Isolated and Combined Tears of the Subscapularis Tendon - CiteSeerX

Isolated and Combined Tears of the Subscapularis Tendon Peter C. Kreuz,* MD, Andreas Remiger, MD, Christoph Erggelet, MD, PhD, Stefan Hinterwimmer, MD, Philipp Niemeyer, MD, and Andre Gächter, MD, PhD From the Department of Orthopaedic Surgery, Kantonsspital St. Gallen, St. Gallen, Switzerland

Background: Isolated and combined subscapularis tendon tears are rare and are described in the literature only in small numbers. Hypothesis: The outcome of surgical intervention for isolated and combined subscapularis tendon tears may be influenced by the tear pattern of the anterior rotator cuff and the period of time between trauma and surgical procedure. Study Design: Case series; Level of evidence, 4. Methods: Between 1994 and 1999, 34 shoulders with isolated traumatic tears (16 shoulders) or subscapularis tendon rupture combined with a supraspinatus tendon tear were treated operatively. The average patient age was 51 years, and the mean follow-up period was 37 months. For statistical analyses, the Friedman and Mann-Whitney tests were used. Results: In patients with isolated tears, the Constant score rose from an average of 43.9 to 88.7 points (P < .01), and in patients with combined tears, it rose from an average of 40.6 to 74.7 points (P < .01). Isolated tears improved 14 points more than combined tears (P < .05). The delay between trauma and surgical intervention was inversely proportional to the improvement in the Constant score. The Spearman coefficient of correlation was –0.97 in isolated tears and –0.89 in combined tears. Conclusions: Young patients with isolated traumatic tears of the subscapularis tendon and immediate repair have the best prognostic factors for treatment. Accuracy in the trauma history and the clinical and radiographic examination is demanded. Keywords: subscapularis tendon; supraspinatus tendon; tendon tear; Constant score; lift-off test

Tears of the subscapularis tendon, the most anterior part of the rotator cuff, are reported to be uncommon, and they rarely occur in isolation.10,22,23 According to the literature, the subscapularis tendon is still involved in approximately 5% of all rotator cuff tears.4,7,8,12,20,24 The diagnosis is often difficult because other injuries of the rotator cuff, the subacromial region, and the periacromial tissue overshadow and complicate the diagnosis of a subscapularis tendon rupture.25,26 Because of the small number of cases, comparative studies of different-sized tears of the anterior rotator cuff are still missing. The objective of this study was to find prognostic factors of different tear patterns comparing isolated and combined subscapularis tendon tears with respect to the function and the outcome after surgical treatment.

MATERIALS AND METHODS Between 1994 and 1999, 323 rotator cuff tears were managed operatively at our center. Thirty-four of these shoulders had a traumatic rupture of the subscapularis tendon. Of these 34 patients, 16 had an isolated rupture of the subscapularis tendon in the absence of other lesions. In the other 18 patients, the subscapularis tendon tear was combined with a supraspinatus tendon rupture. In all cases, the infraspinatus tendon was not involved. The mean age of all 34 patients was 51 years (range, 27-66 years). The dominant shoulder was involved in 28 cases; 24 patients were male (Tables 1 and 2). In 21 patients, diagnoses such as subacromial impingement or glenohumeral instability from other hospitals led to primary medical and physical therapy and therefore to a delay of the operative treatment. After physical examination, radiographic evaluation, dynamic sonography (Figure 1),11 MRI (Figure 2),22,29 and arthroscopy, the repair of the subscapularis tendon was performed operatively through a deltopectoral groove approach. After identification of the deltopectoral interval and retraction of the cephalic vein laterally, the axillary nerve was located at the inferior aspect of the capsule and protected with gentle retraction. The subscapularis tendon

*Address correspondence to Peter C. Kreuz, MD, Department of Orthopaedic Surgery, Albert Ludwig University of Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany (e-mail: [email protected]). No potential conflict of interest declared. The American Journal of Sports Medicine, Vol. 33, No. 12 DOI: 10.1177/0363546505277118 © 2005 American Orthopaedic Society for Sports Medicine

