Contact between the glenoid and the humeral head in abduction, external rotation, and horizontal extension: a new concept of glenoid track.

Imbalance of the internal and external rotator musculature of the shoulder, excess capsular laxity, and loss of capsular flexibility, have all been implicated as etiologic factors in glenohumeral instability and impingement syndrome; however, these assertions are based largely on qualitative clinical observations. In order to quantitatively define the requirements of adequate protective synergy of the internal and external rotator musculature, as well as the primary capsulolabral restraints, we prospectively evaluated 53 subjects: 15 asymptomatic volunteers, 28 patients with glenohumeral instability, and 10 patients with impingement syndrome. Range of motion was evaluated by goniometric technique in all patients with glenohumeral instability and impingement. Laxity assessment was performed and anterior, posterior, and inferior humeral head translation was graded on a scale of 0 to 3+. Isokinetic strength assessment was performed in a modified abducted position using the Biodex Clinical Data Station with test speeds of 90 and 180 deg/sec. Internal and external rotator ratios and internal and external rotator strength deficits were calculated for both peak torque and total work. Patients with impingement demonstrated marked limitation of shoulder motion and minimal laxity on drawer testing. Both anterior and multidirectional instability patients had excessive external rotation as well as increased capsular laxity in all directions. Sixty-eight percent of the patients with instability had significant impingement signs in addition to apprehension and capsular laxity. Isokinetic testing of asymptomatic subjects demonstrated a 30% greater internal rotator strength in the dominant shoulder. Comparison of all three experimental groups demonstrated a significant difference between internal and external rotator ratios for both peak torque and total work. Conclusions are that there appears to be a dominance tendency with regard to internal rotator strength in asymptomatic individuals. Impingement syndrome and anterior instability have significant differences in both strength patterns of the rotator muscles and flexibility and laxity of the shoulder. Isokinetic testing potentially may be helpful in diagnostically differentiating between these two groups in cases where there is clinical overlap of signs and symptoms.

Patterns of flexibility, laxity, and strength in normal shoulders and shoulders with instability and impingement

Eleven patients with ankylosing spondylitis had severe disabling kyphosis with forward bending of the upper part of the spine The kyphosis was corrected by osteotomy by removal of a wedge composed of the spinous processes and the neural arch of the second lumbar vertebra and by excision of bone from the inside of the posterior part of the vertebral body of L2 By hyperextending the spine, a wedge fracture occurs in the vertebral body, producing lordosis and correction of the deformity without an anterior opening of the lumbar discs

Vertebral osteotomy for correction of kyphosis in ankylosing spondylitis.

The avulsion of the glenohumeral ligament labral complex at the glenoid (Bankart lesion), as well as ligamentous laxity are well known causes of anterior shoulder instability A lesser known entity, the humeral avulsion of glenohumeral ligaments (HAGL), was studied to determine its incidence and its role in anterior glenohumeral instability Sixty-four shoulders with the diagnosis of anterior instability were prospectively evaluated by arthroscopy for intraarticular pathology, including Bankart, capsular laxity, and HAGL lesions Six shoulders were found to have HAGL lesions (93%), 11 shoulders with generalized capsular laxity (172%), and 47 shoulders with Bankart lesions (735%) In patients with documented anterior instability without a demonstratable "primary" Bankart lesion, a HAGL lesion should be ruled out This lesion is readily recognized arthroscopically, and an appropriate repair of this lesion can restore anterior stability to the patient The pathological anatomy of the HAGL lesion and our treatment of this lesion is discussed

Humeral avulsion of glenohumeral ligaments as a cause of anterior shoulder instability

Study Design.Clinical, radiographic, and outcomes assessment comparing two surgical techniques. Clinical data were collected prospectively. The radiographic analysis was done retrospectively.Objectives.Smith-Petersen (chevron type) osteotomy (SPO) and pedicle subtraction osteotomy (PSO) have been us

Comparison of Smith-Petersen Versus Pedicle Subtraction Osteotomy for the Correction of Fixed Sagittal Imbalance

