For amputated patients, direct attachment of upper leg prosthesis to the skeletal system by a percutaneous implant is an alternative solution to the traditional socket fixation. Currently available implants, the OPRA system (Integrum AB, Göteborg, Sweden) and the ISP Endo/Exo prosthesis (ESKA Implants AG, Lübeck, Germany) [1-2] allow overcoming common soft tissue problems of conventional socket fixation and provide better control of the prosthetic limb [3], higher mobility and comfort [2, 4]. However, restraining issues such as soft-tissue infections, peri-prosthetic bone fractures [3, 5–8] and considerable bone loss around the stem [9], which might lead to implant's loosening, are present. Finally, a long a residual limb is required for implant fitting. In order to overcome the limiting biomechanical issues of the current designs, a new concept of the direct intramedullary fixation was developed. The aim was to restore the natural load transfer in the femur and allow implantations in short femur remnants (Figure 1). We hypothesize that the new design will reduce the peri-prosthetic bone failure risk and adverse bone remodeling. Generic CT-based finite element models of an intact femoral bone and amputated bones implanted with 3 analyzed implants were created for the study. Models were loaded with two loading cases from a normal walking obtained from the experimental measurements with the OPRA device [10-11]. Periprosthetic bone failure risk was evaluated by considering the von Mises stress criterion [12-14]. Subsequently the strain adaptive bone remodeling theory was used to predict long-term changes in bone mineral density (BMD) around the implants. The bone mineral content (BMC) change was measured around implants and the results were visualized in the form of DXA scans. The OPRA and the ISP implants induced the high stress concentration in the proximal region decreasing in the distal direction to values below physiological levels as compared with the intact bone. The stresses around the new design were more uniformly distributed along the cortex and resembled better the intact case. Consequently, the bone failure risk was reduced as compared to the OPRA and the ISP implants. The adaptive bone remodeling simulations showed high bone resorption around distal parts of the OPRA and the ISP implants in the distal end of the femur (on average −75% ISP to −78% OPRA after 60 months). The bone remodeling simulation did not reveal any bone loss around the new design, but more bone densification was seen (Figure 2). In terms of total bone mineral content (BMC) the OPRA and the ISP implants induced only a short-term bone densification in contrast to the new design, which provoked a steady increase in the BMC over the whole analyzed period (Figure 3). In conclusion, we have seen that the new design offers much better bone maintenance and lower failure probability than the current osseointegrated trans-femoral prostheses. This positive outcome should encourage further developments of the presented concept, which in our opinion has a potential to considerably improve safety of the rehabilitation with the direct fixation implants and allow treatment of patients with short stumps

Shoulder arthroplasty is effective at restoring function and relieving pain in patients suffering from glenohumeral arthritis; however, cortex thinning has been significantly associated with larger press-fit stems (fill ratio = 0.57 vs 0.48; P = 0.013)1. Additionally, excessively stiff implant-bone constructs are considered undesirable, as high initial stiffness of rigid fracture fixation implants has been related to premature loosening and an ultimate failure of the implant-bone interface2. Consequently, one objective which has driven the evolution of humeral stem design has been the reduction of stress-shielding induced bone resorption; this in-part has led to the introduction of short stems, which rely on metaphyseal fixation. However, the selection of short stem diametral (i.e., thickness) sizing remains subjective, and its impact on the resulting stem-bone construct stiffness has yet to be quantified. Eight paired cadaveric humeri (age = 75±15 years) were reconstructed with surgeon selected ‘standard’ sized and 2mm ‘oversized’ short-stemmed implants. Standard stem sizing was based on a haptic assessment of stem and broach stability per typical surgical practice. Anteroposterior radiographs were taken, and the metaphyseal and diaphyseal fill ratios were quantified. Each humerus was then potted in polymethyl methacrylate bone cement and subjected to 2000 cycles of compressive loading representing 90º forward flexion to simulate postoperative seating. Following this, a custom 3D printed metal implant adapter was affixed to the stem, which allowed for compressive loading in-line with the stem axis (Fig.1). Each stem was then forced to subside by 5mm at a rate of 1mm/min, from which the compressive stiffness of the stem-bone construct was assessed. The bone-implant construct stiffness was quantified as the slope of the linear portion of the resulting force-displacement curves. The metaphyseal and diaphyseal fill ratios were 0.50±0.10 and 0.45±0.07 for the standard sized stems and 0.50±0.06 and 0.52±0.06 for the oversized stems, respectively. Neither was found to correlate significantly with the stem-bone construct stiffness measure (metaphysis: P = 0.259, diaphysis: P = 0.529); however, the diaphyseal fill ratio was significantly different between standard and oversized stems (P < 0.001, Power = 1.0). Increasing the stem size by 2mm had a significant impact on the stiffness of the stem-bone construct (P = 0.003, Power = 0.971; Fig.2). Stem oversizing yielded a construct stiffness of −741±243N/mm; more than double that of the standard stems, which was −334±120N/mm. The fill ratios reported in the present investigation match well with those of a finite element assessment of oversizing short humeral stems3. This work complements that investigation's conclusion, that small reductions in diaphyseal fill ratio may reduce the likelihood of stress shielding, by also demonstrating that oversizing stems by 2mm dramatically increases the stiffness of the resulting implant-bone construct, as stiffer implants have been associated with decreased bone stimulus4 and premature loosening2. The present findings suggest that even a small, 2mm, variation in the thickness of short stem humeral components can have a marked influence on the resulting stiffness of the implant-bone construct. This highlights the need for more objective intraoperative methods for selecting stem size to provide guidelines for appropriate diametral sizing. For any figures or tables, please contact the authors directly

