Clinical outcomes of rehabilitation for patients following lateral patellar dislocation: a systematic review

Combined Hip and Knee Strengthening Compared With Knee Strengthening for Individuals With Lateral Patellar Dislocation: A Single-blind, Superiority, Randomized Controlled Trial

Objective

To investigate whether a combined hip and knee muscle strengthening program is superior to a knee strengthening program for people after lateral patellar dislocation (LPD).

Design

Single-blind, superiority, randomized controlled trial with 48 weeks follow-up.

Setting

Physiotherapy out-patient clinic.

Participants

Forty individuals aged 16 or older, with a history of non-traumatic LPD were randomized to a knee-based strengthening (KBSG) or quadriceps and hip strengthening exercise (HQSG) program (N=40). Inclusion criteria included a positive apprehension sign, pain on palpation along the medial retinaculum, and J sign. Exclusion criteria included restricted range of motion (<90° knee flexion), and traumatic or postsurgical LPD.

Interventions

Concealed randomization was performed using random permuted blocks of size 4. Individuals received their corresponding exercise program according to randomization and group allocation: knee-based strengthening (n=20) or combined hip and quadriceps strengthening (n=20) twice weekly for 8 weeks over 16 appointments.

Main Outcome Measures

Primary outcome was the Lysholm Knee Score. Secondary outcomes included Numerical Pain Ratings Scale (NPRS) at rest and during effort, Norwich Patellar Instability Score (NPIS), Kujala Anterior Knee Pain Scale (AKPS), Lower Extremity Functional Scale (LEFS), 4 domains of the WHOQOL-Bref, and recurrence rate. Patient-reported outcome measures were assessed from the baseline to 48 weeks. Assessments were performed by a physiotherapist who was blinded to the group allocation. Data were analyzed by using a repeated-measures ANOVA model with Tukey's post hoc test after an intention-to-treat principle.

Results

At the primary time-point of 8 weeks, there were no substantial between-group differences in the Lysholm Knee Score: mean difference=-6.8 (95% CI -14.3 to 3.7); NPIS: mean difference=23.5 (95% CI 5.6 to 41.3); AKPS: mean difference=-1.54 (95% CI -8.6 to 5.6), NPRS at rest and during effort (mean difference=0.32 (95% CI -0.37 to 1); and mean difference=0.68 (95% CI -0.9 to 1.86); LEFS mean difference=-1.08 (95% CI -5.9 to 2.4), WHOQOL-Bref domains (physical health: mean difference=-0.12, (95% CI -1.26 to 1.02); psychological: mean difference=-0.32 (95% CI -2.04 to 1.4); social relations: mean difference=-0.7 (95% CI -2.2 to 0.82); environment: mean difference=0.44 (95% CI -1 to 1.9), and recurrence rate (P=.69).

Conclusion

This study indicates that combined hip and knee muscle strengthening is not superior to knee-based strengthening for LPD treatment. The limitations stemming from the underpowered nature of the trial must be acknowledged, concerning the potential oversight of moderate intervention effects.

Consensus-Based Guidelines for Management of First-Time Patellar Dislocation in Adolescents

BACKGROUND

The management of first-time patellar dislocation remains variable, with limited evidence to support or compare different operative and nonoperative modalities. The primary aim was to establish consensus-based guidelines for different components of nonoperative treatment following a first-time patellar dislocation. The secondary aim was to develop guidelines related to management after failed nonoperative treatment. The tertiary aim was to establish consensus-based guidelines for the management of first-time patellar dislocation with a concomitant osteochondral fracture.

METHODS

A 29-question, multiple-choice, case-based survey was developed by 20 members of the Patellofemoral Research Interest Group of the Pediatric Research in Sports Medicine Society. The survey consisted of questions related to demographic information, management of first-time patellar dislocation without an osteochondral fracture, and management of first-time patellar dislocation with a 2 cm osteochondral fracture. The survey underwent 2 rounds of iterations by Patellofemoral Research Interest Group members and the final survey was administered to Pediatric Research in Sports Medicine members, using REDCap. Consensus-based guidelines were generated when more than 66% of respondents chose the same answer.

RESULTS

Seventy-nine of 157 (50%) eligible members responded. Sixty-one were orthopaedic surgeons and 18 were primary sports medicine physicians. Eleven consensus-based guidelines were generated based on survey responses. Those that met the criteria for consensus included initial knee radiographs (99% consensus), nonoperative treatment for first-time patellar dislocation without an osteochondral fracture (99%), physical therapy starting within the first month postinjury (99%), with return to sport after 2 to 4 months (68%) with a brace (75%) and further follow-up as needed (75%). Surgical treatment was recommended if there were patellar subluxation episodes after 6 months of nonoperative treatment (84%). Patellar stabilization should be considered for a first-time dislocation with an osteochondral fracture (81.5%).

CONCLUSION

Consensus-based guidelines offer recommendations for the management of first-time patellar dislocation with or without an osteochondral fracture. Several changing trends and areas of disagreement were noted in clinical practice.

CLINICAL RELEVANCE

In the absence of high-level evidence, consensus-based guidelines may aid in clinical decision-making when treating patients following a first-time patellar dislocation. These guidelines highlight the evolving trends in clinical practice for the management of first-time patellar dislocation. Areas not reaching consensus serve as topics for future research.

The influence of directional preference on lateral patellar dislocation: a case report

BACKGROUND

There is little consensus on the conservative management of lateral patellar dislocations (LPD). Mechanical diagnosis and therapy (MDT) is an established classification system in the spinal and extremity population. This case report describes the use of MDT in the management and classification of a patient with LPD.

CASE DESCRIPTION

The patient was a 20-year-old female with a 3-month history of left knee pain precipitated by a lateral patellar dislocation. The patient described pain and a feeling of instability with standing and walking and limitations in work and recreational activities which involve lifting, squatting, and running. Based on the patient's response to repeated end range knee movements, the patient was found to have a directional preference (DP) for knee extension and instruction in performance of knee extension DP exercises was provided.

OUTCOMES

The patient's knee examination and subsequent intervention included her responses to repeated end range knee movements. Her knee pain was abolished, and strength, function, and motion were fully restored in five visits. A minimal clinically important difference (MCID) was achieved on the Lower Extremity Functional Scale (LEFS). At discharge, the patient was able to independently manage symptoms and perform all work and recreational activities at a pre-injury level and these improvements were maintained at a 9-month follow-up.

DISCUSSION

There are various management strategies for lateral patellar dislocation. This case demonstrated the use of classifying, subgrouping, and treating a patient with lateral patellar dislocation using the principle of DP.

CONCLUSION

The patient's outcomes suggest that MDT may be used in the nonoperative management of people with LPD who present with a DP.

The Novelty of Orthopedic Rehabilitation After Conservative Management for Patellar Dislocation With Partial Tear of Medial Meniscus and Early Osteoarthritis in a 31-Year-Old Female

Primary patellar dislocation or first-time patellar dislocation is the second most frequent cause of knee injuries which overall accounts for about 3% of other knee injuries. The patellofemoral joint is formed by the patella connecting to the femoral trochlea and creates both static and dynamic structures of the knee. There are basically three types of patellar dislocation: superior, lateral, and medial. The lateral dislocation is the most frequent one. Females are more vulnerable and are at higher risk than males. Muscular weakness or muscular imbalance leads to patellar instability, and ultimately to dislocation. The recurrence rate after primary patellar dislocation is 15-60%. This case report is of a 31-year-old female with patella dislocation with a medial meniscal tear and a case of early osteoarthritis for whom we planned goal-oriented physiotherapy rehabilitation week-wise and progressed every week. The assessment was taken before and after physiotherapy rehabilitation. The patient was managed conservatively with a long knee brace, and physiotherapy started after one month. Due to prolonged immobilization, the patient suffered from quadriceps muscle atrophy. The physiotherapist focused on biomechanism and got the expected results in pain reduction, regaining strength, and improving range of motion, and the patient was able to walk properly without taking any support after rehabilitation.

