Masters Degrees (Orthopaedics)

Permanent URI for this collection


Recent Submissions

Now showing 1 - 3 of 3
  • ItemOpen Access
    SI screw vs locking square plate fixation in sacroiliac joint disruption on composite bone models
    (University of the Free State, 2020-11) Kloppers, Frederik Jacobus; Van der Merwe, Johan Francois; Van Zyl, Allan Aubrey
    Background: The aim of this study was to compare a locked square plate to a standard sacroiliac screw of the sacroiliac joint on a composite pelvis bone model to assess the ultimate load tolerated before failure of fixation and to describe the mode of failure of the construct. Methods: Bilateral sacroiliac (SI) joint dislocations were created in 10 composite pelvic bone models. In this descriptive comparative study, the one SI joint was fixated using a 7.3mm cannulated screw and the contralateral side fixated using a 4-hole square locking plate. The pubic symphysis was not fixed. An upward vertical load was manually applied to each respective SI joint using a hook into the sciatic notch. The ultimate load to failure and the mode of failure was recorded for both groups. Results: The mean load to failure for the SI screw group was 310 N and for the SI plate group 580 N. The ultimate load to failure was significantly lower in the SI screw group (p=0.0002). There were no hardware-related failures recorded in any of the fixations in the study. The SI screw group had failure through a fracture of the sacrum in all the specimens. In the SI plate group, fractures of the sacrum and ilium constituted, respectively, 60% and 40%. Conclusion: A locked square plate fixation is superior to a single SI screw at the ultimate load to failure when a vertical load is applied to the sacroiliac joint in a composite bone model.
  • ItemOpen Access
    Condom sterility in periprosthetic joint infection management at Universitas academic hospital in Bloemfontein 2018
    (University of the Free State, 2020-04) Tyumre, Ntsikelelo; Van der Merwe, Johan; Maloba, Motlatji B.
    Joint replacement surgery, especially of the hip and knee, is one of the most rewarding operations for both the patient and the orthopaedic surgeon worldwide. Hip replacement has been dubbed the operation of the century. This is because these replacements improve the quality of life for the elderly population crippled with arthritis, and in recent years, due to better implants, also improves quality of life in the younger generation presenting with joint problems. It is, however, not without complications, the most important being periprosthetic joint infections. Other complications include aseptic loosening, periprosthetic fractures and dislocation. Periprosthetic joint infection is the most dreaded of the complications because of its difficulty to manage and association with significant morbidity and bone loss. We therefore began by describing and defining periprosthetic joint infection and investigated the current epidemiological data available. We have reviewed literature and looked at the diagnostic criteria from the different societies and meetings from around the world. Parvizi et al. developed an algorithm and proposed criteria that are based on the latest data and tests. This is explained in detail in the first chapter of this dissertation. The management of periprosthetic joint infection is dependent on the amount of time from the index joint surgery. An outline of the deferent management options are presented, while bearing in mind that two-stage revision surgery is the gold standard of management. Management of periprosthetic joint infection is associated with bone loss, either with the removal of infected implants or removal of the cement spacer in the second surgery of the twostage procedure. A recent unpublished study done locally in our department showed that putting a cement spacer in a condom and then placing the condom-cement spacer in the joint to allow it to set, and then taking out the condom-cement spacer after the cement had set, was associated with no bone loss. The study also showed that female condoms were stronger and more durable compared to the male condoms. The question that needed to be addressed, was whether it is safe to introduce condoms into the joint? Based on the literature, there is a 10% chance that condoms maybe contaminated. We investigated the sterility of condoms from the packaging and how to improve the sterility of the condoms. Sixty government-issued female condoms were used for the study, of which 30 were tested straight from the packaging and the other 30 were first put through hydrogen peroxide gas plasma sterilisation and then tested by means of MC&S. Similar to previously published studies, contamination of the condoms was confirmed, although in our study, the rate of contamination was 60%. We also isolated nonvirulent environmental and implant contaminants. The most important aspect of the results was that we were able to achieve 100% sterility of the condoms with hydrogen peroxide gas plasma. This was significant because we can place condoms for its intended use in the joints without introducing further infection in the joint. Once sterilised, condoms can also be used for other sterile/aseptic medical procedures, such as ultrasound probe covering and temperature probe covers.
