Jonas Bloch Thorlund

Arthroscopic surgery for degenerative knee: systematic review and meta-analysis of benefits and harms

Objective To determine benefits and harms of arthroscopic knee surgery involving partial meniscectomy, debridement, or both for middle aged or older patients with knee pain and degenerative knee disease. Design Systematic review and meta-analysis. Main outcome measures Pain and physical function. Data sources Systematic searches for benefits and harms were carried out in Medline, Embase, CINAHL, Web of Science, and the Cochrane Central Register of Controlled Trials (CENTRAL) up to August 2014. Only studies published in 2000 or later were included for harms. Eligibility criteria for selecting studies Randomised controlled trials assessing benefit of arthroscopic surgery involving partial meniscectomy, debridement, or both for patients with or without radiographic signs of osteoarthritis were included. For harms, cohort studies, register based studies, and case series were also allowed. Results The search identified nine trials assessing the benefits of knee arthroscopic surgery in middle aged and older patients with knee pain and degenerative knee disease. The main analysis, combining the primary endpoints of the individual trials from three to 24 months postoperatively, showed a small difference in favour of interventions including arthroscopic surgery compared with control treatments for pain (effect size 0.14, 95% confidence interval 0.03 to 0.26). This difference corresponds to a benefit of 2.4 (95% confidence interval 0.4 to 4.3) mm on a 0–100 mm visual analogue scale. When analysed over time of follow-up, interventions including arthroscopy showed a small benefit of 3–5 mm for pain at three and six months but not later up to 24 months. No significant benefit on physical function was found (effect size 0.09, −0.05 to 0.24). Nine studies reporting on harms were identified. Harms included symptomatic deep venous thrombosis (4.13 (95% confidence interval 1.78 to 9.60) events per 1000 procedures), pulmonary embolism, infection, and death. Conclusions The small inconsequential benefit seen from interventions that include arthroscopy for the degenerative knee is limited in time and absent at one to two years after surgery. Knee arthroscopy is associated with harms. Taken together, these findings do not support the practise of arthroscopic surgery for middle aged or older patients with knee pain with or without signs of osteoarthritis. Systematic review registration PROSPERO CRD42014009145.

Acute fatigue-induced changes in muscle mechanical properties and neuromuscular activity in elite handball players following a handball match

The purpose of the present study was to determine the acute fatigue development in muscle mechanical properties and neuromuscular activity in response to handball match play. Male elite handball players (n= 10) were tested before and after a simulated handball match for maximal isometric strength [maximal voluntary contraction (MVC)] and rate of force development (RFD) with synchronous electromyography (EMG) recording, while maximal vertical jump parameters were assessed using force plate analysis. Quadriceps and hamstrings MVC and RFD decreased significantly post‐match (∼10%, P<0.05 and ∼16–21%, P<0.05, respectively). During quadriceps, MVC mean EMG amplitude [mean average voltage (MAV)] decreased for the vastus lateralis (VL) and rectus femoris (RF) (21–42%, P≤0.05), while MAV also decreased in the antagonist biceps femoris (BF) muscle (48–55%, P<0.01). During hamstring MVC, MAV was reduced in BF (31%, P<0.01). Maximum EMG amplitude during quadriceps MVC was reduced for the VL (28%, P<0.01) and the RF (5%, P<0.05). During hamstring MVC, maximum EMG was reduced for BF (21%, P<0.01). Post‐match maximal jump height was reduced (5.2%, P<0.01), as was also work (6.8%, P<0.01), velocity of center of mass (2.4–4.0%, P<0.01) and RFD (∼30%, P<0.05). In conclusion, maximal (MVC) and rapid muscle force characteristics (RFD, impulse) were acutely affected concurrently with marked reductions in muscle EMG following handball match play, which may potentially lead to impaired functional performance.

Rapid Muscle Force Capacity Changes after Soccer Match Play

The present study examined the fatigue development in muscle mechanical properties with emphasis on rapid force characteristics and neuromuscular activity in response to high level soccer match play. Young elite soccer players (n=9) were tested before (CON) and after (POST) a soccer match for maximal knee extensor and flexor isometric strength (MVC) and contractile rate of force development (RFD) with synchronous surface electromyography (EMG) recording. Furthermore, maximal vertical jump power and related parameters were assessed. Isometric knee extensor and flexor MVC decreased approximately 10% (p< or =0.01) along with a right-shift in the moment-time curve. RFD decreased approximately 9% (0-200 ms) for the knee flexors while there was a tendency towards reduced RFD during knee extension following soccer match play. Similar reductions were observed for some but not all selected EMG parameters during the MVC and RFD tests. Mechanical jump parameters generally remained unchanged post match play. This study is the first to examine the fatigue induced changes in rapid muscle force production (RFD) induced by soccer match play. The observed decrement in rapid muscle force capacity is likely to have negative impact on performance in explosive playing actions (i.e. accelerations, kicking, sprinting) that typically is involved in soccer match play.

