Benjamin Adamczewski

Comparison of the pre-shaped anatomical locking plate of 3.5 mm versus 4.5 mm for the treatment of tibial plateau fractures.

PurposeTreatment of tibial plateau fractures is discussed. A retrospective comparative study of fractures treated with an anatomical locking plate of 4.5xa0mm or 3.5xa0mm. Our hypothesis is that the 3.5xa0mm plates give an equivalent hold of fractures with comparable results and better clinical tolerance.MethodsFrom May 2010 to October 2011, 18 patients were operated on using a 4.5-mm LCP™ anatomical plate (group A) and 20 patients received a3.5-mm LCP™ anatomical plate (group B). Groups were comparable. One fracture was open.ResultsFor the Group A, 14 patients had a follow up of 35.3xa0months and for the Group B, 16 patients had a follow up of 27xa0months. Mobility was comparable in both groups. The Hospital for Special Surgery (HSS) score was 86.4 versus 80.6, the Lysholm score was 83.6 versus 77 for groups A and B respectively. Consolidation was 3.25xa0months versus 3.35xa0months and mean axis was 183.1° versus 181.6° for groups A and B. Mechanical axes during revision were statistically different to the controlateral axes. One secondary displacement was noted in group A and one secondary displacement in group B. Group A had eight patients reporting discomfort with the material versus three in group B (pu2009<u20090.05).ConclusionThe hypothesis is proven. In regards to the results, there is no significant difference between the two groups but the clinical tolerance was better in group B. More time is needed in the long term to better evaluate these severe fractures.

Value of the cumulative sum test for the assessment of a learning curve: Application to the introduction of patient-specific instrumentation for total knee arthroplasty in an academic department

BACKGROUNDnThe purpose of the study was to use the cumulative summation (CUSUM) test to assess the learning curve during the introduction of a new surgical technique (patient-specific instrumentation) in total knee arthroplasty (TKA) in an academic department.nnnMETHODSnThe first 50TKAs operated on at an academic department using patient-specific templates (PSTs) were scheduled to enter the study. All patients had a preoperative computed tomography scan evaluation to plan bone resections. The PSTs were positioned intraoperatively according to the best-fit technique and their three-dimensional orientation was recorded by a navigation system. The position of the femur and tibia PST was compared to the planned position for four items for each component: coronal and sagittal orientation, medial and lateral height of resection. Items were summarized to obtain knee, femur and tibia PST scores, respectively. These scores were plotted according to chronological order and included in a CUSUM analysis. The tested hypothesis was that the PST process for TKA was immediately under control after its introduction.nnnRESULTSnCUSUM test showed that positioning of the PST significantly differed from the target throughout the study. There was a significant difference between all scores and the maximal score. No case obtained the maximal score of eight points. The study was interrupted after 20 cases because of this negative evaluation.nnnCONCLUSIONnThe CUSUM test is effective in monitoring the learning curve when introducing a new surgical procedure. Introducing PST for TKA in an academic department may be associated with a long-lasting learning curve. The study was registered on the clinical.gov website (Identifier NCT02429245).