Humoral immune response to Aggregatibacter actinomycetemcomitans leukotoxin.

BACKGROUND AND OBJECTIVE: Periodontal disease is an inflammatory condition caused by bacterial infections that result in loss of the tooth supporting tissue. The periodontal pathogens produce virulence factors with capacity to affect the host immune response. Aggregatibacter actinomycetemcomitans is a periodontal pathogen that produces a leukotoxin that specifically affects human leukocytes. The aims of the present study were to examine the presence and function of systemic antibodies to the leukotoxin. MATERIAL AND METHODS: One hundred and ninety-seven middle-aged (57 ± 5 years) Swedes with well-documented periodontal status and medical factors related to cardiovascular diseases were studied. These data have been published previously. The serum samples were examined for the presence of leukotoxin antibodies by western blot and the capacity to neutralize leukotoxicity in an activity assay with leukotoxin and cultured leukemic cells. RESULTS: The results showed a high prevalence (57%) of antibodies against A. actinomycetemcomitans leukotoxin in the analyzed population. These antibodies were correlated with leukotoxin neutralizing capacity as well as with the ELISA titers of A. actinomycetemcomitans-specific IgA and IgG. In addition, high levels of leukotoxin antibodies were correlated with increasing age, but not with periodontal disease parameters or cardiovascular risk factors. CONCLUSION: Systemic antibodies against A. actionmycetemcomitans leukotoxin were common in this adult Swedish population. These antibodies might contribute to limit the systemic effects of the infection.

Different cysteine proteinases involved in bone resorption and osteoclast formation.

Cysteine proteinases, especially cathepsin K, play an important role in osteoclastic degradation of bone matrix proteins and the process can, consequently, be significantly inhibited by cysteine proteinase inhibitors. We have recently reported that cystatin C and other cysteine proteinase inhibitors also reduce osteoclast formation. However, it is not known which cysteine proteinase(s) are involved in osteoclast differentiation. In the present study, we compared the relative potencies of cystatins C and D as inhibitors of bone resorption in cultured mouse calvariae, osteoclastogenesis in mouse bone marrow cultures, and cathepsin K activity. Inhibition of cathepsin K activity was assessed by determining equilibrium constants for inhibitor complexes in fluorogenic substrate assays. The data demonstrate that whereas human cystatins C and D are equipotent as inhibitors of bone resorption, cystatin D is 10-fold less potent as an inhibitor of osteoclastogenesis and 200-fold less potent as an inhibitor of cathepsin K activity. A recombinant human cystatin C variant with Gly substitutions for residues Arg8, Leu9, Val10, and Trp106 did not inhibit bone resorption, had 1,000-fold decreased inhibitory effect on cathepsin K activity compared to wildtype cystatin C, but was equipotent with wildtype cystatin C as an inhibitor of osteoclastogenesis. It is concluded that (i) different cysteine proteinases are likely to be involved in bone resorption and osteoclast formation, (ii) cathepsin K may not be an exclusive target enzyme in any of the two systems, and (iii) the enzyme(s) involved in osteoclastogenesis might not be a typical papain-like cysteine proteinase.

An evaluation of the use of retrospectively acquired preoperative AOFAS clinical rating scores to assess surgical outcome after elective foot and ankle surgery.

The use of retrospectively acquired preoperative AOFAS rating scores in clinical research to assess the outcomes of elective foot and ankle surgery has not been validated. The data obtained utilizing this methodology may misrepresent the results and lead to spurious conclusions. This investigation compared preoperative AOFAS Ankle-Hindfoot scores obtained before and after surgery from patients who had undergone elective surgery to determine if retrospectively acquired scores match those collected prospectively. Only two out of 47 patients (4%) recalled identical AOFAS scores. The mean difference between the preoperative scores (preoperative score obtained after surgery minus preoperative score obtained before surgery) was -5.3 points. Fifteen patients (32%) had preoperative scores that differed by 20 points or more. Kappa statistics found little agreement among the five elements that comprised the two preoperative scores when responses obtained before and after surgery were compared to one another. The results suggest that preoperative clinical rating scores obtained after elective surgery are a poor predictor of the patient's preoperative condition and that studies which employ retrospectively acquired preoperative AOFAS clinical rating scores may overestimate the benefit of surgery.

Inpatient management of lower extremity amputations.

The in-hospital care of the amputee is crucial; careful preoperative, intraoperative, and postoperative regimens set the stage for a successful clinical outcome. Caring for the patient undergoing amputation is much more than choosing the correct level at which to cut. Early aggressive rehabilitation; careful attention to postoperative complications; and appropriate physical therapy, occupational therapy, and counseling all play pivotal roles. Thorough knowledge of these issues helps to increase the likelihood of a successful outcome and to keep morbidity to a minimum.

