A Strategy for Accessing Nanobody-Based Electrochemical Sensors for Analyte Detection in Complex Media.

Nanobodies are single variable domain antibodies isolated from camelids and are rapidly distinguishing themselves as ideal recognition elements in biosensors due to their comparative stability, ease of production and isolation, and high binding affinities. However, transducing analyte binding by nanobodies in real time is challenging, as most nanobodies do not directly produce an optical or electrical signal upon target recognition. Here, we report a general strategy to fabricate sensitive and selective electrochemical sensors incorporating nanobodies for detecting target analytes in heterogeneous media, such as cell lysate. Graphite felt can be covalently functionalized with recombinant HaloTag-modified nanobodies. Subsequent encapsulation with a thin layer of a hydrogel using a vapor deposition process affords encapsulated electrodes that directly display a decrease in current upon antigen binding, without added redox mediators. Differential pulse voltammetry affords clear and consistent decreases in electrode current across multiple electrode samples for specific antigen concentrations. The change in observed current vs increasing antigen concentration follows Langmuir binding characteristics, as expected. Importantly, selective and repeatable target binding in unpurified cell lysate is only demonstrated by the encapsulated electrode, with an antigen detection limit of ca. 30 pmol, whereas bare electrodes lacking encapsulation produce numerous false positive signals in control experiments.

Colorimetric Cotton Swab for Viral Protease Detection.

Reporting the activity of a specific viral protease remains an acute need for rapid point-of-care detection strategies that can distinguish active infection from a resolved infection. In this work, we present a simple colorimetric approach for reporting the activity of a specific viral protease through direct color conversion on a cotton swab, which has the potential to be extended to detect the corresponding virus. We use SARS-CoV-2 viral protease as a proof-of-concept model system. We use 4-aminomalachite green (4-AMG) as the base chromophore structure to design a CoV2-AMG reporter, which is selective toward the SARS-CoV-2 Mpro but does not produce any observable color change in the presence of other viral proteases. The color change is observable by the naked eye, as well as smartphone imaging, which affords a lower limit of detection. The simplicity and generalizability of the method could be instrumental in combating future viral outbreaks.

Immobilization of Nanobodies with Vapor-Deposited Polymer Encapsulation for Robust Biosensors.

To produce next-generation, shelf-stable biosensors for point-of-care diagnostics, a combination of rugged biomolecular recognition elements, efficient encapsulants, and innocuous deposition approaches is needed. Furthermore, to ensure that the sensitivity and specificity that are inherent to biological recognition elements are maintained in solid-state biosensing systems, site-specific immobilization chemistries must be invoked such that the function of the biomolecule remains unperturbed. In this work, we present a widely applicable strategy to develop robust solid-state biosensors using emergent nanobody (Nb) recognition elements coupled with a vapor-deposited polymer encapsulation layer. As compared to conventional immunoglobulin G antibodies, Nbs are smaller (12-15 kDa as opposed to ~150 kDa), have higher thermal stability and pH tolerance, boast greater ease of recombinant production, and are capable of binding antigens with high affinity and specificity. Photoinitiated chemical vapor deposition affords thin, protective polymer barrier layers over immobilized Nb arrays that allow for retention of Nb activity and specificity after both storage under ambient conditions and complete desiccation. Most importantly, we also demonstrate that vapor-deposited polymer encapsulation of Nb arrays enables specific detection of target proteins in complex heterogeneous samples, such as unpurified cell lysate, which is otherwise challenging to achieve with bare Nb arrays.

Metal-Free Organic Chromophores Featuring an Ethynyl-Thienothiophene Linker with an n-Hexyl Chain for Translucent Dye-Sensitized Solar Cells.

We report the simple synthesis of two organic chromophores featuring an ethynyl-thienothiophene linker with an n-hexyl chain (CSD-03 and CSD-04), their optical and electrochemical properties, and their use as photosensitizers in dye-sensitized solar cells (DSSCs). Our theoretical and experimental studies show that adding the second thienothiophene allows for narrowing the bandgap of the molecule and thus ensuring more light harvesting in the visible region. The efficiencies of both CSD-03 (5.46 ± 0.03%) and CSD-04 (5.20 ± 0.03%) are comparable to that of N719 (5.92 ± 0.01%) in translucent DSSCs fabricated with 5 µm-thick TiO2 photoanodes.

