A prospective randomised study of minimally invasive midvastus total knee arthroplasty compared with standard total knee arthroplasty

Mid-vastus approach induces milder short-term effects on postural control compared to parapatellar approach in total knee arthroplasty

BACKGROUND

Mid-Vastus and Medial Parapatellar techniques are used for total knee arthroplasty. Their short-term effects within the first month after surgery are yet unexplored. The purpose of this study was to compare Mid-Vastus and Medial Parapatellar effects on knee strength and balance control, at 5 days, 2 weeks and one month after surgery. It was hypothesized that Mid-Vastus would induce milder effects on the dependent variables due to its less invasive nature.

METHODS

Twenty females, randomly assigned to either the Mid-Vastus or the Medial Parapatellar group performed knee flexion-extension force and 30 s of bipedal stance before, 5 days, 2 weeks and one month after surgery. Maximum force, weight distribution and travel distance of the Center of Pressure were calculated.

FINDINGS

Both groups showed decreased force output at all post-measurements compared to before surgery. Medial Parapatellar group showcased significantly higher travel distance at the 2 weeks measurement (Z = -2.268, p = .023, |r| = 0.507) compared to before surgery. This result was also imprinted on the travel distance of the non-surgical knee limb in the post (t = 3.259, p = .004, d = 1.456), 2 weeks (Z = -2.570, p = .009, |r| = 0.574) and one month measurement (t = 2.653, p = .016, d = 1.185).

INTERPRETATION

While force is affected for both approaches, Mid-Vastus approach does not affect postural control. Therefore, Mid-Vastus is a less invasive technique compared to Medial Parapatellar. This work highlights the differences between Mid-Vastus and Medial Parapatellar approaches at least until the first month of rehabilitation.

Subvastus Approach Supporting Fast-Track Total Knee Arthroplasty Over the Medial Parapatellar Approach: A Systematic Review and Network Meta-Analysis

BACKGROUND

Numerous surgical approaches are being used to perform total knee arthroplasty (TKA). This systematic review and network meta-analysis aimed to compare surgical approaches used in TKA regarding postoperative outcomesat different time points.

METHODS

We performed a literature search from medical database inception until October 2, 2021. We searched for randomized controlled trials (RCTs) investigating patients undergoing TKA and comparing at least 2 surgical approaches regarding early postsurgical clinical outcomes (range of motion [ROM], pain on a visual analog scale, and Knee Society Score [KSS]). We included 33 RCTs in our networks. Using paired and network meta-analysis, we calculated pooled mean differences (MDs) with 95% CIs by comparing surgical approaches to the medial parapatellar method.

RESULTS

The subvastus (SV) method performed the best on days 1 (MD = 6.99; CI: 1.08; 12.89), 3 (MD = 8.00; CI: 2.08; 13.92), 4 (MD = 27.01; CI: 18.09; 35.92), and 6 (MD = 27.22; CI: 18.38; 36.07) for ROM improvement. Regarding the decrease in pain, the mini SV approach offered significantly lower pain values on days 1 (MD = -1.98; CI: -2.93; -1.03), 3 (MD = -0.85; CI: -1.49; -0.22), and 7 (MD = -1.90; CI: -2.23; -1.57). The differences decreased as time passed. Furthermore, the SV and mini-SV methods performed the best regarding total, knee and function KSS.

CONCLUSION

Quadriceps-sparing approaches, especially the SV and mini-SV, are superior to the other approaches in the early postsurgical period, but the differences decrease as time passes.

Minimally invasive medial femoral approach to total knee arthroplasty improves short-term outcomes compared to the standard medial parapatellar approach: a systematic review and meta-analysis

OBJECTIVE

The aim of this study is to conduct a comprehensive evaluation of the effectiveness of the medial parapatellar approach via the vastus medialis obliquus muscle in comparison with the standard medial parapatellar approach for total knee arthroplasty, using a systematic approach.

