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

Proximal Tibia Fracture Through Suture Augmentation Sites Following ACL/MCL Repairs: A Case Report

CASE

A 35-year-old man sustained a proximal tibia fracture from a low-energy mechanism 1 year after anterior cruciate and medial collateral ligament repairs with suture augmentation (SA). The fracture propagated through both tibial SA anchor sites. Following intramedullary tibial nailing, he returned to his prior level of function.

CONCLUSION

While complications of SA for ligamentous procedures are rare, these techniques are being implemented more frequently and the full complication profile is yet to be determined. Our report documents a new complication and potential risk factors that surgeons should consider when performing SA for multiligament knee surgery in active individuals.

Current Understanding and New Advances in the Surgical Management of Reparable Rotator Cuff Tears: A Scoping Review

Rotator cuff (RC) tears are among the most common musculoskeletal disorders and can be associated with pain, weakness, and shoulder dysfunction. In recent years, there have been significant advances with regard to the understanding of rotator cuff disease and its management. With technological improvements and advanced diagnostic modalities, there has been much progress as to improved understanding of the pathology. Similarly, with advanced implant designs and instrumentation, operative techniques have evolved. Furthermore, refinements in postoperative rehabilitation protocols have improved patient outcomes. In this scoping review, we aim to provide an overview of the current knowledge on the treatment of rotator cuff disorders and to highlight recent advances in its management.

Biocompatibility and Biological Performance of Additive-Manufactured Bioabsorbable Iron-Based Porous Interference Screws in a Rabbit Model: A 1-Year Observational Study

This study evaluated the mid-term (12-month) biomechanical, biocompatibility, and biological performance of additive-manufactured bioabsorbable iron-based interference screws (ISs). Two bioabsorbable iron IS types-manufactured using pure iron powder (iron_IS) and using pure iron powder with 0.2 wt% tricalcium phosphate (TCP_IS)-were compared with conventional metallic IS (control) using in vitro biocompatibility and degradation analyses and an in vivo animal study. The in vitro ultimate failure strength was significantly higher for iron_IS and TCP_IS than for control ISs at 3 months post-operatively; however, the difference between groups were nonsignificant thereafter. Moreover, at 3 months after implantation, iron_IS and TCP_IS increased bone volume fraction, bone surface area fraction, and percent intersection surface; the changes thereafter were nonsignificant. Iron_IS and TCP_IS demonstrated degradation over time with increased implant surface, decreased implant volume, and structure thickness; nevertheless, the analyses of visceral organs and biochemistry demonstrated normal results, except for time-dependent iron deposition in the spleen. Therefore, compared with conventional ISs, bioabsorbable iron-based ISs exhibit higher initial mechanical strength. Although iron-based ISs demonstrate high biocompatibility 12 months after implantation, their corrosive iron products may accumulate in the spleen. Because they demonstrate mechanical superiority along with considerable absorption capability after implantation, iron-based ISs may have potential applications in implantable medical-device development in the future.

Biocompatibility and Biological Performance Evaluation of Additive-Manufactured Bioabsorbable Iron-Based Porous Suture Anchor in a Rabbit Model

This study evaluated the biocompatibility and biological performance of novel additive-manufactured bioabsorbable iron-based porous suture anchors (iron_SAs). Two types of bioabsorbable iron_SAs, with double- and triple-helical structures (iron_SA_2_helix and iron_SA_3_helix, respectively), were compared with the synthetic polymer-based bioabsorbable suture anchor (polymer_SAs). An in vitro mechanical test, MTT assay, and scanning electron microscope (SEM) analysis were performed. An in vivo animal study was also performed. The three types of suture anchors were randomly implanted in the outer cortex of the lateral femoral condyle. The ultimate in vitro pullout strength of the iron_SA_3_helix group was significantly higher than the iron_SA_2_helix and polymer_SA groups. The MTT assay findings demonstrated no significant cytotoxicity, and the SEM analysis showed cells attachment on implant surface. The ultimate failure load of the iron_SA_3_helix group was significantly higher than that of the polymer_SA group. The micro-CT analysis indicated the iron_SA_3_helix group showed a higher bone volume fraction (BV/TV) after surgery. Moreover, both iron SAs underwent degradation with time. Iron_SAs with triple-helical threads and a porous structure demonstrated better mechanical strength and high biocompatibility after short-term implantation. The combined advantages of the mechanical superiority of the iron metal and the possibility of absorption after implantation make the iron_SA a suitable candidate for further development.

