Better quadriceps recovery after minimally invasive total knee arthroplasty

Purpose

The proponents of minimally invasive total knee arthroplasty (TKA) have reported better functional recovery than conventional TKA. In most of the previous studies, the results were shown with the relatively subjective methods. We investigated the objective results with a dynamometry in this prospective randomized study. It was hypothesized that minimally invasive TKA would have a better and earlier recovery of quadriceps force in terms of the objective numeric data.

Methods

Sixty-six TKAs were prospectively randomized into two groups. Thirty-three knees underwent minimally invasive TKA using mini-midvastus approach and 33 knees underwent conventional TKA using medial parapatellar approach. The quadriceps force was assessed using a dynamometer. The data were collected preoperatively and at postoperative 6 weeks, 3 months, 6 months and 1 year consecutively.

Results

The mean of quadriceps force in minimally invasive TKA group at postoperative 6 weeks was greater than conventional TKA after removing the covariate (preoperative quadriceps force) with analysis of covariance (P = 0.002), but thereafter, the difference was not significant till 1 year. Meanwhile, with repeated measures analysis of variance, conventional TKA group had greater quadriceps recovery than minimally invasive TKA group during postoperative 6 weeks to 3 months (P = 0.035). The proportion of patients unable to recover the quadriceps force to their preoperative levels by 1 year postoperatively was similar in two groups.

Conclusion

Minimally invasive TKA has benefit in quadriceps recovery at earlier rehabilitation period although catch-up recovery in conventional TKA was accelerated from the postoperative 6 weeks to 3 months. It may support the concept of early return to full activity after minimally invasive TKA, and patients might get back early to normal life.

Level of evidence

Therapeutic study, Level I.     

Changes to patellar blood flow after minimally invasive total knee arthroplasty

Standard surgical exposure reduces blood flow to the patella during total knee arthroplasty (TKA). Reduction of patellar blood flow has resulted in patellofemoral complications including osteonecrosis and patellar fracture, necessitating revision surgery. In TKA, avoiding patellar eversion is one type of minimally invasive surgery (MIS) technique. This study is the first to measure patellar blood flow during MIS TKA with the knee in both extension and 90° of flexion followed by lateral retraction and then eversion of the patella. Patellar blood flow was measured using laser Doppler flowmetry in 40 patients during MIS TKA. A significant reduction in flow was noted when the leg was flexed from full extension to 90°. Eversion of the patella reduced patellar blood flow. MIS TKA without patellar eversion may be useful for preventing a reduction in patellar blood flow.     

Modular tibial plate for minimally invasive total knee arthroplasty

Purpose

Aim of the study was to evaluate the clinical and radiological results of a modular tibial plate purposely designed for minimally invasive total knee arthroplasty.

Methods

We prospectively assessed the results of 200 primary total knee replacements performed through a minimally invasive approach using a dedicated modular tibial plate, a posterior stabilized knee prosthesis, and a fixed bearing in 175 patients (139 women and 36 men), undergoing surgery between 2005 and 2009 presenting knee osteoarthritis. Median age at the time of surgery was 69?years (52–88).

Results

No patients were lost at follow-up. 3 implants underwent revision. At a mean 3?years (1–5?years) follow-up, the HHS and KSS score showed a significant improvement, increasing, respectively, from a median value of 35–95 (78–100) and from 31 points in the “knee” and 45 points in the “function” score to a median of 95 (83–100) and 94 (81–100). Using the Kaplan–Meier method, the survival rate at 5?years was 97.9% with a 95% confidence interval.

Conclusion

The implant showed good results in either clinical or radiological assessment at a short/midterm follow-up with a high survival rate.

Level of evidence

Therapeutic study, Level IV.     

