13.1 Grading of chondromalacia according to Outerbridge [106]
Outerbridge described in 1961 the macroscopic aspect of changes of the articular cartilage for the articular surface of the patella. Meanwhile this classification is generally used for the description of articular cartilage lesions.
The macroscopic changes of chondromalacia can be classified into four grades:
n In grade 1 there are softening and swelling of the cartilage.
n In grade 2 there are fragmentation and fissuring in an area half an inch or less in diameter.
n Grade 3 is the same as grade 2 but an area more than half an inch in diameter is involved.
n In grade 4 there is erosion of cartilage down to bone.
13.2 Classification of glenoid morphology in primary glenohumeral osteoarthritis according to Walch et al. [134]*
The authors classified the glenoid morphology into three types base on the CT scan findings out of 113 patients (Fig. 53). Intraobserver repro- ducibility and interobserver reliability were good with a kappa index that ranged from 0.65 to 0.70.
n Type A (59%): the humeral head was centred, and the resultant strengths were equally distributed against the surface of the glenoid.
Glenoid retroversion averaged 11.58 (standard deviation [SD], 8.88).
The erosion may be minor ± type A1 (43%) ±or major ±type A2
Classifications of Osteoarthritis of the shoulder
13
(16%) marked by a central erosion that led to a centred glenoid cu- pula. In advanced cases, the humeral head protruded into the glenoid cavity.
n Type B (32%): the humeral head was subluxated posteriorly, and the distributed loads were asymmetric. The CT scan revealed numerous anatomic changes, more pronounced on the posterior margin of the glenoid. The retroversion averaged 188 (SD, 7.28). Two subgroups were identified: B1 (17%) showed narrowing of the posterior joint space, subchondral sclerosis, and osteophytes, and B2 (15%) demon- strated a posterior cupula that gave an unusual biconcave aspect of the glenoid. In type B2, there was an excessive retroversion of the glenoid according to Friedman et al. [41], but the value of the retro- version does not explain the biconcavity of the glenoid.
n Type C (9%): this type of glenoid morphology was defined by a gle- noid retroversion of more than 258, regardless of the erosion. The retroversion was of dysplastic origin, and the humeral head was well centred or slightly subluxated posteriorly. The average retroversion was 35.78 (SD, 5.98).
156 13 Classifications of Osteoarthritis of the shoulder
Fig. 53. Different morphological types of the glenoid in primary glenohumeral os- teoarthritis
13.3 Assessment of humeral head subluxation according to Walch et al. [134]
The position of the humeral head with respect to the glenoid was evalu- ated using an index of subluxation, which is the relative part of the hu- meral head posterior to the bisecting line of the glenoid (Fig. 54). An index between 45 and 55% represents a centred humeral head, 0% is an anterior dislocation, and 100% is a posterior dislocation.
Index=D/E
13.4 Classification of vertical glenoid morphology according to Habermeyer [51a]*
In the true antero-posterior view the authors identified four different types of inclination deformity of the glenoid due to a vertical line per- pendicular to the inferior border of the X-ray film along the lateral base
Fig. 54. Method used to evaluate the humeral head subluxation. A Line tangent to the anterior and posterior edges of the glenoid fossa. B Line bisecting the glenoid.
C Line parallel to A transecting the medial third of the humeral head. D Relative part of the humeral head posterior to B. E Diameter of the humeral head on line C. D, E, Index of subluxation. An index between 45 and 55% indicates a well-centred humer- al head. An index of more than 55% indicates posterior subluxation and below 45%
indicates anterior subluxation
of the coracoid (coracoid baseline) and along the superior and inferior glenoid rim (glenoid line).
In this investigation the coracoid baseline is reproducible because the ap-view is taken into a standardized standing position of the patient, so that the inferior border of the X-ray film is parallel to the bottom and the lateral base of the coracoid does not change with rotation of the sca- pula.
Type 0 (Fig. 55a) represents normal glenoids; the coracoid baseline and the glenoid line run parallel. Both lines intersect below the inferior glenoid rim in type 1 (Fig. 55b) glenoids. In type 2 (Fig. 55c) glenoids, 158 13 Classifications of Osteoarthritis of the shoulder
Fig. 55. Classification of glenoid inclination. a Inclination type 0: the coracoid base- line (red) and the glenoid line (blue) run parallel (the brown line represents the inferi- or border of the X-ray film). b Inclination type 1: the coracoid baseline and the gle- noid line intersect below the inferior glenoid rim. c Inclination type 2: the coracoid baseline and the glenoid line intersect between the inferior glenoid rim and the cen- tre of the glenoid. d Inclination type 3: the coracoid baseline and the glenoid line in- tersect above the coracoid base
a b
c d
the coracoid baseline and the glenoid line intersect between the inferior glenoid rim and the centre of the glenoid. In type 3 (Fig. 55d) glenoids the lines intersect above the coracoid base.
13.5 Classification of osteoarthritis with massive rotator cuff tears according to Favard et al. [38]*
n Group 1: is characterised by upward migration of the humeral head, superior gleno-humeral joint space narrowing, an acromion changed in shape due to the imprint of the humeral head and subacromial ar- thritis (Fig. 56a).
n Group 2: this group is characterised by central gleno-humeral joint space narrowing and with little alteration in the shape of the acro- mion which does not have a humeral head imprint (Fig. 56b).
n Group 3: this group is characterised by signs of bony destruction in the form of lysis of either the head or the acromion. The bony ele- ments not affected by the lysis do not undergo any modification in their shape, for example, the greater tuberosity is not eroded and the acromion does not have a humeral head imprint. Gleno-humeral joint space narrowing is either minimal or nonexistent (Fig. 56c).
