Felix Greimel

Total hip replacement in developmental dysplasia using an oval-shaped cementless press-fit cup

PurposeAcetabular roof deficiency due to subluxation of the femoral head (Hartofilakidis type II) increases the complexity of total hip arthroplasty. In these cases some form of support is usually required, to reach stable fixation of the acetabular component. Pursuing this aim, the oval-shaped cementless cranial socket could be an alternative to conventional treatment options.MethodsBetween 1998 and 2008, 37 patients (40 hips) underwent primary total hip arthroplasty using the cranial socket (mean follow-up 5.6 years, range 26 to 133 months). In a retrospective study we compared these clinical and radiological results with the results of a matched control group consisting of 35 patients (40 hips) treated with a standard cementless hemispherical cup in combination with bulk femoral autografting (mean follow-up 6.9 years, range 30 to 151 months).ResultsThere were no statistically significant differences in the HHS (p = 0.205) or the SF-36 (p = 0.26) between both groups. There was no prosthesis failure due to septic or aseptic loosening. Time of surgery was significantly shorter in the cranial socket group (p < 0.001). The acetabular component could be placed in the ideal rotational hip centre in 24 (60%) hips in the cranial socket group and 32 (80%) hips in the control group, respectively.ConclusionsOur study indicates, that the cranial socket can be an alternative treatment option for the reconstruction of acetabular deficiency in osteoarthritis secondary to developmental dysplasia.

Presence of rotational errors in long leg radiographs after total knee arthroplasty and impact on measured lower limb and component alignment

PurposeRotation of the lower limb in weight bearing long leg radiographs has a great impact on measured component and lower limb alignment parameters. We asked which rotational errors of long leg radiographs are present in a high volume centre and which radiological and clinical consequences arise regarding measured coronal component and lower limb alignment after total knee arthroplasty.MethodsIn 100 long leg radiographs coronal femoral and tibial component alignment and hip knee ankle angle (HKA) were measured. Present rotational errors in long leg radiographs were determined by fibular overlap and its impact on alignment parameters calculated.ResultsA mean internal rotation of 8.1° (9.3 SD) with a range between 36° of internal and 16° of external rotation was found in long leg radiographs. This resulted in mean differences between measurements before and after rotational correction regarding femoral and tibial component alignment and HKA of 0.6–0.8° (range 3.5° valgus and 1.6° varus error). Clinically, 11 out of 100 patients were wrongly assigned to either mal- or well-alignment (neutral mechanical alignment within ±3° varus or valgus).ConclusionSurgeons should be aware of potential rotational errors in long leg radiographs after total knee arthroplasty resulting in wrong measurements. In case of rotational errors, radiographs should be repeated or rotational corrections calculated. For study purposes only radiographs after rotational correction should be accepted.

Can Consistent Benchmarking within a Standardized Pain Management Concept Decrease Postoperative Pain after Total Hip Arthroplasty? A Prospective Cohort Study including 367 Patients

Background The number of total hip replacement surgeries has steadily increased over recent years. Reduction in postoperative pain increases patient satisfaction and enables better mobilization. Thus, pain management needs to be continuously improved. Problems are often caused not only by medical issues but also by organization and hospital structure. The present study shows how the quality of pain management can be increased by implementing a standardized pain concept and simple, consistent, benchmarking. Methods All patients included in the study had undergone total hip arthroplasty (THA). Outcome parameters were analyzed 24 hours after surgery by means of the questionnaires from the German-wide project “Quality Improvement in Postoperative Pain Management” (QUIPS). A pain nurse interviewed patients and continuously assessed outcome quality parameters. A multidisciplinary team of anesthetists, orthopedic surgeons, and nurses implemented a regular procedure of data analysis and internal benchmarking. The health care team was informed of any results, and suggested improvements. Every staff member involved in pain management participated in educational lessons, and a special pain nurse was trained in each ward. Results From 2014 to 2015, 367 patients were included. The mean maximal pain score 24 hours after surgery was 4.0 (±3.0) on an 11-point numeric rating scale, and patient satisfaction was 9.0 (±1.2). Over time, the maximum pain score decreased (mean 3.0, ±2.0), whereas patient satisfaction significantly increased (mean 9.8, ±0.4; p<0.05). Among 49 anonymized hospitals, our clinic stayed on first rank in terms of lowest maximum pain and patient satisfaction over the period. Conclusion Results were already acceptable at the beginning of benchmarking a standardized pain management concept. But regular benchmarking, implementation of feedback mechanisms, and staff education made the pain management concept even more successful. Multidisciplinary teamwork and flexibility in adapting processes seem to be highly important for successful pain management.

