Arthroscopic posterior bone block stabilization-early results of an effective procedure for the recurrent posterior instability

Arthroscopic Posterior Bone Block Procedure With Two Cortical Buttons Fixation and Specific Glenoid Guide for Posterior Shoulder Instability

Arthroscopic posterior bone block procedure using cortical screws has been reported since 2012 for management of recurrent posterior instability associated with bone defects. To avoid screw complications, we describe a full arthroscopic technique based on cortical button fixation. With 4 portals (posterior, poster lateral, anterior, and anterolateral), we use a specific glenoid guiding system (to perform 2 tunnels) and 2 cortical buttons fixation. With a specific glenoid guide, the iliac crest bone graft (ICBG) is secured to the posterior glenoid rim by fixation with 2 cortical buttons. The ICBG is positioned protruding outside the joint through the space, and the posterior capsule is repaired while maintaining an extra-articular bone graft. The protruding bone graft increases the concavity of the glenoid with a progressive bony remodeling to improve the posterior stability of the shoulder in our clinical experience.

Biomechanical Analysis of Posterior Open-Wedge Osteotomy and Glenoid Concavity Reconstruction Using an Implant-Free, J-Shaped Iliac Crest Bone Graft

BACKGROUND

Posterior open-wedge osteotomy and glenoid reconstruction using a J-shaped iliac crest bone graft showed promising clinical results for the treatment of posterior instability with excessive glenoid retroversion and posteroinferior glenoid deficiency.

PURPOSE

To evaluate the biomechanical performance of the posterior J-shaped graft to restore glenoid retroversion and posteroinferior deficiency in a cadaveric shoulder instability model.

STUDY DESIGN

Controlled laboratory study.

METHODS

A posterior glenoid open-wedge osteotomy was performed in 6 fresh-frozen shoulders, allowing the glenoid retroversion to be set at 0°, 10°, and 20°. At each of these 3 preset angles of glenoid retroversion, the following conditions were simulated: (1) intact joint, (2) posterior Bankart lesion, (3) 20% posteroinferior glenoid deficiency, and (4) posterior J-shaped graft (at 0° of retroversion). With the humerus in the Jerk position (60° of glenohumeral anteflexion, 60° of internal rotation), stability was evaluated by measuring posterior humeral head (HH) translation (in mm) and peak translational force (in N) to translate the HH over 25% of the glenoid width. Glenohumeral contact patterns were measured using pressure-sensitive sensors. Fixation of the posterior J-graft was analyzed by recording graft micromovements during 3000 cycles of 5-mm anteroposterior HH translations.

RESULTS

Reconstructing the glenoid with a posterior J-graft to 0° of retroversion significantly increased stability compared with a posterior Bankart lesion and posteroinferior glenoid deficiency in all 3 preset degrees of retroversion (P < .05). There was no significant difference in joint stability comparing the posterior J-graft with an intact joint at 0° of retroversion. The posterior J-graft restored mean contact area and contact pressure comparable with that of the intact condition with 0° of retroversion (222 vs 223 mm2, P = .980; and 0.450 vs 0.550 MPa, P = .203). The mean total graft displacement after 3000 cycles of loading was 43 ± 84 µm, and the mean maximal mediolateral graft bending was 508 ± 488 µm.

CONCLUSION

Biomechanical analysis of the posterior J-graft demonstrated reliable restoration of initial glenohumeral joint stability, normalization of contact patterns comparable with that of an intact shoulder joint with neutral retroversion, and secure initial graft fixation in the cadaveric model.

CLINICAL RELEVANCE

This study confirms that the posterior J-graft can restore stability and glenohumeral loading conditions comparable with those of an intact shoulder.

Open and arthroscopic posterior bone block with iliac crest autograft for posterior shoulder instability - systematic review of clinical and radiological outcomes

INTRODUCTION

Posterior shoulder instability (PSI) is a rare and challenging pathology to manage. The aim of this review was to assess and compare whether open and arthroscopic iliac crest bone graft (ICBG) bone block procedures succeeded in improving functional and clinical outcomes as well as radiological outcomes of union and graft resorption.

HYPOTHESIS

We hypothesised that there will be no difference in recurrence rate and functional outcome between open and arthroscopic procedures but there will be a higher complication rate with open bone block procedures.

