Does hip bone morphology differ depending on the presence of cam lesions in borderline developmental dysplasia of the hip?

Background: The purpose of this study was to divide patients with borderline developmental dysplasia of the hip (BDDH) into two groups according to the presence of Cam lesions, and compare radiographs related to bone morphology between them.

Methods: We retrospectively analyzed consecutive patients with BDDH who underwent hip arthroscopy (HA) or periacetabular osteotomy (PAO) at our institution between October 2013 and October 2019. The patients were classified into two groups according to the presence of Cam lesions.

Bone marrow mononuclear cell transplantation promotes bone healing via gap junction-mediated cell-cell interaction.

Aims: Bone marrow mononuclear cells (BM-MNCs) are a rich source of hematopoietic stem cells that have been widely used in experimental therapies for patients with various diseases, including fractures. Activation of angiogenesis is believed to be one of the major modes of action of BM-MNCs; however, the essential mechanism by which BM-MNCs activate angiogenesis remains elusive. This study aimed to demonstrate that BM-MNCs promote bone healing by enhancing angiogenesis through direct cell-to-cell interactions via gap junctions, in addition to a previously reported method.

A Restriction Boundary-Based Coronal Plane Alignment of the Knee (CPAK) Classification for Restricted Kinematic Alignment Total Knee Arthroplasty.

Background Coronal plane alignment of the knee (CPAK) classification was proposed as a means of understanding the knee phenotype in leg alignment and joint line obliquity (JLO). However, when it is adapted to restricted kinematic alignment total knee arthroplasty (rKA-TKA), the boundaries of CPAK and those of rKA-TKA phenotype are different. We therefore reappraise the boundary between the CPAK classification and restriction protocol and propose a restriction boundary-based CPAK (Rb-CPAK).

The Lateral Malleolus Is a Simple and Reliable Landmark that Can Be Used to Reliably Perform Restricted Kinematically Aligned Total Knee Arthroplasty-Anatomical and Clinical Studies in Japanese Population.

In restricted kinematic alignment total knee arthroplasty (TKA), bone resection is performed within a safe range to help protect against failure from extreme alignments. Patient-specific instrumentation, navigations, and robotics are often required for restricting bone cuts within a specified safe zone. We hypothesized that the lateral malleolus could be used as a landmark for restricting the tibial osteotomy using a mechanical jig.

Evaluation of morphological characteristics for incomplete discoid medial meniscus with an oversized posterior segment.

Background: A discoid medial meniscus is rare in comparison with a discoid lateral meniscus. We encountered a new type of incomplete discoid with an oversized posterior segment. Therefore, this study aimed to report cases of medial meniscus with an oversized posterior segment and analyze the morphological characteristics by comparing them to cases with a discoid medial meniscus and normal medial meniscus.

Approximately 41% of knees have a looser gap in full extension than in 20° flexion after Oxford unicompartmental arthroplasty.

Introduction: In Oxford unicompartmental knee arthroplasty (OUKA), the flexion and extension gaps should be adjusted to prevent mobile-bearing dislocation. The extension gap is recommended to be evaluated in the 20° flexion position to avoid underestimation due to tension of the posterior capsule. However, we have become aware of a looser gap in full extension than in 20° flexion in some instances.

Clinical Results of Dual SC Screw: A Mini-Sliding Hip Screw with an Anti-rotating Screw for Femoral Neck Fractures.

Backgroud: Dual SC screw (DSCS) is a unique concept internal fixation device consisting of a sliding screw and barrel assembly that enables compression force to be applied to the femoral neck fracture side. There are two types of barrels: a thread barrel and a plate barrel that has a one-holed side plate to prevent varus deformity. We report clinical results of the application of a DSCS with combined use of a thread barrel screw as an anti-rotational screw and a plate barrel screw as a compression hip screw.

Manipulation of Tibial Component to Ensure Avoidance of Bearing Separation from the Vertical Wall of Tibial Component in Oxford Unicompartmental Arthroplasty.

In Oxford unicompartmental knee arthroplasty, the relationship between the mobile bearing and the vertical wall of the tibial tray is important in preventing bearing dislocation. Separation of the bearing from the vertical wall can cause spinning of the bearing with an increased risk of subsequent dislocation. We report on intraoperative adjustment of the tibial tray performed to prevent the bearing from spinning.

A Novel Technique for Varus Tibial Cutting for Oxford Unicompartmental Knee Arthroplasty.

To reduce the stress on the medial tibial cortex and to decrease the risk of fracture, a varus cut of the tibia appears to be a reasonable alternative to the orthogonal cut by conventional methods. We present a new instrument and procedure, which enables a varus tibial cut for Oxford unicompartmental knee arthroplasty. We used a custom-made, slidable fixator instead of the standard fixator to set the extramedullary rod on the leg.