The evolution of OPS™ continues with the recent addition of the femoral planning tool. Prosthesis type and size can now be virtually positioned to understand changes in leg length, offset and femoral version and their impact on the patient’s hip alignment. Once the plan has been agreed, a 3D printed patient specific osteotomy guide is provided, enabling simple and accurate intraoperative implementation (Riddell et al. 2015).
Since 2013, Corin’s Optimized Positioning System (OPS™) has been used in over 2500 total hip replacement surgeries in Australia, Germany, Austria and the UK, enabling preoperative functional analysis for each patient. The femoral planning system complements Corin’s unique OPS™ acetabular planning platform to provide a comprehensive total hip replacement solution.
Early validation work has shown encouraging results, with 85% of achieved osteotomies being executed to within 1mm of the preoperative plan (Riddell et al. 2015). By accurately controlling the resection level, the surgeon has the potential to better control biomechanical parameters, while also managing the definitive position of the femoral component during total hip replacement. This 3D–based femoral plan also contains detailed information to flag key ‘watch-outs’ to the surgeon preoperatively, thereby reducing unexpected decision complexities within the operating room. The product is soon to be released more widely as interest continues to grow in key markets around the globe. Importantly, the technology continues to be supported by a strong foundation of clinical research, with multiple case series being exhibited at a number of key orthopaedic congresses. This year results have been presented at meetings including ICJR (Sydney), JSRA (Osaka), AAOS (Orlando), COMOC (Capetown) and will continue at SICOT (Rome), BOA (Belfast), ISTA (Boston), AOA (Cairns) and DKOU (Berlin).
What do you see as the major challenges in THR today?
A key challenge in total hip replacement is the ability of the surgeon to correctly select and orient prostheses intraoperatively. To do this appropriately, a thorough understanding of a number of patient specific variables is required. One of the most significant factors is the dynamic behavior of the pelvis and lumbar spine – which can vary
significantly from one patient to the next. This variation can provide important information to the surgeon to help make the most appropriate decision as to the design of prosthesis and bearing surface to be utilised in surgery.
What role do patient specific factors play when planning and performing a THR?
Patient specific variables play a key role in the planning and execution of a total hip replacement. Aspects such as age, gender, weight, sports activities, physical and psychological health status need to be carefully considered in the planning phase. Knowledge of these factors helps the surgeon to better profile each patient and understand their postoperative expectations. Further, by understanding the dynamics of the pelvis and lumbar spine in functional positions, we can better comprehend their range of motion requirements as well as the risk of instability during flexion and extension manoeuvers.
How do you use the information provided by OPS™ in your THR practice?
OPS™ provides detailed, patient specific information for me to better plan and execute a total hip replacement. The preoperative dynamic analysis provides key information that enables me to target and achieve a personalised safe zone for the placement of the acetabular component. In addition, OPS™ also gives me the ability to accurately reconstruct leg length and offset, giving me added confidence that function and stability are better restored postoperatively. In combination, this has given me the ability to optimise outcomes and achieve predictably high levels of patient satisfaction.