Early outcomes using a 'kinematic retaining' total knee replacement - A multicentre prospective study at two years follow-up.

BACKGROUND: Although predictable implant longevity in total knee replacement (TKR) is now established, work continues to satisfy the demands of patients who seek full restoration of the painless function of the native knee following TKR. This prospective study examines the early clinical outcomes of 156 patients implanted with a novel 'kinematic-retaining' (KR) implant. METHODS: 156 Physica KR TKRs were implanted for primary osteoarthritis at three European centres. Patients were reviewed up to two years using radiographic, clinical and functional evaluations. RESULTS: Of the 137 patients retained at two years' follow up, none had been revised. Within 6 post-operative months, 51.7% and 79.9% had excellent clinical and functional KSS values respectively, increasing to 81.8% and 88.3% beyond two years. Mean KSS improvement was 34.8 (from 48.6 to 83.4). All KOOS sub-scores improved significantly with total KOOS improving from a mean of 35.5 (SD ±13.0) to 86.5 (±13.7) at two years post-operatively. Pain and sports KOOS sub-scores improved rapidly during the early post-operative periods, with sustained improvements beyond this. Mean OKS improved by 44.1 (±5.1) at two years. VAS satisfaction scores improved significantly at all time points beyond six weeks. Mean FJS-12 was 75.7 at two years, with no significant effects of age or gender. No progressive adverse radiographic features were noted. CONCLUSIONS: Early clinical and radiographic outcomes of this kinematic-retaining knee prosthesis are promising, with improvements in clinical parameters similar to, or exceeding those published in other contemporary TKR designs. LEVEL OF EVIDENCE: II, Multicentre Prospective cohort study.

Systematic review: the safety of intra-articular corticosteroid injection prior to total knee arthroplasty.

BACKGROUND: Up to 30% of patients undergoing total knee arthroplasty (TKA) have received intra-articular corticosteroid injections prior to surgery. Debate exists as to whether such injections increase the rate of post-operative infection. Given that deep infection is a disastrous complication, a systematic review of the literature was undertaken to evaluate the safety of intra-articular corticosteroid injections given prior to TKA. Other features of corticosteroid use are also discussed including mechanism of action and optimal dosage. METHODS: Using PRISMA guidelines, EMBASE, CINAHL and MEDLINE databases were searched using the search terms 'total knee arthroplasty', 'replacement', 'corticosteroid', 'steroid', 'infection', 'safety', and relevant articles critically appraised. The Newcastle-Ottawa Scale was used to assess for bias. RESULTS: No level one or two studies were available for review. Two retrospective case control studies and two cohort studies (level three evidence) which specifically evaluated the risk of infected TKA in association with pre-operative steroid injection were reviewed: three showed that prior steroid injection was not associated with increased infection rates; one article showed that prior steroid injection was associated with a significantly increased risk of deep infection post-TKA. CONCLUSION: Clinicians commonly administer steroid injections to patients who are candidates for TKA but may be unaware of the potential long term complications. The included studies were underpowered and at risk of selection bias and only one study demonstrated an increased risk of infection post-operatively. We recommend that further research is required to evaluate the safety of steroid injection prior to TKA. LEVEL OF EVIDENCE: III.

Knee arthrodesis for limb salvage with an intramedullary coupled nail.

INTRODUCTION: The demand for revision and salvage procedures after knee arthroplasty is increasing as the number of primary procedures increases. Surgical salvage techniques when revision arthroplasty is contra-indicated include above knee amputation and arthrodesis. The results of arthrodesis are functionally superior to those of amputation but not all techniques of arthrodesis are associated with good results. MATERIALS AND METHODS: We present a single surgeon series of 14 consecutive patients who underwent arthrodesis of the knee with a customised intramedullary coupled nail (Mayday arthrodesis nail, Orthodesign Ltd, UK). All patients had a failed knee arthroplasty due to persistent sepsis. Pre-operative scaled radiographs were used to design and manufacture a custom-made implant for each patient. An identical surgical technique and post-operative rehabilitation regime were used in each case. RESULTS: The mean hospital stay was 12 days (range 6-24). Union was achieved in all but one patient at a mean of 4 months (range 3-10). One diabetic patient required subsequent above knee amputation for infected non-union. Two other patients had significant transient complications. CONCLUSION: We have found that the Mayday nail offers a straightforward, reproducible surgical option for difficult salvage surgery. Good results have been obtained in the majority of cases, avoiding the devastating consequences of above knee amputation.