The majority of twist drills used in orthopaedics are very similar to chisel pointed metal drilling bits. Modifications usually observed are reduction of the point angle to 90 deg and sometimes grinding of the entire cutting lip at 0 deg rake angle, which appeared to have been made arbitrarily without any advantage. We have attempted to design a surgical drill bit with the objective of minimization of the drilling thrust and temperature and effective removal of bone chips. Our results showed that the presence of the chisel edge was mainly responsible for increasing the thrust force and the temperature developed. The effects of a constant feed rate and thrust on the peak temperature were also examined. The combined effect of the helix and the point angles on the rake angle which in turn determines the cutting efficiency was analyzed for various types of surgical bits. Based on our results and previously published data from the literature an optimized drill bit was designed with a split point, a point angle of 118 deg, a parabolic flute, and a helix angle of 36 deg and its performance was compared with other existing surgical drill bits. For drilling in compact bone, the new design decreased the thrust load by 45 percent an the peak temperature rise by 41 percent. Similar improvements were also recorded for drilling bone cement. The time of drilling a bone cortex was also significantly reduced and "walking" on the curved bone surface was eliminated and dimensional tolerance on hole sizes was improved. The new design is likely to reduce the time of surgery and also minimize the tissue damage.

The onset and progression of numerous protein misfolding diseases are associated with the presence of oligomers formed during the aberrant aggregation of several different proteins, including amyloid-β (Aβ) in Alzheimer's disease and α-synuclein (αS) in Parkinson's disease. These small, soluble aggregates are currently major targets for drug discovery. In this study, we show that trodusquemine, a naturally-occurring aminosterol, markedly reduces the cytotoxicity of αS, Aβ and HypF-N oligomers to human neuroblastoma cells by displacing the oligomers from cell membranes in the absence of any substantial morphological and structural changes to the oligomers. These results indicate that the reduced toxicity results from a mechanism that is common to oligomers from different proteins, shed light on the origin of the toxicity of the most deleterious species associated with protein aggregation and suggest that aminosterols have the therapeutically-relevant potential to protect cells from the oligomer-induced cytotoxicity associated with numerous protein misfolding diseases.

We reviewed 19 children who had undergone a new modification of the L'Episcopo procedure for obstetric brachial plexus palsy. Through an axillary approach the latissimus dorsi tendon was rerouted anteriorly to the humerus and then anastomosed to the teres major tendon routed posteriorly. At an average follow-up of four years two months, the mean increase in shoulder abduction was 26 and the mean increase in external rotation was 29#{176}. No neurovascular injury or postoperative infection occurred. Two patients had complications, and five did not gain from the procedure.

Injuries to the shoulder and elbow are common in baseball pitchers,' with the incidence of disability directly related to the duration of exposure and to the intensity of participation. Adams,2 in a study of 80 Little League and Pony League pitchers, 9 to 14 years of age, reported significant problems in 95%, the most common being accelerated growth and separation of the medial epicondylar epiphysis. Torg et al.,' in a study of 49 pitchers 9 to 18 years of age, found that 70% had soreness when pitching, but there were fewer severe problems than in Adams' study. He felt the difference was due to a better attitude since, presumably, his pitchers were less competitive. Only studies performed or sponsored by the Little League have concluded that the incidence of injury is insignificant in pitchers. 1, 4 Professional pitchers uniformly show hypertrophy of the flexor forearm muscles, over 50% have a flexion contracture and 30% have an increased valgus angle compared with the opposite extremity.~ The elbow problems that occur appear to be related to valgus stress as the shoulder internally rotates from a position of maximum external rotation.~ The medial joint structures are subjected to traction, while compression occurs at the radial humeral joint. Separation or fragmentation of the medial humeral epicondyle may develop, with traumatic arthritis or osteochondritis dissecans laterally. In older pitchers osteochondritis of the olecranon (possibly a later manifestation of the same forces) may be due to bony hypertrophy, medial stress, and cubitus valgus. The incidence of shoulder disability appears to increase with age and proficiency. Osteochondritis of the proximal humeral epiphysis has been reported in children, while in older pitchers, tendonitis and muscle strain are more common The exact muscle group involved can often be correlated with the phase of the pitch.8,9 9 At the end of wind-up when the shoulder is extended, abducted, and externally rotated and the body is beginning its forward motion, symptoms may occur at the pectoralis major insertion, the origin of the anterior deltoid, or over the long head of the biceps, which tends to subluxate out of the bicipital groove in this position. During followthrough, the posterior deltoid may be stretched near its origin from the spine of the scapula, and (especially with a curve ball) tendonitis may develop in the long head of the triceps at its origin from the inferior border of the glenoid. In addition, tendonitis of the rotator cuff is increas-