Comparative biomechanical study of five systems for fixation of the coracoid transfer during the Latarjet procedure for treatment of anterior recurrent shoulder instability

Sutures, Screws, Buttons, and Anchors: A Review of Current Bone Graft Fixation Devices for Glenoid Bone Loss in the Unstable Shoulder

PURPOSE OF REVIEW

Anterior shoulder instability is associated with concomitant injury to several stabilizing structures of the shoulder, including glenoid bone loss. While instability is most common in young athletes and patients with predisposing conditions of hyperlaxity, recurrent shoulder instability can occur throughout various age ranges and may lead to longer term effects including pain and shoulder arthritis. Glenoid bone loss exceeding certain thresholds is generally treated by glenoid reconstruction via bone block augmentation to adequately stabilize the glenohumeral joint. These procedures increase the width of the articular surface on which the humeral head can translate before dislocation and, based on the procedure performed, provide a sling effect via the conjoined tendon, and increase tension to support the anterior capsule. The purpose of this review is to summarize the available literature regarding bone block fixation techniques.

RECENT DEVELOPMENTS

Various fixation techniques have been utilized to secure bone block transfers. Though screw fixation has traditionally been used for bone block fixation, suture buttons, suture anchors, and all-suture techniques have been utilized in attempts to avoid complications associated with the use of screws. Biomechanical studies report variable force-resistance, displacement, and mode of failure when comparing screw to suture button-based fixation of glenoid bone blocks. Clinical and radiographic studies have shown these novel suture-based techniques to be comparable, and in some cases advantageous, to traditional screw fixation techniques. While screw fixation has long been the standard of care in glenoid bone block procedures, it is associated with high complication rates, leading surgeons to endeavor toward new fixation techniques. In available biomechanical studies, screw fixation has consistently demonstrated high maximal load-to-failure and displacement with cyclic loading. Studies have reported similar clinical and radiographic outcomes in both screw and suture-based fixation methods, with evidence of reduced bone resorption with suture fixation. While suture button fixation is associated with a higher rate of recurrent instability, overall complication rates are low. Future research should address biomechanical shortcomings of suture-based fixation techniques and continue to assess long-term follow-up of patients treated with each fixation method.

Suture Button Fixation in Latarjet Has Similar Load to Failure and Clinical Outcomes but Lower Bone Resorption Compared With Screw Fixation: A Systematic Review

PURPOSE

To compare the 2 Latarjet fixation techniques-screw fixation (SF) versus suture button (SB) -for clinical, biomechanical, and radiologic outcomes.

METHODS

A systematic review was conducted in accordance with Preferred Reporting Items for Systematic and Meta-Analyses guidelines using MEDLINE and Embase databases and was prospectively registered on PROSPERO. Only comparative clinical and biomechanical studies of Latarjet with SF and SB were included. Studies were appraised using the Methodical Index for Non-Randomised Studies (MINORS) tool.

RESULTS

Eleven studies met eligible criteria: 7 clinical studies (SB, n = 279; SF, n = 845) and 4 biomechanical. In total, 80.9% (SB) and 84.2% (SF) of patients were male. Follow-up ranged from 6 to 63.6 months. The overall recurrent instability rate for SB ranged from 0 to 8.3% and for SF ranged from 0 to 2.75%. Only one study demonstrated a greater recurrent instability rate with SB (P = .02). Overall SB complication rates ranged from 0 to 12.5% and SF ranged from 0 to 27%. Two studies reported greater complications and reoperations with SF related to hardware. Summary forest plots from 4 studies showed no significant difference in Walch Duplay score (mean difference, range -5.00 to 1.20 [95% confidence interval {CI} -12.13 to 8.56], I2 inconsistency = 0%), Rowe score (mean difference, range -2.00 to 4.00 [95% CI -7.37 to 7.66], I2 inconsistency = 45%), and VAS for pain (mean difference, range -0.10 to 0.60 [95% CI -0.72 to 1.33], I2 inconsistency = 0%). There was no statistically significant difference between SB and SF in the postoperative range of motion. Radiologically, there was no significant difference in graft positioning and union at final follow-up, but graft resorption was greater in SF (range 25.2%-47.6%) compared with SB (range 10.1%-18.5%). Biomechanical studies showed no significant difference in maximum load to failure (SB, range 184-266 N vs SF, range 148-288 N).

