Staged implantation of active transcutaneous bone conduction hearing devices (BCHD) after explantation of older generation bone anchored hearing aids (BAHAs): Surgical outcomes and approach to management.

PURPOSE: To evaluate outcomes following explantation of percutaneous or transcutaneous bone conduction implants (pBCIs or tBCIs) and subsequent implantation of transcutaneous active bone conduction hearing devices (BCHDs); to provide guidance regarding staging of surgery and adjunctive procedures. MATERIALS AND METHODS: Retrospective chart review of eight adult subjects (ten ears) with pBCIs or tBCIs who underwent explantation of their device and subsequent implantation with a BCHD [MED-EL BONEBRIDGE™ (n = 7, 70 %) or Cochlear™ Osia® (n = 3, 30 %)]. RESULTS: Reasons for pBCI or tBCI explantation were pain (60 %, 6/10), infection (60 %, 6/10), skin overgrowth (50 %, 5/10), and inability to obtain new processors (20 %, 2/10). Median time between pBCI or tBCI removal and BCHD staged implant was 4.7 (IQR 2.2-8.1) months. Two subjects developed complications following BCHD implantation. One had a persistent wound overlying the osseointegrated screw after removal of the pBCI abutment, requiring removal and temporalis rotational flap. Staged Osia® implantation was performed, but ultimately wound dehiscence developed over the device. The second subject experienced an infection after BONEBRIDGE™ implantation (32 days after pBCI explant), necessitating washout and treatment with intravenous antibiotics. There was subsequent device failure. CONCLUSION: The transition from a pBCI or tBCI to a novel transcutaneous device is nuanced. Staged pBCI or tBCI explantation and novel BCHD implantation with sufficient time for wound healing is vital. Adjunctive procedures to augment soft tissue in cases of prior attenuation may be required to avoid complications with larger internal devices.

The influence of prosthetic suspension on gait and cortical modulations is persons with a transfemoral amputation: socket-suspended versus bone-anchored prosthesis.

BACKGROUND: Persons with a transfemoral amputation (TFA) often experience difficulties in daily-life ambulation, including an asymmetrical and less stable gait pattern and a greater cognitive demand of walking. However, it remains unclear whether this is effected by the prosthetic suspension, as eliminating the non-rigid prosthetic connection may influence stability and cortical activity during walking. Spatiotemporal and stability-related gait parameters, as well as cortical activity during walking, were evaluated between highly active individuals (MFC-level K3-4) with a TFA and able-bodied (AB) persons, and between persons with a bone-anchored prosthesis (BAP) and those with a socket-suspended prosthesis (SSP). METHODS: 18 AB persons and 20 persons with a unilateral TFA (10 BAP-users, 10 SSP-users) walked on a treadmill at their preferred speed. Spatiotemporal and margin of stability parameters were extracted from three-dimensional movement recordings. In addition, 126-channel electroencephalogram (EEG) was recorded. Brain-related activity from several cortical areas was isolated using independent component analysis. Source-level data were divided into gait cycles and subjected to time-frequency analysis to determine gait-cycle dependent modulations of cortical activity. RESULTS: Persons with TFA walked with smaller and wider steps and with greater variability in mediolateral foot placement than AB subjects; no significant differences were found between BAP- and SSP-users. The EEG analysis yielded four cortical clusters in frontal, central (both hemispheres), and parietal areas. No statistically significant between-group differences were found in the mean power over the entire gait cycle. The event-related spectral perturbation maps revealed differences in power modulations (theta, alpha, and beta bands) between TFA and AB groups, and between BAP- and SSP-users, with largest differences observed around heel strike of either leg. CONCLUSIONS: The anticipated differences in gait parameters in persons with TFA were confirmed, however no significant effect of the fixed suspension of a BAP was found. The preliminary EEG findings may indicate more active monitoring and control of stability in persons with TFA, which appeared to be timed differently in SSP than in BAP-users. Future studies may focus on walking tasks that challenge stability to further investigate differences related to prosthetic suspension.

Validation of IMU against optical reference and development of open-source pipeline: proof of concept case report in a participant with transfemoral amputation fitted with a Percutaneous Osseointegrated Implant.

