[Successful medial unicompartmental knee arthroplasty-What are the most important surgical tricks?].

Background: Unicompartmental knee arthroplasty (UKA) is an established surgical treatment option for end-stage anteromedial osteoarthritis with excellent functional outcomes and implant survival. Routine preoperative varus and valgus stress views are crucial for the selection of patients for unicompartmental or total knee arthroplasty.

Therapy: UKA is a soft-tissue based operation that aims to reconstruct the individual joint line and pre-arthritic alignment by restoring the physiological tension of the medial collateral and the cruciate ligaments.

[New technologies (robotics, "custom-made") for unicondylar knee arthroplasty-contra].

Background: Numerous long-term results for both medial and lateral unicondylar knee arthroplasty (UKA) demonstrate that UKA is a reliable and successful treatment for isolated anteromedial or lateral osteoarthritis of the knee when the correct indications are used. The relationship between operation volume and implant performance has clearly been established from recent studies and registry data. The use of novel technologies allows for an improvement in the accuracy of implant positioning with fewer outliers.

High Variability of Acetabular Offset in Primary Hip Osteoarthritis Influences Acetabular Reaming-A Computed Tomography-Based Anatomic Study.

Background: The objectives of the present study were to (1) evaluate the accuracy and reliability of native acetabular offset (AO) measurements performed on conventional supine anterior-posterior (ap) pelvis radiographs with reference to computed tomography (CT) in patients with end-stage hip osteoarthritis (OA); (2) determine the minimum and maximum amount of medialization of the center of rotation (COR) simulating different reaming techniques; and (3) identify patients at increased risk of excessive medialization of the COR.

Methods: A consecutive series of corresponding 131 CT scans and radiographs of patients with primary hip OA was evaluated using validated software for three-dimensional acetabular and femoral measurements. We simulated the implantation of a hemispherical press-fit cup comparing anatomic and conventional reaming techniques and assessed corresponding changes in AO.

Size of ischial fibro-ostosis is associated with heterotopic ossification after total hip arthroplasty.

Purpose: The hypothesis of the present study was that degenerative fibro-ostosis (FO) of the ischial hamstring tendon insertion is a risk factor for heterotopic ossification (HO) following THA.

Methods: We followed 103 consecutive patients (43 males, 60 females, mean age 61 years) who underwent unilateral cementless THA for primary hip osteoarthritis and investigated the incidence of HO within the first 12 months after surgery. On pre-operative radiographs, a standardized evaluation for FO of the ischial hamstring tendon insertion concerning horizontal, vertical, and square dimensions was performed.

Comparative Analysis of the Reconstruction of Individual Hip Anatomy Using 3 Different Cementless Stem Designs in Patients With Primary Hip Osteoarthritis.

Background: We questioned whether there was a radiographic difference in hip geometry reconstruction and implant fixation between 3 different cementless stem design concepts in patients with primary end-stage hip osteoarthritis.

Methods: We retrospectively evaluated the preoperative and postoperative radiographs by 2 independent and blinded reviewers in a series of 264 consecutive patients who had received either a straight double-tapered stem with 3 offset options (group A), a straight double-tapered stem with 2 shape options and modular necks (group B), and a bone-preserving curved tapered stem with 4 offset options (group C). The following parameters were assessed: acetabular, femoral and hip offset (HO), center of rotation height, leg length difference (LLD), and the endosteal fit of stem in the proximal femur (canal fill index).

Influence of surgical approach on component positioning in primary total hip arthroplasty.

Background: Minimal invasive surgery (MIS) has gained growing popularity in total hip arthroplasty (THA) but concerns exist regarding component malpositioning. The aim of the present study was to evaluate femoral and acetabular component positioning in primary cementless THA comparing a lateral to a MIS anterolateral approach.

Methods: We evaluated 6 week postoperative radiographs of 52 hips with a minimal invasive anterolateral approach compared to 54 hips with a standard lateral approach.

Minimally invasive Oxford medial unicompartmental knee arthroplasty in young patients.

Purpose: Advanced knee arthritis in young patients is a challenging problem that may necessitate surgical treatment. There are few published studies of mobile-bearing unicompartmental knee arthroplasty (UKA) in young patients, while indications have expanded to its use in this demanding patient group.

Methods: The clinical and radiographic results of the first 118 consecutive Oxford medial UKAs (OUKA) using a minimally invasive technique (phase 3) in 101 patients 60 years of age or younger at the time of surgery were evaluated.

Minimum ten-year results of a 28-mm metal-on-metal bearing in cementless total hip arthroplasty in patients fifty years of age and younger.

Purpose: Concerns have been raised in relation to metal-on-metal (MoM) articulations with catastrophic soft-tissue reactions due to metal debris. We reviewed how small head MoM articulations perform in primary uncemented total hip arthroplasty (THA) in young patients at a minimum of ten years.

Methods: We retrospectively evaluated the clinical and radiographic results of the first 100 consecutive primary cementless THAs using the 28-mm Metasul MoM articulation in 91 patients younger than 50 years of age at the time of surgery.

Comparison of native anatomy with recommended safe component orientation in total hip arthroplasty for primary osteoarthritis.

Background: The adverse consequences of impingement, dislocation, and implant wear have stimulated increasing interest in accurate component orientation in total hip arthroplasty and hip resurfacing. The aims of the present study were to define femoral and acetabular orientation in a cohort of patients with primary hip osteoarthritis and to determine whether the orientation of their native hip joints corresponded with established recommendations for implantation of prosthetic components.

