Subvastus versus medial parapatellar approach in total knee arthroplasty

The subvastus approach for total knee replacement was compared with the standard medial parapatellar approach in terms of postoperative knee scores and quadriceps strength. Two groups of patients with similar characteristics were formed: the first group consisted of 12 knees of 9 patients who were implanted via the medial parapatellar approach, and for the second group the subvastus approach was used in 10 knees of 10 patients. The groups' knee scores and quadriceps strength were compared preoperatively and postoperatively at week 6, months 3 and 6. The knee scores improved similarly in both groups, but the change was more pronounced in the subvastus group. Quadriceps strength was greater in the subvastus group at postoperative week 6, but there was no significant difference between the groups in months 3 and 6. It was concluded that although the subvastus approach offers greater quadriceps strength in the early postoperative period, it has no significant advantage in this aspect over the medial parapatellar approach.     

Comparison of the subvastus and paramedian surgical approaches in bilateral knee arthroplasty

A prospective randomized study was performed on 20 patients undergoing one-stage bilateral knee arthroplasty. One knee was exposed using a standard median parapatellar arthrotomy and the other knee with a subvastus arthrotomy. All patients underwent quantitative strength testing before surgery and at I week, I month, and 3 months after surgery. The knees were also evaluated for range of motion, and patients, who were blinded as to the approach used, completed questionnaires at each evaluation period as to their preference, if any, regarding knee pain and level of function. There was no difference in the range of motion between knees exposed with the paramedian or subvastus arthrotomy at any time period. The subvastus knees demonstrated significantly greater strength at the 1-week and 1-month intervals, but there was no strength difference at the 3-month interval. There were more lateral releases performed in the paramedium knees, and three minor complications were related to the subvastus approach. Patients who expressed a preference chose the subvastus knee 4: 1 over the paramedian knee. The subvastus approach offers a reasonable alternative to the paramedian arthrotomy and preserves greater quadriceps strength in the early postoperative period.     

Muscle torques in total knee arthroplasty with subvastus and parapatellar approaches

The current study was designed to compare muscle torques when using the subvastus and parapatellar approaches for unilateral total knee arthroplasty. Twelve female patients had unilateral total knee arthroplasty with the subvastus approach from January 1997 to June 1998. The historic control group consisted of 16 female patients who had unilateral total knee arthroplasty with the parapatellar approach from July 1994 to January 1997. Six and 12 months after surgery, a Cybex dynamometer was used to measure isometric and isokinetic muscle strength. Two parameters were used to compare the two approaches, the first parameter was the difference in peak torque between the surgically treated knee and the baseline value for the healthy knee, and the second parameter was the hamstring to quadriceps peak-torque ratio, again using the value for the healthy knee as baseline. The subvastus approach resulted in an initial higher peak torque in the quadriceps 6 months after surgery, but this difference became insignificant 12 months postoperative. Using the subvastus approach, the hamstring to quadriceps peak-torque ratio reached the normal range (0.50-0.80) sooner than was the case using the parapatellar approach. There is a phenomenon of cross adaptation of the untreated knee to the surgically treated knee, and knees operated on by the subvastus approach showed functional recovery at an earlier date than those operated on by the parapatellar approach.     

Comparison of early postoperative rehabilitation outcome following total knee arthroplasty using different surgical approaches and instrumentation

PURPOSE: To assess early postoperative rehabilitation outcome following computer-assisted total knee arthroplasty (TKA) or standard instrumentation TKA using a medial parapatellar or subvastus approach. METHODS: A prospective controlled trial of 70 consecutive patients undergoing TKA with a low contact stress rotating platform prosthesis was conducted. Patients were randomised to receive surgery with either computer navigation or standard instrumentation. A medial parapatellar or subvastus approach was used according to the surgeons' preference. Outcome measures included preoperative knee function, intra-operative factors, and postoperative rehabilitation. RESULTS: Duration of surgery was significantly longer when using computer navigation; however, operating time decreased with greater experience. A higher incidence and duration of early postoperative quadriceps dysfunction was associated with computer-assisted TKA through the medial parapatellar approach than through the subvastus approach or TKA performed with standard instrumentation. No patient who received surgery through the subvastus approach had a lag of more than 20 degrees, at 48 hours postoperatively, regardless of the instrumentation used. CONCLUSION: Computer-assisted TKA through a medial parapatellar approach was associated with delayed recovery of the quadriceps during early postoperative rehabilitation. This was due to the additional quadriceps dissection required to place the femoral tracking array. The subvastus approach is therefore recommended for computer-assisted TKA.     

