Complete excision of the infrapatellar fat pad is associated with patellar tendon shortening after primary total knee arthroplasty.

BACKGROUND: Patella baja is a potentially disabling and difficult-to-treat complication following total knee arthroplasty (TKA). We investigated whether complete or partial excision of the fat pad has an effect on the length of the patellar tendon following TKA. METHODS: A retrospective review of patient radiographs was performed. One hundred and eleven consecutive patients who underwent primary TKA for osteoarthritis using the same components by two consultants were selected. Seventy-two patients underwent complete excision of the fat pad, whilst 39 had partial excision as per consultant practice. Patellar height was measured using the Caton-Deschamps Index (CDI) on immediate postoperative radiographs and at a minimum follow-up of 1 year. RESULTS: In the complete excision group, the mean CDI changed from 0.54 immediately postoperatively to 0.45 at a minimum follow-up of 1 year (p < 0.0001) indicating shortening of the patellar tendon, and eight patients reported anterior knee pain. The partial excision group's mean CDI changed from 0.76 to 0.75 (p = 0.231). An analysis of variance showed that the effect of complete fat pad excision on patella tendon length was significant, F(1, 109) = 15.273, p < 0.001. CONCLUSION: At a minimum follow-up of 1 year, the patellar tendon length shortened significantly in the group of patients with complete fat pad excision. With partial excision, there was no significant change in tendon length. Complete excision of the fat pad should therefore be avoided wherever possible in an attempt to avoid patella baja. LEVEL OF EVIDENCE: II.

Management of extreme patella baja using in-situ hamstring tendon autograft.

Successful total knee arthroplasty requires a functioning extensor mechanism. Patella baja following total knee arthroplasty can cause extensor mechanism dysfunction and produce poor outcomes. We present a case of severe patella tendon shortening following revision total knee arthroplasty with almost complete ankylosis of the distal pole of the patella to the proximal tibia. This resulted in effective extensor mechanism dysfunction with pain and severely limited knee flexion. We report a novel method of reconstruction of the patella tendon at the time of revision arthroplasty together with the one-year clinical outcome and review of the literature.

Using semifield studies to examine the effects of pesticides on mobile terrestrial invertebrates.

Many farmers rely on regular pesticide applications to avoid losses from arthropod pests and the diseases they vector. However, widespread and injudicious use of pesticides is detrimental to the environment, poses a health risk, and undermines biocontrol services. Researchers are increasingly required to develop techniques to quantify the trade-offs and risks associated with pesticides. Laboratory studies, though useful for assessing short-term impacts (e.g., mortality), cannot detect longer-term or indirect effects that can potentially be assessed using semifield studies. Here we review the range and scope of studies that have used semifield methods for regulatory testing and risk assessment of pesticides and for understanding the community-level effects of pesticide use in agricultural landscapes. We include studies on target and nontarget species, with an emphasis on quantifying effects when the target species is highly mobile. We suggest improvements in the design and analysis of semifield studies to more effectively assess effects on highly mobile species.

Causes of failure of the Kinemax Plus total knee replacement in the first five years.

In order to investigate whether any single batch of polyethylene inserts was responsible for premature failure of total knee replacements (TKR), we performed a retrospective database review of 1133 consecutive primary Kinemax Plus TKR performed by 2 surgical teams between January 1992 and January 2001 at our institution. Cases re-operated in any way within 5 years of the index arthroplasty were identified, case notes studied and radiographs reviewed. The causes contributing to the premature failure of the implants were identified where possible and the polyethylene lot numbers were recorded. Nineteen cases were known to have been revised, 7 cases for deep infection of the prosthesis and 12 for aseptic failure. In 10 cases, an identifiable technical error had contributed to the early failure of the implant. In 4 of these cases, there was inadequate tissue balancing in patients with a significant pre-operative valgus deformity. In 2 cases, the tibial base plate was inserted in a varus mal-alignment. There was one extended tibial component, one internally rotated femoral component, one oversized femoral component and one femoral component with inadequate fixation. Two further cases failed aseptically, one with a fracture of the medial tibial plateau and one idiopathic. The lot numbers of the polyethylene inserts were all different. This study confirms that the premature failure rate of the Kinemax Plus TKR is low. Although a "bad batch" of polyethylene has been suggested as a cause for early failure in TKR, in this series, surgical error was the predominant cause.

Metal-specific differences in levels of DNA damage caused by synovial fluid recovered at revision arthroplasty.

