Osseointegrated Finger Prostheses Using a Tripod Titanium Mini-Plate

Abstract

Background: Digital amputation is a common upper extremity injury and can cause significant impairment in hand function, as well as psychosocial stigma. Currently, the gold standard for the reconstruction of such injuries involves autologous reconstruction. However, when this or other autologous options are not available, prosthetic reconstruction can provide a functionally and aesthetically viable alternative. This study describes a novel technique, known as a tripod titanium mini-plate, for osseointegrated digit prostheses, and reviews the outcomes in a set of consecutive patients.

Methods: A retrospective review of patients who underwent 2-stage prosthetic reconstruction of digit amputations was performed. Demographic information, occupation, mechanism of injury, number of amputated fingers, and level of amputation were reviewed. Functional and aesthetic outcomes were assessed using the quick disabilities of the arm, shoulder, and hand (Q-DASH) scale and a visual analog scale (VAS) score, respectively. In addition, complications during the postoperative period were recorded.

Results: Seven patients were included in this study. Their average age was 29 years. Five patients had single-digit amputations and 2 patients had multiple-digit amputations. Functional and aesthetic outcomes were assessed using the Q-DASH score (average, 10.4) and VAS score (average, 9.1), respectively. One episode of mild cellulitis was seen at 24 months of follow-up. However, it was treated successfully with oral antibiotics. No other complications were reported.

Conclusions: When autologous reconstruction is not suitable for digit reconstruction, prosthetic osseointegrated reconstruction can provide good aesthetic and functional results. However, larger series with longer-term follow-up are required in order to rule out the possibility of other complications.

Keywords: Amputation; Osseointegration; Outcome assessment; Prostheses.

Fig. 1. Mini-plate design

Tripod titanium mini plate with 3 anchoring screws and a tip magnet device.

Fig. 2. Mini-plate placement

(A) Adjustment of the titanium tripod to the distal phalangeal stump. (B) Soft tissue closure of the phalangeal stump with exposure of the anchoring magnet.

Fig. 3. Postoperative hand X-ray

(A) Anteroposterior and (B) lateral hand X-rays 6 months after surgery show no lucency around the plates and screws, which is associated with adequate osseointegration of the prostheses at the distal phalangeal stump.

Fig. 4. Insertion and color match of prostheses

(A) Postoperative picture of Patient 1 with the right index finger prostheses prior to insertion with exposure of magnetic tip. (B) Fitting of the right index finger prostheses to demonstrate color and length match. (C) Patient demonstrating fitting of pen into the right hand (writing) as a functional outcome.

Fig. 5. Patient with amputation of multiple digits

Patient 2. (A) Multiple digit amputation (digits 2, 3, and 4) of the right hand. (B) Three-dimensional reconstruction of the missing digits. (C) Dorsal and (D) volar aspects of the right hand after the prostheses were placed.