Validation of a French patient-reported outcome measure for patello-femoral disorders: The Lille Patello-Femoral Score

Patellar dislocation recurrence after pediatric MPFL reconstruction: Bone tunnels and soft tissues versus suture anchors and interference screw

BACKGROUND

Several Medial Patellofemoral Ligament (MPFL) reconstruction techniques have been developed, and those with soft tissue fixation are often preferred in children because they allow the growth cartilage to be preserved. Nevertheless, the recurrence rate of patellar dislocation varies widely from one series to another, with no clear superiority of one technique in the pediatric setting. The objectives of this study were to compare the results of two tendon graft fixation techniques (tendon-tendon fixation and anchor-screw fixation) by analyzing: 1) the rate of patellar dislocation recurrence, 2) clinical outcomes, 3) tourniquet time and 4) complication rate.

HYPOTHESIS

The two tendon graft fixation techniques used in MPFL reconstruction are equivalent in terms of the patellar dislocation recurrence rate.

PATIENTS AND METHODS

This is a retrospective comparative study including 57 patients with a median age of 14 years (12-15 years) who underwent MPFL reconstruction between 2016 and 2020. The tendon graft was fixed upon itself, after passing through a patellar tunnel (Group A: tendon-tendon fixation; n=29) or by two anchors and an interference screw (Group B: anchor-screw fixation; n=28). The preoperative radiographic data were comparable in the two groups: patellar height [A: 1.3 (interquartile range (IQR): 1.2-1.4) / B: 1.2 (IQR: 1-1.4) (p=0.21)], tibial tuberosity to trochlear groove (TTTG) distance [A: 16 (IQR: 13-19) / B: 13.5 (IQR: 11.5-18.8) (p=0.12)], patellar tilt [A: 25 (IQR: 20-35) / B: 24.5 (IQR: 21-32) (p=0.93)]. For each technique, the rate of patellar dislocation recurrence, clinical and functional results (Kujala score, Marx activity score, Lille patellofemoral score), complications (pain, stiffness, revision) were analyzed. In addition to MPFL repair, 13 patients (2 in Group A, 11 in Group B) underwent additional orthopedic procedures to enhance patellar stability.

RESULTS

no patients were lost to follow-up and the median follow-up was 30 months (IQR: 20-38). The dislocation recurrence rate was higher in Group A, 6.9% (2/29) compared to none in Group B. The clinical results were comparable for the two groups with a Kujala score [A: 94 (IQR: 89-100) / B: 92 (IQR: 87.5-94.5) (p=0.12)]; Marx score [A: 10 (IQR: 7-11) / B: 9.5 (IQR: 7.5-12) (p=0.89)] and Lille patellofemoral score [A: 97 (IQR: 91-100) / B: 94 (IQR: 90-98) (p=0.21)]. The tourniquet time was shorter in Group A than in Group B, 61minutes (IQR: 52-71) versus 85minutes (IQR: 55-115) (p=0.024) excluding additional orthopedic procedures. The complication rate was 17.2% (5/29) in Group A (dislocation n=2, stiffness n=2, ATT (anterior tibial tuberosity) revision with screw removal n=1) and 10.7% (3/28) in B (pain n=1, ATT revision with screw removal n=2) (p=0.35).

CONCLUSION

Clinically, anchor-screw fixation appears to reduce the risk of patellar dislocation recurrence but this could not be statistically tested. On the other hand, the two techniques are comparable in terms of the functional results.

LEVEL OF EVIDENCE

III; retrospective case-control study.

Isolated MPFL reconstruction with soft tissue femoral fixation technique in 54 skeletally immature patients: Clinical outcomes at 2 years follow-up. A French multicenter retrospective study

BACKGROUND

Medial patello-femoral ligament (MPFL) reconstruction is one of the therapeutic options to treat patellofemoral instability. Classically, a à la carte treatment of skeletal and ligament abnormalities is described. This option is difficult to achieve in children because bony procedures can damage the femoral and/or tibial growth plate. The objective was to evaluate a strategy for isolated reconstruction of the MPFL in the treatment of objective patellar instabilities in children, in a large cohort. The return to sport, knee function and pain or discomfort were studied as secondary endpoints.

METHODS

This French multicenter retrospective study included 54 pediatric patients with objective patellofemoral instability. Patients were included if they had presented at least 2 episodes of objective patella dislocation. A Deie-like technique with gracilis tendon graft, soft tissue femoral fixation and patellar bone tunnels for patellar fixation was used. Recurrence of dislocation was studied as the primary endpoint, and the recurrence rate was compared with the literature. A comparison of functional scores (Kujala, Lille femoro-patellar instability score or LFPI Score and Tegner activity score) and NRS between pre- and postoperative was studied as a secondary objective.

