The optimal management of posterior malleolar ankle fractures, a prevalent type of ankle trauma, is essential for improved prognosis. However, there remains a debate over the most effective surgical approach, particularly between screw and plate fixation methods. This study aims to investigate the differences in outcomes associated with these fixation techniques. We conducted a comprehensive review of clinical trials comparing anteroposterior (A-P) screws, posteroanterior (P-A) screws, and plate fixation. Two investigators validated the data sourced from multiple databases (MEDLINE, EMBASE, and Web of Science). Following PRISMA guidelines, we carried out a network meta-analysis (NMA) using visual analogue scale and American Orthopaedic Foot and Ankle Score (AOFAS) as primary outcomes. Secondary outcomes included range of motion limitations, radiological outcomes, and complication rates.Aims
Methods
Several artificial bone grafts have been developed but fail to achieve anticipated osteogenesis due to their insufficient neovascularization capacity and periosteum support. This study aimed to develop a vascularized bone-periosteum construct (VBPC) to provide better angiogenesis and osteogenesis for bone regeneration. A total of 24 male New Zealand white rabbits were divided into four groups according to the experimental materials. Allogenic adipose-derived mesenchymal stem cells (AMSCs) were cultured and seeded evenly in the collagen/chitosan sheet to form cell sheet as periosteum. Simultaneously, allogenic AMSCs were seeded onto alginate beads and were cultured to differentiate to endothelial-like cells to form vascularized bone construct (VBC). The cell sheet was wrapped onto VBC to create a vascularized bone-periosteum construct (VBPC). Four different experimental materials – acellular construct, VBC, non-vascularized bone-periosteum construct, and VBPC – were then implanted in bilateral L4-L5 intertransverse space. At 12 weeks post-surgery, the bone-forming capacities were determined by CT, biomechanical testing, histology, and immunohistochemistry staining analyses.Aims
Methods
This study aimed to establish the optimal fixation methods for calcaneal tuberosity avulsion fractures with different fragment thicknesses in a porcine model. A total of 36 porcine calcanea were sawed to create simple avulsion fractures with three different fragment thicknesses (5, 10, and 15 mm). They were randomly fixed with either two suture anchors or one headless screw. Load-to-failure and cyclic loading tension tests were performed for the biomechanical analysis.Aims
Methods
The degree of cartilage degeneration assessed intraoperatively may not be sufficient as a criterion for patellar resurfacing in total knee arthroplasty (TKA). However, single-photon emission tomography/computed tomography (SPECT/CT) is useful for detecting osteoarthritic involvement deeper in the subchondral bone. The purpose of the study was to determine whether SPECT/CT reflected the cartilage lesion underneath the patella in patients with end-stage osteoarthritis (OA) and whether clinical outcomes after TKA without patellar resurfacing differed according to the severity of patellofemoral (PF) OA determined by visual assessment and SPECT/CT findings. This study included 206 knees which underwent TKA. The degree of cartilage degeneration was graded intraoperatively according to the International Cartilage Repair Society grading system. Subjects were classified into four groups according to the degree of bone tracer uptake (BTU) on SPECT/CT in the PF joint. The Feller's patella score and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were assessed preoperatively and postoperative 1 and 2 years.Introduction
Methods
Cigarette smoking has a negative impact on the skeletal system, causes a decrease in bone mass in both young and old patients, and is considered a risk factor for the development of osteoporosis. In addition, it disturbs the bone healing process and prolongs the healing time after fractures. The mechanisms by which cigarette smoking impairs fracture healing are not fully understood. There are few studies reporting the effects of cigarette smoking on new blood vessel formation during the early stage of fracture healing. We tested the hypothesis that cigarette smoke inhalation may suppress angiogenesis and delay fracture healing. We established a custom-made chamber with airflow for rats to inhale cigarette smoke continuously, and tested our hypothesis using a femoral osteotomy model, radiograph and microCT imaging, and various biomechanical and biological tests.Aims
Methods
Prosthetic joint infection (PJI) is the most common cause of arthroplasty failure. However, infection is often difficult to detect by conventional bacterial cultures, for which false-negative rates are 23% to 35%. In contrast, 16S rRNA metagenomics has been shown to quantitatively detect unculturable, unsuspected, and unviable pathogens. In this study, we investigated the use of 16S rRNA metagenomics for detection of bacterial pathogens in synovial fluid (SF) from patients with hip or knee PJI. We analyzed the bacterial composition of 22 SF samples collected from 11 patients with PJIs (first- and second-stage surgery). The V3 and V4 region of bacteria was assessed by comparing the taxonomic distribution of the 16S rDNA amplicons with microbiome sequencing analysis. We also compared the results of bacterial detection from different methods including 16S metagenomics, traditional cultures, and targeted Sanger sequencing.Objectives