The management of periprosthetic distal femur fractures is an issue of increasing importance for orthopaedic surgeons. Because of the expanding indications for total knee arthroplasty (TKA) and an aging population with increasingly active lifestyles there has been a corresponding increase in the prevalence of these injuries. The management of these fractures is often complex because of issues with obtaining fixation around implants and dealing with osteopenic bone or compromised bone stock. In addition, these injuries frequently occur in frail, elderly patients, and the early restoration of function and ambulation is critical in these patients. There remains substantial controversy with respect to the optimal treatment of periprosthetic distal femur fractures, with some advocating for Locked Plating (LP), others Retrograde Intramedullary Nailing (RIMN) and finally those who advocate for Distal Femoral Replacement (DFR). The literature comparing these treatments, has been infrequent, and commonly restricted to single-center studies. The purpose of this study was to retrospectively evaluate a large series of operatively treated periprosthetic distal femur fractures from multiple centers and compare treatment strategies. Patients who were treated operatively for a periprosthetic distal femur fracture at 8 centers across North America between 2003 and 2018 were retrospectively identified. Baseline characteristics, surgical details and post-operative clinical outcomes were collected from patients meeting inclusion criteria. Inclusion criteria were patients aged 18 and older, any displaced operatively treated periprosthetic femur fracture and documented 1 year follow-up. Patients with other major lower extremity trauma or ipsilateral total hip replacement were excluded. Patients were divided into 3 groups depending on the type of fixation received: Locked Plating, Retrograde Intramedullary Nailing and Distal Femoral Replacement. Documented clinical follow-up was reviewed at 2 weeks, 3 months, 6 months and 1 year following surgery. Outcome and covariate measures were assessed using basic descriptive statistics. Categorical variables, including the rate of re-operation, were compared across the three treatment groups using Fisher Exact Test. In total, 121 patients (male: 21% / female: 79%) from 8 centers were included in our analysis. Sixty-seven patients were treated with Locked Plating, 15 with Retrograde Intramedullary Nailing, and 39 were treated with Distal Femoral Replacement. At 1 year, 64% of LP patients showed radiographic union compared to 77% in the RIMN group (p=0.747). Between the 3 groups, we did not find any significant differences in ambulation, return to work and complication rates at 6 months and 1 year (Table 1). Reoperation rates at 1 year were 27% in the LP group (17 reoperations), 16% in the DFR group (6 reoperations) and 0% in the RIMN group. These differences were not statistically significant (p=0.058). We evaluated a large multicenter series of operatively treated periprosthetic distal femur fractures in this study. We did not find any statistically significant differences at 1 year between treatment groups in this study. There was a trend towards a lower rate of reoperation in the Retrograde Intramedullary Nailing group that should be evaluated further with prospective studies. For any figures or tables, please contact the authors directly

