Background: The medial patellofemoral ligament (MPFL) is the primary passive restraint to lateral patellar dislocation and there is increasing awareness of its role in recurrent lateral patellar instability.
Purpose: This study was conducted to prospectively analyze the functional results of a modified MPFL reconstruction technique in recurrent patellar dislocation.
Study Design: Case series; Level of evidence, 4.
Methods: Forty-eight patients (51 knees) with at least 3 episodes of lateral patellar dislocation who had been treated with a 6-month rehabilitation protocol were included in this study. All patients practiced sports regularly. Reconstruction was with a semitendinosus tendon using a divergent 2-tunnel technique. Outcome was evaluated with the Kujala, Larsen, modified Lysholm, and Fulkerson outcome scores. Patient satisfaction with range of motion, pain, and sporting activities was also assessed.
Results: Three patients were lost at the final follow-up, giving a follow-up rate of 94%. The mean follow-up was 33 months. There was no patella dislocation postoperatively. The mean Kujala score improved significantly (P < .01) from 56.7 ± 17.7 (2 x standard deviation) preoperatively to 86.8 ± 14.4 postoperatively. The mean Larsen score improved significantly (P < .01) from 12.4 ± 3.2 to 17.1 ± 2.7. The mean Fulkerson score improved significantly (P < .01) from 59.2 ± 21.8 to 90.1 ± 14. The mean modified Lysholm score improved significantly (P < .01) from 57.6 ± 19.6 to 88.1 ± 16.2. Sixty-four percent of patients returned to the same type of sport at the same level, 16% reduced the level or type of sport for reasons unrelated to the surgery, while 20% reduced the level of sport or changed it for reasons related to surgery. Eighty-seven percent were either satisfied or very satisfied with the pain relief achieved. The patellar tilt decreased significantly from a preoperative mean of 11.1° to 8.9° at the last follow-up (P = .02). The mean preoperative Insall-Salvati ratio of 1.1 decreased to 1.06, although the change was not significant (P = .1).
Conclusion: The results of modified MPFL reconstructions are encouraging, with minimal risks of redislocation and an overall patient satisfaction rate of over 80%. These early and medium-term results are comparable with those of other MPFL reconstruction techniques reported in the literature.
Background: The medial patellofemoral ligament (MPFL) is the most important factor for stabilizing the patella and preventing lateral patellar dislocation. Medial patellofemoral ligament reconstruction is an accepted surgical technique to restore patellofemoral stability after lateral patellar dislocation. The authors recently developed a new anatomical MPFL reconstruction method using a cylindrical bone plug and grafted semitendinosus tendon at the anatomical femoral attachment site to mimic the native MPFL. This study evaluated the new technique for stabilizing recurrent patellar dislocation.
Hypothesis: This new MPFL reconstruction technique will improve knee symptoms and function with excellent clinical results.
Study Design: Case series; Level of evidence, 4.
Method: Thirty-one knees were evaluated from 29 cases of recurrent patellar dislocation that were surgically treated using the anatomical MPFL reconstruction technique. The average patient age was 22.2 years (range, 12-34 years); postsurgery follow-up was 2 to 5 years (average, 3.2 years). The patients were clinically evaluated based on the Kujala score, range of motion, and signs of apprehension. The Merchant view was used to measure congruence and tilting angles.
Results: Of the 31 knees, 30 showed good clinical results after surgery, while 1 patient showed remaining signs of apprehension. The Kujala score improved from an average of 64 points (range, 35-70) initially to an average of 94.5 points (range, 79-100) at the final follow-up. Range of motion improved for all patients, with an average knee extension of 0° ± 2° and knee flexion of 145° ± 3° at final follow-up. No patellar redislocation was reported. Radiological assessment indicated significant improvement to the congruence angle from 13° ± 4° before surgery to –5° ± 5° at the final follow-up, while the tilting angle went from 8° ± 7° before surgery to 7° ± 4° at the final follow-up.
Conclusion: This study demonstrated excellent results using the new procedure for recurrent dislocation of the patella, with instability in only 1 of 31 knees (3.2%).
Background:
Although patients considered “successful” at longer-term follow-up no longer exhibited patellar instability, those with more severe malalignment issues had other, gradually worsening symptoms such as activity-related pain, crepitation, swelling with activities, and pain with weather changes.
Hypothesis:
Improvement of patellar tracking by correction of the tubercle-sulcus angle and related ligament deficiencies will result in good to excellent results, regardless of the technique employed.
Study Design:
Cohort study; Level of evidence, 3.
Methods:
Twenty-five patients with dislocating patellae and significant lower leg deformity were treated; 12 patients (group 1) underwent a derotational high tibial osteotomy and 13 patients (group 2) underwent an Elmslie-Trillat-Fulkerson proximal-distal realignment. All were prospectively evaluated a minimum of 24 months postoperatively with a physical examination, validated outcome questionnaires, radiographs, and computerized axial tomography scans. Postoperative 3-dimensional bilateral gait analyses were performed on all subjects walking on a 3-dimensional force treadmill to measure stance kinematics, foot progression angle, knee flexion, knee valgus-varus, hip flexion, and patella angle. Contralateral limbs with similar preoperative alignment were used as controls.
Results:
Group 1 patients significantly improved over their preoperative status in all primary subjective and functional outcome parameters, and were significantly better than group 2 patients. Group 2 patients improved, but not to the degree of group 1 patients. Gait analysis revealed group 1 patients had more symmetrical gait patterns, with less variability and less compensatory gait changes, than group 2 patients.
Conclusion:
The original hypothesis proved to be incorrect. The simultaneous correction of ligament imbalance, excessive tubercle-sulcus angle, and lower limb torsional deformity produced significantly better results than conventional proximal-distal realignment.
