Kathryn A. Keeler

Operative treatment of adolescent idiopathic scoliosis with posterior pedicle screw-only constructs: minimum three-year follow-up of one hundred fourteen cases.

Study Design. Preoperative review of a prospective study, single institution, consecutive series. Objective. To analyze the intermediate-term follow-up of consecutive adolescent idiopathic scoliosis (AIS) patients treated with pedicle screw constructs. Summary of Background Data. There have been no reports of the intermediate-term findings in North America following posterior spinal fusion with the use of pedicle screw-only constructs. Methods. One hundred and fourteen consecutive patients having a minimum 3-year follow-up (mean 4.8 ± 1.1; range, 3.0–7.3 years) with AIS were evaluated. The average age at surgery was 14.9 ± 2.2 years. Radiographic measurements included preoperative (Preop), postoperative (PO), 2-year (2 years), and final follow-up (FFU). A chart review evaluated PFTs, Scoliosis Research Society scores, presence of thoracoplasty, Risser sign, Lenke classification, and complications. Results. The most frequent curve pattern was Lenke type 1 (45.6%), followed by type 3 (21.9%). The average main thoracic curve measured 59.2° ± 12.2 SD Preop, and corrected to 16.8° ± 9.9 PO (P < 0.0001). Sagittal thoracic alignment (T5–T12) decreased from 25.8° to 15.5° at FFU (P = 0.05). Nash-Moe grading for apical vertebral rotation (AVR) in the proximal thoracic curve decreased from 2.0 Preop to 1.1 at FFU (P < 0.0001), and AVR in the thoracolumbar/lumbar spine decreased from 1.6 Preop to 1.1 at FFU (P < 0.0001). Importantly, the horizontalization of the subjacent disc measured −8.3° Preop which decreased to −0.9° PO (P < 0.001). PFT follow-up averaged 2.4 years with a 7.1% improvement in FVC (P = 0.004) and 8.8% in FEV1 (P < 0.0001). SRS scores averaged 83.0% at latest follow-up. Age, gender, Risser sign, or complications did not have a significant effect on outcomes. There were 2 cases of adding-on, 3 late onset infections, 1 with a single pseudarthrosis, but no neurologic complications. Conclusion. This is the largest (N = 114), consecutive series of North American patients with AIS treated with pedicle screws having a minimum of 3-year follow-up. The average curve correction was 68% for the main thoracic, 50% for the proximal thoracic, and 66% for the thoracolumbar/lumbar curve at final follow-up.

Computed Tomography Evaluation of Pedicle Screws Placed in the Pediatric Deformed Spine Over an 8-year Period

Study Design. A retrospective review. Objective. To evaluate the incremental accuracy of pedicle screws used in spinal deformity via a free-hand technique at a single institution over an 8-year period. Summary of Background Data. The in vivo accuracy of free-hand pedicle screws placed throughout the deformed spine as evaluated by computed tomography (CT) scanning is unknown over a long time period. Methods. A total of 1023 pedicle screws inserted from T1 to L4 in 60 patients (928 screws in 54 scoliosis patients and 95 screws in 6 kyphosis patients) over an 8-year period were investigated via postoperative CT scans. Patients were divided into 3 groups (group I = 1998–1999, group II = 2001–2002, and group III = 2005). All pedicle screws were inserted via the free-hand technique using anatomic landmarks, specific entry sites, neurophysiologic, and radiographic confirmation. Pedicle screw position on CT scan was graded as acceptable versus violated, defined as the screw axis being outside the pedicle wall. Results. One hundred seven of 1023 pedicle screws (10.5%) demonstrated significant mediolateral pedicle wall violations (19 medial vs. 88 lateral, P = 0.001). groups I and III had significantly higher lateral wall violations than group II (P < 0.05) as did the kyphotic spines (vs. scoliotic spine, P < 0.05). There were significantly more screws placed in the periapical region over time (P < 0.0001), with left-sided lateral violations (T5–T8) increasing from group II to group III, while the number of medial violations significantly decreased with time (P < 0.0001). Pedicle screws placed on the right side showed a significant decrease in accuracy from group II to group III (P = 0.03). The average transverse angle of the acceptable screws was 15.3° which was significantly different from the medial (23.0°, P < 0.001) and lateral (10.6°, P < 0.001) violations between group I and group II. No screws demonstrated neurologic, vascular, or visceral complications. Conclusion. Overall accuracy of acceptable screws using the free-hand pedicle screw placement technique in the deformed spine was 89.5%, without any neurologic, vascular, or visceral complications over an 8-year period. The rate of medial violations decreased with time, as the number of screws placed in the periapical region increased.

