Nonlaminotomy bilateral decompression: a novel approach in biportal endoscopic spine surgery for spinal stenosis.

Biportal endoscopic spine surgery (BESS) is an emerging technique for lumbar spinal stenosis. Previous BESS techniques involve partial osteotomy for access to spinal canal such as partial laminotomy, partial facetectomy, and other forms to access the spinal canal for decompression. However, approaches that include osteotomy can cause bone bleeding intraoperatively, leading to obscured vision, and may be at risk of postoperative facet arthritis and segmental instability due to damage to the posterior stability structure.

Early Surgical Repair of Medial Meniscus Posterior Root Tear Minimizes the Progression of Meniscal Extrusion: 2-Year Follow-up of Clinical and Radiographic Parameters After Arthroscopic Transtibial Pull-out Repair.

Background: Conflicting results have been reported concerning the progression of medial meniscal extrusion (MME) after arthroscopic transtibial pull-out repair of medial meniscus posterior root tear (MMRT), and no study has evaluated the relevant factors affecting the progression of MME.

Purpose: To (1) evaluate the subjective and objective surgical outcomes of arthroscopic transtibial pull-out repair of MMRT and (2) identify relevant factors affecting the progression of MME after surgery.

Study Design: Case-control study; Level of evidence, 3.

The effect of knee joint rotation in the sagittal and axial plane on the measurement accuracy of coronal alignment of the lower limb.

Background: Although the measurement of coronal alignment of the lower limb on conventional full-length weight-bearing anteroposterior (FLWAP) radiographs was reported to be influenced by the knee joint rotation, no comparative analysis was performed considering the effects of knee joint rotation on the sagittal and axial planes simultaneously using the three-dimensional images while taking into account the actual weight-bearing conditions. The aim of this study was to investigate the effect of knee joint rotation on the measurement accuracy of coronal alignment of the lower limb on the FLWAP radiograph.

Methods: Radiographic images of 90 consecutive patients (180 lower limbs) who took both the FLWAP radiograph and the EOS image were retrospectively reviewed.

Medial Meniscal Posterior Horn Tears Are Associated With Increased Posterior Tibial Slope: A Case-Control Study.

Background: While the medial meniscal posterior horn (MMPH) is reported to bear a considerable portion of overall load on the knee joint, including compressive and shear forces, no study has yet investigated the relationship between the MMPH and posterior tibial slope (PTS), which is a geometric factor associated with the shear force component in the presence of a compressive load in the knee joint.

Hypothesis/purpose: The purpose was to investigate the relationship between the PTS and MMPH tears in patients without ligamentous injury. It was hypothesized that the PTS is greater in patients with MMPH tears as compared with those without.

Do Rotation and Measurement Methods Affect Reliability of Anterior Cruciate Ligament Tunnel Position on 3D Reconstructed Computed Tomography?

Background: The literature has seldom investigated the anterior cruciate ligament (ACL) tunnel position while considering the effect of rotation of 3-dimensional computed tomography (3D-CT) images during measurements.

Hypothesis: We hypothesized that (1) measurement of the ACL tunnel position in the femur and tibia through use of 3D-CT is considerably influenced by rotation of the 3D model and (2) there exists a reliable measurement method for ACL tunnel position least affected by rotation.

Study Design: Controlled laboratory study.

The effect of medial open wedge high tibial osteotomy on the patellofemoral joint: comparative analysis according to the preexisting cartilage status.

Background: Although it has been known that medial open wedge high tibial osteotomy (MOWHTO) would adversely affect the patellofemoral joint, no previous study examined the surgical outcome of MOWHTO according to the preexisting cartilage status of the patellofemoral joint. The aim of this study was to investigate the effect of MOWHTO on the patellofemoral joint with regard to objective and subjective aspects according to the preexisting cartilage status.

Methods: Ninety-two patients who underwent MOWHTO and a following second-look arthroscopic assessment were included in this study.

The Effect of Cartilage Lesion in the Lateral Compartment of the Knee on the Surgical Outcome of Medial Open-Wedge High Tibial Osteotomy.

The aim of this study was to identify the effect of cartilage lesion in the lateral compartment of the knee on the surgical outcome of medial open-wedge high tibial osteotomy (MOWHTO). A total of 172 consecutive patients who underwent MOWHTO were evaluated retrospectively. Among the patients who underwent second-look arthroscopic assessment, 30 patients with lateral compartment cartilage lesion (group 1: ≥ grade 2 cartilage lesion according to the International Cartilage Repair Society [ICRS] grading system) and 64 patients with normal or near-normal lateral compartment cartilage (group 2: grade 0 or 1 cartilage lesion according to the ICRS grading system) were included in the analysis.