A Systematic Review of Surgical Characteristics and Adverse Events of an Active, Transcutaneous Bone Conduction Device.

OBJECTIVE: A new, active transcutaneous bone conduction device (BCD) was FDA-approved in 2019 in the USA. This systematic review sought to evaluate early outcomes associated with Osia implantation. METHODS: A systematic review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Four databases were reviewed: PubMed, Scopus, Cochrane CENTRAL, and CINAHL. Studies were included if they described audiometric, surgical characteristics/complications, or adverse events associated with the Osia BCD. Exclusion criteria: non-English language studies, animal investigations, reviews/meta-analyses, case reports, database studies. RESULTS: Eighteen studies with 336 patients were included. Mean age at implantation was 37.9 years. About 79.5% of patients had MHL/CHL and 19.5% had SSD/SHL. Mean operative time was 71.6 minutes. Mean PTA gain from unaided conditions was 35.4 dB. Mean functional gain at high frequency (6 kHz and above) from aided conditions was 16.1 dB. Mean improvement in speech recognition thresholds was 19.1 dB from unaided conditions. Adverse events (all types) were reported in 20.1% of cases. Across all studies, the postoperative infection rate was 5%. About 2% of patients reported magnet retention issues. About 1.65% of cases were complicated by hematomas. CONCLUSIONS: Under systematic literature review, the Osia BCD has been associated with low complication rates, relatively short operative times, and good audiometric and speech outcomes, notably high frequency gain >6 kHz. More advanced audiometric outcome reporting remains limited and audiometric data and patient reported outcome measures were reported heterogeneously.

A MAUDE database analysis on the new generation of active bone conduction hearing implants.

Objective: To analyze medical device reports (MDR) submitted to the Food and Drug Administration's (FDA) Manufacturer and User Device Facility Experience (MAUDE) database to identify adverse events (AEs) in patients implanted with novel active bone conduction hearing implants (BCIs). Methods: We conducted a search of the FDA MAUDE database on the newest generation of BCIs. Data were collected concerning device malfunctions, patient injuries, factors triggering these incidents, and the subsequent actions taken. Results: In total, 93 (16.7%) device malfunctions and 465 (83.3%) patient injuries with 358 subsequent interventions were identified, resulting in 558 AEs. Although the absolute AE number per device cannot be identified, the following trends were detected: Among the 494 AEs associated with OSI200, 55 (11.1%) reported device malfunctions and 454 (88.9%) cited patient injuries. Out of the 64 AEs linked to BCI602, 28 (59.4%) were associated with malfunctions, whereas 26 (40.6%) involved patient injuries. The most frequently reported particular AEs for the OSI200 were infection (n = 171, 34.6%), extrusion of the device (n = 107, 21.7%), and pain (n = 51, 10.3%). Conversely, no device output (n = 20, 31.3%) and loss of osseointegration (n = 7, 10.9%) were the most reported AEs for the BCI602. Various AEs led to 214 explanations and 77 revision surgeries. Sixty-seven AEs reported conservative treatment. Conclusion: The current study provides an overview of the most commonly reported complications with new active BCIs. Although providing an overview, given the limitations of the FDA MAUDE database, our results have to be interpreted with caution. Level of Evidence: 4.

Feasibility of predicting changes in gait biomechanics following muscle strength perturbations using optimal control in patients with transfemoral amputation.

Bone-anchored limbs (BALs) are socket prosthesis alternatives, directly fixing to residual bone via osseointegrated implant. There is a need to quantify multi-level effects of rehabilitation for transfemoral BAL users (i.e. changes in joint loading and movement patterns). Our primary objective was determining feasibility of using optimal control to predict gait biomechanics compared to ground-truth experimental data from transfemoral BAL users. A secondary objective was examining biomechanical effects from estimated changes in hip abductor muscle strength. We developed and validated a workflow for predicting gait biomechanics in four transfemoral BAL users and investigated the biomechanical effects of altered hip abductor strengths.

Effects of bone anchored maxillary protraction on patients with unilateral cleft lip/palate or isolated cleft palate and hypoplastic maxilla: a 6-year follow-up case control study.

