Aims

Total knee arthroplasty (TKA) is a common and safe orthopaedic procedure. Zimmer Biomet's NexGen is the second most popular brand of implant used in the UK. The primary cause of revision after the first year is aseptic loosening. We present our experience of using this implant, with significant concerns around its performance with regards early aseptic loosening of the tibial component.

Abstract. Introduction. OtisMed Shape Match ® patient specific implant cutting jigs were designed to place TKA in kinematic alignment (KA) rather than traditional mechanical alignment (MA). This product was withdrawn from the market in 2013. It has been hypothesised that KA might lead to early implant failure. Initial evidence has not supported this. We present 10 year outcome data for the largest single centre cohort to date. Methodology. Between 2010 and 2013, 127 Shape Match® TKAs were implanted in 119 individuals. Retrospective review of long leg post-operative radiographs assessed femoral mechanical anatomical angle (FMA), tibial mechanical angle (TMA), hip-knee-ankle angle (HKA), posterior tibial slope (PTS) and femoral component flexion. Oxford Knee Scores (OKS), revision and further surgery rates were reviewed. Results. 4 (3.1%) patients underwent revision for instability, recurrent haemarthrosis, stiffness and infection respectively. In this subgroup, PTS ranged from 9–25° (SD 7.5°). PTS range for non-revision subgroup was 1–23° (SD 4.6). 1 patient with a PTS of 21° had failure of quadriceps tendon, but was not revised. Mean OKS at 1year = 38.1 (SD 1.08), 2 years = 39.3 (SD 1.08), 5 years = 40.8 (SD 4.11). PTS had the largest impact on OKS, with <10° slope conferring a higher OKS. Conclusions. At 10 year follow up, this cohort did identify several cases where excessive PTS was evident. This may have led to revision surgery and contributed post-operative complications. PTS, unlike other alignment measures, impacted OKS results. Overall revision rate and OKS were consistent with registry and other published data

Poor soft tissue balance in total knee arthroplasty (TKA) is one of the most primary causes of dissatisfaction and reduced joint longevity, which are associated with postoperative instability and early implant failure. 1. Therefore, surgical techniques, including mechanical instruments and 3-D guided navigation systems, in TKA aim to achieve optimum soft tissue balancing in the knee to improve postoperative outcome. 2. Patella-in-Place balancing (PIPB) is a novel technique which aims to restore native collateral ligament behaviour by preserving the original state without any release. Moreover, reduction of the joint laxity compensates for the loss of the visco-elastic properties of the cartilage and meniscus. Following its clinical success, we aimed to evaluate the impact of the PIPB technique on collateral ligament strain and laxity behaviour, with the hypothesis that PIPB would restore strains in the collateral ligaments. 3. . Eight fresh-frozen cadaveric legs were obtained (KU Leuven, Belgium, H019 2015-11-04) and CT images were acquired while rigid marker frames were affixed into the femur, and tibia for testing. After carefully removing the soft tissues around the knee joint, while preserving the joint capsule, ligaments, and tendons, digital extensometers (MTS, Minnesota, USA) were attached along the length of the superficial medial collateral ligament (MCL) and lateral collateral ligament (LCL). A handheld digital dynamometer (Mark-10, Copiague, USA) was used to apply an abduction or adduction moment of 10 Nm at fixed knee flexion angles of 0°, 30°, 60° and 90°. A motion capture system (Vicon Motion Systems, UK) was used to record the trajectories of the rigid marker frames while synchronized strain data was collected for MCL/LCL. All motion protocols were applied following TKA was performed using PIPB with a cruciate retaining implant (Stryker Triathlon, MI, USA). Furthermore, tibiofemoral kinematics were calculated. 4. and combined with the strain data. Postoperative tibial varus/valgus stresses and collateral ligament strains were compared to the native condition using the Wilcoxon Signed-Rank Test (p<0.05). Postoperative tibial valgus laxity was lower than the native condition for all flexion angles. Moreover, tibial valgus of TKA was significantly different than the native condition, except for 0° (p=0.32). Although, tibial varus laxity of TKA was lower than the native at all angles, significant difference was only found at 0° (p=0.03) and 90° (p=0.02). No significant differences were observed in postoperative collateral ligament strains, as compared to the native condition, for all flexion angles, except for MCL strain at 30° (p=0.02) and 60° (p=0.01). Results from this experimental study supported our hypotheses, barring MCL strain in mid-flexion, which might be associated with the implant design. Restored collateral ligament strains with reduced joint laxity, demonstrated by the PIPB technique in TKA in vitro, could potentially restore natural joint kinematics, thereby improving patient outcomes. In conclusion, to further prove the success of PIPB, further biomechanical studies are required to evaluate the success rate of PIPB technique in different implant designs

