Midterm results of two-stage revision surgery for periprosthetic shoulder infection
These authors sought to determine the recurrent infection rate and clinical outcomes of two-stage revision for shoulder periprosthetic infection (PSI).
A minimum of 5 white blood cells per high-powered field (40 times magnification) was considered diagnostic for infection.
They identified 17 patients ( Mean patient age was 64±7 years, and 65% of patients were male) that met this criterion for infection after shoulder arthroplasty who were treated with a two-stage revision and had a minimum followup of 5 years (range, 5-9 years).
As shown below, among the 17 cases, Cutibacterium was recovered from tissue samples in 6, 5 cases had negative cultures, 2 had positive cultures for MSSA, 1 for MRSA, and 1 each for enterococcus, pseudomonas, and peptostreptococcus.
The mean time from the involved arthroplasty to first stage revision was 40 months.
All patients were revised to a reverse shoulder arthroplasty at the second-stage revision.
All patients were treated with culture-specific antibiotics chosen in consultation with an infectious disease specialist, and treatment was individualized according to the virulence of the organism and general health and immunity of the patient.
The decision to re-revise for reinfection was based on various factors, including chronic, recurrent pain, wound drainage, elevated ESR and CRP, loosening of humeral or glenoid components, elevated synovial cell counts on aspiration, and positive cultures at second-stage revision or subsequent aspiration. A recurrent infection was diagnosed in 3 (18%) of the 17 patients. The cumulative incidence of recurrence of infection was 0% at 1 year, 6% at 2 years, and 18% at 5 years. There were 6 (36%) other complications, including 4 periprosthetic fractures, 1 spacer fracture, and 1 dislocation.
At latest followup, patients who did not have recurrent infection had a statistically and clinically meaningful improvement from preoperative to postoperative PROs, including VAS for pain, ASES score, SST score, and WOOS score, and active ROM, including abduction and forward flexion.
Comment: This paper demonstrates the challenges in diagnosing and managing shoulder periprosthetic infections. Here are of few:
(1) It is recognized that Cutibacterium is the most common causative organism for shoulder PJI, yet the presentation of PJI from this organism is often subtle and delayed with non-specific symptoms of pain and stiffness. Many of these cases may escape diagnosis either because a revision is not performed or because adequate sampling and culturing of deep tissue and explant specimens is not performed at revision. The stealth presentation of Cutibacterium PJI also creates a problem when evaluating the outcome of treatment for PJI. While a failure can be diagnosed if multiple cultures from a re-revision are positive, it is difficult to define a successful revision (note that in this paper the incidence of diagnosed infection increased by 300% between the second and the fifth year after the first revision - when is the patient "out of the woods"?).
(2) The post-revision treatment included "culture-specific antibiotics", however the outcome of cultures for Cutibacterium are not final until weeks after surgery; furthermore almost 1/3 of the cases had negative cultures. Thus the immediate postoperative antibiotic management cannot be based on culture results.
(3) It is not known how many patients planned for a two-stage revision did not proceed with the second stage. In this report three patients had a "permanent" spacer placed.
(4) While all the patients in this series were treated with two-stage revision to reverse total shoulder, the simpler and safer single stage revision to a hemiarthroplasty has been demonstrated to be effective in those cases of Cutibacterium PJI without a draining sinus (see this link and this link).
(5) What about "culture negative 'infections'"? The one case example presented in this paper showed high placement of the humeral component with rocking horse loosening of the glenoid component (see below).
Detritic synovitis can mimic a Propionibacterium periprosthetic infection This paper illustrates that the clinical findings of detritic synovitis (the macrophage reaction to polyethylene, cement or metal debris) complicating a total shoulder arthroplasty can strongly resemble those of a ‘stealth’ periprosthetic shoulder infection with a low-virulence organism such as Cutibacterium, including a clinical presentation long after the index procedure. At present, the important differentiation between these two etiologies can only be ascertained by awaiting the results of cultures obtained at the time of revision surgery. The surgical and antibiotic treatment decisions must be made before the culture results become available.
A 76-year-old right hand dominant man presented with right shoulder pain and decreased range of motion. He had a history of bilateral total shoulder arthroplasties, his left 15 years prior and his right 14 years prior to his visit with us. Following his index surgeries he initially did well with full painless range of motion and was able to return to full activities. Eleven years after his right arthroplasty he experienced the insidious onset of worsening shoulder pain and stiffness with no known injury. He also noted painful catching and locking in his shoulder joint with certain shoulder movements. His symptoms were unresponsive to non-operative treatment, including exercises, anti-inflammatory medications and a corticosteroid injection. His left shoulder had some stiffness but was otherwise asymptomatic. The CBC, sedimentation rate and C-reactive protein were all normal.
Physical examination demonstrated a well-healed surgical scar with no erythema, drainage or evidence of infection. Both active and passive ranges of motion were decreased. There was palpable crepitus on range of motion. Rotator cuff strength was intact, as was neurologic function of the affected extremity. Radiographs demonstrated a thinned glenoid component with surrounding osteolysis, appearing grossly loose. The humeral component was well positioned with surrounding osteolysis of the medial and lateral proximal humeral bone. There were no radiolucencies around the distal stem and the prosthesis did not appear grossly loose.
A total of 8 samples for culture were taken from various locations within the glenohumeral joint, including the glenoid membrane, collar membrane between the modular humeral head and stem, humeral canal membrane, bursa, glenoid explant, and stem explant. Due to preoperative and intraoperative concerns of infection, including cloudy fluid, abundant membrane, glenoid loosening and osteolysis, the patient was treated with a one-stage revision consisting of removal of the loose glenoid and single stage exchange of the humeral component using Vancomycin soaked cancellous allograft to secure the stem by impaction grafting. The remaining glenoid bone was smoothed, no bone graft was added, and no glenoid component was reimplanted. Cultures were grown on four types of media: blood agar, chocolate agar, Brucella agar and brain-heart infusion broth as previously published. Postoperatively the patient was placed on IV Ceftriaxone 2g daily and Vancomycin 1g daily via PICC line. The Vancomycin was discontinued after 2 days when the cultures failed to grow MecA CoNS. All cultures were negative at 21 days at which time all antibiotics were discontinued. Permanent pathology of the deep tissues identified fibrotic tissue with chronic inflammation, the absence of neutrophils, and a foreign body giant cell reaction consistent with detritic synovitis
After surgery, he was placed on the standard post arthroplasty rehabilitation program focusing on range of motion in the first six weeks, followed by progressive anterior deltoid strengthening. At his six-month follow up visit, the patient was recovering well with no complaints of pain. His Simple Shoulder Test had improved from 5 out of 12 prior to his revision to 10 of 12, and radiographs showed a well-fixed humeral component.
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