Surgeon and physiotherapist approaches to operative or non-operative management of people with recurrent patellar dislocation: A case-based UK survey

BACKGROUND

Physiotherapists are often key decision-makers on when to refer patients with recurrent patellar dislocation for surgical opinion. Limited guidance exists to aid this decision. Differences in orthopaedic surgeons' and physiotherapists' views on which patients and when to refer people for surgical consideration or non-operative care may affect outcome. This study aimed to explore orthopaedic surgeons and physiotherapists decision-making surrounding treatment opinions for patients with recurrent patellar dislocation.

METHODS

An online survey performed. UK registered and practicing orthopaedic surgeons and physiotherapists were invited to participate. The survey utilised two vignettes and a series of related questions to ascertain respondents' views on decision-making to surgical referral for people with recurrent patellar dislocation. Data were analysed using descriptive statistics and inferential statistical tests to explore factors related to responses.

RESULTS

Eighty four respondent surveys were analysed (38 surgeons, 46 physiotherapists). Overall, there was a low level of agreement amongst respondents for the management of the vignettes (k = 0.215, p = < 0.0005). Some disparity existed between the professions on the definition of recurrent patellar dislocations and the clinical features which may require an early surgical assessment. Physiotherapists were three times more likely to delay a surgical opinion for the vignettes presented in this study than the surgeons.

CONCLUSION

This is the first study to investigate orthopaedic surgeons' and physiotherapists' views on decision-making around surgical or non-operative management for recurrent patellar dislocations. High-quality research is required to underpin explicit guidance on decision-making regarding management of recurrent patellar dislocation.

Lateral Patellar Instability

➤

Patellar instability represents a common problem with an evolving understanding and multifactorial pathoetiology. Treatment plans should be based on the identification of contributing anatomical factors and tailored to each individual patient.

➤

Risks for recurrent instability are dependent on several patient-specific factors including patella alta, increased tibial tubercle-to-trochlear groove (TT-TG) distance, trochlear dysplasia, younger skeletal age, and ligamentous laxity.

➤

Cartilage or osteochondral lesions and/or fractures are commonly observed in first-time patellar dislocation, and magnetic resonance imaging (MRI) should be strongly considered. Advanced imaging modalities, such as computed tomography (CT) or MRI, should also be obtained preoperatively to identify predisposing factors and guide surgical treatment.

➤

Medial patellofemoral ligament (MPFL) reconstruction with anatomical femoral tunnel positioning is associated with lower recurrence rates compared with MPFL repair and has become a common and successful reconstructive surgical option in cases of instability.

➤

Lateral retinacular tightness can be addressed with lateral retinacular release or lengthening, but these procedures should not be performed in isolation.

➤

Tibial tubercle osteotomy is a powerful reconstructive tool in the setting of underlying skeletal risk factors for instability and can be of particular benefit in the presence of increased TT-TG distance (>20 mm), and/or in the setting of patella alta.

➤

The indications for trochleoplasty are still developing along with the clinical evidence, but trochleoplasty may be indicated in some cases of severe trochlear dysplasia. Several surgical techniques have indications in specific clinical scenarios and populations, and indications, risks, and benefits to each are progressing with our understanding.

➤

Combined femoral derotational osteotomy and MPFL reconstruction can be considered for patients with a femoral anteversion angle of >30° to improve patient outcomes and reduce recurrence rates.

Surgical versus non-surgical interventions for treating patellar dislocation

BACKGROUND

Patellar (knee cap) dislocation occurs when the patella disengages completely from the trochlear (femoral) groove. It affects up to 42/100,000 people, and is most prevalent in those aged 20 to 30 years old. It is uncertain whether surgical or non-surgical treatment is the best approach. This is important as recurrent dislocation occurs in up to 40% of people who experience a first time (primary) dislocation. This can reduce quality of life and as a result people have to modify their lifestyle. This review is needed to determine whether surgical or non-surgical treatment should be offered to people after patellar dislocation.

OBJECTIVES

To assess the effects (benefits and harms) of surgical versus non-surgical interventions for treating people with primary or recurrent patellar dislocation.

SEARCH METHODS

We searched the Cochrane Bone, Joint and Muscle Trauma Group's Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, AMED, CINAHL, Physiotherapy Evidence Database and trial registries in December 2021. We contacted corresponding authors to identify additional studies.

SELECTION CRITERIA

We included randomised and quasi-randomised controlled clinical trials evaluating surgical versus non-surgical interventions for treating primary or recurrent lateral patellar dislocation in adults or children.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were recurrent patellar dislocation, and patient-rated knee and physical function scores. Our secondary outcomes were health-related quality of life, return to former activities, knee pain during activity or at rest, adverse events, patient-reported satisfaction, patient-reported knee instability symptoms and subsequent requirement for knee surgery. We used GRADE to assess the certainty of evidence for each outcome.

MAIN RESULTS

We included 10 studies (eight randomised controlled trials (RCTs) and two quasi-RCTs) of 519 participants with patellar dislocation. The mean ages in the individual studies ranged from 13.0 to 27.2 years. Four studies included children, mainly adolescents, as well as adults; two only recruited children. Study follow-up ranged from one to 14 years. We are unsure of the evidence for all outcomes in this review because we judged the certainty of the evidence to be very low. We downgraded each outcome by three levels. Reasons included imprecision (when fewer than 100 events were reported or the confidence interval (CI) indicated appreciable benefits as well as harms), risk of bias (when studies were at high risk of performance, detection and attrition bias), and inconsistency (in the event that pooled analysis included high levels of statistical heterogeneity). We are uncertain whether surgery lowers the risk of recurrent dislocation following primary patellar dislocation compared with non-surgical management at two to nine year follow-up. Based on an illustrative risk of recurrent dislocation in 348 people per 1000 in the non-surgical group, we found that 157 fewer people per 1000 (95% CI 209 fewer to 87 fewer) had recurrent dislocation between two and nine years after surgery (8 studies, 438 participants). We are uncertain whether surgery improves patient-rated knee and function scores. Studies measured this outcome using different scales (the Tegner activity scale, Knee Injury and Osteoarthritis Outcome Score, Lysholm, Kujala Patellofemoral Disorders score and Hughston visual analogue scale). The most frequently reported score was the Kujala Patellofemoral Disorders score. This indicated people in the surgical group had a mean score of 5.73 points higher at two to nine year follow-up (95% CI 2.91 lower to 14.37 higher; 7 studies, 401 participants). On this 100-point scale, higher scores indicate better function, and a change score of 10 points is considered to be clinically meaningful; therefore, this CI includes a possible meaningful improvement. We are uncertain whether surgery increases the risk of adverse events. Based on an assumed risk of overall incidence of complications during the first two years in 277 people out of 1000 in the non-surgical group, 335 more people per 1000 (95% CI 75 fewer to 723 more) had an adverse event in the surgery group (2 studies, 144 participants). Three studies (176 participants) assessed participant satisfaction at two to nine year follow-up, reporting little difference between groups. Based on an assumed risk of 763 per 1000 non-surgical participants reporting excellent or good outcomes, seven more participants per 1000 (95% CI 199 fewer to 237 more) reported excellent or good satisfaction. Four studies (256 participants) assessed recurrent patellar subluxation at two to nine year follow-up. Based on an assumed risk of patellar subluxation in 292 out of 1000 in the non-surgical group, 73 fewer people per 1000 (95% CI 146 fewer to 35 more) had patellar subluxation as a result of surgery. Slightly more people had subsequent surgery in the non-surgical group. Pooled two to nine year follow-up data from three trials (195 participants) indicated that, based on an assumed risk of subsequent surgery in 215 people per 1000 in the non-surgical group, 118 fewer people per 1000 (95% CI 200 fewer to 372 more) had subsequent surgery after primary surgery.

