Per Holmich

Copenhagen University Hospital, Amager-Hvidovre, Denmark · Sports Orthopedic Research Center-Copenhagen (SORC-C), Arthroscopic Center, Department of Orthopedic Surgery, Amager-Hvidovre University Hospital

Sleep inadequacy has previously been associated with increased risk of injury and reduced performance. It is unclear if sleep disorders are associated with musculoskeletal symptoms, which may be a predictor of serious injury and affect performance. The aim was therefore to assess sleep behavior in elite junior badminton players and its association...

Purpose To investigate the level of cellular senescence in stem cells derived from microfragmented abdominal adipose tissue harvested from patients with knee osteoarthritis (OA). Methods Stem cells harvested from microfragmented abdominal adipose tissue from 20 patients with knee OA, aged 29–65 years (mean = 49.8, SD = 9.58), were analysed as a fu...

Purpose The treatment of Rockwood type III AC joint dislocations has been debated for decades. In 2014, the International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine (ISAKOS) Upper Extremity Committee suggested a subclassification of the injury into type A, considered stable and best treated nonsurgically, and type B, consi...

Purpose We aimed to establish patient‐reported outcome measure (PROM) reference data for a cohort of patients with prior patellar dislocation without previous knee surgery. Methods All inhabitants of the Faroe Islands aged 15–19 years were sent an online survey via secure email to establish a national cohort. They were asked to answer questions re...

Background Knee pain affects one in three adolescents, which makes it one of the most common pain sites. Guideline recommendations about the clinical selection of patients likely to benefit from interventions are unclear, which leads to treatment heterogeneity and the potential of wasted resources among adolescents with a good prognosis. In contras...

Purpose To report how many badminton players return to badminton after an anterior cruciate ligament (ACL) injury and to which level. Methods Patients in Denmark from 2000 to 2018, registered in the Danish National Patient Register with a diagnosis of ACL rupture and badminton as a primary sport were asked about a return to sport (RTS) and return...

A skin marker-based motion capture model providing measures of scapular rotations was recently developed. The aim of this study was to investigate the concurrent validity and the interrater reliability of the model. Shoulder range of motion (RoM) and activities of daily living (ADL) were tested in healthy volunteers with reflective markers on the s...

Background The effects of specific bony hip morphologies, cam and dysplasia, and cartilage damage on mid- and long-term (≥5 years) patient-reported outcomes (PROs) are understudied. Purpose To investigate if changes in PROs from preoperatively to 5 years after hip arthroscopy are associated with preoperative bony hip morphology and cartilage statu...

OBJECTIVE: To compare the effect of early meniscal surgery versus exercise and education with the option of later surgery on pain, function, and quality of life in young patients with a meniscal tear, taking symptom onset into account. DESIGN: Randomized controlled trial. METHODS: In a randomized controlled trial (the “Danish RCT on Exercise versus...

Purpose Acromioclavicular (AC) joint dislocations are common injuries, but the indication for and timing of surgery is debated. The objective of the study was to evaluate the results after acute AC joint dislocations Rockwood type III and V treated nonsurgically with the option of delayed surgical intervention. Methods This is a prospective cohort...

Introduction Subacromial pain syndrome (SAPS) lacks recognized diagnostic criteria. This could lead to important variations in concomitant shoulder diagnoses across populations. Knowledge of this could lead to an individualized approach, improving the overall handling of patients with SAPS. The aim was to investigate the prevalence of concomitant s...

Introduction To calculate the prevalence of patellar dislocation (PD) and trochlear dysplasia (TD) in a national cohort in the Faroe Islands. Material and Methods All inhabitants in The Faroe Islands aged 15 to 19 years were invited to answer an online survey. Three cohorts were established: 1) The background cohort consisting of the participants...

Introduction To investigate patient reported outcome measurement (PROM) reference data on a national cohort of patients between 15-19 years with prior patella dislocation and trochlear dysplasia. Material and Methods All inhabitants in the Faroe Islands between 15 to 19 years were invited to answer an online survey. The survey included questions c...

