Arthroscopic footprint reconstruction of bursal-side delaminated rotator cuff tears using the suture-bridge technique

For a bursal-side retracted laminated rotator cuff tear, simple repair of the retracted bursal-side rotator cuff might be insufficient because the repaired tendon could remain as an intratendinous tear of the rotator cuff. We present a repair method for intratendinous rotator cuff tears using the suture-bridge technique. We believe that this method helps to preserve the remnant rotator cuff tendon without tissue damage and restores the normal rotator cuff footprint in bursal-side delaminated rotator cuff tears.     

Cystic changes at supraspinatus and infraspinatus tendon insertion sites: association with age and rotator cuff disorders in 238 patients

PURPOSE: To retrospectively determine the frequency of posterior and anterior cystic abnormalities at rotator cuff insertion site on the greater tuberosity and to determine their relationship to patient age and rotator cuff disorders. MATERIALS AND METHODS: Institutional review board approval was given; informed consent was waived. The study was HIPAA compliant. In 238 patients with rotator cuff diagnoses at surgery, preoperative magnetic resonance (MR) imaging studies were reviewed to localize osseous cystic changes as anterior (supraspinatus insertion site) or posterior (infraspinatus insertion site) on the greater tuberosity. If rotator cuff tear was present, tendon retraction and location of partial tear (articular or bursal surface) were recorded. Two radiologists reached conclusions by consensus. Locations of cysts were correlated to surgical cuff diagnoses: no tear, tendinopathy, partial-thickness tear, and complete tear. Prospective interpretations from original MR reports were compared with surgical results. Statistical analyses included one-way analysis of variance, chi(2), Fisher exact, and Student t tests, as well as logistic regression and receiver operating characteristic curve comparison. RESULTS: There were 238 consecutive patients (150 men, 88 women; mean age, 43 years). Cysts were located at or near footprint of cuff tendon and demonstrated fluid or soft-tissue signal intensities. Posterior cysts occurred in 56.7% of shoulders and showed no statistical correlation to age or cuff diagnosis. Anterior cysts occurred in 22.7% of shoulders and were strongly associated with cuff disorders (P<.001). Controlling for cuff disorders, there was no relationship between anterior cysts and age (P>.50). Anterior cysts were more common in partial-thickness articular (48%) than in bursal (13%) tears (P<.001). CONCLUSION: Posterior cysts were more common than anterior cysts and showed nearly random distribution among patients, regardless of age and cuff diagnosis. Anterior cysts were closely associated with cuff disorders.     

MR evaluation of subscapularis tears.

PURPOSE: The purpose of this work was to describe the MR appearance of tears of the subscapularis tendon and compare the usefulness of different imaging planes as well as note the association of subscapularis tears with other rotator cuff tears and biceps tendon dislocations. METHOD: MR studies at 1.5 T over an 8 year interval were retrospectively assessed for the presence of a rotator cuff tear and/or tear of the subscapularis tendon. Images that showed a subscapularis tear were reviewed for the presence of a visible tear separately on the axial, coronal, and sagittal images. The MR studies were also evaluated for associated tears of the supraspinatus, infraspinatus, and teres minor muscles as well as biceps tendon dislocation and the "naked humerus sign" on coronal images. Last, clinical records and surgical reports were reviewed. RESULTS: Forty-five (2%) of 2,167 rotator cuff tears involved the subscapularis; 27% were partial and 73% were complete tears. Tears were best seen in the sagittal oblique plane. Almost all subscapularis tears were an extension of typical rotator cuff tears: supraspinatus in 35 patients (79%), extending into infraspinatus tears in 25 (56%) and into teres minor tears in 2 patients (4%). Bicipital dislocations were seen in 22 patients (49%), and three complete tears of the biceps (7%) were noted as well. The naked humerus sign was demonstrated in 31 patients (69%). Surgical reports that confirmed the MR findings were available for 15 patients. CONCLUSION: About 2% of rotator cuff tears involve the subscapularis tendon. Most subscapularis tears are extensions of supraspinatus tears and frequently involve the biceps tendon.     

