Aims

The interest in unicompartmental knee arthroplasty (UKA) for medial osteoarthritis has increased rapidly but the long-term follow-up of the Oxford UKAs has yet to be analysed in non-designer centres. We have examined our ten- to 15-year clinical and radiological follow-up data for the Oxford Phase III UKAs.

Introduction: The effect of different temperatures to antibiotics is unknown. What is the dose-response curve of bone chips impregnated with different kinds of antibiotics?

Material and Methods: Five different antibiotic pills and solutions (cefazolin, clindamycin, linezolid, oxacillin, vancomycin) were stored at −80°C, −20°C, 4°C, 20°C and 37°C. Also, bone chips were impregnated with cefazolin and vancomycin solution and were stored at −80°C and −20°C. After 1 month, 6 months and 1 year, reaction of the antibiotics to Staphylococcus epidermidis was measured using an inoculated iso-agar. Activity of the antibiotics was measured as the diameter of the Staphylococcus epidermidis-free zone.

Also, five cefazolin and vancomycin solutions were used to impregnate bone chips and to make dose-response curves. Furthermore, 1 gram bone chips was impregnated with 5ml cefazolin or 5ml vancomycin solution.

Results: A decrease of the diameter free zone Staphylococcus epidermidis was seen when oxacillin and cefazolin solutions were stored at 37°C for 1 month and when vancomycin was stored for 6 months (37°C). Also, when cefazolin and oxacillin solutions were stored at 20°C, a decrease was noticed. The storage of other antibiotic solutions, pills and bone/antibiotics composite showed no differences in reaction. Dose-response curves show that with increasing antibiotic quantity, diameter free zone increases according to a logarithmic function.

Conclusion and discussion: With the dose-response curve the optimal concentration(s) for local application can be determined. It gives the opportunity to determine the amount of antibiotics present in the patient locally. Freezing of antibiotics does not affect the activity of the investigated antibiotics.

Introduction: Since January 2008 a large set of parameters of each hip fracture patient admitted to the RdGG hospital, were documented prospectively. This documentation was repeated by a written survey 3 months and 1 year after the fracture.

Our research goal was to determine the percentage of patients returning to their living situation prior to their fracture.

Methods: From 1-1-2008 to 1-3-2009, 339 hip fracture patients were treated, 244 female, 95 male. Average age was 78.1 (21–101). ASA distribution showed 240 ASA I/ II patients and 99 ASA III/IV patients. Conservative treatment was chosen in 7 patients, 213 were treated with an osteosynthesis and 117 with a (hemi)-arthroplasty. All patients received a survey regarding their living situation 3 and 12 months after their hip fracture.

Results: 327 patients could be analyzed as the pre fracture living situation of 12 patients was unknown; 71% lived independently, 21% in a care home and 9% in a nursing home. The follow-up (FU) of the living situation of the first two groups was analyzed.

Patients living independently: 45% was discharged directly to their own home, 24% to a nursing home and 3% to a care home. A special rehabilitation unit within our hospital, the “Herstel Unit”, received 28% of patients for further recovery. Patients could rehabilitate here for a maximum of 4 weeks before going home. After 3 months 84% of the patients had returned to their independent living situation, 11% lived in a nursing home and 5% in a care home. This analysis is done in 184 patients as 12 had died and 35 were lost to FU. After 12 months 38 (84%) of 45 still lived independently, 4 went to a nursing home, 3 to a care home, 21 died and 4 were lost to FU.

Care home patients: 47% was discharged directly to their care home, 15% to the “Herstel Unit” and 37% to a nursing home. At 3 months 69% of the patients had returned to their care home, 31% lived in a nursing home. Analysis is done in 45 patients as 15 had died and 8 were lost to FU. 12 months FU is accomplished in 27 patients of whom 19 died, none lost to FU; 88% lived in a care home, 12% in a nursing home.

Conclusions: More than 80% of the pre operative independently living patients have returned to their own independent living situation within 3 months. At 1 year FU this percentage is steady. 52% of this population stayed briefly on an alternative location for further recovery. The patients living in a care home have stayed longer on an alternative location, but more than 90% of them have returned to their pre fracture living situation at 12 months FU.

Our results challenge the prejudice that hip fracture patients live or end up living in a nursing home. These data can be used to calculate the amount of specific discharge locations needed in the near future.

Background: One of the disadvantages of the Impact Factor (IF) is self-citation. The SCImago Journal Rank (SJR) indicator excludes self-citations and incorporates quality of citations that a journal receives by other journals, rather than absolute numbers. This study re-evaluated self-citation influence on the 2007 IF for 17 major orthopaedic journals and the difference in ranking using IF or SJR was investigated.

Methods: Divided in a general (n = 8) and specialized (n = 9) group, all journals were analysed for self-citation rate, self-cited rate and citation density. Rankings of the 17 journals for IF and SJR were determined and the difference in ranking was calculated.

Results: Specialized journals had higher self-citation rates (p = 0.05), self-cited rates (p = 0.003) and lower citation-densities (p = 0.01). Both groups correlated for self-citation rate and impact factor (general: r = 0.85 ; p = 0.008) (specialized: r = 0.71 ; p = 0.049).

