Biomechanical Study On The Ulnar Ligaments Injuris Of The Wrist

Injury of ligaments in the ulnar wrist is a major cause of ulnar-sided wrist pain, which clinical diagnosis is based on the wrist arthroscopy. But whether the restoration is necessary, it is a controversial issue. This experimentation used the normal wrist specimen, cut off ulnar-sided ligaments according to a certain order, then the prescale film was inserted into the radiocarpal joint. The contact stress was measured. Compared with these stress, it can make a definite conclusion wherther the restoration is necessary.MethodsFive wrists were loaded through the tendons of the flexor carpi radialis, flexor carpi ulnaris, extensor carpi radialis longus, extensor carpi radialis brevis, and extensor carpi ulnaris. The load was 12 kg dead weight for 5 minutes. Before loading, the prescale film was inserted into the radiocarpal joint. The contact stress was measured, when the wrist was in respective position of palmer flexion 30°, dorsal flexion 30°, ulnar deviation 30°, radial deviation 10°, and neutral position. The mean stress of the region on the prescale film was measured using FPD-305E and 306E. To cut off the ulnar-lunate ligament, the ulnar-triquetra ligament and the lunotriquetra ligament respectively, and then repated the above steps.Results Sectioning of the ulnar-lunate ligament and the ulnar-triquetra ligament had little effect on carpal kinetics, The scaphoid fossa stress and lunate fossa stress were changed a little. But sectioning of the lunotriquetra ligament producing a considerable change of the scaphoid fossa stress and lunate fossa stress.ConclusionIt is not necessary for reparing when the ulnar-lunate ligament and the ulnar-triquetra ligament were destructed, If the injury is in combination with the lunotriquetra ligament, the restoration is necessary.