Previous research has shown an increase in chromosomal aberrations in patients with worn implants. The type of aberration depended on the type of metal alloy in the prosthesis. We have investigated the metal-specific difference in the level of DNA damage (DNA stand breaks and alkali labile sites) induced by culturing human fibroblasts in synovial fluid retrieved at revision arthroplasty. All six samples from revision cobalt-chromium metal-on-metal and four of six samples from cobalt-chromium metal-on-polyethylene prostheses caused DNA damage. By contrast, none of six samples from revision stainless-steel metal-on-polyethylene prostheses caused significant damage. Samples of cobalt-chromium alloy left to corrode in phosphate-buffered saline also caused DNA damage and this depended on a synergistic effect between the cobalt and chromium ions. Our results further emphasise that epidemiological studies of orthopaedic implants should take account of the type of metal alloy used.

Lipoma arborescens of the knee.

Lipoma arborescens (diffuse articular lipomatosis) is a rare, benign intra-articular lesion of unknown aetiology. It is characterised by villous proliferation of the synovium and diffuse replacement of the subsynovial tissue by mature fat cells. It forms part of the differential diagnosis for a slowly progressive chronically swollen knee. We present a very rare case of bilateral involvement of the knee and discuss the symptoms, diagnosis and treatment of this condition.

An unusual lymphocytic perivascular infiltration in tissues around contemporary metal-on-metal joint replacements.

BACKGROUND: Metal-on-metal bearing surfaces have been reintroduced for use during total hip replacement. To assess tissue reactions to various types of articulations, we studied the histological appearance of periprosthetic tissues retrieved from around metal-on-metal and metal-on-polyethylene total hip replacements and compared these findings with the appearance of control tissues retrieved at the time of primary arthroplasty. METHODS: Periprosthetic tissues were obtained at the time of revision of twenty-five cobalt chromium-on-cobalt chromium, nine cobalt chromium-on-polyethylene, and ten titanium-on-polyethylene total hip arthroplasties. Control tissues were obtained from nine osteoarthritic hips at the time of primary total hip arthroplasty. Each tissue sample was processed for routine histological analysis, and sections were stained with hematoxylin and eosin. Quantitative stereological analysis was performed with use of light microscopy. RESULTS: Tissue samples obtained from hips with metal-on-metal implants displayed a pattern of well-demarcated tissue layers. A prominent feature, seen in seventeen of twenty-five tissue samples, was a pattern of perivascular infiltration of lymphocytes. In ten of the tissue samples obtained from hips with metal-on-metal prostheses, there was also an accumulation of plasma cells in association with macrophages that contained metallic wear-debris particles. The surfaces of tissues obtained from hips with metal-on-metal prostheses were more ulcerated than those obtained from hips with other types of implants, particularly in the region immediately superficial to areas of perivascular lymphocytic infiltration. The lymphocytic infiltration was more pronounced in samples obtained at the time of revision because of aseptic failure than in samples retrieved at the time of autopsy or during arthrotomy for reasons other than aseptic failure. Total-joint-replacement and surface-replacement designs of metal-on-metal prostheses were associated with similar results. Tissue samples obtained from hips with metal-on-polyethylene implants showed far less surface ulceration, much less distinction between tissue layers, no pattern of lymphocytic infiltration, and no plasma cells. The inflammation was predominantly histiocytic. Tissues retrieved from hips undergoing primary joint replacement showed dense scar tissue and minimal inflammation. CONCLUSIONS AND CLINICAL RELEVANCE: The pattern and type of inflammation seen in periprosthetic tissues obtained from hips with metal-on-metal and metal-on-polyethylene implants are very different. At the present time, we do not know the prevalence or clinical implications of these histologic findings, but we suggest that they may represent a novel mode of failure for some metal-on-metal joint replacements.

The sulcus angle and malalignment of the extensor mechanism of the knee.

Anterior knee pain due to dysplasia of the extensor mechanism is common. We have studied 137 knees (103 patients) in order to identify a rapid and reproducible radiological feature which would indicate the need for further analysis. Overall, 67 knees (49%) had at least one radiological abnormality; 70 (51%) were considered normal. There were five cases of Dejour type-3 dysplasia of the femoral trochlea, nine of type-2 and 12 of type-1. There were 49 cases of patella alta and five of patella infera. Four knees had an abnormal lateral patellofemoral angle (patellar tilt), and in 15 knees there was more than one abnormality. Classification of trochlear dysplasia was difficult and showed poor reproducibility. This was also true for the measurement of the lateral patellofemoral angle. Patellar height was more easily measured but took time. The sulcus angle is an easily and rapidly measurable feature which was reproducible and was closely related to other features of dysplasia of the extensor mechanism. The finding of a normal sulcus angle suggested that seeking other radiological evidence of malalignment of the extensor mechanism was unlikely to reveal additional useful information. The severity of other features of dysplasia of the extensor mechanism correlated with increasing sulcus angle.

