André Stark

The foot: still the most important reason for walking incapacity in rheumatoid arthritis: Distribution of symptomatic joints in 1,000 RA patients

Background and purpose Our knowledge of frequency of foot involvement in rheumatoid arthritis (RA) is still often based on a study from Finland in 1956. Great changes in the treatment of RA may have led to a different situation. We investigated the distribution of joint involvement in RA patients today, with special attention given to the feet and subjective walking ability. Methods 1,000 RA patients answered a questionnaire concerning joints affected, joint surgery, foot problems, and subjectively experienced reasons for walking incapacity. Results In 45% of the patients, the forefoot was involved at the start of the disease. In 17%, the hindfoot/ankle was involved at the start. Only hand symptoms were commoner. 80% of patients reported current foot problems, 86% in the forefoot and 52% in the hindfoot/ankle. Difficulty in walking due to the feet was reported by 71%. For 41% of patients, the foot was the most important part of the lower extremity causing reduced walking capacity, and for 32% it was the only part. Interpretation After the hand, the foot was the most frequently symptomatic joint complex at the start of the disease, but also during active medical treatment. The foot caused walking disability in three-quarters of the cases and—4 times as often as the knee or the hip—it was the only joint to subjectively impair gait.

Healing complications after internal fixation of trochanteric hip fractures: the prognostic value of osteoporosis.

Summary: In a 3-year prospective randomized trial, the prognostic value of osteoporosis in terms of predicting healing complications due to implant failures or loss of fracture reduction has been studied in 113 patients with intertrochanteric hip fractures treated with either a sliding screwplate or Ender nailing. According to the Barnet and Nordins osteoporosis index, 66 patients were considered to have moderate or severe osteoporosis. There were no differences between patients with or without osteoporosis as regards the number of fractures with collapse in varus >10°, redislocation >10 mm, or compression exceeding 10 mm. Six months after surgery, 48 patients failed in healing or healed with complications. These cases disclosed increased osteoporosis in comparison with those showing noncomplicated healing. Patients with osteoporosis who had unstable fractures treated by Ender nailing were found to have the worst prognosis for healing complications (p=0.006). Of the 33 fractures with implant failures, 25 (76%) occurred in patients with osteoporosis (p=0.04). In patients with osteoporosis, the frequency of mechanical failures was significantly higher in fractures with the device positioned incorrectly. Independently of the device used, patients with unstable trochanteric hip fractures and osteoporotic bone were the group with the highest risk for failures of the implant.

Orthopaedic surgery of the lower limbs in 49,802 rheumatoid arthritis patients : results from the Swedish National Inpatient Registry during 1987 to 2001

Objectives: To analyse changes in the rates of hospital admission and use of orthopaedic surgery to the lower limbs in Swedish patients with rheumatoid arthritis between 1987 and 2001. Methods: Data for all rheumatoid patients admitted to hospital between 1987 and 2001 were abstracted from the Swedish National Hospital Discharge Register (SNHDR). The data in the register are collected prospectively, recording all inpatient admissions throughout Sweden. The SNHDR uses the codes for diagnoses at discharge and surgical procedures according to the Swedish version of the International Classification of Diseases (ICD). Results: In all, 49 802 individual patients with rheumatoid arthritis were identified, accounting for 159 888 inpatient visits. Hospital admissions for rheumatoid arthritis decreased by 42% (p<0.001) during the period 1987 to 2001. Twelve per cent of all admissions were for a rheumatoid arthritis related surgical procedure to the lower limbs; those admissions decreased markedly (by 16%) between 1987 and 1996, and by 12% between 1997 and 2001, as did the overall number of rheumatoid arthritis related surgical procedures to the lower limbs during both time periods. Between 1997 and 2001, 47% of all rheumatoid arthritis related surgical procedures were total joint arthroplasties. There was an overall trend towards reduced length of hospital stay after orthopaedic surgery to the lower limbs during the study period. Conclusions: Rates of hospital admission and rheumatoid arthritis related surgical procedures to the lower limbs in Swedish patients with rheumatoid arthritis decreased between 1987 and 2001. This may reflect trends in disease severity, management, and health outcomes of this disease in Sweden.

The risk of revision due to dislocation after total hip arthroplasty depends on surgical approach, femoral head size, sex, and primary diagnosis: An analysis of 78,098 operations in the Swedish Hip Arthroplasty Register

