Tendinopathy Research Articles

Assessing the effects of intratendinous genipin injections: Mechanical augmentation and spatial distribution in an ex vivo degenerative tendon model.

BackgroundTendinopathy is a common musculoskeletal disorder and current treatment options show limited success. Genipin is an effective collagen crosslinker with low cytotoxicity and a promising therapeutic strategy for stabilizing an intratendinous lesion.PurposeThis study examined the mechanical effect and delivery of intratendinous genipin injection in healthy and degenerated tendons.Study designControlled laboratory studyMethodsBovine superficial digital flexor tendons were randomized into four groups: Healthy control (N = 25), healthy genipin (N = 25), degenerated control (N = 45) and degenerated genipin (N = 45). Degeneration was induced by Collagenase D injection. After 24h, degenerated tendons were subsequently injected with either 0.2ml of 80mM genipin or buffer only. 24h post-treatment, samples were cyclically loaded for 500 cycles and then ramp loaded to failure. Fluorescence and absorption assays were performed to analyze genipin crosslink distribution and estimate tissue concentration after injection.ResultsCompared to controls, genipin treatment increased ultimate force by 19% in degenerated tendons (median control 530 N vs. 633 N; p = 0.0078). No significant differences in mechanical properties were observed in healthy tendons, while degenerated tendons showed a significant difference in ultimate stress (+23%, p = 0.049), stiffness (+27%, p = 0.037), work to failure (+42%, p = 0.009), and relative stress relaxation (-11%, p < 0.001) after genipin injection. Fluorescence and absorption were significantly higher in genipin treated tendons compared to control groups. A higher degree of crosslinking (+45%, p < 0.001) and a more localized distribution were observed in the treated healthy compared to degenerated tendons, with higher genipin tissue concentrations in healthy (7.9 mM) than in degenerated tissue (2.3 mM).ConclusionUsing an ex-vivo tendinopathy model, intratendinous genipin injections recovered mechanical strength to the level of healthy tendons. Measured by genipin tissue distribution, injection is an effective method for local delivery.Clinical relevanceThis study provides a proof of concept for the use of intratendinous genipin injection in the treatment of tendinopathy. The results demonstrate that a degenerated tendon can be mechanically augmented by a clinically viable method of local genipin delivery. This warrants further in vivo studies towards the development of a clinically applicable treatment based on genipin.

The Effectiveness of Autologous Whole Blood Injection in the Treatment of Tendinopathy

A comprehensive search to identify randomized controlled trials and case control studies on the subject of autologous whole blood injections (ABI) for tendinopathy. For example subacromial impingement, rotator cuff tendinopathy, tennis elbow, golfers elbow, patella tendonitis, Achilles tendonitis and plantar fasciitis.

Functional Outcome at Short and Middle Term of the Extracorporeal Shockwave Therapy Treatment in Lateral Epicondylitis: A Case-Series Study.

Lateral epicondylitis (LE) of the humerus is a chronic degeneration of wrist extensor tendons at their attachments to the lateral epicondyle of the humerus. There is not a common consensus on a specific therapeutic algorithm, but Extracorporeal Shockwave Therapy (ESWT) is widely used. The purpose of this study is to evaluate the clinical benefits of low dose ESWT in LE-affected patients in short and medium follow-up. Between January 2015 and December 2017, 60 patients (38 male, mean age 52.2 ± 10.1 years, the duration of the disease was 3.6 ± 1.3 months) were clinically evaluated using visual analog scale (VAS) and Patient Rated Tennis Elbow Evaluation Test (PRTEE-I) scores before treatment, at one, three, six and 12 months after treatment. According to the VAS and PRTEE-I scoring systems, all patients achieved an improvement of pain and functional outcome comparing the baseline results with one, six and 12 months values. Low dose ESWT is a safe and effective treatment of LE in the short and middle term. In elderly subjects, patients with a long disease history, or those with occupational and sportive risk factors, a longer persistence of the symptomatology could be observed.

