The results of hip arthroscopy clearly depend on the condition being treated. Some patients do well, some not so well. A major problem, of course, is that sometimes one simply does not know what the condition is until hip arthroscopy has been performed. In addition, hip conditions rarely occur in isolation. It would be quite normal, for example, for a patient to present with a combination of femoroacetabular impingement, a loose body and some osteoarthritis. Consequently, to predict ahead of time how a patient will do after surgery can only ever be a professional estimate. However, in outline, the results may be summarised as follows:

• Diagnostic hip arthroscopy
  There is an almost 100% chance that a diagnosis may be given to a patient after a diagnostic hip arthroscopy. However, although a surgeon may find something that looks abnormal within the hip joint it is sometimes difficult to say whether the abnormality is the cause of a patient’s pain.
• Femoroacetabular impingement (FAI)
  Results for FAI surgery have improved in recent years. Now, approximately 80% of patients will show an improvement in their symptoms at the one-year review point after surgery, 15% will be the same and 5% will be worse.
• Osteoarthritis (OA)
  OA is not a classic indication for hip arthroscopic surgery but it may still sometimes be recommended. If so, the chances of success are approximately 40% at one year, with 45% of patients being the same and 15% being worse.
• Ligamentum teres tears
  These do surprisingly well, for reasons which are unclear. However, more than 90% of patients with tears of the ligamentum teres do well after debridement (surgical cleaning), or shrinkage of the partially torn ligamentum. The results for ligamentum teres reconstruction are still unavailable as this is such a new area for hip arthroscopic surgery.
• Infection
  Fortunately, infections of the hip joint are rare. However, should they occur then hip arthroscopy is one good way of identifying the organism involved and thoroughly cleaning the hip joint. Because of the huge diversity of bacteria which can cause infections, some of which are quite virulent and some of which are not, it is difficult to give a precise figure for success rates.
• Synovitis
  This term implies an inflammation of the lining of the hip joint (synovium). Hip arthroscopy is a good way of identifying a synovitis and removing (synovectomy) the inflamed area. However, the procedure cannot reverse any damage caused by the synovitis so results are difficult to predict as they will depend on how much damage has been caused before the hip arthroscopy is undertaken.
• Loose bodies
  If loose bodies are identified early in their development then the success rate of surgery is good, well over 80% at one year. However, the longer a loose body stays in place, the higher the chance of damage occurring, so that it may eventually become difficult to undo the damage which has been caused. It is quite common for loose bodies to recur after surgery, so it is sometimes necessary for a surgeon to undertake a further hip arthroscopic procedure at a later date to remove the recurrent loose bodies.
• Painful joint replacement
  Although the purpose of performing a hip arthroscopy of a painful joint replacement is to see what is causing a patient’s pain, it seems that about 40% of patients can be improved by arthroscopic surgery anyway. In about 90% of patients with a painful joint replacement, but for whom the reason for the pain is unclear, a reason can be given for their pain after hip arthroscopy. This is useful when planning future treatment.
• Trochanteric bursitis
  Trochanteric bursitis describes a condition of pain over the outer (lateral) aspect of the hip joint, although it is now realised that pain in this area can be caused by many different problems. The area is easily accessible to the hip arthroscopist, although the results of surgery are not as good as they might be for certain other hip conditions. Approximately 70% of patients can be improved by hip arthroscopic surgery to these lateral hip structures.
  

• Torn acetabular labrum
  This is a common condition which may occur in isolation or which may be associated with femoroacetabular impingement. When treated in isolation, approximately 67% of patients are improved by hip arthroscopic surgery. The result at one year after surgery seems still to persist at four years.
• Iliopsoas tendonitis
  On the front of the hip lies a large, powerful muscle called iliopsoas, which is responsible for bending (flexion) of the hip joint. This can sometimes become inflamed or even tear. When inflamed it is possible to decompress the tendon from the sheath in which it runs and settle pain in approximately 80% of patients. Much rehabilitation is required after the procedure, however.
• Tumours
  Rarely found in the hip joint and even more rarely treated arthroscopically, occasionally arthroscopic surgery is required. Perhaps the commonest tumour seen by the arthroscopist in the hip joint is the lipoma, a totally benign, smooth mass of fatty tissue. This can easily be removed through the arthroscope and can result in symptomatic improvement in more than 90% of patients.
• Rheumatoid arthritis
  This is now frequently treated medically. However, on occasion hip arthroscopy is needed. In the early stages arthroscopy allows the synovium to be removed as a synovitis is commonly seen in rheumatoid arthritis. One can expect more than 80% of patients to show good symptomatic improvement from this. However, if the rheumatoid arthritis progresses and gristle destruction occurs, so it is harder for hip arthroscopy to make a significant difference and successful results may then only be expected in fewer than 20% of patients.
• Avascular necrosis
  This term describes a situation where there is a reduced blood flow to an area of the ball of the hip joint (femoral head). Hip arthroscopy is useful at identifying the early signs of progression of this condition and also allows treatment by either simple cleaning of the damaged area, or drillings, or bone grafting. Results are variable as it is not always possible to rescue a hip joint from the effects of avascular necrosis. There is also a small chance that hip arthroscopy can make the condition progress rather than salvage the situation.
• Trauma
  Sometimes, after an injury to the hip joint, hip arthroscopy is needed. Perhaps the commonest occasion is after a dislocation of the joint, particularly if loose fragments of bone are lying free within the hip. Hip arthroscopy is a good way of retrieving them. However, hip arthroscopy is best seen as a method of assessment after hip injury than as a final method of treatment as the end-result depends so much on the magnitude and nature of the original injury.
• Quality of life
  Recent research suggests that there is a significant improvement in quality of life after hip arthroscopic surgery generally. The level of improvement reached is higher than that achieved after total hip replacement but the amount of improvement, when comparing pre- and post-operative states, is less.
• Making matters worse
  Much as one might wish otherwise, not all hip arthroscopic procedures will make patients better. Some 5% can be made worse by hip arthroscopy.