Patellar denervation with electrocautery in total knee arthroplasty without patellar resurfacing: a meta-analysis

Purpose

The impact of patellar denervation with electrocautery in total knee arthroplasty (TKA) on post-operative outcomes has been under debate. This study aims to conduct a meta-analysis and systematic review to compare the benefits and risks of circumpatellar electrocautery with those of non-electrocautery in primary TKAs.

Methods

Comparative and randomized clinical studies were identified by conducting an electronic search of articles dated up to September 2012 in PubMed, EMBASE, Scopus, and the Cochrane databases. Six studies that focus on a total of 849 knees were analysed. A random-effects model was conducted using the inverse-variance method for continuous variables and the Mantel–Haenszel method for dichotomous variables.

Results

There was no significant difference in the incidence of anterior knee pain between the electrocautery and non-electrocautery groups. In term of patellar score and Knee Society Score, circumpatellar electrocautery improved clinical outcomes compared with non-electrocautery in TKAs. The statistical differences were in favour of the electrocautery group but have minimal clinical significance. In addition, the overall complications indicate no statistical significance between the two groups.

Conclusions

This study shows no strong evidence either for or against electrocautery compared with non-electrocautery in TKAs.

Level of evidence

Therapeutic study (systematic review and meta-analysis), Level III.     

Secondary patellar resurfacing in the treatment of patellofemoral pain after total knee arthroplasty

Purpose  

This paper reports a prospective review of patients who, between 2004 and 2007, underwent secondary patellar resurfacing (SPR) due to anterior knee pain after a primary total knee arthroplasty (TKA). The aim was to evaluate the clinical outcomes obtained with the SPR and to compare them with radiological findings.     

Total knee arthroplasty without patellar resurfacing in active and overweight patients

Overweight patients are often considered poor candidates for total knee arthroplasty (TKA). A retrospective study of this was done on 47 osteoarthritic knees treated by TKA without patella resurfacing between March 1991 and June 1993. The Hospital for Special Surgery (HSS) rating system was used for clinical evaluation, and radiographs to study the degree of osteoarthritis and radiolucency. Correlations between overweight, range of motion (ROM) and stage of patellar damage and other measured variables (HSS score, patellar pain and radiolucency) were studied. Overweight was not correlated with HSS score, radiolucency or patellar pain. ROM was significantly correlated with patellar pain and HSS score, with better results in patients with ROM between 90° and 110°. Therefore, we believe that TKA in osteoarthritic knees can lead to successful results, even in active or overweight patients. Received: 19 November 1996 Accepted: 7 April 1997     

全膝关节置换术中髌骨置换对骨性关节炎患者早期疗效及膝前痛的影响

目的：探讨全膝关节置换术中是否进行髌骨置换对骨性关节炎患者的临床疗效及术后疼痛的影响。方法笔者采用随机数字表法将骨科2011年5月～2013年7月收治的93例行人工全膝关节置换术患者分为髌骨置换组43例和未置换组50例,比较两组患者治疗前与治疗后不同时间的相关指标变化差异。结果术前髌骨置换组与非置换组的膝关节KSS（美国膝关节协会）评分、Feller评分差异不显著（ P＞0．05）;术后第3、6、12个月髌骨置换组膝关节KSS评分、Feller评分显著高于非置换组（P＜0．05）;术前髌骨置换组与非置换组的膝关节视觉模拟评分（VAS）差异不显著（P＞0．05）;术后第3、6、12个月髌骨置换组膝关节VAS评分显著低于非置换组（P＜0．05）;两组患者术前、术后的胫股角,髌韧带比值,关节活动度ROM屈、伸值在两组间比较差异均不显著（ P＞0．05）;术后第12个月两组患者的胫股角、髌韧带比值,关节活动度ROM屈、伸值较治疗前均显著好转（ P＜0．05）。结论全膝关节置换术中进行髌骨置换对改善膝关节功能评分、髌骨评分、术后疼痛评分均有显著的效果。     

The effect of total synovectomy in total knee arthroplasty: a prospective randomized controlled study

Purpose  

The apparent synovial hypertrophy in some cases of noninflammatory knee osteoarthritis suggests that total synovectomy may provide beneficial inflammatory and pain relief after total knee arthroplasty. The aim of the study was to compare the effect of synovectomy on the postoperative pain, bleeding and functional outcome after surgical treatment of knee osteoarthritis.     