Methods
Prosthetic joint infection (PJI) diagnosis is a major challenge in orthopaedics, and no reliable parameters have been established for accurate, preoperative predictions in the differential diagnosis of aseptic loosening or PJI. This study surveyed factors in synovial fluid (SF) for improving PJI diagnosis. We enrolled 48 patients (including 39 PJI and nine aseptic loosening cases) who required knee/hip revision surgery between January 2016 and December 2017. The PJI diagnosis was established according to the Musculoskeletal Infection Society (MSIS) criteria. SF was used to survey factors by protein array and enzyme-linked immunosorbent assay to compare protein expression patterns in SF among three groups (aseptic loosening and first- and second-stage surgery). We compared routine clinical test data, such as C-reactive protein level and leucocyte number, with potential biomarker data to assess the diagnostic ability for PJI within the same patient groups.Objectives
Methods
As the number of primary or revision TKA with stem extension cases are growing simultaneously, the number of periprosthetic fracture in these cases has also increased accordingly. However, there have been few reports on the classification and treatment of periprosthetic fracture following stemmed TKA and lack of information about the treatment outcome. The purposes of this study were 1) to demonstrate classification and management of periprosthetic fractures after stemmed TKA and 2) to report treatment outcome after the periprosthetic fractures. This retrospective study included 17 knees (15 patients) with an average age of 69.7 years. All cases were revision TKA cases, and there were 13 female and 2 male patients. The patients were treated nonoperatively or underwent operation by orthopedic principle. The period of union was evaluated by confirming the formation of callus crossing fragments in radiographs. We reviewed the complications and functional outcomes after treatment of periprosthetic fracture following revision TKA by assessing FF, FC and scoring WOMAC and KSS.Background
Materials and Methods
For the management of displaced patellar fractures, surgical fixation using cannulated screws along with anterior tension band wiring is getting popular. Clinical and biomechanical studies have reported that using cannulated screws and a wire instead of the modified tension band with Kirschner wires improves the stability of fractured patellae. However, the biomechanical effect of screw proximity on the fixed construction remains unclear. The aim of this study was to evaluate the mechanical behaviors of the fractured patella fixed with two cannulated screws and tension band at different depths of the patella using finite element method. A patella model with simple transverse fracture [AO 34-C1] was developed; the surgical fixation consisted of two 4.0-mm parallel partial-threaded cannulated screws with a figure-of-eight anterior tension band wiring using a 1.25-mm stainless steel cable. Two different locations, including the screws 5-mm and 10-mm away from the leading edge of the patella, were used. A tension force of 850 N was applied on the patellar apexes at two loading angles (45° and 0° [parallel] to the long axis) to simulate different loading conditions while knee ambulation. The proximal side (base) of the patella was fixed, and the inferior articular surface was defined as a compression-only support in ANSYS to simulate the support from distal femur condyles. Compression-only support enables the articular surfaces of the present patella to only bear compression and no tension forces. Under different loading conditions, the fixed fractured patella yielded higher stability during 0° loading of tension force than during 45° loading. When the screws were parallel placed at the depth of 5 mm away from the patellar surface, the deformation of patellar fragment and maximum gap opening at the fracture site were smaller than those obtained by screws placed at the depth of 10 mm away from the patellar surface. Compared to the superficial screw placement, the deeper placement (10 mm) increased the maximum gap opening at the fracture site by 1.56 times under 45° loading, and 1.58 times under 0° loading. The load on the tension band wire of the 10-mm screw placement was 3.12 times (from 230 to 717 N) higher than that of the 5-mm placement. Under the wire, the contact pressure on the patellar surface was higher with the 10-mm screw placement than the 5-mm screw placement. The peak bone contact pressures with the 10-mm placement were 7.7 times (99.5 to 764 MPa) higher. This is the first numerical study to examine the biomechanical effects of different screw locations on the fixation of a fractured patella using screws and tension band. Based on a higher stability and lower cable tension obtained by the superficial screws placement, the authors recommended the superficial screw placement (5 mm below the leading edge of the patella) rather than the deep screws while fixing the transverse patellar fracture with cannulated screws and cable.
