The PJI-TNM classification for periprosthetic joint infections.

Aims: This study aimed to evaluate the clinical application of the PJI-TNM classification for periprosthetic joint infection (PJI) by determining intraobserver and interobserver reliability. To facilitate its use in clinical practice, an educational app was subsequently developed and evaluated. Methods: A total of ten orthopaedic surgeons classified 20 cases of PJI based on the PJI-TNM classification. Subsequently, the classification was re-evaluated using the PJI-TNM app. Classification accuracy was calculated separately for each subcategory (reinfection, tissue and implant condition, non-human cells, and morbidity of the patient). Fleiss' kappa and Cohen's kappa were calculated for interobserver and intraobserver reliability, respectively. Results: Overall, interobserver and intraobserver agreements were substantial across the 20 classified cases. Analyses for the variable 'reinfection' revealed an almost perfect interobserver and intraobserver agreement with a classification accuracy of 94.8%. The category 'tissue and implant conditions' showed moderate interobserver and substantial intraobserver reliability, while the classification accuracy was 70.8%. For 'non-human cells,' accuracy was 81.0% and interobserver agreement was moderate with an almost perfect intraobserver reliability. The classification accuracy of the variable 'morbidity of the patient' reached 73.5% with a moderate interobserver agreement, whereas the intraobserver agreement was substantial. The application of the app yielded comparable results across all subgroups. Conclusion: The PJI-TNM classification system captures the heterogeneity of PJI and can be applied with substantial inter- and intraobserver reliability. The PJI-TNM educational app aims to facilitate application in clinical practice. A major limitation was the correct assessment of the implant situation. To eliminate this, a re-evaluation according to intraoperative findings is strongly recommended.

[Navigated or conventional acetabular surgery : Comparison of positional accuracy exemplified by the infra-acetabular screw]. / Navigiert oder konventionell in der Acetabulumchirurgie : Vergleich der Positionsgenauigkeit am Beispiel der infraazetabulären Schraube.

BACKGROUND: The principle of joint-preserving treatment of acetabular fractures is the anatomic reduction of joint-bearing elements and internal osteosynthesis. For stabilization of the anterior and posterior columns against each other, the infra-acetabular screw (IAS) is regularly used in the clinical routine. OBJECTIVE: The aim of this study was to compare the position of the IAS in the infra-acetabular corridor after navigated placement and after freehand placement. MATERIAL AND METHOD: The position of the screw was evaluated in 42 patients using multiplanar reconstructions. The screw was placed freehand in 30 patients and using image-guided navigation in 12 patients. In addition to measurement of the position of the screw, demographic data, operating time, radiation exposure and blood loss were recorded. RESULTS: The vast majority of the patients were male (86%), the median age was 67 years and the median body mass index (BMI) was 25 kg/m2. The median operating time was 166 min and the median blood loss was 900 ml. The adjusted values in the whole sample considering the position of the screw were: distance of screw to cartilage mean value (m) = 3.8 mm, distance of screw to corridor center m = 3.5 mm and angle of screw to corridor m = 1.4°. There were no differences between the groups in the demographic parameters and the accuracy of positioning of the screw (p-value > 0.05). There was a longer irradiation time and a higher radiation dose in the navigated group compared to the group without navigation (p-value < 0.001). CONCLUSION: With appropriate experience both procedures are comparable taking into account the accuracy. Taking into consideration other perioperative parameters, such as radiation exposure and planned operating time, patient-related factors should be taken into consideration.

Treatment of Fracture-Related Infection after Pelvic Fracture.

