Latent metabolic bone disease, skeletal dysplasia and other conditions related to low bone formation among 38 patients with subtrochanteric femoral fractures: a retrospective observational study.

Subtrochanteric femoral fracture is rare and intractable due to the possible association with low bone formation. Retrospective analysis of 38 patients with subtrochanteric femoral fractures revealed that four patients suffered from disorders related to low bone formation and there were specific treatments for two of them. PURPOSE: The main aim of this study was to detect latent metabolic bone diseases and skeletal dysplasia associated with low bone formation among patients with morphologic atypical femoral fracture (AFF). A second aim was to evaluate the frequency of recognized risk factors, such as antiresorptive agents, glucocorticoids, and age. METHODS: Clinical information was retrospectively analyzed among 38 Japanese patients who were admitted to the Department of Orthopedic Surgery and Spinal Surgery and the Division of Emergency and Critical Care Medicine at the University of Tokyo Hospital with diagnoses of subtrochanteric fractures between February 2012 and March 2022. RESULTS: Among 38 patients (including 30 females), 21 patients were aged 75 and over. Ten patients had past oral glucocorticoid use, and 18 had past antiresorptive agent use. Two patients were diagnosed with hypophosphatemic osteomalacia after the development of fractures. One patient was suspected to be a carrier of a loss-of-function variant of alkaline phosphatase, biomineralization associated (ALPL), and one other patient had previously been genetically diagnosed with pycnodysostosis. Among four patients with a diagnosis or suspicion of these metabolic bone diseases and skeletal dysplasia, four had past clinical fractures, two had past subtrochanteric femoral fractures, and two had subtrochanteric femoral fractures on both sides. CONCLUSION: If clinicians encounter patients with morphologic AFF, latent diseases related to low bone formation should be carefully differentiated because appropriate treatment may prevent delayed union and recurrent fractures. Additionally, it may be desirable to exclude these bone diseases in advance before initiating long-term use of antiresorptive agents in osteoporotic patients by screening with serum alkaline phosphatase levels to reduce the risk of morphologic AFF.

Pycnodysostosis: Characteristics of teeth, mouth and jaws.

OBJECTIVES: To describe the clinical and radiographic oro-dental characteristics of patients with pycnodysostosis (PDO). MATERIALS & METHODS: A short interview and clinical examination of seven patients with PDO were performed as well as assessment of the temporomandibular joints and masticatory muscles using the diagnostic criteria for temporomandibular disorders, DC-TMD form. A full set of records were taken including photos and intraoral scan. Finally, existing cone beam computed tomography (CBCT) images and radiographs were also studied. RESULTS: All patients presented with bimaxillary micrognathia, five had a convex profile, and two had a straight profile. In addition, posterior open bite, Angle Class III molar relation with accompanying anterior crossbite and a grooved median palate were common findings. No patient showed symptoms of temporomandibular disorder (TMD) apart from some clicking. Finally, the main radiographic findings were the obtuse mandibular angle, the frontal bossing, the elongation of the coronoid/condylar process and the presence of hypercementosis with obliterated pulp chambers. CONCLUSION: The examined patients with PDO were characterized by dental crowding, malocclusion (anterior crossbite, posterior open bite), hypercementosis, obliterated pulp chambers and deviations in mandibular morphology. In conclusion, patients with PDO have a specific need for dental and orthodontic monitoring with focus on crowding and posterior open bite. The patients will benefit from a long-term orthodontic plan including extractions.

Obstructive sleep apnoea in pycnodysostosis: A three-dimensional upper airway analysis.

