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ABSTRACT: In a shoulder requiring arthroplasty, if the glenoid is flat or biconcave, the surgeon can restore the desired glenoid stability by using a glenoid prosthesis with a known surface geometry or by modifying the surface of the glenoid to a geometry that provides the desired glenoid stability. This study tested the hypotheses that (1) the stability provided by the glenoid is reduced by the removal of the articular cartilage; (2) the stability contributed by the glenoid is compromised by loss of its articular cartilage, and this lost stability can be restored by spherical reaming along the glenoid centerline; and (3) the stability of a reamed glenoid is comparable with that of a native glenoid and with that of a polyethylene glenoid with similar surface geometry; and (4) the glenoid stability can be predicted from the glenoid surface geometry.
The stability provided by the glenoid in a given direction can be characterized by the maximal angle that the humeral joint reaction force can make with the glenoid centerline before the humeral head dislocates; this quantity is defined as the balance stability angle in the specified direction. The balance stability angles were both calculated and measured in eight different directions for an unused polyethylene glenoid component and eleven cadaveric glenoids in four different states: (1) native without the capsule or the rotator cuff, (2) denuded of cartilage and labrum, (3) after reaming the glenoid surface around the glenoid centerline with use of a spherical reamer with a radius of 25 mm, and (4) after reaming around the glenoid centerline with use of a spherical reamer with a radius of 22.5 mm.
The calculated and measured balance stability angles for each direction in each glenoid were strongly correlated. Denuding the glenoids of the articular cartilage reduced the glenoid contribution to stability, especially in the posterior direction. Reaming the glenoid restored the stability to values comparable with those of the normal glenoid. For example, the average calculated balance stability angle (and standard deviation) in the posterior direction for all eleven glenoids was 24 degrees for the native glenoids, 14 degrees for the denuded glenoids, 25 degrees for the glenoids reamed to a radius of 25 mm, and 33 degrees for the glenoids reamed to a radius of 22.5 mm. The values for the glenoids reamed to 25 mm (25 degrees ) were similar to those of a polyethylene glenoid of the same radius of curvature. For glenoids reamed to 22.5 mm, the average difference between the actual balance stability angle and that predicted from the glenoid geometry was 3.4 degrees +/- 2.4 degrees.
The glenoid contribution to shoulder stability was decreased by the removal of cartilage and labrum and was restored by spherical reaming to a level similar to resurfacing the glenoid with a polyethylene component.
The Journal of Bone and Joint Surgery 10/2004; 86-A(9):2022-9. · 3.27 Impact Factor
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ABSTRACT: Glenohumeral arthritis has many different etiologies, including osteo-arthritis, secondary degenerative joint disease, rheumatoid arthritis,avascular necrosis, cuff tear arthropathy, and capsulorrhaphy arthropathy. Each of these diagnoses may have different underlying pathoanatomy and pathomechanics. The treating physician must recognize how these characteristics impair shoulder function so that the prescribed course of treatment addresses the root causes of shoulder dysfunction. The patient's age. level of physical activity, and comorbidities should be taken into account, and the intended management should be weighed against how these factors may interfere with treatment efficacy over the long-term. The goal of treatment is to restore comfort, motion, strength, and stability to the shoulder in a safe and reliable manner. Conservative treatments should aim to optimize shoulder flexibility, maintain muscle function, and reduce inflammation. Activity modification is crucial but often unreasonable to the active patient. Temporary surgical approaches include arthroscopic debridement and synovectomy. These approaches may be appropriate for a younger patient with some remaining joint space and a functional rotator cuff. Definitive surgical treatment typically involves either a proximal humerus replace mentor a total shoulder replacement. The decision to resurface the glenoid should be based on the patient's age, diagnosis, available bone stock, and physical demands. The surgeon must be familiar with the options provided by the given implant system so that the proper balance of motion and stability can be restored with a close approximation of the native anatomy. Inexperienced hands, good-to-excellent results can be achieved in greater than 90% of properly selected patients. Glenoid component failure is one of the most common complications of shoulder arthroplasty, highlighting the need to select carefully patients in whom glenoid resurfacing is warranted.