Introduction. Transtibial osseointegration (TFOI) for amputees has limited but clear literature identifying superior quality of life and mobility versus a socketed prosthesis. Some amputees have knee arthritis that would be relieved by a total knee replacement (TKR). No other group has reported performing a TKR in association with TTOI (TKR+TTOI). We report the outcomes of nine patients who had TKR+TTOI, followed for an average 6.5 years. Materials & Methods. Our osseointegration registry was retrospectively reviewed to identify all patients who had TTOI and who also had TKR, performed at least two years prior. Four patients had TKR first the TTOI, four patients had simultaneous TKR+TTOI, and one patient had 1 OI first then TKR. All constructs were in continuity from hinged TKR to the prosthetic limb. Outcomes were: complications prompting surgical intervention, and changes in daily prosthesis wear hours, Questionnaire for Persons with a Transfemoral Amputation (QTFA), and Short Form 36 (SF36). All patients had clinical follow-up, but two patients did not have complete survey and mobility tests at both time periods. Results. Six (67%) were male, average age 51.2±14.7 years. All primary amputations were performed to manage traumatic injury or its sequelae. No patients died. Five patients (56%) developed infection leading to eventual transfemoral amputation 36.0±15.3 months later, and 1 patient had a single debridement six years after TTOI with no additional surgery in the subsequent two years. All patients who had transfemoral amputation elected for and received transfemoral osseointegration, and no infections occurred, although one patient sustained a periprosthetic fracture which was managed with internal fixation and implant retention and walks independently. The proportion of patients who wore their prosthesis at least 8 hours daily was 5/9=56%, versus 7/9=78% (p=.620). Even after proximal level amputation, the QTFA scores improved versus prior to TKR+TTOI, although not significantly: Global (45.2±20.3 vs 66.7±27.6, p=.179), Problem (39.8±19.8 vs 21.5±16.8, p=.205), Mobility (54.8±28.1 vs 67.7±25.0, p=.356). SF36 changes were also non-significant: Mental (58.6±7.0 vs 46.1±11.0, p=.068), Physical (34.3±6.1 vs 35.2±13.7, p=.904). Conclusions. TKR+TTOI presents a high risk for eventual infection prompting subsequent transfemoral amputation. Although none of these patients died, in general, TKR infection can lead to patient mortality. Given the exceptional benefit to preserving the knee joint to preserve amputee mobility and quality of life, it would be devastating to flatly force transtibial amputees with severe degenerative knee joint pain and unable to use a socket prosthesis to choose between TTOI but a painful knee, or preemptive transfemoral amputation for transfemoral osseointegration. Therefore, TTOI for patients who also request TKR must be considered cautiously. Given that this frequency of infection does not occur in patients who have total hip replacement in association with transfemoral osseointegration, the underlying issue may not be that linked joint replacement with osseointegrated limb replacement is incompatible, but may require further consideration of biological barriers to ascending infection and/or significant changes to implant design, surgical technique, or other yet-uncertain factors

Aim. Since surgical site infections (SSIs) remain among the most common complications of orthopedic (trauma) surgery, there has been unwavering attention for potential predictors of a SSI. Specifically in surgical fields with a high complication rate, such as foot/ankle surgery, risk factor identification is of great importance. Recently, some studies have suggested environmental factors such as season to be of influence on the number of SSI. Specifically patients operated on in the summer are reported to have a higher incidence of SSIs, compared to other seasons. The aim of this study is to identify if “seasonality” is a significant predictor for SSI in a cohort of (trauma) surgical foot and ankle procedures. Method. This retrospective cohort study included all patients undergoing trauma related surgery (fracture fixation, arthrodesis, implant removal and tendon repair) of the lower leg, ankle and foot. Procedures were performed at a single Level 1 Trauma Center in the Netherlands between September 2015 until February 2019. Potential risk factors/ confounders for SSI were identified using univariate analysis (Chi-Square/Mann-Whitney U). Procedures were divided in two groups: 1) performed in summer (June, July or August), 2) not performed in summer (September-May). The number of SSIs was compared between the 2 groups, correcting for confounders, using multivariate regression. Results. A total of 605 procedures were included, largely fracture fixation (371, 61.2%). Patients were on average 46 y/o and the majority was male (369, 60.9%). The total number of SSIs was 34 (5.6%). Age, American Society of Anesthesiologists (ASA) classification (1–2 or 3–4) and open fractures were identified as possible predicting factors of SSI. No difference in SSIs was found between summer and other seasons, neither in univariate analysis (4 (3.2%) vs 30 (6.3%), p=0.271), nor when corrected for confounders. Moreover, in multivariate analysis only an ASA of >2 and an open fracture remained as independent predictors of SSI. Conclusions. No seasonality could be identified in the rate of SSI after trauma surgery of the lower leg, ankle and foot in this cohort. A possible explanation for this lack of effect could be the temperate oceanic climate of the Netherlands. Larger temperature and precipitation differences may also influence the incidence of SSIs. However, previous studies suggesting seasonality in SSIs might also be purely based on coincidence, especially when uncorrected for confounders

Purpose. To promote rapid bone healing, an adequate stable fixation implant with a percutaneous reduction instrument should be used for Vancouver type B1 or C fractures. The objective of this study was to describe radiographic and clinical outcomes of patients with periprosthetic fracture (PPF) around a stable femoral stem, treated with a distal femoral locking plate alone or with a cerclage cable. Materials and Methods. A total of 21 patients with PPF amenable to either a reverse distal femoral locking plate (LCP DF. ®. ) alone or with a cerclage cable, with a mean age of 75.7 years, were included. In these patients, 10 fractures were treated with a reverse LCP DF. ®. alone and were classified as group I, and 11 additionally received a cerclage cable and were classified as group II.[Fig.1]. Results. Group I was not inferior to group II, as reflected by HHS evaluations. Additionally, group II had a significantly longer operation time (P = 0.019) than group I and included one patient with nonunion at the final 24-month follow-up visit after the initial fracture reduction.[Fig. 2]. Conclusion. Use of reverse LCP DF. ®. alone appears to provide advantages in the biological healing process compared with the use of reverse LCP DF. ®. with a cerclage cable. When comparing the stability of the fractures in both groups, there was no statistically significant difference, which might be attributed to the stable fixed-angle implant. For figures/tables, please contact authors directly.

