Clinical characteristics of sarcoma patients: a population-based data analysis from a German clinical cancer registry.

PURPOSE: Sarcomas are a heterogeneous group of malignant neoplasms with a wide range of histological types and occur in almost any anatomic site and side. This study evaluated the prognostic factors in sarcoma patients based on German clinical cancer registry data. METHODS: The German clinical cancer register of Saxony-Anhalt was used for all data analyses. Sarcoma cases of all clinical or pathological T-stages (T1a-T4c), all N-stages (N0-3) and M-stages (0-1b) corresponding to the Union for International Cancer Control (UICC) stages I to IVB were considered. In our analyses, 787 cases diagnosed between 2005 and 2022 were included. Further, we assessed the association of cancer-related parameters with mortality and hazard ratios (HR) from the Cox proportional hazard models. We included sex, age at diagnosis, histological grade, T-, N- and M-stages, tumor size, tumor localization and tumor side as parameters in our regression models. RESULTS: The majority of sarcoma patients were diagnosed with leiomyosarcoma (12%), liposarcoma (11%), angiosarcoma (5.3%) and myxofibrosarcoma (2.7%). In our univariate regression models, tumors localized in more than one location, head, face and neck region as well as the pelvis and lower extremity were associated with increased mortality risk (more than one location: HR 7.10, 95% CI 2.20-22.9; head, face and neck: HR 1.35, 95% CI 0.89-2.06; pelvis: HR 1.27, 95% CI 0.86-1.89; lower extremity: HR 1.44, 95% CI 1.05-1.96). Higher histological grades, UICC-grades and TNM-stages were related to a higher mortality risk. Differing histological subtypes had significant influence on overall survival and progression-free survival. Patients diagnosed with fibromyxoid sarcoma, rhabdomyosarcoma and angiosarcoma were related to higher mortality risk compared to other histological subtypes (fibromyxoid sarcoma: HR 5.2, 95% CI 0.71-38.1; rhabdomyosarcoma: HR 2.93, 95% CI 1.44-6.00; angiosarcoma: HR 1.07, 95% CI 0.53-2.18). CONCLUSIONS: Histological grade, tumor size, nodal and distant metastasis, tumor localization and histological subtype were determined as prognostic factors in terms of survival.

[Periprosthetic infection after total hip replacement : Risk factors for an early infection after primary implantation]. / Periprothetischer Infekt nach Hüftprothesenimplantation : Risikofaktoren für die Entwicklung einer Frühinfektion nach Primärimplantation.

BACKGROUND: Periprosthetic infection is one of the most serious complications in primary arthroplasty. The infection rates reported in the current literature range from 0.36 to 2.23%. OBJECTIVES: The aim of this retrospective case-control study was to determine preoperative risk factors for the occurrence of early periprosthetic infection after primary hip arthroplasty. MATERIALS AND METHODS: The influence of patient age, gender, body mass index (BMI), C­reactive protein, preoperative leukocyte count and morbidity level (American Society of Anaesthesiologists score) on the occurrence of periprosthetic early infection of the hip joint was examined, and their correlation was investigated. RESULTS: Of the 1383 patients followed up, 25 were diagnosed with early infection. With an increase in BMI of 1 kg/m2, the risk of periprosthetic early infection increased by 12.1% (p < 0.001). In addition, using the receiver operating characteristic (ROC) curve, a BMI ≥ 29 kg/m2 is identified as a significant cut-off for the increased likelihood of periprosthetic hip infection. Using the ROC curve, a preoperative CrP value > 5 mg/l can be validated as a cut-off value for an increased risk of early infection. Using binary logistic regression, no influence of CrP > 5 mg/l on the development of early infection was statistically proven (p = 0.065). CONCLUSIONS: Patients with a BMI ≥ 29 kg/m2 should be informed about the increased risk of periprosthetic early infection after hip prosthesis implantation and a risk assessment should be performed. Furthermore, the determination of the preoperative CrP value should be considered standard.

Correction to: The High Flex Total Knee Arthroplasty-Higher Incidence of Aseptic Loosening and No Benefit in Comparison to Conventional Total Knee Arthroplasty: Minimum 16-Years Follow-Up Results.

[This corrects the article DOI: 10.1007/s43465-020-00276-3.].

