Biomedical subjects

Gerald R Williams

Publications and source records attributed to Gerald R Williams.

28 records · Page 2Linked to original sources

PubMed2003

Variation of biomechanical, structural, and compositional properties along the tendon to bone insertion site.

The tendon to bone insertion site is a complex transitional region that links two very different materials. The insertion site must transfer a complex loading environment effectively to prevent injury and provide proper joint function. In order to accomplish this load transfer effectively, the properties of the insertion site were hypothesized to vary along its length. The quasilinear viscoelastic (QLV) Model was used to determine biomechanical properties, polarized light analysis was used to quantitate collagen orientation (structure), and in situ hybridization was used to determine the expression of extracellular matrix genes (composition). All assays were performed at two insertion site locations: the tendon end of the insertion and the bony end of the insertion. Biomechanically, the apparent properties of peak strain, the coefficients (A and B) that describe the elastic component of the QLV model, and one of the coefficients (tau(1)) of the viscous component of the model were significantly higher, while another of the coefficients (C) of the viscous component was significantly lower at the tendon insertion compared to the bony insertion. The collagen was significantly more oriented at the tendon insertion compared to the bony insertion. Finally, collagen types II, IX, and X, and aggrecan were localized only to the bony insertion, while decorin and biglycan were localized only to the tendon insertion. Thus, the tendon to bony insertion site varies dramatically along its length in terms of its viscoelastic properties, collagen structure, and extracellular matrix composition.

Aggrecans↗

PubMed2003

Milwaukee shoulder: correlating possible etiologic variables.

The current study evaluated the relative correlation of apatite crystal-induced inflammation and rotator cuff deficiency in the development of cuff tear arthropathy. Thirty-seven patients with full thickness rotator cuff tears were evaluated by history, physical examination, and plain radiographs. Thirty patients had surgical intervention for their rotator cuff defects, and calipers were used intraoperatively to quantify the size of the tear in its largest diameter. The remaining seven patients were treated nonoperatively and the size of the tear was quantified using magnetic resonance imaging. Synovial fluid was obtained from all patients and analyzed for crystal content using an alizarin red stain. Synovial fluid also was analyzed for leukocyte count and differential, prostaglandin E, and matrix metalloproteinase. An unpaired Student's t test revealed that significantly higher levels of prostaglandin E were found in the synovial fluid of patients with apatite crystals, shown by alizarin red stain. Chi squared analysis showed that patients with elevated crystal levels were significantly more likely to have large rotator cuff tears or glenohumeral arthritis. Establishing such relations potentially can elucidate the etiology and treatment of this complex disorder.(2) (2)

Arthritis↗

PubMed2002

Case challenges in shoulder surgery: what would you do?

The management of complex shoulder issues was discussed in an interactive case presentation session. Patient scenarios discussed included reoperation of a rotator cuff repair with a subscapularis tear; uncemented hemiarthroplasty presenting with pain and osteolysis; severe osteoarthritis with all nonoperative options exhausted; rheumatoid arthritis with pain and diminished function; and significant pain, limited motion, and weakness in an active patient.

Arthritis, Rheumatoid↗

PubMed2002

Management of periprosthetic fractures: the shoulder.

The incidence of periprosthetic fracture during or after shoulder arthroplasty is 1% to 3% of all shoulder arthroplasties. The frequency with which this injury occurs may be increasing, however. Contemporary implants have been designed specifically for uncemented use and often have larger proximal bodies. During insertion, attempts are made to achieve a tight, line-line fit. Consequently the risk for periprosthetic fracture may be higher than estimated.

Arthroplasty, Replacement↗

PubMed2002

Magnetic resonance imaging analysis of coracoid morphology and its relation to rotator cuff tears.

The purpose of this study was to define the magnetic resonance imaging (MRI) anatomy of the subcoracoid space and to determine its relation to rotator cuff tears. Routine clinical MRI sequences of 100 shoulders were reviewed, and standardized measurements of the subcoracoid space were taken and compared with previously published computed tomographic (CT) data. MRI and CT values were very similar. There were no significant differences between the coracoid morphology of patients with normal findings and patients with varying degrees of rotator cuff disease involving the supraspinatus tendon. The excellent agreement between MRI and CT measurements indicates that different investigators may use either imaging modality to obtain reproducible results. The role of coracoid anatomy in the development of lesions of the subscapularis tendon and the long head of the biceps remains to be defined.

Adult↗

PubMedDate not supplied

Supraspinatus tendon composition remains altered long after tendon detachment.

Most rotator cuff surgery is performed on chronic tears, but changes in the composition of chronically torn tendons remain poorly understood. In this study we surgically created supraspinatus tears in the rat and analyzed the composition of the tendon over time using immunohistochemistry. We found that collagen types I and XII were greatly increased initially after injury and then decreased with time. Collagen type III was detected and persisted in the scar for months. Decorin and biglycan were increased initially and then decreased, although decorin remained elevated from normal for months after injury. Aggrecan and collagen type II were detected in small amounts after detachment, which was associated with the expression of sulfated glycosaminoglycans. These alterations were similar to those seen in human studies. As the quality of the tendon is an important factor in repair, these findings may partially explain why chronic tears heal differently than acute tears.

Animals↗

PubMedDate not supplied

Total shoulder arthroplasty: glenoid component design.

