Osteochondritis Dissecans Lesion of the Trochlear Groove: A Case of Nonsurgical Management for a Rare Lesion

Osteochondritis dissecans (OCD) lesions are potential causes of knee pain in pediatric patients, with lesions most frequently found on the lateral and medial femoral condyles. This case discusses an OCD lesion of the trochlear groove, a rare location for OCD lesions, in an 11-year-old female athlete. The patient presents after several years of knee pain that had acutely worsened, and both X-ray and MRI demonstrated the lesion, with MRI confirming a stable lesion. While previous literature has leaned towards surgical management, this patient was successfully managed nonoperatively in a locked knee brace for 12 weeks. She then went through 4 weeks of physical therapy and a 4 week progression back into soccer activity with return to full activity in 5 months.

Performing a knee arthroscopy among patients with degenerative knee disease: one-third is potentially low value care

Purpose The purpose of this study was to assess in which proportion of patients with degenerative knee disease aged 50+ in whom a knee arthroscopy is performed, no valid surgical indication is reported in medical records, and to explore possible explanatory factors. Methods A retrospective study was conducted using administrative data from January to December 2016 in 13 orthopedic centers in the Netherlands. Medical records were selected from a random sample of 538 patients aged 50+ with degenerative knee disease in whom arthroscopy was performed, and reviewed on reported indications for the performed knee arthroscopy. Valid surgical indications were predefined based on clinical national guidelines and expert opinion (e.g., truly locked knee). A knee arthroscopy without a reported valid indication was considered potentially low value care. Multivariate logistic regression analysis was performed to assess whether age, diagnosis (“Arthrosis” versus “Meniscal lesion”), and type of care trajectory (initial or follow-up) were associated with performing a potentially low value knee arthroscopy. Results Of 26,991 patients with degenerative knee disease, 2556 (9.5%) underwent an arthroscopy in one of the participating orthopedic centers. Of 538 patients in whom an arthroscopy was performed, 65.1% had a valid indication reported in the medical record and 34.9% without a reported valid indication. From the patients without a valid indication, a joint patient–provider decision or patient request was reported as the main reason. Neither age [OR 1.013 (95% CI 0.984–1.043)], diagnosis [OR 0.998 (95% CI 0.886–1.124)] or type of care trajectory [OR 0.989 (95% CI 0.948–1.032)] were significantly associated with performing a potentially low value knee arthroscopy. Conclusions In a random sample of knee arthroscopies performed in 13 orthopedic centers in 2016, 65% had valid indications reported in the medical records but 35% were performed without a reported valid indication and, therefore, potentially low value care. Patient and/or surgeons preference may play a large role in the decision to perform an arthroscopy without a valid indication. Therefore, interventions should be developed to increase adherence to clinical guidelines by surgeons that target invalid indications for a knee arthroscopy to improve care. Level of evidence IV.

Inferior Patella Dislocation due to Impaction in the Femoral Trochlea

Acute inferior dislocation of the patella is a rare presentation in trauma and orthopaedics. Type II is caused by direct upward force on the inferior pole of the patella when the knee is flexed impacting the superior pole osteophyte into the intercondylar notch. Impaction in the femoral trochlea is rarely reported. A 92-year-old lady presented with locked knee held in 85° of flexion with an abnormal knee contour. Radiographs demonstrated that the upper pole of the patella was impacted in the femoral trochlea with a fracture of a superior pole osteophyte. The extensor mechanism was intact. Closed reduction is achieved under strong opioid pain relief. The patient returned to her baseline knee function within 6 weeks. Closed reduction of an inferior patellar dislocation in elderly patients is aided by superior pole osteophyte fracture and facilitates early mobilization, and avoidance of general anaesthesia.

Novel velocity estimation for symmetric and asymmetric self-paced treadmill training

