Ultrafast Formation of a Fermi-Dirac Distributed Electron Gas.

Time- and angle-resolved photoelectron spectroscopy with 13 fs temporal resolution is used to follow the different stages in the formation of a Fermi-Dirac distributed electron gas in graphite after absorption of an intense 7 fs laser pulse. Within the first 50 fs after excitation, a sequence of time frames is resolved that are characterized by different energy and momentum exchange processes among the involved photonic, electronic, and phononic degrees of freedom. The results reveal experimentally the complexity of the transition from a nascent nonthermal towards a thermal electron distribution due to the different timescales associated with the involved interaction processes.

Time-resolved ARPES with sub-15 fs temporal and near Fourier-limited spectral resolution.

An experimental setup for time- and angle-resolved photoelectron spectroscopy with sub-15 fs temporal resolution is presented. A hollow-fiber compressor is used for the generation of 6.5 fs white light pump pulses, and a high-harmonic-generation source delivers 11 fs probe pulses at a photon energy of 22.1 eV. A value of 13 fs full width at half-maximum of the pump-probe cross correlation signal is determined by analyzing a photoemission intensity transient probing a near-infrared interband transition in 1T-TiSe2. Notably, the energy resolution of the setup conforms to typical values reported in conventional time-resolved photoemission studies using high harmonics, and an ultimate resolution of 170 meV is feasible.

Subtalar joint arthroscopy for sinus tarsi syndrome: a review of 29 cases.

Twenty-nine consecutive patients who underwent diagnostic or therapeutic subtalar joint arthroscopy for sinus tarsi syndrome were retrospectively reviewed. The mean length of follow-up was 18 months. There was a history of trauma in 86% of the patients, with an inversion sprain being the most common predisposing injury (63%). All patients had a primary preoperative diagnosis of sinus tarsi syndrome. Magnetic resonance imaging was useful in identifying subtalar joint chronic synovitis and/or fibrosis in all 26 patients who were imaged. Subtalar joint synovectomy was the most common procedure performed. Twelve patients had 15 additional operative procedures. One patient required an arthrotomy secondary to arthrofibrosis. There were no postoperative complications. The mean return to full activity was 4 months. The mean postoperative AOFAS Ankle-Hindfoot Scale score was 85 points. Subtalar joint arthroscopy has proven to be a relatively safe and effective diagnostic and therapeutic technique in the management of sinus tarsi syndrome.

In situ tibialis posterior to flexor digitorum longus tendon transfer for tibialis posterior tendon dysfunction: a simplified surgical approach with outcome of 11 patients.

Outcomes for 11 patients who underwent an in situ tibialis posterior tendon to flexor digitorum longus tendon side-to-side anastamosis as the sole procedure for stage 2 tibialis posterior tendon dysfunction were reviewed. The average follow-up was 34.4 months. Using the American Orthopedic Foot and Ankle Society hindfoot rating scale, a mean improvement of 39.3 points was achieved, with preoperative scores of 38.8 improving to 78.1 postoperatively. Good to excellent results were achieved in nine patients. The in situ side-to-side anastamosis is technically easier to perform, has less tissue trauma, and compares favorably with other soft-tissue procedures and reconstructions for stage 2 tibialis posterior tendon dysfunction. Performing this transfer alone, while leaving the flexor digitorum longus tendon intact, theoretically provides a stronger transfer as the length-tension relationship of the flexor digitorum longus tendon is maintained near its physiologic level. The procedure can consistently restore inversion ability to the rearfoot and stop the progression of tibialis posterior tendon dysfunction.

Arthroscopic monopolar radiofrequency thermal stabilization for chronic lateral ankle instability: a preliminary report on 10 cases.

This study represents a preliminary review of 10 patients having undergone arthroscopic monopolar thermal stabilization for ankle instability from October 1996 to June 1998. All patients in this study expressed mild to moderate chronic ankle instability complaints and were dissatisfied with their attempts at conservative care. Subjective clinical results were evaluated in all patients having undergone this procedure utilizing a modified version of the American Orthopedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale. In addition, eight of these patients underwent pre- and postoperative stress radiographs. The average age of the patient population in this study was 34.5 +/- 9.26 years. The preoperative AOFAS scores averaged 58.3 +/- 8.96 and the postoperative were 88.1 +/- 11.09 points. Patients returned to full activities on the average of 3 months. Postoperative ankle varus stress test reduced on the average of 2.8 degrees +/- 2.77 degrees, while the anterior drawer measurements reduced 4.8 +/- 1.83 mm. The reduction in anterior drawer test amounted to an approximate 60% decrease in talar excursion postoperatively. All patients who underwent this procedure achieved ankle stability and commented that they would undergo the procedure again.

