Surgical outcomes of hip and knee arthroplasties for primary osteoarthritis in patients with Alzheimer's disease: a nationwide registry-based case-controlled study.

We compared the length of hospitalisation, rate of infection, dislocation of the hip and revision, and mortality following primary hip and knee arthroplasty for osteoarthritis in patients with Alzheimer's disease (n = 1064) and a matched control group (n = 3192). The data were collected from nationwide Finnish health registers. Patients with Alzheimer's disease had a longer peri-operative hospitalisation (median 13 days vs eight days, p < 0.001) and an increased risk for hip revision with a hazard ratio (HR) of 1.76 (95% confidence interval (CI) 1.03 to 3.00). Dislocation was the leading indication for revision. There was no difference in the rates of infection, dislocation of the hip, knee revision and short-term mortality. In long-term follow-up, patients with Alzheimer's disease had a higher mortality (HR 1.43; 95% CI 1.22 to 1.70), and only one third survived ten years post-operatively. Increased age and comorbidity were associated with longer peri-operative hospitalisation in patients with Alzheimer's disease.

Surgical outcomes of primary hip and knee replacements in patients with Parkinson's disease: a nationwide registry-based case-controlled study.

We evaluated the duration of hospitalisation, occurrence of infections, hip dislocations, revisions, and mortality following primary hip and knee replacement in 857 patients with Parkinson's disease and compared them with 2571 matched control patients. The data were collected from comprehensive nationwide Finnish health registers. The mean follow-up was six years (1 to 13). The patients with Parkinson's disease had a longer mean length of stay (21 days [1 to 365] vs 13 [1 to 365] days) and an increased risk for hip dislocation during the first post-operative year (hazard ratio (HR) 2.33, 95% confidence intervals (CI) 1.02 to 5.32). There was no difference in infection and revision rates, and one-year mortality. In longer follow-up, patients with Parkinson's disease had higher mortality (HR 1.94, 95% CI 1.68 to 2.25) and only 274 (34.7%) were surviving ten years after surgery. In patients with Parkinson's disease, cardiovascular and psychiatric comorbidity were associated with prolonged hospitalisation and cardiovascular diseases also with increased mortality.

Bioreconstructive poly-L/D-lactide implant compared with Swanson prosthesis in metacarpophalangeal joint arthroplasty in rheumatoid patients: a randomized clinical trial.

It was hypothesized that the bioresorbable interposition implant might offer a viable alternative to conventional silicone implant arthroplasty in rheumatoid metacarpophalangeal joint destruction. A randomized clinical study was performed to compare a stemless poly-L/D-lactide copolymer 96 : 4 (PLDLA) implant with the Swanson silicone implant. Results in 52 patients (53 hands and 175 joints) at a mean follow-up of 2 years (minimum 1 year) showed that the improvement in clinical assessments was comparable in both groups, except for better maintenance of palmar alignment in the Swanson group. The lack of implant fractures and intramedullary osteolysis were advantages of the PLDLA implant. The bioresorbable PLDLA interposition implant may offer an alternative tool for tailored reconstruction of rheumatoid metacarpophalangeal joints.

A midterm follow-up study of bioreconstructive polylactide scaffold implants in metacarpophalangeal joint arthroplasty in rheumatoid arthritis patients.

This paper presents the results of a prospective study of 80 metacarpophalangeal joint arthroplasties, in which biodegradable polylactide 96/4 copolymer scaffolds were used. Twenty-three rheumatoid arthritis patients were assessed at an average of 59 months after operation, which exceeds the resorption time of P(L/D)LA 96/4 according to animal experiments. Palmar subluxation exceeded half of the bone thickness in 39 joints before operation and in nine at the last follow-up. Ulnar deviation decreased from 25 degrees to 5 degrees , extension deficit from 32 degrees to 15 degrees and active flexion from 76 degrees to 63 degrees . The results are comparable with published data on silicone implant arthroplasties. Implant resorption did not induce any significant osteolysis in the medium term and the restoration of the structure and function of the hand was maintained after implant resorption, probably as the guided fibrous tissues had replaced the dissolved implant.

