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The anterolateral thigh (ALT) flap is widely used in the reconstruction of a variety of soft tissue defects. Descriptions of patients with severe obesity in the literature are scarce. We report a case where a reverse pedicled fasciocutaneous ALT flap was successfully used for resurfacing of a knee defect measuring 12×6 cm in a patient with a body mass index (BMI) of 47.3. The flap was supercharged to the greater saphenous vein to optimise flap survival. Reconstruction of the soft tissue of the knee was achieved as planned. There were no flap or donor site complications.

Background Hop performance evaluation in children after anterior cruciate ligament (ACL) reconstruction may benefit from comparison to healthy controls. Thus, the purpose was to investigate the hop performance in children one year after ACL reconstruction with a comparison to healthy controls. Methods Hop performance data from children with ACL reconstruction one year post-surgery and healthy children were compared. Four one-legged hop test data were analyzed: 1) single hop (SH), 2) 6 m timed hop (6 m-timed), 3) triple hop (TH), and 4) cross-over hop (COH). Outcomes were the best result (longest/fastest hop) from each leg and limb asymmetry. Differences in hop performance between-limbs (operated versus non-operated) and between-groups were estimated. Results 98 children with ACL reconstruction and 290 healthy children were included. Few statistically significant group differences were observed. Girls with ACL reconstruction outperformed healthy controls in two tests on the operated leg SH, COH) and in three tests on the non-operated leg (SH, TH, COH). However, the girls performed 4–5% worse on the operated leg when compared to the non-operated leg in all hop tests. No statistically significant between-group differences in the limb asymmetry were found. Conclusion The hop performance in children with ACL reconstruction one year post-surgery was largely comparable to the level of healthy controls. Despite this, we cannot exclude that neuromuscular deficits exist among the children with ACL reconstruction. The inclusion of a healthy control group for evaluating hop performance evoked complex findings regarding the ACL reconstructed girls. Thus, they may represent a selected group.

Background: Anterior cruciate ligament (ACL) tear is a common medical condition that entails a stretch or sprain of the ACL, which is present in the knee joint. The incidence of ACL injury in the Kingdom of Saudi Arabia is estimated to be 31.4%. Prevention training programs (PTPs) can be used to reduce ACL injuries sustained during physical activity, as they primarily focus on improving strength, balance, and lower limb biomechanics and reducing landing impact. This study aimed to assess Saudi athletes’ awareness of ACL injury PTPs. Methods: A cross-sectional survey in the form of a self-administered questionnaire in the Arabic language was carried out from 22 December 2022 to 7 March 2023 and included 1169 Saudi athletes. Statistical analyses were performed on the collected data using frequency and percentages. Binary logistic regression was used for the adjusted analysis and determining associations between athletes playing high- and low-risk sports. Results: Overall, 52% of participants were female athletes, and 48% were male athletes. The western region of the country had the highest response rate (28.9%). The most common sport played was football at 36.6%. Most participants (70.97%) reported that their information on ACL injury was taken by their coaches. When assessing whether participants were familiar with the concept of an ACL injury PTP, the majority of the participants answered no, representing 971 (662 high-risk, 309 low-risk), compared to those who answered yes, representing only 198 (167 high-risk, 31 low-risk), with a statistically significant difference (adjusted OR: 2.106; 95% confidence interval: 1.544–2.873; p-value < 0.001). Conclusion: In general, the level of awareness of ACL injury PTPs among Saudi athletes was poor.

Aims: To determine whether there was a relation between socioeconomic status (SES) and patient symptoms before and one year after total knee arthroplasty (TKA), and/or total hip arthroplasty (THA) and whether a change in symptoms was clinically relevant. Patients and methods: A secondary analysis of a prospective cohort study was conducted on SES and osteoarthritis symptoms of patients (≥45 years old) who received a primary TKA or THA between 2016 and 2018. The relation between SES and respectively pre- and postoperative and change in patient-reported outcome measures including the Oxford Knee Score (OKS), Oxford Hip Score (OHS), Western Ontario and McMaster Universities Arthritis Index (WOMAC), the visual analog scale (VAS) for pain and the EuroQol 5-Dimensions (EQ-5D) were assessed using linear mixed-effects regression models adjusted for age and sex. The following potential confounding variables were considered in the regression models: body mass index (BMI), American Society of Anesthesiologists (ASA)- classification, Charnley-classification, smoking status, and alcohol consumption. Results: Patients with lower SES were mostly female, had a higher BMI and ASA-classification compared to patients with a higher SES. Patients with lower SES reported lower OKS (β = 3.78, P = 0.001). Patients undergoing THA reported lower scores for the OHS (β = 4.78, P = 0.001), WOMAC (β = 11.7, P = 0.001), and less pain (VAS, β = −0.91, P = 0.001). No statistically significant differences between SES groups were seen in the quality of life and health status as measured with the EQ-5D. Conclusion: Patients with a lower socioeconomic status reported worse symptoms and showed less clinically relevant improvement at one-year follow-up.

Purpose Genicular artery embolization (GAE) is a new treatment option for symptomatic knee osteoarthritis. Genicular arterial anatomy is complex with limited published reports. This study describes the genicular artery anatomy utilizing intraprocedural cone-beam computed tomography (CBCT) during GAE. Materials and Methods This retrospective single-center study was approved by the institutional review board. All patients who underwent GAE between May 2018 and April 2022 were reviewed. Patients with a technically adequate CBCT were included in the analysis. CBCTs were analyzed to determine the presence, course, and branching patterns of the genicular arteries. Results A total of 222 patients underwent GAE and 205 (92%) were included for analysis. The descending genicular artery was present in 197 (96%) CBCTs with two branches in 152 (77%). The superior medial genicular artery (SMGA) was present in 186 (91%), superior lateral genicular artery (SLGA) in 203 (99%), inferior medial genicular artery (IMGA) in 195 (95%), inferior lateral genicular artery (ILGA) in 196 (95%), and median genicular artery (MGA) in 200 (97%). Four unique branching patterns were identified: common origin of SLGA and MGA (115, 56%), unique origins (45, 22%), trifurcation of SLGA, SMGA, and MGA (32, 15.5%), and common origin of SMGA and MGA (12, 6%). The recurrent ascending tibial was identified in 156 (76%) CBCTs and superior patellar artery in 175 (85%) CBCTs. Conclusion Genicular artery anatomy is complex with numerous common variants. CBCT is a powerful adjunct in GAE to rapidly identify target vessels for embolization and potentially decrease the risk of nontarget embolization.

Charcot’s joint is a type of neuro-arthropathy, where asymmetrical damage of the involved joint happens haphazardly, without following any described pattern. We present a rare case of Charcot’s joint involving the knee joint in an adult male following spina bifida. His knee joint was successfully fused after two surgeries. Later, he sustained a fracture through the arthrodesis after a fall, which we managed surgically. The fracture through the knee arthrodesis was managed surgically by an open reduction and internal fixation, using a 14-hole broad low contact dynamic compression locking plate with bone grafting. Union was achieved at the knee arthrodesis site in 6 months. Fracture through a fused knee requires surgical management. Re-arthrodesis was done using a stable fixation. Postoperative rehabilitation should include protected weight bearing with braces and splints until a sound bony union is achieved.

To evaluate the efficacy of a 2-week home-based blood flow restriction (BFR) prehabiliation program on quadriceps strength and patient-reported outcomes prior to anterior cruciate ligament (ACL) reconstruction.Patients presenting with an ACL tear were randomized into two groups, BFR and control, at their initial clinic visit. Quadriceps strength was measured using a handheld dynamometer in order to calculate peak force, average force, and time to peak force during seated leg extension at the initial clinic visit and repeated on the day of surgery. All patients were provided education on standardized exercises to be performed 5 days per week for 2 weeks between the initial clinic visit and date of surgery. The BFR group was instructed to perform these exercises with a pneumatic cuff set to 80% of limb occlusion pressure placed over the proximal thigh. Patient-Reported Outcome Measurement System Physical Function (PROMIS-PF), knee range of motion, and quadriceps circumference were gathered at the initial clinic visit and day of surgery, and patients were monitored for adverse effects.A total 45 patients met inclusion criteria and elected to participate. There were 23 patients randomized to the BFR group and 22 patients randomized into the control group. No significant differences were noted between the BFR and control groups in any demographic characteristics (48% vs 64% male [P = .271] and average age 26.5 ± 12.0 vs 27.0 ± 11.0 [P = .879] in BFR and control, respectively). During the initial clinic visit, there were no significant differences in quadriceps circumference, peak quadriceps force generation, time to peak force, average force, pain, and PROMIS scales (P.05 for all). Following completion of a 2-week home prehabilitation protocol, all patients indeterminant of cohort demonstrated decreased strength loss in the operative leg compared to the nonoperative leg (P.05 for both) However, there were no significant differences in any strength or outcome measures between the BFR and control groups (P.05 for all). There were no complications experienced in either group, and both were compliant with the home-based prehabilitation program.A 2-week standardized prehabilitation protocol preceding ACL reconstruction resulted in a significant improvement in personal quadriceps peak force measurements, both with and without the use of BFR. No difference in quadriceps circumference, strength, or patient reported outcomes were found between the BFR and the control group. The home-based BFR prehabiliation protocol was found to be feasible, accessible, and well tolerated by patients.Level II, randomized controlled trial with small effect size.

