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PubMed1981

Arthrographic and radiologic evaluation of prosthetic joints.

Arthrography is indicated for the evaluation of a prosthetic joint for suspected infection, possible loosening based on clinical or plain radiographic findings, or unexplained pain following the insertion of a prosthesis. Interpretative difficulties most frequently occur when the acetabular component of the hip is evaluated. Also, the femoral component of a total knee arthroplasty is not optimally evaluated with arthrography. The decision to revise a loose prosthetic component is based on a clinical judgment. Arthrographic findings may facilitate this decision, but the decision does not depend solely on the arthrographic results. Rather, they must be evaluated in conjunction with other clinical and radiographic findings to eliminate false positive studies, thereby avoiding unnecessary surgery. In the presence of an equivocal arthrogram, radionuclide bone imaging shows promise as an adjunct for evaluating possible failure of a prosthetic component. It is also useful for evaluating the suspected failure of the femoral component of a knee prosthesis.

Bone Cements↗
PubMed2001

[Knee joint prosthesis implantation after fractures of the head of the tibia. Intermediate term results of a cohort analysis].

A significant number of patients with operated tibial plateau fractures develop osteoarthritis and require total knee arthroplasty. In cases of primary osteoarthritis the results are generally good. However, it is not known whether patients with post-traumatic osteoarthritis obtain comparably favorable results. In a retrospective study we analyzed 72 patients who had undergone a self-aligning (SAL) total knee arthroplasty. Ten patients received arthroplasty due to sequelae of a tibial head fracture (group I). The median time to follow-up in this group was 30 months. Clinical and radiological evaluation was based on the Knee Society Clinical Rating System. The score comprises pain, range of motion, stability, and function. We defined the axis and possible loosening by radiological examination. For comparative descriptive statistics, a cohort of patients was chosen who had received an arthroplasty because of primary gonarthrosis (group II, 76 arthroplasties in 62 patients). The median time to follow-up in this group was 46.5 months. Three patients in group I underwent revision surgery, four patients displayed severe functional deficits and pain, and one patient had a varus deformity with good clinical function. This corresponded to an early complication rate of 27% and a late complication rate of 36%; a relevant instability or loosening of the components did not occur in this group. In group II the incidence of early complications was 10%. The patients in group I reached a mean value of 153 points using the rating system vs 167 points in group II. Analyzing the clinical parameters of the score, we found that patients in group I experienced significantly more pain, thereby affecting functions of daily living, such as walking and climbing stairs. Because of the small number of patients in group I, conclusions can only be drawn to a limited extent. However, we saw that these patients displayed a higher incidence of complications and performed less well. This has to be taken into consideration and discussed prior to surgery.

Activities of Daily Living↗
PubMed2005

The human form: accepting the prioritization of patient values.

A seventeen-year-old boy who had had a subtotal femoral reconstruction because of an osteosarcoma in the left femur, and a subsequent revision for hardware failure, was again having severe pain secondary to failure of the endoprosthesis. The patient's original orthopaedic oncologist, who had performed both previous operations, recommended that the patient have an above-the-knee amputation. The patient and his parents inquired about the Van Nes rotationplasty. They were told directly that it was an antiquated procedure that was not done anymore. The prosthetist with whom they were working gave them the name of an orthopaedic oncologist who could perform the Van Nes procedure. They traveled 850 miles for a consultation, and the patient underwent the procedure. Several months after the operation, the patient walked with a slight limp and looked like a perfectly normal teenager in a pair of jeans. On examination, he had a well-fitted below-the-knee prosthesis attached to his foot, which was in nearly 160 degrees of what was essentially plantar flexion, perfectly matching the attitude of a knee as it couples to a below-the-knee prosthesis. The boy and his parents, who had decided months earlier to opt for an uncommonly performed procedure that would give him a chance at a "normal" appearing and functioning limb, deemed the surgery a complete success with an "excellent" outcome.

Adolescent↗
PubMed2003

Metal-backed patellar component failure in total knee arthroplasty presenting as a giant calf mass.

Failure of total knee arthroplasty (TKA) caused by wear of the polyethylene-bearing surface of a metal-backed tibial platform or a metal-backed patellar component is a recognized complication. We present a case of a 78-year-old woman with a cystic mass in the left calf caused by metal wear debris from the failure of a Miller-Galante I TKA. The patient received a left TKA to treat advanced osteoarthritis in July 1990 and was lost to follow-up immediately after the operation. In December 1998, she presented at our clinic 2 days before admission, when an originally silent mass over the calf turned intolerably painful. A series of examinations revealed a calf mass caused by wear debris of total knee prosthesis and subsequent inflammation of the knee joint. Curettage of the cyst and simultaneous revision TKA were successful in relieving her symptoms.