RESULTS

A recurrence of femoro-patellar instability was observed for five patients within 2 years follow up (9%). A significant improvement of the Kujala, LFPI score, Tegner and NRS scores was observed (p<0.001).

CONCLUSION

Isolated reconstruction of the MPFL presents a risk of recurrence of 9% at 2years follow-up. This technique significantly improves the functional scores of the knee. This modified Deie technique provides good clinical and functional results, allowing return to sports with an acceptable risk of recurrence of patellar dislocation, similar to those observed in the literature. Isolated MPFL reconstruction as a first-line treatment appears to be a reliable and effective technique in terms of recurrence of dislocation and functional scores. It allows early recovery and rehabilitation and has lower morbidity than procedures requiring bone gestures.

LEVEL OF EVIDENCE

III, retrospective comparative study.

Patient-reported outcome measures for patellofemoral disorders: a systematic review

INTRODUCTION

Patellofemoral conditions include, but are not limited to, anterior knee pain syndrome and patellar instability. Patients and surgeons may find it difficult to identify the specific source of the symptoms and clinical scenarios, so patient-reported outcome measures (PROMs) may be a useful diagnostic aid. There are a number of available PROMs for patellofemoral conditions, which are often used indistinctly. This systematic review explores the available PROMs for patellofemoral conditions, their use and methodological quality.

METHODS

A systematic review was conducted, searching for scientific articles relating to PROMs in patellofemoral conditions, from inception to July 2022. Scoring systems including physician-directed or imagining assessment were not included. All types of conditions in the patellofemoral joint were considered.

RESULTS

Twenty-two relevant PROMs were encountered, divided into four categories: eight PROMs for anterior knee pain syndrome, five for patellar instability, four for other patellofemoral conditions and five for non-specific PROMs.

CONCLUSIONS

While many PROMs have been found used in patellofemoral research, only few of them have showed sufficient methodological quality. In addition, PROMs employed in PF literature are often inaccurately chosen. This review may help authors to better understand the characteristics of specific patellofemoral PROMs, in order to select the more appropriate and recommended ones.

LEVEL OF EVIDENCE

Level II.

Are modern knee outcomes scores appropriate for evaluating anterior knee pain and symptoms after total knee arthroplasty?

BACKGROUND

Up to 45% of patients who undergo primary total knee arthroplasty (TKA) with contemporary implants have residual anterior knee pain. While a specific evaluation of anterior knee symptoms is mandatory, little is known about the capability of patellofemoral scores to be used individually. This study aimed to assess the distribution of patellofemoral scores after TKA from a uniform cohort and to investigate their external validity and ability to detect anterior knee symptoms using floor and ceiling effects.

HYPOTHESIS

Patellofemoral scores have high construct validity and fewer floor/ceiling effects than general knee scores.

METHODS

We prospectively included 113 consecutive patients who underwent primary TKA for primary osteoarthritis at a single University Hospital. Clinical outcomes included patellofemoral scores (HSS Patella, Kujala and Lille scores) and general knee scores (KOOS and new KSS) at 1-year follow-up. The floor and ceiling effects were considered as significant when greater than 15%. These were determined for each score individually and for composite scores (combination of patellofemoral scores and new KSS). The construct validity of each score and their ability to detect anterior knee pain was evaluated.

RESULTS

Patellofemoral scores showed no floor effect but a significant ceiling effect (from 25% to 65%). This ceiling effect decreased when composite scores were used. The convergent validity test showed strong correlation between patellofemoral scores (from 0.741 to 0.819, p<0.00001) and a better ability to discriminate anterior knee pain than the general knee scores.

CONCLUSIONS

Patellofemoral scores showed no floor effect and a very good construct validity for anterior knee pain after TKA. However, studies aiming to monitor anterior knee symptoms after TKA should combine scoring systems to included patellofemoral-related items rather than use patellofemoral scores alone due their ceiling effects.

LEVEL OF EVIDENCE

III; prospective study.

