MEMS switch integrated radio frequency coils and arrays for magnetic resonance imaging.

Surface coils are widely used in magnetic resonance imaging and spectroscopy. While smaller diameter coils produce higher signal to noise ratio (SNR) closer to the coil, imaging larger fields of view or greater distance into the sample requires a larger overall size array or, in the case of a channel count limited system, larger diameter coils. In this work, we consider reconfiguring the geometry of coils and coil arrays such that the same coil or coil array may be used in multiple field of view imaging. A custom designed microelectromechanical systems switch, compatible with magnetic resonance imaging, is used to switch in/out conductive sections and components to reconfigure coils. The switch does not degrade the SNR and can be opened/closed in 10 µs, leading to rapid reconfiguration. Results from a single coil, configurable between small/large configurations, and a two-coil phased array, configurable between spine/torso modes, are presented.

Low-dose CT imaging of radio-opaque markers for assessing human rotator cuff repair: accuracy, repeatability and the effect of arm position.

Previous studies have used radiostereometric analysis (RSA) to assess the integrity and mechanical properties of repaired tendons and ligament grafts. A conceptually similar approach is to use CT imaging to measure the 3D position and distance between implanted markers. The purpose of this study was to quantify the accuracy and repeatability of measuring the position and distance between metallic markers placed in the rotator cuff using low-dose CT imaging. We also investigated the effect of repeated or variable positions of the arm on position and distance measures. Six human patients had undergone rotator cuff repair and placement of tantalum beads in the rotator cuff at least one year prior to participating in this study. On a single day each patient underwent nine low-dose CT scans in seven unique arm positions. CT scans were analyzed to assess bias, precision and RMS error of the measurement technique. The effect of repeated or variable positions of the arm on the 3D position of the beads and the distance between these beads and suture anchors in the humeral head were also assessed. Results showed the CT imaging method is accurate and repeatable to within 0.7 mm. Further, measures of bead position and anchor-to-bead distance are influenced by arm position and location of the bead within the rotator cuff. Beads located in the posterior rotator cuff moved medially as much as 20 mm in abduction or external rotation. When clinically relevant CT arm positions such as the hand on umbilicus or at side were repeated, bead position varied less than 4 mm in any anatomic direction and anchor-to-bead distance varied +2.8 to -1.6 mm (RMS 1.3 mm). We conclude that a range of ± 3 mm is a conservative estimate of the uncertainty in anchor-to-bead distance for patients repeatedly scanned in clinically-relevant arm positions.

Porcine small intestine submucosa as a flexor tendon graft.

An attractive strategy for tendon tissue engineering is the use of natural extracellular matrices as scaffold materials. One matrix that has been shown to promote healing and regeneration of neotissue in various applications is porcine-derived small intestinal submucosa. It was the objective of this study to investigate small intestinal submucosa for intrasynovial flexor tendon grafting in a canine model. We hypothesized that at 6 weeks small intestinal submucosa grafts would undergo host cell infiltration, neovascularization, and replacement by host neotendon. We also hypothesized that small intestinal submucosa grafts would be incorporated by the host without extensive adhesions to surrounding tissues and therefore maintain normal digit function. An intrasynovial tendon autograft was used as a gold standard. At 6 weeks the intrasynovial tendon autografts remained viable, contained normal numbers of cells along their length, and had minimal peritendinous adhesions. Four of six autografts had normal function as determined by rotation of the distal interphalangeal joint. Also at 6 weeks, the small intestinal submucosa grafts had host cell infiltration, neovascularization, and wavy, oriented tissue. However, ubiquitous adhesions together with impaired function in all cases suggest that small intestinal submucosa grafts in the configuration used are not suitable as full-length intrasynovial grafts in this tendon and animal model.

A finite element model of the shoulder: application to the comparison of normal and osteoarthritic joints.

