Revision total knee arthroplasty (TKA) is becoming increasingly common in the United States as the population ages and larger numbers of primary TKA are performed in younger individuals. Cemented or uncemented tibial stems are frequently used in revision cases. Decreased clinical outcomes and patient satisfaction have been described for revision TKA. This study aims to determine if the presence of overall pain and tibial pain at the end of the stem differs between cemented and uncemented tibial stems in revision TKA. This was a retrospective cohort study comparing patients who underwent revision TKA utilizing cemented or uncemented tibial stems in a 15-year period at a single institution with at least two-year follow-up. Exclusion criteria included age under 18, isolated revisions of the femoral component or polyethylene exchanges, lack of preoperative or postoperative imaging, insufficient operative or implant records available for electronic chart review, revision procedures performed at outside facilities, patients who were deceased at the time of survey administration, refusal to participate in the study, and failure to return the mailed survey or respond to a telephone follow-up questionnaire. Radiographic analysis included calculation of the percentage of the tibial canal filled with the implant, as well as measurement of the diameter of the tibial stem. Radiographs were also reviewed for evidence of cavitary defects, pedestal formation, radiolucent lines, and periprosthetic fractures. Mailed surveys addressing overall pain, tibial pain, and satisfaction were analyzed using Fisher's exact test and the independent sample t-test. Logistic regression was used to adjust for age, gender, and preoperative bone loss.Introduction
Methods
Computer aided surgery aims to improve surgical outcomes with image-based guidance. Navigated Freehand bone Cutting (NFC) takes this further by eliminating the need for cumbersome mechanical jigs. Multiple previous experiments on plastic and porcine bones, performed by surgeons with different level of expertise, suggested that the NFC technique was feasible. This study pushes NFC further by using the technique to perform complete total knee replacement (TKR) surgeries on cadavers (including implant cementing of tibia and femur). A single surgeon performed a series of TKR surgeries on full cadaveric legs. Cruciate sacrificing implants were selected because these were considered more challenging for a freehand cutting approach due to the extra number and complexity of the cuts needed around a posterior stabilizing post recess when present. A proprietary NFC prototype system was used, with real time graphics to indicate where/how to cut the bone without jigs. The system comprised a navigated smart oscillating saw, reciprocating saw and drill without any of the conventional jigs typically used in TKR. The tasks performed included (and were grouped) to include pre-surgical planning, incision, placement of navigation pins & markers on tibia and femur, bone registration, marking and cutting, cut surface digitization (for quality assessment), implant placement and cementing, assessment of implant fit and location, and pin removal and wound closing.Introduction
Materials and Methods
Computer aided surgery aims to improve surgical outcomes with image-based guidance. Navigated Freehand bone Cutting (NFC) takes this further by eliminating the need for cumbersome mechanical jigs. Multiple previous experiments on plastic and porcine bones, performed by surgeons with different level of expertise, suggested that the NFC technique was feasible. This study pushes NFC further by using the technique to perform complete total knee replacement (TKR) surgeries on cadavers (including implant cementing of tibia and femur). A single surgeon performed a series of TKR surgeries on full cadaveric legs. Cruciate sacrificing implants were selected because these were considered more challenging for a freehand cutting approach due to the extra number and complexity of the cuts needed around a posterior stabilizing post recess when present. A proprietary NFC prototype system was used, with real time graphics to indicate where/how to cut the bone without jigs. The system comprised a navigated smart oscillating saw, reciprocating saw and drill without any of the conventional jigs typically used in TKR. The tasks performed included (and were grouped) to include pre-surgical planning, incision, placement of navigation pins & markers on tibia and femur, bone registration, marking and cutting, cut surface digitization (for quality assessment), implant placement and cementing, assessment of implant fit and location, and pin removal and wound closing.Introduction
Materials and Methods
