Clinical Orthopaedics and Related Research, Sep 25, 2013
Unloading knee braces often are used aftertibiofemoral articular cartilage repair. However, theex... more Unloading knee braces often are used aftertibiofemoral articular cartilage repair. However, theexperimental basis for their use in patients with normaltibiofemoral alignment such as those undergoing cartilagerepair is lacking.
Progressive weight-bearing is recommended following autologous chondrocyte implantation. This wei... more Progressive weight-bearing is recommended following autologous chondrocyte implantation. This weight-bearing program assumes that increasing external loads experienced at the foot during gait are closely related to external-knee-joint moments. We investigated this relationship, and examined other variables that may contribute to knee-joint kinetics of which the clinician can modify using practical instruction within a clinical setting. Gait analysis was performed in 51 patients following autologous chondrocyte implantation, during various partial- and full-weight-bearing conditions. The contribution of ground-reaction force, kinematic and spatio-temporal gait parameters to external-knee moments was investigated within weight-bearing levels less than 60%, between 60% and 90% and more than 90% of individual body weight. There was no association between peak-ground-reaction force and the knee-adduction moment within the 60-90% and more than 90% weight-bearing conditions, nor the peak-knee-flexion moment at less than 60% weight-bearing. Peak-ground-reaction force accounted for no more than 21.4% and 18.6% of the variance in the knee-adduction and flexion moments, respectively, within any weight-bearing condition, while the combination of peak-ground-reaction force, kinematic and spatio-temporal parameters investigated accounted for no more than 39.7% and 52.2%, respectively. Foot-progression angle and knee-flexion during weight acceptance accounted for a significant (P<0.05) portion of the variance in external-knee moments, particularly at higher levels of weight-bearing. A large amount of variance in knee moments may be attributed to variables other than external loads, some of which can be modified by the clinician. Clinically, this is important for any therapist implementing progressive weight-bearing protocols.
Matrix-induced autologous chondrocyte implantation is a technique for repairing articular cartila... more Matrix-induced autologous chondrocyte implantation is a technique for repairing articular cartilage defects in the knee. Despite reported improvements in pain, little is known about the recovery of knee biomechanics during walking gait. A randomized controlled study design was used to investigate knee biomechanics during gait in 61 patients following matrix-induced autologous chondrocyte implantation, in conjunction with either 'accelerated' or…
To determine the effectiveness of ‘accelerated’ compared to ‘traditional’ post-operative load bea... more To determine the effectiveness of ‘accelerated’ compared to ‘traditional’ post-operative load bearing rehabilitation protocols following matrix-induced autologous chondrocyte implantation (MACI).A randomized controlled study design was used to investigate clinical, biomechanical and radiographic assessment at 3 months post-surgery in 62 patients following MACI to the medial or lateral femoral condyle. Both rehabilitation interventions sought to protect the implant for an initial period, then incrementally increase load bearing. Under the ‘accelerated’ protocol, patients reached full weight bearing at 8 weeks post-surgery, compared to 11 weeks for the ‘traditional’ group.Patients in the ‘accelerated’ group achieved greater 6 min walk distances and daily activity levels as measured by accelerometry (P < 0.05) compared to the ‘traditional’ group. Furthermore, the ‘accelerated’ group reported significantly better improvement in knee pain at 12 weeks as indicated by the Knee Injury and Osteoarthritis Outcome Score (P < 0.05), and regardless of the rehabilitation protocol employed, no patient suffered any adverse effect to the implant as assessed by magnetic resonance imaging at 3 months. Comparison of each rehabilitation group with an unaffected control group revealed a significant difference in peak knee adduction and flexion moments for the traditional group (P < 0.05). However, there was no difference for accelerated patients (P > 0.05), which may demonstrate a faster return to knee loading patterns typically observed in unaffected subjects.The ‘accelerated’ load bearing approach that reduced the length of time spent ambulating on crutches resulted in reduced knee pain, improved function, no graft complications and may speed up the recovery of normal gait function. Patient follow-up to at least 24 months would be required to observe longer-term graft outcomes.
To determine how unanticipated performance of cutting maneuvers in sport affects the external loa... more To determine how unanticipated performance of cutting maneuvers in sport affects the external loads applied to the knee joint and the potential risk for ligament injury. A 50-Hz VICON motion analysis system was used to determine the lower limb kinematics of 11 healthy male subjects during running and cutting tasks performed under preplanned (PP) and unanticipated (UN) conditions. Subjects performed the UN tasks in response to a light stimulus on a target board. A kinematic model was then used in conjunction with force place data to calculate the three-dimensional loads at the knee joint. External flexion/extension moments at the knee joint were similar between PP and UN conditions; however, the varus/valgus and internal/external rotation moments during the UN cutting tasks were up to twice the magnitude of the moments measured during the PP condition. Cutting maneuvers performed without adequate planning may increase the risk of noncontact knee ligament injury due to the increased external varus/valgus and internal/external rotation moments applied to the knee. These results are probably due to the small amount of time to make appropriate postural adjustments before performance of the task, such as the position of the foot on the ground relative to the body center of mass. Subsequently, training for the game situation should involve drills that familiarize players with making unanticipated changes of direction. Practice sessions should also incorporate plyometrics and should focus on better interpretation of visual cues to increase the time available to preplan a movement.
