A 15 to 17-year follow-up of the Kinemax total knee replacement

Background

There is a paucity of long-term data concerning the pre- and postoperative patient reported function of total knee replacement. The aim of this study was to determine the mortality, implant survivorship, patient reported function and satisfaction in a cohort of 114 patients, from a single centre, who received a Kinemax total knee replacement more than 15?years ago.

Post-operative drainage after cemented, hybrid and uncemented total knee replacement

We recorded the total and 8-hourly post-operative drainage of 100 consecutive total knee replacements (33 cemented, 35 hybrid and 32 uncemented). The cemented, hybrid and uncemented prostheses had mean total drainage of 745, 1035 and 1220 ml, respectively. The difference in drainage between cemented and both hybrid and uncemented was statistically significant (P<0.05 and P<0.001). A significantly higher percentage of drainage occurred in the first 8-h period in the hybrid and uncemented groups. Total drainage in the cemented group was lower, but occurred more slowly, with a significantly higher percentage of drainage in the 17–48-h post-operative period when compared with the uncemented group (P<0.05). Within the cemented group, posterior-stabilised implants drained significantly more than those with an AP-lipped tibial insert (P<0.05). This information has implications for planning of blood product usage and timing of drain tube removal.     

Wear debris-induced pseudotumour in a cemented total knee replacement

We present a case of wear debris-induced osteolysis around the tibial component of a cemented total knee replacement associated with an expansile pseudotumour in the head of the fibula.     

Causes of failure of the Kinemax Plus total knee replacement in the first five years

In order to investigate whether any single batch of polyethylene inserts was responsible for premature failure of total knee replacements (TKR), we performed a retrospective database review of 1133 consecutive primary Kinemax Plus TKR performed by 2 surgical teams between January 1992 and January 2001 at our institution. Cases re-operated in any way within 5 years of the index arthroplasty were identified, case notes studied and radiographs reviewed. The causes contributing to the premature failure of the implants were identified where possible and the polyethylene lot numbers were recorded. Nineteen cases were known to have been revised, 7 cases for deep infection of the prosthesis and 12 for aseptic failure. In 10 cases, an identifiable technical error had contributed to the early failure of the implant. In 4 of these cases, there was inadequate tissue balancing in patients with a significant pre-operative valgus deformity. In 2 cases, the tibial base plate was inserted in a varus mal-alignment. There was one extended tibial component, one internally rotated femoral component, one oversized femoral component and one femoral component with inadequate fixation. Two further cases failed aseptically, one with a fracture of the medial tibial plateau and one idiopathic. The lot numbers of the polyethylene inserts were all different. This study confirms that the premature failure rate of the Kinemax Plus TKR is low. Although a "bad batch" of polyethylene has been suggested as a cause for early failure in TKR, in this series, surgical error was the predominant cause.     

The effect of component malalignment on the clinical and radiological outcome of the Kinemax total knee replacement

Component angles of 198 Kinemax total knee replacements were measured from standard short leg radiographs. An ideal tibio-femoral angle of between 4 and 10 degrees of valgus was achieved in 64.6% of patients. After an average follow-up of 6.5 years (range 4.5 to 9.5), there was no significant difference between knees in acceptable and suboptimal alignment in terms of pre- and post-operative knee and function scores and prevalence of radiolucent lines. Varus placement of the tibial component was significantly more common by trainee surgeons (P<0.001).     

