Lateral Retinacular Lengthening Research Articles

Medial Patellofemoral Ligament Reconstruction With Concomitant Tibial Tubercle Osteotomy

Background: Patellar instability, often associated with medial patellofemoral ligament rupture, is prevalent in adolescents. Risk factors include trochlear dysplasia, patella alta, abnormal patellar tilt, and increased tibial tubercle to trochlear groove (TT-TG) distance. Indication: A variety of surgical options are available for addressing patellar instability, and the selection of each technique should be tailored to the unique pathoanatomy of each patient. Medial patellofemoral ligament reconstruction (MPFLR) is indicated for patients with patellar instability, and tibial tubercle osteotomy (TTO) is indicated for patients with a TT-TG >20 mm. Technique Description: An anterior midline incision is performed to expose the patella, patellar tendon, and tibial tubercle. Diagnostic arthroscopy is performed to assess patellar engagement and cartilage integrity, followed by the TTO. Three guidewires are placed with 15° of obliquity, to guide a 6-cm osteotomy, from medial to lateral and from proximal to distal. A distal cortical hinge must be left intact. A 15-mm medial resection of the tibial tubercle is performed to avoid protrusion against the skin, which is followed by medialization of the tubercle and fixation with K-wires until dynamic testing ensures proper alignment and definitive fixation is achieved with cannulated headless screws. A lateral retinacular lengthening is performed to balance patellar forces. MPFLR is executed using a semitendinosus allograft. The graft is anchored to the patella and drawn through a surgically created plane to the medial femoral condyle. The femoral tunnel is created under fluoroscopy guidance, and the graft is then passed and secured. Graft tension and patellar mobility are adjusted according to dynamic testing. Once patellar stability is achieved and maintained through range of motion, the graft is then fixed. Results: Patients can expect improved clinical outcomes with a high return-to-sports rate following both isolated MPFLR and concomitant TTO. The combination of MPFLR + TTO significantly reduces revision rate, compared to isolated MPFLR in patients with increased TT-TG distance, and enhances postoperative patellofemoral tracking. Discussion/Conclusions: MPFLR + TTO improves patellofemoral tracking and corrects patellar instability, substantially improving postoperative outcomes compared to MPFLR alone. Patients with patellar instability and an increased TT-TG may be effectively treated with MPFLR + TTO. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Paper 35: Number of Patellar Dislocation Events are Associated with Increased Chondral Damage of the Trochlea: data from the JUPITER group

