A 54-year-old man with a history of depression, post-traumatic stress disorder, bipolar 1 disorder and IV drug use presented to the ED with 2 weeks of slowly worsening right knee/leg pain and difficulty bearing weight.
Two months prior, at another hospital, the patient had undergone arthroscopic right knee irrigation and debridement (I&D) with a small open I&D of an abscess over the anteromedial (AM) proximal tibia. He subsequently left the hospital against medical advice and returned 1 week later with continued symptoms and had the operation repeated. Initial intraoperative cultures grew MRSA, and he was eventually discharged to a skilled nursing facility with 6 weeks of IV vancomycin. The patient now presented to the ED 2 weeks following completion of this antibiotic course. On exam, he had no obvious deformity or abscess with only erythema and tenderness to palpation around the AM proximal tibia incision. His arthroscopic incisions appeared benign. He could actively range the knee 0° to 80°, but with significant pain. He was unable to bear weight. His white blood cell (WBC) count and C-reactive protein were normal. The erythrocyte sedimentation rate was slightly elevated. A radiograph (Figure 1), CT scan and MRI (Figure 2) revealed a proximal tibia fracture through osteomyelitis.
There are multiple options to address this problem. Nonoperative management can be considered. This would require lengthy immobilization in a splint, cast or brace with strict patient compliance for non-weight-bearing and range of motion. External fixation, either traditional or with a ring fixator construct, is an option, as well. Again, this necessitates having a compliant patient who will follow surgeon guidelines. Given this patient’s medical and behavioral history, we did not feel nonoperative care or an external fixator were the best options for him. Open reduction and internal fixation remains an option in this case.
For this proximal tibia fracture pattern, both intramedullary (IM) nail and plate and screw constructs could be considered. If deciding upon IM, one must consider the pros, cons and surgeon’s familiarity with performing a suprapatellar vs. infrapatellar approach. If utilizing a plate and screw construct, thought must be given to utilizing a larger incision with traditional plating technique vs. a more minimally invasive system/approach.
Finally, the issue of the underlying infection must be addressed, particularly if choosing internal fixation and placing hardware into or onto an infected bone. Does the bone or surrounding soft tissue require extensive debridement? Does the infection require serial debridement and staging of multiple operations, or will a single-stage procedure be sufficient? What local antibiotics should be used and what dose? What is the delivery method of the local antibiotic (ie, powder, absorbable carrier, antibiotic-coated hardware, etc.)? These questions should all be considered, and oftentimes do not have an easy or correct answer.
The decision was made to proceed with repeat right knee arthrotomy with I&D, debridement of the proximal tibia and placement of an antibiotic-coated tibial nail. The patient was placed on the table in supine position with general anesthesia. An incision was made through his prior AM proximal tibial scar. No purulence was appreciated in the soft tissues. A small sample of bone was taken for culture and the wound was copiously irrigated. Although it maintained structural integrity, the bone was noted to be of less than normal quality. Next, an incision on the superior aspect of the knee was made, followed by soft tissue dissection and finally splitting of the quadriceps tendon in line with its fibers. Synovial tissue was sent for permanent culture and the joint was copiously irrigated. We proceeded to fixation of the tibia. Using the arthrotomy, a guidewire was placed in the appropriate starting position for a tibial nail. This was verified on anteroposterior (AP) and lateral fluoroscopy. The guidewire in the tibia was sequentially reamed up to 13 mm. This was considered the debridement of the patient’s bone. After we had reamed, we used a pituitary rongeur to collect a specimen of bone in the area of osteomyelitis, which was passed off the field to be used as a culture. We used cysto-tubing to irrigate the medullary canal with copious saline.
