Coxa valga and antetorta configuration leads to underestimation of the femoral component size: a matched case-control study of patients undergoing cementless total hip arthroplasty.

BACKGROUND: Total hip arthroplasty (THA) is the gold standard procedure for patients with end-stage osteoarthritis after failed conservative therapy. Digital templating is commonly employed in preoperative preparation for THA and contributes positively to its outcome. However, the impact of coxa valga and antetorta (CVA) configurations on stem size prediction accuracy remains not reported. Previous studies demonstrated that the size of the lesser trochanter (LT) can be used to determine femoral anteversion on pelvis radiographs. This study investigates the accuracy of preoperative digital templating in predicting stem size in patients with CVA undergoing cementless THA. METHODS: Preoperative radiographs of 620 patients undergoing cementless THA were retrospectively investigated. Radiographs were standardized with patients standing and the leg internally rotated by 15°. A CVA group was established including patients with a CCD angle greater than 140° and a lesser trochanter (LT) size of at least 10 mm for men and 8 mm for women. For the control group, radiographs with a CCD angle ranging from 125-135° and LT size 3-10 mm for men and 3-8 mm for women were selected. Preoperative templating was performed using mediCAD. To reduce confounding factors, case-control matching was carried out for BMI and body height. RESULTS: After case-control matching, a total of thirty-one matches were analyzed. Stem size was underestimated in 74% (23/31) in the CVA and 13% (4/31) in the control group (p < 0.001). Moreover, patients with CVA were more likely to be underestimated by two sizes compared to controls (p < 0.004). In contrast, the exact stem size was predicted more frequently in the control group (p < 0.001). CONCLUSION: Stem size in patients with a CVA configuration are at high risk of being underestimated when using digital templating. These findings can be valuable for guiding in intraoperative decisions and lowering the risk of complications associated with an undersized femoral component.

Morphological study of synovial changes in two-stage reconstructions of the infected hip and knee arthroplasties.

OBJECTIVES: To study the morphological changes of the regenerating synovium in two-stage revision arthroplasty, which is the gold standard for treatment of periprosthetic joint infection. DESIGN: The authors analysed a series of synovial biopsies to examine morphological changes in healing periprosthetic tissues damaged by previous surgery and infection. METHODS: Synovial tissues from 19 patients (10 knees and 9 hips) who underwent a two-stage exchange surgery for periprosthetic infection were reviewed and correlated with clinical and laboratory findings. SETTING: Retrospective morphological study. PARTICIPANTS: Archival tissues from 19 two-stage revision arthroplasties in adult patients. RESULTS: Healing synovial tissue obtained at the reimplantation surgery showed characteristic layering: superficial fibrin exudate, immature richly vascularised granulation tissue and deeper maturing granulation tissue and fibrosis. Although increased neutrophil counts were found in the majority of cases, 2 of 19 cases showed dense infiltrates indicative of persistent infection, which correlated with positive microbiology in one case. One of the cases failed due to acetabular loosening and two cases failed due to late superinfection. One case showed a dense infiltration of eosinophils suggestive of a hypersensitivity reaction, which was subsequently proven by cutaneous tests. Foci of extramedullary haematopoiesis were detected in two cases. CONCLUSIONS: We observed characteristic morphological changes in the healing synovial tissue during reimplantation surgery for periprosthetic infection in serologically and microbiologically sterile tissues. Substantial increased counts of synovial neutrophils (>200 cells/10 high-power fields) seem to be indicative of persistent infection of the joint; therefore, prolonged antibiotic therapy should be considered in positive cases.

Modulation of bovine chondrocyte metabolism by free periosteal grafts in vitro.

PURPOSE: Autologous chondrocyte transplantation (ACT) is an established method in cartilage repair. Although long-term results show durable repair of isolated cartilage defects, some problems still remain. Since hypertrophy of the transplanted periosteum is a common problem, alternatives for periosteum are in demand. Periosteal grafts have been reported to stimulate neochondrogenesis via paracrine effects. The objective of this study was to evaluate the modulation of chondrocyte metabolism by periosteal grafts in vitro. METHODS: Periosteal explants and articular chondrocytes obtained from slaughtered adult cattle were co-cultured in a newly established perfusion system. The experimental groups were: 1. monocultured chondrocytes; 2. chondrocytes cultured with synovial supernatants; 3. chondrocytes cultured with periosteal supernatants; 4. chondrocytes co-cultured with periosteal explants. RESULTS: Chondrocyte proliferation, evaluated by measuring total DNA content, was prolongated by periosteal and synovial explants. Immunocytochemical staining of collagen type II was stronger in monoculture than in co-culture. Protein biosynthetic activity estimated by [³H]-proline incorporation, as well as extracellular matrix deposition for collagen type II, were reduced by periosteal and synovial explants. Additionally, co-culturing led to a decrease in aggrecan synthesis and release. The inhibiting effects were significantly stronger when cellular chondrocyte-periosteal cross-talk was made possible via paracrine effects. CONCLUSIONS: The results of our study suggest a catabolic effect of periosteal explants on isolated chondrocytes in vitro. Further investigations are necessary whether periosteum in ACT is dispensable.