Plain radiography in the degenerate knee. A case for change.

We took posteroanterior weight-bearing radiographs, both with the joint fully extended and in 30 degrees of flexion, in a consecutive series of 50 knees in 37 patients referred for the primary assessment of pain and/or stiffness. These radiographs were reported 'blind' both by an orthopaedic surgeon and a radiologist. Direct measurement of the joint space, together with grading of the severity of erosion according to the Ahlback criteria, was undertaken. Any other abnormality present was also documented. The radiographs of the knees in 30 degrees of flexion consistently showed more advanced erosion in both the medial (p = 0.001) and the lateral (p = 0.0001) tibiofemoral compartments, when compared with those of knees in full extension. The Ahlback classification of 25 joints was altered, in some cases by several grades, by the flexed position of the joint. In every case in which another abnormality was identified on the radiograph in full extension, it was also noted on that of the knee in 30 degrees of flexion. In a further four cases, additional pathology could only be seen in the flexed knee. Every patient was able to complete the radiological examination without difficulty. Our study supports the adoption of a weight-bearing view in 30 degrees of flexion as the standard posteroanterior radiograph for the assessment of tibiofemoral osteoarthritis in patients over 50 years of age.

Expanding mesh stent in the emergency treatment of Boerhaave's syndrome.

Boerhaave's syndrome, or spontaneous esophageal perforation, is a life threatening condition demanding early diagnosis and rapid aggressive management to prevent fulminant mediastinitis and death. We describe a patient treated in an emergency situation with an expanding esophageal mesh stent to bridge the esophageal rent together with chest and mediastinal drainage, resulting in complete recovery and return to the community. We also describe the partial recovery of the stent in the convalescent period.

Screening for ovarian cancer: a pilot randomised controlled trial.

BACKGROUND: The value of screening for ovarian cancer is uncertain. We did a pilot randomised trial to assess multimodal screening with sequential CA 125 antigen and ultrasonography. METHODS: Postmenopausal women aged 45 years or older were randomised to a control group (n=10,977) or screened group (n=10,958). Women randomised to screening were offered three annual screens that involved measurement of serum CA 125, pelvic ultrasonography if CA 125 was 30 U/mL or more, and referral for gynaecological opinion if ovarian volume was 8.8 mL or more on ultrasonography. All women were followed up to see whether they developed invasive epithelial cancers of the ovary or fallopian tube (index cancers). FINDINGS: Of 468 women in the screened group with a raised CA 125, 29 were referred for a gynaecological opinion; screening detected an index cancer in six and 23 had false-positive screening results. The positive predictive value was 20.7%. During 7-year follow-up, ten further women with index cancers were identified in the screened group and 20 in the control group. Median survival of women with index cancers in the screened group was 72.9 months and in the control group was 41.8 months (p=0.0112). The number of deaths from an index cancer did not differ significantly between the control and screened groups (18 of 10,977 vs nine of 10,958, relative risk 2.0 [95% CI 0.78-5.13]). INTERPRETATION: These results show that a multimodal approach to ovarian cancer screening in a randomised trial is feasible and justify a larger randomised trial to see whether screening affects mortality.

Risk of diagnosis of ovarian cancer after raised serum CA 125 concentration: a prospective cohort study.

