Michael Skovdal Rathleff

A Randomized, Controlled Trial of Total Knee Replacement

BACKGROUND More than 670,000 total knee replacements are performed annually in the United States; however, high-quality evidence to support the effectiveness of the procedure, as compared with nonsurgical interventions, is lacking. METHODS In this randomized, controlled trial, we enrolled 100 patients with moderate-to-severe knee osteoarthritis who were eligible for unilateral total knee replacement. Patients were randomly assigned to undergo total knee replacement followed by 12 weeks of nonsurgical treatment (total-knee-replacement group) or to receive only the 12 weeks of nonsurgical treatment (nonsurgical-treatment group), which was delivered by physiotherapists and dietitians and consisted of exercise, education, dietary advice, use of insoles, and pain medication. The primary outcome was the change from baseline to 12 months in the mean score on four Knee Injury and Osteoarthritis Outcome Score subscales, covering pain, symptoms, activities of daily living, and quality of life (KOOS4); scores range from 0 (worst) to 100 (best). RESULTS A total of 95 patients completed the 12-month follow-up assessment. In the nonsurgical-treatment group, 13 patients (26%) underwent total knee replacement before the 12-month follow-up; in the total-knee-replacement group, 1 patient (2%) received only nonsurgical treatment. In the intention-to-treat analysis, the total-knee-replacement group had greater improvement in the KOOS4 score than did the nonsurgical-treatment group (32.5 vs. 16.0; adjusted mean difference, 15.8 [95% confidence interval, 10.0 to 21.5]). The total-knee-replacement group had a higher number of serious adverse events than did the nonsurgical-treatment group (24 vs. 6, P=0.005). CONCLUSIONS In patients with knee osteoarthritis who were eligible for unilateral total knee replacement, treatment with total knee replacement followed by nonsurgical treatment resulted in greater pain relief and functional improvement after 12 months than did nonsurgical treatment alone. However, total knee replacement was associated with a higher number of serious adverse events than was nonsurgical treatment, and most patients who were assigned to receive nonsurgical treatment alone did not undergo total knee replacement before the 12-month follow-up. (Funded by the Obel Family Foundation and others; MEDIC ClinicalTrials.gov number, NCT01410409.).

Is hip strength a risk factor for patellofemoral pain? A systematic review and meta-analysis

Objective To evaluate and synthesise the literature on hip strength among patients with patellofemoral pain (PFP) to address the following: (1) differentiate between hip strength as a risk factor and associated deficit in PFP; (2) describe hip strength in men and women with PFP across different age ranges; (3) investigate the effects of hip strengthening on biomechanical knee variables associated with PFP development. Methods MEDLINE, CINAHL, Web of Science, SportDiscus and Google Scholar were searched in November 2013 for studies investigating hip strength among patients with PFP. Two reviewers independently assessed papers for inclusion and quality. Means and SDs were extracted from each included study to allow effect size calculations and comparisons of results. Results Moderate-to-strong evidence from prospective studies indicates no association between isometric hip strength and risk of developing PFP. Moderate evidence from cross-sectional studies indicates that men and women with PFP have lower isometric hip musculature strength compared to pain-free individuals. Limited evidence indicates that adolescents with PFP do not have the same strength deficits as adults with PFP. Conclusions This review highlights a possible discrepancy between prospective and cross-sectional research. Cross-sectional studies indicate that adult men and women with PFP appear to have lower hip strength compared to pain-free individuals. Contrary to this, a limited number of prospective studies indicate that there may be no association between isometric hip strength and risk of developing PFP. Therefore, reduced hip strength may be a result of PFP rather than the cause.

Patellofemoral Pain Syndrome and Its Association with Hip, Ankle, and Foot Function in 16- to 18-Year-Old High School Students: A Single-blind Case-control Study