Radiocarpal arthrodesis in the treatment of the rheumatoid wrist. A prospective midterm follow-up.

This prospective study was performed to evaluate the clinical and radiological results of radiocarpal joint arthrodesis in the treatment of unstable Simmen group III and Larsen grade II or III rheumatoid wrists. Radiolunate arthrodesis was performed in 16 wrists and radioscapholunate arthrodesis in 7 wrists in 20 patients. When they were evaluated at a mean of 5.8 (range 3.5-9.8) years later, flexion was 29 degrees and extension 34 degrees , representing 67% and 92% of the preoperative values, respectively. Patient satisfaction was excellent, or good, for 20 wrists and satisfactory for 1 wrist. In two patients with poor satisfaction, arthritis progressed to the midcarpal joint and necessitated total arthrodesis of the wrist. Radiolunate joint arthrodesis, with inclusion of the scaphoid in the fusion if necessary, is a useful operation in the treatment of this degree of wrist disease as it produces a functional and pain-free wrist at the same time as preserving much of the mobility and bone stock.

A comparison of survival of moulded monoblock and modular tibial components of 751 AGC total knee replacements in the treatment of rheumatoid arthritis.

We evaluated the survival of moulded monoblock and modular tibial components of the AGC total knee replacement in patients with rheumatoid arthritis. Between 1985 and 1995, 751 knees with this diagnosis were replaced at our institution. A total of 256 tibial components were of the moulded design and 495 of the modular design. The mean follow-up of the moulded subgroup was 9.6 years (0.5 to 14.7), and that of the modular group 7.0 years (0.1 to 14.7). The groups differed significantly from each other in Larsen grade, cementing of components and patellar resurfacing, but no statistically significant difference between the survival of the components was found (Log rank test, p = 0.91). The cumulative success rate of the moulded group was 96.8% (95% confidence interval 93.6% to 98.4%) at five years and 94.4% (95% confidence interval 90.4% to 96.7%) at ten years, and of the modular group 96.2% (95% confidence interval 94% to 97.6%) and 93.6% (95% confidence interval 89.7% to 96%), respectively. Revision was required in 37 total knee replacements, the main causes were infection, pain, loosening of the tibial component and patellar problems. Survival rates for both components were satisfactory.

Spacer prostheses in two-stage revision of infected knee arthroplasty.

At present, no consensus exists on the best spacer alternative for the management of two-stage exchange arthroplasty of infected knee arthroplasties. In this retrospective study, patient records of 24 patients, who had undergone two-stage revisions in which resterilised prosthetic components were used as spacers, were reviewed. The outcome was compared to that of operations performed during the same period (1993-2003) using cement spacers (n=10). With an average follow-up of 32 months, control of infection was achieved in 26 cases (76%), with good or excellent clinical outcome in 19 cases (56%). Treatment failed and resulted in amputation at the level of the thigh before reimplantation in one case. Three patients did not undergo reimplantation. In four cases (12%) infection relapsed. The reinfection rate did not differ between the two spacer groups. Patients treated with resterilised components had a superior range of motion during the period between the two stages. Operative time was shorter and there was less blood loss in the reimplantation arthroplasty when a prosthetic spacer was used. We consider resterilised prosthetic components a safe and effective alternative to cement spacers in the management of infected knee arthroplasties.

Revision total knee arthroplasty with the Total Condylar III system in inflammatory arthritis.