METHODS

A systematic review was conducted in accordance with PRISMA guidelines using the online databases MEDLINE and Embase. The review was registered on the PROSPERO database. Studies of open or arthroscopic ICBG bone block procedures reporting patient reported outcome measures, recurrence, complications and progression to osteoarthritis and radiological outcomes of graft union and resorption were selected. Studies were appraised using the Methodical index for non-randomised studies (MINORS) tool.

RESULTS

14 studies satisfied the inclusion criteria; five studies were arthroscopic and nine used open techniques. A total of 183 patients and 201 shoulders were included, mean age was 25 years range (14-75 years). Recurrent instability ranged from 0% to 12.5% for arthroscopic and 0% to 36.4% for open studies. Arthroscopic studies had statistically significant increases in numerous functional outcome scores but there was no evidence for similar improvements in open studies. Osteoarthritis at follow-up ranged from 12.5% to 47% in arthroscopic and 0% to 81.8% for open studies. Arthroscopic complication rate ranged from 6.7% to 75% compared to 0% to 80% for open studies. Majority of complications were metalware related requiring surgical intervention. Partial graft resorption ranged from 7.7-100% after arthroscopic and 4.8-100% after open procedures. High union rates were seen with both open and arthroscopic techniques.

CONCLUSION

This study highlights a lack of high-level evidence for arthroscopic and open posterior bone block procedures using ICBG to manage PSI. Functional and instability outcome scores showed significant improvement with arthroscopic ICBG bone block procedures however limited evidence was available for open studies. Metalwork related complications requiring revision and radiographic progression to osteoarthritis was high in both arthroscopic and open studies.

LEVEL OF EVIDENCE

IV, systematic review.

Arthroscopic Bone Block Procedure for Posterior Shoulder Instability: Updated Surgical Technique

Posterior shoulder instability is generally caused by traumatic posterior dislocations or repetitive microtrauma during sports or other activities and has an annual incidence rate of 4.64 per 100,000 person-years. Several surgical techniques to treat posterior shoulder instability have been described, including soft-tissue repair and both open and arthroscopic bone block procedures. However, even though patient-reported outcomes are commonly high, surgical procedures are associated with high complication and revision rates of up to 14% and 67%, respectively. In particular, accurate placement of the bone graft, screw orientation, and the treatment of concomitant lesions are considered challenging. Therefore, improvement of surgical techniques is desirable. This Technical Note describes an updated approach to the arthroscopic posterior bone block augmentation described by Lafosse et al. (2012), with tips and tricks on the harvest and positioning of the graft.

Comprehensive management of posterior shoulder instability: diagnosis, indications, and technique for arthroscopic bone block augmentation

Recurrent posterior glenohumeral instability is an entity that demands a high clinical suspicion and a detailed study for a correct approach and treatment. Its classification must consider its biomechanics, whether it is due to functional muscular imbalance or to structural changes, volition, and intentionality.

Due to its varied clinical presentations and different structural alterations, ranging from capsule-labral lesions and bone defects to glenoid dysplasia and retroversion, the different treatment alternatives available have historically had a high incidence of failure.

A detailed radiographic assessment, with both CT and MRI, with a precise assessment of glenoid and humeral bone defects and of glenoid morphology, is mandatory.

Physiotherapy focused on periscapular muscle reeducation and external rotator strengthening is always the first line of treatment. When conservative treatment fails, surgical treatment must be guided by the structural lesions present, ranging from soft tissue repair to posterior bone block techniques to restore or increase the articular surface.

Bone block procedures are indicated in cases of recurrent posterior instability after the failure of conservative treatment or soft tissue techniques, as well as symptomatic demonstrable nonintentional instability, presence of a posterior glenoid defect >10%, increased glenoid retroversion between 10 and 25°, and posterior rim dysplasia. Bone block fixation techniques that avoid screws and metal allow for satisfactory initial clinical results in a safe and reproducible way.

An algorithm for the approach and treatment of recurrent posterior glenohumeral instability is presented, as well as the author’s preferred surgical technique for arthroscopic posterior bone block.

Bone Block Augmentation of the Posterior Glenoid for Recurrent Posterior Shoulder Instability Is Associated With High Rates of Clinical Failure: A Systematic Review

PURPOSE

To determine whether posterior glenoid bone block augmentation performed for the treatment of recurrent posterior shoulder instability succeeds in restoring stability and is associated with rates of complications or clinical failures comparable to other glenoid bone augmentation procedures.

