Clinical features and repair integrity after knotless – In situ suture bridge technique in high-grade bursal side rotator cuff tears

Abstract

Introduction

The purpose of study is to describe outcome of the knotless-in-situ suture-bridge repair technique, combining concept of articular-preservation, medial-row knotless, and full-layer repair on the high-grade bursal-side rotator cuff tear (PBS-RCT).

Methods

The repair-technique, on 27 shoulders with PBS-RCT, were retrospectively evaluated. Range of Motion (RoM), visual analog scale (VAS), American Shoulder and Elbow Surgeon (ASES) score were evaluated. Minimal 6-months Post-operative MRI were evaluated for repair-integrity.

Result

RoM evaluation, VAS, and ASES Score were improved significantly (P < 0.01). Post-operative MRI showed intact repaired tendon in 25-patients (96.2%).

Conclusion

Arthroscopic knotless-in-situ suture-bridge repair technique in PBS- RCT showed good functional-outcome and repair-integrity at minimum 2-years after surgery.

1. Introduction

Partial-thickness rotator cuff tear is one of the most common cause of shoulder problems.¹ This pathology can be classified as bursal-side, articular-side, or intra-tendinous tears. Treatments of the high-grade partial bursal side rotator cuff tear (PBS-RCT) are debatable due to lack of consensus regarding the optimal management method.¹ The current evidence does not provide guidance as to the best management for symptomatic PBS-RCTs. Several evolution techniques occur to overcome the high-grade PBS-RCTs.1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 A controversy persists between articular side preservation and conversion to complete tears, full layer and superficial layer only repair, medial row knot tying and knotless. Several literatures showed advantages and disadvantages on each technique.1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12

We previously described a repair technique that collaborated the advantages of articular preservation, medial row knotless, and full-layer cuff tears repair.¹⁰ Here, we report the clinical, radiological results, and the repair integrity and healing status according to MRI of this technique. Then, on this study, we also reported the comparison of medial anchor and anchorless knotless suture bridge repair technique in range of motion, functional outcome, and structural integrity after repair.

2. Methods

2.1. Patient selection

From January 2014 to December 2015, a total of 42 patients with symptomatic bursal-side partial tears of more than 50% of the original thickness, as diagnosed in MRI and confirmed in arthroscopy diagnostic, were underwent arthroscopic repair. Among the 42 patients, 26 patients (27 shoulders (62%)), were included from this study with the criteria: high grade bursal side partial tear more than 50% who were performed bursal side repair with preserving intra-articular surface, full-layer thickness repair, and medial row knotless. The exclusion criteria were small-moderate (less than 50%) bursal side rotator cuff tear, full thickness conversion partial bursal side rotator cuff tear, intra-articular or intra-tendon partial rotator cuff tear, full thickness rotator cuff tear, arthritis of the glenohumeral joint, inflammatory arthropathy, and any fracture or previous infection or previous surgery around the shoulder joint.

Among 26 patients, one patient had bilateral bursal side-partial rotator cuff tears. Twenty-shoulders patients were evaluated and consisted of 14 patients (54%) (medial row anchor group) and 13 patients (46%) (medial row anchorless group). There were 8 males (29.6%) and 18 females (70.4%) with an average age 61 ± 9 years. The average follow-up the time postoperative functional evaluation was 19 ± 6 months. Surgery was performed in the affected left hand in 48.1% and right hand 51.9% (Table 1.).

Table 1.

Baseline demographic data.

Variables	n = 27
Age
Mean ± SD	61 ± 9
Range	45–80
Sex
-Male	8 (29.6)
-Female	19 (70.4)
Duration Follow Up (Months)
Mean ± SD	19 ± 6
Range	10–28
Affected Side
-Left	13 (48.1)
-Right	14 (51.9)
MRI Post Op (Tsugaya)
-Grade I	12 (44.4)
-Grade II	11 (40.7)
-Grade III	3 (11.1)
-Grade IV	1 (3.7)
Bigliani
-Flat	19 (70.4)
-Curve	7 (25.9)
-Hook	1 (3.7)
Rockwood Tilt View X Ray Evaluation
-Flat	7 (25.9)
-Bump	9 (33.3)
-Heel	3 (11.1)
-Keel	7 (25.9)
-Irregular	1 (3.7)
Group
-Anchor	14 (51.9)
-Anchorless	13 (44.4)

2.2. Surgical technique

All surgical procedure were performed by single senior surgeon (B.C) in the single orthopaedic centre. Surgical procedure were performed with the patients in beach chair position under general anaesthesia with an adequate interscalene block. Diagnostic glenohumeral arthroscopy were performed, and accompanying intraarticular lesion was addressed.