Nouveaux facteurs prédictifs de la rupture du subscapulaire : angle de coraco-petite tubérosité humérale, angle et hauteur de la tubérosité inférieure

BackgroundThe pathogenesis of degenerative subscapularis (SC) tear is not clear, several mechanisms are involved: intrinsic tendon degeneration or subcoracoid impingement. The aim of this study was to propose new radiographic markers, the coraco-lesser tuberosity angle (CLA), lesser tuberosity angle (LTA) and lesser tuberosity height (LTH). The hypothesis was that higher values of CLA, LTA, and LTH would be associated with a higher likelihood in detecting a SC tear. MethodA total of 114 patients who classified as SC tears through arthroscopic evaluation were retrospectively enrolled in the study from 2016 to 2018. Fifty-seven patients with impingement syndrome were also enrolled as the control group for normal-population comparison. The CLA was measured on an anteroposterior shoulder x-ray image with the arm in neutral rotation, the LTA and LTH were measured on magnetic resonance imaging. Multivariable analyses were used to clarify the potential risks for SC tears. All measurements were calculated by two shoulder surgeons independently measured at 2 different times, 1 month apart. ResultsThe intra- and inter-observer reliabilities for radiologic measurements and the interobserver reliability of SC tear classification were almost perfect. The mean CLA value of SC tear group (41.4±4.2°) was significantly larger than that of the control group (38.7±4.0°, p<0.001). The mean LTA value of SC tear group (33.4±4.3°) was significantly larger than that of the control group (31.0±3.9°, p=0.001). Mean LTH value was 9.5±1.9mm in patients and 8.9±1.5mm for controls, there was no statistically significant difference (p=0.054). Multivariable analysis showed that larger CLAs significantly increased the risk of SC tears, with odds ratios of 1.17 per degree. Moreover, larger LTAs also significantly increased the risk of SC tears, with odds ratios of 1.14 per degree. ConclusionOur findings confirmed associations between new predictors (CLA and LTA) and SC tears. CLA and LTA values were greater in patients with SC tears than in controls, suggesting that they may be independent risk factors for SC tear onset. Level of evidenceLevel IV, retrospective study.

Arthroscopic Rotator Cuff Repair: Double Row Suture Bridge Technique (About 50 Cases)

Rotator cuff tear occurs in young adults as a result of degenerative and/or traumatic tendon pathology. This retrospective study presents outcomes in 50 patients who had undergone arthroscopic rotator cuff repair. This work has shown that the double row suture bridge technique seems to be more anatomical. By applying the tendon on the previously prepared footprint which is located in the greater tuberosity and thus restoring the tendons to their approximate premorbid positions, which significantly improves the patient’s quality of life.

Therapeutic Efficacy of Intratendinous Delivery of Dexamethasone Using Porous Microspheres for Amelioration of Inflammation and Tendon Degeneration on Achilles Tendinitis in Rats.

Achilles tendinitis caused by overuse, aging, or gradual wear induces pain, swelling, and stiffness of Achilles tendon and leads to tendon rupture. This study was performed to investigate the suppression of inflammation responses in interleukin-1β- (IL-1β-) stimulated tenocytes in vitro and the suppression of the progression of Achilles tendinitis-induced rat models in vivo using dexamethasone-containing porous microspheres (DEX/PMSs) for a sustained intratendinous DEX delivery. DEX from DEX/PMSs showed the sustained release of DEX. Treatment of IL-1β-stimulated tenocytes with DEX/PMSs suppressed the mRNA levels for COX-2, IL-1β, IL-6, and TNF-α. The intratendinous injection of DEX/PMSs into Achilles tendinitis rats both decreased the mRNA levels for these cytokines and increased mRNA levels for anti-inflammatory cytokines IL-4 and IL-10 in tendon tissues. Furthermore, DEX/PMSs effectively prevented tendon degeneration by enhancing the collagen content and biomechanical properties. Our findings suggest that DEX/PMSs show great potential as a sustained intratendinous delivery system for ameliorating inflammation responses as well as tendon degeneration in Achilles tendinitis.