BACKGROUND An increased pronated foot posture is believed to contribute to patellofemoral pain syndrome (PFPS), but the relationship between these phenomena is still controversial. The objectives of this study were to investigate the prevalence of PFPS in high school students and to compare passive internal and external hip rotation, passive dorsiflexion, and navicular drop and drift between healthy high school students and students with PFPS. METHODS All 16- to 18-year-old students in a Danish high school were invited to join this single-blind case-control study (N = 299). All of the students received a questionnaire regarding knee pain. The main outcome measurements were prevalence of PFPS, navicular drop and drift, passive ankle dorsiflexion, passive hip rotation in the prone position, and activity level. The case group consisted of all students with PFPS. From the same population, a randomly chosen control group was formed. RESULTS The prevalence of knee pain was 25%. Of the 24 students with knee pain, 13 were diagnosed as having PFPS. This corresponds to a PFPS prevalence of 6%. Mean navicular drop and drift were higher in the PFPS group versus the control group (navicular drop: 4.2 mm [95% confidence interval (CI), 3.2-5.3 mm] versus 2.9 mm [95% CI, 2.5-3.3 mm]; and navicular drift: 2.6 mm [95% CI, 1.6-3.7 mm] versus 1.4 mm [95% CI, 0.9-2.0 mm]). Higher passive ankle dorsiflexion was also identified in the PFPS group (22.2° [95% CI, 18°-26°] versus 17.7° [95% CI, 15°-20°]). CONCLUSIONS This study demonstrated greater navicular drop, navicular drift, and dorsiflexion in high school students with PFPS compared with healthy students and highlights that foot posture is important to consider as a factor where patients with PFPS diverge from healthy individuals.

Lower Mechanical Pressure Pain Thresholds in Female Adolescents With Patellofemoral Pain Syndrome

STUDY DESIGN Cross-sectional study. OBJECTIVES To compare pressure pain thresholds (PPTs) between adolescent females diagnosed with patellofemoral pain syndrome (PFPS) and gender- and age-matched controls without musculoskeletal pain. BACKGROUND PFPS is prevalent among adolescents and may be associated with reduced PPT both locally and remotely from the site of reported pain. This may indicate altered central processing of nociceptive information. However, this has never been investigated in adolescents with PFPS. METHODS Adolescents with PFPS and a comparison group without musculoskeletal pain were recruited from a population-based cohort of students from 4 upper secondary schools, aged 15 to 19 years. All 2846 students within that age range were invited to answer an online questionnaire regarding musculoskeletal pain. The students who reported knee pain were contacted by telephone and offered a clinical examination by an experienced rheumatologist, who made a diagnosis. PPTs were measured at 4 sites around the knee and 1 site on the tibialis anterior in the 57 female adolescents diagnosed with PFPS and in 22 female adolescents without musculoskeletal pain. RESULTS Adolescents with PFPS, compared to controls, had significantly lower PPTs (26%-37% [100-178 kPa]) at each of the 4 sites around the knee, suggesting localized hyperalgesia. On the tibialis anterior, adolescents with PFPS had a 33% (159 kPa) lower PPT (distal hyperalgesia) compared with controls. CONCLUSION These findings suggest that adolescent females with PFPS have localized and distal hyperalgesia. These findings may have implications for treating PFPS, as both peripheral and central mechanisms may be driving the pain. Registered at clinicaltrials.gov (NCT01438762).

High prevalence of daily and multi-site pain – a cross-sectional population-based study among 3000 Danish adolescents

BackgroundDaily pain and multi-site pain are both associated with reduction in work ability and health-related quality of life (HRQoL) among adults. However, no population-based studies have yet investigated the prevalence of daily and multi-site pain among adolescents and how these are associated with respondent characteristics. The purpose of this study was to investigate the prevalence of self-reported daily and multi-site pain among adolescents aged 12–19 years and associations of almost daily pain and multi-site pain with respondent characteristics (sex, age, body mass index, HRQoL and sports participation).MethodsA population-based cross-sectional study was conducted among 4,007 adolescents aged 12–19 years in Denmark. Adolescents answered an online questionnaire during physical education lessons. The questionnaire contained a mannequin divided into 12 regions on which the respondents indicated their current pain sites and pain frequency (rarely, monthly, weekly, more than once per week, almost daily pain), characteristics, sports participation and HRQoL measured by the EuroQoL 5D. Multivariate regression was used to calculate the odds ratio for the association between almost daily pain, multi-site pain and respondent characteristics.ResultsThe response rate was 73.7%. A total of 2,953 adolescents (62% females) answered the questionnaire. 33.3% reported multi-site pain (pain in >1 region) while 19.8% reported almost daily pain. 61% reported current pain in at least one region with knee and back pain being the most common sites. Female sex (OR: 1.35-1.44) and a high level of sports participation (OR: 1.51-2.09) were associated with increased odds of having almost daily pain and multi-site pain. Better EQ-5D score was associated with decreased odds of having almost daily pain or multi-site pain (OR: 0.92-0.94).ConclusionIn this population-based cohort of school-attending Danish adolescents, nearly two out of three reported current pain and, on average, one out of three reported pain in more than one body region. Female sex, and high level of sports participation were associated with increased odds of having almost daily pain and multi-site pain. The study highlights an important health issue that calls for investigations to improve our understanding of adolescent pain and our capacity to prevent and treat this condition.