Humeral head cysts and rotator cuff tears: an MR arthrographic study

Objective Humeral tuberosity cysts are a common finding, with previous reports suggesting they are related to rotator cuff tear or aging. The aim of this study was to investigate the characteristics of cysts in the tuberosities of the humeral head and their relationship with rotator cuff tear and age.Design and patients Shoulder MR arthrograms were reviewed in 120 consecutive patients—83 males (mean age 38.0, range 19–59 years) and 37 females (mean age 41.2, range 15–59 years). Patients were referred for investigation of a variety of conditions, and instability was suspected in only a minority of cases. MR was performed before and after direct arthrography with 0.01% solution of gadolinium. Cysts were defined as well-demarcated circular/ovoid foci in two planes that demonstrated high signal on pre-arthrographic T2W sequences. Location, size and numbers of cysts and post-arthrographic enhancement were documented, along with the location of rotator cuff tears, if present.Results Cysts in the tuberosities of the humerus were identified in 84 patients (70%), and were seen seven times more frequently in the posterior aspect of the greater tuberosity than anteriorly. Most cysts (94%) demonstrated communication with the joint post-arthrogram. Rotator cuff tears were present in 36 patients, and 79% of all tears occurred in supraspinatus tendon. There was no significant difference in the occurrence of cysts between patients older or younger than age 40 or between genders, but rotator cuff tears were seen significantly more often in the older age group (p<0.01). Tuberosity cysts and rotator cuff tears did not appear to be related (p=0.55). However, whilst this lack of association was quite obvious posteriorly (p=0.84), the trend in the anterior aspect of the greater tuberosity is not as clear (p=0.14).Conclusions Humeral cysts are most often located in the posterior aspect of the greater tuberosity, communicate with the joint space and, in this location, are not related to aging or rotator cuff tear.An erratum to this article can be found at     

Histopathology of rotator cuff tears

The pathogenesis of rotator cuff tears is multifactorial. Tendon abnormalities of the rotator cuff include alteration of collagen fiber structure, tenocytes, cellularity, and vascularity. Ruptured tendons show marked collagen degeneration and disordered arrangement of collagen fibers. Fibroblast population decreases as the size of the tear in the rotator cuff increases. The larger fibroblast population seen in the smaller tears is also actively proliferating and is part of an active reparative process. Inflammatory cell infiltrate correlates inversely to rotator cuff tear size in the torn supraspinatus tendon samples, with larger tears showing a marked reduction in all cell types. As tear size increase, there is also a progressive decrease in the number of blood vessels. Whether rotator cuff tear heals spontaneously is an important pathologic and clinical question. Histologic changes indicative of repair and inflammation lead to consider biological options in addition to biomechanical treatment of the rotator cuff tears.     

Rim-rent tear of the rotator cuff: a common and easily overlooked partial tear

OBJECTIVE: The purpose of this study was to determine the incidence of rim-rent rotator cuff tears in a population of patients referred for shoulder MRI and to determine the sensitivity of MRI for the detection of these tears. CONCLUSION: Rim-rent tears are a common type of partial-thickness rotator cuff tear, much more commonly present than has been previously reported. In particular, infraspinatus rim-rent tears are more common than previously believed. Rim-rent tears of the infraspinatus tendon and those involving the anterior-most fibers of the supraspinatus tendon are commonly overlooked on MRI, possibly because of failure to appreciate the high incidence of these types of tears and failure to inspect the anterior-most fibers of the rotator cuff.     

Sonography of the postoperative rotator cuff

In experienced hands, high-resolution real-time sonography has been shown to be an accurate noninvasive method for diagnosis of rotator cuff tears. The sonographic appearance of the postoperative rotator cuff has not been previously reported. Forty postoperative patients were studied sonographically 1 week to 6 years after rotator cuff repair. The postoperative rotator cuff is abnormally echogenic and can be very similar in appearance to a small rotator cuff tear in a nonoperated patient. Soft-tissue planes about the tendon are distorted or absent. Criteria for diagnosis of retear must be different from those used in detecting new tears in a nonoperated cuff. Postoperative echogenicity is normal, but the finding of a defect or gap within the rotator cuff tendon is the only accurate sign of a recurrent rotator cuff tear.     