Three-dimensional self-assembling nanofiber matrix rejuvenates aged/degenerative human tendon stem/progenitor cells

The poor healing capacity of tendons is known to worsen in the elderly. During tendon aging and degeneration, endogenous human tendon stem/progenitor cells (hTSPCs) experience profound pathological changes. Here, we explored a rejuvenation strategy for hTSPCs derived from aged/degenerated Achilles tendons (A-TSPCs) by providing three-dimensional (3D) nanofiber hydrogels and comparing them to young/healthy TSPCs (Y-TSPCs). RADA peptide hydrogel has a self-assembling ability, forms a nanofibrous 3D niche and can be further functionalized by adding RGD motifs. Cell survival, apoptosis, and proliferation assays demonstrated that RADA and RADA/RGD hydrogels support A-TSPCs in a comparable manner to Y-TSPCs. Moreover, they rejuvenated A-TSPCs to a phenotype similar to that of Y-TSPCs, as evidenced by restored cell morphology and cytoskeletal architecture. Transmission electron, confocal laser scanning and atomic force microscopies demonstrated comparable ultrastructure, surface roughness and elastic modulus of A- and Y-TSPC-loaded hydrogels. Lastly, quantitative PCR revealed similar expression profiles, as well a significant upregulation of genes related to tenogenesis and multipotency. Taken together, the RADA-based hydrogels exert a rejuvenating effect by recapitulating in vitro specific features of the natural microenvironment of human TSPCs, which strongly indicates their potential to direct cell behaviour and overcome the challenge of cell aging and degeneration in tendon repair.

The acromion-greater tuberosity impingement index: A new radiographic measurement and its association with rotator cuff pathology.

Several radiographic parameters describe humeral head coverage by the acromion. We describe a new radiographic measurement, the acromion-greater tuberosity impingement index (ATI), and its ability to predict rotator cuff pathology. The ATI was measured with magnetic resonance imaging (MRI) and X-ray analysis in 83 patients with rotator cuff pathology and 76 patients with acute rotator cuff tears. The lateral acromial angle (LAA), acromion type, the acromion index (AI) and the critical shoulder angle (CSA) were measured to assess their correlations with the ATI. Receiver operating characteristic (ROC) curves were used to predict degenerative rotator cuff pathology. The change in the ATI after acromion surgery was evaluated in both groups. According to the ROC curves, the ATI is a good predictor of degenerative rotator cuff pathology on both X-ray (cut-off, 0.865) and MRI (cut-off, 0.965). Patients with degenerative rotator cuff pathology had a significantly higher average ATI compared to the trauma group (p = 0.001 for X-ray and MRI). The degenerative group had a significantly lower LAA (p = 0.001) and a higher ratio of type III acromion (p = 0.035) than the trauma group. The ATI on X-ray was negatively related to the LAA and positively related to the AI, the CSA and acromion type (each p < 0.05). The ATI on MRI was negatively related to the LAA and positively related to the AI and acromion type (each p <0.05). More patients in the degenerative group than the trauma group needed acromioplasty or acromion decompression (p < 0.05). The ATI on MRI was significantly lower after acromion surgery compared to before surgery in both groups (p < 0.05). The ATI is a good predictor of degenerative supraspinatus tendon tears or subacromial impingement syndrome. The ATI on MRI is more accurate and can precisely guide acromion surgery.

