Managing bone loss with augmentation.

Augmentation blocks are effective ways of treating the problem of bone loss on the distal and posterior femur. They allow accurate and durable reestablishment of the distal and posterior joint line in revision total knee replacements. They are particularly appropriate in revisions being carried out in elderly, osteopenic patients with severe deformities or instabilities. Revision instrumentation can and should philosophically and mechanically remind one of and be consistent with primary total knee instrumentation.

Safety and efficacy of bilateral total knee arthroplasty.

Recent studies have reported increased morbidity associated with bilateral simultaneous total knee arthroplasty (TKA). The purpose of this study was to evaluate the morbidity and clinical outcome associated with simultaneous bilateral TKA in contrast to unilateral TKA. All primary TKAs, either unilateral or simultaneous bilateral, performed between May 1988 and July 1993 were retrospectively reviewed. Patients were evaluated using Knee Society scores both before surgery and a minimum of 6 months after surgery. In addition to routine demographics, patients were evaluated for the incidence of both local wound and systemic complications. It is concluded that performing simultaneous bilateral TKA does not result in any significant increase in patient morbidity or compromise in postoperative function when compared with unilateral TKA.

Artroplastia unicompartimental do joelho: experiência após 22 casos / Unicompartmental knee arthroplasty: experience after 22 cases

Os autores apresentam 22 casos de artroplastia unicompartimental do joelho operados pelo grupo de joelho do INTO-HTO-RJ, no período compreendido entre fevereiro/90 e agosto/96, com seguimento médio de 56,70 meses; dois casos foram excluídos: um por näo acompanhar o protocolo de revisöes e o outro por ter-se extraviado o prontuário. Do total de pacientes operados, cinco casos evoluíram com resultado insatisfatório, necessitando conversäo para artroplastia total do joelho, sendo dois casos de osteonecrose e três de osteoartrose. Os resultados nos demais pacientes da série foram considerados como excelentes do ponto de vista clínico e radiológico. Concluem os autores que os resultados säo animadores, devendo ser considerada como boa opçÒo terapêutica no tratamento da patologia degenerativa monocompartimental do joelho.

Comparison of the results of bilateral total knee arthroplasty with and without patellar replacement for rheumatoid arthritis. A follow-up note.

Simultaneous bilateral total knee arthroplasty was performed in twenty-six patients who had rheumatoid arthritis, and a patellar replacement was performed concurrently in one randomly selected knee in each patient. A lateral retinacular release was performed in all knees. The patients were followed for at least six years (mean, 6.6 years; range, 6.0 to 7.5 years), and the postoperative status of the patients was evaluated with the knee score of The Hospital for Special Surgery. Pain on standing and on ascending or descending stairs as well as tenderness of the patellofemoral joint also were assessed. The over-all score and the individual scores for pain, function, range of motion, muscle strength, flexion contracture, and instability were not significantly different between the knees that had had a patellar replacement and those that had not. However, pain on standing and on ascending or descending stairs as well as tenderness of the patellofemoral joint were only noted in knees that had not had a patellar replacement. These findings suggest that, in order to diminish pain on standing and on using stairs, replacement of the patella during total knee arthroplasty is preferable for patients who have rheumatoid arthritis.

Intramedullary goniometer can improve alignment in knee arthroplasty surgery.

Fifty total knee arthroplasties were performed using an intraoperative intramedullary goniometer to measure the angle of the distal femoral cut. When deviations of 1 degree or more were found, angled cutting blocks ranging from 1 degree to 5 degrees were used to recut the distal femur. Revised femoral cuts were made it 25 knees (50%). Postoperative evaluation from weight-bearing long-standing anteroposterior radiographs revealed an average distal femoral angle deviation from preoperative planning of 0.64 degree (range, 0 degree-3 degrees). This was statistically significantly different from the value for a comparison group of 50 knees on which arthroplasties were performed without the intraoperative goniometer with an average femoral angle deviation of 1.44 degrees (range, 0 degree-4 degrees) (P < .05). In the control group, there were 7 knees (14%) that deviated by 3 degrees or more versus only 2 knees in the study group. The authors conclude that an intramedullary goniometer is fast, is simple to use, and leads to more accurate preparation of the distal femur in total knee arthroplasty.

