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Background: The biomechanical effects of radial split tears and vertical tears of the medial meniscus are not well characterized. The goal of the present study was to determine the effects of these meniscal tears and meniscal repair on tibiofemoral joint contact pressure and area. Methods: Eleven fresh-frozen cadaveric knees were loaded to 1000 N of axial load at 0°, 30°, 60°, and 90° of flexion with use of a custom testing apparatus attached to a materials testing machine. Tibiofemoral translations and internal- external and varus-valgus rotations were unconstrained. The knees were tested under four conditions: intact, medial meniscal tear, repaired meniscal tear, and total medial meniscectomy. Radial split tears were created in six knees, and vertical tears were created in five knees. Pressure-sensitive film was used to measure tibiofemoral contact pressure and area. Results: Radial split tears of the medial meniscus did not cause significant changes in tibiofemoral joint contact pressure and area. Vertical tears of the medial meniscus caused increases in tibiofemoral joint contact pressure and reductions in contact area in the medial and lateral compartments that were not significantly different from those associated with total medial meniscectomy. The exception was at 90°, where the lateral compartment pressure asso- ciated with the vertical tear of the medial meniscus was higher than that associated with total medial meniscectomy. In general, after repair of the vertical tear, contact pressure and area values were similar to those in the intact condition. Conclusions: Radial split tears of the medial meniscus that extend from the inner rim to the peripheral third of the meniscus do not cause significant changes injoint contact area and pressure. Vertical tears of the medial meniscus cause nonsignificant increases in joint contact pressure and reductions in contact area in the medial and lateral compartments. Repair of the vertical tear reverses these contact changes, resulting in contact pressure and area similar to the intact state. [ABSTRACT FROM AUTHOR]

Background: Tears of the posterior root of the medial meniscus are becoming increasingly recognized. They can cause rapidly progressive arthritis, yet their biomechanical effects are not understood. The goal of this study was to determine the effects of posterior root tears of the medial meniscus and their repairs on tibiofemoral joint contact pressure and kinematics.Methods: Nine fresh-frozen cadaver knees were used. An axial load of 1000 N was applied with a custom testing jig at each of four knee-flexion angles: 0 degrees, 30 degrees, 60 degrees, and 90 degrees. The knees were otherwise unconstrained. Four conditions were tested: (1) intact, (2) a posterior root tear of the medial meniscus, (3) a repaired posterior root tear, and (4) a total medial meniscectomy. Fuji pressure-sensitive film was used to record the contact pressure and area for each testing condition. Kinematic data were obtained by using a robotic arm to record the position of the knees for each loading condition. Three-dimensional knee kinematics were analyzed with custom programs with use of previously described transformations. The measured variables were axial rotation, varus angulation, lateral translation, and anterior translation.Results: In the medial compartment, a posterior root tear of the medial meniscus caused a 25% increase in peak contact pressure compared with that found in the intact condition (p < 0.001). Repair restored the peak contact pressure to normal. No difference was detected between the peak contact pressure after the total medial meniscectomy and that associated with the root tear. The peak contact pressure in the lateral compartment after the total medial meniscectomy was up to 13% greater than that for all other conditions (p = 0.026). Significant increases in external rotation and lateral tibial translation, compared with the values in the intact knee, were observed in association with the posterior root tear (2.98 degrees and 0.84 mm, respectively) and the meniscectomy (4.45 degrees and 0.80 mm, respectively), and these increases were corrected by the repair.Conclusions: This study demonstrated significant changes in contact pressure and knee joint kinematics due to a posterior root tear of the medial meniscus. Root repair was successful in restoring joint biomechanics to within normal conditions. [ABSTRACT FROM AUTHOR]

Kenya has sought in recent years to digitise its land information system in order to increase reliability and accessibility, both of which are critical to securing land rights, minimising land disputes, and increasing investment in the sector. This thematic report argues for deployment of drone technology in order to increase the reliability of Kenya’s digital land records.