Correction to: The High Flex Total Knee Arthroplasty-Higher Incidence of Aseptic Loosening and No Benefit in Comparison to Conventional Total Knee Arthroplasty: Minimum 16-Years Follow-Up Results.

[This corrects the article DOI: 10.1007/s43465-020-00276-3.].

Retrospective Clinical and Radiological Outcomes of Total Hip Arthroplasty in 51 Patients After a Mean 8.2 Years Using the Nanos® Short-stem Prosthesis.

INTRODUCTION: Over the past several years, femoral short-stem hip implants have become more popular as a treatment option in the field of primary hip arthroplasty for younger and more active patients. Current data on clinical outcomes and the implant survival rates in patients with short-stem implants cover a maximum of five to six years. The aim of this study was to assess the survival rates, as well as clinical and functional outcomes, in total hip arthroplasty (THA) using the Nanos® short-stem implant (Smith & Nephew, Marl, Germany) over a follow-up period exceeding 5 y. MATERIALS AND METHODS: This single-center retrospective study included the first 100 patients who were treated at the Department of Orthopedics at the University Hospital Halle (Saale) between January 2008 and February 2009. Ultimately, the complete data of 51 patients (54 hips) were reviewed. The follow-up period was from May to November 2017. We evaluated patient satisfaction regarding pain and function using a grading system. The Harris Hip Score and Forgotten Joint Score were obtained to evaluate functional outcome after THA. Postoperative radiographic evaluation included the measurement of leg-length discrepancy, changes in the shaft axis, femoral offset and horizontal or vertical center of rotation. Potential postoperative shaft angulation or axial shaft migration was also determined. Radiographic images were checked for radiolucent lines and heterotopic ossification using the classification systems outlined by Green and Brooker. RESULTS: The average follow-up was 97.8 months (8.2 y). The mean patient age at follow-up was 68 y and the body mass index was 28.2 kg/m2. The mean Harris hip score at follow-up was 92.0 and the Forgotten Joint Score was 91.7 %. Survey results showed that patient satisfaction and pain perception were rated very good. No significant change in leg length was observed (mean: 0.1 mm shortening). Overall, a rather varus stem positioning was detected postoperatively (mean: 3.1°). The femoral offset was slightly reduced on average in the entire patient group (mean: -1.8 mm). In the horizontal plane, lateralization of the center of rotation was detected overall (mean: 0.7 mm). In the vertical plane, cranialization was noted (mean: 1.4 mm). The CCD angle did not change. There was no further stem migration postoperatively. Radiolucent lines occurred in 10 cases in Gruen zones 1 and 7. Heterotopic ossification occurred in stages 1 to 3 according to the Brooker classification system. We found no cases of aseptic loosening or other reasons for revision. CONCLUSION: The outcomes after a mean follow-up of 97.8 months (8.2 y) showed that high levels of patient satisfaction and functional outcome can be achieved with the use of a short-stem endoprosthesis. Sufficient restoration of the patient's individual anatomy paired with high survival rates makes this short-stem prosthesis a reliable implant in total hip arthroplasty.

The High Flex Total Knee Arthroplasty-Higher Incidence of Aseptic Loosening and No Benefit in Comparison to Conventional Total Knee Arthroplasty: Minimum 16-Years Follow-Up Results.

PURPOSE: This prospective randomized study compares the clinical and radiographic long-term results at least 16 years after total knee arthroplasty (TKA) between a mobile-bearing high flex and a fixed-bearing posterior-stabilized knee. METHODS: In 2000, we included 60 patients who underwent a TKA. Patients were divided into two groups. At the time of the follow-up after a minimum of 16 years (16.5 years ± 0.6), 16 patients had died for causes unrelated to the operation, 15 were lost to the follow-up. Five patients of the high flex group had a revision. The final evaluation included the hospital for special surgery score (HSS) and radiographs. Using the X-rays and the Knee Society Roentgenographic Evaluation and Scoring System, radiolucent lines and the maximal knee flexion were determined. RESULTS: No significant differences between the two groups were found. The mean HSS score of LPS group patients was 87.9 (± 10.6) points and that of the high flex group was 93.1 (± 7.4) points. Five patients of the high flex group had undergone a reoperation. One knee was revised for painful mid-flexion instability and the others for symptomatic aseptic loosening of the components. CONCLUSION: The long-term follow-up does not show any clear benefits and even a higher incidence of implant loosening using the mobile-bearing high-flex knee.

