Increasing femoral
Introduction and Objective. A proper restoration of hip biomechanics is fundamental to achieve satisfactory outcomes after total hip arthroplasty (THA). A global hip
Aims. Hip arthroplasty does not always restore normal anatomy. This is due to inaccurate surgery or lack of stem sizes. We evaluated the aptitude of four total hip arthroplasty systems to restore an anatomical and medialized hip rotation centre. Methods. Using 3D templating software in 49 CT scans of non-deformed femora, we virtually implanted: 1) small uncemented calcar-guided stems with two
Purpose. The ultimate goal in total hip arthroplasty is not only to relieve the pain but also to restore original hip joint biomechanics. The average femoral neck-shaft angle(FNSA) in Korean tend to have more varus pattern. Since most of conventional femoral stems have relatively high, single, fixed neck shaft angle, it's not easy to restore vertical and horizontal
Aims. Achieving accurate implant positioning and restoring native hip biomechanics are key surgeon-controlled technical objectives in total hip arthroplasty (THA). The primary objective of this study was to compare the reproducibility of the planned preoperative centre of hip rotation (COR) in patients undergoing robotic arm-assisted THA versus conventional THA. Methods. This prospective randomized controlled trial (RCT) included 60 patients with symptomatic hip osteoarthritis undergoing conventional THA (CO THA) versus robotic arm-assisted THA (RO THA). Patients in both arms underwent pre- and postoperative CT scans, and a patient-specific plan was created using the robotic software. The COR, combined
The purpose of this study was to describe the
radiological characteristics of a previously unreported finding: posterior
iliac
Abstract. Introduction. There is growing interest in the use of robotic Total Knee Arthroplasty (TKA) to improve accuracy of component positioning. This is the first study to investigate the radiological accuracy of implant component position using the ROSA® knee system with specific reference to Joint Line Height, Tibial Slope, Patella Height and Posterior Condylar
Introduction & aims. Correct prosthetic alignment is important to the longevity and function of a total hip replacement (THR). With the growth of 3-dimensional imaging for planning and assessment of THR, the importance of restoring, not just leg length and medial
Background. Total hip arthroplasty requires proper sizing and placing of implants to ensure excellent outcomes and reduce complications. Calculation of femoral
Aims. Traditionally, total hip arthroplasty (THA) templating has been performed on anteroposterior (AP) pelvis radiographs. Recently, additional AP hip radiographs have been recommended for accurate measurement of the femoral
Because the femoral head/neck junction is preserved in hip resurfacing, patients may be at greater risk of impingement, leading to abnormal wear patterns and pain. We assessed femoral head/neck
Introduction.
Introduction. Highly crosslinked, ultra-high molecular weight polyethylene (HXLPE) acetabular liners inherently have a risk of fatigue failure associated with femoral neck impingement. One of the potential reasons for liner failure was reported as crosslinking formulations of polyethylene, increasing the brittleness and structural rigidity. In addition, the acetabular component designs greatly affect the mechanical loading scenario, such as the
Hip resurfacing is being performed more frequently in the United Kingdom. The possible benefits include more accurate restoration of leg length, femoral
Several factors have been implicated in unsatisfactory
results after total hip replacement (THR). We examined whether femoral
offset, as measured on digitised post-operative radiographs, was
associated with pain after THR. The routine post-operative radiographs
of 362 patients (230 women and 132 men, mean age 70.0 years (35.2
to 90.5)) who received primary unilateral THRs of varying designs
were measured after calibration. The femoral
Instability following total hip arthroplasty (THA) is an unfortunately frequent and serious problem that requires thorough evaluation and preoperative planning before surgical intervention. Prevention through optimal index surgery is of great importance, as the management of an unstable THA is challenging even for an experienced joints surgeon. However, even after well-planned surgery, a significant incidence of recurrent instability still exists. Moreover leg-length discrepancy (LLD) after THA can pose a substantial problem for the orthopaedic surgeon. Such discrepancy has been associated with complications including nerve palsy, low back pain, and abnormal gait. Consequently we may use a big femoral head or increase femoral
