Medial Patellofemoral Ligament Reconstruction Using Suture Tape for Patellofemoral Joint Instability

Synthetic suture tape for medial patellofemoral ligament reconstruction is an effective treatment for complex paediatric patellofemoral instability

PURPOSE

To assess the outcomes of medial patellofemoral ligament (MPFL) reconstruction using synthetic suture tape in paediatric patients with patellofemoral instability (PFI).

METHODS

This ambispective comparative study, conducted from 2014 to 2022, included paediatric patients who underwent MPFL reconstruction with synthetic suture tape and had a minimum follow-up of 1 year. Pre- and postoperative clinical and functional outcomes, patient satisfaction and complications were assessed.

RESULTS

The study comprised 22 patients (29 knees), with a median age at surgery of 14.4 years (interquartile range [IQR] 10.9-16.7) and a median follow-up of 46.5 months (24.7-66). Notably, 13 knees (44.8%) had open growth plates at the time of surgery. The cohort included patients with Down syndrome (3 patients), Ehlers-Danlos (2), arthrogryposis (1), generalized joint hypermobility (8) and previous unsuccessful PFI surgeries (8). Concomitant procedures were performed on 16 knees. Postoperatively, improvements were observed in all but one patient, who reported residual pain. There were two other complications: one suture-tape rupture and one surgical wound infection. Functional scores significantly improved: Kujala, +14 points (7-29) (p < 0.001); IKDC, +10.5 points (5.2-25.3) (p < 0.001); Tegner, +2 points (0-4) (p < 0.001); Lysholm, +15 points (0-37.5) (p < 0.001). Most patients achieved excellent outcomes by Crosby-Insall criteria (21 patients, 72.4%) and reported high satisfaction (23 patients, 79.3%).

CONCLUSIONS

MPFL reconstruction using synthetic suture tape is a viable and effective treatment for paediatric patients with PFI, particularly for those with connective tissue disorders, generalized joint hypermobility or past surgical failures, significantly enhancing clinical and functional outcomes with an acceptable complication rate.

LEVEL OF EVIDENCE

Level IV.

Arthroscopic medial patellofemoral ligament reconstruction with polyethylene suture combined with medial retinaculum plication for the treatment of acute patellar dislocation in young and middle-aged patients with a follow-up of at least 2 years

PURPOSE

The purpose of this study was to propose a surgical technique for arthroscopic medial patellofemoral ligament (MPFL) reconstruction with polyethylene suture combined with medial retinaculum plication and to evaluate the efficacy of this surgical technique in the treatment of acute patellar dislocation.

METHODS

Clinical data of patients with acute patellar dislocations treated with arthroscopic MPFL reconstruction with polyethylene tape (FiberTape) combined with medial support band compression were analyzed retrospectively from January 2018 to January 2021. The mean age of the patients was 25.15 ± 4.66 years; the mean follow-up time was 27.5 (24-36) months. Clinical evaluation consisted of apprehension test results, patellar extrapolation test results, Lysholm score, Kujala score, and IKDC score, the Patellar lateral shift distance and patellar tilt angle (PTA) measured by CT scan.

RESULTS

All patients had no recurrent patellar dislocation or subluxation after surgery, and the apprehension test was negative. In all patients, the Kujala score (36.0 ± 9.9 vs. 98.2 ± 3.1), the IKDC score (48.6 ± 7.0 vs. 90.6 ± 4.4) and the Lysholm score (32.8 ± 10.4 vs. 96.7 ± 3.1) had improved at the 24-month follow up (P < 0.05). In addition, PTA was significantly lower at the 12-month follow-up and 24-giving-month follow-up compared to the preoperative period (P < 0.05, Table 2). The patellar lateral shift distance decreased from 14.94 ± 6.11 mm preoperatively to 3.00 ± 1.40 mm (12-month follow up) and 3.26 ± 1.37 mm (24-month follow up), respectively.

CONCLUSION

Arthroscopic MPFL reconstruction with polyethylene suture combined with medial retinaculum plication is a safe and reliable surgical technique for the treatment of acute patellar dislocation in young and middle-aged patients.

LEVEL OF EVIDENCE

Level III, Therapeutic Study.

