Patellar tendon tear

Definition[edit | edit source]

Patella Tendon tear is an extremely disabling injury resulting in an inability to extend the knee.[1] The tear can be partial, with only some fibers torn, or complete tear of the tendon that runs from the patella's inferior pole to the tibial tubercle.[2]It is common in men who are in their 30's and 40's[1][2]

Clinically Relevant Anatomy[edit | edit source]

The patella tendon, is a ligament as it connects bone (patella) to bone (tibial tubercle). It is approximately 30 mm wide by 50 mm long, with a thickness of 5 to 7 mm. The origin on the inferior pole of the patella is juxtaposed on the articular cartilage on the deep side and becomes confluent with the periosteum of the patella anteriorly. The tibial insertion is narrower and invests the entirety of the tibial tubercle, connecting the quadriceps muscles to the lower leg.[2]

[3]

Etiology[edit | edit source]

Patella tendon tear can be caused by an underlying weakened tendon. Inflammatory conditions; tendonitis and some certain medical conditions;[4] Systemic lupus erythematosus, Rheumatoid arthritis,Chronic renal disease, Diabetes mellitus can lead to weakened patella that can predispose an individual to tendon tear.[2]

Other factors such as mechanical stress , trauma (direct or indirect)[5], prolonged use of corticosteroids , previous surgery around the knee joint, obesity[6] can predispose an individual to patella tendon tear.

Characteristics/Clinical Presentation[edit | edit source]

  • Individuals with patella tendon tear presents with the following;
  • Infra patella knee pain[2]
  • Swelling
  • Difficulty with weight-bearing
  • Difficulty straightening the leg.
  • They may report an audible “pop” or the sensation of their knee giving way during an event with a sudden quadriceps contraction with the knee in a flexed position[2]
  • An indentation at the bottom of your kneecap where the tendon tore.[7]
  • When a tear is caused by a medical condition, like tendonitis, the tendon usually tears in the middle.

Differential Diagnosis[edit | edit source]

  • Quadriceps tendon rupture
  • Patella fracture
  • Tibial tubercle avulsion fracture

Diagnosis[edit | edit source]

Diagnosis of patella tendon tear should be made as early as possible to avoid poor functional outcome with a loss of full knee flexion and decreased quadriceps strength.[8]Accurate diagnosis depends on detailed history, physical examination and radiographic examinations.[2][8]. The history should include the onset of their symptoms, specific location the pain, duration of the pain and symptoms, characteristics of the pain, alleviating and aggravating factors, any radiation of pain, and the severity of symptoms.

Physical examination should begin with inspection; inspect patella height and compare the affected and unaffected sides. A patella tendon rupture will likely be associated with an elevation of the patellar height compared to the uninjured side. followed by palpation of the knee and surrounding structures for signs of trauma, tenderness and swelling. Patella tendon tear often will be associated with a large hemarthrosis and surrounding ecchymosis.[2]There is always a palpable defect below the inferior pole of the patellaand localized tenderness about the infrapatellar aspect of the knee.

Range of motion (ROM) testing and muscle strength testing are essential aspects of the knee exam, decreased ROM of the knee due to pain and disruption of the extensor mechanism is an indication. There will be a loss of active knee extension, which is the key physical exam finding.[2]

Radiographic examination may reveal patella alta. An MRI of the knee is an appropriate diagnostic study if a patella tendon tear is suspected. It is the most sensitive imaging modality and can differentiate partial from complete tendon rupture. Ultrasound also may be used.[2][8]

Management[edit | edit source]

The goals are to make an early diagnosis and surgically repair the injured tendon.[5]Surgical management, non surgical management and postoperative rehabilitation are required to ensure satisfactory outcomes.[9]and should not be delayed whenever local and general conditions permit

Surgical Management[edit | edit source]

Surgery remains the best treatment and should not be delayed whenever local and general conditions permit [7]. An early repair, within 2 to 6 weeks, may prevent the tendon from scarring and tightening in a shortened position. In delayed diagnoses, more than 6 weeks after the rupture, quadriceps contracture and fibrous adhesions make the surgical repair and restoration of the patella tendon length more complicated. Surgical repair is necessary to reestablish optimal extensor function.

