Acute Bony Bankarts: Tips and Tricks for Success Joseph P. Burns, MD,* and Ryan M. Vellinga, MD† Bony Bankart injuries are common after traumatic glenohumeral anterior instability events. Restoration of glenoid bony integrity is critical to minimizing the risk of recurrence, post- traumatic osteoarthritis, and in recreating normal shoulder kinematics. Surgical repair can be very technically challenging as can the preoperative decisions involved in selecting both a surgical approach (open or arthroscopic) and a method of fixation (suture anchors or screws). With a focus on arthroscopy, we present a review of the current preferred techni- ques in surgical management of bony Bankart injuries. Oper Tech Sports Med 27:25-34 © 2019 Elsevier Inc. All rights reserved. KEYWORDS shoulder instability, bony Bankart ver the past several years, the orthopaedic community Considerations that guide treatment of bony Bankart O has become increasingly aware of the high prevalence lesions include fragment size and resultant glenoid bone and critical importance of instability-associated bony lesions stock, union of fragments after fixation, timing of surgery, in the glenohumeral joint (glenoid bone loss and Hill-Sachs and absorption of fragments. Jiang et al evaluated outcomes defects).1 Osseous glenoid injury is particularly common in of arthroscopic bony Bankart repair based on glenoid bone patients who have undergone high-energy trauma and stock. In their prospective series of 50 patients, all patients patients with recurrent instability, up to 90% of whom have who had a reconstructed glenoid size greater than 80% of some degree of glenoid bony injury.2 the original diameter had successful outcomes and no recur- During a traumatic dislocation, the humeral head may rence at average 32.5 months follow-up, whereas 3 of the 4 shear off a portion of bone from the anterior inferior glenoid, failures had less than 80% reconstructed glenoid diameter. creating the so-called “bony Bankart” lesion. When a bony Even in the 7 patients who had a mal-reduced fragment, Bankart fragment is present, fixation may be achieved with only 2 of those went on to failure, and both had a recon- either open or arthroscopic surgical techniques. Small bony structed glenoid of less than 80%. The other 5 had a preoper- fragments (up to 15% of anterior-to-posterior glenoid diame- ative glenoid diameter of greater than 80%. Their results ter) can be secured arthroscopically using techniques similar suggest that a preoperative glenoid bone stock >80% or a to standard Bankart repair, in which the bony fragment is reconstructable glenoid (existing glenoid + bony fragment) of incorporated into the capsulolabral repair.3 Larger bony frag- >80% is amenable to arthroscopic bony Bankart repair with ments are more structurally important and often necessitate acceptable outcomes.7 Park et al in 2018 confirmed these advanced arthroscopic techniques for reduction and fixation, same observations in their series of 223 patients. They noted several of which have been described in the literature.4-6 that patients with bony Bankart defect >20% that had the bone fragment incorporated into the arthroscopic repair had *Southern California Orthopedic Institute Sports Fellowship, The Southern improved clinical outcomes and lower recurrence rates com- California Orthopedic Institute, Valencia, CA. pared to those patients with >20% defect and no fragment y The Southern California Orthopaedic Institute, Valencia, CA. incorporation. When the defect was less than 20%, inclusion Disclosures: JB is a paid consultant for Conmed and Mitek, SCOI receives of the bony fragment did not significantly alter recurrence, royalties from Lippincott, and RV has no financial disclosures. 8 Address reprint requests to Joseph P. Burns, MD, Southern California rates, clinical outcomes, or sports activity levels. Orthopedic Institute Sports Fellowship, The Southern California Several studies have looked at union rates after arthro- Orthopedic Institute, 24051 Newhall Ranch Rd, Valencia, CA 91354. scopic fixation of bony Bankart lesions with nonunion rates E-mail: [email protected] https://doi.org/10.1053/j.otsm.2019.01.005 25 1060-1872/© 2019 Elsevier Inc. All rights reserved. 26 J.P. Burns and R.M. Vellinga reported to range from 0%-17%.3,5,9-12 Interestingly, non- repaired with suture anchors could hypertrophy over time union did not always correlate with recurrent instability, that and restore lost glenoid area. Patients had an average of 20% is, even those patients with bony nonunion could be glenoid diameter fractured, but the remaining bony frag- expected to have excellent stability and clinical outcomes ments available for repair averaged less than 5% of native gle- through development of a fibrous union.10-12 However, for noid diameter, suggesting absorption had occurred. large bony defects, bony union is apparently much more Interestingly, at 5-8 years follow-up, the repaired glenoids important. When evaluating patients with large glenoid were remeasured and found to have reconstituted their gle- defects (>20% of glenoid area), Nakagawa