BACKGROUND: Systems that capture motion under laboratory conditions limit validity in real-world environments. Mobile motion capture solutions such as Inertial Measurement Units (IMUs) can progress our understanding of "real" human movement. IMU data must be validated in each application to interpret with clinical applicability; this is particularly true for diverse populations. Our IMU analysis method builds on the OpenSim IMU Inverse Kinematics toolkit integrating the Versatile Quaternion-based Filter and incorporates realistic constraints to the underlying biomechanical model. We validate our processing method against the reference standard optical motion capture in a case report with participants with transfemoral amputation fitted with a Percutaneous Osseointegrated Implant (POI) and without amputation walking over level ground. We hypothesis that by using this novel pipeline, we can validate IMU motion capture data, to a clinically acceptable degree. RESULTS: Average RMSE (across all joints) between the two systems from the participant with a unilateral transfemoral amputation (TFA) on the amputated and the intact sides were 2.35° (IQR = 1.45°) and 3.59° (IQR = 2.00°) respectively. Equivalent results in the non-amputated participant were 2.26° (IQR = 1.08°). Joint level average RMSE between the two systems from the TFA ranged from 1.66° to 3.82° and from 1.21° to 5.46° in the non-amputated participant. In plane average RMSE between the two systems from the TFA ranged from 2.17° (coronal) to 3.91° (sagittal) and from 1.96° (transverse) to 2.32° (sagittal) in the non-amputated participant. Coefficients of Multiple Correlation (CMC) results between the two systems in the TFA ranged from 0.74 to > 0.99 and from 0.72 to > 0.99 in the non-amputated participant and resulted in 'excellent' similarity in each data set average, in every plane and at all joint levels. Normalized RMSE between the two systems from the TFA ranged from 3.40% (knee level) to 54.54% (pelvis level) and from 2.18% to 36.01% in the non-amputated participant. CONCLUSIONS: We offer a modular processing pipeline that enables the addition of extra layers, facilitates changes to the underlying biomechanical model, and can accept raw IMU data from any vendor. We successfully validate the pipeline using data, for the first time, from a TFA participant using a POI and have proved our hypothesis.

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.

Management of Bone Bridge Exposure Using Superficial Temporal Island Flap After Auricle Reconstruction and Bone Bridge Implantation.

BACKGROUND: Congenital microtia usually lead to impairment of both appearance and hearing especially for patients with bilateral microtia. The simultaneous combination of auricular reconstruction and bone bridge implantation has been proved effective and satisfied with the patients. We retrospectively analyzed this method and the complication of it. We summarized and found the application of superficial temporal island flap for repairing the bone bridge exposure. METHODS: From January 2017 to December 2020, there were 84 patients who underwent the surgery of auricular reconstruction simultaneously combined with bone bridge implantation in the Plastic Surgery Hospital of Chinese Academy of Medical Sciences. And after 12 months follow-up, we evaluated the postoperative effect and collected data on the patients who had bone bridge exposure. We analyzed the reason of the complication and covered the exposed bone bridge with superficial temporal island flap. RESULTS: There were 3 cases (3.6%) of implant exposure and the surgical outcome was satisfactory using the repairment of superficial temporal island flap. All 3 patients were healed in 1-stage surgery, and no further implant exposure occurred after another 12-month follow-up. CONCLUSIONS: The method of auricular reconstruction simultaneously combined with bone bridge implant is an optional choice for patients with bilateral microtia, and has a low incidence of implant exposure. The superficial temporal island flap could well fill the dead space and increase the wear resistance of the tissue, and the scar was not obvious. We found and summarized a satisfactory method of repairing the implantation exposure using the superficial temporal island flap. LEVEL OF EVIDENCE: Level IV, cases study.

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.

Bone-anchored prostheses for lower limb amputation in a French cohort with 1-15 years of follow-up: implant survival rates, mechanical complications, and reported outcomes.

PURPOSE: To evaluate the implant survival rate, mechanical complications, and reported patient outcomes of bone-anchored prostheses for patients with lower limb amputation in France after 1-15 years of follow-up. METHODS: This retrospective cohort study included patients who underwent surgery at a single center in France between 2007 and 2021. The primary outcomes were the implant survival rate and functional scores assessed by the Questionnaire for Transfemoral Amputees (Q-TFA). Secondary outcomes were adverse events that occurred during follow-up. RESULTS: The cohort consisted of 20 bone-anchored prostheses in 17 patients. The main level of amputation was transfemoral (82%, n = 14). The main reason for amputation was trauma (n = 15). The mean age at amputation was 32 (range 15-54) years, and the mean age at the first stage of osseointegration was 41 (range 21-58) years. The Kaplan-Meier survival curve showed respective survival rates of 90%, 70%, and 60% at 2, 10, and 15 years. All Q-TFA scores were significantly improved at last the follow-up. Eleven patients (65%) experienced mechanical complications. In total, 37 infectious events occurred in 13 patients (76%), mainly comprising stage 1 infections (68%, n = 25). Only two cases of septic loosening occurred (12%), leading to implant removal. CONCLUSION: This is the first French cohort of bone-anchored prostheses and among the series with the longest follow-up periods. The findings indicate that bone-anchored prostheses are safe and reliable for amputee patients who have difficulties with classic prostheses.