OBJECTIVES: To evaluate the effects of bone-anchored maxillary protraction (BAMP) treatment and longterm stability in growing cleft lip and palate and isolated cleft palate (CLP/CP) patients with mild maxillary hypoplasia and to compare maxillary growth patterns of BAMP-treated patients to matched control CLP/CP patients. MATERIALS AND METHODS: Ten patients with CLP/CP were treated with BAMP; they were compared to the maxillary growth pattern of 10 age-matched cleft control patients with no maxillary protraction treatment, who later received surgical Le Fort I maxillary advancement after the growth period. The assessment of maxillary growth and the occlusion started at mean 8 years of age and continued until mean 18 years of age. RESULTS: The use of BAMP orthopedic traction changed the growth pattern of mild hypoplastic maxilla toward a more anterior direction and advanced the face even above the level of Le Fort lll with only a minor effect on dentoalveolar units. The correction of occlusion and facial convexity were stable in the long term. CONCLUSIONS: The using BAMP may improve the position of the maxilla relative to the anterior cranial base for the correction of mild maxillary hypoplasia in adolescent patients with CLP/CP. The achieved results are rather stable in the long term.

Beyond the surface: exploring contributing factors to bone anchored hearing implant complications.

INTRODUCTION: Bone anchored hearing implants (BAHI) are considered for conductive and mixed hearing loss, relying on osseointegration of a titanium implant. Limitations relate to constant skin contact, with resultant percutaneous infections and granulation. This study investigates whether patient characteristics and implant-specifications contribute to BAHIs' skin complications in a cohort with a uniform surgical approach. METHODS: A 10 year (2014-2024) retrospective cohort study was conducted on BAHI procedures that were undertaken using a tissue-preserving 'punch' technique. Data on patient demographics, co-morbidities, implant type, surgical approach, and complications were collected. Poisson regression analysis was used to identify predictors of complications. RESULTS: A total of 53 patients undergoing 55 BAHI surgeries by three ENT consultants were included. Factors that greatly increased implant-related percutaneous infections included the Cochlear™ BIA400 implant when compared to the Ponto™ BHX implant (twofold, CI 2.03-2.16), abutment sizes ≤ 10 mm (fourfold, CI 3.99-4.12) and male gender (9%, CI 1.07-1.12). Granulation episodes were affected by cardiovascular disease (CVD) status (1.5-fold, CI 0.26-0.78), BIA400 implant (threefold, CI 8.8.-9.2) and abutment sizes ≤ 10 mm (fourfold, CI 3.6-3.73). Revision surgery episodes increased with diabetic status (1.2-fold, CI 0.06-0.37) and abutment sizes ≤ 10 mm (threefold, 3.303-3.304). CONCLUSIONS: Larger cohort studies are required to confirm findings, particularly for implant and abutment size contributions. However, the findings suggest that using a larger abutment size when skin thickness meassuremets are borderline, improved hygiene education in male patients, pre-operative optimisation of CVD and diabetes, and adjusted patient follow-up based on risk stratification of the contributing factors to complication rates could reduce complication rates.

Evaluation of the Transfemoral Bone-Implant Interface Properties Using Vibration Analysis.

Evaluating the bone-implant interface (BII) properties of osseointegrated transfemoral (TFA) implants is important for early failure detection and prescribing loads during rehabilitation. The objective of this work is to derive and validate a 1D finite element (FE) model of the Osseointegrated Prosthetic Limb (OPL) TFA system that can: (1) model its dynamic behaviour and (2) extract the BII properties. The model was validated by: (1) comparing the 1D FE formulation to the analytical and 3D FE solutions for a simplified cylinder, (2) comparing the vibration modes of the actual TFA geometry using 1D and 3D FE models, and (3) evaluating the BII properties for three extreme conditions (LOW, INTERMEDIATE, and HIGH) generated using 3D FE and experimental (where the implant was embedded, using different adhesives, in synthetic femurs) signals for additional validation. The modes predicted by the 1D FE model converged to the analytical and the 3D FE solutions for the cylinder. The 1D model also matched the 3D FE solution with a maximum frequency difference of 2.02% for the TFA geometry. Finally, the 1D model extracted the BII stiffness and the system's damping properties for the three conditions generated using the 3D FE simulations and the experimental INTERMEDIATE and HIGH signals. The agreement between the 1D FE and the 3D FE solutions for the TFA geometry indicates that the 1D model captures the system's dynamic behaviour. Distinguishing between the different BII conditions demonstrates the 1D model's potential use for the non-invasive clinical evaluation of the TFA BII properties.