CONCLUSIONS

Clinically, SB fixation demonstrated similar functional outcome and range of motion when compared with SF, with the potential benefit of lower rates of graft resorption and hardware-related complications. Biomechanically there was no difference in maximum load to failure.

LEVEL OF EVIDENCE

Level III, systematic review of Level III and biomechanical studies.

Editorial Commentary: Suture Button Fixation for the Latarjet Procedure Is Superior to Screw Fixation

An increasing body of evidence suggests that suture button fixation is comparable with screw fixation in Latarjet and potentially associated with reduced graft resorption. Suture button fixation may facilitate performing the Latarjet procedure, particularly when done in an arthroscopic manner. The use of suture button fixation technique theoretically facilitates improved positioning of the graft on the glenoid, as it frees the surgeon from the potential of the soft-tissue envelope to impact positioning of the graft, which can occur with screw-based guides. The bone graft can be shuttled into an optimal position and then tensioned with relative ease in comparison with screw-based techniques. Suture button fixation results in lower complication rates compared with screw fixation; almost one third of the screw fixation complications are hardware-related, and screw fixation results in a high rate of hardware removal. Moreover, the arthroscopic Latarjet suture button literature is published by experienced surgeons. Arthroscopic Latarjet has a significant learning curve, reducing the translatability of studies that report superior findings with any one technique. The generalizability of results reminds us that evidence-based medicine should be practiced through the lens of not only patient preferences, but also through an honest appraisal of a surgeon's own ability.

Inlay structure can improve bone graft stability in the Bristow procedure

BACKGROUND

Compared with the Latarjet procedure, the Bristow procedure has a lower screw-related complication rate but poor bone healing. A modified Inlay Bristow procedure has been reported to significantly improve the bone healing rate, but the biomechanical mechanism is unclear. The aim of this study was to evaluate the biomechanical stability of the bone graft between a modified Inlay Bristow procedure and the classic Bristow procedure.

METHODS

Sixteen left scapula models (Sawbones, Composite Scapula, and fourth generation) were randomly divided into 2 groups (8:8). The bone graft in the first group was fixed with a 3.5 mm screw using the Inlay structure. The bone graft in the second group was fixed with a 3.5 mm screw via the traditional method. The maximum cyclic displacement, ultimate failure load and stiffness were evaluated biomechanically. The failure type was recorded for each model.

RESULTS

Cyclic loading tests demonstrated that the maximum cyclic displacement of the Inlay procedure was significantly smaller (P = .001) than that of the classic procedure. The Inlay Bristow technique resulted in a significantly higher (P = .024) ultimate failure load than the classic Bristow technique. The stiffness of the classic group was 19.17 ± 4.01 N/mm and that of the inlay group was 22.34 ± 5.35 N/mm (P = .232). Failure was mainly due to bone graft fractures through the drill hole or glenoid bone fractures.

CONCLUSION

Inlay Bristow fixation of the bone graft in a Sawbones model provides significantly stronger fixation and better time point zero stability than classic Bristow fixation, suggesting a higher likelihood of graft union.

Suspensory fixation for bone transfer procedures in shoulder instability is superior to screws in an angled construct: a biomechanical analysis

Background

The Latarjet procedure is a common bony augmentation procedure for anterior shoulder instability. Historically, screw fixation is used to secure the coracoid graft to the anterior glenoid surface; however, malpositioning of the graft leads to oblique screw insertion that contributes to complications. Suture buttons (SBs) are a more recent fixation technique that have not been studied alongside standard screw fixation in the context of biomechanical models of angulated fixation. This study aims to compare the biomechanical strength of single and double, screw and SB fixation at various levels of angulation.