Background and purpose The effects of patient-related and technical factors on the risk of revision due to dislocation after primary total hip arthroplasty (THA) are only partly understood. We hypothesized that increasing the femoral head size can reduce this risk, that the lateral surgical approach is associated with a lower risk than the posterior and minimally invasive approaches, and that gender and diagnosis influence the risk of revision due to dislocation. Patients and methods Data on 78,098 THAs in 61,743 patients performed between 2005 and 2010 were extracted from the Swedish Hip Arthroplasty Register. Inclusion criteria were a head size of 22, 28, 32, or 36 mm, or the use of a dual-mobility cup. The covariates age, sex, primary diagnosis, type of surgical approach, and head size were entered into Cox proportional hazards models in order to calculate the adjusted relative risk (RR) of revision due to dislocation, with 95% confidence intervals (CI). Results After a mean follow-up of 2.7 (0–6) years, 399 hips (0.5%) had been revised due to dislocation. The use of 22-mm femoral heads resulted in a higher risk of revision than the use of 28-mm heads (RR = 2.0, CI: 1.2–3.3). Only 1 of 287 dual-mobility cups had been revised due to dislocation. Compared with the direct lateral approach, minimally invasive approaches were associated with a higher risk of revision due to dislocation (RR = 4.2, CI: 2.3–7.7), as were posterior approaches (RR = 1.3, CI: 1.1–1.7). An increased risk of revision due to dislocation was found for the diagnoses femoral neck fracture (RR = 3.9, CI: 3.1–5.0) and osteonecrosis of the femoral head (RR = 3.7, CI: 2.5–5.5), whereas women were at lower risk than men (RR = 0.8, CI: 0.7–1.0). Restriction of the analysis to the first 6 months after the index procedure gave similar risk estimates. Interpretation Patients with femoral neck fracture or osteonecrosis of the femoral head are at higher risk of dislocation. Use of the minimally invasive and posterior approaches also increases this risk, and we raise the question of whether patients belonging to risk groups should be operated using lateral approaches. The use of femoral head diameters above 28 mm or of dual-mobility cups reduced this risk in a clinically relevant manner, but this observation was not statistically significant.

Decrease of RA-related orthopaedic surgery of the upper limbs between 1998 and 2004: data from 54 579 Swedish RA inpatients

OBJECTIVES To describe the overall use and temporal trends in orthopaedic upper limb surgery associated with RA on a nation wide basis in Sweden between 1998 and 2004. METHODS Data for all inpatient visits during 1998-2004 for patients older than 18 yrs with RA-related diagnoses were extracted from the Swedish National Hospital Discharge Registry (SNHDR). The SNHDR prospectively collects data on all hospital admissions in Sweden according to the International Classification of Diseases (ICD). Data were analysed with respect to orthopaedic surgery of the hand, elbow and shoulder. RESULTS During the study period, 54,579 individual RA patients were admitted to a Swedish hospital and 9% of these underwent RA-related surgery of the upper limbs. The RA patient cohort underwent a total of 8251 RA-related upper limb surgical procedures. The hand (77%) was most frequently operated on, followed by the shoulder (13%) and the elbow (10%). There was a statistically significant decrease of 31% for all admissions associated with RA-related upper limb surgery during 1998-2004 (P = 0.001). Some 10% of all RA-related upper limb surgery was due to total joint arthroplasties (TJAs), mostly for the elbow (59%). During 1998-2004, all TJAs, elbow-TJAs and shoulder-TJAs had a stable occurrence. In contrast, the overall numbers of hand-TJAs significantly increased (P = 0.009). CONCLUSIONS Rates of RA-related upper limb surgery decreased and TJAs had a stable occurrence in Sweden during 1998-2004. The findings of this study may reflect trends in disease management and health outcomes of RA patients in Sweden.

Dual-mobility cups for revision due to instability are associated with a low rate of re-revisions due to dislocation 228 patients from the Swedish Hip Arthroplasty Register

Background and purpose Revision total hip arthroplasty (THA) due to recurrent dislocations is associated with a high risk of persistent instability. We hypothesized that the use of dual-mobility cups would reduce the risk of re-revision due to dislocation after revision THA. Patients and methods 228 THA cup revisions (in 228 patients) performed due to recurrent dislocations and employing a specific dual-mobility cup (Avantage) were identified in the Swedish Hip Arthroplasty Register. Kaplan-Meier survival analysis was performed with re-revision due to dislocation as the primary endpoint and re-revision for any reason as the secondary endpoint. Cox regression models were fitted in order to calculate the influence of various covariates on the risk of re-revision. Results 58 patients (25%) had been revised at least once prior to the index cup revision. The surgical approach at the index cup revision was lateral in 99 cases (44%) and posterior in 124 cases (56%). Median follow-up was 2 (0–6) years after the index cup revision, and by then 18 patients (8%) had been re-revised for any reason. Of these, 4 patients (2%) had been re-revised due to dislocation. Survival after 2 years with the endpoint revision of any component due to dislocation was 99% (95% CI: 97–100), and it was 93% (CI: 90–97) with the endpoint revision of any component for any reason. Risk factors for subsequent re-revision for any reason were age between 50–59 years at the time of the index cup revision (risk ratio (RR) = 5 when compared with age > 75, CI: 1–23) and previous revision surgery to the relevant joint (RR = 1.7 per previous revision, CI: 1–3). Interpretation The risk of re-revision due to dislocation after insertion of dual-mobility cups during revision THA performed for recurrent dislocations appears to be low in the short term. Since most dislocations occur early after revision THA, we believe that this device adequately addresses the problem of recurrent instability. Younger age and prior hip revision surgery are risk factors for further revision surgery. However, problems such as potentially increased liner wear and subsequent aseptic loosening may be associated with the use of such devices in the long term.