Oral Health Assessment in Cleft Lip & Palate Patients During Orthodontic Treatment for Maxillary Protraction: A Periodontal & Microbiological Study.

OBJECTIVE: To assess the oral health status and microbiota of subgingival plaque in patients with surgically repaired cleft lip and palate (CLP) during orthodontic treatment for maxillary protraction with two different orthodontic appliances. DESIGN: Randomized controlled trial. SETTING: Institutional. PARTICIPANTS: A total of 90 patients with surgically repaired Unilateral Cleft Lip and Palate, out of initially enrolled 120 patients, were divided into 3 groups: experimental group I, experimental group II and control group, with 30 subjects each. Patients with a history of oral prophylaxis in last 6 months or antibiotic therapy within 3 months were excluded from the study. INTERVENTIONS: Bone Anchored Maxillary Protraction was done in experimental group I, while facemask with acrylic occlusal splint was used for maxillary protraction in experimental group II and no orthodontic intervention in control group. MEAN OUTCOME MEASURES: Plaque Index (PI), Gingival Index (GI), Gingival Bleeding Index (GBI), Probing Depth (PD), and microbiota of subgingival plaque (P. gingivalis, P. intermedia, Veillonella and Capnocytophaga) were compared at baseline (T0) and after 8 months (T1). RESULTS: The PI, GI, GBI and PD were observed to be significantly higher in experimental group II followed by experimental group I as compared to control group at 8 months interval (P < .001). The microbiota counts increased significantly in experimental group II and experimental group I (P < .001), as compared to control group. CONCLUSION: Maxillary protraction with facemask and bone plates was found to be a better alternative than facemask with occlusal splint, considering the overall oral health of patients with CLP.

The effectiveness of bone anchored maxillary protraction (BAMP) in the management of class III skeletal malocclusion in children aged 11-14 years compared with an untreated control group: A multicentre two-arm parallel randomised controlled trial.

OBJECTIVE: To evaluate the effectiveness of bone anchored maxillary protraction (BAMP) in the management of class III skeletal malocclusion in children aged 11-14 years compared with an untreated control group in terms of perceived need for orthognathic surgery, skeletal and dental change, and psychological impact. DESIGN: A multicentre two-armed parallel randomised controlled trial. SETTING: Six UK hospital orthodontic units. METHODS: A total of 57 patients were randomly allocated into either the BAMP group (BAMPG) (n = 28) or a no treatment control group (CG) (n = 29). OUTCOMES: Data collection occurred at registration (DC1),18 months (DC2) and 3 years (DC3), where skeletal and dental changes were measured from lateral cephalograms and study models. Oral Aesthetic Subjective Impact Score (OASIS) and Oral Quality of Life (OHQOL) questionnaires were used to assess the psychological impact of treatment. RESULTS: The mean age was 12.9 ± 0.7 years and 12.6 ± 0.9 years in the BAMPG and CG, respectively. At DC2, the BAMPG achieved a class III ANB improvement of +0.6° compared with -0.7° in the CG (P = 0.004). The overjet improvement was +1.4 mm for the BAMPG and -0.2 mm for the CG (P = 0.002). There was no evidence of any other group differences for the other skeletal or dental cephalometric outcomes (P > 0.05) or the questionnaire data (OASIS P = 0.10, OHQOL P = 0.75). At DC2, the 18-month follow-up, 22% of the BAMPG achieved a positive overjet. At the 3-year follow-up (DC3), fewer participants in the BAMPG were perceived to need orthognathic surgery (48%) compared with 75% of participants in the CG (P = 0.04), with an odds ratio of 0.31 (95% confidence interval = 0.10-0.95). CONCLUSION: The BAMP technique did not show any social or psychological benefits; however, the skeletal class III improvement in ANB and the overjet change were sufficient to reduce the perceived need for orthognathic surgery by 27% compared with the CG.