Survival of osseointegrated implants in head and neck cancer patients submitted to multimodal treatment: a systematic review and meta-analysis.

PURPOSE: To investigate the survival rate in implants placement in irradiated and non-irradiated bone in patients undergoing head and neck cancer (HNC) treatment. We focused on the consequences of the main complications, such as osteoradionecrosis and peri-implantitis. METHODS: An electronic search conducted by PRISMA protocol was performed. Full texts were carefully assessed, and data were assimilated into a tabular form for discussion and consensus among the expert panel. The quality assessment and the risk of bias are verified by Joanna Briggs Institute checklist (JBI) and The Newcastle-Ottawa Scale (NOS), and Risk of Bias in Non-Randomized Studies of Interventions (ROBINS-I) assessment tool. RESULTS: A total of 452 records were identified in the based on our PICOs strategy and after screening, 19 articles were included in the descriptive analysis of the review. Totaling 473 implants placed in irradiated and non-irradiated bone, and 31.6% of the patients were over 60 years of age. 57.9%) performed implant placement in a period of 12 months or more after the ending of radiotherapy. Only 5 studies had a follow-up period longer than 5 years after implant placement, of which three were used for the meta-analysis. In the meta-analysis of 5-year survival rate, analysis of implants in irradiated bone was assessed; a random effect model was used and a weighted proportion (PP) of 93.13% (95% CI: 87.20-99.06; p < 0.001), and in the 5-year survival rate, analysis of implants in non-irradiated bone was analysed; a fixed effect model was used and a weighted proportion (PP) of 98.52% survival (95% CI: 97.56-99.48, p < 0.001). CONCLUSIONS: Survival rates of implants placed in irradiated bone are clinically satisfactory after a follow-up of 5 years, with a fewer percentage than in implants placed in non-irradiated bone after metanalyses performed.

Walking ability of individuals fitted with transfemoral bone-anchored prostheses: A comparative study of gait parameters.

OBJECTIVE: This study presents the walking abilities of participants fitted with transfemoral bone-anchored prostheses using a total of 14 gait parameters. DESIGN: Two-centre retrospective cross-sectional comparative study. SETTING: Research facilities equipped with tridimensional motion capture systems. PARTICIPANTS: Two control arms included eight able-bodied participants arm (54 ± 9 years, 1.75 ± 0.07 m, 76 ± 7 kg) and nine participants fitted with transfemoral socket-suspended prostheses arm (59 ± 9 years, 1.73 ± 0.07 m, 80 ± 16 kg). The intervention arm included nine participants fitted with transfemoral bone-anchored prostheses arm (51 ± 13 years, 1.78 ± 0.09 m, 87.3 ± 16.1 kg). INTERVENTION: Fitting of transfemoral bone-anchored prostheses. MAIN MEASURES: Comparisons were performed for two spatio-temporal, three spatial and nine temporal gait parameters. RESULTS: The cadence and speed of walking were 107 ± 6 steps/min and 1.23 ± 0.19 m/s for the able-bodied participants arm, 88 ± 7 steps/min and 0.87 ± 0.17 m/s for the socket-suspended prosthesis arm, and 96 ± 6 steps/min and 1.03 ± 0.17 m/s for bone-anchored prosthesis arm, respectively. Able-bodied participants and bone-anchored prosthesis arms were comparable in age, height, and body mass index as well as cadence and speed of walking, but the able-bodied participant arm showed a swing phase 31% shorter. Bone-anchored and socket-suspended prostheses arms were comparable for age, height, mass, and body mass index as well as cadence and speed of walking, but the bone-anchored prosthesis arm showed a step width and duration of double support in seconds 65% and 41% shorter, respectively. CONCLUSIONS: Bone-anchored and socket-suspended prostheses restored equally well the gait parameters at a self-selected speed. This benchmark data provides new insights into the walking ability of individuals using transfemoral bionics bone-anchored prostheses.

Have Surgery and Implant Modifications Been Associated With Reduction in Soft Tissue Complications in Transfemoral Bone-anchored Prostheses?

