A Novel Technique With Buttress Plating for Comminuted Base Fractures of the Proximal Phalanx

Background: Extra-articular but severely comminuted distal basal fractures of the proximal phalanx (PP) are rarely reported. Therefore, the aim of this study was to achieve proper union and desirable outcomes using low-profile locking plates/screws. We introduced our own surgical approach and reported the clinical/radiographic outcomes via retrospective case series.

Methods: Thirty-eight patients diagnosed with comminuted basal fracture of the PP were admitted between January 2014 and December 2020. Nineteen of these patients met the inclusion/exclusion criteria and were investigated in this retrospective study. Focusing only on preventing the volar tilt/collapse of the articular cartilage from the vertical position due to comminuted metaphysis, such as the "buttress concept by locking plate," the defect was filled with bone grafts. Meticulous repair of the incised central tendon effectively stabilized it by tightening the sagittal band and capsule of the metacarpophalangeal joint. It also acted as an envelope with proper sealing to minimize the loss of grafted bone materials.

Results: Among the 19 patients, the mean patient age was 58.94 years, and the male/female ratio was 6:13. The mean follow-up period was 3.15 years, and the mean BMD was -0.15. Complete union was achieved after a mean of 9.63 weeks, without complications requiring secondary intervention. Two patients complained of skin lesion associated with PDS suture material, but this material spontaneously resolved by 4 weeks postoperatively. The mean extension lag at the proximal interphalangeal joint was 3.68 degrees, and the total active range of motion (TAM) was 256.38 degrees. Among the 19 patients, 6 were categorized as having a "good" modified Belsky classification, and the other patients all had an "excellent" classification. The mean articular-dorsal cortex angle was 85 ± 3.33 degrees at the final follow-up, which was slightly less than the normal value with statistical difference (P < 0.05); however, it did not correlate with the TAM statistically (r = 0.126, P = 0.608). Clinical outcomes were also satisfactorily evaluated using the VAS and DASH scores.

Conclusions: A low-profile locking plate is an effective option for extra-articular, severely comminuted basal fractures of the PP using the buttress concept in terms of clinical outcomes, such as finger movement and proper union.

Level of evidence: Level IV, Retrospective case series.