Interprosthetic and interimplant femoral fractures: is bone strut allograft augmentation with ORIF a validity alternative solution in elderly?

Background: Nowadays orthopedic surgeons have a new challenge to treat the interimplants fractures. Although fixation strategies exist for periprosthetic hip and knee fractures, there is no standard of care regarding the more complex interprosthetic and interimplants fractures. Objective: The aim of our study is targeting the focus on the bone strut grafting to avoid the metal hardware failure and to achieve the bone healing in these injuries. Methods: A prospective case note review of all interprosthetic or interimplants femoral fractures admitted to our trauma center. There were 11 patients (2 males and 9 females) with a mean age over 85 years old. We treated all the patients by ORIF and medial graft strut allograft to reduce the main complication leading to re-operations and morbidity or mortality is the nonunion or delayed union. The criteria to evaluate the patients during the follow-up were: the survival and complication after the surgery; the objective quality of life measured by Activities of Daily Living Score (ADL). The bone healing was measured by X-rays control as the alignment was measured by radiographic UNION SCORE, and postoperative complications. Results: All the patients reduced their ADL. In the most of cases we had a good x-rays reduction. We had not: No nonunion or Not delayed union. All patients died within 2 years from the surgery but not due by surgical complications. Conclusions: According us, the purpose of this surgery is to limit comorbidities and early mortality not to improve optimal restoration of lower limb function.

Treatment of Unstable Elbow Injuries with a Hinged Elbow Fixator: Subjective and Objective Results.

Introduction: Injuries around the elbow pose a challenging problem for orthopaedic surgeons. The complex bony architecture of the joint should be restored and the thin soft tissue envelope needs to be handled with meticulous care. Elbow instability is a complication seen after dislocations and fractures of the elbow and remains a treatment challenge. The purpose of this study was to provide subjective and objective results following the surgical treatment of unstable elbow dislocations with an external hinged fixation technique. Methods: Forty-six consecutive patients with complex trauma of the elbow with instability after ligament reconstruction were enrolled between January 2017 and December 2019. The parameters used to quantify the subjective and objective functional results were the Mayo Elbow Score (MES, objective) and Oxford Elbow Score (OES, subjective), and clinical stability of the elbow joint. We also performed a radiological follow-up of the fractures. Results: The mean MES and OES scores were good at the 12-month follow-up. We had 38 patients with stable joints and 8 patients with minor instability. Using the stress test, we saw a significant difference in the affected joint under varus stress (6.7 ± 1.8 mm) compared to the healthy joint (5.8 ± 1.2 mm) laterally. Furthermore, medially the gap was significantly larger (5.8 ± 0.8 mm, treated elbow) than the contralateral gap under valgus stress (4.3 ± 0.8 mm) (p <0.001). Twenty-one complications occurred in 46 patients (46%): Seven patients had a clinical change of elbow axis: Three valgus (6%), four varus (9%); Superficial wound infection occurred in one case (2%) and ulnar nerve dysfunction in two (4%). The most common medium-term complication was post-traumatic osteoarthritis in eight cases (17%). Heterotopic ossification occurred in five patients (11%) and elbow stiffness in five cases (11%). Conclusion: The use of the hinged elbow external fixator in the treatment of complex elbow trauma is a valid therapeutic adjunct to ligamentous reconstruction showing encouraging results with acceptable complications. How to cite this article: Meccariello L, Caiaffa V, Mader K, et al. Treatment of Unstable Elbow Injuries with a Hinged Elbow Fixator: Subjective and Objective Results. Strategies Trauma Limb Reconstr 2022;17(2):68-73.

Correlations enhance the behavioral readout of neural population activity in association cortex.

Noise correlations (that is, trial-to-trial covariations in neural activity for a given stimulus) limit the stimulus information encoded by neural populations, leading to the widely held prediction that they impair perceptual discrimination behaviors. However, this prediction neglects the effects of correlations on information readout. We studied how correlations affect both encoding and readout of sensory information. We analyzed calcium imaging data from mouse posterior parietal cortex during two perceptual discrimination tasks. Correlations reduced the encoded stimulus information, but, seemingly paradoxically, were higher when mice made correct rather than incorrect choices. Single-trial behavioral choices depended not only on the stimulus information encoded by the whole population, but unexpectedly also on the consistency of information across neurons and time. Because correlations increased information consistency, they enhanced the conversion of sensory information into behavioral choices, overcoming their detrimental information-limiting effects. Thus, correlations in association cortex can benefit task performance even if they decrease sensory information.

