Fixation technique of biodegradable magnesium alloy suture anchor in the rotator cuff repair of the shoulder in a goat model: a technical note.

BACKGROUND: Shoulder disorders, particularly rotator cuff tears, are prevalent musculoskeletal conditions related to aging. Although the widely used suture anchor technique provides strong mechanical support to the tendon, it is associated with a risk of postoperative tendon retearing. The conventionally used titanium alloys can affect the interpretation of magnetic resonance imaging. Degradable magnesium alloys possess excellent biocompatibility, similar mechanical property to the bone, and stimulating bone formation ability from Mg2+. The purpose of this experiment was to develop innovative magnesium-based suture anchors to enhance rotator cuff repair by improving fixation materials, and to evaluate their feasibility in a goat model. METHODS: We developed fluoridized ZK60 suture anchors as the implantation material for two goats, who underwent rotator cuff repair surgery on both shoulders. Computed tomography (CT) and histological analysis were performed at 12 weeks postoperatively, and the results were compared between the magnesium and titanium alloy groups. Additionally, a hematological examination was conducted, which included assessments of red blood cells, white blood cells, platelets, coagulation function, liver function, kidney function, and magnesium ion concentration. RESULTS: The 12-week postoperative CT images showed intact MgF2 ZK60 suture anchors, effectively reconnecting the infraspinatus tendon to the humeral head. The anchors became less visible on CT scans, indicating absorption by surrounding tissues. New bone formation in the MgF2 group surpassed that in the Ti group, demonstrating superior osseointegration. The similarity between cortical bone and magnesium reduced stress-shielding and promoted bone regeneration. Histological analysis revealed successful tendon healing with MgF2 anchors, while the Ti group showed discontinuous interfaces and reduced collagen secretion. Hematological examination showed stable liver, renal function, and magnesium ion levels. CONCLUSIONS: The findings indicate that MgF2-coated suture anchors are feasible for rotator cuff repair and potentially other orthopedic applications. We hope that magnesium alloy anchors can become the solution for rotator cuff tendon repair surgery.

Efficacy of Different Methods of Bone-Anchored Maxillary Protraction in Cleft Lip and Palate Children: A Systematic Review and Meta-Analysis.

INTRODUCTION: Bone-anchored maxillary protraction (BAMP) is an effective option for adolescent cleft patients with maxillary hypoplasia. Hence, this study was conducted to access the effectiveness of the many techniques of BAMP in cleft lip and palate patients. METHODS AND MATERIALS: Data was compiled through a global search of random and nonrandom studies that investigated the efficacy of various techniques of BAMP in cleft lip and palate patients. The searches were conducted in ISI Web of Science, EMBASE, Scopus, Medline, and Cochrane Central Register of Controlled Trials from the beginning until October 12, 2021. The pertinent data of the comprised studies were extracted using predetermined extraction forms. Meta-analysis results were obtained by using inverse-variance to calculate the pooled results of the outcome measures. RESULTS: Five studies were submitted for meta-analysis. The BAMP therapeutic methods investigated in the studies were facemask attached to miniplates (FM-MP) and class III elastics attached to maxillary and mandibular miniplates (C3-IE: class III intermaxillary elastic). The mean differences of A-VRP, A-N Prep., ANB, wits, overjet, and SNA landmarks indicated posttreatment was encouraging, showing maxillary protrusion, and correction of class III malocclusion. SNB landmark showed no statistically significant alterations posttreatment. Subgroup analysis of the C3-IE and FM-MP subgroups indicated that the changes in ANB, SNA, and overjet parameters in the FM-MP subgroup were more pronounced than in the C3-IE subgroup. No statistically significant differences were found when the results of these 2-treatment method were compared, except for in the overjet subgroup. CONCLUSION: After undergoing BAMP treatment, the maxilla showed a more horizontal growth, but no changes in the vertical dimension were observed and the mandible did not rotate clockwise. In addition, using facemask-miniplates was more effective in increasing overjet compared with using class III elastics with bone anchors. In conclusion, BAMP treatment is a suitable alternative for adolescents with cleft lip and palate malformation.

Knotless PEEK and double-loaded biodegradable suture anchors ensure comparable clinical outcomes in the arthroscopic treatment of traumatic anterior shoulder instability: a prospective randomized study.

