Open Lateral Retinacular Lengthening Compared with Arthroscopic Release. A Prospective, Randomized Outcome Study*:

Arthroscopic Lateral Retinacular-Lengthening Procedure

Anterior knee pain is a common musculoskeletal complaint that is often due to an excessively tight lateral retinaculum, which normally plays a role in patellar tracking and stabilization. Several etiologies underlie lateral soft-tissue tightness in the knee, including lateral patellar compression syndrome, patellofemoral arthritis, patellofemoral instability, and patellofemoral pain syndrome. Stretching the lateral retinaculum through conservative treatment may be helpful, but lateral retinacular lengthening may be indicated. Since this surgical procedure has classically been performed in an open fashion, the purpose of this Technical Note is to describe an arthroscopic technique designed to limit complications, improve patient outcomes, and reduce operative and recovery times.

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.

A Review of the Lateral Patellofemoral Joint: Anatomy, Biomechanics, and Surgical Procedures

The lateral patellofemoral joint soft tissues contain key structures that surround and balance the joint. These structures can affect joint tracking, stability, and force distribution. It is important to understand the lateral patellofemoral anatomy and biomechanics, and their relationship with patellofemoral instability, anterior knee pain, and osteoarthritis. Lateral-sided surgical procedures such as lateral release, lateral retinacular lengthening, and partial lateral patellar facetectomy can be useful in the treatment of such patellofemoral problems.

Treatment of Chronic Dislocated Patella in a Skeletally Mature Down Syndrome Patient: A Case Report

CASE

A 55-year-old man with Down syndrome (DS) suffered from chronic irreducible right patellar dislocation. Imaging studies showed an attenuated appearance of the medial patellar retinaculum, and the tibial tubercle to trochlear groove distance measured 1.6 cm. Right medial patellofemoral ligament reconstruction (MPFLR) and lateral lengthening (LL) with proximalization of the tibial tubercle (PTT) were performed with good surgical outcomes.

CONCLUSION

The combination of MPFLR, LL, and PTT is a viable option for treating a skeletally mature DS patient with patellofemoral instability causing recurrent patellar dislocation.

Open versus arthroscopic release for lateral patellar compression syndrome: a randomized-controlled trial

INTRODUCTION

Lateral patellar compression syndrome is one of the causes of anterior knee pain in young adults and resulted from tight lateral patellar retinaculum. The aim of our study is to compare between open and arthroscopic release of lateral patellar compression syndrome in relation of functional outcome, time of surgical procedure, length of hospital stays, intraoperative and postoperative complications as bleeding, infection, recurrence, and patellar instability with 2 years of follow-up.

MATERIALS AND METHODS

80 patients, age (21-49 years), were divided randomly into 2 groups (A and B). Group A (40 patients) were treated with open release. Group B (40 patients) were treated by arthroscopic release. All these patients are diagnosed as lateral patellar compression syndrome depending on clinical features and MRI. All patients were assessed by Lysholm knee scoring scale before surgery and at periods of 2, 6 weeks, 6, 12, and 24 months after surgery.

RESULTS

There is significant difference in functional outcome, measured by Lysholm knee scoring scale, between preoperative and postoperative assessment periods in both groups (P < 0.001). There is significantly better functional outcome at 2 years of follow-up with arthroscopic release (P = 0.018). There is no recurrence in both groups, but there were 4 patients develop medial patellar instability in the group of open release.

CONCLUSION

Both open and arthroscopic lateral release for patients with isolated lateral patellar compression syndrome can be effective surgical procedures, but arthroscopic release can achieve better functional outcome.

TRIAL REGISTRATION

NCT, NCT04130412. Retrospectively registered on 3rd of June, 2020 at ClinicalTrials.gov.

Internal Fixation of Lateral Trochlear Groove Osteochondritis Dissecans With Simultaneous Lateral Retinacular Lengthening in Adolescent Athletes

BACKGROUND

The goals of operative treatment for the adolescent athlete with unstable osteochondritis dissecans (OCD) lesion are rigid fixation and prevention of recurrence.