Aged↗
PubMed1983

Unicompartmental knee arthroplasty for single compartment disease. Clinical experience with an average four-year follow-up study.

Unicompartmental knee arthroplasty using the Marmor modular knee prosthesis or, later, the Richards Modular II prosthesis in a series of 72 knees (60 patients) is reviewed, with an average follow-up period of four years (minimum, 2 years). Pain relief was rated as excellent in 90% of the knees. The average range of motion was improved after operation. No deep infections were encountered. Only one knee in the series has required further surgery, for patellofemoral disease.

Aged↗
PubMed2003

Medical devices; reclassification of the knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis and the knee joint femorotibial (unicompartmental) metal/polymer porous-coated uncemented prosthesis. Final rule.

The Food and Drug Administration (FDA) is announcing that it has reclassified two fixed-bearing knee joint prostheses, the knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis, which is intended to be implanted to replace a knee joint, and the knee joint femorotibial (uni-compartmental) metal/polymer porous-coated uncemented prosthesis, which is intended to be implanted to replace part of a knee joint. FDA has reclassified the devices from class III (premarket approval) into class II (special controls). The special control that will apply is a guidance document entitled "Class II Special Controls Guidance Document: Knee Joint Patellofemorotibial and Femorotibial Metal/Polymer Porous-Coated Uncemented Prostheses; Guidance for Industry and FDA." The agency is reclassifying these devices into class II because special controls, in addition to general controls, will provide reasonable assurance of the safety and effectiveness of the devices, and there is sufficient information to establish special controls. The agency is also announcing that it has issued an order in the form of a letter to the Orthopedic Surgical Manufacturers Association (OSMA) reclassifying the devices.

Device Approval↗
PubMed1999

A new approach of designing the tibial baseplate of total knee prostheses.

OBJECTIVE: To improve the design of the knee prosthesis, a new technique to design the tibial baseplate of total knee prostheses was developed. METHODS: One senior surgeon operated on 79 osteoarthrosis patients by using PCA total knee prostheses for total knee replacement. Four dimensions were measured intraoperatively and compared, including the anterioposterior length and the mediolateral width of the resected tibia plateau and implant. The data of anterioposterior length and the mediolateral width of resected surfaces of the tibial plateau of the 79 patients were plotted in a coordinate system. This coordinate system was formed with the mediolateral width as the x-axis and anterioposterior length as the y-axis. A circle, 5 mm in diameter, was used as the maximum coverage criterion. Five contemporary products and a new design product were used to screen the data to see how many patients would fall within the criteria. From the results of the screened data, we calculated the coverage percentage of the patients. RESULTS: The ratio of the anterioposterior length to the mediolateral width of the resected surfaces of the tibial plateau was greater than that of the ratio of the PCA prostheses (P < 0.05). The results showed that no single product on the market had the patients meet over 70% of the criterion. A different ratio of the anterioposterior length to the mediolateral width was designed to achieve 90% coverage of the patients that met the criterion. DISCUSSION: One possible explanation for the discrepancy between resected surfaces and implants is that the osteoarthrosis patients developed knee deformities that changed the surface of the tibial plateau and thus altered the knee dimensions. Since the total knee prostheses were used on osteoarthrosis patients, the dimensions of the resected tibial surfaces of osteoarthrosis patients should be considered in the design of the tibial baseplate of total knee prostheses.

Aged↗
PubMed2001

[Single-compartment knee arthroplasty prosthesis and idiopathic necrosis of the medial tibia surface].

PURPOSE OF THE STUDY: Idiopathic necrosis of the medial articular surface of the tibia is exceptional. Diagnosis is quite difficult and often made late. Among the different treatments proposed, we preferred single-compartment arthroplasty. MATERIAL AND METHODS: We report 8 cases in women with a mean age of 71.1 years. Diagnosis was suspected due to drug-resistant knee pain, particularly frequent at night, initially with radiographically normal knees. The first radiographic signs, seen 3 months after the onset of pain, were pathognomonic for osteonecrosis evidencing subchondral defects of the tibial surface with a dense peripheral rim and apparently "sequestered" in a notch. Bone scintigraphy evidenced intense uptake in the medial compartment. MRI confirmed the diagnosis evidencing a band of low intensity signals completely surrounding a sequestered zone reaching the cortical. This band was stable and irreversible. In 5 cases CT scan and in 3 cases tomography identified the width and height of the necrotic area that was limited to the medial compartment in all cases. All patients were treated with a single compartment implant. The diagnosis of necrosis was confirmed at pathology. RESULTS: At 4,6 years of mean follow up all patients had an excellent outcome, "forgetting" their knee. No lucent lines developed along the femoral or tibial implants. DISCUSSION: Necrosis of the medial articular surface of the tibia is exceptional and often diagnosed late by bone scintigraphy or MRI. Surgical treatment is usually based on tibial osteotomy for valgisation or a single or three-compartment prosthesis. In our 8 cases, the necrosis was limited to the medial compartment, warranting our therapeutic option.