Medial Patellofemoral Ligament Augmentation Repair for Primary Patellar Dislocation With Concomitant Chondral or Osteochondral Injury in Children and Adolescents: Outcomes at Minimum 2-Year Follow-up

Background

Treatment of primary patellar dislocation (PPD) with chondral or osteochondral injury without patellar stabilization in the adolescent population may lead to unsatisfactory outcomes. Surgical treatment, with or without traditional medial patellofemoral ligament (MPFL) reconstruction, is a topic of interest.

Purpose

To compare postoperative outcomes and rates of patellar redislocation and return to the operating room (OR) in patients who sustained a PPD with chondral or osteochondral injury and were surgically treated with versus without suture tape augmentation repair of the MPFL.

Study Design

Cohort study; Level of evidence, 3.

Methods

Adolescents who sustained a PPD with chondral or osteochondral injury confirmed via magnetic resonance imaging (MRI) and who were treated by a single surgeon between January 2009 and November 2020 were retrospectively reviewed. Patients were grouped into those who underwent chondral or osteochondral treatment with suture tape augmentation repair of the MPFL (ST group; n = 20) and those who did not have suture tape augmentation or repair (no-ST group; n = 20; 11 patients within the no-ST group did undergo medial imbrication). Demographic characteristics, postoperative knee range of motion, pre- and postoperative radiographic measurements, and preoperative MRI parameters were recorded, and minimum 2-year patient-reported outcomes were collected. Data were compared between the ST and no-ST groups.

Results

The mean patient age was 15.02 years (range, 12.64-17.61 years) in the ST group and 14.18 years (range, 10.56-16.38 years) in the no-ST group, with a mean follow-up of 3.63 years (range, 2.01-6.11 years) in the ST group and 4.98 years (range, 2.23-9.03 years) in the no-ST group. Significantly more patients returned to the OR in the no-ST group compared with the ST group (7 [35%] vs 0 [0%]; P = .008). Further patellar stabilization with an MPFL allograft (n = 5) and manipulation under anesthesia (n = 2) were reasons for returning to the OR. There were no redislocation events in the ST group.

Conclusion

Treating PPDs with chondral or osteochondral injury using suture tape to augment and repair the MPFL has promising advantages over not repairing it-including lower rates of postoperative patellar instability and return to the OR.

Arthroscopically Assisted Double-Bundle Medial Patellofemoral Ligament Augmentation With Physeal-Sparing Suture Fixation for Recurrent Patellar Dislocation in Skeletally Immature Patients

Recurrent patellar dislocation is a common patellofemoral disease that affects active adolescents. The optimal surgical treatment of recurrent patellar dislocation in skeletally immature patients remains controversial. This Technical Note describes an arthroscopically assisted double-bundle medial patellofemoral ligament (MPFL) augmentation. Orthocord suture, with ideal strength and partial bioabsorbable characteristics, is used as the stabilizer to augment and protect the native MPFL during its biological healing. Under an arthroscope, patellar tunnels are created with Kirshner wire at the upper third point of the medial articular margin and the midpoint of the proximal articular margin. A physeal-sparing transosseous suture fixation technique is applied at the femoral attachment. Two femoral tunnels are made with half-circle cutting needle, which is pierced into the femoral origin of the MPFL and exits the posterior femoral cortex. After dynamic assessments of knee range of motion and patellofemoral congruence, free ends of the Orthocord suture bundle are tied together at the external opening of the femoral tunnel. Transosseous suture fixation balances the requirements of anatomic restoration, reliable fixation, and physeal preservation, and thus may provide a promising alternative to current algorithm of addressing recurrent patellar dislocation in pediatric population.

No Difference in Pullout Strength Between a Bio-inductive Implant and a Semitendinosus Tendon Graft in a Biomechanical Study of Medial Patellofemoral Ligament Repair Augmentation

Purpose

To compare the pullout strength of a bio-inductive implant (BI) used to augment a medial patellofemoral ligament (MPFL) repair with the pullout strength of semitendinosus graft in a biomechanical cadaveric model.

