Paul Ackermann

Paul Ackermann
Karolinska Institutet | KI · Department of Molecular Medicine and Surgery

MD, PhD
Looking for collaborators with the STOP Leg Clots (SLC) Trial, both in Sweden and Internationally. https://ki.se/en/mmk/

About

158
Publications
31,700
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Introduction
Currently we are focusing our efforts on a multicenter study with the aim to reduce the number of adverse events, i.e. venous thromboembolism (VTE) and failed healing in association with lower limb immobilization. We aim in leg immobilized patients to demonstrate that adjuvant intermittent pneumatic compression (IPC) therapy, which targets impaired vascular flow, compared to treatment-as-usual with plaster cast, reduces VTE-incidence and improves healing. My mission in research is to understand and exploit neuro-vascular pathways in the musculo-skeletal system for restoring joint function, alleviating pain and minimizing complications.
Additional affiliations
August 2012 - present
Karolinska University Hospital
Position
  • Consultant
January 2009 - present
Karolinska Institutet
Position
  • Professor (Associate)
January 1999 - present
Karolinska Universitetssjukhuset

Publications

Publications (158)
Article
Full-text available
Neuromuscular Electrical Stimulation (NMES) uses electrical impulses to induce muscle contractions, providing benefits in rehabilitation, muscle activation, and as an adjunct to exercise, particularly for individuals experiencing immobilization or physical disability. NMES technology has significantly progressed, with advancements in device develop...
Article
Full-text available
The effectiveness of neuromuscular electrical stimulation (NMES) depends on electrode placement, with placement over the motor points (MPs) being the most effective. This study aimed to determine the MP-distribution and establish a heatmap indicating the probability of finding a MP in different areas of the hamstring (H) muscles. Additionally, inte...
Article
Muscle disuse has rapid and debilitating effects on muscle mass and overall health, making it an important issue from both scientific and clinical perspectives. However, the myocellular adaptations to muscle disuse are not yet fully understood, particularly those related to the myonuclear permanence hypothesis. Therefore, in this study, we assessed...
Article
Full-text available
Introduction Given the lack of consensus on optimal treatment strategies for acute Achilles tendon rupture (ATR), understanding temporal trends, treatment choice and demographic characteristics is important. Previous research suggests increasing incidence with declining surgical treatment. Current trends in Sweden are not known. Hypothesis/purpose...
Article
Full-text available
Background. The effect of transcutaneous electrical nerve stimulation (TENS) on pain and impression of change was assessed during a 2.5-hour intervention on the first postoperative days following hip surgery in a randomized, single-blinded, placebo-controlled trial involving 30 patients. Methods. Mixed-frequency TENS (2 Hz/80 Hz) was administered u...
Article
Purpose The aim of the study was to examine the impact of a deep venous thrombosis (DVT) on patient outcomes 3 years after Achilles tendon rupture (ATR) repair and if there were continued improvements between 1 and 3 years after surgery. A secondary aim was to determine risk factors associated with impaired patient outcomes in the long term. Metho...
Article
Full-text available
Aim The influence on acute skeletal muscle transcriptomics of neuromuscular electrical stimulation (NMES), as compared to established exercises, is poorly understood. We aimed to investigate the effects on global mRNA‐expression in the quadriceps muscle early after a single NMES‐session, compared to the effects of voluntary knee extension exercise...
Article
Full-text available
Risk for rupture of the Achilles tendon, and other tendons increases with age. Such injuries of tissues that function in high load environments generally are believed to heal with variable outcome. However, in many cases, the healing does not lead to a good outcome and the patient cannot return to the previous level of participation in active livin...
Conference Paper
Full-text available
Introduction Neuromuscular electrical stimulation (NMES) can be used to activate skeletal muscles and prevent atrophy during immobilization. However the underlying acute transcriptomic effects remains to be established. Thus, this study aimed to investigate how a single NMES-session, compared to a voluntary knee extension session (EX), influenced g...