The challenge of the surgical treatment of paediatric distal radius/ forearm fracture: K wire vs plate fixation - outcomes assessment.

Aim Distal radius/forearm fractures in adolescent patients remain challenging injuries to treat. Distal radius/forearm bony anatomy is not completely restored with intramedullary K wire fixation. The aim of this study was to compare radiographic and functional outcomes obtained using intramedullary K wire fixation and open reduction and internal fixation in the treatment of distal radius/ forearm fracture. Methods A total of 43 patients who presented with distal radius/ forearm fractures were enrolled and divided into two groups: 23 patients treated with K-wire (IMNK) and 20 patients treated with plate and screws (ORIF). The evaluation criteria were: fracture healing time, objective quality of life measured by the Mayo wrist score (MWS) and quick disabilities of the arm, shoulder and hand score (QuickDash), length time of surgery, complications, sport or play return, forearm visual analogic pain (FVAS), bone healing by radius union scoring system (RUSS). Results In both groups the results obtained were comparable in terms of functional, pain and return to play/sport after the third month after surgery. Bone healing was faster in IMNK than ORIF but without significance (p>0.05). There was less complication in ORIF than IMNK (p<0.05). Conclusion The treatment of adolescent distal radius or forearm fractures remains challenging. One challenge facing the physician is the choice of surgical technique and fixation method, which will be influenced by individual experience and preference. The question of distal radius or forearm fractures in adolescents would be best answered with a prospective randomized study.

Radiographic and functional outcome of complex acetabular fractures: implications of open reduction in spinopelvic balance, gait and quality of life.

Aim To investigate the effects of surgical reduction of complex acetabular fractures on spine balance, postural stability and quality of life. Methods Twenty-six patients with acetabular fractures surgically treated by open reduction and internal fixation were divided into two groups according to the amount of reduction. Group A consisted of 18 patients with satisfactory reduction (≤2 mm), and group B of eight patients with incomplete reduction (>2 mm). Functional outcome was measured with Harris Hip Score (HHS), Oswestry Disability Index (ODI), and Short Form (12) Health Survey (SF12). Radiological parameters were assessed with standing whole spine, pelvis and hip X-rays, including pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), and sagittal vertical axis (SVA). Follow-up intervals were 1, 3, 6 and 12 months and annually thereafter. Gait analysis and baropodometry were performed after 24 months of operation. Results Mean HHS, ODI, and SF-12 was improved during the first postoperative year in both groups. After two years average scores kept improving for group A, but worsened for group B. Mean PI, PT, and SS increased in both groups during the first postoperative year, with further increase after two years only in group B. After two years, 16 (89%) patients in group A and four (50%) in group B had a balanced spine (SVA <50 mm). Gait analysis and baropodometry showed greater imbalance and overload for group B compared to group A. Conclusion In the long term, incomplete reduction of associated acetabular fractures may lead to poor outcome because of secondary spinopelvic imbalance, with posture and gait impairment.

Two-stage bone-and-strut technique in the treatment of septic non-unions in the upper limb.

Aim To report the results of a two-stage reconstruction of septic non-unions of the upper limb using the bone-and-strut technique with a follow-up of more than two years. Methods A total of 19 patients (12 males and seven females; age 27 to 85 years) were included in this cohort study. The evaluation endpoint was set at 24 months. Radiographic union, Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) scores, pain and return to work were assessed. All patients were treated with debridement and antibiotic therapy. At a second stage, the nonunion focus was filled with a cancellous bone allograft. Stability was provided using a locking plate and a bone strut. Results After 24 months, the QuickDASH scores improved from a median of 28 (interquartile range, 13 - 35 points), to a median of 78 (interquartile range, 70 - 89 points). Mean pain scores improved from 8.1 (range, 0.3-10) to 0.6 (range 0-2). Radiographic and clinical union was seen in all patients. The majority of patients returned to work or previous activities when retired. A new neurological deficit, recurrence of infection, or other surgery-related adverse events were not observed. Conclusion The two-stage bone-and-strut technique is a safe and effective technique in the treatment of septic non-unions of the upper limb. The union rate is high, the complication rate is acceptable and return return-to-work is high. Recurrence of infectious sequelae during a follow-up period of at least two years was not seen. The patient-reported outcomes increased significantly.