Methods: We retrospectively evaluated a consecutive series of 131 preoperative computed tomography (CT) scans of patients with primary end-stage hip osteoarthritis (fifty-seven male and seventy-four female patients; mean age, sixty years).

Proximal femoral canal shape is more accurately assessed on AP hip radiographs than AP pelvis radiographs in primary hip osteoarthritis.

The objectives of the present study were to determine whether differences in the radiographic appearance of the of the proximal femoral canal exist on corresponding AP pelvis and AP hip radiographs, and whether radiographic assessment of canal shape is accurate with reference to computed tomography (CT). In a retrospective study, corresponding radiographs and CT scans of 100 consecutive patients with primary hip OA were evaluated. Active shape modelling (ASM) was performed to assess the variation in proximal femoral canal shape and to identify differences between AP hip and AP pelvis views.

Long-term (20- to 25-year) results of an uncemented tapered titanium femoral component and factors affecting survivorship.

Background: Uncemented femoral components in primary total hip arthroplasty (THA) are commonly used today, but few studies have evaluated their survival into the third decade.

Questions/purposes: We evaluated (1) survivorship using femoral revision for any reason as the end point; (2) survivorship using femoral revision for aseptic loosening as the end point; and (3) patient-related and surgical risk factors for aseptic stem loosening at a minimum 20-year followup with an uncemented tapered titanium stem.

Methods: We reviewed the clinical and radiographic results of 354 THAs in 326 patients performed between January 1985 and December 1989 using an uncemented grit-blasted, tapered titanium femoral stem.

Influence of surgical approach on postoperative femoral bone remodelling after cementless total hip arthroplasty.

We retrospectively evaluated the femoral periprosthetic bone mineral density (BMD) in a consecutive series of patients who had undergone total hip arthroplasty (THA) with a straight, double tapered cementless stem using a muscle-sparing anterolateral (group A) and the transgluteal (group B) surgical approach. Dual-energy x-ray absorptiometry (DXA) measurements were performed in the first postoperative week (t1), and after 3 (t2), 6 (t3) and 12 months (t4) using an identical protocol. Patients were clinically and radiographically evaluated at final follow-up (t4).

Long-term results of cementless femoral reconstruction following intertrochanteric osteotomy.

Purpose: The objective of this retrospective cohort study was to assess the long-term outcome of cementless femoral reconstruction in patients with previous intertrochanteric osteotomy (ITO).

Methods: We evaluated the clinical and radiographic results of a consecutive series of 45 patients (48 hips, mean age 50 years) who had undergone conversion hip replacement following ITO with a cementless, grit-blasted, double-tapered femoral component. Clinical outcome was determined using the Harris hip score.

High survival in young patients using a second generation uncemented total hip replacement.

Purpose: Whilst excellent long-term results with contemporary uncemented stems have been reported for total hip arthroplasty in young patients, the survival rates for the whole reconstruction are often compromised by high failure rates on the acetabular site due to peri-acetabular osteolysis and accelerated wear.

Methods: In patients 60 years old or younger, we retrospectively reviewed the results at a minimum of ten years of 89 consecutive uncemented total hip replacements in 88 patients using the press-fit Fitmore acetabular component in combination with the CLS Spotorno stem and a 28-mm Metasul metal-on-metal articulation or a 28-mm alumina ceramic on conventional polyethylene bearing. The mean age at the time of surgery was 49 years (range, 25-60).

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.

A stature-specific concept for uncemented, primary total hip arthroplasty.

Background And Purpose: Variations in hip anatomy limit the femoral canal fit of standard uncemented hip stems. In addition, there are still issues with leg length discrepancy and offset reconstruction, potentially resulting in impingement, dislocation, and wear. Modular stems with different shapes for femoral canal fit and multiple neck options may improve the outcome and reduce complications.

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.

Custom stems for femoral deformity in patients less than 40 years of age: 70 hips followed for an average of 14 years.

Background And Purpose: Femoral deformity associated with osteoarthritis is a challenge for both the surgeon and the implant. Many of the patients with these deformities are young. Standard implants can be difficult to fit into these femurs.

Survival of the cementless Spotorno stem in the second decade.

High survival rates have been reported for the uncemented CLS Spotorno stem up to 10 years. To confirm survival at longer followup we report the minimum 15-year (mean, 17 years; range, 15-20 years) for 257 hips using this stem. We retrospectively evaluated the clinical and radiographic results of all 326 patients (354 THAs) operated between 1985 and 1989.

Uncemented grit-blasted straight tapered titanium stems in patients younger than fifty-five years of age. Fifteen to twenty-year results.

Background: Total hip arthroplasty without cement is frequently performed in young active patients, but only limited outcomes data are available after durations of follow-up of more than fifteen years.

Methods: We retrospectively evaluated the clinical and radiographic results of a consecutive series of 154 total hip arthroplasties (in 141 patients) performed with an uncemented grit-blasted straight tapered titanium femoral stem combined with a threaded socket in patients under the age of fifty-five years. The median duration of follow-up was seventeen years.

Complications in shoulder arthroplasty: an analysis of 485 cases.

The aim of this study was to analyse the complication rates of six different shoulder arthroplasty concepts for different diagnoses in the short and midterm. The study included 485 primary shoulder arthroplasties. The mean follow-up of the cohort was 3.

Long-term results of hip arthroplasty in ambulatory patients with cerebral palsy.

Osteoarthritis (OA) secondary to dislocation and dysplasia is a common problem in patients with cerebral palsy. The purpose of this study was to evaluate the results of total hip replacement (THR) in ambulatory patients with cerebral palsy. Eighteen total hip arthroplasties were performed in 16 ambulatory patients with cerebral palsy.