This is the editor's interpretation of the above paper published in the orthopaedic literature in 1987 - our attempt to make relevant medical articles accessible to lay readers. If you want to read the original it is easy to ask your librarian to obtain a reprint for you from any medical library.
The authors of this paper highlighted that IPCS could be either 'primary' (arising on its own) or 'secondary' to one or more of a group of conditions - (immobility, quads insufficiency, poorly positioned cruciate ligament replacements, infection, RSD, an entrapped meniscus, or a neuromuscular disorder (such as polio). These conditions may be associated with a flexion deformity but initially a mobile patella However, if the condition persists a fibrotic (scarring) process may set in, and the patella may then become immobile (entrapped) and then this would then be considered as 'secondary IPCS'.
They made the following points and recommendations for treatment -
For Stage I they recommended aggressive rehabilitation with early motion, and patellar mobility exercises to be taught to the patient. They emphasized getting the quads active, using as needed muscle stimulation, anti-inflammatories, analgesics (pain killers) and TENS (electrical nerve stimulation).
If the patient was not achieving extension a drop-out cast or extension board could be used with caution (both physically stress the knee into extension) - but only once the quads were working again. It was suggested that manipulation under anaesthesia (MUA) should also be used with caution and only in the very early stages. They recommend that these forced extension procedures should not be used for more than 3-5 days. In their experience most patients in the early stages would generally respond to this programme, but 5% were still likely to progress to Stage II and require surgery. They considered this 5% to represent 'primary' arthrofibrosis.
Once it is apparent that no progress is being made and that the patient has entered Stage II, they recommended that attempts at forced passive extension be discontinued and that the patient should be treated surgically.
They made a point that they did not think arthroscopic surgery likely to be useful, and recommended open intra-articular and extra-articular debridement (clean up of scar tissue) and release (cutting bands of scar tissue). They felt the timing of this surgery was critical to avoid operating when there was inflammation and the quads were weak - and they felt it valid to wait for some months to achieve this, working meanwhile on regaining strength within the available ROM.
Opening the joint on both sides of the patella, their recommendations for surgery included lateral release, debridement of the fat pad and lateral and medial patellomeniscal ligaments, and cleaning out the notch of the femur, removing any cruciate graft if the problem had come on after cruciate reconstruction and the graft had been incorrectly placed. They recommended that adhesions around the patellar tendon and the suprapatellar pouch should be excised, and patellar mobility restored with a patellar tilt test producing at least 45 degrees of tilt. They recommended that the surgeon be prepared to do a tibial tubercle transfer (moving the tubercle up) if patella infera was present.
They did not mention the use of drains, but did insist that all wounds should be meticulously closed. Prophylactic antibiotics were used, as well as anti-inflammatories. If steroids were to be used, these were avoided until after the wounds had healed. CPM was started postoperatively, and the use of epidural for pain relief was encouraged, with a drop-out cast at night for a few days.