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Biomedical subjects

M P Rosenwasser

Publications and source records attributed to M P Rosenwasser.

At least 19 recordsLinked to original sources
PubMed2006

Gross and histological analysis of healing after dog flexor tendon repair with the Teno Fix device.

The purpose of this study was to examine the in vivo characteristics of the stainless-steel Teno Fix device used for flexor tendon repair. The common flexor digitorum superficialis tendon was transected in 16 dogs and repaired with the device. The animals were euthanized at 3, 6, or 12 weeks postoperatively. Difficulties with cast immobilization led nine of 16 animals to be full weight bearing too early, leading to rupture of their repairs. The seven tendons with successful primary repairs (gap <2mm) underwent histological examination. This in vivo study demonstrates that use of the Teno Fix in "suture" of dog flexor tendons did not lead to scarring at the tendon surface, does not cause an inflammatory reaction within the tendon and does not interfere with tendon healing.

Animals↗
PubMed2003

Cavernous nerve graft reconstruction during radical prostatectomy or radical cystectomy: safe and technically feasible.

High local stage prostate and bladder cancers frequently require wide local resection and sacrifice of one or both cavernous nerves to achieve a negative surgical margin, thus resulting in erectile dysfunction. This is a report on preliminary experience with cavernous nerve graft reconstruction using sural nerve grafts with radical prostatectomy or radical cystectomy.Pre-operative evaluation was performed and consent was obtained in 14 potent men with prostate (11) or bladder (three) cancer. Sural nerve grafts of resected cavernous nerves were performed using a microsurgical technique. Post-operative treatment (Sildenafil or Alprostadil) was pursued until return of spontaneous function, documented by interview and adequate scores (>20) in the erectile function (EF) domain of the International Index of Erectile Function (IIEF).Twelve unilateral nerve grafts were performed, 10 during radical prostatectomy and two during radical cystoprostatectomy. Two procedures were technically not possible because of locally advanced disease. Mean age was 57.5 y (36-68 y). Mean follow up was 16.1 months (7-28 months). Pathological stage of prostate cancer was pT2 in 2, pT3 in 7 and pT4 in one. Surgical margins were positive in five out of 10 (50%), and two (20%%) had positive lymph nodes. Four patients (three post prostatectomy and one post cystectomy) were fully potent. Additionally, one patient post prostatectomy had improving partial erections. Six patients post prostatectomy and one patient post cystectomy had no erections. The only complication was one superficial wound infection in the sural nerve donor site. Preliminary experience shows that sural nerve grafts are feasible and safe after radical prostatectomy and cystectomy. However, candidates usually present with high stage disease, high risk for recurrence and frequent requirement for adjuvant therapy that further compromises erectile function. Randomized studies with more patients and long follow-up periods are necessary in order to define the ideal candidate for nerve graft procedures.

Adult↗
PubMed2003

Osteochondral repair of primate knee femoral and patellar articular surfaces: implications for preventing post-traumatic osteoarthritis.

The risk of post-traumatic osteoarthritis following an intra-articular fracture is determined to large extent by the success or failure of osteochondral repair. To measure the efficacy of osteochondral repair in a primate and determine if osteochondral repair differs in the patella (PA) and the medial femoral condyle (FC) and if passive motion treatment affects osteochondral repair, we created 3.2 mm diameter 4.0 mm deep osteochondral defects of the articular surfaces of the PA and FC in both knees of twelve skeletally mature cynomolgus monkeys. Defects were treated with intermittent passive motion (IPM) or cast-immobilization (CI) for two weeks, followed by six weeks of ad libitum cage activity. We measured restoration of the articular surface, and the volume, composition, type II collagen concentration and in situ material properties of the repair tissue. The osteochondral repair response restored a mean of 56% of the FC and 34% of the PA articular surfaces and filled a mean of 68% of the chondral and 92% of the osseous defect volumes respectively. FC defect repair produced higher concentrations of hyaline cartilage (FC 83% vs. PA 52% in chondral defects and FC 26% vs. PA 14% in osseous defects) and type II collagen (FC 84% vs. PA 71% in chondral defects and FC 37% vs. PA 9% in osseous defects) than PA repair. IPM did not increase the volume of chondral or osseous repair tissue in PA or FC defects. In both PA and FC defects, IPM stimulated slightly greater expression of type II collagen in chondral repair tissue (IPM 81% vs. CI 74%); and, produced a higher concentration of hyaline repair tissue (IPM 62% vs. CI 42%), but IPM produced poorer restoration of PA articular surfaces (IPM 23% vs. CI 45%). Normal articular cartilage was stiffer, and had a larger Poisson's ratio and less permeability than repair cartilage. Overall Cl treated repair tissue was stiffer and less permeable than IPM treated repair tissue. The stiffness, Poisson's ratio and permeability of femoral condyle cast immobilized (FC CI) treated repair tissue most closely approached the normal values. The differences in osteochondral repair between FC and PA articular surfaces suggest that the mechanical environment strongly influences the quality of articular surface repair. Decreasing the risk of post-traumatic osteoarthritis following intra-articular fractures will depend on finding methods of promoting the osteochondral repair response including modifying the intra-articular biological and mechanical environments.

