Purpose

Use of a large femoral head metal-on-metal bearing in total hip arthroplasty may offer an advantage in terms of dislocation rates and more natural joint kinematics. The acetabular component is more rigid however in these prostheses and if not placed accurately can lead to increased levels of metal ion release. A prospective randomized controlled trial was conducted to quantify bone mineral density on the acetabular side, as well as compare metal ion levels from a standard metal-on-polyethylene bearing to a large head metal-on-metal bearing in primary total hip arthroplasty.

Purpose

Patients with anterior cruciate ligament (ACL) deficiency and symptomatic medial compartment osteoarthritis (OA) present a challenge in management. These are often younger than typical primary OA patients and aspire to remain athletically active beyond simple ADLs. Combined ACL reconstruction and valgus tibial osteotomy (ACLHTO) is a well documented surgical option for patients deemed wither too young or too active for total knee arthroplasty. Unicompartmental knee arthroplasty (UKA) is an established surgical treatment for symptomatic medial osteoarthritis of the knee refractory to conservative management. A commonly cited contraindications is symptomatic ACL deficiency because of previous reports detailing premature failure through loosening of the tibial component. Improved results and endoscopic ACL reconstructive procedures have led to an enticing concept of combining ACL reconstruction with medial unicompartmental knee arthroplasty (ACLUKR) for those ACL-deficient medial osteoarthritic (OA) knees. We sought to compare the outcomes in 2 cohorts of patients who underwent either ACLHTO or ACLUKR for this clinical problem.

Purpose: Unicompartmental replacement for medial compartment arthrosis of the knee has become popular with eligible patients because of the shortened recovery time, decreased tissue damage and easier future revision. Contemporary multimodal anesthesia has added the potential to safely perform this as outpatient surgery reducing inpatient bed burden. We describe our initial pilot experience with this approach.

Method: The first 25 patients who fulfilled the criteria developed underwent same day surgery for unicompart-mental arthroplasty for medial (19) or lateral (3) compartment replacement with either the Oxford knee (20) or the Uniglide (2). All patients were treated with an indwelling femoral nerve catheter supplied by Ropivacaine through a constant release pump (Stryker) which was discontinued at 48 hours. Home care support was made available in first 72 hours by way of RN and physiotherapy visits and mandatory use of walker or crutches for the first 48 hours.

Results: Patients in this cohort were universally very satisfied with the model of postop care as described and particularly pleased to avoid a hospital stay. Eighty percent of those who were offered this model chose it. The use of narcotic oral medication was consistently about 50% less than that observed to similar inpatients treated without catheter, and eight patients had complete opioid sparing experience. There were no complications related to the catheter, in particular serious falls or longer term neurologic sequelae. The clinical results were very good and equal to those who were in patients.

Conclusion: Outpatient unicompartmental replacement can be performed safely recognizing the decreased surgical trauma and pain stimuli associated with UKR and a relatively younger and healthier cohort screened for this alternative. These patients are amongst the most satisfied with their perioperative course and all would do the same again if given the chance. Other models of analgesia could be considered, though the catheter does seem to have a large opioid sparing effect that likely contributed to patient well being and satisfaction.