Arthroscopic double-row repair of the rotator cuff: a comparison of bio-absorbable and non-resorbable anchors regarding osseous reaction

Clinical and radiological outcome after arthroscopic rotator cuff repair using PEEK-CF anchors

PURPOSE

The goal of this study was to evaluate the clinical and radiological outcome after arthroscopic rotator cuff repair using new carbonfiber reinforced polyetheretherketone (CF-PEEK) suture anchors.

METHODS

One hundred (n=100) patients with rotator cuff tears were enrolled at seven French hospitals between July 2019 and June 2020. Pain levels, Constant score and Subjective Shoulder Value (SSV) were taken preoperatively and 6months postoperatively. Ultrasonography (US) was performed at 6months postoperatively to evaluate tendon healing using the Sugaya classification. Statistical analysis was done with the Student t-test with 95% confidence intervals.

RESULTS

One hundred patients of the 100 patients were followed at 6months. The mean SSV and Constant score improved from 40.1% preoperatively to 78% at 6months (p<0.0001) and from 43 points preoperatively to 65 points at 6months (p<0.0001), respectively. The mean level of pain, as measured with the visual analogue scale, decreased from 5.9 to 1.6 (p<0.001). There were no postoperative complications that resulted in revision surgery.

CONCLUSION

The study showed good results at 6months follow-up using carbonfiber reinforced PEEK anchors with improved Constant and SSV scores as well as a high ultrasonographic tendon healing rate, making PEEK-CF anchors safe to use, comparable to commonly used anchors.

LEVEL OF EVIDENCE

IV.

Soft Anchors for Rotator Cuff Repair: A Review

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All-suture anchors or so-called "soft" anchors, initially adapted for labral repairs, have increased in popularity for use in rotator cuff repair because of their smaller size, decreased occupation of the footprint, improved points of fixation, ease of use, and ease of revision.

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In limited series, soft anchors have demonstrated equivalent biomechanical and clinical performance compared with hard body anchors for rotator cuff repair.

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Perianchor cyst formation can occur with both hard body and soft anchors.

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Biomechanical and clinical data support aiming for vertical angles of insertion for soft anchors.

Can the Single Assessment Numeric Evaluation be used as a stand-alone subjective outcome instrument in patients undergoing rotator cuff repair?

BACKGROUND/HYPOTHESIS

There is no consensus to which patient-determined shoulder outcome scores should be considered when analyzing patient outcomes. Use of multiple patient-determined outcomes may be redundant and cause increased responder burden. The Single Assessment Numeric (SANE) has not been widely accepted as a stand-alone shoulder-specific outcome measure. The hypothesis was that SANE will correlate with and be comparable in responsiveness to other subjective outcome measures that have been used in a stand-alone fashion in patients undergoing rotator cuff repair (American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form [ASES], Western Ontario Rotator Cuff Index [WORC], and the Simple Shoulder Test [SST]). In addition, the SANE will be more relevant to each patient compared to the ASES, further supporting its use as a stand-alone shoulder-specific outcomes measure.

METHODS

A retrospective review of a database of patients undergoing rotator cuff repair was reviewed where the SANE was recorded with the ASES, WORC, and/or SST. Correlations were determined using the Pearson coefficient. Subgroup analysis was performed to determine if correlations differed in (1) preoperative and (2) postoperative outcome determinations. Responsiveness was determined by calculating the standardized response mean (SRM) and the effect size (ES) of all scores. Relevance and precision of the SANE and ASES were examined using 150 consecutive patients to determine the number of questions in each score that were not answered.

RESULTS

Correlation was excellent for the SANE and the ASES (n = 1838, r = 0.81, P < .0001), the WORC (n = 1793, r = 0.82, P < .0001), and the SST (n = 1836, r = 0.76, P < .0001). Correlation of preoperative scores was moderate and postoperative scores were excellent when comparing the SANE with all 3 scores. All scores were highly responsive, with the SRM of the SANE = 2.1, ASES = 2.2, WORC = 2.4, and the SST = 1.8. The ES of the SANE = 2.4, ASES = 2.7, WORC = 3.0, and the SST = 2.1. One hundred percent of the SANE scores were answered completely compared with 57% (P < .0001) of the ASES, with significant variability found in the answers to the "work" and "score" questions.

CONCLUSION

In patients undergoing rotator cuff repair, the SANE highly correlated and has equivalent responsiveness with the WORC, ASES, and SST, which have been used as stand-alone shoulder-specific outcomes measures. The SANE may provide the same information as the WORC, ASES, and SST regarding outcome with significant reduction in responder burden. This study supports that the SANE can be used as a subjective, stand-alone instrument for patients undergoing rotator cuff repair.

Risk Factors and Corresponding Management for Suture Anchor Pullout during Arthroscopic Rotator Cuff Repair

INTRODUCTION

Due to the aging of the population, the incidence of rotator cuff tears is growing. For rotator cuff repair, arthroscopic suture-anchor repair has gradually replaced open transosseous repair, so suture anchors are now considered increasingly important in rotator cuff tear reconstruction. There are some but limited studies of suture anchor pullout after arthroscopic rotator cuff repair. However, there is no body of knowledge in this area, which makes it difficult for clinicians to predict the risk of anchor pullout comprehensively and manage it accordingly.

METHODS

The literature search included rotator cuff repair as well as anchor pullout strength. A review of the literature was performed including all articles published in PubMed until September 2021. Articles of all in vitro biomechanical and clinical trial levels in English were included. After assessing all abstracts (n = 275), the full text and the bibliographies of the relevant articles were analyzed for the questions posed (n = 80). Articles including outcomes without the area of interest were excluded (n = 22). The final literature research revealed 58 relevant articles. Narrative synthesis was undertaken to bring together the findings from studies included in this review.

RESULT

Based on the presented studies, the overall incidence of anchor pullout is not low, and the incidence of intraoperative anchor pullout is slightly higher than in the early postoperative period. The risk factors for anchor pullout are mainly related to bone quality, insertion depth, insertion angle, size of rotator cuff tear, preoperative corticosteroid injections, anchor design, the materials used to produce anchors, etc. In response to the above issues, we have introduced and evaluated management techniques. They include changing the implant site of anchors, cement augmentation for suture anchors, increasing the number of suture limbs, using all-suture anchors, using an arthroscopic transosseous knotless anchor, the Buddy anchor technique, Steinmann pin anchoring, and transosseous suture repair technology.

DISCUSSION

However, not many of the management techniques have been widely used in clinical practice. Most of them come from in vitro biomechanical studies, so in vivo randomized controlled trials with larger sample sizes are needed to see if they can help patients in the long run.

Perianchor Cyst Formation Is Similar Between All-Suture and Conventional Suture Anchors Used for Arthroscopic Rotator Cuff Repair in the Same Shoulder

Purpose

The purpose of this study was to compare perianchor cyst formation between soft and hard suture anchors placed in the same patient 1 year after arthroscopic rotator cuff repair (ARCR).

Methods

This study reviewed patients who underwent primary ARCR using a “hybrid” technique using at least one soft anchor (FiberTak, Arthrex, Naples, FL) and one hard anchor (SwiveLock) placed in the same shoulder between January 1, 2018 and December 31, 2018. Magnetic resonance imaging was obtained at minimum 1-year postoperative to assess cyst formation (perianchor fluid signal) and rotator cuff healing. Range of motion (ROM) and patient-reported outcome measures (PROMs) were evaluated at baseline and 1-year follow up. PROMs included visual analog scale pain score, Simple Shoulder Test score, American Shoulder and Elbow Surgeon (ASES) score.

