Evidence that central sensitisation is present in patients with shoulder impingement syndrome and influences the outcome after surgery

Impingement syndrome in the shoulder has generally been considered to be a clinical condition of mechanical origin. However, anomalies exist between the pathology in the subacromial space and the degree of pain experienced. These may be explained by variations in the processing of nociceptive inputs between different patients. We investigated the evidence for augmented pain transmission (central sensitisation) in patients with impingement, and the relationship between pre-operative central sensitisation and the outcomes following arthroscopic subacromial decompression. We recruited 17 patients with unilateral impingement of the shoulder and 17 age- and gender-matched controls, all of whom underwent quantitative sensory testing to detect thresholds for mechanical stimuli, distinctions between sharp and blunt punctate stimuli, and heat pain. Additionally Oxford shoulder scores to assess pain and function, and PainDETECT questionnaires to identify 'neuropathic' and referred symptoms were completed. Patients completed these questionnaires pre-operatively and three months post-operatively. A significant proportion of patients awaiting subacromial decompression had referred pain radiating down the arm and had significant hyperalgesia to punctate stimulus of the skin compared with controls (unpaired t-test, p < 0.0001). These are felt to represent peripheral manifestations of augmented central pain processing (central sensitisation). The presence of either hyperalgesia or referred pain pre-operatively resulted in a significantly worse outcome from decompression three months after surgery (unpaired t-test, p = 0.04 and p = 0.005, respectively). These observations confirm the presence of central sensitisation in a proportion of patients with shoulder pain associated with impingement. Also, if patients had relatively high levels of central sensitisation pre-operatively, as indicated by higher levels of punctate hyperalgesia and/or referred pain, the outcome three months after subacromial decompression was significantly worse.     

关节镜下肩峰减压和肱二头肌长头腱切断治疗肩峰撞击综合征

目的 比较关节镜下肩峰减压加肱二头肌长头腱(LHBT)切断与单纯肩峰减压治疗肩峰撞击综合征的疗效,探讨LHB切断的适应证.方法 2006年2月至2008年5月,对42例(42肩)肩峰撞击综合征的患者采用关节镜治疗,其中24例行单纯肩峰减压成形手术(A组),18例行肩峰减压的同时附加LHBT切断(B组),患者平均年龄为65岁(50～75岁).两组患者的年龄、性别、疼痛程度、活动度及随访时间差异均无统计学意义.所有患者术前均有明显的肩关节疼痛、无力和活动受限,手术前后采用Constant评分评估患者功能恢复情况.结果 42例患者术后获平均15个月(12～24个月)随访,A组患者Constant总评分从术前平均38.3分(20～54分)改善至术后67.3分(47～89分),21例(87.5%)患者术后满意.B组患者Constant总评分从术前平均38.1分(18～54分)改善至术后68.6分(47～88分),16例(88.9%)患者术后满意,两组Constant总评分和满意率比较差异均尢统计学意义(P>0.05).B组术后2周疼痛缓解较A组有明显改善(P<0.01),但术后1年两组患者的疼痛评分差异无统计学意义(P>0.05).结论 关节镜下肩峰减压成形对肩峰撞击综合征有明显疗效,LHBT切断能短时间缓解肩关节的疼痛.经过半年以上保守治疗无效、肩关节严重疼痛不能缓解或疼痛加重、运动要求不高、肩关节镜下发现LHBT有病变的老年患者(>65岁)是LHBT切断的适应证.     

Impingement syndrome following total shoulder arthroplasty and humeral hemiarthroplasty: treatment with arthroscopic acromioplasty

Pain following total shoulder arthroplasty or humeral hemiarthroplasty is uncommon. Impingement syndrome can be an infrequent source of pain following shoulder arthroplasty. We retrospectively reviewed six patients with refractory impingement syndrome treated with arthroscopic acromioplasty following either total shoulder arthroplasty (four patients) or humeral hemiarthroplasty (two patients). Chronic impingement syndrome requiring acromioplasty affected 3% of all patients who underwent total shoulder arthroplasty or humeral hemiarthroplasty during the study period. A thorough history, physical examination, and radiographic findings made the clinical diagnosis of impingement syndrome. All six patients had positive impingement signs and a positive impingement test with subacromial lidocaine injection. Preoperative radiographs revealed a type II or III acromion and subacromial outlet narrowing in five of six patients. Other sources of shoulder pain including prosthesis loosening, infection, and rotator cuff tear were ruled out preoperatively by physical examination and radiographic findings, and were confirmed by arthroscopic examination. The results of arthroscopic acromioplasty were a reduction in pain from 7.5 preoperatively to 1.6 postoperatively, on a scale from 0 to 10. Five of six patients were completely satisfied with the results of their arthroscopic surgery. Overall, according to the University of California at Los Angeles end-result score, the results were rated as excellent or good in five patients, and unsatisfactory in one patient. Arthroscopic acromioplasty can be a successful technique for the treatment of chronic impingement syndrome following total shoulder arthroplasty or hemiarthroplasty in appropriate patients.Arthroscopy 1998 Oct;14(7):665-70     

