Causes of a painful total knee arthroplasty. Are patients still receiving total knee arthroplasty for extrinsic pathologies?

Purpose

Whilst patients undergoing total knee replacements generally have good relief of their symptoms, up to 20% complain of persisting pain. Revision rates have therefore been rising, particularly so for unexplained pain. We reviewed the causes of painful total knee replacements including extrinsic causes.

Methods

Forty-five consecutive patients referred to our department with painful total knee replacement were reviewed with our standard protocol, including history and examination, inflammatory markers and radiological studies including radiographs of the hip and knee and computed tomography scan of the knee joint.

Results

Of the 45 patients, 15 patients had degenerative hip and lumbar spine disease which resolved after injections of the relevant joints. Nine patients had unexplained pain.

Conclusions

Patients may still be undergoing knee arthroplasty for degenerative lumbar spine and hip osteoarthritis. We suggest heightened awareness at pre- and post-operative assessment and thorough history and examination with the use of diagnostic injections to identify the cause of pain if there is doubt.     

Do patients need to earn total knee arthroplasty?

Traditional orthopaedic thinking dictates that performing total knee arthroplasty (TKA) in patients with relatively early stages of osteoarthritis (OA) will lead to a poor outcome. Our goal was to test this perception, using radiologic parameters as a marker of the degree of OA. Our study involved 130 consecutive patients who underwent TKA for OA. The radiographs of each patient were graded according to the Ahlback classification. Outcome was measured prospectively using the Oxford Knee Score (OKS), which was recorded both preoperatively and 1 year after surgery. The degree of radiologic OA changes preoperatively was not found to influence the outcome of surgery at 1 year, with all patient groups improving to a similar extent. In addition, as has been seen in previous studies, no correlation was found between symptoms of OA and radiologic appearances. The results of this study would support a re-evaluation of traditional orthopaedic practice. This conclusion coincides with other recent work that suggests that TKA is underused and is performed too late in the natural history of OA of the knee.     

Is decreasing mortality in total hip and knee arthroplasty patients dependent on patients’ comorbidity?

Background and purpose — Mortality after primary total hip and knee arthroplasty (THA and TKA) has declined, and the proportion of THA and TKA patients with comorbid conditions has increased. We therefore wanted to examine changes in comorbidity burden over time and the impact of comorbid on mortality following primary total hip and knee arthroplasty in patients with osteoarthritis.

Patients and methods — We used the Danish arthroplasty registers to identify THA and TKA patients from 1996 through 2013. From administrative databases, we collected data on pre-surgery hospital history for all patients, which were used to calculate the Charlson comorbidity index (CCI). Patients were divided into 4 groups: CCI-none, CCI-low, CCI-moderate, and CCI-high. We calculated the relative risk (RR) of mortality within 90 days after surgery with a 95% confidence interval (CI), with stratification according to CCI group and year of surgery.

Results — 99,962 THAs and 63,718 TKAs were included. The proportion of THAs with comorbidity increased by 3–4% in CCI-low, CCI-moderate, and CCI-high patients, from 1996–1999 to 2010–2013. The overall 90-day mortality risk declined for both procedures. Compared to CCI-none, THA patients with low, moderate, and high comorbidity burdens had an RR of 90-day mortality of 1.9 (95% CI: 1.6–2.4), 1.9 (CI: 1.5–2.5), and 3.3 (CI: 2.6–4.2), respectively. Similar increases in proportions and RRs were observed in TKAs.

Interpretation — Despite the fact that the proportion of THA and TKA patients with comorbidities has increased over the past 18 years, the overall mortality has declined. The mortality risk depended on the comorbidity burden and did not decline during the study period for THA and TKA patients with a moderate or high comorbidity burden at the time of surgery.     

Rheumatoid arthritis: a risk factor for deep venous thrombosis after total knee arthroplasty? Comparative study with osteoarthritis

Background  

Recent advances in the understanding of blood coagulation processes favor an inflammatory basis for thrombotic events. In this study, thrombotic risk after total knee arthroplasty (TKA) was assessed and compared between patients with rheumatoid arthritis (RA) and those with osteoarthritis (OA).     

Is extreme flexion of the knee after total knee replacement a prerequisite for patient satisfaction?

