Three-Year Rates of Reoperation and Revision Following Mobile Versus Fixed-Bearing Total Ankle Arthroplasty: A Cohort of 302 Patients with 2 Implants of Similar Design.

BACKGROUND: Currently, the implants utilized in total ankle arthroplasty (TAA) are divided between mobile-bearing 3-component and fixed-bearing 2-component designs. The literature evaluating the influence of this mobility difference on implant survival is sparse. The purpose of the present study was therefore to compare the short-term survival of 2 implants of similar design from the same manufacturer, surgically implanted by the same surgeons, in fixed-bearing or mobile-bearing versions. METHODS: All patients were enrolled who underwent TAA with either the mobile-bearing Salto (Tornier and Integra) or the fixed-bearing Salto Talaris (Integra) in 3 centers by 2 surgeons between January 2004 and March 2018. All patients who underwent TAA from January 2004 to April 2013 received the Salto implant, and all patients who underwent TAA after November 2012 received the Salto Talaris implant. The primary outcome was time, within 3 years, to first all-cause reoperation, revision of any metal component, and revision of any component, including the polyethylene insert. Secondary outcomes included the frequency, cause, and type of reoperation. RESULTS: A total of 302 consecutive patients were included, of whom 171 received the mobile-bearing and 131 received the fixed-bearing implant. The adjusted hazard ratio for all-cause reoperation was 1.42 (95% confidence interval [CI], 0.67 to 3.00; p = 0.36); for component revision, 3.31 (95% CI, 0.93 to 11.79; p = 0.06); and for metal component revision, 2.78 (95% CI, 0.58 to 13.33; p = 0.20). A total of 31 reoperations were performed in the mobile-bearing group compared with 14 in the fixed-bearing group (p = 0.07). More extensive reoperation procedures were performed in the mobile-bearing group. CONCLUSIONS: With the largest comparison of 2 implants of similar design from the same manufacturer, the present study supports the use of a fixed-bearing design in terms of short-term failure. We found a 3-times higher rate of revision among mobile-bearing implants compared with fixed-bearing implants at 3 years after TAA. Reoperations, including first and subsequent procedures, tended to be less common and the causes and types of reoperations less extensive among fixed-bearing implants. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Mapping existing hip and knee replacement registries in Europe.

The general shortage of evidence regarding benefits and harms of medical devices has been highlighted following the serious safety concerns with metal-on-metal hip replacements and silicone breast implants and was again pointed out in a recent survey of European Health Technology Assessment institutions. In this context the new European medical device regulation will enforce post-marketing surveillance of existing and new implants. The usefulness of registry data as a source of information for medical device real-world clinical performance and safety has been demonstrated. However, these data might be under-used by researchers and policy makers. One reason for this is the insufficient awareness of their existence. The aim of this review is to provide information to relevant stakeholders on the extent and breadth of the data currently collected in European joint replacement registries. We identified 24 registries, most of them of national coverage. Total numbers of primary total hip and knee replacements included were over 3.1 and 2.5 million records, respectively. The current focus of these registries is on whole-lifespan implant surveillance via revision rate monitoring, quality assessment of surgical and perioperative care, and hospital performance assessment. More recently, national and international comparison and benchmarking have increasingly become part of their endeavors.

Radiographic evaluation of posttraumatic osteoarthritis of the ankle: the Kellgren-Lawrence scale is reliable and correlates with clinical symptoms.

OBJECTIVE: To assess reliability and construct validity of the Kellgren-Lawrence (K&L) scale in posttraumatic ankle osteoarthritis (OA); additionally evaluate the validity of including tibiotalar tilting in the scale. METHOD: One-hundred and fifty ankle radiographs (75 patients, unilateral malleolar fractures) evaluated at average of 18 years after surgery. American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot (HF) score and pain (visual analog scale) were recorded. Grading of OA according to K&L criteria and identification of OA features was performed on standardized radiographs by four physicians. Minimal joint space width, sclerosis, and talar tilt angle were quantified by digital measurements. A modified K&L scale including talar tilting is presented. Validity of original and modified scale was evaluated and expressed as ability to (1) Identify those with clinical symptoms of ankle OA; and (2) Distinguish between different degrees of fracture severity. RESULTS: Inter- and intra-observer reliability of OA assessment according to K&L were good (ICC 0.61 and 0.75). Original and modified K&L grades significantly increased with decreasing AOFAS ankle-HF scores and greater pain. A talar-tilt angle > 2° compared with ≤ 2° in grade 3 was associated with significantly higher pain levels (VAS pain 4.2 vs 1.4, respectively; mean difference 2.8, 95% CI 0.5-5.1). More severe fracture patterns at time of surgery were more often in patients with the highest K&L grades. CONCLUSIONS: The K&L scale is a valid and reliable radiographic grading system for assessment of ankle OA. Inclusion of the talar tilt angle might allow for better differentiation with respect to clinical outcomes.

