Further evidence for mitochondrial dysfunction in progressive supranuclear palsy

Recent data from our laboratory have identified a role for mitochondrial dysfunction in the pathogenesis of progressive supranuclear palsy (PSP). To extend this finding, we measured key parameters of mitochondrial function in platelet-derived cytoplasmic hybrid (cybrid) cell lines expressing mitochondrial genes from patients with PSP. We observed significant decreases in aconitase activity, cellular ATP levels, and oxygen consumption in PSP cybrids as compared to control cybrids, further suggesting a contributory role of impaired mitochondrial energy metabolism in PSP, possibly due to genetic abnormalities of mitochondrial DNA.

Predicting Risk of Recurrent Patellofemoral Instability With Measurements of Extensor Mechanism Containment

BACKGROUND

Identifying risk factors for recurrent patellar dislocation after a primary dislocation may help guide initial treatment. Magnetic resonance imaging (MRI) measurements relating the alignment of the extensor mechanism to trochlear morphology have been shown to distinguish patients with dislocations from controls, but their usefulness in predicting the risk of a second dislocation is not known.

PURPOSE

To identify the association of novel MRI measures of patellar containment with recurrent instability in pediatric patients presenting with a first-time patellar dislocation.

STUDY DESIGN

Cohort study (Prognosis); Level of evidence, 3.

METHODS

The study was conducted at a tertiary care children's hospital (2005-2014) on patients (age, 8-19 years) with a first-time patellar dislocation. MRI measurements were made by 2 independent raters. Interobserver reliability was assessed for all measurements via an intraclass correlation coefficient (ICC). Only measurements with an ICC >0.8 were included. Univariable and multivariable logistic regression analyses were used to evaluate variables associated with recurrence.

RESULTS

A total of 165 patients with a median age of 14 years and a slight (57.6%) female predominance was identified. The median follow-up length of the whole cohort was 12.2 months (interquartile range, 1.6-37.1 months). Subsequent instability was documented in 98 patients (59.4%). MRI measurements with excellent correlation (ICC > 0.8) were the tibial tubercle to trochlear groove distance (TT-TG), the tangential axial width of the patella, the tangential axial trochlear width, the axial width of the patellar tendon beyond the lateral trochlear ridge (LTR), and the tibial tubercle to LTR distance. In univariate analysis, all mentioned MRI measurements had significant association with recurrent instability. However, after both backward and forward stepwise regression analyses, the tibial tubercle to LTR distance was the only independent predictor of recurrent instability (P = .003 in both). Patients with a tibial tubercle to LTR distance value greater than -1 mm had a significantly higher rate of recurrent patellar dislocation (72%).

CONCLUSION

Of numerous axial view MRI parameters, only the tibial tubercle to LTR distance demonstrated a statistically significant association with recurrent patellar instability upon multivariable logistic regression analysis during short-term follow-up of a pediatric population presenting with initial lateral patellar dislocation. Interobserver correlation of the tibial tubercle to LTR distance was good (ICC > 0.8) and similar to that of TT-TG.

Protocadherin 10 alters γ oscillations, amino acid levels, and their coupling; baclofen partially restores these oscillatory deficits

Approximately one in 45 children have been diagnosed with Autism Spectrum Disorder (ASD), which is characterized by social/communication impairments. Recent studies have linked a subset of familial ASD to mutations in the Protocadherin 10 (Pcdh10) gene. Additionally, Pcdh10's expression pattern, as well as its known role within protein networks, implicates the gene in ASD. Subsequently, the neurobiology of mice heterozygous for Pcdh10 (Pcdh10^+/-) has been investigated as a proxy for ASD. Male Pcdh10^+/- mice have demonstrated sex-specific deficits in social behavior, recapitulating the gender bias observed in ASD. Furthermore, in vitro slice preparations of these Pcdh10^+/- mice demonstrate selective decreases to high frequency electrophysiological responses, mimicking clinical observations. The direct in vivo ramifications of such decreased in vitro high frequency responses are unclear. As such, Pcdh10^+/- mice and their wild-type (WT) littermates underwent in vivo electrocorticography (ECoG), as well as ex vivo amino acid concentration quantification using High Performance Liquid Chromatography (HPLC). Similar to the previously observed reductions to in vitro high frequency electrophysiological responses in Pcdh10^+/- mice, male Pcdh10^+/- mice exhibited reduced gamma-band (30-80Hz), but not lower frequency (10 and 20Hz), auditory steady state responses (ASSR). In addition, male Pcdh10^+/- mice exhibited decreased signal-to-noise-ratio (SNR) for high gamma-band (60-100Hz) activity. These gamma-band perturbations for both ASSR and SNR were not observed in females. Administration of a GABA_B agonist remediated these electrophysiological alterations among male Pcdh10^+/-mice. Pcdh10^+/- mice demonstrated increased concentrations of GABA and glutamine. Of note, a correlation of auditory gamma-band responses with underlying GABA concentrations was observed in WT mice. This correlation was not present in Pcdh10^+/- mice. This study demonstrates the role of Pcdh10 in the regulation of excitatory-inhibitory balance as a function of GABA in ASD.