AIM: To assess the upper airway (UA) morphology in patients with pycnodysostosis with a 3D analysis, compare results with normative data and investigate the correlation of the total volume (TV) with other UA morphology variables. MATERIALS AND METHODS: Cone beam computed tomography (CBCT) images of eight Danish patients with pycnodysostosis (4 males and 4 females with a mean age of 31.8 years, SD: 16.3 years) were analyzed using Mimics® (Materialise® ) and compared with a sex- and age-matched control group (6 males and 8 females with a mean age of 33.6 years, SD: 18.6 years). RESULTS: The distance from the tip of the epiglottis (E) to the Frankfurt horizontal plane (Fp) was significantly shorter in the pycnodysostosis group (P < .042). Regarding the cross-sectional measurements, at the 'maximum constriction' (P < .005), the 'upper airway limit' (P < .001) and the 'lower airway limit' (P < .035) cross-sections were significantly smaller in the pycnodysostosis group. The volumes 'nasopharynx' (P < .002) and 'total airway' (TV) (P < .01) were also significantly smaller. CONCLUSION: Patients with pycnodysostosis have a reduced total airway as well as nasopharyngeal volume compared with matched controls. Additionally, they have a reduced cross-sectional area in the upper and lower borders of the UA, and the area of maximum constriction is also reduced. These factors might explain the high prevalence of obstructive sleep apnoea in pycnodysostosis. Total airway is positively correlated with total length and cross-sections at all levels including the maximum constriction area as well as the anteroposterior dimension at the upper and lower airway borders.

The genotypic and phenotypic spectrum of pycnodysostosis in Saudi Arabia: Novel variants and clinical findings.

Pycnodysostosis is characterized by short stature, osteosclerosis, acro-osteolysis, increased tendency of fractures, and distinctive dysmorphic features. It is a rare autosomal recessive disease caused by biallelic CTSK mutations. The clinical details of 18 patients from Saudi Arabia were reviewed. Short stature, osteopetrosis, acro-osteolysis, and distinctive facial dysmorphism were documented in all cases. Our results highlight the significant complications associated with this disease. The large anterior fontanelle is one of the cardinal signs of this disease; however, half of our patients had small fontanelles and a quarter had craniosynostosis, which caused optic nerve compression. Sleep apnea was of the major complications in three patients. Bone fracture can be a presenting symptom, and in our patients it mainly occurred after the age of 3 years. Bone marrow suppression was seen in a single patient of our cohort who was misdiagnosed initially with malignant osteopetrosis. In this study, we also describe two novel (c.5G > A [p.Trp2Ter], c.538G > A [p.Gly180Ser]) and two reported (c.244-29 A > G, c.830C > T [p.Ala277Val]) CTSK mutations. Our results indicate that the recurrent intronic variant, c.244-29 A > G is likely to be a founder mutation, as it was found in 78% (14/18 patients) of our cohort belonging to the same tribe.

Three-dimensional analysis of craniofacial morphology in patients with pycnodysostosis.

OBJECTIVE: To perform a 3D cephalometric analysis of the craniofacial characteristics of patients with pycnodysostosis and compare this with a matched control group. SETTING AND SAMPLE POPULATION: This cross-sectional descriptive study assessed eight CBCTs obtained in patients with pycnodysostosis (4 males, 4 females, mean age: 31.8 years). MATERIALS AND METHODS: Eight Danish patients with pycnodysostosis were seen at the University's Orthodontic Clinic. All CBCTs were analysed using the Mimics 21.0 software (Materialise®, Belgium) and compared with a control group (6 males, 8 females, mean age: 33.6 years). RESULTS: Interclass correlation coefficient showed excellent intra-rater reliability (> 0.93). All measurements in the 3D cephalometric analysis revealed statistical significance (P < .05) when compared with controls. Patients with pycnodysostosis generally had significantly smaller maxilla in the transverse (P < .001), sagittal (P < .002) and vertical (P < .001) dimensions. Their mandibles were also smaller vertically (P < .001) and in length (P < .001). Gonial angle was significantly larger than controls (P < .001), while mandibular volumes were considerably smaller (P < .001). CONCLUSION: Patients with pycnodysostosis have significantly smaller jaws in the vertical, sagittal and transverse dimensions compared with controls. Furthermore, the gonial angle was significantly larger, while the volume of the mandible was significantly smaller.

