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Dynamic examination techniques in shoulder instability
Dynamic examination techniques in shoulder instability N. Wuelker, MD, D. Kohn, MD, and C. Knop, MD, Hannover, Germany
We prospectively examined 2S patients with recurrent shoulder dislocation before surgical stabilization. On the basis of preoperative and intraoperative findings, a preliminary working diagnosis was established; anterior dislocation in 74 patients, posterior dislocation in 4, and unclassified dislocation in 7. Glenohumeral ioin! laxity was subsequently assessed by clinical examination, fluoroscopy, and ultrasonography in all patients and in a control group of 2S subjects without shoulder disease. Normal laxity was defined as humeral head displacement not exceeding the standard deviation of the mean in the control group. Ultrasonographic findings were poorly reproducible and concurred with the results of clinical examination in only 4 patients and with fluoroscopic results in 7 patients. Clinical examination and fluoroscopic findings were reproducible and were identical in 79 patients. Laxity was present in 23 shoulders at clinical examination and in 78 shoulders at fluoroscopic examination. The preliminary working diagnosis was confirmed in 70 patients by clinical examination and in 6 patients by fluoroscopy. Previously unknown laxity was revealed by clinical examination in 73 and by fluoroscopy in 77 shoulders. Glenohumeral ioint laxity should be evaluated before the operation by clinical and fluoroscopic examinations and must be taken into account in the operative techniques used to achieve stability. (J SHOULDER ELBOW SURG 7994;3:207-74)
Precise identification of the direction and extent of laxity at the glenohumeral joint is essential for appropriate treatment of shoulder instability. Stabilization procedures are likely to fail, if all components of laxity are not taken into account. Neer 14 considered undiagnosed, multidirectional instability the most frequent cause of failure in operations performed to achieve shoulder stabilization. Dislocation of the shoulder frequently results in secondary lesions at the glenohumeral joint that can be diagnosed with various imaging procedures. The Hill-Sachs lesion/ a bony impression at the posterolateral aspect of the humeral head, is caused by the glenoid. Comparable lesions at the anterior aspect of the
From the Orthopaedic Department, Hannover Medical School, Hannover. Reprint requests: Nikolaus Wuelker, MD, Orthopaedic Department, Hannover Medical School, 30601 Hannover, Germany. Copyright © 1994 by Journal of Shoulder and Elbow Surgery Board of Trustrees. 1058-2746/94/$3.00 + 0 32/1158459
humeral head may occur in posterior dislocation. 9 • 20 The Bankart lesion" (detachment of the anterior labrum from the glenoid) may be diagnosed with arthroscopy, contrast computed tomographic scan, or magnetic resonance imaging. Special radiographic techniques" 19. 20 are useful to evaluate the glenoid rim. The reported incidence of secondary lesions in traumatic, recurrent shoulder dislocations is from 19% to 100%.6.9· 21 Dynamic examination techniques are used to evaluate the pattern of joint laxity. This evaluation is done by placing stress on the glenohumeral joint and measuring the amount of displacement of the humeral head relative to the glenoid. Various techniques for testing laxity dynamically have been described." a. 11. 13. 15-17 We prospectively evaluated 25 patients who had recurrent shoulder dislocation. Three dynamic examination techniques were investigated: clinical drawer and sulcus testing/' 15 fluoroscopic irnoqinq,': 5.11.13.16.17 and ultrasonographic imoqinq." 12 The results were compared with the patients' preoperative and intraoperative findings.
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Table I Pertinent data about 25 patients with recurrent shoulder dislocation Patient No. 1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
Age (yr)
Sex
Side
A
B
49 19 18 22 24 22 16 69 53 19 22 19 25 23 19 40 26 19 30 43 25 29 21 19 27
M M M M M M F M M F F M M M M F M M M F M M M M M
L L L R R R L R R R R L R R R R R L R L L R R L L
1 2 3 4 5 6 1 7 8 9 11 1 11 1 10 11 12 19 13 10 14 15 16 17 18
1 2,3 2,3 1 2,3 1 4 2,3,5 1 4 2,3 1 5 4 2,3 1 1 2,5 2,3 2 2 2,3 4 2 2
C
D
E
F
G
?
All A A A A A AlP/I A A P/I A All 0 AlP/I A 0 A A A AlP/I All All P/I A A
All A A 0 A A AlP/I 0 A P/I 0 All 0 AlP/I A 0 A A 0 AlP/I All All A A 0
All 0 P AlP P 0 P 0 A P 0 P AlP P P 0 0 0 0 AlP/I 0 0 0 0 P
All A A A A A AlP/I A A P/I A All A AlP/I A
A A ?
A ?
P A ?
P A ?
A P A ? ?
A A A A A P A A
?
A A A AlP/I All All AlP/I A A
A, Initial dislocation: 1, no trauma; 2, direct injury to shoulder (soccer); 3, arm pulled (judo); 4, fall on outstretched arm (field hockey); 5, fall on elbow (volleyball); 6, fallon elevated arm (judo); 7, fallon extended arm during walking; 8, forced extension during assault; 9, fall on adducted elbow (handball); 10, normal swim stroke; 11, hand caught during fall; 12, during handstand, no external impact; 13, direct fall on shoulder (handball); 14, abduction and internal rotation (motorcycle accident); 15, extension of abducted arm (judo); 16, fall forward onto shoulder (athletics); 17, fall on flexed arm (soccer); 18, external rotation during fall from stairs; 19, grand mal seizure. B, Clues to direction of instability: 1, none; 2, Hill-Sachs lesion; 3, Bankart lesion; 4, voluntary dislocation; 5, dislocation on x-ray. C, Preliminary working diagnosis without inclusion of dynamic examination techniques. D, Laxityat clinical examination. E, Laxityat fluoroscopy. F, Laxityat ultrasonography. G, Final working diagnosis with inclusion of dynamic examination techniques. A, Anterior; P, posterior; I, inferior; 0, no laxity.
