Initial experience with Bulgarian Arthroplasty Register.

INTRODUCTION: National arthroplasty registries date back to 1975, when the Swedish Knee Arthroplasty Register was founded. This method of database collecting has since been employed for both patient follow-up and the creation of annual statistical reports. In Bulgaria, there is currently no state-approved software that offers these features.

Treatment of periprosthetic femoral fractures following total hip arthroplasty: results of an online survey of the European Hip Society.

BACKGROUND: Periprosthetic femoral fractures (PPF) are a devastating complication after total hip arthroplasty (THA). Both trauma and adult reconstruction surgeons or combined teams treat these fractures following management algorithms. The aim of this study is to investigate the current treatment of PPF by members of the European Hip Society (EHS). METHODS: An online survey of the members of the European Hip Society (EHS) was conducted. 20 cases of periprosthetic fracture were presented and surgeons were asked to answer questions regarding classification, treatment and postoperative treatment protocol. RESULTS: A total of 132 (130 male; 2 female) EHS members responded. Mean years in surgical practice was 18.8 (min. 1 year; max. 50 years). The preferred surgical method was combined open reduction and internal fixation (ORIF) (30.3%) for AG fractures, ORIF with cables (30.4%) for AL fractures, combined ORIF (cable and plate) for B1 fractures (49.2%), stem revision with cables for B2 fractures (73.1%), stem revision with cables for B3 (55.9%) fractures and combined ORIF (cable and plate: 55.5%) for C fractures. Surprisingly, 10.8% suggested various stem revision techniques for B1 and 17.4% for C fractures. Strong variations were observed regarding postoperative weight-bearing protocol. CONCLUSIONS: A strong consensus was found for the choice of conservative or surgical treatment of the different PPF types according to the Vancouver Classification. Various stem revision techniques were the preferred surgical techniques for Vancouver B2 (91.2%) and B3 (88.6%) fractures. However, for postoperative weight-bearing, when the ORIF technique was used, a significant variation of protocols was found.

Do Modular Dual Mobility Cups Offer a Reliable Benefit? Minimum 5-Year Follow-Up of 102 Cups.

BACKGROUND: Among various options suggested to prevent hip instability after total hip replacement, the MDM-tritanium (modular dual mobility) cup features a cobalt-chrome liner (CoCr) positioned in a titanium acetabular shell and matched with a mobile insert in highly cross-linked annealed X3 polyethylene. The purpose of this study aimed to confirm whether there was no significant release of ions (Co and Cr) or higher occurrence of dislocation or even cases of aseptic loosening of the cementless shell with the use of MDM-tritanium cups at minimum of 5-year follow-up. METHODS: The clinical study was carried out on a homogeneous consecutive and nonselective series with 102 MDM cups (98 patients) implanted in 2 centers. This MDM-tritanium cup had been systematically used for surgical revisions (70% of cases) or for patients with major hip dysplasia or in elderly patients with poor bone quality. A biological assessment of ion releases has been performed in a specific cohort of 39 cases that had an internal ceramic head. RESULTS: None of the following complications was observed: no case of immunoallergic event, no aseptic loosening, and the dislocation rate was 4.9% involving only the difficult primary and revision cases. The clinical results were encouraging, with 89.7 points for Harris Hip Score, 41.16 points/48 for the OHS-12. The Agora Roentgenographic Assessment (ARA) radiologic score was graded "excellent" in 94.4%. The MDM-tritanium survivorship with revision for any cause in 102 cups at 7.95 years was 92.7%. CONCLUSION: Based on the results of our first 102 cases, there were no immunoallergic complications-contrary to what was initially feared with the CoCr bearing-titanium pair-and no postoperative instability, including for complex primary and revisions total hip replacements. LEVEL OF EVIDENCE: Individual Cohort Study: 2B.

French hip resurfacing registry: A study of 1650 cases.