Hronična parcijalna ruptura Ahilove tetive - transfer tetive flexor hallucis longus - prikaz dva slučaja

Achilles tendon injuries most commonly occur in athletes, but also in the middle-aged population practicing recreational sports. The aetiology of injury and disease of the Achilles tendon has not been completely clarified. While acute injury can be attributed to trauma, research showed that a chronic degenerative process is present in most ruptures. While there are still a lot of dilemmas when it comes to treating acute rupture, chronic rupture and disease are predominantly treated operatively. Many operative procedures can be used when treating chronic Achilles tendon diseases, such as excision of degenerative changes and tendon decompression, reconstruction using fascia lata and VY plastics, tendon transfer (Flexor Hallucis Longus - FHL, Flexor Digitorum Longus - FDL, Peroneus Brevis - PB) and allograft and synthetic graft reconstruction. The objective of the paper was to present the results of treating chronic partial Achilles tendon rupture by scar excision and FHL tendon transposition. The patients were one professional and one recreational athlete, both of whom were treated nonoperatively for a long time. They were both tested using AOFAS and ATRS tests preoperatively and postoperatively. The results showed a significant improvement of function and both patients were able to return to their usual activities. Postoperative results of AOFAS and ATRS tests were almost identical to the result on the uninjured leg. Our little series, as well as a lot of research performed by other authors, shows that an FHL tendon transposition is a safe and efficient method in treating diseases and injuries of the Achilles tendon.

Magnetic resonance imaging of the ankle and foot.

This article reviews the magnetic resonance imaging (MRI) findings of the normal anatomy and various pathologic conditions of the ankle and foot commonly encountered in clinical practice. The spectrum of entities discussed includes osseous and osteochondral injuries, ligamentous injuries, common traumatic and degenerative tendon pathology, abnormalities of transverse tarsal joint (Chopart) and tarsometatarsal joint (Lisfranc) complexes, pathological conditions affecting capsuloligamentous structures of the great toe and lesser toes, as well as pedal infection, with a focus on diabetic osteomyelitis and neuropathic osteoarthropathy.

Advanced diagnostic imaging and intervention in tendon diseases.

Degenerative tendon pathology represents one of the most frequent and disabling musculoskeletal disorders. Diagnostic radiology plays a fundamental role in the clinical evaluation of tendon pathologies. Moreover, several minimally invasive treatments can be performed under imaging guidance to treat tendon disorders, maximizing the efficacy and reducing procedural complications. In this review article we describe the most relevant diagnostic features of conventional and advanced US and MRI imaging in tendon disorders, along with the main options for image-guided intervention. (www.actabiomedica.it)

Could the tendon degeneration and the fatty infiltration of the gluteus medius affect clinical outcome in total hip arthroplasty?

The aim of this prospective study was to perform a clinical and radiologic evaluation of patients undergoing total hip arthroplasty (THA). The hypothesis is that there is a correlation between the pre-operative degeneration state of the gluteal muscle-tendinous unit and the clinical outcome in terms of functional recovery. Fifty-five patients have met inclusion criteria. All patients included in the sample were subjected to clinical evaluation. The ultrasound examination of the patients of the study was conducted and the following parameters were assessed: Thickness in mm of the gluteus medius tendon; Quality of the gluteus medius tendon; and Trophy and muscular composition. The degree of degeneration of the pre-operative tendon shows a negative statistical correlation with all the pre- and post-operative clinical scales, but presents statistical significance (p < 0.05) only with the post-operative Harris, the post-operative Oxford, the Harris and HOOS-modified post-operative, lameness, and Trendelenburg; it correlates positively with the quality of the macroscopic tendon detected intra-operatively, the degree of the pre-operative contralateral tendon, and the operated and contralateral pre-operative muscle (p < 0.05). The degree of fatty degeneration of the pre-operatively operated muscle correlates negatively (p < 0.05) with all pre- and post-operative clinical scales except for the pre-operative WOMAC and HOOS modified, with the lameness and the Trendelenburg sign; it correlates positively (p < 0.05) with age, the quality of the macroscopic tendon detected intra-operatively, degree of tendon degeneration, fatty infiltration of the contralateral pre- and post-operative muscle and of the post-operative operated muscle. Tendon degeneration and fatty infiltration of the gluteus medius muscle appeared to be determinants of the post-operative persistence of lameness and Trendelenburg sign positivity in patients undergoing hip arthroplasty.

