Biomedical subjects
Publications and source records attributed to Scott J Mubarak.
A thorough knowledge of the normal growth and development of the hip, the causes of abnormal development, and the structural and functional changes that result from developmental hip dysplasia and dislocation provide needed information for treating these conditions. Ultrasonography, newborn screening, and radiographic evaluation are important diagnostic tools.
Both nonsurgical and surgical options are available for the treatment of developmental hip dysplasia and dislocation. The advantages, pitfalls, and techniques for using the Pavlik harness should be thoroughly examined before treatment. Other closed and open treatments are aimed at concentric reduction and prevention of residual subluxation and dysplasia. Early diagnosis and treatment lead to the best long-term results for these conditions.
STUDY DESIGN: A case series of patients with cerebral palsy treated for spinal deformity using Luque-Galveston instrumentation was retrospectively analyzed. OBJECTIVE: To analyze the incidence and risk factors for postoperative loss of sagittal plane correction initially obtained with Luque-Galveston instrumentation in patients with cerebral palsy. SUMMARY OF BACKGROUND DATA: The Luque-Galveston instrumentation technique has been widely adopted in the treatment of neuromuscular spinal deformity. Although the results in the coronal plane have been generally satisfactory, problems in maintaining sagittal plane correction have been noted. METHODS: For this study, 41 patients with spastic quadriplegia who underwent surgical correction of spinal deformity between 1990 and 1998 were reviewed with attention given to the maintenance of sagittal plane correction. Preoperative, initial postoperative, and most recent radiographs were measured to determine the sagittal Cobb angle from T5 to T12, T12 to L2, and L1 to S1. On the basis of the preoperative sagittal alignment, patients were separated into two groups: those with preoperative hyperkyphosis (T5-T12 >or= 50 degrees, T12-L2 >or= 20 degrees, or L1-S1 >or= 0 degrees ) and those with normal or decreased kyphosis. The radiographs were assessed for proximal hardware failure/pullout or junctional kyphosis (>20 degrees ), and for backing out of the Galveston rods distally. RESULTS: Of the 41 patients, 29 underwent correction of their deformity with Luque-Galveston instrumentation alone. In 21 of these patients anterior release-fusion preceded the posterior procedure. Additional anterior lumbar instrumentation was used in 12 patients. Proximal loss of correction or implant failure occurred in 13 patients (32%). In four of these patients junctional kyphosis developed at the cephalad extent of the instrumentation, and nine patients had proximal hardware failure/pullout. Posterior migration of the distal end of the Galveston rods occurred in five patients (12%). Four of these five patients had anterior release and fusion without instrumentation. There were no distal failures in patients for whom anterior lumbar instrumentation was used. All of the patients with distal failure and 11 of 13 patients with proximal failure were considered hyperkyphotic before surgery. The region of hyperkyphosis in the patients that lost distal fixation was most often in the thoracolumbar junction. CONCLUSIONS: Preoperative hyperkyphosis in the thoracic, thoracolumbar, or lumbar spine was associated with an increased incidence of proximal and distal loss of sagittal plane correction in patients with spastic quadriplegic cerebral palsy treated with Luque-Galveston instrumentation alone. An anterior lumbar release and fusion without instrumentation in a patient with thoracolumbar or lumbar kyphosis increased the risk for posterior pullout of the Galveston rods from the pelvis.
STUDY DESIGN: A retrospective comparison of pediatric patients weighing less than 30 kg who underwent thoracoscopic anterior spinal release and fusion for deformity correction. This group was compared to two control groups: patients weighing over 30 kg (thoracoscopic) and patients under 30 kg (open). OBJECTIVE: To determine the efficacy and safety of thoracoscopic anterior spinal release and fusion in small pediatric patients weighing less than 30 kg. SUMMARY OF BACKGROUND DATA: Recently, thoracoscopic methods have been utilized to perform anterior spinal release/fusion in the treatment of pediatric and adult spinal deformity. The safety, efficacy, and technical challenges of thoracoscopic spinal surgery in small children have not been established. METHODS: "Small thoracoscopic children," defined as those under 30 kg who had thoracoscopic spinal surgery, are the main focus of this study. They were compared to "large thoracoscopic children" (>30 kg, thoracoscopic surgery) and "small open children" (<30 kg, open surgery). Preoperative, intraoperative, and postoperative parameters were analyzed. RESULTS: Small thoracoscopic children (n = 33) had greater estimated blood loss/kg body weight (13.6 mL/kg vs. 6.2 mL/kg; P= 0.003), greater chest tube output (27.5 mL/kg vs. 17.1 mL/kg; P= 0.003), and a longer intensive care unit stay (4.2 days vs. 1.5 days; P= 0.001) than did large thoracoscopic children (n = 48). Conversion to an open thoracotomy occurred in one patient from each of the thoracoscopic groups. Small thoracoscopic children required more anesthesia preparation time (79.2 minutes vs. 64.2 minutes; P= 0.002) than the small open children (n = 25). There was no significant difference in estimated blood loss, chest tube output, or intensive care unit stay between these two groups. Additionally, no significant difference was found between the three groups with regard to the number of discs excised, operative time, and total hospital stay. CONCLUSION: Despite the decreased working space within the chest and difficulties of selective intubation, anterior thoracoscopic surgery for spinal release and fusion can be performed as safely in "small" children as in "large" children; however, additional intraoperative challenges should be anticipated. Although the outcomes were similar in the small thoracoscopic children compared to the small open children, the authors believe that very small patients (under 20 kg) should remain a relative contraindication to thoracoscopic surgery, especially during a surgeon's learning curve.