Coplanar Donor-π-Acceptor Dyes Featuring a Furylethynyl Spacer for Dye-Sensitized Solar Cells.

Coplanar metal-free organic dyes featuring a furylethynyl spacer with different donor residues (MeO-, MeS-, and Me2N-) have been synthesized. Density functional theory (DFT) calculations predicted that the Me2N- residue would facilitate more effective charge transfer from donor to acceptor than the MeO- and MeS- residues. In agreement with DFT calculations, the dye-sensitized solar cells (DSSCs) fabricated with the Me2N- functionalized dye exhibited the best power conversion efficiency (η), 2.88%. Furthermore, the effect of the furan spacer on the photophysical properties and DSSC parameters are discussed in comparison to a previously reported thiophene counterpart.

Wash-stable, oxidation resistant conductive cotton electrodes for wearable electronics.

Commercial, untreated cotton fabrics have been directly silver coated using one-step electroless deposition and, subsequently, conformally encapsulated with a thin layer of poly(perfluorodecylacrylate) (PFDA) using initiated chemical vapor deposition (iCVD). The surface of these PFDA encapsulated fabrics are notably water-repellent while still displaying a surface resistance as low as 0.2 Ω cm-1, making them suitable for incorporation into launderable wearable electronics. X-ray photoelectron spectroscopy confirms that the PFDA encapsulation prevents oxidation of the silver coating, whereas unencapsulated samples display detrimental silver oxidation after a month of air exposure. The wash stability of PFDA-encapsulated, silver-coated cotton is evaluated using accelerated laundering conditions, following established AATCC protocols, and the samples are observed to withstand up to twenty home laundering cycles without notable mechanical degradation of the vapor-deposited PFDA encapsulation. As a proof-of-concept, PFDA-Ag cotton is employed as a top and bottom electrode in a layered, all-fabric triboelectric generator that produces voltage outputs as high as 25 V with small touch actions, such as tapping.

Impact of Open Reduction on Surgical Strategies for Missed Monteggia Fracture in Children.

PURPOSE: The aims of this study were to review our cases of missed Monteggia fracture treated by open reduction of the radial head with or without ulnar osteotomy and to investigate the indications for open reduction alone in surgical treatment of missed Monteggia fracture. MATERIALS AND METHODS: We retrospectively reviewed 22 patients who presented with missed Monteggia fracture. The patients' mean age at the time of surgery was 7.6 years. The mean interval from injury to surgery was 16.1 months. The surgical procedure consisted of open reduction of the radiocapitellar joint followed by ulnar osteotomy without reconstruction of the annular ligament. The mean period of follow-up was 3.8 years. Radiographic assessment was performed for the maximum ulnar bow (MUB) and the location of the MUB. Clinical results were evaluated with the Mayo Elbow Performance Index and Kim's scores. RESULTS: Five patients underwent open reduction alone, and 17 patients underwent open reduction and ulnar osteotomy. When the MUB was less than 4 mm and the location of the MUB was in the distal 40% of the ulna, we could achieve reduction of the radial head without ulnar osteotomy. The radial head was maintained in a completely reduced position in 21 patients and was dislocated in one patient at final follow-up. CONCLUSION: Open reduction alone can be an attractive surgical option in select patients with missed Monteggia fracture with minimal bowing of the distal ulna. However, ulnar osteotomy should be considered in patients with a definite ulnar deformity.

Proximal femoral osteotomy in Legg-Calvé-Perthes disease using a monolateral external fixator: surgical technique, outcome, and complications.

Although external fixation methods have been described for proximal femoral osteotomy for various etiologies, none are dedicated to a single disease entity. Our study introduces a technique of proximal femoral osteotomy and fixation with a monolateral external fixator system in Legg-Calvé-Perthes disease (LCPD). Twenty-three patients (19 males, four females) with LCPD underwent surgery at our institute between 2004 and 2012. Varus osteotomy (group A, 11 hips) and valgus osteotomy (group B, 12 hips) were performed and the monolateral external fixator system was used. The average age of patients at surgery was 13 years (6-23 years) and the mean follow-up duration was 21 months (12-64 months). The mean angular correction of the varus osteotomy in group A was 20° (10°-28°) and the mean medial displacement was 21% (10-49%). The angular correction of valgus osteotomy in group B was 28° (14°-49°) and lateral displacement was 41% (38-58%). The mean fixation time was 14 weeks (8.4-31 weeks). Complications occurred in nine hips (39.1%) and included pin-tract infections (five), hip abduction contracture (one), nonunions (two), and refracture (one). Our surgical technique provides precise correction and stable fixation with minimal intervention. Therefore, the monolateral external fixator could be considered an acceptable alternative fixation device for the correction of proximal femoral deformities in patients with LCPD. LEVEL OF EVIDENCE: Level IV, case series.

