Surgical Approaches in Total Knee Arthroplasty: A Meta-Analysis Comparing the Midvastus and Subvastus to the Medial Peripatellar Approach

Subvastus, midvastus and medial parapatellar approaches are the most popular approaches in total knee arthroplasty (TKA). However, the superior approach in TKA still remains controversial. We therefore conducted a meta-analysis to quantitatively compare the midvastus and subvastus approaches to the medial parapatellar approach in TKA. A total of 32 randomized controlled trials (RCTs) with 2451 TKAs in 2129 patients were included in this study. The meta-analysis suggested that, when compared with the medial parapatellar approach, the midvastus approach showed better outcomes in pain and knee range of motion at postoperative 1–2 weeks but also was associated with longer operative time; the subvastus approach showed better outcomes in knee range of motion at postoperative 1 week, straight leg raise and lateral retinacular release.     

Comparisons of the Efficacy and Safety of Total Knee Arthroplasty by Different Surgical Approaches: A Systematic Review and Network Meta‐analysis

The purpose of this network meta‐analysis was to investigate the efficacy and safety of total knee arthroplasty (TKA) considering seven different surgical approaches. Four databases (PubMed, Cochrane Library, EMBASE, Web of Science) were searched for clinical randomized controlled trials (RCTs) involving TKA with different surgical approaches. STATA 14.0 was used to construct network maps and publication bias graphs and conduct inconsistency tests, network meta‐analyses, and surface under the cumulative ranking (SUCRA) calculations. A total of 51 RCTs involving 4061 patients and 4179 knees from 18 countries were included. Among the seven surgical approaches, the midvastus approach (MV) was the top choice to reduce tourniquet use time, the subvastus approach (SV) had the shortest operation time, the mini‐midvastus approach (Mini‐SV) was associated with the least amount of time to achieve straight leg raise (SLR) after surgery, the mini‐medial parapatellar approach (Mini‐MP) reduced postoperative pain effects, and the medial parapatellar approach (MP) was the best approach to improve range of motion (ROM). Excluding the quadriceps‐sparing approach (QS), which was not compared, the use of the mini‐midvastus (Mini‐MV) may shorten the hospital stay. There were no significant differences in blood loss, postoperative complications, American Knee Society Score (AKSS) objective, or AKSS functional between the seven surgical approaches (P > 0.05).     

Is Minimally Invasive Surgery in Total Knee Arthroplasty Really Minimally Invasive Surgery?

Minimization of soft-tissue damage is one of the primary purposes behind the application of minimally invasive surgery (MIS) in total knee arthroplasty (TKA). A consecutive series of 147 TKAs were enrolled in the present study, with 96 MIS-TKAs using 11 quadriceps-sparing, 46 subvastus, 32 midvastus, and 7 parapatellar approaches and 51 conventional TKAs using 22 subvastus, 9 midvastus, and 20 parapatellar approaches. Serum levels of creatinine phosphokinase, myoglobin, aldolase, lactate dehydrogenase, glutamic oxaloacetic transaminase, and creatinine were measured on postoperative days 0, 1, 2, 4, 7, and 14. Postoperative rising index (RI) was expressed as a proportion of the preoperative value. When RIs were compared between MIS-TKA and conventional TKA, no significant differences were found for any enzymes. Interestingly, the midvastus approach displayed the highest RIs for creatinine phosphokinase and myoglobin between the 4 vastus-splitting approaches. Consequently, degree of muscle damage was equivalent between MIS-TKA and conventional TKA, whereas types of vastus-splitting approach appeared closely related to muscle damage.     

