The effect of simulated elbow arthrodesis on the ability to perform activities of daily living.

The dominant elbow joint of 24 healthy volunteers was immobilized with a functional brace in increments of 20 degrees (6 positions ranging from 30 degrees to 130 degrees ). Average scores were obtained for personal care hygiene tasks (PCH), activity of daily living (ADL), and total functional scores (PCH + ADL) for each elbow flexion position. Functional scores increased with increasing elbow flexion, peaking at 110 degrees and then tapering down. Repeated-measures analysis of variance showed statistical significance, with functional scores improving with increasing elbow flexion for PCH, ADL, and PCH + ADL scores. Further pairwise comparisons for elbow position between 90 degrees and 110 degrees flexion groups demonstrated significant higher mean functional scores for ADL and combined PCH + ADL for the 110 degrees group. The results of this study support a clear advantage in subjects' upper-extremity functional abilities with the elbow immobilized at 110 degrees of flexion when dealing with normal upper-extremity joints. This angle of flexion should be considered in patients undergoing trial immobilization before an elbow arthrodesis.

Reliability of a modified Gartland classification of supracondylar humerus fractures.

Fracture-classification systems are used to recommend treatment and predict outcomes. In this study, a modified Gartland classification system of supracondylar humerus fractures in children was assessed for intraobserver and interobserver variability. Five observers classified radiographs of 50 consecutive children with extension supracondylar humerus fractures on three separate occasions. After a 2-week interval, 90% of fractures were classified the same on both readings, with and intraobserver kappa value of 0.84. After a 36-week interval, 89% of the fractures were classified the same, with a kappa value of 0.81. Interobserver reliability was evaluated by pairwise comparison among observers, resulting in an overall kappa value of 0.74. The reliability of the Gartland classification for supracondylar humerus fractures in children is better than that published for other fracture-classification systems. However, 10% of the time, a second reading by the same observer is different. This makes treatment recommendations based only on fracture type imprecise.

Prospective randomized study of reamed versus unreamed femoral intramedullary nailing: an assessment of procedures.

OBJECTIVE: To determine whether the procedure of unreamed femoral nailing is simpler, faster, and safer than reamed femoral intramedullary nailing. DESIGN: Prospective randomized. SETTING/PARTICIPANTS: One hundred femoral shaft fractures without significant concomitant injuries admitted to an academic Level 1 urban trauma center. INTERVENTION: Stabilization of the femoral shaft fracture using a reamed or unreamed technique. OUTCOME MEASUREMENTS: The surgical time, estimated blood loss, fluoroscopy time, and perioperative complications were prospectively recorded. RESULTS: One hundred patients with 100 femoral shaft fractures were correctly prospectively randomized to the study. Thirty-seven patients received reamed and sixty-three patients received unreamed nails. All nails were interlocked proximally and distally. The average surgical time for the reamed nail group was 138 minutes and for unreamed nail group was 108 minutes (p = 0.012). The estimated blood loss for the reamed nail group was 278 milliliters and for the unreamed nail group 186 milliliters (p = 0.034). Reamed intramedullary nailing required an average of 4.72 minutes, whereas unreamed nailing required 4.29 minutes of fluoroscopy time. Seven perioperative complications occurred in the reamed nail group and eighteen in the unreamed nail group. Two patients in the unreamed group required an early secondary procedure. Iatrogenic comminution of the fracture site occurred during three reamed and six unreamed intramedullary nailings. Reaming of the canal was required before the successful placement of three nails in the unreamed group because of canal/nail diameter mismatch. CONCLUSIONS: Unreamed femoral intramedullary nailing involves fewer steps and is significantly faster with less intraoperative blood loss than reamed intramedullary nailing. The unreamed technique, however, was associated with a higher incidence of perioperative complications, although the difference was not statistically significant (p = 0.5).

A biomechanical comparison of multistrand flexor tendon repairs using an in situ testing model.