Locking plates have led to important changes in bone fracture management, allowing flexible biological fracture fixation based on the principle of an internal fixator. The technique of locking plate fixation differs fundamentally from conventional plating and has its indications and limitations. Most of the typical locking plate failure patterns are related to basic technical errors, such as under-sizing of the implant, too short working length, and imperfect application of locking screws. After analysis of the fracture morphology and intrinsic stability following fracture reduction, a meticulous preoperative planning is mandatory under consideration of the principles of the internal fixator technique to avoid technical errors and inaccuracies leading to early implant failure

Introduction. Clinical symptoms arising from corrosion within taper junctions of modular total hip prostheses are of increasing concern [1]. In particular, bi-modular implant designs showed increased failure rates due to wear originating from the neck-stem junction [2]. In-vivo corrosion-related failure is less frequently observed for head-stem junctions [3]. It is hypothesized that fretting and crevice corrosion are associated with micromotions between the mating surfaces of a taper junction [4]. The aim of this study was to measure micromotion occurring within a head-stem junction of a conventional prosthesis and clarify by how much it is exceeded in a neck-stem junction of a bi-modular prosthesis that exhibited severe corrosion and early implant failure. Material & Methods. The micromotions within two taper articulations were investigated: a head-stem taper (Corail, DePuy Synthes, Leeds, UK, Figure 1) and a neck-stem taper of a bi-modular THA prosthesis (Rejuvenate, Stryker, Kalamazoo, MI, USA). Both tapers were assembled with 2000 N. Loading at an angle of 50° to the taper axes (identical for both) in direction of the stem axis was incrementally increased from 0 N to 1900 N (n=3). Small windows (< 2.5 mm. 2. ) were cut through the female tapers by electric discharge machining, exposing the male taper surface for direct micromotion measurements by microscopic topographic measurements (Infinite Focus Microscope, Alicona Imaging GmbH, Austria). Subsequently, feature matching of the images from the differently loaded implants was applied (Matlab 2016b, The MathWorks Inc., Natick, MA, USA) to determine the local relative motion between the mating surfaces. Results. Loading with 1900 N resulted in micromotions of 1.0 µm ± 0.1 µm at the head-stem taper (Figure 2). The stepwise loading showed the motion trajectory, suggesting toggling with the dominant displacement in axial direction and small transversal movements. Neck-stem micromotion was significantly higher (14.2 µm ± 1.7 µm, p < 0.001). The trajectory revealed a tilt of the neck in direction of the force. The male taper returned into its initial position after the load was removed, indicating a repetitive rocking motion within every load sequence. Discussion. The higher micromotion at the neck-stem taper junction is likely caused by the larger lever arm (20-fold) between load application and taper engagement. This can serve to explain the susceptibility of bi-modular prostheses to an elevated rate of problems due to fretting corrosion. Similar findings are speculated to apply for large-diameter heads, which showed high failure rates in clinical practice [5]. For any figures or tables, please contact the authors directly