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

The purpose of this study was to compare the clinical results of total knee arthroplasty (TKA) in the early and late postoperative period using subvastus and medial parapatellar approach. A prospective randomized controlled study was conducted in a group of 169 patients (180 TKAs) with 2-year follow-up. Patients were divided into a study group (97 TKAs) with a subvastus approach and a control group (83 TKAs) with a parapatellar approach. Assessment of the results of both operating approaches was based on functional, clinical Knee Society Score, and pain (visual analog scale). Patients in the subvastus group achieved full active extension, better range of motion, and better Knee Society Score results at 12 days, 6 weeks, and 12 weeks earlier than patients in the medial parapatellar group. They also had less pain at 12 days. No statistically significant differences existed between assessed end points in both groups at 24- and 52-weeks, and 24-months postoperatively. The subvastus approach has given patients better early clinical results; however, at longer follow-up, both groups had similar outcomes. The potential benefits of the subvastus approach are: protection of the extensor mechanism from damage, less risk of damaging the blood supply to the patella, earlier clinical recovery, and less pain in the early postoperative period. The subvastus approach is an alternative to the standard medial parapatellar approach in TKA. It can be used with equally good results, especially taking into consideration positive clinical aspects in the early postoperative period.     

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 (Southern) approach for primary total knee arthroplasty

The subvastus or Southern approach to the knee had been described as early as 1929 but is not found in standard modern orthopedic textbooks. This approach for primary total knee arthroplasty (TKA) preserves the integrity of the extensor mechanism and maintains the vascular supply to the patella. To appreciate the potential benefits of this approach, a complete understanding of the surgical anatomy is essential. The benefits of the subvastus approach make it a valuable technique for primary TKA.     

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.     

Subvastus approach for total knee arthroplasty: a prospective, randomized, and observer-blinded trial

A prospective, randomized, and blinded trial was conducted with 89 consecutive primary knee arthroplasties comparing standard medial parapatellar arthrotomy with the subvastus approach. All patients received the same prosthesis (Insall-Burstein II) inserted by one surgeon using an identical technique with the only difference being the approach. The parapatellar approach (group I) was used in 43 knees, and in the remaining 46 knees the subvastus approach (group II) was used. Assessment revealed significantly earlier return of straight-leg raise (3.2 days vs 5.8 days, P <.001), lower consumption of opiates in the first week (78 mg vs 102 mg, P <.001), less blood loss (527 mL vs 748 mL, P <.001), and greater knee flexion at 1 week (78 degrees vs 55 degrees, P <.001) in group II (subvastus approach). The subvastus approach offers early advantages over the standard parapatellar arthrotomy. It preserves the integrity of the vastus medialis and peripatellar plexus of vessels. We advise its wider use in primary total knee arthroplasty.     

Subvastus and medial parapatellar approaches in total knee arthroplasty

This retrospective study compared the outcome of two consecutive groups of patients having primary total knee arthroplasty. The arthroplasties were performed in the first group (169 arthroplasties in 143 patients) from 1988 to 1992 using a medial parapatellar approach, and in the second group (167 arthroplasties in 148 patients) from 1992 to 1996 using a subvastus approach. The patient outcomes were evaluated at 6 months, and were based on clinical and radiographic measures, occurrence of intraoperative lateral retinacular release, and incidence of postoperative patellar subluxation. There were no significant differences between the two groups for range of motion, Knee Society knee and function scores, and stair climbing ability. The patella tracked centrally in significantly more knees with the subvastus approach (139 of 167 knees, 83%) than with the parapatellar approach (107 of 169 knees, 63%). There were significantly fewer knees in the subvastus group requiring a lateral retinacular release (62 of 167 knees, 37%), compared with the parapatellar group (113 of 169 knees, 67%). The authors concluded that the subvastus approach led to improved patellar tracking and stability. Although the surgical and rehabilitative protocols were identical for both groups, the results may have been affected by changing circumstances during the 9-year period of the study.     

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.     

Large thigh girth is a relative contraindication for the subvastus approach in primary total knee arthroplasty

The purpose of this study was to determine the thigh girth cutoff limit for the subvastus approach in primary total knee arthroplasty. One hundred forty-three consecutive total knee arthroplasties were done using the subvastus approach by one surgeon. The larger the thigh girth, the higher the risk for inability to evert the patella. We found that patients with a thigh girth greater than 55 cm had 27.212 times higher risk for inability to evert the patella during the subvastus approach as compared with patients with a small thigh girth (ie, <45 cm; odds ratio = 27.212; 95% confidence interval = 4.394-168.530). If we could not evert the patella in patients with a large thigh girth, although we could slide the patella, the extensor mechanism and excessive soft tissues were obstacles to the procedure. We recommend that another approach for patients with a thigh girth greater than 55 cm be used.     