Anterior internal impingement

Purpose: The source of pain in patients with a stable shoulder and clinical signs of impingement is traditionally thought to be subacromial or outlet impingement, as popularized by Neer. This report introduces the concept of anterior internal impingement in patients with signs and symptoms of classic impingement syndrome and arthroscopic evidence of articular-side partial rotator cuff tear. Contact that occurs between the fragmented undersurface of the rotator cuff and the anterosuperior labrum is the apparent source of pain in these patients. Type of Study: Case series. Methods: Ten patients with a primary symptom of pain and an arthroscopic finding of a partial rotator cuff tear were reviewed. Arthroscopic visualization of the subacromial space revealed no evidence of subacromial impingement or bursitis in any patient. All patients had clinical signs and symptoms of classic impingement. The initial part of the surgical procedure consisted of a complete diagnostic arthroscopy in a low-volume gas medium using a single posterior portal. While performing the Hawkins test, the locations of any areas of abnormal soft-tissue contact and impingement were observed directly. Results: There was anterior internal impingement in all 10 patients with partial-thickness rotator cuff tears. The abnormal and fragmented rotator cuff tissue made contact with the anterior superior labrum when the shoulder was visualized from the posterior portal while performing the Hawkins test. Preoperative magnetic resonance imaging correctly showed a partial-thickness rotator cuff tear in 20% of the cases. Conclusions: Recognition of anterior internal impingement as a clinical entity is important because magnetic resonance imaging results are often misleading. This is of particular importance in young patients with isolated lesions in whom arthroscopic acromioplasty and capsular reefing procedures would be unnecessary. When anterior internal impingement is recognized as the source of unresolved shoulder pain, patient selection for surgery and procedure selection can be improved.     

Can the impingement test predict outcome after arthroscopic subacromial decompression?

The impingement test, placement of local anesthetic in the subacromial space, is considered a useful tool in diagnosing impingement syndrome. The purpose of this study was to examine the predictive value of the impingement test with respect to outcome after arthroscopic subacromial decompression. Fifty-five patients who had a preoperative impingement test were evaluated at 3 and 12 months postoperatively. We noted 88% satisfactory results in patients in whom the impingement test was positive, with only 63% satisfactory results at 3 months and 60% satisfactory results at 12 months in patients in whom the impingement test was negative. Although workers' compensation patients tended to have lower scores than others, the impingement test result was more predictive of outcome than was compensation status. Impingement test results and preoperative American Shoulder and Elbow Surgeons scores were independent predictors of postoperative American Shoulder and Elbow Surgeons scores. Our evidence indicates that the impingement test can be used as a predictor of outcome for patients with impingement syndrome treated by arthroscopic subacromial decompression.     

Subacromial impingement: influence of coracoacromial arch geometry on shoulder function

OBJECTIVE: To find correlations between radiological coracoacromial arch geometry and shoulder function in patients with subacromial impingement syndrome. PATIENTS AND METHODS: During a prospective study of the efficacy of arthroscopic subacromial decompression, we evaluated the function of the treated and contralateral shoulders using Constant's functional score and confronted the results to several radiographic parameters reflecting coracoacromial arch geometry. RESULTS: Constant's score values were low (42 +/- 15) because of pain and a low level of activity. Males had significantly higher scores than females. Constant's score was unaffected (P > 0.05) by patient age, the side, the level of activity, or the duration of symptoms, but was significantly influenced by the orientation of the acromion with respect to the scapular spine and to the vertical scapular axis. The preoperative Constant's score was significantly higher in patients with a more horizontal acromion (P = 0.01). A very tight correlation was found between the preoperative Constant's score and the angle between the acromion and scapular spine (P = 0.0003). CONCLUSION: Based on our results, we defined an open and a closed coracoacromial arch geometry. Coracoacromial arch geometry is correlated with shoulder function syndrome and can assist in the interpretation of rotator cuff impingement.     

