A biomechanical comparison of two suture anchor configurations for the repair of type II SLAP lesions subjected to a peel-back mechanism of failure

Biomechanical Studies for Glenoid Based Labral Repairs With Suture Anchors Do Not Use Consistent Testing Methods: A Critical Systematic Review

PURPOSE

The purpose of this systematic review was to investigate variability in biomechanical testing protocols for laboratory-based studies using suture anchors for glenohumeral shoulder instability and SLAP lesion repair.

METHODS

A systematic review of Medline, Embase, Scopus, and Google Scholar using Covidence software was performed for all biomechanical studies investigating labral-based suture anchor repair for shoulder instability and SLAP lesions. Clinical studies, technical notes or surgical technique descriptions, or studies treating glenoid bone loss or capsulorrhaphy were excluded. Risk of bias (ROB) was assessed with the ROBINS-I tool. Study quality was assessed with the Quality Appraisal for Cadaveric Studies. Heterogeneity was assessed with the I² statistic.

RESULTS

A total of 41 studies were included. ROB was serious and critical in 27 studies, moderate in 13, and low in 1; 6 studies had high quality, 21 good quality, 10 moderate quality, 2 low quality, and 2 very low quality. Thirty-one studies used and 22 studies included cyclic loading. Angle of anchor insertion was reported by 33 studies. The force vector for displacement varied. The most common directions were perpendicular to the glenoid (n = 9), and anteroinferior or anterior (n = 8). The most common outcome measures were load to failure (n = 35), failure mode (n = 23), and stiffness (n = 21). Other outcome measures included load at displacement, displacement at failure, tensile load at displacement, translation, energy absorbed, cycles to failure, contact pressure, and elongation.

CONCLUSION

This systematic review demonstrated a clear lack of consistency in those cadaver studies that investigated biomechanical properties after surgical repair with suture anchors for shoulder instability and SLAP lesions. Testing methods between studies varied substantially with no universally applied standard for preloading, load to failure and cyclic loading protocols, insertion angles of suture anchors, or direction of loading. To allow comparability between studies standardization of testing protocols is strongly recommended.

Reported Technical Aspects of Type II SLAP Lesion Repairs in Athletes

Purpose

To systematically review the available literature to further describe and report the available data on SLAP repair techniques and the association with outcomes.

Methods

A systematic review of literature was performed on manuscripts describing type II SLAP repairs in athletes. Selection criteria included studies reporting exclusively type II SLAP tears without concomitant pathology, minimum 2-year postoperative follow-up, use of anchor fixation, and return to previous level of play data available. We extracted patient outcome as well as surgical construct details from each article. Average outcomes and return to play rates were calculated and substratified further by athlete type. Return to play rates were compared by repair constructs with the Student t test.

Results

Initial search resulted in 107 articles. After exclusion criteria were applied, 17 articles were included in the final analysis. Overall, 84% of patients had good-to-excellent results. Of all athletes, 66% returned to previous level of play. There was significant variation in reported technique in terms of anchor number, location, material, suture type, and knotless versus knotted constructs. No significant difference was reported in outcomes in comparison of suture type (P-value .96) or knotted versus knotless constructs (P-value .91). Given the significant variability in reporting, no statistical analysis was felt able to be performed on anchor location and number.

Conclusions

Repair of type II SLAP tears in athletes is a difficult problem to treat with overall low return to play despite a high rate of “good” outcomes when assessed by outcome measures. Significant variability exists in surgical technique, as well as reporting of surgical technique, potentially limiting the ability to define the best or most effective technique for SLAP repair.

Level of Evidence

IV, systematic review of level III and level IV studies.

Biomechanical Comparison of Knotless All-Suture Anchors and Knotted All-Suture Anchors in Type II SLAP Lesions: A Cadaveric Study

PURPOSE

To compare the biomechanical performance of knotless versus knotted all-suture anchors for the repair of type II SLAP lesions with a simulated peel-back mechanism.

METHODS

Twenty paired cadaveric shoulders were used. A standardized type II SLAP repair was performed using knotless (group A) or knotted (group B) all-suture anchors. The long head of the biceps (LHB) tendon was loaded in a posterior direction to simulate the peel-back mechanism. Cyclic loading was performed followed by load-to-failure testing. Stiffness, load at 1 and 2 mm of displacement, load to repair failure, load to ultimate failure, and failure modes were assessed.

RESULTS

The mean load to repair failure was similar in groups A (179.99 ± 58.42 N) and B (167.83 ± 44.27 N, P = .530). The mean load to ultimate failure was 230 ± 95.93 N in group A and 229.48 ± 78.45 N in group B and did not differ significantly (P = .958). Stiffness (P = .980), as well as load at 1 mm (P = .721) and 2 mm (P = .849) of displacement, did not differ significantly between groups. In 16 of the 20 specimens (7 in group A and 9 in group B), ultimate failure occurred at the proximal LHB tendon. Failed occurred through slippage of the labrum in 1 specimen in each group and through anchor pullout in 2 specimens in group A.

CONCLUSIONS

Knotless and knotted all-suture anchors displayed high initial fixation strength with no significant differences between groups in type II SLAP lesions. Ultimate failure occurred predominantly as tears of the proximal LHB tendon.

CLINICAL RELEVANCE

All-suture anchors have a smaller diameter than solid anchors, can be inserted through curved guides, preserve bone stock, and facilitate postoperative imaging. There is a paucity of literature investigating the biomechanical capacities of knotless versus knotted all-suture anchors in type II SLAP repair.

Complications and Return to Activity After Arthroscopic Repair of Isolated Type II SLAP Lesions: A Systematic Review Comparing Knotted Versus Knotless Suture Anchors

Background:

Superior labral anterior to posterior (SLAP) tears are one of the most common injuries to the shoulder, with the type II variant representing the most frequently encountered subtype.

Purpose:

To systematically review the literature to better understand outcomes after arthroscopic repair of isolated type II SLAP lesions using knotted versus knotless anchors based on implant number, implant location, patient position, and portal position.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

A systematic review investigating all studies in the literature between January 2000 and June 2019 reporting on patients undergoing arthroscopic repair for isolated type II SLAP lesions using knotted versus knotless suture anchors was performed following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using the PubMed, BIOSIS Previews, SPORTDiscus, PEDro, and Embase databases.