Introduction Patients with subacromial pain syndrome (SAPS) are typically referred to physiotherapy as first line of treatment. Only half of patients get a satisfactory treatment outcome from this. Acromial morphology, poor scapular control, and impingement are pathophysiological factors associated with SAPS. These are expressed varyingly in SAPS-p...

Background and purpose We aimed to calculate the prevalence of patellar dislocation (PD) and trochlear dysplasia (TD) in a national cohort aged 15–19 years in the Faroe Island. Patients and methods All inhabitants in the Faroe Islands aged 15–19 years were invited to answer an online survey, including demographics and questions regarding prior PD....

Pros and cons of using autologous versus allogenic stem cells for the treatment of osteoarthritis Intraarticular treatment of osteoarthritis with mesenchymal stem cells (MSCs) has shown promising results and is being increasingly implemented in the clinic. Autologous MSCs are the primary source of therapy but issues related to cell expansion, patie...

Background Surgical treatment of acute Achilles tendon rupture (ATR) lowers the risk of rerupture and may reduce calf atrophy and elongation of the Achilles tendon. The Copenhagen Achilles Rupture Treatment Algorithm (CARTA) was developed to provide individualized treatment selection based on ultrasonographic evaluation of the rupture. Purpose In...

Objective To investigate potential differences in structural knee joint damage assessed by MRI and patient-reported outcomes (PROMs) at 2-year follow-up between young adults randomised to early surgery or exercise and education with optional delayed surgery for a meniscal tear. Methods A secondary analysis of a multicentre randomised controlled tr...

Background Reports of glenohumeral translation in shoulders with traumatic anterior instability have been presented. The aim of this systematic review was to investigate anterior-posterior translation in shoulders with traumatic anterior instability. Methods This systematic review follows the Preferred Reporting Items for Systematic Reviews and Me...

Background: An Achilles tendon rupture (ATR) is a frequent injury and results in the activation of tendon cells and collagen expression, but it is unknown to what extent turnover of the tendon matrix is altered before or after a rupture. Purpose/hypothesis: The purpose of this study was to characterize tendon tissue turnover before and immediate...

Objectives: To describe the Quality of Life (QoL) among adolescents with Patellofemoral Pain (PFP) and Osgood-Schlatter Disease (OSD) and investigate characteristics associated with QoL. Study design: Cross-sectional. Participants: 316 adolescents with PFP or OSD. Main outcome measures: QoL subscale of The Knee injury and Osteoarthritis Outc...

Objective: Although hip arthroscopy is a widely adopted treatment option for hip-related pain, it is unknown whether preoperative clinical information can be used to assist surgical decision-making to avoid offering surgery to patients with limited potential for a successful outcome. We aimed to develop and validate clinical prediction models to i...

Purpose: To investigate if viable stem cells could be isolated and expanded from cryopreserved microfragmented adipose tissue (AT) harvested from patients with knee osteoarthritis. Methods: Microfragmented abdominal AT from knee osteoarthritis patients was cryopreserved at -80 °C in cryoprotectant-medium. The samples were thawed for stem cell is...

Objective The primary aim was to investigate the effectiveness of adding more resistance exercise to usual care on pain mechanisms (including temporal summation, conditioned pain modulation (CPM) and local pain sensitivity) and pain catastrophising in people with subacromial impingement at 16 weeks follow-up. Second, to investigate the modifying ef...

Objective: To compare the effect of early surgery versus exercise and education on mechanical symptoms and other patient-reported outcomes in patients aged 18-40 years with a meniscal tear and self-reported mechanical knee symptoms. Methods: In a randomised controlled trial, 121 patients aged 18-40 years with a MRI-verified meniscal tear were ra...

Purpose: The aim of the study was to perform a systematic review and best knowledge synthesis of the present literature concerning biomechanical risk factors for developing first-time and recurrent patella dislocation. Methods: The study was performed as a systematic review following PRISMA guidelines. PubMed and EMBASE were systematically searc...

Introduction There is no recognised terminology, nor diagnostic criteria, for patients with subacromial pain syndrome (SAPS). This is likely to cause heterogeneity across patient populations. This could be a driver of misconceptions and misinterpretations of scientific results. We aimed to map the literature regarding terminology and diagnostic cri...