Joint line, patellar height and posterior condylar offset (PCO) are related to functional outcome such as stability and range of motion after revision total knee arthroplasty (TKA). The purpose of this study was (1) to determine whether revision TKA can restore the joint line, patella height and condylar offset after surgery, and (2) to assess factors associated with failed restoration. We retrospectively reviewed 27 consecutive patients who underwent revision TKA. Among 27 patients, 11 patients had two-stage revision TKA due to periprosthetic joint infection while 14 patients underwent revision TKA due to aseptic loosening. In addition, there were 2 patients who had traumatic event causing a periprosthetic fracture which led to revision TKA. The joint line was measured using the distance from the adductor tubercle of the femur to the most distal portion of the medial femoral component on knee anterior-posterior radiographs. Patella height was assessed using the Caton-Deschamps method. In addition, PCO were measured relative to the tangent of the posterior cortex of the femur using knee lateral radiograph. All parameters were compared between pre- and postoperative radiographs after revision TKA.Background
Materials and Methods
With the introduction of new technology in orthopaedics, surgeons must balance anticipated benefits in patient outcomes with challenges or complications associated with surgical learning curve for the technology. The purpose of this study was to determine whether the surgeon learning curve with a new multi-radius primary TKA system (primary TKA implant and instruments) designed for surgical team ease would impact clinical outcomes, surgical time and complications. From November 2012 to July 2015, 2369 primary TKAs were prospectively enrolled in two multicenter studies across 50 sites in 14 countries with a new knee system (ATTUNE®) evenly balanced across four configurations: cruciate retaining or posterior stabilised with either fixed bearing or rotating platform (CRFB, CRRP, PSFB, PSRP). 2261 knees had a <1 year visit and 1628 had a greater than 1 year visit. These knees were compared to a reference dataset of 845 primary TKAs from three manufacturers in the same four configurations with currently available products (CURRENT-TKA). Demographics for ATTUNE and CURRENT-TKA were similar and typical for primary TKA. Operative times, clinical outcomes and a series of five patient reported outcomes were compared for ATTUNE vs. CURRENT-TKA. The first 10 ATTUNE subjects for each surgeon were defined as learning curve cases (N=520) and were compared to all later subjects (N=1849) and also with the CURRENT-TKA cases (N=845). Patient reported outcome measures and clinical outcome analyses were adjusted for covariates including patient demographics, pre-op assessment and days post-op.Introduction
Materials & Methods
With the introduction of new technology in orthopaedics, surgeons must balance anticipated benefits in patient outcomes with challenges or complications associated with surgical learning curve for the technology. The purpose of this study was to determine whether surgeon learning curve with a new multi-radius primary TKA system and instruments designed to improve surgical team ease would impact clinical outcomes, surgical time, and complications. From November 2012 to July 2015, 2369 primary TKAs were prospectively enrolled in two multicentre studies across 50 sites in 14 countries with a new knee system (NEW-TKA) evenly balanced across four configurations: cruciate retaining or posterior stabilised with either fixed bearing or rotating platform (CRFB, CRRP, PSFB, PSRP). 2128 knees had a<1 year visit and 1189 had a minimum 1 year visit. These knees were compared to a reference dataset of 843 primary TKAs from three manufacturers in the same four configurations with currently available products (CA-TKA). Demographics for NEW-TKA and CA-TKA were similar and typical for primary TKA. Operative times, clinical outcomes and a series of five patient reported outcomes were compared for NEW-TKA vs. CA-TKA. The first 10 New-TKA subjects for each surgeon were defined as learning curve cases (N=520) and were compared to all later subjects (N=1849). Patient reported outcome measure and clinical outcome analyses were covariate adjusted for patient demographics, pre-op assessment and days post-op. Mean (SD) surgical time for NEW-TKA learning curve cases was 79.1 (24.3) minutes, which reduced thereafter to 73.6 (24.3) (p=0.002). Beyond 10 cases, there was a continued reduction in NEW-TKA surgical time (R-Squared = 0.031). After 10 cases, surgical time was on par with the mean (SD) 71.9 (21.6) for CA-TKA (p=0.078). PROM outcomes of the first 10 learning curve cases for NEW-TKA were not statistically different from later cases at less than 1 year or later when adjusted for relevant covariates including configuration, patient demographics, pre-op functional status, and time post-op (p-values > 0.01). PROM outcomes for NEW-TKA vs. CA-TKA under the same covariate adjustments showed a trend favoring KOOS ADL, Symptoms, and Sport and Recreation subscores at minimum 1 year (p-values < 0.01). The incidence of intraoperative operative site complications was 1.3% for the NEW-TKA learning curve cases which was similar to the 0.6% rate for historical CA-TKA (p=0.231) and the intraoperative complication rate for the NEW-TKA later cases was consistent with learning curve cases (p=0.158). The introduction of new implants into the market place needs to have adequate data to support that they are safe and effective. Except for a minor increase in surgical time during the first 10 patients, this study found that surgeon learning curve with this new primary TKA system does not adversely affect patient short term outcomes and complication rates.
