The Magnuson-Stack procedure for treatment of recurrent glenohumeral dislocations

The Magnuson-Stack procedure was developed in 1943 as a treatment for recurrent anterior dislocation of the glenohumeral joint. Since that time, very little literature has been published on this procedure. The purpose of our study is to evaluate its efficacy in preventing further dislocations and, also, introduce the Cybex Isokinetic Dynamometer as a quantitative tool in scientifically evaluating total shoulder function. At the Bryn Mawr (Pennsylvania) Hospital from 1971 to 1978, 43 patients underwent a Magnuson-Stack procedure. Twenty-nine returned detailed questionnaires; 26 of these patients returned for clinical and roentgenographic examination by one of the authors, and 18 had their shoulder motion and power quantitatively compared to their contralateral normal arms with the Cybex Isokinetic Dynamometer. Eighty-five percent of shoulders did not dislocate postoperatively; 90% considered their results satisfactory. By gross physical examination, no shoulder atrophy was noted. Strength seemed to equal the uninjured shoulder. Range of motion showed a 10 degrees loss of external rotation as measured with a hand-held goniometer. However, by testing range of motion with the Cybex system, a 25 degrees lack of external rotation was noted. Force values measured at 60 degrees of arc/sec and 180 degrees of arc/sec showed an 18 and 10% deficit, respectively, in external rotation. The authors believe that the Magnuson-Stack procedure has a place in the treatment of recurrent anterior dislocations of the shoulder. Also, the Cybex II isolated joint testing system provides an accurate reproducible method of comparing the postoperative results of all patients treated for dislocation of the shoulder.(ABSTRACT TRUNCATED AT 250 WORDS)