Failure of a metal-reinforced tibial post in total knee arthroplasty

Failures of the polyethylene tibial post in posterior stabilized total knee arthroplasty are usually associated with pain and knee instability. We report an unusual presentation of a tibial post failure that occurred after the polyethylene insert was revised in a posterior-stabilized total knee. The tibial post on the revised insert broke off, exposing a metal reinforcing pin. During the resulting posterior subluxations of the tibia, the metal pin articulated against the cam on the femoral component, resulting in the generation of metallic debris in the knee joint.     

Pain management after total knee arthroplasty: A prospective randomized study

IntroductionTotal knee arthroplasty (TKA) is a common procedure for improving mobility and quality of life in patients with osteoarthritis. Postoperative pain control management after TKA is still a concern as it relates to patients satisfaction and functional recovery.Many anesthetic regimens and techniques have been explored to decrease postoperative pain and enhance the fast recovery after TKA. The aim of this study was to evaluate the best anesthetic treatment in pain control after TKA.Methods51 patients were included in a randomized prospective study and distributed in three groups. The first group (CG) in which no analgesic protocol was implemented (control group). The second group (LIA group) received an intraoperative local infiltration anesthesia (LIA) (60 ml mixture of two ropivacaine 75mg/10 mL + adrenaline 100μg/10 mL + physiological solution). The third group (FNB group) had only a femoral nerve block (FNB). Continuous outcomes including visual analogue scale (VAS) at 5,24,48 h and at 1 week, morphine consumption and range of motion (ROM) at 1,2,7 days.ResultsThere was significant difference between all groups (p < 0,001) in terms of the VAS score: at 5h after surgery (4.55,2.15,1.82); at 24h (4.15,2.65,3.36); at 48h (3.85,2.45,2.73); at 1 week (2.95,1.80, 1.64), respectively for groups CG, LIA, FNB.ROM was better in LIA and FNB groups than CG: at 1 die after surgery (44°,50°,54°); at 3 dies (69°,70°,71°); at 7 dies (91°,98°,98°), respectively for groups CG, LIA, FNB (p < 0,001).DiscussionLIA and FNB groups both showed a significant reduction at VAS score, better range of motion and less morphine consumption than CG (control group). LIA group has obtained a constant pain control in the postoperative days; FNB group had a good pain control in the hours after surgery, with a decrease in efficacy in the following days.ConclusionFurther studies are still needed in order to define LIA as the reference pain management in TKA.     

An articulating spacer to treat and mobilize patients with infected total knee arthroplasty

This retrospective study analyzed 25 consecutive patients (25 knees) with chronic deep TKA infection. During 1997-2004, patients underwent two-stage articulating spacer surgery. The original femoral component was removed, autoclaved and replaced and a new polyethylene was utilized. The second- stage procedure occurred at a mean of 11 weeks (range: 4 to 39 weeks) after spacer insertion. Mobilization was encouraged between stages. All patients were assessed at a minimum of two years (mean 54 months; range: 24-108 months) post re-implantation, and Modified Hospital for Special Surgery (HSS) knee scores were calculated. Only one patient (4%) had re-infection. Average ROM before re-implantation was 5 degrees to 112 degrees , and 3 degrees to 115 degrees at latest follow-up. HSS scores averaged 91 (Range: 65-100) at latest follow-up. Two-stage re-implantation with an articulating spacer for infected TKA effectively treats infection and gives excellent knee motion between stages, and at mid- to long-term follow-up.     

Osteolysis after unidirectional and multidirectional mobile-bearing total knee arthroplasty in young patients

We questioned whether a difference exists between multidirectional and unidirectional mobile-bearing total knee arthroplasties in terms of clinical results and the prevalence of polyethylene wear and periprosthetic osteolysis. We studied 62 patients who underwent simultaneous bilateral total knee arthroplasties, with a unidirectional prosthesis implanted in 1 knee and a multidirectional one in the other. Of the patients, 9 were men and 53 were women, with a mean age of 57.6 years (35-60 years). The minimum follow-up was 11 years (mean, 11.8 years; range, 11-13 years). Preoperative and postoperative knee and functional scores were not different between the 2 groups. No knee in either group had detectable tibial polyethylene liner wear or osteolysis on radiographs or on computed tomography scans. Two (3%) knees in each group were revised.     

Instability after total knee arthroplasty: Wobble and buckle

Instability after total knee arthroplasty (TKA) is a common reason for component failure and revision surgery. These patients require a thorough workup at presentation in order to accurately diagnose instability as being the cause for the patient’s symptoms and to identify the reason for the knee instability. Instability after TKA is classified as global versus isolated instability. The isolated instability can be further categorized as extension instability, flexion instability, or recurvatum. The goal of revision surgery for instability is largely to recreate equal flexion and extension gaps. Good results can be obtained after revision surgery for instability.     

