Douglas R. Weikert

Intramedullary nailing for impending pathological subtrochanteric fractures

We reviewed ten patients with metastatic carcinoma and impending pathological fractures of the subtrochanteric region of the femur who had prophylactic insertion of the Russell-Taylor reconstruction nail. There were no operative complications or long-term mechanical failures. This reconstruction nail has some technical and biomechanical advantages over other implants and is ideal for the management of such cases.

Geometric properties and the predicted mechanical behavior of adult human clavicles.

An image processing system was used to examine histomorphometric properties of 15 adult male and female human clavicles. Variations in porosity, cross-sectional area, anatomic and principal moments of inertia were assessed at 2.5-5.0% increments along the length of the clavicles. The clavicles biomechanical behavior (axial, flexural, and torsional rigidities and the critical force for buckling) was modeled from these data using beam theory. Over threefold variations in porosity and moments of inertia were found along the length of the s-shaped clavicle--the greatest porosity and moments of inertia were located in the variably shaped sternal and acromial thirds of the bone in contrast to the denser and smaller, more circulatory shaped central third of the bone. Clavicle orientation, as indicated by the direction of greatest resistance to bending (maximum principal moment of inertia), was found to rotate from a primarily cranio-caudal orientation at the sternum to a primarily anterior-posterior orientation at the acromion. Based on cross-sectional geometry, section moduli, and estimates of flexural and torsional rigidity, the clavicle was found to be weakest in the central third of its length. These data concur with the fracture location most commonly reported clinically. Analysis of Euler buckling predicted a minimum critical force for buckling during axial loading of approximately two to three body weights for an average adult. Thus, buckling, or a combination of axial loading and bending or torsional loading, must be considered as possible failure mechanisms for this commonly injured bone.

Precontoured Fixed-Angle Volar Distal Radius Plates: A Comparison of Anatomic Fit

PURPOSE To compare distal radius volar fixed-angle plates for anatomic fit. METHODS Twenty embalmed radii were stripped of soft tissues. The volar lip (watershed line) on the volar distal radius served as a reference line. Seven volar fixed-angle plates were tested (Acumed Acu-loc Standard, Hand Innovations DVRAW and DVRAN, Synthes Juxta-articular [JA], Synthes Extra-articular [EA], Trimed Volar Bearing, Zimmer Volar Lateral Column). Four parameters of anatomic fit were studied: (1) site of best fit; (2) percent plate contact; (3) pin-subchondral bone distance; and (4) extraosseous penetrations. The Wilcoxon signed rank test and Pearsons correlation coefficient were used to compare interobserver plate placement. A Kruskal-Wallis analysis of variance was used to compare percent plate contact and pin-subchondral bone distance across all plates. The Bonferroni correction for multiple comparisons was used to compare pin-subchondral bone distances for all possible plate combinations. RESULTS There was no difference between observers for plate placement. Each plate had a specific site of best fit, and the 7 plates varied widely in best fit location. Percent contact (range, 3% to 6%) between plates was significantly different. Pin-subchondral bone distance across all plates was significantly different. Analysis of all possible plate combinations showed that the Synthes EA pin-subchondral bone distances were significantly different than those of all plates except Zimmer. Amongst the 140 plate insertions, the radiocarpal joint was penetrated in 17, the styloid in 7, (with 6 associated with the DVRAW plate), and the distal radioulnar joint in 9 (all associated with the DVRAW plate). CONCLUSIONS There was considerable variation in ideal plate location among the 7 plates tested. Total contact was minimal for all plates tested. The Synthes EA pin-subchondral bone distance was significantly greater than those of other plates tested. Joint penetration was relatively common, necessitating use of fluoroscopy and proper plate width.

