Osseointegrated Finger Prostheses Using a Tripod Titanium Mini-Plate

Bactericidal Activity of Silver-Doped Chitosan Coatings via Electrophoretic Deposition on Ti6Al4V Additively Manufactured Substrates

Prosthetic reconstruction can serve as a feasible alternative, delivering both functional and aesthetic benefits to individuals with hand and finger injuries, frequent causes of emergency room visits. Implant-related infections pose significant challenges in arthroplasty and osteosynthesis procedures, contributing to surgical failures. As a potential solution to this challenge, this study developed a new class of silver (Ag)-doped chitosan (CS) coatings via electrophoretic deposition (EPD) on osseointegrated prostheses for infection therapy. These coatings were successfully applied to additively manufactured Ti6Al4V ELI samples. In the initial phase, the feasibility of the composite coating was assessed using the Thermogravimetric Analysis (TGA) and Attenuated Total Reflection (ATR) techniques. The optimized structures exhibited impressive water uptake in the range of 300-360%. Codeposition with an antibacterial agent proved effective, and scanning electron microscopy (SEM) was used to examine the coating morphology. Biologically, CS coatings demonstrated cytocompatibility when in direct contact with a fibroblast cell line (L929) after 72 h. When exposed to the Staphylococcus epidermidis strain (ATCC 12228), these coatings inhibited bacterial growth and biofilm formation within 24 h. These findings underscore the significant potential of this approach for various applications, including endoprostheses like hip implants, internal medical devices, and transcutaneous prostheses such as osseointegrated limb prosthetics for upper and lower extremities.

A biomechanical study of osseointegrated patient-matched additively manufactured implant for treatment of thumb amputees

Thumb amputations leads to 50 % loss in hand functionality. To date, silicone vacuum prosthesis and autologous transplantation are the most adopted treatment solutions: nevertheless, vacuum prostheses lack in stability and cause skin issue and surgical treatment is not always accepted by patients. Osseointegrated implants were demonstrated to enhance stability, restore osseoperception and increase the time of prosthesis use. Thumb amputations present varying stump sizes: a standard size implant cannot address specificity of each patient, while a patient matched solution can meet surgeon requirements, by geometrical features of implant. The fixture presented in the current paper is the first additively manufactured patient matched osseointegrated implant for the treatment of thumb amputees. The current work aims to verify and validate a predictive finite element model (FEM) for mechanical strength of the presented fixture. FEM was demonstrated to correctly evaluate the mechanical strength of patient matched device. Minimum strength requirements were calculated in different core diameters: FEM were experimentally validated. Safety factor of 1.5 was guaranteed. Finally, considerations on performance of the prototype were carried out by means of insertion tests in Sawbones and axial pull-out force assessment. Cadaver tests to evaluate the entire procedure and production process are ongoing.

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.

The stigma of digital amputation: a survey of amputees with analysis of risk factors

The purpose of this study was to quantify the stigma associated with digital amputation and examine factors associated with it. One hundred and sixty-four digital amputees completed the Neurological Quality of Life-Stigma questionnaire and a battery of Patient-Reported Outcome Measurement Information System instruments. Multivariable analysis examined factors associated with stigma experience. The mean observed stigma score of 47 (SD 8, range 36-64) was similar to the mean value of the normal population. Younger age, a worker's compensation claim and depression were each independently associated with a more severe experience of stigma after digital amputation. Socioeconomic variables, anatomical details and mechanism of injury were not independently associated with stigma. Digital amputation is not highly stigmatizing overall. Surgeons should consider referring at-risk patients to a mental health provider for support during the coping and adjustment process after amputation.Level of evidence: III.

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.