Fully automated determination of robotic pedicle screw accuracy and precision utilizing computer vision algorithms.

Historically, pedicle screw accuracy measurements have relied on CT and expert visual assessment of the position of pedicle screws relative to preoperative plans. Proper pedicle screw placement is necessary to avoid complications, cost and morbidity of revision procedures. The aim of this study was to determine accuracy and precision of pedicle screw insertion via a novel computer vision algorithm using preoperative and postoperative computed tomography (CT) scans. Three cadaveric specimens were utilized. Screw placement planning on preoperative CT was performed according to standard clinical practice. Two experienced surgeons performed bilateral T2-L4 instrumentation using robotic-assisted navigation. Postoperative CT scans of the instrumented levels were obtained. Automated segmentation and computer vision techniques were employed to align each preoperative vertebra with its postoperative counterpart and then compare screw positions along all three axes. Registration accuracy was assessed by preoperatively embedding spherical markers (tantalum beads) to measure discrepancies in landmark alignment. Eighty-eight pedicle screws were placed in 3 cadavers' spines. Automated registrations between pre- and postoperative CT achieved sub-voxel accuracy. For the screw tip and tail, the mean three-dimensional errors were 1.67 mm and 1.78 mm, respectively. Mean angular deviation of screw axes from plan was 1.58°. For screw mid-pedicular accuracy, mean absolute error in the medial-lateral and superior-inferior directions were 0.75 mm and 0.60 mm, respectively. This study introduces automated algorithms for determining accuracy and precision of planned pedicle screws. Our accuracy outcomes are comparable or superior to recent robotic-assisted in vivo and cadaver studies. This computerized workflow establishes a standardized protocol for assessing pedicle screw placement accuracy and precision and provides detailed 3D translational and angular accuracy and precision for baseline comparison.

What is the Utilization and Impact of Advanced Imaging for Tibial Tubercle Fractures? An Analysis of 598 Patients From the Tibial Tubercle Study (TITUS) Group.

BACKGROUND: Given the rare nature of tibial tubercle fractures, previous studies are mostly limited to small, single-center series. This results in practice variation. Previous research has shown poor surgeon agreement on utilization of advanced imaging, but improved evidence-based indications may help balance clinical utility with resource utilization. The purpose of this study is to quantify diagnostic practices for tibial tubercle fractures in a large, multicenter cohort, with attention to the usage and impact of advanced imaging. METHODS: This is a retrospective series of pediatric tibial tubercle fractures from 7 centers between 2007 and 2022. Exclusion criteria were age above 18 years, missing demographic and pretreatment data, closed proximal tibial physis and tubercle apophysis, or a proximal tibia fracture not involving the tubercle. Demographic and injury data were collected. Fracture classifications were derived from radiographic evaluation. The utilization of advanced imaging was recorded as well as the presence of findings not identified on radiographs. Standard descriptive statistics were reported, and χ2 tests were performed (means reported±SD). RESULTS: A total of 598 patients satisfied the inclusion criteria, of which 88.6% (530/598) were male with a mean age of 13.8±1.9 years. Internal oblique x-rays were obtained in 267 patients (44.6%), computed tomography (CT) in 158 (26.4%), and magnetic resonance imaging (MRI) in 64 (10.7%). There were significant differences in the frequency at which CT (7.2% to 79.4%, P<0.001) and MRI were obtained (1.5% to 54.8%, P<0.001). CT was obtained most frequently for Ogden type IV fractures (50/99, 50.5%), and resulted in novel findings that were not visualized on radiographs in a total of 37/158 patients (23.4%). The most common finding on CT was intra-articular fracture extension (25/37). MRI was obtained most frequently for Ogden type V fractures (13/35, 37.1%), and resulted in novel findings in a total of 31/64 patients (48.4%). The most common finding was patellar tendon injury (11/64), but only 3 of these patients required tendon repair. CONCLUSIONS: Substantial variation exists in the diagnostic evaluation of tibial tubercle fractures. CT was most helpful in clarifying intra-articular involvement, while MRI can identify patellar tendon injury, periosteal sleeve avulsion, or a nondisplaced fracture. This study quantifies variation in diagnostic practices for tibial tubercle fractures, highlighting the need for evidence-based indications for advanced imaging. LEVEL OF EVIDENCE: Level III.

The Longitudinal Effects of Posterior Spinal Fusion with Derotation on Axial Deformity in Adolescent Idiopathic Scoliosis.