Results:

A total of 234 patients undergoing isolated arthroscopic repair of type II SLAP lesions using suture anchors were identified, with 76% (179/234) treated using knotted anchors versus 24% (55/234) treated using knotless anchors. Complications were reported in 12% of patients treated using knotted anchors versus no patients treated using knotless anchors (P = .008). The incidence of complications for knotted anchor repair was not significantly affected by patient position (P = .22) or portal position (P = .19). Using multiple regression analysis, we found no significant association with the incidence of complications when analyzing for anchor design (R² = 0.02; P = .06) or anchor position (R² = 0.02; P = .92). No significant difference in return-to-activity timing was appreciated based on anchor type (P = .28), patient position (P = .98), or portal position (P = .97) in patients treated using knotted anchors.

Conclusion:

Patients treated using knotted anchors were significantly more likely to experience a postoperative complication compared with patients treated using knotless anchors after arthroscopic repair of isolated type II SLAP lesions. Despite the increased incidence of a postoperative complication after knotted anchor fixation compared with knotless anchor fixation, multiple regression analysis showed that anchor design and anchor position were not significantly predictive of the incidence of complications. Given the increasing popularity of knotless anchor fixation, further study on the long-term outcomes after knotless repair for isolated type II SLAP lesions is warranted.

Bankart repair alone in combined Bankart and superior labral anterior-posterior lesions preserves range of motion without compromising joint stability

Hypothesis

The purpose was to investigate joint stability and range of motion after a Bankart repair without superior labral anterior-posterior (SLAP) repair (termed “Bankart repair”) and after combined Bankart and SLAP repairs (termed “combined repair”).

Methods

Eight fresh-frozen shoulders were used. Combined Bankart and SLAP lesions were created (10- to 6-o'clock positions). The labrum and capsule were repaired at the 2-o'clock, 3:30 clock-face, and 5-o'clock positions in the Bankart repair group and at the 11-o'clock, 1-o'clock, 2-o'clock, 3:30 clock-face, and 5-o'clock positions in the combined repair group. The internal- and external-rotation ranges of motion were determined with the arm positioned at 0° and 60° of glenohumeral abduction. The rotation angle was defined when a constant torque of 200 N-mm was applied. Joint stability was measured with a custom stability-testing device. The peak translational force in the anterior-posterior direction was measured with the arm at the end range of external rotation.

Results

External rotation angles were greater at 0° and 60° of abduction in the Bankart repair group than in the combined repair group (0° of abduction, P < .01; 60° of abduction, P < .05). The internal rotation angle was greater at 60° of abduction in the Bankart repair group than in the combined repair group (P < .01). The stability between the 2 groups was not significantly different (P = .60).

Conclusion

In patients with combined Bankart and SLAP lesions and the need for a wide range of motion, a Bankart repair alone may provide a greater range of motion without compromising the joint stability at the end range compared with a combined repair.

Molecular Pattern and Density of Axons in the Long Head of the Biceps Tendon and the Superior Labrum

The type II superior labrum anterior to posterior (SLAP) repair is a viable option in young and demanding patients, although a prolonged period of pain after surgery is described in the literature. The reason for this fact remains unknown. Thus, the purpose of this study was to investigate the molecular pattern of the biceps tendon anchor, where the sutures for repair are placed. The long head of the biceps tendon (LHBT), including the superior labrum, was dissected in the setting of reverse total shoulder arthroplasty. Immunohistochemical staining was performed using neurofilament (NF) and protein gene product (PGP) 9.5 as general markers for axons and calcitonin gene-related peptide (CGRP) and substance P for nociceptive transmission. A quantitative assessment was performed according to the two regions of interest (ROIs), i.e., the anterosuperior (ROI I) and the posterosuperior labrum (ROI II). Eleven LHBTs with a mean age of 73 years (range: 66–87 years) were harvested intraoperatively. Six LHBTs were gained in osteoarthrosis and five in fractures. We found an inhomogeneous distribution of axons in the anterosuperior and posterosuperior parts of the labrum in all the specimens irrespective of the age, gender, and baseline situation. There was a significantly higher number (p < 0.01) as well as density (p < 0.001) of NF-positive axons in ROI I compared to ROI II. Nociceptive fibers were always found along the NF-positive axons. Thus, our results indicate that the biceps tendon anchor itself is a highly innervated region comprising different nerve qualities. The anterosuperior labrum contains a higher absolute number and density of axons compared to the posterosuperior parts. Furthermore, we were able to prove the presence of nociceptive fibers in the superior labrum. The results obtained in this study could contribute to the variability of pain after SLAP repair.

Arthroscopic Repair of Type II SLAP Lesions in Overhead Athletes

For overhead athletes and, in particular, baseball pitchers, the rates of success and return to play for those who have undergone arthroscopic repair of type II SLAP lesions are poor, ranging from 7% to 62%. The reasons for the poor results and high failure rates in overhead athletes with type II SLAP repairs are multifactorial and are a combination of many factors. These factors include the failure to establish the diagnosis and treat these athletes preoperatively; the inability of the operating surgeon to differentiate normal anatomic variants from pathologic SLAP lesions at the time of surgery; the surgical technique, which may violate the rotator cuff; or the placement of suture anchors, which restricts external rotation and alters overhead throwing mechanics. The proper diagnosis of SLAP lesions can be difficult because SLAP tears rarely occur in isolation and are often associated with other shoulder pathology. A proper history detailing the onset of symptoms and whether there was an acute episode of trauma or a history of repetitive use is critical. It is important to remember that no single physical examination finding is pathognomonic for SLAP tears. When seen in isolation, SLAP tears may mimic impingement syndrome (52%) or even anterior instability (39%). Surgical treatment of type II SLAP lesions should not be undertaken lightly in overhead athletes. If a 3-month rehabilitation period followed by a return to sports over the following 3 months does not allow the athlete to return to his or her preinjury level, diagnostic arthroscopy with SLAP repair is a reasonable option and can yield excellent results using the proper techniques. The technique described in detail in this article and our video can be technically demanding, but with the key points outlined, it can be reproduced and provide excellent results for overhead athletes undergoing SLAP repair. By not violating the rotator cuff, using a mattress configuration and keeping the suture knot away from the articular surface, and by not going anterior to the biceps tendon for repair, external rotation and strength can be preserved, leading to an excellent result with a predictable return to play for overhead athletes.