Methods

Six matched pairs of cadavers (12 knees) were used in the biomechanical testing comparing semitendinosus tendon (Semi-T) versus a BI. The Semi-T was harvested from 1 of the matched pairs. A standard double-bundle technique using 2 sockets in the upper two-thirds of the patella 15 mm apart was performed. After docking of the graft into the patella, the patella was dissected free of soft tissues and potted into a fixture to allow mechanical pull parallel to the transverse axis of the patella. The construct was pulled to failure.

Results

There was no statistically significant difference in pullout strength (P = .77) between the BI group (249.3 ± 36.3 N) and Semi-T group (235.0 ± 113.6 N) double-bundle constructs. In the Semi-T group, 50% of the specimens (3 of 6 knees) failed via anchor pullout and a fourth specimen failed at the suture-anchor interface (16.7%), whereas in the BI group, 16.7% of the specimens (1 of 6 knees) failed by anchor pullout. Although the Semi-T group (49.5 ± 14.1 N/mm) showed significantly greater stiffness than the BI group (13.8 ± 0.6 N/mm, P < .01), pullout strength in the Semi-T group was highly variable: 50% of the specimens (3 of 6 knees) with semitendinosus constructs failed at 5 mm of displacement or less via graft or anchor pullout. Maximum load, displacement at failure, stiffness, and load at 5 mm were compared between the augmented and non-augmented control specimens using a 2-tailed non-equal variance Student t test. For all comparisons, P < .05 was considered to indicate a statistically significant difference.

Conclusions

In this biomechanical study, augmentation of an MPFL reconstruction using a common double-bundle technique with a BI had the same pullout strength as a semitendinosus graft using the same technique in cadaveric knees.

Clinical Relevance

MPFL repair after a patellar dislocation may be inadequate to restore the strength of the native MPFL and prevent recurrent patellar instability. Recurrent instability of the patella can result in progressive injury to the soft tissue and articular cartilage of the patella and femur. It is important to study the techniques used for MPFL repair to continually improve patient outcomes. Further testing of these additional techniques and clinical studies are needed to evaluate the implants used to augment MPFL repairs.

Tissue Augmentation Techniques in the Management of Ligamentous Knee Injuries

Despite early reports of high failure rates in knee ligament repair techniques resulting in favor of reconstruction, newer advances in surgical technology have shifted the attention back to repair with the addition of various tissue augmentation techniques. Ligament repair preserves proprioceptors in the native ligament and avoids autograft tendon harvest, minimizing the complications associated with donor site ruptures in reconstruction techniques. Tissue augmentation has been successfully used in knee ligamentous and tendon repair procedures, as well as in some upper extremity procedures. This study provides a clinical update on the surgical techniques, biomechanics, and outcomes with the application of various tissue augmentation techniques in the ligaments surrounding the knee joint.

Clinical Research Progress of Internal Brace Ligament Augmentation Technique in Knee Ligament Injury Repair and Reconstruction: A Narrative Review

Knee ligament injuries are most common in sports injuries. In general, ligament repair or reconstruction is necessary to restore the stability of the knee joint and prevent secondary injuries. Despite advances in ligament repair and reconstruction techniques, a number of patients still experience re-rupture of the graft and suboptimal recovery of motor function. Since Dr. Mackay's introduction of the internal brace technique, there has been continuous research in recent years using the internal brace ligament augmentation technique for knee ligament repair or reconstruction, particularly in the repair or reconstruction of the anterior cruciate ligament. This technique focuses on increasing the strength of autologous or allograft tendon grafts through the use of braided ultra-high-molecular-weight polyethylene suture tapes to facilitate postoperative rehabilitation and avoid re-rupture or failure. The purpose of this review is to present detailed research progress in the internal brace ligament enhancement technique of knee ligament injury repair as well as the reconstruction from biomechanical and histological research and clinical studies and to comprehensively assess the value of the application of this technique.

Comparison of patellar anchor fixation graft and graft through patellar tunnel reconstruction of medial patellofemoral ligament in the treatment of recurrent patellar dislocation: A protocol for a meta-analysis of comparative studies

BACKGROUND

Recurrent patellar dislocation (RPD) occurs in people who have their own patellofemoral dysplasia and who have not been properly treated after their first patellar dislocation. For RPD where conservative treatment is ineffective, medial patellofemoral ligament (MPFL) reconstruction is the first choice for surgical treatment, but there are various and controversial ways of MPFL reconstruction and fixation. Initially, more scholars adopted the patellar lateral tunneling (PT) approach to contain and stabilize the graft, but with the newer materials and techniques, some experts adopted the lateral patellar anchor fixation (AF) of the graft, which can avoid the collateral damage caused by the patellar lateral tunneling and can obtain the same definite efficacy. Therefore, a meta-analysis must be performed to provide evidence whether there is a difference between AF and PT reconstruction of the MPFL in the treatment of RPD.

