1. Periacetabular Osteotomy: Intra-articular Work Department of Orthopaedic surgery, University of Toronto, Toronto, Ontario, Canada,
Hip and Pelvis Clinic , Chonbuk University Hospital , Jeonju, Korea .

2. Background Periacetabular Osteotomy
- Goal : Improvement of hip biomechanics by reorienting the acetabulum
→ postpone degenerative progression
Desire of improvement
Potential for overcorrection

3. Background Overlooked intra-articular hip inspection
Overcoverage of femoral head
→ iatrogenic FAI
Overlooked chondrolabral injury
(dysplasia, FAI)
Overlooked intra-articular hip inspection
(early experience)
Complications of PAO
Prevalence %
Authors
Acetabular cartilage delamination
28 of 64 hips
44%
CLP
Labral injury
22%
Siebenrock et al
Labral tearing+/-degeneration
63 of 73 hips
86.3%
Ross et al
Hypertrophied labrum
46 of 73 hips
63%
Acetabular retroversion
25 of 95 osteotomies
26%
Dora et al

4. Intra-articular Work Labral pathology
The acetabular labrum
- a triangular structure with a basilar attachment to the osseous
acetabular rim
- a capsular insertion along the external surface
- a free intra articular apical margin
Dysplastic hip pathomorphology
FAI-pincer type
FAI-cam type
Labral tissue hypertrophy with myxoid degeneration and/or detachment from the osseous acetabular rim
Undersurface labral tearing without hypertrophy
Labral tearing -extends perpendicular to the labral surface
Labral tearing-
at the transition(fibrous cartiliginous labrum/articular hyaline cartilage) zone perpendicular to the articular surface
Transition zone : between fibrocartilaginous labrum and the articular hyaline cartilage
Labral injury alone could generate sufficient pain to require intervention
The positive outcome- pain relief after debridement and/or fixation of labral tears,

5. Intra-articular Work Labral pathology
Labral repair with suture anchor
: TOC for unstable hypertrophied labrum
Anterior hip arthrotomy
Modified Smith-Petersen approach used for Bernese PAO
Indirect head of rectus femoris is tagged and mobilized for improved view
Capsular incision along the long axis of the femoral neck → AP direction at the level of acetabular rim
Simple debridement
Labral repair using suture anchor technique is used for labral detachment at the extra-articular osseous insertion
Labral detachment → Preservation of the blood supply

6. Intra-articular Work Labral pathology

7. Intra-articular Work Labral pathology
Labral takedown and Rim resection
Labral refixation with suture anchors fixed to new acetabular rim
Correction achieved

8. Intra-articular Work Chondral pathology
Chondral lesion
- Location : anterior and superolateral aspect of acetabulum
- Size : mm2
Chondromalacic, cleavage, or debonding injury

9. Intra-articular Work Chondral pathology
The natural history of these lesion and whether chondral lesions are independent source of pain have not been determined.
Nascent chondral lesions identified at the time of PAO represent an opportunity to alter the degenerative cascade.

10. Intra-articular Work Chondral pathology
In contrast with labral pathology, preOP diagnosis of chondral injury has implications for preOP planning
- Hip MR Arthrography : mainstay of soft-tissue hip diagnostic imaging
(Specificity ↑, Sensitivity ↓)

11. Intra-articular Work Chondral pathology
Inspection
: Patient’s specific hip pathophysiology
Diagnostic imaging
2. Rim resection
Amount of rim resection to properly address the chondral lesion
Staged surgical dislocation → PAO
Obtain consent for a possible simultaneous PAO

12. Intra-articular Work Chondral pathology

13. Femoral head-neck offset
More than 90% of patients treated with PAO require some degree of femoral head-neck offset correction
→ Intraoperative C-arm fluoroscopy
(False profile view, Dynamic impingement view)
Assess
Intended acetabular correction
Femoral head-neck offset
Potential exacerbation of FAI

14. Femoral head-neck offset
Cam lesion on femoral head-neck junction
burr allows adequate restoration of the femoral head-neck offset
Adequate offset achieved