Supine Posterior Hoop Plating of Bicondylar Posterior Coronal Shear Tibial Plateau Fractures Without Fibular Osteotomy.

SUMMARY: Tibial plateau posterolateral fragments, especially those associated with articular depression, are difficult to capture and support with anteriorly or lateral based implants. Applying implants to the posterior plateau has traditionally involved a prone approach or fibular osteotomy, especially when access to both the medial and lateral sides is necessary, such as a bicondylar posterior coronal shear fracture pattern. By combining two previously described techniques for posterolateral rim plating and bicondylar hoop plating, we describe a novel technique to apply a posterior bicondylar hoop implant in the supine position without fibular osteotomy for bicondylar posterior coronal shear injuries.

In vitro susceptibility of canine corneal bacterial pathogens to three cross-linking protocols.

OBJECTIVE: To assess in vitro antibacterial efficacy of three cross-linking (XL) protocols on bacteria associated with canine ulcerative keratitis. METHODS: Three XL protocols: UVA 3 mW/cm2 for 60 min, UVA 3 mW/cm2 for 30 min, and UVA 30 mW/cm2 for 3 min with and without application of riboflavin and a riboflavin-only protocol were performed in vitro on the four most common bacterial genera isolated from cases of canine ulcerative keratitis treated at Dick White Referrals, UK. Zones of bacterial growth inhibition (GIZ) associated with treatment were measured and compared. RESULTS: The four most common isolates were Pseudomonas aeruginosa (PA) (48/140, 34.3%), Streptococcus spp. (32/140, 22.9%), Staphylococcus spp. (24/140, 17.1%) and Escherichia coli (EC) (11/140, 7.9%). PA, EC, Streptococcus canis (SC), and Staphylococcus pseudintermedius (SP), isolated from canine corneas, were selected for testing. EC and SC demonstrated growth inhibition following all UVA/riboflavin protocols. PA and SP only displayed growth inhibition following the 60 min UVA/riboflavin protocol. GIZ areas for 60 min UVA/riboflavin protocols were significantly greater than 30 and 3 min UVA/riboflavin protocols (p < .01) and there was no significant difference between 30 and 3 min UVA/riboflavin protocols. In respect to GIZ areas, EC was significantly more susceptible to XL than SP (p = <.01). CONCLUSIONS: All UVA/riboflavin XL protocols caused growth inhibition of EC and SC in vitro. PA and SP did not show clear growth inhibition in vitro following exposure to XL protocol settings of UVA 3 mW/cm2 for 30 min and UVA 30 mW/cm2 for 3 min.

High-risk ankle fractures in high-risk older patients: to fix or nail?

INTRODUCTION: Optimal treatment of high-risk ankle fractures in older, comorbid patients is unknown. Results of open reduction internal fixation (ORIF) versus tibiotalocalcaneal (TTC) fusion nailing for the treatment of high-risk geriatric ankle fractures were investigated. MATERIALS AND METHODS: Results of ORIF versus TTC fusion nailing were evaluated via retrospective case-control cohort study of 60 patients over age 50 with an open ankle fracture or one with at least 50% talar subluxation and at least 1 high-risk comorbidity: diabetes mellitus (DM), peripheral vascular disease, immunosuppression, active smoking, or a BMI > 35. The primary outcome was reoperation rate within 1-year post-surgery. Secondary outcomes include infection, peri-implant fracture, malunion/nonunion, mortality, length of stay, disposition, and hospital acquired complications. RESULTS: Mean age was 71 (ORIF) and 68 (TTC). 12/47 (25.5%) ORIF cases were open fractures versus 4/14 (28.6%) with TTC. There were no significant differences between ORIF and TTC in 1-year reoperation rates (17% vs 21.4%), infection rates (12.8% vs 14.3%), or union rates (76.% vs 85.7%), respectively. One TTC patient sustained a peri-implant fracture treated nonoperatively. There were no significant differences in medical risk factors between groups other than a higher rate of DM in the TTC group, 42.6% vs 78.6%, p = 0.02. Incomplete functional outcome data in this challenging patient cohort precluded drawing conclusions. CONCLUSION: ORIF and TTC fusion nailing result in comparable and acceptable reoperation, infection, and union rates in treating high-risk ankle fractures in patients over 50 with at least 1 major comorbidity for increased complications; further study is warranted.

