[Postoperative spinal column]. / Postoperative Wirbelsäule.

STANDARD PROCEDURE: As a rule, postoperative imaging is carried out after spinal interventions to document the exact position of the implant material. INFORMATION: Imaging is absolutely necessary when new clinical symptoms occur postoperatively. In this case a rebleeding or an incorrect implant position abutting a root or the spinal cord must be proven. In addition to these immediately occurring postoperative clinical symptoms, there are a number of complications that can occur several days, weeks or even months later. These include the failed back surgery syndrome, implant loosening or breakage of the material and relapse of a disc herniation and spondylodiscitis. REVIEW: In addition to knowledge of the original clinical symptoms, it is also important to know the operation details, such as the access route and the material used. RECOMMENDATION: In almost all postoperative cases, imaging with contrast medium administration and corresponding correction of artefacts by the implant material, such as the dual energy technique, correction algorithms and the use of special magnetic resonance (MR) sequences are necessary. RECOMMENDATION: In order to correctly assess the postoperative imaging, knowledge of the surgical procedure and the previous clinical symptoms are mandatory besides special computed tomography (CT) techniques and MR sequences.

[Perioperative morbidity in lumbar disc replacement]. / Perioperative Morbidität bei lumbaler Bandscheibenprothesenimplantation.

AIM: For several years now interbody fusion has been the gold standard procedure for treating degenerative disc disease. The problem of adjacent disc degeneration after interbody arthrodesis led to the development of non-fusion techniques. The device which best represents the philosophy of spine arthroplasty is the total lumbar disc replacement (TDR). An analysis of the perioperative morbidity of lumbar disc replacement was carried out in the current study. METHOD: 66 patients underwent lumbar disc replacement between 2001 and 2007. 78 protheses were implanted. Retrospectively patient-related variables (comorbidity, prior surgeries), perioperative blood loss, number and levels operated on, operation duration and technical and general complications were analysed. RESULTS: 54 patients had mono- and 12 patients bisegmental TDR. The mean operation time was 112 minutes with an average blood loss of 560 mL. Neither the type of comorbidity, prior surgery, operation duration, nor level operated on had an influence on the occurrence of perioperative morbidity. A significant influence could be shown for the number of levels operated on and the intraoperative blood loss. General complications were seen in 6 persons (9%) with urinary tract infection, technical complications occurred in 4 persons (6%) with severe blood loss (> 1500 mL) and erythrocyte/plasma substitution, 1 person (1.5%) with an injury of the iliac vein, 1 person (1.5%) with retrograde ejaculation and 1 person (1.5%) with dural tear and consecutive epidural infection. CONCLUSION: In our study the perioperative morbidity of lumbar disc replacement was similar to the data published so far and seems to be comparable with the perioperative morbidity of lumbar interbody fusion.

[Transfixation in slipped capital femoral epiphysis: long-term evidence for femoro-acetabular impingement]. / Transphysäre Fixation bei Epiphyseolysis capitis femoris: Hinweise für femoroazetabuläres Impingement im Langzeitverlauf.

AIM: It was the aim of this study to reveal whether and to what extent femoro-acetabular impingement (FAI) was present 10 to 20 years after transfixation of the gliding epiphysis in patients treated for unilateral slipped capital femoral epiphysis (SCFE). METHOD: Clinical and radiological evaluations were undertaken of 20 patients who were treated with a bilateral transfixation of the epiphysis with screws or Kirschner wires because of mild unilateral SCFE. The Harris hip score, the activity level according to Tegner and Lysholm and the range of motion of both hip joints were noted. An impingement provocation test was performed on both sides. The femoral head-neck junction was qualitatively and quantitatively assessed in anteroposterior radiographs of the pelvis and "cross table" lateral radiographs of both hip joints. Quantitative assessment was achieved by measuring the alpha angle according to Nötzli et al. RESULTS: All except one patient showed excellent results in the Harris hip score. The activity levels of the majority of patients, however, were mediocre. There was no difference for flexion, whereas internal rotation and abduction significantly differed between affected and non-affected hips (p = 0.135, p = 0.002 and p = 0.007, respectively). The impingement provocation test was found positive in eight affected and five non-affected hips (p = 0.004). The alpha angle was significantly different between affected and non-affected hips in the anteroposterior radiographs of the pelvis (86 vs. 61 degrees; p < 0.001), but not so, however, in the "cross table" lateral radiographs (52 vs. 46 degrees; p = 0.145). CONCLUSION: Clinical evaluation of 20 patients at a mean of 14.9 years after transfixation of the epiphysis revealed some evidence for the presence of FAI in affected hip joints. Radiological evaluation suggests that its localisation is more lateral and less anterior.