New predictors for subscapularis tear: Coraco-lesser tuberosity angle, lesser tuberosity angle, and lesser tuberosity height

BackgroundThe pathogenesis of degenerative subscapularis (SC) tear is not clear, several mechanisms are involved: intrinsic tendon degeneration or subcoracoid impingement. The aim of this study was to propose new radiographic markers, the coraco-lesser tuberosity angle (CLA), lesser tuberosity angle (LTA) and lesser tuberosity height (LTH). The hypothesis was that higher values of CLA, LTA, and LTH would be associated with a higher likelihood in detecting a SC tear. MethodA total of 114 patients who classified as SC tears through arthroscopic evaluation were retrospectively enrolled in the study from 2016 to 2018. Fifty-seven patients with impingement syndrome were also enrolled as the control group for normal-population comparison. The CLA was measured on an anteroposterior shoulder x-ray image with the arm in neutral rotation, the LTA and LTH were measured on magnetic resonance imaging. Multivariable analyses were used to clarify the potential risks for SC tears. All measurements were calculated by two shoulder surgeons independently measured at 2 different times, 1 month apart. ResultsThe intra- and inter-observer reliabilities for radiologic measurements and the interobserver reliability of SC tear classification were almost perfect. The mean CLA value of SC tear group (41.4±4.2°) was significantly larger than that of the control group (38.7±4.0°, p<0.001). The mean LTA value of SC tear group (33.4±4.3°) was significantly larger than that of the control group (31.0±3.9°, p=0.001). Mean LTH value was 9.5±1.9mm in patients and 8.9±1.5mm for controls, there was no statistically significant difference (p=0.054). Multivariable analysis showed that larger CLAs significantly increased the risk of SC tears, with odds ratios of 1.17 per degree. Moreover, larger LTAs also significantly increased the risk of SC tears, with odds ratios of 1.14 per degree. ConclusionOur findings confirmed associations between new predictors (CLA and LTA) and SC tears. CLA and LTA values were greater in patients with SC tears than in controls, suggesting that they may be independent risk factors for SC tear onset. Level of evidenceIV, retrospective study.

Localized Rotator Cuff Tendon Degeneration for Cadaveric Shoulders with and Without Tears Isolated to the Supraspinatus Tendon.

Localized differences in tissue degeneration throughout intact and torn rotator cuff tendons have not been well quantified. The objective of this study was to investigate histological differences in localized degeneration in tendons with and without rotator cuff tears isolated to the supraspinatus tendon. Four intact shoulders and four shoulders with rotator cuff tears isolated to the supraspinatus tendon were dissected down to the infraspinatus and supraspinatus tendons. Biopsies were taken throughout the tendon insertion, mid-substance, myotendinous junction, and around the tear if present. Samples were stained with hematoxylin and eosin and tendon degeneration was graded based on collagen fiber organization, nuclei shape, cellularity, and lipoid degeneration. Comparisons in degeneration parameters were made based on the tendon type (supraspinatus vs. infraspinatus), location within the tendon, and presence of a tear. Supraspinatus tendons exhibited more degeneration than the infraspinatus tendon (P < 0.05). Significant increases in lipoid degeneration were found near the myotendinous junction compared to the rest of the tendon (P < 0.001). Tendons with rotator cuff tears showed greater amounts of lipoid degeneration compared to intact tendons (P = 0.03). A strong negative correlation was found between lipoid degeneration and collagen fiber organization (r = -0.922, P = 0.001). No differences in degeneration were found between medial, anterior, and posterior edges of the tear. The study highlights specific factors of tendon degeneration contributing to the local differences in tendon degeneration. By understanding local differences in tendon degeneration, surgical protocols for repair can be improved. Clin. Anat., 33:1007-1013, 2020. © 2019 Wiley Periodicals, Inc.

