Biomedical subjects

Daryl C Osbahr

Publications and source records attributed to Daryl C Osbahr.

7 recordsLinked to original sources

PubMed2006

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.

Adult↗

PubMed2003

Analysis of rotator cuff muscles in adult human cadaveric specimens.

Management of irreparable massive rotator cuff tears remains a challenging and controversial problem. Defining glenohumeral force relations may allow for the development of treatment strategies based on biomechanical principles. Five fresh-frozen adult human cadaveric shoulder specimens were dissected to determine fiber length, mass, and lever arm of (a) the 3 bellies of the deltoid and (b) the rotator cuff muscles (supraspinatus, infraspinatus, teres minor, subscapularis). From these data, physiologic cross-sectional areas and moment relations were calculated. These relations provide evidence for a balanced axial force couple between the anterior and posterior rotator cuff. Demonstration of an axial force couple across the glenohumeral joint may have clinical significance for treatment of irreparable massive rotator cuff tears and may explain why many patients with full-thickness rotator cuff tears can regain acceptable shoulder function.

Aged↗

PubMed2002

The effect of continuous cryotherapy on glenohumeral joint and subacromial space temperatures in the postoperative shoulder.

PURPOSE: The objective of this investigation was to determine the effect of continuous cryotherapy on glenohumeral joint and subacromial space temperatures in the postoperative shoulder. TYPE OF STUDY: Prospective, randomized, and controlled clinical trial. METHODS: Twenty patients (10 cryotherapy, 10 controls) with a full-thickness rotator cuff repair were monitored with temperature sensors in the glenohumeral joint and subacromial space of the shoulder for 23 postoperative hours. Statistical analysis (P <.05) was performed using the Mann-Whitney rank-sum test. RESULTS: In comparing the cryotherapy and control groups, analysis of the glenohumeral joint and subacromial space temperatures revealed a statistical significance at 4, 8, and 23, and 4, 8, 16, and 20 postoperative hours, respectively. In addition, a trend toward a temperature-rising phase occurs from 4 to 12 hours and is followed by a trend toward a thermostatic phase from 12 to 23 hours during which temperatures remain relatively constant. The subacromial space was consistently cooler than the glenohumeral joint by an interval between 0.07 degrees C to 0.50 degrees C except at 23 hours postoperative where the glenohumeral joint was 0.05 degrees C cooler. CONCLUSIONS: Continuous cryotherapy causes a statistically significant reduction of both glenohumeral joint and subacromial space temperatures in the shoulder at variable times during the first 23 postoperative hours. Previous investigations have shown that minor elevations in intra-articular temperature can stimulate proteolytic enzyme activity, which has detrimental effects on articular cartilage. Previous research has also shown that cryotherapy is an effective nonpharmacological method of pain control. Yet the literature has assumed that the effects of cryotherapy are part of the basic analgesia mechanism because of a reduction in joint temperature. Our results affirm that reductions in glenohumeral joint and subacromial space temperatures in the postoperative shoulder do occur, leading to potential benefits of continuous cryotherapy as an effective mode of pain control in the postoperative care of patients.

Aged↗

PubMedDate not supplied

The cosmetic appearance of the biceps muscle after long-head tenotomy versus tenodesis.

PURPOSE: This study evaluates the cosmetic appearance of the biceps muscle after arthroscopic, intra-articular biceps tenotomy versus tenodesis by presenting subjective outcome results in patients with refractive bicipital pain. TYPE OF STUDY: Retrospective study evaluating clinical follow-up of patients with refractive and chronic bicipital pain. METHODS: Five consecutive years of patients receiving biceps tenotomy (80 patients; 40 males, 40 females; average age, 58 years) or tenodesis (80 patients; 51 males, 29 females; average age, 54 years) procedures were retrospectively followed-up by grading anterior shoulder pain, muscle spasms in the biceps, and cosmetic deformity of the biceps muscle. Statistics were done by chi(2) analysis. RESULTS: When assessing the follow-up questions, no statistical significance was found between the biceps tenotomy and biceps tenodesis groups. There was also no statistical significance when comparing the biceps tenotomy and biceps tenodesis groups when evaluating only the men, women, and men versus women with respect to the questions assessed. CONCLUSIONS: In the majority of patients in which a biceps tenotomy is performed, we note that the cosmetic appearance of the biceps muscle, the grade of muscle spasms of the biceps, and the level of anterior shoulder pain would present with little difference than if a tenodesis had been performed. Therefore, a biceps tenotomy may be a reasonable alternative to a biceps tenodesis in patients with refractive and chronic bicipital pain.