Purpose of the study: The extramedullary anatomy of the femur must be reproduced during total hip arthroplasty in order to ensure correct tension on the gluteus muscles. This requires:. correct
Background. Posterior referencing (PR) total knee arthroplasty (TKA) aims to restore posterior condylar
Introduction. The inferior/medial shift in the center of rotation (CoR) associated with reverse shoulder arthroplasty (rTSA) shortens the anterior and posterior shoulder muscles; shortening of these muscles is one explanation for why rTSA often fails to restore active internal/external rotation. This study quantifies changes in muscle length from
In a prospective study between 2000 and 2005, 22 patients with primary osteoarthritis of the shoulder had a total shoulder arthroplasty with a standard five-pegged glenoid component, 12 with non-offset humeral head and ten with
Introduction:. Implant dislocations are often caused by implant or bone impingement, and less impingement is critical to prevent dislocations. Several reports demonstrated that greater femoral
Objectives. Preservation of posterior condylar
Aims: Femoral
Reverse total shoulder arthroplasty (RTSA) is an increasingly common treatment for osteoarthritic shoulders with irreparable rotator cuff tears. Although very successful in alleviating pain and restoring some function, there is little objective information relating geometric changes imposed by the reverse shoulder and arm function, particularly the moment generating capacity of the shoulder muscles. Recent modeling studies of reverse shoulders have shown significant variation in deltoid muscle moment arms over a typical range of humeral
Purpose of the study: Theoretically, in first-intention total hip arthroplasty (THA), restoration of femoral
Introduction:. Total hip arthroplasty (THA) is extremely effective in treating debilitating arthritic conditions of the hip. With the many modular prosthetic designs available, surgeons can now precisely construct mechanical parameters such as femoral
Introduction. One of the important criteria of the success of TKR is achievement of the Flexion ROM. Various factors responsible to achieve flexion are technique, Implant and patient related. Creation of the Posterior condylar
Proper restoration of posterior condylar
Background. Most of contemporary total knee systems address on improving of range of motion and bearing materials. Although new total knee designs in most systems accommodated the knee morphology according to gender differences, reestablishing of the same anterior
Introduction. Inappropriate soft tissue tension around an artificial hip is regarded as one cause of dislocation or abductor muscle weakness. It has been considered that restoration of leg
The aim of this retrospective cohort study was
to identify any difference in femoral
Introduction. Subluxation and dislocation are frequently cited reasons for THA revision. For patients who cannot accommodate a larger femoral head, an
Introduction. Accurate evaluation of femoral
During total hip arthroplasty various femoral stem
Background The magnitude of the medial
Introduction. The effect of the implant posterior condylar
Introduction. Reverse shoulder arthroplasty (rTSA) increases the deltoid abductor moment arm length to facilitate the restoration of arm elevation; however, rTSA is less effective at restoring external rotation. This analysis compares the muscle moment arms associated with two designs of rTSA humeral trays during two motions: abduction and internal/external rotation to evaluate the null hypothesis that
Introduction. Total hip replacement (THR) is a very common procedure performed for the treatment of osteoarthritis of the hip. The aim of THR is to restore function and quality of life of the patients, by restoring femoral
Introduction: During total hip arthroplasty various femoral stem
In recent years the majority of X-ray departments have moved to a digital format of recording and archiving radiographs. These digital images (as with previous ‘films’) have a built in magnification factor (variable with each patient), which, may cause errors in templating for joint replacement surgery. Placing a marker of known size at the same level as the joint in question allows calculation of the magnification. This may help to restore hip
After total hip replacement, force generating capacity of gluteal muscles is an impotant parameter on joint contact forces and primary fixation of total hip replacement. Femoral
Introduction: Restoration of hip biomechanics is an important part of successful total hip replacement. Preoperative templating acts as a guide to selection of size and positioning of prostheses to enable this. We aimed to Establish how closely natural femoral
