Periprosthetic femoral nonunions treated with internal fixation and bone grafting

Post-Stroke Environmental Enrichment Improves Neurogenesis and Cognitive Function and Reduces the Generation of Aberrant Neurons in the Mouse Hippocampus

Ischemic lesions stimulate adult neurogenesis in the dentate gyrus, however, this is not associated with better cognitive function. Furthermore, increased neurogenesis is associated with the formation of aberrant neurons. In a previous study, we showed that a running task after a stroke not only increases neurogenesis but also the number of aberrant neurons without improving general performance. Here, we determined whether stimulation in an enriched environment after a lesion could increase neurogenesis and cognitive function without enhancing the number of aberrant neurons. After an ischemic stroke induced by MCAO, animals were transferred to an enriched environment containing a running wheel, tunnels and nest materials. A GFP-retroviral vector was delivered on day 3 post-stroke and a modified water maze test was performed 6 weeks after the lesion. We found that the enriched environment significantly increased the number of new neurons compared with the unstimulated stroke group but not the number of aberrant cells after a lesion. Increased neurogenesis after environmental enrichment was associated with improved cognitive function. Our study showed that early placement in an enriched environment after a stroke lesion markedly increased neurogenesis and flexible learning but not the formation of aberrant neurons, indicating that rehabilitative training, as a combination of running wheel training and enriched environment housing, improved functional and structural outcomes after a stroke.

Operative treatment of nonunions in the elderly: Clinical and radiographic outcomes in patients at minimum 75 years of age

BACKGROUND

Limited information exists on nonunion treatment in the elderly. This retrospective study evaluates whether results of operative treatment of nonunion of the humerus or femur in patients aged ≥ 75 years are comparable to those in younger patients.

METHODS

We identified patients age ≥ 75 years with a nonunion of humerus or femur treated with open reduction and internal fixation. The Non-Union Scoring System was calculated. Complications, clinical outcome, and radiographic findings were assessed. Primary endpoint was nonunion healing. A literature review compared time to healing of humeral and femoral nonunion in younger populations.

RESULTS

We identified 45 patients treated for a nonunion of humerus or femur with > 12 months follow-up. Median age was 79 years (range 75-96). Median time to presentation was 12 months (range 4-127) after injury, median number of prior surgeries was 1 (range 0-4). Union rate was 100%, with median time to union 6 months (range 2-42). Six patients underwent revision for persistent nonunion and healed without further complications.

CONCLUSIONS

Using a protocol of debridement, alignment, compression, stable fixation, bone grafting and early motion, patients aged 75 years or older can reliably achieve healing when faced with a nonunion of the humerus or femur.

LEVEL OF EVIDENCE

IV.

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.

Mediation of mechanically adapted TiCu/TiCuN/CFR-PEEK implants in vascular regeneration to promote bone repair in vitro and in vivo

Background/Objective

TiCu/TiCuN is a multilayer composite coating comprising TiN and Cu, which provides excellent wear resistance and antibacterial properties. However, its applicability as a functional coating has not been widely realised, and several aspects pertaining to its properties must still be explored.

Methods

This study uses arc ion-plating technology to apply a TiCu/TiCuN coating on the surface of carbon fibre-reinforced (CFR) polyetheretherketone (PEEK) material.The safety and osteogenic activity of TiCu/TiCuN-coated CFR-PEEK materials were explored through cell experiments and animal experiments, and the molecules behind them were verified.

Results

The new material exhibits improved mechanical compatibility (mechanical strength and elastic modulus) and superior light transmittance (elimination of metal artifacts and ray refraction during radiology and radiotherapy). The proposed implant delivers excellent biocompatibility for mesenchymal stem cells and human umbilical vein endothelial cells (HUVECs), and it exhibits excellent osteogenic activity both in vitro and in vivo. Additionally, it was determined that the applied TiCu/TiCuN coating aids in upregulating the expression of angiogenesis-related signals (i.e., cluster-of-differentiation 31, α-smooth muscle actin, vascular endothelial growth factor receptor, and hypoxia-inducible factor-1α) to promote neovascularisation, which is significant for characterising the mechanism of the coating in promoting bone regeneration.

Conclusion

The current results reveal that the TiCu/TiCuN-coated CFR-PEEK implants may emerge as an advanced generation of orthopaedic implants.

Translational potential statement

The results of this study indicate that TiCu/TiCuN coating-modified CFR-PEEK materials can promote bone repair through angiogenesis and have broad clinical translation prospects.

Combined Surgical and Medical Treatment for Vancouver B1 and C Periprosthetic Femoral Fractures: A Proposal of a Therapeutic Algorithm While Retaining the Original Stable Stem

INTRODUCTION

There is lack of consensus regarding best operative fixation strategy for periprosthetic femoral fractures (PFFs) around a stable stem. Evidence exists that some patterns of fracture around a stable stem are better treated with revision surgery than with standard fixation. Anyway, a more aggressive surgical procedure together with medical treatment could allow for stem retention, and reduced risk of nonunion/hardware failure, even in these cases.