The focus of this study was to evaluate the functional result and to specifically ascertain whether the absence of the ability to squat and sit cross-legged altered the patient's satisfaction level after a successful standard total knee replacement. Squatting and sitting cross-legged are common practices in Asia. These activities are not possible following standard total knee replacement. Patients were followed-up for a minimum of 12 months post surgery. Their level of satisfaction was assessed using a Likert scale. The Knee Society Score (KSS) was used to assess range of motion and function of the knee. Twenty-one out of 25 patients were satisfied with the surgical result in spite of an inability to squat. Deep knee flexion may not be an essential prerequisite for patient satisfaction after total knee replacement, even in a population where squatting and sitting cross-legged are part of the normal lifestyle.     

Wear in total knee arthroplasty—just a question of polyethylene?: Metal ion release in total knee arthroplasty

Purpose

Biological reactions against wear particles are a common cause for revision in total knee arthroplasty. To date, wear has mainly been attributed to polyethylene. However, the implants have large metallic surfaces that also could potentially lead to metal wear products (metal ions and debris). The aim of this study was to determine the local release of cobalt, chromium, molybdenum and titanium in total knee arthroplasty during a standard knee wear test.

Methods

Four moderately conforming fixed-bearing implants were subjected to physiological loadings and motions for 5×10⁶ walking cycles in a knee wear simulator. Polyethylene wear was determined gravimetrically and the release of metallic wear products was measured using high resolution-inductively coupled plasma-mass spectrometry.

Results

A polyethylene wear rate of 7.28 ± 0.27 mg/10⁶ cycles was determined and the cumulative mass of released metals measured 1.63 ± 0.28 mg for cobalt, 0.47 ± 0.06 mg for chromium, 0.42 ± 0.06 mg for molybdenum and 1.28 ± 0.14 mg for titanium.

Conclusion

For other metallic implants such as metal-on-metal total hip arthroplasty, the metal wear products can interact with the immune system, potentially leading to immunotoxic effects. In this study about 12 % by weight of the wear products were metallic, and these particles and ions may become clinically relevant for patients sensitive to these materials in particular. Non-metallic materials (e.g. ceramics or suitable coatings) may be considered for an alternative treatment for those patients.     

Bicruciate-retaining total knee arthroplasty: What’s new?

Primary total knee arthroplasty(TKA) is a widespread procedure to address end stage osteoarthritis with good results, clinical outcomes, and long-term survivorship. Although it is frequently performed in elderly, an increased demand in young and active people is expected in the next years. However, a considerable dissatisfaction rate has been reported by highly demanding patients due to the intrinsic limitations provided by the TKA. Bicruciate-retaining(BCR) TKA was developed to mimic knee biomechanics, through anterior cruciate ligament preservation. First-generation BCR TKA has not gained popularity due to its being a challenging technique and having poor survival outcomes. Thanks to implant design improvement and surgeon-friendly instrumentation, secondgeneration BCR TKA has seen renewed interest. This review will focus on surgical indications, kinematical basis, clinical results and latest developments of secondgeneration BCR TKA.     

Which do patients prefer,unicompartmental or total knee arthroplasty?

Objective

Unicompartmental knee arthroplasty (UKA) is a viable option for relieving pain and improving function in patients with isolated compartment knee osteoarthritis (OA). Certain surgeons prefer total knee arthroplasty (TKA) over UKA even when patients are candidates for UKA. Therefore, the decision to perform a UKA or a TKA when both are indicated is not straightforward. The goal of this study was to compare pre-operative and post-operative patient-reported outcome (PRO) scores for patients who underwent both a UKA and a contralateral TKA.

Patella in total knee arthroplasty: to resurface or not to��a cohort study of staged bilateral total knee arthroplasty

