[Primary and re-arthroplasty of the hip or knee joints in patients 80 years of age and older].

Due to the ageing of the population, more and more patients older than 80 years are in need of the hip and knee joints total endoprosthesis. The aim of this retrospective study was to describe perioperative mortality and frequency of complications associated with both primary and re-arthroplasty of hip and knee joints in this age group. For more information about demography, the perioperational period and frequency of complications were investigated 59 patient's card, who have had a 71 endoprosthesis operations, carried out by one surgeon. Information on mortality was obtained by means of telephone interviewing. The average level of mortality within 30 days, 1 year and 5 years amounted to 2.0, 6.1 and 10.2% respectively. Compared with other studies conducted over the past 20 years, these results reflect a significant reduction in the mortality, rate. Average frequency of complications in our study was to 52.2%. which corresponds to the previously published data. All the complications were eliminated and did not cause permanent disability. Thanks to the development of anaesthesia, surgical techniques and technologies, joint endoprosthetics can be considered safe in patients older than 80 years.

The patella in total knee arthroplasty.

Controversy persists as to whether the patella should be resurfaced in total knee arthroplasty. Can the good results of patellar cartilage against the metal femoral component be expected to endure? Attention to technique can be expected to reduce some of the complications of resurfacing, notably fracture, rupture, and instability. Component breakage results from metal-backed designs, and the causes of patellar clunks have not been fully understood.

Outcome of infected total knee utilizing a staging system for prosthetic joint infection.

This study reviews, over a 5-year period, the records of 70 consecutive patients with prosthetic knee infection and evaluates outcomes as a function of a staging system for prosthetic joint infection. The staging system for prosthetic joint infection was divided into three main categories that include infection type, systemic host grade, and local extremity grade. Outcome indices analyzed included Knee Society Score (KSS), complication rate, amputation rate, and rate of permanent resection. We show that categorizing and stratifying data for patients with infected total knee arthroplasty are useful. A universally accepted staging system would allow for more objective comparisons of treatments and may eventually define particular treatment regimens for particular classes of patients.

In vitro elution of tobramycin and vancomycin polymethylmethacrylate beads and spacers from Simplex and Palacos.

In vitro studies of antibiotic elution from polymethylmethacrylate cement comparing Simplex (Howmedica, Rutherford, NJ) with Palacos brands (Richards, Memphis, TN) have shown variable results. This study compares the elution of tobramycin and vancomycin from Simplex and Palacos beads and spacers. Six-millimeter beads and spacers were incubated in phosphate-buffered saline, and the solution was sampled and changed daily until the concentration of antibiotic fell below the minimum inhibitory concentration (MIC) for Staphylococcus aureus. In all groups, the Palacos PMMA beads and spacers showed elution at higher levels and remained above the MIC longer than did the Simplex PMMA beads. Tobramycin had superior elution to vancomycin in all groups. This in vitro study shows that Palacos PMMA has superior elution properties to Simplex PMMA in tobramycin and vancomycin beads and spacers.

Relation of surface area to in vitro elution characteristics of vancomycin-impregnated polymethylmethacrylate spacers.

To study the relationship between surface area and antibiotic elution from antibiotic-impregnated polymethylmethacrylate (PMMA) spacers, a standard block spacer made of vancomycin (4 g) and 40 g of PMMA was compared with two unique spacer designs, the "donut" and "fenestrated." The spacers were incubated in phosphate-buffered saline, which was changed daily, and a microbiologic assay was used to measure the antibiotic activity of the eluates. The donut and fenestrated spacers had 12% and 40% more surface area than the standard spacer, respectively. There was no significant difference, however, in daily elution levels of antibiotic between the donut spacer and the standard spacer. The fenestrated spacer displayed significantly better elution than either the standard or donut spacers, with an average of 20% more antibiotic eluted on any given day.

Breakage of a Total Condylar III knee prosthesis. A case report.

The authors report the failure of a Total Condylar III (Cintor, Johnson and Johnson, Raynham, MA) knee arthroplasty, implanted in a second revision knee surgery, due to fracture of the tibial spine. The tibial component was in varus position and externally rotated relative to the tibia. This imparted torque and resulted in a spiral fracture of the polyethylene spine. This is the first report of failure of a Total Condylar III prosthesis by mechanical breakage.

Rehabilitation after total knee arthroplasty: a comparison of 2 rehabilitation techniques.

This study was conducted to compare postoperative total knee arthroplasty rehabilitation protocols. The hypothesis of this study was that patients undergoing total knee arthroplasty could achieve range of motion and hospital discharge in the same period using a postoperative rehabilitation protocol that did not use a continuous passive motion machine. This randomized prospective study compared 46 total knee arthroplasties in which a continuous passive motion machine was used with 37 total knees that were rehabilitated with early passive flexion of the knee (named drop and dangle protocol). Postoperative physical therapy regimens were otherwise the same for both groups. Surgical technique was the same for both groups except for closure which was performed in the drop and dangle group with the knee at 90 degrees to 95 degrees flexion. Only patients with osteoarthritis were included in the study, and in both groups of patients received the same prosthetic components. Patients in the drop and dangle group were discharged from the hospital 1 day earlier (p = 0.01) and had a statistically better extension range of 2.8 degrees at 6 months (p = 0.03). Knees in the drop and dangle group had less drainage (p = 0.06). Range of motion and hospital discharge can be achieved in a similar time interval with the drop and dangle technique as with using a continuous passive motion device, and that such a device is not required for postoperative knee rehabilitation.

