Cartilage injuries in the shoulder joint caused by migration of suture anchors or mini screw

Outcomes of Double-Row Rotator Cuff Repair Using a Novel All-Suture Soft Anchor Medial Row

Background

Few studies have examined the short-term clinical outcomes of rotator cuff repair (RCR) with all-suture anchors for medial row anchor fixation.

Purpose

To evaluate clinical outcomes of double-row suture bridge RCR using a novel all-suture medial row anchor.

Study Design

Case series; Level of evidence, 4.

Methods

We enrolled 179 patients before double-row suture bridge RCR (mean age at surgery, 60.0 years; 63% male patients) at a single institution. All patients underwent RCR with all-suture anchor fixation for the medial row and solid anchor fixation for the lateral row. Preoperative (baseline) and follow-up (minimum follow-up time of 2 years; mean, 2.5 years) clinical outcomes were compared using the American Shoulder and Elbow Surgeons (ASES) score and a 10-point numeric pain rating scale (NPRS). We calculated the proportions of patients meeting previously published Patient Acceptable Symptom State (PASS) thresholds for the ASES (≥78.0) and NPRS (≤1.7). We further compared baseline and follow-up outcome scores and the proportions of patients meeting PASS thresholds using paired t tests and McNemar tests, respectively, and calculated effect size to quantify the magnitude of change from baseline to follow-up.

Results

Values significantly improved from baseline to follow-up for ASES (from 45.3 ± 19.8 to 87.3 ± 17.1) and NPRS (from 5.2 ± 2.5 to 1.4 ± 2.1). The proportion of patients meeting PASS thresholds also significantly improved for the ASES (from 6% to 77%) and the NPRS (from 7% to 72%). The magnitude of baseline to follow-up change for all measures was large (all effect sizes ≥1.5).

Conclusion

Our study demonstrated excellent short-term clinical outcomes and substantial improvements for patients undergoing double-row suture bridge RCR with all-suture anchors for medial row fixation.

Biomechanical comparison of knotless vs. knotted suture anchors in the acetabular rim with respect to bone density

BACKGROUND

Acetabular labral tears are managed with suture anchors providing good clinical outcomes. Knotless anchors are easier to use and have a quicker insertion time compared to knotted anchors. The purpose of this study was to compare the biomechanical behavior of two different anchor designs (knotted vs. knotless) in ultimate load testing in correlation with bone density in the acetabular rim.

METHODS

Eighteen knotted Bio-FASTak and seventeen knotless PushLock anchors (both: Arthrex Inc., Naples, FL, USA) were inserted in the rims of two human acetabula, with known bone density distribution. The anchors were subjected to load-to-failure tests. Anchors were additionally tested in solid polyurethane foam with defined densities.

FINDINGS

The Bio-FASTak group showed higher survival rates at 1, 2, and 3 mm displacement and was able to withstand significantly higher loads at 3 mm displacement (p = 0.031). There was no statistically significant difference in stiffness (p = 0.087), yield- (p = 0.190), and ultimate load (p = 0.222) between the two groups. Only the PushLock group showed correlation between bone volume over total volume (BV/TV) and stiffness (R = 0.750, p = 0.086) and between BV/TV and yield load (R = 0.838, p = 0.037). Experiments on solid polyurethane foam confirmed the correlation between the mechanical properties and tissue density for the same anchor.

INTERPRETATION

PushLock shows similar biomechanical properties to the Bio-FASTak, but eliminates knot tying and potentially abrasive knots. In addition, biomechanical properties of the PushLock are governed by local bone density.

Arthroscopic glenoid labral lesion repair using all-suture anchor for traumatic anterior shoulder instability: short-term results

BACKGROUND

This study presents the preliminary clinical results of arthroscopic glenoid labral lesion repair using all-suture anchors in the treatment of recurrent traumatic anterior shoulder instability.

METHODS

Seventy patients who underwent arthroscopic shoulder stabilization for traumatic anterior shoulder instability were evaluated in this single center-based retrospective study. Patients with a glenoid defect greater than 20%, off-track engaging Hills-Sachs lesion, multidirectional instability, and generalized ligamentous laxity were excluded. The 62 included patients treated with arthroscopic glenoid labral lesion repair using all-suture anchors were evaluated. The Rowe and Constant scores were used to assess the results.

