Purpose: To report the 2–5 year results of ACL reconstruction with doubled Tibialis anterior allograft.

Method: Seventy-three patients who underwent primary ACL reconstruction with doubled tibialis anterior allografts with minimum 2 year follow-up were included in the study. Patients were assessed via telephone interview using the Lysholm knee score, Tegner activity score, and the subjective International Knee Documentation Committee rating. In addition, they were asked if they had failure of the ACL requiring revision or any other procedures such as repeat arthroscopy for meniscal surgery/articular cartilage. Statistical analysis using levene’s test and the T-test was used to assess outcomes of patients according to age and sex.

Results: Sixty-four (88%) patients were available for follow-up. The mean age was 28.94 years (16–55). There were 33 males (51.6%) and 31 females (48.4%). The mean follow-up was 41.6 months (range 24–55 months). There were 2 (3%) complications, 1 patient suffered a DVT with subsequent PE, and 1 patient suffered a hardware problem. Four patients (6.3%) had failure of their graft and 6 patients (9%) required repeat arthroscopy. The mean Lysholm score was 91.75 (SD+/− 8.2), and the mean Tegner activity score was 5.4 (range 1–10). The mean IDKC was 88.94 (SD+/− 8.33). According to the IDKC score 58% of patients were rated as excellent, 27% as good, and 13% as fair and 2% as poor. There was no difference in outcome in patients under 30 compared to over 30 years. Males performed statistically better on the Lysholm and the IKDC scores (p 0.005 and 0.038 respectively) when compared to women.

Conclusion: ACL reconstruction with Allograft Tibialis anterior tendon provided good functional results with a low failure rate at 2–5 years. There was no statistical difference in outcome between Patients under 30 years and those above 30 years. Males performed better on the Lysholm and the IDKC questionnaires.

Purpose: Adults with knee osteoarthritis (OA) show biomechanical changes in gait which may be linked to the quadriceps weakness often associated with knee OA. The purpose of this study was to mimic the effect of quadriceps weakness by inducing fatigue to determine if this produced gait characteristics similar to those present in knee OA.

Method: Sixteen healthy, sedentary female subjects between the ages of 19 and 35 years participated. Subjects were randomly assigned to perform a quadriceps-fatiguing protocol using a CybexTM isokinetic dynamometer (n=9) or a resting control group (n=7). Gait was evaluated before and after the rest or the fatiguing protocol. Infrared and virtual markers were used to record the locations of 16 anatomical landmarks. Marker position was recorded using an Optotrak motion capture system. An AMTI force plate collected ground reaction forces. Joint kinematics and kinetics were calculated using standard techniques. Maximum, minimum and time to peak were calculated for knee flexion angle, and the flexion, adduction and rotation moments during stance. A 2-factor (group, pre-post) mixed model ANOVA was used to test main effects and interactions (alpha = 0.05). Post hoc Bonferroni testing (alphaadj=0.0125) was used to determine pair wise differences.

Results: The two groups were statistically similar at baseline (p> 0.05) in terms of their age, mass, height, strength, and self-selected walking velocity. The fatigue protocol resulted in a 49 ± 12% decrease in peak knee extensor torque. The statistical results showed that knee flexion and external rotation moments decreased, the time to peak knee flexion angle increased, and the minimum knee adduction moment increased from pre-test to post-test in the fatigued group (p< 0.05).

Conclusion: Induced quadriceps fatigue alters kinematic and kinetic gait parameters. The changes are consistent with the gait characteristics observed in patients with knee OA and imply a change in joint motion and loading. These results provide preliminary evidence of a direct link between quadriceps weakness and the mechanical environment of the knee joint. This may be useful in developing more specific management programs for knee OA.

Purpose: The purpose of this study was to determine what differences exist in the knee flexion, rotation and adduction moments and periarticular knee muscle activation patterns between subjects with medial compartment knee osteoarthritis (OA) and those with lateral compartment knee OA.

Method: Forty eight individuals with knee OA were studied. The group was divided into those with predominantly medial compartment involvement (38 subjects, age 63 ± 8 years) and those with lateral involvement (10 subjects, age 63 ± 9 years). Three-dimensional motion (Optotrak) and ground reaction force (AMTI) data were collected while the subjects walked at a self-selected velocity. The knee flexion, rotation and adduction moments, time normalized to the percentage of one gait cycle, were calculated using an inverse dynamics approach. Electromyograms (EMG) were also collected from the rectus femoris, vastus lateralis, vastus medialis, medial and lateral hamstrings, and medial and lateral gastrocnemius and normalized to maximum voluntary isometric contractions. Knee moments and waveforms for each muscle for one complete gait cycle were analyzed for group differences using principal component analysis (PCA) followed by Student’s t-tests (alpha-adj = 0.017) for the PCA scores.

Results: The two groups were statistical similar in terms of age, height, weight, and walking velocity (p> 0.05). PCA analysis revealed statistically significant differences (p< 0.017) in patterns for the knee adduction moment, medial gastrocnemius, and lateral hamstrings between the two groups.

Conclusion: As expected, there was a difference in the knee adduction moment between the two groups. What is novel is that the muscle activation patterns from the lateral site group are consistent with an attempt to unload that compartment. The results of this study provide evidence that biomechanical and neuromuscular differences do exist, depending on the OA site. This could have implications for developing site-specific conservative management approaches

Purpose: To test the null hypotheses that no significant differences in the net external knee adduction moment waveform captured during gait exist between neutral, toe in and toe out foot progression angle (FPA) modifications and between those with mild to moderate knee OA and asymptomatic control subjects.

Method: Ten patients with mild to moderate knee OA (age 45±7 years) and 16 asymptomatic control subjects (age 54±8 years) participated. Informed consent was obtained for all participants. Three-dimensional (3D) motion and ground reaction force data were recorded during gait. Five trials of each condition,

Self-selected walking (Neutral),

Results: There was a significant condition effect for FPA (Neutral=7o, Toe out=24o and Toe in=−9o) and a significant group effect for walking velocity (Asymptomatic=1.46m/s, Knee OA=1.27m/s). In both groups, a toe out FPA produced

a reduction in the overall knee adduction moment (captured by PC1),

Conclusion: The knee adduction moment is considered an indicator of medial tibio-femoral compressive loading. In this study, a toe out FPA modification during gait altered the characteristics of the knee adduction moment. A reduction in the overall magnitude, more specifically during late stance was found with the toe out gait modification. An increased initial stance peak magnitude was also found during toe out gait. This finding is novel, indicating that a greater peak medial compartment load is produced