Patient-reported health outcomes after total hip and knee surgery in a Dutch University Hospital Setting: results of twenty years clinical registry.

BACKGROUND: Patient-Reported Outcome (PRO) measurement is a method for measuring perceptions of patients on their health and quality of life. The aim of this paper is to present the results of PRO measurements in total hip and knee replacement as routinely collected during 20 years of surgery in a university hospital setting. METHODS: Data of consecutive patients between 1993 and 2014 were collected. Health outcomes were measured pre-surgery and at 3, 6, and 12 months post-surgery. Outcomes for hip replacement were measured with the Harris Hip Score (HHS) and Oxford Hip Score (OHS). Outcomes for knee replacement were measured with the Western Ontario and McMaster Universities Arthritis Index (WOMAC) and the Knee Society Score (KSS). A Visual Analog Scale (VAS) for pain was used. Absolute and relative Minimal Clinically Important Differences (MCID) were estimated. Generalized estimating equation analysis was used for estimating mean outcomes. Trends over time were analyzed. RESULTS: The database contained 2,089 patients with hip replacement, and 704 patients with knee replacement. Mean HHS and OHS scores in primary hip replacement at 12 months post-surgery were 86.7 (SD: 14.5) and 41.1 (SD: 7.5) respectively. Improvements on the HHS based on absolute MCID was lower for revisions compared to primary hip replacements, with 72.4% and 87.0% respectively. Mean WOMAC and KSS scores in knee replacement at 12 months post-surgery were 21.5 (SD: 18.2) and 67.0 (SD: 26.4) respectively. Improvements based on absolute MCID were lowest for the KSS (62.6%) and highest for VAS pain (85.6%). Trend analysis showed a difference in 1 out of 24 comparisons in hip replacement and in 2 out of 9 comparisons in knee replacement. CONCLUSIONS: The functional status of a large cohort of patients significantly improved after hip and knee replacement based on routine data collection. Our study shows the feasibility of the routine collection of PRO data in patients with total hip and knee replacement. The use of PRO data provides opportunities for continuous quality improvement.

The effect of pregabalin and s-ketamine in total knee arthroplasty patients: A randomized trial.

BACKGROUND AND AIMS: Pain reduction is important for rehabilitation after total knee arthroplasty. Intra- and peri-articular infiltration with local anesthetics may be an alternative to commonly used locoregional techniques. Adding pregabalin orally and s-ketamine intravenously may further reduce postoperative pain. MATERIAL AND METHODS: This prospective, randomized, double-blind, placebo-controlled study compared two methods of perioperative analgesia. Control patients received a standardized multimodal postoperative analgesic regime of paracetamol, diclofenac, and piritramide-patient-controlled analgesia, including ropivacaine knee infiltration during surgery. The study group received pregabalin orally and s-ketamine intravenously as an additional medication to the standard multimodal regimen. The control group received placebo. RESULTS: The study group showed lower piritramide consumption during the first 24 h (P: 0.043), but with more side effects such as diplopia and dizziness. CONCLUSION: Addition of pregabalin and s-ketamine resulted in lower piritramide consumption during the first 24 h postoperatively. However, more investigation on benefits versus side effects of this medication is required.

FE analysis of the effects of simplifications in experimental testing on micromotions of uncemented femoral knee implants.

Experimental testing of orthopaedic implants requires simplifications concerning load application and activities being analyzed. This computational study investigated how these simplifications affect micromotions at the bone-implant interface of an uncemented femoral knee implant. As a basis, validated in vivo loads of the stance phase of gait and a deep knee bend were adopted. Eventually, three configurations were considered: (i) simulation of the complete loading cycle; (ii) inclusion of only tibiofemoral loads (ignoring patellofemoral loads); and (iii) applying only a single peak tibiofemoral force. For all loading conditions the largest micromotions found at the proximal anterior flange. Without the patellofemoral force, peak micromotions increased 6% and 22% for gait and deep knee bend, respectively. By applying a single peak tibiofemoral force micromotions were overestimated. However, the peak micromotions corresponded to the maximum tibiofemoral force, and strong micromotion correlations were found between a complete loading cycle and a single peak load (R(2) = 0.73 and R(2) = 0.89 for gait and deep knee bend, respectively). Deep knee bend resulted in larger micromotions than gait. Our study suggests that a simplified peak force can be used to assess the stability of cementless femoral components. For more robust testing, implants should be subjected to different loading modes. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:812-819, 2016.

