Efficacy of post-operative partial weight-bearing after total knee arthroplasty - a prospective observational trial.

PURPOSE: There is little evidence proving the concept of partial weight-bearing to be efficient and feasible. Using insole pressure measurement systems, this study aimed to explore the compliance to prescribed weight-bearing restrictions after total knee arthroplasty (TKA). METHODS: 50 patients after TKA were recruited in a prospective manner. They were advised to limit weight-bearing of the affected limb to 200 N. True load was measured via insole force-sensors on day one after surgery (M1) and before discharge (M2). Compliance to the rehabilitation protocol was the primary outcome parameter. RESULTS: At M1 and M2 compliance to the rehabilitation protocol was 0% und 2%, respectively. 84% (M1) and 90% (M2) of patients overloaded the affected limb during every step. The affected limb was loaded with 50% ± 14% (M1) and 57% ± 17% (M2) of body weight. Patients older than 65 loaded the affected limb on average 17% (M1) and 34% (M2) more than their younger counterparts did. This difference was even more pronounced when walking stairs up (49% increase on average) and down (53% increase on average). CONCLUSION: Surgeons must take into consideration that the ability to maintain partial weight-bearing after TKA is highly dependent on the age of the patient and the achievable load reduction is determined by the patient's body weight.

The AMADEUS score is not a sufficient predictor for functional outcome after autologous chondrocyte implantation (ACI) of the knee: data from the German Cartilage Registry (KnorpelRegister DGOU).

INTRODUCTION: The AMADEUS (Area Measurement And DEpth and Underlying Structures) score has advanced to a commonly used tool for MRI-based chondral defect severity grading prior to cartilage knee surgery. It was the intention of this study to assess the AMADEUS for a potential correlation with clinical data by patient-reported outcome measures (PROMs). METHODS: A total of 51 patients undergoing ACI (autologous chondrocyte implantation) between 2016 and 2022 were found eligible and retrospectively analyzed. All patients were registered in the German Cartilage Registry prior to surgery and follow-up data were collected using the Knee Osteoarthritis Outcome score (KOOS), the International Knee Documentation Committee (IKDC) Form and the numeric rating scale (NRS). Pre-operative MRI images were scored by three raters using the AMADEUS classification system, and an overall AMADEUS score was calculated which was subsequently correlated with pre- and post-operative PROMs. RESULTS: Mean patient age was 32.67 ± 8.37 years and mean defect size area 343.04 mm2 ± 139.45 mm2. No correlative capacity of the pre- and postoperative IKDC, KOOS or NRS scores was found with the AMADEUS final score or any of its subscores. From the pre- to postoperative visit, a significant improvement of the PROMs (IKDC: 45.53 ± 21.00 vs. 59.83 ± 17.93, p = 0.04; KOOS Pain: 58.00 ± 16.70 vs. 76.06 ± 19.20, p = 0.03; KOOS ADL: 64.17 ± 18.76 vs. 82.11 ± 16.68, p < 0.01; KOOS Sports: 26.11 ± 18.52 vs. 50.56 ± 23.94, p = 0.01; KOOS QOL: 25.50 ± 14.26 ± 45.28 ± 19.03, p = 0.00) was found. Intraclass correlation coefficients showed an overall good interrater agreement for the AMADEUS total score (ICC = 0.75). CONCLUSIONS: Study results suggest no correlative capacity of the AMADEUS with routinely used PROMs in patients undergoing ACI. Therefore, radiographically assessed cartilage defect characteristics poorly translate to pre- and postoperative patient-reported outcome data.

Functional Outcome after Direct Anterior Approach Total Hip Arthroplasty (DAA-THA) for Coxa Profunda and Protrusio Acetabuli-A Retrospective Study.

Objective: The direct anterior approach (DAA) is a recognized technique for total hip arthroplasty (THA) that spares soft tissue. Functional and clinical outcomes following THA via the DAA in patients with complex acetabular deformities, specifically coxa profunda (CP) and protrusio acetabuli (PA), have yet to be determined. Methods: A retrospective analysis was conducted on 188 primary THA cases, including 100 CP hips and 88 PA hips, performed via the DAA. Functional and clinical outcomes were evaluated by means of the Western Ontario and McMaster Universities Arthritis Index (WOMAC) and Harris Hip Score (HHS) preoperatively and at a mean follow-up of 46 ± 14 months. Furthermore, potential complications were assessed. Results: From the preoperative to the latest postoperative visit, a significant improvement in the WOMAC total score was observed (CP: -34.89 ± 20.66; PA: -40.38 ± 21.11). The length of stay (LOS) was the only parameter predictive of the postoperative WOMAC total score, with each day of LOS increasing the postoperative WOMAC by a mean of 1.77 points (p < 0.01). The HHS improved by 38.37 ± 14.23 (PA-group) and 32.79 ± 14.89 points (CP-group). No significant difference in the patient-reported outcome measures (PROMs) between the CP- and PA-group was found. The survival rate for any revision was 97.70% (PA-group) and 92.80% (CP-group). Conclusion: The results of this study indicate that the minimally invasive DAA was not predictive of the functional and clinical outcome following DAA-THA in patients with CP and PA. Improvements in the mean WOMAC and HHS scores were above or within the reported MCID. Additionally, revision rates were well below those reported in the literature for short and intermediate follow-up periods.

