[Dealing with early complications in unicondylar knee arthroplasty-what works, what does not?].

Complications in the early postoperative period following the implantation of a unicondylar knee arthroplasty (UKA) are both rare and rarely described in the literature. Often, only small case series or individual case reports are available. In this article, the most common complications of periprosthetic infection, periprosthetic tibial fracture, inlay dislocation and intra-articular cement residue in (loose bone cement body) are described and recommendations for conservative and surgical treatment are presented, including case examples.

Time-Dependent Prediction Models for Individual Prognosis of Chronic Postsurgical Pain following Knee Replacement Based on an Extensive Multivariable Data Set.

(1) Background: Clinically useful prediction models for chronic postsurgical pain (CPSP) in knee replacement (TKA) are lacking. (2) Methods: In our prospective, multicenter study, a wide-ranging set of 91 variables was collected from 933 TKA patients at eight time points up to one year after surgery. Based on this extensive data pool, simple and complex prediction models were calculated for the preoperative time point and for 6 months after surgery, using least absolute shrinkage and selection operator (LASSO) 1se and LASSO min, respectively.

Combined treatment with medial unicompartmental knee arthroplasty and anterior cruciate ligament reconstruction is effective on long-term follow-up.

Purpose: The purpose of the present study was to evaluate the long-term outcome of combined medial unicompartmental knee arthroplasty (UKA) and anterior cruciate ligament reconstruction (ACLR). The authors hypothesized that the combined procedure leads to good long-term outcome in patients with isolated medial knee osteoarthritis (OA) and anterior cruciate ligament (ACL) deficiency.

Methods: Twenty-three patients with ACL deficiency and concomitant medial knee OA were treated from 2008 to 2016 with a combined UKA (Oxford Partial Knee) and ACLR using a hamstring tendon autograft.

[Pain therapy and anaesthesiological procedures in fast-track arthroplasty].

Since the introduction of fast-track surgery in the field of arthroplasty, all disciplines involved have been challenged with the task of close and continuous joint communication in the context of daily routine care. Processes that have been agreed upon interdisciplinarily must be reviewed at regular intervals, and, if necessary, adapted and newly agreed upon with the aim of optimizing the perioperative risks both medically and along the therapeutic pathway. The responsibility of the anaesthesiologist is not only limited to the performance of anaesthesia, but also includes the care of patients with a view to optimal pain therapy, maintenance of homeostasis and ensuring a rapid return of the patient's self-determination.

[Discharge readiness versus discharge-Results of the PROMISE study].

Background: In the context of optimized treatment processes for knee and hip replacements, lengths of stay are given for Germany that clearly exceed the internationally published ones. In this context, the present analysis of data from the PROMISE study deals with the relationship between discharge readiness and discharge.

Methods: In the PROMISE study, a jointly developed, optimized standard of care was established in three hospitals of different levels of care and realized for a typical, largely unselected cohort of patients.

The Migration Pattern of a Cementless Hydroxyapatite-Coated Titanium Stem under Immediate Full Weight-Bearing-A Randomized Controlled Trial Using Model-Based RSA.

(1) Background: High primary stability is important for the long-term survival of cementless femoral stems in total hip arthroplasty (THA). The objective of this study was to investigate the migration pattern of a hydroxyapatite-coated cementless hip stem developed for minimally invasive surgery using model-based radiostereometric analysis (RSA). (2) Methods: In this randomized controlled trial, 44 patients with an indication for cementless primary THA were randomly allocated to receive either the SL-PLUS MIA stem, developed for minimally invasive surgery, or the SL-PLUS stem (Smith & Nephew Orthopaedics, Baar, Switzerland) which served as a control group.

Sports activities before and after medial unicompartmental knee arthroplasty using the new Heidelberg Sports Activity Score.

Purpose: The purpose of our study was to investigate the change of sports activities before and after medial unicompartmental knee arthroplasty (UKA) with the use of the Heidelberg Sports Activity Score (HAS).

Methods: The Heidelberg Sports Activity Score (HAS) as well as FFb-H-OA, Oxford-12-Score, Tegner, UCLA and ACS were carried out to assess sports activities in 157 patients with medial osteoarthritis of the knee joint before and after UKA. The newly developed HAS also records the important duration and the sporting activity.

The protective effect of pulsed lavage against implant subsidence and micromotion for cemented tibial unicompartmental knee components: an experimental cadaver study.

Cemented UKAs were performed in 12 pairs of human cadaver legs and the bone bed was cleansed using pulsed lavage (group A) and conventional syringe lavage (group B). Subsidence and micromotion of the loaded tibial trays were measured. There was a significant effect of BMD on subsidence (P = 0.

Tibial cementing in UKA: a three-dimensional analysis of the bone cement implant interface and the effect of bone lavage.

Loosening is a common cause for revision in cemented UKA. In a cadaver study, we analyzed the three-dimensional cement distribution under the tibial implant and the effect of bone lavage (pulsed lavage, syringe lavage) on maximum cement penetration and penetration volume. Analyses were determined by performing bone cuts in medio-lateral direction and converting this data into a 3D model.

The influence of the femoral force application point on tibial cementing pressure in cemented UKA: an experimental study.

