Very early migration of a calcar-guided short stem: a randomized study of early mobilization and the influence of a calcium phosphate coating with 60 patients.

This study analyzed the migration of a calcar-guided short stem to determine the course of very early migration, as well as evaluated the effect of an additional calcium phosphate (CP) coating on a titanium plasma spray (TPS) coating, which has not been analyzed previously. Sixty patients were enrolled in this study and were treated with the A2 calcar-guided short stem. The implant coating was randomized with either the TPS or an additional CP coating, and radiostereometric analysis was performed with the baseline measurement before initial weight-bearing, along with follow-up examinations at 1 week, 6 weeks, 3 months, and 6 months. Implant migrations were 0.27 mm (standard deviation [SD], 0.13 mm) and 0.74 mm (SD, 1.11 mm) at 1 week and 6 months post-surgery, respectively, and 65% and 87% of the implants reached their final position 1 week and 6 weeks after surgery, respectively. After 6 weeks, 3 months, and 6 months, a significant increase was noted in the migration of the CP coating group vs. that of the TPS coating group. Upon the final observation at 6 months, the groups displayed on average a 0.74-mm migration. Most of the analyzed implants ceased migration within the first week post-surgery, but the CP coating demonstrated a higher and more prolonged migration compared to the TPS coating.

[Evaluation of care for slipped capital femoral epiphysis (SCFE) in Germany]. / Analyse der Versorgungssituation bei Epiphyseolysis capitis femoris (ECF) in Deutschland.

INTRODUCTION: The treatment concept for slipped capital femoral epiphysis is still controversial. According to studies, there is currently no recommendation for a universal approach. Therefore, the aim of this study is to analyze the care reality of children with ECF in Germany. METHODS: The evaluation of the study is performed based on a questionnaire sent to physicians tending to ECF in 2021. Data is compared to the literature. RESULTS: 36 of 47 questionnaires sent out were included. Overall, no significant difference in ECF care was proven in terms of annual caseload or the size of hospital. CONCLUSION: A high variance in operative SCFE treatment is reported. According to current literature, the modified Dunn procedure is considered the best therapeutic option to date, especially for patients with severe or chronic ECF. However, compared with alternative care options, this is not feasible in every hospital due to its complicating and challenging nature. Central registration, minimum volume regulation, and expansion of continuing education measures can contribute to optimization.

Correction to: Biodegradable magnesium-based screw clinically equivalent to titanium screw in hallux valgus surgery: short term results of the first prospective, randomized, controlled clinical pilot study.

An amendment to this paper has been published and can be accessed via the original article.

Outcomes of Noninvasively Treated Idiopathic Toe Walkers.

Idiopathic toe walking (ITW) causes a common problem in pediatric orthopaedics. In the literature, numerous treatment options have been reported, but consensus about the management of ITW is still missing. The aim of the current study was to evaluate conservative treatment with pyramidal insoles. A total of 193 patients underwent conservative treatment between January 2010 and June 2013. Mean age at the beginning of the treatment was 7.75 ± 0.23 years (range 2.0-17.0 years). For all patients, demographic data, comorbid diseases, passive range of motion (ROM), persistent toe walking, and performed operations were retrospectively evaluated. Following operative treatment was defined failure. Eight (4.15%) patients underwent Achilles tendon lengthening operation after mean therapy time of 2.72 years (range 0.1-7.0 years), 174 cases were treated successfully (90.16%). In 50 cases, toe walking suspended completely after mean therapy time of 2.83 years. In cases of failure, patients were older at diagnosis and at the beginning of the treatment. Mean passive ROM increased over the time. In cases of failure, ROM decreased from the first to the second examination. Conservative treatment of ITW using pyramidal insoles can be effective. Ankle dorsiflexion significantly improved in the patients who were successfully treated. Therapy should start early. A decrease of ROM under therapy should lead to critical revisal of individual therapy. Levels of Evidence: Therapeutic, level IV: Case series.

Results of HemiCAP® Implantation as a Salvage Procedure for Osteochondral Lesions of the Talus.

