Chong Il Yoo

Chronic radial head dislocation in children, Part 2: results of open treatment and factors affecting final outcome.

Fifteen elbows (3 congenital, 12 traumatic) in 14 children (mean age 9.5 years) with chronic radial head dislocation for at least 3 months (range 3–180 months) underwent radial head-sparing reconstructive surgery and were followed up at an average of 43.5 months postoperatively (range 12–105 months). At follow-up, the patients were evaluated radiographically and clinically using range-of-motion measurements and an elbow performance score based on four parameters (deformity, pain, motion, function). Ten cases had excellent results, two had good results, two had fair results, and one case had poor results. Scores at follow-up were evaluated with seven preoperative factors. Among those, the degree of preoperative carrying angle asymmetry associated with flexion contracture correlated significantly with the elbow scores. The most common complication was loss of pronation. The authors advocate radial head reduction and reconstruction in chronic radial head dislocations in children after obtaining informed consent from patient and parents.

Chronic radial head dislocation in children, part 1 : pathologic changes preventing stable reduction and surgical correction

The pathologic changes in 15 elbows of 14 children (2 bilateral congenital, 12 unilateral posttraumatic, mean age 9.5 years) with radial head dislocation unreduced for at least 3 months (range 3–180 months) and their open treatment were reviewed. Common dysplastic changes observed in both congenital and posttraumatic groups included large deformed radial heads, slender radial necks, and ulnar bowing. Changes were bilateral and symmetrical in the congenital group. In traumatic dislocations, patients with more severe deformities had longer delays from time of injury to time of reduction. Persistent pain, limitation of motion, and deformity were unacceptable symptoms to both patients and their parents, prompting surgical intervention. To produce a smooth rotational arc for the radius and maintain it in stable reduction, restoration of the congruency of the capitello-radioulnar joint and correction of the various dysplastic changes were mandatory during open reduction.

The flavonoid quercetin induces apoptosis and inhibits migration through a MAPK-dependent mechanism in osteoblasts

The present study was undertaken to evaluate effects of quercetin, a major dietary flavonoid occurring in foods of plant origin, on cell viability and migration of osteoblastic cells. Quercetin inhibited cell viability, which was largely attributed to apoptosis, in a dose-and time-dependent manner in osteoblastic cells. Similar cytotoxicity of quercetin was observed in adipose tissue-derived stromal cells. Quercetin exerted a protective effect against H2O2-induced cell death, whereas it increased TNF-α-induced cell death. Western blot analysis showed that quercetin induced activation of ERK and p38, but not JNK. Quercetin-induced cell death was prevented by the ERK inhibitor PD98059, but not by inhibitors of p38 and JNK. Quercetin increased Bax expression and caused depolarization of mitochondrial membrane potential, which were inhibited by PD98059. Quercetin induced caspase-3 activation, and the quercetininduced cell death was prevented by caspase inhibitors. Quercetin inhibited cell migration, and its effect was prevented by inhibitors of ERK and p38. Taken together, these findings suggest that quercetin induces apoptosis through a mitochondria-dependent mechanism involving ERK activation and inhibits migration through activation of ERK and p38 pathways. Quercetin may exert both protective and deleterious effects in bone repair.

Avascular necrosis after fracture-separation of the distal end of the humerus in children.

Fracture-separation of the distal end of the humerus in children has been reported infrequently, and may be misdiagnosed as a fracture of the condyle or a traumatic dislocation of the elbow. We discuss eight cases of a seldom reported complication following fracture-separation of the distal end of the humerus. This complication consists of dissolution of the trochlea within three to six weeks postinjury and a defect of the medial or central part of the condyle that develops later. The fractures were severely displaced fracture-separation of the distal end of the humerus with large medial or lateral metaphyseal fragment, but initially misdiagnosed as a fracture of the medial, lateral condyle or a traumatic dislocation of the elbow in six of eight cases. We performed open reduction in six cases because of initial misdiagnosis or because of difficulty in satisfactory closed reduction. We speculated that this complication is due to avascular necrosis of the distal end of the humerus, and that fracture-separation of the distal end of the humerus is more common than reported.

Catastrophic progression of the disassembly of a modular acetabular component.

Disassembly of a metal-backed modular acetabular component used for total hip arthroplasty is becoming more common. If the acetabular disassembly is detected early, the revision procedures are relatively simple. In the case of long-term sustained disassembly, however, there are more complicated problems, and more difficult revision procedures are needed. We report a case of long-term sustained disassembly of a modular acetabular component in order to alert orthopaedic surgeons of the catastrophic progression to more severe complications, such as the loosening of the metal-acetabular component and severe acetabular osteolysis.

Trochlear deformity occurring after distal humeral fractures: magnetic resonance imaging and its natural progression.

Eighteen children (mean age 50.7 months) with trochlear deformities occurring after and related to distal humeral fractures (12 Salter-Harris type 2, 5 supracondylar, 1 Salter-Harris type 4) were evaluated with serial radiographs. The carrying angle and range of motion were measured throughout the follow-up period (up to 13 years after trauma) after definitive treatment. Bony defects on the medial (17 patients) and central (1 patient) regions of the trochlea were observed at a mean of 3.4 months after the trauma. They also persisted up to 4 to 7 years (latest follow-up in an intermediate follow-up group) and eventually reossified by skeletal maturity (in a long-term follow-up group). Magnetic resonance imaging was performed on eight patients after a mean of 1.9 years from injury. Low signal intensity on T2 indicative of cartilage necrosis and an intact articular surface were found. Cubitus varus deformity, which developed in almost all patients, was observed to be nonprogressive after 3 to 4 years but persisted until maturity. Limitation of motion and late neuropathy were not seen.

Morphological Study of Femoral Head and Acetabulum Using MRI in Legg-Calve-Perthes Disease

Purpose: We used MRI to evaluate the morphological relationship of the femoral head and acetabulum with changes of hip position in LCP disease. Materials and Methods: The MRIs of 35 patients (17 pillar B, 18 pillar C; mean age: 7.8 years old) were reviewed in neutral, abduction, abduction-internal rotation, abduction-internal rotation-flexion, and adduction positions. The measurements included epiphyseal extrusion index (EEI), head coverage (HC), and medial gap ratio (MGR). The congruence of the hip joint and adjacent soft tissue changes were also studied. Results: Decreased EEI and increased HC in both pillar B and C from neutral to the abduction and abduction-internal rotation positions were statistically significant (p