Introduction: The trends of increasing use of cesarean section (CS) with a decrease in assisted vaginal birth (vacuum extraction or forceps) is a major concern in health care systems all over the world, particularly in low-resource settings. Studies show that a first birth by CS is associated with an increased risk of repeat CS in subsequent births. In addition, CS compared to assisted vaginal birth (AVB), attracts higher health service costs. Resource-constrained countries have low rates of AVB compared to high-income countries. The aim of this study was to compare mode of birth in the subsequent pregnancy among women who previously gave birth by vacuum extraction or second stage CS in their first pregnancy at Mulago National Referral Hospital, Uganda., Methods: This was a retrospective cohort study that involved interviews of 81 mothers who had a vacuum extraction or second stage CS in their first pregnancy at Mulago hospital between November 2014 to July 2015. Mode of birth in the subsequent pregnancy was compared using Chi-2 square test and a Fisher's exact test with a 0.05 level of statistical significance., Results: Higher rates of vaginal birth were achieved among women who had a vacuum extraction (78.4%) compared to those who had a second stage CS in their first pregnancy (38.6%), p < 0.001., Conclusions and Recommendations: Vacuum extraction increases a woman's chance of having a subsequent spontaneous vaginal birth compared to second stage CS. Health professionals need to continue to offer choice of vacuum extraction in the second stage of labor among laboring women that fulfill its indication. This will help curb the up-surging rates of CS., (© 2024. The Author(s).)

Background: People living with HIV constitute an important part of the population in regions at risk of Ebola virus disease outbreaks. The two-dose Ad26.ZEBOV, MVA-BN-Filo Ebola vaccine regimen induces strong immune responses in HIV-positive (HIV+) adults but the durability of this response is unknown. It is also unclear whether this regimen can establish immune memory to enable an anamnestic response upon re-exposure to antigen., Methods: This paper describes an open-label, phase 2 trial, conducted in Kenya and Uganda, of Ad26.ZEBOV booster vaccination in HIV+ participants who had previously received the Ad26.ZEBOV, MVA-BN-Filo primary regimen. HIV+ adults with well-controlled infection and on highly active antiretroviral therapy were enrolled, vaccinated with booster, and followed for 28 days. The primary objectives were to assess Ad26.ZEBOV booster safety and antibody responses against the Ebola virus glycoprotein using the Filovirus Animal Non-Clinical Group ELISA., Results: The Ad26.ZEBOV booster was well-tolerated in HIV+ adults with mostly mild to moderate symptoms. No major safety concerns or serious adverse events were reported. Four and a half years after the primary regimen, 24/26 (92 %) participants were still classified as responders, with a pre-booster antibody geometric mean concentration (GMC) of 726 ELISA units (EU)/mL (95 %CI 447-1179). Seven days after the booster, the GMC increased 54-fold to 38,965 EU/mL (95 %CI 23532-64522). Twenty-one days after the booster, the GMC increased 176-fold to 127,959 EU/mL (95 %CI 93872-174422). The responder rate at both post-booster time points was 100 %., Conclusions: The Ad26.ZEBOV booster is safe and highly immunogenic in HIV+ adults with well-controlled infection. The Ad26.ZEBOV, MVA-BN-Filo regimen can generate long-term immune memory persisting for at least 4·5 years, resulting in a robust anamnestic response., Trial Registration: Pan African Clinical Trial Registry (PACTR202102747294430)., Clinicaltrials: gov (NCT05064956)., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Janssen Vaccines & Prevention B.V. was the vaccine manufacturer and donated the vaccine for this study. BKe, AG, CM, KL, and CR were full-time employees of Janssen, Pharmaceutical Companies of Johnson & Johnson at the time of the study. AG, CM, KL, and CR, declared ownership of shares in Janssen, Pharmaceutical Companies of Johnson & Johnson. All other authors declare funding from the Innovative Medicines Initiative 2 Joint Undertaking. GAM reports having received travel grant from the vaccine manufacturer to attend scientific meetings and present, after the study has completed., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Study Design: This was a preclinical study., Objective: Evaluate sex-dependent differences in the bone healing response to recombinant human bone morphogenetic protein-2 (rhBMP-2) in a rat posterolateral spinal fusion model., Summary of Background Data: Minimal and conflicting data exist concerning potential sex-dependent differences in rhBMP-2-mediated bone regeneration in the context of spinal fusion., Materials and Methods: Forty-eight female and male Sprague-Dawley rats (N=24/group), underwent L4-L5 posterolateral fusion with bilateral placement of an absorbable collagen sponge, each loaded with 5 µg of bone morphogenetic protein-2 (10 µg/animal). At eight weeks postoperative, 10 specimens of each sex were tested in flexion-extension with quantification of range of motion and stiffness. The remaining specimens were evaluated for new bone growth and successful fusion via radiography, blinded manual palpation and microcomputed tomography (microCT). Laboratory microCT quantified bone microarchitecture, and synchrotron microCT examined bone microstructure at the 1 µm level., Results: Manual palpation scores differed significantly between sexes, with mean fusion scores of 2.4±0.4 in females versus 3.1±0.6 in males ( P <0.001). Biomechanical stiffness did not differ between sexes, but range of motion was significantly greater and more variable for females versus males (3.7±5.6° vs. 0.27±0.15°, P <0.005, respectively). Laboratory microCT showed significantly smaller volumes of fusion masses in females versus males (262±87 vs. 732±238 mm 3 , respectively, P <0.001) but significantly higher bone volume fraction (0.27±0.08 vs. 0.12±0.05, respectively, P <0.001). Mean trabecular thickness was not different, but trabecular number was significantly greater in females (3.1±0.5 vs. 1.5±0.4 mm -1 , respectively, P <0.001). Synchrotron microCT showed fine bone structures developing in both sexes at the eight-week time point., Conclusions: This study demonstrates sex-dependent differences in bone regeneration induced by rhBMP-2. Further investigation is needed to uncover the extent of and mechanisms underlying these sex differences, particularly at different doses of rhBMP-2., Competing Interests: The authors report no conflicts of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: To evaluate the individual contributions to stability of the superficial and deep deltoid ligaments in the setting of SER IV ankle fractures., Methods: Nineteen total cadaveric specimens were used. SER IV injuries were created with the rupture of either the superficial (SER IV-S) (n = 9) or deep deltoid (SER IV-D) (n = 10). These were tested by applying an external rotation force (1 Nm, 2 Nm, 3 Nm, and 4 Nm). Changes in the position of the talus were recorded with a 3D motion tracker. Injury conditions were compared with a 4-step general linear model with repeated measures. Injury condition was also compared with the intact state and to each other using 2-tailed t tests., Results: The general linear model showed that increased loading had a significant effect with axial rotation (P = 0.02) and sagittal translation (P = 0.003). SER IV-S and SER IV-D showed significantly greater instability compared with the intact state in axial rotation (1 Nm, 2 Nm, and 3 Nm). SER IV-S and SER IV-D did not significantly differ from each other., Conclusions: SER IV fracture patterns can be unstable with isolated injury to either the superficial or deep deltoid. This challenges the notion that deep deltoid rupture is necessary. Further clinical studies would help quantify the consequences of this instability., Competing Interests: The authors report no conflict of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