STUDY DESIGN: Retrospective case series. OBJECTIVE: To characterize the change in angle of trunk rotation (ATR), axial vertebral rotation (AVR), and body surface rotation (BSR) in patients with adolescent idiopathic scoliosis (AIS) undergoing posterior spinal fusion (PSF) with en-bloc derotation across multiple postoperative visits. SUMMARY OF BACKGROUND DATA: Previous research has documented ATR, AVR, and BSR correction for AIS patients after surgery. However, there is a lack of evidence on the sustainability of this correction over time. METHODS: This was a retrospective study from a single-center prospective surface topographic registry of patients with AIS, age 11-20 at time of surgery, who underwent PSF with en-bloc derotation. Patients with previous spine surgery were excluded. ATR was measured with a scoliometer, AVR through EOS radiographic imaging, and BSR via surface topographic scanning, Data collection occurred at: preoperative, six-week, three-month, six-month, one-year, and two-year postoperative visits. BSR and AVR were tracked at the preoperative apical vertebral level, and the level with maximum deformity, at each respective timepoint. Generalized estimating equations models were used for statistical analysis. Covariates included age, sex, and body mass index. RESULTS: 49 patients (73.4% female, mean age 14.6±2.2 years, mean preoperative coronal curve angle 57.9°±8.5, and 67% major thoracic) were evaluated. ATR correction was significantly improved at all postoperative timepoints and there was no significant loss of correction. AVR Max and AVR Apex were significantly improved at all timepoints but there was a significant loss of correction for AVR Apex between the six-week and one-year visit (P=0.032). BSR Max achieved significant improvement at the three-month visit. BSR Apex was significantly improved at the three-month and one-year visit. CONCLUSION: ATR and AVR demonstrated significant axial plane correction at two-years postoperative in patients undergoing PSF for AIS. BSR did not maintain significant improvement by the two-year visit.

Novel Surface Topographic Assessment of Lung Volume and Pulmonary Function Tests in Idiopathic Scoliosis: A Preliminary Study.

OBJECTIVE: Severe spinal deformity results in restrictive pulmonary disease from thoracic distortions and lung-volume limitations. Though spirometry and body plethysmography are widely accepted tests for pulmonary function tests (PFTs), they are time-consuming and require patient compliance. This study investigates whether surface topographic [surface topography (ST)] measurements of body volume difference (BVD) and torso volume difference between maximum inhale and exhale correlate to values determined on PFTs. METHODS: This study included patients with idiopathic scoliosis and thoracic/thoracolumbar curves ≥40 degrees. Patients received ST scans, clinical examinations, and EOS biplanar radiographs on the same day. PFTs were performed within 3 months of ST/radiographic analysis. Univariate linear regression analysis was used to examine relationships between BVD, PFT values, and mean curves. RESULTS: Sixteen patients (14.6 ± 2.2 y, 69% females) with idiopathic scoliosis and mean thoracic/thoracolumbar curves of 62 degrees ± 15˚ degrees (45 degrees to 93 degrees) were assessed. BVD displayed statistically high-positive positive correlations with forced vital capacity ( R = 0.863, P < 0.0001), forced expiratory volume in 1 second ( R = 0.870, P < 0.001), vital capacity ( R = 0.802, P < 0.0001), and TLC ( R = 0.831, P < 0.0001. Torso volume difference showed similarly high positive correlations to forced vital capacity, forced expiratory volume in 1 second, vital capacity, and TLC, but not residual volume. No correlations emerged between the mean thoracic/thoracolumbar curve and BVD or PFT values. CONCLUSION: This study strongly endorses further investigation into ST scanning as an alternative to traditional PFTs for assessing pulmonary volumes. The noncontact and noninvasive nature of ST scanning presents a valuable alternative method for analyzing thoracic volume, particularly beneficial for patients unable to cooperate with standard PFTs. LEVEL OF EVIDENCE: Level II-prognostic.

Hemiepiphysiodesis for Genu Valgum in Patients With Multiple Hereditary Exostoses.