Vitamin D Deficiency Is Frequent in Patients with Rapidly Destructive Osteoarthritis-Data from a Single-Center Analysis.

BACKGROUND: Rapidly destructive osteoarthritis (RDO) of the hip joint is characterised by the rapid destruction of the femoral head with or without acetabular involvement. There has been increasing interest in this disease over the past years; however, the entity is still poorly understood, and its pathophysiology remains unknown. Yet, there is ample evidence today that increased bone metabolism might play a role in the onset and progression of the disease. Vitamin D is of utmost importance to maintain a balanced bone metabolism. However, whether vitamin D deficiency is involved in disease development remains to be elucidated. Further, the vitamin D status of patients with RDO has not yet been analysed. For this reason, the objective of this study was to assess the vitamin D status of patients with RDO. Moreover, the aim was to clarify whether there is a difference in the vitamin D status of patients with RDO compared with patients with primary osteoarthritis (OA). METHODS: In this single-centre analysis, the 25(OH)D, PTH, and calcium levels of 29 patients who presented with RDO between 2020 and 2022 were assessed. RESULTS: Altogether, 97% of patients (28/29) were vitamin D deficient, a further 3% (1/29) were vitamin D insufficient, and not a single patient presented with a sufficient vitamin D status. Notably, the vitamin D levels of RDO patients (mean = 11.04 ng/mL) were significantly lower than the vitamin D levels of patients with OA (mean = 22.16 ng/mL, p = 0.001). CONCLUSION: In conclusion, we found a widespread and high rate of vitamin D deficiency in patients with RDO. Hence, we believe that 25(OH)D status should routinely be analysed in these patients.

Does Body Mass Index (BMI) Affect the Reconstruction of Biomechanical Parameters in Patients Undergoing Total Hip Replacement (THR) through the Direct Anterior Approach (DAA)?

OBJECTIVE: Direct anterior approach total hip replacement (DAA-THR) is gaining increased interest due to its tissue-sparing nature and rapid recovery. Obesity has been shown to be a significant parameter influencing cup positioning in DAA-THR. It was the intention of this retrospective study to examine how obesity would influence the restoration of native hip biomechanical parameters during DAA-THR. MATERIALS AND METHODS: A total of 74 patients from a high-volume university orthopedic center after unilateral DAA-THA were included. Patients were retrospectively allocated to a study group (BMI > 30 kg/m2) and a control group (BMI < 30 kg/m2). Furthermore, propensity-score matching for baseline parameters was performed, leaving 30 patients in each group. Biomechanical parameters of the hip (i.e., femoral offset (FO), abductor lever arm (ABL), acetabular offset (AO), center of rotation (COR), stem alignment (SA), body weight lever arm (BWL), cup inclination (CI), and leg length discrepancy (LLD) were evaluated on standardized plain radiographs, and parameters were compared to the native contralateral hip. RESULTS: Mean BMI in the study group was 35.07 ± 5.13 kg/m2 and 25.43 ± 2.64 kg/m2 in the control group. There was a significant decrease of the ABL only in the study cohort (p = 0.01). CI and SA did not differ between both cohorts. FO was slightly increased compared to the native hip in both groups. There was a marginally higher but non-significant proportion of improper FO restoration in the study group (19 vs. 16 patients, p = 0.60). CONCLUSIONS: Obesity, as quantified by BMI, only has a limited impact on the adequate reconstruction of native biomechanical parameters of the hip during DAA-THR. ABL was the only parameter to be significantly decreased in the overweight patients after DAA-THR. Therefore, special care should be taken on proper acetabular reaming and consequent seating of the cup in the obese patient to avoid excessive lateral positioning.

Conversion total hip arthroplasty following proximal femur fracture: A retrospective analysis.