Objectives. Posterior condylar
Surgeons are becoming increasingly aware of the importance of matching a patient’s native
We have studied the concept of posterior condylar
Hip simulator studies have shown reduced hip
Introduction:. One of the important criteria of the success of TKR is achievement of the Flexion ROM. Various factors responsible to achieve flexion are technique, Implant and patient related. Creation of the Posterior condylar
Background:. We studied the effect of posterior condylar
Introduction. Leg length and
Hip prostheses that do not reproduce the patients’ preoperative femoral
Incorrect restoration of leg length (LL) and
Purpose: Polyethylene wear in total hip arthroplasty remains the most limiting factor for implant survival. Several predictive factors are well identified, but the position of the articulating pieces remains to be studied in detail. We searched for a correlation between polyethylene wear and the position of the femoral and acetabular pieces, particularly the femoral
Development of more effective diagnostic and therapeutic solutions is vital to tackling the growing challenge of bone diseases and disorders in aging societies. Spatially
The reproduction of ideal
Functional evaluations using the Harris hip scoring system and the delayed Trendelenberg test were performed on fifty randomly selected patients who had undergone cemented primary CPT total hip replacements (Zimmer UK) at least 12 months previously using Hardinge approach. The prosthesis used increases
Introduction: Trochanteric bursitis (TB) in association with increased femoral
Aim: To present the experience of a highly specialized total knee arthroplasty revision center with the use of femoral and tibial components with modular press-fit
Introduction. Leg length and
Purpose: Femoral
Background. Traditional measurements of hindfoot alignment are based on the tibio-calcaneal angle and do not take the forefoot into account. We have developed an algorithm based on standard radiographs to calculate calcaneal
Aim: To present the experience of a highly specialized total knee arthroplasty revision center with the use of femoral and tibial components with modular press-fit
Purpose of the study: Hip resurfacing (HR) is becoming popular again with the advent the the metal-on-metal bearing. This type of surgery is proposed for young, often very active, patients for whom restoration of optimal hip joint range of motion constitutes and important objective. The purpose of this work was to analyse anterior translation of the femoral component to optimise joint range of motion (particularly flexion). Material and method: From September 2007 to May 2008, 68 hip resurfacing prostheses were implanted in 66 patients aged on average 45 years (range 19–61). All procedures were performed by the same operator using a posterorlateral approach and the same surgical technique. Anterior head-neck
Is there an optimal way to place a glenoid in reverse total shoulder arthroplasty (RTSA)? Four of the six parameters that a surgeon can control in a RTSA involve the glenoid. The parameters are: inferior tilt, increased lateral or inferior
Background: The determinants of range of movement following knee replacement may be surgically modifiable (tibial slope, posterior condylar
To maximise the long-term survivorship of any hip prosthesis it is important to recreate joint centre. Normal joint centre is determined by horizontal
Background. Limb length discrepancy after total hip replacement is one of the possible complications of suboptimal positioning of the implant and cause of patients dissatisfaction. Computer assisted navigation become affirmed in last years for total hip replacement surgery and it is also used for the evaluation of the intra-operative limb length discrepancy. The purpose of this study is to verify the reliability of a navigation system with a dedicated software in intraoperative evaluation of limb lengthening and
Background: Leg length equality and femoral
In previous congress of ISTA in Hawaii, we reported the results about accuracy of the cup center position in our image-free navigation system. In the new version of our navigation system, leg elongation and
Femoral off-set is the perpendicular distance between femur longitudinal axle and the femoral head’s rotation’s centre. Femoral off-set influences following yardsticks: stability of the joint, range of movement (ROM), muscular forcibleness, solicitations on the femoral component and acetabular component’s usury. From numerous radiographies studies, is shown as off-set is not an indefeasible measure, but an average with a range of variability.