The effect of surface morphology on the primary fixation strength of uncemented femoral knee prosthesis: a cadaveric study.

We investigated the effect of surface morphology on the mechanical performance of uncemented femoral knee prosthesis. Eighteen implants were implanted on nine paired femurs and then pushed-off (left legs: a novel surface morphology; right legs: Porocoat as baseline). Bone mineral density (BMD) and anteroposterior dimension were not significantly different between groups. The insertion force was not significantly different, however, the loosening force was significantly higher in the novel group (P=0.007). BMD had a direct relationship with the insertion and loosening force (P<0.001). The effect of surface morphology on implant alignment was very small. We conclude that the surface properties create a higher frictional resistance, thereby providing a better inherent stability of implants featuring the novel surface morphology.

An experimental study to investigate biomechanical aspects of the initial stability of press-fit implants.

Initial fixation of press-fit implants depends on interference fit, surface morphology, and bone material properties. To understand the biomechanical effect of each factor and their interactions, the pull-out strength of seven types of CoCrMo tapered implants, with four different interference fits, three different surface morphologies (low, medium and high roughness), and at two time points (0 and 30 min) were tested in trabecular bone with varying density. The effect of interference fit on pull-out strength depended on the surface morphology and time. In contrast with our expectations, samples with a higher roughness had a lower pull-out strength. We found a similar magnitude of bone damage for the different surface morphologies, but the type of damage was different, with bone compaction versus bone abrasion for low and high frictional surfaces, respectively. This explains a reduced sensitivity of fixation strength to bone mineral density in the latter group. In addition, a reduction in fixation strength after a waiting period only occurred for the low frictional specimens. Our study demonstrates that it is essential to evaluate the interplay between different factors and emphasizes the importance of testing in natural bone in order to optimize the initial stability of press-fit implants.

Treatment changes and improved outcomes in RA: an overview of a large inception cohort from 1989 to 2009.

OBJECTIVE: The introduction of effective treatment strategies in the past two decades has changed the management of RA dramatically. The objective was to analyse the changes in disease activity, function, joint damage and incidence of orthopaedic surgery over a period of 20 years (1989-2009) for patients with RA. METHODS: Data acquired from 1989 to 2008 inclusive from the Nijmegen RA inception cohort were studied. By repeated measures analysis the course of the population mean disease activity score (DAS28) and the Health Assessment Questionnaire-Disability Index (HAQ-DI) corrected for age, gender, RF and disease duration was determined. Orthopaedic interventions were analysed as incidence rates with a Poisson distribution. We calculated the prevalence of the various therapies that patients were receiving. RESULTS: By 2009, 992 patients with RA had been included and 273 had been excluded. From 1989 onwards, the proportion of patients using MTX increased from 5% (8 of 164) to 62% (486 of 780), and biologic response modifiers from 0% to 22% (168 of 780) in 2008. The average MTX dosage increased to 16.1 ± 5.5 mg/week in 2008. The mean DAS28 (3.1) and HAQ-DI (0.47) were least (P < 0.008) in 2008 compared with previous years. There was a significant trend towards lower incidence rates of orthopaedic intervention in the period 2006-2008 than in almost all previous years. CONCLUSION: Treatment strategy changed in a large inception cohort of patients with RA which coincided with decreased disease activity, increased functional ability and fewer orthopaedic interventions since the early 1990s.

Loosely-guided, self-directed learning versus strictly-guided, station-based learning in gross anatomy laboratory sessions.