BACKGROUND: The management of pelvic fractures is a significant challenge. Surgical site infection can result in the need for revision surgery, cause functional impairment, and lead to a prolonged length of stay and increased treatment costs. Although reports on fracture-related infection (FRI) after pelvic fracture fixation are sparsely reported in the literature, it is a serious complication. This study analysed patients with FRIs after pelvic fracture regarding patient characteristics, treatment strategies, and an evaluation of risk factors for FRI. METHODS: In this retrospective single-centre study, FRI was diagnosed based on clinical symptoms of infection and a positive culture of a bacterial infection. Depending on the severity and acuteness of the infection, osseous stabilization was restored either via implant retention (stable implant, no osteolysis), exchange (loose implant or bony defect), or external fixation (recurrence of infection after prior implant retaining revision). Healing of infection was defined as no sign of recurring infection upon clinical, radiological, and laboratory examination in the last follow-up visit. RESULTS: The FRI rate in our patient population was 7.5% (24/316). In 8/24 patients, the FRI occurred within the first three weeks after initial surgery (early) and 16/24 presented with a late onset of symptoms of FRI. A strategy of debridement, antibiotics, and implant retention (DAIR) was successful in 9/24 patients with FRI after pelvic fracture. A total of 10 patients required an exchange of osteo-synthetic implants, whereof three were exchanged to an external fixator. In five patients, we removed the implant because the fracture had already consolidated at the time of revision for infection. A total of 17/24 patients had a poly-microbial infection after a pelvic fracture and 3/24 patients died from post-traumatic multi-organ failure within the first 6 months after trauma. There were no cases of persistent infection within the remaining 21 patients. CONCLUSIONS: Although poly-microbial infection is common in FRI after pelvic fracture, the recurrence rate of infection is relatively low. A complex pelvic trauma with significant soft tissue injury is a risk factor for recurrent infection and multiple revisions. A strategy of DAIR can be successful in patients with a stable implant. In cases with recurrent infection or an unstable fracture site, the exchange of implants should be considered.

Bony Sacral Volume after Sacro-Iliac Screw Fixation of Pelvic Fractures Is Dependent on Reduction of the Anterior Pelvic Ring.

Pelvic ring injuries are uncommon but serious injuries. Percutaneous sacro-iliac screw fixation (SSF) is the standard treatment for posterior stabilization of pelvic fractures. Compression forces of the SSF might cause deformity of the sacrum and the pelvic ring. The aim of this radio-volumetric study is to evaluate the morphometry of the sacrum and pelvic ring in SSF for posterior pelvic fractures. (1) Methods: We conducted a radio-volumetric study measuring the bony sacral volume before and after SSF for a pelvic fracture based on a three-dimensional reconstruction of the pre- and postoperative computed tomography scan of 19 patients with a C-type pelvic fracture. In addition to the bony sacral volume, we assessed the pelvic deformity and the load bearing axis. We compared the results of patients without anterior stabilization (Group A) to patients who had additional ORIF of the anterior pelvic ring. (2) Results: Median age of the patients was 41.2 years (±17.8). All patients received percutaneous SSF with partially threaded 7.3 mm screws. The sacral volume decreased from 202.9 to 194.3 cm3 in group A (non-operative treatment anterior, n = 10) and an increase of sacral volume from 229.8 to 250.4 cm3 in group B (anterior ORIF; n = 9). Evaluation of the pelvic deformity also reflected this trend by a decrease of the ipsilateral load-bearing angle in group A (37.0° to 36.4°) and an increase of this angle in group B (36.3 to 39.9°). (3) Conclusions: Bony sacral volume and pelvic deformity after sacro-iliac screw fixation in pelvic fractures depend on treatment of the anterior pelvic ring. Reduction and fixation of the anterior fracture shows an increase of the bony sacral volume and the load bearing angle leading to a closer to normal reconstruction of the pelvic anatomy.

Epidemiology and injury morphology of traumatic hip dislocations in children and adolescents in Germany: a multi-centre study.

