Knee Surg Sports Traumatol Arthrosc DOI 10.1007/s00167-014-3311-z
KNEE
Patellofemoral resurfacing and patellar denervation in primary total knee arthroplasty Alisara Arirachakaran · Chanchit Sangkaew · Jatupon Kongtharvonskul
Received: 10 January 2014 / Accepted: 3 September 2014 © European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA) 2014
Abstract Purpose To conduct a systematic review and network meta-analysis of randomized controlled trials (RCTs) with the aim of comparing relevant clinical outcomes between patellar denervation, resurfacing and non-resurfacing. Methods A database search was performed using PubMed and Scopus search engines. RCTs or quasi-experimental designs comparing clinical outcomes between treatments by a search of articles dated from inception to October 23, 2012. Unstandardized mean difference (UMD) and random effects methods were applied for pooling continuous and dichotomous outcomes, respectively. A longitudinal mixed regression model was used for network meta-analysis to indirectly compare treatment effects. Results Eighteen of 315 studies identified were eligible. Compared with patellar non-resurfacing, patellar denervation had a UMD that displayed a significant improvement in symptoms with values in pain visual analog score (VAS) and Knee Society Score (KSS) of −0.6 [95 % confidence interval (CI) −1.13, −0.25] and 2.55 (95 % CI 0.43, 4.68), respectively. The UMD in VAS, KSS, and Knee Function Score (KFS) in patellar resurfacing showed no significant improvement in symptoms when compared to nonresurfacing. Patients who underwent surgery with patellar
resurfacing had a lower reoperation rates with pooled relative risks (RRs) of 0.69 (95 % CI 0.50, 0.94) when compared to non-resurfacing. The network meta-analysis suggested a benefit of borderline significance for patellar denervation with a pooled RR of 0.63 (95 % CI 0.38, 1.03), showing that there is a lower chance of anterior knee pain when compared to non-resurfacing. Patellar resurfacing also displays a significantly lower chance of reoperation with a pooled RR of 0.68 (95 % CI 0.50, 0.92) when compared to non-resurfacing. Multiple active treatment comparisons indicated that patellar denervation resulted in greater improvement in KFS than patellar resurfacing. Conclusion This review suggests that either patellar denervation or patellar resurfacing may be selected for the management of the patellofemoral component in total knee replacement. Patellar denervation may help improve postoperative knee function, but does not improve pain when compared to patellar resurfacing. Keywords Circumferential electrocautery · Patellar denervation · Resurfacing · Non-resurfacing · Network meta-analysis
Introduction A. Arirachakaran · C. Sangkaew Orthopedics Department, Police General Hospital, Bangkok, Thailand e-mail: [email protected] C. Sangkaew e-mail: [email protected] J. Kongtharvonskul (*) Section for Clinical Epidemiology and Biostatistics, Faculty of Medicine Ramathibodi Hospital, Bangkok, Thailand e-mail: [email protected]
In patients with osteoarthritis of the knee (OA), treatment with total knee replacement (TKR) has been reported to be as high as 49 % [35]. Complications related to the patella such as postoperative anterior knee pain, subluxation, dislocation, patella fracture, rupture of the quadriceps tendon or the patellar ligament and patella clunk occur at a range of 4–50 % [13, 17, 29, 34]. The controversial indications for resurfacing have included obesity, preoperative anterior knee pain, moderate or severe chondromalacia, abnormal
13
patellar tilt, inflammatory arthritis, and a high patellar height. Some surgeons prefer selective resurfacing of the patella for patients with osteoarthritis [38, 39, 41], while others find more predictable results with routine patellar resurfacing [13, 37, 38, 43]. However, patellar resurfacing has potential risk of patellar fracture and prosthetic revision in the future [21, 47, 48]. Other options include patellar reshaping, lateral facetectomy [24], and patellar denervation [1, 4, 24, 45]. Partial lateral facetectomy of the patella has been proposed as a relatively simple and effective method to treat isolated patellofemoral (PF) osteoarthritis and to reduce anterior knee pain [26, 28, 49], as is denervation by circumferential electrocautery, which reduces the level of efferent pain signals, reducing the severity and incidence of anterior knee pain. Patella retention (non-resurfacing) is practiced due