Journal of Musculoskeletal Research

Introduction: Additive manufacturing, also known as 3D printing (3DP), is becoming increasingly available to surgeons throughout the world due to recent advancements in technology. 3D printing can produce complex free-form structures that would be impossible using conventional subtractive manufacturing. This offers the possibility to create implants that are better suited to the irregular anatomic shapes found in the human body. The present study aims to examine the surgical outcomes associated with the use of 3D printed metal implants and uncover the value of 3D printing in musculoskeletal surgery. Methods: A systematic review of published literature was performed in June 2017 using the PRISMA protocol. Online bibliographic databases such as MEDLINE, Embase, Scopus, CINAHL, and Cochrane were used to identify studies involving surgical implantation of 3D printed metal implants in musculoskeletal surgery. References from relevant studies were scanned for additional articles. Two reviewers independently screened results. Full-text articles were analyzed for eligibility. A total of 24 studies were included for data abstraction. Results were collected and qualitatively analyzed. Results: Of the 25 articles included, there were 17 case reports, 4 case series, 2 retrospective cohorts and 3 prospective cohorts. Of these articles, the majority of 3DP was done with electron beam melting (EBM) with Ti6Al4V. Orthopaedic, neurosurgical, plastic, and maxillofacial surgery articles were included in the review. All studies concluded that 3D printed implants had favourable post-operative outcomes. Some advantages included the reduction of operative time, improved osseointegration through custom implant porosity, improved fixation, decreased stress shielding, better cosmetic appearance, improved functional outcome, and limb salvage. Additional cost and time required to design and print the implants were reported as potential drawbacks to 3D printing. Discussion/Conclusions. The applications of 3D printing in musculoskeletal surgery are promising and have the potential to alter future surgical practice. However, there is a lack of quality research in the literature assessing the use of 3D printed implants. Further research is needed to evaluate the use of 3D printing in musculoskeletal surgery to understand its potential effects on surgical practice.

Purpose: The knowledge of the normal geometrical characteristics of the proximal humerus is crucial to the success of its arthroplasty. This important information, is however, limited for the South African population. Therefore, this study investigates the three-dimensional morphometric parameters, specifically examining the intra-ancestral differences within the South African population. Methods: With the aid of geometry extraction techniques, various morphometric characteristics were measured on South African cadaveric humeri originating from three ethnicities including whites, blacks, and mixed in the ratio 1:2:4. Results: There is a significant mean difference in humeral head diameter between blacks and whites and between mixed and whites with a mean difference of $-$4.86, 95% CI ($-9.40$, $-0.32$) and $-4.50$, 95% CI ($-8.56$, $-0.44$), respectively. Similarly, for articular surface diameter, a significant mean difference of $-4.58$, 95% CI ($-9.10$, $-0.0646$) and $-4.32$, 95% CI ($-8.36$, $-0.2854$) were recorded between blacks and whites and between mixed and whites, respectively. Conclusion: The outcome of our study showed that the shape of the South African proximal humerus varies distinctively within the different ethnicities that were measured. The findings from this study may provide the data required to design and develop a new shoulder implant appropriate for South African patients.

There is limited evidence for the utilization of physiotherapy in the management of sub-acute sciatica. The aim of this study is to reach consensus on physiotherapeutic approaches to the management of sub-acute sciatica amongst a panel of clinicians experienced in this field. The Delphi method was chosen as the process. The panel comprised expert physiotherapists ($n=11$) working within a musculoskeletal outpatient setting within the United Kingdom National Health Service. Iteration 1 consisted of the open-ended question ‘List the treatment approaches/techniques/modalities you employ when treating a patient with sub-acute sciatica and provide justifications’. Themes reaching 70% consensus progressed to the second iteration which followed up with the question “Please indicate how frequently you would employ the following treatments in the management of sub-acute sciatica” using a 5-point likert scale ranging from 1 (never) to 5 (always). The mean score was calculated for each treatment and those themes achieving a mean of 3.5 or greater progressed to iteration 3 “Please rank in order of preference which of the following treatments you would employ in the treatment of sub-acute sciatica”. The response rate at iteration 3 was 100%. This study achieved consensus on two treatment approaches to be employed in the management of sub-acute sciatica. These treatments were advice on the nature and natural history of the condition and self-help activities such as heat/ice, staying active and rest when needed.

Introduction. To evaluate the incidences of union, nonunion and infection in the treatment of open tibial shaft fractures of Gustilo–Anderson types I, and IIIA treated with primary unreamed solid intramedullary locked nail (UTN). Materials and Methods. It is a prospective study of 80 open tibial shaft fractures. According to the AO classification, 36 patients (44%) were of type A, 29 (36%) were of type B and 15 (18%) were of type C. According to the Gustilo–Anderson classification, 31 patients (38.7%) were of grade I, 24 (30%) were of grade II and 25 (31%) were of grade IIIA. For the definitive stabilization of the fracture was used a UTN. Results. Bone healing was achieved in 98.4% of the cases, with a mean time of 24.2 weeks, ranging from 14 weeks to 110 weeks. Union without infection was seen in 70 patients (87%) and nonunion was seen in five patients (6%). Deep infection was seen in three patients (3.7%) and malunion was seen in two patients (2.5%). Conclusion. The treatment of open tibial shaft fractures with unreamed solid intramedullary locked nail allows high rates of bone healing and low rates of nonunion and deep infection, and if the presence of infection is excluded, then the results of unreamed nailing and reamed nailing are the same.

Purpose: Most interference screws (IFS) for anterior cruciate ligament (ACL) reconstruction are manufactured from traditional materials like titanium. The advent of degradable metals (i.e. magnesium (Mg) alloys) has shown great promise for numerous orthopedic applications, including IFS for ACL replacement. Questions surrounding the mechanical integrity of degradable Mg alloys, as well as the impact of design changes on behavior, are still unanswered. The purpose of this research was to determine the impact of thread shape, diameter and screw taper on pullout strength of Mg-based IFS. Methods: Four different thread shapes were modeled, and analyzed, using finite element analysis. It was hypothesized that the thread shape, diameter and taper of the screw would significantly impact the pullout performance of the screw. Results: A buttress design resulted in the highest reaction (pullout) force (1247N) providing the greatest hold. Conclusion: Results of this study indicate that design factors impact pullout force and suggest thread shape, taper, and major diameter having the greatest impact.