Evaluation of a super powerful bone-anchored hearing system and its users: A retrospective study.

INTRODUCTION: Although the Baha 5SP has been commercially available for six years, very few studies have been performed on the device's efficacy. The current study aims to evaluate the characteristics and audiological results in patients with severe-to-profound mixed hearing loss fitted with this superpower sound processor. METHODS: This retrospective evaluation was conducted at a tertiary referral centre where a series of 82 adult patients with severe-to-profound mixed hearing loss were implanted with a percutaneous bone-anchored hearing system and fitted with a superpower sound processor between 2016 and 2019. Patients with incomplete or unreliable audiological data (n = 24) were excluded, resulting in 58 data sets for analysis. The main outcome measures were unaided and aided pure-tone thresholds and aided free-field speech perception in quiet. RESULTS: The median unaided air conduction (AC) threshold averaged across 0.5, 1 and 2 kHz (PTA0.5-2kHz) of all patients was 75 dB hearing loss (HL); the median unaided AC averaged across 1, 2 and 4 kHz (PTA1-4kHz) was 84 dB HL. For bone conduction and direct bone conduction, the median PTA0.5-2kHz was 52 and 47 dB HL, respectively. With the superpower device, the median free-field speech reception threshold was 54 dB sound pressure level (SPL), and the median speech perception score at 65 dB SPL was 80%. CONCLUSIONS: At least 75% of the patients reached a maximum phoneme score of 70%. For patients with lower scores, the superpower device still provides a substantial hearing benefit. This makes the superpower device particularly suitable for patients with severe-to-profound mixed hearing loss with a contraindication for conventional hearing aids and/or cochlear implants.

Cumulative loading increases and loading asymmetries persist during walking for people with a transfemoral bone-anchored limb.

BACKGROUND: A bone-anchored limb (BAL) is an alternative to a traditional socket-type prosthesis for people with transfemoral amputation. Early laboratory-based evidence suggests improvement in joint and limb loading mechanics during walking with a BAL compared to socket prosthesis use. However, changes in cumulative joint and limb loading measures, which may be predictive of degenerative joint disease progression, remain unknown. RESEARCH QUESTION: Do cumulative total limb and hip joint loading during walking change using a BAL for people with unilateral transfemoral amputation, compared to prior socket prosthesis use? METHODS: A case-series cohort of eight participants with prior unilateral transfemoral amputation who underwent BAL hardware implantation surgery were retrospectively analyzed (4 M/4 F; BMI: 27.7 ± 3.1 kg/m2; age: 50.4 ± 10.2 years). Daily step count and whole-body motion capture data were collected before (using socket prosthesis) and one-year after BAL hardware implantation. Cumulative total limb and hip joint loading and between-limb loading symmetry metrics were calculated during overground walking at both time points and compared using Cohen's d effect sizes. RESULTS: One year after BAL hardware implantation, participants demonstrated bilateral increases in cumulative total limb loading (amputated: d = -0.65; intact: d = -0.72) and frontal-plane hip moment (amputated: d = -1.29; intact: d = -1.68). Total limb loading and hip joint loading in all planes remained asymmetric over time, with relative overloading of the intact limb in all variables of interest at the one-year point. SIGNIFICANCE: Despite increases in cumulative total limb and hip joint loading, between-limb loading asymmetries persist. Habitual loading asymmetry has been implicated in contributing to negative long-term joint health and onset or progression of degenerative joint diseases. Improved understanding of methods to address habitual loading asymmetries is needed to optimize rehabilitation and long-term joint health as people with transfemoral amputation increase physical activity when using a BAL.

Biomechanics of conventional and miniscrew-assisted rapid palatal expansion.