Assessments of activities of daily living after arthroscopic SLAP repair with knot-tying versus knotless suture anchors

PURPOSE

The clinical influence of knot-tying or knotless anchor systems for the arthroscopic repair of SLAP lesions (superior labrum lesion from anterior to posterior) remain unclear.

MATERIALS AND METHODS

In a retrospective cohort analysis, 61 of 78 (78.2%) patients with isolated symptomatic SLAP II lesions were examined with a minimum of 24 months after arthroscopic SLAP repair compared to a control group: 28 patients with knot-tying anchors (group I, G1; 28.95 ± 9.48 years, 23 male/5 female), 33 with knotless anchors (group II, G2; 31 ± 10.09 years, 26 male/7 female) and 140 healthy volunteers (group III, G3; 30.9 ± 8.9 years, 109 male/31 female). The clinical assessment included an examination and estimated parameters of ADL (activities of daily living), the CS (Constant score), ASES (American Shoulder and Elbow score), DASH (disability of arm-shoulder hand) and the RS (Rowe score).

RESULTS

The ROM analysis recorded no significant differences for the external rotation in 0° abduction (G1 63.75° ± 15.55° versus = vs G2 65.30° ± 18.15°; p_{ERG1 vs G2} = 0.72). The clinical outcomes revealed significantly decreased pain status in G1 for the O'brien test and in G2 for the Palm-up test, whereas Yergason test showed similar pain levels (p_O'brien = 0.03; p_{palm up} = 0.02; p_yergason > 0.5). The pulley associated rotator cuff tests revealed a significantly inferior force status in G2 compared to G1 (p_lift-off = 0.005, p_Jobe = 0.02) whereas the further rotator cuff assessments were equal. In general, the intervention group showed increased pain level and functional deficits compared to the G3. The score analysis detected no significant differences with P_{CSG1 vs G2}, P_{ASESG1 vs G2}, P_{DASHG1 vs G2} and P_{RSG1 vs G2} all > 0.05 and significant impairments compared to G3 in all scores p_{G1/G2 vs G3} < 0.05 (CS_G1 = 88.28 ± 14.42, CS_G2=92.73 ± 9.24, CS_G3 = 96.2 ± 4.96; ASES_G1 = 81.10 ± 21.69, ASES_G2 = 85.35 ± 17.12, ASES_G3 = 94.95 ± 10.39,; DASH_G1= 35.75 ± 13.44, DASH_G2 = 36.03 ± 17.55, DASH_G3 = 27.13 ± 6.52; RS_G1 = 90.71 ± 9.88, RS_G2 = 88.33 ± 11.22, RS_G3= 92.96 ± 11.27).

CONCLUSIONS

The clinical assessment revealed for both anchor systems similar outcomes but showed general underestimated impairments after the SLAP repair surgery compared to the healthy control. The clinical status only marginally differed between both techniques, wherefore the present assessment of ADL allowed no recommendation of one of these two specific surgery technique for SLAP repair.

Current trends in the evaluation and treatment of SLAP lesions: analysis of a survey of specialist shoulder surgeons

Background

Controversies exist in the classification and management of superior labral anterior and posterior (SLAP) lesions. Our aims were to assess the concordance rate of a group of specialist shoulder surgeons on the diagnosis of SLAP types and to assess the current trends in treatment preferences for different SLAP types.

Methods

Shoulder surgeons (N = 103) who are members of the Shoulder and Elbow Society of Australia were invited to participate in a multimedia survey on the classification and management of SLAP lesions. Response rate was 36%. The survey included 10 cases, each containing a short clinical vignette followed by an arthroscopic video depicting varying types of SLAP lesions. Surgeons were asked to classify the lesions and to recommend treatment.

Results

There is low interobserver agreement in classifying SLAP lesions. The most common misdiagnosis of type I lesion was as a type II, and vice versa. Surgeons preferred to treat type II SLAP lesions in younger patients (<35 years) with labral repair and in older patients with biceps tenodesis. The most commonly preferred repair technique for type II lesion was with suture anchors placed both anterior and posterior to the biceps tendon. For all lesion types, biceps tenotomy was a far less commonly preferred procedure than biceps tenodesis.

Conclusion

There is poor agreement between contemporary surgeons in the classification and treatment of SLAP lesions. The age of the patient appears to play a significant factor in the surgeons' deciding to treat a SLAP lesion with repair vs. biceps tenodesis.

Arthroscopic Repair of Type II SLAP Tears Using Suture Anchor Technique

Arthroscopic SLAP tear repair has become an increasingly used treatment for patients presenting with symptomatic SLAP tears after failed nonoperative management. Debridement, SLAP repair, and open or arthroscopic biceps tenodesis or tenotomy have been used for the treatment of SLAP tears. Various techniques for repair have been described, and furthermore, there is a high incidence of concomitant pathology of the shoulder. Repair remains an excellent option in isolated SLAP tears amenable to repair, with excellent outcomes in well-indicated patients. We present a method for repairing a SLAP tear using standard suture anchor fixation, anterior and posterior portals, and an accessory portal of Wilmington. Adequate labral repair can be achieved with this technique in patients with no concomitant biceps pathology. This report highlights this technique for SLAP repair in patients with isolated symptomatic SLAP tears that have failed conservative management.

Current Practice for the Surgical Treatment of SLAP Lesions: A Systematic Review

PURPOSE

To analyze current literature reporting surgical treatment of SLAP lesions to examine the consistency of reported surgical details (surgical indications, surgical technique, and postoperative rehabilitation) that are deemed important for best treatment outcomes and to try to establish a consensus regarding treatment.