We report a consecutive series of 16 revision total knee arthroplasties using the Total Condylar III system in 14 patients with inflammatory arthritis which were performed between 1994 and 2000. There were 11 women and three men with a mean age of 59 years (36 to 78). The patients were followed up for 74 months (44 to 122). The mean pre-operative Knee Society score of 37 points (0 to 77) improved to 88 (61 to 100) at follow-up (t-test, p < 0.001) indicating very good overall results. The mean range of flexion improved from 62 degrees (0 degrees to 120 degrees) to 98 degrees (0 degrees to 145 degrees) (t-test, p < 0.05) allowing the patients to stand from a sitting position. The mean Knee Society pain score improved from 22 (10 to 45) to 44 (20 to 50) (t-test, p < 0.05). No knee had definite loosening, although five showed asymptomatic radiolucent lines. Complications were seen in three cases, comprising patellar pain, patellar fracture and infection. These results suggest that the Total Condylar III system can be used successfully in revision total knee arthroplasty in inflammatory arthritis.

Patellar resurfacing reduces pain after TKA for juvenile rheumatoid arthritis.

Influence of patellar resurfacing after knee replacement and the frequency of patella infera and its relation to the postoperative appearance of the knee pain were assessed in patients with juvenile rheumatoid arthritis. Seventy-seven total knee arthroplasties using the AGC prosthesis with nonconstrained components were done on 52 patients with a mean followup of 7.3 years (range, 3-13 years). Anterior knee pain was present in 14 of 30 patients (47%) with an unreplaced patella and in two of 18 patients (11%) with patella resurfacing. The patella was replaced in 18 patients (35%) and in 23 of 77 knees (30%). Neither revision surgery of implanted patellar components nor any later resurfacing of an unreplaced patella were done during the followup. Preoperatively using the Insall-Salvati ratio, the majority of knees (54 of 77) had a low-riding patella. Patella infera occurred commonly in patients with juvenile rheumatoid arthritis. No connection between patella infera and anterior knee pain was found.

Previous synovectomy or epiphyseal stapling and the influence on knee replacement in juvenile chronic arthritis.

Seventy-seven anatomically graduated components (AGC) total knee arthroplasties (TKA) were performed on 52 patients with juvenile chronic arthritis. According to the nature of previous surgery on the knee, the patients were subdivided into three groups. The mean age at onset of disease in 23 patients with previous synovectomy of the knee was 11 (1.5-16) years, the mean age at the time of synovectomy was 20 (4-42) and the mean age when arthroplasty was performed was 31 (18-45) years. In nine patients with previous epiphyseal stapling, the mean age at disease onset was 4 (1.5-8) years, at stapling 8 (4-16) years, and at arthroplasty 23 (18-30) years. In patients with no previous surgery, the mean age at disease onset in this group was 7 (1.5-16) years and the mean age at arthroplasty 34 (16-64) years. Patients with need for epiphyseal arrest had an early disease onset and knee replacement in early adulthood. The mean age at knee replacements was highest in the group with no prior surgery.

Bioreconstructive joint scaffold implant arthroplasty in metacarpophalangeal joints: short-term results of a new treatment concept in rheumatoid arthritis patients.

Swanson silicone implant is the "gold standard" of metacarpophalangeal joint reconstruction in rheumatoid arthritis (RA) patients. However, durability problems of silicone implants have led us to develop a new technique based on bioreconstructive implants. PLA96 (poly-L,D-lactide copolymer, L:D ratio of 96:4) scaffolds were engineered. Bioabsorption and substitution of porous PLA96 scaffold with living tissue eventually produce a neojoint. In the current prospective study, 23 RA patients (80 joints) were operated on, using PLA96 implants. Fifteen patients (54 joints) have been monitored for at least 1 year. Pain alleviation was well achieved. Range of motion improvement was emphasized to extension direction of functional arc. The average ulnar deviation was preoperatively 26 degrees, and at follow-up it was 6 degrees. Volar subluxation was noticeable in 56% of joints preoperatively and in 6% at 1-year follow-up. This is the first report of the formation of a living, functional joint in situ by means of a synthetic bioreconstructive joint scaffold. Results of this preliminary short-term study are comparable with previously published data on silicone arthroplasty. However, bioreconstructive prostheses can aid in preventing problems that occur with biostable prostheses. Tissue engineering has created a new era in the reconstruction of damaged joints.

Increased volumetric wear of polyethylene liners with more than 3 years of shelf-life time.

We analyzed 20 retrieved gamma-sterilized polyethylene liners (Biomet Hexloc). The long-term durability varied significantly depending on shelf-life time before implantation. Liners with a shelf-life time of 3 years or more evinced significantly ( P 0.002) higher volumetric wear than those with a shelf life time less than 3 years. Infrared spectroscopy and scanning calorimetry showed that all explanted implants underwent substantial in vivo oxidation and crystallization. The oxidative ageing of polyethylene renders the polyethylene liner susceptible to severe wear. Scanning electron microscopy of the bearing surface of the liner revealed abrasive wear as a dominant mechanism. Moreover, poor acetabular design produces excessively thin liners, substandard locking mechanism, and backside wear of the liner. The primary reason for severe wear in the Hexloc liner was poor modular design and oxidative degradation of the polyethylene.

Dual Articular Knee in demanding primary and revision replacements in patients with rheumatic diseases.

We report the results of 25 total knee replacements in 24 patients with rheumatoid arthritis (RA) using the Dual Articular Knee prosthesis. There were four primary and 21 revision procedures. The main indication was severe joint instability. In four infected arthroplasties a two-stage revision procedure was used. Four patellar tendon avulsions and one deep infection were encountered. Results were excellent in 18 patients. Dual Articular Knee proved to be favourable in both demanding primary as well as revision arthroplasties in patients with RA.

Insufficiency fractures in patients with chronic inflammatory joint diseases.

OBJECTIVE: To describe the typical sites of stress fractures in the lower extremities and pelvis in rheumatoid patients (rheumatoid arthritis, juvenile chronic arthritis, psoriatic arthritis, ankylosing spondylitis). METHODS: Thirty-three patients with 52 stress fractures [mean age 44 years (range 11-73)] were studied at the authors' institution when they were being treated for their rheumatic diseases. Fourteen patients had RA, 9 JCA, 5 PsoA, and 5 SPA. Stress fractures were detected from patient documents and from series radiographs in suspected cases. In some cases magnetic resonance imaging was also performed. RESULTS: One patient presented with 5 fractures, 2 patients with 4 and 3 fractures, and 7 patients with 2 fractures each. Other patients (n = 19) had only one fracture each. The metatarsal (MT) bones were the most common site of involvement. Twenty-five of the 52 fractures were located on MT I-V. The second and third most common sites were thefibula (n = 13) and tibia (n = 6). All fractures of the lower tibia or fibula were associated with valgus malalignment of the ankle. CONCLUSION: If a patient with rheumatic disease experiences sudden and unexplained pain localised in the forefoot, above the ankle, below the knee, or in the pelvis, a stress fracture should be suspected. Patients with severe osteoporosis, high-load corticosteroid or methotrexate therapy, or marked joint deformity are at high risk of developing stress fracture.

The Souter-Strathclyde elbow arthroplasty. A clinical and radiological study of 525 consecutive cases.

We present the results of 525 primary Souter elbow arthroplasties undertaken in 406 patients between 1982 and 1997. There were 372 women and 34 men with a mean age of 57 years; 119 patients had a bilateral procedure. The elbows were affected by chronic inflammatory disease, usually rheumatoid arthritis, which had been present for a mean of 24.7 years (2 to 70). In about 30% the joints were grossly destroyed with significant loss of bone. In 179 elbows the ulnar components were metal-backed and retentive; in the remaining 346, with better bone stock, non-retentive, all-polyethylene prostheses were used. Because of complications, 108 further operations were required in 82 patients. During the early years the incidence of complications was higher. Dislocation was the indication for 30 further procedures in 26 patients. Thirty patients underwent 33 revision procedures for aseptic loosening, 12 had 29 operations because of deep infection, two for superficial infection, and 14 further operations were done for other reasons. The cumulative rate of success, without aseptic loosening, five and ten years after surgery, was 96% and 85%, respectively.