Three-dimensional finite element analysis with different internal fixation methods through the anterior approach.

BACKGROUND: With the modernization of society and transportation in the last decades in China, the incidence of high-energy trauma increased sharply in China, including that of acetabular fractures. AIM: To establish different finite element models for acetabular posterior column fractures involving the quadrilateral area of the acetabulum. METHODS: The three-dimensional models of the normal and fractured pelvis and the five internal fixations were established using the computed tomography data of the pelvis of a living volunteer. After the vertebral body model was inserted in the way of origin matching and all cancellous bones were copied using the duplicated cancellous bone model as the subtractive entity, the Boolean operation was performed on the pelvis model to obtain the model of the complete pelvis cortical and cancellous bones. RESULTS: In the standing position, the maximum stress was 46.21 MPa. In the sitting position, the sacrum bore the simulated gravity load at the upper end. When comparing the five fixations, there were no significant differences in the stress mean values among groups (sitting: P = 0.9794; standing: P = 0.9741). In terms of displacement, the average displacement of the internal iliac plate group was smaller than that of the spring plate group (P = 0.002), and no differences were observed between the other pairs of groups (all P > 0.05). In the standing position, there were no significant differences in the mean value of displacement among the groups (P = 0.2985). It can be seen from the stress nephogram of the internal fixations in different positions that the stress of the internal fixation was mainly concentrated in the fracture segment. CONCLUSION: There were no significant differences among the fixations for acetabular posterior column fractures involving the quadrilateral area of the acetabulum.

Clinical characteristics and surgical treatment of haemophilic pseudotumor: A retrospective analysis of thirty-four patients.

AIMS: Haemophilic pseudotumor (HPT) is a rare but challenging complication of haemophilia. This study was intended to provide our experience about clinical characteristics and surgical treatment of HPT. METHODS: Clinical medical records were retrieved from the Hemophilia Center, Nanfang Hospital, to identify the patients who had been surgically treated from 1 January 2006 to 31 December 2017 with a definite diagnosis of HPT. Their clinical features, surgical management, outcomes and complications after surgery were analysed. RESULTS: We identified 34 patients with HPT who had surgical treatment over a 12-year period and five of them had multiple HPTs. The incidence of HPT at this centre was 2.3% over the dozen years. A previous trauma leading to the development of HPT was reported in 18 cases (52.9%). The HPT affected only soft tissue in 7 patients, bone and soft tissue in 25 ones and joint in 2 ones. Preoperative infection and fistula formation happened in ten patients, two of whom were related to abdominal HPTs. Enterococcus faecalis was cultured in five cases with fistula formation. HPT associated with pathological fracture was observed in five cases, two of whom were treated by external fixation and 3 by HPT resection and metallic internal fixation. Amputation was performed for nine patients, 6 of whom had preoperative infection and fistula formation. Their follow-up duration averaged 4.2 ± 2.9 years (range, from 1 to 13.5 years) after surgery. Of all our cases, three suffered from postoperative infection, five from recurrence of HPT and two with external fixation from fracture non-union. CONCLUSIONS: HPT patients with preoperative infection had worse prognosis than those without. Surgical treatment plus intensive replacement therapy was effective for HPT but with a high rate of complications. HPT resection and metallic internal fixation rather than external fixation should be recommended for HPT patients with pathological fracture.

Clinical Characteristics and Distribution of Thumb Polydactyly in South China: A Retrospective Analysis of 483 Hands.

PURPOSE: This study was intended to characterize the epidemiological features of thumb polydactyly (TP) in South China. METHODS: Clinical records were retrieved from 1 central hospital in South China to identify the patients with a definite diagnosis of TP from January 2004 to January 2017. The cases were classified by their x-ray appearance. The data collected included sex, age at first operation, reoperation, family history, unilateral/bilateral polydactyly, right/left hand involvement in unilateral cases, classification of polydactyly, and the presence of associated congenital anomalies. RESULTS: A total of 428 patients with a definite diagnosis of TP were identified (278 males and 150 females) involving 483 cases, 373 unilateral and 55 bilateral. A syndrome or associated congenital anomaly was found in 26 (18 unilateral and 8 bilateral cases). A dominant thumb, larger and more developed, was observed in 448 hands (93%), and was the ulnar thumb in 433. Owing to postoperative complications, 31 thumbs (6.4%) underwent reoperation. The average interval from initial surgery to reoperation was 4.8 years. CONCLUSIONS: Thumb polydactyly had a male predominance in this Chinese cohort, mostly occurring on the right hand with an ulnar dominant thumb. Bilateral cases had a higher incidence of associated anomaly and positive family history than unilateral cases. The need for additional surgery for TP might occur as late as 4.8 years after primary surgery. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Osteochondroma: Review of 431 patients from one medical institution in South China.

