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Biomedical subjects

A Lee Osterman

Publications and source records attributed to A Lee Osterman.

8 recordsLinked to original sources
PubMed2005

The effect of ulnar shortening on lunate and triquetrum motion--a cadaveric study.

BACKGROUND: Ulnar shortening osteotomy is a widely used procedure for a number of pathologic conditions. However, there is little biomechanical data on its effect on the surrounding soft tissue structures. Therefore, the objective of this study was to determine the effects of progressive ulnar shortening on the distal radioulnar joint and the proximal carpal bones. METHODS: The kinematics and strain between the ulnar styloid, lunate, and triquetrum were evaluated with varying supination and pronation forces. Six fresh-frozen cadaveric upper extremity specimens were tested after progressive ulnar shortening using a custom jig. Biomechanical measurements including strain and translation were made by evaluating the change in position of the digitizing markers on the carpal bones, radius and ulna. FINDINGS: There were significant changes in marker positions with respect to intact specimens for each amount of shortening at the ulnar styloid (P<0.001), the lunate (P<0.001), and triquetrum (P<0.001). With progressive ulnar shortening, the strain data demonstrated that there was no significant change in lunato-triquetral strain, but demonstrated a significant increase in both ulno-triquetral and ulno-lunato strain (P<0.04). INTERPRETATION: Progressive ulnar shortening increases ulno-triquetral and ulno-lunato strains with an ensuing reduction in motion between the carpal bones.

Cadaver↗
PubMed2005

Arthroscopic techniques for wrist arthritis (radial styloidectomy and proximal pole hamate excisions).

Over the last 2 decades, arthroscopy has assumed a greater role in the treatment of disorders of the wrist. The arthroscopic treatment of radioscaphoid arthritis and ulnar hamate impaction provides the benefits of being minimally invasive, with less morbidity, earlier motion, less recovery time, early return to work, and greater patient acceptance. Both procedures are performed easily using standard arthroscopic techniques without any significant learning curve.Long-term studies need to be performed to determine the exact clinical sequelae of excision of the proximal pole of the hamate, specifically on the biomechanics of the triquetrohamate articulation.

Arthritis↗
PubMed2003

Preiser's disease: identification of two patterns.

PURPOSE: A large series of patients with Preiser's disease was reviewed to compare 2 potentially different categories of this disorder: complete versus partial vascular impairment of the scaphoid bone as determined by magnetic resonance imaging (MRI). METHODS: Nineteen patients with Preiser's disease were identified retrospectively from 2 institutions. Using MRI criteria, 2 disease patterns were identified: diffuse necrosis and/or ischemia of the scaphoid (type 1 disease, 11 cases) and segmental vascular impairment of the scaphoid (type 2 disease, 8 cases). Risk factors for osteonecrosis, treatment methods, and serial radiographs were reviewed in all cases. Sixteen patients were examined for the purpose of this study at an average follow-up of 25 months. RESULTS: MRI signal changes of necrosis and/or ischemia involved 100% of the scaphoid in type 1 cases and on average approximately 42% in type 2 cases (range, 33% to 66%). In type 1 cases, regardless of the treatment used, the scaphoid typically fragmented and collapsed. In type 2 cases, scaphoid architecture was altered minimally after similar treatment methods. A history of wrist trauma was significantly more common in type 2 cases, and the results of treatment were generally better in this group of patients (mean Mayo modified wrist scores, 86 vs 58 points). CONCLUSIONS: This study supports the concept of 2 patterns of scaphoid involvement in Preiser's disease. Type 1 cases are characterized by MRI signal changes of necrosis and/or ischemia involving the entire scaphoid bone. Patients in this group have a propensity for scaphoid deterioration. Type 2 cases have MRI signal changes involving only part of the scaphoid. These patients commonly report a history of wrist trauma, show fewer tendencies toward scaphoid fragmentation, and may have a more favorable clinical outcome.

Adult↗
PubMed2003

Internal derangement of the wrist: indirect MR arthrography versus unenhanced MR imaging.

