Zirconium as a Promising Synovial Biomarker for Loose Cemented Knee Prosthesis.

BACKGROUND: Aseptic loosening is the most common mode of failure after total knee arthroplasty. Despite this, the diagnosis often remains challenging and mainly relies on imaging modalities. Until today, no biomarker exists to aid in diagnosing loosening of the implants. As zirconium (Zr) is often found in bone cement, where it serves as radiopacifier, this study aimed to establish Zr as a synovial biomarker for loosened cemented knee prostheses. METHODS: A total of 31 patients scheduled for revision of a cemented knee prostheses were included. In all patients, the initial used cement contained Zr. After arthrotomy, specimens of synovial fluid were taken and levels of Zr were measured by inductively coupled plasma mass spectrometry. Depending on the necessary amount of force for explantation, the implants were graded "loose" or "well-fixed". Preoperative radiographs were evaluated by 2 independent physicians. RESULTS: The concentration of Zr in the synovial fluid differed significantly (P < .001) between the "loose" (mean 170.9 µg/L, range 0 to 1941 µg/L) and the "well-fixed" (mean 0.6 µg/L, range 0 to 6 µg/L) implants. The receiver operating characteristic analysis revealed 0.25 µg/l as an optimal cutoff value leading to a sensitivity of 0.84, a specificity of 0.92, a positive predictive value of 0.94, and a negative predictive value of 0.79. There was no significant difference in the diagnostic performance compared to radiographs (P = .66). CONCLUSIONS: Zirconium proved to be a reliable novel synovial biomarker for diagnosing aseptic loosening of knee prothesis fixed with cement containing Zr. This biomarker should not be interpreted in isolation, but in combination with existing diagnostic tools.

Vitamin D Receptor Expression Is Significantly Decreased in Bone Metastases Compared to Matched Primary Breast Cancer Tumours.

There is ample evidence today that vitamin D signalling via the vitamin D receptor (VDR) plays a pivotal role in cancer growth and metastasis. The aim of this study was to analyse VDR expression of primary breast cancer and corresponding bone metastases tissue samples. Collectively, 15 sample pairs and 11 samples of patients that did not develop metastases were analysed histologically for VDR expression (n = 41). Overall, VDR expression was significantly lower in bone metastases compared to primary tumour samples (p < .0001). Downregulation of the VDR in breast cancer cells may define a critical turning point in oncogenesis that accelerates cancer cell dissemination and metastases.

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.

Epidemiology and Trends in Cartilage Surgery of the Foot and Ankle in Germany: An Analysis of National Healthcare Billing and Reporting Data from 2006 to 2020.

Background and objectives: Cartilage surgery constitutes a standard intervention in foot and ankle procedures. Currently, there is a lack of epidemiological data on its frequency, age distribution, and surgical options for cartilage surgery. This study aimed to investigate the current landscape of cartilage surgery in Germany and identify the most common procedures from an epidemiological standpoint. Materials and methods: Medical billing and reporting data from the Federal Statistical Office of Germany, encompassing the period 2006-2020, was examined, including all foot and ankle cartilage surgical procedures (summarized under OPS codes 5-812 and 5-801). The dataset incorporated information on the affected joint, patient age and sex, and surgery type. Each surgical procedure was categorized as "debridement", "regeneration" or "refixation". Linear and nonlinear regression analyses were employed, with a statistical significance threshold of 0.05. Results: From the total of 136,501 procedures conducted during the study period, the most frequently performed interventions were microfracture (58,252) and chondroplasty (56,135), and thus, debridement procedures were in the leading position. The use of acellular membranes was the most used regenerative technique (n = 11,414). At the ankle joint, interventions were mostly arthroscopic and in men, while foot cartilage surgeries were preferably performed via open surgery and mostly in women. Age distribution analysis revealed two primary peaks: the first in the 20-25-year-old group (ankle and foot) and the second in the 45-50-year-old group (ankle) and 55-60-year-old group (foot). Refixation and regenerative procedures were more frequent among younger individuals, while debriding procedures were more frequent among older individuals. Regenerative procedures, particularly in the ankle, significantly increased over time. Conclusions: Cartilage surgery of the foot and ankle was common, with two primary age groups predominantly affected. Notably, recent years have witnessed a considerable rise in cartilage regenerative procedures.

The projected volume of primary and revision total knee arthroplasty will place an immense burden on future health care systems over the next 30 years.