RESULTS

We evaluated 62 patients with a mean age of 26.7 ± 12 years. The mean Rowe and Constant scores were 35 ± 7.2 and 65 ± 6.3, respectively, preoperatively and increased to 93.6 ± 5.3 and 92 ± 4.3, respectively, postoperatively at the mean follow-up of 28.8 months (range, 24-48 months) (P < .001). The redislocation rate was 8.1%. Of the patients, 91.9% had good to excellent clinical scores. Younger age and contact sports were associated with a higher risk of recurrent dislocation (P = .012 and P = .041, respectively). The postoperative functional results were not significantly correlated with the findings concerning the number of dislocations, time until surgery, degree of anterior translation, and number of anchors.

CONCLUSION

The use of all-suture anchors for arthroscopic glenoid labral lesion repair for the treatment of recurrent traumatic anterior shoulder instability yields satisfactory clinical results and is a safe and effective option.

Imaging of Usual and Unusual Complication of Rotator Cuff Repair

Several complications may be encountered after rotator cuff (RC) repair. A thorough knowledge of surgical interventions, normal postoperative findings, and postoperative complications is crucial to provide a timely diagnosis, improving the clinical outcome of patients. Postoperative complications may involve RC, implanted device, osteochondral tissue, surgical-site infection, peripheral nerves, soft tissues, and vascular structures. In this review, we discuss the usual and unusual complications detectable after RC repair.

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.

Postoperative evaluation of drill holes for arthroscopic Bankart repair with suture anchors by the use of computed tomography

BACKGROUND

Here we investigated the angle and placement of bone holes for suture anchors using postoperative computed-tomography scapula scans.

METHODS

The study group comprised 20 shoulders from 20 consecutive patients (13 males and seven females; mean age 23.4 years) who underwent arthroscopic Bankart repair. All anchors were inserted through the anterior portal after establishing a bone hole at the edge of the glenoid articular surface using a drill. Computed tomography images of the scapula were taken 1 month postoperatively and used to create three-dimensional scapula models with Mimics and Magics software. Bone holes in the anterior-inferior (3:00-6:00) position were assigned either to the non-perforated group if they were positioned entirely inside the glenoid bone or to the perforated group if the far cortex of the glenoid was penetrated by the drill. The angle between the glenoid articular surface and the bone hole was measured in the oblique coronal and transverse plane views. The length of the bone hole was also assessed.

RESULTS

Of the 85 bone holes investigated, 42 were in the 3:00-6:00 position. Perforation was detected in 16 of these 42 holes (38.2%). The angle in the oblique coronal plane view and the length of the bone hole were significantly larger in the non-perforated group than in the perforated group; however, the angle in the transverse plane view did not significantly differ between the two groups.

CONCLUSIONS

Before inserting an implant in the anterior-inferior area, the angle between the drill guide and the glenoid surface in the oblique coronal plane view should be carefully checked to ensure that the length of the hole inside the glenoid bone is adequate.

Biomechanical performance of traditional arthroscopic knots versus slippage-proof knots

PURPOSE

To compare the biomechanical, time, and profile characteristics of a new sliding locking knot termed the slippage-proof knot (SPK) and a modified slippage-proof knot (MSPK) with those of traditional arthroscopic knots.

METHODS

We evaluated the Samsung Medical Center (SMC) knot, Revo knot, SPK, and MSPK (an SPK with a single added half-hitch) tied with high-strength suture, with 11 trials of each cycled 1,000 times between 10 and 45 N and then loaded to failure. Total displacement during cyclical testing, maximal load to failure, and mode of failure were recorded for each knot. We also measured the dimensions of the knots and the time required to tie each knot.

RESULTS

On load-to-failure testing, no difference in strength was found between the SMC and Revo knots (P = .082). The Revo knot and MSPK were also of equivalent strength (P = .183), and the SMC knot was 11% stronger than the MSPK (P = .017). All 3 of these knots were stronger than the SPK. On cyclical testing, the SMC knot, Revo knot, and MSPK allowed equivalent total displacement and allowed statistically less total displacement than the SPK. All SMC knots, Revo knots, and MSPKs failed by suture breakage, whereas the SPKs all slipped at failure. We found that the SPKs and MSPKs are tied more quickly than traditional knots. The SPK and MSPK dimensions are wider yet shorter than those of the other knots in the study.

