DOES TOTAL KNEE REPLACEMENT MODIFY FLEXION AXIS OF THE KNEE ON FRONTAL AND AXIAL PLANE REGARDLESS FROM LIMB ALIGNMENT?

The optimal reference for rotational positioning of femoral component in total knee replacement (TKR) is debated. Navigation has been suggested for intra-op acquisition of patient’s specific kinematics and functional flexion axis (FFA). The main purpose of the present study is to prospectively investigate whether pre-operative FFA in patients with osteoarthritis (OA) and varus alignment changes after TKR and whether a correlation exists between post-op FFA and pre-op alignment. A navigated TKR was performed in 108 patients using a specific software to acquire passive joint kinematics before and after TKR. The knee was cycled through three passive range of motions (PROM), from 0° to 120°. FFA was computed using the mean helical axis algorithm. The angle between FFA and surgical TEA was determined on frontal (αf) and axial (αa) plane. The pre- and post-op hip-knee-ankle angle (HKA) was determined. Post-op FFA was different from pre-op FFA only on frontal plane. No significant difference was found on axial plane. No correlation was found between HKA-pre and αA-pre. A significant correlation was found between HKA-pre and αF–pre. The study concluded that TKR modifies FFA only on frontal plane. No difference was found on axial plane. Pre-op FFA is in a more varus position respect to TEA. The position of FFA on frontal plane is dependent on limb alignment. The present study has demonstrated TKR modifies the position of FFA only on frontal plane. The position of FFA on axial plane is not dependent on the amount of varus deformity and is not influenced by TKR. Level of evidence, IV, case series.

Does total knee arthroplasty modify flexion axis of the knee?

PURPOSE: To prospectively investigate whether preoperative functional flexion axis in patients with osteoarthritis- and varus-alignment changes after total knee arthroplasty and whether a correlation exists both between preoperative functional flexion axis and native limb deformity. METHODS: A navigated total knee arthroplasty was performed in 108 patients using a specific software to acquire passive joint kinematics before and after implant positioning. The knee was cycled through three passive range of motions, from 0° to 120°. Functional flexion axis was computed using the mean helical axis algorithm. The angle between the functional flexion axis and the surgical transepicondylar axis was determined on frontal (α (F)) and axial (α (A)) plane. The pre- and postoperative hip-knee-ankle angle, related to femur mechanical axis, was determined. RESULTS: Postoperative functional flexion axis was different from preoperative only on frontal plane, while no differences were found on axial plane. No correlation was found between preoperative α (A) and native limb deformity, while a poor correlation was found in frontal plane, between α (F) and preoperative hip-knee-ankle angle. CONCLUSIONS: Total knee arthroplasty affects functional flexion axis only on frontal plane while has no effect on axial plane. Preoperative functional flexion axis is in a more varus position respect to the transepicondylar axis both in pre- and postoperative conditions. Moreover, the position of the functional axis on frontal plane in preoperative conditions is dependent on native limb alignment, while on axial plane is not dependent on the amount of preoperative varus deformity.

The adductor tubercle as an important landmark to determine the joint line level in total knee arthroplasty: from radiographs to surgical theatre.

PURPOSE: The restoration of the normal joint line (JL) is important both in primary and revision total knee arthroplasty (TKA). However, the assessment of the femoro-tibial JL is still controversial. A strong correlation between femoral width (FW) and distance from adductor tubercle (AT) to JL was found on radiographs, with a ratio of 0.54. The hypothesis was that this ratio was applicable also in the surgical theatre by using measurements obtained intra-operatively with a caliper. METHODS: Femoral width, AT to JL distance and the RATIO between AT to JL distance and FW of 40 patients who underwent TKA were measured on radiograph and intra-operatively. Bland-Altman agreement tests with repeated measurements and linear regression analysis were used. The ratio was used to estimate the distance between JL and AT. RESULTS: The AT to JL distance/FW ratio calculated with linear regression resulted 0.54 for radiographic measurements and 0.53 for intra-operative measurements. There was no difference (0.009 ± 0.03) between the calculated ratios on radiographic and intra-operative measurements, and the correlation between intra-operative and radiographic measurements was 0.5 (p = 0.0016). CONCLUSIONS: This study shows that the validity of the radiographic method which uses an AT to JL distance/FW ratio to determine the level of the JL is confirmed also when using intra-operatively acquired measurements. Thus, this ratio represents a reliable tool to determine the JL level even in challenging prosthetic revision cases when the anatomical JL is missing. LEVEL OF EVIDENCE: Case series, Level IV.