MATERIAL AND METHODS Twenty-five patients (20 men and 5 women; mean age 27.9 years; range 16 to 69 years) with recurrent dislocation of the shoulder were prospectively examined at the orthopaedic department of Hannover Medical School (Table I). In 13 patients the shoulder joint repeatedly dislocated at rest. In some patients this dislocation occurred during sleep. Four patients were able to dislocate and relocate their shoulders spontaneously. The average time interval between the initial dislocation and the examination was 4 years (range, 0.5 to 19 years). Nine of the 25 patients were competitive athletes. In 18 patients the initial dislocation occurred during significant shoulder trauma. For 12 of the 18 patients this dislocation was related to
sports activities, mostly judo, handball, and soccer. In three cases a direct impact occurred on the shoulder. In 15 cases forced motion of the shoulder occurred. The remaining seven patients reported no significant trauma at the initial dislocation or thereafter. All patients underwent routine radiographic examination in the anteroposterior plane, axillary plane, and tangential scapular view at their initial presentation. Ultrasonography in standard projections" for evaluation of the rotator cuff and computed arthrotomography were performed in all patients. All shoulders were stabilized with an open technique. In 18 of the 25 patients the direction of the dislocation could be inferred from preoperative or intraoperative findings (Table I). A Hill-Sachs
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Table II Average d isplacement of humeral head relative to glenoid w ith ultrasonographic and fluoroscopic imaging in control group (n = 25)
Fluoroscopy Ultrasonography
Anterior (mm)
Posterior (mm)
Inferior (mm)
1.9 3.9
4.1 7.2
2.0 ± 2.3 4.1 :t 3.4
:!: :!:
1.7 3.0
:!: :!:
3.6 5.7
lesion" was evident on radiographs in 13 patients/ and a Bankart lesion was found during the operation in 8 patients. Radiographic documentation of the dislocated shoulder was available in three patients. Four patients were able to dislocate their shoulders spontaneously. On the basis of these findings a preliminary working diagnosis was established for each patient (Table I): anterior dislocation in 14 patients/ posterior dislocation in 4/ and unclassified dislocation in 7. Normal displacement values for the head of the humerus were determined with fluoroscopic and ultrasonographic imaging of the right and left shoulder joints of 25 volunteers (18 men and seven women; mean age 27.9 years; range 19 to 33 years) (Table II). All were heatlhy subjects with no history of shoulder disease. Twelve were active in various sports. Normal shoulder laxity was defined as displacement not exceeding the mean displacement plus the SO of the control group. All 25 patients with recurrent shoulder dislocation and the control group were examined with dynamic techniques as described below. On the basis of the results a final working diagnosis was established and was compared with the preliminary working diagnosis. Clinical examination. The anterior-posterior drawer test was performed with the subject siHing and the arm hanging freely by the side (Figure 1). The examiner stabilized the patient's scapula between the coracoid process and the spine of the scapula with one hand. The other hand grasped the humeral head and centered it on the glenoid by pushing it medially. The humeral head was then displaced anteriorly and posteriorly until a clinical endpoint was reached. Evaluation of inferior laxity was performed in an identical position by placing axial traction on the arm. A soft-tissue impression lateral to the acromion, the "sulcus sign," was ob-
Figure 1 Clinical exam ination technique. Examiner stands behind patient, and uses one hand to stabil ize scapula and other hand to shift humeral head in an terior / posterior direction . served. All shoulders were graded "stable" or "unstable" in the anterior, posterior, and inferior directions. The patients were examined at their initial presentation and at the day before operation by one of us (N. W.), who, at the time of the initial examination, was not informed about the patient's medical history or other findings. Fluoroscopic imaging. Fluoroscopic imaging was performed with the Siremobil 2 N fluoroscope (Siemens, Munich, Germany) (Figure 2). With the patient in the supine position, the shoulder was secured to the examination table with a strap on top and a sandbag underneath . The shoulder was placed in 90° of abduction and 20° of flexion. The fluoroscope was positioned in the axillary projection. A soft, broad belt was placed around the patient's up-
210 Wuelker, Kohn, and Knop
Figure 2 Fluoroscopic examination technique. X-ray beam is directed parallel to surface of glenoid [i.e., in axillary orientation). Patients lies supine on examination table. Arm is fixed to a frame in 90° of abduction and 20° of flexion. Scapula is stabilized between shoulder sling and sandbag. Force is applied with pulley system in anterior and posterior directions.
per arm as close to the glenohumeral joint as possible. A posterior/anterior force equal to one quarter of the patient's body weight (l0 to 20 kg) was loaded onto the belt, with the weight hanging freely downward or directed upward over a pulley. Anterior and posterior excursions of the humeral head against the glenoid cavity were documented (Figure 3). Inferior laxity was examined with the patient in the sitting position. The fluoroscopy beam was angled 20° laterally, perpendicular to the plane of the scapula. Both arms were loaded with weights equal to one quarter of the patient's body weight. A metal template was placed in the path of the x-ray beam to eliminate errors of magnifi-
J. Shoulder Elbow Surg. July/August 1994
cation. Displacement of the nearest fitting circle around the humeral head relative to the center of the glenoid was measured. Patients in the study were examined at their initial presentation and on the day before the operation. All radiographs were analyzed by an independent physician. Ultrasonographic imaging. A 5.0 MHz CS 5000 transducer (Hitachi, Tokyo) was used for ultrasonographic exorninotion." 22 Anteriorposterior laxity was evaluated with the patient in the prone position (Figure'4) . One examiner held the arm of the subject in 90° of abduction and 20° of flexion and positioned the ultrasonography transducer. The second examiner manually displaced the humeral head on the glenoid with a technique identical to that of clinical drawer testing. Laxity was measured as displacement of the posterior contour of the humeral head against the infraspinatus fossa of the scapula (Figure 5). Inferior laxity was evaluated with the patient sitting and the ultrasonography transducer in the lateral position. Axial traction was placed on the hanging arm, and the displacement between the humeral head ,contour and the superior surface of the acromion was determined. Patients in the study were examined with ultrasonography by one of us (N . W.) ot their initial presentation and on the day before the operation.