CONCLUSIONS

Our results indicate that the MSPK has biomechanical properties comparable to the SMC and Revo knots despite only requiring 1 added half-hitch, whereas the SPK was found to be significantly inferior to the other knots tested. We found that the slippage-proof knots (SPK and MSPK) were tied more quickly and have shorter, wider profiles than traditional knots.

CLINICAL RELEVANCE

The MSPK has knot security comparable to the SMC and Revo knots while requiring only 1 added half-hitch, and it may be most beneficial in cases in which a large number of knots will be tied because the fewer required half-hitches reduces the surgical time without reducing its biomechanical properties.

Tissue anchor use in arthroscopic glenohumeral surgery

Arthroscopic surgery has become the mainstay of treatment of several common glenohumeral pathologies such as tears of the rotator cuff and labrum. Arthroscopic rotator cuff and labral repair provide outcomes comparable to those achieved with traditional open techniques, with the benefits of smaller incisions and less soft-tissue disruption. Development and improvement of tissue anchors and arthroscopic instrumentation has been integral to the increased popularity of arthroscopic glenohumeral repairs. Current anchors can be categorized by design and material composition. Awareness of the advantages and limitations of these implants may influence anchor selection.

Bone replacement of fast-absorbing biocomposite anchors in arthroscopic shoulder labral repairs

BACKGROUND

Newer generation biocomposite anchors are hypothesized to resorb more reliably and faster, while allowing for bone ingrowth and replacement.

PURPOSE

The purposes of this study were to (1) assess anchor resorption and bone ingrowth over time, (2) identify tunnel widening or potential reactions to the implants, (3) compare imaging findings for different sites of labral repair, and (4) determine patient subjective outcomes with the use of biocomposite anchors in glenoid labral repair.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

We enrolled 22 patients to participate in a 24-month outcomes study that included subjective and objective outcome assessments after glenoid labrum repair surgery. Magnetic resonance imaging (MRI) was performed at 6 and 12 months to identify any potential reactions to implants. Computed tomography (CT) scans were performed at 12 and 24 months to determine anchor resorption and bone ingrowth. Sixteen patients and 47 anchors were available for follow-up at 24 months. An independent, fellowship-trained musculoskeletal radiologist read the scans. Subjective outcome scores measured at 24 months postoperatively included Simple Shoulder Test, Tegner activity scale, American Shoulder and Elbow Surgeons (ASES), and University of California, Los Angeles (UCLA) shoulder scores.

RESULTS

No adverse events were reported with the use of biocomposite anchors at the end of the study period. At 12 and 24 months, respectively, CT scans demonstrated that an estimated 68% and 98% of combined anchor material had been absorbed, 56% and 78% of the anchor material had been replaced by soft tissue of variable density, and 9% and 20% of total anchor volume was replaced by bone. No obvious mechanical failure of the labral repairs was detected on nonarthrogram MRI. Three of the 47 anchors showed bone cyst formation. Tunnel widening (expansion beyond tunnel diameter of 3 mm; 2.9-mm drill hole utilized) was seen in 55% of the anchors but decreased between 12 and 24 months, consistent with bone replacement. Tunnel widening was seen more in anteroinferior and posterior glenoid anchor locations (84% and 57%, respectively) than in superior labral anchors (13%). Subjective outcome scores at 24 months for ASES and UCLA shoulder scores averaged 88 and 30, respectively. All but one patient were satisfied with their outcome at 24 months.

CONCLUSION

Our imaging evaluation indicates resorption of newer generation biocomposite anchors with progressive bone replacement at 12 and 24 months while maintaining acceptable subjective outcomes.

Chondrolysis of the glenohumeral joint after infusion of bupivacaine through an intra-articular pain pump catheter: a report of 18 cases

PURPOSE

To report on our experience of patients who received infusion of bupivacaine with epinephrine after arthroscopic glenoid labral repair surgery and in whom glenohumeral joint chondrolysis subsequently developed, as well as to determine the incidence of such chondrolysis in our surgeons' patient populations.

METHODS

A retrospective chart review of 18 patients diagnosed with chondrolysis was carried out. All patients were from 2 experienced orthopaedic surgeons' practices. Details of their clinical course were obtained and summarized. These data were compared with all other arthroscopies completed by the 2 surgeons to determine the incidence of chondrolysis.

