Periprosthetic joint infection after total hip arthroplasty induces histological degeneration of the gluteus medius tendon.

Aims: A revision for periprosthetic joint infection (PJI) in total hip arthroplasty (THA) has a major effect on the patient's quality of life, including walking capacity. The objective of this case control study was to investigate the histological and ultrastructural changes to the gluteus medius tendon (GMED) in patients revised due to a PJI, and to compare it with revision THAs without infection performed using the same lateral approach.

Methods: A group of eight patients revised due to a PJI with a previous lateral approach was compared with a group of 21 revised THAs without infection, performed using the same approach.

Histological and ultrastructural degenerative findings in the gluteus medius tendon after hip arthroplasty.

Background: Despite gluteus medius (GMED) tendinosis being relatively common, its presence in association with hip osteoarthritis (OA) or total hip arthroplasty (THA) is not well studied. It was hypothesized that more tendon degeneration would be found in patients with OA of the hip and in those that had undergone THA than that in a control group.

Methods: One hundred patients were included between 2016 and 2019 and were included into 4 groups; the patients were undergoing revision surgery in two groups and primary THA in the other two groups; 22 patients had previously undergone primary THA through a direct lateral approach (involving sectioning of the GMED tendon), 24 patients had previously undergone primary THA through a posterior approach (leaving the GMED tendon intact), 29 patients had primary hip OA, and 25 patients who suffered a femoral neck fracture served as controls.

[Missed diagnosis of Achilles tendon ruptures most common in elderly patients].

We audited forty-six patients with a rupture of the Achilles tendon notified to the Swedish regulatory authority (the Health and Social Care Inspectorate) due to suspicion of malpractice. The patients' history and clinical presentation differed from those with a more classical acute rupture. The diagnostic errors were often found in patients older than 60 years, they were just as common in women as in men and the symptoms often had a subacute start.

More histologic and ultrastructural degenerative signs in the subscapularis tendon and the joint capsule in male patients with shoulder impingement.

Purpose: The purpose of the present study was to analyze biopsy samples from the subscapularis tendon and from the joint capsule from male patients with shoulder impingement syndrome (SAIS) and compare them with samples from male patients with post-traumatic recurrent shoulder instability. The hypothesis of the study was that patients with SAIS would have more histologic and ultrastructural degenerative changes in their subscapularis tendon and joint capsule than patients with post-traumatic recurrent shoulder instability.

Methods: Male patients scheduled for surgery, with either subacromial decompression or Bankart reconstruction, were included.

Altered patterns of displacement within the Achilles tendon following surgical repair.

Purpose: Ultrasound speckle tracking was used to compare tendon deformation patterns between uninjured and surgically repaired Achilles tendons at 14-27-month follow-up. The hypothesis was that the non-homogenous displacement pattern previously described in uninjured tendons, where displacement within deep layers of the tendons exceeds that of superficial layers, is altered following tendon rupture and subsequent surgical repair.

Methods: In the first part of this study, an in-house-developed block-matching speckle tracking algorithm was evaluated for assessment of displacement on porcine flexor digitorum tendons.

Histological Evaluation of Regenerated Semitendinosus Tendon a Minimum of 6 Years After Harvest for Anterior Cruciate Ligament Reconstruction.

Background: Semitendinosus (ST) and/or gracilis (G) autografts are the most used grafts for anterior cruciate ligament (ACL) surgery. The tendons have been shown to be able to regenerate but with focal areas of scar tissue in the short term. There are no long-term histological studies of the regenerated tendons.

Dynamic contrast enhanced magnetic resonance imaging in chronic Achilles tendinosis.

Background: Chronic Achilles tendinosis is a common problem. When evaluating and comparing different therapies there is a need for reliable imaging methods. Our aim was to evaluate if chronic Achilles tendinosis affects the dynamic contrast-enhancement in the tendon and its surroundings and if short-term eccentric calf-muscle training normalizes the dynamic contrast-enhancement.

The reharvested patellar tendon has the potential for ligamentization when used for anterior cruciate ligament revision surgery.

Purpose: The aim of the present study was to make an in-depth clinical, radiographical, and histological evaluation of patients who underwent anterior cruciate ligament (ACL) revision surgery with reharvested central third patellar tendon autograft.