Does chronic medial collateral ligament laxity influence the outcome of anterior cruciate ligament reconstruction?: a prospective evaluation with a minimum three-year follow-up.

We have shown in a previous study that patients with combined lesions of the anterior cruciate (ACL) and medial collateral ligaments (MCL) had similar anteroposterior (AP) but greater valgus laxity at 30° after reconstruction of the ACL when compared with patients who had undergone reconstruction of an isolated ACL injury. The present study investigated the same cohort of patients after a minimum of three years to evaluate whether the residual valgus laxity led to a poorer clinical outcome. Each patient had undergone an arthroscopic double-bundle ACL reconstruction using a semitendinosus-gracilis graft. In the combined ACL/MCL injury group, the grade II medial collateral ligament injury was not treated. At follow-up, AP laxity was measured using a KT-2000 arthrometer, while valgus laxity was evaluated with Telos valgus stress radiographs and compared with the uninjured knee. We evaluated clinical outcome scores, muscle girth and time to return to activities for the two groups. Valgus stress radiographs showed statistically significant greater mean medial joint opening in the reconstructed compared with the uninjured knees (1.7 mm (SD 0.9) versus 0.9 mm (SD 0.7), respectively, p = 0.013), while no statistically significant difference was found between the AP laxity and the other clinical parameters. Our results show that the residual valgus laxity does not affect AP laxity significantly at a minimum follow up of three years, suggesting that no additional surgical procedure is needed for the medial collateral ligament in combined lesions.

ST/G ACL reconstruction: double strand plus extra-articular sling vs double bundle, randomized study at 3-year follow-up.

Several investigators have reported the presence of biomechanical, kinematic, anatomic, fiber orientation patterns and biological differences between the anteromedial bundle and the posterolateral bundle of ACL. The purpose of this prospective randomized study was to compare the clinical, instrumental and X-ray outcome of two ACL reconstruction techniques with hamstring tendons: one with a single intra-articular bundle associated to an extra-articular sling, the second with a more anatomic double-bundle technique that reproduces better the native ACL function. From an initial group of 100 patients who underwent ACL reconstruction, 72 patients (35 single bundle plus lateral plasty and 37 double bundle) were evaluated with IKDC, Tegner score, KT2000 arthrometer, Activity Rating Scale, Psychovitality Questionnaire and Ahlback radiographic score at a mean 3 years follow-up. Double-bundle group showed significantly better results regarding IKDC, ROM, Activity Rating Scale and time to return to sport. Also KT 2000 showed significant differences in objective stability. The double-bundle technique for ACL reconstruction described in this paper has demonstrated significantly better subjective, objective and functional results compared with a double-stranded hamstrings plus extra-articular sling at a minimum 3-year follow-up.

Bone ultrasonography in glucocorticoid-induced osteoporosis.

Osteoporosis is one of the major complications of glucocorticoid (GC) therapy. Few data are available on the usefulness of quantitative ultrasound (QUS), a technique that could also theoretically provide information on bone structure, in the management of glucocorticoid-induced osteoporosis (GIO). This study aimed (1) to evaluate the ability of QUS in detecting bone impairment and in being associated with the prevalence of fragility fracture in GC patients; and (2) to assess whether QUS parameters, and particularly the graphic trace analysis of QUS signal at phalanges, show any peculiar pattern of GIO. We studied 192 patients (136 women and 56 men, mean age 56.7 +/- 14.2 years) on treatment with GCs for at least 6 months, and 192 sex- and age-matched controls. In all subjects, we measured bone mineral density (BMD) at lumbar spine and at femur by DXA, and ultrasound parameters at calcaneus and phalanges. All DXA and QUS parameters were significantly lower in GC patients than in controls and in fracture than in nonfracture GC patients. BMD at lumbar spine showed the best ability in discriminating GC patients with or without fractures. Among QUS parameters, stiffness showed a discriminatory ability significantly better than AD-SoS. BMD at lumbar spine and total femur, stiffness, and AD-SoS are able to predict the odds of fragility fracture event. QUS parameters of the postmenopausal GC patients (n = 105) and of the postmenopausal healthy controls (n = 101) were also compared with those obtained in a separate sample of 90 postmenopausal osteoporotic women (PMO). All parameters were significantly lower in GC patients and in PMO than in controls, without any significant difference between GC and PMO. Our findings show that QUS can be useful in the assessment of glucocorticoid-induced bone impairment. In addition, in this study we found no alteration in QUS parameters or in the graphic trace analysis which could differentiate between GIO and PMO. Further longitudinal studies are needed to define the role of QUS in the prediction of fracture risk and in the clinical management of GIO.

