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PubMed2001

Endocranial vascular patterns in a familial rabbit model of coronal suture synostosis.

OBJECTIVE: The present study investigates the potential relationship between craniosynostosis and any changes in endocranial vasculature. The hypothesis that crania from rabbits with familial, nonsyndromic coronal suture synostosis and crania from rabbits with experimental immobilization of the coronal suture are associated with altered form of the middle meningeal vessels and dural venous sinuses is tested. DESIGN: Silicone rubber endocasts from 14 adult New Zealand white rabbits (Oryctolagus cuniculus) with familial nonsyndromic coronal suture synostosis (five with bilateral coronal suture synostosis and nine with unilateral coronal suture synostosis) were made to assess middle meningeal vessel and dural venous sinus form. For comparative purposes, endocasts were made from 25 rabbits with normal, patent coronal sutures and 10 rabbits with experimental immobilization of the coronal suture. Impressions of the dural venous sinuses were assessed for depth and width. The area of the confluens of sinuses was also assessed. Impressions of the middle meningeal vessels were assessed for depth, width, and degree of convolution. For width of the dural venous sinuses and area of the confluens of sinuses, comparisons among groups were made with a one-way analysis of variance (ANOVA). For depth of the dural venous sinuses and impressions of the middle meningeal vessels, comparisons among groups were made using a Kruskal-Wallis one-way ANOVA. RESULTS: Crania with familial coronal suture synostosis had significantly (p <.05) reduced posterior dural venous sinus dimensions when compared with both crania from rabbits with experimental immobilization of the coronal suture and rabbits with normal coronal sutures. Crania with both coronal suture synostosis and experimental immobilization had significant increases in dimensions of the middle meningeal vessels relative to normal crania. In addition, casts from rabbits with unicoronal suture synostosis showed marked asymmetry in the dural venous sinuses. CONCLUSIONS: These results support the hypothesis that craniosynostosis is associated with alterations in endocranial vasculature. These changes are most likely a secondary response to synostosis rather than a causal factor and may reflect increased intracranial pressure, decreased intracranial volume, and local accumulations and reductions of cerebrospinal fluid in the posterior region of the skull and immediately deep to the coronal suture.

Analysis of Variance↗
PubMed2001

Altered fibular growth patterns after tibiofibular synostosis in children.

BACKGROUND: Iatrogenic synostosis of the tibia and fibula following an operation on the leg in a child has been reported rarely in the literature, and the effects of this complication on future growth, alignment, and function are not known. This is a retrospective case series, from one institution, of crossunions of the distal parts of the tibia and fibula complicating operations on the leg in children. The purpose is to alert surgeons to this possible complication. METHODS: The senior author identified eight cases of iatrogenic tibiofibular synostosis seen in children since 1985. The patients had various diagnoses and were from the practices of four pediatric orthopaedic surgeons. Synostosis developed in six patients after osteotomies of the distal parts of the tibia and fibula, in one after internal fixation of distal tibial and fibular metaphyseal fractures through a single incision, and in one after posterior transfer of the anterior tibialis tendon through the interosseous membrane combined with peroneus brevis transfer to the calcaneus. Medical records were reviewed, and preoperative and follow-up radiographs were analyzed for changes in the relative positions of the proximal and distal tibial and fibular physes and in the alignment of the ankle. RESULTS: Five patients were symptomatic after crossunion; they presented with prominence of the proximal part of the fibula, ankle deformity, or ankle pain. Three patients were asymptomatic, and a synostosis was identified on routine follow-up radiographs. Intraoperative technical errors caused two of the crossunions; the cause of the others was unknown. Following tibiofibular synostosis, growth disturbances were noted radiographically in every patient. The normal growth pattern of distal migration of the fibula relative to the tibia was reversed, resulting in a decreased distance between the proximal physes of the tibia and fibula as well as proximal migration of the distal fibular physis relative to the distal part of the tibia. Shortening of the lateral malleolus led to greater valgus alignment of the ankle. CONCLUSIONS: Tibiofibular synostosis can complicate an operation on the leg in a child. After crossunion, the normal distal movement of the fibula relative to the tibia is disrupted, resulting in shortening of the lateral malleolus and ankle valgus as well as prominence of the fibular head at the knee. The synostosis also interferes with the normal motion that occurs between the tibia and fibula with weight-bearing, potentially leading to ankle pain.

