Good Outcomes of Combined Femoral Derotation Osteotomy and Medial Retinaculum Plasty in Patients with Recurrent Patellar Dislocation

Abstract

Objectives To report the clinical outcomes of combined femoral derotation osteotomy and medial retinaculum plasty for recurrent patellar dislocation in patients with excessive femoral anteversion. Methods From January 2015 to March 2018, 20 knees in 20 patients (18 female, 2 male) with a mean age of 21 ± 4.2 years (range, 16 to 28 years) were retrospectively reviewed. All patients had undergone femoral derotation osteotomy and medial retinaculum plasty for recurrent patellar dislocation and excessive femoral anteversion angle (FAA > 25°). CT and X‐rays were used to assess the correction of the femoral anteversion angle, the tibia tuberosity‐trochlear groove (TT‐TG) distance, patellar tilt, and the congruence angle following the combinatory operations. Subjective scores, such as Kujala, International Knee Documentation Committee (IKDC), Tegner, and visual analogue scale (VAS) scores, were used to evaluate knee function preoperatively and postoperatively. Results No recurrence of patellar dislocation occurred in these patients during an average of 18 months (range, 12 to 23 months) of follow‐up. The mean of the FAA was corrected to 15.80° ± 3.58° postoperatively compared with 31.42° ± 4.95° preoperatively ( P < 0.001). The TT‐TG distance was decreased from 22.17 ± 5.28 mm before surgery to 19.42 ± 4.57 mm after surgery ( P = 0.03). The patellar tilt and congruence angle were improved from 30.43° ± 5.30°, 43.30° ± 11.04° to 15.80° ± 3.94°, 16.64° ± 9.98°, respectively ( P < 0.001). The Kujala score was improved from 72.4 ± 19.90 before the surgery to 88.2 ± 12.25 after the surgery ( P < 0.001). The IKDC score was improved from 70.56 ± 21.44 to 90.78 ± 14.32, and the VAS score was decreased from 4.23 ± 2.11 preoperatively to 1.27 ± 1.08 postoperatively ( P < 0.001). No significant difference in Tegner score (5.46 ± 2.49 vs 5.79 ± 1.44) was found before and after the surgery ( P = 0.2). Patients younger than 20 years old had lower Kujala (83.46 ± 14.56 vs . 90.84 ± 7.74, P = 0.02) and IKDC (83.49 ± 17.35 vs 92.46 ± 9.28, P = 0.04) scores than those older than 20 years. Conclusion Good knee function, pain relief, and improved patellofemoral congruence were achieved with the combined femoral derotation osteotomy and medial retinaculum plasty. The combined operations serve as an ideal treatment for recurrent patellar dislocation and address the primary risk factors.

Clinical Outcomes in Soft Tissue Repair Surgery With and Without Femoral Derotation Osteotomy for Patellar Dislocation: A Retrospective Study

“…the postoperative Tegner score of the patients showed no signi cant improvement in both groups, which was consistent with previous studies [11,18]. We considered that this might be due to the patient's previous patella dislocation, which led to the patient's fear of high-intensity activities and their unwillingness to engage in too many intense activities.…”

“…Also, the MRP avoids potential interference between the femoral tunnel during the reconstruction of the MPFL and the femoral plate screw. Previous studies have also con rmed that DFO + MRP is effective in patients with increased FAA [18]. Therefore, our surgical team increased the number of operations DFO + MRP surgeries in the treatment process, which not only reduced the di culty of surgery but also reduced the surgical costs of patients.…”

“…Fluoroscopy was performed to ensure the reduction of the femoral shaft. A lateral femoral plate was then placed to ensure the xation of the femoral shaft ( Figure.3) [11,18].…”

Correlations between intra and extraarticular factors measured by computed tomography in patients with recurrent patellar dislocation

“…Although the etiology, diagnosis and management of recurrent patellar dislocation have been studied over the past fifteen years, there are still uncertainties regarding the influence of anatomical risk factors on the surgical treatment of the recurrent patellar dislocation. The etiology of patellar instability is multifactorial, including a wide variety of anatomical factors, of which the most important are intra-articular (involving the trochlea and the patella), such as trochlear dysplasia, increased distance between tibial tubercle (TT) and trochlear groove (TG), or a high riding patella (patella alta), or extra-articular (involving the anatomical orientation of the femur or tibia), such as increased femoral anteversion, tibial external rotational deformity, recurved and valgus knee [3,4]. Recurrent patellar dislocation can lead to persistent symptoms and long-term complications such us osteochondral fracture or patellofemoral arthritis, and consequently disturbances of knee anatomy and soft tissue integrity that create a predisposition to patellar instability.…”

Modified Langenskiöld procedure for chronic, recurrent, and congenital patellar dislocation

“…We consider rotational osteotomies for femoral anteversion > 25° to 30° from normal. 39 , 40 External tibial torsion should be assessed by measuring the transmalleolar axis, thigh foot angle and observing gait. If excessive external tibial torsion in addition to increased femoral anteversion is present (‘miserable malalignment’) a derotational tibial osteotomy should be considered in addition to femoral osteotomy.…”