BACKGROUND METHODS DYNAMIC SHEAR TEST CONCLUSIONS

HYPOTHESES

We hypothesized that (1) the

dynamic shear test would have a

low clinical utility for making the

diagnosis of SLAP-only lesions,

(2) that the clinical utility of this

test would decrease in shoulders

that have SLAP lesions with

concomitant shoulder pathology,

and (3) the clinical utility of the

combination of the dynamic

shear test and other tests for the

detection of SLAP lesions would

not increase the utility of this test.

This study was of a consecutive

case series of patients who were

studied prospectively between

2007 and 2013 (N=674). The

study group included patients

with a variety of diagnoses

including AC arthritis (n=48),

rotator cuff tear (n=381),

stiffness (n=36), instability

(n=148), biceps pathology

(n=12), and SLAP lesion (n=49).

All patients had a thorough

preoperative physical

examination that included the

dynamic shear test, a relocation

test for pain, and an active

compression test.

All patients underwent

subsequent diagnostic

arthroscopy by the senior

author. Only Type II through V

SLAP lesions were considered

positive for a SLAP tear. A type I

tear was considered a

degenerative lesion and

included in the control group.

For statistical analysis, the

patients were divided into three

groups: a control group (n =

528) consisting of patients with

no SLAP lesion but with other

pathologies, an isolated SLAP

lesion group (n = 7), and a

concomitant SLAP group

(n=139) who had a SLAP tear

and some other shoulder

pathology such as a rotator cuff

tear or instability of the shoulder.

Statistical analysis was

performed by a biostatistician

using SPSS.

Table 1: Isolated SLAP lesions

Clinical Assessment of the Dynamic Shear Test for SLAP

Lesions Sonal Sodha MEng, Jacob Joseph BA, Amrut Borade MD, Edward G. McFarland, MD

Division of Shoulder Surgery, The Department of Orthopaedic Surgery

Johns Hopkins University School of Medicine, Baltimore, Maryland, USA

LIMITATIONS

IMPLICATIONS

The clinical diagnosis of

superior labrum anterior-

posterior (SLAP) lesions of the

shoulder remain a diagnostic

challenge for physicians, in part

due to the multitude of physical

examination tests which have

been found to have low clinical

utility.

The “dynamic labral shear test”

was first described in 2007 to be

diagnostic of SLAP lesions.

To date only two studies have

assessed the clinical utility of

this test for SLAP lesions with

one reporting a likelihood ratio of

1.1 and the other 31.6. These

contradictory results leave the

usefulness of this test for SLAP

lesions uncertain.

This study found that the

dynamic shear test has clinical

utility only for patients with

isolated SLAP lesions, that its

usefulness in patients with

concomitant lesions is limited

and that its combined use with

other tests does not increase its

clinical utility. These results

suggest that the dynamic shear

test has limited usefulness

when examining patients with

multiple possible diagnoses.

These findings help to elucidate

the significance of the Dynamic

shear test in clinical practice.

Directly impacts the routine

physical examination of the

shoulder during patient visits

Physicians will have a better

understanding of the dynamic

shear test and be better equipped

to make a more informed decision

about primary diagnoses prior to

operation

Isolated SLAP lesions are rare,

and most SLAP lesions occur with

concomitant pathology

Primary diagnosis for each

patient was determined by a

single physician (senior author),

who was not wholly blinded to the

pre-operative physical

examination

Our study only included patients

who had arthroscopic surgery, not

nonsurgical patients who may

have had SLAP lesions

The dynamic shear test was positive for 242 (45.8%) control patients, 6 (85.7%) patients with isolated SLAP lesions, and 79 (56.8%) of the concomitant SLAP patients.

For isolated SLAP tears the dynamic shear test had a sensitivity of 85.7, specificity of 51.9, PPV of 1.8, NPV of 99.7, LR of 6.4, and DA of 54.4. In comparison, the LR for the active compression test was 0.7

and for the relocation test was 1.5.

For patients with combined SLAP lesions with other pathologies, the dynamic shear test had a sensitivity

of 58.2, specificity of 54.2, PPV of 35.99, NPV of 82.4, LR of 1.5, and DA of 55.0.

Combining all three tests did not improve the LR for either isolated SLAP lesions or lesions with

concomitant pathology.

Table 2: Concomitant SLAP lesions

PURPOSE

The goal of this study was to

determine the clinical utility

(sensitivity, specificity, positive

predictive value (PPV), negative

predictive value (NPV), likelihood

ratio (LR), and diagnostic

accuracy (DA)) of the dynamic

shear test for making the

diagnosis of SLAP lesions.

The examiner stands behind the patient,

holding the wrist of the patient with one hand

and applying an anteriorly directed force on

the proximal humerus near the joint line with

the other hand. Patient is relaxed.

The patient’s arm is elevated from the side to

150 degrees of elevation. A positive test is

when the patient reports pain or the examiner

feels a click in the posterior shoulder between

90 and 120 degrees of elevation.

RESULTS

Table Accuracy of Exam test for the Diagnosis of Isolate SLAP Lesions

Diagnostic Values

Diagnostic test Sensitivity Specificity

Odds Ratio (95

CI) PPV NPV DA

Positive

LR

Negative

LR

% % % % %

Dynamic Shear 85.7 51.9 6.47 (.774 - 54.012) 1.83% 99.71% 54.40% 6.367 0.984

Active Compression 71.4 22.5 .725 (.139 - 3.77) 0.96% 98.68% 22.99% 0.727 1.004

Relocation test 28.6 79.2 1.526 (.293 - 7.961) 1.57% 98.96% 78.65% 1.518 0.995

Dynamic

Compression 57.1 58.5 1.877 (.417 - 8.454) 1.42% 99.24% 58.46% 1.865 0.933

Dynamic Relocation 28.6 85.9 2.434 (.465 - 12.728) 2.08% 99.13% 85.29% 2.404 0.988

Relocation AC 28.6 84.5 2.179 (.417 - 11.381) 1.90% 99.12% 83.90% 2.156 0.99

DS Rel AC 28.6 87.4 2.771 (.529 - 14.513) 2.33% 99.15% 86.78% 2.73 0.985

Table Accuracy of Exam test for the Diagnosis of Concaminant SLAP Lesions

Diagnostic Values

Diagnostic test Sensitivity Specificity Odds Ratio (95 CI) PPV NPV DA

Positive

LR

Negative

LR

% % % % %

Dynamic Shear 58.2 54.2

1.647 (1.137 -

2.386) 25.99%

82.42

% 55.04% 1.479 0.898

Active Compression 69.9 20.4 .595 (.394 - .898) 19.65%

70.86

% 31.19% 0.674 1.134

Relocation 23.9 80 1.26 (.802 - 1.980) 25.98%

78.22

% 67.32% 1.193 0.946

dynamic compression 46.6 59.7

1.289 (.892 -

1.864) 24.20%

80.15

% 56.82% 1.219 0.946

Dynamic relocation 19.3 87.1

1.619 (.997 -

2.628) 29.17%

79.72

% 72.51% 1.438 0.888

Relocatin AC 19.3 85.4

1.395 (.865 -

2.251) 26.67%

79.33

% 71.09% 1.29 0.924

DS Rel AC 17.2 88.4

1.595 (.961 -

2.648) 29.07%

79.56

% 73.11% 1.422 0.892