Glenoid Anchor Research Articles

Arthroscopic Rotator Cuff Repair With Superior Capsule Reconstruction for Irreparable Supraspinatus Tears

Background: Irreparable rotator cuff tears represent approximately 12% of all presenting cuff tears, and multiple surgical techniques have been described for treatment, including allograft/bridge augmentation, debridement, partial repair, subacromial balloon, tendon transfer, and superior capsule reconstruction (SCR). SCR has demonstrated durable improvement in range of motion (ROM) and outcome scores at 2 and 5 years. Indications: Surgical indications for SCR include an irreparable tear of the supraspinatus and/or infraspinatus with a preserved or reparable subscapularis and preserved glenohumeral joint cartilage. Technique Description: Diagnostic arthroscopy is performed to identify and characterize the rotator cuff tear. Thorough debridement of the greater tuberosity is performed. Two all-suture FiberTak anchors are placed in the superior aspect of the glenoid. Two 2.6-mm FiberTak suture anchors are placed in the humeral head at the chondral margin. After measuring, the dermal allograft is cut to size with 15-mm overhang left on the far lateral edge. A 12-mm passport cannula is inserted laterally and the sutures from the glenoid and humeral head anchors are brought out through the cannula maintaining their position and orientation. The sutures are passed through the graft outside the cannula. The graft is introduced into the shoulder via the passport cannula with a back grasper. A cannula-in-cannula technique is used to tie the glenoid anchors first and then the medial row anchors. Two lateral row swivel lock anchors are used to complete a standard double row repair. Margin convergence is performed between the dermal allograft and remaining rotator cuff anterior and posterior. Postoperatively, patients are kept in a sling for 6 weeks, with no shoulder ROM. From weeks 6 to 12, patients discontinue sling and begin passive progression to active ROM. Strengthening is initiated at 12 weeks, and return-to-sport or work is at approximately 6 months. Results: Irreparable rotator cuff tears treated with arthroscopic rotator cuff repair and SCR show durable improvement in patient-reported outcomes at 2 and 5 years. Re-tear rates did not differ between athletes and non-athletes. Discussion/Conclusion: Arthroscopic rotator cuff repair with SCR is a durable and reliable surgical option for patients presenting with preserved glenohumeral joint and irreparable supraspinatus and/or infraspinatus tear. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

A biomechanical study to optimize superior capsular reconstruction operative technique

The goals of this study were to optimize superior capsular reconstruction by assessing the relative fixation strength of 4 suture anchors; evaluating 3 glenoid neck locations for fixation strength and bone mineral density (BMD); determining if there is a correlation between BMD and fixation strength; and determining which portal sites have optimal access to the posterosuperior and anterosuperior glenoid neck for anchor placement. Twenty cadaveric specimens were randomized into 4 groups: all-suture anchor (FiberTak), conventional 3.0-mm knotless suture anchor (SutureTak), 3.9-mm knotless PEEK (polyetheretherketone) Corkscrew anchor, and 4.5-mm Bio-Corkscrew anchor. Each specimen was prepared with 3 anchors into the glenoid: an anterosuperior anchor, superior anchor, and posterosuperior anchor. All anchors were inserted into the superior glenoid neck 5 mm from the glenoid rim. A materials testing system performed cyclic testing (250 cycles) followed by load-to-failure testing at 12.5 mm/s. Cyclic elongation, first cycle excursion, maximum load, and stiffness were recorded. Using custom software, BMD was calculated at each anchor location. This software was also used to assess access to the posterosuperior and anterosuperior glenoid neck from standard arthroscopic portal positions. There was no significant difference in cyclic elongation (P=.546), first cycle excursion (P=.476), maximum load (P=.817), or stiffness (P=.309) among glenoid anchor positions. Cyclic elongation was significantly longer in the PEEK Corkscrew group relative to the other implants (P≤.002). First cycle excursion was significantly greater in the FiberTak group relative to all other implants (P≤.008). For load-to-failure testing, the Bio-Corkscrew group achieved the highest maximum load (P≤.001). No other differences in cyclic or failure testing were observed between the groups. No differences in stiffness testing were observed (P=.133). The superior glenoid rim had the greatest BMD (P=.003), but there was no correlation between BMD and cyclic/load outcomes. The posterior portal (80% of specimens) and the anterior portal (60% of specimens) demonstrated the best access to the posterosuperior and anterosuperior glenoid neck, respectively. The 4.5-mm Bio-Corkscrew anchor provided the most robust fixation to the glenoid during superior capsular reconstruction as it demonstrated the strongest maximum load, had minimal elongation, had minimal first cycle excursion, and did not fail during cyclic testing. The superior glenoid neck had the highest BMD; however, there was no correlation between BMD or glenoid anchor location and biomechanical outcomes. The posterior portal and anterior portal provided optimal access to the posterosuperior glenoid neck and anterosuperior glenoid neck, respectively.