Revision knee arthroplasty with a rotating-hinge design in elderly patients with instability following total knee arthroplasty

Background

Revision knee arthroplasty with a rotating-hinge design could be an option for the treatment of instability following total knee arthroplasty (TKA) in elderly patients.

Purpose

To evaluate the clinical and radiographic results of revision arthroplasties in TKAs with instability using a rotating-hinge design in elderly patients.

Methods

We retrospectively reviewed 96 rotating-hinge arthroplasties. The average age of the patients was 79 years (range, 75–86 years); the minimum follow-up was 5 years (mean, 7.3 years; range, 5–10 years). Patients were evaluated clinically (Knee Society score) and radiographically (position of prosthetic components, signs of loosening, bone loss).

Results

At a minimum followup of 5 years (mean, 7.3 years; range, 5–10 years), Knee Society pain scores improved from 37 preoperatively to 79 postoperatively, and function scores improved from 34 to 53. ROM improved on average from −15° of extension and 80° of flexion before surgery to −5° of extension and 120° of flexion at the last followup (p = 0.03). No loosening of implants was observed. Nonprogressive radiolucent lines were identified around the femoral and tibial components in 2 knees. One patient required reoperation because of a periprosthetic infection.

Conclusions

Revision arthroplasty with a rotating-hinge design provided substantial improvement in function and a reduction in pain in elderly patients with instability following TKA.

Level of evidence

Level IV, therapeutic study.     

Patient-specific instruments in total knee arthroplasty

Purpose

In recent years, patient-specific instruments (PSI) has been introduced with the aim of reducing the overall costs of the implants, minimising the size and number of instruments required, and also reducing surgery time. The purpose of this study was to perform a review of the current literature, as well as to report about our personal experience, to assess reliability of patient specific instrument system in total knee arthroplasty (TKA).

Methods

A literature review was conducted of PSI system reviewing articles related to coronal alignment, clinical knee and function scores, cost, patient satisfaction and complications.

Results

Studies have reported incidences of coronal alignment ≥3° from neutral in TKAs performed with patient-specific cutting guides ranging from 6 % to 31 %.

Conclusions

PSI seem not to be able to result in the same degree of accuracy as the CAS system, while comparing well with standard manual technique with respect to component positioning and overall lower axis, in particular in the sagittal plane. In cases in which custom-made cutting jigs were used, we recommend performing an accurate control of the alignment before and after any cuts and in any further step of the procedure, in order to avoid possible outliers.     

Effect of the timing of tourniquet release on perioperative blood loss associated with cementless total knee arthroplasty: a prospective randomized study

The control of perioperative blood loss is a major concern in cementless knee arthroplasty surgery. We randomized retrospectively 55 patients (60 knees in total) who had undergone cementless total knee arthroplasty and determined the efficacy of tourniquet release either "before" (30 knees) or "after" (30 knees) wound closure. Measurements of total blood loss showed significant differences between the groups ("Before" group, 906 +/- 238 mL; "After" group, 731 +/- 332 mL; P = .0225). The levels of red blood cells, hemoglobin, and hematocrit recovered to the preoperative levels by 3 months after surgery in both groups. In summary, we recommend that the tourniquet be released after wound closure and that a compressive dressing be applied with the aim of limiting or reducing perioperative blood loss without significant effects of the transfer requirement in the 2 groups, provided that tourniquet time is kept below 60 minutes to avoid ill effects of the tourniquet.     

Predicting need for allogeneic transfusion after total knee arthroplasty

Total knee arthroplasty (TKA) can lead to substantial blood loss. To avoid the high costs of autologous blood predonation programs and efficiently allocate limited blood resources, we sought to identify preoperative and intraoperative factors associated with allogeneic blood transfusion (AllTx) after primary TKA and, subsequently, develop a model to predict patients who will require AllTx. We analyzed 31 independent variables in 644 primary unilateral TKAs without autologous blood predonation for requirement of AllTx. Seventy-one procedures (11.0%) required AllTx. Age, comorbid anemia, preoperative hemoglobin concentration, and surgical time were significant predictors for requiring AllTx. When applied to an independent cohort, our model for predicting the need for AllTx after TKA was 90% sensitive and 52.5% specific.     

Changes in lower extremity 3-dimensional load-bearing axes before and after mobile-bearing total knee arthroplasty

This study evaluated changes in the lower extremity 3-dimensional load-bearing mechanical axes in the anteroposterior and mediolateral directions before and at 3 weeks after mobile-bearing total knee arthroplasty. The effects of the degrees of anteroposterior constraint of the designs on the location of the load-bearing mechanical axis at the knee joint level were also assessed. We evaluated 151 knees from 134 patients with 74 knees receiving meniscal bearing-type and 77 knees receiving rotating platform-type prostheses. In the mediolateral direction, both designs showed significant improvements, whereas in the anteroposterior direction, they revealed no improvements postoperatively and were worsened significantly in meniscal bearing type. Differences in the degree of bone and soft tissue involvement for the correction of alignment may explain the findings.     

