Osseointegration reduces aseptic loosening of primary distal femoral implants in pediatric and adolescent osteosarcoma patients: a retrospective clinical and radiographic study.

AIM: The challenge of distal femoral replacement (DFR) longevity remains a priority for orthopaedic oncologists as the overall survival and activity level of young patients with osteosarcoma continues to improve. This study hypothesized that increased extracortical osseointegration at the bone-implant shoulder (i.e., where the metal implant shaft abuts the femur) will improve stress transfer adjacent to the implant, as evidenced by reduced cortical bone loss, radiolucent line progression and implant failure in young patients (< 20 years) following DFR surgery. METHODS: Twenty-nine patients of mean age 13.09 ± 0.56 years received a primary DFR. The clinical outcome of 11 CPS®, 10 GMRS®, 5 Stanmore® and 3 Repiphysis® implants was evaluated over a mean follow-up period of 4.25 ± 0.55 years. The osseous response to a bone-implant shoulder composed of either a hydroxyapatite-coated grooved ingrowth collar (Stanmore®), a porous metal coating (GMRS®) or a polished metal surface (Repiphysis®) was quantified radiographically. RESULTS: All (100.0%) of the Stanmore® implants, 90.0% of GMRS®, 81.8% of CPS® and 33.3% of the Repiphysis® implants survived. Significantly increased extracortical bone and osseointegration were measured adjacent to the Stanmore® bone-implant shoulder when compared with the GMRS® and Repiphysis® implants (p < 0.0001 in both cases). Significantly decreased cortical loss was identified in the Stanmore® group (p = 0.005, GMRS® and p < 0.0001, Repiphysis®) and at 3 years, the progression of radiolucent lines adjacent to the intramedullarly stem was reduced when compared with the GMRS® and Repiphysis® implants (p = 0.012 and 0.026, respectively). CONCLUSIONS: Implants designed to augment osseointegration at the bone-implant shoulder may be critical in reducing short- (≤ 2 years) to mid- (≤ 5 years) term aseptic loosening in this vulnerable DFR patient group. Further longer-term studies are required to confirm these preliminary findings.

Use of Telemedicine in Pediatric Orthopaedics Prior to the Pandemic: A Survey of POSNA Members.

BACKGROUND: Telemedicine, or telehealth, is broadly defined as the use of technology to deliver health care or health education at distance. Synchronous communication telemedicine, which involves the use of real time audio and video between patient and provider, is a developing field and its use in the pediatric orthopaedic population is not well defined. To better understand the existing use of and challenges posed by telemedicine for pediatric orthopaedic providers, the Pediatric Orthopaedic Society of North America (POSNA) practice management committee conducted a survey of current POSNA members. METHODS: A 33-question survey was created by the POSNA Practice Management Committee, piloted among committee members and approved by the POSNA Evidence Based Practice Committee. A total of 167 responses were complete (75% complete response rate). Telemedicine use questions referred to the use of synchronous communication telemedicine. RESULTS: A total of 50% reported being "moderately" or "not really" familiar with telemedicine. Sixty percent of study participants reported their hospital systems utilize telemedicine; however, only 40% reported utilizing telemedicine in their own practice. Sixty-seven percent indicated interest in telemedicine training. Telemedicine was utilized for a variety of patient pathology and visit types 57% of study participants did not bill for telemedicine services. Sixty-three percent were unaware of their states' billing rules regarding telemedicine. CONCLUSION: The survey is an attempt to understand the current landscape of telemedicine use within pediatric orthopaedics. Currently, a minority of survey participants utilize synchronous communication telemedicine. There is a desire for telemedicine training and best billing practices education. Further study to evaluate the limitations and efficacy of telemedicine in the pediatric orthopaedic population will be necessary as its use increases.

Electronic Medical Record Use and Satisfaction Among Pediatric Orthopaedic Surgeons.