Antegrade Intramedullary Nailing of Pediatric Femoral Fractures Using an Interlocking Pediatric Femoral Nail and a Lateral Trochanteric Entry Point

Background: The treatment of femoral shaft fractures in older children and adolescents using rigid intramedullary (IM) nail fixation offers the advantages of decreased soft tissue stripping, low incidence of malalignment, leg length discrepancy, early ambulation, and decreased hospital stay. Recent reports have described the development of osteonecrosis of the femoral head in children after IM nailing through the piriformis fossa and the tip of the greater trochanter. Others have noted secondary proximal femoral valgus and femoral neck narrowing after antegrade IM nailing. Using the lateral aspect of the greater \trochanter as the starting point avoids the tenuous blood supply of the proximal femur and did not seem to produce avascular necrosis or proximal femoral deformity in early reports. Methods: A retrospective clinical and radiographic review of 78 children and adolescents with 80 femoral shaft fractures who underwent IM nail fixation through the lateral aspect of the greater trochanter, with a mean follow-up of 99 weeks, was performed. Twenty-four fractures were observed until skeletal maturity. Final standing anteroposterior radiographs of both lower extremities were used to assess for evidence of osteonecrosis, limb length discrepancy, fracture alignment, and indices around the hips. Results: All patients went on to union in good clinical alignment without loss of reduction. No nonunions, delayed unions, or malunions were observed. Two patients developed infections postoperatively (2.5%). No patient had evidence of osteonecrosis of the femoral head. There was no significant difference in neck-shaft angle, articulotrochanteric distance, or femoral diameter when compared with the nonsurgical, normal side in these patients. Conclusions: Intramedullary nail fixation through the lateral aspect of the greater trochanter in children and adolescents is effective. It does not produce clinically important femoral neck valgus or narrowing. We did not observe osteonecrosis of the femoral head. Level of Evidence: Level IV, case series.

Can Posterior-Only Surgery Provide Similar Radiographic and Clinical Results as Combined Anterior (Thoracotomy/Thoracoabdominal)/Posterior Approaches for Adult Scoliosis?

Study Design. Retrospective matched cohort analysis. Objective. To determine if posterior-only (post-only) surgical techniques consisting of pedicle screws, osteotomies, transforaminal lumbar interbody fusion, and bone morphogenetic protein-2 may provide similar results as compared anterior (thoracotomy/thoracoabdominal)/posterior surgical approaches for the treatment of adult spinal deformity with respect to correction, fusion rates, or outcomes. Summary of Background Data. Combined anterior/posterior (A/P) fusion has traditionally been used to treat many adult scoliosis deformities. Anterior approaches negatively impact pulmonary function and require additional operative time and anesthesia. Methods. Twenty-four patients who had A/P fusion for primary adult scoliosis (16 staged, 8 same-day) were matched with a cohort of 24 patients who had post-only treatment. Anterior fusion was performed via a thoracotomy (n = 1)/thoracoabdominal (n = 23) approach. All post-only surgeries were under one anesthesia. Minimum 2-year follow-up included radiographic, clinical, and outcomes data. Results. There were no significant differences between groups for age, gender, diagnosis, comorbidities, preoperative curve magnitudes, or global balance. Postoperative radiographic correction and alignment were similar for both groups except for thoracolumbar curve percent improvement which was statistically better in the post-only group (P = 0.03). The average surgical time was higher in A/P versus post-only group (11.6 vs. 6.9 hours, P < 0.0001) as was total estimated blood loss (1330 vs. 980 mL, P = 0.04). Hospital length of stay (LOS) was longer in A/P versus post-only group (11.9 vs. 8.3 days, P = 0.03). There were no significant differences between postoperative complications. Revision surgery was performed in 5 A/P and 2 post-only patients. Higher pseudarthrosis rates found in the A/P versus post-only (17 vs. 0%) were not significant (P = 0.11). SRS-30 and Oswestry scores reflected a similar patient assessment before surgery, and improvement between groups at follow-up. Conclusion. Post-only adult scoliosis surgery achieved similar correction to A/P surgery while decreasing blood loss, operative time, length of stay, and avoiding additional anesthesia. Complications, radiographic, and clinical outcomes were similar at over 2-year follow-up.

Spinal fusion for spastic neuromuscular scoliosis: is anterior releasing necessary when intraoperative halo-femoral traction is used?

