Open lateral retinacular closure surgery for treatment of anterolateral knee pain and disability after arthroscopic lateral retinacular release

Patellofemoral instability part 1 (When to operate and soft tissue procedures): State of the art

Patellofemoral instability is usually initially treated non-operatively. Surgery is considered in patients with recurrent patellar dislocation and after a first-time patellar dislocation in the presence of either an associated osteochondral fracture or high risk of recurrence. Stratifying the risk of recurrence includes evaluating risk factors such as age, trochlear dysplasia, contralateral dislocation, and patellar height. Surgery with soft tissue procedures includes restoring the medial patellar restraints and balancing the lateral side of the joint. Reconstruction of the medial patellofemoral ligament is the most frequent way of addressing the medial soft tissues in patients with patellofemoral instability. Meanwhile, lateral tightness can be achieved by lateral retinaculum lengthening or release. Approaching patellofemoral instability in a patient-specific approach, combined with a shared decision-making process with the patient/family, will guide surgeons to the deliver optimal care for the patellar instability patient.

Is the patella apprehension test a valid diagnostic test for patellar instability? A systematic review

Introduction

Patellar instability can arise from a traumatic event with anatomical predisposing factors increasing the risk of dislocation. Accurate diagnosis is required to initiate appropriate treatment. We aimed to evaluate the patella apprehension test (PAT) as a method to diagnose patellar instability.

Methods

The PRISMA diagnostic test accuracy checklist was followed. The review protocol was registered on PROSPERO with registration number CRD42022357898. Electronic databases, currently registered studies, conference proceedings and the reference lists of included studies were searched. A narrative synthesis evaluated the validity of the PAT as a method of diagnosing patellar instability.

Results

A total of 4867 records were screened in the initial search. Of these, 34 articles satisfied the inclusion criteria, assessing 1139 knees of 1046 patients. The PAT was found to have a high sensitivity and specificity. Its intra and inter-rater reliability was highly variable among studies. Studies reporting patellar instability correction following surgery also found a decrease in the number of patients exhibiting a positive PAT.

Conclusion

Current evidence suggests that the PAT has a high sensitivity and specificity. The intra- and inter-rater validities of the PAT are widely variable due to its subjective nature. Thus, though the PAT can be used to provide a provisional clinical diagnosis of patellar instability, formal functional assessment and imaging should be performed to confirm the diagnosis. Further research should explore the association between a positive PAT and anatomical parameters. In addition, studies comparing the accuracy of the PAT and radiological investigations should be performed.

Lateral Patellofemoral Ligament Reconstruction: A Biomechanical Comparison of 2 Techniques

BACKGROUND

The importance of maintaining lateral patellar stabilizing structures has been demonstrated by the presence of iatrogenic medial patellar instability after lateral retinacular release (LRR) procedures. In patients with medial patellar instability, lateral patellofemoral ligament (LPFL) reconstruction has been clinically shown to restore patellar stability while improving patient-reported outcomes. However, the biomechanics associated with different LPFL reconstruction techniques remain largely unknown.

PURPOSE

To (1) investigate whether LPFL reconstruction restores medial patellar translation compared with the intact state after LRR and (2) evaluate for any biomechanical differences between soft tissue and osseous LPFL reconstruction techniques.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 7 knees were included in the final analysis. The knees were dissected, and the tibia and femur were potted. An eye screw was then placed at the midpoint of the patella perpendicular to the medial surface. A custom jig was constructed to allow for a 1-kg load to be applied to the quadriceps muscle. Medial patellar displacement was investigated at 0°, 10°, 20°, 30°, 45°, 60°, and 90° of knee flexion using a tensile testing machine with a 20-N medial force applied to the patella. Medial patellar displacement was assessed in 4 states: intact, LRR, soft tissue LPFL reconstruction (inserted through incisions in the iliotibial band, quadriceps tendon, and patellar tendon), and osseous LPFL reconstruction.

