Purpose of study

To study the effect of different shoes and orthotics have on patellar tendon tensile forces.

Patellar tendinopathy is an overuse injury that affects tennis players and in high impact sports like basketball, volleyball and running has an incidence of 20%. The tensile forces in the patellar tendon can be reliably measured with an intratendinously placed fibre optic tube and wireless transmission device allows for dynamic testing. The biggest strain differentials have been confirmed in jumps from 30cm height. Tennis is played on 3 major different court surfaces and there is a variety of commercially designed tennis shoes on the market.

The management of bony lesions associated with glenohumeral instability has been open to debate. Invariably a significant period of time elapses between injury and surgery during which the bony fragment may atrophy and reduce both in size and in quality. Histomorphometric bone analyses were prospectively performed on the glenoid bone fragments harvested during the modified Latarjet operation. The main purpose of the study was to assess the viability of the bone. Biopsies were obtained from 21 patients that had given informed consent. Median age was 21 years (range 16–50). All were male patients. The most important sports identified were rugby (64%) and water sports (surfing, water polo, water skiing, surfing (21%)). Mean glenoid bone loss on CT scan was 17% (range 10–50%). Thirty-three percent had bone loss greater than 20%. Gross morphology of glenolabral fragments identified a single large fragment (11/21); dominant large fragment plus smaller fragments (7/21); multiple fragments (4/21). Single large fragments comprised 52% of the study. Mean volume and mass of bony fragments were 2.18 ml (range 1–3 ml) and 1.64 gms (range 0.43–2.8 g), respectively. Histology of the specimens revealed no bone in three of the 21 specimens. Bony necrosis was present in 8/18 (44%) of the specimens. From a histopathological point of view, reattachment of these devitalized bone fragments by screws or anchors may result in predictable operative failure and recurrent instability. We can therefore not support the practice of “repair” of bony Bankart lesions based on the above findings.

External rotation of the shoulder is commonly measured in two ways, with the arm adducted or with the arm abducted to 90°. The measurement forms an important part of the assessment of shoulder function, but has been shown to be unreliable. Following the observation that, with the arm adducted, the range of external rotation alters according to the exact position of the arm in the sagittal plane, we conducted a study to quantify the effect on the range of external rotation of a small increment in forward flexion (15°).

With the arm first in a vertical position and then in 15° of forward flexion, external rotation was measured in 40 asymptomatic and 20 ‘frozen’ shoulders. With forward flexion, the range of external rotation decreased by a mean of 16.9° in the asymptomatic and 13.5° in the ‘frozen’ shoulders.

We postulate that some of the variation is a function of scapular positioning. With arm flexion, the scapula protracts, resulting in alteration in glenoid version. However, some difference is due also to alteration in soft tissue tension in the two arm positions.

The sagittal position of the arm affects the range of external rotation of the adducted shoulder. This variation in measurement may affect the scores of certain outcome measures.

The shape of the glenoid can vary between pear and oval, depending on the presence of a glenoid notch. We measured the glenoid notch angle (the angle between the superior and inferior part of the anterior glenoid rim) in 53 embalmed cadavers and investigated its relationship with the labral attachment to the glenoid at that point.

The attachment of the anterosuperior labrum at the site of the glenoid notch was classified as tight or loose or, in some cases, there was a sublabral foramen. The anterior labrum was then removed and digital images perpendicular to the glenoid notch were taken. Using a digital image analysis program, the angle of the glenoid notch was measured.

In 37 shoulders (70%) the attachment of the labrum at the site of the glenoid notch was assessed as tight and in eight (15%) as loose. In eight shoulders (15%) a sublabral foramen was found. The mean glenoid notch angle was 153° in the loosely attached group, 159° in the sublabral foramen group and 168° in the group with a tight attachment. The presence of a glenoid notch was noted only when the glenoid notch angle was less than 170°.

The glenoid notch angle is related to the attachment of the labrum. In the presence of a glenoid notch, there is more likely to be a loosely attached labrum or sublabral foramen. The loose attachment of the anterosuperior labrum may be a predisposing factor in traumatic anterior instability.

The management of bony lesions associated with glenohumeral instability is the subject of debate. Invariably some time elapses between injury and surgery, during which atrophy may reduce both size and quality of the bone.

The main purpose of our study was to assess the viability of the bone. Histomorphometric bone analyses were prospectively performed on glenoid fragments harvested from 21 male patients during modified Latarjet operations. Their median age was 21 years (16 to 50). Rugby was the main sport of 64% and water sports (surfing, water polo, water skiing) of 21%.

The mean glenoid bone loss on CT scan was 17% (10% to 50%). In 33% of patients, bone loss exceeded 20%. Gross morphology of glenolabral fragments identified a single large fragment in 11 patients, a dominant large fragment with smaller fragments in seven, and multiple fragments in the remaining patients. The mean volume of bony fragments was 2.18 ml (1 to 3) and the mean mass was 1.64 gm (0.43 to 2.8). Histological examination revealed that there was no bone in three of the 21 specimens. Bony necrosis was present in eight of the 18 specimens that contained bone (44%).