We recently developed a recombinant growth factor-free bone regenerative scaffold composed of stoichiometric hydroxyapatite (HA) ceramic particles and human demineralized bone matrix (DBM) particles (HA-DBM). Here, we performed the first pre-clinical comparative evaluation of HA-DBM relative to the industry standard and established positive control, recombinant human bone morphogenetic protein-2 (rhBMP-2), using a rat posterolateral spinal fusion model (PLF). Female Sprague-Dawley rats underwent bilateral L4-L5 PLF with implantation of the HA-DBM scaffold or rhBMP-2. Fusion was evaluated using radiography and blinded manual palpation, while biomechanical testing quantified the segmental flexion-extension range-of-motion (ROM) and stiffness of the fused segments at 8-weeks postoperatively. For mechanistic studies, pro-osteogenic gene and protein expression at 2-days and 1-, 2-, and 8-weeks postoperatively was assessed with another cohort. Unilateral fusion rates did not differ between the HA-DBM (93%) and rhBMP-2 (100%) groups; however, fusion scores were higher with rhBMP-2 (p = 0.008). Both treatments resulted in significantly reduced segmental ROM (p < 0.001) and greater stiffness (p = 0.009) when compared with non-operated controls; however, the degree of stabilization was significantly higher with rhBMP-2 treatment relative to the HA-DBM scaffold. In the mechanistic studies, PLGA and HA scaffolds were used as negative controls. Both rhBMP-2 and HA-DBM treatments resulted in significant elevations of several osteogenesis-associated genes, including Runx2, Osx, and Alp. The rhBMP-2 treatment led to significantly greater early, mid, and late osteogenic markers, which may be the mechanism in which early clinical complications are seen. The HA-DBM scaffold also induced osteogenic gene expression, but primarily at the 2-week postoperative timepoint. Overall, our findings show promise for this 3D-printed composite as a recombinant growth factor-free bone graft substitute for spinal fusion. STATEMENT OF SIGNIFICANCE: Despite current developments in bone graft technology, there remains a significant void in adequate materials for bone regeneration in clinical applications. Two of the most efficacious bone graft options are the gold-standard iliac crest bone graft and recombinant human-derived bone morphogenetic protein-2 (rhBMP-2), available commercially as Infuse™. Although efficacious, autologous graft is associated with donor-site morbidity, and Infuse™ has known side effects related to its substantial host inflammatory response, possibly associated with a immediate, robust osteoinductive response. Hence, there is a need for a bone graft substitute that provides adequate osteogenesis without associated adverse events. This study represents a significant step in the design of off-the-shelf growth factor-free devices for spine fusion., Competing Interests: Declaration of Competing Interest M.A.P., S.M., J.G.L., A.G., D.E., M.H., J.Y., S.J., C.Y., K.R.B., R.M.H., M.M., A.G.P., W.K.H., S.R.S., and E.L.H. have nothing to disclose that may create a conflict of interest within this body of work. A.E.J. and R.N.S. are cofounders of the company Dimension Inx, LLC – which aims to create biomaterials, including 3D-printed biologically active materials, that induce tissue regeneration and repair – including some of the materials discussed in this paper. As of October 2020, A.E.J. is the Chief Technology Officer (CTO) and R.N.S. is the Chief Science Officer (CSO) of Dimension Inx, LLC. The trademark for Hyperelastic Bone® is owned by Dimension Inx. The study design, reporting of data, and interpretation of data in this body of work was not influenced by the interests of Dimension Inx LLC., (Copyright © 2021. Published by Elsevier Ltd.)