Physical Medicine and Rehabilitation Clinics of North America 06/2004; 15(2):447-74. · 1.40 Impact Factor
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ABSTRACT: Rotator cuff tears are among the most common conditions of the shoulder. One of the major difficulties in studying patients with rotator cuff tears is that the clinical expression of these tears varies widely and different practices may have substantially different patient populations. The goals of the present prospective multipractice study were to use patient self-assessment questionnaires (1) to identify some of the characteristics of patients with rotator cuff tears, other than the size of the cuff tear, that are correlated with shoulder function, and (2) to determine whether there are significant differences in these characteristics among patients from the practices of different surgeons.
Ten surgeons enrolled a total of 333 patients with a full-thickness tear of the supraspinatus tendon into this prospective study. Each patient completed self-assessment questionnaires that included items regarding demographic characteristics, prior treatment, medical and social comorbidities, general health status, and shoulder function.
As expected, patients who had an infraspinatus tendon tear as well as a supraspinatus tendon tear had significantly worse ability to use the arm overhead compared with those who had a supraspinatus tear alone (p < 0.005). However, shoulder function and health status were correlated with patient characteristics other than the size of the rotator cuff tear. The number of shoulder functions that were performable was correlated with the subscales of the Short Form-36 and was inversely associated with medical and social comorbidities. The patients from the ten different surgeon practices showed significant differences in almost every parameter, including age, gender, method of tear documentation, tear size, prior treatment, medical and social comorbidities, general health status, and shoulder function.
Clinical studies on the natural history of rotator cuff tears and the effectiveness of treatment must control for a wide range of variables, many of which do not pertain directly to the shoulder. Patients from the practices of different surgeons cannot be assumed to be similar with respect to these variables. Patient self-assessment questionnaires appear to offer a practical method of uniform assessment across different practices.
The Journal of Bone and Joint Surgery 05/2003; 85-A(4):690-6. · 3.27 Impact Factor
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ABSTRACT: Both shoulder surgeons and patients who are considering total shoulder arthroplasty are interested in the anticipated improvement in shoulder comfort and function after the procedure. The purpose of the present study was to characterize shoulder-specific functional gains in relation to preoperative shoulder function and to present this information in a way that can be easily communicated to patients who are considering this surgery.
We analyzed the preoperative and follow-up shoulder function in patients managed with total shoulder arthroplasty for the treatment of primary glenohumeral osteoarthritis. Functional self-assessments were available for 102 (80%) of 128 shoulders after thirty to sixty months of follow-up. Outcome was assessed with respect to the change in the number of shoulder functions that were performable, the change in shoulder function as a percentage of the preoperative functional deficit, and the change in the ability to perform specific shoulder functions.
The average number of shoulder functions that were performable improved from four of twelve preoperatively to nine of twelve postoperatively (p < 0.01). Function improved in ninety-six shoulders (94%). The number of functions that were performable at the time of follow-up was positively associated with preoperative shoulder function (p < 0.05): the better the preoperative function, the better the follow-up function. The improvement in function was greatest for shoulders with less preoperative function (p < 0.01). On the average, patients regained approximately two-thirds of the functions that had been absent preoperatively. Significant improvement was noted in eleven of the twelve shoulder functions that were examined (p < 0.01). The chance of regaining a function that had been absent before surgery was 73%, whereas the chance of losing a function that had been present before surgery was 6%. Older men tended to have greater functional improvement than younger men.
Total shoulder arthroplasty for the treatment of primary glenohumeral osteoarthritis significantly improves shoulder function. Postoperative function is related to preoperative function. The improvement that was observed in this clinical series can be conveyed to patients most simply by stating that, after surgery, shoulders typically regained approximately two-thirds of the functions that had been absent preoperatively.
