Therapeutic exercises (eccentric training)
Extracorporeal shock wave therapy (ESWT)
Different injection treatments (platelet-rich plasma, sclerosing polidocanol, steroids, aprotinin, autologous skin-derived tendon-like cells, and bone marrow mononuclear cells)
Surgical treatment of patellar tendon injuries
Open surgical treatment
Longitudinal splitting of the tendon
Excision of abnormal tissue (tendonectomy)
Resection and drilling of the inferior pole of the patella
Closure of the paratenon
Shaving of the dorsal side of the proximal tendon
Removal of the hypertrophic synovitis around the inferior patellar pole with a bipolar cautery system
Arthroscopic tendon debridement with excision of the distal pole of the patella
In acute tears of the substance of the tendon, direct repair should be reinforced with a cerclage wire passing through a patellar osseous tunnel, the distal part of the quadriceps tendon and an osseous tunnel at the level of the tibial tuberosity. When the rupture is located in the osteotendineous junction, the tendon must be re-attached to the bone by means of sutures going from the tendon to the bone via transosseous tunnels. An alternative to the aforementioned bone tunnels is the use of anchors. They provide a solid re-attachment and allow an earlier and more aggressive rehabilitation programme (similar to that employed for treatment of ruptures of the quadriceps tendon) . In acute ruptures, El-Desouky et al. described a technique of primary repair of the patella tendon augmented by a semitendinosus autograft, which was strong enough to permit early motion and weight-bearing with achievement of good and excellent results .
After a primary suture the knee must be initially immobilised in extension. In our practice, the sutures are removed at 2 weeks and at that point an orthosis is provided allowing isometric exercises. Active flexion exercises are prohibited for 4 weeks after surgery. Until the sixth postoperative week, active flexion of the knee must be maintained in a range of 0°–90°. Then, a greater range of knee flexion will be allowed. The aim will be getting a full range of knee motion at 8–10 weeks after the procedure. Finally, the patient will perform isokinetic closed-chain exercises to strengthen the quadriceps muscle and then exercises of eccentric contraction to recover the preinjury level.
In chronic ruptures, a direct repair is usually insufficient . A number of reconstructive procedures have been described using autograft, allograft or synthetic grafts for reinforcement of the primary repair. The Kelikian procedure uses semitendinous tendon, which is sectioned proximally to preserve its distal attachment. Two tunnels are made, one proximally at the level of the lower pole of the patella, and the other one distally at the level of the anterior tibial tuberosity. This way, a square can be formed with the semitendinous tendon that will finally be attached on its own in its distal attachment . Jain et al. modified this procedure by performing a percutaneous reconstruction of the patellar tendon using semitendinosus tendon, reporting excellent results. Picrusting of quadriceps along with lateral release may be required to pull the patella down . Maffulli et al. report results of an open hamstring reconstruction technique at over 5 years’ mean follow-up . They found that hamstring tendon reconstruction of chronic patellar tendon rupture provided good functional recovery and return to preinjury daily activities. Sundararajan et al. modified this technique by using both gracillis and semitendonosus tendons, detached from their tibial insertions and threaded through bone tunnels in a figure of eight, reporting excellent results .
Alternatives to hamstrings reconstruction include other autografts such as vastus lateralis, allograft, xenograft or artificial grafts. However, the evidence base for each are limited. A recent systematic review of the literature suggested that for chronic ruptures, autograft-augmented repair was the treatment of choice .
In contrast to acute ruptures, rehabilitation programme must be more conservative, maintaining the knee immobilised until 6 weeks, going then to the protocol previously outlined for acute ruptures.
6.4 Quadriceps Tendon Injuries
The quadriceps tendon is part of the extensor mechanism of the knee joint together with the quadriceps muscle, medial and lateral retinacular ligaments, patellotibial and patellofemoral ligaments and patellar tendon. All the aforementioned structures are exposed to great mechanical loads, both concentric and eccentric . Quadriceps tendon rupture is uncommon in young people, being more frequent in elderly persons [15, 16, 22].
There are many risk factors associated with quadriceps tendon rupture, most importantly diabetes mellitus, renal dialysis, hyperthyroidism, gout, and in younger people, previous corticosteroids injections. There are also local factors, such as poor vascularisation associated with the normal ageing process [2, 15, 16, 22].
The structure of quadriceps tendon is trilaminar, formed by the expansions of the muscle bellies that form the quadriceps muscle. Quadriceps tendon injury may affect to the full thickness of the tendon or a part of it, starting in the most central area and extending peripherally. Histological analysis of the ruptured tendon usually shows chronic inflammation associated with fibrinoid necrosis and fatty degeneration .
The main clinical finding of a quadriceps tendon rupture is pain associated with a clear functional deficit. Nonetheless, its diagnosis is not always easy, because the integrity of retinacular ligaments may mask the quadriceps tendon injury. Clinical examination will depend on the degree of tendon rupture, sometimes with existing swelling or hemarthrosis making palpation of the tendon difficult. An extension lag of the knee suggests a quadriceps tendon rupture, particularly as the patient tries to extend the knee from the position of knee flexion [15, 16, 22]. Clinical suspicion can be confirmed with complementary studies, such as US and MRI (Fig. 6.1). Plain radiographs may show patella baja in comparison with the contralateral patella (Fig. 6.2). MRI can confirm the injury, mainly its size and depth, and also differentiate a full rupture from a partial one. Tendon rupture will be seen as a lack of continuity of its fibres and the presence of edema or fluid in the adjacent soft tissues . Swamy et al. have suggested that US is not a reliable method in establishing the diagnosis of acute injuries to the extensor mechanism of the knee, particularly for quadriceps tendon ruptures in obese or very muscular patients. If there is clinical ambiguity, MRI scan is a better investigation tool before undertaking surgical treatment .
Tendinopathy of quadriceps tendon (arrow) on MRI
Radiographic view of a quadriceps tendon rupture (arrow)
Treatment will depend on the extent of the rupture. Partial ruptures may be managed conservatively, immobilising the lower limb in extension for 4–6 weeks. At 3–4 weeks, the patient will start isometric exercises. Then, a progressive rehabilitation treatment will be started with the aim of recovering active extension and ultimately full range of movement .