Altering running cadence is commonly done to reduce the risk of running-related injury/reinjury. This study examined how altering running cadence affects joint kinetic patterns and stride-to-stride kinetic variability in uninjured female runners. Twenty-four uninjured female recreational runners ran on an instrumented treadmill with their typical running cadence and with a running cadence that was 7.5% higher and 7.5% lower than typical. Ground reaction force and kinematic data were recorded during each condition, and principal component analysis was used to capture the primary sources of variability from the sagittal plane hip, knee, and ankle moment time series. Runners exhibited a reduction in the magnitude of their knee extension moments when they increased their cadence and an increase in their knee extension moments when they lowered their cadence compared with when they ran with their typical cadence. They also exhibited greater stride-to-stride variability in the magnitude of their hip flexion moments and knee extension moments when they deviated from their typical running cadence (ie, running with either a higher or lower cadence). These differences suggest that runners could alter their cadence throughout a run in an attempt to limit overly repetitive localized tissue stresses.

Anterior cruciate ligament (ACL) injuries in children and adolescents are a relevant health and economic burden and their incidence increases at a higher rate than in adults. These injuries compromise the quality of life, affect the development of the knee joint as well as its future functionality, and may lead to early onset of osteoarthritis. Because of their young age, these patients are furthermore at high risk for secondary intraarticular soft tissue damage and re-injury of the ACL. The relatively small number of pediatric ACL injuries in single hospitals, necessitates international multicenter studies to collect meaningful prospective data and long-term outcomes in a young patient population. As a result, there are few high-quality studies on the treatment of pediatric ACL rupture, and the evidence base of current treatment recommendations is insufficient. Thus, the Paediatric Anterior Cruciate Ligament Monitoring Initiative (PAMI) was created in 2013. The registry is designed to collect and analyze data on the diagnosis and treatment of ACL injuries in children and adolescents and to provide a basis for the development of international evidence-based guidelines. Since 2018, patients with a skeletal age of 8-14 years in girls and 8-16 years in boys, respectively, have been recruited for the PAMI registry in various international centers, and the number of recruiting centers as well as the number of patients is increasing constantly. Analysis of the data from the first three years of the project provides epidemiological data and suggests initial trends. It is evident that the project is well established and in international demand. A future challenge is to ensure the long-term durability of PAMI and the dissemination of scientific findings.

Backward walking (BW) has been recommended as a rehabilitation intervention to prevent, manage, or improve diseases. However, previous studies showed that BW significantly increased the first vertical ground reaction force (GRF) during gait, which might lead to higher loading at the knee. Published reports have not examined the effects of BW on medial compartment knee loading. The objective of this study was to investigate the effects of BW on external knee adduction moment (EKAM). Twenty-seven healthy adults participated in the present study. A sixteen-camera three-dimensional VICON gait analysis system, with two force platforms, was used to collect the EKAM, KAAI, and other biomechanical data during BW and forward walking (FW). The first ( P < 0.001 ) and second ( P < 0.001 ) EKAM peaks and KAAI ( P = 0.02 ) were significantly decreased during BW when compared with FW. The BW significantly decreased the lever arm length at the first EKAM peak ( P = 0.02 ) when compared with FW. In conclusion, BW was found to be a useful strategy for reducing the medial compartment knee loading even though the first peak ground reaction force was significantly increased.

Background: Meniscal allograft transplant (MAT) is an effective treatment for relieving symptoms and improving knee function in patients who experience symptomatic unicompartmental knee pain after a previous meniscectomy. However, the literature contains a paucity of studies assessing the survival rate and prognostic factors of soft tissue MAT. Purpose: To report the survivorship of a large, single-center cohort of consecutive patients treated with arthroscopic MAT using soft tissue technique and to investigate variables that could potentially influence failures and outcomes. Study design: Case series; Level of evidence, 4. Methods: Consecutive MAT procedures totaling 364 performed in a single institution between June 2004 and April 2019 were screened and assessed for eligibility. Subjective clinical scores (Lysholm score, Tegner activity scale, and visual analog score) were collected preoperatively and at 2, 5, 7, and 10 years of follow-up. Two survival analyses were performed using Kaplan-Meier curves, with surgical failure (defined as any graft revision) and clinical failure (defined as a Lysholm score Results: A total of 324 consecutive patients were evaluated at a mean follow-up 5.7 ± 3.0 years. Of these, 189 (58%) underwent an associated surgical procedure. A total of 22 patients (6.8%) were considered to have experienced surgical failure, and no predictors of surgical failure were identified based on the relevant variables. When all patients were considered, a significant improvement in all of the patient-reported outcome measures was present between the preoperative assessment and the last follow-up ( P < .001), with no significant decrease over time. Moreover, 70 (21.6%) patients were considered to have experienced clinical failure; the need for concurrent cartilage procedures (odds ratio, 0.16; P = .001) and anterior cruciate ligament (ACL) reconstruction (odds ratio, 0.40; P = .059) were predictors of failure. Finally, a lower survival rate was reported in female patients compared with male patients (49% vs 69%, respectively; P = .007) and in patients who required cartilage surgery ( P = .014). In particular, patients who required cartilage surgery showed nearly half the survival rate compared with those with required no cartilage procedures at 10-year follow-up (36.4% vs 71%, respectively; P = .029). Conclusion: Female sex and the need to combine MAT with a cartilage procedure or ACL reconstruction could result in an increased rate of clinical failure at midterm follow-up.

(1) Background: We aimed to compare gender differences in knee biomechanics and neuromuscular characteristics, and to determine the relationships between lower limb muscle pre-activations and knee biomechanics during a single leg drop landing, in order to identify riskier landing patterns to prevent injury and intervene properly. (2) Methods: Descriptive laboratory cross-sectional study on 38 healthy untrained subjects with low to moderate physical activity status. (3) Results: During the initial-contact phase of landing, females demonstrated greater peak vertical ground reaction force (GRF) normalized to body weight (49.12 ± 7.53 vs. 39.88 ± 5.69 N/kg; p < 0.001; Hedge’s g = 1.37), peak knee anterior reaction force normalized to body weight (0.23 ± 0.04 vs. 0.17 ± 0.05 N/kg; p < 0.001; Hedge’s g = 1.33), and decreased pre-activation of the semitendinosus (45.10 ± 20.05% vs. 34.03 ± 12.05%; p = 0.04; Hedge’s g = 0.67). The final regression equation was peak knee anterior reaction force = 0.024 + 0.025 (peak knee flexion moment) − 0.02 (semitendinosus-to-vastus lateralis pre-activation ratio) + 0.003 (peak vertical GRF) (R2 = 0.576, p < 0.001). (4) Conclusions: Overall, the data provided in this study support that a reduced semitendinosus-to-vastus lateralis pre-activation ratio predicted an increase in knee anterior reaction force and potentially an increase in ACL forces. Female non-athletes had gender-specific landing characteristics that may contribute to ACL injury. Future studies are warranted to consider more possible predictors of non-contact ACL injury.