[Perioperative morbidity of lumbar stabilisation with Dynesys]. / Perioperative Morbidität bei Dynesys-Instrumentierung der Lendenwirbelsäule.

AIM: Several non-fusion technologies have been developed as an alternative to fusion procedures in the past decades, in order to avoid typical problems related to fusion. The Dynesys (Zimmer, USA), which was inaugurated 7 years ago, consists of pedicle screws, flexible spacers and cords and is intended to control segmental motion and to realign the lumbar spine. Since this device is new, it was the goal of this study to analyse the perioperative morbidity of lumbar stabilisation with Dynesys retrospectively. METHOD: 136 patients (74 men and 62 women) underwent posterior stabilisation of the lumbar spine with Dynesys between January 2002 and April 2006. We acquired retrospectively several patient-related variables, e.g. the number of instrumented and decompressed segments, the perioperative blood loss, the operation duration, prior surgeries and technical and general complications. RESULTS: The average age of the patients was 61.2 years (range: 33-84). 1.6 segments (range: 1-3) were instrumented and 1.2 segments (range: 0-3) were decompressed on average. The mean perioperative blood loss was 1100 ml (range: 50-3400) and the mean operation duration was 127.1 minutes (range: 30-270). Eighteen patients (13.2 %) had a urinary tract infection and 5 patients (3.7 %) had cardiovascular complications. Dura lesions were seen in 11 patients (8.1 %) with 1 patient having persistent bladder symptoms. Revision surgery was necessary in 3 patients (2.2 %) due to screw malposition with neurological deficits and radicular pain. Five patients (3.7 %) were revised due to postoperative seroma, 2 of them developing superficial infection. CONCLUSION: The perioperative morbidity of lumbar stabilisation with Dynesys seems to be similar to posterior fusion techniques. However, an additional morbidity due to interbody fusion, which may necessitate also autogenous bone, is avoided.

[Surgery of the cervical spine in rheumatoid arthritis. Diagnostics and indication]. / Operative Therapie an der Halswirbelsäule bei rheumatoider Arthritis. Diagnostik und Indikation.

The cervical spine is often affected in rheumatoid arthritis. Beside destructive changes, instabilities can occur, mainly in the upper cervical spine. Typical symptoms are missing so that routine x-ray examinations are needed to prevent severe consequences up to death. AP/lateral cervical spine x-rays and lateral functional x-rays are the standard diagnostic tool. Depending on the findings, further neurological examination and MRI must be initiated. Aim is the early recognition, respectively prevention of myelopathy. Therapy includes stage dependent conservative and surgical measures.

[Epiphyseal fracture of the proximal tibia: review of the literature and report of simultaneous bilateral fractures in a 13-year-old boy]. / Epiphysenfraktur der proximalen Tibia: Literaturübersicht und Fallbericht einer simultanen bilateralen Fraktur bei einem 13-jährigen Jungen.

Proximal tibial epiphyseal injury is a rare finding in adolescents. We report the case of a 13-year-old boy with simultaneous epiphyseal fractures of both proximal tibiae to illustrate appropriate diagnosis and treatment of this condition. The injury occurred while performing a long jump: a Salter-Harris type II fracture of the right proximal tibia was sustained at take-off and a Salter-Harris type III avulsion fracture of the left tibial tuberosity upon landing. Closed reduction and internal fixation using K-wires were performed on the right side, whereas open reduction and internal fixation were done on the left side, using a lag screw and additional McLaughlin wiring.

