The effect of surgeon-controlled variables on construct stiffness in lateral locked plating of distal femoral fractures.

BACKGROUND: Nonunion following treatment of supracondylar femur fractures with lateral locked plates (LLP) has been reported to be as high as 21 %. Implant related and surgeon-controlled variables have been postulated to contribute to nonunion by modulating fracture-fixation construct stiffness. The purpose of this study is to evaluate the effect of surgeon-controlled factors on stiffness when treating supracondylar femur fractures with LLPs: 1. Does plate length affect construct stiffness given the same plate material, fracture working length and type of screws? 2. Does screw type (bicortical locking versus bicortical nonlocking or unicortical locking) and number of screws affect construct stiffness given the same material, fracture working length, and plate length? 3. Does fracture working length affect construct stiffness given the same plate material, length and type of screws? 4. Does plate material (titanium versus stainless steel) affect construct stiffness given the same fracture working length, plate length, type and number of screws? METHODS: Mechanical study of simulated supracondylar femur fractures treated with LLPs of varying lengths, screw types, fractureworking lenghts, and plate/screw material. Overall construct stiffness was evaluated using an Instron hydraulic testing apparatus. RESULTS: Stiffness was 15 % higher comparing 13-hole to the 5-hole plates (995 N/mm849N vs. /mm, p = 0.003). The use of bicortical nonlocking screws decreased overall construct stiffness by 18 % compared to bicortical locking screws (808 N/mm vs. 995 N/mm, p = 0.0001). The type of screw (unicortical locking vs. bicortical locking) and the number of screws in the diaphysis (3 vs. 10) did not appear to significantly influence construct stiffness (p = 0.76, p = 0.24). Similarly, fracture working length (5.4 cm vs. 9.4 cm, p = 0.24), and implant type (titanium vs. stainless steel, p = 0.12) did also not appear to effect stiffness. DISCUSSION: Using shorter plates and using bicortical nonlocking screws (vs. bicortical locking screws) reduced overall construct stiffness. Using more screws, using unicortical locking screws, increasing fracture working length and varying plate material (titanium vs. stainless steel) does not appear to significantly alter construct stiffness. Surgeons can adjust plate length and screw types to affect overall fracture-fixation construct stiffness; however, the optimal stiffness to promote healing remains unknown.

Direct electromagnetic coupling for non-invasive measurements of stability in simulated fracture healing.

Diagnostic monitoring and prediction of bone fracture healing is critical for the detection of delayed union or non-union and provides the requisite information as to whether therapeutic intervention or timely revision are warranted. A promising approach to monitor fracture healing is to measure the mechanical load-sharing between the healing callus and the implanted hardware used for internal fixation. The objectives of this study were to evaluate a non-invasive measurement system in which an antenna electromagnetically couples with the implanted hardware to sense deflections of the hardware due to an applied load and to investigate the efficacy of the system to detect changes in mechanical load-sharing in an ex vivo fracture healing model. The measurement system was applied to ovine metatarsal bones treated with osteotomies, resulting in four different levels of bone stability which simulated various degrees of fracture healing. Computational finite element simulations supplemented these ex vivo experiments to compare the osteotomy model of fracture healing to a more clinically applicable callus stiffening model of healing. In the ex vivo experiments, the electromagnetic coupling system detected significant differences between the four simulated degrees of healing with good repeatability. Computational simulations indicated that the experimental model of fracture healing provided a good surrogate for studying healing during the early time period as the callus stiffness is increasing as well as when diagnostic monitoring of the healing process is most critical. Based upon the data reported herein, the direct electromagnetic coupling method holds strong potential for clinical assessments and predictions of fracture healing. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Occult internal iliac arterial injury identified during open reduction internal fixation of an acetabular fracture: a report of two cases.

