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.

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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.

     

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.     

两种入路对人工全膝关节置换术后快速康复的影响

[目的]比较股内侧肌下入路(subvastus approach, SVA)与内侧髌旁入路(medial parapatellar approach,MPA)对人工全膝关节置换(TKA)术后快速康复的影响。[方法]前瞻性连续纳入拟行初次、单侧TKA手术的原发性膝骨关节炎患者80例,采用随机数字表法分为两组,40例患者采用SVA入路TKA,40例采用MPA入路TKA。比较两组患者切口长度、手术时间、术后引流量、依托考昔片追加量、直腿抬高时间、起始下地时间、运动和静息状态下疼痛视觉模拟评分(VAS评分)、膝关节活动度(ROM)和美国特种外科医院评分(HSS评分)。[结果] SVA组手术时间显著长于MPA组(P0.05),但SVA组在切口长度、依托考昔追加量、直腿抬高、下地行走时间等方面均显著优于MPA组(P0.05)。两组术前运动状态下VAS评分、膝ROM和HSS评分差异均无统计学意义(P0.05)。在疼痛方面,术后6 h、术后1 d、术后3 d静息状态下SVA组VAS评分均低于MPA组(P0.05),术后6 h、术后1 d、术后3 d、术后1周、术后1个月运动状态下SAV组VAS评分显著低于MPA组(P0.05),术后1周静息状态下和术后3个月运动状态下VAS评分两组间差异无统计学意义(P0.05)。在功能方面,术后3 d、术后1周、术后1个月SVA组膝ROM和HSS评分均高于MPA组(P0.05),而术后3个月两组间膝ROM及HSS评分差异无统计学意义(P0.05)。[结论]与MPA入路相比,SVA入路行TKA手术更有利于患者术后快速康复。     

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.     

Comparing outcomes of medial parapatellar and subvastus approaches in total knee arthroplasty: a randomized controlled trial

The medial parapatellar (MP) approach in total knee arthroplasty is more common, but the subvastus (SV) approach is less insulting to the quadriceps. Whether the SV approach affords better outcomes was investigated using 90 participants with knee osteoarthritis, randomized to receive either SV or MP approaches and followed for 18 months. The primary outcome was the American Knee Society Score (AKSS); secondary outcomes included pain, knee range, quadriceps lag, Oxford Knee Score, 3-m timed "Up and Go" test, days to straight leg raise, surgeon perceived difficulty, operation duration, and length of stay. Analysis (n = 76) revealed no significant difference in AKSS (P = .076) or other outcomes, except the following: AKSS Functional scores at 12 and 18 months, favoring the MP (P = .032 and P = .028 respectively); surgeon's perceived difficulty, favoring the MP (P = .001); and days to straight leg raise, favoring the SV (P = .044). This study found that the SV approach offers no clinical benefit over the MP approach.     

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.     

全膝关节置换术经股内侧肌下入路与经内侧髌旁入路临床疗效的META分析

[目的]系统评价经股内侧肌下入路行膝关节置换术的可行性及安全性。[方法]计算机检索Pub Med、EMbase、Cochrane图书馆、OVID/Medline和中国万方数据库。全面收集有关股内侧肌下入路对比传统内侧髌旁入路的临床随机对照研究,按Cochrane协作网提供的风险偏倚评估工具对文献的方法学偏倚进行评价,提取文献数据并使用Rev Man 5.3.0软件进行Meta分析。[结果]最终纳入13篇文献,其中12篇随机对照研究,1篇半随机对照研究,共1 246例膝关节。Meta分析结果显示在术后直腿抬高时间、早期KSS功能评分方面股内侧肌入路优于传统内侧髌旁入路,但在手术时间、术后疼痛、膝关节活动度及术后并发症的差异无统计学意义。[结论]与传统内侧髌旁入路相比,经股内侧肌入路行全膝关节置换在术后早期KSS功能评分及直腿抬高时间上有优势,但手术时间、术后疼痛、膝关节活动度及术后并发症差异无统计学意义。     

股内侧肌中间入路与内侧髌旁入路在初次全膝关节置换中的对比研究

目的对股内侧肌中间入路和内侧髌旁人路在全膝关节置换术（TKA）手术相关参数和术后早期康复的相关参数进行比较。方法自2004年3月～2006年3月将34例同期双膝TKA患者两侧膝关节的手术入路进行随机分配，一侧采用股内侧肌中间入路，另一侧采用内侧髌旁人路。比较两组的外科参数和临床参数，外科参数包括暴露的难易程度、手术时间、术中失血量和外侧支持带需要松解的比例。临床参数包括术后静息和运动时疼痛、直腿抬高时间、主动屈曲到90。的时间、术后膝关节活动度及并发症。结果两组手术时间无明显差异，与内侧髋旁人路比较采用股内侧肌中间入路一侧的膝关节术中失血较少[（286．0±29．8）mL／us．（368．0±35．8）mL，P〈0．05]，外翻膝需要做外侧支持带松解的比例较小（20％us 50％，P〈0．05），术后l周内疼痛较轻（P〈0．05），能较早地进行主动直腿抬高[（1．8±0．3）d us．（4．5±0．8）d，P〈0．01]，较早地屈曲到90^o[（3．2±0．8）d us（7．1±1．2）d，P〈0．01]，术后45d活动度改善较快[（107^o±20^o）us、（98^o±12^o），P〈0．05]。结论因为股内侧肌中间入路对伸膝装置和髌周血管丛的破坏较少，TKA后功能恢复早期，比内侧髌旁人路更具有优势。     

A comparison of the vastus splitting and median parapatellar approaches in total knee arthroplasty.