Strength and voluntary activation of quadriceps femoris muscle in total knee arthroplasty with midvastus and subvastus approaches

To determine and compare the influence of 2 different approaches on quadriceps femoris muscle function in total knee arthroplasty (TKA), 20 patients (14 women, 6 men) with bilateral knee osteoarthritis underwent a 1-stage bilateral TKA. Surgical approaches (subvastus, midvastus) were performed by a random selection. Measurements of quadriceps voluntary activation and maximal voluntary contraction were estimated by a twitch interpolation technique before, 3 and 6 months after TKA. Knee pain was quantified by the Lewis Score. There was no difference between the 2 approaches at 3 and 6 months after TKA with regard to maximal voluntary contraction (P = 0.84, F = 0.041) and voluntary activation (P = .863, F = 0.031). In the subvastus group was a significantly higher knee pain until 6 months after surgery (P = .02). The subvastus approach for TKA does not provide any advantages compared with the midvastus approach with respect to the quadriceps femoris muscle strength in the early postoperative period. Furthermore, the subvastus approach caused significantly more pain postoperatively.     

Comparison of Cruciate-Sacrificing vs Posterior-Stabilized Total Knee Replacement Using a Contemporary Total Knee System

BackgroundThe use of highly conforming polyethylene tibial inserts in cruciate-retaining total knee arthroplasty (TKA) often requires posterior cruciate ligament (PCL) release/sacrifice for balancing (CS TKA). The CS TKA relies on the posterior capsule, collateral ligaments, and articular conformity without a cam or post to achieve stability. Using prospectively collected data we compared clinical outcomes of CS TKA to posterior-stabilized (PS) TKA utilizing a contemporary TKA system.MethodsSixty-nine consecutive CS TKAs were compared to 45 consecutive PS TKAs at 2-year minimum follow-up. CS knees were balanced with the PCL released. Preoperative/postoperative range of motion (ROM), Knee Society Scores (KSS), stair function, and squatting ROM were analyzed.ResultsAt minimum 2-year follow up, CS and PS TKA demonstrated significant improvement in ROM (P < .001), KSS (Pain, P < .001; Function, P < .001), and KSS stair function (P < .001), with no revisions. There was no difference in preoperative to postoperative improvements for passive knee ROM (10° (0°-20°) vs 13° (5°-25°); P = .16), KSS Pain (34 (21-42) vs 38 (24-46); P = .22), KSS Function (35 (30-50) vs 35 (18-50); P = .34), and KSS stair function (10 (10-20) vs 10 (0-20); P = .37) for CS and PS TKA, respectively. CS TKA had higher squatting ROM (P = .02) at minimum 2-year follow-up compared to PS TKA.ConclusionBoth PS and CS TKA provided significant improvement in clinical outcomes, with no differences in passive ROM, KSS, or stair function postoperatively. Our data support that with proper articular conformity and balancing, cruciate-retaining TKA in a PCL-deficient knee (CS TKA) is appropriate. This may be design specific and further prospective randomized studies are needed to corroborate these findings.     

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.     

Range of motion and function are similar in patients undergoing TKA with posterior stabilised and high-flexion inserts

It is debatable whether high-flexion (HF) total knee arthroplasty (TKA) designs will improve postoperative flexion and function or will diminish the need for manipulation under anaesthesia (MUA). We retrospectively analysed range of motion (ROM), flexion, Knee Society Score (KSS), and rate of MUA in a consecutive group of patients who underwent TKA with a conventional posterior stabilised (PS) insert or an HF insert using identical surgical technique, implant design, and postoperative care. Fifty TKAs with a standard PS insert were matched for patient’s age, gender, preoperative ROM, and KSS with 50 TKA performed with an HF insert. The patient’s ROM and KSS were evaluated at six weeks, four months, and one year postoperatively. The outcome variables (flexion, ROM, KSS, and manipulation rate) in both groups were compared using the generalised estimating equations method. A second analysis of patients with preoperative flexion ≥120° was performed. The ROM, flexion, and patient-reported KSS was similar in both groups at each time period. The rate of MUA was also similar. Patients with a preoperative ROM of at least 120° showed similar results. Our study found that one year after surgery, patients who underwent TKA with a PS or an HF insert achieved similar flexion, ROM, and function.     