Arthroscopic debridement for acute hemorrhagic subacromial bursitis following COVID-19 vaccine administration: A case report

The rapid rollout of vaccinations in response to the COVID-19 pandemic has led to their widespread distribution and administration throughout the world. The benefit of these vaccinations in preventing the spread of the disease and diminishing symptoms in patients who contract COVID-19 has been fervently studied and reported. While vaccinations remain an effective and generally safe method of limiting disease transmission and virus-related mortality, vaccine administration is not completely without risk. Shoulder injuries related to vaccine administration (SIRVA) have been described with previously available vaccines but have yet to be widely reported in the COVID-19 vaccination population. We present a case report of a young, high-functioning patient who presented with acute subacromial bursitis after COVID-19 vaccine administration due to improper vaccination technique. The patient was treated with arthroscopic shoulder surgery and had near immediate relief of shoulder symptoms.

Outcomes of Distal Radius Fractures in Solid Organ Transplant Recipients

PURPOSE

Distal radius fractures (DRFs) are one of the most common conditions that musculoskeletal providers treat. As the frequency of solid organ transplants (SOT) increases, these providers are often called upon to manage DRFs in these patients. These patients are at increased risk for osteopenia and osteoporosis, given the altered bone metabolism after SOT and frequent use of glucocorticoid and immunosuppressive medications. This study aimed to examine both surgical and nonsurgical treatment outcomes of DRFs in the SOT population and the prevalence of decreased bone mineral density.

METHODS

A retrospective review of patients treated at a single institution who had previously undergone SOT and subsequently sustained DRF between 2013 and 2022 was completed. Patients were excluded for incomplete documentation and treatment initiation at an outside institution. Demographic variables, clinical outcomes, organ transplant, steroid use, and second metacarpal cortical percentage were collected for both groups. A telephone survey with the QuickDASH questionnaire was conducted for all available patients.

RESULTS

A total of 34 DRFs in 33 patients were included in the analysis. Of these, 15 fractures in 14 patients underwent surgical intervention, and 19 fractures in 19 patients were managed nonsurgically. The following three adverse events were observed in the patients managed operatively: hardware failure, postoperative carpal tunnel syndrome, and tendon irritation. No reported treatment complications were recorded in the patients managed nonsurgically. Of the 33 included patients, 32 had radiographic evidence of decreased bone mineral density and five were receiving treatment for osteoporosis.

CONCLUSIONS

Management of DRFs in SOT patients is challenging, given their increased medical complexity. Decreased bone mineral density was nearly universal and undertreated in this patient population. Most of these patients in both groups had good or excellent functional outcomes with both surgical and nonsurgical management. Additionally, surgery was well tolerated with no reported anesthesia complications, wound-healing issues, or infections.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

A Case Report of Bilateral Navicular Osteonecrosis Successfully Treated With Medial Femoral Condyle Vascularized Autografts: A Case Report

CASE

A 17-year-old boy with a history of chronic bilateral navicular osteonecrosis with fragmentation was treated with 6-month staged bilateral open reduction and internal fixation of tarsal navicular with debridement of the necrotic bone and ipsilateral medial femoral condyle vascularized bone grafting.

CONCLUSION

The patient progressed to full painless weight-bearing on each extremity by 4 months postoperatively with osseous union of both chronic fracture sites and incorporation of vascularized bone grafts. Patient-Reported Outcomes Measurement Information System (PROMIS) scores were improved from preoperative levels at 6 months from each operation. This patient's atypical presentation of a rare disease was successfully treated with the utilization of vascularized bone grafting to salvage the tarsal navicular and preserve the talonavicular joint, enabling return of function and avoidance of early arthrodesis procedure.

Management and Outcomes of Femur Fractures in Patients with Duchenne Muscular Dystrophy