BACKGROUND: Genu valgum is a well-known feature of multiple hereditary exostoses (MHE). Though prior reports have demonstrated successful treatment with hemiepiphysiodesis, details regarding the correction rate and comparison to an idiopathic population are lacking. This study aimed to detail our institution's experience with guided growth of the knee in patients with MHE and compare this to an idiopathic population. METHODS: All pediatric patients (age 18 and younger) with MHE who underwent lower extremity hemiepiphysiodesis at a tertiary care medical center between January 2016 and December 2022 were retrospectively reviewed. Preoperative and postoperative mechanical lateral distal femoral angle (mLDFA) and medial proximal tibial angle (MPTA, the primary outcomes) were measured in addition to mechanical axis deviation (MAD) and hip-knee-ankle angle (HKA). Patients were 1:2 matched based on age, sex, and physes instrumented to a cohort with idiopathic genu valgum. RESULTS: A total of 21 extremities in 16 patients with MHE underwent hemiepiphysiodesis of the distal femur, proximal tibia, and/or distal tibia. The mean age at surgery was 11.7±2.2 years. Mean MAD corrected from zone 1.9±0.7 to -0.3±1.5, while mLDFA corrected from 83.4±2.9 to 91.7±5.2 degrees and MPTA corrected from 95.3±3.6 to 90.5±4.0 degrees in distal femurs and proximal tibias undergoing guided growth, respectively. Three extremities (14.3%) experienced overcorrection ≥5 degrees managed with observation. There were no differences in correction rates per month for mLDFA (0.54±0.34 vs. 0.51±0.29 degrees, P =0.738) or MPTA (0.31±0.26 vs. 0.50±0.59 degrees, P =0.453) between MHE and idiopathic groups. For 11 extremities in the MHE group with open physes at hardware removal, they experienced a mean recurrence of HKA of 4.0±3.4 degrees at 19-month follow-up. CONCLUSION: Hemiepiphysiodesis corrects lower extremity malalignment in patients with MHE at a similar rate compared with an idiopathic coronal plane deformity population. Rebound deformity of 4 degrees at 19 months after hardware removal in patients with remaining open growth plates should make surgeons conscious of the remaining growth potential when planning deformity correction. LEVEL OF EVIDENCE: Level III.

Incidence of Nerve Palsies During Pavlik Harness Treatment for Developmental Dysplasia of the Hip: A Retrospective Cohort Study.

BACKGROUND: The Pavlik harness has been used for approximately a century to treat developmental dysplasia of the hip (DDH). Femoral nerve palsy is a documented complication of Pavlik harness use, with an incidence ranging from 2.5% to 11.2%. Rare reports of brachial plexus palsy have also been documented. The primary purpose of the current study was to evaluate the incidence of various nerve palsies in patients undergoing Pavlik harness treatment for DDH. Secondary aims were to identify patient demographic or hip characteristics associated with nerve palsy. METHODS: We performed a retrospective review of patients diagnosed with DDH and treated with a Pavlik harness from February 1, 2016, to April 1, 2023, at a single tertiary care orthopaedic hospital. Hip laterality, use of a subsequent rigid abduction orthosis, birth order, breech positioning, weight, and family history were collected. The median (and interquartile range [IQR]) or mean (and standard deviation [SD]) were reported for all continuous variables. Independent 2-sample t tests and Mann-Whitney U tests were conducted to identify associations between the variables collected at the initiation of Pavlik harness treatment and the occurrence of nerve palsy. RESULTS: Three hundred and fifty-one patients (547 hips) were included. Twenty-two cases of femoral nerve palsy (4% of all treated hips), 1 case of inferior gluteal nerve palsy (0.18%), and 2 cases of brachial plexus palsy (0.37%) were diagnosed. Patients with nerve palsy had more severe DDH as measured by the Graf classification (p < 0.001) and more severe DDH as measured on physical examination via the Barlow and Ortolani maneuvers (p = 0.003). CONCLUSIONS: Nerve palsies were associated with more severe DDH at the initiation of Pavlik harness use. Upper and lower-extremity neurological status should be scrutinized at initiation and throughout treatment to assess for nerve palsies. The potential for femoral, gluteal, and brachial plexus palsies should be included in the discussion of risks at the beginning of treatment. Families may be reassured that nerve palsies associated with Pavlik harness can be expected to resolve with a short break from treatment. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

The global impact of the COVID-19 pandemic on pediatric spinal care: A multi-centric study.

