Biomedical subjects

Douglas C Ross

Publications and source records attributed to Douglas C Ross.

10 recordsLinked to original sources

PubMed2006

Steroid injections in the management of trigger fingers.

OBJECTIVES: The most commonly used primary treatment for trigger fingers is corticosteroid injection in the flexor tendon sheath, followed by surgical release if unsuccessful. This study examines the surgical and nonsurgical treatment of patients with trigger fingers presenting to a large Canadian tertiary referral center. The treatment success and side-effect profile of steroid injection therapy and surgical release were examined in the context of comorbid illness, specifically, diabetes mellitus. DESIGN: Retrospective review of all patients with trigger finger who were seen by the senior authors between January 1999 and June 2004. RESULTS: In the study period, 118 trigger digits were treated. This study included 92 nondiabetic, 21 type 2 diabetic, and five type 1 diabetic trigger fingers. Of the 89 digits that received at least one steroid injection, 46 (52%) resolved completely and 42 (47%) were improved. Nondiabetic digits were treated successfully in 40 out of 70 digits (57%) with steroid injection therapy. Diabetic patients had a success rate of 6 of 19 (32%) with steroid injections, which is significantly lower than nondiabetics (P = 0.04). All type 1 diabetics (n = 5) required surgical treatment. Surgical treatment was successful in 71 of 72 (99%) digits. No side effects of steroid injection were noted, and short-term postoperative side effects were noted in 26 of 72 surgical patients (36%). No statistically significant differences were found in surgical complication rates in diabetics vs. nondiabetics or type 1 diabetics vs. type 2 diabetics. CONCLUSIONS: Steroid injection therapy should be the first-line treatment of trigger fingers in nondiabetic patients. In diabetics, the success rate of steroid injection is significantly lower. Injection therapy for type 1 diabetics was ineffective in this study. Surgical release of the first annular (A1) pulley is most effective overall in diabetics and nondiabetics alike, with no higher rates of surgical complications in diabetics.

Adult↗

PubMed2006

Sensibility following innervated free TRAM flap for breast reconstruction.

BACKGROUND: The free transverse rectus abdominis musculocutaneous (TRAM) flap has proven to be a reliable means of recreating the aesthetic breast form after mastectomy. The purpose of this study was to determine whether neurotization of the free TRAM flap improved sensation of the reconstructed breast. METHODS: Twenty-seven patients undergoing 37 free TRAM flap reconstructions were randomized to receive either an innervated (12 patients, 18 breasts) or a noninnervated flap (15 patients, 19 breasts). A nerve repair between the T10 intercostal of the TRAM flap and the anterior sensory branch of the fourth intercostal nerve was performed for innervation. Sensory testing (Semmes-Weinstein monofilaments, hot-cold discrimination, two-point discrimination) was performed by one blinded examiner in a standardized pattern. RESULTS: Mean follow-up was 16 months. Demographic analysis revealed no significant differences in patient age, height, smoking, radiation therapy, and nipple-areola reconstruction between patient groups (p > 0.3). Patients in the noninnervated group, however, were heavier (p = 0.03). Preoperative sensation was not significantly different in the noninnervated and innervated groups. Postoperative pressure threshold and temperature discrimination were significantly improved in the innervated flaps (p < 0.05). Noninnervated flaps displayed a pattern of increasing sensibility from the center toward the periphery while innervated flaps regained sensation throughout. CONCLUSIONS: Innervation of the free TRAM flap provides improved sensation to the reconstructed breast and is a simple adjunct to breast reconstruction.

Adult↗

PubMed2005

Scalp and forehead reconstruction.

The reconstruction of defects that involve the scalp and forehead presents unique aesthetic and functional challenges. This article reviews the surgical anatomy of these regions and presents an algorithm for decision making in reconstructive surgery. Nonmicrosurgical techniques are briefly reviewed. The microsurgical reconstruction of scalp and forehead defects differs from the more common oropharyngeal reconstructions in several ways, including flap choices, choices for recipient vessels, and the opportunity to use conventional and microsurgical techniques simultaneously to improve outcomes. Each of these considerations is reviewed and the authors' preferred techniques presented.

Algorithms↗

PubMed2005

Comparison of sagittal computed tomography and plain film radiography in a scaphoid fracture model.