Ankle Joint↗
PubMedDate not supplied

Synostosis of the ring-small finger metacarpal in Apert acrosyndactyly hands: incidence and treatment.

SUMMARY: This study reports on the incidence of a synostosis between the ring-small metacarpal bases in patients with Apert syndrome and describes a technique to resect the synostosis and insert silicone sheets to improve hand function. Records of 9 patients (18 hands) were evaluated. Average age at follow-up was 9.5 years. Three relationships between the ring-small metacarpals were observed. Type I hands (22%) had no abnormal interconnections; type II hands (33%) possessed a synostosis since birth; type III hands (44%) did not possess a synostosis at birth, but one later developed at average age of 79 months. Total incidence of synostosis was 77%. Five patients underwent excision of the synostosis. At an average of 16 postoperative months, 4 of these patients experienced improvement in hand prehension. In patients with Apert syndrome, resection of abnormal interconnections between the ring-small metacarpals is highly recommended to improve hand prehension based on the high incidence of a synostosis in this region.

Acrocephalosyndactylia↗
PubMed1985

[Synostosis dynamics in human long tubular bones].

More than 8,000 roentgenograms and electroroentgenograms of brachial, ulnar, radiocarpal, coxofemoral, knee, talocrural joints have been studied in persons of both sex at the age from birth up to 25 years. The synostosis degree is appreciated by the six-mark system. The roentgenological data are corroborate histologically. The method of appreciation applied makes it possible to reveal cases of initially forming synostosis long before puberty. Three stages of synostosis process are defined. The first stage--slow increase of the synostosis mark. The second--quick synostosis formation. The third--final stage. According to the stages defined, a comparative analysis of the synostosis process in all metaepiphyseal zones of all long tubular bones, peculiarities of the process depending on the sex are demonstrated. The data on the time, when the points of ossification appear, on the beginning and completion of synostosis process in all metaepiphyseal zones of the long tubular bones are presented.

Adolescent↗
PubMed1996

[Surgery of congenital radio-ulnar synostosis. Technical error and therapeutic strategy].

PURPOSE OF THE STUDY: A clinical feature of surgery in congenital radioulnar synostosis is described. MATERIAL AND METHODS: A eighteen year old right handed woman, was hampered when she works by a left congenital radio ulnar synostosis. Clinical examination showed a left forearm locked in 75 degrees of pronation. Radiographs showed a proximal synostosis. Surgical treatment associated a resection of the synostosis with silastic interposition, resection of the distal end of the ulna, and derotational middle-third osteotomy of the radius. RESULTS: Three months later, the pronosupination was 90 degrees, but an ischemic retraction of the flexor pollicis longus muscle appeared with a non-union of the radius. A second procedure was necessary to put a plate in compression on bone and to release the muscle. Twenty years later, the forearm was locked in neutral pronosupination, without recurrence of synostosis on radiographs. DISCUSSION: Surgical treatment in congenital radio ulnar synostosis associates many problems: indication (often for discomfort), ideal age (more vascular or nervous post operative complications if older), technical (failure of operations with functional aim). CONCLUSION: A review of international litterature allows the authors to suggest a specific management for congenital radio ulnar synostosis.

Adolescent↗
PubMed1996

The differential diagnosis of posterior plagiocephaly: true lambdoid synostosis versus positional molding.

The diagnosis and treatment of posterior plagiocephaly is one of the most controversial aspects of craniofacial surgery. The features of true lambdoid synostosis versus those of deformational plagiocephaly secondary to positional molding are inadequately described in the literature and poorly understood. This has resulted in many infants in several craniofacial centers across the United States undergoing major intracranial procedures for non-synostotic plagiocephaly. The purpose of this study was to describe the detailed clinical, imaging, and operative features of true lambdoid synostosis and contrast them with the features of positional plagiocephaly. During a 4-year period from 1991 to 1994, 102 patients with posterior plagiocephaly were assessed in a large multidisciplinary craniofacial program. During the same period, 130 patients with craniosynostosis received surgical treatment. All patients were examined by a pediatric dysmorphologist, craniofacial surgeon, and pediatric neurosurgeon. Diagnostic imaging was performed where indicated. Patients diagnosed with lambdoid synostosis and severe and progressive positional molding underwent surgical correction using standard craniofacial techniques. Only 4 patients manifested the clinical, imaging, and operative features of unilambdoid synostosis, giving an incidence among all cases of craniosynostosis of 3.1 percent. Only 3 among the 98 patients with positional molding required surgical intervention. All the patients with unilambdoid synostosis had a thick ridge over the fused suture, identical to that found in other forms of craniosynostosis, with compensatory contralateral parietal and frontal bossing and an ipsilateral occipitomastoid bulge. The skull base had an ipsilateral inferior tilt, with a corresponding inferior and posterior displacement of the ipsilateral ear. These characteristics were completely opposite to the findings in the 98 patients who had positional molding with open lambdoid sutures and prove conclusively that true unilambdoid synostosis exists as a specific but rare entity. Awareness of the features of unilambdoid synostosis will allow more accurate diagnosis and appropriate treatment of posterior plagiocephaly in general and in particular will avoid unnecessary surgical intervention in patients with positional molding.