et al showed a noid area back to just over 100% of their preinjury glenoid 66.7% recurrent instability rate in patients with nonunited size.15 fragments, as opposed to a 0% recurrence rate in those While the majority of studies support treating bony Bank- patients who achieved complete bony union. They also art lesions with surgery, Macquiera et al showed that large showed that complete union takes on average more than 7 fractures (>5 mm on plain radiographs) which were concen- months, with smaller fragments taking longer than large frag- trically reduced, even if the fracture was displaced, did well ments to completely unite.12 with nonoperative treatment, avoiding instability, apprehen- Timing of fixation also affects union rates. Plath et al sion, and osteoarthritis.16 Spiegl et al recommended nonsur- showed only a 5% nonunion rate in acute cases but 40% in gical treatment for acute small (<5% glenoid) fractures that chronic bony Bankart lesions, defining acute lesions as those were concentrically reduced, and recommended surgery for cases that had a hemarthrosis, bleeding at the fracture site, larger lesions as well as those small lesions with subluxation and fresh spongy edges of the fragment at the time of sur- on radiographs.17 gery. However, union rates did not correlate to subjective Based upon the available literature and our personal expe- outcomes in their study.11 rience, our preference is to treat very large lesions (>25%) The importance of the timing of surgery is also borne out that are concentrically reduced and minimally displaced by Pocellini et al who showed the instability recurrence rate (<3 mm) conservatively, considering these to be more simi- after bony Bankart repair was significantly lower in surgeries lar to the category of “glenoid fractures” than to the category performed less than 3 months from injury, compared to of “glenohumeral instability.” Very small (<5%) chips off the those more than 3 months after injury.9 Shah et al recently glenoid can be considered for nonsurgical treatment, but reviewed results in perhaps the most at-risk patient popula- even these injuries are so often associated with recurrent tion: collision athletes. They reviewed 22 rugby players with instability, especially in the younger population, that they bony Bankart lesions less than 25% of the glenoid, all of frequently require surgical repair.18 As a result, we consider which were repaired arthroscopically within 4 months of the surgery for small and medium (up to 25% glenoid diameter) injury. All patients returned to their preinjury sporting level, lesions, as well as for larger lesions that are associated with and 91% remained stable and asymptomatic at 2 years with humeral subluxation or significant displacement (>3 mm). the 2 failures occurring after additional traumatic sporting Magnetic resonance imaging is obtained for all patients pre- accidents.13 senting with instability, and a CT scan with 3-D reconstruc- While considering the importance of glenoid bone stock tions is obtained for any patient with bony involvement of before and after bony Bankart repair, it is also imperative to the glenoid. Our preferred surgical techniques will be recognize that absorption of fractured bone can occur over described below, and it should be noted that our preference time. Nakagawa et al showed bone absorption occurred on for surgical approach is nearly always arthroscopic. Open all 163 patients of their series of bony Bankart lesions treated reduction internal fixation was the original preferred surgical without surgery. Bone absorption involved both the remaining technique, but as arthroscopic techniques have advanced, glenoid and the bone fragment, with the greatest amount of surgeon ability to comprehensively address the spectrum of absorption occurring within the first year after initial injury most bony Bankart injuries arthroscopically has improved (51.9% of fragment), but also showed progressive absorption dramatically. The reasons for our arthroscopic preference are over time (70% at 2 years).14 Jiang et al also showed that as follows: bony attrition occurs of both the glenoid and the bony The Benefits of Arthroscopic Fixation of Acute Bony Bankart fragment.7 Injuries Thus, when evaluating for surgery, surgeons should recog- nize that some degree of permanent bone loss will likely be 1. Glenohumeral joint access: Bony Bankart injuries are present. Even after successful repair of a bony Bankart lesion, often associated with additional bony fragmentation, the reconstructed glenoid bone can still be less than 80% of loose bodies, extensive labral damage, Hill-Sachs its native preinjury area, which may increase the risk of lesions, rotator cuff damage, and biceps anchor/supe- recurrent instability. In chronic and sub-acute cases, where rior labrum anterior to posterior damage. An arthro- total bone stock may fall below 80% of the native area, sur- scopic approach facilitates management of all these geons should consider obtaining a 3-dimensional CT scan conditions, many of which cannot be addressed prior to surgery. through an arthrotomy.