Introduction Acromioclavicular(AC) joint dislocations are common injuries, but the need for surgery is debated. The objective of the study was to evaluate the result after acute Rockwood type III and V AC joint dislocations managed non-surgically with the option of delayed surgical intervention. Materials and Methods This was a prospective cohort...

Background Osgood-Schlatter is a common growth-related condition in adolescence and can cause persistent symptoms and decrease quality of life. However, little is known about its long-term consequences for knee-related health in adulthood. Aim To investigate self-reported knee health of adults diagnosed with Osgood-Schlatter during adolescence com...

Background ISAKOS upper extremity committee has suggested a subclassification of Rockwood type III acromioclavicular(AC) joint dislocations in a stable type A recommended non-surgical treatment and an unstable type B recommended surgical treatment. The objective of this prospective cohort study was to investigate if this subclassification is clinic...

Introduction Pain provocation tests are used to examine and classify longstanding groin pain into clinical entities as adductor-, iliopsoas-, inguinal- and pubic-related. It is unknown if pain provocation tests and clinical entities are associated with pain intensity and disability. We aim to investigate if the numbers of positive pain provocation...

Background The treatment of Rockwood type III/V acromioclavicular(AC) joint dislocations is debated. The objective of this prospective cohort study was to investigate the association between demographical, clinical, patient-reported and radiological variables at baseline/6w with the result after 3m, 6m and 1y. Methods Inclusion criteria were patie...

Introduction A common treatment strategy to alleviate mechanical symptoms in young patients with meniscal tears is meniscal surgery, however, it is unknown whether this is superior to a non-surgical strategy. Therefore, we aimed to compare meniscal surgery to early exercise therapy and patient education. Materials and Methods In a randomized contr...

Introduction Treatment of knee osteoarthritis with stem cells from microfragmented adipose tissue (AT) has shown promising results. Cryopreservation and biobanking of stem cells are important for research, treatment of aged patients, and for repetitive treatments. Our aim was, therefore, to investigate if viable stem cells could be isolated and exp...

Introduction We aimed to describe Quality of life (QoL) among adolescents with Patellofemoral Pain (PFP) and Osgood-Schlatter Disease (OSD) according to the QoL subscale of The Knee injury and Osteoarthritis Outcome Score (KOOS) and the EuroQol 5-dimensions (EQ-5D) and to investigate the characteristics associated with QoL. Methods This individual...

PurposeThe aim of our study was to perform a systematic review and best knowledge synthesis of the present literature concerning the familial association and epidemiological factors as risk factors for developing first-time and recurrent patella dislocation.Methods The study was conducted according to the PRISMA guidelines and registered in PROSPER...

Background Clinical examination of male football players with longstanding groin pain can be considered difficult. Pain provocation tests are used to examine and classify longstanding groin pain into clinical entities as adductor-, iliopsoas-, inguinal-, and pubic-related. It is unknown if pain provocation tests and clinical entities are associated...

Background Individual treatment selection has been proposed as the key to optimized treatment. The purpose was to investigate if treatment selection using the individualized treatment algorithm Copenhagen Achilles Rupture Treatment Algorithm (CARTA) differs between patients treated as usual regarding gait dynamics and tendon elongation. Methods Th...

Introduction Previous studies showed that the Nordic hamstring exercise (NHE) effectively prevents primary hamstring injury. However, no study investigated the secondary preventing effect of the NHE on hamstring reinjury. The primary purpose of this study is to investigate the effectiveness of the NHE for preventing hamstring reinjury after return...

Introduction Acromioclavicular (AC) joint dislocations are common, but basic epidemiological features and sub-classification are not well investigated. The aim of the study was to investigate the incidence and epidemiology of acute AC joint dislocations in the capital region of Denmark. Methods All patients with acute AC joint dislocation admitted...

Background The best choice of orthosis in the treatment of acute Achilles tendon rupture is still under debate. Objective To investigate if choice of orthosis in the first 3 weeks of treatment affected patient reported outcome (Achilles tendon Total Rupture Score (ATRS)), tendon elongation (Achilles Tendon Resting Angle (ATRA) and Heel Rise Height...