METHODS

A systematic review of papers reporting surgical treatment of a SLAP lesion was performed. Each paper was analyzed for the description of (1) the arthroscopic indications for surgery; (2) surgical aspects including type, location, and number of anchors and sutures; (3) description of criteria for determination of completeness of the repair; and (4) postoperative rehabilitation details. These findings were also analyzed to determine whether a consensus could be developed regarding surgical treatment.

RESULTS

Twenty-six papers were included, with 12 focused on isolated SLAP repair and 14 focused on combined SLAP repair with other lesions; 54% did not report indications for surgery. Reporting of the anchor/suture details was not consistent, with 35% reporting some variation of 12:00 placement but 31% not reporting the position of placement; 89% of papers did not report the criteria for determining completeness of the repair; 85% reported general postoperative rehabilitation guidelines, but only 4% reported in-depth details.

CONCLUSIONS

This review demonstrated a wide variability in the reported surgical aspects and that a relatively high percentage of papers did not report many of the details. This lack of precision and consistency makes analysis of individual papers and comparison between papers and their outcomes difficult and does not allow a consensus regarding current practice to be developed. These findings may be some of the factors responsible for the variability in treatment outcomes and suggest that efforts could be directed toward consistency in documenting and reporting surgical indications, surgical techniques, surgical endpoints, and efficacious rehabilitation programs.

LEVEL OF EVIDENCE

Level IV, systematic review of level III-IV studies.

Simplified Knotless Mattress Repair of Type II SLAP Lesions

Arthroscopic repair of lesions of the superior labrum and biceps anchor has been shown to provide good to excellent results. We describe a simplified arthroscopic surgical technique using a single knotless anchor with a mattress suture configuration. This technique provides an effective and reproducible method to reattach and re-create the normal appearance of the superior labrum and biceps anchor in a time-efficient manner without the need for knot tying.

Superior labral anterior posterior lesions of the shoulder: Current diagnostic and therapeutic standards

Surgical treatment of superior labral anterior posterior (SLAP) lesion becomes more and more frequent which is the consequence of evolving progress in both, imaging and surgical technique as well as implants. The first classification of SLAP lesions was described in 1990, a subdivision in four types existed. The rising comprehension of pathology and pathophysiology in SLAP lesions contributed to increase the types in SLAP classification to ten. Concerning the causative mechanism of SLAP lesions, acute trauma has to be differed from chronic degeneration. Overhead athletes tend to develop a glenohumeral internal rotation deficit which forms the basis for two controversial discussed potential mechanisms of pathophysiology in SLAP lesions: Internal impingement and peel-back mechanism. Clinical examination often remains unspecific whereas soft tissue imaging such as direct or indirect magnetic resonance arthrography has technically improved and is regarded to be indispensable in detection of SLAP lesions. Concomitant pathologies as Bankart lesions, rotator cuff tears or perilabral cysts should be taken into consideration when planning a personalized therapeutic strategy. In addition, normal variants such as sublabral recess, sublabral hole, Buford complex and other less common variants have to be distinguished. The most frequent SLAP type II needs a sophisticated approach when surgical teatment comes into consideration. While SLAP repair is considered to be the standard operative option, overhead athletes benefit from a biceps tenodesis because improved patient-reported satisfaction and higher rate of return to pre-injury level of sports has been reported.

Etiology, Diagnosis, and Management of Failed SLAP Repair

In general, favorable outcomes have been achieved with arthroscopic repair of superior labral anterior-posterior (SLAP) tears. However, some patients remain dissatisfied or suffer further injury after SLAP repair and may seek additional treatment to alleviate their symptoms. The cause of persistent pain or recurrent symptoms after repair is likely multifactorial; therefore, careful preoperative workup is required to elucidate the cause of pain. Review of the details of previous surgical procedures is crucial because certain fixation methods are prone to failure or can cause additional injury. Failed SLAP repair can be managed with nonsurgical or surgical options. Nonsurgical modalities include physical therapy and strengthening programs, anti-inflammatory agents, and activity modification. Surgical options include revision SLAP repair and biceps tenotomy or tenodesis with or without revision SLAP repair. Outcomes after surgical management of failed SLAP repair are inferior to those of primary repair. Select patients may be better served by primary biceps tenodesis rather than SLAP repair.

The thrower's shoulder

Throwers, or athletes who engage in repetitive overhead motions, are a unique subset of athletes that experience distinct shoulder injuries. Athletes engaged in baseball comprise the majority of patients seeking orthopedic care for throwing related injuries. Injuries specific to throwers most commonly involve the labrum and the undersurface of the rotator cuff. In addition, tissue changes in both the anterior and posterior glenohumeral capsule are common with repetitive overhead motions. These capsular changes alter. This article will examine the pathomechanics of injuries to throwers, elaborate means of diagnoses of cuff and labral injury and discuss recent advances in both non-operative and operative interventions, including preventative principles.

Footprint contact restoration between the biceps-labrum complex and the glenoid rim in SLAP repair: a comparative cadaveric study using pressure-sensitive film

PURPOSE

To compare pressurized footprint contact and interface pressure between the biceps-labrum complex and the superior glenoid rim after SLAP repair using 3 different techniques.

METHODS

Twenty-four fresh-frozen human cadaveric shoulders were divided into 3 groups. SLAP lesions were repaired by (1) 2 single-loaded anchors in a simple suture configuration (group T), (2) a double-loaded anchor in a simple suture configuration in a V shape (group V), or (3) a double-loaded anchor by use of a hybrid simple and mattress suture configuration (group H). Pressure-sensitive film quantified pressurized contact areas and interface pressures between the biceps-labrum complex and the glenoid rim after SLAP repair.

RESULTS

Groups T and V showed significantly larger contact areas than group H (P < .0001). However, there was no significant difference between groups T and V. Despite a substantial contact area around the biceps-labrum complex in group T, there was a lack of sufficient contact area just below the biceps anchor. Group V showed a uniform contact area around the entire biceps-labrum complex, but in group H the contact area was concentrated only around the posterior superior labrum, where the simple suture was used.