BACKGROUND: Acute compartment syndrome has been widely reported in legs positioned in the lithotomy position for prolonged general surgical, urologic, and gynecologic procedures. The orthopaedic literature also contains reports of this complication in legs positioned on a fracture table in the hemilithotomy position. The purpose of this study was to identify the risk factors for development of acute compartment syndrome resulting from this type of leg positioning. METHODS: Eight healthy volunteers were positioned on a fracture table. Intramuscular pressures were continuously measured with a slit catheter in all four compartments of the left leg with the subject supine, in the hemilithotomy position with the calf supported, and in the hemilithotomy position with the heel supported but the calf free. Blood pressure was measured intermittently with use of automated pressure cuffs. RESULTS: Changing from the supine to the calf-supported position significantly increased the intramuscular pressure in the anterior compartment (from 11.6 to 19.4 mm Hg) and in the lateral compartment (from 13.0 to 25.8 mm Hg). Changing from the calf-supported to the heel-supported position significantly decreased intramuscular pressure in the anterior, lateral, and posterior compartments (to 2.8, 3.4, and 1.9 mm Hg, respectively). The mean diastolic blood pressure in the ankle averaged 63.9 mm Hg in the supine position, which significantly decreased to 34.6 mm Hg in the calf-supported position. Changing to the heel-supported position had no significant effect on the diastolic blood pressure in the ankle (mean, 32.8 mm Hg). The mean difference between intramuscular pressure and diastolic blood pressure in the supine position was approximately 50 mm Hg in each of the four compartments. This mean difference significantly decreased to <20 mm Hg in the calf-supported position and then, when the leg was moved into the heel-supported position, significantly increased to approximately 30 mm Hg in all compartments. CONCLUSIONS: The combination of increased intramuscular pressure due to external compression from the calf support and decreased perfusion pressure due to the elevated position causes a significant decrease in the difference between the diastolic blood pressure and the intramuscular pressure when the leg is placed in the hemilithotomy position in a well-leg holder on a fracture table. Combined with a prolonged surgical time, this position may cause an acute compartment syndrome of the well leg. Leaving the calf free, instead of using a standard well-leg holder, increases the difference between the diastolic blood pressure and the intramuscular pressure and may decrease the risk of acute compartment syndrome.
The incidence and predictors of premature physeal closure (PPC) after pediatric distal tibial fractures were investigated. PPC was defined as evidence of growth plate disturbance on the injured side compared with the uninjured side. Ninety-two fractures were reviewed with at least 1 year of follow-up, or until physiologic closure of the growth plates. Twenty-five fractures (27.2%) were complicated by PPC, as confirmed by CT scan in most cases. Salter-Harris III and IV (medial malleolar type) fractures resulted in the highest percentage of PPC by fracture type (38%). Salter-Harris I and II fractures resulted in PPC in 36% of cases, followed by triplane fractures (21%) and Tillaux fractures (0%). Initial displacement, number of reduction attempts, or treatment method did not significantly affect the incidence of PPC. More anatomic reductions resulted in a statistically significant decrease in PPC rates. Residual physeal gap (>3 mm) following reduction was determined from radiographs in Salter-Harris I and II fractures. If a residual gap was seen on the radiograph, the incidence of PPC increased to 60%; if no gap was present, the incidence decreased to 17%. Open reduction was performed in five Salter-Harris II fractures that had a residual gap. Periosteum was entrapped in the physis in all of these cases. Residual gaps in the physis following closed reduction may represent entrapped periosteum in Salter-Harris I and II fractures. This can lead to a higher incidence of PPC, suggesting that open reduction and removal of the entrapped periosteum may be beneficial.
This study was designed to evaluate the incidence of compartment syndrome (CS) resulting from the treatment of both-bone forearm fractures in children. A retrospective analysis of 285 consecutive children who presented with both-bone forearm fractures was performed. Of 235 closed injuries, 205 were treated with closed reduction and casting; none of these patients developed CS. Thirty of the closed injuries were treated with closed reduction and intramedullary fixation; three of these patients (10%) developed CS. Fifty patients sustained open fractures and were treated with debridement and open reduction with intramedullary pinning; CS developed in three of these patients (6%). The eighty patients treated with intramedullary fixation had an increased incidence of CS compared with the 205 patients treated with closed reduction and casting (P < 0.001). Within the group of patients who had surgery, patients with longer operative times and more use of intraoperative fluoroscopy were at higher risk of developing CS.
