Early Functional Outcomes After Evolutionary Total Knee Arthroplasty: A Randomized Controlled Trial. Is New Always Better?

Total knee replacement (TKR) designs continue to evolve with the aim of improving patient outcomes; however, there remains a significant patient dissatisfaction rate. We report the early functional outcomes of an evolutionary knee design in the context of a single-blinded, noninferiority, randomized controlled trial. METHODS: Patients were randomized to receive either the P.F.C. SIGMA or ATTUNE knee implant systems (DePuy Synthes). All implants were fixed-bearing, cruciate-retaining, and cemented constructs. Patients were assessed at baseline and 6 weeks, 3 months, and 1 year postoperatively using clinical and functional outcome measures, including range of motion, Oxford Knee Score (OKS), Oxford Knee Score-Activity and Participation Questionnaire (OKS-APQ), Patient Knee Implant Performance (PKIP) score, 5-Level EuroQol 5 Dimensions (EQ-5D-5L), and Short Form-36 outcome measures. RESULTS: There were 150 patients who underwent a surgical procedure (76 with the ATTUNE implant and 74 with the P.F.C. SIGMA implant), with 147 patients remaining at the final review. No differences were observed in any of the outcome measures between the groups at any time point. Tourniquet time was significantly shorter in the P.F.C. SIGMA arm (p = 0.001); however, this had no clinical impact on the OKS (analysis of covariance [ANCOVA] test) at the final review (p = 0.825). There was no difference in the numbers of patients achieving the minimal clinically important difference for the OKS between the groups (p = 0.817). CONCLUSIONS: This trial did not show inferiority of the ATTUNE implant when compared with the P.F.C. SIGMA implant. The authors believe that implant innovation should continue and that modern implants should be introduced into the market following randomized controlled trials. Further work should assess the effect of non-implant-related factors on patient outcomes. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Thirty-day mortality following total knee arthroplasty over 7 years at a tertiary referral centre of orthopaedic excellence.

Total Knee Arthroplasty (TKA) is one of the most successful orthopaedic procedures. Around 100,000 TKAs are performed yearly in the United Kingdom. The aim of this study was to report the mortality rate within 30 days after a TKA in an Orthopaedic Centre of Excellence. We reviewed prospectively collected data of 7067 TKAs performed between April 2009-November 2016. All mortalities within 30 days of a TKA were recorded. Data such as age, sex, ASA, comorbidities and cause of death was recorded. There were 14 (0.198%) deaths within 30 days of TKA. There were eight male patients and six female patients who died. No statistical difference was demonstrated between gender. (p = 0.37). The mean age was 77.9 years (66-94 years). Means days to death from post-op were 9.6 days (2-30 days). One patient was ASA 1, six patients were ASA 2, six patients were ASA 3 and one patient did not have an ASA recorded. There was no statistical difference between the difference ASA groups. (p = 0.27). Cause of death documented was as follow: acute left ventricular failure-3; myocardial infarction-2; pneumonia-2; pulmonary oedema-1; gastrointestinal bleed-1 and multiorgan failure-1. Four patients did not have their cause of death recorded. The 30-day mortality rate after TKA in our institute is low and is comparable to other institutes. This emphasizes that primary TKA is a safe procedure. The predominant cause of perioperative mortality is cardiopulmonary disease.

Manipulation for stiffness following total knee arthroplasty: when and how often to do it?

Stiffness following total knee arthroplasty is a disabling complication. One of the management options of stiffness includes manipulation under anaesthesia, but no real consensus exist on appropriate timing of intervention, and the timing and results of the manipulation under anaesthesia (MUA) are under debate in the literature. Our aim was to determine the efficacy of single and multiple manipulations under anaesthesia following total knee arthroplasty and to determine the most appropriate timing for manipulation. We retrospectively reviewed 86 patients who underwent manipulation for stiffness following primary total knee replacement with at least 1-year follow-up. Range of motion before surgery, at the time of the MUA, immediately after MUA and at 6 weeks and 1 year post-MUA were recorded. At the end of 1 year post-manipulation, manipulations performed at less than 20 weeks, following primary total knee arthroplasty, showed 31° of flexion gain as compared to only 1.5° of flexion gain when manipulation was undertaken after 20 weeks. Of the 86 patients, 21 had multiple manipulations with no significant difference in flexion gain after the second manipulation. Patients on warfarin (26%) had an increased incidence of stiffness and poor flexion gain. This study showed that better results were achieved when manipulation was performed at less than 20 weeks (particularly between 12 and 14 weeks) from primary surgery with no added benefit from re-manipulations.

