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Biomedical subjects

L D Field

Publications and source records attributed to L D Field.

At least 19 recordsLinked to original sources

Solution- and solid-phase synthesis of components for tethered bilayer membranes.

The synthesis of the novel compound PhCH(2)SS(C(24)H(44)N(4)O(10))(C(20)H(41)) (5) for the preparation of tethered bilayer membranes is described. The compound is the all-amide analogue of the previously reported ester-containing membrane-forming material PhCH(2)SS(C(24)H(40)O(14))(C(20)H(41)) (1). The advanced intermediate (C(20)H(41)) C(16)H(28)N(3)O(8) (17) was prepared from the same starting materials using both solution-phase (13% yield) and solid-phase (81% yield) techniques. Monolayers on gold derived from 5 have been analyzed by ellipsometry and FTIR. The monolayers exhibit thicknesses similar to monolayers derived from 1 and possess H-bonded amide functionality.

Journal Article↗

Anterior superior instability with rotator cuff tearing: SLAC lesion.

Anterosuperior instability of the shoulder may occur from a variety of pathologic lesions. We describe a specific entity, the SLAC (superior labrum, anterior cuff) lesion that involves an association of anterior-superior labral tear with a partial supraspinatus tear. We retrospectively isolated a group of 40 patients with this lesion. The presenting complaints, physical examination findings, surgical findings, and results were isolated. Overhead activities were the most common etiology; load and shift instability testing and whipple rotator cuff testing were the most common physical examination findings. Surgical repair was successful in 37 of the 40 patients. The SLAC lesion is a definable clinical entity with predictable history, examination, surgical pathology, and satisfactory results from surgery.

Adolescent↗

Osteochondritis dissecans of the elbow.

Osteochondritis dissecans of the elbow remains a difficult problem to manage in the young athlete. Though the etiology is unclear, a definite association between overuse with repetitive microtraumatic insult and OCD has been established. Early detection and appropriate treatment can provide the best chance for preventing an unfavorable outcome. In many cases, conservative treatment regimens will provide complete resolution of symptoms, return of function, and full recovery, including return to sports participation. Surgical indications should be recognized, however, and surgical management carried out when warranted. Most authors treat unstable lesions primarily by excision of the fragment, accompanied by drilling or burring of the base of the lesion. Symptoms usually improve significantly, but approximately half of all patients will continue to experience chronic pain or limitation of elbow motion, highlighting the significance and severity of OCD of the elbow.

Adolescent↗

Posterolateral rotatory instability of the elbow.

Since its original description by O'Driscoll in 1991, PLRI is becoming increasingly recognized as a significant cause of elbow pathology. It is well documented that this problem results from an insufficiency of the radial ulnohumeral ligament and its related lateral structures, and that this insufficiency is usually the result of elbow trauma. Diagnosis has improved with the introduction of the PLRI test to identify the instability and advancing MR imaging capabilities of illustrating the injury. Whereas open reconstruction was previously the only definitive treatment, improving arthroscopic techniques provide a satisfactory alternative in stabilizing the elbow.

Arthroscopy↗

Arthroscopic capsulodesis of the lunotriquetral joint.

A case series consisting of 20 consecutive patients with persistent ulnar-sided mechanical wrist pain, lunotriquetral interosseous (LTIOL) ligament tears resulting in joint incongruity and increased laxity, and traumatic triangular fibrocartilage complex (TFCC) tears was reviewed. Each patient underwent an arthroscopic reduction and internal fixation (ARIF) of the lunotriquetral joint, arthroscopic disk-carpal (disklunate-ulnocapitate-disktriquetral, DL-UC-DT) ligament plication, and TFCC repair or débridement. There were 12 right wrists and 8 left wrists, of which 12 were dominant. The mean patient age was 33 years; 7 patients had workers' compensation claims and 2 had legal claims. Fourteen patients recalled a specific injury mechanism, such as hyperextension or rotation. The accompanying traumatic TFCC tears were peripheral in 15 and linear radial in 6 patients (one patient had concomitant peripheral and radial linear tears), and in 6 cases, the palmar ulnocarpal extrinsic ligaments were partially torn. The mean preoperative modified Mayo Wrist Score was 50, and at a mean of 3.1 years after surgery, the score had increased to 88. There were 13 excellent, 5 good, and 2 fair results. Four patients had complications, including transient tenderness along the extensor carpi ulnaris and persistent neuritis of a dorsal branch of the ulnar nerve. Overall wrist comfort and function, as indicated by the modified Mayo Wrist Scores, improved after arthroscopic stabilization of ulnar-sided wrist injuries (pinning of the lunotriquetral joint, disk-carpal ligament plication, and TFCC repair or débridement).

Adult↗

Laser-assisted capsulorrhaphy for multidirectional instability of the shoulder.

