Session V - Upper Extremity

Displaced Intra-Articular Fractures of the Distal Radius: Long Term Functional Outcome in Young Adults

Louis W. Catalano, III, MD, R. Jeffrey Cole, MD, Richard H. Gelberman, MD, Louis A. Gilula, MD, Joseph Borrelli, Jr., MD

Washington University School of Medicine, St. Louis, Missouri, USA

Studies on fractures of the distal radius have noted a correlation between residual articular displacement and the incidence of post-traumatic arthritis. In an effort to improve clinical outcomes following intra-articular fractures, several authors have recommended that operative reduction of distal radius fracture fragments be carried out when there are articular incongruities greater than one or two millimeters. There have been few long-term studies that have correlated the functional radiographic outcomes following displaced intra-articular distal radius fractures to determine whether this clinical approach is effective in preventing degenerative arthritis and minimizing patient morbidity. The purpose of this study was to determine long-term functional and radiographic outcomes in a series of young adults (<45 yrs) with displaced intra-articular fractures of the distal radius treated with operative reduction and stabilization in the acute setting.

Between 1986 and 1990, fifty-one consecutive patients with fifty-two intra-articular fractures of the distal radius underwent operative treatment. Patients who had isolated dorsal or palmar articular margin fractures involving less than twenty percent of the joint surface, isolated radial styloid process fractures distal to the scaphoid facet, ipsilateral hand or carpal injuries, or inadequate or destroyed perioperative radiographs were excluded from the study. Twenty-six fractures in twenty-six patients met the inclusion criteria. Twenty-one patients returned for physical examination, imaging evaluation (plain radiography and computerized tomography) and completion of a validated musculoskeletal functional assessment questionnaire. Range of motion of both wrists, measured in three planes (flexion-extension, radio-ulnar deviation, and pronation-supination), grip strength, lateral key pinch strength and three-point pinch strength were measured. The scaphoid shift and the ulnocarpal impaction test were performed and distal radioulnar joint (DRUJ) stability was tested.

At follow-up, all patients underwent a posterior-anterior, lateral, oblique and ulnar deviation radiographic evaluation of the affected side, as well as a PA and lateral radiograph of the uninvolved wrist with standardized positioning of the forearm. Measurements of radial length, radial inclination, volar tilt, and ulnar variance were made using standardized methods. Articular incongruity (gap and step) was quantified using the arc method of measurement. The extent of comminution and the presence or absence of an ulnar styloid fracture was also recorded on each preoperative radiograph.

CT scans were obtained in all twenty-one patients. Two millimeter thick continuous axial, sagittal, and coronal images were obtained by direct scanning. Post-traumatic arthrosis of the radiocarpal joint and distal radioulnar joint was graded using objective findings on plain radiographs and CT images.

The mean follow-up for these twenty-one patients was 7.1 years. Inverse correlations were observed between health related quality of life as measured by the MFA and maximum gap and step displacement at the time of osseous union, as well as maximum fracture gap and step deformity measured by CT at follow-up. This relationship was statistically significant for the total MFA score and maximum gap displacement, but approached statistical significance for the total MFA and maximum step displacement, and for hand and fine motor skills score and both maximum gap and step displacements. With regard to the CT findings, this relationship was found to be statistically significant for the total MFA score, for the fine motor skills score and for the maximum step displacement. Maximum gap displacement and the total MFA score approached statistical significance, while the correlation between maximum gap displacement and the fine motor skills score was not statistically significant. A statistically significant difference was noted between the involved and uninvolved sides for wrist flexion, wrist extension, forearm pronation, forearm supination, radial and ulnar deviation as well as for grip strength, lateral key pinch strength, and three-point pinch strength (p<.05 for each comparison). There were no statistically significant correlations between maximum step and gap displacement and the measures of strength at final follow-up. A statistically significant difference between the involved and the uninvolved wrist was noted for radial length, radial angle, and ulnar variance (p <.05 for each comparison).

Using the modified system of Knirk and Jupiter, five wrists had no arthrosis, nine had grade I arthrosis, seven had grade II, and none had grade III arthrosis. Based on the CT images, five had no arthrosis, four had grade I arthrosis, twelve had grade II and none had grade III arthrosis. The minimum thickness of the remaining joint space was measured within the scaphoid and lunate facets; using these data, five wrists had no arthrosis, six had grade I arthrosis, nine had grade II, and one had grade III arthrosis.

At a minimum follow-up of 5.5 years (mean: 7.1 years), seventy-six percent of wrists in this series developed radiocarpal arthrosis that was evident on plain radiographs and CT images. However, the functional outcome data obtained in this study were good to excellent, even in those patients with radiographic evidence of radiocarpal and/or distal radioulnar arthrosis, or ulnar styloid nonunion. Only one patient changed jobs as a result of the injury and fourteen of the patients had the best possible functional score on the hand and fine motor subscale of the MFA. Surprisingly, the results from the Musculoskeletal Function Questionnaire found the largest self-reported impairments in function among those patients with the smallest residual displacements.

The results demonstrate a strong correlation between residual articular incongruity and post-traumatic arthrosis. The MFA questionnaire administered at final follow-up did not reveal poor results, however, for patient based functional outcome. It is unclear whether longer follow-up will reveal a correlation between residual articular incongruity at fracture healing and functional outcome, or whether the natural history of such fractures undergoing open treatment is not as poor as earlier radiographic outcome studies have suggested.

Based on these results, we advocate that the goal of treatment continue to be anatomical restoration of the articular surface to avoid radiocarpal arthosis and base the performance of operative procedures on the presence of signifcant symptoms or on disabling loss of function rather than on the basis of radiographic evidence of radiocarpal arthrosis.