The effects of adult acquired flatfoot deformity on tibiotalar joint contact characteristics.

Changes in the tibiotalar contact characteristics were investigated using eight fresh frozen cadaver ankle specimens to further develop an established model of the acquired flatfoot deformity. The deformity was simulated by sectioning the tendons and ligaments of the ankle and foot that normally support the longitudinal arch. Axial loads of 1,350 N were applied to the foot in a neutral position in both the intact specimen and flatfoot model. The flatfoot condition resulted in significant lateral shifts of 5.28 mm in global contact area and 11.26 mm in the location of peak pressure, and in a small but significant posterior shift of 1.14 mm in global contact area. The flatfoot condition also resulted in a significant, 35%, reduction in contact area. Significant increases in mean pressure, 14%, and peak pressure, 13%, were also found, but were not in proportion to the relatively large decrease in contact area. This suggests a transfer of load off of the talar dome. Increased loading of the lateral facet and fibula are suspected. The lateral shift in the contact region created a local increase in mean contact pressure that may be responsible for long term degenerative changes in patients with this deformity.

Extended hindfoot fusions and pantalar fusions. History, biomechanics, and clinical results.

Contemporary techniques of hindfoot and ankle arthrodesis can result in a high rate of osseous union, pain relief, and patient satisfaction. Methods range from open approaches to fully arthroscopic surgical techniques. Arthrodesis should be limited to the joints involved with the arthritic, deforming, or neuromuscular process because the rate and severity of progressive adjacent joint degeneration appear related to the number of joints fused initially. Appropriate joint position, maintained with stable internal fixation applied in compression and augmented with bone-graft material when necessary, should be considered the gold standard for most hindfoot and ankle arthrodeses. External fixation may be used in the revision or salvage setting if needed or when soft tissues or bone stock do not permit stable internal fixation. Meticulous attention must be given to the handling of soft and hard tissues as well as to correction of the underlying deformity and to appropriate positioning of the joints in question. Newer techniques, such as intramedullary fixation, arthroscopic or arthroscopically assisted ankle arthrodesis, and total ankle arthroplasty, have shown some promise and warrant more extensive study.

Evans osteotomy in the adult foot: an anatomic study of structures at risk.

The Evans osteotomy has become an important option in the surgical treatment of adult pes planus deformity of multiple causes. Despite its increasing popularity, however, no single study, to our knowledge, has thoroughly examined the structures at risk when performing the Evans osteotomy on the adult foot. We performed the Evans osteotomy on 20 adult cadaver specimens to determine which soft tissues and bony structures were endangered by the procedure. We found that the optimal Evans osteotomy site should be exactly 10 mm proximal to the calcaneocuboid joint because this location best affords the opportunity of avoiding damage to the anterior or middle subtalar facets in those specimens with separate facets. In addition, we determined that the sural nerve, peroneus longus tendon, and peroneus brevis tendon were consistently at risk during the operative approach. Regarding the medial soft tissues, we found that these structures did, in fact, consistently pass in the line of the Evans osteotomy, and so are at risk.

Use of ultrasonography versus magnetic resonance imaging for tendon abnormalities around the ankle.

A prospective study was performed on 28 patients who underwent surgery for tendon disorders around the ankle. Preoperatively, all patients had real-time, high resolution ultrasonography performed with a 7.5 or 10 mHz transducer. Twenty of these patients also had a preoperative magnetic resonance imaging (MRI) examination of the ankle. A total of 54 tendons were inspected intraoperatively, revealing a total of 24 intrasubstance or complete tendon tears. These surgical findings were compared with the ultrasound and MRI findings, from which the sensitivity, specificity, and accuracy were calculated for both modalities. Ultrasound produced results with a sensitivity measurement of 100%, specificity of 89.9%, and accuracy of 94.4%. MRI produced results with a sensitivity measurement of 23.4%, specificity of 100%, and accuracy of 65.75%. Ultrasound results were more sensitive and accurate than MRI in the detection of ankle tendon tears in our study.

Ankle fracture classification: a comparison of reliability of three X-ray views versus two.