Soft-tissue balancing with pressure distribution during total knee arthroplasty.

We measured the pressure distribution across the tibiofemoral and patellofemoral joints during total knee arthroplasty (TKA) using Fuji pressure-sensitive film (Prescale) in 51 patients (63 joints) comparing the results with those in 21 patients in whom Prescale was not used. We classified the stress-distribution patterns in the tibiofemoral joints into four types: normal, varus-valgus instability, rotational malalignment, and a combination of instability and malrotation. The medial ligaments were then released according to the information obtained from these patterns. The conformity ratio of the contact area between repeated trials was 87.0%. Pressure distribution across the patellofemoral joints was also considered. There was a significant decrease in the mean valgus stress angle in the Prescale group compared with the control group (p < 0.01). Release of the lateral retinaculum according to the results showed no significant differences in subluxation of the patella between the released group and the group which did not appear to need this procedure.

Heterotopic ossification after total knee arthroplasty.

Heterotopic ossification (HO) is a rare complication following total knee arthroplasty (TKA). In the case report presented, a 52-year-old man who had previously undergone TKA for osteoarthritis noticed painful limitation of range of motion (ROM) in spite of active participation in physical therapy and the use of a continuous passive motion machine. A plain radiograph 1 month after surgery revealed HO anterior to the distal femoral shaft in the quadriceps expansion. Ambulation for this patient was limited to short distances because of severe pain and limitation in ROM. The patient underwent manipulation under general anesthesia 2 months after the TKA. Range of motion in flexion improved from 50 degrees to 110 degrees, and the patient became ambulatory without assistive devices. However, the flexion range deteriorated to 50 degrees over a period of 4 months, and ambulation again became significantly limited. The patient underwent resection of HO 6 months after manipulation and regained his ROM to 110 degrees in flexion. He was prescribed indomethacin after surgery for 2 months to prevent recurrence of HO. Follow-up radiographs 3 months after surgery revealed minimal recurrence of HO. The patient's ROM did not deteriorate, and he remained ambulatory. Heterotopic ossification should be suspected in post-TKA patients if ROM does not improve. Physical therapy including ROM exercises remains an essential component in the treatment of HO. Manipulation under general anesthesia or surgical resection of HO may be inevitable in certain patients whose ambulation is significantly limited.

Comparison of results of different types of knee arthroplasties.

We summarise our experience gained with knee arthroplasties over 18 years. Between 1976 and 1994 1103 knee arthroplasties (1044 primary cases, 59 revisions) were performed at the Orthopaedic Department of the National Institute of Rheumatology and Physiotherapy in Budapest, Hungary. The diagnoses were osteoarthritis (OA) in 50.9%, rheumatoid arthritis (RA) in 40.7% and other causes in 8.4%. The average age of the patients at the time of the operation was 57.6 years (range 14-81 years). The types of primary implant were as follows: 60 constrained (hinge) prostheses, 876 unconstrained (sledge) prostheses, 108 semiconstrained (total condylar) prostheses. The mean follow-up period was 11.4 years for the hinge-type prostheses, 10.3 years for the unconstrained prostheses and 1.6 years for the semiconstrained prostheses. Reviewing the 59 revision cases, we conclude that complications with the constrained prostheses reached 17.8% and, most presented within the 1st year. Because of this high complication rate, the use of hinge prostheses has been reduced in this department to only selected cases. After sledge prosthesis implantation most of the complications (overall 5.3%) appeared after 1 year in aseptic circumstances. Given the short follow-up period of the semi-constrained total condylar knee replacement, apart from one infection in a patient with rheumatoid arthritis no other complication has been recorded. Summarising these data, it can be concluded that on average the knee function, using a standardised scoring system, improved from 38% to over 80% by introducing the semiconstrained total condylar knee prosthesis.

