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Cancer risk after metal on metal and polyethylene on metal total hip arthroplasty.

The incidence of cancer after metal on metal total hip arthroplasty (McKee-Farrar) and polyethylene on metal total hip arthroplasty (Brunswik, Lubinus) was compared with that of the general population in Finland. The mean followup time for the patients who had metal on metal total hip arthroplasty was 15.7 (9092 person years) and for the patients who had polyethylene on metal total hip arthroplasty it was 12.5 years (19,846 person years). One hundred thirteen malignant cancers were observed in patients who had metal on metal total hip arthroplasty and 212 were observed in patients who had polyethylene on metal total hip arthroplasty. The standardized incidence ratio for all cancers of the metal on metal arthroplasty group was 0.95 (95% confidence limits 0.79-1.13) and that of the polyethylene on metal arthroplasty group was 0.76 (95% confidence limits 0.68-0.86). The risk of total cancer in the patients who had metal on metal total hip arthroplasty was 1.23-fold compared with that of the patients who had polyethylene on metal total hip arthroplasty. Both groups had significantly less lung cancer than the general population: the leukemia incidence in the patients who had metal on metal total hip arthroplasty was slightly increased (observed to experienced 7/3.03, standardized incidence ratio 0.61; 95% confidence limits 0.17-1.56). The leukemia rate of the patients who had metal on metal total hip arthroplasty was 3.77-fold compared with that of the patients who had polyethylene on metal total hip arthroplasty, but this difference was not statistically significant. No sarcomas were observed at the site of the prosthesis. The incidence of the other forms of cancers did not differ significantly from those in the general population. The observed variation in the incidence of different cancers among patients who had total hip arthroplasty compared with the general population suggests that factors other than total hip arthroplasty play a major role in the origin of cancer.

CANCER RISK AFTER MCKEE-FARRAR TOTAL HIP REPLACEMENT

Cancer incidence in 433 McKee-Farrar total hip replacement patients, operated on between 1967 and 1973, was examined for 5729 person-years, to the end of 1981. The expected number of natural deaths was slightly higher than observed, suggesting some selection of the operated patients. The risk of total cancer incidence did not increase, but the risk for site-specific cancer did because there were no cases of kidney or bladder cancer, or rare forms of cancer. The risk of leukemias and lymphomas increased, and the risk of breast cancer decreased; these results were surprisingly similar to those of a study from New Zealand. This study concluded that patients with total hip prostheses have a cancer morbidity differing from the general population. The role of chrome-cobalt-molybdenum alloy in carcinogenesis requires further investigation.

Treatment with and without Initial Stabilizing Surgery for Primary Traumatic Patellar Dislocation A Prospective Randomized Study

BACKGROUND There is no consensus about the management of acute primary traumatic patellar dislocation in young physically active adults. The objective of this study was to compare the clinical outcomes after treatment with and without initial stabilizing surgery for primary traumatic patellar dislocation in young adults. METHODS Forty young adults, thirty-seven men and three women with a median age of twenty years (range, nineteen to twenty-two years), who had an acute primary traumatic patellar dislocation were randomly allocated to be treated with initial surgical stabilization (eighteen patients, with each receiving one of two types of initial stabilizing procedures) or to be managed with an orthosis (twenty-two patients, including four who had osteochondral fragments removed arthroscopically). After a median of seven years, thirty-eight patients returned for a follow-up examination. Redislocations, subjective symptoms, and functional limitations were evaluated. Radiographs and magnetic resonance images were obtained at the time of randomization, and twenty-nine (76%) patients underwent magnetic resonance imaging at the time of final follow-up. RESULTS A hemarthrosis as well as injuries of the medial retinaculum and the medial patellofemoral ligament were found on magnetic resonance imaging in all patients at the time of randomization. During the follow-up period, six of the twenty-one nonoperatively treated patients and none of the seventeen patients treated with surgical stabilization had a redislocation (p = 0.02). Four nonoperatively treated patients and two patients treated with surgical stabilization reported painful patellar subluxation. The median Kujala scores were 91 points for the surgically treated patients and 90 points for the nonoperatively treated patients. Thirteen patients in the surgically treated group and fifteen in the nonoperatively treated group regained their former physical activity level. At the time of follow-up, a full-thickness patellofemoral articular cartilage lesion was detected on magnetic resonance imaging in eleven patients; the lesions were considered to be unrelated to the form of treatment. CONCLUSIONS In a study of young, mostly male adults with primary traumatic patellar dislocation, the rate of redislocation for those treated with surgical stabilization was significantly lower than the rate for those treated without surgical stabilization. However, no clear subjective benefits of initial stabilizing surgery were seen at the time of long-term follow-up.