Article
Background Patient outcome after acute Achilles tendon rupture (ATR) varies and is difficult to predict. Whether early variations in healing, visualized with ultrasonography, can predict long-term patient outcome is unclear. Purpose To (1) examine the associations of Achilles tendon cross-sectional area (CSA) and elongation (TE) during healing of...
Article
Full-text available
Introduction Dense connective tissues (DCTs) such as tendon, ligament, and cartilage are important stabilizers and force transmitters in the musculoskeletal system. The healing processes after DCT injuries are highly variable, often leading to degenerative changes and poor clinical outcome. Biomarkers in relation to repair quality for human DCTs, e...
Article
Full-text available
Neuromuscular electrical stimulation (NMES) of the quadriceps (Q) may increase venous blood flow to reduce the risk of venous thromboembolism. This study assessed whether Q-NMES pants could increase peak venous velocity (PVV) in the femoral vein using Doppler ultrasound and minimize discomfort. On 15 healthy subjects, Q-NMES using textile electrode...
Article
Full-text available
The suboptimal or protracted regeneration of injured connective tissues often results in significant dysfunction, pain, and functional disability. Despite the prevalence of the condition, few studies have been conducted which focused on biomarkers or key molecules involved in processes governing healing outcomes. To gain insight into injured connec...
Article
Full-text available
Purpose To compare fixed transverse textile electrodes (TTE) knitted into a sock versus motor point placed standard gel electrodes (MPE) on peak venous velocity (PVV) and discomfort, during calf neuromuscular electrical stimulation (calf-NMES). Methods Ten healthy participants received calf-NMES with increasing intensity until plantar flexion (mea...
Article
Full-text available
Outcomes following human dense connective tissue (DCT) repair are often variable and suboptimal, resulting in compromised function and development of chronic painful degenerative diseases. Moreover, biomarkers and mechanisms that guide good clinical outcomes after DCT injuries are mostly unknown. Here, we characterize the proteomic landscape of DCT...
Article
Full-text available
Purpose Physical inactivity is associated with muscle atrophy and venous thromboembolism, which may be prevented by neuromuscular electrical stimulation (NMES). This study aimed to investigate the effect on discomfort, current amplitude and energy consumption when varying the frequency and phase duration of low-intensity NMES (LI-NMES) via a sock w...
Article
Full-text available
Purpose: To create an anatomical chart that indicates the probability of finding a motor point (MP) in different areas of the quadriceps muscle. Methods: On 31 healthy adults, the individual anatomy of the vastus medialis (VM), rectus femoris (RF) and vastus lateralis (VL) was determined using ultrasound. Thereafter, a 3 Hz neuromuscular electri...
Article
Full-text available
Background Contractions of muscles in the calf induced by neuromuscular electrical stimulation (NMES) may prevent venous thromboembolism, help rehabilitation and optimize strength training, among other uses. However, compliance to NMES-treatment is limited by the use of suboptimal stimulation points which may cause discomfort and less effectivity....
Conference Paper
Full-text available
Introduction In the aftermath of Achilles tendon rupture (ATR) a period of immobilization is always needed. For ATR, the immobilization period is normally 6–8 weeks which can cause significant leg muscle deconditioning and muscle weakness. Descriptive studies of limb deconditioning in the early stages after ATR injury are lacking and could yield ne...
Article
Full-text available
Tendons are dense connective tissues of the musculoskeletal system that link bones with muscles to foster mobility. They have complex structures and exist in varying biomechanical, metabolic and biological environments. In addition, tendon composition and mechanical properties can change over the lifespan as an individual ages. Many tendons functio...
Preprint
Full-text available
Outcomes following human dense connective tissue (DCT) repair are often variable and suboptimal, resulting in compromised function and development of chronic painful degenerative diseases. Moreover, biomarkers and mechanisms that guide good clinical outcomes after DCT injuries are mostly unknown. Here, we characterize the proteomic landscape of DCT...