METHODS

A computer search was conducted on PubMed, EMBASE, Medline, Cochrane libraries, and Web of Science databases to comprehensively collect randomized controlled studies on minimally invasive (MMV) approaches for knee arthroplasty, specifically the vastus and medial parapatellar (MP) approaches. Two authors independently screened the literature based on inclusion and exclusion criteria, evaluated the quality of the included studies using the Cochrane systematic review method, and performed a meta-analysis using RevMan 5.3 software.

RESULTS

A total of twelve randomized controlled studies were ultimately included, comprising 788 knees. The small incision medial femoral muscle approach (MMV) group consisted of 398 cases, while the traditional parapatellar approach (MP) group consisted of 390 cases. Data analysis showed that in the comparison of KSS, VAS, and ROM score at 3 months after surgery, MMV approach was superior to MP approach [MD = 2.89, 95%CI (0.33, 5.46), P = 0.03], [MD = - 0.22, 95%CI (- 0.36, - 0.09), P = 0.001], and [MD = 1.08, 95%CI (0.04, 2.12), P = 0.04]. However, there was no significant difference in the postoperative KSS, VAS, and ROM score between the MMV and MP approaches at 6 and 12 months after surgery. The operation time of the MMV group was longer than that of the MP group [MD = 8.98, 95%CI (4.64, 13.32), P < 0.0001], and the number of days of straight leg raising after surgery was shorter in the MMV group than in the MP group [MD = - 1.91, 95%CI (- 3.45, - 0.37), P = 0.01], with statistically significant differences. There was no significant difference in the lateral support band release rate [OR = 0.72, 95%CI (0.23, 2.28), P = 0.58], length of hospital stay [MD = 0.07, 95%CI (- 0.18, 0.31), P = 0.58], postoperative complications [MD = 0.62, 95%CI (0.33, 1.18), P = 0.15], and intraoperative blood loss [MD = 70.50, 95%CI (- 57.51, 198.72), P = 0.28].

CONCLUSION

Most of the approaches have similar length of stay and incidence of complications compared to standard approaches. However, the minimally invasive midvastus approach has shown potential to improve short-term outcomes.

STUDY REGISTRATION

PROSPERO registration number CRD42023410583.

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).

Comparison of minimally invasive approaches and standard median parapatellar approach for total knee arthroplasty: A systematic review and network meta-analysis of randomized controlled trials

BACKGROUND: Minimally invasive total knee arthroplasty (TKA) has been actively advertised by the orthopedic industry. The purpose of this network meta-analysis was to comprehensively compare the effectiveness of four minimally invasive surgery (MIS) approaches and the medial parapatellar (MPP) approach to improve the American Knee Society Score (KSS) in primary TKA. MATERIALS AND METHODS: Studies were comprehensively searched on PubMed, Embase, Cochrane Library (CENTRAL), Web of Science and Science Direct up to June 2018 with a major focus on the outcome of KSS. Risk of bias was assessed using the Cochrane risk of bias tool. Quality assessment was performed using the GRADE system. Both pair-wise and network meta-analyses are calculated to comprehensively compare the effectiveness of four MIS and TKA approaches. RESULTS: Eleven trials with 1025 knees undergoing TKA were included. Our analysis showed that both MPP and MIS approaches provided improvement in terms of short-term (four-eight weeks) total, objective and functional KSS. The network-meta analysis revealed that MIS approaches showed a trend towards superior KSS improvement over standard MPP approaches. However, statistical advantages were only observed in the mini-MPP group for functional KSS compared to the conventional MPP and quadriceps-sparing (QS) groups. CONCLUSIONS: Evidence shows that MIS TKA approaches are effective alternatives to MPP approaches. However, orthopedic surgeons should be cautiously optimistic about minimally invasive TKA in terms of KSS improvement.

