Mean follow-up was 35.5 months (range, 4-94 months). Postoperative anteroposterior and lateral radiographs were used to evaluate maintenance of joint congruity, fracture union, remodeling, and evidence of degenerative changes. At final follow-up, grip strength of injured and contralateral hands was measured with a dynamometer (Jamar; Patterson Medical, Warrenville, Illinois). AROM and passive ROM (PROM) of the PIP joint was documented at follow-up visits. In addition, patients rated their pain on a 0-to-10 visual analog scale (VAS), with 0 representing no pain and 10 representing excruciating pain. Patients also completed a questionnaire assessing satisfaction with surgical outcome. Physical function and disability were assessed with the Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) questionnaire. Any complications, including the need for further surgeries, were documented. Pearson correlation coefficients and Student t tests (with significance set at P < .05) were used to compare outcomes.
Results
Radiographic reduction of joint dislocation was achieved and maintained in 11 of the 12 patients at a mean follow-up of 35.5 months (range, 4-94 months). Extent of joint surface involvement, based on preoperative lateral radiographs, averaged 43% (range, 25%-75%). Although no direct articular reduction was performed, remodeling of the joint surface was consistently noted at follow-up (Figure 2). Mild radiographic degenerative changes were noted at final follow-up in 4 patients, and moderate changes were noted in 1 patient. Radiographic union was achieved in all cases, and no pin-tract infections were noted.
Mean AROM of the PIP joint at final follow-up was 84° (range, 50°-110°), with patients lacking a mean of 7° of full extension and achieving mean flexion of 91°. Mean PROM was 93° (range, 75°-110°). There was no correlation between extent of articular surface involvement and ROM. Furthermore, no correlation was found between time from injury to surgery and ROM. Patients regained full grip strength in the operative hand. At final follow-up, mean grip strength was 79.4 pounds in the operative hand and 79.6 pounds in the contralateral hand, demonstrating equal grip strengths bilaterally.
Patients overall had very low levels of pain; mean VAS score was 0.64 (range, 0-3). Mean QuickDASH score was 5.7 (range, 0-30), suggesting minimal functional impairment. One patient developed a malunion of the middle phalanx fracture resulting in a rotational deformity and required corrective osteotomy. This patient’s VAS score (3) and QuickDASH score (30) were significantly higher than those of the other patients in the study. No other complications were noted by final follow-up.
A higher level of patient satisfaction was found to be directly related to length of follow-up (P < .05). Satisfaction was inversely related to higher VAS score (P < .05) and higher QuickDASH score (P < .001). Pain at work correlated with lower satisfaction level (P < .05). There was no correlation between patient satisfaction and AROM or PROM.
Discussion
The results of this study demonstrate the efficacy of EBP in the treatment of dorsal PIP joint fracture-dislocations. EBP maintained joint dislocation reduction and allowed for early mobilization, which resulted in good ROM, minimal pain, and good functional outcomes. Of note, postoperative patient satisfaction correlated with pain but not with ROM. It is possible that EBP yielded sufficient functional ROM in all patients such that improvement beyond this threshold did not lead to further improvement in satisfaction. Hume and colleagues23 found that mean PIP joint flexion of 60° is needed for activities of daily living. As mean PIP active flexion was 91° (range, 70°-105°) in the present study, it is possible that satisfaction did not correlate with ROM, as all 12 patients achieved active flexion of more than 60°. Despite the lack of correlation between ROM and satisfaction, early PIP joint mobilization is likely a key contributor to positive outcomes because of its significant role in cartilage healing.24
Postoperative ROM in the present study is consistent with that in other reports of patients with PIP joint fracture-dislocations treated with EBP.11,12,22 In a study by Inoue and Tamura,11 14 such patients had mean PIP ROM of 94° at a mean follow-up of 14 months. Viegas22 followed a series of 3 patients for a mean of 7 weeks. At final follow-up, their mean PIP arc of motion was 71°; they lacked 12° of full extension and achieved 83° of flexion. The larger PIP arc of motion (84°) found in the present study may be due to our significantly longer follow-up (35 months). Unlike us, Viegas22 noted an inverse relationship between extent of articular surface involvement and postoperative ROM. Our finding a lack of correlation may be a result of the significant amount of joint remodeling noted on follow-up radiographs.