3D-printed Cutting Guides for Lower Limb Deformity Correction in the Young Population.

BACKGROUND: Three-dimensional (3D) virtual surgical planning technology has advanced applications in the correction of deformities of long bones by enabling the production of 3D stereolithographic models, patient-specific instruments and surgical-guiding templates. Herein, we describe the implementation of this technology in young patients who required a corrective osteotomy for a complex 3-plane (oblique plane) lower-limb deformity. PATIENTS AND METHODS: A total of 17 patients (9 males, average age 14.7 y) participated in this retrospective study. As part of preoperative planning, the patients' computerized tomographic images were imported into a post-processing software, and virtual 3D models were created by a segmentation process. Femoral and tibial models and cutting guides with locking points were designed according to the deformity correction plan. They were used for both planning and as intraoperative guides. Clinical parameters, such as blood loss and operative time were compared with a traditional surgical approach group. RESULTS: All osteotomies in the 3D group were executed with the use intraoperative customized cutting guides which matched the preoperative planning simulation and allowed easy fixation with prechosen plates. Surgical time was 101±6.2 minutes for the 3D group and 126.4±16.1 minutes for the control group. The respective intraoperative hemoglobin blood loss was 2.1±0.2 and 2.5+0.3 g/dL.Clinical and radiographic follow-up findings showed highly satisfactory alignment of the treated extremities in all 3D intervention cases, with an average time-to-bone union (excluding 2 neurofibromatosis 1 patients) of 10.3 weeks (range 6 to 20 wk). CONCLUSION: The use of 3D-printed models and patient-specific cutting guides with locking points improves the clinical outcomes of osteotomies in young patients with complex bone deformities of the lower limbs. LEVEL OF EVIDENCE: Level III.

Changes in the femoral osteotomy level coefficient and neck shaft angle during limb lengthening with an intramedullary magnetic nail.

BACKGROUND: The intramedullary magnetic IM nail enables bone graduated distraction. Proximal femur osteotomies for ante grade IM lengthening nails have a tendency towards varus-procurvatum malalignment. We examined the effect of the level of the osteotomy and of trochanteric versus piriformis entry points on the neck shaft angle (NSA) during lengthening with the PRECICE IM magnetic nail. METHODS: A novel parameter, the osteotomy level coefficient (OLC), was introduced as a guide to determine the level of an osteotomy at the proximal femur. The OLC was defined as the ratio between the distances from the tip of the greater trochanter to the osteotomy divided by the full length of the femur. A retrospective review of all femoral lengthening procedures with the PRECICE ante grade IM lengthening nail between 2013 and 2018 was carried out. RESULTS: 31 femurs were lengthened in 30 patients (16 males and 14 females, mean age at surgery years 17.1. The average amount of lengthening was 4.4 cm. Trochanteric entry points were used in 24 femurs, and piriformis entry points in seven femurs. The OLC values ranged from 0.16 to 0.34 (average 0.25). The average follow-up period was 10.15 months. The distraction index average 10.5 days/cm (Range 8.6-11.9), Consolidation index 32.1 days/cm (14.3-51.9). The average post-operative NSA was significantly reduced from 133.5º to 128.5º [t (31) = 5.57, p = 0.000]. There was no correlation between the OLC and the change in the NSAs. The trochanteric entry point showed a greater tendency to reduce the NSA (Mdif = - 6, SD = 4.8) compared to the piriformis entry point (Mdif = - 0.86, SD = 2.27) [t (31) = -3.96, p = 0.001]. CONCLUSION: Proximal femur lengthening with the PRECICE IM nail significantly reduced the NSA and might cause Varus deformity. The level of osteotomy by OLC did not influence the amount of NSA reduction. The trochanteric entry points have a greater tendency to reduce the NSA compared to the piriformis entry points.

Ponseti treated idiopathic clubfoot - outcome predictive factors in the test of time: analysis of 500 feet followed for five to 20 years.