Objectives: Patellofemoral instability (PFI) is frequently associated with chondral injuries to the patella and trochlea. Though several radiographic and intra-operative studies have demonstrated a link between patellar dislocation and chondral injury, the influence of the number of patellar dislocation events on the presence of chondral wear and severity is not established. This study aimed to understand the association between the number of patellar instability events and chondral damage observed directly in a large patient population undergoing patellar stabilization procedures. Methods: This was a retrospective review of the prospective multi-center Justifying Patellar Instability Treatment by Results (JUPITER) cohort. All patients undergoing primary surgical procedures to address PFI from 12/2016 to 9/2022 with a recorded number of patellar dislocations and detailed intra-operative assessment of the articular cartilage were included. Cartilage lesions were classified using the International Cartilage Repair Society (ICRS) classification, where ICRS grades 2 to 4 are defined as abnormal or severely abnormal. The number of dislocation events was grouped into 1-2, 3-5, and >5 dislocations. Continuous and categorical variables were compared using independent t-tests and chi-squared tests, respectively with multivariable regressions used to control for demographic characteristics potentially influencing cartilage wear. A significance threshold of p<0.05 was used. Results: A total of 938 patients at mean age 16.2 ± 3.8 years (range 5.1-35.0 years, 61.4% female patients) undergoing PFI procedures were included. Of these, 580 (61.8%) demonstrated a chondral injury. The most commonly affected region was the patella (n = 498, 53.1%) followed by the femoral condyles (n = 148, 15.8%), and trochlea (n = 109, 11.6%), with 83 (8.8%) patients having lesions located on both the patella and trochlea (Table 1). MPFL reconstruction was performed in 861 (91.8%) cases (Table 2), with other commonly performed procedures including patellofemoral chondroplasty (n = 388, 41.4%) and lateral retinacular lengthening or release (n = 255, 27.2%). Patients with fewer dislocations more frequently underwent fixation of an osteochondral fragment (1-2: 19.5%, 3-5: 7.6%, >5: 1.7%, p<0.001). There were no differences in the presence (p=0.209) or grade (p=0.716) of patellar chondral lesions based on dislocation number (Table 3). Patients with >5 patellar dislocations more frequently had a trochlear chondral lesion (19.8%) compared to the groups with fewer dislocations (1-2: 8.4%, 3-5: 13.0%, p<0.001). A greater number of dislocations was also associated with a higher proportion of abnormal (ICRS grades 2-4) trochlear lesions (>5: 15.3%, 3-5: 11.7%, 1-2: 7.6%, p=0.009), and the mean trochlear ICRS grade was significantly greater for the highest dislocator group (>5, mean 0.45 ± 0.99, p=0.023) compared to those with fewer dislocations (1-2: mean 0.24 ± 0.84, 3-5: mean 0.34 ± 0.93). Combined patellar and trochlear lesions were also higher in the most frequent dislocation group (>5 dislocations: 15.8%, 3-5: 9.9%, 1-2: 6.1%, p<0.001). In multivariable regression accounting for age, sex, BMI, and dislocation count, a dislocation count >5 was the only variable significantly predictive of the presence of a trochlear chondral lesion (OR 2.16, 95% CI 1.36-3.43, p=0.001). Both age in years (OR 1.11, 95% CI 1.06-1.16, p<0.001) and BMI (OR 1.05, 95% CI 1.02-1.07, p<0.001) were predictive of a patellar lesion, while both age in years (OR 1.07, 95% CI 1.01-1.13, p=0.017) and dislocation count >5 (OR 2.25, 95% CI 1.35-3.75, p=0.002) were predictive of the presence of both a patellar and trochlear lesion. Conclusions: This study demonstrates that an increased number of patellofemoral dislocation events is associated with more frequent trochlear and combined patellar/trochlear chondral damage with higher injury severity. Specifically, a dislocation count >5 is associated with a greater than 2-fold increase in the number of trochlear chondral injuries, which are of higher severity potentially requiring surgical management. Conversely, patients with fewer dislocation events were more likely to undergo osteochondral fracture fixation, which may have driven earlier operative intervention in this group. This is the first, large prospective study to demonstrate that multiple patellar dislocations can result in increased and more severe chondral damage.

Evaluation of Differences in Patellar Height After Patellar Stabilization Procedures Not Intended to Address Patella Alta: A Multicenter Study.

Recent studies have reported conflicting results as to whether isolated medial patellofemoral ligament reconstruction (MPFLr) leads to decreased patellar height. To investigate if patellar stabilization surgery not intended to address patella alta influences patellar height. Cohort study; Level of evidence, 3. A multicenter retrospective chart review was conducted, and patients who underwent MPFLr, medializing tibial tuberosity osteotomy (TTO), and/or trochleoplasty between 2016 and 2020 were included. The Caton-Deschamps index (CDI) was calculated from radiographs obtained preoperatively, 2 weeks postoperatively, and 3 months postoperatively. The preoperative CDI value was compared with the 2-week postoperative and 3-month postoperative values according to stabilization procedure (isolated MPFLr, isolated TTO, MPFLr + TTO, MPFLr + trochleoplasty, and MPFLr + trochleoplasty + TTO) using the paired t test. Analyses of the 1-bundle versus 2-bundle MPFLr technique and the presence of lateral retinacular release or lateral retinacular lengthening were conducted on the isolated MPFLr and combined MPFLr + TTO cohorts. A total of 356 knees were included. Statistically significant pre- to postoperative decreases in CDI were seen in all stabilization procedures analyzed (P≤ .017 for all). Within the isolated MPFLr cohort, this significant decrease was seen at 2 weeks postoperatively with the 2-bundle technique (ΔCDI = -0.09; P < .001) but not with the 1-bundle technique (ΔCDI = -0.01; P = .621). The different surgical techniques analyzed in the current study affected patellar height, even when a distalizing TTO was not performed. The decrease was dependent on surgical technique, with a 2-bundle MPFLr leading to a statistically significant decrease and a 1-bundle MPFLr effecting no change.

