Achondroplastic Dwarfs Research Articles

Fracture neck of femur in severe coxa-vara – Challenging management in an Achondroplasia patient

Achondroplasia is a skeletal dysplasia of autosomal dominant inheritance. Fibroblast growth factor receptor 3 mutation at p16.3 locus of chromosome 4 leads to inhibition of sub-chondral growth. Middle aged achondroplastic patient with left fracture neck of femur following a fall of heavy object. It was a challenging case because of coxa-vara and meticulous templating is needed. 38 year old male sustained fracture neck of left femur in severe coxa-vara. Closed reduction with 16 mm partially threaded cannulated cancellous screw perpendicular to native neck- shaft angle. At regular follow up, mild lysis was seen around the screw and implant removal was done. Now with neck of femur non-union, walking full weight bearing with walker. The future course included excision arthroplasty or custom made prosthesis. Achrondroplasia characterised by defects in en-chondral bone formation leading to retarded cartilage growth. Literature search on peri-articular fracture management showed peadiatric disatal femur fracture fixed with percutaneous screws. In adult, neck of femur fracture is managed by percutaneous screw, DHS or prosthesis. Due to altered geometry of proximal femur DHS and Prosthesis was deferred.Early failure of CC screws in our case is due to perpendicular placement of screws which increased strain due to altered bio-mechanics. Achondroplastic dwarfs live a normal life. They are prone to peri-articular fractures because of anatomical variations. We wanted to highlight the difficulties and importance of pre-op planning and implant choice of fracture fixation in an adult achondroplasia patient.

Mesenchymal stem cells as adjuvant therapy for limb lengthening in achondroplasia.

Staged leg lengthening allows achondroplastic dwarfs to reach nearly normal height, but it takes long periods of external fixation and it can be burdened by delayed unions. Between 2009 and 2013, eight achondroplastic dwarfs showed delayed unions in the callus formation during femoral lengthening stages in our institute. We performed in-situ injections of bone marrow-derived stem cell concentrates. Patients underwent monthly clinical and radiographic assessment for determination of the healing rate. All eight patients showed an improvement in the regenerated bone, with an average healing index of 23.1 days/cm (range: 18.7-23.8 days/cm). The complete recovery of the delayed consolidation took on an average of 5.2 months (range: 2-10 months). The use of cellular therapy in these patients could represent an innovative application.

78. Coronary bypass using bilateral internal mammary arteries in an achondroplast

Coronary bypass grafting for ischemic heart disease in achondroplastic dwarfs is very rare. Shortage of veins and sometimes, inadequate vein quality can cause difficulties during surgery. Only two achondroplastic cases were reported in literature that underwent coronary bypass surgery, in which the left internal mammary artery and vein grafts were used. To the best of our knowledge using bilateral internal mammary arteries in such patients was not reported. We report here a 55 years old male achondroplastic dwarf who had triple vessels coronary disease that underwent successful coronary bypass surgery using bilateral mammary arteries. Anatomic and surgical challenges in achondroplasia are highlighted

Safety of Spinal Anesthesia in a Patient with Achondroplasia for Cesarean Section

Controversial reports exist regarding the administration of spinal anesthesia in achondroplastic dwarfs regarding safety, dose, drug choice, in obstetric patients. Bony characteristics such as vertebral anomalies, lordosis and lumbar scoliosis, limited mouth opening and cervical spine instability make the administration of anesthesia to these patients truly a challenge. Here we demonstrate that low dose meperidine and bupivacaine spinal anesthesia in an achondroplastic parturient for cesarean section, was administered successfully after careful evaluation, consideration of risks, and awareness of potential complications.