Contemporary total hip replacement with metal on metal articulation.

Between 1991 and 1994, 74 patients received total hip replacements with metal on metal articulation. The results of these patients with 74 hips who had a 6-month to 4-year (average, 2.2 years average) followup are reported. Patients were prospectively evaluated by the Harris hip score, a patient self assessment form, and radiographs. The average postoperative Harris hip score was 91. Patient self assessment forms showed that 95% of the patients scored their results as excellent or good. No patient had revision for loosening, but 1 underwent revision surgery for recurrent dislocation. Serial radiographs have not revealed loosening or osteolysis. Wear could not be measured radiographically. Twenty-seven of the patients had bilateral total hip replacements with 1 hip being metal on polyethylene; the patients could not detect any difference between the 2 hips. The satisfactory short term results from the contemporary metal on metal articulation investigated in this study are encouraging and warrant continued study.

Medialization of the patella in total knee arthroplasty.

Patellar complications of total knee arthroplasty remain the most common cause of pain and reoperation. Laboratory studies have suggested that medialization of the patella will improve tracking of the patella on the trochlea of the femoral component. The purpose of this study was to determine if clinical medialization of the patellar component on the patellar bone would improve tracking of the patella as demonstrated radiographically. Sixty-two knees were randomized so that 31 knees had a centrally placed patellar component and 31 had the patellar component placed on the medial two thirds of the patellar bone. There was no difference between the two groups with respect to either clinical or radiographic results in the first year after surgery. There was no improvement compared with previous reports in the incidence of tilt and displacement. The one improvement was a reduction in the incidence of lateral release. Thus, consequences of lateral release such as postoperative morbidity, avascular necrosis of the patella, and stress fracture of the patella can be avoided. It is recommended that the patellar component be placed on the medial two thirds of the patella to reduce the occurrence of lateral release. Tracking of the patella during surgery can be assessed using a single suture placed at the superior pole of the patella, and this technique in combination with the no-thumbs test provides an additional means of evaluation for patellar tracking.

Anthropometric study of normal glenohumeral relationships.

Ninety-three cadaveric proximal humeri and matching scapulae with no evidence of shoulder disease were obtained. High-resolution roentgenograms were made. They were the digitized, and a custom computer program was used to obtain periosteal and endosteal dimensions (humeral canal width, shaft width, tuberosity offset, head offset, radius of curvature, head diameter, canal flare index, glenoid height and depth, arc of enclosure, radius of curvature, and depth of cancellous bone, among others). Statistical analyses included correlations among pairs of dimensions, regression analysis, and confidence intervals to estimate each geometric parameter. To represent the degree of conformity and constraint between the humeral head and glenoid, a conformity index (radius of head/radius glenoid) and constraint index (arc of enclosure/360) were calculated for each shoulder. Most of the parameters measured approximated a Gaussian distribution. Pairwise correlations of the geometric parameters showed that many were significantly associated at the 5% level (p < 0.05) with a high correlation coefficient (r > 0.4), meaning that the variations between the parameters were not purely random but rather they were related and that this relationship was useful in a predictive sense. With these key parameters identified, one can design components with an optimum fit or match an existing design to a patient's anatomy with a high degree of accuracy. No correlation was found between the radii of curvature for the humeral head and glenoid in either the coronal or sagittal plane or between the humeral head diameter and arc of enclosure. The mean conformity index was 0.72 in the coronal and 0.63 in the sagittal plane. Only 16% of the specimens had a conformity index greater than 0.9, indicating the radii of curvature matched. The vast majority had a more curved humeral head and flatter glenoid. Also, there was more constraint to the glenoid in the coronal versus sagittal plane (constraint index = 0.18 vs 0.13). These anatomic features help prevent superior-inferior translation of the humeral head but allow translation in the sagittal plane. This database of basic anatomic geometry defines the anatomic relationships of the proximal humerus and glenoid cavity that allow for a precise bone-implant fit and assesses the match between the shape of existing components and the patient's anatomy.

Natural history of uncorrected flexion contractures following total knee arthroplasty.