Radiological evidence of femoroacetabular impingement in mild slipped capital femoral epiphysis: a mean follow-up of 14.4 years after pinning in situ.

Conventional treatment of mild slipped capital femoral epiphysis consists of fixation in situ with wires or screws. Recent contributions to the literature suggest that even a mild slip may lead to early damage of the acetabular labrum and adjacent cartilage by abutment of a prominent femoral metaphysis. It has been suggested that the appropriate treatment in mild slipped capital femoral epiphysis should not only prevent further slipping of the epiphysis, but also address potential femoroacetabular impingement by restoring the anatomy of the proximal femur. Between October 1984 and December 1995 we treated 16 patients for unilateral mild slipped capital femoral epiphysis by fixation in situ with Kirschner wires. In this study we have reviewed these patients for clinical and radiological evidence of femoroacetabular impingement. There was little clinical indication of impingement but radiological evaluation assessing the femoral head-neck ratio and measuring the Nötzli alpha angle on the anteroposterior and cross-table radiographs showed significant alterations in the proximal femur. None of the affected hips had a normal head-neck ratio and the mean alpha angle was 86 degrees (55 degrees to 99 degrees ) and 55 degrees (40 degrees to 94 degrees ) on the anteroposterior and lateral cross-table radiographs, respectively. While our clinical data favours conventional treatment, our radiological findings are in support of restoring the anatomy of the proximal femur to avoid or delay the development of femoroacetabular impingement following mild slipped capital femoral epiphysis.

Comparative assessment of outcome in osteoarthritis of the knee: the utility of knee scores.

PURPOSE OF THE STUDY: The utility of scoring systems, which are used to determine health status or treatment benefit in patients with knee osteoarthritis is under discussion. Therefore it was the purpose of our investigation to evaluate the reliability and the concordance of two established knee scoring systems. METHODS: Thirty-eight patients with unilateral knee osteoarthritis were scored by the Hospital for Special Surgery score and the Knee Society score. Two blinded observers rated the patients independently in order to determine the concordance of the scores, the correlation between the overall scores and their subscales such as "pain", "function" and "range of motion" and the inter-observer and intra-observer reliability. RESULTS: There was a high correlation between the overall scores (r= 0.80) and between the scores and their subscales "range of motion" (r=0.89) and "function" (r=0.74). The correlation of scores for "pain" was slightly less (r=0.61). Mean inter-observer reliability ranged between r=0.58 and r=0.61. Mean intra-observer reliability was high for the overall scores as well as for the subscales of both scoring systems (r=0.64 to r=0.93 and r=0.73 to r=0.92). CONCLUSION: We have found that the assessment of overall scores as well as of their main subscales is concordant and reliable in our patient sample. The application of these scoring systems in measuring health status in patients with knee osteoarthritis appears to be an acceptable method of audit. However, we feel that presentation of the results of knee scoring systems should include detailed information on the main subscales, since this allows for a better understanding of results.

[The impact of preoperative function and pain on early patient-centred outcome after total hip arthroplasty]. / Der Einfluss von präoperativem Funktionsstatus und Schmerz auf das patientenzentrierte Frühergebnis nach Hüftendoprothesen-Implantation.

