Interference screws vs.suture anchors for isolated medial patellofemoral ligament femoral fixation:A systematic review

Purpose:The present study aimed to systematically review and compare 2 femoral autograft fixation techniques,namely,interference screws and suture anchors,for isolated medial patellofemoral ligament reconstruction in patients with recurrent patellofemoral instability at mid-to long-term follow-up.Methods:A literature search was performed in September 2020.All studies reporting the outcomes of primary isolated medial patellofemoral ligament reconstruction for recurrent patellofemoral instability were considered for inclusion.Only studies reporting the type of femoral autograft fixation under examination were considered.Studies reporting data from patients with elevated tibial tuberosity-tibial groove,patella alta,and/or Dejour’s trochlear dysplasia types C and D,were not included.Only articles reporting data with a minimum follow-up period of 18 months were considered.Results:Data from 19 studies(615 patients)were retrieved.The overall age was 24.4±6.7 years(mean±SD).The mean follow-up was 46.5±20.9 months.There were 76 patients in the anchor group and 539 in the screw group.Comparability was found with regard to age and follow-up duration between the 2 study groups.There was comparability between the Kujala,Lysholm,and Tegner scores at baseline.At the last follow-up,no worthy differences were found in terms of mean Kujala(+2.1%;p=0.04),Lysholm(+1.7%;p=0.05),and Tegner(+15.8%;p=0.05)scores.Although complications occurred almost exclusively in the screw cohort,no statistically significant difference was found.Conclusion:Femoral autograft fixation through interference screws or suture anchors report similar clinical scores and rate of apprehension test,persistent joint instability,re-dislocations,and revisions.These results must be interpreted within the limitations of the present study.

Reconstruction of the Medial Patellofemoral Ligament Using Hamstring Tendon Graft With Different Methods:a Biomechanical Study

Objective To measure the tensile strength of the normal medial patellofemoral ligament(MPFL),and evaluate the biomechanics of different fixation methods of the hamstring tendon graft on the patella.Methods Eight fresh cadaver knees were prepared by isolating the patella,leaving only the MPFL as its attachment to the medial condyle of femur.The MPFL was reconstructed by three different methods:four-suture fixation,anchors-single suture fixation,and anchors-double suture fixation.The tensile strength and the elongation of the normal MPFL and the tendon grafts were measured.Results The tensile strength of the four-suture fixation group(234.86±49.02 N)was stronger than that of the normal MPFL(146.91±25.30 N,P=0.0014)and the anchors-single suture group(159.17±49.07N,P=0.0077),while weaker than that of the anchors-double suture group(314.74±78.46 N,P=0.0052)Conclusions With regard to the tensile strength,the four-suture fixation method is reliable for clinical use.Compared with the anchor-suture method,the four-suture fixation method which has no specific implants is more economical,convenient and efficient.

Combined medial patellofemoral ligament and medial patellotibial ligament reconstruction in recurrent patellar instability:A systematic review and meta-analysis

BACKGROUND The medial patellofemoral ligament(MPFL),along with the medial patellotibial ligament(MPTL)and medial patellomeniscal ligament,aid in the stabilization of the patellofemoral joint.Although the MPFL is the primary stabilizer and the MPTL is a secondary limiter,this ligament is critical in maintaining joint stability.There have been few studies on the combined MPFL and MPTL reconstruction and its benefits.AIM To look into the outcomes of combined MPFL and MPTL reconstruction in frequent patellar instability.METHODS By May 8,2022,four electronic databases were searched:Medline(PubMed),Scopus,Web of Science,and Google Scholar.General keywords such as"patellar instability,""patellar dislocation,""MPFL,""medial patellofemoral ligament,""MPTL,"and"medial patellotibial ligament"were co-searched to increase the sensitivity of the search.RESULTS The pooled effects of combined MPFL and MPTL reconstruction for Kujala score(12-mo followup)and Kujala score(24-mo follow-up)were positive and incremental,according to the findings of this meta-analysis.The mean difference between the Cincinnati scores was also positive,but not statistically significant.The combination of the two surgeries reduces pain.According to cumulative meta-analysis,the trend of pain reduction in various studies is declining over time.CONCLUSION The combined MPFL and MPTL reconstruction has good clinical results in knee function and,in addition to providing good control to maintain patellofemoral joint balance,the patient's pain level decreases over time,making it a valid surgical method for patella stabilization.

