High-pressure lavage produces greater visible damage to bone at a macroscopic and microscopic level when compared with low-pressure lavage and can result in delay in the healing of fractures. Osteoblasts and adipocytes are derived from mesenchymal stem cells. Conditions which lead to bone loss often involve a switch from the osteoblast to adipocyte lineage. We have therefore examined the effect of high- and low-pressure irrigation on the differentiation of adipocytes. Calvaria-derived bone cells were exposed to either low-pressure or high-pressure irrigation with normal saline. After 14 days the cells were fixed and the osteoblasts and adipocytes quantified using Oil Red O to stain cytoplasmic lipid droplets (triglycerides) in the cells. Osteoblasts were quantified using a commercially available alkaline-phosphatase staining assay. A standard quantitative reverse transcription-polymerase chain reaction (RT-PCR) was performed. Messenger RNA levels for osteocalcin, a marker of osteoblasts, and PPARγ2, a marker of adipocytes, were measured. High-pressure lavage resulted in an increase in adipogenesis of 50% when compared with low-pressure lavage. Our findings suggest that high-pressure lavage may promote differentiation of mesenchymal stem cells towards the adipoctye lineage. This may have clinical significance in the development of delayed and nonunion after treatment of fractures of long bones.
The reliability of the radiological assessment of the healing of tibial fractures remains undetermined. We examined the inter- and intraobserver agreement of the healing of such fractures among four orthopaedic trauma surgeons who, on two separate occasions eight weeks apart, independently assessed the radiographs of 30 patients with fractures of the tibial shaft which had been treated by intramedullary fixation. The radiographs were selected from a database to represent fractures at various stages of healing. For each radiograph, the surgeon scored the degree of union, quantified the number of cortices bridged by callus or with a visible fracture line, described the extent and quality of the callus, and provided an overall rating of healing. The interobserver chance-corrected agreement using a quadratically weighted kappa (κ) statistic in which values of 0.61 to 0.80 represented substantial agreement were as follows: radiological union scale (κ = 0.60); number of cortices bridged by callus (κ = 0.75); number of cortices with a visible fracture line (κ = 0.70); the extent of the callus (κ = 0.57); and general impression of fracture healing (κ = 0.67). The intraobserver agreement of the overall impression of healing (κ = 0.89) and the number of cortices bridged by callus (κ = 0.82) or with a visible fracture line (κ = 0.83) was almost perfect. There are no validated scales which allow surgeons to grade fracture healing radiologically. Among those examined, the number of cortices bridged by bone appears to be a reliable, and easily measured radiological variable to assess the healing of fractures after intramedullary fixation.
We have systematically reviewed the effect of alternative methods of stabilisation of open tibial fractures on the rates of reoperation, and the secondary outcomes of nonunion, deep and superficial infection, failure of the implant and malunion by the analysis of 799 citations on the subject, identified from computerised databases. Although 68 proved to be potentially eligible, only eight met all criteria for inclusion. Three investigators independently graded the quality of each study and extracted the relevant data. One study (n = 56 patients) suggested that the use of external fixators significantly decreased the requirement for reoperation when compared with fixation with plates. The use of unreamed nails, compared with external fixators (five studies, n = 396 patients), reduced the risk of reoperation, malunion and superficial infection. Comparison of reamed with unreamed nails showed a reduced risk of reoperation (two studies, n = 132) with the reamed technique. An indirect comparison between reamed nails and external fixators also showed a reduced risk of reoperation (two studies) when using nails. We have identified compelling evidence that unreamed nails reduced the incidence of reoperations, superficial infections and malunions, when compared with external fixators. The relative merits of reamed
We reviewed 52 children, born between 1974 and 1985 with spina bifida affecting L3 and L4, who had dislocated hips. Their motor function was stable and they were able to walk at the time of dislocation. They were interviewed and examined physically and radiologically. Physical function was measured by the Rand Health Insurance Study questionnaire (HIS), the Childhood Health Assessment questionnaire (CHAQ), and by determining the functional level of ambulation according to Hoffer et al (1973). In a subgroup of 12 patients with L4 level of involvement from both treatment groups we measured the metabolic energy consumption while walking. Thirty patients (49 hips) had been treated by operative relocation and 22 conservatively. Ten of the hips treated by operation subluxated or redislocated. The function in the two groups (conservative Patients with failed operations had worse function than those who were not operated on. The benefit of surgical relocation of the dislocated hips was marginal.
