Tendon Segments Research Articles

A Biomechanical Comparison of Six Suture Configurations for Soft Tissue–Based Graft Traction and Fixation

The purpose of this study was to compare 6 different graft fixation techniques to determine the preparation speed, fixation security, biomechanical strength, and resultant tissue trauma. Six different techniques (10 samples each): #2 OrthoCord Krackow stitch, #2 FiberWire Krackow stitch, SpeedTrap, WhipKnot, Loop-in-loop stitch were created in the distal 3cm of 9cm bovine flexor tendons. The proximal 3cm tendon segment was clamped in a testing machine and the distal suture ends secured by pneumatic grips. 3 preload cycles (10N-100N) and 50N static load was followed by 500 cycles (50N-200N) and then loaded to failure. Graft preparation times, 100 and 500 cycle displacement, maximum failure load, stiffness, and failure mode were recorded. Representative graft preparation times were: OrthoCord Krackow (247s), FiberWire Krackow (401s), FiberLoop (177s), SpeedTrap (42s), WhipKnot (39s), Loop-in-loop (45s). No WhipKnots survived cyclic loading. 100 cycle displacements were: OrthoCord Krackow (11.5 ± 3.9mm), FiberWire Krackow (8.9 ± 1.2mm), FiberLoop (14.2 ± 6.1mm), SpeedTrap (8.8 ± 2.5mm), Loop-in-loop (10.4 ± 2.9mm). FiberLoop displaced significantly more than all others (P= .016). Maximum failure loads were: OrthoCord Krackow (364 ± 24N), FiberWire Krackow (375 ± 45N), FiberLoop (413 ± 95N), SpeedTrap (437 ± 65N), WhipKnot (153 ± 42N), Loop-in-loop (329 ± 112N). The most common failure mode was suture breaking. FiberWire containing constructs (Krackow and FiberLoop) shredded or cut through ("cheese wiring") prior to failure in a majority. SpeedTrap, WhipKnot and Loop-in-loop were quickest to create (under 1minute). The Krackow, SpeedTrap, WhipKnot, and Loop-in-Loop did not damage the tendon during cyclic loading. SpeedTrap and Krackow had the least displacement. FiberLoop displaced more than all other groups (P= .016). No WhipKnot completed cyclic loading. The SpeedTrap (437N) and FiberLoop (413N) had the highest ultimate strength. While the SpeedTrap and FiberLoop are the strongest techniques, the FiberLoop shreds the tendon, displaced the most, and took longer to create. Based on these results, the SpeedTrap demonstrates the best overall performance.

Grayscale ultrasonic and shear wave elastographic characteristics of the Achilles’ tendon in patients with familial hypercholesterolemia: A pilot study

ObjectiveTo investigate the feasibility of grayscale ultrasound and quantitative shear wave elastography (SWE) for assessing the image features and stiffness of the Achilles tendon in patients with familial hypercholesterolemia (FH) compared with healthy controls. MethodsA total of 38 Achilles tendons from healthy control participants and 94 from patients with FH were examined with grayscale ultrasound and SWE. Each Achilles tendon examination was performed on 3 different segments (proximal, middle, and distal). The thickness, grayscale image features and elasticity modulus of each segment was measured on longitudinal views. ResultsIn Achilles tendons of healthy control participants, the thicknesses of the proximal, middle, and distal segments were (4.46 ± 0.68) mm, (5.41 ± 1.01) mm, and (4.41 ± 0.57) mm, respectively. The grayscale features were diffusely hypoechoic with parallel linear hyperechoic striations. The mean elasticity modulus of the proximal, middle, and distal sites was (418.08 ± 43.13) kPa, (425.78 ± 47.14) kPa, and (407.79 ± 38.74) kPa, respectively. In the FH group, the thicknesses of the proximal, middle, and distal segments were (7.65 ± 3.09) mm, (11.46 ± 4.84) mm, and (8.14 ± 2.90) mm, respectively. The grayscale features were hypoechoic with linear hyperechoic disordered fibre distribution (92/94). Two of 94 Achilles tendons had considerable focal hypoechogenicity. Seventeen of 94 Achilles tendons had calcifications. In the FH group, the mean elasticity modulus of the proximal, middle, and distal segments were (294.86 ± 58.13) kPa, (280.93 ± 63.58) kPa, and (282.41 ± 56.47) kPa, respectively. Statistically significant differences were found between the Achilles tendons of healthy control participants and FH patients in the thicknesses and mean elasticity modulus at the proximal, middle and distal segments of the Achilles tendons (all P < 0.001). ConclusionsOur results suggest that the grayscale features and SWE characteristics of the Achilles tendon provided complementary biomechanical information for quantitative assessment the Achilles tendon in patients with FH.

