Biomedical subjects
Publications and source records attributed to R A Vander Griend.
Juxta-epiphyseal fractures of the proximal phalanx are relatively common. A case report and literature review calls attention to the possibility of entrapment of either a flexor or extensor tendon in this type of fracture.
Thirty-nine patients who had a malignant or an aggressive benign bone tumor about the knee were managed with a resection arthrodesis with use of an intercalary allograft fixed with an intramedullary nail. In thirty-one patients, this was the method chosen for the initial reconstruction after resection of the tumor. In eight patients, another type of reconstruction had already failed. Both the proximal and the distal allograft-host junction healed and the functional outcome was satisfactory in thirty-two patients. Non-union developed in seven patients: at one junction in six patients and at both junctions in one. In five patients, the non-union healed after bone-grafting, repeat internal fixation, or replacement of the allograft. An above-the-knee amputation was done for two patients, both of whom had had a chronic non-union. One patient had a local recurrence, and it was treated with an above-the-knee amputation.
Osteosarcoma is the most common primary malignant tumor of bone. The variability of this tumor and its histologic variants in presentation, location, and biologic behavior has an influence on the prognosis and determines treatment options. Despite improvements in both survival and function due to limb salvage techniques and adjuvant chemotherapy, osteosarcoma continues to be a major challenge for the medical and surgical oncologist.
Both clinical and laboratory studies have shown that the chemotherapy drug, Methotrexate (MTX), has adverse short-term effects on bone. There are no studies that demonstrate the long-term response of bone to MTX. The purpose of this study was to determine the short- and long-term effects of MTX on bone volume, turnover, mineralization and strength. Three-month-old Sprague-Dawley rats were randomly assigned to a control (CTL) or MTX group and were given either daily MTX or saline injections for two separate 5-day courses (5 on/9 off/5 on). Fluorochrome compounds were injected prior to killing to label actively mineralizing bone surfaces. One CTL and MTX group were killed at 30, 80 and 170 days after treatment. Both femurs and tibiae were harvested for cancellous and cortical bone histomorphometry and biomechanical testing (torsion). Standard cancellous and cortical histomorphometric parameters were measured from undecalcified, methyl-methacrylate-embedded sections from the right proximal tibia and tibial and femoral diaphyses. The contralateral femur and tibia were torsionally loaded to failure and standard mechanical parameters were measured. All bone responses were statistically analyzed using a two-way ANOVA followed by Duncan's multiple comparison procedure (significance: p = 0.05). Cancellous bone volume was significantly lower in the MTX-treated group at 80 and 170 days. Cancellous mineralizing surface and longitudinal bone growth were significantly depressed at all time points yet mineral apposition rate was only depressed at the 170-day point. Cancellous osteoclast surface was increased at all time points for the MTX-treated animals.(ABSTRACT TRUNCATED AT 250 WORDS)
A simulated metatarsophalangeal joint arthrodesis was performed on 18 pairs of cadaveric great toes. One toe of each pair was fixed with a 4.0-mm oblique AO cancellous screw. The contralateral toe was fixed with one of three techniques: (1) a miniplate placed dorsally; (2) a 4.5-mm Herbert cannulated screw placed from the metatarsal neck into the medullary canal of the proximal phalanx; or (3) a 3/32-inch Steinmann pin placed longitudinally. An oblique 0.045 Kirschner wire was added with each method. The specimens were tested to failure in dorsiflexion. The miniplate was significantly stronger than the AO screw in force to failure and initial stiffness. The Herbert cannulated screw was also significantly stronger in force to failure than the AO screw. There was no significant strength difference between the Steinmann pin and the AO screw.
One hundred and twenty patients had an allograft reconstruction of the femur, tibia, or humerus. Of a total of 183 allograft-host junctions, eight-three were fixed with a plate; ninety-eight, with an intramedullary rod; and two, with screws alone. There was no significant difference between the rate of union after fixation with a plate and that after intramedullary fixation (p = 1.00). However, fixation with a plate was associated with a higher rate of fracture of the allograft (p < 0.0001). Some problem related to the internal fixation of the allograft was identified at eighteen of the twenty junctions that did not heal. There was a significant association (p < 0.001) between a problem in the achievement of stable fixation and the development of a non-union at the allograft-host junction.