Although Charles Neer's original glenoid component underwent several modifications, the all-polyethylene, keeled component with a radius of curvature that conformed to the humeral radius of curvature and that was implanted with cement became the glenoid implant of choice. Neer reported approximately a 30% incidence of radiolucent lines; however, only 2 of 615 glenoids were revised for loosening. Other surgeons have reported radiolucent lines in up to 90% of glenoid components and have correlated symptoms with increasing radiolucencies. This has led to the development of alternative glenoid components for unconstrained total shoulder arthroplasty. Variations in component design include component shape, articular conformity, method of fixation, and material composition. The purposes of this presentation are to review the performance of the original Neer design, as well as other more recent glenoid designs, to identify factors that may influence the performance of glenoid components, and to provide a rationale for future changes in glenoid component design.

Arthroplasty, Replacement↗

PubMedDate not supplied

Surgical treatment of os acromiale with and without associated rotator cuff tears.

Nineteen consecutive patients treated surgically for meso-os acromiale and subacromial pathology were reviewed retrospectively, with a mean length of follow-up of 40 months (range, 24-94 months). Of the patients, 11 (58%) were treated with acromioplasty in the presence of a stable os acromiale; 8 patients (42%) underwent open reduction-internal fixation for an unstable and painful os fragment. Of the 19 patients, 8 (42%) with an os acromiale had an associated full-thickness rotator cuff tear. Overall, only 10 of 19 patients (53%) achieved a satisfactory result. All 8 patients (100%) treated with open reduction-internal fixation achieved union of the os fragment, although only 3 (37.5%) achieved a satisfactory result. Of the 11 patients who underwent acromioplasty, only 7 (64%) achieved a satisfactory result. The outcome of surgical management of symptomatic meso-os acromiale with concomitant rotator cuff pathology was satisfactory in 4 of 8 patients in our study group. The rate of satisfactory results was similar in patients with (50%) and without (55%) associated rotator cuff tears. When we analyzed our results to exclude workers' compensation patients, 80% achieved satisfactory results (compared with only 22% in our workers' compensation group).

Acromion↗

PubMedDate not supplied

Non-prosthetic management of grade IV osteochondral lesions of the glenohumeral joint.

Osteochondral lesions of the glenohumeral joint in early stages and in younger patients are an important problem and present a challenge during clinical decision making. Although prosthetic arthroplasty remains the gold standard for treatment in later stages of the disease, alternatives are desirable in the early stages and in young patients. The purposes of this study are to evaluate the results of arthroscopic debridement and capsular release in patients with grade IV osteochondral lesions of the glenohumeral joint and to determine the factors associated with their success. Sixty-one patients with grade IV osteochondral lesions of the glenohumeral articular surfaces were treated with arthroscopic debridement, with or without arthroscopic capsular release. Standardized data collection was performed at the initial office visit and at the time of final follow-up. Overall outcome was analyzed with regard to patients' self-assessment of pain, function, improvement, satisfaction, and duration of pain relief. Forty-five of the patients had a minimum follow-up of 2 years. Time-to-event analysis was used to evaluate the duration of pain relief. The mean patient satisfaction score (0 = not satisfied; 10 = completely satisfied) improved from 0.67 preoperatively to 6.28 at final follow-up (P <.0001), with 87% of patients indicating that they would have the surgery again. Although workers' compensation patients obtained inferior results, significant improvement in pain and function was obtained in 88% of all patients (P <.0001). Most patients noted the onset of pain relief within 5 weeks of surgery and obtained a duration of pain relief of 28 months or greater (P <.05). The addition of concomitant procedures, such as acromioplasty, distal clavicle resection, labral debridement, or labral repair, did not have a negative impact on the functional results after arthroscopic debridement and capsular release. In well-selected patients with grade IV osteochondral lesions of the glenohumeral joint, significant improvements in pain relief and function follow arthroscopic debridement of the glenohumeral joint. Arthroscopic capsular release can be added in patients with a loss of passive arcs of shoulder motion. Osteochondral lesions greater than 2 cm(2) appear to be associated with return of pain and failure of this procedure.

Adult↗

PubMedDate not supplied

Iliotibial band reconstruction for treatment of glenohumeral instability associated with irreparable capsular deficiency.

The surgical management of patients with recurrent anterior instability after failed surgery can be complicated by the loss of capsular tissue and, in some cases, irreparable tears of the subscapularis tendon. We describe a new surgical technique for reconstruction of the capsular ligaments using the iliotibial band (ITB) to reconstruct deficient capsular tissues, and we report the results of 7 patients. All patients had prior surgery, with a mean of 2.2 procedures, and recurrent instability as the primary indication for their index and revision surgeries. After ITB reconstruction, the patients demonstrated significant improvement in their American Shoulder and Elbow Surgeons (ASES) score (P =.0004), and no patient had any persistent symptoms of instability. Physiologic range of motion and function were maintained. We would recommend our method of ITB reconstruction for patients with instability and capsular deficiency after failed surgery and believe that this procedure has advantages over those previously described. Capsular deficiency and persistent instability after prior surgery can occur after prior open or arthroscopic surgery. Capsular deficiency has been described after thermal capsulorrhaphy and is thought to represent excessive thermal injury and tissue necrosis. After open capsulorrhaphy, capsular deficiency can be associated with subscapularis tendon deficiency.(4,6-8,12,13) Capsular deficiency occurring after either open or arthroscopic surgery presents a difficult surgical challenge. The purpose of this case series is to evaluate our experience in the surgical management of recurrent glenohumeral instability after surgery initially performed for treatment of glenohumeral instability that failed and is associated with irreparable tears of the subscapularis and capsular deficiency. The primary objectives of this study are to describe the surgical technique for capsular reconstruction with ITB and to report the clinical results in 7 patients.

Adult↗