Introduction:. Revision total knee arthroplasty (TKA) can be very complex in nature with difficulties/obstacles involving bone and soft tissue deficits, visualization and exposure, as well as alignment and fixation. Auxiliary devices such as augmentation and
Hypothesis. The Synergy femoral component was introduced in 1996 as a second generation titanium proximally porous-coated tapered stem with dual
Introduction: Modular prostheses were first developed for use in total hip arthroplasty (THA) in the 1980s as a potential solution to the problem of leg length inequality. There is much literature discussing the advantages and disadvantages of modularity in THA but there are few studies directly comparing modular and non-modular prostheses and their accuracy in restoring normal anatomy. Our aim was to assess whether modularity in THA improves the restoration of femoral
INTRODUCTION. One of the main goals of total knee arthroplasty (TKA) is to restore an adequate range of motion. The posterior femoral
Purpose. Instability following total hip arthroplasty (THA) is an unfortunately frequent and serious problem that requires through evaluation and preoperative planning before surgical intervention. Prevention through optimal index surgery is of great importance, as the management of an unstable THA is challenging even for an experienced joints surgeon. However, even after well-planned surgery, a significant incidence of recurrent instability still exists. As you know Sir John Charnley is one of the first orthopaedic surgeons to address the issue of soft-tissue tensioning (STT) in the THA. Moreover leg-length discrepancy (LLD) after THA can pose a substantial problem for the orthopaedic surgeon. Such discrepancy has been associated with complications including nerve palsy, low back pain, and abnormal gait. The objective of this study is to assess hip instability of three different FOs in same patient undergoing THA during an operation. Methods. We performed 70 patients who had undergone unilateral THA using CT based navigation system at a single institution for advanced osteoarthoritis from May 2013 to May 2014. We used postero-lateral approach in all patients. After cup and stem implantation, we assessed soft tissue tensioning in THA during operation. Trial necks were categorized into one of three groups: standard femoral
The purpose of this study is to analyze what kind of pattern of change in each posterior femoral condyle allows for a greater degree of flexion after total knee arthroplasty (TKA). The flexion angle was assessed pre-operatively, and at 12 months after the surgery in 98 patients (106 knees) who underwent consecutive TKA. We used a quantitative 3 dimensional technique using computed tomography for the assessment of changes in both the medial and lateral femoral condylar
Introduction: Patients following resurfacing frequently remark about the natural feel of the resurfaced hip joint in contrast to those with total hip arthroplasty. Possible reasons for this include the larger femoral head size, conservation of bone and superior biomechanics of the implant with more accurate restoration of femoral
Background. Joint line, patellar height and posterior condylar
We have attempted to quantify the influence of clinical, radiological and prosthetic design factors upon flexion following knee replacement. Our study examined the outcome following 101 knee replacements performed in two prospective randomized trials using similar cruciate retaining implants. Multivariate analyses, after adjusting for age, sex, diagnosis and the type of prosthesis revealed that the only significant correlates for range of movement at 12-months were the difference in posterior condylar
Introduction: Dislocation is the most common complication resulting in re-operation after total hip arthroplasty. This study investigates the association between acetabular prosthesis position, changes in femoral
Introduction: The successful outcome from metal-on-metal hip resurfacing is partly dependent on the restoration of the natural biomechanics of the hip joint. Valid measurement of the geometry of the reconstructed hip is challenging using plain radiographs. CT is more accurate and precise yet rarely used to assess hip geometry. Our aims were 1) to quantify the agreement between radiographic and CT measurement of horizontal femoral
Purpose. We sought to determine whether there was a difference in the posterior condylar
Purpose: The Synergy femoral component was introduced in late 1996 as a second generation titanium proximally porous-coated tapered stem with dual
