Minimal Access Surgery in Orthopedic Surgery
Conventional (open) methods results in high amount of morbidity. To reduce the morbidity during the secondary injury, i.e. the surgical procedures while opening to reach the site of pathology, encourage the clinician to use the minimal access surgery or endoscopic techniques in orthopedic surgery. Minimal access surgery with endoscope in orthopedic practice useful in the following fields:
• Arthroscopic surgery in sports-related injuries and other pathologies in shoulder, elbow, wrist, hip, knee, foot and ankle
• Arthroscopic assisted surgery in orthopedic trauma
• Spine surgery
• Benign bone tumors.
Arthroscopy is a minimally invasive surgical procedure in which a physical examination of the interior of a joint is performed using an arthroscope, a type of endoscope that is inserted into the joint through a small incision. The advantage of arthroscopy over traditional open procedures is that the joint does not have to be opened up fully and surgery is performed with two small incisions—one for the arthroscope and other for the surgical instruments. This reduces the recovery time for the patient and may increase the rate of surgical success due to lesser trauma to the connective tissue. It is especially useful for professional athletes, who frequently injure joints and require faster healing. There is also less scarring, because of the smaller incisions. In procedures where endoscope or arthroscope is used, the advantage increase manifold by providing magnified view. The advantages of magnification and minimal scarring are extended also to the management of fracture fixation, carpal tunnel release at wrist joint and spinal surgeries. As technology becomes more and more advanced, a greater number of minimally invasive surgical interventions have evolved. With the increase in proficiency of arthroscopic or endoscopic surgery, surgeons are now using the same technique for intramedullary lesion and tumor surgery also.
Clinical effectiveness of MAS procedures over open procedures was proven beyond doubt. Hundreds of controlled randomized trials of procedures using the MAS techniques were published in the 1970s and 1980s. The advantages of minimal access surgery over conventional open surgery are listed in the table below.
In an era of rising health care costs, minimal access surgery offers a significant economic advantage over conventional open surgery. Decreased hospital time, decreased rehabilitation time, and a rapid return to normal activities all add up to a significant ‘savings’ in economic and social costs. Many surgical procedures require a combination of both minimal invasive and open techniques. Therefore, the use of minimal access surgery must be tempered with knowledge of its limitations.
The benefits of MAS in orthopedics
Medical endoscopy for internal organs has begun in the early 1800s by Bozzini. In 1918, Prof Kenji Takagi reported the arthroscopic examination in cadaveric knee at Tokyo University with the a cystoscope. Dr Eugene Bircher was the first to perform and publish the first arthroscopy on live patients, to diagnose tuberculosis. Initially internal examination was done by direct visualization through the eye piece till the advent of fiberoptic light source and camera. On the other hand, the surgical skills in arthroscopy surgery has improved with fine instrumentation. Since then the developments in arthroscopy have become manifold.
As with any other surgical technique, arthroscopic surgery continues to evolve, improvements in fiberoptics, video reproduction and miniaturization, it will enhance and widen its application. During the past two decades, arthroscopic procedures have been replacing traditional, more invasive orthopedic surgical procedures. Today arthroscopy is being done in almost all joints. High performance athletes need a minimal surgical exposure for a faster recovery and quick return to the field with very minimal morbidity. Recently, training simulators (virtual reality) have come into vogue to teach the skills necessary for arthroscopy especially the knee.
Arthroscopic Surgery in Sports Related Injuries and Other Pathology
Knee arthroscopy with the advantage of direct and magnified view inside joint, makes it an excellent diagnostic tool. Its diagnostic accuracy rate of 95 percent has considerable advantages, as compared with the 75 percent accuracy rate of clinical evaluation alone. The high sensitivity of MRI for arthroscopically remediable lesions in cases of internal derangement of the knee indicates that it could be used as a screening test before arthroscopy. Comparison of magnetic resonance imaging and arthroscopy confirmed the higher accuracy of magnetic resonance imaging in the diagnosis of internal derangement but the results for articular cartilage lesions were much less good. Intra-articular fracture, chondral injury, meniscal and ligamentous injuries (partial or complete) can be diagnosed and treated simultaneously.