INTRODUCTION: Electronic medical record (EMR) use among pediatric orthopaedic surgeons has evolved substantially within the past decade. In response to the Patient Protection and Affordable Care Act, large hospitals and tertiary pediatric medical centers rapidly acquired and implemented EMRs with uncertainty as to the potential impact on patient care and operational efficiency of subspecialists. This study reviews the background and regulatory framework for Meaningful Use of EMR and assesses the current landscape of EMR utilization by pediatric orthopaedic surgeons. METHODS: In 2015, the Practice Management Committee distributed a survey regarding EMR use and satisfaction to members of the Pediatric Orthopaedic Society of North America. Survey responses from 324 members were used to analyze levels of satisfaction by EMR platform and practice type and to consider drivers of satisfaction or dissatisfaction of end users. RESULTS: Although there were no differences in overall satisfaction based on vendor or practice type, significant differences were noted for 5 specific parameters of satisfaction, including: usefulness of templates, efficiency of practice workflow, information services support, number of logon events, and speed of the system. A user/vendor map is provided to facilitate networking among providers and groups utilizing common EMR platforms to help bring about rational improvements in EMR functionality for the future. CONCLUSIONS: Substantial effort needs to be made to improve subspecialty-specific EMR documentation, order entry, research tools, and clinical workflows to enhance the processes of care for children with orthopaedic conditions in the era of EMR. LEVEL OF EVIDENCE: Level IV.

Prolonged perioperative infusion of low-dose ketamine does not alter opioid use after pediatric scoliosis surgery.

BACKGROUND: Opioid consumption after posterior spinal fusion is known to be high and often exceeds those reported in other major surgical procedures. A number of clinical trials provide evidence that the perioperative use of subanesthetic doses of ketamine reduces pain and opioid requirements in some surgical procedures, but the effect of prolonged perioperative low-dose ketamine infusion in patients undergoing posterior spinal fusion for pediatric scoliosis surgery is unknown. OBJECTIVE: To test the hypothesis that a 72-h perioperative low-dose ketamine infusion would decrease opioid use in pediatric patients undergoing posterior spinal fusion. METHODS: In a double-blind prospective controlled trial, patients undergoing posterior spinal fusion for scoliosis were randomized to receive perioperative low-dose ketamine or placebo control. Patients received general anesthesia, intraoperative remifentanil, and morphine patient-controlled analgesia postoperatively. Daily opioid consumption, self-reported pain scores, and sedation scores were measured. RESULTS: Fifty-four patients were enrolled and 50 completed the study. Contrary to our hypothesis, ketamine- and control-treated patients had similar postoperative opioid use, pain scores, and sedation scores measurements. In contrast, ketamine-treated patients required less intraoperative remifentanil compared with control (mean 2.9 mg vs. 4 mg, P = 0.0415). Number of vertebrae instrumented, time between end-of-surgery and 24 h assessment, or remifentanil doses did not impact on postoperative opioid use. Over 96-h postoperatively, morphine-equivalent consumption was lower (-0.40, P = 0.006) and sedation score was higher (0.47, P = 0.0211) in male patients, compared with female patients. CONCLUSIONS: These findings do not support the use of perioperative low-dose ketamine to decrease opioid use in children with scoliosis undergoing posterior spinal fusion.

No Value Found With Routine Early Postoperative Radiographs after Implant Removal in Pediatric Patients.

BACKGROUND: Implants are routinely removed in pediatric patients. Fracture through the prior implant site is a common worry after implant removal. Early post-implant removal radiographs are routinely used to evaluate the prior implant removal sites and to assess when a patient may return to normal activities. To our knowledge, the value of early, routine postoperative radiographs after elective implant removal in pediatric patients has not been studied. METHODS: A retrospective patient cohort of pediatric patients who had implant removal from an extremity from 2017 to 2019 was used in this study. Data were collected for patient demographics, implant site, reason for primary surgery, complications, number of postoperative radiographs, radiation exposure, cost of imaging, and whether the postoperative plan was changed by imaging. RESULTS: Two hundred ninety patients were included in the study. Postoperative plans were changed only in 0.69% of patients (n = 2) because of abnormal 2-week radiographs and 1.72% (n = 5) because of abnormal 6-week radiographs. However, the event's proportion difference (change of management) was not statically significant ( P = 0.182) between those who had a radiograph obtained and those who did not. The mean follow-up time was 16 months. The mean number of postoperative radiographs obtained was 3.74, the mean cost per radiograph was $103, and the mean postoperative radiation exposure was 1.34 mSv. No fractures were observed after implant removal. DISCUSSION: A retrospective review of the value of early, postoperative radiographs after routine orthopaedic implant removal found that postoperative radiographs at 2 and 6 weeks did not change the postoperative plan for most of the patients. Postoperative radiographs have an average cost of $103, and radiation exposure equal to approximately 6 months of natural background radiation. LEVEL OF EVIDENCE: Level III.

