post-surgery mean FFI = 6.15%), with no soft tissue complications or sural nerve complaints. Conclusion: The tendoscopy of the peroneal tendons allows the surgeon to assess their integrity, confirm the extent of the lesion, perform synovectomy, prepare the tendon for tenodesis, and perform it in a safe and minimally invasive way, reducing the risks inherent to the open procedure.

Change in Achilles Tendon Length after Walking on Treadmill with Gradient.

Improving ankle joint contracture is important because stiffness in ankle dorsiflexion can lead to pain, especially when weight-bearing during walking, which tends to concentrate on the forefoot. We hypothesized that the contraction of the gastrocnemius muscle in ankle dorsiflexion would increase the Achilles tendon length and improve the dorsiflexion range of motion. We evaluated the effects of walking with and without a gradient on Achilles tendon length. This study included 23 men who underwent ultrasound imaging to measure the Achilles tendon length while they stood on an inclined table adjusted according to the dorsiflexion angle. Treadmill walking was performed for 10 min with a 10° incline (gradient condition) or without gradient (level condition). The measurements were compared using a paired t-test. In the gradient condition, the range of motion for ankle dorsiflexion was significantly increased after the intervention. In the gradient condition, the Achilles tendon length while standing on an inclined surface was significantly increased after the intervention. Walking under gradient conditions led to the extension of the Achilles tendon in the ankle dorsiflexion position. This was accompanied by contraction of the gastrocnemius muscle, resulting in lengthening of the Achilles tendon. This finding suggests that such interventions may have clinical applications.

Revision Patellar Tendon Reconstruction Using Hamstring Tendon Autograft

Background: Patellar tendon ruptures presenting in a chronic setting are rare events that impose technical surgical challenges due to proximal retraction of the patella, quadriceps muscle atrophy and contracture, and peripatellar adhesions. Various reconstruction techniques have been described using different grafts and fixation methods; however, there is a paucity of reported outcomes and there is no consensus on standard of care. Indications: The patient is a 36-year-old man who presented with a failed patellar tendon reconstruction 14 months after his initial surgery (performed 1 year after the initial injury) with functional weakness and loss of extension. The patient was indicated for a revision patellar tendon reconstruction due to persistent functional limitations. Technique Description: The revision patellar tendon reconstruction was performed with gracilis and semitendinosus tendon autografts harvested from the ipsilateral limb. Hardware was removed from the initial graft tunnels in the tibial tubercle and patella. Patellar height was estimated using fluoroscopic measurement of the contralateral patellar tendon length. The graft is first passed through the patellar tunnel, and the individual limbs of the graft are then both placed through the tibial tubercle tunnel. A sternal wire in a figure-of-eight configuration was used to progressively distalize the patella to match the native patellar height, and the graft was then tensioned and secured together. Results: The patient regained full range of motion at 2-year follow-up and was able to return to work and activities without functional limitations. Recent case series also using ipsilateral hamstring tendon autograft for chronic patellar tendon reconstruction report improved patient outcome scores, normal Insall-Salvati index, improved quadriceps strength, and high levels of patient satisfaction. Discussion/Conclusion: Chronic patellar tendon ruptures are technically challenging to treat, especially in the context of revision of a failed reconstruction. The technique presented in this video may aid orthopaedic surgeons in treating this rare but debilitating injury. Given the lack of high-quality evidence, future studies are needed to explore graft choices, graft fixation techniques, and postoperative protocols. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Correlation of Anthropometric Measurements with Hamstring Graft Size in Anterior Cruciate Ligament Reconstruction in Nepalese Population: A Prospective Observational Study