Large increase in arthroscopic meniscus surgery in the middle-aged and older population in Denmark from 2000 to 2011

Background — Arthroscopic meniscal surgery is the most common orthopedic procedure, and the incidence has increased in Denmark over the last 10 years. Concomitantly, several randomized controlled trials have shown no benefit of arthroscopic procedures including arthroscopic partial meniscectomy in middle-aged and older individuals suffering from knee pain with or without knee osteoarthritis. We examined the annual incidence of meniscal procedures together with age, sex, and diagnosis for patients who underwent meniscal procedures in the period 2000–2011 in Denmark. Methods — Data on age, sex, diagnosis, and surgical procedures were extracted from the Danish National Patient Register for the years 2000–2011, for all records containing meniscal surgery as a primary or secondary procedure. Results — The overall annual incidence of meniscal procedures per 100,000 persons in Denmark doubled from 164 in 2000 to 312 in 2011 (i.e. 8,750 procedures to 17,368 procedures). A 2-fold increase was found for patients aged between 35 and 55, and a 3-fold increase was found for those older than 55. Middle-aged and older patients accounted for 75% of all 151,228 meniscal procedures carried out between 2000 and 2011. Interpretation — The incidence of meniscal procedures performed in Denmark doubled from 2000 to 2011, with the largest increase in middle-aged and older patients. This increase contrasts with the mounting evidence showing no added benefit of arthroscopic partial meniscectomy over non-surgical treatments. Our observations illustrate the long delay in the dissemination, acceptance, and implementation of research evidence into the practice of arthroscopic surgery.

Knee extensor muscle weakness is a risk factor for development of knee osteoarthritis. A systematic review and meta-analysis

The objective of this study was to perform a systematic review and meta-analysis on the association between knee extensor muscle weakness and the risk of developing knee osteoarthritis. A systematic review and meta-analysis was conducted with literature searches in Medline, SPORTDiscus, EMBASE, CINAHL, and AMED. Eligible studies had to include participants with no radiographic or symptomatic knee osteoarthritis at baseline; have a follow-up time of a minimum of 2 years, and include a measure of knee extensor muscle strength. Hierarchies for extracting data on knee osteoarthritis and knee extensor muscle strength were defined prior to data extraction. Meta-analysis was applied on the basis of the odds ratios (ORs) of developing symptomatic knee osteoarthritis or radiographic knee osteoarthritis in subjects with knee extensor muscle weakness. ORs for knee osteoarthritis and 95% confidence intervals (CI) were estimated and combined using a random effects model. Twelve studies were eligible for inclusion in the meta-analysis after the initial searches. Five cohort studies with a follow-up time between 2.5 and 14 years, and a total number of 5707 participants (3553 males and 2154 females), were finally included. The meta-analysis showed an overall increased risk of developing symptomatic knee osteoarthritis in participants with knee extensor muscle weakness (OR 1.65 95% CI 1.23, 2.21; I(2) = 50.5%). This systematic review and meta-analysis showed that knee extensor muscle weakness was associated with an increased risk of developing knee osteoarthritis in both men and women.

Range of motion, neuromechanical, and architectural adaptations to plantar flexor stretch training in humans

The neuromuscular adaptations in response to muscle stretch training have not been clearly described. In the present study, changes in muscle (at fascicular and whole muscle levels) and tendon mechanics, muscle activity, and spinal motoneuron excitability were examined during standardized plantar flexor stretches after 3 wk of twice daily stretch training (4 × 30 s). No changes were observed in a nonexercising control group (n = 9), however stretch training elicited a 19.9% increase in dorsiflexion range of motion (ROM) and a 28% increase in passive joint moment at end ROM (n = 12). Only a trend toward a decrease in passive plantar flexor moment during stretch (-9.9%; P = 0.15) was observed, and no changes in electromyographic amplitudes during ROM or at end ROM were detected. Decreases in H(max):M(max) (tibial nerve stimulation) were observed at plantar flexed (gastrocnemius medialis and soleus) and neutral (soleus only) joint angles, but not with the ankle dorsiflexed. Muscle and fascicle strain increased (12 vs. 23%) along with a decrease in muscle stiffness (-18%) during stretch to a constant target joint angle. Muscle length at end ROM increased (13%) without a change in fascicle length, fascicle rotation, tendon elongation, or tendon stiffness following training. A lack of change in maximum voluntary contraction moment and rate of force development at any joint angle was taken to indicate a lack of change in series compliance of the muscle-tendon unit. Thus, increases in end ROM were underpinned by increases in maximum tolerable passive joint moment (stretch tolerance) and both muscle and fascicle elongation rather than changes in volitional muscle activation or motoneuron pool excitability.