Fully Automatic Finger Extensor Tendon Segmentation in Ultrasound Images of the Metacarpophalangeal Joint.

In this work a fully automatic system to identify the extensor tendon on ultrasound images of the metacarpophalangeal joint is proposed. These images are used to diagnose rheumatic diseases which are one of the main causes of impairment and pain in developed countries. The early diagnosis of these conditions is crucial to a proper treatment and follow-up and so, a system such as the one proposed here, could be useful to automatically extract relevant information from the resulting images. This work is an extension of a previous published work which uses manual annotations of the skin line, metacarpus and phalange to guide the extensor tendon segmentation. By introducing automatic segmentations of all structures, we expect to create a fully automatic system, which is more interesting to the possible end-users. Results show that, despite an expected loss in the performance, it is still possible to correctly identify the extensor tendon with a Confidence of 88% considering a maximum allowed Modified Hausdorff Distance of 0.5mm.

Ex-vivo Tendon Repair Augmented with Bone Marrow Derived Mesenchymal Stem Cells Stimulated with Myostatin for Tenogenesis.

To investigate the effect of myostatin (GDF-8) stimulation of bone marrow derived mesenchymal stem cells (BMSCs) on tenogenesis in the setting of tendon repair. GDF-8 has demonstrated the ability to augment tenogenesis and we sought to identify if this effect could lead to the focused differentiation of pluripotential stem cells down a tenocyte lineage ex vivo. Cadaveric upper limb flexor tendons were harvested, decellularized and divided into 1 cm segments. Sutures seeded with stem cells were passed through tendon segments to simulate repair. The repaired tendons were then cultured either with or without myostatin for 3, 5, and 7 days. The experiment was also repeated with non-decellularized tendons for a total of 4 groups. The tendons were then evaluated for the expression of scleraxis and tenomodulin, two biomarkers for tendon. Myostatin stimulation led to an increase in expression of tenomodulin and scleraxis at 5 and 7 days in both the decellularized and non-decellularized tendons. Myostatin increased the differentiation of BMSCs into tenocytes and/or led to the upregulation of tenomodulin and scleraxis production by the native tenocytes present within the non-decellularized tendons. The addition of myostatin to BMSCs leads to tenocyte differentiation as evidenced by the expression of tenocyte biomarkers, scleraxis and tenomodulin. This effect is maintained in an ex vivo tendon repair model suggestive that these cells survive the passage through tendon tissue and remain metabolically active.

Biomechanical study of different suture methods in repairing tendon rupture

To evaluate the biomechanical property of tendons repaired with the modified Kessler suture combined with " 8" suture, and to provide evidence for the clinical application of this suture methods in repairing acute Achilles tendon rupture. Forty frozen flexor digitorum longus tendons from fresh pork hind leg were randomly assigned into 4 groups, 10 specimens each group. In group A, the tendons were dissected transversely at the midpoint to forming the model of tendon with transversely cutting injury. The tendons in groups B, C, and D were dissected transversely at the midpoint, then a 2 cm segment of tendon from the incision in each side was dissected longitudinally with 1 mm internal to forming " frayed tendon" model. All the tendons were sutured with2-0 non-absorbable suture material with different suturing methods: in group A, the tendons with transversely cutting injury model with Krackow suture, and in the groups B, C, and D with Krackow suture, Kessler suture, and the modified Kessler suture combined with " 8" suture separately. All repaired tendons were fixed onto the biomechanical testing machine. The length, width, and thickness of each side and midpoint of the tendons were recorded, and the cross-sectional area was calculated. The tendons were stretched at a speed of 15 mm/minutes until failure (suture avulsion or rupture). The computer automatically recorded the maximum load, stress, strain, the failure displacement, and the stiffness. These biomechanical parameters of tendons in different groups were analyzed and compared. There was no significant difference in the length and cross-sectional area of each tendon among 4 groups ( F=0.245, P=0.863; F=0.094, P=0.963). Two tendons in group B, 1 in group C, and 1 in group D were excluded because of tendon slipping; all tendons in group A and 8 tendons in group B failured due to suture rupture, 9 tendons in group C due to suture slipping, and 9 tendons in group D due to 3 sutures slipping from tendon tissue together. The maximum load, the maximum stress, the maximum strain, the failure displacement, and the stiffness of the tendons between groups A and B showed no significant difference ( P>0.05). The maximum load, the maximum stress, and the stiffness of the tendons in group D were larger than those in both groups B and C ( P<0.05), but no significant difference was found in the maximum strain and the failure displacement between groups B, C, and D ( P>0.05). The maximum load, the maximum stress, the failure displacement, and the stiffness of the tendons in group B were larger than those in group C ( P<0.05), but the difference of maximum strain between groups B and C was not significant ( P>0.05). The modified Kessler suture combined with " 8" suture can provide better biomechanical property of the repaired tendon compared with other suture approaches.