When ranked for SJR instead of IF, five journals maintained rank, six improved their rank and six experienced a decline in rank. Biggest differences were seen for BMC MD (+7 places) and CORR (− 4 places). Group-analyses for the IF (general: 7.50 – 95%CI 3.19 to 11.81) (specialized: 10.33 – 95%CI 6.61 to 14.06) (p = 0.26), SJR (general: 6.63 – 95%CI 2.66 to 10.60) (specialized: 11.11 – 95%CI 7.62 to 14.60) (p = 0.07) and the difference between both rankings (general: 0.88 – 95%CI –1.75 to 3.50) (specialized: − 0.78 – 95%CI –2.20 to 0.65) (p = 0.20), showed an enhanced underestimation of sub-specialist journals.

Conclusion: Citation analysis shows that general journals tend to use more citations per published article and a larger portion of self-citations constitutes citations of sub-specialist journals compared to more general journals. The SJR excludes the influence of self-citation and awarded prestige by the SJR implies a different quality-evaluation for most orthopaedic journals. A disadvantage using this indicator, is an enhanced effect of underestimation of sub-specialist journals.

The anterior supine intermuscular (ASI) approach enables total hip arthroplasty (THA) without dissection of muscles or insertions. This could be beneficial in patient recovery and satisfaction. Study-aim was to assess the learning-curve for the ASI-approach and show short-term results.

Two surgeons performed uncemented THA on 23 (17 and six respectively) consecutive patients. The Taperloc stem, Recap-cup and Magnum head (Biomet, Warsaw, USA) were used. THA was performed without the use of a traction-table. Data was gathered till 3 months follow-up.

Average patient age was 61 years (36–74), ASA-classification was two (one-four). There was a decrease in surgical time from 140 at the beginning to 80 minutes at the end of our series. Average blood-loss was 788 ml. Three patients received erythrocyte-transfusion. Minor non-orthopaedic complications all resolved within 48 hours. Average length of stay was five-and-a-half days. Functional score-lists showed improvement comparing pre-operative scores with scores on 12 weeks follow-up: Harris-Hip-Score from 56 to 94, Oxford-Hip-Score from 43 to 19, Hip-disability-and-Osteoarthritis-Outcome-Score from 109 to 18. On six weeks follow-up 65% and on 12 weeks 100% of patients showed unaided mobilisation. At follow-up we saw one superficial wound-infection, one partial non-disabling sartorius-lesion, one paraesthesia and one transient anaesthesia of the lateral femoral cutaneous nerve area.

ASI-approach for uncemented THA showed good results and rapid patient-mobilisation. This may in part be due to the non-dissecting of muscles or insertions, thus non-compromising the propriocepsis. Off course tissue-damage occurs, though this is likely to be of a fast reversible nature. There were no serious adverse events. We saw a rapid decline in session-duration suggesting a moderate learning-curve. Further research will have to prove the beneficiality of the ASI-approach.

Aseptic loosening of the total TMC joint prosthesis occurs frequently and may depend on the design of the prosthesis. Numerous TMC prosthesis designs are available, and new designs are being developed and tested. One of the problems in the clinical studies of TMC prostheses is identifying and predicting prosthetic loosening at an early stage. Roentgen Stereophotogrammetric Analysis (RSA). allows assessment of three-dimensional micromotion of orthopaedic implants with high accuracy. Early micromotion (in the first two postoperative years) of most prostheses is strongly correlated with the development of aseptic loosening. We studied if RSA assessment was possible after total TMC joint arthroplasty.

In five cadaveric hands the TMC joint was replaced by the SR-TMC prosthesis. Tantalum beads of 0.8 mm were implanted in the trapezium and first metacarpal bone without extending the standard surgical exposure. The metacarpal prosthesis component was provided with 0.5 mm beads. A three-dimensional surface model of the trapezium component of the SR-TMC prosthesis was prepared to facilitate model-based RSA. After the surgical procedure, RSA radiographs were made of all hands in two commonly used positions for imaging of the TMC joint. The number of visually detected markers for each bone/implant was recorded. Of one cadaver hand, RSA radiographs were made in ten different positions to calculate the measurement error of the performed technique.

For the metacarpal bone, all beads were visible in all positions and both (L+R) RSA radiographs. For beads in the polyethylene metacarpal prosthesis component three beads seem sufficient, however in exceptional cases the most proximal placed bead might be invisible due to overprojection by the metal trapezium prosthesis component. Therefore the X-rays should be carefully checked at the radiology department before the patient leaves the ward. Alternatively, an extra bead can be placed in the prosthesis, although this is a lesser option due to possible weakening of the component caused by the placement of the beads. The use of different sizes of beads (0.5/0.8 mm) in the metacarpal bone and metacarpal prosthesis made the interpretation for the analyser easier

The accuracy analysis is currently carried out. First results of these measurements are promising and placement of tantalum beads for RSA analysis during TMC-joint replacement seems feasible.