BACKGROUND: The incidence of conversion total hip arthroplasty (cTHA) following reduction and fixation for proximal femur fractures will increase in parallel to the aging population worldwide. OBJECTIVE: The goal of this study is to report the frequency of bacterial detection and the outcome of cTHA at the authors' institution and to analyze preoperative factors that correlate with higher rates of bacterial growth and septic revision. METHODS: 48 patients who had been converted to THA after osteosynthesis of a proximal femur fracture either by a one- or two-stage procedure were included. Septic failure rate and the frequency of bacterial detection at the time of fixation device removal were calculated. The influence of different preoperative factors was examined by the odds ratio. A receiver operating characteristic curve of c-reactive protein (CRP) for detection of bacterial growth at the time of fixation device removal was calculated. RESULTS: 18.8% patients showed positive bacterial cultures, with Staph. epidermidis being the most frequent pathogen (33.3%). Septic failure after cTHA occurred in 4.2%. Fixation with cephalomedullary nails and complications with the internal fixation showed higher odds for bacterial growth at time of cTHA. CRP for predicting bacterial growth had an area under the curve of 0.661. Implant survival was worse when temporary spacers were used. CONCLUSION: Bacterial detection rate at the time of cTHA is high, whereas septic failure rates are low. Isolated evaluation of inflammatory blood markers without other diagnostic modalities for infection is not decisive and does not justify a two-stage approach with implantation of a temporary spacer.

The AMADEUS score is not a sufficient predictor for functional outcome after high tibial osteotomy.

PURPOSE: The Area Measurement And Depth Underlying Structures (AMADEUS) classification system has been proposed as a valuable tool for magnetic resonance (MR)-based grading of preoperatively encountered chondral defects of the knee joint. However, the potential relationship of this novel score with clinical data was yet to determine. It was the primary intention of this study to assess the correlative relationship of the AMADEUS with patient reported outcome scores in patients undergoing medial open-wedge high tibial valgus osteotomy (HTO). Furthermore, the arthroscopic ICRS (International Cartilage Repair Society) grade evaluation was tested for correlation with the AMADEUS classification system. METHODS: This retrospective, monocentric study found a total of 70 individuals that were indicated for HTO due to degenerative chondral defects of the medial compartment between 2008 and 2019. A preoperative MR image as well as a pre-osteotomy diagnostic arthroscopy for ICRS grade evaluation was mandatory for all patients. The Knee Osteoarthritis Outcome Score (KOOS) including its five subscale scores (KOOS-ADL, KOOS-QOL, KOOS-Sports, KOOS-Pain, KOOS-Symptoms) was obtained preoperatively and at a mean follow-up of 41.2 ± 26.3 months. Preoperative chondral defects were evaluated using the AMADEUS classification system and the final AMADEUS scores were correlated with the pre- and postoperative KOOS subscale sores. Furthermore, arthroscopic ICRS defect severity was correlated with the AMADEUS classification system. RESULTS: There was a statistically significant correlation between the AMADEUS BME (bone marrow edema) subscore and the KOOS Symptoms subscore at the preoperative visit (r = 0.25, p = 0.04). No statistically significant monotonic association between the AMADEUS total score and the AMADEUS grade with pre- and postoperative KOOS subscale scores were found. Intraoperatively obtained ICRS grade did reveal a moderate correlative relation with the AMADEUS total score and the AMADEUS grade (r = 0.28, p = 0.02). CONCLUSIONS: The novel AMADEUS classification system largely lacks correlative capacity with patient reported outcome measures in patients undergoing HTO. The MR tomographic appearance of bone marrow edema is the only parameter predictive of the clinical outcome at the preoperative visit.

The Direct Anterior Approach (DAA) as a Standard Approach for Total Hip Arthroplasty (THA) in Coxa Profunda and Protrusio Acetabuli? A Radiographic Analysis of 188 Cases.