Minimally invasive surgery total knee arthroplasty is less popular, but the prosthesis designed specifically for MIS provides good survival and PROMs with a minimum follow-up of 10 years

BACKGROUND

The concept of minimally invasive surgery (MIS) was introduced in total knee arthroplasty (TKA) in the late 1990s. The number of MIS TKAs has clearly decreased in recent years. An implant designed specifically for MIS TKA has been used all over the world, but there are no reports of long-term postoperative results. The purpose of this study was to characterize long-term clinical results with a minimum follow-up of 10 years.

METHODS

This retrospective study included 109 consecutive patients with 143 NexGen CR-Flex prostheses, which are MIS tibial component prostheses designed specifically for MIS TKA. Twelve-year survival analysis was performed using Kaplan-Meier method. Revision surgery for any reason was the endpoint. Long-term clinical and radiographic results of 74 knees (55%) in 60 patients with more than 10 years of follow-up were analyzed.

RESULTS

The cumulative survival rate of the single-radius posterior-stabilized TKA of 74 knees was 94.7% (95% confidence interval, 90-99%) at 12 years after surgery. Seven knees (9%) required additional surgery during the 10-year follow-up because of periprosthetic infections. Mean postoperative Knee Society knee score and functional score were 91 and 74 points, respectively. There were no cases of prosthesis breakage, polyethylene wear, or aseptic loosening of the prosthesis.

CONCLUSION

The prosthesis designed specifically for MIS TKA is associated with good survival and clinical results with a minimum follow-up of 10 years, even though MIS TKA has become less popular.

LEVEL OF EVIDENCE

III.

Better outcomes after minimally invasive surgeries compared to the standard invasive medial parapatellar approach for total knee arthroplasty: a meta-analysis

PURPOSE

Minimally invasive surgery (MIS) for total knee arthroplasty (TKA) is often marketed as being able to speed up healing times over standard invasive surgery (SIS) through the medial parapatellar approach. The advantages of these minimally invasive approaches, however, are not yet definitively established. A meta-analysis of studies comparing peri-operative and post-operative differences and long-term complications of MIS versus SIS for TKA was conducted.

METHODS

This meta-analysis was conducted following the PRISMA guidelines. The Pubmed, Google Scholar, Scopus, and Embase databases were accessed in September 2020. All clinical trials comparing minimally-invasive versus standard approaches for TKA were considered. Only studies reporting quantitative data under the outcomes of interest were included. Methodological quality assessment was performed using the PEDro appraisal score.

RESULTS

This meta-analysis covers a total of 38 studies (3296 procedures), with a mean 21.3 ± 24.3 months of follow-up. The MIS group had shorter hospitalization times, lower values of total estimated blood loss, quicker times of straight-leg raise, greater values for range of motion, higher scores on the Knee Society Clinical Rating System (KSS) and its related Function Subscale (KSFS). Pain scores, anterior knee pain and revision rate were similar between MIS and SIS. SIS allowed a quicker surgical duration.

CONCLUSION

The present meta-analysis encourages the use of minimally invasive techniques for total knee arthroplasty. However, MIS TKA is technically demanding and requires a long learning curve.

LEVEL OF EVIDENCE

III, meta-analysis of clinical trials.

Analysis of learning curve of minimally invasive total knee arthroplasty: A single surgeon's experience with 4017 cases over a 9-year period

BACKGROUND

To evaluate a single surgeon's experience with minimally invasive total knee arthroplasty (MIS-TKA) and report the 9-year learning curve and trends in clinical outcomes based on assessment of surgical skills, radiographic alignments, and patient's function scores.

METHODS

This retrospective study included a total of 4107 knees from 3403 patients undergoing bilateral or unilateral MIS-TKA between March 2004 and February 2013. MIS-TKA was performed through a modified mini-midvastus approach. Postsurgical care regime was standardized for all patients. Data of consecutive 3-month intervals were collected and compared for changes of trends in outcomes over time, including tourniquet time, intraoperative complications, radiographic alignment, the Knee Society Score (KSS), and functional scores.