Study Design. Retrospective radiographic and clinical study. Objective. To compare the complications and radiographic outcomes of 2 types of surgical treatments, posterior-only fusion and circumferential fusion, in patients with nonambulatory quadriplegic cerebral palsy treated with adjunctive intraoperative halo-femoral traction. Summary of Background Data. Circumferential anterior-posterior spinal fusion (A/PSF) has been used to improve deformity correction and rate of fusion in patients with neuromuscular scoliosis (NMS) but is associated with increased morbidity. Anterior procedures may increase operative time (OR time) and estimated blood loss (EBL) as well as compromise pulmonary function. Posterior-only spinal fusion (PSF-only) may be sufficient, thereby forgoing the need for the anterior approach without sacrificing deformity correction or outcome. Methods. Twenty-six patients (age <21 years) who underwent PSF-only for spastic NMS (quadriplegic cerebral palsy) were matched with a comparison cohort of 26 patients who underwent A/PSF (11 staged, 15 same day). All posterior fusions extended from the proximal thoracic spine (T2/T3) to the pelvis. Anterior fusions used a thoracoabdominal approach. All 52 patients underwent intraoperative halo-femoral traction. Mean follow-up for PSF-only was 2.9 years and A/PSF 3.3 years. Results. There were no significant differences between the 2 groups in demographic data or preoperative radiographic measures. The PSF-only group had statistically significant shorter OR time (6.1 vs. 10.3 hours), lower EBL (873 vs. 1361 mL), lower frequency of postoperative intubation (38% vs. 81%), shorter length of postoperative intubation (2 vs. 6.5 days), and lower frequency of postoperative pulmonary complications (7.7% vs. 26.9%). There were no statistically significant differences at the final follow-up for thoracolumbar/lumbar curve Cobb, % correction of thoracolumbar/lumbar Cobb, pelvic obliquity, C7 plumb line and the center sacral vertical line, sagittal T5–T12, sagittal T10–L2, and sagittal T12–S1 Cobb measurements. There were no halo-femoral traction-related complications. Conclusions. When intraoperative halo-femoral traction is used, PSF-only surgery for NMS can provide excellent curve correction and spinal balance. In this study, the PSF-only group had shorter OR time, lower EBL, lower frequency of postoperative intubation, and fewer cases of pneumonias when compared with A/PSF with similar radiographic outcomes at 2-year follow-up.

Complications of blade plate removal.

The AO fixed-angle blade plate is commonly used to obtain fixation in proximal femoral osteotomies. This device provides stable fixation and obviates the need for postoperative immobilization. There are no reports in the literature on the rate and types of complications associated with blade-plate removal. We report our rate and type of perioperative and early postoperative complications associated with removal of fixed-angle blade plates in a pediatric population. With an overall complication rate of 5.3% and a major complication rate of 2.0%, our study showed that removal of the blade plate was a relatively safe procedure in those patients troubled by prominent/painful hardware or skin breakdown.

Treatment of Femur Fractures in Young Children: A Multicenter Comparison of Flexible Intramedullary Nails to Spica Casting in Young Children Aged 2 to 6 Years

Background: Spica casting is the standard of care for femur fractures in children up to 6 years of age. The indications for surgery are controversial. We sought to compare immediate spica casting (Spica) and flexible intramedullary nailing [titanium elastic nailing (TEN)] in a group of children ages 2 to 6 years. We hypothesized that young children can be successfully treated with flexible nails, resulting in faster return to ambulation and an equivalent complication rate when compared with spica casting. Methods: This was a multicenter retrospective review of 215 patients, 141 treated with immediate spica casting, and 74 treated with elastic nails. Patient demographics, fracture characteristics, mechanism of injury, associated injuries, outcomes, and complications were recorded and compared between the 2 groups. Results: Patients in the elastic nailing group were more likely to be injured as a pedestrian struck by an automobile (Spica 8% vs. TEN 26%, P=0.001), and had increased rates of associated injuries (P<0.001). Time to fracture union was similar between the 2 groups (P=0.652). The TEN group had shorter time to independent ambulation (Spica 51±14 vs. TEN 29±14 d, P<0.001) and return to full activities (Spica 87±19 vs. TEN 74±28 d, P=0.023). Conclusions: TEN is a reasonable option for treatment of femur fractures in young children when compared with spica casting with shorter time to independent ambulation and full activities. Fractures associated with a high-energy mechanism are especially appropriate for consideration of treatment with TEN. Level of Evidence: Level III, this was a retrospective comparative study.

Acute compartment syndrome after intramedullary nailing of isolated radius and ulna fractures in children.