Cranial Sutures↗
PubMed1999

Three-dimensional analysis of craniofacial form in a familial rabbit model of nonsyndromic coronal suture synostosis using Euclidean distance matrix analysis.

OBJECTIVE: Simple craniosynostoses produce predictable morphologies of the cranial vault, with growth deficits in a direction parallel to the synostosed suture and compensatory growth at sutures that are perpendicular to and attached to the synostosed one. In coronal suture synostosis, anteroposterior growth is inhibited, with compensatory growth in a transverse direction. Information on growth patterns and influence on other craniofacial regions are not as clear. This study tested the hypotheses that (1), both juvenile and adult rabbits with familial, nonsyndromic coronal suture synostosis exhibit significant size and shape differences of the entire craniofacial region relative to normal rabbits as a result of altered growth patterns and that (2), shape differences of the calvaria will precede those of the basicranium. DESIGN: Fifty anatomic landmarks were located on 94 New Zealand white rabbit crania. The crania were divided into a juvenile, six-week-old age category (n = 53) and an adult, 18-week-old category (n = 41) in order to assess shape differences at different ages. Each age category was sorted into three groups based on growth at the coronal suture: normal sutural growth, delayed onset synostosis, and complete synostosis. Landmarks were digitized in three-dimensions, and statistical analyses on shape differences were carried out using Euclidean distance matrix analysis (EDMA). RESULTS AND CONCLUSIONS: Results showed that delayed onset synostosis did not produce craniofacial morphology that was different from normal at any age. However, complete synostosis yielded predictable and global craniofacial shape differences at both ages relative to normal skulls, producing an overall shorter, wider cranium with the most markedly compensating regions in a posterosuperior position of the skull. In addition, delayed onset synostosed crania showed no shape differences in the basicranium, relative to normal crania, suggesting primacy of the calvaria in this model of coronal synostosis. However, further investigations are necessary to verify primacy of the calvaria in this model.

Age Factors↗
PubMedDate not supplied

Preoperative morphology and development in sagittal synostosis.

The goal of this study is to characterize the differences between normal cranial morphology and that of patients diagnosed with isolated sagittal synostosis, using three-dimensional (3D) landmark coordinate data collected from computed tomography (CT) scans. This retrospective study uses pre-operative CT images of a sample of children diagnosed with isolated sagittal synostosis (N = 23) and of dry skulls of unaffected children (N = 10). In order to be included in the study, patients had to have a confirmed diagnosis of sagittal synostosis and a pre-operative CT scan of acceptable quality available in digital format. Separation of normal and synostosed individuals on the basis of craniofacial morphology was achieved by applying a principal coordinates analysis to a dissimilarity matrix calculated from the landmark coordinate data. Direct comparison of age-graded samples of normal and synostosed individuals using Euclidean Distance Matrix Analysis enabled localization of the morphological differences between samples. This method was also used to characterize growth patterns of the two samples using cross-sectional data. The parietal bosses were found to be the features that were most influential in separating sagittal synostosis patients from their age-matched normal counterparts. A cross-sectional analysis of growth showed that the specifics of the growth differences between normal and sagittal synostosis individuals changed with the age interval considered. We present direct evidence that the parietal bosses are critical in the differentiation of normal and sagittal synostosis morphology, and indirect evidence of the possible role of the parietal tubers in the etiology of sagittal synostosis.