PURPOSE: Total knee arthroplasty (TKA) rates have increased substantially in the recent decades worldwide, with Germany being one of the leading countries in the prevalence of TKA. The aim of this study was to provide an overview of treatment changes during the last decade and to project the expected burden of primary and revision TKA (rTKA) for the next 30 years. METHODS: Comprehensive nationwide data from Germany was used to quantify primary and revision TKA rates as a function of age and gender. Projections were performed with use of a Poisson regression models and a combination of exponential smoothing and autoregressive integrated moving average models on historical procedure rates in relation to official population projections from 2020 to 2050. RESULTS: The incidence rate of primary TKAs is projected to increase by around 43% to 299 per 100,000 inhabitants [95% CI 231-368], leading to a projected total number of 225,957 primary TKAs in 2050 (95% CI 178,804-276,442). This increase has been related to a growing number of TKA performed in male patients, with the highest increase modelled in patients between 50 and 65 years of age. At the same time, the annual total number of revision procedures is forecast to increase even more rapidly by almost 90%, accounting for 47,313 (95% CI 15,741-78,885; IR = 62.7 per 100,000, 95% CI 20.8-104.5) procedures by 2050. Those numbers are primarily associated with a rising number of rTKAs secondary to periprosthetic joint infection (PJI). CONCLUSIONS: Using this country- specific forecast approach, a rising number of primary TKA and an even more rapidly growing number of rTKA, especially for PJI, has been projected until 2050, which will inevitably provide a huge challenge for the future health care system. As many other industrialized nations will face similar demographic and procedure-specific developments, these forecasts should be alarming for many health care systems worldwide and emphasize the tremendous need for an appropriate financial and human resource management in the future. LEVEL OF EVIDENCE: Level III, prognostic study, economic and decision analysis.

Effect of Mobilization on the Day of Surgery After Total Hip Arthroplasty in Elderly, Obese, and Severely Diseased Patients.

BACKGROUND: Mobilization on the day of surgery after total hip arthroplasty (THA) is widely used. However, elderly, obese and severely diseased patients are often excluded from early mobilization. Therefore, it was our aim to investigate the effect of mobilization on the day of surgery with focus on these patients. METHODS: 167 patients underwent THA via direct anterior approach. Exclusion criterion was the use of wound drainage. The patients were randomly allocated to two groups. Day 0 group was mobilized 4 hours after surgery, day 1 group the day after surgery. Primary outcome was the time to readiness for discharge (TRD). Secondary outcome was the occurrence of adverse events (vertigo, nausea, vomiting, severe pain) on the day of surgery. Group comparisons were calculated with respect to elderly (age ≥75 years), obese (BMI ≥30 kg/m2) and severely diseased patients (ASA≥3). RESULTS: TRD was shorter in day 0 group (3.25 vs 3.99 days, P < .01). The rate of adverse events on the day of surgery was similar in both groups (0.28 vs 0.25, P = .73). TRD differences were higher within all subgroups (3.85vs4.81; 3.25vs4.39; 4.08vs5.11days) while the rate of immediate adverse events was reduced (0.15vs0.24; 0.25vs0.3; 0.25vs0.33). Within 90 days 3 patients of group 0 underwent revision surgery, none of group 1 (P = .12). CONCLUSION: Mobilization on the day of surgery reduces the TRD without increasing the rate of immediate adverse events, regardless of age, BMI and ASA score. Future studies are needed to investigate if early mobility increases the 90-days complication rate.

Why compromise the patella? Five-year follow-up results of medial patellofemoral ligament reconstruction with soft tissue patellar fixation.

PURPOSE: This study investigates the redislocation rate and functional outcome at a minimum follow-up of five years after medial patellofemoral ligament (MPFL) reconstruction with soft tissue patellar fixation for patella instability. METHODS: Patients were retrospectively identified and knees were evaluated for trochlea dysplasia according to Dejour, for presence of patella alta and for presence of cartilage lesion at surgery. At a minimum follow-up of five years, information about an incident of redislocation was obtained. Kujala, Lysholm, and Tegner questionnaires as well as range of motion were used to measure functional outcome. RESULTS: Eighty-nine knees were included. Follow-up rate for redislocation was 79.8% and for functional outcome 58.4%. After a mean follow-up of 5.8 years, the redislocation rate was 5.6%. There was significant improvement of the Kujala score (68.8 to 88.2, p = 0.000) and of the Lysholm score (71.3 to 88.4, p = 0.000). Range of motion at follow-up was 149.0° (115-165). 77.5% of the knees had patella alta and 52.9% trochlear dysplasia types B, C, or D. Patellar cartilage legions were present in 54.2%. Redislocations occurred in knees with trochlear dysplasia type C in combination with patella alta. CONCLUSION: MPFL reconstruction with soft tissue patellar fixation leads to significant improvement of knee function and low midterm redislocation rate. Patients with high-grade trochlear dysplasia should be considered for additional osseous correction.