Flexor hallucis longus dysfunction.

Nineteen consecutive cases of flexor hallucis longus stenosing tenosynovitis that underwent operative tenolysis from September 1994 to December 1996 were retrospectively reviewed. This is classically a disorder of ballet dancers, and to a much lesser extent, running athletes. The patients were primarily nonathletic, male, and middle-aged. The mean symptom duration was 20 months, multiple physicians had been encountered, and misdiagnosis was common. Patients presented with overlapping signs and symptoms of flexor hallucis longus tendinitis, plantar fasciitis, and tarsal tunnel syndrome. A cross-reference of patients with posteromedial ankle pain, medial arch pain, and/or a positive Tinel's sign revealed that 14 (74%) and 6 (32%) feet had two of three, or all three signs, respectively. Magnetic resonance imaging and tenography proved valuable in establishing the correct primary diagnosis. Nonoperative protocols were unsuccessful. Flexor hallucis longus tenolysis was successful in each case with a mean return to regular activity at 9 weeks. Flexor hallucis longus stenosing tenosynovitis may be more prevalent than reported and should be a diagnosis of inclusion among all patient populations who present with posterior ankle, medial arch, and/or tarsal tunnel symptoms.

Application of distal metaphyseal osteotomy for treatment of high intermetatarsal angle bunion deformities.

This is a retrospective study of 10 patients (13 feet) with moderate to severe hallux valgus who underwent a chevron or modified chevron osteotomy with multiple adjunctive soft-tissue releases for surgical treatment. Radiographic and subjective results were evaluated with an average follow-up of 24 months (range, 10-41). Preoperative criteria included an intermetatarsal (IM) angle of greater than 16 degrees (average of 18.4 degrees) and painful hallux valgus deformity. Average preop hallux abductus was 35.4 degrees (range, 25 degrees-48 degrees). The average reduction in the actual IM angle was (-) 5.2 degrees with a relative IM correction of (-) 11.6 degrees. Average postoperative hallux abductus angle was 7.0 degrees (range, 0 degree-22 degrees). Subjectively, all patients were satisfied with their results and stated they would have the procedure again. No complications were noted in this patient population, including, infection, avascular necrosis, hallux varus, and recurrence of deformity. The chevron osteotomy was found to be successful in this population with high intermetatarsal angles when appropriate consideration was given to correction of soft-tissue-deforming forces and contractures.

PMMA bead versus parenteral treatment of Staphylococcus aureus osteomyelitis.

A. rabbit model of Staphylococcus aureus osteomyelitis was used to compare 3 weeks of clindamycin-impregnated polymethylmethacralate (PMMA) bead treatment with 3 weeks of gentamicin-impregnated polymethylmethacralate bead treatment, 4 weeks of parenteral clindamycin treatment, and surgical debridement without any antibiotic treatment. The animals were weighed throughout the course of the experiment and cortical bone and marrow flush specimens were obtained for bacterial culture at the end of therapy. The cortical specimens were bacteria free in 100% (6/6) of the animals receiving parenteral clindamycin, 83% (5/6) of the animals in the clindamycin PMMA group and, none of the animals in the gentamicin PMMA group. The marrow flush specimens were bacteria free in 83% (5/6) of the animals in the parenteral clindamycin group, 67% (4/6) of the animals in the clindamycin PMMA group, and 40% (2/5) of the animals in the gentamicin PMMA group. While these findings are preliminary and further studies with larger numbers of animals are needed, the authors suggest that when PMMA bead therapy is being contemplated, serious consideration should be given to replacing gentamicin with clindamycin in treatment of gram-positive osteomyelitis. Furthermore, incorporation of clindamycin with gentamicin (or tobramycin) should be considered when treating mixed gram-positive and gram-negative osteomyelitis.

Iliac crest donor site morbidity in foot and ankle surgery.

The authors retrospectively reviewed anterior iliac crest donor site morbidity in 40 consecutive patients (42 donor sites) who underwent graft harvesting for reconstructive foot or ankle surgery. The mean time to follow-up was 22 months (range, 1 to 48 months). The overall complication rate was 2.4%, with one early minor complication and no major complications. The authors conclude that anterior iliac crest-harvesting techniques that rely on minimal soft tissue dissection and the removal of small-to-moderate volumes of bone have reduced frequencies of minor and major donor site complications.

Sesamoid complex disorders.