The role of acromion morphology in chronic subacromial impingement syndrome

This study investigated the role of acromion morphology in the aetiology of chronic subacromial impingement syndrome. Forty five patients with chronic subacromial impingement syndrome were included in the study. They were distributed into three groups according to their acromion types: six (13.3%) patients had type 1, 24 (533%) patients type 2 and 15 (333%) patients type 3 acromion. Constant scoring was used for clinical evaluation. Arthroscopic subacromial decompression was performed in all patients in the three groups, without performing any acromioplasty that would change the morphology of acromion. We then compared the average Constant scores changes in all three groups after arthroscopic subacromial decompression. The average follow-up was 28.6 months (range: 12-47). The average change in Constant score after arthroscopic subacromial decompression was 5830 in patients with type 1 acromion, 58.21 in those with type 2 and 54.07 in those with type 3. No significant difference was observed between the changes in the average Constant scores of the three groups (p > 0.005). The scores were significantly improved following arthroscopic subacromial decompression in all three groups (p < 0.005).In this study, acromion type was not found to have an important role in the aetiology of chronic impingement syndrome; arthroscopic subacromial decompression without simultaneous acromioplasty thus appears as an appropriate treatment.     

Internal rotation resistance strength test: a new diagnostic test to differentiate intra-articular pathology from outlet (Neer) impingement syndrome in the shoulder

This prospective study introduces a new sign to differentiate between outlet impingement and non-outlet (intra-articular) causes of shoulder pain in patients with positive impingement sign: the internal rotation resistance strength test (IRRST). It was hypothesized that positive test results are predictive of non-outlet impingement, whereas negative test results confirm outlet impingement. A prospective comparison between IRRST and arthroscopic findings of 115 consecutive patients showed the test to be highly accurate in differentiating between these two diagnoses (positive predictive value 88%, negative predictive value 96%, sensitivity 88%, specificity 96%, and accuracy 94.5%). The IRRST, in conjunction with impingement and apprehension signs, adds to our armamentarium of tests that distinguish between subacromial outlet impingement and intra-articular forms of pathology.     

Subacromial bursa block is an effective alternative to interscalene block for postoperative pain control after arthroscopic subacromial decompression: a randomized trial

Subacromial decompression surgery is associated with significant postoperative pain. We compared interscalene block (ISB) with subacromial bursa block (SBB). Sixty consecutive patients with subacromial impingement syndrome, scheduled for arthroscopic subacromial decompression surgery, were randomized into 3 groups receiving ISB (n = 19), SBB (n = 19), or no block (n = 15 [controls]). Patients with rotator cuff tears were excluded (n = 7). The postoperative consumption of morphine, time to the first bolus of morphine, oral analgesia, pain, sickness, and sedation scores were recorded. The pain scores in the ISB and SBB groups were lower than those in the control group in the first 12 hours postoperatively. The control group consumed more morphine (mean, 32.3 mg) compared with the SBB group (mean, 21.21 mg) and ISB group (mean, 14.00 mg) (P < .001). The time to first bolus was earlier in the control group (mean, 42.1 minutes) compared with both the SBB (mean, 92.6 minutes) and ISB (mean, 119.0 minutes) groups (P < .001). The oral analgesic intake was less in the SBB and ISB groups than in the controls (P = .004). Although ISB remains the gold standard, SBB provides effective, safe, and easily administered postoperative analgesia in patients with an intact rotator cuff undergoing arthroscopic subacromial decompression.     

Arthroscopic subacromial decompression for stage-II impingement

PURPOSE: To evaluate outcomes of arthroscopic subacromial decompression for stage-II impingement. METHODS: Records of 42 consecutive patients with stage-II impingement treated by arthroscopic subacromial decompression from January 2000 to February 2002 were reviewed. Clinical outcomes were measured using the UCLA shoulder rating scale, and radiological outcomes using anteroposterior and supraspinatus outlet shoulder radiographs. RESULTS: The mean follow-up period was 14.6 (range, 12-30) months. Using the UCLA scale, 14 (33%) patients had an excellent result, 21 (50%) had a good result, 4 (10%) had a fair result, and 3 (7%) had a poor result. Mean component scores for the UCLA scale were: 8.0 for pain, 8.8 for function, 4.5 for forward flexion, and 4.5 for strength. The mean extent of resection was 2.9 mm in the anteroposterior and 2.0 mm in the supraspinatus outlet radiographs. There was no correlation between the extent of acromial resection and the UCLA shoulder rating scores. CONCLUSION: Short-term results of arthroscopic subacromial decompression for stage-II impingement are favourable.     