Deformity of knee joint causes deviation of mechanical axis in the coronal plane, and the mechanical axis deviation also could adversely affect biomechanics of the ankle joint as well as the knee joint. Particularly, most of the patients undergoing total knee arthroplasty (TKA) have significant preoperative varus malalignment which would be corrected after TKA, the patients also may have significant changes of ankle joint characteristics after the surgery. This study aimed 1) to examine the prevalence of coexisting ankle osteoarthritis (OA) in the patients undergoing TKA due to varus knee OA and to determine whether the patients with coexisting ankle OA have more varus malalignment, and 2) to evaluate the changes of radiographic parameters for ankle joint before and 4 years after TKA. We evaluated 153 knees in 86 patients with varus knee OA who underwent primary TKA. With use of standing whole-limb anteroposterior radiographs and ankle radiographs before and 4 years after TKRA, we assessed prevalence of coexisting ankle OA in the patients before TKA and analyzed the changes of four radiographic parameters before and after TKA including 1) the mechanical tibiofemoral angle (negative value = varus), 2) the ankle joint orientation relative to the ground (positive value = sloping down laterally), 3) ankle joint space, and 4) medial clear space.Introduction
Methods
Even a number of studies have reported clinical outcomes after revision total knee arthroplasty (revision TKA), little information is still available on whether outcomes of patients undergoing a revision TKA as a second stage procedure because of infected TKA are poorer than those of the patients undergoing a single-stage revision TKA because of non-infectious causes. In addition, use of various revision prostheses in most previous studies may limit solid interpretation of the outcomes after revision TKA. This study sought to determine whether outcomes in patients undergoing revision TKA due to infected TKA would be different from those in patients undergoing revision TKA due to non-infectious causes. We assessed 71 cases undergoing revision TKAs with use of a same revision system (Scorpio TS®, Stryker, Mahwah, NJ) from October 1999 to February 2012. All patients followed more than two years and mean follow-up period was 67 months (range: 24 – 168 months). Of them, thirty five patients underwent revisions due to infected TKA (group for infected TKA) while 36 patients due to non-infectious causes including loosening, wear, and/or instability (group for non-infected TKA). All patients in the group for infected TKA underwent two-stage revision surgeries while all patients in the group for non-infected TKA single stage revision surgeries. Comparative variables between two groups were preoperative range of motion (ROM) and American knee society (AKS) scores, postoperative ROM and AKS scores assessed at latest follow-up, amount of bone loss and requirement of stem assessed during the surgeries, and survival rate.Introduction
Materials and Methods
Total knee arthroplasty (TKA) is a proven treatment method for advanced knee arthritis in terms of pain relief, function restoration, and quality-of-life improvement. The TKA use has increased significantly over the past decade and the growing rate is more prominent in Asian countries. Thus, the revision TKA may also increase in recent days, which represents a burden to the national health care system. To the best of our knowledge, little information is currently available regarding the incidence and related factors of revision TKA in Asian countries on the basis of nationwide database. This study sought to find the incidence of revision TKA and related factors in South Korea using national database from 2007 to 2012. Data collected by the Health Insurance Review Agency of Korea, from 260,068 TKA patients between 2007 and 2012, were used to estimate the incidence of revision TKA according to age group, gender and hospital TKA and manufacturer prosthesis volume (i.e., the number of TKA procedures carried out at a given hospital, and the number of procedures performed using a given manufacturer's prosthesis, respectively). Age group and hospital and manufacturer volumes were categorized into three groups and TKA incidence rates were computed for groups stratified according to age, gender and hospital and manufacturer volumes.Introduction
Material and Method
Total knee arthroplasty(TKA) is a major surgery and the postoperative pain can be severe. Inadequate pain relief may lead to delayed mobilisation, greater risk of developing deep vein thrombosis, coronary ischemia, poor wound healing, longer hospital stay and decreased patient satisfaction. Severe postoperative pain also increase the risk of developing long term persisting pain. Conventional pain managements with intermittent parenteral opioids and non-steroid anti-inflammatory drugs have been proved to be less effective and are often lead to unwanted side effect. Currently, there is a trend to use multimodal pain management to minimize narcotic consumption and to avoid narcotic-related side effects. The use of transdermal opioid patch has not been well established. The purpose of this study was to investigate the analgesic effects of various transdermal non-opioid patches in patients after elective total knee arthroplasty in a prospective, randomised control trial. After receiving