RESULTS Clinical examination on the day before the operation revealed glenohumeral joint laxity in 23 patients: isolated anterior laxity in 14, anterior and inferior laxity in 4, posterior and inferior laxity in 2, and laxity in all three directions in 3. No patient had isolated posterior laxity. In 2 patients (patients 13 and 16) no laxity was apparent on clinical examination. Both had a history of trauma. Clinical examination confirmed the preliminary working diagnosis in 10 patients. In 7 patients additional laxity became apparent clinically. In 6 of the 7 patients with an unclassified preliminary working diagnosis, laxity was apparent on clinical examination. Examination by the same physician at the initial presentation several weeks previously had revealed identical results in all but 3 patients. Eight patients reported pain during the examination, but they had the same incidence of joint laxity as the other patients.
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Figure 3 Fluoroscopic imaging. A, Axillary projection with anterior force . B, Axillary projection with posterior force. C, Anteroposterior projection in neutral position .
D, Anteroposterior projection with inferior force .
Fluoroscopy indicted laxity in 1B patients: isolated anterior laxity in 10, anterior and inferior laxity in 4, posterior and inferior laxity in 1, and laxity in all three directions in 3. No laxity was revealed by fluoroscopy in 7 patients. All had significant trauma during the initial dislocation. The preliminary working diagnosis was confirmed in 6 patients, all with isolated anterior laxity. In 6 other patients additional laxity appeared on fluoroscopy. In 5 of the 7 patients with on unclassified preliminary working diagnosis, laxity become apparent with fluoroscopy. Results were identical on repeated examination in all patients. Five patients reported pain during fluoroscopy, but their results did not differ from those of patients without pain. The overage fluoroscopy time was 22 seconds. The radiation skin entrance dosage amounted to
twice the dosage of a standard anteroposterior shoulder radiograph . Ultrasonography indicated laxity in 13 pa tients: isolated anterior laxity in 1, isolated pos terior laxity in 8, and combined laxity in 4. In 12 patients no laxity was revealed by ultrasonography. The preliminary working diagnosis was confirmed by ultrasonography in 3 patients. UItrasonographic results obtained at the first presentation were identical to those obtained on the day before operation for only 12 of the 25 patients. Fluoroscopic and clinical examination results were identical for 19 of the 25 patients. In 5 patients laxity was not observed with fluoro scopic examination, but it was observed with clinical examination. In 1 patient (patient 23) posterior-inferior laxity was observed with clin-
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Figure 4 Ultrasonographic exam ination in posterior transducer pos ition . One examiner holds pat ient's arm in 90° of obduction and 20° of flexion and pos itions transducer. Second exam iner stabilizes scapula wi th ane hand and shifts humeral head in anterior or posterior direction with other hand. ical examination, and anterior laxity was observed with fluoroscopic examination. When ultrasonographic results were compared with those of clinical examination, results were identical in only 4 patients. In 7 patients the results of ultrasonography and fluoroscopy were identical. In particular, ultrasonographic posterior laxity, which was found in 8 patients, was not confirmed with clinical or fluoroscopic exam ination . On the basis of the preliminary working diagnosis and the results of the dynamic examination techniques, a final working diagnosis was established. This diagnosis was identical to the preliminary working diagnosis in 11 patients. All were classified as having anterior instability. An unclassified working diagnosis was changed to a classified final diagnosis in 6 patients : 4 with isolated anterior laxity and 2 w ith comb ined lax ity. A preliminary working diagnosis of isolated laxity was changed to combined laxity in 7 patients: 3, anterior laxity and 4, pasterior laxity. In 1 patient (patient 16) with recurrent shoulder dislocation and an unclassified working diagnosis, no lax ity was found on dynamic examination. She was treated successfully with anterior capsular tightening . No patient had additional intraarticular lesions on radiograph ic and ultrasonographic examination and at intraoperative inspectio n of the joint.
DISCUSSION Decisions about the indication and the operative technique in cases of recurrent shoulder dislocation or subluxation require precise identification of the character and direction of the instability. Unless all components of the instability are considered, the success of surgical treatment is doubtful. If the head of the humerus is forced into the opposite direction by an unwarranted tightening procedure, permanent subluxation and early [oint degeneration may resuIt. 1• • 70 Shoulder dislocatian frequently causes structurallesions in the glenohumeral jaint that allaw the direction of the dislocation to be identified. Secondary lesions occur, if significant force is exerted on the joint (i.e., in traumatic shoulder
dislocction]." 9 . 21 Verification with dynamic examination techniques is difficult because of the absence of a reference standard. In addition, precise standardization of applied forces is difficult. This difficulty was evident in several previous investigatians.·· II . 17. 18 In the present study the accuracy of dynamic techn iques was evaluated by comparing their results with each other and with other preoperative and intraoperative findings. Fluoroscopy is the most strictly standardized technique. No false-positive results were indicated by other investiqoto rs." Fluoroscopic measurements in this study were highly repro-
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Figure 5 Ultrasonographic imaging (poster ior transducer pos ition): distance between posterior margin of glenoid (G) and humeral head (H) is measured. A, Posterior stress ima ge. B, Anterior stress imoge. 5, Posterior ma rg in of scapula . ducible. Fluoroscopy revealed laxity not included in the preliminary work ing diagnosis in 11 of the 25 patients. Therefore we recommend that all patients undergo fluoroscopy before the operation and that laxity be included in the final working diagnosis and in the operative treatment plan. Seven of the 25 patients with recurrent shoulder dislocation had no evidence of laxity on fluoroscopy, indicating the low sensitivity of this technique. Intraobserver reproducibility of clinical ex· amination findings was slightly inferi o r to those of fluoroscopy. An examination technique similar to the one used in our study was used by Harryman et ol.' Gerber and Gonz" performed clinical drawer testing with the patient in the supine position and the shoulder abducted. An experienced examiner is requ ired, because force application cannot be standardized and laxity cannot be measured numerically. Clinical examination indicated isolated anterior laxity in five patients who had no laxity on fluoroscopy. From the present study it appears that clinical examination is more sensitive than fluoroscopy. Therefore, we consider clinical laxity testing an integral part of the preoperative workup of recurrent shoulder dislocation. We include laxity that is present on clinical examination in our final working diagnosis. Ultrasonography was the least reproducible technique. In the volunteer group displacement measured by ultrasonography was almost twice that of fluoroscopy. The accuracy of ultrasonography depends on the examination plane