PURPOSE: To compare the clinical outcome of arthroscopic capsulolabral repair for traumatic anterior shoulder instability with PEEK knotless and knotted biodegradable suture anchors. METHODS: Arthroscopic stabilization was performed in 78 patients with recurrent traumatic anterior shoulder instability. They were divided into 2 groups of 39 patients each, according to suture anchors used: knotless PEEK anchors in group 1, and biodegradable anchors in group 2. Exclusion criteria were: instability without dislocation, posterior or multidirectional instability, glenoid bone loss > 20%, off-track lesions, concomitant rotator cuff tears and previous surgery. The primary outcome was the Disabilities of the Arm, Shoulder and Hand (DASH) self-administered questionnaire. Secondary outcomes were: Work-DASH, Sport-DASH, Rowe score, recurrent instability and subsequent surgery. The following independent variables were considered: age, gender, dominance, generalized ligamentous hyperlaxity, duration of symptoms, age at first dislocation, number of dislocations, type of work, type of sport, sports activity level, capsule-labral injury pattern, SLAP lesion and number of anchors. Differences between groups for numerical variables were analyzed by use of the Student's t-test or Mann-Whitney U-test. Fisher's exact test was used for analysis of categorical variables. Significance was set at p < 0.05. RESULTS: Seven patients (9%) were lost at follow-up, 5 from group 1 and 2 from group 2. Follow-up ranged from 36 to 60 months (median: 44; IQR: 13). Comparison between groups did not show significant differences for each independent variable considered. No differences could be found either for DASH (n.s.) or Rowe (p = n.s.) scores between the two groups. Overall recurrence rate was 7%. Three re-dislocations were reported in group 1 and two in group 2 (n.s.). Only one patient in each group underwent re-operation. CONCLUSIONS: The study showed no significant differences in clinical outcomes after arthroscopic treatment of traumatic anterior shoulder instability using PEEK knotless or biodegradable knotted anchors at mid-term follow-up. LEVEL OF EVIDENCE: I.

Mini suture anchor: An effective device for reduction and fixation of displaced temporomandibular joint disc with intracapsular condylar fracture.

PURPOSE: The main aim is to provide clinical reference for the application of mini suture anchor in the reduction and fixation of displaced temporomandibular joint (TMJ) disc with intracapsular condylar fracture. METHODS: From October 2018 to October 2019, 21 patients (31 sides) with intracapsular condylar fractures and articular disc displacement from West China Hospital of Stomatology, Sichuan University were included. The selection criteria were: (1) mandibular condylar fractures accompanied by displacement of the TMJ disc, confirmed by clinical examination, CT scan and other auxiliary examinations; (2) indication for surgical treatment; (3) no surgical contraindications; (4) no previous history of surgery in the operative area; (5) no facial nerve injury before the surgery; (6) informed consent to participate in the research program and (7) complete data. Patients without surgical treatment were excluded. The employed patients were followed up at 1, 3, 6 and 12 months after operation. Outcomes were assessed by success rate of operation, TMJ function and radiological examination results at 3 months after operation. Data were expressed as number and percent and analyzed using SPSS 19.0. RESULTS: All the surgical procedures were completed successfully and all the articular discs were firmly attached to the condyles. The articular disc sufficiently covered the condylar head after the fixation. The fixation remained stable when the mandible was moved in each direction by the surgeons. No complications occurred. The functions of the TMJ were well-recovered postoperatively in most cases. CT scan revealed that the screws were completely embedded in the bone without loosening or displacement. CONCLUSION: Mini suture anchor can provide satisfactory stabilization for the reduced articular disc and also promote the recovery of TMJ functions.

Novel and reproducible technique coping with intraoperative anchor pullout during arthroscopic rotator cuff repair.

PURPOSE: To evaluate the incidence of intraoperative anchor pullout during arthroscopic rotator cuff repair, to compare the outcomes of different methods of managing anchor pullout, and to introduce a new technique for anchor pullout. METHODS: 1076 patients who underwent arthroscopic rotator cuff repair using a single-row repair technique were included. In 483 patients, rotator cuff repair was performed using a screw-in type anchor, and in 593 patients, soft anchors were used. When intraoperative anchor pullout occurred, it was managed by buddy screwing, anchor insertion in a different location, cement augmentation, or by bar anchoring using a threaded Steinmann pin. Plain radiography and sonography were used to check anchor locations and healing. RESULTS: Fifty-two patients experienced anchor pullout intra- or postoperatively (48 and four patients, respectively). Anchor pullouts were more frequently observed for larger tears, women, older patients, and in patients with preoperative stiffness (limitations of both active and passive movements of the affected shoulder joint). For screw-in type anchors, pullout during surgery occurred in 16 patients (3.3%, 16/483), and all were managed using the buddy screwing technique. For soft anchor cases, pullout occurred in 32 patients (5.4%, 32/593) and was managed by anchor insertion in a different location (17 patients), cement augmentation (two patients), or bar anchoring using a threaded Steinmann pin (13 patients). Three patients managed by buddy screwing and two patients managed by anchor insertion in a different location had anchor failure after repair. Tendon healing at 6 months was observed in 12/16 patients treated by buddy screwing, 11/17 treated by anchor insertion in a different location, 2/2 treated by cement augmentation, and 12/13 treated by bar anchoring with a threaded Steinmann pin. CONCLUSION: Intraoperative anchor pullout during arthroscopic rotator cuff repair is an uncommon but cumbersome complication. There are some techniques already introduced to deal with this complication. In comparison, not one technique is overwhelmingly superior to others; however, our new technique which is bar anchoring with a threaded Steinmann pin could be another solution, since it could utilize primary anchor sites and results appear to be acceptable. Level of evidence III.