Osteochondral defects (OCDs) of the talus remain a surgical challenge, especially after failed primary treatment. The aim of the present study was to examine the clinical outcomes after HemiCAP® implantation for OCDs of the medial talar dome after failed previous surgery. Our retrospective study included 11 patients, who had undergone surgery from June 2009 to September 2012 for an OCD of the medial talar dome and received a HemiCAP® on the talus after failed previous surgery for OCD. The data were acquired using patients' medical records and standardized questionnaires, including the Foot and Ankle Outcome Score (FAOS), University of California at Los Angeles (UCLA) activity score, EQ-5D, numerical rating scale (NRS), and Short-Form 36-item Health Survey (SF-36). Using these scores, the possibility of returning to work and sports was determined. Any complications and the need for revision surgery were recorded. One patient refused to participate in the study, leaving 10 patients for evaluation. The mean age was 47.64 ± 10.97 years. The mean follow-up period was 43.5 ± 35.51 months. The FAOS and SF-36 subscale scores and the EQ-5D and UCLA activity scores did not improve significantly (p < .05). The mean postoperative pain score on the NRS improved significantly from 6.6 ± 1.77 preoperatively to 5.1 ± 2.02 postoperatively (p < .05). A greater body mass index led to worse postoperative outcomes with higher scores on the pain-NRS and less satisfaction (p < .05). Ten revisions for ongoing pain were performed in 7 patients (70.0%) within a mean of 28.4 ± 13.35 months of the initial procedure, and 6 patients (60%) indicated they would undergo surgery again. The results of the present study have shown that implantation of the HemiCAP® as a salvage procedure for OCDs of the talus is challenging and does not consistently lead to good clinical results. Also, overweight patients appear to have an increased risk of postoperative dissatisfaction and persistent ankle pain.

Hip and knee effects after implantation of a drop foot stimulator.

BACKGROUND: An active ankle dorsiflexion is essential for a proper gait pattern. If there is a failure of the foot lifting, considerable impairments occur. The therapeutic effect of an implantable peroneus nerve stimulator (iPNS) for the ankle dorsiflexion is already approved by recent studies. However, possible affection for knee and hip motion after implantation of an iPNS is not well described. OBJECTIVE: The objective of this retrospective study was to examine with a patient cohort whether the use of iPNS induces a lower-extremity flexion withdrawal response in the form of an increased knee and hip flexion during swing phase. METHODS: Eighteen subjects (12 m/6 w) treated with an iPNS (ActiGait®, Otto Bock, Duderstadt, Germany) were examined in knee and hip motion by gait analysis with motion capture system (Vicon Motion System Ltd®, Oxford, UK) and Plug-in-Gait model after a mean follow up from 12.5 months. The data were evaluated and compared in activated and deactivated iPNS. RESULTS: Only little changes could be documented, as a slight average improvement in peak knee flexion during stand phase from 1.0° to 2.5° and peak hip flexion in stance from 3.1° to 2.1° In contrast, peak knee flexion during swing appeared similar (25.3° to 25.7°) same as peak hip flexion during swing. In comparison with the healthy extremity, a more symmetric course of the knee flexion during stand phase could be shown. CONCLUSIONS: No statistical significant improvements or changes in hip and knee joint could be shown in this study. Only a more symmetric knee flexion during stand phase and a less hip flexion during stand phase might be hints for a positive affection of iPNS for knee and hip joint. It seems that the positive effect of iPNS is only based on the improvement in ankle dorsiflexion according to the recent literature.

Early results using a biodegradable magnesium screw for modified chevron osteotomies.