Flexion after total knee replacement. A comparison between the Medial Pivot knee and a posterior stabilised implant

A comparison was made between 261 knees replaced with the Medial Pivot arthroplasty and 288 replaced with the 913 posterior stabilised arthroplasty (PS knee). There was no significant difference in the flexion obtained at 12 months after surgery (111 degrees and 109 degrees , respectively). When the knees were grouped into preoperative flexion ranges, there was no significant difference between the two implants. Those knees with preoperative flexion up to 90 degrees gained most (mean 22.6 degrees and 19 degrees for the PS knee and Medial Pivot, respectively). Knees with a preoperative flexion of 125 degrees or greater lost flexion. Regression analysis of individual knees revealed a small (average 2.9 degrees ), but significant greater loss of flexion at 12 months after surgery in the Medial Pivot group, with increasing preoperative flexion (beta coefficient = 2.923, P = 0.007). Some knees in both groups which had less than average preoperative flexion lost rather than gained flexion. We attributed this to patient factors such as pain, swelling and poor compliance with rehabilitation. Although the Medial Pivot knee may have advantages in terms of contact area and kinematics we found no advantage in terms of postoperative flexion over our posterior stabilised knee.     

Age stratified,matched comparison of unicompartmental and total knee replacement

BackgroundUnicompartmental knee replacement (UKR) tends to provide better function but has a higher revision rate than total knee replacement (TKR). The aim was to determine if this occurred in all age groups.MethodsTwo large, non-registry, prospective cohorts with median 10-year follow-up (2252 TKR, 1000 medial UKR) were identified. All UKR met recommended indications. TKR with an inappropriate disease pattern for medial UKR were excluded. Knees were propensity score-matched within age-strata (< 60 years at operation, 60 to < 75, 75 +) and compared using Oxford Knee Score (OKS), Kaplan–Meier revision rates and a composite failure, defined as any of revision, reoperation or no improvement in OKS.ResultsOne thousand five hundred and eighty-two TKR and UKR were matched. Results are reported TKR vs UKR for ages < 60, 60 to < 75 and 75 +. Median 10-year OKS were 33 vs 45 (p < 0.001), 36 vs 42 (p < 0.001) and 36 vs 38 (p = 0.25). Ten-year revision rates were 11% vs 7%, 5% vs 5%, and 5% vs 10%, (none significant). The composite failures occurred 8%, 5% and 5% more frequently with TKR than UKR (none significant).ConclusionsIn this matched study UKR provided better functional outcomes in all age groups, particularly the young, and provided substantially more excellent outcomes. Although in older groups TKR tended to have a lower revision rate, in the young UKR had a lower revision rate. This was surprising and was perhaps because in this study UKR was, as recommended, only used for bone-on-bone arthritis, whereas in young patients it is widely used for early arthritis, which is associated with a high failure rate. This study supports the use of UKR with recommended indications, in all age groups.     

Implant fixation in knee replacement: Preliminary in vitro comparison of ceramic and metal cemented femoral components

Improved wear resistance in total knee replacement (TKR) is a suitable goal. Whereas the use of metal components is well established, mechanical loosening in recently introduced ceramic components are a cause of concern. The scope of this work was to test in vitro whether ceramic TKR femoral components are more prone to mechanical loosening than metal ones. Composite femurs were implanted with commercially available TKR metal components, and with ceramic components having identical shape to the metal ones. Implanted femurs were tested on a knee simulator for up to 5 × 10^–6 cycles. Inducible micromotions and permanent migrations were recorded throughout the test. The cement layers were inspected for signs of damage or fracture. Micromotions and migrations were similar for metal and ceramic components: their magnitude and trend over time indicated that no implant was becoming loose. When there were statistically significant differences, the ceramic components were more stable than the metal ones. When the cement layers were inspected, a few short cracks were observed; most such cracks appeared during the first cycles, while no further damage occurred in the rest of the test. The type of damage found for both the metal and the ceramic components is compatible with well-fixed implants after long-term cycling. Altogether, no remarkable difference was found between the metal and ceramic components. Therefore, this study rejects the hypothesis that ceramic TKR femoral components are more prone to mechanical loosening. Although this study had a limited sample size, it provides novel pre-clinical indications about the potential of ceramic TKR femoral components.     

