Osteochondroplasty of the femoral head in hip reconstruction for type II late sequelae of septic arthritis: a preliminary report.

PURPOSE

To suggest different procedures tailored for hip reconstruction in type II late sequelae of septic arthritis.

METHODS

The severely deformed subluxated or dislocated femoral head is reshaped in accordance to radiographic and on-table assessment (osteochondroplasty). Sixteen hips in 13 patients (three bilateral) were the subject of this study. They were all affected during incubation in the first few weeks after birth. Age at operation was in the range 2-12 years (average 5.3). The main complaint was instability, stiffness during walking and the inability to sit comfortably, limb length discrepancy, and mild pain on walking. Preoperatively, the range of motion was limited to a certain degree in different directions in all cases. Plain radiography, computed tomography (CT), or multi-slice CT with reconstruction 3D views were of benefit in analyzing the problem preoperatively. Magnetic resonance imaging (MRI) was performed for selected cases after 2 years to test for the viability of the femoral head.

SURGICAL TECHNIQUE

A modified approach was used to adequately expose the iliac bone, the hip, and the upper third of the femur. Meticulous dissection to preserve the amalgamated capsule and a well-planned capsulotomy for later adequate capsulorrhaphy is essential. Debridement to clear the acetabulum from intra-articular fibrosis is attempted prior to acetabular reconstruction (Salter, Dega, or triple pelvic osteotomy). Head and neck reconstruction (osteochondroplasty) is performed according to the nominated topography of the deformed head (beard, collared, staghorn, etc.). A carefully planned reshaping in a manner not disturbing the superior weight bearing articulating surface with the acetabulum will allow easy containment in the reconstructed acetabulum. Associated subluxation or dislocation will dictate adequate shorting with femoral cuts inclined in a manner bringing the impinging overgrown greater trochanter down, achieving a near to normal neck shaft angle.

RESULTS

According to the criteria proposed by Hunka et al. (Clin Orthop Relat Res 171:30-36, 1982), a satisfactory result is considered when a stable pain-free hip is achieved with flexion arc >70 degrees and flexion contracture <20 degrees . This was true in 13 hips. It appears that better results are achieved in younger children with minimal intra-articular adhesions limiting hip movements, and with less destruction of the articular cartilage. A final improvement in the range of movement should not be expected before 6-12 months. Intensive physiotherapy to improve postoperative stiffness is required.

CONCLUSION

The proposed reconstruction procedure for reshaping the deformed femoral head (osteochondroplasty) is a salvage attempt that achieved a more or less mobile painless stable hip joint besides restoring the normal anatomical relationship, should total hip replacement (THR) be needed in the future.