Background The source of the pathological changes that occur before an acute Achilles tendon rupture (ATR) is not fully understood. Bacterial DNA has previously been detected in samples from ruptured Achilles tendons, suggesting a pathogenic role of bacteria in ATR. Purpose/Hypothesis The purpose of this study was to investigate if DNA from bacter...

Orthoses are an important part of both conservative and operative treatment of acute Achilles tendon rupture as they can be used to position the foot in equinus and protect the torn tendon from strain in the healing phase. The aim of the study was to test four different orthoses ability to position the foot in equinus. The study was performed as a...

Purpose: To investigate the differences in hip adductor and abductor muscle strength in elite male footballers from youth to senior level. Methods: We tested 125 players from the under-13-years (U'13) to senior squads of a Danish male professional football club in this cross-sectional design study. Hip adductor and abductor force (in newtons), t...

Background Differences in shoulder-disability among common shoulder-disorders in orthopaedic specialist care is unknown. Furthermore, rating of shoulder-disability using patient-reported outcomes is time-consuming, and a faster approach is needed. Objectives First, compare shoulder-disability among common shoulder-disorders. Secondly, rate shoulde...

Achilles tendon (AT) rupture is common among recreational male badminton players. We hypothesize that a landing technique following forehand jump strokes with the landing foot in a neutral position often performed by recreational players and occasionally by elite players may expose the AT to higher loads than a scissor kick jump (SKJ) technique wit...

Elongation of the tendon has been proposed as the most important factor leading to poor outcome after acute Achilles tendon rupture (ATR). The aim of this paper was to investigate if Amlang's ultrasound classification (AmC) or the Copenhagen Achilles Length Measurement (CALM) when assessed in the acute phase after ATR could predict elongation 1 yea...

Objectives To compare long-lever squeeze testing using the ForceFrame and the Copenhagen 5-Second-Squeeze test (5SST) for assessment of hip adduction strength and provoked groin pain in elite male soccer players. Design Cross-sectional study. Setting Pre-season testing at facilities of a Danish professional 1er soccer club and academy. Participa...

Background: Ankle sprain is the most common type of sports injury, especially in team sports. Standing and dynamic landing balance, as an indicator of ankle instability, were investigated using varying experimental approaches. Methods: In the present cross-sectional study, 81 adolescent female elite handball and football players were divided int...

Background It is unknown if genetics contribute to the etiology of acute Achilles tendon rupture (ATR). The aims of the present study were, 1) To calculate the concordance rate for monozygotic (MZ) twins and same-sex dizygotic (SSDZ) twins and 2) to estimate the heritability of ATR. Methods The study was performed as a registry study using the Dan...

Acute and long-standing groin injuries are a substantial problem in many sports including the various disciplines of athletics. The most common causes of groin pain are adductor- and iliopsoas-related. Athletes presenting with groin pain should follow a standardized diagnostic examination including subjective history taking, specific examination te...

Objectives The prevalence of pain medication use for adolescent knee pain and factors associated with use are not well understood. This study aimed to determine the self-reported use of pain medication for knee pain and identify factors associated with use in adolescents (age 10–19) with longstanding knee symptoms. Methods In this exploratory cros...

Bkground No studies have tested the validity of the Copenhagen Hip and Groin Outcome Score (HAGOS) using modern test theory, across different cultures and languages. Objective To validate the Danish, English and Norwegian versions of HAGOS and its six subscales (Symptoms (S, Item 1–7), Pain (P, Item 1–10), activities of daily living (Item 1–5), Sp...

Badminton is played with repetitive high loading to the hip with lunging and jumps. In sports like soccer there is a high prevalence of femoroacetabular impingement syndrome in youth populations which may predispose them to osteoarthritis (OA). Internal rotation deficit in the hip of football players is a predictor of hip and groin pain and differe...

Objective To test if 1) the 45-s Anterior Knee Pain Provocation Test (AKPP-test) could differentiate between adolescents with patellofemoral pain (PFP) and pain-free controls and; 2) whether improvements in the AKPP-test over 12 weeks were associated with improvements in self-reported knee function and pain. Design Prospective cohort. Patients 15...