SIGNIFICANCE

This paper is placed in a broader context of lack of studies on the matter, and its aim is to shed some light on the management of PFFs around a stable stem, when peculiar mechanical and biological aspects are present.

RESULTS

Based on our casuistry in the treatment of nonunions after PFF successfully treated with original stem retention, and on review of Literature about risk factors for fixation failure, an algorithm is proposed that can guide in choosing the ideal surgical technique even for first-time PFFs with a stable stem, without resorting to revision. Mechanical (major and minor) and biological (local and systemic) factors that may influence fracture healing, leading to nonunion and hardware failure, and subsequent need for re-operation, are considered. The proposed surgical technique consists of rigid fixation with absolute stability (using a plate and structural allograft) plus local biological support (structural allograft and autologous bone marrow concentrate over a platelet-rich plasma-based scaffold) at fracture site. Systemic anabolic treatment (Teriparatide) is also administered in the post-operative period.

CONCLUSION

Mechanical factors are not the only issues to be considered when choosing the surgical approach to PFFs over a stable stem. Systemic and local biological conditions should be taken into account, as well. A therapeutic algorithm is proposed, given the prosthetic stem to be stable, considering mechanical and biological criteria.

The effects of locking inserts and overtorque on the mechanical properties of a large fragment locking compression plate

PURPOSE

The study was to determine the effect of locking hole inserts and their insertion torque on the fatigue life of a large fragment Locking Compression Plate (LCP) under bending forces.

METHODS

Fatigue strength of the LCP was examined using cyclic three-point bend testing at 80% yield strength of the construct. Locking hole inserts were used in 2, 4, and 6-hole of a 12-hole plate to simulate three different working lengths. Within each working length, plates were tested without locking inserts serving as the control group. In the experimental groups, inserts were tightened to manufacturer recommendations (4 Nm) and using overtorque (8 Nm).

RESULTS

Significantly fewer cycles to failure were observed in control groups versus the locking hole insert groups for all working lengths (2-hole: 4 Nm p = 0.003, 8 Nm p = 0.003; 4-hole: 4 Nm p = 0.02, 8 Nm p < 0.001; 6-hole: 4 Nm p = 0.004, 8 Nm p < 0.001). There was a statistically significant increase in fatigue strength when using overtorque in the 4-hole (p = 0.04) and 6-hole (p = 0.01) defect groups. This was not shown in the 2-hole defect group (p = 0.99).

CONCLUSIONS

By placing locking inserts in the empty locking regions of Combi holes along the working length, the number of cycles to failure was increased. Tightening inserts to twice the recommended insertion torque further increased cycles to failure in longer working length models. A longer fatigue life has the potential to decease the incidence of plate failure especially in the setting of delayed union due to poor intrinsic healing capacity, fractures in the geriatric population, osteoporosis and periprosthetic fractures.

Treatment Outcomes for Periprosthetic Femoral Fractures in Cementless Press-Fit Total Hip Replacement

OBJECTIVE

 The aim of this study was to report outcomes in dogs with periprosthetic femoral fractures associated with a press-fit cementless femoral total hip replacement implant.

MATERIALS AND METHODS

 Electronic medical records and digital radiographs were used to identify dogs with periprosthetic femoral fractures associated with press-fit cementless total hip replacement. Data collected included signalment, weight, time of fracture, cause of fracture, presence of intra-operative fissure, fracture type, repair technique, and clinical and radiographic outcomes. Long-term patient outcome was assessed by communication with owners or referring veterinarians.

RESULTS

 Twenty-eight dogs with femoral fracture repair associated with cementless press-fit total hip replacement were identified. Eight of the fractures occurred intraoperatively and 20 occurred at a median of 2 days postoperatively. An oblique or spiral configuration was noted in 19 cases and 15 occurred at the distal end of the femoral stem (type B), with thirteen type B1, one type B2 and one type B3 fractures. Fractures were repaired with non-locking (18/28) or locking-plate fixation (10/28). Cerclage wire was applied around the plate and proximal bone segment in 17/28 dogs. Major complications occurred in 7/28 cases (five deep infection, two mechanical failures). Bone healing was noted in 21/23 cases, for which follow-up radiographic interpretation was available. Return to function was complete in 17 cases, acceptable in 8 cases and unacceptable in 3 cases.

CONCLUSIONS

 While cementless total hip replacement periprosthetic femoral fractures can be successfully repaired with lateral plate fixation, the risk of infection appears to be high.

Biomechanics of Periprosthetic Fixation: Plates, Nails, Cables, and Allografts

Periprosthetic fractures (PPFs) present unique challenges to orthopaedic surgeons in terms of limited cortical fixation options, poor bone quality, cement mantles, and stress risers introduced from the prosthesis. Various fixation strategies have been used in PPFs including the use of intramedullary nails, locked plates, unicortical locking screws, cerclage wires and cables, double-plating techniques, and allograft struts. Here, we will review the biomechanics of various fixation strategies used in PPFs.