[Improved fixation of finger prostheses by means of intramedullary titanium anchors and magnets]

Osseointegrated Metallic Implants for Finger Amputees: A Review of the Literature

Digital trauma amputations and digital agenesis strongly affect the functionality and aesthetic appearance of the hand. Autologous reconstruction is the gold standard of treatment. Unfortunately, microsurgical options and transplantation procedures are not possible for patients who present contraindications or refuse to undergo transplantation from the toe (e.g. toe‐to‐thumb transplantation). To address these issues, osseointegrated finger prostheses are a promising alternative. The functional assessments registered during follow‐up confirmed the promising outcomes of osseointegrated prostheses in the treatment of hand finger amputees. This review outlines (a) a detailed analysis of osseointegrated finger metallic components of the implants, (b) the surgical procedures suggested in the literature, and (c) the functional assessments and promising outcomes that demonstrate the potential of these medical osseointegrated devices in the treatment of finger amputees.

Novel approaches to fitting and implanting finger and nail prosthetics

PURPOSE

This work presents unique designs for prosthetic restoration of the distal finger. We first discuss fitting a prosthetic nail in order to restore the cosmetic deficit caused by partial or complete nail injury. This concept is inspired from snap fit and lanced sheet metal technology. We also discuss new approaches to designing and fitting a full fingertip prosthetic with a special suspension and a socket for more complete cosmetic fingertip restoration.

METHODS

The designs utilize the compliance and higher strain level of hinges to fit the prosthesis with either the residual nail or to the distal-most aspect of the amputated fingertip. These techniques require preparation of the residual nail to match the fabricated nails well as design of a snap fit nail prosthetic. The socket and suspension design of the full fingertip prosthetic is formed with a spring shape and has an open end to allow proper molding, fit, and suspension.

RESULTS

The introduced approaches simplify the assembly steps and propose unique, cosmetically appropriate, and potentially less irritating prosthetic options compared to what has been previously used. The socket of the finger has an ability to expand and can be worn on any stump size.

CONCLUSION

Low cost, fewer parts, ease of assembly and user friendly are the main attributes of the introduced designs. Future work to finalize these designs and trial them in humans is needed.

Osseo integrated finger prosthesis with a custom abutment

One of the most regularly encountered forms of partial hand loss causing physical, psychosocial and financial burden to an individual is the finger amputation followed by trauma. The prosthetic rehabilitation of amputated finger is a good treatment option, when compared to all other means of complex and unaffordable options. Osseointegrated implant retained silicone finger prosthesis with innovative prosthetic designs can provide the patient a life changing experience.

Long-term outcomes of osseointegrated digital prostheses for proximal amputations

This paper presents outcomes after 13, 4, and 3½ years in three digital amputees treated with osseointegrated prostheses. One had prosthetic replacement of the index and middle fingers at the PIP level. The second had four fingers replaced at the PIP level, but only three prostheses were retained. The third had a thumb replacement at the MCP level. All patients scored their reconstructed hand highly in terms of appearance and frequency of use. The first and third patients rated the function of the reconstructed hand as similar to the normal hand, and this was confirmed by the Jebsen Test, but the second patient had poor function. All patients could detect pressure and vibration through their prostheses, although grip and pinch strengths were weaker in all three. All three also experienced some pain in the implanted fingers. This study identifies osseointegration as a stable long-term reconstructive option.

Osseointegrated finger prostheses

Amputation of a digit can lead to functional and psychological problems and patients can benefit from digital prostheses. Unfortunately, standard prostheses are often unstable, particularly when fitted over short amputation stumps. Prosthesis fixation by osseointegration is widely used in oral and extraoral applications and may help avoid the problem of instability. This paper reports the results of four patients with five finger amputations who were treated with osseointegrated implants to attach finger prostheses. One implant failed to osseointegrate and the procedure was abandoned. Three patients were successfully treated to completion of three finger prostheses and are extremely satisfied with their outcomes, both cosmetically and functionally, with osseoperception reported by all three patients.