Aged↗
PubMed2002

Interlimb coordination in prosthetic walking: effects of asymmetry and walking velocity.

The present study focuses on interlimb coordination in walking with an above-knee prosthesis using concepts and tools of dynamical systems theory (DST). Prosthetic walkers are an interesting group to investigate from this theory because their locomotory system is inherently asymmetric, while, according to DST, coordinative stability may be expected to be reduced as a function of the asymmetry of the oscillating components. Furthermore, previous work on locomotion motivated from DST has shown that the stability of interlimb coordination increases with walking velocity, leading to the additional expectation that the anticipated destabilizing effect of the prosthesis-induced asymmetry may be diminished at higher walking velocities. To examine these expectations, an experiment was conducted aimed at comparing interlimb coordination during treadmill walking between seven participants with an above-knee prosthesis and seven controls across a range of walking velocities. The observed gait patterns were analyzed in terms of standard gait measures (i.e., absolute and relative swing, stance and step times) and interlimb coordination measures (i.e., relative phase and frequency locking). As expected, the asymmetry brought about by the prosthesis led to a decrease in the stability of the coordination between the legs as compared to the control group, while coordinative stability increased with increasing walking velocity in both groups in the absence of a significant interaction. In addition, the 2:1 frequency coordination between arm and leg movements that is generally observed in healthy walkers at low walking velocities was absent in the prosthetic walkers. Collectively, these results suggest that both stability and adaptability of coordination are reduced in prosthetic walkers but may be enhanced by training them to walk at higher velocities.

Adult↗
PubMed2000

Primary constrained condylar knee arthroplasty for the arthritic valgus knee.

The purpose of the current study was to review results of primary constrained condylar knee arthroplasty in elderly patients with genu valgum deformity. The hypotheses were: (1) constraint has no adverse effects in elderly patients; (2) treating deformity with a constrained condylar knee prosthesis in lieu of lateral ligament release avoids morbidity, particularly peroneal nerve palsy and flexion instability; and (3) press-fit noncemented stem extensions enhance fixation of the cemented core components and are not prone to loosening. Between 1988 and 1993, 44 consecutive primary Constrained Condylar Knee prostheses were implanted in 37 patients (average age, 72.7 years) with an average valgus angle of 17.6 degrees. Indications for the Constrained Condylar Knee implant were: elderly patients with genu valgum deformity and medial collateral ligament incompetence. Outcome was assessed prospectively using the Hospital for Special Surgery and Knee Society scoring systems; followup was by independent observer. Clinical and radiographic followup (average, 7.8 years) was available for 28 knees (26 patients). The Hospital for Special Surgery score improved from 52.2 to 89.6 points. The average Knee Society score and functional scores improved from 27.4 and 32.4 points to 95.2 and 67.2 points, respectively. At followup, the average alignment based on anteroposterior radiographs obtained with the patient weightbearing was 5.3 degrees. No radiographic loosening, prosthetic failures, peroneal nerve palsies, or flexion instability occurred. No failures occurred in the 11 patients (16 knees) who died before the latest followup. To the authors' knowledge, this is the largest reported series with the longest reported followup of patients with primary Constrained Condylar Knee prostheses. The use of the Constrained Condylar Knee prosthesis for elderly patients with low physical demands with genu valgum resulted in significant pain relief and improved function.

Aged↗
PubMed1997

[Long-term results of condylar reconstruction using patella as vascularized graft].