RESULTS

The LRR group had significantly greater medial patellar translation compared with the intact group throughout flexion (P < .01 to P = .029). The soft tissue LPFL reconstruction group demonstrated significantly greater medial patellar translation at 30° (P = .020) and 45° (P = .025) compared with the intact group, with less translation compared with the LRR group at all degrees of knee flexion except for 45° (P = .065). The osseous LPFL reconstruction group demonstrated significantly greater medial patellar translation compared with the intact group at 30° of flexion (P = .036), with significantly less translation compared with the LRR group from 0° to 30° (P < .01 to P = .013). The soft tissue LPFL reconstruction group (15.94 ± 2.55 mm) demonstrated significantly greater medial patellar translation at 10° of flexion compared with the osseous LPFL reconstruction group (14.16 ± 2.34 mm) (P = .033).

CONCLUSION

Soft tissue LPFL reconstruction led to significantly greater medial patellar translation at 30° and 45° compared with the intact state, while osseous LPFL reconstruction produced significantly greater translation only at 30°. Both the soft tissue and the osseous reconstruction techniques resulted in comparable medial patellar translation at all degrees of knee flexion except for 10°, in which osseous reconstruction was more similar to the intact state.

CLINICAL RELEVANCE

Compared with LRR, soft tissue LPFL reconstruction was able to restore stability against medial patellar translation at most degrees of knee flexion, while osseous LPFL reconstruction did not provide adequate stabilization beyond 30° of flexion. While the LPFL does appear to have osseous insertions, soft tissue reconstruction functioned more similarly to the intact state after LRR.

Trends in Lateral Retinacular Release from 2010 to 2017

Historically, lateral retinacular release (LRR) procedures have been utilized in the treatment of a variety of patellofemoral disorders, including lateral patellar instability. However, in the past decade, there has been an increasing awareness of the importance of the lateral stabilizers in patellar stability, as well as the complications of LRR, such as recurrent medial patellar instability. The purpose of this study was to investigate current trends in LRR procedures from 2010 through 2017 using a large national database. The American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) database was queried for arthroscopic LRR procedures (the Current Procedural Terminology [CPT] code, 29873) from 2010 to 2017. The number and incidence of lateral release procedures, both isolated and nonisolated, were analyzed and separated into cohorts for analysis. Age and gender of the LRR cohort was investigated and compared with all other orthopaedic procedures during the same time period in the NSQIP database. In addition, concomitant procedures and associated International Classification of Disease-9th Revision (ICD-9) and ICD-10th Revision (ICD-10) codes were analyzed over time and between LRR groups. From 2010 to 2017, 3,117 arthroscopic LRRs were performed. The incidence for LRR was 481.9 per 100,000 orthopaedic surgeries in 2010 and significantly decreased to 186.9 per 100,000 orthopaedic surgeries in 2017 (p < 0.01). LRR was more commonly performed in females (66%) and 58% of patients were under 44 years of age. In addition, LRR was most commonly performed with a concomitant meniscectomy (36%), synovectomy (19%), or microfracture (13%), and for a diagnosis of pain (22%). The overall incidence of LRR procedures significantly decreased from 2010 to 2017. LRRs were more commonly performed in younger, female patients for a diagnosis of pain with the most common concomitant procedure being meniscectomy, synovectomy, or microfracture.

Comparison of Clinical and Radiological Results of Lateral Retinacular Release or Lateral Retinacular Lengthening Methods Combined With Medial Retinaculum Plication in Patellofemoral Instability

Introduction

In this study, we aimed to compare the clinical and radiological results of patients who underwent medial retinaculum plication (MRP) combined with lateral retinacular release (LRR) or lateral retinacular lengthening (LRL) with the diagnosis of patellofemoral (PF) instability.

Methods

In our study, we retrospectively analyzed 75 knees of 75 adult patients (43 females and 32 males) who underwent MRP+LRR or MRP+LRL due to PF instability without osseous pathologies. Patients were divided into two groups (MRP+LRR and MRP+LRL) according to the surgical method. The clinical and radiological results of the two groups were compared.