2016 Patellofemoral pain consensus statement from the 4th International Patellofemoral Pain Research Retreat, Manchester. Part 2: recommended physical interventions (exercise, taping, bracing, foot orthoses and combined interventions)

Patellofemoral pain affects physically active and sedentary individuals, accounting for 11–17% of knee pain presentations to general practice1 ,2 and 25–40% of all knee problems seen in a sports injury clinic.3 ,4 Patellofemoral pain is characterised by anterior knee pain associated with activities such as squatting, rising from sitting and stair ambulation. While traditionally viewed as self-limiting, increasing research data suggest that patellofemoral pain is often recalcitrant and can persist for many years,5–8 and may cause a decline in sports participation.8 ,9 Despite its high prevalence among active individuals9–12 and frequent presentations for treatment, there are few published guidelines to help clinicians choose the appropriate evidence-based treatment for patellofemoral pain. The most recent and relevant paper from Barton and colleagues13 combined systematic review findings with qualitative interviews from expert clinicians to provide a clinically relevant synthesis, covering the literature up to September 2013. At the International Patellofemoral Pain Research Retreat in Manchester 2015, we held a consensus meeting to update the current evidence base and produce consensus-based recommendations regarding treatment for patellofemoral pain. All retreat registrants were active researchers in patellofemoral pain and presented their research findings. Many of the world leading researchers (eg, 8 out of the top 10 researchers with the highest number of publications, when the term ‘patellofemoral pain’ was searched in Scopus, February 2016) were in attendance and contributed to the consensus meeting. The consensus meeting during the retreat resulted in recommendations, based on evidence published between January 2010 and June 2015. These recommendations should be combined with information gathered from individual patients, regarding their preferences, experiences, presentation and values, along with the values, expertise and skills of individual practitioners to create a patient-centred treatment approach. ### Literature review CJB searched EMBASE, MEDLINE, CINAHL and Current Contents for systematic reviews …

Exercise during school hours when added to patient education improves outcome for 2 years in adolescent patellofemoral pain: a cluster randomised trial

Background Patellofemoral pain (PFP) is common among adolescents and associated with long-lasting pain and disability. Patient education and exercise therapy are commonly used treatments in primary and secondary care but the effect of these treatments in adolescents is unknown. We aimed to determine the effect of exercise therapy as an add-on therapy to patient education compared with education alone. Methods 121 adolescents from 15–19 years of age were cluster randomised to patient education or patient education combined with exercise therapy. Patient education covered self-management of pain and information on PFP. Exercise therapy consisted of supervised exercises on school premises (3/week for 3 months) and instructions on home-based exercises. Adherence to exercises was assessed as attendance and weekly text messages. Primary outcome measure was self-reported recovery (seven-point Likert scale) at 12 months with additional follow-ups at 3, 6 and 24 months. Results Adolescents randomised to patient education and exercise therapy were more likely to have recovered at 12 months (OR, 1.73, 95% CI 1.02 to 2.93, number needed to treat (NNT) of 11). Similar results were observed at 3 and 6 months (OR 1.88 and 1.43) while the effect was further increased at 24 months (OR of 2.52, NNT of 5). A higher total number of weekly exercise sessions increased the odds of recovery. Conclusions In adolescent PFP, the addition of exercise therapy for 3 months was more effective than patient education alone. The effect was apparent at 3 months and increased up to 2 years. Adherence to exercises was important and improved the odds of recovery. Trial registration number clinicaltrials.gov reference: NCT01438762.

Determination of normal values for navicular drop during walking: a new model correcting for foot length and gender

