Osseointegrated finger prostheses

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.

Comparative outcome analysis of osseointegrated reconstruction and replantation for digital amputations

The long-term outcomes of osseointegration for digital amputations are not well established, and it is not known whether osseointegration can achieve similar function and patient satisfaction to conventional surgical options such as replantation and microsurgical toe transfer. We compared the long-term outcomes after digital osseointegration and replantation. Six patients treated by osseointegration and seven patients treated by replantation were included, with median follow-ups of 8 years and 4.6 years, respectively. Outcomes were assessed using the Michigan Hand Outcomes Questionnaire, grip and pinch strength, range of motion, two-point discrimination, Semmes-Weinstein tests, Jebsen-Taylor Hand Function Test and clinical photography. Osseointegration was associated with poorer sensibility and range of motion than replantation; no other differences reached statistical significance. Long-term osseointegration is a safe and effective reconstructive option that can deliver excellent outcomes in appropriately selected patients.Level of evidence: IV.

Innovative technique for fabrication of forefinger prosthesis

Traumatic finger digit amputation may affect patient's psychology also along with a serious injury to the affected hand. Recently, advanced micro-surgical re-implantation can help save a damaged human finger that is badly injured and/or amputated. Considering its associated financial burden, a vast majority of such patients cannot afford it. For such patients, a hand/finger prosthesis may act as a blessing, boosting social performance. In the present case report, an innovative type of prosthesis finger replacement method is discussed.

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.

Osseointegrated Finger Prostheses Using a Tripod Titanium Mini-Plate

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.

Three-part mould technique for fabrication of hollow thumb prosthesis: A case report

BACKGROUND

The purpose of this article is to describe a technique which helps in fabrication of glove-type hollow thumb prosthesis using three-part mould technique.

CASE DESCRIPTION AND METHODS

Patient reported to the Department of Private dental clinic, Delhi, India with a chief complaint of missing partial left thumb and wanted to get it replaced. A complete clinical hand examination was carried out, which revealed a residual stump of 1 cm length. After ensuring the medical conditions to be normal, fabrication of hollow thumb prosthesis was planned using three-part mould technique.

FINDINGS AND OUTCOMES

The prosthesis delivered to the patient was highly retentive because of its glove-type retention and lighter weight; feedback from the patient regarding retention was excellent. The prosthesis was aesthetically pleasing because of its excellent colour matching with the skin, and each and every part of the prosthesis could be colour customized because of easy retrieval of the third part of the mould, as well.

CONCLUSION

A technique of hollow thumb prosthesis has been described in this article which helps in reduction in weight, easy packing of silicone material into the mould and easy colour customization at the knuckles area of the dorsal and ventral aspect of the prosthesis.

CLINICAL RELEVANCE

This three-part mould technique helps to fabricate hollow prosthesis which increases retainability and at the same time allows easy packing of silicone material and easy colour customization at the knuckles area of the prosthesis.

Secondary Interventions for Mutilating Hand Injuries

Care of the reconstructed hand following mutilating injury is akin to the care of a vintage car. Its mechanisms are delicate, spare parts are limited, touch-ups are required often, and a major overhaul is indicated rarely. Secondary interventions are indicated for completion of staged primary procedures, management of complications, targeted improvement of function, and enhancement of appearance of the reconstructed hand. The approach to secondary reconstruction depends on the patient's age, and vocational and recreational requirements. It is also influenced by the constant evolution of surgeons' reconstructive philosophy, experience, and technology.

Prosthetic rehabilitation of a patient with finger amputation using silicone material

AIM

Finger and partial finger amputations are commonly due to traumatic injuries; digit loss may also be attributed to congenital malformations and disease. Finger prostheses are difficult to fabricate as they demand both aesthetic and function. When dealing with these types of prostheses, the only method of gaining successful retention is to sleeve the remnant stump with thin silicone.

