How Useful Is Preoperative Aspiration before Revision of Unicompartmental Knee Prostheses Because of Osteoarthritis in the Other Compartments?

AIM

Periprosthetic joint infections (PJIs) of unicompartmental knee arthroplasties (UKAs) can lead to secondary osteoarthritis of the other compartments. The objective of this study was to identify the frequency of PJIs in cases of UKA with progressed secondary osteoarthritis and the result of septic one-stage revision in these cases to verify the value of preoperative aspiration in cases of secondary osteoarthritis of UKA.

METHODS

We retrospectively reviewed 97 patients with a unicompartmental arthroplasty who underwent revision surgery to a total knee arthroplasty (TKA) between January 2013 and March 2021 because of subsequent osteoarthritis. Preoperative aspiration and sample collection during the revision surgery were employed to identify potential periprosthetic joint infections (PJIs). The post-revision period was monitored for septic complications over an average duration of 55.7 ± 25.2 months (24-113).

RESULTS

PJIs were identified in 5.2% of cases through preoperative aspiration. In all instances of PJIs, a one-stage septic revision was performed, and notably, none of these cases experienced septic complications during the follow-up period.

CONCLUSIONS

Preoperative aspiration is essential in order to exclude the presence of a PJI before performing revision surgery of UKA due to secondary osteoarthritis.

Diagnostics in Late Periprosthetic Infections-Challenges and Solutions

The rising number of arthroplasties is combined with a rising number of periprosthetic joint infections, which leads to life-concerning consequences for the patients, including extended antibiotic treatment, further surgery and increased mortality. The heterogeneity of the symptoms and inflammatory response of the patients due to, e.g., age and comorbidities and the absence of a single diagnostic test with 100% accuracy make it very challenging to choose the right parameters to confirm or deny a periprosthetic joint infection and to establish a standardized definition. In recent years, additional diagnostic possibilities have emerged primarily through the increasing availability of new diagnostic methods, such as genetic techniques. The aim of the review is to provide an overview of the current state of knowledge about the various tests, including the latest developments. The combination of different tests increases the accuracy of the diagnosis. Each physician or clinical department must select the tests from the available methods that can be best implemented for them in organizational and technical terms. Serological parameters and the cultivation of the samples from aspiration or biopsy should be combined with additional synovial tests to create an accurate figure for the failure of the prosthesis, while imaging procedures are used to obtain additional information for the planned therapeutic procedure.

Revision total hip arthroplasty using a modular fluted, tapered revision femoral component and interlocking screws in Vancouver B3 periprosthetic fractures with insufficient bone at the isthmus

Aims

Revision total hip arthroplasty in patients with Vancouver type B3 fractures with Paprosky type IIIA, IIIB, and IV femoral defects are difficult to treat. One option for Paprovsky type IIIB and IV defects involves modular cementless, tapered, revision femoral components in conjunction with distal interlocking screws. The aim of this study was to analyze the rate of reoperations and complications and union of the fracture, subsidence of the stem, mortality, and the clinical outcomes in these patients.

Methods

A total of 46 femoral components in patients with Vancouver B3 fractures (23 with Paprosky type IIIA, 19 with type IIIB, and four with type IV defects) in 46 patients were revised with a transfemoral approach using a modular, tapered, cementless revision Revitan curved femoral component with distal cone-in-cone fixation and prospectively followed for a mean of 48.8 months (SD 23.9; 24 to 112). The mean age of the patients was 80.4 years (66 to 100). Additional distal interlocking was also used in 23 fractures in which distal cone-in-cone fixation in the isthmus was < 3 cm.

Results

One patient (2.2%) died during the first postoperative year. After six months, 43 patients (93.5%) had osseous, and three had fibrous consolidation of the fracture and the bony flap, 42 (91.3%) had bony ingrowth and four had stable fibrous fixation of the stem. No patient had radiolucency around the interlocking screws and no screw broke. One patient had non-progressive subsidence and two had a dislocation. The mean Harris Hip Score increased from of 57.8 points (SD 7.9) three months postoperatively to 76.1 points (SD 10.7) 24 months postoperatively.

Conclusion

The 2° tapered, fluted revision femoral component with distal cone-in-cone-fixation, combined with additional distal interlocking in patients with bony deficiency at the isthmus, led to reproducibly good results in patients with a Vancouver B3 fracture and Paprosky type IIIA, IIIB, and IV defects with regard to union of the fracture, subsidence or loosening of the stem, and clinical outcomes.

Graphic type differentiation of cell count data for diagnosis of early and late periprosthetic joint infection: A new method

BACKGROUND

Graphic type differentiation of cell count data of synovial aspirates is a new method for the diagnosis of early and late periprosthetic joint infection.

OBJECTIVE

The aim of the study was to analyse if the same 6 LMNE-types can be differentiated in the new Yumizen H500 cell counter as it was the case for the old cell counter ABX Pentra XL 80 of previous publications, to verify if the erythrocyte and thrombocyte curves of the new device give additional information and to calculate the difference of cell count in LMNE-type I and III (with abrasion) in the cell counter and in the manual counting chamber (Neubauer improved).

METHODS

450 aspirates of 152 total hip arthroplasties and 298 knee arthroplasties obtained for the diagnosis of periprosthetic joint infection were analysed with the Yumizen H500.

RESULTS

All LMNE-matrices of the 450 aspirates could assigned to one of the six LMNE-types. There were 76 LMNE-type I, 72 LMNE-type II, 14 LMNE-type III, 241 LMNE-type IV, 36 LMNE-type V and 12 LMNE-type VI. The erythrocyte and thrombocyte distribution curves were very helpful for differentiation of hematoma and infection. The cell count in the manual counting procedure was lower than in the cell counter: for the LMNE-type I (abrasion type) the median of the difference was 925/μL (median) and for the LMNE-type III (combined type of infection and abrasion) 3570/μL (median).

CONCLUSION

The described graphic type differentiation is a new and helpful method for differentiation of hematoma and early PJI as well as abrasion and late PJI.

A Low Rate of Periprosthetic Infections after Aseptic Knee Prosthesis Revision Using Dual-Antibiotic-Impregnated Bone Cement

AIM

The incidence of periprosthetic joint infections (PJI) following aseptic knee revision arthroplasty lies between 3% and 7.5%. The aim of this study was to verify the hypothesis that the use of dual-antibiotic-impregnated cement in knee revision arthroplasty leads to a lower rate of periprosthetic joint infections.

METHODS

We retrospectively reviewed 403 aseptic revision knee arthroplasties performed between January 2013 and March 2021 (148 revisions of a unicompartmental prosthesis, 188 revisions of a bicondylar total knee arthroplasty (TKA), 41 revisions of an axis-guided prosthesis, and 26 revisions of only one component of a surface replacement prosthesis). The bone cement Copal G+C (Heraeus Medical, Wertheim, Germany) with two antibiotics-gentamycin and clindamycin-was used for the fixation of the new implant. The follow-up period was 53.4 ± 27.9 (4.0-115.0) months.