BACKGROUND: Hip resurfacing has been the focus of many evaluations based on international registries but, to date, no prospective studies have evaluated this procedure in France. In 2015, the French Society for Orthopaedics and Traumatology (SoFCOT) and the French Hip and Knee Society concluded an agreement with the French Medicines Agency (ANSM) and French National Health Authority (HAS) to establish an exhaustive observational hip resurfacing registry. The primary objective of this study was to evaluate the hip resurfacing survival rate since the creation of the registry 5 years ago. The secondary objectives were to evaluate the clinical, functional, and radiological outcomes of hip resurfacing and to check the absence of specific complications related to this implant. HYPOTHESIS: The hypothesis was that the registry survival rate was below 0.5% per year. METHODS: Since 2015, data from all patients undergoing hip resurfacing were collected into a monitored database using the software suite OrthoWave. The following were collected for each patient: demographics, anthropometric characteristics, clinical parameters (Postel Merle d'Aubigné score, Harris Hip Score, Oxford Hip Score, and UCLA Activity Score), and radiological findings. Completeness of data collection was checked once a year. RESULTS: In total, 1650 hip resurfacings in 1506 patients (1409 males and 97 females) with a mean age of 50.7 years (range, 17-70 years) were included. Mean follow-up was 3.8 years (range, 2-4.8 years). Mean completeness of data recording was 98.2%. All clinical scores improved significantly. Hip revision was required for 7 (0.4%) complications including 4 femoral neck fractures, 1 aseptic lymphocyte-dominant vasculitis-associated lesion with a large joint effusion, 1 femoral component loosening, and 1 delayed sepsis requiring bipolar removal. At 5 years, the survival rate without hip revision for any cause was 99.6% (95% confidence interval, 99.3-100%). DISCUSSION: The short-term outcomes of patients in the French registry are encouraging in terms of complication and surgical revision rates. The near absence of complications related to metal-on-metal bearing surfaces demonstrates that the criteria used in France (at least 48mm head diameter, use of implants for which long-term data are available, and specific training of surgeons) ensure successful long-term outcomes. LEVEL OF EVIDENCE: II.

Advances and innovations in total hip arthroplasty.

Total hip arthroplasty (THA) has been quoted as one of the most successful and cost-effective procedures in Orthopaedics. The last decade has seen an exponential rise in the number of THAs performed globally and a sharp increase in the percentage of young patients hoping to improve their quality of life and return to physically demanding activities. Hence, it is imperative to review the various applications of technology in total hip arthroplasty for improving outcomes. The development of state-of-the-art robotic technology has enabled more reproducible and accurate acetabular positioning, while long-term data are needed to assess its cost-effectiveness. This opinion piece aims to outline and present the advances and innovations in total hip arthroplasty, from virtual reality and three-dimensional printing to patient-specific instrumentation and dual mobility bearings. This illustrates and reflects the debate that will be at the centre of hip surgery for the next decade.

Dual mobility total hip arthroplasty: should everyone get one?

Hip instability following total hip arthroplasty (THA) remains a major challenge and is one of the main causes of revision surgery.Dual mobility (DM) implants have been introduced to try to overcome this problem. The DM design consists of a small femoral head captive and mobile within a polyethylene liner.Numerous studies have shown that DM implants reduce the rate of dislocation compared to fixed-bearing inserts.Early designs for DM implants had problems with wear and intra-prosthetic dislocations, so their use was restricted to limited indications.The results of the latest generation of DM prostheses demonstrate that these problems have been overcome. Given the results of these studies presented in this review, surgeons may now consider DM THA for a wider patient selection. Cite this article: EFORT Open Rev 2019;4:541-547. DOI: 10.1302/2058-5241.4.180045.

Early experience with dual mobility acetabular systems featuring highly cross-linked polyethylene liners for primary hip arthroplasty in patients under fifty five years of age: an international multi-centre preliminary study.

PURPOSE: To evaluate early performance of contemporary dual mobility acetabular systems with second generation annealed highly cross-linked polyethylene for primary hip arthroplasty of patients under 55 years of age. METHODS: A prospective observational five years study across five centers in Europe and the USA of 321 patients with a mean age of 48.1 years was performed. Patients were assessed for causes of revision, hip instability, intra-prosthetic dissociation, Harris hip score and radiological signs of osteolysis. RESULTS: There were no dislocations and no intra-prosthetic dissociations. Kaplan Meier analysis demonstrated 97.51% survivorship for all cause revision and 99.68% survivorship for acetabular component revision at five years. Mean Harris hip score was 93.6. Two acetabular shells were revised for neck-rim implant impingement without dislocation and ten femoral stems were revised for causes unrelated to dual mobility implants. CONCLUSION: Contemporary highly cross-linked polyethylene dual mobility systems demonstrate excellent early clinical, radiological, and survivorship results in a cohort of patients that demand high performance from their implants. It is envisaged that DM and second generation annealed HXLPE may reduce THA instability and wear, the two most common causes of THA revision in hip arthroplasty.

Comparative Results From a National Joint Registry Hip Data Set of a New Cross-Linked Annealed Polyethylene vs Both Conventional Polyethylene and Ceramic Bearings.

