Medial Patellofemoral Ligament Reconstruction in a Revision Setting: Anchor and Interference Screw Fixation

Combined Autologous Adductor Magnus and Partial Quadriceps Tendon Technique for Medial Patellofemoral Ligament Reconstruction and Cellularized Scaffold Implantation of the Patella

There are many studies in the literature on the use of adductor magnus and quadriceps tendons in primary or revision surgery of patellofemoral instability in skeletally immature patients. In this Technical Note, the combination of both tendons is presented with cellularized scaffold implantation cartilage surgery in the patella.

Femoral tunnel malposition is the most common indication for revision medial patellofemoral ligament reconstruction with promising early outcomes following revision reconstruction: a systematic review

PURPOSE

The purpose of this study was to identify the causes of failure of previous medial patellofemoral ligament reconstruction (MPFL-R), and to furthermore report the surgical techniques available for MPFL revision surgery.

METHODS

Four databases [PubMed, Ovid (MEDLINE), Cochrane Database, and EMBASE] were searched until September 29, 2020 for human studies pertaining to revision MPFL. Two reviewers screened the literature independently and in duplicate. Methodological quality of the included studies was assessed using the Methodological Index for Non-Randomized Studies (MINORS) criteria, or the CAse REport guidelines (CARE), where appropriate.

RESULTS

Fourteen studies (one level II, one level III, two level IV, ten level V) were identified. This search resulted in a total of 76 patients with a mean age (range) of 22 (14-39) years. The patients were 75% female with a mean (range) time to revision of 24.1 (1-60) months and mean (range) follow-up of 36.2 (2-48) months. The most common indication for revision surgery was malpositioning of the femoral tunnel (38.1%), unaddressed trochlear dysplasia (18.4%), patellar fracture (11.8%). Femoral tunnel malposition was typically treated via revision MPFL-R with quadriceps tendon or semitendinosus autograft and may retain the primary graft if fixation points were altered. Unaddressed trochlear dysplasia was treated with deepening trochleoplasty with or without revision MPFL-R, and patella fracture according to the nature of the fracture pattern and bone quality. Though generally, outcomes in the revision scenario across all indications were inferior to those post-primary procedure, overall, revision patients demonstrated positive improvements in pain and instability symptoms. Transverse patella fractures treated with debridement and filling with demineralized bone matrix if required with further fixation according to the fracture pattern.

CONCLUSION

The most common causes of MPFL failure in literature published to date, in order of decreasing frequency, are: malposition of the femoral tunnel, unaddressed trochlear dysplasia, and patellar fracture. Although surgical techniques of revision MPFL-R to manage these failures were varied, promising outcomes have been reported to date. Larger prospective comparative studies would be useful to clarify optimal surgical management of MPFL-R failure at long-term follow-up.

LEVEL OF EVIDENCE

IV.

Safety and Performance of Titanium Suture Anchors Used in Knee Ligament Repair Procedures

Injuries to the knee ligaments can be particularly disabling in young patients, given the risk of long-term disability if adequate fixation is not achieved during initial repair. The TWINFIX™ titanium (Ti) suture anchor with ULTRABRAID™ Suture (Smith and Nephew, London, UK) was designed to secure tendon and ligament reconstructions with increased boney ingrowth at the anchor site with minimal invasive technique. This retrospective analysis looked at 33 patients (41 implants) operated with this device between 2015 and 2019 at a single institution. The average age of patients was 33.18 years (standard deviation [SD], 15.26), with an average body mass index of 24.88 (SD, 3.49). The indications were lateral extra-articular tenodesis during anterior cruciate ligament reconstruction, medial patellofemoral ligament reconstruction, quadriceps or patellar tendon repair and medial collateral ligament repair. After an average follow up of 24.3 + 6.53 months, there was no reports of clinical failure or radiographic evidence of implant failure or loosening. One patient experienced a complication unrelated to the study device, requiring manipulation under anesthesia with resolution of symptoms. This case series supports the safety and performance of this implants for the knee procedures in which its use is indicated. Additional follow-up will be required to determine whether these effects are sustained at medium- and long-term durations.