Learning curve of basic hip arthroscopy technique: CUSUM analysis.
OBJECTIVE
Hip arthroscopy is known to have a steep learning curve by measuring operation times or complication rates. However, these measures are arbitrary and are based on the number of procedures performed rather than clinical outcomes. Recently, Cumulative sum (CUSUM) analysis has been used to monitor the performance of a single surgeon by evaluating clinical outcomes. Our purpose was to determine the learning curve for basic hip arthroscopy technique using CUSUM technique.


METHODS
Forty consecutive patients who underwent hip arthroscopy were evaluated. Modified Harris Hip Score less than 80 at 6 months postoperatively was considered as treatment failure. Patients were chronologically stratified in two groups (the early group--cases 1-20, and the late group--cases 21-40), and age, gender, body mass index, and operation time were compared in both group. CUSUM analysis was then used to plot the learning curve.


RESULTS
Eight patients (20 %) experienced treatment failure. Although there was no significant difference of treatment failure rate between the early and late groups (30 vs. 10 %, n.s.), the operation time was shorter in the late group (p = 0.014). In addition, CUSUM analysis showed that failure rates diminished rapidly after 21 cases and reached an acceptable rate after 30 cases.


CONCLUSIONS
Surgeon's experience is an important predictor of failure after hip arthroscopy, and CUSUM analysis revealed that a learning period is required to become proficient at this procedure, and that experience of approximately 20 cases is required to achieve satisfactory outcomes in terms of clinical outcomes. Surgeon can use the present learning curve for self-monitoring and continuous quality improvement in hip arthroscopy.


METHODS
Retrospective case series, Level IV.
Department of Orthopaedic Surgery, Seoul National University Bundang Hospital, 166 Gumi-ro, Bundang-gu, Seongnam, 463-707, South Korea.
Young-Kyun
YK
Lee
Yong-Chan
YC
Ha
Deuk-Soo
DS
Hwang
Kyung-Hoi
KH
Koo
D000328:Adult; D001182:Arthroscopy / Q000379:methods*; D005260:Female; D006621:Hip Joint / Q000601:surgery*; D006801:Humans; D059032:Learning Curve; D008297:Male; D015233:Models, Statistical; D061646:Operative Time; D012189:Retrospective Studies; D017211:Treatment Failure