Methods

Testing was performed using polyurethane models from Sawbones. The graft piece was secured with screw fixation (Arthrex, Naples, FL, USA) or suspensory button (ABS Tightrope, Arthrex, Naples, FL, USA). Single or double constructs of screws and SBs were affixed at 0°, 15°, and 30° angles to the face of the glenoid component. An aluminum testing jig held the samples securely while a materials testing system applied loads. Five constructs were used for each condition and assessed load to failure testing.

Results

For single fixation constructs, suspensory buttons were 60% stronger than screws at 0° (P < .001), and 52% stronger at 15° (P = .004); however, at 30°, both were comparable (P = .180). Interestingly, single suspensory button at 15° was equivalent to a single screw at 0° (P = .310). For double fixation, suspensory buttons (DT) were 32% stronger than screws at 0° (P < .001) and 35% stronger than screws at 15° (P < .001). Both double fixation methods were comparable at 30° (P = .061). Suspensory buttons at 15° and 30° were equivalent to double screws at 0 (P = .280) and 15° (P = .772), respectively.

Conclusion

These measurements indicate that the suspensory button has a significantly higher load to failure capacity over the screw fixation technique, perpendicularly and with up to 15° of angulation. These analyses also indicate that the suspensory button fixation offers superior strength even when positioned more obliquely than the screw fixation. Therefore, suspensory button fixation may confer more strength while offering greater margin for error when positioning the graft.

A Systematic Review of Screw and Suture Button Glenoid Augmentation Constructs

Background

Glenohumeral dislocations often lead to glenoid bone loss and recurrent instability, warranting bony augmentation. While numerous biomechanical studies have investigated fixation methods to secure a graft to the glenoid, a review of available constructs has yet to be performed.

Purpose

To synthesize the literature and compare the biomechanics of screw and suture button constructs for anterior glenoid bony augmentation.

Study Design

Systematic review.

Methods

A systematic review was conducted in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. There were 2 independent reviewers who performed a literature search using the PubMed, Embase, and Google Scholar databases of studies published between 1950 and 2020. Studies were included that compared the biomechanical outcomes of fixation for the treatment of anterior shoulder instability with glenoid bone loss.

Results

Overall, 13 of the 363 studies screened met the inclusion criteria. The included studies measured the biomechanical strength of screws or suture buttons on a cadaveric or synthetic Latarjet construct. Screws and suture buttons were biomechanically similar, as both constructs exhibited comparable loads at failure and final displacement. Screw type (diameter, threading, or composition) did not significantly affect construct strength, and double-screw fixation was superior to single-screw fixation. Additionally, 2 screws augmented with a small plate had a higher load at failure than screws that were not augmented. Unicortical double-screw fixation was inferior to bicortical double-screw fixation, although construct strength did not significantly decrease if 1 of these screws was unicortical. Further, 2 screws inserted at 15° off axis experienced significantly higher graft displacement and lower ultimate failure loads than those inserted at 0° parallel to the glenoid.

Conclusion

Suture buttons provided comparable strength to screws and offer an effective alternative to reduce screw-related complications. Augmentation with a small plate may clinically enhance construct strength and decrease complications through the dispersion of force loads over a greater surface area. Differences in screw type did not appear to alter construct strength, provided that screws were placed parallel to the articular surface and were bicortical.