PURPOSE

To evaluate clinical and radiological outcomes of internal fixation of lateral trochlear groove OCD with simultaneous lateral retinacular lengthening.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Adolescent athletes who had undergone internal fixation and simultaneous lateral retinacular lengthening for an unstable OCD lesion of the lateral trochlear groove were retrospectively reviewed. Subjective assessments included the Lysholm score, International Knee Documentation Committee (IKDC) subjective score, Tegner activity scale, and an athletic questionnaire. Functional tests included isokinetic muscle strength, single-leg hop for distance, single-leg vertical jump, and Y-balance. Pre- and postoperative radiographs and magnetic resonance images were reviewed.

RESULTS

The mean ± SD age of the 17 patients included in this study was 15.9 ± 0.9 years; last clinical follow-up duration was 37.7 ± 8.1 months. At the last follow-up, the Lysholm score improved from 68.7 ± 15.3 to 93.4 ± 12.4 and the IKDC subjective score from 60.2 ± 14.7 to 88.7 ± 12.7 (P < .001). The mean Tegner activity scale score was 9.4 ± 0.5 before injury and 8.9 ± 1.2 at the last follow-up (P = .059). The limb symmetry indices of isokinetic muscle strength, single-leg hop for distance, single-leg vertical jump, and Y-balance improved at the last follow-up; the mean limb symmetry index was ≥85% in each functional test. Regarding the athletic questionnaire, 16 (94.1%) patients were satisfied with the surgery. At the last follow-up, 2 patients had higher ability after returning to sports, 11 had the same ability, and 3 had lower ability than the preinjury level. Postoperative magnetic resonance imaging at 12-month follow-up showed that the OCD lesion appeared healed in 7 (41.2%) patients and partially healed in 9 (52.9%).

CONCLUSION

Internal fixation of lateral trochlear groove OCD with simultaneous lateral retinacular lengthening in adolescent athletes achieved satisfactory clinical and radiological outcomes. Therefore, this combined surgical technique could be considered an effective treatment for lateral trochlear groove OCD, with a high rate of return to sport.

The Lateral Side: When and How to Release, Lengthen, and Reconstruct

The lateral patellofemoral complex is an important stabilizer to medial and lateral displacement of the patella. Soft tissue abnormalities can range from pathologic tightness to laxity, presenting with symptoms related to patellar instability, anterior knee pain, or arthritis. Clinical evaluation should be performed to confirm patellar dislocation, assess the integrity of the lateral and medial soft tissues, and explore other pathoanatomic factors that may need to be addressed. Lateral retinacular lengthening is recommended over lateral release owing to the potential of iatrogenic medial instability with release, and a lateral patellofemoral ligament reconstruction can be performed to effectively treat medial instability.

Lateral Patellar Retinaculum Z-Lengthening

The lateral retinaculum is a 2-layered structure. The plane between the superficial oblique fibers and the deep transverse fibers allows for coronal plane Z-lengthening of the lateral retinaculum. The lengthening procedure can be used for treatment of lateral patellar hypercompression syndrome or as an adjunct to surgical procedures undertaken to address patellar instability. This article describes the surgical technique for lateral retinacular lengthening.

LEVEL 1

Knee.

LEVEL 2

Malalignment, patellofemoral, other.

Medial Patellofemoral Ligament Reconstruction and Lateral Retinacular Lengthening from a Lateral Approach

The medial patellofemoral ligament (MPFL) is frequently torn and attenuated in patients with acute or chronic patellar instability. The mainstay for surgical treatment has become MPFL reconstruction to reestablish the checkrein to lateral patellar translation. The authors describe a technique for MPFL reconstruction with concomitant lateral retinacular lengthening with a gracilis allograft and adjustable loop cortical femoral fixation performed chiefly from a lateral parapatellar approach. This technique allows for reliable retensioning of the medial and lateral patellar soft tissues while avoiding complications associated with techniques that use interference screw fixation. Successful execution of this procedure provides a strong MPFL construct that allows patients to undergo early aggressive rehabilitation and return to activities.

