Hybrid screw fixation for femoral neck fractures: Does it prevent mechanical failure?

INTRODUCTION: Traditionally, femoral neck fracture fixation has been performed using three partially threaded cancellous screws. However, fracture collapse with femoral neck shortening, and varus deformation frequently occurs due to posterior medial comminution and lack of calcar support. We hypothesize replacing the inferior neck/calcar screw with a fully threaded, length stable, screw will provide improved biomechanical stability, decrease femoral neck shortening and varus collapse. METHODS: Ten matched cadaveric pairs (20 femurs) were randomly assigned to two screw fixation groups. Group 1 (Hybrid) utilized one fully threaded calcar screw & two partially threaded superior screws. Group 2 (PT) utilized all partially threaded screws. Specimens underwent standardized femoral neck osteotomies, 45° from the horizontal, with 5 mm posteromedial wedge removed to simulate posteromedial comminution. Screws were placed using fluoroscopic guidance. Specimens were biomechanically tested using two loading sequences: 1) Axial load applied up to 700 N, followed by cyclic loading at 2 Hz with loads of 700 to 1,400 N for 10,000 cycles. 2) All surviving constructs were cyclically loaded to failure in stepwise incremental manner with max load of 4,000 N. Paired t-tests used to compare stiffness, cycles to failure, and max load to failure (defined as 15 mm load actuator displacement). RESULTS: Construct stiffness was 2848 ± 344 N/mm in PT vs. 2767 ± 665 for Hybrid (P = 0.628). Load to failure demonstrated, hybrid superiority with max cycles to failure (3797 ± 400 cycles) vs. (2981 ± 856 cycles in PT) (p = 0.010), and max load prior to failure (3290 ± 196 N) vs. (2891 ± 421 N in PT) (p = 0.010). No significant difference in bone mineral density was noted in any of the specimens. CONCLUSIONS: Our study is the first to assess the biomechanical effects of hybrid fixation for femoral neck fractures. Hybrid screw configuration resulted in significantly stronger constructs, with higher axial load and increased cycles prior to failure. The advantageous mechanical properties demonstrated using a fully threaded inferior calcar screw provides a length stable construct which may prevent the common complication of excessive femoral neck shortening, varus collapse and poor functional outcome.

Risk factors for achilles tendon rupture: A matched case control study.

PURPOSE: The purpose of this study was to elucidate whether body mass index (BMI), activity level, and other risk factors predispose patients to Achilles tendon ruptures. MATERIALS AND METHODS: A retrospective review of 279 subjects was performed (93 with Achilles tendon rupture, matched 1:2 with 186 age/sex matched controls with ankle sprains). Demographic variables and risk factors for rupture were tabulated and compared. RESULTS: The rupture group mean BMI was 27.77 (95% CI, 26.94-28.49), and the control group mean BMI was 26.66 (95% CI, 26.06-27.27). These populations were found to be statistically equivalent (p=0.047 and p<0.001 by two one-sided t-test). A significantly higher proportion of those suffering ruptures reported regular athletic activity at baseline (74%) versus controls (59%, p=0.013). CONCLUSION: There was no clinically significant difference found in BMI between patients with ruptures and controls. Furthermore, it was found that patients who sustained ruptures were also more likely to be active at baseline than their ankle sprain counterparts.

Prevention of inaccurate targeting of proximal screws during reconstruction femoral nailing.

PURPOSE: The purpose of this study was to identify the underlying cause by simulating the forces involved in a controlled laboratory setting, and then to illustrate some intraoperative tips on how to detect this malalignment and suggest solutions prevent this intraoperative complication. METHODS: The Expert Asian Femoral Nail (A2FN) and Proximal Femoral Nail Antirotation (PFNA) reconstruction nail systems were evaluated to compare the characteristics of each nailing system and their reactions to soft tissue tension at the time of proximal reconstruction screw placement. Soft tissue tension was simulated by placing a fulcrum under the distal drill sleeve and exerting a load on the targeting device via the addition of weights. The occurrence and degree of guide malalignment were determined while gradually increasing the weight. RESULTS: When soft tissue tension was simulated on the drill/guide sleeve of the A2FN, the drill sleeve deviated from the proximal screw hole proportionally to the weight applied and the K-wire guide passed outside of the nail at a weight of 7 kg. However, the drill sleeve of the PFNA was aligned exactly to the center of nail axis and the K-wire passed cleanly through the proximal locking hole regardless of weight applied. CONCLUSIONS: Inaccurate guidance of the screw-targeting device can be caused by soft tissue tension. Thus, the authors recommend that careful attention be placed on minimizing soft tissue tension during proximal screw placement while using the targeting device of the A2FN system.