Surgically repaired massive rotator cuff tears: MRI of tendon integrity, muscle fatty degeneration, and muscle atrophy correlated with intraoperative and clinical findings

OBJECTIVE: Our goal in this study was to evaluate by means of MRI the clinical significance of tendon integrity, muscle fatty degeneration, and muscle atrophy in surgically repaired massive rotator cuff tears and to correlate these and other prognostic factors with intraoperative and clinical findings. MATERIALS AND METHODS: Twenty-eight surgically proven massive rotator cuff tears were retrospectively included in the study. Twenty-two patients underwent complete repair, and six patients underwent partial repair. Preoperative and postoperative clinical assessment was performed by using the University of California at Los Angeles score. Preoperative and postoperative MRI studies were evaluated for the presence and extent of rotator cuff tear and for the degree of fatty degeneration and atrophy of the rotator cuff muscles. RESULTS: At a mean 44.4 months' follow-up, 20 patients (71.4%) had a favorable result. A total of 25 patients (89.2%) showed postoperative full-thickness rotator cuff tear, 19 of which were reruptures. A sagittal preoperative rotator cuff tear of less than or equal to 34 mm showed a specificity of 100% for predicting a favorable outcome. A coronal postoperative rotator cuff tear of less than or equal to 34 mm showed a specificity of 85.7% and a positive predictive value of 92.9% for predicting a favorable outcome. A postoperative fatty degeneration of infraspinatus muscle less than or equal to 2 had a specificity of 87.5% and a positive predictive value of 90.9% for predicting a favorable outcome. CONCLUSION: Open repair of massive rotator cuff tears may reach a favorable outcome in a significant proportion of patients, despite a high rate of recurrent or residual tears. Oblique coronal sizes of the recurrent or residual tear of less than or equal to 34 mm and postoperative fatty degenerations of infraspinatus muscle of less than or equal to 2 may allow a favorable outcome.     

Rotator cuff tears in asymptomatic individuals: a clinical and ultrasonographic screening study

OBJECTIVE: To determine the prevalence and clinical impact of rotator cuff tears in asymptomatic volunteers. MATERIALS AND METHODS: Sonographic examinations of the shoulder of 212 asymptomatic individuals between 18 and 85 years old were performed by a single experienced operator. The prevalence and location of complete rotator cuff tears were evaluated. The clinical assessment was based on the Constant Score. Magnetic resonance imaging (MRI) of the shoulder was obtained in those patients where US showed rotator cuff pathology. RESULTS: Ultrasound showed a complete rupture of the supraspinatus tendon in 6% of 212 patients from 56 to 83 years of age (mean: 67 years). MRI confirmed a complete rupture of the supraspinatus tendon in 90%. All patients reported no functional deficits, although strength was significantly lower in the patient group with complete supraspinatus tendon tear (P < 0.01). CONCLUSION: There is a higher prevalence in older individuals of rotator cuff tendon tears that cause no pain or decrease in activities of daily living.     

Value of CT bursography in the evaluation of rotator cuff tears

PURPOSE: To describe the technique and assess the value of subacromial CT bursography in patients with partial surface tear of the rotator cuff tendon. MATERIALS AND METHODS: 15 patients with shoulder pain suggestive of tendinopathy or tear of the rotator cuff were evaluated with subacromial CT bursography. RESULTS: Subacromial CT bursography was normal in 4 patients. Partial surface tear was detected in 7 patients [irregularities (n=2), defect (n=2), superficial tear (n=3)]. Full thickness tear was detected in 4 patients. CONCLUSION: The authors described the technique for subacromial CT bursography to visualize partial surface tears of the rotator cuff tendon. This simple and reliable technique could be an alternative to MR imaging, especially when MR evaluation is not possible.     