Postoperative bone marrow edema lasts no more than 6 months after uncomplicated arthroscopic double-row rotator cuff repair with PEEK anchors.

PURPOSE: To assess the natural evolution of the osseous reaction following arthroscopic double-row rotator cuff repair with PEEK anchors and to analyze its correlation with clinical shoulder function. METHODS: Between 2015 and 2017, 159 patients received arthroscopic double-row rotator cuff repair with PEEK anchors and underwent serial clinical and radiological follow-up (3, 6, 12, and 24 months). Radiological results were analyzed by tendon integrity, bone marrow edema, and peri-implant osteolysis. Clinical shoulder function was evaluated with the Constant score. RESULTS: One-hundred and seventeen patients were enrolled; among them, 63% demonstrated bone marrow edema around the anchors on postoperative 3-month MRI. The edema area percentage was 41% ± 7%. At 6 months, edema was only seen in 12% of cases, with an area percentage of 18% ± 5%. At 12 and 24 months, edema was rarely present. Fluid signals around the anchor were observed in 17.6%, 42.7%, 33.3%, and 21.0% of patients at 3, 6, 12, and 24 months, respectively; the tunnel widening values were 1.1 ± 0.4 mm, 1.8 ± 0.5 mm, 2.3 ± 0.6 mm, and 2.2 ± 0.7 mm at each follow-up, respectively. The sign of osteolysis was significantly more obvious around the lateral anchor than around the medial anchor. The presence of an osseous reaction was not correlated with worse clinical outcome. CONCLUSION: Osseous reactions following arthroscopic rotator cuff repair are common and significant even with PEEK anchors. Bone marrow edema does not last more than 6 months in patients without complications. Peri-implant osteolysis is more evident around the lateral anchor than around the medial anchor and improves gradually over time. The sign of osteolysis is not correlated with clinical shoulder function. Based on these findings, surgeons should be cautious about bone marrow edema lasting more than 6 months following arthroscopic rotator cuff repair. LEVEL OF EVIDENCE: Level IV.

Regenesorb and polylactic acid hydroxyapatite anchors are associated with similar osseous integration and rotator cuff healing at 2 years.

BACKGROUND: Commercially available suture anchors for rotator cuff repairs can differ significantly in architecture and material. Clinical data on their osseous integration and its effect on patient-reported outcomes is scarce. Preclinical investigations indicated a higher rate of osseous integration for the open-architecture design of the Healicoil Regenesorb anchor than the closed-threaded design of the Twinfix (Smith & Nephew). The purpose of this study was to investigate these 2 anchors with different architecture and material to determine their effect on osseous integration and clinical outcomes after rotator cuff repair. METHODS: A prospective randomized controlled trial was performed from 2014 to 2019. Sixty-four patients (39 females, 25 males) with an average age of 58.7 years who underwent arthroscopic rotator cuff repair by one of 4 board-certified, fellowship-trained surgeons were randomized to receive Healicoil Regenesorb (PLGA/ß-TCP/Calcium Sulfate) or Twinfix Ultra HA (PLLA/HA) anchors. Thirty-two patients had Healicoil anchors implanted, and 32 patients had Twinfix anchors implanted. Of the 64 patients, 51 returned at 24 months for computed tomographic (CT) examination (25 Twinfix and 26 Healicoil) to determine osteointegration of the anchors. Patient-reported outcomes, including Penn Shoulder Score (PENN), Western Ontario Rotator Cuff Index, visual analog scale, EQ-5D, Single Assessment Numeric Evaluation, Global Rating of Change, were collected at baseline, 6 weeks, 3 months, 6 months, 12 months, and 24 months. Ultrasonography was used to assess rotator cuff integrity after 6 months. Two board-certified, fellowship-trained orthopedic surgeons, blinded to the type of anchors, analyzed the CT scans to assess the anchor osteointegration at 24 months using a previously published grading scale. RESULTS: There were no differences in demographics, preoperative outcomes, or baseline characteristics such as tear size, number of anchors, Goutallier classification, or smoking status between groups. There was no difference in osseous integration between the 2 anchors at 24 months (P = .117). Eight patients had rotator cuff retears, of which 2 patients had Twinfix anchors and 6 patients had Healicoil anchors (P = .18). There were no statistically significant differences in patient-reported outcomes or complications between groups. The 2-year PENN scores were 89 with the Twinfix and 88 with Healicoil anchors (P = .55). CONCLUSION: Despite differences in material and anchor architecture, the rate of healing and patient-reported outcomes were similar between the Twinfix and Healicoil anchor groups. The rate of osteointegration was the same at 2 years.

Biocompatibility and Biological Performance Evaluation of Additive-Manufactured Bioabsorbable Iron-Based Porous Suture Anchor in a Rabbit Model.

