The first metatarsal bicorrectional head osteotomy (distal "L"/Reverdin-Laird procedure) for correction of hallux abducto valgus: a retrospective study

A retrospective analysis of the distal "L" osteotomy with bunionectomy (Reverdin-Laird procedure) for correction of hallux abducto valgus was performed. Sixty-nine cases meeting strict eligibility and exclusion criteria underwent evaluation an average of 33.51 months after the procedure. The evaluation included radiographs, physical examination, patient survey, and medical record review. The average decreases in radiographic angles were as follows: Hallux abductus: 19.97 degrees, relative intermetatarsal angle: 7.49 degrees, proximal articular set angle: 13.9 degrees. Twenty-seven cases demonstrated a negative proximal articular set angle. Only five of these cases resulted in clinical hallux varus. There was an average of 4.23 mm. of first metatarsal shortening with this procedure. Average postoperative range of motion of the first metatarsophalangeal joint was 72.05 degrees. The appearance of the forefoot was judged good or excellent in 91.3% of the surgeries. Hallux position was in rectus or mild abductus in 86.9% of cases. Complication rates included hallux varus, metatarsalgia, lesion subsecond metatarsophalangeal joint, pain at the surgical site, long-term stiffness, pin tract infection, and numbness. There were no cases of osteomyelitis or avascular necrosis. Survey results revealed a high level of patient satisfaction with this procedure (94.2%). Patient satisfaction was dependent on elimination of pain and ability to wear the desired shoe gear comfortably, not on hallux position.

Blood flow changes in gingival tissues due to the displacement of teeth

Changes in human gingival blood flow were measured using a Laser doppler flowmeter. The change of blood flow was correlated to the degree of force applied and there were variations in measurement of decreased blood flow among the subjects. The variation was attributed to the degree of tooth displacement and the size of the interdental space. This study examined the effect of tooth displacement on the gingival blood flow, as well as age and sex differences. Blood flow in gingival tissue was measured using a laser doppler flowmeter, and displacement of the maxillary incisors was measured using an eddy current sensor. The correlation coefficient of the decreased blood flow to the tooth displacement was 0.809, and it was higher than that to the degree of applied force (r = -0.625). The regression coefficient of decreased blood flow to the displacement of teeth was significantly correlated to the interdental space. The regression coefficient of decreased blood flow to the percentage of tooth displacement was independent of the interdental space. However, the regression coefficient of decreased blood flow to the percentage of tooth displacement was significantly higher in young subjects than in adults.

Effect of orthodontic forces on blood flow in human gingiva

The relationship of gingival blood flow to the magnitude and duration of applied force was studied in humans using Laser Doppler flowmetry. The sample consisted of five adult volunteers with interdental space between their maxillary central incisors. The labial surface of each central incisor was bonded with a buccal tube and a spring force was applied to close the space. The forces applied were 50 g, 80 g, 120 g, and 250 g. Each force was applied for 30 seconds, 60 seconds, 90 seconds, 5 minutes, and 10 minutes. The blood flow signals were recorded continuously using a pen recorder. Measurements indicated that blood flow was negatively correlated to the amount of force applied. The duration of reactive hyperemia was positively correlated to the duration of force. Laser Doppler flowmetry measures blood flow in superficial periodontal tissues. Yet, the relationship of blood flow changes to the magnitude and duration of orthodontic force suggests that measurements of gingival blood flow may provide a means of estimating physiologic orthodontic forces.