Patella denervation in primary total knee arthroplasty - a randomized controlled trial with 2 years of follow-up.

We randomized 126 consecutive patients undergoing primary total knee arthroplasty into group 1: patella denervation (n = 63) and group 2: no patella denervation (n = 63). Assessment was performed preoperatively and at 3, 12 and 24 months post-operatively. Average follow-up of patients was 26.5 months for denervation group and 26.3 months for no denervation group (P = 0.84). Pain scores for anterior knee pain were significantly better in the denervation group at 3 months but not at 12 and 24 months. Patient satisfaction was higher in the denervation group. Flexion range was higher in the denervation group at 3, 12 and 24 months review (P < 0.01). There were, however, no statistically significant differences with other validated knee scores.

Pain control after primary total knee replacement. A prospective randomised controlled trial of local infiltration versus single shot femoral nerve block.

BACKGROUND: We report a prospective blinded randomised trial of local infiltration versus femoral nerve block in patients undergoing primary total knee replacement (TKR), in accordance with the CONSORT statement 2010. METHODS: Fifty patients in a teaching hospital were consented for the study. The study arms were intraoperative local anaesthesia (150ml 0.2% ropivacaine/1ml 1:1000 adrenaline/30mg ketolorac) and femoral nerve block (30ml 0.2% ropivacaine) with a primary outcome of pain score at 4h post operatively. Secondary outcomes were pain at 2h, pain scores before and after physiotherapy on day one, total opiate administered, time to physiotherapy goals and length of stay. Randomisation was by sealed envelope. The assessor was blinded and the patients partially blinded to the intervention. RESULTS: Ten patients were excluded, eight before randomisation. The trial is complete. Forty patients were analysed for the primary outcome measure. The local infiltration group had significantly lower pain scores at 4h post-operatively; mean [SD] score 2.1 [2.6] versus 6.8 [3.2], p<0.00001 and on post-operative day one prior to physiotherapy; mean score 2.4 [2.3] versus 4.4 [2.3], p<0.05. Total opiate use was also significantly lower in the local infiltration group; mean total 115 [50.3]mg versus 176.5 [103.5]mg, p<0.01. There was no difference in any other outcome. There were no harms as a result of either intervention. CONCLUSION: Intraoperative local infiltration gives superior pain relief compared to single shot femoral nerve block over the first 24h following primary TKR and minimises post-operative opiate use.

Tissue necrosis after use of enoxaparin in total knee arthroplasty: a case report.

Tissue necrosis at the injection site of enoxaparin is a rare adverse effect. Most of the reported clinical course of this necrosis is uneventful. Here we review a case of tissue necrosis that developed after use of enoxaparin and required debridement followed by reconstructive surgery. Until now, such a case has not been reported in the English-language literature. As enoxaparin is being used more often for prevention of deep vein thrombosis in patients who undergo arthroplasty surgery, awareness and recognition of this adverse event and careful supervision of all patients who receive this medication are essential.

Patella in total knee arthroplasty: to resurface or not to--a cohort study of staged bilateral total knee arthroplasty.

The aim of this study was to assess medium term results of patellar resurfacing in total knee arthroplasty, specifically looking at anterior knee pain, patellofemoral function and need for reoperation. A prospective cohort study was conducted with patients undergoing staged bilateral knee arthroplasty with the patella being resurfaced only on one side. This was due to change in the clinical practice of the senior author. Sixty patients were reviewed clinically and radiologically on a regular basis. The surgery was either performed or supervised by the senior author in all cases. All patients received the cemented press-fit condylar© prosthesis. The Knee Society clinical rating system was used. Scores were recorded pre-operatively and post-operatively at three months, one year, two years and three yearly thereafter. The mean age of patients in the study group was 75 years (range: 62-89 years). There were 42 women and 18 men in the study. The mean duration of follow-up was 4.5 years (range: 2-12 years). There was no significant difference in the pre-operative scores in both groups. There were significantly better scores (p < 0.05) on the resurfaced side as compared to the non-resurfaced side at final follow-up. No revision was carried out for patellofemoral complications on the resurfaced side. Four patients required revision in the form of patellar resurfacing on the non-resurfaced side for persistent anterior knee pain. Patellar resurfacing is recommended in total knee arthroplasty for better functional outcome with regards to anterior knee pain and patellofemoral function.

Does intraarticular steroid infiltration increase the rate of infection in subsequent total knee replacements?

