Subvastus and medial parapatellar approaches in TKA: comparison of functional results

Functional Outcome of Subvastus versus Medial Parapatellar Approaches for Total Knee Replacement in Patients with Knee Osteoarthritis: A Prospective Cohort Study

Background

Subvastus approach and medial parapatellar approach are two major approaches for total knee replacement (TKR). There is no global consensus on the superiority of either approach in terms of functional outcomes.

Objective

The present study aimed to evaluate the functional outcome of TKR through subvastus approach and medial parapatellar approach by using patient-reported scores at 3-, 6-, and 12-month post-operative follow-ups.

Methods

This prospective cohort follow-up study included patients with knee osteoarthritis who underwent elective primary TKR either through the subvastus or medial parapatellar approaches at King Abdullah Medical City, Makkah city, Kingdom of Saudi Arabia, from January 2019 to December 2022. Scores from the self-reported Oxford Knee Score (OKS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were compared in the two groups of patients at 3-, 6-, and 12-month post-operative follow-ups.

Results

A total of 98 patients were included, of which 37 underwent TKR through the subvastus approach and 61 through the medial parapatellar approach. There was an overall significant change over time in both WOMAC and OKS scores (P < 0.001). Patients who underwent the subvastus approach had significantly higher mean of WOMAC and OKS than patients with the medial parapatellar approach at the 3- and 6-month follow-ups (P < 0.05), but not at the 12-month follow-up.

Conclusions

For TKR, the medial parapatellar approach results in better functional outcomes at the 3- and 6- month follow-up periods compared with the subvastus approach.

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.

Subvastus Exposure Compared to Parapatellar Approach in Navigated Sequential Bilateral Total Knee Arthroplasty (SBTKA): A Prospective Randomized Study

Subvastus approach preserves the quadriceps mechanism and may lead to improved early functional outcomes as compared with a parapatellar approach in primary knee arthroplasty. We performed a prospective randomized study to test the hypothesis if subvastus approach improves patient- and physician-reported outcomes in navigated sequential bilateral knee arthroplasty when compared with the standard parapatellar approach. A total of 93 patients were allotted in each group after power analysis and randomization done by computer-generated sequence: group S by subvastus approach and control group P by parapatellar approach. The patient's ability to walk without an aid, range of motion, blood loss, tourniquet time, complications, Knee Society Score (KSS), Knee Society Functional Score (KSFS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee Injury and Osteoarthritis Outcome Score (KOOS), High Flexion Knee Score (HFKS), and visual analog scale (VAS) for pain were recorded preoperatively and postoperatively at 2 and 6 weeks and 3, 6, and 12 months. Final follow-up was done at 2 years. There was no statistical difference in the patient's ability to achieve a straight leg raise (p = 0.88), walk without an aid (p = 0.25), leaving pain medication (p = 0.48), and mean duration of hospital stay (p = 0.58) between both groups. There was no difference in KSS, FS, KOOS, WOMAC, HFKS, and VAS at 2 weeks and later follow-ups. There was no significant difference in range of motion or lateral retinacular release in both groups. Blood loss was significantly less in group S (p < 0.05), but there was a higher rate of proximal wound dehiscence and delayed healing in subvastus group (p = 0.03). Subvastus approach does not improve patient- and physician-reported outcome measures except blood loss in computer-navigated sequential bilateral knee arthroplasty and has an increased incidence of wound healing problems. The Level of evidence for the study is I.

Lateral parapatellar and subvastus approaches are superior to the medial parapatellar approach in terms of soft tissue perfusion

PURPOSE

The arthrotomy techniques of knee surgery may cause varying degrees of disruption to the tissue blood supply. The aim of this study was to investigate the effects of the medial parapatellar (MPPa), midvastus (MVa), subvastus (SVa) and lateral parapatellar (LPPa) approaches on regional tissue perfusion of the knee.

METHODS

In this experimental study, a total of 28 female rabbits were applied with four different arthrotomy techniques as Group MPPa, Group MVa, Group SVa and Group LPPa. The blood supply of the tissue around the knee was examined by scintigraphic imaging including the perfusion reserve and T _max, and biochemical alteration of the oxidative stress parameters including malondialdehyde (MDA), fluorescent oxidation products (FlOPs), and histopathological findings were evaluated on tissue samples after 3 weeks.

RESULTS

The perfusion reserve was increased in all four groups compared to the healthy, contralateral knees. In the Group LPPa, the vascularity was significantly increased compared to the Group MPPa (p = 0.006). In the examination of biochemical parameters, the increase in MDA levels was statistically significant in the Group MPPa compared with the Group LPPa (p = 0.004), and in the Group MVa compared with the Group LPPa (p = 0.006). The increase in the value of MDA levels was striking in the Group MPPa and Group MVa compared with the control group (p = 0.004, p = 0.004, respectively). The increase in another oxidative stress parameter, the tissue FlOPs levels, was statistically significant in the Group MPPa compared with the control group (p = 0.035).