(i.e., the position of the ultrasonography transducer). With drawer testing a shift of the soft tissues underneath the transducer invariably occurs. This shift may have contributed to the large number of cases of posterior laxity that were found on ultrasonography but were not confirmed by other techniques. The examiner in our study had several years of experience and training with ultrasonography. The results of this technique obtained at less specialized centers must be questioned. Ultrasonographic imaging in shoulder instability took approximately twice as long as other techniques, and on additional experienced examiner was required to position the ultrasonography transducer. The definition of normal laxity of the glenohumeral joint is somewhat arbitrary. The results from our control group demonstrate considerable voriotion.": 13 . 17 In our study the SD was chosen as the limit of normal glenohumeral joint laxity. Accordingly anterior translation up to 3.6 mm, posterior translation up to 7.7 mm, and inferior translation up to 4.3 mm were considered normal with fluoroscopy. Papilion and Sholl" regarded anterior 1 posterior translation up to 14 % 137% of the anteroposterior glenoid diameter normal. This is slightly more (3.5 mm/9.25 mm) than in our study, based on an average anteroposterior glenoid diameter of 29 mrn." The difference may be a result of the fact that Papilion and Shall performed examinations with their patients under general anesthesia. Norris" reported posterior translation up to 50% of the glenoid diameter in normal shoul-
214
Wuelker, Kahn, and Knap
ders but no anterior translation. Harryman et ol .' used an electromagnetic spatial tracking device to test displacement during drawer testing in the adducted arm position in probands. Displacement was 7.8:t 4.0 mm anteriorly, 7.9 :t 5.6 mm posteriorly, and 10.6 :t 3.8 mm inferiorly. Painful muscle tension during the examination did not influence the results. Therefore we do not routinely use examinat ion w ith patients under general anesthesia ." 1•• 16 Our patients were a highly selected, referred group. They do not reflect the average distribution of instability patterns in a community setting. A number of patients were competitive athletes who played overhead sports. They had a high incidence of multidirectional instability caused by repetitive trauma. In 16 of the 25 patients in our study, the preliminary working diagnosis was substantially altered when the results of the dynamic examination techniques were included. If laxity is present in more than one direction or in a direction other than the direction of dislocation, it must be reflected in the technique of operative stabilization. Glenohumeral joint laxity beyond the limits of "normal" still may not cause symptomatic insta b ility. However, glenohumeral joint mechanics will be unfavorably altered, if only one direction of lax ity is stabilized and the others are not treated.
REFERENCES 1. Adler H, Lohmann B. The stability of the shoulder joint in stress radiography. Arch Orthop Trauma Surg 1984; 103:83-4. 2. Bankart ASB. Recurrent o r hab itual dislocation of the shoulder [oint. BMJ 1923;2: 1132-41. 3. Bernageau J, Patte D, Debe yre J, Ferrone J. Interet du prof il glenoidien dons les dislocat ions recidivan tes de I'epaule. Rev Ch ir Orthop Reporatrice Appa r Mot 1976;62(suppl): 142-4. 4. Cof ield RH, Irving JF. Evaluation and classifica tion of shoulder instability: with special reference to examination under anesthesia . On Orthop 1987;223:32-43 .
J. Shoulder Elbow Surg. July/August 1994
5. Fronek J, Warren RF, Bowen M . Posterior subdisloca tion of the glenohumeral joint. J Bone Joint Surg [Ami 1989;71A:205-16. 6. Gerber C, Ganz R. Diagnostik und kausale Therapie der SchulterinstabilitCit. Unfallchirurg 1986;89 :418-28. 7. Harryman DT II, Sidles JA, Har ris SL, Matsen FA. Loxity of the normal glenohumeral joint: 0 quantitative in vivo assessment. J SHOULDER ELBOW SURG 1992;2 :66-76. 8. Hedtmann A, Fett H. Al tos und Lehrbuch der Schultersonographie. Stuttgart: Enke Verlag , 1988: 120-4. 9. Hill HA, Sochs MD. The grooved defec t of the humera l head . Radiology 1940;35:690·700. 10.' Iannotti JP, Gabriel JP, Schneck SL, Evans BG, Misra S. The normal glenohumeral rero'tTonships. J Bone Joint Surg [Am] 1992;74A:491-500. 11. Jalovaara P,Myllylo V, PCiivCinsalo M . Autotraction stress roentgenography for demonstration anterior and inferior insta bility of the shoulder joint. Clin Orthop 1992; 284: 136-43 . 12. Jerosch J, Marquardt M, W inkelmann W . Der Stellenwert der Sonograph ie in der Beurteilung von lnstob ilitcten des glenohumeralen Ge lenkes. Z Orthop lhre Grenzgeb 1990; 128:41-5 . 13. Maki NJ . Cinerad iographic studies with shoulder insta bilities. Am J Sports Med 1988; 16:362-4 . 14. Neer CS. Shoulder reconstruction . Philadelphia : WB Sounders, 1990:273-340. 15. Neer CS, Foster D Inferior capsular shift for Involuntary inferior and multidirect ional instab ility of the shoulder J Bone Joint Surg [Am ] 1980;62A :897 -908. 16. No rris TR. C-arm fluoroscopic evaluation under anesthesia for glenohumeral subdisloca tions. Orthop Trans 1983;7;22-5 . 17. Papilion JA, Sholl LM. Fluoroscop ic evaluat ion for subtle shoulder instability. Am J Sports M ed 1992;20:548-52. 18. Pavlov H, Warren RF, Weiss CB, Dines DM. The roentgenographic evalua tion of anter ior shoulder instability. C1in Orthop 1985; 194:153-8. 19. Resch H, Benedetto KP, Kadletz R, Dan iaux H. Rontgenuntersuchung bei habitueller Schulterdislocation-die Wert igkeit verschiedener Aufnahmetechniken. Unfallchirurgie 1985;11:65-9. 20. Rowe CR. Dislocation of the shoulder . In: Rowe CR, editor. The shoulder. New York: Churchill Livingstone, 1988: 165-291 . 2 1. Weber BG. Die gewohnheilsmof3ige Schulterverrenkung . Unfallheilkunde 1979;82 :413-7. 22. Wuelker N , Kohn D. Sonogrophische Routined iognos tik der Schulter: ein vereinfochter Untersuchungsgong. UItraschall Med 1991 ;12:228-35.
