Neuropathy of the Suprascapular Nerve Before and After Reconstruction of the Cuff
Condition: Cuff Rotator Full Thickness Tear; Cuff Rotator Syndrome
Study type: Interventional

Summary: 
      The suprascapular nerve innervates the musculi supra- and infraspinatus, which, as part of
      the rotator cuff, allow lifting and external rotation in the shoulder joint. Damage to this
      nerve can lead to pain and functional deficit. Causes of injury are compression by bony /
      ligamentous anomalies, fracture sequelae and traction damage. In the literature, a (often
      subclinical) traction damage is increasingly claimed by a muscle retraction after rupture of
      the supra- and / or infraspinatus tendon as a cause of pain and functional disturbances. The
      retraction of the ruptured tendon-muscular unit is said to lead to traction damage of the
      nerve, which can be demonstrated by pathological EMG derivations. By repositioning the tendon
      to its outbreak site, the nerve is occasionally overstretched, so that individual authors
      propagate a routine nerve decompression as prophylaxis. In individual cases, a previously
      pathologic EMG result could be improved after reconstitution of an rotator cuff rupture.
      However, prospective studies are not available.

      It is not known how often a nerve damage is present before a rotator cuff operation and it is
      not known how often the tendon repair leads to nerve damage or recovery of damage. It is not
      known whether the surgical nerve decompression is associated with reduced postoperative pain
      and what a profit or what risks bring about a routine decompression of the nerve to the
      patient. To answer this question, this prospective randomized study is to be carried out.
    

Detailed description: 
      On the basis of preoperative electromyography (EMG) and electroneurography (ENG), the
      investigators would like to determine the frequency of suprascapular neuropathy in ruptures
      of supra- and / or infraspinatus tendons and the risk factors for their presence.

      In a ruptured rotator cuff, the muscle is partly retracted so much that the innervating nerve
      (suprascapular nerve) is stretched and has pathological neurological findings. The
      Investigators now want to analyze how the arthroscopic reconstruction of the nasal
      suprascapular nerve affects the pre-operative neuropathy. Does the pre-existing nerve recover
      by decompression (liberation) from surrounding / entangling tissue or does decompression have
      no influence on measurable neurology? Other patients with rotator cuff ruptures have normal
      neurological findings preoperatively despite severe retraction of the muscular / tendon unit.
      In these cases, the investigators are interested in whether the mobilization and
      reconstruction of the torn muscle / tendon unit leads to a neurologically measurable
      elongation of the nerve. This nerve stretching is a possible explanation for protracted
      postoperative pain. With the postoperative electrophysiological measurements we can quantify
      this nerve change.

      The comparison between preoperative and postoperative neurology findings allows confirmation
      or refutation of our hypothesis.
    

Intervention name(s): Release or no release of the suprascapular nerve
Intervention type(s): Procedure
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment