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Biomedical subjects

L H Schneider

Publications and source records attributed to L H Schneider.

At least 19 recordsLinked to original sources
PubMed1998

Revision of the ununited one-bone forearm.

Between 1975 and 1995, 7 patients were surgically treated for persistent forearm pain following previously unsuccessful attempts of constructing a radioulnar synostosis using interosseous bone grafting with either cross screw or pin fixation. These prior reconstructive procedures were salvage operations to address symptomatic radioulnar instability. The time interval between index operation and revision surgery was a mean of 12.6 months (range, 4-36 months). The postoperative follow-up period averaged 29.7 months (range, 11-61 months). To address these failed radioulnar arthrodeses, plate osteosynthesis and aggressive bone grafting were used in 5 of 7 patients (group 1) (4 with autologous graft and 1 with demineralized bone matrix). Union was achieved in all 5 patients after a single revision operation. Radiographic evidence of solid union was seen at approximately 4 months. In the remaining 2 patients (group 2), revision synostosis procedures were performed; these involved local bone grafting and repeat transverse screw fixation in 1 patient and iliac crest bone grafting alone in the other. One of these 2 patients progressed to union; the other had a persistent symptomatic fibrous union. The 5 patients in group 1 reported symptomatic relief, while the 2 patients in group 2 were dissatisfied. There were no postoperative complications in our series. Based on our findings, we advocate abundant bone grafting and plating for rigid internal fixation in failed radioulnar synostosis procedures.

Adult↗
PubMed1996

Tenolysis and capsulectomy after hand fractures.

There are well established operative procedures for salvage of function after fracture healing. When hand therapy measures have not achieved a satisfactory range of motion, it is reasonable to remove any hardware, if present, and lyse tendon adhesions that prevent tendon gliding. The exact cause of restricted motion and the location of adhesions are not always predictable preoperatively, so the surgeon should anticipate additional procedures such as dorsal/palmar capsulectomies in combination with extensor and/or flexor tenolysis. The use of local anesthesia for direct patient input during the procedure offers great advantages. In the ideal situation there should be a demonstrable functional need in a compliant patient with a well healed fracture and workable articular surfaces. Competent hand therapy should be available postoperatively. The patient's main risk is worsening of the situation if surgery is unsuccessful. A marginal finger with poor neurovascular status may be better served by going to arthrodesis or even amputation. Tenolysis and capsulectomy, when indicated, are useful procedures in the salvage of these difficult problems.

Anesthesia, Local↗
PubMed1995

Extensor tendon injuries at the distal interphalangeal joint.

The treatment options for the soft-tissue mallet finger, in both its acute and chronic forms, continue to generate some degree of controversy. Priority always should be given to nonoperative management of these injuries. This translates into a 6- to 8-week period of uninterrupted immobilization of the DIP joint with an external splint. Splinting has been shown to be highly effective, safe, and reproducible for both acute and chronic lesions. Even in the presence of an open injury, the value of splinting must be appreciated by the practitioner. The conversion of an acute closed soft-tissue injury to an open one is to be discouraged because of unacceptable complication rates. When surgery is contemplated, our first option would be the placement of a transarticular Kirschner wire at the DIP joint. If external splinting fails in an acute injury, an argument certainly can be made for a second trial of conservative management, and we offer this alternative to such patients. We find that some patients will not tolerate a second period of immobilization, and in most cases, we offer surgery in these failed cases. Surgical choice, again, would be a transarticular Kirschner wire. Another choice would be one of the salvage procedures, such as central slip tenotomy, with the expectation of a good result. In summary, mallet injuries are treated using closed, nonoperative techniques. The period of time after injury that this nonoperative treatment can be delayed and still be effective is being extended and the absolute outside time limit still is not known. When surgery is done, we prefer the simple placement of a transarticular Kirschner wire for 6 to 8 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Extensor tendon grafting on the dorsum of the hand in massive tendon loss.

After severe injury to the dorsum of the hand, it may not be possible to directly repair the extensor tendons. Patients in this article were treated by initial skin replacement with pedicle flaps for coverage prior to extensor tendon grafting. Multiple operative procedures were necessary, but restoration was uniformly successful.

Finger Joint↗
PubMed1995

Treatment of the chronic boutonniere deformity by extensor tenotomy.

A patient with a chronic boutonniere deformity often experiences more difficulty because of the hyperextension deformity at the distal joint, rather than the lack of extension at the proximal interphalangeal joint. It is in these cases that restoration of flexion at the terminal joint by tenotomy of the terminal extensor tendon is of most value.

Adult↗
PubMed1994

Fractures of the distal interphalangeal joint.