Bristow-Latarjet Surgery: A Current Overview in Brazil

Objective  To provide a current overview of the Bristow-Latarjet surgery in Brazil. Materials and Methods  This cross-sectional study was based on an electronic questionnaire with 26 items, which was sent to active members of the Brazilian Society of Shoulder and Elbow Surgery (Sociedade Brasileira de Cirurgia do Ombro e Cotovelo, SBCOC, in Portuguese). The questionnaire addressed training, surgical technique, complications, and postoperative management. Results  We sent the questionnaire to 845 specialists from April 20 to May 12, 2021, and 310 of them answered i in full. During their specialization, most specialists participated in up to ten Bristow-Latarjet procedures. The most frequent complication was graft fracture, while the most common technical difficulty was screw positioning. In total, 50.6% and 73.9% reported having experienced intraoperative and postoperative complications respectively; 57.1% declared performing subscapularis suture; 99.7% indicated postoperative immobilization; and 61.9% considered graft consolidation fundamental. Conclusion  Most specialists participated in up to ten Bristow-Latarjet procedures during the specialization, but 13.5% of them graduated without participating in the surgery. The most frequent complication was graft fracture. The most common technical difficulty was screw positioning. Most participants prefer postoperative immobilization since they believe graft consolidation is essential to resume the practiced of sports. The highest complication rate occurred with specialists who have obtained their titles 11 to 15 years ago. In Brazil, the Southeast region is the largest producer of specialists and has the highest concentration of these professionals.

Is sling immobilization necessary after open Latarjet surgery for anterior shoulder instability? A randomized control trial

BACKGROUND

There is a current lack of knowledge regarding optimal rehabilitation and duration of sling immobilization after an open Latarjet procedure. A shift towards immediate self-rehabilitation protocols in shoulder surgery is observed to avoid postoperative stiffness and fasten return to sport. Avoiding sling immobilization could further simplify rehabilitation and provide an even faster return to activities of daily living and enhance patient satisfaction.

METHODS

This study is a single-center, randomized control trial. Sixty-eight patients will be instructed with the same standardized immediate postoperative self-rehabilitation protocol. Patients will be allocated 1:1 between a sling immobilization group for the first three postoperative weeks and no sling group without postoperative immobilization. The primary endpoint will be functional outcome at 6 months postoperative evaluated by the disease-specific Rowe score. Secondary endpoints will include baseline, 1.5-, 6-, and 12-month single assessment numeric evaluation (SANE) of instability score and visual analog pain scale (VAS). At the 6-month time point, graft bony union and position will be assessed by computed tomography. Motion capture technology will evaluate the baseline and 6-month postoperative range of motion. Finally, time to return to work and sport during the first postoperative year, along with patient satisfaction at one postoperative year, will also be recorded.

DISCUSSION

This study will allow further insights into the optimal rehabilitation protocol after open Latarjet surgery and enhance patient care by helping identify rehabilitation and coracoid graft-related factors influencing functional outcomes, bony union, range of motion, and patient satisfaction.

TRIAL REGISTRATION

The protocol was approved by the ethical committee board (CCER 2019-02,469) in April 2020 and by ClinicalTrials.gov (Identifier: NCT04479397 ) in July 2020.

Anterior Glenoid Reconstruction With Distal Tibial Allograft: Biomechanical Impact of Fixation and Presence of a Retained Lateral Cortex

Background:

Glenoid reconstruction with distal tibial allograft (DTA) is a known surgical option for treating recurrent glenohumeral instability with anterior glenoid bone loss; however, biomechanical analysis has yet to determine how graft variability and fixation options alter the torque of screw insertion and load to failure.

Hypothesis:

It was hypothesized that retention of the lateral cortex of the DTA graft and the presence of a washer with the screw will significantly increase the maximum screw placement torque as well as the load to failure.

Study Design:

Controlled laboratory study.

Methods:

Whole, fresh distal tibias were used to harvest 28 DTA grafts, half of which had the lateral cortex removed and half of which had the lateral cortex intact. The grafts were secured to polyurethane solid foam blocks with a 2-mm epoxy laminate to simulate a glenoid with an intact posterior glenoid cortex. Grafts underwent fixation with 4.0-mm cannulated drills, and screws and washers were used for half of each group of grafts while screws alone were used for the other half, creating 4 equal groups of 7 samples each. A digital torque-measuring screwdriver recorded peak torque for screw insertion. Constructs were then tested in compression with a uniaxial materials testing system and loaded in displacement control at 100 mm/min until at least 3 mm of displacement occurred. Ultimate load was defined as the load sustained at clinical failure.

