Evaluation of surgical experience and the use of an osteotomy guide on the apical angle of an Austin osteotomy.

BACKGROUND: Distal osteotomies of the first metatarsal are commonly used to correct hallux valgus deformities. Of the distal osteotomies, the Austin osteotomy is popular among foot surgeons on an international level. The precision of the osteotomy is important to achieve a congruous osteotomy. OBJECTIVES: The purpose of this study was to examine the effects of experience and technique on creating a precise Austin osteotomy. METHOD: Three individuals with varying levels of experience (student, resident and podiatric physician) created Austin osteotomies in metatarsal sawbones, using three different techniques (freehand, guide wire and osteotomy guide). The medial and lateral apical angles were measured, and the mean, standard deviation, and range of the angles were calculated. The differences between medial and lateral angles were also calculated. RESULTS: The results indicated that the mean and range of the angles varied considerably with the freehand and guide wire techniques at all experience levels. The angles were accurate and consistent for all experience levels; however, when an osteotomy guide was used. The use of an osteotomy guide also noticeably reduced the number of divergent and convergent osteotomies. CONCLUSIONS: The use of an osteotomy guide consistently resulted in a more precise Austin osteotomy for all experience levels.

Evaluation of fibrocartilage regeneration and bone response at full-thickness cartilage defects in articulation with pyrolytic carbon or cobalt-chromium alloy hemiarthroplasties.

Hemiarthroplasty is one method used to treat osteoarthritic joints. Often, however, an adverse response of the articular cartilage to the metal implants occurs. The purpose of this study was to evaluate and compare the response of a surgically created defect to pyrolytic carbon and cobalt-based alloy hemiarthroplasties. The cartilage on the lateral side of the tibial plateau of a canine knee joint was abraded to create a full-thickness defect. Two small holes were drilled into the exposed subchondral bone. Next, either a carbon or metal implant was placed in the lateral femoral condyle. The implantation period was 1 year. Histologic examination of the tibial defects revealed a smooth bony surface for both implant groups. In addition, there was no evidence of a residual adverse inflammatory response nor of a significant increase in subchondral bone formation for either group. Surface cracks resulting from the presence of the implant were seen in 14% of the carbon implant specimens and in 100% of the metal implants. Fibrocartilage regeneration was seen in 86% of the carbon implants and in 25% of the metal implants. Thus the carbon appears to be better tolerated mechanically compared to wrought cobalt-chromium alloy. Pyrolytic carbon shows promise for use in hemiarthroplasty.

Mechanical and histological fixation of hydroxylapatite-coated pyrolytic carbon and titanium alloy implants: a report of short-term results.

Historically, pyrolytic carbon has been a material for cardiovascular applications, but it has several properties suited for orthopedic uses as well. Pyrolytic carbon has an elastic modulus similar to bone and is highly fatigue resistant, but has not been used in orthopedics because of poor fixation to bone. Plasma sprayed hydroxylapatite (HA) has significantly improved the bonding of bone to titanium alloy implants. The effect of plasma-sprayed HA on pyrolytic carbon implants was investigated in this study. Cylindrical samples were implanted through a single cortex in Beagle femurs. The animals were sacrificed after 8 weeks, and a mechanical push-out test was performed on the implants immediately after explantation. Samples were microradiographed, stained for histology, and examined histomorphometrically. Interface strength for each type of implant was calculated. Pyrolytic carbon showed almost no attachment strength with an average strength value of 1.59 MPa. HA-coated pyrolytic carbon (8.71 MPa) yielded the same interfacial strength as HA-coated titanium (8.71 MPa). Histology revealed that bone was in direct apposition to all implants, both HA coated and noncoated. Failures occurred between the core material and the coating, or within the coating, but not at the bone/HA interface. Histomorphometry results confirmed that the two types of HA-coated implants had more bone apposition than the uncoated pyrolytic carbon implants. It was concluded that a plasma sprayed HA coating significantly improves the bone fixation of pyrolytic carbon.

Absorbable fixation of first ray osteotomies.

