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Isolated lateral release or lateral lengthening for non-instability indications: A systematic review
, Brandon A. Youngb, Ji S. China, Austin V. Stoneb, Joseph N. Liua
⁎Corresponding author: Andrew B. Barcenas. andrew.barcenas@med.usc.edu
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Received: ,
Accepted: ,
This article was originally published by Reed Elsevier India Pvt. Ltd. and was migrated to Scientific Scholar after the change of Publisher.
Abstract
Abstract
Isolated lateral release (LR) and lateral lengthening (LL) may have a role in the management of knee pain without instability, but these indications have not been clearly defined. This study sought to evaluate the use of isolated lateral release and lateral lengthening for non-instability indications of the knee.
PubMed, Embase, and Web of Science were queried for terms related to lateral release and lateral lengthening of the knee. Included studies investigated isolated LR or LL as an intervention for non-patellofemoral instability indications of the knee that were published in English and in peer-reviewed journals. Studies were excluded if they investigated LR or LL for patellofemoral instability or during total knee arthroplasty, published before 2000, systematic reviews, biomechanical studies, and case reports. Surgery indications, patient demographics, patient-reported outcome measures (PROMs), complications and subsequent surgeries, were collected.
Seven studies with 404 patients were included, 4 of which investigated LR/LL for lateral patellar compression syndrome (LPCS), 1 for anterior knee pain, 1 for patellofemoral arthritis, and 1 for patellofemoral arthrofibrosis following anterior cruciate ligament reconstruction. All seven studies reported significant improvements in PROMs and clinical outcomes, regardless of indication. The most common complications were postoperative hemarthrosis, medial patellar instability, and fibrosis.
Isolated LR and LL are viable options for the management of LPCS, anterior knee pain, and postoperative patellofemoral arthrofibrosis that lead to improvements in PROMs. Medial patellar instability is a feared complication of LR/LL but appears to be more likely in patients undergoing LR.
Systematic Review; LOE IV
Keywords
Lateral release
Lateral lengthening
Lateral patellar compression syndrome
Iatrogenic medial patellar instability
1 Introduction
Lateral release (LR) and lateral lengthening (LL) are two procedures that have been traditionally employed in the management of patellar instability. While LR and LL were at one time performed in isolation in an attempt to mitigate lateral patellar dislocations, this has since fallen out of favor. With 89% agreement, the International Patellofemoral Study Group concluded that LR should not be performed in isolation for this indication.1 Both LR and LL have been shown to increase the risk of medial patellar instability.2
While the use of LR and LL as isolated procedures is no longer recommended for patellar instability management, there may still be indications for their isolated use. Anterior knee pain is an extremely common clinical presentation, especially in the young and active population.3,4 The lifetime prevalence is estimated to be 25%.3 Patellar compression syndrome (PCS) is a common cause of anterior knee pain in patients without patellar instability.5 PCS is thought to occur as a result of tight lateral retinacular structures resulting in increased pressure on the lateral facet.6 This increased pressure is correlated with increasing articular cartilage damage over time in patients with PCS.7 Research from the 1970s describes promising results of isolated LR for the management of PCS.6,8 Given the high prevalence of anterior knee pain and the proposed mechanism of patellar compression syndrome, a modern investigation into the use of isolated LR and LL for noninstability indications is warranted.
Using a systematic review methodology, this study aims to identify the use of isolated LR and LL for patients without patellar instability. A secondary aim is to identify the efficacy and complications associated with isolated LR and LL in this patient population.
2 Methods
2.1 Study screening
Following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines, a systematic review was carried out.9 PubMed, Scopus, and Web of Science were queried using the search method: ("lateral release" OR "lateral lengthen*") AND ("patellofemoral pain" OR "anterior knee pain" OR "compression syndrome" OR "knee pain"). Studies were collected and compiled into Covidence (Melbourne, Australia). Inclusion criteria were primary studies investigating the use of isolated LR/LL for the management of knee pain without patellar instability that were published in English and in peer-reviewed journals. Excluded studies were biomechanical and animal studies, systematic reviews, case reports, and studies using LR/LL for total knee arthroplasty or patellar instability. Two authors (C.L.F. and E.H.L.) independently screened studies in two steps, first by title and abstract, then by full text. A third author (B.A.Y) was available to resolve any conflicts.