Arthroscopic Repair of a Type VIII Superior Labrum Anterior Posterior Tear

Background: Type VIII superior labrum anterior posterior (SLAP) tears are described as SLAP type II tears with posterior extension to the posterior inferior glenohumeral ligament. These tears are a common source of pain, instability, and decreased function in active individuals, particularly overhead or throwing athletes. Indications: Type VIII SLAP tears can cause pain and loss of sports performance, especially in a throwing athlete. This patient is a quarterback and pitcher who had magnetic resonance imaging and arthroscopic evidence of a type VIII SLAP tear with pain and inability to throw at his preinjury level. Technique Description: In the lateral decubitus position, a standard posterior portal is established along with anterior and accessory lateral portals. A type VIII SLAP tear is identified and the arm is taken out of balanced suspension traction and placed in abduction and external rotation which shows displacement of the posterior labrum and peelback of the superior labrum indicating pathologic labral instability. The labrum is then elevated and glenoid prepared to achieve healthy bleeding bone. Tape sutures are then passed around the labrum and placed into a glenoid anchor starting superiorly and continuing the repair posteroinferiorly. Three anchors were placed in the superior labrum using a percutaneous technique, with 2 more placed from the posterior portal to complete the 5-anchor repair. The posterior portal is then closed with a single monofilament suture to prevent a potential stress riser in the capsule. Results: The literature suggests that athletes with type VIII SLAP tears can expect improved functional outcomes and high return to play rates (>90%); however, only 50% to 70% of throwing athletes return to the same level of play. Discussion/Conclusion: Type VIII SLAP tears are an important cause of shoulder pain and dysfunction, particularly in overhead athletes. Arthroscopic repair of type VIII SLAP tears can improve functional outcomes and ability to return to sport; however, throwing athletes experience lower rates of return to previous level. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Arthroscopic Superior Capsular Reconstruction

Background: Limited options exist for young patients with massive, irreparable rotator cuff tears. While several treatment options exist, superior capsular reconstruction (SCR) was developed to restore glenohumeral joint stability by preventing superior humeral head migration during glenohumeral motion. Indications: Arthroscopic SCR is indicated in young patients with a massive, irreparable rotator cuff tear. Patients require a functioning deltoid muscle with minimal to no glenohumeral joint arthritis. In addition, patients should have Hamada grade 2 or less and should have an intact or repairable subscapularis tendon. Technique Description: The patient is positioned in the beach chair position. Standard anterior, posterior, and mid-lateral portals are established. An accessory posterior-superior lateral portal is used for visualization. Three 3.0 mm knotless anchors are placed in the glenoid through lateral percutaneous incisions. Two 4.75 mm anchors are placed adjacent to the humeral articular cartilage for medial row fixation. The graft dimensions are measured using the distance between the anchors. The graft is prepared using a gown card as a template with 5 mm added to the medial, posterior, and anterior graft dimensions, and 10 mm added to the lateral dimension. Sutures are passed through the graft in an inverted horizontal mattress for the glenoid anchors to diminish friction and allow appropriate suture passage through the knotless mechanism of the anchor. The graft is then shuttled into the joint through a lateral PassPort button cannula. Two lateral row anchors are used to secure the lateral graft on the humerus. Native rotator cuff tissue is repaired to the graft using sutures from the medial row anchors as well as free SutureTape. Results: Outcomes following SCR have demonstrated improvements in clinical outcomes and shoulder range of motion. Similar outcomes have been identified between the use of allograft and autograft. Patients generally are able to return to light recreational activities and work. Discussion/Conclusion: Arthroscopic SCR yields favorable results in the setting of a massive, irreparable rotator cuff tear. Meticulous surgical technique is needed to avoid intraoperative surgical complications. The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Biomechanical Comparison of Synthetic Polytetrafluoroethylene (PTFE) vs Human Dermal Allograft (HDA), 2 vs 3 Glenoid Anchors, and Suture vs Minitape in Superior Capsule Reconstruction.

Background: Superior capsule reconstruction (SCR) is an option for the treatment of massive, irreparable rotator cuff tears. However, which materials yield the strongest constructs remains undetermined. Purposes: We sought to investigate whether SCR with polytetrafluoroethylene (PTFE) or human dermal allograft (HDA), 2 or 3 glenoid anchors, and suture or minitape resulted in better failure load properties at the patch-glenoid interface. Methods: We conducted a biomechanical study in 30 glenoid-sided SCR repairs in Sawbones models divided into 5 groups. Each was pulled to failure to assess mode of failure, peak load (N), stiffness (N/mm), yield load (N), peak energy (N m), and ultimate energy (N m). The 5 groups were as follows: group 1-PTFE, 2 anchors, and suture; group 2-PTFE, 2 anchors, and minitape; group 3-HDA, 2 anchors, and suture; group 4-HDA, 2 anchors, and minitape; group 5-PTFE, 3 anchors, and minitape. Results: Repairs failed by button-holing of suture/minitape. Group 5 had greater peak load, stiffness, yield load, and peak energy (384 ± 62 N; 24 ± 3 N/mm; 343 ± 42 N; 4 ± 2 N m) than group 3 (226 ± 67 N; 16 ± 4 N/mm; 194 ± 74 N; 2 ± 1 N m) or group 4 (274 ± 62 N; 17 ± 4 N/mm; 244 ± 50 N; 2 ± 1 N m) and greater ultimate energy (8 ± 3 N m) than all other groups. Conclusions: This biomechanical study of SCR repairs in Sawbones models found that yield load was greater in PTFE than HDA, 3 anchors were better than 2, and minitape was no better than suture.