Sleep-disordered breathing in children with pycnodysostosis.

Upper airway obstruction is a common feature in pycnodysostosis and may cause obstructive sleep apnea (OSA). The aim of our study was to analyze sleep-disordered breathing and respiratory management in children with pycnodysostosis. A retrospective review of the clinical charts and sleep studies of 10 consecutive children (three girls and seven boys) with pycnodysostosis seen over a time period of 10 years was performed. Six patients had severe OSA and/or nocturnal hypoventilation and were started on continuous positive airway pressure (CPAP) as a first treatment at a median age of 3.4 ± 2.6 years, because of the lack of indication of any surgical treatment. Three patients could be weaned after several years from CPAP after spontaneous improvement (two patients) or multiple upper airway surgeries (one patient). Three patients had upper airway surgery prior to their first sleep study with two patients still needing CPAP during their follow-up. Only one patient never developed OSA. Patients with pycnodysostosis are at a high risk of severe OSA, underlying the importance of a systematic screening for sleep-disordered breathing. Multidisciplinary care is mandatory because of the multilevel airway obstruction. CPAP is very effective and well accepted for treating OSA.

Management of chronic suppurative osteomyelitis in a patient with pycnodysostosis.

Pycnodysostosis is a rare bone dysplasia that causes changes in the facial skeleton. Osteomyelitis is common in patients with this syndrome, and, among the gnathic bones, the mandible is the most commonly affected. This case report describes the treatment of a 46-year-old woman with pycnodysostosis that was associated with chronic suppurative osteomyelitis of 5 years' duration. The patient had no intraoral focus of infection or history of tooth extraction that would explain the clinical findings of pain and a left-sided submandibular fistula. After the patient received 8 days of antibiotic therapy consisting of ceftriaxone and metronidazole, surgical access was achieved through the left submandibular region, and biopsy and curettage of the lesion and excision of the associated fistula were performed. At the 2-year follow-up examination, there was no evidence of lesion recurrence.

Pycnodysostosis: Natural history and management guidelines from 27 French cases and a literature review.

Pycnodysostosis is a lysosomal autosomal recessive skeletal dysplasia characterized by osteosclerosis, short stature, acro-osteolysis, facial features and an increased risk of fractures. The clinical heterogeneity of the disease and its rarity make it difficult to provide patients an accurate prognosis, as well as appropriate care and follow-up. French physicians from the OSCAR network have been asked to fill out questionnaires collecting molecular and clinical data for 27 patients issued from 17 unrelated families. All patients showed short stature (mean = -3.5 SD) which was more severe in females (P = .006). The mean fracture rate was moderate (0.21 per year), with four fractures in total average. About 75% underwent at least one surgery, with an average number of 2.1 interventions per patient. About 50% required non-invasive assisted ventilation due to sleep apnea (67%). About 29% showed psychomotor difficulties and 33% needed a school assistant or adapted schooling. No patient had any psychological evaluation or follow-up. Molecular data were available for 14 families. Growth hormone administration was efficient on linear growth in 40% of cases. We propose several axis of management, such as systematic cerebral MRI for Chiari malformation screening at diagnosis and regular psychological follow-up.

Multiple Fractures and Impaired Bone Fracture Healing in a Patient with Pycnodysostosis and Hypophosphatasia.

Pycnodysostosis (PYCD) is a rare recessive inherited skeletal disease, characterized by short stature, brittle bones, and recurrent fractures, caused by variants in the Cathepsin K encoding gene that leads to impaired osteoclast-mediated bone resorption. Hypophosphatasia (HPP) is a dominant or recessive inherited condition representing a heterogeneous phenotype with dental symptoms, recurrent fractures, and musculoskeletal problems. The disease results from mutation(s) in the tissue non-specific alkaline phosphate encoding gene with reduced activity of alkaline phosphatase and secondarily defective mineralization of bone and teeth. Here, we present the first report of a patient with the coexistence of PYCD and HPP. This patient presented typical clinical findings of PYCD, including short stature, maxillary hypoplasia, and sleep apnoea. However, the burden of disease was caused by over 30 fractures, whereupon most showed delayed healing and non-union. Biochemical analysis revealed suppressed bone resorption and low bone formation capacity. We suggest that the coexistence of impaired bone resorption and mineralization may explain the severe bone phenotype with poor fracture healing.