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.

Serial Changes in Perianchor Cysts Following Arthroscopic Labral Repair Using All-Suture Anchors

Backgroud

Changes in perianchor cysts around the all-suture anchors, which demonstrate distinguished features from the biocomposite anchors, have not been revealed sufficiently. The purpose of this study was to investigate serial changes of perianchor cysts according to the location of the inserted anchor in the glenoid in arthroscopic labral repair using all-suture anchors.

Methods

We enrolled 43 patients who underwent computed tomography (CT) immediately postoperatively and CT arthrogram (CTA) at 1 year or 2 years after arthroscopic labral repair using a 1.3-mm all-suture anchor for recurrent anterior shoulder dislocation with or without a superior labral tear from anterior to posterior and a posterior labral tear. The mean diameter and tissue density (HU) of perianchor cysts were measured depending on the location in the glenoid. Clinical outcomes, labral healing, and redislocation rate were evaluated at 2 years after surgery.

Results

On functional assessment, the mean American Shoulder and Elbow Surgeons score and Rowe score improved statistically significantly after surgery (from 47.9 ± 14.3 preoperatively to 90.1 ± 9.6 postoperatively and from 45.3 ± 12.4 preoperatively to 92.2 ± 10.1 postoperatively, respectively; p < 0.01). Postoperative redislocations were found in 2 patients (4.7%). In radiological evaluation, the mean diameter of perianchor cysts at postoperative 1 year (3.24 ± 0.65 mm) was significantly larger than the immediate postoperative diameter; however, there was no significant difference between postoperative 1 year and 2 years (3.23 ± 0.57 mm). Tissue density at the center of cysts demonstrated no significant difference between 1 and 2 year postoperatively (107.7 ± 29.8 HU [superior], 99.7 ± 31.7 HU [anteroinferior], and 105.1 ± 25.0 HU [posterior] vs. 109.1 ± 26.1 HU [superior], 106.4 ± 30.3 HU [anteroinferior], and 111.0 ± 32.9 HU [posterior]). The mean diameter of perianchor cysts in the anteroinferior position was largest compared with that in superior or posterior positions.

Conclusions

Perianchor cysts associated with all-suture anchors enlarged significantly within 1 year after arthroscopic labral repair regardless of the insertion location in the glenoid. However, the size and tissue density of perianchor cysts were similar at postoperative 1 and 2 years, and satisfactory stability and clinical outcomes were obtained.

Peri-anchor cyst formation after arthroscopic bankart repair: comparison between biocomposite suture anchor and all-suture anchor

Background

The purpose of this study is to investigate clinical outcomes and radiological findings of cyst formation in the glenoid around suture anchors after arthroscopic Bankart repair with either biocomposite suture anchor or all-suture anchor in traumatic anterior shoulder instability. We hypothesized that there would be no significant difference in clinical and radiological outcomes between the two suture materials.

Methods

This retrospective study reviewed 162 patients (69 in group A, biocomposite anchor; 93 in group B, all-suture anchor) who underwent arthroscopic Bankart repair of traumatic recurrent anterior shoulder instability with less than 20% glenoid defect on preoperative en-face view three-dimensional computed tomography. Patient assignment was not randomized.

Results

At final follow-up, the mean subjective shoulder value, Rowe score, and University of California, Los Angeles shoulder score improved significantly in both groups. However, there were no significant differences in functional shoulder scores and recurrence rate (6%, 4/69 in group A; 5%, 5/93 in group B) between the two groups. On follow-up magnetic resonance arthrography/computed tomography arthrography, the incidence of peri-anchor cyst formation was 5.7% (4/69) in group A and 3.2% (3/93) in group B, which was not a significant difference.

Conclusions

Considering the low incidence of peri-anchor cyst formation in the glenoid after Bankart repair with one of two anchor systems and the lack of association with recurrence instability, biocomposite and all-suture anchors in Bankart repair yield satisfactory outcomes with no significant difference.

Reliability of open architecture anchors in biocomposite material: medium term clinical and MRI evaluation. Our experience

OBJECTIVES

Comparing radiologic bone ingrowth and the clinical outcomes of an open-construct (PEEK) (polyether ether ketone) suture anchor with those of a bio-composite suture anchor (glycolic polylactic acid anchors, beta-tricalcium phosphate and calcium sulphate) in patients with arthroscopic rotator cuff repair.