Femoral Avulsion of the Medial Patellofemoral Ligament after Primary Traumatic Patellar Dislocation Predicts Subsequent Instability in Men: A Mean 7-Year Nonoperative Follow-Up Study

Background The clinical relevance of medial patellofemoral ligament (MPFL) injury location in primary patellar dislocation has not been studied. Hypothesis Prognosis after primary traumatic patellar dislocation may vary by MPFL injury location. Study Design Cohort study; Level of evidence, 3. Methods The initial magnetic resonance imaging (MRI) findings in 53 patients with identical nonoperative management were retrospectively analyzed for medial restraint injuries. The MPFL injury sites were classified as follows: femoral, midsubstance, and patellar. Magnetic resonance imaging was used to assess initial and control articular cartilage lesions in the patellofemoral joint. After a mean follow-up of 7 years, 42 patients were evaluated for redislocations, subjective symptoms, and functional limitations. Results Based on the initial MRIs, MPFL rupture was classified as femoral in 35 patients, midsubstance in 11, and patellar in 7. At follow-up, 15 patients reported an unstable patella (13 femoral, 1 patellar, 1 midsubstance; P =. 01) and 9 reported patellar redislocations (8 femoral, 1 midsubstance; P =. 05). The proportion of patients who regained their preinjury activity level was significantly smaller among those with femoral MPFL injury than among those with midsubstance or patellar MPFL injury (P =. 05). The median Kujala score was as follows: 90 for femoral, 91 for patellar, and 96 for midsubstance (P =. 76). Control MRI showed full-thickness patellofemoral cartilage lesions in 50% of the patients, unrelated to MPFL injury location. Conclusion An MPFL avulsion at the femoral attachment in primary traumatic patellar dislocations predicts subsequent patellar instability. The authors suggest that MPFL injury location be taken into account when planning treatment of primary traumatic patellar dislocation.

Arthroscopic Surgery for Primary Traumatic Patellar Dislocation: A Prospective, Nonrandomized Study Comparing Patients Treated with and without Acute Arthroscopic Stabilization with a Median 7-Year Follow-up

Background No data exist whether patients with primary traumatic patellar dislocation benefit from initial arthroscopic medial repair surgery. Purpose To compare long-term outcomes of patients treated with acute arthroscopic stabilization for patellar dislocation with those treated nonoperatively except for removal of loose bodies. Study Design Cohort study; Level of evidence, 2. Methods The study group included 76 consecutive military recruits (72 men, 4 women), with a median age of 20 years (range, 19–22) at the time of dislocation. Thirty patients (group 1) underwent initial arthroscopic medial retinacular repair, and 46 patients (group 2) were treated without stabilizing surgery, including 11 who had osteochondral fragments arthroscopically removed. Patients with previous patellar dislocations or instability were excluded. Aftercare was identical in both groups. Redislocations, subjective symptoms, and functional limitations were evaluated after a median 7-year follow-up. Results Sixty-one (80%) patients participated in a follow-up examination. At final follow-up, 8 (23%) redislocations occurred in group 2 and 5 (19%) in group 1 (P = .84). Eight (23%) patients in group 2 and 3 (12%) in group 1 reported patellar subluxations (P = .18). In group 1, 81% regained their preinjury activity level compared with 56% in group 2 (P = .05). Functional outcomes were good in both groups (Kujala scores: 87 for group 1 and 90 for group 2) (P = .22). Regarding the presence of osteoarthritic characteristics in the patellofemoral joint, no statistically significant differences were found between the groups. Conclusions Initial arthroscopic medial retinacular repair was not followed by improved patellar stability nor reduced incidence of redislocations compared with nonoperative (except for removal of loose bodies) treatment. Acute arthroscopic medial retinacular repair allowed patients to better regain preinjury activity level than in patients not undergoing retinacular repair. The decision to stabilize the patella by initial arthroscopic surgery should be made with caution.

Bilateral distal biceps tendon avulsions with use of anabolic steroids.

A case of a young body-builder who had ingested megadoses of anabolic-androgenic steroids (AAS) for 6 yr and who sustained bilateral avulsions of the distal biceps tendon is presented. Explosive behavior, painful gynecomastia, and a slight hypertrophy of both the left and right ventricular walls of the heart were other possible adverse effects of AAS in this patient. Reinsertion of both distal biceps tendons to the radial tuberosity was performed according to the Boyd-Anderson technique and a good result was achieved.

Cancer incidence in finnish hip replacement patients from 1980 to 1995

Nationwide, computer-based reporting of all arthroplasties performed in Finland was started in January 1980. Using data from these records, a cohort of 31,651 polyethylene-on-metal total hip arthroplasty (THA) patients was followed up for cancer, using Finnish Cancer Registry data, from 1980 to 1995. During follow-up, 2,367 cancers were observed. There were statistically significantly fewer cancers among the THA patients (standardized incidence ratio [SIR], 0.90; 95% confidence interval [CI], 0.87-0.93). SIRs for cancers of the lung (0.69) and stomach (0.77) were significantly below unity. There was no significantly increased risk at any site. The SIR for cancer overall in male THA patients was below unity during the first 3 years after THA but returned to unity thereafter. The low SIR among men during the first 3 years was largely because the lung cancer SIR was 0.47 (95% CI, 0.35-0.62). In women, the SIR remained around 0.93 throughout follow-up. The SIR for stomach cancer was below unity only in women (SIR, 0.67; 95% CI, 0.51-0.86). For cancer of the urinary bladder, the SIR during the first 3 years after THA was below unity but later slightly above it (SIR, 1.24 in relation to > or =3 years of follow-up; 95% CI, 0.99-1.52). For myeloma and leukemia, SIRs were greater than unity only for THA patients followed up for 3 to 9 years. The study findings, in contrast to previously reported findings, do not indicate that there is any increased risk of hematopoietic cancers after THA using polyethylene-on-metal prostheses. SIRs relating to soft tissue cancers and bone sarcomas did not differ significantly from unity. No sarcoma was observed at the site of a prosthesis. THA seems to play no major role in cancer causation.

