Voluntary femoro-tibial subluxation is a rare entity predominantly found in pretoddlers. It presents as a dynamic phenomenon with uni- or bilateral audible snapping of the knee, often in a context of fatigue or irritation at the end of the day. The aim of the study was to observe the evolution and recovery in these patients.
Ten children were included. Other causes of dislocating joints and pathologies with snapping of the lateral meniscus were excluded from this study. Six-week immobilisation with a splint at 70° of knee flexion was primarily recommended to all patients.
The mean age at onset of symptoms was 10 months. Forty percent of the patients presented with bilateral symptoms. Clinically, four patients were hyperlax. In all patients, subluxations could be reproduced passively by rotating the foot externally and advancing the internal tibial plateau anteriorly. Three of the patients were treated with a dorsal splint and experienced significantly less or cessation of symptoms. Two patients underwent surgery, one for a concomitant anterior cruciate ligament (ACL) rupture and meniscus tear that worsened the symptoms, another for concomitant patella dislocation and a meniscus tear. One patient’s parents refused treatment and four patients experienced less symptoms at the time of consultation and were not immobilized. Except for the two patients undergoing surgeries, no sequelae were observed. In general, the symptoms got less frequent when the patient began to walk.
Voluntary femoro-tibial subluxation in children is a rare and benign condition that often resolves spontaneously without sequelae. The risk of meniscus tear should, however, be considered if subluxations do not cease.
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Addison OL (1912) Two cases of partial subluxation of knee-joints, with voluntary production of noise during flexion and extension. Proc R Soc Med 5:9–10
Beals RK (1978) The snapping knee of infancy. J Bone Joint Surg 60A:679–680
Choudhary MM, Gupta S (2015) Voluntary inferior shoulder dislocation in a seven year old child—a case report. Int J Surg Cases 1(1):4–6
Huber H, Gerber C (1994) Voluntary subluxation of the shoulder in children. J Bone Joint Surg (Br) 76(1):118–122
Keret D, Reis ND (1986) Voluntary habitual dislocation of the hip joint in a child. J Ped Orthop 6:222–223
Kocher MS, Logan CA, Kramer DE (2017) Discoid lateral meniscus in children: diagnosis, management and outcomes. J Am Acad Orthop Surg 25:736–743
Maric Z, Stein SR (1994) Voluntary habitual dislocation of the hip in children. Orthopedics 17:1147–1148
Mutlu S, Mutlu H, Mutlu B, Guler O, Duymus TM (2014) Symptoms of discoid lateral menisci. J Orthop 11:180–182
Robinson D, Halperin N (1991) Active knee joint subluxation: its influence on the prognosis of ligament reconstruction. Acta Orthop Scand 62(3):264–265
Song KS, Choi IH, Sohn YJ, Shin HD, Leem HS (2003) Habitual dislocation of the hip in children: report of eight additional cases and literature review. J Pediatr Orthop 23(2):178–183
Takai S, Yoshino N, Hirasawa Y (1998) Arthroscopic treatment of voluntary superior dislocation of the patella. Arthroscopy 14:753–756
Thorndike A (1898) Voluntary lateral dislocation of the knees in infants with lax ligaments. Two cases. J Bone Joint Surg 111:199–201
Van Steyn MO, Mariscalco MW, Pedroza AD, Smerek J, Kaeding CC, Flanigan DC (2016) The hypermobile lateral meniscus: a retrospective review of presentation, imaging, treatment, and results. Knee Surg Sports Traumatol Arthrosc 24(1555–155):9
Welby F, Filipe G, Mary P (2003) Luxation volontaire de la hanche chez l’enfant. Rev Chir Orthop 89:62–66
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Kwiatkowski, B., Mouton, C., Raux, S. et al. Voluntary femoro-tibial subluxations: a benign differential diagnosis in the snapping knee of a child. Knee Surg Sports Traumatol Arthrosc (2020) doi:10.1007/s00167-019-05831-6
- Femoro-tibial subluxation
- Knee subluxation
- Voluntary subluxation