Modifying Knee anatomy during mechanical Total Knee Arthroplasty (TKA) may impact ligament balance, patellar tracking and quadriceps function. Although well fixed, patients may report high levels (20%) of dissatisfaction. One theory is that putting the knee in neutral mechanical alignment may be responsible for these unsatisfactory results. Kinematic TKA has gained interest in recent years; it aims to resurface the knee joint and preservation of natural femoral flexion axis about which the tibia and patella articulate, recreating the native knee without the need for soft tissue relaease. That's being said, it remains the question of whether all patients are suitable for kinematic alignment. Some patients' anatomy may be inherently biomechanically inferior and recreating native anatomy in these patients may result in early implant failure. The senior author (PAV) has been performing Kinematic TKA since 2011, and has developed an algorithm in order to better predict which patient may benefit from this technique. Lower limb CT scans from 4884 consecutive patients scheduled for TKA arthroplasty were analysed. These exams were performed for patient-specific instrumentation production (My Knee®, Medacta, Switzerland). Multiple anatomical landmarks used to create accurate CT-based preoperative planning and determine the mechanical axis of bone for the femur and tibia and overall Hip-knee-Ankle (HKA). We wanted to test the safe range for kinematic TKA for the planned distal resection of the femur and tibia. Safe range algorithm was defined as the combination of the following criteria: – Independent tibial and femoral cuts within ± 5° of the bone neutral mechanical axis and HKA within ± 3°. The purpose of this study is to verify the applicability of the proposed safe range algorithm on a large sample of individual scheduled for TKA. The preoperative tibial mechanical angle average 2.9 degrees in varus, femoral mechanical angle averaged 2.7 degrees in valgus and overall HKA averaged of 0.1 in varus. There were 2475 (51%) knees out of 4884, with femur and tibia mechanical axis within ±5° and HKA within ±3° without need for bony corrections. After applying the algorithm, a total of 4062 cases (83%) were successfully been evaluated using the proposed protocol to reach a safe range of HKA ±3° with minimal correction. The remaining 822 cases (17%) could not be managed by the proposed algorithm because of their unusual anatomies and were dealt with individually. In this study, we tested a proposed algorithm to perform kinematic alignment TKA avoiding preservation/restoration of some extreme anatomies that might not be suitable for TKA long-term survivorship. A total of 4062 cases (83%) were successfully eligible for our proposed safe range algorithm for kinematic TKA. In conclusion, kinematically aligned TKA may be a promising option to improve normal knee function restoration and patient satisfaction. Until we have valuable data confirming the compatibility of all patients' pre arthritic anatomies with TKA long-term survivorship, we believe that kinematically alignment should be performed within some limits. Further studies with Radiostereometry or longer follow up might help determine if all patients' anatomies are suitable for Kinematic TKA

Summary. Biomechanically, a 2° screw deviation from the nominal axis in the PFLCP leads to significantly earlier implant failure. Screw deviation relies on a technical error on insertion, but in our opinion cannot be controlled intraoperatively with the existing instrumentation devices. Background. Several cases of clinical failure have been reported for the Proximal Femoral Locking Compression Plate (PFLCP). The current study was designed to investigate the failure mode and to explore biomechanically the underlying mechanism. Specifically, the study sought to determine if the observed failure was due to technical error on insertion or due to implant design. Methods. To exclude patient and fracture type related factors, an abstract foam block model simulating an unstable pertrochanteric fracture was created for three study groups with six specimens each (n=6). Group 1 was properly instrumented according to the manufacturer's guidelines. In Group 2 and 3, the first or second screw was placed in a posterior or anterior off-axis orientation by 2° measured in the transversal plane, respectively. Each construct was tested cyclically until failure using a test setup and protocol simulating complex axial and torsional loading. Radiographs were taken prior to and after the tests. Force, number of cycles and failure mode were compared. Results. The 2° screw deviation from the nominal axis led to significantly earlier construct failure in Group 2 and 3. The failure mode consisted of loosening of the off-axis screw due to disengagement with the plate, resulting in loss of construct stiffness and varus collapse of the fracture. Conclusions. In our biomechanical test setup, a screw deviation of only 2° from the nominal axis consistently led to the failure mode observed clinically. In our opinion, screw deviation mostly relies on technical error on insertion. But, proper screw insertion may be difficult or impossible with the existing instrumentation devices, especially as it cannot be controlled or guaranteed intraoperatively

Introduction:. Prompted by the success of hip and knee arthroplasty, total ankle replacement (TAR) has become increasingly popular as a treatment for end stage arthritic complaints of the ankle. Glazebrook et al proposed a three grade classification of complications to assist prediction of early implant failure. We have compared the experience of a tertiary referral centre in the UK to Glazebrook's proposed system. Method:. A retrospective review of the Sheffield Foot and Ankle Unit TAR database was performed from 1995 to 2010. All complications were recorded and categorised using Glazebrook's proposed system. Glazebrook described eight main complications of increasing severity. Low grade complications; Post operative bone fracture, Intra-operative bone fracture and wound healing problems were very unlikely to lead to revision. Medium grade complications; technical error and subsidence, lead to failure < 50% of the time. High grade complications; deep infection, aseptic loosening and implant failure lead to revision > 50% of the time. Results:. 217 TAR were implanted in 198 patients with a minimum follow up of 30 months. The complication rate was 23% with a revision rate of 17%. All complications recorded in our study except intraoperative bone fracture and wound healing had a failure rate of at least 50%. Conclusion:. The proposed classification system of Glazebrook et al was the first step towards an international system of classifying TAR complications. Most complications associated with TAR have a significant impact on the lifespan of a TAR. Glazebrook et al's proposed three tier system did not reliably reflect our experience. We would categorise complications as either high or low risk for early failure of TAR

Aims

The aim of this study was to determine whether obesity had a detrimental effect on the long-term performance and survival of medial unicompartmental knee arthroplasties (UKAs).

