To our knowledge there is a paucity of analogous studies have been done on hip..Although the classification, treatment, and complications of hip fractures in blunt trauma are well known, there is limited information on gunshot and sharapnel injuries. An anatomic reduction of the fracture may not be possible in these cases as a result of significant bone and/or cartilage loss. In these cases, primary stabilization of the fracture site is attempted rather than an anatomic reconstruction of the joint to prevent further complications such as secondary displacement or pseudarthrosis.
Firstly an anteroposterior radiograph of the pelvis is needed to analyze bone and joint involvement, and pelvic instability [7]. Gunshot and shell fragment wounds to the pelvis require special attention because of the vital anatomy within the pelvis. Bladder, urinary tract and bowel injuries must be aggressively investigated. At the time of presentation, injury to vital structures may lead to associated morbidity and mortality, hence these patients should be treated in a multispecialty center [7]. After a treatment plan has been made for life-threatening conditions, a detailed orthopaedic evaluation is essential. The most of the combat injuries are penetrative, and most are caused by fragments from explosive munitions rather than by bullets fired by military arms [8]. In shrapnel injuries there may be multiple small fragments varying in size and can be easily overlooked. Twelve patients evaluated in the current study were injured with shell fragment.
In the acute period, arthrodesis or arthroplasty is not recommended. After hip joint injury, open reduction and internal fixation are advised for fracture treatment [1]. Arthroplasty should be done under elective conditions because of the risk of infection. In the present study, hip arthroplasty was performed in the chronic period after hip joint gunshot and shell fragment injuries as in previous studies [5, 9, 10]. In patients with posttraumatic arthritis occured after gunshot wounds, surgery is more difficult than primary total hip arthroplasty [9]. For transabdominal gunshot injuries including the hip joint, algorithms were reported suggesting immediate irrigation and debridement with antibiotic treatment [11]. In a study patients treated with arthroplasty following a gunshot injury to the hip joint, those with contaminated with intestinal flora had worst harris hip score. Very high infection rates were seen in patients with accompanying intestinal injury [5]. In the current study there was only one patient with intestinal injury and infection was not occured after arthroplasty.
Most low-velocity gunshot wounds without fractures may be securely treated nonoperatively with or without antibiotics [12]. Contaminated high-velocity gunshot injuries are indications for surgical debridement and administration of prophylactic antibiotics [12]. At our institution, the first step was always wound irrigation and debridement to minimize the risk of infection. In the current study all patients with gunshot wounds were high-velocity injuries. Triple prophylactic antibiotics were administered routinely for all gunshot and shell fragment injuries. If it was possible retained fragment was removed. In our study in 22 cases surgical debridement was performed once while the other 4 patients needed multiple debridments.
There are reports of arthroscopic removal of fragments from the joints [13, 14]. The minimally invasive approach may decrease the morbidity associated with muscle and soft tissue dissection however, marginally increased operative times and the possibility of compartment syndrome resulting from leakage of irrigation fluid, through capsular and fascial defects into the muscular compartments. Authors have no experience with this technique.
Removal of foreign body is indicated when symptomatic in soft tissue or when located in joints [15]. The mechanism of joint destruction are the motion of irregular joint surfaces that may be formed after the initial injury, joint sepsis, lead arthropathy, foreign body reaction, synovitis, the presence of intra-articular small pieces of bone and cartilage, and metallic fragments into the joint. Shell fragments can do the same things as bullets. Exposure of a bullet to synovial fluid may lead to dissolution of the leaded fragments due to the presence of hyaluronic acid and the low pH of synovial fluid. Thus, patients with intraarticular fragments require removal because they may lead to mechanical abrasion and joint destruction [12, 15, 16–19].
Naziri et al. compared the patients who underwent primary total hip arthroplasty for degenerative joint disease and secondary arthritis due to prior gunshot wound injuries and found similar results in two groups [9]. In an another study 4 patients who developed posttraumatic arthritis from gunshot injuries to their hips underwent successful total hip arthroplasy without complications [10]. Unlike previous studies in the curent study infection rates were high and about 23% of the cases. Although in our study there is no control group. When compared with literature infection rates were high according to primary total hip arthroplasty. It was stated that infection rates after primary total hip replacement surgery vary from 0.4–1.4%, with most infections occurring during the first year [20–23].
There are limitations of the present study. First, the study design was retrospective without a control group, second the number of patients was small, there were more patients about 51 cases but these patients had incomplete medical records or were lost during follow-up. If all of the patients were enrolled the study, the result could be different.
In this small series of patients, the authors have shown that failed attempts to treat these patients operatively or nonoperatively can be addressed with total hip arthroplasty to reduce pain and improve function and range of motion at mid-term follow-up. It is effective treatment choice to reduce pain and improve function but the surgeon must be very carefull because of high rate of infection. Further studies with longer follow-up are needed.