Background: The use of autologous hamstring tendon for arthroscopic Anterior Cruciate ligament (ACL) reconstruction is very common. The size of hamstring tendons varies significantly between individuals, and graft diameter is unpredictable. Anthropometric measurements may be a simple way to estimate hamstring tendon length and diameter. This study aims to determine the correlation between anthropometric measurements of patients with length and diameter of harvested hamstring autograft during ACL reconstruction.Methods: A prospective observational study was carried out after ethical approval. All patients who underwent arthroscopic ACL reconstruction from 1 March 2022 to 30 April 2023 in Birat Medical College Teaching Hospital were included. Fourty seven patients’ age, sex, height, weight and thigh length were recorded preoperatively. Hamstring tendons were harvested and length of the semitendinosus tendon and diameter of the quadrupled graft (doubled semitendinosus and doubled gracilis) was measured intraoperatively. We used Pearson’s correlation coefficient to observe the relationship between anthropometric measurements and graft variables.Results: Mean length of harvested semitendinosus tendon was 27.4 ± 1.8 cm and mean quadrupled hamstring autograft diameter was 7.4 ± 0.8 mm. A significant positive correlation between graft variables (semitendinosus tendon length and quadrupled hamstring autograft diameter) and patients’ height and thigh length was found.Regression equations for predicting Semitendinosus tendon length and quadrupled hamstring autograft diameter from thigh length in males and females are also derived.Conclusion: Height and thigh length of patients are useful parameters for predicting semitendinosus tendon length and quadrupled hamstring graft diameter before ACL reconstruction.

ISB clinical biomechanics award winner 2023: Medial gastrocnemius muscle and Achilles tendon interplay during gait in cerebral palsy

BackgroundThe interplay between the medial gastrocnemius muscle and the Achilles tendon is crucial for efficient walking. In cerebral palsy, muscle and tendon remodelling alters the role of contractile and elastic components. The aim was to investigate the length changes of medial gastrocnemius belly and fascicles, and Achilles tendon to understand their interplay to gait propulsion in individuals with cerebral palsy. MethodsTwelve young individuals with cerebral palsy and 12 typically developed peers were assessed during multiple gait cycles using 3D gait analysis combined with a portable ultrasound device. By mapping ultrasound image locations into the shank reference frame, the medial gastrocnemius belly, fascicle, and Achilles tendon lengths were estimated throughout the gait cycle. Participants with cerebral palsy were classified into equinus and non-equinus groups based on their sagittal ankle kinematics. FindingsIn typically developed participants, the Achilles tendon undertook most of the muscle-tendon unit lengthening during stance, whereas in individuals with cerebral palsy, this lengthening was shared between the medial gastrocnemius belly and Achilles tendon, which was more evident in the equinus group. The lengthening behaviour of the medial gastrocnemius fascicles resembled that of the Achilles tendon in cerebral palsy. InterpretationThe findings revealed similar length changes of the medial gastrocnemius fascicles and Achilles tendon, highlighting the enhanced role of the muscle in absorbing energy during stance in cerebral palsy. These results, together with the current knowledge of increased intramuscular stiffness, suggest the exploitation of intramuscular passive forces for such energy absorption.

The Basas Spanish Squat: Superimposition of Electrical Stimulation to Optimize Patellar Tendon Strain: A Case Series.

The Basas Spanish Squat with electrical stimulation (E-stim) has shown promising results as a potential key exercise in treatment of athletes with patellar tendinopathy. Gold standard exercise therapy for tendon injuries consists of tendon loading exercises, or exercises that appropriately applies high levels of mechanical strain to the tendon. The theoretical pathway in which the Basas Spanish Squat with E-stim improves tendinopathy has been speculated to be the additional strain applied through the patellar tendon during superimposition of E-stim. This theory, however, has yet to be confirmed. The purpose of this case series was to compare patellar tendon strain, during the Basas Spanish Squat with, and without E-stim, and open kinetic chain knee extension. Four healthy participants performed the three exercises while a physical therapist collected simultaneous unilateral ultrasound images from the patellar tendon. Strain was calculated as the change in patellar tendon length during contraction divided by the resting length. Amongst all participants, patellar tendon strain was smallest during the Basas Spanish Squat without E-stim, followed by the open kinetic chain knee extension at 60% maximum voluntary isometric contraction. The Basas Spanish Squat with E-stim yielded approximately double or more strain compared to the without E-stim condition and demonstrated higher level of strain compared to open kinetic chain knee extension in all participants. The findings reflect a clear trend of increased strain through the patellar tendon when E-stim was superimposed. The results support the theory that the Basas Spanish Squat with E-stim increases patellar tendon strain and could explain the reported clinical benefits in individuals with patellar tendinopathy. 4, Case series.