Early peri-implant fractures after distal femur fracture locked plating?

PURPOSE: To report the peri-implant fracture rates after locked plating of distal femur fractures and examine risk factors. METHODS: Over a 7 year period, 89 AO/OTA 33A/C distal femur fractures were identified and reviewed. After excluding treatment with intramedullary nails, age under 50, those with the proximal femur protected, or those without 6 months of follow-up, 42 distal femur fractures in 41 patients, mean age 72.3 were studied. All were treated with lateral locked plating of distal femur fractures. The details of the constructs were recorded. Mean follow-up was 562 days (18.7 months). RESULTS: 3/42 were open injuries, 9/42 were type C, 16/42 were type A, and 17 were periprosthetic above a knee arthroplasty. Two patients were treated with a dynamic plating construct using all far-cortical locking (FCL) screws in the diaphysis. 40 patients were treated with a variety of non-dynamic diaphyseal constructs including locking, non-locking, and four with 1-2 FCL screws distally. There was one asymptomatic nonunion. 2/2 patients in the dynamically plated group experienced a peri-implant fracture versus 1/40 in the non-dynamically plated group (p = 0.001). 3/9 with an all-locked construct versus 0/25 patients with a most proximal non-locking screw experienced a fracture. CONCLUSIONS: The overall peri-implant fracture risk was 7.1% (3/42), 3/17 patients with a locking screw most proximal experienced a peri-implant fracture, 3/9 with an all-locking construct, and 2/2 patients with a dynamic construct experienced a fracture. These findings merit additional clinical and biomechanical study.

Irreducible Traumatic Fracture-Dislocation of the Hip with Impalement onto the Ischial Spine: A Case Report.

CASE: A 45-year-old man appeared to have a central (protrusio) hip dislocation but actually had a transverse posterior wall acetabulum fracture with irreducible posterior dislocation due to impalement of the femoral head on the ischial spine. He underwent urgent open reduction on presentation and subsequent internal fixation in a staged manner. He developed avascular necrosis at 18 months postoperatively. CONCLUSION: The nondisplaced ilioischial and iliopectineal acetabular radiographic lines were alerts that the dislocation was actually posterior. This led to further imaging before any closed reduction attempts because standard reduction maneuvers would have placed the patient at high risk for iatrogenic femoral head or neck fracture.

Comparison of corneal culture results obtained using the ESwab™ and Amies charcoal swab in canine and feline patients.

OBJECTIVE: The objective of the study was to compare corneal culture results using the ESwab™ and Amies charcoal swab. ANIMALS STUDIED: One hundred fourteen canine and fifteen feline eyes. PROCEDURES: Retrospective analysis of Dick White Referrals bacterial and fungal corneal culture data was conducted. Results were included from canine and feline patients, which presented with suspected infectious keratitis that had samples taken using an Amies charcoal swab followed by an ESwab™ in the same eye. In respect to positive and negative cultures, a McNemar test was conducted comparing instances of disagreement between swab types, and the Kappa coefficient (κ) was calculated to assess the level of agreement between swab types. RESULTS: The ESwab™ produced more positive corneal cultures (71/129 [55.0%]) than the Amies charcoal swab (41/129 [31.8%]). 2/129 eyes produced positive fungal cultures. Considering 37/129 eyes in which both swab types detected a positive corneal culture, the same bacterial species were cultured from each swab type in 34/37 (91.9%) eyes, and an additional bacterial species was cultured by the ESwab™ in 3/37 (8.1%) eyes. In 34/38 (89.5%), instances of disagreement between swab types, the ESwab™ showed a positive culture, and the Amies charcoal swab showed a negative culture from the same eye, and this difference was significant (p < 0.0001). There was a moderate level of agreement between results from both swab types (κ = 0.432). CONCLUSIONS: ESwab™ sampling alone may be superior to Amies charcoal swabs for detecting presence of bacteria in suspected infectious keratitis in cats and dogs.