Anatomic Considerations for Radical Retropubic Prostatectomy in an Achondroplastic Dwarf

This is the first report of a radical retropubic prostatectomy (RRP) in an achondroplastic dwarf. We highlight the pelvic anatomy, precluding laparoscopic or robotic prostatectomy, and making open surgery extremely difficult. We review relevant literature regarding general, urological, and orthopedic abnormalities of achondroplasia (ACH) and present a clinical case. No reports of RRP in achondroplastic dwarfs exist, with only one case of an abandoned RRP due to similar pelvic anatomy in a patient with osteogenesis imperfecta. Significant lumbar lordosis found in ACH results in a short anteroposterior dimension, severely limiting access to the prostate. We present a case of a 62-year-old achondroplastic dwarf who had Gleason 3+4 disease on transrectal ultrasound-guided biopsy in four from 12 cores. Surgery was difficult due to narrow anteroposterior pelvic dimension, but achievable. Histological analysis revealed multifocal prostate cancer, with negative surgical margins and no extraprostatic extension. RRP in ACH patients, although possible, should be approached with caution due to the abnormal pelvic dimensions, and discussions regarding potential abandonment of surgery should be included during informed consent. This case highlights the preoperative use of computed tomography to assist in the surgical planning for patients with difficult pelvic anatomy.

Cortical plasticity following surgical extension of lower limbs

Human cortical plasticity has been studied after peripheral sensory alterations due to amputations or grafts, while sudden ‘quasi-physiological’ changes in the dimension of body parts have not been investigated yet. We examined the cortical reorganization in achondroplastic dwarfs submitted to progressive elongation (PE) of lower limbs through the Ilizarov technique. This paradigm is ideal for studying cortical plasticity because it avoids the perturbation connected with deafferentation and reafferentation. Somatosensory evoked-potentials (SEP) and fMRI studies were performed before and after PE during foot and knee stimulation, above and below the surgical fracture. A body schema test was also performed. Following PE, cortical modifications were observed in the primary somatosensory cortex for foot stimulation and in higher order somatosensory cortices for foot and knee. The former modifications tended to decrease 6 months after the elongation ending, whereas the latter tended to persist. Results are interpreted in terms of cortical adaptation mediated by temporary disorganization.

Midface Distraction to Alleviate Upper Airway Obstruction in Achondroplastic Dwarfs

Abstract Objective: The use of midface distraction in patients with achondroplasia and upper airway obstruction secondary to midface hypoplasia has not been reported. In this report, we review the treatment of two patients with severe midface hypoplasia and obstructive sleep apnea secondary to achondroplasia using midface distraction osteogenesis. Design, Setting, and Patients: Two patients with achondroplastic dwarfism and midface hypoplasia with airway obstruction were treated in a tertiary referral center for craniofacial disorders. Results and Conclusions: Both patients had their tracheostomies decannulated after midface distraction of 25 mm. Midface distraction osteogenesis is useful to alleviate upper airway obstruction from midface hypoplasia seen in achondroplasia.

Bilateral humeral lengthening in achondroplasia.

Twenty humeral lengthenings were done on 10 achondroplastic dwarfs using the Ilizarov circular fixator. There were five female and five male patients from 6 years 11 months to 17 years 8 months of age (mean, 12 years 10 months) at the time of the operation. Mean length obtained was 7.8 cm (range, 3.5 cm-10 cm). External fixation time ranged from 105 days to 368 days (mean, 221 days). Healing index averaged 30 days/cm (27 days/cm when two patients with radial nerve palsy were excluded). Two half pins in one patient required replacement. Two humeral fractures occurred, one while in the fixator and the other after removal of the apparatus. Transient radial nerve palsy developed during lengthening in two patients, and lengthening was discontinued. Symptoms of radial nerve palsy resolved completely in both patients, but one patient required an additional surgery to explore the radial nerve for persistent paresthesia of the forearm. Although preexisting loose shoulders deteriorate during lengthening and sometimes cause pain and discomfort, they always resolve spontaneously as lengthening proceeds. Bilateral humeral lengthening was very effective for improving function and overall proportion in patients with achondroplasia.

Is management of anesthesia in achondroplastic dwarfs really a challenge?

