Radiographic assessment of leg alignment and grading of knee osteoarthritis: A critical review

Automated Radiographic Measurements of Knee Osteoarthritis

OBJECTIVE

Herewith, we report the development of Orthopedic Digital Image Analysis (ODIA) software that is developed to obtain quantitative measurements of knee osteoarthritis (OA) radiographs automatically. Manual segmentation and measurement of OA parameters currently hamper large-cohort analyses, and therefore, automated and reproducible methods are a valuable addition in OA research. This study aims to test the automated ODIA measurements and compare them with available manual Knee Imaging Digital Analysis (KIDA) measurements as comparison.

DESIGN

This study included data from the CHECK (Cohort Hip and Cohort Knee) initiative, a prospective multicentre cohort study in the Netherlands with 1,002 participants. Knee radiographs obtained at baseline of the CHECK cohort were included and mean medial/lateral joint space width (JSW), minimal JSW, joint line convergence angle (JLCA), eminence heights, and subchondral bone intensities were compared between ODIA and KIDA.

RESULTS

Of the potential 2,004 radiographs, 1,743 were included for analyses. Poor intraclass correlation coefficients (ICCs) were reported for the JLCA (0.422) and minimal JSW (0.299). The mean medial and lateral JSW, eminence height, and subchondral bone intensities reported a moderate to good ICC (0.7 or higher). Discrepancies in JLCA and minimal JSW between the 2 methods were mostly a problem in the lateral tibia plateau.

CONCLUSIONS

The current ODIA tool provides important measurements of OA parameters in an automated manner from standard radiographs of the knee. Given the automated and computerized methodology that has very high reproducibility, ODIA is suitable for large epidemiological cohorts with various follow-up time points to investigate structural progression, such as CHECK or the Osteoarthritis Initiative (OAI).

Management Considerations for Unicompartmental Osteoarthritis in Athletic Populations: A Review of the Literature

Unicompartmental osteoarthritis in the young athlete poses a challenge for both patients and providers. Coronal plane malalignment is frequently a concomitant finding that adds to the complexity of management. Military surgeons are presented unique challenges, in that they must consider optimal joint-preservation methods while returning patients to a high-demand occupational function. Management options range from lifestyle changes to surgical interventions. We present a concise review of the available literature on this subject, with a specific focus on indications and outcomes within the military and young athletic population.

Feasibility and 3D Planning of a Novel Patient-Specific Instrumentation Technique in Medial Opening-Wedge High Tibial Osteotomy

A novel approach for opening-wedge high tibial osteotomy (OWHTO) with patient-specific instrumentation (PSI) was evaluated for its safety, feasibility, and accuracy. Next, the mechanical medial proximal tibial angle (mMPTA) was assessed as a potential planning angle by investigating the relation with the mechanical femorotibial angle (mFTA). Ten OWHTO cases were 3D planned using the mMPTA and operated with a customized 3D-printed wedge and cast which resembled the intended osteotomy opening. Patients were closely monitored for intraoperative and postoperative complications up to 1 year after surgery. Radiological assessment was conducted on full leg standing radiographs and supine lower limb computed tomography-scans preoperatively and 3 months after surgery. No intraoperative complications or logistical issues during PSI processing were observed. Absolute accuracy outcomes showed a correction error of 1.3° ± 1.1 mMPTA and 0.9° ± 0.6 mFTA with all osteotomies falling in (-2°; + 2°) mFTA around the target. The mMPTA and mFTA were found to have a strong correlation in both 3D (r = 0.842, p = 0.002) and 2D (r = 0.766, p = 0.01) imaging for effective correction. The study confirmed the development of a safe and feasible PSI technique in OWHTO with excellent accuracy outcomes. The strong correlation between the mMPTA and mFTA indicated that soft tissue changes after OWHTO are of minor significance to the final alignment in ligament-stable patients. Finally, the mMPTA was found to be a reliable planning angle in 3D software for obtaining the intended lower limb realignment and its use can therefore be recommended in modern OWHTO planning.

Radiological assessment of lower limb alignment

The full-length standing radiograph in an anteroposterior projection is the primary tool for defining and measuring limb alignment with definition of the physiological axes and mechanical and anatomic angles of the lower limb.

We define the deformities of the lower limb and the importance of correct surgical planning and execution.

For patients with torsional malalignment of the lower limb, computerized tomography scan evaluation is the gold standard for preoperative assessment.

Cite this article: EFORT Open Rev 2021;6:487-494. DOI: 10.1302/2058-5241.6.210015

Assessing Radiographic Knee Osteoarthritis: An Online Training Tutorial for the Kellgren-Lawrence Grading Scale

INTRODUCTION

Knee osteoarthritis (OA) is a degenerative form of arthritis commonly diagnosed in older adults. It presents clinically with patient complaints of pain and impaired function, which are thought to result from cartilage degeneration and other skeletal changes. These changes can by examined radiographically and quantified using the semiquantitative grading scale known as the Kellgren-Lawrence (KL) scale. Currently, no standard training exists for KL grading, which may explain the unsatisfactory reliability of this tool in OA research. Therefore, the objective of this project was to develop a training tutorial for KL grading of knee OA to educate assessors on possible areas of inconsistency in grading.

METHODS

The tutorial was developed in an e-learning authoring tool, Articulate Presenter. The content focuses on the poor reliability of KL grading, normal anatomy of a knee radiograph, and multiple examples of bony changes within the knee and their relation to different grades of the KL scale. The tutorial was presented to a group of health sciences graduate students at the University of Colorado Denver.

RESULTS

Students were able to complete the training and an associated assessment in under an hour and reported improved confidence with assessing radiographic knee OA. Furthermore, they demonstrated favorable inter- and intrarater reliability scores in applying KL grading.

DISCUSSION

To our knowledge, this is the first attempt to standardize training in KL grading for knee OA and to examine the effects of this training on reliability.