Introduction. Aseptic loosening is the main reason for total knee arthroplasty (TKA) failure, responsible for more than 25% of the revision procedures, with most of the problems occurring with the tibial component. While early loosening can be attributed to failure of primary fixation, late implant loosening is associated with loss of fixation secondary to bone resorption due to altered physiological load transfer to the tibial bone. Several attempts have been made to investigate these changes in bone load transfer in biomechanical simulations and bone remodeling analyses, which can be useful to provide information on the effect of patient, surgery, or design-related factors. On the other hand, these factors have also been investigated in clinical studies of radiographic changes of bone density following TKA. In this study we made an overview of the knowledge obtained from these clinical studies, which can be used to inform clinical decision making and implant design choices. Methods. A literature search was performed to identify clinical follow-up studies that monitored peri-prosthetic bone changes following TKA. Within these studies, effects of the following parameters on bone density changes were investigated: post-operative time, region of interest, alignment, body weight, systemic osteoporosis, implant design and cementation. Moreover, we investigated the effect of bone density loss on implant survival. Results. A total of 19 studies was included in this overview, with a number of included patients ranging from 12 to 7,760. Most studies used DEXA (n=16), while a few studies performed analyses on calibrated digital radiographs (n=2), or computed tomography (n=1). Postoperative follow-up varied from 9 months to 10 years. Studies consistently report the largest bone density reduction within the first postoperative year. Bone loss is mainly seen in the medial region. This has been attributed to the change in alignment following surgery, during which often the pre-operative varus knee is corrected to a more physiological alignment, resulting in a load shift towards the lateral compartment. Measurements in unoperated contralateral legs were performed in 3 cases, and two studies performed standardized DEXA measurements to provide information on systemic osteoporosis. While on the short term no changes were observed, significant negative correlations have been found between severity of osteoporosis and peri-prosthetic bone density. No clear effects of bodyweight and cementation on bone loss have been identified. Although some studies do find differences between implant types, the variation in the data makes it difficult to draw general conclusions from these findings. Several studies reported no effect of bone loss on implant migration. In another study, a medial collapse was associated with a medial increase in density, suggesting that altered loading and increased stresses are responsible for both bone formation and the overload leading to collapse. Discussion. There are important lessons to be learned from these clinical studies, although generally the large spread in the DEXA data restricts strong conclusions. There is a large variation in used ROI definitions, complicating direct comparisons. Finally, most studies report density changes of well-functioning reconstructions, since only very large studies are able to gather enough failed cases

Recent introduction of short femoral implants has produced inconsistent outcomes. There have been reports of early aseptic failure as high as 30% within 2 years of implantation. This is in spite of the fact that these short components are shortened versions of existing successful non-cemented designs. The mode of initial fixation in non-cemented implants has been investigated. It has been demonstrated that long term survivability is dependent upon osseous integration; and that osseous integration requires secure initial implant fixation. Traditional non-cemented implants achieve initial fixation analogous to that of a nail in a piece of wood: friction and displacement (with resultant hoop stress). Initial fixation, of a traditional non-cemented femoral component, is directly proportional to surface area contact between the implant and endosteal bone and/or three point fixation. By reducing stem length, contact area may be significantly reduced, thereby increasing stresses over a smaller area of contact. The result of this is to potentially compromise fixation/implant stability against micromotion occurring in the early post-operative period. These stresses are most poorly resisted in flexion/extension and rotational planes about the long axis of the femur. In addition, force applied in an attempt to achieve initial fixation with a short stem may lead to an increased risk of periprosthetic fracture at the time of implantation. We propose that there is an alternative mode of initial fixation, a “rest fit”, that may avoid both the risk of femoral fracture as well as provide better initial implant stability. To assure a maximal initial fixation and resistance to post-operative stresses which may compromise initial implant stability and osseous integration, a short implant should have three distinct geometric features: a medial and lateral flare, a flat posterior surface and a proximal trapezoidal cross section. The first will provide stability against subsidence and varus migration, by resting upon the proximal femur. A flat posterior surface will maximize load transmission to the femur in flexon/extension activities; and an asymmetrical proximal cross-section will provide resistance against rotational stresses about the long axis of the femur during activities such as stairclimbing. Together these features have been throproughly evaluated by FEA and in vitro testing. We are reporting on the shoprt term follow up (2.5 years avg.) first 300 short stems which have employed a “rest fit”. There have been no aseptic failures or revisions for mechanical failure of these implants