AUTHORS' CONCLUSIONS

We are uncertain whether surgery improves outcome compared to non-surgical management as the certainty of the evidence was very low. No sufficiently powered trial has examined people with recurrent patellar dislocation. Adequately powered, multicentre, randomised trials are needed. To inform the design and conduct of these trials, expert consensus should be achieved on the minimal description of both surgical and non-surgical interventions, and the pathological variations that may be relevant to both choice of these interventions.

Medial patellofemoral ligament reconstruction is superior to active rehabilitation in protecting against further patella dislocations

PURPOSE

Isolated reconstruction of the medial patellofemoral ligament (MPFL-R) has become the predominant stabilizing procedure in the treatment of recurrent lateral patellar dislocation (LPD). To minimize the risk of re-dislocations, isolated MPFL-R is recommended in patients with no significant trochlea dysplasia and tibial tuberosity trochlear groove distance < 20 mm on computed tomography (CT). Incidentally, these criteria are the same that are used to identify first time LPD patients where conservative treatment is recommended. The purpose of this study was therefore to compare MPFL-R with active rehabilitation for patients with recurrent LPD (RLPD) in absence of the above mentioned underlying anatomical high-risk factors for further patellar dislocations.

METHODS

RLPD-patients aged 12-30 without underlying anatomical high-risk factors for further LPD were randomized into treatment either with isolated MPFL-R or active rehabilitation provided and instructed by a physiotherapist. All patients underwent diagnostic arthroscopy for concomitant problems. The main outcome measure was persistent patellar instability at 12 months. Knee function at baseline and 12 months was asses using the following patient reported outcomes measures (PROMS); KOOS, Kujala, Cincinnati knee rating, Lysholm score and Noyes sports activity rating scale.

RESULTS

Between 2010 and 2019, 61 patients were included in the study (MPFL-R, N = 30, Controls, N = 31). Persistent patellar instability at 12 months was reported by 13 (41.9%) controls, versus 2 (6.7%) in the MPFL-group (RR 6.3 (95% CI 1.5-25.5). No statistically significant differences in activity level were found between the MPFL-group and the Controls at neither baseline nor follow up. The patients with persistent instability at 12 months did not score significantly lower on any of the PROMs compared to their stable peers, regardless of study group.

CONCLUSION

Patients with recurrent patellar dislocations have a six-fold increased risk of persistent patellar instability if treated with active rehabilitation alone, compared to MPFL-R in combination with active rehabilitation, even in the absence of significant anatomical risk factors. Active rehabilitation of the knee without MPFL-R improves patient reported knee function after one year, but does not protect against persistent patellar instability.

Hip and Knee Weakness and Ankle Dorsiflexion Restriction in Individuals Following Lateral Patellar Dislocation: A Case-Control Study

OBJECTIVE

To explore the relationship between ankle dorsiflexion range of motion (ROM) and hip and knee muscle strength between patients with a history of patellar dislocation (PD) to healthy controls.

DESIGN

Case-control study.

SETTING

Orthopedical specialty outpatient clinic at a tertiary hospital.

PARTICIPANTS

Eighty-eight individuals were recruited; 44 individuals aged 16 years or older, of both sexes, with a history of at least one episode of atraumatic unilateral or bilateral PD requiring emergency care (14 men; 30 women; mean age 20 years) and 44 healthy (control) individuals (11 men; 33 women; mean age 21 years) matched for age, weight, and height to PD cases.

INTERVENTION

Assessment of hip and knee strength and ankle dorsiflexion ROM.

OUTCOME MEASURES

Ankle dorsiflexion ROM was assessed through the lunge test with a goniometer. Hip and knee muscle strength was evaluated through isometric hand-held dynamometry. Differences between healthy and control individuals were assessed using Student t Tests and Mann-Whitney U Test.

RESULTS

Patellar dislocation individuals presented with a reduced ankle dorsiflexion ROM [mean difference (MD): 9 degrees; effect size (ES): 1.39; P < 0.001] and generalized hip and knee weakness (MD range: 4.74 kgf to 31.4 kgf; ES range: 0.52-2.35; P < 0.05) compared with healthy subjects.

CONCLUSION

Individuals with a history of PD have reduced ankle dorsiflexion ROM and hip and knee muscle strength compared with healthy controls.

Objectively quantified lower limb strength recovery in people treated surgically or non-surgically after patellar dislocation: A systematic review

OBJECTIVE

Synthesize evidence on objectively quantified lower limb strength recovery in people treated surgically or non-surgically after patellar dislocation.

METHODS

MEDLINE, EMBASE, Cochrane Library, SPORTDiscus, PEDro, AMED and CINAHL databases were last searched on July 30th, 2020 for randomized controlled trials and observational studies that objectively quantified lower limb strength in people (any age or sex) treated surgically or non-surgically after patellar dislocation.

RESULTS

24 studies were included (877 participants, median age 20.7). All assessed knee extension strength, 11 knee flexion strength, three hip abduction strength, two hip external rotation strength, and one hip flexion, extension, adduction, and internal rotation strength. One randomized controlled trial judged at high risk of bias and two cohort studies with methodological limitations compared lower limb strength recovery between surgically and non-surgically treated people, with conflicting findings. After surgery, median long-term (>8 months) knee extension strength was 82.5% (IQR 78.5-88.2; 13 studies) of the unaffected leg and knee flexion strength was 91.5% (IQR 90.7-96.9; five studies). After non-surgical treatment, median long-term knee extension strength was 86% (IQR 79.3-87.4; four studies) and mean flexion strength ranged from 95.2 to 96.7% (two studies). Mean hip strength was always >90% (two studies). Two redislocations during eccentric isokinetic knee testing and knee pain during isokinetic knee extension testing were reported as adverse events.

CONCLUSIONS

Available evidence indicates that after patellar dislocation, knee extension strength deficits in the affected limb are frequently observed and can persist long term, but this remains uncertain due to the limitations of relevant included studies. Whether lower limb strength recovery differs between people treated surgically and those treated non-surgically after patellar dislocation also remains uncertain.

TRIAL REGISTRATION

(PROSPERO CRD42019139533).

Do the quadriceps and hamstring muscles have an effect on patella stability in trochlear dysplasia?

Introduction

Trochlear dysplasia (TD) is a condition that is characterized by the presence of either a flat or convex trochlear, which impedes the stability of the patellofemoral joint (PFJ). The PFJ function is dependent on many different structures that surround the knee joint. The aim of this study was to analyse all the muscle components around the PFJ and identify whether gross muscle imbalance could contribute to the stability of the patella in TD.

Material and methods

The average cross-sectional area (CSA) and cross-sectional area ratio (CSAR) of each muscle of the thigh region in subtypes of TD was evaluated and compared to normal knee joints. Ninety-eight patients (196 knees in total) were included in the study.

Results

Of the 196 knee joints that were reviewed, 10 cases were found to be normal. In total, 186 cases were positive for TD. The majority consisted of type C. The hamstring muscles showed variable results. The vastus medialis muscle was larger in comparison to the vastus lateralis muscle over all the different TD subtypes; however, no statistical significance was identified. There was a marked statistical significance between the quadriceps and hamstring muscles, especially when comparing this to the normal knees within our cohort.

Conclusions

This study revealed no significant difference in the effect of the thigh muscle CSA on the stability of the PFJ in TD. Further research is required to establish the roles of the different muscles around PFJ in the prevention of TD dislocation.

The quantitative influence of current treatment options on patellofemoral stability in patients with trochlear dysplasia and symptomatic patellofemoral instability - a finite element simulation

BACKGROUND

Trochlear dysplasia is highly associated with patellofemoral instability. The goal of conservative and surgical treatment is to stabilize the patella while minimizing adverse effects. However, there is no literature investigating the quantitative influence of different treatment options on patellofemoral stability in knees with trochlear dysplasia. We created and exploited a range of finite element models to address this gap in knowledge.