This prospective randomized study was undertaken to evaluate the vastus splitting approach as an alternative to the median parapatellar approach in primary total knee arthroplasty. Fifty-one knees in 42 patients were randomized preoperatively. Clinical parameters were evaluated preoperatively and at regular postoperative intervals. Electromyography was performed preoperatively and postoperatively to evaluate each approach relative to its effect on the innervation of the quadriceps mechanism. There were no significant preoperative differences. Postoperatively, there were no significant differences regarding strength, range of motion, knee scores, tourniquet time, proprioception, or patellar replacement. There were significantly more lateral releases performed and greater blood loss in the patients in the parapatellar group. The results of all preoperative electromyograms were normal, as were all of the results of postoperative electromyograms in the patients in the parapatellar group. However, the results of nine of 21 (43%) of the electromyograms performed postoperatively on patients who had the vastus splitting approach were abnormal. Significantly fewer lateral releases were performed and there was less blood loss in the patients in the vastus group. However, the postoperative electromyographic results revealed neurologic injuries in the vastus medialis muscle that only were present after the vastus splitting approach. The clinical significance of denervation of the vastus medialis muscle by the vastus approach remains to be determined by longer term clinical and electromyographic studies.     

Biochemical stress evaluation after medial parapatellar and subvastus approach in total knee replacement

Introduction

Even if different surgical approaches for total knee arthroplasty are well known since decades, the standard medial parapatellar incision remains the most common one; general agreement about significant advantages with minimally invasive techniques is lacking. Furthermore, the surgical stress effect on the organism has always been analyzed through blood inflammatory parameters. This study aim was to compare the standard and subvastus approaches, using the salivary cortisol in particular as measure for systemic surgery-related stress.

Methods

Fifteen operations were performed in a consecutive series; clinical (Knee Society Knee Scoring System., a questionnaire score, range of motion, tourniquet time, intra-operative bleeding) and biochemical factors (salivary and hematic cortisol, C-reactive protein, muscular creatine phosphokinase levels) were evaluated. The final follow-up was at two months after the operation.

Results

No significant differences were observed in most of the parameters; however, the subvastus group had a sharper and earlier functional improvement trend than the standard one. On the other side, it increased the CPK levels significantly.

Conclusions

In our experience, the medial subvastus approach, firstly associated with greater surgical stress, has then been characterized by a more favorable functional improvement trend. Moreover, the salivary cortisol measurement has proved to be a non-invasive and reliable method to evaluate the systemic surgery-related stress.

     

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.     

A prospective comparative study of the midvastus and medial parapatellar approaches for total knee arthroplasty in the early postoperative period

Introduction  

The commonest surgical approach for total knee arthroplasty is medial parapatellar approach. This involves splitting the quadriceps tendon and disrupts the extensor mechanism and this may potentially weaken it. The midvastus approach involves splitting the vastus medialis muscle instead of entering the quadriceps tendon; therefore, minimising interruption of the extensor mechanism without compromising the exposure of the knee.     

Lateral subvastus approach with tibial tubercle osteotomy for primary total knee arthroplasty: clinical outcome and complications compared to medial parapatellar approach

Purpose

The lateral subvastus approach (LSVA) with tibial tubercle osteotomy (TTO) is an alternative approach for total knee arthroplasty (TKA) in selected patients. The aim of this study was to compare clinical outcomes between LSV and medial parapatellar approaches for primary TKA and to investigate incidence of complications related to TTO.

Methods

A total of 580 patients with primary TKA, meeting the inclusion criteria, were treated at our hospital from February 2006 until February 2013. All patients’ data were included in the local arthroplasty register and were followed up 12 months postoperatively. The data set contains: demographic data, the WOMAC score, the KSS as well as knee flexion and complications related to tibial tubercle osteotomy.

Results

The clinical outcome after TKA using the LSVA combined with TTO was comparable with those using the medial standard approach 1 year postoperatively. Four patients (3.8 %) needed a revision due to complications related to tubercle osteotomy.

Conclusions

The LSVA is thus a viable alternative in cases of primary TKA if technical difficulties with the medial approach are anticipated. Applying precise surgical technique, the LSVA seems to be a safe and reproducible procedure.