  • ItemOpen Access
    Using a condom to prevent cement interdigitation into bone during the first stage of a two-stage revision arthroplasty for a periprosthetic joint infection
    (University of the Free State, 2018) Oosthuizen, Jannie; Van der Merwe, Johan
    Introduction and Aims: Total joint replacements are a universally accepted treatment in patients with end-stage osteoarthritis, post-traumatic arthritis, inflammatory arthritis, avascular necrosis of the femoral head as well as developmental dysplasia.1,2 Due to an ageing population the demand for these procedures are increasing. On the other hand complications associated with arthroplasty will also increase. It can be argued that the most devastating complication following arthroplasty is infection. Prosthetic infections are difficult to treat and usually requires revision surgery. Whether the revision is done in a single stage or as a two-staged procedure, it remains a challenge to remove the infected prosthesis and replace it with a temporary antibiotic spacer. If the spacer is inserted as for a primary or uninfected revision replacement, interdigitation of the cement into the interstitial spaces of the bone occurs. In non-infected primary or revision surgery this is desirable as this strengthens the bone-cement-interface resulting in a stable prosthesis. Once an implant becomes infected and a two-stage revision is planned, the very same strong bone-cement interface presents a serious problem. Removal of these infected implants can be very time-consuming. If one can prevent interdigitation of the cement at the time of insertion of the temporary cement spacer, it may significantly shorten the second stage of the procedure and possibly prevent complications. The purpose of this study is to determine if the interdigitation of bone cement into bone can be prevented by using a standard, government issued male or female condom during the first stage of a two-staged revision procedure. Methodology: The study was conducted in the dissection hall of the Department of Anatomy of the Faculty of Health Sciences at the University of the Free State. Eleven cadavers were available at the time of conducting the study. Standard government issued male and female condoms were used. A cross-sectional study design was used and the data was analysed by the Department of Biostatistics at the University of the Free State. Results: Twenty-one femurs and thirteen tibias were used. In the femur, we used a male condom in eleven cases and a female condom in ten cases. The condom was intact in one case and ruptured in ten cases when a male condom was used in the femur. No interdigitation of cement was seen during visual inspection in any of these cases. When a female condom was used it was intact in seven cases and not intact in three cases and no interdigitation was also noted in any of the cases. In the tibia we used a male condom in eleven and a female condom in two cases. The male condom was intact in eight cases and it ruptured in three cases with no interdigitation of cement noted. A female condom was used in only two cases and was intact in both of these with no interdigitation of cement on visual inspection. Without exception all the condoms, male and female, ruptured at the distal end covering the tip of the prosthesis whilst the part of the condom surrounding the prosthesis proximal to tip were intact and therefore prevented interdigitation of the cement. Although interdigitation was not observed in any of the cadavers, we found a statistical significant difference between intact male and female condoms when used in the femur (P = < 0.05). There was no statistical difference between intact male and female condoms when used in the tibia (P > 0.05). There was however a statistical significant difference when the intact condoms used in the tibia were compared to the intact condoms in the femur (P < 0.05). Conclusion: Our findings suggest that either a male or a female condom may be used to prevent interdigitation of cement into the trabecular bone. Using a standard government issued female condom is easier and more reliable when compared to using a standard government issued male condom. The utilization of a condom in the femur proved to be troublesome due to various reasons. Our study furthermore indicates that it is better to use a female condom in the femur. No cement interdigitation was noted upon inspection regardless of the condom used. Recommendations: We recommend that a standard government issued female condom may be used to prevent the interdigitation of cement into the trabecular bone in both the proximal femur and proximal tibia. The use of a male condom should be reserved for use in the tibia. Despite our findings in cadaveric models, further in vivo research is necessary before the technique can be advocated as safe to use in patients. Another study investigating the sterility of the condoms that were used are currently being undertaken at the UFS.