Institutional Review Board approval, 89 patients(89 knees) received primary unilateral total knee arthroplasty were included in this study. All patients were randomly allocated into three groups. The 3 groups were demographically similar for sex, age, and body mass index. They received patches with 5% lidocaine, flurbiprofen and only vehicle patches without any medication. The patches were placed on the tourniquet area postoperatively, then on patient-directed area of discomfort every 6–8 hours. Each patient received the same standard postoperative analgesics including single intra-articular injection, NSAID, acetaminophen, and rescue opioids as needed. All patients were interviews everyday and the primary outcome was the visual analog scale. Besides, consumption of rescue opioids, progress of active movement, and inpatient stay were also recorded. Our hypotheses were transdermal non-opioid patches would provide effective pain relief and reduce the consumption of opioids as well as their side effects. There were 30, 29, and 30 patients in group I, II and III. The mean ischemic time(tourniquet time) was 56.0, 61.4, 55.5 minutes, respectively. The narcotics consumptions were 11.77, 20.12, and 15.57 mg, respectively. The day achieved active flexion to 90 degrees were 1.83, 1.97, and 2.03 days, respectively. The inpatient stay was 6.47 days for group I patients, 6.81 days for group II patients, and 6.77 days for group III patients. The mean episodes of breakthrough pain(VAS>4) were 3, 3, and 3.7 times, respectively. There was no related adverse effects occurred with the use of non-opioid trasndermal patches. Compared to placebo group, favourable results were noted in non-opioid transdermal patches, including opioid consumption, active knee flexion, inpatient stay and episodes of breakthrough pain in spite of insignificant statistical difference. High satisfaction without any complication were noted. Besides, non-opioid transdermal patches are also cost effective. There were only a few literature discussing about non-opioid patches in patients with total knee arthroplasty. The results showed indifferent pain improvement and no significant additional pain relief. Our results were compatible with current related studies, which showed no significant improvement. This is the first study to compare the analgesic efficacy of different non-opioid tansdermal patches in a prospective randomised trial.
Infection is a potentially disastrous complication of total knee arthroplasty (TKA). Although advances in surgical technique and antibiotic prophylaxis have reduced the incidence of infection to approximately 1% in primary TKA, there is still a substantial number of patients. Treatment options include antibiotic suppression, irrigation and debridement with component retention (with or without polyethylene exchange), one-stage or two-stage revision, resection arthroplasty and rarely arthrodesis or amputation. Salvage of prostheses has always been associated with low rates of success. It was reported a success rate of 27% for open debridement. It is suitable for selective cases where infection occurs within the first 4–6 weeks of primary TKA or in the setting of acute hematogenous gram positive infection with stable implants. With the advances in arthroscopic technique, arthroscopy after TKA has become an accepted method to assess and manage the complications of TKA. Arthroscopic treatment for infected TKA was reported and the successful rate was similar or better than open debridement in selected situations. We used arthroscopic debridement combined with continuous antibiotic irrigation and suction to treat acute presentation of infected TKA with acceptable result. From 2010∼2013, we has performed arthroscopic debridement and continuous antibiotic irrigation system for seven patients with infected TKA. All of the seven patients had no open wounds nor sinuses and no radiological evidence of prosthetic instability or evidence of osteomyelitis. Most of the surgical intervention was performed within two weeks from the onset of symptoms. Arthroscopic debridement was performed with a shaver using a multiportal technique (anterolateral, anteromedial, superolateral, superomedial, posterolateral, posteromedial) and a continuous antibiotic irrigation system was used to dilutes concentration of the causative microorganism and keep high local bactericidal concentration of antibiotics. We evaluated the efficacy by using follow up of the C-reactve protein (CRP) test, erythrocyte sedimentation rate (ESR) test and physical examination. Successful treatment was defined as prosthesis retention without recurrent infection by the final follow-up. Six of seven infected TKA were cured without recurrence at a mean follow-up of 23 months (range, 6–41 months). One case with rheumatoid arthritis under long-term steroid therapy had recurred after episode of upper respiratory tract infection for 3 times. However, the infection was controlled by arthroscopic debridement and retention of the prosthesis was achieved. We emphasize the importance of posterior portal to ensure adequate arthroscopic debridement. It is imperative to make early diagnosis and treatment for infected TKA. We should make more effort to preserve the prosthesis in acute infection(within 2 weeks). With the advantage of minimal morbidity, arthroscopic treatement shoulder be an alternative to open debridement.