We prospectively examined 2S patients with recurrent shoulder dislocation before surgical stabilization. On the basis of preoperative and intraoperative findings, a preliminary working diagnosis was established; anterior dislocation in 74 patients, posterior dislocation in 4, and unclassified dislocation in 7. Glenohumeral ioin! laxity was subsequently assessed by clinical examination, fluoroscopy, and ultrasonography in all patients and in a control group of 2S subjects without shoulder disease. Normal laxity was defined as humeral head displacement not exceeding the standard deviation of the mean in the control group. Ultrasonographic findings were poorly reproducible and concurred with the results of clinical examination in only 4 patients and with fluoroscopic results in 7 patients. Clinical examination and fluoroscopic findings were reproducible and were identical in 79 patients. Laxity was present in 23 shoulders at clinical examination and in 78 shoulders at fluoroscopic examination. The preliminary working diagnosis was confirmed in 70 patients by clinical examination and in 6 patients by fluoroscopy. Previously unknown laxity was revealed by clinical examination in 73 and by fluoroscopy in 77 shoulders. Glenohumeral ioint laxity should be evaluated before the operation by clinical and fluoroscopic examinations and must be taken into account in the operative techniques used to achieve stability. (J SHOULDER ELBOW SURG 7994;3:207-74)
Precise identification of the direction and extent of laxity at the glenohumeral joint is essential for appropriate treatment of shoulder instability. Stabilization procedures are likely to fail, if all components of laxity are not taken into account. Neer 14 considered undiagnosed, multidirectional instability the most frequent cause of failure in operations performed to achieve shoulder stabilization. Dislocation of the shoulder frequently results in secondary lesions at the glenohumeral joint that can be diagnosed with various imaging procedures. The Hill-Sachs lesion/ a bony impression at the posterolateral aspect of the humeral head, is caused by the glenoid. Comparable lesions at the anterior aspect of the
From the Orthopaedic Department, Hannover Medical School, Hannover. Reprint requests: Nikolaus Wuelker, MD, Orthopaedic Department, Hannover Medical School, 30601 Hannover, Germany. Copyright © 1994 by Journal of Shoulder and Elbow Surgery Board of Trustrees. 1058-2746/94/$3.00 + 0 32/1158459
humeral head may occur in posterior dislocation. 9 • 20 The Bankart lesion" (detachment of the anterior labrum from the glenoid) may be diagnosed with arthroscopy, contrast computed tomographic scan, or magnetic resonance imaging. Special radiographic techniques" 19. 20 are useful to evaluate the glenoid rim. The reported incidence of secondary lesions in traumatic, recurrent shoulder dislocations is from 19% to 100%.6.9· 21 Dynamic examination techniques are used to evaluate the pattern of joint laxity. This evaluation is done by placing stress on the glenohumeral joint and measuring the amount of displacement of the humeral head relative to the glenoid. Various techniques for testing laxity dynamically have been described." a. 11. 13. 15-17 We prospectively evaluated 25 patients who had recurrent shoulder dislocation. Three dynamic examination techniques were investigated: clinical drawer and sulcus testing/' 15 fluoroscopic irnoqinq,': 5.11.13.16.17 and ultrasonographic imoqinq." 12 The results were compared with the patients' preoperative and intraoperative findings.
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Table I Pertinent data about 25 patients with recurrent shoulder dislocation Patient No. 1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
Age (yr)
Sex
Side
A
B
49 19 18 22 24 22 16 69 53 19 22 19 25 23 19 40 26 19 30 43 25 29 21 19 27
M M M M M M F M M F F M M M M F M M M F M M M M M
L L L R R R L R R R R L R R R R R L R L L R R L L
1 2 3 4 5 6 1 7 8 9 11 1 11 1 10 11 12 19 13 10 14 15 16 17 18
1 2,3 2,3 1 2,3 1 4 2,3,5 1 4 2,3 1 5 4 2,3 1 1 2,5 2,3 2 2 2,3 4 2 2
C
D
E
F
G
?
All A A A A A AlP/I A A P/I A All 0 AlP/I A 0 A A A AlP/I All All P/I A A
All A A 0 A A AlP/I 0 A P/I 0 All 0 AlP/I A 0 A A 0 AlP/I All All A A 0
All 0 P AlP P 0 P 0 A P 0 P AlP P P 0 0 0 0 AlP/I 0 0 0 0 P
All A A A A A AlP/I A A P/I A All A AlP/I A
A A ?
A ?
P A ?
P A ?
A P A ? ?
A A A A A P A A
?
A A A AlP/I All All AlP/I A A
A, Initial dislocation: 1, no trauma; 2, direct injury to shoulder (soccer); 3, arm pulled (judo); 4, fall on outstretched arm (field hockey); 5, fall on elbow (volleyball); 6, fallon elevated arm (judo); 7, fallon extended arm during walking; 8, forced extension during assault; 9, fall on adducted elbow (handball); 10, normal swim stroke; 11, hand caught during fall; 12, during handstand, no external impact; 13, direct fall on shoulder (handball); 14, abduction and internal rotation (motorcycle accident); 15, extension of abducted arm (judo); 16, fall forward onto shoulder (athletics); 17, fall on flexed arm (soccer); 18, external rotation during fall from stairs; 19, grand mal seizure. B, Clues to direction of instability: 1, none; 2, Hill-Sachs lesion; 3, Bankart lesion; 4, voluntary dislocation; 5, dislocation on x-ray. C, Preliminary working diagnosis without inclusion of dynamic examination techniques. D, Laxityat clinical examination. E, Laxityat fluoroscopy. F, Laxityat ultrasonography. G, Final working diagnosis with inclusion of dynamic examination techniques. A, Anterior; P, posterior; I, inferior; 0, no laxity.