Child↗
PubMed1998

Internal calvarial bone distraction in rabbits with delayed-onset coronal suture synostosis.

Recent studies have identified a subpopulation of craniosynostotic individuals who exhibit progressive or delayed-onset synostosis and mild craniofacial growth abnormalities. These individuals may be good candidates for nonextirpation, distraction osteogenesis therapy. The present study was designed to test this hypothesis by using internal calvarial bone distraction in a rabbit model with familial delayed-onset craniosynostosis. Data were collected from 159 rabbits: 71 normal controls, 72 with delayed-onset coronal suture synostosis, 8 with delayed-onset coronal suture synostosis and coronal suturectomy, and 8 with delayed-onset coronal suture synostosis and distraction. At 10 days of age, all rabbits had amalgam markers placed on both sides of the frontonasal, coronal, and anterior lambdoidal sutures. At 25 days of age, correction was accomplished through either a 5-mm-wide suturectomy or distraction osteogenesis. An internal distraction appliance was fixed to the frontal and parietal bones and percutaneously and intermittently activated at an average of 0.10 mm/day for 42 days (4.11 mm total). Serial radiographs were taken at 10, 25, 42, and 84 days of age. Results revealed that rabbits with delayed-onset synostosis had significantly (p < 0.01) reduced coronal suture growth rates (0.04 mm/day) compared with the other three groups (0.07 mm/day). Rabbits with suturectomy and rabbits with distraction showed similar coronal suture responses. However, from 42 to 84 days of age, rabbits with distraction showed reduced growth at the vault sutures and abnormal growth patterns in cranial vault width, cranial vault shape, and cranial base angulation compared with the other three groups. Results demonstrated that, although the normal coronal suture growth rate was maintained in rabbits with delayed-onset synostosis using intermittent distraction osteogenesis, normal adult craniofacial structure was not achieved. Such anomalous growth was probably a result of altered growth vectors and compressive forces at adjacent sutures during distraction. These findings suggest that distraction osteogenesis without corticotomy may be a treatment alternative in individuals with progressive, delayed-onset synostosis, but that internal appliances that generate low-level, continuous distractive forces should be investigated and developed.

Animals↗
PubMed2000

Trigonocephaly in rabbits with familial interfrontal suture synostosis: the multiple effects of premature single-suture fusion.

Previous studies from our laboratory have characterized the craniofacial morphology and growth patterns of an inbred strain of rabbits with autosomal dominant coronal suture synostosis. A number of rabbit perinates from this colony have been collected sporadically over a 5-year period with premature interfrontal suture synostosis. The present study describes the very early onset of craniofacial dysmorphology of these rabbits and compares them to similar-aged normal control rabbits. A total of 40 perinatal New Zealand White rabbits were used in the present study. Twenty-one comprised the sample with interfrontal suture synostosis and ranged in age from 27 to 38 days postconception (term = 31 days) with a mean age of 33.53 days (+/-2.84 days). Nineteen rabbits served as age-matched, normal controls (mean age = 33.05 days +/-2.79 days). Lateral and dorsoventral radiographs were collected from each rabbit. The radiographs were traced, computer digitized, and 12 craniofacial measurements, angles, and indices were obtained. Mean measures were compared using an unpaired Student's t-test. All synostosed rabbits were stillborn or died shortly after birth. Grossly, these rabbits exhibited extreme frontal bossing, trigonocephaly with sagittal keeling, and midfacial shortening. No somatic anomalies were noted. Radiographically, rabbits with interfrontal suture synostosis had significantly (P < 0.05) narrower bifrontal widths, shorter cranial vault lengths, kyphotic cranial base angles, and different cranial vault indices (shapes) compared to controls. Results reveal severe and early pathological and compensatory cranial vault changes associated with premature interfrontal suture synostosis in this rabbit model. The 100% mortality rate noted in this condition may be related to the inheritance of a lethal genetic mutation or to neural compression from reduced intracranial volume. Results are discussed in light of current pathogenic hypotheses for human infants with premature metopic suture synostosis.

Animals↗
PubMedDate not supplied

The use of tensor fascia lata interposition grafts for the treatment of posttraumatic radioulnar synostosis.

