A prospective randomised controlled trial of cemented and uncemented tibial baseplates: functional and radiological outcomes.

INTRODUCTION: With the success of uncemented fixation in younger patients undergoing total hip arthroplasty and the growing demand for total knee arthroplasty (TKA) in a younger cohort of patients, there has been an increasing interest in cementless tibial baseplate fixation. We sought to determine whether there was a clear advantage to the use of three different forms of tibial baseplate fixation. The primary outcome of this study was survivorship and secondary outcomes were functional and radiological outcomes, up until 10 years. MATERIALS AND METHODS: We conducted a randomised controlled trial and recruited 224 patients with 274 knees. Patients underwent TKA by a single surgeon utilising a standard surgical technique. All patients received a cruciate retaining TKA with a cementless femoral component, and were randomised to receive either a cemented tibial component, a pegged porous coated cementless tibial component with screws or a cementless tantalum monoblock tibial component with pegs. Patient reported outcome measures (PROMS), radiological data and survivorship were assessed until 10 years post-operatively. RESULTS: Pre-operative range of motion, alignment and PROMS were similar between the three groups. The use of cemented, cementless with screws or cementless with pegs fixation options, lead to differences in functional outcomes. There was greater improvement in the Oxford score and Knee Society Score in patients who received a cemented baseplate compared to tantalum and the pegged porous groups. However, radiological and survival outcomes were similar in all three groups. Overall survivorship was 99.6%, with one knee with cementless tibial fixation and screws revised for subsidence at 3 years. There were no cases of venous thromboembolism, periprosthetic fracture or infection. CONCLUSIONS: Irrespective of tibial fixation method, functional and radiological outcomes remain similar at follow-up at 10 years, with no clear difference in outcome between each group. Each method of fixation also had excellent survivorship over this period and should reassure surgeons that whichever method of fixation they choose, long-term outcomes are likely to be satisfactory.

Infectious arthritis of the knee caused by Mycobacterium terrae: a case report.

Mycobacterium terrae is ubiquitous in our environment. M terrae infections most commonly involve tendon sheaths, bones, bursae, and joints. We report a case of infectious arthritis of the knee caused by M terrae in a 21-year-old man who had non-specific chronic synovitis. No organism was seen on microscopy or isolated from cultures until months later. Initially the M terrae culture was considered a contaminant and specific anti-mycobacterial treatment was not advised. The patient was commenced on suppressive therapy for persistent effusion and discomfort. Eventually, the M terrae infection was confirmed and he was commenced on clarithromycin, ciprofloxacin, and ethambutol. The triple antibiotic regimen was continued for 2 years. The knee improved but never completely settled. The patient chose to cease all antibiotic medication. The knee remained swollen and irritable, with little chance of eradicating the organism.

Complex regional pain syndrome complicating total knee arthroplasty.

PURPOSE: To compare the long-term outcome of patients diagnosed with complex regional pain syndrome-type 1 (CRPS-1) after total knee arthroplasty (TKA) with those of uncomplicated TKA knees and preoperative osteoarthritic knees. METHODS: Medical records of 1280 patients who underwent TKA for osteoarthritis were retrospectively reviewed; 8 were diagnosed as having symptoms and signs consistent with CRPS after TKA. Patients with primary inflammatory arthritis, signs of component loosening, malpositioning, or of infected arthroplasty were excluded. No patient had signs of CRPS prior to operative intervention. The 8 patients were compared with 2 groups of age- and sex-matched controls: uncomplicated TKA knees and preoperative osteoarthritic knees. Patients were followed up for a mean of 54 (range, 13-111) months and their range of movement, Western Ontario and McMaster Universities Osteoarthritis Index, SF-36 questionnaire scores, and Knee Society scores were assessed and compared. RESULTS: After appropriate treatment, most CRPS complicated patients had similar scores on SF-36, Western Ontario and McMaster Universities Osteoarthritis Index, and Knee Society scores when compared with uncomplicated TKA patients. Scores for CRPS complicated patients were significantly improved when compared with preoperative osteoarthritic patients. The incidence of CRPS after TKA was 0.7%. CONCLUSION: When managed early, patients complicated with CRPS after TKA have a similar prognosis to patients with uncomplicated TKA.