Lower Extremity Kinetics and Kinematics in Runners with Patellofemoral Pain: A Retrospective Case–Control Study Using Musculoskeletal Simulation

Patellofemoral pain (PFP) is a common atraumatic knee pathology in runners, with a complex multifactorial aetiology influenced by sex differences. This retrospective case–control study therefore aimed to evaluate lower limb kinetics and kinematics in symptomatic and control male and female runners using musculoskeletal simulation. Lower extremity biomechanics were assessed in 40 runners with PFP (15 females and 25 males) and 40 controls (15 females and 25 males), whilst running at a self-selected velocity. Lower extremity biomechanics were explored using a musculoskeletal simulation approach. Four intergroup comparisons—(1) overall PFP vs. control; (2) male PFP vs. male control; (3) female PFP vs. female control; and (4) male PFP vs. female PFP—were undertaken using linear mixed models. The overall (stress per mile: PFP = 1047.49 and control = 812.93) and female (peak stress: PFP = 13.07 KPa/BW and control = 10.82 KPa/BW) comparisons showed increased patellofemoral joint stress indices in PFP runners. A significantly lower strike index was also shown in PFP runners in the overall (PFP = 17.75% and control = 33.57%) and female analyses (PFP = 15.49% and control = 40.20%), revealing a midfoot strike in control, and a rearfoot pattern in PFP runners. Peak rearfoot eversion and contralateral pelvic drop range of motion (ROM) were shown to be greater in PFP runners in the overall (eversion: PFP = −8.15° and control = −15.09°/pelvic drop ROM: PFP = 3.64° and control = 1.88°), male (eversion: PFP = −8.05° and control = −14.69°/pelvic drop ROM: PFP = 3.16° and control = 1.77°) and female (eversion: PFP = 8.28° and control = −15.75°/pelvic drop ROM: PFP = 3.64° and control = 1.88°) PFP runners, whilst female PFP runners (11.30°) exhibited a significantly larger peak hip adduction compared to PFP males (7.62°). The findings from this investigation highlight biomechanical differences between control and PFP runners, as well as demonstrating distinctions in PFP presentation for many parameters between sexes, highlighting potential risk factors for PFP that may be addressed through focused intervention modalities, and also the need, where appropriate, for sex-specific targeted treatment approaches.

Knee Pathology before and after SARS-CoV-2 Pandemic: An Analysis of 1139 Patients

Background: The SARS-CoV-2 pandemic drastically changed daily life activities and medical practice, leading to a reorganization of healthcare activities. People spent two months in home-isolation, changing their daily habits and undertaking a more sedentary lifestyle. Change in lifestyle is related to important consequences in knee pathologies. The aim of this study was to evaluate the outpatient activity for knee pathologies before and after lockdown in terms of incidence, severity, diagnosis, and treatment. Methods: Medical records of patients with knee pathology in outpatient follow-up at IRCCS Istituto Ortopedico Galeazzi in Milan (Italy) were analyzed in the time frame 4 May–4 September 2020 and compared with patients examined between 4 May and 4 September 2019. Results: A significant increase of knee diagnoses associated to patellofemoral disorders in 2020 was found (p = 0.004). In addition, physiotherapy was significantly more prescribed in 2020 than in 2019 (p = 0.012). Conclusions: The SARS-CoV-2 pandemic lockdown did not drastically change knee pathology, but it may have had an impact on it, highlighting a summary worsening of patellofemoral disorders associated with other knee diagnoses. Further studies are required to validate this result.

Muscle Synergy of Lower Limb Motion in Subjects with and without Knee Pathology

Surface electromyography (sEMG) has great potential in investigating the neuromuscular mechanism for knee pathology. However, due to the complex nature of neural control in lower limb motions and the divergences in subjects’ health and habits, it is difficult to directly use the raw sEMG signals to establish a robust sEMG analysis system. To solve this, muscle synergy analysis based on non-negative matrix factorization (NMF) of sEMG is carried out in this manuscript. The similarities of muscle synergy of subjects with and without knee pathology performing three different lower limb motions are calculated. Based on that, we have designed a classification method for motion recognition and knee pathology diagnosis. First, raw sEMG segments are preprocessed and then decomposed to muscle synergy matrices by NMF. Then, a two-stage feature selection method is executed to reduce the dimension of feature sets extracted from aforementioned matrices. Finally, the random forest classifier is adopted to identify motions or diagnose knee pathology. The study was conducted on an open dataset of 11 healthy subjects and 11 patients. Results show that the NMF-based sEMG classifier can achieve good performance in lower limb motion recognition, and is also an attractive solution for clinical application of knee pathology diagnosis.