Minimum 5-Year Follow-Up of a Cementless, Modular, Tapered Stem in Hip Revision Arthroplasty

Hip revision surgery with a cementless tapered femoral component can provide axial and rotational stability in patients with compromised proximal bone stock. This study includes 90 cases revised with the Link MP (Waldemar Link, Hamburg, Germany) prosthesis. The median age at surgery was 72 (38-89) years. Aseptic loosening (70%) and periprosthetic fracture (22%) were common indications for surgery. Sixty-three patients (70%) were followed clinically with a median of 6 (5-11) years of follow-up. All other patients were followed through the Swedish Hip Register. The 5-year survival rate was 98% with stem removal and 90% with any reoperation as the end point. Complications included hip dislocation in 17 (19%) patients. The median Harris hip score was 78 (16-100) points, and the median radiographic stem migration was 2.7 mm at follow-up.

Total hip replacement versus open reduction and internal fixation of displaced femoral neck fractures: a randomized long-term follow-up study.

BACKGROUND Clinical trials with short and intermediate-term follow-up have demonstrated superior results for total hip replacement as compared with internal fixation with regard to hip function and the need for secondary surgery in elderly patients with a displaced intracapsular femoral neck fracture. The aim of the present study was to compare the results of total hip replacement with those of internal fixation over a long-term follow-up period of seventeen years. METHODS We enrolled 100 patients who had sustained a femoral neck fracture in a single-center, randomized controlled trial;all patients had had a healthy hip before the injury. The study group included seventy-nine women and twenty-one men with a mean age of seventy-eight years (range, sixty-five to ninety years). The subjects were randomly assigned to either total hip replacement (the arthroplasty group) (n = 43) or internal fixation (the control group) (n = 57). The primary end point was hip function, evaluated with use of the Harris hip score. Secondary end points included mortality, reoperations, gait speed, and activities of daily life. Follow-up evaluations were performed at three months and at one, two, four, eleven, and seventeen years. RESULTS The Harris hip score was higher in the total hip arthroplasty group, with a mean difference of 14.7 points (95%confidence interval, 9.2 to 20.1 points; p < 0.001 [analysis of covariance]) during the study period. We found no difference in mortality between the two groups. Four patients (9%) in the total hip replacement group and twenty-two patients (39%) in the internal fixation group had undergone a major reoperation (relative risk, 0.24; 95% confidence interval, 0.09 to 0.64).The overall reoperation rate was 23% (ten of forty-three) in the total hip replacement group and 53% (thirty of fifty-seven) in the internal fixation group (relative risk, 0.44; 95% confidence interval, 0.24 to 0.80). The results related to gait speed and activities of daily living favored the arthroplasty group during the first year. CONCLUSIONS Over a period of seventeen years in a group of healthy, elderly patients with a displaced femoral neck fracture, total hip replacement provided better hip function and significantly fewer reoperations compared with internal fixation without increasing mortality. LEVEL OF EVIDENCE Therapeutic Level I.

Gait pattern in rheumatoid arthritis

The purpose of this study was to analyse kinematic and kinetic gait changes in rheumatoid arthritis (RA) patients in comparison to healthy controls and to examine whether levels of functional disability (Health Assessment Questionnaire (HAQ)-scores) were associated with gait parameters. Using a three-dimensional motion analysis system, kinematic and kinetic gait parameters were measured in 50 RA patients and 37 healthy controls. There was a significant reduction in joint motions, joint moments and work in the RA cohort compared with healthy controls. The following joint motions were decreased: hip flexion-extension range (Delta6 degrees ), hip abduction (Delta4 degrees ), knee flexion-extension range (Delta8 degrees ) and ankle plantarflexion (Delta10 degrees ). The following joint moments were reduced: hip extensor (Delta0.30Nm/kg) and flexor (Delta0.20Nm/kg), knee extensor (Delta0.11Nm/kg) and flexor (Delta0.13Nm/kg), and ankle plantarflexor (Delta0.44Nm/kg). Work was lower in hip positive work (Delta0.07J/kg), knee negative work (Delta0.08J/kg) and ankle positive work (Delta0.15J/kg). Correlations were fair although significant between HAQ and hip flexion-extension range, hip abduction, knee flexion-extension range, hip abductor moment, stride length, step length and single support (r=-0.30 to -0.38, p<0.05). Our findings suggest that RA patients have overall less joint movement and specifically restricted joint moments and work across the large joints of the lower limbs during walking than healthy controls. There were only fair associations between levels of functional disability and gait parameters. The findings of this study help to improve the understanding how RA affects gait changes in the lower limbs.

Variation in the position and orientation of the elbow flexion axis

We analysed the axis of movement in the normal elbow during flexion in vivo using radiostereometric analysis (RSA). The results show an intraindividual variation in the inclination of the axis ranging from 2.1 degrees to 14.3 degrees in the frontal and from 1.6 degrees to 9.8 degrees in the horizontal plane analysed at 30 degrees increments. The inclination of the mean axis of rotation varied within a range of 12.7 degrees in the frontal and 4.6 degrees in the horizontal plane. In both planes, the mean axes were located close to a line joining the centres of the trochlea and capitellum. The intra- and interindividual variations of the axes of flexion of the elbow were greater than previously reported. These factors should be considered in the development of elbow prostheses.