to its benefits of conserving patellar bone stock, reducing operative time and avoiding complications associated with resurfacing [3, 8, 20, 21, 36]. However, some authors report that a non-resurfaced patella may be associated with a higher rate of anterior knee pain [4]. Three systematic reviews recently published [15, 18, 22] show that patellar resurfacing can reduce the need for reoperation. However, when compared to total knee arthroplasty without patellar resurfacing, there is no distinct improvement in postoperative knee function or patient satisfaction. Whether it decreases the incidence of anterior knee pain remains uncertain [15, 18, 22]. There are a few randomized controlled trials (RCT) [1, 4, 24, 45] of patellar denervation, resurfacing [24], and non-resurfacing [1, 4, 45] of the patella in primary TKR with high methodological quality. However, no consistent results have been provided in published randomized trials. There are no RCTs, systematic reviews, or meta-analyses that directly compared clinical efficacy and adverse events of patellar resurfacing with patellar denervation. Therefore, we have conducted a systematic review with a network meta-analysis of RCTs with medium-term follow-up with the aim of comparing relevant clinical outcomes, which include postoperative anterior knee pain, American Knee Society Score that consists of two parts: the Knee Score (KS) and Function Score (FS), Western Ontario and McMaster Universities Osteoarthritis Index Score (WOMAC), Bristol Knee Score (BKS), and reoperation rates between patellar resurfacing, patellar denervation, and patellar non-resurfacing.
Knee Surg Sports Traumatol Arthrosc
Systematic Reviews and Meta-Analyses (PRISMA) guideline [19]. The Medline and Scopus databases were used to identify relevant studies published in English from the date of inception to October 23, 2012. The PubMed and Scopus search engines were used to locate studies using the following search terms: (clinical trial OR RCT OR randomized controlled trial) AND [(patellar resurfacing) OR (patellar denervation) OR (patella non-resurfacing)] AND (total knee arthroplasty) AND [(anterior knee pain) OR (AKP) OR (KSS) OR (Knee Society Score) OR (Knee Function Score) OR (WOMAC score) OR (reoperation) OR (Bristol score) OR (PF problem)]. Search strategies for Medline and Scopus are described in the appendix. Relevant studies from the reference lists of identified studies and previous systematic reviews were also explored. Selection of studies Identified studies were selected by one author (J.K.) and randomly checked by (A.A.). The titles and abstracts were initially screened, and full papers were retrieved if a decision could not be made from the abstracts. The reasons for ineligibility or exclusion of studies were recorded (Fig. 1). Inclusion criteria Randomized controlled trials or quasi-experimental designs that compared clinical outcomes between patellar resurfacing and patellar denervation with patellar reshaping in primary TKR were eligible if the following criteria were fulfilled: • Compared clinical outcomes between patellar resurfacing or patellar denervation (with or without reshaping) with non-resurfacing. • Compared at least one of following outcomes: Visual Analog Score (VAS), Knee Society Knee Score (KS) and Function Score (FS), WOMAC score, Bristol Knee Score, anterior knee pain, postoperative infection, patella fracture, PF problems, and reoperation rates. • Had sufficient data to extract and pool, i.e., the reported mean, standard deviation (SD), the number of subjects according to treatments for continuous outcomes, and the number of patients according to treatment for dichotomous outcomes. Data extraction
Materials and methods Search strategy A systematic review and network meta-analysis were performed in accordance with Preferred Reporting Items for
13
Two reviewers (J.K. and A.A.) independently performed data extraction using standardized data extraction forms. General characteristics of the study [e.g., mean age, gender, body mass index (BMI), mean follow-up time, pain score (VAS), and functional scores (KS, FS) at baseline] were
Knee Surg Sports Traumatol Arthrosc 36 studies retrieved from Medline
304 studies retrieved from Scopus 315 left after removed duplicates
299 studies were ineligible:
16 studies left for reviewing full paper
2 studies from Hand searching from reference list
•
293 non-RCTs
•
no outcomes of interest
•
1 no interventions
•
5 non English
18 studies left for full paper