Effectiveness of teriparatide combined with the Ilizarov technique in septic tibial non-union.

Aim The septic non-union is a common compliance in bone healing due to bone infection. Bone resection, associated with Ilizarov osteo-distraction technique, is commonly used in these cases. The aim of this study was to analyse clinical and radiological results of teriparatide in combination with the Ilizarov technique and to compare this treatment with the standard treatment. Methods Forty adult patients underwent surgery because of type C of the Association for the Study and Application of Methods of Ilizarov (ASAMI) classification non-union were enrolled. The patients were divided in two groups: those treated with Ilizarov technique (Norm group) and those treated with Ilizarov technique combined with teriparatide injection (Teri group). Surgical duration, complication rate, bone healing status, clinical and functional outcomes were assessed according to the A.S.A.M.I. classification in the mean follow-up of 12 months. The subjective quality of life was assessed by the Short Form Survey (SF)-12. Results Teri group showed less time wearing Ilizarov's frame (p <0.05) than the Norm group and a statistical significance in the inter-rater reliability Cohen's k (p>0.05) respect to Norm according the score between the bone healing and clinical outcome results. There was no statistically significant difference between the two groups in other parameters that were assessed. Conclusion A benefit of teriparatide was found as adjuvant in the treatment of septic non-union.

Comparing hand strength and quality life of locking plate versus intramedullary k wire for transverse midshaft metacarpal fractures.

Aim In the scientific literature there are no papers that clarify which method of surgical fixation in transverse metacarpal fractures has the best functional outcomes. The aim of this study was to compare the hand strength obtained using two different methods in the treatment of these fractures. Methods A total of 52 patients who presented a transverse metacarpal fracture were enrolled. They were divided in two groups: 26 patients treated with K-wire (IMN) and 26 patients treated with plate and screws (PW). The evaluation criteria were: fracture healing time, performed force testing collected ultimate tensile strength and grip, the Disability Arm Shoulder and Hand (DASH) score, and the range of motion of the hand. Results In both groups obtained results were comparable in terms of full hand function, healing and total range of motion and DASH. Results in group K were slightly better than group PW in terms of strength and grip pain within 3 months from osteosynthesis. Conclusion Neither of the two techniques, either in the literature or in biomechanical studies, shows to have superior functional outcomes for fixation of transverse metacarpal fractures. Since the K-wire is cheaper and has no intrinsic complications as compared with plating (such as scar and tendon irritation), fixation with the latter is preferable to the plate in the treatment of these fractures in non-expert hands.

Using intersection information to map stimulus information transfer within neural networks.

Analytical tools that estimate the directed information flow between simultaneously recorded neural populations, such as directed information or Granger causality, typically focus on measuring how much information is exchanged between such populations. However, understanding how sensory information is processed through the brain and how it is used to generate behaviors requires estimating specifically the amount of stimulus information that is transmitted. Here we use the concept of intersection information to make progress on how to perform this measure. We develop the concept of transmitted intersection information, which measures how much of the stimulus information present in one population at a certain time is transmitted to a second population at a later time. We show that this measure of stimulus-specific information transfer has several appealing properties, such as being non-negative, and being bounded by the amount of stimulus information present in each of the two populations and by the total amount of information transmitted between the two populations. Applying this measure to simulated neurons or pools of neurons connected by feed-forward synapses, we show that it can discern cases when the information transmitted from one population to another is about specific stimulus features encoded by the sending population from cases in which the information transmitted is not about the stimuli. We also show that this measure has a good statistical sensitivity from trial numbers that can be collected in real data. Our results highlight the promise of using the concept of intersection information to map stimulus-specific information transfer across neural populations.

Radiographic, Bone Densitometry and Clinic Outcomes Assessments in Femoral Shaft Fractures Fixed by Plating or Locking Retrograde Nail.