2.2 Study quality
A study quality check was done based on study type. For non-randomized studies, the methodological index for non-randomized studies (MINORS) was utilized.10 For randomized studies, the Jadad scale was utilized.11
2.3 Data Collection
Study characteristics including level of evidence, subject group size, and follow-up time were collected. Average patient age and surgical indications were recorded. Patient preoperative and intraoperative findings were also collected, including Iwano patellofemoral arthritis and cartilage Outerbridge grades. Any study outcomes including patient-reported outcome measures (PROMs) and clinical outcomes were also recorded. Data was compiled descriptively.
3 Results
After screening 227 studies, a total of 7 were included for analysis (Fig. 1). The average MINORS score for non-comparative studies was 9.75,1,2,9,15 and for comparative studies was 21.5.12,13 The Jadad score for the single randomized controlled trial was 4.14 From these 7 studies, 404 patients were investigated. The mean age ranged from 32 to 49 years old (Table 1). Four of these studies described their patient population as having PCS or lateral patellar hypercompression syndrome.12–15 Calpur et al. investigated LR/LL for multiple causes of anterior knee pain, including PCS.7 Fosco et al. investigated isolated LR/LL for patellofemoral arthritis.16 Calloway et al. included patients with patellofemoral arthrofibrosis following anterior cruciate ligament reconstruction.17
| Study | Indication | Subjects | Mean Age | % Female | Mean Follow Up |
| Fosco et al.16 | Patellofemoral Arthritis | 25 | 44.6 (23–65) | 56% | 32.4 months |
| Migliorini et al.15 | Lateral Compression Syndrome | 31 | 34.2 ± 13.1 | 55% | 86 ± 22.8 months |
| Pagenstert et al.13 | Lateral Compression Syndrome | 28 (14 LL, 14 LR) | 48.0 ± 11.6 for LR group47.6 ± 9.9 for LL group | 75% | 2 years |
| Hamawandi et al.14 | Lateral Compression Syndrome | 80 (40 open LR, 40 arthroscopic LR) | 21–49 | 51.3% | 2 years |
| Chen et al.12 | Lateral Compression Syndrome | 125 (66 through synovial membrane, 59 outside synovial membrane) | 48.3 for through synovial membrane group49.2 for outside synovial membrane group | 67.2% | 3.4–3.5 years |
| Calpur et al.7 | Anterior Knee Pain | 80 (51 with PCS) | 16–82 | 57.1% | 36 months |
| Calloway et al.17 | Patellofemoral Arthrofibrosis After ACL Reconstruction | 44 | 32.8 (19–58) | 56.3% | 43.6 months |
3.1 Patellar compression syndrome
Patellar compression syndrome as an indication for isolated LL or LR was defined as maximal pain and tenderness over the lateral margin of the patellar with an abnormal patellar tilt test and an abnormal medial patellar glide test (cannot be shifted by one or more quadrants with the knee in ten degrees of flexion) by Hamwandi et al.14 The same inclusion criteria was utilized by Pagenstert et al.13 Migliorini et al. included patients with patellofemoral pain affecting quality of life with evidence of lateral compression syndrome on MRI but did not provide an objective definition of MRI evidence.15 For Chen et al. the indication for the procedure was a preoperative examination demonstrating a tight lateral patellar retinaculum and imaging demonstrated patellar tilt to the outside with a normal Q angle.12
In the five studies that investigated isolated LL/LR for PCS, four (80%) reported a significant improvement in PROMs (Table 2).7,12–14 The single study that did not report significant improvement had not reported preoperative scores and only provided postoperative scores for the numeric rating system (NS), Kujala, Lysholm, and Tegner scores.15 The Lysholm score was reported most frequently, used in 4 (80%) studies. Clinical outcomes reported varied between studies, and Migliorini et al. did not report any outside complications.15 Chen et al. and Pagenstert et al. both reported a significant increase in medial patellar glide.12,13 The procedure did not relieve the PCS in 3 (10.7%) patients in Pagenstert et al.13 The most frequently reported complication was hemarthrosis, seen at a rate of 0–29%. Medial patellar instability was also seen postop, iteratively, at rates of 5% and 36%.13,14 Pagenstert et al. found that medial instability was significantly associated with LR compared to LL.13 Migliorini et al. reported 6 cases who developed sensations of instability postoperatively but did not indicate direction or if any objective subluxations or dislocations occurred.15