OBJECTIVE: The objective of the present study was to develop a numerical model of the shoulder able to quantify the influence of the shape of the humeral head on the stress distribution in the scapula. The subsequent objective was to apply the model to the comparison of the biomechanics of a normal shoulder (free of pathologies) and an osteoarthritic shoulder presenting primary degenerative disease that changes its bone shape. DESIGN: Since the stability of the glenohumeral joint is mainly provided by soft tissues, the model includes the major rotator cuff muscles in addition to the bones. BACKGROUND: No existing numerical model of the shoulder is able to determine the modification of the stress distribution in the scapula due to a change of the shape of the humeral head or to a modification of the glenoid contact shape and orientation. METHODS: The finite element method was used. The model includes the three-dimensional computed tomography-reconstructed bone geometry and three-dimensional rotator cuff muscles. Large sliding contacts between the reconstructed muscles and the bone surfaces, which provide the joint stability, were considered. A non-homogenous constitutive law was used for the bone as well as non-linear hyperelastic laws for the muscles and for the cartilage. Muscles were considered as passive structures. Internal and external rotations of the shoulders were achieved by a displacement of the muscle active during the specific rotation (subscapularis for internal and infrapinatus for external rotation). RESULTS: The numerical model proposed is able to describe the biomechanics of the shoulder during rotations. The comparison of normal vs. osteoarthritic joints showed a posterior subluxation of the humeral head during external rotation for the osteoarthritic shoulder but no subluxation for the normal shoulder. This leads to important von Mises stress in the posterior part of the glenoid region of the pathologic shoulder while the stress distribution in the normal shoulder is fairly homogeneous. CONCLUSION: This study shows that the posterior subluxation observed in clinical situations for osteoarthritic shoulders may also be cause by the altered geometry of the pathological shoulder and not only by a rigidification of the subscapularis muscle as often postulated. This result is only possible with a model including the soft tissues provided stability of the shoulder. RELEVANCE: One possible cause of the glenoid loosening is the eccentric loading of the glenoid component due to the translation of the humeral head. The proposed model would be a useful tool for designing new shapes for a humeral head prosthesis that optimizes the glenoid loading, the bone stress around the implant, and the bone/implant micromotions in a way that limits the risks of loosening.

Arthroscopic capsular release for the treatment of refractory postoperative or post-fracture shoulder stiffness.

BACKGROUND: Arthroscopic capsular release is used to treat idiopathic adhesive capsulitis (frozen shoulder) that is refractory to nonoperative treatment or manipulation under anesthesia. The role of arthroscopic capsular release in the treatment of frozen shoulder after shoulder surgery or fracture is less clearly understood. The purposes of this study were to define the outcome of arthroscopic capsular release in the management of frozen shoulder after surgery or fracture and to compare these results with those of arthroscopic capsular release in the treatment of idiopathic frozen shoulder. METHODS: We evaluated the results of arthroscopic capsular release in three different groups of patients with shoulder contracture refractory to nonoperative management and manipulation under anesthesia. The three groups consisted of patients who had an idiopathic frozen shoulder, shoulder stiffness after surgery, or shoulder stiffness after fracture. We evaluated pain, function, patient satisfaction, and range of motion in all three groups before and after the study treatment. RESULTS: At a mean of twenty months (range, twelve to forty-six months) after the operation, fifty patients were available for assessment of function and range of motion of the involved shoulder. At the time of follow-up, each group had a significant improvement in the scores for pain, patient satisfaction, and functional activity as well as in the overall outcome score (p < 0.01). Comparison of the scores among the different groups revealed that all had a similar degree of improvement in range of motion of the involved shoulder, but patients with postoperative frozen shoulder had significantly (p < 0.05) lower scores for pain (p < 0.03), patient satisfaction (p < 0.004), and functional activity (p < 0.002) than did those with idiopathic or post-fracture frozen shoulder. CONCLUSIONS: Arthroscopic capsular release was as effective for improving range of motion in patients with postoperative contracture of the shoulder as it was in patients with idiopathic and post-fracture contracture. However, there was less improvement in the subjective scores for pain, function, and patient satisfaction in the postoperative group.

Instability after prosthetic arthroplasty of the shoulder.

Instability of the shoulder is a common complication after prosthetic arthroplasty and accounts for approximately 4% to 5% of case series with mixed preoperative diagnoses. Several anatomic abnormalities and risk factors are associated with this problem. The direction of instability often is associated with the more common types of structural abnormalities.

The effect of articular malposition after total shoulder arthroplasty on glenohumeral translations, range of motion, and subacromial impingement.