Displaced fractures at the distal end of the middle phalanx require reduction if function is to be restored at the distal joint. Fractures at the base of the distal phalanx take on additional significance because of the insertions of the flexor and extensor tendons. The palmar articular fracture, when displaced, needs surgical replacement to restore flexor profundus function. In contrast, the displaced dorsal lip fracture, the mallet fracture, can be treated closed with the expectation of excellent results.

Finger Injuries↗
PubMed1993

Scaphoid excision and capitolunate arthrodesis for radioscaphoid arthritis.

Eighteen patients with symptomatic radioscaphoid arthritis had scaphoid excision and capitolunate arthrodesis. Eight patients also had a silicone scaphoid replacement. The follow-up period averaged 3 years. Fusion was solid in 12 cases at an average of 8 weeks, and pain was significantly less at follow-up evaluation. Six patients had a pseudarthrosis and five had persistent pain. Immobilization in the pseudarthrosis group averaged 6 weeks, which was significantly less than the group that fused. Two patients underwent successful repeat fusions. Wrist extension averaged 26 degrees, flexion 34 degrees, radial deviation 11 degrees, and ulnar deviation 24 degrees. Grip strength averaged 25 kg. Presence of an implant had no significant effect on motion or strength. Pin track infection and pseudarthrosis were the main complications. Pain relief, functional motion, good strength, and patient satisfaction can be expected after scaphoid excision and solid capitolunate arthrodesis. Kirschner wires should be buried subcutaneously to avoid infection. The addition of a scaphoid implant offered no advantage over simple scaphoid excision.

Arthritis↗
PubMed1993

Fractures of the shaft of the radius after treatment of Colles fractures with pins and plaster or external fixation.

Refracture of the radius through a pin site after the removal of pins and plaster or an external fixator for Colles fracture is rarely mentioned in the literature. We present the details of three such cases and review two others reported in the literature. Our aim is to alert orthopedists to the potential for this complication. Patients with superficial or deep pin tract infections appear to be at greater risk.

Accidental Falls↗
PubMed1993

Arthroplasty of the metacarpophalangeal joints with use of silicone-rubber implants in patients who have rheumatoid arthritis. Long-term results.

The long-term results of 144 arthroplasties of the metacarpophalangeal joints, with use of silicone-rubber implants, were reviewed for twenty-seven patients (thirty-six hands) who had rheumatoid arthritis. The operations were all performed or supervised by the same surgeon. All patients had an arthroplasty of the metacarpophalangeal joint of all four fingers, and all had subjective and objective clinical evaluation and roentgenographic assessment. Relief of pain, the cosmetic appearance of the hand, the range of motion of the metacarpophalangeal and proximal interphalangeal joints, and the presence of residual deformity were evaluated. The average duration of follow-up was eight years and six months (range, five years to sixteen years and three months). Preoperatively, the mean active-extension deficit of the metacarpophalangeal joints ranged from 53 degrees (index finger, right hand) to 70 degrees (little finger, left hand) and the mean flexion ranged from 84 degrees (index finger, right hand) to 94 degrees (little finger, left hand). At the early follow-up evaluation (average, four months postoperatively; range, two to six months), the mean extension deficit had improved to a range of 7 degrees (little finger, right hand) to 19 degrees (index finger, left hand), and mean flexion ranged from 56 degrees (little finger, left hand) to 66 degrees (ring fingers). The range of motion had improved from a non-functional arc of flexion to a more functional arc of extension. At the time of the latest follow-up visit, the motion of the metacarpophalangeal joints had not deteriorated.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Enkephalin is a competitive antagonist of cholecystokinin in the gastrointestinal tract, as predicted from prior conformational analysis.

Prior calculations based on ECEPP (Empirical Conformational Energies for Peptides Program) of the low energy minima for cholecystokinin (CCK) and Met-enkephalin have demonstrated that significant structural features of these two peptides are identical. This result suggested the possibility that Met-enkephalin, as well as other enkephalin analogues of similar structure, could associate with receptors for CCK. To test this theoretical result, we examined the ability of Met-enkephalin and its analogues to bind to peripheral CCK receptors in the rat gastrointestinal tract; in particular, we measured the ability of the opiate peptide to inhibit the effects of CCK in a physiological assay system which we have previously characterized: CCK-induced contraction of the isolated rat pyloric sphincter. We find that Met-enkephalin is an antagonist of the CCK-8-induced contraction, with a IC50 of 110 nM. Furthermore, antibodies against CCK were found to cross-react with Met-enkephalin and its analogues in a manner which suggests a distinct structure-activity relationship. These experimental results strongly support the theoretical results of conformational analysis showing structural similarity between enkephalin and CCK. They further suggest that enkephalins could modulate the response of CCK systems under physiological conditions.

