Tendinopathy Research Articles

The Role of Novel Protease PAMR1 in Tendinopathy

The Role of Novel Protease PAMR1 in Tendinopathy

Tendon Morphology in Stage II Tibialis Posterior Tendon Dysfunction Is Associated with a Clinical Measure of Deep Posterior Compartment Strength

Category: Ankle Introduction/Purpose: Tibialis Posterior Tendon Dysfunction (TPTD) is thought to be a primary cause of acquired flatfoot and a result of tendon degeneration. High-frequency ultrasound has been used to measure the morphological changes associated with tendon degeneration while clinical measures of foot deformity and strength are used to identify and stage the condition. However, limited data on tendon morphology in subjects with TPTD are available to guide clinical decision making. It was hypothesized that within a group of subjects with Stage II TPTD there would be large differences in tendon cross-sectional area and these differences would be associated with clinical measures of strength. Findings from this study could be used to guide clinical examination and refine future classification schemes. Methods: Thirty-four participants (Age x?x; Sex X Female) diagnosed with unilateral stage II TPTD were included. Measures of tendon cross-sectional area were captured at the level of the medial malleolus using a Sonosite M-Turbo ultrasound unit with a 6-MHz to 13-MHz 45-mm linear transducer (Sonosite Inc. Bothell, WA). Measures of tendon cross-sectional area were completed using ImageJ software. Subjects involved and uninvolved sides were compared for both tendon area and deep posterior compartment strength. Strength was measured using a custom strength testing device to measure plantar-flexion and inversion strength of the deep posterior compartment. All subjects completed self-report measures of function (Foot and Ankle Ability Measure (FAAM)) and self-reported pain on a numerical rating scale. Group comparisons were made with a one-way ANONA comparing groups with an alpha level maintained at 0.05. Results: Tibialis Posterior Tendon cross sectional area for the group of 34 subjects averaged 31.9% larger on the involved compared to the uninvolved side consistent with signs of degeneration. However, values ranged from 110% larger on the involved side to 43% smaller on the involved side across the group. Due to the observed variance, the group was divided into an enlarged tendon group (n=16) and an average size group (n=18). The enlarged group had an average tendon cross-sectional area of 62.6%(22.2%) larger on the involved side while the average size group averaged 2.9%(22.2%) (p<0.001). Comparing the deep posterior compartment strength between groups, the enlarged group was 34.6%(32.7%) weaker on the involved side while the average tendon area group was 11.4%(34.4%) weaker on the involved side (p=0.04). Conclusion: Tendon cross sectional area varies widely despite a classification of stage II TPTD and self-report of similar pain and function across patients. Subjects tested who had greater tendon cross-sectional area, indicating more degeneration, also demonstrate greater weakness. No differences in self-reported pain, leg strength, or function were found between groups. Deep posterior compartment weakness and tendon morphology may help to inform classification systems and predict outcomes for subjects with TPTD.

Shear Wave Elastography Findings of Achilles Tendons in Patients on Chronic Hemodialysis and Patients with renal Transplantation

Introduction Achilles tendon which was comprised of tendinous parts of gastrocnemius and soleus muscles is the strongest and the largest tendon in the human body. Chronic renal disease is related to reduced physical activity, exercise capacity. Spontaneous rupture of achilles tendon have been reported in patients with chronic renal disease and degeneratif changes, recurrent microtraumas, hypoxia, chronic acidosis are predisposing factors. The aim of the study is to assess the degeneration of achilles tendon by shear wave elastography to compare the elastographic findings of Achilles tendons in patients on chronic hemodialysis, patients with renal transplantation and healthy adults. Materials and Methods Twenty-five patients who were on chronic hemodialysis at least 5 years, twenty-five renal transplant patients and twenty-five healthy controls were included in this study. The thickness and shear wave velocity (SWV) of the middle thirds of the achilles tendons were measured bilaterally. Results The mean SWV of right achilles was 3,67 cm/sn left achilles was 3,64 cm/sn in hemodialysis group. The mean SWV of right achilles was 4,29 cm/sn left achilles was 4,25 cm/sn in renal transplant group. The mean SWV of right achilles was 6,68 cm/sn left achilles was 6,59 cm/sn in control group. There was a statistically significant difference between the SWVs of hemodialysis group, renal transplant group and control group (p<0,005). Conclusion The achilles tendons in patients with chronic renal failure were softer than in patients with renal transplantation and control group. Chronic tendinopathy cause softening and weakening of the tendon. In the renal transplant group stiffness of the achilles tendon was increased with respect to hemodialysis group but still softer than the control group which could be explained by the positive clinical effect of renal transplantation. In conclusion shear wave elastography is an objective, easy, noninvasive, method that can asssess tendinopathy.

