Bisphosphonates reduce the rate of osteoporotic fractures in clinical trials and community practice. ''Atypical'' nontraumatic fractures of the diaphyseal (subtrochanteric or shaft) part of the femur have been observed in patients taking bisphosphonates. We calculated the incidence of these fractures within a defined population and examined the incidence rates according to duration of bisphosphonate use. We identified all femur fractures from January 1, 2007 until December 31, 2011 in 1,835,116 patients older than 45 years who were enrolled in the Healthy Bones Program at Kaiser Southern California, an integrated health care provider. Potential atypical fractures were identified by diagnostic or procedure codes and adjudicated by examination of radiographs. Bisphosphonate exposure was derived from internal pharmacy records. The results showed that 142 patients had atypical fractures; of these, 128 had bisphosphonate exposure. There was no significant correlation between duration of use (5.5 AE 3.4 years) and age (69.3 AE 8.6 years) or bone density (T-score À2.1 AE 1.0). There were 188,814 patients who had used bisphosphonates. The age-adjusted incidence rates for an atypical fracture were 1.78/100,000/year (95% confidence interval [CI], 1.5-2.0) with exposure from 0.1 to 1.9 years, and increased to 113.1/100,000/year (95% CI, 69.3-156.8) with exposure from 8 to 9.9 years. We conclude that the incidence of atypical fractures of the femur increases with longer duration of bisphosphonate use. The rate is much lower than the expected rate of devastating hip fractures in elderly osteoporotic patients. Patients at risk for osteoporotic fractures should not be discouraged from initiating bisphosphonates, because clinical trials have documented that these medicines can substantially reduce the incidence of typical hip fractures. The increased risk of atypical fractures should be taken into consideration when continuing bisphosphonates beyond 5 years. ß

The 5-year revision-free and CACLR-free survival rate in this study was 95.1% and 95.8%, respectively. Allografts and hamstring autografts had a higher risk of revision ACLR surgery, and BPTB autografts had a higher risk of CACLR. Males were found to have a higher risk of revision ACLR, and females had a higher risk of CACLR. Increasing age and increasing BMI decreased the risk of both revision and CACLR.

The overall SSI rate after ACLR was 0.48%. Deep SSIs were identified in 0.32% of the ACLR cases and superficial SSIs in 0.16%. An 8.2-times higher risk of SSIs was observed in hamstring tendon autografts compared with BPTB autografts. No difference in SSI incidence was identified between allografts and BPTB autografts. Surgeons should bear in mind that although the overall infection rates after ACLR are low, there is an increased risk of deep infections with hamstring tendon autografts.

Increased risk of medial meniscus injury and decreased repair rate were strongly associated with increasing time to surgery. Increased risk of cartilage injury was associated with increasing age, increasing time to surgery, and male gender.

Large, community-based ACLRRs are useful in informing participating surgeons of current treatment practices, prevalence of concurrent injuries, and outcomes associated with the procedures. Information from the ACLRR can be used to develop interactive patient and surgeon tools that can be used to optimize patient care.