3 studies of denervation of patella left for review
15 studies of patella resurfacing left for review
Visual analog score Denervation vs non-resurfacing: 2 study Resurfacing vs non-resurfacing: 3 study
Knee score Denervation vs non-resurfacing: 2 Resurfacing vs non-resurfacing: 11
Function score Denervation vs non-resurfacing: 2 study Resurfacing vs non-resurfacing: 7 study
Anterior knee pain Denervation vs non-resurfacing: 1 study Resurfacing vs non-resurfacing: 4 studies
Patella problem Resurfacing vs non-resurfacing: 8 study
Patella fracture Denervation vs non-resurfacing: 3 study Resurfacing vs non-resurfacing: 11 study
Infection Denervation vs non-resurfacing: 3 study Resurfacing vs non-resurfacing: 12 studies
Reoperation due to patella Denervation vs non-resurfacing: 3 study Resurfacing vs non-resurfacing: 14 study
Fig. 1 Flow of study selection
extracted. The number of subjects, mean, and SD of continuous outcomes [i.e., pain by VAS, KS, and FS] between groups were extracted. Cross-tabulated frequencies between treatment and all dichotomous outcomes (anterior
knee pain, infection, patella fracture, PF problems, and reoperation due to patella problems) were also extracted. Any disagreements were resolved by discussion and consensus with a third party (C.S.).
13
Risk of bias assessment Two authors (J.K. and A.A.) independently assessed risk of bias for each study. Six study quality domains were considered, consisting of sequence generation, allocation concealment, blinding (participant, personnel, and outcome assessors), incomplete outcome data, selective outcome reporting, and other sources of bias [23]. Disagreements between two authors were resolved by consensus and discussion with a third party (C.S.). Outcomes The outcomes of interest were pain VAS, Knee Society Knee Score, Knee Society Functional Score, anterior knee pain, infection, patella fracture, PF problems, and reoperation due to patella problems. Methods of measure for these outcomes were used according to the original studies. Briefly, this includes the VAS pain scale (0–10), KS that consists of pain (0–50), range of motion (0–25), stability (0–25) with total scores ranging from 0 to 100, and FS that consists of walking distance (0–50), and stair climbing (0–50) with a total score ranging from 0 to 100. Postoperative complications (anterior knee pain, infection, patella fracture, PF problems, and reoperation due to patella problems) were considered. Statistical analysis Direct comparisons of continuous outcomes measured at the end of each study between patellar resurfacing versus non-resurfacing and patellar denervation versus non-resurfacing were pooled using an unstandardized mean difference (UMD). Heterogeneity of the mean difference across studies was checked using the Q-statistic, and the degree of heterogeneity was quantified using the I2 statistic. If heterogeneity was present as determined by a statistically significant Q-statistic or by I2 >25 %, the UMD was estimated using a random effects model; otherwise, a fixed effects model was applied. For dichotomous outcomes, a relative risk (RR) of postoperative complication of treatment comparisons at the end of each study was estimated and pooled. Heterogeneity was assessed using the previous method. If heterogeneity was present, the Dersimonian and Laird method [2] was applied for pooling. If not, the fixed effects model by inverse variance method was applied. Meta-regression was applied to explore the source of heterogeneity (e.g., mean age, percentage of females, BMI, and follow-up time) if data were available. Publication bias was assessed using contourenhanced funnel plots [32, 33] and Egger tests [12]. For indirect comparisons, network meta-analyses were applied to assess all possible effects of treatment if summary data were available for pooling [25, 42, 44]. A linear
13
Knee Surg Sports Traumatol Arthrosc
regression model, weighted by inverse variance, was applied to assess the treatment effects for continuous outcomes. For postoperative complications, a mixed-effect Poisson regression was applied to assess treatment effects [25]. Summary data were expanded to individual patient data using the “expand” command in STATA. Treatment was considered as a fixed-effect, whereas the study variable was considered as a random-effect in a mixed-effect model. The pooled RR and its 95 % confidence intervals (CIs) were estimated by exponential coefficients of treatments. All analyses were performed using STATA version 12.0 [44]. A P value