Osteoarthritis of the knee joint. Etiology, treatment, rehabilitation (analytical review of the literature)

According to epidemiological studies, osteoarthritis accounts for 10–12 % of all cases of musculoskeletal diseases. In the general structure of knee pathology, degenerative diseases make up 57.8 %. The urgency of the problems of gonarthrosis is due to not only its widespread prevalence, but also the high risk of developing knee dysfunction, accompanied by a significant reduction in the quality of life of patients and often leading to partial or permanent disability of patients. Gonarthrosis has significant gender features. Women account for about 70 % of the number of patients, while men had this disease almost 2 times less often, but other data indicate that the incidence of gonarthrosis in men under 60 years of age is higher, and in women it begins to increase after 65 years. Knee replacement is a leading method in the treatment of knee osteoarthritis stages III–IV. The tendency towards an increase in the total number of surgeries leads to an increase in the frequency of complications and unsatisfactory results: according to some authors, from 3.3 to 13.2 % of patients complain of knee replacement outcomes. Studies of long-term complaints after arthroplasty have shown that in addition to pain reduction, some patients had an increase in varus angle when bending the knee while walking but they didn’t mark an improvement in gait parameters compared to preoperative examination. After unilateral total knee arthroplasty, the load patterns of the frontal plane in the operated knee remain pathological in the long run. After knee arthroplasty, there is muscle weakness, and studies have shown changes in all muscles of the lower extremity. Weakening of some muscles led to compensatory strengthening of others. Studies of the effect of preoperative rehabilitation on the outcome of knee arthroplasty have shown its low efficiency. Many studies have studied motor activity of patients after total knee arthroplasty in recent years. Not only gait features, but also movements of the pelvis, trunk and upper extremities are studied. Modern methods of diagnosing spatial oscillations of the body when walking have shown that disorders of body movements — excessive hand movements, pelvic loosening, asymmetrical flexion of the knee joints, etc., after arthroplasty are preserved in patients and restore slowly, and some disorders remain forever. Conclusions. Knee arthroplasty relieves pain, improves quality of life, but according to many authors, patients complain of incomplete restoration of the functionality of the prosthetic limb. According to the researchers, the main cause for incomplete reco-very of gait parameters is the difference in the frontal angles of the knee joint flexion and the difference in the length of the steps. Special training exercises can reduce the asymmetry of the steps, but it is difficult to completely restore the symmetry of the steps within 2 years. Studies of the effect of preoperative rehabilitation on the outcome of knee arthroplasty have shown its low effectiveness.

Design and rationale of the ATtune Knee Outcome Study (ATKOS): multicenter prospective evaluation of a novel uncemented rotating platform knee system

Background Total Knee Arthroplasty (TKA) remains the gold standard for treatment of debilitating symptoms of knee osteoarthritis (OA). Even though providing satisfactory results for the majority of patients, some studies report dissatisfaction after TKA to be as high as 20%. Among other things, pain catastrophising and self-efficacy are thought to compromise results of TKA. Implant manufacturers keep improving upon their designs in an attempt to improve functional outcomes. One of these novel knee systems is the Attune. To our knowledge, there are no clinical follow-up studies reporting results of the uncemented version. The main objective of this multicentre prospective observational study is to evaluate revision rate, complications, radiographic outcomes (i.e. alignment and radiolucent lines) and patient reported outcomes of the uncemented Attune mobile bearing TKA. Secondary objectives are (1) to assess physical function, return to sport and return to work after TKA and (2) to evaluate the long-term effect of preoperative psychological factors on satisfaction after TKA. Methods All patients presenting in the participating centres with knee pathology warranting joint replacement therapy will be considered for inclusion, an absolute indication for cemented fixation is the only exclusion criterium. Evaluation of clinical and radiographic performance (e.g. radiolucent lines) is done at 6 weeks, 6 months, 1 year, 5 years and 10 years after surgery using validated patient reported outcome measures. Cumulative revision rates are calculated after 5 and 10 years using Kaplan–Meier methods. Physical function is assessed with performance based measurements before and 1 year after surgery. Return to sports is assessed using the Tegner and University of California Los Angeles (UCLA) activity rating scale before and 1 year after surgery. Return to work is evaluated by inviting patients of working age to complete a short questionnaire 1 year after surgery. Psychologic factors are assessed using questionnaires for pain catastrophising, pain self-efficacy and mental health before, 5 years and 10 years after surgery. Preoperative psychologic scores are correlated to functional outcomes. Discussion The current study aims to report the clinical performance of a novel implant and can help provide insight in factors that play a role in satisfaction after TKA. Trial registration ClinicalTrials.gov identifier: NCT04247672 (January 30, 2020)