The Effect of Alendronate Loaded Biphasic Calcium Phosphate Scaffolds on Bone Regeneration in a Rat Tibial Defect Model.

This study investigated the effect of alendronate (Aln) released from biphasic calcium phosphate (BCP) scaffolds. We evaluated the in vitro osteogenic differentiation of Aln/BCP scaffolds using MG-63 cells and the in vivo bone regenerative capability of Aln/BCP scaffolds using a rat tibial defect model with radiography, micro-computed tomography (CT), and histological examination. In vitro studies included the surface morphology of BCP and Aln-loaded BCP scaffolds visualized using field-emission scanning electron microscope, release kinetics of Aln from BCP scaffolds, alkaline phosphatase (ALP) activity, calcium deposition, and gene expression. The in vitro studies showed that sustained release of Aln from the BCP scaffolds consisted of porous microstructures, and revealed that MG-63 cells cultured on Aln-loaded BCP scaffolds showed significantly increased ALP activity, calcium deposition, and gene expression compared to cells cultured on BCP scaffolds. The in vivo studies using radiograph and histology examination revealed abundant callus formation and bone maturation at the site in the Aln/BCP groups compared to the control group. However, solid bony bridge formation was not observed at plain radiographs until 8 weeks. Micro-CT analysis revealed that bone mineral density and bone formation volume were increased over time in an Aln concentration-dependent manner. These results suggested that Aln/BCP scaffolds have the potential for controlling the release of Aln and enhance bone formation and mineralization.

Limb Lengthening in Patients with Achondroplasia.

PURPOSE: Although bilateral lower-limb lengthening has been performed on patients with achondroplasia, the outcomes for the tibia and femur in terms of radiographic parameters, clinical results, and complications have not been compared with each other. We proposed 1) to compare the radiological outcomes of femoral and tibial lengthening and 2) to investigate the differences of complications related to lengthening. MATERIALS AND METHODS: We retrospectively reviewed 28 patients (average age, 14 years 4 months) with achondroplasia who underwent bilateral limb lengthening between 2004 and 2012. All patients first underwent bilateral tibial lengthening, and at 9-48 months (average, 17.8 months) after this procedure, bilateral femoral lengthening was performed. We analyzed the pixel value ratio (PVR) and characteristics of the callus of the lengthened area on serial radiographs. The external fixation index (EFI) and healing index (HI) were computed to compare tibial and femoral lengthening. The complications related to lengthening were assessed. RESULTS: The average gain in length was 8.4 cm for the femur and 9.8 cm for the tibia. The PVR, EFI, and HI of the tibia were significantly better than those of the femur. Fewer complications were found during the lengthening of the tibia than during the lengthening of the femur. CONCLUSION: Tibial lengthening had a significantly lower complication rate and a higher callus formation rate than femoral lengthening. Our findings suggest that bilateral limb lengthening (tibia, followed by femur) remains a reasonable option; however, we should be more cautious when performing femoral lengthening in selected patients.

Developmental pattern of the hip in patients with hereditary multiple exostoses.

BACKGROUND: Coxa valga is a common clinical feature of hereditary multiple exostoses (HME). The current study aimed to determine the unique developmental pattern of the hip in patients with HME and evaluate the factors that influence its progression. METHODS: Thirty patients (57 hips) with HME were divided into two groups according to the Hilgenreiner epiphyseal angle (HEA). Twenty-two patients (44 hips) including 13 men and 9 women were assigned to group 1 (HEA <25°), and 8 patients (13 hips) including 3 men and 5 women were assigned to group 2 (HEA ≥25°). The mean age at the initial presentation was 6.0 (4-12) years with 6.8 (4-11) years of follow-up in group 1, and 10.4 (8-13) years with 5.4 (2-9) years of follow-up in group 2. We measured the HEA, neck-shaft angle (NSA), acetabular index (AI), center-edge angle (CEA), and migration percentage (MP) for radiographic evaluation. RESULTS: Among the hips, 50 (87.7%) hips had coxa valga and 27 (47.4%) hips had abnormal MP (42.1% were borderline and 5.3% were subluxated). There was a significant difference in the HEA and NSA between the groups (p < 0.001 and p < 0.05, respectively). The HEA significantly correlated with the development of the NSA and no correlation was found between the HEA and AI, CEA, and MP. CONCLUSIONS: There was a significant relationship between the HEA at the initial presentation and the NSA at skeletal maturity. We should consider guided growth for patients with lower HEA to prevent significant coxa valga deformity with close follow-up.