Anatomy students studying dissected anatomical specimens were subjected to either a loosely-guided, self-directed learning environment or a strictly-guided, preformatted gross anatomy laboratory session. The current study's guiding questions were: (1) do strictly-guided gross anatomy laboratory sessions lead to higher learning gains than loosely-guided experiences? and (2) are there differences in the recall of anatomical knowledge between students who undergo the two types of laboratory sessions after weeks and months? The design was a randomized controlled trial. The participants were 360 second-year medical students attending a gross anatomy laboratory course on the anatomy of the hand. Half of the students, the experimental group, were subjected without prior warning to station-based laboratory sessions; the other half, the control group, to loosely-guided laboratory sessions, which was the course's prevailing educational method at the time. The recall of anatomical knowledge was measured by written reproduction of 12 anatomical names at four points in time: immediately after the laboratory experience, then one week, five weeks, and eight months later. The strictly-guided group scored higher than the loosely-guided group at all time-points. Repeated ANOVA showed no interaction between the results of the two types of laboratory sessions (P = 0.121) and a significant between-subject effect (P ≤ 0.001). Therefore, levels of anatomical knowledge retrieved were significantly higher for the strictly-guided group than for the loosely-guided group at all times. It was concluded that gross anatomy laboratory sessions with strict instructions resulted in the recall of a larger amount of anatomical knowledge, even after eight months.

Does high-flexion total knee arthroplasty promote early loosening of the femoral component?

High-flexion knee replacements have been developed to accommodate a large range of motion (RoM > 120°). Knee implants that allow for higher flexion may be more sensitive to femoral loosening as the knee load is relatively high during deep knee flexion, which could result in an increased failure potential at the implant-cement interface of the femoral component. A 3D finite element knee model was developed including a posterior-stabilized high-flexion knee replacement to analyze the stress state at the femoral implant-cement interface during a full squatting movement (RoM ≤ 155°). During deep flexion (RoM > 120°), tensile and shear stress concentrations were found at the implant-cement interface beneath the proximal part of the anterior flange. Particularly, the shear stresses at this interface location increased during high flexion, from a peak stress of 4.03 MPa at 90° to 6.89 MPa at 140° of flexion. Tensile stresses were substantially lower, having a peak stress of 0.72 MPa at 100° of flexion. Using data from earlier interface strength experiments, none of the interface beneath the anterior flange was predicted to fail in the normal flexion range (RoM ≤ 120°), whereas the prediction increased to 2.2% of the interface during deeper knee flexion. Thigh-calf contact reduced the knee forces, interface load, and failure risk beyond 140-145° of flexion. Based on the more critical stresses at the femoral fixation site between 120° and 145° of flexion, we conclude that the femoral component has a higher risk of loosening at high-flexion angles.

[Open lateral clavicle resection in acromioclavicular osteoarthritis: favourable results after 1 year]. / Open laterale clavicularesectie bij acromioclaviculaire artrose: gunstige resultaten na 1 jaar.

OBJECTIVE: To determine the follow-up outcomes of open lateral clavicle resection 1 year postoperatively in patients with acromioclavicular osteoarthritis. The operation involves resection of a small part of the lateral clavicle. DESIGN: Prospective descriptive. METHOD: Data were collected from all patients who had undergone an open lateral clavicle resection in the period July 1999 to June 2008 and who were examined preoperatively and 1 year postoperatively. This concerned 23 operations in 22 patients. The Constant score for the functionality of the shoulder was determined and visual analogue scales (VAS) were used to determine the pain and satisfaction concerning the operated shoulder. The results were evaluated with the paired t-test and the non-parametric Wilcoxon test. RESULTS: The mean length of the lateral clavicle resection was 7.8 mm. Preoperatively the mean Constant score was 64 (SD: 14) and 1 year after the operation 86 (SD: 14; p < 0.001). Ninety-one percent had an increase in the postoperative Constant score compared with the preoperative score. The median VAS score for pain decreased from 70 (95% CI: 60-77) preoperatively to 25 (0-48) 1 year postoperatively (p < 0.001). The median VAS score for satisfaction increased from 40 (40-50) preoperatively to 85 (68-100) (p < 0.001). CONCLUSION: The open lateral clavicle resection was a treatment option to reduce the symptoms in patients with acromioclavicular osteoarthritis in whom conservative treatment and medication proved to be insufficient.

Unsuspected sonographic findings in patients with posttraumatic shoulder complaints.

