Evaluation of infrapatellar tendon plication in spastic cerebral palsy with crouch gait pattern: a pilot study

Abstract

Objective: In order to substantially improve crouch pattern in cerebral palsy, the existent patella alta needs to be addressed. This pilot study evaluates the effectiveness of a previously described infrapatellar tendon plication for the treatment of patella alta in crouch gait pattern in skeletally immature spastic cerebral palsy patients.

Methods: In 10 skeletally immature patients (20 knees) with spastic diplegia and crouch gait, the previously described technique by Joseph et al. for infrapatellar tendon plication was evaluated within the setting of single event multilevel surgery (SEMLS). Outcome measures included knee extension lag, Koshino's radiological index for patella alta, and the occurrence of complications. Patients were followed-up for a minimum of 12 months.

Results: The extensor lag improved and was statistically significant in all cases of the study with no incidence of tibial apophyseal injury at the latest follow-up. Radiographic Koshino index normalized and was maintained all through the follow-up period except in one patient (5%) who was overcorrected. Two patients (4 knees, 20%) showed postoperative knee stiffness due to casting which resolved with physiotherapy within six weeks. One knee (5%) developed a superficial infection which also resolved uneventfully with repeated dressings.

Conclusion: The described infra-patellar plication technique in skeletally immature spastic diplegics appears effective, safe, and reproducible.

Keywords: Cerebral palsy; Crouch gait; Moment arm; Patella alta; Patellar tendon plication; Pediatric knee.

Figure 1

Measurement of the knee extensor lag depicted by the angle at the intersection of both blue lines with ipsilateral hip extension and flexion of the contralateral hip to minimize the stretch of the hamstrings.

Figure 2

Surgical technique. (A) After midline incision the patellar tendon after dissection of the paratenon is shown. (B) Three equal slips are created by two vertical incisions taking care not to damage the distal insertion into the tibial tuberosity. (C) Stay sutures are applied to the two peripheral slips and by down pulling of the central slip the patella is brought into the desired position. (D) After radiological confirmation of the proper patellar position the stay sutures are tightened over the patella. (E) The central slip is double breasted, the three slips are joined together and augmentation by nonabsorbable suture material is done at the patella.

Figure 3

(A) Preoperative clinical presentation of a 13-year-old female with spastic diplegia and crouching gait, GMFCS II. (B) and (C) right and left extension lag of 17° and 11°, respectively. (D) Preoperative Koshino index left 1.5 and right 1.36. (E) and (F) Clinical picture 6 months after bilateral patellar tendon plication, bilateral iliopsoas tendinous release, left rectus femoris intramuscular lengthening and bilateral double column osteotomy. G. and H. Extension lag 5° right and 0° left knee. (I) and (J) Koshino index right knee 1 and left knee 0.9.