Prosthetic Knee Arthroplasty Research Articles

Aspergillus fumigatus infection as a delayed manifestation of prosthetic knee arthroplasty and a review of the literature

Fungal infection after total joint arthroplasty is a very rare but serious complication and a challenge to the treating and consulting physicians. The literature includes little information about the treatment protocol for Aspergillus infection after total knee arthroplasty, since only 3 cases have been reported. We describe the case of a non-immunocompromised patient who lacked predisposing risk factors and presented with pain and swelling. An aspiration under sterile conditions revealed Aspergillus fumigatus. The patient was treated successfully with a 2-stage exchange reimplantation and 6-week course of liposomal amphotericin B. At 4 y after reimplantation, the patient had no evidence of infection or pain.

The Inside-Out Minimally Invasive High Tibial Osteotomy Technique (SS-50)

The Inside-Out Minimally Invasive High Tibial Osteotomy Technique (SS-50)

Walking ability following knee arthroplasty: A prospective pilot study of factors affecting the maximal walking distance in 18 patients before and 6 months after total knee arthroplasty

Functional assessment of patients before and after prosthetic knee arthroplasty is based on clinical examination, which is usually summarized in various knee scores. The present study proposes a different and more subject orientated assessment for functional grading of these patients by measuring their maximal distance of walking ability, which is not apparent from the conventional outcome scores. Eighteen consecutive patients with knee osteoarthritis were evaluated for their knee and knee functional scores (The Knee Society clinical rating system) and for the maximal distance of their walking ability before and 6 months after knee arthroplasty. Specially designed walking ability grading was used for evaluation of walking on walkway. The pre- and post-operative knee scores and maximal walking distance and grading were statistically compared. A significant improvement in the knee and functional scores following surgery was observed. But the maximal walking ability grades and distances did not change significantly following surgery, showing a high relation between pre- and post-operative values. The limitation in post-operative walking was due to the revealed additional health disabilities, not related to the affected knee. Therefore we suggest that pre-operative evaluation of walking abilities should be taken into consideration both for patients' selection and timing of surgery and also for matching of patients' expectation from outcome of prosthetic knee arthroplasty.

The Early Innovators of Today's Resurfacing Condylar Knees

The 1970s saw an explosion of ideas in the field of prosthetic knee arthroplasty. This paper is an effort to identify the innovators who contributed to the development of today's condylar total knee prostheses and the surgical techniques used to insert them. The 1970s were selected because most innovations occurred during those years. Two different design approaches were undertaken simultaneously. One was a functional approach whereas the other was a strictly anatomical approach. Initially, these 2 approaches led to very different designs. But the common goal of recreating human knee function eventually led to more similarities than differences. The author describes how, when, and why these dedicated individuals came to their ideas. The work is largely based on interviews and correspondence with those involved as well as on reviews of patents and papers pertaining to their work.

Correction of fixed contractures during total knee arthroplasty in haemophiliacs.

Encouraging clinical experience has increased the indications for prosthetic knee arthroplasty in haemophiliacs. The medical status, physical disability, age and projected activity levels are the major factors in determining treatment for the patient with unilateral or bilateral haemophilic arthropathy of the knee. In more severely involved knees of patients with haemophilia, flexion contracture is a common deformity. In addition, valgus, external rotation deformity and posterior subluxation of the tibia may exist. The surgeon must have the expertise and experience to correct these deformities sufficiently when performing a total knee arthroplasty. A properly performed soft-tissue release which achieves balance between the medial and lateral ligamentous structures and posterior capsule can provide stability to the knee with a semiconstrained prosthesis. In cases with severe deformity requiring resection of the posterior cruciate ligament a posterior cruciate substituting prosthesis may be necessary.

Supracondylar Fracture of the Femur Following Prosthetic Knee Arthroplasty

Sixty-one supracondylar fractures above prosthetic knee replacements in 58 patients were reviewed with a mean follow-up time of 3.7 years (range, 9 months to ten years). The mean interim between arthroplasty and fracture was 2.9 years (range, intraoperative to ten years). Twenty-seven cases demonstrated notching of the anterior femoral cortex. Seventeen patients suffered from a severe neurologic disorder. Group A consisted of 30 patients with 31 fractures treated by open reduction and internal fixation or revision arthroplasty. Follow-up study revealed 25 unions, three malunions, one nonunion, and two above-knee amputations for deep sepsis. Four of 31 patients had increased pain levels or change in ambulatory status postoperatively. Group B consisted of 30 fractures in 28 patients treated by casting alone or traction followed by cast bracing. Follow-up examination showed 17 unions, seven malunions, and six nonunions. Fifteen of the 30 patients had increased pain levels or change in ambulatory status after treatment. Casting produced significant decreases in motion in both groups. The results indicate that this fracture is associated with anterior notching of the femoral cortex and preexisting neurologic disorders. Patients with a supracondylar fracture following prosthetic knee arthroplasty are best managed by secure internal fixation and early motion.