METHODS

From August 2017 to January 2019, 33 patients of both sexes, aged between 44 and 78 years underwent arthroscopic rotator cuff repair for tears considered repairable with an extension not exceeding4 cm. The bioabsorbable anchors used comprised glycolic polylactic acid/beta-tricalcium phosphate/ calcium sulphate, and the non-absorbable anchors in polyetheretherketone (PEEK). All patients underwent MRI evaluation at 12 months postoperatively to determine complications and identify any re-tear.

RESULTS

Clinical scores showed an improvement from both clinical and functional point of view. There were no statistically significant changes compared to the physical examination. On radiographs, mobilizations, anchor pull-outs or other complications did not occur in each group.

CONCLUSIONS

Shoulder function improved after complete repair of the rotator cuff and similar clinical results were achieved regardless of the material and shape of the suture anchor. The bioabsorbable anchors in innovative open architecture material seem to have results comparable to peek anchors. Unfortunately, further studies are needed to define the advantages in using one material compared to the other. (www.actabiomedica.it).

Editorial Commentary: Fill It up: The Fate of "Absorbable" Implants

Surgeons make conscious decisions daily regarding implants. But do they really know what happens in the body to "absorbable anchors?" How long does it take to resorb, and what fills the space left behind? Absorbable materials can be very different, and well-done studies are important to help us understand the process and to guide our decisions.

Osteointegration of a Biocomposite Suture Anchor After Arthroscopic Shoulder Labral Repair

PURPOSE

To evaluate osteoconductivity of a poly-L-lactide co-glycolide (PLG)-calcium sulfate (CS)-β-tricalcium phosphate (β-TCP) biocomposite suture anchor after arthroscopic shoulder labral repair.

METHODS

The subjects of this study were patients who participated in a clinical trial for acquisition of marketing approval of a PLG-CS-β-TCP biocomposite anchor in Japan. They underwent arthroscopic labral repair using the anchor, and computed tomographic (CT) images of the glenoid were obtained 2 years after surgery. Osteoconductivity at the anchor sites was evaluated with the CT images using the established ossification quality score. Shoulder function scores including the Rowe score and Japanese Shoulder Society shoulder instability score were also assessed 2 years after surgery.

RESULTS

CT images and functional scores were obtained from 37 patients, comprising 29 men and 8 women with a mean age of 29 years (range, 25-33 years) at surgery. A total of 148 anchors were implanted in the 37 shoulders. Osteoconductivity was seen in 133 of 148 anchor sites (90.0%) 2 years after implantation. No significant differences in osteoconductivity were found by anchor diameter or position. The Rowe score significantly improved from 39.9 points (95% confidence interval [CI], 33.8-45.9 points) preoperatively to 96.6 points (95% CI, 95.1-98.1 points) at 2 years postoperatively (P < .001). The Japanese Shoulder Society shoulder instability score also significantly improved, from 63.1 points (95% CI, 58.4-67.7 points) preoperatively to 96.3 points (95% CI, 94.7-97.8 points) at 2 years postoperatively (P < .001).

CONCLUSIONS

Biocomposite suture anchors made of PLG, CS, and β-TCP exhibited some osteoconductivity 2 years after arthroscopic labral repair, as well as good clinical outcomes.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Enhanced release of calcium phosphate additives from bioresorbable orthopaedic devices using irradiation technology is non-beneficial in a rabbit model: An animal study

Objectives

Bioresorbable orthopaedic devices with calcium phosphate (CaP) fillers are commercially available on the assumption that increased calcium (Ca) locally drives new bone formation, but the clinical benefits are unknown. Electron beam (EB) irradiation of polymer devices has been shown to enhance the release of Ca. The aims of this study were to: 1) establish the biological safety of EB surface-modified bioresorbable devices; 2) test the release kinetics of CaP from a polymer device; and 3) establish any subsequent beneficial effects on bone repair in vivo.

Methods

ActivaScrew Interference (Bioretec Ltd, Tampere, Finland) and poly(L-lactide-co-glycolide) (PLGA) orthopaedic screws containing 10 wt% β-tricalcium phosphate (β-TCP) underwent EB treatment. In vitro degradation over 36 weeks was investigated by recording mass loss, pH change, and Ca release. Implant performance was investigated in vivo over 36 weeks using a lapine femoral condyle model. Bone growth and osteoclast activity were assessed by histology and enzyme histochemistry.