Lateral Lengthening and Lateral Release

The lateral retinaculum is a complex, layered structure that is the primary constraint to medial translation of the patella. Patients can develop patellar hypercompression syndrome and arthritis of the lateral patellofemoral joint from an overly tight lateral retinaculum. Conservative treatments include physical therapy and bracing but if relief is not achieved, surgical treatment in the form of lateral retinacular lengthening or release may alleviate symptoms. This chapter provides a thorough background of the risks, indications, outcomes, and techniques regarding treatment of the lateral retinaculum.

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.

Descriptive Epidemiology of a Surgical Patellofemoral Instability Population of 492 Patients.

Background:Patellofemoral instability (PFI) occurs most commonly in pediatric and adolescent patients, with evolving indications for surgery and changes in surgical techniques over the past decade.Purpose:To characterize the demographic, clinical, and radiologic characteristics of a large cohort of patients undergoing PFI surgery and investigate longitudinal trends in techniques utilized over a 10-year period at a tertiary-care academic center.Study Design:Case series; Level of evidence, 4.Methods:Electronic medical records of patients younger than 25 years of age who underwent primary surgery for lateral PFI from 2008 to 2017 at a single center by 1 of 5 different sports medicine surgeons were retrospectively reviewed. Demographic, clinical, and radiographic parameters of instability were analyzed. Routine surgical techniques included medial retinacular plication/reefing/repair (MRP), medial patellofemoral ligament reconstruction (MPFLR), tibial tubercle osteotomy (TTO), or a combination thereof, with or without lateral retinacular release (LR) or lateral retinacular lengthening (LRL). Exclusion criteria, selected for potentially altering routine surgical indications or techniques, included fixed/syndromic PFI, a formally diagnosed collagen disorder, cases in which a chondral/osteochondral shear fragment underwent fixation or was >1 cm in diameter, and body mass index >30 kg/m2.Results:Of the 492 study patients (556 knees; 71% female; median age, 15.2 years; 38% open physes), 88% were athletes, with the most common sports participated in being soccer, basketball, dance, football, gymnastics, and baseball/softball. While 91% of the cohort had recurrent dislocations, the 9% with primary dislocations were more likely to have small osteochondral fractures/loose bodies (P < .001). Female patients were younger (P = .002), with greater patellar tilt (P = .005) than male patients. Utilization of MPFLR and TTO increased significantly over the study period, while use of MRP+LR decreased.Conclusion:Most patients younger than 25 years of age who underwent PFI surgery were skeletally immature, female, and athletes and had recurrent dislocations. The <10% who had primary dislocations and underwent surgery were likely to have osteochondral fractures. Surgical techniques have changed significantly over time, with increasing use of TTO and MPFLR, while the use of MRP+LR/LRL has significantly decreased.

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.