On-the-Edge Anchor Placement May Be Protective Against Glenoid Rim Erosion After Arthroscopic Bankart Repair Compared to On-the-Face Anchor Placement

This retrospective study aimed to compare the effects of 2 different anchoring placements on glenoid rim erosion after arthroscopic Bankart repair (ABR). Shoulders that underwent ABR from January 2013 to July 2020 were divided into 2 groups according to anchor placement (on-the-face, group F; on-the-edge, group E). We retrospectively calculated the percent change of glenoid width (Δ) on the first postoperative computed tomography scan (CT; performed within 6 months) and second postoperative CT (performed at 6 to 12 months) relative to the width on the preoperative CT and compared percent changes between the 2 groups. Also, we investigated the influence of preoperative glenoid structures (normal, erosion, bony Bankart) and the postoperative recurrence rate. We examined 225 shoulders in 214 patients (group F, n= 151; group E, n= 74). At first CT, anchoring placement was significantly associated with postoperative decrease of glenoid width (group F,-7.6% ± 7.9%; group E,-0.1% ± 9.7%; P < .0001). The difference between groups F and E was significant in shoulders with a preoperative glenoid defect (bony Bankart,-6.6%± 8.8% vs 2.5% ± 11.2%, respectively; P < .0001; erosion,-6.6% ± 6.2% vs-2.6% ± 5.3%, respectively; P= .03). In112 shoulders, CT was performed twice; Δ was-6.9% ± 7.3% in group F (n= 64) and-1.7%±10.1% in group E (n= 48; P= .005) at the first CT and-3.2% ± 10.0% and 1.0% ± 10.6% (P= .10), respectively, at the second CT, indicating recovery of glenoid width in both groups. The postoperative recurrence rate in patients with at least 2 years' follow-up was 14.7% in group F and 14.6% in group E. In the early stage after ABR, on-the-edge glenoid anchor placement was associated with less glenoid rim erosion than on-the-face anchor placement. Level III, retrospective comparative trial.

Surgical Technique for Superior Capsule Reconstruction With 6-mm Acellular Dermal Allograft and Knotless Glenoid Anchors

Superior capsule reconstruction (SCR) creates a humeral head depressor in the setting of a massive, irreparable rotator cuff tear. Recently, a 6-mm-thick acellular dermal allograft (ACD) has been shown to be noninferior to the standard fascia lata autograft in recreating native shoulder biomechanics. This paper outlines a reproducible means by which to perform an arthroscopic SCR using a 6-mm ACD. A standard diagnostic arthroscopy first assesses the integrity of the subscapularis and infraspinatus tendons. The glenoid anchors are then placed. Accessory anterior and posterolateral portals are made as well as a lateral portal by which to shuttle the graft. Suture management is paramount. Ideally allograft preparation occurs on the back table simultaneously to maintain efficiency. Suture passage through premade holes in the graft, and when the sutures have passed through and been tensioned, the graft is shuttled into place and tied down with medial and lateral row anchors in SpeedBridge fashion. The thickness of ACD has been shown to influence the ability of the reconstructed superior capsule to perform its role as a humeral head depressor. This technique describes the use of a 6-mm-thick ACD to perform an arthroscopic SCR that minimizes both donor-site morbidity and operative time.

Perceived vs. true glenoid anchor placement: a cadaveric comparison of the beach chair and lateral position.