Results

Nineteen patients with a combined 45 hard and 26 soft suture anchors were available for follow-up at a mean of 20 months postoperatively. There was a higher proportion of grade 1 fluid signal changes in the hard anchor group compared to the soft group (62.2% to 7.7; P < .001); however, there was no difference in the incidence of cyst formation (grade 2 or 3 changes) between groups (13.3% vs 3.8%; P = .251). There was also no difference in the rate of cyst formation between biocomposite and polyether-ether-ketone-type hard anchors (18.2% vs 0%; P = .113) or between anchors placed at the greater and lesser tuberosities (10.2% vs 5.3%, P = .519).

Conclusion

Hard suture anchors showed increased fluid signal compared to soft suture anchors at short-term follow-up after ARCR, but there was no difference in cyst formation between anchor types.

Biomechanical properties of a suture anchor system from human allogenic mineralized cortical bone matrix for rotator cuff repair

Background

Suture anchors (SAs) made of human allogenic mineralized cortical bone matrix are among the newest developments in orthopaedic and trauma surgery. Biomechanical properties of an allogenic mineralized suture anchor (AMSA) are not investigated until now. The primary objective was the biomechanical investigation of AMSA and comparing it to a metallic suture anchor (MSA) and a bioabsorbable suture anchor (BSA) placed at the greater tuberosity of the humeral head of cadaver humeri. Additionally, we assessed the biomechanical properties of the SAs with bone microarchitecture parameters.

Methods

First, bone microarchitecture of 12 fresh frozen human cadaver humeri from six donors was analyzed by high-resolution peripheral quantitative computed tomography. In total, 18 AMSAs, 9 MSAs, and 9 BSAs were implanted at a 60° angle. All three SA systems were systematically implanted alternating in three positions within the greater tuberosity (position 1: anterior, position 2: central, position 3: posterior) with a distance of 15 mm to each other. Biomechanical load to failure was measured in a uniaxial direction at 135°.

Results

Mean age of all specimens was 53.6 ± 9.1 years. For all bone microarchitecture measurements, linear regression slope estimates were negative which implies decreasing values with increasing age of specimens. Positioning of all three SA systems at the greater tuberosity was equally distributed (p = 0.827). Mean load to failure rates were higher for AMSA compared to MSA and BSA without reaching statistical significance between the groups (p = 0.427). Anchor displacement was comparable for all three SA systems, while there were significant differences regarding failure mode between all three SA systems (p < 0.001). Maximum load to failure was reached in all cases for AMSA, in 44.4% for MSA, and in 55.6% for BSA. Suture tear was observed in 55.6% for MSA and in 22.2% for BSA. Anchor breakage was solely seen for BSA (22.2%). No correlations were observed between bone microarchitecture parameters and load to failure rates of all three suture anchor systems.

Conclusions

The AMSA showed promising biomechanical properties for initial fixation strength for RCR. Since reduced BMD is an important issue for patients with chronic rotator cuff lesions, the AMSA is an interesting alternative to MSA and BSA. Also, the AMSA could improve healing of the enthesis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05371-0.

Are Knotted or Knotless Techniques Better for Reconstruction of Full-Thickness Tears of the Superior Portion of the Subscapularis Tendon? A Study in Cadavers

BACKGROUND

Knotted and knotless single-anchor reconstruction techniques are frequently performed to reconstruct full-thickness tears of the upper portion of subscapularis tendon. However, it is unclear whether one technique is superior to the other.

QUESTIONS/PURPOSES

(1) When comparing knotless and knotted single-anchor reconstruction techniques in full-thickness tears of the upper subscapularis tendon, is there a difference in stiffness under cyclic load? (2) Are there differences in cyclic gapping between knotless and knotted reconstructions? (3) Are there differences in the maximal stiffness, yield load, and ultimate load to failure? (4) What are the modes of failure of knotless and knotted reconstruction techniques?

METHODS

Eight matched pairs of human cadaveric shoulders were dissected, and a full-thickness tear of the subscapularis tendon (Grade 3 according to the Fox and Romeo classification) was created. The cadavers all were male specimens, with a median (range) age of 69 years (61 to 75). Before biomechanical evaluation, the specimens were randomized into two equal reconstruction groups: knotless single anchor and knotted single anchor. All surgical procedures were performed by a single orthopaedic surgeon who subspecializes in sports orthopedics and shoulder surgery. With a customized set up that was integrated in a dynamic material testing machine, the humeri were consecutively loaded from 10 N to 60 N, from 10 N to 100 N, and from 10 N to 180 N for 50 cycles. Furthermore, the gapping behavior of the tear was analyzed using a video tracking system. Finally, the stiffness, gapping, maximal stiffness, yield loads, and maximum failure loads of both reconstruction groups were statistically analyzed. Failure was defined as retearing of the reconstructed gap threshold due to rupture of the tendon and/or failure of the knots or anchors. After biomechanical testing, bone quality was measured at the footprint of the subscapularis using microCT in all specimens. Bone quality was equal between both groups. To detect a minimum 0.15-mm difference in gap formation between the two repair techniques (with a 5% level of significance; α = 0.05), eight matched pairs (n = 16 in total) were calculated as necessary to achieve a power of at least 90%.

RESULTS

The first study question can be answered as follows: for stiffness under cyclic load, there were no differences with the numbers available between the knotted and knotless groups at load stages of 10 N to 60 N (32.7 ± 3.5 N/mm versus 34.2 ± 5.6 N/mm, mean difference 1.5 N/mm [95% CI -6.43 to 3.33]; p = 0.55), 10 N to 100 N (45.0 ± 4.8 N/mm versus 45.2 ± 6.0 N/mm, mean difference 0.2 N/mm [95% CI -5.74 to 6.04]; p = 0.95), and 10 N to 180 N (58.2 ± 10.6 N/mm versus 55.2 ± 4.7 N/mm, mean difference 3 N/mm [95% CI -5.84 to 11.79]; p = 0.48). In relation to the second research question, the following results emerged: For cyclic gapping, there were no differences between the knotted and knotless groups at any load levels. The present study was able to show the following with regard to the third research question: Between knotted and knotless repairs, there were no differences in maximal load stiffness (45.3 ± 8.6 N/mm versus 43.5 ± 10.2 N/mm, mean difference 1.8 [95% CI -11.78 to 8.23]; p = 0.71), yield load (425.1 ± 251.4 N versus 379.0 ± 169.4 N, mean difference 46.1 [95% CI -276.02 to 183.72]; p = 0.67), and failure load (521.1 ± 266.2 N versus 475.8 ± 183.3 N, mean difference 45.3 [95% CI -290.42 to 199.79]; p = 0.69). Regarding the fourth question concerning the failure modes, in the knotted repairs, the anchor tore from the bone in 2 of 8, the suture tore from the tendon in 6 of 8, and no suture slipped from the eyelet; in the knotless repairs, the anchor tore from the bone in 2 of 8, the suture tore from the tendon in 3 of 8, and the threads slipped from the eyelet in 3 of 8.

CONCLUSION

With the numbers available, we found no differences between single-anchor knotless and knotted reconstruction techniques used to repair full-thickness tears of the upper portion of subscapularis tendon.

CLINICAL RELEVANCE

The reconstruction techniques we analyzed showed no differences in terms of their primary stability and biomechanical properties at the time of initial repair and with the numbers available. In view of these experimental results, it would be useful to conduct a clinical study in the future to verify the translationality of the experimental data of the present study.