The articular surface of the normal humeral head has a variable posterior and medial offset with respect to the central axis of the humeral shaft. Recreation of the normal humeral head shaft offset is postulated to be an important consideration during shoulder arthroplasty. However, the effect of humeral head malposition is unknown. The purpose of this study was to determine the effect of articular malposition after total shoulder arthroplasty on glenohumeral translation, range of motion, and subacromial impingement. Twenty-one human cadavers were dissected and tested with the use of an active or passive shoulder model. Range of motion and translation were recorded by means of an electromagnetic tracking device. The experiment was performed in 2 phases. For kinematics study, 11 cadaver shoulders were positioned both passively and actively from maximum internal rotation to maximum external rotation at 90 degrees of total elevation in the scapular plane. Three rotator cuff and 3 deltoid muscle lines of action were simulated for active joint positioning. Passive joint positioning was accomplished with the use of a torque wrench and a nominal centering force. The testing protocol was used for the natural joint as well as for 9 prosthetic head locations: centered and 2- and 4-mm offsets in the anterior, posterior, inferior, and superior directions. Repeated-measures analysis of variance was used to test for significant differences in the range of motion and translation between active and passive positioning of the natural joint as well as all prosthetic head positions. (2) For impingement study, 10 cadaver shoulders were used in a passive model, loading the tendons of the rotator cuff with a 30-N centering force. The humerus was passively rotated from maximum internal rotation (1500 Nmm) to maximum external rotation (1500 Nmm) by means of a continuous-recording digital torque wrench. Trials were performed with the use of centered, 4-, 6-, and 8-mm offset heads in the anterior, posterior, superior, and inferior positions before and after removal of the acromion and coracoacromial ligament. The relation between change in mean peak torque (with and without acromion), passive range of motion, and humeral head offset was analyzed by means of repeated-measures analysis of variance. In the kinematics study, total range of motion and all humeral translations were greater with passive joint positioning than with active positioning (P =.01) except for total superior-inferior translation and superior-inferior translation in external rotation. Anterior to posterior humeral head offset was associated with statistically significant changes in total range of motion (P =.02), range of internal rotation (P =.02), range of external rotation (P =.0001), and total anterior-posterior translation (P =.01). Superior to inferior humeral head offset resulted in statistically significant changes in total range of motion (P =.02), range of internal rotation (P =.0001), anterior-posterior translation during external rotation (P =.01), and total superior-inferior translation (P =.03). In the impingement study, there was a significant increase in torque from centered to 4-mm inferior offset (P =.006), 6-mm inferior offset (P <.001), and 8-mm inferior offset (P <.001). There was no significant increase in torque with superior, anterior, and posterior offsets. Glenohumeral motion significantly decreased from 129 degrees for centered head to 119 degrees for 8-mm superior (P =.002), 119 degrees for 8-mm anterior (P =.014), 118 degrees for 8-mm inferior (P <.001), and 114 degrees for 8-mm posterior (P =.001). Humeral articular malposition of 4 mm or less during prosthetic arthroplasty of the glenohumeral joint may lead to small alterations in humeral translations and range of motion. Inferior malposition of greater than 4 mm can lead to increased subacromial contact; offset of 8 mm in any direction results in significant decreases in passive range of motion. Therefore if subacromial contact is to be minimized and glenohumeral motion maximized after shoulder replacement, anatomic reconstruction of the humeral head-humeral shaft offset to within 4 mm is desirable.

The floating shoulder: a biomechanical basis for classification and management.

BACKGROUND: The floating shoulder (ipsilateral fractures of the clavicular shaft and the scapular neck) is thought to be an unstable injury pattern requiring operative stabilization in most instances. This recommendation has been made with little biomechanical data to support it. The purpose of this study was to determine the osseous and ligamentous contributions to the stability of experimentally created scapular neck fractures in a cadaver model. METHODS: Standardized scapular neck fractures were made in twelve fresh-frozen human cadaveric shoulders. Each specimen was mounted in a specially designed testing apparatus and secured to a standard materials testing device. In group 1 (six shoulders), resistance to medial displacement was determined following sequential creation of an ipsilateral clavicular fracture, coracoacromial ligament disruption, and acromioclavicular capsular disruption. In group 2 (six shoulders), resistance to medial displacement was determined following sequential sectioning of the coracoacromial and coracoclavicular ligaments. RESULTS: The average measured force for all specimens (groups 1 and 2) after scapular neck fracture was 183 +/- 3.3 N (range, 166 to 203 N). The addition of a clavicular fracture (group 1) resulted in an average measured force of 128 +/- 10.5 N (range, 83 to 153 N), which corresponds to only a 30% loss of stability. Subsequent sectioning of the coracoacromial and acromioclavicular capsular ligaments yielded an average force of 126 +/- 9.1 N (range, 114 to 144 N), a 31% loss of stability, and 0 N, a complete loss of stability, respectively. Sectioning of the coracoacromial and coracoclavicular ligaments after scapular neck fracture (group 2) resulted in an average force of 103 +/- 8.4 N (range, 89 to 118 N), a 44% loss of stability, and 0 N, a complete loss of stability, respectively. CONCLUSIONS: Ipsilateral fractures of the scapular neck and the clavicular shaft do not produce a floating shoulder without additional disruption of the coracoacromial and acromioclavicular capsular ligaments. These and other unstable combined injury patterns are likely to be accompanied by substantial medial displacement of the glenoid fragment.