PurposeTo explore whether patient position influences a surgeon’s ability to accurately judge anchor position on the glenoid.Materials and MethodsTwo anchors were inserted into the glenoid of 8 shoulders. Arthroscopic videos were taken from 3 views (posterior beach chair [pBC], posterior lateral decubitus [pLD], and anterosuperolateral decubitus [asLD]). The shoulders were disarticulated to identify “true” anchor position. Seventeen shoulder surgeons reviewed the videos and indicated anchor positions using the “clock face” method. Accuracy was measured within tolerances, ranging from zero (exact), 0.5 (half-hour), 1.0, and 1.5 hours of “true” position. Intra- and inter-rater agreement was calculated. Post hoc analyses explored for bias dependent on surgical side.ResultsThe overall accuracy was 34.0%. At tolerances of 0.5, 1.0, and 1.5 hours, accuracy increased to 82.4%, 95.4%, and 98.0%. With a 30° scope, identification of exact position was more accurate in pBC than pLD (odds ratio [OR] = 1.397; P = .029) but not asLD (OR =1.341; P = .197). At a tolerance of 0.5 hour, the 30° scope was more accurate in pBC than both pLD (OR = 1.444; P = .011) and asLD (OR = 1.728; P = .009). In left shoulders, anchors were perceived as more inferior than true position in asLD and pLD. In right shoulders, anchors were perceived as more superior than true position from pBC and pLD. Inter- and intrarater agreement were highest in pBC with a 30° scope (30° scope weighted kappa = 0.783 and 70° scope weighted kappa = 0.853, respectively).ConclusionJudgment of anchor position on video is most accurate in a pBC view. Inter- and intrarater reliability were also highest from a pBC view.

Glenoid Reaction to Biocomposite and PEEK Suture Anchors Following Arthroscopic Labral Repairs

Objectives:Biocomposite and all-suture suture anchors have been shown to cause reactive changes in the humerus and glenoid when used for arthroscopic rotator cuff and glenoid labrum repairs. The purpose of this study was to quantify glenoid anchor widening using biocomposite or PEEK suture anchors for arthroscopic shoulder stabilization. Our hypothesis was that biocomposite and PEEK anchors would lead to significant reactive changes in the glenoid as evidenced by a difference in postoperative tunnel size compared to suture anchor diameter.Methods:We searched the Military Data Repository for all patients with a history of a glenoid labrum repair who underwent a postoperative CT scan of the affected shoulder in our hospital market region. CT scans were measured using organic IMPAX tools to calculate the width and length of bone tunnels as described by Tompane et al. Bone mineral density was calculated by measuring the average Hounsfield Units through four axial segments of the glenoid neck in a best fit circle of cancellous bone. Tunnel widening was defined as an increase in width greater than 0.1mm compared to the drill size for each implant. Measurements were made by two independent observers blinded to other patient factors. Patient charts were also reviewed to obtain anchor data, injury, and surgical variables. Univariate analysis was performed to compare differences between tunnel widths and anchor sizesResults:We analyzed 146 bone tunnels in 37 shoulders that met inclusion criteria. The mean age was 23 (18-45), with 126 male and 20 females. The average time to CT scan from labrum repair was 782 days (159-2210). The majority of CT scans (33) were obtained after recurrent instability events, 2 were obtained for preoperative planning prior to shoulder arthroplasty, and 2 were obtained to evaluate the glenoid prior to military commissioning. The average number of anchors used per shoulder was 5. There were 17 PEEK and 129 biocomposite anchors included. There were 113 Arthrex, 28 Mitek, and 3 Zimmer Biomet anchors included in the data. There were 81 anchors in the anterior inferior quadrant, 21 anterior superior, 37 posterior inferior, and 6 in the posterior superior quadrant of the glenoid. The mean difference between tunnel and anchor width was 0.002mm across the data set. Fifty-five biocomposite anchors (43.6%) showed an increased tunnel diameter of greater than 0.1mm compared to anchor size. 7 PEEK anchors (41%) demonstrated an increased tunnel diameter greater than 0.1mm. Additionally, 14 tunnels demonstrated an increased width greater than 1mm compared to anchor size and all were biocomposite anchors. There was no difference in tunnel widening between biocomposite and PEEK anchors (p=0.34). The average change in width across widened tunnels was 0.07mm. The average change in tunnel size across all anchors was 0.02mm. On univariate analysis, bone mineral density, anchor size, anchor position, time to CT scan, composition, and age were not shown to have a statistically significant correlation.Conclusion:At short term 2 year follow-up there was no difference in tunnel widening between PEEK and biocomposite suture anchors. Although the majority of bone tunnels did not demonstrate significant widening compared to the implant size, 43.6% of biocomposite and 41% PEEK anchors generated reactive changes greater than 0.1mm. There were no clear trends in anchor type or location that clearly contributed to tunnel widening.

What Are the Effects of Remplissage on 6-Month Strength and Range of Motion After Arthroscopic Bankart Repair? A Multicenter CohortStudy.

