Kuntscher nail removal: Revision of a failed hip resurfacing above an incarcerated Kuntscher nail. A case report of a smart nail extraction technique through a custom-made instrumentation.

Removal of a retained and osseointegrated intramedullary femoral nail can represent a considerable problem, especially in the case of contemporary total hip arthroplasty or, even worse, in the case of revision hip arthroplasty. Usually, complex and invasive surgical techniques are required to remove incarcerated Kuntscher nails. We described a case of an incarcerated Kuntscher nail, inserted 39 years before, in a 75-year-old woman waiting for a revision total hip arthroplasty of a failed metal-on-metal hip resurfacing. A CT-based custom-made extra-long trephine reamer was designed and successfully used to easily extract the nail, leaving the proximal femur before a revision hip arthroplasty.

Short- to Mid-Term Clinical and Radiological Results of Selective Laser Melting Highly Porous Titanium Cup in Primary Total Hip Arthroplasty.

(1) Background: The aim of this study was to evaluate short- to mid-term clinical and radiological results in patients undergoing primary total hip arthroplasty (THA) with the use of a Selective Laser Melting 3D-printed highly porous titanium acetabular cup (Jump System Traser®, Permedica Orthopaedics). (2) Methods: We conducted a retrospective study and collected prospective data on 125 consecutive patients who underwent primary THA with the use of highly porous titanium cup. Each patient was evaluated preoperatively and postoperatively with a clinical and radiological assessment. (3) Results: The final cohort consisted of 104 patients evaluated after a correct value of 52 (38-74) months. The median Harris Hip Score (HHS) significantly improved from 63.7 (16-95.8) preoperatively to 94.8 (38.2-95.8) postoperatively (p < 0.001), with higher improvement associated with higher age at surgery (ß = 0.22, p = 0.025). On postoperative radiographs, the average acetabular cup inclination and anteversion were 46° (30°-57°) and 15° (1°-32°), respectively. All cups radiographically showed signs of osseointegration with no radiolucency observed, or component loosening. (4) Conclusions: The use of this highly porous acetabular cup in primary THA achieved excellent clinical, functional, and radiological results at mid-term follow-up. A better clinical recovery can be expected in older patients. The radiological evaluation showed excellent osseointegration of the cup with complete absence of periprosthetic radiolucent lines.

Hip arthrodesis conversion to dual mobility total hip arthroplasty in a young adult using a custom-made highly-porous titanium monobloc cup: A case report.

INTRODUCTION: Conversion of hip arthrodesis to total hip arthroplasty (THA) is an effective but challenging procedure to restore hip functionality and improve quality of life. Herein, a case of arthrodesis takedown to a dual mobility THA with a custom-made 3D-printed cup. PRESENTATION OF CASE: Due to higher risk of instability and loosening for the altered and atrophic anatomy, a custom-made highly-porous titanium dual mobility monobloc cup has been used for a cementless conversion THA in 31-year-old patient with hip arthrodesis. At 3-year follow-up clinical and radiographic results were excellent with the custom-made implant found stable and well osseointegrated. DISCUSSION: To the best of our knowledge, this is the first case of arthrodesis conversion to THA with custom-made highly-porous dual mobility cup in a young adult. The dual mobility construct helped reducing the risk of dislocation, while the highly-porous structure reduced the risk of aseptic loosening. CONCLUSION: The use of cementless highly-porous dual mobility implant in complex cases young patients is supported.

Evolution and New Generation of Dual Mobility Cups.

Although total hip arthroplasty (THA) is considered a successful procedure, hip dislocation remains the main cause of early failure. Dual mobility cups (DMCs) have been shown to significantly reduce the dislocation rate in both primary and revision THAs. During the past several decades, DMCs have evolved in design and fixation interface. There have been three generations of DMCs. This article addresses the rationale for a new cementless highly porous titanium DMC to improve component fixation and implant biocompatibility. [Orthopedics. 2023;46(5):e273-e280.].

The Effects of Different Femoral Component Materials on Bone and Implant Response in Total Knee Arthroplasty: A Finite Element Analysis.

