A NEW CLINICAL TEST OF ANTERIOR SHOULDER INSTABILITY

Abstract

Purpose: The hand-to-forehead test is a new subjective and objective test for anterior shoulder instability. This test is performed preoperatively under general anaesthesia and involves a quantifiable patient-controlled apprehension test and an objective quantitative test of anterior stability.

Material and methods: Between January 1998 and April 2000, 135 patients (97 men and 38 women), mean age 25 years, age range 16–40 years, candidates for surgery for anterior instability of the shoulder (115 Latarget, 14 Bankart, 6 capsular shift) were tested. A control group of 300 candidates free of any shoulder disorder for other surgery were also tested.

Results: the Apprehension test was positive in 95 of the operated patients and negative in 40. Mean angle was 160° (90–180°). The test was always negative in patients with an underlying hyperlaxity (18 patients). The test was positive in 20 controls and negative in 270. Test sensitivity was 72%, specificity 92.5%, positive predictive value 42%, (prevalence 1.5%) and negative predictive value 86%. Reproducibility was 80%. The objective test was positive in 125 of the operated patients and negative in 10. The value was 2++ in 55% of the cases. In the control group, the objective test was positive in 28 and negative in 272. The sensitivity of the objective test was 95%, specificity 90%, positive predictive value 55% and negative predictive value 95%. Reproducibility was 92%.

Discussion: The purpose of the hand-to-forehead test is to express the instability as perceived by the patient and to exteriorise anterior laxity without reproducing true anterior displacement. Excepting cases with underlying hyperlaxity, this test does not appear to be inflenced by different injuries subsequent to recurrent anterior dislocation. (no significant difference between glenoid bone lesions, Broca lesions or Malgaigne notches).

Conclusion: This new test provides a reliable objective assessment of anterior instability of the shoulder using a quantifiable combination of classical apprehension and laxity tests. It is a supplementary diagnostic tool for difficult cases and a useful aid for pre- and postoperative evaluation of these patients.