OBJECTIVE: Traumatic hip dislocations are very rare in childhood and adolescence. The aim of this multi-centre study is to analyse the current epidemiology and injury morphology of a large number of traumatic hip dislocations in children. This can provide a better understanding of childhood hip dislocations and contribute to the development of a therapeutic approach in order to prevent long-term impacts. METHODOLOGY: This retrospective, anonymised multi-centre study included patients, aged up to 17 years, with acute traumatic hip dislocations and open growth plates. The patients came from 16 German hospitals. Exclusion criteria included insufficient data, a positive history of hip dysplasia, or an association with syndromal, neurological or connective tissue diseases predisposing to hip dislocation. An analysis was carried out on the patients' anthropometric data and scans (X-ray, MRI, CT), which were collected between 1979 and 2021. Gender, age at the time of dislocation, associated fractures, mechanism of injury, initial treatment including time between dislocation and reduction, method of reduction, treatment algorithm following reduction and all documented complications and concomitant injuries were evaluated. RESULTS: Seventy-six patients met the inclusion criteria. There were two age peaks at 4-8 years and 11-15 years. There was an increased incidence of girls in the under-eight age group, who had mild trauma, and in the group of over-eights there were more boys, who had moderate and severe trauma. Dorsal dislocation occurred in 89.9% of cases. Mono-injuries dominated across all age groups. Concomitant injuries rarely occurred before the age of eight; however, they increased with increasing ossification of the acetabulum and appeared as avulsion injuries in 32% of 11-15-year-olds. Of the 76 patients, 4 underwent a spontaneous, 67 a closed and 5 a primary open reduction. A reduction was performed within 6 h on 84% of the children; however, in around 10% of cases a reduction was not performed until after 24 h. Concomitant injuries needing intervention were identified in 34 children following reduction. Complications included nerve irritation in the form of sensitivity disorders (n = 6) as well as avascular necrosis (AVN) of the femoral head in 15.8% of the patients (n = 12). CONCLUSIONS: Traumatic hip dislocations are rare in childhood and adolescence and have high complication rates. The most severe complication, femoral head necrosis, occurred in 16% of cases. Minor injuries, especially in younger children, are enough to cause a dislocation. Posterior dislocation was more frequent and primarily occurred as a mono-injury; however, concomitant injuries must be considered with increasing age. Children continue to experience delayed reductions. The length of time until reduction, age and the severity of the concomitant injury play a role in the development of femoral head necrosis; however, this topic requires additional investigation.

Therapy of a Chronically Infected Total Femur Prothesis in a 40-year-old Patient. / Therapie einer chronischen Infektion einer totalen Femurendoprothese bei einem 40-jährigen Patienten.

We report a case of a patient who was treated in 1999 at the age of 19 years with a proximal femur replacement due to Ewing sarcoma. After several infection-associated exchange procedures, the patient presented with a fistula and chronic infection of a total femur prosthesis in August 2019 at the age of 40 years. Interdisciplinary treatment with a 3-stage exchange procedure and implantation of a silver-coated total femur prosthesis was successfully performed and hip disarticulation could be avoided. After a follow-up of 2 years, the patient showed uneventful wound healing and full weight bearing without crutches.

Imaging, post-processing and navigation: Surgical applications in pelvic fracture treatment.

Technical advancements of the past decade have led to massive improvements regarding imaging and visualization in trauma care. Digital imaging technology has fundamentally changed most processes in fracture management. However, the digital revolution in trauma surgery has just begun. Optical tracking navigation is currently the gold standard for positioning of implants for advanced applications in trauma surgery. Digital technology may enable the surgeon to achieve the same level of safety even in non-navigated placement of screws: We developed a new planning tool to transcript a preoperative into a semi-transparent "fluoroscopic like" image that can be identified intraoperatively and used as a map for the safe placement of sacro-iliac screws based on the "vestibule concept". In the future, development of artificial intelligence algorithms may provide features like automated segmentation of bone-fragments and other applications for a systematic fracture analysis to improve the standard of care in trauma surgery. Digital transformation has massive impact on diagnostics and surgical management of pelvic fractures. Improved visualization technology provides a better understanding of the surgical anatomy of the pelvis and may enable the surgeon to achieve greatest safety in percutaneous placement of screws even without using optical tracking navigation tools. The "para-axial fusion technique" is a useful tool to plan fluoroscopic views based on a 3D dataset prior to the surgery.

