Rodolfo Pusso

Vancomycin-supplemented impacted bone allografts in infected hip arthroplasty. Two-stage revision results.

Bone allografts can store and release high levels of vancomycin. We present our results of a two-stage treatment for infected hip arthroplasty with acetabular and femoral impaction grafting using vancomycin-loaded allografts. We treated 29 patients (30 hips) by removal of the implants, meticulous debridement, parenteral antibiotic therapy and second-stage reconstruction using vancomycin-supplemented impacted bone allografts and a standard, cemented Charnley femoral component. The mean follow-up was 32.4 months (24 to 60). Infection control was obtained in 29 cases (re-infection rate of 3.3%; 95% confidence interval 0.08 to 17) without evidence of progressive radiolucent lines, demarcation or graft resorption. One patient had a further infection ten months after revision caused by a different pathogen. Associated post-operative complications were one traumatic periprosthetic fracture at 14 months, a single dislocation in two hips and four displacements of the greater trochanter. Vancomycin-supplemented allografts restored bone stock and provided sound fixation with a low incidence of further infection.

Revision of the femoral prosthesis with impaction allografting and a Charnley stem A 2- TO 12-YEAR FOLLOW-UP

Impacted morcellised bone allograft and a Charnley stem was used to revise 59 loose femoral components in 57 consecutive patients. Femoral bone loss was rated as Endo-Klinik grade 2 in nine patients, grade 3 in 41, and grade 4 in nine. The immediate postoperative radiographs and those taken at the most recent follow-up were compared for radiolucencies, subsidence and incorporation of the graft. One patient was lost to follow-up and two were not available for radiological analysis. The mean clinical follow-up in 58 procedures was 56.7 months (24 to 144) and the mean radiological review of 56 reconstructions was 54.4 months (24 to 144). An intraoperative femoral fracture occurred in one patient (1.7%) and was successfully treated by strut grafting and cerclage wiring. Extrusion of cement through perforations or incomplete hoop fractures was detected in the postoperative radiographs of ten procedures (17%); none of these patients sustained a complete fracture. Three patients had dislocations (5%) and two (3.5%) developed painful subsidence of the stem which required a further revision. The latest follow-up radiographs in 56 reconstructions showed a well fixed stem and radiological healing of the graft in 52 (93%), and definite loosening in four (7%). Of these four, two were revised again and two were asymptomatic after a follow-up of 120 months each. The mean subsidence in the 52 successful revisions was 0.38 mm (0 to 4). Impaction allografting with a Charnley stem restored bone stock and provided adequate fixation of the stem in 93% of the hips. There was a low rate of rerevision (3.5%) and a low incidence of intraoperative and postoperative complications.

Subsidence Pattern of Charnley Cemented Femoral Revisions with Impacted Morcelised Bone After a Follow-up of Two to Twelve Years

We quantified the subsidence in 56 of 59 consecutive Charnley femoral revisions with impacted morcelised bone, after 57 months of follow-up (range 48–144). Subsidence was measured on AP radiographs obtained at regular intervals. Subsidence was analysed together with the development of radiographic loosening or need for re-revision subsidence. During the first two years it was compared with that of 50 Charnley primary arthroplasties. In forty-five revisions no subsidence was detected, and 11 had subsided an average of 6 millimeters (range 2–20). Among 52 successful revisions, 45 had no subsidence detected and 7 subsided less than 5 millimeters (average 2.42; range 2–4). All 4 failed revisions subsided (average: 12 millimeters; range 2–20). The difference between successful and failed revisions was significant (p=0.009). At 2 years of follow-up, 9 revisions and 2 primary arthroplasties had subsidence detected (p=0.14). Subsidence detected after the second year was observed in all failed revisions and in only one successful. Subsidence in successful Charnley revisions is restricted to less than 5 millimeters and occurs during the first two postoperative years. The different subsidence pattern between revision and primary arthroplasties suggests that limited subsidence of the grafts occurs, predominantly during the first two years.