A study was undertaken to evaluate the use of ORTHOSORB absorbable pin fixation for distal first ray osteotomies, in the management of hallux valgus. Data presented include 20 osteotomies fixated with ORTHOSORB absorbable pins in a crossing fashion, performed in 14 patients with an average follow-up period of 11 months. The patient population presented with an average age of 30, all were female. The patient pool was evaluated for hallux abductus, metatarsus primus varus, tibial sesamoid position, quality and quantity of range of motion at the first metatarsophalangeal joint, metatarsalgia, and osteolysis, both before and after surgery. No osteotomy displacement, delayed healing, or osteonecrosis was noted in this study. No adverse clinical reactions were observed in response to the ORTHOSORB pins.

Sectional morphology of the first metatarsophalangeal joint.

This study was designed to examine the sectional morphology of the first metatarsophalangeal joint. Sections were cut in the transverse or sagittal planes from the distal aspect of the first metatarsal and the proximal aspects of the proximal phalanx. These sections were then x-rayed and measurements of the radiographs were taken, in order to attempt to quantify variation in articular surfaces among the various sections. In addition, descriptive statistics of the height and width of the cross section at the mid-diaphysis of the first metatarsal and associated proximal phalanx are presented. Trabecular patterns of the head of the first metatarsal and the base of the proximal phalanx are described based on sectional radiographs. Differences in trabecular patterns between diseased and nondiseased bones are also described. These data are presented as an aid in the accurate sizing of future prosthetic first metatarsophalangeal joint designs.

A review of pyrolytic carbon: application in bone and joint surgery.

The authors review pyrolytic carbon as a biomaterial. Its potential applications in bone and joint surgery are discussed. This manuscript includes work performed in the early 1980s through present day research.

Silicone implant arthroplasty: a retrospective analysis.

Fifteen patients totalling 19 first metatarsophalangeal implants were evaluated both subjectively and objectively. The average time of follow-up was 5.9 years. Sixteen implants were evaluated radiographically and the incidence of complications including implant deformation, bony erosions, and bony encroachment is reported. Postoperative clinical evaluation revealed several of the patients complained of pain and stiffness. Postoperative motion was restricted in most patients and toe purchase was present in only 6 of 16 patients. Despite the clinical objective findings, patient satisfaction was very favorable. Although the apparent complication rate appeared high, the authors recommend an effort be made to develop a multicentered retrospective analysis to find the true incidence of first metatarsophalangeal implant complications.

The Austin bunionectomy: a follow-up study.

The Austin procedure, a distal metaphyseal "V" osteotomy for the management of hallux valgus was evaluated in several distinct patient groups. The results of the procedure were found to be both reproducible and predictable. Medial capsular reefing in an attempt to maintain the intermetatarsal angle reduction or hallux alignment does not appear to enhance the postoperative results.

Evaluation of lower extremity ulcerations.

The authors provide a simplified system for the initial approach and diagnostic evaluation of the more commonly occurring ulcerations encountered by the Podiatric physician. This system provides a logical basis for evaluation, identification, and therapeutic intervention of lower extremity ulcers.

Forces on the first metatarsophalangeal joint: a pilot study.

The following is a pilot study designed to examine the forces in and around the first metatarsophalangeal joint during the contact phase of the normal gait cycle. The architecture of this study was designed to be simple, effective, and repeatable with minimal complications. This study used a force plate to examine ground reaction forces with the simultaneous use of a video tape recorder to provide overlapping images of the angular displacement of the proximal phalanx on the first metatarsophalangeal joint coinciding with these ground reaction forces. Peak ground reaction force was found to be 1.16 x body weight while the proximal phalanx was found to be maximally dorsiflexed just 0.09 seconds after the peak ground reaction force. The mean range of motion during this process was found to be 31.54 degrees.

Challenges and opportunities facing the Ohio College of Podiatric Medicine.

This article presents the problems and challenges facing the Ohio College of Podiatric Medicine in the view of its President and its Chief Academic Officer. It explores the progress made and the challenges facing the Ohio College overall and in the areas of education. It presents an exciting new vision of the style of podiatric medical education, and the methods that are and will be used to assess the quality of the educational program.

Morphological considerations of the first metatarsophalangeal joint.