Ropivacaine alters the mechanical properties of hamstring tendons: In vitro controlled mechanical testing of tendons from living donors

ObjectiveIntraarticular or periarticular injection of ropivacaine (RI) is an element of current knee surgery practices. The goal of this study was to determine the effects of RI on the mechanical properties of hamstring tendons. We hypothesized that RI would have a detrimental effect on the mechanical properties of periarticular soft tissues MethodsA tensile test to failure was performed on 120 hamstring tendon segments harvested during ACL reconstruction surgery in 120 patients. Two sets of tensile tests were done. The first evaluated the effect of RI itself on the mechanical properties of tendons: 30 samples were soaked for 1hour in a 2% RI solution and compared to 30 samples soaked in a saline solution (control group). The second evaluated the effect of RI concentration on the mechanical properties of hamstring tendons: 30 samples were soaked for 1hour in a 2% RI solution and 30 samples were soaked in a 7.5% RI solution. ResultsIn the first test, 29 samples from each group were analyzed as two samples (one in each group) failed at the grip interface. The specimens exposed to 2% RI had lower ultimate tensile strength (Δ=4.4MPa, P=0.001), strain energy (Δ=13MPa, P=0.001) and Young's modulus (Δ=1.6MPa, P=0.02) than the specimens in the control group. There was no significant difference in the strain at failure between groups (Δ=5%, P=0.3). In the second test, one specimen from the 7.5% RI group failed during the preloading and was excluded. There was no significant difference in terms of the load at failure and ultimate tensile stress (Δ=0.45MPa, P=0.6) and strain energy (Δ=0.49MPa, P=0.49) between the two groups. There were significant differences in terms of elongation at failure (Δ=28%, P=0.0003) and Young's modulus (Δ=2.6MPa, P=0.005), with the specimens exposed to 7.5% RI undergoing greater deformation and having a lower Young's modulus. DiscussionWhile local RI injections are widely performed in clinical practice, the results of this in vitro study point to short-term alterations of the mechanical properties of hamstring tendons. If these results hold in vivo, this could lead to weakness of the soft tissues exposed to this product, particularly the tendons and ligaments around the injection area. Level of evidenceExperimental study. Level 1

A New Active Contours Approach for Finger Extensor Tendon Segmentation in Ultrasound Images Using Prior Knowledge and Phase Symmetry.

This work proposes a new approach for the segmentation of the extensor tendon in ultrasound images of the second metacarpophalangeal joint (MCPJ). The MCPJ is known to be frequently involved in early stages of rheumatic diseases like rheumatoid arthritis. The early detection and follow up of these diseases is important to start and adapt the treatments properly and, in that way, preventing irreversible damage of the joints. This work relies on an active contours framework, preceded by a phase symmetry preprocessing and with prior knowledge energies, to automatically identify the extensor tendon. Active contours methods are widely used in ultrasound images because of their robustness to speckle noise and ability to join unconnected smaller regions into a coherent shape. The tendon is formulated as a line so open ended active contours were used. Phase symmetry highlights the tendon, by setting a proper scale range and angle span. The distance between structures and the tendon slope were also included to enforce the model based on anatomical characteristics. And finally, the concavity measures were used because, given the anatomy of the finger, we know that the tendon line should have less than two concavities. To solve the active contours energy minimization a genetic algorithm approach was used. Several energy metric configurations were compared using the modified Hausdorff distance and results showed that this segmentation is not only possible, but exhibits errors smaller than 0.5mm with a confidence of 95% with the phase symmetry preprocessing and energies based on the line neighborhood, area ratio, slope, and concavity measurements.

