Lawrence Kohan

BACKGROUND: We have developed a multimodal technique for the control of pain following knee and hip surgery, called "local infiltration analgesia" (LIA). It is based on systematic infiltration of a mixture of ropiva-caine, ketorolac, and adrenaline into the tissues around the surgical field to achieve satisfactory pain control with little physiological disturbance. The technique allows virtually immediate mobilization and earlier discharge from hospital. PATIENTS AND METHODS: In this open, nonrandomized case series, we used LIA to manage postoperative pain in all 325 patients presenting to our service from Jan 1, 2005 to Dec 31,2006 for elective hip resurfacing (HRA), primary total hip replacement (THR), or primary total knee replacement arthroplasty (TKR). We recorded pain scores, mobilization times, and morphine usage for the entire group. RESULTS: Pain control was generally satisfactory (numerical rating scale pain score range 0-3). No morphine was required for postoperative pain control in two-thirds of the patients. Most patients were able to walk with assistance between 5 and 6 h after surgery and independent mobility was achieved 13-22 h after surgery. Orthostatic hypotension, nausea, and vomiting were occasionally associated with standing for the first time, but other side effects were unremarkable. 230 (71%) of the 325 patients were discharged directly home after a single overnight stay in hospital. INTERPRETATION: Local infiltration analgesia is simple, practical, safe, and effective for pain management after knee and hip surgery.

The new generation short-stem hip implants are designed to encourage physiological-like loading, to minimize stress-strain shielding and therefore implant loosening in the long term. As yet there are no long-term clinical studies available to prove the benefits of these short-stem implants. Owing to this lack of clinical data, numerical simulation may be used as a predictor of longer term behaviour. This finite element study predicted both the primary stability and long-term stability of a short-stem implant. The primary implant stability was evaluated in terms of interface micromotion. This study found primary stability to fall within the critical threshold for osseointegration to occur. Longer term stability was evaluated using a strain-adaptive bone remodelling algorithm to predict the long-term behaviour of the bone in terms of bone mineral density (BMD) changes. No BMD loss was observed in the classical Gruen zones 1 and 7 and bone remodelling patterns were comparable with hip resurfacing results in the literature.

Abstract Pharmaceutical drugs for the treatment of metabolic bone diseases lead to a number of side effects due to the their uncontrollable dispersion throughout the body. Therefore, many groups directed their research to develop devices that are targeted to specific organs or tissues and release the encapsulated drug in a highly regulated way. The development of completely resorbable bone‐filling biomaterials delivering drugs would offer a therapeutic approach of drug release and bone augmentation in a simple one‐step process. The biomaterials selected needs custom designs, to control the quantity and the duration of drug release and at the same time inducing desirable host cell responses and preventing bacterial infection. Current synthetic biomaterials produced as drug delivery microspheres due to production difficulties contain not very well designed interconnected pores and fail to fill these pertinent requirements. Turning directly to nature such as marine structures for inventive solutions can help to solve these problems due to their structure, chemistry and architecture and their unique designs. We demonstrate ‐for the first time‐ the potential of unique coral shells with specific microspherical structure and highly organised interconnected intra‐pore designs to offer a number of desired functions for targeted delivery of Bisphosphonate (BP) (paminodrate) and an antibiotic (Gentamicin) for bone regeneration, repair and preventive antibacterial slow drug delivery.

AIMS: The aim of this study was to report the implant survival and patient-reported outcome measures (PROMs) in a consecutive series of patients aged less than 50 years at the time of arthroplasty using the Birmingham Hip Resurfacing system (BHR), with a minimum follow-up of ten years. PATIENTS AND METHODS: A total of 226 patients with osteoarthritis of the hip, who underwent BHR and presented to a single surgeon, were included in the study. Survival of the implant was confirmed by cross-checking with the Australian Orthopaedic Association National Joint Replacement Registry. Kaplan-Meier survival curves with 95% confidence intervals (CIs) were constructed. Pre- and postoperative PROMs were compared with t-tests, and postoperative scores were compared using anchor analysis with age and gender matched normative data. RESULTS: At median follow-up of 12 years (interquartile range (IQR) 10 to 13), six BHRs were revised, with a cumulative rate of survival of 96.8% (95% confidence interval (CI) 94.2 to 99.4) at 15 years, and with a significantly lower (p = 0.019) cumulative rate of revision than the national average for the same device at ten years. Most revisions (n = 4) were undertaken early, less than three years postoperatively, and occurred in women. Patient-reported general health (Veteran's Rand-36), disease state (Western Ontario and McMaster Universities Osteoarthritis Index), function (modified Harris Hip Score) and level of activity (Tegner activity score) maintained significant (p < 0.01 for each) improvements beyond ten years postoperatively and were equal to, or exceeded, age- and gender-matched normative data in more than 80% of the patients. CONCLUSION: Longer term PROMs after BHR, from a single surgeon, for patients aged less than 50 years remain under-reported. We found that the outcome after a BHR, at a minimum of ten years postoperatively, remained satisfactory, particularly for self-reported hip function.

This study evaluates methods of sterilizing contaminated bone-tendon autografts using 10% povidone-iodine solution. Sterile grafts were prepared from human cadavers. Grafts were immersed in a suspension of either Staphylococcus aureus or Pseudomonas aeruginosa, and three sets of sterilization experiments were performed in 10% povidone-iodine for 30 minutes: one each with S. aureus and P. aeruginosa by static soaking and a third with S. aureus by serial washing with agitation. Of grafts inoculated with S. aureus, six of six grew the test organism after soaking at room temperature, as did five of six after soaking at 36 degrees C and also eight of nine after washing with agitation. Of grafts inoculated with P. aeruginosa, five of six grew the test strain after soaking at room temperature, as did six of six after soaking at 36 degrees C. Thirty minutes of exposure to aqueous 10% povidone-iodine does not adequately sterilize an inoculated graft.