RESULTS

Significant increase in the number of cases undergoing MIS-TKA per 3-month interval over the study period was observed. As surgeon's experience increased over time, tourniquet time was decreased from an average of 70 minutes to approximately 35 minutes. A total of 65 (1.68%) intraoperative complications were recorded and the frequencies were in a significant decreasing trend. The rate of malalignment was in a decreasing trend and steady desired alignment (6°) was achieved at the 15th three-month interval. KSS and function scores increased from 87.4 to 91.5 and 92.6 to 96.8, respectively.

CONCLUSION

Although a surgeon may become competent with MIS-TKA and achieved the preliminary learning curve within one year, experience accumulation continuously improved technical proficiency in MIS-TKA. This study confirmed significant improvements in surgical skills, postoperative alignment, and patients' function over time.

Risk of bias and the reporting of surgeons' experience in randomized controlled trials of total hip and total knee arthroplasty: A systematic review

RATIONALE, AIMS, AND OBJECTIVES

The potential bias introduced by surgeons' lack of comparable, relevant experience when performing the procedures in different arms of randomized controlled trials (RCTs) is arguably not well-managed or reported. The aim of this work was to review the frequency and nature with which surgeons' relevant experience is reported in RCTs of total hip (THA) and total knee arthroplasty (TKA), and to relate this to other risk of bias domains for this study design.

METHODS

A systematic review of RCTs comparing different minimally invasive procedures for TKA and comparisons of THA and hemiarthroplasty (HA). We searched MEDLINE, EMBASE, Science Citation Index, The Cochrane Library, Conference Proceedings Citation Index-Science (CPCI-S), Current Controlled Trials, and Clinical Trials.gov.

RESULTS

Seventy-five relevant RCTs were identified, 65 RCTs comparing minimally invasive with standard or other minimally invasive approaches to TKA, and 10 for THA compared with HA. Risk of bias based on the reported details of surgeons' relevant experience was categorized as low, high, or unclear. There was a clear distinction before and after 2009, with a substantial decrease in trials at high or unclear risk of bias after this date. There were no strong associations between this domain and other, standard risk of bias domains for RCTs.

CONCLUSION

The surgeons' relevant experience in an evaluated procedure is often poorly reported but has improved since 2009. The variable is not adequately captured by any other risk of bias domain. Future work should concentrate on conducting research on a much larger sample of studies and in procedures other than knee and hip arthroplasty.

Advances in Patellofemoral Arthroplasty

PURPOSE OF REVIEW

To describe current indications, implants, economic benefits, comparison to TKA, and functional and patient-reported outcomes of patellofemoral arthroplasty.

RECENT FINDINGS

Modern onlay implants and improved patient selection have allowed for recent improvements in short- and long-term outcomes after patellofemoral joint replacement surgery. Patellofemoral arthroplasty has become an increasingly utilized technique for the successful treatment of isolated patellofemoral arthritis. Advances in patient selection, implant design, and surgical technique have resulted in improved performance and longevity of these implants. Although short- and mid-term data for modern patellofemoral arthroplasties appear promising, further long-term clinical studies are needed to evaluate how new designs and technologies will affect patient outcomes and long-term implant performance.

Minimally invasive versus conventional approaches in total knee replacement/arthroplasty: A review of the literature

Background

Life expectancy lengthening and aging of population resulted in dramatically increase of patients with osteoarthritis. Total knee arthroplasty is widely used as the gold standard in order to relieve pain, correct deformity and restore function. A contemporary and controversial topic, is that of minimally invasive surgery for TKA. The minimally invasive approaches are based on the concept that they don't violate the extensor mechanism, resulting in earlier functional recovery, shorter hospital stay and enhanced patients' overall satisfaction. The most commonly used MIS approaches in TKA are the subvastus, midvastus and the quadriceps sparing. There is a debate regarding the efficacy and safety of these methods.

Objective

In this article we will review the current literature (randomized controlled trials and systematic reviews/meta-analyses) on MIS compared to traditional approach and analyse their clinical safety, efficacy and long-term results.

