Gait differs between unilateral and bilateral knee osteoarthritis

Creaby MW, Bennell KL, Hunt MA. Gait differs between unilateral and bilateral knee osteoarthritis.ObjectivesTo compare walking biomechanics in the most painful leg, and symmetry in biomechanics between legs, in individuals with (1) unilateral pain and structural osteoarthritis (OA), (2) unilateral pain, but bilateral structural OA, and (3) bilateral pain and structural OA and in (4) an asymptomatic control group.DesignCohort study.SettingLaboratory based.ParticipantsParticipants with symptomatic and/or radiographic medial tibiofemoral OA in one or both knees (n=91), and asymptomatic control participants (n=31).InterventionsNot applicable.Main Outcome MeasureThe peak knee adduction moment, peak knee flexion moment, knee varus-valgus angle, peak knee flexion angle, toe-out, and trunk lean were computed from 3-dimensional analysis of walking at a self-selected speed.ResultsAfter controlling for walking speed, greater trunk lean toward the more painful knee and reduced flexion in the more painful knee were observed in all OA groups compared with the control group. Between-knee asymmetries indicating greater varus angle and a lower external flexion moment in the painful knee were present in those with unilateral pain and either unilateral or bilateral structural OA. Knee biomechanics were symmetrical in those with bilateral pain and structural OA and in the pain free control group.ConclusionsThe presence of pain unilaterally appears to be associated with asymmetries in knee biomechanics. Contrary to this, bilateral pain is associated with symmetry. This suggests that the symptomatic status of both knees should be considered when contemplating unilateral or bilateral biomechanical interventions for medial knee OA.     

Acute effects of bi-hemispheric transcranial direct current stimulation on the neuromuscular function of patients with chronic stroke: A randomized controlled study

BackgroundMuscle weakness in patients with chronic stroke is due to neuromuscular disorders such as muscle atrophy, loss of voluntary activation or weak muscle contractile properties which are majored by the imbalance of interhemispheric inhibition following stroke. In patients with chronic stroke, unilateral transcranial direct current stimulation improved the maximal isometric strength of paretic knee extensors, but bilateral transcranial direct current stimulation failed to improve concentric strength. This study aimed to assess if a bilateral current stimulation improves isometric maximal strength, voluntary activation and contractile properties of knee extensors in patients with chronic stroke.MethodsThirteen patients with chronic stroke and eight young healthy individuals participated in this randomized, simple-blinded, crossover study that included two experimental sessions: one with sham bilateral transcranial direct current stimulation and another with effective bilateral transcranial direct current stimulation (20 min, 2 mA). In the stroke patients, the anode was placed over the primary motor cortex of the affected hemisphere and the cathode over the contralateral primary motor cortex. In healthy participants, the brain side targeted by the anode and the cathode was randomly assigned. In each session, participants performed three assessments of strength, voluntary activation and contractile properties: before, during and after effective/sham bilateral transcranial direct current stimulation.FindingsBilateral transcranial direct current stimulation had no effect on any neuromuscular assessments in both groups (All P values > 0.05, partial eta-squares varied from 0.02 to 0.06).InterpretationA single session of bilateral transcranial direct current stimulation did not compensate muscular weakness of knee extensors in patients with chronic stroke.     

Immediate Efficacy of Laterally Wedged Insoles With Arch Support on Walking in Persons With Bilateral Medial Knee Osteoarthritis

ObjectiveTo investigate the immediate efficacy of laterally wedged insoles with arch support (LWAS) on gait in persons with bilateral medial knee osteoarthritis (OA).DesignA prospective case-control intervention study.SettingA gait laboratory with a 6-camera motion analysis system and 2 forceplates.ParticipantsFifteen women with bilateral medial knee OA and 15 healthy control subjects (N=30).InterventionsLWAS.Main Outcome MeasuresSubjective knee pain and objective biomechanical indices, namely, joint angles and moments in the frontal plane, frontal plane ground reaction force and lever arm, as well as medial/lateral center of mass and center of pressure during gait.ResultsWhen wearing the LWAS, knee pain during gait in persons with medial knee OA decreased (P=.01). Peak internal knee abductor moments were also reduced (P<.001) with increasing foot progression angles, laterally shifted center of pressure, and a shortened frontal plane lever arm (all P<.05). However, ankle invertor moments were increased (P<.05) when wearing the LWAS.ConclusionsAlthough peak internal knee abductor moment and knee pain were immediately reduced during gait when wearing the LWAS, increased ankle invertor moments were found, suggesting that the LWAS should be used with caution. Strengthening and monitoring the condition of the ankle invertor muscles may be necessary if the LWAS is used as an intervention for persons with bilateral medial knee OA.     