Aim: There are few studies in the literature evaluating the effect of the day of surgery on length of hospital stay. This study evaluates the effect of the day of surgery on the duration of hospitalization in unilateral primary total knee arthroplasty (TKA) in a group of hospitals providing wide-ranging health services and clarifies the implications for reducing economic burdens. Methods: Between March 2020 and January 2022, patients treated by TKA with the code P612420 according to the Health Practice Communique were retrospectively scanned in a group of hospitals with different levels. Patients who underwent bilateral TKA on the same day or during hospitalization, underwent any secondary surgical procedures, or developed early complications were excluded from the evaluation. Results: The data of 743 patients who underwent unilateral TKA were evaluated. The mean hospital stay was 3.32 (2-14) days. It was seen that the shortest hospitalization periods were in the surgeries performed on Saturday (3.15 days), while the longest ones were on Friday (3.62 days). It was found that the patients who underwent surgery on Saturday had significantly shorter hospital stays than on Friday (p=0.006). Conclusion: While planning TKA, the choice of surgery day is a factor that should be addressed to reduce hospital stays and, therefore, costs. © 2022 by The Medical Bulletin of Istanbul Haseki Training and Research Hospital The Medical Bulletin of Haseki published by Galenos Yayinevi. 2-s2.0-85143507178

Evaluation and management of multiligament knee injuries (MLKI) require a comprehensive understanding of anatomy and biomechanics. In addition to a thorough history and physical examination, stress radiographs provide a reliable method to assess knee stability. Single-stage anatomic reconstruction techniques should be performed, as they restore native knee kinematics and enable early knee range of motion and superior outcomes.

The purpose of this study was to identify sex differences in lower limb kinematics, kinetics, and muscle activation patterns between individuals with osteoarthritis and healthy controls during a two-legged squat.Thirty OA (15 females) and 30 healthy (15 females) participants performed three 2-legged squats. Sagittal and frontal plane hip, knee, and ankle kinematics and kinetics were calculated. Two-way ANOVAs (Sex X OA Status) were used to characterize differences in squatting strategies between sexes and between those with and without knee OA.A greater decrease in sagittal hip, knee, and ankle range of motion and knee joint power was observed in the OA participants compared to the healthy controls. Females with OA had significantly reduced hip and knee adduction angles compared to the healthy females and males with OA. Females also had decreased hip power, hip flexion, and hip adduction moments and knee adduction moments compared to their male counterparts, with the greatest deficits observed in the females with OA. Females with OA also had the highest magnitude of muscle activation for the quadriceps, hamstrings, and gastrocnemius throughout the squat, while males with OA showed increased activation of the vastus lateralis and medial gastrocnemius compared to the healthy males.OA significantly altered biomechanics and neuromuscular control during the squat, with males employing a hip-dominant strategy, allowing them to achieve a greater lower limb range of motion.

The iliotibial band together with its attachment to the distal femur, known eponymously as the Kaplan fibers, has been shown to contribute to anterolateral rotatory stability of the knee. However, there remains paucity of data regarding the detailed anatomy of the Kaplan fibers to aid us in anatomical-based surgical reconstruction of these structures. The aim of our study was to identify and compare the presence and quantitative anatomy of the Kaplan fibers in Caucasian and Asian cadavers.Twenty paired fresh-frozen Asian and 20 unpaired embalmed Caucasian cadaveric knees were dissected using a standard outside-in technique. The presence, qualitative and quantitative measurements of any distal femoral attachments of the iliotibial band were recorded. Mean values of its dimensions were calculated and compared between the Caucasian and Asian groups.A consistent supracondylar attachment of the iliotibial band was found in all Caucasian knees and in 19 of 20 Asian knees. The fibers were noted to have two variations with regard to their insertion to the distal femur, either as a single limb or as a double limb attachment, averaging between 30 mm and 40 mm from the lateral femoral epicondyle. No statistically significant difference was noted in dimensions of the fibers between the Caucasian and Asian groups.The Kaplan fibers are a consistent attachment of the iliotibial band at the distal femur in both Caucasian and Asian knees with two different patterns of insertion. Surgical reconstructions should aim to recreate these attachments to be as anatomically based as possible.

Lateral collateral ligament (LC) injuries that go unnoticed when associated with an anterior cruciate ligament (ACL) tear can increase stress forces on the ACL graft causing its failure. Furthermore, it is a main stabilizer to varus stress and external rotation. On the other hand, the reinforcement of anterolateral structures during ACL reconstruction has regained popularity in recent years, because evidence has shown that it increases the control of rotational laxity and decreases ACL graft failures, especially in revision surgery. The present article shows a technique to perform an ACL reconstruction, associated with the reconstruction of the LCL and of the anterolateral ligament using a single Achilles tendon allograft, which is split after the fixation of the ACL graft into two fascicles.

Aim: This study aimed to determine the frequency of malignant bone tumors (primary and metastatic) seen around the knee in our region, the patients’ type and demographic characteristics, and the treatments’ outcomes. Material and Method: A retrospective analysis of the patients who were diagnosed and treated with histopathologically malignant tumors in the knee region in our hospital between 2004-2021 was performed from the hospital database. Patients’ complaints, demographic information, and diagnostic and imaging findings were examined. In addition, tumor types, tumor localization, and treatments applied were analyzed. Results: Malignant bone tumor was detected in 88 (35.7%) of 246 patients included in the study. The patients were 48 women and 40 men, with a mean age of 39.72±21.8 (6-76 years). A total of 88 patients were divided into the pediatric group (

Purpose: Risk factors for meniscal tears play a decisive role in deciding on treatment and rehabilitation. The purpose of this study was to investigate the effect of tibial rotation on medial meniscus posterior horn tears (MMPHTs). Methods: This study is a retrospective case–control study. Fifty patients with meniscal tears and 57 knees with intact meniscus were compared. Tibial rotation, femoral version, tibial slope and knee varus were measured in each participant. Knee osteoarthritis was classified according to the Kellgren–Lawrence classification. Demographic characteristics were noted. Results: There were significant differences in the mean tibial torsion angles and mean mechanical axes between the groups. The mean tibial rotation and mean mechanical axis were 26.3° ± 6.7 and 3.7° ± 2.7 in the MMPHT group and 30.3° ± 8.4 and 2.05° ± 2.7 in the control group, respectively (p = 0.008, p = 0.002). Conclusion: The current retrospective study has shown that tibial rotation is markedly reduced in patients with MMPHTs. Although the actual mechanism is not clear, the internal torsion of the tibia causes a decrease in the foot progression angle and increases the knee adduction moment, which in turn increases the medial tibial contact pressure. Internal torsion of the tibia, such as knee varus, may play a role in the aetiology of MMPHTs by this way. Whilst there was a significant difference in the mean varus and tibial torsion between the groups, there was no significant difference in the mean femoral version or tibial slope. Level of evidence: III. WOS:000858649600002 Q1

The prevalence of musculoskeletal injuries in sweep rowing is high. As nearly 50% of power during sweep rowing is contributed by the legs, the presence of muscle imbalances may predispose rowers to overuse injuries. The purpose of the study was to assess knee muscle strength symmetry between dominant and non-dominant limbs of male and female rowers. A descriptive, quantitative research design was used. Twenty-four male and 13 female rowers aged 18–26 years participated. Bilateral isokinetic knee flexion and extension peak torque and hamstrings/quadriceps (H/Q) ratios were assessed at 60°/s and 180°/s using an isokinetic dynamometer. The data was analysed using Mann-Whitney U and Wilcoxon rank tests and significance was set at p≤0.05. In males, the dominant knee extension torque values at 60°/s and 180°/s were significantly larger than that of the non-dominant side (p≤0.05). In females, the non-dominant eccentric H/Q ratio at 60°/s was 15% larger than that of the dominant side (p=0.019). Bilateral differences observed in knee extension torque for males and in H/Q ratio for females highlight the need for isokinetic testing of sweep rowers, to improve performance and prevent injury.