No functional differences in anatomic reconstruction with one vs. two suture anchors after non-simultaneous bilateral distal biceps brachii tendon rupture: a case report and review of the literature.

BACKGROUND: Surgical reattachment of the tendon is still the gold standard for ruptures of the distal biceps brachii tendon. Several fixation techniques have been described in the literature, with suture anchors being one of the most common fixation techniques. Currently, there is no data available on how many anchors are required for a safe and stable refixation. In this case report clinical data of a patient with non-simultaneous bilateral distal biceps tendon ruptures treated with a different number of suture anchors for each side (one vs. two) are demonstrated. CASE PRESENTATION: A 47-year-old factory worker suffered a rupture of the distal biceps tendon on both arms following two different occasions. The left side was fixed using a single suture anchor, while refixation on the right side was performed with two anchors. The patient was prospectively followed for one year. Functional outcome was assessed using the Andrews Carson Score (ACS), the Oxford Elbow Score (OES), and the Disabilities of Arm, Shoulder and Hand (DASH) Score after six, twelve, 24 and 48 weeks. Furthermore, an isokinetic strength measurement for flexion strength was performed after 24 and 48 weeks. After 48 weeks the patient presented with excellent functional outcome scores and no follow-up complications. During the follow-up period, no differences in the functional scores nor in the isokinetic flexion strength measurement could be detected. Furthermore, no radiological complications (like heterotopic ossifications) could be detected in the postoperative radiographs after one year. CONCLUSIONS: Anatomic reattachment of the distal biceps tendon is a successful operative treatment option for distal biceps tendon ruptures. Suture anchor fixation remains one of the most common techniques, as it allows fast surgery and provides good results with respect to range of motion (ROM) and functional scoring according to the current literature. However, the number of anchors required for a stable fixation remains unclear. As indicated by our presented case, we hypothesize, that there are no significant differences between a one-point or a two-point fixation. In the presented case report, no intraindividual differences between the usage of one versus two suture anchors were evident in the short-term follow-up.

The human arthritic hip joint is a source of mesenchymal stromal cells (MSCs) with extensive multipotent differentiation potential.

BACKGROUND: While multiple in vitro studies examined mesenchymal stromal cells (MSCs) derived from bone marrow or hyaline cartilage, there is little to no data about the presence of MSCs in the joint capsule or the ligamentum capitis femoris (LCF) of the hip joint. Therefore, this in vitro study examined the presence and differentiation potential of MSCs isolated from the bone marrow, arthritic hyaline cartilage, the LCF and full-thickness samples of the anterior joint capsule of the hip joint. METHODS: MSCs were isolated and multiplied in adherent monolayer cell cultures. Osteogenesis and adipogenesis were induced in monolayer cell cultures for 21 days using a differentiation medium containing specific growth factors, while chondrogenesis in the presence of TGF-ß1 was performed using pellet-culture for 27 days. Control cultures were maintained for comparison over the same duration of time. The differentiation process was analyzed using histological and immunohistochemical stainings as well as semiquantitative RT-PCR for measuring the mean expression levels of tissue-specific genes. RESULTS: This in vitro research showed that the isolated cells from all four donor tissues grew plastic-adherent and showed similar adipogenic and osteogenic differentiation capacity as proven by the histological detection of lipid droplets or deposits of extracellular calcium and collagen type I. After 27 days of chondrogenesis proteoglycans accumulated in the differentiated MSC-pellets from all donor tissues. Immunohistochemical staining revealed vast amounts of collagen type II in all differentiated MSC-pellets, except for those from the LCF. Interestingly, all differentiated MSCs still showed a clear increase in mean expression of adipogenic, osteogenic and chondrogenic marker genes. In addition, the examination of an exemplary selected donor sample revealed that cells from all four donor tissues were clearly positive for the surface markers CD44, CD73, CD90 and CD105 by flow cytometric analysis. CONCLUSIONS: This study proved the presence of MSC-like cells in all four examined donor tissues of the hip joint. No significant differences were observed during osteogenic or adipogenic differentiation depending on the source of MSCs used. Further research is necessary to fully determine the tripotent differentiation potential of cells isolated from the LCF and capsule tissue of the hip joint.

Is debridement beneficial for focal cartilage defects of the knee: data from the German Cartilage Registry (KnorpelRegister DGOU).