Experimental Flexor Tendon Healing without Adhesion Formation — A New Concept of Tendon Nutrition and Intrinsic Healing Mechanisms

An experimental model is presented enabling an analysis of the healing process of completely cut and re-sutured free segments of rabbit flexor tendons, kept avascular in a synovial milieu and completely isolated from adhesion formation. Under these conditions the cut tendons heal within a few weeks. It can be shown that this healing process is a result of intrinsic tendon cell activity only.

Tibialis Anterior Tendon Reconstruction Using Augmented Half-Thickness Tendon Segment Transposition.

Therapeutic, Level IV.

A technique for facial reanimation: The partial temporalis muscle-tendon transfer with a fascia lata sling

This report describes the results of a surgical procedure for facial reanimation. This single-stage technique involves the orthodromic transfer of only a superficial segment of the temporalis tendon. This is extended with fascia lata to achieve elevation of the oral commissure along the desired vector in the paralysed hemi-face. A retrospective case note review was performed. Patients' photographs were objectively evaluated with Facial Assessment by Computer Evaluation (FACE) software. Thirty-nine patients underwent the procedure from 2001 to 2011. Median age at the operation was 57.0 years (interquartile range (IQR) 38.2-66.3 years), and median duration of follow-up was 0.9 years (IQR 0.5-1.8 years). All patients achieved early improvements in appearance and function after surgery. Three patients underwent further, minor procedures for aesthetic and functional adjustments around the oral commissure. Complications occurred in three patients: two minor facial haematomas and one thigh wound infection. The surgery did not disturb natural temporalis muscle function. FACE analysis demonstrated that no significant movement of the oral commissure occurred during attempted smiling in the paralysed hemi-face before surgery. However, symmetry was achieved when the healthy and paralysed hemi-faces were compared post-operatively, both in repose and during controlled smiling. This modified, single-stage technique for facial reanimation improves commissure mobilisation and has been objectively shown to restore symmetry of the commissure to the reanimated hemi-face.

Ex vivo Tendon Repair Augmented with Bone Marrow Derived Mesenchymal Stem Cells Stimulated with Myostatin for Tenogenesis: N/A - Not a clinical study

Consulting Fee: Arthrex (Yao) We performed an ex vivo study to investigate the effect of bone marrow derived mesenchymal stem cells (BMSC) stimulated with myostatin on tenogenesis in the setting of tendon repair. We hypothesized that BMSC that were delivered to a tendon repair site after being seeded onto sutures would improve tenogenesis if they were stimulated with myostatin. Cadaveric upper limb flexor tendons were harvested, decellularized, and divided into 1cm segments. Sutures seeded with BMSC were passed through 2 tendon segments to simulate repair. The repaired tendons were then cultured either with or without myostatin for 3, 5, and 7 days. The experiment was also repeated with non-decellularized tendons to make a total of 4 groups. The presence of tenomodulin and scleraxis using immunofluorescence analysis was measured at 3, 5, and 7 days for all 4 groups. Viable BMSC were found at all 3 time points in all 4 groups. Myostatin stimulation lead to expression of tenomodulin and scleraxis at 5 and 7 days in both the decellularized and non-decellularized tendons. In the tendons that were not treated with myostatin, tenomodulin and scleraxis were detected only at day 7 for the decellularized tendons and at days 5 and 7 for the non-decellularized tendons. There were also more cells expressing tenomodulin and scleraxis for the groups treated with myostatin at days 5 and 7. For all 4 groups, no tenomodulin or scleraxis was detected at 3 days. •BMSC delivered to tendon repair sites with sutures can survive for at least 7 days.•There is at least a 3 day delay before the markers of tenogenesis are detectable after BMSC delivery to the tendon repair site.•Myostatin results in an earlier, more robust and sustained expression of tenomodulin and scleraxis in this tendon repair model, implying that it facilitated earlier and increased differentiation of BMSC into tenocytes and/or upregulation of tenomodulin and scleraxis production by the tenocytes present.•Treatment of BMSC with myostatin following their delivery using coated sutures to a tendon repair site may result in improved tenogenesis, implying earlier and better healing of the injured tendon.