A 52-year-old man presented with a 6-month history of lower limb swelling that has acutely worsened over the last month. He was diagnosed with syphilis more than 5 years ago. Plain radiograph of the knee done on presentation demonstrated deformity, debris, disorganisation and maintenance of bone

Context Athletes with anterior cruciate ligament (ACL) reconstruction (ACLR) exhibit increased cortical motor planning during simple sensorimotor tasks compared with healthy athletes serving as control groups. This may interfere with proper decision making during time-constrained movements, elevating the reinjury risk. Objective To compare cortical motor planning and biomechanical stability during jump landings between participants with ACLR and healthy individuals. Design Cross-sectional study. Setting Laboratory. Patients or Other Participants Ten men with ACLR (age = 28 ± 4 years, time after surgery = 63 ± 35 months) and 17 healthy men (age = 28 ± 4 years) completed 43 ± 4 preplanned (landing leg shown before takeoff) and 51 ± 5 unplanned (visual cue during flight) countermovement jumps with single-legged landings. Main Outcome Measure(s) Movement-related cortical potentials (MRCPs) and frontal θ frequency power before the jump were analyzed using electroencephalography. Movement-related cortical potentials were subdivided into 3 successive 0.5-second time periods (readiness potential [RP]-1, RP-2, and negative slope [NS]) relative to movement onset, with higher values indicating more motor planning. Theta power was calculated for the last 0.5 second before movement onset, with higher values demonstrating more focused attention. Biomechanical landing stability was measured via peak vertical ground reaction force, time to stabilization, and center of pressure. Results Both the ACLR and healthy groups evoked MRCPs at all 3 time periods. During the unplanned task analyzed using P values and Cohen d, the ACLR group exhibited slightly higher but not different MRCPs, achieving medium effect sizes (RP-1: P = .25, d = 0.44; RP-2: P = .20, d = 0.53; NS: P = .28, d = 0.47). The ACLR group also showed slightly higher θ power values that were not different during the preplanned (P = .18, d = 0.29) or unplanned (P = .42, d = 0.07) condition, achieving small effect sizes. The groups did not differ in their biomechanical outcomes (P values > .05). No condition × group interactions occurred (P values > .05). Conclusions Our jump-landing task evoked MRCPs. Although not different between groups, the observed effect sizes provided the first indication that men with ACLR might have consistently relied on more cortical motor planning associated with unplanned jump landings. Confirmatory studies with larger sample sizes are warranted.

This study aims to find a correlation between bone marrow lesions (BMLs) in knee MRI and pathologies of joint structures. In addition, according to the six-letter system classification, the authors analyzed a potential association between the area affected by BMLs and the specific type of joint lesion.The authors screened all the knee MRIs performed in the investigation center between 2017 and 2018 to identify the presence of BMLs. The lesions were then categorized following the "six-letter system". The authors searched the presence of associated meniscal, chondral or ligamentous lesions. Finally, the authors researched a correlation between the lesion type described by the six-letter system classification and the associated lesions.MRI exams of 4000 patients were studied, identifying 666 BMLs. The associated lesions were collected for all patients, resulting in an overall prevalence of related lesions in almost 90% of patients. The authors found a statistical significance for type TLD (Tibia-Lateral-Articular) and ACL rupture. The study suggests a strong positive correlation between type E (Edge) and meniscal fracture or extrusion.BMLs in the knee are associated in 90% of cases with a radiological sign of related injury to the joint structures. The six-letter system of BMLs type TLD can be considered a sign of ACL rupture and type E as a high suspicious sign for meniscal extrusion. Those very typical BML patterns can help the clinician in the diagnosis of ACL tears and meniscal extrusion. Furthermore, the presence of a BML must be, for the clinician, a high suspicious sign of joint-related injuries.Level 1.

What is the central question of this study? Can bilateral knee extensor force accuracy be improved following 4 weeks of unilateral force accuracy training and are there any subsequent alterations to central and/or peripheral motor unit features? What is the main finding and its importance? In the trained limb only, knee extensor force tracking accuracy improved with reduced motor unit firing rate variability in the vastus lateralis, and there was no change to neuromuscular junction transmission instability. Interventional strategies to improve force accuracy may be directed to older/clinical populations where such improvements may aid performance of daily living activities.Muscle force output during sustained submaximal isometric contractions fluctuates around an average value and is partly influenced by variation in motor unit (MU) firing rates. MU firing rate (FR) variability seemingly reduces following exercise training interventions; however, much less is known with respect to peripheral MU properties. We therefore investigated whether targeted force accuracy training could lead to improved muscle functional capacity and control, in addition to determining any alterations of individual MU features. Ten healthy participants (seven females, three males, 27 ± 6 years, 170 ± 8 cm, 69 ± 16 kg) underwent a 4-week supervised, unilateral knee extensor force accuracy training intervention. The coefficient of variation for force (FORCE

The diverse and grueling nature of activities undertaken during Special Forces selection makes it difficult to develop physical training to improve performance and reduce injury risk. It is generally accepted that increased strength is protective against injury, but it is unclear if this is evident in a Special Forces selection environment. This study investigated the effect of the rigors of a Special Forces selection course has on performance of the isometric mid-thigh pull, countermovement jump, squat jump, drop landing, elastic utilization ratio (EUR), and injury occurrence. Throughout the course, 26% of participants sustained a preventable lower limb injury, with 65% of these occurring at the knee. The uninjured had higher values of absolute strength as measured by isometric mid-thigh pull peak absolute force (3399 [371] N, 3146 [307] N; P = .022) and lower EUR (0.94 [0.08], 1.01 [0.09]; P = .025) compared to the injured. Preventable knee injury was significantly correlated with isometric mid-thigh pull (r = −.245, P = .031) and EUR (r = .227, P = .044). The selection course altered EUR for uninjured individuals only (P = .004). Findings indicate that individuals with higher strength levels may be at a lower risk of injury than their weaker counterparts.

To report the radiographic landmarks for the medial patellofemoral complex (MPFC) footprint on the medial femur and describe the difference between the radiographic positions corresponding to the medial quadriceps tendon femoral ligament (MQTFL) and medial patellofemoral ligament (MPFL) fibers.In 8 unpaired cadaveric knees, the MPFC footprint was exposed on the medial femur, and the proximal and distal boundaries of the footprint were marked. Lateral fluoroscopic images of the knee were obtained and analyzed using Image J. The proximal boundary corresponding to the MQTFL, the MPFC midpoint, and distal boundary corresponding to the MPFL were described radiographically and compared for differences in position.The proximal MQTFL footprint was 0.8 ± 0.6 mm anterior (P = .013) and 5.2 ± 1.8 mm proximal to the MPFC midpoint (P.001), whereas the distal MPFL footprint was 0.8 ± 0.7 mm posterior (P = .012) and 5.9 ± 1.1 mm distal to the radiographic MPFC midpoint (P.001). The radiographic point corresponding to the distal MPFL footprint was 0.8 ± 0.9 mm posterior (P = .011) and 11.1 ± 2.3 mm distal to the radiographic point of the proximal MQTFL footprint (P.001). When using the point of intersection of the posterior cortical line and the proximal posterior condyle as a reference, 91.6% of all points correlating to the MQTFL, MPFC midpoint and MPFL, were within 10 mm in any direction from this radiographic landmark.On fluoroscopic imaging, the proximal MQTFL and distal MPFL fibers had significantly different radiographic positions from the MPFC midpoint on the femur. These findings should be considered when reconstructing specific components of the MPFC.As fluoroscopy is often used intraoperatively to guide graft placement, our findings may serve as a reference when differentiating the locations of the MPFL vs MQTFL on the femur for anatomic reconstruction.

Context: Both isokinetic testing and functional tests are often used during patient rehabilitation programs. Most researchers have assessed the relationship of isokinetic testing and functional tests in parameters such as peak moment, work, or power. However, little information exists regarding the acceleration and deceleration parameters and their relationship to function. Design: The purpose of the study was to investigate the concept of acceleration and deceleration of the knee flexor and extensor muscle groups during isokinetic testing and its relationship to function. Methods: Twenty-six healthy individuals (14 men and 12 women) participated in the study. Isokinetic bilateral concentric knee flexion and extension muscular performance was assessed isokinetically at the angular velocities of 60°/s, 180°/s, and 300°/s. Functional performance was also assessed using (1) single hop for distance, (2) triple hop for distance, and (3) single timed hop. Functional data were normalized to body weight. A P value Results: Fair and moderate to good correlations (r = .396, P = .045 to r = .705, P = .001) were discovered between flexors’ and extensors’ acceleration/deceleration variables and the normalized to body weight functional tests. Conclusions: Appropriate understanding of isokinetic parameters as described in this study, including acceleration/deceleration values, may provide useful information about the functional ability of the lower limb muscular system.

