Nicholas B. Vedder

Factors affecting functional outcome of displaced intra-articular distal radius fractures

Open reduction and internal fixation is often required in comminuted, displaced intra-articular fractures of the distal radius when closed manipulation has failed to restore articular congruity. Results of surgical stabilization and articular reconstruction of these injuries are reviewed in this retrospective study of 49 patients with 52 displaced, intra-articular distal radius fractures. Forty-three patients with a mean age of 37 years (range, 17-79 years) were available for evaluation. The mean follow-up time was 38 months (range, 22-69 months). When rated by the system proposed by the Association for the Study of Internal Fixation (ASIF), 19 were ASIF type C2 and 21 were ASIF type C3. An injury score system based on the initial injury x-ray films was used to classify severely comminuted intra-articular fractures and to identify those associated with carpal injury. Postoperative fracture alignment, articular congruity, and radial length were significantly improved following surgery. Grip strength averaged 69 +/- 22% of the contralateral side, and range of motion averaged 75 +/- 18% of the contralateral side after surgery. A combined outcome rating system that included grip strength, range of motion, and pain relief averaged 76 +/- 19% of the contralateral side. Using regression analysis, a significant decrease was found in the combined rating with more severe fracture patterns as defined by the ASIF system, Malone classification, and the injury score system. The injury score system presented here and, in particular, the number of fracture fragments correlated most closely with the outcome of all classification systems examined. Operative treatment of complex distal radius fractures with reconstruction of articular congruity with internal fixation and/or external fixation can significantly improve functional outcome. The degree to which articular step-off, gap between fragments, and radial shortening are improved by surgery is strongly correlated with improved outcome, even when the results are corrected for severity of initial injury, whereas correction of radial tilt or dorsal tilt did not correlate with improved outcome.

A monoclonal antibody to the adherence-promoting leukocyte glycoprotein, CD18, reduces organ injury and improves survival from hemorrhagic shock and resuscitation in rabbits.

Leukocytes have been shown to play an important role in the development of isolated organ injury after experimental ischemia and reperfusion. To examine the role of leukocytes in generalized ischemia-reperfusion injury we used the MAb 60.3 (directed to the human leukocyte adherence glycoprotein, CD18) to block leukocyte adherence functions in a rabbit model of hemorrhagic shock and resuscitation. In control animals subjected to 1 h of shock (mean blood pressure 45 torr and mean cardiac output 30% of baseline) followed by resuscitation, only 29% survived 5 d. All had gross and histologic evidence of injury to lungs, liver, and gastrointestinal mucosa. In contrast, 100% of the MAb 60.3-treated animals survived 5 d (P less than 0.01) and organ injury was absent or markedly attenuated. The control animals also had a persistent acidosis, lost more weight, and had evidence of continued gastrointestinal bleeding in contrast to MAb 60.3-treated animals. We conclude that increased leukocyte adhesiveness plays an important role in the development of multiple organ injury and death after generalized ischemia-reperfusion and that this injury may be significantly reduced by blocking leukocyte adherence functions with the MAb 60.3.

Outcome after hemorrhagic shock in trauma patients.

BACKGROUND It is essential to identify patients at high risk of death and complications for future studies of interventions to decrease reperfusion injury. METHODS We conducted an inception cohort study at a Level I trauma center to determine the rates and predictors of death, organ failure, and infection in trauma patients with systolic blood pressure < or = 90 mm Hg in the field or in the emergency department. RESULTS Among the 208 patients with hemorrhagic shock (blood pressure < or = 90 mm Hg), 31% died within 2 hours of emergency department arrival, 12% died between 2 and 24 hours, 11% died after 24 hours, and 46% survived. Among those who survived > or = 24 hours, 39% developed infection and 24% developed organ failure. Increasing volume of crystalloid in the first 24 hours was strongly associated with increased mortality (p = 0.00001). CONCLUSION Hemorrhage-induced hypotension in trauma patients is predictive of high mortality (54%) and morbidity. The requirement for large volumes of crystalloid was associated with increased mortality.

Anti-P-selectin monoclonal antibody attenuates reperfusion injury to the rabbit ear.