Study Objective: To review our eight-year anesthetic experience with achondroplastic patients. Design: Retrospective study. Setting: University hospital. Patients: 15 achondroplastic patients who underwent 53 surgical procedures of orthopedic surgery between 1987 and 1994. Interventions: Anesthetic technique, drugs, number of incidents, and complications in the intraoperative and postoperative period were recorded. Measurements and Main Results: Adequate premedication before the transfer to the operating room was very useful to reduce anxiety and increase cooperation. Inhalation induction was well tolerated and allowed easy peripheral venous cannulation. Only one patient presented difficulties during intubation (on two occasions). In the other patients, we found small difficulties only during ventilation with a face mask, which was easily corrected by modifying the position of the patient and/or inserting an oropharyngeal airway. No adverse effect was identified for any particular anesthetic drug or technique used. Conclusions: Although the characteristic deformities of achondroplastic patients can impede the management of anesthesia, in our study we found no special difficulties. Airway complications did not occur. Thus, no specific optimal anesthetic regimen can be recommended.

LIMB LENGTHENING IN CHILDREN WITH ACHONDROPLASIA. DIFFERENCES BASED ON GENDER

Twelve achondroplastic dwarfs underwent serial limb lengthening during childhood. All had repeated bilateral simultaneous elongation of their lower limbs. The height of these patients was plotted on growth curves for children with achondroplasia. The end results were evaluated after all patients reached skeletal maturity. Growth acceleration was seen in male patients with achondroplasia, but no such effect was seen in females. The female patients lost several centimeters as calculated from their predicted final height based on their preoperative growth curve and the centimeters gained by mechanical distraction. The authors' recommendation is to start limb elongation of male patients with achondroplasia at the age of 8 years or older, but to delay limb lengthening in female patients with achondroplasia until approximately 15 years of age to allow for maximal skeletal growth.

Limb lengthening in children with achondroplasia. Differences based on gender.

Twelve achondroplastic dwarfs underwent serial limb lengthening during childhood. All had repeated bilateral simultaneous elongation of their lower limbs. The height of these patients was plotted on growth curves for children with achondroplasia. The end results were evaluated after all patients reached skeletal maturity. Growth acceleration was seen in male patients with achondroplasia, but no such effect was seen in females. The female patients lost several centimeters as calculated from their predicted final height based on their preoperative growth curve and the centimeters gained by mechanical distraction. The authors' recommendation is to start limb elongation of male patients with achondroplasia at the age of 8 years or older, but to delay limb lengthening in female patients with achondroplasia until approximately 15 years of age to allow for maximal skeletal growth.

Intraoperative somatosensory evoked potential monitoring in achondroplasia

SummarySurgical airway intervention in children with achondroplastic dwarfism poses potential neurological risk secondary to the neck manipulation required for tracheal intubation and operative head positioning. This is particularly true of achondroplastic dwarfs with radiographically documented foramen magnum and spinal canal stenosis. In these children, upper extremity somatosensory evoked potential monitoring establishes the integrity of sensory conduction from peripheral nerve to cortex, providing intraoperative notification of neurologically significant cervicomedullary compression during laryngoscopy and surgical positioning.

Achondroplasia: Pre- and Postsurgical Considerations for Midface Advancement

Achondroplasia, the most common type of dwarfism, involves several physical characteristics that can cause pre- and intraoperative respiratory problems. The characteristics include rib-cage deformities, midface hypoplasia, choanal stenosis, muscular hypotonia, foramen magnum compression, and cervical abnormalities. Specific pre- and postoperative strategies for dealing with achondroplastic dwarfs are discussed.

Anesthesia for an achondroplastic dwarf presenting for urgent cesarean section

Achondroplasia is a physeal dysplasia which leads to dwarfism secondary to a decrease in the proliferation of cartilage in the growth plate. This, coupled with normal persistent bone formation, leads to the development of short tubular bones. 1 Achondroplastic dwarfism is among the more common types of dwarfism and is inherited as an autosomal dominant trait. Its incidence is reported as 1 in 26,000 live births. Most achondroplastic dwarfs have a normal life span. 2 The selection and management of anesthesia for the achondroplastic dwarf must take into account a variety of anatomic deformities. The physiologic and hormonal changes of pregnancy further complicate anesthetic administration. We report the safe use of a continuous lumbar epidural anesthetic in an achondroplastic dwarf who presented for urgent cesarean section.