Viscoelastic Hemostatic Assays for Orthopedic Trauma and Elective Procedures.

The application of viscoelastic hemostatic assays (VHAs) (e.g., thromboelastography (TEG) and rotational thromboelastometry (ROTEM)) in orthopedics is in its relative infancy when compared with other surgical fields. Fortunately, several recent studies describe the emerging use of VHAs to quickly and reliably analyze the real-time coagulation and fibrinolytic status in both orthopedic trauma and elective orthopedic surgery. Trauma-induced coagulopathy-a spectrum of abnormal coagulation phenotypes including clotting factor depletion, inadequate thrombin generation, platelet dysfunction, and dysregulated fibrinolysis-remains a potentially fatal complication in severely injured and/or hemorrhaging patients whose timely diagnosis and management are aided by the use of VHAs. Furthermore, VHAs are an invaluable compliment to common coagulation tests by facilitating the detection of hypercoagulable states commonly associated with orthopedic injury and postoperative status. The use of VHAs to identify hypercoagulability allows for an accurate venous thromboembolism (VTE) risk assessment and monitoring of VTE prophylaxis. Until now, the data have been insufficient to permit an individualized approach with regard to dosing and duration for VTE thromboprophylaxis. By incorporating VHAs into routine practice, orthopedic surgeons will be better equipped to diagnose and treat the complete spectrum of coagulation abnormalities faced by orthopedic patients. This work serves as an educational primer and up-to-date review of the current literature on the use of VHAs in orthopedic surgery.

Minimum 5-year radiographic results of long scoliosis fusion in juvenile spinal muscular atrophy patients: major curve progression after instrumented fusion.

BACKGROUND: Previous studies reported on spinal muscular atrophy (SMA) scoliosis surgery outcomes without focus on major curve progression (MCP). The purpose of this study was to assess minimum 5-year radiographic outcomes, MCP, and factors for MCP after spinal surgery in juvenile SMA patients with open triradiate cartilage at the time of surgery. METHODS: Retrospective review of radiographic and clinical data of 22 SMA patients treated surgically at 3 institutions over 20 years was performed. Major curve Cobb angle, apical vertebral translation, pelvic obliquity, coronal balance, and sagittal Cobb angles (T5-T12 and T12-sacrum) were measured at preoperative, initial, and ultimate follow-up. MCP was defined as an increase in Cobb angle of ≥ 10 degrees between initial and ultimate follow-up. RESULTS: Overall, SMA patients had significant improvement in radiographic measurements at follow-up. Eight patients (36%) developed MCP and were similar in age (7.8 vs. 8.8 y, P=0.09) to non-MCP patients. Initial major curve Cobb angle correction was greater for MCP patients than for non-MCP patients (19 vs. 36 degrees, P=0.004). MCP patients lost 26 degrees (P=0.001) and non-MCP patients lost 2 degrees of major curve Cobb angle correction during follow-up. Both groups had similar ultimate follow-up radiographic outcomes and remained improved from preoperative deformity. All 14 non-MCP patients had long posterior instrumentation (T4 or higher to sacrum/pelvis), whereas all 4 patients with short posterior instrumentation developed MCP. Six patients underwent anterior-posterior spinal fusion (ASF-PSF) and had greater preoperative deformity than PSF-only patients, but ultimate major curve Cobb angle (38 vs. 44 degrees, P=0.4) was similar for both the groups. Two ASF-PSF patients developed MCP. CONCLUSIONS: Overall, SMA patients maintained scoliosis correction with nonpedicle screw-based (predominantly Luque-Galveston instrumentation) long spinal instrumentation at minimum 5-year follow-up. MCP >10 degrees developed in 36%, contrary to our expectation of 100% in these young juvenile SMA patients. All non-MCP patients had instrumentation from the upper thoracic spine (T1 to T4) to the sacrum, whereas all 4 patients with short instrumentation developed MCP. MCP and non-MCP patients had similar ultimate correction and remained improved from preoperative deformity. Skeletal immaturity and length of posterior instrumentation may influence MCP in SMA scoliosis surgery and should be considered during preoperative planning. LEVEL OF EVIDENCE: Case Series; Level IV.

Incidence of Osteolysis and Aseptic Loosening Following Metal-on-Highly Cross-Linked Polyethylene Hip Arthroplasty: A Systematic Review of Studies with Up to 15-Year Follow-up.

