Short-term complications in intra- and extra-articular anterior cruciate ligament reconstruction. Comparison with the literature on isolated intra-articular reconstruction. A multicenter study by the French Arthroscopy Society.

INTRODUCTION: Lateral tenodesis (LT) is performed to limit the risk of iterative tear following anterior cruciate ligament (ACL) reconstruction in at-risk patients. By adding an extra procedure to isolated ACL graft, LT reconstruction increases operating time and may complicate postoperative course. The objective of the present study was to evaluate the rate of early complications. The study hypothesis was that associating ALL reconstruction to ACL reconstruction does not increase the complications rate found with isolated ACL reconstruction. MATERIAL AND METHODS: A prospective multicenter study included 392 patients: 70% male; mean age, 29.9 years; treated by associated ACL and LT reconstruction. All adverse events were inventoried. RESULTS: Mean hospital stay was 2 days, with 46% day-surgery. Walking was resumed at a mean 27 days, with an advantage for patients treated by the hamstring technique. The early postoperative complications rate was 12%, with 1.7% specifically implicating LT reconstruction: pain, hematoma, stiffness in flexion and extension, and infection. There was a 5% rate of surgical revision during the first year, predominantly comprising arthrolysis for extension deficit. The 1-year recurrence rate was 2.8%. DISCUSSION: The complications rate for combined intra- and extra-articular reconstruction was no higher than for isolated intra-articular ACL reconstruction, with no increase in infection or stiffness rates. The rate of complications specific to ALL reconstruction was low, at 1.7%, and mainly involved fixation error causing lateral soft-tissue impingement. LEVEL OF EVIDENCE: IV, prospective multicenter study.

Midterm results of combined intra- and extra-articular ACL reconstruction compared to historical ACL reconstruction data. Multicenter study of the French Arthroscopy Society.

INTRODUCTION: During anterior cruciate ligament (ACL) reconstruction procedures, anterolateral reconstruction (ALR) can also be performed to improve the knee's rotational stability. However, the effectiveness of this supplemental technique and its impact on the risk of retears and on the onset of secondary degenerative changesare controversial. HYPOTHESIS: ALR improves control over the pivot shift, reduces the retear risk and delays the appearance of secondary degenerative lesions. MATERIAL AND METHODS: Clinical examination, knee laxity measurements and X-ray evaluations were done in 478 patients with more than 3years' follow-up after combined ACL and ALR from 11 participating hospitals. The mean patient age at the time of surgery was 28years. Eighty-eight percent of the patients participated in pivot sports and 45% were competitive athletes. The findings of this study were compared to historical isolated ACL reconstruction data. RESULTS: The average follow-up was 6.8years. No detectable pivot shift was found in 83% of patients, while 12.8% of patient had a smooth glide. The side-to-side difference in anteroposterior knee laxity with maximum manual force was less than 3mm in 66% of patients and less than 5mm in 95%. The retear rate was 5.4%, with half of these patients undergoing revision ACL surgery. Secondary meniscus damage requiring surgery occurred in 6.3% of patients; the radiological osteoarthritis rate was 17.5%. DISCUSSION: When compared to historical ACL reconstruction data, combined intra- and extra-articular reconstruction does not increase the complication rate. At a mean follow-up of 6.8years, it provides better control over the pivot shift along with a low retear rate and low occurrence of secondary meniscus injuries. LEVEL OF EVIDENCE: IV, multicenter study.

Combined intra- and extra-articular grafting for revision ACL reconstruction: A multicentre study by the French Arthroscopy Society (SFA).