A technical goal in total knee arthroplasty is the production of a neutral coronal plane mechanical axis. Errors may produce large mechanical axis deviations precipitating early implant failure. This study sought to test if measured distal femoral resection produced more accurate and consistent coronal alignment than arbitrarily set distal femoral resection. Data from a cohort of 255 consecutive unselected primary total knee arthroplasties undertaken by the senior author (PM) was collected prospectively and independently assessed. In the first 167 cases distal femoral resection was arbitrarily set to 5 degrees of valgus. In the remaining 88 cases the distal femoral resection angle was determined on a preoperative long leg standing AP radiograph. Postoperative coronal alignment was measured on long leg standing AP radiograph in all cases. The measured distal femoral valgus angle was between 4 and 7 degrees. An equal number measured either 5 or 6 degrees and accounted for 85% of the total number. Statistically insignificant improvements in mean axis and standard deviation were observed in the measured group: mean axis deviation −0.31 vs −0.51: p=0.17 (independent samples t test) and standard deviation 0.91 vs 1.09: p=0.055 (Levene test). Acceptable coronal alignment in total knee arthroplasty can reliably be obtained with conventional instrumentation. Improvement in standard deviation with measured distal femoral valgus angle approaches statistical significance

Aims: Early bone ingrowth is known to increase primary implant þxation and reduce the risk of early implant failure. RGD peptide (Arg-Gly-Asp) has been identi-þed as playing a key role in osteoblast attachment and proliferation on various surfaces. The aim of this study is to test whether a monolayer of RGD peptide on Ti implants will increase bone ingrowth in vivo. Methods: Controlled canine study (n=8). 6 x 10mm plasma sprayed porous coated implants (Ti6Al4V) was inserted as press-þt in the proximal tibia bilaterally. Observation period was 4 weeks. Implants was coated in a 100 μM solution of cylic (RGDfK) peptide for 24 hours (Biomet-Merck, Darmstadt, Germany). Two dogs had to be excluded due to wrong placement of the implants. Results are presented as median and range. Results: A signiþcant increase in bone/implant contact was seen for the RGD treated group (p< 0.05). Bone fraction at the interface was 0.18 (0.10–0.45) compared to 0.09 (0.05–0.14) for the control. Mechanical þxation, measured by push-out test, was increased. Shear strength was 85% higher for the RGD group; however this difference was not signiþcant. Conclusions: This study shows that implant surface treatment with RGD enhances early bone ingrowth to press-þtted implants. However, future studies will be preformed regarding coating integrity and long-term effects, as well as its performance under loaded conditions

Purpose: The purpose of this paper is to present a novel technique of anterior fixation of unstable pelvic fractures which is minimally invasive, biomechanically suitable, easy to apply, and uses readily available spinal implants. Method: Eighteen consecutive patients with unstable pelvic fractures (AO type A-12 patients and type B-6 patients) underwent stabilization using the novel technique of fixation and were included in the study. Two trauma trained orthopedic surgeons performed all the procedures. All patients were evaluated clinically and with imaging studies that included antero-posterior, inlet and outlet radiographs and a CT scan. At surgery the posterior instability was addressed first with iliosacral screw fixation following reduction of the fracture in a standard fashion. A 2–3cm longitudinal incision was then made over the anterior inferior iliac spine bilaterally to obtain a starting point in the supra acetabular region. Pedicle screws of size 7mm or 8mm x 80mm (Synthes Spine Paoli, USA) were then placed in the supra-acetabular position under fluoroscopic guidance. A pre-contoured 6mm titanium rod with a bow was then tunneled subcutaneously to connect the screws. Care was taken to place the rod just below the lower abdominal crease to prevent pressure on the bowel or vascular structures. The implants were compressed using standard compressors and C-rings. Patients were followed until the pelvis fracture healed as documented on X-rays and clinical exam. Results: Patients were followed for a minimum 6 months (range 6–12 mo). All patients healed by 3 months (similar to our prior experience using other methods). Complications included: 2 deaths in poly trauma patients unrelated to the pelvic procedure; 2 patients with transient lateral femoral cutaneous nerve palsy (one on each side), and one early implant failure due to a surgical technical error that was re-operated the next day. Conclusion: Disruptions of the pelvic ring are complex injuries and should be managed on a case specific basis. By employing the established principles of supra-acetabular fixation, this technique allows for minimally invasive, definitive internal anterior fixation. The potential complications of pin tract infection and a cumbersome external appliance associated with external fixation are avoided with this technique and better patient acceptance is achieved