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TABLE 1 Preoperative Patient Information on 34 Shoulders With Isolated and Combined Traumatic Tears of the Subscapularis Tendon Mean age, y (range) Sex, male:female Dominant arm involved Size of the tendon tear Complete subscapularis tendon tear Partial subscapularis tendon tear Additional tear of the supraspinatus tendon Mechanism of injury Traumatic hyperextension or external rotation of the abducted arm Direct blow to the shoulder Motor vehicle accident Mean delay between trauma and surgical intervention, mo (range) Isolated subscapularis tendon tears Combined subscapularis tendon tears Subjective pain Moderate Severe Night pain Positive lift-off test result Increased passive external rotation, deg (range) Mode of detection, n Dynamic ultrasound MRI Arthroscopy Mean Constant score before surgery

51 (27-66) 24:10 28 13 21 18

19 13 2

2.5 (0.25-6) 5.0 (1-8)

Figure 1. Dynamic sonography of a right shoulder, coracoacromial view; the subscapularis tendon is completely torn (arrow). BT, biceps tendon; IG, intertubercular groove; C, coracoid process.

26 8 11 29 15 (5-30) 27 33 34 42

was released from adhesions that restricted tendon excursion, including release in the interval underneath the conjoined tendon as well as release of the coracohumeral ligament and capsulolabral attachments to the tendon.10 In 17 patients, the subscapularis tendon was refixed with MitekGII anchors (De Puy Mitek, Johnson & Johnson Co, Norwood, Mass) (Figures 3 A and B), in 13 patients a transosseous suture was performed, and 4 patients were treated with a direct tendon to tendon suture.22 All ruptures were repairable. In 8 combined tears, an additional superior approach was required with involvement of the supraspinatus tendon, which was mobilized and repaired through holes in the greater tuberosity.3,6,18 An acromioplasty was performed in all combined subscapularis tendon tears.34 Passive mobilization, including pendulum exercises out of the sling with limited external rotation and abduction, started immediately after surgery. In case of an additional supraspinatus tendon tear, the arm was positioned in about 80° of internal rotation on an abduction pillow. After 4 weeks, active-assisted forward elevation and limited active-assisted external rotation were allowed under the guidance of a physical therapist. The degree of external rotation was increased gradually over 6 weeks until the level of external rotation established at surgery was obtained. After 6 to 8 weeks, there were no more motion limits, and after 3 months, strengthening exercises were permitted.22

Figure 2. Axial T1-weighted MRI (repetition time, 970 milliseconds; echo time, 27 milliseconds) of the right shoulder demonstrating a complete lesion of the subscapularis tendon (arrow). The tendon is retracted behind the coracoid process.

All patients were examined again after 3, 6, 12, and 36 months. The mean follow-up was at 37 months (range, 2848 months).The Constant score2,9 as well as the patient’s working ability and subjective contentment were used for evaluation. For analyses, baseline clinical data were compared with follow-up data using the Friedman test, and differentsized defects were compared using the unpaired MannWhitney test. Statistical significance was set at P < .05.

RESULTS In all patients, the subscapularis tendon tear was caused by an injury. In 19 cases, the mechanism of trauma was

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TABLE 2 Constant Scores in Isolated and Combined Subscapularis Tendon Tearsa

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 26 27 28 29 30 31 32 33 34

Sex Male Male Male Male Male Male Female Male Male Female Male Male Male Male Male Male Female Male Male Female Male Male Male Female Male Male Male Female Female Male Female Female Male Female

Interval Size of From SubMean Injury in Injury to scapularis Age, Dominant Sports Mechanism Surgery, Tendon Additional Preoperative Postoperative Follow-up, y Limb? Participationb of Injuryc mo Tear Teard CS CS mo 39 38 51 48 33 36 53 56 52 33 27 60 39 49 52 64 61 49 64 61 49 61 66 58 41 47 51 56 47 61 49 65 62 46

Yes Yes Yes Yes Yes Yes Yes No Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes No No Yes Yes Yes Yes No No Yes No Yes Yes Yes No Yes