Prospective longitudinal analysis of postoperative shoulder function : a ten-year follow-up study of full-thickness rotator cuff tears.

BACKGROUND: Rotator cuff repair is associated with good short or mid-term results, but to date there have been no long-term functional outcome studies demonstrating durability of results over time. In most long-term studies, the results have been compared with those of historical controls or with those of other, short-term follow-up studies. The purpose of the present prospective study was to evaluate short and long-term shoulder function after surgical repair in a single population of patients in order to follow changes over time. METHODS: Thirty-three patients underwent surgery, performed by one surgeon, for the treatment of a chronic, symptomatic, full-thickness rotator cuff defect. Data were obtained from questionnaires and physical examinations preoperatively, at two years, and at ten years. Identical standardized pain and function questionnaires were used and clinical evaluation was performed in a consistent fashion at all time-periods. The activity level, Constant score, level of disability, shoulder function score, and patient's subjective rating of the outcome were determined at the time of the final follow-up and compared with the same parameters at the two-year follow-up examination in order to determine if early results change with time. RESULTS: At the ten-year follow-up examination, there was no change in the raw Constant score determined at the two-year examination. When the Constant score was normalized for expected age-related changes, the percentage of patients who had a satisfactory result at ten years was even greater than the percentage at two years. Activity level decreased significantly over the time-period (p = 0.005). At the final follow-up examination, twelve patients worked at the same occupation as they had when the two-year examination was performed, two worked at a less strenuous occupation, and the remaining patients were retired. Only two patients retired because of problems related to the shoulder. The level of disability decreased over the study period, and there was a small improvement in the patients' self-assessment shoulder function score. The patients' subjective assessment of the outcome remained unchanged. CONCLUSIONS: The results of open rotator cuff repair for chronic tears do not deteriorate with time (ten years). The level of disability decreases, presumably because of a concurrent decrease in the activity level and in the demand on the shoulder as the patient ages. It is important to consider age-related changes when assessing the final outcome.

Suprascapular neuropathy. Variability in the diagnosis, treatment, and outcome.

The functional outcome of operative and nonoperative treatment of suprascapular neuropathy was compared to determine the preferred method of treatment for each etiology of nerve injury. The predictive value of preoperative electromyography also was studied. Fifty-three patients were evaluated at least 1 year (average, 28 months) from the time of operative (n = 36) or nonoperative (n = 17) treatment. A modified American Shoulder and Elbow Surgeons self-assessment score was obtained at presentation and at final followup. Electromyography data were obtained at initial presentation. Minimal electromyographic changes associated with denervation were associated with a limited response to treatment, especially in patients with nerve compression secondary to spinoglenoid notch cysts. Pretreatment electromyographic findings, therefore, were predictive of treatment response. Overall, operative and nonoperative treatment of these suprascapular nerve injuries resulted in significant functional improvement, but the results varied depending on the etiology of the injury. Spinoglenoid notch cysts responded significantly better to operative treatment, with the results for open surgery being the same as the results for arthroscopic decompression. In addition, compressive lesions attributable to suprascapular notch entrapment had the best improvement with surgical decompression. Traumatic lesions, including traction and direct closed injuries, had an equal response to operative and nonoperative treatment. Overuse injuries did not improve with operative treatment. Viral neuritis improved with nonoperative treatment and never was treated with surgery. Overall, traumatic injuries resulted in significantly worse final outcomes than any other etiologic processes. In the nonoperative group, neuropathy secondary to spinoglenoid cysts resulted in significantly worse function. The outcome of treatment is dependent on the severity and etiology of the nerve injury, and the method of treatment.

Displaced three- and four-part proximal humerus fractures: evaluation and management.