This study was designed to examine the external morphology of the metatarsophalangeal joint and of the hallux. Approximately 187 first metatarsals and their associated proximal phalanges where measured for ten linear variables from human skeletal specimens housed in the Cleveland Museum of Natural History. The variables represented seven articular characteristics of the head of the first metatarsal, the length of first metatarsal, and the height and width of the base of the first proximal phalanx. Descriptive statistics for each of the variables are presented along with comparisons on gender and race. Strong differences comparing the means of the males and females were found; however, only minor differences were found between the blacks and whites. Correlation coefficients between all variables were found to be statistically significant; however, some relationships were more distinct than others. These data are presented as an aid in the accurate sizing of future prosthetic first metatarsophalangeal joint designs.

Necessary dorsiflexion of the first metatarsophalangeal joint during gait.

Previous studies of first metatarsophalangeal joint range of motion have resulted in varying values for dorsiflexion of this joint. These values reflect assisted dorsiflexion of the first metatarsophalangeal joint, which has been believed to be the same value that would be obtained during the toe-off phase of gait. These values range from 60 degrees to 90 degrees. This study attempts to obtain measurements during toe-off and to compare obtained values with those of assisted dorsiflexion from the previously mentioned studies.

Effects of fibrin sealant on the fixation of porous titanium and pyrolytic carbon implants.

The authors investigated the potential role the fibrin sealant system may portray in the fixation of osseous implants. The application of a layer of fibrin did not interfere with the fixation of osseous implants of either pyrolytic carbon or Biolite-coated porous titanium. A greater percentage of tissue ingrowth was observed in the porous titanium implants in the presence of the fibrin sealant system; however, no significant difference in the ultimate interfacial shear stress was observed.

Motion of the first metatarsophalangeal joint.

The analysis of motion of the first metatarsophalangeal joint in this study demonstrates the character of motion about this joint. Four instantaneous centers of rotation were calculated in the first metatarsal head that formed an arc encircling an area of increased stress patterns. The joint motion is made up of rolling, sliding, and compression. The fact that there is more than one center of motion contradicts the theory of a simple hinge joint. The joint is a dynamic acetabulum or "hammock," as described by Kelikian. That is, the first metatarsal head moves within a stable support comprised of the base of the proximal phalanx, the sesamoids, soft tissue, and muscle tendons. The nature of first metatarsophalangeal joint motion must be considered when contemplating surgical procedures of the first metatarsophalangeal joint.

Preliminary report on the use of liquid crystal thermography in podiatry.

The use of liquid crystal thermography as an adjuvant in the diagnosis and evaluation of podiatric problems is discussed. Liquid crystal thermography is a useful tool. However, similar to other methods of evaluation that are not diagnostic, specific needs must be weighed with the patient's other clinical and laboratory findings.

Austin bunionectomy: transpositional "V" osteotomy of the first metatarsal for hallux valgus.

The authors present results of their experiences with the Austin procedure in a group of patients approximately 24 months postoperatively. The overall patients' satisfaction rate was 96%. The overall clinical rating was 77%. Reasons for poor results were analyzed.

Pyrolytic carbon, porous implants, and the fibrin adhesive system.

The bone implant interface for Pyrolite and titanium alloy was evaluated. The effects of a fibrin adhesive system (FAS) on the interface was also compared. Fixation of the Pyrolite and porous titanium implants was observed to occur in the 4-week period of the study with minimal fibrous tissue encapsulation. The ultimate interfascial shear strength for bone-Pyrolite interface was attained at 4 weeks. No adverse effect with utilization of the FAS could be identified. Further investigation into the use of Pyrolite and the FAS in foot surgery is anticipated.

The use of intravenous regional anesthesia in podiatric surgery.

Several options become available when choosing between types of anesthesia in foot surgery. Ease in administration, minimal systemic effects, and rapid return of sensation make intravenous regional anesthesia an excellent option. The authors will discuss considerations and concepts along with their experiences with the procedure.

Cardiovascular disorders. Diagnostic and therapeutic implications for the podiatric medical practice.

The cardiovascular system has multiple implications in the podiatric patient. The examination should begin with a complete and careful history. The physical examination should be thorough. Noninvasive evaluation should be performed as indicated with both a static and functional component. Cardiac disease should be investigated in all patients with a history or physical findings consistent with this disorder, such as blue toe syndrome, palpitations, or chest pain.