SEP-363856, a Novel Psychotropic Agent with a Unique, Non-D2 Receptor Mechanism of Action.

For the past 50 years, the clinical efficacy of antipsychotic medications has relied on blockade of dopamine D2 receptors. Drug development of non-D2 compounds, seeking to avoid the limiting side effects of dopamine receptor blockade, has failed to date to yield new medicines for patients. In this work, we report the discovery of SEP-363856 (SEP-856), a novel psychotropic agent with a unique mechanism of action. SEP-856 was discovered in a medicinal chemistry effort utilizing a high throughput, high content, mouse-behavior phenotyping platform, in combination with in vitro screening, aimed at developing non-D2 (anti-target) compounds that could nevertheless retain efficacy across multiple animal models sensitive to D2-based pharmacological mechanisms. SEP-856 demonstrated broad efficacy in putative rodent models relating to aspects of schizophrenia, including phencyclidine (PCP)-induced hyperactivity, prepulse inhibition, and PCP-induced deficits in social interaction. In addition to its favorable pharmacokinetic properties, lack of D2 receptor occupancy, and the absence of catalepsy, SEP-856's broad profile was further highlighted by its robust suppression of rapid eye movement sleep in rats. Although the mechanism of action has not been fully elucidated, in vitro and in vivo pharmacology data as well as slice and in vivo electrophysiology recordings suggest that agonism at both trace amine-associated receptor 1 and 5-HT1A receptors is integral to its efficacy. Based on the preclinical data and its unique mechanism of action, SEP-856 is a promising new agent for the treatment of schizophrenia and represents a new pharmacological class expected to lack the side effects stemming from blockade of D2 signaling. SIGNIFICANCE STATEMENT: Since the discovery of chlorpromazine in the 1950s, the clinical efficacy of antipsychotic medications has relied on blockade of dopamine D2 receptors, which is associated with substantial side effects and little to no efficacy in treating the negative and cognitive symptoms of schizophrenia. In this study, we describe the discovery and pharmacology of SEP-363856, a novel psychotropic agent that does not exert its antipsychotic-like effects through direct interaction with D2 receptors. Although the mechanism of action has not been fully elucidated, our data suggest that agonism at both trace amine-associated receptor 1 and 5-HT1A receptors is integral to its efficacy. Based on its unique profile in preclinical species, SEP-363856 represents a promising candidate for the treatment of schizophrenia and potentially other neuropsychiatric disorders.

Posttraumatic Avascular Necrosis After Proximal Femur, Proximal Humerus, Talar Neck, and Scaphoid Fractures.

Posttraumatic avascular necrosis (AVN) is osteonecrosis from vascular disruption, commonly encountered after fractures of the femoral neck, proximal humerus, talar neck, and scaphoid. These locations have a tenuous vascular supply; the diagnosis, risk factors, natural history, and treatment are reviewed. Fracture nonunion only correlates with AVN in the scaphoid. In the femoral head, the risk is increased for displaced fractures, but the time to surgery and open versus closed treatment do not seem to influence the risk. Patients with collapse are frequently symptomatic, and total hip arthroplasty is the most reliable treatment. In the humeral head, certain fracture patterns correlate with avascularity at the time of injury, but most do not go on to develop AVN due to head revascularization. Additionally, newer surgical approaches and improved construct stability appear to lessen the risk of AVN. The likelihood of AVN of the talar body rises with increased severity of talar injury. The development of AVN corresponds with a worse prognosis and increases the likelihood of secondary procedures. In proximal pole scaphoid fractures, delays in diagnosis and treatment elevate the risk of AVN, which is often seen in cases of nonunion. The need for vascularized versus nonvascularized bone grafting when repairing scaphoid nonunions with AVN remains unclear.

Test-retest reliability of evoked heat stimulation BOLD fMRI.