Introduction. The effect of each step of medial soft tissue release was assessed taking the expansion strength and patellar condition into account in five fresh frozen normal cadaver specimens. Methods. In each cadaver specimen, only proximal tibia was cut. Then, ACL was cut, and deep MCL fiber was released. This condition was set as “the basic”. Joint gap distance and angle were measured at full extension, 30°, 60°, 90°, 120° flexion and in full flexion. The measurement was firstly done with the standard tensor/balancer with the patella everted, and the next with the
Total Hip Replacement (THR) accounts among the successful procedures in orthopaedic surgery. It is reported that survival rate of implants can be as high as 93% at 20 years]. Nevertheless limb length inequality may result being the cause of major discomfort and dissatisfaction for patients. Additionally limb length inequality may also be recognised as a source of an abnormal force transmission through the replaced joint, contributing to early loosening and failure of the implants. Not only limb length but also restoration of best possible femoral
In pre-operative planning for total hip arthroplasty (THA), femoral
The Bernese Periacetabular Osteotomy (PAO) has become the established method for treating developmental dysplasia of the hip. In the 1990s, the surgical technique was modified to avoid postoperative cam impingement due to uncorrected head neck
Aim of the study was to analyse the modifications of the pre-op and post-op femoral off-set after cementless total hip replacement. During an 18-month period, from January 2015 to June 2016, we retrospectively analysed data of 79 (n = 81 hips) patients (M:F = 31:48), with an average age of 70.38 yrs ± 10.05, who consecutively affered to our Department and underwent cementless total hip replacement for primary osteoarthritis with Pinnacle Gription. TM. cup and Corail. TM. stem (Depuy). All cases of infections and revision surgery were excluded. Inclusion criteria: postero-lateral approach, 2 dedicated surgeons. All patients were clinically and radiographically evaluated at 4-months and 1-year postop. Preop and postop femoral off-set were calculated using Impax Agfa software. Average preop HHS was 46.7 ± 7.7; at 4-months post-op 86.4 ± 5.7; at 1-year post-op 90.0 ± 5 (the improvement had a statistically significant p-value). There was no statistical significant difference between the preop and postop off-set values obtained (t-student test). In 38 (46.9%) hips we increased the femoral off-set and we analysed using χ₂-test if there was a correlation with hip pain, HHS and dislocation. There was no statistical significance. Our overall results show good and excellent clinical results at 1 year follow-up in cementless total hip replacement. We believe that our pre-op digital planning of the implant and the
Introduction. The use of reverse total shoulder arthroplasty (RSA) is becoming increasingly common in the treatment of rotator cuff arthropathy. Standard RSA technique involves medialising the centre of rotation (COR) maximising the deltoid lever arm and compensating for rotator cuff deficiency. However reported complications include scapular notching, prosthetic loosening and loss of shoulder contour. As a result the use of Bony Increased
At a minimum of one year after operation, we studied 64 patients with 86 total hip arthroplasties (THA) by standard anteroposterior hip and pelvic radiographs and measurement of range of motion and of isometric abduction strength. The femoral
Purpose. The purpose of this study was to evaluate the postoperative maximal flexion of Robotic assisted TKA which does not increase the posterior condylar
Introduction. Despite improvements in prosthesis design, the clinical outcome of total hip arthroplasty still has 10% failure rate after 10 years. Component malpositioning can lead to instability, impingement, excessive wear and loosening. Computer-assisted procedures are expected to improve the accuracy of component positioning, and therefore the long-term outcome. We present an original hip navigation system that allows controlling leg lengthening,
[Objectives] Hallux valgus, dorsal sublaxation or dislocation of metatarsophalangeal joints and clawing of the lateral toes are seen frequently in patients with rheumatoid arthritis (RA). Resection arthroplasty of the metatarsophalangeal joints (MTP joints) are widely used to correct these forefoot deformities and the clinical results are almost good. However lateral toes tend to displace dorsally and painful callosity tends to recur. We used the metatarsal shortening
Purpose: The study objective was to measure ‘posterior condylar
We studied wear in the ultra-high-molecular-weight polyethylene