Superior clinical results and higher satisfaction after customized compared with conventional TKA.

Investigation of functional outcome and patient`s satisfaction after implantation of a customized versus conventional TKA. In 31 consecutively enrolled patients with primary gonarthrosis, 33 customized TKA (custTKA) and in 31 patients, a conventional TKA (convTKA) was implanted. Perioperative and postoperative management were identical. Radio- graphic evaluation, ROM, KSS (Knee society score) and WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) were performed and patients satisfaction was evaluated after 3 and 12 months. Groups were comparable for age, sex, body mass index and extension/flexion. After 92 days average flexion in the convTKA group was significantly higher (119 vs. 113 degrees; unpaired t-test). At 375 days, mean flexion in both groups was 120 degrees. There was a significant higher number of outliers of neutral mechanical axis for convTKA patients (11 vs. 3; Chi-squared test). After 92 days there was no difference for KSS (convTKA: 160, custTKA: 167) but significant better results for WOMAC (19 vs. 40) in the custTKA group (unpaired t-test, p= 0.02). In addition, significantly better KSS (181 vs. 156) and WOMAC (99 vs. 42) were found for the custTKA group at 375 days (unpaired t-test, p= 0.002 and 0.001). Patients with the custTKA implant reported significant higher fulfillment of their expectations regarding function and knee strength. In the present study, the patients with a custTKA implant showed significantly superior short-term clinical results and fulfillment of their expectations regarding knee function.

Comparative Results of Percutaneous Calcaneal Osteotomy in Correction of Hindfoot Deformities.

BACKGROUND:: Calcaneal osteotomies are often required in the correction of hindfoot deformities. The traditional open techniques, which include a lateral or oblique incision, are occasionally associated with wound healing problems and neurovascular injury. METHODS:: A total of 122 consecutive patients who underwent a calcaneal osteotomy for hindfoot realignment treatment were included. Fifty-eight patients were operated using an open incision technique and 64 patients (66 feet) using a percutaneous technique. Clinical and radiologic assessments were performed preoperatively, at 6 weeks, and 1 year postoperatively. RESULTS:: The American Orthopaedic Foot & Ankle Society scale scores and visual analog scale pain scores improved in both groups postoperatively. The difference between the groups was not significant. The results of the radiologic measurements pre- and postoperatively were not significantly different. No pseudarthrosis occurred in either group. The comparison of both groups showed a significantly lower risk for wound healing problems in the percutaneous group. The hospitalization time was significantly shorter in the percutaneous group. CONCLUSION:: Because of the excellent results with the percutaneous calcaneal osteotomy, the authors feel encouraged to establish this procedure as a standard technique for calcaneus osteotomy, especially patients at high risk for wound healing problems. LEVEL OF EVIDENCE:: Level III, comparative series.

A prospective randomized radiographic and dual-energy X-ray absorptiometric study of migration and bone remodeling after implantation of two modern short-stemmed femoral prostheses.

BACKGROUND: The aim of this prospective randomized study was to analyze migration and strain transmission of the Metha™ and Nanos™ femoral prostheses. MATERIALS AND METHODS: Between 1 January 2011 and 2 April 2013, 50 patients were randomized to receive short-stemmed femoral prostheses. Metha™ stems were implanted in 24 patients (12 female, 12 male; mean age 58.7 years; mean body mass index [BMI] 27.4) and Nanos™ stems in 26 patients (10 female, 16 male; mean age 59.7 years; mean BMI 27.1). Longitudinal stem migration, varus-valgus alignment, changes of center of rotation (COR), femoral offset and caput-collum-diaphyseal angle, leg length discrepancy, periprosthetic radiolucent lines incidence, and dual-energy X-ray absorptiometry (DEXA) scans were analysed after an average of 98 and 381 days. RESULTS: There was no significant change of varus-valgus alignment or clinically relevant migration of the Metha™ or Nanos™ prostheses during postoperative follow-up. After 12.3 months, the DEXA scans showed small but significant differences of bone mineral density in Gruen zones 1 (minus ~8 %) and 6 (plus ~9 %) for the Metha™ and in Gruen zone 1 (minus ~14 %) for the Nanos™ (paired t test). Visual analog scale (VAS) and Harris Hip Score (HHS) improved significantly for both implants (Nanos™/Metha™ 12.3 months postoperatively HSS 96.5/96.2; VAS 0.7/0.8, respectively). COR or offset did not change significantly after surgery. CONCLUSIONS: Neither implant showed signs of impaired osseointegration. DEXA demonstrated proximally located load transfer with only moderate proximal stress shielding. LEVEL OF EVIDENCE: II.