Uncertainty in rainfall pattern has put rain-fed agriculture in jeopardy, even for the regions considered high rainfall potential like the Central Highlands of Kenya (CHK). The rainfall pattern in the CHK is spatially and temporally variable in terms of onset and cessation dates, frequency and occurrence of dry spells, and seasonal distribution. Appraisal of the variability is further confounded by the lack of sufficient observational data that can enable accurate characterisation of the rainfall pattern in the region. We, therefore, explored the utilisation of satellite daily rainfall estimates from the National Aeronautics and Space Administration (NASA) for rainfall pattern characterisation in the CHK. Observed daily rainfall data sourced from Kenya meteorological department were used as a reference point. The observation period was from 1997 to 2015. Rainfall in the CHK was highly variable, fairly distributed and with low intensity in all the seasons. Onset dates ranged between mid-February to mid-March and mid-August to mid-October for long rains (LR) and short rains (SR) seasons, respectively. Cessation dates ranged from late May to mid-June and mid-December to late December for the LR and SR, respectively. There was a high probability (93%) of dry spell occurrence. More research needs to be done on efficient use of the available soil moisture and on drought tolerant crop varieties to reduce the impact of drought on crop productivity. Comparison between satellite and observed rain gauge data showed close agreement at monthly scale than at daily scale, with general agreement between the two datasets. Hence, we concluded that, given the availability, accessibility, frequency of estimation and spatial resolution, satellite estimates can complement observed rain gauge data. Stakeholders in the fields of agriculture, natural resource management, environment among others, can utilise the findings of this study in planning to reduce rainfall-related risks and enhance food security., (© 2020 Published by Elsevier Ltd.)

Panton-Valentine leukocidin gene is produced by Staphylococcus aureus , and methicillin-resistant Staphylococcus aureus isolates as a pore-forming toxin is largely responsible for skin and soft tissue illnesses. MRSA produces PVL toxins through luk S and luk F proteins causing tissue necrosis by damaging membrane of the defense cells. Presence of PVL toxin was tested from the 54 S. aureus clinical isolates obtained from Thika and Kiambu Level 5 Hospitals, in Kiambu County, Kenya, by Geno Type® MRSA assay (Hain Life Science, Nehren, Germany). DNA was isolated from freshly harvested bacterial cultures by spin column using Geno Type DNA isolation kit. The detection of PVL toxins was performed by amplification of genomic DNA and by reverse hybridization that identifies PVL genes using Geno Type MRSA kit. Out of 138 samples that were collected from patients in Kiambu County, 54 S. aureus isolates were obtained, of which 14 (25.9%; 95% CI = 11.9-38.9) samples had PVL toxins. The isolates that were obtained from the female patients had a higher PVL toxin prevalence of 35.7%, while the isolates collected from the male patients had a lower prevalence of 15.4% ( P = 0.09). The pediatrics department had the highest PVL gene prevalence compared to outpatient department and surgical units ( P = 0.08). However, the age groups of patients and the hospital attended by patients showed no significant difference in terms of PVL gene prevalence ( P = 0.26). Therefore, the patients' gender and hospital units were not significantly associated with PVL gene prevalence ( P = 0.08). This study shows that PVL positive isolates occur in the sampled hospitals in the county and female as well as children must be taken into consideration among patients with wound infections when isolating S. aureus ., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2020 Sani Iliya et al.)