Background Knowledge is limited about how Achilles tendon elongation following acute Achilles tendon rupture (ATR) affects the ability to return to work and return to sport. This study aimed to examine if the indirect length measures, the heel-rise height (HRH) and the Achilles tendon resting angle (ATRA), correlated with patient limitations and re...

Background The hamstring muscle strengthening is an integral part of validated injury prevention programs in football. However, it is unknown whether hamstring muscle strengthening exercises are used in female elite football. Objective To investigate the use of hamstring muscle strengthening in female elite football training. Design Descriptive,...

Background Adolescent athletes have different injury patterns to those of adults, and their growing bones are susceptible to overuse injuries. Evidence of growth-related injuries in relation to growth and maturation in youth elite soccer players remains sparse. Objective 1) to investigate lower-limb apophyseal injuries (LL-AI) and 2) their relatio...

Background Osteoarthritis is a destructive joint disease that leads to degeneration of cartilage and other morphological changes in the joint. No medical treatment currently exists that can reverse these morphological changes. Intra-articular injection with autologous, micro-fragmented adipose tissue has been suggested to relieve symptoms. Methods...

Interpretation of the Achilles tendon Total Rupture Score (ATRS) is challenging because limited knowledge exists about at which score the patients consider the outcome of treatment as satisfactory. The aims of the study were 1) to describe the proportion of patients who find their symptom levels to be satisfactory, to reflect treatment failure or n...

This statement summarises and appraises the evidence on diagnostic tests and clinical information, and non-operative treatment of femoroacetabular impingement (FAI) syndrome and labral injuries. We included studies based on the highest available level of evidence as judged by study design. We evaluated the certainty of evidence using the Grading of...

Purpose: Retraction of semitendinosus muscle has been reported after reconstruction of the anterior cruciate ligament with semitendinosus/gracilis-graft. However, very little data exist on the natural variation in side-to-side length symmetry. The purpose of this study was to investigate the side-to-side asymmetry of semitendinosus muscle length i...

Background: Hamstring injuries remain a major burden in football while the effective prevention exercise the Nordic Hamstring is poorly adopted, despite the added positive effects on performance. Better understanding of hamstring function during Nordic Hamstring compared to other exercises may provide better insight to the physiological adaptation...

Background Osgood-Schlatter disease (OSD), an apophyseal injury of the tibial tuberosity, affects up to 1 in 10 adolescents. This condition has previously been assumed to be innocuous and to self-resolve with limited intervention. Purpose To investigate the 24-month prognosis of OSD and examine if ultrasound (US) classification is associated with...

To report the minimum 5-year outcome after hip arthroscopy with labral repair in adolescents. From 2011 to 2014, 29 consecutive patients with a mean age 16.3 years (range 12.7–19.8 years) underwent hip arthroscopy treatment for femoroacetabular impingement syndrome. Patient-related outcome measures (PROMs) including modified Harris Hip Score (mHHS)...

Objectives Evaluate the adoption of and opinions on the Doha agreement meeting classification in groin pain in athletes. Design Delphi survey and e-survey. Methods A 2-round Delphi survey among the Doha agreement meeting expert group, and a separate international e-survey among clinicians who regularly assess athletes with groin pain. Clinical ca...

Background Complete avulsions of the adductor longus tendon are serious injuries, yet we have few data to inform clinical decisions on management. Previous studies are limited by a lack of detailed follow-up. Purpose To describe detailed clinical and imaging measures 1 year after complete proximal adductor longus avulsion injuries in athletes who...

Background: It has been indicated that anterior cruciate ligament reconstruction (ACLR) with a quadriceps tendon (QT) graft has a higher risk of revision compared with ACLR performed with a hamstring tendon (HT) graft. Purpose/hypothesis: To investigate whether ACLR with QT graft had a higher risk of graft failure, revision ACLR, or reoperation...

Background: A strong recommendation against subacromial decompression surgery was issued in 2019. This leaves nonoperative care as the only treatment option, but recent studies suggest that the dose of strengthening exercise is not sufficient in current nonoperative care. At this point, it is unknown if adding more strengthening to current nonoper...