Comparison of two minimally invasive implantation instrument-sets for total knee arthroplasty

Several choices of instrument systems are available for minimally invasive surgical approaches. There are reports that one alternative, the quadriceps sparing, side-cutting instrumentation, results in diminished implantation accuracy. A total of 108 patients were randomized to undergo TKA either using side-cutting implant instrumentation (Group A) or anterior–posterior mini-incision instrumentation (Group B). All TKAs were operated on with a minimal invasive, mini-midvastus surgical approach. 50% of the TKAs were performed with computer-assistance in each cohort. The radiographic parameters, clinical outcomes and knee scores were evaluated preoperatively and 3 months postoperative. In Group B, we found significantly higher accuracy for the mechanical axis of the limb (range ±3°: Group A 54% versus Group B 89%, p = <0.001), medial proximal tibial angle (range ±3°: Group A 85% versus Group B 98%, p = <0.027) and tibial slope (range ±3°: Group A 59% versus Group B 85%, p = <0.007). The application of the navigation system could only significantly reduce outliers (accuracy >3°) in Group B. Clinical outcomes and knee scores were similar in both groups and were not influenced by computer-assistance. Using the anterior–posterior, mini-incision instruments for minimally invasive TKA will lead to higher implantation accuracy when compared to the quadriceps sparing side-cutting instrumentation. The navigation technique could not compensate for shortcomings of the side-cutting instrumentation. The clinical relevance of this study is that the quadriceps sparing side-cutting instrumentation should not be used for TKA because of unacceptable reduced implantation accuracy.     

Physical activity after outpatient surgery and enhanced recovery for total knee arthroplasty

Purpose and hypothesis

The purpose of this study was to ‘objectively’ measure improvement of physical activity with the use of an activity monitor between patients who followed an enhanced recovery- or outpatient surgery pathway after total knee arthroplasty (TKA). It was hypothesized that both pathways will have comparable physical activity after TKA at 6-week follow-up.

Methods

This prospective observational comparative case study was designed to investigate activity parameters (e.g. physical activity, number of steps, sit–stand transfers) of two different pathways after 6 weeks with the use of a non-invasive triaxial accelerometer activity monitor. This study included 20 patients with a mean age of 65.5 years (SD 6.1) undergoing TKA who were allocated to follow one of the two pathways: enhanced recovery (n = 10) or outpatient surgery (n = 10). Patients were monitored for 4 days pre-, 4 days during and 4 days after 5 weeks postoperatively. Patient-reported outcome measures (PROMs) and range of knee motion were obtained pre- and 6 weeks postoperatively.

Results

The activity parameters recovered steeply during the first 4 postoperative days and continued to improve within both pathways (n.s.). Preoperative and during the first 4 days and 5 weeks postoperative, activity parameters were comparable (n.s.) between both pathways but did not reach preoperative levels of physical activity and range of motion (n.s.). PROMs improved within each pathway, and no difference between both pathways was observed (n.s.).

Conclusions

This study demonstrates that the early physical activity parameters of patients after TKA, following the outpatient surgery pathway, were similar to patients who followed the standard enhanced recovery pathway. The activity monitor is an added value for a more detailed and objective analysis of the physical performance in patients after TKA.

Level of evidence

III.

     

加速康复外科理念在膝关节置换术围术期应用

目的评价加速康复(ERAS)外科理念在膝关节置换术围术期的应用疗效。方法收集2015年1月至2016年1月收治的因膝关节骨性关节炎行膝关节置换术的82例患者,随机分为ERAS组(n=40)和常规组(n=42),比较两组围手术期疗效。结果患者82例随访1个月。所有患者切口均一期愈合,术后12 d拆线。ERAS组术中出血量、输血量均明显少于常规组,差异有统计学意义(P<0.05)。两组手术时间比较,差异无统计学意义(P>0.05)。ERAS组术后住院(8.0±3.4)d,明显低于常规组的(11.5±3.6)d,两组平均住院日比较,差异有统计学意义(P<0.05)。两组均未发生切口并发症。两组深静脉血栓、泌尿系统感染并发症发生率比较,差异无统计学意义(P>0.05)。比较术后12 d和术后1个月的膝关节KSS评分,ERAS组膝关节KSS评分优于常规组,差异有统计学意义(P<0.05)。结论 ERAS外科理论在膝关节置换围术期的应用能明显缩短术后住院时间和住院费用,可以促进患者膝关节功能的康复,值得推广和应用。     