Efficacy of antibiotic treatment of implant-associated Staphylococcus aureus infections with moxifloxacin, flucloxacillin, rifampin, and combination therapy: an animal study

The efficacy of antibiotic monotherapy and combination therapy in the treatment of implant-associated infection by Staphylococcus aureus was evaluated in an animal study. The femoral medullary cavity of 66 male Wistar rats was contaminated with S. aureus (ATCC 29213) and a metal device was implanted, of which 61 could be evaluated. Six treatment groups were studied: flucloxacillin, flucloxacillin in combination with rifampin, moxifloxacin, moxifloxacin in combination with rifampin, rifampin, and a control group with aqua. The treatment was applied for 14 days. After euthanasia, the bacterial counts in the periprosthetic bone, the soft tissue, and the implant-associated biofilm were measured. Both antibiotic combination treatments (moxifloxacin plus rifampin and flucloxacillin plus rifampin) achieved a highly significant decrease in microbial counts in the bone and soft tissue and in the biofilm. Mono-antibiotic treatments with either moxifloxacin or flucloxacillin were unable to achieve a significant decrease in microbial counts in bone and soft tissue or the biofilm, whilst rifampin was able to reduce the counts significantly only in the biofilm. Antibiotic resistance was measured in 1/3 of the cases in the rifampin group, whereas no resistance was measured in all other groups. The results show that combinations of both moxifloxacin and flucloxacillin plus rifampin are adequate for the treatment of periprosthetic infections due to infections with S. aureus, whereas monotherapies are not effective or not applicable due to the rapid development of antibiotic resistance. Therefore, moxifloxacin is an effective alternative in combination with rifampin for the treatment of implant-associated infections.

Implementing a benchmarking and feedback concept decreases postoperative pain after total knee arthroplasty: A prospective study including 256 patients

Perioperative pain reduction, particularly during the first two days, is highly important for patients after total knee arthroplasty (TKA). Problems are not only caused by medical issues but by organization and hospital structure. The present study shows how the quality of pain management can be increased by implementing a standardized pain concept and simple, consistent benchmarking. All patients included into the study had undergone total knee arthroplasty. Outcome parameters were analyzed by means of a questionnaire on the first postoperative day. A multidisciplinary team implemented a regular procedure of data analyzes and external benchmarking by participating in a nationwide quality improvement project. At the beginning of the study, our hospital ranked 16th in terms of activity-related pain and 9th in patient satisfaction among 47 anonymized hospitals participating in the benchmarking project. At the end of the study, we had improved to 1st activity-related pain and to 2nd in patient satisfaction. Although benchmarking started and finished with the same standardized pain management concept, results were initially pure. Beside pharmacological treatment, interdisciplinary teamwork and benchmarking with direct feedback mechanisms are also very important for decreasing postoperative pain and for increasing patient satisfaction after TKA.

Multicenter cohort-study of 15326 cases analyzing patient satisfaction and perioperative pain management: general, regional and combination anesthesia in knee arthroplasty

Numbers of knee replacement surgeries have been rising over the past years. After having ameliorated operation techniques and material, pain management and anesthetic methods have come into focus. All 15326 patients included had undergone primary knee arthroplasty within this multicenter cohort-study, conducted in 46 orthopedic departments. Parameters were evaluated on first postoperative day. Primary outcome values were pain levels (activity, minimum and maximum pain, and pain management satisfaction). Pain medication necessity was analyzed. Parameters were compared between the types of anesthesia used: general, regional and combination anesthesia. Pain scores and pain management satisfaction were significantly better in the groups of either spinal or peripheral anesthesia combined with general anesthesia (p < 0.001, respectively). Patients who received the combination of general and spinal anesthesia were associated with the lowest need for opioids (p < 0.001). The use of a combined general and spinal anesthesia as well as using a combination of general and peripheral anesthesia in knee arthroplasty was associated with a highly significant advantage to other anesthetic techniques regarding perioperative pain management in daily clinical practice, but maybe below clinical relevance. Furthermore they were associated with positive tendency considering side effects and subjective well-being parameters.

Effectiveness of a multimodal pain management concept for patients with cervical radiculopathy with focus on cervical epidural injections

Cervical radiculopathy has become an increasing problem worldwide. Conservative treatment options have been recommended in many reviews on cervical radiculopathy, ranging from different types of physiotherapy to waiting for remission by natural history. No multimodal pain management concept (MPM) on an inpatient basis has been evaluated. This study aimed at showing the positive short-term effects of an inpatient multimodal pain management concept with focus on cervical translaminar epidural steroid injection for patients with cervical radiculopathy. 54 patients who had undergone inpatient MPM for 10 days were evaluated before and after 10-days treatment. The NRS (0–10) value for arm pain could be reduced from 6.0 (IQR 5.7–6.8) to 2.25 (IQR 2.0–3.1) and from 5.9 (IQR 4.8–6.0) to 2.0 (IQR 1.7–2.6) for neck pain. Neck pain was reduced by 57.4% and arm pain by 62.5%. 2 days after epidural steroid injection, pain was reduced by 40.1% in the neck and by 43.4% in the arms. MPM seems to be an efficient short-term approach to treating cervical radiculopathy. Cervical translaminar epidural steroid injection is an important part of this concept. In the absence of a clear indication for surgery, MPM represents a treatment option.