Periimplant osteolysis does not affect the outcome of rotator cuff repair: a systematic review and meta-analysis

PURPOSE

The goal of this study was to perform a systematic review and meta-analysis to compare the clinical and radiologic outcomes of rotator cuff repair, depending on the presence of developed periimplant osteolysis (PIO) after using suture anchors.

METHODS

The electronic databases of MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched for articles published up until October 2019 to find relevant articles comparing the outcomes of rotator cuff repair between the periimplant osteolysis group and non-periimplant osteolysis group. Data searching, extraction, analysis, and quality assessment were performed according to the Cochrane Collaboration guidelines. The results are presented as risk ratio (RR) for binary outcomes and standardised mean difference (SMD) for continuous outcomes with 95% confidence intervals (CI).

RESULTS

Six clinical studies were included. No significant differences were found between the group with periimplant osteolysis and the group without periimplant osteolysis regarding retear rate (RR = 1.34; 95% CI 0.93-1.94; I² = 28%), postoperative clinical scores (SMD = 0.29; 95% CI - 0.26 to 0.83; I² = 80%) and range of motion (ROM); forward flexion (SMD = 0.39; 95% CI - 0.16 to 0.93; I² = 0%), external rotation (SMD = - 0.10; 95% CI - 0.64 to 0.45; I² = 0%) and internal rotation (SMD = - 0.37; 95% CI - 0.92 to 0.17; I² = 0%).

CONCLUSION

The presence of periimplant osteolysis after rotator cuff repair with suture anchor does not affect the clinical outcomes such as retear rate, clinical scoring, and ROM. However, as there was no standard consensus on the criteria for evaluating periimplant osteolysis, this result may not fully reflect the effect of periimplant osteolysis depending on its severity.

LEVEL OF EVIDENCE

Level IV.

Long-term follow-up of perianchor cyst formation after rotator cuff repair

Background

Perianchor cyst formation (PCF) can occur after arthroscopic rotator cuff repair with poly-L-lactic acid (PLLA) anchors; however, little is known about PCF after all-suture anchor (ASA) use.

Methods

We reviewed patients who underwent double-row arthroscopic rotator cuff repair from 2012 to 2017 with ASAs implanted in the medial row and PLLA anchors in the lateral row. We evaluated PCF (graded on magnetic resonance imaging) and compared physical examination and functional surveys between patients with PCF (WC) and without PCF (WoC) at long-term follow-up.

Results

Among twenty-two patients (23 shoulders), 93% of PLLA anchors (vs. 79% ASA) displayed a grade 0 PCF, P = .100. No PLLA anchors had a grade 3 or 4 PCF, compared to 11% of ASAs, P = .158. At a mean postoperative follow-up time of 113 weeks, there was no significant difference between WC and WoC cohorts with regard to range of motion, rotator cuff strength, American Shoulder and Elbow Surgeons survey scores, or retear rates. However, the WoC cohort had a significantly higher University of California at Los Angeles shoulder survey score at final follow-up (34.3 WoC vs. 30.9 WC, P = .024).

Conclusion

No difference was found in PCF between ASAs and PLLA anchors. At long-term follow-up, WoC patients had significantly improved functional outcome scores, based on the University of California at Los Angeles survey, but equivalent range of motion and rotator cuff strength examinations compared with WC patients.

Protocol for a Retrospective Comparative Study to Determine the Effect of Two Different Biocomposite Suture Anchors on the Occurrence of Bony Ingrowth and Implant Reabsorption Following Arthroscopic Rotator Cuff Repair

Introduction

Surgical treatment of rotator cuff tears commonly entails reattachment of the ruptured tendon to its bony insertion using suture anchors. Suture anchor design has evolved from solid metal anchors to vented biocomposite anchors with potentially biologic consequences. Few studies have investigated the differences between different modern anchor design and materials, making it difficult to justify their use or cost.

Objective

To compare the rate of bony ingrowth and implant resorption between a coil-type open-architecture biocomposite suture anchor and a vented screw-type biocomposite suture anchor, used for arthroscopic double-row rotator cuff repair.

Methods and analysis

In this retrospective comparative study, a consecutive series of patients who undergo a double row rotator cuff repair using a coil-type open architecture biocomposite suture anchor in the medial row and a vented screw-type biocomposite suture anchor in the lateral row will be included. A sample size calculation demonstrated that 16 participants are required in each group. Primary outcome measures will be bony ingrowth and reabsorption of the suture anchor as measured on computed tomography (CT). Secondary outcomes will include patient reported outcome measures (The American Shoulder and Elbow Surgeons score and The Western Ontario Rotator Cuff questionnaire), range of motion, postoperative tendon integrity, and cyst formation.

Highlights

Open-architecture suture anchors facilitate the release of marrow constituents.The rate of bony ingrowth for coil- and screw-type anchors will be assessed.The difference in functional outcome between the two anchors will be assessed.

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

BACKGROUND

Commercially available suture anchors for rotator cuff repairs can differ significantly in architecture and material. Clinical data on their osseous integration and its effect on patient-reported outcomes is scarce. Preclinical investigations indicated a higher rate of osseous integration for the open-architecture design of the Healicoil Regenesorb anchor than the closed-threaded design of the Twinfix (Smith & Nephew). The purpose of this study was to investigate these 2 anchors with different architecture and material to determine their effect on osseous integration and clinical outcomes after rotator cuff repair.

METHODS

A prospective randomized controlled trial was performed from 2014 to 2019. Sixty-four patients (39 females, 25 males) with an average age of 58.7 years who underwent arthroscopic rotator cuff repair by one of 4 board-certified, fellowship-trained surgeons were randomized to receive Healicoil Regenesorb (PLGA/ß-TCP/Calcium Sulfate) or Twinfix Ultra HA (PLLA/HA) anchors. Thirty-two patients had Healicoil anchors implanted, and 32 patients had Twinfix anchors implanted. Of the 64 patients, 51 returned at 24 months for computed tomographic (CT) examination (25 Twinfix and 26 Healicoil) to determine osteointegration of the anchors. Patient-reported outcomes, including Penn Shoulder Score (PENN), Western Ontario Rotator Cuff Index, visual analog scale, EQ-5D, Single Assessment Numeric Evaluation, Global Rating of Change, were collected at baseline, 6 weeks, 3 months, 6 months, 12 months, and 24 months. Ultrasonography was used to assess rotator cuff integrity after 6 months. Two board-certified, fellowship-trained orthopedic surgeons, blinded to the type of anchors, analyzed the CT scans to assess the anchor osteointegration at 24 months using a previously published grading scale.

RESULTS

There were no differences in demographics, preoperative outcomes, or baseline characteristics such as tear size, number of anchors, Goutallier classification, or smoking status between groups. There was no difference in osseous integration between the 2 anchors at 24 months (P = .117). Eight patients had rotator cuff retears, of which 2 patients had Twinfix anchors and 6 patients had Healicoil anchors (P = .18). There were no statistically significant differences in patient-reported outcomes or complications between groups. The 2-year PENN scores were 89 with the Twinfix and 88 with Healicoil anchors (P = .55).

CONCLUSION

Despite differences in material and anchor architecture, the rate of healing and patient-reported outcomes were similar between the Twinfix and Healicoil anchor groups. The rate of osteointegration was the same at 2 years.

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

PURPOSE

To assess the natural evolution of the osseous reaction following arthroscopic double-row rotator cuff repair with PEEK anchors and to analyze its correlation with clinical shoulder function.