The minimally invasive far medial subvastus approach for total knee arthroplasty in valgus knees

Purpose

The lateral approach in the valgus knee asks for a lot of soft tissue releases during the arthrotomy. The hypothesis of this study was that the far medial subvastus approach could be used in valgus knees and would guarantee both functional and radiological good to excellent results.

Methods

This is a retrospective study on 78 patients (84 knees) undergoing primary total knee arthroplasty (TKA) for type I or II fixed valgus knees. The mean (SD) preoperative mechanical alignment was 187° (4°) HKA angle. Functional recovery, pain, tourniquet times, necessary soft tissue releases as well as radiological alignment were measured.

Results

The Knee Score improved significantly from 45 (10) to 90 (10) (P < 0.05) and the function score improved as well from 35 (20) to 85 (10) (P < 0.05). Flexion improved from 110° (10°) to 137° (8°). Hospital stay was 4 (1.2) days. Alignment was corrected to 181° (1.5°) HKA angle with a postoperative joint line shift of +2.8 (3.2) mm. No clinical instability, as evaluated by the senior author, or osteolytic lines was observed at minimal one-year radiological follow-up.

Conclusion

The far medial subvastus approach is an excellent approach to perform Krackow type I and II TKA with primary PS implants.

Level of evidence

IV.     

Clinical and radiographic outcomes of minimally invasive total knee arthroplasty through a lateral approach

Purpose  

With increasing confidence and surgical experience, minimally invasive surgery (MIS) in total knee arthroplasty (TKA) is now being applied to more complicated cases. The present study assessed the feasibility of MIS-TKA using a lateral approach for valgus knees.     

Comparison of the minimally invasive and standard medial parapatellar approaches for primary total knee arthroplasty

Purpose

The minimally invasive surgical (MIS) approach has been popularised as an alternative to the standard medial parapatellar approach (MPP) in total knee arthroplasty (TKA). Advocates of this technique suggest earlier functional recovery due to less injury to the surrounding tissues. Potential disadvantages however may include reduced overall exposure, component malalignment and damage to neurovascular structures.

Methods

A systematic review and meta-analysis of randomised and quasi-randomised trials were conducted to compare the MIS and MPP approaches in primary TKA. Methodological features were rated independently by two reviewers.

Results

Seventeen studies were included involving 733 patients with mean age of 69 (SD ± 2.8) in the MIS group and 692 patients with mean age of 68.6 (SD ± 3.1) in the MPP group. Using a MIS approach led to significant increase in flexion within the first week after a TKA (mean difference (MD) of 9.9° (95% confidence interval (CI) 8.2–11.6, P < 0.01)). However, this effect was not sustainable at further follow-ups of ≥3 months. MIS showed a significantly increased risk of developing intraoperative complications with a risk ratio (RR) of 7.6 (95% CI 3.5–16.3, P < 0.01).

Conclusion

MIS results in superior function in the immediate postoperative period after a primary TKA but is also associated with increased rates of intraoperative complications, and therefore, a standard approach that allows adequate exposure and avoids tension to the wound edges would be more appropriate to prevent such complications.

Level of evidence

Therapeutic study, Level I.     