Patellar Tendon Lengthening: Rescue Procedure for Patella Baja

Patella baja is a challenging pathologic condition that causes pain and functional restrictions and can even lead to premature osteoarthritis—even more so in cases of patella infera or cases associated with degeneration of the patellar tendon in which simple conservative treatment frequently is not resolutive. Several surgical options have been described for symptomatic patella baja: excision of the lower third of the patella, lengthening of the patellar tendon, reconstruction of the patellar tendon with allograft, and proximalization of the tibial tubercle. A combination of 2 or more of these treatments may be recommended in cases of significant patella baja. We present a simple and reproducible technique to address patella baja that combines a partial transposition of the tibial tubercle and patellar tendon lengthening using a subperiosteal patellar flap in continuity with the patellar tendon.

Suprascapular nerve neuropathy leads to supraspinatus tendon degeneration

BackgroundNowadays most of attention regarding rotator cuff is payed to how to reduce the failure after rotator cuff surgical repair rather than how to prevent the rotator cuff tear before surgery. The etiologies of rotator cuff tear are still unclear. As we all know, the nerve system include brain, spinal cord, sensory organs and all the neurons allover our body coordinates the homoeostasis of our body. We hypothesis that the nerve injury proximal to suprascapular nerve can leads to rotator cuff degeneration even tear. MethodsThirty-six SD rats were used. A defect on the suprascapular nerve was made on the right side and a sham surgery on the nerve (expose nerve only) at the left side. The insertion of supraspinatus tendon and supraspinatus muscle were harvested for testing. Twelve rats were sacrificed for biomechanical (six rats) and histological (six rats) properties were evaluated at 3, 6, and 9 weeks after surgery, respectively. ResultsSignificant inferior biomechanical properties of rotator cuff were found in nerve injured side compared to the nerve intact side at 6–9 weeks. Significant muscle atrophy was found at nerve injured side from 3 to 9 weeks. The enthesis of nerve injured side showed significant excessive cell maturity, reduced cellularity, smaller metachromasia area and more type-III collagen especially at 9 weeks after surgery. ConclusionsThe neuropathy proximal to suprascapular nerve can leads to rotator cuff degeneration even tear. The nerve dysfunction maybe an important etiology for rotator cuff tear.

PO 18221 - Minimally invasive treatment of acute Achilles tendon injuries with flexor hallucis longus tendon augmentation assisted by posterior ankle arthroscopy

Introduction: Achilles tendon ruptures cause significant functional limitations. The treatment for acute injury is controversial; conservative or surgical treatment and open or minimally invasive surgery are available options. The objective of this study is to evaluate the clinical and functional outcomes of patients with acute Achilles tendon rupture treated with minimally invasive tendon repair and augmentation with flexor hallucis longus tendon transfer assisted by posterior ankle arthroscopy. Methods: A retrospective, cross-sectional and observational study in which 5 patients with more than 24 months of postoperative follow-up were evaluated using the American Orthopedic Foot and Ankle Society (AOFAS) score, the Victorian Institute of Sport Assessment-Achilles (VISA-A), the Achilles Tendon Total Rupture Score (ATRS), the pain visual analog scale (VAS), and assessments of range of motion and strength. Results: The mean scores on the following instruments were obtained: pain VAS: 0.6; AOFAS: 98; VISA-A: 98.2 and ATRS: 100. The mean dorsiflexion range of motion was smaller (4.8º) than the contralateral range of motion (7.6º). The mean plantar flexion strength was 24.02 kgf on the operated side and 24.64 kgf on the contralateral side. The flexion strength of the hallux interphalangeal joint was weaker on the operated side (13.94 kgf) than on the contralateral side (17.6 kgf), albeit with no complaints from the patients. Conclusion: The proposed surgical treatment method had good clinical and functional outcomes among the patients evaluated in this study. The surgical technique presented herein may be a good alternative for the treatment of uncooperative patients diagnosed with acute Achilles tendon rupture due to tendinosis with important tendon degeneration.