PURPOSE: There is no agreement on the ideal treatment of traumatic radioulnar synostosis, especially the type of interposition material to be used. The purpose of this study is to report our experience with synostosis resection and interposition of tensor fascia lata grafts. METHODS: A chart review was conducted for all patients treated for posttraumatic radioulnar synostosis between 2000 and 2004. Demographic data, mechanism of injury, length of time to synostosis resection, range-of-motion, patient satisfaction, and postoperative complications were analyzed. RESULTS: Thirteen patients were identified for this study. The mean preoperative pronation was 14 degrees and the mean postoperative pronation was 62 degrees. The mean preoperative supination was 4 degrees and the mean postoperative supination was 62 degrees. The mean follow-up time was 30 months. CONCLUSIONS: These results indicate that synostosis resection with tensor fascia lata graft interposition is an effective technique for the treatment of posttraumatic radioulnar synostosis. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic, Level IV.

Adult↗
PubMed2005

Involvement of the basilar coronal ring in unilateral coronal synostosis.

BACKGROUND: Unilateral coronal synostosis denotes one-sided premature fusion of the frontoparietal suture. However, this is only one component of the coronal hemi-ring that includes the contiguous frontoparietal, frontosphenoidal, and frontoethmoidal sutures. Possible fusion of the basilar sutures in unilateral coronal synostosis is poorly documented. METHODS: The authors retrospectively reviewed the radiographic records of 91 patients with unilateral coronal synostosis who were evaluated in their unit between 1986 and 2003. Fifty-one computed tomography scans were of sufficient quality to adequately assess the basilar sutures. Each suture in the coronal hemi-ring (frontoparietal, frontosphenoid, and sphenoethmoid) was assessed on axial images for evidence of synostosis, extent and location of fusion, and cranial base angulation. The data were analyzed using SAS statistical software (SAS, Cary, N.C.). RESULTS: One frontoparietal ("coronal") suture was fused in all 50 patients. Synostosis was incomplete in 19 patients; specifically, the superior and inferior portions of the frontoparietal suture were patent. Fourteen of the 19 scans showing partial frontoparietal fusion were in infants less than 5 months of age. Scans were grouped according to extent of fusion in the basilar coronal hemi-ring: group I (n = 15), the frontosphenoidal suture was open on the affected side, whereas in group II (n = 36), there was variable synostosis in the lateral portion of the ipsilateral frontosphenoidal suture. Patients in group I were significantly younger than those in group II at the time of computed tomographic study (p < 0.001). Furthermore, group I patients were more likely to have incomplete frontoparietal fusion, as compared with group II (p < 0.001). The frontosphenoidal suture was patent in 100 percent of patients younger than 3 months, in 43 percent of those between 3 and 5 months old, and in 0 percent of patients older than 5 months at the time the scan was obtained. There was also a trend toward a larger cranial base angulation in group II, although this difference was not significant (p = 0.33). Seven patients were syndromic; however, their mean age (207 days) at the time of computed tomography was not statistically different from that of patients without a detectable mutation (188 days), nor did the cranial base angulation differ in this subgroup. CONCLUSIONS: The authors conclude that unilateral coronal fusion begins in the middle of the frontoparietal suture and extends superiorly and inferiorly. There also is age-dependent, progressive involvement of the lateral frontosphenoidal suture between 3 and 5 months of age. Nevertheless, synostotic extension into the basilar coronal hemi-ring is not associated with increased cranial base angulation.

Age Factors↗
PubMed1996

Development of plagiocephaly in rabbits with unicoronal synostosis.

Human unicoronal synostosis results in plagiocephaly of the cranial vault due to predictable compensatory growth patterns of the contralateral coronal, sagittal, and ipsilateral squamosal sutures. The present study describes the development of plagiocephaly and tests compensatory growth predictions in a naturally occurring rabbit model of uncorrected unicoronal synostosis. Cranial vault and sutural growth data were collected from serial x-ray films in 70 normal rabbits and 19 rabbits with congenital unicoronal synostosis from 1.5 to 18 weeks of age. One-way analysis of variance results revealed that rabbits with unicoronal synostosis had significant (p < 0.05) growth inhibition at both coronal sutures and the contralateral frontonasal suture and a significantly wider (p < 0.05) cranial vault compared to controls. Paired Student's t-tests between affected and unaffected sides of the vault in rabbits with synostosis revealed significant (p < 0.05) asymmetry, with ipsilateral coronal sutures growing less than contralateral ones. Gross qualitative examination of the adult brains revealed severe asymmetry and anteroposterior reduction on the ipsilateral side. These results demonstrate that this congenital rabbit model effectively simulates human cranial vault growth predictions from unicoronal synostosis and produces a plagiocephalic morphology.