Isolated Arthroscopic Lateral Retinacular Release for Lateral Patellar Compression Syndrome

Introduction: Evidence concerning the role of isolated lateral retinacular release (LRR) for lateral patellar compression syndrome (LPCS) dates back at least three decades. Appropriate indications, execution and outcomes still remain unclear and controversial. The present investigation analyzed the midterm result of isolated and arthroscopic LRR for LPCS in a cohort of patients who underwent such procedure at our institution. Material and methods: Patients undergoing isolated arthroscopic LRR for LPCS were identified retrospectively from our electronic database. All procedures were performed by two experienced surgeons. Patients with bony and/or soft tissues abnormalities, patellofemoral instability, moderate to severe chondral damage were not included. Patients with previous surgeries were not included, as were those who underwent combined interventions. Clinical scores and complications were recorded. Results: 31 patients were recruited in the present investigation. The mean follow-up was 86.0 ± 22.8 months. The mean age of the patients at the index operation was 34.2 ± 13.1 years. A total 55% (17 of 31) were women, and 58% (18 of 31) had involved the right knee. The mean hospitalization length was 3.5 ± 1.4 days. At a mean follow-up of 86.0 ± 22.8 months, the numeric rating scale (NRS) was 1.2 ± 0.8, the Kujala score was 91.3 ± 11.3, the Lysholm score was 93.1 ± 15.0, and the Tegner score was 5.0 ± 1.8. At the latest follow-up, 9 of 31 (29.0%) of patients experienced compilations. One patient (3.2%) had a post-operative hemarthrosis which was managed conservatively. Six patients (19.4%) reported a persistent sensation of instability, without signs of patellar dislocation or subluxation. One patient underwent an arthroscopic meniscectomy, and another patient an anterior cruciate ligament (ACL) reconstruction. Conclusion: isolated arthroscopic lateral retinacular release for lateral patellar compression syndrome is feasible and effective, achieving satisfying results at more than seven years following the procedure.

Management of Patellar Chondral Defects with Autologous Matrix Induced Chondrogenesis (AMIC) Compared to Microfractures: A Four Years Follow-Up Clinical Trial

Introduction: Evidence on the management of chondral defects of the patella arises from studies in which the patellofemoral joint was treated together with the femorotibial joint and primary and revision settings. Furthermore, the superiority of Autologous Matrix Induced Chondrogenesis (AMIC) over microfractures (MFx) for patellar chondral defects is uncertain. Therefore, the present study compared primary isolated AMIC versus MFx for focal unipolar chondral defects of the patellar facet joints at midterm follow-up. Methods: Patients undergoing AMIC or isolated MFx surgery for borderline-sized focal unipolar chondral defects of the patellar facet joints were followed at our institution. All surgeries were performed in the same fashion by experienced surgeons. A parapatellar arthrotomy was adopted in all surgeries. The outcomes of interest were: Visual Analogic Scale (VAS), Tegner Activity Scale, International Knee Documentation Committee (IKDC), and the Lysholm scores. The Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) was assessed by a blinded radiologist, who had not been involved in the clinical management of the patients. Results: 38 patients were enrolled in the present study: 27 underwent AMIC, and 11 MFx. The mean follow-up was 45.1 months. The mean age of the patients at baseline was 34.5 years. The mean size of the defect was 2.6 cm². The MFx cohort experienced a shorter length of the hospitalization (P = 0.008). There was no difference in terms of follow-up and previous symptoms duration, mean age, sex, side, defect size, and BMI. At last follow-up, the AMIC cohort reported greater IKDC (P = 0.01), Lysholm (P = 0.009), and Tegner (P = 0.02), along with a low rate of failure (P = 0.02). VAS was lower in the AMIC group (P = 0.002). No difference was found in the MOCART score (P = 0.09), rates of revision (P = 0.06), and arthroplasty (P = 0.2). Conclusion: The AMIC procedure achieves greater IKDC and Lysholm score, and a significant reduction of the VAS score in the management of patellar chondral defects. The Tegner scale demonstrated greater activity after AMIC procedure. Finally, the AMIC group evidenced a lower rate of failure. Similarity was found on MOCART score, rates of revision, and arthroplasty between the two procedures.