AIM: It was the purpose of this prospective study to investigate the impact of preoperative functional status and pain on the early patient-centred outcome after total hip arthroplasty (THA). METHODS: 67 consecutive patients scheduled for THA were included in this study. Outcome was analysed with the Western Ontario and McMaster Universities' (WOMAC) Osteoarthritis Index preoperatively and after ten days and 12 weeks, respectively. Patients were grouped with regard to their preoperative function and pain according to the WOMAC Osteoarthritis Index. Statistical analysis was performed using a multivariate regression model considering further confounding variables (age, gender, affected side, duration of surgery, and anchorage of THA). RESULTS: All patients showed a significant functional improvement both at ten days postoperatively and after three months, respectively. Patients with a higher degree of disability preoperatively had a larger relative functional improvement according to their WOMAC score compared to patients who initially were less deteriorated. However, the latter had the better absolute scores postoperatively. Multiple regression analysis revealed gender (OR: -11.85, 95% CI: -22.65 to -1.06, p=0.03) and preoperative WOMAC score (OR: 0.34, 95% CI: 0.09 to 0.59, p<0.01) to be significant prognostic variables at ten days postoperatively. After three months, age (OR: 0.43, 95% CI: 0.04 to 0.82, p=0.03) was the only variable predicting the patient-centred outcome. CONCLUSION: In our study sample, patient-related variables did significantly influence the patient-centred outcome after ten days (gender and WOMAC) and at three months postoperatively (age) whereas procedure-related variables did not have any impact.

[Predictive factors of perioperative morbidity in revision total hip arthroplasty]. / Prädiktoren der perioperativen Morbidität in der Revisionshüftendoprothetik.

AIM: The awareness and prevention of perioperative morbidity are essential in revision total hip arthroplasty [THA]. Therefore, it was the purpose of this study to assess the rate of perioperative complications following revision THA in order to evaluate the impact of patient- and procedure-related variables. METHODS: 169 consecutive patients with a mean age of 71.7 years suffering from aseptic loosening of their THA were included in this retrospective study. Multivariate logistic regression models with estimation of the odds ratio [OR] and 95% confidence interval [CI] served to analyze the influence of operation duration, gender, revision status, ASA classification, and type of fixation of the primary implant on the perioperative morbidity. RESULTS: 68.6% of the cases were primary revisions, and 31.4% secondary or multiple revisions. 49.7% of the operations involved exchange of the complete implant whereas 39.1% comprised exchange of the cup and 11.2% exchange of the stem only. Mean operation duration was 130 minutes [min] (range: 40-260 min), and mean intraoperative blood loss was 2.6 L (0.5 to 12 L). The rate of intraoperative complications was 10.1 % with a 6.5 % fracture rate. Postoperatively the complication rate was 25.4% with an 8.3% rate of luxations. 11.8% of the patients had revision within the first three weeks after surgery. Regression models showed the significant impact of revision status (primary vs. secondary or multiple: OR 2.90, 95% CI 1.42-5.92) and operation duration (per min starting from the mean operation time: OR 1.01, 95% CI 1.00-1.02) on the resulting complication rate. Analysis of the perioperative complication rate following primary revisions revealed a significant difference (p = 0.03) between patients with cemented (15/36, 41.7%) and non-cemented (8/45, 17.8%) implants. CONCLUSIONS: Revision status with a three-fold increase in patients with multiple revisions as well as operation duration with a 1 % increase per min starting from the mean operation time significantly influence the perioperative morbidity. Patients with a first revision, furthermore, seem to be at greater risk for an adverse event perioperatively if their implant is fully cemented. These findings should be taken into account prior to initiating surgery.

[In vitro investigation of posterior cruciate ligament strain following total knee arthroplasty]. / In-vitro-Untersuchung der Spannung des hinteren Kreuzbandes nach primärer Knieendoprothetik.

