Reduced Sirtuin1 expression at the femoral neck in women who sustained an osteoporotic hip fracture

To investigate the role of Sirtuin1 in osteoporosis, Sirtuin1 was determined at the femoral neck in female patients undergoing hip operation for fractured hip or osteoarthritis. Reduced Sirtuin1 was found in osteoporotic patients. Pharmacologic activation of Sirtuin1 reduced sclerostin, an inhibitor of bone formation. Activation of Sirtuin1 may be a new direction to generate therapies for osteoporosis.

INTRODUCTION

The aim of the study are to investigate the role of Sirtuin1 (Sirt1), an anti-aging factor and a player in age-associated diseases, in osteoporotic hip fractures, and test the hypothesis that Sirt1 is a negative regulator of sclerostin, a bone formation inhibitor, in human femoral bone marrow mesenchymal cells (BM-MSCs).

METHODS

Sirt1 and sclerostin were determined by western blot in bone samples obtained intra-operatively from the inferior medial cortex of the femoral neck (calcar region) in female patients undergoing partial hip replacement for fractured neck of femur (N = 10) or hip replacement for osteoarthritis (N = 8) (mean ± SD age 81 ± 8.1 vs. 68 ± 9.3 years; BMI 26.2 ± 3.6 vs. 25.9 ± 7.1 kg/m(2) in osteoporotic and osteoarthritis patients). Calcar thickness and femoral bone mineral density (BMD) were determined preoperatively by X-ray using a digital TraumaCad(™) software and DEXA. Femoral BM-MSCs were collected intra-operatively and treated with SRT3025, a Sirt1 activator. Sclerostin and dentin matrix acidic phosphoprotein (DMP1) were determined by western blot and messenger RNA (mRNA) expression of Lef1 and DMP1 was evaluated by quantitative real-time PCR.

RESULTS

Osteoporotic (OP) patients had reduced cortical thickness, femoral neck, and total hip BMD compared to osteoarthritis (OA) patients. Calcar Sirt1 expression was significantly reduced, while sclerostin was markedly increased in OP compared to OA patients. Sirt1 and sclersotin expressions were inversely correlated (r = -0.49, P = 0.047). SRT3025 administration down-regulated sclerostin and up-regulated DMP1 protein level and increased LEF1 and DMP1 mRNA expressions in OP patient-derived BM-MSCs.

CONCLUSIONS

Reduced femoral neck Sirt1 may play a role in osteoporotic hip fractures in part via influencing local sclerostin expression. The therapeutic potential of Sirt1 activation in osteoporosis warrants further investigation.

Intraoperative 3-dimensional imaging of scaphoid fracture reduction and fixation

INTRODUCTION

We examined the clinical benefit of two intraoperative three-dimensional imaging modalities for reduction and fixation of scaphoid fractures.

HYPOTHESIS

Our hypothesis was that three dimensional imaging will aid in operative care in comparison with standard fluoroscopy.

METHODS

In 25 consecutive patients treated for fractures, after satisfactory reduction and fixation was obtained with a single Kirschner wire using fluoroscopy, intraoperative three-dimensional visualization was performed. The quality of fracture reduction, wire position and extrusion of the wire were examined.

RESULTS

In two of the 25 cases, after three-dimensional visualization, malreduction of the fracture was seen and the reduction revised. Artifact and the dependency on technologist performance, limited the use of these modalities to locate the wire accurately.

DISCUSSION

Diagnosis of malreduction of a scaphoid fracture is possible with 3-dimensional modalities. Utilization of these systems is still limited by technical factors.

Bracing in external rotation for traumatic anterior dislocation of the shoulder

We undertook a prospective study in 51 male patients aged between 17 and 27 years to ascertain whether immobilisation after primary traumatic anterior dislocation of the shoulder in external rotation was more effective than immobilisation in internal rotation in preventing recurrent dislocation in a physically active population. Of the 51 patients, 24 were randomised to be treated by a traditional brace in internal rotation and 27 were immobilised in external rotation of 15 degrees to 20 degrees. After immobilisation, the patients undertook a standard regime of physiotherapy and were then assessed clinically for evidence of instability. When reviewed at a mean of 33.4 months (24 to 48) ten from the external rotation group (37%) and ten from the internal rotation group (41.7%) had sustained a further dislocation. There was no statistically significant difference (p = 0.74) between the groups. Our findings show that external rotation bracing may not be as effective as previously reported in preventing recurrent anterior dislocation of the shoulder.