RELIABILITY OF NOVEL ULTRASOUND MEASUREMENT FOR DETERMINING PATELLA POSITION

Background: Patellar dislocations are common among youth athletes. A detailed understanding of patellofemoral anatomy is critical to determine patient prognosis and guide treatment and decision making. Recent literature suggests that measures of patella position relative to the trochlear groove may help identify individuals at risk of repetitive dislocations. While these measures were described using MRI, it is plausible that ultrasound imaging can be utilized to provide similar information in a more cost-effective and time-efficient manner. Purpose: To determine intra and inter-rater reliability of two newly described ultrasound-based measures of patella positioning within two novice examiners. Methods: Subjects were seated with the limb supported in full knee extension and neutral rotation. (Figure 1a) The examiners independently gathered all images and were blinded to each other’s measures for the duration of the study. The transducer was positioned transversely, on the anterior aspect of the knee such that the lateral trochlear ridge, center of trochlear groove, and proximal portion of the patellar tendon were all visible in cross-section. (Figure 1b) Two linear measures were obtained, representing the distance from midpoint of the patellar tendon to a) the center of trochlear groove (MPT-CTG) and b) the lateral trochlear ridge (MPT-LTR). Reliability was assessed using intraclass correlation coefficients (ICC). The average of two measures were used for data analysis. There was a minimum of 1 week between assessments for those subjects with repeated testing. Results: A total of 11 subjects (mean age 15.3) without history of knee pathology were included. There were no significant differences (p>0.05) in either measurement between limbs with MPT-CTG and MPT-LTR values (mean±sd) as follows: MPT-CTG right 8.4mm ± 3.0, left 8.4mm ± 3.3; MPT-LTR right 12.2mm ± 2.7, left 11.6mm ± 2.3. For reliability analysis, each knee served as a discrete variable, yielding a total of 22 data points for evaluation. Inter-rater reliability (n=22) was moderate to good for both measures, with ICC values of 0.724 and 0.814 for MPT-CTG and MPT-LTR, respectively. Intra-rater reliability (n=10) was good to excellent with ICC values of 0.913 and 0.794 for MPT-CTG and MPT-LTR, respectively. (Table 1) Conclusions: This new measure of patella positioning demonstrated moderate to excellent reliability and may be a practical, cost-effective alternative to MRI. While it is encouraging that the subjects in this sample demonstrated no side-to-side differences in either measure, future research should focus on establishing criterion validity and reliability amongst individuals with patellar instability. [Figure: see text][Table: see text]