TKR is a standard procedure for knee joint falure. Besides surgical technique, the main concerns at the perioperative care are: infection prophylaxis, blood loss management, & pain control. Pain is a normal part during the post-operative recovery stage. Currently, I apply multimodal pain control cocktails: Parenteral narcotics (as pethidine, tramadol, morphine), oral analgesics (as NSAIDs, Acetaminophen, opioids), PCA (Patient controlled analgesia), LIA (local IA injection anesthetics, Marcaine), and immediate Ice Packing. How about the usage of transdermal, non-opioid devices as Lidocaine patch. It shows the advantages of: less invasiveness, less ambulation-impeding, easy monitor & control, patient-activated, and absence of opioid-induced complications. Also it can be an adjuvant in the multi-modal anesthesia. In this Randomized prospective study, we investigate the analgesic effects of various transdermal non-opioid patches in patients after elective TKR The use of non-opioid transdermal patches is a safe and patient-activated method. Non-opioid transdermal patches show NSD improvement in the postoperative pain control for patients underwent TKA, facilitating fewer narcotics consumption, fewer breakthrough pain, faster recovery in movements and even shorter stay. However, without obvious differences, the routine use of transdermal patches in current pain control protocol should be trade-off.Conclusion
Total knee arthroplasty [TKA] is a common procedure to relieve painful disability from advanced knee arthritis. However, related blood loss, ranging from 800 to 1200 ml, increase risk and disruption of recovery in anemic patients following TKA. Various methods for blood conservation had been proposed and examined. In the literature, the intra-articular administration of a solution mixing bupivacaine and epinephrine was commonly used after knee surgeries. Therefore, we conducted a retrospective, case controlled review of our primary TKAs to determine the hemostatic efficacy of this regimen following TKAs. Over a period of 12 months, 135 eligible patients were divided two groups simply according to the intra-articular injection or not: a control group (N=63) and a treatment group (N=72). In the treatment group, a 40 ml vial of 0.5% bupivacaine with epinephrine 1: 200000 was given prior to the deflation of pneumatic tourniquet. No drainage was used in all TKAs. Without recordable drainage, a Gross formula, considering gender and body composition, was used for estimate blood loss following TKAs. In addition, serial changes in hemoglobin as well as the requirement of allogenic transfusion were also compared between groups.Introduction
Material and Methods
Cannulated screw is commonly used in the fixation of proximal femoral neck fractures. In the literature, several configurations had been proposed for best mechanical support with clinical experiences or biomechanical tests. Although screws in triangle configuration contribute certain fixation stability, but sometimes the surgeons made their own choices have to conduct another fixation pattern for some factors such as fracture type, economic issues, and so on. Therefore the aim of this study is to analyze the mechanical responses of a fractured femur fixed with screws in different configurations, screw materials and screw diameters with finite element method, trying to find the most stable construct. A solid femur model was built from the CT images of a standard saw bone. Three fracture types of the femoral neck were created according to Pauwel's classification (30?, 50?, 70?) by CAD software. The models of implanted screws were built according to a commercial cannulated screw (Stryker Osteosynthesis, Schoenkirchen/Kiel, Germany) with diameter 6.5mm and 4.5mm by CAD software, too. Three fixation configurations were analyzed in this study, including triangle with superior single screw with titanium diameter 6.5mm, triangle with inferior single screw with diameter 6.5mm and diamond with four stainless screw diameter 4.5mm (fig.1). Totally there were nine models constructed in this study, and all of them were then imported into ANSYS WORKBENCH v14 (Swanson Analysis, Houston, PA, USA) to mesh and further analysis. 700N vertical downward force was applied on the femur head and the distal end of femur shaft was totally fixed. The triangle fixation with superior single screw resulted in a best stability, but the fracture fixed with screws in a diamond configuration has least fracture gap. The difference of the maximum displacement of the femur head with Pauwel's classification 70?between triangle fixation with superior single screw and diamond configuration is only 0.03mm (1.72–1.69 mm). In most unstable femoral neck fracture [Pauwel's classification 70], the maximum gap distance is 0.59mm under the diamond configuration, while it is 0.63mm as the fracture fixed with a triangle configuration. Therefore, this study suggests that four 4.5mm stainless screws in a diamond configuration is an alternative for proximal femur fracture once 6.5mm titanium screws are not available.
