Asymmetric Post-Traumatic Knee Arthritis Is Closely Correlated With Both Severity and Time for Lower Limb Coronal Plane Malalignment.

OBJECTIVE: Mechanical alignment of the lower limbs has been suggested to cause abnormal uneven loading across the compartments at the knee, but its contribution to the initiation and progression of arthritis remains controversial. This study aimed to establish whether malalignment of the lower limb after trauma is associated with worsened arthritis scores in the theoretically overloaded compartment, and if arthritis scores continuously correlate with the degree of malalignment and time with deformity. DESIGN: After screening 1160 X-rays, 60 patients were identified with long-leg radiographs > 2 years after fracture. Measurement of mechanical axis deviation (MAD) divided into groups of varus malalignment (n = 16, >16 mm), valgus (n = 25, <0 mm), and normal alignment (n = 19). Alignment and bilateral knee compartmental arthritis scores were recorded by three clinicians, compared via analysis of variance and assessed with linear regression against time since injury using MAD as a covariate. RESULTS: In varus and valgus malalignment, there was a greater mean arthritis score in the "overloaded" compartment compared to the contralateral side, with varus medial Osteoarthritis Research Society International (OARSI) scores 5.17 ± 2.91 vs 3.50 ± 2.72 (P = 0.006) and Kellegren-Lawrence scores 2.65 ± 1.19 vs 1.79 ± 1.24 (P ≤ 0.001). In a linear regression model, OARSI arthritis score was significantly associated with absolute MAD (0.6/10 mm MAD, P < 0.001) and time (0.7/decade, P ≤ 0.001). CONCLUSIONS: Malalignment consistently results in more advanced arthritis scores in the overloaded compartment, most likely related to abnormal loading across the knee. Severity of arthritis using OARSI grading continuously correlates with degree of malalignment and time with deformity after post-traumatic malunion.

Treatment of Metaphyseal Defects in Plated Proximal Humerus Fractures with a New Augmentation Technique-A Biomechanical Cadaveric Study.

Background and Objectives: Unstable proximal humerus fractures (PHFs) with metaphyseal defects-weakening the osteosynthesis construct-are challenging to treat. A new augmentation technique of plated complex PHFs with metaphyseal defects was recently introduced in the clinical practice. This biomechanical study aimed to analyze the stability of plated unstable PHFs augmented via implementation of this technique versus no augmentation. Materials and Methods: Three-part AO/OTA 11-B1.1 unstable PHFs with metaphyseal defects were created in sixteen paired human cadaveric humeri (average donor age 76 years, range 66-92 years), pairwise assigned to two groups for locked plate fixation with identical implant configuration. In one of the groups, six-milliliter polymethylmethacrylate bone cement with medium viscosity (seven minutes after mixing) was placed manually through the lateral window in the defect of the humerus head after its anatomical reduction to the shaft and prior to the anatomical reduction of the greater tuberosity fragment. All specimens were tested biomechanically in a 25° adduction, applying progressively increasing cyclic loading at 2 Hz until failure. Interfragmentary movements were monitored by motion tracking and X-ray imaging. Results: Initial stiffness was not significantly different between the groups, p = 0.467. Varus deformation of the humerus head fragment, fracture displacement at the medial humerus head aspect, and proximal screw migration and cut-out were significantly smaller in the augmented group after 2000, 4000, 6000, 8000 and 10,000 cycles, p ≤ 0.019. Cycles to 5° varus deformation of the humerus head fragment-set as a clinically relevant failure criterion-and failure load were significantly higher in the augmented group, p = 0.018. Conclusions: From a biomechanical standpoint, augmentation with polymethylmethacrylate bone cement placed in the metaphyseal humerus head defect of plated unstable PHFs considerably enhances fixation stability and can reduce the risk of postoperative complications.

Statistical Morphology and Fragment Mapping of Complex Proximal Humeral Fractures.

Background and Objectives: Proximal humerus fractures (PHFs) are common in the elderly, but the treatment results are often poor. A clear understanding of fracture morphology and distribution of cortical bone loss is important for improved surgical decision making, operative considerations, and new implant designs. The aim of this study was to develop a 3D segmentation fracture mapping technique to create a statistical description of the spatial pattern and cortical bone loss of complex PHFs. Materials and Methods: Fifty clinical computed tomography (CT) scans of complex PHFs and their contralateral intact shoulders were collected. In-house software was developed for semi-automated segmentation and fracture line detection and was combined with manual fracture reduction to the contralateral template in a commercial software. A statistical mean model of these cases was built and used to describe probability maps of the fracture lines and cortical fragments. Results: The fracture lines predominantly passed through the surgical neck and between the tuberosities and tendon insertions. The superior aspects of the tuberosities were constant fragments where comminution was less likely. Some fracture lines passed through the bicipital sulcus, but predominantly at its edges and curving around the tuberosities proximally and distally. Conclusions: A comprehensive and systematic approach was developed for processing clinical CT images of complex fractures into fracture morphology and fragment probability maps and applied on PHFs. This information creates an important basis for better understanding of fracture morphology that could be utilized in future studies for surgical training and implant design.