LIMITED INTER-RATER RELIABILITY IN ANTEROLATERAL LIGAMENT DETECTION IN PEDIATRIC KNEE MRIS

Background: Despite the rapidly expanding anterolateral ligament (ALL) literature base, little has focused on the reliability of its detection on MRI. This is especially important in the pediatric population where the scarcity of pediatric cadaveric specimens hinders the accurate estimation of its prevalence. Purpose: The purpose of this study was to assess the visibility of ALL on common MRI pulse sequences and to calculate the inter-rater reliability among multiple expert readers in a cohort of normal pediatric knee MRIs. Methods: A series of 3T pediatric knee MRIs obtained from 8/2018-4/2019 were reviewed to identify patients without significant knee pathology. Knee laterality, age, gender, and regional physeal status were also recorded. One orthopedic surgeon, 1 pediatric musculoskeletal (MSK) radiologist, and 1 adult MSK radiologist, independently reviewed each MRI pulse sequence (T1-weighted, PD-weighted, and PD-weighted fat-suppressed images) separately, to determine the presence or absence of the 3 parts of the ALL (femoral, tibial, and meniscal proper). Inter-rater reliability was calculated using Fleiss’ Kappa (K). Results: Inclusion criteria were met for 75 patient knees with a mean age of 12.7±3.42y (3-19) and a greater proportion of females (57.3%). The distribution of regional physeal status was: Open-48.0%, Closing-29.3%, and Closed-22.7%. Inter-rater reliability was slight to fair (K: 0.141-0.340) for visualizing any specific ALL component on a unique MRI sequence (Table 1). For visualizing a specific attachment on any MRI sequence, there was slight to moderate agreement (K: 0.018-0.411). Visualizing any ALL attachment on any MRI sequence also yielded slight agreement (K: 0.190). Inter-rater reliability between specialities (i.e. Ortho vs. MSK Radiology) did not differ substantially from group findings. No single study sequence demonstrated enhanced reliability for all ALL components. Conclusion: The reliability of ALL detection on MRI across multiple clinicians was slight to moderate for all components in this cohort of normal 3T pediatric knee MRIs. No single sequence was consistently better for ALL detection agreement. This is in contrast with previous work showing substantial agreement among raters and describing PD-weighted imaging as preferable for viewing the ALL. Experience in musculoskeletal imaging did not confer improved agreement. Establishing diagnostic reliability should be a prerequisite for use of an imaging finding in the research or clinical setting. Existing literature drawing conclusions from ALL findings on MRI may need to be interpreted with caution if reliability testing is not described. [Table: see text]

KNEE RADIOGRAPHS DEMONSTRATE SMALL BUT STATISTICALLY SIGNIFICANT INCREASE IN POSTERIOR TIBIAL SLOPE IN PATIENTS WITH OSGOOD-SCHLATTER DISEASE

Background: Previous research has demonstrated an association between Osgood-Schlatter disease (OSD) and increased posterior tibial slope (PTS) in a small subset of patients with MRI and clinical exam consistent with OSD. Hypothesis/Purpose: To determine if children diagnosed clinically with OSD have an increased PTS on routine radiographs compared to controls. Methods: Patients 10-18 years old with the clinical diagnosis of OSD and a true lateral knee X-ray between 2016 and 2019 were eligible for the OSD group. Subjects were excluded if they had other significant knee pathology (Figure 1). The same number of controls were selected from patients in the same age and date range with history of anterior knee pain and a true lateral knee X-ray but no evidence of OSD or other significant pathology on clinical exam or X-ray. Demographic data and HSS Functional Activity Brief Scale (HSS Pedi-FABS) scores were collected for each subject. PTS measurements were performed on true lateral X-Rays by three blinded investigators. Independent samples t-test and chi-squared test were used to compare variable means and frequency between OSD and control knees. Logistic regression analysis was used to investigate the effects of OSD, age, sex, height, weight, and HSS Pedi-FABS score on PTS (≥12º versus <12º). Results: 258 total knees (129 with OSD and 129 controls) were included. Mean age was 12.9 ± 1.8 years and 53% knees were male. There were no differences in age, sex, BMI, or laterality of knees between groups (Table 1). Mean PTS was significantly higher in the OSD group (11.6º ± 2.9º) compared to the control group (9.3º ± 2.7º, p<0.0001). In the OSD group, 46% of knees had a PTS ≥12º and in the control group, 19% knees had a PTS >12º (p<0.001). Logistic regression analysis showed that patients with OSD had 3.63 greater odds (95% CI 1.78-7.40) of having PTS ≥12º compared to patients without OSD, when controlling for age, sex, height, weight, and HSS Pedi-FABS score (Table 2). Conclusion: This study further supports an association between OSD and a mild increase in PTS. Patients with OSD had 3.6 greater odds of having PTS≥12º. The clinical implications of this finding have not yet been elucidated. We speculate that in patients with OSD, stresses (or force) exerted from the quadriceps muscle group through the patellar tendon loads the anterior portion of the tibia tubercle disproportionately to the posterior segment and causes asymmetric growth and an increased PTS. Tables/ Figures [Table: see text][Table: see text][Figure: see text]