Calcaneocuboid distraction arthrodesis with allogenic bone grafting for correction of pes planovalgus.

Calcaneocuboid distraction arthrodesis is regarded as an excellent and reliable surgical procedure for correction of pes planovalgus. Despite a potentially high complication rate, the use of an autologous iliac crest graft is regarded as the method of choice. In a prospective trial the results in 12 feet after calcaneocuboid distraction arthrodesis for pes planovalgus correction with allogenic bone graft were investigated. The mean age was 64 (52-81) years. An angle-stable plate was generally used for fixation of the arthrodesis. Successful bone healing was diagnosed clinically if local pain was absent during weight bearing, forefoot manipulation and palpation. The AOFAS score improved from 58.9 (+/- 6) points preoperatively to 89.8 (+/- 6.3) points 12 months postoperatively and the Visual Analogue Pain Scale (VAS) from 5.1 (+/- 1.4) to 0.7 (+/- 1) 12 months postoperatively. On radiological analysis, the lateral and dorsoplantar talometatarsal axis, hindfoot axis, the navicular floor distance and talonavicular coverage angle improved considerably. Bone fusion was observed in 11 of 12 cases postoperatively. In conclusion, the use of an allogenic graft for calcaneocuboid distraction arthrodesis did not result in a higher pseudarthrosis rate compared with results reported after use of an autologous iliac crest graft. Fixation with an angle-stable plate is recommended.

A prospective dual-energy X-ray absorptiometry study of bone remodeling after implantation of the Nanos short-stemmed prosthesis.

The aim of this study was to analyze the bone remodeling around the Nanos stem (Smith & Nephew, Marl, Germany) after primary total hip arthroplasty for coxarthrosis. In 25 patients (15 male, 10 female, mean age 59.9 years) with the diagnosis of coxarthrosis, a DEXA scan was performed immediately after surgery, 97 days (SD 6.1 days) and 368 days (SD 6.2 days) after implantation of a Nanos prosthesis. Plain radiographs were analyzed digitally for radiolucent lines, varus-valgus femoral stem alignment, measurement of stem migration and changes in varus-valgus femoral stem alignment. The position of the center of rotation (COR) and the offset were assessed pre- and postoperatively. Harris Hip Score was used to evaluate the clinical outcome. The DEXA scan showed a significant and relevant increase in BMD (Bone Mineral Density) in Gruen-Zone 6 (12%) and a decrease in Zone 1 (15%), 2 (5%) and 7 (12%), which was interpreted as reflecting a distal load transfer in the metaphysis of the femur. There was no clinically relevant migration or tilting of the Nanos stem. Radiolucent lines were noted in 12 cases, mainly at the polished tip area of the prosthesis; this was not regarded as a sign of impaired osseointegration. There was no significant difference between the position of the COR and the pre- and postoperative offset. The absence of stem migration, angulation, or relevant radiolucent lines is seen as evidence for an unimpaired osseointegration of the Nanos stem approximately 12 months after implantation. It is concluded that the Nanos prosthesis can reduce loss of BMD of the proximal femur composed with conventional stems or other short-stemmed implants.

Is there a stable vertebral height restoration with the new radiofrequency kyphoplasty? A clinical and radiological study.

