13 Sport and exercise associated problems in adults
Essential facts
1. Correct management of chronic sport injuries requires identification of the underlying cause.
2. When a stress fracture occurs in a young woman, look for features of the female athlete triad (disordered eating, low bone mineral density and menstrual irregularity).
3. Magnetic resonance imaging (MRI) is the investigation of choice for bone stress.
4. Tendinopathy is a degenerative, not an inflammatory, process.
5. Exercise programme that encourage lengthening of muscles during contraction (also known as eccentric training) are the first-line treatment for tendinopathy.
Introduction
Sport and exercise associated problems can be acute, chronic, or acute on chronic. Acute injuries have been covered in the orthopaedic and trauma chapters (see Chapter 12). This chapter will concentrate on chronic overuse problems that occur in the exercising population. A knowledge of anatomy and good clinical examination skills are essential in the accurate diagnosis of these conditions (see Chapter 1).
In addition to diagnosis, an understanding of the reason for the injury is essential for effective treatment. Underlying causes are often multi-factorial and can be intrinsic to the athlete, or extrinsic (e.g. related to equipment, training methods and the environment), as shown in Table 13.1. Different sports are associated with different injury patterns.
Table 13.1 Common associations with overuse injuries
| Reason | Examples | Extrinsic or Intrinsic |
|---|---|---|
| Biomechanical abnormality | Pes planus, over-pronation, leg length discrepancy, muscle imbalance | Intrinsic |
| Technique | Errors or recent changes in technique | Intrinsic |
| Equipment problems | Worn-out running shoes, inappropriate footwear, too large a racquet grip, poor bike setup | Extrinsic |
| Training errors | Sudden changes in the volume, intensity or type of training; excessive training load or inadequate recovery | Extrinsic |
| Surface | Hard, soft or cambered ground | Extrinsic |
Bone stress
Stress fractures occur in normal bone due to repetitive loading below the single-cycle failure threshold. Bone continuously re-models (see Chapter 2) and adapts to the loads applied to it. When the loads are excessive or change too rapidly, there is a continuum from bone stress through to stress fracture. The usual investigations for bone stress are shown in Table 13.2.
Table 13.2 Investigations for bone stress
| Investigation | Comments |
|---|---|
| X-ray | High specificity, low sensitivity. Demonstrates acute fracture lines, non-union, periosteal reactions from 4 to 6 weeks |
| MRI | High specificity and sensitivity. Investigation of choice. Demonstrates bone stress as well as stress fractures |
| Isotope bone scan | High sensitivity, low specificity. If a ‘hot spot’ is identified, regional CT is required |
| CT | Demonstrates bony architecture and anatomy. Useful for following up a positive CT scan and for reviewing fracture healing |
The most common sites are the second to fifth metatarsals, postero-medial tibia, calcaneus and fibula. Some stress fractures are prone to complications (Box 13.1), such as delayed union or non-union, or are at risk of progression. These fractures need a period of extended off-loading, and some require surgical treatment. Figure 13.1 shows a neck of femur stress fracture. These fractures have a risk of completion across the whole neck resulting in avascular necrosis and significant morbidity for the athlete.
