Total knee replacement and patellofemoral pain

Is the patient aware of the difference between resurfaced and nonresurfaced patella after bilateral total knee arthroplasty? A systematic review of simultaneous bilateral randomized trials

Purpose

The optimal practice of patellar management in total knee arthroplasty (TKA) remains controversial. This systematic review was conducted to compare patella-related (1) patient-reported outcome measures (PROMs), (2) clinical outcomes, and (3) reoperation rates after TKA with patellar resurfacing (PR) and nonresurfacing (NPR) in single patients undergoing bilateral patellar procedures during simultaneous bilateral TKA.

Methods

This review included prospective bilateral randomized trials investigating patella-related PROMs, clinical outcomes, and reoperation (secondary resurfacing and patellar component revision) and other patella-related complications in single patients undergoing randomly assigned PR and NPR during bilateral TKA.

Results

Six studies were included. There was no difference in PROMs between PR and NPR in five studies, whereas PR was found to be superior to NPR in one study. Five studies reported similar functional outcomes and complication rates between PR and NPR, while one study found better clinical outcomes and a lower complication rate in PR. Between-group secondary resurfacing and patellar revision rates were similar in all studies.

Conclusions

The majority of patients who underwent bilateral patellar procedures could not tell the difference between PR and NPR following bilateral TKA. There were no differences in clinical outcomes or reoperation and complication rates between PR and NPR. No evidence was found to support routine PR.

Level of evidence: Therapeutic Level 1

No patella resurfacing total knee arthroplasty leads to reduction in the thickness of patellar cartilage to less than half within 5 years: a quantitative longitudinal evaluation using MRI

PURPOSE

Patellar resurfacing in total knee arthroplasty (TKA) remains controversial as recent meta-analyses have not shown its clear superiority; however, most authors recommend it because it is associated with less frequent anterior knee pain and need for reoperation. We aimed to clarify the changes in patellar cartilage thickness in no patellar resurfacing TKA using a ceramic femoral component on magnetic resonance imaging (MRI).

METHODS

Between 2009 and 2014, 40 consecutive patients (59 knees) were included in this study. All patients underwent TKA using zirconia ceramic femoral implants without patellar resurfacing. Indications for no patellar resurfacing TKA were absence of anterior knee pain, patellar compression pain, and osteoarthritic changes in the patellofemoral joint on plain radiography. The mean postoperative follow-up duration was 81.5 months (range, 25-131 months). Clinical and radiological evaluations were performed preoperatively and 5 years after TKA. Patellar cartilage thickness was evaluated preoperatively and every year for 5 years after TKA using MRI T2-weighted imaging. The patellar cartilage was divided into three regions of interest: medial, central, and lateral. To standardise the variation in patellar thickness among patients, the percent cartilage thickness was calculated.

RESULTS

The implant's position was appropriate in all cases. Compared to preoperative scores, 5 years postoperatively, the Japanese Orthopedic Association score and Oxford knee score significantly improved from 52.1 to 84.7; mean tilting angle and congruence angle did not change significantly; mean lateral shift ratio significantly increased from 7.1% to 14.6%; cartilage thickness significantly decreased (P < 0.05); and the percentage cartilage thickness of the central, medial, and lateral cartilage zones gradually thinned to less than half. Four patients underwent conversion to patellar resurfacing due to anterior knee pain, without loosening the femoral and tibial implants.

CONCLUSION

The patellar cartilage thickness decreased to less than half its preoperative level within 5 years after no patellar resurfacing TKA; this would led to clinical problems and conversion to patellar resurfacing.

LEVEL OF EVIDENCE

Level III.

Patellar Denervation with Electrocautery Reduces Anterior Knee Pain within 1 Year after Total Knee Arthroplasty: A Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

The effect of patellar denervation with electrocautery (PD) on anterior knee pain (AKP) after total knee arthroplasty (TKA) is still debated. The aim of this meta-analysis was to evaluate the current evidence regarding the use of PD in TKA without patellar resurfacing.