Design

Comparison of well-designed studies have tried to demonstrate the advantages/disadvantages, the clinical results and the complications of the MIS approaches compared to the MPP approach.

Results

MIS approaches seem to provide advantages in the immediate post-operative period accompanied by increased reports of complications. Consequently, further investigation based on large well-designed studies with long-term results are warranted to further clarify MIS effectiveness/safety.

Quality of cementation in conventional versus minimally invasive total knee arthroplasty

PURPOSE

To review the immediate postoperative radiographs of 108 patients following conventional or minimally invasive total knee arthroplasty (TKA) to assess the quality of cementation in terms of cement voids and retained cement.

METHODS

Records of 20 male and 88 female consecutive patients aged 50 to 83 (mean, 67.5) years who underwent conventional TKA (n=56) or computer-assisted minimally invasive TKA (n=52) for osteoarthritis by a single senior surgeon were reviewed. Immediate postoperative radiographs were assessed by a single blinded assessor for the quality of cementation in terms of cement void and retained cement in different zones of the femoral, tibial, and patellar components along the prosthesis-bone interface using the Knee Society total knee arthroplasty roentgenographic evaluation and scoring system.

RESULTS

The 2 groups were comparable in terms of baseline demographics as well as cement void and retained cement on the femoral, tibial, and patellar components, except that in the minimally invasive group, cement void beneath the anterior flange of the femoral component was wider (0.32 vs. 0 mm, p=0.001), and retained cement in the posterior or lateral aspects of the tibial component was more common (50.0% vs. 28.6%, p=0.018).

CONCLUSION

Minimally invasive TKA resulted in a wider cement void beneath the anterior flange of the femoral component and a higher rate of retained cement around the tibial component.

Computer-assisted total knee arthroplasty using mini midvastus or medial parapatellar approach technique: A prospective, randomized, international multicentre trial

Background

Despite the growing evidence in the literature there is still a lack of consensus regarding the use of minimally invasive surgical technique (MIS) in total knee arthroplasty (TKA).

Methods

A prospective, randomized, international multicentre trial including 69 patients was performed to compare computer-assisted TKA (CAS-TKA) using either mini-midvastus (MIS group) or standard medial parapatellar approach (conventional group).

Patients from 3 centers (Maastricht, Zwickau, Adelaide) with end-stage osteoarthritis of the knee were randomized to either an MIS group with dedicated instrumentation or a conventional group to receive cruciate retaining CAS-TKA without patella resurfacing. The primary outcome was to compare post operative pain and range of motion (ROM). The secondary outcome was to measure the duration of surgery, blood loss, chair rise test, quadriceps strength, anterior knee pain, Knee Society Score (KSS),WOMAC scores, mechanical leg axis and component alignment.

Results

Patients in the MIS group (3.97 ± 2.16) had significant more pain at 2 weeks than patients in the conventional group (2.77 ± 1.43) p = 0.003. There was no significant difference in any of the other primary outcome parameters. Surgery time was significantly longer (p < 0.001) and there were significantly higher blood loss (p = 0.002) in the MIS group as compared to the conventional group. The difference of the mean mechanical leg alignment between the groups was not statistically significant (–0.43° (95 % CI –1.50 – 0.64); p = 0.43).

There was no significant difference of component alignment between the two surgical groups with respect to flexion/extension (p = 0.269), varus/valgus (p = 0.653) or rotational alignment (p = 0.485) of the femur component and varus valgus alignment (p = 0.778) or posterior slope (p = 0.164) of the tibial component.

Conclusion

There was no advantage of the MIS approach compared to a conventional approach CAS-TKA in any of the primary outcome measurements assessed, however the MIS approach was associated with longer surgical time and greater blood loss. MIS-TKA in combination with computer navigation is safe in terms of implant positioning.