Self-assembly behavior of alkylated isophthalic acids revisited: concentration in control and guest-induced phase transformation.

The engineering of two-dimensional crystals by physisorption-based molecular self-assembly at the liquid-solid interface is a powerful method to functionalize and nanostructure surfaces. The formation of high-symmetry networks from low-symmetry building blocks is a particularly important target. Alkylated isophthalic acid (ISA) derivatives are early test systems, and it was demonstrated that to produce a so-called porous hexagonal packing of plane group p6, i.e., a regular array of nanowells, either short alkyl chains or the introduction of bulky groups within the chains were mandatory. After all, the van der Waals interactions between adjacent alkyl chains or alkyl chains and the surface would dominate the ideal hydrogen bonding between the carboxyl groups, and therefore, a close-packed lamella structure (plane group p2) was uniquely observed. In this contribution, we show two versatile approaches to circumvent this problem, which are based on well-known principles: the "concentration in control" and the "guest-induced transformation" methods. The successful application of these methods makes ISA suitable building blocks to engineer a porous pattern, in which the distance between the pores can be tuned with nanometer precision.

Assessment of skeletal age in multiple epiphyseal dysplasia.

BACKGROUND: Determining the skeletal age in patients with multiple epiphyseal dysplasia (MED) is essential for predicting the adult height and guiding the timing of limb lengthening, epiphysiodesis, and other surgical procedures. In the present study, we examined the patterns of skeletal age delay using 3 different methods, the Greulich-Pyle (GP) atlas method, the Tanner-Whitehouse 3 (TW3) method using radius-ulna-short bones (RUS) scoring system, and the TW3 method using the carpal bone maturity scoring system. METHODS: Left hand radiographs from 23 patients (age range, 3 to 14 y) with MED were examined to determine the skeletal age. We examined the reliability of the 3 different methods and evaluated the difference between the chronological age and the skeletal age. RESULTS: The interobserver and intraobserver reliabilities were higher with the GP atlas method and the TW3 RUS method compared with the TW3 carpal bone maturity scoring system. There was significant skeletal age delay irrespective of the method used (P<0.01). When we used the TW3 carpal method, the pattern of skeletal age delay was significantly distinct from the other 2 methods. According to the measurement method, there was no statistically significant difference in the developmental skeletal age pattern among the COMP gene group, the MATN3 gene group, and other gene groups. CONCLUSIONS: Our findings indicate that there is a distinct skeletal maturation pattern in patients with MED. The skeletal age is relatively delayed compared with the chronological age irrespective of the measuring method utilized. However, use of either the GP atlas or the TW3 RUS method provided more accurate information on the skeletal development in the patients with MED than that provided by the TW3 carpal bone maturity scoring system. LEVEL OF EVIDENCE: Level I. Diagnostic study.

Humidity effect of domain wall roughening behavior in ferroelectric copolymer thin films.

We have demonstrated that domain switching in ferroelectric copolymer films can be significantly affected by humidity. With increasing relative humidity (RH), we observed larger domains with highly irregular boundaries as a result of lateral spreading of the tip-induced electric field that originates from water adsorption. Fractal dimension study of irregular domains reveals that the fractal dimension is higher in cases where the RH is higher. The results show that the RH is one of the major switching parameters in ferroelectric copolymers, and therefore could allow clear understanding with regard to domain switching behavior in the ferroelectric copolymer films under ambient conditions.

Extent of physeal involvement in Legg-Calvé-Perthes disease.

