Advances in the performance and longevity of total joint arthroplasty (TJA) have been enabled by related progress in implant materials, device designs, and surgical techniques. Successful TJA also depends upon adequate
In cases of poor
Purpose. Stress fractures (SFs) are highly prevalent in female athletes, especially runners (1337%), and result in pain and lost training time. There are numerous risk factors for SFs in athletes; however, the role of
Introduction. Initial large-scale clinical studies of porous tantalum implants have been generally promising with well-fixed implants and few cases of loosening [1–3]. An initial retrieval study suggests increased bone ingrowth in a modular tibial tray design compared to the monoblock design [4]. Since micromotion at the bone-implant interface is known to influence bone ingrowth [5], the goal of this study was to determine the effect of implant design,
The
Dorr bone type is both a qualitative and quantitative classification. Qualitatively on x-rays the cortical thickness determines the ABC type. The cortical thickness is best judged on a lateral x-ray and the focus is on the posterior cortex. In Type A bone it is a thick convex structure (posterior fin of bone) that can force the tip of the tapered implant anteriorly – which then displaces the femoral head posteriorly into relative retroversion. Fractures in DAA hips have had increased fractures in Type A bone because of the metaphyseal-diaphyseal mismatch (metaphysis is bigger than diaphysis in relation to stem size). Quantitatively, Type B bone has osteoclastic erosion of the posterior fin which proceeds from proximal to distal and is characterised by flattening of the fin, and erosive cysts in it from osteoclasts. A tapered stem works well in this bone type, and the bone cells respond positively. Type C bone has loss of the entire posterior fin (stove pipe bone), and the osteoblast function at a low level with dominance of osteoclasts. Type C is also progressive and is worse when both the lateral and AP views show a stove pipe shape. If just the lateral x-ray has thin cortices, and the AP has a tapered thickness of the cortex a non-cemented stem will work, but there is a higher risk for fracture because of weak bone. At surgery Type C bone has “mushy” cancellous bone compared to the hard structure of type A. Tapered stems have high risk for loosening because the diaphysis is bigger than the metaphysis (opposite of Type A). Fully coated rod type stems fix well, but have a high incidence of stress shielding. Cemented fixation is done by surgeons for Type C bone to avoid fracture, and insure a comfortable hip. The large size stem often required to fit Type C bone causes an adverse-stem-bone ratio which can cause chronic thigh pain. I cement patients over age 70 with Type C bone which is most common in women over that age.
Femoral knee implants have promising outcomes, although some high-flex designs have shown rather high loosening rates (Han et al., 2007). In uncemented implants, it is vital to limit micromotions at the implant-bone interface, to facilitate secondary fixation through bone ingrowth (kienapfel et al., 1999). Hence, it is essential to investigate how micromotions of different uncemented implants are affected by various loading conditions when a range of
Disorders of bone integrity carry a high global disease burden, frequently requiring intervention, but there is a paucity of methods capable of noninvasive real-time assessment. Here we show that miniaturized handheld near-infrared spectroscopy (NIRS) scans, operated via a smartphone, can assess structural human bone properties in under three seconds. A hand-held NIR spectrometer was used to scan bone samples from 20 patients and predict: bone volume fraction (BV/TV); and trabecular (Tb) and cortical (Ct) thickness (Th), porosity (Po), and spacing (Sp).Aims
Methods
Bone turnover and the accumulation of microdamage are impacted by the presence of skeletal metastases which can contribute to increased fracture risk. Treatments for metastatic disease may further impact
Bone turnover and the accumulation of microdamage are impacted by the presence of skeletal metastases which can contribute to increased fracture risk. Treatments for metastatic disease may further impact
Introduction. Loosening of the baseplate is one of the most common causes of failure in Reverse Shoulder Arthroplasty. To allow osteo-integration to occur and thus provide long-term stability, initial screws fixation plays a pivotal role. In particular, tightening torque and force of nonlocking screws are two parameters that are considered to have a clear impact on implant stability, yet the relation is not fully understood. For this reason, this study aims to define an experimental set-up, to measure force and torque in artificial bone samples of different quality, in order to estimate ranges of optimal surgical values and give guidelines to maximize screw fixation and therefore initial implant stability. Methods. A custom-made torque sensor (Figure 1a) was built and calibrated using a lever deadweight system. To measure the compression force generated by the screw head, three thin FlexiForce sensors (Tekscan, South Boston, US) were enclosed between two 3D printed plates with a central hole to allow screw insertion (Figure 1b). The tightening force, represented by the sum of the three sensors, was calibrated using a uniaxial testing machine (Zwick/Roell, Ulm, Germany). Multiple screw lengths (26mm, 32mm and 47mm) were selected in the protocol. Synthetic bone blocks (Sawbones; Malmö, Sweden) of 20 and 30 PCF were used to account for
OSSTEC is a pre-spin-out venture at Imperial College London seeking industry feedback on our orthopaedic implants which maintain