KNEE
Patellofemoral resurfacing and patellar denervation in primary total knee arthroplasty Alisara Arirachakaran · Chanchit Sangkaew · Jatupon Kongtharvonskul
Received: 10 January 2014 / Accepted: 3 September 2014 © European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA) 2014
Abstract Purpose To conduct a systematic review and network meta-analysis of randomized controlled trials (RCTs) with the aim of comparing relevant clinical outcomes between patellar denervation, resurfacing and non-resurfacing. Methods A database search was performed using PubMed and Scopus search engines. RCTs or quasi-experimental designs comparing clinical outcomes between treatments by a search of articles dated from inception to October 23, 2012. Unstandardized mean difference (UMD) and random effects methods were applied for pooling continuous and dichotomous outcomes, respectively. A longitudinal mixed regression model was used for network meta-analysis to indirectly compare treatment effects. Results Eighteen of 315 studies identified were eligible. Compared with patellar non-resurfacing, patellar denervation had a UMD that displayed a significant improvement in symptoms with values in pain visual analog score (VAS) and Knee Society Score (KSS) of −0.6 [95 % confidence interval (CI) −1.13, −0.25] and 2.55 (95 % CI 0.43, 4.68), respectively. The UMD in VAS, KSS, and Knee Function Score (KFS) in patellar resurfacing showed no significant improvement in symptoms when compared to nonresurfacing. Patients who underwent surgery with patellar
resurfacing had a lower reoperation rates with pooled relative risks (RRs) of 0.69 (95 % CI 0.50, 0.94) when compared to non-resurfacing. The network meta-analysis suggested a benefit of borderline significance for patellar denervation with a pooled RR of 0.63 (95 % CI 0.38, 1.03), showing that there is a lower chance of anterior knee pain when compared to non-resurfacing. Patellar resurfacing also displays a significantly lower chance of reoperation with a pooled RR of 0.68 (95 % CI 0.50, 0.92) when compared to non-resurfacing. Multiple active treatment comparisons indicated that patellar denervation resulted in greater improvement in KFS than patellar resurfacing. Conclusion This review suggests that either patellar denervation or patellar resurfacing may be selected for the management of the patellofemoral component in total knee replacement. Patellar denervation may help improve postoperative knee function, but does not improve pain when compared to patellar resurfacing. Keywords Circumferential electrocautery · Patellar denervation · Resurfacing · Non-resurfacing · Network meta-analysis
Introduction A. Arirachakaran · C. Sangkaew Orthopedics Department, Police General Hospital, Bangkok, Thailand e-mail: [email protected] C. Sangkaew e-mail: [email protected] J. Kongtharvonskul (*) Section for Clinical Epidemiology and Biostatistics, Faculty of Medicine Ramathibodi Hospital, Bangkok, Thailand e-mail: [email protected]
In patients with osteoarthritis of the knee (OA), treatment with total knee replacement (TKR) has been reported to be as high as 49 % [35]. Complications related to the patella such as postoperative anterior knee pain, subluxation, dislocation, patella fracture, rupture of the quadriceps tendon or the patellar ligament and patella clunk occur at a range of 4–50 % [13, 17, 29, 34]. The controversial indications for resurfacing have included obesity, preoperative anterior knee pain, moderate or severe chondromalacia, abnormal
13
patellar tilt, inflammatory arthritis, and a high patellar height. Some surgeons prefer selective resurfacing of the patella for patients with osteoarthritis [38, 39, 41], while others find more predictable results with routine patellar resurfacing [13, 37, 38, 43]. However, patellar resurfacing has potential risk of patellar fracture and prosthetic revision in the future [21, 47, 48]. Other options include patellar reshaping, lateral facetectomy [24], and patellar denervation [1, 4, 24, 45]. Partial lateral facetectomy of the patella has been proposed as a relatively simple and effective method to treat isolated patellofemoral (PF) osteoarthritis and to reduce anterior knee pain [26, 28, 49], as is denervation by circumferential electrocautery, which reduces the level of efferent pain signals, reducing the severity and incidence of anterior knee pain. Patella retention (non-resurfacing) is practiced due to its benefits of conserving