Technique Variation for MPFL Reconstruction in Skeletally Immature Patients: Data from the Jupiter Cohort

Background:Management approaches and surgical techniques, when applied for pediatric and adolescent patellofemoral instability (PFI), continue to lack clear clinical guidelines and indications. Medial patellofemoral ligament reconstruction (MFPLR) is among the most popular surgical options. However, variation in technique remains significant, particularly in skeletally immature sub-populations.Purpose:The purpose of this study was to examine the variation in MPFLR technique in skeletally immature patients within a cohort of 20 orthopedic surgeons with different experience levels and specialty training backgrounds. Methods: All operative records of skeletally immature patients from 2016 to 2021 were retrieved from the JUPITER cohort, a multi-center prospective study involving 13 different tertiary care academic centers. Patients who underwent a primary single-stage MPFLR were evaluated in this study. Demographic information and operative details were collected for each knee.Results:Of the 306 knees, 205 (53% female, 47% male) met inclusion criteria and comprised the final cohort (Table 1). The average age was 13.6 ± 1.8 yrs (5.1-19.0). The initial injury mechanism was of a non-contact nature in 73% and a result of contact in 17%. 47% of surgeons utilized autograft while 53% utilized allograft. Suture anchors (including small tenodesis screws) were the most popular patellar fixation technique (61%), followed by the use of tunnel under a bone bridge (37%). The majority of surgeons utilized 2 suture anchors (59%). Interference screws were the most popular femoral fixation technique (84%), followed by suture anchors (12%). The majority of surgeons used either 1 interference screw 97(%) or 1 suture anchor at the femur (96%). In addition to MPFLR, 15% of patients underwent osteochondral fracture treatment: 36% underwent loose body removal, while 61% underwent fixation. Lateral Retinacular Release was performed in 13% of cases, and lateral retinacular lengthening was performed in 2%. 10% of patients underwent concomitant hemi-epiphysiodesis for genu valgum, 3% underwent medial quadriceps tendon-femoral ligament reconstructions, and 3% underwent a Grammont realignment (patellar tendon medialization) procedure.Conclusion:Variation in different aspects of MPFLR technique is substantial among this cohort of orthopedic surgeons. Given the well-established importance of decreasing variation for healthcare cost containment and optimization of outcomes, comparative studies and sub-stratified analyses are needed to better elucidate the most favorable techniques and their components.Table 1.Demographic and Surgical Data

Patellar MACI With Tibial Tubercle Osteotomy

Background: Chondral pathology is frequently encountered during knee arthroscopies with a prevalence rate of 63% to 66%. Prior studies have demonstrated that unaddressed or excised fragments result in poor knee function and arthritis. As a result, chondral-related procedures have increased in popularity, and now more than 200,000 procedures are performed annually. Indications: We present a case of an active 32-year-old woman, prior collegiate basketball player, with persistent left knee pain noted to have a full-thickness patellar articular cartilage defect and maltracking. Technique: A patellar autologous matrix-induced chondrocyte is implanted with a concomitant tibial tubercle osteotomy (TTO) and lateral retinacular lengthening. Results: At 9 weeks, the patient had no knee pain with full range of motion symmetric to the contralateral side while slowly progressing with quadriceps strengthening. Discussion/Conclusion: Successful outcomes addressing large patellar chondral defects and maltracking can be achieved with matrix autologous chondrocyte implantation and concomitant TTO with lateral retinacular lengthening.

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.

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.

Recent advances and future trends in patellofemoral instability

Patellofemoral joint instability (PFJI) is a challenging condition affecting primarily young patients. It can be both physically and mentally disabling. There are numerous factors which contribute to stability of the patellofemoral joint and thorough clinical assessment and appropriate radiological investigations are essential in determining which risk factors need to be corrected to prevent further episodes of dislocation. One of the key operations utilized in the management of PFJI is medial patellofemoral ligament (MPFL) reconstruction, to restore the patellar restraint against lateral translation. The complications that can result from MPFL reconstruction can be largely divided into complications resulting from technical error or selection of operation for a patient’s specific risk factors. Some risk factors of PFJI can precipitate the need for additional operations being performed alongside MPFL reconstruction, including trochleoplasty, lateral retinacular lengthening, and tibial tuberosity osteotomy. Failure to identify the need for concurrent operations will result in persistent PFJI. This update article will outline the approach to assess a patient presenting with PFJI and the risk factors which should be identified and corrected. It will also cover the various management options with respect to these factors, with some important considerations for each.