PURPOSE: The purpose of this study was to review the clinical results of laser-assisted capsulorrhaphy performed on 27 shoulders in 26 patients for multidirectional shoulder instability with minimum follow-up of 2 years. TYPE OF STUDY: Prospective case series. METHODS: Laser shrinkage was performed on the entire capsule. In patients in whom the rotator interval did not shrink, suture plication of this area was performed. All patients were evaluated with respect to the incidence of recurrent instability, need for reoperation, and ability to return to their previous level of activity or sports participation. In addition, all patients were rated as satisfactory or unsatisfactory using criteria established by Neer. RESULTS: Twenty-six of 27 shoulders (96%) remained stable and asymptomatic a minimum of 2 years after surgery. Of 14 athletes in the study group, 12 (86%) returned to their previous level of sports participation. CONCLUSION: Our results suggest that laser-assisted capsulorrhaphy is an effective treatment alternative for multidirectional instability.

Adolescent↗

Arthroscopic repair of partial-thickness tears of the rotator cuff.

Management of partial-thickness tears of the rotator cuff should include consideration of tear size, tear depth, patient age and activity level, and tear etiology. We present an arthroscopic technique for repair of articular surface partial-thickness tears that may promote healing by closing the tendon side-to-side, placing the debrided tendon end in contact with an abraded humeral surface. By repairing selected partial-thickness tears, progression of the tear and the need for subsequent repair may be prevented. Our preliminary results in 28 patients are encouraging and suggest that this technique is a useful adjunct to tendon debridement for articular surface partial-thickness tears of the rotator cuff.

Arthroscopy↗

Arthroscopic treatment of instability attributable to capsular injury or laxity.

Among the many causes of shoulder instability are traumatic capsular injury associated with the Bankart lesion and capsular laxity as seen in multidirectional instability. Previously, open surgical procedures were the most commonly accepted surgical treatment of these disorders. However, because of the foresight of surgeons such as Richard Caspari, arthroscopy rapidly is becoming the surgical treatment of choice. Current studies have shown a 97% satisfactory outcome of arthroscopic Bankart repair. Similarly, the arthroscopic treatment of multidirectional instability has produced a 93% satisfactory outcome. These results parallel the gold standard open surgical techniques of the past and subsequently have led to a change in the treatment of shoulder instability.

Arthroscopy↗

Insertion of CO2, CS2, and COS into iron(II)-hydride bonds.

The reactions between cis-Fe(dmpe)2H2 (dmpe = Me2PCH2CH2PMe2) (1) or cis-Fe(PP3)H2 (PP3 = P(CH2CH2PMe2)3) (2) and carbon dioxide (CO2), carbon disulfide (CS2), and carbonyl sulfide (COS) are investigated. At 300 K, additions of CO2 (1 atm), CS2 (2 equiv), and COS (1 atm) to 1 result in the formation of a stable transformato hydride, trans-Fe(dmpe)2(OCHO)H (3a), a trans-dithioformato hydride, trans-Fe(dmpe)2(SCHS)H (4a), and a trans-thioformato hydride, trans-Fe(dmpe)2(SCHO)H (5a), respectively. When CS2 and COS are added to cis-Fe(dmpe)2H2 at 195 K, a cis-dithioformato hydride, 4b, and a cis-thioformato hydride, 5b, respectively, are observed as the initially formed products, but there is no evidence of the corresponding cis-formato hydride upon addition of CO2 to cis-Fe(dmpe)2H2. Additions of excess CO2, CS2, and COS to 1 at lower temperatures (195-240 K) result in the formation of a trans-bis(formate), trans-Fe(dmpe)2(OCHO)2 (3b), a trans-bis(dithioformate), trans-Fe(dmpe)2(SCHS)2 (4c), and a cis-bis(thioformate), cis-Fe(dmpe)2(SCHO)2 (5c), respectively. trans-Fe(dmpe)2(SCHO)2 (5d) is prepared by the addition of excess COS at 300 K. Additions of CO2 (1 atm), CS2 (0.75 equiv), and COS (1 atm) to 2 at 300 K result in the formation of a thermally stable, geometrically constrained cis-formato hydride, cis-Fe(PP3)(OCHO)H (6a), a cis-dithioformato hydride, cis-Fe(PP3)(SCHS)H (7a), and a cis-thioformato hydride, cis-Fe(PP3)(SCHO)H (8a), respectively. Additions of excess CO2 and COS to 2 yield a cis-bis(formate), cis-Fe(PP3)(OCHO)2 (6b), and a thermally stable cis-bis(thioformate), cis-Fe(PP3)(SCHO)2 (8b), respectively. All complexes are characterized by multinuclear NMR spectroscopy, with IR spectroscopy and elemental analyses confirming structures of thermally stable complexes where possible. Complexes 3b and 5a are also characterized by X-ray crystallography.

Journal Article↗

Thermal versus suture treatment of symptomatic capsular laxity.