METHODS

Between 2015 and 2017, 159 patients received arthroscopic double-row rotator cuff repair with PEEK anchors and underwent serial clinical and radiological follow-up (3, 6, 12, and 24 months). Radiological results were analyzed by tendon integrity, bone marrow edema, and peri-implant osteolysis. Clinical shoulder function was evaluated with the Constant score.

RESULTS

One-hundred and seventeen patients were enrolled; among them, 63% demonstrated bone marrow edema around the anchors on postoperative 3-month MRI. The edema area percentage was 41% ± 7%. At 6 months, edema was only seen in 12% of cases, with an area percentage of 18% ± 5%. At 12 and 24 months, edema was rarely present. Fluid signals around the anchor were observed in 17.6%, 42.7%, 33.3%, and 21.0% of patients at 3, 6, 12, and 24 months, respectively; the tunnel widening values were 1.1 ± 0.4 mm, 1.8 ± 0.5 mm, 2.3 ± 0.6 mm, and 2.2 ± 0.7 mm at each follow-up, respectively. The sign of osteolysis was significantly more obvious around the lateral anchor than around the medial anchor. The presence of an osseous reaction was not correlated with worse clinical outcome.

CONCLUSION

Osseous reactions following arthroscopic rotator cuff repair are common and significant even with PEEK anchors. Bone marrow edema does not last more than 6 months in patients without complications. Peri-implant osteolysis is more evident around the lateral anchor than around the medial anchor and improves gradually over time. The sign of osteolysis is not correlated with clinical shoulder function. Based on these findings, surgeons should be cautious about bone marrow edema lasting more than 6 months following arthroscopic rotator cuff repair.

LEVEL OF EVIDENCE

Level IV.

Clinical and Radiologic Outcomes of Combined Use of Biocomposite and PEEK Suture Anchors during Arthroscopic Rotator Cuff Repair: A Prospective Observational Study

The aim of the current study was to evaluate the functional and radiologic outcomes of biocompatible non-absorbable PEEK (polyetheretherketone) and biocomposite (poly-L-lactic acid/poly(lactic-co-glycolic acid) 70% + β-tricalcium phosphate) anchors, especially in terms of perianchor cyst formation during the first six months postoperatively. We prospectively analysed 29 patients who underwent arthroscopic rotator cuff repair between March and May 2019. Both PEEK and biocomposite suture anchors were used as lateral anchors in one body. Clinical outcomes were assessed using the shoulder range of motion (ROM), visual analogue scale (VAS) for pain and satisfactory score, American Shoulder and Elbow Surgeons (ASES) score, and Simple Shoulder Test (SST). All these were obtained in patients preoperatively at 3 and 6 months after surgery. The imaging evaluation included perianchor cyst formation, anchor absorption, repaired cuff integrity, and retear pattern. All functional outcomes significantly improved over time. The biocomposite anchor had a statistically significant tendency to form higher grades of fluid collection at 3 months after surgery. However, the perianchor cyst reduced by the sixth postoperative month. Six months postoperatively, the functional outcomes were improved after rotator cuff repair and similar degrees of perianchor cyst formation were observed, regardless of the suture anchor material used.

Contribution of postoperative ultrasound to early detection of anchor pullout after rotator cuff tendon repair: Report of 3 cases

INTRODUCTION

Rotator cuff repair by suture bridge is now widely used. Few studies reported secondary pullout of radiotransparent anchors. The aim of the present prospective study was to demonstrate the contribution of in-office ultrasonography to detect pullout, and to describe the examination procedure.

MATERIAL AND METHOD

A total of 102 patients underwent arthroscopic rotator cuff repair by suture bridge, with impacted second-row anchors. Ultrasonography was performed by the surgeon in postoperative consultations.

RESULTS

At 6 weeks' follow-up, 3 patients showed mean 2nd-row implant pullout of 8.3mm. All underwent arthroscopic revision to extract the implant, which was mobile within its tunnel in all cases. Clinical progression was good, with mean Constant score 72 and no aggravation of the lesion on ultrasound at 3 months' follow-up.

DISCUSSION

The present series would seem to be the first to report: early radiotransparent in-vivo pullout 6 weeks after suture bridge cuff repair; ultrasound detection of pullout in consultation by the orthopedic surgeon; a description of the ultrasound technique for screening this rare and specific problem.

CONCLUSION

Ultrasound now enables radiotransparent anchor positioning to be monitored following rotator cuff repair as of the first postoperative days, without compromising tendon healing.

LEVEL OF EVIDENCE

II.

The formation of perianchor fluid associated with various suture anchors used in rotator cuff repair

Aims

The aim of this study was to compare the osseous reactions elicited by all-suture, polyetheretherketone (PEEK), and two different biodegradable anchors used during rotator cuff repair.

Patients and Methods

Transosseous-equivalent rotator cuff repair was performed in 73 patients. The patients were divided into two groups, in both of which two different medial-row anchors were used. In group 1, anchor A comprised 30% β-tricalcium phosphate (TCP) + 70% fast-absorbing poly lactic-co-glycolic acid copolymer (85% polylactic acid enantiomers + 15% polyglycolic acid) and anchor B comprised all-sutures. In group 2, anchor C comprised 23% micro β-TCP + 77% polylactic acid enantiomers and anchor D comprised PEEK polymer. There were 37 patients in group 1 and 36 patients in group 2. The presence and severity of fluid collection around anchors and healing of the rotator cuff were assessed using MRI scans, approximately one year postoperatively. The severity of the collection was graded as 0 (no perianchor fluid signal), 1 (minimal perianchor fluid), 2 (local collection of fluid), 3 (fluid collection around the whole length of the anchor but of a diameter less than twice the anchor diameter), or 4 (fluid collection around the whole length of the anchor and of a diameter greater than twice the anchor diameter).

Results

A perianchor fluid signal was seen in three patients (8.1%) with anchor A, four (10.8%) with anchor B, 15 (41.7%) with anchor C, and 15 (41.7%) with anchor D. The severity of the collection around anchor was grade 2:1:0:0 for anchor A, grade 2:2:0:0 for anchor B, grade 12:2:0:1 for anchor C, and grade 11:3:0:1 for anchor D (grade 1:2:3:4, respectively). The prevalence and severity of fluid formation was not significantly different between anchors A and B, and anchors C and D. However, on intergroup analysis, there were significant differences for the prevalence and severity of fluid formation between anchors in group 1 and group 2. The prevalence of failure to heal was not significant in group 1 (seven, 18.9%) or group 2 (nine, 25.0%). There was no relationship between the presence of perianchor fluid and each type of anchor, and the integrity of the rotator cuff repair, in either group.

Conclusion

Despite the nonabsorbable nature of all-suture and PEEK anchors, all-suture anchors produced less osseous reaction after rotator cuff repair. In deciding which kind of anchor to use, consideration should be given not only to the strength of the initial fixation, but also to the postoperative biological reaction. Cite this article: Bone Joint J 2019;101-B:1506–1511

All-Suture Anchor Settling After Arthroscopic Repair of Small and Medium Rotator Cuff Tears

BACKGROUND

All-suture anchors are increasingly being used in rotator cuff repair. However, there are debates on the micromotion of all-suture anchors.

