A minimally invasive treatment protocol for the congenital dislocation of the knee.

BACKGROUND

Congenital dislocation of the knee is a rare condition for which the treatment is difficult and remains controversial. For severe cases associated with neuromuscular disorders treatment has usually consisted of extensive surgical reconstruction. The purpose of this study is to assess the short-term results of a new method of treatment for this patient population that involves casting and less extensive surgery.

METHODS

We retrospectively reviewed the cases of 8 consecutive patients, 4 girls and 4 boys, with 16 congenitally dislocated knees that had been diagnosed and treated by a single surgeon with a new minimally invasive treatment protocol. Treatment consisted of serial casting followed by a mini-open quadriceps tenotomy. The mean age at presentation was 5.3 weeks (range, 1 to 13 wk). The mean follow-up was 33 months (range, 12 to 72 mo). All knees were graded in terms of function at final follow-up.

RESULTS

Serial casting alone was effective in achieving correction in 3 knees. The remaining 13 knees had an average of 7 casts (range, 5 to 9 casts) before surgery. Ten knees were treated with a mini-open quadriceps tenotomy alone and 3 with an additional anterior capsulotomy at the time of the initial surgery. Two knees developed recurrent deformities and required additional surgery. Two knees sustained plastic deformation of the proximal tibia during physical therapy that resolved with time. At final follow-up, knee outcome was excellent in 11 (69%) knees, good in 3 (19%) knees, and fair in 2 (12%) knees.

CONCLUSIONS

The results of our study support the use of a less invasive approach for the initial treatment of congenital dislocation of the knee in this patient population. This approach avoids the complications of extensive scarring and stiffness that often accompany the more invasive surgical treatments. Longer follow-up, however, is necessary to see whether reduction and knee range of motion are maintained.

LEVEL OF EVIDENCE: Level 4 case series.