Patient reported outcomes in patients undergoing arthroscopic partial meniscectomy for traumatic or degenerative meniscal tears: comparative prospective cohort study

Objectives To compare patient reported outcomes from before surgery to 52 weeks after surgery between individuals undergoing arthroscopic partial meniscectomy for traumatic meniscal tears and those for degenerative meniscal tears. Design Comparative prospective cohort study. Setting Four public orthopaedic departments in the Region of Southern Denmark. Participants were recruited between 1 February 2013 and 31 January 2014, and at one of the original four hospitals from 1 February 2014 to 31 January 2015. Participants Individuals selected from Knee Arthroscopy Cohort Southern Denmark, aged 18-55, and undergoing arthroscopic partial meniscectomy for a traumatic or degenerative meniscal tear (defined by a combination of age and symptom onset). Interventions Both participant groups underwent arthroscopic partial meniscectomy for a meniscal tear, with operating surgeons recording relevant information on knee pathology. Patient reported outcomes were recorded via online questionnaires. Main outcome measures Primary outcome was the average between-group difference in change on four of five subscales of the knee injury and osteoarthritis outcome score (KOOS). The four subscales covered pain, symptoms, sport and recreational function, and quality of life (KOOS4). A 95% confidence interval excluding differences greater than 10 KOOS points between groups was interpreted as absence of a clinically meaningful difference. Analyses adjusted for age, sex, and body mass index. Results 397 eligible adults (42% women) with a traumatic or degenerative meniscal tear (n=141, mean age 38.7 years (standard deviation 10.9); n=256, 46.6 years (6.4); respectively) were included in the main analysis. At 52 weeks after arthroscopic partial meniscectomy, 55 (14%) patients were lost to follow-up. Statistically, participants with degenerative meniscal tears had a significantly larger improvement in KOOS4 scores than those with traumatic tears (adjusted between-group difference −5.1 (95% confidence interval −8.9 to −1.3); P=0.008). In the analysis including KOOS4 score at all time points, a significant time-by-group interaction was observed in both the unadjusted (P=0.025) and adjusted analysis (P=0.024), indicating better self-reported outcomes in participants with degenerative tears. However, the difference between groups was at no time point considered clinically meaningful. Conclusions These results question the current tenet that patients with traumatic meniscal tears experience greater improvements in patient reported outcomes after arthroscopic partial meniscectomy than patients with degenerative tears. Trial registration ClinicalTrials.gov identifier NCT01871272.

Thigh muscle strength, functional capacity, and self‐reported function in patients at high risk of knee osteoarthritis compared with controls

Reduced muscle strength is suggested as a risk factor for knee osteoarthritis (OA). Meniscectomy patients have an increased risk of developing knee OA. The aim of this study was to identify reductions in different aspects of muscle strength as well as objectively measured and self‐reported lower extremity function in middle‐aged patients who had undergone a meniscectomy compared with controls.

Structural pathology is not related to patient-reported pain and function in patients undergoing meniscal surgery

Background The relationship between meniscal tears and other joint pathologies with patient-reported symptoms is not clear. We investigated associations between structural knee pathologies identified at surgery with preoperative knee pain and function in patients undergoing arthroscopic meniscal surgery. Methods This study included 443 patients from the Knee Arthroscopy Cohort Southern Denmark (KACS), a prospective cohort following patients 18 years or older undergoing arthroscopic meniscal surgery at 4 hospitals between 1 February 2013 and 31 January 2014. Patient-reported outcomes, including the Knee Injury and Osteoarthritis Outcome Score (KOOS), were obtained by online questionnaires prior to surgery. Knee pathology was assessed by the operating surgeons using a modified version of the International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine (ISAKOS) classification of meniscal tears questionnaire, supplemented with information extracted from surgery reports. Following hypothesis-driven preselection of candidate variables, backward elimination regressions were performed to investigate associations between patient-reported outcomes and structural knee pathologies. Results Regression models only explained a small proportion of the variability in self-reported pain and function (adjusted R2=0.10−0.12) and this association was mainly driven by age, gender and body mass index. Conclusions Specific meniscal pathology and other structural joint pathologies found at meniscal surgery were not associated with preoperative self-reported pain and function in patients with meniscal tears questioning inferences made about a direct relationship between these. Our findings question the role of arthroscopic surgery to address structural pathology as a means to improve patient-reported outcomes in patients having surgery for a meniscal tear.

Stretch-shortening cycle muscle power in women and men aged 18-81 years: Influence of age and gender.

This study explored the age‐related deterioration in stretch‐shortening cycle (SSC) muscle power and concurrent force–velocity properties in women and men across the adult life span.