We aimed to investigate the clinical and functional outcomes, including maximal and explosive strength, after chronic quadriceps tendon rupture repair with Modified Pulvertaft on Weave (MPW) technique METHODS: Knee joint range of motion (ROM), patella height, thigh circumference, and Lysholm and International Knee Documentation Committee (IKDC) scores were assessed preoperatively and postoperatively. The knee extensors maximal (isokinetic peak torque and isometric maximal voluntary contraction (MVC) torque) and explosive strength-rate of torque development (RTD) early [RTDNine patients (mean age: 53 ± 11 years) took part in the study. We observed a significant increase in the knee active ROM and a decreased extension deficit (both, P.001), but not for pain (P = .07), IKDC (P = .07), and Lysholm (P = .21) after the surgery. We did not observe a difference between involved (n = 8) and uninvolved (n = 10) limbs for ROM, thigh circumference, and MT. We observed differences for extensors peak torque, MVC torque, and late RTD (all, P.05). However, we did not observe differences for early RTD and EMGThe MPW reestablished the active knee extension. The same level of quadriceps muscle mass was observed in both limbs, suggesting a lack of hypotrophy due to the injury. Although the involved limb had demonstrated lower knee extensors maximal strength, they demonstrate an equivalent early RTD when compared to the uninvolved limb. The early RTD seems to be better correlated with the patient's functionality than the later RTD and maximal strength.IV, case series.

Knee extensor (KE) weakness is commonly exhibited in individuals with knee osteoarthritis (KOA) and may contribute to disability due an increased muscle functional demand and resulting compensatory gait strategies during locomotion. Muscle functional demand is defined as the percentage of maximal strength that is used during a task.The study aim was to quantify KE functional demand in KOA, the impact of walking speed and the relationships with the relative joint contribution to total limb work.Fourteen individuals with symptomatic KOA underwent gait analysis at preferred and faster speeds and isokinetic dynamometry for KE maximum voluntary isometric torque. The KE functional demand as well as the relative and peak joint work and powers were calculated. Paired samples t-test was used to compare functional demand and relative work between speeds and Pearson's correlation was used to assess the relationship between relative work and functional demand values (α = 0.05).The KE functional demand was 36.0 ± 15.7 % for the preferred speed and significantly higher at 49.8 ± 16.1 % for the faster speed, (t(13) = -5.45, p .05). Knee flexion moment was also significantly higher for the faster speed (t(13) = -5.54, p .001). There were significant relationships between fast speed functional demand and relative ankle negative power (r = -0.57) and relative ankle positive work (r = 0.66), (all p .05).The results suggest that as functional demand nears or exceeds 50 % of the muscle capacity individuals with KOA reduce the relative effort at the knee and use an ankle-based compensation strategy to meet task demands.

The effect of the Posterior X Taping (PXT) used for subjects with Tibiofemoral Varus Malalignment (TFRV) aimed to control excessive tibiofemoral rotations is still unclear. Further, it is critical to use evidence-based therapeutic exercises to prevent non-contact injuries, especially in repetitive movements.To investigate whether the PXT and real-time feedback (RTF) interventions would improve lower extremity functions during the pedaling task in subjects with TFRV.Twenty-four male recreational athletes with TFRV participated in this study; Kinematic and muscle activity were synchronously recorded on ten consecutive pedal cycles during the last 30 s of 2-min pedaling.The present study indicated that the subjects at the post-intervention of the RTF group exhibited significant decreased hip adduction and internal rotation, significant decreased tibiofemoral external rotation between 144° and 216° of crank angle, significant increased vastus medialis activity between 144° and 288° of crank angle, and significant increased gluteus medius activity between 180° and 144° of crank angle; In contrast, the subjects at the post-intervention of the PXT group exhibited significant decreased tibiofemoral external rotation and increased ankle external rotation at all the crank angles. No between-group differences were observed in pre-and post-intervention.These results suggest that the PXT and RTF interventions are recommended to immediately improve the functional defects of the subjects with TFRV during the pedaling task.

This systematic review investigated whether people with patellofemoral osteoarthritis (PFOA) have muscle strength, volume, and activation around the hip and knee that is different from asymptomatic controls.Searches were carried out in five electronic databases, with terms related to PFOA, including muscle strength, volume and activation. Only studies with at least one group with symptomatic PFOA and one asymptomatic group were included. The methodological quality of the studies was assessed using the Downs and Black checklist. Certainty of evidence was assessed using the GRADE methodology. Using the random effects model, a meta-analysis was performed when there were at least two studies reporting the same domain.Eight studies (250 participants) met the inclusion criteria. Subjects with PFOA had weaker hip abduction (SMD -0.96; 95%CI = -1.34 to -0.57), hip external rotation (-0.55;-1.07 to -0.03), hip extension (-0.72;-1.16 to -0.28), and knee extension (-0.97;-1.41 to -0.53) when compared to asymptomatic controls. People with PFOA also presented with smaller volumes of the gluteus medius, gluteus minimus, tensor fascia lata, vastus medialis (VM), vastus lateralis (VL) and rectus femoris when compared to asymptomatic controls. Also, people with PFOA presented with changes in muscle activation for the VL, VM and gluteus maximus (GMax) when compared to asymptomatic controls.People with PFOA present with lower strength and volume of the hip and quadriceps muscles and altered muscle activation of the VM, VL and GMax during ascending and descending stairs when compared to asymptomatic controls. However, the certainty of these findings are very low.PROSPERO systematic review protocol (ID = CRD42020197776).

Aims The aim of this study was to estimate time to arthroplasty among patients with hip and knee osteoarthritis (OA), and to identify factors at enrolment to first-line intervention that are prognostic for progression to surgery. Methods In this longitudinal register-based observational study, we identified 72,069 patients with hip and knee OA in the Better Management of Patients with Osteoarthritis Register (BOA), who were referred for first-line OA intervention, between May 2008 and December 2016. Patients were followed until the first primary arthroplasty surgery before 31 December 2016, stratified into a hip and a knee OA cohort. Data were analyzed with Kaplan-Meier and multivariable-adjusted Cox regression. Results At five years, Kaplan-Meier estimates showed that 46% (95% confidence interval (CI) 44.6 to 46.9) of those with hip OA, and 20% (95% CI 19.7 to 21.0) of those with knee OA, had progressed to arthroplasty. The strongest prognostic factors were desire for surgery (hazard ratio (HR) hip 3.12 (95% CI 2.95 to 3.31), HR knee 2.72 (95% CI 2.55 to 2.90)), walking difficulties (HR hip 2.20 (95% CI 1.97 to 2.46), HR knee 1.95 (95% CI 1.73 to 2.20)), and frequent pain (HR hip 1.56 (95% CI 1.40 to 1.73), HR knee 1.77 (95% CI 1.58 to 2.00)). In hip OA, the probability of progression to surgery was lower among those with comorbidities (e.g. ≥ four conditions; HR 0.64 (95% CI 0.59 to 0.69)), with no detectable effects in the knee OA cohort. Instead, being overweight or obese increased the probability of OA progress in the knee cohort (HR 1.25 (95% CI 1.15 to 1.37)), but not among those with hip OA. Conclusion Patients with hip OA progressed faster and to a greater extent to arthroplasty than patients with knee OA. Progression was strongly influenced by patients’ desire for surgery and by factors related to severity of OA symptoms, but factors not directly related to OA symptoms are also of importance. However, a large proportion of patients with OA do not seem to require surgery within five years, especially among those with knee OA. Cite this article: Bone Joint J 2022;104-B(7):792–800.

People who suffer from stroke have a higher difficulty performing gait activity, affecting their quality of life. New technologies have been developed to assist and rehabilitate the affected limbs. This paper presents the AGoRA V2 unilateral lower-limb exoskeleton and the assessment of physiological and spatiotemporal parameters of gait in 10 subjects who participated in a test. AGORA V2 combine a stiff structure for the Hip and Knee and the T-FLEX ankle exoskeleton (soft structure). The results showed a significant decrease in muscle activity compared to the condition without an exoskeleton. This decrease was 8% in Biceps Femoris (BF) muscle activity and 4% in Vastus Medialis (VM) muscle activity, generated by proper assistance of the devices thigh muscles. Tibialis Anterior (TA) and Lateral Gastrocnemius (LG) muscles and gait times did not show significant changes, which can be interpreted as a correct synchronisation of the devices with the person’s gait. The results obtained can be used as a baseline for future studies with pathological patients.