METHODS

MRI data of 5 knees with trochlear dysplasia and symptomatic patellofemoral instability were adapted into this previously established model. Vastus medialis obliquus strengthening as well as double-bundle medial patellofemoral ligament reconstruction and the combination of medial patellofemoral ligament reconstruction and trochleoplasty were simulated. The force necessary to dislocate the patella by 10 mm and fully dislocate the patella was calculated in different flexion angles.

FINDINGS

Our model predicts a significant increase of patellofemoral stability at the investigated flexion angles (0°-45°) for a dislocation of 10 mm and a full dislocation after medial patellofemoral ligament reconstruction and the combination of medial patellofemoral ligament reconstruction and trochleoplasty compared to trochleodysplastic (P = 0.01) and healthy knees (P = 0.01-0.02). Vastus medialis obliquus strengthening has a negligible effect on patellofemoral stability.

INTERPRETATIONS

This is the first objective quantitative biomechanical evidence supporting the place of medial patellofemoral ligament reconstruction and medial patellofemoral ligament reconstruction combined with trochleoplasty in patients with symptomatic patellofemoral instability and trochlear dysplasia type B. Vastus medialis obliquus strengthening has a negligible effect on patellar stability at a low total quadriceps load of 175 N.

Patellar stabilization surgeries in cases of recurrent patellar instability: a retrospective clinical and radiological audit

BACKGROUND

Patellar instability is a disabling condition that limits the functional ability and physical aspirations of patients. There are multiple anatomical structures which stabilize the patella and surgical treatment is tailored to repair the underlying aetiology.

AIMS

To evaluate the clinical and radiological outcome of patellar stabilization procedures in patients with recurrent patellar instability.

METHODS

We analysed 34 patients (36 knees) (mean age, 26.6) with recurrent patellar instability who underwent patellar stabilization surgery from June 2009 to September 2014. Type of procedure was dependent on the concomitant aetiological factors; tibial tuberosity osteotomy (61.76%), medial patellofemoral ligament reconstruction (67.64%), lateral release (5.88%) and trochleoplasty (2.94%). Mean follow-up was 3 years (range 9 months-6 years).

RESULTS

At follow-up, 77% of patients were satisfied with the overall outcome of the procedure. The mean IKDC was 66.7, Lysholm 74.9. Mean patellar height decreased significantly (P < .05) to anatomical values. Pre-operatively, the mean tibial tuberosity-trochlear groove distance was 14.66 mm (55.6% at borderline/abnormal level) and 81% showed evidence of trochlear dysplasia. Complications were found in 3 patients (8.33%), 2 of which had further episodes of instability.

CONCLUSIONS

Patellar stabilization surgery is an effective method of treating patellar instability, resulting in stability of the knee in 94.4%. Despite this, patient dissatisfaction rates are quite high suggesting that this patient group, whilst mostly stable, remains significantly symptomatic from their knee. These positive results which are reflected in the recent literature represent a strong case for consideration of primary surgical stabilization in cases of patellar instability.

Development of a return to play checklist following patellar instability surgery: a Delphi-based consensus

PURPOSE

To date, there is no consensus for the appropriate timing or functional evaluation for safe return to play following patellar instability surgery. The purpose of this study is to develop a consensus-based return to play checklist following patellar stabilization surgery using the Delphi method.

METHODS

A 3-part survey series was conducted following the systematic guidelines of the Delphi technique for gathering consensus from experts in the management of patellofemoral instability. All surveys were completed between July and November of 2017. A literature search was performed in SCOPUS and PubMed to identify existing sources on return to play following patellar instability surgery and determining patellofemoral joint strength in athletes, which served as the basis for the surveys.

RESULTS

12 of the 19 selected participants (63%) completed the first-round survey, 11 of those 12 participants (92%) completed the second-round survey, and 10 of these 11 participants (91%) completed the final survey. Of the final ten participants, there was representation from seven different states in the USA. Nine of the ten (90%) respondents endorsed the final checklist. The final checklist included eight overarching domains with defined and reproducible objective criteria.

CONCLUSION

The standardized list of objective and reproducible criteria for rehabilitation outlined below should help practitioners focus more on patient-centred factors and less on arbitrary timelines. No prior study has gathered consensus from experts on this topic; therefore, this study should serve as a benchmark to help guide patients back to sport safely.

LEVEL OF EVIDENCE

V.

Self-reported and performance-based outcomes following medial patellofemoral ligament reconstruction indicate successful improvements in knee stability after surgery despite remaining limitations in knee function

PURPOSE

To evaluate short- to midterm outcomes of medial patellofemoral ligament reconstruction (MPFL) using patient-reported outcome measures and functional testing.

METHODS

Twenty-four patients were examined regarding knee function after MPFL reconstruction, with a mean follow-up time of 45.3 ± 18.4 months since surgery. Knee function was evaluated using the Tegner score, VAS, the knee injury and osteoarthritis outcome score (KOOS), the Lysholm score, SF-36 and EQ-5D-3L as well as functional scores. A group of uninjured persons of the same age and same gender composition was used for comparison.

RESULTS

Eight (40%) patients managed to return to their pre-injury activity level. Five (25%) patients stated that they had experienced further patella dislocations after surgery but only two (10%) had sought medical help. Patients showed significantly poorer results in all PROMs compared to controls. The results obtained with SF-36 showed significant differences in physical health between the groups, but not in mental health. The functional performance test results showed overall poorer results for the patients versus controls: 11.5 sets for the square jump (6.7-15.7) versus 21 sets (18-26), 11.5 sets for the step-down test (6.5-15) versus 22 sets (18-26), and 77 cm for the single-leg hop for distance (32.2-110.5) versus 126 cm (115-37); all (P < 0.005).

CONCLUSIONS

After MPFL reconstruction, patients do not regain normal knee function, as measured by PROMs and functional tests, compared to an uninjured control group. Patients should be informed about residual functional limitations despite improved stability.

LEVEL OF EVIDENCE

III.

Management of the First Patellar Dislocation: A Narrative Review

First patellar dislocation is a common injury of the knee, involving often adolescents and the active population. The consequences of the first episode can be various and potentially disabling. Among these, acute patellar dislocation can often result in recurrent patellar instability. Recurrent patellar instability is certainly multifactorial but depends primarily on the injury of the medial patellofemoral ligament (MPFL), the major soft-tissue stabilizer of the patella. Some classifications are extremely useful in establishing the diagnosis and therapy in patellofemoral disease, in particular in terms of instability. Among those, Henri Dejour and WARPS (weak atraumatic risky anatomy pain and subluxation)/STAID (strong traumatic anatomy normal instability and dislocation) classifications are certainly the most frequently used. There is no clear agreement on the management of the first patellar dislocation. A conservative approach seems to be the first choice in most of cases, but the presence of patellar displacement or osteochondral fractures makes surgery mandatory at the beginning. In addition, there is no clear consensus on which surgical strategy should be used to approach first dislocation, in relation to the possible variation in location of the MPFL injury, and to the eventual presence of preexisting predisposing factors for patellar instability. MPFL reconstruction may theoretically be more reliable than repair, while there is no clear evidence available that osseous abnormality should be addressed after the first episode of patellar dislocation. A narrative review was conducted to report the etiology, the diagnosis and all the possible treatment options of the first patellar dislocation. Modern classifications of the patellofemoral instability were also presented.

Rehabilitation variability following medial patellofemoral ligament reconstruction

BACKGROUND

Medial patellofemoral ligament (MPFL) reconstruction is an increasingly utilized surgical option for recurrent patellar instability. Recent studies have highlighted the potential benefits of accelerated functional rehabilitation; however, no validated MPFL rehabilitation guidelines currently exist.

OBJECTIVE

To assess the variability of MPFL reconstruction rehabilitation protocols published online by academic orthopaedic programs.

METHODS

Online MPFL rehabilitation protocols from U.S. teaching orthopaedic programs were reviewed. A comprehensive scoring rubric was developed to assess each protocol for both the presence of various rehabilitation components and the timing of their introduction.