小切口辅助手法松解治疗TKA术后关节僵硬

目的探讨髌外侧小切口辅助麻醉下手法松解治疗初次全膝关节置换术后早期膝关节僵硬的临床疗效。方法对10例初次全膝关节置换术后早期（6周内）发生膝关节僵硬的患者行髌外侧小切口辅助麻醉下手法松解。其中男性3例,女性7例;术前膝关节平均活动度为（74.4±9.44）°（60°～85°）,平均年龄（72.8±7.18）岁（59～81岁）。排除因感染、假体松动、假体位置不良等明确原因导致术后关节僵硬的患者。术中给予蛛网膜下腔麻醉,反复、柔和、持续地对膝关节进行手法松解,结合髌外侧小切口,使其达到最大的活动度。采用KSS评分对膝关节术前及术后功能进行评价。结果平均随访（2.6±1.04）年（1～4年）,术中能达到的平均活动度为（112.5±9.20）°（100°～125°）,末次随访时平均活动度为（105±6.97）°（95°～115°）。KSS评分从术前平均69分提高到末次随访时平均82分。术前术后KSS评分差异有统计学意义（t=14.40,P〈0.01）。结论髌外侧小切口辅助麻醉下手法松解是治疗初次全膝关节置换术后早期发生膝关节僵硬安全、有效的治疗手段,通过早期治疗,能显著改善膝关节功能。     

Two cases of late medial instability of the knee due to hip disease after total knee arthroplasty

IntroductionThere are few specific reports of late medial instability after total knee arthroplasty (TKA). We described two cases of late medial instability of the knee due to hip disease with osteoarthritis or rheumatoid arthritis after TKA, which required revision TKA.Presentation of casesAn 82-year-old woman experienced right femoral neck fracture due to a fall that required conservative treatment at age 77 years and underwent left TKA at age 80 years. A 68-year-old woman underwent left TKA at age 54 years, right TKA at age 64 years, and left THA at age 67 years. Both cases required revision TKA with constrained knee prostheses due to the severe medial instability. Hip-knee-ankle (HKA) angle, range of motion (ROM), Knee Society score (KSS) and functional score (FS) were evaluated pre- and postoperatively. Their respective HKA angle improved from 134° and 155° preoperatively to 184° and 179° postoperatively. KSS improved from −4 and 53 points to 59 and 100 points, respectively. FS improved from −10 and 58 points to 25 and 90 points, respectively. In the 82-year-old woman, ROM did not improve from −10–90° to −20–90°. On the other hand, in the 68-year-old woman, ROM improved from 0–110° to 0–125°. The late medial instability in the current case report was partly due to a similar mechanism underlying the long leg arthropathy and coxitis knee caused by hip joint degeneration.ConclusionsConstrained prostheses were applied for both patients, providing moderately good short-term results.     

Perioperative Systemic Dexamethasone Reduces Length of Stay in Total Joint Arthroplasty: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BackgroundThe objective of this review is to examine the effect of perioperative systemic corticosteroids at varying doses and timings on early postoperative recovery outcomes following unilateral total knee and total hip arthroplasty. The primary outcome was length of stay (LOS).MethodsA systematic review and meta-analysis of randomized controlled trials was performed. MEDLINE, EMBASE, and Cochrane Library databases were searched from inception to June 1, 2020. Studies comparing the outcome of adult patients receiving a systemic steroid to patients who did not receive steroids were included.ResultsSeventeen studies were included, incorporating 1957 patients. Perioperative corticosteroids reduced hospital LOS (mean difference [MD] = ?0.39 days, 95% confidence interval [CI] ?0.61 to ?0.18). A subsequent dose of corticosteroid at 24 hours further reduced LOS (MD = ?0.33, 95% CI ?0.55 to ?0.11). Corticosteroids resulted in reduced levels of pain on postoperative day (POD) 0 (MD = ?1.99, 95% CI ?3.30 to ?0.69), POD1 (MD = ?1.47, 95% CI ?2.15 to ?0.79), and POD2. Higher doses were more effective in reducing pain with activity on POD0 (P = .006) and 1 (P = .023). Steroids reduced the incidence of PONV on POD1 (log odds ratio [OR] = ?1.05, 95% CI ?1.26 to ?0.84) and POD2, with greater effect at higher doses (P = .046). Corticosteroids did not increase the incidence of infection (P = 1.000), venous thromboembolism (P = 1.000), or gastrointestinal hemorrhage (P = 1.000) but were associated with an increase in blood glucose (MD = 5.30 mg/dL, 95% CI 2.69-7.90).ConclusionPerioperative corticosteroids are safe, facilitate earlier discharge, and improve patient recovery following unilateral total knee arthroplasty and total hip arthroplasty. Higher doses (15-20 mg of dexamethasone) are associated with further reductions in dynamic pain and PONV, and repeat dosing may further reduce LOS.     