Age Factors↗
PubMed1983

Cyclophosphamide-induced temporomandibular synostosis.

The study of malformations helps toward a better understanding of normal development, which is of significance to the orthodontist. Experiments in teratology have induced an extensive variety of facial abnormalities, but temporomandibular joint (TMJ) synostosis has never been previously reported. Ten pregnant female rabbits were treated with a daily injection of 50 mg. cyclophosphamide (DNA synthesis inhibitor), from day 11 to day 14, which is the period that precedes formation of the face. The control sample comprised five female rabbits. The fetuses were obtained by cesarean section on day 28 and stained with alizarin. Six of the ten treated female animals produced offspring that had TMJ synostosis. The skull with TMJ synostosis showed a retrognathic mandibular pattern in relation to the maxilla, and the bony trabeculae in the mandibular angle showed a downward orientation instead of the horizontal orientation seen in animals without synostosis. The length of the heads was significantly smaller in the treatment group than in the control group; within the treatment group, the heads with synostosis were significantly smaller than those without synostosis. It could be hypothesized that the cyclophosphamide might have affected intrinsic factors in the temporomandibular mesenchyma; an impairment in the development and function of the mandibular musculature, which is a vital factor in joint development and maintenance, might also have contributed to the genesis of the malformation. The association of immobilization and mandibular hypodevelopment seems to be in agreement with today's theories on maxillofacial growth.

Animals↗
PubMed2001

Neurodevelopment in children with single-suture craniosynostosis and plagiocephaly without synostosis.

The objective of this study was to determine whether children with nonsyndromic craniosynostosis and plagiocephaly without synostosis demonstrated cognitive and psychomotor delays when compared with a standardized population sample. This was the initial assessment of a larger prospective study, which involved 21 subjects with nonsyndromic craniosynostosis (mean age, 10.9 months) and 42 subjects with plagiocephaly without synostosis (mean age, 8.4 months). Each child was assessed using the Bayley Scales of Infant Development-II (BSID-II) for cognitive and psychomotor development before therapeutic intervention (surgery for craniosynostosis and molding-helmet therapy for plagiocephaly without synostosis). The distribution of the scores was divided into four groups: accelerated, normal, mild delay, and significant delay. The distributions of the mental developmental index (MDI) and the psychomotor developmental index (PDI) were then compared with a standardized Bayley's age-matched population, using Fisher's exact chi-square test. Within the craniosynostosis group, the PDI scores were significantly different from the standardized distribution (p < 0.001). With regard to the PDI scores, 0 percent of the subjects in the craniosynostosis group were accelerated, 43 percent were normal, 48 percent had mild delay, and 9 percent had significant delay. In contrast, the MDI scores were not statistically different (p = 0.08). Within the group with plagiocephaly without synostosis, both the PDI and MDI scores were significantly different from the normal curve distribution (p < 0.001). With regard to the PDI scores, 0 percent of the subjects in the group with plagiocephaly without synostosis were accelerated, 67 percent were normal, 20 percent had mild delay, and 13 percent had significant delay. With regard to the MDI scores, 0 percent of the subjects in this group were accelerated, 83 percent were normal, 8 percent had mild delay and 9 percent had significant delay. This study indicates that before any intervention, subjects with single-suture syndromic craniosynostosis and plagiocephaly without synostosis demonstrate delays in cognitive and psychomotor development. Continued postintervention assessments are needed to determine whether these developmental delays can be ameliorated with treatment.

Child Development↗
PubMed2004

Molecular analysis of patients with synostotic frontal plagiocephaly (unilateral coronal synostosis).