A review of the pathology, mechanism, and operative treatment of recurrent dislocation of the shoulder, based on an analysis of 180 cases, with 159 operations, is presented. From this analysis the following conclusions have been made and appear to be substantiated: 1. The pathology comprises two important elements: ( a ) anterior detachment of the glenoid labrum from the bone margin of the glenoid, associated with some degree of stripping of the anterior part of the capsule from the front of the neck of the scapula, found in 87 per cent. of cases examined adequately at operation; ( b ) defect or flattening of the posterolateral aspect of the articular surface of the head of the humerus which engages with the glenoid cavity when the arm is in external rotation and abduction; this defect is demonstrated most readily in antero-posterior radiographs taken with the humerus in 60 to 70 degrees of internal rotation and was shown to be present in 82 per cent. of cases which had been subjected to adequate radiographic examination. 2. The frequency of the humeral head defect has been under-estimated in the past, because of the difficulty of demonstrating it, particularly when the defect is small. 3. Either type of lesion alone may predispose to recurrence of the dislocation. 4. Both types of lesion are often present in the same shoulder. When this is the case the tendency to redislocation is great. 5. The initial dislocation, which results in the development of one or both these persistent structural abnormalities, may be due to very different types of injury, the commonest of which is a fall on the outstretched hand. The factor common to all these injuries is a resultant force acting on the humeral head in the direction of the anterior glenoid margin. 6. In the treatment of recurrent dislocation of the shoulder joint the Nicola operation is unreliable, and it may be associated with a recurrence rate as high as 36 per cent. It is believed that continued instability after this operation is usually due to the presence of a defect of the humeral head. 7. Operative treatment should aim at repairing, or nullifying, the effects of both types of lesion. For anterior detachment of the labrum this involves either suturing the labrum back to the glenoid margin, or constructing some form of anterior buttress, fibrous or bony: for humeral head defects it necessitates some procedure designed to limit external rotation, thus preventing the defect from coming into engagement with the glenoid cavity. Such limitation of external rotation does not constitute a significant disability.

Recurrent dislocation of the shoulder

1. The steps of the operation of spinal osteotomy, as carried out with the patient in the lateral posture, are described. 2. Details of post-operative management are given. 3. The major risks of the operation are discussed and precautions suggested.

Technique, dangers and safeguards in osteotomy of the spine.

One hundred and sixty-four cases of intramedullary nailing of the long bones have been studied with special reference to the difficulties and complications encountered. There was one death not attributable to the method. Two cases of pulmonal fat embolism and one case of thrombosis occurred, all in fractures of the femur. The lessons we have learned from our mistakes can be summarised as follows: 1 . The method requires technical experience and knowledge and is not suited to inexperienced surgeons or surgeons with little fracture material at their disposal. 2. Intramedullary nailing should only be used in fractures to which the method is suited. In general, comminuted fractures or fractures near a joint are unsuitable. 3. Open reduction is preferable to closed methods. 4. The nail should never be driven in with violence. It should be removed and replaced with a new one if difficulty is encountered when inserting it. 5. In fractures of the femur the nail should be driven in from the tip of the trochanter after careful determination of the direction. 6. The nail should be introduced only to the level of the fracture before exploring and reducing the fracture. 7. Distraction of the fragments must be avoided. 8. If the nail bends it should be replaced by a new one, at least in femoral fractures. 9. If union is delayed, the fracture should be explored and chip grafts of cancellous bone placed around it. 10. Improvised nails or nails which are not made of absolutely reliable material should never be used. 11 . Make sure that the nail is equipped with an extraction hole for removal.

Medullary nailing of fractures after fifty years

1. The unreliable results of the conventional cup arthroplasty are attributed to mechanical imperfections in the reconstructed joint. 2. If its reliability can be improved, there will remain a place for cup arthroplasty, which, in relatively young and active patients, offers advantages over prosthetic replacement arthroplasty. 3. A technique of concentric cup arthroplasty is described. The new joint is shaped with precision to exact dimensions and lined with a cup designed to ensure stability, concentric movement and a uniform clearance between the moving parts. 4. The results so far are encouraging and justify continued clinical trial.

J. Crawford Adams

Papers

Recurrent dislocation of the shoulder

Technique, dangers and safeguards in osteotomy of the spine.

Medullary nailing of fractures after fifty years

A reconsideration of cup arthroplasty of the hip, with a precise method of concentric arthroplasty.