Alendronate treatment in men with primary osteoporosis: a three-year longitudinal study.

Bisphosphonates have been widely used in the treatment of osteoporosis in women, whereas until now there have been few data on their use in men. The aim of this study was to evaluate the effect of a 3-year alendronate treatment on bone mineral density (BMD) and quantitative ultrasound (QUS) in men with primary osteoporosis. We studied 77 osteoporotic men (aged 57.1 +/- 10.8 yrs) who completed a 3-year treatment with alendronate (10 mg/day) plus calcium (1000 mg/day) (n = 39), or calcium alone (n = 38). At baseline and at a 12-month interval, we measured BMD at the lumbar spine and femur (femoral neck and total hip) by DXA (Hologic) and speed of sound (SOS), broadband ultrasound attenuation (BUA) and Stiffness (S) at the os calcis by Achilles plus (Lunar). Alendronate treatment had significantly increased lumbar spine BMD by 4.2% at year 1, by 6.3% at year 2, and 8.8% at year 3. BMD at the femoral neck and total hip had increased by 2.1% and 1.6% at year 1, by 3.2% and 2.9% at year 2, and by 4.2% and 3.9% at year 3, respectively. BUA and Stiffness showed a significant increase in the alendronate-treated group at year 2 (3.2% and 4.9%, respectively) and at year 3 (3.8% and 6%, respectively). BMD at the lumbar spine showed the best longitudinal sensitivity whereas longitudinal sensitivity of both QUS at the heel and femur BMD were similar. In conclusion, this study confirms that alendronate represents an important therapeutic advance in the management of male osteoporosis. BMD at the lumbar spine appears to be the best method for monitoring the effect of alendronate on bone mass in osteoporotic men.

Graphic trace analysis of ultrasound at the phalanges may differentiate between subjects with primary hyperparathyroidism and with osteoporosis: a pilot study.

Bone loss characterizes both primary hyperparathyroidism (PHPT) and osteoporosis (OP) but with a different histologic pattern, and this could partially explain the different fracture incidence in these two populations. Quantitative ultrasound (QUS), influenced by bone structural parameters other than bone mineral density (BMD), could evidence these differences, opening new perspectives in the evaluation of patients with metabolic bone diseases. The aim of the present study was to investigate the usefulness of QUS graphic trace parameters, assessed at the phalanx, in discriminating between PHPT bone disease and osteoporosis. We studied 34 patients with PHPT (mean age 59.7 +/- 12.7 years), 35 patients with OP (mean age 60.6 +/- 7.1 years) and 34 healthy subjects as controls (mean age 59.1+/- 9.4 years). In all subjects QUS measurements were performed at the phalanx with a Bone Profiler (IGEA, Italy), obtaining the amplitude-dependent speed of sound (AD-SoS), fast wave amplitude (FWA), signal dynamic (SDy), bone transmission time (BTT) and ultrasound bone profile index (UBPI). Moreover, serum calcium, phosphorus, parathyroid hormone (PTH), bone isoenzyme of alkaline phosphatase (B-ALP) and ionized calcium were measured in all subjects in the morning under fasting conditions. In PHPT patients BTT was correlated with PTH, ionized calcium and B-ALP levels (r = -0.47, -0.57 and -0.44, respectively; p < 0.01), whereas FWA, SDy and UBPI correlated only with B-ALP (r = -0.43, -0.46 and -0.50, respectively; p <0.01). Moreover, FWA, SDY and UBPI were significantly (p<0.01) lower and BTT significantly (p<0.001) higher in OP than in PHPT patients. UBPI, BTT, FWA and the BTT/FWA ratio, but not SDy, were able to discriminate between the two groups (area under the curve =0.66, 0.69, 0.67 and 0.81, respectively). Our findings show that ultrasound signal parameters are differently influenced by bone changes characterizing primary hyperparathyroidism or osteoporosis. This suggests that the QUS signal could be a useful instrument in discriminating and studying some of the bone alterations typical of metabolic bone diseases.