Swine small intestine submucosa combined with bone marrow mesenchymal stem cells for repair of Achilles tendon defect in rats: a histological and biomechanical study

Objective To explore the effect of repairing rat Achilles tendon defect with swine small intestine submucosa (SIS) combined with rat bone marrow mesenchymal stem cells (BMSCs). Methods The BMSCs were isolated from Wister fetal bone marrow aspirate and expanded to 5th passage. These P5 BMSCs were incorporated into swine SIS to form a construct. A tendon defect model was created in 54 Wistar rats by removing 0.8 cm segment of the left Achilles tendon. The rats were randomly divided into 3 groups with 18 each. In group A, the tendon defect was repaired with the SIS/BMSC construct. In group B, the defect was repaired with SIS only. In group C, the removed tendon segment was sutured back as an autologous graft. Biomechanical tests and histological examinations were carried out 3, 6 and 9 weeks postoperatively. Results Masson trichrome staining showed gradual increase of type Ⅰ collagen and gradual decrease of type Ⅲ collagen in both group A and B. At 9 weeks postoperatively, type Ⅰ collagen content in group A was significantly higher than in group B (P>0.05), while the content of type Ⅲ collagen was lower in group A than in group B (P>0.05). The content of type Ⅰ and Ⅲ collagen in group A was comparable to that in group C (P>0.05). Biomechanical tests revealed gradual increase in tensile strength of the repair in all 3 groups. At 9 weeks postoperatively the tensile strength in group A was (52.17±2.43) N, being significantly higher than the tensile strength in group B (46.75±2.89) N (P 0.05). Conclusion Swine SIS can be used as a scaffold for xenogenic tendon graft. Combining SIS with host BMSCs can accelerate the engrafting process. Key words: Tissue engineering; Transplantation; Small intestinal submucous; Bone mesenchymal stem cells

The effect of a collagen-elastin matrix on adhesion formation after flexor tendon repair in a rabbit model.

The outcome of flexor tendon surgery is negatively affected by the formation of adhesions which can occur during the healing of the tendon repair. In this experimental study, we sought to prevent adhesion formation by wrapping a collagen-elastin scaffold around the repaired tendon segment. In 28 rabbit hind legs, the flexor tendons of the third and fourth digits were cut and then repaired using a two-strand suture technique on the fourth digit and a four-strand technique on the third digit. Rabbits were randomly assigned to study and control groups. In the control group, the operation ended by closing the tendon sheath and the skin. In the study group, a collagen-elastin scaffold was wrapped around the repaired tendon segment in both digits. After 3 and 8weeks, the tendons were harvested and processed histologically. The range of motion of the digits and the gap formation between the repaired tendon ends were measured. The formation of adhesions, infiltration of leucocytes and extracellular inflammatory response were quantified. At the time of tendon harvesting, all joints of the operated toes showed free range of motion. Four-strand core sutures lead to significantly less diastasis between the repaired tendon ends than two-strand core suture repairs. The collagen-elastin scaffold leads to greater gapping after 3weeks compared to the controls treated without the matrix. Within the tendons treated with the collagen-elastin matrix, a significant boost of cellular and extracellular inflammation could be stated after 3weeks which was reflected by a higher level of CAE positive cells and more formation of myofibroblasts in the αSMA stain in the study group. The inflammatory response subsided gradually and significantly until the late stage of the study. Both the cellular and extracellular inflammatory response was emphasized with the amount of material used for the repair. The use of a collagen-elastin matrix cannot be advised for the prevention of adhesion formation in flexor tendon surgery, because it enhances both cellular and extracellular inflammation. Four-strand core sutures lead to less gapping than two-strand core sutures, but at the same time, the cellular and extracellular inflammatory response is more pronounced.