Introduction: Methicillin resistant Staphylococcus aureus (MRSA) causes illness to people and can be picked up from both healthcare facilities and the environment leading to high morbidity and mortality. The study was aimed at identifying phenotypic characteristics of Methicillin-Resistant Staphylococcus aureus and determine the antibiotic susceptibility pattern of clinical samples isolated from patients attending or admitted in two health facilities in Kiambu County, Kenya., Methodology: One hundred and thirty-eight (138) clinical samples were collected from patients attending Thika and Kiambu Level-5 Hospitals. The isolates were obtained using standard bacteriological techniques. Methicillin resistance of Staphylococcus aureus was determined using the cefoxitin disk diffusion test., Results: Out of 138 samples, 54 (39.1%) were found to have Staphylococcus aureus of which 22 (40.7%) were shown to be MRSA using the cefoxitin- based susceptibility test. Antibiotic susceptibility testing using Kirby-Bauer technique was performed on all 54 isolates. The highest sensitivity was found in chloramphenicol 46 (85.2%) and lowest in penicillin-G 8 (14.8%). Multi-Drug Resistance (MDR) was reported in 35 (64.8%) of the 54 isolates of Staphylococcus aureus. All 22 MRSA strains were found to be MDR., Conclusions: the data obtained revealed that there is presence of MRSA in healthcare settings in Kiambu County, Kenya with varying antibiotic sensitivity patterns as well as multidrug resistance. The findings will help healthcare workers in the county to develop preventive strategy as well as institute policy for antibiotic usage, infection control and surveillance., Competing Interests: No Conflict of Interest is declared, (Copyright (c) 2020 Sani Iliya, Jonathan Mwangi, Ronald Maathai, Mary Muriuki.)

Study design Biomechanical cadaveric study  Objective To compare biomechanical properties of a single stand-alone interbody fusion and a single-level pedicle screw construct above a previous lumbar pedicle fusion. Summary of background data Adjacent segment disease (ASD) is spondylosis of adjacent vertebral segments after previous spinal fusion. Despite the consensus that ASD is clinically significant, the surgical treatment of ASD is controversial. Methods Lateral lumbar interbody fusion (LLIF) and posterior spinal fusion (PSF) with pedicle screws were analyzed within a validated cadaveric lumbar fusion model. L3-4 vertebral segment motion was analyzed within the following simulations: without implants (intact), L3-4 LLIF-only, L3-4 LLIF with previous L4-S1 PSF, L3-4 PSF with previous L4-S1 PSF, and L4-S1 PSF alone. L3-4 motion values were measured during flexion/extension with and without axial load, side bending, and axial rotation. Results L3-4 motion in the intact model was found to be 4.7 ± 1.2 degrees. L3-4 LLIF-only decreased motion to 1.9 ± 1.1 degrees. L3-4 LLIF with previous L4-S1 fusion demonstrated less motion in all planes with and without loading (p < 0.05) compared to an intact spine. However, L3-4 motion with flexion/extension and lateral bending was noted to be greater compared to the L3-S1 construct (p < 0.5). The L3-S1 PSF construct decreased motion to less than 1° in all planes of motion with or without loading (p < 0.05). The L3-4 PSF with previous L4-S1 PSF constructs decreased the flexion/extension motion by 92.4% compared to the intact spine, whereas the L3-4 LLIF with previous L4-S1 PSF constructs decreased motion by 61.2%. Conclusions Stand-alone LLIF above a previous posterolateral fusion significantly decreases motion at the adjacent segment, demonstrating its utility in treating ASD without necessitating revision. The stand-alone LLIF is a biomechanically sound option in the treatment of ASD and is advantageous in patient populations who may benefit from less invasive surgical options., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2019, Chioffe et al.)