Disorders of the hallux sesamoids and associated soft-tissue structures are commonly seen. With a differential diagnosis consisting of no fewer than 30 conditions, establishing an accurate diagnosis can be challenging but is important to appropriate treatment implementation. An understanding of first metatarsophalangeal joint anatomy, function, and current diagnostic technology aids the practitioner in the diagnosis and successful treatment of these often overlooked and anecdotally managed disorders.

Arthroscopy of the calcaneocuboid and talonavicular joints.

The authors describe the anatomy, portal placement, technique, indications, and preliminary results of seven cases of calcaneocuboid or talonavicular joint pathology that underwent elective investigational diagnostic or therapeutic arthroscopy with a follow up of 3-14 months. All patients had failed available conservative therapy. Results of treatment were five excellent and two good cases. Two patients required arthrotomy. There were no complications associated with portal placement, arthroscopic technique, or instrumentation. Arthroscopy of the calcaneocuboid and talonavicular joints has proven to be a relatively safe and valuable diagnostic and therapeutic tool. It is hoped that advances in small joint arthroscopy application will encourage further technological evolution in arthroscopic instrumentation and establish a foundation for further arthroscopic exploration of the small joints of the foot.

CCPM and podiatric medical education. Preparing for the 21st century.

There are many changes on the horizon that will affect how we teach the future practitioners of podiatric medicine. The author describes the processes undertaken to date at the California College of Podiatric Medicine (CCPM), as well as the vision of tomorrow, for podiatric medical education. The educational system that will result from these changes will be more efficient; it will better meet the needs of students; and, it will broaden their base of knowledge, all to improve care given to the patient.

Magnetic resonance imaging of traumatized ligaments of the ankle.

The clinical examination of acute soft tissue injuries of the ankle does not necessarily help to delineate the extent of injury. Ankle stress radiographs and arthrography have been applied for a more accurate assessment of the actual degree of ligamentous damage. However, these studies do not define the level of the ligament tear of the relationship of torn ligament ends to one another. This information would seem to be valuable in deciding whether a conservative or surgical approach would be advisable. The following study evaluated the possible role of magnetic resonance imaging in assessment of these injuries. The ability to assess ankle ligaments was first undertaken. Once this was successfully performed, magnetic resonance imaging was used to assess the degree of ligament damage in 15 patients. Magnetic resonance imaging proved to be comparable to arthrography. It also provided additional valuable information.

Antibiotic-impregnated bone cement: an in vitro comparative analysis.

This manuscript examines the in vitro antibacterial activity of eight different antibiotics when mixed with polymethyl methacrylate. Two different parameters are presented as being important considerations in the choice of antibiotic. One parameter is the bacterial inhibition created by the direct contact of the antibiotic-impregnated bone cement. The second parameter is the bacterial inhibition produced by diffusion of antibiotic from the bone cement into the surrounding liquid medium. These two experimental models were created to establish the contiguous and remote antimicrobial effects of antibiotic-impregnated bone cement.

Radiographic evaluation of inflammatory arthritis of the foot.

This article provides a brief overview of the radiographic appearance of the more commonly encountered arthridities in the foot. Also reviewed is a stepwise approach to interpreting radiographs in a patient suspected of having a synovial-based disease.

Perioperative considerations in the arthritic patient.

It should become clear that the surgeon's responsibility to the patient does not end with knowledge of the surgical procedure. The arthritis patient poses a vexing problem in a variety of ways. The surgeon not only has to understand the particulars of surgery, but also should have a working knowledge of the disease process so that the chance for complications is lessened. Because discussion of each articular disorder is beyond the scope of this article, readers should continually try to review these areas, especially in light of the everchanging attitudes in rheumatology. The arthritis patient is prone to many potential problems, some avoidable and others inevitable. It is obviously the avoidable ones that we most concern ourselves with. Because the patient with arthritis very commonly undergoes multiple reconstructive surgeries, the risks of complications are naturally greatly increased. To any patient with chronic disease, any misfortunes from surgery are all the more discouraging. The team approach will go a long way in providing the most appropriate care. This has been aptly stated as: "The combination of a radical rheumatologist, a conservative surgeon, a cooperative physiatrist and physical therapist, and an informed motivated patient should lead to the best combination of results obtainable in the present state of the art, and reduce the incidence of complications.

Implant arthroplasty in the rheumatoid arthritic patient.

Implant arthroplasty was introduced with the intention that it would relieve pain, provide stability, provide motion, and allow the part to be mobilized. It is a relatively recent phenomenon and long-term results remain difficult to predict.

Complications of subtalar arthroereisis.

Arthroereisis procedures involving the subtalar joint in the pediatric flatfoot have had great success in limiting/preventing abnormal or destructive pronating forces transmitted into the foot. This report presents actual and potential complications of these procedures.