Background: There exist varying reports in the literature regarding the incidence of compartment syndrome (CS) after intramedullary (IM) fixation of pediatric forearm fractures. A retrospective review of the experience with this treatment modality at our institution was performed to elucidate the rate of postoperative CS and identify risk factors for developing this complication. Methods: In this retrospective case series, we reviewed the charts of all patients treated operatively for isolated radius and ulnar shaft fractures from 2000 to 2009 at our institution and identified 113 patients who underwent IM fixation of both-bone forearm fractures. There were 74 closed fractures and 39 open fractures including 31 grade I fractures, 7 grade II fractures, and 1 grade IIIA fracture. If the IM nail could not be passed easily across the fracture site, a small open approach was used to aid reduction. Results: CS occurred in 3 of 113 patients (2.7%). CS occurred in 3 of 39 (7.7%) of the open fractures compared with none of 74 closed fractures (P=0.039), including 45 closed fractures that were treated within 24 hours of injury. An open reduction was performed in all of the open fractures and 38 (51.4%) of the closed fractures. Increased operative time was associated with developing CS postoperatively (168 vs. 77 min, P<0.001). CS occurred within the first 24 postoperative hours in all 3 cases. Conclusion: CS was an uncommon complication after IM fixation of pediatric diaphyseal forearm fractures in this retrospective case series. Open fractures and longer operative times were associated with developing CS after surgery. None of 45 patients who underwent IM nailing of closed fractures within 24 hours of injury developed CS; however, 51.4% of these patients required a small open approach to aid reduction and nail passage. We believe that utilizing a small open approach for reduction of one or both bones, thereby avoiding the soft-tissue trauma of multiple attempts to reduce the fracture and pass the nail, leads to decreased soft-tissue trauma and a lower rate of CS. We recommend a low threshold for converting to open reduction in cases where closed reduction is difficult.

Femoral lengthening over a pediatric femoral nail: results and complications.

Background: Limb lengthening by callotasis as described by Ilizarov has become the standard method of lower extremity lengthening. Lengthening over an intramedullary nail to allow early removal of the external fixator has also become common in adults but few studies have addressed the efficacy in children. Methods: A retrospective review of 37 consecutive children who had undergone femoral lengthening with external fixator over an intramedullary nail was performed. Charts were reviewed for demographics, surgical details, and complications. Radiographs were examined to determine magnitude of lengthening and to calculate lengthening index. Results: The average age of the 37 patients was 11.6 years (range, 8.1 to 17.0). The amount of lengthening averaged 7.0 cm (range, 3.0 to 11.4 cm), which represented a mean 20.4% increase in length. The mean time in the fixator was 81 days. The lengthening index was 1.21 days/mm. Thirteen patients developed major complications (37.8%) including 4 limbs that failed to lengthen initially, 3 fractures (1 before fixator removal and 3 after fixator removal), 2 nail failures, 4 deep infections, and 2 joint subluxations requiring operative care. The 3 fractures after fixator removal were treated with exchange nailing as were the 2 intramedullary nail failures. Four patients (10.8%) developed deep infections requiring irrigation, debridement, and IV antibiotics. One patient developed a late hip subluxation, which was treated with a shelf osteotomy but resulted in pain and limitation of motion. One patient developed knee subluxation during lengthening requiring operative intervention. The technique was successful in obtaining a good result with a functional lengthened femur without unresolved problems in 94% of the patients despite a significant rate of major complications, particularly in those with a congenital etiology. Only 2 of the 37 patients ultimately had results that were ultimately compromised by complications. Conclusions: Femoral lengthening over an intramedullary nail with the aid of an external fixator has shown to be an effective method for correcting limb length discrepancy. The technique has a high complication rate similar to other methods of lengthening. Level of Evidence: Level IV—Case Series.

Comparison of magnetic resonance imaging and computed tomography in predicting facet arthrosis in the cervical spine.

Study Design. Retrospective review. Objective. To determine the ability of magnetic resonance imaging (MRI) and computed tomography (CT) to predict the presence of cervical facet arthrosis. Summary of Background Data. In the Food and Drug Administration Investigational Device Exemption trials of cervical disc arthroplasty (CDA), the presence of facet arthrosis on CT was a contraindication to the insertion of a CDA. Most surgeons routinely obtain an MRI, but not necessarily a CT before performing surgery in the cervical spine. We sought to determine if the MRI alone is adequate to assess for the presence of facet arthrosis. Methods. Three experienced spine surgeons retrospectively evaluated CT scans and MRIs of the same patients, obtained within 30 days of each other in a blinded, random fashion. Reviewers graded each of the MRI and CT scan as normal or abnormal on 3 separate occasions and if the facet was abnormal, each reviewer graded the degree of arthrosis. The radiologist’s evaluation for each study was compared with our results. Results. Of 594 facets analyzed, 43.1% were categorized as normal on CT, and of those, MRI concordance was only 63.7% with moderate/substantial intermethod agreement. Furthermore, MRI was concordant only 15.9% of the time in patients with ankylosed facet joints on CT. CT inter-rater reliability showed substantial agreement for diagnoses of both normal and ankylosis and fair agreement for lesser degrees of facet arthrosis. MRI inter-rater reliability showed fair/moderate agreement in normal and ankylosed segments and only slight agreement with lesser degrees of facet arthrosis. CT intrarater reliability showed substantial agreement in normal or ankylosed joints, but only fair agreement for all other categories; MRI showed only fair agreement. Conclusion. The ability of MRI to adequately determine the presence or amount of facet arthrosis is not reliable. Additionally, for abnormal facets, MRI was not reliable in adequately determining the degree of arthrosis. Our data suggest that computed tomography remains necessary in diagnosing facet arthrosis before CDA.