PURPOSE OF THE STUDY: In 1966, R. Merle d'Aubigné published 4 cases of unicondylar destructions (due to trauma or tumor) reconstructed with the patella replacing the joint surface. Since this time the same technique has been used in 6 other cases. The results of these 10 patients are studied. MATERIAL AND METHOD: Six of the examined patients were treated initially for a giant cell tumor, 1 for a low-grade osteosarcoma, and 3 for post traumatic arthritis. The patellar transplant remains vascularized by it's supero-medial vascular bundle. The femoral condyle was affected in 9 cases, the tibial plateau in one. RESULTS: The long term follow-up of these 10 patients revealed unexpected satisfactory results. None of the operated knees was clinically "excellent", due to instability or axial deterioration, but function remained correct, with a good range of motion, active professional possibilities, and, often, regular practice of some sports, like skiing or tracking. Function was not correlated with radiological aspect. The arthritic remodeling of the knee was obvious in all of the cases, and regularly increasing. Five of the 10 knees had to be reoperated (one or several times): 3 during the first months of follow-up (1 for sepsis, 2 for supracondylar fractures), 5 during the first years, to improve function (2 arthrolysis, 2 valgus osteotomies, 1 loose bodies removal). Three patellar plasties had to be converted into a total knee prosthesis, after 8, 27 and 40 years. The follow-up of the 7 patients still walking on their patellar plasty is of 2, 4, 17, 19, 24, 24 and 25 years. DISCUSSION AND CONCLUSION: Condylar reconstruction using a vascularized patellar transplant is mechanically speaking an approximative, obsolete and rather rough procedure. Nowadays one would prefer a knee prosthesis, with or without auto or allografts, preserving the patella. The immediate functional result would certainly be better, but the future remains uncertain. The patellar plasty can delay for 10, 20 years or even more the time of a prosthesis. This technique might also be useful in countries where prosthetic implants are not easily available.

Arthroplasty, Replacement, Knee↗
PubMed1999

Wear of alumina ceramics prosthesis.

To investigate the process of wear in the total knee prosthesis consisting of alumina ceramics (Al-ceramics) and ultra-high molecular weight polyethylene (UHMWP) in vivo, we observed the fine structures of the articular surface of the prostheses used for four patients with osteosarcoma of the distal femur. We also examined the wear debris in the surrounding soft tissues. The prostheses were extracted at autopsy between 13 and 48 months after surgery. An increase of pores, indicating where Al-ceramics grains fell off, and many streaks on the UHMWP running parallel to the gliding direction of the joint were observed on the articular surface. The streaks had similar widths to the Al-ceramics grains. Al-ceramics debris was detected in the soft tissues around the joint mixed with UHMWP debris. We concluded that the wear of UHMWP in Al-ceramics prosthesis was promoted by interposition of Al-ceramics debris.

Adolescent↗
PubMed2003

Resurfacing knee arthroplasty in patients with allergic sensitivity to metals.

BACKGROUND: The problem of metal sensitivity (Ni, Cr, and Co) in arthroplasty is still unsolved. To prevent the risk of allergy in cases with proved metal allergy in an epicutaneous test, a Natural Knee total knee arthroplasty, made totally from titanium (Ti-6Al-4V) and polyethylene, can be implanted. The results of this device have to be compared to the results of normal knee arthroplasty designed with a femoral component out of CrCoNi alloy. The mechanical resistance of this alloy is much higher than that of titanium, and therefore it is the standard for the femoral components of most knee-resurfacing devices. METHODS: Thirty-five patients with a titanium Natural Knee were examined retrospectively after a mean follow-up of 2 years and 5 months (range 6 months to 5 years and 4 months). In comparison, 36 patients with a Genesis-I knee with a CrCoNi alloy femoral component were studied after a mean follow-up of 2 years and 4 months (range 8 months to 6 years and 2 months). RESULTS: In spite of the lower mechanical resistance of titanium, the Natural Knee showed better results (knee score 84.1 points, function score 77.7 points, HSS score 80.1 points, 82.9% excellent and good results) than the Genesis-I knee (knee score 80.6 points, function score 76.4 points, HSS score 76.4 points, 68.5% excellent and good results), although these differences had no statistical significance. CONCLUSIONS: The titanium Natural Knee prosthesis has proven to be a reliable knee joint replacement in the medium term.

Adult↗
PubMed2002

Salvage of infected total knee fusion: the last option.

Currently the most common indication for an arthrodesis of the knee is a failed infected total knee prosthesis. Other causes of a failed total knee replacement that might necessitate a knee fusion include aseptic loosening, deficient extensor mechanism, poor soft tissues, and Charcot joint. Techniques available for achieving a knee fusion are external fixation and internal fixation methods. The external fixation compression devices have been the most widely used for knee fusion and have been successful until the indications for fusion changed to mostly failed prosthetic knee replacement. With failed total knee replacement, the problem of severe bone loss became an issue, and the external fixation compression devices, even including the biplane external fixators, have been the least successful method reported for gaining fusion. The Ilizarov technique has been shown to achieve rigid fixation despite this bone loss, and a review of reports are showing high fusion rates using this method. Internal fixation methods including plate fixation and intramedullary nails have had the best success in gaining fusion in the face of this bone loss and have replaced external fixation methods as the technique of choice for knee fusion when severe bone loss is present. A review of the literature and a discussion of different fusion techniques are presented including a discussion of the influence that infection has on the success of fusion.