Does the OTA Open Fracture Classification Predict the Need for Limb Amputation? A Retrospective Observational Cohort Study on 512 Patients.

BACKGROUND: Few studies have examined the utility of the Orthopaedic Trauma Association Open Fracture Classification (OTA-OFC) compared to the traditional Gustilo-Anderson classification for prediction of treatment outcomes in patients with open fractures. QUESTIONS/OBJECTIVES:: (1) How do the Gustilo-Anderson classification and OTA-OFC systems compare in accuracy of predicting limb amputation, infection, and need for soft tissue coverage? (2) Is there an OTA-OFC summative threshold score that may guide the discussion and decision-making with regard to limb salvage or amputation? DESIGN: Retrospective observational cohort study; Level IV evidence. SETTING: Level I trauma center and urban safety-net institution. PATIENTS/PARTICIPANTS: Consecutive adult patients with open long bone fractures who underwent operative treatment between January 1, 2007 and December 31, 2012. MAIN OUTCOME AND MEASUREMENTS: Postoperative complications of infection, early limb amputation, and requirement for soft-tissue procedures. RESULTS: The study cohort comprised 512 patients with mean age 49.6 ± 14.9 years. Nineteen patients (3.7%) underwent amputation. The Gustilo-Anderson classification demonstrated no correlations with any of the primary outcome measures, while OTA-OFC summative scores significantly varied between all outcome comparison groups. The skin injury component of the OTA-OFC was an independent predictor of limb amputation (OR, 5.44; 95% CI, 2.37-12.47), and an OTA-OFC summative score of ≥10 best correlated with need for amputation (P < 0.001). Sensitivity and specificity of the reported model were 79% and 94%, respectively. CONCLUSIONS: Our results should be interpreted with caution due to the retrospective nature of our study. Based on our data, the OTA-OFC is superior to the Gustilo-Anderson classification system for prediction of postoperative complications and treatment outcomes in patients with open long bone fractures. A summative threshold score of 10 seems to identify increased odds of successful limb salvage.

Erratum: The Management of Kienböck Disease: A Survey of the ASSH Membership.

[This corrects the article DOI: 10.1055/s-0035-1544225.].

An observational case series of HIV-positive patients treated with open reduction internal fixation for a closed lower extremity fracture.

OBJECTIVES: The purpose of this study was to investigate the influence of immune deficiency status of HIV-positive patients on postoperative complication such as surgical site infection and nonunions. DESIGN: Retrospective observational cohort study: Level III. SETTING: Level I trauma center. PATIENTS/PARTICIPANTS: Consecutive adult HIV-positive patients with closed fractures who underwent operative treatment between January 1, 2001 and December 31, 2012. MAIN OUTCOME AND MEASUREMENTS: postoperative complication including infection and fracture nonunion. RESULTS: A total of 42 HIV-positive patients with closed fractures who underwent surgical fracture fixation were identified during the 12-year study time window. Of these, 18 patients were excluded due to incomplete medical records (n = 16) or open fractures (n = 2). The remaining 24 patients with closed fracture treated surgically (19 males and 5 females; mean age 45.1 ± 10.5 years; age range 20-67 years) were included in the study. Within a 6-month period from the time of injury, 16 patients had a CD4+ cell count >200 and five patients had a CD4+ cell count <200 (CD4+ cell count was not available in three patients). Twenty-two patients (91.6 %) were on antiretroviral therapy at the time of injury. Only one patient, with associated end-stage renal failure and diabetes mellitus, developed a postoperative infection (4.2 %). All patients achieved fracture union within 180 days postoperatively, without the need for surgical revisions. CONCLUSIONS: Our study suggests that HIV infection does not seem to correlate with a higher risk for the development of postoperative complication related to surgical site infection and fracture nonunions after operative fixation of closed fractures.