The effect of changing the length of the components of the muscle-tendon unit of the knee joint on its isometric force and torque

Background. A knee contracture developed due to immobilization after extra-articular injuries leads to lameness, impaired walking, and the appearance of pain in other joints of the lower limb. Long-term immobilization of the joint leads to weakening and increasing stiffness of muscles, changes in the length of tendons and myofibrils, loss of cushioning properties of cartilage, inhibition of blood circulation processes in the periarticular tissues. Adequate rehabilitation and recovery of the knee joint function after immobilization is a medical and social problem in terms of reducing disability. The goal of the work: to study the influence of changes in strength, length of muscles and tendons of the knee joint on torque. Materials and methods. The OpenSim Leg39.osim base model was used for simulation. The parameters of the muscles and tendons were changed in accordance with the conditions of immobilization for 45 days at the angle of preferential position of the limb — 15°. Three models were analyzed: a basic model without changes in muscle parameters, a model with a change in the length of the muscle-tendon unit, and a model with an additional change in muscle strength (according to calculations). Results. Changing the length of the components of the muscle-tendon unit of the flexors has little effect on both the isometric strength of the muscles and the knee joint torques produced by these muscles. A decrease in the maximum isometric force of the flexor muscles leads to a decrease in torque. When the length of the extensors changes, there is a sharp increase in the isometric force and torques of the knee joint and a change in the direction of the active torque trajectory. A decrease in muscle strength leads to a decrease in the level of torques approaching normal, but the direction remains unchanged. Conclusions. Mathematical modeling of the effect of changes in the components of the muscle-tendon unit of the muscles responsible for the movement of the knee joint showed that minor alterations in their length lead to noticeable violations of both the torque of the joint and changes in the isometric strength of the muscle during movements. Predicting the change in knee joint torque can be useful in studying specific clinical situations with contractures caused by a long-term immobilization after extra-articular injuries. But it cannot be fully transferred into practice due to the significant conditionality of model parameters. The used modeling method can show trends in the change of muscle functioning parameters when changing their geometry, and can be extended to study of other muscle and joint parameters.

Rotator Cuff Tendon Dimensional Variability, Novel Patient-Specific Measurement Method—Morphological Measurement for Rotator Cuff Tendon

Introduction: The shoulder rotator cuff (RC) is crucial to shoulder function and involvement in shoulder pathology. RC tears have been extensively studied, and several classifications have been devised to quantify their magnitude. Various RC measurement techniques were introduced previously, utilizing cadaveric specimens, X-rays, CT scans, and MRI with different results published regarding humeral heads’ different plane diameters and the correlation to age, gender, and height. There are very few studies measuring RC length in the general population. Purpose: We aimed to assess the geometrical relation between rotator cuff tendon length and humeral head sagittal and axial diameters. Methods: A total of 100 shoulder MRI scans of labral tear-suspected patients were reviewed, and the geometrical parameters of the rotator cuff length and proximal humerus sagittal and axial diameters were measured. Results: The healthy population has wide variability in humeral diameter and rotator cuff length. We found a high correlation between humeral head sagittal and axial plane diameters and the rotator cuff tendon dimension. The orthogonal plane diameters disagree with the humeral head being round but rather spheric. The rotator cuff length changes according to the patient’s gender and height. Conclusion: This is a novel method for rotator cuff measurement, description, and classification according to the percentage of tear instead of length (cm). This method is more clinically oriented and relevant than most other previous methods.

