Stress fractures associated with osteoarthritis of the knee. A report of three cases.
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Aged↗
Biomedical subjects
C H Rorabeck
Publications and source records attributed to C H Rorabeck.
Extensor mechanism complications following total knee arthroplasty.
Extensor mechanism complications following 281 knee arthroplasties that included patellar resurfacing, performed by two surgeons in one hospital over a 6-year period, were reviewed. The mean follow-up period was 42 months. There were 28 (10%) extensor mechanism complications: 3 quadriceps tendon ruptures, 5 patellar fractures, 4 patellar tendon ruptures, 11 recurring patellar subluxations, 4 cases of patellar pain, and 1 malrotated patella. Nine (3%) required further surgery. Surgical technique may have contributed to the tendon ruptures; patellar fractures occurred mainly in patients who had rheumatoid arthritis. Patients with patellar subluxation had abnormal preoperative valgus deformities of their knees and presented with this subluxation problem an average of 4 months after surgery, but it appeared to cause them less discomfort with time. Patellar resurfacing as part of a knee arthroplasty procedure is recommended but should be performed with care to the integrity and vasculature of the extensor mechanism.
Aged↗
Kinematic I and Oxford knee arthroplasty. A 5-8-year follow-up study.
Sixty-seven consecutive Oxford Meniscal total knee arthroplasties (TKAs) were compared prospectively with 66 Kinematic I TKAs. At follow-up examination an average of 5.5 (range, 5-8) years later, 20 (30%) of the Oxford Meniscal TKAs had been revised (nine due to aseptic loosenings, seven to aseptic loosening and patellofemoral syndrome, two to patellofemoral syndrome, one to meniscal bearing dislocation, and one to sepsis) and in 16% one or more of the remaining tibial components was radiographically at risk. Three (5%) Kinematic I TKAs had been reoperated upon (one for anterior dislocation, one for a loose patellar component, and one for sepsis) and no component was considered radiographically at risk. The remaining cases demonstrated good and excellent knee ratings (Oxford, 82 +/- 11; Kinematic I, 88 +/- 6; P less than .01; Hospital for Special Surgery). This study suggests that the results of Kinematic I TKA are superior to those of Oxford Meniscal TKA; that patellofemoral resurfacing is advisable; and that Kinematic I TKA yields 5-year data comparable to those of total hip arthroplasty.
Activities of Daily Living↗
Cancellous bone support for patellar resurfacing.
The purpose of this study was to determine the compressive resistance of the cancellous bone in nine fresh specimens of human patellae. Standardized radiographic assessment and subsequent osteotomies were performed on each specimen. Grid patterns based on patellar anatomy enabled topographic compression on a material test system (MTS) Model 835 Bionix Universal Testing Machine (MTS Corporation, Minneapolis, MN) using a 4-mm diameter indentor. It was demonstrated that sacrifice of the patellar subchondral bone removes with it the strong cancellous bone support and topographic strength patterns of the cancellous bone on the surface of a patellar osteotomy does not have a consistent pattern in relation to the intracondylar eminence. Consequently, placement of fixation pegs is not critical with respect to strength of bony support.
Adult↗
Stability of ten configurations of the Hoffmann external-fixation frame.
The rigidity, load to yield, and load to failure of ten configurations of the Hoffmann external fixator were investigated using a model of wooden pylons with a simulated fracture that consisted of either a reduced transverse cut or a ten-millimeter gap. The axial compressive, torsional, anterior-posterior bending, and medial-lateral bending characteristics of four forms of the single half-frame (half-pinned), four double half-frame, and two full-frame (transfixion-pinned) configurations were examined. Of the single half-frame configurations, a system with a second stacked connecting-rod proved to be superior; however, the system yielded at a mean axial compressive load of only 199 newtons and failed totally at 355 newtons. The delta frame (two rods connecting or triangulating two half-frames set at an angle of 45 degrees to one another) was as rigid as the quadrilateral full frame in axial compression; however, it exhibited low loads to yield and to failure, with means around 200 and 350 newtons, respectively. The use of only two pins in each pin-cluster did not significantly affect the performance of the delta frame. The two full-frame systems performed poorly in torsion and particularly poorly in anterior-posterior bending. The loads that caused a one-millimeter movement within the fracture gap in axial compression were notably low: for the stacked half-frames the load did not exceed a mean value of 174 newtons; for the double half-frame, 190 newtons; and for the quadrilateral frame, 412 newtons. We concluded that no frame had a good over-all performance with regard to rigidity.(ABSTRACT TRUNCATED AT 250 WORDS)
Biomechanical Phenomena↗
A biomechanical study of wire fixation.