Biomechanical Strength and Elongation of the T-Block Modification for Bone–Patella Tendon–Bone Allografts

To assess the biomechanical performance of 2 different T-block modifications of bone-patella tendon-bone (BPTB) allografts. The matched knee pairs from 10 human cadavers (mean age 49years) were fashioned into 30 BPTB allografts and divided into 3 groups (10 each): group 1, standard patella tendon-tibial attachment; group 2, T-block tibial attachment with 10mm of unattached bone proximal to the patella tendon insertion with 15mm of tendon attached; group 3, T-block tibial attachment with 15mm of unattached bone proximal to the patella tendon insertion and 10mm of tendon attached. A biocomposite interference screw secured each graft into a 10-mm tunnel in 15 pcf polyurethane foam. A 10-N preload was applied followed by 500 cycles of 10- to 150-N loading at 0.5Hz. Grafts completing cyclic loading were destructively tested at 200mm/min. Failure load, stiffness, elongation, and failure mode were recorded. Failure loads and elongation for groups 1, 2, and 3 (790, 729, and 700N; 0.15, 0.16, and 0.19mm, respectively) were not statistically different (P > .1). Graft stiffness for groups 1 and 2 (214 and 186N/mm) were not statistically different, but group 3 (170N/mm) was different from group 1. All group 1 and 2 tests failed by graft pullout as did 8 of 10 from group 3. The other 2 failed by tendon tearing from bone. A T-block BPTB allograft harvested with 10 or 15mm of unattached bone proximal to the tibial patella tendon insertion has no ultimate failure strength difference after cyclic loading compared with the standard BPTB allograft. The 15-mm T-block showed lower stiffness and more elongation at failure than the standard BPTB allograft whereas the 10-mm T-block exhibited comparable stiffness and elongation measurements to the standard BPTB allograft control specimens. The T-block BPTB allograft construct should increase the availability of BPTB allografts for anterior cruciate ligament reconstruction and facilitate the use of grafts possessing longer tendon segments that are currently being discarded.

English

BACKGROUND: Tendoachillis injuries in western patients are mainly due to sports injury. Where as in our country it is mainly due to injury in lavatory pan, road traffic accidents and direct cut injury. Pattern of injury varies and so also the method of reconstruction. We here represent a prospective study of various type of tendoachillis injury, different methods of reconstruction, associated complications and functional outcome. MATERIAL AND METHOD: A prospective study was done in M.K.C.G hospital Berhampur, Orissa from July 2013 to January 2015. A Total of 30 patients of tendoachillis injuries were included in our study. Patients were classified in to different groups depending upon nature of tendoachillis injury i.e. with or without skin loss, with or without segmental loss of tendoachillis, number of skin laceration (Single or multiple) and with or without avulsion fracture of calcaneum. Most of the patients without skin loss were treated in emergency department and all the patients with skin loss and with segmental loss of tendon were admitted to the hospital. Patients with simple laceration of tendoachillis were by repaired by prolene 1-0 and stainless steel wire. Patients with segmental loss of tendoachillis were repaired with proximal segment of tendon which was reversed upside down 180 degrees (Bosworth Technique). Skin loss were managed with peroneal perforator based distal fasciocutaneous flap, islanded reverse sural flap and cross leg flap as indicated in particular patients. All the patients were managed as per the same post-operative protocol. Patients were followed up from a minimum of 6 month to 2 year. Early and late complications were observed. RESULT: In patients without skin loss most common complications were prolene granuloma and sinus mainly related to material used for repair i.e. prolene. In patients with skin loss complications were related to flaps used for reconstruction like partial flap loss, total flap loss, flap dehiscence, infection, seroma, marginal skin necrosis. All the patients regained normal range of plantar flexion and dorsi flexion. CONCLUSION: TA tendon injury with segmental loss of tendon associated skin loss can effectively be managed by proper selection of reconstructive methods to give good functional results. INTRODUCTION: Tendoachillis due to its definite pattern of blood supply and situation in the distal third of the leg poses technical challenge to the surgeon for successful repair. Complicated injury to TA in road traffic accidents increases the challenge of reconstruction. Injury to tendoachillis in presence of trauma particularly in road traffic accidents increases the chance of infection and contamination. In western countries tendoachillis is mainly injured due to sports injury and steroid use. In India the most common mechanism of injury is trauma and assault. We have encountered various pattern of injury to TA tendon in southern part of Orissa.