Our hypothesis was that malleolar ankle fractures could be classified with two radiographic views as reliably as with three views. Four different observers independently evaluated 99 sets of ankle radiographs. The examiners classified the ankle fractures by using both the Lauge-Hansen and Danis-Weber systems. The interobserver and intraobserver variations were analyzed by kappa statistics. With regard to intraexaminer reliability, the examiners demonstrated excellent accord in classifying the fractures in the Danis-Weber system with either three views or two views. The kappa values were comparable. In the Lauge-Hansen system, three examiners demonstrated excellent accord and one examiner demonstrated good accord in classifying the fractures. Similar kappa values were generated when examiners classified fractures with either three views or two views. With regard to interexaminer reliability, good to excellent accord was demonstrated overall among the four examiners when they used the Danis-Weber system with either three views or two views. The examiners were in good agreement when they used the Lauge-Hansen system. Similar kappa values were generated whether the examiners used three views or two views. Three radiographic views are usually ordered for evaluation of an acute ankle injury. Previous studies have shown that only two views are needed for diagnosis of a malleolar ankle fracture. This study demonstrates that malleolar ankle fractures can be classified with two views, lateral or mortise, with a reliability as good as that achieved with three views. The best agreement is achieved with lateral and mortise views.

Ultrasonographic-surgical correlation of ankle tendon tears.

This study evaluates the accuracy of ultrasonography in detecting ankle tendon tears of the peroneal, posterior tibial, and flexor digitorum longus tendons based on operative findings and clinical follow-up. A prospective study was performed in 33 patients with clinically suspected tendon injury. Sixty-eight tendons were evaluated sonographically. The diagnosis of an intrasubstance tear was made when disruption of uniform tendon architecture by hypoechoic linear or globular clefts was observed. Criteria used to diagnose complete tendon rupture included discontinuity or gap within the tendon or complete nonvisualization of the tendon. Treatment decisions were based on a combination of clinical parameters and imaging studies. Twenty-six patients had the presence or absence of tear confirmed at surgery. Five patients had a final diagnosis based on clinical findings, and two were lost to follow-up. Of the 68 tendons evaluated sonographically, 54 were directly inspected at surgery; 20 were found to be torn and 34 were intact. Ultrasonography was able to identify all tears correctly with an accuracy of 93%, a sensitivity of 100%, and a specificity of 88%. The positive and negative predictive values were 83% and 100%, respectively. The combined accuracy, sensitivity, and specificity of ultrasonography in detecting tendon tears in all patients evaluated both surgically and by clinical follow-up were 94%, 100%, and 90%, respectively.

Anterior tibialis tendon ruptures: an outcome analysis of operative versus nonoperative treatment.

Ruptures of the anterior tibialis tendon are a rare clinical entity. Case reports in the literature reveal a total of 28 cases. Unfortunately, because of the limited discourse in the orthopaedic literature, there are few guidelines regarding the treatment for these injuries. This study analyzes the treatment of 16 anterior tibialis tendon ruptures. Eight patients in this group had operative treatment of their ruptures, and eight patients had nonsurgical treatment of their ruptures. The average follow-up for the operative and nonoperative patients were 6.68 years and 3.86 years, respectively. The Foot and Ankle Outcome questionnaire provided by the American Academy of Orthopaedic Surgeons and an outcome-based foot score described by Kitaoka et al. were used as the methods of analysis. Our outcome results show no statistically significant difference between operative and nonoperative treatment in anterior tibialis tendon ruptures. The lack of statistical difference between operative and nonoperative groups may be a reflection of the age bimodality present in this study. Elderly low demand patients were treated nonsurgically and young active patients were treated operatively. Therefore, despite a lack of statistical difference present in the outcome of both groups, we still maintain the need to repair/reconstruct anterior tibialis tendon ruptures in young active patients with high functional demands. The deficits present in the nonoperative group, we believe, would not be well tolerated in a young high functional demand patient. Nonsurgical management is an appropriate alternative in low demand elderly patients.

Observer reliability in ankle radiographic measurements.

We analyzed 50 sets of ankle radiographs to determine the interobserver and intraobserver reliability when obtaining common linear and angular measurements. The radiographs were divided into two groups: one group included 25 normal ankles, and the second group included 25 fractured ankles. Each set of radiographs was evaluated independently by four different observers on two separate occasions under controlled conditions. Six radiographic parameters were measured on all 50 sets of films: syndesmosis A, syndesmosis B, syndesmosis C, the medial clear space, and the talocrural and bimalleolar angles. On the 25 sets of fracture films, four additional measurements of fracture displacement were included: displacement of the medial malleolus (mortise), displacement of the lateral malleolus (AP and lateral), and displacement of the posterior malleolus. Reliability was evaluated with an analysis of variance intraclass correlation coefficient. Among the examiners, 9 of the 10 parameters could be measured reliably. Intraobserver reliability was found to increase with the experience of the examiner.

Navicular body fractures: computerized tomography findings and mechanism of injury.

The case reports of five patients with signs and symptoms of a fracture of the tarsal navicular body are presented. Each patient underwent a computerized tomography examination to determine the extent of this fracture. Based on the computerized tomography findings, surgical or conservative management was carried out. The computerized tomography examination, combined with the patient's history, has shed new light on a previously undescribed mechanism of injury for this fracture.