The arthroscope is then inserted in the sub-acromial space. The acromion process morphology is inspected and acromioplasty is then performed after the establishment of the lateral portal (one inch from the lateral border or the acromion). Once the acromioplasty has been completed, the scope is turned 180° towards the bursal surface. Complete bursectomy is performed using a 4.5 mm arthroscopic shaver. The arthroscope now is changed to the lateral portal and the adequacy of the acromioplasty is assessed. The bursal sided tear of the rotator cuff is carefully inspected for any extension of the tear into the articular side. Debridement is performed at the edge of bursal tear. The exposed footprint of the rotator cuff was decorticated using the motorized shaver blade. We create another viewing portal, 1 cm below the posterolateral margin of the acromion. A size 7.0- mm Arthroscopic Cannula is then placed at the antero-lateral portal. Once the footprint preparation has been completed, the bursal side tear is now ready for repair.

2.3. Medial anchorless technique

Two heavy strained non-absorbable tapes and two heavy strained non-absorbable sutures are then used as free sutures in the following manner. A cuff passer was preloaded with a 1# PDS suture, functioning as shuttle. From the posterior portal, the suture hook was first pierced 1.5 cm medial from the torn bursal edge. Once the full layer of the cuff has been pierced, the tip of the suture hook is then directed to the torn edge and the PDS suture is relayed. The edge of the PDS suture is then brought out to the lateral working portal. One heavy strained non-absorbable tape and one heavy strained non-absorbable suture were tied together to the shuttle suture and was shuttle relayed to the posterior portal. The second penetration, using cuff passer, is taken about 0.8 cm from the first. Once the full thickness of the cuff has been pierced and the PDS suture has been brought to the torn edge, the other end of the heavy strained non-absorbable tape and the heavy strained non-absorbable suture is then relayed to the cuff. Another portal is then created, about 1-cm anterior to the Acromioclavicular joint, for easier passage and manipulation of the cuff passer. This process is then repeated to relay the another set of heavy strained non-absorbable tape and suture in the anterior half of the rotator cuff (Fig. 1.).

Fig. 1.

Illustration showed A. Configuration of free sutures being relayed through full layer of the rotator cuff B. Configuration Medial Anchorless Knotless Suture Bridge Technique. Arthroscopic View of the right shoulder view from the posterolateral portal using 30° arthroscope. C. The 2 free sutures being relayed through full layer rotator cuff by 2# PDS D. Configuration Medial Anchorless Knotless Suture Bridge Technique.

2.4. Medial anchor technique

A posterolateral portal is used for visualization is created. Posterior and anterosuperior portals are used for taking bites from the tendon, whereas the anterolateral working portal is used for suture management and anchor placement. We refresh and debride the bone crater (the raw surface where the fragment will be located). Then, we put two medial double loaded anchors (2 strands tape and 2 strands suture) at the junction intraarticular supraspinatus remnant-bone crater from anterosuperior portal. A cuff passer was preloaded with a 1# PDS suture, functioning as shuttle. From the posterior portal, the suture hook was first pierced 1.5-cm medial from the torn bursal edge. Once the full layer of the cuff has been pierced, the tip of the suture hook is then directed to the torn edge and the PDS suture is relayed. The edge of the PDS suture is then brought out to the lateral working portal. One heavy strained non-absorbable tape and one heavy strained non-absorbable suture from same medial anchor are retrieved to anterolateral portal. Then those strands are tied together to the shuttle suture and relayed to the posterior portal. The second penetration, using cuff passer, is taken about 0.8-cm from the first. Those steps are performed sequentially from posterior to anterior in similar manner until 4 cuff penetration are accomplished (Fig. 2.).

Fig. 2.

Illustration showed A. Configuration of sutures from two medial anchors being relayed through full layer of the rotator cuff B. Configuration Medial Anchor Knotless Suture Bridge Technique. Arthroscopic View of the right shoulder view from the posterolateral portal using 30° arthroscope. C. Insertion double loaded medial anchor in cartilage and bone junction D. Configuration Medial Anchor Knotless Suture Bridge Technique.