Research progress of medial patellofemoral ligament reconstruction

Patellar dislocation is a common disease in orthopaedics. The incidence of patellar dislocation is the highest in adolescents with an average age of 21.4 years. There are many methods to treat the dislocation of patella, among which the reconstruction of medial patellofemoral ligament (MPFL) is the main one. In this paper, the biomechanics and graft selection of medial patellofemoral ligament reconstruction were discussed in detail by reviewing the relevant literature at home and abroad. The femoral insertion, patellofemoral fixation and postoperative complications were also discussed, in order to provide reference for clinical workers. In view of different postoperative complications, there are many kinds of optimization schemes, and reasonable choice of operation scheme is the premise of good operation satisfaction rate.

Combination of medial patellofemoral ligament reconstruction with vastus medialis advancement for chronic patellar dislocation

Background The medial patellofemoral ligament （MPFL） reconstruction is popular in clinical practice for chronic patellar dislocation; however, the combination with vastus medialis advancement is rare. The aim of this study was to evaluate the clinical outcome of the combination of MPFL reconstruction with vastus medialis advancement.Methods We retrospectively analyzed 69 patients with chronic patellar dislocation between July 2004 and October 2008： twenty eight cases with isolated MPFL reconstruction （group Ⅰ）, forty one cases with the combination of MPFL reconstruction with vastus medialis advancement （group C）. All patients had CT scans available for review with knee flexion at 30 degree, on which the congruence angle, patellar tilt angle and patellar lateral shift were measured. Physical apprehension tests were examined and the redislocation was recorded. In addition, knee function was evaluated using the Kujala score and subjective questionnaires.Results Patients were followed up for a mean of 42 months （12-65 months） without a recurrent dislocation reported.Postoperatively, all indexes on CT scan were within the normal range without a statistical difference between the two groups. Results from the apprehension test showed eight patients in group Ⅰ and three in group Chad patellar lateral shift exceeding 1.5 cm with a hard end point （P 〈0.05）. The Kujala score improved significantly from 51.3±4.5 to 79.9±6.2 in group Ⅰ and from 53.7±5.2 to 83.9±6.5 in group C （P 〉0.05）. However, the subjective questionnaire revealed a significant difference （P 〈0.05）, including 12 excellent, seven good and nine fair in group Ⅰ and 30 excellent, six good and five fair in group C.Conclusion The combination of MPFL reconstruction with vastus medialis advancement is better than isolated reconstruction to improve the subjective effects and decrease the patellar instability rate for chronic patellar dislocation.

Reconstruction of the medial patellofemoral ligament with a suture-tie technique of patellar side fixation

Background Medial patellofemoral ligament （MPFL） reconstruction is the preferred operative treatment for recurrent patellar dislocation. The purpose of this study was to report a novel suture-tie technique of patellar side fixation in medial patellofemoral ligament reconstruction for recurrent patellar dislocation, and to evaluate the intermediate-term results. Methods We retrospectively reviewed the results of 22 MPFL reconstructions in 21 patients （6 male and 15 female） with a suture-tie technique performed by a single surgeon between March 2004 and July 2009. All patients had been diagnosed with recurrent patellar dislocation. Outcomes were assessed preoperatively and postoperatively by physical and radiographic examination as well as with Kujala and Lysholm scores. Results At the mean follow-up month 37.5 （range： 24-56 months）, there was no graft failure. Primary healing was achieved in all cases. At the final follow-up, the mean Kujala score improved from 53.9 （range： 46-62 points） to 84.1 （range： 78-90 points） postoperatively （P 〈0.05）, and the mean Lysholm score improved from 47.2 points （range： 37-57 points） to 82.8 points （range： 76-89 points） postoperatively （P 〈0.05）. To date, no patients have reported redislocation or subluxation; however, there is one patient with a positive apprehension test. Conclusion A suture-tie technique in medial patellofemoral ligament reconstruction can restore patella stability without significant complication.