PURPOSE: The aim of this study is to evaluate whether radiofrequency kyphoplasty can restore vertebral body height in osteoporotic vertebral fractures and whether restoration of vertebral height correlates with decreased pain. METHODS: In a prospective study from December 2010 to October 2011, 25 patients underwent RF kyphoplasty for 30 fresh osteoporotic vertebral fractures. The parameter demographics, pain relief, restoration of vertebral body height (mean vertebral body height, kyphosis angle, anterior/posterior edge height) and all complications were recorded. RESULTS: Mean age of patients was 73.8 ± 9.6 (range, 55-83); time from initial painful fracture to treatment was 3.0 weeks ± 1.2; average operative time was 23.5 min (range, 15-41). Average pain index score decreased significantly from 69 ± 8.5 preoperatively to 34.4 ± 5.9 postoperatively (p < 0.001), and to 30 ± 6.3 (p < 0.001) after 3 months. Mean vertebral body height, anterior edge height and kyphosis angle showed significant increases postoperatively and at 3-month follow-up (p < 0.05). In two vertebrae (6.6 %), minimal, asymptomatic cement leakage occurred in the upper disc. After 2 months, one new fracture (3.3 %) was identified in the directly adjacent segment that was also successfully treated with radiofrequency kyphoplasty. There was a preliminary correlation between mean vertebral body height elevation and cement volume (r = 0.533). CONCLUSION: Radiofrequency kyphoplasty achieves rapid and lasting improvement in clinical symptoms. There was stable restoration of vertebral body height with a mean cement volume of 3.0 ml ± 0.6. There was no correlation between restoration of vertebral body height and pain relief.

Treatment of aseptic loosened MTPI prosthesis by one-stage revision with ToeFit Plus prosthesis.

INTRODUCTION: Due to the missing bony integration of the ceramic Moje prosthesis for replacing the first metatarsophalangeal joint (MTPI) in hallux rigidus, the mid-term results were bad so far. In case of revision, the distraction arthrodesis with autologous bone taken from the iliac crest as a salvage procedure is the method of choice. METHOD: In our prospective case series, the short-term results after revision of the Moje prosthesis with the ToeFit Plus prosthesis were investigated. The clinical and radiological investigations were done in six MTPI over a 24-month period using AOFAS score and visual analogue scale. RESULTS: There were no radiological signs of loosening or implant migration of the ToeFit Plus 24 months, postoperatively. There was one fissure at the first proximal phalanx necessitating a wire stabilisation. No other complications could be observed. A significant improvement of the AOFAS score and the range of motion were observed 6 weeks postoperatively. CONCLUSION: We could show good and very good short-term results after the replacement of a loosened MTPI prosthesis with a ToeFit Plus. Due to the conic screw anchorage, ToeFit Plus is excellently suited for prosthesis replacement at the MTPI. With sufficient bony anchorage prerequisites, it is possible to preserve and improve the range of motion by changing the loosened MTPI prosthesis in the ToeFit Plus, thereby avoiding the morbidity of gaining autologous bone from the iliac crest.

Quality of life and radiological outcome after cervical cage fusion and cervical disc arthroplasty.

In this retrospective comparative study, 42 patients with single-level cervical radiculopathy were operated upon, either with Shell cage fusion (23 patients) or with Prestige cervical disc arthroplasty (19 patients). The mean follow-up (FU) was 17.5 months (range: 5.6-42.1 months). Both treatments significantly improved all clinical parameters (VAS, ODI, SF36) (p < 0.001), without statistically relevant differences between the two groups. From a radiological viewpoint there was an obvious but statistically non-significant increase in the segmental height for both treatment groups. Segmental angle also increased in both groups, and the increase was significant (p < 0.05). As expected, range of motion (ROM) decreased significantly (p < 0.05) in the fusion group, while it was preserved in the arthroplasty group. Significantly more (p < 0.05) adjacent level degeneration class 1 to 4 was evident in the fusion group (8/23 or 34.8%) than in the arthroplasty group (3/19 or 15.8%). Two fusion patients (2/23 or 8.7%) developed painful clinical adjacent level disease requiring arthroplasty. The major conclusion was that significant adjacent level degenerative changes occurred in the cage group. Retained motion at the operative site seems to decrease the incidence of adjacent level degeneration. Implant subsidence was recorded at FU in 8 out of 42 patients (19%). It occurred significantly (p < 0.05) more often in the fusion group (6/23 or 26.1%) than in the arthroplasty group (2/19 or 10.5%), but it did not cause clinical symptoms. As in other studies, there is no explanation as to why better radiological results did not translate into better clinical outcomes within the time limits of the study.