To date, the blood oxygenated-level dependent (BOLD) functional magnetic resonance imaging (fMRI) technique has enabled an objective and deeper understanding of pain processing mechanisms embedded within the human central nervous system (CNS). In order to further comprehend the benefits and limitations of BOLD fMRI in the context of pain as well as the corresponding subjective pain ratings, we evaluated the univariate response, test-retest reliability and confidence intervals (CIs) at the 95% level of both data types collected during evoked stimulation of 40°C (non-noxious), 44°C (mildly noxious) and a subject-specific temperature eliciting a 7/10 pain rating. The test-retest reliability between two scanning sessions was determined by calculating group-level interclass correlation coefficients (ICCs) and at the single-subject level. Across the three stimuli, we initially observed a graded response of increasing magnitude for both VAS (visual analog score) pain ratings and fMRI data. Test-retest reliability was observed to be highest for VAS pain ratings obtained during the 7/10 pain stimulation (ICC=0.938), while ICC values of pain fMRI data for a distribution of CNS structures ranged from 0.5 to 0.859 (p<0.05). Importantly, the upper and lower confidence interval CI bounds reported herein could be utilized in subsequent trials involving healthy volunteers to hypothesize the magnitude of effect required to overcome inherent variability of either VAS pain ratings or BOLD responses evoked during innocuous or noxious thermal stimulation.

Interobserver Variability in the Measurement of Lower Leg Compartment Pressures.

OBJECTIVES: To determine whether interobserver technical variations and errors in the measurement of compartment pressures may affect measurement accuracy. METHODS: Four above-knee cadaveric specimens were used to create a consistent model of lower leg compartment syndrome. Thirty-eight physicians examined the limbs and measured 4 compartment pressures using the Intra-Compartmental Pressure Monitor (Stryker Orthopaedics). They were observed for correct assembly and use of the monitor. Measurements obtained were compared with known pressures. RESULTS: Of the total number of compartment measurements, 31% were made using the correct technique, 39% were made with lesser errors in technique, and 30% were made with catastrophic errors. Only 60% of measurements made with the correct technique were within 5 mm Hg of the standard pressure. Accuracy dropped to 42% for measurements taken with small errors in technique and 22% when a catastrophic error was committed. CONCLUSIONS: Variations in use of a commercially available pressure monitor exist, and errors are common. Proper use improved accuracy, but even with proper technique, 40% of the measurements were >5 mm Hg from the actual pressure. Based on our data, measurement accuracy with this device should be questioned and viewed within a range. Regular review and education of technique is strongly recommended.

Novel human D-amino acid oxidase inhibitors stabilize an active-site lid-open conformation.

The NMDAR (N-methyl-D-aspartate receptor) is a central regulator of synaptic plasticity and learning and memory. hDAAO (human D-amino acid oxidase) indirectly reduces NMDAR activity by degrading the NMDAR co-agonist D-serine. Since NMDAR hypofunction is thought to be a foundational defect in schizophrenia, hDAAO inhibitors have potential as treatments for schizophrenia and other nervous system disorders. Here, we sought to identify novel chemicals that inhibit hDAAO activity. We used computational tools to design a focused, purchasable library of compounds. After screening this library for hDAAO inhibition, we identified the structurally novel compound, 'compound 2' [3-(7-hydroxy-2-oxo-4-phenyl-2H-chromen-6-yl)propanoic acid], which displayed low nM hDAAO inhibitory potency (Ki=7 nM). Although the library was expected to enrich for compounds that were competitive for both D-serine and FAD, compound 2 actually was FAD uncompetitive, much like canonical hDAAO inhibitors such as benzoic acid. Compound 2 and an analog were independently co-crystalized with hDAAO. These compounds stabilized a novel conformation of hDAAO in which the active-site lid was in an open position. These results confirm previous hypotheses regarding active-site lid flexibility of mammalian D-amino acid oxidases and could assist in the design of the next generation of hDAAO inhibitors.