Animals↗
PubMed2001

Nerve entrapment in athletes.

Nerve entrapment syndromes can occur in athletes. The repetitive and vigorous use or overuse of the upper extremity makes the athlete particularly vulnerable to disorders of peripheral nerves. Understanding the clinical signs and symptoms is essential to treatment. The pertinent anatomy, clinical presentation, treatment, and rehabilitation necessary for return to sports for various nerve entrapments have been described. This should enable the physician caring for the athlete to help prevent injury and to guide appropriate treatment, if intervention becomes necessary.

Arm↗
PubMed2001

Complete median nerve transection as a complication of carpal tunnel release with a carpal tunnel tome.

A 48 year-old right-hand-dominant man presented to our institution with paresthesia and loss of feeling along the median nerve distribution of the right hand 1 week after undergoing minimally open carpal tunnel release with the Biomet Indiana Tome at another hospital. At surgery, transection of the median nerve was discovered and repaired. This is the first report of a complete median nerve transection using the revised carpal tunnel tome with a single-pass technique.

Carpal Tunnel Syndrome↗
PubMed2000

Osteoarthritic changes in the biochemical composition of thumb carpometacarpal joint cartilage and correlation with biomechanical properties.

The biochemical composition and biomechanical properties of articular cartilage from 53 human thumb carpometacarpal (CMC) joints from cadavers aged 20 to 79 years were measured and studied in normal, mildly fibrillated, and advanced osteoarthritic (OA) joints. Statistical analyses were performed to determine the correlations between the compositional measures and biomechanical properties. For these CMC joint tissues we found that water content increased, proteoglycan content decreased, and collagen content per dry weight remained unaltered with progression of OA degeneration. We also found that with disease progression, as defined by an OA staging score, the aggregate modulus (ie, compressive stiffness) decreased, along with an unexpected moderate decrease in permeability. This latter finding appears to be specific to CMC cartilage degeneration since articular cartilage from knees and hips generally demonstrates an increase in permeability with water content and OA score. Correlations between biochemical composition and biomechanical properties were found to be stronger in joints with OA than in joints without OA. This finding suggests that OA changes in biochemical composition, relative to baseline normal values, directly affect the biomechanical properties of cartilage, even though the baseline compositional values themselves do not directly determine the magnitude of the biomechanical properties in normal tissue.

Adult↗
PubMed2000

Examination of the anatomic relationship of the proximal germinal nail matrix to the extensor tendon insertion.

The purpose of this study was to delineate the relationship of the terminal extensor tendon insertion to the proximal limit of the germinal nail matrix. Sixteen fresh-frozen human cadaver fingers without any evidence of trauma (average age, 55 years; 3 males and 1 female) were used for this study. Under x25 magnification the proximal limit of the germinal nail matrix and the terminal bony insertion of the extensor tendon were identified. The distance from the terminal tendon insertion to the germinal nail matrix was ascertained using precision calipers. The average distance from the terminal extensor tendon insertion to the proximal edge of the germinal nail matrix was found to be 1.2 mm. We conclude that the proximal limit of the germinal matrix is extremely close to the terminal extensor tendon bony insertion. When the extensor tendon insertion is visualized during operative exposures of the dorsum of the distal phalanx, care should be taken to avoid damaging the germinal matrix. Conversely, when the nail bed is being completely excised, visualization of the insertion of the extensor tendon will indicate that further proximal dissection is not required.

Adolescent↗
PubMed2000

Thenar insertion of abductor pollicis longus accessory tendons and thumb carpometacarpal osteoarthritis.

Although the etiology of osteoarthritis of the thumb carpometacarpal (CMC) joint remains unclear, some theories have focused on variations in the local anatomy of the abductor pollicis longus tendon insertion. This cadaver study of 68 specimens analyzed the relationship between a thenar insertion of an accessory abductor pollicis longus tendon and the presence and severity of thumb CMC osteoarthritis. The joint cartilage surfaces were visually graded for degenerative changes. Thirty-five of 68 specimens (51%) had a thenar insertion, most frequently inserting on either the abductor pollicis brevis or opponens pollicis fascia or muscle belly. No significant association between a thenar insertion and thumb CMC arthritis was observed. Conversely, increasing age was noted to have a significant association with degenerative joint disease. Thus, these findings indicate that a thenar slip of the abductor pollicis longus tendon does not correlate with the presence or severity of CMC osteoarthritis.