Management and Mid-Term Outcome After "Real SCIWORA" in Children and Adolescents.

STUDY DESIGN: Retrospective analysis. OBJECTIVE: The SCIWORA Syndrome (Spinal Cord Injury Without Radiographic Abnormalities) is a rare but potentially severe injury with a peak in childhood and adolescence. With a better understanding of injury patterns and advances in MRI, there is ongoing discussion regarding the "Real SCIWORA" syndrome, a clinical picture of neurologic deficits on clinical examination but absence of radiographic pathologies even on MRI. The purpose of this study was to evaluate mid-term clinical outcome and the psychological impact of the "Real SCIWORA." METHODS: In this retrospective analysis, we evaluated 32 patients treated for "Real SCIWORA" between 2007-2019. Inclusion criteria were: neurologic deficit after trauma, no other cerebral or skeletal injury and a lack of pathological findings in spinal MRI. All patients were followed until complete recovery from initial symptoms. 25/32 patients were re-evaluated after 6.9 years (1-14 years) using the Oswestry Disability Index, the Frankel Score, the EQ-5D score, and the Breslau Short Screening Scale for PTSD. RESULTS: Initial neurologic presentation ranged from Frankel Grade A-D. All patients recovered neurologically during 1-13 days to a Frankel Grade E. The analysis of HR-QoL revealed no difference between the cohort of SCIWORA patients and the German population norm, Oswestry Disability Index showed only minimal disabilities. 4/25 patients showed signs of PTSD. CONCLUSIONS: The "Real SCIWORA" syndrome is a diagnosis per exclusionem requiring a full spinal MRI to ensure exclusion of structural and potentially serious reasons of the neurologic impairment. Further clinical re-evaluation, psychological support seems to be essential. LEVEL OF EVIDENCE: IV-retrospective study.

Metabolic regulation by PD-1 signaling promotes long-lived quiescent CD8 T cell memory in mice.

Inhibitory signaling in dysfunctional CD8 T cells through the programmed cell death 1 (PD-1) axis is well established in chronic viral infections and cancers. PD-1 is also transiently induced to high concentrations during priming of acute infections and immunizations, yet its impact on the development of long-lived antigen-independent T cell memory remains unclear. In addition to its expected role in restraining clonal effector expansion, here, we show that PD-1 expression on antigen-specific CD8 T cells is required for the development of a durable CD8 T cell memory pool after antigen clearance. Loss of T cell­specific PD-1 signaling led to increased contraction and a defect in antigen-independent renewal of memory CD8 T cells in response to homeostatic cytokine signals, thus resulting in attrition of the memory pool over time. Whereas exhausted CD8 T cells regain function after PD-1 checkpoint blockade during chronic viral infection, the preexisting pool of resting functional bystander memory CD8 T cells established in response to a previously administered immunogen decreased. Metabolically, PD-1 signals were necessary for regulating the critical balance of mTOR-dependent anabolic glycolysis and fatty acid oxidation programs to meet the bioenergetic needs of quiescent CD8 T cell memory. These results define PD-1 as a key metabolic regulator of protective T cell immunity. Furthermore, these results have potential clinical implications for preexisting CD8 T cell memory during PD-1 checkpoint blockade therapy.

Surgical Drill Guide for Insertion of an Infra-Acetabular Screw Based on an Anatomically Precontoured Plate System: A Cadaveric Study.