Anatomic reduction, typically obtained by direct visualization through an arthrotomy and internal fixation (open reduction and internal fixation), is the traditional treatment method for displaced intra-articular condylar fractures of the distal femur and proximal tibia. Arthroscopic assisted reduction and internal fixation, of a displaced, malrotated intra- articular fracture fragment involving the tibia or femur has benefits of decreased blood loss, shortened operative time, excellent intra-articular visualization, decreased soft tissue dissection, and shortened postoperative recovery.
In acute ligamentous injuries, arthroscopy has limited or no role for repair of these ligamentous structures. Once the acute stage subsides, the ligamentous structures can be reinforced or reconstructed. Arthroscopic assisted ligamentous reconstruction is the gold standard treatment for ruptured ligament.
According to recent research, up to 10 to 12 percent of individuals present with chondral injuries. When symptomatic, chondral lesions manifest as swelling and knee pain. The loss of cartilage may be partial or complete, and it may affect one or multiple locations. Nonsurgical treatment modalities include analgesics, knee brace and physiotherapy. Surgical treatment varies from arthroscopic debridement to implantation of autologous chondrocytes beneath a periosteal patch covering the lesion. Autologous chondrocyte transplantation has a durable outcome for as long as 11 years.
Arthroscopic debridement in early osteoarthritic patients may provide early symptomatic relief to pain. The long-term results are comparable with conservative management.
Hip arthroscopy is technically demanding, with a steep learning curve, and requires special distraction tools and operating equipment. Access to the hip joint is difficult because of the resistance to distraction resulting from the large muscular envelope, the strength of the iliofemoral ligament, and the negative intra-articular pressure. This operation should not be done without specific education in its methods. Hip arthroscopy allows thorough visualization of the acetabular labrum, femoral head, and acetabular chondral surfaces as well as of the fovea, ligamentum teres, and adjacent synovium. Microsurgical tools developed specifically for arthroscopic hip surgery can be used to provide the least intrusive means of diagnosis and treatment of conditions involving the above mentioned structures.
Indications for hip arthroscopy
No radiographic study, including high-contrast gadolinium-enhanced arthrography-magnetic resonance imaging, is entirely sensitive or specific for the diagnosis of labral tears or chondral lesions. Thus, a high level of clinical suspicion based on the patient’s symptoms and positive physical findings is paramount for the clinician to recognize subtle abnormalities in the hip joint.
The advantages and experiences of arthroscopy in large joints were extended to the small joints like ankle and wrist. Arthroscopy of the ankle is a relatively new discipline but has in recent years been increasingly applied to the diagnostic and therapeutic treatment of ankle disorders. Indications for arthroscopy in ankle joint are as follow in the table below.
Indications for ankle arthroscopy
Thirty degree wide angles, 2.7 mm arthroscope with a 3.5 mm shaver is used for ankle joint. Ankle joint is also distended, maximum up to 50 mm Hg pressure with the help of pump. To distract the ankle joint ankle strap can also be used for manual traction. Standard portals are anteromedial, medial to the tibialis anterior tendon, and located about 5 mm proximal to the medial malleolus and anterolateral, just lateral to the peroneus tertius tendon. Initial arthroscopy is performed with the scope in the anteromedial portal, but for the majority of the case, this portal will be used for instrumentation. Possible complications with anterior approach are injury to greater saphenous nerve and vein and injury to the dorsal lateral branch of the peroneal nerve.
Recent studies suggest that, with the patient in the prone position, arthroscopic equipment may be introduced into the posterior aspect of the ankle without gross injury to the posterior neurovascular structures.
The shoulder joint is well encapsulated with muscular covering throughout its circumference. Open surgical procedures leads to bleeding and high morbidity, hence minimal access procedures are preferred with the use of arthroscope. Indications for shoulder arthroscopy are enumerated in the table below.