Background: Aseptic loosening is the major cause for implant failure in cemented unicompartmental knee arthroplasty (UKA). Central positioning of the femoral pressure during the tibial cementation process is recommended to achieve equal pressure and a good cementation result. The aim of this study was to verify the central position of the femoral force application point (FFAP) at 45° flexion of the knee and to investigate the influence of ligament tension and cement penetration pressure (CPP) for UKA.

Are patients' expectations of hip and knee arthroplasty fulfilled? A prospective study of 130 patients.

Total hip arthroplasty (THA) is the most successful procedure in orthopedic and trauma surgery. Patients' expectations of joint replacement surgery prior to and after the procedure are often discounted. This study investigated the expectations of patients before and 3 years after THA or total knee arthroplasty (TKA).

Ten-year survival of the cemented MS-30 femoral stem: increased revision rate in male patients.

This retrospective study evaluated the clinical and radiographic results of 337 consecutive matte surfaced, straight cemented MS-30 femoral stems implanted with first -to second-generation cementing technique. The median age of the patients at time of surgery was 72 (27-91) years. The median duration of follow-up was 10 (0.

Influence of bone density on the cement fixation of femoral hip resurfacing components.

In clinical outcome studies, small component sizes, female gender, femoral shape, focal bone defects, bad bone quality, and biomechanics have been associated with failures of resurfacing arthroplasties. We used a well-established experimental setup and human bone specimens to analyze the effects of bone density on cement fixation of femoral hip resurfacing components. Thirty-one fresh frozen femora were prepared for resurfacing using the original instruments.

The UniSpacer™: correcting varus malalignment in medial gonarthrosis.

While options for operative treatment of leg axis varus malalignment in patients with medial gonarthrosis include several established procedures, such as unicompartmental knee arthroplasty (UKA), total knee arthroplasty (TKA) or high tibial osteotomy (HTO), there has been little focus on a less invasive option introduced more recently: the UniSpacer™ implant, a self-centering, metallic interpositional device for the knee. This study evaluates clinical and radiological results of the UniSpacer™, whether alignment correction can be achieved by UniSpacer™ arthroplasty and alignment change in the first five postoperative years. Anteroposterior long leg stance radiographs of 20 legs were digitally analysed to assess alignment change: two relevant angles and the deviation of the mechanical axis of the leg were analysed before and after surgery.

Correlation of positioning and clinical results in Oxford UKA.

In a prospective clinical study, 59 patients with anteromedial osteoarthritis of the knee (61 knee joints) underwent minimally invasive medial Oxford unicompartmental arthroplasty phase 3. Clinical and radiographic examinations of 56 knees were carried out at five (4-7) years. American Knee Society (AKS) scores improved from mean 45.

Long-term results of the threaded Mecron cup in primary total hip arthroplasty : A 15-20-year follow-up study.

In the 1970s, high failure rates of cemented acetabular components, especially in young patients, in the middle- and long-term prompted a search for alternatives. The Mecring was one of the most popular first generation uncemented, threaded cups widely used in the 1980s for arthroplasty of the hip. First generation threaded cups commonly had smooth surface treatment and showed unacceptably high failure rates in the mid-term.

Long-term results of the threaded Weill cup in primary total hip arthroplasty: a 15-20-year follow-up study.

Uncemented, threaded acetabular components with smooth surface treatment were widely used in continental Europe in the 1970s and 1980s for primary total hip arthroplasty (THA). Previously published studies showed high failure rates in the mid-term. In a consecutive series of 116 patients, 127 threaded cups with smooth surface treatment (Weill cup; Zimmer, Winterthur, Switzerland) were implanted in combination with one type of uncemented stem.

Fracture load for periprosthetic femoral fractures in cemented versus uncemented hip stems: an experimental in vitro study.

This cadaveric study examined fracture loads in cemented and uncemented hip stems. Additionally, individual data and bone quality were analyzed and correlated to fracture patterns and fracture load. Cemented or uncemented hip stems were implanted in a randomized fashion in 10 matched paired fresh-frozen femora (donor median age, 78 years, and donor median weight, 74.

Pulsed lavage reduces the incidence of radiolucent lines under the tibial tray of Oxford unicompartmental knee arthroplasty: pulsed lavage versus syringe lavage.

The aim of the study was to determine whether the incidence of radiolucencies can be reduced using pulsed lavage before cementing the tibia in unicompartmental knee arthroplasty (UKA). We prospectively studied a consecutive series of 112 cemented Oxford UKA in 100 patients in two centres. In group A (n = 56) pulsed lavage and in group B (n = 56) conventional syringe lavage was used to clean the cancellous bone.

Saw cuts in unicompartmental knee arthroplasty: an analysis of Sawbone preparations.

Unicompartmental knee arthroplasty (UKA) has become a frequently used treatment option for anteromedial osteoarthritis (OA) of the knee due to good clinical and functional results. However, serious complications like tibial plateau fractures have been reported. These can be associated with saw cuts during surgery.

Determining knee joint alignment using digital photographs.

The objective of this work is to find out how reliably knee joint alignment can be measured from a standardized photograph and what influence changes in the standing position have on the angles measured. The interrater, intrarater, and test-retest reliability were evaluated. The influence of image-object distance, the distance between the legs and leg rotation on the measured angles was evaluated.