Vaida Glatt

Putting 3D modelling and 3D printing into practice: virtual surgery and preoperative planning to reconstruct complex post-traumatic skeletal deformities and defects

3D printing technology has revolutionized and gradually transformed manufacturing across a broad spectrum of industries, including healthcare. Nowhere is this more apparent than in orthopaedics with many surgeons already incorporating aspects of 3D modelling and virtual procedures into their routine clinical practice. As a more extreme application, patient-specific 3D printed titanium truss cages represent a novel approach for managing the challenge of segmental bone defects. This review illustrates the potential indications of this innovative technique using 3D printed titanium truss cages in conjunction with the Masquelet technique. These implants are custom designed during a virtual surgical planning session with the combined input of an orthopaedic surgeon, an orthopaedic engineering professional and a biomedical design engineer. The ability to 3D model an identical replica of the original intact bone in a virtual procedure is of vital importance when attempting to precisely reconstruct normal anatomy during the actual procedure. Additionally, other important factors must be considered during the planning procedure, such as the three-dimensional configuration of the implant. Meticulous design is necessary to allow for successful implantation through the planned surgical exposure, while being aware of the constraints imposed by local anatomy and prior implants. This review will attempt to synthesize the current state of the art as well as discuss our personal experience using this promising technique. It will address implant design considerations including the mechanical, anatomical and functional aspects unique to each case.

A Concert between Biology and Biomechanics: The Influence of the Mechanical Environment on Bone Healing

In order to achieve consistent and predictable fracture healing, a broad spectrum of growth factors are required to interact with one another in a highly organized response. Critically important, the mechanical environment around the fracture site will significantly influence the way bone heals, or if it heals at all. The role of the various biological factors, the timing, and spatial relationship of their introduction, and how the mechanical environment orchestrates this activity, are all crucial aspects to consider. This review will synthesize decades of work and the acquired knowledge that has been used to develop new treatments and technologies for the regeneration and healing of bone. Moreover, it will discuss the current state of the art in experimental and clinical studies concerning the application of these mechano-biological principles to enhance bone healing, by controlling the mechanical environment under which bone regeneration takes place. This includes everything from the basic principles of fracture healing, to the influence of mechanical forces on bone regeneration, and how this knowledge has influenced current clinical practice. Finally, it will examine the efforts now being made for the integration of this research together with the findings of complementary studies in biology, tissue engineering, and regenerative medicine. By bringing together these diverse disciplines in a cohesive manner, the potential exists to enhance fracture healing and ultimately improve clinical outcomes.

Open versus arthroscopic surgical treatment for anterior shoulder dislocation : a comparative systematic review and meta-analysis over the past 20 years

BACKGROUND The purpose of this study was to perform a meta-analysis comparing open and arthroscopic surgery for the treatment of anterior shoulder instability by analyzing comparative studies during 2 different time intervals during the last 20 years. METHODS We conducted a systematic review of MEDLINE, Embase, Scopus, and Google Scholar. Two groups were created by dividing studies according to the year of publication, those published from 1995 to 2004 or from 2005 to 2015. Publication bias and risk of bias were assessed using the Cochrane Collaborations tools. Heterogeneity was assessed using the I2 statistics. RESULTS A total of 22 studies (n = 1633) met the eligibility criteria. Comparison of the pooled estimate for all of these studies demonstrated no significant differences (P = .64) in clinical outcomes between open and arthroscopic shoulder stabilization. However, studies published from 1995 through 2004 demonstrated significant differences (P = .015) in recurrence rates favoring open surgery. In contrast, no significant differences (P = .09) in recurrence rates were observed for studies published from 2005 through 2015. The pooled estimate for all studies in both groups demonstrated significant differences (P = .001) in external rotation deficits between open and arthroscopic shoulder stabilization favoring arthroscopic surgery. CONCLUSION Despite advances in surgical techniques and devices during the last 20 years, either open or arthroscopic surgical treatment of anterior shoulder dislocation results in similar clinical outcomes. The recurrence rate for arthroscopic surgical stabilization has only marginally decreased, from 16.8% to 14.2%. However, during the earlier decade from 1995 through 2004, patients treated with arthroscopic surgery had twice the risk of recurrence compared with an open procedure.