BACKGROUND: A careful analysis of the reasons for ACL reconstruction failure is essential to selection of the optimal surgical revision technique designed to ensure good rotational stability and to minimise the risk of re-rupture. OBJECTIVE: To evaluate anterolateral ligament (ALL) stabilisation during revision ACL reconstruction. HYPOTHESIS: ALL stabilisation during revision ACL reconstruction provides good rotational stability without increasing the risk of complications. MATERIAL AND METHODS: This multicentre study included 349 patients, 151 retrospectively and 198 prospectively. There were 283 males and 66 females. Inclusion criteria were an indication for revision ACL reconstruction surgery with combined intra-articular reconstruction and ALL stabilisation after failed autograft ACL reconstruction, and intact PCL. Exclusion criteria were primary ACL reconstruction and concomitant peripheral medial and/or lateral lesions. Each patient underwent a clinical and radiographic evaluation before and after revision surgery. Before revision surgery, the mean IKDC score was 56.5±15.5 and 96% of patients were IKDC C or D. RESULTS: Rates were 5.0% for early and 10.5% for late postoperative complications. Lachmann's test had a hard stop at last follow-up in 97% of patients. The pivot-shift test was positive in 1% of patients. The mean subjective IKDC score was 84.5±13.0 and 86.5% of patients were IKDC A or B. The proportions of patients with radiographic knee osteoarthritis at last follow-up was unchanged for the lateral tibio-femoral and patello-femoral compartments but increased by 9.7% to 21.2% for the medial tibio-femoral compartment. The re-rupture rate was 1.2% and the further surgical revision rate was 5.4%. CONCLUSION: Anterior laxity at last follow-up was consistent with previous studies of revision ACL reconstruction. However, rotational stability and the re-rupture risk were improved. ALL stabilisation is among the techniques that deserve consideration as part of the therapeutic options for revision ACL reconstruction. LEVEL OF EVIDENCE: IV, retrospective and prospective cohort study.

Natural history of partial anterior cruciate ligament tears: a systematic literature review.

INTRODUCTION: Partial anterior cruciate ligament (ACL) tear is frequent, and indications for surgery may be raised by a diagnostic aspect associating slight laxity with no clear pivot-shift. Unlike that of complete ACL tear, the natural history of partial tear remains controversial. MATERIAL AND METHOD: A systematic literature review searched for referenced publications on the natural history of partial ACL tear. Twelve specific articles were retrieved. Initial diagnosis was systematically confirmed on arthroscopy, without ACL surgery. The following criteria were analyzed: firstly, preoperative: confirmation of inclusion criteria, preoperative clinical data, follow-up, arthroscopic lesion assessment, Lachman test, Pivot shift test, hemarthrosis, associated lesions and secondly, follow-up: Lachman test, Pivot shift test, revision surgery, functional clinical scores, pain, sport and return to sport, meniscal events. RESULTS: Preoperatively, Lachman tests were positive (soft or delayed) in a mean 49.7% of cases (range, 0-100%); pivot shift test was systematically negative. At a mean 5.2 years' follow-up, Lachman test was "positive" in 47.6% of cases (range, 38-59%), with positive pivot shift test in 26.3% (range, 5-51%). 54.3% patients reported pain (range, 36-64%), and mean Lysholm score was 88.4 (17-100%). Fifty-two percent (21-60%) of patients resumed sport at their previous level. DISCUSSION/CONCLUSION: The natural history of non-operated partial ACL tear is good over the medium term, especially if patients limit their sports activities. The greater the functional instability, the more frequent is residual pain. Laxity, although not quantified, seems to progress with time, with a positive pivot shift test emerging in a quarter of cases. Functional management may be recommended in non-athletic patients without meniscal lesion, but surgical treatment may be recommended in other patients. Indications for ACL reconstruction are thus the same in partial as in complete tear.

Anterior cruciate ligament reconstruction in partial tear: selective anteromedial bundle reconstruction conserving the posterolateral remnant versus single-bundle anatomic ACL reconstruction: preliminary 1-year results of a prospective randomized study.

INTRODUCTION: Partial tears of the anterior cruciate ligament (ACL) are frequent. Conserving ACL remnants is central to the concept of anatomic, biomechanical and biological reconstruction. The interest of such conservation remains theoretical. The present hypothesis was that selective anteromedial (AM) bundle reconstruction is preferable to the standard single-bundle reconstruction in partial ACL tear. MATERIALS AND METHODS: A multicenter prospective randomized study recruited 54 partial ACL tears operated on either by selective AM bundle reconstruction (Group 1, n=29) or by standard anatomic single-bundle reconstruction (Group 2, n=25). All patients were clinically assessed on subjective and objective IKDC, Lysholm and KOOS scores, with a minimum 12 months' follow-up. Comparative pre- to postoperative anterior laxity was measured on the Rolimeter(®) device, with statistical analysis of results. RESULTS: There were no significant preoperative differences between the two groups. All patients were followed-up at 6 months and 1 year. Mean subjective IKDC scores for groups 1 and 2 respectively were 55.8 and 56.8 preoperatively versus 86.2 and 85.7 at 1 year; Lysholm scores were 69.9 and 71.1 versus 90.9 and 91.8. These inter-group differences were non-significant. Differential laxity for groups 1 and 2 respectively was 5.0mm (range, 2-10) and 5.1mm (2-12) preoperatively (P=0.73), versus 1.2mm and 1.9 mm postoperatively (P=0.03). DISCUSSION AND CONCLUSION: In partial ACL tear, selective AM bundle reconstruction conserving the posterolateral bundle remnant provides clinical results comparable to the standard single-bundle technique, with better control of anterior laxity. Longer follow-up, however, will be needed to compare evolution in anterior and rotational laxity and in subjective results over time.