Fig. 56. a Group 1. Superior glenohumeral wear: upward migration of the humeral head. Acromion modification with inferior concavity wear. b Group 2. Central narrow- ing of the glenohumeral joint. Little alteration in the shape of the acromion without humeral head imprint. c Group 3. Lysis of either the humeral head or the acromion
a b c
There was no age difference between the three groups. The acromio-hu- meral joint space narrowing was significantly greater in group 1 than in group 3 and 2.
13.6 Classification of cuff tear arthropathy according to Seebauer et al. [132]
Analysis of cuff tear arthropathy and failed treatment has led to a bio- mechanical classification of cuff tear arthropathy. Four distinct groups have been formed on the basis of the biomechanics and clinical out- comes of arthroplasty. The four types are distinguished by the degree of superior migration from the centre of rotation and the amount of insta- bility of the centre of rotation. This classification (Table 5) has proposed benefits in surgical decision-making for optimal implant type, goals of reconstruction, and outcomes.
160 13 Classifications of Osteoarthritis of the shoulder
Table 5. Classification of cuff-tear arthropathy. (From [132]) Type IA:
centred stable (Fig. 57a)
Intact anterior restraints
Minimal superior migration
Dynamic joint stabilization
Acetabularization of coracoacromial arch and femoralization of humeral head Type IB:
centred medialized (Fig. 57b)
Intact anterior restraints;
force couple intact/
compensated Minimal superior migration
Compromised dynamic joint stabilization
Medial erosion of the glenoid, acetabulari- zation of coracoacromial arch, and femoralization of humeral head Type IIA:
decentred limited stable (Fig. 57c)
Compromised anterior restraints; com- promised force couple
Superior
translation Insufficient dynamic joint stabilization
Minimum stabilization by coracoacromial arch, superior-medial erosion and extensive acetabularization of coracoacromial arch and femoralization of humeral head Type IIB:
decentred unstable (Fig. 57d)
Incompetent anterior structures
Anterior superior escape
Absent dynamic joint stabilization
No stabilization by coracoacromial arch;
deficient anterior structures
13.7 Classification of cuff tear arthropathy according to Hamada et al. [55] (Fig. 58a±e)
Roentgenographic grades of massive cuff tears were proposed. These were based chiefly on the acromiohumeral interval (AHI), which has been considered in the literature to be a sensitive indicator for the full- thickness cuff tear. Five grades were classified:
n Grade 1: the AHI was more than 6 mm
n Grade 2: the AHI was 5 mm or less
n Grade 3: acetabularization was added to the Grade 2 characteristics (The term acetabularization is defined as a concave deformity of the acromion undersurface. It has two subtypes:
±an excavating deformity of the acromion
±a deformity formed by the excessive spur along the coracoacromial ligament)
Fig. 57. Biomechanical classification of cuff-tear arthropathy. a Type IA: centred, stable. b Type IB: centred, medialized. c Type IIA: de-centred, limited stabilization.
d Type IIB: de-centred unstable. (From [132])
a b
c d
n Grade 4: narrowing of the glenohumeral joint was added to the Grade 3 features
n Grade 5: comprised instances of humeral-head collapse, which is characteristic of cuff-tear arthropathy
13.8 Classification of glenoid erosion in glenohumeral osteoarthritis with massive rupture
of the cuff according to Sirveaux et al. [120]
Radiological the authors defined four types of glenoid erosion. In type E0, the head of the humerus migrated upwards without erosion of the glenoid. Type E1 was defined by a concentric erosion of the glenoid. In type E2 there was an erosion of the superior part of the glenoid and in type E3 the erosion extended to the inferior part of the glenoid (Fig.
59).
162 13 Classifications of Osteoarthritis of the shoulder
Fig. 58. Radiological classification of cuff-tear arthropathy. A Grade 1; B grade 2;
C grade 3; D grade 4; E grade 5. (From [55])
13.9 Radiographic classification of dislocation arthropathy of the shoulder
according to Samilson and Prieto [117]
The authors examined seventy-four shoulders with a history of single or multiple dislocations of the shoulder demonstrated radiographic evi- dence of glenohumeral arthropathy.
Radiographic evidence of arthrosis was graded as mild, moderate, or severe evaluated in the anteroposterior radiograph.
n Mild arthrosis was indicated by evidence on the anteriorposterior radiograph of either an inferior humeral or glenoid exostosis, or both, measuring less than 3 mm in height (Fig. 60a).
n Moderate arthrosis was indicated by evidence on the anteroposterior radiograph of either an inferior humeral or glenoid exostosis, or both, between 3 and 7 mm in height, with slight glenohumeral-joint irregularity (Fig. 60b).
Fig. 59. Radiological classification of glenoid erosion in osteoarthritis with massive rupture of the cuff. (From [120])
n Severe arthrosis was indicated by evidence on the anteroposterior radiograph of either an inferior humeral of glenoid exostosis, or both, that was more than 7 mm in height, with narrowing of the glenohumeral joint and sclerosis (Fig. 60c).
164 13 Classifications of Osteoarthritis of the shoulder
Fig. 60. Radiological classification of dislocation arthropathy. a Mild arthrosis evi- dence on the anteroposterior radiograph of an inferior humeral or glenoid exostosis, or both, measuring <3 mm. b Moderate arthrosis evidence on the anteroposterior radiograph of an inferior humeral or glenoid exostosis, or both, measuring between 3 and 7 mm, with slight glenohumeral-joint irregularity. c Severe arthrosis evidence on the anteroposterior radiograph of an inferior humeral or glenoid osteosis, or both, measuring >8 mm, with glenohumeral narrowing and sclerosis. (From [117])
a b c