PURPOSE: To investigate a set of risk factors on the outcome of Ponseti treated idiopathic clubfeet (ICF). METHODS: This study was approved by the institutional review board. A retrospective analysis of prospectively gathered data over a 20-year period, at a single dedicated clubfoot clinic. Records of 333 consecutive infants with 500 ICF were analyzed. Initial Pirani score, number of casts, need for tenotomy, foot abduction brace compliance and functional score had been documented. The need for surgery after initial correction was the outcome measure. All children were followed by the same team throughout the study period. Descriptive statistics, chi-squared and multivariate analysis were performed. RESULTS: In total, 82 children (24%) with 119 feet (23.8%) were operated on, with 95.1% of feet being operated up to the age of nine years. There was a significant correlation between the Pirani score at presentation and the number of surgical procedures (chi-squared = 79.32; p < 0.001). Achilles tenotomy was done in 94.8% of patients. Pirani score of > 4.5 before casting was strongly associated with increased surgical risk (odds ratio = 1.95). When six to eight cast changes were needed, surgical prospect was 2.9 more, increasing to 11.9 when nine or more casts were needed. CONCLUSION: Foot severity and number of cast changes were the strongest predictors for future surgery. Estimation of the risk of deformity recurrence after initial correction may help in tailoring a cost-effective personal treatment and follow-up protocol. Personalized focused protocol will help patients and caregivers and will reduce expenses. LEVEL OF EVIDENCE: Level II - prognostic study.

The efficacy of guided growth as an initial strategy for Blount disease treatment.

PURPOSE: The aim of this study was to evaluate the success of guided growth by temporal hemiepiphysiodesis of the lateral proximal tibia as a first line treatment option for Blount disease. METHODS: This was a retrospective multicentre study conducted in five centres, covering data on 55 limbs in 45 patients, with an average follow-up of 24.5 months following plate insertion. Preoperative alignment analysis was compared with three measurements taken postoperatively. The normalization of the mechanical medial proximal tibia angle (mMPTA) was defined as the primary outcome measure. RESULTS: Mean age at surgery was 9.5 years. Average preoperative mMPTA was 77°. On average, at 24.5 months post-surgery, mMPTA was 86.33°, while 43/55 limbs (78.18%) have achieved normalization (mMPTA 85° to 90°). Average rate of correction was 1° per month. When grouping the children as infantile (11 limbs), juvenile (12 limbs) and adolescent (32 limbs), operated on before the age of four years, between four and ten years and after the age of ten years, respectively, 63.63%, 66.67%, 87.5% have completed correction of deformity during the follow-up period. Interestingly, the femoral component of the deformity has achieved correction as well in 33/55 limbs (64%). CONCLUSION: Hemiepiphysiodesis is an effective first line treatment for Blount disease. Overall success rate is good but varies according to child's age. Adolescent Blount has the best chance of achieving full correction while same treatment is less effective in infantile Blount.Level of evidence: IV.

RPL13 Variants Cause Spondyloepimetaphyseal Dysplasia with Severe Short Stature.

Variants in genes encoding ribosomal proteins have thus far been associated with Diamond-Blackfan anemia, a rare inherited bone marrow failure, and isolated congenital asplenia. Here, we report one de novo missense variant and three de novo splice variants in RPL13, which encodes ribosomal protein RPL13 (also called eL13), in four unrelated individuals with a rare bone dysplasia causing severe short stature. The three splice variants (c.477+1G>T, c.477+1G>A, and c.477+2 T>C) result in partial intron retention, which leads to an 18-amino acid insertion. In contrast to observations from Diamond-Blackfan anemia, we detected no evidence of significant pre-rRNA processing disturbance in cells derived from two affected individuals. Consistently, we showed that the insertion-containing protein is stably expressed and incorporated into 60S subunits similar to the wild-type protein. Erythroid proliferation in culture and ribosome profile on sucrose gradient are modified, suggesting a change in translation dynamics. We also provide evidence that RPL13 is present at high levels in chondrocytes and osteoblasts in mouse growth plates. Taken together, we show that the identified RPL13 variants cause a human ribosomopathy defined by a rare skeletal dysplasia, and we highlight the role of this ribosomal protein in bone development.

Preoperative Planning of Orthopedic Procedures using Digitalized Software Systems.

The progression from standard celluloid films to digitalized technology led to the development of new software programs to fulfill the needs of preoperative planning. We describe here preoperative digitalized programs and the variety of conditions for which those programs can be used to facilitate preparation for surgery. A PubMed search using the keywords "digitalized software programs," "preoperative planning" and "total joint arthroplasty" was performed for all studies regarding preoperative planning of orthopedic procedures that were published from 1989 to 2014 in English. Digitalized software programs are enabled to import and export all picture archiving communication system (PACS) files (i.e., X-rays, computerized tomograms, magnetic resonance images) from either the local working station or from any remote PACS. Two-dimension (2D) and 3D CT scans were found to be reliable tools with a high preoperative predicting accuracy for implants. The short learning curve, user-friendly features, accurate prediction of implant size, decreased implant stocks and low-cost maintenance makes digitalized software programs an attractive tool in preoperative planning of total joint replacement, fracture fixation, limb deformity repair and pediatric skeletal disorders.

Radiographic Indicators of Surgery and Functional Outcome in Ponseti-Treated Clubfeet.

BACKGROUND: Evaluation of the results of treatment for clubfoot by the Ponseti technique is based on clinical and functional parameters. There is a need to establish universally recognized quantitative measurements to compare, better understand, and more precisely evaluate therapeutic outcome. METHODS: Nine angles were measured on standard radiographs of 145 children with idiopathic clubfeet treated between 2000 and 2010 with the Ponseti method. The average follow-up was 6.3 years. The need for additional surgery and the functional outcome was correlated to the radiologic measurements. RESULTS: Three radiologic parameters were identified as having significant (P ≤ .001) predictive value. The lateral tibiocalcaneal angle with the ankle at maximal dorsiflexion measuring fixed equinus was larger in the preoperated group (77 ± 12 degrees) compared to the nonoperated group (67 ± 14 degrees). Functional outcome was better with smaller angles. The lateral talocalcaneal angle with the ankle at maximal dorsiflexion measuring hindfoot rigidity was smaller (29 ± 8 degrees) in the preoperated group compared to the nonoperated group (35 ± 9 degrees). Functional outcome was better with larger angles. The lateral talo-first metatarsal angle with the ankle at maximal plantarflexion measuring foot cavus was larger in the preoperated group (31 ± 10 degrees) compared to the nonoperated group (22 ± 11 degrees), whereas functional outcome did not correlate with this angle. CONCLUSIONS: The lateral view with the foot in maximal dorsiflexion was found to be the most significant and useful view to detect abnormality in Ponseti-treated clubfeet. In our practice now, we are using only this view in order to reduce the radiation exposure to the child. LEVEL OF EVIDENCE: Level III, retrospective case series.

Correction of Cubitus Varus After Pediatric Supracondylar Elbow Fracture: Alternative Method Using the Taylor Spatial Frame.

BACKGROUND: Cubitus varus is a well-reported complication of supracondylar fracture of the humerus potentially resulting in cosmetic problems, impaired function, and malpractice claims. Traditional methods of correcting malunited distal humeral fractures involve complex osteotomies that have a high complication rate, require a large exposure, and challenging fixation. We present a technique of gradual correction using a percutaneous transverse osteotomy and 3 dimensional correction with a Taylor Spatial Frame. METHODS: This was a retrospective, IRB-approved study of 12 patients between 2006 and 2010, with cubitus varus after a malunited pediatric supracondylar fracture. The average age at initial injury was 5+8 years. The average age of the patients at surgery was 8+8 years. We measured technical (radiographic parameters and complications), functional (clinical carrying angle, range of motion, QuickDash), and satisfaction domain (questionnaire) outcomes at a minimum follow-up of 6 months. RESULTS: The osteotomy healed in all patients by 10 weeks after the index surgery. The mean external fixator time was 10 weeks. The average preoperative and postoperative humeroulnar angles for the affected elbow were 23 degrees varus and 5.8 degrees valgus, respectively. This was statistically significant (P<0.001). The mean preoperative and postoperative carrying angles were 22 degrees of varus and 5.8 degrees of valgus. This was statistically significant (P<0.001). The results of the QuickDash assessment showed that patients were doing very well with regard to the use of their upper extremity. The mean symptom/disability score was 0.80. No major complications or neurovascular complications were encountered. Overall satisfaction with the procedure was high. CONCLUSIONS: The Taylor Spatial Frame as used in this case series provides the experienced surgeon another safe, accurate, and reliable method to correct cubitus varus after pediatric supracondylar fracture. We used in 7 of our 12 cases, a previously unreported pattern of distal humeral pin fixation that allows for a very distal metaphyseal osteotomy, close to the deformity apex. This is a biplanar delta configuration that straddles the olecranon fossa and is appropriate for both children and adults. LEVEL OF EVIDENCE: Level IV.