PURPOSE

To perform rotator cuff repair on patients with rotator cuff tears and different shoulder bone mineral densities (BMDs) and investigate (1) where the anchor is located under the cortex, (2) if there is any anchor migration settling during follow-up, and (3) if structural outcome differs according to shoulder BMD.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

We retrospectively investigated 88 patients who underwent arthroscopic single-row repair for small- to medium-sized rotator cuff tears (age [mean ± SD], 58.8 ± 7.1 years) from 712 cases of rotator cuff tendon repair between November 2015 and February 2018. Inclusion criteria were as follows: use of an all-suture anchor; preoperative shoulder BMD; and magnetic resonance imaging (MRI) conducted preoperatively, 2 days after surgery, and 10 months after surgery. Patients were excluded from the study if they underwent open rotator cuff repair (n = 118), got surgery with a double-row technique (n = 178), underwent surgery with anchors other than the all-suture type (n = 273), received anchor insertion in sites other than the greater tuberosity owing to concomitant procedures such as biceps tenodesis and subscapularis repair (n = 29), did not take preoperative shoulder BMD (n = 15), had more than a large-size tear (n = 6), and were lost to follow-up (n = 5). After compression of the all-suture anchor during surgery, the strands were pulled multiple times to ensure that the anchor was fixed onto the bone with appropriate tension. BMD was measured before surgery. Depth to anchor (DA), anchor settling, and repaired rotator cuff integrity were measured with MRI. Patients were categorized into 3 groups: group A (BMD, <0.4 g/cm²; n = 31), group B (BMD, 0.4-0.6 g/cm²; n = 32), and group C (BMD, >0.6 g/cm²; n = 25). A total of 65 patients had follow-up MRI. On the basis of rotator cuff tendon integrity, patients were categorized into either a sufficient thickness group (group S, Sugaya classification grade II or lower; n = 44) or an insufficient thickness group (group I, Sugaya classification grade III or higher; n = 21).

RESULTS

On time-zero MRI, the DA differed significantly among groups (group A, 3.62 ± 2.02 mm; group B, 5.18 ± 2.13 mm; group C, 6.30 ± 3.34 mm) (P = .001). The DA was deeper in patients with a higher BMD at time zero (r = 0.374; P = .001), but the DA did not differ at follow-up MRI (mean, 10.3 months after surgery). On follow-up MRI, anchor settling tended to increase with deeper time-zero DA (r = 0.769; P < .001). Anchor settling was significantly different among groups (group A, 1.33 ± 1.08 mm; group B, 2.78 ± 1.99 mm; group C, 3.81 ± 2.19 mm) (P = .001). The proportion of patients with sufficient thickness in each group did not show a statistical difference (group A, 70.8%; group B, 72.7%; group C, 57.9%) (P = .550).

CONCLUSION

In conclusion, this study confirmed that the postoperative site of anchor insertion in arthroscopic single-row rotator cuff repair with all-suture anchors was located farther from the cortex in patients with higher shoulder BMD and closer to the subcortical bone in patients with lower BMD. On follow-up MRI, no further settling occurred past a certain distance from the cortex, and there was no significant difference in anchor depth or integrity of the rotator cuff tendon based on shoulder BMD. Therefore, minimal settling in the all-suture anchor did not show clinical significance.

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

PURPOSE

This study aimed to identify the difference in postoperative perianchor bone reactions in different groups of patients who underwent rotator cuff tear repairs with all-suture-, bioabsorbable screw-, and PEEK (polyether ether ketone)-type suture anchors. Furthermore, the rate of rotator cuff retear and its association with perianchor bone reactions based on the different anchors used were investigated. Moreover, their impact on the clinical outcome of patients was examined.

METHODS

The study included 213 patients who underwent arthroscopic single-row repair and were divided into 3 groups according to the suture anchor used: all-suture (n = 137), biodegradable (n = 36), and PEEK (n = 40) anchor groups. The clinical outcomes and magnetic resonance imaging findings were evaluated at a mean follow-up of 9.6 months. The perianchor bone reaction at the anchor site was categorized according to grades. Patients were classified based on repair integrity into the healed and retear groups with Sugaya type I to III and Sugaya type IV to V, respectively.

RESULTS

No statistically significant differences in Constant scores and retear rates were observed between the groups (P = .934 and P = .548, respectively). Magnetic resonance imaging showed that the total number of perianchor cysts formed postoperatively was 23 (10.8% [23 of 213 patients]). Moreover, the proportions of perianchor cysts were 8.8%, 16.7%, and 12.5% in the all-suture-type, bioabsorbable-, and PEEK-type anchor groups, respectively (P = .485). In the retear group, the incidence rate was significantly increased with higher grades of perianchor bone reaction (P = .001). The tear size and perianchor bone reaction were found to be independent factors that affected the incidence of retear.

CONCLUSIONS

Perianchor cyst formation was observed in 10.8% of cases after the use of suture anchors for arthroscopic rotator cuff repair. No significant differences were observed among all-suture-type, bioabsorbable-type, and PEEK-type anchors in terms of visual analog scale and Constant scores, retear rates, and perianchor bone reactions. However, the retear rate was associated with a greater perianchor cystic reaction and larger tear size.

LEVEL OF EVIDENCE

Level III, retrospective comparative trial.

Biocomposite Suture Anchors Remain Visible Two Years After Rotator Cuff Repair

BACKGROUND

Biocomposite suture anchors containing osteoconductive materials have gained popularity in rotator cuff repairs. However, little is known about the influence of the addition of osteoconductive materials on implant resorption, bone reaction, tendon healing, and clinical outcomes scores.

QUESTIONS/PURPOSES

(1) What percentage of suture anchors were not completely resorbed 2 years after implantation? (2) What are the diameters of the bone bed in relation to the implant? (3) Is tendon integrity correlated with bone tunnel diameter? (4) Is there an association between tunnel widening, periimplant fluid film grade, biodegradation grade, and retear with clinical outcomes scores, such as the Western Ontario Rotator Cuff Index (WORC) and the Oxford Shoulder Score (OSS)?

METHODS

Thirty-six patients were enrolled from August 2012 to January 2014. The following inclusion criteria were applied: (1) reparable full-thickness supraspinatus tendon tears, (2) double-row suture bridge techniques applied for supraspinatus repair, (3) use of biocomposites suture anchor implants composed of poly L-lactic acid (PLLA) and β-tricalcium phosphate (TCP) exclusively, and (4) a minimum of 2 years followup. Four patients met the exclusion criteria, and seven of 36 patients (19%) were lost to followup. Thereby, 25 patients (84 implants) were included in this retrospective study. To answer the study's questions, the following methods were applied: (1) The resorption of the implants and periimplant fluid film were assessed on MRI using a four-stage scale system, (2) bone bed diameter was measured on MRI at three different points on the longitudinal central axis of each anchor, (3) tendon integrity was evaluated on MRI according to the Sugaya classification and correlated to bone tunnel diameter, and (4) assessed tunnel diameters, periimplant fluid film grade, biodegradation grade, and tendon condition were related to clinical outcomes scores at the time of followup (2.3 ± 0.3 years). The intraobserver reliability was 0.981 (p < 0.001) and interobserver reliability was 0.895 (p < 0.001).

RESULTS

At 2.3 ± 0.3 years, most analyzed suture anchors (76 of 84 [90%]) were, with varying degrees of degradation, still visible. Bone tunnels showed minor widening (0.4 ± 1.4 mm) at the base, but osseous ingrowth was detected as narrowing at the middle (0.1 ± 1.1 mm) and at the apex (1.4 ± 1.7 mm) of the implants. Patients with retears (Sugaya Grades 4-5) had narrower tunnels (3.6 ± 1.8 mm) than patients without retears (Sugaya Grades 1-3; 4.4 ± 1.6 mm; mean difference, 0.782 [95% confidence interval {CI}: 0.009-1.6]; p = 0.050). WORC and Oxford scores were not associated with the tunnel widening amount, fluid film grade, biodegradation grade, or tendon retear.