A Novel Technique for Treatment of Metaphyseal Voids in Proximal Humerus Fractures in Elderly Patients.

Background and Objectives: The treatment of proximal humerus fractures in elderly patients is challenging, with reported high complication rates mostly related to implant failure involving screw cut-out and penetration. Metaphyseal defects are common in osteoporotic bone and weaken the osteosynthesis construct. A novel technique for augmentation with polymethylmethacrylate (PMMA) bone cement was developed for the treatment of patients in advanced age with complex proximal humerus fractures and metaphyseal voids, whereby the cement was allowed to partially cure for 5-7 min after mixing to achieve medium viscosity, and then it was manually placed into the defect through the traumatic lateral window with a volume of 4-6 mL per patient. The aim of this retrospective clinical study was to assess this technique versus autologous bone graft augmentation and no augmentation. Materials and Methods: The outcomes of 120 patients with plated Neer three- and four-part fractures, assigned to groups of 63 cases with no augmentation, 28 with bone graft augmentation and 29 with cement augmentation, were assessed in this study. DASH, CS, pain scores and range of motion were analyzed at 3, 6 and 12 months. Statistical analysis was performed with factors for treatment and age groups, Neer fracture types and follow-up periods, and with the consideration of age as a covariate. Results: DASH and CS improved following cement augmentation at three and six months compared to bone grafting, being significant when correcting for age as a covariate (p ≤ 0.007). While the age group had a significant effect on both these scores with worsened values at a higher age for non-augmented and grafted patients (p ≤ 0.044), this was not the case for cement augmented patients (p ≥ 0.128). Cement augmentation demonstrated good clinical results at 12 months with a mean DASH of 10.21 and mean CS percentage of 84.83% versus the contralateral side, not being significantly different among the techniques (p ≥ 0.372), despite the cement augmented group representing the older population with more four-part fractures. There were no concerning adverse events specifically related to the novel technique. Conclusions: This study has detailed a novel technique for the treatment of metaphyseal defects with PMMA cement augmentation in elderly patients with complex proximal humerus fractures and follow-up to one year, whereby the cement was allowed to partially cure to achieve medium viscosity, and then it was manually placed into the defect through the traumatic lateral window. The results demonstrate clinically equivalent short-term results to 6 months compared to augmentation with bone graft or no augmentation-despite the patient group being older and with a higher rate of more severe fracture patterns. The technique appears to be safe with no specifically related adverse events and can be added in the surgeon's armamentarium for the treatment of these difficult to manage fractures.

Tips and tricks to avoid implant failure in proximal femur fractures treated with cephalomedullary nails: a review of the literature.

Objective: To describe the surgical aspects potentially contributing to hardware failure of cephalomedullary nails. Data Sources: A search of the Embase, PubMed (MEDLINE), Web of Science, and the Cochrane library for reports of hardware failures after intramedullary fixation of proximal femur fractures. Issues of cut out and cut through phenomena related to technique were excluded. Expert opinion of 3 surgeons, each trained on several fixation systems at Level | trauma centers is reported. Data Extraction: Three authors extracted data using a predesigned form. Implant type, reported failure mechanism, and associated factors with implant failure were recorded as well as potential bias. Results: Of 2182 search results screened, 64 articles were deemed relevant for our research question and were included. The authors identified factors associated with implant failure: preoperative patient and fracture characteristics, intraoperative reduction, implant handling, and postoperative nonunion. Issues were identified as independent modifiable intraoperative risk factors: inadequate fracture reduction, varus position of femoral neck, direct damage of the cephalomedullary nail aperture by eccentric drilling related to guide sleeve handling, and implant design mechanism failures. Conclusions: Multiple factors associated with intraoperative handling can influence the healing of proximal femur fractures. Although many of these have been well described and are taught in fracture courses, surgeons should be aware of subtle intraoperative complications reported in the literature that can weaken implants and add to the likelihood of early failure.Level of Evidence: IV.

Low-profile dual mini-fragment plating of diaphyseal clavicle fractures. A biomechanical comparative testing.