Given the histopathological findings, attempts to reattach these devitalised bone fragments by screws or anchors may fail and lead to recurrent instability.

The research question was: can ex-vivo chondrocyte cultures be established in shoulder cartilage biopsies?

Arthroscopic or open biopsies were obtained, with informed consent and institution-approved review protocol, from patients undergoing total shoulder replacement or orthopaedic interventions for end-stage rotator cuff deficiency or arthropathy. Chondrocytes were isolated from eight biopsies and cells cultured over 4-weeks.

In the first week post-digestion, validation studies showed cell counts varying from 30 000 to 400 000 (mean 126 666) and viability ranging from 30% to 100% (mean 75.2%). No primary culture failures were observed. One of the eight had an unexplained lower cell count and viability. Viability exceeded 80% in six of the eight cultures (75%). Alcian Blue stains and flow cytometry (Facscan) confirmed stable cultures with matrix formation. Aggrecan studies are in progress.

The fact that ex-vivo chondrocyte cultures can be established in biopsied shoulder cartilage may prove encouraging for autologous chondrocyte transplant in selected patients meeting stringent inclusion criteria.

The acromion is a bony process that juts out from the lateral end of the scapular spine. It is continuous with the blade and the spinous process. The process is rectangular, and carries a facet for the clavicle. Inferiorly is sited the subacromial bursa. Inferior encroachment or displacement of the acromion can result in impingement.

The aim of this osteological study was to assess the presence of acromial displacement and variations predisposing to compaction of the subacromial space. Using the method described by Morrison and Bigliana, we assessed the scapulae of 128 men and women ranging from 35 to 92 years of age. We found a flat acromion in 30%, no hook in 48%, a small hook in 18% and a large hook in 4%. The presence of a hook was associated with a subacromial facet and a large hook with glenoid erosion.

This study confirms the presence of four types of acromion.

The rotator cuff is sited on the anatomical neck of the humerus and is formed by the insertion of the supraspinatus (SP), infraspinatus (IS), teres minor (TM) and subscapularis. All play a vital role in the movement of the glenohumeral joint, and the anatomy is of critical importance in arthroscopic rotator cuff repair. We undertook an osteological and gross anatomical dissection study of the insertion mechanism of these tendons, in particular the SP .

The SP inserts by a triple or quadruple mechanism. The ‘heel’ (medial) and capsule fuse, inserting into the anatomical neck proximal to the anterior facet of the greater humeral tubercle. The ‘foot arch’ inserts as a strong, flat, fibrous tendon into the facet. This area is cuboidal, rectangular, or ellipsoid, and measures 36 mm² to 64 mm². In about 5%, the insertion is fleshy (pitted), rendering it weaker than a tendinous attachment. The ‘toe’ lips over the edge of the facet laterally and fuses with the periosteum, fibres of the inter-transverse ligament and the IS. A proximal ‘hood’ of about 4 mm stretches down inferiorly and fuses with the periosteum of the humeral shaft. The subacromial or subdeltoid synovial bursa are sited laterally.

The IS and TM insert into the middle and posterior facets (225 mm and 36 mm²) at respective angles of 80° and 115°. The inferior portion of the TM facet is not fused with the shoulder capsule. The subscapularis inserts broadly into the lesser tubercle, and the superior fibres fuse with the shoulder capsule and intertransverse ligament. The insertion of the subscapularis does not contribute directly to the formation of the ‘hood’, which belongs exclusively to the SP, IP and TM.

This study confirms the complexity of the SP insertion and suggests that an unfavourable attachment or biomechanical anatomical malalignment may lead to eventual tendon/cuff degeneration.

The supraspinatus tendon (SP) often ruptures. Gray established that the tendinous insertion always attaches to the highest facet of the greater tubercle of the humerus. Our osteological study of 124 shoulders in men and women between the ages of 35 and 94 years refocuses on the humeral insertion of the SP in relation to infraspinatus (IS) and teres minor (TM).

We found type-I SFs (cubic) in 53 shoulders (43%) and type-II SFs (rectangular or oblong) in 21 (17%). Type-III (ellipsoid) SFs were present in 20 shoulders (16%) and type-IV (angulated or sloping) in 11 (9%). SFs were type V (with tuberosity) in 12 shoulders (10%) and type VI (pitted) in three (2%). The facet area of the SP, IP and TM varied from 49 mm, 225 mm and 36mm2. Of the three muscles, the IS facet was consistently the largest (p < 0.05) and shaped rectangularly.

The SP inserted in a cubic or rectangular facet format in 75% of people. SP facet-size may relate to tendon strength, degeneration and rupture. This information may contribute to the understanding of tears of the rotator cuff.