MATERIAL AND METHODS Twenty-five patients (20 men and 5 women; mean age 27.9 years; range 16 to 69 years) with recurrent dislocation of the shoulder were prospectively examined at the orthopaedic department of Hannover Medical School (Table I). In 13 patients the shoulder joint repeatedly dislocated at rest. In some patients this dislocation occurred during sleep. Four patients were able to dislocate and relocate their shoulders spontaneously. The average time interval between the initial dislocation and the examination was 4 years (range, 0.5 to 19 years). Nine of the 25 patients were competitive athletes. In 18 patients the initial dislocation occurred during significant shoulder trauma. For 12 of the 18 patients this dislocation was related to
sports activities, mostly judo, handball, and soccer. In three cases a direct impact occurred on the shoulder. In 15 cases forced motion of the shoulder occurred. The remaining seven patients reported no significant trauma at the initial dislocation or thereafter. All patients underwent routine radiographic examination in the anteroposterior plane, axillary plane, and tangential scapular view at their initial presentation. Ultrasonography in standard projections" for evaluation of the rotator cuff and computed arthrotomography were performed in all patients. All shoulders were stabilized with an open technique. In 18 of the 25 patients the direction of the dislocation could be inferred from preoperative or intraoperative findings (Table I). A Hill-Sachs
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Table II Average d isplacement of humeral head relative to glenoid w ith ultrasonographic and fluoroscopic imaging in control group (n = 25)
Fluoroscopy Ultrasonography
Anterior (mm)
Posterior (mm)
Inferior (mm)
1.9 3.9
4.1 7.2
2.0 ± 2.3 4.1 :t 3.4
:!: :!:
1.7 3.0
:!: :!:
3.6 5.7
lesion" was evident on radiographs in 13 patients/ and a Bankart lesion was found during the operation in 8 patients. Radiographic documentation of the dislocated shoulder was available in three patients. Four patients were able to dislocate their shoulders spontaneously. On the basis of these findings a preliminary working diagnosis was established for each patient (Table I): anterior dislocation in 14 patients/ posterior dislocation in 4/ and unclassified dislocation in 7. Normal displacement values for the head of the humerus were determined with fluoroscopic and ultrasonographic imaging of the right and left shoulder joints of 25 volunteers (18 men and seven women; mean age 27.9 years; range 19 to 33 years) (Table II). All were heatlhy subjects with no history of shoulder disease. Twelve were active in various sports. Normal shoulder laxity was defined as displacement not exceeding the mean displacement plus the SO of the control group. All 25 patients with recurrent shoulder dislocation and the control group were examined with dynamic techniques as described below. On the basis of the results a final working diagnosis was established and was compared with the preliminary working diagnosis. Clinical examination. The anterior-posterior drawer test was performed with the subject siHing and the arm hanging freely by the side (Figure 1). The examiner stabilized the patient's scapula between the coracoid process and the spine of the scapula with one hand. The other hand grasped the humeral head and centered it on the glenoid by pushing it medially. The humeral head was then displaced anteriorly and posteriorly until a clinical endpoint was reached. Evaluation of inferior laxity was performed in an identical position by placing axial traction on the arm. A soft-tissue impression lateral to the acromion, the "sulcus sign," was ob-
Figure 1 Clinical exam ination technique. Examiner stands behind patient, and uses one hand to stabil ize scapula and other hand to shift humeral head in an terior / posterior direction . served. All shoulders were graded "stable" or "unstable" in the anterior, posterior, and inferior directions. The patients were examined at their initial presentation and at the day before operation by one of us (N. W.), who, at the time of the initial examination, was not informed about the patient's medical history or other findings. Fluoroscopic imaging. Fluoroscopic imaging was performed with the Siremobil 2 N fluoroscope (Siemens, Munich, Germany) (Figure 2). With the patient in the supine position, the shoulder was secured to the examination table with a strap on top and a sandbag underneath . The shoulder was placed in 90° of abduction and 20° of flexion. The fluoroscope was positioned in the axillary projection. A soft, broad belt was placed around the patient's up-
210 Wuelker, Kohn, and Knop
Figure 2 Fluoroscopic examination technique. X-ray beam is directed parallel to surface of glenoid [i.e., in axillary orientation). Patients lies supine on examination table. Arm is fixed to a frame in 90° of abduction and 20° of flexion. Scapula is stabilized between shoulder sling and sandbag. Force is applied with pulley system in anterior and posterior directions.
per arm as close to the glenohumeral joint as possible. A posterior/anterior force equal to one quarter of the patient's body weight (l0 to 20 kg) was loaded onto the belt, with the weight hanging freely downward or directed upward over a pulley. Anterior and posterior excursions of the humeral head against the glenoid cavity were documented (Figure 3). Inferior laxity was examined with the patient in the sitting position. The fluoroscopy beam was angled 20° laterally, perpendicular to the plane of the scapula. Both arms were loaded with weights equal to one quarter of the patient's body weight. A metal template was placed in the path of the x-ray beam to eliminate errors of magnifi-
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cation. Displacement of the nearest fitting circle around the humeral head relative to the center of the glenoid was measured. Patients in the study were examined at their initial presentation and on the day before the operation. All radiographs were analyzed by an independent physician. Ultrasonographic imaging. A 5.0 MHz CS 5000 transducer (Hitachi, Tokyo) was used for ultrasonographic exorninotion." 22 Anteriorposterior laxity was evaluated with the patient in the prone position (Figure'4) . One examiner held the arm of the subject in 90° of abduction and 20° of flexion and positioned the ultrasonography transducer. The second examiner manually displaced the humeral head on the glenoid with a technique identical to that of clinical drawer testing. Laxity was measured as displacement of the posterior contour of the humeral head against the infraspinatus fossa of the scapula (Figure 5). Inferior laxity was evaluated with the patient sitting and the ultrasonography transducer in the lateral position. Axial traction was placed on the hanging arm, and the displacement between the humeral head ,contour and the superior surface of the acromion was determined. Patients in the study were examined with ultrasonography by one of us (N . W.) ot their initial presentation and on the day before the operation.