Early outcomes of novel Temren atherectomy device combined with drug-coated balloon angioplasty for treatment of femoropopliteal lesions

Objectives In this study, perioperative properties and early outcomes of patients who underwent combined Temren rotational atherectomy (RA) and drug-coated balloon (DCB) angioplasty treatment for complex femoropopliteal lesions in a single center were reported. Methods Between June 2019 and February 2020, 40 patients who underwent combined Temren RA and DCB treatment due to critical lower limb ischemia or claudication-limiting daily living activities were retrospectively evaluated. Results The mean age of patients was 73.2 ± 7.8 years and the majority of the patients were male (65%). Of the patients, 17 had critical limb ischemia and 23 had lifestyle-limiting claudication. Pathologies were total occlusion in 33 limbs and critical stenosis in seven limbs. Nine patients previously underwent endovascular intervention or surgery. The mean total occlusion length was 140.9 ± 100.9 (range, 20–360) mm in patients with chronic total occlusion. There was an additional iliac artery pathology in 5 and below the knee pathology in 8 patients. Rotational atherectomy was possible in all cases. Flow-limiting dissection was seen in six patients (15%). Provisional stent was performed to these patients. Following Temren RA, all patients underwent DCB. Adequate vascular lumen (less than 30% stenosis) was provided in all patients and the symptoms regressed. No distal embolization was encountered. Access site complications (17.5%) were small hematoma in four patients, ecchymosis in two patients, and pseudoaneurysm of the femoral artery in one patient. The mean follow-up was 13.55 ± 4.2 (range, 1–18) months. Re-occlusion was seen in three patients (7.5%) ( n = 2 at 2 months and n = 1 at 4 months). Of these patients, two had required open revascularization via femoropopliteal bypass graft with common, superficial femoral, and popliteal artery endarterectomy and one had required femoro-posterior tibial artery bypass. Four minor toe amputations (10%) were performed to reach complete wound healing in the critical limb ischemia patients. A below-knee amputation was performed in a 94-year-old patient with long segment stenosis at the end of a 1-month follow-up period. There was no mortality after follow-ups. The Kaplan–Meier estimator estimated the rate of freedom from target lesion revascularization (TLR) which was 92.3%. The decrease in the Rutherford levels after the procedure was found to be statistically significant in 36 patients ( p < 0.001). The increase in the ankle–brachial index after the procedure was found to be statistically significant in 36 patients ( p < 0.001). Conclusions Combined use of Temren RA with adjunctive DCB is safe and effective method with high rates of primary patency and freedom from TLR and low rates of complication in the treatment of femoropopliteal lesions.

Longitudinal study of medical downgrades in the Royal Air Force

IntroductionAs the focus of the Royal Air Force (RAF) shifts from sustained to contingency operations and the number of personnel is reduced, the burden of retained, medically downgraded personnel may affect operational readiness. The main aims were: to define the prevalence of morbidity leading to permanent medical downgrading; to determine at risk populations and identify areas for improvement.MethodDatabase of personnel referred to the RAF Medical Board was analysed from January 2012 to October 2013 and January 2017 to December 2019. Patients were excluded if they did not require a formal medical board; incomplete and duplicate entries were also excluded. The primary reason for medical downgrade was categorised with an ICD-10 code. Further subanalysis compared musculoskeletal disease with age, individual trade groups and anatomic region.Results2% of RAF service personnel were permanently downgraded annually. Musculoskeletal disease was the leading cause for permanent downgrade across both periods: 58% and 49%. Female personnel were at a greater risk of musculoskeletal downgrade compared with males. Spinal and knee pathology were the leading cause for downgrading among ‘high risk’ personnel. Personnel downgraded due to musculoskeletal pathology were often retained in a limited role with 10% and 5% retained as medically fully deployable. 14% and 12% of personnel downgraded due to musculoskeletal pathology were medically discharged.ConclusionMusculoskeletal disease was the leading cause for permanent medical downgrades in the RAF. A greater proportion of downgraded personnel with musculoskeletal conditions were retained in service with medical limitations rather than medically discharged.