Complications and outcomes of trochleoplasty for patellofemoral instability: A systematic review and meta-analysis of 1000 trochleoplasties

BACKGROUND

Trochleoplasty is an effective patellar stabilization procedure; however, it is associated with a risk of complications that cannot be ignored. Prior systematic reviews on this topic did not include more recent studies reporting important outcomes, particularly the long-term results of lateral elevation trochleoplasty. This led us to carry out a new meta-analysis of the various trochleoplasty procedures to specify: (1) the recurrence rate of patellofemoral dislocation; (2) the complication rates and; (3) the clinical outcomes.

PATIENTS AND METHODS

Studies reporting complications and clinical outcomes of trochleoplasty, whether or not it was combined with other procedures for patellofemoral instability, were identified in the MEDLINE, Embase, Scopus, Cochrane Library, Web of Science databases and by searching the grey literature. The primary endpoint was the recurrence of patellofemoral dislocation while the secondary endpoints were objective patellofemoral instability without dislocation, stiffness, patellofemoral osteoarthritis, subsequent surgeries and various clinical outcome scores. The results were combined in a random-effects model (weighing factor: inverse variance) when the heterogeneity was less than 80%.

RESULTS

Twenty-eight studies were included: 5 featured lateral elevation trochleoplasty, 10 about the Dejour deepening trochleoplasty, 12 about the Bereiter deepening trochleoplasty and 1 about the recession wedge trochleoplasty. A total of 1000 trochleoplasty procedures were done in 890 patients who had a follow-up of 1 to 25 years. There were 24 cases of recurrent dislocation (24/994 [2.4%]; this outcome was not reported for 6 trochleoplasties). The Dejour deepening trochleoplasty was the most effective with only 1 recurrence in 349 knees (0.28%). For the other complications, residual patellar instability without dislocation occurred in 82 of 754 knees (8% [95% CI: 3-14%]), patellofemoral osteoarthritis in 117 of 431 knees (27%), stiffness in 59 of 642 knees (7% [95% CI: 3-12%]) and the need for subsequent surgery in 151 of 904 knees (17%).

DISCUSSION

This study found a low recurrence rate for patellofemoral dislocation and residual instability. The incidence of stiffness, patellofemoral osteoarthritis and subsequent surgery remains high but differs greatly between studies. This meta-analysis showed a very large disparity between studies for most complications, which justifies the need for randomized and comparative studies to establish the role of trochleoplasty procedures in the treatment algorithm for patellar instability.

LEVEL OF EVIDENCE

IV; systematic review and meta-analysis.

Compared outcomes 16 and 25 years after lateral wedge augmentation trochleoplasty: Rate of recurrent dislocation and progression to osteoarthritis

BACKGROUND

Lateral wedge augmentation trochleoplasty (LWAT) was the earliest described trochleoplasty technique but was gradually replaced by other methods for the treatment of patello-femoral instability with trochlear dysplasia. Data on the outcomes of this procedure in adults are limited. We therefore performed a retrospective study in patients managed by LWAT to assess (1) clinical (recurrent instability and functional scores), (2) and radiological (patello-femoral osteoarthritis) outcomes.

HYPOTHESIS

LWAT is associated with a low long-term rate of recurrent patello-femoral dislocation and with no risk of progression to severe patello-femoral osteoarthritis.

MATERIAL AND METHODS

Between 1988 and 1995, LWAT was performed on 66 knees in 58 patients to treat patello-femoral instability with trochlear dysplasia. Among them, 17 knees in 13 patients were re-evaluated 16 then 25 years after surgery and were included in the study. At both time points, the following were recorded: stability, pain, the Lille patello-femoral function score, and changes in radiographic and computed tomography findings. In addition to LWAT, Insall's realignment vastus medialis advancement was performed in 4 cases, sartorius muscle transposition in 9 cases, and anterior tibial tubercle osteotomy in 10 cases.

RESULTS

No episodes of patello-femoral dislocation were recorded during the 25-year follow-up. The mean Lille patello-femoral function score (0 worst to 100 highest) was 90±15 (range, 48-99) after 16 years and 86±23 (range, 33-94) after 25 years. After 16 years, 8/17 knees had evidence of patello-femoral osteoarthritis, which was Iwano stage 1 in 7 cases and Iwano stage 2 in 1 case. Patello-femoral osteoarthritis was noted in 12 of 13 knees after 25 years but was mild (Iwano stage 1 or 2) in 8 cases. After 25 years, arthroplasty had been performed for 4 of the 17 knees, with 2 cases each of patello-femoral arthroplasty and total knee arthroplasty.

