"Postage Stamp" Fractures: A Systematic Review of Patient and Suture Anchor Profiles Causing Anterior Glenoid Rim Fractures After Bankart Repair

The process of bone union after arthroscopic bony Bankart repair in younger athletes with a subcritical glenoid defect: An advantage of remained large bone fragment

BACKGROUND

The purpose of the present study was to investigate the bone union process after arthroscopic bony Bankart repair (ABBR) in shoulders with a subcritical glenoid defect of 13.5% or larger.

METHODS

Bone union process after ABBR performed from 2011 to 2018 were retrospectively investigated in 47 athletes younger than 30 years with a subcritical glenoid defect, who underwent CT at least twice postoperatively. The change of bone union between first CT within 6 months and final CT later than 6 months was investigated, especially noticing bone fragment size (≥7.5% versus <7.5%).

RESULTS

The mean period at first CT and at final CT was 4.1 ± 0.6 months (3-6 months) and 16.8 ± 11.6 months (7-71 months), respectively. From the first to final CT, among 15 shoulders with a small bone fragment (<7.5%), complete union increased from 4 shoulders (26.7%) to 8 shoulders (53.3%), while among 32 shoulders with a large bone fragment (≥7.5%), complete union increased from 15 shoulders (46.9%) to 25 shoulders (78.1%). On the other hand, while non-union or disappeared bone fragment was recognized in 8 shoulders (53.3%) with a small fragment and in 2 shoulders (6.3%) with a large fragment at first CT, it was solely recognized in 4 shoulders (26.7%) with a small fragment and in no shoulders with a large fragment at final CT. While postoperative glenoid fracture at the site of bone union was recognized in 7 shoulders, complete union was finally obtained after conservative treatment in 5 shoulders. So, final complete union was obtained in 9 (60%) of 15 shoulders with a small fragment and in 29 (90.6%) of 32 shoulders with a large fragment (p = 0.021).

CONCLUSIONS

In shoulders with a subcritical glenoid defect, when a large bone fragment (≥7.5%) was repaired, complete union rate was higher and complete union could be obtained earlier.

How many anchors to use in arthroscopic Bankart repairs? A biomechanical study of postage-stamp glenoid fractures

BACKGROUND

Deciding how many anchors to use in a Bankart repair is challenging because of the desire to enhance stability while avoiding a postage-stamp fracture of the glenoid rim.

METHODS

This controlled laboratory study investigated load to fracture of the anterior glenoid rim after drilling holes of varying number and diameter and inserting anchors of 2 different types and sizes, with and without perforation of the medial cortex of the glenoid, creating postage-stamp fractures using a metallic humeral head that was compressed against the anterior glenoid rim. A destructive model with a servohydraulic load frame was used to test 46 synthetic scapulae with compressive strength and elastic modulus similar to that of a human glenoid. Load to fracture of the intact glenoid was compared with groups with a varying number of anchor holes of different diameters, with anchors of different sizes and types, and with anchors perforating or not perforating the glenoid medial cortex. The percentage of force to fracture an intact specimen was used to identify relative risk of fracture: low risk >75%, moderate risk 75%-50%, and high risk <50% of intact load.

RESULTS

The load to fracture of intact glenoids was 1276 ± 42 N. Loads decreased linearly as the number of holes drilled on the glenoid rim increased. Compared with the 1.6-mm group, the 3.0-mm group had significantly lower glenoid rim strength in specimens with 4, 5, and 7 holes (P = .013, .032, and .045, respectively). All-suture anchors in 1.6-mm holes did not alter the glenoid rim strength, and up to 5 anchors were associated with low risk of fracture. Load to fracture was significantly higher with 3.0-mm rigid core bioabsorbable anchors with 4 anchors (1081 ± 6 N) compared with the 4-hole condition (838 ± 107 N; P = .033). Perforating the glenoid medial cortex with five 1.6-mm anchors significantly weakened the glenoid rim to 58% of intact (P = .012). Perforating the medial cortex weakened the glenoid rim to 52% and 42% (P < .001 for both) of intact in the 3.0-mm 4-anchor and 5-anchor constructions, constituting moderate and high risk of fracture, respectively.

CONCLUSION

Up to five 1.6-mm all-suture anchors and four 3.0-mm bioabsorbable rigid-core anchors were associated with low risk of fracture of the glenoid rim. Smaller diameter all-suture anchors best preserved structural integrity of the glenoid rim, whereas tunnel enlargement and perforation of the glenoid medial cortex were associated with moderate or high risk of a postage-stamp fracture.

