The aim of this study is to print 3D polycaprolactone (PCL) scaffolds at high and low temperature (HT/LT) combined with salt leaching to induced porosity/larger pore size and improve material degradation without compromising cellular activity of printed scaffolds. PCL solutions with sodium chloride (NaCl) particles either directly printed in LT or were casted, dried, and printed in HT followed by washing in deionized water (DI) to leach out the salt. Micro-Computed tomography (Micro-CT) and scanning electron microscope (SEM) were performed for morphological analysis. The effect of the porosity on the mechanical properties and degradation was evaluated by a tensile test and etching with NaOH, respectively. To evaluate cellular responses, human bone marrow-derived mesenchymal stem/stromal cells (hBMSCs) were cultured on the scaffolds and their viability, attachment, morphology, proliferation, and osteogenic differentiation were assessed. Micro-CT and SEM analysis showed that porosity induced by the salt leaching increased with increasing the salt content in HT, however no change was observed in LT. Structure thickness reduced with elevating NaCl content. Mass loss of scaffolds dramatically increased with elevated porosity in HT. Dog bone-shaped specimens with induced porosity exhibited higher ductility and toughness but less strength and stiffness under the tension in HT whereas they showed decrease in all mechanical properties in LT. All scaffolds showed excellent cytocompatibility. Cells were able to attach on the surface of the scaffolds and grow up to 14 days. Microscopy images of the seeded scaffolds showed substantial increase in the formation of extracellular matrix (ECM) network and elongation of the cells. The study demonstrated the ability of combining 3D printing and particulate leaching together to fabricate porous PCL scaffolds. The scaffolds were successfully printed with various salt content without negatively affecting cell responses. Printing porous thermoplastic polymer could be of great importance for temporary biocompatible implants in bone tissue engineering applications.

Mesenchymal stem cells (MSC) have been used for bone regenerative applications as an alternative approach to bone grafting. Selecting the appropriate source of MSC is vital for the success of this therapeutic approach. MSC can be obtained from various tissues, but the most used sources of MSC are Bone marrow (BMSC), followed by adipose tissue (ASC). A donor-matched comparison of these two sources of MSC ensures robust and reliable results.

Despite the similarities in morphology and immunophenotype of donor-matched ASC and BMSC, differences existed in their proliferation and in vitro differentiation potential, particularly osteogenic differentiation that was superior for BMSC, compared to ASC. However, these differences were substantially influenced by donor variations. In vivo, although the upregulated expression of osteogenesis-related genes in both ASC and BMSC, more bone was regenerated in the calvarial defects treated with BMSC compared to ASC, especially during the initial period of healing. According to these findings, compared to ASC, BMSC may result in faster regeneration and healing, when used for bone regenerative applications.

There are many types of arthroplasties for the 1st MTPJ, but still the treatment of advance Hallux rigidus remains controversial. In this study we are reporting the outcome of the North Star hemicap at 6 months.

A series of patients under the care of a single surgeon were followed using the Manchester - Oxford Foot Questionnaire (MOXFQ) at 6months post operation, and a satisfaction question was asked. The operations were between August 2011 and August 2013. A total of forty five arthroplasties were implanted in 44 patients. Thirty four of them were female and 9 were male. The average age was 56 years (range 37–77 years).

Twenty six out of them (59%) needed an MUA + a local anaesthetic and steroid injection of the prosthetic joint at 2 to 14 months (average 6 months) post implantation. In these patients the MOXFQ was filled at 6months post the MUA and injection. Four of them were left out of the study because they were less than 6months post MUA. One patient had his implant removed and changed to fusion at his request at 14 months post implantation.

Forty one patients were satisfied and would recommend the operation, 2 were disappointed with the degree of movement but would still recommend the operation and one had it revised to fusion. The average MOXFQ was 12/64. In conclusion, high percentage of patients needed a second operation, but the scores are reasonably low and almost all patients would recommend it. Further follow up of these patients is needed for at least 5years but the early results are showing it to be a good alternative for fusion.

