Aims

This multicentre retrospective observational study’s aims were to investigate whether there are differences in the occurrence of radiolucent lines (RLLs) following total knee arthroplasty (TKA) between the conventional Attune baseplate and its successor, the novel Attune S+, independent from other potentially influencing factors; and whether tibial baseplate design and presence of RLLs are associated with differing risk of revision.

Aims

Patients with proximal femoral fractures (PFFs) are often multimorbid, thus unplanned readmissions following surgery are common. We therefore aimed to analyze 30-day and one-year readmission rates, reasons for, and factors associated with, readmission risk in a cohort of patients with surgically treated PFFs across Austria.

Aims

The aim of this prospective study was to assess the long-term clinical, radiological, functional, and quality of life (QoL)-related outcome of patients treated with the synthetic Ligament Advanced Reinforcement System (LARS) device for anterior cruciate ligament (ACL) rupture.

Aim

Bone loss is a severe problem in septic revision total knee arthroplasty (RTKA). The use of porous coated metaphyseal sleeves is a promising treatment option for extended bone defects. The currently published mid-term results remain limited and no study has been focused exclusively on septic cases. Our aim was to determine the implant survivorship (with special focus on osseointegration) and the clinical and radiological mid-term outcome of metaphyseal sleeve fixation in septic RTKA surgery (minimum follow-up of 2 years).

Aim

One of the most challenging problems in total knee arthroplasty (TKA) is periprosthetic infection. A major problem that arises in septic revision TKA (RTKA) are extended bone defects. In case of extended bone defects revision prostheses with metaphyseal sleeves are used. Only a few studies have been published on the use of metaphyseal sleeves in RTKA - none were septic exclusive. The aim of our study was to determine the implant survival, achieved osseointegration as well as the radiological mid-term outcomes of metaphyseal sleeve fixation in septic two-stage knee revision surgery.

Introduction

Insufficient arthroscopic cuff tear reconstruction leading to massive osteoarthritis and irreparable rotator cuff tears might be salvaged by implantation of an inverted total shoulder prosthesis Delta in the elderly. However, despite the generally high success rate and satisfying clinical results of inverted total shoulder arthroplasty, this treatment option has potential complications. Therefore, the objective of this study was a prospective evaluation of the clinical and radiological outcome after a minimum of 2 years follow-up of patients undergoing inverted shoulder replacement with or without prior rotator cuff repair.

Introduction: Prosthetic joint infections occur in 1–2 % following total knee replacement. Different options of treatment are described in literature with a lack of data from randomized, controlled trials.

We classified septic revision surgeries following total knee according to a classification published by Mc Pherson. Eradication rate of one stage versus two stage exchange was compared.

Materials and Methods: We included 74 patients who underwent septic revision surgeries following total knee replacement in the years 1998 to 2005. Gender distribution was 42 female and 32 male patients. The mean age at revision surgery was 71 years, at primary implantation mean 68,8 years.

Results: The eradication rate overall was 77 %, in one stage exchange 41.7% and in two stage procedures 86%. Multiple stage revision showed an eradication rate of 75%, necrectomy/debridement 50%, arthrodesis and amputation 100%.

Regarding Mc Pherson’s systemic grades classification the eradication rate for two stage exchanges was 85,7% in group A+B and 60%% in group C. One stage procedures achieved 0% eradication rate in group B and 60% in group C. Regarding Mc Pherson’s local extremity grade classification eradication rates within two stage revisions were 84% in group 2 and 75% in group 3. One stage revision achieved 40% and 0%.

Conclusion: Although two stage revision surgeries achieved better results regarding eradication rates then one stage revision surgery, results were statistically not significant. Reason could be a too small number of included patients for a significant statistical impact. The individual surgical procedure should orientate on the classification published by Mc Pherson.

Objectives: The aim of this study was a clinical and radiological evaluation of 68 shoulders operated with the Delta reverse-ball-and-socket total shoulder prosthesis by the senior author with a mean follow-up of 42 months.

