Purpose/Hypothesis: The purpose of this study was to compare the clinical and radiologic outcomes of remnant-preserving PCL reconstruction using anatomic versus low tibial tunnels. We hypothesized that the outcomes of low tibial tunnel placement would be superior to those of anatomic tibial tunnel placement at the 2-year follow-up after remnant-preserving PCL reconstruction.

Study Design: Cohort study; Level of evidence, 3.

Methods: We retrospectively reviewed the data for patients who underwent remnant-preserving PCL reconstruction between March 2011 and January 2018 with a minimum follow-up of 2 years (N = 63). On the basis of the tibial tunnel position on postoperative computed tomography, the patients were divided into those with anatomic placement (group A; n = 31) and those with low tunnel placement (group L; n = 32). Clinical scores (International Knee Documentation Committee subjective score, Lysholm score, and Tegner activity level), range of motion, complications, and stability test outcomes at follow-up were compared between the 2 groups. Graft signal on 1-year follow-up magnetic resonance imaging scans was compared between 22 patients in group A and 17 patients in group L.

Results: There were no significant differences between groups regarding clinical scores or incidence of complications, no between-group differences in posterior drawer test results, and no side-to-side difference on Telos stress radiographs (5.2 ± 2.9 mm in group A vs 5.1 ± 2.8 mm in group L; P = .900). Postoperative 1-year follow-up magnetic resonance imaging scans showed excellent graft healing in both groups, with no significant difference between them.

HYPOTHESIS: Medial MAT would improve anteroposterior stability, and lateral MAT would improve rotational stability.

STUDY DESIGN: Cohort study; Level of evidence, 3.

METHOD: We retrospectively investigated 31 cases of MAT after a previous total or nearly total meniscectomy and ACL reconstruction between November 2008 and June 2017. Cases were divided into medial (16 cases) and lateral (15 cases) MAT groups. The patients were assessed preoperatively and at the 2-year follow-up.

RESULTS: In the medial MAT group, the International Knee Documentation Committee, Lysholm, Lysholm instability, and Tegner scores improved significantly at the 2-year follow-up, and there were also significant improvements in the anterior drawer, Lachman, and pivot-shift tests. In the lateral MAT group, the Lysholm and Tegner scores improved significantly at the 2-year follow-up, as had the anterior drawer and Lachman tests but not the pivot-shift test. The medial MAT group showed significant improvement in side-to-side difference on Telos stress radiographs, from 6.5 mm (preoperatively) to 3.6 mm (2-year follow-up) (P = .001), while the lateral MAT group showed no significant change. There was no progression of arthritis in either group.

METHODS: 63 patients who underwent remnant-preserving single-bundle PCL reconstruction between 2011 and 2018 with a minimum 2-year follow-up were retrospectively reviewed. Patients were divided into two groups according to the femoral tunnel position: group A (33 patients with anatomical femoral tunnel) and group H (30 patients with high femoral tunnels). The femoral tunnel was positioned at the center (group A) or upper margin (group H) of the remnant anterolateral bundle. The position of the femoral tunnel was evaluated using the grid method on three-dimensional computed tomography. Clinical and radiological outcomes and failure rates were compared between the groups at the 2-year follow-up.

METHODS: Two hundred and sixty three patients with 394 consecutive knees who underwent primary TKAs were retrospectively analysed in this study. Selective sequential multiple needle puncturing (MNP) was performed for medial ligament balancing when required. Constitutional alignment, which was determined using the Coronal Plane Alignment of the Knee (CPAK) classification, as well as preoperative and postoperative radiologic parameters was evaluated to identify factors which predicted the need for MNP.

RESULTS: One hundred and fifty eight (40.1%) knees required medial ligament balancing with MNP. Patients who required MNP during surgery had significantly more constitutional varus, more varus preoperative mechanical Hip-Knee-Ankle angle (mHKA), smaller preoperative medial proximal tibial angle (MPTA) and a larger change in mHKA and MPTA after surgery than those who did not. Patients with constitutional varus also had a higher incidence of having had MNP to both anterior and posterior superficial medial collateral ligament (sMCL) fibres. There was no significant difference in preoperative lateral distal femoral angle (LDFA), posterior tibial slope (PTS) and varus-valgus difference (VVD) between groups.

CONCLUSION: Ligament balancing using MNP was determined by constitutional alignment rather than medial soft tissue contracture. Patients with constitutional varus who had a larger medio-lateral gap difference in extension also had a higher incidence of having had MNP to both anterior and posterior sMCL fibres.

METHODS: This was a retrospective review of 270 consecutive patients (397 knees) who underwent primary TKA with an AR or PR system. Selection of implant size, mediolateral and anteroposterior alignment of the femoral component, as well as gaps were compared between groups.

RESULTS: In the AR group, more patients had femoral components which were upsized or downsized compared to those in the PR group (29.5% vs 12.0% respectively) and in patients who underwent bilateral TKA, 49.4% of those in the AR group had femur component size asymmetry. The AR group had better medio-lateral (ML) fit over the distal cutting surface area, smaller change in anterior offset but higher incidence of anterior notching when compared to the PR group. Posterior condylar offset (PCO) was restored in both groups and gap differences in flexion-extension and ML were comparable. There was also no difference in clinical scores and ROM between groups at 2-years follow-up.

METHODS: Postoperative CT scans of 200 propensity score-matched patients who underwent TKA with either an anatomic (ATC) or symmetrical tibia component (STC) were analyzed. Rotation was measured using four axes: surgical transepicondylar axis (sTEA), Berger's protocol, medio-lateral (ML) axis and posterior borders of the tibial plateau, while coverage was assessed by measuring fit and surface area. The relationship between coronal deformity, tibial torsion, rotation, and coverage was investigated.

RESULTS: Overall, STCs had more internal rotation when measured using the sTEA (-0.6° ± 3.5 vs 0.5° ± 3.6, p = 0.03), Berger's protocol (-21.6° ± 7.1 vs -17.9° ± 6.2, p = 0.000) and ML axes (2.9° ± 3.9 vs 8.1° ± 5.1, p = 0.000) compared to ATCs. STCs also had more posteromedial underhang (-3.3 mm ± 2.4 mm vs -1.7 mm ± 2.5 mm, p = 0.000) but smaller change in tibial torsion postoperatively (-18.4° ± 9.9° vs -13.1° ± 9.4°, p = 0.000). Tibial torsion was more pronounced in valgus than varus knees both preoperative (-25.4° ± 6.5° vs -20.2° ± 9.3°, p = 0.02) and postoperatively (-19.7° ± 7.2° vs -14.7° ± 10.3°, p = 0.04), but there was no difference in postoperative tibial torsion between ATCs and STCs in this subgroup.

METHODS: This is a cross-sectional study on 9553 adolescents (aged 12-15 years) from 8 Asian metropolitan cities (Tokyo, Hong Kong, Shanghai, Taipei, Bangkok, Kuala Lumpur, Seoul, and Singapore). Cardiorespiratory fitness was assessed by using a 15-m progressive aerobic capacity endurance run (PACER) test. The time spent on MVPA and watching television was assessed using the International Physical Activity Questionnaire-Short Form.