Selective laser trabeculoplasty in uncontrolled pseudoexfoliation glaucoma.

BACKGROUND AND OBJECTIVE: To assess the efficacy and safety of selective laser trabeculoplasty (SLT) in uncontrolled pseudoexfoliation glaucoma (PEXG). PATIENTS AND METHODS: Fifty-seven eyes (57 patients) with uncontrolled PEXG and intra-ocular pressure (IOP) greater than 23 mm Hg underwent SLT. All received ophthalmic evaluation preoperatively and at intervals postoperatively. IOP was measured at 1 hour, 1 day, 1 week, and 1, 3, 6, and 12 months postoperatively. During follow-up, patients were treated with topical anti-glaucoma medications as necessary. RESULTS: One year postoperatively, mean IOP in all patients decreased from 26.01 ± 2.5 to 17.8 ± 2.8 mm Hg (31.5%; P < .001). Mean medications per patient decreased from 2.8 to 2.3. Complications included conjunctival redness and infection within 1 day postoperatively in 30 eyes (67%). One hour after SLT treatment, an increase in IOP greater than 5 mm Hg was detected in two eyes (3.5%) and resolved within 24 hours with topical medication. CONCLUSION: SLT is safe and effective in patients with PEXG.

Lowering of IOP by echothiophate iodide in pseudophakic eyes with glaucoma.

PURPOSE: We retrospectively investigated the intraocular pressure (IOP)-lowering effects of echothiophate iodide (EI) as adjunctive treatment for pseudophakic glaucoma patients who were receiving maximal medical therapy (MMT), including the newer class of medications, i.e., prostaglandin analogs, alpha-2 agonists, and topical carbonic anhydrase inhibitors. METHODS: The medical records of all pseudophakic glaucoma patients (24 eyes) under MMT who received supplementary EI 0.125% between January 2002 and December 2003 were reviewed. IOP data and number of medications before, during and after EI treatment were collected. RESULTS: Adding EI to MMT further reduced IOP in 23 of 24 eyes. Three eyes (12.5%) showed some lowering of IOP, but not enough to be considered controlled (IOP above the target pressure). The mean baseline IOP of 30.4 +/- 8.2 mmHg (median 29 mmHg) dropped at final follow-up (11.2 +/- 3.9 months) to 16.6 +/- 4.2 mmHg (median 17 mmHg, p < 0.0001) in all eyes that had showed effective pressure reduction upon the addition of EI. Their IOP rose to 27.7 +/- 8.0 mmHg (median 28 mmHg, p < 0.001) when EI was discontinued because of commercial non-availability. IOP reduction was > or =20% in 18 (75%) eyes and > or =30% (a mean decrease of 16.7 +/- 8.3mmHg) in 15 eyes (63%). Four eyes (16.6%) required a trabeculectomy despite EI supplement. Five eyes were re-challenged with EI when a small amount was released for sale: their IOP of 26.6 +/- 7.1 mmHg after the first EI discontinuation had dropped to 16.4 +/- 4.3 mmHg (p < 0.0001) and rose to 29.6 +/- 7.1 mmHg when EI was again discontinued. The recorded EI-associated side effects were increased miosis in all eyes and headache (8/24 patients), neither of which were reasons for discontinuation of the drug in any patient. CONCLUSION: EI substantially decreased the IOPs in pseudophakic glaucoma eyes receiving maximal medical therapy, including the newer class of medications. This drug may be the last resort for post-cataract advanced glaucoma patients and may obviate the need for filtering surgery among the very elderly.

Intra- and interobserver reliability analysis of digital radiographic measurements for pediatric orthopedic parameters using a novel PACS integrated computer software program.