The use of bone graft for managing bone defects in complex total knee arthroplasty.

The use of bone graft to reconstruct defects about the knee remains an important part of the TKA surgeon's armamentarium. While adaptable for almost all defects, its use has been in part replaced by other techniques that may be more readily employed. Nonetheless, it remains a mainstay of defect reconstruction by virtue of its adaptability to a wide variety of defect configurations and clinical situations. By following the principles of grafting enumerated by several investigators, a high degree of success can be attained using bone grafts.

[Embolism and intramedullary femoral surgery]. / Embolies et chirurgie fémorale intra-médullaire.

All intramedullary femoral surgery entails embolic phenomena which explain peroperative collapses formally known as bone cement implantation syndrome, as well as perioperative fat embolism syndromes. Locally, the bigger the cavity is, the higher the number of accidents: 2.5-5 per cent for GUEPAR hinged-knee prosthesis, 1.75 per cent for total hip arthroplasty with long stem, and 0.1 per cent during classic THA with cement limited to the metaphysis. Anomalies in bone vascularization also increase risk: 10.5-13 per cent during prophylactic nailing for shaft metastases, 1-11.5 per cent during hemiarthroplasty cemented in osteoporotic bone of femoral neck fractures, and only 0.1 per cent during THA implanted because of arthrosis. Not only cement, but also rods, reamers, nails, implants, ultrasonic tool for cement extraction, increase the pressure inside the cavity. Methylmethacrylate is no longer the only incriminated factor, even if it is responsible for a major part of the compressive load. The intensity and duration of the pressure are correlated with the number of embolic phenomena and with measured cardiopulmonary parameters. The intracavity fat content is expelled (an empty cavity, as in THA revision, does not lead to embolic phenomena). Then filters through the intraosseous veins whose diameter limit the size of the extruded embolic phenomena. The ultrasonography of the inferior vena cava shows innumerable fine particles and thrombi which are already organized under the influence of procoagulant factors released from the operative shield and which remain crumbly. These emboli cross the cardiac cavities. Transesophageal echocardiography (TEE), of recent use, does quantify the amount of right atrial filling, duration of echogenesis and size of particles: the result is higher in patients who underwent cemented versus noncemented THA: however the embolism score is no an indicator of seriousness because it is not correlated with cardiorespiratory manifestations; TEE shows only one fourth of the patent foramen ovale, whereas the atrial septal defect is surely one of the most efficient systemic invasion mechanisms to produce perioperative fat embolism. Lung response is most often asymptomatic, even if all patients undergoing intramedullary surgery display an increase in pulmonary vascular resistance which is managed by the right heart only, as well as pulmonary (and sometimes systemic) microvascular fat obstruction. Common operating room monitoring procedures do not detect successive embolic phenomena before they cause pulmonary arterial hypertension which then has repercussions on the left heart and in turn causes peroperative hemodynamic accidents. Only pulmonary arterial pressure measurement with a Swan-Ganz catheter gives early and durable signs of an intolerance to embolic load. Preventive treatment is surgical as there is an inverse relation between embolic marrow and marrow eliminated by large volume washes (which is often more effective than draining). Cement indications in older patients as well as the choice of fixation techniques in femoral fractures must take into account the cardio-pulmonary condition of the patient. Resuscitation procedures dealing with these complications end in the patient's death in half of the cases.

[Revision surgery of knee endoprosthesis]. / Wechseloperationen von Kniegelenksendoprothesen.