METHODS

We will search, with no time restriction, without any restriction of language and status, the time from the establishment of the database to October 2022, on the following databases: PubMed (MEDLINE), Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, Chinese National Knowledge Infrastructure (CNKI), Wanfang Data (WF), Chinese Scientific Journals Database (VIP), and Chinese databases SinoMed (CBM) electronic databases. The electronic database search will be supplemented by a manual search of the reference lists of included articles. We will apply the risk-of-bias tool of the Cochrane Collaboration for randomized controlled trials to assess the methodological quality. Risk-of-Bias Assessment Tool for Non-randomized Studies was used to evaluate the quality of comparative studies. Statistical analysis will be conducted using RevMan 5.4 software.

RESULTS

This systematic review and meta-analysis will evaluate the functional outcomes of the two fixation modalities, AF and PT, in reconstructing MPFL for RPD.

CONCLUSION

The findings of this study will provide a basis for clinical judgment of whether there is a difference between the two forms of AF and PT reconstructed MPFL for RPD.

Soft-tissue fixation is not inferior to suture-anchor fixation in reconstruction of the medial patellofemoral ligament using a nonresorbable suture tape

PURPOSE

Reconstruction of the medial patellofemoral ligament (MPFL-R) with nonresorbable suture tape (FiberTape^®, FT) is becoming popular. Patella-side fixation of the FT can be performed with suture anchors or via soft-tissue fixation. The aim of this study was to investigate whether patella-side soft-tissue fixation can achieve equivalent primary stability compared to suture-anchor fixation.

METHODS

In ten human, fresh-frozen knee joint specimens (m/f 6/4; age 74 ± 9 a), the MPFL was identified and dissected near the femoral insertion site. In five knee joints, the MPFL-R using FT was performed with soft-tissue fixation at the patella (study group; SG), and in five knee joints, the FT was fixed via suture anchors (control group, CG). All reconstructions were evaluated until load to failure of the patella-side fixation with a displacement rate of 200 mm/min.

RESULTS

The mean maximum load to failure in the SG was 395.3 ± 57.9 N. All reconstructions failed by complete tearing off the medial patellar retinaculum from its medial patellar margin, but fixation of the FT remained stable. In the CG, the mean maximum load to failure was 239.4 ± 54.5 N and was significantly different compared to the SG (p = 0.04). All reconstructions failed via pullout of the suture anchors. Stiffness and elongation did not differ between the groups, and no failure of the FT was observed in any of the specimens.

CONCLUSION

Primary stability of soft-tissue MPFL-R using FT was superior to suture-anchor fixation. Both fixation techniques provided sufficient primary stability, superior to previously reported native MPFL tensile strengths. MPFL-R with FT could be a possible alternative procedure for MPFL-R, eliminating potential complications due to autologous tendon graft harvesting.

MPFL repair after acute first-time patellar dislocation results in lower redislocation rates and less knee pain compared to rehabilitation: a systematic review and meta-analysis

PURPOSE

This study aimed to explore the efficacy of medial patellofemoral ligament (MPFL) repair versus nonoperative rehabilitation treatment on the rate of patellar redislocation and functional outcomes in skeletally mature patients with traumatic, first-time patellar dislocations.

MATERIALS AND METHODS

MEDLINE, PubMed and EMBASE were searched from database inception to May 2022 for studies examining the management options for acute first-time patellar dislocations. This study was conducted in accordance with PRISMA and R-AMSTAR guidelines. Data on redislocation rates, functional outcomes including the Kujala score for anterior knee pain, and complication rates were extracted. A meta-analysis was used to pool the mean postoperative Kujala score and calculate the proportion of patients sustaining redislocations using a random effects model. Quality assessment of included studies was performed for all included studies using the MINORS and Detsky scores.