Open reduction and internal fixation of Ideberg type IA glenoid fractures: Tricks, pearls, and potential pitfalls based on a retrospective cohort of 33 patients focusing on the rehabilitation protocol

INTRODUCTION

The standard treatment of anterior glenaoid fractures carrying > 20% of the glenoid fossa is open reduction and internal fixation (ORIF). In the herein study, we report our outcomes in a retrospective cohort of anterior and anteroinferior glenoid rim fractures using an accelerated postoperative rehabilitation protocol. A secondary aim is to describe the surgical steps for ORIF of anterior and anteroinferior glenoid rim fractures using the anterior axillary approach, describing the tricks, pearls, and pitfalls of this surgical technique.

METHODS

A retrospective cohort of skeletally mature patients treated for an anterior glenoid rim fracture carrying > 20% of the glenoid fossa during a 10-year period were operated on using a vertical axillary incision, osteosynthesis with 2.0-mm cortical screws, and labral repair with small diameter metallic anchors and non-absorbable sutures. Rehabilitation began on the first postoperative day, including passive external rotation exercises and active-assisted flexion, adduction, and abduction exercises as tolerated. The exercises are performed with the patient sitting or lying down. Phase 1 is continued for 6-10 weeks until the patient regains painless, normal, or near-normal ROM. Usually by 10 weeks, the fracture and labrum are healed, so phase 2 rehabilitation begins with strengthening and ROM exercises. Radiologic and clinical outcomes, including active range of motion (ROM), glenohumeral stability, and visual analogue scale (VAS) were measured.

RESULTS

About 33 patients (35 fractures) had complete medical records and pre- and post-operative imaging exams available for further analysis regarding the surgical protocol, with a mean of 4.8 years. The mean DASH questionnaire was 3.75 ± 9.0 and the mean CM score was 62.5 ± 0.1. Active flexion and internal rotation were recovered in all patients, while external rotation presented an average loss of 8° (p = 0.12) and abduction of 5° (p = 0.33). The mean VAS was 1.1 ± 0.8. No patient reported major or disabling symptoms, or great difficulty or inability to perform daily or recreational activities. No patient presented residual instability of the glenohumeral joint.

CONCLUSION

In this retrospective cohort, ORIF using a vertical axillary incision, osteosynthesis with 2.0-mm screws, and labral repair with small diameter metallic anchors and non-absorbable sutures was a safe approach, with a minimal risk of complications and residual instability. The accelerated postoperative rehabilitation protocol, allowing immediate passive external rotation of the operated shoulder, resulted in a non-significant loss of ROM compared to the contralateral side. Therefore, we recommend this management strategy for anterior glenoid rim fractures in patients with unstable shoulder joint after traumatic glenohumeral dislocation.

LEVEL OF EVIDENCE IV

Therapeutic Study (Surgical technique and Retrospective cohort).

Latarjet Procedure to Restore Glenohumeral Stability in a Patient With a Postage Stamp Fracture

The "postage stamp fracture" is an anterior glenoid rim fracture following arthroscopic repair of a Bankart lesion. Often occurring at the time of an acute trauma, a fracture line propagates though the previous Bankart repair anchor sites, resulting in recurrent anterior instability of the glenohumeral joint. The resultant glenoid rim fracture edge gives a similar appearance as the edge of a stamp, with the osseous edge having the classic "perforation" pattern. When patients present with a postage stamp fracture, even in the setting of subcritical glenoid bone loss, we believe that additional soft-tissue stabilization procedures and/or fracture fixation pose a significant risk of failure. In our opinion, a Latarjet procedure is recommended in a majority of patients with a postage stamp fracture for restoration of glenohumeral stability. The procedure offers a reliable, reproducible surgical intervention that controls for many of the factors that can make arthroscopic revision unreliable, such as poor bone quality, adhesions, labral degeneration, and bone loss. Here, we outline our preferred surgical technique to restore glenohumeral stability using the Latarjet procedure for a patient with a postage stamp fracture.

Editorial Commentary: Anchor Position Affects Glenoid Resorption Rates After Arthroscopic Bankart Repair: Shoulder Stabilization Surgery Is a Game of Millimeters

The technical nuances of arthroscopic Bankart repair cannot be overstated. Previous literature has identified a number of risk factors for failure of arthroscopic stabilization procedures, and the implications of glenoid bone loss is widely recognized as a critical driver of postoperative outcomes. However, other technical considerations (inadequate number of suture anchors, improper position of suture anchors) have been acknowledged as risk factors for the failure of arthroscopic stabilization procedures. More recently, concerns have been raised regarding the observed rates of glenoid bone resorption following arthroscopic Bankart repair, which theoretically may predispose higher rates of clinical failure. Furthermore, certain techniques for placing anchors on the glenoid during arthroscopic Bankart repair may accelerate these resorptive changes. Precise measures of poststabilization surgery glenoid resorption coupled with comprehensive assessments of clinical outcomes are required to determine the optimal technique for anchor insertion during arthroscopic Bankart repair.

