Wenzel Waldstein

Sport and physical activity following unicompartmental knee arthroplasty: a systematic review

PurposeUnicompartmental knee arthroplasty (UKA) can be a surgical treatment option for patients with high expectations regarding the post-operative level of physical activity. A systematic review was undertaken to answer three research questions: (1) is there an improvement of physical activity based on validated activity scores following UKA? (2) What are the sport disciplines and the sport patterns of UKA patients? (3) What are the pre- and post-operative sport participation rates and the return to activity rates of UKA patients?MethodsFollowing the PRISMA guidelines, EMBASE, MEDLINE, ISI Web of Science and the Cochrane Central Register of Controlled Trials were searched for studies reporting the level of sport and/or physical activity before and after UKA, and/or included at least one activity score before and after UKA.ResultsSeventeen studies were identified reporting on 2972 UKAs, of which 89xa0% were medial UKAs and 92xa0% were mobile-bearing implants, respectively. Ten studies reported a statistically significant improvement of physical activity following UKA according to the UCLA activity score, the Tegner activity score or the High Activity Arthroplasty Score, respectively. Hiking, cycling and swimming are the most common activities following UKA. Sport participation before the onset of restricting symptoms ranged from 64 to 93xa0% and slightly decreased by 2–9xa0% following UKA. The return to activity rate ranged from 87 to 98xa0%.ConclusionPatients following UKA are physically active according to validated activity scores. A significant increase in low-impact activities and a decrease in high-impact activities after UKA was observed. Patients with a UKA regularly participate in sports; however, sport participation slightly decreased compared to pre-arthritic levels. This systematic review helps physicians to manage the expectations of patients regarding the level of physical activity following UKA.Level of evidenceIII.

OARSI osteoarthritis cartilage histopathology assessment system: A biomechanical evaluation in the human knee.

The study compared the OARSI osteoarthritis cartilage histopathology assessment system with the biomechanical quality of human in vivo cartilage samples. In a prospective cohort study, 84 patients (100 knees) with varus deformity of the knee were included between May, 2010 and January, 2012. Osteochondral samples underwent biomechanical and histologic analysis. The dynamic modulus significantly (pu2009<u20090.001) decreased with each advancing grade of degeneration from OARSI Grade 0 (surface intact) to OARSI Grade 4 (erosion). For the aggregate modulus, there were significant (pu2009<u20090.001) differences between OARSI Grade 0 and OARSI Grade 1 as well as between OARSI Grade 1 and OARSI Grade 2. From OARSI Grade 2 to OARSI Grade 5, no differences in aggregate modulus occurred. The new OARSI grading system provides useful information about the functional properties of cartilage. There is a significant difference in cartilage stiffness between samples with intact surface and no signs of degeneration (OARSI Grade 0) and samples with intact surface and early signs of arthritis (OARSI Grade 1). Surgeons performing joint preserving procedures have to be aware that in knees with an intact cartilage surface (OARSI Grade 0/1), significant differences in the biomechanical properties may exist.

YouTube provides irrelevant information for the diagnosis and treatment of hip arthritis

PurposeYouTube is increasingly becoming a key source for people to satisfy the need for additional information concerning their medical condition. This study analyses the completeness of accurate information found on YouTube pertaining to hip arthritis.MethodsThe present study analyzed 133 YouTube videos using the search terms: hip arthritis, hip arthritis symptoms, hip arthritis diagnosis, hip arthritis treatment and hip replacement. Two quality assessment checklists with a scale of 0 to 12 points were developed to evaluate available video content for the diagnosis and the treatment of hip arthritis. Videos were grouped into poor quality (grade 0–3), moderate quality (grade 4–7) and excellent quality (grade 8–12), respectively. Three independent observers assessed all videos using the new grading system and independently scored all videos. Discrepancies regarding the categories were clarified by consensus discussion. For intra-observer reliabilities, grading was performed at two occasions separated by fourxa0weeks.ResultsEighty-four percent (nu2009=u2009112) had a poor diagnostic information quality, 14% (nu2009=u200919) a moderate quality and only 2% (nu2009=u20092) an excellent quality, respectively. In 86% (nu2009=u2009114), videos provided poor treatment information quality. Eleven percent (nu2009=u200915) of videos had a moderate quality and only 3% (nu2009=u20094) an excellent quality, respectively.ConclusionsThe present study demonstrates that YouTube is a poor source for accurate information pertaining to the diagnosis and treatment of hip arthritis. These finding are of high relevance for clinicians as videos are going to become the primary source of information for patients. Therefore, high quality educational videos are needed to further guide patients on the way from the diagnosis of hip arthritis to its proper treatment.