2.5. Lateral row anchors insertion

While all 8 limbs of the free sutures have been relayed, the lateral footprint is identified for anchor placement. A pilot hole is created from anterolateral portal and locating the lateral row anchor site, just lateral to bicipital groove and front to infraspinatus insertion. Each cuff penetration consists of one heavy strained non –absorbable tape and suture. Then, we retrieve the suture and tape, alternately, from each hole. We collect 2 suture strands - 2 tape strands and take those out of anterolateral cannula. The remaining threads are retrieved in the posterior portal to avoid suture entangling. We apply suture less lateral-row anchors. The threads are passed through the anchor. The anchor is inserted through the cannula while the threads are held firmly, ensuring smooth sliding of the anchor on the threads. The anchor is hammered into the pilot hole until the threads start entering the hole. Then, all threads are tightened one by one, and the anchor is hammered fully. After final tightening of the threads, the anchor is locked so that the threads do not loosen and the inserting handle is removed. The threads are cut using a knot cutter. The remaining threads are retrieved through the cannula, and another knotless anchor is used to secure the threads in position. The position of second lateral row suture-less anchors should be 10-mm posterior to the first one, using the same protocol to create suture bridge.

2.6. Postoperative rehabilitation

Postoperative rehabilitation was identical for all patients. Patients were instructed to wear a shoulder brace for 4 weeks. To prevent shoulder stiffness, pendulum exercise and passive gentle range of motion exercise were started from the third day postoperatively. Active assisted range of motion exercise was allowed from 6 weeks, followed by resisted shoulder motion exercise from 3 months after surgery.

2.7. Clinical assessments and radiographic evaluation

Pre-operatively, we evaluated patient's demographic data (age, gender, affected upper extremity) and recorded to patient's medical record. We collected visual analog scale (VAS) for pain, range of motion (ROM), and functional outcomes, assessed at pre-operative and at the last visit. The VAS for pain was recorded from 0 (no pain) to 10 (most severe pain). The ROM of flexion, external and internal rotation at the side, and external rotation at 90° abduction were assessed. Functional outcomes included American Shoulder Elbow Society (ASES) score. We also collected coronal and sagittal measurement in Supraspinatus Outlet view and shoulder Rockwood (30° caudal tilt) view to evaluate acromial spur existence and categorized as acromial spur at risk or not at risk. Acromial spur categorized as ‘at risk’ if the acromial spur shapes are hook (sagittal view) and heel, keel, irregular (coronal view).¹³ Preoperative Acromial Index (AI) and Critical Shoulder Angle (CSA) were evaluated at shoulder true AP view to determine the anatomical risks to sub-acromial problems. Post-operative AI and CSI value were also evaluated to determine the benefits of antero-lateral acromioplasty as a step of surgical procedures.

Bursal-sided partial-thickness rotator cuff tears were diagnosed using preoperative MRI and were confirmed during arthroscopic surgery. After debridement of the adjacent rotator cuff tear, the longest length in anterior-posterior and medial-lateral bursal-sided partial-thickness tears was measured to confirm objectively the diagnosis of high-grade bursal side rotator cuff tears.

Integrity of the repaired tendon was determined at 6–18 months by MRI. Repair integrity on MRI was classified into 5 types according to Sugaya et al.: type I, sufficient thickness with homogenously low intensity; type II, sufficient thickness with partial high intensity; type III, insufficient thickness without discontinuity; type IV, presence of a minor discontinuity; and type V, presence of a major discontinuity. Types IV and V were diagnosed as a re-tear.¹⁴

2.8. Statistical analysis

Results were expressed as mean ± standard deviation or frequency (percentage) as appropriate. Continuous data, according to the results of Shapiro–Wilk test for normal distribution, group differences were analyzed by t-test or Mann-Whitney U test. For the categorical data, the Fisher-Exact test was used to compare the variables between the study groups. Statistical analysis was performed with SPSS version 20.0 for Windows (SPSS Inc., Chicago, IL, USA) and Prism (ver. 7.0, Graph Pad Software,.CA, USA). P values less than 0.05 were considered statistically significant.