Porcine small intestine submucosa as a flexor tendon graft

An attractive strategy for tendon tissue engineering is the use of natural extracellular matrices as scaffold materials. One matrix that has been shown to promote healing and regeneration of neotissue in various applications is porcine-derived small intestinal submucosa. It was the objective of this study to investigate small intestinal submucosa for intrasynovial flexor tendon grafting in a canine model. We hypothesized that at 6 weeks small intestinal submucosa grafts would undergo host cell infiltration, neovascularization, and replacement by host neotendon. We also hypothesized that small intestinal submucosa grafts would be incorporated by the host without extensive adhesions to surrounding tissues and therefore maintain normal digit function. An intrasynovial tendon autograft was used as a gold standard. At 6 weeks the intrasynovial tendon autografts remained viable, contained normal numbers of cells along their length, and had minimal peritendinous adhesions. Four of six autografts had normal function as determined by rotation of the distal interphalangeal joint. Also at 6 weeks, the small intestinal submucosa grafts had host cell infiltration, neovascularization, and wavy, oriented tissue. However, ubiquitous adhesions together with impaired function in all cases suggest that small intestinal submucosa grafts in the configuration used are not suitable as full-length intrasynovial grafts in this tendon and animal model.

The floating hip injury: patterns of injury

OBJECTIVE

To evaluate the relationship between mechanism of injury, type of femoral fracture and type of acetabular fracture in floating hip injury.

DESIGN

Historical retrospective.

PATIENTS

Twenty consecutive patients who sustained a floating hip injury, i.e. simultaneous ipsilateral fracture of the acetabulum and the femur.

INTERVENTION

Statistical analysis of the correlation between the mechanism of injury and fracture type.

RESULTS

Two main patterns of floating hip injury were observed. The first is the posterior type, which occurs due to a longitudinal force along the femur that causes first, a posterior type fracture of the acetabulum and thereafter, a midshaft femoral fracture. The second pattern is the central type, caused by a lateral blow to the greater trochanter, which then causes a central fracture-dislocation of the acetabulum and a proximal fracture of the femur.

CONCLUSIONS

This observation explains the biomechanical nature of this injury and has treatment related implications.

Proximal tibial fractures--should we nail them?

Intramedullary nails (IMNs) are the treatment of choice for diaphyseal tibial fractures. Its use has been expanded both distally and proximally to cover metaphyseal fractures at both ends of the tibia. Several authors have stated that IMN use in proximal tibial fractures (extra-articular) can become problematic, leading to a significantly increased rate of malunion. Different strategies for solving this problem have been reported in recent years, but no strategy is fault-free. We review the causes of and solutions for increased malunion following use of IMNs for proximal tibial fractures.

Retrograde nailing of femoral fractures distal to previous osteosynthesis

As the proportion of elderly in the population grows, the incidence of femoral fractures distal to previous proximal osteosynthesis is increasing. When the gap between two rigid load-bearing fixations consists of osteopenic bone, the risk of further fractures increases. Herein the authors describe a load-sharing device that stabilizes the fracture and eliminates the osteopenic gap, allowing early mobilization and rapid return to the preinjury level of activity.

Surgical treatment of intercondylar fractures of the humerus in adults

The rarity, complexity, and intra-articular involvement of intercondylar fractures, along with the osteopenic nature of the elbow joint, make surgical repair of these fractures a difficult and challenging task. When the procedure is properly executed, open reduction and internal fixation can promote proper reduction of the articular fragments and allow early range-of-motion exercises, which are so important for good functional results. We report the results of 30 such fractures treated surgically with good or excellent results. The pros and cons of the transolecranon approach are discussed, along with the options of fracture fixation and importance of early postoperative mobilization.