Resting Metabolic Rate and Body Composition of Achondroplastic Dwarfs

Indirect calorimetry was used to measure resting metabolic rates (RMR), and densitometry and anthropometry were used to measure body fat and fat-free masses of 32 adults with very short stature. Twenty-seven of them were achondroplastic dwarfs. Their results were compared to those obtained from 103 lean and obese adults with normal heights. All 32 dwarfs had distinctly greater RMR per kg fat-free mass by densitometry than adults with average stature. However, there was a wide variation in the RMR among dwarfs, which was independent of leanness or obesity. In spite of increased RMR, obesity among dysplastic adult dwarfs was twice as prevalent as among average-height adults. Increased abdominal:hip ratios were prevalent among dwarfs, but these ratios do not reflect body fat. Body mass indices were worthless, and skinfold thicknesses and other anthropometric measurements were of very limited value in predicting the body fat of dwarfs. Although our new and specific equations for estimating RMR and body composition give reasonable values, we recommend that the caloric requirements and body compositional variables be measured if nutritional therapy is needed to induce weight loss or gain in Little People.

Surgical treatment of achondroplastic dwarfs with paraplegia

A retrospective study was done to evaluate the results of surgical intervention on the neurological symptoms associated with achondroplastic dwarfs. Between 1971 and 1979, laminectomy was performed on three patients with thoracolumbar spinal canal stenosis associated with achondroplasia. Simultaneous spondylodesis using Harrington instrumentation in conjunction with extensive laminectomy was performed in the most recent case, and excellent results were obtained. We emphasize, therefore, that neurological deficit caused by kyphotic deformity and instability secondary to extensive laminectomy for achondroplasia can be prevented by this procedure, and thus good results can be anticipated.

Surgery for Achondroplasia: Perioperative Challenges of Dwarfism

We have presented the salient points of managing achondroplastic dwarfs in the operating room. In presenting our experience in dealing with this group of patients we hope that we will make the tasks of those who care for these patients easier and help focus their attention on those problems that are more likely to occur.

Reversal of emissary vein blood flow in achondroplastic dwarfs.

We used a noninvasive technique--the directional Doppler examination--to determine the direction of flow in an emissary vein of achondroplastic dwarfs. Normally, the direction of flow in this emissary vein is into the orbit. The direction of flow in all 10 achondroplastic dwarfs whom we studied was away from the orbit. This indicates that ophthalmic vein blood flow is reversed in achondroplastic dwarfs, perhaps because there is a pressure gradient between the intracranial and extracranial venous systems.

Normal somatomedin and somatomedin receptors in achondroplastic dwarfism.

It has been proposed that the basic abnormality in achondroplasia may be a quantitative defect in endochondral new bone formation secondary to decreased synthesis of somatomedin (SM) or abnormal binding of SM to specific receptors. To test this hypothesis, we have measured plasma SM levels and SM receptors on circulating mononuclear cells obtained from 5 achondroplastic dwarfs and 5 age-matched controls. Plasma SM levels were 0.82 +/- 0.14 U/ml (mean +/- S.E.M.) for the achondroplastic dwarfs and 0.90 +/- 0.12 U/ml for the controls. The specific binding of 125I-SM to 50 x 10(6) mononuclear cells was 7.66 +/- 1.11% for the dwarf group and 7.66 +/- 1.16% for the controls. Achondroplastic and control cells possessed equal numbers of receptor sites and identical receptor affinity for SM. The data indicate that plasma SM levels and SM binding to circulating mononuclear cells are normal in achondroplastic dwarfs and suggest a primary intrace-lular defect.

Standard growth curves for achondroplasia

Standard growth curves for achondroplasia, the most common form of short-limbed dwarfism, have been constructed based on measurements of height, growth velocity, upper and lower segment, and head circumference in 400 achondroplastic dwarfs. These standard curves provide the basis to assess normal growth in these individuals, to aid in the determination of superimposed disorders, and to assess any growth accelerating therapy.