RESULTS

All 18 patients diagnosed with glenohumeral joint chondrolysis received postoperative infusion of bupivacaine with epinephrine through an intra-articular pain pump catheter (IAPPC). None of the patients received thermal energy as part of their procedure. None of the patients had evidence of glenohumeral joint infection, although an extensive workup was frequently undertaken. Clinically, patients presented with a stiff, painful shoulder. Examination showed decreased range of motion of the affected shoulder. Radiographs and magnetic resonance imaging showed joint space narrowing, as well as subchondral sclerosis and cyst formation. Of the 18 patients, 14 have since undergone repeat arthroscopic procedures, and 5 have received a humeral head-resurfacing operation. Within the same time period, there were 113 arthroscopies, with 45 pain pumps used. Chondrolysis developed in 16 of 32 patients with high-flow IAPPCs and 2 of 12 patients with low-flow IAPPCs (1 patient's IAPPC flow rate was not documented).

CONCLUSIONS

Although we cannot establish a causal link, the development of glenohumeral chondrolysis may be related to the intra-articular infusion of bupivacaine with epinephrine postoperatively. We thus caution against the use of IAPPCs.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Biomechanical comparison of screw-in suture anchor-suture combinations used for Bankart repair

INTRODUCTION

Bankart repair laxity may contribute to pathologic joint instability. This biomechanical study compared two screw-in suture anchor-suture combinations under tensile loads.

METHODS

Twelve pairs of scapulae were implanted with either a 3 mm diameter, 14 mm long poly-L/D-lactide suture anchor with a suture eyelet (Group 1) or a 3.1 mm diameter, 11 mm long polylactide suture anchor with a molded eyelet (Group 2). Constructs were cyclically loaded between 25 and 50 N with a 25 N load increase every 25 cycles.

RESULTS

Group 2 displayed greater displacement at failure, had more specimens with > or =2 mm displacement by the 50 N interval (P = 0.014), and had displaced more by 100 N (P < or = 0.046). Group 1 displayed a stronger load-displacement at failure relationship than Group 2 (r (2) = 0.67 vs. r (2) = 0.37).

CONCLUSION

Construct differences may influence decisions regarding the required number of suture anchor-suture loops, the rehabilitation timetable, and the timing of return to unrestricted activities.

Arthroscopic removal of proud metallic suture anchors after Bankart repair

INTRODUCTION

This study presents an arthroscopic removal technique for proud metallic suture anchor after Bankart repair and analyzes the cause of anchor failures.

PATIENTS

Six male patients with an average age 23 years who had proud anchor on the glenoid surface were included. The diagnosis of six patients at the time of the primary surgery was traumatic anterior shoulder instability. Four patients had arthroscopic repair and two had open Bankart repair previously. Four patients complained of pain accompanying a metallic clicking sound during shoulder motion which increased with abduction and external rotation. One patient had pain with apprehension of dislocation and another patient suffered from only pain. Most symptoms had been revealed during the rehabilitation period (average 8.3 months) and confused with postoperative pain. The protruded anchors were detected through plain radiographs in four patients and during arthroscopic examination in two patients.

METHOD

To extract the proud anchor arthroscopically, a screw driver of a larger diameter than that of the proud suture anchor was used to retrieve the anchor. A larger screw driver was striked with a hammer along the previous suture anchor hole to make a room between the suture anchor and the adjacent glenoid bone so that the hole of the suture anchor became larger. After the hole was widened, the suture anchor had enough room to move freely and it could be removed with a grasper or a mosquito easily. The location of the proud anchor was 2, 3 and 5 o'clock in three patients and 4 o'clock in three patients. In two patients, the suture anchor was malpositioned about 5 mm medial from the anterior glenoid rim. All patients had chondral damage on the humeral head.

RESULTS

Following the procedure none had shoulder instability in 3 years of follow-up. Preoperative visual analog scale score for pain was an average of 3.5. The visual analog scale score for pain was decreased to 1.2 after surgery. All patients had a slight limitation of external rotation preoperatively, and they showed a normal range of motion postoperatively. Constant score improved from 65 to 89, and similarly, American Shoulder and Elbow Society score increased from 67 to 88 after the operation.

CONCLUSION

Despite small numbers of patients, a successful removal of proud metal suture anchors was achieved using a large empty suture anchor screw driver, which is a simple and reproducible method to remove a proud metallic suture anchor arthroscopically.