Comparison of patellar retention versus resurfacing in LCS mobile-bearing total knee arthroplasty

Purpose  

The aim of this retrospective study was to compare clinical outcomes of total knee arthroplasty (TKA) with and without patellar resurfacing using the Low Contact Stress (LCS) mobile-bearing prosthesis in 275 osteoarthritic knees (199 patients) after a minimum of 7 years of follow-up.     

Tibio-femoral and patello-femoral joint kinematics during navigated total knee arthroplasty with patellar resurfacing

Purpose

In total knee arthroplasty, surgical navigation systems provide tibio-femoral joint (TFJ) tracking for relevant bone preparation, disregarding the patello-femoral joint (PFJ). Therefore, the important intra-operative assessment of the effect of component positioning, including the patella, on the kinematics of these two joints is not available. The objective of this study is to explore in vivo whether accurate tracking of the patella can result in a more physiological TFJ and PFJ kinematics during surgery.

Methods

Ten patients underwent navigated knee replacement with patellar resurfacing. A secondary system was used to track patellar motion and PFJ kinematics using a special tracker. Patellar resection plane position and orientation were recorded using an instrumented probe. During all surgical steps, PFJ kinematics was measured in addition to TFJ kinematics.

Results

Abnormal PFJ motion patterns were observed pre-operatively at the impaired knee. Patellar resection plane orientation on sagittal and transverse planes of 3.9° ± 9.0° and 0.4° ± 4.1° was found. A good restoration of both TFJ and PFJ kinematics was observed in all replaced knees after resurfacing, in particular the rotations in the three anatomical planes and medio-lateral patellar translation.

Conclusions

Patella tracking results in nearly physiological TFJ and PFJ kinematics in navigated knee arthroplasty with resurfacing. The intra-operative availability also of PFJ kinematics can support the positioning not only of the patellar component in case of resurfacing, but also of femoral and tibial components.

Level of evidence

II.     

Simultaneous bilateral total knee arthroplasty with robotic and conventional techniques: a prospective, randomized study

Purpose  

The authors performed this study to compare the outcomes of robotic-assisted and conventional TKA in same patient simultaneously. It was hypothesized that the robotic-assisted procedure would produce better leg alignment and component orientation, and thus, improve patient satisfaction and clinical and radiological outcomes.     

Asymmetrical total knee arthroplasty does not improve patella tracking: a study without patella resurfacing

It is often suggested that patella tracking after total knee arthroplasty (TKA) with an asymmetrical patella groove is more physiological than with a symmetrical patella groove. Therefore, this study tried to address two questions: what is the effect of TKA on patella tracking, and is patella tracking after asymmetrical TKA more physiological than patella tracking after symmetrical TKA? The patellar and tibial kinematics of five cadaveric knee specimens were measured in the intact situation, after the incision and suturing of a zipper, and after placement of a symmetrical TKA and an asymmetrical TKA, respectively. The patellae were not resurfaced. The flexion-extension kinematics were measured with an internal and external tibial moment to determine the envelope of motion (laxity bandwidth) of the tibio-femoral and patello-femoral articulation. The kinematics after TKA showed statistically significant changes in comparison to the intact situation: patellar medio-lateral translation, patellar tilt and tibial rotation were significantly affected. No statistically significant differences in knee kinematics were found between the symmetrical and the asymmetrical TKAs. We conclude that conventional TKA significantly changes physiological patello-femoral kinematics, and TKA with an asymmetrical patella groove does not improve the non-physiological tracking of the patella.     

Patellar morphology and femoral component geometry influence patellofemoral contact stress in total knee arthroplasty without patellar resurfacing

Purpose

The objective of this study was to determine the effect of patellar morphology and implant design on patellofemoral contact stress in total knee arthroplasty (TKA) without patellar resurfacing.

Methods

Radiographic investigation: One hundred and fifty-seven knees of 127 patients were included in the study. Implants used in the present series were Low Contact Stress (LCS), Genesis II and NexGen. The relationship between the pre-operative patellar facet angle and newly identified post-operative osteosclerosis was assessed. Finite element analysis: Using patient-specific patellar three-dimensional finite element models, the relationship between the patellar facet angle and mean von Mises stress within the patella was calculated at flexion angles of 15°, 45°, 75° and 105°.

Results

Radiographic investigation: Post-operative osteosclerosis was observed with decreasing patellar facet angle in the Genesis II (odds ratio?=?0.72; 95% confidence interval, 0.55–0.93; P?=?0.012) and NexGen implants (odds ratio?=?0.87; 95% confidence interval, 0.77–0.99; P?=?0.029). Patients treated with the Genesis II had significantly more advanced osteosclerosis than those treated with the other two implants. Finite element analysis: A negative correlation was found between the patellar facet angle and the mean von Mises stress for all three implants. The Genesis II showed significantly higher von Mises stress than the other two implants at flexion angles of 15°, 45° and 105°.

