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Biomedical subjects

Edward G McFarland

Publications and source records attributed to Edward G McFarland.

At least 19 recordsLinked to original sources

Shoulder arthroplasty versus hip and knee arthroplasties: a comparison of outcomes.

Although outcomes of shoulder, hip, and knee arthroplasties have been well-described, there have been no studies directly comparing the outcomes of these procedures as treatments for osteoarthritis. We compared the inpatient mortality, complications, length of stay, and total charges of patients who had shoulder arthroplasty for osteoarthritis with those of patients who had hip and knee arthroplasties for osteoarthritis. A review of the Maryland Health Services Cost Review Commission discharge database identified 994 shoulder arthroplasties, 15,414 hip arthroplasties, and 34,471 knee arthroplasties performed for osteoarthritis from 1994 to 2001. There were no in-hospital deaths after shoulder arthroplasty, whereas 27 (0.18%) and 54 (0.16%) deaths occurred after hip and knee arthroplasties, respectively. Compared with patients who had hip or knee arthroplasties, patients who had shoulder arthroplasties had, on average, a lower complication rate, a shorter length of stay, and fewer total charges. The latter had 1/2 as many in-hospital complications, were 1/6 as likely to have a length of stay 6 days or greater, and were 1/10 as likely to be charged more than $15,000. We believe shoulder arthroplasty is as safe as the more commonly performed major joint arthroplasties.

Aged↗

Laxity testing of the shoulder: a review.

Laxity testing is an important part of the examination of any joint. In the shoulder, it presents unique challenges because of the complexity of the interactions of the glenohumeral and scapulothoracic joints. Many practitioners believe that laxity testing of the shoulder is difficult, and they are unclear about its role in evaluation of patients. The objectives of the various laxity and instability tests differ, but the clinical signs of such tests can provide helpful information about joint stability. This article summarizes the principles of shoulder laxity testing, reviews techniques for measuring shoulder laxity, and evaluates the clinical usefulness of the shoulder laxity tests. Shoulder laxity evaluation can be a valuable element of the shoulder examination in patients with shoulder pain and instability.

Biomechanical Phenomena↗

The reverse shoulder prosthesis: A review of imaging features and complications.

BACKGROUND: The reverse shoulder prosthesis is a prosthesis that has been in clinical use in Europe since 1985 and was approved for use in the United States in 2004. This unique prosthesis has a baseplate attached to the glenoid, which holds a spherical component, while the humeral component includes a polyethylene insert that is flat. This design is the "reverse" configuration of that seen with a conventional arthroplasty, in which the spherical component is part of the humeral component. The indications for the reverse prosthesis are: (1) painful arthritis associated with irreparable rotator cuff tears (cuff tear arthropathy), (2) failed hemiarthroplasty with irreparable rotator cuff tears, (3) pseudoparalysis due to massive, irreparable rotator cuff tears, (4) some reconstructions after tumor resection, and (5) some fractures of the shoulder not repairable or reconstructable with other techniques. This prosthesis can produce a significant reduction in pain and some improvement in function for most of the indications mentioned. However, the unique configuration and the challenge of its insertion can result in a high incidence of a wide variety of unusual complications. Some of these complications, such as dislocation of the components, are similar to conventional shoulder replacement. Other complications, such as notching of the scapula and acromial stress fractures, are unique to this prosthesis. CONCLUSION: The configuration of the reverse prosthesis, its normal radiographic appearance and potential complications associated with its use are reviewed.

Arthroplasty, Replacement↗

Suture anchors and tacks for shoulder surgery, part II: the prevention and treatment of complications.

The use of suture anchors and tacks around the shoulder requires a thorough knowledge of the proper use of the devices and how to insert them. Although typically not technically demanding, suture anchors and tacks can present unique and frustrating challenges to the patient and the surgeon. These challenges can occur whether the procedure is performed via an open or arthroscopic approach, but knowledge of the potential challenges may optimize the surgical result and prevent complications. Complications can be categorized as technique-related or device-related issues (mechanical or biologic failure). Technique-related complications include problems with the delivery systems, anchor malpositioning, and suture management issues, such as knots not sliding. Device-related complications include implant fracture, migration secondary to poor fixation, synovitis from implant degradation, and osteolysis. This review describes the prevention of these and other complications, addresses the indications or need for intervention, and suggests potential solutions when intervention is indicated.

