- Discussion:
- diagnosis: limb is shortened, internally rotated, and adducted;
- Thompson and Epstein Classification:
-
Type I: w/ or w/o a minor fracture
-
Type II: w/ large single frx of post. acetabular rim;
-
Type III: w/ comminution of rim of acetubulum w/ or w/o major frag;
-
Type IV: w/ a fracture of the acetabular floor
-
Type V: w/ a fracture of the femoral head;
-
associated injuries:
- prior to closed reduction the surgeon must be aware of all associated injuries;
- Radiographic Evaluation of Hip Dislocation::
- AP of the Hip;
-
pelvic series radiographs (
AP,
inlet and outlet);
-
acetabular series radiographs (
Judet views);
- radiograph of the femur and knee;
- Closed Reduction of Posterior Hip Dislocations:
- Arthroscopic Removal of Loose Hip Joint Fragments:
- note that this technique is potentially dangerous due to the possibility that fluid may extravasate thru an associated
acetabular frx, which would cause it to accumulate in the pelvis and abdomen;
- references:
-
Hip arthroscopy for osteochondral loose body removal after a posterior hip dislocation
-
Arthroscopy for hip dislocation and fracture-dislocation.
- Open Reduction of Posterior Dislocations:
- Post-Reduction Radiographic Assesment:
- once closed reduction is obtained, carefully flex hip to 90 deg (if hip dislocates, it is unstable and reqires open reduction);
-
radiographs:
- need to asses for congruency w/ repeat of pre-reduction radiographs;
- any widening of the joint space after reduction should suggest the possibility of loose fragments in the joint
incomplete reduction of a fractured femoral head fragment, or soft tissue interposition;
- objective measurements include the distance from the femoral head to the ilioischial line compared to the contralateral hip;
-
CT scan:
- always get post reduction CT scan to r/o iatrogenic
posterior wall frx;
- 2 mm slices are required to help asses congruence;
- note the distance of anterior joint surface to femoral head as compared to the contralateral side;
- more than 0.5 mm difference is signifiant;
- small fragments which are located inferiorly, away from the wt bearing dome, do not necessarily need to be removed if the joint is congruent;
- post reduction 3 anatomical areas should be assessed;
- femoral head;
- femoral neck;
- acetabulum;
- Post Reduction Treatment of Stable Dislocation:
- avoid: flexion, internal rotation, and adduction;
- have abduction pillow present prior to closed reduction;
- traction is maintained until patient is pain free (1-2 wks)
- if needed,
femoral traction pin may used for traction;
- Complications:
- Chondrolysis
- Degenerative Joint Disease:
- may occur in the majority of patients that sustain dislocation;
-
Heterotopic Ossification
- may occur in the majority of patients with Pipkin III and IV frx;
- a relative contra-indication of XRT may be posterior hip dislocation w/ femoral head frx, since there is a theoretical risk of contributing to AVN or non-union;
-
AVN after Hip Dislocation:
- incidence of AVN is 15% in posterior dislocation;
- incidence of AVN is approx 4% in anterior dislocation;
Hip Dislocation: Current Treatment Regimens. Paul Tornetta III MD and H.R. Mostafavi MD. J Am Acad Orthop Surg 1997; 5:27-36
Operative Management of Displaced Femoral Head Fractures: Case Matched Comparison of Anterior versus Posterior Approaches for Pipkin I and Pipkin II Fractures; MF Swiontkowski, M Thorpe, JG Seiler, and ST Hansen. J. Orthop Trauma. Vol 6. No 4. pp 437-442. pp 1992.
Computed tomography evaluation of stability in posterior fracture dislocation of the hip. Clin Orthop 1988;227:152-163. Zych GA, Latta L, et al:
Stability of posterior fracture-dislocation of the hip. Keith JE, Brashear HR Jr, Guilford WB: J Bone Joint Surg 1988;70A:711-714.
Reduction of posterior dislocation of the hip in the prone position. Herwig-Kempers A. Veraart BE. Journal of Bone & Joint Surgery - British Volume. 75(2):328,1993 Mar.
Radiologic classification of posterior dislocations of the hip: refinements and pitfalls.
Traumatic posterior fracture-dislocation of the hip with fracture of the femoral head or neck, or both.
Predictors of clinical and radiological outcome in patients with fractures of the acetabulum and concomitant posterior dislocation of the hip.
Plastic Deformation and Impaction of Retroacetabular Surface Associated w/ Posterior Fracture-Dislocation of Hip: Description of 2 Cases.