Background:Patients who have undergone shoulder instability surgery are often allowed to return to sports, work, and high-level activity based largely on a time-based criterion of 6 months postoperatively. However, some believe that advancing activity after surgery should be dependent on the return of strength and range of motion (ROM).Hypothesis:There will be a significant loss of strength or ROM at 6 months after arthroscopic Bankart repair with remplissage compared with Bankart repair alone.Study Design:Cohort study; Level of evidence, 2.Methods:A total of 38 patients in a prospective multicenter study underwent arthroscopic Bankart repair with remplissage (33 males, 5 females; mean age, 27.0 ± 10.2 years; 82% with ≥2 dislocation events in the past year). Strength and ROM were assessed preoperatively and at 6 months after surgery. Results were compared with 104 matched patients who had undergone Bankart repair without remplissage, although all had radiographic evidence of a Hill-Sachs defect.Results:At 6 months, there were no patients in the remplissage group with anterior apprehension on physical examination. However, 26% had a ≥20° external rotation (ER) deficit with the elbow at the side, 42% had a ≥20° ER deficit with the elbow at 90° of abduction, and 5% had persistent weakness. Compared with matched patients who underwent only arthroscopic Bankart repair, the remplissage group had greater humeral bone loss and had a greater likelihood of a ≥20° ER deficit with the elbow at 90° of abduction (P = .004). Risk factors for a ≥20° ER deficit with the elbow at 90° of abduction were preoperative stiffness in the same plane (P = .02), while risk factors for a ≥20° ER deficit with the elbow at the side were increased number of inferior quadrant glenoid anchors (P = .003), increased patient age (P = .02), and preoperative side-to-side deficits in ER (P = .04). The only risk factor for postoperative ER weakness was preoperative ER weakness (P = .04), with no association with remplissage (P = .26).Conclusion:Arthroscopic Bankart repair with remplissage did not result in significant strength deficits but increased the risk of ER stiffness in abduction compared with Bankart repair without remplissage at short-term follow-up.

Comparison of Knotless Versus Traditional Glenoid Anchors in Early Outcomes Following Arthroscopic Shoulder Stabilization

Objectives: To compare knotless versus traditional glenoid anchors as well as use of all-suture versus non-all suture anchor material in early outcomes after arthroscopic shoulder stabilization. We hypothesize there is no difference in outcomes between anchor type or material. Methods: Patients who were prospectively enrolled in the Multicenter Orthopaedic Outcomes Network (MOON) Shoulder Group instability database completed a series of patient reported outcomes (PROs) pre and post-operatively at 2 years. At the time of surgery, physicians documented technique utilized and materials employed. The incidence of subsequent shoulder surgeries, re-dislocations or subluxations, and return to sport (RTS) were obtained. Patients were stratified by anchor type (knotless [KL] versus knotted [KT]) and then by anchor material (all-suture [AS] versus non-all suture [NS]). Bivariate analyses were performed to compare outcomes between groups, including the Wilcoxon signed-rank test and chi-square test. Results: A total of 447 patients who underwent primary arthroscopic shoulder stabilization were evaluated, with 112 patients in the KL group (90.2% male) and 335 in the KT group (82.4% male; p &gt; .05). Then there were 70 patients in the AS group (74.3% male) and 377 in the NS group (86.2% male; p = .01). The KT group (24.6 ± 8.9 years) was significantly older than the KL group (21.3 ±7.8 years; p = .0003) while the AS group (26.8 ±9.1 years) was significantly older than the NS group (23.2 ±8.6 years; p = .003). Significantly more patients in the KL group (87.5%) underwent surgery in the beach chair (BC) position than the KT group (45.4%; p &lt; .0001) and significantly more patients in the NS group (59.9%) underwent surgery in the BC position than the AS group (34.3%; p &lt; .0001). The primary direction of instability was anterior, with 78.6% in the KL group, 71.3% in the KT group, 82.9% in the AS group and 71.4% in the NS group. The number of contact athletes was similar in each group, with 75.0% in the KL group, 66.0% in the KT group, 70.0% in the AS group, and 67.9% in the NS group. Significantly more anchors were used in the KL group (4.2 ± 1.6) compared to the KT group (3.9 ± 1.8; p = .003) and significantly more anchors were used in the AS group (5.3 ± 2.4) compared to the NS group (3.7 ± 1.4; p &lt; .0001). Significantly more patients had a redislocation in the KL group (11.6%) compared to the KT group (5.7%; p = .03), and significantly more patients had a redislocation in the NS group (8.2%) compared to the AS group (1.4%; p = .04). There were no significant differences in improvement of any PROs, incidence of RTS, subsequent shoulder surgeries or subluxations between anchor type or material groups. Conclusion: Compared to traditional knotted glenoid anchors, patients undergoing arthroscopic shoulder stabilization with knotless anchors can expect to experience similar clinical outcomes. However, use of knotless anchors may be a significant risk factor for subsequent dislocation 2 years after arthroscopic shoulder stabilization surgery, which may be related to patients’ age. Moreover, use of all-suture based anchors may be associated with lower rates of subsequent dislocation which may be attributed to the size of their footprint and the apparent inclination of surgeons using these to utilize more anchors per labral repair, thus increasing points of labral fixation. Continued investigation of potential confounding variables is necessary to identify the direct effect of anchor type and material on patient outcomes.

Radiographic comparison between the portals in the positioning of glenoid anchors in the surgical treatment of shoulder instability

Radiographic comparison between the portals in the positioning of glenoid anchors in the surgical treatment of shoulder instability

Feasibility and safety of arthroscopic medial glenohumeral ligament and subscapularis tendon repair with knotless anchors: A cadaveric study in dogs.