BACKGROUND: The between-observer reliability of repeated anatomic assessments in pediatric orthopedics relies on the precise definition of bony landmarks for measuring angles, indexes, and lengths of joints, limbs, and spine. We have analyzed intra- and interobserver reliability with a new digital measurement system (TraumaCad Wizard™). METHODS: Five pediatric orthopedic surgeons measured 50 digital radiographs on three separate days using the TraumaCad system. There were 10 anterior-posterior (AP) pelvic views from developmental dysplasia of the hip (DDH) patients, 10 AP pelvic views from cerebral palsy (CP) patients, 10 AP standing view of the lower limb radiographs from leg length discrepancy (LLD) patients, and 10 AP and 10 lateral spine X-rays from scoliosis patients. All standing view of the lower limb radiographs were calibrated by the software to allow for accurate length measurements, using as reference a 1-inch metal ball placed at the level of the bone. Each observer performed 540 measurements (totaling 2,700). We estimated intra- and interobserver standard deviations for measurements in all categories by specialists and nonspecialists. The intraclass correlation coefficient (ICC) summarized the overall accuracy and precision of the measurement process relative to subject variation. We examined whether the relative accuracy of a measurement is adversely affected by the number of bony landmarks required for making the measurement. RESULTS: The overall ICC was >0.74 for 13 out of 18 measurements. Accuracy of the acetabular index for DDH was greater than for CP and relatively low for the center-edge angle in CP. Accuracy for bone length was better than for joint angulations in LLD and for the Cobb angle in AP views compared to lateral views for scoliosis. There were no clinically important biases, and most of the differences between specialists and nonspecialists were nonsignificant. The correlation between the results according to the number of bony landmarks that needed to be identified was also nonsignificant. CONCLUSIONS: Digital measurements with the TraumaCad system are reliable in terms of intra- and interobserver variability, making it a useful method for the analysis of pathology on radiographs in pediatric orthopedics.

[Current management of idiopathic clubfoot].

Idiopathic clubfoot, one of the most common problems in pediatric orthopaedics, is characterized by a complex three-dimensional deformity of the foot. The treatment of clubfoot is controversial and continues to be so. Since nonsurgical management was thought not to yield adequate correction and a durable result, most children with idiopathic clubfoot have undergone surgery with extensive posteromedial and lateral release. However, surgical management caused residual deformity, stiffness, and pain in some children. Therefore, the favorable long-term results with the Ponseti and French methods of nonsurgical management have garnered interest. Today extensive surgical treatment is no longer necessary in more then 90% of congenital clubfeet. This review aims to assess the different methods of clubfoot treatment used over the years in light of an evolving understanding of the pathoanatomy of the deformity and also clarify factors that allow a safe, logical approach to clubfoot management.

Treatment of severe late-onset Perthes' disease with soft tissue release and articulated hip distraction: revisited at skeletal maturity.

PURPOSE: Late-onset Perthes' disease is diagnosed after 9 years of age. Conservative treatment and conventional surgical techniques have limited ability to reduce the pressure in the joint or change the shape of the femoral head. We used a combination of soft tissue release and joint distraction with a hinged mono-lateral external fixator for these patients. Ten of our patients reached skeletal maturity and were evaluated. METHODS: Clinical assessment included: Harris hip score, hip range-of-motion (ROM), limb length discrepancy, and the Oxford hip questionnaire for pain and function. Radiographic assessment included: Sharp transverse acetabular inclination, the uncoverage percentage, the epiphyseal index before surgery (modified Eyre-Brook), at frame removal, and, at last follow-up, the epiphyseal quotient (of Sjovall) and the Stulberg classification. RESULTS: Our study included eight boys and two girls (mean age at surgery 12.3 years, range 9.4-15.1, mean age at last follow-up 18.1 years, range 15.2-22.8). The mean follow-up was 5.7 years (range 4.3-7.8). The mean Harris hip score was 86.3/100 (range 48.5-96); one patient had <85 points. The hip ROM was slightly limited in most patients, and seven patients had limb shortening between 1-4 cm. The mean Oxford hip questionnaire score was 17.4/60 (range 12-31). The mean Sharp transverse acetabular inclination of the affected side was 42 degrees (range 36-54) compared to 39 degrees for the unaffected side (P = 0.045). The mean uncoverage percentage was 37% (range 27-47) compared to 20% for the unaffected side (P = 0.017). The mean epiphyseal index was 0.71 (range 0.31-0.92) before surgery, 0.79 (range 0.50-0.93) at frame removal (P = 0.012), and 0.72 (range 0.51-0.89) at last follow-up (P = 0.646). The epiphyseal quotient for the eight unilateral cases was 0.72 (range 0.49-0.91), and the Stulberg classification was type III for three cases and type IV for seven. CONCLUSION: Patient satisfaction for function and pain following the combined procedure was good. Radiographic parameters did not change significantly. This should be regarded as a salvage procedure.

