Four-corner fusion: Comparing outcomes of conventional K-wire-, locking plate-, and retrograde headless compression screw fixations.

Purpose: Several operative approaches and various implants for osseous fixation have been described to achieve four-corner fusion of the wrist. Given the discordance and to aid in further standardizing the technique, this study directly compares the outcomes of K-wire, fusion plate, and headless retrograde compressive screw fixations to achieve four-corner arthrodesis.

Methods: Sixty-four patients underwent four-corner fusion over a period of 5 years and were reviewed retrospectively. Twenty-one patients underwent bone fixation with conventional K-wires, 26 with locking plates, and 17 patients were treated by headless retrograde compressive screw fixations. Patients of the different groups were comparable regarding age, sex, hand dominance, and stage of disease.

Results: All study groups showed significant improvements in grip strength, decrease in pain (NRS) at rest and with activity, range-of-motion of the wrist, and wrist function (measured by the DASH-score). When evaluating the three groups amongst each other, overall complication and nonunion rates were low and revealed no significant differences between the groups of patients. However, regarding postoperative NRS at activity, dorsal flexion, and DASH-scores, the "screw" group showed significantly better results than the "wire" group.

Conclusion: The results show that all examined techniques of four-corner fusion can improve wrist function when compared to preoperative baseline (NRS at rest and activity, postoperative DASH-scores). However, headless retrograde compressive screw fixation had significant better results regarding pain relief (NRS) at activity and postoperative DASH-scores.