| Study | PROMs | Clinical Outcome | Complications |
| Migliorini et al.15 | -Numeric Rating System (NRS): 1.2 ± 0.8-Kujala: 91.3 ± 11.3-Lysholm: 93.1 ± 15.0-Tegner: 5.0 ± 1.8 | 29% (9 patients) complication rate: 1 hemarthrosis, 6 reported sensation of instability, 1 subsequent meniscectomy and 1 subsequent ACL reconstruction | |
| Pagenstert et al.13 | Kujala score similar between LL and LR at 1 year postop (n.s.) but LL performed significantly better at 2 years postop* | −2 LR patients had consistent compression syndrome, 1 LL patient had consistent compression syndrome (n.s.)-LR patients had more medial patellar glide than LL patients*-LR patients had worse quadriceps atrophy than LL patients* | Medial patellar subluxation in 5 (36%) LR patients and 0 LL patients* |
| Hamawandi et al.14 | Lysholm score improved at all follow up points for both groups* | No recurrence of PCS | Intraop complication: joint capsule opened in 5 patients of the open group (n.s.)1 open patient developed superficial wound infection (n.s.)2 arthroscopic patients developed hemarthrosis (n.s.)4 open patients developed medial patellar instability (n.s.) |
| Chen et al.12 | Lysholm and Kujala scores improved for both groups*VAS pain scores decreased for both groups* | Patella medial shift increased in both groups* | 5 cases hemarthrosis, 3 joint adhesions in the through synovial membrane groupNo complications in the outside synovial membrane group* |
| Calpur et al.7 | IKDC scores improved*Lysholm scores improved* | Congruens angles improved* | 3 cases of fibrosis at site of LR |
3.2 Patellofemoral arthritis
Fosco et al. investigated isolated LR/LL for patellofemoral arthritis in 28 knees (25 patients) with an average follow up 32 months.16 These patients underwent LR followed by viscosupplementation starting at a mean of 2.6 months postoperative. Among these patients, 10 were Iwano grade 1, 13 Iwano grade 2, and 5 Iwano grade 2. The improvement in pain according to the VAS pain scale was 68.5%. The Kujala score improved significantly postoperatively. Younger patients demonstrated significantly better improvements in Kujala scores. Fosco et al. reported no complications or reoperations.
3.3 Postoperative patellofemoral arthrofibrosis
Calloway et al. reported on patients with patellofemoral arthrofibrosis following ACL reconstruction.17 This case series included 32 patients with an average of 43.6 months of follow up. In these patients’ hyperplastic fat pads were also removed if identified as a concomitant procedure. IKDC scores improved significantly, with 16 (50%) achieving minimal clinically important difference (MCID). The Western Ontario and McMaster Universities Arthritis Index (WOMAC) score also improved significantly, with 15 (46.9%) achieving MCID. Subjectively, 31 (97%) reported that the procedure helped. This study did not report complications.
4 Discussion
Isolated LR and LL can be used with good success for knee pain that is not a consequence of patellar instability. Five studies identified beneficial outcomes for isolated LR or LL in patients with PCS. Two additional studies identified promising outcomes for patients with postoperative patellofemoral arthrofibrosis and patients with patellofemoral arthritis. The risk of postoperative iatrogenic medial patellar instability is not negligible but appears to be reduced by opting for LL over LR.
Using isolated LL and LR for patients with PCS is a viable option to reduce contact pressure on the lateral facet of the patella. The patients within the studies analyzed here all experienced significant improvement both by objective clinical measures and by validated PROMs. Identifying the ideal PCS patient LL or LR remains a challenge, though, as avoiding iatrogenic medial instability must be prioritized. Song et al. found in a systematic review of 300 knees who underwent LR, that 57% of them developed iatrogenic medial patellar instability.18 In a patient population with PCS, it may be useful to rule out other anatomic variants contributing to increased contact causing patellofemoral pain. For example, Massada et al. identified. Increased Q angle as a potential contributor to patellofemoral pain.19 Working to isolate a tight lateral retinaculum as the source of patellofemoral pain should be an important element in the decision to proceed toward isolated LR or LL for these patients.