METHODS

A comprehensive search of PubMed, MEDLINE, and EMBASE databases was performed. Level of evidence studies I to IV pertaining to posterior bone block augmentation reporting on outcomes or complications were included. The search was carried out in accordance with the Preferred Reported Items for Systematic Reviews and Meta-analyses guidelines.

RESULTS

Screening of titles, abstracts, and manuscripts with application of inclusion and exclusion criteria yielded 17 full-text articles reporting on 269 shoulders undergoing bone block augmentation. Surgical technique varied between studies with regard to graft type (iliac crest, 13 studies; scapular spine, 2; acromion, 1; distal tibia allograft, 1), graft positioning (medial to 1.5 cm lateral to glenoid surface, equatorial to subequatorial), and open versus arthroscopic technique (open, 10 studies; arthroscopic, 4; both, 3). Four of the 8 studies with pre- and postoperative patient-reported outcomes (PROs) showed significant improvements in these outcomes at final follow-up. The postoperative outcomes ranged from 60 to 90 for Rowe scores (n = 7 studies) and 79 to 90 for Walch-Duplay scores (n = 7 studies). Complications were commonly encountered, with high rates of recurrent instability (0% to 73%) and revision procedures (0% to 67%) across different studies.

CONCLUSION

Posterior bone block augmentation for recurrent posterior shoulder instability does not reliably yield substantial improvements in PROs, and complications are frequently observed. The substantial heterogeneity across studies and the small number of patients precludes any substantive judgements as to the superiority of one surgical technique over another.

LEVEL OF EVIDENCE

IV, systematic review of level III and IV studies.

Posterior glenoid bone block transfer for posterior shoulder instability: a systematic review

BACKGROUND

The purpose of this study is to systematically review the literature and evaluate patient-reported outcomes and complication/revision rates of bone block augmentation in the treatment of posterior shoulder instability (PSI).

METHODS

PubMed was searched according to PRIMSA guidelines to find clinical studies evaluating patient-reported outcomes, revision, and complication rates in posterior bone block for PSI. A literature search of MEDLINE, EMBASE, and the Cochrane Library was performed based on the PRISMA guidelines. Clinical studies reporting on the complications following posterior bone block were included.

RESULTS

Overall, 11 studies (level of evidence [LOE] III: 2, LOE IV: 9) met inclusion criteria, with 225 shoulders. Recurrent instability after the posterior bone block was found to be 9.8%. The overall complication rate was 13.8%, with 0.89% having graft complications, 11.1% having hardware complications, 0.4% having wound complications, 0.4% having nerve complications, and 0.89% having other complications. Residual pain was found in 11.6% of shoulders operated on. Patient-reported outcomes were evaluated most commonly by Rowe (81.4%), Constant (84.6%), and Walch-Duplay scores (81.6%).

CONCLUSION

There is a moderate rate of recurrence following posterior bone block for PSI. However, the patient-reported outcomes are high despite there being commonly reported persistent shoulder pain postoperatively.

Posterior Open-wedge Osteotomy and Glenoid Concavity Reconstruction Using an Implant-free, J-shaped Iliac Crest Bone Graft in Atraumatic Posterior Instability with Pathologic Glenoid Retroversion and Dysplasia: A Preliminary Report

BACKGROUND

Atraumatic posterior shoulder instability in patients with pathologic glenoid retroversion and dysplasia is an unsolved problem in shoulder surgery.

QUESTIONS/PURPOSES

In a preliminary study of a small group of patients with atraumatic posterior shoulder instability associated with glenoid retroversion ≥ 15° and glenoid dysplasia who underwent posterior open-wedge osteotomy and glenoid concavity reconstruction using an implant-free, J-shaped iliac crest bone graft, we asked: (1) What proportion of the patients had persistent apprehension? (2) What were the improvements in patient-reported shoulder scores? (3) What were the radiographic findings at short-term follow-up?