Cyclic loading comparison of Bio-SutureTak-#2 FiberWire and Bio Mini-Revo-#2 Hi-Fi suture anchor-sutures in cadaveric scapulae

This study compared tap-in Bio-SutureTak suture anchor-#2 FiberWire suture (Group 1) and screw-in Bio Mini-Revo suture anchor-#2 Hi-Fi suture (Group 2) fixation in the glenoid region of interest for Bankart repair, in addition to evaluation of isolated suture loop biomechanical properties under progressive incremental cyclic loads. With knowledge of glenoid apparent bone mineral density (BMD), implant preparation and fit characteristics, and following application of a light manual tensile load, the primary investigator scored each specimen for perceived within group biomechanical test performance using a 0-10 point modified visual analog scale. After scoring, 12 paired constructs were placed in a servo hydraulic device clamp, preloaded to 25 N, and cycled between 25 and 50 Hz with a 25 N load increase every 25 cycles. Group 2 withstood greater load (104.1 +/- 56 vs. 70 +/- 36.9 N, P = 0.04) and displaced more at failure (13 +/- 4.5 vs. 8.6 +/- 3.3 mm, P = 0.04). All Group 1 specimens failed prior to reaching 150 N, whereas 25% of Group 2 specimens (n = 3) failed at 200 N. All specimens failed by anchor pullout except for three Group 2 specimens that failed by eyelet breakage at 200 N. Isolated suture testing revealed that Group 1 sutures displaced less at each cyclic load (P = 0.028) and withstood greater failure loads (P = 0.028) than that of Group 2 sutures. Group 2 constructs displayed moderately strong relationships between perceived within group biomechanical test performance and ultimate load (r (2) = 0.55) and displacement at failure (r (2) = 0.67). Group 1 did not display significant relationships. Similar biomechanical performance between 50 and 125 N, greater load at failure, and superior biomechanical test prediction accuracy suggest that the screw-in type Bio Mini-Revo suture anchor-#2 Hi-Fi suture combination may be preferred for Bankart lesion repair in low apparent BMD glenoid processes. The #2 Hi-Fi suture, however, allowed significantly greater displacement than the #2 FiberWire suture at each progressive cyclic load interval.

Revision using modified transglenoid reconstruction in recurred glenohumeral instability combined with anchor-induced arthropathy

A 25-year-old man presented with a history of pain and crepitus in the right shoulder; he had been previously treated with arthroscopic anterior stabilization using four metallic suture anchors for recurrent traumatic anterior instability 1 year earlier. In this report, we present a patient with recurrent glenohumeral instability combined with anchor-induced arthropathy who was managed with modified arthroscopic transglenoid reconstruction following arthroscopic suture anchor retrieval.

Suture anchors and tacks for shoulder surgery, part II: the prevention and treatment of complications

The use of suture anchors and tacks around the shoulder requires a thorough knowledge of the proper use of the devices and how to insert them. Although typically not technically demanding, suture anchors and tacks can present unique and frustrating challenges to the patient and the surgeon. These challenges can occur whether the procedure is performed via an open or arthroscopic approach, but knowledge of the potential challenges may optimize the surgical result and prevent complications. Complications can be categorized as technique-related or device-related issues (mechanical or biologic failure). Technique-related complications include problems with the delivery systems, anchor malpositioning, and suture management issues, such as knots not sliding. Device-related complications include implant fracture, migration secondary to poor fixation, synovitis from implant degradation, and osteolysis. This review describes the prevention of these and other complications, addresses the indications or need for intervention, and suggests potential solutions when intervention is indicated.

Failure of anterior shoulder instability repair caused by eyelet cutout of absorbable suture anchors

Repair of soft tissue to bone is increasingly frequently performed using absorbable suture anchors. If a repair fails clinically, it is often impossible to identify the cause of failure at repeat surgery. We report on 2 cases of recurrence of instability after arthroscopic Bankart repair. In reoperation in these cases, all sutures were correctly knotted around the labrum but were intact and torn out of the anchor eyelets. No sign of anchor displacement (3 anchors in each patient) was seen. This is the first clinical report of unambiguous structural suture anchor failure. These observations emphasize the sensitivity of Bankart repair to weak links in the repair chain, which must be avoided.