Results

MRP+LRL surgery was performed on 45 knees and MRP+LRR surgery on 30 knees. The mean age was 26.5 (18-43) years. There was no significant difference between the two groups in the change in patellar lateral shift (PLS) (p=0.429) and congruence angle (CA) (p=0.218) values. However, there was a significant difference between the two groups in the change in patellar tilt angle (PTA) (p=0.009) and lateral patellofemoral angle (LPFA) (p<0.001) values. The change in PTA and LPFA values was higher in the MRP+LRL group. There was no significant difference between the two groups in terms of pre-operative and post-operative Lysholm knee scoring scale (p=0.205, p=0.228), Kujala pain scale (p=0.393, p=0.596), and Tegner activity level scale values (p=0.121, p=0.899).

Conclusions

MRP+LRR or MRP+LRL provided successful results for correcting the instability in PF instability without osseous pathologies such as patella alta, tibial tubercle-trochlear groove (TT-TG) dysplasia, trochlea dysplasia, genu valgus, and tibial-femoral torsion. While PTA and LPFA values improved more with the MRP-LRL method, clinical results were similar in both methods.

Bilateral Medial and Lateral Patellofemoral Ligament Reconstruction in a Patient with Hypermobility Type Ehlers-Danlos Syndrome: A Case Report

CASE

Medial patellar instability (MPI) is a known sequela of previous lateral retinacular release. Literature on surgical intervention is scarce. We present a case of a 35-year-old woman with hypermobility type Ehlers-Danlos syndrome, with bilateral iatrogenic MPI (IMPI) and lateral patellar instability. This condition led to a marked decrease in quality of life, 10/10 persistent pain, and frequent dislocation events. She was successfully treated surgically, and at 2 years had 0/10 pain and no further dislocations.

CONCLUSIONS

Our technique for medial and lateral patellofemoral ligament reconstruction is a viable intervention for patients with IMPI, even in the setting of underlying collagen disorder.

Treatment for lateral patellar impingement syndrome with arthroscopic lateral patelloplasty: a bidirectional cohort study

Background

Anterior knee pain is one of the most common musculoskeletal complaints of young patients. We notice that some patients had normal femoral trochlear, medial and lateral patellar retinaculum, and special patellar morphology, which resulted in a series of symptoms in the flexion of the knee due to the impingement of the lateral articular surface of the patella with the femur. We firstly termed this pathologic process as lateral patellar impingement syndrome (LPIS). This ambispective cohort study was to explore the curative effect of arthroscopic lateral patelloplasty for early LPIS.

Methods

Thirty-five early LPIS patients which underwent arthroscopic lateral patelloplasty were enrolled in our study. Evaluations consisted of pre- and postoperative symptoms, physical examinations, radiographs, and questionnaires. The Lysholm score, patellar suitable angle, patellar tilt angle, and patellar lateral shift were measured with the CT scan and Merchant X-ray film. The efficacy was graded as excellent, good, fair, and poor according to the patient’s subjective evaluation.

Results

The patients were followed up for an average of 41.1 ± 18.6 months. The efficacy results were excellent in 6, good in 26, fair in 2, and poor in 1. There were statistical differences in pre- and postoperative Lysholm scores (80.66 ± 5.51 vs 81.91 ± 6.21) (P < 0.05). The pre- and postoperative congruence angle, patellar tilt angle, and patellar lateral shift were significantly different (P < 0.05).

Conclusions

Arthroscopic lateral patelloplasty is an effective and minimal-invasive method for patients with lateral patellar impingement syndrome.

Medial Patellar Instability: A Systematic Review of the Literature of Outcomes After Surgical Treatment

PURPOSE

To perform a systematic review of literature reporting on outcomes after surgical treatment of medial patellar instability.

METHODS

A systematic review was performed according to PRISMA guidelines. Inclusion criteria were as follows: the outcomes and complications of medial patellar instability repair with a follow-up greater than 12 months, English language, and human studies. We excluded cadaveric studies, animal studies, basic science articles, editorial articles, review articles, and surveys.

