Alterations in stress distribution patterns through the forearm joint surface of the elbow in baseball players assessed using computed tomography osteoabsorptiometry

Computed tomography Osteoabsorptiometry: Review of bone density, mechanical strength of material and clinical application

Computed Tomography (CT) imaging is an effective non-invasive examination. It is widely used in the diagnosis of fractures, arthritis, tumor, and some anatomical characteristics of patients. The density value (Hounsfield unit, HU) of a material in computed tomography can be the same for materials with varying elemental compositions. This value depends on the mass density of the material and the degree of X-ray attenuation. Computed Tomography Osteoabsorptiometry (CTOAM) imaging technology is developed on the basis of CT imaging technology. By applying pseudo-color image processing to the articular surface, it is used to analyze the distribution of bone mineralization under the articular cartilage, evaluate the position of prosthesis implantation, track the progression of osteoarthritis, and determine the joint injury prognosis. Furthermore, this technique was combined with indentation testing to discuss the relationship between the high bone density area of the articular surface, the mechanical strength of the bone, and the anchorage stability of the implant, in addition to the study of the relationship between mechanical strength and bone density. This narrative study discusses the pre- and postoperative evaluation of medical device implantation position, orthopedic surgery, and the clinical treatment of bone injury and degeneration. It also discusses the research status of CTOAM technology in image post-processing engineering and the relationship between bone material and mechanical strength.

Effect of High Tibial Osteotomy on the Distribution of Subchondral Bone Density Across the Proximal Tibial Articular Surface of the Knee With Medial Compartment Osteoarthritis

BACKGROUND

The effect of high tibial osteotomy (HTO) on the stress distribution across the knee joint is not completely understood. Subchondral bone density is considered to reflect the pattern of stress distribution across a joint surface.

PURPOSE

To assess the distribution of subchondral bone density across the proximal tibia in nonarthritic knees and in the knees of patients with osteoarthritis (OA) before and after HTO.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

We retrospectively collected radiological and computed tomography data from 16 patients without OA (control group) and 17 patients with OA. Data from the OA group were collected before and 1.5 years after HTO. Subchondral bone density of the proximal tibia was assessed with computed tomography-osteoabsorptiometry. The locations and percentages represented by high-density areas (HDAs) on the articular surface were quantitatively analyzed.

RESULTS

The ratio of the HDA of the medial compartment to the total HDA (medial ratio) was significantly higher in the preoperative OA group (mean, 80.1%) than in the control group (61.3%) (P < .001). After HTO, the medial ratio decreased significantly to 75.1% (P = .035 in comparison with preoperative values) and was significantly correlated with the hip-knee-ankle angle in both groups: control (r = -0.551; P = .033) and OA (r = -0.528; P = .043). The change in medial ratio after HTO was significantly correlated with the change in hip-knee-ankle angle (r = 0.587; P = .035). In the medial compartment, the HDA in the most lateral region of 4 subregions increased after HTO, but that in 3 medial subregions decreased.

CONCLUSION

In this exploratory study, HTO shifted the HDA of the medial compartment of the proximal tibial articular surface toward the lateral compartment. In contrast, the HDA of the most lateral region of the medial compartment increased after HTO. This change in subchondral bone density may result from the change in stress distribution.

Alteration in stress distribution patterns through the elbow joint in professional and college baseball pitchers: Using computed tomography osteoabsorptiometry

BACKGROUND

Long-term pitching activities change the stress distribution across the elbow joint surface in living subjects, however the influence of the different strength of stress on the stress distribution patterns remain unclear. The aims of this study were to evaluate the distribution of subchondral bone density across the elbow joint in different levels of pitchers, and to reveal the influence of the strength of stress on the elbow joint surface under long-term loading conditions of baseball pitching.

METHODS

The current analysis was performed using computed tomography (CT) image data obtained from the throwing side elbow of 12 nonthrowing athletes (controls), 15 college baseball pitchers (college group) and 13 professional baseball pitchers (professional group). The distribution patterns of subchondral bone density through the articular surface of the elbow joints were assessed using a CT osteoabsorptiometry method. The quantitative analysis was based on location and percentages of high-density area on the articular surface.

RESULTS

High-density area in the college and professional groups were found in the anterior part of the captellum, posterior part of the trochlea and radial head. In the professional group, the percentages of high-density area in the anterior part of the capitellum, posterior part of the trochlea, radial head and olecranon were significantly greater than in the college group.

CONCLUSIONS

Stress distribution on the articular surface of the elbow joint was affected by pitching abilities or competitive levels. Our analysis indicates that high strength of stress in professional baseball players produce potential risk of elbow injuries.

Alteration of Stress Distribution Patterns in Symptomatic Valgus Instability of the Elbow in Baseball Players: A Computed Tomography Osteoabsorptiometry Study

BACKGROUND

Repetitive valgus stress applied during a throwing motion can lead to various elbow disturbances, including ulnar collateral ligament (UCL) injury. Subchondral bone density reportedly reflects the cumulative force on a joint surface under actual loading conditions.

PURPOSE

(1) To evaluate the distribution of subchondral bone density across the elbow joint in asymptomatic baseball pitchers and symptomatic valgus instability pitchers and (2) to clarify the alterations in stress distribution pattern associated with symptomatic UCL insufficiency pitching activities.

STUDY DESIGN

Controlled laboratory study.

METHODS

Computed tomography (CT) imaging data were collected from the dominant-side elbow of 7 nonathletic volunteers (controls), 12 asymptomatic pitchers (asymptomatic group), and 12 symptomatic valgus instability pitchers with UCL insufficiency (symptomatic group). Bone mineral density across the elbow joint was measured with CT osteoabsorptiometry. A 2-dimensional mapping model was divided into 4 areas of the distal end of the humerus and 5 areas of the ulna with the radial head. The locations and percentages of high-density areas on the articular surface were quantitatively analyzed.

RESULTS

High-density areas in the asymptomatic and symptomatic groups were found in the anterolateral and posteromedial parts of the humerus and in the radial head, posteromedial to the ulna. The high-density areas in the anterior and posteromedial of the humerus, the radial head, and the posteromedial part of the ulna in the controls were smaller than those in the baseball group. In the symptomatic group, the percentages of high-density areas in the anterolateral part of the humerus (mean, 36.3%; 95% CI, 31.9%-40.7%) and the anterolateral part of the ulna (mean, 31.7%; 95% CI, 24.3%-39.1) were significantly greater than those in the asymptomatic group (P = .047 and P < .0001, respectively).

CONCLUSION

Symptomatic UCL insufficiency was associated with characteristic high-stress distribution patterns on the anterolateral part of the capitellum and the anterolateral part of the ulna. The current results indicate that symptomatic UCL insufficiency produces excessive and cumulative stress in the elbow joint.

CLINICAL RELEVANCE

The information obtained from the CT images can useful for early detection of overstress conditions of the elbow joint.

A systematic, multimodality approach to emergency elbow imaging

The elbow is a complex synovial hinge joint that is frequently involved in both athletic and nonathletic injuries. A thorough understanding of the normal anatomy and various injury patterns is essential when utilizing diagnostic imaging to identify damaged structures and to assist in surgical planning. In this review, the elbow anatomy will be scrutinized in a systematic approach. This will be followed by a comprehensive presentation of elbow injuries that are commonly seen in the emergency department accompanied by multimodality imaging findings. A short discussion regarding pitfalls in elbow imaging is also included.