Background

Unicompartmental knee arthroplasty provides a good alternative to total knee arthroplasty in patients with isolated medial compartment osteoarthritis. There has been variable reporting in the literature as to whether age and sex affect the survival of unicompartmental knee arthroplasty. The aim of this study was to determine whether age and sex were predictors of failure for the Oxford unicompartmental knee arthroplasty.

Background

A number of studies have reported on the early failure of the Oxford unicompartmental knee arthroplasty. However, less evidence is available regarding the outcome following revision of failed unicompartmental knee prostheses to total knee arthroplasty. The aims of this study were to determine the time to failure for the Oxford unicompartmental knee arthroplasty and to assess the short-term outcome following revision surgery.

Aims

The purpose of our study was three fold; firstly to assess the survival of closing wedge high tibial osteotomies (CWHTO), secondly to assess any clinical factors or radiological alignment which may affect survival and thirdly to assess the change in tibial inclination and patella height.

Aims

The primary aim of this study was to determine the long-term survival of OATS (Osteochondral Autograft Transfer System) (Arthrex, Florida, USA) grafting in our centre and evaluate the reasons for failure, the secondary aim was to ascertain if age, gender, BMI, site or size of OATS graft had any influence on outcome.

Background

Unicompartmental knee arthroplasty provides a good alternative to total knee arthroplasty in patients with isolated medial compartment osteoarthritis. There has been variable reporting in the literature as to whether age and sex affect the survival of unicompartmental knee arthroplasty.

Background

A number of studies have reported on the early failure of the Oxford unicompartmental knee arthroplasty. However, less evidence is available regarding the outcome following revision of failed unicompartmental knee prostheses to total knee arthroplasty.

Introduction: Unicompartmental knee replacement (UKR) is a popular alternative to total knee replacement (TKR) in medial compartment disease. Early problems include bearing dislocation, persistent pain, stiffness and infection. Revision to TKR is well described as a late endpoint.

Objective: Investigate the early surgical management of persistent pain and debility following UKR, identify common themes and rate effectiveness of any re-intervention.

Methods: 381 UKRs implanted over 5 years included, and patients requiring re-operation reviewed retrospectively.

Findings: 27 re-operations performed on 17 patients at a mean 16.8 months (95% CI 9.5 to 24.1), with symptom onset post-operatively at 9 months (95% CI 4–14). There were 10 arthroscopies, 10 total knee replacements (revision), 4 manipulations under anaesthesia, 2 bearing exchanges, and 1 tibial-plateau fracture fixation. Manipulation under anaesthesia improved stiffness in 2 of 3 patients. Arthroscopy was successful in 2 patients with loose cement-bodies but did not provide a diagnosis in 8 patients, of whom 7 were revised subsequently after 17.1 months (95% CI 10.1 to 24.1) with 6 reporting symptom resolution. Overall there were 10 revisions: 9 were performed for persistent pain and 9 reported symptom improvement. Intra-operative findings included aseptic loosening (n=4), synovitis (n=2), increased posterior slope of the tibial cut (n=1), dislocated bearing (n=1), and no cause of failure in 2. Only two cases required revision implants with medial augments for bone loss. There were no deep infections.

Conclusions: The early re-intervention rate at our unit is 4.5% (95% CI 2.4 to 6.5), with a revision rate of 2.6% (95% CI 1.0 to 4.2) after a mean (±SD) follow-up of 40.1 (±16) months. Arthroscopy is a poor diagnostic and therapeutic option against persistent pain following UKR. In contrast, the decision to revise, although initially disappointing for both patient and surgeon, gave symptom improvement in 90%.

Unicompartmental knee replacement (UKR) is an increasingly popular alternative to total knee replacement in medial compartment disease. Early problems include unexplained pain, stiffness, infection and technical errors leading to dislocation of bearing or fracture. This study is the first to highlight re-intervention as an outcome measure when assessing the success of a partial joint replacement.

All Oxford UKRs undertaken at ROH during November 2002 and December 2007 were reviewed to identify patients who required a further procedure.

383 UKRs were implanted. 21 (5.5%) patients underwent further re-intervention. Twelve (3.1%) were for persistent post-operative pain, three (0.8%) for stiffness and six (1.6%) had a combination of symptoms. one re-intervention was for a tibial plateau fracture. Initial re-interventions included eleven arthroscopies and three manipulations.

Nine (2.4%) patients subsequently underwent revision procedures, eight to a total knee replacement with one revision to a fixed bearing unicompartmental prosthesis. There were no revisions for infection. Manipulation improved stiffness in all the patients. Outcome following re-interventions for persistent pain were less predictable. Arthroscopy improved symptoms in only 36% of patients but eight of the nine (88.9%) patients that were formally revised had an improvement in symptoms.

Our early re-intervention rate of 5.5% and the out-come of subsequent surgery provides a valuable evidence based resource to discuss potential post operative expectations and complications with patients awaiting an Oxford UKR.

Revision ACL reconstruction is becoming more frequent especially in specialized centers, due to the large numbers of primary ACL procedures performed.

In two stage revisions, bone grafting of the tunnels may be undertaken if the primary position was inaccurate or if osteolysis has caused widening of the tunnels. This will allow the desired placement of the new tunnels without the risk of loss of structural integrity.

It is technically difficult to deliver and impact bone graft into the femoral tunnel with the standard surgical and arthroscopic instruments.

We describe a new technique for femoral and tibial tunnels impaction grafting in two stage ACL revisions, utilizing the OATS grafting instruments.

The appropriately sized OATS harvester is chosen 1 mm larger than the tunnel size and is used to harvest bone graft from the iliac crest through a percutaneous approach. This provides a cylindrical graft, which is delivered to the femoral tunnel through the arthroscopic portal. The inside punch of the harvester is tapped, this allows delivery of the graft in a controlled manner, and allows impaction into the tunnel. The same is repeated for the tibial tunnel while providing support for the proximal end of the tunnel.