Outcomes of total knee replacement in young Chinese patients

Abstract

Introduction:

This study aimed to assess the outcomes and implant survivorship in Chinese patients aged 55 years or younger.

Methods:

We reviewed our local joint replacement registry on a total of 102 knees from 68 Chinese patients aged 55 years or below at the time of surgery. All patients were operated on from January 2000 to July 2007. The mean followup was 8.3 years (range, 5 ? 12.5 years). We included patients with osteoarthritis (70 knees), rheumatoid arthritis (24 knees), hemophilia (4 knees), psoriatic arthropathy (1 knee), post?traumatic (1 knee) and tuberculosis (2 knees). All implants were cemented. 53 were posterior cruciate ligament (PCL) sacrificing, 47 were posterior stabilized implants and 1 was constrained implant. The preoperative and latest Knee Society Knee Scores, Knee Society Functional Score, knee range of motion and lower limb mechanical alignment on long film measurement were obtained. The postoperative occurrence of radiolucent lines, complications, revision operation and deaths were noted. Each knee was analyzed separately.

Results:

Mean Knee Society Knee Score improved from 41 (range: 13?79, SD 12.9) to 88 (range: 30?100, SD 13.3)(p <0.0001), while the mean Knee Society Functional Score improved from 41 (range: 0?80, SD 19.2) to 69 (range 0?100, SD 26.5 ) (p<0.0001). 70% achieved a postoperative coronal mechanical axis of within 3 from neutral alignment. Implant survivorship was 97% at 5 years and 85% at 10 years. 11 knees from 9 patients had complications requiring revision surgery. Aseptic loosening occurred in 10 knees of 8 patients. Among those with aseptic loosening, 3 knees from different patients had coexisting osteolysis. Heterotopic ossification occurred in 1 knee. There were no cases of infection.

Rheumatoid arthritis patients when compared with osteoarthritis patients had a more valgus preoperative lower limb alignment (p<0.001), a lower mean preoperative KSFS (30 and 45 respectively, p=0.004) and a lower mean postoperative KSFS (53 and 74 respectively, p=0.006). There were no significant differences in mean improvement of KSFS, KSKS, radiological outcomes and implant survival.

There were no statistically significant differences in clinical outcomes, radiological outcomes and implant survival between PCL sacrificing and PCL substituting implants.

There were no statistically significant differences between the postoperatively neutrally aligned group and the outlying group in terms of clinical outcomes, radiological outcomes and implant survival.

Conclusion:

Total knee arthroplasty provides good clinical and functional outcomes in young Chinese comparable to those of international standards. Careful patient selection is crucial to avoid complications.