Paper 33: Absorbable single-stay suture bridge fixation for osteochondral fractures following patellar dislocation

Objectives: Osteochondral and chondral fractures of the knee, commonly associated with patellar dislocation, are typically seen in the patella or femoral condyles and can be extremely painful and debilitating if left untreated. Consequently, early treatment of these lesions is paramount, and most surgeons advocate for fixation of displaced fragments utilizing biodegradable or metallic screws, rods, and pins. An alternative to these methods is the use of an absorbable suture bridge construct that allows for minimal disruption to subchondral bone, sparing of articular cartilage, lack of retained hardware that may require removal, and the ability to distribute pressure evenly to the cartilage surface. The present study aimed to evaluate the short-term clinical and radiographic outcomes following suture bridge fixation of an osteochondral fracture after a patellar dislocation.
Methods: A single-center review identified osteochondral or chondral fractures following a patellar dislocation from 2019 to 2024 that were treated with suture bridge fixation of the lesion. Cases with evidence of chronic osteochondral pathology, including osteochondritis dissecans, were excluded. Osteochondral fractures not associated with a confirmed patellar dislocation or fixated with a non-absorbable suture were also excluded. Demographic information along with operative details, radiographic results, additional surgical procedures, return to play, and patient-reported outcome measurements (PROMs) were collected and reviewed retrospectively. Mechanism of injury and sports participation were gathered from a prospectively collected questionnaire. Descriptive statistics were reported as mean and standard deviation or quantity and percentage for all variables. Wilcoxon signed-rank tests were used to statistically compare pre-operation and post-operation PROMs. Statistical significance was set at p < 0.05.
Results: Sixty-five patients (mean age 14.0 +- 2.0 years, range 10-21, 49.2% female) sustained sixty-seven osteochondral or chondral fractures in the patella (38 lesions, 56.7%), lateral femoral condyle (27 lesions, 40.3%), or trochlea (2 lesions, 3.0%). Mean lesion size was 250.6 +- 130.9 square millimeters (mm2) with a mean major length (either length or width) of 18.1 +- 4.7 mm. 57 (85.1%) fractures included subchondral bone. All patients underwent single-stage arthroscopic evaluation, medial patellofemoral ligament reconstruction, and open reduction and internal fixation utilizing a suture bridge construct with a mean of 3.7 +- 0.9 anchors and #1 Vicryl (Ethicon), except for two patients in which the suture bridge was performed arthroscopically, at a mean of 24.2 +- 24 days after injury. Figure 1 details pre-operative, intraoperative, and post-operative imaging of suture bridge fixation for an osteochondral fracture. Sports-related injuries (59.7%) accounted for the majority of fractures with contact sports attributed to 72.5%. Mean return to sports was 5.8 +- 5.5 months. At a mean of 16.0 +- 11.8 months follow-up, only 3 (4.5%) lesions required repeat surgery related to the procedure in which they underwent marginal chondroplasty. Post-operative MRI data was available for 36 (54.7%) lesions. 29 (80.6%) demonstrated full union, 7 (19.7%) stable union, and 0 nonunion. Prior to surgery, mean patient-reported outcome measurements (PROMs) were BPII 37.7 +- 17.6, KOOS 47.7 +- 21.2, Pedi-IKDC 28.5 +- 17.7, and Kujala 36.0 +- 13.9. PROMs at a mean 17.6 +- 14.1 months post-operation were significantly higher including BPII 78.7 +- 19.9 (p < 0.001), KOOS 96.9 +- 6.5 (p < 0.001), Pedi-IKDC 87.7 +- 12.4 (p < 0.001), and Kujala 91.4 +- 10.0 (p < 0.001).
Conclusions: Suture bridge fixation of osteochondral fractures following a patellar dislocation is a viable option with excellent radiographic healing, low return-to-surgery rates, and excellent clinical outcomes. Future studies with longer follow-up and direct comparison between traditional fixation methods and suture bridge fixation are warranted.