A comparative assessment of small-head metal-on-metal and ceramic-on-polyethylene total hip replacement.

Large-head metal-on-metal (MoM) total hip replacements (THR) have given rise to concern. Comparative studies of small-head MoM THRs over a longer follow-up period are lacking. Our objective was to compare the incidence of complications such as infection, dislocation, revision, adverse local tissue reactions, mortality and radiological and clinical outcomes in small-head (28 mm) MoM and ceramic-on-polyethylene (CoP) THRs up to 12 years post-operatively. A prospective cohort study included 3341 THRs in 2714 patients. The mean age was 69.1 years (range 24 to 98) and 1848 (55.3%) were performed in women, with a mean follow-up of 115 months (18 to 201). There were 883 MoM and 2458 CoP bearings. Crude incidence rates (cases/1000 person-years) were: infection 1.3 vs 0.8; dislocation 3.3 vs 3.1 and all-cause revision 4.3 vs 2.2, respectively. There was a significantly higher revision rate after ten years (adjusted hazard ratio 9.4; 95% CI 2.6 to 33.6) in the MoM group, and ten of 26 patients presented with an adverse local tissue reaction at revision. No differences in mortality, osteolysis or clinical outcome were seen. In conclusion, we found similar results for small-head MoM and CoP bearings up to ten years post-operatively, but after ten years MoM THRs had a higher risk of all-cause revision. Furthermore, the presence of an adverse response to metal debris seen in the small-head MOM group at revision is a cause for concern.

Is there any benefit in pre-operative urinary analysis before elective total joint replacement?

Whether patients with asymptomatic bacteriuria should be investigated and treated before elective hip and knee replacement is controversial, although it is a widespread practice. We conducted a prospective observational cohort study with urine analyses before surgery and three days post-operatively. Patients with symptomatic urinary infections or an indwelling catheter were excluded. Post-discharge surveillance included questionnaires to patients and general practitioners at three months. Among 510 patients (309 women and 201 men), with a median age of 69 years (16 to 97) undergoing lower limb joint replacements (290 hips and 220 knees), 182 (36%) had pre-operative asymptomatic bacteriuria, mostly due to Escherichia coli, and 181 (35%) had white cells in the urine. Most patients (95%) received a single intravenous peri-operative dose (1.5 g) of cefuroxime as prophylaxis. On the third post-operative day urinary analysis identified white cells in 99 samples (19%) and bacteriuria in 208 (41%). Pathogens in the cultures on the third post-operative day were different from those in the pre-operative samples in 260 patients (51%). Only 25 patients (5%) developed a symptomatic urinary infection during their stay or in a subsequent three-month follow-up period, and two thirds of organisms identified were unrelated to those found during the admission. All symptomatic infections were successfully treated with oral antibiotics with no perceived effect on the joint replacement. We conclude that testing and treating asymptomatic urinary tract colonisation before joint replacement is unnecessary.

Associations between gait and clinical parameters in patients with severe knee osteoarthritis: a multiple correspondence analysis.

BACKGROUND: Given the complexity of the gait of patients with knee osteoarthritis, a multiple correspondence analysis may be helpful to optimise the extraction of relevant gait and clinical information. Therefore, the aims of this study are to identify the main associations with clinical and gait biomechanical parameters and to evaluate whether there are more specific knee osteoarthritis groups with different gait profiles. METHODS: Ninety patients with severe knee osteoarthritis and twenty-six healthy individuals participated in this study. Pain and function were assessed with the WOMAC Index; knee joint deformity was assessed by the hip-knee-ankle angle on full-limb radiography; and full body gait analysis was performed with a motion analysis system and force plates. FINDINGS: Using multiple correspondence analysis, two categories of gait parameters that best explain the gait variance of patients with knee osteoarthritis were highlighted. The forward displacement category is composed of the parameters speed, stride length, hip flexion and knee flexion. The frontal category is composed of the parameters thorax obliquity and knee adductor moments. Moreover, based on these parameters, four distinct gait profiles were identified: two gait profiles were associated with knee varus deformities, increased thorax obliquity and different forward displacements, while two gait profiles were associated with valgus deformities and different forward displacements. INTERPRETATION: These gait parameters can be used to simplify the characterisation of the gait of the knee osteoarthritis population. Patients in varus profiles increase thorax obliquity on the stance limb and may reduce forward displacement. Patients in valgus profiles, however, only reduce forward displacement.