Indications for shoulder arthroscopy
Beach chair position is comfortable for both the patient and the surgeon as it allows free access to shoulder joint and the option of converting to an open procedure. Standard portals for shoulder joint are posterior, anterior and lateral. Complication for shoulder arthroscopy and its position are brachial plexus strain and hypoglossal nerve injury.
Arthroscopic surgery for elbow joint is still in primitive stage and limited to arthroscopic synovectomy. Arthroscopic synovectomy is a reliable procedure to alleviate pain in early grades of rheumatoid arthritis. The fundamental of arthroscopy is visualization and access. Visualization and access to the ulnohumeral and radiocapitellar articulation is rather difficult. Recent study has come out with a joint jack to widen the ulnohumeral joint space to work better posteriorly.
Wrist arthroscopy is the third most common joint after knee and shoulder joint to be examined by arthroscope.
Minimal Access Surgery in Orthopedic Trauma
Opening of the fracture site during exposure further jeopardize the vascularity at the fracture site which adversely effects the healing at the fracture site. The involvement intra-articular fracture needs minimal tissue stripping to further jeopardize the vascularity. This principle leads to the foundation of the minimal access surgical principle in orthopedic trauma surgery. This principle helps to maintain the biology around the fracture site, so this fixation is also known as biological fixation. Biological fixation or minimal access surgery is extremely useful at the site of fractures with comminution, or areas with doubtful vascularity.
Spine Surgery and Arthroscopy
Spinal surgeries are thought to be risky due to the vicinity of the important structures and high vascularity (venous plexus) around the spine. The conventional (open) exposure to reach the site of pathology needs wide exposure which in turns lead to large amount of morbidity and prolongs the period of recovery especially in the thoracic spine surgeries. The advantage of endoscopy like precision, magnification and small incision for exposure has lead to the endoscopic spinal surgery to the great advantage than conventional open procedure.
The endoscope allows the surgeon to use a “keyhole” incision to access the herniated disk. Muscle and tissue are dilated rather than being cut when accessing the disk. This leads to less tissue destruction, less postoperative pain, quicker recovery times, earlier rehabilitation, and avoidance of general anesthesia. Thermal annuloplasty is an adjunctive procedure that uses bipolar electrothermal energy (radiofrequency and/ or laser) to ablate or depopulate the sensitized pain nociceptors in the annulus, ablate any inflammatory/granulation tissue that has grown into the annulus, and to shrink and tighten the stretched or torn collagen fibers of the annulus.
Scoliosis is a three-dimensional problem. The aim of surgery is to try to restore the normal contour of the back from both the front view and the side view. A technique to assist in getting a maximum of correction with a minimum of scar and morbidity by releasing the contacted anterior tissue with the use of the endoscope to go into the chest (similar to the way surgeons take out gallbladders now) in front where the actual vertebra are and take out the disks in front thus relaxing up the spine so we can get better correction and the fusion in back. This method goes in through the chest using three or four small incisions to reach the front of the spine. Once inside the chest the spine is clearly visible and “soft” tissues can be cleaned off exposing the spine. The disks are easily seen and can be removed.
Bone Endoscopy and Tumors
With the increasing experience of seeing inside the soft cavities like joint, the same arthroscope is now used to see inside the bony cavities. The initial results are equal than the open surgical procedure with added advantages of minimal invasive, no immobilization, quick hospital discharge, minimal chances of pathological fracture and very small surgical scar. This is especially useful for benign cystic lesion of bone like giant cell tumor, simple bone cyst or enchondroma. With the endoscopic technique, curettage of the cystic lesion and filling of the cavity by morselized autologous bone or bone cement can be done effectively. This minimal invasive technique allows the lesion to heal at much faster rate and with minimal scaring. This technique is being in practice for the management of these cystic lesion in soft bones or in cancellous bones.