Background: Recent studies have shown that local infiltration analgesia (LIA) improves outcome after total hip replacement (THA). No detailed information does exist to its influence on length of stay (LOS) after surgery. In this study we have evaluated LOS, pain treatment, mobilization, postoperative nausea and vomiting (PONV) and satisfaction in a period before and after implementing LIA in our department.

Patients and Methods: Patients diagnosed with primary osteoarthrosis of the hip scheduled for unilateral uncemented or hybrid THA were included in the study. All cases were recognized from a local database with prospective collected data on all patients undergoing THA in our department. Total 100 consecutive patients who did not have LIA from September 1st 2006 were compared with 100 consecutive patients who received LIA from September 1st 2007. The two groups were unmatched and no patients were excluded. The solution used for LIA consisted of 200 mg Ropivacain, 30 mg Ketorolac and 1 mg Adrenaline dissolved in 100 ml isotone NaCl.

Results: Patients in the two groups were similar in regard to gender, age, body mass index (BMI) and ASA group, but did differ in duration of the surgical approach, the latter group having treatment with LIA in average had a 20 minuts shorter surgical approach. The patients who received LIA had reduced LOS, mean 3.8 days compared to 5.1 days in the gropu not treated with LIA (p< 0.001). Moreover, patients treated with LIA were significant more satisfied (p< 0.05) compared to the group who did not receive LIA. Moreover, patients treated with LIA were more frequently mobilized on day 1 after surgery (p< 0,001) and day 3 as well (p< 0.05). Also, patients treated with LIA had significantly reduced PONV on the day of operation (p< 0.05) and well as they consumed more nutrition (p< 0.001) the day after the operation. There was no difference in pain-score between the two groups except on day 3 (p< 0.05) in activity and at rest on the day of discharge (p< 0.05). No wound complications could be shown in any of the groups during the first 6 weeks after surgery.

Interpretation: Introducing LIA in our department changed the postoperative period detailed in several ways for patients undergoing THA. This study document that operative wound infiltration with multimodal drugs reduced LOS after THA, even though the reduced duration of operation may be some of the explanation. Moreover, LIA resulted in better mobilisation, less PONV and more satisfied patients. We recommend all unit undertaking THA to implement LIA in their daily praxis.

Introduction: NSAID’s are routinely used as either pain-killer or in prevention of heterotopic bone formation (HBF) after total hip replacement (THR). Experimental animal studies have in two decades shown NSAID’s to influence bone remodelling, and thereby also to reduce fixation and bone healing round non-cemented implants. Clinical studies have, however, non been able to demonstrate these observations, too. This may be due a low power in such studies with only few observations. The present study present results from The Danish Hip Arthroplasty Register (DHR) on the effect of NSAID’s to revision of cemented implants due aseptic loosening.

Materials and Methods: DHR was established January 1, 1995 and covers all Danish clinics. All report both primary and revision cases to a central database. Every Danish citizen have an unique civil register number - making it possible to follow both primary and revision cases and to investigate survival due various circumstances. Cox’s regression analysis to estimate the relative risks (RR) of revision and data are presented with 95% confidence intervals.

Results: During the period 1995–2006 total 64.725 primary THR’s were recorded in DHR. Of these 8.531 cases had prophylactic NSAID after surgery in prevention of HBF. Total 409 hips (4.8%) of this population undergoing revision THR had been treated with NSAID’s after surgery. In contrast, 2.536 (4.3%) undergoing revision in the population had no NSAID’s. Overall the risk for revision for any reason was reduced for patients treated with NSAID’s (RR = 0.88 (0.79–0.98) p=0.02). This was even more significant in revision due to aseptic loosening (RR = 0.76 (0.64–0.90) p< 0.01). Subgroup analysis showed that the reduction was in the cemented THR (RR = 0.82 (0.70–0.95) p=0.01) with a further more significant sign in revision due aseptic loosening (RR = 0.69 (0.55–0.87) p< 0.01). In contrast there was no differences in cementless THR neither in revision for any reason (RR = 1.19 (0.86–1.63) p=0.30) nor for aseptic loosening (RR = 1.72 (0.87–3.43) p=0.12).

Discussion and Conclusion: The present investigation from the DHR is a good example of what can be evaluated from a register, and never possibly concluded from standard clinical studies. The results demonstrate that NSAID’s administrated in order to prevent HBF after primary THR surprisingly did not increase the risk of revision in non-cemented implants, but in contrast did reduce the risk for revision in cemented THR. The reason for this reduction is speculated, and be relate to the phenomenon that NSAID’s did not only influence the osteoblastic activity, but also the osteoclasts and thereby prevent early postoperative bone degradation after cemented THR where heat from the bone-cement may impose devascu-larisation of vital bone near the implant.