CONCLUSIONS

The methods using 2 single-loaded suture anchors and using 1 double-loaded suture anchor with a simple suture configuration showed significantly larger pressurized contact areas than the method using 1 double-loaded suture anchor with both a simple and mattress suture configuration. The interface pressure was not significantly different among groups.

CLINICAL RELEVANCE

Although there have been several kinds of repair techniques and biomechanical studies for the type II SLAP lesion, there has been no study about footprint restoration on the superior glenoid rim. This study analyzed and compared the footprint contact restoration after type II SLAP repair among 3 different techniques.

Suture anchors or transglenoidal sutures for arthroscopic repair of isolated SLAP-2 lesions? A matched-pair comparison of functional outcome and return to sports

PURPOSE

Presumably, the technique of SLAP refixation has significant influence on outcome. This study analyzes and compares functional outcome and return to sports after arthroscopic suture anchor (SA) and arthroscopic transglenoidal suture (TS) repair of isolated SLAP-2 lesions.

METHODS

Twenty-four competitive amateur athletes constituted the two treatment groups of this retrospective matched-pair analysis. In the SA group (n = 12), the mean age was 39.1 years (±12.0) and the mean follow-up period was 4.0 years (±0.6). In the TS group (n = 12), the mean age was 33.8 years (±12.0) and the mean follow-up period was 3.7 years (±0.9). The minimum follow-up period was 2.0 years. Primary outcome measures were the absolute constant-score (CS), the subjective shoulder value (SSV) as well as the ability to return to sports.

RESULTS

The mean CS in the SA group was 91.6 (±5.5) compared to 81.3 (±15.5) in the TS group (p = 0.04). The mean SSV after SA repair was 96.9 (±4.6) compared to 80.0 (±20.8) after TS repair (p = 0.01). Both scores showed significantly higher standard deviations within the TS group (p < 0.05). Twelve of eighteen patients (67 %) were able to return to their overhead sports without restrictions (5/9 in the SA group and 7/9 in the TS group; p > 0.05). Fourteen of twenty-four patients (58 %) achieved their preinjury sports levels (8/12 in the SA group and 6/12 in the TS group; p > 0.05).

CONCLUSIONS

Superior objective and subjective shoulder function was obtained following arthroscopic SA repair compared to arthroscopic TS repair of isolated SLAP-2 lesions. In addition, results of SA repair were more predictable. However, nearly half of the athletes did not achieve full return to sports regardless of the applied technique of refixation.

The effect on external rotation of an anchor placed anterior to the biceps in type 2 SLAP repairs in a cadaveric throwing model

PURPOSE

This study examined whether there is a difference in external rotation (ER) between type 2 SLAP repairs consisting of anchors placed only posterior to the biceps insertion compared with repairs with an additional anchor placed anterior to the biceps.

METHODS

Seven cadaveric shoulders from donors with a mean age of 39.4 years were tested. Type 2 SLAP lesions were created, followed by a 3-anchor repair: a standard repair with 2 anchors posterior to the biceps plus an additional anchor anterior to the biceps. The specimens were placed on a material testing system machine and rotation was measured under a constant torque. The sutures were then removed sequentially from anterior to posterior during testing.

RESULTS

The average ER of the intact shoulder was 115.7° ± 2.6°. After SLAP tear creation and cyclic loading, the ER was 118.5° ± 2.6°, which decreased to 116.5° ± 2.6° after repair. This corresponds to a reduction of 2.0° of ER (P < .0001) with the repair. After release of the anterior anchor, the ER increased to 117.9° ± 2.6°, which corresponds to an increase in shoulder motion of 1.4° of ER (P = .0011). Additional release of the middle anchor, leaving only the posterior anchor intact, resulted in 118.0° ± 2.7° of ER, which corresponds to an increase of only 0.1° of ER (P = .7667).

CONCLUSIONS

Following type 2 SLAP repair in the cadaveric shoulder, removing the effect of the anchor anterior to the biceps resulted in a small but statistically significant increase in ER. The anterior anchor had the greatest effect on ER. The presence of 1 or 2 anchors posterior to the biceps did not have a significant effect on rotation.

CLINICAL RELEVANCE

When performing SLAP repairs on those in whom even a small loss of ER would be detrimental, such as baseball pitchers, avoidance of the use of an anchor anterior to the biceps should be considered.

Arthroscopic suture anchor capsulorrhaphy versus labral-based suture capsulorrhaphy in a cadaveric model

PURPOSE

The purpose of this study was to establish whether suture anchor capsulorrhaphy (SAC) is biomechanically superior to suture capsulorrhaphy (SC) in the management of recurrent anterior shoulder instability without a labral avulsion.

METHODS

Twelve matched pairs of shoulders were randomized to either SC or SAC. Specimens were mounted in 60° of abduction and 90° of external rotation. Testing was conducted on an MTS servohydraulic load testing device (MTS, Eden Prairie, MN). A compressive load of 22 N was applied, followed by a 2-N anterior and posterior force to establish a 0 point. Translation with 10-N anterior and posterior loads was recorded for baseline laxity measurement. Arthroscopic capsulorrhaphy was performed with either 3 solitary sutures or 3 suture anchors. Specimens were remounted and returned to the 0 point. Translation was measured with 10-N anterior and posterior loads to determine reduction in translation. Specimens were then loaded to failure to the 0 point at a rate of 0.1 mm/s.

RESULTS

Load to failure was significantly greater (P = .02) in the SC group (13.6 ± 1.0 N) versus the SAC group (20.5 ± 2.8 N). No differences were found between SC (2.7 ± 0.7 mm) and SAC (2.3 ± 0.6 mm) when we compared reduction of anterior translation with a 10-N load. The percent reduction of anterior displacement with a 10-N load was similar for the SC (49.9%) and SAC (49.6%) groups. The dominant mode of failure in the study was suture pull-through of the capsular tissue.