This study evaluated the biocompatibility and biological performance of novel additive-manufactured bioabsorbable iron-based porous suture anchors (iron_SAs). Two types of bioabsorbable iron_SAs, with double- and triple-helical structures (iron_SA_2_helix and iron_SA_3_helix, respectively), were compared with the synthetic polymer-based bioabsorbable suture anchor (polymer_SAs). An in vitro mechanical test, MTT assay, and scanning electron microscope (SEM) analysis were performed. An in vivo animal study was also performed. The three types of suture anchors were randomly implanted in the outer cortex of the lateral femoral condyle. The ultimate in vitro pullout strength of the iron_SA_3_helix group was significantly higher than the iron_SA_2_helix and polymer_SA groups. The MTT assay findings demonstrated no significant cytotoxicity, and the SEM analysis showed cells attachment on implant surface. The ultimate failure load of the iron_SA_3_helix group was significantly higher than that of the polymer_SA group. The micro-CT analysis indicated the iron_SA_3_helix group showed a higher bone volume fraction (BV/TV) after surgery. Moreover, both iron SAs underwent degradation with time. Iron_SAs with triple-helical threads and a porous structure demonstrated better mechanical strength and high biocompatibility after short-term implantation. The combined advantages of the mechanical superiority of the iron metal and the possibility of absorption after implantation make the iron_SA a suitable candidate for further development.

Does Repositioning of Temporomandibular Joint Disc With Bone Anchors Provide Better Clinical Outcomes Than Conventional Disc Plication Procedures for Anterior Disc Displacements Without Reduction in Patients Refractory to Nonsurgical Treatments?

PURPOSE: Although open temporomandibular joint arthroplasty with discopexy is a common treatment for patients with anterior disc displacements without reduction (ADDWo) unresponsive to medical management, there are no studies comparing disc repositioning with bone anchors and conventional discopexy procedure. The purpose of the study was to compare the efficacy between disc repositioning with bone anchors and the conventional discopexy procedure for ADDWo of temporomandibular joint refractory to medical management. PATIENTS AND METHODS: A randomized controlled trial was conducted in patients with ADDWo. The primary objective was to compare the improvement in mouth opening (primary outcome variable) between the 2 treatment (primary predictor variable) groups-disc repositioning with bone anchors versus conventional disc plication. Secondary outcome variables were pain measured by visual analog scale, lateral excursions, and position of the disc evaluated by magnetic resonance imaging (MRI). Other variables of interest were age, gender, and duration of symptoms. The parameters were evaluated at preoperative, postoperative day 1, and 1-, 6-, and 12-month postoperative period. Categorical variables were compared with χ2 test and continuous variables with analysis of variance and adjusted for multiple comparisons with Bonferroni test. RESULTS: The study sample comprised 14 patients (7 in each group) with MRI-proven ADDWo. Statistically significant differences were found in the improvement of mouth opening between the 2 groups, showing better improvement with bone anchors (14.42 ± 5.96 vs 7.57 ± 7.25 mm; P < .05). The reduction in visual analog scale also showed statistically significant difference with better pain reduction achieved with bone anchor (4.57 ± 1.61 vs 3.28 ± 0.75; P < .05). There was no statistically significant difference in lateral excursions and postoperative position of the disc evaluated by MRI between the groups at the 12-month follow-up period. CONCLUSIONS: Disc repositioning with bone anchors provides better clinical outcomes in terms of maximal mouth opening and pain scores compared with conventional disc plication.

Editorial Commentary: Taking a "PEEK" at Suture Anchor Composition following Arthroscopic Rotator Cuff Repair: Is Bio Really Better?

The advent of modern suture anchor technology has not only revolutionized arthroscopic treatment options for management of complex shoulder pathology, but also engendered a materials science quest to identify the ultimate composition and design. What began as an open procedure with transosseous suture fixation has evolved dramatically with the widespread adoption of an arthroscopic, anchor-based technique for rotator cuff repair. Currently, a litany of commercially available "hard" and "soft" anchors are flooding the market, with limited qualitative comparisons to suggest superiority of one type. Ideally, suture anchor design should permit preservation of native glenohumeral bone stock with gradual osseointegration, limit disruption of local tissue homeostasis, and maintain time-zero mechanical strength until soft-tissue healing has occurred. At present, a vented, open-anchor architecture may facilitate better biologic incorporation with increased bony ingrowth through access to marrow elements, although these radiographic advantages have not conferred any clinically meaningful differences for our rotator cuff repair patients. For anchor composition, the jury is still out, and we need to continue to critically evaluate for perianchor cyst formation and longer term remodeling. In fact, the true merits of increased bony ingrowth and limited osteolysis may only be realized at the time of revision rotator cuff repair, during which prior implant position or secondary cystic change may further dictate suture anchor design, size, and placement.

Calcium Phosphate Bone Void Filler Increases Threaded Suture Anchor Pullout Strength: A Biomechanical Study.

PURPOSE: To compare the response to cyclical loading and ultimate pull-out strength of threaded suture anchor with and without calcium phosphate bone void filler augmentation in a polyurethane foam block model and in vitro proximal humerus cadaveric model. METHODS: This controlled biomechanical study consisted of 2 parts: (1) preliminary polyurethane foam block model, and (2) in vitro cadaveric humeri model. The preliminary foam block model intended to mimic osteoporotic bone using a 0.12 g/mL foam material. Half of the foam block models were first filled with injectable calcium phosphate bone substitute material (CP-BSM), whereas the other half were not augmented with CP-BSM. Each specimen was then instrumented with a threaded suture anchor. The same technique and process was performed in a matched cadaveric humeri model. Testing then consisted of a stepwise, increasing axial load protocol for a total of 40 cycles. If the anchor remained intact after cyclic loading, the repair was loaded to failure. The number of completed cycles, failure load, and failure modes were compared between groups. RESULTS: Average pull-out strength for suture anchor with CP-BSM in the osteoporotic foam block model was significantly higher at 332.68 N ± 47.61 compared with the average pull-out strength of suture anchor without CP-BSM at 144.38 N ± 14.58 (P = .005). In the matched cadaveric humeri model, average pull-out strength for suture anchor with CP-BSM was significantly higher at 274.07 N ± 102.07 compared with the average pull-out strength of suture anchor without CP-BSM at 138.53 N ± 109.87 (P = .029). CONCLUSIONS: In this time zero, biomechanical study, augmentation of osteoporotic foam block and cadaveric bone with calcium phosphate bone substitute material significantly increases pull-out strength of threaded suture anchors. CLINICAL RELEVANCE: Considering concerns about suture anchor pull-out from osteoporotic bone, augmentation with calcium phosphate bone substitute material increases load to failure resistance.

Bony Ingrowth of Coil-Type Open-Architecture Anchors Compared With Screw-Type PEEK Anchors for the Medial Row in Rotator Cuff Repair: A Randomized Controlled Trial.

PURPOSE: To evaluate outcomes of screw-type and coil-type open-architecture suture anchors with respect to bony ingrowth, release of biological markers, and patient-reported outcome measures when used in rotator cuff repair (RCR). METHODS: Forty patients undergoing arthroscopic RCR for full-thickness rotator cuff tears were enrolled and prospectively randomized to receive a screw-type (19 patients) or coil-type (21 patients) suture anchor for the medial row during repair. All repairs used a transosseous-equivalent configuration with footprint anchors laterally. Marrow elements released during surgery were evaluated for 9 cytokine markers (insulin-like growth factor 1, fibroblast growth factor 2, bone morphogenetic proteins 7 and 2, platelet-derived growth factors AA and BB, epidermal growth factor, transforming growth factor beta1, and vascular endothelial growth factor). Postoperative computed tomography scans were performed at 6 months. Range of motion, strength, and validated patient-reported outcome measures (Simple Shoulder Test, Single Assessment Numeric Evaluation, visual analog scale, and American Shoulder and Elbow Surgeons scores) were gathered before the operation and at 6 months and 1 year postoperatively. RESULTS: Bone mineral density surrounding the coil-type anchor was significantly greater than that surrounding the screw-type anchor (P = .005). Bone mineral density values within the coil-type and screw-type anchors were comparable (P = .527); however, a larger amount of total bone mineral mass (in milligrams) was shown within the coil-type anchor owing to its larger volume (P < .01). Marrow elements released at the repair site were similar between groups (P > .05). Postoperatively, no statistically significant difference was found between groups for clinical outcome measures at 6 months or 1 year. Retear and complication rates were similar between groups (P > .05). CONCLUSIONS: Both the coil-type and screw-type anchors can be reliably used for RCR and produce similar clinical outcomes. The coil-type anchor resulted in superior bony growth surrounding the anchor and a larger total bone mineral mass within the anchor owing to its larger volume. LEVEL OF EVIDENCE: Level II, randomized prospective comparative study.

A Comparison of Open-Construct PEEK Suture Anchor and Non-Vented Biocomposite Suture Anchor in Arthroscopic Rotator Cuff Repair: A Prospective Randomized Clinical Trial.

