Arthroscopy is a medical procedure used in both the diagnosis and treatment of various injuries or degenerative changes of joints. Arthroscopy is primarily used in orthopedics and trauma surgery. The arthroscope is a variant of the endoscope that is used exclusively in the therapy and diagnosis of pathological joint changes. Decisive for the function of any arthroscope is the basic principle of its construction. Regardless of where the device is used, every arthroscope consists of an optical system of special rod lenses and a small but powerful light source. Furthermore, flushing devices are often integrated into the arthroscope. Using arthroscopy, it was possible for the first time to perform minimally invasive surgical interventions in the joint area. Diagnostic arthroscopy is of particular importance in surgery and orthopedics because, on the one hand, it can be performed as a stand-alone examination and, on the other hand, it can be used directly as part of peri- and preoperative diagnostics (its use is possible during and before surgery). Arthroscopy of the hip joint is to be evaluated as a complex surgical procedure, since the hip joint is comparatively unfavorable anatomically, because it is both narrow and not completely visible during a strong extension (stretching). Because of this, hip arthroscopy was developed relatively late and is not used as frequently for diagnostic and surgical procedures compared to other arthroscopic examinations. In particular, the diagnostic use of the procedure is rare. However, when examining existing synovitis (inflammation of the synovial membrane, which is responsible for the supply of individual joint structures, among other things) or chondromatosis (benign tumor composed of mature bone tissue and thus must be distinguished from a malignant sarcoma), the use of hip arthroscopy is indicated with simultaneous biopsy.
Indications (areas of application)
- Labrum lesion – a labrum lesion is damage to the so-called lip of the socket in the pelvic bone. Partial removal of the lip of the joint is associated with a significant improvement in the symptoms of affected individuals.
- Free joint bodies – the removal of free joint bodies, which are structures that can arise due to joint folds and adhesions in the joint area. The removal of these joint bodies by means of arthroscopy led in various clinical studies to a significant reduction of pain in the affected patient. In part, it is possible with the help of hip arthroscopy to determine the cause of the development of the free joint bodies.
- Cartilage damage – in the presence of cartilage damage, the use of arthroscopy can significantly improve the symptoms of discomfort. The reduction of pain has been shown in various clinical studies. However, it should be noted that long-term results are not yet available, so that it cannot yet be considered certain whether the pain can be permanently reduced. Furthermore, it was not yet possible to identify whether the arthroscopically performed measures on the cartilage of the hip joint or the accompanying therapeutic measures to treat additional pathological phenomena such as by a partial removal of the synovium due to an inflammatory process are responsible for the significant reduction in pain.
- Diseases of the synovial membrane – as already indicated, it is possible to carry out therapeutic treatment in the case of a pathological process in the synovial membrane (inner layer of the joint capsule, the membrana synovialis; synonyms: synovial, synovial membrane). The treatment measure can be performed either as an adjunctive therapy or as an independent therapeutic measure. In particular, the partial removal of the synovium, which can also be called partial synovectomy, is relatively often performed as a surgical intervention.
- Empyema – it is possible to treat an existing hip joint empyema (deep inflammatory process with significant destruction of the affected tissue) using hip joint arthroscopy. For this purpose, lavage (joint irrigation), partial synovectomy and irrigation-suction drainage are used, among others.This indication is relatively rare and few surgeons are familiar with this application of the procedure.
Contraindications
- Fracture of the acetabulum – if a fresh fracture of the acetabulum (anatomical structure of the hip joint) is present, arthroscopy should not be performed, as massive fluid shifts may occur, which in the worst case may lead to cardiac arrest.
- Advanced degenerative changes – arthroscopy of the hip joint can in no way replace the use of a new hip joint. Because of this, particularly advanced signs of wear at the joint should not be treated by means of arthroscopic therapy measures.
- Infection – if there is inflammation in the surgical area, arthroscopy can not be performed under any circumstances.
Before arthroscopy
- Before the diagnostic use of the procedure, which is usually performed under general anesthesia, it must be verified whether the expected examination results make an invasive procedure such as arthroscopy appear reasonable or whether noninvasive procedures such as computed tomography (CT) or magnetic resonance imaging (MRI) allow comparably meaningful results for diagnostics.