Posterior Crossbite is a common condition resulting because of transverse maxillary deficiency. The growth of the craniofacial complex finishes first in the transverse dimension, followed by sagittal and vertical dimensions. Conventional rapid palatal expansion (RPE) appliances are commonly used to correct transverse maxillary deficiency. Although RPE is efficient in correcting posterior crossbite, it results in dental side effects such as buccal tipping of maxillary molars, root resorption, bone dehiscence, and relapse. Mini-implant-assisted RPE has been introduced to increase the skeletal effects of expansion especially in patients with increased maturation and greater interdigitation of midpalatal suture. This article will review the biomechanics of RPE and mini-implant-assisted RPE. Additionally, the different designs of MARPE and the long-term clinical effects of expansion appliances will also be discussed in detail.

The significance of frontal plane static alignment in anticipating dynamic knee moment among transtibial prosthesis users: A cross-sectional study.

BACKGROUND: In the process of transtibial prosthetic fitting, alignment is the process of positioning the prosthetic foot relative to the residual limb. Changes in frontal plane alignment can impact knee moments during walking, which can either cause or, when aligned properly, prevent injuries. However, clinical evaluation of dynamic knee moments is challenging, limiting prosthetists' insights into dynamic joint loading. Typically, knee joint loading is assessed in static stance using the knee moment arm as a proxy for subsequent dynamic alignment. It remains uncertain if static alignment accurately represents actual dynamics during walking. RESEARCH QUESTION: Is the frontal knee moment arm in stance predictive for the knee moment arm and external knee adduction moment during gait in transtibial bone-anchored prosthesis users? METHODS: In this cross-sectional study, twenty-seven unilateral transtibial bone-anchored prosthesis users underwent data acquisition on the M-Gait instrumented treadmill. Static and dynamic measurements were conducted, and knee moment arm and external knee adduction moment were calculated. Pearson's correlation and linear regression analyses were performed to examine relationships between static and dynamic knee moment arms and external knee adduction moments. RESULTS: The static knee moment arm showed significant associations with dynamic knee moment arm at the ground reaction force peaks (First: r=0.60, r2=35%, p<0.001; Second: r=0.62, r2=38%, p=0.001) and knee adduction moment (First: r=0.42, r2=17%, p=0.030; Second: r=0.59, r2=35%, p=0.001). A 1 mm between-subject difference in static knee moment arm corresponded, on average, with a 0.9% difference in knee adduction moment at the first peak and a 1.5% difference at the second peak of the ground reaction force. SIGNIFICANCE: While static alignment is important to optimize adduction moments during stance it may only partly mitigate excessive moments during gait. The fair correlation and limited percentage of explained variance underscores the importance of dynamic alignment in optimizing the body's dynamic load during walking.

Clinical Outcomes of an Active, Transcutaneous, Bone Conduction Hearing Device: A Retrospective Study.

OBJECTIVE: The purpose of this study was to review patient demographics, indications, intraoperative findings, complications/adverse events, and audiological outcomes related to the implantation of the Osia 2 device. STUDY DESIGN: Retrospective case series. SETTING: Single tertiary institutional experience. METHODS: Patients who had undergone Osia 2 implantation by the senior author were identified from 2019 to present. Information was extracted from patient charts concerning patient demographics, indications for implantation, surgical findings, audiological outcomes, and adverse events. RESULTS: Sixty patients and 67 implants were included. The median age was 51 years (R: 11-92). Fifty-five percent of patients had mixed hearing loss (HL), 30% had single-sided deafness, and 15% had conductive HL. The mean operative time was 53.9 minutes. Only 4.5% of patients required bone polishing, and 3.0% required tissue thinning. The mean pure-tone averages 4 gain from unaided conditions was 41.2 dB. Mean gain at 6 and 8 kHz from unaided conditions was 35.42 and 40.67 dB, respectively. Mean improvement in speech recognition threshold and word recognition score was significant in noise and quiet conditions. The all-cause adverse event/complication rate in our series was 10.4%. The most common complications were infections (4.5%) and poorly controlled postoperative pain (3.0%). Hematomas occurred in 1.5% of patients. Reoperation was required in 4 patients; explant in 1. CONCLUSION: Use of the Osia 2 device in our series has resulted in good hearing outcomes, particularly in terms of high frequency gain. Complication rates were low. To our knowledge, this is the largest study to date reporting on Osia 2 outcomes.

Bone-Anchored Hearing Aid Effects on Vestibular Function: A Preliminary Report.