Genetic study of eight Egyptian patients with pycnodysostosis: identification of novel CTSK mutations and founder effect.

This is the first Egyptian study with detailed clinical and orodental evaluation of eight patients with pycnodysostosis and identification of four mutations in CTSK gene with two novel ones and a founder effect. INTRODUCTION: Pycnodysostosis is a rare autosomal recessive skeletal dysplasia due to mutations in the CTSK gene encoding for cathepsin K, a lysosomal cysteine protease. METHODS: We report on the clinical, orodental, radiological, and molecular findings of eight patients, from seven unrelated Egyptian families with pycnodysostosis. RESULTS: All patients were offspring of consanguineous parents and presented with the typical clinical picture of the disorder including short stature, delayed closure of fontanels, hypoplastic premaxilla, obtuse mandibular angle, and drum stick terminal phalanges with dysplastic nails. Their radiological findings showed increased bone density, acro-osteolysis, and open cranial sutures. Mutational analysis of CTSK gene revealed four distinct homozygous missense mutations including two novel ones, c.164A>C (p. K55T) and c.433G>A (p.V145M). The c.164A>C (p. K55T) mutation was recurrent in three unrelated patients who also shared similar haplotype, suggesting a founder effect. CONCLUSION: Our findings expand the mutational spectrum of CTSK gene and emphasize the importance of full clinical examination of all body systems including thorough orodental evaluation in patients with pycnodysostosis.

Traumatic cervical spine injuries in a patient with pycnodysostosis.

Pycnodysostosis is a rare hereditary disease, characterized by systemic bone sclerosis. Susceptibility to long bone fractures is characteristic, whereas vertebral fractures are extremely rare. We report a case of a 21-year-old man with a past history of pycnodysostosis and spontaneous leg fractures who was admitted in hospital for a neck pain after a banal fall. Radiological examination revealed C1-C2-C3 posterior arch fractures with a C3-C4 left articular fracture dislocation. A surgical stabilization was decided but refused by the patient. To the best of our knowledge, this is the first publication that reports pycnodysostosis with cervical spine traumatic staged injuries.

Pycnodysostosis: the disease of Henri de Toulouse-Lautrec.

Pycnodysostosis or Maroteaux-Lamy syndrome is a genotypic bone disorder, with autosomal recessive inheritance, individualized by Lamy and Maroteaux in 1962. It is characterized by diffuse condensation of the skeleton with thickening of the cortex and narrowing of the medullary cavity. This condensation is reminiscent of the one observed in Albers-Schönberg disease, which differs essentially in dysmorphism of the skull (no closure of fontanelles, gaping sutures, hypoplasia of the lower jaw with open mandibular angle) and extremities (hypoplasia or osteolysis of the phalanges). The patients have a short stature, short hands and feet, and malformed nails. The first scientifically correct diagnosis was made by Dr. G. Séjournet who, under the guidance of his teacher Professor J.-A. Lièvre, performed extensive research and diagnosed Henri de Toulouse-Lautrec with achondroplasia-related dwarfism. This article describes pycnodysostosis and reports the life of the painter Henri de Toulouse-Lautrec who died from the disease.

The role of cathepsin K in oral and maxillofacial disorders.