BACKGROUND: This study compared the incidence of osteolysis, aseptic loosening, and revision following use of highly cross-linked polyethylene (HXLPE) or conventional polyethylene (CPE) at medium to long-term (>5 to 15 years) follow-up in primary total hip arthroplasty (THA). Incidences were quantified and compared with regard to age and method of implant fixation. METHODS: Using the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines, 12 randomized controlled trials and 18 cohort studies were investigated for evidence-based outcomes following HXPLE and CPE use in 2,539 hips over a 5 to 15-year follow-up. RESULTS: Lower rates of osteolysis, aseptic loosening, and implant revision were reported following use of HXLPE liners. Osteolysis was reduced from 25.4% with CPE to 4.05% with HXLPE in young patients, and from 29.7% to 6.6% in the older patient cohort. Similarities in osteolysis rates were observed when cemented (24.9% for CPE and 6.5% for HXLPE) and uncemented components (32.8% for CPE and 7.1% for HXLPE) were compared. No clear advantage in the type of HXLPE used was observed. CONCLUSIONS: Over a follow-up period of up to 15 years, when compared with CPE, use of HXLPE liners reduced the incidence of osteolysis, aseptic loosening, and implant revision, regardless of the fixation method and including in younger and potentially more active patients. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Lactobacillus cell-free supernatant as a novel bioagent and biosurfactant against Pseudomonas aeruginosa in the prevention and treatment of orthopedic implant infection.

The hypothesis was that probiotic Lactobacillus species (spp.) or their cell-free supernatant (CFS) are effective in inhibiting (a) planktonic growth of Pseudomonas aeruginosa (PA), (b) its adhesion to a Ti6Al4V-alloy surface, and (c) in dispersing biofilm once formed. (a) A planktonic co-culture containing PA(104 colony-forming unit [CFU]/ml) was combined with either Lactobacillus acidophilus, Lactobacillus plantarum (LP), or Lactobacillus fermentum (LF) at a suspension of 104 (1:1) or 108 CFU/ml (1:2). Lactobacillus and PA CFUs were then quantified. (b) Ti-6Al-4V discs were inoculated with PA followed by supplementation with CFS and adherent PA quantified. (c) Biofilm covered discs were supplemented with Lactobacillus CFS and remaining PA activity quantified. Results showed that whole-cell cultures were ineffective in preventing PA growth; however, the addition of CFS resulted in a 99.99 ± 0.003% reduction in adherent PA in all Lactobacillus groups (p < .05 in all groups) with no viable PA growth measured in the LF and LP groups. Following PA biofilm formation, CFS resulted in a significant reduction in PA activity in all Lactobacillus groups (p ≤ .05 in all groups) with a 29.75 ± 15.98% increase measured in control samples. Supplementation with CFS demonstrated antiadhesive, antibiofilm, and toxic properties to PA.

Comparison of Pain Scores and Medication Usage Between Three Pain Control Strategies for Pediatric Anterior Cruciate Ligament Surgery.

Introduction Assessment and management of postoperative pain in the pediatric population after anterior cruciate ligament (ACL) surgery can be challenging; the optimal approach to pain control remains controversial. Recent studies show that use of intraoperative nerve blocks may reduce the need for opioids to control pain in the postoperative period. However, it is unclear which block type is most beneficial in the pediatric outpatient setting. This study compared effectiveness of pain control among three different pain management strategies. Methods We retrospectively reviewed charts of patients aged 12-17 years who received an elective ACL reconstruction between 2013 and 2017. The three groups were femoral nerve block, combined femoral and sciatic block, and intraarticular injection of bupivacaine (n = 50 per group). The primary variable was postoperative pain scores (visual analog scale 1-10) in the postanesthesia care unit (PACU). Results Less than 50% of patients in the combined nerve block group had opioids intraoperatively or in the PACU compared with nearly 100% of patients in the other two groups (p < 0.0001). Also, for patients receiving opioids, the total intraoperative morphine equivalents and PACU pain scores (all patients) were significantly less in the combined block group (p < 0.001). For patients receiving opioids in the PACU, the total morphine equivalents were significantly higher in the intraarticular injection group compared with the nerve block groups (p < 0.0001). Conclusion Patients in the combined femoral and sciatic nerve block group had significantly better pain scores in the PACU with less cumulative morphine equivalent consumption compared with the femoral nerve block group and the intraarticular injection group.