Patellar tendon morphology in trans-tibial amputees utilizing a prosthesis with a patellar-tendon-bearing feature

A patellar-tendon-bearing (PTB) bar is a common design feature used in the socket of trans-tibial prostheses to place load on the pressure-tolerant tissue. As the patellar tendon in the residual limb is subjected to the perpendicular compressive force not commonly experienced in normal tendons, it is possible for tendon degeneration to occur over time. The purpose of this study was to compare patellar tendon morphology and neovascularity between the residual and intact limbs in trans-tibial amputees and healthy controls. Fifteen unilateral trans-tibial amputees who utilized a prosthesis with a PTB feature and 15 age- and sex- matched controls participated. Sonography was performed at the proximal, mid-, and distal portions of each patellar tendon. One-way ANOVAs were conducted to compare thickness and collagen fiber organization and a chi-square analysis was used to compare the presence of neovascularity between the three tendon groups. Compared to healthy controls, both tendons in the amputees exhibited increased thickness at the mid- and distal portions and a higher degree of collagen fiber disorganization. Furthermore, neovascularity was more common in the tendon of the residual limb. Our results suggest that the use of a prosthesis with a PTB feature contributes to morphological changes in bilateral patellar tendons.

Elbow Common Flexor Tendon Repair Technique

Medial epicondylitis, also known as “golfer's elbow,” is a common orthopaedic condition that typically results from overuse of the flexor pronator mass. Repetitive eccentric loading of the muscles responsible for wrist flexion and forearm pronation leads to microtrauma and subsequent degeneration of the flexor pronator tendon. Patients with medial epicondylitis typically present in the fourth to sixth decade of life and have an insidious onset of medial elbow pain. Occasionally, medial epicondylitis may result from an acute traumatic event, such as an acute avulsion of the common flexor tendon. Patients should be examined for concomitant elbow pathologies, including ulnar neuritis and ulnar collateral ligament injury. T2-weighted magnetic resonance imaging can show increased signal intensity in the common flexor tendon or a complete rupture. Nonsurgical management is the mainstay of treatment; however, surgical treatment may be indicated in elite athletes and patients with persistent symptoms after conservative treatment. This technique article with accompanying video describes open debridement and repair of the flexor pronator tendon, with an emphasis on restoration of the anatomic footprint and compression across the repair site to promote biological healing.

T2* mapping and subregion analysis of the tibialis posterior tendon using 3 Tesla magnetic resonance imaging.

Early detection of tibialis posterior tendon changes and appropriate intervention is necessary to prevent disease progression to flat-foot deformity and foot/ankle dysfunction, and the need for operative treatment. Currently, differentiating between early-stage tibialis posterior tendon deficiency patients who will benefit from conservative vs more aggressive treatment is challenging. The objective of this work was to establish a quantitative MRI T2* mapping method and subregion baseline values in the tibialis posterior tendon in asymptomatic ankles for future clinical application in detecting tendon degeneration. 26 asymptomatic volunteers underwent T2* mapping. The tendon was divided axially into seven subregions. Summary statistics for T2* within each subregion were calculated and compared using Tukey post-hoc pairwise comparisons. Results are reported for 24 subjects. The mean tibialis posterior tendon T2* was 7 ± 1 ms. Subregion values ranged from 6 ± 1 to 9 ± 2 ms with significant between-region differences in T2*. Inter- and intrarater absolute agreement intraclass correlation coefficient (ICC) values were all "excellent" (0.75 < ICC=1.00) except for regions 5 through 7, which had "fair to good" interrater and/or and intrarater ICC values (0.4 < ICC=0.75). A tibialis posterior tendon T2* mapping protocol, subregion division method, and baseline T2* values for clinically relevant regions were established. Significant differences in T2* were observed along the tendon length. This work demonstrates that regional variation exists and should be considered for future T2*-based research on posterior tibias tendon degeneration and when using T2* mapping to evaluate for potential tibialis posterior tendon degeneration.