Deltoid muscle and tendon tears in patients with chronic rotator cuff tears

Purpose To describe the magnetic resonance imaging (MRI) appearances of tears of the deltoid muscle and tendon in patients with rotator cuff tears and without a prior history of shoulder surgery. Materials and methods Deltoid tears diagnosed on MR examinations were prospectively recorded between February 2003 through June 2004. The images of these patients were then retrospectively reviewed to determine the location of the deltoid tear, the presence of rotator cuff tears, tendon retraction, muscle atrophy, degree of humeral head subluxation, bony erosive changes involving the undersurface of the acromion, and the presence of edema or fluid-like signal intensity in the deltoid muscle and overlying subcutaneous tissues. Results There were 24 (0.3%) patients with deltoid tears; nine men and 15 women. The age range was 54 to 87 (average 73) years. The right side was involved in 20 cases, and the left in four cases. Fifteen patients had full thickness and nine had partial thickness tears of the deltoid. Shoulder pain was the most common presenting symptom. The physical examination revealed a defect in the region of the deltoid in two patients. Nineteen patients had tears in the muscle belly near the musculotendinous junction, and five had avulsion of the tendon from the acromial origin. Full thickness rotator cuff tears were present in all of the patients, and 22 patients had associated muscle atrophy. Subcutaneous edema and fluid-like signal was present in 15 patients. Conclusion Tears of the deltoid muscle or tendon is an unusual finding, but they can be seen in patients with chronic massive rotator cuff tears. Partial thickness tears tend to involve the undersurface of the deltoid muscle and tendon. Associated findings such as intramuscular cyst or ganglion in the deltoid muscle belly and subcutaneous edema or fluid-like signal overlying the deltoid in a patient with a rotator cuff tear should raise the suspicion of a deltoid tear.     

Ultrasonography of the tendons of the shoulder

The purpose of the present study was to compare ultrasonographic signs with macroscopic and histological findings in lesions of the rotator cuff and the biceps tendon. Twenty-six shoulder joints from 10 male and 3 female cadavers, ranging in age from 40 to 89 years (mean 65.9), were examined with a linear array real-time ultrasonographic scanner provided with a 7.5 MHz transducer. Arthrotomy and histological preparations were made after ultrasonography. Thinning and discontinuity of echogenic homogenicity of the tendons of the rotator cuff were the most reliable ultrasonographic signs of a total tear of the tendon, but focal hyper- and hypo-echogenic changes of the tendons of the rotator cuff were unreliable criteria. Partial tears of the rotator cuff were difficult to determine with static ultrasonograms. Ultrasonography readily revealed discontinuity of echogenic homogenicity of the biceps tendon as a sign of a rupture of the tendon, which was commonly associated with rotator cuff tears.     

Association of biceps tendon tears with rotator cuff abnormalities: degree of correlation with tears of the anterior and superior portions of the rotator cuff

OBJECTIVE: This study was performed to examine the relationship and association of abnormalities seen in the long head of the biceps brachii tendon to abnormal findings in the rotator cuff. MATERIALS AND METHODS: One hundred eleven patients underwent MR imaging for shoulder pain followed by arthroscopic or open shoulder surgery from January 1997 to December 2000. Patients were identified by a retrospective search, and all consecutive patients having undergone both MR imaging and surgery were included in the patient cohort. Official MR imaging interpretations were compared with operative reports, and all findings were recorded. RESULTS: Twenty-three patients were identified with partial- or full-thickness tears of the long head of the biceps tendon. The sensitivity, specificity, and accuracy of unenhanced MR imaging of the shoulder for detecting these bicipital tears were 52%, 86%, and 79%, respectively. When a tear was present in the biceps tendon, the prevalence of supraspinatous, infraspinatus, and subscapularis tendon tears was 96.2%, 34.6%, and 47.1%, respectively. Patients with biceps tendon tears were significantly more likely to also have subscapularis tendon tears (p < 0.0001) and supraspinatous tendon tears (p < 0.008) than those patients who did not have biceps tendon tears. No significant relationship was found between the presence or absence of a biceps tendon tear and the presence or absence of a infraspinatus or teres minor tendon tear (p = 0.17). CONCLUSION: Tears of the long head of the biceps tendon have a statistically significant association with tears of the anterior and superior rotator cuff and are highly correlated with tears of the supraspinatous and subscapularis tendons. When tears of these tendons are detected, specific attention directed toward the long biceps tendon is warranted to characterize the status of this structure that provides additional stability to the shoulder joint.     