patellar bone stock, reducing operative time and avoiding complications associated with resurfacing [3, 8, 20, 21, 36]. However, some authors report that a non-resurfaced patella may be associated with a higher rate of anterior knee pain [4]. Three systematic reviews recently published [15, 18, 22] show that patellar resurfacing can reduce the need for reoperation. However, when compared to total knee arthroplasty without patellar resurfacing, there is no distinct improvement in postoperative knee function or patient satisfaction. Whether it decreases the incidence of anterior knee pain remains uncertain [15, 18, 22]. There are a few randomized controlled trials (RCT) [1, 4, 24, 45] of patellar denervation, resurfacing [24], and non-resurfacing [1, 4, 45] of the patella in primary TKR with high methodological quality. However, no consistent results have been provided in published randomized trials. There are no RCTs, systematic reviews, or meta-analyses that directly compared clinical efficacy and adverse events of patellar resurfacing with patellar denervation. Therefore, we have conducted a systematic review with a network meta-analysis of RCTs with medium-term follow-up with the aim of comparing relevant clinical outcomes, which include postoperative anterior knee pain, American Knee Society Score that consists of two parts: the Knee Score (KS) and Function Score (FS), Western Ontario and McMaster Universities Osteoarthritis Index Score (WOMAC), Bristol Knee Score (BKS), and reoperation rates between patellar resurfacing, patellar denervation, and patellar non-resurfacing.
Knee Surg Sports Traumatol Arthrosc
Systematic Reviews and Meta-Analyses (PRISMA) guideline [19]. The Medline and Scopus databases were used to identify relevant studies published in English from the date of inception to October 23, 2012. The PubMed and Scopus search engines were used to locate studies using the following search terms: (clinical trial OR RCT OR randomized controlled trial) AND [(patellar resurfacing) OR (patellar denervation) OR (patella non-resurfacing)] AND (total knee arthroplasty) AND [(anterior knee pain) OR (AKP) OR (KSS) OR (Knee Society Score) OR (Knee Function Score) OR (WOMAC score) OR (reoperation) OR (Bristol score) OR (PF problem)]. Search strategies for Medline and Scopus are described in the appendix. Relevant studies from the reference lists of identified studies and previous systematic reviews were also explored. Selection of studies Identified studies were selected by one author (J.K.) and randomly checked by (A.A.). The titles and abstracts were initially screened, and full papers were retrieved if a decision could not be made from the abstracts. The reasons for ineligibility or exclusion of studies were recorded (Fig. 1). Inclusion criteria Randomized controlled trials or quasi-experimental designs that compared clinical outcomes between patellar resurfacing and patellar denervation with patellar reshaping in primary TKR were eligible if the following criteria were fulfilled: • Compared clinical outcomes between patellar resurfacing or patellar denervation (with or without reshaping) with non-resurfacing. • Compared at least one of following outcomes: Visual Analog Score (VAS), Knee Society Knee Score (KS) and Function Score (FS), WOMAC score, Bristol Knee Score, anterior knee pain, postoperative infection, patella fracture, PF problems, and reoperation rates. • Had sufficient data to extract and pool, i.e., the reported mean, standard deviation (SD), the number of subjects according to treatments for continuous outcomes, and the number of patients according to treatment for dichotomous outcomes. Data extraction
Materials and methods Search strategy A systematic review and network meta-analysis were performed in accordance with Preferred Reporting Items for
13
Two reviewers (J.K. and A.A.) independently performed data extraction using standardized data extraction forms. General characteristics of the study [e.g., mean age, gender, body mass index (BMI), mean follow-up time, pain score (VAS), and functional scores (KS, FS) at baseline] were
Knee Surg Sports Traumatol Arthrosc 36 studies retrieved from Medline
304 studies retrieved from Scopus 315 left after removed duplicates
299 studies were ineligible:
16 studies left for reviewing full paper
2 studies from Hand searching from reference list
•
293 non-RCTs
•
no outcomes of interest
•
1 no interventions
•
5 non English
18 studies left for full paper
3 studies of denervation of patella left for review