Nine patients with nonunited humeral shaft fractures were treated by open reduction and internal fixation with an intramedullary fibular bone graft and a compression plate. Fixation of the screws was enhanced by passing them through the fibula as well as the two humeral cortices (quadricortical fixation). Eight of the nine fractures united at an average of 3.5 months. Tests on cadaver bones showed that quadricortical fixation was as strong as methylmethacrylate augmentation and significantly better than bicortical fixation.
We reviewed the results of the treatment of giant-cell tumors of the distal part of the radius in twenty-three patients, to identify criteria that could assist in the selection of the most effective option for treatment or reconstruction. The treatment was chosen on the basis of the preoperative roentgenographic assessment of the extent of the tumor. Seven patients, who had received previous treatment elsewhere, were referred to us because of a local recurrence. An extended curettage followed by packing of the cavity with cement was effective in preserving the normal function of the extremity and in eradicating the lesion in five patients who had a lesion that was intraosseous or that involved minimum cortical perforation. Of the eighteen remaining patients, who had extraosseous extension of the tumor, seventeen had a resection of the distal part of the radius and one had a below-the-elbow amputation. After resection of the involved segment of bone, the best functional result was seen in the patients who had been managed with a radiocarpal arthrodesis and use of an intercalary bone graft that was stabilized with a long plate. At the most recent follow-up examination (range, two to nineteen years after the curettage or resection), there had been no local recurrences.
Twenty-five patients who had an osteosarcoma of the pelvis were treated at the University of Florida between 1967 and 1990. Two of these patients had underlying Paget disease, and five had received previous radiation therapy to the pelvis. Common problems in this series of patients included delays and errors in establishment of the diagnosis, underestimation of the extent of the tumor on the radiographic staging studies, histopathological findings of local extension next to and into pelvic structures, widespread invasion into major pelvic veins, and microscopic foci of tumor in otherwise normal tissue. These problems led to difficulty in gaining local control of the tumor with any type of operative procedure. Of the eighteen patients who had a resection, only four had a contamination-free wide margin, and a local recurrence developed in thirteen. Only one patient, who had no evidence of disease eleven years after treatment, was alive at the time of writing. Because of the tendency for venous invasion, the radiographic staging studies should include a thorough evaluation of the blood vessels adjacent to the tumor.
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Orthopedic fixation devices are used in the treatment of fractures, soft-tissue injuries, and reconstructive surgery. After fracture reduction, internal, external, or intramedullary fixation devices may be used to provide stability and maintain the alignment of bone fragments during the healing process. They must be strong and secure enough to allow early mobilization of the injured part, as well as the entire patient. Compression is used whenever possible to increase the contact area and the stability between fragments and to decrease the stress on the implant. Screws are used primarily to provide interfragmental compression or to attach plates, which can then provide compression, prevent displacement, and support the fragments during healing. Pins and wires can be used for fixation of small fragments or fractures in small bones and for attachment of external fixation devices and traction. A basic understanding of the devices and principles of use is needed to interpret radiographs obtained after the treatment of musculoskeletal injuries.