Morphometric Measurements of the Calcaneus in Adults with Stage IIb, Posterior Tibial Tendon Dysfunction

Category: Hindfoot Introduction/Purpose: The pathophysiology of adult-acquired flatfoot deformity (AAFD) is not fully explained by degeneration of the posterior tibial tendon alone. While a shortened or dysplastic lateral column has been implicated in flatfoot deformity in pediatric population, there is no study that has quantified the degree of shortening or dysplasia in adults with a stage IIb flatfoot deformity, or if any exists at all. The purpose of this study was to use reconstructive 3D modeling from computed tomography (CT) scans of the calcaneus in order to perform three-dimensional morphometric measurements of the lateral column in patients with stage IIb posterior tibial tendon dysfunction (PTTD) compared to controls in an effort to better understand the morphology of patients with AAFD. Methods: After IRB approval, an institutional radiology database was queried for patients with PTTD who had CT performed between January 2011 and June 2016. Controls were patients receiving CT scan for an intraarticular distal tibia fracture without preexisting foot or calcaneal pathology. Clinical office notes, physical examination, and weight-bearing radiographs were used to identify patients that met clinical criteria for stage IIb PTTD. A 1:1 match was performed using age, laterality, gender, and BMI. Morphometric measurements of the calcanei were performed involving the length of the calcaneal axis (LCA), height of the anterior process (HAP), and length of the anterior process (LAP) (Figure 1). Linear mixed-effects models were used to assess the differences between control and PTTD patients with respect to LAP, HAP, and LCA measurements, with also considering measurements from 3 independent observers. We considered a difference of ± 4 mm as our threshold of clinical significance. Results: Of the 3586 CT within our institutional database, a total of 14 patients were available for reconstruction and analysis. There were no statistical differences detected between patient characteristics or demographics between these groups. On average, the long axis of the calcaneus (LCA) was 3.1 mm shorter (95% confidence interval: 0.43-5.76 mm) in patients with stage IIb PTTD compared to controls (p&lt;0.05). Additionally, the distance from the articular margin of the posterior facet to the anterior process (LAP) was shorter in PTTD patients compared to controls 3.35 mm (p&lt;0.001; 95% confidence interval: 1.82- 4.88). Comparison of observers demonstrated high agreement between LCA and LAP measurements, as illustrated by satisfactory concordance correlation coefficients. Conclusion: Our results support the hypothesis that the calcaneus of adult patients with stage IIb AAFD is, indeed, dysplastic when compared to healthy controls, which further supports the utility of LCL. Analysis of these results, taken together with previous literature, may suggest the use of a smaller graft between 4-6 mm as ideal when performing this procedure.

Perioperative platelet rich plasma (PRP) in total hip arthroplasty through the Hardinge approach: protocol to study the effectiveness for gluteus medius healing

BackgroundPlatelet-rich plasma (PRP) has been used to support tendon regeneration mainly in sports medicine. PRP is a concentrate of platelet-rich plasma proteins derived from whole blood by centrifugation to remove erythrocytes and leukocytes. PRP has high amounts of platelets which may promote healing tendons affected by degenerative conditions. These platelets contain growth factors and are known to facilitate the regeneration of injured tendon structures. Total hip arthroplasty (THA) through the Hardinge approach may leave the patient with impaired gait and poor regeneration of the gluteus medius tendon if the tendon is not reattached properly after closure of the surgical wound.MethodsThe study will be a multicenter, double-blinded and randomized study enrolling 90 patients based on power calculations. The efficacy of perioperative PRP treatment will be assessed by subjective and objective outcome variables. The participants will be randomized (sealed envelope) into either a placebo (saline) or a PRP group (1:1). For subjective outcomes, the Oxford Hip Score (OHS) will be collected before surgery and 3 and 12 months after surgery. The objective measures are findings at magnetic resonance imaging and plain radiographs and recorded values of measured strength.DiscussionWe present the perioperative use and the ways to measure the clinical efficacy of PRP. As PRP may have benefits regarding degenerative tendon regeneration, studies on the use of PRP in hip arthroplasty are warranted to facilitate postoperative recovery.Trial registrationThis study has been approved by the ethics committee of the Hospital District of Southwest Finland and approved by the local institutional research board. The study has been registered in ClinicalTrials.gov (NCT02607462).