PURPOSE: To prospectively assess the frequency of abnormal sonographic findings in patients with posttraumatic shoulder pain and/or disability in whom ultrasound (US) was not considered and to assess the effect of sonographic findings on working diagnosis and therapeutic strategy, to analyze the possible role of US in the diagnostic workup of these patients. METHODS: A survey was performed under general practitioners and orthopedic surgeons. They were requested to refer patients with persistent posttraumatic complaints for an US examination of the shoulder and to fill out a questionnaire concerning working diagnosis and therapy. In 50 patients examinations were performed separately by two radiologists. Findings were confirmed with additional radiographs and/or MRI and/or surgery. Four weeks after the US examination, the survey was repeated to inquire about changes in diagnosis and/or treatment that resulted from US. RESULTS: US showed relevant pathology in 45 (90%) of 50 patients, a proximal humerus fracture in 25 (50%) patients, and a rotator cuff tear in 43 (86%) patients. Twenty-three (92%) fractures were accompanied by a rotator cuff tear, and 23 (54%) rotator cuff tears were accompanied by a fracture. Ten fractures were initially missed radiographically. US findings changed the working diagnosis and therapeutic strategy in 37 (74%) and 26 (52%) patients, respectively. CONCLUSION: In patients with posttraumatic shoulder complaints, US showed a high rate (90%) of relevant pathology. This changed the initial working diagnosis in 74% of the patients and the therapeutic strategy in more than half of the patients. Active referral for US examination may identify these abnormalities in an earlier phase and improve clinical outcome.

Conversion of failed ankle arthroplasty to an arthrodesis. Technique using an arthrodesis nail and a cage filled with morsellized bone graft.

Arthrodesis of the ankle joint after a failed ankle prosthesis is most often demanding because of bone loss. The bone loss is also responsible for limb length discrepancy. Intramedullary nail fixation has been described to be successful for arthrodesis of the arthritic ankle joint. We report the use of the nail technique in combination with a morsellized bone graft in and around a cage to convert failed ankle prosthesis with bone loss into an arthrodesis. The advantages which were strived for include developing a more practical operative method with lower morbidity (no autograft), early mobilization and weight-bearing provided by the stability of the internal fixation and restoration of limb length.

A sliding stem in revision total knee arthroplasty provides stability and reduces stress shielding.

BACKGROUND AND PURPOSE: In the reconstruction of unicondylar femoral bone defects with morselized bone grafts in revision total knee arthroplasty, a stem extension appears to be critical to obtain adequate mechanical stability. Whether stability is still assured by this reconstruction technique in bicondylar defects has not been assessed. The disadvantage of relatively stiff stem extensions is that bone resorption is promoted due to stress shielding. We therefore designed a stem that would permit axial sliding movements of the articulating part relative to the intramedullary stem. METHODS: This stem was used in the reconstruction with impaction bone grafting (IBG) of 5 synthetic distal femora with a bicondylar defect. A cyclically axial load was applied to the prosthetic condyles to assess the stability of the reconstruction. Radiostereometry was used to determine the migrations of the femoral component with a rigidly connected stem, a sliding stem, and no stem extension. RESULTS: We found a stable reconstruction of the bicondylar femoral defects with IBG in the case of a rigidly connected stem. After disconnecting the stem, the femoral component showed substantially more migrations. With a sliding stem, rotational migrations were similar to those of a rigidly connected stem. However, the sliding stem allowed proximal migration of the condylar component, thereby compressing the IBG. INTERPRETATION: The presence of a functional stem extension is important for the stability of a bicondylar reconstruction. A sliding stem provides adequate stability, while stress shielding is reduced because compressive contact forces are still transmitted to the distal femoral bone.

Detection of rotator cuff tears: the value of MRI following ultrasound.

OBJECTIVE: To evaluate the need for additional magnetic resonance imaging (MRI) following ultrasound (US) in patients with shoulder pain and/or disability and to compare the accuracy of both techniques for the detection of partial-thickness and full-thickness rotator cuff tears (RCT). METHODS: In 4 years, 5,216 patients underwent US by experienced musculoskeletal radiologists. Retrospectively, patient records were evaluated if MRI and surgery were performed within 5 months of US. US and MRI findings were classified into intact cuff, partial-thickness and full-thickness RCT, and were correlated with surgical findings. RESULTS: Additional MR imaging was performed in 275 (5.2%) patients. Sixty-eight patients underwent surgery within 5 months. US and MRI correctly depicted 21 (95%) and 22 (100%) of the 22 full-thickness tears, and 8 (89%) and 6 (67%) of the 9 partial-thickness tears, respectively. The differences in performance of US and MRI were not statistically significant (p = 0.15). CONCLUSIONS: MRI following routine shoulder US was requested in only 5.2% of the patients. The additional value of MRI was in detecting intra-articular lesions. In patients who underwent surgery, US and MRI yielded comparably high sensitivity for detecting full-thickness RCT. US performed better in detecting partial-thickness tears, although the difference was not significant.