RESULTS

This review included a total of 25 studies and 1,361 patients. The pooled mean redislocation rate in 15 studies comprising 798 patients in the rehabilitation group was 30% (95% CI 25-36%, I² = 65%). Moreover, the pooled mean redislocation rate in 10 studies comprising 170 patients undergoing MPFL repair was 7% (95% CI 3-12%, I² = 30%). The pooled mean postoperative Kujala score in 8 studies comprising 396 patients in the rehabilitation group was 82.5 (95% CI 78.3-86.8, I² = 91%), compared to a score of 88 (95% CI 87-90, I² = 76%) in 3 studies comprising 94 patients in the repair group. Range of motion deficits was reported in 3.8% of 893 patients in the rehabilitation group and 2.0% of 205 patients in the repair group.

CONCLUSION

MPFL repair resulted in a lower rate of redislocation, less knee pain, and noninferiority with respect to a range of motion deficits compared to nonoperative treatment for the management of acute first-time patellar dislocations.

LEVEL OF EVIDENCE

IV.

MPFL reconstruction results in lower redislocation rates and higher functional outcomes than rehabilitation: a systematic review and meta-analysis

PURPOSE

To determine the effect of early MPFL reconstruction versus rehabilitation on the rate of recurrent patellar dislocations and functional outcomes in skeletally mature patients with traumatic, first-time patellar dislocation.

METHODS

Three online databases MEDLINE, PubMed and EMBASE were searched from database inception (1946, 1966, and 1974, respectively) to August 20th, 2021 for literature addressing the management of patients sustaining acute first-time patellar dislocations. Data on redislocation rates, functional outcomes using the Kujala score, and complication rates were recorded. A meta-analysis was used to pool the mean postoperative Kujala score, as well as calculate the proportion of patients sustaining redislocation episodes using a random effects model. Quality assessment of included studies was performed for all included studies using the MINORS and Detsky scores.

RESULTS

A total of 19 studies and 1,165 patients were included in this review. The pooled mean redislocation rate in 14 studies comprising 734 patients in the rehabilitation group was 30% (95% CI 25-36%, I² = 67%). Moreover, the pooled mean redislocation rate in 5 studies comprising 318 patients undergoing early MPFL reconstruction was 7% (95% CI 2-17%, I² = 70%). The pooled mean postoperative Kujala anterior knee pain score in 7 studies comprising 332 patients in the rehabilitation group was 81 (95% CI 78-85, I² = 78%), compared to a score of 87 (95% CI 85-89, I² = 0%, Fig. 4) in 3 studies comprising 54 patients in the reconstruction group.

CONCLUSION

Management of acute first-time patellar dislocations with MPFL reconstruction resulted in a lower rate of redislocation of 7% in the reconstruction group vs 30% in the rehabilitation group and a higher Kujala score compared to the rehabilitation group. The information this review provides will help surgeons guide their decision to choose early MPFL reconstruction versus rehabilitation when treating patients with first-time patellar dislocations and may guide future studies on the topic.

LEVEL OF EVIDENCE

IV.

Protocols of rehabilitation and return to sport, and clinical outcomes after medial patellofemoral ligament reconstruction with and without tibial tuberosity osteotomy: a systematic review

PURPOSE

No consensus exists on rehabilitation programmes after medial patellofemoral ligament reconstruction (MPFLR) with or without tibial tuberosity osteotomy (TTO). This systematic review examined the content and timeline of rehabilitation (weightbearing, range of motion [ROM] and exercise therapy) and return to sport (RTS), as well as patient-reported outcomes after MPFLR with or without TTO.

METHODS

The PubMed, Cochrane Library, Web of Sciences, CINAHL and SPORTDiscus databases were searched from inception to December 2021. Studies that reported postoperative rehabilitation programmes and patient-reported outcomes for patients aged ≥ 18 years who underwent MPFLR with or without concomitant TTO were included.