OBJECTIVE: To determine the risk of invasive epithelial ovarian cancer and fallopian tube cancer associated with a raised concentration of the tumour marker CA 125 in asymptomatic postmenopausal women. DESIGN: Serum CA 125 concentration was measured annually in study participants for one to four years. Participants with a concentration > or = 30 U/ml were recalled for abdominal ultrasonography. Follow up was by annual postal questionnaire. SETTING: General practice, occupational health departments, ovarian cancer screening unit in a teaching hospital. SUBJECTS: 22,000 volunteers, all postmenopausal women > or = 45 years of age; recruited between 1 June 1986 and 1 May 1990. INTERVENTION: Surgical investigation if the ultrasound examination was abnormal. MAIN OUTCOME MEASURES: Cumulative and relative risk of developing an index cancer (invasive epithelial cancer of the ovary or fallopian tube) after a specified CA 125 result. RESULTS: 49 index cancers developed in the study population during a mean follow up of 6.76 years. The overall cumulative risk of developing an index cancer was 0.0022 for the entire study population and was lower for women with a serum CA 125 concentration < 30 U/ml (cumulative risk 0.0012) but was appreciably increased for women with a concentration > or = 30 U/ml (0.030) and > 100 U/ml (0.149). Compared with the entire study population the relative risk of developing an index cancer within one year and five years was increased 35.9-fold (95% confidence interval 18.3 to 70.4) and 14.3-fold (8.5 to 24.3) respectively after a serum CA 125 concentration > or = 30 U/ml and 204.8-fold (79.0 to 530.7) and 74.5-fold (31.1 to 178.3) respectively after a concentration > or = 100 U/ml. CONCLUSION: CA 125 is a powerful index of risk of ovarian and fallopian tube cancer in asymptomatic postmenopausal women.

Combinations of multiple serum markers are superior to individual assays for discriminating malignant from benign pelvic masses.

To determine whether measurement of the levels of multiple tumor markers in the preoperative serum of women presenting with a pelvic mass distinguished benign from malignant disease better than the assay of CA 125 alone, sera from 429 patients, 192 of whom had malignant histology, were assayed for 8 different markers: CA 125, macrophage colony-stimulating factor, OVX1, lipid-associated sialic acid (LASA), CA15-3, CA72-4, CA19-9, and CA54/61. The sensitivity and specificity of CA 125 alone (> 35 U/ml) was 78.1 and 76.8%, respectively. A panel consisting of CA 125, OVX1, LASA, CA15-3, and CA72-4 had a sensitivity of 83.3% and specificity of 84.0% when two or more markers were elevated. Using the concentrations of these five markers, logistic regression analysis had a sensitivity of 85.4% and a specificity of 83.1%. Considering the values of markers in different sequences, classification and regression tree analysis substantially improved the sensitivity to 90.6% and the specificity to 93.2%. When applied in clinical practice this approach could improve the management of women presenting with a pelvic mass and may also have application in screening for ovarian cancer.

The measurement of urinary beta core fragment in conjunction with serum CA125 does not aid the differentiation of malignant from benign pelvic masses.

The urinary concentration of the renal metabolite of the beta subunit of human chorionic gonadotropin (beta core) has been proposed as a tumor marker in certain nontrophoblastic malignancies including those of the female genital tract. A previous study investigated the use of urinary beta core in conjunction with serum CA125 in distinguishing malignant from benign pelvic masses and showed that the combined test improved the overall sensitivity to 88%; this was greater than that for either test alone. However, the cutoff levels used to distinguish normal from abnormal were approximately six times greater than those generally used for CA125 and four to five times lower than those used for beta core in our laboratory. Furthermore there was no recognition of the possible difference in normal levels of beta core between pre- and postmenopausal women. We have examined a similar group of cases using our cutoff levels for urinary beta core of 0.36 ng/ml in premenopausal women and 0.48 ng/ml in postmenopausal women and 35 u/ml for CA125. We show that measurement of CA125 is substantially more sensitive that that of beta core and that the combination of beta core with CA125 does not improve the overall sensitivity of the test. However, there was a small improvement in positive predictive value if both tests were positive (97.5%) and of specificity when one or the other test was negative (98.5%).

The adnexal mass: benign or malignant? Evaluation of a risk of malignancy index.

OBJECTIVE: To validate a risk of malignancy index incorporating menopausal status, serum CA 125 level and pelvic ultrasound features in the pre-operative diagnosis of ovarian cancer. DESIGN: A retrospective observational study. SETTING: Department of Obstetrics and Gynaecology, The Royal London Hospital. SUBJECTS: One hundred and twenty-four women admitted consecutively to the gynaecology department for surgical exploration of an adnexal mass. MAIN OUTCOME MEASURES: The sensitivities and specificities of menopausal status, serum CA 125 level and ultrasound features, in isolation and combined (the risk of malignancy index (RMI)), for diagnosing ovarian cancer. RESULTS: Tested on a new population of women, the RMI retained the high sensitivity for diagnosing ovarian cancer seen in the original report describing its derivation. The specificity, however, was lower. The study confirmed that the RMI is more accurate than the individual criteria in diagnosing ovarian cancer, and was comparable with other scoring systems. CONCLUSIONS: The risk of malignancy index is a simple scoring system for ovarian cancer. Application of the risk of malignancy index in clinical practice may provide a rational basis for specialist referral of patients with ovarian cancer before diagnostic surgery.