OBJECTIVE: Cochlear receptors are sensitive to vibratory stimuli. Based on this sensibility, bone-anchored hearing aids have been introduced to correct unilateral or bilateral conductive or mixed hearing loss and unilateral deafness. The vestibular system is also sensitive to the vibratory stimulus and this type of response is used in clinics to test its functionality. Being aware of this double separated sensibility, we wondered whether bone vibration, which activates the acoustic receptors of patients with bone conduction aids, can also influence the functionality of the vestibular system. METHODS: To this end, we recruited 12 patients with a bone-anchored hearing aid and evaluated their vestibular function with and without an activated vibratory acoustic device. RESULTS: Our results show that the vibratory stimulus delivered by the bone conduction aid also reaches and stimulates the vestibular receptors; this stimulation is evidenced by the appearance or modification of some nystagmus findings during bedside vestibular testing. Despite this, none of these patients complained of dizziness or vertigo during prosthesis use. Nystagmus that appeared or changed during acoustic vibratory stimulation through the prosthesis was almost all predominantly horizontal, unidirectional with respect to gaze or body position, inhibited by fixation, and most often consistent with vestibular function tests indicating peripheral vestibular damage. CONCLUSIONS: The findings of sound-evoked nystagmus seem to indicate peripheral rather than central vestibular activation. The occurrence of some predominantly horizontal and high-frequency induced nystagmus seems to attribute the response mainly to the utricle and lateral semicircular canal.

Bone-anchored prostheses for transfemoral amputation: a systematic review of outcomes, complications, patient experiences, and cost-effectiveness.

Introduction: Bone-anchored prostheses (BAP) are an advanced reconstructive surgical approach for individuals who had transfemoral amputation and are unable to use the conventional socket-suspension systems for their prostheses. Access to this technology has been limited in part due to the lag between the start of a new procedure and the availability of evidence that is required before making decisions about widespread provision. This systematic review presents as a single resource up-to-date information on aspects most relevant to decision makers, i.e., clinical efficacy, safety parameters, patient experiences, and health economic outcomes of this technology. Methods: A systematic search of the literature was conducted by an information specialist in PubMed, MEDLINE, Embase, CINAHL, Cochrane Library, the Core Collection of Web of Science, CADTH's Grey Matters, and Google Scholar up until May 31, 2023. Peer-reviewed original research articles on the outcomes of clinical effectiveness (health-related quality of life, mobility, and prosthesis usage), complications and adverse events, patient experiences, and health economic outcomes were included. The quality of the studies was assessed using the Oxford Centre for Evidence-Based Medicine Levels of Evidence and ROBINS-I, as appropriate. Results: Fifty studies met the inclusion criteria, of which 12 were excluded. Thirty-eight studies were finally included in this review, of which 21 reported on clinical outcomes and complications, 9 case series and 1 cohort study focused specifically on complications and adverse events, and 2 and 5 qualitative studies reported on patient experience and health economic assessments, respectively. The most common study design is a single-arm trial (pre-/post-intervention design) with varying lengths of follow-up. Discussion: The clinical efficacy of this technology is evident in selected populations. Overall, patients reported increased health-related quality of life, mobility, and prosthesis usage post-intervention. The most common complication is a superficial or soft-tissue infection, and more serious complications are rare. Patient-reported experiences have generally been positive. Evidence indicates that bone-anchored implants for prosthesis fixation are cost-effective for those individuals who face significant challenges in using socket-suspension systems, although they may offer no additional advantage to those who are functioning well with their socket-suspended prostheses.

The biomechanical influence of transtibial Bone-Anchored limbs during walking.

