We investigated the clinical and radiological outcome of trochleaplasty for recurrent patellar dislocation in association with trochlear dysplasia in 38 consecutive patients (45 knees) with a mean follow-up of 8.3 years (4 to 14). None had recurrence of dislocation after trochleaplasty. Post-operatively, patellofemoral pain, present pre-operatively in only 35 knees, became worse in 15 (33.4%), remained unchanged in four (8.8%) and improved in 22 (49%). Four knees which had no pain pre-operatively (8.8%) continued to have no pain. A total of 33 knees were available for radiological assessment. Post-operatively, all but two knees (93.9%) had correction of trochlear dysplasia radiologically but degenerative changes of the patellofemoral joint developed in 30% (10) of the knees. We conclude that recurrent patellar dislocation associated with trochlear dysplasia can be treated successfully by trochleaplasty, but the impact on patellofemoral pain and the development of patellofemoral osteoarthritis is less predictable. Overall, subjective patient satisfaction with restored patellofemoral stability after trochleaplasty appeared to outweigh its possible sequelae.

The majority of patients returned to sports and recreational activity after unicompartmental knee arthroplasty. However, the numbers of different disciplines patients were engaged in decreased as well as the extent of activities. The activities in which most patients participated were primarily low- or midimpact. The patients scored higher on the SF-36 than age-related norms, which might be due to the patient-selection process for unicompartmental knee arthroplasty and geographical differences.

No abstract

The German version of the OKS is a reliable and valid measure for the self-assessment of pain and function in German-speaking patients with osteoarthritis of the knee.

Background Retention treatment is reportedly associated with lower infection control rates than two-stage revision. However, the studies on which this presumption are based depend on comparisons of historical rather than concurrent controls. Questions/purposes We (1) asked whether the infection control rates, number of additional procedures, length of hospital stay, and treatment duration differed between implant retention and two-stage revision treatment; and (2) identified risk factors that can contribute to failure of infection control. Methods We reviewed the records of 60 patients treated for 64 infected TKA from 2002 to 2007. Twenty-eight patients (32 knees) underwent débridement with retention of component, and 32 patients (32 knees) were treated with component removal and two-stage revision surgery. We determined patients' demographics, type of infection, causative organisms, and outcome of treatment. Mean followup was 36 months (range, 12-84 months). Results Infection control rate was 31% in retention and 59% in the removal group after initial surgical treatment, and 81% and 91% at latest followup, respectively. Treatment duration was shorter in the retention group and there was no difference in number of additional surgeries and length of hospital stay. Type of treatment (retention versus removal) was the only factor associated with infection control; subgroup analysis in the retention group showed Staphylococcus aureus infection and polyethylene nonexchange as contributing factors for failure of infection control. Conclusions Although initial infection control rate was substantially lower in the retention group than the removal group, final results were comparable at latest followup. We believe retention treatment can be selectively considered for non-S. aureus infection, and when applied in selected patients, polyethylene exchange should be performed. Level of Evidence Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Background The direct anterior approach for THA allows implantation through an internervous plane without muscle detachment from bone. However, the classic longitudinal skin incision does not follow the anatomic skin creases and can result in scar widening. We therefore modified our incision technique to a short oblique skin incision following the anatomic skin crease of the groin.Questions/purposes We sought to determine whether (1) the oblique incision leads to improved scar results compared with the longitudinal incision, (2) functional and pain scores are similar between the two approaches, and (3) the new incision is safe with respect to complications, blood loss, implant position, and lateral femoral cutaneous nerve (LFCN) symptoms. Methods Fifty-nine patients underwent THAs using either the classic (n = 33) or the new oblique incision (n = 26). At 6 months after surgery, we compared objective and subjective scar results, WOMAC, Oxford Hip and UCLA scores, blood loss, cup inclination, and the presence of LFCN symptoms between both groups.

Small-animal models are useful for the in vivo study of particle-induced osteolysis, the most frequent cause of aseptic loosening after total joint replacement. Microstructural changes associated with particle-induced osteolysis have been extensively explored using two-dimensional (2D) techniques. However, relatively little is known regarding the 3D dynamic microstructure of particle-induced osteolysis. Therefore, we tested micro-computed tomography (micro-CT) as a novel tool for 3D analysis of wear debris-mediated osteolysis in a small-animal model of particle-induced osteolysis. The murine calvarial model based on polyethylene particles was utilized in 14 C57BL/J6 mice randomly divided into two groups. Group 1 received sham surgery, and group 2 was treated with polyethylene particles. We performed 3D micro-CT analysis and histological assessment. Various bone morphometric parameters were assessed. Regression was used to examine the relation between the results achieved by the two methods. Micro-CT analysis provides a fully automated means to quantify bone destruction in a mouse model of particle-induced osteolysis. This method revealed that the osteolytic lesions in calvaria in the experimental group were affected irregularly compared to the rather even distribution of osteolysis in the control group. This is an observation which would have been missed if histomorphometric analysis only had been performed, leading to false assessment of the actual situation. These irregularities seen by micro-CT analysis provide new insight into individual bone changes which might otherwise be overlooked by histological analysis and can be used as baseline information on which future studies can be designed.

We investigated the clinical and radiological outcome after unilateral fracture of the lateral process of the talus in 23 snowboarders with a mean follow-up of 3.5 years (12 to 76 months). In this consecutive cohort study both operative and non-operative cases were considered.The mean American Orthopaedic Foot and Ankle Society hindfoot score was 94 (82 to 100). The non-operative group of seven with a minimally-displaced fracture scored higher (98 points) than the operative group of 16 with displaced or unstable fractures (93 points). In 88% of operative cases, significant concomitant hindfoot injuries were found at operation. All but eight (35%) patients (six operative and two non-operative) regained their pre-injury level of sporting activity. Subtalar osteoarthritis was present in nine (45%) of the 20 patients available for radiological review, including one late-diagnosed non-operative case and eight operative cases with associated injuries or fracture comminution.The outcome after fracture of the lateral process of the talus in snowboarders is favourable provided an early diagnosis is made and adequate treatment, which is related to the degree of displacement and associated injuries, is undertaken.The lateral process of the body of the talus is a broad-based wedge-shaped prominence that articulates dorsolaterally with the fibula and inferomedially with the os calcis, thereby forming the lateral part of the subtalar joint.