CONCLUSIONS

In light of the results of the present study, surgeons should consider in their daily practice that the resorption process of these implants may be slower than assumed so far, but no association with severe implant-related complications has been found in the short term. Future studies should focus on the evaluation of the effects of osteoconductive materials on resorption, tendon healing, and clinical outcomes in the long term and on the integration process in different rotator cuff reconstruction techniques.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Does Medial-Row Fixation Technique Affect the Retear Rate and Functional Outcomes After Double-Row Transosseous-Equivalent Rotator Cuff Repair?

Background:

Double-row transosseous-equivalent (TOE) rotator cuff repair techniques have been widely accepted because of their superior biomechanical properties when compared with arthroscopic single-row repair. Concerns regarding repair overtensioning with medial-row knot tying have led to increased interest in knotless repair techniques; however, there is a paucity of clinical data to guide the choice of technique.

Hypothesis:

Arthroscopic TOE repair techniques using knotless medial-row fixation will demonstrate lower retear rates and greater improvements in the Constant score relative to conventional knot-tying TOE techniques.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

A systematic review of 3 databases (PubMed, Cochrane, and Embase) was performed using PRISMA (Preferred Reporting Items for Systematic Meta-Analyses) guidelines. Inclusion criteria were English-language studies that examined repair integrity or Constant scores after arthroscopic rotator cuff repair with TOE techniques. Two investigators independently screened results for relevant articles. Data regarding the study design, surgical technique, retear rate, and Constant shoulder score were extracted from eligible studies. A quality assessment of all articles was performed using the Methodological Index for Non-Randomized Studies (MINORS) criteria.

Results:

The systematic review identified a total of 32 studies (level of evidence, 1-4) that met inclusion and exclusion criteria. Of the 32 studies, 5 reported on knotless TOE techniques, 25 reported on knot-tying TOE techniques, and 2 reported on both. In the knotless group, retear rates ranged from 6% to 36%, and Constant scores ranged from 38-65 (preoperative) to 73-83 (postoperative). In the knot-tying group, retear rates ranged from 0% to 48%, and Constant scores ranged from 42-64 (preoperative) to 55-96 (postoperative).

Conclusion:

Despite several theoretical advantages of knotless TOE repair, both knotless and knot-tying techniques reported considerable improvement in functional outcomes after rotator cuff repair. Although tendon failure rates showed a downward trend in knotless studies, additional prospective studies are warranted to better understand the role of medial-row fixation on tendon repair integrity and postoperative clinical outcomes.

Osteoconductive resorption characteristics of a novel biocomposite suture anchor material in rotator cuff repair

BACKGROUND

Bioabsorbable suture anchors have been associated with bone-derived complications, such as osteolysis and cyst formation, after rotator cuff repair. The purpose of this study was to assess the osseous degradation process of the novel biocomposite suture anchor material polylactic-co-glycolic acid (PLGA)/beta-tricalcium phosphate (ß-TCP)/calcium sulfate (CS) after arthroscopic single-row rotator cuff repair. The focus of interest was the appearance of osteolysis and the rate of total resorption of the implants after 21 months.

METHODS

Forty-eight patients with 82 implanted suture anchors who had undergone arthroscopic rotator cuff repair between January 2015 and March 2016 at our institution were retrospectively evaluated by postoperative magnetic resonance imaging. The appearance of osteolysis was classified by measurement of the peri-implant fluid. The degree of resorption was measured by grading the persistent visibility of the anchor structures. The integrity of the rotator cuff tendon was analyzed to discover possible retear or anchor pull-out complications.

RESULTS

After a follow-up of 21.2 (± 5.4) months, osteolysis was detected in only two anchors (2.4%), and none of these defects exceeded the diameter of the former suture anchor (5.5 mm). Fifty percent of the anchors were fully degraded and no longer visible. Furthermore, only two retears of the rotator cuff occurred, and no anchor pull-out complications were detected.

CONCLUSION

PGLA/β-TCP/CS is a fully resorbable and osteoconductive suture anchor material that seems to have superior resorption characteristics compared to those of other bioabsorbable suture anchor materials commonly used in arthroscopic rotator cuff repair.

TRIAL REGISTRATION

The presented study was retrospectively registered by the commission for ethics at the Ärztekammer Nordrhein with the registration number 2016433 on January 17, 2017. All participating patients gave written consent for participation and the publication of their data.

LEVEL OF EVIDENCE

IV.

Changes in Perianchor Cyst Formation Over Time After Rotator Cuff Repair: Influential Factors and Outcomes

BACKGROUND

There is a lack of knowledge about the changes in perianchor cysts over time and the factors related to perianchor cysts.

PURPOSE

To evaluate the changes in perianchor cyst formation and anchor absorption over time after arthroscopic rotator cuff repair with a biocomposite suture anchor and to evaluate the factors affecting perianchor cyst persistence and their relationship with patient outcomes.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Forty consecutive patients (mean age, 61.10 ± 5.79 years) who underwent arthroscopic repair for medium- to large-sized rotator cuff tears using a single type of biocomposite (poly-L-lactic acid/polyglycolic acid-beta tricalcium phosphate) medial-row anchor were prospectively enrolled. Postoperative magnetic resonance imaging (MRI) at 2 different time points (6 and 18 months) was performed, and perianchor cyst formation, anchor absorption, and healing failures were evaluated using postoperative MRI. Demographic and clinical data were collected, and functional outcomes at a minimum of 18 months after surgery were assessed.

RESULTS

Perianchor cysts were observed in 24 patients (60.0% total; grade 1: 35.0%; grade 2: 10.0%; grade 3: 7.5%; grade 4: 7.5%) at 6 months, and 7 patients (18.4% total; grade 1: 7.9%; grade 2: 5.3%; grade 3: 2.6%; grade 4: 2.6%) had a persistent perianchor cyst at 18 months after surgery. No anchors were absorbed at 6 months, but 73.7% of patients revealed complete or near-full absorption at 18 months. Patients with persistent perianchor cysts showed a significantly larger tear size in the anteroposterior dimension ( P = .002) and greater retraction ( P < .001). There were no differences in healing failures and functional outcomes between patients with and without persisting perianchor cysts (all P > .05). No differences were found in perianchor cyst formation and anchor absorption between anchors inserted in the greater tuberosity and the lesser tuberosity (all P > .05).

CONCLUSION

The incidence and severity of perianchor cysts decreased with time, and most biocomposite suture anchors were absorbed at 18 months after surgery. Persisting perianchor cysts correlated with a larger tear size in the anteroposterior dimension and greater retraction.

Serial clinical and MRI examinations after arthroscopic rotator cuff reconstruction using double-row technique

PURPOSE

Rotator cuff reconstruction using arthroscopic double-row technique enables a better repair of the anatomical footprint at the tendon insertion. Objective of this serial study was to illustrate structural and functional results during recovery following double-row reconstruction.

METHODS

Forty-five patients with mid-sized ruptures of the supraspinatus tendon were assessed prospectively and underwent arthroscopic surgery using the double-row technique. Rupture localization, size, form, and extent of retraction were recorded intraoperatively. Clinical and MRI follow-up examinations were carried out for all patients after 6, 12, 26, and 52 weeks. A A standard protocol was used during the follow-up examinations to determine tendon integration, signal changes in the tendon, extent of bone marrow edema near the enclosed absorbable suture anchors, muscle changes. The clinical results were correlated with the MRI appearance.