The interest in osteolysis has waned largely due to the impact of crosslinked polyethylene and the “rarity” of this phenomenon. However, the basic process still remains: particles, motion observed with unstable implants and host specific factors all play a role in bone loss around implants. There are 2 predominant patterns of lysis: Linear versus Expansile. Linear Lysis: is focal bone loss at the interface as seen in the bone cement interface in when using acrylic or at the implant-host interface with porous ingrowth/ongrowth implants. Expansile Lysis: is observed in less contained regions such as the retro- and supra-acetabular regions around the socket. These lesions can also be quite extensive yet may be subtle in appearance. Imaging is essential in identifying the extent and magnitude of osteolysis. Available modalities include plain radiographs although they can be of limited value in that even with oblique views, they often underestimate the degree of bone loss. CT scans are useful but can be limited by artifact. Several centers have explored the role of MRI in assessing lysis. It can be useful for bone loss and provides excellent assessment for soft tissue: abductors, neurovascular structures. Metal artifact reduction sequencing is required to maximise information obtainable. Management of osteolysis: Identification and monitoring periprosthetic osteolysis is a crucial element of patient care. Progressive bone loss leading to loss of fixation and the potential risk for periprosthetic fracture is a real possibility and early recognition and intervention is a priority. The basic Guiding Principles of management are centered around several key elements including the source of osteolysis and degree, the fixation of implant, the location of lysis, the track record of implant system, the presence of patient symptoms (if any), and finally the patient age, activity level, and general health. Specifics of treatment of osteolysis around the acetabulum: With cemented sockets, lysis is typically seen late and frequently at the bone-cement interface. It is often associated with a loose implant and the prime indication for surgery may be pain. Treatment involves implant removal and revision with an uncemented cup and bone grafting or augmentation as needed. With uncemented sockets in the setting of osteolysis, there are several factors to consider. These have been stratified by Rubash, Maloney, and Paprosky. The treatment of these sockets has been summarised as follows: for Type I and Type II with limited lysis, lesional treatment such as debridement and bone grafting with head and polyethylene exchange has been suggested. WATCH for impingement!!!! Graft defects via trap-doors can be performed but make the door big enough to graft. Small doors and grafting through screw holes is at best marginal. In instances of compromised locking mechanisms, consider cementing the liner into the shell. For Type II and Type III implants, revision of the component is recommended. With the currently available cementless cup extraction tools, I rarely hesitate to remove a cup with moderate lysis and a broken locking mechanism: better access to lytic areas, better grafting achieved. CAVEAT #1: the disadvantage of implant removal is that it is clearly a bigger procedure and fixation of the new implant may be more difficult. Risks vs. rewards. CAVEAT #2: Socket revision in the setting of failed MOM implants has some unique “issues”. In the Vancouver series, almost 25% of the revision cups failed to achieve biologic fixation. As such, recommendation for using “enhanced” porous implants during revision seems prudent. Additionally, despite the use of larger diameter heads, instability rates remain high

Successful ORIF of proximal humeral fractures requires a careful assessment of the patient factors (age/osteoporosis/functional expectations), accurate identification the fracture segments (head/shaft/tuberosities) and accessory factors which are of vascular and surgical relevance (length of posteromedial metaphyseal head extension, integrity of medial soft tissue hinge, head split segments, tuberosity/head segments impacted to-gether or distracted apart). Fixation of the fracture can be achieved by a number of techniques because of the multiple factors that often apply—numerous techniques are usually required of the surgeon. The principles of fixation require accurate restoration of the head and tuberosity orientation, fixation of the metaphyseal segments (tuberosities) results in a stable circular platform on which the head segment rests. Thus, the fixation of choice acts as a load sharing device not a load bearing device. This fixation is often augmented with tension band and circlage suture fixation. These concepts are especially applicable to the osteoporotic patient. The order of fixation requires that the medial hinge not be disrupted. If it is disrupted in the younger patient it requires fixation first. All tuberosity segments are tagged with ethibond sutures. The head and the largest tuberosity segment are reduced and held with k-wire or canulated scews, avoiding the central medullary canal entry point. If the head tuberosity segment is unstable in relation to the shaft, the fixation implant of choice (plate/intramedullary) is chosen and the head/tuberosity complex is reduced to the shaft. Depending on the fracture segments and the degree of comminution this may require compression of distraction. Post-op the patient is immobilised in external rotation to balance the cuff forces. If very rigid fixation is achieved then early mobilisation is undertaken to minimise the adhesions due to opening of the subdeltoid space. If fixation is tenuous movement is commenced a 3–4 weeks. AVN of the humeral head with good tuberosity head architecure can be salvaged. The diagnosis of AVN is determned at three months with a MRI and consideration given to Zolidronate therapy. Post-traumatic stiffness with good architecture can be salvaged with an arthroscopic capsular release