BACKGROUND: The geographic distribution of osteochondroma (OC) varies greatly around the world. There has been no recent report on OC in a large Chinese population. The aim of this study was to characterize OC by an epidemiological analysis of the clinical data from one medical institution in South China. METHODS: We searched medical electronic records from January 2001 to January 2016 in one large hospital in South China to identify patients with a definite diagnosis of OC. Their epidemiological data were collected and analyzed statistically, including gender, tumor site, age at first diagnosis and symptoms, local recurrence and malignant transformation. Differences between genders and between solitary osteochondroma (SO) and multiple osteochondroma (MO) were particularly analyzed. RESULTS: A total of 431 OC patients (291 males and 140 females; 329 SOs and 102 MOs) were identified. The gender ratio was 2.08 with a male predominance. OCs were mostly located around the knee (250 cases). 280 patients were in their 0s to 20s upon first diagnosis. The average age at the time of first diagnosis was 20.63 years for all, 18.47 years for males and 25.11 years for females (P=0.000). OC recurred locally in 35 patients (15 SOs and 20 MOs), with a significant difference between SO/MO (P=0.000) but not between genders (P=0.100). The average interval from the primary surgery to local or malignant recurrence was 37.41 months. Malignant transformation was found in 5 patients (4 males and 1 female), showing no gender difference (P=0.549). CONCLUSIONS: OC may have a male predominance in Chinese population. It mostly occurred at 0-20 years of age and around the knee. Upon the first diagnosis of OC, the males tended to be younger than the females, and so did the MO patients than the SO ones. In addition, MO had a higher incidence of local recurrence. Intervals from primary surgery to local recurrence or malignant transformation in MO patients were longer than in SO patients.

Masquelet technique versus Ilizarov bone transport for reconstruction of lower extremity bone defects following posttraumatic osteomyelitis.

OBJECTIVE: This study was to compare the effectiveness of Masquelet technique versus Ilizarov bone transport in the treatment of lower extremity bone defects following posttraumatic osteomyelitis. PATIENTS AND METHODS: We retrospectively reviewed 39 patients who had been treated at our department for lower extremity bone defects following posttraumatic osteomyelitis. They were 30 males and 9 females with a mean age of 39.18 (range, 12-63 years). The infected bone defects involved 26 tibias and 13 femurs. The mean length of the bone defects after radical debridement was 6.76cm (range, 2.7-15.7cm). Masquelet technique (MT, group A) was used in 20 patients and Ilizarov bone transport (IBT, group B) in 19 ones. The measurements were bone outcomes (union, deformity, infection and leg-length discrepancy) and functional outcomes (significant limping, joint contracture, soft tissue dystrophy, pain and inactivity). RESULTS: The mean follow-up after removal of the apparatus was 25.26 months (range, 14-51 months). The mean finite fixator time was 10.15 months (range, 8-14 months) in group A versus 17.21 months (range, 11-24 months) in group B. The bone outcomes were similar between groups A and B [excellent (5 vs. 7), good (10 vs.9), fair (4 vs. 2) and poor (1 vs. 1)]; group A showed better functional outcomes than group B [excellent (8 vs. 3), good (9 vs. 6), fair (3 vs. 8) and poor (0 vs. 2)]. CONCLUSIONS: In the treatment of segmental lower extremity bone defects following posttraumatic osteomyelitis, both IBT and MT can lead to satisfactory bone results while MT had better functional results, especially in femoral cases. IBT should be preferred in cases of limb deformity and MT may be a better choice in cases of periarticular bone defects.

Designation and Validation of a Posterior Anatomical Plate for the Anterior Column of the Acetabulum.

