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The literature article entitled ¿failure of the stem-condyle junction of a modular femoral stem in revision total knee arthroplasty¿ written by lian-arn lim, md, et al.Published in the journal of arthroplasty vol 16 no.1 (2001), was reviewed.Products used: total condylar iii (depuy).The purpose of this study was to report five cases of failure of the stem condyle unction of a modular femoral stem in revisions total knee arthroplasty.Revision of tka in the presence of poor bone stock often precludes the use of standard resurfacing implants.Implant fixation can be enhanced using medullary stems.Early component designs used nonmodular components.More recently, modular implants have become popular because they allow the surgeon to customize the prosthesis intraoperatively.Case one: a (b)(6) man underwent revision left tka in 1996 secondary to aseptic loosening.Because of marked segmental distal femoral bone loss, structural femoral head allografts were used to reconstruct the distal femur.A tc3 component with cemented stemmed femoral and tibial components was used.Two years after revision surgery, the patient developed pain, recurrent effusion and locking in the knee.Examination revealed decreased rom, joint crepitus and a large effusion.Radiographs showed bolt disassembly of the femoral component with the locking bolt lying within the joint (fig 1).The patient underwent re-revision of the femoral component.The distal end of the femoral component, including the entire condylar portion, was loose.The intercondylar locking bolt for the stem was free-floating in the joint.The proximal part of the stem remained well fixed in the femoral canal.A femoral allograft was placed onto the deficient femur and held with screws.A tc3 component was cemented into the allograft with secondary stem fixation.Three months after surgery, the patient had increased rom and no pain.Case two: a (b)(6) woman with ra underwent a tka secondary to distal femoral nonunion in 1996.The nonunion was taken down, reduced, and after adequate preparation bypassed with a cemented stemmed tc3 femoral component.Two years after surgery, the patient returned with a varus thrust at the knee.Examination confirmed marked mediolateral instability.Radiographs showed a persistent nonunion, angulation at the stem-condyle junction, and metal debris within the knee.The bolt was free-floating in the joint.The femoral cemented stem remained well fixed (fig 2).The patient was treated with a revision tka using a distal femoral allograft.**it does not specifically state that the bolt was revised, however it is reasonable to conclude that the bolt was replaced and the metal debris is related to the free-floating bolt--as the stem was well-fixed.Case three: a (b)(6) main underwent a cemented tka for post-traumatic arthritis in 1988.Two years later, he underwent revision of the tka secondary to aseptic loosening.The patient did well with this revision until 1993, when he was involved in a motor vehicle accident, sustaining an injury to the medial collateral ligament.He presented at the authors¿ clinic in 1995 with complaints of disabling left knee pain, aseptic loosening of the femoral component, and severe medial laxity.In 1995, the patient underwent re-revision.The patient was revised to a highly constrained tc3 prosthesis due to the mcl attenuation.Three years after the re-revision, the patient was doing well clinically.Two months after his three-year examination, the patient returned with knee pain, swelling, instability, and an inability to bear weight on the left lower extremity after a minor traumatic event.Examination revealed a left knee effusion and gross instability to varus-valgus stress.Radiographs showed fracture at the base of the femoral stem with disengagement of the intercondylar locking screw for the modular femoral stem.The prosthetic femoral stem was loose.The cemented femoral stem remained well fixed.At surgery, the tibial component was well-fixed and remained in place.The distal end of the femoral component was, including the entire condylar portion, was loose.The intercondylar locking bolt for the stem was free-floating in the joint.The proximal part of the stem was well fixed in its cement mantle and was removed with the help of an ultrasonic device.The patient had a large segmental femoral defect involving most of both femoral condyles.A distal femoral allograft was used to reconstruct the distal femur.The allograft-host bone interface was shaped and matched as closely as possible before the allograft-prosthesis composite was cemented into the femur with a 130x13 femoral stem.A 30 mm polyethylene component was impacted onto the tibial tray, and the knee was reduced.When last seen three years after re-revision surgery, the patient was pain-free with increase rom.Case four and five: a (b)(6) female presented to the clinic with bilateral infected tkas.She underwent bilateral resection tkas with staged reimplantation using tc3 components with cemented stems secondary to ligamentous laxity.One year after reimplantation, the patient returned with acute right knee pain.Examination revealed a severe varus deformity of the right and left knees.Radiographs showed failure of the stem-condyle junction of the right tc3 components with severe bone loss.Radiographs of the left knee component showed varus malalignment with a loose femoral component.The patient underwent bilateral resection tka¿s in the right knee, there was metallosis and synovitis, the femoral component was loose, and the femoral stem locking bolt was fractured.The stem was well fixed.In the left knee, there was similar metallosis and synovitis.The femoral component was loose distally with extensive segmental and cavitary bone loss medially.The femoral stem locking bolt was fractured.The femoral stem was well fixed.The patient underwent staged revisions in both knees using a rotating hinge prosthesis.*it is reasonable to conclude that the metallosis and synovitis can be attributed to the bolt as the stem was well-fixed.The five cases of failure at the stem-condyle junction all were associated with locking screw failure with dissociation of the stem from the condylar portion of the component.
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Depuy synthes is submitting this report pursuant to the provision of 21 cfr, part 803.The report may be based on the information which depuy synthes has not been able to investigate or verify prior to the required reporting date.This report does not reflect a conclusion by fda, depuy synthes or its employees that the report constitutes an admission that the device, depuy synthes, or its employees caused or contributed to the potential event described in this report.H10 additional narrative: corrected: h6.Product complaint # (b)(4).Investigation summary : no device associated with this report was received for examination.Visual examination of the x-ray images provided confirmed the reported event.A worldwide lot specific complaint database search, or device history record (dhr) review, was not possible because the required lot number was not provided.The information received will be retained for potential series investigations if triggered by trend analysis, post market surveillance, or other events within the quality system.Device history lot : null.Device history batch : null.Device history review : null.If information is obtained that was not available for the initial medwatch, a follow-up medwatch will be filed as appropriate.
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