Bullet wounds affecting the hip joint are relatively rare injuries, accounting for 2% − 17% of all civilian gunshot wounds (1, 7, 8). The final resting place of the missile can be free-floating within the joint, located peri-articularly or lodged within the bone of the femur head, neck or acetabulum.
Retained intra-articular bullets are removed for a variety of reasons, mainly to prevent infection, 3rd body wear, lead arthropathy and rarely, systemic lead poisoning (9).
The literature on bullet removal from the hip joint is sparse, with mostly small case series and sporadic case reports. Twenty-five publications appear in the English literature regarding removal of retained hip bullets, with a total of number of 48 bullets removed over a 47-year period. We report on the largest series with 46 hip bullets removed at a single institution over a 13-year period, using open surgical techniques (Table 1).
Table 1
| Removal technique | Number of cases |
| Hip Arthrotomy | 19 |
| Surgical hip dislocation | 18 |
| Tractotomy | 5 |
| Direct removal at site of fracture fixation/replacement | 3 |
| Posterior wall osteotomy | 1 |
Hip arthroscopy is the most commonly used modality to remove retained bullets in the hip.
Goldman was the first to report its use to remove a bullet from the hip joint though this was combined with a limited open approach for insertion of the posterior portal (10).
Hip arthroscopy offers the advantages of minimally invasive surgery with quicker recovery and reduced hospitalization days. It can be performed in lateral or decubitus positions, using traditional anterior portals or inferomedial or posterior portals. Hip arthroscopy can be performed in isolation or with ‘tractoscopy’ or combined with limited open techniques (11). It also offers opportunity for treatment of concomitant lesions such as debridement of chondral flaps, chondroplasty and microfractures.
It however has a steep learning curve, requires additional specialized equipment like C-arms for screening, and is not readily available in most institutions. Grasping the bullet may also prove challenging and there are reports of fluid extravasation leading to cardiac arrest (12, 13). Despite limitations, removal of bullets has been one the most common indications for hip arthroscopy in the trauma setting (2, 3, 11, 14–26).
In all our cases we were able to remove the bullets utilizing open surgical techniques.
Sometimes the final resting place of the soft missile may be embedded in hard bone which can lead to iatrogenic joint damage during attempts at removal(27). To ensure complete inspection of the femoral head and acetabulum, and to aid safe removal of retained missiles, Maqungo et al performed surgical hip dislocation (SHD) to remove retained missiles and they reported a 100% success rate (28). SHD also allowed for treatment of associated chondral lesions with debridement and microfracture techniques. SHD is a safe procedure first described by Ganz for treatment of femoro-acetabular impingement (29). In this series we successfully used SHD with a trochanteric step osteotomy to remove 18 bullets (Fig. 3).
Other open techniques like posterior wall osteotomy and open arthrotomy have also been reported (8, 30).
Krishnan et al used an extra-articular approach without dislocating the hip to remove a bullet that was lodged into acetabulum posterior column, with only the tip protruding into the hip joint (31). The bullet was removed by creating a window in the posterior column, guided by a K-wire placed under fluoroscopic guidance.
Williams used a DHS triple reamer to remove a bullet that was lodged in the femoral head (20).
We used open arthrotomy via anterior Smith-Petersen (n = 12) or posterior approaches (n = 7) in a total of 19 patients.
In one case, the bullet had been observed to be lodged anteriorly inside the hip joint capsule. The patient was booked for insertion of a sliding hip screw plus removal of bullet. However, during attempts at removal using the Smith-Petersen approach, the bullet was noted to have migrated and was by then lodged posteriorly. The anterior approach was abandoned and a posterior arthrotomy was performed two days later and the bullet successfully removed (Fig. 5).
A tractotomy was utilized in cases where the bullet was resting in bone and in direct communication with the hip joint. This entails following the bullet tract without the need to perform an arthrotomy. The hip joint is then washed through the bullet tract. In two patients this was achieved via a modified Stoppa approach (anterior intrapelvic approach) to retrieve bullets that were lodged medially in the quadrilateral plate of the hip joint (Fig. 4). This approach has been described for a similar indication previously (32).
Three patients had direct bullet removal from the fracture site at the time of surgical fixation (n = 2) or total hip arthroplasty (n = 1). Total hip arthroplasty has been described for post-traumatic arthritis secondary to gunshot injuries (33–37). Ours is a rare case of primary total hip arthroplasty in a 31-year-old male performed in the acute setting following a gunshot injury (Fig. 6). This was due to the extensive comminution of the femoral head and neck as well a very vertical fracture line which would increase the likelihood of fixation failure as these cases have a poor prognosis with fixation and have been described as ‘doomed to failure’ (38). We have been following this case up for 2 years and he continues to do well with excellent function and no signs if infection.
Table 2 summarizes the cases where the bullets were not removed. In 17 cases the final resting place of the bullet was extracapsular even though the bullet had traversed the hip joint capsule en route to its final resting position. In these instances, it is expected that the soft tissues will close and seal the missile from contact with the hip joint. Projectiles located in soft tissues are sealed off by non-vascular scar tissue which reduces the chances of infection or lead poisoning (9).
Table 2
Reason for bullets not removed.
| Reason for not removal | Number of cases |
| Final location extracapsular | 17 |
| Clinical decision not to remove (patient unwell) | 8 |
| Patient refusal | 1 |
In 8 cases a clinical decision was made to not remove the bullets due patients’ clinical condition not allowing further surgery and 7 of these patients subsequently demised. In one of these cases the final location of the bullet was being deeply imbedded in the femoral neck and a decision was made to not remove it (Fig. 7). This is a clinical stance supported by Howse et al as well as Christie et al (11, 39).
One patient refused bullet removal and was discharged without further follow-up.
In all the cases in this series, as well as in the quoted studies, the bullets were removed early in the clinical course because missed injuries and late retrievals have been shown to have poor outcomes with increased risk of septic arthritis (8, 40). Our average time to removal was 6 days (range 1–12).
Limitations
The relatively low numbers represent a limitation of our study. This is however the largest series to date published from a single institution.
Long-term clinical outcomes are beyond the scope of this manuscript as our endpoint was successful removal of bullets utilizing proven surgical techniques with known long-term outcomes.
The epidemiology of associated injuries is also beyond the scope of this manuscript.