A Mid-term Comparison of the Functional Outcomes of Medial Pivot and Rotating Platform Mobile-Bearing Total Knee Arthroplasty in the Indian Population

BackgroundBoth medial pivot (MP) and rotating platform (RP) mobile-bearing (MB) total knee arthroplasty (TKA) have been developed to better mimic the natural knee kinematics and femoral roll back in flexion. The purpose of this retrospective study was to compare the mid-term functional outcomes and range of motion (ROM) of MP and RP types of total knee arthroplasty.Methods116 patients (mean age of 66.3 years) undergoing TKA (52 Medial pivot design and 64 Rotating Platform design) were evaluated retrospectively with Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) knee score, knee society score (KSS) with its subgroups namely, Knee Score (KSKS) and Functional Score (KSFS) and forgotten joint score (FJS) at a mean follow-up of 7.1 years. Range of motion (ROM) and tibiofemoral anatomic angle on the radiographs were also compared.ResultsMean ROM, WOMAC and KSKS improved significantly from pre-operative to postoperative knees in both the groups. There was, however, no significant difference between the two groups at the final follow-up. In contrast, mean KSFS score improved to 89.5 ± 8.1 in MP group and 86.3 ± 7.1 in RP Group (p = 0.025), while mean FJS was 85.6 ± 4.1 and 80.9 ± 5.4 in the MP and RP groups, respectively (p = < 0.0001).ConclusionSatisfactory clinical and functional outcomes can be obtained using either a MP or RP knee joint in tricompartmental osteoarthritis of knee. The MP design scores better on the KSFS score and FJS than the RP-TKA.     

Outcome of Revision Surgery for the Idiopathic Stiff Total Knee Arthroplasty

BackgroundIdiopathic stiff total knee arthroplasty (TKA) represents one of the most challenging subsets of the stiff TKA, as the etiology is unknown and there is no consensus on the most appropriate surgical treatment modality. Therefore, the aim of this study is to report on postoperative outcomes of revision surgery for idiopathic stiff TKA.MethodsWe retrospectively reviewed 189 consecutive patients (202 knees) who underwent revision TKA for stiffness: (1) 101 knees in the idiopathic stiffness cohort and (2) 88 in the non-idiopathic stiffness cohort. In the idiopathic stiffness cohort, 42 knees underwent isolated tibial insert exchange and 59 knees underwent component revision. Perioperative knee range of movement and complications were analyzed.ResultsThe overall revision surgery outcomes of the idiopathic stiffness cohort were worse than those of the non-idiopathic stiffness cohort with regard to maximum flexion (91.7° vs 100.1°, P = .02) and flexion range of motion (ROM) (87.6° vs 97.1°, P = .01). In the idiopathic stiffness cohort, isolated tibial insert exchange demonstrated greater maximum flexion (96.8° vs 88.4°, P = .06) and flexion ROM (93.2° vs 83.9°, P = .07). In terms of re-revision rates, the isolated tibial insert exchange idiopathic stiffness cohort demonstrated lower re-revision rates compared to the component revision idiopathic stiffness cohort (16.7% vs 31.0%, P = .01).ConclusionThis study demonstrates that the overall revision surgery outcome of idiopathic stiff TKA is worse than non-idiopathic TKA stiffness. In idiopathic stiffness cohorts, isolated tibial insert exchange was associated with lower re-revision rates than component revision, with similar efficacy in improving ROM, suggesting that isolated tibial insert exchange may be a preferred surgical treatment option in TKA patients with idiopathic stiffness.     

Clinical Outcomes in Isolated Tibial Revision With Cruciate Retaining Total Knee Arthroplasty