Background: The COVID-19 pandemic has affected healthcare worldwide since December 2019. We aimed to identify the effect of the COVID-19 pandemic on outpatient clinic and surgical volumes and peri-operative complications for pediatric spinal deformities patients. Methods: In this multi-center retrospective study, outpatient visits (in-person and virtual care) and pediatric spine surgeries volumes in four high-volume pediatric spine centers were compared between March and December 2019 and the same period in 2020. Peri-operative complications were collected and compared in the same periods. Descriptive statistics were calculated, and comparative analyses were performed. Results: During the 2020 study period, the outpatient visit (in-person and virtual care) volume decreased during local lockdown periods by 71% for new patients (p < 0.001) and 53% for returning patients (p = 0.03). Overall, for 2020, there was a 20% reduction in new patients (p = 0.001) and 21% decrease in returning patients (p < 0.001). During the pandemic, there was also 20% less overall surgical volume of adolescent idiopathic scoliosis (AIS) patients undergoing primary posterior spinal fusion, with a 70% reduction during lockdown times (p < 0.001). Complication rate and profile were similar between periods. Conclusion: There was a significant decrease in outpatient pediatric spine outpatient visits, particularly new patients, which may increase the proportion of pediatric patients with spinal deformities that present late, meeting surgical indication. This, in combination with the reduction in surgical volume of AIS over the first year of the pandemic, could result in an extended waitlist for surgeries during years to come. Complication rate was similar for both periods, suggesting it is safe to continue elective pediatric spine surgery even in a time of a pandemic. Level of evidence: level IV.

Flatfoot Reconstruction for Painful Pediatric Idiopathic Flexible Flatfoot: Prospective Study Demonstrates Improved Alignment, Function, and Patient-reported Outcomes.

BACKGROUND: This prospective study was undertaken to report outcomes following reconstructive surgery for patients with painful pediatric idiopathic flexible flatfoot. METHODS: Twenty-five patients with pediatric idiopathic flexible flatfoot were evaluated pre- and post flatfoot reconstruction with lateral column lengthening (LCL). All patients had lengthening of the Achilles or gastrocnemius, while 13 patients had medial side soft tissue (MSST) procedures, 7 underwent medial cuneiform plantarflexion osteotomy (MCPO), and 5 had medializing calcaneal osteotomy. Measures of static foot alignment-both radiographic parameters and clinical arch height indices-were compared, as were measures of dynamic foot alignment and loading, including arch height flexibility and pedobarography. Preoperative and postoperative patient-reported outcome (PRO) scores were compared between those treated with or without MSST procedures. RESULTS: The median subject age was 13.8 years (range: 10.3 to 16.5) at the time of surgery. All radiographic parameters improved with surgery ( P <0.001). The mean sitting arch height index showed a modest increase after surgery ( P =0.023). Arch height flexibility was similar after surgery. The mean center-of-pressure excursion index increased from 14.1% to 24.0% ( P <0.001), and the mean first metatarsal head (MH) peak pressure dropped ( P <0.001), while the mean fifth MH peak pressure increased ( P =0.018). The ratio of peak pressure in the fifth MH to peak pressure in the second MH increased ( P =0.010). The ratio of peak pressure in the first MH to peak pressure in the second MH decreased when an MCPO was not used ( P <0.002), but it remained stable when an MCPO was included. Mean scores in all PRO domains improved ( P <0.001). Patients treated without MSST procedures showed no difference in PROMIS Pain Interference scores compared to those without MSST procedures. CONCLUSIONS: Flatfoot reconstruction surgery using an LCL with plantarflexor lengthening results in improved PROs. LCL changes but does not normalize the distribution of MH pressure loading. The addition of an MCPO can prevent a significant reduction in load-sharing by the first MH.

Changes in height, weight, and body mass index after posterior spinal fusion in juvenile and adolescent idiopathic scoliosis.