CONCLUSION

LWAT is a reliable procedure that provides sustained protection against patello-femoral dislocation and good functional scores when used to treat patello-femoral instability due to trochlear dysplasia. Our results do not support claims that LWAT may be associated with high rates of severe osteoarthritis even after more than 20 years.

LEVEL OF EVIDENCE

IV, retrospective observational study with no control group.

Are modern knee outcomes scores appropriate for evaluating patellofemoral degeneration in osteoarthritis? Evaluation of the ceiling and floor effects in knee outcomes scores

INTRODUCTION

Patellofemoral (PF) degeneration plays an important role in knee function in the context of osteoarthritis. A specific evaluation of PF symptoms is needed to better understand the initial functional status of the knee before surgery. The aim of this study was to assess the validity of patient-related outcome measures (PROMs) for knee scores and PF scores in knee osteoarthritis.

HYPOTHESIS

PF scores are more reliable for evaluating anterior knee pain than global knee scores in the context of PF degeneration in osteoarthritis.

MATERIAL AND METHODS

We performed a prospective single-center study of continuous patients included between January 2017 and January 2018 in our surgical department for total knee arthroplasty (TKA) for primary knee osteoarthritis. The analysis used global knee PROMs (KOOS and new IKS) and PF-specific PROMs (HSS Patella score, Kujala score and Lille score). Floor and ceiling effects were determined for each score based on tibiofemoral and PF degeneration on radiographic views; it was considered significant when greater than 15%.

RESULTS

We included 114 TKA procedures in 113 consecutive patients. According to the Iwano classification, no significant floor or ceiling effect was found for the PF preoperative scores (0-12%). The KOOS ADL and QOL scores were particularly affected by the ceiling and floor effects, whatever the patellofemoral degeneration (23-88%). In cases of severe PF degeneration (Iwano grade 3 and 4), no significant differences in the distribution of the functional scores were found.

DISCUSSION

Modern knee outcome scores used to evaluate knee function do not monitor PF degeneration and related symptoms in the context of knee osteoarthritis according to the Iwano classification. PF scores do not have a floor and ceiling effects even if the severity of the PF degeneration is difficult to identify preoperatively. Physicians should be aware of this effect on the preoperative functional evaluation before TKA.

LEVEL OF EVIDENCE

III, comparative prospective study.

French translation and cultural adaptation of a questionnaire for patients with hip or knee prosthesis

INTRODUCTION

The Kingsbury questionnaire offers the possibility of follow-up by means of an X-ray and a simple questionnaire sent to the home address of the patient, who will not need to come in consultation if there are no problems. The questionnaire detects any anomaly in follow-up. In case of anomaly in the questionnaire or radiograph, the patient is contacted and/or seen again, as appropriate. The Kingsbury questionnaire has had no transcultural validation, and we therefore conducted a prospective study in order to 1) translate into French the questionnaire, previously validated in English; 2) adapt it for good understanding according to cultural habits; and 3) assess the translated version on a test-retest procedure.

HYPOTHESIS

The study hypothesis was that the translated questionnaire would show good test-retest reproducibility.

MATERIAL AND METHODS

The exact English version of the questionnaire was obtained directly from the authors of the index publication. A methodology of translation, back-translation and test-retest enabled assessment of the translation and of the reproducibility of the French version. The reference method of cultural adaptation of self-administered questionnaires and patient information documents was used. The questionnaire was tested prospectively.

RESULTS

One hundred patients were contacted, providing 73 clinical tests with radiographic validation and 48 complete test-retests in a representative population of total hip and total knee arthroplasty (THA, TKA). Internal coherence showed a KR-20 coefficient of 0.71 and Cronbach alpha of 0.76: e.g., good internal coherence. Item difficulty, requiring renewed contact, was low for all questions. Mean variance was low on the first 7 questions: 0.08 (range, 0.02-0.16). Correlation was close to 0.5 for each question. Analysis of reproducibility found excellent agreement (>90%) for the first 7 questions, which were binary; for question 8, agreement was good (83.3%) considering that there were 5 possible responses. For 19 of the 73 respondents, the questionnaire results indicated a need for further contact. After analysis of their radiographs, 4 needed to be seen in consultation again. The other 15 had unfavorable responses but without deterioration since the last classical consultation or any radiologic abnormality consultation, and were not called back for consultation.

CONCLUSION

The French version of the Kingsbury questionnaire provided reproducible assessment, avoiding the need to call the patient back for consultation unnecessarily. The questionnaire needs validating in a larger sample before being widely used: the present study was just a first step.

LEVEL OF EVIDENCE

IV, Prospective without control group.