Arthroscopy - 2026-04-07 - Journal Article; Review
Wide Variability in the Radiographic Location of the Medial Patellofemoral Ligament Femoral Attachment: A Systematic Review and Meta-analysis.
Williams MK, Esser KL, Chen L, Lezak BA, Gould HP, Golant A, Kaplan DJ
Topics
Key Takeaway
The MPFL femoral attachment varies up to 13.6 mm in the AP direction across cadaveric studies, with a pooled range spanning 4.80 mm posterior to 8.80 mm anterior to the posterior cortical extension line, exceeding the 3 mm surgical tunnel radius threshold in multiple studies.
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Summary
This systematic review and meta-analysis evaluated cadaveric studies using radiopaque markers to quantify MPFL femoral attachment location relative to Schöttle's point on lateral radiographs. Pooled AP position averaged 1.04 mm anterior to the posterior cortical extension line (range: 4.80 mm posterior to 8.80 mm anterior), and proximal-distal position averaged 2.07 mm proximal to Blumensaat's line (range: 0.90 mm distal to 4.70 mm proximal). Inter-study heterogeneity exceeded the 3 mm surgical tunnel radius threshold, indicating that Schöttle's point alone is insufficient to guarantee anatomic tunnel placement.
Key Limitation
The cadaveric cohort (mean age 62.45 years) may not reflect the bony anatomy of the adolescent and young adult population in whom MPFL reconstruction is most commonly performed.
Original Abstract
PURPOSE
To systematically review and meta-analyze cadaveric studies quantifying the medial patellofemoral ligament (MPFL) femoral attachment site using radiopaque markers on radiographs to evaluate the accuracy of Schöttle's point as a radiographic landmark for MPFL attachment.
METHODS
A systematic review and meta-analysis was performed of the PubMed, EMBASE, and Scopus databases to identify cadaveric studies reporting the radiographic position of the MPFL femoral attachment. Included studies reported attachment location relative to the posterior cortical extension line in the anterior-posterior direction and to either the posterior point of Blumensaat's line or another radiographic landmark in the proximal-distal direction. The distance between Schöttle's point and other mean radiographic locations were calculated; distances greater than 3 mm, the radius of a femoral surgical tunnel, represented substantial variation.
RESULTS
Nine studies of 94 cadaveric knees were included in the final analysis with a mean age of 62.45 ± 11.64 years. The average distance from the posterior cortical extension line to the MPFL insertion was 1.04 ± 10.09 mm anterior [95% CI: 0.40, 2.28, range: 4.80 mm posterior to 8.80 mm anterior] (n = 94). The average distance from Blumensaat's line was 2.07 ± 5.06 mm proximal [95% CI: 1.12, 2.00, range: 0.90 mm distal to 4.70 mm proximal] (n = 77). Three studies reported mean distance from the condylar transition line, averaging 2.88 ± 6.02 mm distal [95% CI: -5.04, -0.54, range: 0.50-5.70 mm distal] (n = 25).
CONCLUSIONS
There was substantial heterogeneity in the radiographic location of the MPFL attachment, which suggests that relying solely on Schöttle's point risks nonanatomic tunnel placement.
CLINICAL RELEVANCE
Although Schöttle's point is commonly used as a radiographic landmark during MPFL reconstruction, its variability suggests that the utilization of additional methods of assessment such as clinical palpation and graft isometry evaluation may enhance surgical precision and outcomes.