Purpose: Posterior spinal fusion for idiopathic scoliosis is known to increase spinal height, but the impacts on weight and resulting body mass index are unknown. This study assesses body mass index, weight, and height percentile changes over time after posterior spinal fusion for idiopathic scoliosis. Methods: Body mass index, weight, and height age- and sex-adjusted percentiles for patients with idiopathic scoliosis undergoing posterior spinal fusion between January 2016 and August 2022 were calculated based on growth charts from the Centers for Disease Control for Disease Control and compared to preoperative values at 2 weeks, 3 months, 6 months, 1 year, and 2 years. The data were analyzed for normality with a Shapiro-Wilk test, and percentiles were compared with the Wilcoxon signed-rank tests. Results: On average, 12.1 ± 2.3 levels were fused in 269 patients 14.4 ± 1.9 years, and percentiles for body mass index, weight, and height preoperatively were 55.5 ± 29.4%, 57.5 ± 28.9%, and 54.6 ± 30.4%, respectively. Body mass index and weight percentiles decreased at 2 weeks (-10.7%, p < 0.001; -4.6%, p < 0.001, respectively) and 3 months (-6.9%, p < 0.001; -3.2%, p < 0.001, respectively) postoperatively. Postoperative weight loss at 2 weeks averaged 2.25 ± 3.09% of body weight (0.98 ± 4.5 kg), normalizing by 3 months. Body mass index percentile normalized at 1 year, but height percentile was increased at 2 weeks (2.42 ± 1.72 cm, p < 0.001) and through 2 years. Conclusion: Despite initial height increase due to deformity correction, acute postoperative weight and body mass index percentile decreases postoperatively normalize by 1-year body mass index percentile. Physicians may benefit from utilizing this information when discussing the postoperative course of posterior spinal fusion with idiopathic scoliosis. Level of evidence: 4, Retrospective Case Series.

The Perils of Sleeper Plates in Multiple Hereditary Exostosis: Tibial Deformity Overcorrection Due to Tether at Empty Metaphyseal Hole.

BACKGROUND: Hemi-epiphysiodesis is the mainstay of treatment for angular deformities at the knee in children with multiple hereditary exostosis (MHE). Upon deformity correction, the metaphyseal screw may be removed from the hemi-epiphysiodesis plate, the sleeper plate technique, with anticipated reimplantation of the metaphyseal screw should the original deformity recur. The aim of the present study is to compare the incidence of complications with the sleeper plate technique with complete plate removal in an MHE cohort. METHODS: Patients under the age of 18 with MHE who underwent hemi-epiphysiodesis of the proximal tibia and/or distal femur between February 1, 2016, and February 6, 2022 with a minimum 2-year follow-up or follow-up to skeletal maturity were identified via ICD-10 codes. Patient charts and radiographic images were reviewed to assess for the bone(s) treated, the use of sleeper plates, and whether any complication occurred, including overcorrection from bony ingrowth at the empty holes or deformity recurrence. RESULTS: In 13 patients, 19 knees underwent hemi-epiphysiodesis at 30 sites; 13 distal femoral and 17 proximal tibial. Of 30 plates, 18 (60%) were removed completely upon deformity correction and 3 (10%) did not require removal due to skeletal maturity. Four of 13 (30.8%) femoral plates and 5 of 17 (29.4%) tibial plates were left as sleeper plates. All 5 tibial sleeper plates developed bony ingrowth into the empty metaphyseal screw hole, which led to unintended progressive deformity overcorrection. In the majority of cases, the deformity was addressed by the removal of the plate and exophytic bone and hemi-epiphysiodesis on the other side of the affected proximal tibia with subsequent resolution of the deformity. CONCLUSIONS: All tibial sleeper plates developed bony ingrowth into the screwless metaphyseal hole. The bony ingrowth functioned as a tether, resulting in progressive deformity overcorrection. Sleeper plates should be avoided at the proximal tibia in patients with MHE, and extreme caution should be exercised when considering this technique at the distal femur or other sites. LEVELS OF EVIDENCE: Level III-retrospective comparative study.

High Rates of Successful Return to Competitive Athletics After Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis Regardless of Distal Fusion Level: A Prospective Cohort Study.

STUDY DESIGN: Prospective cohort. OBJECTIVE: To determine if distal spinal fusion level is associated with postoperative sport participation after posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS). SUMMARY OF BACKGROUND DATA: The concept of "saving a level" during PSF for AIS refers to minimizing the distal extent of lumbar fusion to theoretically allow for increased postoperative spinal mobility and a more predictable return to athletic activity, as well as minimizing the risk of degenerative disc disease. There are few prospective studies evaluating the correlation between distal fusion level and timing of return to sports. MATERIALS AND METHODS: Adolescent patients undergoing PSF for AIS between 2009 and 2019 were approached at their presurgical visit to participate in this prospective study. Participants were followed for a minimum of 2 years after surgery. Sports participation (classified by sport type and level of competitiveness) and radiographic data were collected at the initial visit. At each postoperative visit, it was noted whether patients returned to the same sport type and level of competitiveness. RESULTS: After an a priori power calculation was performed, a total of 106 participants were included in the analysis with a mean age of 14 ± 2 years. Distal fusion levels ranged from T11 to L4. There was no significant association between distal fusion level and return to the same level of sports participation ( P = 0.192). Of the participants, 93% returned to sports with no significant differences by distal fusion level ( P = 0.081). Distal fusion level demonstrated no difference in return to preoperative sport ( P = 0.486) or return to the same type of sport ( P = 0.247). CONCLUSIONS: This study found no association between distal fusion level and postoperative sports participation. Even though many patients may elect to change sports, nearly all patients returned to sports, and the majority of patients returned to the same level of sports competition or higher after PSF for AIS.