Due to the high stiffness of the biomaterials used in total knee arthroplasty, stress shielding can lead to decreased periprosthetic bone mineral density and bone resorption. As different materials and 3D-printed highly porous surfaces are available for knee femoral components from the industry nowadays, this study aimed to compare the effects of two same-design cruciate-retaining femoral components, made with CoCr and titanium alloy, respectively, on periprosthetic bone stresses through a finite element model of the implanted knee in order to evaluate the induced stress shielding. Moreover, the effect of the cementless highly porous surface of the titanium implant was analyzed in comparison to the cemented interface of the CoCr implant. The von Mises stresses were analyzed in different periprosthetic regions of interest of the femur with different configurations and knee flexion angles. The titanium component induced higher bone stresses in comparison with the CoCr component, mostly in the medial compartment at higher knee flexion angles; therefore, the CoCr component led to more stress shielding. The model was revealed to be effective in describing the effects of different femoral component materials on bone stress, highlighting how a cementless, highly porous titanium femoral component might lead to less stress shielding in comparison to a cemented CoCr implant with significant clinical relevance and reduced bone resorption after total knee arthroplasty.

Is Modular Dual Mobility Superior to Standard Bearings for Reducing Dislocation Risk after Primary Total Hip Arthroplasty? A Retrospective Comparative Multicenter Study.

BACKGROUND: Dual mobility (DM) has been proven to reduce dislocation risk after total hip arthroplasty (THA). In the last decade modular DM (modDM) constructs have been introduced to allow the use of DM articulation with standard cementless acetabular shells. However, clinical evidence of modDM effectiveness is still low in primary THA and concerns about implant-related complications are increasing. This retrospective comparative multicenter study is aimed to investigate if the dislocation rate after primary THA could be reduced with modDM in comparison to standard bearing (SB). METHODS: 262 THAs were performed between 2017 and 2019, using SB (129 hips) or modDM (133) with the same cementless highly porous modular acetabular cup. Dislocations, complications and revisions were recorded and implant survival was analyzed. RESULTS: At 2.5-year mean follow-up, dislocation occurred in 4 hips (3.1%) within the SB group while intraprosthetic dislocation in 2 hips (1.5%) within the modDM group (p = 0.44). Implant survivals with revision due to dislocation were 95.2% and 95.9% at 4-year follow-up for SB and modDM, respectively (p = 0.50). CONCLUSIONS: modDM used in primary THA might reduce dislocation rate in comparison to SB, even in high-risk patients, however, caution is advocated due to specific intraprosthetic dislocation.

"Systematic review and meta-analysis of ceramic coated implants in total knee arthroplasty. Comparable mid-term results to uncoated implants."

BACKGROUND: Nitride-based ceramic coatings, such as titanium nitride (TiN) and titanium niobium nitride (TiNbN), have been introduced in total knee arthroplasty (TKA) to enhance the mechanical properties and biocompatibility of knee components, harden the metal surface and reduce CoCrMo exposure and metal ion release. However, the theoretical advantages of these ceramic coatings in TKA have yet to be fully elucidated. This systematic review aimed to provide clinical evidence on mid-term outcomes of ceramic-coated knee prostheses in comparison with uncoated standard CoCrMo knee prostheses in primary TKA. The hypothesis was that ceramic-coated implants can be used in primary TKA with no inferior outcomes compared to uncoated CoCrMo implants. METHODS: A systematic review of the literature was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to find all clinical studies regarding primary TKA with ceramic-coated knee prostheses. MEDLINE (PubMed), Embase and Cochrane Library were searched from 1990 to October 2020 to identify relevant studies for the first qualitative analysis. Using PICOS eligibility criteria, a subgroup of the selected studies was used to perform a meta-analysis. RESULTS: Fifteen studies were included in this systematic review, of which six were included in the meta-analysis: 3 randomized controlled trials, 2 retrospective comparative studies and 1 prospective cross-sectional study. Pooled data overall included 321 coated TKAs vs. 359 uncoated TKAs and a mean follow-up of 4.6 years (range, 2-10 years). No significant difference in the implant survival risk ratio with revision or reoperation due to any reason was found between coated and uncoated TKAs, even considering the RCT study subgroup with a risk ratio of 1.02 (P = 0.34). No significant differences were found for postoperative complications, clinical scores, or metal blood concentrations at 1 year. CONCLUSION: The findings of this systematic review and meta-analysis support the statement that ceramic-coated TKAs are not inferior to uncoated TKAs, showing comparable survival rates, complication rates and clinical outcomes. There is strong evidence that ceramic-coated TKA does not improve the clinical results or survival rate in comparison with uncoated TKA. LEVEL OF EVIDENCE: II,  Therapeutic.

Hip stability parameters with dual mobility, modular dual mobility and fixed bearing in total hip arthroplasty: an analytical evaluation.