Introduction: The goal is to avoid letting femoral deformity force suboptimal implant position/fixation. Suboptimal implant position has an adverse effect on hip biomechanics and often on hip function and durability. Classification: Practical approach to femoral deformities: categorise into 3 main groups: Very proximal, Subtrochanteric, Distal. Management: Management of distal deformities: Most can be ignored if there is sufficient room to place conventional femoral implant. Management of proximal deformities: Option 1: Use implants that allow satisfactory positioning despite deformity…or… Option 2: Remove the deformity. Management of subtrochanteric level deformities: These are the most difficult. Problems: Too proximal to ignore, Too distal to bypass. Main treatment options: Resurfacing THA, Short stem THA, Corrective osteotomy with THA. Corrective osteotomy with THA: Perform osteotomy at level of deformity, In most cases a corrective osteotomy that creates a transverse osteotomy junction is simplest, Use an implant that provides reliable fixation in the femur (usually uncemented), Use implant that provides fixation of the proximal and distal fragments. Conclusions: Majority of proximal femoral deformities managed with one-stage procedure: Excise deformity and replace with metal, Implants that allow ignoring deformity, Corrective osteotomy

A ceramic is currently considered as the most ideal articulation in primary THA. The authors evaluated clinicoradiographic results and complications of cementless THA with 3rd generation of ceramic bearing. From April 2001 to January 2008, 310 primary THAs were performed in 300 patients using 3rd generation of ceramic bearing. In results, Harris hip score at last follow up was improved to an average of 95.4 points from 51.6 points preoperatively. In all cases, fixations around implants were stable and there was no osteolysis. Complications were dislocations, squeaking, ceramic femoral head and liner fracture. Our outcomes using cementless THA with 3rd generation of ceramic articulation were satisfactory, but more clinical study and investigation will be necessary to reduce complications

Critical review of the literature fails to make a convincing case for use of cement in TKA. Many studies demonstrate clinical, mechanical, and biological failure when cement is used for fixation. Work by Ryd et al. has shown that initial migration within the first few months diminished rapidly after the first 6 months with virtually no additional movement for years after. They also suggested that cemented components do not remain rigidly fixed to bone long-term, but loosen enough to move 0.2 to 1 mm at the bone-cement interface with provocative testing. Although bone-ingrowth tibial components migrate slightly more initially than cemented ones do, they stabilise and do not sink progressively. Screw fixation adds rigidity, but does not seem to improve results. Rigidity of initial fixation is the most important feature after alignment to ensure pain-free function after arthroplasty, and can be achieved with press-fit techniques in TKA. Several early reports of bone-ingrowth TKA had inferior results because the tibial component had no stem, peg, or screw fixation, leading to implant migration and loosening. An effective stem has been shown to greatly improve tibial component fixation. The cut upper surface of the prepared tibia has areas that are too weak to withstand the forces that are applied to the surface, and failure in compression is likely unless fixation is augmented. An effective stem also reduces the shear and tensile loads at the bone-prosthesis interface. The effectiveness of compression or compaction of the tibial cancellous bone with an appropriately sized tibial metaphyseal stem has been shown, and probably was a major factor in the long-term success of fixation in our series. Clinical results of TKA with osteointegration techniques for fixation of the femoral and tibial components in our series are comparable with the best series reported with cemented fixation. Many recent studies show significant advantages of osteointegration over cement fixation in TKA. Fixation of implants with PMMA pressed into cancellous bone eventually loosens, and fixation of a metal component to bone cement also is tenuous in most cases. Cement is disappearing rapidly from use in total hip, ankle, and shoulder arthroplasty, and soon will be replaced with osteointegration technique in the knee. Perhaps the most appealing aspect of bone-ingrowth TKA is bone preservation. The ease of revisability because of good bone was encouraging in the components that wore, loosened, or became infected in the current series of TKA. These knees are functioning as well as knees with primary TKA. Should these knees develop additional problems, progressive destruction of bone is unlikely to occur, even if repeated revision is necessary

The key to management of instability when performing total shoulder arthroplasty is to recognise the potential for instability, and avoid the pitfalls which may lead to it post-operatively. Instability can result from incompetent capsular or rotator cuff soft tissue envelopes. It may also result from muscular imbalances, as well as incompetent bony architecture (severe posterior wear causing extreme retroversion, or anterior glenoid loss from fracture) extreme retroversion or improper placement or fixation of implants. Keys to providing a stable environment include performing careful soft tissue releases and providing muscular balance about the reconstructed arthroplasty; placement of implants in proper version; appropriate tensioning (height) and sizing (avoiding undersizing or overstuffing) of implants; recognizing incompetent rotator cuff substance or function and providing more stable, constrained implants (reverse total shoulder arthroplasty), when necessary. Keys to recognizing potential instability, tips and pearls for intra-operative and post-operative surgical management will be provided