Cathepsin K (CTSK) was thought to be a collagenase, specifically expressed by osteoclasts, and played an important role in bone resorption. However, more and more research found that CTSK was expressed in more extensive cells, tissues, and organs. It may not only participate in regulating human physiological activity, but also be closely related to a variety of disease. In this review, we highlight the relationship between CTSK and oral and maxillofacial disorders on the following three aspects: oral and maxillofacial abnormities in patients with pycnodysostosis caused by CTSK mutations, oral and maxillofacial abnormities in Ctsk(-/-) mice, and the role of CTSK in oral and maxillofacial diseases, including periodontitis, peri-implantitis, tooth movement, oral and maxillofacial tumor, root resorption, and periapical disease.

Orthopaedic disorders of pycnodysostosis: a report of five clinical cases.

PURPOSE: Pycnodysostosis is a rare autosomal recessive genetic disorder usually diagnosed at an early age. The few previously published case series have generally focused on maxillofacial manifestations and genetic considerations. The purpose of this study was to evaluate the clinical characteristics and differential diagnosis of pycnodysostosis focusing on its orthopaedic manifestations, which have been poorly described in the literature. METHODS: We evaluated clinical and radiographic characteristics of five patients with pycnodysostosis. RESULTS: Three male and two female patients were included in the study. One patient had consanguineous parents and two had a family history of pycnodysostosis. One patient was of normal height; four with short stature underwent growth hormone treatment. Most patients had bone fractures. All had typical cranial and orofacial manifestations, partial dysplasia of the terminal phalanges and increased bone density. Aplastic acromial ends and spondylolysis were not seen in any patient. Some patients had genu valgus, ankle valgus or sleep apnea; two required tympanic drains for serous otitis media. Two patients experienced nonunion. CONCLUSIONS: Short stature is a consistent feature of pycnodysostosis that can be treated with growth hormone. To our knowledge, serous otitis media, nonunion and other orthopaedic manifestations have not been previously described in pycnodysostosis patients. Intramedullary nailing osteosynthesis can be difficult in these patients because of skeletal sclerosis; therefore, other surgical options should be considered. Nonunion is common in this population. Pycnodysostosis is a poorly described disease, but clinicians should be aware of its potential manifestations in order to appropriately diagnose, manage and follow-up patients.

Primary osteolysis syndromes: beware of difficult airway.

BACKGROUND: Primary osteolysis syndromes represent a number of rare conditions characterized by destruction and resorption of bone that is unrelated to neoplasia, infection, or trauma. AIM: To characterize the periprocedural course of patients with primary osteolysis syndrome undergoing procedures that require anesthesia care. METHODS: The medical records database from our institution was searched from 1976 to 2013 to identify patients with primary osteolysis syndromes who received anesthesia care. We reviewed demographic characteristics, comorbidities, and perioperative course of patients with different forms of primary osteolysis. A systematic review of the literature was performed to identify reports describing the anesthetic management of patients with these conditions. RESULTS: We identified 11 patients with a primary osteolysis syndrome who received 111 anesthetics. The patients' ages at the time of surgery ranged from 3 to 62 years. Difficult airway management was a common finding. On preoperative examination, difficulty with endotracheal intubation was predicted in 8 of 11 patients. Three patients had preexisting tracheostomies. One patient required multiple awake fiberoptic intubations. Another two patients where successfully intubated early in life via direct laryngoscopy, but eventually required awake fiberoptic intubations as the disease process caused progressive distortion of airway structures. Intraoperative complications were absent. In the postoperative period, three patients required prolonged mechanical ventilation due to airway swelling, respiratory failure, and infection. CONCLUSIONS: Airway management may be challenging in patients with primary osteolysis syndromes. Because the osteolytic process advances with aging and craniofacial dysmorphism may progressively worsen, the airway should always be reassessed before surgery with an appropriate strategy for potentially difficult intubation. In all patients with primary osteolysis, a potential for pathologic fracture must be considered and careful intraoperative positioning is warranted.

Upper airway surgery of obstructive sleep apnea in pycnodysostosis: case report and literature review.