The Use of Emergency Physicians to Deliver Anesthesia for Orthopaedic Surgery in Austere Environments: The Expansion of the Emergency Physician's General Anesthesia Syllabus to Orthopaedic Surgery.

BACKGROUND: Five billion people, primarily in low-income and middle-income countries, cannot access safe, affordable surgical and anesthesia care, particularly for orthopaedic trauma. The rate-limiting step for many orthopaedic surgical procedures performed in the developing world is the absence of safe anesthesia. Even surgical mission teams providing surgical care are limited by the availability of anesthesiologists. Emergency physicians, who are already knowledgeable in airway management and procedural sedation, may be able to help to fulfill the need for anesthetists in disaster relief and surgical missions. METHODS: Following the 2010 earthquake in Haiti, an emergency physician was trained using the Emergency Physician's General Anesthesia Syllabus (EP GAS) to perform duties similar to those of certified registered nurse anesthetists. The emergency physician then provided anesthesia during surgical mission trips with an orthopaedic team from February 2011 to March 2017, in Milot, Haiti. This is a descriptive overview of this training program and prospectively collected data on the cohort of patients whom the surgical mission teams treated in Haiti during that time frame. RESULTS: A single emergency physician anesthetist provided anesthesia for 71 of the 172 orthopaedic surgical cases, nearly doubling the number of cases that could be performed. This also allowed the anesthesiologists to focus on pediatric and more difficult cases. Both immediately after the surgical procedure and at 1 year, there were no serious adverse events for cases in which the emergency physician provided anesthesia. CONCLUSIONS: Given emergency physicians' baseline training in airway management and sedation, well-supervised and focused extra training under the vigilant supervision of a board-certified anesthesiologist may allow emergency physicians to be able to safely administer anesthesia. Using emergency physicians as anesthetists in this closely supervised setting could increase the number of surgical cases that can be performed in a disaster setting.

Combined posterior Bankart lesion and posterior humeral avulsion of the glenohumeral ligaments associated with recurrent posterior shoulder instability.

Recurrent posterior glenohumeral instability is uncommon and is often misdiagnosed. Damage to the posterior capsule, posteroinferior glenohumeral ligament, and posterior labrum have all been implicated as sources of traumatic posterior instability. We describe a case of traumatic recurrent posterior instability resulting from a posterior Bankart lesion accompanied by posterior humeral avulsion of the glenohumeral ligaments. The Bankart lesion was repaired using a single arthroscopic suture anchor at the glenoid articular margin. The posterior humeral avulsion of the glenohumeral ligaments was addressed with 3 suture anchors placed at the capsular origin at the posterior humeral head. Using these anchors, the posterior capsule was advanced laterally and superiorly for a secure repair. Arthroscopic anatomic reconstruction of both lesions resulted in an excellent clinical outcome.

How Is Pulmonary Function and Exercise Tolerance Affected in Patients With AIS Who Have Undergone Spinal Fusion?

STUDY DESIGN: Prospectively enrolled AIS patients who underwent spinal fusion, with 2 year follow-up. OBJECTIVES: To evaluate the cardiovascular fitness and activity level in patients with AIS pre- and post-spinal fusion and to determine if initial curve magnitude or pulmonary function is predictive of exercise capacity. SUMMARY OF BACKGROUND DATA: Researchers have tried to link pulmonary function testing (PFT) to exercise capacity; the results are mixed. Some report no improvement in PFTs or aerobic activity after surgical correction, and PFT measures were not predictive of exercise capacity. Conflicting results have shown Vo2max results to fall within normal range in AIS patients while PFTs show minimal impairment. METHODS: AIS patients underwent PFT and oxygen consumption (VO2) testing during a submaximal graded exercise test (GXT) pre- and post-spinal fusion. Vo2max was predicted in those patients who completed the test to 85% of maximal heart rate. Pre- to postoperative changes were assessed and then compared to age-matched control subjects. Correlations between Vo2max and curve severity, pulmonary function, and activity level were assessed. RESULTS: Thirty-seven patients participated. Vo2max was predicted in 23 patients pre- and postoperation. There was a significant reduction in Vo2max postfusion (39.5 ± 6.5 mL/kg/min vs 42.1 ± 8.1 mL/kg/min, p = .033); however, compared with controls (40.5 ± 6.5 mL/kg/min), all data were within the normal range (p > .05). AIS patients reporting high activity had significantly greater Vo2max than those reporting low activity both pre and postoperatively, but this difference only met statistical significance preop (p < .05). Curve magnitude and PFT measures were not found to correlate with Vo2max (p > .05). CONCLUSIONS: Vo2max in patients with AIS is within normal range both pre- and postfusion. Pulmonary limitations are accommodated for with a slightly increased breathing rate and a slightly reduced overall workload. Activity level rather than curve severity affects Vo2max outcomes following fusion in AIS.

