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Wheeless' Textbook of Orthopaedics
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Chondromalacia of the Patella



- See: Patella and Patellofemoral Function:

- Discussion:
      - chondromalacia describes softening & fissuring of articular hyaline cartilage;
      - chondromalacia may result from an excessive load on patellofemoral joint, but disuse may be a contributing factor;
      - most common in yound women;
      - relationship between chondrosis & subsequent arthrosis is unclear;
      - contributing factors:
            - weakness and tightness of quadriceps muscle;
            - genu valgum;
            - increased Q angle
            - patella alta


- Clinical Features and Exam:
      - pts may report anterior knee pain, esp. while climbing stairs;
      - compression of patella may cause pain along medial & lateral retinacula & patellar ligament;
      - compression of the patella during flexion & extension of knee may elicits crepitation and discomfort;
      - patellar tracking
            - best seen when examiner is seated in front of pt & takes knee through full passive and active ROM.
      - crepitus:
            - may be a normal finding in young people;
      - misc signs:
            - excessive tibial rotation
            - foot pronation


- Radiograpic Features:
      - is best seen on a slightly over exposed lateral x-ray;
      - axillary radiograph will determine which facet is involved;
      - usually it will involve the medial facet;
      - Agliettis et. al. Clin. Ortho 1983
            - 53 patients w/ chondromalacia:
            - Q angle was 20 deg (versus 15 deg;)
            - LT/LP differed only in the males = 1.08 versus 1.01
            - congruence angle = - 2 deg (sig diff. for males and fem)


- Stages:
          - I:   swelling and softening of the cartilage;
          - II:   fissuring w/in the softened areas
          - III: fasciclations of articular cartilage almost to level of subchondral bone;
          - IV:   destruction of cartilage w/ subchondral bone exposed;
                    - histologically, stage IV is virtually indistinguishable from DJD;
                    - there is no unequivical progression from stage I to IV;


- Non Operative Treatment:
    - reduced strenuous activities;
    - exercises to stretch & strengthen quadriceps muscle are started;
    - avoid stressing   the painful arc of motion;
    - immobilization is a contributing cause of chondromalacia and its contributing cause of chondromalacia & its subsequent symptoms;
    - reference: Physical Therapy for Patellofemoral Pain


- Operative:
      - debridement: little proven benefit;
      - lateral retinacular release:
            - little proven benefit if chondromalacia is 2nd to patella alta;
      - distal realignment procedures:
            - as noted by Morshuis et al, distal realignment procedures result in satisfactory results in about 2/3 patients
                    who have patellofemoral pain and x-ray evidence of arthrosis but nearly all patients w/ patellofemoral pain
                    w/o x-ray evidence of arthrosis had good or excellent results;





Miyakawa patellectomy

An electron microscopic study of early pathology in chondromalacia of the patella;

Resurfacing of the knee with fresh osteochondral allograft.

Treatment of chondromalacia patellae by lateral retinacular release of the patella.

Insall proximal realignment for disorders of the patella.

Chondromalacia Patellae. A prospective study.

Long-term results for the McKeever patellar resurfacing prosthesis used as a salvage procedure for severe chondromalacia patellae.

Chondralmalaciapatella in athletes: Clinical preservation and conservative management.
      DeHaven KE, Dolan WA, Mayer PJ:     Am J Sports Med 1989;7:5.

Physical Therapy for Patellofemoral Pain. A Randomized, Double-Blinded, Placebo-Controlled Trial.




















Original Text by Clifford R. Wheeless, III, MD.