Total knee arthroplasty in morbidly obese patients

We reviewed the clinical outcomes of fifty primary total knee arthroplasties that had been performed with cement in forty patients who were considered morbidly obese (a Quetelet index of more than forty). These results were compared with those of 1768 similar procedures, performed during the same time-period by the same surgeon, in 1539 patients who were not morbidly obese (controls). At a mean of approximately five years postoperatively, there was a significant difference between the morbidly obese patients and the control group with regard to the knee and functional scores (84 and 53 points compared with 92 and 67 points; p < 0.00005 for both scores). No significant difference was detected, with the numbers available, with regard to the range of motion or the radiographic score (p = 0.77). The rate of perioperative complications was significantly higher in the morbidly obese patients (p < 0.00005). Of the fifty knees in these patients, eleven (22 percent) had a wound complication, five (10 percent) had an infection, and four (8 percent) had an avulsion of the medial collateral ligament. The five infections developed within twenty weeks after the operation, and three were associated with a wound complication. In comparison, thirty-five (2 percent) of the 1768 knees in the control group had a wound complication, eleven (0.6 percent) had an infection, and none had an avulsion of the medial collateral ligament. We concluded that total knee arthroplasty in morbidly obese patients can be successful but is associated with an increased rate of perioperative complications, including problems with wound-healing, infection, and avulsion of the medial collateral ligament. Alterations in the operative technique for soft-tissue closure and protection of the medial collateral ligament have decreased the rates of complications related to wound-healing and the medial collateral ligament.     

Total knee arthroplasty without patellar resurfacing in active and overweight patients

Chlamydia trachomatis is a frequent sexually transmitted disease. The diagnosis of C. trachomatis infection by cytology is controversial. We compared the ability of Papanicolaou (Pap) smears to detect C. trachomatis infection with antigen detection (enzyme immunoassay; EIA) and polymerase chain reaction (PCR). One hundred sixty-seven women attending a therapeutic abortion clinic were enrolled in the study. Endocervical samples were first collected for EIA and PCR, and then Pap smears were prepared for cytologic evaluation. Eight patients were excluded from the study due to the lack of an endocervical component. The criteria established by Gupta and associates (Diagn Cytopathol 1988;4:224-229; Acta Cytol 1979;23:315-320) were used in this study to assess the specificity and sensitivity of the Pap smear in recognizing C. trachomatis infection. After EIA testing, the remaining sample was subjected to phenol-chloroform extraction to purify the DNA and then tested by PCR. Positive PCR samples were subjected to repeat phenol-chloroform and retested to confirm the positive result. Using a confirmed PCR or a blocked EIA as the extended gold standard, the incidence of C. trachomatis infection was 9.4%. Fifteen of the 159 cases reviewed were positive by extended gold standard. Thirteen (86.7%) of those 15 cases were interpreted as negative by cytology (false-negatives), and two (13.3%) cases were positive. Of the remaining 144 cases, 14 cases (9.7%) were interpreted as positive by cytology (false-positives) but were not confirmed by the extended gold standard. Ten (66.7%) of the 15 cases confirmed by the extended gold standard were interpreted as negative by EIA (false-negatives), and five (33.3%) were positive. There were no false-positives by EIA. In this study, the sensitivity and the specificity for cytology were 13.3% and 90.3%, respectively. The positive predictive value was 12.5%, and the negative predictive value for cytology was 90.9%. The sensitivity and the specificity for EIA were 33.3% and 100%, respectively. The positive predictive value was 100%, and the negative predictive value for EIA was 93.5%. Both EIA and cytology are insensitive methods compared with PCR. Based on these data, cytology should not be used to diagnose C. trachomatis infection in an asymptomatic female population with a moderate risk of C. trachomatis infection.     

Total knee arthroplasty covered with pedicle peroneal flap

Three cases of total knee arthroplasty (TKA) covered with pedicle peroneal flaps are reported. One peroneal flap was performed after TKA to correct post-TKA skin necrosis. Two peroneal flaps were performed before TKA to replace previous traumatic scar formed around the knee. All three TKAs were successful after the procedure. The thickness, elasticity, appearance, and durability of the peroneal flaps were more suitable for the skin around the knee than the gastrocnemius muscle flap or the local fasciocutaneous flap. As the peroneal flap was elevated as a pedicle flap, freedom of transfer was good, microanastomosis was not necessary, and no donor sites were needed from the contralateral limb. Scar tissue around the knee can be effectively replaced by the pedicle peroneal flap before TKA.     