[Selective laser trabeculoplasty treatment for medication-refractory open angle glaucoma].

BACKGROUND: Selective laser trabeculoplasty (SLT) is a new method to reduce intraocular pressure in eyes with primary open angle glaucoma. The laser parameters are set to selectively target pigmented trabecular meshwork (TM) cells without damage to the adjacent non-pigmented tissue. PURPOSE: A clinical retrospective study was conducted to evaluate the 12 months results of SLT in the treatment of medically uncontrolled open angle glaucoma. PATIENTS AND METHODS: During the period March to September 2004, the authors performed a SLT in 50 patients (50 eyes) with open angle glaucoma uncontrolled on maximally tolerated medical therapy. Treatment was carried out with a frequency-doubled, Q-switched Nd:YAG laser 532 nm.(Selectra 7000 Laser Coherent, Inc., Palo Alto,CA). Approximately 85 to 90 non-overlapping laser spots were placed over 180 degrees of the trabecular meshwork at energy levels ranging from 0.6 to 1.4 mJ per pulse. In patients who required additional SLT therapy, the untreated 180 degrees was treated. During the follow-up period, patients were treated with antiglaucoma medications as required. The success rates were defined as decreases in intraocular pressure (IOP) of 3 mmHg or more with no additional medications, laser, or glaucoma surgery. RESULTS: The mean IOP reduction from baseline 6 months after treatment was 21% and 20% after 12 months. The success rates were 66% after 6 months and 55% after 12 months. Four eyes (8%) did not respond to SLT. One hour after SLT, an increase in IOP of more than 5 mm Hg was detected in 5 eyes (10%). Seven patients (14%) required additional SLT. CONCLUSIONS: SLT is efficient in lowering IOP in medication-refractory open angle glaucoma. It should be considered in such patients when surgery is contraindicated or refused.

Early experience with the Ponseti method for the treatment of congenital idiopathic clubfoot.

BACKGROUND: The preferred conservative treatment for congenital idiopathic clubfoot deformity remains a controversial issue. OBJECTIVES: To compare the outcomes of two groups of CICF patients who underwent two different treatment protocols. METHODS: The study cohort included 72 infants treated in our hospital from August 1998 to December 2002. Group 1 comprised 40 infants (61 clubfeet) who were treated by a traditional method (a modification of the Kite and Lovell technique), and group 2 consisted of 32 infants (48 clubfeet) treated with the Ponseti technique. Both groups were similar in age, gender and severity of the deformity (Dimeglio scoring system). RESULTS: After an average follow-up of 54.9 months (range 44-68), 35 (57%) clubfeet in group 1 required surgical intervention and 27 (44%) clubfeet had a residual deformity at last follow-up. In the Ponseti group, 45 (94%) clubfeet were fully corrected at last follow-up (average 29.2 months, range 16-45) while 3 (6%) clubfeet had residual deformity and required surgery. Achilles tendon tenotomy was performed with no complications in 47 clubfeet (in group 2) at an average age of 2.4 months (range 2-4 months). CONCLUSIONS: Even after a relatively short follow-up period, our success rate with the Ponseti approach already appears to be significantly higher and to bear fewer complications than the traditional treatment, in agreement with the results published by other medical centers. We now endorse the Ponseti technique of conservative manipulative treatment for congenital idiopathic clubfoot in our department.

Two regions in the N-terminal domain of ionotropic glutamate receptor 3 form the subunit oligomerization interfaces that control subtype-specific receptor assembly.