BACKGROUND: Major concerns in hip arthroplasty concern the fate of bearing surfaces. Highly cross-linked polyethylene materials (HXLPE) currently demonstrate successful in vitro results with new technical procedures of cross-linking the polyethylene material, whereas processing the polyethylene below its melting temperature to produce so-called "annealed HXLPE" would allow retention of important mechanical properties. METHODS: Data released by the National Joint Registry of England and Wales addressing in 45,877 hips the same Trident uncemented cup, allowed us to compare the performance of a consecutive cohort of patients implanted with the newest generation of annealed HXLPE acetabular bearings (X3: 21,470) vs 2 consecutive nonselected cohorts, one with conventional polyethylene (N2vac: 8225) and one with ceramic-on-ceramic (CoC) hip bearings (AL: 16,182). The main end point in survivorship has been first defined as revision for any cause, then for any cause which could be related to a failure of the bearing couple. RESULTS: At 6-year follow-up, all Trident cups demonstrated encouraging global survival cumulative rates all between 95% and 99%. A first study demonstrated better survivorship with X3-HXLPE liners vs conventional ultrahigh molecular weight polyethylene. On the second parallel study, the cumulative survival rates were better for X3 liners as compared to CoC bearings. Moreover, when ranking the yearly cumulative percent revision rates, again the best results were obtained with X3 liners with small alumina heads (cumulative percent revision rate at 0.298). CONCLUSION: Within the frame of this Trident study, the use of this X3 highly cross-linked annealed polyethylene could be considered as a reliable alternate solution to CoC bearings.

Clinical outcomes, survivorship and adverse events with mobile-bearings versus fixed-bearings in hip arthroplasty-a prospective comparative cohort study of 143 ADM versus 130 trident cups at 2 to 6-year follow-up.

The principle of dual mobility cups, often called "tripolar", has been developed to overcome the problem of instability following primary hip arthroplasty. We prospectively compared two cohorts which differed only by the type of bearings, i.e." mobile bearing hip" (MBH) in a 143-study cohort of ADM cups versus "fixed bearing hip" (FBH) of 130 Trident PSL cups, at a follow-up at 2-6years. The survival rates at 4.13-years, with instability as endpoint was significantly (P=0.0176) in favor of mobile bearings at 100% with no dislocation reported, versus 94.8% with fixed bearings. These mobile bearings, matching both "modern" dual mobility cups and annealed highly crossed polyethylene, would appear to offer at longer follow-up a valuable solution to clinical outcomes in acetabular arthroplasty.

Does high flexion after total knee replacement really improve our patients' quality of life at a short-term follow-up? : a comparative case-control study with hyperflex PFC Sigma versus a Triathlon knee series.

PURPOSE: A full range of motion after total knee arthroplasty has become more and more requested by our patients, leading to novel designs of knee implants, the so-called "hyperflex" knees. The aim of the present study was to confirm whether or not hyperflexion of operated knees really improves the patients' quality of life. METHODS: A retrospective comparative case-control study has been carried out to compare clinical results shown in two types of knee prosthesis, from two homogeneous paired groups of patients including 45 cases of a "hyperflex" model (RP-F), while the control group consisted of 43 cases of a "regular design" model (Triathlon) in terms of expected postoperative flexion. RESULTS: The hyperflex group demonstrated significant higher mean values of passive flexion at 119.9° in the RP-F group versus 111.1° in the Triathlon group. However, global results in the "regular" control group were significantly better than the "hyperflex" study group, in both IKS knee and functional scores at 84.4 points (RP-F) vs. 89.8 points (Triathlon), and 84.6 points (RP-F) vs. 89.5 points (Triathlon), respectively. Moreover, the self-administered KOOS questionnaire was significantly in favor of the control group, with 73.5 points in RP-F knees versus 86.0 points for Triathlon knees at global KOOS postoperative scores. CONCLUSION: The quality of life of operated patients after TKA obviously would be considered as the main priority, which was better obtained by a "regular design" in our study. Hence "high flexion" cannot be considered as an absolute target when choosing a model for total knee arthroplasty.

No differences found in bearing related hip survivorship at 10-12 years follow-up between patients with ceramic on highly cross-linked polyethylene bearings compared to patients with ceramic on ceramic bearings.

At a minimum follow-up of ten years we compared clinical and radiographic findings and survivorship in a cohort of 412 patients (447 hips) who received alumina on alumina CoC bearings to findings from a cohort of 216 patients (228 hips) with alumina on highly cross-linked polyethylene (HXLPE) bearings. All patients were operated for osteoarthritis. With bearing-related complications as endpoint, analysis showed no significant difference in survivorship between cohorts (99.8% for the CoC vs. 99.4% for HXLPE). In addition, there were no significant differences in clinical and radiographic findings between cohorts. We concluded that alumina on HXLPE bearings are a reasonable lower cost alternative to ceramic on ceramic bearing couples.

Are modern dual mobility cups a valuable option in reducing instability after primary hip arthroplasty, even in younger patients?