3. Result

3.1. Clinical outcome and radiographic evaluation

Medial knotless suture bridge technique in bursal side partial rotator cuff tear showed a significant improvement in range of motion evaluation, VAS score, and ASES Score when the pre-operative scores were compared with those at the time of the final follow-up (P < 0.01) (Fig. 3). Pre-operatively, there were no difference in demographic data and acromial status at risk status between medial row anchor and anchorless groups (p > 0.05) (Table 1). We also found that there was no statistically significant difference in post-operative range of motion, VAS Score and ASES Score between two groups (p > 0.05) (Table 2).

Fig. 3.

Summary pre-and post-operative evaluation A. Range of motion B. Visual analog score C. ASES score.

Table 2.

Comparison range of motion, ASES, and VAS score between anchor and anchorless knotless suture bridge technique.

Variables	n	Anchor n = 14	Anchorless n = 13	p-value
Forward Flexion	Pre	160 (100–180)	160 (140–170)	0.864b
	Post	170 (160–180)	170 (160–180)	1.000b
Abduction	Pre	160 (80–180)	160 (120–180)	0.698b
	Post	180 (160–180)	170 (160–180)	0.282b
External Rotation	Pre	70 (45–90)	70 (30–90)	0.739b
	Post	80 (70–90)	80 (70–90)	0.410b
ASES Score	Pre	32.9 ± 11.7	28.1 ± 10.2	0.284a
	Post	91.3 ± 7.7	91.9 ± 5.9	0.835a
VAS	Pre	8 (6–9)	9 (8–10)	0.170b
	Post	1 (0–4)	1 (0–2)	0.685b

*Significance p-value<0,05.

^aUnpaired t-test.

^bMann Whitney Test.

From radiographic evaluation, we found that sagittal evaluation, to determine acromion spur existence and categorize it as acromial spur at risk based on Bigliani classification, showed that type I (70.4%), type II (25.9%), and type III (3.7%). From coronal evaluation, we found that shape of acromial spur, evaluated at Rockwood (30° caudal tilt) view, were flat (25.9%), bump type (33.3%), heel type (11.1%), keel (25.9%), and irregular (3.7%) (Table 1). Acromion spur at risk, evaluated in sagittal plane, was 3.7% in the study population. Whereas acromion spur at risk, evaluated in coronal plane, was 40.7% in the study population. There were significant differences in pre-and post-operative CSI (39.1 ± 4.3 vs 36.4 ± 4.8; p < 0.05) and AI evaluation (0.81 ± 0.13 vs 0.75 ± 0.12; p < 0.05) (Fig. 4).

Fig. 4.

Summary pre-and post-operative X- Ray evaluation A. Critical shoulder angle (CSA) B. Acromial index (AI).

3.2. Structural integrity outcome

Postoperative MRI examination of cuff integrity revealed type I (44.4%), type II (40.7%), type III (11.1%), type IV (3.7%), and type V (0%) (Fig. 5). Knotless suture bridge rotator cuff repair with medial anchor showed type I (43%), type II (36%), and type III (21%). Whereas, knotless suture bridge rotator cuff repair without medial anchor showed type I (46.1%), type II (46.1%), and type IV (8%).

Fig. 5.

Postoperative rotator cuff integrity (A) type I, sufficient thickness with homogenously low intensity; (B) type II, sufficient thickness with partial high intensity; (C) type III, insufficient thickness without discontinuity (thinned cuff); (D) type IV, presence of minor discontinuity.

3.3. Complications

There were no intraoperative or perioperative complications. No patients had neural injury, wound infection, or suture anchor problems.

4. Discussion

The important finding of this study was that in the midterm follow-up, the knotless suture bridge technique in the high grade PB-RCTs provides functional improvements and pain relief in most patients. A low rate of complications was observed. We can divide the benefits of this technique in three aspects. First, this technique shows us the advantage of articular preservation repair principle in partial tear of rotator cuff. Second, this technique repairs the rotator cuff in full layered fashion instead of bursal avulsion repair only. Third, some advantages and novelty are showed in the application of suture bridge technique without medial anchor.

