Abstract
PURPOSE: The purposes of this study were to investigate (1) the clinical, radiographic and arthroscopic presentation of patients with subchondral insufficiency fracture of the femoral head (SIFFH) and (2) the outcomes following arthroscopic treatment with internal fixation using hydroxyapatite poly-lactate acid (HA/PLLA) threaded pins and concomitant arthroscopic treatment of associated findings. METHODS: Nine patients (median age 49.0 years, range 43-65, five female and four male patients) with SIFFH who underwent arthroscopic treatment with labral repair, capsular closure and internal fixation of SIFFH using HA/PLLA pins were retrospectively reviewed. Inclusion criteria were adult patients with precollapse SIFFH with minimum 1-year follow-up (median follow-up 30.0 months, range 12-56). RESULTS: Acetabular labral tears were observed in all patients. The median BMI was 24.3 kg/m(2) (range 20.1-31.8). Clinical presentations and radiographic measurements demonstrated mixed type FAI in six patients, borderline developmental dysplasia in two patients and pincer type FAI in one patient. The median MHHS significantly improved from preoperatively (67.1, range 36.3-78.0) to post-operatively (96.8, range 82.5-100; p = 0.001). The median NAHS significantly improved from preoperatively (34.0, range 17-63) to post-operatively (78.0 range 61-80; p = 0.001). CONCLUSION: SIFFH is associated with bony deformities and labral tears. Precollapse SIFFH can be treated with bioabsorbable pin stabilization of unstable lesions and treatment of associated intra-capsular pathology in those with stable lesions as determined by a new arthroscopic classification system with promising early outcomes. LEVEL OF EVIDENCE: IV.