Functional popliteal angle tests improve identification of short hamstring muscle–tendon length in patients with a central neurological lesion

This study introduces a functional exercise protocol to improve the identification for short hamstring muscle–tendon length (HMTL), a common contributor to crouch gait in patients with central neurological lesions (CNL). The functional exercise protocol incorporates a knee extension movement with hip in a flexed position, while standing on one leg (functional popliteal angle test) and walking with large steps to the current standard protocol (walking at comfortable speed and as fast as possible). The main aim was to establish whether the new protocol allows better determination of maximum HMTLs and diagnostics of short HMTL in patients with a CNL. Lower limb 3D marker position data from 39 patient limbs and 10 healthy limbs performing the exercises were processed in OpenSim to extract HMTLs. The new protocol provoked significantly larger HMTLs compared to the current standard protocol. The total number of limbs classified as having too short HMTLs reduced from 16 to 4 out of a total of 30 limbs walking in crouch. The new protocol improves determination of maximum HMTL, thereby improving short HMTL diagnostics and identification of patients in need of lengthening treatment. Inter-individual variability observed among patients, indicating the need to include all exercises for comprehensive diagnosis.

The accessory heads of the quadriceps femoris muscle may affect the layering of the quadriceps tendon and potential graft harvest lengths

PurposeThe aim of the study was to assess the quadriceps femoris system for the presence of additional layers.MethodsOne hundred and twenty-eight lower limbs fixed in 10% formalin were examined.ResultsFive types of quadriceps tendon layering were found based on the accessory heads of the quadriceps muscle. Type I (55%)—represented by four heads and four layers, and it was something new because standard orthopaedic textbooks described quadriceps tendon as a structure composed of only three layers. Type II (27.4%)—the first four layers were the same as in Type 1, but the accessory tendon of the fifth head of the quadriceps femoris muscle had the deepest attachments. Type III (10.9%)—this type included 6 heads of quadriceps femoris. It consisted of five layers. Type IV (3.1%)—this type included 7 quadriceps femoris heads. This type consisted of only four layers. Type V (3.1%)—this type included 8 heads of the quadriceps femoris heads. This type consist of 5 layers.ConclusionThe findings of this study provide a detailed anatomy of the quadriceps tendon including the accessory tendons of the accessory heads of the quadriceps tendon. The accessory heads of the quadriceps femoris muscle contribute to the layering of the quadriceps tendon. The second conclusion of this study is the development of safe distances depending on the types. Not all types are perfect for harvesting—Type IV seems to be the safest type, in turn Type V the most dangerous.

Evaluating the Suitability of the Plantaris Tendon for Sports Trauma Reconstruction and a Predictive Model of Tendon Length Based on Height and Leg Length.

This study evaluates the suitability of the plantaris tendon (PT) as a tendon graft donor for sports trauma reconstruction and proposes a predictive model for estimating PT length by using an individual's height and leg length. Anatomical dissection of 50 cadavers (32 males and 18 females) yielded precise measurements of PT length and width while also recording height and leg length. Among the lower limbs, 89% were suitable for at least one recommended graft suitability criterion. In addition, PT length exhibited robust positive correlations with height and leg length. Predictive equations were established for estimating the PT length based on leg length and height with consistency across sexes and sides: PT length = 0.605 + 0.396 × leg length (r = 0.721) and PT length = 1.480 + 0.193 × height (r = 0.626). This study underscores the grafting potential of the PT, providing a predictive tool that can aid surgeons in addressing tendon graft challenges within sports trauma scenarios.

Effect of the Copenhagen Achilles Rupture Treatment Algorithm (CARTA) on Calf Muscle Volume and Tendon Elongation After Acute Achilles Tendon Rupture: A Predefined Secondary Analysis of the First 60 Patients in a Randomized Controlled Trial.