Background: Duchenne muscular dystrophy (DMD) is a severe, progressive X-linked recessive neuromuscular disorder characterized by muscle weakness and atrophy. Additionally, patients with DMD have significant reductions in bone mineral density compared to age-matched controls, which is exacerbated by concomitant steroid use. These findings dramatically increase fracture risk, which may irreparably decrease functional status. The aim of this case series is to examine outcomes of operative versus nonoperative management of femur fractures in this patient population.Methods: An IRB-approved retrospective chart review was completed for patients with DMD treated at a single institution for a femur fracture between 2013-2022. Patients were excluded for incomplete documentation, treatment initiation at an outside hospital, or diagnosis of a different muscular dystrophy. Demographic variables, treatment information, functional status, and adverse events were collected for each patient. Descriptive statistics were used to summarize demographic and outcome variables.Results: A total of 10 patients with 11 femur fractures were included for analysis. All patients were male with an average age of 12.7 years and clinical follow-up of 286 days. Five fractures in five patients underwent operative fixation (Group A), and six fractures in five patients underwent nonoperative management (Group B). In Group A, three patients were short-distance ambulators prior to injury, and all patients regained a similar functional status postoperatively. All three patients were treated with a locked intramedullary nail. One patient in Group B was a short-distance ambulator prior to injury; the remainder were nonambulatory. All patients in Group B were primary wheelchair users at final follow-up. There were no adverse events as a result of treatment in either group.Conclusion: Nonoperative management with cast immobilization remains an acceptable option for nonambulatory patients and those with minimally displaced fractures not amenable to surgical intervention. Surgical intervention is recommended for higher-functioning patients with the goal of restoring ambulatory status. Regardless of treatment modality, patients should receive aggressive physical therapy directed at early weight-bearing, range of motion, and mobilization to preserve strength, muscle mass, and mobility.Level of Evidence: Level IV case series.

Key Concepts

•Management of femur fractures in Duchenne muscular dystrophy should account for fracture morphology as well as patient functional status.•Surgical management is safe and effective in promoting fracture union and preserving functional status.•Nonoperative management is preferred in nonambulatory patients and for minimally displaced fractures.

The Scratch-Collapse Test: Are Electrodiagnostic Changes Measurable?

INTRODUCTION

Carpal tunnel syndrome is commonly managed by hand and upper extremity surgeons. Though electrodiagnostics are considered the gold standard diagnosis, the scratch collapse test (SCT) was introduced to address uncertainty, despite remains controversial. To address this, we sought to identify if the SCT can correlate with EDS studies if the SCT can identify actual changes in measures of nerves.

METHODS

We reviewed patients who underwent electrodiagnostic studies (EDX) and SCT for carpal tunnel syndrome (CTS). Demographic data as well as sensorimotor amplitudes, latencies, and velocities on nerve conduction and electromyography were collected. Analogous values based on SCT findings were analyzed for statistical significance.

RESULTS

Three hundred fifty patients with CTS were included. Sensory and motor velocities and amplitudes were significantly lower in patients with a positive SCT. Motor values were independent of age, though younger patients had larger measured changes. Obese patients did not show any motor EDX changes with the scratch collapse test, though thinner patients did. All changes were seen in nerve conduction only.

CONCLUSIONS

Carpal tunnel can be a difficult problem to diagnose as one study does not singularly determine the condition. The SCT was introduced to facilitate easier diagnosis. We demonstrate that the SCT correlates with changes on nerve conduction studies, especially in relation to decreased amplitudes and velocities, suggesting that it does identify changes in nerve with compression, specifically axonal, and myelin damage. These findings support the use of the SCT maneuver to evaluate and diagnose in appropriate patients.

Early Thumb Carpometacarpal Subluxation Stabilized with a Mini TightRope: A Report of Two Cases

Two patients with thumb carpometacarpal instability were stabilized using a suture suspension device. Both patients had symptomatic thumb carpometacarpal instability in the setting of clinical hyperlaxity without known connective tissue disorder that was recalcitrant to nonsurgical modalities. Both patients had significant, lasting improvement in their pain and function with excellent radiographic outcomes. Suture suspension as a treatment for thumb carpometacarpal instability with an intact trapezium is an effective alternative to ligamentous reconstruction that avoids donor site morbidity and may have added benefit in patients with underlying ligamentous laxity.

Approach to the Treatment of Expansile Metacarpal Aneurysmal Bone Cysts: A Report of Two Cases

The two cases presented demonstrate the management of aneurysmal bone cysts of the metacarpal, which destroyed the normal bone architecture. Treatment of both cases included wide resection and metacarpal reconstruction with an intercalary fibular allograft. Denosumab use contrasts these two cases and is helpful in reestablishment of a cortical rim for fixation in the absence of a 1-cm margin proximally or distally to preserve the native carpometacarpal and metacarpophalangeal joints. Surgical resection and allograft reconstruction is a viable treatment for expansile metacarpal aneurysmal bone cysts, and neoadjuvant denosumab has utility in creating an ossified margin for fixation.

Efficacy of methylprednisolone administration in a case of continuous abnormal muscle activity syndrome

We report a 20-year-old woman with continuous abnormal muscle activity syndrome in which pharmacological blockade of different sites of the motor unit demonstrates a peripheral nerve origin for the abnormal muscle activity. The case showed no markers of autoimmune disease. A rapid recovery after high dose i.v. methylprednisolone was observed supporting the hypothesis of an autoimmune pathogenesis.

