The Effect of Ligament Injuries on Outcomes of Operatively Treated Distal Radius Fractures
Various authors have documented wrist ligament injuries in patients with distal radius fractures (DRFs). We conducted a study to determine whether scapholunate interosseous ligament (SLIL), triangular fibrocartilage complex (TFCC), or chondral injuries directly assessed with arthroscopy predict DRF outcomes. Forty-two patients who underwent open reduction and internal fixation of DRFs were enrolled in the study. At time of fracture surgery, patients were arthroscopically evaluated for SLIL and TFCC injuries and chondral surface damage. The Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire was the primary outcome measure at 1 year. Analysis of variance was performed to evaluate for correlations between ligamentous/chondral injuries and DRF outcomes. Forty-five percent of patients had SLIL injuries, 50% had TFCC injuries, and 29% had articular cartilage injuries. There were no significant differences in DASH scores among the different injury groups and no significant differences in terms of secondary outcomes. SLIL and TFCC injuries occur in more than 70% of patients with operatively treated DRFs. These injuries appear not to have major negative effects on DRF outcomes up to 1 year after surgery.
All DRFs underwent internal fixation with a locked volar plate. When necessary, K-wires and/or a locked radial column plate was used for additional fixation. External fixation was not used. The postoperative protocol began with a dorsal wrist splint placed on the patient in the operating room and worn for 10 to 14 days. At the first postoperative visit, the patient received a removable splint that was to be worn at all times except during showers, therapy, and home exercises. Occupational therapy, initiated the week of the first postoperative visit, consisted of active and passive ROM exercises. At 6 weeks, the splint was removed and strengthening initiated.
Outcome Measures
Our primary outcome measure was the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire at 1 year.15 Secondary outcome measures were visual analog scale (VAS) pain rating, ROM, and radiographic measurements. Patients returned for evaluation 2, 6, 12, 24, and 52 weeks after surgery. At each follow-up visit, the DASH questionnaire and the pain VAS were administered, and ROM and strength were measured. Patient-reported pain was recorded on a standard VAS and measured on a scale from 0 (no pain) to 10 (worst possible pain). Wrist flexion and extension and radioulnar deviation were assessed with a goniometer. Forearm supination and pronation were assessed with the elbow flexed 90° at the patient’s side. Grip strength was measured with a calibrated Jamar dynamometer (Sammons Preston Rolyan), and lateral pinch strength was measured with a hydraulic pinch gauge (Sammons Preston Rolyan). The average of 3 trials for both hands was recorded for all strength measurements.
Radiographs were obtained on presentation. When appropriate, the fracture was manually reduced with a hematoma block, and postreduction radiographs were obtained. Then, radiographs were obtained at each postoperative visit until union. Radial height, radial inclination, tilt, and ulnar variance were measured on preoperative and postoperative radiographs according to standard methods.16 Radiographs were used to classify the fracture patterns according to the AO/ASIF (Arbeitsgemeinschaft für Osteosynthesefragen/Association for the Study of Internal Fixation) classification. Union was determined by radiographic healing, absence of tenderness to palpation, absence of pain with motion, and continued functional improvement.
Data Analysis
To evaluate for relationships between patient injury parameters and outcome measures, we used a 1-way analysis of variance seeking statistically significant differences between groups. Patients were divided into 4 groups: no ligament injuries; isolated SLIL injuries; isolated TFCC injuries; and both SLIL and TFCC injuries. These injury classification categories were then evaluated independently against our chosen outcome measures, which included DASH and VAS pain scores, ROM, and grip/pinch strength.
To determine the optimal sample size, we performed a power analysis to estimate the number of patients required to detect a clinically significant difference in DASH scores at 1 year among the 4 groups. According to the literature, standard deviations of DASH scores in healthy volunteers range from 10 to 15,17 consistent with values found in other recent trials of patients with DRFs.18 The recent literature on DASH construct validity has established a DASH score difference of 19 as representing a disability change being “much better or much worse.”19 As such, power analysis for a 1-way analysis of variance among 4 categories, detecting a DASH score difference of 19 with a standard deviation ranging from 10 to 15, would require 28 to 60 patients to detect a difference with an α of 0.05 and a power of 0.8.
In addition, radiographic parameters at time of injury were compared with injury characteristics to assess for significant relationships. Multivariate linear regression analysis was performed to evaluate radial height, radial inclination, and volar tilt as possible predictors of SLIL injury, TFCC injury, and chondral surface damage. A statistically significant result was defined as a correlation with P < .05.
Results
Of the 42 patients included in the study, 11 (26%) had no ligament injuries, 10 (24%) had isolated SLIL injuries, 12 (29%) had isolated TFCC injuries, and 9 (21%) had injuries to both the SLIL and the TFCC. In addition, in 12 patients (29%), the articular cartilage had visible damage (Table 1). 
In all patients, bony union occurred. After union, 1 patient underwent hardware removal for hardware-related pain. The same patient had a dorsal ulnar cutaneous nerve neurolysis at the ulnar styloid fixation site. Another patient developed a partial extensor pollicis longus tear from a prominent dorsal screw tip.
All patients returned for their 2- and 6-week follow-ups. At 1 year, 30 patients (71%) returned for follow-up, 11 could not be contacted, and 1 was removed because of an olecranon fracture from a subsequent fall.
Regarding the primary outcome measure, mean DASH score at 1-year follow-up was 30.8 for the group without injuries, 10.8 for the group with SLIL injuries, 14.7 for the group with TFCC injuries, and 21.9 for the group with SLIL and TFCC injuries (Table 2). 
Radiographic parameters were restored to acceptable limits in all patients (Table 3). 