Surgical treatment of acute Achilles tendon rupture (ATR) lowers the risk of rerupture and may reduce calf atrophy and elongation of the Achilles tendon. The Copenhagen Achilles Rupture Treatment Algorithm (CARTA) was developed to provide individualized treatment selection based on ultrasonographic evaluation of the rupture. In a randomized setup, the present study aimed to investigate whether treatment selection using the CARTA could reduce atrophy and tendon elongation compared with (1) patients treated surgically and (2) patients treated nonsurgically. Randomized controlled trial; Level of evidence, 2. A total of 60 patients with an acute ATR were randomly assigned to receive treatment based on the CARTA (intervention), surgical treatment (control), or nonsurgical treatment (control) in a 1 to 1 to 1 ratio. After 1 year, magnetic resonance imaging of both calves was performed, and muscle volume and Achilles tendon length were measured. Results were presented as the ratio between the affected and the unaffected limbs (ie, limb symmetry index; %). A total of 156 patients were assessed for eligibility, 60 patients were randomized, and 54 patients provided data for the study-19 patients received treatment based on the CARTA (intervention group), 17 patients received nonsurgical treatment (control), and 18 patients received surgical treatment (control). No statistically significant differences were found between the intervention group and the 2 control groups regarding muscle volume and tendon length. No statistically significant differences were found between patients treated surgically and patients treated nonsurgically. Comparison between the affected and the unaffected limb showed statistically significant muscle atrophy (24%-30%) and tendon elongation (soleus, 59%-76%; gastrocnemius, 8%-14%) in the affected limb in all 3 groups. Individualized treatment of acute ATR using an ultrasonographic selection algorithm did not reduce calf muscle atrophy or tendon elongation when compared with surgical and nonsurgical treatment. Surgical treatment did not reduce calf muscle atrophy or tendon elongation compared with nonsurgical treatment.

Early Tendon Morphology as a Biomarker of Long-term Patient Outcomes After Surgical Repair of Achilles Tendon Rupture: A Prospective Cohort Study

Background: Patient outcome after acute Achilles tendon rupture (ATR) varies and is difficult to predict. Whether early variations in healing, visualized with ultrasonography, can predict long-term patient outcome is unclear. Purpose: To (1) examine the associations of Achilles tendon cross-sectional area (CSA) and elongation (TE) during healing of ATR repair with patient outcomes at 12 months postoperatively and (2) investigate the predictive or diagnostic capacity of the morphological biomarkers. Study Design: Cohort study; Level of evidence, 2. Methods: This study was based on previously collected data from 86 patients who underwent acute standardized ATR repair between 2013 and 2018 and who were included in a prior randomized trial investigating early functional mobilization (EFM). In the EFM group, loading was allowed immediately after surgery, while in the comparison group, loading was allowed first at 2 weeks postoperatively. Achilles tendon CSA and length were measured with ultrasound at 6 weeks, 6 months, and 12 months postoperatively. CSA ratio and absolute difference in the length of the healthy and injured tendons were calculated. Patient-reported outcome was registered with the validated Achilles tendon Total Rupture Score and functional outcome with the heel-rise endurance test at 12 months postoperatively. The limb symmetry index (LSI) was calculated for maximum heel-rise height (HRHmax) and total concentric work. Multiple linear regression adjusted for age was used, and the area under the receiver operating characteristic curve (AUC) was calculated to evaluate predictive capacity. Results: A larger CSA ratio at 6 weeks was associated with higher LSI HRHmax at 12 months ( R2, 0.35; P < .001) and exhibited good predictive capacity (AUC, 0.82). More TE at 12 months was associated with lower LSI total concentric work at 12 months ( R2, 0.21; P = .001) and exhibited acceptable predictive capacity (AUC, 0.71). Conclusion: Greater Achilles tendon CSA seen on ultrasound 6 weeks after surgical repair had good clinical prediction for long-term functional outcome. TE at 12 months was predictive of inferior functional outcome. Registration: NCT02318472 (ClinicalTrials.gov identifier).

Measurement of Healthy and Injured Triceps Surae Morphology.