INTRODUCTION: The direct anterior approach (DAA) represents a well-recognized soft tissue sparing technique for primary total hip arthroplasty (THA). The feasibility and suitability of the DAA in cases of complex acetabular deformities, namely coxa profunda (CP) and protrusio acetabuli (PA), remain to be determined. METHODS: A total of 188 cases of CP (100 cases) and PA (88 cases) hips undergoing primary THA via the DAA were retrospectively analyzed. Surgical and radiographic parameters were evaluated and potential complications were assessed. Finally, successful implantation was defined if surgical and radiographic parameters were well within established values of non-complex primary THA. RESULTS: In 159 hips, the medial border of the acetabular component was transferred laterally to the ilioischial line, corresponding to a fully treated acetabular protrusion. In 23 (12.23%) cases, mild, and in 5 (2.66%) cases, moderate residual acetabular protrusion remained after THA. Postoperatively, 11.40% (PA group) and 9.00% (CP group) had a leg length discrepancy (LLD) greater than 10 mm. The mean operative time was significantly less than 60 min. A linear relationship between the BMI and operative time was observed, with an additional 0.9 min of operative time per BMI unit. Overall, complications were rare and did not differ between the two groups. CONCLUSION: The results of this study suggest that the DAA is a suitable approach for primary THA in patients with coxa profunda and acetabular protrusion if performed by experienced surgeons familiar with the DAA. Obese patients with acetabular protrusion may pose a significant limitation to the DAA and caution should be advised in cases of obesity.

Accuracy of Positioning and Risk Factors for Malpositioning Custom-Made Femoral Stems in Total Hip Arthroplasty-A Retrospective Multicenter Analysis.

Total hip arthroplasty (THA) is commonly performed using off-the-shelf implants. In the case of a severe mismatch between the anatomy of the proximal femur and the geometry of the stem, the use of custom-made stems might become necessary. The goal of this study was to investigate the precision of the implantation of custom-made stems of one manufacturer (CTX stem, AQ Implants) and to determine risk factors for malpositioning. All patients receiving a custom-made CTX stem between 2014 and 2020 at six high-volume academic centers were retrospectively recruited. The achieved position of the stem, as determined by stem version, stem coronal angle, and implantation depth on radiographs, was compared to the plan. The influence of radiographic and demographic parameters on the position was investigated. The results revealed a high variability of the achieved implant position in relation to the preoperative plan. While the stem coronal angle only differed slightly from the intended position, the stem version and the implantation depth showed a high frequency and amount of deviation. Right stems showed significantly higher positions than planned. Surgeons must be aware of this potential problem when implanting custom-made stems.

Total hip arthroplasty in geriatric patients - a single-center experience.

BACKGROUND: As advanced age often leads to accumulating comorbidities, geriatric patients are endangered by serious events during total hip arthroplasty. This study was conducted to explore whether or not the benefit in terms of health-related quality of life (HRQoL) was comparable to younger patients. METHODS: At a single academic center, 100 patients meeting the following inclusion criteria were retrospectively recruited: (1) primary arthritis of the hip leading to THA; (2) age 80 years or older at the time of surgery; (3) follow up of at least 12 months. For comparison, two further groups were recruited in the same manner, differing only in the age criterion: 100 patients aged 60-69 and 100 patients aged 70-79 at the time of hip replacement. The primary outcome was compared using the WOMAC and the EQ-5D score. The secondary outcome was determined by rates of orthopedic and non-orthopedic complications. Intragroup comparisons of the PROMS were performed by the non-parametric Wilcoxon test for paired samples. For intergroup comparisons of the PROMS, the Kruskal-Wallis-test was performed. Concerning categorial data, intergroup comparisons were performed by the Chi-Square test. The level of significance was set at 0.05. RESULTS: Concerning the WOMAC score, neither the absolute values at 12 months after THA (p = 0.176) nor the amount of change relative to the values before surgery (p = 0.308) differed significantly between the 3 groups. Concerning the EQ-5D index the absolute values at 12 months after THA differed significantly (p = 0.008). Rates of orthopedic complications did not differ significantly (p = 0.631). Rates of non-orthopedic complications increased significantly with rising age (p = 0.033). CONCLUSIONS: Compared to younger patients, geriatric patients after THA have an equal improvement in hip-specific and general HRQoL. While rates of orthopedic complications are comparable too, non-orthopedic complications occur more frequently.

Total Hip Arthroplasty After Spinal Fusion Surgery. / Hüftendoprothetik nach Wirbelsäulenfusion.

Given the close functional connection between the hip and the spine, their simultaneous degenerative pathology is a common problem seen in orthopedic patients and has been termed the "hip spine syndrome". Demographic change and an increasing number of operations have led to more patients who have undergone both total hip arthroplasty and spondylodesis especially of the lumbar spine. Studies have shown significant dislocation rates in this cohort of as high as almost 30%. Biomechanical studies and considerations show that spinal surgery directly influences the functional acetabular position and, consequently, the position of the acetabular cup, making the correct implantation challenging for the hip surgeon. Spinal fusion affects not only the biomechanics of the spine but also of the hip joint and, for that reason, must accordingly be taken into account when planning total hip arthroplasty.