RESULTS

Eighty-five studies were included, 57 of which were case series and only one randomised controlled trial on rehabilitation programmes. Non-weightbearing was set within one week post-operatively in approximately 80% of weightbearing programmes for MPFLR without and with TTO. Joint immobilisation was set within one week post-operatively in 65.3% and 93.8% of programmes for MPFLR without and with TTO, respectively. Weightbearing and ROM (≤ 90°) restriction were within three weeks post-operatively for > 50% of the programmes. Quadriceps strengthening was the most cited exercise therapy (33 programmes), most often initiated within two weeks post-operatively. However, few other exercise programmes were cited (only nine programmes). RTS was mostly noted at six months post-operatively (35 programmes). The weighted mean Kujala score was 87.4 points.

CONCLUSION

Regardless of TTO addition to MPFLR, most studies restricted weightbearing and ROM only in the early post-operative period, with seemingly favourable clinical results. Limited information was available on post-operative exercise therapy.

A National Perspective of Patellar Instability in Children and Adolescents in the United States: MPFL Reconstruction Is Three Times Higher Than the Incidence of Isolated Lateral Release

PURPOSE

The objective was to (1) evaluate any recent changes in the United States in the incidences of medial patellofemoral ligament (MPFL) reconstruction and isolated lateral release for patellar instability in children and adolescents, (2) identify concomitant procedures with MPFL, and (3) report national complication rates after MPFL reconstruction with and without concomitant procedures in children and adolescents.

METHODS

A national database was queried for patients aged 5 to 18 years who underwent operative treatment for patellar instability from 2010 to 2018. Inclusion criteria were either an MPFL reconstruction or lateral release for a diagnosis of patellar instability. Concomitant procedures with MPFL reconstruction assessed were tibial tubercle osteotomy, associated arthroscopic procedures, and lateral release. Changes in incidence in MPFL reconstruction, lateral release and concomitant procedures were assessed. The following postoperative complications were assessed: knee stiffness, infection, patella fracture, and growth arrest or angular deformity.

RESULTS

2,161 patients who underwent MPFL reconstruction and 1,159 patients who underwent isolated lateral release for patellar instability were identified. The incidence of MPFL reconstruction in adolescents from 2010 to 2018 did not change significantly (2010: 7.11, 2018: 5.91, P = .137), while isolated lateral release decreased (2010: 6.06, 2018: 1.83, P < .0001). Concomitant procedures with MPFL reconstruction were common, with arthroscopy being the most frequent (58-67%). The most common complication within 90 days of surgery was patella fracture (0.4% to 2.0%). Infection (0.4% to 1.0%) and growth arrest (0.09% to 0.61%) were the least common. MPFL and arthroscopy had a decreased risk of growth arrest following surgery compared to MPFL alone (P = .038).

CONCLUSIONS

The incidence of MPFL reconstruction remained high from 2010 to 2018, while isolated lateral release decreased during the same time period. Complications after MPFL reconstruction, isolated lateral release, and concomitant procedures were infrequent, with postoperative patella fracture the most common.

LEVEL OF EVIDENCE

IV, case series.

Changes in patellar morphology following surgical correction of recurrent patellar dislocation in children

Background

The aim of this study was to evaluate patellar morphological changes following surgical correction of recurrent patellar dislocation in children.

Methods

A total of 35 immature children aged 5 to 10 years who suffered from bilateral recurrent patellar dislocation associated with abnormal patella morphology were enrolled in this study. The knees with the most frequent dislocations (treated with medial patellar retinacular plasty) were selected as the study group (SG), and those undergoing conservative treatment for the contralateral knee were selected as the control group (CG). Computed tomography (CT) scans were performed on all children preoperatively and at the last follow-up to evaluate morphological characteristics of the patella.

Results

All the radiological parameters of the patella showed no significant difference between the two groups preoperatively. At the last follow-up for CT scans, no significant differences were found for the relative patellar width (SG, 54.61%; CG, 52.87%; P = 0.086) and the relative patellar thickness (SG, 26.07%; CG, 25.02%; P = 0.243). The radiological parameters including Wiberg angle (SG, 136.25°; CG, 122.65°; P < 0.001), modified Wiberg index (SG, 1.23; CG, 2.65; P < 0.001), and lateral patellar facet angle (SG, 23.35°; CG, 15.26°; P < 0.001) showed statistical differences between the two groups.

Conclusions

The patellar morphology can be improved by early surgical correction in children with recurrent patellar dislocation. Therefore, early intervention is of great importance for children diagnosed with recurrent patellar dislocation.