RESULTS Clinical examination on the day before the operation revealed glenohumeral joint laxity in 23 patients: isolated anterior laxity in 14, anterior and inferior laxity in 4, posterior and inferior laxity in 2, and laxity in all three directions in 3. No patient had isolated posterior laxity. In 2 patients (patients 13 and 16) no laxity was apparent on clinical examination. Both had a history of trauma. Clinical examination confirmed the preliminary working diagnosis in 10 patients. In 7 patients additional laxity became apparent clinically. In 6 of the 7 patients with an unclassified preliminary working diagnosis, laxity was apparent on clinical examination. Examination by the same physician at the initial presentation several weeks previously had revealed identical results in all but 3 patients. Eight patients reported pain during the examination, but they had the same incidence of joint laxity as the other patients.
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Figure 3 Fluoroscopic imaging. A, Axillary projection with anterior force . B, Axillary projection with posterior force. C, Anteroposterior projection in neutral position .
D, Anteroposterior projection with inferior force .
Fluoroscopy indicted laxity in 1B patients: isolated anterior laxity in 10, anterior and inferior laxity in 4, posterior and inferior laxity in 1, and laxity in all three directions in 3. No laxity was revealed by fluoroscopy in 7 patients. All had significant trauma during the initial dislocation. The preliminary working diagnosis was confirmed in 6 patients, all with isolated anterior laxity. In 6 other patients additional laxity appeared on fluoroscopy. In 5 of the 7 patients with on unclassified preliminary working diagnosis, laxity become apparent with fluoroscopy. Results were identical on repeated examination in all patients. Five patients reported pain during fluoroscopy, but their results did not differ from those of patients without pain. The overage fluoroscopy time was 22 seconds. The radiation skin entrance dosage amounted to
twice the dosage of a standard anteroposterior shoulder radiograph . Ultrasonography indicated laxity in 13 pa tients: isolated anterior laxity in 1, isolated pos terior laxity in 8, and combined laxity in 4. In 12 patients no laxity was revealed by ultrasonography. The preliminary working diagnosis was confirmed by ultrasonography in 3 patients. UItrasonographic results obtained at the first presentation were identical to those obtained on the day before operation for only 12 of the 25 patients. Fluoroscopic and clinical examination results were identical for 19 of the 25 patients. In 5 patients laxity was not observed with fluoro scopic examination, but it was observed with clinical examination. In 1 patient (patient 23) posterior-inferior laxity was observed with clin-
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Figure 4 Ultrasonographic exam ination in posterior transducer pos ition . One examiner holds pat ient's arm in 90° of obduction and 20° of flexion and pos itions transducer. Second exam iner stabilizes scapula wi th ane hand and shifts humeral head in anterior or posterior direction with other hand. ical examination, and anterior laxity was observed with fluoroscopic examination. When ultrasonographic results were compared with those of clinical examination, results were identical in only 4 patients. In 7 patients the results of ultrasonography and fluoroscopy were identical. In particular, ultrasonographic posterior laxity, which was found in 8 patients, was not confirmed with clinical or fluoroscopic exam ination . On the basis of the preliminary working diagnosis and the results of the dynamic examination techniques, a final working diagnosis was established. This diagnosis was identical to the preliminary working diagnosis in 11 patients. All were classified as having anterior instability. An unclassified working diagnosis was changed to a classified final diagnosis in 6 patients : 4 with isolated anterior laxity and 2 w ith comb ined lax ity. A preliminary working diagnosis of isolated laxity was changed to combined laxity in 7 patients: 3, anterior laxity and 4, pasterior laxity. In 1 patient (patient 16) with recurrent shoulder dislocation and an unclassified working diagnosis, no lax ity was found on dynamic examination. She was treated successfully with anterior capsular tightening . No patient had additional intraarticular lesions on radiograph ic and ultrasonographic examination and at intraoperative inspectio n of the joint.
DISCUSSION Decisions about the indication and the operative technique in cases of recurrent shoulder dislocation or subluxation require precise identification of the character and direction of the instability. Unless all components of the instability are considered, the success of surgical treatment is doubtful. If the head of the humerus is forced into the opposite direction by an unwarranted tightening procedure, permanent subluxation and early [oint degeneration may resuIt. 1• • 70 Shoulder dislocatian frequently causes structurallesions in the glenohumeral jaint that allaw the direction of the dislocation to be identified. Secondary lesions occur, if significant force is exerted on the joint (i.e., in traumatic shoulder
dislocction]." 9 . 21 Verification with dynamic examination techniques is difficult because of the absence of a reference standard. In addition, precise standardization of applied forces is difficult. This difficulty was evident in several previous investigatians.·· II . 17. 18 In the present study the accuracy of dynamic techn iques was evaluated by comparing their results with each other and with other preoperative and intraoperative findings. Fluoroscopy is the most strictly standardized technique. No false-positive results were indicated by other investiqoto rs." Fluoroscopic measurements in this study were highly repro-