Diagnosis of bursal‐side partial‐thickness rotator cuff tears

Objective: To study the clinical features and diagnosis of bursal‐side partial‐thickness rotator cuff tears. Methods: From August 1999 to June 2006, 38 patients with bursal‐side partial‐thickness rotator cuff tear were evaluated. Twenty‐eight men and ten women of average age 45.7 years (range, 18–69 years) with 11 left and 27 right shoulders were studied. According to the Ellman classification, 6 cases were classified as grade I, 7 as II and 25 as III. Physical and X‐ray examination, including anteroposterior and supraspinatus outlet views, were performed on both shoulders of all patients. Ultrasonography and MR examination were performed in 27 and 35 patients, respectively. Thirteen patients underwent arthroscopic subacromial decompression and debridement of the rotator cuff. Twenty five patients underwent arthroscopic or mini‐open subacromial decompression and rotator cuff repair. Results: All patients had shoulder pain, with 18 cases of night pain. No statistical difference in the incidence of night pain was found between the three groups. Strength of forward flexion and abduction of the affected shoulder was decreased in 25 patients. The Neer impingement sign was found in 35 cases (92.1%), Hawkins impingement sign in 27 (71.1%), tenderness of the greater tuberosity in 34 (89.5%), painful arc in 26 (68.4%), and traction test in 26 (68.4%). The positive rates for ultrasonography and MR were 48.1% and 74.3%, respectively. Conclusions: Long‐standing motion pain, impingement sign, painful arc, lock and crepitus in the subacromial space are suggestive of bursal‐side tears. MRI is much more accurate than ultrasonography. Fat‐suppressed T2‐weighted images must be included. Arthroscopy is still the gold standard for making the diagnosis.     

The relationship between clinical outcomes and the amount of arthroscopic acromial resection

Purpose: In 47 consecutive patients who had a shoulder impingement syndrome treated by arthroscopic subacromial decompression, we compared the functional outcome with the amount of the acromion resection. Type of Study: Prospective study. Methods: The inclusion criteria for patient selection was a chronic impingement syndrome unresolved by conservative treatment with an intact rotator cuff or with an irreparable rupture of the rotator cuff. The assessment was performed with the scoring system of Constant preoperatively and postoperatively. Quantitative measurements of the acromion resection were made by comparing preoperative and postoperative anteroposterior radiographic views, standardized under fluoroscopic control in order to become reproducible and comparable. There were 39 patients (41 shoulders) available for follow-up at 37 months. Results: The condition of the shoulder, concerning pain, motion and activities, was improved at the time of follow-up, the mean gain of the total functional score was 29 points/100. Age, side, activity, duration of pain before procedure and cuff statement had no influence on preoperative and postoperative Constant's score. The difference between preoperative and postoperative measurements of anterior acromion protuberance was significant. There was no correlation between the amount of the acromion resection and the improvement of Constant's score (P = .84). Conclusions: The origin of impingement syndrome is multi-factorial, and efficiency of arthroscopic decompression may not be only due to the amount of acromion resection. From these results and a literature review, this study analyzes several morphologic factors, which could explain the good results of arthroscopic subacromial decompression in impingement syndrome.     

Open versus arthroscopic subacromial decompression: a prospective, randomized study of 34 patients followed for 8 years

In a randomized prospective study, we selected 15 patients for arthroscopic subacromial decompression (ASD) and 19 patients for open subacromial decompression (OSD). All had impingement syndrome (Neer grade II), and had been unsuccessfully treated without surgery for more than 6 months. The UCLA Shoulder Rating Scale, Visual Analogue Scales for pain and satisfaction, isokinetic dynamometer recordings and physical testing were assessed preoperatively and at 1 (except isokinetic testing), 3, 6, and 12 months, and, finally, 8 years after surgery. We found essentially no differences in the clinical tests between the groups during this period. The use of ASD or OSD seems to be a matter of cosmesis and personal preference.     