Objectives: To biomechanically analyze instability in supination external rotation (SER) II/III patterns., Methods: Nineteen cadaver legs were tested in a mechanical jig. One, 2, 3, and 4 Nm of external rotation were applied to intact ankles, SER II injuries, and SER III injuries. The talar position relative to the tibia was recorded using 3D motion tracking. Change from the unloaded state in each condition and the torque level was calculated. Results were analyzed using analysis of variance with post hoc paired t tests., Results: SER II showed statistically significant differences from the intact state with coronal translation (2, 3, and 4 Nm), sagittal translation (1 and 2 Nm), axial rotation (1, 2, 3, and 4 Nm), and coronal rotation (3 and 4 Nm). SER III showed statistically significant differences from the intact state with coronal translation (2, 3, and 4 Nm), sagittal translation (1, 2, and 3 Nm), axial rotation (1, 2, 3, and 4 Nm), and coronal rotation (3 and 4 Nm). SER II and SER III differed significantly from each other with coronal translation (1, 2, and 3 Nm), axial rotation (2, 3, and 4 Nm), and coronal rotation (1, 3, and 4 Nm)., Conclusion: Instability in SER injuries has only been described with coronal translation and suggests that deltoid rupture is necessary. Our data demonstrate instability in SER II/III in sagittal translation and axial rotation as well as subtle instability in coronal translation. The clinical impact is unclear, but better understanding of long-term sequelae of this instability is needed.

Introduction: Treatment of supination external rotation type IV (SER-IV) ankle injuries has focused on reduction and fixation of the fibula and syndesmosis (ORIF), not repair of the deltoid ligament., Methods: Twenty-one ankles were analyzed with a motion capture system. Uninjured ankles were stressed and compared to ankles with SER-IV injuries, then with ORIF, and finally ORIF and deltoid repair., Results: After deltoid ligament repair, talar coronal and axial rotation normalized to the uninjured state and were significantly reduced compared to ORIF alone., Discussion: Deltoid ligament repair after an SER-IV ankle injury can help directly reduce and stabilize the tibiotalar joint., (© 2019 Professor P K Surendran Memorial Education Foundation. Published by Elsevier B.V. All rights reserved.)

Background: Pin fixation of Salter-II proximal humeral fractures in adolescents approaching skeletal maturity has potential complications that can be avoided with single-screw fixation. However, the strength of screw fixation relative to parallel and diverging pin fixation is unknown. To compare the biomechanical fixation strength between these fixation modalities, we used synthetic composite humeri, and then compared these results in composite bone with cadaveric humeri specimens., Methods: Parallel pinning, divergent pinning, and single-screw fixation repairs were performed on synthetic composite humeri with simulated fractures. Six specimens of each type were tested in axial loading and other 6 were tested in torsion. Five pair of cadaveric humeri were tested with diverging pins and single screws for comparison., Results: Single-screw fixation was statistically stronger than pin fixation in axial and torsional loading in both composite and actual bone. There was no statistical difference between composite and cadaveric bone specimens., Conclusion: Single-screw fixation can offer greater stability to adolescent Salter-II fractures than traditional pinning., Clinical Relevance: Single-screw fixation should be considered as a viable alternative to percutaneous pin fixation in transitional patients with little expected remaining growth.

Background: A lateral approach with open reduction and internal fixation with a plate is a very effective technique for the majority of distal fibular fractures. However, this open approach for ankle fixation may be complicated by wound dehiscence and infection, especially in high-risk patients. An alternative to plating is an intramedullary implant, which allows maintenance of length, alignment, and rotation and which allows for decreased soft tissue dissection. While there has been clinical data suggesting favorable short-term outcomes with these implants, there is no current biomechanical literature investigating this technology in this particular fracture pattern. This study sought to biomechanically compare an emerging technology with an established method of fixation for distal fibular fractures that traditionally require an extensive exposure., Methods: Ten matched cadaveric pairs from the proximal tibia to the foot were prepared to simulate an Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) 44C2 ankle fracture and randomized to fixation with a distal fibular locking plate or intramedullary fibular rod. A constant 700-N axial load was applied, and all specimens underwent testing for external rotation stiffness, external rotation cyclic loading, and torque to failure. The syndesmotic diastasis, stiffness, torque to failure, angle at failure, and mode of failure were obtained from each specimen., Results: There was no significant difference in syndesmotic diastasis during cyclic loading or at maximal external rotation between the rod and plate groups. Post-cycle external rotation stiffness across the syndesmosis was significantly higher for the locking plate than the fibular rod. There was no significant difference between the rod and plate in torque at failure or external rotation angle. The majority of specimens had failure at the syndesmotic screw., Conclusions: In the present cadaveric study of an AO/OTA 44C2 ankle fracture, a modern fibular rod demonstrated less external rotation stiffness while maintaining the syndesmotic diastasis to within acceptable tolerances and having similar failure characteristics.

