The impact of study type and sleep measurement on oxygen desaturation index calculation.

STUDY OBJECTIVES: The oxygen desaturation index (ODI) is an important measure of sleep-disordered breathing during polysomnography (PSG); however, the AASM Manual (V3) does not specify whether to include oxygen desaturations occurring during wake epochs. Additionally, an ODI obtained from PSG can differ from an ODI using home sleep apnea tests (HSATs) that do not measure sleep, hampering diagnostic and treatment decision reliability. This study aimed to (1) compare an ODI that included all desaturations with an ODI that excluded desaturations occurring during wake epochs in PSG and (2) compare ODIs obtained from PSG with HSAT. METHODS: 100 consecutive PSGs for investigation of obstructive sleep apnea were compared. ODIs were calculated including all desaturations (ODIall) and by excluding desaturations entirely during wake epochs (ODIsleep). Additionally, we compared ODIall with an ODI calculated using monitoring time as the denominator (ODIHSAT). RESULTS: The median (interquartile range) 3% ODI for ODIall was 22.8 (13.1, 44.1) events/h and ODIsleep was 17.6 (11.5, 35.2) events/h (median difference: -3.9 events/h [-8.2, -0.9]; 21.0% [8.7%, 33.2%]). This discrepancy was larger with increasing ODI and decreasing sleep efficiency. The ODIHSAT was 17.4 (11.3, 35.2) events/h and the median reduction in ODIHSAT vs ODIall was -4.5 (-10.9, -2.0) events/h (21.6%; 11.1%, 33.8). CONCLUSIONS: ODI was significantly reduced when desaturations in wake epochs were excluded, and when ODI was based on monitoring time rather than sleep time, with the potential for underestimation of disease severity. Results suggest that ODI can differ substantially depending on the calculation and study type used, and that there is a need for standardization to ensure consistent diagnosis and treatment outcomes. CITATION: Whenn CB, Wilson DL, Ruehland WR, Churchward TJ, Worsnop C, Tolson J. The impact of study type and sleep measurement on oxygen desaturation index calculation. J Clin Sleep Med. 2024;20(5):709-717.

Outcomes of Adolescent T-condylar Fractures: Kids Do Not Always Make You Look Good.

BACKGROUND: Optimal treatment for pediatric and adolescent T-condylar fractures remains poorly understood. We sought to assess how functional outcomes and range of motion (ROM) after surgical fixation of T-condylar fractures are affected by patient and surgical factors. METHODS: This is a retrospective cohort study of 52 patients with operatively treated T-condylar fractures at a single tertiary pediatric referral center between 2003 and 2021. All patients younger than 18 at the time of injury with a radiographically confirmed diagnosis were included. RESULTS: Fifty-two T-condylar fractures were included, with a mean patient age of 12.9 years (SD, 2.8). The cohort was 65% male. Nine (19%) fractures were open, 46% (24/52) were AO type C2, and 33% (17/52) occurred in skeletally mature individuals. The surgical approach was through olecranon osteotomy in 29% (15/52) of patients, and fixation included anatomically specific plates and screws in 42% (22/52) of patients. In our cohort, 46% (24/52) achieved good outcomes based on Jarvis ROM criteria and 42% (22/52) achieved good to excellent results based on Roberts functional criteria. The median loss of ROM was 58 degrees at 6 weeks, 20 degrees at 3 and 6 months, and 8 degrees at 1 year postoperatively. We observed a complication rate of 54% (28/52). Patients undergoing adult-type plate fixation had better postoperative range of motion at 6 weeks (ROM loss 52 vs. 80 degrees, P =0.03) and 3 months (10 vs. 35 degrees P =0.004) compared with pediatric-type fixation and trended towards better functional outcomes. We did not identify significant differences in functional outcome scores or complication rates with respect to surgical approach or skeletal maturity. CONCLUSIONS: Surgical fixation of pediatric and adolescent T-condylar fractures achieved a good to excellent functional outcome in only a minority of patients (46% Jarvis / 42% Roberts) with a high rate of postoperative complications (54%). Future work is needed to elucidate optimal treatment to minimize complications and achieve the best functional outcomes in these challenging fractures. LEVEL OF EVIDENCE: Level-IV.

Donor-Site Morbidity for Iliac Crest Harvesting for Pediatric Scaphoid Nonunion.