Persistent problems and relatively high complication rates with reverse total shoulder arthroplasty (RTSA) are reported (1, 2). It is assumed that some of these complications are affected by improper intraoperative soft tissue tension. Achieving proper intraoperative soft tissue tension is an obvious surgical goal. However, intraoperative soft tissue tension measurements and methods for RTSA have not been reported. One way to quantify soft tissue tension is to measure intraoperative joint forces using an instrumented prosthesis. Hence, we have developed an instrumented RTSA to measure shoulder joint forces intraoperatively. The goal of this study was to measure intraoperative shoulder joint forces during RTSA. The instrumented shoulder prosthesis measures the contact force vector between the glenosphere and humeral tray. This force sensor is a custom instrumented trial implant that can be used with an existing RTSA system (EQUINOXE, Exactech Inc, Gainesville, FL) just as a standard trial implant is used. Four uniaxial foil strain gauges (QFLG-02-11-3LJB, Tokyo Sokki Kenkyujo Co., Ltd., JP) are instrumented inside the sensor. Using a calibration matrix, the three force components were calculated from four strain gauge outputs (3). Sixteen patients who underwent RTSA took part in this IRB approved study. All patients were greater than 50 years of age and willing to review and sign the study informed consent form. After obtaining informed consent for surgery, a standard deltopectoral approach to the shoulder was performed. The instrumented trial prostheses were assembled on the glenoid baseplate instead of a standard glenosphere. After the joint was reduced, joint forces were recorded during cyclic rotation, flexion, scapular plane movement (scaption), and adduction of the shoulder. Strain gauge outputs were recorded during these movements as well as the neutral position just before movements. Mean values of forces with each motion were compared by one-way analysis of variance (ANOVA). A multiple comparisons test was subsequently performed to examine differences between motions.Introduction
Materials and Methods
In a previous study, we found that pre-TKA patients were severely disabled in high-flexion activities but perceived these disabilities as being no more important than pain relief and the restoration of daily routine activities. This study was conducted to investigate functional disabilities and patient satisfaction in Korean patients after TKA. Of 387 patients who had undergone TKA with a follow-up longer than 12 months, 270 (69.7%) completed a questionnaire designed to evaluate functional disabilities, perceived importance and patient satisfaction. The top 5 severe functional disabilities were difficulties in kneeling, squatting, sitting with legs crossed, sexual activity, and recreational activities. The top 5 in order of perceived importance were difficulties in walking, using a bathtub, working, climbing stairs, and recreation activities. Severities of functional disabilities were not found to be correlated with perceived importance. The patients (8.5%) dissatisfied with their replaced knees had more severe functional disabilities than the satisfied for most activities. The dissatisfied patients tended to perceive functional disabilities in high-flexion activities to be more important than the satisfied. This study indicates that despite severe disabilities in high-flexion activities, most Korean patients after TKA would not consider high-flexion disability to be more important than other daily routine activities. Moreover, postoperative high-flexion disabilities would not adversely influence satisfaction for most patients. Nevertheless, such disabilities are likely to cause dissatisfaction among those that are not prepared to modify their traditional life-styles.