METHODS

A computerized search of published studies was performed in the PubMed, Embase and Cochrane Library databases in December 2019. Eligible studies were randomized controlled trials (RCTs) comparing clinical outcomes of the PD group and the non-PD group. Subgroup analyses were carried out according to the follow-up time (3, 12 months, and over 12 months) to evaluate whether the clinical effect of PD changed with time.

RESULTS

Ten RCTs were included in this meta-analysis. Pooled results showed a lower rate of AKP (Risk Ratio [RR] = 0.70; 95% confidence interval [CI], 0.50 to 0.97; P = 0.03) and a reduction in visual analogue scale (VAS) for AKP (mean difference, -0.37; 95% CI, -0.69 to -0.05; P = 0.02) in the PD group when compared to the non-PD group. Subgroup analyses found the differences in AKP incidence and VAS for AKP were significant at 3- and 12-month follow-up but not after 12-month follow-up. No significant difference was observed in functional scores between the two groups. No specific complication directly or indirectly related to PD was found.

CONCLUSION

PD can decrease the incidence and severity of AKP within 12 months after TKA, but the effect cannot be maintained after 12-month follow-up. Without significant associated complication and reoperation, the use of PD is still recommended in TKA without patellar resurfacing.

No difference in patellar position between mobile-bearing and fixed-bearing total knee arthroplasty for medial osteoarthritis: a prospective randomized study

PURPOSE

Total knee arthroplasty (TKA) is the treatment of choice for severe osteoarthritis of the knee. Many studies have been performed comparing mobile- and fixed-bearing designs; however, there are insufficient data regarding the patellar position in either system. This study aimed to compare the resultant patellar position with a mobile- versus a fixed-bearing TKA and the influence of both designs on clinical outcomes.

MATERIALS AND METHODS

In this prospective randomized study, between 2007 and 2009, 160 TKA patients were assessed; 79 received a mobile-bearing and 81 received a fixed-bearing implant, for medial compartment osteoarthritis. A posteriorly stabilized, HLS Noetos knee prosthesis (Tornier, Saint-Ismier, France) was used in all cases. The only difference between the groups was whether the tibial component incorporated a fixed or mobile bearing. The patella was resurfaced in all cases. The International Knee Society Score (KSS) and the patellar tilt and translation were compared post-operatively. Patellar translation and patellar tilt analyses were subdivided into two subgroups (< 5 mm vs > 5 mm and < 5° vs > 5°).

RESULTS

The KSS was not statistically different between the groups at a mean follow-up of 7.4 years (range 5-11 years). Patellar translation and patellar tilt were not statistically different between the groups. When considering the patellar translation subgroup analysis, a significantly increased risk of patellar translation, greater than 5 mm, was found in the mobile-bearing group compared to fixed-bearing group (OR = 2.3; p = 0.048) without generating any meaningful difference in clinical outcomes.

CONCLUSION

The theoretical advantages of mobile-bearing implants compared to fixed-bearing implants were not demonstrated in this randomized study, at mid-term follow-up. In daily practice, the choice between mobile-bearing and fixed-bearing designs should be based on the experience and clinical judgment of the surgeon.

LEVEL OF EVIDENCE

Prospective randomized study, level I.

Resurfacing versus not-resurfacing the patella in one-stage bilateral total knee arthroplasty: a prospective randomized clinical trial

Purpose

Resurfacing the patella in one-stage bilateral total knee arthroplasty (TKA) remains debatable. This study aimed to assess the mid-term outcomes of patients after one-stage bilateral TKA performed with and without patellar resurfacing, respectively, with at least five years of follow-up.

Methods

Sixty-six patients (132 knees) scheduled for first-ever one-stage bilateral TKA due to osteoarthritis received patellar resurfacing and retention, respectively, on one knee and the other, randomly selected. All patients received Scorpio NRG knee prostheses and were evaluated by radiology (anteroposterior, lateral, and axial views) pre-operatively and yearly post-operatively, for at least five years. Knee Society Score and Feller Score values were measured. Anterior knee pain, patellar clunk, and patient satisfaction were assessed.

