Why Use CPM Therapy?

Published: October 3, 2017

Continuous Passive Motion (CPM) Therapy

Experimental investigations in the 1970s provided the scientific basis for CPM treatment using motor-driven exercise equipment. Positive clinical experience, with this exciting therapeutic modality being well received by surgeons, therapists and patients, accelerated its widespread acceptance. Forty years later, advances in technology and the extension of this form of post-surgical rehabilitation therapy to new indications and protocols demonstrate that CPM still plays an integral and significant role in orthopaedic recovery. For the patient, it is a valuable and well-tolerated method of rapidly restoring lost joint function, mobility and confidence.

It is important to review the key clinical outcomes from Professor Robert Salter’s pioneering animal work. He used rabbits with the following pathologies:

  • – Full thickness cartilage defects
  • – Acute septic arthritis
  • – Intra-articular fractures
  • – Partial thickness tendon lacerations 

Rabbits with full thickness cartilage defects were divided into three treatment groups with therapy instituted immediately postoperatively as follows:

  • – Immobilisation with a cast
  • – Intermittent active motion (cage activity)
  • – Continuous passive motion


  • – The immobilised group showed healing characterised by the formation of fibrous tissue and many joint adhesions.
  • – The cage activity group showed imperfect healing characterised by a combination of fibrous tissue and poorly differentiated cartilage.
  • – The CPM group showed healing through formation of new hyaline-like cartilage occurring in one half of the defects within four weeks. CPM did not harm intact, normal living articular cartilage in rabbits.

The benefits of CPM for healing cartilage:

  • – Enhanced nutrition and metabolic activity
  • – Accelerated healing of articular tissues
  • – Regeneration of cartilage

The benefits of CPM for healing tendons:

  • – Restoration of the tendon’s gliding surface
  • – Greater mean breaking strength of the tendon
  • – Enhanced intrinsic healing through synovial diffusion
  • – Prevention of adhesion formation

CPM therapy is cost-effective because it…

  • – Increases joint mobility and range of motion
  • – Helps decrease complications such as joint stiffness and adhesions
  • – Reduces the length of post-operative hospitalisation, and
  • – Builds patient confidence, well-being and independence

Indications for the Knee & Hip

  • – Knee replacement surgery
  • – Fractures (ie patellar, tibia plateau, femoral)
  • – Arthrolysis
  • – Hip surgery, including hip replacement, hip pinning, osteotomy
  • – Ligament repairs
  • – Arthroscopic surgery (ie menisectomies, patellectomies) – Burns, joint sepsis

Indication for the Shoulder

  • – Total shoulder replacement
  • – Repeated dislocation of the humerus
  • – Rotator cuff injury
  • – Upper humerus fractures
  • – Scapula fractures
  • – Acromioplasty
  • – Capsulotomy
  • – Arthrolysis
  • – Synovectomy for Rheumatoid Arthritis
  • – All types of shoulder stiffness

Indications for the Elbow

  • – Intra-articular fractures of the elbow with Open Reduction and Internal Fixation (ORIF)
  • – Metaphyseal fractures in elbow area with ORIF
  • – Arthrolysis for post-traumatic stiffness with limitation of elbow joint motion
  • – Release for extra-articular adhesions
  • – Prosthetic elbow joint replacement
  • – Synovectomy of the elbow
  • – Arthrotomy and drainage of acute septic elbow Joint

Indications for the Hand & Wrist

  • – Flexor and extensor tendon tenolysis
  • – Aponeurectomies for Dupuytrens disease
  • – Open reduction and internal fixation of intra-articular diaphyseal, metaphyseal and epiphyseal fractures of the phalanges
  • – MCP arthrolysis
  • – Prosthetic replacement of the MCP, PIP and DIP joints
  • – Rheumatoidal/neurological or post-burn for stiffness
  • – Capsulotomies, arthrolysis and tenolysis for post-traumatic stiffness of MCP, PIP and DIP joints
  • – Synovectomies

Indications for the Ankle

  • – Passive mobilisation of the following fractures after internal fixation
  • – Mobilisation of the joints of the foot after operative or conservative treatment of lesions of the: Achilles tendon, Lateral collateral ligament, Medial collateral ligament
  • – Surgical lengthening of the achilles tendon for post-traumatic stiffness
  • – Club foot