Medial Patellofemoral Ligament Reconstruction and Lateral Retinacular Lengthening in the Skeletally Immature Patient

Patellar instability remains a ubiquitous and troublesome problem in orthopaedics and represents a challenge in the pediatric population. Reconstruction of the medial patellofemoral ligament (MPFL) has become a mainstay of patellar instability management in recent years. As with any procedure at or around the physes, there is concern among surgeons regarding safe placement of hardware and drilled tunnels. The authors describe a technique for anatomic MPFL reconstruction with the aid of fluoroscopic guidance to maintain a “safe zone” without violating the distal femoral physis. This technique allows for reliable MPFL reconstruction in the skeletally immature population with concomitant lateral lengthening, while requiring only minor deviations from the procedure in a skeletally mature patient.

Trochleoplasty, Medial Patellofemoral Ligament Reconstruction, and Open Lateral Lengthening for Patellar Instability in the Setting of High-Grade Trochlear Dysplasia

Trochlear dysplasia is the most commonly encountered pathoanatomy in patients who present with patellar instability. Outcomes of trochleoplasty procedures have shown low rates of recurrent instability and high patient-reported outcome scores. This article describes a “thin-flap” groove-deepening trochleoplasty combined with medial patellofemoral ligament reconstruction with a gracilis allograft and lateral retinacular lengthening to treat recurrent patellar instability due to high-grade trochlear dysplasia. This technique can obviate tibial tubercle osteotomy by normalizing the position of the trochlear groove and, subsequently, decreasing the tibial tubercle–to–trochlear groove distance.

Medial Patellofemoral Ligament Repair Versus Reconstruction for Recurrent Patellar Instability: Two-Year Results of an Algorithm-Based Approach.

Background:Patellar instability remains a challenging problem for both the patient and surgeon. Medial patellofemoral ligament (MPFL) repair has historically had poor results, and due to this, there is currently a trend toward reconstruction.Purpose/Hypothesis:This study was undertaken to investigate experience with repair versus reconstruction of the MPFL using a multifactorial treatment algorithm approach. Our hypothesis was that there will be no significant difference in outcome scores between patients in the MPFL repair and reconstruction groups.Study Design:Cohort study; Level of evidence, 2.Methods:A total of 24 patients with recurrent (≥2) lateral patellar dislocations were included. All had failed nonoperative treatment for more than 6 months, and all were observed for a minimum of 2 years. First, magnetic resonance imaging (MRI) was used to find the location of the MPFL tear. A tilt test was used to determine whether a lateral retinacular lengthening was required to allow the patella to have neutral tilt. If the MRI showed a tibial tubercle–trochlear groove (TT-TG) distance greater than 20 mm, a tibial tubercle osteotomy (TTO) was recommended. An MPFL reconstruction was performed if the entire ligament was inadequately visualized on MRI or if it was torn from both insertion sites. Failure was defined as recurrent lateral patellar instability after surgery. As a secondary outcome measure, Knee injury and Osteoarthritis Outcome Score (KOOS), Lysholm score, and Tegner score were calculated.Results:All patients were evaluated with a mean follow-up of 51 months (range, 25-79 months). Sixteen patients initially underwent MPFL repair, 8 underwent reconstruction, and 3 also underwent TTO. MPFL reconstructions were performed in all patients who underwent TTO. One MPFL repair was to the anatomic femoral origin and 15 were to the patellar insertion corresponding to the site of tearing on MRI. A lateral retinacular lengthening was performed in 21 patients. There was 1 failure in the repair group (6%) and none in the reconstruction group. However, the patient who failed had a TT-TG distance of 26 mm but refused a TTO. She subsequently underwent revision with a TTO and MPFL reconstruction and did not have any further instability events. There were no significant differences between groups for any of the secondary outcome scores.Conclusion:Using an algorithm-based approach, MPFL repair or reconstruction may lead to clinically acceptable results at 2-year follow-up.