CONCLUSION

The LPPa and SVa caused less oxidative stress and less disruption of the muscle blood supply, in biochemical and scintigraphic parameters, compared to the MPPa and MVa. Therefore, in clinical practice, the SVa is preferable to the MPPa and MVa in total knee arthroplasty and the LPPa should be preferred more frequently in selected cases with critical soft tissue viability.

Medial subvastus versus the medial parapatellar approach for total knee replacement: A systematic review and meta-analysis of randomized controlled trials

Twenty randomized controlled trials comprising 1893 primary total knee replacements were included in this review.

The subvastus approach conferred superior results for mean difference (MD) in time to regain an active straight leg raise (1.7 days, 95% confidence interval [CI] 1.0 to 2.3), visual analogue score for pain on day one (0.8 points on a scale out of 10, 95% CI 0.2 to 1.4) and total range of knee movement at one week (7°, 95% CI 3.2 to 10.7). The subvastus approach also resulted in fewer lateral releases (odds ratio 0.4, 95% CI 0.2 to 0.7) and less peri-operative blood loss (MD 57 mL, 95% CI 10.5 to 106.4) but prolonged surgical times (MD 9.7 min, 95% CI 3.9 to 15.6).

There was no difference in Knee Society Score at six weeks or one year, or the rate of adverse events including superficial or deep infection, deep vein thrombosis or knee stiffness requiring manipulation under anaesthesia.

This review demonstrates evidence of early post-operative benefits following the subvastus approach with equivalence between approaches thereafter.

Cite this article: EFORT Open Rev 2018;3:78-84. DOI: 10.1302/2058-5241.3.170030.

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.

Increased turn/amplitude parameters following subvastus approach in total knee arthroplasty

PURPOSE

To compare the improvement of the vastus medialis component of the quadriceps muscle electrophysiologically after the subvastus and medial parapatellar approaches in total knee arthroplasty (TKA).

METHODS

A total 26 patients that underwent primary unilateral in TKA were included into the study. TKAs were carried out via subvastus approach in 15 patients, while 11 patients were operated via medial parapatellar approach. The electrophysiological evaluations were carried out blindly with regard to the type of the surgical approach before the operation and at 6th week post-operatively. Non-surgical side was also evaluated as a control. Assessments were patellar tendon reflex analysis, motor unit potential analysis and interference pattern analysis (IPA) including turn-amplitude analysis and IPA during maximum contraction.

RESULTS

When they were compared to the pre-operative values, "the total mean amplitude" and "the mean turn/sec" parameters were significantly increased in group of subvastus approach (p = 0.017 and p = 0.009, respectively) at the post-operative 6th week. We would not be able to find any difference regarding the other electrophysiological parameters. There was also no significant difference between groups.

CONCLUSION

If there was no significant difference in all the electrophysiological parameters, the increase in turn-amplitude analysis in the group of subvastus approach would be considered as an indicator of a faster functional improvement of knee extensor mechanism in these cases.

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.

Faster quadriceps recovery with the far medial subvastus approach in minimally invasive total knee arthroplasty

PURPOSE

To identify whether less proximal muscle damage during minimally invasive surgery will allow faster recovery after total knee arthroplasty in comparison with a quadriceps incision approach. A limited medial parapatellar approach without tibial medial collateral ligament (MCL) release was compared to a subvastus approach without tibial medial collateral ligament release (far medial subvastus).

METHODS

One hundred and eighty patients were studied. In the mini-parapatellar group, ninety patients and in the far medial subvastus group, the remaining ninety patients were included. The evaluation was based on the Knee Society Score, VAS, morphine consumption, range of motion, time to straight leg raising, walking without aid, stairs and period of hospitalization. Alignment on full leg radiographs and component position on plain films were measured.

RESULTS

The far medial subvastus group showed faster recovery with earlier straight leg raising (1.7 ± 0.5 vs. 2.7 ± 0.4 days), postoperative weight bearing without aid (1.7 ± 0.6 vs. 2 ± 0.8 days) and stair negotiation (3 ± 0.4 vs. 4 ± 0.3 days) resulting in shorter length of stay (4 ± 0.5 vs. 5 ± 1.2 days). Comparable Knee Society Scores (88.5 ± 6.8 vs. 90 ± 10), Function Scores (90 ± 10) and alignment (5.4° ± 2.1° vs. 5.0° ± 2.4°) between the medial parapatellar and far medial subvastus group were observed at a follow-up of 24 months. An increase in operative time for the far medial subvastus was observed (55 ± 10.6 min vs. 67 ± 12 min tourniquet time) but without complications.

