Purpose of the study: We analysed the clinical and radiographic outcomes of 113 cemented total knee arthroplasties (TKA) with resurfaced patella implanted in 83 patients with rheumatoid arthritis who were reviewed 1 to 12 years after implantation. Mean follow-up was 5.86 years. All implants were posterior stabilised (HLS) implanted by one operator using the same procedure.

Material and methods: One hundred seventy-two rheumatic arthritis patients underwent TKA from 1996 to 2007. At last follow-up, 68 could not be contacted, 11 had died, 9 declined review. The review was conducted in 2008 for 83 patients, 113 TKA. Female gender predominated (86.4%) and 29 patients (32.6%) had two TKA. Mean age at revision was 67.6 years.

Results: Seventy patients (84.4%) were satisfied or very satisfied with their prosthesis. The knee score (IKS) improved from 31.58 (0–63) preoperatively to 86.21 (59–99) postoperatively; the function score (IKS) improved from 31.7 (0–100) preoperatively to 77.12 (0–100) postoperatively. The improvement was significant for both scores. Men preoperative flexion was 97 (35–125) versus 112.1 (30–130) postoperatively. Ten knees presented anterior pain at revision (8.8%). The postoperative femorotibial mechanical angle was 180.72 (173–192). The mean femoral mechanical angle was 91.3 (78–99); the mean tibial mechanical angle was 89.4 (52–110). Men postoperative patellar height was 0.79 (0.24–2) measured with the Blackburn index. The patella was centred for 87.6% (99 knees) and subluxated laterally for 12.1% (14 knees). There were no loosening. Two arthroplasties had to be revised surgically (1.8%): one for infection (two-phase replacement with a hinged prosthesis) and one for patellar fracture treat by osteosynthesis. Two patients developed a postoperative phlebitis (2.4%).

Discussion: This study demonstrates the good mid-term outcomes achieved with a cemented posterior stabilised TKA in patients with rheumatoid arthritis. These results are nevertheless slightly less satisfactory than with TKA implanted for degenerative disease: this might be explained generally by disease-related impact on the functional result. Prosthetic surgery of the knee remains the treatment of choice for advanced arthritic degeneration.

This study is a retrospective monocentric analysis of changes in spinopelvic sagittal alignment after in situ fusion of L5-S1 spondylolisthesis. In situ fusion is a safety procedure with good functionnal outcome, but the consequences on the spinopelvic sagittal balance remains unclear. The aim is to evaluate the adaptative changes in the sagittal balance after such treatment.

This is an analysis of 22 patients (mean age 13,5 years) with an average follow-up of 5,2 years (range 1–11 years). This study includes 6 grade II spondylolisthesis, 7 grade III and 9 grade IV. 13 patients were operated with a non instrumented posterolateral arthrodesis and 9 with a circumferential in situ fusion. Among the 13 grade II and III spondylolisthesis, 12 had a posterolateral arthrodesis and only 1 had a circumferential fusion. As for the grade IV spondylolisthesis 8 out of 9 had a circumferential arthrodesis and only 1 had a posterolateral fusion.

Before and after surgery, all patients had lateral standing radiographs of the spine and pelvis. Different parameters were evaluated before surgery: pelvic incidence, sacral slope, pelvic tilt, lumbar lordosis, thoracic kyphosis, T9 sagittal tilt, L5 incidence, L5 slope and L5 tilt. After surgery, the pelvic parameters were not evaluated because of the difficulty to visualise the upper part of S1 after arthrodesis. The discs were evaluated by MRI.

The functionnal outcome was evaluated with the Oswestry score.

A global evaluation including all the patients doesn’t show any influence of the surgery on the sagittal alignment. But when evaluating the datas after classifying the patients in function of the severity of the spondylolisthesis, some differences raise. On one side, the patients with grade II and III spondylolisthesis keep a normal T9 sagittal tilt while slightly increasing lumbar lordosis and thoracic kyphosis. On the other side, the patients with grade IV spondylolisthesis operated with a circumferential in situ fusion worsen the T9 sagittal tilt, increase the L5 incidence, decrease their lombar lordosis (L4/L5 discal kyphosis) and thoracic kyphosis.

To conclude, we can say that patients with grade II and III spondylolisthesis have good functionnal outcome and keep a balanced spine. Patients with grade IV have a good clinical outcome as well but keep worsening their sagittal balance despite the circumferential in situ fusion. An unbalanced sagittal alignment might theorically compromise the long term clinical results, but the radiological outcome doesn’t seem to be linked to the functionnal outcome. A long term follow-up has to be done in order to evaluate the outcome of these unbalanced spines and compare it to the functionnal and radiological results obtained with reduced high grade spondylolisthesis.