Conclusions

Both patellar morphology and femoral component geometry influence patellofemoral contact stress in total knee arthroplasty without patellar resurfacing.

Level of evidence

Case control study, Level III.     

PSI kinematic versus non-PSI mechanical alignment in total knee arthroplasty: a prospective,randomized study

Purpose

Kinematic alignment in TKA is supposed to restore function by aligning the components to the premorbid flexion–extension axis instead of altering the joint line and natural kinematic axes of the knee. The purpose of this study was to compare mechanically aligned TKA to kinematic alignment.

Methods

In this study, 200 patients underwent TKA and were randomly assigned to 2 groups: 100 TKAs were performed using kinematic alignment with custom-made cutting guides in order to complete cruciate-retaining TKA; the other 100 patients underwent TKA that was manually performed using mechanical alignment. The WOMAC and combined Knee Society Score (KSS), as well as radiological alignment, were determined as outcome parameters at the 12-month endpoint.

Results

WOMAC and KSS significantly improved in both groups. There was a significant difference in both scores between groups in favour of kinematic alignment. Although the kinematic alignment group demonstrated significantly better overall results, more outliers with poor outcomes were also seen in this group. A correlation between post-operative alignment deviation from the initial plan and poor outcomes was also noted. The most important finding of this study is that applying kinematic alignment in TKA achieves comparable results to mechanical alignment in TKA. This study also shows that restoring the premorbid flexion–extension axis of the knee joint leads to better overall functional results.

Conclusion

Kinematic alignment is a favourable technique for TKA.

Clinical relevance

The kinematic alignment idea might be a considerable alternative to mechanical alignment in the future.

Level of evidence

II.

     

Patellar resurfacing versus patellar retention in primary total knee arthroplasty: a systematic review of overlapping meta-analyses

Purpose

The need of patellar resurfacing in total knee arthroplasty (TKA) is a subject of debate. This systematic review of overlapping meta-analyses aimed to assess and analyze current evidence regarding patellar resurfacing and non-resurfacing in TKA.

Methods

A systematic literature search was performed in March 2017 in PubMed, CINAHL and Cochrane Library. Inclusion criteria were meta-analysis of randomized controlled trials that compared TKA with and without patellar resurfacing considering as outcomes re-operations rate, complications, anterior knee pain, functional scores. The quality of meta-analyses was evaluated with AMSTAR score and the most relevant meta-analysis was determined by applying the Jadad algorithm.

Results

Ten meta-analyses, published between 2005 and 2015, were included in the systematic review. Two studies found a significantly increased Knee Society Score in the resurfacing group. According to four meta-analyses, anterior knee pain incidence was lower in resurfacing group. Six of the included studies described a greater risk of re-intervention in the non-resurfacing groups. The overall quality of included studies was moderate. The most relevant meta-analysis reported no differences in functional scores and incidence of anterior knee pain between the groups.

Conclusions

Comparable outcomes were found when comparing patellar resurfacing and non-resurfacing in TKA. The higher risk of re-operations after non-resurfacing should be interpreted with caution due to the methodological limitations of the meta-analyses regarding search criteria, heterogeneity and the inherent bias of easier indication to reoperation when the patella is not resurfaced. There is no clear superiority of patellar resurfacing compared to patellar retention.

Level of evidence

Level II, systematic review of meta-analyses.

     

Effect of surgical closing in total knee arthroplasty at flexion or extension: a prospective,randomized study

Purpose

The aim of this study was to evaluate the effect of knee position during wound closure (flexed vs. extended) in total knee arthroplasty on knee strength and function, as determined by knee society scores and isokinetic testing of extensor and flexor muscle groups.

Methods

In a prospective, randomized, double-blind trial, 29 patients were divided in two groups: for Group 1 patients, surgical closing was performed with the knee extended, and for Group 2 patients, the knee flexed at 90°. All the patients were treated with the same anaesthesia method, surgical team, surgical technique, prosthesis type, and rehabilitation process. American Knee Society Score values and knee flexion degrees were recorded. Isokinetic muscle strength measurements of both knees in flexion and extension were taken using 60° and 180°/s angular velocity. The peak torque and total work values, isokinetic muscle strength differences, and total work difference values were calculated for surgically repaired and healthy knees.