BACKGROUND: Use of dual mobility (DM) in total hip arthroplasty has gained popularity due to the ability to reduce dislocation through increased jumping distance and impingement-free arc of movement. Recently, modular dual mobility (modDM) systems were introduced to give the possibility to use DM with standard metal-backed shells, however few has been studied to date regarding how jumping distance and the center of rotation change with modDM. The objective of this study was to evaluate, through analytical simulation, how jumping distance, center of rotation and arc of movement change between DM and standard cups with modDM or fixed bearings (FB). METHODS: 3D-models of DM and standard press-fit cups with modDM or FB liners were used to simulate DM, modDM and FB implant configurations, matched for same cup size, according to same cup position and different femoral head diameters. Jumping distance was calculated and center of rotation lateralization and oscillation angles were measured for each size of these three implant configurations. RESULTS: Jumping distance with modDM was reduced by -3.9 mm to -8.6 mm in comparison with DM, from 48 to 64 mm size, but resulted comparable to polyethylene 36 mm FB and increased by + 1.1 mm and + 1.4 mm than ceramic 36 and 40 mm FBs for sizes > 54 mm. ModDM lateralized the center of rotation up to + 2.5 mm and + 4.0 mm in comparison with DM and FBs, respectively. Oscillation angle with modDM resulted higher than + 16°, + 23°, + 17° and + 14° in comparison to DM, 28 mm, 32 mm and 36 mm FB cups, respectively, for 56 mm cup size. CONCLUSIONS: According to its specific design, modDM might change hip stability parameters in comparison to DM, worsening jumping distance and center of rotation position, but increasing arc of movement. As not restoring stability parameters in the same fashion, modDM implants should be properly used when DM cups are not feasible.

Use of a Plasma-Sprayed Titanium-Hydroxyapatite Femoral Stem in Hip Arthroplasty in Patients Older than 70 Years. Is Cementless Fixation a Reliable Option in the Elderly?

BACKGROUND: Although cementless implants are increasing in popularity, the use of cementless femoral stems for total hip arthroplasty (THA) and hip hemiarthroplasty (HH) in elderly patients remains controversial. The aim of this study was to report the outcomes of a cementless stem used in a large multicentric cohort of elderly patients receiving elective THA and HH for displaced femoral neck fracture. METHODS: A total of 293 patients (301 hips) aged 70 years or older (mean age, 78 years; range, 70-93) who received the same cementless plasma-sprayed porous titanium-hydroxyapatite stem were retrospectively evaluated after primary THA and HH to investigate stem survival, complications, and clinical and radiographic results. RESULTS: Cumulative stem survival was 98.5% (95% CI, 96.4-99.4%; 91 hips at risks) with revision due to any reason as the end-point at 10-year follow-up (mean 8.6 years, range 4-12). No stem was revised due to aseptic loosening. The mean Forgotten Joint Score was 98.7. Radiographically, the implants showed complete osseointegration, with slight stress-shieling signs in less than 10% of the hips. CONCLUSION: The use of cementless stems was proven to be a reliable and versatile option even in elderly patients for elective THA and HH for femoral neck fracture.

Wear performance of inverted non-conforming bearings in anatomic total shoulder arthroplasty.

BACKGROUND: Glenoid component failures still represent the most common complication in total shoulder arthroplasty. These failures depend on several factors, including ultra-high molecular weight polyethylene (UHMWPE) wear. One reason for UHMWPE wear in total shoulder arthroplasty may be the current use of a spherical prosthetic humeral head against a radially mismatched UHMWPE glenoid component, which leads to reduced glenohumeral translations, glenoid edge loading and high translational forces during shoulder motions. The aim of this study was to assess the in vitro wear of an anatomic total shoulder prosthesis with non-spherical non-conforming bearings with inverted conventional materials. METHODS: The wear of a vitamin E-blended UHMWPE non-spherical humeral head articulating against a non-conforming titanium-niobium nitride (TiNbN)-coated metallic glenoid was tested using a joint simulator. The wear test was performed by applying a constant load of 756 N with angular motions and translations. RESULTS: After 2.5 million cycles, the mean wear rate of the humeral head was 0.28 ± standard deviation (SD) 0.45 mg/million cycles. CONCLUSION: The low wear rate of the vitamin E UHMWPE humeral head supports the use of non-spherical non-conforming bearings with inverted conventional materials in anatomic total shoulder arthroplasty.

Restoring global offset and lower limb length with a 3 offset option double-tapered stem.