RESULTS

Searches identified 1,116 individual titles. After inclusion and exclusion criteria were applied, a total of 8 studies were identified. Three studies exclusively included patients with previous lateral release; 1 included patients with chronic instability; 1 included patients with both previous lateral release and other surgical causes; 1 study had patients with previous lateral release, spontaneous instability, and instability due to injury; 1 study included patients after tibial tubercle transfer surgery; and 1 study did not report the etiology of instability.

CONCLUSIONS

Good to excellent outcomes were reported postoperatively in 85% of the patients after surgical treatment of medial patellar instability. However, clinical outcomes data for medial patellar ligament reconstruction is sparse and highly heterogeneous. There is inconsistency in the literature in regard to the indication, timing, and procedure.

LEVEL OF EVIDENCE

Level IV, systematic review of Level IV studies.

Arthroscopic Lateral Retinacular Release in Adolescents With Medial Patellofemoral Ligament-centered Knee Pain

BACKGROUND

The medial patellofemoral ligament (MPFL) has been implicated as a common pain generator in adolescents with anterior knee pain. The purpose of this study is to report the clinical outcomes of arthroscopic lateral retinacular release (ALRR) for refractory MPFL-centered pain and to identify risk factors for poor outcomes and surgical failures.

METHODS

A single-surgeon database was queried to identify all patients undergoing ALRR. Inclusion criteria included minimum 12-month follow-up and ALRR performed for MPFL pain rather than for generalized anterior knee pain or patellar instability. All patients had persistent MPFL-centered pain despite participating in a nonsurgical protocol before surgery. Primary outcomes included International Knee Documentation Committee (IKDC) subjective score and need for further surgery, typically tibial tubercle osteotomy (TTO).

RESULTS

Eighty-eight knees in 71 patients [66 female, 5 male; average age, 15.7 y (range, 8.4 to 20.2 y)] were included. Average follow-up was 59 months (range, 12 to 138 mo). Average preoperative IKDC score was 41.9 (range, 18.4 to 67.8), whereas average postoperative IKDC score was 77.8 (range, 11.5 to 98.9; P<0.01). Postoperative IKDC scores were worse in patients with a preoperative sulcus angle of <134 degrees than those with sulcus angle of ≥134 degrees (69.9±22.1 vs. 82.0±12.5, P=0.04). Lower preoperative IKDC score correlated negatively with improvement of IKDC score postoperatively (r=-0.40, P<0.05). Seventeen knees (19.3%) subsequently underwent TTO for persistent symptoms. Patients who ultimately required TTO were younger than patients who did not (14.8±1.5 vs. 15.9±2.1; P=0.04) and had lower mean preoperative Blackburne-Peel ratio (0.95±0.25 vs. 1.11±0.24; P=0.02).

CONCLUSIONS

This study demonstrates that patients with refractory MPFL-centered knee pain had significant improvements in clinical outcomes after undergoing ALRR at mean 5 years' follow-up. Poor outcomes and surgical failures were associated with lower preoperative IKDC score, younger age, lower preoperative Blackburne-Peel ratio, and sulcus angle of <134 degrees. Outcomes were not recorded prospectively, but mean IKDC scores <60 months postoperatively were similar to those collected ≥60 months after surgery (80.4 vs. 78.3, P=0.15).

LEVEL OF EVIDENCE

Level IV.

Iatrogenic medial patellar instability following lateral retinacular release of the knee joint

PURPOSE

Iatrogenic medial patellar instability (IMPI) is a disabling but easily missed condition that is most often seen as a late complication of lateral retinacular release (LRR) procedures. The purposes of this study were (1) to summarize the available diagnostic methods and (2) to explore the contributing factors of IMPI following LRR procedures.

METHODS

The MEDLINE, PubMed, EMBASE and Cochrane Library databases were searched for studies including diagnosed IMPI cases following LRR procedures. All patients were first divided into IMPI group and non-IMPI group based on the diagnostic methods of IMPI collected from studies. Univariate analysis was performed by comparing the two groups with regard to individual patient data (age at initial LRR, gender) and surgical details (type, releasing scope, combined surgeries and indication) of LRR procedures. Multivariate logistic regression was carried out to identify independent contributing factors for IMPI and to calculate odds ratios (ORs).