RESULTS

After 26 weeks, the Constant score (CS) showed a highly significant increase for the first time with a value of 78 (p < 0.001). Tendon integration according to Sugaya showed a left shift over time, with higher CS-values for lower Sugaya classifications. Significant improvements in strength were first measured between the 26-week and 52-week follow-ups (9->19/p < 0.001). Highly significant improvement (p < 0.001) of the tendon signal and the fatty infiltration was found in the same time interval. The hypotrophy showed slight improvement, while a highly significant reduction of the bone marrow edema was found between weeks 12 and 26 (p < 0.001). There were no re-ruptures after week 26.

CONCLUSIONS

The present serial study showed that it took 26 weeks to reach a significant clinical improvement concerning CS. With regard to tendon healing, no further deterioration of the structural results occurred between week 26 and week 52 postoperative. There were slightly but not significant better clinical results according to the the Sugaya classification. However, parameter "strength" was significantly increased between weeks 26 and 52. This was consistent with a significant decrease in the signal intensity at the repaired tendon site, an additional improvement in the fatty infiltration, and the atrophy according to Thomazeau in the same time interval.

LEVEL OF EVIDENCE

I.

Serial MRI evaluation following arthroscopic rotator cuff repair in double-row technique

INTRODUCTION

So far, recurrent rotator cuff defects are described to occur in the early postoperative period after arthroscopic repair. The aim of this study was to evaluate the musculotendinous structure of the supraspinatus, as well as bone marrow edema or osteolysis after arthroscopic double-row repair. Therefore, magnetic resonance (MR) images were performed at defined intervals up to 2 years postoperatively.

STUDY DESIGN

Case series; Level of evidence, 3.

MATERIALS AND METHODS

MR imaging was performed within 7 days, 3, 6, 12, 26, 52 and 108 weeks after surgery. All patients were operated using an arthroscopic modified suture bridge technique. Tendon integrity, tendon retraction ["foot-print-coverage" (FPC)], muscular atrophy and fatty infiltration (signal intensity analysis) were measured at all time points. Furthermore, postoperative bone marrow edema and signs of osteolysis were assessed.

RESULTS

MR images of 13 non-consecutive patients (6f/7m, ∅ age 61.05 ± 7.7 years) could be evaluated at all time points until ∅ 108 weeks postoperatively. 5/6 patients with recurrent defect at final follow-up displayed a time of failure between 12 and 24 months after surgery. Predominant mode of failure was medial cuff failures in 4/6 cases. The initial FPC increased significantly up to 2 years follow-up (p = 0.004). Evaluations of muscular atrophy or fatty infiltration were not significant different comparing the results of all time points (p > 0.05). Postoperative bone marrow edema disappeared completely at 6 months after surgery, whereas signs of osteolysis appeared at 3 months follow-up and increased to final follow-up.

CONCLUSIONS

Recurrent defects after arthroscopic reconstruction of supraspinatus tears in modified suture bridge technique seem to occur between 12 and 24 months after surgery. Serial MRI evaluation shows good muscle structure at all time points. Postoperative bone marrow edema disappears completely several months after surgery. Signs of osteolysis seem to appear caused by bio-absorbable anchor implantations.

Distal biceps tendon repair: comparison of clinical and radiological outcome between bioabsorbable and nonabsorbable screws

BACKGROUND

Distal biceps tendon repair to the radial tuberosity can be conducted by means of an interference screw in combination with a transosseous button. Bioabsorbable interference screws have been associated with complications such as severe osteolytic reactions. We questioned whether patients with a distal biceps tendon repair with bioabsorbable poly-L-lactide (PLLA) screws had different functional, clinical, and radiologic outcome than patients with nonabsorbable poly-ether ether ketone (PEEK) screws.

METHODS

Between 2010 and 2014, 23 patients with an acute distal biceps tendon rupture were treated with reinsertion of the distal biceps tendon in a bone tunnel at the radial tuberosity through a single anterior incision using a transosseous button combined with an interference screw. A PLLA screw was used in 12 patients and a PEEK screw in 11 patients. All patients were retrospectively evaluated with a minimal follow-up of 1 year clinically and by means of the visual analog scale for pain, Mayo Elbow Performance Score, and Disabilities of Arm, Shoulder and Hand Outcome Measure score. Bone tunnel volume was measured with computed tomography segmentation.

RESULTS

Elbow mobility and arm and forearm circumference were symmetric for all patients. The visual analog scale for pain was 0.2 in the PLLA group and 0.7 in the PEEK group. The Disabilities of Arm, Shoulder and Hand score and Mayo Elbow Performance Score were 5.4 and 98.7 in the PLLA group vs. 3.1 and 95.9 in the PEEK group. Bone tunnel enlargement of 43% in the PLLA and 38% in the PEEK group was noted.

CONCLUSIONS

Clinical and functional outcome at more than 1 year after distal biceps tendon repair was excellent in both groups. Bone tunnel widening occurred in all patients.

Perianchor Cyst Formation Around Biocomposite Biodegradable Suture Anchors After Rotator Cuff Repair

BACKGROUND

Biodegradable anchors may lead to perianchor cyst formation or osteolysis. A new generation of anchors containing osteoconductive material was recently presented, but there is currently no solid evidence that this concept decreases cyst formation around anchors.

HYPOTHESIS

The null hypothesis was that the prevalence and severity of cyst formation around anchors would be similar for all 3 anchor types.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

To evaluate differences between anchor behaviors postoperatively, this study included 2 groups of patients who underwent rotator cuff repair. In group 1 (n = 38), transosseous-equivalent rotator cuff repair was performed in all patients. At the time of repair, 2 different anchors (anchor A: 23% microstructured β-tricalcium phosphate plus 77% polylactic acid enantiomers [PLLA]; and anchor B: 30% hydroxyapatite plus 70% PLLA) were used for medial-row repair. Insertion locations (anterior or posterior) were randomly assigned. In group 2 (n = 38), the same procedure was performed; however, 1 of the anchors used in group 1 was changed (anchor A: as above; and anchor C: 30% β-tricalcium phosphate plus 70% faster absorbing polylactic-co-glycolic acid copolymer [85% PLLA plus 15% polyglycolic acid]). The presence and severity of fluid collection around the anchors was evaluated by magnetic resonance imaging at approximately 1 year after rotator cuff repair (12.7 ± 0.9 months for group 1 and 12.6 ± 1.8 months for group 2).

RESULTS

In group 1, a fluid signal was observed in 14 patients (36.8%) for anchor A and in 12 patients (31.6%) for anchor B (P > .05). The severity of perianchor cyst formation was no different for the 2 anchors (respective fluid signal grades [0-4]: 24, 3, 9, 1, and 1 for anchor A; and 26, 4, 7, 1, and 0 for anchor B; P > .05). However, in group 2, cysts were observed in 19 patients (50%) for anchor A and in 3 patients (7.9%) for anchor C (P < .001). For anchor C, only 2 cases of grade 1 and 1 case of grade 2 fluid collection were observed. Intergroup analysis of anchor A revealed no significant differences in the prevalence or severity of perianchor cyst formation (P > .05). Healing failure was observed in 12 patients (31.6%) in group 1 and 10 patients (26.3%) in group 2 (P > .05).

CONCLUSION

New-generation biodegradable suture anchors seem to decrease the severity of perianchor cyst formation. Future research is required to optimize the compositions and proportions of osteoconductive materials and polymers to improve adverse reactions. Nevertheless, controlling the properties of polymers and adding osteoconductive material both appear to enhance biocompatibility.