A Protocol to Acquire the Degenerative Tenocyte from Humans.

Tendinopathy, a painful condition that develops in response to tendon degeneration, is on the rise in the developed world due to increasing physical activity and longer life expectancy. Despite its increasing prevalence, the underlying pathogenesis still remains unclear, and treatment is generally symptomatic. Recently, numerous therapeutic options, including growth factors, stem cells, and gene therapy, were investigated in hopes of enhancing the healing potency of the degenerative tendon. However, the majority of these research studies were conducted only on animal models or healthy human tenocytes. Despite some studies using pathological tenocytes, to the best of our knowledge there is currently no protocol describing how to obtain human degenerative tenocytes. The aim of this study is to describe a standard protocol for acquiring human degenerative tenocytes. Initially, the tendon tissue was harvested from a patient with lateral epicondylitis during surgery. Then biopsy samples were taken from the extensor carpi radialis brevis tendon corresponding to structural changes observed at the time of surgery. All of the harvested tendons appeared to be dull, gray, friable, and edematous, which made them visually distinct from the healthy ones. Tenocytes were cultured and used for experiments. Meanwhile, half of the harvested tissues were analyzed histologically, and it was shown that they shared the same key features of tendinopathy (angiofibroblastic dysplasia or hyperplasia). A secondary analysis by immunocytochemistry confirmed that the cultured cells were tenocytes with the majority of the cells having positive stains for mohawk and tenomodulin proteins. The qualities of the degenerative nature of tenocytes were then determined by comparing the cells with the healthy control using a proliferation assay or qRT-PCR. The degenerative tenocyte displayed a higher proliferation rate and similar gene expression patterns of tendinopathy that matched previous reports. Overall, this new protocol might provide a useful tool for future studies of tendinopathy.

Soft tissue microcirculation around the healthy Achilles tendon: a cross-sectional study focusing on the Achilles tendon and dorsal surgical approaches to the hindfoot

BackgroundDorsal approaches to the hindfoot are frequently used. Furthermore, the vascular supply is discussed as a possible cause for ruptures and degeneration of the Achilles tendon. The aim of this study was to evaluate the microperfusion of three possible posterior approaches to the hindfoot and different areas of the Achilles tendon.MethodsIn 111 subjects, a laser Doppler/white light spectroscopy was used to measure microperfusion in terms of blood flow (Flow) and capillary venous oxygen saturation (SO2) in the hindfoot and Achilles tendon. Measurements were performed at two measurement points (MP, proximal and distal) of three dorsal approaches (medial, lateral and central) and inside the Achilles tendon.ResultsMicroperfusion differed partially between the surgical approaches. The medial and the lateral approaches were significantly superior to the central approach with regard to Flow in both MP (p < 0.001), while SO2 was significantly higher at the proximal measurement point (MP 1; p < 0.001). In this area, the lateral approach was significantly superior to the medial approach regarding Flow (MP 1; p = 0.012).The Achilles tendon exhibited a significantly reduced microperfusion 5 cm proximal to the calcaneal tubercle (SO2 p = 0.001; Flow p = 0.048). Demographic factors, such as body mass index and age, had different effects. Microcirculation was partially superior in men and negatively affected by smoking.ConclusionsSoft tissue microcirculation on the lateral and medial side of the healthy Achilles tendon was better than centrally on the tendon. Proximally, the lateral approach was better than the medial approach. These circumstances could provide advantages regarding the surgical approach. The Achilles tendon exhibited significantly reduced microperfusion at the typical side of degeneration and rupture. This circumstance could be a possible cause of degenerative processes.