Amyloid deposition in rheumatoid arthritis of the hip.

The aim of this study was to examine the frequency of amyloid deposition in patients with end-stage rheumatoid arthritis (RA) of the hip. The impact on the clinical situation and the RA severity regarding the inflammation was analyzed. Fifty patients with RA who consecutively underwent total hip replacement were prospectively evaluated. X-rays of the patients were analyzed radiologically (Larsen score) to quantify the radiological changes. A clinical score (Harris Hip Score) was preoperatively calculated from every patient. A laboratory set of inflammation markers (erythrocyte sedimentation rate, CRP, serum amyloid A-SAA, electrophoresis) was measured in every patient the day before the operation. Specimens of bone and cartilage from the femoral head and of the capsule were obtained from every patient intraoperatively for histological evaluation. A histological grading was performed. In patients with amyloid deposits, the subtypes were characterized immunohistologically. Ninety-two percent of the patients had raised SAA in the blood samples, but the only amyloid subtype was ATTR. No correlation was found for any other measured item, such as inflammation signs in the blood samples, the histological grading, the radiological or the clinical score. Amyloid plays a role in inflammatory joint destruction processes in RA with raised SAA values, but the amyloid deposits in the joint are of a different subtype. Thus, these amyloid deposits can be considered as minor pathologic significance. A correlation to the radiological and histological changes was ruled out by our study. As in degenerative arthritis, ATTR amyloid deposits may be an incidental finding in aged joints.

The value of routine histopathology during hip arthroplasty in patients with degenerative and inflammatory arthritis.

The purpose of this study was to evaluate the effectiveness of routine pathological examination of operative specimens obtained during primary total hip arthroplasty (THA) performed for osteoarthritis (OA) and rheumatoid arthritis (RA). 100 consecutive patients (50 OA, 50 RA) were prospectively evaluated. A radiological score (Kellgren-Lawrence/Larsen) and a clinical score (Harris Hip Score) were calculated in each case. Specimens of bone and cartilage from the femoral head as well as capsule were obtained intraoperatively. A histological grading (Mankin score) was obtained, and additional histological findings were also reported. In patients with RA the clinical and pathological diagnoses were concordant in 37 (74%) and discrepant in 13 patients (26%). In patients with OA there was concordance in 30 (60%) and discrepancy in 20 patients (40%). Discrepancies were additional findings such as focal osteonecrosis amyloidosis or crystal deposits. Discordance (management alteration) did not occur in any case. Histological evaluation of the capsule and the synovium was more informative than evaluation of bone. Calcium pyrophosphate (CPPD) and amyloid was frequently found in OA suggesting that these substances may contribute to joint damage, and control of their production by therapeutic means may prevent degeneration.

Amyloid deposition in osteoarthritis of the hip.

PURPOSE: The aim of this study was to examine the frequency of amyloid deposition in patients with end-stage hip osteoarthritis (OA). Further, their impact on the clinical situation and the OA severity were analyzed. METHODS: Fifty patients with OA who consecutively underwent total hip replacement were prospectively evaluated. The X-rays of the patients were analyzed using a radiological score (Kellgren-Lawrence) to quantify the amount of radiological changes. A clinical score [Harris hip score (HHS)] was preoperatively calculated for every patient. Specimens from the femoral head of bone and cartilage, and additionally 1 cm(2) of the capsule, were obtained from every patient intraoperatively for analyzing the amyloid deposition histologically. A histological grading was also performed. On a subset of patients with amyloid deposits, the subtypes were characterized immunohistologically. RESULTS: The only subtype of amyloid was ATTR. There was a high, significant correlation between articular amyloid deposition and the age of the patient at the time of the operation. No correlation was found for any other measured item, such as signs of inflammation in the blood samples, histological grading, radiological score or clinical score. CONCLUSIONS: The frequency of amyloid deposits in the joint increases with age, and it can generally be considered to be of no pathologic significance, since a correlation with the radiological and histological changes was ruled out by our study. Thus, the presence of ATTR amyloid may simply be an incidental finding in aged joints.

Long-term results of the thrust plate prosthesis in patients with rheumatoid arthritis: a minimum 10-year follow-up.