Purpose: Numerous implants used in repairing a trochanteric fracture of the hip are currently available. The purpose of this prospective study was to determine the complications and results of the percutaneous compression plate (PCCP), a relatively new device versus the conventional dynamic hip screw (DHS).

Materials and Methods: Between 2001–2003, 110 consecutive patients with trochanteric fractures were treated in our department. Fifty-five fractures were stabilized using the PCCP and 55 fractures were treated with the DHS. Results were analyzed according to fracture pattern, type of implant, quality of fracture reduction and position of implant. Function was assessed on the basis of pain, walking aids and walking capability.

Results: Forty-seven (85%) of 55 hips treated with PCCP healed without additional treatment and complications. Forty-three (78%) treated with DHS healed without additional treatment and complications. Complications among 8 patients (15%) of the PCCP group were: deep vein thrombosis, cardiac complication, chest infection and pressure sores. Complications among 12 patients (22%) of the DHS group were: implant failure (7%), deep wound infection, deep vein thrombosis and pressure sores.

Conclusions: Use of the PCCP implant provides similar and occasionally better results compared to those obtained with the conventional DHS device. The most outstanding advantage of the PCCP device was no implant failure or implant cut out.

Purpose: Total knee arthroplasty has been established as a reliable treatment modality for advanced gonarthrosis. Satisfactory outcome depends on restoration of the neutral alignment of the leg. Our study evaluates whether computer-assisted navigated knee arthroplasty achieves a more accurate knee alignment.

Materials and Methods: In a prospective study two groups of 24 patients undergoing TKA had operations using either a computer-assisted navigation system or a conventional technique. Limb alignment and component orientation were determined on post-operative coronal and lateral X-rays.

Results: In our study the post operative axis of the thumb was significantly better in the computer-assisted group (94%, within ±3^° varus/valgus) compared with the conventional group (82%, within ±3° varus/valgus). A significantly better orientation of the femoral and the tibial components was achieved in the computed-assisted navigated group.

Conclusions: Computer-assisted navigated TKA gives better correction of leg alignment and components orientation as we saw in the computer-assisted navigated group. Potential benefits in the long-term outcome and functional improvement require further investigation.

Purpose: Conducting a prospective study comparing the short-term results of minimally invasive total knee replacement surgery using a conventional prosthesis (i.e. not specifically designed for minimally invasive surgery – MIS, AGC Biomet) with knee arthroplasties performed via a transvastus approach.

Operative Technique: MIS knee arthroplasty is performed via a medial parapatellar skin incision from the supero-medial pole of the patella to the tibial tuberosity. The major difference is the lack of quadriceps muscle dissection and the lack of patellar inversion. The instruments fit into the incision, though some of the pins have to be inserted percutaneously. In order to reduce patello-femoral pressure and pain, an osteophytectomy is performed followed by sawing a slice of the patella and denervation using a diathermy. The wound is closed with intra-dermal sutures and a drain is not used.

Materials and Methods: Forty-five consecutive knee replacements were randomized into either a conventional trans-vastus approach (22 patients) or a minimally invasive procedure (23 patients). The patients were assessed using an HSS knee score, a VAS score and knee range of motion every day during hospitalization was recorded separately. Blood consumption and length of hospitalization were recorded as well. The patients were followed for a minimum of 3 months. Radiographic evaluation included prosthesis alignment in the AP and lateral views.

Results: Pre-op age, sex, VAS score and HSS were similar in both groups. Initial limb alignment averaged 9 degrees of varus in both groups. Pre-op range of motion was similar in both groups -5 degrees of extension and 90 degrees of flexion. Operative time was similar in both groups. Length of hospital stay was similar in both groups. Blood usage was diminished in the MIS group by an average of 0.8 units.

At the 2-weeeks and 6-weeks time-point the range of motion in the MIS group was better both in flexion and in extension by an average of 20 degrees, than in the conventional surgery group. This difference was nullified at the 3 months time-point. Radiographic alignment was similar in both groups. The limb alignment post-op averaged 3 degrees of varus.

Conclusions: MIS knee arthroplasty appears to yield similar results to conventional arthroplasty regarding prosthesis alignment and hospitalization.