Release of pro-inflammatory cytokines from muscle and bone causes tenocyte death in a novel rotator cuff in vitro explant culture model

ABSTRACTPurpose: Tendinopathy is a significant clinical problem thought to be associated with altered mechanical loading. Explant culture models allow researchers to alter mechanical loading in a controlled in vitro environment while maintaining tenocytes in their native matrix. However, current models do not accurately represent commonly injured tendons, ignoring contributions of associated musculature and bone, as well as regional collagen structure. This study details the characterization of amouse rotator cuff explant culture model, including bone, tendon, and muscle (BTM). Materials and Methods: Following harvest, BTM explants were maintained in stress-deprived culture for one week and tendon was then assessed for changes in cell viability, metabolism, matrix structure and content. Results: Matrix turnover occurred throughout culture as manifested in both gene expression and biosynthesis, but this did not translate to net changes in total collagen or sulfated glycosaminoglycan content. Furthermore, tendon structure was not significantly altered throughout culture. However, we found significant cell death in BTM tendons after 3 days in culture, which we hypothesize is cytokine-induced. Using a targeted multiplex assay, we found high levels of pro-inflammatory cytokines released to the culture medium from muscle and bone, levels that did cause cell deathin tendon-alone controls. Conclusions: Overall, this model presents an innovative approach to understandingrotator cuff injury and tenocyte mechanobiology in a clinically-relevant tendon structure. Our model can be a powerful tool to investigate how mechanical and biological stimuli can alter normal tendon health and lead to tendon degeneration, and may provide a testbed for therapeutics for tendon repair.

The Effect of PRGF on Healing of Clamp-Induced Tendinopathy in Animals

The Effect of PRGF on Healing of Clamp-Induced Tendinopathy in Animals

Tendon Pathology: Have we missed the first step in the development of pathology?

Tendon Pathology: Have we missed the first step in the development of pathology?

Development and biological validation of a cyclic stretch culture system for the ex vivo engineering of tendons.

An innovative approach to the treatment of tendon injury or degeneration is given by engineered grafts, made available through the development of bioreactors that generate tendon tissue in vitro, by replicating in vivo conditions. This work aims at the design of a bioreactor capable of applying a stimulation of cyclic strain on cell constructs to promote the production of bioartificial tissue with mechanical and biochemical properties resembling those of the native tissue. The system was actuated by an electromagnet and design specifications were imposed as follows. The stimulation protocol provides to scaffolds a 3% preload, a 10% deformation, and a stimulation frequency rate set at 0.5, 1, and 2 Hz, which alternates stimulation/resting phases. Porcine tenocytes were seeded on collagen scaffolds and cultured in static or dynamic conditions for 7 and 14 days. The culture medium temperature did not exceed 37°C during prolonged culture experiments. The applied force oscillates between 1.5 and 4.5 N. The cyclic stimulation of the engineered constructs let both the cells and the scaffold fibers align along the strain direction in response to the mechanical stimulus. We designed a pulsatile strain bioreactor for tendon tissue engineering. The in vitro characterization shows a preferential cell alignment at short time points. Prolonged culture time, however, seems to influence negatively on the survival of the cells indicating the need of further optimization concerning the culture conditions and the mechanical stimulation.

Do Biomarkers Play A Role On Tendinopathy?

Do Biomarkers Play A Role On Tendinopathy?

A review of sports-related injuries: Head to toe spectrum

All sports come with a risk of injury, and in general, the more contact involved in the sports, the higher the risk of a more significant or traumatic injury. The most frequent types of sports injuries are sprains (ligament injuries), strains (muscle injuries), and stress fractures (bone injuries). In sports medicine, a catastrophic injury is defined as severe trauma to the human head, spine, or brain. Concussions in sports became a major issue in the 2000s as evidence connected repeated concussions and subconcussive hits with chronic traumatic encephalopathy and increased suicide risk. Overuse and repetitive stress injury problems associated with sports include jumper's knee, tennis elbow, and tendinosis. In this review article, we have made an attempt to describe the head to toe spectrum of sports-related injuries including traumatic injuries of the head and face, extremity injuries, soft-tissue injuries, and contact sports-related injuries.

Tendonitis on the Fingers in Behçet's Disease.

Tendonitis on the Fingers in Behçet's Disease.

Can Genipin-coated Sutures Deliver a Collagen Crosslinking Agent to Improve Suture Pullout in Degenerated Tendon? An Ex Vivo Animal Study.