RESULTS

Five patients suffered from PJI within follow-up (1.2%). The revision rate for any reason was 8.7%. Survival for any reason was significantly different between the types of revision (p = 0.026, Log-Rank-test), with lower survival rates after more complex surgical procedures. The 5-year survival rate with regard to revision for any reason was 91.3% [88.2-94.4%] and with regard to revision for PJI 98.2% [98.7-99.9%], respectively.

CONCLUSION

The use of the dual-antibiotic-impregnated bone cement Copal G+C results in a lower rate of periprosthetic infections after aseptic knee prosthesis replacement than that reported in published prosthesis revisions using only one antibiotic in the bone cement.

Total Knee Arthroplasty in Unrecognized Septic Arthritis-A Descriptive Case Series Study

BACKGROUND

Synovitis, like that associated with chronic bacterial arthritis, is a very rare finding during the implantation of knee endoprostheses. In such cases, we fix the knee prostheses with cement containing two antibiotics and carry out a course of systemic antibiotic administration. The aim was to analyze these cases for incidence, detection of bacteria, risk factors, and outcome.

METHODS

Out of 7534 knee replacements between January 2013 and December 2020, 25 cases were suspected during the surgical procedure to have suffered from bacterial arthritis and were treated accordingly. Total synovectomy was carried out, whereby five intraoperative synovial samples were examined bacteriologically, and the complete synovitis was analyzed histologically. The mean follow-up was 65.3 ± 27.1 (24-85) months.

RESULTS

In nine cases (0.12%), the diagnosis of bacterial arthritis was made histologically and by clinical chemistry (elevated CRP), and in two of these cases, pathogen verification was performed. Eight of these nine patients had previously had injections or surgery associated with the corresponding knee joint or had an underlying immunomodulatory disease. None of the patients developed a periprosthetic infection at a later stage.

CONCLUSION

With an incidence of 0.12%, it is rare to unexpectedly detect bacterial synovitis during surgery. Total synovectomy, use of bone cement with two antibiotics, and immediate systemic antibiotic therapy seem to keep the risk of periprosthetic infection low.

Digit ratio (2D:4D) and its relationship to foetal and maternal sex steroids: A mini-review

The challenges of terrestrial existence may mean that the early development of tetrapod limb traits is linked to the development of the urogenital system and sex steroids. One such limb trait is the sex-dependent ratio of the lengths of the 2nd and 4th digits (2D:4D). Direct evidence for the association between early sex steroids and offspring 2D:4D can be obtained by manipulating foetal sex hormones. However, this is not ethically permissible in humans. It is widely accepted that 2D:4D is a biomarker for early foetal sex hormones in tetrapods but the link in humans remains controversial. Here we review the evidence that (i) manipulation of sex steroids in early development leads to sex-dependent changes in 2D:4D throughout the tetrapods, and (ii) maternal sex steroids cross the placenta and thus are associated with offspring 2D:4D in both non-human and human animals. We suggest a research focus on associations between human maternal sex steroids and offspring 2D:4D to clarify the link between 2D:4D and early sex steroids. A protocol is proposed to examine the correlation between 1st-trimester maternal sex steroids and offspring 2D:4D. Such an association may explain the existence and medium effect size of the human sex difference in 2D:4D.

The Use of Intraoperative Cell Salvage in Two-Stage Revision of Septic Hip Arthroplasties: A Double-Center Retrospective Study

(1) Background: intraoperative cell salvage (ICS) devices can provide a valuable contribution to patient blood management. An infection of the surgical site presents a formal contraindication to the use of ICS. To date, there is no recommendation for the use of ICS in the context of reimplantation in two-stage septic exchange arthroplasty. (2) Methods: at two hospitals of maximum endoprosthetic care, a retrospective evaluation of patients who had received ICS blood during reimplantation of hip arthroplasties was performed. Patients' and surgical characteristics, intraoperative cultures, and the occurrence of septic complications in the short- and long-term follow-up were recorded. (3) Results: 144 patients were included. Detection of positive cultures during reimplantation occurred in 13 cases. A total of 127 patients showed no complication, 8 patients showed a non-specific septic complication, 6 patients a local persistence of infection, and 3 patients a possible bloodstream-associated infection. No significant correlation was found between the occurrence of complications and the detection of positive intraoperative cultures. (4) Conclusions: no clustering of septic complications due to the use of ICS during reimplantation was found. In the risk-benefit analysis, we considered the use of ICS during reimplantation to be indicated in terms of patient blood management, while the safety of the procedure during septic first-stage resection arthroplasty or septic one-stage exchange arthroplasty was not investigated. Given the paucity of comparative literature, further studies are needed on ideal patient blood management in the setting of septic revision arthroplasty.

Outcomes of osteosynthesis of periprosthetic fractures of the greater trochanter with an anatomic claw plate

Background

The treatment of periprosthetic trochanteric fractures, especially older fractures, is often a challenge. The aim of this study was to investigate the clinical and radiological outcomes of periprosthetic fracture treatment with the anatomic Peri-Plate claw plate.

Material and methods

Thirteen new fractures (≤6 weeks after occurrence) and 8 older Vancouver AG fractures (35.4 ± 26.1 weeks after occurrence) were followed radiologically and clinically with a follow-up of 44.6 ± 18.8 (24-81) months.

Results

At 6 months, osseous consolidation had occurred in 12 cases and fibrous union in 9 cases. At 12 months one additional osseous consolidation was shown. The Harris hip score (HHS) increased from 37.2 ± 10.3 preoperatively to 87.6 ± 10.3 12 months after surgery. Thirteen patients reported no, 7 mild and one patient significant local trochanteric pain.

Conclusions

The Peri-Plate claw plate can achieve reproducibly good outcomes in terms of fracture stabilization and bony consolidation, as well as with regard to clinical outcomes in the treatment of new and older periprosthetic trochanteric fractures.

Clinical evaluation of a new technique for custom-made spacers in septic two-stage revision of total hip arthroplasties

INTRODUCTION

In septic two-stage revision surgery, success depends on numerous factors. Key steps are the procedure of ex- and reimplantation and the choice of spacer in the interim phase. The latter is still a matter of debate. Recently, we showed the microbial non-inferiority of a spacer technique using prosthetic cemented implants with an individualized antibiotic mixture in the cement applying a mechanically inferior cementation method. The aim of the present study was to evaluate the clinical results of these spacers in view of either an endofemoral or a transfemoral procedure.

MATERIALS AND METHODS

Our collective consisted of 86 patients (45 endofemoral and 41 transfemoral procedures). The collective was analyzed with respect to complications, reinfection rate and clinical status at the end of the interim phase. Results of an endofemoral and transfemoral approach were compared.