BackgroundTibial component loosening is one of the most common modes of failure in contemporary total knee arthroplasty (TKA). Limited literature is available on the outcomes of isolated tibial revision with retention of the cruciate retaining (CR) femoral component. The purpose of this study was to determine the results of isolated tibial revisions in CR TKA.MethodsWe identified 135 patients who underwent an isolated tibial revision after a primary CR TKA from our institutional registry between January 2007 and January 2017. The mean time between the primary and revision was 2.9 years (range 0.1-15.4). Revision with a press-fit stem was performed in 79 patients and 56 patients were revised with a fully cemented stem. Patients were evaluated at a minimum of two years using Knee Society Score, Knee Injury and Osteoarthritis Score for Joint Replacement, and radiography. Implant survivorship was determined using Kaplan-Meier survival analysis.ResultsAt a mean follow-up of 5.1 years, there were six (4.4%) repeat revisions: three for periprosthetic infection (2.2%), two for instability (1.5%), and one for a fractured tibial stem (0.7%). The mean Knee Society Score and Knee Injury and Osteoarthritis Score for Joint Replacement increased from 51.6 and 56.1 preoperatively to 90.1 and 89.7 after surgery (P < .001). Survivorship free of repeat revision for any cause was 93.3% at 5 years, and aseptic revision survivorship was 95.8% at 5 years. No implants were radiographically loose.ConclusionIn patients with isolated tibial loosening and a well-fixed and well-positioned CR femoral component, isolated tibial revision provides excellent early to midterm implant survivorship and clinical outcomes with a low risk of instability and recurrent tibial loosening.     

Clinical results of isolated tibial component revisions with femoral component retention

The purpose of this study is to report the outcome for a consecutive series of isolated nonmodular tibial component revisions. A consecutive series of 6548 total knee arthroplasties (6024 metal backed; 524 all-polyethylene) were performed with nonmodular tibial components of which 54 knees (0.82%) (22 metal backed; 32 all-polyethylene) underwent isolated tibial component revision with femoral component retention. Clinical outcome and component survivorship were examined. Pain scores improved from 19 to 42 points and Knee Society score improved from 62 to 87 points after revision. At a mean of 6.6-year follow-up, the survivorship of the revised tibial components and retained femoral components, with aseptic loosening as the end point, was 100%.     

Isolated Versus Full Component Revision in Total Knee Arthroplasty for Aseptic Loosening

BackgroundRevision of both femoral and tibial components of a total knee arthroplasty (TKA) for aseptic loosening has favorable outcomes. Revision of only one loose component with retention of others has shorter operative time and lower cost; however, implant survivorship and clinical outcomes of these different operations are unclear.MethodsBetween January 2009 and December 2019, a consecutive cohort of revision TKA was reviewed. Univariate and multivariable analyses were used to study correlations among factors and surgical related complications, time to prosthesis failure, and functional outcomes (University of California Los Angeles, Knee Society functional, knee osteoarthritis and outcome score for joint replacement, Veterans RAND 12 (VR-12) physical, and VR-12 mental).ResultsA total of 238 patients underwent revision TKA for aseptic loosening. The mean follow-up time was 61 months (range 25 to 152). Ten of the 105 patients (9.5%) who underwent full revision (both femoral and tibial components) and 18 of the 133 (13.5%) who underwent isolated revision had subsequent prosthesis failure [Hazard ratio (HR) 0.67, P = .343]. The factor analysis of type of revision (full or isolated revision) did not demonstrate a significant difference between groups in terms of complications, implant failures, and times to failure. Metallosis was related to early time to failure [Hazard ratio 10.11, P < .001] and iliotibial band release was associated with more complications (Odds ratio 9.87, P = .027). Preoperative symptoms of instability were associated with the worst improvement in University of California Los Angeles score. Higher American Society of Anesthesiologists status and higher Charlson Comorbidity Index were related with worse VR-12 physical (?30.5, P = .008) and knee osteoarthritis and outcome score for joint replacement (?4.2, P = .050) scores, respectively.ConclusionIsolated and full component revision TKA for aseptic loosening does not differ with respect to prosthesis failures, complications, and clinical results at 5 years. Poor American Society of Anesthesiologists status, increased comorbidities, instability, and a severe bone defect are related to worse functional improvement.Level of evidenceIII, cohort with control.     

High Incidence of Tibial Component Loosening After Total Knee Arthroplasty Using Ceramic Titanium-Nitride-Coated Mobile Bearing Prosthesis in Moderate to Severe Varus Deformity: A Matched-Pair Study Between Ceramic-Coated Mobile Bearing and Fixed Bearing Prostheses