PURPOSE: Screw fixation with iliac crest bone grafting (ICBG) is a well-studied treatment for pediatric scaphoid nonunions. Studies in adults, as well as in pediatric spine fusions, have demonstrated high rates of complications with ICBG, including longer-term donor site pain. We hypothesized that in pediatric patients undergoing ICBG for scaphoid nonunion, the donor site complication rate would be lower than that reported in other populations. METHODS: Records of patients ages 0-18 years at a single institution undergoing surgical reconstruction for scaphoid nonunion from 1995 to 2016 were reviewed. Patient and surgical variables were recorded, including how ICBG was harvested. Donor site complications were recorded, including donor site pain beyond 30 days after surgery, infection, peri-incisional or lower extremity numbness at any point after surgery and reoperation at the donor site at any time point after surgery. RESULTS: During the study period, 119 wrists in 117 patients underwent internal fixation and ICBG for scaphoid nonunion. The average age was 16 years; mean follow-up was 1 year. The majority of wrists (73, 62.9%) underwent harvest of both outer and inner tables of the iliac crest; 38 (31.9%) had only outer table harvested; 5 (4.3%) had only cancellous graft harvested. Ten wrists (8.4%) had a donor site complication. The most common donor site complication was donor site pain beyond 30 days after surgery (5, 4.2%), followed by numbness (4, 3.4%). No infections, seromas, or reoperations at the donor site occurred. In comparison to those subjects who did not experience complications, we found no difference based on the age at surgery or the type of graft used. Female patients were more likely to have a recorded complication than males. CONCLUSIONS: Donor site morbidity for iliac crest grafting in pediatric patients undergoing scaphoid nonunion surgery appears to be lower than that previously reported in adult patients. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Anxiety surrounding supracondylar humerus pin removal in children.

Purpose: The purpose of this study was to quantify the anxiety experienced by patients undergoing pin removal in clinic following closed reduction and percutaneous pinning for supracondylar humerus fractures. Methods: We prospectively enrolled 53 patients (3-8 years) treated for supracondylar humerus fracture with closed reduction and percutaneous pinning between July 2018 and February 2020. Demographic and injury data were recorded. Heart rate and the Face, Legs, Activity, Cry, and Consolability scale were measured immediately before pin removal and after pin removal, and crossover control values were obtained at the subsequent follow-up clinic visit. Results: All patients experienced anxiety immediately prior to pin removal (95% confidence interval, 94%-100%) with a median Face, Legs, Activity, Cry, and Consolability score of 7 (interquartile range, 6-8). In addition, 98% of subjects experienced an elevated heart rate (95% confidence interval, 88%-100%). Patients experienced a median 73% reduction in Face, Legs, Activity, Cry, and Consolability score and mean 21% reduction in heart rate from prior to pin removal to after pin removal (p < 0.001). All 45 patients who completed their follow-up visit had a control Face, Legs, Activity, Cry, and Consolability score of 0 and a mean control heart rate of 89.7 bpm. Twenty-five of these 45 subjects (56%) had an elevated control heart rate for their age and sex. Mean heart rate prior to pin removal was 36% higher than control heart rate. There were no sex differences detected in Face, Legs, Activity, Cry, and Consolability scores or heart rate. Conclusions: Pediatric patients experience high levels of anxiety when undergoing pin removal following closed reduction and percutaneous pinning for supracondylar humerus fractures. This is an area of clinical practice where intervention may be warranted to decrease patient anxiety. Level of evidence: II.

Closed Reduction and Immobilization of Pediatric Fifth Metacarpal Neck Fractures.

BACKGROUND: There is no clear consensus for the criteria for closed treatment of metacarpal neck fractures. Our objective was to determine whether closed reduction of pediatric fifth metacarpal neck fractures results in a clinically meaningful improvement in radiographic angulation. METHODS: We performed a retrospective cohort study of pediatric patients with fifth metacarpal neck fractures treated with closed reduction. Radiographs were examined for sagittal fracture angulation measured post-reduction, 2 to 14 days post-reduction, and 21 to 35 days post-reduction. We compared the angulation for open versus closed physes, initial fracture angulation greater than or less than 50°, and immobilization in extension versus intrinsic-plus position. RESULTS: Fifty-four subjects were included with an average age of 14.8 years at the time of injury and a mean initial fracture angulation of 42.7°. The improvement in fracture angulation was 8.3° (90% confidence interval [CI], 5.9-10.7) on post-reduction radiographs, 8.5° (90% CI, 6.1-10.9) at 2 to 14 days post-reduction, and 4.3° (90% CI, 1.4-7.2) at 21 to 35 days post-reduction. Subgroup analysis showed that patients with injury angle greater than or equal to 50° had significantly higher mean reductions than those with injury angle less than 50°. In this group, angulation improved 15.6° (90% CI, 8.5-22.7) post-reduction, 15.1° (90% CI, 10.1-20.1) at 2 to 14 days post-reduction, and 16.5° (90% CI, 10.4-22.6) at 21 to 35 days post-reduction. CONCLUSIONS: Closed reduction of pediatric fifth metacarpal neck fractures with initial fracture angulation less than 50° may not meaningfully improve sagittal alignment. For fractures with initial angulation greater than or equal to 50°, closed reduction resulted in clinically important, statistically significant, and lasting improvements of 16.5°.

