Medial impingement syndrome of the anterior tibiotalar fascicle of the deltoid ligament on the talus.

Eleven patients with medial impingement syndrome of the anterior tibio-talar fascicle (ATTF) of the deltoid ligament on the talus were identified. Six sustained inversion injuries, one talus and four ankle fractures. The mean preoperative Ankle-Hindfoot Scale (AHS) was 56 and the postoperative was 87. Surgical debridement of the ATTF was performed. A thickened ATTF and localized synovitis were seen. Talar osteophytes were removed in 8 patients. Mean follow up 4 years. Nine patients had good to excellent results and all patients returned to work.

Plantarflexion torque following reconstruction of Achilles tendinosis or rupture with flexor hallucis longus augmentation.

Nine patients treated surgically for Achilles tendon rupture (7 patients) or tendinosis (2 patients) with primary repair or debridement and augmentation with the flexor hallucis longus muscle-tendon unit were evaluated at a mean of 19 months postoperative. Subjective evaluation revealed a high level of satisfaction. All patients returned to work and only two patients reported limitation in their recreational activities. The mean post-operative AOFAS Ankle-Hindfoot Score was 90 points. Four patients reported mild occasional pain and one patient complained of moderate daily pain. Motion assessment showed a 20% increase in the hallux MTP dorsiflexion compared to the non-operative side (p = 0.045). No difference in ankle motion was noted. Cybex II+ dynamic evaluation of plantarflexion peak torque was complete on both extremities. The torque deficit on the reconstructed extremity was 20% (p = 0.01) at 120 degrees per second and 26% (p = 0.003) at 30 degrees per second. There is no significant difference between the torque deficit recorded for patients with Achilles rupture and those with Achilles tendinosis. A trend toward improved torque production with longer follow up was observed.

Osteoid osteoma of the lateral talar process presenting as a chronic sprained ankle.

Pathologic conditions of the lateral talar process may be difficult to diagnose using physical examination and roentgenographs. A computed tomography scan of the hindfoot is often useful to define lesions of the lateral process. We report a case of osteoid osteoma of the lateral talar process that defied diagnosis for 4 years. The patient had an antecedent history of an inversion injury, which had been treated as a chronically painful sprained ankle without resolution of symptoms. The tumor was ultimately identified on a computed tomography scan, best seen on a coronal section through the talus. The patient had complete relief of pain after excisional biopsy of the tumor.

Triple arthrodesis in adults using rigid internal fixation: an assessment of outcome.

The intermediate outcome of patients who underwent a triple arthrodesis for the treatment of adult foot disorders was evaluated with an outcome tool to determine if their pain and functional status were improved. We evaluated 63 feet in 57 patients who underwent a triple arthrodesis using rigid internal fixation for the treatment of hindfoot deformities associated with symptomatic arthrosis. Twenty-four men and thirty-three women, with an average age of 54 years, were evaluated. The average follow-up was 30 months. Multiple diagnoses contributed to hindfoot deformities with secondary arthrosis. Iliac crest bone graft was used in 56 of 63 cases (89%). Percutaneous heel cord lengthening was done in 53 of 63 cases (84%). Twenty-four of the thirty patients (80%) returned to work. Twenty-five patients were retired and two were unemployed before surgery. All patients except two (97%) were satisfied with the surgery and would have the surgery again. The average American Orthopaedic Foot and Ankle Society Ankle-Hindfoot preoperative score was 28 points, and the average postoperative score was 81 points (P < 0.0001). In the radiographic measurements, there was an average improvement of 12 degrees in the lateral talometatarsal angle, 7 degrees in the lateral talocalcaneal angle, and 10 degrees in the AP talometatarsal angle (P < 0.0001). Complications experienced included two varus malunions, two valgus malunions, two nonunions, two deep vein thromboses, one distal fibula stress fracture, and one wound infection. Of the 26 feet in 22 patients with mortise views available, 10 feet (38%) had evidence of ankle arthrosis and 19 feet (73%) had some degree of talar tilt postoperatively.

Excrescent lesion: a diagnosis of lateral talar exostosis in chronically symptomatic sprained ankles.