AIM: The aim of this biomechanical in vitro study was to assess posterior cruciate ligament (PCL) strain following two different total knee arthroplasty (TKA) designs (fixed versus mobile) with regard to modification of the tibial slope. MATERIAL AND METHODS: We investigated eight Natural Knee I (NK I) prosthesis with fixed bearing and eight Low Contact Stress (LCS) prosthesis with mobile meniscal bearings. TKA was performed using fresh frozen human cadaveric knee joints. PCL strain was measured with implantable force transducers. Knee kinematic assessment was made with a load of 300 Newton and without load using a six-degrees-of-freedom testing device. Modification of the tibial slope was analysed radiographically. Statistical analysis was performed using Student's t test, Wilcoxon rank sum test, and the Spearman coefficient of correlation. RESULTS: Assessment of the tibial slope showed a non-significant increase of 2.1 degrees (p = 0.14) following TKA using the NK I, and of 1.1 degrees (p = 0.12) using the LCS, respectively. Analysis of PCL strain following implantation of the NK I prosthesis revealed non-significant alterations both with (p = 0.74) and without load (p = 0.20). Concerning the LCS prosthesis, a significant decrease in PCL strain was seen with load (p = 0.01), whereas non-significant modifications were measured without load (p = 1.0). The modified tibial slope and modified PCL strain following LCS TKA showed no (with load: r (s) = 0.01) and modest correlation (without load: r (s) = - 0.43), respectively, whereas it was substantial following NK I TKA (with load: r (s) = 0.64, without load: r (s) = 0.70). CONCLUSION: As the NK I prosthesis allows PCL tension to be close to normal as the knee flexes, it can be stated that regular PCL tension after TKA is restorable and, moreover, it can be hypothesised that the effected tension of the PCL mainly depends on the interaction between design of the implant (fixed/mobile) and the functional role of the PCL.

[Osteoporosis--a neglected issue in orthopaedics? Results of a survey amongst German orthopaedic surgeons]. / Osteoporose -- Ein Stiefkind der Orthopädie? Ergebnisse einer Befragung deutscher Orthopäden.

AIM: Patients with fragility fractures have a significantly increased risk of sustaining additional fractures. Therefore one should consider avoidance of further fractures as the primary treatment principle. Since orthopaedic surgeons manage most of fragility fractures, but might not be well attuned to osteoporosis itself, it was the aim of the Bone and Joint Decade (BJD) and the International Osteoporosis Foundation (IOF) to survey orthopaedic surgeons in order to assess their knowledge of prevention, diagnosis, and treatment of osteoporosis. MATERIAL AND METHODS: The multinational survey questionnaire was developed by a working group of national project co-ordinators in France, Germany, Italy, Spain, the United Kingdom, and New Zealand and based to some extent on an American survey. Following translation into the national language it was distributed in 2002 to the members of the orthopaedic societies to assess the management of prevention, diagnosis, and therapy of osteoporosis and fragility fractures, comparing both different health-care systems and different working environments. 5 700 questionnaires were distributed in Germany with a 20 percent response rate. RESULTS: As the main result of the German survey -- independent of the working environment -- a substantial deficit concerning training and knowledge about the management of prevention, diagnosis, and treatment of osteoporosis and fragility fractures was seen. In addition, the majority of participants requested educational opportunities to become qualified for a better disease control. CONCLUSION: In order to satisfy the increasing need for adequate management of prevention, diagnosis, and therapy of osteoporosis and fragility fractures, structured educational opportunities have to be offered to the German orthopaedic community. In the mean time first steps have been initiated: training courses to qualify as "Osteologe DVO" and the "White Book Osteoporosis", which was initiated by BJD and IOF and developed by several German medical societies and patient organisations it is based on the German DVO guidelines providing an evidence-based and structured overview concerning all relevant aspects of osteoporosis and fragility fractures.

[Clinical outcome following robotic assisted versus conventional total hip arthroplasty: a controlled and prospective study of seventy-one patients]. / Klinisches Outcome nach Roboter-assistierter versus konventionell implantierter Hüftendoprothetik: Prospektive, kontrollierte Untersuchung von 71 Patienten.