Cholecystoenteric fistula (CF) is not a contraindication for laparoscopic surgery.

BACKGROUND: Cholecystoenteric fistula (CF) is a rare complication of cholelithiasis. The aim of this study was to evaluate the safety and risk of complications when the laparoscopic approach is applied in patients with CF. METHODS: A questionnaire was mailed to all surgeons with experience of >100 cholecystectomies working in Naples, Italy, and the neighboring area. RESULTS: Between February 1990 and May 1999, 34 patients presented with cholecystoenteric fistula (0.2% of >15,000 laparoscopic cholecystectomies performed in the same period). These patients were allocated into two groups: the LT group (those who underwent laparotomic conversion after the diagnosis of CF), which consisted of 20 patients, four men and 16 women, with a mean age of 66.5 +/- 9.3 years (range, 46-85) and the LS group (laparoscopically treated patients), which consisted of 14 patients, three men and 11 women, with a mean age of 65.6 +/- 8.8 years (range, 51-74). They types of CF observed were as follows: in the former group of patients, cholecystoduodenal fistulas (n = 11, 55%), cholecystocolic fistulas (n = 5, 25%), cholecystojejunal fistulas (n = 3, 15%), and cholecystogastric fistulas (n = 1, 5%); in the latter group, cholecystoduodenal fistulas (n = 8, 5.1%), and cholecystocolic fistulas (n = 4, 28.6) and cholecystojejunal fistulas (n = 2, 14.3%). Stapler closure of CF was done in four LT patients and three LS patients with cholecystoduodenal fistula; it was also done in three LT patients and three LS patients with cholecystocolic fistula. Hand-sutured fistulectomy was performed in six LT patients and three LS patients with cholecystoduodenal fistula, in two LT patients with cholecystocolic fistula, and in all patients with cholecystojejunal or cholecystogastric fistula. There were no deaths or intraoperative complications in either group. One patient in the LT group developed a bronchopneumonia postoperatively. Postoperative hospital stay was significantly longer in LT patients-17 +/- 4 vs 3+/-1 days (p < 0.001). CONCLUSION: Cholecystoenteric fistula is an occasional intraoperative finding during laparoscopic cholecystectomy. The results of this study, which are based on the collective experiences of 19 surgeons, illustrate the growing success of the laparoscopic approach to this condition, including a decreasing rate of conversion to open surgery over the last 3 years.

Dual X-ray absorptiometry and bone ultrasonography in patients with Rett syndrome.

This study evaluated bone status and bone turnover in 82 females (ages 2-21 years) with the Rett Syndrome (RS) and 82 age-matched controls. Bone mineral density (BMD) by dual X-ray absorptiometry (DXA) at the ultradistal and proximal radius and ultrasonographic (QUS) parameters at the calcaneus [speed of sound(SOS), broadband ultrasound attenuation(BUA), and stiffness] and at the phalanxes (amplitude dependent speed of sound: AD-SOS) were measured. We also measured serum calcium, phosphate, 25-hydroxyvitamin D, and biochemical markers of bone turnover. DXA and QUS parameters were significantly lower in patients with RS compared with controls and, among RS alone, in those treated with anticonvulsants and in those who are nonambulatory. Ambulatory RS patients showed QUS and DXA parameters significantly greater than nonambulatory patients but significantly lower than controls. Patients with RS treated with anticonvulsants presented QUS and DXA parameters lower than those of other RS. In RS patients, walking significantly influences BMD-UD, BMD-P, SOS. BUA. and Stiffness. Serum 25-hydroxyvitamin D was significantly lower in RS than in controls. These results suggest that ambulatory status, to a major extent, and anticonvulsant therapy certainly play an important role in the reduction of bone mass and bone quality, but they cannot completely explain the altered bone status. Whatever the cause, girls with RS present abnormal bone status with an increase in the risk of fracture.