Neutrophil adherence and/or aggregation has been implicated in ischemia reperfusion injuries. We examined the role of P-selectin in PMN-mediated injury after reperfusion of the rabbit ear. The ear was partially amputated, and then reattached leaving the central artery and vein intact. To induce ischemia the central artery was then occluded. Treatment was at reperfusion with either saline or one of two murine P-selectin mAbs, designated PB1.3 and PNB1.6 mAb PB1.3 cross-reacts with rabbit P-selectin and prevents histamine-induced leukocyte rolling, whereas PNB1.6 does not. Using a peroxidase-antiperoxidase system P-selectin was detected in the ischemic ear, but not in the nonischemic ear. Ear volume increased to 5.3 times baseline in the saline-treated animals (n = 8), 6.6 times baseline in the nonblocking mAb PNB1.6-treated animals (n = 2), and 3.7 times baseline in the blocking mAb PB1.3-treated animals (n = 8). Estimated tissue necrosis of the combined saline- and PNB1.6-treated animals was 46 vs. 2.7% for the mAb PB1.3-treated animals. We conclude that: (a) P-selectin is expressed in ischemia reperfusion; (b) P-selectin participates in PMN-endothelial cell interactions in ischemia reperfusion; and (c) inhibiting P-selectin adhesion significantly reduces reperfusion injury.

Intrafocal (Kapandji) pinning of distal radius fractures with and without external fixation.

Seventy-three patients were treated with either intrafocal pinning (Kapandji technique) alone or in combination with external fixation between 1988 and 1993 for extra-articular fractures of the distal radius (with or without a nondisplaced extension into the radiocarpal articular surface) with inadequate alignment after initial closed reduction. Sixty-one patients were available for follow-up examination at an average of 34 months (range, 24-71 months). The average age was 52 years (range, 16-84 years). Thirty-three of the patients were female. The patients all had dorsally displaced extra-articular fractures, although 56% had a nondisplaced extension of the fracture into the radiocarpal joint and 46% had a nondisplaced fracture extending into the distal radioulnar joint. The patients were separated into groups based on age, degree of comminution, and whether external fixation was also used. In the older patients, range of motion, grip strength, and pain relief were significantly better when external fixation was used, even when only 1 cortex of the radius demonstrated comminution. In the younger patients, good results in terms of range of motion, grip strength, and pain relief were obtained when percutaneous intrafocal pins were used alone in patients with comminution of only 1 surface of the radius (<50% of the metaphyseal diameter). When > or = 2 sides of the radial metaphysis were comminuted, the patients with external fixation had better results than those without external fixation. Although the correction of palmar tilt and radial tilt did result in better functional results, the restoration of radial length had the most significant effect on range of motion and grip strength.

Reduction of burn injury by inhibiting CD18-mediated leukocyte adherence in rabbits.

The progressive nature of dermal ischemia and subsequent tissue destruction within the “zone of stasis” is a central focus in burn research. To examine the role of neutrophils and neutrophil adherence within the zone of stasis, we utilized the monoclonal antibody (MAb) 60.3, directed to the human leukocyte adherence glycoprotein CD18 to block neutrophil adherence to endothelium and intravascular aggregation in a rabbit model of partial-thickness burn. Burns were created by applying an 80°C brass template to the dorsal rabbit skin for 5 or 10 seconds. Animals treated with MAb 60.3 thirty minutes following a 5-second burn had less edema, thinner eschar, and earlier elevation of the eschar than control animals. Histologic analysis revealed an eightfold increase in live hair follicles (p < 0.05) and 43 percent greater reepithelialization at 8 days (p < 0.05) and a 15 percent reduction in burn surface area at 24 hours (p < 0.0001) in the antibody-treated group. There was no significant difference between treatment and control groups exposed to 10-second burns. We conclude that neutrophils and increased neutrophil adherence play important roles in the progressive tissue destruction within the zone of stasis in burns. Furthermore, moderate burn injury may be significantly attenuated by blocking neutrophil adherence functions with a CD18 MAb. (Plast. Reconstr. Surg. 93: 1473, 1994.)