     

Patellar tilt and subluxation following subvastus and parapatellar approach in total knee arthroplasty: Implication for surgical technique

Eighty-nine posterior-stabilized total knee arthroplasties (TKAs) were studied using a Merchant view to assess patellar tilt or subluxation. Forty TKAs were performed via the subvastus approach (SVA) and 49 via the standard parapatellar approach (PPA). Intraoperative tracking was assessed using a “no thumbs” test, and a lateral release was performed if necessary. Following the SVA, 40.0% of patellas tracked centrally compared to 44.9% for the PPA. With the SVA, a lateral release was necessary in 27.5% of procedures compared to 51.0% for the PPA. The data suggest that the no thumbs test may overestimate the need for lateral release following the PPA. Since there are fewer lateral releases following the SVA, reapproximation of the medial retinaculum to assess intraoperative tracking may result in fewer lateral releases being performed without adversely affecting patellar position. Medial tilting of the patella is also found to be common; 29.7% of the patellas tilted this way, including 40.0% of knees operated via the SVA. Why this occurs is unclear, but the incidence of medial tilting increased after posterior-stabilized TKA.     

Equivalent results of medial and lateral parapatellar approach for total knee arthroplasty in mild valgus deformities

Purpose

When performing total knee arthroplasty (TKA) in valgus knee deformities, a medial or lateral parapatellar approach can be performed, but the lateral approach is often considered technically more difficult. The purpose of this study was to compare intra-operative, early clinical and radiological outcomes of medial and lateral parapatellar approaches for TKA in the setting of moderate knee valgus (<10°).

Methods

We prospectively analysed 424 knees with pre-operative valgus deformity between 3° and 10° that underwent TKA over an 18-year period; 109 were treated with a medial approach and 315 with a lateral approach. Intra- and post-operative outcomes and complication rates after a minimum follow-up of one year were compared.

Results

Tourniquet (p?=?0.25) and surgical (p?=?0.62) time were similar between groups. The popliteus tendon was released more frequently in the medial-approach group (p?=?0.04), while the iliotibial band was released more frequently in the lateral-approach group (p?<?0.001). A tibial tuberosity osteotomy was performed more frequently in the lateral- than medial-approach group (p?=?0.003). No significant differences in limb alignment (p?=?0.78), or Knee Society Score (KSS) knee (p?=?0.32) and function (p?=?0.47) results were noted based on surgical approach, and complication rates were similar between groups (p?=?0.53).

Conclusions

Lateral parapatellar approach is a safe and effective surgical technique for performing TKA in moderately valgus knees. These equivalent early results are encouraging for systematic use of the lateral approach in moderately valgus knees.

     

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.     

Vastus medialis necrosis secondary to the combination of the subvastus and median parapatellar approaches for implantation of a total knee replacement

We describe a case where a subvastus approach was used for implantation of a primary total knee replacement, which subsequently became infected. Medial parapatellar approaches were then used for the revision surgery at weeks four and twelve after the primary procedure. Vastus medialis necrosis and lateral subluxation of the patella then followed. The patella was centralised electively by performing an open lateral release and semitendinosus tenodesis. This report therefore indicates that combining these two approaches over a short time interval set against a background of haematoma and infection can lead to ischaemic necrosis of the vastus medialis muscle and lateral subluxation of the patella.     

小切口股内侧与髌旁内侧入路行全膝置换术的比较研究

[目的]探讨经小切口股内侧肌入路行TKA的优点并与传统髌旁内侧入路的疗效进行比较.[方法]自2002年5月～2006年5月共收治行TKA56例60膝,其中采用小切口股内侧肌入路和传统髌旁内侧人路各28例30膝.分别对术后切口长度、疼痛度、引流出血量、手术前后Hb减少量、直腿抬高时间、术后住院天数、假体力线对位、术后6、12周、1年的活动度(ROM)及术后1年HSS评分进行比较分析.[结果]56例患者均获得随访,随访1～1.5年(平均13.2个月).两组除各有1例胫骨假体对位不良外,其余均获得准确的力线对位.微创组,平均切口11.3 cm,VAS评分平均2.76分,平均引流出血量96.8 ml、术后Hb平均减少25.5 g,直腿抬高平均3.8 d,术后平均住院8.6 d,术后6、12周的ROM分别为107°、117°;传统组,平均切口20.6 cm,VAS评分平均3.8分,平均引流出血量276.3 ml、术后Hb平均减少32.5 g,直腿抬高平均5.8 d,术后平均住院12.1 d,术后6、12周的ROM分别为98°、108°.以上各观察指标的手术疗效比较,经统计学分析显示差异有显著性意义(P＜0.01).微创组术后1年的ROM及HSS评分为121°和95分相对于传统组的118°和94分差异无显著性意义(P＞0.05).[结论]经微创中股入路行全膝置换术,术后膝关节功能恢复快,早期疗效满意.     

A comparison of the midvastus and paramedian approaches for total knee arthroplasty

This prospective, double-blinded evaluation of 24 osteoarthritic patients undergoing bilateral total knee replacement compared the midvastus and standard parapatellar approaches. The midvastus approach was found to offer an early advantage in terms of less pain and earlier return to function. There were no significant complications associated with the midvastus approach. This approach should be a part of the knee surgeon's armamentarium.