Reconstruction of bone defects with impacted allograft in femoral stem revision surgery.

A retrospective clinical review was done on 54 revision hip patients. Radiological analysis examined the Gross and AAOS classifications, stem position, cement mantles, allograft and evolution (subsidence, resorption and remodelling). The Harris Hip score was used for clinical assessment. We used bone bank allograft and a polished non-collared stem LD. The follow-up period was 60.5 months (19.4-152.4), and the average age 68.5 (range: 22-85). There were 21 females and 33 males. The surgical approach was: lateral (5.56%) posterior (91.4%); trochanteric osteotomy: 25.9%; associated acetabular revision: 59.3%; previous operations: 1.9. The preoperative Harris score was 35 (28-40) and rose to 81 (50-99) postoperatively. The stem alignment was neutral (44.44%), varus (38.89%) and valgus (16.67%). The femur/stem diameter relationship was 1.8 (1.2-2.7). There were no changes in stem alignment in 94.4%. An adequate cement mantle was: proximal zone (61.1%), medium zone (27.8%) and distal zone (16.7%). The rate of any subsidence was 38.9% (progressive: 12.96%). The rate of complications was 40.7% and included periprosthetic fracture: 14.8%; superficial infection: 1.9%; deep late infection: 1.9%; dislocation: 3.7%; heterotopic ossification: 13%. The rate of new stem revision was 16.6%. The clinical and radiological success rate was 77.78%. A greater incidence of revisions has been found in stem malalignment, progressive subsidence, a Harris increase of <20 points, allograft resorption, small diameter stems and inadequate cement mantle. We recommend hard impaction and a cement mantle of at least 2 mm. Non-progressive subsidence does not increase stem loosening. The technique has been useful in recovering bone stock in a severely defective femur and achieves a stable reconstruction. The level of evidence was therapeutic study level III-2 (retrospective cohort study; see the instructions to the authors for a complete description of the levels of evidence).