METHODS

Between 2016 and 2018, we treated seven patients for atraumatic posterior shoulder instability. We performed this intervention when posterior shoulder instability symptoms were unresponsive to physiotherapy for at least 6 months and when it was associated with glenoid retroversion ≥ 15° and dysplasia of the posteroinferior glenoid. All seven patients had a follow-up examination at a minimum of 2 years. The median (range) age at surgery was 27 years (16 to 45) and the median follow-up was 2.3 years (2 to 3). Apprehension was assessed by a positive posterior apprehension and/or posterior jerk test. Patient-reported shoulder scores were obtained and included the subjective shoulder value, obtained by chart review (and scored with 100% representing a normal shoulder; minimum clinically important difference [MCID] 12%), and the Constant pain scale score (with 15 points representing no pain; MCID 1.5 points). Radiographic measurements included glenohumeral arthropathy and posterior humeral head subluxation, bone graft union, correction of glenoid retroversion and glenoid concavity depth, as well as augmentation of glenoid surface area. All endpoints were assessed by individuals not involved in patient care.

RESULTS

In four of seven patients, posterior apprehension was positive, but none reported resubluxation. The preoperative subjective shoulder value (median [range] 40% [30% to 80%]) and Constant pain scale score (median 7 points [3 to 13]) were improved at latest follow-up (median subjective shoulder value 90% [70% to 100%]; p = 0.02; median Constant pain scale score 15 points [10 to 15]; p = 0.03). Posterior glenoid cartilage erosion was present in four patients (all four had Walch Type B1 glenoids) preoperatively and showed no progression until the final follow-up examination. The median (range) humeral head subluxation index decreased from 69% (54% to 85%) preoperatively to 55% (46% to 67%) postoperatively (p = 0.02), and in two of four patients with preoperative humeral head subluxation (> 65% subluxation), it was reversed to a centered humeral head. CT images showed union in all implant-free, J-shaped iliac crest bone grafts. The median preoperative retroversion was corrected from 16° (15° to 25°) to 0° postoperatively (-5° to 6°; p = 0.02), the median glenoid concavity depth was reconstructed from 0.3 mm (-0.7 to 1.6) preoperatively to 1.2 mm (1.1 to 3.1) postoperatively (p = 0.02), and the median preoperative glenoid surface area was increased by 20% (p = 0.02). No intraoperative or postoperative complications were recorded, and no reoperation was performed or is planned.

CONCLUSION

In this small, retrospective series of patients treated by experienced shoulder surgeons, a posterior J-bone graft procedure was able to reconstruct posterior glenoid morphology, correct glenoid retroversion, and improve posterior shoulder instability associated with pathologic glenoid retroversion and dysplasia, although four of seven patients had persistent posterior apprehension. Although no patients in this small series experienced complications, the size and complexity of this procedure make it likely that as more patients have it, some will develop complications; future studies will need to characterize the frequency and severity of those complications, and we recommend that this procedure be done only by experienced shoulder surgeons. The early results in these seven patients justify further study of this procedure for the proposed indication, but longer term follow-up is necessary to continue to assess whether it is advantageous to combine the reconstruction of posterior glenoid concavity with correction of pathological glenoid retroversion and increasing glenoid surface compared with traditional surgical techniques such as the posterior opening wedge osteotomy or simple posterior bone block procedures.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Anterior and posterior glenoid bone augmentation options for shoulder instability: state of the art

Bony lesions are highly prevalent in anterior shoulder instability and can be a significant cause of failure of stabilisation procedures if they are not adequately addressed. The glenoid track concept describes the dynamic interaction between the humeral head and glenoid defects in anterior shoulder instability. It has been beneficial for understanding the role played by bone defects in this entity. As a consequence, the popularity of glenoid augmentation procedures aimed to treat anterior glenoid bone defects; reconstructing the anatomy of the glenohumeral joint has risen sharply in the last decade. Although bone defects are less common in posterior instability, posterior bone block procedures can be indicated to treat not only posterior bony lesions, attritional posterior glenoid erosion or dysplasia but also normal or retroverted glenoids to provide an extended glenoid surface to increase the glenohumeral stability. The purpose of this review was to analyse the rationale, current indications and results of surgical techniques aimed to augment the glenoid surface in patients diagnosed of either anterior or posterior instability by assessing a thorough review of modern literature. Classical techniques such as Latarjet or free bone block procedures have proven to be effective in augmenting the glenoid surface and consequently achieving adequate shoulder stability with good clinical outcomes and early return to athletic activity. Innovations in surgical techniques have permitted to perform these procedures arthroscopically. Arthroscopy provides the theoretical advantages of lower morbidity and faster recovery, as well as the identification and treatment of concomitant pathologies.

