How are peri-implant fractures below short versus long cephalomedullary nails different?

BACKGROUND: Cephalomedullary nails are a commonly used implant for the treatment of many pertrochanteric femur fractures and are available in short and long configurations. There is no consensus on ideal nail length. Relative advantages can be ascribed to short and long intramedullary nails, yet both implant styles share the potentially devastating complication of peri-implant fracture. Determining the clinical sequelae after fractures below nails of different lengths would provide valuable information for surgeons choosing between short or long nails. Thus, the purpose of the study was to compare injury patterns and treatment outcomes following peri-implant fractures below short or long cephalomedullary nails. METHODS: This was a multicenter retrospective cohort study that identified 33 patients referred for treatment of peri-implant fractures below short and long cephalomedullary nails (n = 19 short, n = 14 long). We compared fracture pattern, treatment strategy, complications, and outcomes between these two groups. RESULTS: Short nails were associated with more diaphyseal fractures (odds ratio [OR] 13.75, CI 2.2-57.9, p 0.002), which were treated more commonly with revision intramedullary nailing (OR, infinity; p 0.01), while long nails were associated with distal metaphyseal fractures (OR 13.75, CI 2.2-57.9, p 0.002), which were treated with plate and screw fixation (p 0.002). After peri-implant fracture, there were no differences in blood loss, operative time, weight bearing status, or complication rates based on the length of the initial nail. In patients treated with revision nailing, there was greater estimated blood loss (EBL, median 300 cc, interquartile range [IQR] 250-1200 vs median 200 cc, IQR 100-300, p 0.03), blood product utilization and complication rates (OR 11.1, CI 1.1-135.7, p 0.03), but a trend toward unrestricted post-operative weight-bearing compared to patients treated with plate and screw constructs. CONCLUSION: Understanding fracture patterns and patient outcomes after fractures below nails of different lengths will help surgeons make more informed implant choices when treating intertrochanteric hip fractures. Revision to a long nail for the treatment of fractures at the tip of a short nail may be associated with increased patient morbidity.

Fracture Fixation Using Shape-Memory (Ninitol) Staples.

Shape-memory alloy (SMA) staples are a recent innovation in fracture fixation. These staples have inherent compressive properties that create a stable fracture environment that promotes primary bone healing. They have been used successfully for osteotomies, arthrodesis, and fracture fixation. Understanding where SMA staple compression can be optimized and using proper indications are important for obtaining consistent success and minimizing failures. SMA staples are not a substitute for lag screw fixation or traditional plate and screw constructs.

Survey of peptide quantification methods and comparison of their reproducibility: A case study using oxytocin.

USP's peptide reference standards content is typically determined using an HPLC assay against an external standard for which the purity was determined by a mass balance approach. To explore the use of other analytical methods, the USP Biologics Department conducted a multi-laboratory collaborative study. The study determined the inter-laboratory variability for peptide quantitation using the following methods: HPLC assay, quantitative nuclear magnetic resonance (qNMR) spectroscopy, or amino acid analysis (AAA). The three methods were compared with regard to their suitability for quantitation of the nonapeptide oxytocin. In this study, the HPLC assay method using the same peptide bulk material as the standard showed the lowest inter-lab variability. The coefficient of variation (%CV) was calculated without counting the uncertainty associated with the purity assignment of the standard with mass balance. The proton qNMR method is a direct measurement of the peptide against an internal standard, which is not difficult to perform under common laboratory conditions. Because of the simpler operation and shorter analytical time, qNMR as a primary method for peptide reference standard value assignment deserves further exploration.

Internal Fixation of Osteoporotic Bone.

Osteoporosis is one of the costliest conditions managed by orthopaedic surgeons. This condition, which is characterized by decreased bone density and thinning of cortical bone, is strongly influenced by complex signaling in both the hormonal and mechanical environments. Osteoporosis cannot be cured; instead, it can only be managed to decrease patient morbidity. Current pharmacologic treatments are aimed at minimizing bone turnover and have substantial side effects. Therefore, much work remains to find safer and more effective agents to restore bone density. In addition to the high incidence of fracture in elderly patients, many of the traditional fixation constructs used for repair of these fractures are not suitable for use in osteoporotic bone. Increased use of fixed-angle locking plates, intramedullary devices, and bone substitutes has greatly improved outcomes in these patients.

Computer-assisted navigation for intramedullary nail fixation of intertrochanteric femur fractures: A randomized, controlled trial.