Humans↗

Posterior dislocation in a voluntary subluxator: a case report.

PURPOSE: Posterior instability of the shoulder is an uncommon occurrence. Its etiology has been classified as traumatic or atraumatic and its type as voluntary (individual can subluxate the shoulder posteriorly) or involuntary. Typically, patients with posterior voluntary instability do not have a history of trauma, can be treated successfully with physical therapy; and undergo surgery if the instability becomes symptomatic or develops an involuntary component. We present a patient with voluntary posterior subluxation who developed a symptomatic posterior instability after a traumatic event. PATIENT PRESENTATION: This patient was unable to return to his preinjury function despite nonoperative interventions, including rehabilitation, and required operative treatment of his posterior labrum lesion. This patient had a rare combination of voluntary, atraumatic instability that coexisted with traumatic posterior shoulder instability. CONCLUSION: This case emphasizes the importance of recognizing this constellation of instability patterns and documents that traumatic posterior instability, even in the presence of preexisting voluntary posterior subluxations, may require operative intervention in young, active individuals.

Adolescent↗

Clinical assessment of three common tests for traumatic anterior shoulder instability.

BACKGROUND: Although traumatic anterior shoulder instability is common, the usefulness of various physical examination tests as tools for the diagnosis of this condition has been studied infrequently. We hypothesized that (1) such tests would be specific but not sensitive for this condition, (2) the usefulness of the anterior drawer test would be limited because of pain during the test, and (3) an anterior drawer test would be a useful adjunct for making the diagnosis if it reproduced the instability symptoms. METHODS: Between 2000 and 2004, 363 patients underwent a physical examination followed by shoulder arthroscopy. Forty-six patients with traumatic anterior shoulder instability that had been noted arthroscopically or documented radiographically after the trauma were included in our study group, and the remaining patients served as controls. The clinical usefulness of three tests (anterior apprehension, relocation, and anterior drawer tests) performed during the physical examination to make a diagnosis of traumatic anterior instability then was evaluated with statistical methods to assess their sensitivity, specificity, and likelihood ratios. RESULTS: If demonstration (or relief) of apprehension was used as the diagnostic criterion for a positive test, the sensitivity, specificity, and likelihood ratio were 72%, 96%, and 20.2, respectively, for the apprehension test and 81%, 92%, and 10.4, respectively, for the relocation test. If pain (or relief of pain) was used as the diagnostic criterion for a positive test, the values for the sensitivity, specificity, and likelihood ratio of both tests were lower. The anterior drawer test could be performed successfully in the physician's office for 87% of the patients. If reproduction of instability symptoms was used as the criterion for a positive anterior drawer test, the sensitivity, specificity, and likelihood ratio values of that test were 53%, 85%, and 3.6, respectively. CONCLUSIONS: The three physical examination tests for traumatic anterior shoulder instability are specific but not sensitive. Apprehension is a better criterion than pain for a positive apprehension or relocation test. The anterior drawer test (when pain does not prevent it from being performed) is helpful for diagnosing traumatic anterior instability. LEVEL OF EVIDENCE: Diagnostic Level I. See Instructions to Authors for a complete description of levels of evidence.

Adolescent↗

Clinical evaluation of impingement: what to do and what works.

Theories about the etiologies of anterior and lateral shoulder pain have changed greatly since "impingement disease" was first described. It is thought that such pain may be caused by contact between the rotator cuff and the acromion and coracoacromial ligament, but the exact pathophysiology of rotator cuff disease remains unclear. The shoulder is notoriously difficult to examine because of the variability of the physical findings in patients with rotator cuff disease. New concepts of impingement, such as coracoid impingement and internal impingement, have been advanced. Although no test is definitive for all causes of anterior and lateral shoulder pain, as the pathophysiology of these conditions becomes better understood the ability to evaluate them clinically also improves.

Diagnosis, Differential↗

Revision surgery for failed thermal capsulorrhaphy.