Background: Attritional bone loss in patients with recurrent anterior instability has successfully been treated with a bone block procedure such as the Latarjet. It has not been previously demonstrated whether cortical or cancellous screws are superior when used for this procedure., Purpose: To assess the strength of stainless steel cortical screws versus stainless steel cannulated cancellous screws in the Latarjet procedure., Study Design: Controlled laboratory study., Methods: Ten fresh-frozen matched-pair shoulder specimens were randomized into 2 separate fixation groups: (1) 3.5-mm stainless steel cortical screws and (2) 4.0-mm stainless steel partially threaded cannulated cancellous screws. Shoulder specimens were dissected free of all soft tissue and a 25% glenoid defect was created. The coracoid process was osteomized, placed at the site of the glenoid defect, and fixed in place with 2 parallel screws., Results: All 10 specimens failed by screw cutout. Nine of 10 specimens failed by progressive displacement with an increased number of cycles. One specimen in the 4.0-mm screw group failed by catastrophic failure on initiation of the testing protocol. The 3.5-mm screws had a mean of 274 cycles (SD, ±171 cycles; range, 10-443 cycles) to failure. The 4.0-mm screws had a mean of 135 cycles (SD, ±141 cycles; range, 0-284 cycles) to failure. There was no statistically significant difference between the 2 types of screws for cycles required to cause failure (P = .144)., Conclusion: There was no statistically significant difference in energy or cycles to failure when comparing the stainless steel cortical screws versus partially threaded cannulated cancellous screws., Clinical Relevance: Latarjet may be performed using cortical or cancellous screws without a clear advantage of either option.

Study Design: Cadaveric study to accurately measure lumbar neuroforaminal area and height throughout the flexion-extension range of motion (ROM)., Objective: Create a new computed tomography (CT)-based specimen-specific model technique to provide insight on the effects of kinematics on lumbar neuroforamen morphology during flexion-extension ROM., Summary of Background Data: Nerve root compression is a key factor in symptomatic progression of degenerative disc disease because these changes directly affect neuroforaminal area. Traditional techniques to evaluate the neuroforamen suffer from poor accuracy, have inherent limitations, and fail to provide data throughout the ROM., Methods: Six cadaveric specimens (L1-sacrum) were instrumented with radiopaque spheres and CT scanned. 3-Dimensional reconstructions were made of each vertebra and the sphere locations determined. During kinematic testing, the spheres were located in relation to optoelectronic targets attached to each vertebra. The result was a 3-dimensional representation of the specimen's CT reconstruction moving in response to experimental data. Bony contours of the L2-L3 and L4-L5 neuroforamen were digitized producing continuous neuroforaminal area and height data throughout the ROM., Results: Neuroforaminal area and height linearly increased in flexion and decreased in extension. There was significant correlation between flexion-extension motion and percent change in area (L2-L3: 3.1%/deg, R = 0.94, L4-L5: 2.5%/deg, R = 0.90) and neuroforaminal height (L2-L3: 2.1%/deg, R = 0.95, L4-L5: 1.6%/deg, R = 0.93). Regression analysis showed that the ratio between neuroforaminal height and area is at least 1:1.5 such that a 100% increase in height is associated with an area increase of more than 150%., Conclusion: This is the first study to measure lumbar neuroforaminal area and height throughout flexion-extension ROM. The CT-based specimen-specific model technique can accurately evaluate the effect of kinematics on morphological features of the spine. The demonstrated increase in neuroforaminal dimension in flexion is consistent with treatment modalities used in clinical therapies to relieve radicular symptoms., Level of Evidence: N/A.