A biomechanical study of wire fixation was performed using 18-gauge stainless steel wire on an Instron universal testing machine. Six groups of wires were tested--an intact piece of wire (control), a wire bent to a right angle five times, a simple knot, a square knot, a loop knot and a twist knot. The tensile load-to-failure value for each wire was recorded. The intact wire broke at a mean load of 67 kg. The wires with the bend, the simple knot and the square knot all broke at similar loads. Those wires with a knot broke at the knot. The loop and the twist knots pulled apart at much lower loads. These results indicate that bending the wire does not weaken it substantially, but kinking may initiate the site of breakage. The square knot is the strongest knot; the loop and twist knots are not recommended if the wire is to be under tension.
Animals↗
Tibialis anterior muscle hernia: a rationale for treatment.
Tibialis anterior muscle hernia is an orthopedic problem that should be dealt with carefully since the potential complications of treatment are serious. The literature is reviewed to provide a better understanding of the natural history, incidence, classification and treatment of muscle hernias. Guidelines are proposed for a rational treatment plan for tibialis anterior muscle hernias. Asymptomatic hernias need no treatment. Longitudinal fasciotomies are recommended as the treatment of choice in symptomatic tibialis anterior muscle hernias that are refractory to conservative treatment.
Hernia↗
Distal humeral fractures in the adult.
Distal humeral fractures in the adult often are complicated by pseudarthrosis, pain, and limitation of motion. Of 29 adult patients with distal humeral fractures treated in teaching hospitals, 22 obtained acceptable results. Twenty-two percent of those treated by open methods and 36% of those treated by closed methods had unacceptable results. Ninety percent of the patients starting physiotherapy within six weeks of injury recovered well, while over half of those starting physiotherapy after six weeks had unsatisfactory results. Even comminuted fractures healed when treated by internal fixation and started early on exercises. The most important indicator of end result was the starting time of physiotherapy. Rigid internal fixation is recommended for this fracture, but if stability is not likely to be accomplished by open reduction, nonoperative measures are preferable.
Activities of Daily Living↗
Exertional tibialis posterior compartment syndrome.
Preexercise, exercise, and postexercise pressure measurements were performed simultaneously in the tibialis posterior muscle and the deep posterior compartment, to establish a diagnosis of exertional tibialis posterior compartment syndrome. The tibialis posterior muscle occupies its own fascial compartment and therefore should be decompressed at the time of deep posterior compartment fasciotomy.
Catheterization↗
Compartment syndrome as a complication of repair of a hernia of the tibialis anterior. A case report.
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Adult↗
A technique of posterior cervical fusion for instability of the cervical spine.
A technique of posterior cervical spine fusion (the "Dewar procedure") that allows immediate stabilization of the spine requiring only minimal external support is described. The procedure was performed in 16 patients with unstable fractures or fracture-dislocations of the cervical spine. All patients went on to develop solid fusion. Twelve patients incurred neurologic deficit due to their injury, and those with root involvement all recovered following fusion. Patients rendered quadriplegic as a result of their accident did not show any useful neurologic recovery but were able to start rehabilitation earlier and avoid the complications of nonoperative treatment. There were no significant complications related to surgery.
Adolescent↗
The effect of endoprosthetic mismatch and metal- or non-metal-backed acetabular components on in vitro pelvic stresses.
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Acetabulum↗
The pressure distribution under tourniquets.
We measured the detailed pressure distribution under pneumatic tourniquets and Esmarch bandages in canine limbs. The results showed that pressure concentration can occur in the tissue under the tourniquet. The Esmarch-bandage tourniquet was shown to be capable of producing pressures in excess of 1000 millimeters of mercury immediately beneath the tourniquet. There is a wide variation between cuff pressure and the pressures in the underlying tissues.