RESULTS

With a median Staffelstein-Score of 60 (range 31-81) at the end of the interim phase, the first clinical results are promising. The reinfection-free rate after a median follow-up of 50 months was 90%. Spacer-related complications occurred in 8% of the total collective. Comparing the endo- and transfemoral procedure, there were no statistical differences in complications or regarding the clinical and infectiological outcome.

CONCLUSIONS

In this study, we were able to show good clinical results for the presented spacer technique. With no relevant difference in outcome, the decision for an endofemoral or transfemoral technique can be based on technical deliberations. Further prospective comparative studies are necessary to show the clinical benefit of this procedure.

Diagnostic Value of C-Reactive Protein and Serum White Blood Cell Count during Septic Two-Stage Revision of Total Knee Arthroplasties

AIMS AND METHODS

In septic two-stage revision arthroplasty, the timing of reimplantation is crucial for therapeutic success. Recent studies have shown that singular values of C-reactive protein (CRP) and white blood cell count (WBC count) display weak diagnostic value in indicating whether periprosthetic joint infection (PJI) is controlled or not during two-stage revision surgery of knee arthroplasty. Therefore, in addition to the values of CRP and WBC, the course of CRP and WBC counts were compared between groups with and without later reinfection in 95 patients with two-stage revision (TSR) of infected total knee arthroplasties (TKA). Of these patients, 16 had a reinfection (16.84%).

RESULTS

CRP values decreased significantly after the first stage of TSR in both the reinfection and no-reinfection groups. WBC count values decreased significantly in the no-reinfection group. Decrease in WBC count was not significant in the reinfection group. No significant difference could be found in either the CRP values or the WBC counts at the first stage of TSR, the second stage of TSR, or their difference between stages when comparing groups with and without reinfection. Area under the curve (AUC) values ranging between 0.631 and 0.435 showed poor diagnostic value for the calculated parameters. The courses of CRP over 14 days after the first stage of both groups were similar with near identical AUC.

CONCLUSIONS

CRP and WBC count as well as their course over 14 days postoperatively are not suitable for defining whether a PJI of the knee is under control or not.

Antibiotics in Orthopedic Infections

The management of orthopedic infections has continuously been gaining increasing interest in the past few years [...].

New Technique for Custom-Made Spacers in Septic Two-Stage Revision of Total Hip Arthroplasties

The choice of spacer in the interim phase of two-stage revision hip arthroplasty is crucial. Conventional concepts like a Girdlestone situation, handformed or preformed bone cement spacers show complications like soft-tissue contractions, abrasion of bone cement particles, dislocation, breakage and a low level of mobility in the interim phase. To address these disadvantages, the senior author developed a new technique for custom-made spacers in septic two-stage revision of total hip arthroplasties using prosthetic implants with individualized antibiotic mixture in the cement applying a mechanical inferior cementation method. The aim of this study was to evaluate the results of these spacers with respect to their non-inferiority in terms of reinfection and survival-rate of the new implant and to describe the complications associated with this procedure. Our collective consisted of 130 patients with a median follow-up of nearly five years. With a reinfect-free rate of 92% and a spacer-related complication rate of 10% (8% articular dislocation, 1% periprosthetic joint fracture, 1% breakage), this procedure seems to be safe and superior regarding complications compared to conventional concepts. Further studies are necessary to show the clinical benefit of this procedure.

Mentalisierungsfähigkeit und Empathie in der Psychiatrie – eine Sozialisationsfrage?

Berufliche Sozialisation entwickelt sich im Kontext der Persönlichkeitsentwicklung und vorhandener Bedingungen unterschiedlich. Das Aufrechterhalten der Mentalisierungsfähigkeit im beruflichen Alltag und vor allem in herausfordernden Situationen ist keine Selbstverständlichkeit, sondern abhängig von Umgebungsbedingungen. Die Übernahme von Verantwortung für die gewählte berufliche Tätigkeit erfordert eine Auseinandersetzung mit dem jeweils spezifischen Anforderungsprofil; es stellen sich Lern- und Entwicklungsaufgaben. Die Integration der beruflichen Identität im Rahmen förderlicher Umgebungsbedingungen bedeutet, sich als Teil dieser Gruppe(n) zu erleben. Aus gruppenpsychoanalytischer Sicht stellt die Identifikation mit einer Gruppe eine Verinnerlichung eines „guten Objekts“ dar, einer Gruppenrepräsentanz, welche in herausfordernden Situationen zugänglich ist. Dies kann die Mentalisierungsfähigkeit verbessern.

Technical Note for Transfemoral Implantation of Tapered Revision Stems. The Advantage to Stay Short

Background

The aim was to test the hypothesis that during transfemoral implantation of a conical revision stem, the fixation of the stem at the distal tip leads to a low rate of periprosthetic fractures.

Material and Methods

Two hundred eighty-two stem revisions by a transfemoral approach in cases of Paprosky Type II and IIIA-defects (with a sufficient isthmus) were carried out and analyzed during and radiographically after the surgery for unintentional periprosthetic fractures below the osteotomy.

Results

In all cases, fixation was always achieved at the tip of the distal component in the isthmus of the femur. No periprosthetic fractures were observed.

Conclusions

When the isthmus of the femur is intact, a transfemoral implantation of a tapered revision stem at the distal end reduces the risk of periprosthetic fractures by preventing bypassing the isthmus with the stem. Knowing the difference between the nominal diameter and the diameter at the distal start of the conical zone can help to create this fixation technique resulting in short revision stems.

Antibiotic therapy alone does not have a high success rate in cases of unexpected positive cultures in intraoperative samples from hip and knee prosthesis revision

BACKGROUND

Unexpectedly positive bacterial cultures during prosthesis revision surgery still occur on occasion despite good preoperative diagnostics. In such cases a six-week antibiotic therapy without further surgical intervention is recommended. The aim of this study was to find out how successful this procedure is.

METHODS

In a study of 508 patients, who required revision surgery of total hip (THA, n = 231) or knee arthroplasties (TKA, n = 277) because of component loosening, biopsy was carried out before their surgery. The collected tissue samples (5) from the biopsy and the revision surgery procedure itself were analyzed according the criteria of the International Consensus Meeting (ICM). Tests revealed 11 patients (7 THA, 4 TKA) with unexpectedly positive bacterial cultures from tissue samples obtained during the revision surgery due to false negative preoperative diagnostic results. These 11 patients were treated with 6 weeks antibiotic therapy and examined with a follow-up of at least 2 years (42.2 ± 16.5 months).

RESULTS

Five patients (2 TKA, 3 THA) became reinfected, resulting in a success rate of 54.5%.

CONCLUSION

Antibiotic therapy alone of an unexpected positive intraoperative bacterial culture in prosthesis revision surgery seems to be less successful than previously assumed.

Three-step technique for implantation of rotating hinge knee prostheses : Demonstration using the Enduro prosthesis

OBJECTIVE

Implantation of an axis-guided knee prosthesis with consideration of the joint line and balanced flexion and extension gap to reduce the mechanical load on the prosthesis axis and to improve the movement of the prosthesis.