Background: Meniscal root tears have attracted increasing interest in recent years. Fixation is an important factor for rehabilitation and avoidance of early failure. Suture fixations have been the most commonly used techniques. The current study aimed to evaluate the maximum failure load of the native meniscal roots (anteromedial, posteromedial, anterolateral, and posterolateral) and of 3 commonly used meniscal root fixation techniques (2 simple stitches, modified Kessler stitch, and loop stitch)., Hypotheses: (1) There will be no difference in maximum failure load between the native meniscal roots. (2) The loop stitch will sustain the greatest maximum load to failure, followed by the modified Kessler stitch and the 2 simple stitches. (3) The maximum failure load of the native meniscal roots will not be restored by the tested fixation methods., Study Design: Controlled laboratory study., Methods: The maximum failure load of the 4 human native meniscal roots was evaluated using 64 human meniscal roots. Additionally, the maximum failure load of the 3 fixation techniques was evaluated on 24 meniscal roots: (1) 2 simple stitches, (2) modified Kessler stitch, and (3) loop stitch using a suture shuttle., Results: The average maximum failure load of the native meniscal roots was 594 ± 241 N (anterolateral: 692 ± 304 N; posterolateral: 648 ± 140 N; anteromedial: 407 ± 180 N; posteromedial: 678 ± 200 N). The anteromedial root was significantly weaker than the posterolateral and posteromedial roots (P = .04 and P = .01, respectively). Regarding fixation techniques, the maximum failure load of the 2 simple stitches was 64.1 ± 22.5 N, the modified Kessler stitch was 142.6 ± 33.3 N, and the loop was 100.9 ± 41.6 N. None of the fixation techniques recreated the strength of the native roots., Conclusion: The native anterolateral root was the strongest meniscal root, and the anteromedial root was the weakest meniscal root. Regarding primary fixation strength, the modified Kessler stitch was the strongest technique compared with the loop and the 2 simple stitches., Clinical Relevance: None of our tested fixation methods restored the strength of native meniscal roots. Thus, rehabilitation after meniscal root fixation should proceed cautiously.

Purpose: The proximal row carpectomy (PRC) is a clinically useful motion-preserving procedure for various arthritides of the wrist. However, there are few studies on the "contact biomechanics" after PRC. The purpose of this study is to evaluate the contact biomechanics in terms of pressure, area, and contact location of the intact and PRC wrist., Methods: Six fresh-frozen cadaver forearms were tested in neutral, 45 degrees of flexion, and 45 degrees of extension. In the intact wrist, Fuji UltraSuperLow pressure contact film was placed in the radioulnocarpal joint. The specimen was loaded to a total force of 200 N. We then performed a PRC, and the experiment was repeated using Fuji Low film. The film was scanned and analyzed with a customized MATLAB program. Multivariable analysis of variance with multiple contrast testing and Student's t-test were performed for statistics., Results: In the intact wrist, scaphoid contact pressure averaged 1.4 megapascals (MPa), and lunate contact pressure averaged 1.3 MPa. In terms of contact location, scaphoid contact in the intact wrist significantly moved dorsal and ulnar in flexion and significantly moved volar and radial in extension. Lunate contact significantly moved dorsal in flexion. PRC wrist contact pressure was 3.8 times that of the intact wrist, and the contact area was approximately 26% that of the intact wrist. Lastly, in terms of the amount of contact translation after PRC, the capitate contact translated (7.5 mm) more than did the scaphoid contact (5.6 mm) and had about equal translation to that of the lunate (7.3 mm)., Conclusions: Contact pressure increased significantly and contact area decreased significantly after PRC. There is significant contact translation after PRC (more than scaphoid translation but equal to lunate translation), which provides quantitative support of the theory that translational motion of the PRC may explain its good clinical outcomes.

This study explored which of two modes of access to a biomedical database better supported problem solving in bacteriology. Boolean access, which allowed subjects to frame their queries as combinations of keywords, was compared to hypertext access, which allowed subjects to navigate from one database node to another. The accessible biomedical data were identical across systems. Data were collected from 42 first year medical students, each randomized to the Boolean or hypertext system, before and after their bacteriology course. Subjects worked eight clinical case problems, first using only their personal knowledge and, subsequently, with aid from the database. Database retrievals enabled students to answer questions they could not answer based on personal knowledge only. This effect was greater when personal knowledge of bacteriology was lower. The results also suggest that hypertext was superior to Boolean access in helping subjects identify possible infectious agents in these clinical case problems.