Hip being a deep joint surrounded by heavy muscles all around, the open access to the joint is a major procedure requiring more dissection, more blood loss and delayed post operative rehabilitation. A danger of damage to the blood supply of the femoral head is an additional serious risk factor especially with the posterior approach. Although in the absence of the dedicated hip arthroscopy instrumentation with long handles, the chances of failure of the procedure are high, making an attempt with the existing technology is worthwhile to reduce the morbidity of the open procedure.
During the procedure, the distraction of the hip joint required more traction than we normally used in hip arthroscopy. This may be due to the formation of scar tissue around the projectile resulting from a delay of four months. However, the patient being of a thin built with less muscles, we were able to overcome this, although it resulted in temporary neuropraxia in the perineal region due to pressure of the perineal post.
We used a thin long curved osteotome for disimpacting the projectile from the acetabulum. Before introducing the osteotome, we had already unsuccessfully tried moving the bullet with a probe and a blunt arthroscopic trocar repeatedly. Before abandoning the procedure and changing over to open arthrotomy, the attempt of using the osteotome proved fertile. However, we were very cautious during the introduction of the osteotome and used fluoroscopic navigation to avoid slipping of the osteotome. After the disimpaction, we used a probe hook to manipulate the disimpacted bullet towards the convenient location in the joint where the grasper could be easily introduced. The thin built of the patient further facilitated the reach of our instruments into the hip joint.
The compelling reason of surgical extraction of an intraarticular bullet in the present case was excruciating pain suffered by the patient and his inability to lead a normal life. The location of the bullet in the hip joint resulting in catching of the bullet in certain positions of the thigh had made the patient's life miserable. Even otherwise, the extraction of the bullet from the hip joint has been indicated to avoid the long term risk of mechanical arthritis, and systemic lead toxicity caused due to dissolution and absorption of the lead through the synovial fluid.4,8–10
The risk of being a potential nidus of infection, although mentioned in literature,4,11
was probably negligible in our case at four months post-injury.
We have not used a pre-operative CT scan in the present case. However, the two standard antero-posterior and lateral views of the preoperative X rays and the visualization of the joint through a complete arch of rotation of C arm, per operatively, helped us to rule out the other intraarticular pathologies even in the medial articular space where the arthroscopic visualization is difficult.3
Although we agree that the availability of the facility of CT scan pre-operatively is an additional advantage, for more accurate planning and better pre-operative documentation, absence of the facility should not be a limiting factor for undertaking the surgery.
With successful arthroscopic retrieval, we could avoid several disadvantages of an open procedure including significantly diminished blood loss, cosmetic incisions, decreased risk of osteonecrosis of the femoral head and shortened recovery time.6,7
All the potential complications of the hip arthroscopy were discussed with the patient before undertaking the procedure. There is a report of cardiac arrest resulting from extravasation of the irrigation fluid through the fracture line into the abdomen during the arthroscopic removal of a loose body from the hip joint of a patient with an acetabular fracture.12
A theoretic risk of developing the same complication by introduction of the fluid through the bullet tract has also been expressed.4
In the present case, however, having no fracture line, and being undertaken at a delay of four months, resulting in complete healing of the bullet tract, this risk was negligible. Other risks to be kept in mind include perineal numbness/necrosis related to the traction post, radiation exposure and injury to the femoral neurovascular bundle anteriorly and sciatic nerve posteriorly.
We feel that a small residual crater in the weight-bearing area of the acetabulum left after the extraction of the bullet, in the present case, is unlikely to cause immediate problem because the large sized spherical femoral head will be able to walk over it without catching. However, the long term possibility of a secondary osteoarthritis is a risk to be kept in the mind and we have advised the patient to be on regular follow-up at least once in six months. In conclusion, we feel that it is worthwhile to attempt for arthroscopic retrieval of foreign bodies from the hip joint even in the absence of specialized equipment. This reduces the morbidity of the patient.