PURPOSE: Due to the anatomic structure of the pelvis, free-hand placement of screws in the acetabular fracture management can be difficult. Infra-acetabular screw fixation increases acetabular stability by distal fixation of the cup. Aim of this cadaveric study is to investigate if a plate-referenced drill guide can provide save placement of an infra-acetabular screw over a precontoured suprapectineal quadrilateral buttress plate (SQBP). METHODS: We constructed a drill guide for an infra-acetabular screw based on the surface of an anatomically precontoured SQBP. A total of 12 adult cadaveric acetabular specimens were used for drill guide-assisted placement of the infra-acetabular screw. The drill guide contains a radiopaque spiral to allow longitudinal fine adjustment of the SQBP along the pelvic brim to assure correct position of the plate-drill-guide construct in relation to the Koehler's teardrop. After screw placement, we conducted a computed tomography (CT) scan of all specimens to assess the actual position of the screw in relation of the infra-acetabular corridor and the acetabular joint surface. RESULTS: The position of the screw was within the infra-acetabular corridor in all cases. We did not see any intra-articular or intrapelvic screw penetration. The mean distance of the centerline of the screw to the medial border of the infra-acetabular corridor was 3.35 mm. The secure distance to the virtual surface of the femoral head to was 7.3 mm. CONCLUSIONS: A plate-referenced drill guide can provide safe placement of an infra-acetabular screw for treatment of acetabular fractures. Radiographic fine adjustment is necessary to access the optimal entry point.

Bilateral septic arthritis with rapid progressive destruction of the femoral head after joint injection in rheumatoid arthritis.

This report is on a 61-year-old patient with steroid therapy for rheumatoid arthritis and pain in the groin on both sides who got injections with hyaluronic acid in both hip joints. After 12 weeks the X-ray of the pelvis showed rapid progressive destruction of both hip joints.

The Incidence of Fractures Among the Adult Population of Germany­an Analysis From 2009 through 2019

BACKGROUND: Detailed analyses of epidemiological data on fractures are an impor - tant resource for persons and institutions providing health care services, as they yield information on the effects of current treatment strategies and on the need for preventive measures. The epidemiology of fractures in Germany, however, is unknown. The goal of this study is to determine the nationwide fracture burden from 2009 through 2019, as a function of anatomical site, age, and sex. METHODS: Annual compilations of ICD-10 diagnosis codes for the years 2009-2019 were made available to us by the German Federal Statistical Office. The prevalence and incidence of fractures at 30 different sites were quantified, and standardized sex and age distributions were calculated. RESULTS: A total of 688 403 fractures was registered in 2019. From 2009 to 2019, the incidence of fractures rose by 14%, to 1014 fractures per 100 000 persons per year. The most common fracture types were femoral neck fractures (120 per 100 000 persons per year), pertrochanteric femoral fractures (109 per 100 000 persons per year), and distal radius fractures (106 per 100 000 persons per year). All types were more common in women, with incidences that rose with age. The highest incidence was of pertrochanteric femoral fractures in women over age 90, with an incidence of 2550 per 100 000 persons per year. The largest rises in incidence were seen with regard to acetabular fractures (+ 58%) and clavicular fractures (+ 44%). CONCLUSION: The increasing frequency of fractures, particularly among the elderly, presents a challenge to the health care system. Given the high frequency of geriatric fractures, prophylactic measures against fractures ought to be intensified.

[Comparison of DRG revenues between fast and slow-track procedures for a two-stage replacement of prostheses for periprosthetic hip infections in the aG-DRG system 2020]. / Vergleich der DRG-Erlöse zwischen Fast- und Slow-Track-Verfahren beim zweizeitigen Prothesenwechsel bei periprothetischen Hüftinfektionen im aG-DRG-System 2020.