INTRODUCTION: Focal cartilage defects of the knee are often treated with arthroscopic debridement. Existing literature discussing the benefit of debridement for small articular cartilage lesions is scarce, especially if the debridement was not part of a combined operative cartilage procedure including meniscal and ligament repair. The purpose of this study was to examine the patients´ benefit after arthroscopic debridement for the treatment of isolated focal chondral defects with or without partial meniscus resection. MATERIALS AND METHODS: Baseline (preoperative data) and 12-month follow-up of the five Knee Osteoarthritis Outcome Score (KOOS) subscores and the Numeric Rating Scale (NRS) for pain were analyzed in 126 patients undergoing debridement for focal chondral defects of the knee from the German Cartilage Registry. Sub-analysis for patients receiving isolated debridement and debridement with concomitant partial resection of meniscal pathologies was performed. Thus, four subgroups were created according to the treated defect size and presence of meniscal pathologies: "debridement-only < 2 cm2", "debridement-only > 2 cm2", "debridement and partial meniscus resection < 2 cm2" and "debridement and partial meniscus resection > 2 cm2". RESULTS: KOOS-subscores showed a significant increase from baseline to follow-up evaluation (p = 0.017-0.037) within the 126 patients. Sub-analysis showed significant improvement of all five KOOS-subscores in all three subgroups, except for the "debridement and partial meniscus resection > 2 cm2"-group: in this group the KOOS subscores symptoms and sports showed no significant improvement. The NRS scores revealed no significant changes from baseline to 12-month follow-up within the four subgroups. CONCLUSION: An overall benefit of arthroscopic debridement for focal cartilage lesions of the knee could be conducted. Isolated cartilage defects seem to benefit from debridement irrespectively of size. In patients with large cartilage defects (> 2 cm2) and concurrent meniscal pathology expectation to improvement should be humbled. Effective reduction of pain by arthroscopic debridement remains unclear.

[Virtual arthroscopy : Gaming or training concept of the future]. / Virtuelle Arthroskopie : Computerspiel oder Weiterbildungskonzept der Zukunft?

Arthroscopy is a technically challenging surgical procedure with a relatively shallow learning curve compared to open procedures. To become an expert special cognitive and manual abilities have to be acquired and trained. The current situation in further medical education combined with the increasing economic pressure in the medical field does not leave enough room for a time-consuming training in arthroscopic techniques. A structured simulation training could be an alternative solution to this problem. The benefits of arthroscopic simulation training are meanwhile well documented. The complex tasks that an expert carries out during arthroscopy can be fragmented into more simple and elementary exercises and can be trained in a stress-free environment outside the operation room. An essential advantage of simulation training is the assessment of objective measurement parameters during the individual exercises. These parameters can be used to evaluate the learning process and performance of arthroscopic tasks. The aim of this review is to reflect the current state of simulation technology in arthroscopy and to show how simulator training can be meaningfully and effectively integrated into arthroscopic further training, exemplified by a modern medical further education concept.

[Acute and chronic instability of the elbow joint]. / Akute und chronische Instabilitäten des Ellenbogengelenkes.

Elbow dislocations are frequent and present with a broad spectrum of subsequent ligamentous and soft tissue injuries. Beside clinical examination, fluoroscopy, ultrasound and magnetic resonance imaging (MRI) can specify the extent of the injuries and provide a foundation for decision-making between conservative and operative treatment. This article highlights the basic underlying biomechanics and anatomy, discusses the trauma mechanisms and presents clinical and imaging diagnostic procedures. Treatment algorithms for conservative and surgical treatment are presented in detail. In addition to acute instability, chronic instability of the elbow has recently been recognized as the cause of a large variety of symptoms, often resulting in significant functional impairment. The most commonly used techniques for reconstruction of the medial and lateral collateral ligaments and the rehabilitation protocols are described in detail.

Epidemiological Analysis of Traumatic Compartment Syndromes in Germany.

Background: Traumatic compartment syndrome is a critical condition that can lead to severe, lifelong disability. Methods: This retrospective study analyzed hospital billing data from 2015 to 2022, provided by the Federal Statistical Office of Germany, to examine the demographics and trends of traumatic compartment syndrome in Germany. The analysis included cases coded with ICD-10 codes T79.60 to T79.69 and any therapeutic OPS code starting with 5-79, focusing on diagnosis year, gender, ICD-10 code, and patient age. Results: The results showed that out of 13,305 cases, the majority were in the lower leg (44.4%), with males having a significantly higher incidence than females (2.3:1 ratio). A bimodal age distribution was observed, with peaks at 22-23 and 55 years. A notable annual decline of 43.87 cases in compartment syndrome was observed, with significant decreases across different genders and age groups, particularly in males under 40 (23.68 cases per year) and in the "foot" and "lower leg" categories (16.67 and 32.87 cases per year, respectively). Conclusions: The study highlights a declining trend in traumatic CS cases in Germany, with distinct demographic patterns. Through these findings, hospitals can adjust their therapeutic regimens, and it could increase awareness among healthcare professionals about this disease.

