Objective To investigate the effectiveness and biomechanical analysis of 3 fixation methods of screw anterior-posterior fixation (SAPF), screw posterior-anterior fixation (SPAF), and buttress plate fixation (BPF) in treatment of posterior Pilon fractures. Methods Fifteen fresh-frozen skeleto-ligamentous lower leg specimens were harvested to establish the models of posterior Pilon fracture, and then fracture was fixed with BPF (n=5), SAPF (n=5), and SPAF (n=5). Vertical force was loaded to internal fixation failure in a speed of 1 cm/minute with servohydraulic testing machine. The instantaneous loads of 1 mm and 2 mm steps and the failure modes were recorded. Between May 2008 and December 2011, 56 patients with posterior Pilon fracture were treated with SAPF (SAPF group) in 11 cases, or SPAF (SPAF group) in 26 cases, or BPF (BPF group) in 19 cases. There was no significant difference in age, gender, injury cause, side, disease duration, and complications among groups (P gt; 0.05). Clinical and radiographic examinations were used to assess the reduction and healing of fracture; the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score and the visual analogue scale (VAS) were used to evaluate the functional outcomes. Results No breaking or bending was observed in all specimens, fixation failure was caused by cancellous bone compression. The instantaneous loads of 1 mm and 2 mm steps were the largest in BPF group, larger in SPAF group, and smallest in SAPF group, showing significant differences among 3 groups (P lt; 0.05). A total of 47 cases were followed up 16-54 months (9 in SAPF group, 22 in SPAF group, and 16 in BPF group), with a mean time of 35.2 months. Fixation failure was found in 2 cases of SAPF group; the other cases obtain bony union within 3 to 4 months (mean, 3.2 months) with no fixation failure. The AOFAS score was significantly lower in SAPF group than in SPAF and BPF groups (P lt; 0.05), but no significant difference was found between SPAF and BPF groups (P gt; 0.05). The VAS score was significantly higher in SAPF group than in SPAF and BPF groups (P lt; 0.05), but no significant difference was found between SPAF and BPF groups (P gt; 0.05). Conclusion SAPF could not reach enough fixation strength for the posterior Pilon fracture; both SPAF and BPF could reach rigid fixation, and have good effectiveness. And from the biomechanical points, BPF could reach better fixation strength than screw fixations.
Objective To investigate the effectiveness of extreme lateral channel debridement and fusion combined with posterior fixation for lumbar spinal tuberculosis. Methods A retrospective analysis was made on the clinical data of 17 patients with lumbar spinal tuberculosis undergoing extreme lateral channel debridement and fusion combined with posterior fixation between December 2008 and December 2014. There were 10 males and 7 females, aged 20-69 years (mean, 42.6 years). The disease duration was 1-6 months (mean, 3.4 months). The involved segments included L1, 2 in 5 patients, L2, 3 in 6 patients, L3, 4 in 3 patients, and L4, 5 in 3 patients. Based on American Spinal Injury Association (ASIA) classification, there were 2 cases of grade C, 13 cases of grade D, and 2 cases of grade E. The visual analogue scale (VAS) score, Japanese Orthopaedic Association (JOA) score, and Barthel index were used to evaluate the effectiveness, and the improvement rate of JOA score and Barthel index was calculated at the same time. Lumbar X-ray film and CT were taken regularly to evaluate lumbar kyphotic Cobb angle correction and bony fusion. Results The operation was successfully performed in 17 patients, and pathological examination showed tuberculosis. All cases were followed up 24-48 months (mean, 35.3 months). Lumbar X-ray film and CT showed that necrotic bone and abscess were cleared completely, and lumbar kyphosis correction was satisfactorily in all cases. Bony fusion was achieved within 6 months, and clinical cure was obtained within 18 months in all cases; no recurrence was found during follow-up period. No loosening or breakage of internal fixation was observed. At last follow-up, ASIA classification was recovered to grade D and grade E from grade C in 2 cases, to grade E from grade D in 11 cases and had no change in 2 cases (grade D). Two cases of ASIA grade E showed no neurological deficit. The VAS score, JOA score, Barthel index, and lumbar kyphotic Cobb angle were significantly improved at 2 weeks after operation and at last follow-up when compared with preoperative ones (P<0.05). At last follow-up, the improvement rate of JOA score was 75.2%±6.2% and the improvement rate of Barthel index was 75.7%±10.8%. Conclusion To use extreme lateral channel debridement and fusion combined with posterior fixation is an effective treatment for lumbar spinal tuberculosis.