1e,f 2e 3e 4 5e 1e 4 3 6 3e 7e 4 3e 8 6e 9 6 10 9f 8 11e 8 9 11e,f 12e 13 10 14 15f 16 17 16 14e 18e

1 1 1 1 1 1 1 3 1 1 2 2 1 1 2 2 1 1 1 2 2 2 2 1 2 3 2 1 2 1 1 1 2 2

0.25 0.5 2 0.75 0.25 1 1 1.5 0.75 6 6 3 4 5 3 5 3 1 2 3 6 8 8 7 2 4 5 6 4 6 4 7 8 6

complete complete complete complete complete complete complete complete complete partial partial partial partial partial partial partial complete complete complete complete partial partial partial partial partial partial partial partial partial partial partial partial partial partial

– – – – – – – – – – – – – – – – + + + + + + + + + + + + + + + + + +

42 40 38 35 41 43 36 35 38 65 55 42 56 49 46 42 31 32 34 40 41 43 44 44 42 39 45 40 42 46 41 44 38 45

98 93 85 86 96 92 85 82 87 96 91 83 94 86 86 79 74 82 70 72 76 68 64 74 86 82 80 74 76 72 80 70 68 76

36 30 28 48 42 28 31 35 39 37 42 32 35 34 44 41 32 38 40 36 39 35 34 42 40 36 37 33 39 42 36 38 33 35

a There was no significant difference in the preoperative Constant score (CS; P > .05), but there was significant improvement in both groups (P < .01). Isolated subscapularis tendon tears (average CS, 88.7) improved more (P < .05) in comparison with combined subscapularis tendon tears (average CS, 74.7). Patients younger than 40 years had the best results (average CS, 94.3). The dominant arm was involved in 28 of all 34 subscapularis tendon tears. b 1 = handball; 2 = basketball; 3 = skiing; 4 = fitness; 5 = javelin; 6 = jogging; 7 = snowboarding; 8 = swimming; 9 = golf; 10 = soccer; 11 = tennis; 12 = windsurfing; 13 = paragliding; 14 = cycling; 15 = badminton; 16 = walking; 17 = dancing; 18 = skating. c 1 = traumatic hyperextension or external rotation of the abducted arm; 2 = direct blow to the shoulder; 3 = motor vehicle accident. d – indicates isolated subscapularis tendon tear; + indicates subscapularis tendon rupture combined with supraspinatus tendon tear. e Injury occurred during the sports activity. f Patient did not return to sports activity after surgical intervention.

hyperextension or external rotation of the abducted arm31: 1 patient injured his shoulder chopping wood, 5 skiers had a traumatic external rotation when the ski pole was blocked in the snow, 8 athletes twisted their shoulders during javelin or other fitness sports, and 5 patients tried to hold on to railings while falling down stairs. Thirteen patients sustained direct blows to the shoulder, and 2 patients were involved in a motor vehicle accident (Table 2).

Physical examination before surgical intervention revealed tenderness in the region of the intertubercular groove and the tubercles. Because of pain and weakness in the affected shoulder, internal rotation was limited in all tears. External rotation was normal (mean, 45°; range, 35°-55°) but was in most cases painful. In combined ruptures, abduction and elevation were additionally limited to an average of 100° (range, 40°-150°).

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A


B

Figure 3. Radiograph with axial (A) and frontal (B) views of the right shoulder after surgical refixation of a torn subscapularis tendon with 3 bone anchors.

