SCFE: Reduction vs Pinning in Situ

- Discussion:
    - arguments for closed reduction:
          - closed reduction reduces the severity of the slip and facilitates screw placement;
          - references:
                - Slipped capital femoral epiphysis. The case for internal fixation in situ.
                - Reduction of epiphyseal displacement and fixation in the treatment of unstable slipped capital femoral epiphysis.
                - Closed reduction and pinning for acute slipped capital femoral epiphysis.
                - Early reduction, arthrotomy, and cannulated screw fixation in unstable slipped capital femoral epiphysis treatment.

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    - arguments for pinning in situ: (no reduction)
          - reduction may damage blood supply causing AVN;
          - osteonecrosis occurrs most often in unstable slips which are the ones most amenable to reduction;
          - as noted by Tokmakova et al. "complete or partial reduction of an unstable slipped capital femoral epiphysis increases the chance that
                  osteonecrosis will develop.   Pinning in situ with a single cannulated screw is the method of choice for the treatment of a SCFE,
                  regardless of whether it is stable or unstable... every effort should be made to avoid reduction whether intentional or inadvertent;"
          - in the response to Tokmakova et al.,   Unni G. Narayanan has noted, that "the authors may well be right, but their conclusions cannot
                  be made on the basis of the analyses that they present in their paper."
          - in counter-response R.P. Stanton et al point out that "that the question of whether the slip severity or slip reduction is more or less
                  responsible for the development of avascular necrosis is not material to the actual care of the patient... For purposes
                  of discussion, let us assume that the severity of the slip is 80% responsible for the development of avascular necrosis and the reduction
                  of the slip prior to pinning is only 20% responsible. In this hypothetical scenario, the conclusion of our article is still valid.
                  The factor over which the treating surgeon has control—i.e., the choice to reduce or not to reduce the slip prior to pinning—is all that matters."
          - references:
                  - Factors Influencing the Development of Osteonecrosis in Patients Treated for Slipped Capital Femoral Epiphysis. Tokmakova et al. (2003;85:798-801)  
                  - Letter to the Editor. Reduction Increasing Osteonecrosis Risk in Slipped Capital Femoral Epiphysis.
                  - Slipped capital femoral epiphysis in southern Sweden. Long-term.
                  - Traction reduction of acute and acute-on-chronic slipped capital femoral.