Despite the well-documented improvement in coronal alignment achieved by computer assisted navigation, varying results have been reported for sagittal alignment. Current navigation systems rely on a sagittal femoral mechanical axis identified by the navigation system, but little information is available on the relationship between the sagittal mechanical axis and anatomical axes for intra-operative or postoperative radiographic assessments. We asked whether deviations exist between sagittal femoral mechanical axis and anatomical axes and attempted to identify predictors of the deviations found. In 100 consecutive patients (200 knees) undergoing TKA, angles between two anatomical axes (the anterior cortical line and mid-medullary line) and two sagittal mechanical axes identified by current navigation systems were measured as proxies of the deviations between them on true lateral radiographs of the whole femur. Correlation analyses and multivariate regression were carried out to identify predictors of deviations. Significant deviations existed with wide ranges between the anatomical axes and the sagittal mechanical axes. Degree of femoral bowing and femoral length were found to be predictors of deviations between sagittal femoral mechanical axes and anatomical axes. This study suggests that surgeons applying navigation technology to TKA need to consider deviations between the sagittal femoral mechanical axes and anatomical axes when they intend to place a femoral component at a target sagittal orientation with respect to an anatomical reference.
Achieving precise component alignment of total knee arthroplasty produces good clinical outcome. However, the cutting errors between planed and final bone resection planes during the procedure of total knee arthroplasty were less evaluated. The aim of this study was to evaluate the cutting errors during total knee arthroplasty using the navigation system. In a prospective series of 60 total knee replacements with image-free navigation system, the planed resection plane and final resection plane in frontal and sagittal planes were evaluated. The cutting errors standard deviations ranged from 1.01° to 1.21° in final frontal femoral and tibia plane and 1.23° in final sagittal femoral and tibia plane. The cutting errors showed only significant difference in the sagittal plane of femoral resection and only 9 cuts (4%) 3 of all plane and the maximal error was 4 in only 2 cases (0.8%). Our results support to use the navigation system to adjust the cutting block and correct the cutting errors. This would lead to a more precise cut and result in better leg alignment and component orientation than the conventional TKR technique.
Application of computer assisted navigation (CAN) has been documented to improve the accuracy of limb alignment and implant positioning. However, a recent study reported that a great deal of disparities occurred between the radiographic and navigational measurements calling the basic argument for application of CAN to TKA into question. In the authors’ practice using CAN for TKA, we have observed consistent disparities between the preoperative radiographic assessments and intraoperative navigational assessments of limb alignment in the coronal plane. A large disparity between radiographic and navigational assessments of limb alignment would be presenting a challenging question whether or not the surgeon can rely on the information provided by the CAN system. We developed a novel method to measure the coronal limb alignment and have found that the radiographic measurements with the novel method remarkably reduce the disparities between the radiographic and navigational assessments of the coronal limb alignment. This study was conducted to document the existence of the disparities between the radiographic and navigational assessments of the limb alignment and the value of our novel method to perform preoperative radiographic measurements of limb alignment. In 107 TKAs performed using a CAN system (Ortho-pilot: B. Braun-Aesculap, Tuttlingen, Germany), radiographic assessments of coronal limb alignment were assessed using preoperative and postoperative whole limb radiographs taken with weight bearing with two different methods: a standard method, angle between the femoral mechanical axis (the line connecting hip center and the top pint of the femoral intercondylar notch) and a tibial mechanical axis (the line connecting the mid-point between the medial and lateral tibial eminences and the mid-point of the talus dome) and a novel method, the angle between the weight loading line (the line connecting the hip center and the mid-point of the talus dome) and the tibial mechanical axis. A negative value was given to a varus alignment and a positive value to the valgus alignment. During surgery, the coronal limb alignment was measured by the navigation system two different time-points: after registration and after implantation of prostheses. The disparity between the radiographic and navigational assessments was calculated with subtracting the radiographic assessments by the navigational assessments. The disparity between the radiographic and navigational assessments was significantly smaller with the novel method than with the standard method. The mean difference between the radiographic and navigational assessments of preoperative limb alignment was −6.5o (range: −19 ~ 1) with the standard method and −0.9o (range: −8o to 4o) with the novel method. The mean difference between the radiographic and navigational assessments of the postoperative limb alignment was −1.96 (range: −11 ~ 3) with the standard method and −1.3 (range: −6 ~3). This study documents that a wide range of disparities occurs between the radiographic and navigational assessments of limb alignment and the amount of disparity occurs in preoperative assessments. Our findings indicate that our novel method to perform the radiographic assessments of limb alignment can be a useful tool to interpret the information intraoperatively given by the navigation system.