RESULTS

Thirty-one protocols (20%) were identified from 155 U.S. academic orthopaedic programs. Thirty protocols (97%) recommended immediate postoperative knee bracing. Twenty protocols (65%) allowed for weight-bearing as tolerated using crutches immediately postoperatively, whereas seven protocols (23%) recommended partial weight-bearing and four protocols (13%) recommended toe-touch weight-bearing. For those protocols advising partial and toe-touch weight-bearing, advancement to full weight-bearing was achieved at averages of 4.7 (range, 3-8) weeks and 6.3 (range, 6-7) weeks, respectively. There was considerable variation in range of motion (ROM) goals; however, most protocols (97%) recommended achieving 90 degrees of knee flexion at an average of 1.4 (range, 0-6) weeks. Significant diversity was found in the inclusion and timing of strengthening, stretching, proprioception, and basic cardiovascular exercises. Twenty-five protocols (81%) recommended return to training after completing specific athletic criteria.

CONCLUSIONS

A minority of U.S. teaching orthopaedic institutions publish MPFL reconstruction rehabilitation protocols online. Furthermore, there is a high degree of variability in both the composition and timing of rehabilitation modalities across these protocols.

Operative Versus Nonoperative Treatment After Acute Patellar Dislocation: Which Is More Effective at Reducing Recurrence in Adolescents?

Clinical Scenario: Acute patellar dislocations during adolescence often lead to future patellar instability. Two common treatment options include nonoperative treatment or operative repair of injured structures. Focused Clinical Question: In adolescents with acute patellar dislocation, how does operative stabilization compare with nonoperative treatment for reducing dislocation recurrence? Summary of Key Findings: Three studies were included: 2 randomized controlled trials and 1 nonrandomized study. All studies compared operative and nonoperative treatment outcomes in adolescents who experienced an acute patellar dislocation. Each study included nonoperative treatment such as patellar bracing and quadriceps strengthening. The operative treatments utilized in each study included lateral retinacular release and medial retinacular repair. All 3 of the studies included a follow-up of at least 6 years. Two of the studies concluded there to be no significant difference between treatment groups regarding redislocation rate, pain, and function. The third study reported a lower redislocation rate following operative treatment. Clinical Bottom Line: Reviewed evidence suggests that outcomes are similar when comparing operative and nonoperative treatment approaches with little agreement as to which is the optimal plan of action. Strength of Recommendation: One level II randomized controlled trial and a level III nonrandomized study suggest that patellar dislocation recurrence rates are similar among operative and nonoperative treatment approaches, while another level II randomized controlled trial suggests that an operative approach is superior.

Clinical Outcomes After the Nonoperative Management of Lateral Patellar Dislocations: A Systematic Review

Background:

The first-line treatment for patellar dislocations is often nonoperative and consists of physical therapy and immobilization techniques, with various adjuncts employed. However, the outcomes of nonoperative therapy are poorly described, and there is a lack of quality evidence to define the optimal intervention.

Purpose:

To perform a comprehensive review of the literature and assess the quality of studies presenting patient outcomes from nonoperative interventions for patellar dislocations.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

The MEDLINE, AMED, Embase, CINAHL, Cochrane Library, PEDro, and SPORTDiscus electronic databases were searched through July 2017 by 3 independent reviewers. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed. Study quality was assessed using the CONSORT (Consolidated Standards for Reporting Trials) criteria for randomized controlled trials and the Newcastle-Ottawa Scale for cohort studies and case series.

Results:

A total of 25 studies met our inclusion criteria, including 12 randomized controlled trials, 7 cohort studies, and 6 case series, consisting of 1066 patients. Studies were grouped according to 4 broad categories of nonoperative interventions based on immobilization, weightbearing status, quadriceps exercise type, and alternative therapies. The most commonly used outcome measure was the Kujala score, and the pooled redislocation rate was 31%.

Conclusion:

This systematic review found that patient-reported outcomes consistently improved after all methods of treatment but did not return to normal. Redislocation rates were high and close to the redislocation rates reported in natural history studies. There is a lack of quality evidence to advocate the use of any particular nonoperative technique for the treatment of patellar dislocations.

Recent developments in evaluation and treatment of lateral patellar instability

Recent years have been characterized by an ongoing increase in knowledge about the different conditions associated with lateral patellar instability. This increase in knowledge provides differentiated approaches to the various pathologies of the patellofemoral joint. Though current guidelines consider medial patellofemoral ligament (MPFL) reconstruction the basic treatment for the unstable patella, medial soft tissue-stabilizing procedures should not be interpreted as stand-alone procedures in every case. The influence of different anatomical factors leading to patellar instability, as well as their impact on clinical outcome measures, is becoming increasingly apparent and deserves further attention. Therefore, the purpose of this review was to summarize recent developments in lateral patellar instability beyond MPFL reconstruction techniques. For this goal, the literature published within the last 3 years considering all aspects of lateral patellar instability was analysed. Six main topics evolved according to the number of publications and in terms of novel aspects and recent developments in the evaluation and treatment of lateral patellar instability. Those topics formed the basis of this article: (1) treatment of first-time patellar dislocation, (2) the impact of trochlear dysplasia and trochleoplasty procedures, (3) the relevance of torsional deformities, (4) patellar instability in open physis, (5) the implementation of new outcome measures, and (6) rehabilitation after patellar stabilizing procedures.

I.S.Mu.L.T. first-time patellar dislocation guidelines

Primary traumatic patellar dislocation is common, particularly in young active individuals. A consensus on its management is still lacking. The present work provides easily accessible guidelines to be considered as recommendations for a good clinical practice developed through a process of systematic review of the literature and expert opinion, to improve the quality of care and rationalize the use of resources.

LEVEL OF EVIDENCE

Ia.

The development of an evidence-based clinical checklist for the diagnosis of anterior knee pain

Background

Anterior knee pain (AKP) or patellofemoral pain syndrome is common and may limit an individual’s ability to perform common activities of daily living such as stair climbing and prolonged sitting. The diagnosis is difficult as there are multiple definitions for this disorder and there are no accepted criteria for diagnosis. It is therefore most commonly a diagnosis that is made once other pathologies have been excluded.

Objectives

The aim of this study was to create an evidence-based checklist for researchers and clinicians to use for the diagnosis of AKP.

Methods

A systematic review was conducted in July 2016, and an evidence-based checklist was created based on the subjective and objective findings most commonly used to diagnose AKP. For the subjective factors, two or more of the systematic reviews needed to identify the factor as being important in the diagnosis of AKP.

Results

Two systematic reviews, consisting of nine different diagnostic studies, were identified by our search methods. Diagnosis of AKP is based on the area of pain, age, duration of symptoms, common aggravating factors, manual palpation and exclusion of other pathologies. Of the functional tests, squatting demonstrated the highest sensitivity. Other useful tests include pain during stair climbing and prolonged sitting. The cluster of two out of three positive tests for squatting, isometric quadriceps contraction and palpation of the patella borders and the patella tilt test were also recommended as useful tests to include in the clinical assessment.

Conclusion

A diagnostic checklist is useful as it provides a structured method for diagnosing AKP in a clinical setting. Research is needed to establish the causes of AKP as it is difficult to diagnose a condition with unknown aetiology.

Pediatric patellar dislocation

Acute patellar dislocation affects approximately 1:1000 healthy children 9-15 years of age, and up to 50% are at risk for recurrent dislocations. In adults the condition is associated with long-term complications, such as osteoarthritis and impairment of knee function. However, literature describing the outcome in a pediatric population is sparse. The present review article evaluates the long-term effects on knee function and cartilage quality after traumatic patellar dislocation in childhood, and also to evaluate the reliability of two clinical tests of medio-lateral knee position, in healthy children.