Does perioperative systemic infection or fever increase surgical infection risks after internal fixation of femur and tibia fractures in an intensive care polytrauma unit?

BACKGROUND: We hypothesized that internal fixation procedures performed on trauma intensive care unit (ICU) patients with systemic infections, some also febrile, would be at increased risk for deep infection. METHODS: A total of 128 patients (mean age, 37.4 years; mean Injury Severity Score [ISS], 34.7) admitted to the ICU with 179 femur or tibia fractures developed systemic infections. Systemic infections included sepsis, pneumonia, urinary tract infections, abdominal infections, and wound infections remote to the fracture. Of the fractures, 33 open and 146 closed underwent 150 intramedullary and 29 plate fixation procedures. Data were gathered regarding antibiotic use, systemic infection timing in relation to the date of fixation, and whether fever (>38.2°C) was present within 24 hours of fixation. Patients were followed up for a mean of 491 days. RESULTS: Twenty-eight procedures were performed a mean of 4.7 days after the diagnosis of a systemic infection, and 151 were performed a mean of 9.3 days before the diagnosis. Forty-five procedures were performed in patients who were febrile within 24 hours. Of the 179 procedures, 10 (5.6%) developed a deep infection. Four patients' implant infection was potentially hematogenously seeded with the same organism as their systemic infection. Neither the timing of the systemic infection in relation to the fixation procedure nor the presence of fever within 24 hours of fixation, days of preoperative antibiotics, location of the fracture, type of fixation (intramedullary nail vs. plate fixation), or type of systemic infection was significantly associated with the development of an infection. The only significant risk factor for developing an orthopedic infection was an open fracture (p < 0.001). CONCLUSION: Internal fixation performed in ICU patients with fever or in close conjunction to the diagnosis of systemic infection led to a 5.6% infection rate, which compares favorably with historic infection rates for fixation of open or closed tibia and femur fractures. LEVEL OF EVIDENCE: Therapeutic, level IV.

Internal fixation in a combat theater hospital.

Limited data are available on the use of internal fixation in combat zone hospitals. The authors performed a retrospective review of 713 surgical cases during 2 Operation Enduring Freedom deployments to a Level III theater hospital in 2007 and 2009 to 2010. The epidemiology and short- to intermediate-term outcomes of patients treated with internal fixation devices were studied. The authors found that, with judicious use, internal fixation under a damage control protocol in a combat theater hospital can be performed with acceptable complication rates.

Structural, kinetic, and pharmacodynamic mechanisms of D-amino acid oxidase inhibition by small molecules.

We characterized the mechanism and pharmacodynamics of five structurally distinct inhibitors of d-amino acid oxidase. All inhibitors bound the oxidized form of human enzyme with affinity slightly higher than that of benzoate (Kd ≈ 2-4 µM). Stopped-flow experiments showed that pyrrole-based inhibitors possessed high affinity (Kd ≈ 100-200 nM) and slow release kinetics (k < 0.01 s(-1)) in the presence of substrate, while inhibitors with pendent aromatic groups altered conformations of the active site lid, as evidenced by X-ray crystallography, and showed slower kinetics of association. Rigid bioisosteres of benzoic acid induced a closed-lid conformation, had slower release in the presence of substrate, and were more potent than benzoate. Steady-state d-serine concentrations were described in a PK/PD model, and competition for d-serine sites on NMDA receptors was demonstrated in vivo. DAAO inhibition increased the spatiotemporal influence of glial-derived d-serine, suggesting localized effects on neuronal circuits where DAAO can exert a neuromodulatory role.

Pharmacodynamic effects of a D-amino acid oxidase inhibitor indicate a spinal site of action in rat models of neuropathic pain.