Medical Interventions for Patellofemoral Pain and Patellofemoral Osteoarthritis: A Systematic Review

Patellofemoral pain (PFP) and patellofemoral osteoarthritis (PFOA) are common, persistent conditions that may lie along a pathological spectrum. While evidence supports exercise-therapy as a core treatment for PFP and PFOA, primary care physicians commonly prescribe medication, or refer for surgical consults in persistent cases. We conducted a systematic review of medical interventions (pharmaceutical, nutraceutical, and surgical) for PFP and PFOA to inform primary care decision making. Methods: Following protocol registration, we searched seven databases for randomized clinical trials of our target interventions for PFP and PFOA. Our primary outcome was pain. We assessed risk of bias, calculated standardized mean differences (SMDs) and determined the level of evidence for each intervention. Results: We included 14 publications investigating pharmaceutical or nutraceutical interventions, and eight publications investigating surgical interventions. Two randomized control trials (RCTs) provided moderate evidence of patellofemoral arthroplasty having similar pain outcomes compared to total knee arthroplasty in isolated PFOA, with SMDs ranging from −0.3 (95% CI −0.8, 0.2, Western Ontario McMaster Pain Subscale, 1 year post-surgery) to 0.3 (−0.1, 0.7, SF-36 Bodily Pain, 2 years post-surgery). Remaining studies provided, at most, limited evidence. No efficacy was demonstrated for oral nonsteroidal anti-inflammatories or arthroscopic surgery. Conclusions: Pharmaceutical and nutraceutical prescriptions, and surgical referrals are currently being made with little supporting evidence, with some interventions showing limited efficacy. This should be considered within the broader context of evidence supporting exercise-therapy as a core treatment for PFP and PFOA.

Combined medial and lateral patellar retinaculum plasty for skeletally immature patients with patellar dislocation and low-grade trochlear dysplasia

BACKGROUND

To evaluate the clinical outcomes of combined medial and lateral patellar retinaculum plasty for skeletally immature patients with patellar dislocation and low-grade trochlear dysplasia.

METHODS

From December 2014 to December 2016, we reviewed 19 skeletally immature patients who underwent medial and lateral patellar retinaculum plasty at our institution. Clinical evaluations were performed pre- and postoperatively, and included determination of the number of patellar re-dislocation patients, the Kujala and Tegner scores, the patellar tilt angle, lateral patellar shift, and congruence angle. The radiographic evaluation parameters were measured on computed tomography scans.

RESULTS

No dislocation or subluxation occurred during the mean follow-up of 35.42 months (24-48 months). Postoperatively, the Kujala score improved from 57.6 ± 4.2 to 86.9 ± 8.1 (P < 0.05), and the Tegner activity score improved from 2.6 ± 1.0 to 5.0 ± 1.3 (P < 0.05). Radiographically, the patellar tilt angle decreased from 32.7 ± 5.9° to 13.4 ± 4.28° (P < 0.05), the lateral patellar shift decreased from 15.9 ± 1.1 mm to 8.4 ± 0.6 mm (P < 0.05), and the congruence angle decreased from 29.9 ± 15.3° to -9.6 ± 15.5° (P < 0.05).

CONCLUSIONS

Medial and lateral patellar retinaculum plasty is a promising procedure that has the advantage of being a simple operation that induces little trauma. It is a good treatment option for skeletally immature patients with patellar dislocation who have low-grade trochlear dysplasia.

Lateral retinaculum plasty instead of lateral retinacular release with concomitant medial patellofemoral ligament reconstruction can achieve better results for patellar dislocation

PURPOSE

To elucidate the outcomes of lateral retinaculum plasty versus lateral retinacular release with concomitant medial patellofemoral ligament (MPFL) reconstruction.

METHODS

In a prospective study, 59 patients treated at our institution from 2012 to 2014 were included. The 59 patients were randomly divided into two groups. Group I included 27 patients who underwent lateral retinacular release and MPFL reconstruction. Group II included 32 patients who underwent lateral retinaculum plasty and MPFL reconstruction. All patients were followed up for at least 2 years and all assessments were performed both pre- and post-operation. Clinical evaluation consisted of the Kujala score, patellar medial glide test, and patellar tilt angle, patellar lateral shift, and congruence angle, measured on CT scan.