BACKGROUND: A proper restoration of hip biomechanics is fundamental to achieve satisfactory outcomes after total hip arthroplasty (THA). A global hip offset (GO) postoperatively reduction of more than 5 mm was known to impair hip functionality after THA. This study aimed to verify the restoration of the GO radiographic parameter after primary THA by the use of a cementless femoral stem available in three different offset options without length changing. METHODS: From a consecutive series of 201 patients (201 hips) underwent primary cementless THA in our center with a minimum 3-year follow up, 80 patients (80 hips) were available for complete radiographic evaluation for GO and limb length (LL) and clinical evaluation with Harris hip score (HHS). All patients received the same femoral stem with three different offset options (option A with - 5 mm offset, option B and option C with + 5 mm offset, constant for each sizes) without changing stem length. RESULTS: Mean GO significantly increased by + 3 mm (P < 0.05) and mean LL significantly decreased by + 5 mm (P < 0.05) after surgery, meaning that postoperatively the limb length of the operated side increased by + 5 mm. HHS significantly improved from 56.3 points preoperatively to 95.8 postoperatively (P < 0.001). Offset option A was used in 1 hip (1%), B in 59 hips (74%) and C in 20 hips (25%). CONCLUSIONS: The femur is lateralized with a mean of + 5 mm after surgery than, the native anatomy, whatever type of stem was used. Thus, the use of this 3-offset options femoral stem is effective in restoring the native biomechanical hip parameters as GO, even if 2 offset options were considered sufficient to restore GO.

Bilateral Total Hip Replacement in Dwarfism With a Custom Laser-Printed Trabecular Acetabular Shell.

Total hip arthroplasty in cases of dwarfism may be a demanding procedure, as the small-sized joints are difficult to replace with standard prostheses, even more so in the presence of dysplastic hips. The authors report a case of bilateral customized total hip arthroplasty performed in a young patient with proportionated dwarfism with bilateral hip dysplasia. To ensure sufficient stabilization of the cup, roof bone grafting was performed. The custom-made acetabular component was a trabecular acetabular shell manufactured using selective laser melting technology to ensure an optimal porous structure to enhance primary stability and bone ingrowth. Selective laser melting may be a promising alternative technology for manufacturing highly porous customized acetabular components for complex joint reconstruction procedures in which enhanced osseointegration ability is particularly required. [Orthopedics. 2019; 42(5):e477-e479.].

Vitamin E-stabilized UHMWPE: Biological response on human osteoblasts to wear debris.

UHMWPE doped with vitamin E was introduced to provide oxidation resistance upon sterilization, without affecting UHMWPE's mechanical properties. Particle-induced macrophage activation leads to periprosthetic bone resorption, requiring total joint replacements. During osteolysis, osteoblasts produce osteoimmunological factors such as RANKL and OPG, and the inhibitors of the Wnt pathway DKK-1 and Sclerostin. This study investigated in vitro how vitamin E-blended-UHMWPE wear debris might affect osteoblast-mediated osteolysis and the production of RANKL, OPG, Sclerostin and DKK-1, compared to conventional UHMWPE wear debris. Human osteoblastic SaOS2 cells were incubated with wear particles from Vitamin E doped and conventional UHMWPE and the gene expression and protein production of IL-6, RANKL, OPG, DKK-1, and Sclerostin was evaluated, RANKL, a bone erosion marker, was reduced, while OPG, a bone protective marker, were increased by the vitamin E-blended UHMWPE compared to conventional UHMWPE. Vitamin E doped UHMWPE reduced Sclerostin level, and partially affected DKK-1 production, thereby protecting against bone erosion. In conclusion, Vitamin E-blended UHMWPE induced an osteoimmunological response in bone cells that had positive effects on the osteolysis induced by wear debris, reducing aseptic loosening of the implants. In conclusion, this is the first study showing that Vitamin E-blended UHMWPE induced an osteoimmunological response in bone cells that positively affect the osteolysis induced by wear debris, thereby reducing the aseptic loosening of the implants.

Effectiveness of Vitamin-E-Doped Polyethylene in Joint Replacement: A Literature Review.

Since polyethylene is one of the most frequently used biomaterials, such as in bearing components in joint arthroplasty, strong efforts have been made to improve the design and material properties over the last decades. Antioxidants, such as vitamin-E, seem to be a promising alternative to further increase durability and reduce polyethylene wear and degradation in the long-term. Nevertheless, even if several promising in vitro results are available, there is yet no clinical evidence that vitamin-E polyethylenes show these advantages in vivo. The aim of this paper was to provide a comprehensive overview on the current knowledge regarding the biological and mechanical proprieties of this biomaterial, underlying the in vitro and in vivo evidence for effectiveness of vitamin-E-doped polyethylene in joint arthroplasty.

Radiographically undetectable periprosthetic osteolysis with ASR implants: the implication of blood metal ions.