Achilles tendon injuries occur throughout the lifespan and can negatively affect quality of life and overall health. Achilles tendinopathy is generally classified as an overuse injury associated with fusiform tendon thickening, neovascularization, and interstitial tendon degeneration. Current literature suggests these structural changes are associated withsymptoms and lower physical activity levels, as well assymptoms and lower extremity function in the long term. Surgically and non-surgically managed Achilles tendon ruptures result in increased tendon cross-sectional area (CSA) and a lengthened Achilles tendon. Both structural outcomes have clinical implications, as larger CSA positively predicts function, whereas increased tendon lengthening predicts reduced function after Achilles tendon rupture. Given the relationship between structural changes associated with Achilles tendon injuries for both injury severity and injury recovery, it is critical to be able to quantify Achilles tendon structure reliably and accurately. Silbernagel's group has established a valid and reliable method for efficiently evaluating triceps surae muscle and tendon structure. In this protocol, B-mode musculoskeletal ultrasound imaging is used to measure triceps surae structure, including Achilles tendon thickness and CSA, soleus thickness, and the presence of additional findings (calcifications and bursitis). B-mode extended field-of-view is used to measure Achilles tendon length and gastrocnemius anatomical CSA. Finally, power Doppler is used to identify intratendinous neovascularization. Quantification of triceps surae structure allows for comparison between limbs as well as longitudinal changes in response to exercise and treatment for healthy individuals and those with Achilles tendon injuries. This protocol has been used in many research studies to date and proves valuable in understanding the relationship between tendon structure and injury development, severity, and recovery. As ultrasound devices are becoming more affordable and portable, this protocol proves promising as a clinical tool, given its quick and efficient methods.

Morphological study of the popliteus muscle-tendon complex in formalin embalmed adult cadavers

Background: The dimensions of popliteus muscle and its tendon are subjected to variability in the origin, mode of insertion, innervation patterns and vascular supply. The aim of this study was to measure the length, thickness and width of the popliteus muscle and its tendon at its different parts. The objectives were to study the topographic anatomy of the neurovascular structures of the popliteus and also to determine the dimensions of the popliteo-fibular ligament. Methods: This descriptive cross sectional institutional based study included 50 formalin embalmed adult lower limb specimens. The measurements were performed by using the digital Vernier caliper. Results: The length of the popliteus muscle belly along the upper and lower border were 44.2±6.63 mm and 89.26±14.41 mm, width of the muscle belly at midpoint, musculotendinous junction and insertion were 28.45±6.85 mm, 11.7±3.5 mm and 75.95±10.7 mm. The thickness of muscle belly at the midpoint was 2.55±0.55 mm. The length of popliteal tendon, width at origin and at musculotendinous junction were 24.85±2.15 mm, 7.55±1.55 mm and 8.5±1.15 mm. The thickness of tendon of popliteus was 2.6±0.75 mm. The length of nerve to popliteus was 50.44±8.66 mm and its origin was located 27.54±6.18 mm from the intercondylar line. The distance of origin of medial and lateral geniculate arteries from the intercondylar line were 26.26±10.47 mm and 20.76±5.19 mm. The distance of division of popliteal artery was 49.44±16.26 mm from the intercondylar line. The length and width of the popliteo-fibular ligament was 17.84±3.43 mm and 7.36±1.9 mm individually. Conclusions: This study offered detailed morphometric data of the popliteus and it is believed that the data of this anatomical research is enlightening to orthopedic surgeons particularly in the field of arthroscopic and plastic surgery. The data can be considered as the database from our population.

Peroneus tertius revisited: The morphological variability of the bifurcated peroneus tertius insertion – An anatomical study