BACKGROUND: With the failure of thermal capsulorrhaphy for shoulder instability, there have been concerns with capsular thinning and capsular necrosis affecting revision surgery. PURPOSE: To report the findings at revision surgery for failed thermal capsulorrhaphy and to evaluate the technical effects on subsequent revision capsular plication. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Fourteen patients underwent arthroscopic evaluation and open reconstruction for a failed thermal capsulorrhaphy. The cause of the failure, the quality of the capsule, and the ability to suture the capsule were recorded. The patients were evaluated at follow-up for failure, which was defined as recurrent subluxations or dislocations. RESULTS: The origin of the instability was traumatic (n = 6) or atraumatic (n = 8). At revision surgery in the traumatic group, 4 patients sustained failure of the Bankart repair with capsular laxity, and the others experienced capsular laxity alone. In the atraumatic group, all patients experienced capsular laxity as the cause of failure. Of the 14 patients, the capsule quality was judged to be thin in 5 patients and ablated in 1 patient. A glenoid-based capsular shift could be accomplished in all 14 patients. At follow-up (mean, 35.4 months; range, 22 to 48 months), 1 patient underwent revision surgery and 1 patient had a subluxation, resulting in a failure rate of 14%. CONCLUSIONS: Recurrent capsular laxity after failed thermal capsular shrinkage is common and frequently associated with capsular thinning. In most instances, the capsule quality does not appear to technically affect the revision procedure.

Adolescent↗

Suture anchors and tacks for shoulder surgery, part 1: biology and biomechanics.

The development and successful clinical application of suture anchors and tacks have revolutionized the surgeon's ability to secure soft tissues to bone via open or arthroscopic surgical techniques. When used carefully and with proper technique, these devices provide viable options for the repair and reconstruction of many intra-articular and extra-articular abnormalities in the shoulder, including rotator cuff tears, shoulder instability, and biceps lesions that require labrum repair or biceps tendon tenodesis. Like many technologies, however, the successful application of these devices requires an understanding of the biology and biomechanics that affect their use in the shoulder as well as knowledge of the factors that can affect subsequent clinical outcomes, including complications.

Absorbable Implants↗

Diagnostic accuracy of clinical tests for the different degrees of subacromial impingement syndrome.

BACKGROUND: Several tests for making the diagnosis of rotator cuff disease have been described, but their utility for diagnosing bursitis alone, partial-thickness rotator cuff tears, and full-thickness rotator cuff tears has not been studied. The hypothesis of this study was that the degree of severity of rotator cuff disease affects the diagnostic values of the commonly used clinical tests. METHODS: Eight physical examination tests (the Neer impingement sign, Hawkins-Kennedy impingement sign, painful arc sign, supraspinatus muscle strength test, Speed test, cross-body adduction test, drop-arm sign, and infraspinatus muscle strength test) were evaluated to determine their diagnostic values, including likelihood ratios and post-test probabilities, for three degrees of severity in rotator cuff disease: bursitis, partial-thickness rotator cuff tears, and full-thickness rotator cuff tears. A forward stepwise logistic regression analysis was used to determine the best combination of clinical tests for predicting the various grades of impingement syndrome. RESULTS: The sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of the eight tests varied considerably. The combination of the Hawkins-Kennedy impingement sign, the painful arc sign, and the infraspinatus muscle test yielded the best post-test probability (95%) for any degree of impingement syndrome. The combination of the painful arc sign, drop-arm sign, and infraspinatus muscle test produced the best post-test probability (91%) for full-thickness rotator cuff tears. CONCLUSIONS: The severity of the impingement syndrome affects the diagnostic values of the commonly used clinical tests. The variable accuracy of these tests should be taken into consideration when evaluating patients with symptoms of rotator cuff disease.

Diagnostic Techniques and Procedures↗

Total knee arthroplasty in Ehlers-Danlos syndrome.

The Ehlers-Danlos syndromes (EDS) are a rare group of connective tissue disorders characterized by severe joint hypermobility and instability. Ten patients with 12 primary knee arthroplasties were identified. Average age at time of surgery was 43.3 years, with follow-up data acquired at an average of 65 months after surgery. Primary indications for surgery were tibiofemoral or patellar instability (n = 8) and arthritis (n = 4). Knee Society Functional scores averaged 29.6 before surgery and 51.3 at time of interview (P<.005). Knee Society Knee scores at time of follow-up evaluation averaged 70. Tibiofemoral and patella stability were significantly improved. Arthroplasty appears to be an effective option for knee arthritis and instability in EDS patients, although results and satisfaction are lower than that reported for conventional arthroplasty indications.

Adult↗