The reliability of clinical tools with and without ultrasound guidance to measure leg-length inequality

Purpose

To determine and compare the reliability and efficiency of various methods of leg-length measurement.

Methods

A total of 88 leg-lengths were measured among 50 subjects (79%-84% female, mean age = 30-33 years). Leg-lengths were measured in both supine and standing positions using multiple devices, including a tape measure, a LASER distance meter, and diagnostic ultrasound.

Results

All methods of leg-length measurement using the middle of the femoral head as a reference point, identified via ultrasound, demonstrated excellent reliability (intraclass correlation coefficient = 0.95-1.00). Measurements performed in supine, using the anterior superior iliac spine as a reference point, with a tape measure, demonstrated good-to-excellent reliability (intraclass correlation coefficient = 0.86-0.95, standard error of the measurement = 16.1-19.9 cm). Standing measurements using the anterior superior iliac spine as a reference point, using a tape measure, demonstrated fair-to-excellent reliability (intraclass correlation coefficient = 0.71-0.95).

Conclusion

Ultrasound-guided landmark identification appear to be a more reliable method compared to palpation of the anterior superior iliac spine for measurement of leg-length using clinical tools. When coupled with ultrasound guidance, a hand-held LASER distance meter/pitch locator apparatus or a retractable tape measure appears to be acceptable alternatives to a fixed LASER distance meter on a linear actuator for leg-length measurement.

A Comparison of Bioimpedance Spectroscopy or Tape Measure Triggered Compression Intervention in Chronic Breast Cancer Lymphedema Prevention

Background: This study compared rates of progression to chronic breast cancer-related lymphedema (defined as ≥ 10% arm volume change from baseline requiring complex decongestive physiotherapy [CDP]) following an intervention for subclinical lymphedema (S-BCRL) triggered by bioimpedance spectroscopy (BIS) or by tape measurement (TM). Methods and Results: This stratified, randomized, international trial enrolled new breast cancer patients undergoing: mastectomy/partial mastectomy, axillary treatment (dissection, sentinel lymph node biopsy [SLNB] >6 nodes or radiation), radiation therapy (chest wall/breast, supraclavicular fossa), or taxane-based chemotherapy. Following postsurgery eligibility reassessment, centralized, 1:1 randomization to prospective surveillance by BIS or TM occurred. S-BCRL detection triggered a 4-week, 12-hour per day, compression sleeve, and gauntlet intervention. The primary outcome (n = 209), rates of postintervention progression to CDP, was assessed over 3 years. Between June 24, 2014 and September 11, 2018, 1200 patients were enrolled, 963 randomized (BIS n = 482; TM n = 481) and 879 analyzed (BIS n = 442; TM n = 437). Median follow-up was 32.9 months (interquartile range = 22, 35). BIS patients triggered an intervention at a lower rate than TM patients (20.1%, n = 89 vs. 27.5%, n = 120, p = 0.011). Median months to trigger were longer with BIS than TM (9.7; 95% confidence interval [CI], 8.2-12.6 vs. 3.9; 95% CI, 2.8-4.5, p = 0.001). Overall, 14.4% (n = 30) progressed post-intervention, with reduced likelihood for BIS patients than TM patients (7.9%, n = 7 vs. 19.2%, n = 23; relative risk = 0.41; 95% CI, 0.13-0.81; absolute reduction 11.3%; 95% CI, 2.3-20.3; p = 0.016). Conclusions: Compared to TM, BIS provides a more precise identification of patients likely to benefit from an early compression intervention. Clinical Trial Registration number: NCT02167659.

Biogenesis of a Bacteriophage Long Non-Contractile Tail

Siphoviruses are main killers of bacteria. They use a long non-contractile tail to recognize the host cell and to deliver the genome from the viral capsid to the bacterial cytoplasm. Here, we define the molecular organization of the Bacillus subtilis bacteriophage SPP1 ~ 6.8 MDa tail and uncover its biogenesis mechanisms. A complex between gp21 and the tail distal protein (Dit) gp19.1 is assembled first to build the tail cap (gp19.1-gp21Nter) connected by a flexible hinge to the tail fiber (gp21Cter). The tip of the gp21Cter fiber is loosely associated to gp22. The cap provides a platform where tail tube proteins (TTPs) initiate polymerization around the tape measure protein gp18 (TMP), a reaction dependent on the non-structural tail assembly chaperones gp17.5 and gp17.5* (TACs). Gp17.5 is essential for stability of gp18 in the cell. Helical polymerization stops at a precise tube length followed by binding of proteins gp16.1 (TCP) and gp17 (THJP) to build the tail interface for attachment to the capsid portal system. This finding uncovers the function of the extensively conserved gp16.1-homologs in assembly of long tails. All SPP1 tail components, apart from gp22, share homology to conserved proteins whose coding genes' synteny is broadly maintained in siphoviruses. They conceivably represent the minimal essential protein set necessary to build functional long tails. Proteins homologous to SPP1 tail building blocks feature a variety of add-on modules that diversify extensively the tail core structure, expanding its capability to bind host cells and to deliver the viral genome to the bacterial cytoplasm.