Additionally, preoperative assessment of medial translation can be a valuable physical exam finding when considering LR or LL. Patients without limitations in medial translation may not be ideal candidates for LR or LL as their lateral retinaculum may not be tight enough to warrant the procedure. Song et al. found that patients without a tight lateral retinaculum preoperatively were more likely to develop iatrogenic medial instability.18 Pagenstert et al. included a medial patellar glide of less than one quadrant in their definition of lateral patellar hypercompression syndrome.13 Even in patients meeting this definition preoperatively, 36% of those who underwent isolated LR experienced postoperative medial instability. However, those who underwent isolated LL had zero events of postoperative medial instability.13 Thus, in addition to consideration of medial patellar translation, opting for LL rather than LR can also reduce the risks of iatrogenic medial instability.
For patients with preexisting patellofemoral arthritis, isolated LR provided beneficial outcomes, improving pain and Kujala scores. Calpur et al. demonstrated that articular cartilage damage of both the lateral facet and lateral femoral condyle increased with age in their PCS patients.7 Therefore, increased contact pressures experienced as a result of a tight lateral retinaculum may contribute to the development of or rate of progression of patellofemoral arthritis. If LR or LL can assist in alleviating some of this contact pressure, perhaps it could be used as a tool in decelerating cartilage damage. Among the patellofemoral arthritis patients investigated in Fosco et al., younger patients demonstrated significantly higher postoperative PROMs and superior improvement in PROMs.16 Perhaps this is a result of improving patellofemoral biomechanics before higher levels of articular cartilage damage have been sustained. Pohlig et al. found that isolated LR for patients with isolated lateral retinacular tightness improved biomechanics by increasing the patellofemoral contact area.20 This likely helps to spread the contact pressure of the joint, relieving the force on the lateral facet. Reducing contact pressure on damaged articular surfaces and shifting weight-bearing surfaces is the goal of other procedures like distal femoral and high tibial osteotomies.21,22 Further investigation into a potential role for isolated LR or LL in the management or prevention of patellofemoral arthritis is warranted to clarify any protective effect on patellofemoral joint cartilage.
This study is not without limitations. With only 7 studies, the subject group size is small; especially for patellofemoral arthritis and patellofemoral arthrofibrosis, both of which were only covered by one study. Furthermore, multiple studies did not explicitly address the lack of or presence of complications, making it difficult to ensure all relevant complications were included. A major limitation notable for our study is the operative indications, techniques, and outcomes of each of the included studies. As LL or LR are both usually concomitant procedures, isolated versions are not frequently performed, with open and arthroscopic versions used in each. Indications for the procedure are often for PCS, which itself has varying features that are not widely standardized. As LL or LR are newer procedures for PCS or patellofemoral arthritis, many of the included studies are non-randomized and smaller studies including case series. These factors all impact the applicability, reproducibility, and general strength of this study. Future studies should be performed investigating these important aspects of this procedure to provide high level evidence for review. Due to study heterogeneity and level of evidence, results could not be pooled and no meta-analysis could be performed.
5 Conclusion
Isolated LR and LL are viable options for the management of LPCS, anterior knee pain, and postoperative patellofemoral arthrofibrosis that lead to improvements in PROMs. Medial patellar instability is a feared complication of LR/LL but appears to be more likely in patients undergoing LR.
Authors’ contributions
Cailan L Feingold BS1 – Idea generation, Original manuscript writing.
Eric H Lin BA1- Idea generation, Original manuscript writing.
Brandon A Young BS2 – Data collection.
Ji S. Chin BS MS1 – Data Collection.
Andrew B Barcenas BS1 – Manuscript editing and submission.
Austin V Stone MD PhD2 – Oversight and Idea generation.
Joseph N Liu MD1– Oversight and Idea generation.
Patient consent statement (if applicable)
N/A.
Permission to reproduce material from other sources (if applicable)
N/A.
Ethics statement
N/A.
For clinical trials (if applicable)
N/A.
Level of evidence
LOE IV.
Funding
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
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