Trial registration number

ClinicalTrials.gov NCT02625311 8 December 2015

The Patient's Perception Does Not Differ Following Subvastus and Medial Parapatellar Approaches in Total Knee Arthroplasty: A Simultaneous Bilateral Randomized Study

This simultaneous bilateral randomized study investigated whether patients would perceive the difference between the subvastus approach (SVA) and the medial parapatellar approach (MPA) after total knee arthroplasty (TKA). In 50 patients scheduled to undergo same-day bilateral TKA, one knee was randomly assigned to SVA and the other to MPA. Patient-reported measures (pain, Western Ontario McMaster University Osteoarthritis Index score, and side preference) and physician-assessed measures (isokinetic muscle strength, range of motion, and Knee Society score) were compared. No differences were observed in the patient-reported measures and physician-assessed measures, with the exception of greater quadriceps strength at postoperative 1 week in knees that underwent SVA. Patients receiving contemporary perioperative management after same-day bilateral TKA do not perceive any difference between knees that underwent SVA or MPA.

Are There Any Clinical and Radiographic Differences Between Quadriceps-sparing and Mini-medial Parapatellar Approaches in Total Knee Arthroplasty After a Minimum 5 Years of Follow-up?

BACKGROUND

Although the early clinical outcomes of total knee arthroplasty (TKA) using minimally invasive surgery techniques have been widely described, data on the mid- to long-term outcomes are limited. We designed a retrospective study to compare the two most common TKA techniques - The modified quadriceps-sparing (m-QS) approach and the mini-medial parapatellar (MMP) approach - In terms of the clinical and radiographic parameters, over a minimum follow-up period of 5 years.

METHODS

The m-QS approach was used in 31 knees and the MMP approach, in 36 knees. Knees in both groups were compared for component position and alignment, knee alignment, length of the skin incision, range of motion, Visual Analog Scale score, muscle torques, Knee Society Score, Western Ontario and McMaster Universities Osteoarthritis Index, and number of complications.

RESULTS

There were no major intergroup differences in any of the clinical and radiographic outcomes assessed at the final follow-up examination.

CONCLUSIONS

On the basis of numbers studied, the m-QS group, which requires more technique, showed equivalent results with the MMP group in the postoperative 5 years. Preservation of the extensor mechanism in the m-QS approach could not ensure any improvement in the clinical outcomes during the mid-term follow-up duration.

A meta-analysis of minimally invasive and conventional medial parapatella approaches for primary total knee arthroplasty

PURPOSE

Minimally invasive surgical (MIS) approaches for total knee arthroplasty (TKA) have become increasingly popular for doctors and patients. They have argued that it decreases post-operative pain, accelerates functional recovery and increases patient satisfaction due to less injury. However, critics are concerned about TKA's possible effects on component position and with complications, considering the procedure's limited exposure. The purpose of this study was to summarise the best evidence in comparing the clinical and radiological outcomes between MIS and a conventional approach in TKA.

METHODS

Electronic databases were systematically searched to identify relevant randomised controlled trials (RCTs). Our search strategy followed the requirements of the Cochrane Library Handbook. Methodological quality was assessed, and data were extracted independently by two authors.

RESULTS

Thirty studies, including 2,536 TKAs, were reviewed: 1,259 minimally invasive and 1,277 conventional exposure TKAs. The results showed that while the MIS group had longer operation times and tourniquet times, it had superior outcomes in KSS (objective and total), range of motion, flexion range of motion, flexion 90° day, straight leg-raising day, total blood loss and decrease in haemoglobin. However, wound-healing problems occurred more frequently in the MIS group. There were no statistically significant differences in other clinical or radiological outcomes between the MIS and conventional groups in TKA.

CONCLUSION

The preliminary results indicate that the MIS approach provides an alternative to the conventional approach, with earlier rehabilitation but no malpositioning or severe complications. Wound-healing problems can be treated easily and effectively, and the risk also decreases as surgeons become more experienced, and more user-friendly instruments are invented. Potential benefits in medium- and long-term outcomes require larger, multicentre and well-conducted RCTs to confirm.

LEVEL OF EVIDENCE

Therapeutic study, Level II.