BackgroundThe peroneus tertius muscle (PT) is one of the extensor muscles of the lower leg, often described as a variable separation from the extensor digitorum longus muscle (EDL). According to literature it has six different types of insertion, one of them (Olewnik Type IV) having two tendons inserting to the fifth metatarsal bone (FMTB). Morphometric data about this type of insertion is sparse, especially the relation between the two tendons, albeit the PT is suspected to contribute to stress fractures of the FMTB. Therefore, we examined this type of insertion to give detailed information on the tendons, the insertion points and the respective relations. MethodsWe examined 27 lower extremities of embalmed human bodies (12 paired, 15 single sided; 12 right and 15 left) with a distinguishable PT with two tendons inserting to the FMTB (Olewnik IV). The specimens were obtained of an undergrad dissection program, which in turn obtained them from a body donation program. After dissection of the PT and photo documentation in situ, resection and measurement of morphological properties of the tendons were performed with the PT attached to the fifth metatarsal bone. ResultsResults of the respective measurements yielded a wide range of variation, especially in the insertion point of the anterior tendon on the fifth metatarsal and the relation between the two tendons, but with no significant difference between sides or sex, except for the length of the posterior tendon between sex. The distance between the base of the FMTB and posterior tendon varies from 0 to 9 mm, with one outlier at 24 mm (mean = 3.9 ± 4.8 mm), the distance between the insertions from 0 to 15 mm (mean = 4.7 ± 4.7 mm), resulting in how far of the FMTB the anterior tendon reaches varying from 17 to 60 mm (mean = 39.6 ± 11.5 mm) or 22–98% (mean = 64 ± 19%). ConclusionOur findings give a detailed overview of the morphological features the PTT can have, when attached with two tendons to the FMTB. Especially the varying relationship between those two insertions and varying point of the anterior insertion are of interest, as they might support its complex role in the occurrence of fractures of the fifth metatarsal by providing different amounts of torsional stress and its tendons can be used as tendon-grafts.

Massive Rotator Cuff Tears With Short Tendon Length Can Be Successfully Repaired Using Synthetic Patch Augmentation.

Choosing the optimal treatment for massive rotator cuff tears (MRCT) still poses a surgical problem. In MRCT with good muscle quality, but short tendon length, non-augmented repairs lead to high failure rates of up to 90%. The aim of the study was to evaluate mid-term clinical and radiological outcomes of massive rotator cuff tears with good muscle quality, but short tendon length, which were repaired with synthetic patch augmentation. A retrospective study of patients who underwent arthroscopic or open rotator cuff repairs with patch augmentation between 2016 and 2019 was performed. We included patients older than 18 years, who presented with MRCT confirmed by an MRI arthrogram showing good muscle quality (Goutallier ≤II) and short tendon length (length <15mm). Constant-Murley score (CS), subjective shoulder value (SSV) and range of motion (ROM) were compared pre- and postoperatively. We excluded patients older than 75 years or with presence of rotator cuff arthropathy Hamada ≥ 2a. Patients were followed up for two years minimum. Clinical failures were defined by re-operation, forward flexion <120 or a relative CS < 70. Structural integrity of the repair was assessed using an MRI. Comparison between different variables and outcomes was performed using Wilcoxon-Mann-Whitney and Chi square tests. Fifteen patients (mean age 57 years, 13 (86.7%) male, 9 (60%) right shoulders) were reevaluated with a mean follow-up of 43.8 months (27-55 months). There was a significant improvement in the absolute CS (from 33 to 81 points, p=0.03), the relative CS (from 41% to 88%, p=0.04), the SSV (from 31% to 93% p=0,007) and forward flexion (from 111° to 163°, p=0.004) but not in external rotation (from 37° to 38°, p=0.5). There were three clinical failures (one atraumatic, two traumatic) with re-operations (two reverse total shoulder arthroplasties and one refixation). Structurally, there were three Sugaya grade 4 and five Sugaya grade 5 re-ruptures resulting in a retear rate of 53%. The presence of a complete or partial re-rupture was not associated with inferior outcomes compared to intact cuff repairs. There were no correlations between the grade of retraction, muscle quality or rotator cuff tear configuration and re-rupture or functional outcomes. Patch augmented cuff repair leads to a significant improvement of functional and structural outcomes. Partial re-ruptures were not associated with inferior functional outcomes. Prospective randomized trials are needed to confirm the results found in our study.