We present two cases of occult internal iliac arterial injury identified during operative reduction of a widely displaced posterior column posterior wall acetabular fracture. This complication was not recognised until reduction of the column fracture. There were no preoperative signs or symptoms indicative of a vascular injury. These cases emphasise the heightened awareness one must have when treating widely displaced posterior column fractures of the acetabulum, especially those fractures with extension into the greater sciatic notch, as previously formed clot can become dislodged and hemostasis lost. We also present management options when this complication occurs. We believe any surgeon treating acetabular fractures should be aware of this serious and potentially fatal complication.

Operative versus nonoperative treatment of displaced proximal humeral physeal fractures: a matched cohort.

BACKGROUND: Displaced proximal humeral physeal fractures (PHPF) are rare injuries. Because of the lack of comparative studies, treatment has historically been based on surgeon preference. The purpose of this study was to compare treatment outcomes among skeletally immature patients who underwent operative versus nonoperative treatment for Neer-Horwitz (NH) III or IV PHPF. METHODS: Skeletally immature patients who underwent treatment for a displaced PHPF from 2003 to 2012 were identified. Eligible subjects were invited to complete a validated shoulder outcome instrument (QuickDASH) and a phone survey. A propensity score matching approach was utilized to match subjects who underwent operative treatment to subjects who underwent nonoperative treatment on the basis of age at injury and NH classification. RESULTS: Seventy patients were identified with a NH III or IV PHPF, of whom 32 subjects completed the study. There was also no difference (P=0.5637) in the proportion of subjects who developed a less than desirable treatment outcome in operative group (57.14%, 4/7) as compared with the nonoperative group (42.86%, 3/7). There was also no difference (P=0.5637) in the proportion of subjects who developed a less than desirable treatment outcome in operative group (57.14%, 4/7) as compared with the nonoperative group. Differences in rate of return to preinjury level of activity (P>0.9999), or cosmetic appearance scores (P>0.999) were not significantly different. QuickDASH scores were 1.9 points (95% CI, 3.0-6.9; P=0.3699) higher overall in the nonoperative group as opposed to the operative group. A less than desirable treatment outcome was noted in 4/23 (17.4%) subjects who underwent nonoperative treatment. Subgroup analysis of the nonoperative cases showed that, for every 1 year increase in age at initial injury, the odds of less than desirable outcome increased by a factor of 3.81 (95% CI, 1.31-21.0). CONCLUSIONS: In a matched cohort of patients with proximal humerus physeal fractures, there was no difference in occurrence of complications, rate of return to activity, or cosmetic satisfaction. Functional outcomes were also nonsignificant, but tended to be higher among fractures that underwent nonoperative treatment. Among nonoperatively treated fractures, less than desirable outcomes were more common in older patients, particularly those older than 12 years of age. LEVEL OF EVIDENCE: Level III-therapeutic.

Analysis of usage and associated cost of external fixators at an urban level 1 trauma centre.

OBJECTIVE: To determine the usage, indication, duration, and cost associated with external fixation usage. Additionally, to show the significant cost associated with external fixator use and reinvigorate discussions on external fixator reuse. DESIGN, SETTING, AND PATIENTS: A retrospective review of a prospectively gathered trauma database was undertaken to identify all patients treated with external fixation frames for pelvic and lower extremity injuries between September 2007 and July 2010. MAIN OUTCOME AND MEASURES: We noted the indications for frame use, and we determined the average duration of external fixation for each indication. The cost of each frame was calculated from implant records. RESULTS: 341 lower extremity and pelvic fractures were treated with external fixation frames during the study period. Of these, 92% were used as temporary external fixation. The average duration of temporary external fixation was 10.5 days. The cost of external fixation frame components was $670,805 per year. The average cost per external fixation frame was $5900. CONCLUSIONS: The majority of external fixators are intended as temporary frames, in place for a limited period of time prior to definitive fixation of skeletal injuries. As such, most frames are not intended to withstand physiologic loads, nor are they expected provide a precise maintenance of reduction. Given the considerable expense associated with external fixation frame components, the practice of purchasing external fixation frame components as disposable "single-use" items appears to be somewhat wasteful. LEVEL OF EVIDENCE: Level II.

