Periprosthetic BMD after cemented and uncemented total hip arthroplasty: a 10-year follow-up study.

BACKGROUND AND PURPOSES: Insertion of a metallic implant into the femur changes bone loading conditions and results in remodeling of femoral bone. To quantify these changes in bone mineral density (BMD) after total hip arthroplasty, we monitored femoral bone with dual X-ray absorptiometry (DXA). MATERIALS AND METHODS: The periprosthetic bone mineral density was measured in seven Gruen zones at scheduled time intervals during a 10-year follow-up. A total of 38 patients went through either cemented (n = 13) or uncemented arthroplasty (n = 25). RESULTS: During the 1st post-operative year BMD decreased markedly in both groups mainly in the calcar area (Gruen zone 7); 21.9 % in the uncemented group (p < 0.005) and 26.1 % in the cemented group (p < 0.005). After that there was a slight continuous BMD loss in the proximal part of the femur and a slight increase in the distal part of femur, especially after uncemented THA. In the non-operated control side, BMD showed only a slight decrease during the follow-up (0.9 %, p = 0.003). INTERPRETATION: The study shows that when a good prosthesis-bone integration with or without cement is achieved, remodeling of the periprosthetic bone decreases after the 1st post-operative year and the bone loss reflects merely normal ageing.

Cemented or uncemented hemiarthroplasty for the treatment of femoral neck fractures?

BACKGROUND AND PURPOSE: Cemented hemiarthroplasty is preferred in treating displaced fractures of the femoral neck in the elderly. The cementing process may cause a fat embolism, leading to serious complications or death. In this study, we wanted to determine whether use of uncemented hemiarthroplasty (HA) would lead to reduced mortality and whether there are differences in the complications associated with these different types of arthroplasty. PATIENTS AND METHODS: From the PERFECT database, which combines information from various treatment registries, we identified 25,174 patients who were treated with hemiarthroplasty for a femoral neck fracture in the years 1999-2009. The primary outcome was mortality. Secondary outcomes were reoperations, complications, re-admissions, and treatment times. RESULTS: Mortality was lower in the first postoperative days when uncemented HA was used. At 1 week, there was no significant difference in mortality (3.9% for cemented HA and 3.4% for uncemented HA; p = 0.09). This was also true after one year (26% for cemented HA and 27% for uncemented HA; p = 0.1). In patients treated with uncemented HA, there were significantly more mechanical complications (3.7% vs. 2.8%; p < 0.001), hip re-arthroplasties (1.7% vs. 0.95; p < 0.001), and femoral fracture operations (1.2% vs. 0.52%; p < 0.001) during the first 90 days after hip fracture surgery. INTERPRETATION: From registry data, mortality appears to be similar for cemented and uncemented HA. However, uncemented HA is associated with more frequent mechanical complications and reoperations.

Effect of locally administered zoledronic acid on injury-induced intramembranous bone regeneration and osseointegration of a titanium implant in rats.

BACKGROUND: Intramedullary implantation causes injury-induced stimulation of intramembranous bone regeneration. Intramedullary bone injury along with stress shielding may induce periimplant bone loss and cause early aseptic loosening of an implant. The aim of this study was to determine the effect of locally administered zoledronic acid on periimplant bone and injury-induced stimulation of intramembranous bone regeneration in a rat model. METHODS: A total of 28 male rats had a titanium implant inserted into their right femur. During the operation, the medullary canal was lavaged using 20 muM zoledronic acid (Zometa 4 mg/5 ml) or sodium chloride. Follow-up times were 4 and 12 weeks, with each follow-up group consisting of seven rats. The femurs with the titanium implants in situ were harvested, and three microscope sections were cut from each femur. The sections were photographed and analyzed with the Analysis computer program. RESULTS: Between 4 and 12 weeks, the length of fluorescence bone contact increased significantly in both groups (control 15.7% SD and zoledronic acid 18.8% SD), although the difference between the groups was not significant. Periimplant bone volume (thickness) was increased in the 4-week zoledronic acid group compared to the controls (+/-13.4%, P = 0.002) but at 12 weeks the groups no longer differed from each other. CONCLUSIONS: Our results suggest that zoledronic acid may prevent injury-induced bone loss near an intramedullary implant by inhibiting bone resorption shortly after implantation. This may provide better periimplant bone stock during the early postoperative period.

Preliminary experience of a single session of low-energy extracorporeal shock wave treatment for chronic plantar fasciitis.

BACKGROUND: The purpose of the present study was to evaluate the effect of a single session of ultrasound- and biofeedback-assisted extracorporeal shock wave treatment (ESWT) in patients with chronic plantar fasciitis. MATERIALS AND METHODS: 20 patients (22 heels) with symptomatic plantar fasciitis that did not respond to conservative treatment for at least 6 months were studied. Patients received a single session of low-energy, ultrasound- and patient feedback-guided ESWT. Visual analog scale (VAS) was used to compare pain intensity before treatment and at followup (72 +/- 15 days after treatment). RESULTS: There was a significant decrease in overall pain (VAS 5.5 +/- 1.8 vs. 3.3 +/- 2.7, p = 0.001), maximum pain (7.7 +/- 2.1 vs. 4.0 +/- 3.9, p = 0.008) and pain at activities of daily living (5.3 +/- 2.1 vs. 2.5 +/- 2.6, p = 0.018). Night pain decreased to a lesser extent (2.4 +/- 2.5 vs. 1.3 +/- 2.1, p = 0.317). ESWT improved symptoms in 16 heels, of which six were completely symptom-free at followup 2.4 months after treatment. Six patients experienced no change. Fourteen patients with pain localized to the heel and all male patients benefited from ESWT. No difference was noted for age, body mass index, duration, and severity of symptoms or previous treatment. CONCLUSION: Low-energy ESWT proved to be an effective treatment option for the majority of patients with chronic plantar fasciitis that failed to respond to conservative treatment. Predictive parameters for successful outcome are male gender and an easily detectable pain center at the heel.

Periprosthetic bone loss after cemented total hip arthroplasty: a prospective 5-year dual energy radiographic absorptiometry study of 15 patients.

In this prospective 5-year study, we determined the periprosthetic bone loss after cemented total hip arthroplasty (THA) in 15 patients using dual energy X-ray absorptiometry (DXA). A reduction in the periprosthetic bone mineral density (BMD) of 5-18% occurred in all Gruen regions, or regions of interest (ROI), during the first 3 months after THA. The bone loss continued up to 6 months in almost all ROIs. From 1 to 5 years, we found only minor changes in BMD in periprosthetic bone. After the follow-up, the mean greatest bone loss (26%) was seen in the femoral calcar area. The reduction in mean BMD was 5% in men, and 16% in women. The lower the preoperative BMD, the higher was the postoperative bone loss. We found that after the phase of acute bone loss, further loss was minimal, reflecting merely the normal ageing of bone after uncomplicated THA.