Over a 2-year period, 29 patients were identified that had preoperative flexion contractures less than 30 degrees and were not fully corrected to neutral following total knee arthroplasty. They were followed after surgery at 3, 6, and 12 months, and yearly thereafter with complete clinical and roentgenographic examinations to determine the natural history of the flexion contracture and its effect on the clinical outcome. The mean age of the 10 women and 19 men was 66 years (range, 47-80 years). The mean preoperative flexion contracture was 11 degrees (range, 5 degrees-30 degrees). The mean follow-up period was 33 months (range, 24-60 months). The mean values of the flexion contractures at each follow-up period were; immediately after surgery, 10.5 degrees; at 3 months, 5 degrees; at 6 months, 2 degrees; at 12 months, 1 degree; and at 24 months, 1 degree (P < .0001). Resolution of the flexion contracture did not vary between patients under and over the age of 65 years. There was no statistically significant difference in the residual flexion contracture when knees with preoperative contractures from 0 degrees to 14 degrees and 15 degrees to 30 degrees were compared. The clinical outcome was not affected by the residual flexion contracture after 6 months of follow-up evaluations. Significant improvements can occur after surgery with rehabilitation, and it appears that complete intraoperative correction is not necessary. There appears to be no difference in the natural history of flexion contractures with regard to age or severity up to 30 degrees.

Hydroxyapatite-coated proximal ingrowth femoral stems. A matched pair control study.

A matched pair study of 2 groups of 42 uncemented total hip replacements were compared retrospectively after a minimum 3-year followup. Forty-two hips were implanted with a hydroxyapatite coating on the proximal femoral patched porous surfaces; 42 hips had patched porous-coated stems without hydroxyapatite. There were no clinical differences between the matched groups by any criteria of measurement. There was no statistically significant difference between the matched groups for femoral stem fixation at all followup intervals. At the 3-year followup, 90% of the femoral stems in the hydroxyapatite porous group, and 83% in the porous control group achieved stable bony fixation. Hydroxyapatite-coated femoral stems demonstrated accelerated bone remodeling characterized by proximal cancellous hypertrophy. The percentage of femoral stems exhibiting cancellous hypertrophy was significantly greater at all followup intervals. This study did not demonstrate any clinical advantage of hydroxyapatite being added to a porous-coated surface. The radiographic changes of bone remodeling seen with hydroxyapatite are not known to improve durability of the hip arthroplasty. This study again condemns the use of patched porous-coating and titanium-bearing surfaces.

Closed reduction of dislocated total hip with S-ROM constrained acetabular component.

One of the major disadvantages reported for the use of the S-ROM constrained total hip arthroplasty is the need for mandatory urgent revision surgery in cases of dislocation. In patients who are medically compromised and poor surgical candidates, this disadvantage presents a difficult management dilemma. To address this problem, we have developed a technique for closed reduction of dislocated S-ROM constrained hips. This technique has been used successfully on 3 patients, all of whom were medically compromised and poor surgical candidates. All patients tolerated the procedure well, and all went on to revision total hip arthroplasty on an elective basis after medical optimization.

Muscle flaps in total knee arthroplasty.

The results of 12 patients who had been treated with muscle flap coverage for compromised soft tissues associated with total knee arthroplasty were studied. Five latissimus dorsi free flaps, 6 medial gastrocnemius rotational flaps, and 2 rectus abdominis free flaps were done in 12 knees. The authors used and classified 3 types of muscle flaps: (1) prophylactic soft tissue coverage, done before definitive reconstruction; (2) treating muscle flap for infected prostheses with deficient soft tissue coverage; and (3) salvage muscle flap for wound dehiscence or necrosis in the immediate postoperative period. These patients were observed for an average of 4.1 years (range, 1-8 years). The wound was revascularized successfully in 100% of the knees. The prosthesis was preserved in 83% of the knees. Recurrent infection occurred in 3 patients. Treating muscle flaps are least likely to result in an overall successful reconstruction because these flaps are used in knees with chronic infection. Prophylactic flaps and salvage muscle flaps provide the soft tissue coverage necessary to allow successful reconstruction in the appropriate circumstances.

Infected total knee arthroplasty. Two-stage reimplantation with a gastrocnemius rotational flap.

This study reviews a consecutive series of 21 patients undergoing two-stage reimplantation total knee arthroplasty for late chronic infection. All 21 patients had late chronic infections, and 20 of 21 patients were compromised hosts. Seven different organisms were isolated at the time of prosthetic resection. Staphylococcus coagulase negative species was the most frequently isolated organism. At the time of reimplantation, a medial gastrocnemius rotational flap was rotated over the proximal tibia and knee for wound closure. The average explantation time was 25 weeks (range, 7-76 weeks), and no methylmethacrylate spacers were used. At an average 17-month followup (range, 5.1-33.1 months) all reimplanted total knee replacements remained in place with one patient having recurrent infection. At reimplantation, 11 patients had positive bacterial cultures from tissue specimens. Sixteen of the 33 (40%) positive cultures were from specimens taken from the medullary canal. At followup, the average Knee Society Score was 77.4 (range, 40-100). The lack of a methylmethacrylate spacer and a long explantation time were considered important factors in diminishing functional performance and determining the need for a gastrocnemius flap. A medial gastrocnemius rotational flap should be considered at the time of reimplantation total knee arthroplasty if the soft tissue envelope about the knee is compromised and cannot be closed without undue tension.