Patellofemoral Osteochondral Allograft Transplantation

Patellofemoral (PF) cartilage defects are common. They may result from instability, incongruity between the patella and trochlea, repetitive overload (microtrauma), or direct impact (macrotrauma). If exhaustive conservative management fails to resolve symptoms of disabling anterior knee pain with activities of daily living, surgical treatment may be considered. There are 3 main indications for osteochondral allograft transplantation: cartilage defects that are associated with extensive abnormalities of the subchondral bone or frank bone loss that are expected to compromise surface procedures such as autologous chondrocyte implantation; cartilage defects that are associated with severe trochlear dysplasia; and PF osteoarthritis in young patients who are not candidates for arthroplasty. Osteochondral allograft transplantation is performed using 1 of the 2 following techniques, depending on the location and extent of cartilage damage being addressed. The dowel or press-fit technique utilizes a cylindrical reamer and coring reamer system to fashion a dowel and recipient site with a diameter ranging from 15-35 mm. The shell technique is an alternative, which addresses very large defects in which the chondral defect area is removed along with bone with a saw using the same plane(s) as for prosthetic resurfacing (total knee arthroplasty or PF arthroplasty). Careful assessment of PF kinematics and anatomy (or pathokinematics and pathoantatomy) are the key to optimizing success. In light of these factors, associated procedures (such as tibial tuberosity osteotomies, medial PF ligament reconstruction, or lateral retinacular lengthening) are very common in PF cartilage repair, especially with bipolar grafts. With attention to detail and technique, successful outcomes may be achieved in many patients.

Author's Reply

First, we feel honored receiving interest by such an authority in the field of orthopedic knee surgery as Dr. Merchant. However, we disagree with his statement that the turn-up sign to 90° was quickly discarded or never adopted after being described in 1986.1Henry J.H. Goletz T.H. Williamson B. Lateral retinacular release in patellofemoral subluxation. Indications, results, and comparison to open patellofemoral reconstruction.Am J Sports Med. 1986; 14: 121-129Crossref PubMed Scopus (70) Google Scholar No evidence or recommendation was available in the listed international publications when we started our prospective study in 2008. In contrast, the current “state-of-the-art” technique in 2008 as described in Master Techniques in Orthopaedic Surgery: Reconstructive Knee Surgery pointed out that “a turn-up sign of 90° should be performed to assure adequate release” (Figure 1.9, page 9).2Gasser S. Cucchetti B. Arthroscopic lateral release of the patella with radiofrequency ablation.in: Jackson D. Master techniques in orthopaedic surgery: Reconstructive knee surgery. Ed 3. Lippincott, Williams & Wilkins, Philadelphia2008: 1-11Google Scholar The authors of this book and article are renowned chairmen and experts in the field of orthopaedic surgery in the United States, but obviously have not been aware of the potential risk of the 90° turn-up sign during release. In contrast, Dr. Merchant mentioned the book chapter published by Ewing3Ewing J.W. Arthroscopic patellar shaving and lateral retinacular release.in: McGinty J.B. Operative arthroscopy. Raven, New York1991Google Scholar in 1991 that recommended a turn-up of 60°. Unfortunately, this book chapter is not available in the listed scientific material for international specialists. In addition, we could not find Dr. Merchant's personal publication in the available literature that gives the recommendation to limit the turn-up sign to less than 90°. We immediately published our results and our recommendation to reduce the turn-up sign to 70° (included in the “Discussion” section of our article).4Pagenstert G. Wolf N. Bachmann M. et al.Open lateral patellar retinacular lengthening versus open retinacular release in lateral patellar hypercompression syndrome: A prospective double-blinded comparative study on complications and outcome.Arthroscopy. 2012; 28: 788-797Abstract Full Text Full Text PDF PubMed Scopus (66) Google Scholar We absolutely agree that the publication of Dr. Merchant's letter together with our study will help to correct this deficiency of knowledge in US and international orthopaedic societies. Finally, we really appreciate this kind of discussion based on letters to the editor, because it points out minor details that turn out to be most critical in obtaining good or bad results. However, we will not repeat the study with a turn-up sign of 60° or 70° because we believe, in our Level II evidence, that lateral retinacular lengthening will give better results than simply cutting the lateral retinaculum because of preserved muscle, iliotibial band, and retinacular fiber connection despite the extent of the turn-up sign used. We hope other readers will take the opportunity to share in our discussion and follow our consensus recommendation for a limited turn-up sign during lateral retinacular release. Is It Lateral Retinacular Lengthening Versus Lateral Retinacular Release or Over-Release?ArthroscopyVol. 29Issue 3PreviewAs the first author to publish about the lateral release, in 1974,1 I feel an obligation to comment on the article “Open Lateral Patellar Retinacular Lengthening Versus Open Retinacular Release in Lateral Patellar Hypercompression Syndrome: A Prospective Double-Blinded Comparative Study on Complications and Outcome” by Pagenstert et al.2 in the June 2012 issue of Arthroscopy. The abstract describes a well-designed prospective study with the results clearly favoring lengthening compared with release. Full-Text PDF

