Autologous bone cylinder transplantation with cannulated screw re-stabilisation: a new treatment option for delayed fracture healing of the femoral neck.

AIM: Delayed fracture healing and non-unions of the femoral neck after lag screw osteosynthesis occur particularly in multiply injured young patients, and then surgical revision is often required. Currently no evidence-based treatment guidelines exist and therapeutic options include both hip arthroplasties and femoral head-maintaining operations. Here we report on young patients with delayed fracture healing of the femoral neck. Patients underwent revision surgery by autologous bone cylinder transplantation with mechanical re-stabilisation by cannulated lag screws. MATERIAL AND METHODS: We reviewed all patients after femoral neck screw osteosynthesis and identified eight patients at 7.3 [3-24] months after initial osteosynthesis with persisting, or reoccurring postoperative pain. Average patient age was 43 [35-57] years and patient Harris Hip Score (HHS) numbers were low (52 ± 19). Before revision surgery the preoperative CT scans showed a partial bone consolidation (anterior and/or posterior cortices) in the absence of a complete bone consolidation of all cortices. Seven patients were treated by bone cylinder transplantation from the patient's own iliac crest; one patient underwent an inverse bone cylinder procedure. Seven patients were additionally treated by re-insertion of 1-2 lag screws to increase mechanical stability. RESULTS: After revision surgery the average patient follow-up period was 42 [12-89] months. Five patients achieved favourable clinical and radiographic outcome with both complete bone union and return to work within 7.2 ± 2.75 months. One patient showed fracture healing but developed an aseptic femoral head osteonecrosis. Two patients failed to achieve complete bone consolidation. The postoperative HHS was 92 ± 4 in patients with favourable clinical outcome (n = 5) and 89 ± 2 after second revision surgery (2 hip arthroplasties; 1 valgus osteotomy). Both groups had significantly better HHS numbers compared with before surgical revision (p < 0.05). DISCUSSION: These data show that in this difficult-to-treat subset of young patients with delayed fracture healing of the femoral neck, autologous bone cylinder transplantation with mechanical re-stabilisation should be considered as a promising surgical revision strategy before hip arthroplasty.

Evaluation of a simplified dual-platform flow cytometric method for measurement of lymphocyte subsets and T-cell maturation phenotypes in the population of Nouna, Burkina Faso.

In the context of a larger clinical study in Nouna, Burkina Faso, we evaluated a simplified dual-platform (DP) flow cytometric (FCM) method that allows the determination of major lymphocyte subsets in a single test tube. We compared the phenotyping of lymphocytes with DP FCM and simultaneous measurements with standard single-platform (SP) FCM for samples from 177 individuals. Analysis of the comparative measurements revealed that DP FCM systematically underestimates the proportion of NK cells, overestimates the percentage of CD3(+) CD8(+) lymphocytes, and yields proportions of B cells and CD4(+) T cells comparable with the results from SP FCM. Bland-Altman analysis showed a low bias between both methods and an acceptable precision for percent values of CD4(+) T cells (bias +/- precision, -1% +/- 6%) and CD8(+) T cells (-3% +/- 6%). The absolute cell numbers of all lymphocyte subpopulations, however, were systematically biased towards lower values being obtained by DP FCM. Reference values for the distribution of T-cell maturation phenotypes in 177 healthy adults were calculated using DP FCM. The mean +/- standard deviation (SD) CD4(+)-to-CD8(+) T-cell ratio was 1.61 +/- 0.61, the mean percentage +/- SD of CD4(+) T cells was 42% +/- 7%, and that of CD8(+) T cells 29% +/- 7%. Among CD4(+) lymphocytes, 28% +/- 7% were classified as central memory (CD45RA(low) CCR7(+)), 22% +/- 10% as naïve (CD45RA(high) CCR7(+)), 45% +/- 12% as effector memory (CD45RA(low) CCR7(-)); and 5% +/- 3% as terminally differentiated effector memory expressing CD45RA (CD45RA(high) CCR7(-)). Among CD8(bright) lymphocytes, 3% +/- 2% had a central memory phenotype, 27% +/- 13% were naïve, 37% +/- 13% had an effector memory phenotype, and 34% +/- 12% were terminally differentiated effector memory cells expressing CD45RA.