Total knee arthroplasty kinematics. Computer simulation and intraoperative evaluation

Early diagnosis of rejection is a pivotal problem in renal transplantation. Recent advances in urinary cell analysis using flow cytometry are still burdened with difficulties concerning urine lymphocyte (UL) isolation. The analysis of lymphocytes washed out with the urine from the kidney transplant offers a tool to monitor noninvasively the intragraft immune response. However, the demand for optimal isolation of UL with high viability and good separation of other cell types has not, as yet, been met. The present study was undertaken to evaluate the optimal conditions for harvesting UL in order to perform adequate UL analysis by flow cytometry. We found that UL viability is mainly dependent on the time of urine harvesting. Low UL viability was caused by high urine osmolality due to high concentrations of urea and glucose. In contrast, high protein concentrations protected UL viability. Hence, the following algorithm of adequate UL isolation for flow cytometric analysis was established: (1) Collection of morning urine directly onto foetal calf serum (FCS: 30% v/v): (2) UL isolation within 2 h; (3) Erythrocyte lysis with subsequent two-step density gradient isolation of UL from residual erythrocytes, granulocytes (Ficoll-Isopaque, 1.077 g/cm3) and from uroepithelial cells (30% methylglucamine 3,5-diacetomido-2,4,6-triiodobenzoicum, 1.085 g/cmn3); (4) Flow cytometric analysis of UL using the 'live gate' setting in the area of blood lymphocyte cluster. Adequate UL isolation and special settings of the flow cytometer may provide a useful tool for early diagnosis and the noninvasive monitoring of renal transplant rejection.     

Total knee arthroplasty in the elderly: patients'' self-appraisal 6 and 12 months postoperatively

The classic goals of nutritional support have been to provide for the patient's ongoing nutritional needs and to preserve endogenous tissues from further catabolism. It is becoming increasingly clear that it also is possible to modulate metabolic and pathologic processes through the use of specific nutrients and metabolites and even the route by which nutrition is provided. This article discusses what is and is not known about the nutritional requirements of critically ill dogs and cats and some of the specific nutrients that are being used to enrich formulas for critically ill patients.     

Total hip arthroplasty in patients who have chronic lymphocytic leukemia

Twenty patients who had chronic lymphocytic leukemia underwent 25 elective primary total hip arthroplasties at the Mayo Clinic. No patient had a postoperative prosthetic infection. No patient had an intraoperative or postoperative hemorrhagic complication. One patient had a revision for aseptic loosening. After an average follow-up period of 4.6 years, there were 84% good and excellent results. It is concluded that patients who have early-stage chronic lymphocytic leukemia may not be at increased risk for major perioperative or postoperative complications in total hip arthroplasty. The surgeon must remain vigilant for postoperative complications, but satisfactory clinical results can be obtained in this patient population.     

Total wrist arthroplasty

Although arthroplasty is a well-established procedure for many joints, its use in the wrist is less common, and the indications are less well defined. The standard procedure for the painful arthritic wrist remains radiocarpal arthrodesis. However, as technology and surgical procedures improve, wrist arthroplasty is being used more frequently. The authors provide a brief history of total wrist arthroplasty and review the arthroplasties most commonly used in the United States. Results with total wrist implants, the complications related to arthroplasty, technical aspects of the procedure, and salvage options are also discussed.     

Total hip arthroplasty

Total hip arthroplasty, or surgical replacement of the hip joint with an artificial prosthesis, is a reconstructive procedure that has improved the management of those diseases of the hip joint that have responded poorly to conventional medical therapy. In this review we briefly summarize the evolution of total hip arthroplasty, the design and development of prosthetic hip components, and the current clinical indications for this procedure. The possible complications of total hip arthroplasty, its clinical performance over time, and future directions in hip replacement surgery are also discussed.     

Polycentric total knee arthroplasty

Polycentric total knee arthroplasty in 56 patients provided significant relief of pain in 90.7% and a stable knee in 92.7%. Postoperative increase in range of motion averaged 13.7 degrees for all patients (18.5 degrees in rheumatoid arthritis and 8.7 degrees in degenerative arthritis). This increase in excursion is attributed to the design of the prosthesis, a vigorous postoperative rehabilitation program, and careful surgical technic. A failure rate of 12.7% was due to infection, mechanical instability and unexplained pain. Contraindications to surgery and technical recommendations are noted.     

