Clinical Orthopaedics and Related Research ®

A Publication of The Association of Bone and Joint Surgeons ®

Knee 450 articles


Intraoperative Joint Gaps Affect Postoperative Range of Motion in TKAs With Posterior-stabilized Prostheses

Toshifumi Watanabe MD, PhD, Takeshi Muneta MD, PhD, Ichiro Sekiya MD, PhD, Scott A. Banks PhD

Joint gaps and mediolateral (ML) soft tissue balance have long been known to affect clinical scores and patient function after TKA, but the relationship between gaps and soft tissue balance remain poorly defined. If specific relationships exist between soft tissue tension and patient function, then objective targets could be established to assist surgeons in achieving more consistent postoperative knee function.

Lateral Soft Tissue Laxity Increases but Medial Laxity Does Not Contract With Varus Deformity in Total Knee Arthroplasty

Shigetoshi Okamoto MD, Ken Okazaki MD, PhD, Hiroaki Mitsuyasu MD, Shuichi Matsuda MD, PhD, Yukihide Iwamoto MD, PhD

In TKA, soft tissue balance (the joint gap) depends on the amount of resected bone and soft tissue release. Some studies report preoperative bony deformity correlates with soft tissue balance evaluated intraoperatively and that the medial tissues are contracted with varus deformity. However, these studies did not take into account the amount of resected bone and did not describe whether the soft tissue was tight or loose. Therefore, it remains unclear whether in varus deformity the soft tissues on the medial side are contracted.

Is there a Valid and Reliable Assessment of Diagnostic Knee Arthroscopy Skill?

Tyson Olson BS, Ryan Koehler BS, Aaron Butler BS, Simon Amsdell MD, Gregg Nicandri MD

The Basic Arthroscopic Knee Skill Scoring System (BAKSSS) has construct validity as an objective measure of arthroscopic proficiency when used to assess the task of performing arthroscopic meniscectomies on cadaver knees. The reliability of this instrument is unknown.

The Vector of Quadriceps Pull is Directed From the Patella to the Femoral Neck

Osamu Tanifuji MD, John David Blaha MD, Shin Kai PhD

The quadriceps is the primary extensor of the knee. Its vector, which is perpendicular to the flexion axis of the knee, is important in understanding knee function and properly aligning total knee components. Three-dimensional (3-D) imaging enables evaluation using a 3-D model of each quadriceps component.

Case Report: Failure of Rotating-hinge Total Knee Prosthesis by Disengagement of the Hinge-post Extension

Debdut Biswas MD, Bryan Haughom MD, Robert E. Mayle MD, Craig J. Della Valle MD

Although modern-generation rotating-hinge knee implants have been modified to mitigate earlier complications related to aseptic loosening with these devices in revision TKAs, there are few, if any, reports of failure related to the hinge mechanism in these prostheses.

Development and Validation of a New Evaluation System for Patients With a Floor-based Lifestyle: The Korean Knee Score

Jin Goo Kim MD, PhD, Jeong Ku Ha MD, Seung Beom Han MD, PhD, Tae Kyun Kim MD, PhD, Myung Chul Lee MD, PhD

Patients’ perspectives on functioning and health have been increasingly recognized as a crucial aspect of health care, leading to the use of patient-reported instruments for outcome assessment. However, available instruments for total knee arthroplasty do not reflect the floor-based lifestyle with high knee flexion of eastern Asia.

Obesity Does Not Imply Poor Outcomes in Asians after Total Knee Arthroplasty

Hamid Rahmatullah Bin Abd Razak MBBS, Hwei Chi Chong BSc, Andrew Hwee Chye Tan MBBS, FRCS (Orth)

In Asia, obesity has reached epidemic proportions and physicians are likely to face a burden of obesity-related disorders, of which osteoarthritis of the knee is one. However, it is unclear whether obesity affects improvement of conventional TKAs in Asian patients.

The Intact Posterior Cruciate Ligament Not Only Controls Posterior Displacement but Also Maintains the Flexion Gap

Yoshio Matsui PhD, MD, Yoshinori Kadoya PhD, MD, Shuji Horibe PhD, MD

The PCL is a strong stabilizer of the knee and provides posterior stability to the tibia. However, sagittal alignment of the PCL with the knee at 90° flexion suggests the PCL might play a role not only in posterior stabilization but also in maintaining the flexion gap.

Distal Femur Rotation Relates to Joint Obliquity in ACL-deficient Chinese


The lower limb osteometry of Chinese differs from that of whites. The joint line of the knee in the coronal plane in Chinese is more medially inclined and the posterior condylar angle of the distal femur in the axial plane is larger. However, it is unclear whether there is any direct association between the coronal plane and axial plane osteometry.

High-flexion Prosthesis Improves Function of TKA in Asian Patients Without Decreasing Early Survivorship

Bum-Sik Lee MD, Jong-Won Chung MD, Jong-Min Kim MD, Kyung-Ah Kim PhD, Seong-Il Bin MD

Two previous studies recently raised the possibility of a high risk of early femoral components loosening with high-flexion (HF) prostheses in Asian populations and suggested that the high failure rate of HF TKAs was associated with HF ability. However, these findings are controversial given other studies reporting a low incidence of aseptic failures in HF prostheses.