The rotator cuff functional index

BACKGROUND: Despite improvements in the clinical assessment of rotator cuff injuries, shortcomings exist in diagnosing rotator cuff tears. PURPOSE: To formulate a clinical rotator cuff functional index for predicting rotator cuff tears based on handheld dynamometer measurements for shoulder strength testing and to assess its ability to diagnose a rotator cuff tear. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: Preoperative handheld dynamometer measurements, including supraspinatus, external rotation, internal rotation, adduction, and lift-off force, were compared in 100 patients with full-thickness rotator cuff tears (> 1.0 cm) and 100 patients with no rotator cuff injury (confirmed by arthroscopy). Using multiple logistic regression analysis, the rotator cuff functional index and index for rotator cuff tear size were formulated in which 100 represented excellent rotator cuff function and less than 0 indicated a full-thickness supraspinatus tear. Each patient's index was calculated to determine its clinical value in predicting a rotator cuff tear; the Pearson correlation coefficient was established for the rotator cuff functional index for rotator cuff size. RESULTS: Two handheld dynamometer measurements predicted a rotator cuff tear (P < .001, r = 0.53), with rotator cuff functional index = 1.27 * supraspinatus (N) - 0.72 * adduction (N) - 11.6, but not tear size (r = 0.38). In predicting a rotator cuff tear (rotator cuff functional index < 0 = rotator cuff tear; rotator cuff functional index > 0 = no tear), the rotator cuff functional index had 83% sensitivity, 79% specificity, 80% positive predictive value, 82% negative predictive value, likelihood ratio of 4.0 for a positive test result and 0.2 for a negative test result and an accuracy of 81%. CONCLUSION: The 2 most useful tests for determining a rotator cuff tear with a handheld dynamometer were supraspinatus force and adduction force (as negative control). A functional index based on these measurements was able to rule out a rotator cuff tear and predict the presence but not the size of the tear.     

Trabecular microstructure and surface changes in the greater tuberosity in rotator cuff tears

OBJECTIVE: When planning surgery in patients with rotator cuff tear, strength of bone at the tendon insertion and trabecular bone structure in the greater tuberosity are usually taken into consideration. We investigated radiographic changes in bone structure of the greater tuberosity in rotator cuff tears. DESIGN: Twenty-two human cadaveric shoulders from subjects ranging from 55 to 75 years of age were obtained. The integrity of the rotator cuff was examined by sonography to determine if it is intact without any tear, or torn partially or completely. The humeral head was sectioned in 3 mm thick coronal slab sections and microradiographed. After digitization of the microradiographs and imaging processing with in-house semi-automated image processing software tools developed using software interfaces on a Sun workstation, the trabecular histomorphometrical structural parameters and connectivity in the greater tuberosity were quantified. The degenerative changes on the surface of the greater tuberosity were interpreted blindly by 2 independent readers. RESULTS: Among the 22 shoulder specimens, the rotator cuff was found intact in 10 shoulders, partially in 7 and fully torn in 5. Statistically significant loss in apparent trabecular bone volume fraction, number of trabecular nodes, and number of trabecular branches, and a statistically significant increase in apparent trabecular separation and number of trabecular free ends were found in the greater tuberosity of the shoulders with tears. The loss was greater in association with full tear than in partial tear. Thickening of the cortical margin of the enthesis, irregularity of its surface, and calcification beyond the tidemark were observed in 2 (20%) shoulders with intact rotator cuff, in 6 (86%) shoulders with partial tear, and in 5 (100%) shoulders with full tear. CONCLUSIONS: Rotator cuff tears are associated with degenerative changes on the bone surface and with disuse osteopenia of the greater tuberosity. Aging, degenerative enthesopathy of the supraspinatus tendon, and rotator cuff tears appear closely related.     

Interobserver agreement in the classification of rotator cuff tears

BACKGROUND: Six classification systems have been proposed for describing rotator cuff tears designed to help understand their natural history and make treatment decisions. PURPOSE: To assess the interobserver variation for these classification systems and identify the method with the best interobserver agreement. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: Six rotator cuff tear classification systems were identified in a literature search. The components of these systems included partial-thickness rotator cuff tears and classification by size, shape, configuration, number of tendons involved, and by extent, topography, and nature of the biceps. Twelve fellowship-trained orthopaedic surgeons who each perform at least 30 rotator cuff repairs per year reviewed arthroscopy videos from 30 patients with a random assortment of rotator cuff tears and classified them by the 6 classification systems. Interobserver variation was determined by a kappa analysis. RESULTS: Interobserver agreement was high when distinguishing between full-thickness and partial-thickness tears (0.95, kappa = 0.85). The investigators agreed on the side (articular vs bursal) of involvement for partial-thickness tears (observed agreement 0.92, kappa = 0.85) but could not agree when classifying the depth of the partial-thickness tear (observed agreement 0.49, kappa = 0.19). The best agreement for full-thickness tears was seen when the tear was classified by topography (degree of retraction) in the frontal plane (observed agreement 0.70, kappa = 0.54). CONCLUSION: With the exception of distinguishing partial-thickness from full-thickness rotator cuff tears and identifying the side (articular vs bursal) of involvement with partial-thickness tears, currently described rotator cuff classification systems have little interobserver agreement among experienced shoulder surgeons. Researchers should consider describing full-thickness rotator cuff tears by topography (degree of retraction) in the frontal plane.     