BACKGROUND: The most frequently occurring adverse events in individuals with a transfemoral amputation treated with a bone-anchored prosthesis are soft tissue infections and stoma-related complications. These soft tissue complications are believed to be influenced by surgical technique and implant design, but little is known about the effect of changes to treatment on these events. QUESTIONS/PURPOSES: (1) What is the result of surgical technique and implant modifications on the incidence of soft tissue infections and stoma-related complications in transfemoral bone-anchored prosthesis users, depending on whether they had a conventional stoma and a cobalt-chrome-molybdenum (CoCrMo) osseointegration implant (treatment period 2009 to 2013) or a shallower stoma and titanium osseointegration implant (2015 to 2018)? (2) What is the incidence of serious complications, such as bone or implant infection, aseptic loosening, intramedullary stem breakage, and periprosthetic fracture? METHODS: Between 2009 and 2013, we performed osseointegration implant surgery using a conventional surgical technique and a CoCrMo implant in 42 individuals who had a lower extremity amputation experiencing socket-related problems that resulted in limited prosthesis use. We considered all individuals treated with two-stage surgery with a standard press-fit transfemoral osseointegration implant as potentially eligible for inclusion. Based on this, 100% (42) were eligible, and 5% (two of 42) were excluded because they did not provide informed consent, leaving 95% (40 of 42) for analysis. Between 2015 and 2018, we treated 79 individuals with similar indications with osseointegration implant surgery, now also treating individuals with dysvascular amputations. We used an adapted surgical technique resulting in a shallower stoma combined with a titanium implant. Using the same eligibility criteria as for the first group, 51% (40 of 79) were eligible; 49% (39 of 79) were excluded because they were treated with transtibial amputation, a patient-specific implant, or single-stage surgery and 1% (one of 79) were lost before the 2-year follow-up interval, leaving 49% (39 of 79) for analysis. The period of 2013 to 2015 was a transitional period and was excluded from analysis in this study to keep groups reasonably comparable and to compare a historical approach with the present approach. Hence, we presented a comparative study of two study groups (defined by surgical technique and implant design) with standardized 2-year follow-up. The risk factors for adverse events were similar between groups, although individuals treated with the shallow stoma surgical technique and titanium implant potentially possessed an increased risk because of the inclusion of individuals with dysvascular amputation and the discontinuation of prolonged postoperative antibiotic prophylaxis. Outcomes studied were soft tissue infections and stoma-related complications (hypergranulation or keloid formation as well as stoma redundant tissue) and bone or implant infection, aseptic loosening, implant stem breakage, periprosthetic fracture, and death. RESULTS: Patients treated with the shallow stoma surgical technique and titanium implant experienced fewer soft tissue infections (13 versus 76 events, absolute risk 0.17 [95% CI 0.09 to 0.30] versus 0.93 [95% CI 0.60 to 1.45]; p < 0.01), which were treated with less invasive measures, and fewer stoma redundant tissue events (0 versus five events, absolute risk 0 versus 0.06 [95% CI 0.03 to 0.14]) than patients treated with the conventional stoma surgical technique and CoCrMo implant. This was contrasted by an increased incidence of surgical site infections occurring between surgical stages 1 and 2, when no stoma was yet created, after the implementation of treatment changes (conventional surgery and CoCrMo implant versus shallow stoma surgery and titanium implant: one versus 11 events, absolute risk 0.01 [95% CI 0.00 to 0.08] versus 0.14 [95% CI 0.08 to 0.25]; p = 0.02). Patients treated with the shallow stoma surgical technique and titanium implant did not experience serious complications, although bone infections occurred (six events in 8% [three of 40] of patients) in the conventional surgery and CoCrMo implant group, all of which were successfully treated with implant retention. CONCLUSION: Adaptations to surgical technique and newer implant designs, as well as learning curve and experience, have resulted in a reduced incidence and severity of soft tissue infections and stoma redundant tissue, contrasted by an increase in surgical site infections before stoma creation. Serious complications such as deep implant infection were infrequent in this 2-year follow-up period. We believe the benefits of these treatment modifications outweigh the disadvantages and currently advise surgeons to create a shallower stoma with a stable soft tissue envelope, combined with a titanium implant. LEVEL OF EVIDENCE: Level III, therapeutic study.

New Osia® OSI200 active transcutaneous bone-anchored hearing device: how I do it.

INTRODUCTION: The new Osia® OSI200 implant incorporates a receiver coil and Piezo Power™ Transducer into one monolithic unit. Appropriate planning and surgical approach is needed for suitable positioning of the device. METHOD: To optimise the surgical field and provide tension-free wound closure our team have adopted a versatile 'Sheffield-S' post-auricular incision which remains hidden within the hairline. CONCLUSION: This incision provides adequate exposure for device placement and bone polishing/recessing. The soft tissue approach has resulted in improved operative efficacy particularly in those patients with irregular cortical bone or where pre-existing osseointegrated implants need to be removed or avoided.

Activities of daily living in lower limb amputees with a bone-anchored prosthesis: a retrospective case series with 24 months' follow-up.