The effect of local extent of the tumor on disease-free survival was studied in fifty-one patients who had an osteosarcoma, all of whom were treated according to the same protocol. Disease-free survival was defined as the interval between entry into the protocol and local recurrence, metastasis, or death (whichever occurred first). All patients had a Stage-IIB intramedullary osteosarcoma--that is, a high-grade malignant tumor (Stage II) with cortical penetration (B). The tumors were subdivided on the basis of the amount of local extension: E1--the tumor touches but does not elevate or penetrate the periosteum; E2--the tumor elevates but does not penetrate the periosteum; E3--the tumor penetrates into, but not through, the periosteum; E4--there is minimum extraperiosteal extension without invasion of another structure, such as a muscle, tendon, or ligament; E5--the tumor invades one additional structure (a muscle, ligament, or tendon); and E6--the tumor invades two or more structures adjacent to the bone. When the tumor had invaded two or more adjacent structures (E6), the instantaneous risk of failure was estimated to be 5.9 times greater than when the tumor had a lesser extent (E1 through E5). The relative prognostic importance of the amount of local extension, the size of the tumor, and the sex and age of the patient was compared with forward step-wise Cox multivariate analysis. Only the amount of local extension had a significant effect on disease-free survival. The estimated cumulative probabilities of disease-free survival at five years, according to the Kaplan-Meier method, were 49.1 +/- 8.5 per cent for patients who had a Stage-IIB tumor, 79.8 +/- 9.3 per cent for those who had a Stage-IIB but not E6 tumor, and 17.6 +/- 11.3 per cent for those who had a Stage-IIB E6 tumor. These data suggest that, with respect to prognosis, there are two distinct subgroups of Stage-IIB osteosarcomas that can be objectively defined by the amount of local extension.
Eleven patients with 12 three-part fractures of the proximal humerus were treated by open reduction and internal fixation using AO/ASIF buttress plating. All of the fractures healed. There were no failures of fixation. Nine of these patients returned for a follow up of more than 2 years and had a satisfactory rating using Neer's shoulder rating system. Five patients who had an acromioplasty at the time of their initial surgery had slightly better function and range of motion than the remaining patients. Successful operative treatment requires accurate definition of the fracture pattern, careful attention to the details of internal fixation, and supervised postoperative rehabilitation.
The goal in the treatment of vertical shear fractures of the pelvis is to achieve and maintain an accurate reduction of the displaced hemipelvis. Open reduction and internal fixation of the posterior pelvic ring injury along with either internal or external fixation of the anterior pelvic ring injury was used in 12 vertical shear fractures in 11 patients. The posterior fixation was aided by accurate definition of the injury pattern, use of preoperative traction, early surgical treatment, use of flexible instruments, and identification of the posterior sacral foramina, which were used as a guide to allow accurate screw placement into the sacrum and avoid nerve root injury. The procedure was not associated with an increased rate of infection or neural injury. In the ten patients followed more than 1 year there were no late displacements of the hemipelvis and all of the fractures healed.
In a retrospective review of 80 tibial plateau fractures, 28 fractures were treated nonoperatively with a variety of closed methods and 52 were treated with open reduction and internal fixation using AO technique. At an average follow up of 24 months, a satisfactory result was obtained in 87% of the operatively treated patients and in 66% of those treated nonoperatively. It appears that stable, minimally displaced fractures do equally well with closed or open treatment. Patients with depressed, displaced, or unstable fractures did better with operative treatment. When operative treatment is planned the principles and techniques of internal fixation should be carefully followed.
To improve intramedullary fixation with polymethylmethacrylate for use in pathologic bone, a new fixation system was developed. A fluted intramedullary rod was modified to allow injection of low-viscosity polymethylmethacrylate (PMMA) through the rod with retrograde filling of the void spaces between the rod and the medullary canal. This provided uniform distribution of the cement along the length of the rod and significantly improved fixation stability. Biomechanical testing using this system on simulated pathologic lesions of the femur showed a twofold increase in torsional strength over intramedullary methods previously used, with strength approaching that of the intact femur. In 16 patients, the device made mobilization possible immediately after the operation.
Eighteen acute humeral shaft fractures were managed with closed Kuntscher nailing. Six were pathologic fractures. Stability, pain relief, and evidence of early fracture healing were achieved. Twelve fractures were stabilized because of multiple trauma and/or inadequate closed reduction: 11 of these healed within 3 months, and only one delayed union occurred. The most frequent complication was a decreased range of motion in the shoulder, which improved with rehabilitation. Despite reports of high complication rates, we have found that intramedullary fixation of the humerus can be used in selected patients with good results.