Decreased cancer risk in patients who have been operated on with total hip and knee arthroplasty for primary osteoarthrosis: a meta-analysis of 6 Nordic cohorts with 73,000 patients.

: 3 Nordic cohorts of total hip (THA) and total knee arthroplasty (TKA) in patients operated on for primary osteoarthrosis during 1967-1995 were partly adapted and combined for meta-analysis. THA was performed in 49,000 patients and TKA in 24,000 totaling 497,000 person years. The mean and maximum follow-up times were 6.8 and 30 years, respectively. Standardized incidence ratios (SIRs) with 95% confidence intervals (95% CI) were calculated for the observed and expected number of cancers. The expected numbers were based on national incidence rates. The overall SIRs as well as the site-specific ones were similar in the THA and TKA patients. The observed number of cancers at all sites was 7,639 and the expected one was 8,202 (SIR 0.93, 95% CI 0.91-0.95). The SIRs for lung cancer (0.69, 0.64-0.75) and laryngeal cancer (0.64, 0.44-0.92) were reduced. The incidence was also low for cancers of the stomach (SIR 0.76, 0.67-0.84), colon (SIR 0.86, 0.79-0.93) and rectum (SIR 0.89, 0.80-0.98). Among TKA patients, the only increases in SIRs were seen in cancers of the endometrium (SIR 1.36, 1.05-1.74), prostate (SIR 1.19, 1.02-1.38) and, among both THA and TKA patients, in skin melanoma (combined SIR 1.21, 1.03-1.41).

A retrospective comparative study of mortality and causes of death among patients with metal-on-metal and metal-on-polyethylene total hip prostheses in primary osteoarthritis after a long-term follow-up

BackgroundAll patients with total hip arthroplasty (THA), especially those with metal-on-metal (MM) THA, are exposed to metallic particles and ions, which may cause total or site-specific mortality. We analyzed the causes of total and site-specific mortality among a cohort of patients with MM and with metal-on-polyethylene (MP) THA after a long follow-up time.MethodsStandardized mortality ratios (SMR) of total and site-specific causes of death were calculated for 579 patients with MM (McKee-Farrar) and 1585 patients with MP (Brunswik, Lubinus) THA for primary osteoarthritis.ResultsMean follow-up time was 17.9 years for patients with MM and 16.7 years for patients with MP. Overall SMR was 0.95 for the MM cohort and 0.90 for the MP cohort, as compared to the normal population. Both cohorts showed significantly decreased mortality for the first decade postoperatively, equal mortality over the next 10 years, and significantly increased mortality after 20 years. Patients with MM THA had higher cancer mortality (SMR 1.01) than those with MP THA (SMR 0.66) during the first 20 years postoperatively, but not thereafter.ConclusionBoth MM and MP prostheses are safe based on total and site-specific mortality of recipients during the first 20 postoperative years in comparison with the general population.

Decreased cancer risk in patients who have been operated on with total hip and knee arthroplasty for primary osteoarthrosis

3 Nordic cohorts of total hip (THA) and total knee arthroplasty (TKA) in patients operated on for primary osteoarthrosis during 1967–1995 were partly adapted and combined for meta-analysis. THA was performed in 49,000 patients and TKA in 24,000 totaling 497,000 person years. The mean and maximum follow-up times were 6.8 and 30 years, respectively. Standardized incidence ratios (SIRs) with 95% confidence intervals (95% CI) were calculated for the observed and expected number of cancers. The expected numbers were based on national incidence rates. The overall SIRs as well as the site-specific ones were similar in the THA and TKA patients. The observed number of cancers at all sites was 7,639 and the expected one was 8,202 (SIR 0.93,95% CI 0.91–0.95). The SIRs for lung cancer (0.69, 0.64–0.75) and laryngeal cancer (0.64, 0.44–0.92) were reduced. The incidence was also low for cancers of the stomach (SIR 0.76, 0.67–0.84), colon (SIR 0.86, 0.79–0.93) and rectum (SIR 0.89, 0.80–0.98). Among TKA patients, the only increases in SIRs were seen in cancers of the endometrium (SIR 1.36, 1.05–1.74), prostate (SIR 1.19, 1.02–1.38) and, among both THA and TKA patients, in skin melanoma (combined SIR 1.21,1.03–1.41).