Glenohumeral arthropathy after arthroscopic anterior shoulder stabilization

PURPOSE

We present 5 cases of iatrogenic arthropathy after arthroscopic Bankart reconstruction using a metallic suture anchor.

TYPE OF STUDY

Retrospective case series.

METHODS

Five patients with pain and crepitus on motion were referred to our institution for further evaluation of the previous procedure on anterior shoulder instability. Screw-type metallic suture anchors were used in all cases. All patients were men, with an average age of 23 years (range, 21 to 26). Surgical records on previous procedure were reviewed, and the clinical symptoms were evaluated using a visual analogue scale (VAS), the Simple Shoulder Test (SST), and the Rowe scoring system. The secondary surgery for each patient was performed at an average of 12 months (range, 7 to 20) after the initial arthroscopic stabilization, except in one patient who wanted to postpone the revision surgery.

RESULTS

Protrusion of the anchor tip was seen in all and chondral defects in the humeral head with some degree of synovitis were also seen. Slight differences between preoperative and postoperative pain were seen, but almost no improvement in function, including range of motion, stability, and average Rowe score were seen after the second procedure. Patients who underwent revision surgery were dissatisfied with the final outcomes.

CONCLUSIONS

Careful attention should be paid when using a metallic suture anchor. A secure, buried placement of the anchor is required in arthroscopic Bankart reconstruction. Poorly placed suture anchors may damage the glenohumeral joint, and if these are not corrected either at arthroscopic surgery or shortly after, the results can be suboptimal. If a patient complains of unusual mechanical symptoms after using anchors, radiographs should be performed. This kind of serious complication can be discovered earlier to prevent the severe destruction of the glenohumeral joint.

LEVEL OF EVIDENCE

Level IV.

The use of acrylic bone cement for suture anchoring

Healing of tendon or ligament sutured to bone depends among other parameters on the mechanical stability of the suture fixation in or to the bone. The authors propose a method of anchoring suture material using bone cement as a substitute for conventional suture anchors. Conditions for secure fixation of suture material in bone cement were assessed and the technique of anchoring suture material with acrylic cement in bone was developed. Mechanical testing and microcomputed tomography of the suture-cement-bone compound were done. It was found that the suture always should be knotted before embedding it at least 2 mm deep in the bone cement. The holes drilled into the bone in which the sutures are secured with cement should be at least 3.5 mm in diameter and 10 mm deep; in cortical bone a tapped thread is required. Sutures can be secured safely using cement anchors which provide higher pull-out strength of a factor two to five than conventional metallic suture anchors of comparable size. They also adapt to anatomic situations where conventional anchors cannot be used and are more favorable in osteoporotic bone. Cement anchoring of sutures seems to be a cost-effective and valuable alternative when there is poor bone quality or extraordinarily high mechanical load.

Late disengagement of a knotless anchor

The knotless anchor is a new type of suture anchor that eliminates the need to perform arthroscopic knots, thus facilitating the performance of arthroscopic shoulder surgery. We report our experience in the use of this type of anchor in arthroscopic Bankart repair and discuss a complication related to using this type of fixation device.

Complications associated with arthroscopic shoulder surgery

We review the literature on complication of arthroscopic shoulder surgery and their management. Computer data based searches were used to identify articles regarding complications of shoulder arthroscopy, as well as hand searches of Arthroscopy and Journal of Shoulder and Elbow Surgery over the last decade. Arthroscopic shoulder surgery has become a popular therapeutic and diagnostic procedure during the past two decades. As with all interventions complications can occur which require recognition and management by the orthopedic surgeon. While the literature is helpful with identifying types of complications, establishing the rate of these complications remains elusive. These complications can be divided into general complications, complications generic to all shoulder procedures, and complications specific to the type of procedure performed. General complications such as infection and anesthesia problems continue to show low incidences. Shoulder arthroscopy presents increased risk of complications over knee arthroscopy in regard to vascular and neurologic injury, fluid extravasation, stiffness, iatrogenic tendon injury, and equipment failure. New techniques of increased complexity for subacromial surgery, rotator cuff repair, and arthroscopic instability present new problems related to implant failure, nerve injury, iatrogenic fracture, and capsular necrosis. While the rate of complications especially with newer procedures remain elusive, most studies suggest that the rate is low, 5.8-9.5% in all recent review studies published. Underreporting complications makes assessment of incidence rates of complication difficult. Proper patient selection, attention to operative detail, and careful post-operative monitoring can minimize the morbidity associated with these complications.