BACKGROUND: The treatment of periprosthetic hip infections is usually cost intensive, so it is generally not cost effective for hospitals. In chronic infections, a two-stage procedure is often indicated, which can be done as a fast-track procedure with a short prosthetic-free interim interval (2-4 weeks) or as a slow-track procedure with a long prosthetic-free interim interval (over 4 weeks). AIM: The aim of this study was to elucidate the revenue situation of both forms of treatment in the aG-DRG-System 2020, taking into account revenue-relevant influencing factors. METHODS: For fast-track and slow-track procedures with two-stage revision and detection of a staphylococcus aureus (MSSA), treatment cases were simulated using a grouper software (3M KODIP Suite) based on the diagnoses (ICD-10-GM) and procedures (OPS) and then grouped into DRGs. Revenue-relevant parameters, such as length of stay and secondary diagnoses (SD), were taken into account. In addition, two real treatment cases with fast-track and slow-track procedures were compared to each other. RESULTS: The total revenues for the slow-track procedure with a length of stay of 25 days (without SD) were 27,551 € and for a length of stay of 42 days (with SD) even 40,699 €, compared to 23,965 € with the fast-track procedure with a length of stay of 25 days (without SD) and 27,283 € for a length of stay of 42 days (with SD). The real treatment cases also showed a big difference in the total revenues of 12,244 € in favor of the slow-track procedure. DISCUSSION: Even in the aG-DRG-System 2020, the two-stage revision procedure with a long interim interval seems to be more interesting from a financial point of view and the hospital perspective compared to the fast-track procedure, especially with multimorbid patients. This creates a financial barrier to the treatment of such patients with a short interim interval.

Evaluation of joint awareness after acetabular fracture: Validation of the Forgotten Joint Score according to the COSMIN checklist protocol.

BACKGROUND: A fracture of the acetabulum is an uncommon, but serious injury. Established outcome tools do not reflect the patient's perspective after fracture of the hip joint. Originally designed for post-arthroplasty patients, the Forgotten Joint Score (FJS) is a patient-reported outcome measurement (PROM) tool evaluating the disease-specific health-related quality of life (HR-QoL). AIM: To validate the FJS in patients after acetabular fracture. METHODS: In a prospective mono-centric cohort study, we evaluated 100 patients at mean 5.2 ± 3.6 years after a fracture of the acetabulum. The validation study followed the complete COSMIN checklist protocol. For calculation of convergent validity, we used the Tegner-Activity Scale, the Western Ontario and McMaster Universities Osteoarthritis Index, the EuroQol-5D, and a subjective rating of change as an anchor variable. RESULTS: We confirmed good internal consistency with a Cronbach's alpha of 0.95. With an intraclass correlation coefficient of 0.99 (95%CI: 0.97, 0.99), test-retest reliability of the FJS was excellent. Correlation coefficients between the questionnaires were moderate to high ranging from |0.56| to |0.83| (absolute value). No relevant floor or ceiling effects occurred. Standard error of measurement was 3.2 and smallest detectable change (SDC) was 8.8. Thus, changes greater than 8.8 points between two assessments denote a real change in FJS. CONCLUSION: The FJS is a valid and reliable tool for evaluation of patient-reported outcome in posttraumatic condition after acetabular fracture. The SDC indicating a real clinical improvement was 8.8 points in the FJS. We could confirm responsiveness of the FJS and found no relevant floor- or ceiling effects.

Two-Dimensional Visualization of the Three-Dimensional Planned Sacroiliac Screw Corridor with the Slice Fusion Method.

Insertion of sacro-iliac (SI) screws for stabilization of the posterior pelvic ring without intraoperative navigation or three-dimensional imaging can be challenging. The aim of this study was to develop a simple method to visualize the ideal SI screw corridor, on lateral two-dimensional images, corresponding to the lateral fluoroscopic view, used intraoperatively while screw insertion, to prevent neurovascular injury. We used multiplanar reconstructions of pre- and postoperative computed tomography scans (CT) to determine the position of the SI corridor. Then, we processed the dataset into a lateral two-dimensional slice fusion image (SFI) matching head and tip of the screw. Comparison of the preoperative SFI planning and the screw position in the postoperative SFI showed reproducible results. In conclusion, the slice fusion method is a simple technique for translation of three-dimensional planned SI screw positioning into a two-dimensional strict lateral fluoroscopic-like view.

Comprehensive treatment algorithm for atlanto-axial rotatory fixation (AARF) in children.