Adequate fixation of implant components is an important goal for all arthroplasty procedures. Aseptic loosening is one of the leading causes of revision surgery in total knee arthroplasty. Radiostereometric analysis (RSA) is an imaging technique to measure implant migration, with established migration thresholds for well-fixed, at risk, and unacceptably migrating components. The purpose of the present study was to examine the long-term fixation of a cemented titanium fixed bearing polished tibial baseplate. Patients enrolled in a previous two-year prospective trial were recalled at ten years. All patients received a cemented, posterior-stabilised total knee replacement of the same design implanted by one of three surgeons. Of the original 35 patients, 16 were available for long-term follow-up, with one patient lost to follow-up, nine patients deceased, and a further nine patients unwilling to return to the clinic. Each patient underwent RSA imaging in a supine position using a conventional RSA protocol. Migration of the tibial component in all planes as well as maximum total point motion (MTPM) was compared between all time points (baseline, six weeks, three months, six months, one year, two years) up to the ten year follow-up visits. Outcome scores including the Knee Society Score (KSS), WOMAC, SF-12, and UCLA Activity Score were recorded. At ten years, the mean migrations of the tibial component were less than 0.1 mm and 0.1 degree in all planes relative to the post-operative RSA exam. There was no significant difference in tibial component migration between time points. However, MTPM increased significantly over time (p = 0.002), from 0.23 ± 0.18 mm at six weeks to 0.42 ± 0.20 mm at ten years. At one year, 13 patients had an acceptable MTPM level, three patients had an ‘at risk’ level, and no patient had an ‘unacceptable’ level. No patients were revised at ten years. WOMAC and KSS were significantly improved (p < 0.0001) at the latest follow-up compared to pre-operatively, but there was no difference in SF-12. The median UCLA Activity Score at latest follow-up was six (range, two to eight). The tibial baseplate demonstrated solid fixation at ten years. No patients had an unacceptable MTPM level at one year and no patients were revised at ten years, supporting the use of RSA to predict long-term loosening risk. The low level of tibial baseplate migration found in the present study correlates to the low rate of revision for this implant as reported in individual studies and in joint replacement registries

The goal is to avoid letting femoral deformity force suboptimal implant position/fixation. Suboptimal implant position has an adverse effect on hip biomechanics and often on hip function and durability. Classification - Practical approach to femoral deformities: categorise into 3 main groups: 1.) Very proximal, 2.) Subtrochanteric, 3.) Distal. Management of distal deformities: Most can be ignored if there is sufficient room to place conventional femoral implant. Management of proximal deformities: Option 1: Use implants that allow satisfactory positioning despite deformity…or… Option 2: Remove the deformity. Management of subtrochanteric level deformities: These are the most difficult. Problems: 1.) Too proximal to ignore, 2.) Too distal to bypass. Main treatment options: 1.) Resurfacing THA, 2.) Short stem THA, 3.) Corrective osteotomy with THA. Corrective osteotomy with THA: 1.) Perform osteotomy at level of deformity, 2.) In most cases a corrective osteotomy that creates a transverse osteotomy junction is simplest, 3.) Use an implant that provides reliable fixation in the femur (usually uncemented), 4.) Use implant that provides fixation of the proximal and distal fragments. Majority of proximal femoral deformities managed with one-stage procedure: 1.) Excise deformity and replace with metal, 2.) Implants that allow ignoring deformity, 3.) Corrective osteotomy

Background. Cementless short stems have the advantages of easy insertion, reduced thigh pain and being suitable for minimally-invasive surgery, therefore cementless short stem implants have been becoming more widely used. The revelation microMAX stem is a cementless short stem with a lateral flare design that allows for proximal physiological load transmission and more stable initial fixation. Images acquired with T-smart tomosynthesis using a new image reconstruction algorithm offer reduced artifacts near metal objects and clearer visualization of peri-implant trabeculae. Therefore, these images are useful for confirming implant fixation status after total hip arthroplasty (THA). We believe that T-smart tomosynthesis is useful for estimating the condition of microMAX stem fixation and will hereby report on observation of the postoperative course of microMAX stem. Materials and Methods. Subjects comprised 19 patients (20 hips) who underwent THA using micro MAXstem between July 2012 and November 2014 (males: 7, females: 12, mean age: 67 years, ranging from 38 to 83 years). Four patients had femoral head necrosis and 15 patients had osteoarthritis of the hip. All patients continuously underwent anterior-posterior and lateral view X-ray examination and an anterior-posterior T-smart tomosynthesis scan after the operations. Results. No stem loosening was noted in any subjects. X-ray images taken over time indicated spot welds in 12 hips (60%), while T-smart tomosynthesis showed spot welds in 19 hips (95%). Furthermore, reactive radiodense lines (tensile area) were noted on X-ray images of eight hips (40%), whereas they were detected by T-smart tomosynthesis in 10 hips (50%). A prominent reactive line around the tip of the stem was noted on X-ray images in three hips (15%), and this was detected by T-smart tomosynthesis in four hips (20%). Discussion. Compared to X-ray examination, T-smart tomosynthesis made it possible to perform detailed confirmation of trabecular structure. In this series, spot welds were confirmed in the proximal load area according to the micro MAXstem design concept. Tomosynthesis images of trabeculae and trabecular structure can be confirmed in more detail than X-ray or computed tomography images. This information is beneficial for understanding the state of load transmission and implant fixation. Conclusions. The addition of tomosynthesis to micro MAXstem postoperative evaluation made it possible to accurately grasp the state of fixation between implant and bone