AIM: Robotic assisted total hip arthroplasty remains controversial, since wider exposure of the proximal femur and placement of the leg in maximal hip adduction and external rotation using a rigid leg-holder apparatus may impair significantly the hip abductors. Consequently, it is the purpose of this study to analyse and report both clinical outcome and hip abductor function following robotic assisted versus conventional total hip arthroplasty. MATERIAL AND METHODS: 36 robotic-assisted (CASPAR, Orto-Maquet, Rastatt, Germany) and 35 conventional cementless total hip arthroplasties were followed on average for 18 months regarding incidence of complications, Harris hip score, the scoring system according to Merle d'Aubigné and Postel, hip abductor function (using a spring-balance), and incidence of Trendelenburg's sign (according to the Kuhfuss-classification). Statistical analysis was performed in case of continuous data using the t test and the Mann-Whitney test, respectively, and in case of categorical data using Fisher's exact test and the chi-squared test, respectively. The level of significance was set as p < 0.05. RESULTS: Average duration of surgery (CASPAR: 100.6 min; conventional: 51.5 min; p < 0.0001) as well as average loss of haemoglobin (CASPAR: 4.5 mg/dL; conventional: 3.3 mg/dL; p = 0.0002) differed significantly, whereas the incidence of complications (CASPAR: two dislocations, one sciatic paresis, one deep infection; conventional: one dislocation, two fissures), revision rate (CASPAR: 5.6 %; conventional: 2.9 %), and incidence of heterotopic ossifications (CASPAR: 30.6 %; conventional: 17.1 %) was comparable following both procedures (p > 0.05). Improvement of the Harris hip score also was comparable in both groups (CASPAR: 40.9 to 86.1 points; conventional: 39.5 to 88.0 points; p = 0.21), whereas improvement of the score according to Merle d'Aubigné and Postel was significantly greater following the manual procedure (CASPAR: 10.1 to 16.0 points; conventional: 8.3 to 16.6 points; p < 0.0001). Differences between the two groups were also significant regarding hip abductor function (CASPAR: 76.1 %; conventional: 93.8 % of the contralateral hip; p < 0.0001) and incidence of Trendelenburg's sign (CASPAR: 61.1 %; conventional: 25.7 %; p = 0.0014). CONCLUSION: The significant functional impairment following robotic assisted THA should be taken critically into consideration prior to initiating such procedure.

[Outcome assessment in total knee arthroplasty: is the clinical measurement of range of motion a reliable measurable outcome variable?]. / Outcome-Messung in der Knieendoprothetik: Ist die klinische Bestimmung der Gelenkbeweglichkeit eine zuverlässig messbare Ergebnisgrösse?

AIM: The aim of this clinical study was to investigate the reliability of the clinical assessment (visual and goniometric) of the range of motion of the knee joint. METHOD: 30 patients were assessed concerning the range of motion of their knee joints by visual and goniometric measurements. Assessment was performed by three investigators. The obtained data were used to analyse the intra- and interobserver reliability. Statistical analysis was performed using the Spearman coefficient of correlation [r (s)]. RESULTS: Intraobserver agreement was consistent across observers regarding the visual and goniometric assessment of flexion (r (s) > 0.6), whereas reliability was uniformly low for both measurements regarding the assessment of extension (r (s) < 0.6). Interobserver agreement was consistent across all three goniometric and two out of three visual assessments regarding the measurement of flexion (r (s) > 0.6); the interobserver reproducibility of extension, however, was uniformly low both for the visual and goniometric measurements (r (s) < 0.6). CONCLUSION: Reliability of clinical assessment of range of motion should be taken critically into consideration whilst performing classical function-related scoring systems when measuring outcome after total joint arthroplasty, since these scoring systems are strongly based on a valid and reliable assessment of range of motion.

[What influence doe the implant have on the perioperative morbidity following internal fixation of proximal femur fracture? Analysis of dynamic hip screw and proximal femoral nailing]. / Welchen Einfluss hat das Implantat auf die perioperative Morbidität bei osteosynthetischer Versorgung pertrochantärer Femurfrakturen? Analyse von dynamischer Hüftschraube und proximalem Femurnagel.