This is the first larger study analyzing the use of magnesium-based screws for fixation of modified Chevron osteotomies in hallux valgus surgery. Forty-four patients (45 feet) were included in this prospective study. A modified Chevron osteotomy was performed on every patient and a magnesium screw used for fixation. The mean clinical follow up was 21.4 weeks. The mean age of the patients was 45.5 years. Forty patients could be provided with the implant, in four patients the surgeon decided to change to a standard metallic implant. The AOFAS, FAAM and pain NRS-scale improved markedly. The hallux valgus angle, intermetatarsal angle and sesamoid position improved significantly. Seven patients showed dorsal subluxation, rotation or medial shifting of the metatarsal heads within the first 3 months. One of these patients was revised, in all others the findings were considered clinically not significant or the patients refused revision. This study shows the feasibility of using magnesium screws in hallux valgus-surgery. Surgeons starting with the use of these implants should be aware of the proper handling of these implants and should know about corrosion effects during healing and its radiographic appearance. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:2207-2214, 2016.

Analysis of migration of the Nanos® short-stem hip implant within two years after surgery.

PURPOSE: Short-stem implants provide a bone-preserving alternative in total hip arthroplasty. However, some evidence exists that the smaller implant-bone contact surface may compromise primary stability and impair osseo-integration. The purpose of this study was to analyse the migration characteristics of the Nanos® short stem over two years by means of model-based roentgen stereophotogrammetric analysis (MBRSA). METHODS: Eighteen patients aged 53.6 ± 7.2 years were included. After being treated with a Nanos implant, 14 patients were followed-up radiologically at three, six, 12 and 24 months by means of MBRSA. Early implant migration was calculated. Clinical data have been assessed in addition. RESULTS: Highest translational migration was observed with a mean value of -0.22 ± 0.39 mm along the proximo-distal axis after three months and highest rotational migration with 0.8 ± 3.2° also around the y-axis after two years. The resulting total migration was 0.46 ± 0.31 mm, with the largest proportion occurring within three months after surgery (0.40 ± 0.34 mm). CONCLUSION: The Nanos short-stem hip implant shows only a slight initial migration within three months after implantation, followed by secondary stabilisation. These results suggest both good primary stability and osseo-integration, suggesting a low risk of aseptic loosening.

Outcomes with cementless total hip resurfacing: 5 year follow-up.

BACKGROUND: Resurfacing Arthroplasty (RA) of the hip has undergone resurgence with initially mainly good clinical results in young patients. It was mainly performed in younger more active patients with severe symptomatic arthritis of the hip including pelvic deformity. Furthermore the proximal femoral anatomy was preserved for surgical procedures in the future. OBJECTIVE: The aim of the study was to perform a prospective review of the very first 85 hips that had implantation of one cementless resurfacing system and a mean follow up of 5 years. METHODS: 85 cementless Total Hip Resurfacing devices have been performed in 75 patients in our orthopaedic department. The mean age of the study group was 49.8 years. Harries Hip Score, clinical examination data and radiographic parameters including the neck shaft angle (NSA), stem shaft angle (SSA) and detection of radiolucencies were analyzed. RESULTS: Estimated implant survival at five years of follow-up was 88.2% at 5 years follow-up using revision for all causes as the end point. Mean HHS was 92.5 (range 80-100) five years after Resurfacing Arthroplasty. CONCLUSIONS: In conclusion we have to admit, that there was a high proportion of failed hip resurfacings but in the proportion that succeeded we saw good clinical results.

Biodegradable magnesium-based screw clinically equivalent to titanium screw in hallux valgus surgery: short term results of the first prospective, randomized, controlled clinical pilot study.

PURPOSE: Nondegradable steel-and titanium-based implants are commonly used in orthopedic surgery. Although they provide maximal stability, they are also associated with interference on imaging modalities, may induce stress shielding, and additional explantation procedures may be necessary. Alternatively, degradable polymer implants are mechanically weaker and induce foreign body reactions. Degradable magnesium-based stents are currently being investigated in clinical trials for use in cardiovascular medicine. The magnesium alloy MgYREZr demonstrates good biocompatibility and osteoconductive properties. The aim of this prospective, randomized, clinical pilot trial was to determine if magnesium-based MgYREZr screws are equivalent to standard titanium screws for fixation during chevron osteotomy in patients with a mild hallux valgus. METHODS: Patients (n=26) were randomly assigned to undergo osteosynthesis using either titanium or degradable magnesium-based implants of the same design. The 6 month follow-up period included clinical, laboratory, and radiographic assessments. RESULTS: No significant differences were found in terms of the American Orthopaedic Foot and Ankle Society (AOFAS) score for hallux, visual analog scale for pain assessment, or range of motion (ROM) of the first metatarsophalangeal joint (MTPJ). No foreign body reactions, osteolysis, or systemic inflammatory reactions were detected. The groups were not significantly different in terms of radiographic or laboratory results. CONCLUSION: The radiographic and clinical results of this prospective controlled study demonstrate that degradable magnesium-based screws are equivalent to titanium screws for the treatment of mild hallux valgus deformities.