The presence of periosteum is essential for the healing of large diaphyseal segmental bone defects reconstructed with trabecular metal: a study in the femur of goats.

Large segmental diaphyseal bone defects can be reconstructed with massive structural allografts, but this technique is associated with high complication rates. Tantalum tabecular metal implants have been successfully used to restore bone defects associated with revision total knee or hip arthroplasties. The aim of this study was to investigate if tantalum cylinders could be used to reconstruct large load bearing segmental diaphyseal bone defects in the presence or absence of a periosteum coverage. Segmental bone defects were reconstructed with tantalum cylinders with or without preservation of the periosteum and stabilized by an intramedullary nail. Radiological analysis was performed postop and at 26 weeks follow-up. New bone was labeled with fluorochromes at 13 and 26 weeks follow-up. Reconstructions were tested mechanically and subsequently investigated histologically. Contra-lateral femurs were used as controls. Clinically all goats returned to normal functional loading after 2 weeks allowing unlimited weight bearing. Radiologically, all tantalum cylinders with periosteum coverage united with the host bone. Reconstructions with cylinders without periosteum coverage lead to radiological nonunion in five out of six cases. The strengths of the reconstruction with and without periosteum preservation were respectively 102.1% and 24.5% compared to controls. In the periosteum covered implants, bone contact was found at all levels of the tantalum cylinder and more and deeper bone ingrowth was found in this group. Tantalum cylinders seem a safe and reliable alternative for a massive cortical graft to reconstruct large diaphyseal bone defects in a goat model if healthy periosteum is present.

Sit-to-stand movement as a performance-based measure for patients with total knee arthroplasty.

BACKGROUND: Functional recovery of patients after a total knee arthroplasty (TKA) usually is measured with questionnaires. However, these self-report measures assess the patient's perspective on his or her ability to perform a task. Performance-based tests are needed to assess the patient's actual ability to perform a task. OBJECTIVE: The main purpose of this study was to quantify improvement in performance of the sit-to-stand movement of patients with a TKA. DESIGN AND METHODS: In this prospective study of 16 patients with end-stage knee osteoarthritis followed by a TKA, the maximal knee angular extension velocity and amount of unloading (shifting weight) of the affected leg during the sit-to-stand movement and the visual analog scale score for pain were assessed preoperatively and 6 months and 1 year postoperatively. These data were compared with data for a control group of individuals who were healthy (n=27). RESULTS: Before surgery, the participants in the TKA group unloaded their affected leg, but within 6 months after implantation, the affected leg was almost fully loaded again and comparable to the loading symmetry ratio of the control group. Furthermore, knee extension velocity also had increased, but remained lower than that of the control group. The changes in knee extension velocity took place during the first 6 months, after which a plateau was visible. Limitations A potential limitation of the study design was that the patients were not perfectly matched with the control subjects. CONCLUSIONS: Implantation of a total knee prosthesis partly improved performance of the sit-to-stand movement. Participants in the TKA group could fully load their operated leg, but they could not generate enough knee angular velocity during rising compared with the control group.

Acetabular revision with impacted morselized cancellous bone graft and a cemented cup in patients with rheumatoid arthritis. A concise follow-up, at eight to nineteen years, of a previous report.

We previously reported our results at a minimum of three years after thirty-five revisions of total hip arthroplasty acetabular components in twenty-eight patients with rheumatoid arthritis. The revisions were performed with use of impacted morselized bone graft and a cemented cup. This update report presents the results at eight to nineteen years after the surgery, which, to our knowledge, is the longest follow-up available in the literature. No patient was lost to follow-up. Since our previous report, there were two additional cup failures due to aseptic loosening, at ten and sixteen years postoperatively. Kaplan-Meier analysis showed the probability of survival of the acetabular component at twelve years to be 80% (95% confidence interval, 65% to 95%) with removal of the cup for any reason as the end point and 85% (95% confidence interval, 71% to 99%) with aseptic loosening as the end point. Cup revisions performed with cement and use of impaction bone-grafting in patients with rheumatoid arthritis led to acceptable long-term prosthetic survival rates. This technique is attractive from a biological standpoint because of the possibility of maintaining acetabular bone stock.