The excrescent lesion is a symptomatic anterolateral exostosis at the insertion of the anterior talofibular ligament. It is found in patients with chronic ankle pain after inversion injuries. It is most reliably diagnosed by computed tomography scan, but physical examination and oblique radiographs are suggestive in most cases. A technique for surgical excision and, in some cases, repair of the anterior talofibular ligament is described. Five patients having a history of inversion sprains of the ankle, without significant symptomatic improvement for a mean of 21 months after the injury, were evaluated. None had significant instability in the ankle or subtalar joints, clinically or with stress radiographs. The diagnosis of excrescent lesion was confirmed with computed tomography scan in all five patients. Each underwent excision of the exostosis. Removal of the exostosis produced laxity of the anterior talofibular ligament in four of the patients and required an additional modified Broström procedure to tighten the anterior talofibular ligament. Clinical results were evaluated at a mean of 33 months postoperatively, using the Ankle-Hindfoot scale from the American Orthopaedic Foot and Ankle Society. The three patients without pending claims for Workers' Compensation or related litigation all had excellent results (mean score, 93 points). Two patients with active legal claims had fair and poor results (mean score, 53 points).

Clinical outcome of arthrodesis of the ankle using rigid internal fixation with cancellous screws.

Thirty consecutive patients underwent arthrodesis of the ankle using rigid internal fixation with cancellous screws between 1992 and 1996. One patient died of causes unrelated to the surgery before bony union. Primary fusion occurred in 27 of the remaining 29 patients (93%). The average time to primary union was 9 weeks. Two patients developed a delayed union and were treated with an additional bone-grafting procedure. Ultimately, each of the 29 patients went on to fusion. Use of tobacco during the postoperative period had no apparent effect on the rate of fusion or time to fusion. Twenty-five patients were available for clinical evaluation at an average of 24 months after surgery. Subjective evaluation using questionnaires revealed a high level of satisfaction. All patients stated that they would undergo the procedure again. The mean postoperative score on the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale was 81 points, compared with 48 points preoperatively (of a possible 100). Constant pain was the reason given by all patients for seeking treatment. After the arthrodesis, pain was reported as absent in 13 and occasional in 12 patients. All patients noted less pain in the hindfoot after fusion of the ankle. Active litigation and Workers' Compensation claims during the perioperative period had a significant negative effect on scores on the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale and seemed to decrease patients' perceived ability to return to work.

Osteotomy for malunion of a talar neck fracture: a case report.

A malunion of the talar neck after a Hawkins type II fracture/dislocation of the talar neck occurred in a 34-year-old man after nonoperative treatment. Rigid varus deformity of the forefoot was a source of severe pain and disability in this patient. We describe our surgical technique for osteotomy of the talar neck with insertion of a tricortical iliac crest bone graft to correct the deformity. At follow-up (56 months), the patient had consistent relief of pain and was employed at his preinjury job doing heavy labor. The score on the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale improved from 11 points, preoperatively, to 85 points, postoperatively. Radiographs showed maintenance in the position of the osteotomy and no evidence of avascular necrosis in the talar body. Evidence of arthrosis of the talonavicular joint was apparent radiographically, but the patient did not complain of symptoms referable to this area.

Radiation exposure during skeletal traction treatment of pediatric femoral fractures.

Radiation-exposure data during femoral fracture management has not been previously reported. We report a retrospective analysis of radiation exposure in 45 patients aged 5-12 years (average, 8.3) with isolated femoral shaft fractures treated by 90/90 degrees femoral skeletal traction. Group I had 32 patients aged 5-9 years (average, 7.3), and group II had 13 patients of an average age of 10.7 years. Total average radiation dose before casting was 0.699 rads and was independent of age and gender. In addition to potential complications of tractions and increased hospital stay with attendant fiscal and psychosocial burdens, radiation exposure with this type of management, in this series, was significant.

The use of endosteal substitution in the treatment of recalcitrant nonunions of the femur: report of seven cases.

Seven patients, with an average age of 53 years, were treated for bone loss or recalcitrant nonunions of the femur. The average duration from initial injury to presentation was 37 months (range 4-92 months). The patients had undergone one to eight (mean, 3.9) previous surgical attempts at achieving union. The nonunion involved the diaphysis in three patients, the diaphyseal-supracondylar junction in three patients, and the pertrochanteric region in one patient. All patients were treated using a standard lateral plate in combination with an endosteal plate and primary iliac crest bone grafting. The mean surgical time was 6.3 h, and the average blood loss was 1.7 L. There were three complications, including one superficial wound infection, one nonfatal pulmonary embolism, and one wound hematoma. At a mean follow-up of 12.6 months (range 4-24 months), all fractures had healed with an average time to union of 19.2 weeks (range 15-36 weeks). Knee flexion averaged 118 degrees (range 100-135 degrees), and all patients were satisfied with the operative procedure. Endosteal plating, in combination with a standard lateral plate and iliac crest bone-grafting, can successfully treat difficult nonunions of the femur.

Developmental alterations in the sensitivity of hippocampal NMDA receptors to AP5.