INDICATIONS

Distinct unilateral instability due to ligament insufficiency in association with knee prostheses. Primary implantation of axis-guided knee prostheses with pronounced axial malalignment (>20-25° valgus or varus malalignment) or/and severe flexion contracture > 40°. Replacement of prosthesis with nonsignificant imbalance between flexion and extension gap.

CONTRAINDICATIONS

Clearly unstable flexion gap such that the extension gap cannot be adjusted appropriately. Significant femoral bone defects requiring distal femoral replacement prostheses.

SURGICAL TECHNIQUE

Reconstruction of the tibial platform with the trial prosthesis with regard to height in relation to the tip of the fibula. Determination of the femoral prosthesis size. Adjustment of the anteroposterior (AP) cutting block of the selected size, referenced anteriorly and in correct rotation. Determination of the flexion gap with spacers using the stable side of the collateral ligaments. Positioning the distal cutting block and determination of the height of the extension gap. Moving the distal cutting block until the same height of spacer as used in the flexion gap fits into the extension gap, taking into account the stable side of the collateral ligaments. The extent of the displacement D1 is noted. Reverse displacement of the distal cutting block by the distance D2 until a satisfactory bony contact surface for the femoral component in the distal femur can be created. The thickness of the required distal augments on the following chamfer-cutting guide (4-in‑1 cutting block) and thus on the femoral prosthetic component is the sum of D1 + D2. The chamfer-cutting guide (4-in‑1 block) with distal augments of the calculated height (D = D1 + D2) is placed in position. Definition and preparation of the posterior contact surface with positioning of any necessary posterior augments. Completion of the femoral preparation taking into account the distal and posterior augments. Assembly of the trial prostheses with a trial inlay having the height of the spacers used. Implantation of the selected prosthesis components.

POSTOPERATIVE MANAGEMENT

Thrombosis prophylaxis, physiotherapy under full weight-bearing and mobility exercises.

RESULTS

After implantation of 104 axis-guided Enduro™ knee prostheses (Aesculap AG, Tuttlingen, Germany) (73 knee prosthesis revisions and 31 primary implantations), the Knee Society Score increased from 42.8 ± 18.8 preoperatively to 84.8 ± 13.9 after 24 months. Complications comprised one deep vein thrombosis and one periprosthetic infection.

The diagnostic value of routine preliminary biopsy in diagnosing late prosthetic joint infection after hip and knee arthroplasty

AIMS

Biopsy of the periprosthetic tissue is an important diagnostic tool for prosthetic joint infection (PJI) as it enables the detection of the responsible microorganism with its sensitivity to antibiotics. We aimed to investigate how often the bacteria identified in the tissue analysis differed between samples obtained from preoperative biopsy and intraoperative revision surgery in cases of late PJI; and whether there was a therapeutic consequence.

METHODS

A total of 508 patients who required revision surgery of total hip arthroplasty (THA) (n = 231) or total knee arthroplasty (TKA) (n = 277) because of component loosening underwent biopsy before revision surgery. The tissue samples collected at biopsy and during revision surgery were analyzed according to the criteria of the Musculoskeletal Infection Society (MSIS).

RESULTS

In total, 178 (113 THA, 65 TKA) were classified as infected. The biopsy procedure had a sensitivity of 93.8%, a specificity of 97.3%, a positive predictive value (PPV) of 94.9%, a negative predictive value (NPV) of 96.7%, and an accuracy of 96.1%. Of the 178 infected patients, 26 showed a difference in the detected bacteria from the biopsy and the revision surgery (14.6%). This difference required a change to antibiotic therapy in only two cases (1.1%).

CONCLUSION

Biopsy is a useful tool to diagnose PJI, but there may be a difference in the detected bacteria between the biopsy and revision surgery. However, this did not affect the choice of antibiotic therapy in most cases, rendering the clinical relevance of this phenomenon as low. Cite this article: Bone Joint J 2020;102-B(3):329-335.

C-reactive protein is not a screening tool for late periprosthetic joint infection

Background

Preoperative diagnosis of periprosthetic joint infection (PJI) is important because of the therapeutic consequences. The aim of the present study is to investigate whether the serum C-reactive protein (CRP) level can be used as a screening tool for late PJI.

Materials and methods

A cohort of 390 patients with revision surgery of total hip prostheses (200) or total knee prostheses (190) was assessed for late PJI by determining CRP serum level and performing preoperative aspiration with cultivation and intraoperative tissue analyses with cultivation and histologic examination, using the Musculoskeletal Infection Society (MSIS) and International Consensus Meeting (ICM) criteria.

Results

A total of 180 joints were rated as PJI (prevalence 46%). Of these, 42.8% (77) showed a CRP level below 10 mg/L and 28.3% (51) showed a normal CRP level of less than 5 mg/L. The 76.9% of the cases with slow-growing bacteria showed a CRP level below 10 mg/L, and 61.5% showed a normal CRP level.

Conclusions

Serum CRP level should not be used as a screening tool to rule out late PJI.

Level of evidence

Level 2 (diagnostic study).

The transfemoral approach for controlled removal of well-fixed femoral stems in hip revision surgery

BACKGROUND

For the removal of well fixed femoral stems, various standard and extended approaches are possible, all of which have their advantages and disadvantages. They should allow good visualization and avoid uncontrolled damage to the bone (especially devascularization and fractures) and to the musculature (especially the gluteus medius). As an extended approach we prefer the transfemoral approach in a modified Wagner technique. It is indicated for the controlled removal of broken endoprosthetic stems, a significantly thinned bone at risk of fracture, a stable cement mantle, a partially fixed cementless prosthetic stem with a coarse, rough surface, and infected, fixed total hip endoprostheses. In this review article we describe our experience with our technique of the transfemoral approach.

MATERIAL AND RESULTS

In 68 patients with hip revisions using the modified transfemoral approach, the Harris Hip Score increased continuously from 41.4 points preoperatively to 85.9 points 24 months postoperatively. The bony flap showed bone consolidation in 98.5% of cases. In 76 patients with transfemoral two-stage septic hip revisions, with closure of the flap around the interim prosthesis with cerclage wires and reopening of the flap during second stage revision, the Harris Hip Score was 62.2 ± 12.6 points before the replacement of the spacer and 86.6 ± 15.5 points two years after reimplantation. The healing rate of the bony flap after reimplantation was 98.7%, the absence of infection 93.4%, the rate of stem subsidence 6.6%, and the dislocation rate 6.6%; there was no aseptic loosening of the implants.

CONCLUSION

The transfemoral approach allows a reliable protection of the gluteus medius and the vastogluteal sling, and enables reproducibly good clinical outcomes.