Methods: This is a retrospective study in one consecutive series of 68 shoulders, operated by the senior author, which were clinically assessed using the Constant score for pain, Constant Shoulder Score, Oxford Shoulder Score, UCLA Shoulder rating scale, DASH Score, Rowe Score for Instability and Oxford Instability Score. Radiological evaluation was graded by the classification according to Nerot et al. and complications were analysed according to Goslings and Gouma. Patients were evaluated before surgery and at a mean clinical follow-up of 42 months.

Results: There was a significant improvement in all clinical and stability scores. On the average, the Constant score for pain increased from 4.62 to 11.08 points (p< 0.05); the Constant Shoulder Score from 32.65 to 60.31 (p> 0.05); the Oxford Shoulder Score increased from 32.65 to 60.31 (p< 0.05) and the UCLA Shoulder rating scale increased from 15.08 to 27.42 (p< 0.05). The evaluation of stability showed an increase from 49.42 to 80.19 points in the Rowe Score for Instability and from 22.04 to 37.62 in the Oxford Instability score (p< 0.05). According to the Nerot classification, 65 percent of patients were graded as “0”, 20 percent as “1”, 3 percent as “2”, 6 percent as “3” and 6 percent as “4”. Eight complications occurred in terms of a nerve lesion which was graded according to Goslings and Gouma as “1” once, loosening of the humeral stem which was graded as “2” three times and loosening or fracture of the glenoid component which was graded as “2” in five times. At mean follow-up of 42 months, one patient of this series had died of decrepitude which was graded as “4” and one patient was lost of follow-up.

Conclusions: We summarize, that there were significant advantages identified in terms of the Constant score for pain, all clinical scores and the instability scores. Radiological analyses showed 85 percent of patients without or with a small notch only. On the other hand, the rate of complications should be taken into account. We conclude that shoulder arthroplasty with the Delta prosthesis shows significant benefits in terms of less shoulder pain, a higher stability and a gain of range of motion but on the other hand, we emphasize that this treatment remains a salvage procedure in the elderly only.

In recent years UHMWP sutures have gained more and more popularity in shoulder surgery. They have an increased tensile strength but were shown to have a higher rate of knot slippage due to their smooth surface. There exist different testing protocols on suture testing in dry or in wet conditions.

The purpose of this study was to gain some inside as to whether or not the knot security of sliding and non-sliding knots with different suture materials is influenced by dry or wet testing conditions.

We tested five common suture materials, all of them USP #2. The PDSII, the Ethibond and three ultra high molecular weight polyethylene (UHMWPE) sutures: Fiber Wire, Orthocord and Herculine. As non-sliding knots we used Square knot and Revo knot and for sliding knots we used Fisherman and Roeder knot. 10 samples of each knot type were tested. In the first group knot tying and biomechanical testing were performed under dry conditions. In the second group the sutures were soaked in saline solution for 3 min. before knot tying and afterwards tested in saline bath. Cyclic loading was performed to simulate the physiological conditions. We started with a tensile load of 25 N. After 100 cycles, the load was increased to 50 N for another 100 cycles. Until suture rupture or knot slippage of 3 mm the tensile load was gradually increased by 25 N per 100 cycles. Under dry conditions 170 suture ruptures and 30 knot slippages were recorded. Under wet testing conditions 186 suture ruptures and 14 knot slippages were seen, which tested statistically significant. Failure by knot slippage (n=44) was seen under dry and saline testing conditions mainly with UHMWPE sutures particularly with Herculine suture. Knot slippage occured only with sliding knots. With the Ethibond suture no knot slippage was found regardless of the testing conditions and applied knot type. Across all knot types the UHMPE-sutures were significantly stronger in ultimate load to failure than Ethibond and PDSII under dry and wet testing conditions.

Is the information we get from testing dry suture material reliable and helpful for our daily practice? Our study clearly showed: No! The mode of failure and the number of knot-failure differs significantly in wet testing conditions compared to dry testing. We found that the number of knot-failures is higher when tested with dry sutures than in wet testing conditions. The soaking of the suture material with fluid improves its “skid-resistance”. As we expected showed the UHMWP sutures with their smooth surface a high number of knot-failures compared to polyethylen suture Ethibond, which did not show a single knot-failure in dry or wet tesing conditions. The maximum failure load showed clearly the superiority of the new UHMWP suture material, with around 300 N being double as high as for polyethylen and polydioxone sutures.