Partial ACL reconstruction with preservation of the posterolateral bundle.

INTRODUCTION: Over the past decade, our understanding of the anterior cruciate ligament (ACL) has evolved considerably. Based on this knowledge, ACL reconstruction techniques have changed and selective reconstruction procedures have been developed for partial tears. Our hypothesis was that stability and function can be restored to the knee with selective bundle reconstruction of partial ACL tears and preservation of the residual fibers. MATERIALS AND METHODS: This was a multicenter retrospective study of 168 partial reconstructions of the anteromedial (AM) bundle of the ACL with preservation of the posterolateral (PL) bundle. All patients underwent a clinical evaluation based on the objective and subjective IKDC scores and the Lysholm score after a mean follow-up of 26 months (12-59 months). Preoperative and postoperative instrumental measurement of knee laxity was performed by arthrometer and/or by (Telos(®)) stress radiography. Statistical analysis and comparison was performed between pre- and postoperative results. RESULTS: The preoperative and postoperative subjective IKDC scores were 63.7 and 90.5 at the final follow-up respectively (P<0.001). The preoperative and postoperative Lysholm scores were 80 and 95.5 respectively (P<0.001). Preoperatively, most patients were classified C on the objective IKDC score. At the final follow-up 92% of the patients were classified A or B (P<0.001). Differential preoperative laxity was 5.5mm (range: 0-14 mm) and 1.1mm (range: 0-4mm) at the final follow-up (P<0.00001). DISCUSSION AND CONCLUSION: Our study confirms that selective reconstruction of the AM bundle of the ACL with preservation of the PL bundle restores stability and function to the knee. Special attention should be paid to the size of the graft used to avoid excess tissue in the intercondylar notch.

A comparison of Telos™ stress radiography versus Rolimeter™ in the diagnosis of different patterns of anterior cruciate ligament tears.

INTRODUCTION: Our knowledge on anterior cruciate ligament (ACL) pathomechanics has increased. The diagnosis of partial ACL tears must be accurate in order to adjust the operative planning to anatomic status and injury severity. Instrumented measurement of knee laxity is a useful preoperative tool to quantify anterior tibial translation and several laximetry tests are available. Yet, their accuracy remains to be established. HYPOTHESIS: Clinical examination combined to instrumented laximetry with Telos™ 15 kg and/or Rolimeter™ would increase their sensitivity and specificity in the diagnosis of various ACL injury patterns. MATERIALS AND METHODS: One hundred and seventy-seven patients were prospectively included. The ACL status was validated by arthroscopy. Around 69.5% had a complete ACL tear and 30.5% had a partial ACL tear. RESULTS: Gross laxity with positive clinical tests was associated with complete ACL tears. Mean side-to-side difference was significantly greater with both laximetry methods in complete versus partial ACL tears. Laximetry results among different types of partial tears were not significantly different. Telos™ results were consistent with gross laxity confirmed by pivot-shift test, while this was not recorded with Rolimeter™. Gross laxity with clinical tests and anterior tibial translation more than 5mm with Telos™ were substantially associated with complete ACL tears. DISCUSSION: The combination of standard clinical examination with Telos™ was more accurate than with Rolimeter™ in the preoperative identification of the ACL injury pattern. Applying additional diagnostic tools can help the surgeon to preoperatively diagnose partial or complete ACL ruptures and propose an injury-specific surgical treatment. LEVEL OF EVIDENCE: Level III (case-control study).

Current concept of partial anterior cruciate ligament ruptures.