Improving the improvisational pelvic circumferential compression technique for open-book pelvic fractures using a simulation model and a sphygmomanometer

BACKGROUND

Open-book pelvic fractures are associated with significant mortality. Emergency management may require a commercial pelvic circumferential compression device to reduce the fracture and compress haemorrhaging pelvic vasculature. Standard, commercial, twin-sized bedsheets are acceptable should commercial devices be unavailable. However, obese victims or personnel with insufficient body strength may impede successful reduction.

OBJECTIVE

To demonstrate the value of an improvisational windlass (intravenous pole) in improving the ability to reduce an open-book pelvic fracture.

METHODS

The Institutional Review Board-approved study involved 28 diverse healthcare students and emergency medicine residents. Each participant's demographic information and physical characteristics were recorded. A METIman was prepared with knee and ankle binding and a sphygmomanometer set at 40 mm Hg placed over the symphysis pubis. Two-person teams were randomly selected to place a bedsheet at greater trochanter level and atop the sphygmomanometer. The bedsheet was secured with maximum effort by the pairs and the pressure recorded. Following this, the pairs inserted an intravenous pole in the knot and torqued the pole to maximum effort and a repeat pressure recorded.

RESULTS

The mean increase in pressure using only the bedsheet was 106.43 mm Hg per team. With bedsheet and intravenous pole, the mean pressure increase was 351.79 mm Hg per team. The difference was statistically significant (independent samples t-test: t = 17.177, p < 0.001, 95% CI (216.65 to 274.07 mm Hg). There was no correlation between pressure increases and the individual physical characteristics of the subjects (r = - 0.183, p = 0.352).

CONCLUSIONS

Regardless of personnel's physical attributes, the addition of an improvisational windlass to a pelvic circumferential compression bedsheet can improve the ability to reduce an open-book fracture, especially in obese victims.

Fixation of a modular curved revision stem with a taper of 2° in the femur

INTRODUCTION

Modular revision stems with a short distal component can prevent the bypassing of the femoral isthmus and hereby theoretically have advantages concerning risk of periprosthetic fractures, breakage of the junction and a technically easier revision procedure.

MATERIALS AND METHODS

Radiological evaluation of 202 stem revision operations with the modular curved revision stem "Revitan Curved" with a 2° taper was carried out after a mean follow-up period of 7.44 ± 2.09 years (3-13 years) to investigate whether short-stem combinations are effective in Paprosky 2 and 3A defects with respect to rate of subsidence and loosening.

RESULTS

Sixty of 62 endofemoral (96.8%) and 137 of 140 transfemoral implantations (97.9%) involved the short, 140 mm distal component. Significant subsidence was seen in 3.3% of cases following endofemoral implantation and in 2.1% of cases following transfemoral implantation. Neither aseptic loosening nor periprosthetic fracture were observed.

CONCLUSION

The use of combinations of short modular components leads to reproducibly good outcomes in femoral revision with respect to subsidence and loosening.

Treatment of periprosthetic fractures of the knee using trabecular metal cones for stabilization

This report describes an operative technique for the treatment of periprosthetic fractures of the knee with instability of the metaphysis and the metadiaphyseal junction that stabilizes the metaphyseal fragment by a distraction technique using trabecular metal cones. Fifteen patients were examined clinically and radiologically for a follow-up period of 36.7 ± 8.7 months. The Knee Society Score improved to 73.2 ± 20.2 by 24 months after surgery; the function score improved to 68.3 ± 20.2 by 24 months after surgery. The mean flexion amounted to 94.4 ± 9.7 degrees by 24 months after surgery. The only complication was one case of thrombosis. This technique involving trabecular metal cones to stabilize metaphyseal fractures seems to represent a further option for fixation of periprosthetic fractures that are otherwise treated with megaprostheses.

One-stage exchange of septic shoulder arthroplasty following a standardized treatment algorithm

BACKGROUND

Studies on 1-stage exchange in septic shoulder arthroplasty are limited and show a wide variation of treatment strategies. This retrospective study investigated infection-free survival and function of 1-stage exchange of septic shoulder arthroplasty following a standardized treatment algorithm.

METHODS

The requirement for 1-stage exchange was an isolated microorganism from synovial fluid aspiration or synovial biopsy with an antibiotic susceptibility profile prior to revision surgery. If no microorganism was isolated or the underlying pathogen was a difficult-to-treat microorganism (not accessible for biofilm-active antibiotics, enterococci, and fungi), 2-stage exchange was performed. Function was assessed by the Constant score.

RESULTS

Fourteen patients were included, with a mean follow-up period of 5.8 years. The most and second most commonly detected microorganisms were Cutibacterium acnes (formerly Propionibacterium acnes), and Staphylococcus epidermidis, respectively. At 1-stage exchange, patients received local and systemic antibiotics based on the susceptibility profile of the microorganism. Twelve patients with insufficient rotator cuffs received reverse shoulder arthroplasty, whereas 2 patients with intact rotator cuffs underwent anatomic total shoulder arthroplasty. The infection-free survival rate at 1 and 5 years was 100% and 93% (95% confidence interval [CI], 59%-99%), respectively, with 1 recurrence of infection 22 months after 1-stage exchange. Another patient with limited range of motion underwent revision 6 months postoperatively, leading to a revision-free survival rate of 93% (95% CI, 59%-99%) and 86% (95% CI, 54%-96%) at 1 and 5 years, respectively. The mean Constant score was 65 (range, 44-95).

CONCLUSION

One-stage exchange with prior detection of the underlying microorganism provides satisfactory infection-free survival and function.

Standard and line-to-line cementation of a polished short hip stem: Long-term in vitro implant stability

The current trend is toward shorter hip stems. While there is a general agreement on the need for a cement mantle thicker than 2 mm, some surgeons prefer line-to-line cementation, where the mantle has only the thickness provided by the cement-bone interdigitation. The aim of this study was to assess if a relatively short, polished hip stem designed for a standard cementation can also be cemented line-to-line without increasing the risk of long-term loosening. Composite femurs with specific open-cell foam to allow cement-bone interdigitation were used. A validated in-vitro biomechanical cyclic test replicating long-term physiological loading was applied to femurs where the same stem was implanted with the Standard-mantle (optimal stem size) and Line-to-line (same rasp, one-size larger stem). Implant-bone motions were measured during the test. Inducible micromotions never exceeded 10 μm for both implant types (differences statistically not-significant). Permanent migrations ranged 50-300 μm for both implant types (differences statistically not-significant). While in the standard-mantle specimens there was a pronounced trend toward stabilization, line-to-line had less tendency to stabilize. The cement cracks were observed after the test by means of dye penetrants: The line-to-line specimens included the same cracks of the standard-mantle (but in the line-to-line specimens they were longer), and some additional cracks. The micromotions and cement damage were consistent with those observed in-vitro and clinically for stable stems, confirming that none of the specimens became dramatically loose. However, it seems that for this relatively short polished stem, standard-mantle cementation is preferable, as it results in less micromotion and less cement cracking. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2736-2744, 2018.