Pycnodysostosis is an autosomal recessive disorder due to a mutation in the cathepsin K gene, which causes a decrease of the bone turnover; a review of the literature suggests that pycnodysostosis is frequently associated with severe respiratory obstruction, which needs surgical treatment. The aim of this paper is to describe the surgical treatment of a 3½-year-old girl affected by Pycnodysostosis complicated by a severe sleep-related respiratory disorder. The surgical treatment, consisting of adenotonsillectomy and palatoplasty, resulted in a striking amelioration of respiratory parameters and increased posterior airway space, and allowed the patient to avoid tracheotomy while awaiting for maxillo-mandibular surgery.

Challenges in the orthodontic treatment of a patient with pycnodysostosis.

Pycnodysostosis is a rare, autosomal recessive syndrome characterized by osteosclerosis, brittle bones, stunting, and significant craniofacial changes. The objective of this study was to report a case of a 6-year-old patient with pycnodysostosis orthodontically treated and followed up until age 10 years and to discuss the risk factors, options for orthodontic treatment, and limitations involving this type of treatment, which has not yet been performed. Prevention through counseling and periodic follow-up visits is essential in eliminating factors that predispose patients to infections and fractures. New studies are necessary to establish safe and efficient orthodontic treatment plans.

Clinico-Radiological Perspectives of Pycnodysostosis - A Rare Case Series.

Pycnodysostosis is an inherited autosomal recessive disorder characterized by dysplasia of the skeletal system. It occurs in any human races with no disparity in gender or age predilection. The disease is diagnosed at a young age owing to the frequent fragile bone fractures. Craniofacial and dental manifestations may overlap with those of other craniofacial dysostosis; therefore, precise knowledge is essential in differential diagnosis as it may affect the treatment outcome. Here, we report three cases with typical clinical and radiological features, among which one presented with osteomyelitis of the mandible.

Pycnodysostosis: Clinical Insights From Two Siblings.

Pycnodysostosis is a rare autosomal recessive bone disorder caused by mutations in the cathepsin K (CTSK) gene, characterized by increased bone density, short stature, and skeletal fragility. This study reports on two siblings from a consanguineous marriage, observed at the Mohammed VI University Hospital in Oujda, Morocco. Both patients presented with typical symptoms, including craniofacial dysmorphism and skeletal abnormalities. Radiographic findings confirmed increased bone density and acro-osteolysis. The cases highlight the importance of early and accurate diagnosis, comprehensive management to address the broad spectrum of clinical manifestations, and genetic counseling to inform family planning and manage the risk of recurrence in familial pycnodysostosis.

Clinical and radiographic characteristics of pycnodysostosis: A systematic review.

Purpose: Pycnodysostosis (PYCD), an autosomal recessive syndrome, is characterized by an imbalance in bone remodeling that produces various clinical and radiographic craniofacial manifestations. This review represents a systematic examination of these manifestations, as well as oral features associated with PYCD. Materials and Methods: A systematic review was conducted across 8 databases from February to March 2023. The search strategy focused on studies reporting cases of PYCD that examined the clinical and radiographic craniofacial and oral characteristics associated with this syndrome. Results: The review included 84 studies, encompassing a total of 179 cases of PYCD. More than half of the patients were female (55.3%), and the mean age was 14.7 years. Parental consanguinity was reported in 51.4% of the cases. The most common craniofacial clinical manifestation was a prominent nose, observed in 57.5% of cases. Radiographically, the most frequently reported craniofacial characteristics included the presence of an obtuse mandibular angle (84.3%) and frontal cranial bosses (82.1%). Clinical and radiographic examinations revealed oral alterations, with micrognathia present in 62.6% of patients and malocclusion in 59.2%. Among dental anomalies, tooth agenesis was the most commonly reported, affecting 15.6% of patients. Conclusion: Understanding the clinical and radiographic craniofacial features of PYCD is crucial for dental professionals. This knowledge enables these clinicians to devise effective treatment plans and improve patient quality of life.