Page 151 - Reconstructive Techniques in Musculoskeletal Tumor Surgery

Discussion
Osteoarticular allografts represent an alternative to endoprosthetic reconstruction in musculoskeletal tumor surgery. However, solid evidence on the incidence of complications, failure mechanisms, and survival of the reconstruction is lacking. We therefore systematically reviewed the literature and retrospectively evaluated our single-centre experiences, with the aims to assess long-term rates of complications, mechanisms of failure, and rates of survival of the allograft.
Table III. Analysis of reported complication rates by odds ratios (OR) with 95% con dence intervals (CI)
Osteoarticular allografts
Infection
n (%) OR p-value (95% CI)
Location (n)
Distal femur (184)
Proximal tibia (104)
Distal radius (99)
n (%)
55 (30) 47 (35) 11 (11)
Failure
OR p-value (95% CI)
Ref (-) -
1.2 0.38 (0.8 – 2.0)
0.3 0.001 (0.1 – 0.6)
n (%)
21 (11)
32 (24)
14 (14)
Fracture
OR (95% CI)
Ref (-)
2.2 (1.3 – 4.4)
1.3 (0.6 – 2.6)
p-value
- 0.005 0.51 <0.00001
Data in this table are based on results reported in papers focusing on one reconstruction site exclusively. Results are derived from three papers focusing on the distal femur14, 16, 19, ve on the proximal tibia15, 17, 43, 47, 53, seven on the distal radius22, 38, 40, 41, 48-50 and ve on the proximal humerus21, 23, 24, 45, 46.
* logistic regression analysis. Ref, reference value.
The reconstruction failed in 53% of our patients, mostly due to mechanical complications. Previous studies reported failures in 22% to 60% of segmental osteoarticular allografts; however, follow-up varied greatly (see supplementary material). Previous authors have stated that if an intercalary allograft survives the critical three to four years, it is likely to last for many years12. It appears that this does not apply to osteoarticular grafts. Of the grafts that were followed for more than ve years, 33% failed at a later point in time. One explanation might be that creeping substitution, the process through which the allograft is gradually replaced by living bone29, cannot take place at the articular side of the osteoarticular graft and as a result, there is a risk of subchondral collapse42. If technically feasible, performing a unicondylar or hemicortical resection may prove useful in reducing this risk; by preserving host subchondral bone and increasing the contact surface between allogenic and host bone, the risk of collapse and nonunion may be reduced. In the
17 (9) 25 (18) 1 (1)
Ref (-) -
2.2 0.02 (1.1 – 4.3)
0.1 0.03 (0.0 – 0.8)
33 (35)
humerus (0.6 – 1.7 (0.4 – 2.4) (2.2 – 7.7) 7
Proximal (95)
28 (30)
1.0 0.94
9 (10)
1.0 0.95
4.1
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