Objective. To conduct a meta-analysis of randomized controlled trials (RCTs) to compare knee arthroplasty with patient-specific instrumentation (PSI) with the conventional instrumentation (CI). Methods. RCTs were selected in PubMed and Embase from 2012 to 2018. Key data extracted included malalignment of mechanical axis, blood loss, surgical time, Oxford Knee Score (OKS), Knee Society Score (KSS), length of stay, and complications. Subgroup analysis was also performed regarding different PSI systems and different image processing methods. Results. 29 RCTs with 2487 knees were eligible for the meta-analysis. Results showed that PSI did not improve the alignment of the mechanical axis compared with CI, but MRI-based PSI and Visionaire-specific PSI decrease the risk of malalignment significantly (P=0.04 and P=0.003, respectively). PSI reduced operative time (P=0.03) and blood loss (P=0.002) and improve the KSS (P=0.02) compared with CI, but for CT-based PSI, the difference of operative time becomes insignificant. PSI showed no significant difference with CI regarding risk of complication, length of stay in hospital, and functional outcomes of OKS. Conclusion. PSI reduced the blood loss and improved KSS. MRI-based PSI reduced operative time and risk of malalignment of mechanical axis compared with CT-based PSI. Moreover, Visionaire-specific PSI achieves better alignment result of the mechanical axis than other systems.

Purpose: To conduct a systematic review and meta-analysis comparing the surgical techniques, clinical outcomes, rates of revision and conversion to arthroplasty and complications between a repaired and unrepaired capsulotomy after hip arthroscopy. Methods: A search of the PubMed, Embase and Google Scholar databases was performed to identify comparative articles published prior to 10 July 2019 that reported the capsule management strategy and clinical outcomes after hip arthroscopy. A narrative analysis and meta-analysis were performed to integrate and compare the results of the 2 groups. Results: 12 comparative studies ( n = 1185 hips) with an average (methodological index for non-randomized studies) MINORS score of 17.45 ± 2.02 were identified for analysis, of which 5 were included in the meta-analysis. The pre- to postoperative improvements in the modified Harris Hip Score (mHHS), Hip Outcome Score–Sport-Specific Subscale (HOS-SS), and Hip Outcome Score–Activities of Daily Living (HOS-ADL) revealed no significant differences between the repaired and unrepaired groups ( p = 0.40, 0.26 and 0.61, respectively). The risk ratio of the revision rate for the 2 groups was 0.66 ( p = 0.21). Evaluation of the MRI scans and the rate of heterotopic ossification also showed no significant differences. The most preferred capsulotomy techniques were interportal and T-shape. No postoperative hip instability was reported in any of the 12 studies. Conclusion: The currently published evidence is still not strong enough to confirm the superiority of repairing the capsule after hip arthroscopy; hence, routine repair of the capsule during surgery cannot be suggested.

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Background: The “killer turn” effect after posterior cruciate ligament (PCL) reconstruction is a problem that can lead to graft laxity or failure. Solutions for this situation are currently lacking. Purpose: To evaluate the clinical outcomes of a modified procedure for PCL reconstruction and quantify the killer turn using 3-dimensional (3D) computed tomography (CT). Study design: Case series; Level of evidence, 4. Methods: A total of 15 patients underwent modified PCL reconstruction with the tibial aperture below the center of the PCL footprint. Next, 2 virtual tibial tunnels with anatomic and proximal tibial apertures were created on 3D CT. All patients were assessed according to the Lysholm score, International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form, Tegner score, side-to-side difference (SSD) in tibial posterior translation using stress radiography, and 3D gait analysis. Results: The modified tibial tunnel showed 2 significantly gentler turns (superior, 109.87° ± 10.12°; inferior, 151.25° ± 9.07°) compared with those reconstructed with anatomic (91.33° ± 7.28°; P < .001 for both comparisons) and proximal (99° ± 7.92°; P = .023 and P < .001, respectively) tibial apertures. The distance from the footprint to the tibial aperture was 16.49 ± 3.73 mm. All patient-reported outcome scores (mean ± SD) improved from pre- to postoperatively: Lysholm score, from 46.4 ± 18.87 to 83.47 ± 10.54 ( P < .001); Tegner score, from 2.47 ± 1.85 to 6.07 ± 1.58 ( P < .001); IKDC sports activities score, from 19 ± 9.90 to 33.07 ± 5.35 ( P < .001); and IKDC knee symptoms score, from 17.87 ± 6.31 to 25.67 ± 3.66 ( P < .001). The mean SSD improved from 9.15 ± 2.27 mm preoperatively to 4.20 ± 2.31 mm postoperatively ( P < .001). The reconstructed knee showed significantly more adduction (by 1.642°), less flexion (by 1.285°), and more lateral translation (by 0.279 mm) than that of the intact knee ( P < .001 for all). Conclusion: Lowering the tibial aperture during PCL reconstruction reduced the killer turn, and the clinical outcomes remained satisfactory. However, SSD and clinical outcomes were similar to those of previously described techniques using an anatomic tibial tunnel.