Rapidly acquired valgus deformity of the knee after osteochondroma resection in multiple hereditary exostoses pediatric patients: A report of two cases.

Patients with multiple hereditary exostoses (MHE) often develop leg length discrepancies and limb alignment deformity around the knee as part of the natural course of the disease. Limb alignment deformity occurring post-resection of an osteochondroma has been described in one case report and only pertaining to the proximal medial tibia location. Here we describe the case of 2 patients with MHE, a 7-year-old female who underwent resection of distal femur and proximal tibia osteochondromas and a 9-year-old female who had a distal femur osteochondroma resected. Both patients developed rapidly progressive valgus knee deformity requiring surgical intervention. Excision of osteochondromas near the physis of a skeletally immature patient can cause overgrowth from the involved side of the growth plate resulting in a rapidly progressing unilateral coronal plane deformity. Surgeons should be aware of this potential complication and closely follow growing patients with serial alignment radiographs and counsel the family regarding the potential of acquired limb deformity and subsequent surgeries.

Variability in evaluation and treatment of tibial tubercle fractures among pediatric orthopedic surgeons.

The purpose of this study was to determine the variability in clinical management of tibial tubercle fractures among a group of pediatric orthopedic surgeons. Nine fellowship-trained academic pediatric orthopedic surgeons reviewed 51 anteroposterior and lateral knee radiographs with associated case age. Respondents were asked to describe each fracture using the Ogden classification (type 1-5 with A/B modifiers), desired radiographic workup, operative vs. nonoperative treatment strategy and plans for post-treatment follow-up. Fair agreement was reached when classifying the fracture type using the Ogden classification (k = 0.39; P < 0.001). Overall, surgeons had a moderate agreement on whether to treat the fractures operatively vs. nonoperatively (k = 0.51; P < 0.001). Nonoperative management was selected for 80.4% (45/56) of type 1A fractures. Respondents selected operative treatment for 75% (30/40) of type 1B, 58.3% (14/24) of type 2A, 97.4% (74/76) of type 2B, 90.7% (39/43) of type 3A, 96.3% (79/82) of type 3B, 71.9% (87/121) of type 4 and 94.1% (16/17) of type 5 fractures. Regarding operative treatment, fair/slight agreement was reached when selecting the specifics of operative treatment including surgical fixation technique (k = 0.25; P < 0.001), screw type (k = 0.26; P < 0.001), screw size (k = 0.08; P < 0.001), use of washers (k = 0.21; P < 0.001) and performing a prophylactic anterior compartment fasciotomy (k = 0.20; P < 0.001). Furthermore, surgeons had fair/moderate agreement regarding the specifics of nonoperative treatment including degree of knee extension during immobilization (k = 0.46; P < 0.001), length of immobilization (k = 0.34; P < 0.001), post-treatment weight bearing status (k = 0.30; P < 0.001) and post-treatment rehabilitation (k = 0.34; P < 0.001). Significant variability exists between surgeons when evaluating and treating pediatric tibial tubercle fractures.

Deformity correction in thoracic adolescent idiopathic scoliosis.