Preprint
Outcomes following human dense connective tissue (DCT) repair are often variable and suboptimal, resulting in compromised function and development of chronic painful degenerative diseases. Moreover, biomarkers and mechanisms that guide good clinical outcomes after DCT injuries are mostly unknown. Here, we characterize the proteomic landscape of DCT...
Article
Background: Deficits in calf muscle function and heel-rise performance are common after an Achilles tendon rupture (ATR) and are related to tendon elongation and calf muscle atrophy. Whether early functional mobilization (EFM) can improve calf muscle function compared with standard treatment (ST) with 2 weeks of immobilization and unloading in a p...
Article
Full-text available
Objectives Management of chronic tendon pain is difficult and controversial. This is due to poor knowledge of the underlying pathophysiology of chronic tendon pain, priorly known as tendinitis but now termed tendinopathy. The objective of this topical review was to synthesize evolving information of mechanisms in tendon pain, using a comprehensive...
Article
Full-text available
Purpose To investigate whether Neuromuscular Electrical Stimulation (NMES) simultaneously applied on the quadriceps (Q) and gluteal (G) muscles, as compared to single Q-stimulation alters the knee extensor force production and discomfort. Methods A total of 11 healthy participants (6 females), with normal weight and age between 19 and 54 years wer...
Article
Full-text available
Dense connective tissue healing, such as tendon, is protracted leading to highly variable and unsatisfactory patient outcomes. Biomarkers prognostic of long‐term clinical outcomes is, however, unknown. The present study was designed to investigate the proteomic profile of healing, identify potential biomarkers, and assess their association with the...
Article
Full-text available
Update This article was updated on June 17, 2022 because of a previous error. On page 33, in the section entitled “17 - Does administration of tranexamic acid (TXA) to patients undergoing orthopaedic procedures increase the risk of subsequent VTE?”, and in the note on page 161, the name “Armin Arish” now reads “Armin Arshi.” An erratum has been pub...
Article
Full-text available
Background The effect of surgeon experience on patient outcomes after surgical Achilles tendon rupture (ATR) repair has so far been unknown. Purpose To examine whether patient-reported and functional outcomes as well as adverse events after surgical ATR repair differ between orthopaedic specialist surgeons and resident surgeons. Study Design Coho...
Article
Full-text available
Abstract Background Neuromuscular electrical stimulation (NMES) may prevent muscle atrophy, accelerate rehabilitation and enhance blood circulation. Yet, one major drawback is that patient compliance is impeded by the discomfort experienced. It is well-known that the size and placement of electrodes affect the comfort and effect during high-intensi...
Preprint
Full-text available
Background: Contractions of muscles in the calf induced by neuromuscular electrical stimulation (NMES) may prevent venous thromboembolism. However, compliance to NMES-treatment is limited by the use of suboptimal stimulation points which may cause discomfort. Knowledge of where one is most likely to find muscle motor points (MP) could improve NMES...
Preprint
Full-text available
Background: Neuromuscular electrical stimulation (NMES) may improve venous hemodynamics to decrease the risk of venous thromboembolism. However, whether calf-NMES using textile electrodes integrated in socks can improve venous hemodynamics without discomfort is unknown. Aim: The primary aim of this study was to examine whether calf-NMES, using one...
Article
Full-text available
Purpose Healing outcome after Achilles Tendon Rupture (ATR) is variable and unsatisfactory. Many ATR patients still exhibit pain, functional deficits and limitations in walking one-year post-surgery. The present study was designed to investigate the association between the expression of healing biomarkers and patient outcome after ATR. Methods Ten...
Conference Paper
Full-text available
The major reason for preventable hospital death is venous thromboembolism (VTE). Non-pharmacological treatment options include electrical stimulation or compression therapy to improve blood flow in the extremities. Textile electrodes offer potential to replace bulky devices commonly used in this field, thereby improving the user compliance. In this...