Sim2 contributes to neuroendocrine hormone gene expression in the anterior hypothalamus.

Paraventricular (PVN) and supraoptic nuclei of the hypothalamus maintain homeostasis by modulating pituitary hormonal output. PVN and supraoptic nuclei contain five major cell types: oxytocin-, vasopressin-, CRH-, somatostatin-, and TRH-secreting neurons. Sim1, Arnt2, and Otp genes are essential for terminal differentiation of these neurons. One of their common downstream genes, Brn2, is necessary for oxytocin, vasopressin, and CRH cell differentiation. Here we show that Sim2, a paralog of Sim1, contributes to the expression of Trh and Ss genes in the dorsal preoptic area, anterior-periventricular nucleus, and PVN. Sim2 expression overlaps with Trh- and Ss-expressing cells, and Sim2 mutants contain reduced numbers of Trh and Ss cells. Genetically, Sim1 acts upstream of Sim2 and partially compensates for the loss of Sim2. Comparative expression studies at the anterior hypothalamus at early stages reveal that there are separate pools of Trh cells with distinctive molecular codes defined by Sim1 and Sim2 expression. Together with previous reports, our results demonstrate that Sim1 and Otp utilize two common downstream genes, Brn2 and Sim2, to mediate distinctive sets of neuroendocrine hormone gene expression.

Complications and Predictors of Need for Return to the Operating Room in the Treatment of Supracondylar Humerus Fractures in Children.

UNLABELLED: Supracondylar humerus fractures are common pediatric injuries. Little is known about the risk factors for repeat operative procedures. A retrospective chart review of 709 patients treated for a displaced supracondylar humerus fracture was performed to identify risk factors for return to the operating room during the initial post-operative period. Deviations of routine fracture care were recorded and complication rates were compared between Gartland type 2 and 3 fractures using logistic regression. Type 3 fractures were found to have a higher complication rate, and, specifically, more peri-operative nerve palsies, more likely to need to return to the operating room for hardware removal, to lose fracture reduction, and require a return to the operating room for any reason. Five risk factors which may require returning to the operating room were identified: younger patient age, left sided fractures, type 3 fractures, peri-operative nerve palsy, and post-operative infection. In conclusion, Gartland type 3 supracondylar humerus fractures are associated with more complications then type 2 fractures. Risk factors for the need to return to the operating room in the post-operative period include: younger patient age, left sided fractures, type 3 fractures, peri-operative nerve palsy, and post-operative infection. Patients with these risk factors should be considered at risk for return to the OR and fracture fixation and follow up protocols should be adjusted for this risk. LEVEL OF EVIDENCE: Prognostic Study, Level II.

Interactive initialization of 2D/3D rigid registration.

PURPOSE: Registration is one of the key technical components in an image-guided navigation system. A large number of 2D/3D registration algorithms have been previously proposed, but have not been able to transition into clinical practice. The authors identify the primary reason for the lack of adoption with the prerequisite for a sufficiently accurate initial transformation, mean target registration error of about 10 mm or less. In this paper, the authors present two interactive initialization approaches that provide the desired accuracy for x-ray/MR and x-ray/CT registration in the operating room setting. METHODS: The authors have developed two interactive registration methods based on visual alignment of a preoperative image, MR, or CT to intraoperative x-rays. In the first approach, the operator uses a gesture based interface to align a volume rendering of the preoperative image to multiple x-rays. The second approach uses a tracked tool available as part of a navigation system. Preoperatively, a virtual replica of the tool is positioned next to the anatomical structures visible in the volumetric data. Intraoperatively, the physical tool is positioned in a similar manner and subsequently used to align a volume rendering to the x-ray images using an augmented reality (AR) approach. Both methods were assessed using three publicly available reference data sets for 2D/3D registration evaluation. RESULTS: In the authors' experiments, the authors show that for x-ray/MR registration, the gesture based method resulted in a mean target registration error (mTRE) of 9.3 ± 5.0 mm with an average interaction time of 146.3 ± 73.0 s, and the AR-based method had mTREs of 7.2 ± 3.2 mm with interaction times of 44 ± 32 s. For x-ray/CT registration, the gesture based method resulted in a mTRE of 7.4 ± 5.0 mm with an average interaction time of 132.1 ± 66.4 s, and the AR-based method had mTREs of 8.3 ± 5.0 mm with interaction times of 58 ± 52 s. CONCLUSIONS: Based on the authors' evaluation, the authors conclude that the registration approaches are sufficiently accurate for initializing 2D/3D registration in the OR setting, both when a tracking system is not in use (gesture based approach), and when a tracking system is already in use (AR based approach).