Results

One patient died within five years of operation and four were lost to follow-up. One patient developed severe dementia and could not be constructively questioned. Therefore, 60 patients (120 knees) were finally analyzed. There were significantly improved Knee Society and Feller scores (P < 0.001) in the resurfacing group compared with the non-resurfacing group post-operatively. Anterior knee pain and patellar clunk rates were lower on the resurfaced side compared with the non-resurfaced side (P < 0.001). Meanwhile, 47% and only 7% patients preferred the resurfaced and non-resurfaced sides, respectively, at final follow-up. No revision was performed for patellofemoral complications, and no significant differences were found between the two groups in radiographic outcomes.

Conclusions

Using the Scorpio NRG knee prosthesis, patellar resurfacing is superior to non-resurfacing in patients with osteoarthritis observed for ≥ five years.

Registration trials number

NCT03600922

Key Points

• Findings Patellar resurfacing is superior to non-resurfacing in osteoarthritis (OA) patients undergoing total knee arthroplasty (TKA) with the Scorpio NRG knee prosthesis.

• Implications Patellar resurfacing should be performed in OA patients during TKA.

• Caution Several prosthesis types should be assessed in the same study setting, and multicenter studies are required before generalizability of the present findings.

Electronic supplementary material

The online version of this article (10.1007/s00264-019-04361-7) contains supplementary material, which is available to authorized users.

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.

A randomised, controlled trial of circumpatellar electrocautery in total knee replacement without patellar resurfacing: a concise follow-up at a mean of 3.7 years

In the absence of patellar resurfacing, we have previously shown that the use of electrocautery around the margin of the patella improved the one-year clinical outcome of total knee replacement (TKR). In this prospective randomised study we compared the mean 3.7 year (1.1 to 4.2) clinical outcomes of 300 TKRs performed with and without electrocautery of the patellar rim: this is an update of a previous report. The overall prevalence of anterior knee pain was 32% (95% confidence intervals [CI] 26 to 39), and 26% (95% CI 18 to 35) in the intervention group compared with 38% (95% CI 29 to 48) in the control group (chi-squared test; p = 0.06). The overall prevalence of anterior knee pain remained unchanged between the one-year and 3.7 year follow-up (chi-squared test; p = 0.12). The mean total Western Ontario McMasters Universities Osteoarthritis Indices and the American Knee Society knee and function scores at 3.7 years' follow-up were similar in the intervention and control groups (repeated measures analysis of variance p = 0.43, p = 0.09 and p = 0.59, respectively). There were no complications. A total of ten patients (intervention group three, control group seven) required secondary patellar resurfacing after the first year. Our study suggests that the improved clinical outcome with electrocautery denervation compared with no electrocautery is not maintained at a mean of 3.7 years' follow-up.

Determinants of anterior knee pain following total knee replacement: a systematic review

PURPOSE

Anterior knee pain (AKP) following total knee replacement (TKR) is both prevalent and clinically relevant. The purpose of this study was to systematically review the peer-reviewed literature, and to identify and assess the different modifiable and non-modifiable determinants that may be associated with the development of AKP in patients following primary TKR.

METHODS

A systematic computerized database search (Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, and Google Scholar) was performed in January 2012. The quality of the studies was assessed using the GRADE approach.

RESULTS

A total of 54 articles met the inclusion criteria. Variables that have been researched with regard to the prevalence of AKP include patient and knee-specific characteristics, prosthetic design, operative technique, treatment of the patella, and time of assessment. A weak correlation with AKP was found for specific retained presurgery gait patterns. A weak recommendation can be given for the use of femoral components with a posterior centre of rotation, resection of Hoffa's fat pad, patellar rim electrocautery, and preventing combined component internal rotation. The correlation between postsurgical AKP and the degree of patellar cartilage wear, tibial component bearing strategies, and patellar resurfacing is inconclusive. Due to substantial heterogeneity of the included studies, no meta-analysis was performed.