The Gerber lift-off test16 result was positive in 29 cases. In the other 5 patients, the test could not be performed because of pain. In cases of a total tendon tear, the lift-off test and the Napoleon sign1 results were always positive.5 In the 21 cases with partial tendon tear, the lift-off test result was positive in 13, and the Napoleon test result was positive in 3 cases. The Jobe test21 result was positive— especially in external rotation of the abducted arm—in 14 patients with combined anterior rotator cuff tears. In the other 4 patients with combined tears, abduction was not possible. After clinical examination, the diagnosis was confirmed for each patient by radiographs, dynamic ultrasound, and MRI. A total of 13 supraspinatus lesions (of 18) and 27 tears of the subscapularis tendon (of 34) were seen (Table 1) with dynamic sonography30; 15 of the isolated tears and all 18 combined subscapularis tendon tears were identified with MRI (Table 1). Retraction of the subscapularis tendon was present in most cases—especially with a longer delay between trauma and surgical intervention. All lesions could be detected with arthroscopy.4 However, only the deltopectoral groove approach could reveal the extent of the subscapularis tendon rupture.22 The patients underwent clinical re-examination 6 months after surgery. In all patients, the lift-off test result was negative. Internal and external rotation were comparable between isolated and combined tears (Figures 4 A and B). However, abduction and subjective contentment were better in patients with isolated subscapularis tendon tears than in patients with combined ruptures (Figures 4C

and 5). Of the 34 patients, 30 patients subjectively rated the result as excellent or good (Figure 5). Preoperative patient evaluation revealed no significant difference in the Constant score between patients with isolated and combined tears (P > .05). The Constant score rose in patients with isolated tears from an average of 43.9 points to 88.7 points (P < .01) and in patients with combined tears from an average of 40.6 points to 74.7 points (P < .01) (Table 2). The difference in postoperative Constant score between the groups was significant (P < .05). The preoperative patient evaluation revealed a better shoulder function in patients with partial tears (mean 45.2 points; range, 38-65 points) compared to patients with total subscapularis tendon tears (mean 37.3 points; range, 31-43 points) (P = .002). There was significant improvement in both groups (P < .001); however, patients with total tears improved 14.3 points more than did patients with partial tears (P = .001) (Table 2). Patients younger than 40 years of age reached an average Constant score of 94.3 points, and older patients reached a score value of 77.9 points (P < .05). The Spearman coefficient of correlation between the age of the patients and the postoperative Constant score was –0.85 in isolated tears, –0.89 in combined tears, and –0.82 overall (Table 2, Figure 6). The correlation was significant at the .01 level. All patients returned to their previous employment, and 30 returned to their previous sports activities. The return to sports without primary involvement of the shoulder, such as soccer, jogging, skating, or cycling, was possible—

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A Figure 5. Subjective result.

B

Figure 6. Correlation between the age of the patients and the postoperative Constant score; the Spearman coefficient of correlation was –0.85 in isolated tears, –0.89 in combined tears, and –0.82 overall (P = .01).

C Figure 4. Shoulder mobility after subscapularis tendon repair: (A) internal rotation, (B) external rotation, and (C) abduction.

even in patients with limited motion of the affected shoulder—within the first 4 months. Handball, basketball, javelin, badminton, or tennis—sports with active involvement of the operated shoulder—were performed only after a fitness program under the guidance of a physical therapist. Four patients did not return to their previous sports because of temporary pain and limited motion in the operated shoulder (Table 2): 2 patients were older than 50 years (1 golfer and 1 tennis player) and 2 patients were younger (1 badminton player and 1 handball player). The golfer and handball player had total tears, and the other 2 patients had partial tears of the subscapularis tendon. Only the handball player had an isolated rupture and performed competitive sports. In the other 3 patients, the supraspinatus tendon was additionally involved. On average, surgery was performed on the ruptures 3.8 months after injury (range, 0.25-8 months). Surgery was performed in isolated tears of the subscapularis tendon

Figure 7. The delay between trauma and surgical intervention was inversely proportional to the improvement in the Constant score. The Spearman coefficient of correlation was –0.97 in isolated tears and –0.89 in combined tears (P = .01).

nearly twice as fast as in combined subscapularis tears (Table 1). The delay between trauma and surgical intervention was inversely proportional to the improvement in the Constant score. The Spearman coefficient of correlation was –0.97 in isolated tears and –0.89 in combined tears. The correlation was significant at the .01 level (Figure 7). Complications were as follows: 1 case of osteoarthrosis of the shoulder in a 66-year-old patient, 1 joint infection,

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and 1 suture granuloma. One patient with delayed mobilization due to postoperative hematoma developed a stiff, painful shoulder and had to be mobilized under anesthesia. A re-examination after 3 years showed no deterioration of the results. The patient with a frozen shoulder recovered after that time period.