Patients with ASR implants (resurfacing and large-diameter (XL) metal-on-metal (MoM) total hip arthroplasty), even if asymptomatic and with a stable prosthesis, may present extremely high blood metal ion levels. We report on a consecutive series of fourteen ASR revisions, focusing on osteolysis and their radiographic correspondence and their correlation with blood metal ion levels. At revision, seven hips revealed severe periacetabular osteolysis which was radiographically undetectable in six and asymptomatic in five. Seven hips with no acetabular osteolysis had significantly lower serum Cr and Co ion concentrations (respectively 25.2, 41.1 µg/l) compared to the seven hips with severe acetabular bone loss (respectively 70.1, 147.0 µg/l). Elevated blood metal ion levels should be considered as a warning of undetectable and ongoing periprosthetic osteolysis in asymptomatic patients with ASR prosthesis.

Cementless Metasul metal-on-metal total hip arthroplasties at 13 years.

Second-generation metal-on-metal bearings have been used since the late 1980s as alternative bearings to eliminate aseptic loosening due to polyethylene wear. The aim of the present study was to evaluate the long-term results of a series of Metasul (Zimmer GmbH, Winterthur, Switzerland) metal-on-metal total hip arthroplasty (THA). One hundred forty-nine cementless THAs with a 28-mm Metasul articulation were performed in 111 consecutive patients. The results were retrospectively reviewed at 13 years postoperatively. Clinical and radiographic evaluations and implant survivorship were performed. Seven hips (4.7%) were revised. The overall survivorship with revision for any reason as the end point was 0.94. The average Harris hip score was 91.4. Expansive osteolysis was found adjacent to the stem in 4 hips. Metal wear-related aseptic loosening was not the major reason for failure in our Metasul metal-on-metal THAs. Recurrent dislocation was the main reason for revision in our series.

Heterotopic ossifications after arthroscopic management of femoroacetabular impingement: the role of NSAID prophylaxis.

BACKGROUND: open hip surgery is known to be a risk for heterotopic ossification (HO), and nonsteroidal anti-inflammatory drugs (NSAIDs) have been widely recognized as an effective prevention. Hip arthroscopy is gaining popularity thanks to the possibility of treating femoroacetabular impingement (FAI) with a minimally invasive technique, however little is known about its rate of postoperative HO. The aim of the present study is to evaluate HO prevalence after hip arthroscopy for FAI and its relationship with NSAID prophylaxis. MATERIALS AND METHODS: we retrospectively reviewed 300 FAI cases who have been managed with hip arthroscopy in two different hospitals from April 2006 to May 2009. All medical records and indications at discharge were analyzed, focusing on administration of NSAIDs, as well as follow-up roentgenograms with regard to presence of HO around the hip joint. The patients were divided into two groups: a treatment group of 285 hips which received NSAID prophylaxis and a control group of 15 hips which did not. RESULTS: five hips presented HO, with overall prevalence of 1.6%. All five patients with HO belonged to the control group. No HO was observed in the treatment group. Thus, HO rate turned out to be significantly higher (P < 0.001) in patients who did not receive NSAIDs after surgery. CONCLUSION: arthroscopic treatment of FAI is not exempt from potential development of HO. NSAIDs after arthroscopic FAI treatment seem to be an effective prevention.

Intra-articular loose body removal during hip arthroscopy.

Loose bodies are common findings in hip arthroscopy. Loose body removal can be challenging because of the inner position of the acetabulum in which the loose bodies tend to accumulate. Moreover, the standard removal procedure of a considerable number of loose bodies may need a long time under limb traction, thereby increasing the risk of complications. This article describes a new easy method for intra-articular loose body removal. A flexible endotracheal catheter, connected with suction system, is inserted via the anterior or midanterior portal. The catheter can easily be directed toward the inner parts of the joint in proximity of loose bodies. The suction system allows the loose body to be captured in contact with the tip of the catheter, which is then retrieved carrying the loose body outside the cannula. We performed this technique on 4 consecutive patients with synovial chondromatosis. Patients were evaluated preoperatively and 1 month postoperatively by completing self-administered questionnaires. The technique effectiveness was evaluated in terms of overall surgery time, traction time, radiographic appearance of loose bodies left in situ, and postoperative complications. Mean overall surgery time and central time was 175 and 78 minutes, respectively. All patients showed improvement in the operated hip. All radiographs showed hip joint space free of osteochondral loose bodies. No patients reported paraesthesia, nerve palsy, or other postoperative complications. This technique allows for retrieval of a greater amount of loose bodies in a short time, reducing the possibility of undesirable complications.