PURPOSE: The growth plate involvement (GPI) index is reportedly a reliable predictor of final radiographic outcome in Legg-Calvé-Perthes disease (LCPD). We determined whether (1) the GPI index was associated with the lateral pillar classification, (2) the GPI index could predict the final radiographic outcome, and (3) the geometry of proximal femur was affected by presence of physeal involvement. METHODS: We reviewed 47 patients with unilateral LCPD who were treated conservatively. The mean duration of follow-up was 9.5 years (range, five to 13 years). The affected hips were categorized into those with and without physeal involvement. Herring classifications were determined and the GPI indices were estimated at the stage of maximum fragmentation. The Stulberg classification, leg length discrepancy (LLD), articulotrochanteric distance (ATD) index, neck-shaft angle (NSA), neck width and height were determined at skeletal maturity. RESULTS: The GPI indices were lower in Herring groups A and B (p < 0.001) and Stulberg classes I and II (p = 0.002), and these values were increased in the Herring group B/C and C and Stulberg classes III, IV and V. However, the age of onset, LLD and ATD index at skeletal maturity were not associated with the GPI index. The NSA of the affected hips with physeal involvement was significantly different compared to that of unaffected hips (p < 0.001). CONCLUSIONS: The GPI index could be used to determine the extent of physeal involvement in LCPD, and might be considered one of the prognostic values of radiographic development in patients with LCPD who are treated conservatively.

Timing of premature physeal closure in Legg-Calve-Perthes Disease.

PURPOSE: Premature physeal closure of the proximal femoral physis has been reported in Legg-Calve-Perthes Disease (LCPD). However, the timing of its occurrence had not yet been reported. We proposed (1) to determine the timing of premature physeal closure in unilateral LCPD with serial radiographic evaluation, and (2) to evaluate the relationship between the premature physeal closure and Herring classification, leg-length discrepancy (LLD), Stulberg classification, and trochanteric overgrowth. METHODS: We performed a retrospective study with serial radiographs of 27 patients diagnosed with LCPD. The difference in the timing of physeal closure between the hips was calculated. The involved hip was classified according to Herring classification. The LLD and ATD index at latest follow up was measured. The mean values were calculated and statistical comparison of variables was done using the Fisher's exact test. RESULTS: The mean difference of physeal closure at the involved hip compared to the uninvolved side was 3.5 years (range, two to five years). Hips demonstrating premature physeal closure were associated with Herring B/C and C (p = 0.01) and LLD >1 cm (p = 0.02). There is no correlation between Stulberg classification, trochanteric overgrowth and premature physeal closure (p = 0.06 and p = 0.19). CONCLUSIONS: We may expect premature physeal closure of the proximal femoral physis in patients with LCPD to occur 3.5 years earlier than normal hips. Presence of premature physeal closure can be an adjunct diagnostic tool in the prognostication of LCPD outcomes. Future studies directed toward premature physeal closure in LCPD and associated growth disturbances are necessary.

Clinical implication of sagittal translation in lengthening over nail of tibia.

PURPOSE: During the surgery of lengthening over nail (LON), we sometimes observe sagittal translation of proximal tibia (STPT) when the nail is inserted into the canal. We investigated the factors that lead to STPT and its clinical significance. METHODS: We reviewed 35 consecutive patients who underwent bilateral tibial lengthening with LON. The following parameters were assessed to evaluate the factors that can lead to STPT; the level of tibia osteotomy (OT) in sagittal plane, the type of the nail, the nail entry point in sagittal/coronal planes, and the type of the OT. Then, the followings are analyzed to find any possible clinical significance of this phenomenon: the change of posterior proximal tibial angle (PPTA), the cortical healing index, and the translation of the sagittal mechanical axis (SMA) of the lower extremity. RESULTS: The postoperative STPT was 3.04 ± 2.73 mm, and proximal location of the OT in relation to the nail bending point was found to increase STPT. The nail entry point in sagittal/coronal planes and the type of tibia OT had no significant correlations with STPT. It had no significant relations with the PPTA or cortical healing index. It pushed the SMA posteriorly, but the SMA was always anterior to the center of rotation of the knee joint. CONCLUSIONS: Proximal location of the OT in relation to the nail bending point is related to STPT. However, it does not negatively influence cortical healing, posterior tibial slope, or SMA of the lower extremity.

How reliable are standard radiographic measures of the foot and ankle in children with achondroplasia?