Distal interphalangeal joint arthrodesis comparing tensionband wire and herbert screw: A biomechanical and dimensional analysis

Thirty cadaveric distal interphalangeal joints (15 male and 15 female joints) were prepared with either a Herbert screw or a tension-band wire technique to simulate an arthrodesis. To elucidate mechanical differences between these constructs, the strength of the specimens was determined for three-point anteroposterior and lateral bending and for axial torsion. The Herbert screw demonstrated significantly greater anteroposterior bending strength and greater torsional rigidity when compared to the tension-band wire technique. For dimensional analysis, the height and width of each distal phalanx was measured prior to fixation, 4 mm from the distal tip of the bone (the region that must accommodate the large-diameter threads of the Herbert screw). Results indicated that the mean height of the distal phalanx (3.55 mm) is smaller than the diameter of the screw (3.90 mm). Fracture or thread penetration at the tip of the distal phalanx during screw placement occurred in 25 of the specimens overall and in all the female phalanges, often resulting in stretching or violation of the nail bed. Despite fracture or screw penetration, the Herbert screw appears to offer additional strength that may be clinically important for joint arthrodesis.

Outcomes of Hook of Hamate Fracture Excision in High-Level Amateur Athletes

PURPOSE To determine the overall long-term postoperative clinical and functional results of high-level amateur athletes after hook of hamate excision, based on complications; return to sport; Disabilities of the Arm, Shoulder, and Hand (DASH) score; and a self-reported questionnaire. METHODS We evaluated 11 patients representing 12 cases of hook of hamate excision. All patients were high-level amateur athletes (rising collegiate or collegiate level). We performed a retrospective chart review to elicit information pertaining to the patients injury. We assessed long-term postoperative outcomes with a self-reported questionnaire, the DASH form, and the DASH Sport/Performing Arts Module form. RESULTS All patients successfully returned to full participation in their respective sports an average of 6 weeks after surgery. The average postoperative DASH score was less than 1, and all patients scored a 0 on the DASH Sports form. There was a significant improvement in preoperative pain after surgical intervention. There was no significant difference between preinjury and postoperative performance scores. Finally, every patient was very satisfied with the surgical outcome. There was only 1 postoperative complication in which a patient developed transient ulnar nerve paresthesias, which completely resolved by 6 weeks after surgery. CONCLUSIONS Surgical excision of hook of hamate fractures in high-level amateur athletes allows for successful return to sports participation at preinjury performance levels, achievement of normal function as measured by validated objective outcome measures, significant reduction in pain, and high overall patient satisfaction. We consider surgical excision to be a safe and effective technique to restore normal function and hasten return to play for high-level amateur athletes. TYPE OF STUDY/LEVEL OF EVIDENCE Therapeutic IV.

Splenectomy for end‐stage chronic lymphocytic leukemia

Between February 1980 and December 1985, splenectomies were performed in 13 patients with advanced (Stage III and IV) chronic lymphocytic leukemia (CLL). Patients had advanced disease for a median of 32 months at the time of splenectomy and all were refractory to chemotherapy. All patients were anemic with a median hematocrit of 27.5%; nine patients were thrombocytopenic with a median platelet count of 46,000/μl. There was no surgical mortality and minimal morbidity. Median hematocrit was 35% at 1 month and 6 months postsplenectomy. Median platelet count in previously thrombocytopenic patients was 261,000/μl at 1 month and 177,000/μl at 6 months postsplenectomy. Median survival postsplenectomy in this advanced patient group was 24 months with four patients surviving more than 30 months. Splenectomy is a valuable adjunct to the management of end‐stage CLL.

Driving with an Arm Immobilized in a Splint: A Randomized Higher-Order Crossover Trial

BACKGROUND The aim of this study was to determine whether immobilization of an arm has detrimental effects on driving performance. METHODS Thirty-six healthy officers-in-training were assigned a sequence of fiberglass splints (left and right-sided above-the-elbow thumb spica and below-the-elbow splints) with use of a randomized higher-order crossover design. Runs were scored on a cone-marked driving course used for officer certification with predetermined passing requirements. Driving time, the number of cones hit per course section, and the cone-adjusted total time (a five-second penalty per hit cone) were recorded. A linear mixed-effect model with random environmental and learning effects for cone-adjusted time analysis was used. Participants rated perceived driving difficulty and safety with each splint, and ratings were compared with the Wilcoxon signed-rank test. RESULTS Thirty participants completed the entire set of runs. Analysis of total cone-adjusted time revealed a significant performance decrease with the left arm in an above-the-elbow thumb spica splint (average, 22.2 seconds; p < 0.001) and with the left arm in a below-the-elbow splint (average, 16.2; p = 0.007). Analysis of forward-only course sections revealed poorer performance trends with all splints, with the worst performance with the left arm in an above-the-elbow thumb spica splint. Driving with the left arm in an above-the-elbow thumb spica splint had the highest perceived difficulty (median, 8.0) and lowest perceived safety (median, 3.0). CONCLUSIONS Driving performance as measured with a standardized track and scoring system was significantly degraded with splint immobilization of the left arm. Further studies are required to determine the effect of arm immobilization on normal driving conditions.

