Side-to-side nerve bridges reduce muscle atrophy after peripheral nerve injury in a rodent model

Background

Peripheral nerve injury can result in muscle atrophy and long-term disability. We hypothesize that creating a side-to-side bridge to link an injured nerve with a healthy nerve will reduce muscle atrophy and improve muscle function.

Methods

Sprague-Dawley rats were divided into four groups (n = 7 per group). Group 1: transection only—a 10-mm gap was created in the proximal tibial nerve; group 2: transected plus repaired—the transected tibial nerve was repaired; group 3: transected plus repaired plus nerve bridge—transected nerve repaired with a distal nerve bridge between the tibial and peroneal nerves via epineurial windows; and group 4: transected plus nerve bridge—transected tibial nerve left unrepaired and distal bridge added. Gait was assessed every 2 wk. At 90 d the following measures were determined: gastrocnemius mass, muscle and nerve nuclear density, and axonal infiltration into the nerve bridge.

Results

Groups 3 and 4 had greater improvements in walking track recovery than groups 1 and 2. Group 3's gastrocnemius muscles exhibited the least amount of atrophy. Groups 1, 2, and 4 exhibited greater histologic appearance of muscle breakdown compared with group 3 and control muscle. Finally, most bridges in groups 3 and 4 had neuronal sprouting via the epineurial windows.

Conclusions

Our study demonstrated reduced muscle atrophy with a side-to-side nerve bridge in the setting of peripheral nerve injury. These results support the application of novel side-to-side bridges in combination with traditional end-to-end neurorrhaphy to preserve muscle viability after peripheral nerve injuries.     

Ligament reconstruction/advancement for management of instability due to ligament insufficiency during total knee arthroplasty: a viable alternative to constrained implant

Background

We aimed to assess the results of ligament reconstruction/advancement for the management of ligament insufficiency during total knee arthroplasty.

Method

We retrospectively reviewed the results of ligament reconstruction/advancement for management of instability due to ligament insufficiency during total knee arthroplasty (TKA). Between January 2001 and January 2008 collateral ligament reconstruction/advancement was done in 15 patients. Wherever ligament advancement was not possible (mid-substance tear) ligament reconstruction was done using the hamstring tendon. Knee society scores were calculated and Kaplan–Meier survival analysis was done.

Results

Average follow-up was 6.2 years. No patient developed instability until the last follow-up, except one patient who required revision due to instability at six years after primary surgery.

Conclusion

We concluded from this study that ligament reconstruction/advancement during TKA is a viable option to address instability due to ligament insufficiency.     

Correlation of oxidation–reduction potential with hormones,semen parameters and testicular volume

Seminal oxidative stress (OS) is a major cause of male factor infertility and can be measured as oxidation–reduction potential (ORP). Studies showed significant negative relationships of ORP with sperm count, motility or DNA integrity. Since these parameters are also positively or negatively associated with reproductive hormones follicle‐stimulating hormone (FSH), luteinising hormone (LH), testosterone, testicular volume and the occurrence of varicocele, it is important to understand the mechanistic relationship between ORP and hormonal and/or testicular parameters. Therefore, we studied the relationship between ORP levels, standard hormone profiles and testicular volume in infertile men with and without varicocele. Results show a highly significant negative relationship of ORP with testicular volume and significantly positive correlations with FSH and LH. Yet, when adding varicocele as covariate, the relationship with FSH/LH became nonsignificant. Contrary, the presence of varicocele had only a contributing influence on the association of ORP with the testis volume. No association was found with estradiol. We propose that since OS causes degeneration of Sertoli cell with testicular shrinkage, such negative effect would result in a negative feedback on the hypothalamus with less inhibin secretion. This may result in increased secretion of LH and FSH. Thus, systemic and/or local OS may be responsible for smaller testis volumes.     

Double floating injuries in lower limb

Die laparoskopische Chirurgie hat sich in den letzten Jahren zunehmend verbreitet und sich für einige Indikationen sogar zum Goldstandard entwickelt. Auch für kolorektale Eingriffe wird der laparoskopische Zugang zunehmend benutzt, wobei jedoch im Hinblick auf die Sicherheit bei onkologischen Koloneingriffen noch keine abschließende Beurteilung möglich ist. Die operative Therapie der Rektumkarzinome, die durch die Einführung der totalen mesorektalen Exzision (TME) zusätzliche Vorteile hinsichtlich der Rate an Lokalrezidiven erfahren hat, war bislang nicht Gegenstand der laparoskopischen Operationstechnik, da die angenommene Lernkurve und die fragliche onkologische Sicherheit einen derartigen Therapieansatz nicht zuließen.In der hier diskutierten Studie wurde bei Patienten mit Rektumkarzinom die Operation mit TME laparoskopisch durchgeführt. Es konnte gezeigt werden, dass sowohl die onkologischen Ergebnisse (Rezidivrate und Überleben) als auch das kurzfristige Outcome (Mortalität und Morbidität) mit den Ergebnissen der konventionell durchgeführten Operation vergleichbar sind. Ferner bleiben für die Patienten die von anderen laparoskopischen Operationen bekannten Vorteile (Schmerzreduktion, frühe Mobilisation, frühe Darmpassage) erhalten. Die Weiterentwicklung der laparoskopischen Technik könnte hier noch weitere Vorteile bringen, sofern die Konversionsrate zum konventionellen Verfahren durch adäquate Patientenselektion begrenzt werden kann.     