Background Self-paced treadmills (SPT) can provide an engaging setting for gait rehabilitation by responding directly to the user’s intent to modulate the external environment and internal effort. They also can improve gait analyses by allowing scientists and clinicians to directly measure the effect of an intervention on walking velocity. Unfortunately, many common SPT algorithms are not suitable for individuals with gait impairment because they are designed for symmetric gait patterns. When the user’s gait is asymmetric due to paresis or if it contains large accelerations, the performance is diminished. Creating and validating an SPT that is suitable for asymmetric gait will improve our ability to study rehabilitation interventions in populations with gait impairment. The objective of this study was to test and validate a novel self-paced treadmill on both symmetric and asymmetric gait patterns and evaluate differences in gait kinematics, kinetics, and muscle activity between fixed-speed and self-paced treadmill walking. Methods We collected motion capture, ground reaction force data, and muscle activity from 6 muscles in the dominant leg during walking from 8 unimpaired subjects. In the baseline condition, the subjects walked at 3 fixed-speeds normalized to their leg length as Froude numbers. We developed a novel kinematic method for increasing the accuracy of the user’s estimated walking velocity and compared our method against other published algorithms at each speed. Afterward, subjects walked on the SPT while matching their walking speed to a given target velocity using visual feedback of the treadmill speed. We evaluated the SPT by measuring steady-state error and the number of steps to reach the desired speed. We split the gait cycle into 7 phases and compared the kinematic, kinetic, and muscle activity between the fixed speed and self-paced mode in each phase. Then, we validated the performance of the SPT for asymmetric gait by having subjects walk on the SPT while wearing a locked-knee brace set to 0° on the non-dominant leg. Results Our SPT enabled controlled walking for both symmetric and asymmetric gait patterns. Starting from rest, subjects were able to control the SPT to reach the targeted speeds using visual feedback in 13–21 steps. With the locked knee brace, subjects controlled the treadmill with substantial step length and step velocity asymmetry. One subject was able to execute a step-to gait and halt the treadmill on heel-strikes with the braced leg. Our kinematic correction for step-length outperformed the competing algorithms by significantly reducing the velocity estimation error at the tested velocities. The joint kinematics, joint torques, and muscle activity were generally similar between fixed-speed and self-paced walking. Statistically significant differences were found in 5 of 63 tests for joint kinematics, 2 of 63 tests for joint torques, and 9 of 126 tests for muscle activity. The differences that were statistically significant were not found across all speeds and were generally small enough to be of limited clinical relevance. Conclusions We present a validated method for implementing a self-paced treadmill for asymmetric and symmetric gaits. As a result of the increased accuracy of our estimation algorithm, our SPT produced controlled walking without including a position feedback controller, thereby reducing the influence of the controller on measurements of the user’s true walking speed. Our method relies only on a kinematic correction to step length and step time which can support transfer to systems outside of the laboratory for symmetric and asymmetric gaits in clinical populations.

INVESTIGATION OF THE EFFECTS OF PROSTHETIC KNEE CONDITION FOR INDIVIDUALS WITH TRANSFEMORAL AMPUTATION DURING ATTEMPTED RUNNING

BACKGROUND: A number of individuals with unilateral transfemoral amputation (TFA) run in a prosthesis with an unlocked prosthetic knee, while others choose to run with a locked prosthetic knee to increase stability. Research regarding running with an unlocked knee (UK) versus a locked knee (LK), with respect to energy efficiency, is limited and might be enhanced by characterization of the impact of knee condition on kinematics. OBJECTIVE: To investigate the effect of an UK versus LK on hip kinematics, energy efficiency, and running speed. METHODOLOGY: Five male novice runners with unilateral TFA completed one three-minute self-selected running speed (SSRS) trial and three peak speed trials per knee condition. Hip kinematics, energy efficiency, and running speed were compared between conditions. FINDINGS: Four of the five subjects exhibited a fast walk, rather than a consistent run. Hip flexion increased for all subjects and hip abduction decreased for four subjects during swing phase for the UK condition. Hip kinematic asymmetry was reduced for the UK condition in the sagittal plane for four individuals; hip kinematic asymmetry was also reduced in the frontal plane for the UK condition for three of these individuals. Mean energy efficiency was better for the UK condition (UK: 0.282 mLO2/kg/m, LK: 0.328 mLO2/kg/m). Peak running speed did not differ significantly between knee conditions (UK: 1.47 m/s, LK:1.32 m/s). CONCLUSIONS: For novice recreational runners with unilateral transfemoral amputation, the UK condition resulted in improved energy efficiency and enhanced kinematic symmetry, despite comparable peak speed relative to the LK condition. Therefore the UK condition may be advantageous for mid-range distance running. Layman's Abstract Runners with above-knee amputation may run with a prosthetic leg. Some runners prefer to run with their prosthetic knee unlocked, able to flex and extend, while others prefer to run with the prosthetic knee locked. The purpose of this study was to determine the effects of unlocked and locked knee conditions on hip motion, energy efficiency, and running speed during attempted running. Five male novice runners with an amputation above the knee attempted running for three-minutes at a comfortable speed, followed by three fast walks/sprints with the prosthetic knee unlocked and then locked. Most of the novice runners exhibited more symmetric hip motion while fast walking/running with an unlocked prosthetic knee. All our subjects were more energy efficient or exerted less energy with the unlocked prosthetic knee. Article PDF Link: https://jps.library.utoronto.ca/index.php/cpoj/article/view/34481/26590 How To Cite: Blakeley N., Silver-Thorn B., Cross J.A. Investigation of the effects of prosthetic knee condition for individuals with transfemoral amputation during attempted running. Canadian Prosthetics & Orthotics Journal. 2020; Volume 3, Issue 2, No.3. https://doi.org/10.33137/cpoj.v3i2.34481 Corresponding Author:Natalie Blakeley, Department of Biomedical Engineering, Marquette University, Milwaukee, USA. E-mail: [email protected]: https://orcid.org/0000-0002-2066-4096