To test the feasibility and safety of an arthroscopic imbrication of the medial glenohumeral ligament (MGHL) and the subscapularis tendon with knotless anchors in dogs. Cadaveric study. Ten limbs. Cranial and caudal arms of the MGHL were imbricated with a 2.9- or a 2.4-mm knotless anchor. A horizontal mattress suture secured with a 3.5-mm knotless anchor was used to imbricate the subscapularis tendon. Computed tomography measurements included (1) the bone stock around the anchors, (2) the angle between the anchor and the joint surface (insertion angle), and (3) the angle formed by lines tangent to the cortices of the bones (safety angle). Limbs were dissected to assess the position of anchors. Safety and insertion angles and bone stock were compared among anchors with a Kruskal-Wallis test (P < .05). Surgical repairs were achieved in all limbs, with only 2 of 30 anchors incorrectly placed, both in the glenoid. The safety angle of the humeral anchor (HA; median, 89°) was greater than that of the cranial glenoid anchor (CrGA; P = .0017) and the caudal glenoid anchor (CdGA; P < .001). The insertion angle of the HA (median, 68°) was also greater than that of the other anchors (P < .001 and P = .001). The insertion angle of the CrGA (median, 26°) was greater (P = .0191) than that of the CdGA (median, 7°). All anchors were inserted at the MGHL and subscapularis footprint. Arthroscopic imbrication of MGHL and subscapularis tendon was feasible. HA were safer to place than glenoid anchors. The results of this feasibility study justify further evaluation of the indications and outcomes of this technique in dogs with shoulder instability.

Fresh Osteochondral Allograft Transplantation for Focal Chondral Defect of the Humerus Associated With Anchor Arthropathy and Failed SLAP Repair

Isolated, full-thickness articular cartilage lesions of the glenohumeral joint can cause pain, mechanical symptoms, and impaired function. Reports on operative management of these injuries with arthroscopic techniques, such as marrow stimulation, have shown improvement in patient symptoms. In cases where the subchondral bone is involved, osteochondral allograft (OCA) transplantation has shown positive results for contained, focal cartilage defects. The technique for OCA transplantation to treat Hill-Sachs lesions has been reported in detail, and there are multiple case series reporting on the outcomes of OCA used for this purpose. This Technical Note shows the application of OCA to treat a case of anchor arthropathy where a glenoid anchor placed during arthroscopic stabilization causes iatrogenic damage to the humeral head. This type of injury can result in cartilage lesions in uncommon locations, such as on the posterior humeral head. In this description, the technical pearls and pitfalls of managing difficult-to-access posterior humeral head lesions are presented along with the senior authors' general technique for OCA to treat focal lesions of the humeral head cartilage.

Biomechanical Comparison of a First- and a Second-Generation All-Soft Suture Glenoid Anchor.

Background:All–soft tissue suture anchors provide advantages of decreased removal of bone and decreased glenoid volume occupied compared with traditional tap or screw-in suture anchors. Previous published data have led to biomechanical concerns with the use of first-generation all-soft suture anchors.Purpose/Hypothesis:The purpose of this study was to evaluate the load to 2-mm displacement and ultimate load to failure of a second-generation all-soft suture anchor, compared with a first-generation anchor and a traditional PEEK (polyether ether ketone) anchor. The null hypothesis was that the newer second-generation anchor will demonstrate no difference in loads to 2-mm displacement after cycling compared with first-generation all-soft suture anchors.Study Design:Controlled laboratory study.Methods:Twenty human cadaveric glenoids were utilized to create 97 total suture anchor sites, and 1 of 3 anchors were randomized and placed into each site: (1) first-generation all-soft suture anchor (Juggerknot; Biomet), (2) second-generation all-soft suture anchor (Suturefix; Smith & Nephew), and (3) a control PEEK anchor (Bioraptor; Smith & Nephew). After initial cyclic loading, load to 2 mm of displacement and ultimate load to failure were measured for each anchor.Results:After cyclic loading, the load to 2-mm displacement was significantly less in first-generation anchors compared with controls (P < .01). However, the load to 2-mm displacement was significantly greater in second-generation anchors compared with controls (P < .01). There was no difference in ultimate load to failure between the first- and second-generation all-soft suture anchors (P > .05).Conclusion:The newer generation all-soft suture anchors with a theoretically more rigid construct and deployment configuration demonstrate biomechanical characteristics (specifically, with load to 2-mm displacement after cyclic loading) that are improved over first-generation all-soft suture anchors and similar to a traditional solid tap-in anchor. The configuration of these newer generation all-soft suture anchors appears to mitigate the biomechanical concerns of decreased load to failure with first-generation all–soft tissue suture anchors.Clinical Relevance:The theoretical advantages of all-soft anchors may be particularly valuable in revision surgery or in cases where multiple anchors are being placed into a small anatomic area.