Hinged total knee arthroplasty

Analysis of an on-going prospective study of seventy-seven hinged total knee arthroplasties in sixty-seven patients revealed that most patients had improvement in function, although major complications occurred in eighteen knees (23.4 per cent. These complications included sepsis, loosening, patellar tendon rupture, peroneal palsy, and patellar subluxation. Eight of nine knees with deep sepsis required removal of the prosthesis, and three of sixteen knees with patellar pain required realignment of the quadriceps. When prosthetic failure occurred, salvage of a functional extremity was difficult. Hinged total arthroplasty is not without its problems, and a cautious approach to its use is indicated. Whenever possible, a moderately constrained replacement arthroplasty should be considered.     

Hybrid total knee arthroplasty

A prospective study of a hybrid total knee arthroplasty (TKA) with an uncemented femoral component and cemented tibial and patellar components was performed to combine the advantage of a press-fit femur while avoiding the problems in uncemented tibial and patellar implants. A total of 329 posterior cruciate-preserving TKA were studied at an average of 4.7 years after surgery: 84% of the knees had at most mild or occasional pain, 68% had good or excellent knee scores, and 62% could walk more than 1000 m. The function scores were 40% good or excellent in this collective, with an average age of 69.4 years at surgery. The component position and alignment were biomechanically correct. Radiolucent lines were observed regularly at the edges of the tibial and femoral components. There were no revisions for aseptic loosening. Hybrid TKA provides good results comparable to cemented TKA.     

Revision total knee arthroplasty after failed unicompartmental knee arthroplasty or high tibial osteotomy

A retrospective matched-pair comparative analysis was done between 30 total knee arthroplasties following failed high tibial osteotomies and 30 total knee arthroplasties following failed unicompartmental knee arthroplasties. The groups were matched according to age, gender, type of prosthesis, primary disease, and length of followup. A minimum followup of 2 years was required for inclusion in the study, and the average followup was 3.8 years (range, 2-9 years). The Knee Society Knee Score for the high tibial osteotomy group was significantly higher than that for the unicompartmental arthroplasty group. More osseous reconstructions were required in the unicompartmental revisions. Difficulty with exposure was not significantly greater in the osteotomy group. Rates of component loosening were not significantly different between the groups. A failed unicompartmental knee arthroplasty and a failed high tibial osteotomy can be revised successfully to a total knee arthroplasty. The results confirm that revisions after unicondylar arthroplasty and high tibial osteotomy are technically demanding. In this series, the results of total knee arthroplasty following unicompartmental knee arthroplasty approached but did not equal those obtained after high tibial osteotomy.     

Long-term evaluation of hip arthroplasty in patients with an ipsilateral knee arthrodesis

Hip arthroplasty with an ipsilateral knee arthrodesis occurs infrequently but does raise concern regarding surgical technical difficulties, dislocation, sepsis, and long-term loosening. Sixteen patients were evaluated 7.5 years (average period) after surgery. Technical difficulties were not prohibitive. No dislocation or revision was necessary in any of the cases. Two patients died as a result of unrelated sepsis from an infected knee. Loosening and protrusio of the acetabulum occurred in two patients. Hip arthroplasty in patients with a fused knee does not incur undue risk of loosening or instability and can provide long-term good function and pain relief. Patients with multiple joint arthroplasties, in whom concurrent sepsis occurs, can have devastating results.     

Flexion space configuration in total knee arthroplasty

Equal resection of the posterior femoral condyles combined with a 90 degree tibial resection results in a trapezoidal flexion space. Two groups of patients were studied; in one group, the flexion space was allowed to remain trapezoidal, whereas in the other group, the anteroposterior femoral resections were externally rotated to allow rectangularization of the flexion space. In the second group, the range of flexion was increased and the incidence of medial tibial pain and zone I radiolucencies decreased. Other than for knees in a hypervalgus position before surgery, the mean amount of rotation required was 3 degrees +/- 0.2 degrees.     