The unreamed tibial nail in the treatment of distal metaphyseal fractures

In recent years biological surgical solutions have been recommended in cases of distal tibial fractures, with the aim of reducing damage to soft tissues and to bone vascular supply. Between the years 1991-1995, 52 patients suffering from fractures of the distal tibial metaphysis were treated in our department with an unreamed tibial nail (UTN). Fractures were categorized in accordance with the AO Classification. 32 fractures had no articular involvement (43A1, 43A2, 43A3) and 20 included intra-articular extension (43C1, 43C2). 32 fractures had significant metaphyseal comminution (43A2, 43A3, 43C2). 12 were open fractures. All the fractures were treated by means of UTN using distal locking. In 13 patients an additional percutaneous interfragmentary fixation was also applied. 22 patients underwent an additional operation in order to facilitate bone union (dynamization, bone grafting and/or fibulectomy). In 50 of the 52 patients the fracture united with a very good range of knee and ankle motion. In 2 patients non-union with breakage of the UTN occurred and in two open fractures post-operative infections were observed. Our experience with the treatment of fractures of the distal tibia, including intra-articular fractures with no comminution, points at an excellent functional outcome with a low incidence of complications.

Femoral fracture at the proximal end of an intramedullary supracondylar nail: a case report

Retrograde intramedullary supracondylar nails have been added to the orthopedic armamentarium for treatment of distal femoral fractures. Major complications of this new technique have not been noted. We report a case of a femoral fracture at the proximal end of a retrograde intramedullary supracondylar nail. We hypothesize that this complication may be due to the proximal end of the nail acting as a stress riser, with the cortical holes drilled for the interlocking screws compounding this effect.

Sequential or simultaneous, same-day anterior decompression and posterior stabilization in the management of vertebral osteomyelitis of the lumbar spine

STUDY DESIGN

A retrospective clinical study of patients with vertebral osteomyelitis of the lumbar spine necessitating surgical treatment. All patients underwent sequential (same-day) or simultaneous anterior decompression and posterior stabilization of the involved vertebrae.

OBJECTIVE

To evaluate the efficacy and clinical out-come of sequential or simultaneous anterior and posterior surgical approaches in the management of vertebral osteomyelitis of the lumbar spine.

SUMMARY OF BACKGROUND DATA

Anterior approach alone and staged anterior decompression and posterior stabilization have been advocated as the surgical treatment methods of choice for patients with vertebral osteomyelitis of the lumbar spine. The drawbacks of the latter management plan are the necessity to use external support or the delayed patient mobilization and the need for additional anesthesia and surgical trauma. Sequential (same-day) anterior and posterior approaches are used regularly in the surgical management of scoliosis and other spinal deformities. It would appear advantageous to also use the same strategy (i.e., combined same-day double approaches) in the management of vertebral osteomyelitis of the lumbar spine.

METHODS

Ten consecutive patients who had a diagnosis of vertebral osteomyelitis of the lumbar spine underwent combined (same-day) anterior and posterior approaches either in a sequential or simultaneous manner. Indications for surgery included neurologic deficit, abscess formation, instability with localized kyphosis formation, and failure of nonoperative treatment. Patients were evaluated clinically and radiographically after surgery.

RESULTS

All 10 patients had uneventful surgery. Only one patient required a second surgical procedure because of expulsion of the anterior bone graft and pull-out of instrumentation. All patients were mobilized within the 2 days immediately after surgery. At the mean follow-up examination 30 months after surgery, all patients had regained their motor function and prior ambulatory status.

CONCLUSIONS

Patients with lumbar osteomyelitis necessitating surgery can undergo combined, same-day surgery either in a sequential or simultaneous manner. This is a safe and efficient way to control the infection and stabilize the affected segments, allowing for early mobilization of these sick elderly patients.

[Surgical repair of fractures of the clavicle in the adult]

Clavicular fractures make up 45% of shoulder girdle fractures. The clavicle's susceptibility to injury is due to its subcutaneous position and its role as the bony connection between the thorax and the shoulder. In 95% of cases the mechanism of injury is a direct blow to the shoulder. These fractures are usually treated conservatively without surgery. But there are a few such fractures that require surgical repair in order to unite well. 9 patients were operated on for clavicular fractures during 1991-1995. The indications for surgical repair were lateral-third fracture, floating shoulder, neurovascular deficit or nonunion. The methods used were open reduction and fixation with either plate and screws, Kirchner wires, cerclage or a combination. All fractures united well, with no infections or new neurovascular deficits. Good range of shoulder motion and acceptable cosmetic results were achieved in all. 1 patient had functional limitation due to brachial neuritis caused by brachial damage at the time of injury. Indications for surgical repair and the methods used in these cases are similar to those described in the literature. The high rate of union and absence of complications support surgical repair for the few calvicular fractures that are not likely to unite properly.