BACKGROUND: Implant removal rates after clavicle plating are high. Recently, low-profile dual mini-fragment plate constructs have revealed lower implant removal rates following fixation of diaphyseal clavicle fractures. However, they have not been subject to a biomechanical investigation. AIMS: To: (1) investigate thebiomechanical competence of different dual plate designs and (2) compare them against single superoanterior plating. METHODS: Twelve artificial clavicles with a simulated AO/OTA 15.2C unstable diaphyseal clavicle fracture were assigned to 2 groups and instrumented with dual titanium mandible plates as follows: Group 1 - 2.5 mm anterior plus 2.0 mm superior (2.5/2.0); Group 2 - 2.0 mm anterior plus 2.0 mm superior (2.0/2.0). Specimens were cyclically tested to failure under craniocaudal cantilever bending superimposed with torsion around the shaft axis and compared to previous published data acquired using 6 locking superoanterior plates tested under the same conditions (Group 3). FINDINGS: Initial stiffness was highest in Group 1 followed by Group 2 and Group 3, being significantly different between Group 1 and Group 3 (p = 0.020). Displacement after 5000 cycles was biggest in Group 3, followed by Group 2 and Group 1, with significant differences between Group 3 and both Group 1 and Group 2 (p ≤ 0.027). Cycles to failure were highest in Group 3 followed by Group 1 and Group 2, being significantly different between Group 2 and Group 3 (p = 0.004). INTERPRETATION: Low-profile 2.0/2.0 dual plates demonstrated similar initial stiffness compared with single 3.5 mm locking plates, however, they revealed significantly lower resistance to failure. Moreover, low-profile 2.5/2.0 dual plates demonstrated significantly higher initial stiffness and similar resistance to failure compared with single 3.5 mm locking plates and can therefore be considered as their useful alternative for diaphyseal clavicle fracture fixation.

The history of suture anchors in orthopaedic surgery.

The suture anchor allows secure fixation of soft tissue to bone and has become an invaluable tool for the orthopaedic surgeon. The original suture anchor was developed over 3 decades ago when a suture was bonded to a headless screw. Since then anchors have undergone a wide variety of design modifications to increase strength and allow for new applications based on biomechanical and clinical evidence. The suture anchor chain consists of the anchor to bone fixation, anchor suture interface, suture itself and suture to soft tissue interface. The early suture anchors failed most commonly from anchor pull out or breakage, with the strongest early design being a bone-screw-suture complex. Early concerns of metalwork complications saw the introduction of biodegradable suture anchors, originally lactic acid polymers and then osteoconductive bio-composites. Improvements in anchor design saw the suture become the main link of failure until the advent of novel suture materials made of ultrahigh molecular weight polyethylene. A form failure of suture at the anchor eyelet via cut-out led to redesign of the anchor suture interface with novel eyelet designs. Further innovations in the anchor suture interface have seen the advent of knotless anchors, especially useful in arthroscopic surgery. The newest products are all-suture anchors which show impressive strength whilst reducing the iatrogenic damage caused by insertion. The further biomechanical development of suture anchors is likely to produce new designs that continue to increase strength whilst managing size requirements for tailored clinical applications.

3D printed Polycaprolactone scaffolds with dual macro-microporosity for applications in local delivery of antibiotics.

Advanced scaffolds used in tissue regenerating applications should be designed to address clinically relevant complications such as surgical site infection associated with surgical procedures. Recognizing that patient-specific scaffolds with local drug delivery capabilities are a promising approach, we combined 3D printing with traditional salt-leaching techniques to prepare a new type of scaffold with purposely designed macro- and micro-porosity. The dual macro/micro porous scaffolds of medical-grade polycaprolactone (mPCL) were characterized for their porosity, surface area, mechanical properties and degradation. The use of these scaffolds for local prophylactic release of Cefazolin to inhibit S. aureus growth was investigated as an example of drug delivery with this versatile platform. The introduction of microporosity and increased surface area allowed for loading of the scaffold using a simple drop-loading method of this heat-labile antibiotic and resulted in significant improvement in its release for up to 3 days. The Cefazolin released from scaffolds retained its bioactivity similar to that of fresh Cefazolin. There were no cytotoxic effects in vitro against 3 T3 fibroblasts at Cefazolin concentration of up to 100 µg/ml and no apparent effects on blood clot formation on the scaffolds in vitro. This study therefore presents a novel type of scaffolds with dual macro- and micro-porosity manufactured by a versatile method of 3D printing combined with salt-leaching. These scaffolds could be useful in tissue regeneration applications where it is desirable to prevent complications using local delivery of drugs.

Breast Augmentation and Reconstruction from a Regenerative Medicine Point of View: State of the Art and Future Perspectives.

Breast reconstruction and augmentation are very common procedures, yet the prevailing current methods utilize silicone implants that may have significant local complications requiring reoperation. Lipofillling is increasingly used to contour and is considered safe, however, its utility is limited by significant volume loss. A new approach could offer an alternative and increase the scope of patient choice. A small number of teams around the world are investigating a breast tissue engineering (TE) paradigm. Conventional breast TE concepts are based on seeding a scaffold with the patients' own stem cells. However, the clinical viability of many of these approaches is limited by their costs in relevant volumes. In this article the state of the art of tissue-engineered breast reconstruction is reviewed and future perspectives are presented and discussed.