CONCLUSIONS

No single variable is likely to explain the differences in the reported rates of AKP, although variables leading to abnormal patellofemoral joint loading appear to be of special significance.

LEVEL OF EVIDENCE

III.

No difference in anterior knee pain between a fixed and a mobile posterior stabilized total knee arthroplasty after 7.9 years

PURPOSE

The presence of anterior knee pain remains one of the major complaints following total knee arthroplasty (TKA). Since the introduction of the mobile TKA, many studies have been performed and only a few show a slight advantage for the mobile. In our short-term follow-up study, we found less anterior knee pain in the posterior stabilized mobile knees compared to the posterior stabilized knees. The concept of self-alignment and the results from our short-term study led us to form the hypothesis that the posterior stabilized mobile knee leads to a lower incidence of anterior knee pain compared to the posterior stabilized fixed knee. This study was designed to see whether this difference remains after 7.9 years in the follow-up. A secondary line of enquiry was to see whether one was superior to the other regarding pain, function, quality of life and survival.

METHODS

This current report is a 6-10-year (median 7.9 years) follow-up study of the remaining 69 patients with a cemented three-component TKA for osteoarthritis in a prospective, randomized, double-blinded clinical trial.

RESULTS

In the posterior stabilized group, five of the 40 knees (13%) versus five of the 29 posterior stabilized mobile group (17%) experienced anterior knee pain. No differences were observed with regard to ROM, VAS, Oxford 12-item knee questionnaire, SF-36, HSS patella, Kujala or the AKSS score. Patients with anterior knee pain reported more pain, lower levels of the AKSS, HSS patella and the Kujala scores than the patients without anterior knee pain.

CONCLUSION

In the current clinical practice, the appearance of anterior knee pain persists as a problem; simply changing to a mobile bearing does not seem to be the solution. The posterior stabilized mobile total knee did not sustain the advantage of less anterior knee pain, compared with the posterior stabilized fixed total knee arthroplasty.

LEVEL OF EVIDENCE

Therapeutic study, Level II.

A randomised, controlled trial of circumpatellar electrocautery in total knee replacement without patellar resurfacing

The efficacy of circumpatellar electrocautery in reducing the incidence of post-operative anterior knee pain is unknown. We conducted a single-centre, outcome-assessor and patient-blinded, parallel-group, randomised, controlled trial to compare circumpatellar electrocautery with no electrocautery in total knee replacement in the absence of patellar resurfacing. Patients requiring knee replacement for primary osteoarthritis were randomly assigned circumpatellar electrocautery (intervention group) or no electrocautery (control group). The primary outcome measure was the incidence of anterior knee pain. A secondary measure was the standardised clinical and patient-reported outcomes determined by the American Knee Society scores and the Western Ontario and McMaster Universities (WOMAC) osteoarthritis index. A total of 131 knees received circumpatellar electrocautery and 131 had no electrocautery. The overall incidence of anterior knee pain at follow-up at one year was 26% (20% to 31%), with 19% (12% to 26%) in the intervention group and 32% (24% to 40%) in the control group (p = 0.02). The relative risk reduction from electrocautery was 40% (9% to 61%) and the number needed to treat was 7.7 (4.3 to 41.4). The intervention group had a better mean total WOMAC score at follow-up at one year compared with the control group (16.3 (0 to 77.7) versus 21.6 (0 to 76.7), p = 0.04). The mean post-operative American Knee Society knee scores and function scores were similar in the intervention and control groups (knee score: 92.4 (55 to 100) versus 90.4 (51 to 100), respectively (p = 0.14); function score: 86.5 (15 to 100) versus 84.5 (30 to 100), respectively (p = 0.49)). Our study suggests that in the absence of patellar resurfacing electrocautery around the margin of the patella improves the outcome of total knee replacement.