Should early weightbearing be allowed after intramedullary fixation of trochanteric femur fractures? A finite element study.

BACKGROUND: This study aims to investigate the effects of early weightbearing after intramedullary fixation of trochanteric fractures. METHODS: Femurs with different types of trochanteric fractures were modeled according to AO/OTA classification. Fractures were ideally reduced with one mm gap between fragments and fixed with intramedullary nails. Forces were applied simulating single- (Body weight: 60 kg, joint reaction force: 1999.2 N, abductor muscle force:1558.8 N) and double-leg standing positions (Joint reaction force: 196 N). In another model, a 500 Nm rotational force was applied as a simulation of a fall. RESULTS: A higher level of stress was determined at the calcar femorale, the fracture site, the holes for the lag screws, and the hole for the proximal locking screw on the nail, the threadless parts of the lag screws, and the mid-portion of the nail. During the single-leg stance, up to 3 mm displacement was observed with the reverse oblique type of fractures. In the simulation of the fall, 1.5 mm displacement occurred at the fracture site. No displacement was measured at stabile and type 31A2 fracture models. In addition, higher levels of stress were measured at the body of the nail (up to 133 MPa), proximal screws (up to 133 MPa) and at the bone distal to the nail (up to 84.3 MPa), but all values were under the limit of the yield stress of the bone and the titanium. CONCLUSION: Full weightbearing after intramedullary fixation of trochanteric femur fractures may be allowed except in obese patients and patients with 31A3 type fractures according to the AO/OTA classification. The use of support is recommended in order to prevent complications. Implant removal can be discussed with patients after fracture union in order to prevent possible periprosthetic fractures.

The relationship between the ratio of interpedicular distance increase and the ratio of spinal canal compromise in thoracolumbar burst fractures.

BACKGROUND: The aim of the study was to investigate the relationship between the interpedicular distance increase ratio and the ratio of canal compromise in thoracolumbar burst fractures. METHODS: Thirty-one patients (18 male and 13 female) with an average age of 30.8 (14-57) who had been treated for thoraco-lumbar burst fractures in the Department of Orthopaedics and Traumatology were included in the study. The initial anteroposterior radiographs of the patients were used to calculate the increase ratio of interpedicular distance (both from medial-to-medial and from center-to-center). The area measurements from the computerized tomography or magnetic resonans images were used to calculate the canal compromise. The relationship between the increase ratio of interpedicular distance and the ratio of canal compromise was investigated by correlation and linear regression analysis. RESULTS: There was a 'very good' correlation between the from medial-to-medial and from center-to-center measurements of interpedicular distance (Pearson correlation coefficient: 0.89, p<0.001). The correlation between the ratio of canal compromise and from medial-to-medial and from center-to-center measurements of interpedicular distance was 'good' with Pearson correlation coef-ficients of 0.60 and 0.63, respectively (p<0.001). No statistically significant relationships were found between the fracture levels, types, neurologic status of the patients, and the increase ratio of interpedicular distance or the ratio of canal compromise. CONCLUSION: Depending on the correlation coefficients which were obtained in this study: To predict the canal compromise from the ratio of interpedicular distance increase is not a reliable method for all of the patients.

[Long-term results of total hip arthroplasty in patients with juvenile rheumatoid arthritis]. / Juvenil romatoid artrit hastaliginda total kalça artroplastisinin uzun dönem sonuçlari.

OBJECTIVES: We evaluated the long-term results of total hip arthroplasty (THA) in patients with juvenile rheumatoid arthritis (JRA). METHODS: The study included 37 hips of 23 patients (22 females, 1 male; mean age 22 years; range 17 to 30 years) who underwent THA for hip degeneration secondary to JRA. All arthroplasties were performed through an anterolateral approach by the same senior surgeon. The mean body surface of the patients was 1.5 m2 (range 1.1 to 1.7 m2) and the mean symptom duration to surgery was 12 years (range 7 to 16 years). Twenty-three hips received cemented, 14 hips received hybrid prostheses. In seven hips with an extremely narrow femoral medulla and shallow acetabulum, a CDH prosthesis was used. The hips were evaluated using the Harris hip score. Prosthetic loosening and displacement and heterotopic bone formation were assessed on follow-up radiographs. The mean follow-up period was 135 months (range 58 to 212 months). RESULTS: The mean Harris hip score increased from 27.2 (range 11 to 69) to 79.5 (range 37 to 87) postoperatively. At final follow-ups, all the patients were satisfied with the outcome and were able to walk without support. Three hips (8.1%; 3 patients) required revision. The overall Kaplan-Meier implant survival rate was 86.5%. There were no significant correlations between the Harris hip score and radiographic loosening and the presence of calcification around the prosthesis. Heterotopic bone formation of grade I was observed in 17 hips (46%). CONCLUSION: Even though it is performed at young ages, THA considerably improves quality of life of patients with JRA having hip joint involvement and has a comparable implant survival.

Open reduction technique for overlapping and locked pubic symphysis.

A locked pubic symphysis can occur following a lateral compression injury of the pelvic ring when one pubic bone becomes entrapped behind the contralateral pubis or obturator foramen. In selecting the treatment modality, it is important to know the mechanism of injury. We presented the use of an open reduction technique in the treatment of a locked pubic symphysis in which open reduction external fixation application failed in the emergency department.

A two-portal posterior endoscopic approach in the treatment of a complex talus fracture: a case report.

The two-portal hindfoot endoscopy is a relatively new technique that is becoming increasingly popular. It gives excellent access to the posterior ankle compartment, the subtalar joint, and extra-articular structures. We report a 24-year-old man with a complex talus fracture involving the posterior part of the talar body and posterolateral process. He was treated endoscopically, with a two-portal posterior approach to the hindfoot. This approach allowed a better visualization and treatment of accompanying pathologies. Combined excision of the posterolateral process and fixation of the fracture was performed with the two-portal hindfoot endoscopy, which has not been previously described to our knowledge. The two-portal posterior endoscopic approach can be an attractive treatment alternative for the posterior part fractures of the talus, which can in turn, be a new indication for this technique.

Effect of decortication on laminar strength during sublaminar wiring: an experimental study.

Eighty lumbar segments from 16 female sheep were used to investigate the effect of laminar decortication on the strength of the lamina during sublaminar wiring procedure. Sheep were 12-14 months old. Forty vertebrae from eight animals were decorticated before loading with sublaminar wire to failure, and 40 vertebrae from the remaining eight sheep were tested with the same procedure but intact. The effects of bone mineral density (BMD) and laminar dimensions on laminar strength in both decorticated and nondecorticated groups were also investigated. The failure force values of the laminae for decorticated and nondecorticated groups were 881.15 +/- 36.86 and 298.48 +/- 21.99 N, respectively (P < 0.001). There was a positive linear relationship between BMD and laminar strength in an intact lamina. In a decorticated lamina, no significant relationship existed between these variables. There was a negative linear relationship between mediolateral length of hemilamina and laminar strength in both intact and decorticated vertebra. Laminar strength after decortication was positively related to dorsoventral length of the remaining portion of the lamina. Decortication leads to a statistically significant decrease in laminar strength.