PURPOSE: To compare indirect magnetic resonance (MR) arthrography with unenhanced MR imaging of the wrist for evaluation of the central disk of the triangular fibrocartilage complex (TFCC) and the scapholunate and lunotriquetral interosseous ligaments. MATERIALS AND METHODS: Eighty-six wrists were evaluated at MR imaging (41 indirect MR arthrography and 45 unenhanced MR imaging examinations). Three musculoskeletal radiologists independently evaluated the central disk of the TFCC and scapholunate and lunotriquetral ligaments and compared the results with those of wrist arthroscopy. Sensitivity and specificity were calculated for each of the readers, and the means were obtained. Sensitivities and specificities were compared with the Student t test. RESULTS: Thirty-three tears of the central disk of the TFCC and 13 scapholunate and 18 lunotriquetral ligament tears were identified at arthroscopy. Sensitivities and specificities were 54%-73% and 83%-91%, respectively, in the evaluation of the central disk of the TFCC, with no significant difference between indirect MR arthrography (P =.666) and unenhanced MR imaging (P =.559). Sensitivities and specificities in the evaluation of the scapholunate ligament were 38%-69% and 75%-99%, respectively, with a significant improvement in sensitivity at indirect MR arthrography (P =.017) and no significant difference in specificity (P =.876). Sensitivities in the evaluation of the lunotriquetral ligament were poor, 0%-22%, though the specificities were 88%-99%, with no significant difference between indirect MR arthrography and unenhanced MR imaging (P =.592 and P =.354, respectively, for sensitivity and specificity. CONCLUSION: Indirect MR arthrography significantly improves sensitivity in the evaluation of the scapholunate ligament when compared with unenhanced MR imaging of the wrist but does not significantly improve the ability to evaluate the central disk of the TFCC or the lunotriquetral ligament.

Adult↗
PubMed2002

Nonoperative carpal tunnel syndrome treatment.

Many factors influence the development of CTS; therefore, nonoperative treatment should not be limited to only one intervention. Nonoperative treatment is most effective in the early stages, prior to irreparable damage to the nerve. Early intervention combined with a comprehensive treatment plan can help improve effectiveness of treatment during this phase. We do not endorse any one particular conservative treatment/program as the solution for CTS, but our purpose is to explore potential options. Further study is needed to determine the most beneficial and cost-effective treatments.

Anti-Inflammatory Agents↗
PubMed2002

Kinematic analysis of the distal radioulnar joint after a simulated progressive ulnar-sided wrist injury.

A kinematic analysis of a progressive, ulnar-sided wrist injury was performed using a cadaver model to study the static and dynamic stabilizers of the distal radioulnar joint with a 3-dimensional motion tracking system. Anatomically based loads were applied to achieve pronation and supination and then the specimens were evaluated after serial transection of the triangular fibrocartilage, the extensor carpi ulnaris sheath, and the ulnocarpal ligaments. Statistically significant increases in translation of the radius relative to the ulna occurred with sectioning of both the triangular fibrocartilage proper and the extensor carpi ulnaris tendon sheath. No significant change in position of the forearm could be appreciated with subsequent sectioning of the ulnocarpal ligaments. Our observations support the idea that the ulnocarpal ligaments do not need to be surgically reconstructed when there are serious injuries to the triangular fibrocartilage complex.

Biomechanical Phenomena↗
PubMed2002

Limitations of MR imaging in the diagnosis of peripheral tears of the triangular fibrocartilage of the wrist.

OBJECTIVE: The treatment of peripheral tears of the triangular fibrocartilage complex is radically different from the more typical central, degenerative tears. To our knowledge, no reports in the imaging literature specifically evaluate tears of the ulnar attachment of the triangular fibrocartilage complex. We evaluated the accuracy of MR imaging in these patients. MATERIALS AND METHODS: Eighty-six MR imaging examinations of the wrist (41 indirect MR arthrograms and 45 unenhanced MR images) were evaluated: 20 wrists with surgically confirmed peripheral triangular fibrocartilage complex tears and 66 wrists with surgically documented normal ulnar attachment. These cases were evaluated by three experienced musculoskeletal radiologists, who were unaware of the surgical findings, to assess the presence of peripheral triangular fibrocartilage complex tears or fluid signal at the ulnar attachment of the triangular fibrocartilage complex. RESULTS: The sensitivity for evaluation of the peripheral triangular fibrocartilage complex tear was 17%, with a specificity of 79% and an accuracy of 64%. High signal intensity at the ulnar insertion of the triangular fibrocartilage complex as a marker for tear showed a sensitivity of 42%, a specificity of 63%, and an accuracy of 55%. Weighted kappa values revealed only fair agreement among the three observers. CONCLUSION: MR imaging does not adequately reveal the peripheral attachment of the triangular fibrocartilage complex.

Adolescent↗