The Effect of Early Weight-bearing in Total Knee Arthroplasty

Patients undergoing bilateral simultaneous total knee arthroplasty experienced early supported-weight-bearing on both knees. They were compared with two similar groups of patients whose postoperative weight-bearing on the operated extremity was markedly restricted. The clinical results and incidence of complications were similar in the three groups. There were no significant differences in the incidence of radiolucent lines at follow-up examination two to five years later. Bilateral simultaneous total knee arthroplasty is an effective and safe method of managing patients with arthritic knees where both require replacement. Early supported bilateral weight-bearing does not appear to have any deleterious effects on the bone-cement interface that can be detected on clinical or radiographic analysis. However, all patients should not be considered for bilateral prosthetic knee arthroplasty simply because they have arthritic changes in both knees and the procedure is efficacious. Frequently, only one knee is significantly painful or deformed, and its correction may relieve the opposite knee for an extended period. Bilateral operations are indicated when the pain and deformity of an unoperated knee will significantly retard the reconstructed knee, as in severe flexion contractures or malalignment.

Metal Concentration in Synovial Fluids of Patients with Prosthetic Knee Arthroplasty

Significant levels of the major components of metal prostheses in total knee arthroplasty were measured in the synovial fluids from patients with these implants. Cobalt (Co), Chromium (Cr), and Nickel (Ni) concentrations were determined by atomic absorption spectrophotometry on 26 synovial fluid samples from 18 patients with hinged (metal-on-metal) prostheses and eight patients with nonhinged (metal-on-polyethylene) prostheses. Concentrations of Co, Cr, and Ni were significantly higher in synovial fluids from hinged knees, as were Ni concentrations in fluids from nonhinged knees. Of the three metals, Ni showed some evidence of increases solubility. The metal debris did not appear to provoke a leukocyte response, insofar as surprisingly low numbers of neutrophils were present in these fluids, all of which were obtained from nonseptic knees. However, significant numbers of lymphocytes and large mononuclear cells were present in the fluids.

Duopatellar Total Knee Replacement: The Brigham Experience

Over the past 25 years at the Brigham Hospital we have seen prosthetic knee arthroplasty evolve from metal interpositional hemi-arthroplasty to the current generation of metal-to-plastic total knee replacements. Surely this evolutionary process will continue for may more years. Time will help us answer many of the questions and controversies that exist regarding posterior cruciate retention, patellar resurfacing, and unicompartmental replacement. We have yet to establish the optimal tibial stem length and shape and whether metal backing is truely beneficial. It is still to be determined whether the standard condylar femoral component should have condylar lugs to enhance fixation or an intramedullary stem with no condylar lugs. In the meantime, we have the use of a graduated system of prostheses that can be tailored to the individual needs of each patient and can predictably relieve pain and improve function in well over 90 per cent of cases. Late complications requiring revision surgery (most often patellar problems or tibial loosening) are occurring at a rate of 1 per cent per year of follow-up, and we hope these will be minimized by the recent advances we have discussed.

Ipsilateral Supracondylar Femur Fractures Following Knee Arthroplasty

A retrospective study was performed to evaluate the treatment of five patients with prosthetic knee arthroplasty who sustained a supracondylar femoral fracture of the ipsilateral side. Four of the patients were initially treated by plaster immobilization or traction. Two of the four showed no signs of healing at three months postfracture and had to have open reduction and internal fixation. The fifth patient had primary open reduction and internal fixation. The three patients who were treated surgically regained their prefracture knee rating score. The two who were treated nonoperatively for their fracture had a significant loss in limb function and failed to regain their prefracture knee rating score. Open reduction and internal fixation of these fractures achieves the best results despite the complicating factors of in situ prosthetic components.

ICLH Replacement of the Knee

Investigations which began in 1968 have culminated in a knee arthroplasty which can now be confidently used to treat most patients with arthritic knee deformities. Our earlier studies showed that a prosthetic knee arthroplasty must be reliably aligned and stabilized in extension, that patellar pain and polyethelene wear were significant potential problems and that loosening and sinkage of the tibial component must be avoided. Our present knee prosthesis and instrumentation if properly used should avoid these pitfalls. Beginning in January 1977 we performed 84 knee arthroplasties utilizing the present design. A series of 79 knees has been available for our computer-assisted review; 46 patients had a diagnosis of inflammatory arthritis and 29 had primary osteoarthrosis: 22 knees had been previously operated upon. Although all femoral components were fixed with polymethylmethacrylate, the tibial components were completely cemented in 21 knees, partially cemented in 20, and no cement was used in 38 cases. In these latter knees special pegs provided a mechanical interlock with the tibia for fixation. Thirty-six patellae were replaced, of which 11 were fixed with a similar interlocking peg. The arthroplasties failed in 8 patients. Of the remainder, 90% of knees had acceptable pain relief and all but 4 patients were able to walk outdoors. Flexion to 90 degrees or more was achieved in 85% of the knees. Only 2 patients had unacceptable alignment. To date we feel that with the use of this improved prosthesis, in conjunction with the instruments which allow proper placement of the prosthesis, the majority of arthritic knees can be successfully corrected. However, further careful long-term follow-up studies must continue.