BACKGROUND: The thrust plate prosthesis (TPP) is a hip prosthesis with metaphyseal fixation to the femur. Because the bone quality is reduced in patients with rheumatoid arthritis, this kind of fixation may have a higher failure rate than conventional stemmed endoprostheses in these patients. The aim of this investigation was to analyze the long-term results obtained with the TPP in patients with rheumatoid arthritis. METHODS: The survival of 51 implants in 46 patients with rheumatoid arthritis was analyzed. Clinical (Harris hip score) and radiological examinations were carried out on 47 of the 51 TPPs, with a post implantation follow-up period of at least 10 years. The Kaplan-Meier method was used to estimate the survival rates of the TPPs, with surgical revision due to the femoral implant as the endpoint of the investigation. RESULTS: The Harris hip score increased from 42.4 ± 6.5 points preoperatively to 86.6 ± 10.1 points at follow-up. The failure rate was 23% (6 aseptic and 5 septic loosening). The total rate of revision amounted to 36.2% (17/47 TPPs): six aseptic loosening of TPPs, five septic loosening of TPPs, four aseptic loosening of the acetabular component, one removal of the fishplate of a TPP, and one femoral fracture. Additionally one TPP showed radiolucent lines indicating prosthetic loosening. Revision surgeries to stemmed endoprostheses of the hip were without severe problems in any patients. CONCLUSIONS: The failure rate of the TPP was distinctly higher than that for conventional stemmed endoprostheses regarding aseptic and septic revisions. In cases with loosening of the TPP the preservation of the diaphyseal bone of the femur is poor and the TPP mostly needs a revision to a cemented stem. Thus, the estimated advantage of the TPP versus cementless stemmed prostheses for patients with rheumatoid arthritis is not evident. In conclusion, there is no evidence form this study to support the use of the TPP in this group of patients.

Treatment of osteochondritis dissecans of the femoral condyle with autologous bone grafts and matrix-supported autologous chondrocytes.

The objective of this study was to determine the clinical outcome of combined bone grafting and matrix-supported autologous chondrocyte transplantation in patients with osteochondritis dissecans of the knee. Between January 2003 and March 2005, 21 patients (mean age 29.33 years) with symptomatic osteochondritis dissecans (OCD) of the medial or lateral condyle (grade III or IV) of the knee underwent reconstruction of the joint surface by autologous bone grafts and matrix-supported autologous chondrocyte transplantation. Patients were followed up at three, six, 12 and 36 months to determine outcomes by clinical evaluation based on Lysholm score, IKDC and ICRS score. Clinical results showed a significant improvement of Lysholm-score and IKDC score. With respect to clinical assessment, 18 of 21 patients showed good or excellent results 36 months postoperatively. Our study suggests that treatment of OCD with autologous bone grafts and matrix-supported autologous chondrocytes is a possible alternative to osteochondral cylinder transfer or conventional ACT.

Articular cartilage mineralization in osteoarthritis of the hip.

BACKGROUND: The aim of this study was to examine the frequency of articular cartilage calcification in patients with end-stage hip OA. Further, its impact on the clinical situation and the OA severity are analyzed. METHODS: Eighty patients with OA of the hip who consecutively underwent total hip replacement were prospectively evaluated, and 10 controls were included. The patients' X-rays were analyzed for the presence of articular cartilage mineralization. A Harris Hip Score (HHS) was preoperatively calculated for every patient.Slab specimens from the femoral head of bone and cartilage and an additional square centimeter of articular cartilage from the main chondral defect were obtained from each patient for analysis of mineralization by digital contact radiography (DCR). Histological grading was also performed. In a subset of 20 patients, minerals were characterized with an electron microscope (FE-SEM). RESULTS: Calcifications were seen in all OA cartilage and slab specimens using DCR, while preoperative X-rays revealed calcification in only 17.5%. None of the control cartilage specimens showed mineralization. There was a highly significant inverse correlation between articular cartilage calcification and preoperative HHS. Histological OA grade correlated positively with the amount of matrix calcification. FE-SEM analysis revealed basic calcium phosphate (BCP) as the predominant mineral; CPPD crystals were found in only two patients. CONCLUSIONS: Articular cartilage calcification is a common event in osteoarthritis of the hip. The amount of calcification correlates with clinical symptoms and histological OA grade.

Dislocation of the polyethylene liner in hip arthroplasty: 6 patients with dislocation within 3 years.

We revised 6 patients with early destruction of the liner in a cementless press-fit acetabular cup. They had no signs of infection or evidence of trauma. The failures were probably due to rotation of the liner inside the metal shell and destruction of the polyethylene by the cutting edge of the metal. This early complication may be difficult to diagnose because of normal radiographs. We suggest that the manufacturer should provide the insert with a metal marker to make this complication easier to detect.