Isolating the Energetic and Mechanical Consequences of Imposed Reductions in Ankle and Knee Flexion during Gait.

Background: Weakness of ankle and knee musculature following injury or disorder is associated with metabolically expensive gait compensations to enable limb support and advancement. However, neuromechanical coupling between the ankle and knee makes it difficult to discern independent roles of these joint dysfunctions on compensatory mechanics and metabolic penalties.Methods: We sought to determine relative impacts of ankle and knee impairment on compensatory gait strategies and energetic outcomes using an unimpaired cohort (N=15) with imposed unilateral joint range of motion restrictions as a surrogate for gait pathology. Participants walked on a dual-belt instrumented treadmill at 0.8 m s-1 using a 3D printed ankle stay and a knee brace to systematically limit ankle motion (locked-ank), knee motion (locked-knee), and ankle and knee motion (locked-a+k) simultaneously. In addition, participants walked without any ankle or knee bracing (control) and with knee bracing worn but unlocked (unlocked).Results: When ankle motion was restricted (locked-ank, locked-a+k) we observed decreased peak propulsion of the locked limb relative to unlocked. Reduced knee motion (locked-knee, locked-a+k) increased locked limb circumduction relative to the locked-ank condition through ipsilateral hip hiking. Interestingly, locked limb average positive hip power increased in the locked-ank condition but decreased in the locked-a+k and locked-knee conditions, suggesting that locking the knee impeded hip compensation. As expected, reduced ankle motion, either without (locked-ank) or in addition to knee restriction (locked-a+k) yielded significant increase in net metabolic rate when compared with unlocked. Furthermore, the relative increase in metabolic cost was significantly larger with locked-a+k when compared to locked-knee condition.Conclusions: Our methods allowed for the reproduction of asymmetric gait characteristics including reduced locked limb propulsion and increased circumduction. The metabolic consequences bolster the potential energetic benefit of targeting ankle function during rehabilitation.

About the Operator’s Gaits in the Passive Exoskeleton of the Lower Extremities when Using the Fixed Knee Mode

A dynamic model of motion in the sagittal plane of the passive exoskeleton of the lower extremities, integrated with a similar model of a human operator that determines the movement of the whole structure, is considered. The exoskeleton is designed to help the operator to move additional point load, placed in the "backpack" on the back. The design of the exoskeleton does not have active propulsive elements in the joints; it is endowed with only a semi-automatic system for locking or releasing the knee joints at certain stages of movement, which, however, affect the overall gait pattern. The energy costs and peak values of the control torques that the human operator applies in the process of moving the exoskeleton on certain types of regular, flat, single-support walkings are studied. The results obtained allow us to estimate the effectiveness of the mode of locking-releasing the knee joint used by such devices. Both cases of impact-free transitions to the locked knee mode and transitions accompanied by the occurrence of shock effects in a dynamic system were investigated. In mathematical modeling, the mass inertial characteristics of the human body were taken into account in accordance with the data adopted in anthropology.

Synovial chondromatosis masquerading as a para-meniscal cyst of the knee

Synovial chondromatosis and parameniscal cysts are well documented pathologies around the knee joint. We present an unusual presentation of synovial chondromatosis masquerading as a parameniscal cyst of the knee. The patient was an 82-year old gentleman seen in our knee clinic with painful swelling over medial aspect of the right knee, no history of injury and with symptoms of a locked knee. Clinico-radiological features were suggestive of a binary pathology of a meniscal tear and multi-locular cyst of the knee. An arthroscopic assisted open excision of the cystic lesion allowed clinical recovery with histological confirmation of benign synovial chondromatosis. We highlight the challenges in our case with the overlap of diagnostic features of both synovial and meniscal pathology with surgical management of this patient.