Periacetabular osteotomy using an imageless computer-assisted navigation system: a new surgical technique.

Periacetabular osteotomy (PAO) is an effective surgical treatment for hip dysplasia. The goal of PAO is to reorient the acetabulum to improve joint stability, lessen contact stresses and slow the development of hip arthrosis. During PAO, the acetabulum is repositioned to adequately cover the femoral head. PAO preserves the weight-bearing posterior column of the pelvis, maintains the acetabular blood supply and retains the hip abductor musculature. The surgical technique needed to perform PAO is technically demanding, with correct repositioning of the acetabulum the most important-and challenging-aspect of the procedure. Imageless navigation has proven useful in other technically challenging surgeries, although its use in PAO has not yet been investigated. We have modified the standard technique for PAO to include the use of an imageless navigation system to confirm acetabular fragment position following osteotomy. Here, we describe the surgical technique and discuss the potential of this modified technique to improve patient-related outcomes.

Low rates of renal injury in total joint arthroplasty patients without pre-existing renal disease.

Acute kidney injury is a reported complication of total joint arthroplasty (TJA), with potentially severe long-term complications. Our study aimed to identify the rate of perioperative renal injury in patients without pre-existing renal dysfunction who undergo TJA. Using the American College of Surgeons National Surgical Quality Improvement Program database, we identified a mean annual rate of perioperative renal injury of 0.172% between 2009 and 2015. Factors most strongly associated with perioperative renal injury are age of 70 years or older, current smoking, history of diabetes mellitus, history of hypertension, and American Society of Anesthesiologists class of 3 or greater. There was no significant increase in the rate of renal injury from year to year. In patients without pre-existing renal disease, perioperative rates of acute kidney injury remain low in patients undergoing TJA.

The Role of Bariatric Surgery in the Obese Total Joint Arthroplasty Patient.

Although bariatric surgery is a proven means of weight loss and treatment of obesity-related comorbidities in morbidly obese patients, it is not yet clear how it affects outcomes after total joint arthroplasty in this high-risk patient population. This article explores the effects of obesity and bariatric surgery on osteoarthritis and total joint arthroplasty, and also discusses the financial and ethical implications of use of bariatric surgery for risk reduction before total joint arthroplasty.

Biomechanical Implications of an Oblique Knee Joint Line.

Surgical correction of multiapical deformities of the lower limb requires careful preoperative planning. Surgeons must account for the potential creation of secondary deformity, such as knee joint line obliquity, and the risks associated with accepting these changes in limb alignment. In this study, we evaluate the effect of knee joint obliquity on tibial plateau contact pressures and knee instability. Three cadaveric knees were dissected and put through biomechanical testing to simulate loading of an oblique knee joint. We observed < 1 mm femoral displacement (proxy measure of instability) between 15 degrees of varus tilt and 10 degrees of valgus tilt, and greater increases in tibial plateau contact pressures with valgus tilt than with varus tilt. Our results suggest that, if the creation of a secondary coronal plane deformity at the knee joint cannot be avoided, up to 15 degrees of varus or 10 degrees of valgus alignment can be tolerated by an otherwise structurally normal knee.