CASE DESCRIPTION AND METHODS

A 28-year-old man reported with a chief complaint of unaesthetic look due to amputated ring finger of left hand. In this case, the remnant stump was missing, the adjacent ring finger was splinted and an adhesive retained prosthesis instead of ring retained or glove-on prosthesis was planned. The retention was achieved by extending the prosthesis to palmar crease.

FINDINGS AND OUTCOME

This article describes the rehabilitation of a finger with prosthesis, which is simple to construct, aesthetic, retentive and easy to maintain. The prosthesis thus fabricated merged with the adjacent tissues providing desired aesthetics and psychological boost to the patient.

CONCLUSION

Final prosthesis was found with adequate retention. The patient was satisfied with the aesthetic of the prosthesis.

CLINICAL RELEVANCE

Because of the missing residual stump, functional limitations were also there. This clinical report describes a technological process of designing and manufacturing a silicone rubber prosthesis for a patient who has a finger loss caused due to trauma.

Morphometrics of the human thumb metacarpal bone: interest for developing an osseointegrated prosthesis

INTRODUCTION

Amputation of the thumb presents a serious insult to the hand and diminished quality of life for a patient physically, vocationally, and possibly psychologically. The aim of this study was to define the geometry of the thumb metacarpal in order to help create a standardized set of transcutaneous osseointegrated prostheses to treat patients who have suffered amputation of the thumb at the level of the metacarpophalangeal joint.

MATERIALS AND METHODS

A total of 80 metacarpals from 46 cadavers were studied. All soft tissues were removed and the thumb metacarpals were imaged using computed tomography. Three-dimensional models were constructed using images from the coronal, sagittal, and axial planes. Using HyperMesh™ CAD software, the bones were analyzed for overall length, radius of curvature, medullary canal diameter, cortical thickness, and distance to the isthmus, defined as the narrowest portion of the intramedullary canal.

RESULTS

The average length of the first metacarpal was 47.6 mm (±3.3 mm, 39.2-56.9 mm). The average radius of curvature was 55.5 mm (±10.7 mm, 33-78.9 mm). Inner bone diameter, measured in two axes, was 10.5 mm (±1.3 mm, 5.4-18.7 mm) for the major axis and 7.7 mm (±0.9 mm, 4.3-17.8 mm) for the minor axis. The average cortical thickness was 1.4 mm (±0.3 mm, 0.7-3.1 mm). The distance to the center of the isthmus from the distal end had an average length of 21.3 mm (±1.9 mm, 17-25 mm).

CONCLUSIONS

Using these findings a standardized set of intramedullary stems can be developed as a base for a transcutaneous osseointegrated prosthesis, helping to create a reliable method for treating patients with amputated thumbs.

Osseointegrated silicone finger prosthesis using dental implants: a renovated technique

AIM AND BACKGROUND

In clinical practice, we come across patients with traumatically amputated or congenitally missing partial or complete fingers that can be restored using microsurgical replantation or transplantation procedures. However, in some cases this might not be possible due to systemic or local factors and the lost or missing part has to be replaced prosthetically to offer psychological and functional wellbeing. These prostheses can be constructed with various materials like acrylics or silicone retained with the help of auxiliary aids. However, these prostheses cause some hindrance in performing functions like writing, typing, etc. The aim of the present trial was to ameliorate the existing design of implant supported finger prosthesis.

TECHNIQUE

Distal phalange of middle finger replaced with implant supported silicone finger prosthesis is modified by utilizing a metal framework to support silicone material to improve rigidity while working.

CONCLUSION AND CLINICAL SIGNIFICANCE

We could achieve a good function, esthetics and tactile sensibility with this modified design. Whenever, feasible this design can improve the performance and patients feel a deep sense of satisfaction and improved self-esteem with this modified prosthesis.

Fabrication of a functional finger prosthesis with simple attachment

Finger prosthesis is more acceptable by the patient when it allows some of the movement in the prosthesis along with the restoration of a natural appearance to the lost structures of the patient. This article describes a custom-fabricated, custom-colored prostheses made from silicone elastomers with a simple attachment to make the prosthesis functional to imitate some of the movement.

