Suture Anchors

BackgroundBone-anchored hearing systems (BAHSs) are widely used for hearing rehabilitation and are indicated in cases of conductive and mixed hearing loss and in single-sided deafness. The Ponto system, that is one available option, has been on the market since 2009.Objective of reviewThe aim of this study is to systematically review the literature reporting on the Ponto system, with regard to audiological and surgical outcomes and patient's quality-of-life scores.Type of reviewA systematic literature search was performed in the PubMed database 2009-July 2019.Search strategySearch term: ((osseointegrated hearing aid) OR (bone conduction implant) OR (bone anchored hearing) OR BAHA OR BAHS OR BAHI). Pre-defined inclusion and exclusion criteria were applied.Evaluation methodEnglish-language articles reporting original clinical data (audiological, surgical or quality-of-life outcomes) on the Ponto system were included. Articles reporting on Ponto and another BAHS system where the results on Ponto constituted less than 50% of the patient population or including only results on testband or softband devices were excluded.ResultsAudiological outcomes were discussed in 20 publications. Improvement against the unaided thresholds was demonstrated. The functional improvement was on average 33.9 dB. The effective gain or remaining air-bone gap was on average 6.7 dB. All evaluated data showed aided speech reception thresholds significantly below normal speech level. Twenty-seven publications reported surgical and follow-up data for the Ponto system. Implant survival was 97.7%, adverse skin reactions (Holgers ≥ 2) were 5% across visits and 15% across patients. No complications were life-threatening, causing permanent disability/damage or requiring a hospitalisation. Five studies reported quality of life using the Glasgow benefit inventory, 98% reported an improvement when analysing the score on an individual level.ConclusionsThe outcomes of this systematic review confirm that percutaneous systems provide consistent audiological benefits and improved quality of life for patients. Further, the review demonstrates that the percutaneous systems are safe, with relatively low complication rates. Skin-related complications are the most common complication type and are experienced by approximately one patient out of seven, or in less than one of 20 follow-up visits.

PurposeTo evaluate the influence of cortical and cancellous bone structure on the biomechanical properties of all-suture and conventional anchors and compare the morphological bone damage after their failure. The hypothesis of the study is that all-suture anchor pullout is less invasive and that the pullout force is influenced by the cortical thickness.MethodsThirty human humeri were biomechanically tested as follows: starting with a load cycle from 20 to 50 N, a stepwise increase of the upper peak force by 0.05 N for each cycle at a rate of 1 Hz was performed. Analysis included maximum pullout strength for three different anchor implantation angles (45°, 90°, 110°) of the two anchor types. After anchor pullout, every sample underwent micro-CT analysis. Bone mineral density (BMD) and cortical thickness were determined at the anchor implantation site. Furthermore, the diameter of the cortical defect and the volume of the bone cavity were identified.ResultsThe maximum pullout strength of all-suture anchors demonstrates a strong correlation to the adjacent cortical thickness (r = 0.82, p ≤ 0.05) with at least 0.4 mm needed to withstand 200 N. No correlation could be seen in conventional anchors. Moreover, no correlation could be detected for local BMD in both anchors. All-suture anchors show a significantly narrower cortical defect as well as a smaller bone cavity following pullout (4.3 ± 1.3 mm vs. 5.3 ± 0.9 mm, p = 0.037; 141 mm3 vs. 212 mm3; p = 0.009). The cortical defect is largest if the anchors are placed at a 45° angle.ConclusionIn contrast to conventional anchors, the pullout force of all-suture anchors depends on the thickness of the humeral cortex. Furthermore, all-suture anchors show a significantly smaller cortical defect as well as decreased bone damage in the case of pullout. Therefore, the clinical implication of this study is that all-suture anchors are advantageous due to their bone preserving ability. Also, intraoperative decortication should not be performed and cortical thickness should be preoperatively evaluated to decrease the risk of anchor failure.

Biomechanical studies have shown the use of suture anchors (SA) to be superior to the traditional transosseous sutures (TS) in the repair of quadriceps tendon rupture (QTR). This study aimed to analyze and compare the functional outcomes of patients treated for quadriceps tendon ruptures using suture anchors or transosseous sutures. Patients having undergone suture anchor repair or transosseous suture repair for quadriceps tendon rupture between 2010 and 2015 at one of the two participating hospitals were included. Patients from site A underwent TS repair (TS group) while patients from site B underwent SA repair (SA group). Exclusion criteria included previous or concomitant injuries of the involved knee, penetrating injuries and pre-existing neurological conditions. Clinical outcome was assessed by subjective scores (Lysholm and Tegner Scores, International Knee Documentation Committee (IKDC) Score, Visual Analog Scale (VAS) for pain), quadriceps isokinetic strength testing, Insall-Salvati Index (ISI), and physical examination. Non-parametrical statistical analysis was conducted using the Mann-Whitney U test. Twenty-seven patients were included in the study of which 17 patients (63%) were available for follow-up (SA group: 9, TS group: 8). All patients were male with a mean age of 62.7 (SD: 8.8) and 57.9 (SD: 12.7) years for the SA group and TS group, respectively. The groups did not differ in terms of demographic characteristics. No clinically significant differences were identified between the two groups. There were no re-ruptures in either group. Treatment of quadriceps tendon rupture using suture anchors provides a clinically valid alternative treatment to the gold-standard transosseous suture repair.

The rotator cuff plays a vital role in shoulder movement and joint stability. Unfortunately, tears at the rotator cuff enthesis are common and frequently lead to retears after surgical intervention, particularly at the suture location and its anchor sites. These failures are typically due to the inability of current surgical treatments to mimic the native tissue complexity and provide the necessary metabolic, bioactive, and biophysical cues for effective enthesis regeneration. In this study, we engineered a biomimetic multiphasic scaffold system (BMS) to integrate with conventional suture anchor systems and deliver spatially organized structural and biological cues to enhance enthesis regeneration. The BMS consists of three distinct phases: Phase 1 features an aligned, nanofibrous decellularized tendon extracellular matrix (dECM) combined with "stiff" methacrylated hyaluronic acid (MeHA); phase 2 incorporates nonaligned, nanofibrous dECM with "soft" MeHA; and phase 3 uses a porous, bioenergetic, citrate-based composite scaffold for bone integration. In vitro, the BMS notably enhanced tenogenic, fibrochondrogenic, and chondrogenic differentiation, facilitating zone-specific rotator cuff enthesis regeneration. Further, in vivo, the BMS promoted successful integrative healing, forming distinct tendon, fibrocartilage, and bone regions at the repair site. This advanced multiphasic scaffold closely replicates native tissue properties, offering a promising strategy to improve rotator cuff repair. Its integration with conventional suture anchors provides an innovative design that enhances mechanical fixation and guides enthesis healing to reduce retear rates. Broadly, this platform offers a versatile solution for biointegrative repair strategies across complex soft-to-hard tissue interfaces.