Pumping iron: revisiting risks, benefits and strategies in treatment of iron deficiency in end-stage renal disease

Iron deficiency is a common cause of anemia in patients with end stage renal disease (ESRD). Intravenous iron administration, especially in those requiring treatment with erythropoiesis stimulating agents (ESA) is an essential component of the management of anemia in ESRD patients. Iron improves hemoglobin, reduces ESA dose requirement and also has nonerythropoietic effects including improvement in physical performance, cognition and amelioration of restless leg syndrome. However, iron can promote oxidative stress, cause endothelial dysfunction, inflammation and tissue injury, and has a potential to cause progression of both CKD and cardiovascular disease. In this review, we discuss the benefits and risks associated with i.v. iron and the practical aspects of iron administration that can minimize the complications related to iron therapy in ESRD.     

Adolescent varicocele: association with somatometric parameters

INTRODUCTION: The developmental changes that occur as a result of puberty have been hypothesized to be important causes of varicocele. Various somatometric parameters were known to affect the occurrence of varicocele during the growth period. We conducted this study in order to examine these relationships and to determine the incidence of varicocele in adolescent males. PATIENTS AND METHODS: We evaluated 1,200 healthy males aged 0-19 years for varicocele and correlated it with the following somatometric parameters: age, height, body mass index (BMI), pubic hair distribution, penile length and testicular volume. RESULTS: Adolescent varicocele was found in 5.6% of the participants. The 13- to 19-year age-group had the highest incidence of varicocele (10.5%). Logistic regression analysis showed that the incidence was positively correlated with age, height and penile length (odds ratio 1.61, 1.04 and 1.37, respectively) and negatively correlated with left testicular volume, BMI and pubic hair distribution (odds ratio 0.87, 0.87 and 0.47, respectively). CONCLUSION: Varicocele was more prevalent in tall boys with a lower BMI, who had quickly progressed through puberty. Our observations suggest that varicocele is associated with various somatometric parameters.     

Implantation of parathyroid carcinoma along fine needle aspiration track

Introduction Fine needle aspiration cytology is not a commonly employed diagnostic modality in the diagnosis of parathyroid tumors.Case report A 28 year old lady being followed-up for 5 years after en bloc resection of a parathyroid carcinoma presented with a nodule in the lower neck, away from the parathyroidectomy scar. The 1 cm isolated nodule was located in the muscular and subcutaneous plane and corresponded to the needle track of FNA performed on a neck nodule before the parathyroidectomy. On evaluation, she had mild hypercalcemia and high normal serum parathyroid hormone levels. FNAC and histology including immunohistochemistry for Chromogranin A after local excision of the nodule confirmed the nodule to be a recurrent parathyroid carcinoma along the needle track.Discussion To the best of the authors’ knowledge, this is only the second case of needle track implantation after FNA in parathyroid carcinoma reported to date. This case highlights the risk of engraftment of parathyroid tissue after FNA and cautions against the use of FNA as a preoperative diagnostic modality for the evaluation of parathyroid lesions.Drs. Agarwal and Dhingra have contributed equally, as joint first authors.     

Teriparatide Followed by Denosumab in Premenopausal Idiopathic Osteoporosis: Bone Microstructure and Strength by HR-pQCT

Premenopausal women with idiopathic osteoporosis (PreMenIOP) have marked deficits in skeletal microstructure. We have reported that sequential treatment with teriparatide and denosumab improves central skeletal bone mineral density (BMD) by dual-energy X-ray absorptiometry and central QCT in PreMenIOP. We conducted preplanned analyses of high-resolution peripheral quantitative computed tomography (HR-pQCT) scans from teriparatide and denosumab extension studies to measure effects on volumetric BMD (vBMD), microarchitecture, and estimated strength at the distal radius and tibia. Of 41 women enrolled in the parent teriparatide study (20 mcg daily), 34 enrolled in the HR-pQCT study. HR-pQCT participants initially received teriparatide (N = 24) or placebo (N = 10) for 6 months; all then received teriparatide for 24 months. After teriparatide, 26 enrolled in the phase 2B denosumab extension (60 mg q6M) for 24 months. Primary outcomes were percentage change in vBMD, microstructure, and stiffness after teriparatide and after denosumab. Changes after sequential teriparatide and denosumab were secondary outcomes. After teriparatide, significant improvements were seen in tibial trabecular number (3.3%, p = 0.01), cortical area and thickness (both 2.7%, p < 0.001), and radial trabecular microarchitecture (number: 6.8%, thickness: 2.2%, separation: −5.1%, all p < 0.02). Despite increases in cortical porosity and decreases in cortical density, whole-bone stiffness and failure load increased at both sites. After denosumab, increases in total (3.5%, p < 0.001 and 3.3%, p = 0.02) and cortical vBMD (1.7% and 3.2%; both p < 0.01), and failure load (1.1% and 3.6%; both p < 0.05) were seen at tibia and radius, respectively. Trabecular density (3.5%, p < 0.001) and number (2.4%, p = 0.03) increased at the tibia, while thickness (3.0%, p = 0.02) increased at the radius. After 48 months of sequential treatment, significant increases in total vBMD (tibia: p < 0.001; radius: p = 0.01), trabecular microstructure (p < 0.05), cortical thickness (tibia: p < 0.001; radius: p = 0.02), and whole bone strength (p < 0.02) were seen at both sites. Significant increases in total vBMD and bone strength parameters after sequential treatment with teriparatide followed by denosumab support the use of this regimen in PreMenIOP. © 2022 American Society for Bone and Mineral Research (ASBMR).