Bone ingrowth and total knee replacement

Biological fixation by bone ingrowth into prosthetic components in total knee arthroplasty is a complex process involving the integration of numerous biological and mechanical factors. These factors include the presentation of an appropriate porous-coated surface of such pore size and pore geometry as to allow bone ingrowth. Additionally, there must be intimate contact and minimal interface motion between the prosthesis and the bone for ingrowth to occur. Numerous factors have been shown to influence bone ingrowth including various types of bone graft material, electrical stimulation, drugs and ionizing radiation. The application of ingrowth biology to total knee arthroplasty technology has unique implications for the patellar, femoral and tibial prosthetic components. While the early clinical and retrival results of total knee arthroplasty using bio-ingrowth technology were somewhat controversial, more recent reports have been more favourable. As more clinical, basic science and retrieval studies become available in the 1990s the role of bio-ingrowth technology in the clinician's armamentarium will be further elucidated.     

Early post-operative opioid consumption: A comparison between medial unicompartmental,patellofemoral, and total knee arthroplasty

BackgroundWhile there is emerging literature describing the use of narcotics for post-operative pain control following TKA, little data is available regarding narcotic use in partial knee replacements. The aim of this study is to compare the early post-operative narcotic requirements after medial compartmental arthroplasty (UKA) and patellofemoral arthroplasty (PFA) with that of TKA.MethodsIn this retrospective chart review, we identified 37 patients who underwent PFA and 71 patients who underwent UKA. We identified a cohort of TKA patients who were matched to the unicompartmental group based on sex and age (n = 108). The primary outcome measure was self-reported use of opioids for pain management at the first post-operative clinic visit. Opioid use between groups was compared using Chi-square analysis.ResultsThe PFA group was younger (p < 0.001) and consisted of more females (p < 0.001) than the UKA group. The UKA cohort had more non-smoking patients (p = 0.044) compared to the PFA cohort. Self-reported opioid use at the first post-operative visit differed between the three groups of patients (p < 0.001). A greater proportion of both PFA (38% vs. 11%; p < 0.001) and TKA (41% vs. 11%; p = 0.01) patients reported opioid use when compared to UKA patients. No differences in opioid use existed between TKA and PFA groups (p = 0.61).ConclusionThe prevalence of PFA patients who report opioid use at the first post-operative visit is similar to that for patients following TKA, suggesting that pain management protocols for this specific subset of partial knee arthroplasty patients should be structured similar to TKA patients and separate from UKA patients.     

Deprivation and outcome of total knee replacement

Deprivation correlates with poor health and psychosocial variables can affect the symptoms of knee arthritis. Our aim was to determine the effect of deprivation on the level of knee function and health-related quality of life at the time of arthroplasty and 12 months after total knee replacement. From our database of over 2500 knee replacements, we analysed both clinical and quality of life outcome measures. We analysed the relationship between deprivation (by Townsend score), knee function (Knee Society Score) and health-related quality of life (Nottingham Health Profile) before total knee replacement (TKR) and at 12 months post-operation. There was no significant correlation between Townsend score, Knee Society Score and Nottingham Health Profile preoperatively or at 12 months after knee replacement, thus showing that there was no association between deprivation and the severity of knee arthritis at the time of joint replacement nor was there a relationship between deprivation and the short-term outcome from total knee replacement.     

The role of the cemented all-polyethylene tibial component in total knee replacement: A 30-year patient follow-up and review of the literature

Use of an all-polyethylene tibial component in primary total knee arthroplasty remains an attractive option considering the reported durability of the construct, the lowered cost compared to modular metal-backed tibia, and the elimination of backside wear. The two major intra-operative disadvantages include the inability to alter the tibial component thickness after permanent implant placement and the inability to use varus-valgus constrained designs. The long-term disadvantage is the inability to perform a modular insert exchange should this be required. We report the 30-year outcome of a single patient using the duopatellar total knee replacement system. Based on a critical review of the literature we would recommend use in patients 80 years of age or older, consideration in patients 75 to 79 years, and possibly in younger yet less active patients. These three groups would be the least likely to require a modular tibial liner exchange in their lifetime.     