CONCLUSIONS

Our study indicates that labral-based SC and SAC similarly reduce anterior glenohumeral translation at low loading conditions. Load-to-failure studies indicate that SAC exhibits significantly greater resistance to translation at higher loading conditions. Our study suggests that the use of a suture anchor when one is performing a capsulorrhaphy may provide biomechanical advantage at high loading conditions.

CLINICAL RELEVANCE

Our study suggests that when one is performing capsulorrhaphy, the use of a suture anchor may provide biomechanical advantages at high loading conditions.

Biomechanical evaluation of classic solid and novel all-soft suture anchors for glenoid labral repair

PURPOSE

To evaluate the biomechanical performance of an all-soft suture anchor (JuggerKnot; Biomet, Warsaw, IN) in comparison with a classic solid suture anchor (2.4-mm biocomposite SutureTak; Arthrex, Naples, FL) in an in vitro labral repair model.

METHODS

We dissected 12 cadaveric shoulders (mean age, 61 ± 9.4 years), leaving the labrum intact, and bone mineral density was obtained (mean, 0.375 ± 0.06 g/cm(3)). Simulated labral tears were made at the anteroinferior and posteroinferior edges of the labrum. Repairs used 2 all-soft suture anchors (JuggerKnot) or 2 solid anchors with free, high-strength No. 2 suture (FiberWire; Arthrex) spanning the operative construct to load the repair. Differential variable reluctance transducers were used to measure labral displacement for each specimen. The testing protocol consisted of a preconditioning phase at 10 N for 10 cycles (1 Hz) and then a final load-to-failure testing at a rate of 3 mm/min. Labral displacement of 2 mm was determined as the primary outcome.

RESULTS

There was no statistical difference (P = .22) in ultimate load to failure and displacement at ultimate failure (anchor pullout) between the all-soft JuggerKnot (146.0 ± 43.0 N and 19.8 ± 5.4 mm, respectively) and the solid SutureTak (171.9 ± 52.6 N and 22.3 ± 6.8 mm, respectively). The solid anchor had a significantly higher ultimate load at 2 mm of labral displacement than the all-soft suture anchor (84.1 ± 19.0 N and 39.2 ± 10.6 N, respectively; P < .001).

CONCLUSIONS

Whereas both the solid SutureTak and the all-soft JuggerKnot displayed similar results on ultimate load-to-failure testing, the solid anchor required significantly greater load for 2 mm of labral displacement than the all-soft anchor.

CLINICAL RELEVANCE

The all-soft anchor (JuggerKnot) is similar in biomechanical performance to the classic solid anchor (SutureTak) with the exception of load at 2 mm of labral displacement, suggesting micromotion of the device.

Restoration of labral anatomy and biomechanics after superior labral anterior-posterior repair: comparison of mattress versus simple technique

BACKGROUND

Both simple and mattress repair techniques have been utilized with success for type II superior labral anterior-posterior (SLAP) lesions; however, direct anatomic and biomechanical comparisons of these techniques have yet to be clearly demonstrated.

HYPOTHESIS

For type II SLAP lesions, the mattress suture repair technique will result in greater labral height and better position on the glenoid face and exhibit stronger biomechanical characteristics, when cyclically loaded and loaded to failure through the biceps, compared with the simple suture repair technique.

STUDY DESIGN

Controlled laboratory study.

METHODS

Six matched pairs of cadaveric shoulders were dissected, and a clock face was created on the glenoid from 9 o'clock (posterior) to 3 o'clock (anterior). For the intact specimen, labral height and labral distance from the glenoid edge were measured using a MicroScribe. A SLAP lesion was then created from 10 o'clock to 2 o'clock. Lesions were repaired with two 3.0-mm BioSuture-Tak anchors placed at 11 o'clock and 1 o'clock. For each pair, a mattress repair was used for one shoulder, and a simple repair was used for the contralateral shoulder. After repair, labral height and labral distance from the glenoid edge were again measured. The specimens were then cyclically loaded and loaded to failure through the biceps using an Instron machine. A paired t test was used for statistical analysis.

RESULTS

After mattress repair, a significant increase in labral height occurred compared with intact from 2.5 ± 0.3 mm to 4.3 ± 0.3 mm at 11 o'clock (P = .013), 2.7 ± 0.5 mm to 4.2 ± 0.7 mm at 12:30 o'clock (P = .007), 3.1 ± 0.5 mm to 4.2 ± 0.7 mm at 1 o'clock (P = .006), and 2.8 ± 0.7 mm to 3.7 ± 0.8 mm at 1:30 o'clock (P = .037). There was no significant difference in labral height between the intact condition and after simple repair at any clock face position. Labral height was significantly increased in the mattress repairs compared with simple repairs at 11 o'clock (mean difference, 2.0 mm; P = .008) and 12:30 o'clock (mean difference, 1.3 mm; P = .044). Labral distance from the glenoid edge was not significantly different between techniques. No difference was observed between the mattress and simple repair techniques for all biomechanical parameters, except the simple technique had a higher load and energy absorbed at 2-mm displacement.

CONCLUSION

The mattress technique created a greater labral height while maintaining similar biomechanical characteristics compared with the simple repair, with the exception of load and energy absorbed at 2-mm displacement, which was increased for the simple technique.

CLINICAL RELEVANCE

Mattress repair for type II SLAP lesions creates a higher labral bumper compared with simple repairs, while both techniques resulted in similar biomechanical characteristics.

Vertical versus horizontal suture configuration for the repair of isolated type II SLAP lesion through a single anterior portal: a randomized controlled trial

PURPOSE

To compare the clinical and functional outcomes of the repair of an isolated type II SLAP lesion by 2 different configuration techniques (vertical v horizontal suture) through a single anterior portal.

METHODS

We designed a prospective, double-blinded, randomized clinical trial. A junior orthopaedic surgeon, who made the initial diagnosis, used a 10-point visual analog scale for pain and subjective instability and the American Shoulder and Elbow Surgeons (ASES) scoring system and evaluated the range of motion. After a diagnostic arthroscopy that ascertained the presence of an isolated type II SLAP lesion, patients were randomized to receive either vertical suture configuration (group 1) or horizontal suture configuration (group 2), both through a single anterior portal. Thirty-two patients were included in the study. The mean follow-up time was 37 months.