Purpose: To evaluate the outcome of the Elite Plus femoral stem in multiple surgeons’ hands at a minimum of three years post implantation, in accordance with guidelines published by the National Institute for Clinical Excellence. Methods: Between March 1994 and March 1998, 199 patients underwent 224 primary total hip replacement procedures using the Elite Plus femoral stem at the Glenfield Hospital, Leicester. Seven different Consultant Orthopaedic Surgeons implanted these stems during this period. Patients were reviewed at a mean of 4.75 years following surgery using the Oxford Hip Score and plain radiographs. The mean age at operation was 62.3 years. Between March 1994 and March 2001, 12 patients underwent re-operation for all reasons, and 13 died. Oxford Hip Scores were returned from 159 patients (177 stems; 88.9%) and an AP and lateral radiograph obtained on 145 patients (162 stems; 81.4%). Results: There were five known revision procedures for aseptic loosening (5/224; 2.2%). The mean Oxford Hip Score was 24 (range 10–54). Radiological assessment revealed gross failure in a further 11 femoral stems (11/162; 6.8%), and adverse radiological features in a further 28 stems (28/162; 17.3%). Discussion: In the ‘best case’ scenario, a combined revision and radiographic failure rate of 9% is higher than expected. Antero-posterior positioning of the stem, resulting in bony cortical contact, appeared to produce a characteristic progressive osteolytic lesion which resulted in early implant failure. Additional possible modes of failure are discussed

Background. Titanium, in particular Ti6Al4V, is the standard material used in cementless joint arthroplasty. Implants are subjected to cyclic loading where fracture is the reason for re-operation in 1.5–2.4% of all revisions in total hip arthroplasty. In order to strengthen critical regions, surface treatments such as shot peening may be applied. A superficial titanium oxide layer is naturally formed on the surface as a protective film at ambient conditions. However, as its thickness is only in the range of several nanometers, it is prone to be destroyed by high loads - as present at the surface during bending - leading to an ‘oxidative wear’ in a corrosive environment [1]. The present study aims to evaluate the shot peening treatment on Ti6Al4V regarding its potential for cyclically loaded parts under a dry and a corrosive testing medium. Materials and Methods. Hour-glass shaped titanium specimens (Ti6Al4V) with a minimal diameter of 10 mm have been subjected to an annealing treatment at 620°C for 10h to remove initial residual stresses introduced during machining. Subsequently, a high-intensity shot peening treatment with cut wire followed by a low-intensity cleaning process with glass beads have been performed (Metal Improvement, Germany). Arithmetic mean roughness R. a. of the treated surfaces was measured (Mahr Perthometer M2, Germany). Residual stress depth profiles prior to and after shot peening have been measured by a Fe-filtered Co-K(alpha) radiation (GE Measurement&Control, USA) and calculated using the sin. 2. (psi) method. Fatigue strength has been determined by two servo-hydraulic hydropulsers (Bosch Rexroth, Germany) at 10 Hz and a load ratio of R=0.1 either under dry conditions (8 specimens) or surrounded by a 0.9-% saline solution (6 specimens) (BBraun, Germany) (Fig. 1). Testing has been performed until fracture occurred or the total number of 10 × 10. 6. cycles has been reached. All fracture surfaces have been analyzed after testing using FEG-SEM (Zeiss LEO 1530 VP Gemini, Germany). Results. Surface roughness increased significantly (p<0.01) after shot peening treatment from R. a, annealed. = 0.24 μm (±0.09 μm) to R. a, peened. = 2.02 μm (±0.16μm). Residual stresses have been introduced during shot peening up to a depth of 200μm with a maximum of 870 MPa at the surface (Fig. 2, left). All specimens showed clear signs of fatigue fracture after failure. Regarding fatigue strength, no differences have been observed between testing in saline solution or a dry environment (Fig. 2, right). Discussion. Shot peening has shown to significantly increase fatigue strength of a Ti6Al4V alloy after testing up to 10 × 10. 6. cycles. Thus, it seems to be an appropriate treatment for highly loaded components in cementless joint arthroplasty. In this context, a corrosive environment around a cyclically loaded implant does not seem to have any influence on their long term mechanical behaviour. However, it still needs to be clarified to which extend shot peening might decrease the risk of an early implant failure due to micro-motion between assembled parts (fretting) [2]