BACKGROUND AND PURPOSE: Little is known about the activities of daily living (ADL) of patients with a bone-anchored prosthesis (BAP). We aimed to objectively measure ADL without and with BAP during standard care of follow-up. Our secondary aim was to measure mobility and walking ability. PATIENTS AND METHODS: Patients aged 18-99 years who underwent surgery for transfemoral or transtibial BAP between September 11, 2017, and February 11, 2021, were eligible for inclusion in this retrospective case series of patients with socket prosthesis. ADL was measured with a continuous recording activity monitor (hours [h]) before surgery, and at 6, 12, and 24 months with BAP. Mobility and walking ability were assessed by the Timed Up and Go test (TUG) (seconds [s]) and 6 Minute Walk Test (6MWT) (meters [m]), respectively. RESULTS: 48 of the 57 eligible patients provided informed consent and were included. Their age was 59 (1st quartile to 3rd quartile 51-63) years. Total daily activity before BAP was 1.6 h (0.82-2.1) and increased to 2.1 h (1.4-2.5) at 6, 2.0 h (1.5-2.7) at 12, and 2.7 h (2.0-3.3) at 24 months with BAP. Daily walking increased from 1.3 h (0.79-1.9) before BAP to 1.8 h (1.6-2.3) at 6, to 1.7 h (1.2-2.4) at 12, and 2.0 h (1.6-2.6) at 24 months. Median TUG decreased from 12 s (9.1-14) before BAP to 8.9 s (7.7-10) at 24 months. Mean 6MWT increased from 272 m (SD 92) before BAP to 348 m (SD 68) at 24 months. CONCLUSION: Objective measurements on ADL positively changed in patients with BAP. This effect was also seen in mobility and walking ability at 24 months.

A systematic review on removal of osseointegrated implants: un update.

BACKGROUND: Today dental implants represent an effective therapy in case of partial or total edentulism, with an excellent success rate. Despite the results obtained, there may be biological or mechanical complications during the therapy, which lead to the loss of the implant. This systematic review aims to evaluate the current state of the art in the literature on techniques used for the removal of dental implants. Various aspects will be analyzed, such as the success of the technique, any complications, and the advantages and disadvantages of their use. METHODS: Two reviewers conducted a literature analysis (PubMed, Embase, Web of Science) of the last 20 years (2003-2023). The main criterion analyzed was the success of the technique, while secondary outcomes such as complications and risks of the technique were also analyzed. 258 articles were identified in the various search databases. 42 eligible articles were subsequently identified after an article screening. Only 18 full texts were subsequently included in the review. RESULTS: A total of 18 articles were selected and 1142 implants and 595 patients were included. The main techniques used were the Counter-Torque Ratchet Technique (CTRT), Piezoelectric bone surgery (PBS), trephine drills, carbide burs, Erbium, Chromium, Yttrium, Scandium, Gallium, Garnett (Er:Cr:YSGG) laser and carbon dioxide (CO2) laser. Combined uses of techniques have been identified such as: PBS and trephine burs or carbide burs, trephine burs with the use of a 3d-printed guide, CTRT and trephine burs. The technique with the highest success rate, less morbidity for the patient, and less removal of bone appears to be the CTRT. CONCLUSIONS: The use of conservative techniques, especially CTRT, in bone removal is useful to allow for immediate implant placement in the removal area. However, further studies with a high sample size are needed to be performed on all techniques, particularly new randomized controlled trials (RCTs) that allow for the analysis of the success of alternative techniques such as Laser and Piezosurgery, which appear to be very promising.

Uprighting a mesially tilted molar using customized titanium healing abutment of an adjacent osseointegrated implant.

This case report evaluates the use of a customized healing abutment of a dental implant to upright a mesially tilted molar using elastic separating rings. The external surface of the healing abutment was roughened by air particle abrasion, and a flowable composite was applied as a collar around it. The size of the resin collar was increased several times during the molar uprighting treatment by replacing the elastic ring. The uprighting procedure was evaluated after 2 months using radiographic and clinical evaluations. After treatment, the mesiodistal space above the implant was increased from 6 mm to 9 mm as follows: 2 mm by uprighting the second molar and 1 mm by mesial shifting the second premolar, and then a screw-retained zirconia crown was placed to restore the implant. The healing abutment of the implant can be modified by adding a resin collar and used as orthodontic anchorage for uprighting the adjacent tilted molar to facilitate the prosthetic procedure. Neither special instruments nor an orthodontic background are required for this minor tooth movement.

Patient-Specific Guides for Accurate and Precise Positioning of Osseointegrated Implants in Transfemoral Amputations: A Proof-of-Concept In Vitro Study.