Revision of the total hip femoral component in the presence of significant bone loss requires a variety of implants as well as fixation devices and bone substitute materials. Rule 1: Fix the implant into the best remaining bone. A variety of stem shapes and sizes are needed to fill the bone cylinder. Stem modularity is helpful to fashion a good fit, but every taper junction is a liability as a potential source of metal debris and a weak spot in the stem. Rather, fully porous-coated titanium femoral components with a tapered stem design are safe, convenient, and reasonably inexpensive. Rule 2: Reconstruct the bone to accept a rigidly fixed intramedullary stem. Cables, strut allograft, plates, and screws are needed to support the remaining bone. Rule 3: Manage the bone so that it is still viable after the implant is inserted. As much intraosseous and extraosseous blood supply as possible should be maintained, so broaching rather than extensive reaming is the best choice for maintaining bone viability. Rarely more exotic procedures such as reduction osteotomy must be done to achieve rigid fixation of implants

During TKA, a surgeon has 4 options: not to use a tourniquet at all, use it from incision to closure, from incision until cementing, and only during cementing. The potential advantages of using a tourniquet are: to reduce blood loss, to have a clear operative field, to facilitate preparation of bony surfaces that are optimal for cementation and longevity of fixation of implants, and to reduce the potential for blood-borne disease transmission through needlestick injuries. Potential disadvantages of tourniquet use have been outlined by the previous speaker. In particular, using a tourniquet from incision until closure has several disadvantages and is generally not a preferred option. While this paper opposes tourniquetless TKA, it supports using a tourniquet from incision until cementing. We will present in support the findings of our prospective, randomised, double-blind study in patients undergoing cemented, navigated, bilateral simultaneous TKA wherein a tourniquet was used from incision until cementing was complete on one side and compared with the other knee in which a tourniquet was used only during cementing. We compared knee pain, thigh pain, blood loss, hemodynamic changes, functional outcome and complications. We concluded that total knee arthroplasty can be safely and effectively performed with the use of the tourniquet from skin incision until cementing without adverse effects

Objectives. How to position a unicompartmental knee replacement (UKR) remains a matter of debate. We suggest an original technique based on the intra-operative anatomic and dynamic analysis of the operated knee by a navigation system, with a patient-specific reconstruction by the UKR. The goal of the current study was to assess the feasibility of the new technique and its potential pitfalls. Methods. 100 patients were consecutively operated on by implantation of a UKR with help of a well validated, non-image based navigation system, by one single surgeon. There were 41 men and 59 women, with a mean age of 68 years (range, 51 to 82 years). After data registration, the navigation system provided the dynamic measurement of the coronal tibio-femoral mechanical angle in full extension. The reducibility of the deformation was assessed by a manually applied torque in the valgus direction. The patient-specific analysis was based on the following hypotheses: 1) The normal medial laxity in full extension is 2° (after previous studies), 2) there was no abnormal medial laxity (which may be routinely accepted for varus knees) and 3) the total reducibility is the sum of the patient's own medial laxity and of the bone and cartilage loss. We assumed that the optimal correction may be calculated by the angle of maximal reducibility, less 2° to respect the normal medial laxity. The bone resections were performed accordingly to this calculated goal. No ligamentous balance or retension was performed. The fine tuning of the remaining laxity was performed by adapting the height of polyethylene component with a 1 mm step. The final measurements (coronal tibio-femoral angle in full extension and medial laxity in full extension) were performed with the navigation system after the final components fixation. The implantation had to fulfill these two parameters: optimal correction as defined previously, and a 2 ± 1° of medial laxity. Results. Before UKR, the mean coronal tibio-femoral angle in full extension was 3.9°± 2.4° without stress, and 0.7°+2.3° with valgus stress. The mean medial laxity in full extension before UKR was 3.2°+1.3°. After UKR, the mean coronal tibio-femoral angle in full extension was 2.6°+2.9°. The mean medial laxity in full extension after UKR was 1.9°+0.8°. The complete goal was obtained for 74% of the case. The optimal correction of the coronal tibio-femoral angle in full extension alone was achieved for 78% of the cases. 94% of the cases had an optimal medial laxity in full extension. Conclusion. The patient-specific UKR reconstruction according to the criteria defined was possible and its accuracy was good. The accuracy of a navigation system and the modularity of the prosthesis components seem to be significant prerequisites. The adaptation of the UKR to the patient may be easier, and the ligamentous physiology may be better restored because of the absence of any soft-tissue release. The final functional result may be improved