Influence of gravitoinertial force level on the subjective vertical during recumbent yaw axis body tilt.

We tilted recumbent subjects at various angles about their yaw (foot to head) axis and had them indicate the direction of their subjective vertical and apparent head midline about the same axis. One set of tests was conducted during parabolic flight maneuvers where the background gravitoinertial acceleration varied from 0 to 1.8g. The blindfolded subjects (n = 6) were tested supine and at tilts of 60 degrees and 30 degrees left and right about their horizontal long body axis. They used a gravity neutral joystick to indicate their subjective vertical or their head midline continuously from the high force through the 0g portions of parabolas. In 0g, all subjects felt supine and oriented the joystick perpendicular to their body when indicating the subjective vertical. This points to strong influences of the symmetric somatic touch and pressure cues from the apparatus on orientation when the otolith organs are unloaded. In contrast to the settings in 0g, settings of the subjective vertical in 1g and 1.8g varied as a function of body orientation. However, the settings did not differ between 1g and 1.8g test conditions. Subjective vertical judgments were also made by subjects (n = 11) in the Brandeis slow rotation room, with the room stationary and rotating at a speed that produced a 2g resultant of gravitational and centrifugal acceleration. There were no differences between settings of the subjective vertical made in 1g and 2g. The similarity of 1g and hyper-g settings during recumbent yaw tilts, both in parabolic flight and in the rotating room, contrasts with the previously observed, strong influence which force levels above 1g have on settings of the subjective vertical during tilt of the body in pitch or roll. The findings for all three axes are consistent with a recently developed model of static spatial orientation.

Combined nuclear and digital subtraction contrast arthrography in painful knee prosthesis.

The evaluation of a painful knee prosthesis remains a difficult problem for both orthopaedic surgeons and radiologists. We have compared digital subtraction arthrography with nuclear arthrography in 7 patients with a painful knee prosthesis. Three patients showed a loose tibial component, demonstrated by both digital subtraction and nuclear arthrography. All 3 underwent revision of their prosthesis. One patient had an equivocal digital subtraction arthrogram and negative nuclear arthrogram, while both studies were negative in the 3 remaining patients. Nuclear arthrography is a simple procedure and can provide useful additional information when combined with digital subtraction arthrography.

The diagnosis of reflex sympathetic dystrophy using an algometer.

Thirty-three patients with reflex sympathetic dystrophy were studied prospectively to ascertain the pressure-pain threshold of affected and unaffected limbs. The affected side had a lower threshold which was found to be statistically significant. In all 18 patients with upper limb involvement, the pain threshold was reduced on the affected side, but this applied to only 11 of the 15 with leg involvement. This difference may be because patients with lower limb symptoms had been referred later in the course of the syndrome. We showed by repeated tests that after an average of 49 days there was a slow return to normality. The estimation of pressure-pain thresholds may help in the earlier diagnosis of reflex sympathetic dystrophy.

Pugh nail system as a form of treatment for fractures of the proximal femur.

A retrospective study of the results of treatment of 177 patients who had sustained a fracture of the proximal femur was undertaken. The social background, type of injury, operation performed, duration of stay after operation, mortality and morbidity were recorded and compared with the results published by other workers. It is concluded that the Pugh sliding nail system adequately fixes most fractures of the proximal femur. It allows early postoperative mobilization and discharge to the home environment for most patients. The overall mortality and morbidity compares favourably with results published for the dynamic compression screw. Treatment of the elderly patient with a displaced subcapital fracture of the femoral neck remains a problem, due to the high incidence of failure of fixation. It may be that for this group of patients a primary hemiarthroplasty is the treatment of choice. A prospective study to resolve this issue is required. The cost of a Pugh nail is considerably less than that of a dynamic compression screw.

The long-term results of closed palmar fasciotomy in the management of Dupuytren's contracture.

Twenty-three patients were reviewed an average of 5.3 years after a closed palmar fasciotomy for the correction of Dupuytren's contracture. Results suggest that this procedure is best suited to those whose contracture is mainly at the MP joint and that approximately 55% of such patients can expect the correction to be maintained for at least five years. In those patients with severe deformity affecting the PIP joint in addition to the MP joint, this may be a useful preliminary procedure, but is unlikely to be of any long term benefit.