RATIONALE: Proximal femur fracture is a frequent finding in elderly patients. Both the dynamic hip screw (DHS) and the proximal femur nail (PFN) are established implants. The aim of our study was to assess the perioperative morbidity in a sample of 112 patients with proximal femur fracture, operated on with either DHS or PFN. MATERIAL AND METHODS: Data of 112 consecutive patients (59 DHS, 53 PFN), which consisted of 20 variables, were obtained. Nine variables were selected, which were considered to possess a potential impact on the complication rate. These variables were type of implant, sex, age, period between trauma and surgery, ASA classification, fracture classification of the ASIF, duration of surgery, blood loss, and antibiotics. They were transformed into dichotomous data to enable univariate statistical analysis and logistic regression. RESULTS: The ASA classification only was evaluated to have a predictive value as shown by the odds ratio of 2.23 (90 % confidence interval: 1.09 - 4.56). ASA 3 or 4 patients had an expected frequency, which was 2.2-fold increased as compared to patients classified as ASA 1 or 2, to suffer from perioperative complications. Using logistic regression, again the ASA classification only was shown to have a significant impact (p = 0.066, level of significance: p < 0.1) on the perioperative morbidity. CONCLUSION: As suggested by our results, neither the type of implant nor the other variables mentioned above had a significant impact on the resulting complication rate in our study sample. The ASA classification only was found to significantly increase the probability of an adverse event. This finding should be taken into account prior to initiating therapy.

[Reliability of transcutaneous measurement of oxygen tension on the lower leg]. / Reliabilität der transkutanen Sauerstoffpartialdruckmessung an der unteren Extremität.

AIM: Measurement of transcutaneous oxygen tension is increasingly used to determine the appropriate level of amputation in patients with vascular disease. The purpose of the present study was to analyze the intra- and interrater reliability of transcutaneous oxygen [tcpO (2)] measurements in a homogeneous study group. METHOD: Five investigators assessed the transcutaneous oxygen tension of both lower legs of seven persons in a fixed setting. Assessment was repeated with the same examiners and the same examinees after 24 hours. TcpO (2) was measured at the posterior aspect of the lower leg twenty centimeters below the knee joint line. The TCM 400 Monitoring System (Radiometer Medical AIS, Bronshoj, Denmark) was used. Statistical analysis of the intra- and interrater reliability was performed with the Spearman coefficient of correlation. RESULTS: An overall mean of 56.2 +/- 10.6 mmHg was found. For the first examination, a mean of 55.3 +/- 10.6 mmHg was observed, whereas for the second examination it was 57.0 +/- 10.5 mmHg. Analysis of intrarater reliability showed a coefficient of correlation of r (s) = 0.56 (p < 0.0001). For interrater reliability, we found coefficients of correlation ranging from r (s) = 0.20 (p = 0.20) to r (s) = 0.69 (p = 0.0004). CONCLUSION: Analysis of transcutaneous oxygen tension measurements performed by different investigators in a fixed setting revealed a non- homogeneous intra- and interrater reliability, which should be taken into account prior to initiating therapy.

[Analysis of validity and reliability of three radiographic classification systems for preoperative assessment of bone stock loss in revision total hip arthroplasty]. / Gültigkeit und Reproduzierbarkeit radiologischer Klassifikationskriterien des knöchernen Substanzdefekts vor Revisionshüftendoprothetik.

AIM: It was the purpose of this prospective study to analyze validity and reliability of three different radiographic classification systems, which are used to assess bone stock loss prior to revision total hip arthroplasty. METHOD: Investigation was performed using the classification systems according to 1) Paprosky et al., 2) Hungerford et al., and 3) the German Society of Orthopaedics and Traumatology (DGOT). Twenty-eight consecutive patients with diagnosis of aseptic failure of total hip arthroplasty were enrolled in the study. Interrater agreement was analyzed by evaluating the classifications preoperatively by three investigators with different level of clinical experience using a blinded observer technique. Validity was analyzed by comparison of preoperative radiographic findings (n = 3) and an intraoperative control by visualization and palpation (n = 1). Spearman coefficient of correlation (r(s)) was used to establish levels of agreement among multiple ordinal variables. RESULTS: Interrater reliability testing using paired comparison between the three investigators revealed non-homogeneous coefficients of correlation (r(s): Paprosky femur: 0.45 - 0.67, acetabulum: 0.38 - 0.63; Hungerford: 0.46 - 0.66; DGOT femur: 0.38 - 0.59, acetabulum: 0.42 - 0.76). Paired analysis of correlation between preoperative and intraoperative findings again showed non-homogeneous coefficients of correlation (r(s): Paprosky femur: 0.59 - 0.68, acetabulum: 0.39 - 0.70; Hungerford: 0.39 - 0.74; DGOT femur: 0.44 - 0.60, acetabulum: 0.36 - 0.76). In general, defects were grossly underestimated preoperatively. The level of experience did not influence the validity of measurements. CONCLUSION: Our results indicate that these classifications do not provide valid and reliable assessment of femoral and acetabular bone stock loss prior to revision total hip arthroplasty.