Results

No significant difference in the mean American Knee Society Score values and knee flexion degrees was observed between the two groups. However, using isokinetic evaluation, a significant difference was found in the isokinetic muscle strength differences and total work difference of the flexor muscle between the two groups when patients were tested at 180°/s. Less loss of strength was detected in the isokinetic muscle strength differences of the flexor muscle in Group 2 (?4.2 %) than in Group 1 (?23.1 %).

Conclusion

For patients undergoing total knee arthroplasty, post-operative flexor muscle strength is improved if the knee is flexed during wound closure.

Level of evidence

II.     

Patellar resurfacing in total knee arthroplasty for osteoarthritis: a meta-analysis

Purpose  

Whether to resurface the patella during a primary total knee arthroplasty remains a controversial issue. The aim of this study was to determine the advantages and disadvantages of patellar resurfacing during total knee arthroplasty for osteoarthritis through an evaluation of the current literature.     

Avoidance of patellar eversion improves range of motion after total knee replacement: a prospective randomized study

Minimally invasive surgery has recently been introduced in TKA surgery. The purpose of this study was to evaluate the effect of eversion of the patella, on safety and functional result after TKA. In a prospective, randomised, double blinded trial, 60 patients were divided in two groups: group A underwent TKA through a standard medial parapatellar arthrotomy, with patellar eversion. Group B underwent the same exposure, except for the fact that the patella was subluxed laterally. All other treatment protocols were identical. Outcomes were measured until 1 year postoperatively. Radiographic evaluation included AP, lateral, skyline and full leg standing radiographs. VAS, WOMAC score, Knee Society Knee and Function score were performed. Active and passive range of motion (ROM) and knee proprioception was measured. All patients underwent isokinetic strength testing. The mean passive ROM changed from 121° preoperatively to 121° postoperatively in group A, compared to 118°–131° respectively in group B at 1 year (P = 0.003). The mean active ROM changed from 112° to 115° in group A, and from 108° to 125° in group B (P = 0.005). All other parameters were not significantly different. Patellar dislocation without eversion for exposing the knee during TKA is a safe procedure and improves ROM at 1 year postoperatively.     

Effect of preoperative deformity on postoperative leg axis in total knee arthroplasty: a prospective randomized study

Computer-assisted surgery-total knee arthroplasty (CAS-TKA) has been suggested to afford greater precision than conventional TKA; however, it is unclear whether this is influenced by preoperative angular deformity. This prospective study was conducted to determine the effect of preoperative angular deformity on the postoperative mechanical axis. Sixty patients underwent stage bilateral TKA; CAS-TKA was performed on one side and conventional TKA on the other side. It was demonstrated that severity of preoperative angular deformity affected the resulting alignment in conventional TKA, but not in CAS-TKA. The mechanical axis of the leg was within 3° of the planned axis in 83% of CAS-TKA but only 32% of conventional TKA cases when the preoperative angular deformity was >12° (P < 0.01). When the preoperative angular deformity was <12°, the mechanical axis of the leg was within 3° of the planned axis in 90% of CAS-TKA but only 69% of conventional TKA (P < 0.025). This study thus concluded that the resulting alignment in conventional TKA is influenced by large preoperative angular deformity. Consistent results in alignment can be achieved with CAS-TKA, though preoperative angular deformity still played a role in predicting the postoperative mechanical axis. CAS-TKA achieves better postoperative alignment than conventional TKA in both severe and mild preoperative angular deformity.     

An alternative patellar resurfacing technique in knee replacement: patellofemoral fascial interposition arthroplasty

The present study reports the early clinical results of 38 osteoarthritic patients (38 knees) who were treated by total knee replacement in conjunction with patellofemoral fascial interposition arthroplasty (PFIA). After the femoral and tibial components were inserted, a fasciotendinous graft was harvested from the anterior surface of the quadriceps tendon and sutured around the articular surface of the patella. The patients were followed-up for a minimum of 24 months. The durability of the fascial graft was assessed radiographically by addition of a wire suture marker placed into the fascia in the first five patients. Patients were evaluated using the Hospital for Special Surgery (HSS) knee-rating system, and anterior knee pain was assessed using specific patellofemoral-related questions. The average HSS knee score improved from 61 points preoperatively to 92 points at 24 months' follow-up (P<0.001). Twenty-five patients (65.7%) had anterior knee pain preoperatively, and seven patients (18.4%) revealed anterior knee pain at their last visits (P<0.001). The position of the markers in the fascial grafts did not show any change during radiological follow-ups. Our data suggest that, PFIA provides good pain relief and it may be an alternative resurfacing technique avoiding the complications of patellar components.