Results:

The use of a washer significantly improved the ultimate torque that could be applied to the screws (+cortex and +washer = 12.42 N·m [SE, 0.82]; –cortex and +washer = 10.54 N·m [SE, 0.59]) (P < .0001), whereas the presence of the native bone cortex did not have a significant effect (+cortex and –washer = 7.83 N·m [SE, 0.40]; –cortex and –washer = 8.03 N·m [SE, 0.56]) (P = .181).

Conclusion:

In a hybrid construct of fresh cadaveric DTA grafts secured to a foam block glenoid model, the addition of washers was more effective than the retention of the lateral distal tibial cortex for both load to failure and peak torque during screw insertion.

Clinical Relevance:

This biomechanical study is relevant to the surgeon when choosing a graft and selecting fixation options during glenoid reconstruction with a DTA graft.

Salvage Iliac Crest Bone Grafting for a Failed Latarjet Procedure: Analysis of Failed and Successful Procedures

BACKGROUND

The Latarjet is a successful procedure but can be associated with significant complications, including failure. Iliac crest bone grafting (ICBG) is one of the salvage options for such failure.

PURPOSE

To analyze factors associated with failure or success to restore shoulder stability with ICBG after Latarjet failure.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Twenty consecutive patients with recurrence of instability after a Latarjet procedure underwent revision using ICBG. Sixteen patients (80%) with a mean age of 35.0 years (range, 25-55) could be personally reexamined clinically and radiographically (including computed tomography scan) after a mean follow-up of 4.5 years (range, 2-8). Twelve patients had redislocation and 4 had recurrent subluxation after the Latarjet.

RESULTS

Salvage ICBG failed in 7 patients because of recurrent dislocations, with 5 necessitating reoperations: 2 arthrodeses, 1 reverse total shoulder arthroplasty, 1 repeat ICBG, and 1 Hill-Sachs allograft reconstruction and Bankart repair. Factors associated with ICBG failure were multidirectional instability (n = 2), subscapularis insufficiency (n = 1), uncontrolled seizures (n = 1), static inferior glenohumeral subluxation (n = 1), total graft resorption (n = 1), and voluntary dislocation attributed to schizoaffective disorder (n = 1). The initial Latarjet graft was malpositioned (too medial) in 3 of these patients. In patients without recurrent instability (n = 9), reasons for Latarjet failure were graft related: 6 graft avulsions, 2 graft resorptions, and 1 medial graft malpositioning. The mean absolute Constant score (62 to 87 points, P = .012) and relative Constant score (66% to 91%, P = .012), pain (10 to 15 points, P < .001), and Subjective Shoulder Value (31% to 85%, P = .011) in the group with a successful procedure were significantly improved over the preoperative state, and the total Western Ontario Shoulder Instability Index averaged 64% at final follow-up. Except in 1 case of major resorption, mild graft resorption or none was observed in successful procedures. Axial and sagittal graft positioning was good in all 9 patients.

CONCLUSIONS

Salvage ICBG for failed Latarjet procedures failed in 7 of 16 patients. It was successful in patients with clearly graft-related factors of the initial Latarjet procedure. However, patients with unclear instability symptoms, subscapularis insufficiency, inferior subluxation, uncontrolled seizures, or psychological disorders were poor candidates for salvage ICBG, underlining the importance of careful patient selection for the initial Latarjet procedure and for salvage ICBG.