RESULTS

Eight studies with 274 patients (300 knees) were finally included. Of those, 161 patients (171 knees, 57.0 %) had IMPI and 113 patients (129 knees, 43.0 %) had no IMPI. Univariate analysis revealed a statistically significant difference between both groups for releasing scope (P 1 < 0.001) and indication of LRR procedures (P 2 < 0.001), with releasing lateral retinaculum (LR) + vastus lateralis (VL) tendon and absence of tight LR during the initial LRR procedures being more common in patients with IMPI. The independent contributing factors for IMPI identified in the multivariate logistic regression analysis were releasing LR + VL (OR1 = 16.49) and absence of tight LR (OR2 = 14.37).

CONCLUSIONS

The IMPI was more common in patient with an over-released LRR and patient who was absent of tight LR during the initial LRR procedures. Aggressive surgical corrections and inappropriate indications of initial LRR were two contributing factors for the late complications of IMPI. This study suggests that the IMPI may occur as a major complication of LRR, especially when the VL tendon is extensively released or when there is no confirmative clinical evidence of a tight LR preoperatively.

LEVEL OF EVIDENCE

IV.

Lateral patellofemoral ligament reconstruction to restore functional capacity in patients previously undergoing lateral retinacular release

AIM: To study patient outcomes after surgical correction for iatrogenic patellar instability.

METHODS: This retrospective study looked at 17 patients (19 knees) suffering from disabling medial patellar instability following lateral release surgery. All patients underwent lateral patellofemoral ligament (LPFL) reconstruction by a single surgeon. Assessments in all 19 cases included functional outcome scores, range of motion, and assessment for the presence of apprehension sign of the patella to determine if LPFL reconstruction surgery was successful at restoring patellofemoral stability.

RESULTS: No patients reported any residual postoperative symptoms of patellar instability. Also no patients demonstrated medial patellar apprehension or examiner induced subluxation with the medial instability test described earlier following LPFL reconstruction. Furthermore, all patients recovered normal range of motion compared to the contralateral limb. For patients with pre and postoperative outcome scores, the mean overall knee injury and osteoarthritis outcome score increased significantly, from 34.39 preoperatively (range: 7.7-70.12) to 69.54 postoperatively (range: 26.82-91.46) at final follow-up (P < 0.0001).

CONCLUSION: This novel technique for LPFL reconstruction is effective at restoring lateral restraint of the patellofemoral joint and improving joint functionality.

Iatrogenic Medial Patellar Instability: An Avoidable Injury

Iatrogenic medial patellar instability is a specific condition that frequently causes incapacitating anterior knee pain, severe disability, and serious psychological problems. The diagnosis should be suspected in a patient who has undergone previous patellar realignment surgery that has made the pain worse. The diagnosis can be established by physical examination and simple therapeutic tests (e.g., "reverse" McConnell taping) and confirmed by imaging techniques. This iatrogenic condition should no longer exist and could almost be eliminated by avoiding over-release of the lateral retinaculum.

The surgical treatment of anterior knee pain due to infrapatellar fat pad pathology: A systematic review

BACKGROUND

Anterior knee pain (AKP) encompasses a range of pathologies. As a result, there are a number of therapeutic options used to treat AKP. The non-operative treatments have been analysed in a number of randomised controlled trials and systematic reviews. There is however a scarcity of such publications covering the surgical management of AKP. There are no systematic reviews that have investigated surgical interventions for AKP due to pathology of the infrapatellar fat pad (IFP). The aims of this study were to review the literature systematically, to establish which surgical procedures have been used to treat IFP disease and to determine their efficacy.

METHODS

The review was conducted in accordance with the PRISMA reporting guidelines. A search of the literature was performed on 1st January 2014 using multiple databases including CENTRAL, MEDLINE, EMBASE, PubMed, and Google Scholar. The quality of the studies was assessed using Oxford Evidence-Based Medicine Levels of Evidence guidelines and the GRADE approach.