Prevalence screening for ovarian cancer in postmenopausal women by CA 125 measurement and ultrasonography.

OBJECTIVE: To assess the performance of the sequential combination of serum CA 125 measurement and ultrasonography in screening for ovarian cancer. DESIGN: The serum CA 125 concentration of each subject was determined and those with a concentration > or = 30 U/ml were recalled for abdominal ultrasonography. If ultrasonography gave abnormal results surgical investigation was arranged. Volunteers were followed up by annual postal questionnaire. SETTING: General practice, occupational health departments, ovarian cancer screening clinic. SUBJECTS: 22,000 women volunteers who were postmenopausal and aged over 45 years. MAIN OUTCOME MEASURES: Apparent sensitivity, specificity, positive predictive value, years of cancer detected. RESULTS: 41 women had a positive screening result and were investigated surgically. 11 had ovarian cancer (true positive result) and 30 had other disorders or no abnormality (false positive result). Of the 21,959 volunteers with a negative screening result, eight subsequently presented clinically with ovarian cancer (false negative result) and 21,951 had not developed ovarian cancer during follow up (apparent true negative result). The screening protocol achieved a specificity of 99.9%, a positive predictive value of 26.8%, and an apparent sensitivity of 78.6% and 57.9% at one year and two year follow up respectively. The estimated number of years of cancer detected by the prevalence screen was 1.4 years. CONCLUSIONS: This screening protocol is highly specific for ovarian cancer and can detect a substantial proportion of cases at a preclinical stage. Further investigation is required to determine the effect of the screening protocol on the ratio of early to late stage disease detected and on mortality from ovarian cancer.

Glucagon-producing pancreatic endocrine tumors in two dogs with superficial necrolytic dermatitis.

A newly recognized disease in dogs, ulcerative dermatosis associated with diabetes mellitus (diabetic dermatopathy), was diagnosed in 2 dogs with pancreatic endocrine tumors that had immunohistologic evidence of glucagon production. Dogs developed diabetes mellitus in the later stages of the illness, months after the skin disease was first observed. Liver disease was identified and characterized by high serum alkaline phosphatase and alanine transaminase activities. Clinically, erythema and crusting involved the footpads, the face, perioral and genital skin, and ventrum. Histologically, skin lesions were intercellular and intracellular edema and necrosis of the upper half of the epidermis and diffuse parakeratosis. Clinically and histologically, skin lesions closely resembled necrolytic migratory erythema of people, a skin disease that usually is associated with a glucagon-secreting pancreatic endocrine tumor and diabetes mellitus (glucagonoma syndrome): The morphologically descriptive term, superficial necrolytic dermatitis, was preferred over the previously proposed names hepatocutaneous syndrome and diabetic dermatopathy, which each connote only a single feature of the disease.

A 20-year prospective study of cirrhosis.

A total of 512 people from a defined population in west Birmingham served by a district general hospital were found to have cirrhosis in the period 1959-76. The annual incidence rose from 5.6 per 100 000 to a peak of 15.3 per 100 000 in 1974. This was due to an increase in the incidence of alcoholic cirrhosis, which in the last six years accounted for two-thirds of cases. The proportion of patients with decompensated cirrhosis when first seen (65%) did not alter during the 18 years. This was reflected in a death rate of 78% among the 468 patients traced up to the end of 1978. Liver failure, hepatoma, and gastrointestinal haemorrhage accounted for almost three-quarters of the deaths. The proportion of patients who survived for five years was 36% for alcoholic cirrhosis, 14% for cryptogenic cirrhosis, and 60% for chronic active hepatitis, and these figures too remained constant throughout the 18 years. Modern methods of treatment for decompensated cirrhosis did not improve prognosis and only abstention in patients with alcoholic cirrhosis had a beneficial effect on survival. Since alcoholic cirrhosis is now the most common form of the disease it is important to recognise those at risk and to encourage abstinence; also, more efforts are needed to identify the causes of cryptogenic cirrhosis. Whatever the cause, cirrhosis needs to be diagnosed before decompensation occurs, if treatment is to have any effect.