BACKGROUND: Atlanto-axial rotatory fixation (AARF) is an uncommon condition in children presenting with torticollis. Many studies have elaborated on the diagnostic sequence of AARF. However, there is no consensus for the algorithm of management of AARF. METHODS: This study proposes to provide a comprehensive step-by-step guideline which aims to achieve and retain anatomic reduction of the atlanto-axial joint (AAJ). We recommend a 'therapeutic crescendo': closed reduction and immobilization in a rigid cervical collar (step I). In cases of re-dislocation, a second attempt of closed reduction and immobilization in a Halo-jacket (step II). Cases of recurrent dislocations due to persistent instability require open reduction and internal fixation. We present a new surgical technique of transverse suture transfixation (TSF) of C1/C2 (step III). Alternatively, a dorsal stabilization of C1/C2 is indicated after open reduction (step IV). 13 patients with radiologically confirmed AARF were included in this study. These patients were treated as per the above mentioned algorithm. All these patients were serially evaluated with a minimum follow-up of 1 year. RESULTS: Clinical data of 10/13 patients were available for follow-up evaluation at mean 4.6 years after the onset of symptoms. Two patients were managed surgically. We recorded good clinical results in all patients treated according to the algorithm. CONCLUSIONS: AARF is a subacute pediatric emergency. Reduction and maintenance of joint congruency of the AAJ are the treatment goals. The comprehensive therapeutic algorithm presented in this study is applicable in patients with AARF to achieve excellent long-term results. LEVEL OF EVIDENCE: IV, Retrospective cohort study. TRIAL REGISTRATION NUMBER: Clinical Trial Registry University of RegensburgZ-2014-0453-4. Registered 01 December 2014.

[PJI-TNM as new classification system for periprosthetic joint infections : An evaluation of 20 cases]. / PJI-TNM als neues Klassifikationssystem für Endoprotheseninfektionen : Eine Evaluation von 20 Fällen.

BACKGROUND: Current classifications for periprosthetic joint infections (PJIs) often lack a detailed description of the overall underlying situation of a patient. The PJI-TNM classification uses the principles of the TNM classification from oncology for the description of critical parameters in PJIs: affected joint, type of implant and implant stability, soft tissue conditions, maturity of biofilm formation, causative microorganism, comorbidities of the patient and recurrence of infection. The aim of the current work is to evaluate the feasibility of this new PJI-TNM classification in clinical practice. METHODS: The PJI-TNM classification was used in 20 patients with hip, knee and shoulder PJIs. Based on a retrospective chart review, the respective parameters T (tissue and implants), N (non-eukaryotic cells and fungi), M (morbidity) and r (reinfection) were classified for each case. RESULTS: All 20 cases (12 male, 8 female, average age 72.2 (40-88 years)) with 13 hip, 6 knee and 1 shoulder PJIs were to be classified with the new TNM-PJI classification system. There was a considerable heterogeneity among the cases: 12 protheses were fixed (T0), 6 were loosened (T1) and 2 were associated with a soft tissue defect (T2). Biofilm formation was considered immature in 7 cases (N0). Out of the PJIs, 13 were considered to be associated with mature biofilm formation. Out of the patients, 9 were systemically not or only mildly compromised (M0), 7 patients moderately (M1) and 3 patients (M2) severely compromised. One patient refused surgical treatment (M3a). Recurrent infections (r) were diagnosed in three cases. CONCLUSIONS: The principles of the TNM classification from oncology can also be used for the classification of PJIs. Despite the limited number of cases in this study, a considerable heterogeneity of the evaluated PJIs is shown, which is a phenomenon that is also known from clinical practice. This heterogeneity can be adequately addressed by this new classification, which might be beneficial in decision-making in the future.

Early functional treatment or trivialization? - current treatment strategies in lateral ligament injuries of the ankle.