RESULTS

Twenty-four eligible studies were found and included. The critical appraisal identified that the current evidence-base has low methodology quality. The clinical findings indicated that there is a positive trend towards the surgical management of IFP disease for AKP symptoms. Excision of IFP tumours and resection of the IFP in Hoffa's disease can lead to improvements in symptoms and function.

CONCLUSIONS

Truly robust evidence to support the surgical management of IFP pathology requires randomised controlled trials; however the expenses involved to design such trials means that they are unlikely to be undertaken for this uncommon disorder. Consequently well-designed and well-reported case series need to be undertaken to improve our current understanding that includes recording quantitative measures such as range of knee motion, VAS Pain scores and a validated scoring system.

Deep Transverse Lateral Retinaculum Reconstruction for Medial Patellar Instability

Medial patellar instability can be a disabling complication of an extensive lateral retinaculum release. It is often overlooked, and for the diagnosis, it is necessary to have a high index of suspicion. Typically, the patient feels a new pain and new instability after the lateral retinaculum release that are distinct from, and much worse than, those before surgery. All of our patients had significant relief from their pain with "reverse" McConnell taping. If there is a significant improvement in symptoms after this taping and stress radiographs or stress axial computed tomography scans show an objective pathologic medial patellar displacement, reconstruction of the lateral retinaculum should be considered. This article details our technique for reconstruction of the deep transverse layer of the lateral retinaculum using an anterior strip of the iliotibial band. This strip is detached from its insertion onto the Gerdy tubercle and then reflected proximally beyond the level of the lateral femoral epicondyle. Finally, it is attached either by direct suture to the remaining prepatellar and peripatellar retinaculum if there is adequate tissue present or by a suture anchor.

Results of isolated lateral retinacular reconstruction for iatrogenic medial patellar instability

PURPOSE

The aim of this study was to assess the outcomes of an isolated lateral retinaculum reconstruction for iatrogenic medial patellar instability (IMPI) in patients with continued pain after failed lateral retinacular release (LRR), including associated psychometric analysis.

METHODS

Pain was assessed using the visual analog scale (VAS) and disability was determined with the Lysholm scale. Psychological variables such as anxiety, depression, catastrophizing, and fear-of-movement beliefs were studied by using self-administered psychometric questionnaires.

RESULTS

All 17 patients (13 women and 4 men) in this retrospective study had undergone LRR previously for anterior knee pain or lateral patellar instability. Four patients had undergone LRR plus proximal (Insall) realignment, and one had undergone LRR plus a medial tibial tubercle transfer. After their procedures, all had disabling symptoms. All patients underwent reconstructive surgery for IMPI. At a minimum follow-up of 2 years (range, 2 to 8 years), the mean preoperative VAS score was 7.6 (range, 5 to 9) and improved to 1.9 (range, 0 to 8) at the time of final follow-up (P < .001). The mean preoperative Lysholm score was 36.4 (range, 20 to 55), and the knee was described as bad (<65 points) in all cases. Postoperatively, it improved to 86.1 (range, 70 to 94) at final follow-up (P < .001). Before surgery, 4 patients (24%) had the clinical criteria for depression, 10 (59%) had anxiety, 7 (41%) had "catastrophizing" ideas concerning pain, and all (100%) had kinesiophobia (fear of movement). After surgery, none of the patients had depression or anxiety, none had catastrophizing ideation, and only 53% had kinesiophobia.