A hybrid open-arthroscopic latarjet coracoid bone-block technique using "HyLa" instrumentation

Latarjet coracoid bone-block is a gold-standard procedure for anteroinferior instability of the shoulder. Nowadays, it can be performed as open surgery or entirely under arthroscopy. The pure arthroscopic technique has the advantage of allowing concomitant intra-articular surgery, but involves a long learning curve. Here we present a hybrid concept using dedicated instrumentation comprising a specific guide with or without arthroscopic step, and notably ensuring the safety and reproducibility of the procedure, whatever the modality. This technique offers an alternative to arthroscopic coracoid bone block, performing the more complex steps as open surgery without major change to Latarjet's original technique, so as to enable concomitant intra-articular surgery if needed while getting around some of the limitations of the purely arthroscopic procedure.

Early Follow-Up of Arthroscopic Latarjet Procedure with Screw or Suture-Button Fixation for Recurrent Anterior Shoulder Instability

Objective

To evaluate the early clinical and radiographic results of arthroscopic Latarjet procedure using screw or suture‐button fixation in patients with recurrent anterior shoulder dislocation.

Methods

Twelve patients who underwent arthroscopic Latarjet procedure between January 2015 and December 2018 at our institution were retrospectively studied. Data of the patients' history, including age, gender, side of affected arm, body mass index (BMI), and the number of dislocations since fist dislocation were collected. Preoperative and postoperative clinical follow‐up data were evaluated using Walch–Duplay score, American Shoulder and Elbow Society (ASES) score, and modified Rowe score. Active external rotation and active internal rotation at 90° of abduction as well as active elevation were evaluated preoperatively and postoperatively. The position and healing condition of the transferred coracoid bony graft were also assessed using computed tomography (CT) and Mimics 19.0 software.

Results

Mean follow‐up was 24.9 months (range, 13 to 53 months) of all patients. At final follow‐up, the average ASES score (preoperative vs postoperative values) had improved from 68.9 ± 7.9 to 91.1 ± 6.1 in screw fixation group and 68.9 ± 8.9 to 87.5 ± 6.7 in suture‐button fixation group; the average Rowe score (preoperative vs postoperative values) had improved from 25.0 ± 8.4 to 92.5 ± 4.2 in screw fixation group and 21.7 ± 13.7 to 93.3 ± 4.1 in suture‐button fixation group; the average of Walch–Duplay score (preoperative vs postoperative values) had improved from 12.5 ± 15.1 to 91.7 ± 4.1 in screw fixation group and 18.3 ± 20.7 to 88.3 ± 7.5 in button fixation group. The forward flexion was 175.0° ± 8.4° preoperatively and 178.3° ± 4.1° postoperatively in screw fixation group while 174.8° ± 10.2° preoperatively and 175.0° ± 5.5° postoperatively in suture‐button fixation group. The active external rotation was 77.5° ± 5.2° preoperatively and 71.7° ± 4.1° postoperatively in screw fixation group while 72.5° ± 6.9° preoperatively and 68.3° ± 7.5° postoperatively in suture‐button fixation group. The average of active internal rotation was 66.7° ± 6.1° preoperatively and 67.5° ± 6.1° postoperatively in screw fixation group while 68.3° ± 11.3° preoperatively and 66.7° ± 7.5° postoperatively in suture‐button fixation group. In postoperative CT scan, 91.7% grafts midline center were located at or under the equator in the en face view; 75% of the bone blocks were flush to the glenoid face in the axial view, with only two grafts exhibiting slight medial placement in screw fixation group (33.3%) and one graft exhibiting slight lateral placement in suture‐button fixation group (16.7%). All grafts achieved bone union. Graft absorption mostly occurred outside of the “best‐fit” circle. The average bony absorption rates of the coracoid grafts were 25.2% and 10.18% in screw fixation group and suture‐button fixation group, respectively, at 6 months postoperative follow‐up.

Conclusion

Both suture‐button fixation and screw fixation techniques in arthroscopic Latarjet procedure revealed excellent clinical outcomes with low complication rates in the early follow‐up. The suture‐button fixation exhibited a flexible fixation pattern that allowed for self‐correction to some extent, even slight lateralization could finally remodel over time.