Prophylactic knee braces (PKBs) are widely used by athletes in pivoting and landing sports and have the potential to influence knee movement and alignment, thus modulating anterior cruciate ligament (ACL) injury risk. This systematic review analyses current evidence on the biomechanical effects that PKBs have in the prevention of ACL injuries.The review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Searches were conducted on PubMed, Web of Science, Scopus, Ovid MEDLINE, EMBASE, Cochrane, and CINAHL for studies published from inception until May 31, 2021. Included studies assessed the effects of PKBs on biomechanical variables associated with ACL injuries in landing or pivoting tasks, comparing between braced and unbraced conditions.A total of 234 articles were identified; from which, 14 controlled, laboratory, biomechanical studies were included in this review. The effects of PKBs on knee biomechanics could be divided into kinematic variables in the coronal, sagittal, and transverse planes; and common kinetic variables, such as ground reaction force (GRF) and ACL load/strain. Also, PKBs were found to have protective effects in coronal and transverse plane kinematics, but results in the sagittal plane were inconclusive. Assessing knee kinetics, PKBs were advantageous in decreasing ACL load/strain but had no significant effect on GRF.Prophylactic knee braces may serve to reduce ACL injury risk by modulating knee coronal and transverse plane movements and ACL load/strain during high-risk maneuvres. Precise recommendations are limited by study heterogeneity. More prospective studies are needed to assess ACL injury risk during high-risk sports using specific PKBs.

Introduction The objective of this study was to explore race-based differences in 30-day complication rates following total joint arthroplasty (TJA) using a large national database. Methods Patients undergoing primary, elective THA and TKA between 2012 and 2018 were retrospectively reviewed using the ACS-NSQIP. We compared Black and Hispanic patients with non-Hispanic White patients using multivariate statistical models adjusting for demographic, operative, and medical characteristics. Results A total of 324,795 and 200,023 patients undergoing THA and TKA, respectively, were identified. After THA, compared to White patients, Black and Hispanic patients were more likely to be diagnosed with VTE (p p p p p = 0.008, respectively), be diagnosed with VTE (p p Conclusions Our findings indicate higher rates of VTE, blood transfusions, and discharge to an inpatient facility for Black and Hispanic patients when compared to White patients following TJA, though we are unable to comment on the etiology of these disparities. These results may contribute to a growing divide with respect to outcomes and access to TJA for these at-risk patient populations.

Dynamic knee valgus (DKV) is a frontal plane knee kinematic alteration that has been associated with patellofemoral pain (PFP) in female runners. DKV is commonly assessed in clinical practice by measuring frontal plane knee projection angle (FPPA) during squat tests. However, it remains unclear whether the DKV observed in these tests is similar to or correlates with that observed during running in female runners. The aims of this cross-sectional study were to correlate and compare DKV, by measuring FPPA values, in a lateral step-down (LSD) squat test and running in female runners with and without PFP. A two-dimensional (2D) video analysis of the LSD test and running was carried out for 21 asymptomatic female runners and 17 PFP female runners in order to determine FPPA values. A Pearson correlation test and a factorial ANOVA with Bonferroni post hoc correction were used for statistical analysis. The FPPAs recorded in the LSD test were significantly higher than those recorded during running in the asymptomatic (16.32° ± 5.38 vs. 4.02° ± 3.26, p < 0.01) and PFP groups (17.54° ± 7.25 vs. 4.64° ± 3.62, p < 0.01). No significant differences were found in FPPA values between asymptomatic and PFP runners during the LSD test (16.32° ± 5.38 vs. 17.54° ± 7.25, p = 0.55) and running (4.02° ± 3.26 vs. 4.64° ± 3.62, p = 0.58). There was a small (r < 0.3) and non-significant (p > 0.05) correlation in FPPAs between the LSD test and running in both groups. According to our results, DKV was not similar during the LSD test and running, and there was no significant correlation in FPPA values between the LSD test and running in both groups. Therefore, clinicians and therapists should be aware of these findings when using the LSD test in clinical practice to evaluate DKV in female runners with or without PFP.

Frontal plane postures during the ultimate step of sidestepping are linked to increased anterior cruciate ligament injury risk. However, there is a lack of research detailing the kinematic strategies present in the penultimate step. This study, therefore, investigated penultimate and ultimate step kinematics of planned sidestepping (pSS) and unplanned sidestepping (upSS) to further understand the effect of planning time on known ultimate step kinematic and kinetic differences. Sixty male amateur Australian Rules football players performed three trials of straight-line running (RUN), pSS, and upSS in a randomized order. Mediolateral foot placement and three-dimensional joint kinematics for the knee, pelvis, and trunk were measured at final foot contact of the penultimate step and initial foot contact of the ultimate step. Peak knee moments were measured during the weight acceptance phase of the ultimate step. In pSS, at the penultimate step final foot contact, the support foot was placed across the midline of the center of mass, in the frontal plane, contralateral to the sidestep direction. Greater trunk lateral flexion toward the sidestep direction and greater negative pelvic lateral tilt were observed in pSS compared with upSS and RUN. Differences between pSS and upSS frontal plane kinematics at penultimate step final foot contact suggest preparatory reorientation strategies are likely constrained by the amount of planning time available. As there are clear differences in preparatory kinematics, we recommend that planning time be considered when training and assessing sidestepping maneuvers and planned and unplanned maneuvers not be treated as interchangeable skills.

Large inter-individual variability of activation strategies is observed during hamstring strengthening exercises but their consequences remain unexplored. The objective of this study was to determine whether individual activation strategies are related to the distribution of damage across the hamstring muscle heads semimembranosus (SM), semitendinosus (ST), and biceps femoris (BF) after eccentric contractions. 24 participants performed 5 sets of 15 maximal eccentric contractions of knee flexors on a dynamometer, while activation of each muscle head was assessed using surface electromyography. Knee flexion maximal isometric strength was assessed before exercise and 48 h afterward. Shear modulus was measured using shear wave elastography before exercise and 30 min afterward to quantify the distribution of damage across the hamstring muscle heads. At 48 h, maximal knee flexion torque had decreased by 15.9% ± 16.9% (p 0.001). Although no differences between activation ratios of each muscle were found during the eccentric exercise (all p 0.364), we reported a heterogeneous distribution of damage, with a larger change in shear modulus of ST/Hams than SM/Hams (+70.8%, p 0.001) or BF/Hams (+50.3%, p 0.001). A large correlation was found between the distribution of activation and the distribution of damage for ST/Hams (r = 0.69; p 001). This study provides evidence that the distribution of activation during maximal eccentric contractions has mechanical consequences for synergist muscles. Further studies are needed to understand whether individual activation strategies influence the distribution of structural adaptations after a training program.

This study aimed to investigate the correlation between the surface area ratio of medial tibial plateau (MTP) to lateral tibial plateau (LTP) and the mechanical tibiofemoral angle (mTFA).Lower limb computed tomography (CT) images were collected at our hospital. Then, the original CT data were analyzed and reconstructed using medical image processing software. The proximal and distal centres of the femur and tibia were marked. The surface areas of MTP and LTP were identified using image processing software. GraphPad Prism 8.0.2 was used to perform the statistical analysis.The surface area ratio of MTP to LTP was significantly correlated with the mTFA in all patients (P0.0001), male group (P0.0001), female group (P0.0001), varus group (P0.0001), and valgus group (P=0.002). Furthermore, the surface area of MTP and LTP was significantly greater in the male group than in the female group (P0.0001). There was significant difference in the surface area of the MTP between the varus and valgus groups (P0.0001). Significant difference was also observed in the surface area ratio of MTP to LTP between the varus and valgus groups (P0.0001).The surface area ratio of MTP to LTP was correlated with the mTFA. Within a certain range, the smaller the mTFA, the greater the surface area ratio of MTP to LTP. For patients undergoing total knee arthroplasty, of whom the surface area of the MTP was basically equal to that of the LTP, it is recommended that the osteotomy should be performed in accordance with mechanical alignment standards, and that a symmetrical tibial plateau prosthesis should be used. For patients whose surface area of MTP is significantly greater than that of the LTP, it is recommended that the osteotomy should be performed in accordance with kinematic alignment standards, and that an anatomical tibial plateau prosthesis should be used.