Physical Therapy Management [edit | edit source]

Physical therapy management can be sub divided into: Non surgical treatment and postoperative rehabilitation

Non surgical management is employed in partial patella tendon tear with an intact knee extensor mechanism and it involves immobilization in a cylindrical cast in extension for 6 week with a progressive weight bearing exercises.[7] [2] Exercises to strengthen the quadriceps muscles can be done. In addition straight leg raises can be executed. Postoperative rehabilitation of a patella tendon tear

The following guideline by vitale et al[10]is recomended

First 2 weeks after surgery, weight-bearing should be encouraged as tolerated with crutches and knee brace locked in full extension ROM can be incorporated based on the quality of repair

Week 2 to 6; weight bearing as tolerated with crutches and knee brace locked in full extension. Passive ROM from 0 to 90 degrees of knee flexion, no active quadriceps extension

Week 6 to 12; normalize gait on a flat surface, wean crutches, the knee brace may be opened to allow flexion, begin active quadriceps contraction and gradual progression of weight bearing with knee flexion, avoid weight-bearing in knee flexed past 70 degrees .Active ROM of knee,progressive light squat, leg press, core strengthening, and other physical therapy exercises and modalities

Week 12 to 16 ; normalize gait on all surfaces without a brace, full ROM, single-leg stance with good control, and squat to 70 degrees of flexion with good control, non-impact balance and proprioceptive drill, quad, and core strengthening

Week 16 and beyond ; good quad control, no pain with sport or work specific movement, including impact activity

Resources[edit | edit source]

References[edit | edit source]

  1. 1.0 1.1 Gilmore JH, Clayton-Smith ZJ, Aguilar M, Pneumaticos SG, Giannoudis PV. Reconstruction techniques and clinical results of patellar tendon ruptures: Evidence today. The Knee. 2015 Jun 1;22(3):148-55.
  2. 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 Hsu H, Siwiec RM. Patellar tendon rupture. InStatPearls [Internet] 2021 Jul 25. StatPearls Publishing.
  3. nabil ebraheim. Anatomy Of The Patellar Tendon - Everything You Need To Know - Dr. Nabil Ebraheim. Available from: http://www.youtube.com/watch?v=H9QXILgB9Mw [last accessed 23/12/2022]
  4. McGrory JE. Disruption of the extensor mechanism of the knee. The Journal of emergency medicine. 2003 Feb 1;24(2):163-8.
  5. 5.0 5.1 Bhargava SP, Hynes MC, Dowell JK. Traumatic patella tendon rupture: early mobilisation following surgical repair. Injury. 2004 Jan 1;35(1):76-9.
  6. Macchi M, Spezia M, Elli S, Schiaffini G, Chisari E. Obesity increases the risk of tendinopathy, tendon tear and rupture, and postoperative complications: a systematic review of clinical studies. Clinical orthopaedics and related research. 2020 Aug;478(8):1839.
  7. 7.0 7.1 7.2 Ilahiane M, Abdulrazak S, Hassani I, Marzouki A, Boutayeb F. Acute Patella Tendon Rupture A Case Report. Orthopedics and Rheumatology Open Access Journals. 2018;13(2):35-8.
  8. 8.0 8.1 8.2 Fazal MA, Moonot P, Haddad F. Radiographic features of acute patellar tendon rupture. Orthopaedic Surgery. 2015 Nov;7(4):338-42.
  9. Murphy S, McAleese T, Elghobashy O, Walsh J. 222 Bilateral Patellar Tendon Rupture Following Low-Energy Trauma in a Young Patient Without Predisposing Risk Factors. British Journal of Surgery. 2022 Sep;109(Supplement_6):znac269-123.
  10. Vitale JA, Banfi G, Belli E, Negrini F, La Torre A. A 9-months multidisciplinary rehabilitation protocol based on early post-operative mobilization following. European Journal of Physical and Rehabilitation Medicine. 2018 Dec 14.