Ultrasound imaging in musculoskeletal injuries-What the Orthopaedic surgeon needs to know

Abstract

Patients with musculoskeletal complaints have either been ignored or advised investigations far beyond their means or comfort. Focusing attention only on spine and head restricted the evaluation in cases of trauma and were followed up only if the injuries were life threatening. In the same vein, the extremities often got overlooked or at best were evaluated only by plain radiographs. Soft tissue injuries were therefore often missed and not only raised the morbidity in the patient but also dissatisfaction towards the treating physician. Recent exponential improvement in medical ultrasound technology has revolutionised the field of musculoskeletal imaging. Cutting-edge technology using state-of-the-art machines and high-frequency transducers have placed it in a stronger position as compared to in the past in many aspects of musculoskeletal imaging. Also, with better techniques and understanding of the modality, under given set of circumstances MSK ultrasound has far reaching results allowing for detailed evaluation of soft tissues including nerves, ligaments and tendons.

Keywords: Bones and joints; Injury; Ligaments; Muscles; Musculoskeletal; Nerves; Paediatric; Scope; Sports; Tendons; Trauma; Ultrasound.

Fig. 1

Extended field of view showing Full thickness Rotator-cuff tear involving tendon of Suprapinatous with retraction from the insertion foot print of Greater tuberosity (GT). Thickened Subacromial sub-deltoid bursa is seen.

Fig. 2

Soft putty like echogenic Calcification noted in the Supraspinatus tendon with minimal distal shadowing. Underlying bony acoustic margin of Greater tuberosity is showing subtle irregularity but no cortical erosion. Maintained overlying Subacromial subdeltoid bursa noted with absence of effusion.

Fig. 3

Ultrasound guided intra-articular injection at sternoclavicular joint with echogenic needle shaft in position showing reverberation artefacts. Tip of the needle is well visualized within the hypoechoic synovial proliferation.

Fig. 4

Peripheral nerve sheath tumour (PSNT) involving the Ulnar nerve. Proximal segment of the nerve fibres with typical cable like appearance are well preserved and are noted within the eccentrically positioned tumour.

Fig. 5

Olecranon bursitis with thick walls and internal relatively iso to hyperechoic synovial proliferation. Overlying Subcutaneous tissues are thickened. Underlying bony acoustic margins of olecranon process are normal. Partially seen superficial fibres of tendon of triceps show normal echoreflectivity at the insertion.

Fig. 6

Knee effusion with distended suprapatellar recess showing echofree contents. No evidence of synovial proliferation noted. Acoustic margins of distal femoral shaft is showing smooth margins with absence of destruction at the level of implant host site in a post-arthroplasty patient (TKR- Total knee replacement).

Fig. 7

Active synovitis (Rheumatoid arthritis) in the proximal inter-phalangeal joint. On colour Doppler imaging, intense vascularity is raised in the synovium. No cortical erosions of underlying phalanges noted. (GSU score 2/PDU score 3) (PP- Proximal phalanx, MP- Middle phalanx).

Fig. 8

a.– Fracture lateral end of clavicle, persistent pain 2 weeks after a fall and Negative radiograph. Step off discontinuity noted at the lateral third shaft clavicle (f). Acromio-clavicular joint is well preserved. (CL- Clavicle, AC- Acromion, ACJ- Acromioclavicular joint) 8 b- Linear echogenic foreign body (F.B) in forearm subcutaneous tissues – wooden splinter. No distal acoustic shadowing or reverberation artefacts of metallic F.B.

Fig. 9

Olecranon complex bursitis grey scale imaging assisted with Colour doppler. Vascularity noted in the surrounding thick wall of the superficial bursa with normal smooth acoustic margins of the olecranon process. Internal contents show fine septations of haemorrhagic fluid (1. Wall thickness of the bursa).

Fig. 10

Entrapment Neuropathy – Cubital tunnel syndrome (Ulnar nerve). Enlarged ulnar nerve with typical honey-coomb pattern noted in short axis scan. Thick Osborne's ligament noted forming the roof of cubital tunnel. (OL- Olecranon process, MED- Medial epicondyle, CUBITAL – Tunnel, 1. Ulnar nerve).

Fig. 11

a. Normal Median nerve long axis scan at wrist joint with ‘Rising lunate sign’ as the level of Flexor retinaculum. No evidence of entrapment noted and the median nerve is showing comparable thickness in the entire extent. (RA – radius, LU- Lunate, MN- Median Nerve, FDS – Flexor Digitorum Superficialis, FDP- Flexor digitorum Profundus) 11 b. Median Nerve entrapment with Ultrasound signs of Neuropathy changes – Carpal tunnel syndrome. Enlarged oedematous proximal segment of Median nerve. distal to the flexor retinaculum the nerve shows normal thickness. Convex Bony echogenic margin of lunate noted in deeper planes marking the site of overlying retinaculum.

Fig. 12

Hip effusion in a paediatric patient 2 yrs. Relatively echogenic synovial proliferation noted. Capsule is showing thickening. (FL- Fluid, M- Metaphysis, E -Ossific Epiphysis, C- Capsule, Black E- Unossified cartilaginous epiphysis).

Fig. 13

Knee effusion with synovitis (SY) long axis scan. Grey scale imaging assisted with PDU imaging showing minimal vascularity in synovium. Tendon of quadriceps is showing normal tri-lamellar pattern. Bony margins of superior pole of patella and distal femoral shaft anterior margin are normal. (QT- Quadriceps tendon, EFF- Effusion, P- Patella).

Fig. 14

Bakers cyst with internal echoes of minimal synovial proliferation noted extending in between the tendon of Semimembranosus and Medial Gastrocnemius. Neck is well demonstrated to differentiate it from other cystic swellings. (SY- Synovial proliferation, MGM- Medial Gastrocnemius, SM- Semimembranosus, CY- Cyst).

Fig. 15

a.: Achilles tendon with a partial thickness tear. Superficial fibres of the tendon are intact. (CAL- Calcaneum). 15 b.: Achilles tendon with complete tear- Clapper bell sign. Fluid noted in between the torn retracted segments.

Fig. 16

Ultrasound demonstrating normal anterior talofibular ligament (ATFL) (a). (b) Complete tear. The ATFL are injured when a plantar-flexed foot is forcefully inverted. (F- Fibula, Arrows- normal ATFL).

Fig. 17

a. The defect in the fascia of Tibialis Anterior with muscle bulging through is pathognomonic of a muscle hernia. 17b. Morel Lavallee Injury- Degloving injury arm showing subcutaneous haemorrhagic collection (H) with underlying triceps belly (TR). HU- humeral shaft.