The aim of this study was to assess medium term results of patellar resurfacing in total knee arthroplasty, specifically looking at anterior knee pain, patellofemoral function and need for reoperation. A prospective cohort study was conducted with patients undergoing staged bilateral knee arthroplasty with the patella being resurfaced only on one side. This was due to change in the clinical practice of the senior author. Sixty patients were reviewed clinically and radiologically on a regular basis. The surgery was either performed or supervised by the senior author in all cases. All patients received the cemented press-fit condylar© prosthesis. The Knee Society clinical rating system was used. Scores were recorded pre-operatively and post-operatively at three months, one year, two years and three yearly thereafter. The mean age of patients in the study group was 75 years (range: 62–89 years). There were 42 women and 18 men in the study. The mean duration of follow-up was 4.5 years (range: 2–12 years). There was no significant difference in the pre-operative scores in both groups. There were significantly better scores (p < 0.05) on the resurfaced side as compared to the non-resurfaced side at final follow-up. No revision was carried out for patellofemoral complications on the resurfaced side. Four patients required revision in the form of patellar resurfacing on the non-resurfaced side for persistent anterior knee pain. Patellar resurfacing is recommended in total knee arthroplasty for better functional outcome with regards to anterior knee pain and patellofemoral function.     

Brake response time after total knee arthroplasty: when is it safe for patients to drive?

Total knee arthroplasty (TKA) dramatically decreases pain and improves mobility and quality of life. However, little has been reported on its effect on driving ability in the early postoperative period. This prospective study was conducted to compare preoperative and postoperative brake response times (BRTs) in patients undergoing TKA for osteoarthritis. The results showed that patients returned to preoperative BRT as early as 3 weeks after surgery, and at 9 weeks after surgery, BRTs were significantly improved over baseline. Based on BRT analysis patients undergoing TKA may be allowed to return to driving 6 weeks after surgery.     

Do manual cutting guides for total knee arthroplasty introduce systematic error?

Introduction

Conventional cutting guides in total knee arthroplasty can potentially cause unintentional deviation from the planned direction and depth of bone resection resulting in malaligned components. The purpose of this study was therefore to investigate the accuracy of bone cutting jigs for both the femur and tibia using imageless navigation.

Material and methods

A total of 125 patients with a mean age of 66.7?±?9.9 years underwent primary total knee arthroplasty with a Stryker Triathlon? fixed bearing posterior cruciate retaining implant using imageless navigation. Coronal and sagittal position of the secured cutting jig was recorded and bone resection was checked with a rectangular probe attached to a navigation tracker.

Results

There were significant within group differences for the femoral sagittal cut (mean δ?=?0.9° [31 %]; p?=?0.00001), femoral depth medial compartment (mean δ?=?0.5 mm [5 %]; p?=?0.001), femoral depth lateral compartment (mean δ?=?0.7 mm [7 %]; p?=?0.00001), proximal tibial cut (mean δ?=?0.3 mm [25 %]; p?=?0.001), tibial depth medial compartment (mean δ?=?0.6 mm [10 %]; p?=?0.0001) and tibia depth lateral cut (mean δ?=?0.4 mm [5 %]; p?=?0.002). Deviation of more than 2° was observed for the distal cut in the sagittal plane in 17 % and in 9.6 % for the proximal tibial cut in the sagittal plane of all patients.

Conclusion

The results of this study demonstrated significant differences between the dialed in cut and “actual” bone resection achieved for all planes for both the femur and tibia. The femur sagittal cut demonstrated a tendency for an extended cut and the tibia showed a tendency for varus.

     

Techniques for extensor mechanism reconstruction after total knee arthroplasty: Is there a clear winner?

Extensor mechanism (EM) disruption after total knee arthroplasty (TKA) is rare, but can result in devastating outcomes for patients including inability to ambulate. Disruption can occur at the quadriceps tendon, patella, or patellar tendon. This complication can be traumatic, but is often atraumatic from an iatrogenic or degenerative etiology. Primary repair for treatment of EM disruption has led to poor results with high failure rates and has mostly been abandoned. Most commonly accepted techniques center around Achilles tendon allograft reconstruction, synthetic mesh reconstruction, or other smaller options.However, to date, there is still no consensus for the optimal EM reconstructive technique due to the heterogeneity and small sample sizes of published studies. The need to identify a consistent and effective surgical technique is paramount to restore quality of life to patients who suffer from EM disruption after TKA. The purpose of this review is to describe the osteology, vasculature, and EM of the knee, identify risk factors associated with EM disruption after TKA, outline the considerations for surgical management, as well as compare and analyze the latest contributions to the literature, in particular allograft versus synthetic mesh, in the reconstruction of the EM after TKA.     