INTRODUCTION: The distal tibial physis is the second most commonly injured physis in long bones. Recent reports demonstrate a high rate of premature physeal closure (PPC) in Salter-Harris (SH) type I or II fractures of the distal tibia. METHODS: At our institution, 137 distal tibial SH type I or II fractures were treated from 1994 to 2002. Reviews were performed on all patients and 91 fractures met inclusion criteria. Patients were categorized according to treatment. RESULTS: We report a PPC rate of 39.6% in SH type I or II fractures of the distal tibial physis. We found a difference in PPC based on injury mechanism. The rate of PPC in patients with a supination-external-rotation-type injury was 35%, whereas patients with pronation-abduction-type injuries developed PPC in 54% of cases. Type of treatment may prevent PPC in some fractures. The most important determinant of PPC is the fracture displacement following reduction. DISCUSSION AND CONCLUSION: PPC is a common problem following SH type I or II fractures of the distal tibia. Operative treatment may decrease the frequency of PPC in some fractures. Regardless of treatment method, we recommend anatomic reduction to decrease the risk of PPC.
Nine pediatric patients (mean age 3.5 yrs) with low energy femur fractures were treated with 90/90 spica casts and developed leg compartment syndromes, Volkmann contracture, and ankle skin loss. These cases are detailed and a proposed mechanism leading to this devastating complication is explained. The authors believe the technique of an initial below knee cast, and then using that cast for applying traction while immobilizing the child in the 90/90 spica is potentially dangerous. Alternative spica application methods are advocated.
Focal fibrocartilaginous dysplasia (FFCD) is a benign condition first described in 1985 as a cause of tibia vara. We are reporting on 11 cases. The lesions involved proximal tibia (9 cases), distal femur (1 case), and distal ulna (1 case). We believe that this entity represents a bony anchor preventing natural sliding of the periosteum during growth (an "epiphysiodesis-like" effect). For the tibia, we believe this is the pes anserinus. We are suggesting that this entity be called a "fibrous periostal inclusion." Treatment indications result from this concept: (1) for tibial lesions with a metaphyseal-diaphyseal angle less than 20 degrees observation for 6 to 12 months; (2) if the deformity improves, the tether likely broke spontaneously, and no treatment is required; and (3) curettage early if the deformity worsens. This will be followed by rapid correction into physiological valgus (tibia) and prevent the need for osteotomy. Early curettage for other less common locations is recommended.
The purpose of this study was to evaluate the results of a modification of the posterior tibial tendon transfer in Duchenne muscular dystrophy patients with regard to foot deformity and ambulation. The records of 57 patients with Duchenne muscular dystrophy were retrospectively reviewed. Three treatment groups were studied: group 1, those who had surgery to maintain ambulation; group 2, those who had surgery to correct and maintain foot position; and group 3, those who had no surgery. All surgical patients had posterior tibial tendon transfer and Achilles tendon lengthening as part of their procedure. Thirty-four patients returned for interviews and examinations to assess outcomes and foot position. The mean age at cessation of ambulation for those who had surgery was 11.2 years versus 10.3 years for those who did not have surgery. Of 48 feet in 24 patients who underwent lower extremity surgery to correct and maintain foot position, 94% were clinically satisfactory at a mean of 8.5 years after surgery. Regardless of the desire to continue ambulation, all patients should have posterior tibial tendon transfer, Achilles tendon lengthening, and toe flexor tenotomies to maintain plantigrade feet.
Fractures of the anterior superior iliac spine (ASIS) in adolescents are usually due to avulsion of the sartorius origin from the ASIS; however, the authors here report a second type due to avulsion of the tensor fascia lata origin. Eight patients were identified with ASIS avulsion fractures. Type II sartorius avulsion fracture was due to sprinting in various sports (n = 6). The fragment was smaller and displaced anteriorly. Type II tensor fascia lata avulsion fractures were due to swinging a baseball bat. The two muscular males were both injured during the initial phase of batting. The bony fragment was much larger and displaced laterally as confirmed by three-dimensional computed tomography scans.
Because of the high rate of avascular necrosis, Pavlik developed his harness and method of treating developmental dysplasia of the hip in infants. This historical review highlights Pavlik's career from the time he worked with Frejka and then later in his own clinic in Olomouc, Czech Republic (1938). In the 1950s, he wrote five articles on the results of his harness use in developmental dysplasia of the hip. Subsequently, Pavlik's harness has become the orthosis of choice worldwide for treatment of infants with hip dysplasia because of the principles he espoused.