Purpose of the study: Spastic hypertony of the upper limb produces pronation of the forearm with flexion of the wrist and fingers. Treatment is generally based on injections of botulinum toxin and sometimes on selective neurotomy.

Material and methods: In order to achieve better selection of the motor branches innervating the muscles requires a precise knowledge of the extramuscular innervation. Similarly, for botulinum toxin, injections must be made as close as possible to zones with the greatest density of intramuscular nerve endings, considered as the zones having the greatest number of neuromuscular junctions. Knowledge of these zones is currently insufficient. We therefore conducted a macroscopic then microscopic dissection of the muscles of the ventral forearm in 30 specimens to study extra- and intra-muscular innervations and the distributions of the nerve endings.

Results: Surface maps were drawn to describe the precise localization of the motor branches for each muscle. These maps were designed as guides for surgical approaches for selective neurotomy. Then for each muscle, the zones with the greatest density of nerve endings were delimited in segments which could be used to define optimal zones of injection of botulinum toxin.

Purpose of the study: Occult fractures of the carpal bone are underestimated. An undetected fracture of the scaphoid will not be immobilized and will lead to nonunion and osteoarthritic degradation. In order to avoid late diagnosis and functional loss, in addition to lost chances and legal suites, we validated a quantitative radioscin-tigraphic (QRS) tool in a randomized prospective trial conducted from 1997 to 2003 in a routine practice setting. The series included 667 patients with wrist trauma presenting a normal plain x-ray one day 0. After day 8 these patients underwent QRS.

Material and methods: The principle of the technique consists in a classical technetium scintigraphy with two technical improvements:

quantification of uptake: uptake two-fold greater on the injured side is a sign of «certain» fracture;

Results: Forty percent of the wrist trauma patients (260/667) with a normal plain x-ray presented an occult fracture (uptake > 2 on QRS). QRS was performed on day 17.7 on average. Fractures of the scaphoid were the most frequent (42%). The uptake ratio was higher if the QRS was performed from day 11 to day 20. Statistical analysis showed that uptake ratio > 2 was independent of age, gender, bone volume, and time to QRS.

Discussion: As demonstrated by Dikson, Dias, Thomp-son and Kuckla, repeated x-ray images do not increase the rate of diagnosis of carpal bone fractures. Spitz demonstrated that scintigraphic uptake on the trauma side more than twice that on the healthy side is a sign of fracture. Garbuio, NOvert and Lepage validated QRS as a sensitive and specific diagnostic tool for occult fractures. They demonstrated that QRS is less costly, more reliable than MRI and that there are no false positives.

Conclusion: Exploration of a «bone problem» in a patient with wrist trauma must not ignore sensitive and specific tests. Ultrasonography is operator-dependent and requires validation. We thought that QRS would not resist the development of routine MRI, but observed the contrary. QRS remains the gold standard diagnostic tool for ruling out a fracture of the carpal bones.