Bilateral Os Acromiale in a Division I Basketball Player

An unfused acromial epiphysis, called os acromiale, can become unstable and mobile when the deltoid contracts. This may cause pain and lead to impingement syndrome and rotator cuff tearing. After sustaining a direct blow to the right shoulder, a male division I basketball player was diagnosed with impingement syndrome and an os acromiale. Following failed conservative treatment, the athlete underwent arthroscopic subacromial decompression & debridement of the loose os acromiale in the right shoulder. One year later, following a fall on the left shoulder, the athlete was diagnosed with os acromiale, impingement syndrome and a superior labrum anterior-posterior (SLAP) lesion. Arthroscopic repair of the unstable type II SLAP lesion, together, with arthroscopic subacromial decompression, and resection of the os acromiale was performed on the left shoulder. Both surgeries were successful and the athlete was able to return to competition subsequent to completing a progressive shoulder rehabilitation program. Symptomatic os acromiale is rarely seen in young athletes. However, proper diagnosis and management is necessary for a successful recovery. Os acromiale should be considered as a part of the differential diagnosis in any athlete with rotator cuff impingement symptoms.Key Words: Injury, shoulder, athlete, rehabilitation, diagnosis     

Open versus arthroscopic subacromial decompression

In a randomized prospective study, we selected 15 patients for arthroscopic subacromial decompression (ASD) and 19 patients for open subacromial decompression (OSD). All had impingement syndrome (Neer grade II), and had been unsuccessfully treated without surgery for more than 6 months. The UCLA Shoulder Rating Scale, Visual Analogue Scales for pain and satisfaction, isokinetic dynamometer recordings and physical testing were assessed preoperatively and at 1 (except isokinetic testing), 3, 6, and 12 months, and, finally, 8 years after surgery. We found essentially no differences in the clinical tests between the groups during this period. The use of ASD or OSD seems to be a matter of cosmesis and personal preference.     

Open versus arthroscopic subacromial decompressionA prospective,randomized study of 34 patients followed for 8 years

In a randomized prospective study, we selected 15 patients for arthroscopic subacromial decompression (ASD) and 19 patients for open subacromial decompression (OSD). All had impingement syndrome (Neer grade II), and had been unsuccessfully treated without surgery for more than 6 months. The UCLA Shoulder Rating Scale, Visual Analogue Scales for pain and satisfaction, isokinetic dynamometer recordings and physical testing were assessed preoperatively and at 1 (except isokinetic testing), 3, 6, and 12 months, and, finally, 8 years after surgery. We found essentially no differences in the clinical tests between the groups during this period. The use of ASD or OSD seems to be a matter of cosmesis and personal preference.     

Subacromial plica as a cause of impingement in the shoulder

The subacromial bursa is the largest bursa in the body. In 1934, Codman described the presence of subacromial plicae, similar to the suprapatellar plicae found in the knee. It is recognized that plicae in the knee can cause anterior knee pain with impingement against the patella in young persons. We investigated the possibility that a similar situation exists with plicae of the subacromial bursa. The aims of this study were to document the prevalence of bursal plicae seen at bursoscopy during arthroscopic subacromial decompression of the shoulder and to assess whether there is any pattern in the occurrence of these plicae, as well as the relationship to impingement lesions seen at bursoscopy. Between January 1996 and July 2001, all cases undergoing arthroscopic decompression were evaluated for anatomic-pathologic changes of the subacromial bursa, including the presence of plicae and impingement lesions. A total of 1732 cases complying with inclusion criteria were recorded, with plicae observed in 104 (6.0%). The occurrence of plicae showed a highly significant younger age predilection (P = .0008, chi(2) test) but no differences between sexes or sides. The occurrence of subacromial plicae was highly associated with the combined severity of the impingement lesion on the acromial and bursal side. Plicae were most common in shoulders showing an impingement lesion on the cuff bursal side, with no impingement lesion on the acromial side. The odds of the impingement lesion being milder on the acromial side was 3.41 times higher in shoulders with a plica compared with shoulders without a plica. This suggests that impingement of the cuff may be due to the plica itself. This study is the first to describe the presence of subacromial plicae in living subjects and correlates with previous anatomic studies. The younger age predominance correlates with the findings of plicae in the knee. Our findings suggest that subacromial plicae may be a cause of impingement in young patients.     