Crosslinked polyethylene (XPE) was developed to reduce wear in hip and knee arthroplasty. Periprosthetic osteolysis depends on many factors including biological activity of wear particles. This study examines the relative inflammatory effect of different crosslinked polyethylenes compared to ultra-high-molecular-weight-polyethylene (UHMWPE) particles in vivo.

Materials and Methods: Wear particles of 3 XPE- (1 sequential irradiated/annealed; 2 remelted inserts) and 1 UHMWPE-insert were isolated from a knee joint simulator (20nm-nucleopore-filter;acid digestion method;ISO). Particles were analysed by scanning electron microscopy (n=66000). For all groups the particles were smooth, granular, irregular and less fibrillar. More than 85% of the particles were submicron. After removal of endotoxin the particles were suspended in a phosphate buffered saline solution (0.1% vol/vol (particle volume/PBS volume)). Endotoxin levels were controlled using standardised endotoxin detection tests (Lonza) in all samples.

40 female Balb/c mice were randomly assigned to one of five treatment groups (according to the national guidelines of animal protection laws): control (n=8); XPE1 (95 kGy E-beam, remelted; n=8); XPE2 (65 kGy E-beam, remelted; n=8), XPE3 (3x30 kGy Gamma, annealed and sequential irradiated; n=8) and UHMWPE particles (n=8). 50 μl of the particle suspension were injected into the murine left knee under sterile conditions. The leukocyte–endothelial cell interactions and the synovial microcirculation were performed by intra-vital fluorescence microscopy one week after particle injection to assess the inflammatory reaction to the particles (by measuring the rolling fraction of leukocytes, the adherent cells and the functional capillary density (FCD)). Data analysis was performed using a computer-assisted microcirculation analysis system (Cap-Image).

For the statistical analysis the Kruskal-Wallis test was used to determine differences within the groups, followed by an all pairwise multiple comparison procedure with a Bonferoni correction. The level of significance was set at p< 0.05.

Results: The fraction of the rolling leukocytes, adherent cells and FCD increased significantly (p< 0.05) in all bio-materials compared to control group. However, there was no significant difference between the UHMWPE and the XPE particle groups (p> 0.05).

Conclusion: Our data suggest that crosslinked polyethylene wear particles do not lead to a higher inflammatory reaction in vivo compared to UHMWPE particles.

Whereas thermography has already been used as an assessment of disease activity in some kinds of inflammatory arthritis, it is a new method for objektive pain evaluation in patients with joint prosthesis. To our knowledge, no study has tested the correlation between increase of temperature and anterior knee pain with total knee prosthesis yet.

Thirteen patients were included in this study who suffered from anterior knee pain of the retinaculum patellae with total knee prosthesis. The patients were asked to walk 3 km before entering a room which was cooled down to 20 degrees Celsius. A black 1 cm times 4.5 cm square stripe was attached on the diameter of the patella and the patients rested for 20 minutes to cool down before thermographic fotos were taken from 90 degrees, 45 degrees, frontal medial and lateral. The evaluation of temperature difference of each side was performed by marking a 1cm times 2cm square field rectangular around the black stripe and comparing it with a reference point of the same size 3 cm distal of the field. The patients were compared with thirteen others, not suffering from anterior knee pain. Statistical analysis was performed using a t- test and a p value < 0.05 was considered to be significant.

The temperature differences between the rectangular field and the reference point increased significantly on the medial (p= 0.00037) or lateral (p= 0.000002) pain side of the knee. The thirteen knees with knee pain had significantly higher temperature differences between medial and lateral temperature differences, than the knees without knee pain.

We demonstrate a significant correlation between anterior knee pain and an increase of superficial skin temperature around the retinaculum patellae. To our knowledge, this is the first report of an objective assessment of pain of the retinaculum patellae with total knee prosthesis.