BackgroundThe suture-tendon interface is often the weakest link in tendon-to-tendon or tendon-to-bone repair. Genipin is an exogenous collagen crosslink agent derived from the gardenia fruit that can enhance suture force to failure of the tendon-suture interface. Viable methods for intraoperative clinical delivery of genipin could be of clinical utility, but to our knowledge have not yet been extensively studied.Questions/purposesThe purposes of this study were (1) to evaluate whether sutures precoated with genipin can augment the suture-tendon interface to improve force to failure, stiffness, and work to failure in healthy and degenerated tendons; and (2) to determine the effect of genipin on the extent and distribution of crosslinking.MethodsSingle-stitch suture pullout tests were performed ex vivo on 25 bovine superficial digital flexor tendons. To assess effects on native tissue, one group of 12 tendons was cut in proximal and distal halves and randomized to treatment (n = 12) and control groups (n = 12) in a matched-pair design. One simple stitch with a loop with either a normal suture or genipin-coated suture was applied to tendons in both groups. To simulate a degenerative tendon condition, a second group of 13 tendons was cut in proximal and distal halves, injected with 0.2 mL of collagenase D (8 mg/mL) and incubated for 24 hours before suturing with either a genipin-coated suture (n = 13) or their matched controls (n = 13). Sutures from all groups then were loaded to failure on a universal materials testing machine 24 hours after suturing. Suture pullout force, stiffness, and work to failure were calculated from force-displacement data and compared between the groups. Additionally, fluorescence was measured to determine the degree of crosslinking quantitatively and a qualitative analysis of the distribution pattern was performed by microscopy.ResultsIn healthy tendon pairs, the median maximum pullout force was greater with genipin-coated sutures than with control sutures (median, 42 N [range, 24–73 N] versus 29 N [range, 13–48 N]; difference of medians, 13 N; p = 0.003) with corresponding increases in the required work to failure (median, 275 mJ [range, 48–369 mJ] versus 148 mJ [range, 83–369 mJ]; difference of medians, 127 mJ; p = 0.025) but not stiffness (median, 4.1 N/mm [range, 2.3–8.1 N/mm] versus 3.3 N/mm [range, 1.1–9.6 N/mm]; difference of medians, 0.8 N/mm; p = 0.052). In degenerated tendons, median maximum pullout force was greater with genipin-coated sutures than with control sutures (median, 16 N [range, 9-36 N] versus 13 N [range, 5-28 N]; difference of medians, 3 N; p = 0.034) with no differences in work to failure (median, 75 mJ [range, 11–249 mJ] versus 53 mJ [range, 14–143 mJ]; difference of medians, 22 mJ; p = 0.636) or stiffness (median, 1.9 N/mm [range, 0.7–13.4 N/mm] versus 1.6 N/mm [range, 0.5–5.6 N/mm]; difference of medians, 0.3 N/mm; p = 0.285). Fluorescence was higher in tendons treated with genipin-coated sutures compared with the control group, whereas higher fluorescence was observed in the treated healthy compared with the degenerated tendons (difference of means -3.16; standard error 1.08; 95% confidence interval [CI], 0.97–5.34; p = 0.006/healthy genipin: mean 13.04; standard error 0.78; 95% CI, 11.47-14.62; p < 0.001/degenerated genipin: mean 9.88; SD 0.75; 95% CI, 8.34-11.40; p < 0.001).ConclusionsGenipin-coated sutures improved force to failure of a simple stitch at the tendon-suture interface in healthy and degenerated tendons in an ex vivo animal model. Fluorescence was higher in tendons treated with genipin-coated sutures compared with the control group.Clinical RelevanceA genipin-coated suture represents a potential delivery vehicle for exogenous crosslink agents to augment suture retention properties. In vivo animal studies are the next logical step to assess safety and efficacy of the approach.

Fluoroquinolone Use Is Associated with Excess Risk for Aortic Aneurysm or Dissection

Fluoroquinolones are associated with tendinopathy and tendon rupture (NEJM JW Gen Med Jan 1 2013 and Am J Med 2012; 125:1228.e23). The presumed

Matrix metalloproteinase-1 (MMP-1) and (MMP-8) gene polymorphisms promote increase and remodeling of the collagen III and V in posterior tibial tendinopathy.