Lateral Retinacular Lengthening

Lateral Retinacular Lengthening

Role of Lateral Release in Patella Femoral Instability

ABSTRACT Lateral retinacular release has been used and abused as a primary form of treatment for a variety of patellar femoral disease states. Indications for isolated lateral retinacular release are limited. For those patients with radiographic evidence of isolated patellar tilt and clinical evidence of anterior knee pain with tight lateral retinaculum and limited medial patellar translation, lateral retinacular release has a high success rate. The technique of lateral retinacular lengthening is evolving and has theoretical advantages over lateral retinacular release in not sacrificing normal anatomy, maintaining a lateral restraint and preventing the potential post lateral retinacular release complication of medial patellar instability.

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

A prospective, randomized study was performed to compare the results of arthroscopic lateral retinacular release (Group I) with those of open lateral retinacular lengthening (Group II). The study included eighty-six patients (eighty-six knees) who had had pain in the anterior peripatellar aspect of the knee and lateral patellar tilting (rotational malalignment), as seen on Merchant tangential patellofemoral radiographs, that had not improved after participation in a structured rehabilitation program for the quadriceps and the hamstrings for a minimum of six months. The mean duration of follow-up after the operative procedures was forty-six months (range, two to six years). At the time of the latest follow-up evaluation, forty (93 per cent) of the forty-three patients in Group I and all forty-three (100 per cent) of the patients in Group II had resumed the level of athletic activity that they had engaged in before the onset of symptoms (p = 0.08, analysis of variance). With the numbers available for study, no significant difference could be detected between the groups with regard to deficits in the range of motion, atrophy (the circumference) of the thigh, operative or postoperative complications, or the need for subsequent operative procedures. Additionally, no significant difference could be detected between the groups with regard to the results of open or closed-chain testing with an isokinetic dynamometer. According to the knee-rating system of Lysholm and Gillquist as modified by Tegner and Lysholm, thirty-three knees (77 per cent) in Group I had a score of 80 points or more compared with thirty-eight knees (88 per cent) in Group II. Six knees (14 per cent) in Group I had a score of less than 70 points compared with no knees in Group II. The difference in the knee ratings between the two groups was significant (p = 0.028, analysis of variance). Although there seemed to be a definite trend toward improved function of the knee in association with a longer duration of follow-up, no significant association could be detected between the duration of follow-up and improvement in the outcome measures in either group.