Arthrodesis↗
PubMed1989

Temporary prosthetic fitting for below-knee amputation.

The problems encountered in fitting and using the permanent below-knee prosthesis in developing countries are the high price of the prosthesis, inadequate fitting and lack of proper rehabilitation. In Turkey, the preferred treatment of the stump post-operatively is by the soft dressing method with bandaging for maturation and shrinkage. Generally, the application of the permanent prosthesis is in the sixth month post-operatively. Since in patellar-tendon-bearing (PTB) sockets, stumps have to withstand high pressures in limited areas, the PTB socket can only tolerate small volume changes in the stump. For this reason bandaging over a long period may be insufficient for adequate stump shrinkage and amputees will need another below-knee prosthesis, which most of them cannot afford after only a few weeks use. In the authors' clinic, 19 amputees were fitted with simple, effective and inexpensive temporary prostheses following either conventional immediate post-operative dressing or the soft dressing method. The temporary prosthesis is worn for two months. It produces fast stump shrinkage, helps maturation and permits ambulatory discharge even in bilateral amputees. For economical reasons, only eight of nineteen patients were fitted with permanent prostheses, all wearing them successfully without the necessity of further rehabilitation.

Adult↗
PubMed2003

Positioning of total knee arthroplasty with and without navigation support. A prospective, randomised study.

We conducted this prospective randomised and externally evaluated study to investigate whether the use of a navigation system during total knee arthroplasty leads to significantly better results than the hand-guided technique. A total of 240 patients was included in the study. All patients received a condylar knee prosthesis. Two surgeons performed all the operations using the Stryker knee navigation system. Exclusion criteria included the necessity for the primary use of constrained implants. The results revealed a highly significant difference between the two groups in favour of navigation with regard to the mechanical axis, the frontal and sagittal femoral axis and the frontal tibial axis (p < 0.0001). The use of a navigation system was therefore shown to improve the alignment of the implant.

Aged↗
PubMed2002

[Correlation of electromyography and clinical results after bicondylar knee joint prosthesis implantation].

AIM OF THE STUDY: To investigate clinical findings in patients receiving bicondylar sledge prostheses, and their correlation with electromyographic measurements in comparison with healthy volunteers. MATERIAL AND METHODS: An average of 31.9 months after implantation of a bicondylar sledge prosthesis, 15 patients were clinically examined and compared with 11 control subjects. Electromyographic measurements of the rectus femoris, vastus medialis and lateralis, semitendinosus, biceps femoris, tibialis anterior, and gastrocnemius muscles were obtained. RESULTS: All clinical scores were significantly poorer in the patient group. The activity of the vastus lateralis was significantly reduced. The activity in the lower leg of the operated side was significantly higher than in the control group. Significant differences were found in the tibialis anterior and gastrocnemius muscles between controls and patients. Analysis of the correlation between the clinical scores and the electromyographic measurements showed no significance. CONCLUSION: The clinical results correlated only slightly with the electromyographic activity of the muscles investigated. The commonly presumed quadriceps insufficiency was not confirmed.

Aged↗
PubMed2001

Regional hemostatic status and blood requirements after total knee arthroplasty with and without tranexamic acid or aprotinin.

UNLABELLED: Antifibrinolytics seem to reduce postoperative blood loss after total knee arthroplasty. Few studies have shown the impact of these drugs on the mechanisms of coagulation. The purpose of this study was to examine coagulation/fibrinolysis variables as well as blood loss after total knee arthroplasty with and without antifibrinolytics in the operated limb on a regional level. Thirty-six patients were randomized into one of three groups to receive aprotinin, tranexamic acid, or no medication. We took blood samples of the femoral vein before deflating the tourniquet and after 5, 10, 30, 60, 120 min and on the first postoperative day. The implantation of a knee prosthesis in artificial ischemia caused a significant activation of coagulation and fibrinolysis in the regional circulation. Tranexamic acid and aprotinin did not cause a significant modulation of fibrinolysis variables or a significant reduction of postoperative bleeding and transfusion requirements. One of the differences in comparison to other studies was the decreased total blood loss. The use of bone cement as well as surgical hemostasis before wound closure may be regarded as reasons for this. Therefore, primarily these methods should be used because there is no increased risk of adverse drug effects. IMPLICATIONS: After total knee arthroplasty total blood loss may be kept in a low range if methods such as cemented knee prosthesis and surgical hemostasis are used. In this case aprotinin and tranexamic acid did not cause a significant modulation of fibrinolysis variables or a significant reduction of postoperative bleeding.

Adult↗