RESULTS

The mean postoperative ASES score was 91.9 in group 1 versus 95.8 in group 2 (P > .05). The differences observed from preoperative ASES score for both groups to postoperative ASES score were statistically significant. The differences observed in preoperative range of motion from the contralateral healthy shoulder and the affected shoulder in both groups were all clinically and statistically significant. Comparing the overall range of motion of the affected limb postoperatively with the range of motion of the contralateral healthy shoulder and between both groups, we found no statistically significant differences in forward flexion (P = .067), external rotation (P = .101), or internal rotation (P = .343).

CONCLUSIONS

The results of this study suggest that the repair of an isolated type II SLAP lesion through a single anterior portal is clinically and functionally beneficial to patients regardless of the suture configuration performed (vertical or horizontal suture) because no differences were observed between these configurations after repair of an isolated type II SLAP lesion.

LEVEL OF EVIDENCE

Level I, randomized controlled trial.

Poly-L/D-lactic acid anchors are associated with reoperation and failure of SLAP repairs

PURPOSE

This study investigates factors associated with failure and reoperation after glenoid labrum repair.

METHODS

We studied a nonconcurrent cohort of consecutive patients undergoing arthroscopic superior labrum repair at a single institution by 2 fellowship-trained surgeons over a 10-year period.

RESULTS

There were 348 patients included in this study with a mean age of 33.4 years (95% confidence interval [CI], 32.1 to 35.9) and a mean clinical follow-up of 12.3 months (95% CI, 10.9 to 13.8). The overall reoperation rate was 6.3%, with a revision labrum repair rate of 4.3%. Subsequent surgery and failure after arthroscopic labrum repair were significantly correlated with Workers' Compensation claims (odds ratio [OR], 4.6; P < .001; 95% CI, 1.8 to 11.7), the use of tobacco (OR, 12.0; P = .03; 95% CI, 1.2 to 114.9), and the use of absorbable poly-L/D-lactic acid (PLDLA) anchors (100% correlation, P < .001). The OR for having repeat surgery was 12.7 (95% CI, 4.9 to 32.9; P < .001) with poly-96L/4D-lactic acid (Mini-Revo; Linvatec, Largo, FL) and also increased with the use of poly-70L/30D-lactic acid (Bio-Fastak and Bio-Suturetak; Arthrex, Naples, FL) anchor material (P = .04) after removal of the patients exposed to poly-96L/4D-lactic acid anchors. The rates of repeat surgery with PLDLA anchors from Linvatec and PLDLA anchors from Arthrex were 24% and 4%, respectively. None of the patients treated with nonabsorbable suture anchors (polyether ether ketone or metallic) returned to the operating room (P < .001). After we controlled for associated factors in a multivariate analysis, the use of absorbable anchors, in particular poly-96L/4D-lactic acid anchors (OR, 14.7; P < .001), and having a work-related injury (OR, 8.1; P < .001) remained independent factors associated with both repeat surgery and revision superior labrum repair.

CONCLUSIONS

Bioabsorbable PLDLA anchor material led to significantly more SLAP repair failures and reoperations compared with nonabsorbable suture anchors. Our recommendation is that glenoid labrum repairs be performed with nondegradable material and, specifically, that the use of anchors composed of PLDLA material should be avoided.

Freehand versus navigated glenoid anchor positioning in anterior labral repair

PURPOSE

Anchor placement on the glenoid rim is challenging with the angle of insertion critical to achieving satisfactory results. Incorrect anchor placement is a common problem.

METHODS

Three plastic shoulder models were used. Reference markers were attached in the posterior portion of the acromion. Using the navigation system, reference point data from the glenoid were acquired. An anterior labral lesion of the glenoid was created that extended from the 1 o'clock to the 5 o'clock position. Three suture anchors were placed under arthroscopic guidance without the aid of navigation system (Group A) and with the aid of navigation system (Group B). Deviation from the optimal angle of 45° for anchor placement was measured and compared between the two groups.

RESULTS

The mean insertion angles for anchor placement were 45.9° (SD 3.4°, 40.2°-50.4°) and 41.4° (SD 3.9°, 33.1°-47.6°) in the freehand (Group A) and navigated (Group B) groups, respectively. There was a statistically significant difference between the groups (P < 0.05). The mean deviation (from the optimal angle) was 4.2° (SD 3.2°, 0.0°-11.9°) and 2.8° (SD 2.2°, 0.2°-8.4°) in the freehand and navigated groups, respectively.

CONCLUSION

Navigation systems may improve the accuracy of glenoid anchor placement amongst low-volume shoulder surgeons. However, it does not provide any significant advantage over the freehand technique in a plastic shoulder model. Constant multiplanar visualization throughout anchor placement as facilitated by navigation made the procedure more manageable, even for an experienced surgeon.

Fiber components of the shoulder superior labrum

PURPOSE

The purpose of this study was to investigate the anatomy of the superior glenoid labrum focusing on the fiber arrangement of its components.

METHODS

Forty-nine embalmed shoulder girdles were removed and each posterior capsule was incised. After recording the macroscopic findings 12 superior-half glenoids were histologically examined. In nine serially sectioned glenoids, four were cut parallel to and five were cut vertical to the glenoid surface. The remaining three glenoids were radially sectioned at the clock position for each hour between 10:00 and 14:00.

RESULTS

The superior labrum had a semi-circular fiber component along the outer margin of the glenoid. In addition, a so-called 'sheet-like structure' which branched off the rotator interval and contained many elastic fibers, attached to its anterosuperior portion. The fibers of the sheet-like structure mixes with fibers of the semi-circular component and ran posteriorward. The fibers of the long head of the biceps tendon extended posteriorward from its origin along the glenoid edge. These fibers communicated with other labrum fibers and became a major element of the posterior portion.

CONCLUSION

The superior labrum is not homogenous. The posterior portion mainly consists of the robust fiber component of the long head of the biceps tendon. The anterosuperior portion includes fibers of the sheet-like structure which contains numerous elastic fibers. Tensile stress from the rotator interval might be conveyed to the anterosuperior labrum.