What can the surgeon do to reduce the risk of junction breakage in modular revision stems?

Modular revision stems are very common in hip arthroplasty, but junction fracture remains a known failure mechanism. A review of the literature with description of cases with junction breakage of modular revision stems showed that in all 24 analyzed cases, there was a common finding: the combination of an effective osteointegration of the distal component and missing medial bone support of the proximal component. The result was a bending stress point of the stem construction in the region of the junction. A technique using the combination of short distal component and longer proximal components may alter this stress pattern, allow proximal implant support, and reduce the risk of junction fracture. Moreover, filling of gaps between the modular component and the medial region of the femoral calcar in endofemoral implantation, a double osteotomy in significant bowed femurs, and treating medial bone defects with structural allografts additionally can reduce the risk of junction breakage.

The effect of skin surface topography and skin colouration cues on perception of male facial age, health and attractiveness

OBJECTIVE

Previous studies investigating the effects of skin surface topography and colouration cues on the perception of female faces reported a differential weighting for the perception of skin topography and colour evenness, where topography was a stronger visual cue for the perception of age, whereas skin colour evenness was a stronger visual cue for the perception of health. We extend these findings in a study of the effect of skin surface topography and colour evenness cues on the perceptions of facial age, health and attractiveness in males.

METHODS

Facial images of six men (aged 40 to 70 years), selected for co-expression of lines/wrinkles and discolouration, were manipulated digitally to create eight stimuli, namely, separate removal of these two features (a) on the forehead, (b) in the periorbital area, (c) on the cheeks and (d) across the entire face. Omnibus (within-face) pairwise combinations, including the original (unmodified) face, were presented to a total of 240 male and female judges, who selected the face they considered younger, healthier and more attractive.

RESULTS

Significant effects were detected for facial image choice, in response to skin feature manipulation. The combined removal of skin surface topography resulted in younger age perception compared with that seen with the removal of skin colouration cues, whereas the opposite pattern was found for health preference. No difference was detected for the perception of attractiveness. These perceptual effects were seen particularly on the forehead and cheeks. Removing skin topography cues (but not discolouration) in the periorbital area resulted in higher preferences for all three attributes.

CONCLUSION

Skin surface topography and colouration cues affect the perception of age, health and attractiveness in men's faces. The combined removal of these features on the forehead, cheeks and in the periorbital area results in the most positive assessments.

Treatment of Extensive Gluteus Muscle Tears With Transosseous Fixation and a Nonresorbable Collagen Patch

BACKGROUND

Extensive tearing of the gluteus muscles (spontaneous or subsequent to hip arthroplasty) is difficult to treat. We are carrying out osseous fixation with securement of the suture anchor by a nonresorbable collagen patch. The objective of this study is to examine the follow-up data of 30 patients and to assess whether the clinical outcomes depended on the extent of the fatty degeneration of the gluteus medius.

METHODS

Thirty patients (28 female and 2 male) with a mean age of 76.8 ± 4.3 years (68-83 years) were followed for a mean of 46.8 ± 23.1 months (24-101 months).

RESULTS

Pain improved significantly from a preoperative visual analog scale score of 7.0 ± 1.52 (6-10) to 0.83 ± 0.77 (0-3) 24-month postoperative. The gluteus medius muscle force increased from 2.09 ± 0.81 to 3.3 ± 0.78 using the British Medical Research Council Scale. All patients exhibited a severe limp before the operation. Postoperatively, only 5 patients had a severe limp, while 14 exhibited a mild limp and 11 no limp at all. The modified Harris Hip Score increased from a preoperative value of 44.5 ± 4.2 (26-66) to a value of 81.1 ± 7.79 (60-100) 24-month postoperative. The functional results were dependent on the level of fatty degeneration of the muscle.

CONCLUSION

The first results for this surgical technique appear to be very promising for the treatment of extensive tearing of the gluteus musculature that has a degree of fatty degeneration less than 75%.

[Therapy of Periprosthetic Shoulder Infection]

There are several therapeutic options for the treatment of periprosthetic joint infections of shoulder arthroplasties. In acute infections, the implant can remain in place with open debridement, septic lavage with antibacterial solutions such as octinedine or polyhexanide solution and exchange of all mobile components. In late infections, the therapeutic options after removal of the infected implant are: permanent spacer, resection arthroplasty, one stage revision and two stage revision with or without a temporary spacer. The functional results are best for one stage revisions, with similar prosthetic survival to two stage revisions. For one stage revisions, the microorganism has to be identified prior to revision surgery, in order to use targeted antibiotics locally in the cement, and systemically.

Single-stage Acetabular Revision During Two-stage THA Revision for Infection is Effective in Selected Patients

BACKGROUND

The treatment of periprosthetic infections of hip arthroplasties typically involves use of either a single- or two-stage (with implantation of a temporary spacer) revision surgery. In patients with severe acetabular bone deficiencies, either already present or after component removal, spacers cannot be safely implanted. In such hips where it is impossible to use spacers and yet a two-stage revision of the prosthetic stem is recommended, we have combined a two-stage revision of the stem with a single revision of the cup. To our knowledge, this approach has not been reported before.

QUESTIONS/PURPOSES

(1) What proportion of patients treated with single-stage acetabular reconstruction as part of a two-stage revision for an infected THA remain free from infection at 2 or more years? (2) What are the Harris hip scores after the first stage and at 2 years or more after the definitive reimplantation?

METHODS

Between June 2009 and June 2014, we treated all patients undergoing surgical treatment for an infected THA using a single-stage acetabular revision as part of a two-stage THA exchange if the acetabular defect classification was Paprosky Types 2B, 2C, 3A, 3B, or pelvic discontinuity and a two-stage procedure was preferred for the femur. The procedure included removal of all components, joint débridement, definitive acetabular reconstruction (with a cage to bridge the defect, and a cemented socket), and a temporary cemented femoral component at the first stage; the second stage consisted of repeat joint and femoral débridement and exchange of the femoral component to a cementless device. During the period noted, 35 patients met those definitions and were treated with this approach. No patients were lost to followup before 2 years; mean followup was 42 months (range, 24-84 months). The clinical evaluation was performed with the Harris hip scores and resolution of infection was assessed by the absence of clinical signs of infection and a C-reactive protein level less than 10 mg/L. All patients were assessed before surgery, between stages, every 3 months during the first year after surgery, every 6 months during the second year postoperative, and at latest followup, and were retrospectively drawn from a longitudinally maintained institutional database.

RESULTS

Thirty-four of 35 patients (97.2%; 95% CI, 85.4%-99.5%) appeared free of infection by criteria of Masri et al. and Zimmerli et al. at latest followup. The Harris hip score was 61 ± 13 points after the first operation and 82 ± 16 points 2 years after the second operation.

