In a clinical study reported by Kevin B. Fricka, MD, Anderson Orthopaedic Clinic, Alexandria, Virginia, USA, patients receiving total knee arthroplasty (TKA) using cementless fixation had similar clinical and functional scores and equivalent levels of satisfaction compared with those receiving cemented TKA after 2 years.

Cemented TKA is associated with excellent long-term survival and is the preferred approach for the majority of surgeons. Cementless TKA, while having favorable long-term results on the femoral side [Baker PN et al. J Bone Joint Surg Br. 2007], has been associated with failure related to the tibial or patellar components. This was a prospective single-surgeon study designed to assess clinical outcomes, patient satisfaction, and long-term (15 years) survival in 92 TKA patients randomized to cemented (n = 45) or cementless (n = 47) fixation. The cementless implants consisted of a porous fiber-metal mesh femoral component and a trabecular metal modular tibial component; the cemented implants were precoated femoral and tibial components. All designs were fixed bearing and cruciate retaining. Knee Society Scores and Oxford Knee Scores were collected prior to surgery and at 4 weeks, 4 months, and 1 and 2 years. Pain was assessed using a visual analog scale preoperatively and at 4 weeks and 4 months. Alignment was assessed using radiographic analysis. Postoperative complications were recorded. All patients received routine antibiotic and aspirin prophylaxis, and all had identical rehabilitation protocols.

The cementless approach was associated with a shorter surgical time (74 vs 81 minutes) but no difference in blood loss. Early pain scores (at 4 months) were higher, but not significantly so, in the cementless group. Dr Fricka suggested that this was likely due to the time needed for osseointegration. Knee Society Scores showed no difference in function at 2 years, but patients in the cemented group had slightly higher clinical scores (96.3 vs 92.3; P = .3). Oxford Knee Scores and patient-reported satisfaction, pain levels, and improved function were similar. There were 2 revisions: 1 in the cementless group for instability and 1 in the cemented group for infection. Overall limb alignment was similar on radiographic analysis (Table 1). A nonprogressive radiolucency was identified in 11 patients in the cementless group (vs none in the cemented group). Varus subsidence of the tibia was noted in 4 knees in the cementless group; none have required revision. Of the 11 patients who had staged bilateral TKA with 1 cemented and 1 cementless fixation, 9 patients had no preference, and 2 preferred the cementless design.

This study is limited by its small sample size (although it was sufficient to perform a power analysis) and short follow-up. Additional follow-up is planned for these patients at 5, 10, and 15 years to assess whether cementless fixation provides an overall survivorship advantage.