RESULTS

Significant improvement was seen after surgery in both groups. The group of lateral retinaculum plasty achieved better results than the group of lateral retinacular release. No statistically significant differences were found in lateral patellar shift (ns) or congruence angle (ns) between the groups. There were significant differences in Kujala score (P < 0.05) patellar tilt angle (P < 0.05), and patellar medial glide test (P < 0.05) between the groups.

CONCLUSIONS

MPFL reconstruction with lateral retinaculum plasty yielded better results than MPFL with lateral retinacular release. Postoperatively, medial and lateral function were restored, and patellar tracking was normal. Lateral retinaculum plasty is a new method that reduces the complications of lateral retinacular release for patellar dislocation.

LEVEL OF EVIDENCE

II.

Avoiding Complications with MPFL Reconstruction

PURPOSE OF REVIEW

To discuss the potentially significant complications associated with medial patellofemoral ligament (MPFL) reconstruction. Additionally, to review the most current and relevant literature with an emphasis on avoiding these potential complications.

RECENT FINDINGS

Multiple cadaveric studies have characterized the anatomy of the MPFL and the related morphologic abnormalities that contribute to recurrent lateral patellar instability. Such abnormalities include patella alta, excessive tibial tubercle to trochlear grove (TT-TG) distance, trochlear dysplasia, and malalignment. Recent studies have evaluated the clinical outcomes associated with the treatment of concomitant pathology in combination with MPFL reconstruction, which is critical in avoiding recurrent instability and complications. Although there remains a lack of consensus regarding various critical aspects of MPFL reconstruction, certain concepts remain imperative. Our preferred methods and rationales for surgical techniques are described. These include appropriate work up, a combination of procedures to address abnormal morphology, anatomical femoral insertion, safe and secure patellar fixation, appropriate graft length fixation, and thoughtful knee flexion during fixation.

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.

Coronal patellar osteotomy of the external facet combined with the release of the lateral retinaculum improves the clinical outcomes of isolated lateral release in lateral knee compartment syndrome

OBJECTIVE

To describe a novel coronal osteotomy of the external facet of the patella, and to evaluate if the outcomes of the treatment of lateral knee compartment syndrome (LKCS) with this osteotomy, combined with the release of the external lateral retinaculum, are better than the isolated lateral retinacular release.

MATERIAL AND METHODS

A prospective study with a 2 year follow up that included 70 patients diagnosed with LKCS, distributed into 2 groups. The first group included 50 patients on whom the lateral retinacular release combined with osteotomy was performed, and a second group on whom an isolated retinacular release was performed. Measurements were made using the Werner functional scale before the surgery and at 3, 12, and 24 months follow-up.

RESULTS

There were significant differences in the overall functional state between the two groups after the surgery (better in the osteotomy group at all the intervals, P<.05). The improvement, which was progressive up to 12 months, was slightly less at 24 months, although the values were still better than the pre-surgical ones in both groups. Pain was the variable that showed most improvement. The patients with LKCS with degenerative signs showed a benefit in all cases.

CONCLUSION

The results demonstrate that the described patellar osteotomy technique, combined with lateral retinacular release, significantly improves the pain and the functional scale score of patients with LKCS after 2 years of follow-up, to a greater extent than isolated lateral retinacular release, including those in which there was evidence of degenerative signs.

Efficacy and mid term results of lateral parapatellar approach without tibial tubercle osteotomy for primary total knee arthroplasty in fixed valgus knees

The lateral parapatellar approach, despite providing direct access to the pathological area has not been widely accepted for knee arthroplasty in valgus deformities. We performed a modified lateral (Keblish) approach which consisted of coronal z plasty of lateral retinaculum, quadriceps snip, titrated sequential lateral release and closure with expanded lateral structures in 32 arthritic fixed valgus knees. In 30 knees, either tendon of popliteus or lateral collateral ligament or both could be preserved. At an average follow-up of 5 years, the valgus alignment improved from 25.4° (11°-60°) to 4° (0°-10°) and knee society score improved from 34 to 95 points. There was no late instability or revisions. This approach is rational, eliminates patella maltracking, is applicable in severe deformities and with titrated release, can preserve the posterolateral knee stabilizers that are necessary for long term implant survival.