PURPOSE: To compare radiologic bone ingrowth and the clinical outcomes of an open-construct (PEEK) (polyether ether ketone) suture anchor with those of a non-vented biocomposite suture anchor in patients with arthroscopic rotator cuff repair. METHODS: Sixty-nine patients were randomly allocated into 2 groups based on type of suture anchors used for rotator cuff repair; group 1: open-construct PEEK anchor (36 patients), group 2: non-vented biocomposite anchor (33 patients). The status of bone ingrowth into the anchor and the presence of cyst formation were evaluated at 6 months postoperatively by computed tomography scan using the Modified Barber's ossification scale. The American Shoulder and Elbow Surgeons score, Constant score, and visual analog scale score for pain and range of motion were evaluated. Magnetic resonance imaging or ultrasonography was performed at 12 months postoperatively to examine the integrity of the repaired rotator cuff tendon. RESULTS: Significant improvements in shoulder function and pain relief were observed regardless of the anchor used (both Group 1 and 2; P < .001). No differences were found in functional scores and range of motion between the 2 groups. Group 1 showed better bone ingrowth grades than group 2 (poor 2.8 vs 24.2%, fair 27.8 vs 39.4%, good 38.9 vs 33.3%, and excellent 30.6 vs 3.0%; P < .001). The rate of cyst formation around the anchor on the 6 months' postoperative computed tomography (group 1: 14% and group 2: 12%) and re-tear rate at 12 months (5% each) showed no difference between the 2 groups. CONCLUSIONS: Shoulder function was improved after complete rotator cuff repair and similar clinical outcomes were achieved regardless of suture anchor material and shape. However, the open-construct PEEK anchor provided better bone ingrowth into the anchor than the non-vented biocomposite anchor at 6 months after arthroscopic rotator cuff repair. LEVEL OF EVIDENCE: Level I; Prospective Randomized Trial.

Pullout strength and failure mode of industrially manufactured and self-made all-suture anchors: a biomechanical analysis.

BACKGROUND: This study presents a new technique for assembling an all-suture anchor from existing medical products. The biomechanical characteristics of this self-made anchor (SMA) are compared with those of an industrially manufactured all-suture anchor. METHODS: The SMAs were made from established medical products (FiberWire #2 and 2-mm FiberTape; Arthrex, Naples, FL, USA). Pretesting was performed in biphasic polyurethane foam blocks. In the next step, 10 SMAs and 10 industrially made anchors (IMAs; 1.8-mm double-loaded Y-Knot Flex all-suture anchor; ConMed Linvatec, Largo, FL, USA) were applied with an insertion tool and tested in fresh porcine femora using a servohydraulic testing system, with a preload of 10 N and a displacement rate of 12.5 mm/s. Pullout strength and failure mode were recorded. RESULTS: The mean load at failure in the foam blocks was 459 ± 124 N in the SMA group and 538 ± 83 N in the IMA group. In porcine bone, failure occurred at 461 ± 102 N in the SMA group and 431 ± 135 N in the IMA group. The differences in pullout strength between the 2 types of anchor were not statistically significant, either in the foam blocks (P = .17) or in porcine bone (P = .62). CONCLUSION: A handmade all-suture anchor using 2 high-strength sutures woven into a 2-mm strip of high-strength tape did not show statistically different failure loads in polyurethane foam or in porcine metaphyseal bone in comparison with a commercially produced double-loaded all-suture anchor. The principal mode of failure in porcine bone in both groups was anchor pullout.

Revisability of polyetheretherketone suture anchors utilised in primary and revision Bankart repair.

BACKGROUND: Polyetheretherketone (PEEK) suture anchors are frequently used in Bankart shoulder stabilisation. This study analyzed the primary stability and revisability of PEEK anchors in-vitro in case of primary Bankart repair and revision Bankart repair after failed primary repair. METHODS: To simulate primary Bankart repair, 12 anchors (Arthrex PEEK PushLock® 3.5 mm) were implanted in 1, 3, 5, 7, 9 and 11 o'clock positions in cadaveric human glenoids and then cyclically tested. To simulate revision Bankart repair, 12 anchors were implanted in the same manner, over-drilled and 12 new anchors of the same diameter were implanted into the same bone socket as the primary anchors and then cyclically tested. The maximum failure loads (Fmax), system displacements, force at clinical failure and modes of failure were recorded. RESULTS: One primary anchor failed prematurely due to a technical problem. Three out of 12 revision anchors (25%) dislocated while setting the 25 N preload. The Fmax, the displacement and clinical failure of the remaining 9 revision anchors were non-significant when compared to the 11 primary repair anchors. The main mode of failure in the primary and revision Bankart surgery group was suture slippage. Anchor dislocations were observed four times in the primary and once in the revision repair groups. CONCLUSIONS: Revision Bankart repair using PEEK anchors of the same diameter in a pre-existing bone socket is possible but bears high risk of premature anchor failure and can jeopardize the reconstruction. PEEK suture anchor in revision Bankart surgery should be implanted in a new bone socket if possible.

Biocomposite Suture Anchors Remain Visible Two Years After Rotator Cuff Repair.