The Journal of Bone and Joint Surgery 08/2002; 84-A(8):1349-53. · 3.27 Impact Factor
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ABSTRACT: The purpose of this study is to define the self-assessed deficits in function and general health perceived by a large cohort of patients with common shoulder diagnoses. For a 10-year period, all new shoulder patients presenting to the senior author were characterized by diagnosis, age, gender, and self-assessed shoulder function and general health status. This report concerns the 2674 patients having 1 of the 16 most prevalent diagnoses. The deficits in shoulder function and health status were correlated with diagnosis, age, and gender, as well as with each other. Patient self-assessment provided a standardized method for collecting data on shoulder function and health status. These assessments revealed substantial deficits; for example, 81% of patients were unable to sleep on the affected side, and 71% were unable to wash the back of the opposite shoulder. The magnitude of these deficits correlated significantly with gender and diagnosis but not with age.
Journal of Shoulder and Elbow Surgery 15(1):30-9. · 2.75 Impact Factor
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Current Problems in Diagnostic Radiology 32(3):127-34.
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ABSTRACT: This study compared self-assessed deficits in comfort, function, and health status before and after total shoulder arthroplasty for 4 different diagnoses: degenerative joint disease (DJD), secondary DJD (2 degrees DJD), rheumatoid arthritis (RA), and capsulorrhaphy arthropathy (CA). Deficits were assessed by the Simple Shoulder Test and Short Form 36 (SF-36) questionnaires. There was a significant difference among diagnoses for preoperative and postoperative functional deficits. The profiles of improvement within the categories of comfort, motion, strength, and function were different for each diagnosis. Patients with DJD and CA were most improved in the category of motion, whereas those with 2 degrees DJD and RA were most improved in the category of comfort. There was also a statistically significant difference in 5 of the 8 domains of the preoperative SF-36 among diagnoses. Factors associated with each diagnosis play a significant role in determining the magnitude of preoperative deficits and postoperative improvement in shoulder function.
Journal of Shoulder and Elbow Surgery 14(6):575-84. · 2.75 Impact Factor
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ABSTRACT: Previous work suggests that the labrum helps center the humeral head. We hypothesized that detachment of the labrum alone would shift the head from its centered position toward the detachment, and repair would restore its centered position. Five young shoulders were used, and glenoids were potted with the articular surfaces oriented horizontally. Unconstrained humeral heads were subjected to 30-N compressive loads and no displacing force. Using a technique with 10-micrometer resolution, we quantified head and glenoid positions before and after anteroinferior labral detachment and after three types of repair. Detachment was associated with humeral head shift toward the labral lesion in all specimens, averaging 0.74 mm (range, 0.51-1.00 mm) (P <.005). Repair to the lip restored the labrum's centering effect variably. Repair with suture anchors on the glenoid face over-reduced the humeral head, shifting it posterosuperiorly by a mean of 3.47 mm (range, 0.71-6.7 mm) (P <.05). The labrum is important for humeral head centering, even without displacing loads.
Journal of Shoulder and Elbow Surgery 12(1):53-8. · 2.75 Impact Factor
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ABSTRACT: The objective of this study was to characterize self-assessed functional deficits before and after total shoulder arthroplasty (TSA) in a consecutive series of 24 patients treated for capsulorrhaphy arthropathy. Deficits were determined by use of the Simple Shoulder Test. The effects of age, type of original stabilization surgery, duration of time since the initial repair, and pattern of glenoid erosion were analyzed. Deficits were significantly reduced from 8.5 to 4 of 12 SST items after TSA (P = .003). Items related to motion and function had the largest effect on improvement. Age did not affect results. There was a trend toward greater improvement in patients whose original stabilization was less than 20 years previously (P = .06) and in those with concentric glenoid erosion (P = .06). A prior Bristow procedure was associated with the least improvement. Overall, TSA was an effective treatment for capsulorrhaphy arthropathy at midterm follow-up. Restoring range of motion appears to have the largest impact on improvement in function.
Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.] 16(3 Suppl):S19-26. · 1.93 Impact Factor
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ABSTRACT: We tested the hypothesis that the stabilizing function of the labrum can be enhanced by inflating it with blood. In 6 fresh cadaveric glenoids, the anteroinferior stability provided by the glenoid was quantitated by measuring the maximal angle between the glenoid centerline and the direction of the force applied via a ball in the glenoid before the ball dislocated from the glenoid. This stability angle was measured for each of 4 different applied loads. These measurements were repeated after the anteroinferior labrum was augmented by the injection of fresh blood. Injection augmentation of the labrum significantly increased the measured stability angles in 5 of 6 specimens. The 1 outlier had a partial labral tear. The mean increase in stability for all 6 glenoids ranged from 19% to 30% for the different test loads. Labral injection with blood may be a useful adjunct in the surgical management of glenohumeral instability.
Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.] 15(6):651-8. · 1.93 Impact Factor
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ABSTRACT: Failure of the glenoid component is the most common indication for late revision of a total shoulder arthroplasty (TSA). This is the first study to characterize the deterioration in patient self-assessment of shoulder function occurring with glenoid component failure at times remote from the index surgery. Of 115 total shoulders, 11 had revision by the original surgeon for isolated glenoid loosening. Simple Shoulder Test scores averaged 4.4 before TSA, rose to a mean of 11.3 after surgery, and fell to a mean of 4.6 before revision for glenoid loosening performed at a mean of 7 years after TSA. All shoulders showed a drop of at least 3 points between the peak Simple Shoulder Test score and the prerevision Simple Shoulder Test score. Periodic self-assessment of shoulder function may offer a method of screening patients for the possibility of late glenoid component failure.
Journal of Shoulder and Elbow Surgery 14(4):368-74. · 2.75 Impact Factor
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ABSTRACT: Practice is the repetition of an action to improve its quality. The value of the practice effect is recognized in sports, music, and surgery. The number of times a surgical procedure is performed may have a bearing on how well it is done. We investigated the relative frequency with which hip, knee, and shoulder replacements are performed by individual surgeons. The 1998 database of the Center for Medical Consumers in New York State revealed that over 40% of hip or knee replacement surgeons performed 10 or more replacements. In contrast, only 10 shoulder replacement surgeons (3%) performed 10 or more such procedures; 75% performed only one or two. The distribution of shoulder replacement among surgeons was statistically different than for hip or knee replacement (P <.0001). These findings suggest the need for robust educational programs to minimize the potential adverse effects of low surgeon volume for the patients undergoing these procedures.
Journal of Shoulder and Elbow Surgery 12(2):164-9. · 2.75 Impact Factor
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ABSTRACT: Failure of shoulder arthroplasty is often defined as a complication or the need for revision, but it may also be viewed as a result that does not meet the expectations of the patient. To enhance our understanding of failed shoulder arthroplasties, we identified the characteristics common to a series of 139 consecutive patients who came to our shoulder consultation service because of dissatisfaction with the result of their shoulder arthroplasty. Primary osteoarthritis (28%) and proximal humeral fractures (26%) were the most common indications for the initial arthroplasty. Seventy-three shoulders (fifty-two percent) had at least one surgery before arthroplasty was performed. Seventy-four percent of the shoulders were stiff, 35% were unstable, and in the total shoulders, 59% of the glenoids were loose. Components were substantially malpositioned in 23%. Forty-two percent of shoulders with a failed hemiarthroplasty had substantial glenoid erosion, and 43% of shoulders that had undergone a hemiarthroplasty for fracture had nonunion of the tuberosities. Patients demonstrated impaired shoulder function; on average, they could perform only 2 of 12 shoulder functions. The rate of revision underestimated the rate of failure, as 23% of arthroplasties did not undergo revision. The challenge of achieving patient satisfaction after arthroplasty may be greater than previously recognized. Many of these unsatisfactory shoulder arthroplasties did not meet the criteria for failure used in previously published series. These observations suggest that greater attention to achieving proper component position, postoperative motion, and in fracture cases, fixation of the tuberosities may lead to increased patient satisfaction after shoulder arthroplasty.
Journal of Shoulder and Elbow Surgery 11(5):431-41. · 2.75 Impact Factor