The stability of impacted morsellized bone grafts in a metal cage under dynamic loaded conditions: an in vitro reconstruction of a segmental diaphyseal bone defect.

INTRODUCTION: Reconstructions of segmental diaphyseal bone defects with massive allografts are related to complications like nonunion and fractures. A reconstruction of these defects with a cage filled with an impacted morsellized bone graft could be an alternative. The bone graft in these cages should ideally be loaded to prevent resorption. Loading of morsellized bone grafts however can cause instability. The goal of this study was to assess the stability of an impacted morsellized bone graft in a cage under dynamic loaded conditions in an in vitro reconstruction of a segmental diaphyseal bone defect. The second goal was to assess the influence of cage type, washing of the graft and bone-cage fit. MATERIALS AND METHODS: Two different cage types were filled with impacted morsellized bone graft. The grafts were used washed and unwashed and in variable bone-cage fit conditions. We recorded the bone graft deformation in the cage under dynamic loaded conditions. RESULTS: Stability appeared to be not very sensitive to the cage type and whether the bone chips were washed or not. However, quality of the fit of the cage with the bone segment was an important parameter and should be optimized during surgery. CONCLUSIONS: Morsellized impacted bone graft in a cage is stable in dynamic loaded conditions in an in vitro reconstruction of a segmental diaphyseal bone defect. We believe that this method of reconstruction is a promising alternative for the reconstruction of large diaphyseal bone defects and should be tested relative to its biological merits in animal experiments.

Is an impacted morselized graft in a cage an alternative for reconstructing segmental diaphyseal defects?

Large diaphyseal bone defects often are reconstructed with large structural allografts but these are prone to major complications. We therefore asked whether impacted morselized bone graft could be an alternative for a massive structural graft in reconstructing large diaphyseal bone defects. Defects in the femora of goats were reconstructed using a cage filled with firmly impacted morselized allograft or with a structural cortical autograft (n = 6 in both groups). All reconstructions were stabilized with an intramedullary nail. The goats were allowed full weightbearing. In all reconstructions, the grafts united radiographically. Mechanical torsion strength of the femur with the cage and structural cortical graft reconstructions were 66.6% and 60.3%, respectively, as compared with the contralateral femurs after 6 months. Histologically, the impacted morselized graft was replaced completely by new viable bone. In the structural graft group, a mixture of new and necrotic bone was present. Incorporation of the impacted graft into new viable bone suggests this type of reconstruction may be safer than reconstruction with a structural graft in which creeping substitution results in a mixture of viable and necrotic bone that can fracture. The data suggest that a cage filled with a loaded morselized graft could be an alternative for the massive cortical graft in reconstruction of large diaphyseal defects in an animal model.

Surgeon's expectations do not predict the outcome of a total knee arthroplasty.

INTRODUCTION: It is fascinating for both the patient and the surgeon to predict the outcome of a TKA at an early stage. Satisfaction after TKA is primarily determined by the preoperative expectations of the patient. The purpose of this study was to investigate if the peri-operative expectations of the surgeon predicted the outcome of a TKA. PATIENTS AND METHODS: A prospective study of 53 primary TKAs was performed. Preoperatively, the surgeon described the assessment of the difficulty of the TKA on a VAS. Immediately postoperative, the surgeon gave his satisfaction VAS about the procedure. After 1 year the surgeon's satisfaction VAS, the patient's satisfaction VAS and the KSCRS were determined. RESULTS: The Spearman's correlation coefficients between the preoperative difficulty assessment, the immediate postoperative satisfaction and the outcome measurements after 1 year were all very poor (-0.01 to 0.23). CONCLUSIONS: The outcome of a TKA depends on multiple factors. Both the surgeon's preoperative assessment of the difficulty and the surgeon's immediate postoperative satisfaction do not independently predict the outcome of a TKA.