At this point, we began placing the cement coating on the tibial nail (Figure 3). We had selected an appropriate length nail based upon measurement and elected to use an 8-mm nail diameter. Two units of cement were mixed per manufacturer’s protocol with the addition of vancomycin and tobramycin. The cement was then placed into 12-mm gynecological dilation and curettage tubing, followed by the tibial nail being placed into the cement-filled tube. No lubricants were placed onto the nail or tubing. A guidewire was passed through the nail several times to prevent cement polymerization and build-up within the nail. The cement was allowed to fully polymerize around the nail. The tubing was then cut away abruptly as the cement temperature began to increase. There was excellent coating circumferentially around the nail. Prior to insertion, a drill bit and rongeur were used to remove the cement over both the proximal and distal interlocking screw holes. The nail was then passed down the IM canal without difficulty. Two appropriately sized proximal interlocking screws were passed through the jig and two distal screws were placed using the perfect circles technique. Fluoroscopic images were obtained to ensure appropriate reduction of the fracture and placement of implants. The wounds were closed in layers, a drain was placed into the knee joint and sterile dressings were applied.
Immediate postoperative X-rays were obtained (Figure 4). MRSA was grown only on cultures from the tibia sent to the lab. The patient was discharged with 6 weeks of IV vancomycin per infectious disease consultation recommendations. He was kept non-weight-bearing for the first 2 weeks postoperatively per surgeon preference and then transitioned to weight-bearing as tolerated. The patient did return to his follow-up appointments. At 6 months postoperatively, he was doing well with full weight-bearing without pain, normal knee range of motion, no signs of recurrent infection and with radiographic evidence of healing without obvious early complication (Figure 5). He had follow-up with the infectious disease service and completed his course of antibiotics. His ESR, CRP and WBC counts were normal.
Proximal tibia fractures can be difficult to manage. There are well-documented complications including anterior knee pain, nonunion and malunion with a valgus and procurvatum deformity. Fracture, combined with underlying infection, in the proximal tibia presents a unique challenge for the treating surgeon. There is an overall paucity of literature regarding treatment of tibial fractures secondary to osteomyelitis. A general consensus exists that fixation of tibial fractures in the adult results in superior outcomes when compared to nonoperative management. Loss of alignment, knee and ankle stiffness, muscle wasting, poor mobility, deep vein thrombosis and slower return to work have all been reported. With appropriate patient selection, external fixation can be a reasonable treatment option for this problem. One-year outcome data suggest no difference in knee or ankle mobility or range of motion but do report pin site infection rates as high as 60% and a malunion rate between 2% and 18%.
Plate and screw fixation also could be considered. Outcomes are generally comparable to IM nailing, but with a higher rate of postoperative infection and painful hardware. Plate fixation could have been considered in this case as a small AM incision was already present from prior surgery, but ultimately it was felt that the use of an antibiotic-coated IM nail was the best option to allow for both fracture fixation and treatment of the patient’s osteomyelitis. Both suprapatellar and infrapatellar approaches can be utilized. Suprapatellar nailing has demonstrated better alignment for both proximal and distal tibial shaft fractures with comparable amounts of postoperative anterior knee pain. Proceeding with IM nailing, particularly the suprapatellar approach, in the setting of previous septic knee arthritis is certainly a valid concern. While the patient had prior knee I&Ds, these were performed arthroscopically, so there was no previous anterior midline incision which could potentially be utilized. Given these unique circumstances, it was felt the best treatment option would be a superior knee arthrotomy through which both I&D and IM nailing could be achieved. While the techniques vary widely based upon surgeon preference, the data supporting antibiotic-coated nails suggest both infection eradication and fracture healing can be successfully achieved without necessitating implant removal or staging of the operation. Given the patient’s history, as well as decreased quality of the bone in the proximal tibia, limiting weight-bearing was felt to be the best option in this scenario.
Fractures through infection and osteomyelitis are unique challenges. A full spectrum of treatment options exists depending on specific patient characteristics and circumstances. Successful treatment can be achieved in multiple ways, but these cases require thoughtful consideration to determine the most appropriate plan for the patient.
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