Joint-preserving surgery improves pain, range of motion, and abductor strength after Legg-Calvé-Perthes disease

Abstract

Background: Patients after Legg-Calvé-Perthes disease (LCPD) often develop pain, impaired ROM, abductor weakness, and progression of osteoarthritis (OA) in early adulthood. Based on intraoperative observations during surgical hip dislocation, we established an algorithm for more detailed characterization of the underlying pathomorphologies with a proposed joint-preserving surgical treatment.

Questions/purposes: We asked if patients after LCPD treated with our algorithm experienced (1) reduced pain; (2) improved hip function; and/or (3) prevention of OA progression; we then determined (4) the intraoperative damage patterns; (5) the survival of the hip; and (6) factors predicting the need for a conversion to THA; radiographic progression of OA; a Merle d'Aubigné-Postel score below 15 at last followup; and/or the need for revision surgery.

Methods: We retrospectively reviewed 53 patients after LCPD who underwent joint-preserving surgery (40 surgical hip dislocations, eight acetabular osteotomies, four combined procedures, and one intertrochanteric osteotomy). We obtained Merle d'Aubigné-Postel scores to assess pain; OA was assessed using Tönnis grades. Survival and predictive factors were calculated with the univariate Cox regression. Fifty of the 53 patients were evaluated at a minimum of 5.1 years (mean, 8.2 years; range, 5.1-12.8 years).

Results: Pain and hip function improved at followup from a median of 4 points to 5 points. The mean increase in Tönnis grades at last followup was 0.3 to 0.8. The survival of surgery at 5 years was 86%; 13 factors related to survival.

Conclusion: Patients with symptoms resulting from pathomorphologic deformities after LCPD benefit from joint-preserving surgery with specific treatment of individual structural abnormalities.

Fig. 1

The morphologic analysis with the corresponding surgical treatment algorithm of hips with pathomorphologic sequelae of Legg-Calvé-Perthes disease is shown. SHD = surgical hip dislocation; PAO = periacetabular osteotomy.

Fig. 2

The results for intraoperative femoral head damage are shown. To describe the exact location of the chondral damage on the femoral head, the head was divided into eight sectors of a sphere. The numbers represent the frequency of chondral damage in each of the eight sectors.

Fig. 3

The Kaplan-Meier survival analysis is shown. End points were defined as conversion to a THA, reoperation for correction of acetabular coverage or femoral offset, progression of osteoarthritis, or an insufficient clinical result defined as end points. Values are expressed as cumulative survival of surgery with 95% confidence intervals in parentheses.

Fig. 4

The results for intraoperative chondrolabral damage of the acetabulum are shown. A clock system was used to describe the exact location of the chondrolabral damage on the acetabulum. Six o’clock was located at the acetabular notch. All findings were converted to the right side with 3 o’clock consistently representing the most anterior portion of the acetabulum.

Fig. 5A–D

The radiographs of a 16-year-old female patient are shown in the (A) AP projection and (B) crosstable projection. Next to the deformity of the femoral head (Grade III according to Stulberg), a high-riding trochanter, a positive sagging rope sign, and acetabular retroversion were present. The acetabular index was 4°. (C) A surgical hip dislocation with relative lengthening of the femoral head, distalization of the greater trochanter, and (D) osteochondroplasty of the femoral head neck junction was performed. The acetabular retroversion was not addressed to avoid joint instability. Eleven years postoperatively, the patient presented with a Merle d’Aubigné-Postel score of 18 points without signs of radiographic progression of osteoarthritis and full abductor strength.

Fig. 6A–C

The radiographs of a 43-year-old patient with Legg-Calvé-Perthes disease are shown. (A) Preoperatively, the patient presented with pain, a severe Trendelenburg limp, and decreased abduction, internal, and external rotation. (B) A surgical hip dislocation with relative lengthening of the femoral head, distalization of the greater trochanter and osteochondroplasty, and acetabular rim trimming with refixation of the labrum was performed. (C) Five years after surgery, the patient presented with severe progression of osteoarthritis and migration of the femoral head.