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.     

Psychometrical properties of the Turkish translation of the New Knee Society Scoring System

ObjectiveTo translate the New Knee Society Scoring System (KSS) into Turkish and to evaluate the psychometric properties of the translated questionnaire.MethodsThis study was conducted on 66 knees of 43 pre-op patients who were scheduled for total knee arthroplasty (TKA) and 50 knees of 26 knee arthroplasty patients at least 6 months postoperatively. KSS was translated and culturally adapted according to the guidelines of Guillemin and Beaton. Demographic and clinical characteristics of the patients were recorded. Patients completed WOMAC, KOOS and SF-36 surveys along with the Turkish version of the new KSS. After the initial evaluation, patients were asked to refill the new KSS 1 week later. Internal consistency and reliability were tested using Cronbach's alpha coefficient and intraclass correlation coefficient (ICC). Validity was assessed by calculating the Spearman's correlation coefficient between the new KSS and WOMAC, KOOS and SF-36 scores.ResultsThe mean ages of the pre and post-operative groups were 67.16 ± 7.85 years and 71.65 ± 6.95 years respectively. The Cronbach's alpha coefficients of the new KSS calculated for symptoms (0.814), patient satisfaction (0.947), patient expectations (pre-op = 1.000, post-op = 0.997) and functional activities (0.864) were high. The ICC scores ranged between 0.790 and 0.951. The pain subscore of the new KSS and the pain subscores of the WOMAC (r = −0.720; p < 0.01), KOOS (r = 0.550; p < 0.01) and SF-36 (r = −0.434; p < 0.01) were highly correlated. Emotional role functioning (RH), mental health (MH) and social role functioning (SF) subscores of SF-36 showed no correlation with the all subscores of the new KSS (p > 0.05). No floor or ceiling effects in the new KSS scores were detected.ConclusionIt is concluded that the new KSS is a valid and reliable questionnaire which can be used in evaluating the pre and post-operative Turkish speaking TKA patients.Level of evidenceLevel III Diagnostic Study.     

经股内侧肌下方入路行全膝关节置换术的早期疗效

目的探讨经股内侧肌下方入路行全膝关节置换术(TKA)的早期疗效。方法通过回顾性研究方法,比较分析经股内侧肌下方入路和经典内侧髌旁入路行TKA治疗60例64膝原发性骨关节炎患者。其中经股内侧肌下方入路32例33膝,经典内侧髌旁入路28例31膝,随访时间超过3个月。比较两组患者的手术时间、切口长度、术后伤口引流量,术后2周、6周及3个月时关节活动度、疼痛程度以及膝关节功能。结果两组患者在手术时间、切口长度间的差异无统计学意义。术后经股内侧肌下方入路组伤口引流量200.2 m l,较经典内侧髌旁入路组340.6 m l明显减少。两组患者术后直腿抬高时间分别是2.8 d和5.2 d(t=-10.0208,P=0.0000),术后2周时两组患者关节活动度分别为97.2°和83.8°(t=2.5657,P=0.0128),疼痛程度经视觉模拟评分(VAS评分)分别为3.2分和4.6分(t=-0.6545,P=0.0000),组间差异有统计学意义。而术后6周、3个月时两组患者关节活动度(6周:t=0.2274,P=0.8209;3个月:t=0.6411,P=0.5239)、疼痛程度(6周:t=-0.6146,P=0.5423;3个月:t=-1.1358,P=0.2606)和关节功能(6周:t=0.3937,P=0.6955;3个月:t=1.0541,P=0.2960)差异没有统计学意义。结论与经典内侧髌旁入路相比,经股内侧肌下方入路行TKA具有术后出血少,术后早期膝关节功能恢复快等优点,其远期疗效和经典入路没有明显差异。     