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 1-2weeks but also was associated with longer operative time; the subvastus approach showed better outcomes in knee range of motion at postoperative 1week, straight leg raise and lateral retinacular release.

Short Term Recovery of Function following Total Knee Arthroplasty: A Randomised Study of the Medial Parapatellar and Midvastus Approaches

This pilot double blind randomised controlled study aimed to investigate whether the midvastus (MV) approach without patellar eversion in total knee arthroplasty (TKA) resulted in improved recovery of function compared to the medial parapatellar (MP) approach. Patients were randomly allocated to either the MV approach or the MP approach. Achievements of inpatient mobility milestones were recorded. Knee kinematics, muscle strength, Timed Up and Go, WOMAC, and daily step count were assessed before and up to six months after surgery. Cohen's effect size d was calculated to inform the sample size in future trials. Twenty-eight participants (16 males, 12 females) participated. Patient mobility milestones such as straight leg raise were achieved on average 1.3 days (95% CI −3.4 to 0.7, d = 0.63) earlier in the MV group. Knee extensor strength at 6 weeks after surgery was higher (95% CI −0.38 to 0.61, d = 0.73) in the MV group. No trends for differences between the groups were observed in knee kinematics, TUG, WOMAC, or step count. Our results suggest a short term advantage in the first 6 weeks after surgery of the MV approach over the MP approach, but a larger study is required to confirm these findings. This trial is registered with NCT056445.

Minimally invasive midvastus versus standard parapatellar approach in total knee arthroplasty: a meta-analysis of randomized controlled trials

Objective

Minimally invasive midvastus approach (mini-midvastus) has been widely used in total knee arthroplasty (TKA). However, the clinical effects still remains controversial. This meta-analysis was based on randomized controlled trials (RCTs) aiming to quantitatively analyze the clinical efficacy of mini-midvastus versus standard parapatellar approach in TKA.

Methods

This meta-analysis was performed according to the PRISMA guidelines. A literature search for the eligible RCTs was carried out in the databases of PubMed, the Cochrane library, EMBASE and Web of Science. Two independent reviewers independently completed the study selection, data extraction, and the assessment of methodological quality. Meta-analysis was conducted by the RevMan 5.2 software.

Results

A total of 18 RCTs (937 patients with 1093 TKAs) published from 2007 to 2013 were included. The meta-analysis suggested that the mini-midvastus approach significantly improved knee range of motion (ROM) and decreased visual analog score (VAS) at postoperative 1–2 weeks (p<0.05), and there were no statistical differences in terms of knee society score (KSS) (6 weeks to 1 year), VAS (6 weeks to 6 months), ROM (6 weeks to 6 months), lateral retinacular release, blood loss, straight leg raise, hospital stay and postoperative complications between the mini-midvastus and standard parapatellar approach (p>0.05). However, the operative time was significantly longer when performing the mini-midvastus group than the parapartellar approach (p<0.05).

Conclusion

This meta-analysis found that compared with the standard parapatellar approach, the mini-midvastus approach had early advantages in the VAS and ROM, but had the disadvantage in the operative time.

Level of Evidence

Therapeutic study Level I.

Mini-midvastus versus mini-medial parapatellar approach for minimally invasive total knee arthroplasty: outcomes pendulum is at equilibrium

Comparisons between mini-midvastus (mMV) and mini-medial parapatellar approach (mMPP) for total knee arthroplasty (TKA) have reported variable results. We compared two approaches with minimum two year follow up. Forty consecutive patients who underwent staged bilateral TKA were prospectively randomized for mMPP approach in one knee and mMV approach in the other. Clinical parameters (muscle strength, pain, ROM, Knee Society Score) and surgic.l parameters (duration of surgery, blood loss, lateral releases) were assessed at 2, 6, 12 weeks and 6, 12, 24 months postoperatively. Clinical outcomes revealed inconsistent pattern of differences at various intervals. Surgical outcomes were not different. There were no major differences in outcomes between the two approaches. We recommend someone use surgical approach with which they are most familiar.