BackgroundWe compared the incidence of aseptic component loosening and subsequent revision, and the survival rate between ceramic titanium-nitride-coated mobile bearing (MB) and fixed bearing total knee arthroplasties (TKAs) performed in patients with moderate to severe varus deformities.MethodsIn total, 200 TKAs using advanced coated system posterior stabilized prostheses in varus deformity of mechanical axis >8° between 2012 and 2016 were retrospectively reviewed. One hundred MB (ceramic-m group) and 100 fixed bearing (ceramic-f group) prostheses were included. The matches were made according to preoperative demographics, range of motion, and severity of deformity. The mean follow-up period was not different (ceramic-m vs ceramic-f = 4.8 vs 5.1 years; P = .104). The incidence of revision TKA due to aseptic component loosening and the survival rate (failure: revision due to aseptic loosening) was investigated.ResultsThe incidence of revision TKA due to aseptic component loosening was 7 (7%) in the ceramic-m group and 1 (1%) in the ceramic-f group (P = .032). All cases of aseptic loosening occurred at the tibial component. The overall survival rate was 91.3% in the ceramic-m group and 98.9% in the ceramic-f group (P = .025).ConclusionConsidering the higher revision incidence and lower survival rate due to tibial component loosening, caution should be taken in tibial component fixation when using advanced coated system MB prosthesis in moderate to severe varus deformity.Level of EvidenceIII     

Joint line and patellar height restoration after revision total knee arthroplasty

Background:

Restoration of proper joint line (JL) position and patellar height in revision total knee arthroplasty (TKA) is essential in the recovery of knee function and kinematics. We determined whether the JL position and patellar height could be restored in patients undergoing septic and aseptic revision TKA.

Materials and Methods:

We retrospectively reviewed 70 patients (74 knees) who had revision TKA between September 2004 and December 2010. Forty seven knees had a two stage revision for infected TKA and 27 knees for aseptic failure. The JL position, patellar height and patellar tendon (PT) length were measured and compared between primary TKA and post revision. The clinical scores including a hospital for special surgery (HSS), Knee Society Score (KSS), Western Ontario and McMaster Universities (WOMAC) and range of motion (ROM) were compared.

Results:

The overall JL increased from 17.51 mm to 18.37 mm post revision, the Insall-Salvati (IS) ratio declined from 0.98 to 0.92, and the PT length declined from 42.92 mm to 39.45 mm. 9 of the 21 patellar baja knees improved to normal patellar height. After revision, the JL in the septic group (17.02 mm) was significantly lower than the aseptic group (20.74 mm). The changes of the JL position and IS ratio in the septic group were significantly larger than the aseptic groups (P < 0.05). JL position had a positive correlation to the IS ratio and PT length post revision. The knee function scores including HSS, KSS, WOMAC scores, and ROM all improved post revision compared to pre revision (P < 0.05), and the septic group had a lower knee function compared to the aseptic group. JL position and IS ratio post revision had no correlation to the HSS, KSS, WOMAC scores, and ROM.

Conclusions:

JL position can be sufficiently restored with appropriate distal femoral augment reconstruction after revision TKA, but the patellar height cannot be well improved, especially in the septic revision with obvious PT contracture. No correlation was found between the JL position and patellar height to the knee function post revision TKA.     

Patient-Reported Outcomes and Satisfaction 1 to 3 Years After Revisions of Total Knee Arthroplasties for Unexplained Pain Versus Aseptic Loosening

BackgroundIt is unknown if patients are relieved of pain after knee arthroplasty revision for unexplained pain. The aim of this cross-sectional case-control study was to compare patient-reported outcome measures (PROMs) and satisfaction 1 to 3 years after revision of total knee arthroplasties (TKAs) for the indications of unexplained pain versus aseptic loosening.MethodsWe included 384 patients undergoing TKA revision for the indications of unexplained pain and aseptic loosening from January 1, 2018 to December 31, 2020 from the Danish Knee Arthroplasty Register. A total of 81 patients were revised for unexplained pain and 303 for aseptic loosening. Questionnaires including PROMs (Oxford Knee Score, EQ-5D-5L, and Forgotten Joint Score) and satisfaction with the surgery on a 0-100 scale (100 = not satisfied; 0 = very satisfied) were sent to digitally secured mailboxes. Time from revision to data collection was a median 3.1 years (range, 1.4-4.4 years).ResultsMedian Oxford Knee Score was 25 (interquartile range [IQR] 15) versus 31 (IQR 18) 1-3 years after revisions for unexplained pain versus aseptic loosening, P = .009. Median EQ-5D-5L was 0.6 (IQR 0.4) versus 0.8 (IQR 0.3) for unexplained pain versus aseptic loosening, P = .009. Median Forgotten Joint Score was 50 (IQR 7) versus 50 (IQR 16) for unexplained pain versus aseptic loosening, P = .905. Satisfaction was 75 (IQR 38) for unexplained pain and 50 (IQR 73) for aseptic loosening, P < .001.ConclusionPatients undergoing TKA revision for the indication of unexplained pain had worse results on PROMs than those revised for aseptic loosening. Likewise, patients revised for unexplained pain were less satisfied compared to patients revised for aseptic loosening. This information is valuable to both surgeons and patients when candidates for revision surgery are selected, to obtain the best possible outcomes.     