CONCLUSIONS

Reconstruction of the deep transverse layer of the lateral retinaculum (LR) using a central strip of the iliotibial band for IMPI in patients with continued pain after failed LRR can successfully treat these severely disabled patients.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Combined trochleoplasty and MPFL reconstruction for treatment of chronic patellofemoral instability: a prospective minimum 2-year follow-up study

PURPOSE

Excessive trochlear dysplasia may be responsible for recurrent patellofemoral instability (PFI) due to a missing bony guidance for the patella in early flexion. Thus, an isolated medial patellofemoral ligament reconstruction (MPFLR) can be insufficient, since it mainly addresses instability close to extension and additionally can increase patellofemoral pressure leading to pain in flat or convex trochlear dysplasia. Therefore, in combination with a trochleoplasty, an anatomical trochlear groove is created, resulting in patellofemoral stability also in flexion, while patellofemoral pressure is normalized. In this prospective study, we evaluated the outcome of open trochleoplasty in combination with MPFLR with a minimum follow-up of 2 years for treatment of excessive PFI.

METHODS

In between 2007 and 2009, 18 knees of 17 consecutive patients (mean age of 22.2 ± 4.9 years) with trochlear dysplasia type B, C or D according to Dejour et al. and positive apprehension from 0 to 60° of flexion were included. Tegner, Kujala and IKDC scores, apprehension and pain, trochlear dysplasia, sulcus angle, tibial tuberosity trochlear groove, patellar tilt and shift, Caton-Deschamps index as well as patellofemoral arthrosis according to the classification of Iwano et al. were assessed pre- and postoperatively.

RESULTS

At a mean of 30.5 ± 5.9 months, all but one patient were subjectively satisfied with the outcome of the procedure, all showing absence of positive apprehension or redislocation. Significant (p < 0.001) reduction in pain (5.6 to 2.5 ± 2.8 points, VAS) and increase in Tegner (2, range 0-4 points to 6, range 3-8 points), Kujala (51.1 to 87.9 ± 20.0 points) and IKDC (49.5 to 80.2 ± 21.0%) scores could be achieved. Radiologically significant (p < 0.02) improvement of patellofemoral positional parameters leading to more normal anatomy was recorded, while short-term arthrosis was absent.

CONCLUSIONS

Combined treatment for trochleoplasty with MPFLR serves as a successful therapy for chronic PFI. This combinatory treatment concept is a reliable option not only as salvage therapy but also as primary procedure regarding treatment for excessive PFI.

LEVEL OF EVIDENCE

Prospective case series, Level IV.

Treatment options for patellofemoral instability in sports traumatology

Patellofemoral instability not only involves lateral patellar dislocation, patellar mal-tracking or subluxation but can also cause a limiting disability for sports activities. Its underlying causes are known as morphological anomalies of the patellofemoral joint or the mechanical axis, femorotibial malrotation, variants of the knee extensor apparatus, and ligamentous insufficiencies often accompanied by poor proprioception. Athletes with such predisposing factors are either suffering from unspecific anterior knee pain or from slightly traumatic or recurrent lateral patellar dislocation Treatment options of patellar instability are vast, and need to be tailored individually depending on the athlete’s history, age, complaints and physical demands. Different conservative and surgical treatment options are reviewed and discussed, especially limited expectations after surgery.

The operative management of patella malalignment

Management of patellofemoral joint pathology is challenging as a result of the unique and complex organization of static forces and dynamic factors contributing to its functional capacity. Anterior knee pain is a common musculoskeletal complaint seen daily in the practices of primary care physicians, rheumatologists, and orthopedic surgeons. The key to successful treatment lies not only in the correct diagnosis of a chondral defect, but more importantly, in the accurate identification of associated pathomechanical factors. Appreciating the pathoanatomic basis of the disease and addressing imbalances and anatomical abnormalities should guide treatment.Despite the complexity of the interplay of various components it is essential to attempt to describe patellar malalignement as a clinical entity in order to proceed with appropriate surgical management and successful outcomes. The goals of patellofemoral re- alignment surgery should be to create both a stable environment for optimal extensor mechanism performance and an appropriate load transmission for optimal cartilage wear and joint loading. In the context of this article we will review the operative management of patellofemoral malalignment; the indications for surgery, the different techniques available and the evidence regarding their effectiveness.A large number of procedures have been employed and they have all undergone various modifications over the course of the years. The majority of publications are retrospective series in poorly defined population groups. There are significant methodological inconsistencies and as a result there is lack of strong evidence base for the majority of these procedures.