Subacromial osteochondroma

The most common cause of impingement syndrome is mechanical irritation of the subacromial bursa and rotator cuff by the coracoacromial arch. Offending structures include the undersurface of the anterolateral acromion, coracoacromial ligament, and the undersurface of the distal clavicle. We present a case of impingement syndrome caused by mechanical irritation of the rotator cuff by a subacromial osteochondroma that was successfully treated with arthroscopic resection. Osteochondroma is the second most common benign bone tumor following nonossifying fibroma. These lesions are thought to arise from aberrant growth of normal epiphyseal growth plate cartilage. Ninety percent of osteochondromas arise from the metaphyseal regions of long bones (eg, distal femur, proximal tibia, or proximal humerus). Scapular involvement accounts for 3.0% to 4.6% of all reported osteochondromas. These lesions represent 14.4% of all tumors of the scapula and 49% of benign scapular tumors, making them the most common benign bone tumors of the scapula. Our patient failed nonoperative management of his subacromial osteochondroma. The concern for malignant transformation was low, as the patient's pain had been consistent for the past 15 years. Although his pain had been largely unchanged for more than a decade, he elected to undergo resection so that he could resume the hobbies that his pain had forced him to abandon. He reported substantial pain relief and restoration of function following arthroscopic resection and subacromial decompression, reinforcing mechanical irritation of the rotator cuff as the source of his shoulder pain and dysfunction. To our knowledge, this is the first report of arthroscopic resection of a subacromial osteochondroma.     

Long-term results of arthroscopic resection of the distal clavicle with concomitant subacromial decompression

Purpose: The goal of the study was to evaluate the long-term outcome of combined arthroscopic distal clavicle excision and subacromial decompression. Type of Study: Retrospective, long-term cohort evaluation. Methods: Twenty patients with an average follow-up of 6 years (range, 3.9 to 9 years) were reviewed. All patients had ipsilateral impingement syndrome and acromioclavicular joint disease at the time of surgery and underwent arthroscopic subacromial decompression combined with arthroscopic distal clavicle excision. All patients returned for evaluation in person, in addition to filling out a questionnaire incorporating the University of California, Los Angeles (UCLA), and Constant scoring systems. Preoperative and postoperative radiographs were available for all patients. Results: Postoperatively, all patients had pain relief and were satisfied with the result. The average postoperative UCLA Shoulder score was 29.8 ± 0.6, compared with 17.5 ± 3.0 before surgery (P = .001). The Constant Shoulder score averaged 98.5 ± 2.1 postoperatively, compared with 70.5 ± 11.2 preoperatively (P = .001). There was 100% good to excellent results using both scoring systems. Individual components of the UCLA scoring system (pain, function, and power) all showed significant postoperative improvement (P = .001). Constant categories of pain, activities of daily living, range of motion, and power also improved. Follow-up radiographs showed maintenance of the resected distal clavicle in 19 patients. Five patients (25%) had radiographic evidence of calcific density distal to the resected clavicle but were asymptomatic. Conclusions: The long-term results of arthroscopic resection of the distal clavicle with concomitant subacromial decompression are uniformly good or excellent. Impingement and acromioclavicular joint disease frequently coexist and should be identified and treated concurrently.     

Revisions after arthroscopic interventions in the subacromial space

PROBLEM: In the present study, we evaluated the failure and revisions rates after arthroscopic subacromial decompression (SAD). METHOD: We examined 83 patients who were treated with arthroscopic subacromial decompression for primary shoulder impingement (stage II and stage III according to Neer) at an average follow-up time of 30 months. Hereby, special attention was paid to the revision operations resulting from our treatment. RESULTS: In patients with impingement stage II, the mean follow-up Constant-score was 84.7 (SD +/- 16.7) while in patients with impingement stage III it was 78.0 (SD +/- 21.8). In ten patients (12%) revision operation had to be performed, nine of them with initial stage II impingement and one with initial stage III impingement. Reasons for revisions were persisting or increasing pain as well as functional dissatisfaction. At the follow up examination, six of these revised patients (60%) were satisfied with the result. The mean follow up Constant-score in the revised patients was 77.3 (SD +/- 17.4). In 60% of the revised patients the necessity for the revision operation was directly related to the technical problems at the primary operation, in 40% we found reasons not related to the primary SAD. CONCLUSIONS: Technical falls are the most common cause for the need of revision operations after SAD. This demonstrates how demanding this kind of operation procedure is. In case of revision operations individual strategies should be developed in which the decision whether to perform arthroscopic or open revision procedures is of special importance.