Regional mechanical properties of the long head of the biceps tendon

BackgroundLong head of the biceps tenodesis reliably relieves pain, and restores strength, stability, and normal appearance of the upper extremity in the event of biceps tendinopathies. Regional differences in tendon mechanics may provide surgeons with valuable guidance in the placement of the tenodesis repair construct. The purpose of this study was to compare the mechanical properties of the long head of the biceps tendon in three functional regions of the tendon: intra-articular (proximal), suprapectoral (middle), and subpectoral (distal). MethodsUniaxial tensile tests were performed on the long head of the biceps tendon segments to quantify the material and structural properties of the tendon. Material properties were obtained using dogbone-shaped specimens while structural properties were obtained using intact specimens where the clamp boundary conditions simulated the common “gold standard” tenodesis, the interference screw. FindingsElastic modulus for the supra- and subpectoral regions were significantly greater than the intra-articular region (P≤0.048). The tensile strength of the subpectoral region tended to be lower compared to all other functional regions (P=0.051). The failure mechanism for intact specimens was similar to that seen for interference screw fixation where tissue failure occurs due to tearing at the bone/tendon/screw interface. InterpretationThe higher tensile strength of the suprapectoral region compared to the subpectoral region may make this a more desirable location for tenodesis placement based on tissue strength. Similar elastic moduli and structural stiffness between the supra- and subpectoral regions indicate that the construct type may play a bigger role in functional outcomes in relation to construct deformation.

Employment of synthetic patch with augmentation of the long head of the biceps tendon in irreparable lesions of the rotator cuff: our technique applied to 60 patients.

The aim of our study was to evaluate the effectiveness of both clinical and functional benefits after the surgical repair of the rotator cuff in irreparable lesions using a synthetic patch with augmentation of the long head of the biceps (LHB) tendon. This is a retrospective study analysis of a randomized series of 60 patients (45 women and 15 men; average age 66 y) who underwent open repair of irreparable rotator cuff tear with synthetic patch using LHB tendon augmentation between 1999 and 2008.The inclusion criteria were: patients painful symptomatology, presenting a deficit in elevation, who are not responsive to physiotherapy, irreparable tear size, minimum follow-up of 36 months after surgery, and active and motivated patients. We used a control group of 60 patients treated without employment of the synthetic patch and LHB tendon augmentation.Patients were evaluated preoperatively and after 36 months with a Visual Analog Scale (VAS) and the University of California, Los Angeles (UCLA) shoulder rating scale and by measuring elevation of the scapular plane and strength with a dynamometer. All the patients were assessed preoperatively also with plain radiographs (anteroposterior and axillary views), ultrasound, and NMRI of the shoulder. The VAS and UCLA scores were also obtained 3 months postoperatively. Tendon integrity was assessed after 1 year by NMRI. Statistical analysis was conducted by 1-way analysis of variance between groups of treatment, with Dunnett post hoc correction for multiple comparisons. P-values ≤ 0.05 were considered as statistically significant. This surgical technique consisted in a short deltoid splitting, irreparable lesion evaluation, and, after tenodesis, the proximal segment of the LHB tendon was sutured to the remaining cuff tendons to fill the gap of the corresponding lesion. To shield the repaired rotator cuff we inserted a synthetic patch. Satisfactory results were achieved in 52 of the patients treated with this procedure; after 3 months the mean VAS was 6.85 ± 1.11 versus 4.9 ± 0.9, whereas the mean UCLA was 11.28 ± 1.43 versus 20.85 ± 1.27, respectively, for control and prolene group. After 36 months the mean VAS was 3.7 ± 1.01 versus 3.23 ± 1.07, whereas the mean UCLA was 14.73 ± 1.96 versus 24.6 ± 3.3, respectively, for control and prolene group. In addition, after 36 months elevation on the scapular plane was 140.75 ± 10.48 degrees versus 174.75 ± 8.1 degrees and abduction strength was 8.57 kg ± 0.63 versus 13.61 kg ± 0.84, respectively, for control and prolene group (P-value = 0.005). Re-tear rate after 12 months was 40% (24/60) in the control group and 15% (9/60) in the prolene group. No adverse side effects (infection, rejection, allergy) were reported during the study period. The results of our study suggest that employing this surgical technique in patients (appropriately selected) with an irreparable rotator cuff tear can lead to pain relief and improved clinical outcome.