Hip instability after total hip replacement has been shown to be a critical cause of failure. The use of dual mobility has been classically restricted to patients "at risk", over 70 years of age. The question rises up about extended indications of so-called "modern" second generation dual mobility cups. This prospective multicenter study reports on first results at 2-5 years of the HA anatomical ADM cup upon two comparative groups of patients under 70 years (112 hips) vs. over 70 years of age (325 hips). No dislocation, migration, tilting, wear, or intra-prosthetic dislocation was recorded within each of the two cohorts. Survivorship for cup failures at this 4-year period was ideal at 100% in the younger patients, and 99.7% in the older group of patients.

Long lasting outcome of hydroxyapatite-coated implants in primary knee arthroplasty: a continuous series of two hundred and seventy total knee arthroplasties at fifteen to twenty two years of clinical follow-up.

PURPOSE: This study is a long-term review of an hydroxyapatite (HA)-coated knee prosthesis. Our aim was to confirm that excellent previously reported results with HA knees could stand the test of time at the 15-year milestone. METHODS: A total of 270 cruciate retaining HA-Omnifit knees, implanted in the same institution by a single surgeon with the same surgical procedure, were reviewed at 15-22 years of clinical follow-up (75 knees partially-coated and 195 fully-coated). RESULTS: At review, IKS mean values were 95.6 points for knee score and 91.19 points for function score. Radiological review confirmed an excellent long-lasting fixation over years in the long run. Taking implant failure as the end-point, the survival rate was 97.1% at 20 years. CONCLUSIONS: Our results were as good, and often better, than the best cemented or porous published studies. These very encouraging results at 15-22 years make us very confident in the ultimate outcome of bioconductive coatings in knee arthroplasty.

Outcomes of patellar resurfacing versus nonresurfacing in total knee arthroplasty: a 9-year experience based on a case series of scorpio PS knees.

Patellar resurfacing during total knee arthroplasty (TKA) is an actively debated issue. This prospective study addresses fundamental questions regarding whether to resurface the patella. To do this, we compared clinical results of Scorpio PS knees with and without patellar resurfacing to determine whether there was any statistically significant difference in survivorship, function, pain, and radiographic analyses. Our study failed to demonstrate any statistical difference between the 2 groups (resurfaced versus nonresurfaced) according to knee pain, walking abilities, stair climbing, range of motion, and radiologic findings, as well as cross-correlations between patellar pain and age, gender, obesity, or etiology. Our radiologic findings did not reveal any failures of bony structures facing the metallic flange. Some knee designs can thus be seen as "patella friendly." Given the significant cost of patella resurfacing and the resulting well-known complications, we continue to avoid systematic resurfacing of the patella during Scorpio TKA.

Is hydroxyapatite a reliable fixation option in unicompartmental knee arthroplasty? A 5- to 13-year experience with the hydroxyapatite-coated unix prosthesis.

Hydroxyapatite-coated unicompartmental knee arthroplasty (UKA) is a debatable approach to unicompartmental knee arthritis because UKA isoften viewed as a short-term solution, at best, fora condition that will eventually require a total knee arthroplasty (TKA). Unicompartmental knee arthroplasty is a more technically demanding procedure than TKA, and appropriate patient selection, careful surgical technique, and correct choice of implant geometry are all critical components to its success. A fundamental issue surrounding UKA is whether hydroxyapatite-coated unicompartmental components can provide a long-term solution to unicondylar arthritis. We address this issue in the current study, which is based on a prospective series of 125 hydroxyapatite-coated Unix knee prostheses implanted consecutively between 1994 and 2002, with a 5-year minimum follow-up and a 13-year maximum follow-up. The results of our study indicate that uncemented hydroxyapatite-coated UKA can be successful in the long term.

A 10-year minimum follow-up of hydroxyapatite-coated threaded cups: clinical, radiographic and survivorship analyses with comparison to the literature.

We evaluated the clinical, radiographic, and survivorship outcomes in a series of 418 threaded hydroxyapatite-coated acetabular cups (Arc2f; Osteonics, Allendale, NJ) implanted in a consecutive series of 384 patients undergoing primary total hip arthroplasty. In all cases, the cup was screwed into the prepared acetabulum. Bone screws were used to provide secondary fixation. At a minimum 10-year follow-up, 304 cups were available for analysis. The cumulative survivorship (mechanical failure as endpoint) at that time was 99.43% +/- 0.0104. Two hundred seventy-six hips were available for full clinical and radiographic review at or after the tenth anniversary. No unstable implants were noted; all implant fixation interfaces were classified as "stable bone ingrown," and the cup migration rate was zero. Based on the survivorship achieved with this implant, our results compare favorably with survivorship reported for the best cemented and cementless acetabular implant designs.