Total hip replacement procedures provide a very effective treatment modality for a wide range of diseases and injures to joints. The annual number of primary and surgeries has been increasing. In Region Emilia Romagna, 4000000 inhabitants, 4587 total hip replacements (THA) were performed in 1997 and the number raised up to 5410 in 2002 ( + 18%). Emiarthoplasties were respectively 1914 and 2215 (+ 16%). Parallely number of revision raised from 550 to 938 (+71%). In 2003 incidence of primary THAs in Emilia-Romagna is 107/100.000 inhabitants, higher than mean national value (76/100000). Data of both primary and revision surgeries are collected by RIPO (Register for Orthopaedic Prosthetic Implantology) that started its activity in Rizzoli Institute on January 1990 and in Regione Emilia-Romagna on January 2000. The recording of data is done for each joint replacement operation and it consists on the identification of the patient, information about diagnosis or reason for re-operation, surgical approach, antibiotic and antithromboembolic prophylaxis, perioperative complications. Acetabular, femoral and head components are separately registered, on the basis of stickers with catalogue numbers provided by manufacturers with the implants. Fixation of the components is recorded as well. Among the purposes of the Register there are the identification of early prosthesis failures, the information of surgeons on the outcome of their patients, the creation of a benchmarking tool for consultants and the speedy identification of relevant patients if a particular prosthesis or a particular batch gives cause for concern. As for Scandinavian registers, revision is used as an end-point in the analyses. On this basis it is possible to calculate survival curves either aggregated or stratified. By Cox multivariate analysis it has been ascertained that risk factors in total hip arthroplasties are represented by sex (females have lower risk than males), by age (younger than 40 are more at risk than 40–70s, and older than 70 are less at risk than 40–70s) and by pathology (fracture, coxites and Paget diseases have higher risk than coxarthrosis). Basing on these data, survival analysis was normalized and the influence of articular coupling and fixation of the components on prosthesis outcome have been evaluated. It resulted that failures are more likely to occur when metal on metal, or metal on polyethylene or ceramic on polyethylene devices rather than ceramic on ceramic implants are implanted. Similarly cemented and hybrid THAs fail at higher rate than uncemented ones. All data are referred to a 11 years follow-up. At present time Kaplan Meier analysis indicates a survival rate of total hip arthroplasties performed at Istituto Rizzoli of nearly 90% at ten years follow-up (9717 primary implants, 435 failures). Main reasons for revisions are aseptic loosening of the cup (33%),aseptic loosening of both components (18%), aseptic loosening of the stem (17%), deep infection (7.9%),dislocation (7.6%),prosthesis fracture (3%) etc. Aseptic loosening represent, therefore, the most frequent cause for revision. Results obtained at Istituto Rizzoli fit in the benchmarking set by the British NICE (National Institute for Clinical Excellence) that states that the revision rate should be of 10% or less at 10 years. To improve these results attention should be pointed on new models: hip prosthesis technology is continually changing, with new designs and techniques being introduced. There is a need to strike a balance between using prostheses with published long-term performance data, and the need to develop and improve hip prosthesis. A solution to this problem could be to entrust reference clinical centers the evaluation of the effectiveness of any new prosthesis for at least three years, before opening free distribution in standard orthopaedic units,as suggested by NICE. Only models that reach the ‘entry benchmark’ in adequately sized, well conducted observational studies, can be implanted with a good safety. At present time it is unlikely that clinical evaluation data on long term effectiveness is required by Notified Body for ‘CE’ marking, unless new materials are involved in the manufacture. This happens despite the fact that even small changes to existing prostheses can have a significant impact on implant performance and revision rate. Other factors than the already discussed can influence the surgery outcome, and among these the volume of operations performed in the hospital, the ability of the surgeon and its confidence with the technique, the compliance of the patient. Only an overall view of the situation will allow to reach the goal of reduction of need for revision of total hip arthroplasties

The October 2014 Wrist & Hand Roundup360 looks at: pulsed electromagnetic field of no use in acute scaphoid fractures; proximal interphalangeal joint replacement: one at a time or both at once; trapeziometacarpal arthrodesis in the young patient; Tamoxifen and Dupytren’s disease; and endoscopic or open for de Quervain’s syndrome?