Comparison of the modified subvastus and medial parapatellar approaches in total knee arthroplasty

In this paper, we evaluated the difference between the modified subvastus approach and the medial parapatellar approach in total knee arthroplasty(TKA). We assessed the time of active straight-leg raise (SLR) post-operatively and the range of flexion of the operated knee at the tenth post-operative day, 6 weeks and 6 months, 12 months and 3 years. We investigated the degree of the patellar tilt and subluxation 24 months post-operatively. The patients who underwent the modified subvastus approach performed active SLR earlier (mean 0.5 days) than the medial parapatellar approach patients (mean 2.2 days). Knee flexion was better at the tenth post-operative day in the modified subvastus approach group compared to the medial parapatellar approach group. There was no statistical difference between the two groups with regard to the patellar tilt and subluxation. We conclude that the modified subvastus approach is recommendable in primary TKA.

---

Résumé  Nous avons évalué la différence entre l’abord médial para patellaire et l’abord modifié subvastus lors de la mise en place d’une prothèse totale du genou. Nous avons apprécié le temps de récupération post-opératoire de l’extension active du genou et le degré de flexion de celui-ci à 10 jours, 6 semaines, 6, 12 et 36 mois. Nous avons également exploré les complications rotuliennes, notamment subluxations à 24 mois. Les patients ayant bénéficié d’un abord subvastus récupèrent une extension active plus précoce (en moyenne de 0,5 jours), contre 2,2 jours pour l’abord médian. L’amélioration de la flexion du genou est également meilleure à 10 jours post-opératoire dans ce groupe. Il n’y a pas de différence significative entre ces deux groupes en ce qui concerne les problèmes rotuliens. Nous pensons que l’abord subvastus est à recommander dans la mise en place d’une prothèse totale du genou.

     

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.     

Factors affecting wound ooze in total knee replacement

INTRODUCTION

Wound ooze is common following total knee arthroplasty (TKA) and persistent wound infection is a risk factor for infection, and increased length and cost of hospitalisation.

PATIENTS AND METHODS

We undertook a prospective study to assess the effect of tourniquet time, peri-articular local anaesthesia and surgical approach on wound oozing after TKA.

RESULTS

The medial parapatellar approach was used in 59 patients (77%) and subvastus in 18 patients (23%). Peri-articular local anaesthesia (0.25% Bupivacaine with 1:1,000,000 adrenalin) was used in 34 patients (44%). The mean tourniquet time was 83 min (range, 38–125 min). We found a significant association between cessation of oozing and peri-articular local anaesthesia (P = 0.003), length of the tourniquet time (P = 0.03) and the subvastus approach (P = 0.01).

CONCLUSIONS

Peri-articular local anaesthesia, the subvastus approach and shorter tourniquet time were all associated with less wound oozing after total knee arthroplasty.     

Early results of subvastus versus medial parapatellar approach in primary total knee arthroplasty

Introduction To evaluate the clinical and radiographic results immediately after total knee arthroplasty, we compared the parapatellar and subvastus approach.Materials and methods Fifty-two patients with osteoarthritis were randomly assigned to two groups. The measurement was based on clinical and radiographic features.Results There was a significant difference in passive range of motion. Patients in the subvastus approach group revealed a full knee extension and flexion of 90° significantly earlier than those in the parapatellar group. However, on the day of discharge, both groups were comparable. Radiological assessment revealed analogous results in both groups. Correction of varus or valgus deformity was required in 48 patients.Conclusion Regardless of the surgical approach, the anteroposterior tibial femoral angle improved significantly in both groups. Concerning pain, operation time, blood loss, blood substitution and complications, no major differences could be seen.     

Total knee arthroplasty using subvastus approach in stiff knee: A retrospective analysis of 110 cases

Background:

Subvastus approach used in total knee arthroplasty (TKA) is known to produce an earlier recovery but is not commonly utilized for TKA when the preoperative range of motion (ROM) of the knee is limited. Subvastus approach is known for its ability to give earlier recovery due to less postoperative pain and early mobilization (due to rapid quadriceps recovery). Subvastus approach is considered as a relative contraindication for TKA in knees with limited ROM due to difficulty in exposure which can increase risk of complications such as patellar tendon avulsion or medial collateral injury. Short stature and obesity are also relative contraindications. Tarabichi successfully used subvastus approach in knees with limited preoperative ROM. However, there are no large series in literature with the experience of the subvatus approach in knees with limited preoperative ROM. We are presenting our experience of the subvastus approach for TKA in knees with limited ROM.

