Purpose To systematically review the literature for radiographic prevalence of osteoarthritis (OA) at a minimum of 10 years following anterior cruciate ligament (ACL) reconstruction (ACLR) with anatomic vs. non‐anatomic techniques. It was hypothesized that the incidence of OA at long‐term follow‐up would be lower following anatomic compared to non‐anatomic ACLR. Methods A systematic review was performed by searching PubMed, MEDLINE, EMBASE, and the Cochrane Library, for studies reporting OA prevalence by radiographic classification scales at a minimum of 10 years following ACLR with autograft. Studies were categorized as anatomic if they met or exceeded a score of 8 according the Anatomic ACL Reconstruction Scoring Checklist (AARSC), while those with a score less than 8 were categorized as non‐anatomic/non‐specified. Secondary outcomes included graft failure and measures of knee stability (KT‐1000, Pivot Shift) and functional outcomes [Lysholm, Tegner, subjective and objective International Knee Documentation Committee (IKDC) scores]. OA prevalence on all radiographic scales was recorded and adapted to a normalized scale. Results Twenty‐six studies were included, of which 5 achieved a score of 8 on the AARSC. Using a normalized OA classification scale, 87 of 375 patients (23.2%) had diagnosed OA at a mean follow‐up of 15.3 years after anatomic ACLR and 744 of 1696 patients (43.9%) had OA at mean follow‐up of 15.9 years after non‐anatomic/non‐specified ACLR. The AARSC scores were 9.2 ± 1.3 for anatomic ACLR and 5.1 ± 1.1 for non‐anatomic/non‐specified ACLR. Secondary outcomes were relatively similar between techniques but inconsistently reported. Conclusions This study showed that anatomic ACLR, defined as an AARSC score ≥ 8, was associated with lower OA prevalence at long‐term follow‐up. Additional studies reporting long‐term outcomes following anatomic ACLR are needed, as high‐level studies of anatomic ACLR are lacking. The AARSC is a valuable resource in performing and evaluating anatomic ACLR. Anatomic ACLR, as defined by the AARSC, may reduce the long‐term risk of post‐traumatic OA following ACL injury to a greater extent than non‐anatomic ACLR. Level of evidence IV.

BACKGROUND Intracortical microelectrode arrays have enabled people with tetraplegia to use a brain–computer interface for reaching and grasping. In order to restore dexterous movements, it will be necessary to control individual fingers. OBJECTIVE To predict which finger a participant with hand paralysis was attempting to move using intracortical data recorded from the motor cortex. METHODS A 31-yr-old man with a C5/6 ASIA B spinal cord injury was implanted with 2 88-channel microelectrode arrays in left motor cortex. Across 3 d, the participant observed a virtual hand flex in each finger while neural firing rates were recorded. A 6-class linear discriminant analysis (LDA) classifier, with 10 × 10-fold cross-validation, was used to predict which finger movement was being performed (flexion/extension of all 5 digits and adduction/abduction of the thumb). RESULTS The mean overall classification accuracy was 67% (range: 65%-76%, chance: 17%), which occurred at an average of 560 ms (range: 420-780 ms) after movement onset. Individually, thumb flexion and thumb adduction were classified with the highest accuracies at 92% and 93%, respectively. The index, middle, ring, and little achieved an accuracy of 65%, 59%, 43%, and 56%, respectively, and, when incorrectly classified, were typically marked as an adjacent finger. The classification accuracies were reflected in a low-dimensional projection of the neural data into LDA space, where the thumb-related movements were most separable from the finger movements. CONCLUSION Classification of intention to move individual fingers was accurately predicted by intracortical recordings from a human participant with the thumb being particularly independent.

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