Complications after arthroscopic labral repair for shoulder instability

Arthroscopic labral repair is a widely performed and safe technique for anterior or posterior shoulder instability; however, complications have been reported in the literature. Postoperative injection of local anesthetic via an intra-articular pain pump should be avoided to prevent chondrolysis of the glenohumeral joint. Postoperative stiffness of the shoulder can be treated with physiotherapy, and a surgical treatment is indicated in shoulders that failed a conservative treatment. Although nerve injury is relatively rare, the axillary nerve should be given careful attention. Recurrent shoulder instability is the most common complication after labral repair, but most reported rates of recurrent instability after arthroscopic Bankart repair are less than 10 %. Augmentations, such as rotator interval closure and Hill-Sachs remplissage, have a potential to reduce the rate of recurrence. A better understanding of these possible complications, including their pathology and treatment, is essential for optimization of outcomes after arthroscopic labral repair.

Magnetic resonance imaging criteria for the assessment of the rotator cuff after repair: a systematic review

PURPOSE

The purpose of this systematic review was to detect the reliability of the currently available magnetic resonance imaging measurements used in the evaluation of repaired rotator cuff.

METHODS

Search was performed using major electronic databases from their inception to February 2014. All studies reporting post-operative magnetic resonance assessment after rotator cuff repair were included. After the identification of available magnetic resonance criteria, reliability studies were further analysed. Descriptive statistics were used to summarize findings. Methodological quality was assessed using the Quality Appraisal of Reliability Studies checklist.

RESULTS

One hundred and twenty studies were included in the review. Twenty-six different criteria were identified. Ten studies reported inter-observer reliability, and only two assessed intra-observer reliability of some of the identified criteria. Structural integrity was the most investigated criterion. The dichotomized Sugaya's classification showed the highest reliability (k = 0.80-0.91). All other criteria showed moderate to low inter-observer reliability. Tendon signal intensity and footprint coverage showed a complete discordance. Intra-observer reliability was high for the presence of structural integrity, and moderate to low for all other criteria. Methodological quality was high only for one study and moderate for three studies.

CONCLUSIONS

Twenty-six different criteria described by multiple classification systems have been identified for the magnetic resonance assessment of rotator cuff after repair. Reliability of most of them has not been analysed yet. With the data available, only the presence of structural integrity showed good intra- and inter-observer agreement.

LEVEL OF EVIDENCE

Systematic review of descriptive and qualitative studies, Level IV.

Ultrasonic evaluation of the repair integrity can predict functional outcomes after arthroscopic double-row rotator cuff repair

PURPOSE

Despite proven accuracy of US for the evaluation of rotator cuff integrity, there is no US-based classification for this purpose. This study aimed to assess US for the evaluation of rotator cuff repair integrity in accordance with a well-established MRI classification.

METHODS

The authors retrospectively reviewed 257 patients who underwent arthroscopic double-row suture anchor repair for rotator cuff tears. Post-operative function was rated using the Constant score, the UCLA rating and the SSV, whereas repair integrity was assessed using US as described in the MRI classification of Sugaya et al.

RESULTS

A total of 212 patients aged 55.6 ± 9.8 years had complete functional and radiographic assessments at a mean follow-up of 36.8 ± 11.6 months. Using all three ratings, repairs of Type I had highest scores, repairs of Type II had discernibly lower scores, whereas repairs of Types III, IV and V had similar intermediate scores.

CONCLUSION

Comparison of the UCLA scores with those of Sugaya et al. revealed similar scores for repairs of Type I and of Type V. The scores are less comparable for repairs of Types II, III and IV, because US does not allow identification of partial tears if shielded by bony structures and because partial tears correspond to minimal impairment. The study reveals that US is an adequate imaging modality to classify rotator cuff repair integrity, which could reduce economic and practical burdens of CTA, MRI or MRA. The results also confirm that post-operative repair integrity and functional outcome depend on pre-operative tear size and fatty infiltration, which provides clinicians with reasoning for early surgical repair and warning of the risks of strenuous activity for patients with larger tears.

LEVEL OF EVIDENCE

Prognostic study, Level IV.

Correlation of the clinical and in vitro degradation characteristics of a poly(L-lactic acid): poly(glycolic acid) copolymer by mini meta-analysis

Absorbable internal fixation devices have built a successful clinical history in a variety of applications throughout the skeleton. Their appeal lies in their ability to lose strength and mass in a predictable reproducible manner, consistent with the healing process. Most of the evidence for their degradation properties, however, is derived from in vitro and animal studies. These methods approximate only the human clinical condition, and there are few such data available directly from patients. To better understand the absorption profile of an 85:15 poly(L-lactic acid):poly(glycolic acid) copolymer in humans, a "mini meta-analysis" was performed on 2 published studies: (1) a clinical study that followed reduction in CT image density of a cross-pin for ligament reconstruction over a 2-year interval, and (2) an in vitro study that measured the hydrolysis and strength loss of test specimens over a 10- to 11-month interval in a phosphate-buffered saline at 37 °C. The CT image density profile grossly approximated the in vitro tensile modulus profile with both quantities retaining at least half of their initial value at 44 to 52 weeks, but bore little resemblance to the rapid decreases in inherent viscosity (a measure of average molecular weight) and elongation to break (a measure of ductility), which were at half their initial values by 32 to 36 weeks. Because of the inherent difficulty in directly measuring absorbable implant degradation in patients on a routine basis, investigators should seize opportunities such as this in an effort to close the knowledge gap regarding absorbable implant degradation in humans as much as possible.

Adverse events associated with biodegradable lactide-containing suture anchors

PURPOSE

To evaluate the occurrence of adverse events and inflammatory reactions related to the use of biodegradable anchors.

METHODS

A retrospective review of a consecutive series of arthroscopic shoulder procedures using biodegradable suture anchors performed by a single surgeon was undertaken. The database was purged of patient identifiers. The blinded data were analyzed for procedure type, anchor type and composition, associated procedures, and general demographic data. Anchor composition and number were recorded. A shoulder procedure after the index operation was considered an adverse event. The nature of these procedures was evaluated using medical records, operative images, and video, looking specifically for inflammatory reactions. Any anchor-related issues were documented.

RESULTS

Three hundred sixty cases met the inclusion criteria. The procedure was a tendon repair (rotator cuff or biceps) in 265 cases and a labral repair (instability or SLAP) in 97, 2 of which were combined instability and tendon repairs. Nine different biodegradable anchors were identified, possessing 4 different polymer combinations. Adverse events (reoperations) were identified in 18 of 360 patients (5%): 13 tendon repairs and 5 labral/instability repairs. Only 2 were anchor related. In 1 tendon repair case, the anchor broke and an anchor fragment required removal. In 1 labral repair case, the anchor eyelet (a suture) loosened from the anchor body and eroded the humeral head. No cases of inflammatory synovitis were observed. No statistical difference in adverse event rates existed between tendon and labral repairs (P > .05).

CONCLUSIONS

Anchor-specific adverse events occurred in 2 of 360 procedures (0.5%). One was anchor design related (the prominent head containing the suture eyelet broke off) in a poly-L-lactic acid (PLLA) anchor. One was anchor material related and occurred when the poly-levo (70%)/dextro (30%)-lactide anchor body reabsorbed, loosening the encased eyelet suture and allowing this suture to migrate into the joint. No inflammatory reactions were documented in the slowly degrading pure PLLA or more rapidly degrading biocomposite PLLA/β-tricalcium phosphate-based anchors.

LEVEL OF EVIDENCE

Level IV, retrospective review, therapeutic study.