Adolescent↗
PubMed2000

The assessment and treatment of nerve dysfunction after trauma around the elbow.

Nerve dysfunction after trauma around the elbow can lead to significant long-term pain and functional deficit. Fortunately, most of these injuries are neurapraxias that will recover spontaneously after conservative treatment. The necessity and time frame for surgical intervention for specific patterns of nerve dysfunction remains controversial. Often surgical exploration exacerbates rather than alleviates the presenting nerve problem. Distal humeral shaft fractures, elbow dislocations, Monteggia fracture-dislocations, supracondylar fractures in children, and proximal forearm trauma all have been associated with various types of nerve injuries with a variable degree of recovery. The early recognition of nerve dysfunction combined with appropriate treatment measures is the key to successful outcome.

Adult↗
PubMed2000

Management of acute and chronic biceps tendon rupture.

In conclusion, the authors believe that younger high-demand patients should be offered the option of surgical repair; can be performed through the preferred single anterior incision with two suture anchors. Chronic tears, even with retraction, may be successfully reconstructed using a free tendon graft, often the flexor carpi radialis. Complications, including radial nerve palsy and proximal radioulnar synostosis, can be avoided with the single-incision technique. Older, low-demand patients can be rehabilitated and have excellent function without acute repair. Partial tendon injuries, for the most part, may be treated with rest and rehabilitation and explored only for chronic, unremitting pain. The authors believe that the single anterior approach should be used over the previously popularized two-incision technique.

Age Factors↗
PubMed1999

Chronic elbow instability.

Chronic elbow instability without fractures in adults can be broken down into three types: (1) valgus instability, (2) posterolateral rotator instability, and (3) isolated radial head instability. By far the most common is valgus instability, which usually occurs in throwing athletes as a result of repetitive microtrauma to the anterior band of the medial collateral ligament. Surgical treatment is aimed at reconstruction of the anterior band of the medial collateral ligament. Posterolateral rotatory instability is much less common and is diagnosed by the lateral pivot-shift test of the elbow. It is usually the result of an undiagnosed acute injury to the lateral ulnar collateral ligament. Surgical treatment is aimed at its reconstruction. Isolated radial head subluxation in adults is extremely rare. The essential lesion is a disruption of the annular ligament. Surgical treatment is either radial head resection or reconstruction of the annular ligament.

Chronic Disease↗
PubMed1999

Lengthening of pediatric forearm deformities using the Ilizarov technique: functional and cosmetic results.

Eight patients (average age, 10 years) had a unilateral forearm lengthening procedure using the technique developed by Ilizarov. The procedure was performed in 4 patients with radial agenesis, in 2 with multiple hereditary exostosis, in 1 with ulnar agenesis, and in 1 with multiple enchondromatosis. Patients underwent distraction osteogenesis through either a unifocal or bifocal corticotomy. Forearm length increased on average 6.0 cm (range, 3.6-8.1 cm) or 54% (range, 21% to 94%) with a lengthening index of 1.3 months per centimeter (range, 0.6-1.9 months per centimeter). The length of follow-up averaged 4.5 years and involved office examinations with task evaluation and a questionnaire addressing function and appearance. Limb length discrepancy at follow-up measured 3.7 cm (range, 0.0-8.0 cm). Lengthening of the forearm was found to improve upper extremity function; it allowed the patient to reach distant body parts and to perform select activities requiring near-equal arm length. Forearm lengthening also improved the appearance of the arm if adequate soft tissue was preserved. Full restoration of arm length was not a requirement for a successful outcome and patient satisfaction with the results of the procedure was high.

Adolescent↗
PubMed1999

Treatment of unstable distal radius fractures with cancellous allograft and external fixation.

Unstable fractures of the distal radius continue to pose a challenge to the hand surgeon. Adjunctive bone grafting is often required to augment structural integrity and aid healing. Because of the risks inherent to bone autograft harvest, however, freeze-dried, irradiated cancellous bone allograft has been used to treat unstable distal radius fractures with severe metaphyseal comminution. Seventeen patients with such fractures (mean age, 70 years; 2 males and 15 females) were treated with bone allograft and external fixation with or without internal fixation. The outcome was evaluated using the modified Mayo wrist score, demonstrating 3 excellent, 8 good, 6 fair, and no poor results on follow-up examination (mean follow-up period, 23 months; range, 7-43 months). The patients were requested to return for follow-up review between 1997 and 1998. These results show that cancellous bone allograft is a useful adjunct to external fixation in the treatment of unstable distal radius fractures.

Aged↗