Kinematic component alignment in total knee arthroplasty leads to better restoration of natural tibiofemoral kinematics compared to mechanic alignment

PurposeKinematically aligned total knee arthroplasty is associated with superior pain relief, increased flexion and a more normal feeling knee. It was hypothesized that due to restoring the knee’s natural anatomy, kinematically aligned knees show more physiological tibiofemoral kinematics than mechanically aligned knees.MethodsInvestigations were performed in nine healthy cadaveric knees of whole bodies fixed by the Thiel method. Tibiofemoral kinematics of healthy knees and after kinematically and mechanically aligned total knee arthroplasty were assessed between 0° and 90° of flexion by a navigational device.ResultsRegarding tibial internal rotation or femoral roll back, respectively, kinematically aligned total knee arthroplasties showed no significant differences between 0° and 70° of flexion in comparison to knees before total knee arthroplasty. In contrast, mechanically aligned total knee arthroplasties showed significant changes between 10° and 90° of flexion. Kinematically aligned knees showed a significant changed abduction/adduction between 20° and 70° of flexion, mechanically aligned knees within 20° and 90° of flexion.ConclusionIn the present study setting kinematically aligned total knee arthroplasties showed more natural and physiological tibiofemoral kinematic pattern with regard to tibial internal rotation or femoral rollback, respectively, and tibial adduction than mechanically aligned total knee arthroplasties. While these results may support promising early clinical results of kinematical alignment proposing a better function, long-term results especially implant survival need to be awaited.

Rotation of intramedullary alignment rods affects distal femoral cutting plane in total knee arthroplasty

PurposeIntramedullary rods are widely used to align the distal femoral cut in total knee arthroplasty. We hypothesised that both coronal (varus/valgus) and sagittal (extension/flexion) cutting plane are affected by rotational changes of intramedullary femoral alignment guides.MethodsDistal femoral cuts using intramedullary alignment rods were simulated by means of a computer-aided engineering software in 4°, 6°, 8°, 10°, and 12° of valgus in relation to the femoral anatomical axis and 4° extension, neutral, as well as 4°, 8°, and 12° of flexion in relation to the femoral mechanical axis. This reflects the different angles between anatomical and mechanical axis in coronal and sagittal planes. To assess the influence of rotation of the alignment guide on the effective distal femoral cutting plane, all combinations were simulated with the rod gradually aligned from 40° of external to 40° of internal rotation.ResultsRotational changes of the distal femoral alignment guides affect both the coronal and sagittal cutting planes. When alignment rods are intruded neutrally with regards to sagittal alignment, external rotation causes flexion, while internal rotation causes extension of the sagittal cutting plane. Simultaneously the coronal effect (valgus) decreases resulting in an increased varus of the cutting plane. However, when alignment rods are intruded in extension or flexion partly contradictory effects are observed. Generally the effect increases with the degree of valgus preset, rotation and flexion.ConclusionAs incorrect rotation of intramedullary alignment guides for distal femoral cuts causes significant cutting errors, exact rotational alignment is crucial. Coronal cutting errors in the distal femoral plane might result in overall leg malalignment, asymmetric extension gaps and subsequent sagittal cutting errors.

Revision Surgery in Total Joint Replacement Is Cost-Intensive

Revisions after total joint replacement increase constantly. In the current study, we analyzed clinical outcome, complication rates, and cost-effectiveness of revision arthroplasty. In a retrospective analysis of 162 revision hip and knee arthroplasties from our institutional joint registry responder rate, patient-reported outcome measures (EQ-5D, WOMAC), complication rates, and patient-individual charges in relation to reimbursement were compared with a matched control group of primary total joint replacements. Positive responder rate one year postoperatively was lower for revision arthroplasties with 72.9% than for primary arthroplasties with 90.1% (OR=0.30, 95%CI=0.18–0.59, p=0.001). Correspondingly, improvement in patient-reported outcome measures one year after surgery was lower in revision than in primary joint arthroplasty with EQ-5D 0.19±0.25 to 0.30±0.24 (p<0.001) and WOMAC 24.3±30.3 to 41.2±21.3 (p<0.001). Infection rate was higher in revision (6.8%) compared to primary replacements (0%, p=0.001). Mean charges in revision arthroplasty were 76.0% higher than in matched primary joint replacements (7110.8±2249.4