Percutaneous Screw Fixation for the Management of Delayed Unions in Pediatric Lateral Humeral Condylar Fractures

BACKGROUND

The use of in situ screw fixation for the treatment of pediatric lateral humeral condyle (LCH) delayed unions has recently been reported. While attractive, the currently available literature consists of small retrospective studies with mixed results. As such, the present study aims to describe the outcome of a group of children with delayed unions of LCH fractures treated with in situ fixation using a single, percutaneously placed cannulated screw in compression.

METHODS

A retrospective review of all pediatric patients (below 18 y) with lateral condyle fractures of the humerus treated surgically for delayed union between 2013 and 2023 at a single, tertiary referral center was completed. Clinical and radiologic variables related to the initial injury and delayed union were abstracted from the medical record, as were surgical variables. Radiographs were evaluated for union postoperatively; time to union was determined by the senior authors. Descriptive statistics were used to summarize demographic and outcome variables.

RESULTS

A total of 12 consecutive patients met the inclusion criteria. The mean age at the time of initial injury was 5.6 years; subjects were followed for a mean of 3.0 years following initial presentation. All were treated with a single, percutaneously placed screw in compression at a mean of 10.5 months after the original injury. Radiographic union was achieved in 11 (91.7%) patients. At the latest follow-up, all patients were pain free and demonstrated a functional arc of motion without evidence of avascular necrosis. A total of 2 patients required revision for loss of fixation. In one patient, a persistent lucent line was observed, and 1 patient was found to have a cubitus valgus deformity, both of which were not clinically relevant.

CONCLUSIONS

Our results suggest that with the use of proper technique (a 4.5 cannulated screw inserted through the metaphyseal portion of the lateral condyle fragment, engaging the most medial/distal aspect of the humeral shaft), radiographic union and clinical healing can be achieved in the majority of patients. Percutaneous screw fixation should be considered as an option for cases of noninfected pediatric lateral condyle delayed unions.

LEVEL OF EVIDENCE

Level IV-evidence therapeutic studies.

[Neuroradiological findings in 2 cases of Wilson disease with neurological involvement]

Wilson disease is an inborn error of copper metabolism that has neurological and hepatic manifestations. We report a 13 years old girl and a 12 years old boy with Wilson disease. In both patient, brain computed tomography and magnetic resonance imaging showed marked involvement of basal ganglia and other deep gray nuclei. Considering that this is a treatable disease, it should be included in the differential diagnosis of the so called "striatal necrosis of childhood".

The Utility of Routine Radiographic Monitoring in Pediatric Osteoarticular Infections

BACKGROUND

Pediatric musculoskeletal (MSK) infections broadly include isolated osteomyelitis (OM), septic arthritis (SA), and combined infections (OM+SA). These diagnoses are often monitored with serum inflammatory markers and serial radiographs to monitor treatment response and development of negative sequelae, despite limited data supporting these practices. The purpose of this study is to evaluate the utility of obtaining serial radiographic follow-up for pediatric osteoarticular infections.

METHODS

An institutional review board-approved retrospective review was completed. Children 18 years and below admitted to a single institution with a culture/biopsy-proven diagnosis of OM, SA, or OM+SA. All postdischarge radiographs were reviewed and retrospectively categorized as either routine (scheduled) or reactive. Routine radiographs were obtained regardless of clinical presentation. Reactive radiographs were obtained in patients presenting with the sign of an altered clinical course. Negative sequelae, defined as growth arrest/disturbance, pathologic fracture, recurrent MSK infection, and underlying neoplastic process, were recorded and tracked. Descriptive statistics were used to summarize demographic and outcome variables. Number needed to screen (NNS) was defined as the inverse of the incidence of negative sequelae detected.

RESULTS

A total of 131 patients were included for analysis, with a mean age of 11.9 years (SD: 4.96 y). Ninety (69%) patients were diagnosed and treated for OM, 25 (19%) for SA, and 16 (12%) for combined infections. A total of 329 radiographs were obtained following discharge. Of those obtained, 287 (88%) were routine, resulting in the detection of 2 (0.7%) negative sequelae and a resultant NNS of 143 radiographs (95% confidence interval: 36-573). The remaining 39 were reactive radiographs, resulting in the detection of 2 (5.1%) negative sequelae with an NNS of 20 radiographs (95% confidence interval: 5-78).

CONCLUSIONS

While radiographs remain a widely utilized tool to screen for the development of negative sequelae in pediatric osteoarticular infections, they rarely alter management in the absence of other concerning clinical signs or symptoms such as recurrent fevers, swelling of the extremity, or limb deformity. Moreover, routine radiographic surveillance should be replaced with a reactive radiographic protocol.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.