Methods: Four patients (two women and two men) underwent ACL revision surgery with reharvested patellar tendon autograft 71 (66-120) months after the primary reconstruction. The patients were followed prospectively and underwent a clinical examination and magnetic resonance imaging (MRI) at two and 10 years.

Non-uniform displacement within the Achilles tendon during passive ankle joint motion.

Purpose: An initial step in the understanding of Achilles tendon dynamics is to investigate the effects of passive motion, thereby minimising muscle activation and reducing internal joint forces. Internal tendon dynamics during passive ankle joint motion have direct implications for clinical rehabilitation protocols after Achilles tendon surgery. The aim of this study was to test the hypothesis that tendon tissue displacement is different in different layers of the Achilles tendon during controlled passive ankle joint movements.

The long-term clinical and MRI results following eccentric calf muscle training in chronic Achilles tendinosis.

Purpose: To evaluate the long-term results following eccentric calf-muscle training in patients with chronic Achilles tendinopathy.

Materials And Methods: A total of 24 patients with chronic Achilles tendinopathy were included in a study evaluating MRI findings and clinical symptoms before and after 3 months of daily eccentric calf-muscle strength training. Median duration of symptoms was 18 months (range 6-120).

Force in the achilles tendon during walking with ankle foot orthosis.

Background: Ankle foot orthoses are used for postoperative treatment of Achilles tendon ruptures and decrease calf muscle electromyography activity during walking.

Hypothesis: Achilles tendon load decreases with increased restriction of dorsiflexion and is associated with decreased triceps surae activity.

Study Design: Controlled laboratory study.

A histological and ultrastructural evaluation of the patellar tendon 10 years after reharvesting its central third.

Purpose: This study was undertaken to evaluate the histologic and ultrastructural characteristics of the patellar tendon 10 years after reharvesting its central third.

Hypothesis: In the long term, after its central third is reharvested, the patellar tendon does not regain a normal histological and ultrastructural appearance.

Study Design: Case-control study; Level of evidence, 3.

The temporal responses of protein synthesis, gene expression and cell signalling in human quadriceps muscle and patellar tendon to disuse.

We hypothesized that rates of myofibrillar and patellar tendon collagen synthesis would fall over time during disuse, the changes being accompanied in muscle by decreases in focal adhesion kinase (FAK) phosphorylation and in gene expression for proteolytic enzymes. We studied nine men (22 +/- 4 years, BMI 24 +/- 3 kg m(-2) (means +/- s.d.

Ultrastructural collagen fibril alterations in the patellar tendon 6 years after harvesting its central third.

Background: Clinically, donor site problems are common, even in the long term after anterior cruciate ligament reconstruction using patellar tendon autograft. However, there is a lack of knowledge in terms of the mid- and long-term ultrastructural appearance of the previously harvested tendon in humans.

Hypothesis: The patellar tendon does not regain normal ultrastructure 6 years after harvesting its central third and leaving the defect open.

Magnetic resonance signal, rather than tendon volume, correlates to pain and functional impairment in chronic Achilles tendinopathy.

Purpose: To depict abnormal tendon matrix composition using magnetic resonance imaging (MRI) in chronic Achilles tendinopathy, and correlate intratendinous signal alterations to pain and functional impairment.

Material And Methods: MRI of the Achilles tendon was performed on 25 patients with chronic Achilles tendinopathy (median age 50, range 37-71 years). All patients suffered from pain in the mid-portion of the Achilles tendon.

Increased expression of aggrecan and biglycan mRNA in Achilles tendinopathy.

Objectives: To determine the expression of mRNA encoding the proteoglycans aggrecan, versican, biglycan and decorin in mid-tendon samples of chronic painful Achilles tendinopathy and ruptured Achilles tendons, compared with normal tendons.

Methods: Total RNA isolated from frozen tendon samples (14 normal, 13 painful, 14 ruptured) was assayed by relative quantitative reverse transcription polymerase chain reaction for aggrecan, versican, biglycan and decorin mRNA, normalized using 18S rRNA. Differences between sample groups were tested by univariate analysis of variance with age as co-variate.

Reliability in the assessment of tendon volume and intratendinous signal of the Achilles tendon on MRI: a methodological description.