Failure of cast immobilization for thumb ulnar collateral ligament avulsion fractures

To determine if small avulsion fractures of the thumb ulnar collateral ligament (UCL) with minimal (< or = 2.0 mm) displacement can successfully be treated by cast immobilization, the authors reviewed 9 patients with minimally displaced fractures initially treated by casting. Despite immobilization within an average of 2 days of the initial injury (range, 0-6 days), a minimum of 6 weeks of immobilization in a cast, and adequate rehabilitation, all 9 patients had persistent thumb pain, especially with activities requiring strong pinch. After undergoing open reduction and internal fixation, the patients had relief of thumb pain and pinch strength improved from 36% of the contralateral side to 89% (p < .01). Grip strength increased from 77% to 93% (p < .05), but the ranges of motion of the thumb metacarpophalangeal and interphalangeal joints were not significantly altered. Minimally displaced UCL avulsion fractures frequently have significant rotation that prevents successful fracture healing even with prompt cast immobilization.

Improved survival rates of random flaps in rabbits with a monoclonal antibody that blocks leukocyte adherence.

To examine the role of neutrophil adhesiveness in the tissue injury involving the ischemic “at risk” area of random flaps, we used the monoclonal antibody 60.3, which binds selectively to the primary neutrophil adherence-mediating glycoprotein CD18 in a random cutaneous flap model. Control animals that had flaps elevated and replaced (n = 12) had a mean distal necrosis of 31.9 ± 9.3 percent of the total flap surface area. Treatment with monoclonal antibody 60.3 (n = 12) reduced distal necrosis to 10.6 ± 7.5 percent (p < 0.005). Inhibiting inosculation by interposing a thin silicone sheet decreased distal flap survival; however, the protective effect of monoclonal antibody 60.3 on improving flap survival was unchanged. Control isolated flaps (n = 13) had a mean distal necrosis of 49.0 ± 15.5 percent compared with 22.2 ± 5.6 percent for the antibody-treated (n = 8) isolated flaps (p < 0.05). We conclude that increased neutrophil adhesiveness plays an important role in the tissue injury involving the ischemic “at risk” area of random flaps and that transient, specific inhibition of leukocyte adherence by monoclonal antibody 60.3 improves the distal survival of random flaps in this model. Moreover, we conclude that “graft inosculation” contributes to “flap” survival in this model; however, conclusions regarding the effect of treatment are not altered by blocking inosculation. (Plast. Reconstr. Surg. 93: 1035, 1994.)

Leukocyte—Endothelial Cell Interactions in Ischemia‐Reperfusion Injury

Neutrophils (PMNs) have been implicated as the cause of tissue injury leading to organ dysfunction and organ failure following a variety of insults. One of the first suggestions of a potential for injuries of this type was made by Metchnikoff in 1887 when he suggested that tissue injury could result during normal phag0cytosis.l Subsequently, several studies have demonstrated the ability of stimulated PMNs to cause injury to endothelial cells in vitr~.~-’ In some of these studies it was shown that adherence of PMNs to the endothelial cells with the formation of a protected microenvironment was necessary before the endothelial cells were The leukocyte-endothelial cell adhesion results from specific molecular interactions between molecules on the surface of leukocytes and their counter-receptors on the endothelial cells. The role of leukocytes in organ injury in vivo has been demonstrated by reducing the number of circulating PMNs with chemotherapeutic agents. PMN depletion reduced focal ischemia-reperfusion injury to the heart,8.y gut,lo as well as the generalized ischemia-reperfusion injury resulting from resuscitation from hemorrhagic shock.10*13

Soft Tissue Reconstruction of the Hand

There are a number of insults that can compromise the soft tissue envelope of the hand. Soft tissue reconstruction seeks to restore both the aesthetic appearance and the function of the hand. The purpose of this review is to describe recent advances in hand soft tissue reconstruction. Skin grafts and skin substitutes both are useful reconstructive options for certain defects. Digital coverage continues to be subject to refinements that lead to better reconstructions. Flaps based on donor sites from the dorsal metacarpal artery system are finding continually expanding uses in hand reconstruction. Traditional notions of forearm-based donor tissue are being challenged, leading to better hand reconstructions with less donor morbidity. Finally, improvements in free tissue transfer enable the expansion of reconstructive possibilities available for hand coverage.