CONCLUSIONS

This technique is a promising treatment option for periprosthetic infections of the hip in which substantial acetabular defects exclude implantation of a normal spacer and a two-stage revision of the femoral component is favored.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

[Diagnosis of Periprosthetic Joint Infection of Shoulder Arthroplasties]

Periprosthetic joint infection of shoulder arthroplasties is one of the most frequent reasons for pain and revision surgery of shoulder arthroplasties. Propionibacterium acnes is one of the commonest microorganisms causing periprosthetic joint infection in shoulder arthroplasties. It is difficult to detect this slow growing microorganism. This paper gives an overview of the different diagnostic methods. A combination of unspecific and specific tests (detection of microorganism and sensitivity to antibiotics) is helpful in identifying a periprosthetic shoulder infection. Aspiration of the joint can combine different unspecific and specific tests. In patients with punctio sicca and suspected periprosthetic joint infection, we recommend biopsy of periprosthetic tissue.

A comparison of apixaban and dabigatran etexilate for thromboprophylaxis following hip and knee replacement surgery

INTRODUCTION

Patients who have undergone hip or knee replacement surgery are exposed to a high risk of developing a post-operative venous thromboembolus and so have a need for an effective, medication-based, thrombosis prophylaxis. New orally active anticoagulants have been available for a few years now. These specific substances directly block either thrombin (e.g., dabigatran etexilate) or Factor Xa (e.g., apixaban). It is not clear whether there are any efficacy differences between these two substances because there have never been any head-to-head studies carried out.

MATERIALS AND METHODS

We have carried out a study comparing two new orally active anticoagulants dabigatran etexilate (Pradaxa^®) and apixaban (Eliquis^®) that were each given to two groups of 200 patients respectively, who had undergone elective hip or knee arthroplasty (100 each). Each patient was assessed for pre- and post-operative hemoglobin concentrations, post-operative blood loss, the number of transfused erythrocyte concentrates, the duration of wound secretion, clinical thromboembolic complications (deep vein thrombosis, pulmonary embolism, myocardial infarct), as well as gastrointestinal, intracranial or wound-related bleeding complications.

RESULTS

Dabigatran etexilate treatment led to a significant increase in the duration of wound secretion in both arthroplasty groups when compared to apixaban: wound secretion lasted 1.2 days longer on average in the dabigatran etexilate group than in the apixaban group (4.1 ± 2.1 vs. 2.9 ± 1.8 days). There were no significant differences observed between the two anticoagulant groups when comparing pre- and post-operative Hb values, post-operative blood loss and the other clinical parameters.

CONCLUSIONS

Thus, it appears that the direct thrombin inhibitor, dabigatran etexilate, is associated with a longer period of wound secretion following the implantation of hip and knee endoprostheses than that associated with the Factor Xa inhibitor, apixaban.

Hip revision arthroplasty for failed osteosynthesis in periprosthetic Vancouver type B1 fractures using a cementless, modular, tapered revision stem

Aims

To evaluate the hypothesis that failed osteosynthesis of periprosthetic Vancouver type B1 fractures can be treated successfully with stem revision using a transfemoral approach and a cementless, modular, tapered revision stem with reproducible rates of fracture healing, stability of the revision stem, and clinically good results.

Patients and Methods

A total of 14 patients (11 women, three men) with a mean age of 72.4 years (65 to 90) undergoing revision hip arthroplasty after failed osteosynthesis of periprosthetic fractures of Vancouver type B1 were treated using a transfemoral approach to remove the well-fixed stem before insertion of a modular, fluted titanium stem which obtained distal fixation. These patients were clinically and radiologically followed up for a mean 52.2 months (24 to 144).

Results

After a mean of 15.5 weeks (standard deviation (sd) 5.7) all fractures had healed. No stems subsided and bony-ingrowth fixation had occurred according to the classification of Engh et al. The mean Harris Hip Score increased from a pre-operative score of 22.2 points (sd 9.7) to 81.5 points (sd 16.8) 24 months post-operatively. All hips had obtained an excellent result according to the classification of Beals and Tower.

Conclusions

The technique described here for stem revision provides reproducibly good results in the treatment of failed osteosynthesis for Vancouver types B1 periprosthetic fractures of the hip. Cite this article: Bone Joint J 2017;99-B(4 Supple B):11–16.

A Standardized Regimen for the Treatment of Acute Postoperative Infections and Acute Hematogenous Infections Associated With Hip and Knee Arthroplasties

BACKGROUND

Papers concerning the treatment of periprosthetic infections and acute hematogenous infections often concern inhomogeneous treatment concepts or low numbers of patients; this results in inconsistent rates of treatment success.

METHODS

Thirty-nine patients with early periprosthetic infections and 28 patients with acute hematogenous infections were treated with a homogeneous concept and followed with a mean period of 41.8 (24-132) months in order to investigate the success rate and influencing factors. All patients were treated with open surgical debridement, a revision of all removable components and irrigation with an antiseptic solution (octinedine). All patients received a systemic vancomycin/rifampicin antibiotic therapy until the microorganism causing the infection could be identified; a specific antibiotic therapy then followed until the end of the sixth week.

RESULTS

This unified treatment regimen resulted in an overall success rate of 71.6%, an 82.1% success for early infections and 57.1% for acute hematogenous infections. Variables that influenced the recurrence of an infection were the timespan between revision and first appearance of symptoms (<2 days), the number of previous operations, the American Society of Anesthesiologists classification, and nicotine abuse.

CONCLUSION

It appears that, in cases of early postoperative infection, a reproducibly high rate of success in retaining an implant can be achieved with this specific therapy regime if surgical intervention can be carried out within 2 days of first symptoms.

[Diagnostic Algorithm for Failure Analysis of Painful Total Hip Arthroplasties]

Background: Total hip arthroplasty (THA) is one of the most common and successful surgical procedures in orthopedic surgery and clinical success can be characterized by the revision rate and improvement of function, as well as the patient's satisfaction and pain. Despite the clinical success of primary THA with 10-year survival rates as high as 96 % (Swedish Hip Arthroplasty Register, 2011), the prevalence of groin pain after conventional total hip replacement ranges from 0.4 to 18.3 % and activity-limiting thigh pain is still an existing problem linked to the femoral component of uncemented hip replacement in up to 1.9 to 40.9 % of cases in some series. Obvious causes of failure might be identified with clinical examinations and standard radiographs only, whereas the unexplained painful THA still remains a challenge for the surgeon. They can be classified into extra- and intraarticular disorders, the latter being divided into biological and mechanical origins. The onset of the pain after the operation and the differentiation between pain in motion and at rest are helpful to distinguish between mechanical and non-mechanical problems. An infection should be the first diagnosis to be ruled out in a painful THA. It is generally accepted that a clear understanding of the failure mechanism in each case is required prior considering revision surgery. Method: In this review a practical diagnostic algorithm is described for failure analysis in more detail. The evaluation of a painful THA includes a detailed history with an extended analysis of the type of pain, thorough clinical examination including the spine and knee joints, radiographic and laboratory analysis, as well as invasive examinations like joint aspiration and biopsies. Conclusion: This diagnostic algorithm offers an important tool for a sufficient failure analysis in almost all patients with painful THA.