PURPOSE: To compare computed tomography (CT) in the sagittal plane and plain film radiography in the diagnosis of scaphoid fracture and displacement. METHODS: Three groups of scaphoids (no fracture, undisplaced fractures, fractures with displacement > 1 mm) from 11 cadaver wrists were prepared. Each wrist then was imaged by using sagittal plane CT scans in the long axis of the scaphoid and plain film imaging using 6 standard scaphoid views. Eight readers from 3 specialties read each group of images. The sensitivity and specificity for the presence of fracture and fracture displacement were calculated in addition to interobserver and intraobserver reliabilities for each. RESULTS: Both x-ray and CT scans showed a high sensitivity and specificity in detecting the presence of a fracture with no interspecialty differences. The sensitivity for displacement greater than 1 mm was lower for both modalities with no inter-specialty differences. The specificities for x-ray and CT for detecting displacement greater than 1 mm were 84% and 89%, respectively. The poor sensitivity for detecting displacement was explained by the low sensitivity of CT in the diagnosis of radial/ulnar displacement compared with x-ray and the low sensitivity of x-ray in the diagnosis of volar/dorsal displacement compared with CT scans. When fellowship-trained hand surgeons reviewed CT scans and plain films together the sensitivity and specificity for fracture displacement increased significantly. Intraobserver and interobserver reliability for both x-ray and CT scans was excellent except for the reading of CT scans among emergency physicians and for the reading of plain x-rays among senior house staff, representing moderate agreement. CONCLUSIONS: Based on these results both CT scans in the sagittal plane and plain films accurately detect fractures with a high degree of interobserver and intraobserver reliability, but they fall short in detecting displacement greater than 1 mm.

Aged↗

PubMed2005

A triple-blinded randomized trial comparing the hemostatic effects of large-dose 10% hydroxyethyl starch 264/0.45 versus 5% albumin during major reconstructive surgery.

In Canada, hydroxyethyl starch 264/0.45 (HES 264/0.45; molar weight 264 kDa, molar substitution 0.45) has largely replaced albumin as the colloidal fluid of choice for perioperative intravascular volume expansion. The maximum recommended dose of HES 264/0.45 is 28 mL/kg; however, there are no clinical data supporting this limit. In this study we compared the hemostatic effects of HES 264/0.45 versus 5% albumin in doses up to 45 mL/kg over 24 h during major reconstructive head and neck surgery. Fifty patients were randomized to receive HES 264/0.45 or 5% human albumin from the induction of anesthesia until 24 h thereafter. Both albumin and HES 264/0.45 effectively maintained physiologic variables in the perioperative and postoperative periods. The partial thromboplastin time and international normalized ratio were significantly increased in the HES 264/0.45 group compared with the albumin group after infusion of 30 mL/kg and 45 mL/kg (P < 0.05). Factor VIII activity and von Willebrand factor level were significantly reduced in the HES 264/0.45 group compared with the albumin group after infusion of 15 mL/kg, 30 mL/kg, and 45 mL/kg (P < 0.05). Significantly more subjects in the HES 264/0.45 group received allogeneic red blood cell transfusions (P < 0.02). We conclude that HES 264/0.45 infusions >30 mL/kg over 24 h impair coagulation to a greater extent than albumin, possibly leading to more allogeneic transfusions.

Anesthesia↗

PubMed2005

Outcomes in carpal tunnel syndrome: symptom severity, conservative management and progression to surgery.

PURPOSE: This study investigated the relationship between severity of symptoms and success of nonoperative and operative treatment in patients with carpal tunnel syndrome (CTS). METHODS: An observational cohort study regarding the management of CTS was conducted. Thirty patients referred to a tertiary hand centre with a diagnosis of CTS were prospectively followed. Twenty-five of the patients (47 affected hands) were available for long-term follow up to determine management outcomes. Self-report symptoms and physical impairments were assessed and documented at baseline, 6 weeks, and 12 weeks using the CTS Severity Score (SSS), the Disability-Shoulder, Arm and Hand Score (DASH), and the Levine Functional Score. Longer-term follow-up was conducted to identify status on outcome measures and whether patients proceeded to surgery. RESULTS: Those who proceeded to surgery (n = 27/47 hands) had higher initial CTS SSS and DASH scores and also maintained higher scores compared to those who improved with conservative management (p < 0.05). Improvements occurred in the SSS (P < 0.0001), Functional Score (P < 0.001), and DASH score (P < 0.05) following surgery in the patients resistant to conservative management. Recovery of grip and dexterity was less satisfactory. DISCUSSION: This study suggests that the SSS is useful in the triage of patients on surgical wait-lists as patients with high initial scores or failure to change in short-term follow-up are likely to proceed to surgical release. Despite prolonged symptoms and previous treatment, patients with lower SSS scores had moderate success with a second trial of conservative management.

Adult↗

PubMed2004

Wound healing-associated proteins Hsp47 and fibronectin are elevated in Dupuytren's contracture.

