Prevalence, Progression, and Clinical Impact of Stem Notching in Ceramic-on-Ceramic Total Hip Arthroplasty: A Minimum 15-Year Follow-Up Study.

BACKGROUND

Stem notching, resulting from impingement between the femoral stem and ceramic liner in ceramic-on-ceramic (CoC) total hip arthroplasty (THA), has been linked to adverse outcomes such as ceramic-related noise and ceramic component fractures. Despite its potential significance, its true incidence is infrequently documented, and the long-term clinical impact remains uncertain. This study aimed to assess the minimum 15-year outcomes and complications associated with stem notching in CoC THA.

METHODS

We performed a retrospective cohort analysis of patients who received CoC THA between November 1997 and December 2003, with a minimum follow-up period of 15 years. Stem notching was diagnosed using radiographic evaluation and was observed in 21.5% of cases (63 of 293). The lesions were monitored for an average of 12.5 years from detection (range, one to 23.2). The primary endpoints included changes in notch depth and the occurrence of ceramic-related complications such as ceramic component fractures and noise generation. The secondary outcomes involved functional evaluation via the modified Harris Hip Score.

RESULTS

Notch depth did not demonstrate meaningful progression beyond five years after identification. Lower cup inclination and higher anteversion were associated with the presence of notching. The incidence of ceramic component fractures was 6.3% in notched hips compared to 4.3% in hips without notches (P = 0.509), while noise was noted in 25.4% of notched hips and 22.6% of non-notched hips (P = 0.618). Functional assessment revealed similar outcomes between those who did and did not have notches (mean modified Harris Hip Score: 89.3 versus 91.2; P = 0.103).

CONCLUSIONS

Stem notching in CoC THA is a relatively common, but often overlooked phenomenon. Most notches remained stable over time and were not associated with inferior functional outcomes. Although hips with notches showed a higher rate of ceramic-related noise and head fractures, these differences were not statistically significant. Clinicians should recognize this finding, maintain routine follow-up, and reassure patients that a notch alone does not pose any immediate problem.

LEVEL OF EVIDENCE: Level III, retrospective therapeutic study.