Results

Calcium release doubled in the EB-treated group before returning to a level seen in untreated samples at 28 weeks. Extensive bone growth was observed around the perimeter of all implant types, along with limited osteoclastic activity. No statistically significant differences between comparative groups was identified.

Conclusion

The higher than normal dose of EB used for surface modification did not adversely affect tissue response around implants in vivo. Surprisingly, incorporation of β-TCP and the subsequent accelerated release of Ca had no significant effect on in vivo implant performance, calling into question the clinical evidence base for these commercially available devices.

Cite this article: I. Palmer, S. A. Clarke, F. J Buchanan. Enhanced release of calcium phosphate additives from bioresorbable orthopaedic devices using irradiation technology is non-beneficial in a rabbit model: An animal study. Bone Joint Res 2019;8:266–274. DOI: 10.1302/2046-3758.86.BJR-2018-0224.R2.

Comparison of Clinical Outcomes and Computed Tomography Analysis for Tunnel Diameter After Arthroscopic Bankart Repair With the All-Suture Anchor and the Biodegradable Suture Anchor

PURPOSE

To compare the clinical outcomes and radiological findings at the anchor site after arthroscopic Bankart repair with all-suture anchors and biodegradable suture anchors in patients with recurrent anterior shoulder dislocation.

METHODS

The patients who underwent arthroscopic Bankart repair were divided into 2 groups depending on the type of the suture anchor used in different periods. Power analysis was designed based on the postoperative Rowe score. Clinical outcomes, including the Rowe score, American Shoulder and Elbow Surgeons score, subjective instability, and redislocation rates were evaluated. In all patients enrolled, the tunnel diameter of the anchor was assessed with computed tomography arthrogram at 1 year postoperatively. The Institutional Review Board of Ewha Womans University approved this study (no. EUMC 2017-05-058).

RESULTS

A total of 67 patients were enrolled: 33 underwent surgery with a 1.3-mm (single-loaded) or 1.8-mm (double-loaded) all-suture anchor (group A), and 34 underwent surgery with a 3.0-mm biodegradable anchor (10.8 mm in length, 30% 1,2,3-trichloropropane/70% poly-lactide-co-glycolic acid) (group B). There were no significant differences in clinical outcomes between groups A and B in the American Shoulder and Elbow Surgeons score (preoperatively, 51.2 ± 13.7 vs 47.7 ± 12.2; 2 years postoperatively, 88.5 ± 12.3 vs 89.7 ± 10.9; P = .667) and Rowe score (preoperatively, 41.4 ± 10.5 vs 41.3 ± 9.4; 2 years postoperatively, 87.9 ± 14.9 vs 88.5 ± 14.6; P = .857). Postoperative redislocation (6.1% vs 5.9%, P = .682) and subjective instability rate (12.2% vs 17.7%, P = .386) of both groups showed no significant difference. Average tunnel diameter increment was significantly greater with the 1.8-mm all-suture anchor (2.8 ± 0.9 mm) than the 1.3-mm all-suture anchor (1.2 ± 0.8 mm) and 3.0-mm biodegradable anchor (0.8 ± 1.2 mm) (P < .001).

CONCLUSIONS

Arthroscopic Bankart repair with the all-suture anchor showed comparable clinical outcomes and postoperative stability as the conventional biodegradable suture anchor at 2 years after surgery. Tunnel diameter increment of the all-suture anchor was significantly greater than that of the biodegradable suture anchor at the 1-year computed tomography analysis. Although tunnel diameter increment was greater with the all-suture anchor, it did not influence the clinical outcomes.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Rotator cuff repair with all-suture anchors: a midterm magnetic resonance imaging evaluation of repair integrity and cyst formation

BACKGROUND

This study investigated the feasibility and safety of all-suture anchors in arthroscopic rotator cuff repair.

METHODS

All patients were diagnosed with a rotator cuff tear by ultrasound or magnetic resonance imaging (MRI). Patients with partial tears, massive tears, subscapularis tears, or previous shoulder surgery, were excluded. MRI and clinical outcome were investigated in all patients at 1.58 years (range, 1.0-2.0 years) after rotator cuff repair with all-suture anchors (prospective case series). Integrity of the cuff repair, cyst formation (encapsulated fluid signal around the anchor), ingrowth of the bone into the anchor, and integrity of the bone tunnel border were evaluated for 47 anchors. Clinical results were evaluated using the Constant-Murley score.