Article
Full-text available
This study aimed to compare recovery of gait patterns in patients treated with early functional mobilization (EFM) or standard treatment (ST) after Achilles tendon rupture repair. Second, this study aimed to explore associations between gait patterns and tendon elongation and calf muscle atrophy, respectively. Forty-seven patients (12 females), mea...
Article
Full-text available
Introduction Leg immobilisation in a cast or an orthosis after lower limb injuries is associated with a high risk of complications of venous thromboembolism (VTE) and hampered healing. Current pharmacoprophylaxes of VTE are inefficient and associated with adverse events. Intermittent pneumatic compression (IPC) could represent a novel, efficient an...
Article
Full-text available
Following publication of this article [1], the authors report the following Corrections to the main text: i) The authors noticed that the reported number of patients that were treated surgically were too many (n = 363) and have corrected the numbers (n = 337). Patients from the cohort Nilsson-Helander et al. [2] were incorrectly labeled as surgical...
Article
Background: Early functional mobilization (EFM) may improve patient outcome after Achilles tendon rupture (ATR). However, whether EFM affects patient outcome via changes in tendon elongation, thickening, or calf muscle atrophy is unknown. Purpose: To analyze differences in tendon and muscle morphology recovery over time between groups treated wi...
Article
PurposeTo examine healing adaptations over 17 weeks post Achilles tendon (AT) rupture in the injured region (IR) compared to an uninjured region (UIR) of the AT.Methods Twenty-four rats were subjected to a complete right-sided AT rupture, while the left side served as a control. ATs were harvested at 1, 2, 8 and 17 weeks post-rupture and stained wi...
Article
Full-text available
Background: While numerous clinical studies have compared the surgical and non-surgical treatment of acute Achilles tendon rupture (ATR), there are no studies that have performed a non-inferiority analysis between treatments. Methods: Data from patients who were included in five randomised controlled trials from two different centres in Sweden w...
Article
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PurposeThe primary aim of this study was to assess the relationship between the metabolites lactate and pyruvate in the healing tendon after Achilles tendon rupture (ATR) and patient-reported outcome at 6 and 12 months. A secondary aim was to evaluate which underlying factors regulate lactate and pyruvate concentrations.Methods Lactate and pyruvate...
Article
Full-text available
PurposeAchilles tendon rupture (ATR) is a common injury. The knowledge of seasonal factors´ impact is incomplete, but may provide means for preventive approaches for Achilles tendon related morbidity. The aim of this study was to investigate seasonal variations in ATR incidence in relation to injury mechanism, adverse events including risk of re-ru...
Article
Full-text available
PurposeThe aim of this study was to investigate whether patient subjective and functional outcomes after Achilles tendon rupture (ATR) are related to deep venous thrombosis (DVT) during leg immobilization.MethodsA cohort study with prospectively collected randomized data was conducted between 2010 and 2017. Two-hundred and fifty-one Patients with a...
Article
Full-text available
Mast cells are emerging as players in the communication between peripheral nerve endings and cells of the immune system. However, it is not clear the mechanism by which mast cells communicate with peripheral nerves. We previously found that mast cells located within healing tendons can express glutamate receptors, raising the possibility that mast...
Article
Full-text available
Background Functional deficits and health-related impairments are common after an Achilles tendon rupture (ATR). Rehabilitation protocols vary greatly, and few studies have allowed loading in combination with ankle motion immediately after surgery (ie, early functional mobilization [EFM]). It is unclear whether EFM may counteract the negative impac...
Article
Full-text available
Purpose The hypothesis was that early functional mobilization would reduce the incidence of deep venous thrombosis (DVT) during leg immobilization after Achilles tendon rupture surgery. A secondary aim was to evaluate if the amount of weightbearing and daily steps influenced the risk of sustaining a DVT. Methods One-hundred and fifty patients with...