Surgical Reconstruction of Missed Monteggia Lesions in Children.

BACKGROUND: Chronic Monteggia lesions in children may cause pain, deformity, decreased range of motion, and neurological symptoms. Numerous surgical techniques have been advocated to reconstruct long-standing Monteggia injures in efforts to maximize long-term upper limb function. The purpose of this investigation was to assess the clinical and radiographic results of a modified surgical technique for missed Monteggia fracture-dislocations. METHODS: A retrospective evaluation of 52 patients who underwent surgical reconstruction of missed Monteggia fracture-dislocations at a tertiary pediatric hospital was performed. The median patient age at the time of surgery was 6.8 years, and the median time from injury to surgery was 12.9 weeks. Electronic medical records, including clinic notes, radiographic images, and operative reports, were reviewed for study analysis. Median clinical and radiographic follow-up was 19.1 months. RESULTS: The median elbow range of motion improved from 108 degrees of flexion and 5 degrees short of full extension preoperatively to 140 degrees of flexion (P<0.001) and full extension (P=0.10) postoperatively. Forearm range of motion also improved from a median of 80 degrees of pronation and 58 degrees of supination preoperatively to 80 degrees of pronation (P=0.54) and 80 degrees of supination (P<0.001) postoperatively. Congruent radiocapitellar alignment was maintained in 39 patients (75%). Nine patients (17%) had redislocation of the radiocapitellar joint, and 4 patients (8%) had radiographic resubluxation. Six of the 9 patients who experienced redislocation underwent early revision and achieved uncomplicated longer term results. Patients who received repair of the native annular ligament were more likely to achieve lasting radiocapitellar joint stability (P=0.03) when compared with patients who received annular ligament reconstruction or if the annular ligament was not addressed. CONCLUSION: Meaningful improvements in elbow motion and radiocapitellar stability can be safely achieved in the majority of children following surgical reconstruction of missed Monteggia lesions. LEVEL OF EVIDENCE: Level IV-retrospective case series.

Single-Bone Forearm as a Salvage Procedure in Recalcitrant Pediatric Forearm Pathologies.

PURPOSE: To report on the outcome of single-bone forearm reconstruction (SBFR) as a salvage procedure in pediatric forearm pathologies. METHODS: Twenty-eight forearms in 27 patients (median age, 9.6 years; range, 3.4-29.7 years) treated with SBFR at a pediatric referral center were included in the study. Records and radiographs were retrospectively analyzed. Median follow-up was 84 months (range, 24-261 months). The most common underlying condition was multiple hereditary exostoses (MHEs) (17 of 28), followed by brachial plexus birth injury (5 of 28), Ollier disease (2 of 28), congenital radial head dislocation (2 of 28), and others (2 of 28). RESULTS: By 4 months (range, 2-10 months) after surgery, 21 of 28 forearms had united. Median resting postoperative forearm rotation was 10° pronation (range, neutral to 25° pronation). Before surgery, pain was present in 23 of 28 forearms. At the latest follow-up, pain was present in 5 of 28 forearms. In three of the 5 forearms with residual pain, this was attributed to ulnohumeral degenerative changes that existed prior to SBFR. Following SBFR, elbow flexion-extension range was maintained. In the subgroup with MHEs, radial articular angle was maintained (median, 37°-30°) and carpal slip percentage improved significantly (median, 40%-12%). Complications occurred in 8 forearms: 3 cases of nonunion in older patients (age, 30, 20, and 14 years), 2 cases of traumatic juxtaimplant fractures following successful union, 1 case of infection, 1 case of compartment syndrome, and 1 case of persistent radiocapitellar impingement. All complications were successfully treated. When stratified by age, none of the patients in the younger group (16 forearms, age < 12 years) had nonunions or pain at latest follow-up. CONCLUSIONS: The SBFR is an old, but generally reliable, option as a single-stage salvage procedure for a number of recalcitrant pediatric forearm pathologies. Success rate may be higher in younger patients. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Congenital Pseudarthrosis of the Fibula: Controlling Ankle Valgus in a Heterogenous Condition.