Complications in patellofemoral surgery

The complexity of patellofemoral morphology, combined with its injuries and degenerative patterns, leads to varied pathologic diagnoses, as well as surgical procedures to address these problems. Surgical procedures in the patellofemoral joint include tibial tubercle osteotomy, medial patellofemoral ligament surgery, soft tissue procedures on the lateral aspect of the patella, trochleoplasty, and patellofemoral arthroplasty. Understanding potential complications related to the various surgical procedures in the patellofemoral joint is critical to successful surgery. The purpose of this article is to discuss potential surgical complications in procedures performed to address patellofemoral pathology and describe ways to avoid these pitfalls.

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.

Open lateral patellar retinacular lengthening versus open retinacular release in lateral patellar hypercompression syndrome: a prospective double-blinded comparative study on complications and outcome

PURPOSE

To compare complication rates and outcome of open lateral retinacular (LR) lengthening and open LR release in the treatment of lateral patellar hypercompression syndrome (LPHS).

METHODS

In a prospective double-blinded study, 28 patients (mean age, 48 years; 21 women and 7 men) received either LR release (14 patients) or LR lengthening (14 patients) in alternating fashion over the same lateral parapatellar skin incision for LPHS (blinding of patients to surgical procedure [i.e., single blinding]). Strict inclusion criteria (retinacular pain, tight retinaculum, decreased patellar mobility) were used to exclude other reasons for anterior knee pain (patellar instability, leg malalignment or maltorsion, trochlear dysplasia, patella alta). The surgeon and postsurgical rehabilitation were the same. Preoperatively and at 3, 6, 12, and 24 months postoperatively, complications, muscle atrophy, and Kujala patellofemoral outcome score were documented by examiners blinded to the surgical procedure (double blinding). All patients completed 2 years of follow-up.

RESULTS

The results of 2 years of follow-up showed that recurrence of LPHS, as indicated by the patellar tilt test and decreased medial patellar glide test, developed in 2 cases after LR release and 1 case after LR lengthening (P > .999). Medial patellar subluxation, as indicated by the gravitation-subluxation test and increased medial patellar glide test, developed in 5 cases after LR release and no case after LR lengthening (P = .041). Quadriceps atrophy, as indicated by the mean circumference difference compared with the healthy contralateral side, was significantly higher (P = .001) in the LR release group (1.8 cm) than in the LR lengthening group (0.2 cm). The mean Kujala score was significantly lower (P = .035) in the LR release group (77.2 points) than in the LR lengthening group (88.4 points).

CONCLUSIONS

In this prospective double-blinded study, retinacular lengthening showed less medial instability, less quadriceps atrophy, and a better clinical outcome at 2 years compared with retinacular release. We believe that this may be explained by the controlled preservation of the lateral patellar muscle-capsuloligamentous continuity after retinacular lengthening.

LEVEL OF EVIDENCE

Level II, prospective double-blinded comparative study.

Importância do ligamento femoropatelar medial no deslocamento e na inclinação lateral da patela: estudo radiográfico em cadáveres

OBJETIVO: A luxação aguda da patela é uma afecção complexa que afeta principalmente pacientes jovens. Sua fisiopatologia é pouco conhecida e sua compreensão e conduta terapêutica são controversas. O ligamento femoropatelar medial (LFPM) é o principal estabilizador estático para a prevenção do deslocamento lateral da patela. Com o objetivo de avaliar a estabilidade da articulação femoropatelar, os autores avaliam radiograficamente a presença, ou não, de deslocamento e inclinação lateral da patela, antes e após a secção do LFPM em joelhos de cadáveres. MÉTODOS: Trinta joelhos de cadáveres foram radiografados na incidência axial da patela, por meio da técnica descrita por Merchant antes e após a secção do LFPM. Foram mensurados os ângulos de congruência de Merchant e femoropatelar lateral de Laurin. RESULTADOS: O ligamento femoropatelar medial apresentou média de 4,8cm de comprimento e 1,6cm de largura. Em seis peças anatômicas não ocorreu mudança no ângulo femoropatelar lateral de Laurin (20%), em três peças anatômicas a mudança foi de um grau (10%), em 20 (67%), dois graus e uma peça anatômica quatro graus (3%). As mudanças ocorreram entre zero e dois graus, em 97% dos joelhos de cadáveres. Em cinco peças anatômicas não ocorreu mudança no ângulo de congruência de Merchant (17%); em seis, foi de um grau (20%); em 17, dois graus (57%); em uma, três graus (3%); e em uma, seis graus (3%).Estas mudanças ocorrem entre zero e dois graus em 93% dos joelhos de cadáveres). CONCLUSÕES: A análise dos resultados obtidos neste estudo permite concluir que o ligamento femoropatelar medial tem importância na inclinação e no deslocamento lateral da patela com o joelho fletido em 45º.