全膝关节置换术后的功能康复训练

目的介绍全膝关节置换术后的康复训练方法，总结其效果。方法对140例行全膝关节置换术的患者，进行1年系统的康复训练，按美国特种外科医院（HSS）膝关节功能评分标准，术前膝关节评分（51．25±6．10）分，康复内容包括：肌力、肌耐力、本体感受功能、活动度、理疗、心理治疗。通过功能评分、稳定性、肌力、满意度等几方面，评价其效果。结果术后3个月，膝关节肿胀已消除，术后平均1年患膝股四头肌、胭绳肌、腓肠肌肌力均达到Ⅳ级[徒手肌力评定（MMT）分级]以上，88．33％患者均能恢复正常步态和上下楼梯。患者主观满意程度高，术后12个月膝关节功能评分（87．13±7．43）分，与术前相比，差异有统计学意义（P〈0．01）。结论对于行全膝关节置换术后患者，采用该康复方法切实有效。     

Custom-fit minimally invasive total knee arthroplasty: effect on blood loss and early clinical outcomes

Purpose

Recently, new custom-fit pin guides in total knee arthroplasty (TKA) have been introduced. Use of these guides may reduce operating time. Use of the guides combined with the absence of intramedullary alignment jigs may lead to reduced blood loss and improved early outcomes. Our aim was to evaluate blood loss and early clinical outcomes in patients undergoing minimally invasive TKA using custom-fit magnetic resonance imaging (MRI)–based pin guides.

Methods

A prospective study in 80 patients was carried out. Patients were divided randomly into 2 equal groups. In one group, intramedullary alignment jigs were used. In the second group, custom-fit MRI-based pin guides were used. All patients received the same cemented posterior-stabilized implant through a mini-midvastus approach. The volume in the drain bottles was recorded after 48 h. Hb loss was estimated by subtracting the postoperative from the preoperative Hb level. Transfusion requirements and surgical time were recorded. Outcome measures were Knee Society Scores (KSS), knee flexion, knee swelling and pain.

Results

There was lower mean drainage of blood in the custom-fit group (391 ml vs. 603 ml; p < 0.0001). There was no difference in estimated loss of Hb (3.6 g/dl vs. 4.1 g/dl; n.s.) and in transfusion requirements (7.5 % vs. 10 %; n.s.). Surgical time was reduced in the custom-fit group (12 min less; p = 0.001). KSS measured at week 2, 6 and 12 showed no significant difference between groups. Knee flexion measured on days 7, 10 and at week 6, 12 and knee swelling and pain measured on days 1, 3, 10 and at week 6, 12 showed no significant difference between groups.

Conclusions

Using custom-fit pin guides reduces blood drainage, but not the estimated Hb loss in minimally invasive TKA and does not affect transfusion rate. Surgical time is reduced. There is no effect on the early clinical outcomes.

Level of evidence

Therapeutic study, Level I.     

Tennis after total knee arthroplasty

In this study, patients who played tennis after undergoing a total knee arthroplasty were analyzed in terms of their functional abilities and degree of satisfaction. The patients were recruited by means of a questionnaire that was sent to players from lists supplied by the United States Tennis Association. The study group consisted of 28 men and 5 women (46 total knee replacements) with a mean age of 64 years. Only 21% (7 of 33) of the patients' surgeons approved of their patients undertaking tennis activity, with 45% (15 of 33) recommending only doubles tennis. At both 1 year and a mean of 7 years after arthroplasty, players were playing both singles and doubles tennis approximately three times per week (range, one to seven). All tennis players polled were satisfied with their knee arthroplasties and their ability to resume playing tennis. Because the study patients played at a high level, future studies are needed to determine the effect of tennis on the general population, which does not play at such a uniformly high level. The long-term (15 to 20 years) effect of tennis activity on the clinical and radiologic outcome of total knee arthroplasty also needs to be determined.     