Reactive stepping is one of the only strategies that can lead to successful stabilization following a large challenge to balance. Improving function of specific muscles associated with reactive stepping may improve features of reactive balance control. Accordingly, this study aimed to determine the relationship between lower limb muscle strength and explosive force with force plate-derived timing measures of reactive stepping. Nineteen young, healthy adults (27.6 ± 3.0 years of age; 10 women: 9 men) responded to 6 perturbations (~13-15% of body weight) using an anterior lean-and-release system (causing a forward fall), where they were instructed to recover balance in as few steps as possible. Foot-off, swing, and restabilization times were estimated from force plates. Peak isokinetic torque, isometric torque, and explosive force of the knee extensors/flexors and plantar/dorsiflexors were measured using isokinetic dynamometry. Correlations were run based on a priori hypotheses and corrected for the number of comparisons (Bonferroni) for each variable. Knee extensor explosive force was negatively correlated with swing time (r = −0.582, p = 0.009). Knee flexor peak isometric torque also showed a negative association with restabilization time (r = −0.459, p = 0.048), however this was not statistically significant after correcting for multiple comparisons. There was no significant relationship between foot-off time and knee or plantar flexor explosive force (p > 0.025). These findings suggest that there may be utility to identifying specific aspects of reactive step timing when studying the relationship between muscle strength and reactive balance control. Exercise training aimed at improving falls risk should consider targeting specific aspects of muscle strength depending on specific deficits in reactive stepping.

This study aimed to examine the acute effects of fast-paced walking on isometric peak torque and rate of torque development (RTD) in regular exercising and inactive older women. Ten regular exercising (67 ± 4 years) and 10 inactive (68 ± 4 years) older women performed three isometric knee extension contractions before and after a control condition (quiet resting) and an experimental condition of fast-paced walking for 6 min. Peak torque and early (RTD100), late (RTD200), and maximum (peak RTD) RTD measurements were obtained from each contraction. Results showed no significant changes in peak torque, peak RTD, or RTD200 after walking for either group (p > .050). A significant decrease in RTD100 was observed after walking for the inactive group (p = .005) but not for the regular exercisers (p = .909). These findings highlight the importance of physical activity and suggest that a task as simple as walking may impair the rapid strength capacities of inactive older women.

IntroductionSingle-stage revision arthroplasty for periprosthetic joint infection (PJI) may yield comparable infection-free survivorship with two-stage revision arthroplasty. It is unclear if the most common mode of failure of single-stage revision arthroplasty is infection or aseptic loosening. In this meta-analysis, we sought to (1) determine survivorship and (2) compare rates of different etiologies of failure of single-stage revision total hip arthroplasty (THA) and total knee arthroplasty (TKA).MethodsPreferred Reporting Items for Systematic Review and Meta-analyses guidelines search was done using search terms for "single stage revision," "exchange arthroplasty," "periprosthetic infection," "PJI," and "single stage." Patient demographics such as age, body mass index, and mean follow-up time were recorded. Overall survivorship and rates of revision surgery were aggregated using a random-effects model. Comparison of septic and aseptic loosening rates was done by risk difference and associated 95% confidence interval (CI) calculation.ResultsTwenty-four studies were identified with 2,062 and 147 single-stage revision THA and TKA procedures performed between 1984 and 2019, respectively. The weighted mean follow-up and age were 69.8 months and 66.3 years, respectively, with 55% men overall. The all-cause revision surgery rate was 11.1% and 11.8% for THA and TKA, respectively. The revision surgery rate secondary to infection and aseptic loosening and associated 95% CI for the risk difference for THA and TKA was 5.5% and 3.3% (-1.7% to 5.0%), and 3% and 8.8% (-11.4% to 2.3%), respectively. Revision surgeries due to instability and fracture combined and mortality rate were both less than 3%.DiscussionSingle-stage revision THA and TKA for PJI demonstrated overall high rates of survivorship, low mortality, and revision surgeries secondary to infection and aseptic loosening to be equivalent. Aseptic loosening after single-stage revision TKA might be higher than in primary TKA. As implant survivorship from infection improves in PJI, surgeons should be aware of aseptic loosening as an equally common mode of failure.

Purpose An observation was made by the senior author of this paper that patients reported changes in their hip function after a medial opening wedge high tibial osteotomy (MOHTO) for varus pattern osteoarthritis. Alignment changes at the hip after MOHTO have not been previously documented. This study assesses coronal alignment changes at the hip after MOHTO. Methods We retrospectively analysed pre- and post-operative lower limb alignment radiographs of patients who underwent MOHTO. The medial proximal tibial angle (MPTA) and mechanical axis deviation (MAD) were measured to assess the alignment changes created by the MOHTO. The coronal alignment changes at the hip were evaluated using the mechanical greater trochanter angle (MGTA). Results 29 osteotomies in 27 patients were included in this study. Results showed MOHTO created alignment changes at the hip. A positive correlation was found between the size of the correction at the knee and the subsequent changes at the hip. The change in the MGTA had a stronger correlation with the MAD than with the change in MPTA (r = 0.684 vs. 0.585). It was found that age, weight, height and BMI had no significant influence on these correlations. Conclusions Increased correction by the MOHTO lead to increased change in the coronal alignment of the hip. These changes are likely to result in an alteration in the weight bearing portion of the femoral head and the function of the abductors and we recommend assessing the hip joint as part of pre-operative planning. Level of evidence Prognostic level IV.

Osteochondral defect or osteochondritis dissecans (OCD) of the knee usually affects young, active populations. It is a challenging diagnosis as patients typically present with poorly localised activity-related pain, which is non-specific and covers many differentials. We present an active 11-year-old girl with bilateral osteochondral defects of the patellae: a rare clinical disorder which was affecting her sporting activities. She had a 12-month history of bilateral anterior knee pain before the diagnosis was achieved with appropriate imaging. Her pain significantly improved with activity modification and physiotherapy. Follow-up will require outpatient clinic assessment and imaging to determine if non-operative management continues to be successful or surgery may be required. This case report emphasises the importance of appropriate high index of suspicion when managing patients with non-specific knee pain. It also demonstrates the importance of judicious use of imaging to avoid a missed or delayed diagnosis.

Context Return-to-activity (RTA) assessments are commonly administered after anterior cruciate ligament reconstruction (ACLR) to manage the patient's postoperative progressions back to activity. To date, few data are available on the clinical utility of these assessments to predict patient outcomes such as secondary anterior cruciate ligament (ACL) injury once the athlete has returned to activity. Objective To identify the measures of patient function at 6 months post-ACLR that best predict RTA and second ACL injury at a minimum of 2 years after ACLR. Design Prospective cohort study. Setting Laboratory. Patients or Other Participants A total of 234 patients with primary, unilateral ACLR completed functional assessments at approximately 6 months post-ACLR. Of these, 192 (82.1%) completed follow-up at ≥2 years post-ACLR. Main Outcome Measure(s) The 6-month functional assessments consisted of patient-reported outcomes, isokinetic knee-flexor and -extensor strength, and single-legged hopping. We collected RTA and secondary ACL injury data at ≥2 years after ACLR. Results Of the patients who were able to RTA (n = 155), 44 (28.4%) had a subsequent ACL injury, 24 (15.5%) to the ipsilateral graft ACL and 20 (12.9%) to the contralateral ACL. A greater proportion of females had a secondary injury to the contralateral ACL (15/24, 62.5%), whereas a greater proportion of males reinjured the ipsilateral ACL graft (15/20, 75.0%; P = .017). Greater knee-extension symmetry at 6 months increased the probability of reinjury (B = 0.016, P = .048). Among patients with RTA at 8 months, every month that RTA was delayed reduced the risk of reinjury by 28.4% (B = –0.284, P = .042). Descriptive statistics of patient function stratified between the early and delayed RTA groups can be found in the Supplemental Table (available online at http://dx.doi.org/10.4085/1062-6050-0407.20.S1). Conclusions Patients with more symmetric quadriceps strength at 6 months post-ACLR were more likely to experience another ACL rupture, especially those who returned to sport at

Background With the worldwide rising obesity epidemic and the aging population, it is essential to deliver (cost-)effective care that results in enhanced societal participation among knee arthroplasty patients. The purpose of this study is to describe the development, content, and protocol of our (cost-)effectiveness study that assesses a perioperative integrated care program, including a personalized eHealth app, for knee arthroplasty patients aimed to enhance societal participation post-surgery compared to care as usual. Methods The intervention will be tested in a multicentre randomized controlled trial with eleven participating Dutch medical centers (i.e., hospitals and clinics). Working patients on the waiting-list for a total- or unicompartmental knee arthroplasty with the intention to return to work after surgery will be included. After pre-stratification on medical centre with or without eHealth as usual care, operation procedure (total- or unicompartmental knee arthroplasty) and recovery expectations regarding return to work, randomization will take place at the patient-level. A minimum of 138 patients will be included in both the intervention and control group, 276 in total. The control group will receive usual care. On top of care as usual, patients in the intervention group will receive an intervention consisting of three components: 1) a personalized eHealth intervention called ikHerstel (‘I Recover’) including an activity tracker, 2) goal setting using goal attainment scaling to improve rehabilitation and 3) a referral to a case-manager. Our main outcome is quality of life, based on patient-reported physical functioning (using PROMIS-PF). (Cost-)effectiveness will be assessed from a healthcare and societal perspective. Data collection has been started in 2020 and is expected to finish in 2024. Discussion Improving societal participation for knee arthroplasty is relevant for patients, health care providers, employers and society. This multicentre randomized controlled trial will evaluate the (cost-)effectiveness of a personalized integrated care program for knee arthroplasty patients, consisting of effective intervention components based on previous studies, compared to care as usual. Trial registration Trialsearch.who.int; reference no. NL8525, reference date version 1: 14–04-2020.