A prospective multicenter study of Legg-Calvé-Perthes disease: functional and radiographic outcomes of nonoperative treatment at a mean follow-up of twenty years.

BACKGROUND: Long-term studies have indicated good outcomes for most patients with Legg-Calvé-Perthes disease. However, clinical experience suggests that less favorable outcomes are common. We sought to prospectively document pain and function in a cohort of adults who had previously been treated nonoperatively for Legg-Calvé-Perthes disease. METHODS: Patients in our region with Legg-Calvé-Perthes disease were enrolled between 1984 and 1991 as part of a multicenter prospective trial and were treated with hip range-of-motion exercises or bracing. Patients returned for physical examination, radiographs, and completion of outcome measures including the Nonarthritic Hip Score (NAHS) and the Iowa Hip Score (IHS). RESULTS: Fifty-six patients (fifty-eight hips) were examined at a mean of 20.4 years (range, 16.3 to 24.5 years) after enrollment. The mean NAHS was 79 (range, 35 to 100), and the mean IHS was 74 (range, 43 to 100). Three patients had required hip arthroplasty and one patient had required a pelvic osteotomy. Fourteen (26%) of the remaining hips had no hip osteoarthritis, sixteen (30%) had mild osteoarthritis (Tönnis grade 1), and twenty-four (44%) had moderate or severe osteoarthritic changes on radiographs (grade 2 or 3). Femoroacetabular impingement indicated by physical examination was associated with pain and with poorer outcomes on the IHS and the NAHS (p = 0.0004, 0.0014, and 0.0007, respectively). The Stulberg classification was significantly associated with impingement on physical examination (p = 0.0495), the NAHS (p = 0.003), and the Tönnis grade (p = 0.012). Multivariate logistic regression showed that only the Stulberg classification was significantly associated with the NAHS (p = 0.0032); the odds ratio for a Stulberg type of I or II compared with IV or V in patients with a fair or poor NAHS was 0.101 (95% confidence interval, 0.018 to 0.573). CONCLUSIONS: Pain, arthritis, and ongoing hip dysfunction are common in patients with Legg-Calvé-Perthes disease that was treated nonoperatively. Hips rated as Stulberg type III or IV more frequently had poor or fair outcomes on the IHS and NAHS (61% and 72% for type III and 77% and 60% for type IV). Patients with a lateral pillar type of B, B/C, or C frequently had pain and radiographic evidence of osteoarthritis. Clinical signs of femoroacetabular impingement were associated with pain and with lower functional scores. This prospective study establishes a modern benchmark for outcomes following nonoperative, weight-bearing treatment of Legg-Calvé-Perthes disease.

Scapulothoracic dissociation secondary to major shoulder trauma.

Three skeletally immature patients with scapulothoracic dissociation were reviewed. A 5-year-old child's arm, caught in a conveyor belt, led to complete upper extremity amputation. Multiple fractures, muscular damage, and cutaneous and subcutaneous tissue disruption (degloving) were present throughout the avulsed extremity. Replantation was considered, but not carried out because of these extensive injuries. He was treated with a myoelectric prosthesis. Two older boys had scapulothoracic dissociation (one open, one closed) associated with clavicular diaphyseal fractures following blunt trauma. In each case, the clavicle was stabilized, muscular disruptions were reattached, and bleeding was controlled locally, although no specific major vascular repair was required. There was no return of neurologic function, leaving each patient with a flail upper extremity. One patient and his family eventually elected to have a shoulder disarticulation followed by fitting with a myoelectric prosthesis. The other patient still had a flail extremity at his last evaluation 17 months postinjury, but did not return for subsequent evaluation.