Quadriceps-sparing, minimal-incision total knee arthroplasty: a comparative study

Our study was conducted to compare radiographic alignments and functional outcomes with 2 approaches to minimal-incision total knee arthroplasty (TKA): the minimal-incision medial parapatellar (MP) approach and the quadriceps-sparing (QS) approach with side-cutting instruments. Sixty patients (80 knees) with primary osteoarthritis were randomly assigned to receive MP or QS TKA. Postoperative alignment of the femoral component was significantly less valgus, and postoperative alignment of the tibial component was significantly more varus with the QS approach than with the MP approach. One tibial outlier and 3 femoral outliers were observed with QS TKA. The overall postoperative hip-knee-ankle axis was more varus, and surgical time was longer with QS TKA. Short-term isokinetic peak muscle torque, postoperative pain, and functional outcomes did not differ between the approaches.     

Minimally invasive total knee arthroplasty using a cruciate-retaining knee system: A 3–5 year study with comparison to a standard approach

Background/PurposeMinimally invasive surgery (MIS) for total knee arthroplasty (TKA) is a recent development. Most published studies of the procedure report on early experience, and have emphasized early recovery and good outcomes in the first 3 months to 1 year.MethodsThis retrospective study compared 121 TKA done through a minimally invasive midvastus approach with 50 TKA done using a standard medial parapatellar approach, and assessed the results at a minimum follow-up of 3–5 years. A cemented U2 cruciate-retaining knee (United, Taipei, Taiwan) was used in both patient groups.ResultsThe postoperative mean knee score and function score were 95.3 (range, 69–110) and 82.3 (range, 20–100) respectively in the MIS TKA group, compared to 94 (range, 78–00) and 82 (range, 30–100) for the control group (standard approach). The postoperative Knee Society scores did not differ significantly between the two groups. The postoperative mean range of motion was 113.8° (range, 70–145°) in the MIS TKA group compared with 105.1° (range, 40–130°) for the control group, and the difference was significant (p < 0.05). There was no difference in postoperative coronal X-ray alignment between the two groups, neither were there any outliers in the component alignment and component size in the MIS TKA group. There were three knees (2%) with anterior femoral notching in the MIS TKA group compared to no knee notching for the control group.ConclusionThough the MIS TKA was technically demanding, the outcomes at 3–5 years’ follow-up were at least as good as those obtained with the standard medial parapatellar TKA procedure.     

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.     

A Prospective Randomized Controlled Trial Comparing Medial-Pivot versus Posterior-Stabilized Total Knee Arthroplasty

BackgroundThe medial-pivot (MP) design for total knee arthroplasty (TKA) aims to restore more natural “ball-and-socket” knee kinematics compared to the traditional posterior-stabilized (PS) implants for TKA. The objective of this study is to determine if there was any difference in functional outcomes between patients undergoing MP-TKA vs PS-TKA.MethodsThis prospective randomized controlled trial consisted of 43 patients undergoing MP-TKA vs 45 patients receiving a single-radius PS-TKA design. The primary outcome was postoperative range of motion (ROM). Secondary outcomes included the Western Ontario and McMaster Universities Arthritis Index, Oxford Knee Score, Knee Society Score (KSS), and radiological outcomes. All study patients were followed-up for 2 years after surgery.ResultsPatients undergoing MP-TKA had comparable ROM at 1 year (114.6° ± 16.3° vs 111.3° ± 17.8° respectively, P = .88) and 2 years after surgery (114.9° ± 15.5° vs 114.9° ± 16.4° respectively, P = .92) compared to PS-TKA. There were also no differences in Western Ontario and McMaster Universities Arthritis Index (26.8 ± 19.84 vs 22.0 ± 12.03 respectively, P = .14), Oxford Knee Score (42.7 ± 8.1 vs 42.3 ± 6.7 respectively, P = .18), KSS clinical scores (82.9 ± 16.96 vs 81.42 ± 10.45 respectively, P = .12) and KSS functional scores (76.2 ± 18.81 vs 73.93 ± 8.53 respectively, P = .62) at 2-year follow-up. There was no difference in postoperative limb alignment or complications.ConclusionThis study demonstrated excellent results in both the single-radius PS-TKA design and MP-TKA design. No differences were identified at 2-year follow-up with respect to postoperative ROM and patient-reported outcome measures.     