Bone transport versus acute shortening for the management of infected tibial non-unions with bone defects

INTRODUCTION This study compared bone transport to acute shortening/lengthening in a series of infected tibial segmental defects from 3 to 10cm in length. METHODS In a retrospective comparative study 42 patients treated for infected tibial non-union with segmental bone loss measuring between 3 and 10cm were included. Group A was treated with bone transport and Group B with acute shortening/lengthening. All patients were treated by Ilizarov methods for gradual correction as bi-focal or tri-focal treatment; the treating surgeon selected either transport or acute shortening based on clinical considerations. The principle outcome measure was the external fixation index (EFI); secondary outcome measures included functional and bone results, and complication rates. RESULTS The mean size of the bone defect was 7cm in Group A, and 5.8cm in Group B. The mean time in external fixation in Group A was 12.5 months, and in Group B was 10.1 months. The external fixation index (EFI) measured 1.8 months/cm in Group A and 1.7 months/cm in Group B (P=0.09). Minor complications were 1.2 per patient in the transport group and 0.5 per patient in the acute shortening group (P=0.00002). Major complications were 1.0 per patient in the transport group versus 0.4 per patient in the acute shortening group (P=0.0003). Complications with permanent residual effects (sequelae) were 0.5 per patient in the transport group versus 0.3 per patient in the acute shortening group (P=0.28). CONCLUSIONS While both techniques demonstrated excellent results, acute shortening/lengthening demonstrated a lower rate of complications and a slightly better radiographic outcome. Bone grafting of the docking site was often required with both procedures. LEVEL OF EVIDENCE Level III; Retrospective comparative study.

Orthopaedic research in Australia: a bibliographic analysis of the publication rates in the top 15 journals

To investigate the publications rates and characteristics of the authors for manuscripts originating from Australia in the 15 highest ranked orthopaedic journals over a 5‐year period.

The mechanical properties of fresh versus fresh/frozen and preserved (Thiel and Formalin) long head of biceps tendons: A cadaveric investigation

Human cadaveric specimens commonly serve as mechanical models and as biological tissue donors in basic biomechanical research. Although these models are used to explain both in vitro and in vivo behavior, the question still remains whether the specimens employed reflect the normal in vivo situation. The mechanical properties of fresh-frozen or preserved cadavers may differ, and whether they can be used to reliably investigate pathology could be debated. The purpose of this study was to therefore examine the mechanical properties of cadaveric long biceps tendons, comparing fresh (n=7) with fresh-frozen (n=8), formalin embalmed (n=15), and Thiel-preserved (n=6) specimens using a Universal Testing Machine. The modulus of elasticity and the ultimate tensile strength to failure was recorded. Tensile failure occurred at an average of 12N/mm2 in the fresh group, increasing to 40.1N/mm2 in the fresh-frozen group, 50.3N/mm2 in the formalin group, and 52N/mm2 in the Thiel group. The modulus of elasticity/stiffness of the tendon increased from fresh (25.6MPa), to fresh-frozen (55.3MPa), to Thiel (82.5MPa), with the stiffest being formalin (510.6MPa). Thiel-preserved and formalin-embalmed long head of biceps tendons and fresh-frozen tendons have a similar load to failure. Either the Thiel or formalin preserved tendon could therefore be considered as alternatives for load to failure studies. However, the Youngs modulus of embalmed tendons were significantly stiffer than fresh or fresh frozen specimens, and these methods might be less suitable alternatives when viscoelastic properties are being investigated.

Early or delayed reconstruction in multi-ligament knee injuries: A systematic review and meta-analysis

BACKGROUND Whether early or delayed surgical intervention in patients with multi-ligament injuries results in better outcomes, is of current and controversial debate. PURPOSE The purpose of this study was to perform a meta-analysis comparing early versus late surgical treatment of multi-ligament knee injuries. METHODS We performed a systematic review of Medline, Embase, Scopus, and Google Scholar to identify relevant studies in the English and German literature. Eligibility criteria included studies comparing early or delayed surgical interventions for multi-ligament knee injuries, with a minimum follow-up of two years, reporting the primary clinical outcome using a validated functional scoring system and range of motion. Exclusion criteria were patients treated with multi-trauma, head injury, non-union, lower extremity fractures, or a documented history of previous knee injuries. Publication bias was assessed by funnel plot, and the risk of bias was established using the Cochrane Collaborations risk of bias tool. Heterogeneity was assessed using χ2 and I2 statistic. RESULTS Eight studies (n=260 patients) were included in the analysis. 149 patients were treated early with a mean of 10.6days; 111 patients were treated late with a mean of 294days. The pooled estimate for clinical outcome demonstrated that early surgery resulted in significantly higher Lysholm scores (SMD 0.669, 95% CI: 0.379 to 0.959, p=0.0001, I2=0%). Thirty-one per cent of all patients with early surgery had a normal or near normal knee, whereas only 15% of patients with late reconstruction reported the knee to be normal or near normal. The pooled estimates for total ROM did not demonstrate a significant difference between the groups (SMD 0.113, 95% CI: -0.271 to 0.498, p=0.564, I2=35.57%). CONCLUSIONS The results of this meta-analysis suggest that early surgical intervention in multi-ligament injuries of the knee produces a significantly superior clinical outcome, compared to late reconstruction. Although an overall trend of improved total range of knee motion was also demonstrated, this was very small and unlikely to be clinically relevant. LEVEL OF EVIDENCE Level 4; Systematic review and meta-analysis.