Posterior tibial tendinopathy (PTT) can lead to acquired flatfoot in adults. Many patients develop PTT without any identifiable risk factors. Molecular changes in extracellular matrix (ECM) and matrix metalloproteinase (MMP) polymorphism may influence the risk of developing PTT. We aim to investigate the association between matrix metalloproteinase-1 (MMP-1) and (MMP-8) gene polymorphisms with changes in collagen I, III and V in PTT. A case-control study with 22 patients and 5 controls was performed. The MMP-1 (2G/2G) and MMP-8 (T/T) genotypes were determined by PCR-restriction fragment length polymorphism. Tendon specimens were evaluated by a histologic semiquantitative score, immunofluorescence and histomorphometry for collagen I, III and V. Tendon specimens from PTT demonstrated marked distortion of the architecture with necrosis, large basophilic areas with disruption of the normal linear orientation of collagen bundles, infiltration of inflammatory cells, dystrophic calcification and ossification. Under immunofluorescence, PTT tendon specimens showed weak green fluorescence and diffuse distribution of collagen I fibers, but strong fluorescence of collagen III and V. The collagen I fibers were significantly decreased whereas an increase of collagen III and V were found in PTT compared to control groups. In addition, PTT group presented a significant association with MMP-1 and MMP-8 gene polymorphisms. Patients with PTT matrix metalloproteinase-1 (MMP-1) and (MMP-8) gene polymorphisms presented an increase of the collagen III and V ratio, suggesting that the higher proportion in degenerated tendons could contribute to a decrease in the mechanical resistance of the tissue. Still, functional and association studies are needed to elucidate evident roles of MMPs in PTT.

The Role of the Paratenon in Achilles Tendon Healing: A Study in Rats

Background: The role of the paratenon in tendon healing is unknown. The present study compares healing in the presence or absence of the paratenon in an Achilles tendon defect model in rats. Hypothesis: Resection of the paratenon impairs tendon healing. Study Design: Controlled laboratory study. Methods: Sixty skeletally mature Sprague Dawley rats were randomly assigned to either a resected paratenon (RP) group or an intact paratenon (IP) group. In all animals, a 4-mm portion of the Achilles tendon was resected in the midsubstance. In the RP group, the paratenon was resected completely. In the IP group, the paratenon was opened longitudinally and closed again after the tendon defect had been created. One, 2, and 4 weeks after surgery, 7 animals per group were tested biomechanically and 3 animals per group examined histologically. Results: The recovery of mechanical strength was much more rapid in IP tendons. Tear resistance was significantly increased for IP tendons (41.3 ± 8.8 N and 47.3 ± 14.1 N, respectively) compared with RP tendons (19.3 ± 9.1 N and 33.2 ± 6.4 N, respectively) after 1 and 2 weeks. The cross-sectional area was larger in the IP group after 1 and 2 weeks (8.2 ± 2.3 mm2 and 11.3 ± 3.1 mm2 vs 5.0 ± 2.4 mm2 and 5.9 ± 2.0 mm2, respectively) compared with the RP group. Tendon stiffness was greater in the IP group after 1 week (10.4 ± 1.9 N/mm vs 4.5 ± 1.6 N/mm, respectively) compared with the RP group. In comparison, normal contralateral tendons had a maximal tear resistance of 56.6 ± 7.2 N, a cross-sectional area of 3.6 ± 0.7 mm2, and stiffness of 17.3 ± 3.8 N/mm. Hematoxylin and eosin staining revealed slightly delayed healing of RP tendons. Early collagen formation was seen in the IP group already after 1 week, whereas in the RP group, this only occurred after 2 weeks. After 4 weeks, the IP tendons showed more collagen crimp formation than the RP tendons. Conclusion: An intact paratenon promotes healing of the Achilles tendon. Clinical Relevance: Although incision or resection of the paratenon has been advocated when repairing injured or degenerative tendons, our data suggest that the integrity of the paratenon should be preserved.

Comparative Analysis of Platelet-rich Plasma Effect on Tenocytes from Normal Human Rotator Cuff Tendon and Human Rotator Cuff Tendon with Degenerative Tears.

BackgroundPlatelet-rich plasma (PRP) stimulates cell proliferation and enhances matrix gene expression and synthesis. However, there have been no comparative study of the PRP effect on the normal and degenerative tenocytes. The purpose of this study was to compare the effect of PRP on tenocytes from normal and degenerative tendon.MethodsTendon tissues were obtained from patients undergoing arthroscopic repair (n=9) and from healthy donors (n=3). Tenocytes were cultured with 10% (vol/vol) platelet-poor plasma, PRP activated with calcium, and PRP activated with calcium and thrombin. The total cell number was assessed at days 7 and 14. The expressions of type I and III collagen, decorin, tenascin-C, and scleraxis were evaluated by quantitative real-time reverse transcriptase polymerase chain reaction. The total collagen and glycosaminoglycan (GAG) synthesis was evaluated at days 7 and 14.ResultsNo differences were observed between the groups at day 7, but cell proliferation was remarkably increased in tenocytes from the degenerative tendon at day 14. In both tenocyte groups, the gene expressions of type I and III collagen were up-regulated. GAG synthesis was greater in the normal tendon, whereas the expressions of decorin and tenascin-C were increased in tenocytes from the degenerative tendon. Tenocytes from the degenerative tendon had higher fold-change of GAG synthesis and a lower collagen III/I ratio than normal tenocytes.ConclusionsPRP promoted the cell proliferation and enhanced the synthesis of tendon matrix in both groups. PRP has a greater positive effect on cell proliferation, matrix gene expression and synthesis in tenocytes from degenerative tendon.