Use of an allograft bone button for rotator cuff repair

Bone button anchors constructed from allograft bone were investigated as an alternative for rotator cuff repair. Bone button anchors were used in 59 consecutive procedures after mechanical pullout strength and cyclical loading bench testing. Sequential radiographs demonstrated that the anchors locked in cancellous bone and provided consistent fixation with no loosening or lysis in 1 year of clinical follow-up. Mechanical testing demonstrated mean, pullout strength of 160.2 N (36 lbs), and the anchors did not migrate when cyclically loaded. Clinical results showed an allograft anchor is viable for rotator cuff tendon repair.

Arthroscopic versus open Bankart repair for traumatic anterior shoulder instability

After more than 15 years of experience, arthroscopic shoulder stabilization is becoming less controversial. Historically, recurrence rates following arthroscopic stabilization have been higher than with open stabilization. Although a negligible advantage may exist in terms of expedited postoperative rehabilitation and improved postoperative recovery of motion, critics suggest that its use in contact athletes be limited. The indications for arthroscopic stabilization are expanding, in part, because of improved understanding of the pathophysiology of shoulder instability. Understanding the mechanism of recurrent instability following arthroscopic stabilization offers clues to how physicians can prevent unsatisfactory results in the future. With newer instrumentation and the ability to thermally treat capsular tissue, coexisting pathology, such as capsular plastic deformation, rotator interval lesions, and unrecognized intra-articular pathology, can now be addressed arthroscopically. The judicious use of these techniques is warranted until long-term study results become available. Ideal patients for arthroscopic Bankart repair have a discrete Bankart lesion; a robust, well-developed IGHL; no significant capsular laxity or intraligamentous injury; and an absence of concomitant intra-articular pathology. Additional findings on MR imaging or CT evidence of a discrete labral lesion and pure unidirectional anterior instability during EUA are also good prognostic indicators for arthroscopic Bankart repair. Arthroscopic criteria that render patients less appropriate for an arthroscopic repair include capsular injury, capsular laxity, a bony Bankart lesion, glenohumeral arthritis, and a rotator cuff tear. The authors' believe that either absent or patulous, poorly developed glenohumeral ligaments represent a poor prognostic indicator for a successful outcome following standard arthroscopic Bankart repair. Individuals with poor-quality tissue are more predictably managed using open capsulorrhaphy. Patients with pathologic ligamentous laxity in the absence of a Bankart lesion or any apparent intraligamentous injury to the IGHL are also good candidates for treatment with an open capsulorrhaphy. Findings determined from a thorough physical examination, EUA, and the pathology appreciated during diagnostic arthroscopy help to appropriately choose the surgical procedure that effectively addresses pathology in patients who present with recurrent traumatic anterior instability. Patient preferences and surgical experience are important determinants of procedure selection, and current arthroscopic techniques lack the versatility to uniformly address the entire spectrum of pathology that may be associated with traumatic anterior shoulder instability. Surgeons should always be prepared to convert to an open-stabilization technique if the arthroscopic technique is deficient in addressing all pathology identified at the time of surgery.

Arthroscopic shoulder instability surgery. Complications

Complications associated with arthroscopic shoulder stabilization are relatively common. Excluding recurrence, complications are rarely disabling. Current statistics undoubtedly underestimate the true incidence of complications. Many complications, including neurovascular injuries and articular damage, are preventable and can be minimized through familiarity with anatomy, proper surgical technique and instrumentation, and clinical experience. Nevertheless, despite these efforts, a few complications, including recurrent instability, persist. Despite careful patient selection and attention to labral pathology and capsular laxity, arthroscopic repairs continue to have success rates lower than those achieved through open means. While cautiously proceeding toward a more complete understanding of the instability continuum, surgeons must maintain a high index of suspicion for new techniques that purport to "solve" the problem of arthroscopic shoulder stabilization, lest the history of enthusiastic but ultimately unsubstantiated claims is repeated. Outcomes must withstand the rigors of scientific scrutiny and the test of time. Without this cautious vigilance, the appeal of today's solutions becomes the fodder of tomorrow's articles about the complications of arthroscopic shoulder stabilization.