Page 152 - Reconstructive Techniques in Musculoskeletal Tumor Surgery

Chapter 7
only study focusing on unicondylar osteoarticular allografts to date, Muscolo et al9 reported promising results with an allograft rate of survival of 85% at ten years in 40 reconstructions (38 patients).
Severe instability occurred in two reconstructions of the distal radius, and 63% of our patients with a reconstruction around the knee had to wear a brace for a prolonged period. Previously reported rates of instability range from 5% to 20%. Due to the subjectivity of the outcome, it is di cult to assess adequately the occurrence of joint instability in a retrospective study.
From our review, it appeared that fracture is the most common complication after osteoarticular allograft reconstruction (up to 52%). A total of ten of our patients (26%) sustained a fracture. The risk of fracture was higher after nail xation; in accordance with previous studies, we recommend plate xation3, 11, 56. One of the problems in osteoarticular reconstructions, however, is the fact that it is not possible to apply bridging osteosynthesis, while it has been noted that this reduces the risk of complications3, 57. An explanation for the high risk of fracture might be that considerable torsional forces act on the plate (especially in case of instability of surrounding joints) and the hardware is therefore prone to break at some point in time. We demonstrated that the proximal humerus and tibia have the highest risk of fracturing. The high risk for proximal humeral grafts might be explained by the greater length of these reconstructions. Although we could not demonstrate an association between graft length and the risk of complications, previous studies reported unfavorable results for larger reconstructions3, 13, 58. Filling the graft with cement may reduce the fracture rate in high-risk reconstructions24. Another strategy is to apply double-plate xation, thereby increasing the torsional and bending sti ness of the construct59. However, this may necessitate additional soft-tissue dissection and thus increase the risk of infection58.
A total of three of our patients (8%) underwent revision for symptomatic degenerative joint changes. Previous authors reported degenerative changes in 13% to 31% of reconstructed joints17, 19, 25, while others concluded that osteoarthritis occurs in practically all patients20, 40, 41. However, follow-up periods di ered and authors often either did not provide a clear de nition of degeneration14, 19, 25, 54 or su ced with a radiographic diagnosis9, 16, 17, 44.
The use of massive allografts is presumed to be associated with a high risk of infection60. However, through our literature review, we found an overall infection rate of 10% (52/514), which is identical to the rate found by Racano et al61 in their systematic review on endoprosthetic reconstruction in long-bone tumor surgery
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