An in situ testing model was used to evaluate the performance of zone II flexor tendon repairs and to compare the biomechanical properties of 4-strand repairs with 2- and 6-strand repairs. Fifty digits from human cadaveric hands were mounted in a custom apparatus for in situ tensile testing. Intratendinous metallic markers were placed so that gap formation could be determined by fluoroscopy during tensile testing. Three 4-strand repairs (the 4-strand Kessler, the cruciate, and a locked modification of the cruciate repair) were compared with the 2-strand Kessler and the 6-strand Savage repairs. Ultimate tensile strength, load at 2-, 3-, and 4-mm gap formation, and work of flexion were determined. Work of flexion, while increased for the multistrand repairs, did not show a statistically significant correlation with the number of strands crossing the repair site. The tensile strength of the 6-strand repair was significantly greater than each of the 2- or 4-strand repairs. The tensile strength of all 4-strand repairs was significantly greater than the 2-strand repair. The 6-strand repair and the 2 cruciate repairs demonstrated a statistically increased resistance to gap formation compared with the 2-strand Kessler repair, but notably there was no statistically significant difference in gap resistance between the 2and 4-strand Kessler repairs. This in situ tensiletesting protocol demonstrated that 4- and 6-strand repairs have adequate initial strength to withstand the projected forces of early active motion protocols. Three of the 4 multistrand repairs demonstrated improved gap resistance compared with the 2-strand repair. The presence of the second suture in the Kessler configuration significantly increases its strength but not its gap resistance.

Brace treatment of early infantile tibia vara.

We reviewed 24 children (42 extremities) who had a diagnosis of early infantile tibia vara treated by using a brace. The indication for bracing was either a varus deformity that was not improving by age 18-24 months, or a persistent varus deformity seen in a patient older than 24 months. We prescribed an above-the-knee brace with a free ankle, single medial upright with valgus-producing straps, and either no hinged joint or a locked hinge joint at the knee. The braces were worn during the day and were removed for bedtime. The patients were followed up for an average of 27.2 months (range, 12-72) from the initiation of brace treatment, and the outcome at latest follow-up was determined by using radiographic criteria. Before treatment, 29 extremities were Langenskiöld stage I, II were stage II, and two were stage III. Before treatment, the metaphyseal-diaphyseal angle averaged 16.4 degrees. Forty of the 42 extremities had metaphyseal-diaphyseal angles of > 11 degrees, and 20 were > 16 degrees. Based on our criteria, we rated 29 extremities good, nine fair, and four poor. We conclude that daytime, ambulatory brace treatment may favorably alter the natural history of tibia vara in patients who are younger than 3 years and who have Langenskiöld stage I or II deformity.

The effects of simulated Bier block IVRA on intracompartmental tissue pressure.

BACKGROUND: Intravenous regional anesthesia (IVRA) is a useful anesthetic method for closed reduction of fractures. However, IVRA has been associated with an increased incidence of compartment syndrome when treating tibial shaft fractures. The purpose of this study was to measure changes in anterior leg compartment pressures during simulated IVRA. METHODS: A volunteer study was performed. An indwelling catheter placed in a consistent location between subjects was used to measure tissue pressure. A vinyl leg splint was used for exsanguination followed by thigh tourniquet inflation (300 mmHg). Normal saline (1.5 mL/kg) was injected through the greater saphenous vein (1.0 mL/s). Pressure measurements were obtained before and after tourniquet inflation, at 10 mL increments during saline injection, and intermittently after volume injection with the tourniquet inflated, then deflated. RESULTS: There was no significant difference in tissue pressure before (2.4 +/- 2.2 mmHg) and after (4.3 +/- 3.7 mmHg) tourniquet inflation (P = 0.11). No significant difference in tissue pressure were found as a function of injected volume (P = 0.62), as a function of time following saline injection during tourniquet inflation (P = 0.08), and after tourniquet deflation (P = 0.16). CONCLUSIONS: We conclude that in the normal atraumatic limb, simulated IVRA using normal saline does not increase tissue pressure within the anterior leg compartment.

Resistance of lambda cI translation to antibiotics that inhibit translation initiation.

The lambda cI lysogenic transcript is unusual in having no leader. Expression of a cI-lacZ protein fusion was relatively resistant to kasugamycin and pactamycin, which inhibit translation initiation on transcripts with leaders. Our data imply that there are distinct differences in translation initiation between the two classes of transcripts.

Translation of the prophage lambda cl transcript.

Mutations in rpsB that reduce the levels of the ribosomal protein S2 enhance the translation of cl in lambda lysogens. Two features of the cl transcript are required for enhanced translation: the absence of a leader and the presence of a downstream box, a sequence within the cl coding region that is complementary to the 16S rRNA. 30S ribosomal subunits deficient in S2 form ternary complexes with the cl transcript more efficiently than wild-type subunits. The absence of S2 may change the structure of the 16S rRNA, improving contacts with the cl downstream box.