The Management of Kienböck Disease: A Survey of the ASSH Membership.

Background The purpose of this study was to determine the current trends and common practices for the treatment of Kienböck disease at different stages. Question/Purpose To determine the current trends and common practices by hand surgeons for the treatment of Kienböck disease. Methods A survey with hypothetical Kienböck disease cases stratified by the Lichtman staging system was distributed to the American Society for Surgery of the Hand (ASSH) members. Questions and responses reflected common treatment strategies. Results Of a total of 375 worldwide respondents, preferred treatments of Kienböck disease were as follows: for Stage I disease, an initial trial of splinting was favored (74%), followed by radial shortening osteotomy for continued symptoms. For Stage II disease, 63% of surgeons preferred surgical intervention, particularly radial shortening osteotomy. For Stage IIIa with negative ulnar variance, 69% chose radial shortening osteotomy. Responses were heterogeneous for Stage IIIa Kienböck with positive variance, and capitate shortening osteotomy and vascularized bone grafting were preferred. Salvage procedures predominated for Stage IIIb disease, including proximal row carpectomy (PRC; 42%), intracarpal arthrodesis (21%), and total wrist fusion (10.7%). Similarly, Stage IV disease was treated by 87% of respondents by either PRC or wrist fusion. Without regard to stage of disease, 90% of participants reported using the same Lichtman staging to guide treatment and would also alter treatment strategy based upon ulnar variance. Conclusions Most respondents used Lichtman staging and ulnar variance to guide treatment decisions. Results indicate that the most common surgical treatments were radial shortening osteotomy for early disease and PRC in later stages. Level of Evidence Level IV, Economic/Decision Analysis.

Surgical resection of severe heterotopic ossification after open reduction and internal fixation of acetabular fractures: a case series of 18 patients.

OBJECTIVE: To evaluate the clinical results of surgical resection of severe heterotopic ossification (HO) after the open reduction and internal fixation (ORIF) of acetabular fractures. METHODS: A retrospective chart review was performed between October 2005 and November 2010 on patients undergoing severe HO resection following an acetabular fracture ORIF. Our primary outcome was functional status evaluated by the Harris hip score (HSS). HO resection and hip release was performed using a Kocher-Langenbeck approach in all cases, and a combined radiation and indomethacin regimen was used to prevent HO recurrence. Plain radiographs were also used to evaluate the hip joint for arthritic changes and HO recurrence. RESULTS: A total of 18 patients (17 males and 1 female) were included in our study analysis. The mean patient age was 36.8 (range: 22-54 years old) when HO resection surgery was performed. The mean time interval between acetabular fracture ORIF and HO resection was 9.9 months (range: 3-30 months): it was within 6 months in 7 patients, 6-12 months in 8 patients, and >12 months in 3 patients. The HO was graded as Brooker grade III in 8 patients and grade IV in 10 patients. The mean time interval between HO resection and the latest follow-up was 4.5 years (range: 2.1-7.8 years). The mean Harris hip score (HHS) was 84.5 (range: 38-100), with a clinical outcome rating of excellent in 9 patients, good in 3 patients, fair in 4 patients, and poor in 2 patients (good and excellent rating accounted for 66.7%). The mean hip joint motion arc was 194° (range: 90-260°). Complications included one intraoperative femoral neck fracture, 1 sciatic nerve injury, 2 femoral head avascular necrosis, and 6 mild HO recurrences (33.3%). There was 28.6% recurrence if HO resection was within 6 months and 36.4% if >6 months. There were no cases of severe HO recurrence, wound infections, deep vein thrombosis, or pulmonary embolism. CONCLUSION: The early surgical resection of severe HO after an acetabular fracture ORIF can provide satisfactory results, however the complication rate is relatively high.