合并肩袖损伤的肩关节盂唇损伤的临床特征

目的 分析合并肩袖损伤的肩关节盂唇损伤患者的临床特征,提出其发病规律与病变特点,为临床微创手术治疗提供参考. 方法 本组50例,其中男28例,女22例;年龄30～58岁,平均45岁.记录患者的损伤机制、损伤时间、临床症状、体征,摄X线片和MRI.根据临床诊断,采用肩关节镜微创手术修复盂唇和肩袖损伤,记录损伤部位、范围及程度并进行分析.本组表现前盂唇损伤37例,上盂唇撕裂8例,后盂唇损伤5例;肩袖损伤轻度36例,中度10例,重度3例,特大裂口1例.其中肩袖前侧(冈上肌前侧)损伤21例,中部损伤(冈上肌与冈下肌部)16例,后部损伤(冈下肌部、小圆肌)13例.盂唇损伤的MRI表现为:三角外形消失,前关节囊扩大.肩袖损伤表现为:损伤部位高信号,连续性丧失. 结果 本组患者平均随访36个月(6～72个月),临床效果满意.美国加州洛杉矶大学关节功能评分标准(UCLA)评分:术前(15±3)分,术后(32±3)分(P＜0.01). 结论 创伤性肩关节盂唇损伤患者常同时合并肩袖损伤,临床上应予重视,避免遗漏诊断或耽误治疗.盂唇损伤范围与肩袖损伤部位存在对应关系,盂唇损伤范围越大,肩袖损伤越接近后侧.     

Rotator cuff tears: evaluation using double-contrast shoulder arthrography

To determine the accuracy of double-contrast arthrography in complete rotator cuff tears, we studied 805 patients thought to have a complete rotator cuff tear who had undergone double-contrast shoulder arthrography (DCSA) between 1978 and 1983. The results of this study indicate that DCSA is exquisitely sensitive and as accurate as the single-contrast examination. The site of disruption was directly visualized in 93% of cases, and the size of the defect and status of the torn tendon edges were reliably predicted. Such information may influence the surgeon in patient selection for operative repair as well as surgical approach.     

The coracoacromial arch: MR evaluation and correlation with rotator cuff pathology

The relative prevalence of various acromial shapes, appearance of the coracoacromial ligament and enthesophytes along the inferior aspect of the acromioclavicular joint in patients with and without rotator cuff tears were evaluated. Of 76 patients with clinical instability and impingement, 31 had a normal rotator cuff and 45 demonstrated a partial or full tear of the supraspinatus tendon at surgery. Results were compared with those from magnetic resonance (MR) scans of 57 asymptomatic volunteers. Of the 45 patients with a supraspinatus tear, 38% (17) had a flat acromial undersurface (type I), 40% (18) had a concave acromial undersurface (type II), 18% (8) had an anteriorly hooked acromion (type III), and 4% (2) had an inferiorly convex acromion (type IV). Among the 31 patients with a normal rotator cuff at surgery and the 57 asymptomatic volunteers, the respective prevalences of the type I acromion were 39% (12) and 44% (25), of type II 48% (15) and 35% (20), type III 3% (1) and 12% (7), and type IV 10% (3) and 9% (5). Shoulders with surgically proven rotator cuff tears showed a tendential association with a type III acromion (8/45) and statistically significant associations with a thickened coracoacromial ligament (17/45) and acromioclavicular enthesophytes (18/45). For the association between inferiorly directed acromioclavicular joint enthesophytes and rotator cuff tears, age appears to be a confounding factor. The type IV acromion, newly classified by this study, does not have a recognizable association with rotator cuff tears. Assessment of the osseous-ligamentous coracoacromial outlet by may prove helpful to the orthopedic surgeon in patients for whom surgical decompression is contemplated.