Quantitative ultrasound at the phalanges in healthy Italian men.

In the last decade there has been a growing interest in quantitative ultrasound (QUS) techniques as a new method in the assessment of bone status in metabolic bone diseases. Many studies have shown that QUS parameters can predict vertebral and femoral fracture risk in patients with osteoporosis. However, most of the studies were performed in women, whereas few data are available for men. The aim of this study was to build up a normative database on a healthy Italian male population for QUS parameters at the phalanges. Amplitude-dependent speed of sound (AD-SoS) and three parameters (first wave amplitude, FWA; signal dynamic, SDy; time frame, TF) characterizing the graphic trace of the ultrasound signal were measured at the phalanges in 286 healthy subjects (age range 20-87 years). First, the QUS device was adapted to compensate for the difference in finger thickness between men and women. Preliminary data on 150 healthy subjects showed a significant difference between the traditional and adapted device, and the latter was independent of finger thickness variations. AD-SoS showed a significant (p<0.001) decrease with aging, expressed by a second-order polynomial equation. The peak value (2122 m/s) was observed in the fourth decade; thereafter it decreased to 1980 m/s at the ninth decade. Likewise, FWA and SDy were significantly (p<0.001) reduced after the fourth decade, whereas TF remained stable over time until the last decade. In conclusion, in men AD-SoS showed a negative trend with aging. The pattern with aging of parameters characterizing the graphic trace was different from the pattern for AD-SoS, suggesting the possibility of obtaining further information on phalanx bone physical properties which could be useful in the differential diagnosis of metabolic bone diseases and in the assessment of fracture risk.

Laparoscopic antegrade biliary stenting for postoperative endoscopic clearance of biliary stones.

Unsuspected ductal stones discovered during laparoscopic cholecystectomy may necessitate conversion to an open procedure, laparoscopic extraction, or postoperative endoscopic papillotomy. In order not to lose the advantages of a minimally invasive treatment and to decrease the likelihood of postoperative endoscopic failure, laparoscopic antegrade biliary stenting was attempted in 10 unselected patients (8 women, 2 men; mean age 52 +/- 11.4 years) with intraoperatively detected common bile duct stones. The mean diameter of these stones was 7 mm (range 5-11 mm). One stenting failed because of stone impaction, but the procedure was successful with effective biliary drainage in nine patients. The mean operative time was 70 (range 50-165) minutes. Subsequent ERCP was performed a mean of 8 (range 6-20) days after surgery. Deep cannulation, stent-guided papillotomy, and duct clearance was achieved in all stented patients, without any complication. Laparoscopic antegrade biliary stenting provides a guide for subsequent endoscopic stone removal, minimizing the risks of either stent migration or endoscopic failure. This combined technique is safe and cost effective and may be considered when ductal stones are discovered unexpectedly during laparoscopic cholecystectomy.

Osteogenesis imperfecta: bone turnover, bone density, and ultrasound parameters.

We studied 21 patients (11 men and 10 women) with osteogenesis imperfecta (OI) and 21 age- and sex-matched controls. In all patients we measured serum levels of total alkaline phosphatase (ALP), type I procollagen carboxy-terminal propeptide (PICP), osteocalcin (BGP), urinary excretion of hydroxyproline (HOP/Cr), and pyridinoline crosslinks (Pyr/Cr). Bone mineral density was measured at the distal radius (BMD-R) and at the lumbar spine (BMD-LS) by dual X-ray absorptiometry (DXA). Ultrasound parameters were also performed at the calcaneous with the Achilles device and at the phalanxes with DBM Sonic 1200. A significant reduction (P < 0.001) in BMD and in ultrasound parameters was found in OI patients compared with normals. PICP was significantly reduced in the OI patients compared with controls (P < 0.001); other markers of bone turnover were higher in OI than in controls, but the difference did not reach the statistical significance. A significant correlation (P < 0.05) was found between PICP and BMD at the lumbar spine and between PICP and ultrasound parameters at the calcaneous. On the basis of our data, we conclude that patients with OI show low values of BMD and ultrasound parameters; therefore in these patients, not only is bone mass disturbed but also bone quality. The reduced levels of PICP in OI patients confirm that most OI patients have defects in collagen I biosynthesis. These defects may contribute to the fragility of OI bone by interfering with complete mineralization and/or normal tissue structure. PICP may be considered a useful marker in the clinical management of OI.