A partial tear of the anterior cruciate ligament is a frequent pattern of ACL injury, observed in 10 to 27% of isolated ACL lesions. There are three reasons to preserve these remnants: biomechanical, vascular and proprioceptive advantages for the patient. Good quality fibers work as graft protection during the healing process. Periligamentous and endoligamentous vessels present into the native ACL tissue may enhance the vascularization of the ACL augmentation. Mechanoreceptors still remaining in the residual ACL fibers may have proprioceptive function. Definition is controversial, based on anatomy, on clinical examination, on instrumental laxity assessment or on MRI findings. Continuous remnant ACL fibers bridging the femur and tibia, from native femoral ACL footprint to native tibial ACL footprint seem to be a good definition. Diagnostic is suspected by accumulation of arguments brought by a thorough clinical examination, precise MRI analysis and examination under anesthesia. But the final diagnostic needs an arthroscopic evaluation to confirm the presence of fibers in good position and to validate its good mechanical properties. The treatment of ACL partial tear is a demanding surgery; difficulties to visualize the graft insertion site, especially on the femoral side, require a perfect knowledge of the normal anatomy of the native ACL footprint. Adapted portals, perfect controls of the tunnel drilling process, intercondylar notch space management are the keys of success. The pivot shift test under anesthesia, a hard stop Lachman test, MRI findings, level and type of sport, arthroscopic aspects of the remnants and its mechanical properties, allow the surgeon decide between non operative treatment, ACL augmentation or standard ACL reconstruction.

[The ACL tear from the pre-operative analysis to a 2-year follow-up, influence of the graft choice on the subjective and objective evaluation]. / La rupture du ligament croisé antérieur, de l'analyse préopératoire du type de rupture à l'évaluation finale à deux ans, retentissement selon le transplant choisi sur les résultats subjectifs et objectifs.

This study is a synthesis of three series. The first study was prospective on 418 patients with an anterior cruciate ligament (ACL) tear (group I). Two population of ACL ruptures were identified. One population with a postero-lateral bundle preserved in 16%, the mean medial anterior tibial translation side to side was 4.97 mm, the Lachman test was delayed in 40% with no or glide pivot shift in 73%. The second population with a complete ACL tear had a mean medial anterior tibial translation side to side of 7.93 mm, the Lachman test was soft in 98% with gross pivot shift in 80%. The second study was a retrospective study on 258 patients (group II) at 26 months follow-up, it correlated the impact of the type of graft on the clinical objective and subjective results. Twenty-eight percent had anterior knee pain, 33% for the patellar tendon and 25% for the hamstrings, the subjective IKDC was significantly lower for the painful knees, and 68% of the patellar tendon had a hypoesthesia and only 32% for the hamstrings. The ability to walk on the knee was 68% for the hamstrings and 35% for the patellar tendon. The third study was retrospective on 127 patients, 24 months after ACL reconstruction (group III), all were tested on a isokinetic machine for the extensor, the flexor and the internal rotator. In the total population, a 10% extensor and flexor deficit and a 5% rotator deficit was noted. A significant difference between patellar tendon and hamstrings in terms of muscular recovery was found. It pointed out that a more specific rehabilitation should be done on the hamstring group. The muscular recovery was correlated to the highest subjective score. This study allowed the surgeon to be more specific in the ACL tear definition, to adapt the graft choice to the type of sport activity but also to the type of work the patient does and finally to modify the rehabilitation protocol for the hamstring technique.

[Clinical, radiological and arthroscopic analysis of the ACL tear. A prospective study of 418 cases]. / Analyses clinique, radiologique et arthroscopique de la rupture du LCA. Etude prospective de 418 cas.

This prospective multicentric study concerns 418 anterior cruciate ligament tears. It correlates the arthroscopic data's and the clinical and radiological data's. Four types of anterior cruciate ligament tears were identified. Complete tears, postero lateral bundle preserved, healing on the posterior cruciate ligament and healing in the notch. The statistical correlations had shown a highest laxity in the complete tear group with a highest rate of soft Lachman and gross pivot shift, a highest incidence of medial meniscus tears was also noted and a longer delay between injury and surgery, 24 months for the complete tear group and seven months for the postero lateral bundle group. The mean medial compartment laxity, side to side, in the postero lateral bundle group was 4.93 mm and 7.93 mm in the complete tear group. These data could help the surgeon in his surgical planning especially in case of partial tears.

[The effect of the posterolateral bundle in the anterior cruciate ligament reconstruction]. / Le comportement du faisceau postérolatéral dans les reconstructions anatomiques du ligament croisé antérieur.

