Predicting femoral head diameter and lesser trochanter to center of femoral head distance: a novel method of templating hip hemiarthroplasty.

Lesser-trochanter-to-center-of-femoral-head-distance (LTCHD) is commonly used in hip reconstruction. Demographic and radiographic variables were analyzed to predict the LTCHD and femoral head size (FHS). Two hundred twenty six patients after hip arthroplasty and 136 patients after hip hemiarthroplasty (HA) were retrospectively reviewed. Five variables significantly affected the LTCHD and four affected the FHS. For LTCHD, it was relative neck length (RNL), gender, height, race, age and weight. For FHS it was gender, height, age and race. The average predicted LTCHD was within 2.86 mm, and the FHS was 1.63 ± 1.10mm of the intra-operative measurements. By using our regression formulas the LTCHD and FHS can be calculated preoperatively to help improve precision in leg length and offset reconstruction.

Permanent implantation of antibiotic cement over exposed instrumentation eradicates deep spinal infection.

In this case series, we describe an infection treatment protocol involving permanent implantation of antibiotic cement that is effective in eradicating deep infection. Surgical site infection (SSI) is a devastating complication of spine surgery. Unlike the gold-standard two-stage revision in North American hip and knee arthroplasty, there exists no standardized, accepted protocol for the management of deep SSI with instrumentation. Because removal of hardware in an unstable, instrumented spine can result in serious neurologic sequelae, retention of instrumentation with elimination of bacterial colonization on implants is the goal. Using Current Procedural Terminology (CPT) codes, institutional medical records were queried to identify all posterior spinal procedures performed by the senior surgeon from 2008 through 2014. Thirty-four patients were identified as having an implant-associated SSI. Exclusion criteria included: (I) superficial SSI, and (II) those with less than 36 months of follow-up. The study population consisted of ten patients with deep implant-associated SSI who underwent our novel protocol of operative debridement and permanent coating of exposed implants with high-dose antibiotic cement. Postoperative infection presented after an average of 41.4±57.5 days (range, 6.0-207.0 days) from the index procedure. The mean follow-up was 64.4±18.1 months (range, 44.0-98.0 months). At final follow-up, none of the ten patients (0%) in our series had evidence of continued deep infection and none required removal of hardware. Ten of the ten patients (100%) were able to clear infection with a single stage debridement and coating with antibiotic cement. Only 1 of the 10 patients (10%) developed a pseudarthrosis. In conclusion, permanent implantation of antibiotic cement over exposed instrumentation is effective in preserving spinal instrumentation during infection eradication, preventing infection recurrence, and minimizing operative debridements.

Patient-reported outcome scores underestimate the impact of major complications in patients undergoing spine surgery for degenerative conditions.

OBJECTIVE Patient-reported outcomes (PROs) such as the Oswestry Disability Index (ODI) and EuroQol-5D (EQ-5D) are widely used to evaluate treatment outcomes following spine surgery for degenerative conditions. The goal of this study was to use the Charlson Comorbidity Index (CCMI) as a measure of general health status, for comparison with standard PROs. METHODS The authors examined serial CCMI scores, complications, and PROs in 371 patients treated surgically for degenerative lumbar spine conditions who were enrolled in the Quality and Outcomes Database from a single center. The cohort included 152 males (41%) with a mean age of 58.7 years. Patients with no, minor, or major complications were compared at baseline and at 1 year postoperatively. RESULTS Minor complications were observed in 177 patients (48%), and major complications in 34 (9%). There were no significant differences in preoperative ODI, EQ-5D, or CCMI among the 3 groups. At 1 year, there was a significantly greater deterioration in CCMI in the major complication group (1.03) compared with the minor (0.66) and no complication groups (0.44, p < 0.006), but no significant difference in ODI or EQ-5D. CONCLUSIONS Despite equivalent improvements in PROs, patients with major complications actually had greater deterioration in their general health status, as evidenced by worse CCMI scores. Because CCMI is predictive of medical and surgical risk, patients who sustained a major complication now carry a greater likelihood of adverse outcomes with future interventions, including subsequent spine surgery. Although PRO scores are a key metric, they fail to adequately reflect the potential long-term impact of major perioperative complications.

Arthroscopic anterior shoulder stabilization with percutaneous assistance and posteroinferior capsular plication.

To study the technique and clinical outcomes of arthroscopic shoulder stabilization with anterior labral repair and percutaneous posteroinferior capsular plication, we retrospectively reviewed 20 cases. Mean (SD) final postoperative follow-up was 3.4 (0.6) years (range, 2.7-5.1 years). A mean (SD) of 4.9 (0.9) suture anchors (range, 4-7) was used during surgery, with 1.6 (0.7) (range, 1-3) devoted to the posteroinferior plication. There were statistically significant improvements in forward elevation (P = .016) and internal rotation (P = .018) from before surgery to final postoperative follow-up; external rotation did not change (P = .336). Significant improvements (P < .001) were also seen in visual analog scale pain ratings, American Shoulder and Elbow Surgeons survey scores, and Simple Shoulder Test scores. Mean (SD) Rowe instability score at final follow-up was 81.1 (28.9). Eighty-five percent of the patients returned to sport at or above preinjury level, and 70% returned to a degree of athletic physical contact at or above preinjury level. Two cases (10%) were categorized as treatment failures (redislocation). Percutaneously assisted arthroscopic anterior stabilization with posteroinferior capsular plication produces acceptable results, with functional outcomes and redislocation rates comparable to those reported in the literature.

The Pseudomonas aeruginosa ribbon-helix-helix DNA-binding protein AlgZ (AmrZ) controls twitching motility and biogenesis of type IV pili.

Pseudomonas aeruginosa is an opportunistic pathogen that is commonly found in water and soil. In order to colonize surfaces with low water content, P. aeruginosa utilizes a flagellum-independent form of locomotion called twitching motility, which is dependent upon the extension and retraction of type IV pili. This study demonstrates that AlgZ, previously identified as a DNA-binding protein absolutely required for transcription of the alginate biosynthetic operon, is required for twitching motility. AlgZ may be required for the biogenesis or function of type IV pili in twitching motility. Transmission electron microscopy analysis of an algZ deletion in nonmucoid PAO1 failed to detect surface pili. To examine expression and localization of PilA (the major pilin subunit), whole-cell extracts and cell surface pilin preparations were analyzed by Western blotting. While the PilA levels present in whole-cell extracts were similar for wild-type P. aeruginosa and P. aeruginosa with the algZ deletion, the amount of PilA on the surface of the cells was drastically reduced in the algZ mutant. Analysis of algZ and algD mutants indicates that the DNA-binding activity of AlgZ is essential for the regulation of twitching motility and that this is independent of the role of AlgZ in alginate expression. These data show that AlgZ DNA-binding activity is required for twitching motility independently of its role in alginate production and that this involves the surface localization of type IV pili. Given this new role in twitching motility, we propose that algZ (PA3385) be designated amrZ (alginate and motility regulator Z).