Postoperative management after total hip and knee arthroplasty

Despite major advances in the field of total joint arthroplasty, a standardized postoperative management protocol currently does not exist following total hip arthroplasty (THA) and total knee arthroplasty (TKA). A survey was mailed to the active members of the American Association of Hip and Knee Surgeons to investigate issues such as postoperative rehabilitation and activity restriction. The information derived from this survey provides the total joint surgeon with a compilation and consensus of responses that can serve as the foundation for a standardized postoperative protocol for THA and TKA surgery.     

Effect of tourniquet application on deep vein thrombosis after total knee arthroplasty

Introduction There is a great deal of controversy about the effect of tourniquets on development of deep vein thrombosis (DVT) after total knee arthroplasty (TKA). Patients and methods We investigated the incidence of postoperative DVT after TKA with or without the use of a tourniquet. The patients were 48 consecutive patients undergoing primary ipsilateral cemented TKA for osteoarthritis. Group A (21 patients) underwent the operation without a tourniquet, and Group B (27 patients) underwent the operation with a tourniquet. Ultrasonography to assess DVT was performed before and after the operation. Results Group B had less intraoperative and total blood loss than Group A. Postoperative DVT was detected in 81.3% of all cases, and symptomatic pulmonary embolism occurred in 1.7%. Most of DVT was found in the calf vein. There was no significant difference in the incidence of postoperative DVT between the two groups. Conclusion We conclude that the use of a tourniquet is beneficial, because it decreases perioperative blood loss and does not increase the risk of DVT. The incidence of DVT after TKA is considerably high with or without use of a tourniquet. Therefore, prevention and early detection of DVT are important for prevention of fatal pulmonary thromboembolism.     

Magnetic resonance angiography in the management of recurrent hemarthrosis after total knee arthroplasty

Spontaneous hemarthrosis is an infrequent but disabling complication after total knee arthroplasty. The purpose of this case series is to demonstrate the utility of magnetic resonance angiography (MRA) in the evaluation of hemarthrosis after total knee arthroplasty. Patients presenting with hemarthrosis unexplained by trauma, anticoagulation, or a bleeding diathesis were retrospectively identified. Eighteen patients were referred for MRA to evaluate recurrent hemarthrosis after failing conservative therapy (n = 16) or synovectomy (n = 2). Despite artifact caused by the metallic components, diagnostic evaluation of regional vessels was made. In 12 of 13 cases that underwent embolization or synovectomy, a hypertrophic feeding artery (or arteries) was visualized on MRA. One case of negative MRA did not have subsequent surgery, and we are unable to comment on the rate of false-positives because all patients in this case series had evidence of bleeding. By characterizing the vascular anatomy and identifying a dominant artery (or arteries) supplying the hypervascular synovium, MRA can serve as a guide for subsequent embolization or synovectomy, as indicated.     

Brake response time before and after total knee arthroplasty: a prospective cohort study

Background  

Although the numbers of total knee arthroplasty (TKA) are increasing, there is only a small number of studies investigating driving safety after TKA. The parameter 'Brake Response Time (BRT)' is one of the most important criteria for driving safety and was therefore chosen for investigation.     

Preoperative risk factors for deep vein thrombosis in knee osteoarthritis patients undergoing total knee arthroplasty

BackgroundTo analyze the risk factors for preoperative deep vein thrombosis (DVT) in knee osteoarthritis (OA) patients undergoing total knee arthroplasty (TKA).MethodsIn this retrospective study, a total of 584 knee OA patients undergoing TKA were enrolled. General information, medical records and preoperative laboratory examination results of the patients were collected. According to the results of Doppler ultrasonography for the lower extremities, the patients were divided into DVT group and non-DVT group. Univariate and multivariate logistic regression were used to identify independent risk factors for preoperative DVT in knee OA patients undergoing TKA.ResultsThe incidence of DVT before TKA was 6.85% (40 cases). The increase of ESR (Erythrocyte Sedimentation Rate), platelet crit, IL-6 (Interleukin-6), and PCT (Procalcitonin) were associated with the development of DVT before TKA. Factors as coronary heart disease (CHD), diabetes mellitus (DM), Chronic Kidney Disease (CKD), NLR (ratio of neutrophils to lymphocytes), lower limb venous blood stasis, the time from onset to admission, RBC, PLT were identified by multivariate logistic regression to be the independent risk factors for preoperative DVT in knee OA patients undergoing TKA.ConclusionsDM, CKD, CHD, increased in ESR, IL-6 and PCT, blood stasis of the lower extremities, increased in PLT, platelet crit and the time from onset to admission, decreased in RBC, were high risk factors for preoperative DVT in knee OA patients undergoing TKA.