Effect of limb rotation on radiographic alignment in total knee arthroplasties.

INTRODUCTION: Even in a well-aligned total knee arthroplasty (TKA), limb rotation at the time of radiographic assessment will alter the measurement of alignment. This could influence the radiographic outcome of TKA. The purpose of this study was to evaluate the effect of limb rotation on radiographic alignment after TKA and to establish a re-calculation of this rotation by using existing radiographic landmarks. MATERIALS AND METHODS: Synthetic femur and tibia (Sawbones), Inc. Vashon Island, WA) were used to create a TKA of the Triathlon knee prosthesis system (Stryker), Limerick, Ireland). The femoral alignment was 6.5 degrees valgus. The model was fixed in an upright stand. Five series of nine anteroposterior (AP) long leg radiographs were taken on a 30 cm x 120 cm plates in full extension with the limb rotated, in 5 degrees increments, from 20 degrees external rotation to 20 degrees internal rotation. After digitizing each radiograph (Scanner Hewlett Packard XJ 527), an observer measured the anatomic mechanical angle of the femur [AMA ( degrees )], the mechanical lateral proximal femur angle [mLPFA ( degrees )], the mechanical lateral distal femur angle [mLDFA ( degrees )], the mechanical medial proximal tibia angle [mMPTA ( degrees )] and the mechanical lateral distal tibia angle [mLDTA ( degrees )] using a digital measurement software (MediCAD, Hectec, Altfraunhofen, Germany). Besides, the observer measured the geometrical distances of the femoral component figured on the long leg radiograph. A ratio of one distance to another was measured (called femoral component distance ratio). RESULTS: The average radiographic anatomic alignment ranged from 6.827 degrees AMA (SD = 0.22 degrees ) in 20 degrees internal rotation to 4.627 degrees AMA (SD = 0.22 degrees ) in 20 degrees external rotation. Average mLPFA ( degrees ) ranged from 101.63 degrees (SD = 0.63) in 20 degrees internal rotation to 93.60 degrees (SD = 0.74 degrees ) in 20 degrees external rotation. Average mLDFA ( degrees ) ranged from 90.59 degrees (SD = 3.01 degrees ) in 20 degrees internal rotation to 86.76 degrees (SD = 0.36 degrees ) in 20 degrees external rotation. Average mMPTA ( degrees ) ranged from 90.35 degrees (SD = 0.81 degrees ) in 20 degrees internal rotation to 88.49 degrees (SD = 0.52 degrees ) in 20 degrees external rotation. Average mLDTA ( degrees ) ranged from 98.89 degrees (SD = 2.3 degrees ) in 20 degrees internal rotation to 90.53 degrees (SD = 3.39 degrees ) in 20 degrees external rotation. Without an application of limb rotation, the femoral component distance ratio was measured to be 0.89 (SD = 0.01), in 20 degrees internal rotation 0.63 (SD = 0.01) and in 20 degrees external rotation 1.16 (SD = 0.01). DISCUSSION: Limb rotation had a highly statistically significant effect on measured anatomic alignment and mechanical angles. A correlation between limb rotation, anatomic mechanical angle, mechanical angles measured at femur and tibia and the femoral component distance ratio was established. As the anatomic mechanical angle and the femoral component distance ratio change linearly in the range of 20 degrees internal and external limb rotation, a calculation of the femoral component distance ratio could be used to re-calculate the limb rotation at the time of radiographic assessment to evaluate the evidence of a long leg radiograph.