Materials and Methods:

We conducted retrospective analysis of patients with limited preoperative ROM (flexion ≤90°) of the knee who underwent TKA using subvastus approach and presenting the 2 years results. There were a total 84 patients (110 knees) with mean age 64 (range 49–79 years) years. The mean preoperative flexion was 72° (range 40°–90°) with a total ROM of 64° (range 36°–90°).

Results:

Postoperatively knee flexion improved by mean 38° (P < 0.05) which was significant as assed by Student''s t- test. The mean knee society score improved from 36 (range 20–60) to 80 (range 70–90) postoperatively (P < 0.05). There was one case of partial avulsion of patellar tendon from the tibial tubercle.

Conclusions:

We concluded that satisfactory results of TKA can be obtained in knees with limited preoperative ROM using subvastus approach maintaining the advantages of early mobilization.     

Comparative Efficacy of the Different Surgical Approaches in Total Knee Arthroplasty: A Systematic-Review and Network Meta-Analysis

BackgroundSeveral surgical approaches including midvastus, subvastus, mini-parapatellar, quadriceps-sparring (QS) and parapatellar are currently used to perform total knee arthroplasty (TKA). Since none of published study exhibited a simultaneous comparison of all of them, a network meta-analysis has been conducted to compare the most widely used knee surgical approaches regarding the improvement of functional outcomes and the range of motion (ROM).MethodsRandomised controlled trials (RCTs) comparing TKA approaches were searched in electronic databases, major orthopedics journals, and oral communications, ClinicalTrials.gov and WHO International Clinical Trials Registry Platform until May 1st, 2020. Two reviewers independently selected trials and extracted data. The primary outcomes were functional scores at 6 months post-surgeryevaluated by KSS and WOMAC, and the ROM.ResultsSixty RCTs involving 5042 patients with 5107 TKA were included. No significant differences between different approaches were found for the KSS assessment or the WOMAC at 6 months. The mean of ROM at 6 months post-surgery were higher in the subvastus group than in all the others surgical approaches. The difference of ROM with subvastus approach was 7.3° (95% CI ?14.1 to ?0.1) with the midvastus approach, 11.1° (95% CI ?18.7 to ?2.8) with mini-parapatellar, 8.9° (95% CI ?14.2 to ?3.1) with standard parapatellar, and 9.2° (95% CI ?16.1 to ?1.8) with QS.ConclusionNo differences were found in functional outcomes over short or medium terms but subvastus seemed to increase the ROM at 6 months post-surgery. Until or unless future studies can demonstrate a long-term benefit, based on these results all studied surgical approaches to perform a TKA are equal.Level of EvidenceNetwork meta-analysis. Level 1.     

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.     

股内侧肌下方入路并3D打印导板辅助全膝关节置换术的临床应用

目的评估股内侧肌下方入路并3D打印导板辅助全膝关节置换术的治疗效果。 方法回顾分析2015年3月至2016年3月沈阳市骨科医院关节外科应用股内侧肌下方入路并3D导板辅助全膝关节置换术治疗的骨关节炎患者63例,分别于术前、术后3个月进行视觉模拟评分（VAS评分）、膝关节功能评分（HSS评分）及髌骨Feller评分的评估。并于术前、术后3个月及6个月对患者股四头肌肌力及膝关节活动度进行评定。于术前、术后1个月进行伸直位Q角及其髌骨外推Q角,屈曲30°位Q角及其髌骨外推Q角的测量。 结果所有手术均顺利完成,63例患者均获完整随访,随访时间12~18个月,平均随访（14.5±2.7）个月。患者术后VAS评分[（1.8±0.4）分]、HSS评分[（93±6）分]和髌骨Feller评分[（26±4）分]较术前[（6.8±2.2、37±6、16±6）分]有明显改善（t=18.223,t=-51.741,t=-11.485,P<0.05）;术后6个月患者股四头肌肌力[（80±8）分]较术前[（74±8）分]有改善,差异有统计学意义（F=20.771,P<0.05）。患者术后3个月膝关节屈伸活动范围[屈：（118±5）°,伸：（1.0±0.9）°]较术前[屈：（80±14）°,伸：（3.8±1.8）°]有改善,差异具有统计学意义（F=306.062,F=105.050,P<0.05）。伸直位和屈曲30°位Q角及其髌骨外推Q角,以及两种状态下Q角差值,术后较术前均有明显改善,差异均有统计学意义（伸直位：t=20.489,t=6.753,t=4.891,屈曲位：t=21.497,t=2.853,t=5.698,P<0.05）。 结论应用股内侧肌下方入路并3D打印导板辅助下完成人工全膝关节置换术,创伤小、效果好、并发症少。