AIMS: To compare the rates of sagittal and coronal correction for all-pedicle screw instrumentation and hybrid instrumentation using sublaminar bands in the treatment of thoracic adolescent idiopathic scoliosis (AIS). METHODS: We retrospectively reviewed the medical records of 124 patients who had undergone surgery in two centres for the correction of Lenke 1 or 2 AIS. Radiological evaluation was carried out preoperatively, in the early postoperative phase, and at two-year follow-up. Parameters measured included coronal Cobb angles and thoracic kyphosis. Postoperative alignment was compared after matching the cohorts by preoperative coronal Cobb angle, thoracic kyphosis, lumbar lordosis, and pelvic incidence. RESULTS: A total of 179 patients were available for analysis. After matching, 124 patients remained (62 in each cohort). Restoration of thoracic kyphosis was significantly better in the sublaminar band group than in the pedicle screw group (from 23.7° to 27.5° to 34.0° versus 23.9° to 18.7° to 21.5°; all p < 0.001). When the preoperative thoracic kyphosis was less than 20°, sublaminar bands achieved a normal postoperative thoracic kyphosis, whereas pedicle screws did not. In the coronal plane, pedicle screws resulted in a significantly better correction than sublaminar bands at final follow-up (73.0% versus 59.7%; p < 0.001). CONCLUSION: This is the first study to compare sublaminar bands and pedicle screws for the correction of a thoracic AIS. We have shown that pedicle screws give a good coronal correction which is maintained at two-year follow-up. Conversely, sublaminar bands restore the thoracic kyphosis better while pedicle screws are associated with a flattening of the thoracic spine. In patients with preoperative hypokyphosis, sublaminar bands should be used to restore a proper sagittal profile. Cite this article: Bone Joint J 2020;102-B(3):376-382.

Pediatric Septic Arthritis and Osteomyelitis in the USA: A National KID Database Analysis.

BACKGROUND: Prior reports suggest that osteoarticular infections may be increasing over time. QUESTIONS/PURPOSES: We sought to determine if incidence rates, median in-hospital costs, and length of stay (LOS) of osteomyelitis, septic arthritis (SA), and combined infections have changed over time for pediatric patients, and how they compare to previously reported rates. METHODS: The Kids' Inpatient Database (KID), a US national sample of pediatric hospital discharge records from 1997, 2000, 2003, 2006, 2009, and 2012, was used to determine yearly estimated counts of infections in children 20 years of age or younger. US census data was used to calculate yearly incidence rates. Trend tests using linear contrast analysis were used to compare estimated median LOS and inflation-adjusted median costs over time for each type of infection. RESULTS: From 1997 through 2012, the incidence rate of osteomyelitis increased from 7.9 to 10.5 per 100,000, SA was unchanged from 5.3 to 5.2 per 100, and combined infections increased from 0.8 to 1.3 per 100,000. Median LOS from 1997 to 2012 showed no significant change for osteomyelitis (5.0 to 4.9 days), SA (4.4 to 4.1 days), or combined infections (6.5 to 6.8 days). Median in-hospital costs from 1997 to 2012 increased for osteomyelitis ($7735 to $11,823), SA ($5041 to $10,574), and combined infections ($12,691 to $16,260). CONCLUSION: In pediatric patients, the estimated incidence rate of SA appeared stable, while rates of osteomyelitis and combined infections increased. These estimated rates fall within previously reported ranges. Despite stable LOS, costs have increased over time.

Biomechanical Comparison of Suture-External Button Fixation vs Internal Suspension Fixation for Tendon Transfers of the Feet.

BACKGROUND: Fixation of tendon transfers in pediatric feet typically involves passing a suture that is secured to a tendon, through an intraosseous tunnel, and tying it over an external button on the plantar foot, with appropriate tension. After adequate time is allowed for bone-tendon healing, the suture and button are removed. This construct can be complicated by suture breakage with loss of fixation, and/or skin ulceration under the button. Internal suspension systems of tendons and ligaments in adults have demonstrated excellent fixation strength and minimal intraosseous tunnel displacement, with no risk of skin ulceration and no need for suture and button removal. This study compared the biomechanical properties of the suture-external button and internal suspension fixation techniques in cadavers. The primary outcome and secondary outcomes were displacement of suture-fixation construct during dynamic loading, and static loading, respectively. METHODS: Nine adult cadaver feet were obtained. Both the external button and internal suspension techniques were tested once in each cadaver, in random order. Relative displacement of the fixation construct within the bone tunnel was recorded with video capture during dynamic and static loading. A custom Matlab script processed video and materials testing data. Static and cyclic displacements were analyzed between fixation groups using a paired t test (alpha value =0.05). RESULTS: Internal suspension fixation had significantly less mean displacement of the tendon within the bone tunnel than the external button technique during dynamic (0.3 mm internal suspension system, 0.7 mm external button, P = .0115) and static loading (0.4 mm internal suspension system, 2.2 mm external button, P = .0019). CONCLUSIONS: Internal suspension systems may provide superior fixation compared to the traditional external button for tendon transfers, with the added benefit of avoiding the risk of skin ulceration and the need for suture and button removal. CLINICAL RELEVANCE: It appears internal suspension method of tendon transfer fixation would be an acceptable alternative to traditional methods of fixation with an external button.

