Frequency and characteristics of the scaphoid cortical ring sign.

The scaphoid cortical ring sign (CRS) has been identified as a radiological indicator of ligamentous injury of the wrist. It has been associated with some pathokinematic states. There exists a range of wrist positions where the CRS may be normally present. The purpose of this study was to define the range of motion when the CRS can normally be observed on a standard posteroanterior radiograph and, in turn, to define the range where the CRS is not expected to be present. One hundred and nine posteroanterior radiographs of normal wrists were evaluated for the presence, partial presence and absence of the scaphoid CRS. The results were correlated with the radio-metacarpal (RM) angle in neutral palmar-dorsiflexion of the wrist. The range of wrist deviation for the wrists studied was -10.0 degrees (radial deviation) to 23.0 degrees (ulnar deviation). We defined the normal (and abnormal) range as being two standard deviations from the mean. The CRS was present in 25% of the radiographs evaluated. Moreover, the CRS was found to be present at 2.7 degrees (+/-7.7 degrees ) of radial deviation with a calculated range of -18.1 degrees to 12.7 degrees. The CRS was absent at 12.4 degrees (+/-11.7 degrees ) of ulnar deviation. It is concluded that the CRS observed at values less than 13 degrees of ulnar deviation may or may not be abnormal. If the CRS is observed at a RM angle of 13 degrees of ulnar deviation or greater, it should be considered pathological. The CRS, however, should be used in conjunction with other clinical findings of carpal instability.

Extended hindfoot fusions and pantalar fusions. History, biomechanics, and clinical results.

Contemporary techniques of hindfoot and ankle arthrodesis can result in a high rate of osseous union, pain relief, and patient satisfaction. Methods range from open approaches to fully arthroscopic surgical techniques. Arthrodesis should be limited to the joints involved with the arthritic, deforming, or neuromuscular process because the rate and severity of progressive adjacent joint degeneration appear related to the number of joints fused initially. Appropriate joint position, maintained with stable internal fixation applied in compression and augmented with bone-graft material when necessary, should be considered the gold standard for most hindfoot and ankle arthrodeses. External fixation may be used in the revision or salvage setting if needed or when soft tissues or bone stock do not permit stable internal fixation. Meticulous attention must be given to the handling of soft and hard tissues as well as to correction of the underlying deformity and to appropriate positioning of the joints in question. Newer techniques, such as intramedullary fixation, arthroscopic or arthroscopically assisted ankle arthrodesis, and total ankle arthroplasty, have shown some promise and warrant more extensive study.