Comparison of the outcome following the fixation of osteotomies or fractures associated with total hip replacement using cables or wires: the results at five years.

There are no recent studies comparing cable with wire for the fixation of osteotomies or fractures in total hip replacement (THR). Our objective was to evaluate the five-year clinical and radiological outcomes and complication rates of the two techniques. We undertook a review including all primary and revision THRs performed in one hospital between 1996 and 2005 using cable or wire fixation. Clinical and radiological evaluation was performed five years post-operatively. Cables were used in 51 THRs and wires in 126, and of these, 36 THRs with cable (71%) and 101 with wire (80%) were evaluated at follow-up. The five-year radiographs available for 33 cable and 91 wire THRs revealed rates of breakage of fixation of 12 of 33 (36%) and 42 of 91 (46%), respectively. With cable there was a significantly higher risk of metal debris (68% vs. 9%; adjusted relative risk (RR) 6.6; 95% confidence interval (CI) 3.0 to 14.1), nonunion (36% vs. 21%; adjusted RR 2.0; 95% CI 1.0 to 3.9) and osteolysis around the material, acetabulum or femur (61% vs 19%; adjusted RR 3.9; 95% CI 2.3 to 6.5). Cable breakage increased the risk of osteolysis to 83%. There was a trend towards foreign-body reaction and increased infection with cables. Clinical results did not differ between the groups. In conclusion, we found a higher incidence of complications and a trend towards increased infection and foreign-body reaction with the use of cables.

Meticillin resistance in orthopaedic coagulase-negative staphylococcal infections.

Orthopaedic infections due to coagulase-negative staphylococci (CoNS) and meticillin-resistant strains may be increasing. We assessed secular trends of CoNS infections and factors associated with meticillin resistance by performing a 13-year retrospective cohort study of orthopaedic patients with CoNS infections from January 1995 to December 2007. Of 60 CoNS infections, 57 (95%) were implant-related. Median follow-up after end of treatment was 5.1 years (range: 2.4-13.8). During the study period, 44,237 orthopaedic procedures were performed, 21,299 (48%) with implants. The overall cumulative incidence of CoNS-associated infection was 0.14% and 0.28% for implant-related procedures. There were non-significant changes in the absolute number or cumulative incidence of CoNS infection (chi-squared test, P values for trend: 0.45 and 0.97, respectively). Forty-five episodes (75%) were due to meticillin-resistant strains. The proportion of meticillin resistance remained stable over time (P for trend: 0.65). Whereas few (4/15) meticillin-susceptible strains were associated with prior prophylaxis that covered the causative pathogen, 28/45 meticillin-resistant strains were associated with inadequate prophylaxis (P=0.03). The cumulative incidence of orthopaedic CoNS infection is low and stable in our institution and almost exclusively implant-related. The proportion of meticillin resistance among CoNS has remained stable over the last decade with a favourable clinical outcome.

Influence of surgical approach on functional outcome in reverse shoulder arthroplasty.

INTRODUCTION: Reverse shoulder arthroplasties (RSA) can be performed using a Deltopectoral (DP) or alternatively a Transdeltoid (TD) approach. HYPOTHESIS: Although the humeral cut is lower by TD approach, this should not affect postoperative functional results. MATERIAL AND METHODS: This retrospective multicentric study evaluated the complete medical records of RSA implanted between October 2003 and December 2008. Inclusion criteria were: follow-up of at least 1 year, a complete file including a comparative radiological work-up making it possible to analyze eventual arm and humeral lengthening. Evaluation of postoperative function was based on Active Anterior Elevation (AAE). RESULTS: We studied 144 RSA in 142 patients. One hundred and nine RSA were implanted by the DP approach and 35 by the TD approach. Mean lengthening of the humerus compared to the controlateral side by DP approach was 0.5±1.3 cm while there was a mean shortening of -0.5±1.0 cm by TD approach (P<0.001). The difference in cut was partially compensated by using thicker polyethylene inserts with the TD approach. Mean arm lengthening compared to the controlateral side was 1.7±1.7 cm by DP approach and 1.2±1.4 cm by TD approach (mean difference 0.5 cm; (95% CI -0.1; 1.2). AAE for RSA by DP approach was 145±22° and 135±29° by TD approach (mean difference 10°, 95% CI -1; 21). DISCUSSION: RSA results in improved AAE because of restored deltoid tension and an increase in the deltoid lever arm. The humeral cut by TD is lower, but this was partially corrected in this study by the use of thicker polyethylene inserts. Nevertheless there is no significant clinical difference in postoperative function between the two approaches.