Acceptable Long-Term Outcomes of Arthroscopic Bone Grafting for Recurrent Posterior Shoulder Instability: Minimum Follow-Up of 5 Years

PURPOSE

To examine the long-term clinical outcome associated with arthroscopically placed autologous iliac crest bone graft (ICBG) for recurrent posterior shoulder instability.

METHODS

From January 2008 to December 2013, patients treated with posterior ICBG and a minimum follow-up of 5 years were included. Clinical outcome of patients operated with a posterior ICBG was analyzed with multiple patient-reported outcome measures included Constant (CS), American Shoulder and Elbow Surgeons (ASES), Walch-Duplay, and Rowe scores, shoulder subjective value, and pain visual analog score. Patient satisfaction was assessed by asking the patients their overall level of satisfaction at last follow-up on a 1 to 10 scale.

RESULTS

In total, 18 patients (19 shoulders) were included. At a mean follow-up of 7.3 years (range, 5-10 years), patients had significant improvements in their mean CS from 63 (standard deviation [SD] 18) to 80 (SD 18; P = .005), ASES from 57 (SD 18) to 81 (SD 18; P = .003), Walch-Duplay from 34 (SD 31) to 79 (SD 22; P < .001), and Rowe score from 37 (SD 23) to 79 (SD 24; P < .001). Pain level decreased from 5.6 (SD 2.5) preoperative to 2.3 (SD 2.3; P < .001) and shoulder subjective value improved 58 (SD 20) to 76 (SD 24; P = .002). Global satisfaction with the procedure was 8.4 (SD 2.1). Clinical significance was met or exceeded by 84% for CS and 89% of the patients for ASES and 95% met or exceeded satisfaction threshold for CS. There were 7 shoulders (37%) reoperated for symptomatic screw irritation.

CONCLUSIONS

This series reporting on the long-term follow-up after arthroscopic posterior ICBG for recurrent posterior shoulder instability demonstrates, despite a high number of reoperations for symptomatic screw irritation, its effectiveness with acceptable clinical outcomes and satisfied patients.

LEVEL OF EVIDENCE

IV, therapeutic case series.

Arthroscopic Posterior Glenoid Reconstruction Using a Fresh Distal Tibia Allograft for Recurrent Posterior Instability

Posterior glenohumeral instability is a relatively uncommon cause of shoulder instability. Recurrent posterior instability with static posterior humeral head subluxation is often associated with critical glenoid bone loss. Unlike anterior instability, the amount of bone loss for posterior instability that requires surgical reconstruction remains a topic of debate. Several techniques have been described to treat critical bony defects in patients with recurrent posterior shoulder instability with the use of both autografts and allografts depending on the amount of bone loss present. Open posterior glenoid bone block procedure is associated with increased risk of complications and morbidity to the patient. As such, all-arthroscopic techniques have emerged with the advantage of allowing for the diagnosis and treatment of concomitant glenohumeral pathology and minimizing soft-tissue dissection through the posterior deltoid and rotator cuff muscles. Reported short-term outcomes of arthroscopic posterior bone block stabilization are promising; however, it remains a technically challenging procedure due to intra-articular graft insertion and subsequent fixation congruent to the posterior glenoid articular margin. We describe an all-arthroscopic technique using a fresh distal tibia allograft fixation using 2 partially threaded screws in conjunction with an arthroscopic Latarjet fixation set for a patient with recurrent posterior shoulder instability and associated glenoid bone loss.

Restoration of the Posterior Glenoid in Recurrent Posterior Shoulder Instability Using an Arthroscopically Placed Iliac Crest Bone Graft: A Computed Tomography-Based Analysis

Background

Posterior shoulder instability is uncommon, and its treatment is a challenging problem. An arthroscopically assisted technique for posterior iliac crest bone grafting (ICBG) has shown promising short- and long-term clinical results. Changes as shown on imaging scans after posterior ICBG for posterior shoulder instability have not been investigated in the recent literature.

Purpose

To evaluate changes on computed tomography (CT) after arthroscopically assisted posterior ICBG and to assess clinical outcomes.

Study Design

Case series; Level of evidence, 4.

Methods

Patients with preoperative CT scans and at least 2 postoperative CT scans with a minimum follow-up of 2 years were included in the evaluation. Of 49 initial patients, 17 (follow-up rate, 35%) met the inclusion criteria and were available for follow-up. We measured the glenoid version angle and the glenohumeral and scapulohumeral indices on the preoperative CT scans and compared them with measurements on the postoperative CT scans. Postoperatively, graft surface, resorption, and defect coverage were measured and compared with those at early follow-up (within 16 months) and final follow-up (mean ± SD, 6.6 ± 2.8 years).