Amino Acid Sequence↗
PubMed1992

Tension band arthrodesis of finger joints: a retrospective review of 76 consecutive cases.

Arthrodesis of finger joints is a reliable method of treating finger joint instability and arthritis. Tension band arthrodesis is an effective method of stable fixation that uses readily available and inexpensive materials. Because fixation is rigid, patients are allowed to move adjacent joints, usually within 1 week after surgery. The results of 76 tension band arthrodesis procedures performed since 1982 in 63 patients were reviewed. Follow-up ranged from 6 to 38 months. The average time to radiographic fusion was 12 weeks (range, 4 to 64 weeks). One joint failed to fuse and developed a stable, asymptomatic nonunion; thus the fusion rate was 99%. Technical problems that occur with the method include nonparallel pin placement and penetration of pin tips, leading to painful impingement of the soft tissues. A pin-placement guide has been developed to minimize these problems.

Arthritis↗
PubMed1991

Infra-additivity of combined treatments with selective D1 and D2 receptor antagonists for inhibiting sucrose reinforcement.

Selective antagonists of either the D1 receptor (SCH 23390) or of the D2 receptor (raclopride) produce a dose-related inhibition of sucrose sham feeding in the rat. We investigated the effect of combined treatments with these antagonists on sucrose sham feeding and observed infra-additivity of inhibition across a range of doses. On the basis of this observed occlusive relationship, we conclude that the relevant D1 and D2 receptor mechanisms mediating sweet taste reward do not function independently.

Animals↗
PubMed1991

Resection arthroplasty at the basilar joint of the thumb.

Resection arthroplasty at the base of the thumb has a long history in the surgical literature. It is a less complex procedure than other operative approaches; pain relief along with useful hand function is reliably achieved. Sixty-six trapezial resection arthroplasties using either a tendon or Gelfoam spacer (The Upjohn Co, Kalamazoo, MI) were reviewed with improvement noted in 62 patients.

Arthroplasty↗
PubMed1991

Proximal interphalangeal joint arthroplasty: the volar approach.

Reconstruction of the proximal interphalangeal joint by arthroplasty using the Swanson implant is greatly simplified by the volar approach. The extensor tendon system is not violated, making an immediate motion program feasible. Combining this approach with local anesthesia allows for active and complete evaluation of the technique during the operative procedure.

Arthritis↗
PubMed1991

The open palm technique.

Dupuytren's disease presents a difficult problem that should not be treated casually. It is a continuing, unpredictable condition in which surgery is the only treatment available when contracture occurs. Surgery itself may cause an acceleration of the disease. Patients should be made aware that this is a continuing problem, often unpredictable in its course, with and without treatment. It is a pervasive disease, and when surgery is unsuccessful, the hand that underwent surgery may worsen. The open palm technique is a useful technique for avoiding complications in the early postoperative period. It is particularly useful in those patients with significant metacarpophalangeal joint contractures at more than one finger. The open palm technique does not affect the long-term outcome in these patients.

Dupuytren Contracture↗
PubMed1991

Classification of distal radioulnar joint disorders.

The wrist is one of the most complex articulations in the human body. The distal radioulnar joint (DRUJ) is particularly controversial, enduring as the area least understood with regard to anatomy and pathomechanics. The popular systems of classifying DRUJ disorders are based on etiology and treatment, but this approach has inspired schemes that are cumbersome, redundant, and incomplete. The need for an improved system prompted us to devise a simplified system that is based on the pathomechanics of dysfunction and the mechanical requirements for optimal joint function.

Humans↗
PubMed1991

Radioulnar joint fusion for distal radioulnar joint instability.

Each one of this small group of patients illustrates a rare indication for the radioulnar joint fusion procedure in distal radioulnar joint instability. The case histories tell of a last ditch effort to salvage function in an extremity crippled by painful radioulnar instability after excision of the distal ulna. The fusions healed slowly and two required repeat surgery to achieve union. Today we would routinely add iliac bone graft to the fusion area to hasten healing. Rarely indicated, this is a salvage procedure that is done after failure of other procedures geared to preserve the rotation of the forearm. These patients all had successful salvage of their extremities for activities of daily living, but only one returned to his labor job. All were worker's compensation cases in physical jobs. Two patients had had prior radiocarpal fusions, making them even more restricted in function. This procedure should be kept in mind to be used in the rare cases of painful instability of the distal radioulnar joint when traditional motion-preserving procedures have failed.

Adult↗