BackgroundThe navicular drop test is a measure to evaluate the function of the medial longitudinal arch, which is important for examination of patients with overuse injuries. Conflicting results have been found with regard to differences in navicular drop between healthy and injured participants. Normal values have not yet been established as foot length, age, gender, and Body Mass Index (BMI) may influence the navicular drop. The purpose of the study was to investigate the influence of foot length, age, gender, and BMI on the navicular drop during walking.MethodsNavicular drop was measured with a novel technique (Video Sequence Analysis, VSA) using 2D video. Flat reflective markers were placed on the medial side of the calcaneus, the navicular tuberosity, and the head of the first metatarsal bone. The navicular drop was calculated as the perpendicular distance between the marker on the navicular tuberosity and the line between the markers on calcaneus and first metatarsal head. The distance between the floor and the line in standing position between the markers on calcaneus and first metatarsal were added afterwards.Results280 randomly selected participants without any foot problems were analysed during treadmill walking (144 men, 136 women). Foot length had a significant influence on the navicular drop in both men (p < 0.001) and women (p = 0.015), whereas no significant effect was found of age (p = 0.27) or BMI (p = 0.88). Per 10 mm increase in foot length, the navicular drop increased by 0.40 mm for males and 0.31 mm for females. Linear models were created to calculate the navicular drop relative to foot length.ConclusionThe study demonstrated that the dynamic navicular drop is influenced by foot length and gender. Lack of adjustment for these factors may explain, at least to some extent, the disagreement between previous studies on navicular drop. Future studies should account for differences in these parameters.

Time-of-day influences postural balance in older adults

BACKGROUND Postural balance assessments are performed in both clinical and basic research settings on a daily basis. During a 24-h time span our physiology and physical performance undergo radical changes as we are influenced by the circadian rhythm. The time-of-day interaction on postural balance is unknown in older adults. The aim of this study was to investigate the time-of-day effect on postural balance in older adults. METHODS Center of pressure (CoP) excursion was measured (100 Hz) by force plate analysis in 34 older adults during 30 s of narrow quiet bilateral stance. Measurements were performed around 9a.m., 12.30 p.m. and 4 p.m. on the same day. Postural balance was quantified by velocity-moment, confidence ellipse area, total sway area and total sway length. RESULTS An overall significant time-of-day (between 9 a.m. and 4 p.m.) effect was observed for velocity-moment (mm(2)/s) 57 ± 27-65 ± 29 (p = 0.001), confidence ellipse area (mm(2)) 36 ± 16-44 ± 19 (p < 0.001), total sway area (mm(2)) 548 ± 263-627 ± 285 (p = 0.001) and total sway length (mm) 373 ± 120-379 ± 113 (p = 0.037). The variation of postural balance was mostly pronounced from midday (12.30 p.m.) toward the afternoon (4 p.m.) in all sway parameters. Specifically between 12.30 p.m. and 4 p.m. confidence ellipse area increased by 18.5%, total sway area by 17.1%, velocity-moment by 15.8% and total sway length by 4.6%. No differences were observed between 9 a.m. and 12.30 p.m. in any of the sway parameters. CONCLUSIONS This study demonstrates that time-of-day influences postural balance in older adults. These findings have important scientific and clinical relevance, as they imply that time-of-day should be a controlled factor when assessing postural balance in older adults.

Is Knee Pain During Adolescence a Self-limiting Condition? Prognosis of Patellofemoral Pain and Other Types of Knee Pain

Background: The prevalence of adolescent knee pain is 33%, and patellofemoral pain (PFP) is the most common diagnosis with a nontraumatic onset. The 2-year prognosis of adolescent PFP compared with other types of knee pain is unknown. Purpose: To investigate the 2-year prognosis of knee pain among adolescents with and without a diagnosis of PFP. Study Design: Cohort study; Level of evidence, 2. Methods: In 2011, a cohort of 2200 adolescents aged 15 to 19 years answered an online questionnaire on musculoskeletal pain. Of these, 504 reported knee pain, and 153 of these were clinically diagnosed with PFP. After 2 years, the 504 adolescents, as well as 252 randomly selected adolescents who did not report knee pain in 2011, were contacted again. Primary outcome at follow-up was the proportion of adolescents with knee pain during the last week prior to follow-up. Results: Overall, 55.9% (95% CI, 50.8%-60.9%) of those reporting knee pain at baseline also reported pain 2 years later. Adolescents diagnosed with PFP had a 1.26 (95% CI, 1.05-1.50) higher relative risk (RR) of knee pain at follow-up compared with other types of knee pain. Adolescents with PFP were significantly more likely to reduce or stop sports participation compared with adolescents with other types of knee pain. Of those without knee pain at baseline, 12.8% (95% CI, 8.4%-17.2%) reported knee pain at follow-up in 2013. Adolescents with knee pain at baseline had a 4.51 (95% CI, 3.15-6.45) higher RR of knee pain at follow-up compared with adolescents without knee pain at baseline. Conclusion: Knee pain during adolescence, and PFP in particular, is in most cases present after 2 years and thus may not be self-limiting. A greater focus on early detection and prevention of knee pain during adolescence is needed.