INTRODUCTION: Distal femoral shaft fractures are characterized by increasing incidence and complexity and are still considered a challenging problem (high morbidity and mortality). No consensus on best surgical option has been achieved. AIM: This study aims is to investigate radiographic, mineral bone densitometry and clinical outcomes of locking retrograde intramedullary (LRN) nailing and anatomical locking plate to surgically treat distal femoral shaft fractures in young adults based on the hypothesis that there is no statistical difference among the two surgical options in terms of results (radiographic, bone densitometry and outcomes assessment). METHODS: Retrospective study: 30 patients divided into 2 groups (Group 1 LRN, Group 2 Nailing). Average age was 42.67±18.32 for Group 1 and 42.84 ±18.32 for Group 2 (range of age 18-65 for both groups). Gender Ratio (male: female) was 2.75 (11:4) for both Group 1 and 2. AO Classification, NUSS and RUSH score, VAS, Dexa scans, plain radiographs were used. Evaluation endpoint: 12 months after surgery (mean follow up 16.24). RESULTS: No statistical difference in terms of surgery time, transfusions, wound healing. Similar results with regard to average time of bone healing, RUSH scores, VAS, regression between RUSH and VAS, average correlation clinical-radiographic results and patients outcomes. Only one patient of each group had reduction of mineral bone densitometry values. CONCLUSION: No statistical difference about the use of LNR or Nailing for treatment of distal femur shaft fractures in terms of radiographic, bone densitometry and outcomes has been found accordingly to our results. Good subjective and objective results are provided by both techniques. The choice among the two techniques must be based on surgeons' experience, indications and subjective patients' aspects. The absence of relevant similar data in the published literature does not allow definitive validation (or rejection) of our hypothesis. A more powered study with bigger cohort is needed for definitive validation.

Five year long term results of total joint arthroplasties in the treatment of trapeziometacarpal osteoarthritis.

INTRODUCTION: Trapeziometacarpal (TMC) osteoarthritis is a common disease. Patients with advanced disease who have failed conservative treatment have different surgical options, including total joint prosthesis. The aim of this study was to investigate the long-term outcome and complications of trapeziometacarpal (TMC) total arthroplasty. MATERIALS AND METHODS: One hundred and forty-seven patients with TMC osteoarthritis were surgically treated with TMC arthroplasty, and one hundred and thirty-seven patients were seen for follow-up (102 women and 35 men). At follow -up patients were asked to complete a visual linearanalogue scale (VAS) for satisfaction with the result of the operation and persisting pain from the thumb, the Spanish validated Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire was used to evaluate function of the affected hand.(9) The radiological examination consisted of posterior-anterior and oblique radiographs. In preoperative radiographs Eaton-Little was used, and in postoperative radiographs were assessed with regard to implant loosening and alignment. RESULTS: The subjective outcome was satisfactory in 126 cases (92 %), 14 (12 %) patients would undergo the same procedure in the other hand. The DASH questionnaireswere 19.55 (range 5.6-33,5) on average, and EVA was 1 on average. The mean key pinch strength was 5.8 Kg at 5 years follow-up. The most frequent postoperative complication was De Quervain tenosynovitis (21%), other complications were: Cup loosening (3.6%), traumatic dislocation (3,6%). The prosthesis was removed in nine cases (7%). There were four intraoperative complications. The survival rate for ARPE prosthesis was 92,7% at 60,5 months. TMC total arthroplasty offers a reliable treatment alternative in patients with thumb carpometacarpal joint osteoarthrosis which conservatives' treatment had failed. CONCLUSIONS: The TMC joint prosthesis is an option for patients with TCM osteoarthritis, provides satisfactory outcomes and has a low failure rate.(www.actabiomedica.it).

Foot Loading and Gait Analysis Evaluation of Nonarticular Tibial Pilon Fracture: A Comparison of Three Surgical Techniques.