Silver-coated megaprostheses: review of the literature

Periprosthetic infection remains one of the most serious complications following megaendoprostheses. Despite a large number of preventive measures that have been introduced in recent years, it has not been possible to further reduce the rate of periprosthetic infection. With regard to metallic modification of implants, silver in particular has been regarded as highly promising, since silver particles combine a high degree of antimicrobial activity with a low level of human toxicity. This review provides an overview of the history of the use of silver as an antimicrobial agent, its mechanism of action, and its clinical application in the field of megaendoprosthetics. The benefits of silver-coated prostheses could not be confirmed until now. However, a large number of retrospective studies suggest that the rate of periprosthetic infections could be reduced by using silver-coated megaprostheses.

Are lateral compartment osteophytes a predictor for lateral cartilage damage in varus osteoarthritic knees?: Data from the Osteoarthritis Initiative

We studied whether the presence of lateral osteophytes on plain radiographs was a predictor for the quality of cartilage in the lateral compartment of patients with varus osteoarthritic of the knee (Kellgren and Lawrence grade 2 to 3). The baseline MRIs of 344 patients from the Osteoarthritis Initiative (OAI) who had varus osteoarthritis (OA) of the knee on hip-knee-ankle radiographs were reviewed. Patients were categorised using the Osteoarthritis Research Society International (OARSI) osteophyte grading system into 174 patients with grade 0 (no osteophytes), 128 grade 1 (mild osteophytes), 28 grade 2 (moderate osteophytes) and 14 grade 3 (severe osteophytes) in the lateral compartment (tibia). All patients had Kellgren and Lawrence grade 2 or 3 arthritis of the medial compartment. The thickness and volume of the lateral cartilage and the percentage of full-thickness cartilage defects in the lateral compartment was analysed. There was no difference in the cartilage thickness or cartilage volume between knees with osteophyte grades 0 to 3. The percentage of full-thickness cartilage defects on the tibial side increased from < 2% for grade 0 and 1 to 10% for grade 3. The lateral compartment cartilage volume and thickness is not influenced by the presence of lateral compartment osteophytes in patients with varus OA of the knee. Large lateral compartment osteophytes (grade 3) increase the likelihood of full-thickness cartilage defects in the lateral compartment.

Topical Tranexamic Acid is Equivalent to Targeted Preoperative Autologous Blood Donation in Total Hip Arthroplasty

BACKGROUNDnTopical tranexamic acid (TXA) was introduced to replace the previous targeted preoperative autologous blood donation (PABD) program. This study aims to analyze the efficacy of topical TXA compared with targeted PABD in anemic patients undergoing primary total hip arthroplasty (THA).nnnMETHODSnTwo thousand two hundred fifty-one patients underwent primary THA between 2009 and 2013 using targeted autologous blood donation for 280 anemic patients (12%; Hb <12.5 g/dL). One thousand nine hundred seventy-one nonanemic patients (88%; ≥12.5 Hb/dL) received no blood management intervention. Starting in 2014, 505 consecutive patients were operated using 3 grams of topical TXA and abandoning PABD. Ninety-one patients (18%) were anemic and 414 (82%) nonanemic.nnnRESULTSnThe utilization of topical TXA in anemic patients resulted in higher hemoglobin levels on the first postoperative day (Pxa0= .014), but not on the second postoperative day (Pxa0= .198) compared with PABD. There was no difference in allogeneic transfusion rates between both groups: 12% vs 13% (Pxa0= .848). In the nonanemic group, TXA significantly increased hemoglobin levels on the first postoperative day (Pxa0= .001) as well as on the second postoperative day (P < .001), and resulted in a reduction in allogeneic transfusion rates from 8% to 1%.nnnCONCLUSIONnThe present study suggests that topical TXA is equivalent to PABD in anemic patients and reduces transfusion rates and increases Hb-levels in nonanemic patients.

