Lunatomalacia associated with congenital shortening of the ulna in Langer-Giedion syndrome: a case report.

A 22-year-old patient with type I trichorinophalangeal Langer-Giedion syndrome presented a stage 2 osteonecrosis of the lunate associated with congenital shortening of the ulna and carpal tunnel syndrome. The patient was treated by shortening osteotomy of the radius and median nerve neurolysis, with an excellent result. This case provides an additional piece of evidence associating ulnar-minus variance with lunatomalacia, and another argument in favor of the theory that Kienböck's disease results from microfractures sustained by the lunate under an abnormal stress distribution situation.

Radiocarpal articular pressures during the reduction of distal radius fractures.

OBJECTIVES: To measure in vivo radiocarpal articular pressures during closed reduction and external fixation of distal radius fractures. DESIGN: Intraoperative measurements using a sterile pressure sensitive sensor specially constructed for this application. SETTING AND PATIENTS: Ten patients with a closed distal radius fracture stabilized by radiometacarpal external fixation. Radiocarpal pressures measured during transarticular distraction, wrist palmar flexion, wrist ulnar inclination, and fracture reduction. MAIN OUTCOME MEASUREMENTS AND RESULTS: Transarticular distraction resulted in a substantial decrease of the articular pressure, averaging -158.1 mmHg. Palmar flexion resulted in a mean pressure increase of 91.8 mmHg. The reduction of the fracture using a combination of distraction, palmar flexion and ulnar deviation resulted in either an increase or decrease of articular pressure, but always with a tendency toward progressive normalization of the pressure, with a mean slope of 3.2 mmHg/min. CONCLUSIONS AND CLINICAL RELEVANCE: The phenomena leading to the reduction of distal radius fractures could be related in part to a decrease of the intraarticular pressure, which may be responsible for a suction effect on the intraarticular bone fragments.

A biomechanical study of the ulnar nerve at the elbow.

The relative elongation with elbow flexion of the ulnar nerve, proximal and distal to the cubital tunnel, and of the cubital tunnel retinaculum, was measured in cadaver specimens by stereophotogrammetry. The proximal part of the ulnar nerve elongated significantly with full elbow flexion. No significant change of length was measured in the distal part of the nerve. The length of the cubital tunnel retinaculum increased by an average of 45% from full elbow extension to full flexion.

Is early bone scintigraphy a reliable method to assess the viability of vascularized bone transplants?

This clinical study reveals radiomarker uptake in corticocancellous non-vascularized bone grafts as early as 3 days postoperatively. It therefore calls into question whether seventh-postoperative-day bone scintigraphy is a reliable method for determining the viability of vascularized bone grafts.

Biomechanical properties and design considerations in upper extremity external fixation.

External fixation is an excellent technique for the osteosynthesis of fractures affecting the upper extremity. The rational use of the technique is based on sound principles of biology and biomechanics. Good pin design and application techniques are among the important factors for successful outcome. These factors are discussed in this article along with the advantages of external fixation.

A normal data base of posteroanterior roentgenographic measurements of the wrist.

In 120 adults, we measured the dominant wrist on posteroanterior roentgenograms in order to determine the normal dimensions and variations according to age and sex. Men and women were equally represented as were two age-groups (twenty-five to forty years and forty-one to sixty years). The roentgenograms were made, with standard exposure and development techniques, with the wrist and forearm in a neutral position and the x-ray tube aligned vertical to the radial styloid. The roentgenogram that was made with the wrist in the mid-coronal plane was digitized and was used to measure distances between specified landmarks. The mean ulnar variance was -0.9 millimeter (normal range, -4.2 to 2.3 millimeters). The average carpal height ratio was 53 per cent (normal range, 46 to 61 per cent). The mean radial inclination was 24 degrees (range, 19 to 29 degrees). The carpal-radial and carpal-ulnar ratios were smaller in women. The width of the distal radio-ulnar joint was reduced in the older subjects. There was a significant positive relationship (p < 0.0001) between the maximum force reached and the length of the third metacarpal. We believe that information concerning the normal roentgenographic measurements and relationship between the bones of the wrist can be used (1) to follow the progression of carpal instabilities, osteonecrosis, osteoarthrosis, or rheumatoid arthritis; (2) in clinical research; and (3) in the design of wrist implants.

Changes in wrist and forearm configuration with grasp and isometric contraction of elbow flexors.

The purpose of this study was to determine the changes in wrist and forearm configuration with grasp and elbow flexor contraction by analysis of resting and grasping x-ray films of 15 normal adults and forearm scanograms of 10 other normal subjects. With grasp, a significant proximal migration of the radius (averaging 0.9 mm), a decrease in the carpal height ratio, and an increase in the lunate uncovering index were observed. With flexor contraction, there was a significant decrease in the forearm interosseous space.