The patellofemoral pain and osteoarthritis subscale of the KOOS (KOOS-PF): development and validation using the COSMIN checklist

Background

Patellofemoral pain and osteoarthritis are prevalent and associated with substantial pain and functional impairments. Patient-reported outcome measures (PROMs) are recommended for research and clinical use, but no PROMs are specific for patellofemoral osteoarthritis, and existing PROMs for patellofemoral pain have methodological limitations. This study aimed to develop a new subscale of the Knee injury and Osteoarthritis Outcome Score for patellofemoral pain and osteoarthritis (KOOS-PF), and evaluate its measurement properties.

Methods

Items were generated using input from 50 patients with patellofemoral pain and/or osteoarthritis and 14 health and medical clinicians. Item reduction was performed using data from patellofemoral cohorts (n=138). We used the COnsesus-based Standards for the selection of health Measurements INstruments guidelines to evaluate reliability, validity, responsiveness and interpretability of the final version of KOOS-PF and other KOOS subscales.

Results

From an initial 80 generated items, the final subscale included 11 items. KOOS-PF items loaded predominantly on one factor, pain during activities that load the patellofemoral joint. KOOS-PF had good internal consistency (Cronbach’s α 0.86) and adequate test–retest reliability (intraclass correlation coefficient 0.86). Hypothesis testing supported convergent, divergent and known-groups validity. Responsiveness was confirmed, with KOOS-PF demonstrating a moderate correlation with Global Rating of Change scores (r 0.52) and large effect size (Cohen’s d 0.89). Minimal detectable change was 2.3 (groups) and 16 (individuals), while minimal important change was 16.4. There were no floor or ceiling effects.

Conclusions

The 11-item KOOS-PF, developed in consultation with patients and clinicians, demonstrated adequate measurement properties, and is recommended for clinical and research use in patients with patellofemoral pain and osteoarthritis.

Patellar dislocation: Not the bees knees

BACKGROUND

Patellar dislocations are common, particularly in the adolescent polulation. Registered Advanced Nurse Practitioners are healthcare professionals who can appropriately manage these injuries to minimise the risk of chronicity.

METHODS

This is a case study which uses a clinical examplar from the authors practice focusing on the assessment, diagnosis and managment of patellar dislocations. Particular reference is made of the significance of the MPFL.

RESULTS

This paper highlights the importance of recognition of appropriate management of patellar dislocations in the ED setting. Discussion points include the role of the MDT and the role of exercise prescription in the injury management.

CONCLUSION

The diagnosis of patellar dislocation is heavily dependant on eliciting a comprehensive history and conducting an appropriate clinical exam. Patient outcomes may be optimised by adopting an MDT approach.

The Norwich Patellar Instability Score: Validity, internal consistency and responsiveness for people conservatively-managed following first-time patellar dislocation

BACKGROUND

This paper assessed the validity, internal consistency, responsiveness and floor-ceiling effects of the Norwich Patellar Instability (NPI) Score for a cohort of conservatively managed people following first-time patellar dislocation (FTPD).

METHODS

Fifty patients were recruited, providing 130 completed datasets over 12 months. The NPI Score, Lysholm Knee Score, Tegner Level of Activity Score and isometric knee extension strength were assessed at baseline, six weeks, six and 12 months post-injury.

RESULTS

There was high convergent validity with a statistically significant correlation between the NPI Score and the Lysholm Knee Score (p<0.001), Tegner Level of Activity Score (p<0.001) and isometric knee extension strength (p<0.002). Principal component analysis revealed that the NPI Score demonstrated good concurrent validity with four components account for 70.4% of the variability. Whilst the NPI Score demonstrated a flooring-effect for 13 of the 19 items, no ceiling effect was reported. There was high internal consistency with a Cronbach Alpha value of 0.93 (95% CI: 0.91 to 0.93). The NPI Score was responsive to change over the 12 months period with an effect size of 1.04 from baseline to 12 months post-injury.

CONCLUSIONS

The NPI Score is a valid tool to assess patellar instability symptoms in people conservatively managed following FTPD.

LEVEL OF EVIDENCE

Level II.

Rehabilitation following first-time patellar dislocation: a randomised controlled trial of purported vastus medialis obliquus muscle versus general quadriceps strengthening exercises

BACKGROUND

We aimed to define whether distal vastus medialis (VM) muscle strengthening improves functional outcomes compared to general quadriceps muscle strengthening following first-time patellar dislocation (FTPD).

METHODS

Fifty patients post-FTPD were randomised to either a general quadriceps exercise or rehabilitation programme (n=25) or a specific-VM exercise and rehabilitation regime (n=25). The primary outcome was the Lysholm knee score, and secondary outcomes included the Tegner Level of Activity score, the Norwich Patellar Instability (NPI) score, and isometric knee extension strength at various knee flexion ranges of motion. Outcomes were assessed at baseline, six weeks, six months and 12months.

RESULTS

There were statistically significant differences in functional outcome and activity levels with the Lysholm knee score and Tegner Level of Activity score at 12months in the general quadriceps exercise group compared to the VM group (p=0.05; 95% confidence interval (CI): -14.0 to 0.0/p=0.04; 95% CI: -3.0 to 0.0). This did not reach a clinically important difference. There was no statistically significant difference between the groups for the NPI score and isometric strength at any follow-up interval. The trial experienced substantial participant attrition (52% at 12months).

CONCLUSIONS

Whilst there was a statistical difference in the Lysholm knee score and Tegner Level of Activity score between general quadriceps and VM exercise groups at 12months, this may not have necessarily been clinically important. This trial highlights that participant recruitment and retention are challenges which should be considered when designing future trials in this population.

LEVEL OF EVIDENCE

Therapeutic study, Level I.

Surgical versus non-surgical interventions for treating patellar dislocation

BACKGROUND

Patellar dislocation occurs when the patella disengages completely from the trochlear (femoral) groove. Following reduction of the dislocation, conservative (non-surgical) rehabilitation with physiotherapy may be used. Since recurrence of dislocation is common, some surgeons have advocated surgical intervention rather than non-surgical interventions. This is an update of a Cochrane review first published in 2011.

OBJECTIVES

To assess the effects (benefits and harms) of surgical versus non-surgical interventions for treating people with primary or recurrent patellar dislocation.

SEARCH METHODS

We searched the Cochrane Bone, Joint and Muscle Trauma Group's Specialised Register, the Cochrane Central Register of Controlled Trials (The Cochrane Library), MEDLINE, EMBASE, AMED, CINAHL, ZETOC, Physiotherapy Evidence Database (PEDro) and a variety of other literature databases and trial registries. Corresponding authors were contacted to identify additional studies. The last search was carried out in October 2014.

SELECTION CRITERIA

We included randomised and quasi-randomised controlled clinical trials evaluating surgical versus non-surgical interventions for treating lateral patellar dislocation.

DATA COLLECTION AND ANALYSIS

Two review authors independently examined titles and abstracts of each identified study to assess study eligibility, extract data and assess risk of bias. The primary outcomes we assessed were the frequency of recurrent dislocation, and validated patient-rated knee or physical function scores. We calculated risk ratios (RR) for dichotomous outcomes and mean differences MD) for continuous outcomes. When appropriate, we pooled data.