The Accuracy of Acetabular Component Position Using a Novel Method to Determine Anteversion.

BACKGROUNDnThis study compares the differences in acetabular component position, leg length discrepancy, and hip offset between the anterior and posterior approach. A novel method is applied to determine the acetabular anteversion using the C-arm tilt angle for the anterior approach.nnnMETHODSnHundred consecutive anterior total hip arthroplasties were matched according to gender, body mass index, and age to a cohort of 100 primary total hip arthroplasties operated on through a posterior approach. Postoperative radiographs were analyzed to determine cup inclination, cup anteversion, leg length discrepancy, and hip offset.nnnRESULTSnThe mean inclination was 40.8° (range 33°-48°) and 45.1° (range 33°-55°) for the anterior and posterior approach, respectively. Using the new C-arm tilt plane technique, an average acetabular anteversion of 18.4° (range 11°-26°) was achieved with the anterior approach compared with 23.6° (range 8°-38°) with the posterior approach. Hundred percent cups in the anterior group and 81% in the posterior group fell within the safe zone (P < .001). There was no difference in the overall hip offset between the operated side and the contralateral side for the anterior (Pxa0= .074) and posterior (Pxa0= .919) group. There was no difference in leg length discrepancy between the 2 approaches (Pxa0=xa0.259).nnnCONCLUSIONnIntraoperative fluoroscopy-assisted direct anterior approach was associated with improved acetabular component positioning. However, no benefit was shown with regards to restoration of hip offset or leg length.

Lateral-compartment Osteophytes are not Associated With Lateral-compartment Cartilage Degeneration in Arthritic Varus Knees

BackgroundProgression of arthritis in the lateral compartment is one of the main failure modes of unicompartmental knee arthroplasty (UKA). The decision regarding whether to perform a medial UKA sometimes is made based on whether lateral-compartment osteophytes are visible on plain radiographs obtained before surgery, but it is not clear whether the presence of lateral-compartment osteophytes signifies that the cartilage in the lateral compartment is arthritic.Questions/purposes(1) Is the presence of lateral compartment osteophytes associated with biomechanical properties of lateral-compartment cartilage, and (2) are osteophytes in the lateral compartment associated with particular histologic features of cartilage in the lateral compartment?MethodsBetween May 2010 and January 2012, we performed 201 TKAs for varus osteoarthritis confirmed on standardized AP hip-to-ankle standing radiographs. All patients with a varus deformity were considered for this prospective study. During the enrollment period, 100 patients (101 knees) were not enrolled for this study because of declined consent or because they were unable to perform all required preoperative radiographic examinations. That left 84 patients (100 knees), of whom an additional 23 patients (27%) were excluded because either radiographic or biomechanical data were missing. For final analysis, 61 patients (71 knees) were available. There were 29 males (48%) and 32 females (52%) with a mean age of 65 years (range, 49–89 years). Their mean BMI was 26 kg/m2 (range, 17–47 kg/m2). Lateral-compartment osteophytes were graded by two observers on AP standing knee radiographs based on a template of the Osteoarthritis Research Society International (OARSI) radiographic atlas. During surgery, osteochondral plugs were harvested from the lateral tibial plateau and the distal lateral femur for biomechanical and histologic assessments. The intrinsic material coefficients aggregate modulus (Ha) and dynamic modulus (DM) were determined by applying a compressive load of 20 g for 1 hour. The histologic analysis was performed according to the qualitative osteoarthritis cartilage histopathology assessment system. The Mann-Whitney U test was performed to compare the distribution of variables. Power analysis was performed for the Mann-Whitney U test using an alpha of 0.05, a power of 80%, and a sample size of 71 resulting in a detectable effect size of 0.6. Owing to the limited sample size, only medium or large effects in changes of biomechanical properties can be excluded with adequate power.ResultsHa and DM were not different with the numbers available when comparing knees with osteophyte Grades 0, 1, and 2 on the lateral tibia. For Grade 3 tibial osteophytes (n = 3), the lateral tibia cartilage showed low Ha (0.39 MPa; SD, 0.17 MPa) and low DM (2.85 MPa; SD, 2.12 MPa). On the lateral femur, no differences of Ha and DM were observed with the numbers available between Grades 0 to 3 osteophytes. No differences with the numbers available in the OARSI histologic grades on the lateral tibia plateau and the distal lateral femur were observed between the different osteophyte grades.ConclusionsLateral-compartment osteophytes are not associated with biomechanically weaker cartilage or with more-advanced histologic signs of degeneration of lateral-compartment cartilage in knees with varus arthritis. Given the small sample size of 71, the study was underpowered to detect small-to-modest decreases in biomechanical properties. Future studies with larger sample sizes are needed to confirm the current findings.Clinical RelevanceFactors other than the presence or absence of lateral-compartment osteophytes should be considered when evaluating patients with medial-compartment arthritis for medial UKA. Future studies are required to define the limitations of plain radiographs to rule out cartilage degeneration in the lateral compartment of varus knees.