Prevalence and Risk Factors of Vitamin D Deficiency in Patients Scheduled to Undergo Revision Arthroplasty of the Hip, Knee and Shoulder-Data from a Single-Centre Analysis.

Vitamin D is crucial for ideal bone health and good muscle function, both essential requirements for successful joint arthroplasty. Hence, vitamin D deficiency has recently been identified as a predictor of poorer outcomes in patients scheduled to undergo total joint arthroplasty (TJA). Moreover, there is ample evidence today that vitamin D deficiency is associated with periprosthetic joint infection. Yet, vitamin D deficiency seems to be frequent in patients who are scheduled to undergo TJA. However, the prevalence of hypovitaminosis D in patients who require revision arthroplasty (rTJA) is largely unknown. Further, risk factors of vitamin D deficiency in these patients remain to be elucidated. For this reason, the primary objective of this study was to assess the vitamin D status of patients scheduled to undergo rTJA of the hip, knee and shoulder. The secondary objective was to identify potential risk factors for hypovitaminosis D in these patients. Serum vitamin D [25(OH)D] levels of 249 patients who were scheduled for rTJA were assessed over a period of twelve months at a high-volume TJA centre. Collectively, 23% of patients reported a routine intake of vitamin D supplements (58/249). Notably, 81% of patients (155/191) who did not report a routine vitamin D intake presented with insufficient vitamin D levels (below 30 ng/mL), while only 19% of patients (36/191) had sufficient vitamin D levels. Of those who reported a routine vitamin D intake, 75% (43/58) had sufficient vitamin D levels, while 25% (15/58) showed insufficient vitamin D status. Patients who did not routinely take any vitamin D supplements had significantly lower vitamin D levels compared to patients who reported regular vitamin D intake (19.91 ng/mL vs. 40.66 ng/mL). Further, BMI and nicotine abuse were identified as potential risk factors for hypovitaminosis D in patients without vitamin D supplementation. Moreover, the season of spring seems to be a risk factor in patients with vitamin D supplementation, while age itself did not appear to be a significant risk factor for low vitamin D levels. In conclusion, we found an alarmingly high rate of vitamin D deficiency in patients scheduled to undergo rTJA. Notably, reported routine vitamin D supplementation showed significantly increased serum vitamin D levels compared to patients with no reported supplementation. Due to the high prevalence of vitamin D deficiency, we believe that vitamin D status should routinely be assessed in patients who are scheduled to undergo rTJA.

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.

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.

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.

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.

Trends in Computer-Assisted Surgery for Total Knee Arthroplasty in Germany: An Analysis Based on the Operative Procedure Classification System between 2010 to 2021.

Alignment strategies for primary total knee arthroplasty (TKA) have changed significantly over time with a shift towards a more individualized alignment goal. At the same time, computer-assisted surgery (CAS) has gained interest for intraoperative control and accuracy in implant positioning and limb alignment. Despite the often discussed benefits and drawbacks of robotics and navigation for TKA, the routine use of these new devices on a day-to-day basis remains obscure. Therefore, nationwide hospital billing data based on the Operation Procedure Classification System (OPS) were retrieved from the Federal Statistical Office of Germany for the period from 2010 to 2021. OPS codes for primary total knee arthroplasty (OPS code: 5-822*) were further analyzed regarding the usage of computer navigation (additional OPS code: 5-988) or robotic devices (additional OPS code: 5-987). Gender and age at the time of surgery were also assessed. The results show a total of 2,226,559 primary TKAs were implanted between 2010 and 2021, of which 2,044,914 were performed conventionally (91.84% of all TKAs). A total of 170,276 TKAs were performed using navigation technique (7.65% of all TKAs) and another 11,369 TKAs were performed using robotics (0.51% of all TKAs). For the period from 2018 to 2021, a substantial increase in robot-assisted TKA (R-TKA) was observed, with an average increase rate of 84.74% per year, while the number of navigated TKAs declined (-3.67% per year). Computer-assisted surgery, and particularly robotics for TKA, are seeing growing popularity and stepwise translation into routine clinical use in Germany, with a steep increase rate of more than 80% per year since 2018. Nevertheless, the majority of TKAs are still performed using manual instrumentation, rendering conventional TKA the currently unchanged gold standard.