BACKGROUND: Biocomposite suture anchors containing osteoconductive materials have gained popularity in rotator cuff repairs. However, little is known about the influence of the addition of osteoconductive materials on implant resorption, bone reaction, tendon healing, and clinical outcomes scores. QUESTIONS/PURPOSES: (1) What percentage of suture anchors were not completely resorbed 2 years after implantation? (2) What are the diameters of the bone bed in relation to the implant? (3) Is tendon integrity correlated with bone tunnel diameter? (4) Is there an association between tunnel widening, periimplant fluid film grade, biodegradation grade, and retear with clinical outcomes scores, such as the Western Ontario Rotator Cuff Index (WORC) and the Oxford Shoulder Score (OSS)? METHODS: Thirty-six patients were enrolled from August 2012 to January 2014. The following inclusion criteria were applied: (1) reparable full-thickness supraspinatus tendon tears, (2) double-row suture bridge techniques applied for supraspinatus repair, (3) use of biocomposites suture anchor implants composed of poly L-lactic acid (PLLA) and ß-tricalcium phosphate (TCP) exclusively, and (4) a minimum of 2 years followup. Four patients met the exclusion criteria, and seven of 36 patients (19%) were lost to followup. Thereby, 25 patients (84 implants) were included in this retrospective study. To answer the study's questions, the following methods were applied: (1) The resorption of the implants and periimplant fluid film were assessed on MRI using a four-stage scale system, (2) bone bed diameter was measured on MRI at three different points on the longitudinal central axis of each anchor, (3) tendon integrity was evaluated on MRI according to the Sugaya classification and correlated to bone tunnel diameter, and (4) assessed tunnel diameters, periimplant fluid film grade, biodegradation grade, and tendon condition were related to clinical outcomes scores at the time of followup (2.3 ± 0.3 years). The intraobserver reliability was 0.981 (p < 0.001) and interobserver reliability was 0.895 (p < 0.001). RESULTS: At 2.3 ± 0.3 years, most analyzed suture anchors (76 of 84 [90%]) were, with varying degrees of degradation, still visible. Bone tunnels showed minor widening (0.4 ± 1.4 mm) at the base, but osseous ingrowth was detected as narrowing at the middle (0.1 ± 1.1 mm) and at the apex (1.4 ± 1.7 mm) of the implants. Patients with retears (Sugaya Grades 4-5) had narrower tunnels (3.6 ± 1.8 mm) than patients without retears (Sugaya Grades 1-3; 4.4 ± 1.6 mm; mean difference, 0.782 [95% confidence interval {CI}: 0.009-1.6]; p = 0.050). WORC and Oxford scores were not associated with the tunnel widening amount, fluid film grade, biodegradation grade, or tendon retear. CONCLUSIONS: In light of the results of the present study, surgeons should consider in their daily practice that the resorption process of these implants may be slower than assumed so far, but no association with severe implant-related complications has been found in the short term. Future studies should focus on the evaluation of the effects of osteoconductive materials on resorption, tendon healing, and clinical outcomes in the long term and on the integration process in different rotator cuff reconstruction techniques. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Editorial Commentary: Perianchor Cysts-We Need More Worries After Rotator Cuff Repair Like We Need Holes in the Head.

Cysts or radiolucent rings are relatively common around suture anchors after rotator cuff repair. The rate of cyst occurrence is similar across anchor types and materials. Generally, perianchor cysts are benign and can be regarded as not affecting clinical outcomes.

Osteointegration of a Biocomposite Suture Anchor After Arthroscopic Shoulder Labral Repair.

PURPOSE: To evaluate osteoconductivity of a poly-L-lactide co-glycolide (PLG)-calcium sulfate (CS)-ß-tricalcium phosphate (ß-TCP) biocomposite suture anchor after arthroscopic shoulder labral repair. METHODS: The subjects of this study were patients who participated in a clinical trial for acquisition of marketing approval of a PLG-CS-ß-TCP biocomposite anchor in Japan. They underwent arthroscopic labral repair using the anchor, and computed tomographic (CT) images of the glenoid were obtained 2 years after surgery. Osteoconductivity at the anchor sites was evaluated with the CT images using the established ossification quality score. Shoulder function scores including the Rowe score and Japanese Shoulder Society shoulder instability score were also assessed 2 years after surgery. RESULTS: CT images and functional scores were obtained from 37 patients, comprising 29 men and 8 women with a mean age of 29 years (range, 25-33 years) at surgery. A total of 148 anchors were implanted in the 37 shoulders. Osteoconductivity was seen in 133 of 148 anchor sites (90.0%) 2 years after implantation. No significant differences in osteoconductivity were found by anchor diameter or position. The Rowe score significantly improved from 39.9 points (95% confidence interval [CI], 33.8-45.9 points) preoperatively to 96.6 points (95% CI, 95.1-98.1 points) at 2 years postoperatively (P < .001). The Japanese Shoulder Society shoulder instability score also significantly improved, from 63.1 points (95% CI, 58.4-67.7 points) preoperatively to 96.3 points (95% CI, 94.7-97.8 points) at 2 years postoperatively (P < .001). CONCLUSIONS: Biocomposite suture anchors made of PLG, CS, and ß-TCP exhibited some osteoconductivity 2 years after arthroscopic labral repair, as well as good clinical outcomes. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Comparison of Clinical Outcomes and Computed Tomography Analysis for Tunnel Diameter After Arthroscopic Bankart Repair With the All-Suture Anchor and the Biodegradable Suture Anchor.