The N-terminal domain (NTD) of alpha-amino-3-hydroxy-5-methylisoxazolepropionate (AMPA) and kainate glutamate receptors plays an important role in controlling subtype specific receptor assembly. To identify NTD subdomains involved in this process we generated AMPA glutamate receptor 3 (GluR3) mutants having intra-NTD substitutions with the corresponding regions of the kainate receptor GluR6 and tested their ability to form functional heteromers with wild-type subunits. The chimeric design was based on the homology of the NTD to the NTD of the metabotropic GluR1, shown to form two globular lobes and to assemble in dimers. Accordingly, the NTD was divided into four regions, termed here N1-N4, of which N1 and N3 correspond to the regions forming lobe-1 and N2 and N4 to those forming lobe-2. Substituting N1 or N3 impaired functional heteromerization but allowed protein-protein interactions. Conversely, exchanging N2 or N4 preserved functional heteromerization, although it significantly decreased homomeric activity, indicating a role in subunit folding. Moreover, a deletion in GluR3 corresponding to the hotfoot mouse mutation of the glutamate receptor delta2, covering part of N2, N3, and N4, impaired both homomeric and heteromeric oligomerization, thus explaining the null-like mouse phenotype. Finally, computer modeling suggested that the dimer interface, largely formed by N1, is highly hydrophobic in GluR3, whereas in GluR6 it contains electrostatic interactions, hence offering an explanation for the subtype assembly specificity conferred by this region. N3, however, is positioned perpendicular to the dimer interface and therefore may be involved in secondary interactions between dimers in the assembled tetrameric receptor.

A combined vertical and horizontal pelvic osteotomy approach for repair of bladder exstrophy: the Dana experience.

BACKGROUND: Bladder exstrophy is a severe congenital defect that requires a multidisciplinary treatment approach. Soft tissue repair may be successful during the first few days after birth, but a combination of pelvic osteotomies and bladder reconstruction is necessary later in life. The combination of externally fixed anterior and posterior osteotomies has biomechanical advantages over previous techniques for achieving primary bladder closure. OBJECTIVES: To describe our experience with a combined vertical and horizontal pelvic osteotomy approach for the repair of bladder exstrophy. METHODS: Four children underwent bladder exstrophy closure; the mean age at surgery was 19 months (range 9-33 months)... We stabilized the osteotomies with a small Synthes AO external fixator, 4.0 mm rod diameter. RESULTS: All four patients had successful bladder repair with no dehiscence; two of them achieved partial continence, and bladder neck reconstruction is planned for the other two. Three of the four patients sustained neurologic injury; two completely recovered, and the third continues to suffer from right drop foot. The average follow-up was 39 months (range 10-60 months). CONCLUSIONS: Vertical and horizontal pelvic osteotomies stabilized by external fixator and bladder repair is an effective treatment for bladder exstrophy.

Treatment of severe late onset Perthes' disease with soft tissue release and articulated hip distraction: early results.

Sixteen children with late onset Perthes' disease were surgically treated at an average age of 12 years 1 month (9 years 4 months to 15 years) by soft tissue release and articulated hip distraction. Two patients had additional diagnosis of Down syndrome and one suffered from geleophysic epiphyseal dysplasia. Fifteen hips were graded Catterall IV and Herring C and one hip was graded Catterall III Herring B. On preoperative arthrograms, 14 patients had a saddle-shape subluxating femoral head with hinge abduction. The distraction discontinued when Shenton line was corrected. The fixation lasted 4-5 months. At a mean follow-up of 2 years 7 months (1-5 years), an improvement of hip range of motion was found in all patients. Hip joint arthrograms upon removal of the fixator showed disappearance of the saddle-shape femoral head in 10 of the 14 patients with this deformation. Shenton line breakage improved from 7.6 mm to 2.1 mm at last follow-up. The epiphyseal index improved by 14%. The average pain score on an analog scale dropped from a preoperative 7.0 to 1.6 at last follow-up (filled in by patients or parents in case of Down syndrome). Separate analysis of data from the group having only Perthes disease (13 children) showed better results. These preliminary data suggest that soft tissue release combined with unloading of the femoral head and restoration of joint space can improve the function and epiphyseal height.