This article reviews the clinical results of unipolar thermal capsular shrinkage in 30 patients and compares that group to similar groups previously managed by laser-assisted capsulorrhaphy or by an arthroscopic capsular shift procedure. Patients were evaluated with respect to incidence of recurrent instability, the need for reoperation, and the ability to return to previous levels of activity or sports participation. Patients were rated as satisfactory or unsatisfactory based on criteria established by Neer. The results of this study suggest that thermal capsulorrhaphy with rotator interval plication is an effective treatment alternative for multidirectional instability, with results comparable to those previously reported with open and arthroscopic procedures.

Adolescent↗

Repair of the rotator cuff. Mini-open and arthroscopic repairs.

The repair of rotator cuff tears by traditional open subacromial decompression and rotator cuff tendon reapproximation has proved successful in restoring function and decreasing pain, but open rotator cuff repair has some inherent disadvantages. Postoperative detachment of the deltoid repair has been reported and results in significant morbidity. The open technique may also require a longer period of limited motion resulting in greater stiffness. Arthroscopically assisted mini-open repairs and, more recently, completely arthroscopic repairs of the rotator cuff have been developed and increasingly are being applied. Both techniques avoid detachment of the deltoid. The mini-open and arthroscopic approaches to rotator cuff repair have the added benefit of arthroscopic evaluation of the glenohumeral joint. The mini-open technique has the advantage of allowing the direct visualization of the cuff repair and allows surgeons to place the stitches in an open fashion, which is familiar to all surgeons. The mini-open technique also allows the placement of tension-absorbing stitches in the rare cases that they are needed. Mini-open techniques also allow the choice of bone anchors or osseous tunnels for fixation. The completely arthroscopic cuff repair has several potential advantages over the open and mini-open cuff repair techniques; first is the decreased disruption of the soft tissues, which may result in less scarring and adhesions. The procedure is the most cosmetically appealing of the techniques. Reduced postoperative pain is also cited as an advantage but has been demonstrated only in a single, nonrandomized study. Finally, if technical difficulties arise, the conversion to a mini-open repair can be done easily. In a few studies, arthroscopic cuff repair techniques have shown promise as an alternative to mini-open or open repair, but these results have been at the hands of a few surgeons who have extensive experience in arthroscopy of the shoulder. In contrast, the mini-open procedure requires modest arthroscopic skills and has a documented history of success. Nevertheless, arthroscopic rotator cuff repair is a viable and effective technique in the hands of surgeons with adequate skills, and this procedure is likely to become more commonly performed in the future as shoulder arthroscopic skills and instrumentation improve.

Arthroscopy↗

Basics of elbow arthroscopy.

With more innovation in arthroscopic equipment and surgical technique, elbow arthroscopy will continue to evolve and new indications will emerge. Strict adherence to the principles outlined above will allow the use of arthroscopy to treat a variety of elbow disorders in a safe and effective manner.

Arthroscopy↗

Elbow arthroscopy in trauma and reconstruction.

Arthroscopy of the elbow has become a valuable adjunct in the evaluation and treatment of elbow trauma and reconstruction. Arthroscopic visualization aids diagnosis and treatment while minimizing surgical trauma. The indications and techniques of elbow arthroscopy continue to expand and evolve. This article demonstrates the use of elbow arthroscopy as it relates to some of the topics in this volume. Arthroscopic setup, portal anatomy, technique, as well as an overview of trauma, loose bodies, bursitis, instability, arthrofibrosis, arthritis, and complications are discussed.

Arm Injuries↗

Osteochondritis dissecans of the elbow.

Osteochondritis dissecans of the elbow remains one of the leading causes of permanent elbow disability in adolescents and young adults engaged in throwing sports or gymnastics. The insidious onset of lateral elbow pain and restriction of full extension should alert the physician and prompt further investigation. Early recognition and appropriate treatment may allow for the prevention of long-term sequelae. Conservative care following early detection provides the best opportunity for a complete recovery. Surgical management at this point consists primarily of excision or removal of the osteochondral fragment with drilling or burring of the base of the lesion. Prognosis is fair with approximately half of all patients experiencing chronic pain or limitation of motion in the elbow. Research efforts are currently focusing on the treatment of established articular surface defects. Newer procedures such as the transplantation of osteochondral, perichondral, and periosteal tissues, chondrocyte transplantation, and the biochemical manipulation of the chondrocyte environment may provide us with exciting new approaches to an old problem. Osteochondritis dissecans of the elbow continues to present a difficult challenge to the treating physician. The current literature provides very little guidance for the clinician but active and innovative investigations into the treatment of articular cartilage defects may soon provide the answers.

Adolescent↗

The role of arthroscopy in the diagnosis and management of cartilaginous lesions of the wrist.

Articular cartilage lesions in the wrist are common. Diagnosis of these lesions is difficult, and the decision to operate may not be clear. A meticulous history and physical examination allows an accurate diagnosis. Appropriate surgical intervention can be useful in alleviating symptoms and returning the patient to normal activities. The origin, diagnosis, and treatment of cartilaginous lesions of the wrist are discussed in this article.

Adolescent↗