BACKGROUND Surgical treatment of acetabular fractures is one of the greatest challenges for orthopedic surgeons. Fixation of most displaced fractures requires extensive exposure, which may lead to complications, including blood loss, neural or vascular injury, postoperative infection, wound healing problems, and heterotopic bone formation. MATERIAL AND METHODS This study was conducted to certify an anatomic plate with an anterior column lag screw guiding device to repair the posterior acetabulum. Complete pelvic spiral computed tomography (CT) scan data were collected from 56 patients. The posterior column of the acetabulum was simulated with a lag screw. The guiding device for the plate was designed by measuring the position of the screw point and the direction and maximum diameter of the screw. RESULTS The distance from the screw point to the apex of the greater sciatic notch was farther in women than in men. The distance from the screw point to the ischial spine was also farther in women than in men. The q angle (front inclination angle) of the screw was lower in women than in men. The j angle (camber screw angle) was greater in women than in men. The success rate when using the guided device was significantly higher than when using traditional pedicle screws. CONCLUSIONS The guided device was very useful for improving placement success and accuracy rates of the acetabular posterior anatomical anterior column plate using antegrade lag screws, and for reducing surgical risk and injury.

Anterograde Fixation Module for Posterior Acetabular Column Fracture: Computer-Assisted Determination of Optimal Entry Point, Angle, and Length for Screw Insertion.

BACKGROUND The aim of this study was to provide valid data for a plate-screw fixation model for fractured posterior-anterior columns of the acetabulum. MATERIAL AND METHODS Nineteen cadaveric bony hemi-pelvis specimens were obtained and 50 healthy adults were enrolled. The modified Stoppa approach and computed tomography (CT) imaging were used to collect the measured parameter data of the module. RESULTS The measured parameter data were as follows: OP, 0.96±0.32 cm in females and 0.92±0.16 cm in males (P>0.05); PI, 0.98±0.28 cm in females, and 0.75±0.23 cm in males (P>0.05); ÐÏ´, 59.68°±6.28° in females and 56.75°±3.22° in males (P>0.05); and Ðφ, 41.27°±2.76° in females and 34.31°±2.78° in males (P<0.05). The corresponding CT image data were as follows: PI, 1.08±0.22 cm in females and 0.85±0.27 cm in males (P>0.05); OP, 1.06±0.29 cm in females and 1.12±0.24 cm in males (P>0.05); ÐÏ´, 55.33°±4.00° in females and 55. 50°±3.43° in males (P>0.05); and Ðφ was 39.21°±2.45°in females and 35.58°±2.31°in males (P<0.05). No significant difference with respect to sex and side existed between specimens and healthy adults (P>0.05). CONCLUSIONS The measured parameter data obtained in healthy adults and cadaveric specimens provided an anatomic basis for the designation of the guide module, and thus confirmed the accuracy and safety of screw placement in fractured columns of the acetabulum.

Minimally invasive plate osteosynthesis of acetabular anterior column fractures using the two-incision minimally invasive approach and a preshaped three dimension plate.

PURPOSE: To investigate the treatment of acetabular anterior column fractures using a two-incision minimally invasive (TIMI) approach and minimally invasive plate osteosynthesis (MIPO) technique using a preshaped 3D plate. METHODS: A group of 12 consecutive cases of acetabular fractures from March 2013 to July 2014 were treated with the TIMI approach. 3D mirror models of the uninjured side of the hemipelvis were printed preoperatively; the plates used in surgery were preshaped according to these models. MIPO surgical techniques were applied. All patients had a minimum one year radiographic and clinical follow-up. RESULTS: Seven fractures involved the anterior column, four were anterior column with posterior hemitransverse, and one was anterior column with the pubic symphysis. The average surgery time was 200 minutes, and mean blood loss was 1004 ml. The fracture reduction results as assessed by Matta radiographic outcome scores were good in eight, satisfactory in three, and poor in one patient. Functional outcomes according to the Harris hip scores were excellent for seven, good for three, and fair for two. Post-operative complications included incomplete femoral nerve damage and abdominal cavity injury. CONCLUSIONS: The TIMI approach is an alternative to the ilioinguinal approach for anterior column acetabular fracture treatment, especially for fractures involving the dome and quadrilateral plate that are feasible for application of MIPO techniques. The technique of preshaping the 3D plate makes the plate better accommodated to the fracture surface and easier to apply in MIPO procedures. All dissection was between the anatomical interval, which allowed less soft tissue injury and related complications, and caused less bleeding. The fracture types in our case series were relatively simple, and follow-up time was short; more clinical trials are necessary for evaluation of middle- and late-term results.