Patellofemoral complications in symmetrical total knee arthroplasty

A review of 356 Kinemax (Howmedica, Inc, Rutherford, NJ) cemented posterior cruciate ligament-retaining condylar total knee arthroplasties employing a symmetrical femoral component articulating with a medially offset symmetrical dome patella component was carried out to examine the results and determine the incidence and nature of the patellofemoral complications. Follow-up was from 3 to 8 years, with a mean of 5.1 years. A review of patellofemoral complications in previously reported homogeneous series of symmetrical and asymmetrical implants is presented. Mean postoperative Knee Society scores improved to 91, function scores to 86, and Hospital of Special Surgery scores to 90 yielding 95% good and excellent results. Mean postoperative range of motion was -1.5 degrees extension to 113 degrees flexion. There were five patellofemoral complications (1.4%), including two symptomatic subluxations, two distal pole avulsion fractures, and one lateral facet fracture. There were two reoperations necessary for patellofemoral problems (0.56%), one to correct subluxation and one for excision of the fractured lateral facet. These rates are lower than those previously reported for asymmetrical implants as well as current and phased-out symmetrical designs of total knee arthroplasty in the intermediate term. This review suggests that cemented total knee arthroplasty with symmetrical patellofemoral resurfacing with an offset patella dome and posterior cruciate ligament retention yields low patellofemoral complications and reoperations. The symmetrical femoral component appears to be a satisfactory compromise of "normal" femoral anatomy, which decreases inventory and cost without adversely affecting patellofemoral function and complications.     

Prediction of postoperative knee flexion in Insall-Burstein II total knee arthroplasty

Postoperative knee flexion in patients undergoing Insall-Burstein-II total knee arthroplasty at 2 years was evaluated regarding two basic questions: what groups of patients gain or lose the most flexion and what groups of patients have the best or worst postoperative flexion. Thirteen preoperative variables (maximum flexion, flexion arc, tibiofemoral angle, quadriceps strength, extensor lag, Knee Society score, Knee Society patient assessment, gender, age, height, weight, diagnosis, and surgeon) and four postoperative variable (leg length change, tibiofemoral angle, distance from patella to the joint line, and the tibial prosthesis anteroposterior translation on a lateral radiograph) were used in an attempt to explain postoperative flexion. The analysis was performed on 164 consecutive Insall-Burstein-II total knees in which the data were gathered prospectively on a time oriented medical record database. A regression tree analysis was used to identify several groups of patients, characterized by preoperative factor values, who had markedly above average performance on postoperative flexion. The preoperative factors identified include preoperative flexion, flexion arc, tibiofemoral angle, extensor lag, diagnosis, and age. The only postoperative variable of significance was tibiofemoral angle. Among the potential determinants of postoperative flexion that failed to appear predictive were the Knee Society scores and surgeon. Preoperative flexion is known to be a critical determinant of postoperative flexion in total knee replacement. However, in the current study, preoperative flexion accounted for only half of the difference between the best (122 degrees) and the worst (88 degrees) group, as determined with regression tree analysis.     

Total elbow arthroplasty as primary treatment for distal humeral fractures in elderly patients

We retrospectively reviewed the results of primary total elbow arthroplasty for the treatment of an acute fracture of the distal aspect of the humerus in twenty consecutive patients (twenty-one elbows) who had a mean age of seventy-two years (range, forty-eight to ninety-two years) at the time of the injury. The patients were managed between November 1982 and October 1992. The presence of rheumatoid arthritis in nine patients (ten elbows) influenced the choice of treatment. The mean interval between the injury and the total elbow arthroplasty was seven days (range, one to twenty-five days). The mean duration of postoperative hospitalization was seven days (range, four to thirteen days). The mean duration of follow-up was 3.3 years (range, three months to 10.5 years). All patients were followed for a minimum of two years or until the time of death; the duration of follow-up was less than two years for three patients who died. None of the patients were lost to follow-up. Twenty implants were intact at the latest follow-up examination. One patient had a revision total elbow arthroplasty twenty months after the index procedure because of a fracture of the ulnar component sustained in a fall on the outstretched arm. On the basis of the Mayo elbow performance score, fifteen elbows had an excellent result and five had a good result; there were inadequate data for one elbow. There were no fair or poor results. The mean arc of flexion was 25 to 130 degrees. There was no evidence of loosening on the radiographs. Postoperative complications included fracture of the ulnar component in one patient, ulnar neurapraxia in three, and reflex sympathetic dystrophy in one. The results suggest that total elbow arthroplasty can be an alternative form of treatment of a severely comminuted fracture of the distal aspect of the humerus in older patients even in the presence of rheumatoid arthritis. This procedure is not an alternative to osteosynthesis in younger patients.