Prevalence of neurologic lesions after total shoulder arthroplasty.

BACKGROUND: Clinically evident neurologic injury of the involved limb after total shoulder arthroplasty is not uncommon, but the subclinical prevalence is unknown. The purposes of this prospective study were to determine the subclinical prevalence of neurologic lesions after reverse shoulder arthroplasty and anatomic shoulder arthroplasty, and to evaluate the correlation of neurologic injury to postoperative lengthening of the arm. METHODS: All patients undergoing either a reverse or an anatomic shoulder arthroplasty were included during the period studied. This study focused on the clinical, radiographic, and preoperative and postoperative electromyographic evaluation, with measurement of arm lengthening in patients who had reverse shoulder arthroplasty according to a previously validated protocol. RESULTS: Between November 2007 and February 2009, forty-one patients (forty-two shoulders) underwent reverse shoulder arthroplasty (nineteen shoulders) or anatomic primary shoulder arthroplasty (twenty-three shoulders). The two groups were similar with respect to sex distribution, preoperative neurologic lesions, and Constant score. Electromyography performed at a mean of 3.6 weeks postoperatively in the reverse shoulder arthroplasty group showed subclinical electromyographic changes in nine shoulders, involving mainly the axillary nerve; eight resolved in less than six months. In the anatomic shoulder arthroplasty group, a brachial plexus lesion was evident in one shoulder. The prevalence of acute postoperative nerve injury was significantly more frequent in the reverse shoulder arthroplasty group (p = 0.002), with a 10.9 times higher risk (95% confidence interval, 1.5 to 78.5). Mean lengthening (and standard deviation) of the arm after reverse shoulder arthroplasty was 2.7 ± 1.8 cm (range, 0 to 5.9 cm) compared with the normal, contralateral side. CONCLUSIONS: The occurrence of peripheral neurologic lesions following reverse shoulder arthroplasty is relatively common, but usually transient. Arm lengthening with a reverse shoulder arthroplasty may be responsible for these nerve injuries.

Influence of patient activity on femoral osteolysis at five and ten years following hybrid total hip replacement.

We conducted a longitudinal study including patients with the same type of primary hybrid total hip replacement and evaluated patient activity and femoral osteolysis at either five or ten years post-operatively. Activity was measured using the University of California, Los Angeles scale. The primary outcome was the radiological assessment of femoral osteolysis. Secondary outcomes were revision of the femoral component for aseptic loosening and the patients' quality of life. Of 503 hip replacements in 433 patients with a mean age of 67.7 years (30 to 91), 241 (48%) were seen at five and 262 (52%) at ten years post-operatively. Osteolytic lesions were identified in nine of 166 total hip replacements (5.4%) in patients with low activity, 21 of 279 (7.5%) with moderate activity, and 14 of 58 (24.1%) patients with high activity. The risk of osteolysis increased with participation in a greater number of sporting activities. In multivariate logistic regression adjusting for age, gender, body mass index and the inclination angle of the acetabular component, the adjusted odds ratio for osteolysis comparing high vs moderate activity was 3.6 (95% confidence interval 1.6 to 8.3). Stratification for the cementing technique revealed that lower quality cementing increased the effect of high activity on osteolysis. Revision for aseptic loosening was most frequent with high activity. Patients with the highest activity had the best outcome and highest satisfaction. In conclusion, of patients engaged in high activity, 24% had developed femoral osteolysis five to ten years post-operatively.

Assessment of patients' tendency to give a positive or negative rating to healthcare.

BACKGROUND: Adjustment of patient satisfaction scores for case-mix variables such as age and sex may lead to overadjustment. The patient's tendency to rate healthcare positively or negatively may be the only variable that should be adjusted to improve the comparability of satisfaction scores between healthcare providers. OBJECTIVE: To develop a measure of "rating tendency", assess its stability over time, explore its distribution across subgroups of patients and its association with patient opinion scores. DESIGN AND SUBJECTS: A scale based on 10 hypothetical scenarios describing hospital care episodes was developed. It was administered both before and after hospitalisation to 203 patients programmed for elective orthopaedic surgery in a Swiss teaching hospital. A problem score regarding the actual hospitalisation was obtained at follow-up. RESULTS: The rating tendency scale had good internal consistency (Cronbach alpha 0.85), and factor analysis confirmed that it measured a single underlying concept. However, the correlation between prehospitalisation and posthospitalisation measures was moderate (intraclass correlation coefficient 0.55, p<0.001), as was the correlation with the hospitalisation problem score (Spearman r = -0.22, p = 0.002). The pattern of rating tendency across subgroups of respondents mirrored the pattern of problem scores. Adjusting for the rating tendency had little effect on comparisons of problem scores between subgroups of patients, all of whom were treated at the same hospital. CONCLUSIONS: A patient's "rating tendency" can be measured using a reliable 10-item scale. The utility of adjusting satisfaction scores for rating tendency when comparing hospitals remains to be tested.