DISCUSSION Isolated and combined subscapularis tendon tears are often difficult to diagnose through clinical examination alone. Diffuse pain in the affected shoulder often prevents a detailed examination that may reveal classic signs such as increased passive external rotation or a positive lift-off or apprehension test result caused by weakness of internal rotation as well as anterior instability.10,25,26 Therefore, the combination of a detailed examination, radiographs, dynamic sonography, MRI, arthroscopy, and anamnesis, with typical mechanism of injury—forceful external rotation and hyperextension of the abducted arm—leads to the correct diagnosis.22 At postoperative follow-up, the Constant score and the patients’ subjective contentment were better in subjects with isolated subscapularis tendon tears than in subjects with combined tears including the supraspinatus tendon. Warner et al34 reported on 19 patients with anterosuperior lesions of the rotator cuff, and Gerber and Rippstein17 summarized the European experience from 7 different medical centers regarding 56 cases with combined lesions of the subscapularis and supraspinatus tendons. The results were similar to our study, indicating that the prognosis for anterosuperior tears is comparatively inferior to the prognosis for isolated subscapularis tendon lesions. This finding may be explained by various reasons. The main reason for the worse result of patients with combined tears compared to those with isolated tears is the limited abduction of the operated arm.5 In the isolated tear group, abduction greater than 150° was possible in 14 patients and in the combined tear group, only in 8 patients. On the other hand, only 1 patient in the isolated tear group had a limited abduction less than 120°, compared with 6 patients in the combined tear group. Similar results were reported by Frankle and Cofield12 on 24 anterosuperior lesions of 301 rotator cuff repairs performed over a period of 5 years. Average postoperative abduction was 134°, and 25% of patients had significant weakness and pain. The second reason for the worse result of combined tears may be the longer delay between trauma and definitive treatment. Surgery was performed on isolated tears twice as fast after injury as on combined tears. In particular, patients with total isolated tears had the shortest delay (22 weeks) between trauma and surgical intervention.22 Patients with this tear pattern may have consulted a specialized physician immediately because of the more powerful injury mechanism and acute pain in total, compared with partial, subscapularis tendon tears. Studies have shown a significant correlation between the outcome and the duration of symptoms until surgery, as well as the


appearance of severe fatty degeneration and atrophy of the subscapularis muscle on MRI.14,15,19,34 Our data suggest that there might exist a threshold for both tear patterns: an improvement of at least 40 points in the Constant score was seen only in patients with a maximum delay of 3 months (for isolated tears) or 4 months (for combined tears) (Figure 7). Warner et al found in 19 patients with anterosuperior rotator cuff tears that repair before 6 months was associated with a better functional outcome as the result of less involution of muscle and tendon tissue.34 The deterioration in results as the delay of diagnosis increases serves to emphasize the need for early diagnosis after injury. Another reason for the better results in isolated compared with combined tears in our study may have been the difference in age of both groups. The group with combined tears was already older (average 55 years compared with 45 years in the isolated group), a characteristic that could be associated with more degenerative changes of the tendinous tissue. Several studies have shown an age-related prevalence of rotator cuff tears and reduced tendon quality in older patients.13,27,28,32,35 Finally, the treatment of isolated subscapularis tendon tears is less invasive. All isolated tears were able to be treated using only the deltopectoral groove approach. For the treatment of 8 combined tears with involvement of the supraspinatus tendon, an additional superior approach was necessary. The comparison of partial and total subscapularis tendon tears has shown better preoperative Constant scores and less improvement in patients with partial tears.22 Because of the lack of a control group, we cannot recommend surgical care for all patients. Particularly in partial subscapularis tendon tears, further studies comparing nonoperative and operative treatment are necessary. In conclusion, the most important factor for effective treatment of isolated and combined subscapularis tendon tears is a correct and early diagnosis.15,33 Accuracy in the trauma history and the clinical and radiographic examination is demanded.33 Young patients with isolated traumatic tears of the subscapularis tendon have the best prognostic factors.

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