Clinical Orthopaedics and Related Research, Sep 25, 2013
Unloading knee braces often are used aftertibiofemoral articular cartilage repair. However, theex... more Unloading knee braces often are used aftertibiofemoral articular cartilage repair. However, theexperimental basis for their use in patients with normaltibiofemoral alignment such as those undergoing cartilagerepair is lacking.
Progressive weight-bearing is recommended following autologous chondrocyte implantation. This wei... more Progressive weight-bearing is recommended following autologous chondrocyte implantation. This weight-bearing program assumes that increasing external loads experienced at the foot during gait are closely related to external-knee-joint moments. We investigated this relationship, and examined other variables that may contribute to knee-joint kinetics of which the clinician can modify using practical instruction within a clinical setting. Gait analysis was performed in 51 patients following autologous chondrocyte implantation, during various partial- and full-weight-bearing conditions. The contribution of ground-reaction force, kinematic and spatio-temporal gait parameters to external-knee moments was investigated within weight-bearing levels less than 60%, between 60% and 90% and more than 90% of individual body weight. There was no association between peak-ground-reaction force and the knee-adduction moment within the 60-90% and more than 90% weight-bearing conditions, nor the peak-knee-flexion moment at less than 60% weight-bearing. Peak-ground-reaction force accounted for no more than 21.4% and 18.6% of the variance in the knee-adduction and flexion moments, respectively, within any weight-bearing condition, while the combination of peak-ground-reaction force, kinematic and spatio-temporal parameters investigated accounted for no more than 39.7% and 52.2%, respectively. Foot-progression angle and knee-flexion during weight acceptance accounted for a significant (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05) portion of the variance in external-knee moments, particularly at higher levels of weight-bearing. A large amount of variance in knee moments may be attributed to variables other than external loads, some of which can be modified by the clinician. Clinically, this is important for any therapist implementing progressive weight-bearing protocols.
Matrix-induced autologous chondrocyte implantation is a technique for repairing articular cartila... more Matrix-induced autologous chondrocyte implantation is a technique for repairing articular cartilage defects in the knee. Despite reported improvements in pain, little is known about the recovery of knee biomechanics during walking gait. A randomized controlled study design was used to investigate knee biomechanics during gait in 61 patients following matrix-induced autologous chondrocyte implantation, in conjunction with either &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;accelerated&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; or…
To determine the effectiveness of ‘accelerated’ compared to ‘traditional’ post-operative load bea... more To determine the effectiveness of ‘accelerated’ compared to ‘traditional’ post-operative load bearing rehabilitation protocols following matrix-induced autologous chondrocyte implantation (MACI).A randomized controlled study design was used to investigate clinical, biomechanical and radiographic assessment at 3 months post-surgery in 62 patients following MACI to the medial or lateral femoral condyle. Both rehabilitation interventions sought to protect the implant for an initial period, then incrementally increase load bearing. Under the ‘accelerated’ protocol, patients reached full weight bearing at 8 weeks post-surgery, compared to 11 weeks for the ‘traditional’ group.Patients in the ‘accelerated’ group achieved greater 6 min walk distances and daily activity levels as measured by accelerometry (P < 0.05) compared to the ‘traditional’ group. Furthermore, the ‘accelerated’ group reported significantly better improvement in knee pain at 12 weeks as indicated by the Knee Injury and Osteoarthritis Outcome Score (P < 0.05), and regardless of the rehabilitation protocol employed, no patient suffered any adverse effect to the implant as assessed by magnetic resonance imaging at 3 months. Comparison of each rehabilitation group with an unaffected control group revealed a significant difference in peak knee adduction and flexion moments for the traditional group (P < 0.05). However, there was no difference for accelerated patients (P > 0.05), which may demonstrate a faster return to knee loading patterns typically observed in unaffected subjects.The ‘accelerated’ load bearing approach that reduced the length of time spent ambulating on crutches resulted in reduced knee pain, improved function, no graft complications and may speed up the recovery of normal gait function. Patient follow-up to at least 24 months would be required to observe longer-term graft outcomes.
To determine how unanticipated performance of cutting maneuvers in sport affects the external loa... more To determine how unanticipated performance of cutting maneuvers in sport affects the external loads applied to the knee joint and the potential risk for ligament injury. A 50-Hz VICON motion analysis system was used to determine the lower limb kinematics of 11 healthy male subjects during running and cutting tasks performed under preplanned (PP) and unanticipated (UN) conditions. Subjects performed the UN tasks in response to a light stimulus on a target board. A kinematic model was then used in conjunction with force place data to calculate the three-dimensional loads at the knee joint. External flexion/extension moments at the knee joint were similar between PP and UN conditions; however, the varus/valgus and internal/external rotation moments during the UN cutting tasks were up to twice the magnitude of the moments measured during the PP condition. Cutting maneuvers performed without adequate planning may increase the risk of noncontact knee ligament injury due to the increased external varus/valgus and internal/external rotation moments applied to the knee. These results are probably due to the small amount of time to make appropriate postural adjustments before performance of the task, such as the position of the foot on the ground relative to the body center of mass. Subsequently, training for the game situation should involve drills that familiarize players with making unanticipated changes of direction. Practice sessions should also incorporate plyometrics and should focus on better interpretation of visual cues to increase the time available to preplan a movement.
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