Results

The mean preoperative glenoid version was -17° ± 13.5°, which was corrected to -9.9° ± 11.9° at final follow-up (P < .001). The humeral head was able to be recentered and reached normal values as indicated by the glenohumeral index (51.8% ± 6%; P = .042) and scapulohumeral index (59.6% ± 10.2%; P < .001) at final follow-up. Graft surface area decreased over the follow-up period, from 24% ± 9% of the glenoid surface at early follow-up to 17% ± 10% at final follow-up (P < .001). All clinical outcome scores had improved significantly. Progression of osteoarthritis was observed in 47% of the shoulders.

Conclusion

Arthroscopically assisted posterior ICBG restored reliable parameters as shown on CT scans, especially glenoid version and the posterior subluxation indices. Graft resorption was common and could be observed in all shoulders. Patient-reported clinical outcome scores were improved. Osteoarthritis progression in almost 50% of patients is concerning for the long-term success of this procedure.

Posterior bony Bankart bridge technique results in reliable clinical 2-year outcomes and high return to sports rate for the treatment of posterior bony Bankart lesions

PURPOSE

To introduce the arthroscopic "posterior bony Bankart bridge" repair technique, and to report clinical outcomes, patient satisfaction, recurrent instability rate, and return to sport rate.

METHODS

Patients who were treated for posterior bony Bankart lesions with posterior bony Bankart bridge technique and were at least 2 years out from surgery were included. Clinical outcomes were assessed prospectively by the use of the American Shoulder and Elbow Surgeons (ASES) Score, Single Assessment Numerical Evaluation (SANE) Score, Quick Disabilities of the Arm, Shoulder and Hand (DASH) Score and patient satisfaction. Return to sports rate and complications were reported.

RESULTS

Seven patients with a median age of 23.5 (range 17-43) and a median follow-up of 8 years (range 3-10) were included. Median time from injury to surgery was 15 days (range 3 days-2.2 years). Mean glenoid bone defect was 19% (range 11-31%). At final follow-up the median postoperative outcome scores were: ASES score 100 (range 92-100), SANE score 99 points (range 94-99) and QuickDASH 2.2 points (range 0-9). Median satisfaction of all patients was 10/10 (range 9-10). One patient reported subjective recurrent subluxations, which resolved under physical therapy. No patient underwent further surgery. No complications were noticed. At final follow-up, all patients (100%) reported that their sports participation levels were equal to their pre-injury levels.

CONCLUSION

The arthroscopic posterior bony Bankart bridge technique leads to reliable postoperative shoulder function and restores shoulder stability with high patient satisfaction and low complication rate in this small patient cohort for the treatment of posterior bony Bankart lesions. Also, no recurrent dislocation was observed at a minimum follow-up of at least 3 years, one patient continued to complain of subjective subluxations which resolved under physical therapy. All patients were able to return to their pre-injury sports level.

LEVEL OF EVIDENCE

Case series, Level IV.

Distal Tibial Allograft Augmentation for Posterior Shoulder Instability Associated With Glenoid Bony Deficiency: A Case Series

Purpose

To report the clinical history and preliminary outcomes of patients who underwent posterior glenoid reconstruction using a distal tibial allograft (DTA) for the management of posterior shoulder instability with glenoid bone loss.

Methods

Patients who underwent posterior shoulder stabilization with a DTA in our institution between 2011 and 2019 were retrospectively reviewed. Demographic characteristics, operative reports, and clinical and functional outcomes were recorded. Outcomes included postoperative range of motion (ROM), recurrent instability, complications, and revision surgery. All patients underwent at least 1 year of follow-up, except 2 patients who underwent revision surgery. Preoperative and postoperative ROM was compared using the 2-tailed Student t test for paired samples.

Results

Ten patients who underwent DTA augmentation for posterior instability were included, comprising 2 female and 8 male patients with an average age of 24 years (range, 17-35 years). Five patients had a prior sports-related traumatic event, and 2 patients had a seizure disorder. Seven patients had undergone a prior stabilization procedure. The average reverse bony Bankart lesion was 26% of the glenoid diameter. Concomitant procedures included 4 capsular repairs, 2 labral repairs, 2 capsular plications, and 1 repair for humeral avulsion of the glenohumeral ligament. One patient reported recurrent instability after surgery. Two patients underwent revision surgery, with one removal of symptomatic hardware and one early revision owing to screw penetration into the glenoid. There was no significant difference in preoperative versus postoperative ROM.