Steroid injection into the arthritic joint is a well-known treatment. Its efficacy is well documented. An increase in the incidence of infection secondary to steroid injection has been reported in recent literature. Based on the current literature we carried out a retrospective study to evaluate the incidence of infection in primary total knee arthroplasty as a result of previous steroid infiltration into the knee joint. In our study, 440 patients underwent total knee replacement between 1997 and 2005. Only 90 patients had intraarticular steroid injection prior to surgery, of which 45 patients had injection within 1 year prior to surgery. A matched cohort of 180 patients who had total knee replacement without steroid injection was used as control group to compare the infection rate. All patients had at least 1 year follow up. Two cases of superficial infection were noted in the study group and five cases of superficial infection in the control group. No cases of deep infection were noted in either group. Statistical analysis showed no significant difference in incidence of infection in either group (P value 1.0). This study showed no increase in the incidence of infection in patients with total knee arthroplasty with prior steroid injection.

Ten-year survival analysis of the PFC total knee arthroplasty--a surgeon's first 99 replacements.

Ninety-seven patients with 99 total knee arthroplasties were operated on by a surgeon in the first 3 years of his surgical career. Complete survival data were available for all 99 knees. The cases were reviewed at a minimum of 10 years after their initial operation, but as 37 patients had died before reaching 10 years, the average follow-up was 8 years 8 months with a maximum of 12 years 4 months. Ninety-one patients had osteoarthritis, five had rheumatoid arthritis, and three had juvenile chronic arthritis. No patients were lost to follow-up. Four required revision. The 10-year survival rate, using revision for all causes as an end-point, was 94.96%. The survival rate for aseptic loosening was 97.04%. The survival rate for loose joints that had not been revised was 94.13%. Three of the four revisions occurred in the first 6 patients operated upon, suggesting there may be a learning curve for surgeons at this stage in their career.

Medium-term results with the Press Fit Condylar (PFC) Sigma knee prosthesis the Wrightington experience.

The PFC Sigma total knee was introduced in 1997, incorporating a number of design changes. We report the mid-term results of a consecutive series of PFC Sigma knee arthroplasties performed between November 1997 and December 1998. Out of a total of 156 patients (166 knees), 5 patients (5 knees) were lost to follow-up and 6 patients (6 knees) died of unrelated causes. This left 145 patients (155 knees), 90 female and 55 male, with a mean age of 70 years (range, 53-88) and an average follow-up of 90 months (range, 84-96). Posterior cruciate retaining components were used in 136 knees (88%) and posterior-stabilized in 19 (12%). The patella was resurfaced in 74 (48%) knees. Follow-up was at 3, 6 and 12 months, then yearly. Preoperative American Knee Society and Oxford scores were compared with follow-up scores. The Knee Society radiological score was used for radiographic assessment. One knee (0.6%) was revised due to aseptic loosening. One knee (0.6%) had superficial wound infection, which settled with oral antibiotics. Two knees became deeply infected. Of these, one resolved following early debridement, the other developed chronic infection. Using revision for any reason as the end-point our cumulative success rate was 99.4%. The mean preoperative Knee score improved from 45 (30-65) to 84 (45-92), Functional score from 38 (25-55) to 73 (50-95) and Oxford score from 43 (33-52) to 17 (14-29). Radiographic review showed radiolucent lines in 54 (35%) tibial and 17 (11%) femoral components. The Radiological Knee Society score was less than 4 in all except one tibia where the score was 7. Our study shows excellent clinical results with the PFC Sigma total knee replacement after almost eight years follow-up.

Infection in primary hip arthroplasty after previous steroid infiltration.

Steroid Infiltration into arthritic joints is a common means of treating pain. It is also sometimes done to differentiate pain in the hip from that in the low back or knee. We performed a retrospective review of the notes of all patients who had undergone hip replacements in Wrightington Hospital under the care of the senior author (V.R.) from 1997 to 2004. We identified all patients who had at least 1 year follow up after the procedure. The infection rates in the patients who had received an injection of steroid into the joint prior to hip replacement and in a matched cohort who had received no such intervention were compared. In the injected group there was no incidence of infection during the period of follow up. There was one case of infection in a patient who had not had an injection prior to the arthroplasty. There was also a case of superficial infection in a patient who had no steroid infiltration prior to surgery, which responded to antibiotics. Steroid injections are a valuable adjunct in the management of patients with arthritic joints. This review clearly identifies no increased risk of infection in patients who had received the injection prior to the operation.