BACKGROUND: Congenital pseudarthrosis of the fibula (CPF) is a rare disorder characterized by a deficiency in the continuity of the fibula and can lead to progressive ankle valgus malalignment. An existing classification system for CPF is imperfect and may contribute to heterogeneity in reporting and discrepancy of outcomes in the literature. METHODS: Fifteen patients with CPF treated at our institution between 1995 and 2017 were retrospectively identified. Only patients with dysplasia leading to spontaneous fracture or pseudarthrosis were included in this series. The median age at presentation was 2.5 years (range: 3 mo to 13.4 y). The median duration of follow-up from the initial presentation was 11.8 years (range: 2.0 to 24 y). Chart review and serial radiographs were analyzed to assess natural history and outcomes following surgery. RESULTS: The coexistence of tibial dysplasia in CPF is very common. Patients were classified into 3 groups based on the degree of tibial involvement-group 1: no evidence of tibial dysplasia, group 2: mild tibial dysplasia, and group 3: significant tibial dysplasia. Age at presentation and age at which fibular fracture occurred were progressively younger with a greater degree of tibial involvement (P<0.05). In the absence of surgical intervention, group 1 patients did not undergo progressive ankle valgus (defined as the valgus change in tibiotalar angle by ≥4 degrees), whereas all patients in groups 2 and 3 did (P<0.001). Fibular osteosynthesis was performed in 6 patients, with union seen only in group 1 patients. Ten patients underwent distal tibiofibular fusion, with no cases of nonunion seen. Distal tibiofibular fusion with or without medial distal tibial hemiepiphysiodesis halted the progression of ankle valgus in 8 of the 10 patients. Further progression of ankle valgus occurred only in patients who did not undergo concurrent medial distal tibial hemiepiphysiodesis and with considerable wedging of the distal tibial epiphysis at the time of fusion. CONCLUSIONS: Tibial dysplasia and CPF are intimately related. Grouping patients on this basis may help guide natural history and treatment and may explain discrepancies in findings in the literature. Fibular osteosynthesis, distal tibiofibular fusion, and medial distal tibial hemiepiphysiodesis may all have an important role in the treatment of CPF. LEVEL OF EVIDENCE: Level IV-case series.

Congenital pseudarthrosis of the clavicle: surgical decision making and outcomes.

BACKGROUND: Congenital pseudarthrosis of the clavicle (CPC) is a rare entity in which the primary ossification center of the clavicle fails to coalesce. The natural history of CPC is unknown, and there is controversy regarding surgical vs. conservative treatment. METHODS: A retrospective review of 47 pediatric patients treated for CPC was performed. The Quick Disabilities of the Arm and Shoulder (QuickDASH) survey and the Patient Reported Outcomes Measurement Information System (PROMIS) upper extremity domain were used to assess overall patient satisfaction, function, and quality of life after treatment. RESULTS: Twenty-four of 47 (51%) patients underwent surgical treatment. Of these, 9 patients (38%, 9/24) underwent surgery at <18 months of age using suture fixation alone, whereas the older 15 surgical patients (15/24, 62%) were treated with plate fixation. The younger surgical cohort had a nonunion rate of 43% (3/7) compared with 13% (2/15) in the older cohort. All surgical patients had resolution of preoperative symptoms. Eleven (11/24, 46%) surgical subjects responded to the follow-up survey. Upper extremity function normalized according to the QuickDASH survey (score of 0 for all subjects). The median PROMIS upper extremity domain score was 55, which was also in the normal range. CONCLUSIONS: This series of CPC patients improves our understanding of treatment options and outcomes of surgical treatment. All surgical patients had resolution of preoperative symptoms. Patients treated surgically with stable fixation at an older age had higher rates of union than those treated in infancy with suture fixation. Patient-reported outcomes were favorable overall.

Management of Congenital Pseudoarthrosis of the Tibia and Fibula.