RESULTS

An MRI evaluation was performed in 20 patients at 1.58 years (range, 1.0-2.0 years) after rotator cuff repair with all-suture anchors. MRI evaluation showed a very small rim of fluid around 10% of the anchors. None of the anchors showed cyst formation with fluid diameter more than twice the anchor diameter. In approximately 90% of the anchors, no fluid could be detected between the anchors and the edge of the bony tunnel. Full rotator cuff integrity was seen in 19 patients. Only 1 patient sustained a retear. Clinical results comparable with an arthroscopic rotator cuff repair using classic anchors were seen.

CONCLUSIONS

This prospective clinical cohort study shows promising early radiographic and clinical results after arthroscopic rotator cuff repair using all-suture anchors.

Glenoid Bone Reaction to All-Soft Suture Anchors Used for Shoulder Labral Repairs

BACKGROUND

All-soft suture anchors (ASSAs) are commonly used for shoulder labral repair and capsulorrhaphy in patients with shoulder instability. While these anchors may have some specific advantages over other types of suture anchors, little is known about the prevalence and time-dependence of bone cyst formation and tunnel expansion after implantation of ASSAs. The aim of this study was to quantify the proportions of cyst formation and tunnel expansion around ASSAs and to characterize and test for differences in abnormalities observed at different postoperative time points.

METHODS

Thirty patients who were treated with arthroscopic shoulder stabilization surgery with ASSAs (1.4 mm; JuggerKnot, Biomet) underwent a computed tomography (CT) scan of the operatively treated shoulder at 1 month (10 patients), 6 months (10 patients), or 12 months (10 patients) postoperatively. Demographic and operative data were collected, and CT scans were evaluated for cyst formation, tunnel expansion, and tunnel volume measured in cubic millimeters. Statistical analyses were performed to detect differences in these outcomes among the follow-up groups. All shoulders were stable at all time points of the study, and there were no incidents of recurrent instability during the study period.

RESULTS

Ninety-one suture anchors were evaluated in 30 patients. Tunnel expansion was identified in the large majority of patients in the 6-month and 12-month follow-up groups, with a significant increase in these proportions compared with the 1-month follow-up group (p = 0.002). Mean tunnel volumes also significantly increased over the study period (p < 0.001). The presence of cyst formation was negligible in all 3 follow-up cohorts.

CONCLUSIONS

This study demonstrated low rates of cyst formation but a significantly increased tunnel volume 6 and 12 months after shoulder labral surgery with ASSAs. There was no association with the initial tunnel location. Additional well-controlled studies with longer follow-up are needed to identify potential associations among tunnel expansion, intraoperative technique, and clinical outcomes.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Degradation of Cylindrical Poly-Lactic Co-Glycolide/Beta-Tricalcium Phosphate Biocomposite Anchors After Arthroscopic Bankart Repair: A Prospective Study

The purpose of this study was to examine widening and ossification of anchor holes after arthroscopic Bankart repair with the use of cylindrical biocomposite anchors made of 70% poly-L-lactide-co-glycolide acid (PLGA) and 30% beta-tricalcium phosphate (ß-TCP). Twenty-two patients were enrolled in a clinical trial to acquire marketing approval of a PLGA/ß-TCP biocomposite suture anchor in Japan and underwent arthroscopic Bankart repairs with the anchors. Eleven of 22 patients had computed tomography scans after 2-year follow-up. Three surgeons independently evaluated width and ossification of anchor holes in 4 grades using computed tomography scans. When the evaluations disagreed, the final grade was determined based on the 3 surgeons' consensus. Seven men and 4 women were evaluated at a mean of 30 months (range, 28-32 months) after surgery, and a total of 47 anchors were implanted. Anchor holes were narrowed in 39 (83%) of 47 anchor sites and were almost or completely filled in (type 3 or 4) in 21 (45%) of 47 anchor sites. Ossification was seen in 46 (98%) of 47 anchor sites and was nearly complete or complete (type 3 or 4) in 16 (34%) of 47 anchor sites. There were no significant differences in both anchor hole width and ossification score on comparison of the anteroinferior (4- to 6-o'clock positions in the right shoulder) with other anchor sites. Cylindrical biocomposite anchors made of 70% PLGA/30% ß-TCP showed a low incidence of anchor hole widening and excellent ossification regardless of anchor site. [Orthopedics. 2018; 41(3):e348-e353.].

Avoiding Tommy John Surgery: What Are the Alternatives?