Computer-assisted surgery can reduce blood loss after total knee arthroplasty

The aim of this study was to compare blood loss and transfusion requirements in patients undergoing computer-assisted total knee arthroplasty (TKA) and patients operated with conventional instrumentation with intra-medullar guides. A prospective randomized study of 87 patients undergoing a TKA assigned to conventional technique (n = 44) or computer-assisted surgery (n = 43) was conducted. All patients were operated by the same surgeon and in all cases a cemented arthroplasty and deep recovery drainage were used. Both groups were comparable in all variables except for duration of ischemia, which was 13.7 min higher in the computer-assisted group. Blood loss due to drainage was higher in the conventional technique group (613 vs. 447 ml), as was the number of patients in which blood from the blood recovery system was reinfused (53 vs. 23%). Those patients undergoing computer-assisted surgery experienced less bleeding than those operated with the conventional technique. However, hemoglobin drop and allogenic transfusion rate were not statistically different in both groups.     

Free bone cement fragments after minimally invasive unicompartmental knee arthroplasty: an underappreciated problem

The minimally invasive implantation of unicompartmental knee arthroplasty (UKA) leads to excellent functional results, but due to the reduced intraoperative visibility the removal of excessive cement may be difficult. In a retrospective study we assessed radiologically the incidence of loose and excess bone cement in 120 UKAs and correlated it to the thickness of the tibial cement layer. In 25 cases loose or attached excess cement was seen. Two of these patients with loose cement bodies required revision surgery. An additional 2 patients not operated at our institution required revision because of pain and loss of motion. The average thickness of the tibial cement layer was 3.1 (1.7-5.0) mm in all the patients. But it was significantly higher in the group with excess cement bodies [3.3 (2.3-5.0) mm] compared to the group without excess cement [3.0 (1.7-4.1) mm] (P < 0.05). Symptomatic free cement bodies need to be removed immediately, if necessary arthroscopically, in order to avoid damage to the implants. To avoid this problem in minimally invasive UKA, intraoperative fluoroscopy, a dental mirror or a nerve hook seem to be useful tools to identify and remove loose or excess cement.     

帕瑞昔布钠对全膝全髋关节置换术后镇痛的疗效分析

目的 评价帕瑞昔布钠对全膝关节置换术(total knee arthroplasty,TKA)和全髋关节置换术(total hip arthroplasty,THA)术后的镇痛效果. 方法 本研究为前瞻性、随机、双盲研究,由同一组医师完成101例TKA患者和105例THA患者,根据镇痛方式分为三组:(1)术中静脉注射帕瑞昔布钠组;(2)术中关节局部注射帕瑞昔布钠组;(3)对照组.比较术后三组的视觉模拟疼痛评分(VAS)、关节活动度(ROM)、术后直腿抬高能力和恶心、呕吐等并发症的发生率. 结果 术中静脉注射帕瑞昔布钠组和术中关节局部注射帕瑞昔布钠组在术后各时段的VAS评分和术后24 h ROM及直腿抬高能力的差异无统计学意义(P＞0.05),但均明显优于对照组(P＜0.05).使用帕瑞昔布钠后恶心、呕吐等并发症的发生率没有显著增加. 结论 术中静脉注射和术中关节局部注射帕瑞昔布钠对TKA和THA术后的镇痛效果确切,有利于患者关节功能的迅速康复,且操作简便、实用,是TKA和THA镇痛的有效方法之一.     

Motion analysis after total knee arthroplasty

This study aimed to clarify the effect of gender and lateral dominance on grip muscle power. Subjects included healthy young males and females (15 men aged 22.1±0.7 years and 15 women aged 22.4±1.0 years) who were right-hand dominant. Grip muscle power (peak power) was measured in the dominant and non-dominant hands with six different loads ranging from 20% to 70% of maximum voluntary contraction (MVC). The grip muscle power was significantly larger in males than in females and in the dominant hand than in the non-dominant hand. In short, lateral dominance was confirmed. The grip muscle power values increased with increasing loads, and decreased after reaching a maximal value at about 50% MVC in both genders. In contrast, peak velocity decreased with increasing loads. The grip muscle power ratio of the dominant hand to the non-dominant hand was significantly larger in females in all loads. In conclusion, although grip muscle power is superior in males and in the dominant hand, the lateral dominance is more marked in females.