Thirty-one revisions for aseptic or septic loosening of knee arthroplasty have been performed between 1983 and 1995. In 18 cases we had loosening of uni- or bicondylar prosthesis and in 13 cases a tricompartmental revision arthroplasty. With an average of 53 months (1.5 to 13 years) after the last operation 21 patients could be examined. Main reasons for failure of uni- and bicondylar prosthesis were as well a proceeding of the arthritis in other compartments, instability, incorrect alignment and other reasons depending on the surgical technique. We found similar reasons in aseptic loosening of total knee arthroplasties including wrong choice of non-constrained condylar prosthesis. Seven cases of late infection affected semi-constrained prosthesis. Two of the reimplantations in a 2-stage procedure failed. Using the Insall-Score in the follow-up the patients reached 71.9 points in the knee score and 58.9 points in the functional score. Patients with former aseptic loosening reached better results than these with septic loosening. 38% were absolutely painfree, 14% complained about permanent pain. Unlimited walking was found 5 times, none of the examined persons was unable to walk. Main problems in revision surgery concern reconstruction of a good alignment and the management of bone loss.

Follow up on uncemented total knee arthroplasty.

Follow up data on 42 uncemented total knee arthroplasty patients were examined at an average follow-up period of 5 to 7 years. The prosthetic components were examined clinically using the modified Hospital for Special Surgery knee rating system and radiographically using fluoroscopically guided radiographs. When compared to the preliminary report, the knee rating score dropped from an average of 94 to 78, with most of the poor results due to patellar failure requiring revision. As in our preliminary study, complications centered on the metal-backed patellar component. Revision of the patellar component was required in 19 of 42 knees (45%). Three of 42 (7%) tibial components required revision, and 2 of 42 (5%) femoral components were revised. Interface lucencies were examined and changes were documented. Other complications included osteolysis in 4 of 42 (10%), bent patellar component in 3 of 42 (7%), and loose titanium mesh (5%).

Influence of surgical approach on lateral retinacular releases in total knee arthroplasty.

The rate of lateral retinacular releases in 2 groups of patients who underwent knee surgery performed by the senior author is compared and the factors that contribute to these differing rates are discussed. The first group of subjects consists of 88 patients who had total knee arthroplasties performed with a standard medial parapatellar approach between August 1987 and August 1988. The second group is comprised of 88 patients who had total knee arthroplasties through a midvastus surgical arthrotomy that splits the fibers of the vastus medialis muscle. This method is used by the senior author for all primary total knee arthroplasties. Lateral retinacular releases were performed in 50% of the cases in the medial parapatellar group versus only 3% of the cases in the midvastus group. Patellofemoral instability occurs as a consequence of incising the quadriceps tendon in the medial parapatellar approach and results in the need to perform lateral retinacular releases. The reduction in lateral retinacular releases is attributed to the fact that the midvastus approach leaves the connection of the vastus medialis to the quadriceps tendon intact.

Range of motion in total knee replacement.

This is a multicenter prospective clinical study using a modified Knee Society scoring system which evaluated the effect of age, gender, weight, preoperative range of motion and knee score, previous surgery, and modification of the posterior femoral condyle geometry on postoperative range of motion. The primary outcome variable was change in flexion. The data were collected from 5 surgeons using a single total knee system. The current study has 621 patients enrolled, of which 282 total knee replacements have followup of 12 months and 86 have followup of 24 months. Multivariate analysis was used to evaluate the data. The variables listed were examined as to their relationship to changes in flexion. Patients were divided into 3 groups: preoperative flexion less than 90 degrees, 91 degrees to 105 degrees, and greater than 105 degrees. When comparing the patients with preoperative motion less than 90 degrees to those with motion greater than 105 degrees, the first group improved 26 degrees more than the latter. They also improved 12 degrees more than the midrange group. The midrange group improved 14 degrees more than the upper range group. These values are all adjusted to eliminate differences due to the other variables. None of the other variables showed a significant correlation with the flexion outcome. To analyze the knee score, the group was also divided into 3 groups: preoperative score less than 27, 28 to 40, and greater than 40. The preoperative knee score was the best predictor of the postoperative knee score. The patients with preoperative knee scores below 27 improved 16 points more than those in the 27 to 40 range and 33 points greater than the greater than 40 group. To analyze functional evaluation, the patients were divided into 3 groups based on preoperative score: less than 40, 41 to 50, and greater than 50. Those in the less than 40 group improved 14 points more than the midrange group and 35 points more than the greater than 50 group. Analysis of delta range of motion and delta pain showed similar results. Age, weight, previous open surgical procedure, and altered femoral component contour, did not seem significantly correlated with changes in postoperative flexion. The best predictors of postoperative clinical results are the preoperative scores.