[Dislocation of a total hip prosthesis: etiology and treatment]. / Luxation d'une arthroplastie totale de la hanche: étiologie et prise en charge.

Dislocation of a total hip prosthesis is a substantial burden in terms of morbidity and health care costs. The incidence of dislocation is highest during the first postoperative months but the risk persists throughout the entire life of the patient. The first dislocation is treated by an emergency closed reduction of the hip undergeneral anaesthesia, following which about three out of four patients will have a stable hip. In cases of recurrent dislocation the treatment is difficult, depending upon the time between surgery and dislocation, the identification of an etiologic factor, and the general status of the patient. Patients in which a specific cause can be identified have better results after surgical revision. When no causal factor is detected several surgical options are possible, but the results are less consistent.

Fixed-bearing versus mobile-bearing total knee arthroplasty: a prospective randomised, clinical and radiological study with mid-term results at 7 years.

Mobile-bearing (MB) total knee arthroplasty (TKA) was developed as an alternative to the established fixed-bearing (FB) design because of theoretical advantages. Short-term studies comparing these designs have not shown any differences in clinical and radiographic results. We compared the results at 7 years of a randomised study of patients undergoing TKA using either a FB or a MB variant of the same prosthesis. Fifty-two patients (52 knees) with an average age of 70 years received a FB posterior-stabilized prosthesis, and 50 patients (52 knees) with an average age of 72 years, a MB prosthesis. All implants were cemented and the patella was routinely resurfaced. Preoperatively, there were no differences between the two groups, and surgical procedure and postoperative protocol were the same for both. At an average follow-up of 7.1 years, no significant differences of FB over MB design could be demonstrated with respect to the American Knee Society score (AKSS), pain score, a questionnaire of general health (SF-12 score), range of motion (ROM), or complication rates. Radiographs showed no significant difference in prosthetic alignment or evidence of loosening. Two knees with a MB design required reoperation, one for persistent joint stiffness and another to treat septic loosening. One patient with a MB prosthesis with signs of tibial component loosening was asymptomatic. We conclude that at mid-term follow-up there is no evidence to prove the superiority of MB over FB TKA with regard to the clinical and radiographic results.

[Cardiopulmonary risk factors in patients with sleep apnea]. / Kardiopulmonale Riskofaktoren bei Schlafapnoepatienten.

Since the interaction between disorders of the respiratory coordination and cardiovascular or cardiopulmonary regulation is still largely unknown the intention of the present investigation is to point out the coincidence of cardiac arrhythmias, such as premature ventricular capture (PVC) beats and conduction blocks, with obstructive sleep apnea (OSA). For the first time a group of more than 300 patients with suspected OSA is examined concerning risk factors and frequent diagnoses as obesity, hypertension, coronary heart disease (CHD), heart insufficiency, chronic obstructive pulmonary disease (COPD), and daytime hypoxaemia. Summarizing the results of lung function test, blood gas analysis, strain-ECG, Holter-ECG and inductive plethysmography with oxygen partial pressure measurement by ambulatory work-up the following statements can be made: PVC beats occurring markedly during sleep give hints for OSA being the underlying cause, especially if the patients are young and overweight. Hypoxaemia increasing during the apnea episodes should be considered as one possible pathogenetic mechanism. Second- and third degree conduction blocks and sinus arrest coincident very often with OSA. They suggest to be life-limiting factors the more so since they often go along with CHD or heart insufficiency. Systemic arterial hypertension and overweight have the highest prevalence in OSA, signs for heart insufficiency and daytime hypoxaemia are also significantly more frequent than in non-OSA patients. We could find no hints for direct pathogenetic coherence between CHD and OSA or between COPD and OSA, nevertheless pronounced nocturnal changes in blood gases and intrathoracic hemodynamics have important influence on the cardiopulmonary and cardiovascular system, as partly illuminated in other more pathogenetic oriented studies by the present time.