CONCLUSION

The MCL sparing far medial subvastus approach allows good surgical exposure, faster straight leg raising, full weight bearing without aid and shorter length of stay with most importantly no radiological malalignment.

LEVEL OF EVIDENCE

Therapeutic study, Level II.

A meta-analysis of the sub-vastus approach and medial parapatellar approach in total knee arthroplasty

PURPOSE

Both sub-vastus (SV) approach and standard medial parapatellar (MP) approach are performed in primary total knee arthroplasty (TKA). Proponents of SV approach stress its importance in decreasing lateral release and preserving function of the extensor mechanism with earlier rehabilitation. The purpose of this study was to summarize the best evidence to compare functional outcomes between SV approach and MP approach in TKA.

METHODS

All relevant randomized controlled trials and quasi-randomized controlled trails comparing SV approach and MP approach in primary TKA were included, and the search strategy followed the requirements of the Cochrane Library Handbook. Methodological quality was assessed, and data were extracted independently by two authors.

RESULTS

Ten studies involving 976 knees, which compared the clinical outcomes after TKA by SV approach and MP approach, were included. The results showed that the SV approach needed less lateral release (RR, 0.37; 95 % CI, 0.17-0.81; P = 0.01) and offered earlier straight leg raise (95 % CI, -3.11 to -0.69; P < 0.01) and superior knee flexion within 1 week postoperation (95 % CI, 1.96-8.20; P < 0.01) with no increase in the duration of surgery.

CONCLUSIONS

The preliminary results can be concluded that SV approach may provide an alternative to the MP approach with earlier rehabilitation and decreased lateral release rates in primary TKA; however, more high-quality randomized controlled trials should be designed to assess the medium and long-term outcomes between these two approaches.

LEVEL OF EVIDENCE

II.

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.

Subvastus versus medial parapatellar approach in total knee arthroplasty: meta-analysis

The subvastus and medial parapatellar approaches are 2 commonly performed techniques in total knee arthroplasty, but the optimal approach for total knee arthroplasty remains controversial. The purpose of this study was to compare the effectiveness and safety of the subvastus vs medial parapatellar approach.The PubMed, Embase, Cochrane Library, Inter-Services Intelligence Web of Knowledge, and Chinese Biomedical Literature databases were searched for eligible quasi-randomized, controlled and randomized, controlled trials. Two authors independently extracted data and assessed the methodological quality of the included studies according to the Cochrane handbook version 5.1.0. Statistical analysis was performed using Review Manager version 5.1 software. Eight randomized, controlled trials and 1 quasi-randomized, controlled trial involving 940 primary total knee arthroplasties were included for meta-analysis. Meta-analysis revealed significant differences favoring the subvastus group in Knee Society Score in terms of function at 4 to 6 weeks (weighted mean difference [WMD]=5.09; 95% confidence interval [CI], 3.08 to 7.09; P<.01) and knee score at 12 months (WMD=2.17; 95% CI, 0.01 to 4.34; P=.05) and lateral retinacular release (odds ratio=0.34; 95% CI, 0.14 to 0.79; P=.01) when compared with the medial parapatellar approach. However, both groups showed similar results in range of motion (P>.05), operative time (WMD=2.15; 95% CI, -3.61 to 7.35; P=.42), blood loss (WMD= -31.07; 95% CI, -91.89 to 29.75; P=.32), hospital stay (WMD= -0.18; 95% CI, -0.67 to 0.31; P=.47), and postoperative complications (P>.05).

Comparison of the Minimally Invasive and Standard Medial Parapatellar Approaches for Total Knee Arthroplasty: Systematic Review and Meta-Analysis

This systematic literature review analysed the efficacy of minimally invasive subvastus (SV) and midvastus (MV) approaches, compared with the standard medial parapatellar (MP) approach, for total knee arthroplasty. Fixed- and random-effect meta-analyses were performed to pool the results of primary studies assessing the mean difference of each clinical outcome. Length of hospital stay was significantly different between the MP and SV approaches, but not between the MP and MV approaches. Blood loss was significantly higher following MP compared with SV. The number of days to perform a straight-leg raise was significantly longer following MP than either MV or SV. In the first 6 months postsurgery, MV was associated with a better range of motion (ROM) than MP. No significant difference in ROM between MP and SV was apparent at 1 year postsurgery. Quadriceps muscle strength recovered significantly more slowly following MP compared with SV. Future studies should assess the efficacy of the quadriceps-sparing approach and compare minimally invasive approaches, assessing intrinsic postoperative differences.