Introduction: Ankle injuries are common in daily orthopaedic trauma practice, with a high incidence of lateral ligament complex (lat-lig-com) injuries of the ankle joint (AJ). Primarily, these lat-lig-com injuries heal sufficiently, although there is a risk of developing chronic ankle instability. However, there is a lack of knowledge about the clinical application and routine for rehabilitation strategies so as to prevent chronic instability. This study investigates the current rehabilitation concepts in clinical routine after ligament injuries of the AJ. Methods: Rehabilitation protocols, provided by orthopaedic and trauma surgery institutions in German speaking countries, were analysed in terms of weight-bearing, range of motion (ROM), physiotherapy and choice of orthosis. All protocols for operatively and non-operatively (nop) treated ligament ruptures of the AJ were included. Results: 120 of 213 institutions provided protocols of lat-lig-com injuries of the AJ. Regarding the orthosis, the nop-treatment group mainly used ankle braces; in contrast, the operative group preferred the use of an ankle boot. The operative group recommends 6-12 weeks for duration of orthosis in contrast to only 6 weeks in the nop group. Significant differences prevail in ROM, with free ROM in non-operative treatment from the first day after trauma (p<0.001) in contrast to a careful increase in ROM in the first 6 weeks post-operatively. Conclusion: Early functional treatment is clinical standard in rehabilitation after lat-lig-com injuries of the ankle. Regarding current literature the differences of restrictions in ROM and orthosis treatment after lat-lig-com injuries suggest a trivialization of conservative treatment in the first period after trauma compared to post-operative aftercare.

Patient-reported outcome after patient-specific unicondylar knee arthroplasty for unicompartmental knee osteoarthritis.

BACKGROUND: Unicondylar knee arthroplasty was introduced in the late 1960s and remains a topic of controversial discussion. Patient-specific instruments and patient-specific implants are not yet the standard of care. The question remains whether this time-consuming and costly technique can be beneficial for the patient. The aim of this study was to evaluate whether a custom-made unicondylar knee arthroplasty leads to improved patient-reported outcome. METHODS: This retrospective study evaluates the patient-reported outcome after custom-made unicondylar knee arthroplasty (CM-UKA, ConforMIS™ iUni® G2, ConforMIS Inc., Billerica, MA, USA). We evaluated 29 patients (31 knees) at an average of 2.4 years (range 1.2-3.6 years) after operation for unicondylar osteoarthritis of the knee. The target zone for the postoperative leg axis was a slight under-correction of 0-2° varus. Follow-up evaluation included the Forgotten Joint Score (FJS), the Knee Society Score (KSS), a Visual Analogue Scale (VAS) and a radiographic evaluation including a long-leg radiograph. Primary outcome measure was patient satisfaction based on the Forgotten Joint Score. RESULTS: We found an excellent postoperative health-related quality of life with a mean FJS of 76.8 (SD 17.9) indicating a low level of joint awareness after CM-UKA. The mean preoperative KSS was 66.0 (SD 13.71) and 59.4 (17.9) for the KSS function score. The increase was 22.8 points for the KSS knee score (p < 0.0001) and 34.8 points for the KSS function score (p < 0.0001). The VAS for pain decreased from a mean of 5.4 (SD 1.8) to 1.1 (SD 1.2) (p < 0.0001). The malalignment rate with a postoperative deviation of more than 2° in the leg axis was 29%. There was no evidence of component loosening after a mean follow-up of 2.4 years. CONCLUSIONS: Custom-made unicondylar knee arthroplasty (CM-UKA) can provide improved clinical and functional outcomes for patients with isolated knee osteoarthritis of the medial compartment. We found excellent results regarding patient satisfaction and a low malalignment rate for CM-UKA. Further studies are needed to investigate long-term survivorship of the implant. LEVEL OF EVIDENCE: Level IV. TRIAL REGISTRATION: Trial Registration number: Z-2014-0389-10 Regensburg Clinical Studies Center (REGCSC) 09/07/2014.