Superior Capsule Reconstruction for Reinforcement Before Arthroscopic Rotator Cuff Repair Improves Cuff Integrity

Objectives:We developed the superior capsule reconstruction (SCR) technique for surgical treatment of irreparable rotator cuff tears. In these patients, SCR restores shoulder stability and muscle balance, consequently improving shoulder function and relieving pain. In this study, we evaluated whether SCR for reinforcement before arthroscopic rotator cuff repair (ARCR) improves cuff integrity, especially in the case of severely degenerated supraspinatus tendon.Methods:A series of 32 consecutive patients (mean age, 69.0 years) with severely degenerated but reparable rotator cuff tears (medium size: 1-3 cm, and large size: 3-5 cm) underwent SCR using fascia lata autografts for reinforcement before ARCR. To determine the indications for SCR for reinforcement, the severity of degeneration in the torn supraspinatus tendon was assessed. We evaluated fatty degeneration in the muscle by using the Goutallier grade; we also scored retraction of the torn tendon (grade 0: no retraction; grade 1: torn edge on the greater tuberosity; grade 2: torn edge on the lateral half of the humeral head; grade 3: torn edge on the medial half of the humeral head; grade 4: torn edge on the glenoid) and tendon quality (grade 0: normal; grade 1: slightly thin, or slight fatty degeneration in the tendon part; grade 2: severely thin, or severe fatty degeneration in the tendon part; grade 3: severely thin, and severe fatty degeneration in the tendon part; grade 4: no tendon). In patients classified with grade 3 or 4 in at least two of these three categories, arthroscopic SCR was performed for reinforcement, after which the torn tendon was repaired over the fascia lata graft. To assess the benefit of SCR for reinforcement, the results from these 32 patients were compared with those after ARCR alone in 91 consecutive patients with medium (1-3 cm) to large (3-5 cm) rotator cuff tears (mean age, 66.7 years). Torn tendons were repaired by using double-row suture-bridges with and without SCR for reinforcement. By using t- and chi-square tests, we compared the American Shoulder and Elbow Surgeons (ASES) score, active shoulder range of motion (ROM), and cuff integrity (Sugaya MRI classification) between ARCR with and without SCR as well as between before surgery and at final follow-up (mean, 19 months; 12 to 40 months). A significant difference was defined as P < 0.05.Results:All 32 patients who underwent SCR before ARCR had no postoperative re-tear and demonstrated type I cuff integrity (sufficient thickness with homogeneously low intensity), whereas those treated with ARCR without SCR had a 5.5% incidence (5/91 all patients) of postoperative re-tear, and 22.1% (19/86 healed patients) had type II (partial high-intensity area) or III (insufficient thickness) cuff integrity. ASES score, active elevation, active external rotation, and active internal rotation increased significantly after ARCR both with and without SCR (P < 0.001) (Table). Postoperative ASES score and active ROM did not differ significantly between ARCR with and without SCR, but the Goutallier grade of the supraspinatus was significantly higher for ARCR with SCR (mean, 2.8) than for ARCR alone (mean, 2.1) (P < 0.0001).Conclusion:SCR for reinforcement prevented postoperative re-tear after ARCR and improved the quality of the repaired tendon on MRI. Furthermore, postoperative functional outcomes were similar in patients who underwent ARCR alone and those who also underwent SCR, even though degeneration of the torn tendons was greater in the latter group.TableASES score (points)ASES score (points)Active elevation (degrees)Active elevation (degrees)External rotation (degrees)External rotation (degrees)Internal rotationInternal rotationBeforeAfterBeforeAfterBeforeAfterBeforeAfterARCR with SCR (n=32)45.188.21331613849L4L1ARCR alone (n=91)34.490.61331695258L2T11