Changes in the properties of the N-methyl-D-aspartate (NMDA) receptor are proposed as a factor in the decrease in synaptic plasticity during maturation of the brain. Alterations in the hippocampal NMDA receptor population were studied during development by comparing competitive antagonist efficacy during a window characterized by hyperexcitability and active synaptogenesis to that seen in a more mature period. A developmental change in the sensitivity of the N-methyl-D-aspartate (NMDA) evoked response to the competitive antagonist D(-)2-amino-5- phosphonopentanoic acid (D-AP5) was observed by whole-cell mode voltage-clamp, intracellular and extracellular recordings in hippocampal slices. These differences were observed in the portions of the hippocampus that contain the terminal axon arbors of the CA3 pyramidal neurons, the synaptic fields of the Schaffer collateral, associational and commissural pathways. The apparent antagonist efficacy was 2-3 times greater in immature slices obtained on postnatal day (PND) 10-16 than that observed in more mature tissue (> PND38). Given the possible role of the NMDA receptor in network plasticity, these observations could indicate a role for the molecular diversity of this important receptor subtype family in the maturation of hippocampal pathways.

Protective Plasmodium knowlesi Mr 74,000 antigen in membranes of schizont-infected rhesus erythrocytes.

The immunogenic Plasmodium knowlesi (H strain) Mr 74,000 protein in membranes of schizont-infected rhesus erythrocytes was purified on a large scale, free of other polypeptides as monitored by dodecyl sulfate polyacrylamide gel electrophoresis and isoelectric focusing. In a limited vaccination trial, four rhesus monkeys were immunized four consecutive times with the Mr 74,000 protein and Freund's complete and incomplete adjuvants. Two monkeys were injected with adjuvant only. Upon challenge with 10(4) viable P. knowlesi schizonts of the heterologous W strain, the control monkeys developed fatal parasitemias after 7 d. In contrast, the vaccinated monkeys exhibited a delayed onset of patent parasitemias and underwent self-cure on days 14 to 16 after peak parasitemias of between 7 and 11%. The protective immunity that was induced crossed different strains of P. knowlesi. Blood smears at the time of cure demonstrated limited reinfection, as indicated by the presence of normally appearing ring and trophozoite stages. The absence of schizont stages in the peripheral blood suggested a specific interruption of the erythrocytic schizogony at that stage. Immunochemical analyses of the rhesus sera revealed antibody only against the Mr 74,000 protein after the first two immunizations. Upon repeated antigen injection, antibodies reacted with components of Mr of approximately 102,000, 140,000, and 230,000 in addition to the Mr 74,000 protein. Besides immunological cross-reactivity, relatedness between all four immune-precipitated proteins was indicated by a greater than 50% tryptic peptide homology, suggesting that the Mr 230,000 component represents a precursor protein that is cleaved within the infected erythrocyte into proteins with Mr of approximately 140,000, 102,000, and 74,000.

Simian virus 40 (SV40)-specific isoelectric point-4.7--94,000-Mr membrane glycoprotein: major peptide homology exhibited with the nuclear and membrane-associated 94,000-Mr SV40 T-antigen in hamsters.

Tryptic peptide maps of electrophoretically purified 94,000-molecular weight (relative) (Mr) nuclear and membrane-associated simian virus 40 (SV40) T-antigens, TN and TM, respectively, were compared to those of the SV40-specific isoelectric point (pI)- 4.7--94,000-Mr plasma membrane component reactive with anti-T-sera from Syrian golden hamsters. Bidimensional thin-layer electrophoresis and chromatography of TN labeled with 125I revealed about 27 tryptic peptides. A similar number of peptides was identified for TM and the pI-4.7--94,000-Mr component. A peptide homology between TN and TM or TN and the pI-4.7-94,000-Mr protein exists and indicates that the previously described pI-4.7--94,000-Mr membrane component represents TM. Only 4 of 27 peptides were labeled when TM was subjected to lactoperoxidase-catalyzed radioiodination from the outer surface of the plasma membrane. One of these TM peptides was metabolically labeled with [14C]glucosamine. The data indicate that TM is partially exposed on the cell surface and represents a glycosylated form of TN. Closely associated with TM is a pI-4.5--55,000-Mr membrane component. This component does not exhibit significant peptide homology with the 94,000-Mr SV40 protein and, therefore, appears to be coded for by the host cell genome.

Pacemaker bigeminy: pseudomalfunction.

The first reported unique case of atrial synchronized pacemaker-induced bigeminy is described and related literature is briefly discussed. The arrhythmia reported in this case can be erroneously misinterpreted as a malfunctioning pacemaker unless the physician is fully familiar with the specific nature of the atrial synchronized pacemaker. By recognizing this type of pacemaker bigeminy as an arrhythmia simply related to a normally functioning pacemaker, unnecessary surgery can be avoided.