Brucellar prosthetic arthritis in a total knee replacement

The infecting pathogens most commonly implicated in prosthetic joint infections are staphylococci, streptococci, and gram-negative rods. Prosthetic infections caused byBrucella spp, are rarely described in the literature. Treatment of prosthetic infections remains complex and controversial, the most accepted course being antibiotic treatment with removal or retention of prosthetic components. The case of a 60-year-old man who developedBrucella septic arthritis of the right knee in a total knee replacement is reported. Conservative treatment using a three-drug therapy was employed, with excellent results.     

Postoperative alignment in revision total knee arthroplasty,a comparison between intra and extra-medullary tibial alignment

BackgroundRevision total knee arthroplasty commonly involves stemmed components. If the diaphysis is engaged, this technique may be problematic for mechanical alignment (MA) in cases of tibial bowing, which are not infrequent (up to 30%).The aim of this study is to compare an intra-medullary(IM) and extra-medullary(EM) alignment method. We hypothesized that IM technique and canal-filling stems may result more frequently in valgus MA. On the other hand, an EM technique could produce less valgus knees but is at risk of creating MA outliers.MethodA retrospective radiographic analysis of revision TKAs was performed. The patients were divided to either the EM or IM alignment group and compared on the overall post-operative MA. The following parameters were measured on standing, long leg x-rays: Hip-knee-Ankle angle (HKA), mechanical lateral distal femoral angle and mechanical medial proximal tibial angle (mMPTA).Results119 cases of revision TKAs were included (EM = 80, IM = 39). There was a difference between the EM and IM group for the mean mMPTA (89.94° vs 90.92°, effect size = 0.45, p = 0.013) and HKA angle (1.64° vs 0.05°, effect size = 0.52, p = 0.0064). A higher proportion of IM patients were in overall valgus alignment (16/39, 41%) vs EM group (16/80, 20%, p = 0.0134). Both techniques showed the same proportion of outliers, defined as HKA angle more than 5 degrees from neutral mechanical alignment (11/80 vs 5/39, p = 0.286).ConclusionThe extra-medullary alignment method with short cemented stems creates less valgus mechanical alignment than the intra-medullary technique with press-fit stems, without creating more MA outliers.     

Topical tranexamic acid in total knee replacement: A systematic review and meta-analysis

BackgroundTo examine the safety and efficacy of topical use of tranexamic acid (TA) in total knee arthroplasty (TKA).MethodsAn electronic literature search of PubMed Medline; Ovid Medline; Embase; and the Cochrane Library was performed, identifying studies published in any language from 1966 to February 2013. The studies enrolled adults undergoing a primary TKA, where topical TA was used. Inverse variance statistical method and either a fixed or random effect model, depending on the absence or presence of statistical heterogeneity were used; subgroup analysis was performed when possible.ResultsWe identified a total of seven eligible reports for analysis. Our meta-analysis indicated that when compared with the control group, topical application of TA limited significantly postoperative drain output (mean difference: ? 268.36 ml), total blood loss (mean difference = ? 220.08 ml), Hb drop (mean difference = ? 0.94 g/dL) and lowered the risk of transfusion requirements (risk ratio = 0.47, 95CI = 0.26–0.84), without increased risk of thromboembolic events. Sub-group analysis indicated that a higher dose of topical TA (> 2 g) significantly reduced transfusion requirements.ConclusionsAlthough the present meta-analysis proved a statistically significant reduction of postoperative blood loss and transfusion requirements with topical use of TA in TKA, the clinical importance of the respective estimates of effect size should be interpreted with caution.Level of evidenceI, II.     