MAIN RESULTS

We included five randomised studies and one quasi-randomised study. These recruited a total of 344 people with primary (first-time) patellar dislocation. The mean ages in the individual studies ranged from 19.3 to 25.7 years, with four studies including children, mainly adolescents, as well as adults. Follow-up for the full study populations ranged from two to nine years across the six studies. The quality of the evidence is very low as assessed by GRADE (Grading of Recommendations Assessment, Development and Evaluation Working Group) criteria, with all studies being at high risk of performance and detection biases, relating to the lack of blinding.There was very low quality but consistent evidence that participants managed surgically had a significantly lower risk of recurrent dislocation following primary patellar dislocation at two to five years follow-up (21/162 versus 32/136; RR 0.53 favouring surgery, 95% confidence interval (CI) 0.33 to 0.87; five studies, 294 participants). Based on an illustrative risk of recurrent dislocation in 222 people per 1000 in the non-surgical group, these data equate to 104 fewer (95% CI 149 fewer to 28 fewer) people per 1000 having recurrent dislocation after surgery. Similarly, there is evidence of a lower risk of recurrent dislocation after surgery at six to nine years (RR 0.67 favouring surgery, 95% CI 0.42 to 1.08; two studies, 165 participants), but a small increase cannot be ruled out. Based on an illustrative risk of recurrent dislocation in 336 people per 1000 in the non-surgical group, these data equate to 110 fewer (95% CI 195 fewer to 27 more) people per 1000 having recurrent dislocation after surgery.The very low quality evidence available from single trials only for four validated patient-rated knee and physical function scores (the Tegner activity scale, KOOS, Lysholm and Hughston VAS (visual analogue scale) score) did not show significant differences between the two treatment groups.The results for the Kujala patellofemoral disorders score (0 to 100: best outcome) differed in direction of effect at two to five years follow-up, which favoured the surgery group (MD 13.93 points higher, 95% CI 5.33 points higher to 22.53 points higher; four studies, 171 participants) and the six to nine years follow-up, which favoured the non-surgical treatment group (MD 3.25 points lower, 95% CI 10.61 points lower to 4.11 points higher; two studies, 167 participants). However, only the two to five years follow-up included the clear possibility of a clinically important effect (putative minimal clinically important difference for this outcome is 10 points).Adverse effects of treatment were reported in one trial only; all four major complications were attributed to the surgical treatment group. Slightly more people in the surgery group had subsequent surgery six to nine years after their primary dislocation (20/87 versus 16/78; RR 1.06, 95% CI 0.59 to 1.89, two studies, 165 participants). Based on an illustrative risk of subsequent surgery in 186 people per 1000 in the non-surgical group, these data equate to 11 more (95% CI 76 fewer to 171 more) people per 1000 having subsequent surgery after primary surgery.

AUTHORS' CONCLUSIONS

Although there is some evidence to support surgical over non-surgical management of primary patellar dislocation in the short term, the quality of this evidence is very low because of the high risk of bias and the imprecision in the effect estimates. We are therefore very uncertain about the estimate of effect. No trials examined people with recurrent patellar dislocation. Adequately powered, multi-centre, randomised controlled trials, conducted and reported to contemporary standards, are needed. To inform the design and conduct of these trials, expert consensus should be achieved on the minimal description of both surgical and non-surgical interventions, and the anatomical or pathological variations that may be relevant to both choice of these interventions and the natural history of patellar instability. Furthermore, well-designed studies recording adverse events and long-term outcomes are needed.

Acute traumatic patellar dislocation

Inaugural traumatic patellar dislocation is most often due to trauma sustained during physical or sports activity. Two-thirds of acute patellar dislocations occur in young active patients (less than 20 years old). Non-contact knee sprain in flexion and valgus is the leading mechanism in patellar dislocation, accounting for as many as 93% of all cases. The strong displacement of the patella tears the medial stabilizing structures, and notably the medial patellofemoral ligament (MPFL), which is almost always injured in acute patellar dislocation, most frequently at its femoral attachment. Lateral patellar glide can be assessed with the knee in extension or 20° flexion. Displacement by more than 50% of the patellar width is considered abnormal and may induce apprehension. Plain X-ray and CT are mandatory to diagnose bony risk factors for patellar dislocation, such as trochlear dysplasia or increased tibial tubercle-trochlear groove distance (TT-TG), and plan correction. MRI gives information on cartilage and capsulo-ligamentous status for treatment planning: free bodies or osteochondral fracture have to be treated surgically. If patellar dislocation occurs in an anatomically normal knee and osteochondral fracture is ruled out on MRI, non-operative treatment is usually recommended.

Operative versus conservative treatment for patellar dislocation: a meta-analysis of 7 randomized controlled trials

Purpose

Patellofemoral pathology is common, and patellofemoral dislocation mainly affects adolescents and young adults. We conducted a meta-analysis exclusively of RCTs to compare the clinical outcomes of patellar dislocation patients managed operatively versus non-operatively.

Methods

After systematic review of electronic databases and websites, a total of 7 RCTs reporting data on 402 subjects were included. The methodological quality of the literature was assessed using the PEDro critical appraisal tool. Mean differences (MDs) and risk ratio (RR) were calculated for the pooled effects. Heterogeneity was assessed using the I² test.

Results

Data synthesis showed a lower rate of recurrent patellar dislocation post-treatment in patients managed operatively compared to non-operatively (P = 0.01).

Conclusion

The results suggest a difference in outcomes between the treatment strategies. However the limited number of studies and high risk of inherent bias indicate that future studies involving more patients in better-designed randomized controlled trials will be required.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/8011948721221355.

Return to sport after patellar dislocation or following surgery for patellofemoral instability

Patellofemoral instability may occur in a young population as a result of injury during sporting activities. This review focuses on return to sport after one episode of dislocation treated no operatively and as well after surgery for chronic patellofemoral instability. With or without surgery, only two-thirds of patients return to sports at the same level as prior to injury. A high-quality rehabilitation programme using specific exercises is the key for a safe return to sporting activities. To achieve this goal, recovery of muscle strength and dynamic stability of the lower limbs is crucial. The focus should be directed to strengthen the quadriceps muscle and pelvic stabilizers, as well as lateral trunk muscle training. Patient education and regularly performed home exercises are other key factors that can lead to a successful return to sports. The criteria for a safe return to sports include the absence of pain, no effusion, a complete range of motion, almost symmetrical strength, and excellent dynamic stability. Level of evidence IV.

The contemporary management of anterior knee pain and patellofemoral instability

In this review the evidence for the management of patients with patellofemoral disorders is presented confined to anterior knee pain and patellar dislocation (excluding patellofemoral arthritis). Patients present along a spectrum of these two problems and are best managed with both problems considered. The key to managing these patients is by improving muscle function, the patient losing weight (if overweight), and judicious use of analgesics if pain is an important feature. Hypermobility syndrome should always be looked for since this is a prognostic indicator for a poor operative outcome. Operations should be reserved for those with correctable anatomical abnormalities that have failed conservative therapy. The current dominant operation is a medial patellofemoral ligament reconstruction.

First-time patellar dislocation: surgery or conservative treatment?

Primary patellar dislocation injures the medial patellofemoral ligament (MPFL), the major soft-tissue stabilizer of the patella, which may lead to recurrent patellar instability. Recurrent patellar dislocation are common and may require surgical intervention. The variation in location of injury of the MPFL and the presence of an osteochondral fracture produces challenges in clinical decision making between nonoperative and operative treatment, including the surgical modality, to repair or reconstruct the MPFL. Current evidence suggests that not all primary dislocations should undergo the same treatment. MPFL reconstruction may theoretically be more reliable than repair, but the optimal time to perform additional bony corrections is not known. A normal or minor dysplastic patellofemoral joint may be suitable for nonoperative treatment, whereas a higher grade of trochlear dysplasia or other significant abnormalities may benefit from surgical treatment. In this paper, we present a treatment algorithm for primary patellar dislocation.

Lateral release and medial plication for recurrent patella dislocation

PURPOSE

This study aims to report the long-term results of lateral release and medial plication in patients with recurrent patellar dislocation.

METHODS

In this study, 31 patients who underwent surgery for recurrent patellar dislocation were retrospectively reviewed between 1994 and 2004. Among the 31 patients were 12 male and 19 female patients. The average age was 23.9 ± 4.8 years, and the mean follow-up period was 11.6 ± 2.4 years.

RESULTS

Three patients had postoperative dislocations. The mean Kujala score significantly improved from 57.5 ± 13.2 points preoperatively to 89.2 ± 8.7 points at the final follow-up (P < 0.0001). The median Tegner activity score significantly improved from 3 (range, 1-5) at preoperative examination to 7 (range, 3-9) at the final follow-up (P < 0.0001). Ten patients were rated as excellent, 18 as good, 2 as fair, and 1 as poor. The congruence angle improved from 16.5° ± 3.0° to -2.8° ± 2.7°, and the lateral patellofemoral angle improved from -4.2° ± 1.9° to 8.2° ± 2.5°. There was no case of osteoarthritis at the final follow-up.