Salvage of a monoblock metal-on-metal cup using a dual mobility liner: a two-year MRI follow-up study

PurposeRevision of failed modular metal-on-metal total hip replacement (MoM-THA) can be technically difficult. A dual mobility liner can help to salvage a well-fixed acetabular component. The present paper reports the clinical and radiographic outcome of revision of failed Birmingham modular MoM-THA using a dual mobility liner.MethodsThe present study reports on ten patients (3 female and 7 male) with 11 revision THAs. Patients underwent revision an average of 51xa0months (range 40–73xa0months) after index procedure. Mean follow-up after the revision was 31xa0months (range 24–37xa0months) and all patients underwent an MRI with metal artifact reduction software (MARS) at least twoxa0years after revision to assess for local polyethylene wear and osteolysis.ResultsThe Harris Hip score improved from 92.2 (range 63.0–100.0) to 100.0 (pxa0=xa00.072). One patient had a one-time dislocation within sevenxa0days of surgery. No patient required additional surgeries. Radiographs showed no signs of component loosening and osteolysis and MRI imaging revealed no evidence of polyethylene wear or osteolysis.ConclusionA dual mobility liner in an existing Birmingham cup can provide excellent clinical and radiological short-term results without MRI evidence of increased polyethylene wear. Post-operative hip precautions should be enforced.

Varus knee osteoarthritis: Elevated synovial CD15 counts correlate with inferior biomechanical properties of lateral‐compartment cartilage

The study analyzed the influence of synovitis on the histological and biomechanical properties of lateral‐compartment cartilage. In a prospective cohort study, 84 patients (100 knees) with varus deformity of the knee were included. Osteochondral samples from the distal lateral femur underwent biomechanical and histologic analysis. Synovial tissue was sampled for histological (chronic synovitis score) and immunohistochemical evaluation of the degree of synovitis. CD15 (neutrophils), Ki‐67 (dividing cells), and CD68 (macrophages) were tested in all synovial samples. While the histological synovitis score did not correlate with the degree of cartilage degeneration (histological OARSI grades), both CD15 (rsu2009=u20090.297, pu2009=u20090.006) and Ki‐67 (rsu2009=u20090.249, pu2009=u20090.023) correlated with histological OARSI grades. There was a weak negative correlation of CD15 with biomechanical properties of cartilage of the distal lateral femur (aggregate modulus (Ha): rsu2009=u2009−0.125; pu2009=u20090.257; dynamic modulus (DM): rsu2009=u2009−0.216; pu2009=u20090.048). No correlations were observed for Ki‐67 and CD68. In addition, biomechanical properties were inferior in knees with a CD15 of >8/high power field compared to knees with a CD15 of ≤8/high power field (Ha: pu2009=u20090.031, du2009=u20090.46; DM: pu2009=u20090.005, du2009=u20090.68). The study demonstrates an association of increased inflammatory activity with advanced cartilage degeneration. Lateral‐compartment cartilage in knees with elevated synovial CD15 counts has a reduced ability to withstand compressive loads. CD15 might serve as an indicator for inferior biomechanical cartilage properties.