Inhibition of d-amino acid oxidase (DAAO) activity is a potential target for the treatment of chronic pain. Here we characterized the effects of systemic administration of the DAAO inhibitor 4H-furo[3,2-b]pyrrole-5-carboxylic acid (SUN) in rat models of neuropathic and inflammatory pain. Oral administration of SUN dose dependently attenuated tactile allodynia induced by ligation of the L5 spinal nerve (SNL) and similarly reversed thermal hyperalgesia produced by chronic constriction injury. In addition, SUN was efficacious against complete Freund's adjuvant-induced thermal hyperalgesia. In these models, maximal reversal of pain-related behaviors corresponded with maximum rates of increase in brain and plasma d-serine concentrations, indicative of full inhibition of DAAO activity. To investigate the possible site(s) of action, we recorded spontaneous nerve activity and mechanically evoked responses of central spinal cord dorsal horn neurons and compared these with spontaneous activity of peripheral dorsal root filaments in anesthetized SNL model animals. Oral SUN reduced spontaneous activity in both central and peripheral recordings at doses and pretreatment times that corresponded to reduced mechanical allodynia in behavioral experiments. After intravenous administration of SUN, the onset of action for this central effect was rapid (maximal effects within 30 minutes), but was abolished by severing afferent inputs to the dorsal horn. Overall, these results indicate that inhibition of DAAO in peripheral afferent spinal circuits reduced spontaneous neuronal activity to attenuate pain-related behaviors in rat models of neuropathic and inflammatory pain.

Effects of D-amino acid oxidase inhibition on memory performance and long-term potentiation in vivo.

N-methyl-d-aspartate receptor (NMDAR) activation can initiate changes in synaptic strength, evident as long-term potentiation (LTP), and is a key molecular correlate of memory formation. Inhibition of d-amino acid oxidase (DAAO) may increase NMDAR activity by regulating d-serine concentrations, but which neuronal and behavioral effects are influenced by DAAO inhibition remain elusive. In anesthetized rats, extracellular field excitatory postsynaptic potentials (fEPSPs) were recorded before and after a theta frequency burst stimulation (TBS) of the Schaffer collateral pathway of the CA1 region in the hippocampus. Memory performance was assessed after training with tests of contextual fear conditioning (FC, mice) and novel object recognition (NOR, rats). Oral administration of 3, 10, and 30 mg/kg 4H-furo[3,2-b]pyrrole-5-carboxylic acid (SUN) produced dose-related and steady increases of cerebellum d-serine in rats and mice, indicative of lasting inhibition of central DAAO. SUN administered 2 h prior to training improved contextual fear conditioning in mice and novel object recognition memory in rats when tested 24 h after training. In anesthetized rats, LTP was established proportional to the number of TBS trains. d-cycloserine (DCS) was used to identify a submaximal level of LTP (5× TBS) that responded to NMDA receptor activation; SUN administered at 10 mg/kg 3-4 h prior to testing similarly increased in vivo LTP levels compared to vehicle control animals. Interestingly, in vivo administration of DCS also increased brain d-serine concentrations. These results indicate that DAAO inhibition increased NMDAR-related synaptic plasticity during phases of post training memory consolidation to improve memory performance in hippocampal-dependent behavioral tests.

Decision-making using fMRI in clinical drug development: revisiting NK-1 receptor antagonists for pain.

Substance P (SP) and neurokinin-1 receptors (NK-1R) are localized within central and peripheral sensory pain pathways. The roles of SP and NK-1R in pain processing, the anatomical distribution of NK-1R and efficacy observed in preclinical pain studies involving pain and sensory sensitization models, suggested that NK-1R antagonists (NK-1RAs) would relieve pain in patient populations. Despite positive data available in preclinical tests for a role of NK-1RAs in pain, clinical studies across several pain conditions have been negative. In this review, we discuss how functional imaging-derived information on activity in pain-processing brain regions could have predicted that NK-1RAs would have a low probability of success in this therapeutic domain.

Effect of negative pressure wound therapy on the elution of antibiotics from polymethylmethacrylate beads in a porcine simulated open femur fracture model.