[Revision total hip arthroplasty: analysis of the predictive value of a radiographic classification system for assessment of bone stock loss]. / Revisionshüftendoprothetik: Untersuchung des prädiktiven Werts einer radiologischen Defektklassifikation.

AIM: The aim of this study was to evaluate the predictive value of a radiographic classification system concerning implant and bone graft in revision total hip arthroplasty. This classification is used to assess bone stock loss prior to surgery, thus hypothetically enabling an adequate choice of the implant and bone graft required. METHOD: 33 consecutive patients with the diagnosis of aseptic failure of total hip arthroplasty were included in the study. The investigation was performed using the classification system according to Saleh et al. The predictive value was analyzed by comparing the radiographically based recommendation concerning implant and bone graft and the intraoperative procedure according to a blinded observer technique. The Spearman coefficient of correlation (r (s)) was used to establish levels of agreement among multiple ordinal variables. RESULTS: Analysis of correlation between preoperative radiological estimations and intraoperative conclusions concerning implant and bone graft revealed coefficients of correlation (r (s)) of 0.53 (p < 0.01) for the acetabular and of 0.63 (p < 0.01) for the femoral classification. CONCLUSION: Our results indicate that the Saleh classification does not provide sufficient information for preoperative assessment of the revision implant and bone graft required concerning the acetabular side, whereas planning of the operative procedure regarding the femoral implant seems to be possible. These ambivalent findings should be taken into account prior to revision total hip arthroplasty.

[Revision total hip arthroplasty: how do metaphyseal onset, diaphyseal fill and a three-point-stem-fixation influence the postoperative subsidence of a revision straight-stem?]. / Revisionshüftendoprothetik: Wie beeinflussen der metaphysäre Prothesenaufsitz, der diaphysäre Formschluss und der 3-Punkte-Schaftkontakt das postoperative Sinterungsverhalten eines zementfreien Revisionsgeradschaftes?

AIM: It was the purpose of this study to determine the postoperative subsidence of a cementless hip revision stem in regard to the degree of metaphyseal onset, diaphyseal fit and a three-point contact of the stem in the femur. METHODS: Data of 50 revision total hip replacements using a cementless revision straight stem (PFM-R) could be investigated. The degree of subsidence was measured on pelvic X-rays 6 and 12 months postoperatively. The degree of metaphyseal onset, diaphyseal fit and a three-point contact of the stem in the femur was determined on the immediate postoperative X-rays. RESULTS: The amount of subsidence was strongly related to the degree of metaphyseal onset. With minor onset (up to 25 % of the possible) stems subsided 9.4 (6 months), respectively, 13.2 millimeters (12 months) in average within the investigation periods. If there was a large degree of metaphyseal onset (more than 75 % of the possible) the average subsidence was only 1.6 (6 months) or 0.9 millimeters, respectively (12 months). Neither the amount of diaphyseal fit nor the presence of three-point contact of the stem in the femur influenced the subsidence significantly. Conclusion The amount of the postoperative subsidence of stems in cementless revision total hip arthroplasty is predominantly influenced by the degree of the metaphyseal onset of the prosthesis.