Posterior and combined labral tears are more common than previously thought, especially in young active populations. The study reviewed 442 patients undergoing shoulder stabilization surgery and found that posterior and combined tears accounted for 47% of cases, compared to only 53% being isolated anterior tears. Rates of posterior and combined tears were even higher in sporting populations (52%) compared to non-sporting populations (32%). Rugby players in particular had a high rate of posterior and combined tears (53%). The study concludes that posterior and combined shoulder instability is more prevalent than reported, especially in contact sports.

1. The Incidence of Traumatic Posterior and Combined Labral Tears in Patients
Undergoing Arthroscopic Shoulder Stabilisation
MA Imam, S Javed, P Monga, L Funk, M Walton
Wrightington Hospital, UK
ISAKOS, Cancun 2019
Correspondence: Mr Mohamed Imam MD PHD FRCS (Tr and Orth); Email: Mohamed.imam@aol.com
Introduction: Shoulder instability is a common cause of shoulder pain and dysfunction in younger adults, particularly in athletes. Isolated anterior
shoulder instability is traditionally believed to account for over 90% of shoulder instability. Posterior and combined shoulder instabilities are believed to
be rarer, accounting for only 2% to 5% of cases. However, more recent studies have highlighted an increased incidence of posterior and combined
shoulder instabilities in young, active populations, which was reflected in our practice. While there has been an improved awareness and
understanding of this injury in the last decade, it remains a diagnostic and therapeutic challenge.
Aims: The purpose of this study was to describe the demographics, incidence and nature of capsulolabral pathology in a large cohort of patients with
surgically treated traumatic shoulder instability, both in sporting and non-sporting populations. Furthermore, we aimed to determine how often posterior
and combined labral tears were treated compared with isolated anterior injuries.
Methods:
• All patients undergoing surgery for traumatic shoulder instability over
a three-year period between 2012 and 2014 were identified from our
database. A retrospective review of consecutive patients under the
care of three senior shoulder surgeons was performed.
• Inclusion criteria were all patients who underwent first time operative
treatment for traumatic shoulder instability. Exclusion criteria included
patients without a diagnosis of atraumatic shoulder instability or those
patients undergoing revision stabilisation surgery.
• At the time of intervention, all patients underwent an examination
under anaesthesia, arthroscopic assessment of the glenoid
capsulolabral structures and subsequent repairs where indicated.
Patients were categorised according to the location of their labral
pathology (anterior, posterior, or combined anterior and posterior) and
whether their injury was sustained during sporting or non-sporting
activity.
• The sporting population were defined as patients who described
themselves as competitive sportspeople, semi-professional or
professional athletes, who sustained their injury as a result of sport.
They were subdivided according to the participating activity which
included rugby, football, canoeing, cricket and motocross.
Table 3: Summary of the results
Results:
• There were 442 primary arthroscopic labral repair procedures performed
over the three-year period. The total cohort had a mean age of 25.91±9.09
years (range, 14-67 years) and consisted of 89.6% males. There was no
significant difference in mean age or gender between the isolated anterior,
posterior or combined groups (p=0.383 and p=0.541, respectively).
• Of the 442 patients who underwent a shoulder labral repair, isolated anterior
labral pathology occurred in 52.9% (n=234), with posterior and combined
labral tears accounting for 16.3% (n=72) and 30.8%, respectively (n=136)
(Table 3).
• Patients were stratified as either sporting or non-sporting; 74.9% of patients
were categorised as sporting (n=331) and had a mean age of 24.91±5.69
years, which was significantly lower than the mean age of 35.40±11.94
years in the non-sporting population (p<0.001). In the non-sporting
population 68.5% (n=76) of patients had isolated anterior labral tears with
12.6% (n=14) posterior and 18.9% (n=21) combined. In the sporting
population isolated anterior labral tears accounted for 47.7% (n=158),
posterior 17.5% (n=58) and combined labral tears 34.7% (n=115).
The sporting population had a significantly greater proportion of posterior
and combined labral tears with the non-sporting population a significantly
greater proportion of anterior labral tears (p=0.013).
• Rugby players had the greatest incidence of shoulder instability within the
sporting cohort accounting for 231 cases. Of the 231 cases, 47.2% were
isolated anterior labral tears, 12.6% isolated posterior and 40.3% combined
lesions.
Conclusions:
Posterior and combined shoulder labral tears are more prevalent than previously
reported in the civilian population. The rates are higher in young, sporting
populations and especially in contact sports such as rugby.
References:
• Owens BD, Duffey ML, Nelson BJ, DeBerardino TM, Taylor DC, Mountcastle SB. The incidence and characteristics of shoulder instability at the United States Military Academy. Am J Sports Med 2007;35:1168-1173
• Owens BD, Agel J, Mountcastle SB, Cameron KL, Nelson BJ. Incidence of glenohumeral instability in collegiate athletics. Am J Sports Med 2009;37:1750-4
• Song DJ, Cook JB, Krul KP, Bottoni CR, Rowles DJ, Shaha SH, Tokish JM. High frequency of posterior and combined shoulder instability in young active patients. J Shoulder Elbow Surg 2015;24(2):186-190
• Bottoni CR, Franks BR, Moore JH, DeBerardino TM, Taylor DC, Arciero RA. Operative stabilization of posterior shoulder instability. Am J Sports Med 2005;33:996-1002
• Kaplan LD, Flanigan DC, Norwig J, Jost P, Bradley J. Prevalence and variance of shoulder injuries in elite collegiate football players. Am J Sports Med 2005;33(8):1142-6.
• Robinson CM, Aderinto J. Recurrent posterior shoulder instability. J Bone Joint Surg Am 2005;87:883-92
• Provencher MT, LeClere LE, King S, McDonald LS, Frank RM, Mologne TS, et al. Posterior instability of the shoulder: diagnosis and management. Am J Sports Med 2011;39:874-886
• Passanante GJ, Skalski MR, Patel DB, White EA, Schein AJ, Gottsegen CJ, Matcuk GR Jr. Inferior glenohumeral ligament (IGHL) complex: anatomy, injuries, imaging features, and treatment options. Emerg Radiol 2017;24(1):65-71
• Ovesen J, Nielsen S. Stability of the shoulder joint: cadaver study of stabilizing structures. Acta Orthop Scand 1985;56(2):149-151.
• O’Connell PW, Nuber GW, Mileski RA, Lautenschlager E. The contribution of the glenohumeral ligaments to anterior stability of the shoulder joint. Am J Sports Med 1990;18(6):579-584
• Dewing CB, McCormick F, Bell SJ, et al. An analysis of capsular area in patients with anterior, posterior, and multidirectional shoulder instability. Am J Sports Med 2008;36(3):515-522
• Badge R, Tambe A, Funk L. Arthroscopic isolated posterior labral repair in rugby players. Int J Shoulder Surg 2009;3(1):4-7
• Blomquist J, Solheim E, Liavaag S, Schroder CP, Espehaug B, Havelin LI. Shoulder instability surgery in Norway: the first report from a multicenter register, with 1-year follow-up. Acta Orthop 2012;83:165-170
• Funk L, Snow M. SLAP tears of the glenoid labrum in contact athletes. Clin J Sport Med 2007;17:1–4.
Table 2: Location of labral pathology as found intraoperatively
Table 1: Published series (>100) cases of incidence and characteristics of shoulder
instability