LOS ANGELES — Although patients with mild to borderline dysplastic hip morphologies experienced improved functional scores after arthroscopy, they had inferior good to excellent scores and higher failure rates compared with a femoroacetabular impingement cohort, according to a presenter here.
“Functional scores improved post arthroscopy in hips with mild to borderline dysplastic morphologies, but when compared to the [femoroacetabular impingement] FAI cohort, good to excellent results were inferior and failure rates were higher,” James Ross, MD, said in his presentation at the Arthroscopy Association of North America Annual Meeting.
Ross and colleagues retrospectively reviewed 88 hips (71% female) with radiographs consistent with dysplasia and a mean 26 months follow-up after hip arthroscopy. Researchers used modified Harris Hip Scores, SF-12 scoring and VAS pain score to evaluate patient function, and evaluated patient demographics, procedures and radiographic parameters with regards to functional outcomes. Patients with dysplasia were compared to an aged matched cohort of 231 hips that underwent arthroscopic FAI correction without dysplasia and had a mean follow-up of 22.7 months.
Overall, 76% of patients underwent labral repairs, 23% underwent labral debridements, 82% underwent capsular plications and 72% underwent associated femoral resections.
Ross and his colleagues found a mean preoperative lateral center edge angle of 21° and a Tonnis angle of 11° in patients in the dysplastic cohort.
“When you look at the lateral alpha angle [postoperatively], this significantly improved from 56° mean preoperatively to 44° postoperatively,” Ross said.
He noted a similar trend in the head neck offset ratio, with improvement from 0.16 to 0.19, as well as improvement in cross over sign from 44% of the patients preoperatively to 8% of the patients postoperatively.
Comparing patients in the dysplastic cohort to the FAI cohort, Ross noted improvement of Harris Hip Score in both groups. However, the FAI cohort had an improvement of 24 points vs. 16 points in the dysplastic cohort. The final mean modified Harris Hip Score was 88 points in the FAI cohort vs. 81 points in the dysplastic cohort, according to study results. The FAI cohort also had higher good and excellent results at 81% vs. 61% in the dysplastic cohort.
Radiographic parameters showed the dysplastic cohort had no correlation with the final modified Harris Hip Score or the change in the modified Harris Hip Score. However, according to Ross, patients who underwent capsular plication and labral repair experienced higher good to excellent results, a greater mean latest modified Harris Hip Score and lower failure rates.
“There was no statistical significance in any difference in either cohort for functional outcomes regarding gender or age,” Ross said. “More importantly, there was no iatrogenic subluxations or dislocations in either group.”
Larson C, et al. Paper #SS-34. Presented at: Arthroscopy Association of North America Annual Meeting. April 23-25, 2015; Los Angeles.
Disclosure: Ross reports no relevant financial disclosures.