INTRODUCTION: Lag screw cutout is one of the most commonly reported complications following intramedullary nail fixation of intertrochanteric femur fractures. However, its occurrence can be minimized by a well-positioned implant, with a short Tip-to-Apex Distance (TAD). Computer-assisted navigation systems provide surgeons with the ability to track screw placement in real-time. This could allow for improved lag screw placement and potentially reduce radiation exposure to the patient and surgeon. METHODS: Between Oct 2014 and Jan 2016, patients with intertrochanteric femur fractures being treated with intramedullary nail fixation by one of three fellowship-trained orthopaedic traumatologists were enrolled. Inclusion criteria were low-energy mechanism of injury and fracture class 31-A1/A2. Open fractures and patients with multiple injuries to the lower extremity were excluded. Patients were randomly assigned to computer-assisted navigation or a conventional fluoroscopic technique for lag screw placement. The primary outcomes were TAD, measured by postoperative anteroposterior and lateral x-rays by an independent reviewer, and radiation exposure measured in seconds of fluoroscopy time. Surgical time was also recorded. RESULTS: 50 patients were randomized, 26 to the computer-assisted navigation group and 24 to the control group. The mean manually-measured TAD in the computer-assisted navigation group was 14.1mm±3.2 and in the control group was 14.9mm±3.0 (p=0.394). There was no difference between groups in total radiation time (navigation: 58.8 s±23.6, control: 56.5 s±28.5, p=0.337) or radiation time during lag screw placement (navigation: 19.4 s±8.8, control: 18.8 s±8.0, p=0.522). The surgical time was significantly longer in the computer-assisted navigation group with a mean surgical time of 45.8min±9.8 compared to 38.4min±9.3 in the control group (p=0.009). CONCLUSIONS: Computer-assisted navigation consistently produced excellent TADs, however it was not significantly better than conventional methods when done by fellowship-trained orthopaedic traumatologists. Surgeons with a lower volume trauma practice could potentially benefit from computer-assisted navigation to obtain better TAD.

Renal and Hepatic Function in Hypercholesterolemic Rats Fed Jamaican Bitter Yam (Dioscorea polygonoides).

BACKGROUND: We reported that Jamaican bitter yam (Dioscorea polygonoides) has antilipemic potential in rats; however there is limited data on the toxicological profile of the yam. We therefore investigated the effects of bitter yam consumption for 6 or 12 weeks on renal and hepatic function in rats fed a high (4%) cholesterol diet. METHODS: Twenty four rats were divided into six groups (n = 4); three of which were used for each investigation (6 or 12 weeks). One group was administered 4% cholesterol diet, while the yam group had the cholesterol diet supplemented with 5% bitter yam. The control group was fed standard rat chow. Liver and kidney function tests were performed on serum, liver and kidney. Histological studies were conducted on liver samples. Acute toxicity tests were performed in rats and mice administered a single high dose of bitter yam (10 g/kg). RESULTS: Activities of liver and kidney AST and ALT differed (p ≤ .02) between control rats and those fed cholesterol with bitter yam for 12 weeks. Albumin to globulin ratio was reduced (p = .03) in rats fed cholesterol with bitter yam for 6 weeks as compared to the control group. Serum urea concentration was higher (p < .05) in rats fed bitter yam as compared to normal chow for 6 weeks. The cholesterol diet caused extensive fat deposition in liver cells; however this was inhibited by co-administration of bitter yam. CONCLUSION: Long-term administration of Jamaican bitter yam may induce slight changes in renal and hepatic functions.

Short versus long intramedullary nails for treatment of intertrochanteric femur fractures (OTA 31-A1 and A2).

OBJECTIVES: The purpose of this study was to compare blood loss and operative times associated with long versus short intramedullary nails for intertrochanteric fracture fixation and rate of periprosthetic fracture. DESIGN: A retrospective study. SETTING: Level 1 trauma center. PATIENTS: One hundred ninety-four patients with an intertrochanteric fracture (AO/OTA class 31-A1 and A2) and low-energy mechanism of injury treated by 1 of 4 fellowship-trained orthopaedic traumatologists. INTERVENTION: Short versus long intramedullary nail. METHODS: Medical records were reviewed for age, gender, estimated blood loss (EBL), transfusion rate, operative time, length of stay, and incidence of periprosthetic fracture. Variables were statistically compared between long and short intramedullary nails, with statistical significance at P < 0.05. RESULTS: The average EBL (135.5 ± 91.9 mL) and transfusion rate (57.1%) for long nails were found to be significantly greater (P = 0.002) than the EBL (92.6 ± 47.2 mL) and transfusion rate (40.2%) for short nails. Average operative time was also found to be significantly greater (P < 0.001) for long (56.8 ± 19.4 minutes) than for short (44.0 ± 10.7 minutes) intramedullary nail procedures. The overall incidence of periprosthetic fracture was 0.5%, one patient with initial treatment of a long intramedullary nail. CONCLUSIONS: Statistically significant lower operative time, EBL, and transfusion rate were found in this study for short intramedullary nails. There were no differences seen in length of stay or periprosthetic fracture. The incidence of periprosthetic fracture was very low in both cohorts. Further study with greater statistical power is needed. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.