Abstract. Background. Atypical femur fracture (AFF) is a well known complication of Bisphosphonate therapy. Due to prolonged suppression of bone re-modelling in these fractures, surgical complications are difficult to manage. The aim of this study was to analyze the causes of surgical complications in AFF fixations and provide algorithm for management. Method. In this retrospective 10-year study (2010–2020), we identified patients surgically treated for AFF. We included patients who underwent revision surgery for any cause. Data collection included demographics, surgical complications, details of revision surgery and time to union. Result. Out of 57 patients who were operated for AFF, 17 underwent revision fixation. The average age was 69 with only 2 males. Around two-third (64%) were sub-trochanteric fractures and method of fixation in 64% cases was intra-medullary nail. The most common complication was non-union (12), followed by stress fracture and infection in 3 and 2 cases respectively. In most cases inadequate reduction and sub-optimal fixation was perceived as cause of failure except two cases which got infected. Revision fixation in all cases included improved bone contact (non-union site osteotomy), use of bone morphogenic proteins and improved fixation with augmentation device (either nail or plate). Follow up at 1 year showed fracture union in 12 cases, remaining 5 revision fixations failed, 3 of which were managed with proximal femur replacement. Conclusion. High rate of non-union after fixation in AFF. Optimizing the fixation construct results in union in most cases. However, arthroplasty should be considered in elderly patients with poor
The use of endoprosthesis implants is frequent for tumours involving the proximal third of the femur and not amenable to primary arthroplasty or internal fixation. In this population, these implants are preferentially cemented given poor
Patients undergoing revision surgery of a primary total hip arthroplasty often exhibit bone loss and poor
Introduction. Charcot Arthropathy related foot and ankle deformities are a serious challenge. Surgical treatment of these deformities is now well established. The traditional surgical method of extensive surgical exposure, excision of bone, acute correction and internal fixation is not always appropriate in presence of active ulceration, deep infection and poor
Introduction. Open fractures are fortunately rare but pose an even greater challenge due to poor soft tissues, in addition to poor
The most common classification of periprosthetic femoral fractures is the Vancouver classification. The classification has been validated by multiple centers. Fractures are distinguished by location, stability of the femoral component, and
The Failed Femoral Neck Fracture. For the young patient: Attempt to preserve patient's own femoral head. Clinical results reasonably good even if there are patches of avascular necrosis. Preferred methods of salvage: valgus-producing intertrochanteric femoral osteotomy: puts the nonunion under compression. Other treatment option: Meyer's vascularised pedicle graft. For the older patient: Most reliable treatment is prosthetic replacement. Decision to use hemiarthroplasty (such as bipolar) or THA based on quality of articular cartilage, perceived risk of instability problem. In most patients THA provides higher likelihood of excellent pain relief. Specific technical issues: (1) hardware removal: usually remove after hip has first been dislocated (to reduce risk of femur fracture); (2) Hip stability: consider methods to reduce dislocation risk: larger diameter heads/dual mobility/anteriorly-based approaches; (3) Acetabular
The primary objectives of this study were to: 1) identify risk factors for subsequent surgery following initial treatment of proximal humerus fractures, stratified by initial treatment type; 2) generate risk prediction tools to predict subsequent shoulder surgery following initial treatment; and 3) internally validate the discriminative ability of each tool. We identified patients ≥ 50 years with a diagnosis of proximal humerus fracture from 2004 to 2015 using linkable health datasets in Ontario, Canada. We used procedural and fee codes within 30 days of the index fracture to classify patients into treatment groups: 1) surgical fixation; 2) shoulder replacement; and 3) conservative. We used intervention and diagnosis codes to identify all instances of complication-related subsequent shoulder surgery following initial treatment within two years post fracture. We developed logistic regression models for randomly selected two thirds of each treatment group to evaluate the association of patient, fracture, surgical, and hospital variables on the odds of subsequent shoulder surgery following initial treatment. We used regression coefficients to compute points associated with each of the variables within each category, and calculated the risk associated with each point total using the regression equation. We used the final third of each cohort to evaluate the discriminative ability of the developed risk tools (via the continuous point total and a dichotomous point cut-off value for “higher” vs. “lower” risk determined by Receiver Operating Curves) using c-statistics. We identified 20,897 patients with proximal humerus fractures that fit our inclusion criteria for analysis, 2,414 treated with fixation, 1,065 treated with replacement, and 17,418 treated conservatively. The proportions of patients who underwent subsequent shoulder surgery within two years were 13.8%, 5.1%, and 1.3%, for fixation, replacement, and conservative groups, respectively. Predictors of reoperation following fixation included the use of a bone graft, and fixation with a nail or wire vs. a plate. The only significant predictor of reoperation following replacement was poor