The number of ulnar collateral ligament (UCL) reconstructions being performed has risen sharply in recent years, most notably in the young amateur athlete. While successful outcomes have been reported with reconstruction, the surgery and the associated rehabilitation timeline may be difficult for the nonelite athlete to incur. Return-to-play expectations, along with level of competition, should help guide surgeons in exploring management options. While reconstruction remains a mainstay, focused research exploring nonreconstructive options has expanded. This review discusses the clinical approach to those with UCL injury, including current support for rehabilitation, biologic strategies, and available repair or augmentation alternatives.

Biocomposite Implants Composed of Poly(Lactide-co-Glycolide)/β-Tricalcium Phosphate: Systematic Review of Imaging, Complication, and Performance Outcomes

PURPOSE

To determine the degradation and performance outcomes of poly(lactide-co-glycolide)/β-tricalcium phosphate (PLGA/β-TCP) implants.

METHODS

A MEDLINE and Embase search for randomized or nonrandomized controlled studies and prospective or retrospective case series that used biocomposite interference screws or suture anchors composed of PLGA/β-TCP was performed. Main outcomes included volume of implant resorption and incidence of osteoconductivity at implant sites, imaging findings, adverse events, and the frequency of reoperations.

RESULTS

A total of 13 studies representing 668 patients with either knee or shoulder implants were included. Median follow-up was 28 months (range: 12-37 months). Biocomposite implants lost 88% of their original volume during follow-up. Osteoconductivity at the implant site was identified in 63% of cases. Adverse events included tunnel widening (3%), effusion (5%), and cyst formation (4%). Synovitis was not reported.

CONCLUSIONS

Biocomposite interference screws or suture anchors composed of PLGA/β-TCP almost fully absorb over 3 years while promoting osteoconductivity with few reported adverse events.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I-IV studies.

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.

Postoperative imaging of bioabsorbable anchors in rotator cuff repair

BACKGROUND

Bioabsorbable anchors may lead to osteolysis and cyst formation. However, the prevalence of these outcomes is not known for rotator cuff repairs.

PURPOSE

To evaluate cyst formation after placement of bioabsorbable anchors for rotator cuff repairs and to verify whether bioabsorbable anchors degraded as intended and preserved bone stock for possible revision compared with metal anchors. The null hypothesis was that the rate and severity of cyst formation around the anchor are negligible.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Between April 2008 and November 2011, a total of 209 patients (85 men, 124 women) underwent rotator cuff repair with bioabsorbable suture anchors (113 with polylactic acid enantiomers [PLLA] and 96 with poly-D,L-lactide from L-lactide and D-lactide [PLDLA]); the patients underwent magnetic resonance imaging (MRI) evaluation more than 10 months after surgery. The fluid signal around the anchor on T2-weighted MRI scans was graded as follows: grade 0, no fluid around anchor; grade 1, minimal fluid around anchor; grade 2, local fluid around anchor; grade 3, fluid collection around entire length of anchor with cyst diameter less than twice the anchor diameter; and grade 4, cyst diameter larger than grade 3. The integrity of repairs was also evaluated.

RESULTS

Cysts were observed in 97 instances (46.4%). There were 41 grade 1 cases (19.6%), 16 grade 2 (7.7%), 22 grade 3 (10.5%), and 18 grade 4 (8.6%). Healing of repaired tendon was observed in 131 patients (62.7%). There was no statistical difference in healing rate between patients with and without cyst formation (66.1% vs 58.8%; P = .276). Altered anchor shape and absorption were not observed in most of the patients. However, in 12 patients (6 with PLLA and 6 with PLDLA anchors), T2-weighted scans showed that the signal intensity of anchors had changed since surgery, which could indicate that absorption had taken place; nonetheless, even in these 12 patients, anchors were clearly visible on T1-weighted scans.

CONCLUSION

Osteolysis and cyst formation are common complications following the use of bioabsorbable anchors in rotator cuff repairs. Considering that adequate absorption of anchors and preservation of bone stock are the reasons for using bioabsorbable anchors, use of these anchors should be reconsidered because of possible interference with revision surgery.

The evolution of suture anchors in arthroscopic rotator cuff repair

The advancement of suture anchor design and technology has fostered the transition from open to arthroscopic rotator cuff repair. Current suture-bridging constructs have greatly surpassed the biomechanical strength parameters of transosseous repairs and have shown impressive healing rates after arthroscopic rotator cuff repair. This review describes this evolution and discusses the important characteristics of suture anchors.