A patient-specific model of total knee arthroplasty to estimate patellar strain: A case study

BackgroundInappropriate patellar cut during total knee arthroplasty can lead to patellar complications due to increased bone strain. In this study, we evaluated patellar bone strain of a patient who had a deeper patellar cut than the recommended.MethodsA patient-specific model based on patient preoperative data was created. The model was decoupled into two levels: knee and patella. The knee model predicted kinematics and forces on the patella during squat movement. The patella model used these values to predict bone strain after total knee arthroplasty. Mechanical properties of the patellar bone were identified with micro-finite element modeling testing of cadaveric samples. The model was validated with a robotic knee simulator and postoperative X-rays. For this patient, we compared the deeper patellar cut depth to the recommended one, and evaluated patellar bone volume with octahedral shear strain above 1%.FindingsModel predictions were consistent with experimental measurements of the robotic knee simulator and postoperative X-rays. Compared to the recommended cut, the deeper cut increased the critical strain bone volume, but by less than 3% of total patellar volume.InterpretationWe thus conclude that the predicted increase in patellar strain should be within an acceptable range, since this patient had no complaints 8 months after surgery. This validated patient-specific model will later be used to address other questions on groups of patients, to eventually improve surgical planning and outcome of total knee arthroplasty.     

Rehabilitation of an osteochondral fracture using blood flow restricted exercise: A case review

ObjectivesIn this case review we report on a bodybuilder who used a practical model of blood flow restriction (BFR) training to successfully rehabilitate himself following an injury to his right knee.ResultsThe patient originally thought he had torn his meniscus however repeat radiographs and magnetic resonance imaging (MRI) confirmed an osteochondral fracture. The patient initially sought out a low load alternative to help with the maintenance of skeletal muscle mass. However, following rehabilitation with low load BFR resistance training, radiographs indicated that the bone had begun to heal suggesting that this type of training may also benefit bone.ConclusionsIn conclusion, this case review provides evidence that practical BFR using knee wraps can serve as an effective stimulus during rehabilitation from a knee injury.     

Reliability and Differences Between Sexes in Landing Mechanics when Performing the Lateral Bound Test

Background and PurposeAnterior cruciate ligament injuries are prevalent among the athletic population, imposing a heavy economic burden, and the risk of re-injury. Most current biomechanical screening tasks are performed in the sagittal plane, and there is a need for more screening tools that assess sports specific movements in the frontal plane. The purpose of this study was to determine the reliability of and examine differences between sexes in the performance of the Lateral Bound Test (LBT).Materials/MethodsEach subject performed three trials of a LBT which included jumping laterally from one leg over a hurdle and landing on the opposite leg. Two cameras were placed six feet from the landing marker. Maximum dynamic knee valgus using the frontal plane projection angle and knee flexion angle at initial contact and maximal knee flexion were measured upon landing leg using 2D video analysis software. Additionally, video of 10 individuals’ trials were analyzed twice with one week between the analyses to obtain intra-rater reliability while 12 participants were retested one week later to determine test-retest reliability.ResultsThirty healthy subjects, 16 males, 14 females participated. Intra-rater reliability was determined to be excellent for all variables (ICC>0.96). In contrast, the test-retest reliability had greater disparity. Test-retest reliability ranged from poor (ICC = 0.47) to excellent (ICC > 0.90). Significant differences existed between the sexes, including males being significantly taller, weighing more, and demonstrating greater bilateral dynamic knee valgus (p < 0.05). No significant differences existed between sexes for knee flexion angles.ConclusionThe new LBT had excellent intra-rater reliability for assessing dynamic knee valgus and initial and maximum knee flexion angle when performing a functional movement in the frontal plane. Furthermore, males landed with more dynamic knee valgus than females which is contradictory to what has been observed with functional screening tools performed in the sagittal plane.Level of Evidence3b (reliability study)     

Instrumented triple single-leg hop test: A validated method for ambulatory measurement of ankle and knee angles using inertial sensors