Knee arthroscopy and exercise versus exercise only for chronic patellofemoral pain syndrome: a randomized controlled trial

BACKGROUND

Arthroscopy is often used to treat patients with chronic patellofemoral pain syndrome (PFPS). As there is a lack of evidence, we conducted a randomized controlled trial to study the efficacy of arthroscopy in patients with chronic PFPS.

METHODS

A total of 56 patients with chronic PFPS were randomized into two treatment groups: an arthroscopy group (N = 28), treated with knee arthroscopy and an 8-week home exercise program, and a control group (N = 28), treated with the 8-week home exercise program only. The arthroscopy included finding-specific surgical procedures according to current recommendations. The primary outcome was the Kujala score on patellofemoral pain and function at 9 months following randomization. Secondary outcomes were visual analog scales (VASs) to assess activity-related symptoms. We also estimated the direct healthcare costs.

RESULTS

Both groups showed marked improvement during the follow-up. The mean improvement in the Kujala score was 12.9 (95% confidence interval (CI) 8.2-17.6) in the arthroscopy group and 11.4 (95% CI 6.9-15.8) in the control group. However, there was no difference between the groups in mean improvement in the Kujala score (group difference 1.1 (95% CI -7.4 - 5.2)) or in any of the VAS scores. Total direct healthcare costs in the arthroscopy group were estimated to exceed on average those of the control group by euro901 per patient (p < 0.001).

CONCLUSION

In this controlled trial involving patients with chronic PFPS, the outcome when arthroscopy was used in addition to a home exercise program was no better than when the home exercise program was used alone.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN 41800323.

Anterior knee pain: diagnosis and treatment

Anterior knee pain is a frequent clinical problem. It provides a common challenge to diagnose and manage. Basic science studies have provided insight into the origin of anterior knee pain and refined understanding of the anatomy. Clinical evaluation has progressively focused on the contribution of the entire lower extremity to patellofemoral function. Nonsurgical management has been refined by the concept of the "envelope of function" and by increased understanding of the neuromuscular control of the knee. Indications for lateral release have been clarified and narrowed. Although anteromedial transfer of the tibial tuberosity is helpful in certain circumstances, reports of postoperative fracture have led to less aggressive rehabilitation protocols. Chondral resurfacing of the patellofemoral joint and patellofemoral arthroplasty are evolving. Emphasis should remain on nonsurgical management, which is sufficient in most patients.

Full arthroscopic lateral retinacular release with hook knife and quadriceps pressure-pull test: long-term follow-up