Atovaquone is effective treatment for the symptoms of gastrointestinal microsporidiosis in HIV-1-infected patients.

OBJECTIVE: To report the clinical response to atovaquone in HIV-1-infected patients with symptomatic intestinal microsporidiosis. DESIGN: A retrospective review of a cohort of AIDS patients with symptomatic intestinal microsporidiosis who received atovaquone. SETTING: Infectious Disease Program of the Grady Memorial Hospital, Veterans Affairs Medical Center and private physicians' offices in Atlanta, Georgia. PATIENTS AND METHODS: HIV-1-infected patients (n = 371) were offered a complete stool evaluation and monthly follow-up. Among them, 22 were diagnosed with intestinal microsporidial infection using stool smears stained with modified trichrome stain. Species confirmation was made by light microscopy or electron microscopy on small intestinal biopsy specimens in some patients. MAIN OUTCOME MEASURE: Differences in symptoms, number of stools, and body weight were compared before and after a minimum of 1 month of atovaquone therapy. RESULTS: Eight patients received atovaquone treatment. The mean onset of clinical improvement after beginning treatment was 13 days (SEM, +/- 2). The mean number of stools per day decreased from 10 +/- 2.5 to 2 +/- 1 (P = 0.02, paired t test). The mean weight gain was 3 +/- 2 kg. The parasite was continuously present in the repeated stool specimens. However, semiquantitative analysis performed on two patients' stool specimens showed a decreased parasite burden. Four patients underwent small intestinal endoscopy was consistent with Enterocytozoon bieneusi in all four patients. Only one out of these four patients demonstrated a decrease in parasite burden in the biopsy specimen. Ultrastructural analysis performed in another of these four patients following treatment demonstrated the presence of electron-dense granules in spores, suggestive of toxic effects. CONCLUSION: Atovaquone demonstrates promise as a symptomatic treatment for intestinal microsporidiosis. A double-blind and placebo-controlled clinical trial is currently in progress.

Respiratory metabolism of the soft tick, Ornithodoros turicata (Dugès).

The rate of oxygen consumption was investigated in fed larval, nymphal and adult Ornithodoros turicata ticks and in starved nymphal and adult ticks. Oxygen consumption rate of fed adult ticks increased with increasing temperature. The metabolic rate of adult ticks was affected by starvation whereby starved adult ticks showed a significantly lower oxygen consumption than their fed counterparts. The oxygen consumption rate of fed female ticks was significantly higher than that of fed males but, there was no significant difference between the oxygen consumption rates of starved female versus starved male ticks. Oxygen consumption of fed larvae was significantly greater than those of fed first through third instar nymphs. Fed and starved nymphal ticks as well as fed adult ticks ventilated continuously. In contrast, starved adults ventilated discontinuously. The ability to reduce metabolic rate, plus the capability to ventilate discontinuously allow O. turicata adults to cope with prolonged starvation.

[Visceral leishmaniasis (kala-azar) and HIV infection. Apropos of a case and literature review]. / Leishmaniose viscérale (kala-azar) et infection HIV. A propos d'un cas et revue de la littérature.

A 42 year old male Spanish patient who presented since one year a symptomatic stage IV C1,C2,D HIV infection (Pneumocystis carinii pneumonia, cerebral toxoplasmosis, esophageal candidiasis, Kaposi's sarcoma) became progressively asthenic with weight loss, diarrhea, fever and complained about bone pain. These symptoms could be attributed to visceral leishmaniasis. This novel opportunistic infection should be considered in the differential diagnosis of fever of unknown origin in HIV+ patients coming from or having travelled in endemic areas.