BackgroundHop tests are commonly used in clinical environments to measure function after sport-related knee injuries. Joint angle measurement during hopping is feasible in research-based environments equipped with motion-capture systems. Employing these systems in clinical research settings is inefficient, given the associated cost, preparation time, and expertise required to administer and interpret the findings. Therefore, this study aimed to introduce a wearable system comprising three inertial measurement units for 3D joint angular measurement during horizontal hop tests, validate the joint angles against a camera-based system, and evaluate its applicability in clinical research environments.MethodsTen able-bodied participants were outfitted with three inertial measurement units during triple single-leg hop trials. 3D knee and ankle angles were calculated using the strap-down integration method, and results were compared with camera-based joint angles. Additionally, knee and ankle range of motions (RoMs) during bilateral triple single-leg hop trials were compared for 22 participants with unilateral sport-related knee injuries and 10 uninjured participants.FindingsEstimated angles had root-mean-square and RoM error medians of less than 2.3 and 3.2 degrees for both joints, and correlation coefficients of above 0.92 when compared with the camera-based system, for all hop phases. Injured participants had smaller sagittal ankle RoM (P = .008) on their injured side, during the third hop. Concurrently, they demonstrated smaller knee RoM symmetry indices (P = .017) and injured knee sagittal RoMs (P = .009) compared to uninjured participants.InterpretationThe introduced system had appropriate accuracy to highlight post-injury modifications in hopping kinematics and reveal noteworthy differences in RoM of clinical samples.     

Higher patellofemoral compressive force does not affect anterior knee pain in anatomical bi-cruciate retaining total knee arthroplasty: In vivo prospective analysis of guided motion prosthesis

BackgroundThe purposes of the present study are 1) to measure intraoperative patellofemoral compressive force in patients undergoing anatomical bi-cruciate retaining total knee arthroplasty and to assess the relationship between intraoperative patellofemoral compressive force and patient reported outcome measurements and 2) to compare patellofemoral compressive force and patient reported outcome measurements among patients who underwent anatomical bi-cruciate retaining, cruciate retaining, and bi-cruciate stabilized total knee arthroplasty.MethodsTwenty-two patients with varus osteoarthritis of the knee who underwent anatomical bi-cruciate retaining total knee arthroplasty, 20 patients who underwent cruciate retaining total knee arthroplasty, and 24 patients who underwent bi-cruciate stabilized total knee arthroplasty were assessed. Patient reported outcome measurements were evaluated at 1.5 years after surgery.FindingsIntraoperative patellofemoral compressive force was significantly lower with anatomical bi-cruciate retaining total knee arthroplasty than with cruciate retaining total knee arthroplasty at 60° to 140° of flexion and nearly equivalent to intraoperative patellofemoral compressive force with bi-cruciate stabilized total knee arthroplasty at all knee flexion angles examined. With anatomical bi-cruciate retaining total knee arthroplasty, there were no significant correlations between intraoperative patellofemoral compressive force and almost all patient reported outcome measurements except for 2011 Knee Society Score expectations, which was positively correlated with patellofemoral compressive force at 10° of flexion, and Patella score quadriceps strength, which was negatively correlated with patellofemoral compressive force at 60° of flexion.InterpretationThere were no significant correlations between intraoperative patellofemoral compressive force and anterior knee pain after anatomical bi-cruciate retaining total knee arthroplasty.Evidence level: 3.     

Postoperative secondary aggravation of obstructive sleep apnea-hypopnea syndrome and hypoxemia with bilateral carotid body tumor: A case report

BACKGROUNDCarotid body tumor (CBT) is a chemoreceptor tumor located in the carotid body, accounting for approximately 0.22% of head and neck tumors. Surgery is the main treatment method for the disease.CASE SUMMARYWe reviewed the diagnosis and treatment of one patient who had postoperative secondary aggravation of obstructive sleep apnea–hypopnea syndrome (OSAHS) and hypoxia after surgical resection of bilateral CBTs. This patient was admitted, and relevant laboratory and imaging examinations, and polysomnography (PSG) were performed. After the definitive diagnosis, continuous positive airway pressure (CPAP) treatment was given, which achieved good efficacy.CONCLUSIONThis case suggested that aggravation of OSAHS and hypoxemia is possibly caused by the postoperative complications after bilateral CBTs, and diagnosis by PSG and CPAP treatment are helpful for this patient.     

