Revision Total Knee Arthroplasty using Femoral Head Allograft

PURPOSE: We evaluate the results of allograft using femoral head in revision total knee arthroplasty with severe bone defects. MATERIALS AND METHODS: Between March 2000 and February 2005, the clinical records on 22 cases that had undergone the revision total knee arthroplasty using femoral head allograft were reviewed. Mean follow up period was 48(24~80) months. Allografts were used at proximal tibia in 12 cases, distal femur in 7 cases, both in 3 cases. We used posterior cruciate ligamental substituting component with extension rod in all cases. The clinical results were assessed with the knee score and functional score of Knee Society Knee Score(KSS), complication, union of allograft and so forth. We evaluated complications and union of the allograft. RESULTS: Mean degrees of preoperative and postoperative range of motion were 94+/-14 and 105+/-12 respectively. Postoperative mean knee score of KSS was increased from 45+/-10 to 79+/-8, and functional score was increased from 42+/-13 to 83+/-9. Union of allograft were observed in all cases. There were no infection, absorption and fracture of allograft. CONCLUSION: We consider allograft using femoral head in revision total knee arthroplasty with severe bone defects is one of the useful method.

Use of Femoral Head Allograft for Severe Bone Defect in Primary Total Knee Arthroplasty and Revision Total Knee Arthroplasty

PURPOSE: To investigate the clinical and radiological results after primary or revision total knee arthroplasty using fresh frozen femoral head strut allograft for severe bone defect. SUBJECTS AND METHODS: Seventeen patients (18 cases) with severe bone defect were taken primary or revision TKA from 1997 to 2001 using fresh frozen femoral head allograft. 12 cases of revision TKA and 6 of primary TKA were conducted. The average age was 66 years old(55~74) and the follow up period was 29 months(12~63 months). Bone defects were found at proximal tibia in 10 cases, distal femur in 2 and both sites in 6 cases. PCL substituting TKA with extension rod were 15, and PCL retaining TKA were 3. The clinical result was assessed with the knee score of Hospital for Special Surgery(HSS) and for assessment of allograft, simple X-ray film was employed. RESULTS: Average range of motion was increased from 71 degrees to 103 degrees and HSS score was increased from 46(18 ~68) to 83(68 ~91). With 17 of 18 femoral head strut allograft, union was seen and no clinical collapse was present. In one, partial allograft absorption was occured. The preoperative alignment was an average of 7 degrees varus(range 5 degrees~15 degrees) and postoperative alignment was averaged 6.1 degrees valgus(range 3 degrees ~7 degrees). No radiolucent lines were 2 mm or more in width, and there was no case of infection or fracture of allograft. CONCLUSIONS: Femoral head strut allograft was a satisfactory method of managing severe bone defect in primary or revision TKA.

Revision Total Knee Arthroplasty of Failed Unicompartmental Knee Arthroplasty

PURPOSE: To analyze the failure mechanism, complexity of surgery, complication and outcome of revision of failed unicompartmental knee arthroplasty(UKA). MATERIALS AND METHODS: 14 patients(16 knees) were followed up a mean 70 months. The patients were a mean age of 58.2 years at time of UKA and predominantly female(85%). Revision surgery was done 14 to 104 months with an average time of 4 years 10 months after UKA. The UKA component that were revised include 10 Microloc, 4 Allegretto, 1 Oxford and 1 Marmor modular II. Clinical and radiographic evaluation were completed preoperatively and at last follow-up. The scoring system used in this study is Hospital for Special Surgery(HSS) knee score. Radiographic assessment was performed using Bauer's method(tibio-femoral angle) and American knee society roentgenographic evaluation system. RESULTS: The predominant failure mechanism was polyethylene wear and femoral component loosening. At the last follow-up, the average HSS knee score significantly improved from 60 to 86. Average tibio-femoral angle was corrected from varus 2o to valgus 5o. The implant type used for the revision was PFC-PS. 11 knees required local autograft but no allograft were used. Femoral block augment and tibial metal wedges with stem were also used to reconstruct the defect. There were 2 cases of complications, subluxation of patella and deep infection after intraarticular injection at local clinic. CONCLUSION: Polyethylene wear and femoral component loosening was common failure mechanism in revision of UKA. Bone defects needed to reconstruct were detected in 11 cases but autograft was enough to reconstruct the defect. Result of failed UKA compares favorably with those of total knee revision.

Use of Structureal Allograft in Revision Total Knee Arthroplasty

PURPOSE: To analyze the clinical and radiological results after revision total knee arthroplasty(TKA) using structural allograft for severe bone defect, MATERIALS AND METHODS: Between l992 and 1997, we used structural allograft for revision TKA in 20 knees of 18 patients with severe bone defect, The average age at surgery was of 61.6 years. The follow-up period averaged 43 months(range, 1 3-80 months). All patients had severe bone defect of the femur and/or tibia. Ten distal femur and thirteen proximal tibia required allografting. Fresh frozen femoral heads were used in all patients. We used posterior stabilized stemmed PFC knee component in all cases except one case with constrained condylar type. Patients were evaluated with physical examination, radiographs and the Hospital for Special Surgery knee rating scale. RESULTS: Average range of motion before surgery was 87degrees and after surgery 107degrees. Average knee score was 65 before and 90.4 after surgery. Preoperative alignment averaged 1.8degrees valgus, ranging from 17degrees varus to 13degrees valgus, and postoperative alignment averaged 7,2 degrees velgus, ranging from 3degrees valgus to 10 val-gus, All patient improved pain and stability. Postoperatively average HSS score improved from 65(rang- ing from 46 to 92) to 90.4(ranging from 75 to 100). All of the allografts united with host bone. There was no radiolucent line, lysis, fracture and infection. CONCLUSION: Structural allograft can be a satisfactory method of managing large bone defects in the failed total knee arthroplasty.

Stemmed Prosthesis in Revision TKA / 대한정형외과학회잡지

PURPOSE: To analyze functional and radiological results after revision TKA using stemmed prosthesis in patients with severe bone defects. MATERIAL AND METHODS: From January 1990 to April 1997, 77 revision TKAs were performed in 67 patients by one surgeon. Fluted diaphyseal intramedullary stems were used in 31 cases with severe bone defects. Metal wedges, augments and bone grafts were used to fill osseous defects when necessary. The average interval between the index arthroplasties and the revision was 6 years and 2 months. The average duration of follow-up was 3 years and 1 month. The causes of revision TKAs included wear in 20 joints, infection in 5, aseptic loosening in 3, ankylosis in 2 and breakage of tibial component in one. RESULTS: The average preoperative knee score, according to the rating scale of The Hospital for Special Surgery, was 63 points and improved to 90 points postoperatively. The average preoperative range of motion was 95 degrees and improved to 125 degrees postoperatively. Radiologically, two cases showed radiolucencies without progression at the interface between bone and cement. At the uncemented stem-to-bone interface, thin radiopaque line developed near the metal in 14 cases. All cases showed no subsidence of components or changes in alignment. CONCLUSION: This technique using a stemmed prosthesis was effective for revision total knee arthroplasty in patients with severe bone defect and instability.