Background and Objectives: The treatment of transfemoral amputees using osseointegrated implants for prosthetic anchorage requires accurate implant positioning when using threaded bone-anchoring implants due to the curvature of the femur and the risk of cortical penetration in misaligned implants. This study investigated the accuracy and precision in implant positioning using additively manufactured case-specific positioning guides. Materials and Methods: The geometry and density distribution of twenty anatomic specimens of human femora were assessed in quantitative computed tomography (QCT) scanning. The imaging series were used to create digital 3D specimen models, preoperatively plan the optimal implant position and manufacture specimen-specific positioning guides. Following the surgical bone preparation and insertion of the fixture (threaded bone-anchoring element) (OPRA; Integrum AB, Mölndal, Sweden), a second QCT imaging series and 3D model design were conducted to assess the operatively achieved implant position. The 3D models were registered and the deviations of the intraoperatively achieved implant position from the preoperatively planned implant position were analyzed as follows. The achieved, compared to the planned implant position, was presented as resulting mean hip abduction or adduction (A/A) and extension or flexion (E/F) and mean implant axis offset in medial or lateral (M/L) and anterior or posterior (A/P) direction measured at the most distal implant axis point. Results: The achieved implant position deviated from the preoperative plan by 0.33 ± 0.33° (A/A) and 0.68 ± 0.66° (E/F) and 0.62 ± 0.55 mm (M/L) and 0.68 ± 0.56 mm (A/P), respectively. Conclusions: Using case-specific guides, it was feasible to achieve not only accurate but also precise positioning of the implants compared to the preoperative plan. Thus, their design and application in the clinical routine should be considered, especially in absence of viable alternatives.

A New Active Osseointegrated Implant System in Patients with Single-Sided Deafness.

OBJECTIVE: The Cochlear™ Osia® System (Osia) is an active transcutaneous bone conduction implant system intended for patients with conductive and mixed hearing loss but can also be used in cases of single-sided deafness (SSD) for the contralateral routing of signal (CROS). The Osia implant is placed subcutaneously under the intact skin behind the ear with the piezoelectric actuator connected to an osseointegrated BI300 implant - a titanium screw used for a 2-stage Baha surgery - on the mastoid. The external processor is magnetically attached to the subcutaneous implant receiver coil. As the Osia has recently been CE certified and is new on the market, with limited patient outcome data for SSD available, the objective of this study was the evaluation of surgical procedure, audiological results, and patient satisfaction for the Osia in SSD patients. STUDY DESIGN: In a prospective, monocentric clinical observation study, 6 patients (18 years of age or older) with SSD and bone conduction thresholds pure tone average 0.5, 1, 2, and 4 kHz ≤25 dB HL on the contralateral side were implanted with an Osia. Analysis of clinical outcome data with respect to surgical technique, adverse events, audiological measurement, and subjective benefit for SSD patients was conducted. Audiological measurements performed included hearing thresholds, sound field thresholds, word recognition scores (WRS; in %) in quiet, and speech recognition thresholds in noise (in dB SNR). All tests were performed unaided and aided with the Osia. The subjective benefit with the Osia was determined by using 2 questionnaires; the Abbreviated Profile of Hearing Aid Benefit (APHAB) and the Bern Benefit in Single-Sided Deafness (BBSSD). RESULTS: Preliminary results indicate a straightforward surgical procedure with a low rate of complications and an improvement in speech perception in quiet, listening performance in everyday situations and patient satisfaction. However, in one of 6 subjects, a revision surgery had to be performed. CONCLUSION: Provided that SSD patients are open for CROS hearing, they can benefit from the Osia by reduced head shadow effects and better speech recognition. Special caution should be given to the skin at the site of implantation to avoid complications.

The First FDA Approved Early Feasibility Study of a Novel Percutaneous Bone Anchored Prosthesis for Transfemoral Amputees: A Prospective 1-year Follow-up Cohort Study.

OBJECTIVE: Evaluate the safety and efficacy of a novel press-fit bone-anchored prosthesis in an FDA approved study. DESIGN: Single-center, prospective 1-year follow-up cohort study of a percutaneous bone anchored prosthesis. SETTING: Veterans Health Administration Hospital. PARTICIPANTS: Ten male Veterans with unilateral transfemoral amputation that occurred at least 6 months prior to enrollment and was not the result of dysvascular disease (N=10). INTERVENTIONS: All participants received the novel press-fit Percutaneous Osseointegrated Prosthesis (POP) and a minimum of 10 days supervised rehabilitation therapy. OUTCOME MEASURES: Adverse events and radiographs were collected to assess device safety. Temporal assessments of bone density, stomal skin, prosthetic don/doff, functional ambulation, and patient-reported outcome compared our POP to a socket suspension system. RESULTS: Ten male participants mean age 48.8±12.1 years (range, 32-68 y) with mean time since amputation of 9.4± years (range 1-18 y) completed a two-staged implantation protocol and progressed to ambulation with an assistive device by post-operative day 14. Eight of 10 completed all study procedures. One implant loosened at 5 weeks, requiring removal. A second was removed after periprosthetic fracture from a non-device-related fall at 28 weeks. One patient required oral antibiotics for superficial infection. There were significant (P<.05) increases in bone density in the lumbar spine and adjacent to the distal porous coating with no radiographic evidence of bone resorption. Compared to the socket system, the use of POP significantly (P<.05) reduced prosthetic don and doff times and patient-reported prosthetic problem scores. Significant improvements (P<.05) in mean mobility, global health, and walking test scores were also observed. CONCLUSIONS: Improvements in bone density, function, and patient reported outcomes were observed with the POP device when compared to a socket suspension system. This Early Feasibility Study established initial safety and effectiveness of the POP device, supporting expanded investigation as an alternative to socket prostheses.