Incidence of Intraspinal and Extraspinal MRI Abnormalities in Patients With Adolescent Idiopathic Scoliosis.

STUDY DESIGN: Retrospective study with follow-up. OBJECTIVES: The purpose of this study was to determine the incidence of intraspinal and extraspinal MRI abnormalities in a consecutive series of patients with adolescent idiopathic scoliosis (AIS) and to describe the evaluation and management of these abnormalities. SUMMARY OF BACKGROUND DATA: Indications for preoperative magnetic resonance imaging (MRI) in patients with AIS remain controversial. Previous studies have reported a wide range of abnormality rates; however, the majority of these studies focus on a nonconsecutive series of patients, and none of these studies report the incidence of extraspinal abnormalities. METHODS: We studied a consecutive series of patients with AIS managed with spinal deformity surgery. All patients underwent a routine neural axis MRI prior to surgery. MRI reports were reviewed, and intraspinal and extraspinal abnormalities were recorded. Additional chart review and follow-up was performed to determine the rates of evaluation and management for these abnormalities. Descriptive statistics were used to describe the incidence and types of abnormalities, as well as the rates of evaluation and management. RESULTS: This study included a consecutive series of 259 patients with AIS. MRI abnormalities were noted in 115 patients (44%). After excluding patients with degenerative changes, MRI abnormalities were noted in 64 patients (25%). The incidence of Chiari malformation was 4.2% and syringomyelia was 5%. Extraspinal abnormalities were noted in 10% of patients, and these findings ranged from benign cysts to malignant soft tissue tumor. Approximately 10% of patients needed additional evaluation because of their preoperative MRI findings, and 0.7% of patients required surgical management prior to spinal deformity surgery. CONCLUSIONS: Significant MRI abnormalities were noted in patients with AIS, and some patients required further evaluation prior to surgery. Additional study including cost-effectiveness analysis is needed to better define the role of preoperative MRI in patients with AIS. LEVEL OF EVIDENCE: Level II.

The Fragility of Statistically Significant Results in Pediatric Orthopaedic Randomized Controlled Trials as Quantified by the Fragility Index: A Systematic Review.

BACKGROUND: The randomized controlled trial (RCT) is the gold standard study design allowing critical comparison of clinical outcomes while minimizing bias. Traditionally clinical trials are evaluated through statistical significance, expressed by P-values and confidence intervals. However, until recently, the robustness of a study's conclusions has been given little attention. A new metric, the fragility index, quantifies the number of patients theoretically required to switch outcomes in order to reverse the study conclusions. The primary aim of our work was to determine the fragility index of RCTs in the pediatric orthopaedic literature. The secondary aim was to determine study factors associated with lower fragility index. METHODS: Pubmed and Embase were systematically searched for pediatric orthopaedic RCTs published September 1, 2006 to September 1, 2016. Two independent reviewers screened titles, abstracts, and manuscripts to identify studies published in English involving 2 treatment arms. Trials without dichotomous primary or secondary outcomes or with patients >18 years were excluded. Data were extracted from each eligible article in duplicate and the fragility index was determined using Fisher exact test, with previously published methods. Univariate analysis was used to determine factors associated with lower fragility index. RESULTS: Seventeen trials were eligible for inclusion. The median treatment arm size was 58 and overall sample size was 116 patients. The median fragility index was 3 (range, 0 to 18). A fragility index of 3 means that just 3 patients would need to switch treatment outcomes in order for the trial results to become statistically nonsignificant. In 1 study, the number of patients lost to follow-up exceeded the fragility index, such that the study conclusions could be completely reversed purely depending on the outcomes of the patients lost to follow-up. Lower fragility index was associated with smaller patient sample sizes and greater P-values. CONCLUSIONS: The fragility index is a useful adjunct metric to the P-value and confidence intervals, allowing analysis of the robustness of study conclusions. RCTs in pediatric orthopaedics often have small sample sizes, many with low fragility indices. Future efforts could focus on encouraging institutional collaboration and patient recruitment with the ultimate goal of improving RCT sample sizes, and potentially improving the robustness of RCT results. LEVEL OF EVIDENCE: Level I.