Is there an increased stem migration or compromised osteointegration of the Mayo short-stemmed prosthesis following cerclage wiring of an intrasurgical periprosthetic fracture?

AIM: Short-stemmed prostheses are increasingly regarded as implants of first choice in primary THA. As a result of the press-fit fixation in the femoral metaphysis, the occurrence of intraoperative fractures were reported. The aim of this study was to analyze the postoperative results of the Mayo short-stem prosthesis following treatment of an intrasurgical femur fracture with cerclage wiring. PATIENTS AND METHODS: From 1999 to 2005, in 38 patients (18 females, 20 males; mean age 56 years; mean BMI = 27) with the diagnosis of coxarthrosis in whom a Mayo short-stemmed prosthesis has been implanted, an intraoperative fracture was observed. The fractures were treated with cerclage wiring (1 cerclage, n = 32; 2 cerclages, n = 5; 3 cerclages, n = 1). Postoperatively, all patients were prescribed mobilization without weight-bearing (floor contact) on the treated leg for 6 weeks. Using the Wristing software, longitudinal stem migration and varus-valgus femoral stem alignment were examined digitally in anteroposterior X-rays taken immediately after surgery, after 6 weeks and on average after 5.7 years (Zeh et al., Z Orthop Unfall 149:200-205, 2011). Additionally, the incidence of periprosthetic radiolucent lines was captured in the anteroposterior X-rays and assigned to the Gruen zones. Additionally, a DEXA scan was performed. The X-rays of a matched control group after the implantation of a Mayo prosthesis without femur fracture were analyzed by the same method. RESULTS: There was no significant migration of the Mayo prosthesis in the study or control groups during postoperative follow-up (t test, P > 0.05). The cerclage group compared with the control group showed a statistically significant valgus tilt of 1.5° on average during the follow-up, which is regarded to be clinically not relevant. The frequency of occurrence of radiolucent lines was not statistically different (chi-square test, χ = 0.42, P = 0.51). DEXA scans showed no differences of the bone mineral density in the Gruen zones compared with a historical control group. CONCLUSION: After wiring of an intrasurgical fracture, no disadvantage could be proven for Mayo prosthesis regarding stem migration and varus-valgus alignment. Furthermore, due to the absence of differences in the occurrence of radiolucent lines and the same results in the DEXA scan, an unimpaired osseointegration is assumed.

The Aquamantys system--an alternative to reduce blood loss in primary total hip arthroplasty?

To evaluate the effectiveness of the Bipolar Sealer 6.0-VT (BPS 6.0-VT) (Tissue Link Medical, Inc, Dover, NH) in reducing blood loss compared with a conventional electrocautery (Erbe ICC 350) (Erbe ICC 350 (ERBE Elektromedizin GmbH, Tübingen, Germany). A prospective randomized trial of 105 patients with primary total hip arthroplasty (Erbe ICC 350: 50 patients; BPS 6.0-VT: 55 patients). On the basis of the calculation of the preoperative blood volume the total and postoperative blood loss were calculated. No statistically significant difference could be shown for total intraoperative and postoperative blood loss (group A 1846 mL; group B 1740 mL) (t test). Due to the lack of reduction of blood loss and the high costs of the BPS 6.0-VT, its use is not recommended in primary total hip arthroplasty.

[Quadsparing approach in total knee arthroplasty]. / Quadsparing-Zugang bei Knietotalendoprothesenimplantation.

OBJECTIVE: Approach to the knee joint for total knee arthroplasty (TKA) with gentle soft-tissue handling. INDICATIONS: Primary TKA with range of motion>or=100 degrees, leg axis up to 10 degrees varus or valgus, body weight<100 kg. CONTRAINDICATIONS: Contracted knees, leg axis>10 degrees varus or valgus, obesity, previous knee surgery except arthroscopic procedures, rheumatoid arthritis. SURGICAL TECHNIQUE: Anterior midline incision. Soft-tissue preparation and capsule incision start at the upper tip of the patella and are continued distally along the medial patellar border ending at the tibial tuberosity. After opening of the joint, the patella is dislocated laterally without everting it. Exposure of the articular surface using a "mobile window". Preparation and insertion of the TKA components using special instruments. Wound closure in layers. POSTOPERATIVE MANAGEMENT: Mobilization on crutches with full weight bearing starting on the day of surgery. Daily medical training therapy. Passive motion therapy continued twice a day. Low-dose heparin s.c. for 35 days after surgery. RESULTS: In a prospective randomized clinical study, 50 patients with a quadsparing (QS) approach were observed up to 3 months after surgery. In three patients, the use of large femoral components required an extended approach. During the hospital stay knee flexion was significantly greater in patients with the QS approach than in patients with the standard procedure (midvastus approach). There were no differences in implant positioning, Knee Society Score and complication rate between both groups. Use of the QS approach prolonged the duration of surgery by 25 min.