Malignant peripheral nerve sheath tumor in an elderly patient with superficial spreading melanoma: A case report

BACKGROUNDMalignant peripheral nerve sheath tumor (MPNST) is a type of spindle cell sarcoma originating from the peripheral nerve, which usually results in the corresponding nerve sign on magnetic resonance imaging (MRI). Patients with MPNST may also have neurofibromatosis type 1.CASE SUMMARYA 78-year-old male was admitted to the hospital due to a tumor in his left knee. He had a previous history of superficial spreading melanoma on the left thigh. Color Doppler ultrasonography showed a hypoechoic mass in the subcutaneous soft tissues of the medial left knee with an abundant rich blood flow. Computed tomography scanning did not show obvious signs of bone destruction, but the skin adjacent to the tumor was slightly thickened. MRI examination revealed that the hypervascular lesion was well-circumscribed, lobulated, invaded the surrounding soft tissues and demonstrated heterogeneous enhancement but lacked an entering and exiting nerve sign. The MRI result indicated the invasiveness of the tumor. The patient underwent a left knee joint mass expanded resection and the first histopathological examination showed a MPNST with positive surgical margins. Therefore, the second extended resection was performed, and the patient had a good outcome in the short term.CONCLUSIONMRI is a useful technique for revealing the biological characteristics of MPNST and provides clinical support for evaluation of the surgical area before operation.     

Anesthetic management of bilateral pheochromocytoma resection in Von Hippel-Lindau syndrome: A case report

BACKGROUNDVon Hippel-Lindau disease (also known as VHL syndrome), is an autosomal dominant inherited disease. We describe a sporadic case of VHL syndrome where bilateral pheochromocytomas were unexpectedly identified. The patient underwent selective laparoscopic resections of the pheochromocytomas, and the anesthetic management during surgery was complex and challenging.CASE SUMMARYA 22-year-old man presented to our hospital to seek medical advice for infertility without any other complaints. The results of computed tomography and catecholamine levels in blood and urine demonstrated adrenal gland masses which were diagnosed as pheochromocytomas. Further examination confirmed that the patient also had VHL syndrome. After thorough preparation, the patient underwent selective laparoscopic resection of the pheochromocytomas and was discharged 10 d after surgery. We describe the process of perioperative anesthesia management in this patient undergoing pheochromocytoma resection. CONCLUSIONThis case summaries specific clinical traits and considerations in perioperative anesthesia management for VHL syndrome patients undergoing bilateral pheochromocytoma resection.     

Immediate effect of MWM adductor stretch,myofascial release,and conventional stretching in asymptomatic individuals with hip adductor tightness: A randomized controlled trial

BackgroundHip adductors are the group of muscles that stabilize the pelvis during weight transfer in lower limbs in a gait cycle. As the full range of motion is seldomly used, this group of muscles commonly go into tightness which in turn may be a predisposing factor in development of back pain and knee pain.Methods54 healthy individuals were selected after screening for bilateral hip adductor tightness by measuring hip abduction range of motion using goniometer. They were randomized to either mobilization with movement (MWM) adductor stretch, myofascial release, or conventional stretching group. All subjects were assessed pre and post intervention. Outcome measure used were hip abduction range of motion and bent knee fall out test.ResultsStatistically significant difference was noted between the experimental and the control group in terms of hip abduction range of motion and bent knee fall out test.ConclusionIntervention showed significant results in all three groups; however, MWM adductor stretch when used in conjunction with conventional stretching has proved to be more effective than myofascial release with foam roller and conventional stretching in increasing the abduction range of motion and bent knee fall out test.     

Delayed Spontaneous Bilateral Pneumothorax in a Previously Healthy Nonventilated COVID-19 Patient

BackgroundThe novel coronavirus disease 2019 (COVID-19) is a recent viral outbreak that has rapidly spread to multiple countries worldwide. Little is known about COVID-19 infection-related complications.Case ReportWe report a patient who developed spontaneous bilateral pneumothorax after a recent COVID-19 infection. To our knowledge, this is the first reported case of spontaneous bilateral pneumothorax in a patient with recent confirmed severe acute respiratory syndrome coronavirus-2 infection without any risk factors for pneumothorax and who had not received positive pressure ventilation.Why Should an Emergency Physician Be Aware of This?There may be a possible correlation between a recent COVID-19 infection and the development of spontaneous pneumothorax. The diagnosis of spontaneous pneumothorax should be considered in any patient with known or suspected recent COVID-19 infection who presents with new acute symptoms consistent with pneumothorax or sudden clinical deterioration.     