Custom-made antibiotic cement nails: a comparative study of different fabrication techniques.

INTRODUCTION: The management of intramedullary long bone infections remains a challenge. Placement of antibiotic cement nails is a useful adjuvant to the antibiotic treatment of osteomyelitis. However, fabrication of antibiotic cement nails can be arduous. The purpose of this article is to introduce an easy and reproducible technique for the fabrication of antibiotics cement nails. MATERIALS AND METHODS: We compared the time required to peel the chest tube off the 6 antibiotic cement nail using 2 different cement-cooling techniques and the addition of mineral oil in the chest tube. Additionally, we evaluated the optimal time to cut the chest tube (before and after cement hardening), consistency of nail's diameter, and the roughness of its surface. Cooling and peeling times were measured and failure was defined as a working time (from cement mixing to have a usable antibiotic cement nail) that exceeded 1 h. RESULTS: When the antibiotic cement nail was left to cool by convection (i.e. air-cooling), we failed to peel the plastic off the cement nail. When the chest tube was cut after conductive cooling (i.e. cold water-cooled), the cooling time was 10 min and the peeling time was 30 min without the use of mineral oil; the addition of mineral oil reduced peeling time to 7.5 min. Following peeling, residual adherent plastic pieces were found along the entire surface of the nail when no mineral oil was used. This was rarely seen when mineral oil was utilized to coat the inner layer of the chest tube. CONCLUSION: Conductively cooling of the cement nail (in cold water) and pre-lubricating the chest tube with mineral oil are 2 tricks that render fabrication of antibiotic nail more efficient, reliable, and practical.

Osteoporosis and the orthopaedic surgeon: basic concepts for successful co-management of patients' bone health.

Osteoporosis has been recognised as a public health concern for at least three decades but it has been relatively recent that the push has been for orthopaedic surgeons to take a more active role in the diagnosis and treatment of patients with decreased bone mineral density (BMD). Most often these patients are encountered after they have suffered a fracture making secondary prevention the area where orthopaedists may exert the greatest influence on patient care. The purpose of this article is to provide a succinct framework for the diagnosis and treatment of patients with decreased BMD. Patients are deemed to have decreased BMD if they have suffered a fragility fracture, a fracture caused by a low-energy traumatic event. These patients are often encountered in the emergency department and admitted for further treatment of their fractures or recommended for follow-up in the clinic. Regardless of treatment course these are opportunities for the orthopaedic surgeon to intervene in the osteoporotic disease process and positively affect a patient's bone health. This article compiles the available literature on osteoporosis and presents it succinctly with the incorporation of both a diagnosis algorithm and treatment profile table. With the use of these two tools, orthopaedic surgeons everywhere should be able to take a more active role in their patients' bone health.

The epidemiology and injury patterns of acetabular fractures: are the USA and China comparable?