Impact of Polyethylene Thickness on Clinical Outcomes and Survivorship in Medial Mobile-Bearing Unicondylar Knee Arthroplasty

BackgroundThe thickness of the polyethylene bearing in medial unicondylar knee arthroplasty (UKA) is determined by the depth of the tibial resection, degree of correctable deformity, and balance of the knee. The purpose of this study is to evaluate whether polyethylene thickness in medial mobile-bearing UKA impacts clinical outcomes and survivorship.MethodsA retrospective review from 2004 to 2017 identified patients who underwent a primary mobile-bearing medial UKA with 2-year minimum follow-up or revision. A total of 2305 patients (3030 knees) met inclusion criteria. Patients were divided in 2 groups: thin bearing (group 1): 3-mm or 4-mm bearing and thick bearing (group 2): ≥ 5 mm. The thin group consisted of 2640 knees (87%), whereas the thick group had 390 knees (13%). Preoperative and postoperative demographics, range of motion, Knee Society scores, complications, and reoperations were evaluated.ResultsMean follow-up was 5.2 years (range, 0.5 to 12.6). There was no significant difference between groups in postoperative range of motion or Knee Society scores (P > .05). Manipulations were performed in 1.3% of patients and not significantly different between groups. The all-cause revision rate for group 1 was 4.02% and group 2 was 4.58% (P = .6). Revision rates for tibial aseptic loosening were significantly higher in group 2 (1.8%) than those in group 1 (0.7%) (P = .04). There was no significant difference in failure rates between groups for tibial collapse or fracture, femoral aseptic loosening, arthritic progression, bearing dislocation, or other cause of revision.ConclusionThis study demonstrated that thicker bearings in medial UKA increased the risk of tibial aseptic loosening, but not all-cause failures or clinical outcomes.     

Do Patients With Diabetes Have Poorer Improvements in Patient-Reported Outcomes After Total Knee Arthroplasty?

BackgroundDiabetes is one of the most common comorbidities in patients undergoing total knee arthroplasty (TKA) for osteoarthritis. However, the evidence remains unclear on how it affects patient-reported outcome measures after TKA.MethodsWe reviewed prospectively collected data of 2840 patients who underwent primary unilateral TKA between 2008 and 2018, of which 716 (25.2%) had diabetes. All patients had their HbA1c measured within 1 month before surgery, and only well-controlled diabetics (HbA1c <8.0%) were allowed to proceed with surgery. Patient demographics and comorbidities were recorded, and multiple regression was performed to evaluate the impact of diabetes on improvements in patient-reported outcome measures (Short Form 36 (SF-36), Western Ontario and McMaster University Osteoarthritis Index (WOMAC), Knee Society Score (KSS)) and knee range of motion (ROM).ResultsCompared with nondiabetics, patients with diabetes were more likely to possess a higher body mass index (P-value <.001), more comorbidities (P-value <.001), and poorer preoperative SF-36 Physical Component Summary (PCS) (P-value <.001), WOMAC (P-value = .002), KSS-function (P-value <.001), and knee ROM (P-value <.001). Multiple regression showed that diabetic patients experienced marginally poorer improvements in KSS-knee (?1.22 points, P-value = .025) and knee ROM (?1.67°, P-value = .013) than nondiabetics. However, there were no significant differences in improvements for SF-36 PCS (P-value = .163), Mental Component Summary (P-value = .954), WOMAC (P-value = .815), and KSS-function (P-value = .866).ConclusionPatients with well-controlled diabetes (HbA1c <8.0%) can expect similar improvements in general health and osteoarthritis outcomes (SF-36 PCS and Mental Component Summary, WOMAC, and KSS-function) compared with nondiabetics after TKA. Despite having marginally poorer improvements in knee-specific outcomes (KSS-knee and knee ROM), these differences are unlikely to be clinically significant.     