The standard surgical treatment for bursal side PB-RCTs is still debatable.¹ Several literatures become proponent of the full-thickness conversion repair technique.^2,3 While several literatures, mentioning the preservation of intact articular side rotator cuff fibers for PB-RCTs, have been reported.4, 5, 6, 7, 8, 9, 10, 11, 12 Only five literatures showed us the clinical outcome and repair integrity.^2,6,8,35 There are less literature that emphasize the PB-RCTs in high grade settings (>50% partial tear). We attempted to remove the diseased tissue while preserving any intact articular fibers after sufficient bursectomy and debridement of the diseased or frayed tissue on the bursal side. We believe that in leaving the articular footprint intact, we accomplish 3 goals. First, the intact articular fibers act as an internal splint to protect the bursal-sided repair. As we knew that synovial fluid has biological substances that disrupt the soft and hard tissue healing. The intact of articular attachment act as a barrier to prevent contact those substances to the repaired bursal side area. Second, the intact articular attachment act as an anatomical landmark to the original footprints so as to recreate a wide and anatomic footprint after repairing procedure. Third, the articular preservation technique can prevent over lateralization of the repaired footprints so as to be able to minimize any length-tension mismatch that can cause re-tear.⁴

Our technique repaired the high grade PB-RCTs in the full layered fashion instead of the bursal avulsion fashion only. The purchase of full layer of rotator cuff tendon in high grade PB-RCTs have several purposes.⁶ First, it will distribute a tensile force throughout the entire tendon and reduce articular side tension. Second, it will promote tendon healing closer to original footprint. Third, it will compress the whole layer of the repaired tendon against the bone and enlarge the contact area. Fourth, it will decrease the possibility to cut through. We also do not perform medial row knot tying. The reasons are to prevent sub-acromial knot tying irritation during shoulder motion, because no suture knots are in the greater tuberosity.¹⁰ Besides that, we also believe it can prevent strangulation of the cranial (musculotendinous) to caudal (rotator cuff insertion area) vascularization.¹⁵ At the end, the configuration sutures are suture bridge with eight to twelve suture configurations in purposes to distribute pressure-tension in the wider contact surface area on the tendon to bone interface therefore it can create the firm tendon to bone stabilization, promote tendon to bone healing and prevent re-tear due to suture-tendon cut through.¹⁰ This prevention is also enhanced by the oblique direction of the sutures to the fibers of the tendon and the wider width of the suture material.

This study revealed that there is no significant difference in post-operative range of motion evaluations, functional outcome, and the cuff integrity between medial row anchor and medial row anchorless of medial knotless suture bridge technique. Nakajima et al. found that the articular side of the rotator cuff comprise of complex tendon, ligament, and capsule.¹⁶ Therefore, we can conclude that articular side is more stiff than bursal side and less able to undergo greater deformation. Inserting medial anchor become optional in the setting of preserving the articular side of the rotator cuff. This circumstance makes the repairing procedure less time consuming, less expensive, and easy to perform.

Based on this study, we also concluded that sub-acromial decompression and acromioplasty are still necessary to be performed. In coronal view shoulder radiographic evaluation, we found that 74% of study population had acromion spur and 40.7% among of them were classified as acromion spur ‘at risk’.¹³ The mean pre-operative CSI and AI were more than normal value, indicating the susceptibility to obtain sub-acromial problems. This study also revealed that sub-acromial decompression and acromioplasty could eliminate pathology of impingement so as to relieve the pain and reduce lateral extension in coronal plane evaluation.¹⁷ Similar results also were also showed with the numerous studies that reported satisfactory outcomes after acromioplasty combined with rotator cuff repair. MacDonald et al. reported outcomes similar to those of 2 previous randomized controlled trials and added that the re-operation rate was higher in the group receiving rotator cuff repair without acromioplasty.¹⁸

This study had several limitations that should be discussed. First, the retrospective instead of comparative nature of the study and relatively short follow-up times prevented us from obtaining a clear understanding of the requirements for treatment of bursal-side PTRCTs. Second, several concomitant procedures, such as acromioplasty, tenodesis, and SLAP repairs, were performed along with the rotator cuff repairs, which may have influenced the clinical results. Third, postoperative MRI scans were taken at various times between 6 and 18 months after the surgery instead of being taken at a specific time point. Thus, the structural integrity reported here may not match the clinical outcomes at the final follow-up.

5. Conclusion

Arthroscopic knotless-in situ suture bridge repair technique in PBS- RCT achieved good functional outcome and structural integrity at minimum 2 years after surgery. Insertion medial anchor on this technique was optional with evidences that similar good clinical outcome and structural integrity were obtained in medial anchor and anchorless groups.

Ethical clearance number

MTU-EC-OT-2-209/60.

Funding

The authors have not declared a specific grant for his research from any funding agency in the public, commercial, or non-profit sector.

Declaration of competing interest

No competing interest declared.