The aim of our study was to investigate which technique among hybrid external fixation, plate and screws, and intramedullary nailing produces better outcomes in foot loading when treating type 43.A1, 43.A2, and 43.A3 fractures, according to the AO classification. From November 2011 to December 2014, 34 patients, including 25 (73.5%) males and 9 (26.5%) females with an average age of 32.3 (range 16 to 67) years, with a type A tibia fracture were treated with intramedullary nailing, plate and screws, or hybrid external fixation. The patients were divided into 3 groups: 16 (47%) received hybrid external fixation, 10 (29.4%) received plate and screw fixation, and 8 (23.5%) received intramedullary nailing fixation. The follow-up protocol included clinical and radiologic evaluations performed at 15 days, 1 month, 3 months, 6 months, and 12 months after surgery. The selected outcome parameters for the 3 groups were as follows: visual analog scale for pain of the traumatized tibia, interval from surgery to weightbearing, average time required for fracture recovery, subjective and objective Ovadia-Beals scores, baropodometric examination at 12 months, walking recovery at 12 months, outcomes, and surgical complications. The endpoint assessment was set at 12 months. The results showed that incorrect reduction of a type A tibia fracture can lead to changes in the sagittal balance line for foot loading and pace training. In conclusion, these findings have shown that the experience of the surgeon in the reduction of the fracture and knowledge of the method of synthesis is essential.

The Identity of Information: How Deterministic Dependencies Constrain Information Synergy and Redundancy.

Understanding how different information sources together transmit information is crucial in many domains. For example, understanding the neural code requires characterizing how different neurons contribute unique, redundant, or synergistic pieces of information about sensory or behavioral variables. Williams and Beer (2010) proposed a partial information decomposition (PID) that separates the mutual information that a set of sources contains about a set of targets into nonnegative terms interpretable as these pieces. Quantifying redundancy requires assigning an identity to different information pieces, to assess when information is common across sources. Harder et al. (2013) proposed an identity axiom that imposes necessary conditions to quantify qualitatively common information. However, Bertschinger et al. (2012) showed that, in a counterexample with deterministic target-source dependencies, the identity axiom is incompatible with ensuring PID nonnegativity. Here, we study systematically the consequences of information identity criteria that assign identity based on associations between target and source variables resulting from deterministic dependencies. We show how these criteria are related to the identity axiom and to previously proposed redundancy measures, and we characterize how they lead to negative PID terms. This constitutes a further step to more explicitly address the role of information identity in the quantification of redundancy. The implications for studying neural coding are discussed.

An inhibitory gate for state transition in cortex.

Large scale transitions between active (up) and silent (down) states during quiet wakefulness or NREM sleep regulate fundamental cortical functions and are known to involve both excitatory and inhibitory cells. However, if and how inhibition regulates these activity transitions is unclear. Using fluorescence-targeted electrophysiological recording and cell-specific optogenetic manipulation in both anesthetized and non-anesthetized mice, we found that two major classes of interneurons, the parvalbumin and the somatostatin positive cells, tightly control both up-to-down and down-to-up state transitions. Inhibitory regulation of state transition was observed under both natural and optogenetically-evoked conditions. Moreover, perturbative optogenetic experiments revealed that the inhibitory control of state transition was interneuron-type specific. Finally, local manipulation of small ensembles of interneurons affected cortical populations millimetres away from the modulated region. Together, these results demonstrate that inhibition potently gates transitions between cortical activity states, and reveal the cellular mechanisms by which local inhibitory microcircuits regulate state transitions at the mesoscale.

Exome sequencing identifies MAX mutations as a cause of hereditary pheochromocytoma.

Hereditary pheochromocytoma (PCC) is often caused by germline mutations in one of nine susceptibility genes described to date, but there are familial cases without mutations in these known genes. We sequenced the exomes of three unrelated individuals with hereditary PCC (cases) and identified mutations in MAX, the MYC associated factor X gene. Absence of MAX protein in the tumors and loss of heterozygosity caused by uniparental disomy supported the involvement of MAX alterations in the disease. A follow-up study of a selected series of 59 cases with PCC identified five additional MAX mutations and suggested an association with malignant outcome and preferential paternal transmission of MAX mutations. The involvement of the MYC-MAX-MXD1 network in the development and progression of neural crest cell tumors is further supported by the lack of functional MAX in rat PCC (PC12) cells and by the amplification of MYCN in neuroblastoma and suggests that loss of MAX function is correlated with metastatic potential.