OBJECTIVES: To determine whether negative pressure wound therapy (NPWT) affects antibiotic elution in simulated femur fractures treated with antibiotic impregnated polymethylmethacrylate (PMMA) beads and whether fascial closure between beads and sponge affects the outcome. METHODS: PMMA beads containing vancomycin and tobramycin were placed adjacent to bilateral corticotomies created in 20 anesthetized pigs. In 1 leg, NPWT was applied with the sponge either in direct contact with the beads or superficial to reapproximated fascia lata. The contralateral wound was conventionally closed. Vancomycin and tobramycin concentrations in wound drainage were measured every 12 hours for 72 hours, and tobramycin levels were measured in periosteal tissue obtained at 72 hours. RESULTS: Drainage vancomycin and tobramycin concentrations were highest at 12 hours and fell rapidly by 24 hours but remained steady thereafter. At each 12-hour interval, there were no significant differences in the vancomycin and tobramycin concentrations between NPWT and control wound drainage, although whether the fascia was closed or left open had an influence on vancomycin levels. The total vancomycin and tobramycin eluted into the drains was significantly less in the NPWT group with open fascia. The antibiotic levels measured in wound drainage remained above the minimum inhibitory concentration for common wound organisms throughout the study period. Neither NPWT nor fascial closure had a significant effect on tobramycin periosteal tissue concentrations. CONCLUSIONS: Concurrent application of NPWT with antibiotic impregnated PMMA beads to simulated open femur fractures in pigs did not decrease local antibiotic concentrations but did decrease the total amount of eluted vancomycin and tobramycin locally available when the fascia was left open.

Locked plating of supracondylar periprosthetic femur fractures.

Fifty periprosthetic supracondylar femur fractures above a total knee arthroplasty were reviewed. Fractures were closed Lewis and Rorabeck type II with a stable prosthesis. Twenty-nine patients (group I), were treated with locked condylar plating. Twenty-one patients (group II) were treated with nonlocked plating systems or intramedullary fixation. Minimum follow-up was 1.7 years. There were 5 malunions (20%) in group I and 9 (47%) in group II (P < .05). There were no nonunions in group I and 3 (16%) in group II. Complication rates were 12% in group I, compared to 42% in group II. Group I patients had less operative blood loss, healed in better alignment, and had greater knee motion. All 7 patients treated with a retrograde intramedullary nail developed a malunion or nonunion. Locked plating is a reliable treatment for periprosthetic supracondylar femur fractures. We experienced a lower complication, revision, malunion, and nonunion rate with locked plating versus conventional treatment options.

A biomechanical comparison of 2 ulnar collateral ligament reconstruction techniques.

PURPOSE: To biomechanically compare the Jobe transosseous ulnar collateral ligament (UCL) reconstruction procedure and an interference screw reconstruction (ISR) technique versus the intact elbow UCL. METHODS: Intact stiffness of 10 matched cadaveric elbow pairs was tested via submaximal valgus loading at 4 flexion angles. From each pair, a metal ISR and a traditional transosseous Jobe reconstruction was performed with the use of matched hamstring tendon grafts. Initial stiffness (graft tension), overall stiffness, strain, and failure strength of reconstructed elbows were then tested. RESULTS: At each tested flexion angle, Jobe constructs reproduced the initial and overall stiffness of the intact ligament. ISR constructs did not reproduce the overall stiffness of the native ligament at any flexion angle, and they reproduced the initial stiffness only at 30 degrees and 120 degrees of flexion. Jobe constructs were significantly stronger, failing (10 degrees of displacement) at 22.7 Nm after absorbing 1.58 Nm of energy, versus 13.4 Nm and 0.97 Nm for ISR constructs. In all, 40% of bone tunnel reconstructions failed via tunnel fracture, and 70% of interference screw constructs failed via graft slippage. CONCLUSIONS: The failure strength and initial and overall stiffness of a traditional Jobe bone tunnel UCL reconstruction are superior to those of an ISR, and only traditional Jobe bone tunnel reconstruction reproduces the initial and overall stiffness of an intact UCL. CLINICAL RELEVANCE: Many UCL reconstruction techniques have been described, and a paucity of biomechanical data supports their use. This study found the Jobe bone tunnel technique to be biomechanically superior to the ISR technique.