Article
Full-text available
Purpose The purpose of this study was to determine patient-related and treatment-related predictors of superior and inferior function in sport and recreational activities 1 year after an Achilles tendon rupture. Methods This study is based on a multicentre cohort from 4 previous randomised controlled trials. All the patients who had responded to t...
Article
Full-text available
Background Acute Achilles tendon rupture (ATR) is a frequently disabling injury, which exhibits unclear variability in long‐term functional and patient‐reported outcomes. Biomarkers from early healing, which have been shown to be prognostic of long‐term outcome would facilitate the development of improved treatment methods. Hypothesis/Purpose The...
Article
Objective:. Many trauma patients are at risk of pulmonary embolism due to unrecognized deep vein thrombosis (DVT). Restricted ankle dorsiflexion (AD) range of motion during leg immobilization is known to cause reduced venous blood flow. The aim of the present study was to assess whether AD at plaster cast removal is related to the incidence of DVT...
Article
Background:: Mechanical loading is essential for tendon healing and may explain variability in patient outcomes after Achilles tendon rupture (ATR) repair. However, there is no consensus regarding the optimal postoperative regimen, and the actual amount of loading during orthosis immobilization is unknown. Purpose:: The primary aim of this study...
Article
Full-text available
The aim of this study was to compare the treatment effects of laser photobiomodulation (LPBM) therapy and aerobic exercise on the biomechanical properties, tissue morphology and the expression of tendon matrix molecules during early remodeling of Achilles tendon (AT) injury in diabetic rats. Animals were randomly assigned to five groups: injured no...
Data
The AT partial tenotomy injury model with an 18-gauge needle. (TIF)
Data
The moderate aerobic exercise protocol in a motorized treadmill. (MP4)
Article
Achilles tendinopathy (AT) is a continued enigma for clinicians from all parts around the world. The increasing prevalence is related to physical activities, but additionally also to metabolic factors unrelated to activities that load the Achilles tendon. AT can comprise two different diagnosis: insertional AT and non-insertional AT (NIAT). This re...
Preprint
Full-text available
Achilles Tendon Rupture (ATR) is one of the typical soft tissue injuries. Rehabilitation after such a musculoskeletal injury remains a prolonged process with a very variable outcome. Accurately predicting rehabilitation outcome is crucial for treatment decision support. However, it is challenging to train an automatic method for predicting ATR reha...
Article
Background: Patient outcome after an acute Achilles tendon rupture (ATR) continues to be suboptimal and heterogeneous. Thus, prognostic factors are called for to optimize evidence-based ATR treatment protocols; however, the influence of delayed time from injury to surgery (TTS) on patient outcome after ATR remains largely unknown. Purpose: To de...
Article
Achilles tendinopathy (AT), which is increasing in prevalence, continues to puzzle clinicians around the world. AT comprises insertional and non-insertional AT (NIAT). This review will deal with NIAT, which is often related to changes in activities in sports and occupation, but can also be unrelated to activities that load the Achilles tendon. Rece...
Preprint
Full-text available
Missing data are ubiquitous in many domains such as healthcare. Depending on how they are missing, the (conditional) independence relations in the observed data may be different from those for the complete data generated by the underlying causal process and, as a consequence, simply applying existing causal discovery methods to the observed data ma...
Conference Paper
Full-text available
Achilles Tendon Rupture (ATR) is one of the typical soft tissue injuries. Accurately predicting the rehabilitation outcome of ATR using noisy measurements with missing entries is crucial for treatment decision support. In this work, we design a probabilistic model that simultaneously predicts the missing measurements and the rehabilitation outcome...
Chapter
Targeted therapies of elbow tendinopathies have been limited due to lack of knowledge of the underlying pathophysiology. Recreational tennis players are mostly affected by the classical “tennis elbow”––humeral epicondylar lateral tendinopathy, while elite tennis players more commonly present with medial humeral epicondylar tendinopathy, reflecting...