Background:A habitual patellar dislocation (HPD) is a rare condition in skeletally
mature patients, especially for those with severe quadriceps contracture.
Until now, no study has reported the effectiveness of tibial tubercle
proximalization to lengthen the extensor mechanism in treating severe HPDs
in skeletally mature patients.Purpose:To describe a novel comprehensive procedure that includes tibial tubercle
proximalization, extensive lateral release, tibial tubercle medialization,
and medial patellofemoral ligament (MPFL) reconstruction in treating severe
HPDs in skeletally mature patients and to report its early clinical
outcomes.Study Design:Case series; Level of evidence, 4.Methods:From January 2014 to May 2016, a total of 43 consecutive patients (47 knees)
with HPDs were surgically treated at a single institution and were
retrospectively reviewed. Among them, 11 skeletally mature patients (11
knees) with severe primary HPDs underwent the index comprehensive procedure.
Results of patellar tracking were recorded preoperatively and at the final
follow-up. The radiological assessment included radiographs in standard
anteroposterior, true lateral, and axial views and computed tomography scans
at full knee extension before surgery and at the final follow-up. Subjective
patellofemoral function was evaluated with the Kujala functional score
before the index procedure and at the final follow-up visit.Results:The 11 included patients were evaluated for a mean period of 34.9 months
(range, 25-46 months). The mean knee flexion angle when the patella
dislocated laterally was 25° (range, 10°-30°) preoperatively.
Radiologically, there was a statistically significant improvement in the
congruence angle, from 73.4° ± 17.0° preoperatively to –7.1° ± 5.8°
postoperatively (P < .01) and in the lateral
patellofemoral angle, from –65.6° ± 9.4° preoperatively to 6.1° ± 2.7°
postoperatively (P < .01). The mean preoperative Kujala
functional score was 42.9, and the mean postoperative Kujala functional
score was 95.2 (P < .05). No patients reported a
recurrence of patellar dislocation at the final follow-up visit.Conclusion:The novel comprehensive procedure, including tibial tubercle proximalization,
extensive lateral release, tibial tubercle medialization, and MPFL
reconstruction, effectively treated lateral HPDs in skeletally mature
patients with severe quadriceps contracture.