BACKGROUND: Acetabular fractures are rare injuries in heterogeneous patient groups, making it difficult to develop adequately powered prospective single-center clinical trials in the USA or Europe. Chinese trauma centers treat a high volume of these injuries, and if the patient population and injury patterns are comparable to those in the USA, this might support development of multicenter studies in Level I trauma centers in the two countries. QUESTIONS/PURPOSES: We determined whether the following parameters were similar between operative acetabular fractures treated at Chinese and US trauma centers: (1) epidemiology of injured patients, (2) mechanism of injuries and fracture types, and (3) hospital stay parameters, including symptomatic postoperative deep vein thrombosis (DVT) rate. METHODS: We extracted data from trauma databases for patients admitted with acetabular fractures managed surgically from 2005 to 2012 for one Chinese center and from 2008 to 2012 for one US center. Sex, age, mechanism of injury, fracture classification, Injury Severity Score (ISS), time from injury to surgery, length of hospital stay, and symptomatic DVT rate were analyzed. We included 661 Chinese patients (539 men, 122 women) and 212 US patients (163 men, 49 women). RESULTS: Mean age at time of injury was different between China and the USA, at 40 years with a unimodal distribution and 44 years with a bimodal distribution (p<0.001), respectively. Incidence of surgically treated acetabular fractures has been increasing in China but decreasing in the USA. Mean ISSs were comparable. Although the distribution of mechanisms of injury was different (p=0.004), high-energy injuries (motor vehicle accidents, falls>10 feet) still accounted for most fractures in both centers. Fracture classifications (per Letournel) were comparable, with posterior wall fractures most common. Mean time from injury to surgery and mean hospital stay were longer in China than in the USA (9 versus 3 days [p<0.001] and 26 versus 11 days [p<0.001], respectively). Symptomatic DVT rates were comparable. CONCLUSIONS: Although we identified differences between the two centers, we also noted important similarities. Multicenter clinical studies involving these locations should be performed with caution and focus on similar end points, taking into account the populations' baseline differences. Because of the potential for such differences, this kind of validation study should be performed before embarking on resource-intensive multicenter trials. LEVEL OF EVIDENCE: Level III, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Balloon tibioplasty: pearls and pitfalls.

Methods of tibial plateau fracture fixation have evolved over the last decades; however the techniques used to reduce these fractures have remained relatively unchanged. Balloon tibioplasty, a minimally invasive novel technique used in the reduction of depressed tibial plateau fractures, has been gaining popularity. This technique offers a slow controlled expansion of the balloon with multidirectional force vectors and a large surface area allowing for more bone to be elevated simultaneously. The technique also creates a well-defined bone void of known volume while theoretically compressing the surrounding bone, potentially limiting the risk of cement extrusion as well as late subsidence of the elevated bone. Although an attractive option, as with all novel techniques there is a learning curve. The purpose of this article is to briefly describe our technique of balloon tibioplasty, potential contraindications, and to illustrate some possible complications, and provide some tips and tricks we have found useful to avoid them.

Osteoporotic ankle fractures: an approach to operative management.

The incidence of osteoporosis is increasing as the elderly population grows. Because these patients remain active, fragility fractures of the ankle are becoming more common. The literature indicates a relatively high complication rate for non-operative management of ankle fractures in this patient cohort, leading surgeons to face challenges unique to patients with poor bone and skin quality. This article discusses techniques to address osteoporotic ankle fractures and reviews the current literature relevant to this issue.

Age and genetic strain differences in response to chronic methylphenidate administration.

Methylphenidate hydrochloride (MPD) is a psychostimulant used in the treatment of attention deficit hyperactive disorder (ADHD) in adolescents and adults alike. Adolescence involves a period of neural development that is highly susceptible to environmental and pharmacological influence. Exposure to a psychostimulant like MPD during this crucial time period may cause permanent changes in neuronal function and formation. Another factor that may influence changes in neuronal function and formation is genetic variability. It has been reported that genetic variability affects both the initial behavioral response to drugs in general and psychostimulants in particular, and subsequently whether tolerance or sensitization is induced. The objective of the present study is to investigate the dose-response effects of repeated MPD administration (0.6, 2.5, or 10.0mg/kg, i.p.) using an open field assay to investigate if there are differences between adolescent and adult Wistar-Kyoto (WKY), Spontaneously Hyperactive rat (SHR), and Sprague-Dawley (SD) rats, respectively, and if the genetic variability between the strains influences the degree of change in locomotion. The acute and chronic administration of MPD resulted in unique differences in the level of increasing intensity in locomotor activity in each rat strain, with adult rats for the most part having a more intense increase in locomotor activity when compared to their adolescent counterparts. In conclusion, significant response differences among rat strains and age to acute and chronic MPD administration were observed only following the 2.5 and 10.0mg/kg i.p. doses and not following the lower MPD dose (0.6 mg//kg i.p.). In addition the variability in activity among the rat strain and age suggests that MPD may affect the same neuronal circuit differently in each strain and age. The unique differences among the individual locomotor indices suggest also that each locomotor index is regulated by different neuronal circuits, and each affected differently by MPD.