The use of the Synthes 7.3-mm. cannulated screw in rearfoot and ankle surgery: a preliminary prospective study.

The authors present a preliminary prospective study of the Synthes 7.3 mm. cannulated screw used in 31 rearfoot and ankle surgeries on 29 patients. The patients had a variety of rearfoot and ankle procedures performed, in which a total of 75 screws were placed across 47 arthrodesis or osteotomy sites. The percentage of union or healing was 95.74% for the joints or sites involved. The average healing time was 2.71 months. The techniques for placement of the screw are described.

The effects of cheilectomy on dorsiflexion of the first metatarsophalangeal joint.

Our purpose in this study was to determine the effects of cheilectomy on the mechanics of dorsiflexion of the first metatarsophalangeal (MTP) joint. Ten fresh-frozen cadaver feet were utilized, of which two demonstrated radiographic evidence of hallux rigidus. Each specimen was rigidly mounted on a custom-made slide tray that was articulated with a hinge mechanism designed to dorsiflex the first MTP joint. Range-of-motion measurements were made on the first MTP joint. Cheilectomy of 30% of the metatarsal head diameter was performed. Lateral radiographs with the beam centered on the MTP joint were taken with the joint at neutral, 20 degrees, 40 degrees, and at the limits of dorsiflexion. This process was repeated after a 50% cheilectomy was performed. The radiographs were examined for changes in joint congruence and in patterns of surface motion as the hallux moved from neutral to full dorsiflexion. Instant centers of rotation were determined by a method first described by Rouleaux. We constructed surface velocity vectors to describe patterns of motion of the first MTP joint. The mean dorsiflexion of the first MTP joint was 67.9 degrees and increased to 78.3 degrees after 30% cheilectomy. The increase in dorsiflexion was significantly greater in the two specimens with hallux rigidus (33%) than in the other specimens (12.1%). After both levels of cheilectomy, the proximal phalanx demonstrated pivoting at the resection site on the metatarsal head. This pivoting resulted in abnormal motion patterns across the MTP joint. Normal sliding motion predominated in early dorsiflexion, with compression peaking at the end stage of dorsiflexion, producing jamming of the articular surfaces. Cheilectomy significantly increased dorsiflexion of the MTP joint, but resulted in abnormal motion patterns. The increase in dorsiflexion resulted from pivoting of the proximal phalanx on the metatarsal head, resulting in anomalous velocity vectors and compression across the MTP joint.

The use of ultrasonography for the detection of retained wooden foreign bodies in the foot.

The efficacy of ultrasonography for the detection of wooden foreign bodies in the foot was analyzed retrospectively. Twenty patients underwent real-time, high-resolution ultrasound studies (7.5 or 10 MHz, linear array transducers) to rule out the presence of a wooden foreign body in their feet. Ten out of the 20 patients had positive ultrasound findings for a wooden foreign body. With the aid of the ultrasound study and preoperative markings, the subsequent mean surgical time was 20.8 minutes, with a 100% retrieval rate of the foreign body. Ultrasound was found to be 100% sensitive in the detection of wooden foreign bodies in the soft tissues of the foot. Ultrasonography should be considered an important diagnostic modality in the foot and ankle surgeon's armamentarium for the detection of retained wooden foreign bodies.

The influence of x-ray orientation on the first metatarsocuneiform joint angle.

The purpose of this study was to determine whether the first metatarsocuneiform (MC) joint angle is affected by the orientation of the x-ray beam, whether it can be reliably measured, and, therefore, whether it is a valid indication of tarsometatarsal fusion as an adjunct to hallux valgus surgery. Each of seven cadaver feet were loaded to 350 newtons in a Plexiglas apparatus that maintained the foot in a plantigrade position. The loading apparatus was positioned to simulate a 10 degrees, 20 degrees, and 30 degrees dorsal angulation of the x-ray beam. At each position, simulated weight-bearing radiographs were obtained for each foot. Three observers independently measured the first MC angle and the first intermetatarsal (IM) angle on all the radiographs. The data collected were analyzed by the components of variance. The inclination of the first MC joint lessons significantly as the orientation of the x-ray beam changes from a 10 degrees to a 20 degrees tilt. The three examiners' mean MC angles and mean IM angles from the three sets of radiographs were not statistically different from each other, implying that there were minimal examiner-to-examiner differences in measuring these angles. There were no significant differences in measurements between examiners, suggesting that the first MC and first IM angles can be measured reliably. There was a significant difference in the first MC angle, with different orientations of the foot with respect to the x-ray beam, suggesting that this angular measurement should not be used as an indication for tarsometatarsal arthrodesis.