Modular Tibial Stem Use and Risk of Revision for Aseptic Loosening in Cemented Primary Total Knee Arthroplasty

BackgroundModular tibial stem extensions in total knee arthroplasty (TKA) are designed to reduce the risk of aseptic loosening of the tibial base plate. However, these implants add significant cost and an evaluation of their effectiveness in reducing this risk of loosening has not been studied in a large cohort. We sought to evaluate modular tibial stem utilization in primary TKA.MethodsWe conducted a cohort study using our integrated healthcare system’s Total Joint Replacement Registry. Patients who underwent cemented primary TKA were identified (2009-2019). Propensity scores were used to 1:1 match patients without to those with a stem extension. Cox proportional-hazards regression was used to evaluate the risk for revision due to aseptic loosening.ResultsTen thousand four hundred seventy six TKA with a modular tibial stem were matched to 10,476 TKA without a tibial stem. Stem utilization associated with a lower risk of revision for loosening across all postoperative follow-up (hazard ratio = 0.38, 95% confidence interval = 0.17-0.85).ConclusionIn a matched cohort study, we observed presence of a stem extension was associated with a lower risk of revision for aseptic loosening. Further study to identify specific risk factors for aseptic loosening and confirm the findings presented here are warranted.Level of EvidenceLevel III.     

The Effect of Tourniquet Use and Sterile Carbon Dioxide Gas Bone Preparation on Cement Penetration in Primary Total Knee Arthroplasty

BackgroundTourniquetless total knee arthroplasty (TKA) is experiencing resurgence in popularity due to potential pain control benefits. Furthermore, optimal cement technique and implant fixation remain paramount to long-term cemented TKA success, as aseptic loosening continues to be a leading cause of revision. The purpose of this study is to determine how tourniquet use and/or novel bone preparation using sterile, compressed carbon dioxide (CO₂) gas affected cement penetration in TKA.MethodsA retrospective review was performed on 303 consecutive primary TKAs with the same implant in 3 groups: (1) a tourniquet without sterile CO₂ compressed gas used for bone preparation, (2) no tourniquet with CO₂ gas, and (3) tourniquet use and CO₂ gas bone preparation. Cement penetration was measured on radiographs by two independent, blinded raters across 7 zones defined by the Knee Society Radiographic Evaluation System.ResultsThe 3 groups did not differ on age, body mass index, or gender (P ≥ .1). Cement penetration was greater in 6 of 7 zones with significantly greater cement penetration in 3 zones (tibial anteroposterior zone 2, femoral lateral zones 3A and 3P) in groups that utilized CO₂ gas bone preparation compared to the tourniquet only group (P ≤ .039).ConclusionBone prepared with CO₂ gas showed significantly more cement penetration in 3 zones with greater cancellous bone. The results suggest that use of CO₂ gas bone preparation may achieve greater cement penetration than using a tourniquet with lavage only.     

Pigmented villonodular synovitis after TKA associated with tibial component loosening

There is no known causal link between total knee arthroplasty (TKA) and pigmented villonodular synovitis (PVNS). There also is no known relationship between PVNS and implant loosening after TKA in the literature. This article presents a case of PVNS in a patient undergoing revision TKA for tibial component loosening. A 74-year-old woman who had undergone cemented bilateral TKA 5 years earlier presented with painful swelling in her right knee. At the time of the primary TKA, no abnormal signs were found in the synovial membrane. Routine follow-up radiographs did not indicate implant loosening. At the patient's final follow-up examination before revision surgery, a radiolucent lesion was found below the tibial component. During revision surgery, there was focal proliferation of the synovial tissue with heavy pigmentation around the anteromedial part of the tibial component. The abnormal tissue was removed, and the tibial component was exchanged. The articular surface of the polyethylene was not damaged, and backside wear was not found. For the revision surgery, 5-mm thick medial metal block and extension stem were used. Histological analysis of the resected tissue revealed the typical appearance of PVNS. We present a typical case of PVNS found during revision TKA 5 years after primary TKA. It is hoped this report will encourage surgeons to consider PVNS in the differential diagnosis of patients who present with painful swelling of the knee and to consider PVNS as one of the causes of implant loosening after TKA. Further research about causal factors between PVNS and implant loosening are needed.     