- Preoperatively, X-rays in two planes as well as magnetic resonance imaging must be performed. With the help of the use of magnetic resonance imaging with intra-articular contrast medium, also known as arthro-MRI, there is the possibility of increasing the diagnostic significance with regard to the integrity (non-existent damage) of the labrum (cartilage lip of the hip joint) compared to conventional MRI. Furthermore, it should be mentioned that with arthro-MRI it is possible without any problems to apply a local anesthetic (agent for local anesthesia) in addition to the contrast medium (targeted introduction into the tissue). A resulting reduction in discomfort can be interpreted as an additional indication of the presence of a disease process located within the joint structures. From this it can be concluded that hip arthroscopy is indicated in this case.
- Furthermore, it should be checked whether the physical requirements for the performance of a general anesthesia are given.
The surgical procedure
Diagnostic arthroscopy
When performing diagnostic arthroscopy, two methods can be determined based on the different surgical area:
- Diagnostic arthroscopy of the central compartment – in this method, surgical access is performed through the lateral (lateral) and anterolateral (anterior-lateral) portals (operative access). In order to precisely identify the portals, it is necessary to locate palpable bone structures, thereby accurately determining the surgical route. However, it should be noted that the use of only one portal for arthroscopy is not considered sufficient to obtain meaningful results. Instead, it is appropriate to use all created portals alternately for adequate inspection of the hip joint. With the help of these diagnostic tools, it is possible to adequately assess the cartilage ratios of the facies lunata (articular surface of the pelvic socket) and the femoral head, the acetabular fossa (joint cavity in the pelvis), the synovium and the ligamentum capitis femoris (ligament structure of the hip joint).
- Diagnostic arthroscopy of the peripheral compartment – unlike arthroscopy of the central compartment, arthroscopy of the peripheral compartment requires only two portals for the surgical procedure. These portals are the lateral and anterolateral portals. Depending on the requirements, it is possible to use both possible surgical accesses alternately. With the help of this method, the ventral (anterior), medial (middle), lateral (lateral) and dorsal (posterior) parts of the joint can now be inspected, although inspection of the dorsal joint area is considered relatively difficult. Furthermore, this arthroscopic procedure can be used to check the cartilage-covered and cartilage-free femoral head portions. In addition, there is the option to precisely inspect the free edge of the labrum acetabulare (socket covered with cartilage) and as well as the joint capsule in addition to the femoral head portions.
Therapeutic arthroscopy
- Therapeutic arthroscopy of the hip joint is also divided into two groups based on the anatomic structures present, analogous to the division of the diagnostic use of the procedure. Thus, minimally invasive procedure can be distinguished in the central and peripheral compartment.
- So that the optimal access route for the necessary arthroscopic therapy can be selected, so-called X-ray image intensifiers must be used. These amplifiers are an image converter for X-rays to display created X-ray images in real time on a monitor. Only particularly experienced surgeons are usually able to determine the access routes without X-ray image intensifiers exclusively under arthroscopic visual control.
After surgery
However, usually postoperatively (after surgery), the joint is rested for several weeks. Furthermore, a control examination is carried out within the first week after the operation has been performed.
Possible complications
- Nerve lesions – in arthroscopy of the hip joint, which has few complications for an invasive procedure, nerve lesions are the most common complications. In particular, the pudendal nerve, sciatic nerve, and femoral nerve are often affected as they pass through the surgical site. However, the vast majority of nerve damage is temporary loss of nerve function, and complete function of the affected nerve usually returns within a few weeks.
- Soft tissue injuries – the invasive procedure may cause injuries to the external genital and trochanteric regions. Of less clinical relevance is swelling, which occurs in one in five arthroscopic procedures on the hip joint. Due to the occurrence of clinically relevant swelling of the soft tissues, which is caused by the washing of irrigation fluid into the tissue, the instrument handling of the soft tissues can be significantly complicated due to the increase in volume.
- Infection – in the course of arthroscopy, the development of an inflammatory process is possible, but relatively rare. The risk of infection is present even with near-optimal hospital hygiene. The risk of infection is additionally dependent on the duration of lying before the performance of arthroscopy.