PURPOSE: To compare the clinical outcomes and radiological findings at the anchor site after arthroscopic Bankart repair with all-suture anchors and biodegradable suture anchors in patients with recurrent anterior shoulder dislocation. METHODS: The patients who underwent arthroscopic Bankart repair were divided into 2 groups depending on the type of the suture anchor used in different periods. Power analysis was designed based on the postoperative Rowe score. Clinical outcomes, including the Rowe score, American Shoulder and Elbow Surgeons score, subjective instability, and redislocation rates were evaluated. In all patients enrolled, the tunnel diameter of the anchor was assessed with computed tomography arthrogram at 1 year postoperatively. The Institutional Review Board of Ewha Womans University approved this study (no. EUMC 2017-05-058). RESULTS: A total of 67 patients were enrolled: 33 underwent surgery with a 1.3-mm (single-loaded) or 1.8-mm (double-loaded) all-suture anchor (group A), and 34 underwent surgery with a 3.0-mm biodegradable anchor (10.8 mm in length, 30% 1,2,3-trichloropropane/70% poly-lactide-co-glycolic acid) (group B). There were no significant differences in clinical outcomes between groups A and B in the American Shoulder and Elbow Surgeons score (preoperatively, 51.2 ± 13.7 vs 47.7 ± 12.2; 2 years postoperatively, 88.5 ± 12.3 vs 89.7 ± 10.9; P = .667) and Rowe score (preoperatively, 41.4 ± 10.5 vs 41.3 ± 9.4; 2 years postoperatively, 87.9 ± 14.9 vs 88.5 ± 14.6; P = .857). Postoperative redislocation (6.1% vs 5.9%, P = .682) and subjective instability rate (12.2% vs 17.7%, P = .386) of both groups showed no significant difference. Average tunnel diameter increment was significantly greater with the 1.8-mm all-suture anchor (2.8 ± 0.9 mm) than the 1.3-mm all-suture anchor (1.2 ± 0.8 mm) and 3.0-mm biodegradable anchor (0.8 ± 1.2 mm) (P < .001). CONCLUSIONS: Arthroscopic Bankart repair with the all-suture anchor showed comparable clinical outcomes and postoperative stability as the conventional biodegradable suture anchor at 2 years after surgery. Tunnel diameter increment of the all-suture anchor was significantly greater than that of the biodegradable suture anchor at the 1-year computed tomography analysis. Although tunnel diameter increment was greater with the all-suture anchor, it did not influence the clinical outcomes. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Perianchor Cyst Formation After Arthroscopic Rotator Cuff Repair Using All-Suture-Type, Bioabsorbable-Type, and PEEK-Type Anchors.

PURPOSE: This study aimed to identify the difference in postoperative perianchor bone reactions in different groups of patients who underwent rotator cuff tear repairs with all-suture-, bioabsorbable screw-, and PEEK (polyether ether ketone)-type suture anchors. Furthermore, the rate of rotator cuff retear and its association with perianchor bone reactions based on the different anchors used were investigated. Moreover, their impact on the clinical outcome of patients was examined. METHODS: The study included 213 patients who underwent arthroscopic single-row repair and were divided into 3 groups according to the suture anchor used: all-suture (n = 137), biodegradable (n = 36), and PEEK (n = 40) anchor groups. The clinical outcomes and magnetic resonance imaging findings were evaluated at a mean follow-up of 9.6 months. The perianchor bone reaction at the anchor site was categorized according to grades. Patients were classified based on repair integrity into the healed and retear groups with Sugaya type I to III and Sugaya type IV to V, respectively. RESULTS: No statistically significant differences in Constant scores and retear rates were observed between the groups (P = .934 and P = .548, respectively). Magnetic resonance imaging showed that the total number of perianchor cysts formed postoperatively was 23 (10.8% [23 of 213 patients]). Moreover, the proportions of perianchor cysts were 8.8%, 16.7%, and 12.5% in the all-suture-type, bioabsorbable-, and PEEK-type anchor groups, respectively (P = .485). In the retear group, the incidence rate was significantly increased with higher grades of perianchor bone reaction (P = .001). The tear size and perianchor bone reaction were found to be independent factors that affected the incidence of retear. CONCLUSIONS: Perianchor cyst formation was observed in 10.8% of cases after the use of suture anchors for arthroscopic rotator cuff repair. No significant differences were observed among all-suture-type, bioabsorbable-type, and PEEK-type anchors in terms of visual analog scale and Constant scores, retear rates, and perianchor bone reactions. However, the retear rate was associated with a greater perianchor cystic reaction and larger tear size. LEVEL OF EVIDENCE: Level III, retrospective comparative trial.