Reduction and fixation of the avulsion fracture of the tibial eminence using mini-open technique

The purpose of this prospective study is to present and evaluate a new technique using suture anchors for the treatment of the avulsion fractures of the tibial eminence. Twenty-three consecutive patients with the displaced avulsion fracture of the tibial attachment of anterior cruciate ligament were treated using mini-open technique with suture anchors between 2005 and 2008. According to the classification of Meyers and McKeever, there were 5 type II, 13 type III, and 5 type IV fractures. The median follow-up period was 18 months (range, 12-32 months). The patient assessment included Lysholm score, Tegner score, IKDC score, and radiographic evaluation. The median Lysholm score improved from 32 (range, 28-48) preoperatively to 98 (range, 85-100) postoperatively. The median preoperative Tegner score was 3 (range, 2-5), and the median postoperative Tegner score was 7 (range, 5-9). The global IKDC objective score was normal (A) in 21 knees and nearly normal (B) in 2 knees. At final follow-up, the Lachman test and anterior drawer test were negative. The results showed that mini-open reduction and fixation of avulsion fracture of the tibial eminence with suture anchors have achieved satisfactory results. We suggest the use of this technique for treating avulsion fractures of the tibial eminence.

A cadaveric analysis of the arthroscopic fixation of anterior and posterior SLAP lesions through a novel lateral transmuscular portal

PURPOSE

To compare the most commonly used portals with a novel, lateral transmuscular portal for the treatment of anterior and posterior SLAP lesions.

METHODS

Six paired cadaveric shoulders underwent arthroscopy to assess 3 different instrumentation portals: the anterior-superior lateral (AL) portal, the Neviaser (N) portal, and the Rothman-lateral (RL) transmuscular portal. After each portal was established, 5-mm cannulas were inserted followed by guidewire-assisted placement of implant fixation instruments. Each shoulder was then dissected to assess the relation of the instruments to the surrounding anatomic structures.

RESULTS

When the AL portal was used, instrumentation consistently passed through the rotator interval. When the N and RL portals were used, instrumentation penetrated the rotator cuff muscle belly at a mean distance of 25.75 and 7.67 mm, respectively, from the tendon. The mean angles of entry into the glenoid rim with respect to the glenoid articular surface were 32 degrees, 38 degrees, and -6 degrees for the AL, RL, and N portals, respectively. There was no violation of subchondral bone; however, 2 specimens showed weakened articular surfaces with use of the N portal. The RL portal was the only portal that allowed placement of instrumentation into all 3 zones of the superior glenoid rim (anterior superior, direct superior, and posterior superior) without violation of the subchondral bone and at the recommended 30 degrees to 45 degrees angle of entry.

CONCLUSIONS

The RL portal provides a safe and efficient method of arthroscopic fixation and knot tying of anterior and posterior SLAP lesions by use of a single instrumentation portal.

CLINICAL RELEVANCE

This novel, lateral transmuscular portal allows optimal angles of implant placement in all areas of the superior glenoid and provides a direct, simplified approach for arthroscopic knot tying.

Superior labral tears of the shoulder: pathogenesis, evaluation, and treatment

Lesions of the superior glenoid labrum and biceps anchor are a well-recognized cause of shoulder pain. Advances in shoulder arthroscopy have led to improvements in recognizing and managing superior labral anterior-posterior (SLAP) tears. Recent biomechanical studies have postulated several theories for the pathogenesis of SLAP tears in throwing athletes and the effect of these injuries on normal shoulder kinematics. Advances in soft-tissue imaging techniques have resulted in improved accuracy in diagnosing SLAP tears. However, the diagnosis of clinically relevant SLAP tears remains challenging because of the lack of specific examination findings and the frequency of concomitant shoulder injuries. Definitive diagnosis of suspected SLAP tears is confirmed on arthroscopic examination. Advances in surgical techniques have made it possible to achieve secure repair in selected patterns of injury. Recent outcomes studies have shown predictably good functional results and an acceptable rate of return to sport and/or work with arthroscopic treatment of SLAP tears.

Biomechanical comparison of a knotless suture anchor with standard suture anchor in the repair of type II SLAP tears

PURPOSE

To compare the biomechanical strength of knotless suture anchors and standard suture anchors in the repair of type II SLAP tears.

METHODS

Five pairs of cadaveric shoulders (10 shoulders) were dissected free of soft tissue except for the glenoid labrum and long head of the biceps tendon. Type II SLAP tears were created and repaired with 1 of 2 anchors: the Mitek Lupine suture anchor or the Mitek Bioknotless suture anchor (DePuy Mitek, Raynham, MA). All specimens were preloaded to 10 N, and loaded for 25 cycles in 10 N increments to a maximum of 200 N. If specimens were still intact after 200 N, they were loaded to ultimate failure. The load at which 2 mm of gapping occurred, load to ultimate failure, mode of failure, and the number of cycles to failure were compared using the Wilcoxon signed-rank test.

RESULTS

Load to 2-mm gapping was lower (P = .042) for knotless anchors (70 N) versus knotted anchors (104 N), with similar differences for ultimate failure (74 N v 132 N; P = .043), cycles to 2-mm gapping (133 v 219 cycles; P = .042), and cycles to failure (143 v 297; P = .043). Eight of 10 specimens failed at the soft tissue interface (4 knotless, 4 knotted) and 2 failed by anchor pullout (1 knotted, 1 knotless).

CONCLUSIONS

The results of this study suggest that repair of a type II SLAP with a Mitek knotted suture anchor and mattress suture configuration through the biceps anchor is stronger than repair with a Mitek knotless suture anchor. The most likely method of repair failure was at the suture-soft tissue interface regardless of the type of anchor used. The application of a suture anchor that requires arthroscopic knot tying may be preferable to a knotless anchor for the surgical repair of type II SLAP tears.

CLINICAL RELEVANCE

Repair of type II SLAP tears with knotless suture anchors may allow for the avoidance of arthroscopic knot tying but is weaker than repair with standard suture anchors.