One- vs two stage surgery technique for implant placement in finger prosthesis

BACKGROUND

The loss of the finger can lead to psychological problems. Although several reconstructive techniques may exist, the use of osseous-integrated implants to anchor digital prosthesis presents a suitable alternative for the amputation of finger. The surgery for implant placement has initially been described as a two-stage technique. However, no study in the literature has attempted to compare this technique with one-stage technique and stated a clear superiority technique in the implant retained finger prosthesis.

METHODS

This article describes two cases of digital amputation as a result of accident; a 45-year-old female whose second finger of right hand was lost and a 25-year-old male patient with amputation of the first finger of right hand.

RESULT AND CONCLUSION

One-stage implant placement technique for implant retained finger prosthesis is a reliable, safe and efficient option that allows a good result in a significantly lower operating time and hospital visits compared to the two-stage technique. It could therefore, be considered as good option for implant retained finger prosthesis.

Fitting very short finger stumps with silicone prosthesis: a nonsurgical method

BACKGROUND AND AIM

The fitting of short finger stumps with silicone prosthesis is a challenge because of the suboptimal finger-prosthesis contact due to length and distal tapering of digital stumps. The purpose of this report was to describe and evaluate the Micropore(™)-polyvinyl chloride tube technique for fitting short finger stumps.

TECHNIQUE

For a total of 10 patients, short finger stumps were fitted using the technique. A short length of polyvinyl chloride tube, trimmed and contoured to fit, was secured on the distal stump tip with Micropore tape. The prosthesis was worn over the polyvinyl chloride tube extension. Three different fitting methods were evaluated: fitting with and without the Micropore-polyvinyl chloride tube technique, and with the use of skin adhesive on the stump.

DISCUSSION

All patients achieved a very secure prosthetic fit with the Micropore-polyvinyl chloride tube technique. No incidences of prosthesis slippage were reported at the longest follow-up of 30 months. The Micropore-polyvinyl chloride tube technique is an effective method for fitting short finger stumps.

Esthetic, functional, and prosthetic outcomes with implant-retained finger prostheses

BACKGROUND

Traumatic amputation of fingers results in a serious impairment of hand function and affects the psychological status of the patients. The implant-retained finger prostheses are an alternative treatment. The aim of this case report is to represent the use of osseointegrated implants for retention of finger prostheses in a patient with amputated thumb and index finger.

CASE DESCRIPTION AND METHODS

Dental implants were placed in the residual bone of the fingers using two-stage surgery. Custom-made attachments were used to provide retention between implants and silicone prostheses. Prosthetic fingernails were made of composite resin material.

FINDINGS AND OUTCOMES

After 6 months, implants were clinically successful, and the patient was satisfied with the appearance and the function of the prostheses. The complications of broken prosthetic nail and mild discoloration were observed.

CONCLUSION

Reconstruction of amputated fingers with implant-retained prosthesis is a worthwhile treatment providing esthetic, functional, and psychological benefits, although some complications might be experienced. Clinical relevance Implant-retained finger prostheses are an acceptable treatment modality for patients with amputated fingers. Evaluating implant prognosis, functional results and prosthetic results of the patients are necessary to address the benefits and complications of the treatment.

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.

Osseocutaneous integration of an intraosseous transcutaneous amputation prosthesis implant used for reconstruction of a transhumeral amputee: case report

Exoprosthetic replacement with an artificial limb is the main option for reconstruction after traumatic amputation of an upper limb. Direct skeletal attachment using an osseointegrated implant improves the ease of fixation of the exoprosthesis to the amputation stump. We now report the use of an intraosseous transcutaneous amputation prosthesis that is designed to achieve osseocutaneous integration. Osseocutaneous integration differs from osseointegration because the aim is to create a stable interface among the implant, the bone, and the soft tissues. This reduces the risk of soft tissue infection and troublesome discharge, which are problems encountered with current osseointegrated implants that focus largely on the bone-implant interface. We describe our experience with an intraosseous transcutaneous amputation prosthesis in a case of transhumeral amputation with 2 years of follow-up.