CONCLUSIONS

Percutaneous lateral release and medial plication showed satisfactory results with limited morbidity in the long-term follow-up. This traditional method remains a simple and effective surgical procedure for recurrent patellar dislocation.

LEVEL OF EVIDENCE

Therapeutic, Level IV.

A feasibility study for a pragmatic randomised controlled trial comparing cast immobilisation versus no immobilisation for patients following first-time patellar dislocation

BACKGROUND

The purpose of this feasibility study was to begin to determine the efficacy of cylinder cast immobilisation compared to no form of immobilisation for patients following first-time patellar dislocation (FTPD).

MATERIALS AND METHODS

Participants were patients who attended a National Health Service Accident and Emergency department following a FTPD. Patients were randomised to receive immobilisation for four weeks in a cylinder cast followed by rehabilitation, versus no immobilisation and early rehabilitation. All patients were followed-up over a three month period, assessed using the Visual analogue scale for pain, Short Form-36, the Lysholm knee score and the Modified Functional Index.

RESULTS

Forty-one patients were approached to participate. Eight satisfied the pre-defined eligibility criteria and were randomised between the two groups. Whilst the results indicated a trend for superior short-term functional outcomes for those patients not immobilised compared to those immobilised following a FTPD, the small sample and baseline imbalances between the groups may have had a substantial influence on the results.

CONCLUSION

This feasibility study has indicated that the outcome measurements adopted were appropriate to answer this research question, but the assessment of return to normal activity, recurrent instability and dislocation and cost-effectiveness over a longer follow-up period is recommended. Similarly, defining a more pragmatic eligibility criteria and recruiting from multiple centres would be recommended for the definitive trial requiring a sample of 348 patients to demonstrate a statistical significant treatment effect.

Surgical versus non-surgical interventions for treating patellar dislocation

BACKGROUND

Patellar dislocation occurs when the patella disengages completely from the trochlear (femoral) groove. Following reduction of the dislocation, conservative rehabilitation with physiotherapy may be used. Since recurrence of dislocation is common, some surgeons have advocated surgical intervention in addition to rehabilitation.

OBJECTIVES

The purpose of this review was to assess the clinical and radiological outcomes of surgical, compared with non-surgical, interventions for treating people with primary or recurrent patellar dislocation.

SEARCH METHODS

We searched the Cochrane Bone, Joint and Muscle Trauma Group's Specialised Register, the Cochrane Central Register of Controlled Trials (The Cochrane Library), MEDLINE, EMBASE, AMED, CINAHL, ZETOC, Physiotherapy Evidence Database (PEDro), and a variety of other literature databases and trial registries. Corresponding authors were contacted to identify additional studies. Date searched: August 2010.

SELECTION CRITERIA

Eligible for inclusion were randomised and quasi-randomised controlled clinical trials evaluating surgical versus non-surgical interventions for treating lateral patellar dislocation.

DATA COLLECTION AND ANALYSIS

Two reviewers independently examined titles and abstracts of each identified study to assess study eligibility, extract data and assess risk of bias. Primary outcomes assessed were the frequency of recurrent dislocation, and validated patient-rated knee or physical function scores. When appropriate, data were pooled. Risk ratios were calculated for dichotomous outcomes, and mean differences for continuous outcomes.

MAIN RESULTS

Five studies (339 participants) were included. All studies had methodological shortcomings, especially the two quasi-randomised trials that presented a high risk for selection bias. Follow-up was a minimum of two years in two studies and between five and seven years in three studies. There was no significant difference between surgical and non-surgical management of primary (first-time) patellar dislocation in the risk of recurrent dislocation (47/182 versus 53/157; risk ratio 0.81, 95% confidence interval 0.56 to 1.17; 5 trials), Kujala patellofemoral disorder scores (mean difference 3.13, 95% confidence interval -7.34 to 13.59; 5 trials) nor the requirement for subsequent surgery (risk ratio 1.09, 95% CI 0.72 to 1.65; 3 trials). Adverse events were reported by one trial, citing four major complications that occurred in the surgical group. No randomised controlled trials have assessed populations with recurrent patellar dislocation.

AUTHORS' CONCLUSIONS

There is insufficient high quality evidence to confirm any significant difference in outcome between surgical or non-surgical initial management of people following primary patellar dislocation, and none examining this comparison in people with recurrent patellar dislocation. Adequately powered randomised, multi-centre controlled trials, conducted and reported to contemporary standards are recommended.

[Treatment of patellar instability in children and adolescents]

To address recurrent patellar instability in children and young adolescents a variety of therapeutic options exist either as non-operative or operative treatment. Recent options, such as reconstruction of the medial patellofemoral ligament have evoked a new focus of attention on this topic. The intention of this article is to present diverse therapeutic options and to evaluate them by reference to the current literature.

Operative versus non-operative management of patellar dislocation. A meta-analysis

PURPOSE

Conservative management of patellar dislocation can result in recurrent instability in up to 60% of patients. Surgery is therefore advocated in an attempt to reduce the incidence of recurrent dislocation and instability. The purpose of this study was to compare the clinical outcomes of operative to non-operative treatment strategies for patients following patellar dislocation.

METHODS

A systematic review of published and unpublished literature was undertaken. Following data extraction, a meta-analysis was conducted to compare the two treatment strategies. The methodological quality of the literature was assessed using the PEDro critical appraisal tool.

RESULTS

Eleven studies were included, five randomised controlled trials (RCTs) and six non-RCTs. These assessed 403 patients managed conservatively, compared to 344 managed surgically. The findings of this study indicate that operative management of patellar dislocation is associated with a significantly higher risk of patellofemoral joint osteoarthritis (P=0.04), but a significantly lower risk of subsequent patellar dislocation compared to non-surgical management (P<0.01).

CONCLUSIONS

The meta-analysis indicates that there may be a difference in the incidence of patellofemoral joint osteoarthritis and rate of subsequent dislocation. However, this finding should currently be interpreted with great caution due to the demonstration of statistically significant publication bias, issues related to the methodological quality of the evidence base, and due to the variety of different surgical interventions currently presented within the literature.

LEVEL OF EVIDENCE

III.

A national survey of the physiotherapy management of patients following first-time patellar dislocation

OBJECTIVES

The purpose of this study was to determine how musculoskeletal physiotherapists in acute National Health Service (NHS) hospitals manage patients following a first time patellar dislocation.

DESIGN

National survey study.

SETTING

All NHS acute hospitals with an accident and emergency and/or an orthopaedic department were surveyed.

PARTICIPANTS

306 institutions were surveyed.

INTERVENTIONS

Each institution was sent a 14 question self-administered questionnaire pertaining to the assessment, treatment, evaluation and outcome of patients following a first time patellar dislocation. After 3 weeks, all non-respondents were sent a reminder letter. After a further 3 weeks, those who had not responded by this time were sent a final reminder and copy of the questionnaire.

RESULTS

The survey response rate was 59%. The respondents indicated that first-time patellar dislocation was not a common musculoskeletal disorder managed by NHS physiotherapists, constituting an average of 2% of caseloads. The results suggested that physiotherapists most commonly assess for reduced quadriceps or VMO capacity, gait, patellar tracking and glide, and knee effusion when examining patients following a first-time patellar dislocation. The most common treatments adopted are reassurance, behaviour modification followed by proprioceptive, knee mobility, quadriceps and specific VMO exercises.

CONCLUSIONS

Generic lower limb assessment and treatment strategies are widely used to manage this patient group. Given the previous paucity in this literature, further study is now recommended to assess the efficacy of these interventions to provide UK physiotherapists with an evidence-base to justify their management strategies.