Time-dependent release of cobalt and chromium ions into the serum following implantation of the metal-on-metal Maverick type artificial lumbar disc (Medtronic Sofamor Danek).

INTRODUCTION: In total hip endoprosthetics and consequently for TDA, metal-on-metal combinations are used with the aim of reducing wear debris. In metal-on-metal TDA the release of metal ions has until now been secondary to the main discussion. MATERIALS AND METHODS: In order to investigate the ion release following the implantation of the metal-on-metal Maverick type artificial lumbar disc we measured the serum cobalt and chromium concentration following implantation of 15 Maverick TDAs (monosegmental L5/S1, n = 5; bisegmental L4/5 and L5/S1, n = 5; average age 36.5 years). Five healthy subjects (no metal implants) acted as a control group. The two measurements of the metals were carried out using the absorption spectrometry after an average of 14.8 and 36.7 months. RESULTS: In summary, the concentrations of cobalt and chromium ions in the serum at both follow-ups amounted on average to 3.3 microg/l (SD 2.6) for cobalt and 2.2 microg/l (SD 1.5) for chromium. These figures are similar to the figures shown in the literature following the implantation of metal-on-metal THA. After a comparison to the control group, both the chromium and cobalt levels in the serum showed visible increases regarding the first and the second follow-up. DISCUSSION: As there is still a significant release of cobalt and chromium into the serum after an average follow-up of 36.7 months a persistent release of these ions must be taken into consideration. Despite the evaluation of the systemic and local effects of the release of Cr/Co from orthopaedic implants has not yet been concluded, one should take into consideration an explanation given to patients scheduled for the implantation of a metal-on-metal TDA about these results and the benefits/risks of alternative combinations of gliding contact surfaces.

Clinical and radiological results of high flex total knee arthroplasty: a 5 year follow-up.

INTRODUCTION: In a prospective randomized study, we compared the results after implantation of the mobile bearing high flex TKA with a fixed bearing posterior stabilized TKA in 60 patients (30 patients each group). METHOD: We evaluated the hospital for special surgery-score (HSS) and different radiological parameters preoperatively, as well as 3 months, 3 and 5 years postoperatively. RESULT: Three months postoperatively, the high flex group showed better results in scores for pain, ROM (122.5 degrees vs. 107.33 degrees), as well as in the overall HSS (87.21 vs. 82.68 points). Three and 5 years postoperatively, there were no differences between both the groups in all scores, but the HSS is still increasing. CONCLUSION: The theoretical advantages of the mobile bearing knee prostheses were reflected in the clinical results, only partly and temporarily.

Early results with the Genesis II Posterior Stabilized High Flexion knee prosthesis. A one year follow-up study.

The aim of this prospective study was to assess the range of motion (ROM) achieved with the Genesis II Posterior Stabilized High Flexion knee prosthesis. The ROM was compared with that of a historical study group with the standard PS insert and an identical study design. Sixty three patients with primary knee osteoarthritis (37 female, 26 male; average age: 67.0 years, average BMI 31.2) underwent primary cemented TKA with a PS high flex insert. The surgery was performed by one senior author using a mini-midvastus approach. During the follow-up no statistically significant difference in maximal flexion was found between 14 weeks (average flexion = 120 degrees, SD = 11.2) and 65 weeks postoperatively (average flexion = 122 degrees, SD = 8.9). The radiographic evaluation showed no influence of the implant positioning on the final flexion. Compared to the results obtained in a 5 year follow-up study of 100 cases in combination with the PS standard insert, the improvement in final flexion range found in this study did not appear not to be great enough to generally recommend the PS high flex insert in terms of a proven higher flexion result.