Adult↗

PubMedDate not supplied

An arthroscopic technique for confirming intra-articular subluxation of the long head of the biceps tendon: the ramp test.

The purpose of this technical note is to introduce the ramp test and explain this arthroscopic technique. The ramp test is used to test the integrity of the soft tissue restraint to intra-articular subluxation of the long head of the biceps tendon. Injury to the soft tissue restraint, the hidden lesion, has been proposed as occurring in conjunction with a full-thickness rotator cuff tear. Both cadaveric dissections and arthroscopic patient assessments were conducted to develop the ramp test. In this study, 17 patients also presented with refractory anterior shoulder pain and underwent arthroscopy to further characterize the ramp test. An abnormal examination result showed that the long head of the biceps tendon translated medially and inferiorly across the humeral head. In addition, this subgroup of 17 patients all had an abnormal ramp test but did not have a full-thickness rotator cuff tear. The ramp test is now applied to all arthroscopic procedures by the senior author, and we recommend its use for arthroscopic confirmation of intra-articular subluxation of the long head of the biceps tendon. Thus, we advocate that an abnormal ramp test result indicates pathology and warrants the surgical removal of the long head of the biceps tendon from the glenohumeral joint.

Arthroscopy↗

PubMedDate not supplied

Thermal capsulorraphy of bilateral glenohumeral joints in a pediatric patient with Ehlers-Danlos syndrome.

Ehlers-Danlos syndrome (EDS) is a heterogeneous collection of inherited connective tissue disorders characterized by hypermobility of the joints and hyperextensibility and fragility of the skin. For many patients, the hypermobile joints become problematic. To date, the mainstay of surgical treatment for EDS-related joint laxity has been open surgical capsulorraphy, which, although usually effective, confers significant morbidity to the patient. We present the case of a 9-year-old girl diagnosed with a variant of EDS and severely disabled from multidirectional instability of her shoulders and recurrent dislocations of her hips. After 1 year of nonoperative treatment (physical therapy, bracing, and activity restriction) failed, we performed a sequential arthroscopic thermal capsulorraphy of both shoulders. At a 2-year follow-up, the patient has no instability in the left shoulder and only occasional subluxations of the contralateral shoulder. We believe that thermal capsulorraphy is a viable addition to the shoulder surgeon's armamentarium in treating multidirectional instability in children with EDS.

Casts, Surgical↗

PubMedDate not supplied

Retroversion of the humerus in the throwing shoulder of college baseball pitchers.

BACKGROUND: Increased external rotation and decreased internal rotation have been noted to occur progressively in the throwing shoulder of baseball pitchers. HYPOTHESIS: Proximal remodeling of the humerus contributes to the rotational asymmetry between shoulders in pitchers. STUDY DESIGN: Descriptive anatomic study. METHODS: Both shoulders of 19 male college baseball pitchers were evaluated and retroversion of the humerus calculated by using the technique of Söderlund et al. Measurements were taken of passive glenohumeral external rotation at 0 degrees and 90 degrees of abduction and internal rotation at 90 degrees of abduction under a 3.5-kg load. Subjects completed a questionnaire on the amount and duration of overhead throwing performed during the ages 8 through 16 years. RESULTS: All of the subjects had greater external rotation at 0 degrees and 90 degrees of abduction, decreased internal rotation at 90 degrees of abduction, and greater retroversion of the humerus in their dominant compared with nondominant shoulders. A significant difference was found between dominant and nondominant external rotation at 0 degrees and 90 degrees of abduction, internal rotation at 90 degrees of abduction, and retroversion of the humerus. In the dominant arm, there was a significant correlation between retroversion of the humerus and external rotation at 0 degrees and 90 degrees of abduction. There was also a significant correlation between the side-to-side difference in retroversion of the humerus compared with the side-to-side difference in external rotation at 90 degrees of abduction. CONCLUSIONS: Rotational changes in the throwing shoulder are due to bony as well as soft tissue adaptations.

Adolescent↗