Clinical and Patient-Reported Outcomes of Medial Stabilized Versus Non–Medial Stabilized Prostheses in Total Knee Arthroplasty: A Systematic Review and Meta-Analysis

BackgroundThe aim of this systematic review and meta-analysis was to compare the clinical and patient-reported outcome measures (PROMs) of medial stabilized total knee arthroplasty (TKA) with non–medial stabilized TKAs.MethodsA systematic search of multiple databases was conducted in October 2019. A meta-analysis was conducted for the Knee Society Score (KSS), Knee Society Functional Score (KFS), range of motion (ROM), Oxford Knee Score (OKS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Forgotten Joint Score (FJS).ResultsA total of 857 articles yielded 21 studies eligible for inclusion with 13 studies used for quantitative analysis. The meta-analysis revealed that the medial stabilized group had a mean FJS that was 13.8 points higher than that of the non–medial stabilized TKA (mean difference [MD]: 13.83, P ≤ .0001, 95% confidence interval [CI]: 8.90-18.76, I² = 0%) which was less than the minimal clinically important difference of 14. The medial stabilized group also demonstrated a statistically significant difference in the postoperative ROM (MD = 2.52, P = .05, 95% CI: ?0.03 to 5.07, I² = 85%) and OKS when compared with the non–medial stabilized group (MD = 1.25, P = .02, 95% CI: 0.17-2.33, I² = 27%), but these were not clinically significant. There was no statistically or clinically significant difference in the KSS, KFS, and WOMAC scores.ConclusionMedial stabilized knee prostheses demonstrated no clinically significant differences for the ROM, OKS, WOMAC, KSS, and KFS. The FJS demonstrated the greatest MD and warrants further investigation. Future research is required using patient-reported outcome measures with a lower ceiling effect such as the FJS.     

Heterotopic Ossification Negatively Influences Range of Motion After Revision Total Knee Arthroplasty

BackgroundThe incidence of heterotopic ossification (HO) after total knee arthroplasty (TKA) varies and is of unclear clinical significance. This study aimed to identify the incidence of HO in patients undergoing revision TKA for either stiffness or aseptic loosening/instability and determine if the presence of HO is associated with inferior absolute range of motion (ROM) and ROM gains.MethodsEighty-seven patients were prospectively enrolled and separated into 2 cohorts to evaluate ROM after revision TKA (2017-2019). Group 1 (N = 40) patients were revised for stiffness, while group 2 (N = 47) patients were revised for either aseptic loosening or instability. Goniometer-measured ROM values were obtained preoperatively and at 6 weeks, 6 months, and 1 year postoperatively. Statistical analysis included a Fisher’s exact test to assess for an association between preoperative HO and final ROM at 1 year after revision TKA.ResultsHO was identified on preoperative radiographs in 17 patients (20%). There was a significantly higher rate of preoperative HO in patients revised for stiffness compared to patients revised for instability or loosening (30% vs 11%; P = .03). Five cases of HO qualitatively identified as most clinically severe were associated with lower ROM at each time point compared to the remainder of HO cases in this study cohort (P < .02).ConclusionThe presence of HO is greater in patients undergoing revision TKA for stiffness. Additionally, HO severity appears to have a major effect on preoperative and postoperative ROM trajectory. This information should help guide patient expectations and highlight the need for a comprehensive, standardized classification system for HO.     

Ten-Year Follow-Up of High-Flexion Versus Conventional Total Knee Arthroplasty: A Matched-Control Study

BackgroundHigh-flexion total knee arthroplasty (HF-TKA) prostheses were designed with hopes of improving knee function. Studies have suggested increased failure with HF-TKAs. The purpose is to compare clinical results of HF-TKA versus conventional TKA (C-TKA) from the same implant system with long-term follow-up.MethodsThis review of prostheses implanted between 2004 and 2007 matched 145 of 179 possible HF-TKAs with 145 of 1347 possible C-TKAs. Mean follow-up was 121.5 ± 20.3 months. We were unable to match 12 HF-TKAs. HF-TKAs with less than 8-year follow-up were excluded. The primary outcome was failure requiring revision. Secondary outcomes included range of motion (ROM), Knee Society Scores (KSS), and radiolucent lines.ResultsIn the matched cohort, there were 15 HF-TKA reoperations, 8 of which involved component revisions. There were 12 reoperations in the C-TKA cohort but no component revisions (P = .001). The analysis of the unmatched cohorts revealed a higher revision rate for HF-TKAs (P = .039) (HF-TKA: 10/179 vs C-TKA: 27/1347). At final follow-up, HF-TKAs exhibited more prosthesis radiolucent lines without evidence of loosening. Particularly, HF-TKAs demonstrated more femoral zone IV radiolucencies (38.7%) at final follow-up compared with C-TKAs (13.8%) (P < .001). There were no differences found between cohorts in ROM or KSS.ConclusionThis study found an increased incidence of failure requiring revision with the HF-TKA in the matched and unmatched analyses. Higher incidences of radiolucent lines were found with HF-TKA. With no observed differences in ROM or KSS and a higher rate of failure with HF-TKA, there appears to be no advantage for use of the HF-TKA.     