BACKGROUND: Dupuytren's contracture or disease (DD) affects hand function by causing irreversible contraction of the palmar fascia. Histological analysis has shown that DD and wound granulation tissue share many cellular and biochemical characteristics, suggesting that DD may be an exaggerated wound-healing response. The goal of the present study was to examine the possible involvement of two important wound-healing-associated proteins-heat shock protein 47 (Hsp47), fibronectin (Fn), and its oncofetal isoforms-in DD, using clinical tissue samples and primary cell cultures. MATERIALS AND METHODS: We examined the expression of Hsp47, Fn, and an oncofetal isoform of fibronectin (IIICS) in both normal and disease-matched surgical specimens and primary cell cultures using Western blot analysis, and immunocytochemistry (ICC). RESULTS: Our results indicate that Hsp47 and total fibronectin is elevated in DD lesional tissue. In addition, Western and ICC analysis of patient-matched (normal and disease) primary cultures show significantly elevated levels of oncofetal fibronectin (IIICS spliced variant) within disease primary cell cultures. CONCLUSIONS: The high levels of expression of Hsp47 and adult and oncofetal fibronectin in DD suggests that cell-mediated alterations in the extracellular environment may play an important role in the disease process. Furthermore, the involvement of these wound healing-associated proteins in DD supports the notion that this disease may be an exaggerated form of wound healing.

Blotting, Western↗

PubMed2003

Elevated levels of beta-catenin and fibronectin in three-dimensional collagen cultures of Dupuytren's disease cells are regulated by tension in vitro.

BACKGROUND: Dupuytren's contracture or disease (DD) is a fibro-proliferative disease of the hand that results in the development of scar-like, collagen-rich disease cords within specific palmar fascia bands. Although the molecular pathology of DD is unknown, recent evidence suggests that beta-catenin may play a role. In this study, collagen matrix cultures of primary disease fibroblasts show enhanced contraction and isometric tension-dependent changes in beta-catenin and fibronectin levels. METHODS: Western blots of beta-catenin and fibronectin levels were determined for control and disease primary cell cultures grown within stressed- and attached-collagen matrices. Collagen contraction was quantified, and immunocytochemistry analysis of filamentous actin performed. RESULTS: Disease cells exhibited enhanced collagen contraction activity compared to control cells. Alterations in isometric tension of collagen matrices triggered dramatic changes in beta-catenin and fibronectin levels, including a transient increase in beta-catenin levels within disease cells, while fibronectin levels steadily decreased to levels below those seen in normal cell cultures. In contrast, both fibronectin and beta-catenin levels increased in attached collagen-matrix cultures of disease cells, while control cultures showed only increases in fibronectin levels. Immunocytochemistry analysis also revealed extensive filamentous actin networks in disease cells, and enhanced attachment and spreading of disease cell in collagen matrices. CONCLUSION: Three-dimensional collagen matrix cultures of primary disease cell lines are more contractile and express a more extensive filamentous actin network than patient-matched control cultures. The elevated levels of beta-catenin and Fn seen in collagen matrix cultures of disease fibroblasts can be regulated by changes in isometric tension.

Biomechanical Phenomena↗

PubMed2003

Beta-catenin expression in Dupuytren's disease: potential role for cell-matrix interactions in modulating beta-catenin levels in vivo and in vitro.

Dupuytren's disease (DD) is a superficial fibromatosis of the hand. Although the molecular mechanisms responsible for this disease are unknown, recent studies suggest that beta-catenin may be a key factor involved in fibromatosis. In this study, we analysed the in vivo and in vitro expression levels of beta-catenin in DD, using surgical specimens and primary cell lines. Although no somatic mutations (exon 3) of beta-catenin were detected, Western blot analysis revealed high levels of beta-catenin in diseased palmar fascia, and low to undetectable levels of beta-catenin in patient-matched normal palmar fascia. Immunohistochemistry analysis showed high levels of beta-catenin expression within the disease fascia, as well as cytoplasmic and nuclear accumulations of the protein. Immunoprecipitation of beta-catenin from seven patient lesions showed the protein to be tyrosine phosphorylated. Lastly, Western analysis of three patient-matched (disease and normal fascia) primary cell cultures showed significantly elevated levels of beta-catenin in disease cells cultured in three-dimensional collagen lattices. This is the first extensive in vivo and in vitro characterization of beta-catenin in DD, and the first to suggest that the extracellular matrix may play an important role in modulating beta-catenin stability in DD.

Blotting, Western↗

PubMed2003

Tendon function after replantation: prognostic factors and strategies to enhance total active motion.

The purpose of this study was to determine the important prognostic factors for recovery of tendon function as measured by total active movement (TAM) in patients undergoing digital replantation. More important, the authors wanted to establish which factors may be manipulated to maximize motion. A retrospective review of 48 patients (103 digital rays) who underwent replantation was performed. Average TAM for all digits was 129 deg. Zone 1 and zone 5 injuries had better TAM than injuries in zones 2, 3, and 4, which had TAM values not significantly different from one another. Avulsion injuries fared significantly worse than other mechanisms of injury. TAM values were not affected by age, type of bone fixation, number of arteries repaired, or number of digits injured. Digits with both the profundus and the superficialis tendons repaired had significantly better TAM values relative to one-tendon fingers. Similarly, fingers treated with an "early" mobilization regime also exhibited better movement. Small numbers of injured digits in some groups may have limited our ability to detect significant differences.

Adolescent↗