BACKGROUND: Radiographic measurements are typically used in achondroplasia (ACH) during correction of lower limb alignment. However, reliabilities for the measurements on weightbearing radiographs of the foot and ankle in patients with ACH have not been described, and the differences between the ACH population and subjects without ACH likewise have not been well characterized; these issues limit the use of studies on this subject. QUESTIONS/PURPOSES: We proposed (1) to measure the inter- and intraobserver reliability of a number of radiographic measures of ankle and foot alignment in an achondroplastic cohort of patients; and (2) to compare our radiographic measurement values with age-matched literature-based normative values. METHODS: Ten radiographic measurements were applied to foot and ankle radiographs of 20 children (40 feet) with ACH (mean age, 10 years; range, 8-16 years). Interobserver and intraobserver reliabilities of these radiographic measurement methods were obtained and expressed by intraclass correlation coefficients (ICCs). The mean values were calculated and compared with the literature-based values. RESULTS: The interobserver reliability was excellent for eight measurements with ICCs ranging from 0.801 to 0.962, except for lateral talo-first metatarsal angle and mediolateral column ratio, which were much lower. The intraobserver reliability was excellent for all 10 radiographic measurements with ICCs ranging from 0.812 to 0.998. Compared with existing literature-based values, all 10 measurements had a significant difference (p < 0.01). CONCLUSIONS: We suggest tibiotalar angle, calcaneal pitch angle, tibiocalcaneal angle, talocalcaneal angle, naviculocuboid overlap, talonavicular coverage angle, metatarsal stacking angle, and AP talo-first metatarsal angle with excellent interobserver and intraobserver reliabilities should be considered preferentially in analysis of foot and ankle alignment in children with ACH.

Can residual leg shortening be predicted in patients with Legg-Calvé-Perthes' disease?

BACKGROUND: Although Legg-Calvé-Perthes' disease (LCPD) is frequently associated with varying degrees of femoral head deformity and leg length discrepancy (LLD), no factors that predict residual shortening have been clearly identified. QUESTIONS/PURPOSES: We attempted to determine whether (1) the extent of femoral head involvement; (2) varus osteotomy; and (3) patient demographic characteristics are associated with LLD at skeletal maturity in patients with LCPD. METHODS: We retrospectively reviewed the records of 168 skeletally mature patients with unilateral LCPD. The mean age at diagnosis was 7 years (range, 2-14 years). The extent of femoral head involvement was determined from the initial radiographs using the Herring lateral pillar and Catterall classifications. LLD was defined as shortening by ≥ 1.0 cm as measured from scanograms. The patient's sex and the treatment modalities used were also recorded. RESULTS: LLD ranging from 10 to 38 mm (mean, 19 mm) occurred in 93 (55%) patients and was associated with the extent of femoral head involvement. Varus osteotomy was not associated with residual shortening. The patient's age at diagnosis did not affect the LLD at skeletal maturity. The strongest predictor of LLD was a lateral pillar classification of B/C or C (odds ratio, 3.5; 95% confidence interval, 1.39-8.79). CONCLUSIONS: The extent of femoral head involvement, but not the patient's age at diagnosis or sex or the treatment modality, can predict the LLD at skeletal maturity in patients with unilateral LCPD.

Role of hybrid monolateral fixators in managing humeral length and deformity correction.

BACKGROUND AND PURPOSE: Humeral lengthening and deformity correction are now being done increasingly for various etiologies. Monolateral external fixators have advantages over traditional Ilizarov circular fixators; they are easy to apply, they are less bulky, and they are therefore more convenient for the patient. We assessed the effectiveness of hybrid monolateral lateral fixators in humeral lengthening and deformity correction. METHODS: We retrospectively reviewed 23 patients (40 humeri) with various pathologies who underwent lengthening-with or without deformity correction using monolateral external fixator-between 2003 and 2008. Mean age at the time of the surgery was 14 (10-22) years. The mean follow-up time was 3.4 (1-7) years. RESULTS: The average duration of external fixator use was 8.3 (6-19) months. The mean lengthening achieved was 8.8 (4-11) cm and percentage lengthening was 49% (19-73). The healing index was 28 (13-60) days/cm. The major complications were refracture in 3 humeri and varus angulation of 2 humeri. The minor complications were superficial pin tract infection (6 segments), transient radial nerve palsy (1 segment), and elbow flexion contracture (5 segments). All complications resolved. INTERPRETATION: Hybrid monolateral fixators can be used for humeral lengthening and deformity correction. The advantage over circular fixators is that they are less bulky and patients can perform their day-to-day activities with the fixator in situ.