What Are the Risk Factors for Mechanical Failure and Loosening of a Transfemoral Osseointegrated Implant System in Patients with a Lower-limb Amputation?

BACKGROUND: Septic loosening and stem breakage due to metal fatigue is a rare but well-known cause of orthopaedic implant failure. This may also affect the components of the osseointegrated implant system for individuals with transfemoral amputation who subsequently undergo revision. Identifying risk factors is important to minimize the frequency of revision surgery after implant breakage. QUESTIONS/PURPOSES: (1) What proportion of patients who received an osseointegrated implant after transfemoral amputation underwent revision surgery, and what were the causes of those revisions? (2) What factors were associated with revision surgery when stratified by the location of the mechanical failure and (septic) loosening (intramedullary stem versus dual cone adapter)? METHODS: Between May 2009 and July 2015, we treated 72 patients with an osseointegrated implant. Inclusion criteria were a minimum follow-up of 5-years and a standard press-fit cobalt-chromium-molybdenum (CoCrMb) transfemoral osseointegrated implant. Based on that, 83% (60 of 72) of patients were eligible; a further 3% (2 of 60) were excluded because of no received informed consent (n = 1) and loss to follow-up (n = 1). Eventually, we included 81% (58 of 72) of patients for analysis in this retrospective, comparative study. We compared patient characteristics (gender, age, and BMI), implant details (diameter of the intramedullary stem, length of the dual cone, and implant survival time), and event characteristics (infectious complications and distal bone resorption). The data were retrieved from our electronic patient file and from our cloud-based database and analyzed by individuals not involved in patient care. Failures were categorized as: (1) mechanical failures, defined as breakage of the intramedullary stem or dual-cone adapter, or (2) (septic) loosening of the osseointegrated implant. RESULTS: Thirty-four percent (20 of 58) of patients had revision surgery. In 12% (7 of 58) of patients, the reason for revision was due to intramedullary stem failures (six breakages, one septic loosening), and in 22% (13 of 58) of patients it was due to dual-cone adaptor failure (10 weak-point breakages and four distal taper breakages; one patient broke both the weak-point and the dual-cone adapter). Smaller median stem diameter (failure: 15 mm [interquartile range 1.3], nonfailure: 17 mm [IQR 2.0], difference of medians 2 mm; p < 0.01) and higher median number of infectious events (failure: 6 [IQR 11], nonfailure: 1 [IQR 3.0], difference of medians -5; p < 0.01) were associated with revision intramedullary stem surgery. No risk factors could be identified for broken dual-cone adapters. CONCLUSION: Possible risk factors for system failure of this osteointegration implant include small stem diameter and high number of infectious events. We did not find factors associated with dual-cone adapter weak-point failure and distal taper failure, most likely because of the small sample size. When treating a person with a lower-limb amputation with a CoCrMb osseointegrated implant, we recommend avoiding a small stem diameter. Further research with longer follow-up is needed to study the success of revised patients. LEVEL OF EVIDENCE: Level III, therapeutic study.

What Are the Long-term Surgical Outcomes of Compressive Endoprosthetic Osseointegration of the Femur with a Minimum 10-year Follow-up Period?