2-stage reimplantation for infected total knee replacement.

Between 1977 and 1983, 64 infected total knee replacements in 60 patients were treated with a 2-stage protocol for reimplantation. The clinical results and survivorship were determined at an average followup of 7.5 years (range, 2-17 years). Surgical protocol included removal of the prosthesis and all cement with thorough debridement of bone and soft tissues. This was followed by 6 weeks of parenteral antibiotics and then reimplantation of a new prosthesis. At followup, 6 knees (9%) had become reinfected, but only 2 with the same organism. Four knees had been revised: 3 for aseptic loosening and 1 for a periprosthetic femur fracture. Two other knees were impending failures due to aseptic loosening. The average Hospital for Special Surgery knee score was 78 points with 18 excellent, 28 good, 13 fair, and 5 poor results. Seventy-eight percent of patients were satisfied with the overall result of their reimplanted prosthesis and 95% think that they made the right decision in undergoing total knee arthroplasty. The 10-year predicted survivorship of 2-stage reimplantation is 77.4%. Two-stage reimplantation with a 6-week course of parenteral antibiotics is an effective means to eradicate deep infection and to provide a functional knee. The long term functional results and overall survivorship are comparable with the results of revision of aseptic failed total knee arthroplasty.

Total knee replacement infection after 2-stage reimplantation: results of subsequent 2-stage reimplantation.

Twelve patients who underwent salvage of an infected total knee replacement with removal, debridement, 6 weeks of parenteral antibiotics, and reimplantation subsequently acquired another infection in the same knee. These patients were again treated with the same protocol followed by reimplantation or arthrodesis and were observed for an average of 31 months. Nine of the patients underwent reimplantation surgery and 3 of the patients underwent arthrodesis. At followup the average Hospital for Special Surgery knee score for the reimplantation group was 84, the average Knee Society knee score was 79, and the average functional score was 73. The 3 patients who did not undergo reimplantation surgery had solid fusions in good position but were dissatisfied with their stiff limb. No knee to date has shown signs of recurrent infection.

Aspiration of the knee joint before revision arthroplasty.

Sixty-four operative procedures were performed on 55 patients with knee arthroplasties for pain, loosening, instability, or suspicion of infection. Forty-three knees had a preoperative aspiration. In 19 knees, the aspiration showed growth on solid media, and in 18 of these knees the diagnosis of infection was confirmed by the intraoperative cultures. In 1 knee with an infected total knee replacement, the patient was receiving an intravenous antibiotic at the time of arthroscopic irrigation and debridement and the cultures showed no growth. In 23 of 24 knees with a negative preoperative aspiration, the intraoperative cultures showed no growth on solid media. In 1 knee with a preoperative aspiration that had negative results, a single intraoperative culture grew Staphylococcus epidermidis. However, the presenting symptoms, examination, preoperative radiographs, and intraoperative evaluation were consistent with aseptic loosening of a cemented total knee arthroplasty. Thus, the preoperative aspiration of the prosthetic knee joint had a sensitivity of 100%, specificity of 100%, and accuracy of 100%. The Westergren erythrocyte sedimentation rate, peripheral leukocyte count, and presenting symptoms correlated poorly with infection. Radiographs were also not helpful in the diagnosis of infection, with loosening of components, periostitis, focal osteolysis, and radiolucent lines frequently seen in infected and noninfected knees. Preoperative aspiration of the knee is the most helpful study for the diagnosis or exclusion of infection in a prosthetic knee joint.