The purpose is to introduce a method for accurately and objectively evaluating volume and mean intratendinous signal within the Achilles tendon using MRI. We prospectively studied MRI from 33 patients with chronic Achilles tendinosis (20 males and 13 females) with a median age of 52 years (range 29-70). In all patients, both Achilles tendons were investigated with T1-WI as well as PD-WI MRI.

Acute rupture of the Achilles tendon.

Achilles tendon ruptures are common, and their incidence is increasing. The evidence for best management is controversial, and, in selected patients, conservative management and early mobilization achieves excellent results. Surgery is associated with an increased risk of superficial skin breakdown; however, modern techniques of percutaneous repair that are performed under local anesthesia and followed by early functional rehabilitation are becoming increasingly common, and should be considered when managing such patients.

A long-term serial histological evaluation of the patellar tendon in humans after harvesting its central third.

It is previously known that the patellar tendon does not normalise histologically in the short term after harvesting its central third. The aim of the study was to obtain long-term serial biopsies from the central and peripheral parts of the patellar tendon after the harvesting procedure. Our hypothesis was that in the long term after harvesting its central third, the patellar tendon does not regain normal histological appearance.

Immediate Achilles tendon response after strength training evaluated by MRI.

Purpose: To evaluate the tendon response after acute strength training in chronic Achilles tendinosis using magnetic resonance imaging (MRI).

Methods: Twenty-two patients (44 Achilles tendons, 15 males, 8 patients with bilateral symptoms) with a median age of 45 yr (range 28-57 yr) were included in the study. In all patients, both Achilles tendons were examined with MRI before and immediately after a standardized training program.

Tendon injury and repair after core biopsies in chronic Achilles tendinosis evaluated by serial magnetic resonance imaging.

Objective: To evaluate the morphological response and healing process after transverse ultrasound guided core biopsies in chronic Achilles tendinosis using serial magnetic resonance imaging (MRI) over a period of one year.

Methods: The study included 10 patients. Six had five transverse core biopsies and were longitudinally evaluated by MRI before the biopsies and then after one week, three months, seven months, and one year.

Eccentric training of the gastrocnemius-soleus complex in chronic Achilles tendinopathy results in decreased tendon volume and intratendinous signal as evaluated by MRI.

Background: Satisfactory treatment results have been reported after eccentric calf muscle strength training in patients with chronic Achilles tendinopathy.

Hypothesis: Magnetic resonance imaging may be a useful adjunct in the evaluation of the effect of 3 months of eccentric calf muscle strength training.

Study Design: Prospective cohort study.

Versican splice variant messenger RNA expression in normal human Achilles tendon and tendinopathies.

Objectives: Versican is the principal large proteoglycan expressed in mid-tendon, but its role in tendon pathology is unknown. Our objective was to define the expression of versican isoform splice variant messenger ribonucleic acid (mRNA) in normal Achilles tendons, in chronic painful tendinopathy and in ruptured tendons.

Methods: Total RNA isolated from frozen tendon samples (normal n = 14; chronic painful tendinopathy n = 10; ruptured n = 8) was assayed by relative quantitative reverse transcriptase polymerase chain reaction (RT-PCR) for total versican, versican variants V0, V1, V2, V3 and type I collagen alpha1 mRNA, normalized to glyceraldehyde-3-phosphate dehydrogenase (GAPDH).

Achilles tendinopathy: some aspects of basic science and clinical management.

Achilles tendinopathy is prevalent and potentially incapacitating in athletes involved in running sports. It is a degenerative, not an inflammatory, condition. Most patients respond to conservative measures if the condition is recognised early.

Mechanism of accumulation of cholesterol and cholestanol in tendons and the role of sterol 27-hydroxylase (CYP27A1).

Objective: Tendon xanthomas are deposits of lipids and connective tissue commonly found in hypercholesterolemic patients. Macrophages are likely to be responsible for the lipid accumulation. Normolipidemic patients with the rare disease cerebrotendinous xanthomatosis, lacking the enzyme sterol 27-hydroxylase (CYP27A1), develop prominent xanthomas in tendons and brain containing both cholestanol and cholesterol, with a cholestanol:cholesterol ratio higher than that in the circulation.