The Transfemoral Approach for Removal of Well-Fixed Femoral Stems in 2-Stage Septic Hip Revision

BACKGROUND

The value of a transfemoral approach for removal of well-fixed infected hip arthroplasties in 2-stage revision is unclear, especially whether cerclages for closure of the flap in the first step lead to higher reinfection rates and whether reopening of the flap for reimplantation of a hip arthroplasty leads to a lower union rate of the bony flap.

METHODS

Seventy-six septic 2-stage revisions via a transfemoral approach with cerclages for closure of the flap in the first step and reopening of the flap for reimplantation were followed prospectively for a mean period of 51.2 ± 23.2 (24-118) months.

RESULTS

The union rate of the bony flap after reimplantation was 98.7%, and no recurrence of reinfection was recorded in 93.4% of all cases. Subsidence of the stem occurred at a rate of 6.6%, dislocation at a rate of 6.6%, and there was no aseptic loosening of the implants. The Harris Hip Score was 62.2 ± 12.6 points with the spacer and 86.6 ± 15.5 points 2 years after reimplantation. Nine fractures (11.8%) of the flap occurred during the operation because of osteolytic or osteoporotic weakness of the flap itself, but these all healed without further intervention.

CONCLUSION

The transfemoral approach is a safe method for septic revision of well-fixed hip prostheses, and the use of cerclage wires for closing the osteotomy flap in the first stage does not appear to lead to a higher reinfection rate. Similarly, the reopening of the flap does not appear to decrease the union rate of the flap.

[Tripolar cups]

Tripolar cups can be separated into constrained and unconstrained dual-mobility cups. The latter show better survival and revision rates. The main problem is the polyethylene wear. Therefore modern types of polyethylene are used in these cups. The indications for dual-mobility cups are recurrent dislocation and situations where the risk of dislocation is increased.

Mid term results with the curved modular tapered, fluted titanium Revitan stem in revision hip replacement

We report our experience of revision total hip replacement (THR) using the Revitan curved modular titanium fluted revision stem in patients with a full spectrum of proximal femoral defects. A total of 112 patients (116 revisions) with a mean age of 73.4 years (39 to 90) were included in the study. The mean follow-up was 7.5 years (5.3 to 9.1). A total of 12 patients (12 hips) died but their data were included in the survival analysis, and four patients (4 hips) were lost to follow-up. The clinical outcome, proximal bone regeneration and subsidence were assessed for 101 hips. The mean Harris Hip Score was 88.2 (45.8 to 100) after five years and there was an increase of the mean Barnett and Nordin-Score, a measure of the proximal bone regeneration, of 20.8 (-3.1 to 52.7). Five stems had to be revised (4.3%), three (2.9%) showed subsidence, five (4.3%) a dislocation and two of 85 aseptic revisions (2.3%) a periprosthetic infection. At the latest follow-up, the survival with revision of the stem as the endpoint was 95.7% (95% confidence interval 91.9% to 99.4%) and with aseptic loosening as the endpoint, was 100%. Peri-prosthetic fractures were not observed. We report excellent results with respect to subsidence, the risk of fracture, and loosening after femoral revision using a modular curved revision stem with distal cone-in-cone fixation. A successful outcome depends on careful pre-operative planning and the use of a transfemoral approach when the anatomy is distorted or a fracture is imminent, or residual cement or a partially-secured existing stem cannot be removed. The shortest appropriate stem should, in our opinion, be used and secured with > 3 cm fixation at the femoral isthmus, and distal interlocking screws should be used for additional stability when this goal cannot be realised.

[Arthroplasty of the Femoropatellar Joint - What Data are Available?]

BACKGROUND

Osteoarthritis of the knee joints is rarely seen only in the femoropatellar joint. In isolated severe osteoarthritis of the femoropatellar joint an isolated prosthetic joint replacement of this joint is indicated. To achieve good results, correct patient selection with no arthritis in the femorotibial joint and absence of maltracking and instability of the patella are crucial. Modern prostheses with a femoral onlay component and a proper surgical technique with correct alignment of the prosthetic component and prevention of an overstuffing of the patella are essential.

PATIENTS AND METHODS

Fifty-three Vanguard Prostheses (Biomet GmbH, Warsaw, IL) were examined after a follow-up of 3.7 ± 2.8 (1-8) years.

RESULTS

The Knee Society score increased from 117.3 points preoperative to 181.2 points at the follow-up. One knee was revised because of neuropathic pain. Two patients suffered from periprosthetic patellar fractures after falling.

CONCLUSION

In well indicated cases with isolated osteoarthritis of the femoropatellar joint, good clinical results with a femoropatellar prosthesis can be expected.

Peri-conceptional obesogenic exposure induces sex-specific programming of disease susceptibilities in adult mouse offspring

Vulnerability of the fetus upon maternal obesity can potentially occur during all developmental phases. We aimed at elaborating longer-term health outcomes of fetal overnutrition during the earliest stages of development. We utilized Naval Medical Research Institute (NMRI) mice to induce pre-conceptional and gestational obesity and followed offspring outcomes in the absence of any postnatal obesogenic influences. Male adult offspring developed overweight, insulin resistance, hyperleptinemia, hyperuricemia and hepatic steatosis; all these features were not observed in females. Instead, they showed impaired fasting glucose and a reduced fat mass and adipocyte size. Influences of the interaction of maternal diet∗sex concerned offspring genes involved in fatty liver disease, lipid droplet size regulation and fat mass expansion. These data suggest that a peri-conceptional obesogenic exposure is sufficient to shape offspring gene expression patterns and health outcomes in a sex- and organ-specific manner, indicating varying developmental vulnerabilities between sexes towards metabolic disease in response to maternal overnutrition.

Peri-conceptional obesogenic exposure induces sex-specific programming of disease susceptibilities in adult mouse offspring

Vulnerability of the fetus upon maternal obesity can potentially occur during all developmental phases. We aimed at elaborating longer-term health outcomes of fetal overnutrition during the earliest stages of development. We utilized Naval Medical Research Institute (NMRI) mice to induce pre-conceptional and gestational obesity and followed offspring outcomes in the absence of any postnatal obesogenic influences. Male adult offspring developed overweight, insulin resistance, hyperleptinemia, hyperuricemia and hepatic steatosis; all these features were not observed in females. Instead, they showed impaired fasting glucose and a reduced fat mass and adipocyte size. Influences of the interaction of maternal diet∗sex concerned offspring genes involved in fatty liver disease, lipid droplet size regulation and fat mass expansion. These data suggest that a peri-conceptional obesogenic exposure is sufficient to shape offspring gene expression patterns and health outcomes in a sex- and organ-specific manner, indicating varying developmental vulnerabilities between sexes towards metabolic disease in response to maternal overnutrition.