Three- and four-part fractures are the most severe injuries in the spectrum of fractures of the proximal humerus. Despite the shortcomings of the currently available imaging techniques, fracture displacement remains an important principle in guiding management. As a result, increasing emphasis has been placed on the use of Neer's criteria in intraoperative decision making. Patients with four-part fractures with valgus impaction of the head fragment should be treated with limited open reduction and minimal internal fixation, as the blood supply to the humeral head is better preserved than with other fracture patterns and the potential for osteonecrosis is less. In the case of displaced three- and four-part fractures, the physiologic age and bone quality also help guide treatment selection. In young patients with good bone quality, attempts to preserve the humeral head by meticulous handling of soft tissues and the use of low-profile implants to secure fracture fragments is recommended. Vertical fixation alone with Rush rods in patients with poor bone quality and in those with four-part fractures is no longer considered adequate and should not be used. For selected patients with three-part fractures and satisfactory bone quality, fixation with Ender rods and tension-band wiring may be appropriate. Elderly patients and those with poor bone quality have a greater risk of loss of reduction after open reduction and internal fixation, and the current consensus is that early hemiarthroplasty is the appropriate treatment. Late reconstruction necessitated by malunion and soft-tissue contracture is technically difficult, and the outcome is less favorable. The outcome of treatment of three- and four-part fractures is dependent on the surgeon's ability to analyze the fracture pattern and execute appropriate techniques to restore anatomy and function. The use of cement for prosthetic fixation and rigorous attention to tuberosity stabilization and anatomic reduction are two factors that will optimize outcome. Adequate pain relief after hemiarthroplasty has been consistently demonstrated, but return of motion and function is less predictable.

Management of surgical neck nonunions.

A surgical neck nonunion is a seriously debilitating complication of a proximal humerus fracture. Patients have virtually no functional use of their shoulders and experience pain. Successful treatment is reliable in relief of pain and potentially can restore function. The diagnosis is not difficult, however, a CT scan may be necessary to identify tuberosity or head-splitting fractures. Successful treatment for these nonunions is difficult but gratifying because the percent improvement is immense.

A standardized method for assessment of elbow function. Research Committee, American Shoulder and Elbow Surgeons.

The American Shoulder and Elbow Surgeons have adopted a standardized form for assessment of the elbow. This form was developed by the Research Committee of the American Shoulder and Elbow Surgeons and subsequently adopted by the membership. The patient self-evaluation section contains visual analog scales for pain and a series of questions relating to function of the extremity. The responses to the questions are scored on a 4-point ordinal scale. The physician assessment section has 4 parts: motion, stability, strength, and physical findings. It is hoped that adoption of this method of data collection will stimulate multicenter studies and improve communication between professionals who assess and treat patients with elbow disorders.

The acromioclavicular capsule as a restraint to posterior translation of the clavicle: a biomechanical analysis.

Excessive posterior translation of the residual clavicle after distal clavicle resection can be associated with significant postoperative pain. Although the acromioclavicular capsule has been identified as the primary restraint to translation of the clavicle along this axis, the individual contributions of the anterior, posterior, superior, and inferior components of the capsular ligament have not been established. The purpose of this study was to define the relative roles of the individual acromioclavicular capsular ligaments in preventing posterior translation of the distal clavicle in normal acromioclavicular joints in a human cadaver model. Six fresh-frozen human cadaveric acromioclavicular joints were mounted on a specially designed apparatus which, when attached to a standard servohydraulic materials testing device, allowed translation of the distal clavicle along the anteroposterior axis of the acromioclavicular joint (i.e., parallel to the articular surface). Resistance to posterior displacement was measured for standardized displacements in the normal specimens and after serial sectioning of each of the acromioclavicular ligaments was performed. Sectioning of the anterior and inferior capsular ligaments had no significant effect on posterior translation at the 5% significance level. However, sectioning of the superior and posterior ligaments had statistically significant effects (P < .05). These capsular structures contributed 56% +/- 23% (+/- SEM) and 25% +/- 16%, respectively, of the force required to achieve a given posterior displacement. To avoid excessive posterior translation of the clavicle after distal clavicle excision, surgical techniques that spare the posterior and superior acromioclavicular capsular ligaments should be used.

Periprosthetic fractures of the humerus and scapula: management and prevention.

The management of humerus fractures is complicated by the presence of a prosthesis. Vigilance in addressing the mechanisms and predisposing factors for periprosthetic fracture may prevent their occurrence. In the event of a periprosthetic fracture, attention to prosthetic stability, fracture location and stability, and bone quality will help guide treatment decisions. Treatment should be commensurate with the goals of fracture stability, early rehabilitation, and maintaining a well-functioning prosthesis.