Adverse Local-Tissue Reactions in the Upper Extremity

In general, there are several types of adverse local-tissue reactions associated with orthopaedic biomaterials and devices, including infection, metallosis, particle-induced osteolysis, and an immune reaction associated with particles or ions. This month’s “Case Connections” spotlights 6 cases of adverse local-tissue reactions in the upper extremity, including (1) metallosis due to glenoid erosion secondary to a proximal humeral component’s contact with retained metal suture anchors (1 patient), (2) destructive glenoid osteolysis, anchor pull-out, and subsequent glenohumeral articular cartilage damage following the failure of bioabsorbable knotless suture anchors (4 patients), and (3) humeral fracture metallosis culminating in a nonunion following the placement of a titanium flexible humeral intramedullary nail (1 patient). In the April 12, 2017, edition of JBJS Case Connector, Mitchell et al. reported the case of a 52-year-old man who presented with bilateral shoulder dysfunction with limited range of motion and pain that restricted activities of daily living as well as recreational and job-related activities. Approximately 6 years previously, the patient had undergone bilateral open and arthroscopic stabilization procedures for glenohumeral instability; the most recent arthroscopic procedures utilized titanium glenoid suture anchors (GII Anchor; Mitek Sports Medicine). At the time of presentation, physical and radiographic findings were consistent with bilateral end-stage posttraumatic osteoarthritis. The patient was initially managed with 6 months of nonoperative treatment, without subjective or objective improvement. He subsequently underwent staged bilateral shoulder hemiarthroplasty with cobalt-chromium-alloy (Co-Cr-Mo) humeral resurfacing (HemiCAP; Arthrosurface). During both procedures, the metallic suture anchors were not visible and were left in place. The patient noted increasing pain and a grinding sensation in the right shoulder approximately 3.5 years after the first hemiarthroplasty. Radiographs demonstrated medial glenoid erosion without compromise of the anchors. The patient was offered a total shoulder arthroplasty (TSA), but he elected serial radiographic follow-up instead. Imaging continued to demonstrate progressive glenoid …

Quantitative and Computed Tomography Anatomic Analysis of Glenoid Fixation for Superior Capsule Reconstruction: A Cadaveric Study

To investigate glenoid fixation for superior capsule reconstruction (SCR) and evaluate anchor positions, intraosseous trajectories, and proximity to the suprascapular nerve (SSN) and glenoid fossa. The secondary purpose was to provide technical pearls and pitfalls for anchor insertion on the superior glenoid during SCR. Three beath pins were arthroscopically inserted into 12 (n= 12) nonpaired human cadaveric shoulders through Neviaser, anterior, and posterior portals to simulate anchor placement on the superior glenoid during SCR. Computed tomography scans were performed to evaluate anchor positioning and insertion trajectories. Specimens were then dissected to delineate the anatomic relations of the beath pins to the SSN and glenoid fossa. The superior glenoid anchor position was a mean 15.0 ± 4.0mm to the SSN and 6.5 ± 1.7mm to the glenoid fossa. The posterior glenoid anchor position was a mean 11.8 ± 2.1mm to the SSN and 2.9 ± 2.9mm to the glenoid fossa. On average, the superior pin was placed at 12:30 ± 0:30 (left-sided glenoid clock face) and inserted at 19° ± 9° with respect to the sagittal plane of the glenoid, the anterior pin was placed at 11:00 ± 0:30 and inserted 40° ± 17° off the glenoid, and the posterior pin was placed at 3:00 ± 1:00 and inserted at 52° ± 12° off the glenoid. The results of the present cadaveric study showed that glenoid fixation was safe with respect to the SSN and delineated technical guidelines and trajectories for inserting 3 anchors into the glenoid. This study shows that 3 anchors can be inserted into the glenoid without a risk of SSN damage and delineates technical guidelines for anchor insertion.

Trans-subscapularis Portal Versus Low-Anterior Portal for Low Anchor Placement on the Inferior Glenoid Fossa: A Cadaveric Shoulder Study With Computed Tomographic Analysis