Individuals with unilateral transtibial amputation (TTA) using socket prostheses demonstrate asymmetric joint biomechanics during walking, which increases the risk of secondary comorbidities (e.g., low back pain (LBP), osteoarthritis (OA)). Bone-anchored limbs are an alternative to socket prostheses, yet it remains unknown how they influence multi-joint loading. Our objective was to determine the influence of bone-anchored limb use on multi-joint biomechanics during walking. Motion capture data (kinematics, ground reaction forces) were collected during overground walking from ten participants with unilateral TTA prior to (using socket prostheses) and 12-months after bone-anchored limb implantation. Within this year, each participant completed a rehabilitation protocol that guided progression of loading based on patient pain response and optimized biomechanics. Musculoskeletal models were developed at each testing timepoint (baseline or 12-months after implantation) and used to calculate joint kinematics, internal joint moments, and joint reaction forces (JRFs). Analyses were performed during three stance periods on each limb. The between-limb normalized symmetry index (NSI) was calculated for joint moments and JRF impulses. Discrete (range of motion (ROM), impulse NSI) dependent variables were compared before and after implantation using paired t-tests with Bonferroni-Holm corrections while continuous (ensemble averages of kinematics, moments, JRFs) were compared using statistical parametric mapping (p < 0.05). When using a bone-anchored limb, frontal plane pelvic (residual: pre = 9.6 ± 3.3°, post = 6.3 ± 2.5°, p = 0.004; intact: pre = 10.2 ± 3.9°, post = 7.9 ± 2.6°, p = 0.006) and lumbar (residual: pre = 15.9 ± 7.0°, post = 10.6 ± 2.5°, p = 0.024, intact: pre = 17.1 ± 7.0°, post = 11.4 ± 2.8°, p = 0.014) ROM was reduced compared to socket prosthesis use. The intact limb hip extension moment impulse increased (pre = -11.0 ± 3.6 Nm*s/kg, post = -16.5 ± 4.4 Nm*s/kg, p = 0.005) and sagittal plane hip moment impulse symmetry improved (flexion: pre = 23.1 ± 16.0 %, post = -3.9 ± 19.5 %, p = 0.004, extension: pre = 29.2 ± 20.3 %, post = 8.7 ± 22.9 %, p = 0.049). Residual limb knee extension moment impulse decreased compared to baseline (pre = 15.7 ± 10.8 Nm*s/kg, post = 7.8 ± 3.9 Nm*s/kg, p = 0.030). These results indicate that bone-anchored limb implantation alters multi-joint biomechanics, which may impact LBP or OA risk factors in the TTA population longitudinally.

Paediatric percutaneous bone anchored hearing aid implant failures: Comparing the experience of a tertiary centre with a systematic review of the literature and meta-analysis.

BACKGROUND: Despite the proven audiological benefits of Percutaneous Bone Anchored Hearing Aids (BAHAs) in paediatric patients with conductive or mixed hearing loss, their adoption has been limited due to concerns over implant failure and associated complications. This paper conducts a systematic review and meta-analysis to assess the prevalence of implant failure in paediatric populations, combined with a case series from our tertiary referral centre. METHODS: A comprehensive literature search identified 562 articles, from which 34 were included in the review, covering 1599 implants in 1285 patients. Our retrospective case series included consecutive patients from our tertiary referral centre who underwent percutaneous BAHA implantation from 2003-2019. RESULTS: Meta-analysis revealed an overall implant failure rate of 11%, predominantly attributed to traumatic extrusion. Our retrospective case series comprised 104 implantations in 76 patients, with a 4.8% failure rate. DISCUSSION: Factors contributing to the lower-than-expected failure rates in the case series likely included consistent use of 4 mm fixtures from a single manufacturer and older age at implantation. The study underscores the need for standardised reporting formats in bone conduction implants research, given the systematic review's limitations in study design heterogeneity, especially with the expected rise in the adoption of novel active devices.

Lumbopelvic movement coordination during walking improves with transfemoral bone anchored limbs: Implications for low back pain.

