Association Between Preoperative Joint Line Convergence Angle and Clinical Outcomes After Isolated Medial Meniscus...

Area of Science:

• Orthopedic surgery
• Biomechanics
• Radiographic analysis

Background:

• Coronal malalignment impacts outcomes after medial meniscus posterior root tear (MMPRT) repair.
• Hip-knee-ankle angle (HKAA) may not fully represent the medial compartment's biomechanics.
• Joint line convergence angle (JLCA) reflects the intra-articular environment but its prognostic value post-MMPRT repair is understudied.

Purpose of the Study:

• Evaluate the association between preoperative JLCA and patient-reported outcomes (PROs) after MMPRT repair.
• Determine if JLCA offers prognostic information independent of HKAA.
• Hypothesize that higher JLCA correlates with inferior PROs and is a stronger predictor than HKAA.

Main Methods:

• Retrospective review of 62 patients undergoing isolated MMPRT repair.
• Measurement of preoperative and postoperative JLCA on weightbearing knee radiographs.
• Assessment of PROs (IKDC, KOOS-short) preoperatively and at 24 months postoperatively.
• Multivariable linear regression and ROC analysis to assess JLCA's independent association and predictive ability.

Main Results:

• Both IKDC and KOOS-short scores significantly improved postoperatively (P < .001).
• Higher preoperative JLCA was significantly associated with lower 24-month IKDC (r = -0.34; P = .008) and KOOS-short (r = -0.36; P = .004) scores.
• JLCA remained independently associated with outcomes, while HKAA did not, in multivariable models.

Conclusions:

• Preoperative JLCA is an independent predictor of clinical outcomes following isolated MMPRT repair.
• JLCA incorporation can enhance preoperative patient counseling and risk stratification.
• Identifying patients who may benefit from strategies to optimize medial compartment biomechanics.