The most important causes of anterior knee pain include patellofemoral malalignment which causes patella-condyle contact anomalies at the patellofemoral joint, excessive patellar lateral pressure increase, trauma and overuse. In this article, besides presentation of late clinical results of 169 lateral retinacular release cases which were surgically treated between January 1995 and December 2002 with the help of a hook knife from the anterolateral portal due to lateral compression syndrome and patellar maltracking, we also described quadriceps tendon pressure-pull test which strongly indicates patellofemoral pain during physical examination of a patient with anterior knee pain. In addition to radiological patellofemoral imaging methods, we describe dynamic arthroscopic patellofemoral joint examination which is applied perarthroscopically to all of our surgically treated patients. We divided the patients into two groups: group 1 was the younger group with age 16-40 years; group 2 was the older group with age >41 years. Preoperative mean Lysholm scores for group I was 67.6 and 98.6, postoperatively, whereas it was 62.3 preoperatively and 91.4 postoperatively in group 2. This improvement of Lysholm scores postoperatively was statistically significant for each of the two groups (p=0.001). For group 1 preoperative IKDC scores were A in 8 patients, B in 61 patients and C in 11 patients, whereas it was A in 78 patients and B in 2 patients postoperatively. For group 2 preoperative IKDC scores were A in 2 patients, B in 43 patients, C in 36 patients and D in 8 patients, whereas it was A in 78 patients and B in 11 patients. This improvement of IKDC scores postoperatively was also statistically significant for each of the two groups (p=0.001). Preoperative and postoperative congruent angles of all patients were also measured. Preoperative mean congruent angle was +16.4 in group 1 while mean congruent angle was -7.1 postoperatively. For group 2 preoperative mean congruent angle was +18.7 preoperatively and -6.9 postoperatively. This improvement was statistically significant for each of the two groups (p=0.001). The overall number of patellar lateral compression syndrome cases were 51 (24 in group 1, 27 in group 2), patellar lateralization cases were 64 (28 in group 1, 36 in group 2) and patellar subluxation cases were 54 (28 in group 1, 26 in group 2). At the evaluation of arthroscopic lateral patellar facet and lateral femoral condylar chondral pathologies, we statistically showed that patellar chondral pathologies were more severe than the femoral chondral pathologies (p=0.001). In our opinion, the severity of patellar lateral facet chondral lesions, although it has a thicker layer of cartilage, is due to distribution of load to a larger contact area of lateral femoral condyle. Statistically increasing severity of femoral (Kendall's tau-b: 0.248, p=0.001) and patellar chondral lesions (Kendall's tau-b: 0.444, p=0.0001) with age is compatible with our arthroscopic and clinical observations. The most important complication seen in our cases was fibrosis at the site of lateral release, seen in three patients. They were healed without any sequela with local corticosteroid injection into the fibrosis tissue. We did not see any hemarthrosis or haematoma as a complication.

Patellofemoral malalignment: looking beyond the viewbox

A clear understanding of the pathophysiology of anterior knee pain is inhibited by the use of imprecise, poorly defined, and often interchanged words, such as malalignment, patellar alignment, maltracking, subluxation, dislocation, and congruence. The literature is filled with articles regarding the diagnosis, "malalignment of the patella," most of which give no precise diagnosis. This article presents a definition of malalignment and a plea for rational descriptive and scientific analysis. Much of what is described is based on theory, not facts. These ideas are supported by clinical experience and logical analysis, but very little in the way of scientific data. Most of the data involve radiographic images, which present only one piece of the puzzle.

Predicting physical therapy visits needed to achieve minimal functional goals after arthroscopic knee surgery

STUDY DESIGN

Retrospective, cross-sectional regression modeling.

OBJECTIVE

To predict physical therapy visits following arthroscopic knee surgery.

BACKGROUND

The number of physical therapy visits required to achieve a set of specific minimal-level goals (full knee extension, straight leg raise, normalized gait pattern, bicycle pedaling, and independent home exercises) that are related to decreased complication rates has not previously been modeled.

METHODS AND MEASURES

A multiple regression model to predict postoperative physical therapy visits was developed using subject demographics and 2 simple clinical measures, degree of straight leg raise lag and total range of motion. All data were collected from 148 patient charts. Model validity was examined by the predicted residual sum of squares technique and a second independent sample of 157 charts.

RESULTS

Diagnosis group, surgery group, and range of motion were the significant variables predicting visits in the final model (R2 = 0.384). Results of model validation analyses using predicted residual sum of squares technique (R2 = 0.346) and the second set of data (R2 = 0.282) were satisfactory. Analysis of residuals (difference of observed and predicted visits) showed prediction of the number of physical therapy visits within 3 visits for approximately 75% of the cases in both sets of data.

CONCLUSIONS

Using the model to predict physical therapy visits following arthroscopic knee surgery was more accurate than using diagnosis alone, except for lateral retinacular release. This study demonstrates how regression models could be used to explain variance in physical therapy visits for a given set of minimal functional goals.