Animals↗
Indentation stiffness of the cancellous bone in the distal human tibia.
Total ankle arthroplasties tend to fail mainly on the tibial side. Fifteen fresh amputation specimens were used for assessment of the stiffness of the cancellous bone in the distal tibia. Because all current ankle replacements sacrifice the subchondral bone plate, the change in stiffness of cancellous bone was studied in transverse sections taken proximal to the subchondral plate of the ankle. The articular cartilage was removed from the tibial plafond, and serial 1-cm sections were taken, radiographed, and tested in compression on an Instron 1125 Universal Testing machine with the use of a 4-mm-diameter indentor. In the distal tibia, it was found that subchondral bone has an elastic modulus on the order of 300-450 MPa; removal of the subchondral bone plate reveals bone with a compressive resistance that is 30%-50% lower than with the bone plate intact; there is virtually no resistance to compression in the trabecular bone at a distance of more than 3 cm proximal to the subchondral bone plate; and stiffness characteristics in the distal tibia parallel the radiographic appearance of the trabeculae. The strongest cancellous bone in the region of the distal tibia is that near the subchondral bone plate. This material should be preserved, if possible, in the surgery for total ankle implants.
Biomechanical Phenomena↗
Computed tomography in pelvic liposarcoma: a case report.
A case of well-differentiated pelvic liposarcoma with unusual presentation of low-back pain and sciatica, due to the herniation through the greater sciatic notch, is described. Computed tomography is invaluable, not only in predicting the histologic diagnosis, but also in outlining the location, extent, and size of the tumor. This allows accurate planning of the surgical approach.
Back Pain↗
Infra-isthmal fractures of the femur: a review of 82 cases.
Eighty-two infra-isthmal fractures of the femur were reviewed in order to develop a fracture classification, to determine the results of treatment, and to define the best treatment methods for certain specific fracture patterns. Type I (transverse or short oblique) fractures were seen in 36 patients (mean age, 33 years). They had a 25% complication rate when treated by open reduction, and a high malunion rate when treated by closed means. Type II (spiral or long oblique) fractures were generally caused by falls, and were seen in 36 patients (mean age, 56 years). Most patients treated by operation had an unsatisfactory result. Malunion was seen in 29% of the patients treated by closed means. The remaining ten patients had either severely comminuted (Type III), or pathological (Type IV) fractures. Intramedullary nail fixation should be used wherever possible in these fractures since many of the complications in the operative group were related to rigid plate fixation. Closed treatment resulted in an unacceptably high incidence of malunion in this study, particularly in Type I fractures. Conventional methods of internal fixation were not successful in dealing with Type II fracture, and alternative methods are proposed.
Adolescent↗
The treatment of compartment syndromes of the leg.
Eighteen patients with acute compartment syndromes below the knee were treated with four-compartment fasciotomies using the double-incision technique. Pre-operative tissue pressure measurements ranged from 28 to 47 mmHg. If fasciotomy was performed within 24 hours of the onset of clinical symptoms and signs, a good result was almost always achieved. It is recommended that tibial fractures complicated with a compartment syndrome should be treated with some form of operative stabilisation of the fracture at the time of surgical fasciotomies.
Acute Disease↗
A six-year follow-up of infected total hip replacements managed by Girdlestone's arthroplasty.
Thirty-three Girdlestone's arthroplasties used to salvage infected total hip replacements were followed for a mean of 6.2 years to assess the efficacy of this procedure. Subjective and objective assessment was obtained at the time of review. Gram-negative organisms, retained cement, bony sequestra and secondary healing were common features of the five patients (15%) whose wounds discharged for more than four weeks after operation. Girdlestone's arthroplasty provided satisfactory pain relief in 91% of patients, and control of infection in 97%. Although leg-length discrepancy (mean 4 cm) and a Trendelenburg gait made walking difficult and tiring , 42% were satisfied with their functional ability; 85% needed walking aids, and 3 patients could not walk at all and were confined to bed or a chair. Overall, 79% were satisfied. Objectively, the mean Harris hip rating was 60; however, if patients with multiple joint problems were excluded, this score increased to 77. Girdlestone's arthroplasty seems a reasonable salvage procedure in the management of an infected total hip replacement and the results seem to improve with time.
Adult↗