Arthroscopic Bankart repair with all-suture anchors does not cause important glenoid bone osteolysis: a volumetric CT study of 143 anchors

PURPOSE

To evaluate with computed tomography (CT) the incidence of anchor-related osteolysis after implantation of two types of all-suture anchors for the management of labral lesions in shoulder instability.

METHODS

Single-cohort, observational study with 12-month follow-up. Thirty-three participants (27 males/6 females; age 38.3 years [SD 11.3]) with anterior labral lesions in which 143 all-suture anchors (71 Iconix 1.4 mm and 72 Suturefix 1.7 mm) were implanted were evaluated with a CT performed a mean of 15.4 [3.85] months after surgery. The volume of the bone defects was measured in the CT. Every anchor was classified into one of four groups: (1) no bone defect. (2) Partial bone defect (defects smaller than the drill used for anchor placement). (3) Tunnel enlargement (defects larger than the drill volume but smaller than twice that volume). (4) Cystic lesion (defects larger than twice the drill volume).

RESULTS

No bone defect was identified in 16 anchors (11.2%, [95% CI 6.5-17.5%]). A partial bone defect was found in 84 anchors (58.7% [50.2-66.9%]). Tunnel enlargement was found in 43 anchors (30.11% [22.6-37.6%]). No anchor caused cystic lesions (0% [0-2.5%]). The defect volume was a mean of 27.8 mm³ (SD 18.4 mm³, minimum 0 mm³, maximum 94 mm³). Neither the position in the glenoid nor the type of implant used had a significant effect in the type or size of the defects.

CONCLUSION

When using all-suture anchors in the glenoid during instability surgery, relevant bone osteolytic defects are rare at 1-year follow-up. Most anchor insertion tunnels will fill completely (11%) or partially (59%) with bone. Tunnel enlargement will develop in 30% of anchors. No cystic defects larger than 0.125 cm³ were observed. There is a low risk that all-suture anchors cause significant osteolytic bone defects in the glenoid. These implants can be used safely. Level of evidence IV.

Diagnosis and Management of Traumatic Anterior Shoulder Instability

Anterior shoulder instability is the most common form of shoulder instability and is usually because of a traumatic injury. Careful patient selection is key to a favorable outcome. Primary shoulder stabilization should be considered for patients with high risk of recurrence or for elite athletes. Soft-tissue injury to the labrum, capsule, glenohumeral ligament, and rotator cuff influence the outcome. Glenoid bone loss (GBL) and type of bone loss (on-track/off-track) are important factors when recommending treatment strategy. Identification and management of concomitant injuries are paramount. The physician should consider three-dimensional CT reconstructions and magnetic resonance arthrography when concomitant injury is suspected. Good results can be expected after Bankart repair in on-track Hill-Sachs lesions (HSLs) with GBL < 13.5%. Bankart repair without adjunct procedures is not recommended in off-track HSLs, regardless of the size of GBL. If GBL is 13.5% to 25% but on-track, adjunct procedures to Bankart repair should be considered (remplissage and inferior capsular shift). Bone block transfer is recommended when GBL > 20% to 25% or when the HSL is off-track. Fresh tibia allograft or lilac crest autograft are good treatment options after failed bone block procedure.

The Arthroscopic Bankart Repair: State of the Art in 2020: Decision-making and Operative Technique

Traumatic anterior shoulder instability is prevalent among young athletes, and recurrent dislocations can result in compromised upper extremity function, increasing glenohumeral bone loss, and ultimately, posttraumatic arthritis. Although management algorithms have evolved in response to contemporary data and technical innovation, the arthroscopic Bankart repair continues to be a mainstay for the primary surgical management of first-time or recurrent anterior shoulder instability with marginal attritional glenoid bone loss (ie, <10% to 15%) and/or "on track" Hill-Sachs defects. The advantages of arthroscopic stabilization include its minimally invasive technique, high cost effectiveness, and relatively low recurrence rates and propensity for perioperative complications. The current article reviews contemporary indications/contraindications, management of the first-time dislocator, critical glenoid bone loss, surgical technique, and reported clinical outcomes of the arthroscopic Bankart repair.

Editorial Commentary: Is Arthroscopic Bankart Repair Using Suture Anchors on the Glenoid Appropriate Treatment for Traumatic Anterior Shoulder Instability?

Fracture of the anterior glenoid rim along the sites of suture anchor insertion is not rare after arthroscopic Bankart repair for traumatic anterior shoulder instability. In addition to the influence of the number, type, and size of the suture anchors, placing multiple anchors in a linear arrangement might impose excessive stress on the surrounding bone, leading to critical loss of osseous integrity and glenoid fracture. Although highly active young male collision or contact athletes are most at risk, such fractures sometimes occur after relatively minor trauma at a long interval after surgery, suggesting persistent impairment of bone quality. In patients with postoperative recurrence of instability, detailed examination using computed tomography is recommended.