Purpose Excision of the posterior cruciate ligament (PCL) is recommended when implanting a medial pivot (MP) total knee arthroplasty (TKA) to reduce the risk of limiting flexion by over-tensioning the flexion space. The present study determined whether PCL retention (1) limits internal tibial rotation and (2) causes anterior lift-off of the insert in 90° flexion after implantation of an MP design with unrestricted caliper verified kinematic alignment (KA). Methods Four surgeons implanted an MP TKA design with medial ball-in-socket and lateral flat tibial insert in ten fresh-frozen cadaveric knees. Before and after PCL excision, trial inserts with medial goniometric markings measured the angular I–E tibial orientation relative to the trial femoral component's medial condyle in extension and at 90° flexion, and the surgeon recorded the occurrence of anterior lift-off of the insert at 90° flexion. Results PCL retention resulted in greater internal tibial rotation than PCL excision, with mean values of 15° vs 7° degrees from maximum extension to 90° flexion, respectively (p Conclusions This preliminary study of ten cadaveric knees showed that PCL retention restored more passive internal tibial rotation than PCL excision with a negligible risk of anterior lift-off. However, in vivo analysis from multiple authors with a larger sample size is required to recommend PCL retention with an MP TKA design implanted with unrestricted caliper verified KA.

Background and purpose: The main treatments for severe medial compartment knee arthritis are unicompartmental (UKR) and total knee replacement (TKR). UKRs have higher revision rates, particularly for aseptic loosening, therefore the cementless version was introduced. We compared the outcomes of matched cementless UKRs and TKRs.Patients and methods: The National Joint Registry was linked to the English Hospital Episode Statistics and Patient Reported Outcome Measures (PROMs) databases. 10,552 cementless UKRs and 10,552 TKRs were propensity matched and regression analysis used to compare revision/reoperation risks. 6-month PROMs were compared. UKR results were stratified by surgeon caseload into low- (< 10 UKRs/year), medium- (10 to < 30 UKRs/year), and high-volume (≥ 30 UKRs/year).Results: 8-year cementless UKR revision survival for the 3 respective caseloads were 90% (95% CI 87–93), 93% (CI 91–95), and 96% (CI 94–97). 8-year reoperation survivals were 76% (CI 71–80), 81% (CI 78–85), and 84% (CI 82–86) respectively. For TKR the 8-year implant survivals for revision and reoperation were 96% (CI 95–97) and 81% (CI 80–83). The HRs for the 3 caseload groups compared with TKR for revision were 2.0 (CI 1.3–2.9), 2.0 (CI 1.6–2.7), and 1.0 (CI 0.8–1.3) and for reoperation were 1.2 (CI 1.0–1.4), 0.9 (CI 0.8–1.0), and 0.6 (CI 0.5–0.7). 6-month Oxford Knee Score (OKS) (39 vs. 37) and EQ-5D (0.80 vs. 0.77) were higher (p < 0.001) for the cementless UKR.Interpretation: Cementless UKRs have higher revision and reoperation rates than TKR for low-volume UKR surgeons, similar reoperation but higher revision rates for mid-volume surgeons, and lower reoperation and similar revision rates for high-volume surgeons. Cementless UKR also had better PROMs.

Background:Both the superficial medial collateral ligament (sMCL) and the deep MCL (dMCL) contribute to the restraint of anteromedial (AM) rotatory instability (AMRI). Previous studies have not investigated how MCL reconstructions control AMRI.Purpose/Hypothesis:The purpose was to establish the optimal medial reconstruction for restoring normal knee kinematics in an sMCL- and dMCL-deficient knee. It was hypothesized that AMRI would be better controlled with the addition of an anatomically shaped (flat) sMCL reconstruction and with the addition of an AM reconstruction replicating the function of the dMCL.Study Design:Controlled laboratory study.Methods:A 6 degrees of freedom robotic system equipped with a force-torque sensor was used to test 8 unpaired knees in the intact, sMCL/dMCL sectioned, and reconstructed states. Four different reconstructions were assessed. The sMCL was reconstructed with either a single-bundle (SB) or a flattened hamstring graft aimed at better replicating the appearance of the native ligament. These reconstructions were tested with and without an additional AM reconstruction. Simulated laxity tests were performed at 0°, 30°, 60°, and 90° of flexion: 10 N·m valgus rotation, 5 N·m internal and external rotation (ER), and an AM drawer test (combined 134-N anterior tibial drawer in 5 N·m ER). The primary outcome measures of this force-controlled setup were anterior tibial translation (ATT; in mm) and axial tibial rotation (in degrees).Results:Sectioning the sMCL/dMCL increased valgus rotation, ER, and ATT with the simulated AM draw test at all flexion angles. SB sMCL reconstruction was unable to restore ATT, valgus rotation, and ER at 30°, 60°, and 90° of flexion to the intact state ( P < .05). Flat MCL reconstruction restored valgus rotation at all flexion angles to the intact state ( P > .05). ER was restored at all angles except at 90°, but ATT laxity in response to the AM drawer persisted. Addition of an AM reconstruction improved control of ATT relative to the intact state at all flexion angles ( P > .05). Combined flat MCL and AM reconstruction restored knee kinematics closest to the intact state.Conclusion:In a cadaveric model, AMRI resulting from an injured sMCL and dMCL complex could not be restored by an isolated SB sMCL reconstruction. A flat MCL reconstruction or an additional AM procedure, however, better restored medial knee stability.Clinical Relevance:In patients evaluated with a combined valgus and AM rotatory instability, a flat sMCL and an additional AM reconstruction may be superior to an isolated SB sMCL reconstruction.

BackgroundThere are few effective pain treatments following trauma on the battlefield other than opioids, which are limited by respiratory depression. Ultrasound-guided percutaneous peripheral nerve stimulation ("neuromodulation") has been proposed as an analgesic, but requires physician-level skills, advanced equipment, and an hour to administer. In contrast, percutaneous auricular neuromodulation may be placed by a medic in the field under nonsterile conditions in a few minutes, theoretically provides analgesia for any anatomic location, has no side effects, and no significant risks. It therefore offers the potential to be applied quickly on the battlefield without any of the limitations of opioids. We propose total joint replacement as a surrogate for battlefield trauma and here present a case report to demonstrate proof of concept.MethodsFollowing open total knee or hip arthroplasty under spinal anesthesia, two patients had an auricular neuromodulation device applied within the recovery room. Patients were discharged with the unit and contacted daily for 7 days.ResultsThe devices were each applied in under 3 minutes without difficulty, were well tolerated during use, and removed without complication at home on Day 5. During use, neither patient experienced pain while lying, sitting, or ambulating. Neither required analgesics other than scheduled celecoxib; and a single tablet (50 mg) of tramadol for one patient on postoperative Days 3 and 4 for pain while lowering herself to a seated position. On Days 6 and 7, both patients experienced an increase in pain, one of whom required around-the-clock tramadol.ConclusionAmbulatory postoperative percutaneous auricular neuromodulation is feasible. In these two cases, it appears to have markedly reduced pain scores and opioid requirements free of systemic side effects during the week following major orthopedic surgery. Considering the potential of this modality to treat trauma on the battlefield without systemic side effects, additional investigation appears warranted.Level of evidenceTherapeutic/care management; Level V.