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Figure 5 Ultrasonographic imaging (poster ior transducer pos ition): distance between posterior margin of glenoid (G) and humeral head (H) is measured. A, Posterior stress ima ge. B, Anterior stress imoge. 5, Posterior ma rg in of scapula . ducible. Fluoroscopy revealed laxity not included in the preliminary work ing diagnosis in 11 of the 25 patients. Therefore we recommend that all patients undergo fluoroscopy before the operation and that laxity be included in the final working diagnosis and in the operative treatment plan. Seven of the 25 patients with recurrent shoulder dislocation had no evidence of laxity on fluoroscopy, indicating the low sensitivity of this technique. Intraobserver reproducibility of clinical ex· amination findings was slightly inferi o r to those of fluoroscopy. An examination technique similar to the one used in our study was used by Harryman et ol.' Gerber and Gonz" performed clinical drawer testing with the patient in the supine position and the shoulder abducted. An experienced examiner is requ ired, because force application cannot be standardized and laxity cannot be measured numerically. Clinical examination indicated isolated anterior laxity in five patients who had no laxity on fluoroscopy. From the present study it appears that clinical examination is more sensitive than fluoroscopy. Therefore, we consider clinical laxity testing an integral part of the preoperative workup of recurrent shoulder dislocation. We include laxity that is present on clinical examination in our final working diagnosis. Ultrasonography was the least reproducible technique. In the volunteer group displacement measured by ultrasonography was almost twice that of fluoroscopy. The accuracy of ultrasonography depends on the examination plane
(i.e., the position of the ultrasonography transducer). With drawer testing a shift of the soft tissues underneath the transducer invariably occurs. This shift may have contributed to the large number of cases of posterior laxity that were found on ultrasonography but were not confirmed by other techniques. The examiner in our study had several years of experience and training with ultrasonography. The results of this technique obtained at less specialized centers must be questioned. Ultrasonographic imaging in shoulder instability took approximately twice as long as other techniques, and on additional experienced examiner was required to position the ultrasonography transducer. The definition of normal laxity of the glenohumeral joint is somewhat arbitrary. The results from our control group demonstrate considerable voriotion.": 13 . 17 In our study the SD was chosen as the limit of normal glenohumeral joint laxity. Accordingly anterior translation up to 3.6 mm, posterior translation up to 7.7 mm, and inferior translation up to 4.3 mm were considered normal with fluoroscopy. Papilion and Sholl" regarded anterior 1 posterior translation up to 14 % 137% of the anteroposterior glenoid diameter normal. This is slightly more (3.5 mm/9.25 mm) than in our study, based on an average anteroposterior glenoid diameter of 29 mrn." The difference may be a result of the fact that Papilion and Shall performed examinations with their patients under general anesthesia. Norris" reported posterior translation up to 50% of the glenoid diameter in normal shoul-
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ders but no anterior translation. Harryman et ol .' used an electromagnetic spatial tracking device to test displacement during drawer testing in the adducted arm position in probands. Displacement was 7.8:t 4.0 mm anteriorly, 7.9 :t 5.6 mm posteriorly, and 10.6 :t 3.8 mm inferiorly. Painful muscle tension during the examination did not influence the results. Therefore we do not routinely use examinat ion w ith patients under general anesthesia ." 1•• 16 Our patients were a highly selected, referred group. They do not reflect the average distribution of instability patterns in a community setting. A number of patients were competitive athletes who played overhead sports. They had a high incidence of multidirectional instability caused by repetitive trauma. In 16 of the 25 patients in our study, the preliminary working diagnosis was substantially altered when the results of the dynamic examination techniques were included. If laxity is present in more than one direction or in a direction other than the direction of dislocation, it must be reflected in the technique of operative stabilization. Glenohumeral joint laxity beyond the limits of "normal" still may not cause symptomatic insta b ility. However, glenohumeral joint mechanics will be unfavorably altered, if only one direction of lax ity is stabilized and the others are not treated.
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5. Fronek J, Warren RF, Bowen M . Posterior subdisloca tion of the glenohumeral joint. J Bone Joint Surg [Ami 1989;71A:205-16. 6. Gerber C, Ganz R. Diagnostik und kausale Therapie der SchulterinstabilitCit. Unfallchirurg 1986;89 :418-28. 7. Harryman DT II, Sidles JA, Har ris SL, Matsen FA. Loxity of the normal glenohumeral joint: 0 quantitative in vivo assessment. J SHOULDER ELBOW SURG 1992;2 :66-76. 8. Hedtmann A, Fett H. Al tos und Lehrbuch der Schultersonographie. Stuttgart: Enke Verlag , 1988: 120-4. 9. Hill HA, Sochs MD. The grooved defec t of the humera l head . Radiology 1940;35:690·700. 10.' Iannotti JP, Gabriel JP, Schneck SL, Evans BG, Misra S. The normal glenohumeral rero'tTonships. J Bone Joint Surg [Am] 1992;74A:491-500. 11. Jalovaara P,Myllylo V, PCiivCinsalo M . Autotraction stress roentgenography for demonstration anterior and inferior insta bility of the shoulder joint. Clin Orthop 1992; 284: 136-43 . 12. Jerosch J, Marquardt M, W inkelmann W . Der Stellenwert der Sonograph ie in der Beurteilung von lnstob ilitcten des glenohumeralen Ge lenkes. Z Orthop lhre Grenzgeb 1990; 128:41-5 . 13. Maki NJ . Cinerad iographic studies with shoulder insta bilities. Am J Sports Med 1988; 16:362-4 . 14. Neer CS. Shoulder reconstruction . Philadelphia : WB Sounders, 1990:273-340. 15. Neer CS, Foster D Inferior capsular shift for Involuntary inferior and multidirect ional instab ility of the shoulder J Bone Joint Surg [Am ] 1980;62A :897 -908. 16. No rris TR. C-arm fluoroscopic evaluation under anesthesia for glenohumeral subdisloca tions. Orthop Trans 1983;7;22-5 . 17. Papilion JA, Sholl LM. Fluoroscop ic evaluat ion for subtle shoulder instability. Am J Sports M ed 1992;20:548-52. 18. Pavlov H, Warren RF, Weiss CB, Dines DM. The roentgenographic evalua tion of anter ior shoulder instability. C1in Orthop 1985; 194:153-8. 19. Resch H, Benedetto KP, Kadletz R, Dan iaux H. Rontgenuntersuchung bei habitueller Schulterdislocation-die Wert igkeit verschiedener Aufnahmetechniken. Unfallchirurgie 1985;11:65-9. 20. Rowe CR. Dislocation of the shoulder . In: Rowe CR, editor. The shoulder. New York: Churchill Livingstone, 1988: 165-291 . 2 1. Weber BG. Die gewohnheilsmof3ige Schulterverrenkung . Unfallheilkunde 1979;82 :413-7. 22. Wuelker N , Kohn D. Sonogrophische Routined iognos tik der Schulter: ein vereinfochter Untersuchungsgong. UItraschall Med 1991 ;12:228-35.