PURPOSE OF REVIEW: Congenital pseudoarthrosis of the tibia and fibula are rare conditions that share common treatment strategies. The purpose of this review is to provide an overview of the recent developments in treatments for both conditions. RECENT FINDINGS: Recent literature has focused on the use of BMP and on gait analysis as a tool for measuring long-term functional outcomes. Recent study has indicated rhBMP-2 may shorten the time to initial healing of pseudoarthroses, but not guarantee bony union. Children with initial fractures before the age of four have been shown to have long-term gait outcomes that may be ultimately comparable to children with prostheses. Both congenital pseudoarthrosis of the tibia and fibula are challenging conditions to treat, which require comprehensive approaches to account for both the biological and mechanical components of the conditions.

Cell-matrix interaction during strain-dependent remodelling of simulated collagen networks.

The importance of tissue remodelling is widely accepted, but the mechanism by which the remodelling process occurs remains poorly understood. At the tissue scale, the concept of tensional homeostasis, in which there exists a target stress for a cell and remodelling functions to move the cell stress towards that target, is an important foundation for much theoretical work. We present here a theoretical model of a cell in parallel with a network to study what factors of the remodelling process help the cell move towards mechanical stability. The cell-network system was deformed and kept at constant stress. Remodelling was modelled by simulating strain-dependent degradation of collagen fibres and four different cases of collagen addition. The model did not lead to complete tensional homeostasis in the range of conditions studied, but it showed how different expressions for deposition and removal of collagen in a fibre network can interact to modulate the cell's ability to shield itself from an imposed stress by remodelling the surroundings. This study also showed how delicate the balance between deposition and removal rates is and how sensitive the remodelling process is to small changes in the remodelling rules.

Catastrophic failure of a low profile metal-backed glenoid component after total shoulder arthroplasty.

CONTEXT: The longevity of the glenoid component in total shoulder arthroplasty (TSA) continues to be problematic. All polyethylene glenoid components have been most widely used, but loosening rates with time and the need for revision has resulted in high-profile metal-backed components with the potential for a more stable prosthesis bone interface and liner exchange. High revision rates in the high profile metal backed designs led us to evaluate a low profile metal backed component. AIMS: To examine the rate and mode of failure of a TSA in a single surgeon consecutive series that has been identified by the Australian National Joint Replacement Registry to have a higher than anticipated rate of revision. MATERIALS AND METHODS: This is a single surgeon retrospective consecutive series of 51 arthroplasties undertaken in 50 patients (18 males and 32 females) with an average age of 70.4 ears (range 51-90) and mean follow-up of 5.5 years (range 3.7-8.1). RESULTS: We observed a very high (29%) rate of revision of the metal-backed glenoid components in this series. The primary mode of failure was glenoid baseplate nonintegration which with a well-fixed central cage screw led to bone resorption and implant breakage or disassembly. CONCLUSION: Analysis of the mode of failure of implants identified by robust registries is essential for the development of new prostheses and the pursuit of prosthesis longevity. This low profile metal backed prosthesis has been withdrawn, but without a published mechanism of failure. We feel that any prosthesis withdrawal should be accompanied by appropriate published mechanisms to prevent future component design errors based on similar design problems.

Healthcare-associated infection and hospital readmission.

OBJECTIVE: Hospital readmissions are a current target of initiatives to reduce healthcare costs. This study quantified the association between having a clinical culture positive for 1 of 3 prevalent hospital-associated organisms and time to hospital readmission. DESIGN: Retrospective cohort study. PATIENTS AND SETTING: Adults admitted to an academic, tertiary care referral center from January 1, 2001, through December 31, 2008. METHODS: The primary exposure of interest was a clinical culture positive for methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), or Clostridium difficile obtained more than 48 hours after hospital admission during the index hospital stay. The primary outcome of interest was time to readmission to the index facility. Multivariable Cox proportional hazards models were used to model the adjusted association between positive clinical culture result and time to readmission and to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: Among 136,513 index admissions, the prevalence of hospital-associated positive clinical culture result for 1 of the 3 organisms of interest was 3%, and 35% of patients were readmitted to the index facility within 1 year after discharge. Patients with a positive clinical culture obtained more than 48 hours after hospital admission had an increased hazard of readmission (HR, 1.40; 95% CI, 1.33-1.46) after adjusting for age, sex, index admission length of stay, intensive care unit stay, Charlson comorbidity index, and year of hospital admission. CONCLUSIONS: Patients with healthcare-associated infections may be at increased risk of hospital readmission. These findings may be used to impact health outcomes after discharge from the hospital and to encourage better infection prevention efforts.