The purpose of this study was to evaluate the accuracy of inserting a glenoid anchor at the 5:30 clockface position using a trans-subscapularis (TSS) portal versus a low anterior (LA) portal. Five surgeons (T.D., J.C., C.V., D.J.O-H., J.S.T.) placed a single anchor in 20 fresh-frozen cadaveric shoulders. In each of 2 shoulders, surgeons used an LA portal to insert the anchor, whereas in 2 shoulders a TSS portal was used. Surgeons were directed to place the anchor at the 5:30 position at an angle 45° to the glenoid surface (axial plane) and passing perpendicular to the glenoid rim in the coronal plane. Shoulders were then dissected and computed tomographic (CT) scans obtained. Anchor position relative to the clockface was documented by 2 blinded assessors, as was the angle of insertion in the axial and coronal planes. Statistical significance was calculated with a Student t test for paired samples (confidence interval [CI], 95%; significance, P < .05). The average deviation from the 5:30 position was 48 minutes (standard deviation [SD], 31 minutes) for the LA portal (average position, 4:42 o'clock) versus 28.5 minutes (SD, 19 minutes) for the TSS group (average position, 5:02 o'clock) (P= .15). The average angle of anchor insertion in the axial plane was 67.2° (SD, 19°) for the LA portal versus 62.8° (SD, 14°) for the TSS portal (P= .49), whereas the average angle of insertion in the coronal plane was 31.3° (SD, 14°) of inferior angulation in the LA group and 14.3° (SD, 8°) of inferior angulation in the TSS group (P= .009). Of the anchors inserted, 9 of 20 (45%) showed evidence of far-cortical perforation. No difference in cortical perforation was seen between the 2 portals, with perforation more likely with anchors inserted greater than 45° in the axial plane (8 of 20) than with those inserted less than 45° (1 of 20) (P= .02). The use of a TSS portal improves the angle of approach to the inferior glenoid rim in comparison with an LA portal, reducing the acuity of the angle of insertion in the coronal plane. The TSS portal is an option for surgeons performing arthroscopic Bankart repair using anchors low on the glenoid rim.

The histologic and biomechanical response of two commercially available small glenoid anchors for use in labral repairs

This study examined histologic characteristics and biomechanical performance of 2 commercially available, small glenoid anchors. Adult research dogs (n = 6) were used for histologic analysis. Anchors were inserted into the lateral rim of the glenoid using the manufacturer's protocol. The dogs were humanely euthanatized 8 weeks after anchor implantation, and the glenoids were collected for histologic analysis. Bone socket width data were compared for statistically significant (P < .05) differences. In addition, 4 matched pairs (n = 8) of human cadaveric glenoids were instrumented with 1 BioComposite SutureTak (Arthrex, Naples, FL, USA) and 1 JuggerKnot (Biomet, Warsaw, IN, USA) suture anchor in the anterior-inferior quadrant. Anchor constructs were preloaded to 5 N, cycled from 5 to 25 N for 100 cycles, and then pulled to failure. All JuggerKnot anchor sites were cyst-like cavities with a rim of dense lamellar bone. All BioComposite SutureTak anchor sites contained intact anchors with close approximation of anastomosing trabeculae of lamellar bone. At 8 weeks after implantation, mean socket width of the JuggerKnot anchor sites was 6.3 ± 2.5 mm, which was significantly (P = .013) larger than the mean socket width of 2.7 ± 0.7 mm measured for the BioComposite SutureTak anchor sites. The JuggerKnot anchor demonstrated larger displacements during subfailure cyclic loading (2.9 ± 1.0 mm compared with 1.3 ± 0.4 mm) and load to failure tests (13.7 ± 6.6 mm compared with 3.2 ± 0.5 mm). Statistical differences (P < .01) existed in every category except ultimate load. Based on the biomechanical in human bone and histologic findings in canine subjects, the all-suture anchor may be at risk for clinical failure.

Maximum load to failure and tensile displacement of an all-suture glenoid anchor compared with a screw-in glenoid anchor

The purpose of this study was to evaluate the biomechanical behavior of an all-suture glenoid anchor in comparison with a more conventional screw-in glenoid anchor, with regard to maximum load to failure and tensile displacement. All mechanical testing was performed using an Instron ElectroPuls E1000 mechanical machine, with a 10 N pre-load and displacement rate of 10 mm/min. Force-displacement curves were generated, with calculation of maximum load, maximum displacement, displacement at 50 N and stiffness. Pretesting of handset Y-Knots in bone analog models revealed low force displacement below 60 N of force. Subsequently, three groups of anchors were tested for pull out strength in bovine bone and cadaver glenoid bone: a bioabsorbable screw-in anchor (Bio Mini-Revo, ConMed Linvatec), a handset all-suture anchor (Y-Knot, ConMed Linvatec) and a 60 N pre-tensioned all-suture anchor (Y-Knot). A total of 8 anchors from each group was tested in proximal tibia of bovine bone and human glenoids (age range 50-90). In bovine bone, the Bio Mini-Revo displayed greater maximum load to failure (206 ± 77 N) than both the handset (140 ± 51 N; P = 0.01) and the pre-tensioned Y-Knot (135 ± 46 N; P = 0.001); no significant difference was seen between the three anchor groups in glenoid bone. Compared to the screw-in anchors, the handset all-suture anchor displayed inferior fixation, early displacement and greater laxity in the bovine bone and cadaveric bone (P < 0.05). Pre-tensioning the all-suture anchor to 60 N eliminated this behavior in all bone models. Handset Y-Knots display low force anchor displacement, which is likely due to slippage in the pilot hole. Pre-tensioning the Y-Knot to 60 N eliminates this behavior. I.