Anatomy of the scapulothoracic articulation.

Four fresh frozen human cadavers (eight extremities) consisting of the head, neck, thorax, and entire upper extremities were used for dissection of the scapulothoracic articulation. In each specimen, the spinal accessory nerve, all relevant muscle insertions, and bursae were identified and measured. The structures of the scapulothoracic articulation can be divided into superficial, intermediate, and deep layers. The superficial layer consists of the trapezius, latissimus dorsi, and an inconsistent bursa between the inferior angle of the scapula and the latissimus dorsi. The intermediate layer consists of the levator scapulae, rhomboid minor and major, spinal accessory nerve, and scapulotrapezial bursa located between the superomedial scapula and the overlying trapezius. In all specimens, the spinal accessory nerve traveled intimately along the wall of the scapulotrapezial bursa, an average of 2.7 cm lateral to the superomedial angle of the scapula. The deep layer consists of the serratus anterior, subscapularis, and two bursae: one between the serratus and the thorax, the scapulothoracic bursa; and one between the subscapularis and the serratus, the subscapularis bursa.

Partial-thickness tears of the rotator cuff: evaluation and management.

The approach to management of a partial-thickness rotator cuff tear is best made with the understanding that this is not a singular condition. Rather, partial tears represent the common outcome of a variety of insults to the rotator cuff. Degenerative changes due to aging, anatomic impingement, and trauma may all be etiologic agents. Overhead athletes may develop tears due to repetitive microtrauma or internal impingement. Outlet radiographs and magnetic resonance imaging are recommended for routine preoperative evaluation. A nonoperative treatment program for rotator cuff strengthening and stretching is appropriate as initial treatment; modification of activities and anti-inflammatory medication are often used as well. Operative management may be considered when nonoperative treatment fails. Arthroscopic evaluation is required to determine the true extent of the cuff lesion. Arthroscopic subacromial decompression is recommended when outlet impingement is present. Rotator cuff debridement or formal cuff repair is dependent on the size of the cuff defect and the age and activity level of the patient. The importance of recognizing the different causes of partial-thickness rotator cuff tears is emphasized in this review of pathogenesis, clinical diagnosis, imaging, and treatment.

Operative treatment of malunion of a fracture of the proximal aspect of the humerus.

We retrospectively reviewed the medical records, operative reports, and preoperative and postoperative radiographs of thirty-nine patients who had been managed operatively for malunion of a fracture of the proximal aspect of the humerus. The malunions were categorized according to the presence of osseous abnormalities, including malposition of the greater or lesser tuberosity (type I; twenty-eight patients), incongruity of the articular surface (type II; twenty-six patients), and malalignment of the articular segment (type III; sixteen patients). Soft-tissue abnormalities, such as soft-tissue contracture, a tear of the rotator cuff, and impingement, were also recorded. At an average of forty-four months (range, twelve to fifty-three months) postoperatively, the patients were assessed for pain relief, the range of motion of the shoulder, and the ability to perform activities of daily living. The result was satisfactory for twenty-seven patients (69 per cent) and unsatisfactory for the remaining twelve (31 per cent) at the latest follow-up evaluation. Of the twenty-seven patients who had a satisfactory result, twenty-six (96 per cent) had had complete operative correction of all osseous and soft-tissue abnormalities. Of the twelve patients who had an unsatisfactory result, four had had complete operative correction of these abnormalities (p < 0.0001). Twenty-six patients (67 per cent) had incongruity of the glenohumeral joint at the time of presentation. Twenty-three of these patients had the incongruity corrected with prosthetic arthroplasty (twenty-two) or arthrodesis of the glenohumeral joint (one); the result was satisfactory for seventeen (74 per cent). In contrast, the result was unsatisfactory for all three patients in whom the incongruity had not been corrected at the time of the operation (p = 0.01). Eleven patients had malposition of the greater or lesser tuberosity but a congruent joint surface preoperatively. Ten patients in this group were managed with either osteotomy of the tuberosity or acromioplasty, and nine of them had a satisfactory result at the latest follow-up evaluation. The result was unsatisfactory for one patient who was managed with only correction of a soft-tissue contracture (that is, no treatment of the malposition) (p = 0.05). Both osseous and soft-tissue abnormalities were identified as the cause of pain and stiffness in patients who had malunion of a fracture of the proximal aspect of the humerus. We concluded that operative management of these patients is successful only if all osseous and soft-tissue abnormalities are corrected at the time of the operation.