RESULTS OF 226 CHARITE III DISC ARTHROPLASTY DONE IN 160 PATIENTS WITH AN AVERAGE FOLLOW UP OF 79 MONTHS

Abstract

Aim: To analyse clinical, radiological & survival results of Charite III Disc Replacement.

Study Design: Ethical committee approved retrospective study.

Methodology: 160 patients (Av. Age 46yrs; Std.Dev 8.06; 62 Males & 98 Females) who underwent disc replacement surgery through transperitoneal approach using a midline incision, between Jan1990 and Dec2000 were identified from hospital records. An independent observer administered Oswestry Disability Index, Pain Score by telephone at the time of review (Aug2003) and reviewed Clinical and radiographic features that were recorded in pre designed form.

Results: Clinical: At an average follow up of 79 (range 31 to 161) months, mean improvement in ODI and pain score were 18.01(p< 0.001) and 1.69(p< 0.001) respectively. Radiological: Movement between the disc spaces, defined as greater than 4 degree on flexion-extension lateral view was preserved after surgery at L4L5 (4.01 degree) & L5S1(4.8 degree) level but not at L3L4( 1.5 degree) level. Average disc height was 19.7mm, and gross radiological loosening was observed after 04, Facet osteoarthritis after 65 and Heterotrophic ossification after 23 operations. Survival: Kaplan-Meier survival analysis showed mean survival time of 147(95% C.I. 140 to 154) months with cumulative survival of 55% at 156 months with implant removal as an endpoint. A mean survival time of 124(95% C.I. 116 to 133) months with cumulative survival of 35% was observed with all radiological failures as an endpoint. Complications: Commonest complication was post-operative incisional hernia seen in 17(10.6%) patients. Other complications were: post-operative ileus 4(2.5%), wound infection 9(5.6%) and retrograde ejaculation in 5(3.1%) patients.

Conclusion: Charite III Disc Replacement results in a clinical significant (> 15, p< 0.001) improvement in ODI, it however does not result in clinical significant (> 2 points) improvement in back pain.Preservation of motion is of questionable clinical significance and it has low survival. Prospective studies are required to confirm the efficacy of this technique