Musculoskeletal integration at the wrist underlies the modular development of limb tendons.

The long tendons of the limb extend from muscles that reside in the zeugopod (arm/leg) to their skeletal insertions in the autopod (paw). How these connections are established along the length of the limb remains unknown. Here, we show that mouse limb tendons are formed in modular units that combine to form a functional contiguous structure; in muscle-less limbs, tendons develop in the autopod but do not extend into the zeugopod, and in the absence of limb cartilage the zeugopod segments of tendons develop despite the absence of tendons in the autopod. Analyses of cell lineage and proliferation indicate that distinct mechanisms govern the growth of autopod and zeugopod tendon segments. To elucidate the integration of these autopod and zeugopod developmental programs, we re-examined early tendon development. At E12.5, muscles extend across the full length of a very short zeugopod and connect through short anlagen of tendon progenitors at the presumptive wrist to their respective autopod tendon segment, thereby initiating musculoskeletal integration. Zeugopod tendon segments are subsequently generated by proximal elongation of the wrist tendon anlagen, in parallel with skeletal growth, underscoring the dependence of zeugopod tendon development on muscles for tendon anchoring. Moreover, a subset of extensor tendons initially form as fused structures due to initial attachment of their respective wrist tendon anlage to multiple muscles. Subsequent individuation of these tendons depends on muscle activity. These results establish an integrated model for limb tendon development that provides a framework for future analyses of tendon and musculoskeletal phenotypes.

Curvelet based automatic segmentation of supraspinatus tendon from ultrasound image: a focused assistive diagnostic method.

BackgroundDisorders of rotator cuff tendons results in acute pain limiting the normal range of motion for shoulder. Of all the tendons in rotator cuff, supraspinatus (SSP) tendon is affected first of any pathological changes. Diagnosis of SSP tendon using ultrasound is considered to be operator dependent with its accuracy being related to operator’s level of experience.MethodsThe automatic segmentation of SSP tendon ultrasound image was performed to provide focused and more accurate diagnosis. The image processing techniques were employed for automatic segmentation of SSP tendon. The image processing techniques combines curvelet transform and mathematical concepts of logical and morphological operators along with area filtering. The segmentation assessment was performed using true positives rate, false positives rate and also accuracy of segmentation. The specificity and sensitivity of the algorithm was tested for diagnosis of partial thickness tears (PTTs) and full thickness tears (FTTs). The ultrasound images of SSP tendon were taken from medical center with the help of experienced radiologists. The algorithm was tested on 116 images taken from 51 different patients.ResultsThe accuracy of segmentation of SSP tendon was calculated to be 95.61% in accordance with the segmentation performed by radiologists, with true positives rate of 91.37% and false positives rate of 8.62%. The specificity and sensitivity was found to be 93.6%, 94% and 95%, 95.6% for partial thickness tears and full thickness tears respectively. The proposed methodology was successfully tested over a database of more than 116 US images, for which radiologist assessment and validation was performed.ConclusionsThe segmentation of SSP tendon from ultrasound images helps in focused, accurate and more reliable diagnosis which has been verified with the help of two experienced radiologists. The specificity and sensitivity for accurate detection of partial and full thickness tears has been considerably increased after segmentation when compared with existing literature.

A Simple Technique for Repair of Chronic Tendinopathy

A large number of tendon repair techniques have been described for acute tendon injury. However, after reviewing the literature, it was noted that there were limited descriptions of specific suture techniques that address repair processes of chronic tendon pathology. Generally, in chronic tendinopathy, others have described a process known as tendon tubularization, which consists of a running stitch using a nonabsorbable suture material along the external surface of the tendon. We believe that leaving a nonabsorbable suture on the exterior surface of the tendon in this manner has the potential to disrupt the optimal gliding function. Furthermore, because additional damage could be present within the body of the tendon, this form of repair might not prove adequate to optimally appose the disrupted tendon segments internally. We have described a simple technique to repair chronic tendon injury from “the inside-out.” We believe this approach provides better augmentation of tendon strength and eliminates the nonabsorbable suture along the exterior surface of the tendon.