Outcome of subvastus approach in elderly nonobese patients undergoing bilateral simultaneous total knee arthroplasty: A randomized controlled study

Background:

Subvastus approach in total knee arthroplasty (TKA) spares the quadriceps and may assist in faster rehabilitation. The present randomised controlled study was conducted to determine if the subvastus approach results in early recovery, faster mobilization, shorter hospital stay, and improved function.

Materials and Methods:

100 patients undergoing simultaneous bilateral TKA were randomized into two groups: subvastus group and medial parapatellar group. The patients were assessed clinically using VAS, time to straight leg raise, ability to stand with walker, ability to use a commode chair, ability to climb stairs, flexion at discharge, and day of discharge. Perioperative blood loss and duration of surgery were also compared. The patient were kept on same pain management and physiotherapy protocol. The evaluation was done at day 0,1,3 and at discharge. Statistical analyses tested the null hypotheses of no differences in patients treated with either group at 95% significance level (P < 0.05).

Results:

The VAS score was significantly lower in subvastus group on day 1 and day 3. Also mean hospital stay was 2.04 days less in subvastus group. Patients with subvastus approach were able to perform straight leg raising 0.44 days earlier. Though time to stand with walker was same for both groups, the ability to use commode chair, and climb stairs was significantly early (P < 0.05) in the subvastus group. The average flexion at the time of discharge in subvastus and parapatellar group were 100.8 and 96.8°, respectively. The mean perioperative blood loss in subvastus group and parapatellar group were 343 ml and 372 ml, respectively. Average surgical time required for subvastus approach and parapatellar approach were 108.5 and 94.3 min, respectively.

Conclusions:

Subvastus approach produce appreciably less pain and faster mobilization due to lesser insult to quadriceps, thus assisting in early rehabilitation, shorter hospital stay, less expenditure, and more patient satisfaction.     

Postoperative Pain and Contracture Following Total Knee Arthroplasty Comparing Parapatellar and Subvastus Approaches

The purpose of this study was to see if subvastus approach would decrease incidence of postoperative contracture and pain following TKA compared to standard parapatellar approach. Retrospective review of 546 patients in Group A undergoing TKA using parapatellar approach were compared to 255 patients in Group B undergoing subvastus approach. No statistically significant differences regarding OR time, blood loss, BMI, or LOS. Total of 23 (4%) manipulations under anesthesia for contracture in Group A compared to 6 (2%) in Group B (p > 0.05). Postoperative pain scores at 6 weeks was greater in Group A, p < 0.05. We feel that a subvastus approach minimizes trauma to the extensor mechanism, and therefore decreases the incidence of postoperative pain following TKA.     

Two Year Follow-up of the Preservation Unicompartmental Knee Implant

Reported results of unicondylar knee arthroplasty (UKA) have mixed reviews in comparison with results of tri-compartmental knee arthroplasty (TKA). We prospectively evaluated the short-term results (2 years) of a newer design of a UKA implant (Preservation UKA) with a cobalt–chromium femoral component and an all polyethylene tibial component. Seventy-two patients with intact ligaments and loss of only medial articular cartilage received the Preservation prosthesis. Data were obtained using WOMAC, Knee Society score (KSS), and standard radiographs. WOMAC scores improved by 24 points and KSS improved by 33 points at 2-year follow-up. Mean flexion increased by 4° to126° at 2 years. On X-ray, only one patient had a radiolucency. No fractures occurred. Two knees were revised due to clinical symptoms of medial compartment pain. This 2-year follow-up study of the Preservation UKA shows promising early results. Long-term data would be necessary to compare results with TKA or other unicompartmental replacements.