The femoroacetabular conflict is a recognized cause of hip pain in young patients. It is associated with rim tears. Two types of conflict have been described: impingement due to retroversion of the acetabulum and «cam effect» associated with insufficient head/neck
Purpose: The study objective was to measure ‘posterior condylar
Background: Previous studies reported that several kinematic parameters such as tibial posterior slope, joint line, and femoral posterior condylar
Introduction: Potential clinical advantages for using reverse shoulder prostheses, such as enhanced stability or function, can only be realized if adequate glenoid component fixation is achieved. This study evaluates fixation of uncemented reverse glenoid components during physiologic loading, including radiographic assessment of in vivo component position. The relationships between initial fixation, glenoid component design (offset and screw geometry) and baseplate position were established using in-vitro biomechanical tests. Methods: Clinical: Twelve patients received Reverse Shoulder Prostheses (RSP, Encore Medical). Six patients had good outcomes (ASES score >
95), whereas the remaining six patients had glenoid loosening. Patient follow-up radiographs were digitized and glenoid base-plate position relative to the scapular spine was measured using a computer-guided goniometer. Mechanical Tests: RSP glenoid components were inserted in-vitro into synthetic bone foam blocks with material properties similar to human cancellous bone. Baseplates were secured using the RSPs central screw and either four 3.5 mm standard cortical screws in countersunk peripheral holes or four 5.0 mm diameter screws in threaded peripheral holes to fully capture the screw in the baseplate. Glenosphere lateral
There are many previous reports dealing with the relationship between the abductor moment arm or femoral
Reverse Total shoulder arthroplasty (RTSA) has become an increasingly used solution to treat osteoarthritis and cuff tear arthropathy. Though successful there are still 10 to 65% complication rates reported for RTSA. Complication rates range over different reverse shoulder designs but a clear understanding of implant design parameters that cause complications is still lacking within the literature. In efforts to reduce complication rates (Implant fixation, range of motion, joint stiffness, and fracture) and improve clinical/functional outcomes having to do with proper muscle performance we have employed a computational approach to assess the sensitivity of muscle performance to changes in RTSA implant geometry and surgical placement. The goal of this study was to assess how changes in RTSA joint configuration affect deltoid performance. An approach was developed from previous work to predict a patient's muscle performance. This approach was automated to assess changes in muscle performance over 1521 joint configurations for an RTSA subject. Patient-specific muscle moment arms, muscle lengths, muscle velocities, and muscle parameters served as inputs into the muscle prediction scheme. We systematically varied joint center locations over 1521 different perturbations from the Overall muscle activity varied over 1521 different implant configurations for the RTSA subject. For initial elevation the RTSA subject showed at least 25% deltoid activation sensitivity in each of the directions of joint configuration change(Figure 1). Posterior deltoid showed a maximal activation variation of 84% in the superior/inferior direction(Figure 1c). Deltoid activation variations lie primarily in the superior/inferior and anterior/posterior directions. An increasing trend was seen for the anterior, lateral and posterior deltoid outside of the discontinuity seen at 28°(Figure 1). Activation variations were compared to subject's experimental data. Reserve actuation for all samples remained below 4Nm(Figure 2). The most optimal deltoid normalized operating length was implemented by changing the joint configuration in the superior/inferior and medial/lateral directions(Figure 3). Current shoulder models utilize cadaver information in their assessment of generic muscle strength. In adding to this literature we performed a sensitivity study to assess the effects of RTSA joint configurations on deltoid muscle performance in a single patient-specific model. For this patient we were able to assess the best joint configuration to improve the patients muscle function and ideally their clinical outcome. With this information improvements can be made to the surgical placement and design of RTSA on a patient-specific basis to improve functional/clinical outcomes while minimizing complications.