Trauma-instability-voluntarism classification for glenohumeral instability

Epidemiology of the Frequency, Etiology, Direction, and Severity (FEDS) system for classifying glenohumeral instability

HYPOTHESIS

The purpose of this multicenter epidemiologic study was to determine the distribution of patients within the Frequency, Etiology, Direction, and Severity (FEDS) classification system to determine which categories are of clinical importance.

METHODS

Shoulder instability patients were identified using International Classification of Diseases, Ninth Revision coding data from 3 separate institutions from 2005-2010. Data were collected retrospectively. Details of instability were recorded in accordance with the FEDS classification system. Each patient was assigned a classification within the FEDS system. After all patients were assigned to a group, each group was individually analyzed and compared with the other groups.

RESULTS

There are a total of 36 possible combinations within the FEDS system. Only 16 categories were represented by at least 1% of our patient population. Six categories captured at least 5% of all patients with shoulder instability. Only 2 categories represented greater than 10% of the population: solitary, traumatic, anterior dislocation, with 95 patients (24.8%), and occasional, traumatic, anterior dislocation, with 63 patients (16.4%).

CONCLUSIONS

There are 16 categories within the FEDS classification that are clinically significant. Solitary, traumatic, anterior dislocation and occasional, traumatic, anterior dislocation were the most frequently observed in our cohort.

Functional outcome and quality of life after rehabilitation for voluntary posterior shoulder dislocation: a prospective blinded cohort study

BACKGROUND

Voluntary posterior instability of the shoulder is a rare condition in which the patient is able to cause a subluxation by voluntary muscle activation. A shoulder rehabilitation program aimed to correct abnormal muscle patterns and restore correct scapular motion may provide good results and improve the quality of life of these patients.

METHODS

Fifteen subjects (six males, nine females; mean age 19 years) underwent physical examination and clinical tests [Disability of the Arm, Shoulder and Hand (DASH) score, Shoulder Pain and Disability Index (SPADI), and modified Rowe score] and compiled the patient global assessment (PGA). Articular or rotator cuff lesions were excluded by X-rays and MRI. The rehabilitation program included three phases: (1) assessment and correction of abnormal muscle patterns, (2) restoration of correct scapular motion, and (3) strengthening of scapular and posterior glenohumeral muscles. Follow-up was at 3, 6, 12, and 24 months.

RESULTS

DASH and SPADI scores improved significantly at 3 (p < 0.01), 6 (p < 0.009), 12 (p < 0.001), and 24 months (p < 0.001). The Rowe score was fair at 3 months and good at 6, 12, and 24 months. Active flexion, abduction, and external rotation increased at all follow-up points (p < 0.01), whereas internal rotation remained unchanged (p > 0.05). PGA values were high. Compliance was good without serious adverse events reported during the treatment. A correlation was found between age and DASH changes (Spearman's ρ -0.56; p = 0.0455).

CONCLUSIONS

Our findings stress the value of a rehabilitation program that teaches subjects with voluntary instability how to correct abnormal muscle patterns to restore scapular motion, and the importance of adopting home rehabilitation exercises as a part of the normal lifestyle.

Anterior dislocation of the shoulder in skeletally immature patients

The ideal treatment for traumatic anterior dislocation of the shoulder in the skeletally immature patient is controversial. The aim of this study is to evaluate the outcomes after either conservative and/or surgical treatment using the Latarjet technique. A retrospective series of 49 out of 80 patients were reviewed. We found no significant differences between either treatment method regarding functional scores and pain levels. Although not statistically significant, post-surgical patients showed better signs of shoulder stability than others who have a higher rate of recurrence. Further, 92% of the post-surgical group had returned to the same level of activity versus 52% in the non-surgically treated group. We found no contraindications to operate on a skeletally immature patient.

Cite this article: Bone Joint J 2014;96-B:354–9.

Development and reliability testing of the frequency, etiology, direction, and severity (FEDS) system for classifying glenohumeral instability

HYPOTHESIS

Classification systems for glenohumeral instability (GHI) are opinion based, not validated, and poorly defined. The hypothesis driving this investigation is that a classification system with content validity will have high inter-observer and intra-observer agreement.

MATERIALS AND METHODS

The classification system was developed by first conducting systematic literature review that identified 18 systems for classifying GHI. The frequency of characteristics used was recorded. Additionally, 31 members of the American Shoulder and Elbow Surgeons responded to a survey to identify features important to characterize GHI. Frequency, etiology, direction, and severity (FEDS) were most important. Frequency was defined as solitary (1 episode), occasional (2 to 5 times/y), or frequent (>5 times/year). Etiology was defined as traumatic or atraumatic. Direction referred to the primary direction of instability (anterior, posterior, or inferior). Severity was subluxation or dislocation. For reliability testing, 50 GHI patients completed a questionnaire at their initial visit. One of 6 sports medicine fellowship-trained physicians completed a similar questionnaire after examining the patient. Patients returned after 2 weeks and were examined by the original physician and 2 other physicians. Interrater and intrarater agreement for the FEDS classification system was calculated.

RESULTS

Agreement between patients and physicians was lowest for frequency (39%; κ = 0.130) and highest for direction (82%; κ = 0.636). Physician intrarater agreement was 84% to 97% for the individual FEDS characteristics (κ = 0.69-0.87), and interrater agreement was 82% to 90% (κ = 0.44-0.76).

CONCLUSIONS

The FEDS system has content validity and is highly reliable for classifying GHI. Physical examination using provocative testing to determine the primary direction of instability produces very high levels of interrater and intrarater agreement.

Classification of glenohumeral joint instability

Shoulder instabilities have been classified according to the etiology, the direction of instability, or on combinations thereof. The current authors describe a classification system, which distinguishes between static instabilities, dynamic instabilities, and voluntary dislocation. Static instabilities are defined by the absence of classic symptoms of instability and are associated with rotator cuff or degenerative joint disease. The diagnosis is radiologic, not clinical. Dynamic instabilities are initiated by a trauma and may be associated with capsulolabral lesions, defined glenoid rim lesions, or with hyperlaxity. They may be unidirectional or multidirectional. Voluntary dislocation is classified separately because dislocations do not occur inadvertently but under voluntary control of the patient.

Atraumatic shoulder instability. Discussion of classification and results after capsular imbrication

This study consists of 27 shoulders in 24 patients whose atraumatic shoulder instability was treated with the imbrication procedure described by Rockwood. Follow-up after 2 years or more showed the following results: 37% excellent, 30% good, 15% fair and 18% poor (Rowe score). No statistically significant differences in the results were observed between the dominant and non-dominant arm, nor in post-operative return to sports activities. Those with voluntary instability had more laxity at follow-up and tended to have poorer results. Those with unidirectional laxity had only good or excellent results and showed no post-operative laxity. We found no other reliable indication of the results of surgery. The difficulties of classifying shoulder instability by such factors as trauma, laxity and direction of instability are discussed. Overall, we consider capsular imbrication to be a good treatment for involuntary atraumatic shoulder instability.