Radiographic Outcomes of Volar Locked Plating for Distal Radius Fractures

PURPOSE To assess the ability of volar locked plating to achieve and maintain normal radiographic parameters for articular stepoff, volar tilt, radial inclination, ulnar variance, and radial height in distal radius fractures. METHODS We performed a retrospective review of 185 distal radius fractures that underwent volar locked plating with a single plate design over a 5-year period. We reviewed radiographs and recorded measurements for volar tilt, radial inclination, ulnar variance, radial height, and articular stepoff. We used logistic regression to determine the association between return to radiographic standard norms and fracture type. RESULTS At the first and final postoperative follow-up visits, we observed articular congruence less than 2 mm in 92% of fractures at both times. Normal volar tilt (11°) was restored in 46% at the first follow-up and 48% at the final one. Radial inclination (22°) was achieved in 44% at the first follow-up and 43% at the final one, and ulnar variance (01 ± 2 mm) was achieved in 53% at the first follow-up and 53% at the final one. In addition, radial height (14 ± 1mm) was restored in 14% at the first follow-up and 12% at the final one. More complex, intra-articular fractures (AO class B and C and Frykman types 3, 4, 7, and 8) were less likely to be restored to normal radiographic parameters. However, because of the small sample size for some fracture types, it was difficult to discover significant associations between fracture type and radiographic outcome. CONCLUSIONS Volar locked plating for distal radius fractures achieved articular stepoff less than 2 mm in most fractures but only restored and maintained normal radiographic measurements for volar tilt, radial inclination, and ulnar variance in 50% of fractures. The ability of volar locked plating to restore and maintain ulnar variance and volar tilt decreased with more complex intra-articular fracture types. TYPE OF STUDY/LEVEL OF EVIDENCE Therapeutic IV.

Upper Extremity Myonecrosis Caused by Edwardsiella Tarda Resulting in Transhumeral Amputation: Case Report

Necrotizing soft tissue infections are rapidly progressive infections with a high rate of mortality. One type of necrotizing soft tissue infection is caused by marine gram-negative bacteria and commonly occurs in immunocompromised hosts. These types of infections are more common in patients with chronic liver disease, possibly because of impaired iron metabolism. We present the case of a rapidly progressive necrotizing soft tissue infection caused by Edwardsiella tarda, a marine gram-negative pathogen common in catfish. Few extraintestinal infections of E tarda have been described previously. Our patient had hepatitis C and was exposed to the bacteria by a puncture injury from a wild catfish. His infection required multiple debridements and ultimately required a transhumeral amputation for local control of the infection.

Clostridium septicum myonecrosis complicating diarrhea-associated hemolytic uremic syndrome

We report the case of a 19-month-old male child with diarrhea-associated hemolytic uremic syndrome (HUS) who developed swelling of the right arm at the site of a peripherally inserted central venous catheter (PICC), fever, and later, ecchymosis. Wound cultures at the time of surgical debridement grew Clostridium septicum. The child subsequently required amputation of the right arm and prolonged therapy with parenteral penicillin and clindamycin. Clostridium septicum infections in children with HUS have been associated with a high rate of mortality. Along with colon cancer, diarrhea-associated HUS comprises a clinical entity which appears to predispose to atraumatic C. septicum infection, where acidic and anaerobic conditions in the diseased colon favor C. septicum invasion. Though not well recognized among pediatric nephrologists, C. septicum infection constitutes a severe, albeit rare, complication of diarrhea-associated HUS, but one in which a high index of suspicion is warranted as aggressive surgical and antibiotic therapy may be life-saving.