BACKGROUND: Endoprosthetic reconstruction after oncologic resection of bone tumors requires stable fixation between the prosthesis and residual host bone. Compressive osseointegration has been developed as an alternative to traditional stemmed implants to address the challenges and complications of achieving this fixation. Sufficient time has now passed from the advent of compressive implants to allow for an assessment of the intermediate-term and long-term results of this form of fixation. QUESTIONS/PURPOSES: At a minimum follow-up of 10 years after implantation of a compressive osseointegration device for oncologic reconstruction: (1) What is the risk of periprosthetic fracture, aseptic loosening, or implant breakage resulting in revision surgery for endoprosthesis removal? (2) What is the long-term cortical response at the host-endoprosthesis interface as visualized on plain radiographs? METHODS: A single-center, retrospective study was performed between 2002 and 2010, in which 110 patients with primary bone sarcoma of the proximal or distal femur were considered for oncologic resection and reconstruction. Patients were considered for a compressive osseointegration endoprosthesis if they were 50 years of age or younger, had not previously received femoral radiation, had no metabolic disease impairing bone healing, were not diagnosed with metastatic disease, and had life expectancy greater than six months. Of the 110 patients, 25 were treated with a compressive osseointegration implant of the proximal or distal femur, and 85 patients were treated with conventional stemmed implants or amputation because of older age, advanced disease, metabolic comorbidities, inability to tolerate a nonweightbearing postoperative period, or in the case of rotationplasty, patient preference. All patients who received this device during the period of study were considered eligible for inclusion in this review. The median (range) age was 18 years (7 to 50), and 13 of 25 patients were men. Five patients died of disease before the minimum follow-up duration of 10 years; two underwent amputation due to local recurrence and three died with the implant in situ, leaving 20 patients for complete analysis. Median follow-up was 144 months, and all 20 surviving patients had a minimum follow-up of 10 years (121 to 230 months). The primary endpoint was reoperation and implant removal for periprosthetic fracture, aseptic loosening, or mechanical breakage of any component of the compressive device in the endoprosthesis. In final analysis, death was considered a competing event to revision surgery, and cumulative incidence was reported after competing-event analysis. A secondary aim was radiographic evaluation of the host-implant interface to assess the long-term cortical response to compressive osseointegration. RESULTS: Spindle fracture or loosening was noted in three patients, and the remaining 17 patients maintained the compression device until the final follow-up. The risk of reoperation for aseptic loosening, periprosthetic fracture, or mechanical breakage of the implant using a competing risks estimator was 12% at 10 years (95% CI 0% to 26%). These complications occurred within 29 months of the index surgery; no patients had implant loosening or mechanical breakdown after this initial period. On radiographic assessment, 14 patients demonstrated cortical hypertrophy of the bone-implant interface, six patients had maintenance of the native cortical contour, and no patients had cortical atrophy or narrowing at the implant interface.Conclusion Long-term follow-up in patients with compressive osseointegrative endoprosthetic devices demonstrated no late revisions because of periprosthetic fracture, aseptic loosening, or implant breakage in this cohort with a minimum 10-year follow-up. There was no evidence of late-onset cortical atrophy or stress shielding at the host-implant interface. This study supports the long-term stability of the interface between host bone and the endoprosthesis in compressive osseointegration devices. LEVEL OF EVIDENCE: Level IV, therapeutic study.

The influence of antineoplastic agents on the peri-implant bone around osseointegrated titanium implants: an in vivo histomorphometric and immunohistochemical study.

BACKGROUND AND OBJECTIVE: The interaction between antineoplastic drugs used for treating cancer and non-affected tissues remains poorly assessed and may be critical for maintaining the quality of life for patients during and after treatment. This pre-clinical study evaluated the effects of cisplatin (CIS) and 5-fluorouracil (5-FU) on the peri-implant repair process around osseointegrated titanium implants installed in the tibiae of rats. MATERIAL AND METHODS: Were used 90 male rats, randomly divided into three groups (n = 30): physiological saline solution (PSS), CIS, and 5-FU. Titanium implants (4.0 × 2.2 mm) were inserted in both tibiae of all animals at day 0. The animals received either PSS, CIS, or 5-FU at 35 and 37 days. Euthanasia was performed at 50, 65, and 95 days after surgery. Histometric (bone/implant contact [BIC]) and bone area fraction occupancy (% BAFO), histological, and immunohistochemical (for bone morphogenetic protein 2/4 [BMP2/4], Runt-related transcription factor 2 [RUNX2], osteocalcin [OCN], and tartrate-resistant acid phosphatase [TRAP]) analyses were performed. Data were statistically analyzed. RESULTS: Groups CIS and 5-FU presented lower BIC and lower BAFO as compared with PSS in all time points. The imbalance in bone turnover was observed by the lower number of BMP2/4-, RUNX2-, and OCN-positive cells/mm2 and the higher number of TRAP-positive cells/mm in groups CIS and 5-FU as compared with PSS in all time points. Persistent and exacerbated inflammation was observed in groups CIS and 5-FU. CONCLUSIONS: Both antineoplastic agents interfered negatively in the bone turnover around osseointegrated titanium implants. CLINICAL RELEVANCE: Closer and more careful follow-up of patients with osseointegrated implants that will undergo chemotherapy with either CIS or 5-FU shall be performed.