15 studies of patella resurfacing left for review
Visual analog score Denervation vs non-resurfacing: 2 study Resurfacing vs non-resurfacing: 3 study
Knee score Denervation vs non-resurfacing: 2 Resurfacing vs non-resurfacing: 11
Function score Denervation vs non-resurfacing: 2 study Resurfacing vs non-resurfacing: 7 study
Anterior knee pain Denervation vs non-resurfacing: 1 study Resurfacing vs non-resurfacing: 4 studies
Patella problem Resurfacing vs non-resurfacing: 8 study
Patella fracture Denervation vs non-resurfacing: 3 study Resurfacing vs non-resurfacing: 11 study
Infection Denervation vs non-resurfacing: 3 study Resurfacing vs non-resurfacing: 12 studies
Reoperation due to patella Denervation vs non-resurfacing: 3 study Resurfacing vs non-resurfacing: 14 study
Fig. 1 Flow of study selection
extracted. The number of subjects, mean, and SD of continuous outcomes [i.e., pain by VAS, KS, and FS] between groups were extracted. Cross-tabulated frequencies between treatment and all dichotomous outcomes (anterior
knee pain, infection, patella fracture, PF problems, and reoperation due to patella problems) were also extracted. Any disagreements were resolved by discussion and consensus with a third party (C.S.).
13
Risk of bias assessment Two authors (J.K. and A.A.) independently assessed risk of bias for each study. Six study quality domains were considered, consisting of sequence generation, allocation concealment, blinding (participant, personnel, and outcome assessors), incomplete outcome data, selective outcome reporting, and other sources of bias [23]. Disagreements between two authors were resolved by consensus and discussion with a third party (C.S.). Outcomes The outcomes of interest were pain VAS, Knee Society Knee Score, Knee Society Functional Score, anterior knee pain, infection, patella fracture, PF problems, and reoperation due to patella problems. Methods of measure for these outcomes were used according to the original studies. Briefly, this includes the VAS pain scale (0–10), KS that consists of pain (0–50), range of motion (0–25), stability (0–25) with total scores ranging from 0 to 100, and FS that consists of walking distance (0–50), and stair climbing (0–50) with a total score ranging from 0 to 100. Postoperative complications (anterior knee pain, infection, patella fracture, PF problems, and reoperation due to patella problems) were considered. Statistical analysis Direct comparisons of continuous outcomes measured at the end of each study between patellar resurfacing versus non-resurfacing and patellar denervation versus non-resurfacing were pooled using an unstandardized mean difference (UMD). Heterogeneity of the mean difference across studies was checked using the Q-statistic, and the degree of heterogeneity was quantified using the I2 statistic. If heterogeneity was present as determined by a statistically significant Q-statistic or by I2 >25 %, the UMD was estimated using a random effects model; otherwise, a fixed effects model was applied. For dichotomous outcomes, a relative risk (RR) of postoperative complication of treatment comparisons at the end of each study was estimated and pooled. Heterogeneity was assessed using the previous method. If heterogeneity was present, the Dersimonian and Laird method [2] was applied for pooling. If not, the fixed effects model by inverse variance method was applied. Meta-regression was applied to explore the source of heterogeneity (e.g., mean age, percentage of females, BMI, and follow-up time) if data were available. Publication bias was assessed using contourenhanced funnel plots [32, 33] and Egger tests [12]. For indirect comparisons, network meta-analyses were applied to assess all possible effects of treatment if summary data were available for pooling [25, 42, 44]. A linear
13
Knee Surg Sports Traumatol Arthrosc
regression model, weighted by inverse variance, was applied to assess the treatment effects for continuous outcomes. For postoperative complications, a mixed-effect Poisson regression was applied to assess treatment effects [25]. Summary data were expanded to individual patient data using the “expand” command in STATA. Treatment was considered as a fixed-effect, whereas the study variable was considered as a random-effect in a mixed-effect model. The pooled RR and its 95 % confidence intervals (CIs) were estimated by exponential coefficients of treatments. All analyses were performed using STATA version 12.0 [44]. A P value