BACKGROUND: Low back pain (LBP) is more prevalent in patients with transfemoral amputation using socket prostheses than able-bodied individuals, in part due to altered spinal loading caused by aberrant lumbopelvic movement patterns. Early evidence surrounding bone-anchored limb functional outcomes is promising, yet it remains unknown if this novel prosthesis influences LBP or movement patterns known to increase its risk. RESEARCH QUESTION: How are self-reported measures of LBP and lumbopelvic movement coordination patterns altered when using a unilateral transfemoral bone-anchored limb compared to a socket prosthesis? METHODS: Fourteen patients with unilateral transfemoral amputation scheduled to undergo intramedullary hardware implantation for bone-anchored limbs due to failed socket use were enrolled in this longitudinal observational cohort study (7 F/7 M, Age: 50.2±12.0 years). The modified Oswestry Disability Index (mODI) (self-reported questionnaire) and whole-body motion capture during overground walking were collected before (with socket prosthesis) and 12-months following bone-anchored limb implantation. Lumbopelvic total range of motion (ROM) and continuous relative phase (CRP) segment angles were calculated during 10 bilateral gait cycles. mODI, total ROM, CRP and CRP variabilities were compared between time points. RESULTS: mODI scores were significantly reduced 12-months after intramedullary hardware implantation for the bone-anchored limb (P = 0.013). Sagittal plane trunk and pelvis total ROM during gait were reduced after implantation (P = 0.001 and P < 0.001, respectively). CRP values were increased (more anti-phase) in the sagittal plane during single limb stance and reduced (more in-phase) in the transverse plane during pre-swing of the amputated limb gait cycle (P << 0.001 and P = 0.029, respectively). No differences in CRP values were found in the frontal plane. SIGNIFICANCE: Decreases in mODI scores and lumbopelvic ROM, paired with the changes in lumbopelvic coordination, indicate that bone-anchored limbs may reduce LBP symptoms and reduce compensatory movement patterns for people with unilateral transfemoral amputation.

Soft and Hard Tissue Integration around Percutaneous Bone-Anchored Titanium Prostheses: Toward Achieving Holistic Biointegration.

A holistic biointegration of percutaneous bone-anchored metallic prostheses with both hard and soft tissues dictates their longevity in the human body. While titanium (Ti) has nearly solved osseointegration, soft tissue integration of percutaneous metallic prostheses is a perennial problem. Unlike the firm soft tissue sealing in biological percutaneous structures (fingernails and teeth), foreign body response of the skin to titanium (Ti) leads to inflammation, epidermal downgrowth and inferior peri-implant soft tissue sealing. This review discusses various implant surface treatments/texturing and coatings for osseointegration, soft tissue integration, and against bacterial attachment. While surface microroughness by SLA (sandblasting with large grit and acid etched) and porous calcium phosphate (CaP) coatings improve Ti osseointegration, smooth and textured titania nanopores, nanotubes, microgrooves, and biomolecular coatings encourage soft tissue attachment. However, the inferior peri-implant soft tissue sealing compared to natural teeth can lead to peri-implantitis. Toward this end, the application of smart multifunctional bioadhesives with strong adhesion to soft tissues, mechanical resilience, durability, antibacterial, and immunomodulatory properties for soft tissue attachment to metallic prostheses is proposed.

Mechanical load applied by Intraosseous Transcutaneous Amputation Prosthesis (ITAP) during walking on level and sloped treadmill: A case study.

This proof of concept study presents a method to collect and analyse kinetic data from one participant with a transfemoral amputation fitted with a percutaneous osseointegrated implant walking on a level and sloped treadmill. We describe the construction of and results from a bespoke wireless six axis load cell built into one participant's prosthetic assembly. The load cell does not clinically compromise the participant in any way and is an initial milestone in the development of a light-weight wireless load cell for use with percutaneous osseointegrated implants. In this case, it is the first time that kinetic data from a participant fitted with an Intraosseous Transcutaneous Amputation Prosthesis has been published. We propose that the data can be used to model the load transfer to the host bone, with several clinically significant applications. The raw dynamic data are made available and quasi-static load cases for each functional phase of gait are presented. Peak forces obtained in the medio-lateral (X), cranio-caudal (Y) and antero-posterior (Z) axes over level ground respectively were -243.8 N (0.24 BW), 1321.5 N (1.31 BW) and -421.8 N (0.42 BW); uphill were -141.0 N (0.14 BW), 1604.2 N (1.59 BW), -498.1 N (0.49 BW); downhill were -206.0 N (0.20 BW), 1103.9 N (1.09 BW), -547.2 N (0.54 BW). The kinetics broadly followed able bodied gait patterns with some gait strategies consistent in participants with other implant designs or prosthetic socket connections, for example offloading the artificial limb downhill.