MR-compatible antibiotic interlocked nail fabrication for the management of long bone infections: first case report of a new technique.

Successful management of intramedullary long bone osteomyelitis remains a challenge for both surgeons and patients. Patients are often immune-compromised and have endured multiple surgeries. Treatment principles include antibiotic administration (systemically +/- locally), surgical debridement of the infection site and stabilization. Since their description in 2002, antibiotic coated nails have become part of the armamentarium for the treatment of osteomyelitis allowing both local elution of antibiotics and stabilization of a debrided long bone. Limitations to their utilization have remained, in part from the technical difficulty of fabrication and MRI artifacts. We describe a new surgical technique of fabrication that has the advantages of being simple, reproducible, with an end product free of MRI artifacts.

Prophylactic antibiotics in open fractures: a pilot randomized clinical safety study.

OBJECTIVE: To develop preliminary data on Staphylococcus aureus colonization and surgical site infections (SSIs) in patients with open fractures who received standard antibiotic prophylaxis compared with a regimen including targeted methicillin-resistant Staphylococcus aureus (MRSA) coverage. DESIGN: Randomized prospective clinical trial. PATIENTS: Adult patients who presented to the emergency department with an open fracture between April 2009 and July 2011. INTERVENTIONS: One hundred thirty patients were randomized to receive prophylaxis with either cefazolin alone (control arm) or vancomycin and cefazolin (experimental arm) from presentation to the emergency department until 24 hours after the surgical intervention. Screening for S. aureus carriage was performed with nares swabs and predebridement and postdebridement open fracture wound swabs. Patients underwent prospective assessment for the development of SSI for no less than 30 days and up to 12 months. RESULTS: Nasal colonization of methicillin-sensitive S. aureus and MRSA among the sample was 20% and 3%, respectively. No significant difference in the rates of SSI was observed between the study arms (15% vs 19%, respectively, P = 0.62). Staphylococcus aureus caused 55% of the deep incisional/organ space SSI, with 18% attributed to MRSA. A significantly higher rate of MRSA SSIs was observed among MRSA carriers compared with noncarriers (33% vs 1%, respectively, P = 0.003). CONCLUSIONS: Staphylococcus aureus nasal colonization in trauma patients with open fractures is similar to that of the general community. In this pilot study, the addition of vancomycin to standard antibiotic prophylaxis was found safe, but its efficacy should be evaluated in a larger multiinstitutional trial.

End-stage posttraumatic osteoarthritis treated with THA in osteogenesis imperfecta.

Osteogenesis imperfecta is an incurable genetic disorder manifested with altered bone quality that predisposes patients to a multitude of fractures throughout their lives, including acetabular fractures. The management of acetabular fractures in patients with osteogenesis imperfecta remains a challenging clinical problem, with a paucity of literature supporting treatments and their outcomes. Limited reports in the literature validate the use of total hip arthroplasty (THA) in patients with osteogenesis imperfecta, and they describe the adult population only.This article describes a case of delayed diagnosis of a transverse acetabular fracture and femoral head impaction fracture that led to posttraumatic end-stage hip osteoarthritis in a 16-year-old boy with osteogenesis imperfecta (Sillence Type I) that was sustained after minimal trauma. Clinical examination 3 months postinjury revealed a significant pelvic obliquity, severe pain with hip range of motion, and limited hip range of motion. Imaging studies revealed a complete loss of articular cartilage and significant joint effusion.The patient underwent THA. No postoperative complications occurred. Two-year follow-up showed an excellent clinical result. The patient's hip was pain free, and he was able to walk with no limp.The authors are unaware of any reported cases of children with osteogenesis imperfecta undergoing THA. Based on the reported literature and the authors' experience, THA can be a reliable surgical option for patients with osteogenesis imperfecta.