The effects of fatigue and anticipation on the mechanics of the knee during cutting in female athletes

BackgroundUnanticipated cutting tasks which do not allow for pre-planning of a movement have been reported to promote knee mechanics which may increase the risk of anterior cruciate ligament injury. Fatigue has also been reported to have similar effects. Athletes must often perform unanticipated tasks when they are fatigued. Previous studies have reported that the effects of anticipation become more prominent as an athlete progresses through a fatigue protocol. However, the protocols previously utilized may not mimic the demands of sports participation.MethodsThree-dimensional knee joint kinematics and kinetics were collected from 13 female athletes while they performed a run-and-cut task, before and after completion of an intermittent shuttle run. Trials were further divided (pre-planned, unanticipated) to assess the effects of anticipation.FindingsThere were no significant interactions between the effects of fatigue and anticipation for the peak knee angles or moments of the knee joint in any plane. Subjects did demonstrate a 68% increase in their peak knee abduction angles following completion of the intermittent shuttle run. Anticipation also had a significant effect on the mechanics of the knee in all planes. Most notably, there was a 23% increase in peak knee abduction angles and a 33% increase in the peak internal knee adduction moments.InterpretationBoth fatigue and anticipation promoted knee mechanics which are associated with an increased risk of knee injury. However, it does not appear that their effects combine when athletes are at a level of fatigue which is thought to reflect sports participation.     

Does central sensitization affect hyperalgesia after staged bilateral total knee arthroplasty? A randomized controlled trial

ObjectiveOsteoarthritis (OA) patients who undergo staged bilateral total knee arthroplasty (TKA) feel postoperative hyperalgesia in the second operated knee compared with the first knee. Ketamine is an important drug for central temporal summation and inhibition of secondary mechanical hyperalgesia. This study investigated whether central sensitization has a significant effect on hyperalgesia after consecutive operations.MethodsSeventy-one of 80 OA patients were randomly allocated to the ketamine or saline group. A bolus of ketamine (group K) or saline (group C) (0.5 mg/kg) was injected before induction and at an infusion rate of 3 µg/kg/minute during surgery. A visual analog scale (VAS) was used to assess resting and moving pain and opioid consumption on postoperative days 1, 2, and 3.ResultsThe difference in the VAS score between stages 1 and 2 (D_V2-V1) was higher in the ketamine compared with the saline group. D_V2-V1 for movement between the two groups was not inferior for all periods. Ketamine did not show a large analgesic effect on second-operated knee hyperalgesia in staged bilateral TKAs.ConclusionsWe could not confirm that hyperalgesia was only related to central sensitization with low-dose ketamine. Other factors might be also associated with the hyperexcitability of nociceptive stimuli.Clinical Research Information Service (CRIS) trial registry no: KCT0001481     

Immediate preoperative outcomes of pain neuroscience education for patients undergoing total knee arthroplasty: A case series

Background: Standard preoperative education for total knee arthroplasty (TKA) has been shown to have no effect on postoperative outcomes. This may be because such education programs fail to educate patients about pain. Pain neuroscience education (PNE) focuses on teaching people more about pain from a neurobiological and neurophysiological perspective. Design and setting: Case Series. Aim: To determine the immediate effects, if any, of providing PNE before TKA surgery on patient self-report measures. Participants: Twelve patients (female = 10) prior to TKA for knee osteoarthritis (OA). Intervention: Preoperative educational session by a physical therapist on the neuroscience of pain, accompanied by an evidence-based booklet. Main outcome measures: Comparison of pre- and post-PNE self-report measures on knee pain (NPRS), Pain Catastrophization Scale (PCS), fear of movement (TSK), and beliefs about TKA; as well as three physical performance measures – knee flexion active range of motion, 40 m self-paced walk, and pressure pain threshold (PPT). Results: Immediately following the PNE, patients had statistically significant lower TSK scores, increased PPT, and improved beliefs about their upcoming surgery. There were no significant changes in knee pain, function, or flexion active range of motion. Conclusions: Results appear to suggest that immediately after PNE, patients scheduled for TKA had statistically significant changes in fear of movement, decreased sensitivity to pain and positive shifts in their beliefs about their future knee surgery. Larger trials with control/comparison groups are warranted to determine the true effects of preoperative PNE for patients about to undergo TKA.