Mutations in genes known to be responsible for most of the recognizable syndromes associated with bilateral coronal synostosis can be detected by molecular testing. The genetic alterations that could cause unilateral coronal synostosis are more elusive. It is recognized that FGFR and TWIST mutations can give rise to either bilateral or unilateral coronal synostosis, even in the same family. The authors undertook a prospective study of patients presenting with synostotic frontal plagiocephaly (unilateral coronal synostosis) to Children's Hospital Boston during the period from 1997 to 2000. Mutational analysis was performed on all patients and on selected parents whenever familial transmission was suspected. Intraoperative anthropometry was used in an effort to differentiate those patients in whom a mutation was detected from those in whom it was not. The anthropometric measures included bilateral sagittal orbital-globe distance, inter medial canthal distance, and nasal angulation. Macrocephaly and palpebral angulation were also considered possible determinants. There was a 2:1 female preponderance in 47 patients with synostotic frontal plagiocephaly. Mutations were found in eight of 47 patients: two patients with different single-amino-acid changes in FGFR2, three patients with FGFR3 Pro250Arg, and three patients with TWIST mutations. Another patient had craniofrontonasal syndrome for which a causative locus has been mapped to chromosome X, although molecular testing is not yet available. Two features were strongly associated with a detectable mutation in patients with synostotic frontal plagiocephaly: asymmetrical brachycephaly (retrusion of both supraorbital rims) and orbital hypertelorism. Other abnormalities in the craniofacial region and extremities were clues to a particular mutation in FGFR2, FGFR3, TWIST, or the X-linked mutation. Neither macrocephaly nor degree of nasal angulation nor relative vertical position of the lateral canthi correlated with mutational detection. An additional four patients in this study had either unilateral or bilateral coronal synostosis in an immediate relative and had anthropometric findings that predicted a mutation, and yet no genetic alteration was found. This suggests either that the authors' screening methods were not sufficiently sensitive or that perhaps there are other unknown pathogenic loci. Nevertheless, molecular testing is recommended for infants who have unilateral coronal synostosis, particularly if there are the anthropometric findings highlighted in this study or an otherwise suspicious feature in the child or a parent. Infants with either an identified or a suspected mutation usually need bilateral asymmetric advancement of the bandeau and may be more likely to require frontal revision in childhood.

Adult↗
PubMed1998

Congenital radioulnar synostosis. Study of a series of 37 children and adolescents.

The authors report a retrospective series of 37 patients (49 forearms) with congenital radioulnar synostosis followed and treated at Raymond Poincaré University Hospital. This disease is rare, but much more frequent than post-traumatic or humeroradial synostosis. A genetic factor was incriminated in 25% of patients. The clinical study was based on 31 files (40 forearms) with a subjective finding of hypermobility of the wrist in all patients. Shortening of the ipsilateral upper extremity < or = 2 cm was also observed in one third of patients, and a defect of elbow extension was observed in 35%. The radiological study, conducted on 30 files (38 forearms), confirmed the existence of several degrees of fusion within the synostosis and revealed an associated radiological abnormality in 92% of cases. The only valid correlation revealed was between the degree of fusion of the synostosis and the presence of a morphological abnormality of the radial head (r = 0.87), hence the proposal of a new radiological classification essentially based on this element. Functional adaptation was excellent in the majority of cases. The authors propose two main indications for surgery: hyperpronation > or = 90 degrees and bilateral synostosis; in both cases, the disability must be very severe. The operative technique used appeared to be very well adapted to this disease: "reed" radial osteotomy and transverse ulnar osteotomy. No complications or relapses were observed in six operated patients with a mean follow-up of 10 years, with a mean loss of derotation of only 5 degrees.

Child↗
PubMed1996

Distal tibiofibular synostosis after ankle fracture. A 14-year follow-up study.

Over an eight-year period up to 1983, a total of 322 consecutive patients had operations for ankle fractures; 176 were Weber type B and 128 type C. We were able to review 230 of these patients after a mean follow-up of six years (1 to 11) including 128 with Weber B and 102 with Weber C fractures. We used an ankle score which combined symptoms and clinical and radiological findings, with a maximum score of 100 points. The mean score for all 230 was 92 (68 to 100). Fifteen of these patients had developed a distal synostosis between the tibia and fibula, three after a Weber B and 12 after a Weber C fracture. In 13 of these 15 ankles the synostosis had been visible radiologically within three months of the operation. In the other two there had been radiologically visible calcification at the three-month follow-up. In 1993, we were able to review nine of the 15 patients with synostosis using the same scoring system. At a mean follow-up of 14 years (12 to 18) the mean score for those with synostosis was 91 (71 to 100), much the same as this group's previous score and the mean score of the whole group of operated patients. We conclude that distal tibiofibular synostosis after ankle fracture usually causes few symptoms and does not generally require any treatment.

Aged↗