The benefit of revision knee arthroplasty for component malrotation after primary total knee replacement

Purpose

Revision surgery for component malrotation in the painful TKA is a relatively novel indication. The purpose of this study was to assess the benefit of revision TKA for component malrotation with regard to the clinical and functional outcomes.

Methods

Our retrospective case–control study included 51 patients who underwent revision surgery for malrotation with mean follow up of 42 months. They were equally matched to patients who had surgery for aseptic loosening.

Results

Knee society scores improved from 44/49 to 75/60 (p < 0.001) for the study group and 44/47 to 76/57 (p < 0.001) for the control group. There was no statistical difference between the groups, including for VAS scores, narcotic reduction or patient satisfaction. Our study showed that revision surgery for malrotation is as beneficial as surgery for aseptic loosening with regard to clinical and functional outcome.

Conclusions

We recommend CT in painful TKA to assess component malrotation for which revision TKA is beneficial.     

Clinical outcomes of open reduction and internal fixation for intra-articular complex tibial plateau non-union with 3-year minimum follow-up

BackgroundA tibial plateau fracture is one of the most challenging fractures for both knee and trauma surgeons because of the high incidence of post-traumatic knee osteoarthritis. To our knowledge, there has been no study concerning the clinical outcomes after surgery in patients with non-union of complex intra-articular tibial plateau fractures. Thus, the present study aimed to assess and report the clinical outcomes in them.MethodsThe study included four patients with non-union of complex tibial plateau fractures who underwent failed initial fixation treatment or could not undergo initial fixation owing to concomitant injury and who were followed up with a diagnosis of non-union for a minimum of 6 months. At the latest follow-up, patient-reported outcome measures, including the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Oxford 12-item Knee Score (OKS), were assessed. Additionally, the knee range of motion (ROM) was evaluated.ResultsThe mean duration from the initial surgery to revision surgery was 8.8 months, and the mean duration from the revision surgery to fracture union was 4.8 months. At the latest follow-up, the mean WOMAC score was 9.8 and the mean OKS was 43.5. Additionally, the mean knee ROM values were ?11 degrees of extension and 100 degrees of flexion. All four patients had become able to walk without any aid after averaged 4.5-years follow up.ConclusionFavorable clinical outcomes can be achieved following revision surgery involving open reduction and IF in patients with non-union of complex tibial plateau fractures after failed initial treatment.Level of evidenceLevel IV, Case report.     

Effect of Different Tourniquet Pressure on Postoperative Pain and Complications After Total Knee Arthroplasty: A Prospective,Randomized Controlled Trial

BackgroundTourniquet pressure inflation is commonly selected between 100 and 150 mm Hg above the systolic blood pressure (SBP). Given the lack of evidence to support a given inflation pressure, our study aimed to ascertain the lowest tourniquet pressure that facilitated total knee arthroplasty (TKA) and resulted in the least postoperative pain and complications.MethodsIn a double-blind, randomized controlled trial of patients scheduled for unilateral primary TKA, 150 were assigned to use tourniquet pressures of SBP + 75 mm Hg (group I), SBP + 100 mm Hg (group II), and SBP + 150 mm Hg (group III). The quality of the bloodless field, total blood loss, and limb swelling were determined perioperatively. Clinical outcomes were evaluated by visual analog scale for pain at thigh and surgical site, serum creatinine phosphokinase levels, wound complications, range of motion, and Knee Society Score.ResultsVisual analog scale for pain at thigh and surgical site were lowest in group I (P < .01) and highest in group III (P < .01). However, the quality of bloodless field at the tibial cutting surface was significantly better in group III compared to group I/II but not at the femoral cutting surface. The total blood loss and limb swelling showed no difference among 3 groups. Postoperative serum creatinine phosphokinase levels at 24 and 48 hours and wound complications in group III were significantly higher than group I (P < .01) and group II (P < .01). Nevertheless, postoperative knee range of motion and Knee Society Score were not significantly different among 3 groups.ConclusionPost TKA, the lowest tourniquet pressure was associated with significantly less postoperative tourniquet and surgical site pain, muscle damage, and wound complications.