Cineplastic muscle tunnels and prostheses, made according to present technological methods in selected patients are generally adequate. Causes of failure in cineplastic prosthesis wearers are many, and in given instances there may be several. Those encountered in this series were, in order of their importance:
1. Injudicious selection of candidates.
2. Lack of patient cooperation in learning to use the prosthesis (as a corollary to 1).
3. In the forearm the technical impossibility of constructing muscle tunnels with sufficient strength and excursion.
4. Recurrent excoriation of tunnel skin, with resulting narrowing and sometimes, closure of the skin tube orifice.
5. Rotation of prosthesis on shoulder when tunnelled muscle is contracted.
6. Insufficient transmission of force through cable system.
7. Limitation of excursion because of re-attachment of severed distal end of canalized muscle to deep tissue.
8. Patients' lack of real need for a prosthetic device.
Prerequisites for successful use of cineplasty tunnels are:
1. A mature, intelligent, well adjusted patient. In general he should not beengaged in heavy labor. He should have observed others who have had cineplasty, and ask for the operation. He should have exhibited good use of a conventional device for six months. Only in exceptional circumstances should cineplasty be done before the patient is fifteen years old.
2. A competent prosthetist who will make a well functioning and properly fitted device is essential.
3. Preoperatively, an adequate progra of joint mobilization and muscle strengthening, and postoperatively, training in post-fitting prosthetic use is mandatory.
4. When a biceps tunnel is contemplated, an amputation stump should be well muscled, covered by good skin exhibiting normal nerve innervation, and there should be relatively normal shoulder motion.
5. Daily tunnel hygiene.
We believe that, mad each of the patients reviewed in this series been screened by a prosthetic team, a number of operations which were profitless to the patient would have been avoided.