The use of new technology in 3D laxity analysis in torn anterior cruciate ligament (ACL) knee has recently improve the ability to assess the effect of reconstruction on laxity control. The aim of this study was to compare, in anatomic ACL reconstruction, the effect of each bundle, posterolateral (PL) and anteromedial (AM) on the residual laxity intraoperatively. We used an optoelectronic navigation system to measure the translation and the rotation during anterior drawer test, Lachman test and pivot shift test. Twenty-two patients were assessed with two protocols, group I with PL bundle reconstruction following the AM bundle reconstruction and group II with a reverse program. Addition of PL bundle has significantly improved the translation and rotation laxity control during the Lachman and pivot shift test, when the AM bundle was more important in the translation control during the anterior drawer test. Anatomic double bundle reconstruction improves the control of laxity intraoperatively.

Complications of Ilizarov leg lengthening: a comparative study between patients with leg length discrepancy and short stature.

The Ilizarov technique has been used to treat severe limb length discrepancy and short stature. However, complications of this treatment are frequent. Between 1984 and 2001, 57 patients (94 tibias) had an Ilizarov procedure for limb lengthening. Twenty patients had limb discrepancy and 37 had short stature. Their mean age was 20.2 years (range 15-34). The average limb lengthening was 8.37 cm (range 3.2-14.7), which was equivalent to 26% (range 9.2-60%) average tibial lengthening. A total of 90 complications were observed. Thirty-three unplanned procedures were required during the lengthening programme. Two patients stopped the lengthening programme. There was no difference in the complications in leg lengthening using Ilizarov technique between the group of patients with leg length discrepancy and the group with short stature. A good knowledge of the Ilizarov technique is necessary to perform a lengthening programme with a low rate of complications.

[Progressive limb lengthening with a centromedullary nail versus an external fixator: experimental study in sheep]. / L'allongement progressif des membres par clou mécanique centro-médullaire d'allongement: étude expérimentale chez le mouton.

PURPOSE OF THE STUDY: Progressive limb lengthening with an external fixator often leads to pin-related complications. A new technique allowing progressive lengthening with a centromedullary nail without external fixation has been developed. This original double-locked device consists of matching male and female components fitted with a continuous thread. Lengthening is achieved via a one-way ratchet system. Twelve back-and-forth movements produce 1.25 mm lengthening. MATERIAL AND METHODS: We tested this new device on 20 sheep and compared results with external fixation lengthening in 20 other sheep. The animals were divided into groups for sacrifice on days 5, 10, 20, 45 and 90. Serial x-ray were obtained for all animals. In the 45-day and 90-day groups, histomorphometric (trichrome goldner coloration and polarized light microscopy) and densitometric studies were also performed. Bone mineral density (BMD) was determined and bone trabecular density (BTD) and trabecular bone volume (TBV) were expressed in percent of bone trabecular surface area. RESULTS: Mean lengthening in the 45-day and 90-day groups was 39 mm for the nail and 20 mm for external fixation (1 mm/day). At 90 days, 3 sheep out of 4 had consolidated radiologically with external fixation and 2 out of 4 with the nail. BMD was slightly better for external fixation (0.811 vs 0.695/cm(2)). This difference could probably be attributed to the greater lengthening obtained with the nail. At 45 days, BMD was the same (0.6 g/cm(2)) for both devices. BTD was nearly two-fold higher for the nail compared with external fixation (59.65% vs 32.61% at 90 days), most probably due to primary bone formation. The histomorphometric study allowed an analysis of the osteoid border. Bone quality obtained in the bone regenerate with the nail was superior to that obtained with external fixation. Primary bone formation resulted from membrane ossification with direct transformation of fibroblasts into osteoblasts. CONCLUSION: This work demonstrated that progressive lengthening can be achieved with a specifically designed centromedullary nail without iterative opening of the operative site. Tolerance to this type of device and quality of the bone regenerate are altogether satisfactory.

Modulation of monoamine oxidase activity in different brain regions and platelets following exposure of rats to methylmercury.

Monoamine oxidase (MAO; EC 1.4.3.4) is known to have an important role in the regulation of biogenic amines in the brain and peripheral tissues. It is also known that circulating platelets represent an excellent model for an easy assessment of the effect of MAO-B inhibitors in extracerebral tissue. The present study was carried out to determine the effects of methylmercury (MeHg) on the activity of MAO in synaptosomes of different brain regions of male Sprague-Dawley rats as well as in rat blood platelets both in vitro and in vivo. MeHg pretreatment inhibited the activity of MAO in the synaptosomes of the cortex, hypothalamus, hippocampus, striatum, cerebellum, and brain stem in a concentration-dependent (0-10 microM) manner. The threshold concentration of MeHg for such inhibition in different brain synaptosomes was found to be the same (i.e., 1 microM) except for in the rat striatum it was 2.5 microM, and the IC50 value for MeHg was found to be around 2.1 microM. Significant inhibition of the MAO activity was also observed in synaptosomes of the cortex, cerebellum, hypothalamus, and hippocampus as well as in platelets of rats 24 h after treatment by gavage with a total cumulative dose of 35 mg/kg (5 mg/kg/day for 7 days). The decrease of such activity was found to be at maximum in different brain synaptosomes and platelets 24 h following treatment with a cumulative total dose of 75 mg/kg (7.5 mg/kg/day for 10 days); the treated animals showed signs of ataxia under these conditions. The data have further shown that methylmercury is capable of inhibiting the MAO activity in different brain synaptosomes to different degrees but without showing any specificity towards any specific brain region. The present in vivo results suggest that the platelet MAO activity may be used as a potential biomarker of early neurotoxicity due to repeated exposure to MeHg in rats.

Sensitivity of platelet microtubules to disassembly by methylmercury.

With the aim of identifying a surrogate marker for the neurotoxic effects of methylmercury using a peripheral blood sample, the sensitivity of microtubules in circulating blood cells to depolymerization by methylmercury was compared. Methylmercuric chloride was added to samples of human venous blood or to isolated platelets and lymphocytes (human or rabbit) suspended in RPMI medium plus 10% fetal calf serum. After 1 h, microtubular networks were visualized by immunolabeling with antibody specific for tubulin. The percentage of platelets without visible, intact microtubules and the percentage of viable, unactivated lymphocytes without microtubules visibly radiating from the centriolar region through the cytoplasm were counted. A concentration-dependent loss of microtubules was observed in both cell types. Loss of microtubules was more easily quantitated and was observed at significantly lower concentrations in platelets compared to lymphocytes. The IC50 (concentration of methylmercuric chloride resulting in dissolution of microtubules in 50% of the cells) was 3.1 microM in platelets and 7.4 microM in lymphocytes in samples exposed in culture medium without erythrocytes. When methylmercury was added to whole blood for 1 h, the IC50 increased to 182 microM in platelets and >700 microM in lymphocytes, consistent with the known sequestration of methylmercury in erythrocytes. With longer durations of exposure, much lower concentrations of methylmercury were effective in both cell types. When rabbit lymphocytes and platelets were exposed to methylmercury under culture conditions, IC50s in platelets/lymphocytes were 2.5 microM/4.8 microM after 1 h of exposure, 0.77 microM/1.12 microM after 20 h, and 0.51 microM/0.63 microM after 70 h. The results of this study suggest that platelets may be more suitable than lymphocytes as a cell type in which to monitor in vivo effects of methylmercury on microtubules.

[Effect of fibrin glue on lymphostasis during lymph node excisions. Prospective randomized study in 40 patients]. / Efficacité d'une colle de fibrine sur la lymphostase au cours des curages ganglionnaires. Etude prospective randomisée sur 40 patients.

To evaluate the efficacy of fibrin glue for lymphostasis during axillary and inguinal lymph node removal, we conducted a prospective randomized study including 40 patients. Post-operative mortality and morbidity rates were not different throughout the 2 groups. However they were significant decreasement in drainage duration, in drainage quantity and in hospital duration in the group "with" fibrin when compared with the group "without".

[Environmental factors in the etiology of Parkinson's disease]. / Facteurs environnementaux dans l'étiologie de la maladie de Parkinson.

We examined the role of the environment in the development of Parkinson's disease (PD). A group of 42 parkinsonians have been compared with a group of 84 matched controls. The epidemiological study (1987-1989) covered the territory of the Community Health Department of Valleyfield, in southern Quebec (Canada). Odds ratio adjusted for age and sex were calculated for seven environmental factors. A decreased risk for PD was associated with residence in rural areas (OR: 0.31; p less than or equal to 0.05) and residence near industry or mining (OR: 0.15; p less than or equal to 0.05). An increased risk for PD seems to be associated with occupational exposure to the three metals Mn, Fe and Al (OR: 2.28; p = 0.07) especially when the duration of exposure is longer than 30 years (OR: 13.64; p less than or equal to 0.05). Other environmental factors not found to be associated with PD were: pesticides manipulation, farm work, industrial work and well water consumption.