Reconstruction of medial patellofemoral ligament with adductor magnus tendon for recurrent patellar dislocation in children: a retrospective comparative cohort study

BackgroundThe purpose of current retrospective study was to explore the outcomes of using the adductor magnus tendon to reconstruct the medial patellofemoral ligament in the treatment of recurrent patellar dislocation in children.MethodThirty-two children with recurrent patellar dislocation were selected. Sixteen cases in the conservative group, seven males and nine females, with an average age of 11.81 ± 1.28 years; sixteen cases in the surgical group, eight males and eight females, with an average age of 11.56 ± 1.15 years. All patients had no surgery history. The IS index (> 1.2), Q angle (> 20°) and tibial tubercle–femoral trochlear groove (TT–TG) distance (> 20 mm) were measured by X-ray and MRI. The conservative group was treated with closed reduction and a brace, and the surgical group received surgical treatment. Two years after surgery, congruence angle (CA) (− 6° to 6°) and lateral patellofemoral angle (LPFA) (7.7°–18.7°) were measured by X-ray image and all children were evaluated based on Kujala and Lysholm scores. The re-dislocation rate was recorded. Analysis was performed by t test and chi-square with the statistical SPSS software. P < 0.05 was considered a statistically significant difference. Furthermore, we measured the length (mm) of the adductor tendon and MPFL in three knee cadaveric specimens, and also observed the positional relationship between the two structures.ResultThere were no significant differences in sex, age, injury site between groups (P > 0.05). Patients in the two groups were followed up for 2 years in average. Among the 16 cases in the conservative group, 7 cases (43.75%) had recurrence of patellar dislocation, while none of recurrence in the surgical group (P < 0.05). The Lysholm score of the surgical group (94.63 ± 8.99) was significantly better than that of the conservative group (79.31 ± 18.90), and the Kujala score of the surgery group (95.25 ± 10.32) was also significantly better than that of the conservative group (77.06° ± 14.34°) (P < 0.05). The CA and LPFA of the two groups of patients after treatment were significantly recovered. The CA (− 5.81° ± 7.90°) in the surgical group was significantly better than that in the conservative group (20.94° ± 8.21°), and the LPFA (6.44° ± 3.22°) was also significantly better than that in the conservative group (− 9.18 ± 11.08), and the difference is statistically significant (P < 0.05). We found it through autopsy that adductor magnus tendon was 124.33 ± 1.53 mm long, MPFL was 48.67 ± 2.08 mm, and the femoral insertion of the adductor magnus tendon was adjacent to the MPFL femoral insertion.ConclusionReconstruction of Medial patellofemoral ligament with the adductor magnus tendon, fixing with PEEK suture anchors on the patellar side, can achieve satisfactory results in the treatment of children with recurrent patellar dislocation. Compared with conservative treatment, the rate of recurrence is lower and the stability of the patella is better.

Hysteretic performance of prestressed concrete beams with AFRP tendons under cyclic loading

AbstractThis paper aims to evaluate the hysteretic performance of prestressed concrete beams with aramid fiber‐reinforced polymer (AFRP) tendons. Eight beams were constructed and tested under cyclic loading, with test variables covering the type of prestressing tendons (AFRP and steel), the ratio of internal tendons to external tendons (3:0 and 1:2) and the bond condition of internal tendons (fully bonded, partially bonded, and unbonded). Results showed that the failure of all the beams was dominated by concrete crushing and nonprestressed rebars rupturing at pure bending sections. AFRP prestressed beams exhibited commensurate bearing capacity, displacement ductility, energy dissipation and residual deformation with steel prestressed beams. The combination of internal and external tendons, and using unbonded or partially bonded tendons could improve the ductility of AFRP prestressed beams. Additionally, the finite element (FE) models of AFRP prestressed beams were developed using ABAQUS based on the coupling method under the local coordinate system. The simulated results closely matched the experimental results in terms of the failure mode and load–displacement curve. Parametric predictions, including the unbonded length of AFRP tendon, partial prestressing ratio, jacking stress and concrete strength were presented to extend the experimental works.