Conversion total knee arthroplasty: A case complexity between primary and revision total knee arthroplasty

BackgroundConversion total knee arthroplasty (TKA) may represent a more complex procedure compared with primary TKA. The purpose of this study was to compare 30-day complications between conversion TKA and primary, non-conversion TKA as well as between conversion TKA and revision TKA on a national scale using a multi-center surgical registry.MethodsAdult patients undergoing conversion TKA from 2006 to 2018 were identified in the National Surgical Quality Improvement Program database and were compared with patients who underwent primary TKA and aseptic revision TKA. In this analysis, 30-day complications were assessed. Bivariate analyses, including chi-squared and analysis of variance, and multivariate logistic regressions were performed.ResultsOf 299,065 total patients undergoing knee arthroplasty, 1,310 (0.4%) underwent conversion TKA, 275,470 (92.1%) underwent primary TKA, and 22,285 (7.5%) underwent revision TKA. Following adjustment, patients who underwent conversion TKA were more likely to have increased risks of any complications (P < 0.001), mortality (P = 0.021), wound complications (P < 0.001), cardiac issues (P = 0.018), bleeding requiring transfusion (P < 0.001), and reoperation (P = 0.002) relative to primary TKA patients. Compared with patients who underwent revision TKA, conversion TKA patients were less likely to have septic complications (P = 0.009).ConclusionConversion TKA is associated with significantly higher rates of complications compared with primary, non-conversion TKA, but less risk of sepsis compared with revision TKA. Because current reimbursement classifications do not account for the case complexity of a conversion TKA, new classifications should be implemented with reimbursements for conversion TKA approximating reimbursements for revision TKA.     

Metallosis in cemented titanium alloy total knee arthroplasty without apparent metal-on-metal articulation

Background

Metallosis is an uncommon phenomenon observed in late failures of cemented total knee arthroplasty (TKA), and it is rarely seen in the absence of metal-on-metal articulation.

Accuracy of patellar resection in total knee replacement. A study using the medial pivot knee

A series of 80 patellae were randomly allocated to osteotomy by sawing or milling while implanting the medial pivot knee. Three landmarks were used to control the plane of the cut in the coronal plane. The lateral edge of the patellar tendon distally, and both medial and lateral edges of the quadriceps tendon proximally. A line drawn across the widest points if the patella (the patellar horizon) was used to analyse the slope of the cut (P angle) and the orientation of the patella relative to the trochlear groove both pre- and post-operatively (PF angle) on 45 degrees skyline views. No patellae were under resected. The mean thickness of the remnant was 16 mm (range 14-19).There was no difference between sawing and milling, but the former was technically preferable. No patellae were found to be subluxed. The mean P angle was 2 degrees (S.D. 3.2). The maximum P angle was 10 degrees , but in no cases did obliquity of cut with under resection of the medial patellar facet lead to lateral tilt of the patellar horizon. The mean post-operative PF angle was 2.3 degrees (S.D. 2.6). The majority of patellae retained a similar orientation to the patellar groove post-operatively. In three patients, the patella tilted laterally with respect to the groove. One resulted from under resection of the lateral patellar facet and two in which the slope of the cut was good, probably resulted from an error in femoral rotation. In all 80 knees, the patellar dome remained in full contact with the groove. Use of three fixed landmarks provides consistent patellar resection in terms of depth and slope. Errors in slope of up to 10 degrees do not cause patellar tilt but may lead to medial overload due to increasing thickness of the patella. Errors in femoral sizing and rotation are more potent causes of lateral tilt and overload.     

Glomus tumour following a total knee replacement: A case report

Pain following total knee replacement (TKR) is a common problem and cause of poor satisfaction amongst patients. We report on a glomus tumour causing pain on the anterolateral aspect of the knee, 2 years after an otherwise successful total knee replacement for osteoarthritis. The tumour was treated by excision biopsy under general anaesthesia and the diagnosis confirmed by histopathological examination. The removal of the tumour relieved the pain and the patient regained good function. We conclude that a thorough clinical assessment of a patient with a painful knee following TKR is essential to detect and treat coincidental painful pathology.