The purpose of the study was to compare the incidence of secondary intra-articular
shoulder lesions in patients with acute and chronic anterior shoulder instability.
The occurrence of glenoid shape alterations (inverted pear glenoid) in recurrent instability
was especially examined.
Data for all arthroscopically ascertained intra-articular shoulder lesions in a series
of 127 patients with acute and chronic traumatic anterior instability were recorded.
Hemarthrosis was evident in all patients with acute dislocation and in 7 patients
with chronic laxity who underwent surgery shortly after a dislocation episode. In
both groups the presence of a chondral or osteochondral Hill-Sachs lesion was noted
in 112 patients (88.1%), a Bankart lesion was noted in 106 patients (83.46%), an anterior
labroligamentous periosteal sleeve avulsion (ALPSA) lesion was noted in 13 patients
(10.23%), a SLAP lesion was noted in 26 patients (20.47%), a humeral avulsion of the
glenohumeral ligament (HAGL) lesion was noted in 2 acutely dislocated shoulders (1.57%),
and capsular laxity was noted in 33 patients (25.98%). All ALPSA lesions were noted
in patients with chronic instability (P = .044), and both HAGL lesions were found
in patients with acute dislocations (P = .002). In patients with acute dislocations
the incidence of Bankart lesions was 78.2% (18/23), whereas in chronic cases the incidence
of Bankart or ALPSA lesions was 97.11% (101/104) (P = .002). In the group with acute
dislocations there was a Hill-Sachs lesion in 15 cases (65.21%) and chronic recurrent
instability accounted for 97 cases (93.26%) (P = .001). The capsule was considered
lax in 2 patients with acute instability and 31 patients with chronic instability
(8.69% v 29.8%, P = .037). The overall frequency of SLAP lesions was not statistically
significant between acute and chronic cases (P = .868), unlike their distribution.
In acute cases there were 3 type I and 2 type II SLAP lesions, whereas in chronic
cases there were 4 type I, 13 type II, 3 type III, and 1 type IV SLAP lesions. Loose
bodies were found and removed in 17 chronic and 4 acute cases (16.34% v 13.04%, P
= .903). A partial-thickness articular rotator cuff tear was found in 14 patients:
12 with chronic dislocations and 2 with acute dislocations (11.53% v 8.69%, P = .694).
The cuff tears were partial articular surface tears, involving less than 25% of the
cuff thickness, and were treated with debridement, and cuff repair was not necessary
in any case. The inverted pear configuration of the glenoid was found in 16 cases
with chronic instability (15.38%), whereas no patient with an acutely dislocated shoulder
had an inverted pear-shaped glenoid (P = .044).
Associated, secondary intra-articular lesions are more frequent in patients with chronic
compared with acute shoulder instability, probably as a result of the repeated dislocation
or subluxation episodes.
Level IV, prognostic case series.