Conclusions

Posterior shoulder instability with significant bony deficiency can be managed using DTA augmentation with good outcomes and a reasonable complication rate in these challenging cases.

Level of Evidence

Level IV, case series.

Posterior Glenoid Augmentation With Extra-articular Iliac Crest Autograft for Recurrent Posterior Shoulder Instability

Several techniques have been described for bone block augmentation as a treatment for posterior shoulder instability, including intra-articular distal tibial allograft and extra-articular iliac crest autograft. Although indications are not yet well defined, these bone augmentation procedures are considered in patients with glenoid bone loss, increased glenoid retroversion, previous failed posterior soft-tissue repair, and insufficient posterior capsulolabral tissue. In patients with posterior glenoid bone loss, the senior author (P.J.M.) recommends intra-articular glenoid reconstruction with a fresh distal tibial osteoarticular allograft. In patients with insufficient posterior capsulolabral tissue, the senior author prefers an extra-articular iliac crest autograft to buttress the posterior soft-tissue restraints. This technique guide outlines extra-articular iliac crest autograft treatment for recurrent posterior shoulder instability in patients with insufficient posterior soft tissues due to prior failed surgery. After an open capsulolabral repair is performed using suture anchors, the bone block is placed extra-articularly on the posterior glenoid neck.

Arthroscopic "Bone Block Cerclage" Technique for Posterior Shoulder Instability

Many open and arthroscopic techniques have been described to treat posterior glenohumeral instability. Multifactorial features of posterior shoulder instability pathoanatomy and varied patient characteristics have challenged the understanding of this condition and have led to dissimilar results, without a strong consensus for the most adequate technique to treat it. We describe an arthroscopic anatomical metal-free posterior glenoid reconstruction technique, using a tricortical iliac crest allograft with 2 ultra-high strength sutures (FiberTape Cerclage System; Arthrex, Naples, FL) with concomitant posterior capsulolabral complex reconstruction procedure.

No difference in outcomes of surgical treatment for traumatic and atraumatic posterior shoulder instability

BACKGROUND

Posterior shoulder instability is a rare pathology and accounts for 2-10% of all shoulder instabilities. The purpose of this study was to compare pain and functional scores following surgical treatment of traumatic and atraumatic PSI.

HYPOTHESIS

The authors hypothesize that patients with traumatic PSI are at greater risks of residual pain and recurrent subluxation.

MATERIAL AND METHODS

The records of 150 patients operated for PSI between 2000 and 2015 at 10 different centers were analysed. Inclusion criteria were symptomatic PSI (subluxation and/or pain) with radiographic signs of posterior glenoid erosion or fracture, posterior labral tears, or reverse Hill Sachs lesions. One hundred and seventeen patients were eligible, of which 84% presented symptoms of subluxation and/or dislocation, and 16% were painful without clinical symptoms of subluxation and/or dislocation. Patients were evaluated at 48±33months (range: 12-159) using the Constant, Walch-Duplay and Rowe scores, with pain on Visual Analogic Scale (pVAS).

RESULTS

Compared to atraumatic PSI, traumatic PSI was more prevalent in men (84.4% vs 61.9%, p=0.031), and tended to have fewer pain symptoms (15.8% vs 23.8%, n.s). Atraumatic PSI was more likely to affect the dominant arm, although the difference was not significant (81.0% vs 59.4%, n.s.). Traumatic PSI did not differ from atraumatic PSI in terms of preoperative lesional characteristics, procedures performed, or postoperative pain and instability. Although these differences were not statistically significant, it is worth noting that traumatic PSI patients experienced more recurrence of instability (15.6% vs 4.8%, p=0.298), and lower pain on VAS (1.5±2.3 vs 2.6±3.0, n.s.) compared to atraumatic PSI.

DISCUSSION

Functional scores did not significantly differ between traumatic and atraumatic PSI after surgery, although traumatic PSI patients tended to have a higher recurrence of instability, while atraumatic PSI patients tended to remain more painful.

LEVEL OF EVIDENCE

IV, retrospective cohort study.