Blood management for patients with hemoglobin level lower than 130 g/l in total knee arthroplasty

Introduction The risk of requiring allogeneic blood transfusion after total knee arthroplasty has been recently decreased with several methods such as blood donation, blood salvage, and hematinic. For patients with a low baseline hemoglobin level, however, the rate of allogeneic transfusion is still high, and an effective method for avoiding allogeneic blood transfusion has not been established. We introduced intra- and postoperative blood salvage with the Cell Saver for patients with a baseline hemoglobin level lower than 130 g/l and analyzed the frequency of allogeneic blood transfusion.Materials and methods From 1993 to 1997, 218 consecutive total knee arthroplasties were performed, and 155 knees with baseline hemoglobin lower than 130 g/l were included in this study. Baseline hemoglobin ranged from 62 to 129 g/l, with a mean of 110 g/l. All patients were managed with intra- and postoperative blood salvage with the Cell Saver. Preoperative autologous blood donation and/or use of hematinic was performed for 129 knees (group 1) and was not performed for 26 knees (group 2). There were no significant differences between the two groups with regard to preoperative factors. To examine the role of perioperative factors (age, sex, baseline hemoglobin level, revision procedure, preoperative blood donation, and use of hematinic) in determining the requirements for allogeneic transfusion, backward elimination logistic regression analysis was used.Results Seven knees (4.5%) required allogeneic transfusion. Group 1 (2.3%) exhibited a lower rate of allogeneic blood transfusion than group 2 (15.4%) (p=0.016). Hemoglobin levels on the day (p=0.016), 1 week (p=0.0001), and 2 weeks (p=0.007) after surgery were lower in group 1 than in group 2. Backward elimination logistic regression analysis showed that preoperative blood donation (p=0.048) and use of hematinic (p=0.040) were significantly associated with a requirement for allogeneic blood transfusion.Conclusion Preoperative blood donation and use of hematinic were associated with a low incidence of allogeneic blood transfusion after total knee arthloplasty with intra- and postoperative blood salvage, even for patients with a baseline hemoglobin level below 130 g/l.     

Continuous femoral nerve block after total knee arthroplasty?

Background: A continuous femoral nerve block is frequently used as an adjunct therapy after total knee arthroplasty (TKA). However, there is still debate on its benefits.
Methods: In this prospective, randomized study, patients received a basic analgesic regimen of paracetamol and dicloflenac for the first 48 h postoperatively. In addition, the study group received a continuous femoral nerve block. A morphine patient-controlled analgesia pump was also available as a rescue analgesic to all the patients. Patients' numeric rating scores for pain, the amount of morphine consumed and its side effects during the first 48 h were recorded. Knee flexion angles achieved during the first week were registered. Three months postoperatively, patients completed Western Ontario and McMaster Universities Osteoarthritis Index and Knee Society Score.
Results: The study group ( n =27) had less pain ( P =0.0016) during the first 48 h, was more satisfied with the analgesia ( P <0.001) and used less morphine ( P =0.007) compared with the control group ( n =26). Fewer patients were nauseated, vomited or were drowsy in the study group ( P =0.001). Also, the study group achieved better knee flexion in the first 6 days after surgery ( P =0.001), with more patients reaching 90° flexion than the control group. However, after 3 months, there were no significant functional differences between the groups.
Conclusion: A continuous femoral nerve block leads to better analgesia, less morphine consumption and less morphine-related side effects after TKA. Early functional recovery is improved, resulting in more patients reaching 90° knee flexion after 6 days. However, after 3 months, no significant functional benefits were found.     

Are surgeons equally satisfied after total knee arthroplasty?

Introduction We performed a clinical follow-up study to investigate whether three orthopaedic surgeons were equally satisfied after total knee arthroplasty (TKA).Patients and methods Thirty-six patients (39 TKAs, mean follow-up 12 months) were reviewed, using the Knee Society Clinical Rating System (KSCRS). For the assessment of satisfaction a visual analogue scale (VAS) was used.Results We did not find a significant difference in satisfaction between the surgeons. However, there was a significant difference in the knee score and function score of the KSCRS as evaluated by the orthopaedic surgeons (p=0.006 and p=0.04, respectively). The correlation between the knee score and the surgeons satisfaction was high, which indicates that pain, range of motion and deformity are important success criteria for surgeons.Conclusions In this study, surgeons scored differently in the KSCRS but were equally satisfied after TKA.