Noboru Ikeda

Osteochondral Grafting and Arthroplasty for End-Stage Osteochondritis Dissecans of the Capitellum A Case Report and Review of the Literature

The prevalence of osteochondritis dissecans of the capitellum is high among people who have played baseball actively since childhood, and repetitive throwing is considered to be one of the main etiologic factors of this disease. 3, 16, 27 During the acceleration phase of throwing, the elbow joint can be stressed into a valgus position, 32 and the capitellum of the humerus is then subjected to compression and shear forces. 13, 22 Osteochondritis dissecans of the elbow remains one of the leading causes of permanent elbow disability in adolescents and young adults engaged in throwing sports or gymnastics. Severe osteoarthritic changes can develop in the elbow in the end-stages of the disease. Research efforts are currently focused on treatment of established articular surface defects. Newer procedures, such as the transplantation of osteochondral, perichondral, and periosteal tissues; chondrocyte transplantation; and the biochemical manipulation of the chondrocyte environment, may provide us with exciting new approaches to this old problem. In this study, we report a new treatment for end-stage osteochondritis dissecans lesions of the humeral capitellum. The first procedure was a vertical-wedge osteotomy of the lateral humeral epicondyle with osteochondral grafting to achieve a near-normal articular surface. The second procedure was arthroplasty of the elbow joint for osteophyte resection to increase the range of motion. At follow-up 35 months after the first procedure the result was good. CASE REPORT

Quantitative comparison of osteoconduction of porous, dense A-W glass-ceramic and hydroxyapatite granules (effects of granule and pore sizes).

The osteoconductive potentials of dense, small porous and large porous apatite- and wollastonite-containing glass-ceramic (A-W GC) granules of various sizes implanted in rat tibiae were evaluated quantitatively, by determining their affinity indices. The average affinity indices of all types of A-W GC were high. The dense A-W GC granules had the highest values (97.0+/-5.5%), followed by the large porous (87.1+/-8.4%) and then the small porous granules (79.0+/-8.4%). There were no significant differences among the osteoconductive potentials of the different sizes of each form of A-W GC granule. The osteoconductive potentials of four types of commercially available porous hydroxyapatite (HA) granules were compared with those of the small porous A-W GC granules, using the affinity index and the proportion of newly formed bone relative to that of the granules in the bone defect. The values of the former parameter for three types of HA and those of the latter for four were significantly inferior to those of A-W GC. The difference between the osteoconductive potentials of A-W GC and HA was considered to be related to the rate of surface apatite layer formation.

Deep Flexion-Oriented Bisurface-Type Knee Joint and Its Tibial Rotation That Attributes Its High Performance of Flexion

In 1989, we developed an artificial knee prosthesis that could accommodate the oriental lifestyle where people would sit more often on the floor than on a chair. The knee had a bisurface feature with an auxiliary joint of a ball and socket at the center of the posterior part aiming at an improved flexional function. The auxiliary joint functions not only to facilitate a rollback movement but also to add a rotational movement. It was investigated whether this knee prosthesis could show an internal rotation of the tibia during flexion such as the physiologic movement of the knee. The internal rotation of the tibia was evaluated for the patients who could sit on legs in the oriental style after total knee arthroplasty. The average flexion angle of patients who achieved this style of sitting was 144.1°, and the average internal rotation was estimated as 14.3° by a pattern matching method using a computer-assisted design system.

A modification of the retrograde medullary screw for the treatment of bilateral pubic ramus nonunions: a case report.

We describe a patient with bilateral pubic ramus nonunions who was treated successfully with a modification of the retrograde medullary screw technique, in which the screw orientation was altered so that it engaged the cancellous bone in the inferior part of the anterior column and the anterior-inferior cortex of the fossa acetabuli. The modification should be one option when the original technique is judged to be difficult to perform.

Can Post-Cam Function Be Replaced by Addition of a Third Condyle in PS TKA?

The purpose of the study was to analyze the effectiveness of an additional ball and socket articulation in implanted knees and whether it can replicate post-cam function. Fifteen knees implanted with a cruciate substituting (CS) polyethylene without a post and ten knees implanted with a posterior stabilized (PS) polyethylene with a post were analyzed using 3D model fitting approach. Two types of designs showed similar posterior translation and similar axial rotation. Most of the contact points at the ball and socket joint stayed within the socket height for the PS group. This study indicates that the ball and socket joint is able to function as a replacement of the post-cam mechanism, which might serve as a new way to achieve posterior stability.

Total Avulsion Fracture of the Coronoid Tubercle Caused by Baseball Pitching A Case Report

When an object such as a baseball or a javelin is thrown there is a strong valgus stress on the elbow during the acceleration phase of throwing. Chronic pain on the medial aspect of the elbow is a common complaint in athletes involved in these sports. The pain is attributed to many causes: repetitive injuries of the ulnar collateral ligament, microtear or fibrosis of the common flexor-pronator muscles, loose bodies, and osteoarthritic change of the medial humeroulnar joint. Complete tear of the ulnar collateral ligament, rupture of the common flexor muscles, and avulsion fracture of the medial epicondyle have been reported as acute or acute-on-chronic clinical manifestations of throwing injuries of the elbow. To our knowledge, acute avulsion fracture of the coronoid tubercle, onto which the anterior bundle of the ulnar collateral ligament inserts, has not been reported before. We describe a case of total avulsion fracture of the coronoid tubercle caused by baseball pitching.

In vivo kinematic effects of ball and socket third condyle as a post-cam mechanism in tri-condylar knee implants

BACKGROUND Tri-condylar implants containing a ball and socket third condyle as a post-cam mechanism were developed to accommodate a lifestyle requiring frequent deep flexion activities. The purpose of the current study was to examine the kinematic effects of the ball and socket third condyle during a deep knee bend activity, and to confirm the contact status of the ball and socket joint. METHODS Seventeen knees implanted with tri-condylar implants were analyzed using a 3D to 2D registration approach. A distance of less than 1mm denoted ball and socket contact. Medial and lateral contact positions and axial rotation were compared before and after contact. Moreover, the contact position at the third condyle and the center of the ball joint were analyzed. RESULTS After the third condyle contact, posterior translation of the medial and lateral contact positions increased considerably. Meanwhile, the angular rotation remained still. The center of the third condyle did not move after contact, and the contact position at the third condyle remained low. CONCLUSIONS The third condyle induced intensive posterior translation of both condyles, and did not prevent axial rotation, which was proved to work properly as a posterior stabilizing post-cam mechanism.